Sample records for lead-free solder misbehaves

  1. How Lead-Free Solder (Mis)Behaves under Stress | Advanced Photon...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the evolution of crystal orientation and strain patterns during thermal cycling in tin-containing, lead-free solder joints, specifically in the commonly used...

  2. Lead-free solder

    DOE Patents [OSTI]

    Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2001-05-15T23:59:59.000Z

    A Sn--Ag--Cu eutectic alloy is modified with one or more low level and low cost alloy additions to enhance high temperature microstructural stability and thermal-mechanical fatigue strength without decreasing solderability. Purposeful fourth or fifth element additions in the collective amount not exceeding about 1 weight % (wt. %) are added to Sn--Ag--Cu eutectic solder alloy based on the ternary eutectic Sn--4.7%Ag--1.7%Cu (wt. %) and are selected from the group consisting essentially of Ni, Fe, and like-acting elements as modifiers of the intermetallic interface between the solder and substrate to improve high temperature solder joint microstructural stability and solder joint thermal-mechanical fatigue strength.

  3. Breakthrough: Lead-free Solder

    SciTech Connect (OSTI)

    Anderson, Iver

    2012-01-01T23:59:59.000Z

    Ames Laboratory senior metallurgist Iver Anderson explains the importance of lead-free solder in taking hazardous lead out of the environment by eliminating it from discarded computers and electronics that wind up in landfills. Anderson led a team that developed a tin-silver-copper replacement for traditional lead-tin solder that has been adopted by more than 50 companies worldwide.

  4. Breakthrough: Lead-free Solder

    ScienceCinema (OSTI)

    Anderson, Iver

    2013-03-01T23:59:59.000Z

    Ames Laboratory senior metallurgist Iver Anderson explains the importance of lead-free solder in taking hazardous lead out of the environment by eliminating it from discarded computers and electronics that wind up in landfills. Anderson led a team that developed a tin-silver-copper replacement for traditional lead-tin solder that has been adopted by more than 50 companies worldwide.

  5. Lead-Free Solder - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lab Date Patent 5,527,628 Patent 5,527,628 Pb-free Sn-Ag-Cu ternary eutectic solder A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6...

  6. Microstructure and In Situ Observations of Undercooling for Nucleation of ?-Sn Relevant to Lead-Free Solder Alloys

    E-Print Network [OSTI]

    Elmer, John W.; Specht, Eliot D.; Kumar, Mukul

    2010-01-01T23:59:59.000Z

    K.J. Puttlitz, Handbook of Lead-Free Solder Technology forNucleation of b-Sn Relevant to Lead-Free Solder Alloys JOHNcation of tin and tin-based lead-free solder alloys can

  7. Lab Breakthrough: Lead-free Solder | Department of Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-free Solder Lab

  8. Assessment of circuit board surface finishes for electronic assembly with lead-free solders

    SciTech Connect (OSTI)

    Ray, U.; Artaki, I.; Finley, D.W.; Wenger, G.M. [Bell Labs., Princeton, NJ (United States). Lucent Technologies; Pan, T.; Blair, H.D.; Nicholson, J.M. [Ford Motor Co., Dearborn, MI (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1996-10-01T23:59:59.000Z

    The suitability of various metallic printed wiring board surface finishes was assessed for new technology applications that incorporate assembly with Lead-free solders. The manufacture of a lead-free product necessitates elimination of lead (Pb) from the solder, the circuit board as well as the component lead termination. It is critical however for the selected interconnect Pb-free solder and the corresponding printed wiring board (PWB) and component lead finishes to be mutually compatible. Baseline compatibility of select Pb-free solders with Pb containing PWB surface finish and components was assessed. This was followed by examining the compatibility of the commercially available CASTIN{trademark} (SnAgCuSb) Pb-free solder with a series of PWB metallic finishes: Ni/Au, Ni/Pd, and Pd/Cu. The compatibility was assessed with respect to assembly performance, solder joint integrity and long term attachment reliability. Solder joint integrity and mechanical behavior of representative 50 mil pitch 20I/O SOICs was determined before and after thermal stress. Mechanical pull test studies demonstrated that the strength of SnAgCuSb solder interconnections is notably greater than that of SnPb interconnections.

  9. Concurrent electromigration and creep in lead-free solder Matt Pharr,1

    E-Print Network [OSTI]

    Suo, Zhigang

    Concurrent electromigration and creep in lead-free solder Matt Pharr,1 Kejie Zhao,1 Zhigang Suo,1,a) Fan-Yi Ouyang,2,3 and Pilin Liu2 1 School of Engineering and Applied Sciences and Kavli Institute Development Center, Chandler, Arizona 85226, USA 3 Department of Engineering and System Science, National

  10. Compatibility of lead-free solders with lead containing surface finishes as a reliability issue in electronic assemblies

    SciTech Connect (OSTI)

    Vianco, P.; Rejent, J. [Sandia National Labs., Albuquerque, NM (United States); Artaki, I.; Ray, U.; Finley, D.; Jackson, A. [AT and T Bell Labs., Princeton, NJ (United States)

    1996-03-01T23:59:59.000Z

    Enhanced performance goals and environmental restrictions have heightened the consideration for use of alternative solders as replacements for the traditional tin-lead (Sn-Pb) eutectic and near-eutectic alloys. However, the implementation of non-Pb bearing surface finishes may lag behind solder alloy development. A study was performed which examined the effect(s) of Pb contamination on the performance of Sn-Ag-Bi and Sn-Ag-Cu-Sb lead-free solders by the controlled addition of 63Sn-37Pb solder at levels of 0.5 {minus} 8.0 wt.%. Thermal analysis and ring-in-plug shear strength studies were conducted on bulk solder properties. Circuit board prototype studies centered on the performance of 20I/O SOIC gull wing joints. Both alloys exhibited declines in their melting temperatures with greater Sn-Pb additions. The ring-in-plug shear strength of the Sn-Ag-Cu-Sb solder increased slightly with Sn-Pb levels while the Sn-Ag-Bi alloy experienced a strength loss. The mechanical behavior of the SOIC (Small Outline Integrated Circuit) Sn-Ag-Bi solder joints reproduced the strength levels were insensitive to 10,106 thermal cycles. The Sn-Ag-Cu-Sb solder showed a slight decrease in the gull wing joint strengths that was sensitive to the Pb content of the surface finish.

  11. Intermetallic Growth Studies on Sn-Ag-Cu Lead-Free Solder Joints

    E-Print Network [OSTI]

    Zhou, Wei

    -free solder reflow manufacturing of electronics assemblies.1 In the European Union, the WEEE and Ro

  12. 1-4244-0665-X/06/$20.00 2006 IEEE 781 2006 Electronics Packaging Technology Conference Development of Life Prediction Model for Lead-free Solder at Chip Resistor

    E-Print Network [OSTI]

    Berlin,Technische Universität

    of Life Prediction Model for Lead-free Solder at Chip Resistor Changwoon Han and Byeongsuk Song-mail : cw_han@keti.re.kr Abstract An accelerated thermal cycling test to assess the reliability of lead-free solders at chip resistor has been conducted. Test results indicate that the life of lead-free solder

  13. Tuning and parameter optimization of a digital integral controller for uniform droplet spray applications using lead-free tin-copper solder

    E-Print Network [OSTI]

    De Castro, Eloisa M

    2009-01-01T23:59:59.000Z

    The advent of legislation restricting the use of lead in electronics requires innovation and refinement in processes for creating lead-free solder spheres for wafer bumping and other surface mount technology. Operation ...

  14. Suppressing tin whisker growth in lead-free solders and platings

    DOE Patents [OSTI]

    Hoffman, Elizabeth N; Lam, Poh-Sang

    2014-04-29T23:59:59.000Z

    A process of irradiation Sn containing Pb-free solder to mitigate whisker formation and growth thereon is provided. The use of gamma radiation such as cobalt-60 has been applied to a substrate of Sn on copper has been found to change the morphology of the crystalline whisker growth to a more truncated hillock pattern. The change in morphology greatly reduces the tendency of whiskers to contribute to electrical short-circuits being used as a Pb-free solder system on a copper substrate.

  15. Microstructure and Sn crystal orientation evolution in Sn-3.5Ag lead-free solders in high temperature packaging applications

    SciTech Connect (OSTI)

    Zhou, Bite [ORNL; Muralidharan, Govindarajan [ORNL; Kurumaddali, Nalini Kanth [ORNL; Parish, Chad M [ORNL; Leslie, Dr Scott [Powerex Inc; Bieler, T. R. [Michigan State University, East Lansing

    2014-01-01T23:59:59.000Z

    Understanding the reliability of eutectic Sn-3.5Ag lead-free solders in high temperature packaging applications is of significant interest in power electronics for the next generation electric grid. Large area (2.5mm 2.5mm) Sn-3.5Ag solder joints between silicon dies and direct bonded copper substrates were thermally cycled between 5 C and 200 C. Sn crystal orientation and microstructure evolution during thermal cycling were characterized by electron backscatter diffraction (EBSD) in scanning electron microscope (SEM). Comparisons are made between observed initial texture and microstructure and its evolution during thermal cycling. Gradual lattice rotation and grain boundary misorientation evolution suggested the continuous recrystallization mechanism. Recrystallization behavior was correlated with dislocation slip activities.

  16. Journal of ELECTRONIC MATERIALS, Vol. 33, No. 12, 2004 Special Issue Paper Intermetallic Phase Detection in Lead-Free Solders Using

    E-Print Network [OSTI]

    Ekere, Ndy

    -of-the-art electronic components, thereby allowing new, lead-free materials to be fully characterized. Key words: X 2006.1 For many manufacturers, the reliability of elec- tronic components is a major concern becauseJournal of ELECTRONIC MATERIALS, Vol. 33, No. 12, 2004 Special Issue Paper 1524 Intermetallic Phase

  17. Wave soldering with Pb-free solders

    SciTech Connect (OSTI)

    Artaki, I.; Finley, D.W.; Jackson, A.M.; Ray, U. [AT and T Bell Labs., Princeton, NJ (United States); Vianco, P.T. [Sandia National Labs., Albuquerque, NM (United States)

    1995-07-01T23:59:59.000Z

    The manufacturing feasibility and attachment reliability of a series of newly developed lead-free solders were investigated for wave soldering applications. Some of the key assembly aspects addressed included: wettability as a function of board surface finish, flux activation and surface tension of the molten solder, solder joint fillet quality and optimization of soldering thermal profiles. Generally, all new solder formulations exhibited adequate wave soldering performance and can be considered as possible alternatives to eutectic SnPb for wave soldering applications. Further process optimization and flux development is necessary to achieve the defect levels associated with the conventional SnPb process.

  18. Lead Free Solder - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TVs, and VCRs. Direct Link to Article:http:www.ameslab.govfilesTTsuccessstory-leadfreesolder.pdf Ames Laboratory Iowa State University Research Foundation - Office of...

  19. Lead-free primary explosives

    DOE Patents [OSTI]

    Huynh, My Hang V.

    2010-06-22T23:59:59.000Z

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  20. Lead-Free Solder Paste | The Ames Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -of Energy LastLawrenceLawsE C H N I

  1. Age-aware solder performance models : level 2 milestone completion.

    SciTech Connect (OSTI)

    Neilsen, Michael K.; Vianco, Paul Thomas; Neidigk, Matthew Aaron; Holm, Elizabeth Ann

    2010-09-01T23:59:59.000Z

    Legislated requirements and industry standards are replacing eutectic lead-tin (Pb-Sn) solders with lead-free (Pb-free) solders in future component designs and in replacements and retrofits. Since Pb-free solders have not yet seen service for long periods, their long-term behavior is poorly characterized. Because understanding the reliability of Pb-free solders is critical to supporting the next generation of circuit board designs, it is imperative that we develop, validate and exercise a solder lifetime model that can capture the thermomechanical response of Pb-free solder joints in stockpile components. To this end, an ASC Level 2 milestone was identified for fiscal year 2010: Milestone 3605: Utilize experimentally validated constitutive model for lead-free solder to simulate aging and reliability of solder joints in stockpile components. This report documents the completion of this milestone, including evidence that the milestone completion criteria were met and a summary of the milestone Program Review.

  2. Sector 6 Research Highlights

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    under Stress How Lead-Free Solder (Mis)Behaves under Stress October 10, 2012 The reliability and longevity of electronics is critical to current telecommunications...

  3. Intelligent Management of Misbehaving Nodes In Wireless Sensor Networks

    E-Print Network [OSTI]

    Gesbert, David

    Intelligent Management of Misbehaving Nodes In Wireless Sensor Networks Using Blackhole@eurecom.fr Abstract--Misbehaving nodes in wireless sensor networks and ad hoc networks often disrupt the operation delivery and erroneous data outputs for wireless sensor networks. Existing literatures have addressed

  4. 478 IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES, VOL. 31, NO. 2, JUNE 2008 Reliability and Failure Analysis of Lead-Free

    E-Print Network [OSTI]

    Kim, Yong Jung

    in Korea through "Development of Reliability Design Technique and Life Prediction Model for Electronic478 IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES, VOL. 31, NO. 2, JUNE 2008 Reliability and Failure Analysis of Lead-Free Solder Joints for PBGA Package Under a Cyclic Bending Load Ilho

  5. Lead-Free Surface Finishes for Electronic Components

    E-Print Network [OSTI]

    Lead-Free Surface Finishes for Electronic Components: Tin Whisker Growth METALS This project degraded by the switch to lead- free technology. In particular, the state of compressive stress and the localized creep response (whisker growth) of tin-based lead-free electrodeposits are being measured

  6. Suppression of Tin Whiskers in Lead-Free Solder - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our InstagramStructure ofIndustrialSupporting Data-ProducingSupportingSuppression of

  7. Solderability test system

    DOE Patents [OSTI]

    Yost, F.; Hosking, F.M.; Jellison, J.L.; Short, B.; Giversen, T.; Reed, J.R.

    1998-10-27T23:59:59.000Z

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time. 11 figs.

  8. Solderability test system

    DOE Patents [OSTI]

    Yost, Fred (Cedar Crest, NM); Hosking, Floyd M. (Albuquerque, NM); Jellison, James L. (Albuquerque, NM); Short, Bruce (Beverly, MA); Giversen, Terri (Beverly, MA); Reed, Jimmy R. (Austin, TX)

    1998-01-01T23:59:59.000Z

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time.

  9. Study of the Interface Microstructure of Sn-Ag-Cu Lead-Free Solders and the Effect of Solder Volume on Intermetallic Layer Formation.

    E-Print Network [OSTI]

    Ekere, Ndy

    , European legislation under the Waste from Electrical and Electronic Equipment (WEE) is scheduled on Intermetallic Layer Formation. B. Salam+ , N. N. Ekere, D. Rajkumar Electronics Manufacturing Engineering products, the main concern continues to be lead contamination from end-of-life electronic products

  10. Feature selection for automatic solder joint inspection

    E-Print Network [OSTI]

    Lee, Cheng-Cheng

    1987-01-01T23:59:59.000Z

    - heating Wave Soldering Drag Soldering Post- soldering Cleaning Inspection and Testing Vapor So Ide ring Fig. 2. 3 Typical Soldering Process 12 (5) simplicity of repair, (6) visual inspectability. The first three properties depend upon both.../testing after the soldering. Good joints after inspection can be sent to the testing process directly, while bad joints should be returned to be touched up by the operator. The types of test depend upon the product. For a typical PC board, electrical test...

  11. Tin-silver-bismuth solders for electronics assembly

    DOE Patents [OSTI]

    Vianco, P.T.; Rejent, J.A.

    1995-08-08T23:59:59.000Z

    A lead-free solder alloy is disclosed for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

  12. Tin-silver-bismuth solders for electronics assembly

    DOE Patents [OSTI]

    Vianco, Paul T. (Albuquerque, NM); Rejent, Jerome A. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

  13. Solder self-assembly for MEMS fabrication

    E-Print Network [OSTI]

    Au, Hin Meng, 1977-

    2004-01-01T23:59:59.000Z

    This thesis examines and demonstrates self-assembly of MEMS components on the 25 micron scale onto substrates using the capillary force of solder. This is an order of magnitude smaller than current solder self-assembly in ...

  14. Lead-free precussion primer mixes based on metastable interstitial composite (MIC) technology

    DOE Patents [OSTI]

    Dixon, George P. (Alexandria, VA); Martin, Joe A. (Espanola, NM); Thompson, Don (Ridgecrest, CA)

    1998-01-01T23:59:59.000Z

    A lead-free percussion primer composition and a percussion cup containing e composition. The lead-free percussion primer composition is comprised of a mixture of about 45 wt % aluminum powder having an outer coating of aluminum oxide and molybdenum trioxide powder or a mixture of about 50 wt % aluminum powder having an outer coating of aluminum oxide and polytetrafluoroethylene powder. The aluminum powder, molybdenum trioxide powder and polytetrafluoroethylene powder has a particle size of 0.1 .mu.m or less, more preferably a particle size of from about 200-500 angstroms.

  15. Proceedings of the 2007 Aging Aircraft Conference Cost Model for Assessing the Transition to Lead-Free Electronics

    E-Print Network [OSTI]

    Sandborn, Peter

    Proceedings of the 2007 Aging Aircraft Conference Cost Model for Assessing the Transition to Lead the cost ramifications of the transition from tin- lead to lead-free electronic parts. All tin-lead, all lead-free and mixed assembly approaches are considered. The model makes basic assumptions of a fixed

  16. Microstructural evolution of eutectic Au-Sn solder joints

    E-Print Network [OSTI]

    Song, Ho Geon

    2002-01-01T23:59:59.000Z

    resistance of electroless nickel- phosphorus coatings”,between solder and electroless nickel deposits”, Mater.packages soldered on electroless nickel/immersion gold”,

  17. Nano-soldering to single atomic layer

    DOE Patents [OSTI]

    Girit, Caglar O. (Berkeley, CA); Zettl, Alexander K. (Kensington, CA)

    2011-10-11T23:59:59.000Z

    A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.

  18. Organic solderability preservation evaluation. Topical report

    SciTech Connect (OSTI)

    Becka, G.A.; McHenry, M.R.; Slanina, J.T.

    1997-03-01T23:59:59.000Z

    An evaluation was conducted to determine the possible replacement of the hot air solder leveling (HASL) process used in the Allied Signal Federal Manufacturing & Technologies (FM&T) Printed Wiring Board Facility with an organic solderability preservative (OSP). The drivers for replacing HASL include (1) Eliminating lead from PWB fabrication processes; (2) Potential legislation restricting use of lead, (3) Less expensive processing utilizing OSP rather than HASL processing; (4) Avoiding solder dross disposal inherent with HASL processing, (5) OSP provides flat, planar surface required for surface mount technology product, and (6) Trend to thinner PWB designs. A reduction in the cost of nonconformance (CONC) due to HASL defects (exposed copper, solderability, dewetting and non-wetting) would be realized with the incorporation of the OSP process. Several supplier HASL replacement candidates were initially evaluated. One supplier chemistry was chosen for potential use in the FM&T PWB and assembly areas.

  19. alternative solder alloys: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    devices have involved developing structural integrity models for predicting the operating lifetime under vibratory and thermal environmental exposure. Solder joint...

  20. SU-E-P-09: Radiation Transmission Measurements and Evaluation of Diagnostic Lead-Based and Lead-Free Aprons

    SciTech Connect (OSTI)

    Syh, J [Willis-Knighton Medical Center, Shreveport, LA (United States)

    2014-06-01T23:59:59.000Z

    Purpose: This study was conducted to ensure that various lead shield apron manufacturers provided accurate attenuation factors regardless of whether the apron was made of lead-based or lead-free equivalent material. Methods: A calibrated ionization survey meter was placed at chest height and 36 cm horizontally away from a solid water phantom on a simulator couch. Measurements were done with or without apron. Radiation field was set to 24cmx24cm with the phantom at 100cm source-to-surface distance. Irradiation time was set for 1 minute at voltages of 60, 80, 100 and 120 kVp. Current was set at 6mA. Results: Between 60 kVp and 120 kVp, the transmission through 0.50 mm of lead-based apron was between 1.0% and 6.5% with a mean value of 3.2% and a standard deviation (s.d.) of 1.4%. The transmissions through the 0.50 mm lead-free aprons were 1.0 % to 12.0% with a mean value of 6.1% and s.d. of 2.6%. At 120 kVp, the transmission value was 6.5% for 0.50 mm lead-based apron and 11.1% to 12.0% for 0.50 mm lead-free aprons. The radiation transmissions at 80 kVp, measured in two different 0.5 mm lead-free aprons, were 4.3% each. However, only 1.4% transmission was found through the lead-based apron. Overall, the radiation transmitted through the lead-based apron was 1/3 transmission of lead-free at 80kVp, and half value of lead-free aprons at 100 and 120 kVp. Conclusion: Even though lead-based and lead-free aprons all claimed to have the same lead equivalent thickness, the transmission might not be the same. The precaution was needed to exercise diligence in quality assurance program to assure adequate protection to staff who wear it during diagnostic procedures. The requirement for aprons not only should be in certain thickness to meet state regulation but also to keep reasonably achievable low exposure with the accurate labeling from manufacturers.

  1. MODEL D650 INDUSTRIAL SOLDERING GUN PRODUCT DESCRIPTION

    E-Print Network [OSTI]

    Kleinfeld, David

    applications, a selection of soldering, cutting, and smoothing tips are available for the D650. OPERATING and with heat flows into the joint via capillary action, fusing the parts together. A properly soldered joint is considered both mechanically stable and electrically efficient. To correctly solder a joint, you need

  2. Microstructural evolution of eutectic Au-Sn solder joints

    SciTech Connect (OSTI)

    Song, Ho Geon

    2002-05-31T23:59:59.000Z

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  3. Solderability Study of RABiTS-Based YBCO Coated Conductors

    SciTech Connect (OSTI)

    Zhang, Yifei [ORNL; Duckworth, Robert C [ORNL; Ha, Tam T [ORNL; Gouge, Michael J [ORNL

    2011-01-01T23:59:59.000Z

    The solderability of commercially available YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) coated conductors that were made from Rolling Assisted Biaxially Textured Substrates (RABiTS)-based templates was studied. The coated conductors, also known as second-generation (2G) high temperature superconductor (HTS) wires (in the geometry of flat tapes about 4 mm wide), were laminated with copper, brass, or stainless steel strips as stabilizers. To understand the factors that influence their solderability, surface profilometry and scanning electron microscopy were used to characterize the wire surfaces. The solderability of three solders, 52In48Sn, 67Bi33In, and 100In (wt.%), was evaluated using a standard test (IPC/ECA J-STD-002) and with two different commercial fluxes. It was found that the solderability varied with the solder and flux but the three different wires showed similar solderability for a fixed combination of solder and flux. Solder joints of the 2G wires were fabricated using the tools and the procedures recommended by the HTS wire manufacturer. The solder joints were made in a lap-joint geometry and with the superconducting sides of the two wires face-to-face. The electrical resistances of the solder joints were measured at 77 K, and the results were analyzed to qualify the soldering materials and evaluate the soldering process. It was concluded that although the selection of soldering materials affected the resistance of a solder joint, the resistivity of the stabilizer was the dominant factor.

  4. Solder flow over fine line PWB surface finishes

    SciTech Connect (OSTI)

    Hosking, F.M.; Hernandez, C.L.

    1998-08-01T23:59:59.000Z

    The rapid advancement of interconnect technology has stimulated the development of alternative printed wiring board (PWB) surface finishes to enhance the solderability of standard copper and solder-coated surfaces. These new finishes are based on either metallic or organic chemistries. As part of an ongoing solderability study, Sandia National Laboratories has investigated the solder flow behavior of two azole-based organic solderability preservations, immersion Au, immersion Ag, electroless Pd, and electroless Pd/Ni on fine line copper features. The coated substrates were solder tested in the as-fabricated and environmentally-stressed conditions. Samples were processed through an inerted reflow machine. The azole-based coatings generally provided the most effective protection after aging. Thin Pd over Cu yielded the best wetting results of the metallic coatings, with complete dissolution of the Pd overcoat and wetting of the underlying Cu by the flowing solder. Limited wetting was measured on the thicker Pd and Pd over Ni finishes, which were not completely dissolved by the molten solder. The immersion Au and Ag finishes yielded the lowest wetted lengths, respectively. These general differences in solderability were directly attributed to the type of surface finish which the solder came in contact with. The effects of circuit geometry, surface finish, stressing, and solder processing conditions are discussed.

  5. Solder for oxide layer-building metals and alloys

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1992-01-01T23:59:59.000Z

    A low temperature solder and method for soldering an oxide layer-building metal such as aluminum, titanium, tantalum or stainless steel. The comosition comprises tin and zinc; germanium as a wetting agent; preferably small amounts of copper and antimony; and a grit, such as silicon carbide. The grit abrades any oxide layer formed on the surface of the metal as the germanium penetrates beneath and loosens the oxide layer to provide good metal-to-metal contact. The germanium comprises less than aproximatley 10% by weight of the solder composition so that it provides sufficient wetting action but does not result in a melting temperature above approximately 300.degree. C. The method comprises the steps rubbing the solder against the metal surface so the grit in the solder abrades the surface while heating the surface until the solder begins to melt and the germanium penetrates the oxide layer, then brushing aside any oxide layer loosened by the solder.

  6. Solder for oxide layer-building metals and alloys

    DOE Patents [OSTI]

    Kronberg, J.W.

    1992-09-15T23:59:59.000Z

    A low temperature solder and method for soldering an oxide layer-building metal such as aluminum, titanium, tantalum or stainless steel is disclosed. The composition comprises tin and zinc; germanium as a wetting agent; preferably small amounts of copper and antimony; and a grit, such as silicon carbide. The grit abrades any oxide layer formed on the surface of the metal as the germanium penetrates beneath and loosens the oxide layer to provide good metal-to-metal contact. The germanium comprises less than approximately 10% by weight of the solder composition so that it provides sufficient wetting action but does not result in a melting temperature above approximately 300 C. The method comprises the steps rubbing the solder against the metal surface so the grit in the solder abrades the surface while heating the surface until the solder begins to melt and the germanium penetrates the oxide layer, then brushing aside any oxide layer loosened by the solder.

  7. University of California, Irvine Environmental Health and Safety www.ehs.uci.edu Questions Call: (949) 824-6200 Version 1.0 Lead Free UCI

    E-Print Network [OSTI]

    George, Steven C.

    : (949) 824-6200 Version 1.0 Lead Free UCI Autoclave Tape - Get the Lead Out Environmental Health risks of lead pollution, and Replace lead containing autoclave tape with lead-free autoclave tape for FREE. Autoclave tape used in some laboratories may contain levels of lead that exceed the hazardous

  8. Capillary flow solderability test for printed wiring boards

    SciTech Connect (OSTI)

    Hosking, F.M.; Yost, F.G.; Hernandez, C.L.; Sackinger, S.J.

    1994-04-01T23:59:59.000Z

    This report describes a new technique for evaluating capillary flow solderability on printed circuit boards. The test involves the flow of molten solder from a pad onto different-sized conductor lines. It simulates the spreading dynamics of either plated-through-hole (PTH) or surface mount technology (SMT) soldering. A standard procedure has been developed for the test. Preliminary experiments were conducted and the results demonstrate test feasibility. Test procedures and results are presented in this report.

  9. Piezoelectric and ferroelectric properties of lead-free niobium-rich potassium lithium tantalate niobate single crystals

    SciTech Connect (OSTI)

    Li, Jun, E-mail: lijuna@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Li, Yang [Department of chemistry, Harbin Institute of Technology, Harbin 150001 (China); Zhou, Zhongxiang [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Guo, Ruyan; Bhalla, Amar S. [Multifunctional Electronic Materials and Device Research Lab, Department of Electrical and Computer Engineering, The University of Texas at San Antonio, San Antonio 78249 (United States)

    2014-01-01T23:59:59.000Z

    Graphical abstract: - Highlights: • Lead-free K{sub 0.95}Li{sub 0.05}Ta{sub 1?x}Nb{sub x}O{sub 3} single crystals were grown using the top-seeded melt growth method. • The piezoelectric and ferroelectric properties of as-grown crystals were systematically investigated. • The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ? 70%, k{sub 31} ? 70%, k{sub 33} ? 77%, d{sub 31} ? 230 pC/N, d{sub 33} ? 600 pC/N. • The coercive fields of P–E hysteresis loops are quite small, about or less than 1 kV/mm. - Abstract: Lead-free potassium lithium tantalate niobate single crystals with the composition of K{sub 0.95}Li{sub 0.05}Ta{sub 1?x}Nb{sub x}O{sub 3} (abbreviated as KLTN, x = 0.51, 0.60, 0.69, 0.78) were grown using the top-seeded melt growth method. Their piezoelectric and ferroelectric properties in as-grown crystals have been systematically investigated. The phase transitions and Curie temperatures were determined from dielectric and pyroelectric measurements. Piezoelectric coefficients and electromechanical coupling factors in thickness mode, length-extensional mode and longitudinal mode were obtained. The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ? 70%, k{sub 31} ? 70%, k{sub 33} ? 77%, d{sub 31} ? 230 pC/N, d{sub 33} ? 600 pC/N are comparable to the lead-based PZT composition. The polarization versus electric field hysteresis loops show saturated shapes. In short, lead-free niobium-rich KLTN system possesses comparable properties to those in important lead-based piezoelectric material nowadays.

  10. Dry soldering with hot filament produced atomic hydrogen

    DOE Patents [OSTI]

    Panitz, Janda K. G. (Edgewood, NM); Jellison, James L. (Albuquerque, NM); Staley, David J. (Los Lunas, NM)

    1995-01-01T23:59:59.000Z

    A system for chemically transforming metal surface oxides to metal that is especially, but not exclusively, suitable for preparing metal surfaces for dry soldering and solder reflow processes. The system employs one or more hot, refractory metal filaments, grids or surfaces to thermally dissociate molecular species in a low pressure of working gas such as a hydrogen-containing gas to produce reactive species in a reactive plasma that can chemically reduce metal oxides and form volatile compounds that are removed in the working gas flow. Dry soldering and solder reflow processes are especially applicable to the manufacture of printed circuit boards, semiconductor chip lead attachment and packaging multichip modules. The system can be retrofitted onto existing metal treatment ovens, furnaces, welding systems and wave soldering system designs.

  11. Dry soldering with hot filament produced atomic hydrogen

    DOE Patents [OSTI]

    Panitz, J.K.G.; Jellison, J.L.; Staley, D.J.

    1995-04-25T23:59:59.000Z

    A system is disclosed for chemically transforming metal surface oxides to metal that is especially, but not exclusively, suitable for preparing metal surfaces for dry soldering and solder reflow processes. The system employs one or more hot, refractory metal filaments, grids or surfaces to thermally dissociate molecular species in a low pressure of working gas such as a hydrogen-containing gas to produce reactive species in a reactive plasma that can chemically reduce metal oxides and form volatile compounds that are removed in the working gas flow. Dry soldering and solder reflow processes are especially applicable to the manufacture of printed circuit boards, semiconductor chip lead attachment and packaging multichip modules. The system can be retrofitted onto existing metal treatment ovens, furnaces, welding systems and wave soldering system designs. 1 fig.

  12. Hot-stage transmission electron microscopy study of (Na, K)NbO{sub 3} based lead-free piezoceramics

    SciTech Connect (OSTI)

    Lu, Shengbo, E-mail: shengbo.lu@yahoo.com [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong); Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Xu, Zhengkui [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong); Kwok, K. W.; Chan, Helen L. W. [Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

    2014-07-28T23:59:59.000Z

    Hierarchical nanodomains assembled into micron-sized stripe domains, which is believed to be associated with outstanding piezoelectric properties, were observed at room temperature in a typical lead free piezoceramics, (Na{sub 0.52}K{sub 0.48?x})(Nb{sub 0.95?x}Ta{sub 0.05})-xLiSbO{sub 3}, with finely tuned polymorphic phase boundaries (x?=?0.0465) by transmission electron microscopy. The evolution of domain morphology and crystal structure under heating and cooling cycles in the ceramic was investigated by in-situ hot stage study. It is found that the nanodomains are irreversibly transformed into micron-sized rectangular domains during heating and cooling cycles, which lead to the thermal instability of piezoelectric properties of the materials.

  13. RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS

    E-Print Network [OSTI]

    Guo, Zhixiong "James"

    RADIATION HEAT TRANSFER IN TISSUE WELDING AND SOLDERING WITH ULTRAFAST LASERS Kyunghan Kim to incorporate transient radiation heat transfer in tissue welding and soldering with use of ultrafast lasers are performed between laser welding and laser soldering. The use of solder is found to substantially enhance

  14. Mechanical confinement for improved energy storage density in BNT-BT-KNN lead-free ceramic capacitors

    SciTech Connect (OSTI)

    Chauhan, Aditya; Patel, Satyanarayan; Vaish, Rahul, E-mail: rahul@iitmandi.ac.in [School of Engineering, Indian Institute of Technology Mandi, 175 001 (India)

    2014-08-15T23:59:59.000Z

    With the advent of modern power electronics, embedded circuits and non-conventional energy harvesting, the need for high performance capacitors is bound to become indispensible. The current state-of-art employs ferroelectric ceramics and linear dielectrics for solid state capacitance. However, lead-free ferroelectric ceramics propose to offer significant improvement in the field of electrical energy storage owing to their high discharge efficiency and energy storage density. In this regards, the authors have investigated the effects of compressive stress as a means of improving the energy storage density of lead-free ferroelectric ceramics. The energy storage density of 0.91(Bi{sub 0.5}Na{sub 0.5})TiO{sub 3}-0.07BaTiO{sub 3}-0.02(K{sub 0.5}Na{sub 0.5})NbO{sub 3} ferroelectric bulk ceramic was analyzed as a function of varying levels of compressive stress and operational temperature .It was observed that a peak energy density of 387 mJ.cm{sup -3} was obtained at 100 MPa applied stress (25{sup o}C). While a maximum energy density of 568 mJ.cm{sup -3} was obtained for the same stress at 80{sup o}C. These values are indicative of a significant, 25% and 84%, improvement in the value of stored energy compared to an unloaded material. Additionally, material's discharge efficiency has also been discussed as a function of operational parameters. The observed phenomenon has been explained on the basis of field induced structural transition and competitive domain switching theory.

  15. Solder extrusion pressure bonding process and bonded products produced thereby

    DOE Patents [OSTI]

    Beavis, Leonard C. (Albuquerque, NM); Karnowsky, Maurice M. (Albuquerque, NM); Yost, Frederick G. (Ceder Crest, NM)

    1992-01-01T23:59:59.000Z

    Production of soldered joints which are highly reliable and capable of surviving 10,000 thermal cycles between about -40.degree. C. and 110.degree. C. Process involves interposing a thin layer of a metal solder composition between the metal surfaces of members to be bonded and applying heat and up to about 1000 psi compression pressure to the superposed members, in the presence of a reducing atmosphere, to extrude the major amount of the solder composition, contaminants including fluxing gases and air, from between the members being bonded, to form a very thin, strong intermetallic bonding layer having a thermal expansion tolerant with that of the bonded members.

  16. Solder extrusion pressure bonding process and bonded products produced thereby

    DOE Patents [OSTI]

    Beavis, L.C.; Karnowsky, M.M.; Yost, F.G.

    1992-06-16T23:59:59.000Z

    Disclosed is a process for production of soldered joints which are highly reliable and capable of surviving 10,000 thermal cycles between about [minus]40 C and 110 C. Process involves interposing a thin layer of a metal solder composition between the metal surfaces of members to be bonded and applying heat and up to about 1000 psi compression pressure to the superposed members, in the presence of a reducing atmosphere, to extrude the major amount of the solder composition, contaminants including fluxing gases and air, from between the members being bonded, to form a very thin, strong intermetallic bonding layer having a thermal expansion tolerant with that of the bonded members.

  17. Solder technology in the manufacturing of electronic products

    SciTech Connect (OSTI)

    Vianco, P.T.

    1993-08-01T23:59:59.000Z

    The electronics industry has relied heavily upon the use of soldering for both package construction and circuit assembly. The solder attachment of devices onto printed circuit boards and ceramic microcircuits has supported the high volume manufacturing processes responsible for low cost, high quality consumer products and military hardware. Defects incurred during the manufacturing process are minimized by the proper selection of solder alloys, substrate materials and process parameters. Prototyping efforts are then used to evaluate the manufacturability of the chosen material systems. Once manufacturing feasibility has been established, service reliability of the final product is evaluated through accelerated testing procedures.

  18. Droplet Bouncing Behavior in the Direct Solder Bumping Process

    E-Print Network [OSTI]

    Hsiao, Wayne

    This paper presents the results of an ongoing effort to develop a direct solder bumping process for electronics packaging. The proposed process entails delivering molten droplets onto specific locations on electronic devices ...

  19. Solder fatigue reduction in point focus photovoltaic concentrator modules

    SciTech Connect (OSTI)

    Hund, T.D.; Burchett, S.N.

    1991-01-01T23:59:59.000Z

    Solder fatigue tests have been conducted on point focus photovoltaic concentration cell assemblies to identify a baseline fatigue life and to quantify the fatigue life improvements that result using a copper-molybdenum-copper low-expansion insert between the solar cell and copper heat spreader. Solder microstructural changes and fatigue crack growth were identified using cross sections and ultrasonic scans of the fatigue solder joints. The Coffin-Manson and Total Strain fatigue models for low-cycle fatigue were evaluated for use in fatigue life predictions. Since both of these models require strain calculations, two strain calculation methods were compared: hand-calculated shear strain and a finite element method shear strain. At present, the available theoretical models for low-cycle solder fatigue are limited in their ability to predict failure; consequently, extensive thermal cycling is continuing to define the fatigue life for point focus photovoltaic cell assemblies. 9 refs., 9 figs., 2 tabs.

  20. Substrate solder barriers for semiconductor epilayer growth

    DOE Patents [OSTI]

    Drummond, T.J.; Ginley, D.S.; Zipperian, T.E.

    1987-10-23T23:59:59.000Z

    During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In molecular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating. 1 tab.

  1. Substrate solder barriers for semiconductor epilayer growth

    DOE Patents [OSTI]

    Drummond, Timothy J. (Tijeras, NM); Ginley, David S. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

    1989-01-01T23:59:59.000Z

    During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In modular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substrate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating.

  2. Substrate solder barriers for semiconductor epilayer growth

    DOE Patents [OSTI]

    Drummond, T.J.; Ginley, D.S.; Zipperian, T.E.

    1989-05-09T23:59:59.000Z

    During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In modular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substrate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating.

  3. Automatic defect classification of printed wiring board solder joints

    E-Print Network [OSTI]

    Nolan, Daniel J.

    1989-01-01T23:59:59.000Z

    'erent distributions . 23 27 4. 1 Flow chart of inspection process. 29 5. 1 Segmented solder joint. 51 5. 2 Solder joint after edge enhancement and thresholding. 5. 3 Transformation of points on a line. 5. 4 Normal parameterization of s. line. 56 6. 1... works discussing the various benefits of machine recognition of images. Machine vision has been applied in such areas as optical character recognition, satellite image processing, processing of medical images, and automated visual inspection...

  4. au-sn solder joints: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    devices have involved developing structural integrity models for predicting the operating lifetime under vibratory and thermal environmental exposure. Solder joint...

  5. A novel photovoltaic-module assembly system for back contact solar cells using laser soldering technique

    E-Print Network [OSTI]

    A novel photovoltaic-module assembly system for back contact solar cells using laser soldering that the conventional soldering process is still more reliable compared to conductive adhesives or low melting solder alloys. The aim of this work is to combine the reliability of the conventional module assembling

  6. An Overview of Surface Finishes and Their Role in Printed Circuit Board Solderability and Solder Joint Performance

    SciTech Connect (OSTI)

    Vianco, P.T.

    1998-10-15T23:59:59.000Z

    A overview has been presented on the topic of alternative surface finishes for package I/Os and circuit board features. Aspects of processability and solder joint reliability were described for the following coatings: baseline hot-dipped, plated, and plated-and-fused 100Sn and Sn-Pb coatings; Ni/Au; Pd, Ni/Pd, and Ni/Pd/Au finishes; and the recently marketed immersion Ag coatings. The Ni/Au coatings appear to provide the all-around best option in terms of solderability protection and wire bondability. Nickel/Pal ftishes offer a slightly reduced level of performance in these areas that is most likely due to variable Pd surface conditions. It is necessmy to minimize dissolved Au or Pd contents in the solder material to prevent solder joint embrittlement. Ancillary aspects that included thickness measurement techniques; the importance of finish compatibility with conformal coatings and conductive adhesives; and the need for alternative finishes for the processing of non-Pb bearing solders were discussed.

  7. Corrosion Issues in Solder Joint Design and Service

    SciTech Connect (OSTI)

    VIANCO,PAUL T.

    1999-11-24T23:59:59.000Z

    Corrosion is an important consideration in the design of a solder joint. It must be addressed with respect to the service environment or, as in the case of soldered conduit, as the nature of the medium being transported within piping or tubing. Galvanic-assisted corrosion is of particular concern, given the fact that solder joints are comprised of different metals or alloy compositions that are in contact with one-another. The (thermodynamic) potential for corrosion to take place in a particular environment requires the availability of the galvanic series for those conditions and which includes the metals or alloys in question. However, the corrosion kinetics, which actually determine the rate of material loss under the specified service conditions, are only available through laboratory evaluations or field data that are found in the existing literature or must be obtained by in-house testing.

  8. Strength and Lifetime Analysis of SMT Solder Joints: An Exemplary Study of the MiniMELF Component

    E-Print Network [OSTI]

    Berlin,Technische Universität

    626 Strength and Lifetime Analysis of SMT Solder Joints: An Exemplary Study of the Mini, ZT ME 7, Berlin ABSTRACT The reliability and lifetime of SMT solder joints obtained by reflow or wave Since the appearance of surface mount technology (SMT) the reliability and lifetime of solder joints has

  9. Method and apparatus for jetting, manufacturing and attaching uniform solder balls

    DOE Patents [OSTI]

    Yost, Frederick G. (Cedar Crest, NM); Frear, Darrel R. (Albuquerque, NM); Schmale, David T. (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    An apparatus and process for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation of uniform balls for subsequent supply to BGA users.

  10. Method and apparatus for jetting, manufacturing and attaching uniform solder balls

    DOE Patents [OSTI]

    Yost, F.G.; Frear, D.R.; Schmale, D.T.

    1999-01-05T23:59:59.000Z

    An apparatus and process are disclosed for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation of uniform balls for subsequent supply to BGA users. 7 figs.

  11. Microstructural characterization of solders and brazes for advanced packaging technology

    SciTech Connect (OSTI)

    Romig, A.D. Jr.; Frear, D.R.; Hlava, P.F.; Hosking, F.M.; Stephens, J.J.; Vianco, P.T.

    1991-01-01T23:59:59.000Z

    Historically, the electronics industry has always attempted to increase the speed of electronic components and decrease the size of electronic assemblies by developing and manufacturing smaller and faster basic level components (e.g., integrated circuits). However, it is now becoming apparent that the next significant advancement in electronic assembly size and speed may come not as a result of smaller and faster devices, but rather as a consequence of smaller and more closely spaced packages. This increased packaging density will occur at early levels of assembly as industry moves towards multichip modules. It will also occur at later packaging steps as industry continues to expand the use of surface mount technology (SMT) and mixed mounting technology (through hole attachment as well as SMT on one circuit board). Furthermore, there will be an increased propensity to use higher packaging density on printed wiring boards (PWB) and to place more PWB's in a given volume at yet the next level of packaging. One class of materials on which this advanced packaging technology will place severe new demands will be the alloys used to join assemblies and subassemblies (e.g. solders and brazes). These materials will be taxed both from the perspective of enhanced manufacturability as well as greater in-service robustness. It is the objective of this paper, through the use of selected case studies, to illustrate how advanced microstructural characterization techniques can be used to improve packaging technology. The specific case studies discussed are: (1) Microstructural Characterization of Solders, (2) Microstructural Characterization of Solder Joint Embrittlement of Leaded, Surface Mount Transistors (3) Microstructural Characterization of Metal/Ceramic Brazes in Electronic Applications, and (4) Microstructural Characterization of Direct Brazing of Graphite to Copper. 25 refs., 16 figs.

  12. Pb-free Sn-Ag-Cu ternary eutectic solder

    DOE Patents [OSTI]

    Anderson, I.E.; Yost, F.G.; Smith, J.F.; Miller, C.M.; Terpstra, R.L.

    1996-06-18T23:59:59.000Z

    A Pb-free solder includes a ternary eutectic composition consisting essentially of about 93.6 weight % Sn-about 4.7 weight % Ag-about 1.7 weight % Cu having a eutectic melting temperature of about 217 C and variants of the ternary composition wherein the relative concentrations of Sn, Ag, and Cu deviate from the ternary eutectic composition to provide a controlled melting temperature range (liquid-solid ``mushy`` zone) relative to the eutectic melting temperature (e.g. up to 15 C above the eutectic melting temperature). 5 figs.

  13. Characterization and optimization of a Hot Air Solder-Leveling System

    SciTech Connect (OSTI)

    Penniston, R.R. Jr.; Stockdale, D.A.

    1993-03-01T23:59:59.000Z

    The characterization and optimization of a new Hot Air Sokkr-Leveling (HASL) System in the Printed Wiring Board Fabrication Area was initiated to reduce the variability and defects in printed wiring board solder coatings. This body of work continues to provide information on the mechanics of solder coating, and allows us to predict the required process adjustments based on board type and geometry. The previous HASL system contained several processes (flux, preheat, solder-coat, cooldown) within one piece of equipment. The new system physically separates these processes using in-line conveyors. Parameters affecting these processes were brainstormed and evaluated using the MaHo Perez-Wilson methodology (MPCpS). The critical parameters were identified and segregated according to individual process. Each process was characterized for materials used, machine settings, and their effect (potential and actual) on product. Due to the wide-ranging affect of the preheat and solder-leveling machine settings, the first decision made was to restrict the characterization to duplication of the coating obtained from the previous system. Adoption of the parameters used on the previous system allowed a reduction in the number of evaluations required to establish initial machine settings (solder pot dwell times, solder temperature, preheat temperature, etc.). Activities in-work include a formal statistical analysis of the solder-leveling capabilities, and completion of Optimization activities.

  14. Modeling and implementation of solder-activated joints for single actuator, centimeter-scale robotic mechanisms

    E-Print Network [OSTI]

    Telleria, Maria J

    2010-01-01T23:59:59.000Z

    This thesis explains when, and why, solder-based phase change materials (PCMs) are best-suited as a means to modify a robotic mechanism's kinematic and elastomechanic behavior. The preceding refers to mechanisms that possess ...

  15. Understanding, Modeling and Predicting Hidden Solder Joint Shape Using Active Thermography

    E-Print Network [OSTI]

    Giron Palomares, Jose

    2012-07-16T23:59:59.000Z

    Characterizing hidden solder joint shapes is essential for electronics reliability. Active thermography is a methodology to identify hidden defects inside an object by means of surface abnormal thermal response after applying a heat flux...

  16. Effects of surface properties on solder bump formation by direct droplet deposition

    E-Print Network [OSTI]

    Hsiao, Wen Kai, 1972-

    2004-01-01T23:59:59.000Z

    Recent advances in microdroplet generation and deposition processes have made it possible to directly form solder bumps on integrated circuits using micron-sized molten metal droplets. The direct droplet deposition bumping ...

  17. Root cause analysis of solder flux residue incidence in the manufacture of electronic power modules

    E-Print Network [OSTI]

    Jain, Pranav

    2011-01-01T23:59:59.000Z

    This work investigates the root causes of the incidence of solder flux residue underneath electronic components in the manufacture of power modules. The existing deionized water-based centrifugal cleaning process was ...

  18. Get the LEAD Out!Most lead-containing autoclave tape has stripes running across at an angle ( / / / / / / ); if it has very faint text (the word "autoclaved"), it most likely is a lead-free alternative.

    E-Print Network [OSTI]

    Ford, James

    Get the LEAD Out!Most lead-containing autoclave tape has stripes running across at an angle ( / / / / / / ); if it has very faint text (the word "autoclaved"), it most likely is a lead-free alternative. ADDITIONAL Programs Office (650.723.0110) REPLACE lead-containing rolls of auto- clave tape with a non-lead containing

  19. Effect of gold-nickel metallization microstructure on fluxless soldering

    SciTech Connect (OSTI)

    Cinque, R.B.; Morris, J.W. Jr. (Lawrence Berkeley Lab., CA (United States) Univ. of California, Berkeley, CA (United States))

    1994-06-01T23:59:59.000Z

    Gold plating is used in the microelectronics industry to maintain the wettability of metal substrates. The nature of wetting during soldering of gold plated metals is discussed, and the results of experiments on the fluxless wettability and oxidation of gold plated nickel are described. The results suggest that electrodeposition of a thin gold plate (0.14 [mu]m) and the concurrent reduction of nickel oxide produce a gold-nickel system which will wet without flux. Oxidation of nickel was observed to occur via nickel out-diffusion and by direct exposure of the substrate through pinhole plating defects. Auger chemical analysis indicates that pinholes do not produce oxidation of the surrounding substrate area. 20 refs., 10 figs.

  20. Evaluation of low-residue soldering for military and commercial applications: A report from the Low-Residue Soldering Task Force

    SciTech Connect (OSTI)

    Iman, R.L.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States); Burress, R.V. [SEHO (United States)] [and others

    1995-06-01T23:59:59.000Z

    The LRSTF combined the efforts of industry, military, and government to evaluate low-residue soldering processes for military and commercial applications. These processes were selected for evaluation because they provide a means for the military to support the presidential mandate while producing reliable hardware at a lower cost. This report presents the complete details and results of a testing program conducted by the LRSTF to evaluate low-residue soldering for printed wiring assemblies. A previous informal document provided details of the test plan used in this evaluation. Many of the details of that test plan are contained in this report. The test data are too massive to include in this report, however, these data are available on disk as Excel spreadsheets upon request. The main purpose of low-residue soldering is to eliminate waste streams during the manufacturing process.

  1. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K???Bi???TiO?-BaTiO?-Na???Bi???TiO? piezoelectric materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26T23:59:59.000Z

    We synthesized grain-oriented lead-free piezoelectric materials in (K???Bi???TiO?-BaTiO?-xNa???Bi???TiO? (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d?? ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectricmore »materials.« less

  2. IEEE TRANSACTIONS ON MAGNETICS, VOL. 46, NO. 6, JUNE 2010 2187 Novel Solder-Magnetic Particle Composites and

    E-Print Network [OSTI]

    McHenry, Michael E.

    Terms--Electromagnetic induction heating, infrared imaging, magnetic nanoparticles, solder reflow. I University, Pittsburgh, PA 15213 USA Intel Corporation, Chandler, AZ 85226 USA Localized heating of solder reflow process, where the package is subjected to high temperatures. Localized heating is possible

  3. The role of eddy currents and nanoparticle size on AC magnetic fieldinduced reflow in solder/magnetic nanocomposites

    E-Print Network [OSTI]

    McHenry, Michael E.

    The role of eddy currents and nanoparticle size on AC magnetic field­induced reflow in solder://jap.aip.org/about/rights_and_permissions #12;The role of eddy currents and nanoparticle size on AC magnetic field­induced reflow in solder be derived from eddy current losses in Cu planes in the substrate board. Eddy current heating in Cu sheets

  4. In-situ study of electromigration-induced grain rotation in Pb-free solder joint by synchrotron microdiffraction

    SciTech Connect (OSTI)

    Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

    2008-10-31T23:59:59.000Z

    The rotation of Sn grains in Pb-free flip chip solder joints hasn't been reported in literature so far although it has been observed in Sn strips. In this letter, we report the detailed study of the grain orientation evolution induced by electromigration by synchrotron based white beam X-ray microdiffraction. It is found that the grains in solder joint rotate more slowly than in Sn strip even under higher current density. On the other hand, based on our estimation, the reorientation of the grains in solder joints also results in the reduction of electric resistivity, similar to the case of Sn strip. We will also discuss the reason why the electric resistance decreases much more in strips than in the Sn-based solders, and the different driving force for the grain growth in solder joint and in thin film interconnect lines.

  5. Design of Experiments to Determine Causes of Flex Cable Solder Wicking, Discoloration and Hole Location Defects

    SciTech Connect (OSTI)

    Wolfe, Larry

    2009-04-22T23:59:59.000Z

    Design of Experiments (DoE) were developed and performed in an effort to discover and resolve the causes of three different manufacturing issues; large panel voids after Hot Air Solder Leveling (HASL), cable hole locations out of tolerance after lamination and delamination/solder wicking around flat flex cable circuit lands after HASL. Results from a first DoE indicated large panel voids could be eliminated by removing the pre-HASL cleaning. It also revealed eliminating the pre-HASL bake would not be detrimental when using a hard press pad lamination stackup. A second DoE indicated a reduction in hard press pad stackup lamination pressure reduced panel stretch in the y axis approximately 70%. A third DoE illustrated increasing the pre-HASL bake temperature could reduce delamination/solder wicking when using a soft press pad lamination stackup.

  6. Sensitivity of Solder Joint Fatigue to Sources of Variation in Advanced Vehicular Power Electronics Cooling

    SciTech Connect (OSTI)

    Vlahinos, A.; O'Keefe, M.

    2010-06-01T23:59:59.000Z

    This paper demonstrates a methodology for taking variation into account in thermal and fatigue analyses of the die attach for an inverter of an electric traction drive vehicle. This method can be used to understand how variation and mission profile affect parameters of interest in a design. Three parameters are varied to represent manufacturing, material, and loading variation: solder joint voiding, aluminum nitride substrate thermal conductivity, and heat generation at the integrated gate bipolar transistor. The influence of these parameters on temperature and solder fatigue life is presented. The heat generation loading variation shows the largest influence on the results for the assumptions used in this problem setup.

  7. Assessment of Solder Interconnect Integrity in Dismantled Electronic Components from N57 and B61 Tube-Type Radars

    SciTech Connect (OSTI)

    Rejent, J.A.; Vianco, P.T.; Woodrum, R.A.

    1999-07-01T23:59:59.000Z

    Aging analyses were performed on solder joints from two radar units: (1) a laboratory, N57 tube-type radar unit and (2) a field-returned, B61-0, tube-type radar unit. The cumulative temperature environments experienced by the units during aging were calculated from the intermetallic compound layer thickness and the mean Pb-rich phase particle size metrics for solder joints in the units, assuming an aging time of 35 years for both radars. Baseline aging metrics were obtained from a laboratory test vehicle assembled at AS/FM and T; the aging kinetics of both metrics were calculated from isothermal aging experiments. The N57 radar unit interconnect board solder joints exhibited very little aging. The eyelet solder joints did show cracking that most likely occurred at the time of assembly. The eyelet, SA1126 connector solder joints, showed some delamination between the Cu pad and underlying laminate. The B61 field-returned radar solder joints showed a nominal degree of aging. Cracking of the eyelet solder joints was observed. The Pb-rich phase particle measurements indicated additional aging of the interconnects as a result of residual stresses. Cracking of the terminal pole connector, pin-to-pin solder joint was observed; but it was not believed to jeopardize the electrical functionality of the interconnect. Extending the stockpile lifetime of the B61 tube-type radar by an additional 20 years would not be impacted by the reliability of the solder joints with respect to further growth of the intermetallic compound layer. Additional coarsening of the Pb-rich phase will increase the joints' sensitivity to thermomechanical fatigue.

  8. Influence of transient flow and solder bump resistance on underfill process , W.J. Zhangb,

    E-Print Network [OSTI]

    Zhang, WJ "Chris"

    . In the study for a capillary flow within a tube reported by Newman [12], for a horizontal capillary flowU N C O R R EC TED PR O O F Influence of transient flow and solder bump resistance on underfill The underfill flow process is one of the important steps in Microsystems technology. One of the best known

  9. Microstructural Coarsening during Thermomechanical Fatigue and Annealing of Micro Flip-Chip Solder Joints

    SciTech Connect (OSTI)

    Barney, Monica M.

    1998-12-01T23:59:59.000Z

    Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by 1,000 cycles, despite undergoing less coarsening than the annealed samples. The high-strain cycled samples experienced a 28% strain and failed between 25 and 250 cycles. No failures were observed in the annealed samples. Failure mechanisms and processing issues unique to small, fine pitch joints are also discussed.

  10. 3-Dimensional, Solder-Free Interconnect Technology for High-Performance Power Modules

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , published in "Conference on Integrated Power Systems (CIPS), Nuremberg : Germany (2012)" #12;dimensional (3D) packaging of power modules in a compact stacked layer structure [3], [4], [5]. The proposed technologies can3-Dimensional, Solder-Free Interconnect Technology for High- Performance Power Modules Bassem

  11. Reliability of Nano-Structured Nickel Interconnections Replacing FlipChip Solder Assembly without Underfill

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    Reliability of Nano-Structured Nickel Interconnections Replacing FlipChip Solder Assembly without nano-structured nickel as the primary interconnection material. Assembly was accomplished materials such as nanostructured copper and nickel, novel bonding and barrier layers to provide both

  12. Statistical analysis of data from the solderability testing of electroless nickel plated Kovar leads

    SciTech Connect (OSTI)

    Fisher, R.E.; Hall, I.J.

    1986-01-01T23:59:59.000Z

    Many Sandia National Laboratories components require electrical leads to be soldered to an assembly such as a printed wiring board. In late 1982, a supplier reported to Sandia that they had problems soldering leads of a 14/16 pin integrated circuit flatpack to printed wiring boards. These problems led to the investigation described herein of the fluxes used in solder-dipping. This study shows that Alpha 611 flux, used by the supplier, is not active enough to wet an electroless nickel-plated surface that has been exposed to 200C for 16 hours (which is a condition seen in production prior to soldering). Two Blackstone fluxes included in the study did provide uniform wetting in this situation and also for room temperature curing, even though the time in flux ranged from .25 to 10 minutes. Blackstone 642 flux had a higher wetting rate and lower contact angle than Blackstone 2508. However, Flux residues of B-642 contain chloride ions; therefore, B-2508 has now been adopted by the supplier.

  13. Damage mechanics characterization on fatigue behavior of a solder joint material

    SciTech Connect (OSTI)

    Chow, C.L.; Yang, F. [Univ. of Michigan, Dearborn, MI (United States). Dept. of Mechanical Engineering; Fang, H.E. [Sandia National Labs., Albuquerque, NM (United States). Computational Physics Dept.

    1998-08-01T23:59:59.000Z

    This paper presents the first part of a comprehensive mechanics approach capable of predicting the integrity and reliability of solder joint material under fatigue loading without viscoplastic damage considerations. A separate report will be made to present a comprehensive damage model describing life prediction of the solder material under thermomechanical fatigue loading. The method is based on a theory of damage mechanics which makes possible a macroscopic description of the successive material deterioration caused by the presence of microcracks/voids in engineering materials. A damage mechanics model based on the thermodynamic theory of irreversible processes with internal state variables is proposed and used to provide a unified approach in characterizing the cyclic behavior of a typical solder material. With the introduction of a damage effect tensor, the constitutive equations are derived to enable the formulation of a fatigue damage dissipative potential function and a fatigue damage criterion. The fatigue evolution is subsequently developed based on the hypothesis that the overall damage is induced by the accumulation of fatigue and plastic damage. This damage mechanics approach offers a systematic and versatile means that is effective in modeling the entire process of material failure ranging from damage initiation and propagation leading eventually to macro-crack initiation and growth. As the model takes into account the load history effect and the interaction between plasticity damage and fatigue damage, with the aid of a modified general purpose finite element program, the method can readily be applied to estimate the fatigue life of solder joints under different loading conditions.

  14. Energy Blog | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    May 24, 2012 Lab Breakthrough: Lead-free Solder Iver Anderson, Ames National Laboratory materials scientist, discusses the impact of a lead-free solder he invented 15 years ago,...

  15. LCD, low-temperature soldering and compound semiconductor : the sources, market, applications and future prospects of indium in Malaysia

    E-Print Network [OSTI]

    Yong, Foo Nun

    2006-01-01T23:59:59.000Z

    Indium is a minor but very valuable metal. Decreasing supplies of indium from refining and increasing demands from LCD, low-temperature soldering and compound semiconductors have stimulated the indium price increase ...

  16. The Interaction Between an Imposed Current and the Creep of Idealized Sn-Ag-Cu Solder Interconnects

    E-Print Network [OSTI]

    Kinney, Christopher; Lee, Tae-Kyu; Liu, Kuo-Chuan; Morris, J. W.

    2009-01-01T23:59:59.000Z

    heating because prior thermal mapping of the joint done with an infrared (heating, the temperature of the solder joint was measured by attaching a thermocouple, and con?rmed by infrared

  17. Spreading of Sn-Ag solders on FeNi alloys

    SciTech Connect (OSTI)

    Saiz, Eduardo; Hwang, C-W.; Suganuma, Katsuaki; Tomsia, Antoni P.

    2003-02-28T23:59:59.000Z

    The spreading of Sn-3Ag-xBi solders on Fe-42Ni has been studied using a drop transfer setup. Initial spreading velocities as fast as {approx}0.5 m/s have been recorded. The results are consistent with a liquid front moving on a metastable, flat, unreacted substrate and can be described by using a modified molecular-kinetic model for which the rate controlling step is the movement of one atom from the liquid to the surface of the solid substrate. Although the phase diagram predicts the formation of two Fe-Sn intermetallics at the solder/substrate interface in samples heated at temperatures lower than 513 C, after spreading at 250 C only a thin FeSn reaction layer could be observed. Two interfacial layers (FeSn and FeSn2) were found after spreading at 450 C.

  18. Dual-enhancement of ferro-/piezoelectric and photoluminescent performance in Pr{sup 3+} doped (K{sub 0.5}Na{sub 0.5})NbO{sub 3} lead-free ceramics

    SciTech Connect (OSTI)

    Wei, Yongbin; Jia, Yanmin, E-mail: wuzheng@zjnu.cn, E-mail: ymjia@zjnu.edu.cn; Wu, Jiang; Shen, Yichao [Department of Physics, Zhejiang Normal University, Jinhua 321004 (China); Wu, Zheng, E-mail: wuzheng@zjnu.cn, E-mail: ymjia@zjnu.edu.cn [College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004 (China); Luo, Haosu [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2014-07-28T23:59:59.000Z

    A mutual enhancement action between the ferro-/piezoelectric polarization and the photoluminescent performance of rare earth Pr{sup 3+} doped (K{sub 0.5}Na{sub 0.5})NbO{sub 3} (KNN) lead-free ceramics is reported. After Pr{sup 3+} doping, the KNN ceramics exhibit the maximum enhancement of ?1.2 times in the ferroelectric remanent polarization strength and ?1.25 times in the piezoelectric coefficient d{sub 33}, respectively. Furthermore, after undergoing a ferro-/piezoelectric polarization treatment, the maximum enhancement of ?1.3 times in photoluminescence (PL) was observed in the poled 0.3% Pr{sup 3+} doped sample. After the trivalent Pr{sup 3+} unequivalently substituting the univalent (K{sub 0.5}Na{sub 0.5}){sup +}, A-sites ionic vacancies will occur to maintain charge neutrality, which may reduce the inner stress and ease the domain wall motions, yielding to the enhancement in ferro-/piezoelectric performance. The polarization-induced enhancement in PL is attributed to the decrease of crystal symmetry abound the Pr{sup 3+} ions after polarization. The dual-enhancement of the ferro-/piezoelectric and photoluminescent performance makes the Pr{sup 3+} doped KNN ceramic hopeful for piezoelectric/luminescent multifunctional devices.

  19. Structures, electrical properties, and leakage current behaviors of un-doped and Mn-doped lead-free ferroelectric K{sub 0.5}Na{sub 0.5}NbO{sub 3} films

    SciTech Connect (OSTI)

    Wang, Lingyan, E-mail: l.y.wang@mail.xjtu.edu.cn, E-mail: wren@mail.xjtu.edu.cn; Ren, Wei, E-mail: l.y.wang@mail.xjtu.edu.cn, E-mail: wren@mail.xjtu.edu.cn; Shi, Peng; Wu, Xiaoqing [Electronic Material Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049 (China)

    2014-01-21T23:59:59.000Z

    Lead-free ferroelectric un-doped and doped K{sub 0.5}Na{sub 0.5}NbO{sub 3} (KNN) films with different amounts of manganese (Mn) were prepared by a chemical solution deposition method. The thicknesses of all films are about 1.6??m. Their phase, microstructure, leakage current behavior, and electrical properties were investigated. With increasing the amounts of Mn, the crystallinity became worse. Fortunately, the electrical properties were improved due to the decreased leakage current density after Mn-doping. The study on leakage behaviors shows that the dominant conduction mechanism at low electric field in the un-doped KNN film is ohmic mode and that at high electric field is space-charge-limited and Pool-Frenkel emission. After Mn doping, the dominant conduction mechanism at high electric field of KNN films changed single space-charge-limited. However, the introduction of higher amount of Mn into the KNN film would lead to a changed conduction mechanism from space-charge-limited to ohmic mode. Consequently, there exists an optimal amount of Mn doping of 2.0?mol.?%. The 2.0?mol.?% Mn doped KNN film shows the lowest leakage current density and the best electrical properties. With the secondary ion mass spectroscopies and x-ray photoelectron spectroscopy analyses, the homogeneous distribution in the KNN films and entrance of Mn element in the lattice of KNN perovskite structure were also confirmed.

  20. Tin-Based Reactive Solders for Ceramic/Metal Joints RAKESH R. KAPOOR and THOMAS W . EAGAR

    E-Print Network [OSTI]

    Eagar, Thomas W.

    ( { ) Tin-Based Reactive Solders for Ceramic/Metal Joints RAKESH R. KAPOOR and THOMAS W . EAGAR engine com- ponents), wear parts, tool materials, electrical feed- throughs, and metal contacts on ceramics. To overcome this problem, reactive metals are added to the filler metai.11- 181These reactive

  1. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K0.5Bi0.5TiO3-BaTiO3-Na0.5Bi0.5TiO3 piezoelectric materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26T23:59:59.000Z

    We synthesized grain-oriented lead-free piezoelectric materials in (K0.5Bi0.5TiO3-BaTiO3-Na0.5Bi0.5TiO3 (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (,0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d33 , 190pC/N) and high temperature stability (,1606C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-1806 domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectricmore »materials.« less

  2. An evaluation of the spring finger solder joints on SA1358-10 and SA2052-4 connector assemblies (MC3617,W87).

    SciTech Connect (OSTI)

    Kilgo, Alice C.; Vianco, Paul Thomas; Hlava, Paul Frank; Zender, Gary L.

    2006-08-01T23:59:59.000Z

    The SA1358-10 and SA2052-4 circular JT Type plug connectors are used on a number of nuclear weapons and Joint Test Assembly (JTA) systems. Prototype units were evaluated for the following specific defects associated with the 95Sn-5Sb (Sn-Sb, wt.%) solder joint used to attach the beryllium-copper (BeCu) spring fingers to the aluminum (Al) connector shell: (1) extended cracking within the fillet; (2) remelting of the solder joint during the follow-on, soldering step that attached the EMR adapter ring to the connector shell (and/or soldering the EMR shell to the adapter ring) that used the lower melting temperature 63Sn-37Pb (Sn-Pb) alloy; and (3) spalling of the Cd (Cr) layer overplating layer from the fillet surface. Several pedigrees of connectors were evaluated, which represented older fielded units as well as those assemblies that were recently constructed at Kansas City Plant. The solder joints were evaluated that were in place on connectors made with the current soldering process as well as an alternative induction soldering process for attaching the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely the EMR adapter ring to the shell. Very similar observations were made, which crossed the different pedigrees of parts and processes. The extent of cracking in the top side fillets varied between the different connector samples and likely reflected the different extents to which the connector was mated to its counterpart assembly. In all cases, the spring finger solder joints on the SA1358-10 connectors were remelted as a result of the subsequent EMR adapter ring attachment process. Spalling of the Cd (Cr) overplating layer was also observed for these connectors, which was a consequence of the remelting activity. On the other hand, the SA2052-4 connector did not exhibit evidence of remelting of the spring finger solder joint. The Cd (Cr) layer did not show signs of spalling. These results suggested that, due to the size of the SA1358-10 connector, any of the former or current soldering processes used to attach the EMR adapter ring and/or EMR shell to the connector shell, requires a level of heat energy that will always result in the remelting of the spring finger solder joint attached with either the Sn-Ag or the Sn-Sb alloy. Lastly, it was construed that the induction soldering process, which is used to attach the EMR adapter ring onto the shell, was more likely to have caused the remelting event rather than the more localized heat source of the hand soldering iron used to attach the EMR shell to the adapter ring.

  3. Contributions Of Stress And Oxidation On The Formation Of Whiskers In Pb-Free Solders

    SciTech Connect (OSTI)

    Duncan, A. J.; Hoffman, E. N.

    2014-03-25T23:59:59.000Z

    This report summarizes the research activities of WP-1754. The study focusses on the environmental factors influencing formation of lead free whiskers on electrodeposited tin coatings over copper (or copper containing) substrates. Much of the initial results are summarized in an interim report. From the initial results, two main areas were chosen to be the focus of additional research: the demonstration of effects of elastic stress state in the nucleation of whiskers and the confirmation of the effect of oxygen/nitrogen ratio in the formation of whiskers. Different levels of elastic stress were induced with the incorporation of a custom designed fixture that loaded the substrates in a four-point bending configuration and were maintained in an environmental chamber under conditions deemed favorable for whisker growth. The results show that induced elastic stress slightly increased the concentration of nucleation sites of whiskers. The effects of oxygen content were studied by aging substrates in gas vials of varying absolute pressure and different oxygen/nitrogen ratios. The concentration of whiskers were measured and appear to be sensitive to absolute pressure but are not sensitive to oxygen content (as previously observed).

  4. Gelatin based on Power-gel.TM. as solders for Cr.sup.4+laser tissue welding and sealing of lung air leak and fistulas in organs

    DOE Patents [OSTI]

    Alfano, Robert R.; Tang, Jing; Evans, Jonathan M.; Ho, Peng Pei

    2006-04-25T23:59:59.000Z

    Laser tissue welding can be achieved using tunable Cr.sup.4+ lasers, semiconductor lasers and fiber lasers, where the weld strength follows the absorption spectrum of water. The use of gelatin and esterified gelatin as solders in conjunction with laser inducted tissue welding impart much stronger tensile and torque strengths than albumin solders. Selected NIR wavelength from the above lasers can improve welding and avoid thermal injury to tissue when used alone or with gelatin and esterified gelatin solders. These discoveries can be used to enhance laser tissue welding of tissues such as skin, mucous, bone, blood vessel, nerve, brain, liver, pancreas, spleen, kidney, lung, bronchus, respiratory track, urinary tract, gastrointestinal tract, or gynecologic tract and as a sealant for pulmonary air leaks and fistulas such as intestinal, rectal and urinary fistulas.

  5. A new Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} based lead-free piezoelectric system with calculated end-member Bi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3}

    SciTech Connect (OSTI)

    Liu, Feng [The Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wahyudi, Olivia; Li, Yongxiang, E-mail: yxli@mail.sic.ac.cn [The Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2014-03-21T23:59:59.000Z

    The phase structure, dielectric and piezoelectric properties of a new lead-free piezoelectric system (1???x)Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}–xBi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3} [(1???x)BNT–xBZH, x?=?0, 0.01, 0.02, 0.03, and 0.04] were investigated. The structure of Bi(Zn{sub 0.5}Hf{sub 0.5})O{sub 3} was calculated using first-principles method and (1???x)BNT–xBZH ceramics were fabricated by conventional solid-state process. At room temperature, a morphotropic phase boundary (MPB) from rhombohedral to pseudocubic is identified near x?=?0.02 by the analysis of X-ray diffraction patterns. The ceramics with MPB near room temperature exhibit excellent electrical properties: the Curie temperature, maximum polarization, remnant polarization, and coercive field are 340?°C, 56.3??C/cm{sup 2}, 43.5??C/cm{sup 2}, and 5.4?kV/mm, respectively, while the maximum positive bipolar strain and piezoelectric coefficient are 0.09% and 92 pC/N, respectively. In addition, a linear relationship between the MPB phase boundary composition and the calculated tetragonality of non-BNT end-member was demonstrated. Thus, this study not only shows a new BNT-based lead-free piezoelectric system but also suggest a new way to predict the composition at MPB a priori when designing new lead-free piezoelectric system.

  6. Ames Lab 101: Technology Transfer

    ScienceCinema (OSTI)

    Covey, Debra

    2012-08-29T23:59:59.000Z

    Ames Laboratory Associate Laboratory Director, Sponsored Research Administration, Debra Covey discusses technology transfer. Covey also discusses Ames Laboratory's most successful transfer, lead-free solder.

  7. Process for reducing series resistance of solar-cell metal-contact systems with a soldering-flux etchant

    DOE Patents [OSTI]

    Coyle, R.T.; Barrett, J.M.

    1982-05-04T23:59:59.000Z

    Disclosed is a process for substantially reducing the series resistance of a solar cell having a thick film metal contact assembly thereon while simultaneously removing oxide coatings from the surface of the assembly prior to applying solder therewith. The process includes applying a flux to the contact assembly and heating the cell for a period of time sufficient to substantially remove the series resistance associated with the assembly by etching the assembly with the flux while simultaneously removing metal oxides from said surface of said assembly.

  8. Effect of composition on electrical properties of lead-free Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} piezoelectric ceramics

    SciTech Connect (OSTI)

    Jaita, Pharatree [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Watcharapasorn, Anucha; Jiansirisomboon, Sukanda [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-14T23:59:59.000Z

    Lead-free piezoelectric ceramics with the composition of (1-x)Bi{sub 0.5}(Na{sub 0.80}K{sub 0.20}){sub 0.5}TiO{sub 3}-x(Ba{sub 0.98}Nd{sub 0.02})TiO{sub 3} or (1-x) BNKT-xBNdT (with x = 0-0.20 mol fraction) have been synthesized by a conventional mixed-oxide method. The compositional dependence of phase structure and electrical properties of the ceramics were systemically studied. The optimum sintering temperature of all BNKT-BNdT ceramics was found to be 1125 Degree-Sign C. X-ray diffraction pattern suggested that BNdT effectively diffused into BNKT lattice during sintering to form a solid solution with a perovskite structure. Scanning electron micrographs showed a slight reduction of grain size when BNdT was added. It was found that BNKT-0.10BNdT ceramic exhibited optimum electrical properties ({epsilon}{sub r} = 1716, tan{delta} = 0.0701, T{sub c} = 327 Degree-Sign C, and d{sub 33} = 211 pC/N), suggesting that this composition has a potential to be one of a promising lead-free piezoelectric candidate for dielectric and piezoelectric applications.

  9. Growth of a Au-Ni-Sn intermetallic compound on the solder-substrate interface after aging

    SciTech Connect (OSTI)

    Minor, Andrew M.; Morris, J.W., Jr.

    1999-12-16T23:59:59.000Z

    Au/Ni metallization has become increasingly common in microelectronic packaging when Cu pads are joined with Pb-Sn solder. The outermost Au layer serves to protect the pad from corrosion and oxidation and the Ni layer provides a diffusion barrier to inhibit detrimental growth of Cu-Sn intermetallics. As a result of reflowing eutectic Pb-Sn on top of Au/Ni metallization, the as-solidified joints have AuSn{sub 4} precipitates distributed throughout the bulk of the solder joint, and Ni{sub 3}Sn{sub 4} intermetallics at the interface. Recent work has shown that the Au-Sn redeposits onto the interface during aging, compromising the strength of the joint. The present work shows that the redeposited intermetallic layer is a ternary compound with stoichiometry Au{sub 0.5}Ni{sub 0.5}Sn{sub 4}. The growth of this intermetallic layer was investigated, and results show that the ternary compound is observed to grow after as little as 3 hours at 150 C and after 3 weeks at 150 C has grown to a thickness of 10 {micro}m. Additionally, methods for inhibiting the growth of the ternary layer were investigated and it was determined that multiple reflows, both with and without additional aging can substantially limit the thickness of the ternary layer.

  10. Lead-free Thin Film Piezoelectric Devices - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -of Energy LastLawrenceLawsE C H N

  11. An analysis of lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic for efficient refrigeration and thermal energy harvesting

    SciTech Connect (OSTI)

    Vats, Gaurav; Vaish, Rahul, E-mail: rahul@iitmandi.ac.in [School of Engineering, Indian Institute of Technology Mandi, Himachal Pradesh 175 001 (India); Bowen, Chris R. [Department of Mechanical Engineering, Materials Research Centre, University of Bath, Bath BA2 7AY (United Kingdom)

    2014-01-07T23:59:59.000Z

    This article demonstrates the colossal energy harvesting capability of a lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic using the Olsen cycle. The maximum harvestable energy density estimated for this system is found to be 1523?J/L (1523?kJ/m{sup 3}) where the results are presented for extreme ambient conditions of 20–160?°C and electric fields of 0.1–4 MV/m. This estimated energy density is 1.7 times higher than the maximum reported to date for the lanthanum-doped lead zirconate titanate (thin film) system. Moreover, this study introduces a generalized and effective solid state refrigeration cycle in contrast to the ferroelectric Ericson refrigeration cycle. The cycle is based on a temperature induced polarization change on application of an unipolar electric field to ferroelectric ceramics.

  12. Polar nanoregions and dielectric properties in high-strain lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-0.07BaTiO{sub 3} piezoelectric single crystals

    SciTech Connect (OSTI)

    Chen, Cheng-Sao, E-mail: rickchen@cc.hwh.edu.tw [Department of Mechanical Engineering, Hwa-Hsia Institute of Technology, New Taipei City 23567, Taiwan (China); Chen, Pin-Yi [Department of Mechanical Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan (China); Tu, Chi-Shun [Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China)

    2014-01-07T23:59:59.000Z

    A structural coexistence of rhombohedral (R) and tetragonal (T) phases has been revealed in the (001){sub c}-cut lead-free 0.93(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}–0.07BaTiO{sub 3} (BNB7T) piezoelectric crystals, which grown by the self-flux method, in the lower temperatures by high-resolution synchrotron X-ray diffraction, reciprocal space mapping, and transmission electron microscopy. The dielectric permittivity exhibits a thermal hysteresis in the region of 120–260?°C, implying a first-order-like phase transition from R+T to T. The real part (??) of dielectric permittivity begins to deviates from the Curie-Weiss equation, ???=?C/(T ? T{sub o}), from the Burns temperature T{sub B}?=?460?°C, below which the polar nanoregions (or nanoclusters) develop and attenuate dielectric responses. The polar nanoregions of 5–10?nm were revealed by high-resolution transmission electron microscope. The normal piezoelectric coefficient d{sub 33} exhibits a rapid increase at E?=?15–20?kV/cm and reaches a maximum of d{sub 33} ?450 pC/N. The high piezoelectric response and E-field induced strain in BNB7T single crystals can be attributed to structural phase transitions under an E-field application.

  13. New Reliability Assessment Method for Solder Joints in BGA Package by Considering the Interaction between Design Factors

    E-Print Network [OSTI]

    Satoshi Kondo; Qiang Yu; T. Shibutani; M. Shiratori

    2008-01-07T23:59:59.000Z

    As the integration and the miniaturization of electronics devices, design space become narrower and interactions between design factors affect their reliability. This paper presents a methodology of quantifying the interaction of each design factor in electronics devices. Thermal fatigue reliability of BGA assembly was assessed with the consideration of the interaction between design factors. Sensitivity analysis shows the influence of each design factor to inelastic strain range of a solder joint characterizing the thermal fatigue life if no interaction occurs. However, there is the interaction in BGA assembly since inelastic strain range depends on not only a mismatch in CTE but also a warpage of components. Clustering can help engineers to clarify the relation between design factors. The variation in the influence was taken to quantify the interaction of each design factor. Based on the interaction, simple evaluating approach of inelastic strain range for the BGA assembly was also developed. BGA package was simplified into a homogeneous component and equivalent CTE wascalculated from the warpage of BGA and PCB. The estimated equation was derived by using the response surface method as a function of design factors. Based upon these analytical results, design engineers can rate each factor's effect on reliability and assess the reliability of their basic design plan at the concept design stage.

  14. Domain wall motion and electromechanical strain in lead-free piezoelectrics: Insight from the model system (1 ? x)Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} using in situ high-energy X-ray diffraction during application of electric fields

    SciTech Connect (OSTI)

    Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Li, Binzhi [Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, California 95616 (United States); Bowman, Keith [Illinois Institute of Technology, Armour College of Engineering, Chicago, Illinois 60616 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Jones, Jacob L., E-mail: JacobJones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-04-14T23:59:59.000Z

    The piezoelectric compositions (1 ? x)Ba(Zr{sub 0.2}Ti{sub 0.8})O{sub 3}–x(Ba{sub 0.7}Ca{sub 0.3})TiO{sub 3} (BZT-xBCT) span a model lead-free morphotropic phase boundary (MPB) between room temperature rhombohedral and tetragonal phases at approximately x?=?0.5. In the present work, in situ X-ray diffraction measurements during electric field application are used to elucidate the origin of electromechanical strain in several compositions spanning the tetragonal compositional range 0.6???x???0.9. As BCT concentration decreases towards the MPB, the tetragonal distortion (given by c/a-1) decreases concomitantly with an increase in 90° domain wall motion. The increase in observed macroscopic strain is predominantly attributed to the increased contribution from 90° domain wall motion. The results demonstrate that domain wall motion is a significant factor in achieving high strain and piezoelectric coefficients in lead-free polycrystalline piezoelectrics.

  15. In situ measurement of electromigration-induced transient stress in Pb-free Sn-Cu solder joints by synchrotron radiation based X-ray polychromatic microdiffraction

    SciTech Connect (OSTI)

    Chen, Kai; Tamura, Nobumichi; Kunz, Martin; Tu, King-Ning; Lai, Yi-Shao

    2009-12-01T23:59:59.000Z

    Electromigration-induced hydrostatic elastic stress in Pb-free SnCu solder joints was studied by in situ synchrotron X-ray white beam microdiffraction. The elastic stresses in two different grains with similar crystallographic orientation, one located at the anode end and the other at the cathode end, were analyzed based on the elastic anisotropy of the Beta-Sn crystal structure. The stress in the grain at the cathode end remained constant except for temperature fluctuations, while the compressive stress in the grain at the anode end was built-up as a function of time during electromigration until a steady state was reached. The measured compressive stress gradient between the cathode and the anode is much larger than what is needed to initiate Sn whisker growth. The effective charge number of Beta-Sn derived from the electromigration data is in good agreement with the calculated value.

  16. In situ measurement of electromigration-induced transient stress in Pb-free Sn-Cu solder joints by synchrotron radiation based X-ray polychromatic microdiffraction

    SciTech Connect (OSTI)

    Chen, Kai; Tamura, Nobumichi; Kunz, Martin; Tu, King-Ning; Lai, Yi-Shao

    2009-05-15T23:59:59.000Z

    Electromigration-induced hydrostatic elastic stress in Pb-free SnCu solder joints was studied by in situ synchrotron X-ray white beam microdiffraction. The elastic stresses in two different grains with similar crystallographic orientation, one located at the anode end and the other at the cathode end, were analyzed based on the elastic anisotropy of the {beta}-Sn crystal structure. The stress in the grain at the cathode end remained constant except for temperature fluctuations, while the compressive stress in the grain at the anode end was built-up as a function of time during electromigration until a steady state was reached. The measured compressive stress gradient between the cathode and the anode is much larger than what is needed to initiate Sn whisker growth. The effective charge number of {beta}-Sn derived from the electromigration data is in good agreement with the calculated value.

  17. An analysis of the pull strength behaviors of fine-pitch, flip chip solder interconnections using a Au-Pt-Pd thick film conductor on Low-Temperature, Co-fired Ceramic (LTCC) substrates.

    SciTech Connect (OSTI)

    Uribe, Fernando R.; Kilgo, Alice C.; Grazier, John Mark; Vianco, Paul Thomas; Zender, Gary L.; Hlava, Paul Frank; Rejent, Jerome Andrew

    2008-09-01T23:59:59.000Z

    The assembly of the BDYE detector requires the attachment of sixteen silicon (Si) processor dice (eight on the top side; eight on the bottom side) onto a low-temperature, co-fired ceramic (LTCC) substrate using 63Sn-37Pb (wt.%, Sn-Pb) in a double-reflow soldering process (nitrogen). There are 132 solder joints per die. The bond pads were gold-platinum-palladium (71Au-26Pt-3Pd, wt.%) thick film layers fired onto the LTCC in a post-process sequence. The pull strength and failure modes provided the quality metrics for the Sn-Pb solder joints. Pull strengths were measured in both the as-fabricated condition and after exposure to thermal cycling (-55/125 C; 15 min hold times; 20 cycles). Extremely low pull strengths--referred to as the low pull strength phenomenon--were observed intermittently throughout the product build, resulting in added program costs, schedule delays, and a long-term reliability concern for the detector. There was no statistically significant correlation between the low pull strength phenomenon and (1) the LTCC 'sub-floor' lot; (2) grit blasting the LTCC surfaces prior to the post-process steps; (3) the post-process parameters; (4) the conductor pad height (thickness); (5) the dice soldering assembly sequence; or (5) the dice pull test sequence. Formation of an intermetallic compound (IMC)/LTCC interface caused by thick film consumption during either the soldering process or by solid-state IMC formation was not directly responsible for the low-strength phenomenon. Metallographic cross sections of solder joints from dice that exhibited the low pull strength behavior, revealed the presence of a reaction layer resulting from an interaction between Sn from the molten Sn-Pb and the glassy phase at the TKN/LTCC interface. The thick film porosity did not contribute, explicitly, to the occurrence of reaction layer. Rather, the process of printing the very thin conductor pads was too sensitive to minor thixotropic changes to ink, which resulted in inconsistent proportions of metal and glassy phase particles present during the subsequent firing process. The consequences were subtle, intermittent changes to the thick film microstructure that gave rise to the reaction layer and, thus, the low pull strength phenomenon. A mitigation strategy would be the use of physical vapor deposition (PVD) techniques to create thin film bond pads; this is multi-chip module, deposited (MCM-D) technology.

  18. THE LEAD AND COPPER RULE Anne Sandvig, HDR-EES

    E-Print Network [OSTI]

    Maynard, J. Barry

    THE LEAD AND COPPER RULE Anne Sandvig, HDR-EES 2008 Historical Background The 1986 Safe Drinking Water Act required the use of "lead-free" pipes, solders, pipe fittings or plumbing fixtures in the 1986 Amendment and were required to meet "voluntary standards." The term "lead-free" was defined

  19. Investigation of Gold Nanoparticle Inks for Low-Temperature Lead-Free Packaging Technology

    E-Print Network [OSTI]

    Bakhishev, Teymur; Subramanian, Vivek

    2009-01-01T23:59:59.000Z

    joint has excellent thermal stability and electromigration resistance, due to signi?cantly lower operating

  20. Ferroelectric and octahedral tilt twin disorder and the lead-free piezoelectric, sodium potassium niobate system

    SciTech Connect (OSTI)

    Schiemer, Jason [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Withers, Ray L., E-mail: withers@rsc.anu.edu.au [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Liu, Yun; Yi, Zhiguo [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)

    2012-11-15T23:59:59.000Z

    Using electron diffraction, trends in the local structural behaviour of the K{sub x}Na{sub 1-x}NbO{sub 3} (KNN x) 'solid solution' system are investigated and interpreted using an order/disorder based theoretical framework. At room temperature, electron diffraction shows a single plane of transverse polarised, diffuse intensity perpendicular to [0 1 0]{sub p} Low-Asterisk (p for parent sub-structure) across the entire phase diagram, indicative of ferroelectric disorder along the [0 1 0]{sub p} direction co-existing with long range ferroelectric order along the orthogonal [1 0 0]{sub p} and [0 0 1]{sub p} directions. An additional characteristic pattern of diffuse scattering is also observed, involving rods of diffuse intensity running along the [1 0 0]{sub p}* and [0 0 1]{sub p}* directions of the perovskite sub-structure and indicative of octahedral tilt disorder about the [1 0 0]{sub p} and [0 0 1]{sub p} axes co-existing with long range ordered octahedral tilting around the [0 1 0]{sub p} direction. A possible crystal chemical explanation for the existence of this latter octahedral tilt disorder is explored through bond valence sum calculations. The possible influence of both types of disorder on the previously refined, room temperature space group/s and average crystal structure/s is examined. - Graphical abstract: [-3,0.-1]p zone axis EDP of K{sub 0.46}Na{sub 0.54}NbO{sub 3} indexed according to both the relevant Pcm21 space groups (no subscripts) and the parent perovskite subcell (denoted by a subscript p). Highlights: Black-Right-Pointing-Pointer Characterises ferroelectric and octahedral tilt disorder in the KNN solid solution. Black-Right-Pointing-Pointer Discusses the possible driving forces for this disorder. Black-Right-Pointing-Pointer Discusses the implications of this disorder for physical properties. Black-Right-Pointing-Pointer Discusses the effects of this disorder on powder diffraction data.

  1. Development of lead-free copper alloy graphite castings. Annual report, January--December 1995

    SciTech Connect (OSTI)

    Rohatgi, P.K.

    1996-10-01T23:59:59.000Z

    The distribution of graphite particles in graphite containing copper alloy was further improved very significantly using several procedures and technological modifications. The developed techniques attacked the graphite distribution problem in two ways. Realizing that clustering of very fine (5um) graphite particles is one of the two major problems, a pretreatment process has been developed using aluminum powders to deagglomerate graphite particles. Along with this, a two-stage stirring technique was used to first incorporate and then to distribute uniformly the deagglomerated particles in the melt. During this year, based on these developments, several components were cast to evaluate the castability of Cu alloy-graphite melts. In addition, machinability tests were done to clearly established that addition of graphite particles improve the machinability of copper MMC alloys over and above that of monolithic copper alloys. The results show that the machining chip sizes and cutting forces of Cu alloys containing graphite particles are smaller than these of the corresponding monolithic Cu alloys. This clearly establishes that the presence of graphite particles in copper alloy improves the machinability in a fashion similar to lead additions to copper alloys. Centrifugal casting of shapes of different sizes appear to be a very attractive method for casting graphite containing copper alloys, since all the graphite particles (regardless of their distribution in the melt) are forced to segregate to the inner periphery of the castings where they impart a very desirable solid lubrication property for bushing and bearing use. A very large number of cylindrical elements of lead bearing copper alloys are now used for similar bearing bushing applications and the manufacturers of these type of bearings are under safety and health hazard pressure to remove lead. This year several parameters for centrifugal casting of copper graphite alloys have been established.

  2. Preparation and Characterization of Lead-free Piezoelectric Ceramics Qiang Chen1,a

    E-Print Network [OSTI]

    Volinsky, Alex A.

    -pressing technique as well as spark plasma sintering have been used to obtain high densities [2], but such processing a chenqiang30sf@163.com, b jxli65@ustb.edu.cn (corresponding author) Keywords: Sintering; Piezoelectric of sintering temperature on the structure, density and electrical properties of KNL-NTS ceramics were

  3. Epitaxial Stabilization of a Morphotropic Phase Boundary in Lead-Free Ferroelectric Thin Films

    E-Print Network [OSTI]

    Zeches, Robert James

    2011-01-01T23:59:59.000Z

    1376 (2005). D. L. Smith, Thin-Film Deposition PrinciplesMaterials Science of Thin Films, (Academic Press: San Diego,Laser Deposition of Thin Films, (John Wiley & Sons, Inc. :

  4. Epitaxial Stabilization of a Morphotropic Phase Boundary in Lead-Free Ferroelectric Thin Films

    E-Print Network [OSTI]

    Zeches, Robert James

    2011-01-01T23:59:59.000Z

    and electronic equipment (WEEE), Off. J. Eur. Union L37,c T c TDGL TEM UV V V V pp WEEE XRD YAO Z ZA ? ij ? P ? x ?Electronic Equipment (WEEE) directive and the Restriction of

  5. Journal of SMT October 2000 The move toward lead-free electronics has become a rapidly

    E-Print Network [OSTI]

    Bennett, Gisele

    's (EU) proposal for a Directive on Waste from Electrical and Electronic Equipment (WEEE of Electrical and Electronic Equipment (WEEE) and a Directive on the restriction of the use of certain hazardous

  6. Tailoring of unipolar strain in lead-free piezoelectrics using the ceramic/ceramic composite approach

    SciTech Connect (OSTI)

    Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, University of New South Wales, NSW 2052 (Australia); Groh, Claudia; Jo, Wook; Webber, Kyle G. [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Reinhard, Christina [Diamond Light Source, Beamline I12 JEEP, Didcot, Oxfordshire OX11 0DE (United Kingdom); Kimpton, Justin A. [The Australian Synchrotron, Clayton, Victoria 3168 (Australia)

    2014-03-28T23:59:59.000Z

    The electric-field-induced strain response mechanism in a polycrystalline ceramic/ceramic composite of relaxor and ferroelectric materials has been studied using in situ high-energy x-ray diffraction. The addition of ferroelectric phase material in the relaxor matrix has produced a system where a small volume fraction behaves independently of the bulk under an applied electric field. Inter- and intra-grain models of the strain mechanism in the composite material consistent with the diffraction data have been proposed. The results show that such ceramic/ceramic composite microstructure has the potential for tailoring properties of future piezoelectric materials over a wider range than is possible in uniform compositions.

  7. Pull strength evaluation of Sn-Pb solder joints made to Au-Pt-Pd and Au thick film structures on low-temperature co-fired ceramic -final report for the MC4652 crypto-coded switch (W80).

    SciTech Connect (OSTI)

    Uribe, Fernando; Vianco, Paul Thomas; Zender, Gary L.

    2006-06-01T23:59:59.000Z

    A study was performed that examined the microstructure and mechanical properties of 63Sn-37Pb (wt.%, Sn-Pb) solder joints made to thick film layers on low-temperature co-fired (LTCC) substrates. The thick film layers were combinations of the Dupont{trademark} 4596 (Au-Pt-Pd) conductor and Dupont{trademark} 5742 (Au) conductor, the latter having been deposited between the 4596 layer and LTCC substrate. Single (1x) and triple (3x) thicknesses of the 4596 layer were evaluated. Three footprint sizes were evaluated of the 5742 thick film. The solder joints exhibited excellent solderability of both the copper (Cu) lead and thick film surface. In all test sample configurations, the 5742 thick film prevented side wall cracking of the vias. The pull strengths were in the range of 3.4-4.0 lbs, which were only slightly lower than historical values for alumina (Al{sub 2}O{sub 3}) substrates. General (qualitative) observations: (a) The pull strength was maximized when the total number of thick film layers was between two and three. Fewer that two layers did not develop as strong of a bond at the thick film/LTCC interface; more than three layers and of increased footprint area, developed higher residual stresses at the thick film/LTCC interface and in the underlying LTCC material that weakened the joint. (b) Minimizing the area of the weaker 4596/LTCC interface (e.g., larger 5742 area) improved pull strength. Specific observations: (a) In the presence of vias and the need for the 3x 4596 thick film, the preferred 4596:5742 ratio was 1.0:0.5. (b) For those LTCC components that require the 3x 4596 layer, but do not have vias, it is preferred to refrain from using the 5742 layer. (c) In the absence of vias, the highest strength was realized with a 1x thick 5742 layer, a 1x thick 4596 layer, and a footprint ratio of 1.0:1.0.

  8. Solder Joint Materials By Design

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    - * Need to understand effect of higher temperatures on material microstructural evolution and property degradation 3 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY...

  9. Critical temperatures of superconducting solders

    E-Print Network [OSTI]

    Pavćo, Erica Medeiros

    2007-01-01T23:59:59.000Z

    Different magnetic strengths in MRIs produce different reactions and provide more insight into what being imaged. Being able to more quickly switch between two or more different magnet strengths would allow scientists in ...

  10. SafeVchat: Detecting Obscene Content and Misbehaving Users in Online Video Chat Services

    E-Print Network [OSTI]

    Liu, Xue

    , Shivakant Mishra1 1 University of Colorado at Boulder, 2 McGill University, 3 Ohio State University xingx involving computers; K.4.2 [Computers and Society]: Public Policy Issues--human safety, abuse and crime involving computers General Terms Security, Design, Experimentation, Algorithms 1. INTRODUCTION Online video

  11. MASTER OF SCIENCE MECHANICAL ENGINEERING

    E-Print Network [OSTI]

    and apparatus was developed and constructed based on a servo hydraulic test frame. The apparatus is capable, Lead Free Solder IMPROVED AEROTHERMODYNAMIC INSTRUMENTATION OF AN ALLISON T63-A-700 GAS TURBINE ENGINE for the gas generator turbine and exhaust state points were evaluated and average values were calculated

  12. Response of intergrown microstructure to an electric field and its consequences in the lead-free piezoelectric bismuth sodium titanate

    SciTech Connect (OSTI)

    Liu Yun, E-mail: yliu@rsc.anu.edu.au [Research School of Chemistry, Australian National University, ACT 0200 (Australia); Noren, Lasse [Research School of Chemistry, the Australian National University, ACT 0200 (Australia); Studer, Andrew J. [Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC NSW 2232 (Australia); Withers, Ray L.; Guo Yiping [Research School of Chemistry, Australian National University, ACT 0200 (Australia); Li Yongxiang [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Yang Hui [Research School of Chemistry, Australian National University, ACT 0200 (Australia); College of Life Science and Technology, Shaanxi University of Science and Technology, Xian 710021 (China); Wang Jian [Research School of Chemistry, Australian National University, ACT 0200 (Australia)

    2012-03-15T23:59:59.000Z

    We investigate the R3c average structure and micro-structure of the ceramic Bi{sub 0.5}Na{sub 0.5}TiO{sub 3} (BNT) in situ under applied electric fields using diffraction techniques. Electron diffraction implies the presence of significant octahedral tilt twin disorder, corresponding to the existence of a fine scale intergrown microstructural (IGMS) 'phase' within the R3c rhombohedral average structure matrix. A careful neutron refinement suggests not only that the off-centre displacements of the cations relative to the oxygens in the R3c regions increases systematically on application of an electric field but also that the phase fraction of the IGMS regions increases systematically. The latter change in phase fraction on application of the electric field enhances the polar displacement of the cations relative to the oxygen anions and affects the overall strain response. These IGMS regions form local polar nano regions that are not correlated with one another, resulting in polarisation relaxation and strain behaviour observed in BNT-containing materials. - Graphical abstract: The intergrown microstructure at very fine scales within the R3c rhombohedral phase matrix of BNT, originating from octahedral tilt twinning disorder, will increase with respect to an external field. Highlights: Black-Right-Pointing-Pointer The existence of an intergrown microstructural 'phase' within the average structure matrix. Black-Right-Pointing-Pointer This phase fraction of the intergrown microstructural regions changes. Black-Right-Pointing-Pointer Such regions form local polar nano regions that are not correlated with one another.

  13. Relationship between morphologies and orientations of Cu{sub 6}Sn{sub 5} grains in Sn3.0Ag0.5Cu solder joints on different Cu pads

    SciTech Connect (OSTI)

    Tian, Yanhong, E-mail: tianyh@hit.edu.cn; Zhang, Rui; Hang, Chunjin; Niu, Lina; Wang, Chunqing

    2014-02-15T23:59:59.000Z

    The morphologies and orientations of Cu{sub 6}Sn{sub 5} intermetallic compounds in the Sn3.0Ag0.5Cu solder joints both on polycrystalline and single crystal Cu pads under different peak reflow temperatures and times above liquids were investigated. The relationship between Cu{sub 6}Sn{sub 5} grain orientations and morphologies was clarified. At the interface of Sn3.0Ag0.5Cu/polycrystalline Cu pad, scalloped Cu{sub 6}Sn{sub 5} intermetallic compounds formed at 250 °C and roof shape Cu{sub 6}Sn{sub 5} formed at 300 °C. Both scalloped Cu{sub 6}Sn{sub 5} and roof shape Cu{sub 6}Sn{sub 5} had a preferred orientation of (0001) plane being parallel to polycrystalline Cu pad surface. Besides, the percentage of large angle grain boundaries increased as the peak reflow temperature rose. At the interface of Sn3.0Ag0.5Cu/(111) single crystal Cu pad, the Cu{sub 6}Sn{sub 5} intermetallic compounds were mainly scallop-type at 250 °C and were prism type at 300 °C. The prismatic Cu{sub 6}Sn{sub 5} grains grew along the three preferred directions with the inter-angles of 60° on (111) single crystal Cu pad while along two perpendicular directions on (100) single crystal Cu pad. The orientation relationship between Cu{sub 6}Sn{sub 5} grains and the single crystal Cu pads was investigated by electron backscatter diffraction technology. In addition, two types of hollowed Cu{sub 6}Sn{sub 5} intermetallic compounds were found inside the joints of polycrystalline Cu pads. The long hexagonal Cu{sub 6}Sn{sub 5} strips were observed in the joints reflowing at 250 °C while the hollowed Cu{sub 6}Sn{sub 5} strips with the ‘?’ shape cross-sections appeared at 300 °C, which was attributed to the different grain growth rates of different Cu{sub 6}Sn{sub 5} crystal faces. - Highlights: • The orientation of interfacial Cu{sub 6}Sn{sub 5} grains was obtained by EBSD technology. • Two types of hollowed Cu{sub 6}Sn{sub 5} strips were found at different temperatures. • The formation mechanism of hollowed Cu{sub 6}Sn{sub 5} was elaborated based on Bravais law. • The relationship between Cu{sub 6}Sn{sub 5} grain orientations and morphologies was clarified.

  14. Development of a hybrid microcircuit test vehicle for surface mount applications

    SciTech Connect (OSTI)

    Hernandez, C.L.; Hosking, F.M.; Vianco, P.T.

    1997-08-01T23:59:59.000Z

    The technology drivers of the electronics industry continue to be systems miniaturization and reliability, in addition to addressing a variety of important environmental concerns. Surface mount technology (SMT) has evolved in response to these issues. Prototype hybrid test vehicles have been developed at Sandia National Laboratories to evaluate three lead-free solders for Au-Pt-Pd thick film soldering. The alloys are based on the Sn-Ag, Sn-Ag-Bi and Sn-Ag-Bi-Au systems. Populated test vehicles with surface mount devices were designed and fabricated to evaluate actual solder joints. Pastes were screen printed on the test substrates and reflowed with the components in place. The test components consist of a variety of dummy chip capacitors and leadless ceramic chip carriers (LCC`s). The development of the reflow profiles will be discussed. Comprehensive defect analysis will also be presented.

  15. Electro-caloric effect in lead-free Sn doped BaTiO{sub 3} ceramics at room temperature and low applied fields

    SciTech Connect (OSTI)

    Upadhyay, Sanjay Kumar; Reddy, V. Raghavendra, E-mail: varimalla@yahoo.com, E-mail: vrreddy@csr.res.in; Bag, Pallab; Rawat, R. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India); Gupta, S. M. [Ceramic Laboratory, LMDDD, RRCAT, Indore 452013 (India); Gupta, Ajay [Amity Center for Spintronic Materials, Amity University, Noida 201303 (India)

    2014-09-15T23:59:59.000Z

    Structural, dielectric, ferroelectric (FE), {sup 119}Sn Mössbauer, and specific heat measurements of polycrystalline BaTi{sub 1–x}Sn{sub x}O{sub 3} (x?=?0% to 15%) ceramics are reported. Phase purity and homogeneous phase formation with Sn doping is confirmed from x-ray diffraction and {sup 119}Sn Mössbauer measurements. With Sn doping, the microstructure is found to change significantly. Better ferroelectric properties at room temperature, i.e., increased remnant polarization (38% more) and very low field switchability (225% less) are observed for x?=?5% sample as compared to other samples and the results are explained in terms of grain size effects. With Sn doping, merging of all the phase transitions into a single one is observed for x???10% and for x?=?5%, the tetragonal to orthorhombic transition temperature is found close to room temperature. As a consequence better electro-caloric effects are observed for x?=?5% sample and therefore is expected to satisfy the requirements for non-toxic, low energy (field) and room temperature based applications.

  16. Flat-to-Flat Solder Seal Andrey Elagin1

    E-Print Network [OSTI]

    To practice 8x8" seals we start from good parts with no scavenging Cu Scavenging Problem #12;11 Seal #1 A complete LAPPD glass tile except for an aluminum photo-cathode top seal by compression on a viton o Recipe for Ceramic Package Copper well is brazed into the ceramic body and filled with indium alloy (In

  17. Solder Joint Materials By Design | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo Ā»UsageSecretary ofSmallConfidential,2Cycle SelectionDepartment of11

  18. Solder Joints of Power Electronics | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo Ā»UsageSecretary ofSmallConfidential,2Cycle SelectionDepartment of11Joints

  19. Solder Joints of Power Electronics | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOriginEducationVideo Ā»UsageSecretary ofSmallConfidential,2Cycle SelectionDepartment of11Joints09

  20. Lab Breakthrough: Record-Setting Cavities | Department of Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-free Solder

  1. Lab Breakthrough: Supercomputing Power to Accelerate Fossil Energy Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-free Solder|

  2. Influence of La substitution on ferromagnetic properties of lead free Na{sub 0.5}Bi{sub 0.5}Ti{sub 0.988}Fe{sub 0.012}O{sub 3} multiferroic system

    SciTech Connect (OSTI)

    Parmar, Kusum, E-mail: prmrkusum@gamil.com; Sharma, Anshu, E-mail: prmrkusum@gamil.com; Negi, N. S. [Department of Physics, Himachal Pradesh University, Shimla -171005 (India); Kotnala, R. K. [National Physical Laboratory, New Delhi -110012 (India)

    2014-04-24T23:59:59.000Z

    To study the effect of La doping and processing temperature, (Na{sub 0.5}Bi{sub 0.5}){sub 1?x}La{sub x}Ti{sub 0.988}Fe{sub 0.012}O{sub 3} (NBLTF) samples have been prepared by sol-gel method by employing two approaches namely with and without mol% excess of Na and Bi. X-ray diffraction analysis confirms the formation of rhombohedral perovskite structure in these samples with minor impurity phases. However, the impurity phases of stochiometric NBLTF samples disappear on increasing the sintering temperature from 650°C to 850°C. On other hand, NBLTF samples prepared with mol% excess of Na and Bi have shown pure perovskite structure only at lower sintering temperature 650°C and also at low concentration of La ? 1%. Transmission electron microscope investigation shows nano crystalline formation for all NBLTF samples sintered at 850°C. The enhancement in room temperature ferromagnetism is observed in La doped NBTF samples prepared at 850°C by taking stoichiometric amount of Na and Bi during synthesis.

  3. Research into the microstructure and mechanical behavior of eutectic Bi-Sn and In-Sn

    SciTech Connect (OSTI)

    Goldstein, J.L.F.; Mei, Z.; Morris, J.W. Jr. [Lawrence Berkeley Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1993-08-01T23:59:59.000Z

    This manuscript reports on research into two low-melting, lead-free solder alloys, eutectic Bi-Sn and eutectic In-Sn. The microstructures were found to depend on both cooling rate and substrate, with the greatest variability in the In-Sn alloy. The nature of the intermetallic layer formed at the solder-substrate interface depends on both the solder and the substrate (Cu versus Ni). Also, the microstructure of the Bi-Sn can recrystallize during deformation, which is not the case with In-Sn. Data from creep and constant strain rate tests are given for slowly cooled samples. The creep behavior of In-Sn is constant with temperature, but the creep seems to be controlled by the In-rich phase in In-Sn on Cu and by the Sn-rich phase in In-Sn on Ni. Bi-Sn exhibits different creep behavior at temperatures above 40 {degrees}C than at 20 {degrees}C or lower. Stress-strain curves of Bi-Sn on Cu and In-Sn on Cu are similar, while In-Sn on Ni behaves differently. This is explained in terms of the deformation patterns in the alloys.

  4. Sharp Carbon-Nanotube Tips and Carbon-Nanotube Soldering Irons

    E-Print Network [OSTI]

    Daraio, Chiara

    ) and a carbon source (toluene) in a thermal chemical vapor deposition system as described in the experimental nanorods encapsulated inside the core of the tube are exposed to a continuous e-beam, centered in close

  5. Evaluation of optical solder for fiber-to-waveguide coupling in silicon photonics

    E-Print Network [OSTI]

    Tjioe, Fidelia

    2008-01-01T23:59:59.000Z

    Copper interconnects have shown its limit to meet the bandwidth demand even in the short reach applications due to its increase power consumption, RC delay, EMI, crosstalk and other effects which are aggravated as dimension ...

  6. Comparison of Accelerated Testing with Modeling to Predict Lifetime of CPV Solder Layers (Presentation)

    SciTech Connect (OSTI)

    Silverman, T. J.; Bosco, N.; Kurtz, S.

    2012-03-01T23:59:59.000Z

    Concentrating photovoltaic (CPV) cell assemblies can fail due to thermomechanical fatigue in the die-attach layer. In this presentation, we show the latest results from our computational model of thermomechanical fatigue. The model is used to estimate the relative lifetime of cell assemblies exposed to various temperature histories consistent with service and with accelerated testing. We also present early results from thermal cycling experiments designed to help validate the computational model.

  7. Influence of the Substrate on the Creep of SN Solder Joints

    E-Print Network [OSTI]

    Lee, K.-O.; Morris, J.W.; Hua, F.

    2010-01-01T23:59:59.000Z

    under nitrogen gas. The creep tests were done in a dead-loadhere. Details of the creep test procedure have been reportednor fractured during the creep tests done here, the chemical

  8. Photovoltaic effect of lead-free (Na{sub 0.82}K{sub 0.18}){sub 0.5}Bi{sub 4.5}Ti{sub 4}O{sub 15} ferroelectric thin film using Pt and indium tin oxide top electrodes

    SciTech Connect (OSTI)

    Seok Woo, Won; Sik Won, Sung; Won Ahn, Chang; Chae, Song A; Won Kim, Ill, E-mail: kimiw@mail.ulsan.ac.kr [Department of Physics and Energy Harvest-Storage Research Center (EHSRC), University of Ulsan, Ulsan 680-749 (Korea, Republic of); Ullah, Aman [Department of Physics, University of Science and Technology, Bannu, Khyber Pakhtunkhwa (Pakistan)

    2014-01-21T23:59:59.000Z

    We have grown a Bi-layer structure (Na{sub 0.82}K{sub 0.18}){sub 0.5}Bi{sub 4.5}Ti{sub 4}O{sub 15} (NKBiT) ferroelectric thin film on Pt(111)/TiO{sub 2}/SiO{sub 2}/Si(100) substrate by using the chemical solution deposition method and deposited two kinds of thin Pt and indium tin oxide (ITO) top electrodes. The photovoltaic behaviors of Pt/NKBiT/Pt and ITO/NKBit/Pt capacitors were investigated over the wavelength range of 300–500?nm. When NKBiT thin film is illuminated by the corresponding wavelength of the film's energy band gap (E{sub g}), a photocurrent is generated due to the Schottky barrier between electrode and film, and an internal electric field is originated by the depolarization field. The maximum photocurrent density and power conversion efficiency of the ITO/NKBiT/Pt capacitor in the poled-up state are obtained as 45.75?nA/cm{sup 2} and 0.035%, respectively, at 352?nm. The photocurrent density and power conversion efficiency of the ITO/NKBiT/Pt capacitor increased to 3.5 times higher than that of the Pt/NKBiT/Pt capacitor.

  9. Crystal structure analysis of lead free Ba{sub 1-x}La{sub x}[Ti{sub 0.5}(Fe{sub 0.5}Nb{sub 0.5}){sub 0.5}]{sub 1-x/4}O{sub 3} Ceramics

    SciTech Connect (OSTI)

    Patel, Piyush Kumar; Rani, Jyoti; Yadav, K. L. [Smart Materials Research Laboratory, Department of Physics Indian Institute of Technology, Roorkee-247667 (India)

    2012-06-05T23:59:59.000Z

    Single phase Ba{sub 1-x}La{sub x}[Ti{sub 0.5}(Fe{sub 0.5}Nb{sub 0.5}){sub 0.5}]{sub 1-x/4}O{sub 3} [referred as BT-LFN]; x=0, 0.02, 0.04 and 0.06 ceramics have been synthesized by solid - state reaction process and were characterized by X-ray diffraction technique. The microstructure of the ceramics was examined by field emission-scanning electron microscopy (FE-SEM).

  10. Direct evidence of correlations between relaxor behavior and polar nano-regions in relaxor ferroelectrics: A case study of lead-free piezoelectrics Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}-x%BaTiO{sub 3}

    SciTech Connect (OSTI)

    Ge, Wenwei, E-mail: wenweige@gmail.com; Luo, Chengtao; Devreugd, Christopher P.; Li, Jiefang; Viehland, D. [Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Zhang, Qinhui; Luo, Haosu [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China)] [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); Ren, Yang [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2013-12-09T23:59:59.000Z

    Diffuse scattering and relaxor behavior in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} (NBT) and NBT-5.6 at.?%BaTiO{sub 3} (NBT-5.6%BT) were investigated. X-ray diffraction revealed two types of diffuse scattering in NBT: (i) broad and (ii) asymmetric L-shaped. After modification with 5.6%BT, the broad diffuse scattering patterns became narrow, and the asymmetric L-shaped ones were replaced by symmetric ones. The symmetric diffuse scattering in NBT-5.6%BT disappeared with increasing dc electric field (E) for E???9.5?kV/cm where the frequency dispersion in the dielectric constant disappeared. These results demonstrate that the relaxor characteristics are directly correlated with the diffuse scattering and the presence polar nano-regions.

  11. Structure and temperature-dependent phase transitions of lead-free Bi[subscript 1/2]Na[subscript 1/2]TiO[subscript 3]?Bi[subscript 1/2]K[subscript 1/2]TiO[subscript 3]?K[subscript 0.5]Na[subscript 0.5]NbO[subscript 3] piezoceramics

    SciTech Connect (OSTI)

    Anton, Eva-Maria; Schmitt, Ljubomira Ana; Hinterstein, Manuel; Trodahl, Joe; Kowalski, Ben; Jo, Wook; Kleebe, Hans-Joachim; Rödel, Jürgen; Jones, Jacob L. (TU Darmstadt) [TU Darmstadt; (VUW); (Florida)

    2014-05-28T23:59:59.000Z

    Structure and phase transitions of (1-y)((1-x)Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-xBi{sub 1/2}K{sub 1/2}TiO{sub 3})-yK{sub 0.5}Na{sub 0.5}NbO{sub 3} (x; y) piezoceramics (0.1 {le} x {le} 0.4; 0 {le} y {le} 0.05) were investigated by transmission electron microscopy, neutron diffraction, temperature-dependent x-ray diffraction, and Raman spectroscopy. The local crystallographic structure at room temperature (RT) does not change by adding K{sub 0.5}Na{sub 0.5}NbO{sub 3} to Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-xBi{sub 1/2}K{sub 1/2}TiO{sub 3} for x = 0.2 and 0.4. The average crystal structure and microstructure on the other hand develop from mainly long-range polar order with ferroelectric domains to short-range order with polar nanoregions displaying a more pronounced relaxor character. The (0.1; 0) and (0.1; 0.02) compositions exhibit monoclinic Cc space group symmetry, which transform into Cc + P4bm at 185 and 130 C, respectively. This high temperature phase is stable at RT for the morphotropic phase boundary compositions of (0.1; 0.05) and all compositions with x = 0.2. For the compositions of (0.1; 0) and (0.1; 0.02), local structural changes on heating are evidenced by Raman; for all other compositions, changes in the long-range average crystal structure were observed.

  12. Rework of CSP: the effect on surface intermetallic Electronics Manufacturing Research Group, School of Aeronautical, Mechanical

    E-Print Network [OSTI]

    Ekere, Ndy

    solder joint formed on a copper pad with electroless nickel/immersion gold coatings consists solderable layer (nickel); 3 a single intermetallic layer (Ni3Sn4); 4 bulk solder region (Sn-Pb). This paper

  13. Reflow profile study of the Sn-Ag-Cu solder School of Engineering, University of Greenwich, Kent, UK

    E-Print Network [OSTI]

    Ekere, Ndy

    Equipment (WEEE) and Restriction of Hazardous Substances (RoHS) Directives is scheduled to eliminate

  14. Contractual Anonymity Edward J. Schwartz David Brumley

    E-Print Network [OSTI]

    will remain anonymous and indistinguishable as long as they abide by a pre-negotiated terms of service contract, 2) network providers can identify users who misbehave by violating the same contract, and 3

  15. USSR report: Materials science and metallurgy, [November 7, 1986

    SciTech Connect (OSTI)

    NONE

    1986-11-07T23:59:59.000Z

    Partial contents include: Analysis and Testing, Coatings, Corrosion, Ferrous Metals, Nonferrous Metals and Alloys ;Brazes and Solders, Nonmetallic Materials, Preparation, Treatments, Welding, Brazing and Soldering.

  16. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 10, NO. 1, MARCH 2001 107 Fabrication of Metallic Heat Exchangers Using

    E-Print Network [OSTI]

    Prentiss, Mara

    ­ silicon etching, titanium diffusion bonding, tin/lead soldering, and micromachining of copper ­ commonly

  17. The Applications of Synchrotron Radiation X-rays 3D Imaging Techniques to The Study of Electromigration Failure in Flip-Chip Solder Joints

    E-Print Network [OSTI]

    Tian, Tian

    2012-01-01T23:59:59.000Z

    is called the electron wind force. The direct force and thewhile the electron wind force is in the same direction asinduced by electron wind force, is one of the most serious

  18. Surface mounted PCB cleaning process improvement and Its impact on manufacturing system performance

    E-Print Network [OSTI]

    Rajendran, Nikith

    2011-01-01T23:59:59.000Z

    In the surface mount technology (SMT) assembly line, the printed circuit boards (PCB) are washed to remove the solder flux that was used while soldering to prevent oxidation. However the current cleaning method is highly ...

  19. Cleaning process development and optimization in the surface mount assembly line of power modules

    E-Print Network [OSTI]

    Mukherjee, Ishan

    2011-01-01T23:59:59.000Z

    The cleaning process in the surface mount assembly line of power modules had been found to insufficiently remove solder flux residue from printed circuit board (PCB) assemblies after the process of reflow soldering. This ...

  20. A computer music instrumentarium

    E-Print Network [OSTI]

    Oliver La Rosa, Jaime Eduardo

    2011-01-01T23:59:59.000Z

    Chapter 6. COMPUTERS: To Solder or Not toMusic Models : A Computer Music Instrumentarium . . . . .Interactive Computer Systems . . . . . . . . . . . . . . 101

  1. Closeout Report for theCloseout Report for the National Spherical Torus

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    in recommendations to improve techniques for soldering cooling tubes in the TF conductor to prevent flux from techniques (e.

  2. Microsoft PowerPoint - Stephen Barnes DOE.pptx [Read-Only

    Office of Environmental Management (EM)

    Machinery Mechanics * Maintenance Workers, Machinery * First-Line Supervisors of Production and Operating Workers * Welders, Cutters, Solderers, and Brazers * Petroleum...

  3. Manufacturing industry challenges and responses to EU, California, and other product-targeted environmental regulations

    E-Print Network [OSTI]

    Kirschner, Michael

    2008-01-01T23:59:59.000Z

    electronic components together because its material, thermal, and – as a part of the solder system between parts – reliability

  4. TM-mode coupling to a Josephson junction S. J. Lewandowski

    E-Print Network [OSTI]

    Boyer, Edmond

    of the junction electrodes. to the j unction was provided by two leads immersed in superconducting solder, which

  5. Chapter 5: Ball Grid Array (BGA) 5.1 Development of the Models

    E-Print Network [OSTI]

    Berlin,Technische UniversitƤt

    of these is left to a future sub-model of the solder joints. The top and bottom layers of each ball are 25 micron #12;Thirdly, the unit cell is replicated to form a block of 34 solder balls, which represents one Results The predicted lifetime of each model is based on the strain development within the solder joints

  6. On Data-centric Misbehavior Detection in VANETs Sushmita Ruj, Marcos A. Cavenaghi, Zhen Huang, Amiya Nayak, and Ivan Stojmenovic

    E-Print Network [OSTI]

    Stojmenovic, Ivan

    and propose algorithms which detect false alert messages and misbehaving nodes by observing their actions). Malicious nodes might have criminal motives to cause accidents and may also attempt to gather sensitive together. Authentication techniques rely on signatures, a message is signed with a private key to verify

  7. Multiwire conductor having greatly increased interwire resistance and method for making same

    DOE Patents [OSTI]

    Luhman, T.; Suenaga, M.

    1982-03-15T23:59:59.000Z

    An improved multiwire conductor of the type which is mechanically stabilized by a tin based solder filler is described. A solder filled conductor is heated to a temperature above its melting point for a period long enough to allow a substantial amount of copper to be dissolved from the wires comprising the conductor. The copper forms the brittle intermetallic compound Cu/sub 5/Sn/sub 6/ with tin in the solder. After cooling the conductor is flexed causing a random cracking of the solder, and thereby increasing the interwire resistance of the conductor. The subject invention is particularly adapted for use with braided, ribbon-type solder filled superconductors.

  8. The four pins of the retention module can easily be soldered after the board has been loaded. This is an improvement over attempting to hand load fine-pitch connectors.

    E-Print Network [OSTI]

    LaMeres, Brock J.

    to place-and-route signals to a non-intrusive footprint com- prised of landing pads and small retention, as well as electri- cally intrusive to the integrity of the signals. With the advent of connectorless and less intrusive for high-speed applications. Mechanical advantages Connectorless probing offers a number

  9. Thermal Effects on PCB Laminate Material Dielectric Constant and Dissipation Scott Hinaga

    E-Print Network [OSTI]

    Koledintseva, Marina Y.

    will be exposed to a higher temperature (250-260Ā°C), if Hot Air Solder Level (HASL) surface finish is applied

  10. In: O'Brien R L (ed.) Welding Handbook-Volume 3: Materials and Applications, 8th Edn. American Welding

    E-Print Network [OSTI]

    Eagar, Thomas W.

    (fastening, adhesive bonding, soldering, brazing, arc welding, diffusion bonding, resistance welding, etc, such as diffusion bonding, come very close to this ideal; .·. ·.'· .. . . . : ' : \\. ·:-';..·. .: ... Joining

  11. Cisco Systems Funds "Whisker" Growth Research at the ALS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Print Friday, 09 November 2012 10:06 Lead-free components have been increasingly used in electronics manufacturing since the European Union passed its 2003 Restriction of...

  12. autoclave cure process: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ( ); if it has very faint text (the word "autoclaved"), it most likely is a lead-free alternative. ADDITIONAL Ford, James 13 Information provided by the University of...

  13. California Households’ Willingness to Pay for “Green” Electronics

    E-Print Network [OSTI]

    Saphores, Jean-Daniel M; Nixon, Hilary; Ogunseitan, Oladele; Shapiro, Andrew A

    2007-01-01T23:59:59.000Z

    Adults Towards Consumer Electronics Chicago, IL. Montgomery,2005. Adopting lead-free electronics: Knowledge gaps andworth taking Consumer Electronics Association, Arlington,

  14. Method for optical and mechanically coupling optical fibers

    DOE Patents [OSTI]

    Toeppen, John S. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    A method and apparatus for splicing optical fibers. A fluorescing solder glass frit having a melting point lower than the melting point of first and second optical fibers is prepared. The solder glass frit is then attached to the end of the first optical fiber and/or the end of the second optical fiber. The ends of the optical fibers are aligned and placed in close proximity to each other. The solder glass frit is then heated to a temperature which is lower than the melting temperature of the first and second optical fibers, but which is high enough to melt the solder glass frit. A force is applied to the first and second optical fibers pushing the ends of the fibers towards each other. As the solder glass flit becomes molten, the layer of molten solder glass is compressed into a thin layer between the first and second optical fibers. The thin compressed layer of molten solder glass is allowed to cool such that the first and second optical fibers are bonded to each other by the hardened layer of solder glass.

  15. GPEC 2005 Paper Abstract #48: Title: Meeting the Plastics Challenges for Toxic Materials

    E-Print Network [OSTI]

    Short, Daniel

    and may be optimized for a wide variety of materials applications including plastics, alloys, soil, paints retardants to replace Br-based ones and solder alloys to replace the lead-based solders commonly used the directives; however, the U.S. Joint Group on Pollution Prevention (JG-PP) which includes major aerospace

  16. Phase-field Models for Solidification and Solid/Liquid Interactions 

    E-Print Network [OSTI]

    Park, Min Soo

    2011-02-22T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 113 B. Intermetallic compound growth during soldering reac- tion for Cu6Sn5 . . . . . . . . . . . . . . . . . . . . . . . . 115 1. Phase ?eld and di?usion equations... . . . . . . . . . . . 115 2. Evaluation of model parameters . . . . . . . . . . . . 118 3. Numerical implementation . . . . . . . . . . . . . . . 119 4. Results and discussions . . . . . . . . . . . . . . . . . 122 C. Intermetallic compound growth during soldering reac...

  17. AUSTRALIAN NATIONAL UNIVERSITY DEPARTMENT OF NUCLEAR PHYSICS

    E-Print Network [OSTI]

    Chen, Ying

    , but was found to be a broken solder joint on the turbo 24volt relay circuit. The temperature sensor on the platform by Alistair Muirhead, found that one of the wires that provide 24v to the turbo pump relays was broken from its spark protection feed through terminal on the side of the GP3 box. The soldered

  18. ANALYSIS OF CATASTROPHIC FIELD FAILURES DUE TO CONDUCTIVE ANODIC FILAMENT (CAF) FORMATION

    E-Print Network [OSTI]

    Bennett, Gisele

    in the use environment. CAF formation is enhanced by the use of certain hot air solder leveling (HASL) fluids failures were related to boards produced in a manufacturing process, which included HASL. One CAF failure-ray spectroscopy (EDS) and ion chromatography (IC) will be used to relate the hot air solder leveling (HASL) fluid

  19. 12/31/11 Analog to Digital Converter Test Report Page 1 of 5 Created 3/3/08 by Nicole Rodia Modified 5/18/08 11:01 PM by Nicole Rodia

    E-Print Network [OSTI]

    Ruina, Andy L.

    as well as on the Ko Brain board under a variety of conditions. Using the Ko Brain board, tests were wire Soldering iron 1.5 V battery Battery holder 10 k, 100 k resistors 22 nF capacitor Multimeter wrap wire to keep wires short to reduce electromagnetic interference. Soldered connections to battery

  20. This is an author-deposited version published in: http://oatao.univ-toulouse.fr/ Eprints ID: 10622

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    diffusion bonding (SSDB) are now cited as substitutes for solders reflow process. Particularly, solid state diffusion bonding [3,4] is used for silver and gold based alloys such as Au-Sn and Au-Ge solders of voids or weak intermetallic compounds in the interfaces. There are many ways to en- sure good bonding

  1. A Smart Machine Vision System for PCB Inspection Tie Qi Chen1

    E-Print Network [OSTI]

    Lu, Yi

    visual inspection of PCB boards[1,2,3]. The manufacturing of PCB circuits uses the SMT (Surface Mount Technology). The SMT circuit assembly consists of three major processes, screen printing solder paste, and ·Post-reflow inspection. Placing a proper amount of solder paste on a pad is the key to prevent unwanted

  2. NCMS PWB Surface Finishes Team project summary

    SciTech Connect (OSTI)

    Kokas, J.; DeSantis, C. [United Technologies Corp., Farmington, CT (United States). Hamilton Standard Div.; Wenger, G. [AT and T, New York, NY (United States)] [and others

    1996-04-01T23:59:59.000Z

    The NCMS PWB Surface Finishes Consortium is just about at the end of the five year program. Dozens of projects related to surface finishes and PWB solder-ability were performed by the team throughout the program, and many of them are listed in this paper. They are listed with a cross reference to where and when a technical paper was presented describing the results of the research. However, due to time and space constraints, this paper can summarize the details of only three of the major research projects accomplished by the team. The first project described is an ``Evaluation of PWB Surface Finishes.`` It describes the solderability, reliability, and wire bondability of numerous surface finishes. The second project outlined is an ``Evaluation of PWB Solderability Test Methods.`` The third project outlined is the ``Development and Evaluation of Organic Solderability Preservatives.``

  3. Methods of making metallic glass foil laminate composites

    DOE Patents [OSTI]

    Vianco, P.T.; Fisher, R.W.; Hosking, F.M.; Zanner, F.J.

    1996-08-20T23:59:59.000Z

    A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone. 6 figs.

  4. Methods of making metallic glass foil laminate composites

    DOE Patents [OSTI]

    Vianco, Paul T. (Albuquerque, NM); Fisher, Robert W. (Albuquerque, NM); Hosking, Floyd M. (Albuquerque, NM); Zanner, Frank J. (Sandia Park, NM)

    1996-01-01T23:59:59.000Z

    A process for the fabrication of a rapidly solidified foil laminate composite. An amorphous metallic glass foil is flux treated and coated with solder. Before solidification of the solder the foil is collected on a take-up spool which forms the composite into a solid annular configuration. The resulting composite exhibits high strength, resiliency and favorable magnetic and electrical properties associated with amorphous materials. The composite also exhibits bonding strength between the foil layers which significantly exceeds the bulk strength of the solder alone.

  5. Improved generator and detector of millimeter waves for use in microwave spectroscopy

    E-Print Network [OSTI]

    Tolberg, Wesley Edward

    1958-01-01T23:59:59.000Z

    of the corrosion problem were necessary. Tungsten wire was nickel plated and soldered in place. A pair of probes having solidered connections between tungsten and brass was made and tested. Not only were they appreciably more efficient in energy output.... It was necessary to solder small pieces of the slabs to the crystal mounting block and to grind them to the proper size for use as detector and generator crystals. Silicon semiconductor must first be nickel plated before it can be soldered. The nickel plating...

  6. Hazardous material minimization for radar assembly. Final report

    SciTech Connect (OSTI)

    Biggs, P.M.

    1997-03-01T23:59:59.000Z

    The Clean Air Act Amendment, enacted in November 1990, empowered the Environmental Protection Agency (EPA) to completely eliminate the production and usage of chlorofluorocarbons (CFCs) by January 2000. A reduction schedule for methyl chloroform beginning in 1993 with complete elimination by January 2002 was also mandated. In order to meet the mandates, the processes, equipment, and materials used to solder and clean electronic assemblies were investigated. A vapor-containing cleaning system was developed. The system can be used with trichloroethylene or d-Limonene. The solvent can be collected for recycling if desired. Fluxless and no-clean soldering were investigated, and the variables for a laser soldering process were identified.

  7. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 14, NO. 1, FEBRUARY 2005 153 A New Methodology to Investigate Fracture

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    of Multiple-Joint Solder Self-Assembled Microelectromechanical Systems (MEMS) Paul E. Kladitis, Air Force, USA Abstract Surface-micromachined microelectromechanical systems (MEMS) are two dimensional, Tolerance Analysis Introduction Microelectromechanical systems (MEMS) fabri- cation can be generally

  8. CUTTING -WELDING -HOT WORKS REQUIRED NOTIFICATION TO CUFD

    E-Print Network [OSTI]

    Stuart, Steven J.

    CUTTING - WELDING - HOT WORKS REQUIRED NOTIFICATION TO CUFD Instructions: Fill out this form in its Time for work: Description of Work: Brazing Roofing Sweating WeldingSolderingCutting Other

  9. eCopy, Inc.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    crosshead speed was 0.05 inmin. In order to simulate the following fusion welding and brazing or soldering processes, the tensile samples were heated in a vacuum furnace under...

  10. HRSG/SR Revised 07/01/08 Page 1 of 2 HAZARD ASSESSMENT SURVEY & ANALYSIS

    E-Print Network [OSTI]

    Eirinaki, Magdalini

    /face shield Impact goggles UV light-welding, cutting, torch brazing, or soldering Welding goggles Welding/Glare/High Intensity lights Laser operations Shaded safety glasses Laser spectacles or goggles Eyes and Face Other

  11. JOB SAFETY ASSESSMENT ENVIRONMENTAL

    E-Print Network [OSTI]

    Hartman, Chris

    Radiation (sun) Radio Frequency/Microwave Radiation Lasers Ionizing Radiation Airborne Contaminants (fumes/Herbicide Excavation/Trenching/Shoring Asbestos Awareness/Abatement Welding/Cutting/Brazing/Soldering Powder Actuated

  12. Specifications are subject to change without notice. 29 For technical assistance call the Trimmer

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    Stops..................Wiper idles Terminals ........................Solderable pins Weight diagram, date code, manufacturer's model number and style Wiper ..............................Set at CW Adjustment Tool ..............................H-90 1 3 CW CLOCKWISE CCW 2 WIPER 1.52 (.060) 3 2 1 BOTTOM VIEW

  13. DOE Publishes Report on Accelerated Life Testing of SSL Luminaires...

    Broader source: Energy.gov (indexed) [DOE]

    of which were attributed to solder-joint fatigue, and the other two to board-level corrosion. The findings reinforce the belief that LEDs in lighting systems are highly...

  14. Abstract--Comparing to the most common reliability tests this work presents a new approach of accelerated

    E-Print Network [OSTI]

    Boyer, Edmond

    environment is particularly severe for electronic components (IGBT, capacitors, solder joints, etc power electronics systems reliability by taking into account their environment. More electricAbstract-- Comparing to the most common reliability tests this work presents a new approach

  15. automated thermal cycling: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    IGBT failure mode, due to thermal fatigue, is the solder cracks between the copper base plate and the Direct Boyer, Edmond 28 The effects of controlled thermal cycling on...

  16. Non-contact biopotential sensing

    E-Print Network [OSTI]

    Chi, Yu Mike

    2011-01-01T23:59:59.000Z

    hot air surface leveled (HASL) PCB finish, silver cloth,electrodes for BSNs. The HASL PCB finish and solder mask areAg/AgCl electrode, cotton, HASL, latex, silver cloth, and

  17. IEEE TRANSACTIONS ON ADVANCED PACKAGING, VOL. 23, NO. 2, MAY 2000 285 A Comparison of Hourly Versus Daily

    E-Print Network [OSTI]

    Bennett, Gisele

    leveling (HASL) fluids. This work evaluates two electrical reliability-testing methods. One method recorded, hot-air solder leveling (HASL) fluids, surface insulation resistance (SIR), water-soluble flux. I

  18. XINGHUI LIU 1111 Engineering Drive, UCB 427, Boulder, Colorado 80309-0427

    E-Print Network [OSTI]

    Bunch, Scott

    : machining, mold & die, 3D printing, PCB, soldering and etc. (~2 years hands-on experience) Programming atomization system to produce an ultra-fine metal powers. ---- NSF in China 3D printing with laser sintering

  19. The Feasibility of Casting Sculpture in Kirksite

    E-Print Network [OSTI]

    Fox, Lewis Howard

    1968-01-01T23:59:59.000Z

    of equal parts of ammonium chloride and lithium n chloride. When soldering, use an 82.5 percent cadmium or 17.5 percent zinc solder with no flux.3 •^ Metals Handbook. op. cit. , I, p. 1158. ^J. F. Lancaster. The Metallurgy of Welding, Brazing... Silver Chromium Gold These platings are most commonly applied for decorative purposes, but they also improve resistance to corrosion and abrasion. All plated coatings are somewhat porous; and, when moisture penetrates through the pores, some...

  20. Spectral characteristics of a laser emitter designed for pumping and detecting a reference quantum transition of a caesium frequency standard

    SciTech Connect (OSTI)

    Ivanov, A V; Kurnosov, V D; Kurnosov, K V; Romantsevich, V I; Chernov, Roman V; Marmalyuk, Aleksandr A; Volkov, N A; Zholnerov, V S

    2011-08-31T23:59:59.000Z

    Experimental and calculated spectral characteristics of a diode laser with a Bragg grating soldered on a thermoelectric cooler are presented. A model of the laser is developed, which takes into account the pressure arising after soldering the Bragg grating on the thermoelectric cooler, as well as temperature and dispersion. Theoretical and experimental spectral characteristics of the laser are compared and their satisfactory agreement is shown. (control of radiation parameters)

  1. Ceramic-polymer nanocomposites with increased dielectric permittivity and low dielectric loss

    SciTech Connect (OSTI)

    Bhardwaj, Sumit, E-mail: sumit.bhardwaj4@gmail.com; Paul, Joginder, E-mail: sumit.bhardwaj4@gmail.com [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Raina, K. K. [School of Physics and Materials Science, Thapar University, Patiala -147 004 (India); Thakur, N. S. [Centre for Energy and Environment, National Institute of Technology, Hamirpur -177005 (India); Kumar, Ravi [Centre for Materials Science and Engineering, National Institute of Technology, Hamirpur -177 005 (India); Beant College of Engineering and Technology, Gurdaspur -143521 (India)

    2014-04-24T23:59:59.000Z

    The use of lead free materials in device fabrication is very essential from environmental point of view. We have synthesized the lead free ferroelectric polymer nanocomposite films with increased dielectric properties. Lead free bismuth titanate has been used as active ceramic nanofillers having crystallite size 24nm and PVDF as the polymer matrix. Ferroelectric ?-phase of the polymer composite films was confirmed by X-ray diffraction pattern. Mapping data confirms the homogeneous dispersion of ceramic particles into the polymer matrix. Frequency dependent dielectric constant increases up to 43.4 at 100Hz, whereas dielectric loss decreases with 7 wt% bismuth titanate loading. This high dielectric constant lead free ferroelectric polymer films can be used for energy density applications.

  2. Current Lead Design for the Accelerator Project for Upgrade of LHC

    SciTech Connect (OSTI)

    Brandt, Jeffrey S.; Cheban, Sergey; Feher, Sandor; Kaducak, Marc; Nobrega, Fred; Peterson, Tom

    2010-01-01T23:59:59.000Z

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. In collaboration with Brookhaven National Laboratory, Fermilab is developing sub-systems for an upgrade of the LHC final focus magnet systems. A concept of main and auxiliary helium flow was developed that allows the superconductor to remain cold while the lead body warms up to prevent upper section frosting. The auxiliary flow will subsequently cool the thermal shields of the feed box and the transmission line cryostats. A thermal analysis of the current lead central heat exchange section was performed using analytic and FEA techniques. A method of remote soldering was developed that allows the current leads to be field replaceable. The remote solder joint was designed to be made without flux or additional solder, and able to be remade up to ten full cycles. A method of upper section attachment was developed that allows high pressure sealing of the helium volume. Test fixtures for both remote soldering and upper section attachment for the 13 kA lead were produced. The cooling concept, thermal analyses, and test results from both remote soldering and upper section attachment fixtures are presented.

  3. Modeling tin whisker growth.

    SciTech Connect (OSTI)

    Weinberger, Christopher Robert

    2013-08-01T23:59:59.000Z

    Tin, lead, and lead-tin solders are the most commonly used solders due to their low melting temperatures. However, due to the toxicity problems, lead must now be removed from solder materials. This has lead to the re-emergence of the issue of tin whisker growth. Tin whiskers are a microelectronic packaging issue because they can lead to shorts if they grow to sufficient length. However, the cause of tin whisker growth is still not well understood and there is lack of robust methods to determine when and if whiskering will be a problem. This report summarizes some of the leading theories on whisker growth and attempts to provide some ideas towards establishing the role microstructure plays in whisker growth.

  4. Process for electrically interconnecting electrodes

    DOE Patents [OSTI]

    Carey, Paul G. (Mountain View, CA); Thompson, Jesse B. (Brentwood, CA); Colella, Nicolas J. (Livermore, CA); Williams, Kenneth A. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    Electrical interconnects for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb--Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb--Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value.

  5. Automated solar cell assembly teamed process research. Semiannual subcontract report, December 6, 1993--June 30, 1994

    SciTech Connect (OSTI)

    Nowlan, M. [Spire Corp., Bedford, MA (United States)

    1995-01-01T23:59:59.000Z

    This is the second Semiannual Technical Progress Report for the program titled `Automated Solar Cell Assembly Teamed Process Research` funded under National Renewable Energy Laboratory (NREL) subcontract No. ZAG-3-11219-01. This report describes the work done on Phase II of the program in the period from December 6, 1993 to June 30, 1994. Spire`s objective in this program is to develop high throughput (5 MW/yr) automated processes for interconnecting thin (200 {mu}m) silicon solar cells. High yield will be achieved with these fragile cells through the development of low mechanical stress and low thermal stress processes. For example, a machine vision system is being developed for cell alignment without mechanically contacting the cell edges, while a new soldering process is being developed to solder metal interconnect ribbons simultaneously to a cells` front and back contacts, eliminating one of the two heating steps normally used for soldering each cell.

  6. Solar cell array interconnects

    DOE Patents [OSTI]

    Carey, P.G.; Thompson, J.B.; Colella, N.J.; Williams, K.A.

    1995-11-14T23:59:59.000Z

    Electrical interconnects are disclosed for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value. 4 figs.

  7. Method of assembling an electric power

    DOE Patents [OSTI]

    Rinehart, Lawrence E. (Lake Oswego, OR); Romero, Guillermo L. (Phoenix, AZ)

    2007-05-03T23:59:59.000Z

    A method of assembling and providing an electric power apparatus. The method uses a heat resistant housing having a structure adapted to accommodate and retain a power circuit card and also including a bracket adapted to accommodate and constrain a rigid conductive member. A power circuit card having an electrical terminal is placed into the housing and a rigid conductive member into the bracket. The rigid conductive member is flow soldered to the electrical terminal, thereby exposing the heat resistant housing to heat and creating a solder bond. Finally, the rigid conductive member is affirmatively connected to the housing. The bracket constrains the rigid conductive member so that the act of affirmatively connecting does not weaken the solder bond.

  8. Solar cell array interconnects

    DOE Patents [OSTI]

    Carey, Paul G. (Mountain View, CA); Thompson, Jesse B. (Brentwood, CA); Colella, Nicolas J. (Livermore, CA); Williams, Kenneth A. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    Electrical interconnects for solar cells or other electronic components using a silver-silicone paste or a lead-tin (Pb-Sn) no-clean fluxless solder cream, whereby the high breakage of thin (<6 mil thick) solar cells using conventional solder interconnect is eliminated. The interconnects of this invention employs copper strips which are secured to the solar cells by a silver-silicone conductive paste which can be used at room temperature, or by a Pb-Sn solder cream which eliminates undesired residue on the active surfaces of the solar cells. Electrical testing using the interconnects of this invention has shown that no degradation of the interconnects developed under high current testing, while providing a very low contact resistance value.

  9. Technique for Measuring Hybrid Electronic Component Reliability

    SciTech Connect (OSTI)

    Green, C.C.; Hernandez, C.L.; Hosking, F.M.; Robinson, D.; Rutherford, B.; Uribe, F.

    1999-01-01T23:59:59.000Z

    Materials compatibility studies of aged, engineered materials and hardware are critical to understanding and predicting component reliability, particularly for systems with extended stockpile life requirements. Nondestructive testing capabilities for component reliability would significantly enhance lifetime predictions. For example, if the detection of crack propagation through a solder joint can be demonstrated, this technique could be used to develop baseline information to statistically determine solder joint lifelengths. This report will investigate high frequency signal response techniques for nondestructively evaluating the electrical behavior of thick film hybrid transmission lines.

  10. Studies of the Scott effect using large magnetic fields

    E-Print Network [OSTI]

    Ball, Raiford Mill

    1971-01-01T23:59:59.000Z

    of the ccils ?ere wound in pairs on copper pipe coil-forms, which are 1. 651 cm wide and have an inside radius of 3. 805 cm. Fach form has six 0. 3. 75 cm slots equally spaced around the circumference. The remaining coils were wound on an aluminum knockout... and soldered together at the inside turn. Those wound on the copper forms were soldered to the form itself. Two coils form a single pancake with a nominal room tempera- ture resistance of 1. 56 ohms. The total resistance of the magnet at liquid nitrogen...

  11. Determination of rate constants for the reaction between methyldiethanolamine and carbon dioxide 

    E-Print Network [OSTI]

    Brabson, Charles Meade

    1985-01-01T23:59:59.000Z

    a Nz atmosphere in the drums and also to agitate the amine solution. The feed pump was a Teel model 1P988 rated at 3 gpm (11. 5 lit/min) at 500 psia (35 atm). It was constructed of cast iron. The QS Sample Port QT Thermocouple 6 Pressure Gauge..., no welding or soldering was required which may have damaged the disc. A stainless steel plate was then welded onto the bottom of the reactor. This created a boxed enclosure. The feed gas entered this enclosure through 1/4" stainless steel tubing soldered...

  12. Measurement of neutron spectrum in an AGN-201 reactor using a semiconductor neutron spectrometer

    E-Print Network [OSTI]

    Stephenson, S. E

    1961-01-01T23:59:59.000Z

    National Labora- tory (15). Wafers of 2700 ohm-cm resistivity, n-type silicon were hand lapped in Grit No. 240 and 600 silicon carbide powder. The wafers were then nickel plated in an electroless nickel plating bath (17). A No. 2 round head brass screw..., with the head filed flat, was soldered to the nickel film with ordinary 5-core 40/60 solder. The nickel on the other five diode faces was then lapped off with No. 600 silicon carbide powder. The remaining nickel plating was masked by apiezon wax dissolved...

  13. Development of Readout Interconnections for the Si-W Calorimeter of SiD

    SciTech Connect (OSTI)

    Woods, M.; Fields, R.G.; Holbrook, B.; Lander, R.L.; Moskaleva, A.; Neher, C.; Pasner, J.; Tripathi, M.; /UC, Davis; Brau, J.E.; Frey, R.E.; Strom, D.; /Oregon U.; Breidenbach, M.; Freytag, D.; Haller, G.; Herbst, R.; Nelson, T.; /SLAC; Schier, S.; Schumm, B.; /UC, Santa Cruz

    2012-09-14T23:59:59.000Z

    The SiD collaboration is developing a Si-W sampling electromagnetic calorimeter, with anticipated application for the International Linear Collider. Assembling the modules for such a detector will involve special bonding technologies for the interconnections, especially for attaching a silicon detector wafer to a flex cable readout bus. We review the interconnect technologies involved, including oxidation removal processes, pad surface preparation, solder ball selection and placement, and bond quality assurance. Our results show that solder ball bonding is a promising technique for the Si-W ECAL, and unresolved issues are being addressed.

  14. Metallurgy, thermal stability, and failure mode of the commercial Bi-Te-based thermoelectric modules.

    SciTech Connect (OSTI)

    Yang, Nancy Y. C.; Morales, Alfredo Martin

    2009-02-01T23:59:59.000Z

    Bi-Te-based thermoelectric (TE) alloys are excellent candidates for power generation modules. We are interested in reliable TE modules for long-term use at or below 200 C. It is known that the metallurgical characteristics of TE materials and of interconnect components affect the performance of TE modules. Thus, we have conducted an extensive scientific investigation of several commercial TE modules to determine whether they meet our technical requirements. Our main focus is on the metallurgy and thermal stability of (Bi,Sb){sup 2}(Te,Se){sup 3} TE compounds and of other materials used in TE modules in the temperature range between 25 C and 200 C. Our study confirms the material suite used in the construction of TE modules. The module consists of three major components: AlN cover plates; electrical interconnects; and the TE legs, P-doped (Bi{sub 8}Sb{sub 32})(Te{sub 60}) and N-doped (Bi{sub 37}Sb{sub 3})(Te{sub 56}Se{sub 4}). The interconnect assembly contains Sn (Sb {approx} 1wt%) solder, sandwiched between Cu conductor with Ni diffusion barriers on the outside. Potential failure modes of the TE modules in this temperature range were discovered and analyzed. The results show that the metallurgical characteristics of the alloys used in the P and N legs are stable up to 200 C. However, whole TE modules are thermally unstable at temperatures above 160 C, lower than the nominal melting point of the solder suggested by the manufacture. Two failure modes were observed when they were heated above 160 C: solder melting and flowing out of the interconnect assembly; and solder reacting with the TE leg, causing dimensional swelling of the TE legs. The reaction of the solder with the TE leg occurs as the lack of a nickel diffusion barrier on the side of the TE leg where the displaced solder and/or the preexisting solder beads is directly contact the TE material. This study concludes that the present TE modules are not suitable for long-term use at temperatures above 160 C due to the reactivity between the Sn-solder and the (Bi,Sb){sup 2}(Te,Se){sup 3} TE alloys. In order to deploy a reliable TE power generator for use at or below 200 C, alternate interconnect materials must be used and/or a modified module fabrication technique must be developed.

  15. High-Temperature Die-Attaches for SiC Power Devices Amandine MASSON1, Cyril BUTTAY1, Herve MOREL1, Christophe RAYNAUD1,

    E-Print Network [OSTI]

    Paris-Sud XI, UniversitƩ de

    of the solder joint degrade. The ratio between the melting temperature (Tm) and the operating temperature (To electronic systems which will be installed in hot areas. SiC power devices can operate at high temperature operating temperature range. Furthermore, the reliability of the attach is directly linked to its operating

  16. Proceedings of FEDSM99 3rd ASME/JSME Joint Fluids Engineering Conference

    E-Print Network [OSTI]

    Sussman, Mark

    procedures and equipment (e.g., dye- assisted laser surgery), medical diagnostics manufacturing (e dispensing solder in mi- croelectronics manufacturing processes (Bernardini et al., 1991), biomedical.g., printing DNA strands), micro-optics manufacturing, macro ow control, IC thermal management, micro

  17. GENERATION OF PRESSURE BY EWOD-ACTUATED DROPLETS J. Jenkins*

    E-Print Network [OSTI]

    554 · 2006 IEEE International Solid-State Circuits Conference ISSCC 2006 / SESSION 30 / SILICON-tipped silicon extracellular electrodes [1]. This paper describes the development of a mixed-signal integrated circuit that will be flip- chip bonded to the back of the UEA using Au/Sn reflow soldering. This chip

  18. Liquid Wall Science in other Scientific Pursuits and Applications

    E-Print Network [OSTI]

    Abdou, Mohamed

    /sheet/ribbon/sphere casting, flood/jet soldering, ocean waves, hull design, ocean/river hydraulic engineering, surfing, liquid, wetted-wall absorbers/chemical reactor, condensers, vertical tube evaporator, film cooling of turbine vortices; ·Low Joule and Viscous dissipation; ·Insignificant effect on the hydraulic drag. 2-D turbulence

  19. -Ris Report No. 371 Ris National Laboratory

    E-Print Network [OSTI]

    RADIOGRAPHY PAPER PHOTOGRAPHIC FILMS QUALITY CONTROL REVIEWS SOLDERED JOINTS USES WELDED JOINTS X of the radiographic image was checked on U/Al blocks and plates, Al and Fe blocks, and fiber-reinforced composites.2. Radiographic quality of U/Al blocks 89 7.3. Radiographic quality of Al and Fe blocks 90 7.4. Radiographic

  20. PERMIT FOR WELDING AND CUTTING OPERATIONS INSTRUCTIONS: This permit must be completed for all operations involving open

    E-Print Network [OSTI]

    Papautsky, Ian

    PERMIT FOR WELDING AND CUTTING OPERATIONS INSTRUCTIONS: This permit must be completed for all/Area: Description of Work to be Performed: (check where appropriate) Welding Cutting Soldering Burning Type OF ACCIDENTAL FIRES DUE TO WELDING OR CUTTING OPERATIONS 1: Do not perform cutting or welding work where an open

  1. Optical Inspection of Welding Seams Fabian Timm1,2

    E-Print Network [OSTI]

    Optical Inspection of Welding Seams Fabian Timm1,2 , Thomas Martinetz1 , and Erhardt Barth1,2 1 present a framework for automatic inspection of welding seams based on specular reflections. To this end by using welding techniques. Soldering and welding techniques are common in diverse areas such as printed

  2. 2006 Minerals Yearbook U.S. Department of the Interior

    E-Print Network [OSTI]

    metal consumed domestically was $394 million. Industry stocks at yearend increased by 46% compared scrapped alloys of tin and recycled in those same alloy industries. Secondary tin from recycled fabricated% of the reported primary tin used domestically. The major uses were as follows: electrical solders, 28%; metal

  3. Appendixes Appendix I. Published Reports of Less Common Causes of Elevated Blood Lead Levels (EBLLs) in Children.

    E-Print Network [OSTI]

    Description Ref. # Occupational Take Home Exposures Battery reclamation Lead carried home by battery workers. (Only a minority of battery workers showered or changed clothes before going home.) E Twelve (75%) of 16 Bulk-water storage tank Lead leached from soldered seams and brass fittings in bulk- water storage

  4. Caroline S. Lee Graduate Student,

    E-Print Network [OSTI]

    Eagar, Thomas W.

    and Rymaszewski, 1989, pp. 1151-1154). This study focuses on C4 solder bumps to understand the Pb/Sn surface layer of pitch separation require- ments between bumps and the self-aligning property of C4 die attach (Tummala typically consists of a proprie- tary mix of reactive and refractory metals, were studied. Specifically, C4

  5. Measurement of Resistance and Strength of Conductor Splices in the MICE Coupling Magnets

    SciTech Connect (OSTI)

    Xu, Feng Yu; Pan, Heng; Wu, Hong; Lui, X. K.; Li, E.; Dietderich, Dan; Higley, Hugh; Tam, D. G.; Trillaud, Fredric; Wang, Li; Green, M.A.

    2009-08-19T23:59:59.000Z

    The superconducting magnets for the Muon Ionization Cooling Experiment [1] (MICE) use a copper based Nb-Ti conductor with un-insulated dimensions of 0.95 by 1.60 mm. There may be as many as twelve splices in one MICE superconducting coupling coil. These splices are to be wound in the coil. The conductor splices produce Joule heating, which may cause the magnet to quench. A technique of making conductor splices was developed by ICST. Two types of 1-meter long of soldered lap-joints have been tested. Side-by-side splices and up-down one splices were studied theoretically and experimentally using two types of soft solder made of eutectic tin-lead solder and tin-silver solder. The resistances of the splices made by ICST were tested at LBNL at liquid helium temperatures over a range of magnetic fields up to 5 T. The breaking strength of 250 mm long splices was also measured at room temperature and liquid nitrogen temperature.

  6. WInd-and-react Bi-2212 coil development for accelerator magnets

    E-Print Network [OSTI]

    Godeke, A.

    2011-01-01T23:59:59.000Z

    Figure 2. Coil HTS-SC08 and witness barrels and wires afterO S T Bi-2212 round wire. Coil ID HTS-SC02 HTS-SC04 HTS-SC06with the wires soldered to the barrels. c Coil ID HTS-SC04

  7. ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton GIT 2011

    E-Print Network [OSTI]

    Colton, Jonathan S.

    temperatures, easy to diffusion bond. · Iron, titanium and copper also can be diffusion bonded, because · Diffusion bonding · Soldering and brazing · Fusion welding #12;ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2011 3 Diffusion bonding · High pressure and temperature for extended periods

  8. Safe Operating Procedure (Revised 7/09)

    E-Print Network [OSTI]

    Farritor, Shane

    -800 4 5 6 8 8 9 10 4 5 6 8 9 12 14 Torch Brazing (TB) -- -- 3 or 4 Torch Soldering (TS) -- -- 2 Carbon zone without going below the minimum. In oxyfuel gas welding, cutting, or brazing where the torch lenses used, since not all brands are the same or provide equal protection against flash. · For laser

  9. Open Archive TOULOUSE Archive Ouverte (OATAO) OATAO is an open access repository that collects the work of Toulouse researchers and

    E-Print Network [OSTI]

    Paris-Sud XI, UniversitƩ de

    power modules devices are paramount components in the aeronautical, automotive and military applications management (Fig .1). The dielectric ceramic substrate is double bonded with thick copper or aluminum such as AlSiC, copper or aluminum. The brazing is achieved using solder alloys considered as one

  10. The series is designed to provide an industry perspective on smart lighting technologies and markets. Each speaker will also share personal insights about their career paths.

    E-Print Network [OSTI]

    Varela, Carlos

    market spaces such as display, automotive and general lighting. Product performance and reliability. This talk describes some of the issues related to LED product performance and reliability and how advanced and solder materials for semiconductor packaging. Alpha also offers product technologies for the Photovoltaic

  11. Welding Process Fundamentals* Thomas W. Eagar and Aaron D. Mazzeo, Massachusetts Institute of Technology

    E-Print Network [OSTI]

    Eagar, Thomas W.

    (such as fastening, adhesive bonding, soldering, brazing, arc welding, diffusion bonding, and resistance the material surrounding it. Although some pro- cesses, such as diffusion bonding, can achieve results solids will bond if their surfaces are brought into intimate contact. One factor that generally inhibits

  12. Updated April 2010 Reliability Concerns Associated with PV Technologies

    E-Print Network [OSTI]

    it periodically. 1.0 Wafer Silicon 1.1 Cracked cells (bonding processes, strain, etc.) [1-4] 1.2 Solder joint and diffusion of silver gridlines/contacts #12;3 Updated April 2010 6.9 Electromigration due to high current

  13. Low Temperature Transient Liquid Phase (LTTLP) Bonding for Au/Cu

    E-Print Network [OSTI]

    Eagar, Thomas W.

    of Technology, Cambridge, MA 02139 TheLow Temperature TransientLiquidPhase Diffusion Bonding (LTTLP) process has) ) M. M. Hou Low Temperature Transient Liquid Phase (LTTLP) Bonding for Au/Cu and Cu been bonded to copper heatsink.s at temperatures less than 160"C, using /n-Sn eutectic solders. After

  14. Air Gap Tunin Yilin Mao, Yashwanth

    E-Print Network [OSTI]

    Elsherbeni, Atef Z.

    Air Gap Tunin Yilin Mao, Yashwanth Electrical Engineering Departm The Unive ymao1@olemiss.edu, ypadooru@ Abstract-- An adjustable air gap was proposed the resonant frequency of patch antennas the frequency of coaxially fed p center conductor has to be de-soldered and r time the width of the air gap

  15. The elemental interaction in the electrodeposited Pb-Sn/electroless Ni-P deposit/Al multilayer upon heat treatment

    SciTech Connect (OSTI)

    Lin, K.L.; Chang, J.T. (National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Materials Science and Engineering)

    1994-03-01T23:59:59.000Z

    The deposition of electroless nickel on aluminum is a relatively simple process. It is thus feasible to manufacture an electrodeposited solder bump on aluminum with the aid of an electroless nickel intermediate layer. The Al/electroless Ni/Pb-SN combination has been successfully developed in the present work. For this application, however, it is necessary to understand the possible interactions during protracted utilization of the multilayer combination. Nickel is reported to undergo the smallest rate of dissolution and the rate of reaction with solder among various materials is commonly applied in electronics. Thus, nickel has been applied as a diffusion barrier in electronic packaging. Electroless nickel is expected to have a similar barrier property. The interaction between nickel and electrodeposited tin forms Ni[sub 3]Sn[sub 4] at 190 C (12); Ni[sub 3]Sn is formed when the nickel surface is roughened. Ni[sub 3]Sn[sub 2] was found after soldering on electroless Ni-P. Despite all this work, there are still few investigations on the behavior of electrodeposited solder and electroless nickel deposits. The authors investigated the interphases formed in the Al/electroless Ni-P/Pb-Sn electro-deposit multilayer combination.

  16. Preparation of Ni-Sn alloys by an electroless-deposition method

    SciTech Connect (OSTI)

    Shimauchi, Hidenori; Ozawa, Susumu; Tamura, Keiu; Osaka, Tetsuya (Waseda Univ., Tokyo (Japan). Dept. of Applied Chemistry)

    1994-06-01T23:59:59.000Z

    Ni-Sn alloy is expected for as a functional material, because of its excellent corrosion resistance, wear resistance, and solderability. Electroless-deposited Ni-Sn alloy films were investigated to increase tin content in the deposit. The maximum tin contents of electroless Ni-Sn-P and Ni-Sn-B were ca. 30 atom percent (a/o) and 42 a/o, respectively. The maximum tin contents in the case of Ni-Sn-B was nearly equal to that of electrodeposited Ni-Sn alloy already reported. The crystallinity of Ni-Sn-P and Ni-Sn-B alloys was raised up with an increase in tin content. The corrosion resistance of Ni-Sn-P and Ni-Sn-B alloys was between that of amorphous and crystalline electroless-deposited Ni-P. Codeposition of tin into Ni-P films improved solderability, but into the Ni-B films, the solderability of Ni-Sn-B films situated in the region between those of Ni-P and NiB, because the solderability of NiB is higher.

  17. ME 354, MECHANICS OF MATERIALS LAB February 2010 NJS

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    of a solder wire at room temperature. Specifically, creep tests1 for different applied loads will be used. 3) Standard creep test machine: This is a dead-weight loading setup with top and bottom grips) Install the top end of the specimen in the top grip of the creep test and lightly tighten the wing-nut. 5

  18. ME 354, MECHANICS OF MATERIALS LAB February 2009 NJS

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    of a solder wire at room temperature. Specifically, creep tests1 for different applied loads will be used. 3) Standard creep test machine: This is a dead-weight loading setup with top and bottom grips) Install the top end of the specimen in the top grip of the creep test and lightly tighten the wing-nut. 5

  19. 1 Copyright 2007 by ASME Proceedings of IMECE 2007

    E-Print Network [OSTI]

    Texas at Arlington, University of

    the likelihood of arcing across solder nodes for high-power components. An #12;2 Copyright © 2007 by ASME b. Back1 Copyright © 2007 by ASME Proceedings of IMECE 2007 2007 ASME International Mechanical Engineering_Bigdeli@Whirlpool.com ABSTRACT The problem of arc tracking in power electronic enclosures was studied through simple bench

  20. Flow visualization of molten alloys using real-time neutron radiography

    E-Print Network [OSTI]

    Bennett, Tami Norene

    1994-01-01T23:59:59.000Z

    The objective of this research is to visualize the flow of molten alloys using real-time neutron radiography. Initial experiments were performed using solder (50% tin, 50% lead), with nickel tracer particles, heated in a furnace to its liquid state...

  1. STATE OF UTAH CONTRACT NUMBER: MA049 January 24, 2014 Page 1 of 3 Includes Codale Lamp and Ballast

    E-Print Network [OSTI]

    Capecchi, Mario R.

    @codale.com Reporting Type: Line Item and Summary Brand/trade name: Phillips Advance EFI Hubbell Intermatic Eiko Ushio% Off 15% Off 12% Off Hand Tools 23% Off 25% Off 20% Off 39% Off Plumbing 23% Off 15% Off 15% Off Power 20% Off 39% Off Security 23% Off 20% Off 12% Off 39% Off Welding & Soldering 23% Off 15% Off 12% Off

  2. NATIONAL RADIO ASTRONOMY OBSERVATORY ELECTRONICS DIVISION TECHN

    E-Print Network [OSTI]

    Groppi, Christopher

    J. Coe J. Davis H. Hvatum R. Lacasse P. Lilie C. Moore P. Napier J. Payne R. Widene Libraries (CV GB be burned off with a soldering iron and is bonded into a red/green pair of wires (bifilar) with polyvinyl

  3. 1 CONFIDENTIAL1 CONFIDENTIAL GreenField Solar

    E-Print Network [OSTI]

    Rollins, Andrew M.

    1 CONFIDENTIAL1 CONFIDENTIAL GreenField Solar: Testing and Reliability needs of CPV Systems Dr-south movements only required once a day West East #12;CONFIDENTIAL 7 Industry-wide issues - Solar Issues from Ā­ Encapsulation failures Ā­ Inverter reliability Solder fatigue Encapsulant browning Junction box failures

  4. Kinesthetic Learning in the Classroom "Great ideas originate in the muscles" Thomas Edison

    E-Print Network [OSTI]

    Tranquillo, Joseph V.

    and soldering a circuit board, connecting and sealing tubes in a flow loop or drilling a precise hole, these skills are practiced and mastered in a lab setting. The version of kinesthetic learning considered here to be signatures of a mature mind, humans learn best by doing something concrete first, and then abstracting

  5. Should you have your water tested?

    E-Print Network [OSTI]

    O'Laughlin, Jay

    dissolved solids (TDS), corrosion index, and other parameters depending on proximity to potential sources guests have recurrent incidents of gastrointestinal illness. Household water plumbing contains lead pipes, fittings, or solder joints. You are buying a home and wish to assess the safety and quality of the existing

  6. Leaching studies for tin recovery from waste e-scrap

    SciTech Connect (OSTI)

    Jha, Manis Kumar, E-mail: maniskrjha@gmail.com [Metal Extraction and Forming Division, National Metallurgical Laboratory (NML), Jamshedpur 831 007 (India); Choubey, Pankaj Kumar; Jha, Amrita Kumari; Kumari, Archana [Metal Extraction and Forming Division, National Metallurgical Laboratory (NML), Jamshedpur 831 007 (India); Lee, Jae-chun, E-mail: jclee@kigam.re.kr [Mineral Resources Research Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Kumar, Vinay [Metal Extraction and Forming Division, National Metallurgical Laboratory (NML), Jamshedpur 831 007 (India); Jeong, Jinki [Mineral Resources Research Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of)

    2012-10-15T23:59:59.000Z

    Printed circuit boards (PCBs) are the most essential components of all electrical and electronic equipments, which contain noteworthy quantity of metals, some of which are toxic to life and all of which are valuable resources. Therefore, recycling of PCBs is necessary for the safe disposal/utilization of these metals. Present paper is a part of developing Indo-Korean recycling technique consists of organic swelling pre-treatment technique for the liberation of thin layer of metallic sheet and the treatment of epoxy resin to remove/recover toxic soldering material. To optimize the parameters required for recovery of tin from waste PCBs, initially the bench scale studies were carried out using fresh solder (containing 52.6% Sn and 47.3% Pb) varying the acid concentration, temperature, mixing time and pulp density. The experimental data indicate that 95.79% of tin was leached out from solder material using 5.5 M HCl at fixed pulp density 50 g/L and temperature 90 Degree-Sign C in mixing time 165 min. Kinetic studies followed the chemical reaction controlled dense constant size cylindrical particles with activation energy of 117.68 kJ/mol. However, 97.79% of tin was found to be leached out from solder materials of liberated swelled epoxy resin using 4.5 M HCl at 90 Degree-Sign C, mixing time 60 min and pulp density 50 g/L. From the leach liquor of solder materials of epoxy resin, the precipitate of sodium stannate as value added product was obtained at pH 1.9. The Pb from the leach residue was removed by using 0.1 M nitric acid at 90 Degree-Sign C in mixing time 45 min and pulp density 10 g/L. The metal free epoxy resin could be disposed-of safely/used as filling material without affecting the environment.

  7. Phosphate glasses for radioactive, hazardous and mixed waste immobilization

    DOE Patents [OSTI]

    Cao, Hui (Middle Island, NY); Adams, Jay W. (Stony Brook, NY); Kalb, Paul D. (Wading River, NY)

    1999-03-09T23:59:59.000Z

    Lead-free phosphate glass compositions are provided which can be used to immobilize low level and/or high level radioactive wastes in monolithic waste forms. The glass composition may also be used without waste contained therein. Lead-free phosphate glass compositions prepared at about 900.degree. C. include mixtures from about 1 mole % to about 6 mole %.iron (III) oxide, from about 1 mole % to about 6 mole % aluminum oxide, from about 15 mole % to about 20 mole % sodium oxide or potassium oxide, and from about 30 mole % to about 60 mole % phosphate. The invention also provides phosphate, lead-free glass ceramic glass compositions which are prepared from about 400.degree. C. to about 450.degree. C. and which includes from about 3 mole % to about 6 mole % sodium oxide, from about 20 mole % to about 50 mole % tin oxide, from about 30 mole % to about 70 mole % phosphate, from about 3 mole % to about 6 mole % aluminum oxide, from about 3 mole % to about 8 mole % silicon oxide, from about 0.5 mole % to about 2 mole % iron (III) oxide and from about 3 mole % to about 6 mole % potassium oxide. Method of making lead-free phosphate glasses are also provided.

  8. Phosphate glasses for radioactive, hazardous and mixed waste immobilization

    DOE Patents [OSTI]

    Cao, Hui (Middle Island, NY); Adams, Jay W. (Stony Brook, NY); Kalb, Paul D. (Wading River, NY)

    1998-11-24T23:59:59.000Z

    Lead-free phosphate glass compositions are provided which can be used to immobilize low level and/or high level radioactive wastes in monolithic waste forms. The glass composition may also be used without waste contained therein. Lead-free phosphate glass compositions prepared at about 900.degree. C. include mixtures from about 1 mole % to about 6 mole % iron (III) oxide, from about 1 mole % to about 6 mole % aluminum oxide, from about 15 mole % to about 20 mole % sodium oxide or potassium oxide, and from about 30 mole % to about 60 mole % phosphate. The invention also provides phosphate, lead-free glass ceramic glass compositions which are prepared from about 400.degree. C. to about 450.degree. C. and which includes from about 3 mole % to about 6 mole % sodium oxide, from about 20 mole % to about 50 mole % tin oxide, from about 30 mole % to about 70 mole % phosphate, from about 3 mole % to about 6 mole % aluminum oxide, from about 3 mole % to about 8 mole % silicon oxide, from about 0.5 mole % to about 2 mole % iron (III) oxide and from about 3 mole % to about 6 mole % potassium oxide. Method of making lead-free phosphate glasses are also provided.

  9. Explosive complexes

    DOE Patents [OSTI]

    Huynh, My Hang V. (Los Alamos, NM)

    2011-08-16T23:59:59.000Z

    Lead-free primary explosives of the formula [M.sup.II(A).sub.R(B.sup.X).sub.S](C.sup.Y).sub.T, where A is 1,5-diaminotetrazole, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  10. High thermoelectric performance by resonant dopant indium in nanostructured SnTe

    E-Print Network [OSTI]

    Liao, Bolin

    From an environmental perspective, lead-free SnTe would be preferable for solid-state waste heat recovery if its thermoelectric figure-of-merit could be brought close to that of the lead-containing chalcogenides. In this ...

  11. List of Publications (Reverse Chronological Order) Click on the blue publication numbers to access the full text pdfs. You may need to be logged in to your institution web pages

    E-Print Network [OSTI]

    Ojovan, Michael

    Properties of Ca-Doped BiFeO3 Ceramics: From p-Type Semiconduction to Oxide-Ion Conduction, Nahum Masó and lead-free Ba2NdTi2Nb3O15 ceramics, L. Burianova, S. Panos, M. C. Stennett, A. R. West, G Subodh, M. T

  12. INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS D: APPLIED PHYSICS J. Phys. D: Appl. Phys. 37 (2004) 921924 PII: S0022-3727(04)72598-X

    E-Print Network [OSTI]

    Cao, Wenwu

    by the Czochralski method. X-ray energy dispersive spectrometry showed that SBNN70 crystals have a stoichiometric, and a deep energy level of 3.54 eV was found. The SBNN70 crystal has better than 70% optical transmittance of lead- free ferroelectric materials with a high Curie temperature and better functional properties

  13. Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 are transparent materials with

    E-Print Network [OSTI]

    Harmon, Julie P.

    Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 that are lead-free. If we cannot shield effectively at nanofiller levels where transparency is maintained, we, Condensed Matter, Vol. 15, 8927 (2003). 21. "Highly Nonlinear Bismuth-Oxide Fiber for Smooth Supercontinuun

  14. Phase transition and ferroelectric properties of epitaxially strained KNbO3/NaNbO3 superlattice

    E-Print Network [OSTI]

    Cao, Wenwu

    , because lead oxide vaporizes during the fabrica- tion process, which is harmful to the environment: 10.1063/1.3053148 Lead based piezoelectric ceramic Pb Zr1-xTix O3 PZT has been widely used, the devel- opment of lead-free ferroelectric materials with properties comparable to lead based compounds

  15. Phosphate glasses for radioactive, hazardous and mixed waste immobilization

    DOE Patents [OSTI]

    Cao, H.; Adams, J.W.; Kalb, P.D.

    1999-03-09T23:59:59.000Z

    Lead-free phosphate glass compositions are provided which can be used to immobilize low level and/or high level radioactive wastes in monolithic waste forms. The glass composition may also be used without waste contained therein. Lead-free phosphate glass compositions prepared at about 900 C include mixtures from about 1 mole % to about 6 mole % iron (III) oxide, from about 1 mole % to about 6 mole % aluminum oxide, from about 15 mole % to about 20 mole % sodium oxide or potassium oxide, and from about 30 mole % to about 60 mole % phosphate. The invention also provides phosphate, lead-free glass ceramic glass compositions which are prepared from about 400 C to about 450 C and which includes from about 3 mole % to about 6 mole % sodium oxide, from about 20 mole % to about 50 mole % tin oxide, from about 30 mole % to about 70 mole % phosphate, from about 3 mole % to about 6 mole % aluminum oxide, from about 3 mole % to about 8 mole % silicon oxide, from about 0.5 mole % to about 2 mole % iron (III) oxide and from about 3 mole % to about 6 mole % potassium oxide. Method of making lead-free phosphate glasses are also provided. 8 figs.

  16. Phosphate glasses for radioactive, hazardous and mixed waste immobilization

    DOE Patents [OSTI]

    Cao, H.; Adams, J.W.; Kalb, P.D.

    1998-11-24T23:59:59.000Z

    Lead-free phosphate glass compositions are provided which can be used to immobilize low level and/or high level radioactive wastes in monolithic waste forms. The glass composition may also be used without waste contained therein. Lead-free phosphate glass compositions prepared at about 900 C include mixtures from about 1--6 mole % iron (III) oxide, from about 1--6 mole % aluminum oxide, from about 15--20 mole % sodium oxide or potassium oxide, and from about 30--60 mole % phosphate. The invention also provides phosphate, lead-free glass ceramic glass compositions which are prepared from about 400 C to about 450 C and which includes from about 3--6 mole % sodium oxide, from about 20--50 mole % tin oxide, from about 30--70 mole % phosphate, from about 3--6 mole % aluminum oxide, from about 3--8 mole % silicon oxide, from about 0.5--2 mole % iron (III) oxide and from about 3--6 mole % potassium oxide. Method of making lead-free phosphate glasses are also provided. 8 figs.

  17. Lead Content of Brass Plumbing Components J Barry Maynard

    E-Print Network [OSTI]

    Maynard, J. Barry

    Lead Content of Brass Plumbing Components J Barry Maynard University of Cincinnati 2008 Water are leaded brass and hence comprise a potential source of Pb in compliance testing under the Lead and Copper be marketed as "lead free". In true no-lead brasses, Bi and Se are used in place of Pb (http

  18. Microwave spectrum of o-benzyne produced in a discharge nozzle S. G. Kukolicha)

    E-Print Network [OSTI]

    Department of Chemistry, University of Arizona, Tucson, Arizona 85721 M. C. McCarthy and P. Thaddeus Harvard recently been implicated in gasoline combustion reactions and antitumor activity of enediynes. Twenty that o-benzyne may play a significant role in the combustion of lead-free gasoline. The theoretical

  19. Explosive complexes

    DOE Patents [OSTI]

    Huynh, My Hang V. (Los Alamos, NM)

    2009-09-22T23:59:59.000Z

    Lead-free primary explosives of the formula [M.sup.II(A).sub.R(B.sup.X).sub.S](C.sup.Y).sub.T, where A is 1,5-diaminotetrazole, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  20. Modeling of microstructural effects on electromigration failure

    SciTech Connect (OSTI)

    Ceric, H. [Christian Doppler Laboratory for Reliability Issues in Microelectronics at the Institute for Microelectronics, TU Wien (Austria); Orio, R. L. de; Zisser, W.; Selberherr, S. [Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien (Austria)

    2014-06-19T23:59:59.000Z

    Current electromigration models used for simulation and analysis of interconnect reliability lack the appropriate description of metal microstructure and consequently have a very limited predictive capability. Therefore, the main objective of our work was obtaining more sophisticated electromigration tools. The problem is addressed through a combination of different levels of atomistic modeling and already available, continuum level macroscopic models. A novel method for an ab initio calculation of the effective valence for electromigration is presented and its application on the analysis of EM behavior is demonstrated. Additionally, a simple analytical model for the early electromigration lifetime is obtained. We have shown that its application provides a reasonable estimate for the early electromigration failures including the effect of microstructure. A simulation study is also applied on electromigration failure in tin solder bumps, where it contributed the understanding of the role of tin crystal anisotropy in the degradation mechanism of solder bumps.

  1. Phase 2 of the array automated assembly task for the low cost silicon solar array project. Fifth quarterly report

    SciTech Connect (OSTI)

    Petersen, R.C.; Anderson, J.R.

    1980-01-01T23:59:59.000Z

    This program focuses attention on one key step of a proposed process sequence for mass production of inexpensive silicon solar arrays for terrestrial use. The process step of concern is the metallization of the solar cell. Solarex has proposed that the metallization be accomplished by a single electroless plating of nickel followed by a dip in molten solder, and Solarex manufactures solar cells using this procedure. ing, cleaning and annealing. Motorola has recommended a process which includes the electroless nickel plate and solder dip of the Solarex process, but which precedes these steps with a number of additional steps of palladium plating, cleaning and annealing. Motorola has claimed that these additional steps are necessary to assure proper ohmic contact with the silicon while at the same time avoiding excessive nickel penetration into the silicon. This program comprises a technical comparison of the Solarex and Motorola processes. Progress is reported.

  2. An assessment of alternatives for replacing Freon 113 in bench type electrical circuit board cleaning at Fermi National Accelerator Laboratory

    SciTech Connect (OSTI)

    Isakson, K.; Vessell, A.L.

    1994-07-01T23:59:59.000Z

    Fermilab is presently phasing out all solvents containing Freon-113 (CFC-113) as part of the continuing Waste Minimization Program. These solvents are used primarily in cleaning the flux off of electronic circuit boards after soldering, specifically in bench type work. Title VI of the Clean Air Act mandates a production phase-out for ozone depleting substances, like CFC-113, by the year 2000. Our study addresses this issue by evaluating and choosing alternative non-CFC solvents to replace the CFC-1 13 solvents at Fermilab. Several potential non-CFC cleaning solvents were tested. The evaluation took place in three parts: controlled experimental evaluation, chemical composition evaluation, and employee performed evaluation. First, we performed a controlled nine-step procedure with the potential solvents where each was evaluated in categories such as cleaning effectiveness, odor, residue, type of output and drying time. Next, we listed the chemical composition of each solvent. We noted which solvents contained hydrochlorofluorocarbons because they are targeted for phase-out in the future and will be recognized as interim solutions only. Finally, after preliminary testing, five solvents were chosen as the best options. These solvents were sent to be tested by Fermilab employees who use such materials. Their opinions are valuable not only because they are knowledgeable in this field, but also because they will be using the solvents chosen to replace the CFC-113 solvents. The results favored two ``best alternatives``: Safezone Solvent Flux Remover by Miller-Stephenson and E-Series CFC Free Flux-Off 2000 by Chemtech. Another possible solution also pursued is the no-clean solder option. In our study, we were not able to thoroughly investigate the many types of no-clean solders because of time and financial constraints. The testing that was done, however, showed that no-clean solder was a viable alternative in many cases.

  3. Development of the bus joint for the ITER Central Solenoid

    SciTech Connect (OSTI)

    Martovetsky, Nicolai N [ORNL] [ORNL; Irick, David Kim [ORNL] [ORNL; Kenney, Steven J [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The terminations of the Central Solenoid (CS) modules are connected to the bus extensions by joints located outside the CS in the gap between the CS and Torodial Field (TF) assemblies. These joints have very strict space limitations. Low resistance is a common requirement for all ITER joints. In addition, the CS bus joints will experience and must be designed to withstand significant variation in the magnetic field of several tenths of a Tesla per second during initiation of plasma. The joint resistance is specified to be less than 4 nOhm. The joints also have to be soldered in the field and designed with the possibility to be installed and dismantled in order to allow cold testing in the cold test facility. We have developed coaxial joints that meet these requirements and have demonstrated the feasibility to fabricate and assemble them in the vertical configuration. We introduced a coupling cylinder with superconducting strands soldered to the surface of the cable that can be installed in the ITER assembly hall and at the Cold Test Facility. This cylinder serves as a transition area between the CS module and the bus extension. We made two racetrack samples and tested four bus joints in our Joint Test Apparatus. Resistance of the bus joints was measured by a decay method and by a microvoltmeter; the value of the current was measured by the Hall probes. This measurement method was verified in the previous tests. The resistance of the joints varied insignificantly from 1.5 to 2 nOhm. One of the challenges associated with a soldered joint is the inability to use corrosive chemicals that are difficult to clean. This paper describes our development work on cable preparation, chrome removal, compaction, soldering, and final assembly and presents the test results.

  4. The role of electroplated coatings in metal joining

    SciTech Connect (OSTI)

    Dini, J.W. [Lawrence Livermore National Lab., CA (United States)

    1996-05-01T23:59:59.000Z

    Electroplated and electroless coatings often play an important role in soldering, brazing, and welding operations. Thin deposits applied to critical surfaces before the joining operations can provide the difference between success and failure. Diffusion welding applications sometimes require coatings to help promote joining. For some applications, electroplating by itself can be used to join metals that cannot be welded or brazed because of metallurgical incompatibility. The use of electroplated coatings for these various joining applications is reviewed here.

  5. Low resistivity contact to iron-pnictide superconductors

    DOE Patents [OSTI]

    Tanatar, Makariy; Prozorov, Ruslan; Ni, Ni; Bud'ko, Sergey; Canfield, Paul

    2013-05-28T23:59:59.000Z

    Method of making a low resistivity electrical connection between an electrical conductor and an iron pnictide superconductor involves connecting the electrical conductor and superconductor using a tin or tin-based material therebetween, such as using a tin or tin-based solder. The superconductor can be based on doped AFe.sub.2As.sub.2, where A can be Ca, Sr, Ba, Eu or combinations thereof for purposes of illustration only.

  6. Planar triode pulser socket

    DOE Patents [OSTI]

    Booth, Rex (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes.

  7. Planar triode pulser socket

    DOE Patents [OSTI]

    Booth, R.

    1994-10-25T23:59:59.000Z

    A planar triode is mounted in a PC board orifice by means of a U-shaped capacitor housing and anode contact yoke removably attached to cathode leg extensions passing through and soldered to the cathode side of the PC board by means of a PC cathode pad. A pliant/flexible contact attached to the orifice make triode grid contact with a grid pad on the grid side of the PC board, permitting quick and easy replacement of bad triodes. 14 figs.

  8. Modeling non-isothermal intermetallic layer growth in the 63Sn-37Pb/Cu system

    SciTech Connect (OSTI)

    Vianco, P.T.; Hopkins, P.L.; Erickson, K.L.; Frear, D.R.; Davidson, R.

    1996-12-31T23:59:59.000Z

    A model describing diffusion-controlled growth of multiple intermetallic layers and the displacement of the interfaces between layers was developed and implemented in a 1-D computer code based on method-of-lines. The code was applied to analysis of intermetallic layer growth in isothermal solder aging experiments performed with 100 Sn/Cu and 63Sn-37Pb/Cu solder-substrate systems. Analyses indicated that intermetallic layer growth was consistent with a bulk diffusion mechanism involving Cu and/or Sn. In this work, nonisothermal solder-aging experiments were done with the 63Sn- 37Pb/Cu system using two temperature histories (4 cycles/day between 223-443 K, and 72 cycles/day between 223-443 K). Isothermal experiments were also done at 443 K. Thickness of Cu{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallic layers were determined vs time for each temperature history. An updated version of the model and code were used to predict the intermetallic layer growth. Arrhenius expressions for diffusion coefficients in both Cu3Sn and Cu6Sn5 layers were determined. Agreement between prediction and experiment was generally good. In some cases, predicted layer growth was less than experiment, but within error. This paper describes the nonisothermal experiments and a comparison of predicted and observed layer growth vs time.

  9. Magnetically attached sputter targets

    DOE Patents [OSTI]

    Makowiecki, D.M.; McKernan, M.A.

    1994-02-15T23:59:59.000Z

    An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

  10. Method of fabricating a solar cell array

    DOE Patents [OSTI]

    Lazzery, Angelo G. (Oaklyn, NJ); Crouthamel, Marvin S. (Pennsauken, NJ); Coyle, Peter J. (Oaklyn, NJ)

    1982-01-01T23:59:59.000Z

    A first set of pre-tabbed solar cells are assembled in a predetermined array with at least part of each tab facing upward, each tab being fixed to a bonding pad on one cell and abutting a bonding pad on an adjacent cell. The cells are held in place with a first vacuum support. The array is then inverted onto a second vacuum support which holds the tabs firmly against the cell pads they abut. The cells are exposed to radiation to melt and reflow the solder pads for bonding the tab portions not already fixed to bonding pads to these pads.

  11. FMEA on the superconducting torus for the Jefferson Lab 12 GeV accelerator upgrade

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ghoshal, Probir K.; Biallas, George H.; Fair, Ruben J.; Rajput-Ghoshal, Renuka; Schneider, William J.; Legg, Robert A.; Kashy, David H.; Hogan, John P.; Wiseman, Mark A.; Luongo, Cesar; et al

    2015-06-01T23:59:59.000Z

    As part of the Jefferson Lab 12GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes the various failure modes in torus magnet along with the failure modes that could be experienced by the torus and its interaction with the solenoid which is located inmore »close proximity.« less

  12. Laminated photovoltaic modules using back-contact solar cells

    DOE Patents [OSTI]

    Gee, James M. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Morgan, William P. (Albuquerque, NM); Worobey, Walter (Albuquerque, NM)

    1999-09-14T23:59:59.000Z

    Photovoltaic modules which comprise back-contact solar cells, such as back-contact crystalline silicon solar cells, positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The module designs allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  13. Method of monolithic module assembly

    DOE Patents [OSTI]

    Gee, James M. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Morgan, William P. (Albuquerque, NM); Worobey, Walter (Albuquerque, NM)

    1999-01-01T23:59:59.000Z

    Methods for "monolithic module assembly" which translate many of the advantages of monolithic module construction of thin-film PV modules to wafered c-Si PV modules. Methods employ using back-contact solar cells positioned atop electrically conductive circuit elements affixed to a planar support so that a circuit capable of generating electric power is created. The modules are encapsulated using encapsulant materials such as EVA which are commonly used in photovoltaic module manufacture. The methods of the invention allow multiple cells to be electrically connected in a single encapsulation step rather than by sequential soldering which characterizes the currently used commercial practices.

  14. Short time scale thermal mechanical shock wave propagation in high performance microelectronic packaging configuration

    E-Print Network [OSTI]

    Nagaraj, Mahavir

    2004-11-15T23:59:59.000Z

    joint fatigue during the prototyping stage. Vandevelde et al. [2] conducted a parameter based thermomechanical modeling of Chip Scale Package (CSP) assemblies. Using parameters related to solder joint geometry, CSP dimensions and a fatigue... GPa Poisson Ration (? ) 0.22 Density (? ) 2330 kg/m3 Specific heat (cv) 700 J/kg?C Thermal conductivity (k) 155 W/m?C Expansion coefficient (? ) 2.3 ?? /?C It can be seen that the mechanical wave speed is essentially constant for t2 less...

  15. Electron tunneling studies of Mn12-Acetate

    E-Print Network [OSTI]

    Ma, Lianxi

    2008-10-10T23:59:59.000Z

    ]. . . . . . . . . . . . . . . . 24 10 Frame for rotating the tunneling wires in the PLD chamber during deposition. The two black posts are brass that were wrapped with shrink tubing so that the wires can be attached to them and still be insulated from one another. The two white... copper posts that are made from 0.010” diameter bare copper wires. The tunneling wires are first wrapped around the copper posts and then fixed in position with PbSn solder. Although silver print and silver epoxy have also been used to connect the wires...

  16. Ion detector

    DOE Patents [OSTI]

    Tullis, Andrew M. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    An improved ion detector device of the ionization detection device chamber ype comprises an ionization chamber having a central electrode therein surrounded by a cylindrical electrode member within the chamber with a collar frictionally fitted around at least one of the electrodes. The collar has electrical contact means carried in an annular groove in an inner bore of the collar to contact the outer surface of the electrode to provide electrical contact between an external terminal and the electrode without the need to solder leads to the electrode.

  17. Improved ion detector

    DOE Patents [OSTI]

    Tullis, A.M.

    1986-01-30T23:59:59.000Z

    An improved ion detector device of the ionization detection device chamber type comprises an ionization chamber having a central electrode therein surrounded by a cylindrical electrode member within the chamber with a collar frictionally fitted around at least one of the electrodes. The collar has electrical contact means carried in an annular groove in an inner bore of the collar to contact the outer surface of the electrode to provide electrical contact between an external terminal and the electrode without the need to solder leads to the electrode.

  18. GOMA 6.0 : a full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport : user%3CU%2B2019%3Es guide.

    SciTech Connect (OSTI)

    Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken Shuang; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew Morgan; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B. [3M Engineering Systems and Technology, St. Paul, MN] [3M Engineering Systems and Technology, St. Paul, MN

    2013-07-01T23:59:59.000Z

    Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a user's guide and reference.

  19. Design of a Probe for Strain Sensitivity Studies of Critical Current Densities in SC Wires and Tapes

    SciTech Connect (OSTI)

    Dhanaraj, N.; Barzi, E.; Turrioni, D.; Rusy, A.; Lombardo, V.; /Fermilab

    2011-07-01T23:59:59.000Z

    The design of a variable-temperature probe used to perform strain sensitivity measurements on LTS wires and HTS wires and tapes is described. The measurements are intended to be performed at liquid helium temperatures (4.2 K). The wire or tape to be measured is wound and soldered on to a helical spring device, which is fixed at one end and subjected to a torque at the free end. The design goal is to be able to achieve {+-} 0.8 % strain in the wire and tape. The probe is designed to carry a current of 2000A.

  20. Tin electroplating/stripping evaluation. Topical report

    SciTech Connect (OSTI)

    McHenry, M.R.

    1995-08-01T23:59:59.000Z

    An evaluation was conducted to determine possible replacement chemistries for electroplating and stripping of tin-lead. The driver for this project was two-fold. Our first goal dealt with hazardous waste reduction. It was desired to eliminate lead (a heavy metal) from the electroplating process and thiourea (a known carcinogen) from the stripping process. We also sought to reduce the cost of nonconformance (CONC) realized by this process in the form of rough plating, broken paths, poor solderability, and overetching. Three suppliers` tin chemistries were evaluated as replacements for electroplating and stripping of tin-lead. Based on preliminary testing, one chemistry was chosen, evaluated, and approved for production use.

  1. New method for sand control and well stimulation in unconsolidated dirty sands

    SciTech Connect (OSTI)

    Aslesen, K.S.; Short, C.J.; Terwilliger, P.L.

    1981-01-01T23:59:59.000Z

    A new technique, the Solder Glass sand consolidation well completion method, has been developed which allows unlimited drawdown and improves productivity in wells completed in unconsolidated formations containing shales and clays. This technique eliminates the problems of sand production and fines migration by artificially consolidating a volume of reservoir sand near the wellbore. The consolidation is resistant to high temperature, chemical attack, and degradation resulting from high velocity fluid flow. Additionally, porosity and permeability in the consolidated volume of reservoir sand are improved as a result of irreversible dehydration of clays. 12 refs.

  2. Packaging of solid state devices

    DOE Patents [OSTI]

    Glidden, Steven C.; Sanders, Howard D.

    2006-01-03T23:59:59.000Z

    A package for one or more solid state devices in a single module that allows for operation at high voltage, high current, or both high voltage and high current. Low thermal resistance between the solid state devices and an exterior of the package and matched coefficient of thermal expansion between the solid state devices and the materials used in packaging enables high power operation. The solid state devices are soldered between two layers of ceramic with metal traces that interconnect the devices and external contacts. This approach provides a simple method for assembling and encapsulating high power solid state devices.

  3. Direct cooled power electronics substrate

    DOE Patents [OSTI]

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W. (Kingston, TN) [Kingston, TN; Lowe, Kirk T. (Knoxville, TN) [Knoxville, TN

    2010-09-14T23:59:59.000Z

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  4. Repairable chip bonding/interconnect process

    DOE Patents [OSTI]

    Bernhardt, Anthony F. (Berkeley, CA); Contolini, Robert J. (Livermore, CA); Malba, Vincent (Livermore, CA); Riddle, Robert A. (Tracy, CA)

    1997-01-01T23:59:59.000Z

    A repairable, chip-to-board interconnect process which addresses cost and testability issues in the multi-chip modules. This process can be carried out using a chip-on-sacrificial-substrate technique, involving laser processing. This process avoids the curing/solvent evolution problems encountered in prior approaches, as well is resolving prior plating problems and the requirements for fillets. For repairable high speed chip-to-board connection, transmission lines can be formed on the sides of the chip from chip bond pads, ending in a gull wing at the bottom of the chip for subsequent solder.

  5. Repairable chip bonding/interconnect process

    DOE Patents [OSTI]

    Bernhardt, A.F.; Contolini, R.J.; Malba, V.; Riddle, R.A.

    1997-08-05T23:59:59.000Z

    A repairable, chip-to-board interconnect process which addresses cost and testability issues in the multi-chip modules is disclosed. This process can be carried out using a chip-on-sacrificial-substrate technique, involving laser processing. This process avoids the curing/solvent evolution problems encountered in prior approaches, as well is resolving prior plating problems and the requirements for fillets. For repairable high speed chip-to-board connection, transmission lines can be formed on the sides of the chip from chip bond pads, ending in a gull wing at the bottom of the chip for subsequent solder. 10 figs.

  6. Electromigration kinetics and critical current of Pb-free interconnects

    SciTech Connect (OSTI)

    Lu, Minhua; Rosenberg, Robert [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

    2014-04-07T23:59:59.000Z

    Electromigration kinetics of Pb-free solder bump interconnects have been studied using a single bump parameter sweep technique. By removing bump to bump variations in structure, texture, and composition, the single bump sweep technique has provided both activation energy and power exponents that reflect atomic migration and interface reactions with fewer samples, shorter stress time, and better statistics than standard failure testing procedures. Contact metallurgies based on Cu and Ni have been studied. Critical current, which corresponds to the Blech limit, was found to exist in the Ni metallurgy, but not in the Cu metallurgy. A temperature dependence of critical current was also observed.

  7. Au microstructure and the functional properties of Ni/Au finishes on ceramic IC packages

    SciTech Connect (OSTI)

    Winters, E.D.; Baxter, W.K. [Coors Electronic Package Co., Chattanooga, TN (United States); Braski, D.N.; Watkins, T.R. [Oak Ridge National Lab., TN (United States)

    1995-12-31T23:59:59.000Z

    Ni/Au plated finishes used on thick-film metallized multilayer ceramic packages for integrated circuits must meet functional requirements such as bondability, sealability, and solderability. Their ability to do so is dependent, among other things, on the ability of the Au deposit to inhibit the grain boundary diffusion and subsequent surface oxidation of Ni. In this study, the relation between functional performance, Ni diffusionr ate, and Au microstructure was examined. Extent of Ni diffusion during heating was determined by Auger electron spectroscopy for several electrolytic and electroless Ni/Au finishing processes. Results were correlated with differences in Au microstructures determined by SEM, atomic force microscopy, and XRD.

  8. Phase 2 of the array automated assembly task for the low cost silicon solar array project. Final report

    SciTech Connect (OSTI)

    Petersen, R.C.

    1980-11-01T23:59:59.000Z

    Studies were conducted on several fundamental aspects of electroless nickel/solder metallization for silicon solar cells. A process proposed by Motorola, which precedes the electroless nickel plating with several steps of palladium plating and heat treatment, was compared directly with single step electroless nickel plating. Work has directed toward answering specific questions concerning the effect of silicon surface oxide on nickel plating, effects of thermal stresses on the metallization, sintering of nickel plated on silicon, and effects of exposure to the plating solution on solar cell characteristics. The Motorola process was compared with simple electroless nickel plating in a series of parallel experiments. Results are presented. (WHK)

  9. Material compatibility and thermal aging of thermoelectric materials.

    SciTech Connect (OSTI)

    Gardea, Andrew D.; Nishimoto, Ryan; Yang, Nancy Y. C.; Morales, Alfredo Martin; Whalen, Scott A.; Chames, Jeffrey M.; Clift, W. Miles

    2009-09-01T23:59:59.000Z

    In order to design a thermoelectric (TE) module suitable for long-term elevated temperature use, the Department 8651 has conducted parametric experiments to study material compatibility and thermal aging of TE materials. In addition, a comprehensive material characterization has been preformed to examine thermal stability of P- and N-based alloys and their interaction with interconnect diffusion barrier(s) and solder. At present, we have completed the 7-days aging experiments for 36 tiles, from ambient to 250 C. The thermal behavior of P- and N-based alloys and their thermal interaction with both Ni and Co diffusion barriers and Au-Sn solder were examined. The preliminary results show the microstructure, texture, alloy composition, and hardness of P-(Bi,Sb){sub 2}Te{sub 3} and N-Bi{sub 2}(Te,Se){sub 3} alloys are thermally stable up to 7 days annealing at 250 C. However, metallurgical reactions between the Ni-phosphor barriers and P-type base alloy were evident at temperatures {ge} 175 C. At 250 C, the depth (or distance) of the metallurgical reaction and/or Ni diffusion into P-(Bi,Sb){sub 2}Te{sub 3} is approximately 10-15 {micro}m. This thermal instability makes the Ni-phosphor barrier unsuitable for use at temperatures {ge} 175 C. The Co barrier appeared to be thermally stable and compatible with P(Bi,Sb){sub 2}Te{sub 3} at all annealing temperatures, with the exception of a minor Co diffusion into Au-Sn solder at {ge} 175 C. The effects of Co diffusion on long-term system reliability and/or the thermal stability of the Co barrier are yet to be determined. Te evaporation and its subsequent reaction with Au-Sn solder and Ni and Co barriers on the ends of the tiles at temperatures {ge} 175 C were evident. The Te loss and its effect on the long-term required stoichiometry of P-(Bi, Sb){sub 2}Te{sub 3} are yet to be understood. The aging experiments of 90 days and 180 days are ongoing and scheduled to be completed in 30 days and 150 days, respectively. Material characterization activities are continuing for the remaining tiles.

  10. Microstructural development and mechanical behavior of eutectic bismuth-tin and eutectic indium-tin in response to high temperature deformation

    SciTech Connect (OSTI)

    Goldstein, J.L.F. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; [Lawrence Berkeley Lab., CA (United States)

    1993-11-01T23:59:59.000Z

    The mechanical behavior and microstructure of eutectic Bi-Sn and In-Sn solders were studied in parallel in order to better understand high temperature deformation of these alloys. Bi-Sn solder joints were made with Cu substrates, and In-Sn joints were made with either Cu or Ni substrates. The as-cast microstructure of Bi-Sn is complex regular, with the two eutectic phases interconnected in complicated patterns. The as-cast microstructure of In-Sn depends on the substrate. In-Sn on Cu has a non-uniform microstructure caused by diffusion of Cu into the solder during sample preparation, with regions of the Sn-rich {gamma} phase imbedded in a matrix of the In-rich {beta} phase. The microstructure of In-Sn on Ni is uniform and lamellar and the two phases are strongly coupled. The solders deform non-uniformly, with deformation concentrating in a band along the length of the sample for Bi-Sn and In-Sn on Cu, though the deformation is more diffuse in In-Sn than in Bi-Sn. Deformation of In-Sn on Ni spreads throughout the width of the joint. The different deformation patterns affect the shape of the stress-strain curves. Stress-strain curves for Bi-Sn and In-Sn on Cu exhibit sharp decays in the engineering stress after reaching a peak. Most of this stress decay is removed for In-Sn on Ni. The creep behavior of In-Sn also depends on the substrate, with the creep deformation controlled by the soft P phase of the eutectic for In-Sn on Cu and controlled by the harder {gamma} phase for In-Sn on Ni. When In-Sn on Ni samples are aged, the microstructure coarsens and changes to an array of {gamma} phase regions in a matrix of the {beta} phase, and the creep behavior changes to resemble that of In-Sn on Cu. The creep behavior of Bi-Sn changes with temperature. Two independent mechanisms operate at lower temperatures, but there is still some question as to whether one or both of these, or a third mechanism, operates at higher temperatures.

  11. An apparatus for the measurement of thermal conductivity of liquid neon

    E-Print Network [OSTI]

    Jensen, Jerald Norman

    1967-01-01T23:59:59.000Z

    past the max1mum recommended storage temperature of 100 C. The hot plate, Pl, and guard ring, P2, are heated. by nicrome heater wires, whose respective resistances are 50 ohms and. 150 ohms. An additional heater of 5 ohms was placed near the cupro-nickel.... to the heater. They were coiled around the top of the guard. ring once before being soldered to the number 36 copper wires leading to the top plate. The number 36 wires go to the top plate by means of a 1/8 in. cupro-nickel tube and were sealed from...

  12. Tinning/Trimming Robot System

    SciTech Connect (OSTI)

    Fureigh, M.L.

    1993-02-01T23:59:59.000Z

    In a new surface mount assembly area at AlliedSignal Inc., Kansas City Division (KCD), a tinning/trimming robot system tins and trims the gold-plated leads of surface mount technology (SMT) transistors. The KCD-designed system uses a Unimation PUMA 260 robot, a General Production Devices SP-2000 solder pot; water-soluble Blackstone No. 2508 flux; and a Virtual Industries high-temperature, ESD-conductive, miniature suction cup. After the manual cleaning operation, the processed SMT transistors go to the QUADSTAR Automated Component Placement System for a Radar Logic Assembly. The benefits are reductions in the cost of nonconformance, worker fatigue, and standard hours.

  13. Programmable Multi-Chip Module

    SciTech Connect (OSTI)

    Kautz, David (Lenexa, KS); Morgenstern, Howard (Lee's Summit, MO); Blazek, Roy J. (Overland Park, KS)

    2005-05-24T23:59:59.000Z

    A multi-chip module comprising a low-temperature co-fired ceramic substrate having a first side on which are mounted active components and a second side on which are mounted passive components, wherein this segregation of components allows for hermetically sealing the active components with a cover while leaving accessible the passive components, and wherein the passive components are secured using a reflow soldering technique and are removable and replaceable so as to make the multi-chip module substantially programmable with regard to the passive components.

  14. Programmable multi-chip module

    SciTech Connect (OSTI)

    Kautz, David; Morgenstern, Howard; Blazek, Roy J.

    2004-03-02T23:59:59.000Z

    A multi-chip module comprising a low-temperature co-fired ceramic substrate having a first side on which are mounted active components and a second side on which are mounted passive components, wherein this segregation of components allows for hermetically sealing the active components with a cover while leaving accessible the passive components, and wherein the passive components are secured using a reflow soldering technique and are removable and replaceable so as to make the multi-chip module substantially programmable with regard to the passive components.

  15. Programmable Multi-Chip Module

    DOE Patents [OSTI]

    Kautz, David (Lenexa, KS); Morgenstern, Howard (Lee's Summit, MO); Blazek, Roy J. (Overland Park, KS)

    2004-11-16T23:59:59.000Z

    A multi-chip module comprising a low-temperature co-fired ceramic substrate having a first side on which are mounted active components and a second side on which are mounted passive components, wherein this segregation of components allows for hermetically sealing the active components with a cover while leaving accessible the passive components, and wherein the passive components are secured using a reflow soldering technique and are removable and replaceable so as to make the multi-chip module substantially programmable with regard to the passive components.

  16. Solving Water Quality Problems in the Home 

    E-Print Network [OSTI]

    Dozier, Monty; McFarland, Mark L.

    2004-02-20T23:59:59.000Z

    unnecessary. Private well water should be tested at least every 2 years for coliform bacteria and nitrates. Also test for lead if the house is old and contains iron or copper pipes, fittings, plumbing fixtures or solder. Other contaminants need to be measured... Reddish-brown slime Iron bacteria Off-color appearance: Cloudy Turbidity Black Hydrogen sulfide, manganese Brown or yellow Iron, tannic acid Unusual taste and odor: Rotten egg Hydrogen sulfide Metallic pH, corrosive index, iron, zinc, copper, lead Septic...

  17. Method for measuring lead concentrations in blood

    DOE Patents [OSTI]

    Nogar, Nicholas S. (Los Alamos, NM)

    2001-01-01T23:59:59.000Z

    Method for measuring lead concentrations in blood. The present invention includes the use of resonant laser ablation to analyze .ltoreq.1 .mu.L (or equivalent mass) samples of blood for lead content. A typical finger prick, for example, yields about 10 .mu.L. Solid samples may also readily be analyzed by resonant laser ablation. The sample is placed on a lead-free, electrically conducting substrate and irradiated with a single, focused laser beam which simultaneously vaporizes, atomizes, and resonantly ionizes an analyte of interest in a sample. The ions are then sorted, collected and detected using a mass spectrometer.

  18. Lab Community Mourns Death of Retired Engineering Division Technician,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-free

  19. Lab Director focuses on STEM education at TEDxABQ

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-freeDirector

  20. Lab Equipment & Capability | Photosynthetic Antenna Research Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 - -/e),,s - 16,3/14SecurityLead-freeDirectorLab

  1. Micromechanical die attachment surcharge

    DOE Patents [OSTI]

    Filter, William F. (Albuquerque, NM); Hohimer, John P. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    An attachment structure is disclosed for attaching a die to a supporting substrate without the use of adhesives or solder. The attachment structure, which can be formed by micromachining, functions purely mechanically in utilizing a plurality of shaped pillars (e.g. round, square or polygonal and solid, hollow or slotted) that are formed on one of the die or supporting substrate and which can be urged into contact with various types of mating structures including other pillars, a deformable layer or a plurality of receptacles that are formed on the other of the die or supporting substrate, thereby forming a friction bond that holds the die to the supporting substrate. The attachment structure can further include an alignment structure for precise positioning of the die and supporting substrate to facilitate mounting the die to the supporting substrate. The attachment structure has applications for mounting semiconductor die containing a microelectromechanical (MEM) device, a microsensor or an integrated circuit (IC), and can be used to form a multichip module. The attachment structure is particularly useful for mounting die containing released MEM devices since these devices are fragile and can otherwise be damaged or degraded by adhesive or solder mounting.

  2. DESIGN, FABRICATION AND TEST OF THE REACT AND WIND, NB(3)SN, LDX FLOATING COIL CONDUCTOR.

    SciTech Connect (OSTI)

    SMITH,B.A.; MICHAEL,P.C.; MINERVINI,J.V.; TAKAYASU,M.; SCHULTZ,J.H.; GREGORY,E.; PYON,T.; SAMPSON,W.B.; GHOSH,A.; SCANLAN,R.

    2000-09-17T23:59:59.000Z

    The Levitated Dipole Experiment (LDX) is a novel approach for studying magnetic confinement of a fusion plasma. In this approach, a superconducting ring coil is magnetically levitated for up to 8 hours a day in the center of a 5 meter diameter vacuum vessel. The levitated coil, with on-board helium supply, is called the gloating Coil (F-Coil). Although the maximum field at the coil is only 5.3 tesla, a react-and-wind Nb{sub 3}Sn conductor was selected because the relatively high critical temperature will enable the coil to remain levitated while it warms from 5 K to 10 K. Since pre-reacted Nb{sub 3}Sn tape is no longer commercially available, a composite conductor was designed that contains an 18 strand Nb{sub 3}Sn Rutherford cable. The cable was reacted and then soldered into a structural copper channel that completes the conductor and also provides quench protection. The strain state of the cable was continuously controlled during fabrication steps such as: soldering into the copper channel, spooling, and coil winding, to prevent degradation of the critical current. Measurements of strand and cable critical currents are reported, as well as estimates of the effect of fabrication, winding and operating strains on critical current.

  3. Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.

    SciTech Connect (OSTI)

    Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

    2012-01-01T23:59:59.000Z

    Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

  4. Process research on Semix Silicon Material (PROSSM). Quarterly report No. 5, December 1, 1981-February 28, 1982

    SciTech Connect (OSTI)

    Wohlgemuth, J H; Warfield, D B

    1982-01-01T23:59:59.000Z

    Emphasis was shifted from the development of a cost-effective process sequence to research designed to understand the mechanisms of photovoltaic conversion in semicrystalline silicon. With this change has gone a change of title from Module Experimental Process System Development Unit (MEPSDU) to Process Research of Semix Silicon Material (PROSSM). Efforts are now underway to prepare a revised program plan with emphasis on determining the mechanisms limiting voltage and current collection in the semicrystalline silicon. The efforts reported concern work done before the change in emphasis and so the continued development of the cost-effective process sequence is reported. A cost-effective process sequence was identified, equipment was designed to implement a 6.6 MW per year automated production line, and a cost analysis projected a $0.56 per watt cell add-on cost for this line. Four process steps were developed for this program: glass bead back clean-up; hot spray antireflective coating; wave-soldering of fronts; ion milling for edging. While spray dopants were advertised as an off the shelf developed product, they proved to be unreliable with shorter than advertised shelf life. Equipment for handling and processing solar cells is available for all of the cell processing steps identified in this program. During this quarter efforts included work on spray dopant, edging, AR coating, wave soldering and fluxing, ion milling and cost analysis.

  5. Experimental studies of helical solenoid model based on YBCO tape-bridge joints

    SciTech Connect (OSTI)

    Yu, M.; Lombardo, V.; Turrioni, D.; Zlobin, A.V.; /Fermilab; Flangan, G.; /MUONS Inc., Batavia; Lopes, M.L.; /Fermilab; Johnson, R.P.; /Fermilab

    2011-06-01T23:59:59.000Z

    Helical solenoids that provide solenoid, helical dipole and helical gradient field components are designed for a helical cooling channel (HCC) proposed for cooling of muon beams in a muon collider. The high temperature superconductor (HTS), 12 mm wide and 0.1 mm thick YBCO tape, is used as the conductor for the highest-field section of HCC due to certain advantages, such as its electrical and mechanical properties. To study and address the design, and technological and performance issues related to magnets based on YBCO tapes, a short helical solenoid model based on double-pancake coils was designed, fabricated and tested at Fermilab. Splicing joints were made with Sn-Pb solder as the power leads and the connection between coils, which is the most critical element in the magnet that can limit the performance significantly. This paper summarizes the test results of YBCO tape and double-pancake coils in liquid nitrogen and liquid helium, and then focuses on the study of YBCO splices, including the soldering temperatures and pressures, and splice bending test.

  6. Corrosion inhibitors in the electronic industry

    SciTech Connect (OSTI)

    Brusic, V. [IBM, Yorktown Heights, NY (United States). Thomas J. Watson Research Center

    1996-12-01T23:59:59.000Z

    The most widely used inhibitors in the electronics industry are chromates, phosphates, and silicates in chip processing and azoles in printed circuit board (PCB) fabrication. Azoles are the principal constituents of Organic Solderability Preservatives (OSPS) used on bare copper that could replace Hot Air Solder Leveling (HASL). For years HASL has been the most prevalent surface finishing process in PCB fabrication. This process is currently under scrutiny, because of safety and environment concerns (lead exposure, waste disposal), process limitations (stress, extendibility to fine-pitch device assembly), and cost. The use of azoles is a cost-effective solution to these concerns but it is also a source of new ones. Aside from being typical corrosion inhibitors, the azoles are expected to provide protection to a copper surface against thermal oxidation yet at higher temperatures inhibitors themselves are not stable. The challenge of bringing azoles to PCB manufacture has resulted in close interaction of the board shop, assembly customer, and the OSP chemistry suppliers. This paper is an overview of the relevant work in which a compromise between process demands and achievable inhibitor performance is discussed.

  7. Printed wiring board fabrication and lead elimination via single-bath electrodeposition

    SciTech Connect (OSTI)

    Meltzer, M P; Steffani, C P

    2001-02-21T23:59:59.000Z

    Printed wiring board (PWB) fabrication, an operation performed both at LLNL and throughout the electronics industry, generates considerable quantities of hazardous waste, notably lead-bearing materials used for soldering, tinning, and finish coating the circuits of the board. Hot-air solder leveling (HASL), the most common method of finishing is one of the main sources of hazardous lead-bearing wastes in traditional PWB manufacturing. The development of a safer finishing method will lead to employee health and environmental benefits. In addition, there is a production advantage to eliminating HASL, for it provides a fairly uneven surface that is problematic for mounting very small components. In this project, we developed ''single-bath electroplating'' as a potential HASL replacement technology for many applications. Single-bath electroplating involves alternating deposition of one or the other metal component of a bimetal bath, through control of plating potential and mass transport. It employs a nickel layer as both etch resist and finish coat and has the potential for lowering environmental and human-health risks associated with PWB manufacture--while at the same time reconfiguring the process for greater efficiency and profitability.

  8. Twenty years of service at NBNM - Analysis of Spectrolab module

    SciTech Connect (OSTI)

    DHERE,N.G.; PANDIT,M.B.; GHONGADI,S.R.; QUINTANA,MICHAEL A.; KING,DAVID L.; KRATOCHVIL,JAY A.

    2000-04-11T23:59:59.000Z

    This study of adhesional strength and surface analysis of encapsulant and silicon cell samples from a Natural Bridges National Monument (NBNM) Spectrolab module is an attempt to understand from its success. The module was fabricated using polyvinyl butyral (PVB) as an encapsulant. The average adhesional shear strength of the encapsulant at the cell/encapsulant interface in this module was 4.51 MPa or {approximately} 18% lower than that in currently manufactured modules. Typical encapsulant surface composition was as follows: C 75.0 at.% O 23.2 at.%, and Si 1.6 at.%, with Ag {approximately}0.2 at.% and Pb {approximately} 0.5 at.% with some tin respectively over the grid lines and solder bond. Representative silicon cell surface composition was: K 1.4 at.%, C 20.8 at.%, Sn 0.94 at.%, O 15.1 at.%, Na 2.7 at.% and Si 59.0 at.%. The presence of tin detected on the silicon cell surface may be attributed to corrosion of solder bond. The module differs from typical contemporary modules in the use of PVB, metallic mesh type interconnection, and silicon oxide AR coating.

  9. Development of a Fluxless Flip Chip Bonding Process for Optical Military Electronics

    SciTech Connect (OSTI)

    Girardi, Michael

    2007-11-11T23:59:59.000Z

    As military electronics tend to become lighter, smaller, thinner, and lower cost, the use of flip chip technology is becoming more common place to meet system requirements, yet survive environments. This paper explores the development of an optical flip chip application and details the selection/qualification of the substrate. The selected assembly consists of a procured 1x12 Vertical Cavity Surface Emitting Laser (VCSEL) die, having 80um diameter eutectic AuSn solder bumps at 250um pitch and flip chip bonded to a .006” thick 99.6% alumina substrate with .006” diameter thru holes and metallized with 500Å WTi, under minimum 2.0-3.0?m (80-120?”) thin film deposited Au. An 8 run, 3 factor, 2 level Full Factorial Design of Experiments (DOE) was completed on procured detector arrays and procured ceramic substrates using the Suss Microtec FC150. The optimum settings for the peak temperature, peak time and final die z-height were selected using the ANOVA results and interaction plots. Additional studies were completed to qualify in-house produced substrates. An epoxy glob-top encapsulant was selected to dissipate stress on the flip chip solder joints and to enhance thermal shock performance.

  10. Ferroelectric and ferromagnetic properties in BaTiO{sub 3} thin films on Si (100)

    SciTech Connect (OSTI)

    Singamaneni, Srinivasa Rao, E-mail: ssingam@ncsu.edu; Prater, John T. [Materials Science Division, Army Research Office, Research Triangle Park, North Carolina 27709 (United States); Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Punugupati, Sandhyarani; Hunte, Frank; Narayan, Jagdish [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-09-07T23:59:59.000Z

    In this paper, we report on the epitaxial integration of room temperature lead-free ferroelectric BaTiO{sub 3} thin (?1050?nm) films on Si (100) substrates by pulsed laser deposition technique through a domain matching epitaxy paradigm. We employed MgO and TiN as buffer layers to create BaTiO{sub 3}/SrRuO{sub 3}/MgO/TiN/Si (100) heterostructures. C-axis oriented and cube-on-cube epitaxial BaTiO{sub 3} is formed on Si (100) as evidenced by the in-plane and out-of-plane x-ray diffraction, and transmission electron microscopy. X-ray photoemission spectroscopic measurements show that Ti is in 4(+) state. Polarization hysteresis measurements together with Raman spectroscopy and temperature-dependent x-ray diffraction confirm the room temperature ferroelectric nature of BaTiO{sub 3}. Furthermore, laser irradiation of BaTiO{sub 3} thin film is found to induce ferromagnetic-like behavior but affects adversely the ferroelectric characteristics. Laser irradiation induced ferromagnetic properties seem to originate from the creation of oxygen vacancies, whereas the pristine BaTiO{sub 3} shows diamagnetic behavior, as expected. This work has opened up the route for the integration of room temperature lead-free ferroelectric functional oxides on a silicon platform.

  11. Fan-fold shielded electrical leads

    DOE Patents [OSTI]

    Rohatgi, R.R.; Cowan, T.E.

    1996-06-11T23:59:59.000Z

    Disclosed are fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate. 3 figs.

  12. Method for fabricating fan-fold shielded electrical leads

    DOE Patents [OSTI]

    Rohatgi, R.R.; Cowan, T.E.

    1994-12-27T23:59:59.000Z

    Fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate. 3 figures.

  13. Low thermal resistance power module assembly

    DOE Patents [OSTI]

    Hassani, Vahab (Denver, CO); Vlahinos, Andreas (Castle Rock, CO); Bharathan, Desikan (Arvada, CO)

    2007-03-13T23:59:59.000Z

    A power module assembly with low thermal resistance and enhanced heat dissipation to a cooling medium. The assembly includes a heat sink or spreader plate with passageways or openings for coolant that extend through the plate from a lower surface to an upper surface. A circuit substrate is provided and positioned on the spreader plate to cover the coolant passageways. The circuit substrate includes a bonding layer configured to extend about the periphery of each of the coolant passageways and is made up of a substantially nonporous material. The bonding layer may be solder material which bonds to the upper surface of the plate to provide a continuous seal around the upper edge of each opening in the plate. The assembly includes power modules mounted on the circuit substrate on a surface opposite the bonding layer. The power modules are positioned over or proximal to the coolant passageways.

  14. Tests of prototype salt stripper system for IFR fuel cycle

    SciTech Connect (OSTI)

    Carls, E.L.; Blaskovitz, R.J.; Johnson, T.R. [Argonne National Lab., IL (United States); Ogata, T. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1993-09-01T23:59:59.000Z

    One of the waste treatment steps for the on-site reprocessing of spent fuel from the Integral Fast Reactor fuel cycles is stripping of the electrolyte salt used in the electrorefining process. This involves the chemical reduction of the actinides and rare earth chlorides forming metals which then dissolve in a cadmium pool. To develop the equipment for this step, a prototype salt stripper system has been installed in an engineering scale argon-filled glovebox. Pumping trails were successful in transferring 90 kg of LiCl-KCl salt containing uranium and rare earth metal chlorides at 500{degree}C from an electrorefiner to the stripper vessel at a pumping rate of about 5 L/min. The freeze seal solder connectors which were used to join sections of the pump and transfer line performed well. Stripping tests have commenced employing an inverted cup charging device to introduce a Cd-15 wt % Li alloy reductant to the stripper vessel.

  15. Electric lamp, base for use therewith and method of assembling same

    DOE Patents [OSTI]

    Hough, Harold L. (Beverly, MA); English, George J. (Reading, MA); Chakrabarti, Kirti B. (Danvers, MA)

    1989-02-14T23:59:59.000Z

    An electric lamp including a reflector, at least one conductive ferrule located within a surface of the reflector and a lead-in conductor electrically connected to the ferrule and extending within the reflector. The lamp includes a base having an insulative (e.g., ceramic) cap located substantially about the ferrule, barrier means (e.g., ceramic fiber) located within the cap to define an open chamber substantially about the ferrule, an electrical conductor (e.g., wire) extending within the cap and electrically connected (e.g., silver soldered) to the ferrule, and sealing means (e.g., high temperature cement) located within the cap to provide a seal therefore. The barrier means serves to separate the sealing means from the open chamber about the ferrule such that the heat generated by the ferrule can be vented through spaced apertures located within the cap's side wall. A method of assembling a base on an electric lamp is also provided.

  16. Relative Lifetime Prediction for CPV Die-Attach Layers: Preprint

    SciTech Connect (OSTI)

    Silverman, T. J.; Bosco, N.; Kurtz, S.

    2012-03-01T23:59:59.000Z

    In concentrating photovoltaics (CPV) cell assemblies, a large-area die-attach layer is subjected to thermal cycles, leading to thermomechanical fatigue. This causes cracking and the eventual failure of the CPV cell by thermal runaway. We define a damage metric representing lumped progress toward failure and present a numerical model for computing the accumulation of damage for arbitrary transient temperature conditions. The model is applied to a particular design with a solder die-attach layer. We show that accelerated-test thermal cycles with higher ramp rates cause more damage, both per cycle and per unit time. Outdoor exposure to one entire year in two geographic locations is also simulated, revealing that a year of exposure in Golden, Colorado is equivalent to 1.4 years of exposure in Oak Ridge, Tennessee.

  17. Release Resistant Electrical Interconnections For Mems Devices

    DOE Patents [OSTI]

    Peterson, Kenneth A. (Albuquerque, NM); Garrett, Stephen E. (Albuquerque, NM); Reber, Cathleen A. (Corrales, NM)

    2005-02-22T23:59:59.000Z

    A release resistant electrical interconnection comprising a gold-based electrical conductor compression bonded directly to a highly-doped polysilicon bonding pad in a MEMS, IMEMS, or MOEMS device, without using any intermediate layers of aluminum, titanium, solder, or conductive adhesive disposed in-between the conductor and polysilicon pad. After the initial compression bond has been formed, subsequent heat treatment of the joint above 363 C creates a liquid eutectic phase at the bondline comprising gold plus approximately 3 wt % silicon, which, upon re-solidification, significantly improves the bond strength by reforming and enhancing the initial bond. This type of electrical interconnection is resistant to chemical attack from acids used for releasing MEMS elements (HF, HCL), thereby enabling the use of a "package-first, release-second" sequence for fabricating MEMS devices. Likewise, the bond strength of an Au--Ge compression bond may be increased by forming a transient liquid eutectic phase comprising Au-12 wt % Ge.

  18. Losses in 23 strands NbTi and Nb/sub 3/Sn flat cables

    SciTech Connect (OSTI)

    Polak, M.; Krempasky, L.; Hlasnik, I.; Perot, J.

    1981-09-01T23:59:59.000Z

    Losses in different samples made of 23 strands multifilamentary NbTi and Nb/sub 3/Sn Rutherford type superconducting cables in pulsed magnetic fields were measured using the magnetization technique. Two technologies were used for sample preparation. One reason for this was to simulate the different winding structure of the pulsed magnets. Another reason was to obtain the samples with different average transverse resistivity across the unsoldered cable. For comparison, one sample, having a low average transverse resistivity, was made of the soldered cable. The influence of the cable pieces length, used for samples, on the rate dependent losses is demonstrated. Problems concerning the measurement of the time constant of the rate dependent magnetization are discussed. 4 refs.

  19. Capillary test specimen, system, and methods for in-situ visualization of capillary flow and fillet formation

    DOE Patents [OSTI]

    Hall, Aaron C. (Albuquerque, NM); Hosking, F. Michael (Albuquerque, NM),; Reece, Mark (Albuquerque, NM)

    2003-06-24T23:59:59.000Z

    A capillary test specimen, method, and system for visualizing and quantifying capillary flow of liquids under realistic conditions, including polymer underfilling, injection molding, soldering, brazing, and casting. The capillary test specimen simulates complex joint geometries and has an open cross-section to permit easy visual access from the side. A high-speed, high-magnification camera system records the location and shape of the moving liquid front in real-time, in-situ as it flows out of a source cavity, through an open capillary channel between two surfaces having a controlled capillary gap, and into an open fillet cavity, where it subsequently forms a fillet on free surfaces that have been configured to simulate realistic joint geometries. Electric resistance heating rapidly heats the test specimen, without using a furnace. Image-processing software analyzes the recorded images and calculates the velocity of the moving liquid front, fillet contact angles, and shape of the fillet's meniscus, among other parameters.

  20. Characterization of printing and laser trimming of DuPont 2000 series resistors on DuPont 951 {open_quotes}Green Tape{trademark}{close_quotes}

    SciTech Connect (OSTI)

    Morgenstern, H.; Bandler, S.; Barner, G.

    1996-10-01T23:59:59.000Z

    DuPont 2000 series resistors were reviewed and found to come closest to our requirement of 1% resistor tolerance over the expected 30-year life of our products. The evaluation performed involved the characterization of both the printing and trimming processes. The printing process was characterized for firing temperature print thickness, print direction, resistor geometry and encapsulant effect. Laser trimming was characterized by first finding an operating envelope and then selecting an operating point. The envelope was located by varying the trimming parameters and determining their acceptability to electrical and visual criteria. Samples from both the envelope and operating point were environmentally conditioned The conditioning included thermal shock temperature cycle, 1000-hour temperature aging, 1000-hour humidity aging, and a simulated gold/tin solder reflow.

  1. Dr. John J. Stephens, Jr., metallurgist extraordinaire.

    SciTech Connect (OSTI)

    Hosking, Floyd Michael

    2010-10-01T23:59:59.000Z

    The organizers of the Dr. John J. Stephens, Jr. Memorial Symposium: Deformation and Interfacial Phenomena in Advanced High-Temperature Materials are honoring the memory of Dr. Stephens and his many technical contributions that were accomplished over a relatively brief twenty year career. His research spanned the areas of creep and deformation of metals, dispersion-strengthened alloys and their properties, metal matrix composite materials, processing and properties of refractory metals, joining of ceramic-ceramic and metal-ceramic systems, active braze alloy development, and mechanical modeling of soldered and brazed assemblies. The purpose of this presentation is to highlight his research and engineering accomplishments, particularly during his professional career at Sandia National Laboratories in Albuquerque, NM.

  2. Thin-film chip-to-substrate interconnect and methods for making same

    DOE Patents [OSTI]

    Tuckerman, D.B.

    1988-06-06T23:59:59.000Z

    Integrated circuit chips are electrically connected to a silicon wafer interconnection substrate. Thin film wiring is fabricated down bevelled edges of the chips. A subtractive wire fabrication method uses a series of masks and etching steps to form wires in a metal layer. An additive method direct laser writes or deposits very thin lines which can then be plated up to form wires. A quasi-additive or subtractive/additive method forms a pattern of trenches to expose a metal surface which can nucleate subsequent electrolytic deposition of wires. Low inductance interconnections on a 25 micron pitch (1600 wires on a 1 cm square chip) can be produced. The thin film hybrid interconnect eliminates solder joints or welds, and minimizes the levels of metallization. Advantages include good electrical properties, very high wiring density, excellent backside contact, compactness, and high thermal and mechanical reliability. 6 figs.

  3. Automated solar cell assembly teamed process research. Semiannual subcontract report, 7 January 1993--30 June 1993

    SciTech Connect (OSTI)

    Nowlan, M.J.; Hogan, S.J.; Darkazalli, G.; Breen, W.F.; Murach, J.M.; Sutherland, S.F. [Spire Corp., Bedford, MA (United States)

    1994-02-01T23:59:59.000Z

    This report describes work done under Phase 3A of the PVMaT project to address problems that are generic to the photovoltaics (PV) industry. Crystalline silicon solar cells were used in the majority of all terrestrial power modules shipped in 1992. Spire`s analysis in Phase 1 of the PVMaT project indicated that the use of thin ({le}200-{mu}m) silicon cells can substantially reduce module manufacturing costs, provided that processing yields remain as high as they are now for processing standard thickness cells. Because present solar cell tabbing and interconnecting processes have unacceptably high yield losses with such thin cells, the objective of this Phase 3A subcontract is to use Spire`s light soldering technology and experience in designing and fabricating solar cell tabbing and interconnecting equipment to develop high yield throughput, fully automated processes for tabbing and interconnecting thin cells.

  4. Electrochemical Approaches to PV Busbar Application

    SciTech Connect (OSTI)

    Pankow, J. W.

    2005-01-01T23:59:59.000Z

    Busbars are an integral component of any thin-film photovoltaic module and must be easy and quick to apply by PV manufacturers, as well as provide long-term reliability in deployed modules. Potential reliability issues include loss of adhesion and delamination, chemical instability under current collection conditions (electromigration or corrosion), compatibility of material and application method with subsequent encapsulation steps. Several new and novel busbar materials and application methods have been explored, including adhering metal busbars with various one- and two-part conductive epoxies or conductive adhesive films, ultrasonic bonding of metal busbar strips, and bonding of busbar strips using low-temperature solders. The most promising approach to date has been the direct application of metal busbars via various electrochemical techniques, which offers a variety of distinct advantages.

  5. Evaluation of a 6-wire thermocouple psychrometer for determination of in-situ water potentials

    SciTech Connect (OSTI)

    Loskot, C.L.; Rousseau, J.P. [Geological Survey, Denver, CO (United States); Kurzmack, M.A. [Foothill Engineering Consultants, Golden, CO (United States)

    1994-12-31T23:59:59.000Z

    A 6-wire, Peltier-type thermocouple psychrometer was designed and evaluated by the U.S. Geological Survey for monitoring in-situ water potentials in dry-drilled boreholes in the unsaturated zone at Yucca Mountain, Nye County, Nevada. The psychrometer consists of a wet-bulb, chromel-constantan, sensing junction and a separate dry-bulb, copper-constantan, reference junction. Two additional reference junctions are formed where the chromel and constantan wires of the wet-bulb sensing junction are soldered to separate, paired, copper, lead wires. In contrast, in the standard 3-wire thermocouple psychrometer, both the wet bulb and dry bulb share a common wire. The new design has resulted in a psychrometer that has an expanded range and greater reliability, sensitivity, and accuracy compared to the standard model.

  6. Feed mechanism and method for feeding minute items

    DOE Patents [OSTI]

    Stringer, Timothy Kent; Yerganian, Simon Scott

    2012-11-06T23:59:59.000Z

    A feeding mechanism and method for feeding minute items, such as capacitors, resistors, or solder preforms. The mechanism is adapted to receive a plurality of the randomly-positioned and randomly-oriented extremely small or minute items, and to isolate, orient, and position the items in a specific repeatable pickup location wherefrom they may be removed for use by, for example, a computer-controlled automated assembly machine. The mechanism comprises a sliding shelf adapted to receive and support the items; a wiper arm adapted to achieve a single even layer of the items; and a pushing arm adapted to push the items into the pickup location. The mechanism can be adapted for providing the items with a more exact orientation, and can also be adapted for use in a liquid environment.

  7. Feed mechanism and method for feeding minute items

    SciTech Connect (OSTI)

    Stringer, Timothy Kent (Bucyrus, KS); Yerganian, Simon Scott (Lee's Summit, MO)

    2009-10-20T23:59:59.000Z

    A feeding mechanism and method for feeding minute items, such as capacitors, resistors, or solder preforms. The mechanism is adapted to receive a plurality of the randomly-positioned and randomly-oriented extremely small or minute items, and to isolate, orient, and position one or more of the items in a specific repeatable pickup location wherefrom they may be removed for use by, for example, a computer-controlled automated assembly machine. The mechanism comprises a sliding shelf adapted to receive and support the items; a wiper arm adapted to achieve a single even layer of the items; and a pushing arm adapted to push the items into the pickup location. The mechanism can be adapted for providing the items with a more exact orientation, and can also be adapted for use in a liquid environment.

  8. The Electrical Resistance of Rutherford-Type Superconducting Cable Splices

    E-Print Network [OSTI]

    Heck, C; Fleiter, J; Bottura, L

    2015-01-01T23:59:59.000Z

    The electrical resistance of Large Hadron Collider main busbar cable lap splices produced by soft soldering has been measured with two independent methods as a function of intercable contact area and for splices made of cables with various defects. For defect-free lap splices, the resistance increases from 0.3 to 10 n? (at 4.3 K in self-field) when reducing the cable overlap length from 120 to 3 mm, as expected assuming that the resistance is inversely proportional to the intercable contact area. The resistance of bridge splices that connect side-by-side cables can be predicted from the lap splice resistances and the overlap areas involved.

  9. ES&H development activities for the W89 warhead

    SciTech Connect (OSTI)

    Pretzel, C.W.

    1995-08-01T23:59:59.000Z

    Environmental, Safety and Health (ES&H) issues became an important design consideration during the development of the W89 warhead for the SRAM 11 (Short-Range Attack Missile) missile. An action plan was developed to handle these issues at all the production agencies and at both the system and the component level. The main thrust was in the area of solvent substitution, in particular for solder flux removal. The cleaner d-limonene followed by an isopropyl alcohol rinse was selected for applications were the traditional cleaners were 1,1,1 trichloroethane or trichloroethylene. Compatibility testing rather than efficacy testing dominated the development effort. In addition to other solvent substitution applications, organic materials that were free of toluene diisocynate (TDI), and methylene dianiline (MDA) were explored for use in the W89.

  10. On quantum and parallel transport in a Hilbert bundle over spacetime

    E-Print Network [OSTI]

    W. Drechsler; Philip A. Tuckey

    1995-09-14T23:59:59.000Z

    We study the Hilbert bundle description of stochastic quantum mechanics in curved spacetime developed by Prugove\\v{c}ki, which gives a powerful new framework for exploring the quantum mechanical propagation of states in curved spacetime. We concentrate on the quantum transport law in the bundle, specifically on the information which can be obtained from the flat space limit. We give a detailed proof that quantum transport coincides with parallel transport in the bundle in this limit, confirming statements of Prugove\\v{c}ki. We furthermore show that the quantum-geometric propagator in curved spacetime proposed by Prugove\\v{c}ki, yielding a Feynman path integral-like formula involving integrations over intermediate phase space variables, is Poincar\\'e gauge covariant (i.e.$\\!$ is gauge invariant except for transformations at the endpoints of the path) provided the integration measure is interpreted as a ``contact point measure'' in the soldered stochastic phase space bundle raised over curved spacetime.

  11. Metallurgical characterization of brass objects from the Akko 1 shipwreck, Israel

    SciTech Connect (OSTI)

    Ashkenazi, D., E-mail: dana@eng.tau.ac.il [Faculty of Engineering, Tel Aviv University, Ramat Aviv 69978 (Israel); Cvikel, D. [Leon Recanati Institute for Maritime Studies, University of Haifa, 31905 (Israel); Stern, A. [Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Klein, S. [Institut für Geowissenschaften, Facheinheit Mineralogie, J. W. Goethe Universität, Altenhöferallee 1, D-60438 Frankfurt am Main (Germany); Kahanov, Y. [Leon Recanati Institute for Maritime Studies, University of Haifa, 31905 (Israel)

    2014-06-01T23:59:59.000Z

    The Akko 1 shipwreck was a small Egyptian armed vessel or auxiliary naval brig built in the eastern Mediterranean at the beginning of the 19th century. During the underwater excavations, about 230 brass hook-and-eye closures were found, mainly in the bow area. In addition, 158 brass cases were found, mainly between midships and the aft extremity of the shipwreck. Metallurgical non-destructive and destructive characterizations of selected items were performed, including radiographic testing, XRF, lead isotope analysis, optical microscopy, SEM–EDS and microhardness tests. The hook-and-eye closures and the cases were both found to be made of binary copper–zinc alloy (about 30 wt.% zinc). While the brass cases were made from rolled sheets, hand-made using simple tools, and joined by tin–lead soldering material, the brass hook-and-eye closures were hand-made from drawn brass wire, and manufactured from commercial drawn brass bars by a cold-working process. The lead isotope analyses suggest different provenances of the raw materials used for making the brass objects, thus the different origins of the ores may hint that the brass wire and sheet were imported to the workshops in which the objects were manufactured. - Highlights: • Brass cases and hook-and-eye closures were retrieved from the Akko 1 shipwreck. • Both types of objects were made of binary copper–zinc alloy (about 30 wt.% zinc). • The cases were hand-made from rolled sheets and joined by tin–lead soldering. • Hook-and-eye closures were made from drawn brass wire manufactured by cold-working. • Lead isotope analyses suggest that the origins of the raw material were diverse.

  12. Materials Compatibility and Aging for Flux and Cleaner Combinations.

    SciTech Connect (OSTI)

    Archuleta, Kim; Piatt, Rochelle

    2015-01-01T23:59:59.000Z

    A materials study of high reliability electronics cleaning is presented here. In Phase 1, mixed type substrates underwent a condensed contaminants application to view a worst- case scenario for unremoved flux with cleaning agent residue for parts in a silicone oil filled environment. In Phase 2, fluxes applied to copper coupons and to printed wiring boards underwent gentle cleaning then accelerated aging in air at 65% humidity and 30 O C. Both sets were aged for 4 weeks. Contaminants were no-clean (ORL0), water soluble (ORH1 liquid and ORH0 paste), and rosin (RMA; ROL0) fluxes. Defluxing agents were water, solvents, and engineered aqueous defluxers. In the first phase, coupons had flux applied and heated, then were placed in vials of oil with a small amount of cleaning agent and additional coupons. In the second phase, pairs of copper coupons and PWB were hand soldered by application of each flux, using tin-lead solder in a strip across the coupon or a set of test components on the PWB. One of each pair was cleaned in each cleaning agent, the first with a typical clean, and the second with a brief clean. Ionic contamination residue was measured before accelerated aging. After aging, substrates were removed and a visual record of coupon damage made, from which a subjective rank was applied for comparison between the various flux and defluxer combinations; more corrosion equated to higher rank. The ORH1 water soluble flux resulted in the highest ranking in both phases, the RMA flux the least. For the first phase, in which flux and defluxer remained on coupons, the aqueous defluxers led to worse corrosion. The vapor phase cleaning agents resulted in the highest ranking in the second phase, in which there was no physical cleaning. Further study of cleaning and rinsing parameters will be required.

  13. Reduced Coercive Field in BiFeO3 Thin Films through Domain Engineering

    SciTech Connect (OSTI)

    Shelke, Vilas K [ORNL] [ORNL; Mazumdar, Dipanjan [ORNL] [ORNL; Srinivasan, Dr. Gopalan [Oakland University, Rochester, MI] [Oakland University, Rochester, MI; Jesse, Stephen [ORNL] [ORNL; Kalinin, Sergei V [ORNL] [ORNL; Baddorf, Arthur P [ORNL] [ORNL; Gupta, Dr. Arunava [University of Alabama, Tuscaloosa] [University of Alabama, Tuscaloosa

    2011-01-01T23:59:59.000Z

    The bismuth ferrite (BiFeO3) material offers a comprehensive package of multifunctionality. In addition to the multiferroic behavior, i.e. coexistence of electric and magnetic orderings,[1] it also exhibits photovoltaic effect, [2] metal-insulator transition,[3] electric modulation of conduction,[4] and terahertz radiation emission.[5] The possibility of joint control of electric, magnetic, and optical properties provides several degrees of freedom to design exotic devices. It is a green energy material in the sense that it is lead-free and energy-efficient due to cryogen-less functionality. Therefore, a wide variety of applications in terms of sensors, memories and spintronic devices are foreseen.[6] However, the incipient lower value of magneto-electric coupling has raised skepticism regarding its multiferroic capabilities and allied applications.[6] Nevertheless, the highest value of ferroelectric polarization (~ 100 C.cm-2) is very promising for next generation ferroelectric random access memory devices.

  14. The electronic properties and lattice dynamics of (Na{sub 0.5}Bi{sub 0.5})TiO{sub 3}: From cubic to tetragonal and rhombohedral phases

    SciTech Connect (OSTI)

    Lü, Hongfeng [Department of Applied Physics, College of Science, China Agricultural University, Beijing 100083 (China); Wang, Shanying [Department of Physics, Tsinghua University, Beijing 100084 (China); Wang, Xiaosu, E-mail: xiaosuwang@cau.edu.cn [Department of Applied Physics, College of Science, China Agricultural University, Beijing 100083 (China); Department of Physics, Tsinghua University, Beijing 100084 (China)

    2014-03-28T23:59:59.000Z

    The structural, electronic and dynamical properties of the cubic, tetragonal and rhombohedral phases of a lead-free ferroelectrics, (Na{sub 0.5}Bi{sub 0.5})TiO{sub 3} (NBT), have been studied with a density functional formalism. The direct band gap is determined to be 2?3?eV for three phases, suggesting them to be good optical material. The equilibrium structures were given, and the importance of Bi atom in the low-symmetry ferroelectric phases were investigated with the electron localization functions analysis. The vibration modes at the ? point were calculated to provide a basis for analyzing the Raman and IR spectra. Soft modes were found in both the cubic and the tetragonal phases, providing a clue in understanding the ferroelectric phase transition in NBT.

  15. Quantum coherent transport in SnTe topological crystalline insulator thin films

    SciTech Connect (OSTI)

    Assaf, B. A.; Heiman, D. [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States); Katmis, F.; Moodera, J. S. [Francis Bitter Magnet Laboratory, MIT, Cambridge, Massachusetts 02139 (United States); Department of Physics, MIT, Cambridge, Massachusetts 02139 (United States); Wei, P. [Department of Physics, MIT, Cambridge, Massachusetts 02139 (United States); Satpati, B. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Zhang, Z. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bennett, S. P.; Harris, V. G. [Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States)

    2014-09-08T23:59:59.000Z

    Topological crystalline insulators (TCI) are unique systems where a band inversion that is protected by crystalline mirror symmetry leads to a multiplicity of topological surface states. Binary SnTe is an attractive lead-free TCI compound; the present work on high-quality thin films provides a route for increasing the mobility and reducing the carrier density of SnTe without chemical doping. Results of quantum coherent magnetotransport measurements reveal a multiplicity of Dirac surface states that are unique to TCI. Modeling of the weak antilocalization shows variations in the extracted number of carrier valleys that reflect the role of coherent intervalley scattering in coupling different Dirac states on the degenerate TCI surface.

  16. Low temperature synthesis of bismuth ferrite nanoparticles by a ferrioxalate precursor method

    SciTech Connect (OSTI)

    Ghosh, Sushmita [Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata, West Bengal 700032 (India); Dasgupta, Subrata [Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata, West Bengal 700032 (India)]. E-mail: sdasgupta@cgcri.res.in; Sen, Amarnath [Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata, West Bengal 700032 (India); Maiti, Himadri Sekhar [Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata, West Bengal 700032 (India)

    2005-12-08T23:59:59.000Z

    The synthesis of bismuth ferrite by solid-state reaction of Bi{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} results in the formation of multiphase products. Even coprecipitation followed by calcination leads to the formation of impurity phases. Here, we report the synthesis of magnetoelectric bismuth ferrite by a ferrioxalate precursor method. In this process, bismuth ferrite, synthesized through solutions of some specific salts led to the formation of phase pure (perovskite) nanocrystalline powder (11-22 nm as evident from X-ray diffraction analysis) at a temperature of 600 deg. C. The synthesized powders were characterized by X-ray diffractometry, thermogravimetry and differential thermal analysis, Fourier transformation infrared spectroscopy and scanning electron microscopy. The synthesis route is simple, energy saving and cost-effective. Such nanosized bismuth ferrite powder may have a potential application in making lead free piezoelectric materials for actuators as well as magnetoelectric sensors.

  17. Aging in the relaxor and ferroelectric state of Fe-doped (1-x)(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-xBaTiO{sub 3} piezoelectric ceramics

    SciTech Connect (OSTI)

    Sapper, Eva; Dittmer, Robert; Rödel, Jürgen [Materials Science Department, Technische Universität Darmstadt, 64287 Darmstadt (Germany); Damjanovic, Dragan [Ceramics Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne 1015 (Switzerland); Erdem, Emre [Institute of Physical Chemistry I, Universität Freiburg, 79104 Freiburg (Germany); Keeble, David J. [Division of Electronic Engineering and Physics, University of Dundee, Dundee DD1 4HN (United Kingdom); Jo, Wook [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Granzow, Torsten [Centre de Recherche Public—Gabriel Lippmann, L-4422 Belvaux (Luxembourg)

    2014-09-14T23:59:59.000Z

    Aging of piezoelectric properties was investigated in lead-free (1???x)(Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-xBaTiO{sub 3} doped with 1at.?% Fe. The relaxor character of the un-poled material prevents macroscopic aging effects, while in the field-induced ferroelectric phase aging phenomena are similar to those found in lead zirconate titanate or barium titanate. Most prominent aging effects are the development of an internal bias field and the decrease of switchable polarization. These effects are temperature activated, and can be explained in the framework of defect complex reorientation. This picture is further supported by electron paramagnetic resonance spectra indicating the existence of (Fe{sub Ti}{sup ?}?V{sub O}{sup ••}){sup •} defect complexes in the Fe-doped material.

  18. Dielectric, ferromagnetic and maganetoelectric properties of BaTiO{sub 3}–Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} composite ceramics

    SciTech Connect (OSTI)

    Zhang, Rong-Fen [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Deng, Chao-Yong, E-mail: cydeng@gzu.edu.cn [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Ren, Li [Department of Electronic Science, College of Science, Key Laboratory of Functional Composite Materials of Guizhou Province, Guizhou University, Guiyang, Guizhou 550025 (China); Li, Zheng [Department of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Zhou, Jian-Ping [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China)

    2013-10-15T23:59:59.000Z

    Graphical abstract: - Highlights: • The lead-free ME ceramic composites BaTiO{sub 3}–Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} were successfully synthesized. • The composites showed high dielectric constant and low dielectric loss. • The composite with 30% NiZn ferrite presented good soft magnetic properties and ME performance. - Abstract: Lead-free magnetoelectric composite ceramics (1 ? x)BaTiO{sub 3}–xNi{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} (x = 0.15, 0.3, 0.45) were successfully prepared by conventional oxide ceramic process. The tetragonal perovskite BaTiO{sub 3} and cubic spinel Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} were confirmed by X-ray diffraction. The dielectric behaviors of all composite samples show a normal response to the increasing measurement frequency and Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} ferrite content. Well defined ferromagnetic hysteresis loops and obvious magnetoelectric coupling effect are observed in the composite ceramics. The influence of applied dc bias magnetic field and Ni{sub 0.7}Zn{sub 0.3}Fe{sub 2}O{sub 4} ferrite content on the magnetoelectric coupling responding voltage is investigated. The strongest peak magnetoelectric coupling voltage coefficient is 124 ?V/cm Oe when x = 0.3, which corresponds to the maximum magnetoelectric coupling responding voltage of 200 ?V.

  19. Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

    SciTech Connect (OSTI)

    David Schwam, PI; Xuejun Zhu, Sr. Research Associate

    2012-09-30T23:59:59.000Z

    The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of cooling lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5"Ā¯ from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die lubricants and technical support. Experiments conducted with these lubricants demonstrated good protection of the substrate steel. Graphite and boron nitride used as benchmarks are capable of completely eliminating soldering and washout. However, because of cost and environmental considerations these materials are not widely used in industry. The best water-based die lubricants evaluated in this program were capable of providing similar protection from soldering and washout. In addition to improved part quality and higher production rates, improving die casting processes to preserve the life of the inserts will result in energy savings and a reduction in environmental wastes. Improving die life by means of optimized cooling line placement, baffles and bubblers in the die will allow for reduced die temperatures during processing, saving energy associated with production. The utilization of optimized die lubricants will also reduce heat requirements in addition to reducing waste associated with soldering and washout. This new technology was predicted to result in an average energy savings of 1.1 trillion BTU's/year over a 10 year period. Current (2012) annual energy saving estimates, based on commercial introduction in 2010, a market penetration of 70% by 2020 is 1.26 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.025 Million Metric Tons of Carbon Equivalent (MM TCE).

  20. Further Analysis of Accelerated Exposure Testing of Thin-Glass Mirror Matrix

    SciTech Connect (OSTI)

    Kennedy, C. E.; Terwilliger, K.; Jorgensen, G. J.

    2007-01-01T23:59:59.000Z

    Concentrating solar power (CSP) companies have deployed thin-glass mirrors produced by wet-silver processes on {approx}1-mmthick, relatively lightweight glass. These mirrors are bonded to metal substrates in commercial installations and have the confidence of the CSP industry. Initial hemispherical reflectance is {approx}93%-96%, and the cost is {approx}$16.1/m{sup 2}-$43.0/m{sup 2}. However, corrosion was observed in mirror elements of operational solar systems deployed outdoors for 2 years. National Renewable Energy Laboratory (NREL) Advanced Materials Team has been investigating this problem. First, it was noted that this corrosion is very similar to the corrosion bands and spots observed on small (45 mm x 67 mm) thin-glass mirrors laminated to metal substrates with several different types of adhesives and subjected to accelerated exposure testing (AET) at NREL. The corrosion appears as dark splotches in the center of the mirror, with a corresponding 5%-20% loss in reflectivity. Secondly, two significant changes in mirror manufacture have occurred in the wet-chemistry process because of environmental concerns. The first is the method of forming a copper-free reflective mirror, and the second is the use of lead-free paints. However, the copper-free process requires stringent quality control and the lead-free paints were developed for interior applications. A test matrix of 84 combinations of sample constructions (mirror type/backprotective paint/adhesive/substrate) was devised for AET as a designed experiment to identify the most-promising mirrors, paints, and adhesives for use with concentrator designs. Two types of accelerated exposure were used: an Atlas Ci5000 WeatherOmeter (CI5000) and a BlueM damp-heat chamber. Based on an analysis of variance (ANOVA), the various factors and interactions were modeled. These samples now have more than 36 months of accelerated exposure, and most samples have completed their test cycle. We will discuss the results of the final exposure testing of these mirror samples. Glass mirrors with copper back-layers and heavily leaded paints have been considered robust for outdoor use. However, the basic mirror composition of the new mirrors is radically different from that of historically durable solar mirrors, and the outdoor durability must be determined.

  1. Low thermal resistance power module assembly

    DOE Patents [OSTI]

    Hassani, Vahab (Denver, CO); Vlahinos, Andreas (Castle Rock, CO); Bharathan, Desikan (Arvada, CO)

    2010-12-28T23:59:59.000Z

    A power module assembly (400) with low thermal resistance and enhanced heat dissipation to a cooling medium. The assembly includes a heat sink or spreader plate (410) with passageways or openings (414) for coolant that extend through the plate from a lower surface (411) to an upper surface (412). A circuit substrate (420) is provided and positioned on the spreader plate (410) to cover the coolant passageways. The circuit substrate (420) includes a bonding layer (422) configured to extend about the periphery of each of the coolant passageways and is made up of a substantially nonporous material. The bonding layer (422) may be solder material which bonds to the upper surface (412) of the plate to provide a continuous seal around the upper edge of each opening (414) in the plate. The assembly includes power modules (430) mounted on the circuit substrate (420) on a surface opposite the bonding layer (422). The power modules (430) are positioned over or proximal to the coolant passageways.

  2. Microchannel heat sink assembly

    DOE Patents [OSTI]

    Bonde, W.L.; Contolini, R.J.

    1992-03-24T23:59:59.000Z

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watertight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures. 13 figs.

  3. Robust hermetic packaging techniques for MEMS integrated microsystems.

    SciTech Connect (OSTI)

    Chae, Junseok (University of Michigan); Stark, Brian H. (University of Michigan); Kuo, Andrew (University of Michigan); Oliver, Andrew David; Najafi, Khalil (University of Michigan)

    2005-03-01T23:59:59.000Z

    This work is the result of a Sandia National Laboratories LDRD funded fellowship at the University of Michigan. Although, guidance and suggestions were offered by Sandia, the work contained here is primarily the work of Brian H. Stark, and his advisor, Professor Khalil Najafi. Junseok Chae, Andrew Kuo, and their coworkers at the University of Michigan helped to record some of the data. The following is an abstract of their work. We have developed a vacuum packaging technology using a thick nickel film to seal MEMS structures at the wafer level. The package is fabricated in a three-mask process by electroplating a 40 micro-meter thick nickel film over an 8 micro-meter sacrificial photoresist that is removed prior to package sealing. Implementation of electrical feedthroughs in this process requires no planarization. The large release channel enables an 800x800 micro-meter package to be released in less than three hours. Several mechanisms, based upon localized melting and lead/tin solder bumping, for sealing the release channel have been investigated. We have also developed Pirani gauges, integrated with this package, which can be used to establish the hermeticity of the different sealing technologies. They have measured a sealing pressure of approximately 1.5 Torr. Our work differs from previous Pirani gauges in that we utilize a novel doubly anchored structure that stiffens the structural membrane while not substantially degrading performance in order to measure fine leak rates.

  4. AC Loss Measurements on a 2G YBCO Coil

    SciTech Connect (OSTI)

    Rey, Christopher M [ORNL] [ORNL; Duckworth, Robert C [ORNL] [ORNL; Schwenterly, S W [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES) to continue development of HTS power transformers. For compatibility with the existing power grid, a commercially viable HTS transformer will have to operate at high voltages in the range of 138 kV and above, and will have to withstand 550-kV impulse voltages as well. Second-generation (2G) YBCO coated conductors will be required for an economically-competitive design. In order to adequately size the refrigeration system for these transformers, the ac loss of these HTS coils must be characterized. Electrical AC loss measurements were conducted on a prototype high voltage (HV) coil with co-wound stainless steel at 60 Hz in a liquid nitrogen bath using a lock-in amplifier technique. The prototype HV coil consisted of 26 continuous (without splice) single pancake coils concentrically centered on a stainless steel former. For ac loss measurement purposes, voltage tap pairs were soldered across each set of two single pancake coils so that a total of 13 separate voltage measurements could be made across the entire length of the coil. AC loss measurements were taken as a function of ac excitation current. Results show that the loss is primarily concentrated at the ends of the coil where the operating fraction of critical current is the highest and show a distinct difference in current scaling of the losses between low current and high current regimes.

  5. Low cost impulse compatible wideband antenna

    DOE Patents [OSTI]

    Rosenbury, Erwin T. (Livermore, CA); Burke, Gerald J. (Livermore, CA); Nelson, Scott D. (Tracy, CA); Stever, Robert D. (Lathrop, CA); Governo, George K. (Livermore, CA); Mullenhoff, Donald J. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    An antenna apparatus and method for building the antenna is disclosed. Impulse signals travel through a feed point of the antenna with respect to a ground plane. A geometric fin structure is connected to the feed point, and through a termination resistance to the ground plane. A geometric ridge structure connected to the ground is positioned with respect to the fin in order to receive and radiate electromagnetic energy from the impulse signal at a predetermined impedance and over a predetermined set of frequencies. The fin and ridge can be either a wire or a planar surface. The fin and ridge may be disposed within a radiation cavity such as a horn. The radiation cavity is constructed of stamped and etched metal sheets bent and then soldered together. The fin and ridge are also formed from metal sheets or wires. The fin is attached to the feed point and then to the cavity through a termination resistance. The ridge is attached to the cavity and disposed with respect to the fin in order to achieve a particular set of antenna characteristics.

  6. Liquid immiscibility and core-shell morphology formation in ternary Al–Bi–Sn alloys

    SciTech Connect (OSTI)

    Dai, R.; Zhang, J.F.; Zhang, S.G., E-mail: sgzhang@sjtu.edu.cn; Li, J.G.

    2013-07-15T23:59:59.000Z

    The effects of composition on liquid immiscibility, macroscopic morphology, microstructure and phase transformation in ternary Al–Bi–Sn alloys were investigated. Three types of morphology, the core-shell type, the stochastic droplet type and uniform dispersion type, of Al–Bi–Sn particles prepared by a jet breakup process were distinguished, and the relationships between which were discussed. The phase transformation behaviors of the Al–Bi–Sn alloys were studied by thermal analysis, in agreement with the microstructural observation and microanalysis. The liquid immiscibility and formation of the core-shell morphology in Al–Bi–Sn alloys are easily achieved when the composition lies in the liquid miscibility gap. The particles exhibit a high melting point Al-rich core with a low melting point Sn–Bi-rich solder shell, showing promise for application as high-density electronic packaging materials. - Highlights: • The liquid demixing, morphology and microstructure in Al–Bi–Sn alloys were studied. • Three types of morphology were classified and discussed. • The conditions for formation of the core-shell morphology were obtained. • The phase transition behaviors agree with the microstructure characterization. • The Al/Sn–Bi core-shell particles show promise for use in electronic packaging.

  7. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, Aaron S. (Broomall, PA)

    1985-01-01T23:59:59.000Z

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  8. A novel planar ion funnel design for miniature ion optics

    SciTech Connect (OSTI)

    Chaudhary, A.; Amerom, Friso H. W. van; Short, R. T. [Space and Marine Technology Laboratory, SRI International, 450 8th Ave SE, St. Petersburg, Florida 33701 (United States)

    2014-10-15T23:59:59.000Z

    The novel planar ion funnel (PIF) design presented in this article emphasizes simple fabrication, assembly, and operation, making it amenable to extreme miniaturization. Simulations performed in SIMION 8.0 indicate that ion focusing can be achieved by using a gradient of electrostatic potentials on concentric metal rings in a plane. A prototype was fabricated on a 35 × 35 mm custom-designed printed circuit board (PCB) with a center hole for ions to pass through and a series of concentric circular metal rings of increasing diameter on the front side of the PCB. Metal vias on the PCB electrically connected each metal ring to a resistive potential divider that was soldered on the back of the PCB. The PIF was tested at 5.5 × 10{sup ?6} Torr in a vacuum test setup that was equipped with a broad-beam ion source on the front and a micro channel plate (MCP) ion detector on the back of the PIF. The ion current recorded on the MCP anode during testing indicated a 23× increase in the ion transmission through the PIF when electric potentials were applied to the rings. These preliminary results demonstrate the functionality of a 2D ion funnel design with a much smaller footprint and simpler driving electronics than conventional 3D ion funnels. Future directions to improve the design and a possible micromachining approach to fabrication are discussed in the conclusions.

  9. The Calculated and Measured Resistance for Splices between Conductors in a MICE Superconducting Coil

    SciTech Connect (OSTI)

    Green, Michael A.; Dietderich, Dan; Higley, Hugh; Pan, Heng; Tam, Darren; Trillaud, Federic; Wang, Li; Wu, Hong; Xu, Feng Yu

    2009-03-19T23:59:59.000Z

    The resistance of superconducting joints within MICE coils is an important issue particularly for the coupling coils. The MICE tracker solenoids have only two superconducting joints in the three spectrometer set (end coil 1, the center coil and end coil 2). The AFC magnets may have only a single joint within the coil. The coupling coils may have as many as fifteen joints within the coil, due to relatively short piece lengths of the superconductor. LBNL and ICST looked at three types of coil joints. They are: (1) cold fusion butt joints, (2) side-by-side lap joints, and (3) up-down lap joints. A theoretical calculation of the joint resistance was done at LBNL and checked by ICST. After looking at the theoretical resistance of the three types of joints, it was decided that the cold welded butt joint was not an attractive alternative for joints within a MICE superconducting magnet coil. Side-by-side and up-down lap joints were fabricated at ICST using two types of soft solder between the conductors. These conductor joints were tested at LBNL at liquid helium temperatures over a range of magnetic fields. The joint resistance was compared with the theoretical calculations. Measurements of splice strength were also made at 300 K and 77 K.

  10. Engine coolant technology, performance, and life for light-duty applications

    SciTech Connect (OSTI)

    Turcotte, D.E.; Lockwood, F.E. [Valvoline Co., Lexington, KY (United States); Pfitzner, K.K.; Meszaros, L.L. [BASF Aktiengesellschaft, Ludwigshafen (Germany); Listebarger, J.K. [Ashland Chemical, Dublin, OH (United States)

    1999-08-01T23:59:59.000Z

    Recently there has been interest by motor vehicle manufacturers in developing longer-lived automotive engine coolants with an emphasis on organic acid technology (OAT). Paradoxically, the lifetime of conventional technology remains largely undefined. Concerns arising from the depleting nature of silicate have led to modern conservative change recommendations of 30,000 to 50,000 miles ({approximately}48,279 to 80,464 km). In the present work, laboratory bench test, engine dynamometer and vehicle service data from traditional silicate, hybrid and nonsilicate coolants are compared and contrasted. A new electrochemical test is used to examine passivation kinetics on aluminum. It is shown that performance and lifetime are independent of chemistry and cannot be generalized. Examples include an American silicate coolant with excellent performance on high-heat-rejecting aluminum (80 W/cm{sup 2}). European and American silicate coolants with performance defined lifetimes in excess of 300,000 miles (482,790 km), and an OAT coolant with laboratory high lead solder protection. It is concluded that the primary benefit of OAT is to meet global specifications that include chemical limitations.

  11. Innovative Seals for Solid Oxide Fuel Cells (SOFC)

    SciTech Connect (OSTI)

    Singh, Raj

    2008-06-30T23:59:59.000Z

    A functioning SOFC requires different type of seals such as metal-metal, metal-ceramic, and ceramic-ceramic. These seals must function at high temperatures between 600--900{sup o}C and in oxidizing and reducing environments of the fuels and air. Among the different type of seals, the metal-metal seals can be readily fabricated using metal joining, soldering, and brazing techniques. However, the metal-ceramic and ceramic-ceramic seals require significant research and development because the brittle nature of ceramics/glasses can lead to fracture and loss of seal integrity and functionality. Consequently, any seals involving ceramics/glasses require a significant attention and technology development for reliable SOFC operation. This final report is prepared to describe the progress made in the program on the needs, approaches, and performance of high temperature seals for SOFC. In particular, a new concept of self-healing glass seals is pursued for making seals between metal-ceramic material combinations, including some with a significant expansion mismatch.

  12. Automated array assembly. Phase II. Final report, October 1977-December 1979

    SciTech Connect (OSTI)

    D'Aiello, R. V.

    1980-10-01T23:59:59.000Z

    The philosophy of this project was to establish an experimental process line starting with 3-in.-diameter silicon wafers and consisting of junction formation using POCl/sub 3/ gaseous diffusion, screen-printed thick-film metallization, reflow solder interconnect, and double-glass lamination panel assembly. This experimental production line produced a sufficient number of solar cells to demonstrate the technological readiness of each of those process steps. Variations (of each process) were made to set limits on the usable range of each process step and to determine the interaction with adjoining steps. Inspections, measurements, and tests were included to determine the output requirement characteristics of each step, obtain statistical variations, and evaluate the performance of the solar cells and panels. A description of this work, which was conducted from October 1977 through December 1978, is given. This was followed by an 18-month study in which three manufacturing sequences synthesized from the previous work and from studies conducted by other participants in the LSA program were exercised. The objectives were to assess the compatibility between process steps for each sequence, to generate sufficient data for comparative SAMICS cost analysis, and to make recommendations of the suitability of one or more of these sequences for the large-scale automated production of solar cells within the cost goal of $0.70/pW. The detailed experimental results of this study are described, followed by SAMICS cost analysis, recommendations, and conclusions.

  13. In situ visualization of metallurgical reactions in nanoscale Cu/Sn diffusion couples

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yin, Qiyue; Stach, Eric A.; Gao, Fan; Zhou, Guangwen; Gu, Zhiyong

    2015-01-01T23:59:59.000Z

    The Cu–Sn metallurgical soldering reaction in two-segmented Cu–Sn nanowires is visualized by in-situ transmission electron microscopy. By varying the relative lengths of Cu and Sn segments, we show that the metallurgical reaction starts at ~ 200 ° with the formation of a Cu–Sn solid solution for the Sn/Cu length ratio smaller than 1:5 while the formation of Cu–Sn intermetallic compounds (IMCs) for larger Sn/Cu length ratios. Upon heating the nanowires up to ~ 500 °C, two phase transformation pathways occur, ?-Cu?Sn? ? ?-Cu?Sn ? ?-Cu??Sn?? for nanowires with a long Cu segment and ?-Cu?Sn? ? ?-Cu?Sn ? ?-Cu?Sn with amore »short Cu segment. The dynamic in situ TEM visualization of the evolution of Kirkendall voids demonstrates that Cu diffuses faster both in Sn and IMCs than that of Sn in Cu? and IMCs, which is the underlying cause of the dependence of the IMC formation and associated phase evolution on the relative lengths of the Cu and Sn segments.« less

  14. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, A.S.

    1983-12-08T23:59:59.000Z

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  15. FBIS Report: Science and Technology. Central Eurasia

    SciTech Connect (OSTI)

    NONE

    1995-09-01T23:59:59.000Z

    Translated articles cover the following topics: Superluminescence Polarization and Anisotropy of Optical Losses in a InGaP/GaAs/InGaP Waveguide Structure; Features of Volt-Ampere Characteristic of an Asymmetrical System of GaAs/AlGaAs Quantum Wells Separated by Wide Barriers; Propagation Dynamics of a Pair of Soliton Pulses in a Fiber Lightguide With Losses; Mechanical Properties and Structure of High-Temperature Superconducting YBCO/Cu(gamma) O Composites; Effect on Ion Bombardment on Alloys of the System Titanium-Aluminum; Epitaxial Growth of TiN Layer With Implantation of Ti(+) Ions into Mo in a Nitrogen Atmosphere and the Effect of Radiation and Heat Treatment on the Structure of the Coating-Substrate Transition Layer; Mechanical Properties and Recrystallization of Alumina Ceramic Reinforced With SiC Whiskers; Phase Equilibria and Formation of Eutectic Structure in Alloys of Chromium With Titanium Nitride; Effect of the Structure of Boron-Containing Iron Matrix Composites on Wear Processes; Effect of Plasma Application Conditions on the Structure of Fe-Mo-Cr-Ni-B Alloy Coatings; Aluminum-Lithium Alloys for Welded Aerospace Equipment (Overview); Features of Surface Cleaning of Oxides from Titanium Parts in Arc Soldering in Vacuum.

  16. Apparatus And Method Of Using Flexible Printed Circuit Board In Optical Transceiver Device

    DOE Patents [OSTI]

    Anderson, Gene R. (Albuquerque, NM); Armendariz, Marcelino G. (Albuquerque, NM); Bryan, Robert P. (Albuquerque, NM); Carson, Richard F. (Albuquerque, NM); Duckett, III, Edwin B. (Albuquerque, NM); McCormick, Frederick B. (Albuquerque, NM); Peterson, David W. (Sandia Park, NM); Peterson, Gary D. (Albuquerque, NM); Reysen, Bill H. (Lafayette, CO)

    2005-03-15T23:59:59.000Z

    This invention relates to a flexible printed circuit board that is used in connection with an optical transmitter, receiver or transceiver module. In one embodiment, the flexible printed circuit board has flexible metal layers in between flexible insulating layers, and the circuit board comprises: (1) a main body region orientated in a first direction having at least one electrical or optoelectronic device; (2) a plurality of electrical contact pads integrated into the main body region, where the electrical contact pads function to connect the flexible printed circuit board to an external environment; (3) a buckle region extending from one end of the main body region; and (4) a head region extending from one end of the buckle region, and where the head region is orientated so that it is at an angle relative to the direction of the main body region. The electrical contact pads may be ball grid arrays, solder balls or land-grid arrays, and they function to connect the circuit board to an external environment. A driver or amplifier chip may be adapted to the head region of the flexible printed circuit board. In another embodiment, a heat spreader passes along a surface of the head region of the flexible printed circuit board, and a window is formed in the head region of the flexible printed circuit board. Optoelectronic devices are adapted to the head spreader in such a manner that they are accessible through the window in the flexible printed circuit board.

  17. Advances in metal matrix composite packaging for use in alternative energy transportation systems

    SciTech Connect (OSTI)

    Martinez, J.L. Jr.; Fusaro, J.M.; Romero, G.L. [Motorola Inc., Phoenix, AZ (United States)] [and others

    1996-12-31T23:59:59.000Z

    The packaging of power semiconductors for use in ac motor control inverters for zero-emission vehicles has typically included a copper baseplate onto which a ceramic isolation structure is mounted. The ceramic isolation Structure is used to mount semiconductor devices and mechanically route the electrical Circuit. All components, including buss bars, are encased in a molded plastic housing. Due to its high thermal conductivity and low cost, copper has been the material of choice for baseplates in the manufacture of power modules. In operation, the power module is required to dissipate large amounts of heat generated by the semiconductor devices. Thermal and mechanical stresses are induced into the package due to the differences in the coefficient of thermal expansion (CTE) between the various materials. These stresses are large enough to produce cracks in the ceramic and solder bonding layers. The cracking of material in either case inhibits the removal of heat from the semiconductor devices and eventually causessemiconductor device failure. Metal Matrix Composites (MMC`s) have been used in the aerospace industry for years in structural designs and in the packaging of electronic components. Motorola`s Hybrid Power Module Operation (HPM) has been investigating MMC`s, particularly Aluminum/Silicon Carbide (AISiC), for use as the baseplate of power modules. The properties of AISiC, particularly its CTE and thermal conductivity, have made it a viable candidate to replace copper in these applications. Findings on thermal performance, reliability, manufacturability, and package integration are presented.

  18. Investigation on transition behavior and electrical properties of (K{sub 0.5}Na{sub 0.5}){sub 1-x}Li{sub x}Nb{sub 0.84}Ta{sub 0.1}Sb{sub 0.06}O{sub 3} around polymorphic phase transition region

    SciTech Connect (OSTI)

    Zhu, Chen; Wang, Wenchao; Shi, Honglin; Wang, Fangyu; Cao, Yongge [Department of Physics, Renmin University of China, Beijing 100872, P R China (China) [Department of Physics, Renmin University of China, Beijing 100872, P R China (China); Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Huang, Jiquan; Wang, Chong [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)] [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Tang, Fei; Yuan, Xuanyi, E-mail: yuanxuanyi@ruc.edu.cn [Department of Physics, Renmin University of China, Beijing 100872, P R China (China)] [Department of Physics, Renmin University of China, Beijing 100872, P R China (China); Liu, Yang [School of Chemistry and Environment Engineering, Shaoguan University, Shaoguan 512005 (China)] [School of Chemistry and Environment Engineering, Shaoguan University, Shaoguan 512005 (China)

    2014-01-15T23:59:59.000Z

    (K{sub 0.5}Na{sub 0.5}){sub 1-x}Li{sub x}Nb{sub 0.84}Ta{sub 0.1}Sb{sub 0.06}O{sub 3} (KNLNTS) lead free ceramics with different Li concentration were fabricated by conventional solid-state reaction method. By increasing Li ions in KNLNTS, the grains grow up and the crystal structure changes from orthorhombic to tetragonal. When 0.03 ? x ? 0.05, the ceramics structure lays in PPT region. Polarization versus electric field (P-E) hysteresis loops at room temperature show good ferroelectric properties and the remnant polarization decreases by increasing Li content while coercive electric keeps almost unchanged. In PPT region, taking x = 0.04 as an example, the sample shows excellent dielectric properties: the dielectric constant is 1159 and loss tangent is 0.04, while the piezoelectric constant d{sub 33} is 245 pC/N and kp is 0.44 at room temperature, it is promising for (K{sub 0.5}Na{sub 0.5}){sub 1-x}Li{sub x}Nb{sub 0.84}Ta{sub 0.1}Sb{sub 0.06}O{sub 3} with 4 at. % Li to substitute PZT.

  19. Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Use of Laser Engineered Net Shaping for Rapid Manufacturing of Dies with Protective Coatings and Improved Thermal Management

    SciTech Connect (OSTI)

    Brevick, Jerald R. [Ohio State University

    2014-06-13T23:59:59.000Z

    In the high pressure die casting process, molten metal is introduced into a die cavity at high pressure and velocity, enabling castings of thin wall section and complex geometry to be obtained. Traditional die materials have been hot work die steels, commonly H13. Manufacture of the dies involves machining the desired geometry from monolithic blocks of annealed tool steel, heat treating to desired hardness and toughness, and final machining, grinding and polishing. The die is fabricated with internal water cooling passages created by drilling. These materials and fabrication methods have been used for many years, however, there are limitations. Tool steels have relatively low thermal conductivity, and as a result, it takes time to remove the heat from the tool steel via the drilled internal water cooling passages. Furthermore, the low thermal conductivity generates large thermal gradients at the die cavity surfaces, which ultimately leads to thermal fatigue cracking on the surfaces of the die steel. The high die surface temperatures also promote the metallurgical bonding of the aluminum casting alloy to the surface of the die steel (soldering). In terms of process efficiency, these tooling limitations reduce the number of die castings that can be made per unit time by increasing cycle time required for cooling, and increasing downtime and cost to replace tooling which has failed either by soldering or by thermal fatigue cracking (heat checking). The objective of this research was to evaluate the feasibility of designing, fabricating, and testing high pressure die casting tooling having properties equivalent to H13 on the surface in contact with molten casting alloy - for high temperature and high velocity molten metal erosion resistance – but with the ability to conduct heat rapidly to interior water cooling passages. A layered bimetallic tool design was selected, and the design evaluated for thermal and mechanical performance via finite element analysis. H13 was retained as the exterior layer of the tooling, while commercially pure copper was chosen for the interior structure of the tooling. The tooling was fabricated by traditional machining of the copper substrate, and H13 powder was deposited on the copper via the Laser Engineered Net Shape (LENSTM) process. The H13 deposition layer was then final machined by traditional methods. Two tooling components were designed and fabricated; a thermal fatigue test specimen, and a core for a commercial aluminum high pressure die casting tool. The bimetallic thermal fatigue specimen demonstrated promising performance during testing, and the test results were used to improve the design and LENS TM deposition methods for subsequent manufacture of the commercial core. Results of the thermal finite element analysis for the thermal fatigue test specimen indicate that it has the ability to lose heat to the internal water cooling passages, and to external spray cooling, significantly faster than a monolithic H13 thermal fatigue sample. The commercial core is currently in the final stages of fabrication, and will be evaluated in an actual production environment at Shiloh Die casting. In this research, the feasibility of designing and fabricating copper/H13 bimetallic die casting tooling via LENS TM processing, for the purpose of improving die casting process efficiency, is demonstrated.

  20. GOMA - A full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport: User`s guide

    SciTech Connect (OSTI)

    Schunk, P.R.; Sackinger, P.A.; Rao, R.R. [and others] [and others

    1996-01-01T23:59:59.000Z

    GOMA is a two- and three-dimensional finite element program which excels in analyses of manufacturing processes, particularly those involving free or moving interfaces. Specifically, the full-Newton-coupled heat, mass, momentum, and pseudo-solid mesh motion algorithm makes GOMA ideally suited for simulating processes in which the bulk fluid transport is closely coupled to the interfacial physics. Examples include, but are not limited to, coating and polymer processing flows, soldering, crystal growth, and solid-network or solution film drying. The code is based on the premise that any boundary can be (1) moving or free, with an apriori unknown position dictated by the distinguishing physics, (2) fixed, according to a global analytical representation, or (3) moving in time and space under user-prescribed kinematics. The goal is to enable the user to predict boundary position or motion simultaneously with the physics of the problem being analyzed and to pursue geometrical design studies and fluid-structure interaction problems. The moving mesh algorithm treats the entire domain as a computational Lagrangian solid that deforms subject to the physical principles which dictate boundary position. As an added benefit, the same Lagrangian solid mechanics can be exploited to solve multi-field problems for which the solid motion and stresses interact with other transport phenomena, either within the same material phase (e.g. shrinking coating) or in neighboring material phases (e.g. flexible blade coating). Thus, analyses of many fluid-structure interaction problems and deformable porous media problems are accessible. This document serves as a user`s guide and reference for GOMA and provides a brief overview of GOMA`s capabilities, theoretical background, and classes of problems for which it is targeted.

  1. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

    SciTech Connect (OSTI)

    Dr. John J. Moore; Dr. Jianliang Lin,

    2012-07-31T23:59:59.000Z

    The main objective of this research program was to design and develop an optimal coating system that extends die life by minimizing premature die failure. In high-pressure aluminum die-casting, the die, core pins and inserts must withstand severe processing conditions. Many of the dies and tools in the industry are being coated to improve wear-resistance and decrease down-time for maintenance. However, thermal fatigue in metal itself can still be a major problem, especially since it often leads to catastrophic failure (i.e. die breakage) as opposed to a wear-based failure (parts begin to go out of tolerance). Tooling costs remain the largest portion of production costs for many of these parts, so the ability prevent catastrophic failures would be transformative for the manufacturing industry.The technology offers energy savings through reduced energy use in the die casting process from several factors, including increased life of the tools and dies, reuse of the dies and die components, reduction/elimination of lubricants, and reduced machine down time, and reduction of Al solder sticking on the die. The use of the optimized die coating system will also reduce environmental wastes and scrap parts. Current (2012) annual energy saving estimates, based on initial dissemination to the casting industry in 2010 and market penetration of 80% by 2020, is 3.1 trillion BTU's/year. The average annual estimate of CO2 reduction per year through 2020 is 0.63 Million Metric Tons of Carbon Equivalent (MM TCE).

  2. Deactivation of the EBR-II complex

    SciTech Connect (OSTI)

    Michelbacher, J.A.; Earle, O.K.; Henslee, S.P. [and others

    1997-12-31T23:59:59.000Z

    In January of 1994, the Department of Energy mandated the termination of the Integral Fast Reactor (IFR) Program, effective October 1, 1994. To comply with this decision, Argonne National Laboratory-West (ANL-W) prepared a plan providing detailed requirements to place the Experimental Breeder Reactor-II (EBR-II) in a radiologically and industrially safe condition, including removal of all irradiated fuel assemblies from the reactor plant, and removal and stabilization of the primary and secondary sodium, a liquid metal used to transfer heat within the reactor plant. The ultimate goal of the deactivation process is to place the EBR-II complex in a stable condition until a decontamination and decommissioning (D&D) plan can be prepared, thereby minimizing requirements for maintenance and surveillance and maximizing the amount of time for radioactive decay. The final closure state will be achieved in full compliance with federal, state and local environmental, safety, and health regulations and requirements. The decision to delay the development of a detailed D&D plan has necessitated this current action. The EBR-II is a pool-type reactor. The primary system contains approximately 87,000 gallons of sodium, while the secondary system has 13,000 gallons. In order to properly dispose of the sodium in compliance with the Resource Conservation and Recovery Act (RCRA), a facility has been built to react the sodium to a dry carbonate powder in a two stage process. Deactivation of a liquid metal fast breeder reactor (LMFBR) presents unique concerns. Residual amounts of sodium remaining in the primary and secondary systems must be either reacted or inerted to preclude future concerns with sodium-air reactions that generate explosive mixtures of hydrogen and leave corrosive compounds. Residual amounts of sodium on components will effectively {open_quotes}solder{close_quotes} components in place, making future operation or removal unfeasible.

  3. New adhesive systems based on functionalized block copolymers

    SciTech Connect (OSTI)

    Kent, M.; Saunders, R.; Hurst, M.; Small, J.; Emerson, J.; Zamora, D.

    1997-05-01T23:59:59.000Z

    The goal of this work was to evaluate chemically-functionalized block copolymers as adhesion promoters for metal/thermoset resin interfaces. Novel block copolymers were synthesized which contain pendant functional groups reactive toward copper and epoxy resins. In particular, imidazole and triazole functionalities that chelate with copper were incorporated onto one block, while secondary amines were incorporated onto the second block. These copolymers were found to self-assemble from solution onto copper surfaces to form monolayers. The structure of the adsorbed monolayers were studied in detail by neutron reflection and time-of-flight secondary ion mass spectrometry. The monolayer structure was found to vary markedly with the solution conditions and adsorption protocol. Appropriate conditions were found for which the two blocks form separate layers on the surface with the amine functionalized block exposed at the air surface. Adhesion testing of block copolymer-coated copper with epoxy resins was performed in both lap shear and peel modes. Modest enhancements in bond strengths were observed with the block copolymer applied to the native oxide. However, it was discovered that the native oxide is the weak link, and that by simply removing the native oxide, and then applying an epoxy resin before the native oxide can reform, excellent bond strength in the as-prepared state as well as excellent retention of bond strength after exposure to solder in ambient conditions are obtained. It is recommended that long term aging studies be performed with and without the block copolymer. In addition, the functionalized block copolymer method should be evaluated for another system that has inherently poor bonding, such as the nickel/silicone interface, and for systems involving metals and alloys which form oxides very rapidly, such as aluminum and stainless steel, where bonding strategies involve stabilizing the native oxide.

  4. Mechanical stabilization of BSCCO-2223 superconducting tapes

    SciTech Connect (OSTI)

    King, C.G.; Grey, D.A.; Mantone, A. [GE Medical Systems, Florence, SC (United States)] [and others

    1996-12-31T23:59:59.000Z

    A system to provide mechanical stabilization to high temperature BSCCO-2223 superconducting tape by laminating 0.081 mm thick, spring hard, copper foil to both sides with lead-tin eutectic solder has been successfully optimized. This system has been applied as a method to create a strong, windable composite from pure silver BSCCO tapes with a minimum of critical current (I{sub c}) degradation. The {open_quotes}as received{close_quotes} conductor is evaluated for physical consistency of width and thickness over the 3000 meters that were later strengthened, insulated and wound into a demonstration coil. Electrical degradation in the strengthened tape as a result of lamination was found to average 24 percent with a range from 4 to 51 percent. This was less than the degradation that would have occurred in an unstrengthened tape during subsequent insulation and coil winding processes. Additional work was performed to evaluate the mechanical properties of the strengthened tapes. The copper can double the ultimate tensile strength of the pure silver tapes. Additionally, pure silver and dispersion strengthened silver matrix tapes are laminated with 0.025 mm thick copper and 304 stainless steel foil to investigate minimization of the cross sectional area of the strengthening component. The stainless steel can increase the UTS of the pure silver tapes sixfold. Metallography is used to examine the laminate and the conductor. Mechanical properties and critical currents of these tapes are also reported both before and after strengthening. The I{sub c} is also measured as a function of strain on the laminated tapes.

  5. Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report

    SciTech Connect (OSTI)

    Britt, J.; Wiedeman, S.; Albright, S.

    2000-11-09T23:59:59.000Z

    As a technology partner with NREL, Global Solar Energy (GSE) has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) based on copper indium gallium diselenide (CIGS). The distinguishing feature of the GSE manufacturing process is the exclusive use of lightweight, flexible substrates. GSE has developed the technology to fabricate CIGS photovoltaics on both stainless-steel and polymer substrates. CIGS deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunication, and rooftop applications have been produced by affixing the flexible substrate to an inexpensive rigid panel by lamination or adhesive. Stainless-steel-based PV modules are fabricated by a novel interconnect method that avoids the use of wires or foils and soldered connections. In the case of polymer-based PV modules, the continuous roll is not sectioned into individual panels until the module buss and power leads are attached. Roll-to-roll vacuum deposition has several advantages that translate directly to reduced capital costs, greater productivity, improved yield, greater reliability, lower maintenance, and a larger volume of PV material. In combination with roll-to-roll processing, GSE has developed evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. The CIGS deposition process relies heavily on effusion source technology developed at GSE, and solving numerous problems was an integral part of the source development effort. Cell interconnection for thin-film CIGS modules on a polyimide substrate presents a considerable challenge.

  6. An evaluation of chemical screening test kits for lead in paint

    SciTech Connect (OSTI)

    Oglesby, L.S.

    1996-04-01T23:59:59.000Z

    The Residential Lead-Based Paint Hazard Reduction Act (Title X) requires abatement and management of lead-based paint. The purpose of this study was to evaluate three chemical screening test kits using materials and methods from one study and subjecting the results to the statistical analysis of another. The three kits were used to predict the presence of lead in paint at ten weight concentrations from 0.04 to 3.97%. Paint was applied to four wood boards yielding a sample size of 40. Four boards were painted with lead-free paint and used as blanks. All of the boards were tested with the three test kits by an untrained individual having no knowledge of the actual lead content. Sensitivity, specificity, and false positive and negative rates were calculated for the test kit results. The manufactures` detection limits, the observed sensitivity ranged from 1.00 to 0.80, specificity ranged from 1.00 to 0.42, false positive ranged from 0 to 58%, and false negatives ranged from 0 to 20%. At the 0.5% Federal threshold level, the observed sensitivity ranged from 1.00 to 0.94, specificity ranged from 1.00 to 0.5, false positives ranged from 0 to 11.1%, and false negatives ranged from 0 to 20%. The observed false positive and false negative rates for all three kits were found to be significantly lower than those reported in a previous study. These results indicate that the kits perform very well at the Federal threshold, with two of the kits having false negative rates below 12.5% and false positive rates of 3.13%. These results indicate that these two kits would probably be acceptable screening tests for lead in paint.

  7. SU-E-I-76: Matching Primary and Scattered X-Ray Spectra for Use in Calculating the Diagnostic Radiation Index of Protection

    SciTech Connect (OSTI)

    Pasciak, A [University of Tennessee Medical Center, Knoxville, TN (United States); Jones, A [MD Anderson Cancer Center, Houston, TX (United States); Wagner, L [UT Medical School, Houston, TX (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Lightweight lead-free or lead-composite protective garments exploit k-edge interactions to attenuate scattered X-rays. Manufacturers specify the protective value of garments in terms of lead equivalence at a single kVp. This is inadequate, as the protection provided by such garments varies with radiation quality in different use conditions. We present a method for matching scattered X-ray spectra to primary X-ray spectra. The resulting primary spectra can be used to measure penetration through protective garments, and such measurements can be weighted and summed to determine a Diagnostic Radiation Index for Protection (DRIP). Methods: Scattered X-ray spectra from fluoroscopic procedures were modeled using Monte Carlo techniques in MCNP-X 2.7. Data on imaging geometry, operator position, patient size, and primary beam spectra were gathered from clinical fluoroscopy procedures. These data were used to generate scattered X-ray spectra resulting from procedural conditions. Technical factors, including kV and added filtration, that yielded primary X-ray spectra that optimally matched the generated scattered X-ray spectra were identified through numerical optimization using a sequential quadratic programming (SQP) algorithm. Results: The primary spectra generated with shape functions matched the relative flux in each bin of the scattered spectra within 5%, and half and quarter-value layers matched within 0.1%. The DRIP for protective garments can be determined by measuring the penetration through protective garments using the matched primary spectra, then calculating a weighted average according to the expected clinical use of the garment. The matched primary spectra are specified in terms of first and second half-value layers in aluminum and acrylic. Conclusion: Lead equivalence is inadequate for completely specifying the protective value of garments. Measuring penetration through a garment using full scatter conditions is very difficult. The primary spectra determined in this work allow for practical primary penetration measurements to be made with equipment readily available to clinical medical physicists.

  8. Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

    SciTech Connect (OSTI)

    Mark Burdis; Neil Sbar

    2007-03-31T23:59:59.000Z

    The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a pinhole. (4) Improvements have also been made to the overall product to enhance the appearance and market acceptability. These include: (i) increasing the active electrochromic area to enable window manufacturers to install the SageGlass{reg_sign} IGU's into a variety of different framing systems, (ii) implementing a Pb free solder system for the electrical interconnections, (iii) development of a wire routing scheme to allow installation of SageGlass{reg_sign} units into a variety of different framing systems. This project has advanced the development of electrochromic glazing significantly, thereby advancing the introduction of the product and all the benefits of such a technology.

  9. Challenges in the Packaging of MEMS

    SciTech Connect (OSTI)

    Malshe, A.P.; Singh, S.B.; Eaton, W.P.; O'Neal, C.; Brown, W.D.; Miller, W.M.

    1999-03-26T23:59:59.000Z

    The packaging of Micro-Electro-Mechanical Systems (MEMS) is a field of great importance to anyone using or manufacturing sensors, consumer products, or military applications. Currently much work has been done in the design and fabrication of MEMS devices but insufficient research and few publications have been completed on the packaging of these devices. This is despite the fact that packaging is a very large percentage of the total cost of MEMS devices. The main difference between IC packaging and MEMS packaging is that MEMS packaging is almost always application specific and greatly affected by its environment and packaging techniques such as die handling, die attach processes, and lid sealing. Many of these aspects are directly related to the materials used in the packaging processes. MEMS devices that are functional in wafer form can be rendered inoperable after packaging. MEMS dies must be handled only from the chip sides so features on the top surface are not damaged. This eliminates most current die pick-and-place fixtures. Die attach materials are key to MEMS packaging. Using hard die attach solders can create high stresses in the MEMS devices, which can affect their operation greatly. Low-stress epoxies can be high-outgassing, which can also affect device performance. Also, a low modulus die attach can allow the die to move during ultrasonic wirebonding resulting to low wirebond strength. Another source of residual stress is the lid sealing process. Most MEMS based sensors and devices require a hermetically sealed package. This can be done by parallel seam welding the package lid, but at the cost of further induced stress on the die. Another issue of MEMS packaging is the media compatibility of the packaged device. MEMS unlike ICS often interface with their environment, which could be high pressure or corrosive. The main conclusion we can draw about MEMS packaging is that the package affects the performance and reliability of the MEMS devices. There is a gross lack of understanding between the package materials, induced stress, and the device performance. The material properties of these packaging materials are not well defined or understood. Modeling of these materials and processes is far from maturity. Current post-package yields are too low for commercial feasibility, and consumer operating environment reliability and compatibility are often difficult to simulate. With further understanding of the materials properties and behavior of the packaging materials, MEMS applications can be fully realized and integrated into countless commercial and military applications.

  10. Harsh environments electronics : downhole applications.

    SciTech Connect (OSTI)

    Vianco, Paul Thomas

    2011-03-01T23:59:59.000Z

    The development and operational sustainment of renewable (geothermal) and non-renewable (fossil fuel) energy resources will be accompanied by increasingly higher costs factors: exploration and site preparation, operational maintenance and repair. Increased government oversight in the wake of the Gulf oil spill will only add to the cost burden. It is important to understand that downhole conditions are not just about elevated temperatures. It is often construed that military electronics are exposed to the upper limit in terms of extreme service environments. Probably the harshest of all service conditions for electronics and electrical equipment are those in oil, gas, and geothermal wells. From the technology perspective, advanced materials, sensors, and microelectronics devices are benefificial to the exploration and sustainment of energy resources, especially in terms of lower costs. Besides the need for the science that creates these breakthroughs - there is also a need for sustained engineering development and testing. Downhole oil, gas, and geothermal well applications can have a wide range of environments and reliability requirements: Temperature, Pressure, Vibration, Corrosion, and Service duration. All too frequently, these conditions are not well-defifined because the application is labeled as 'high temperature'. This ambiguity is problematic when the investigation turns to new approaches for electronic packaging solutions. The objective is to develop harsh environment, electronic packaging that meets customer requirements of cost, performance, and reliability. There are a number of challenges: (1) Materials sets - solder alloys, substrate materials; (2) Manufacturing process - low to middle volumes, low defect counts, new equipment technologies; and (3) Reliability testing - requirements documents, test methods and modeling, relevant standards documents. The cost to develop and sustain renewable and non-renewable energy resources will continue to escalate within the industry. Downhole electronics can provide a very cost-effective approach for well exploration and sustainment (data logging). However, the harsh environments are a 'game-changer' in terms defining materials, assembly processes and the long-term reliability of downhole electronic systems. The system-level approach will enable the integration of each of these contributors - materials, processes, and reliability - in order to deliver cost-effective electronics that meet customer requirements.

  11. High-Temperature High-Power Packaging Techniques for HEV Traction Applications

    SciTech Connect (OSTI)

    Elshabini, Aicha [University of Idaho; Barlow, Fred D. [University of Idaho

    2006-11-01T23:59:59.000Z

    A key issue associated with the wider adoption of hybrid-electric vehicles (HEV) and plug in hybrid-electric vehicles (PHEV) is the implementation of the power electronic systems that are required in these products. One of the primary industry goals is the reduction in the price of these vehicles relative to the cost of traditional gasoline powered vehicles. Today these systems, such as the Prius, utilize one coolant loop for the engine at approximately 100 C coolant temperatures, and a second coolant loop for the inverter at 65 C. One way in which significant cost reduction of these systems could be achieved is through the use of a single coolant loop for both the power electronics as well as the internal combustion engine (ICE). This change in coolant temperature significantly increases the junction temperatures of the devices and creates a number of challenges for both device fabrication and the assembly of these devices into inverters and converters for HEV and PHEV applications. Traditional power modules and the state-of-the-art inverters in the current HEV products, are based on chip and wire assembly and direct bond copper (DBC) on ceramic substrates. While a shift to silicon carbide (SiC) devices from silicon (Si) devices would allow the higher operating temperatures required for a single coolant loop, it also creates a number of challenges for the assembly of these devices into power inverters. While this traditional packaging technology can be extended to higher temperatures, the key issues are the substrate material and conductor stability, die bonding material, wire bonds, and bond metallurgy reliability as well as encapsulation materials that are stable at high operating temperatures. The larger temperature differential during power cycling, which would be created by higher coolant temperatures, places tremendous stress on traditional aluminum wire bonds that are used to interconnect power devices. Selection of the bond metallurgy and wire bond geometry can play a key role in mitigating this stress. An alternative solution would be to eliminate the wire bonds completely through a fundamentally different method of forming a reliable top side interconnect. Similarly, the solders used in most power modules exhibit too low of a liquidus to be viable solutions for maximum junction temperatures of 200 C. Commonly used encapsulation materials, such as silicone gels, also suffer from an inability to operate at 200 C for extended periods of time. Possible solutions to these problems exist in most cases but require changes to the traditional manufacturing process used in these modules. In addition, a number of emerging technologies such as Si nitride, flip-chip assembly methods, and the elimination of base-plates would allow reliable module development for operation of HEV and PHEV inverters at elevated junction temperatures.