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Title: The Creep Behavior of In-Ag Eutectic Solder Joints

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director, Office of Energy Research
OSTI Identifier:
895578
Report Number(s):
LBNL-41828
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Electronic Materials; Journal Volume: 28; Journal Issue: 1; Related Information: Journal Publication Date: Jan 1999
Country of Publication:
United States
Language:
English

Citation Formats

Reynolds, H.L., Kang, S.H., and Morris, J.W. The Creep Behavior of In-Ag Eutectic Solder Joints. United States: N. p., 1998. Web.
Reynolds, H.L., Kang, S.H., & Morris, J.W. The Creep Behavior of In-Ag Eutectic Solder Joints. United States.
Reynolds, H.L., Kang, S.H., and Morris, J.W. Fri . "The Creep Behavior of In-Ag Eutectic Solder Joints". United States. doi:.
@article{osti_895578,
title = {The Creep Behavior of In-Ag Eutectic Solder Joints},
author = {Reynolds, H.L. and Kang, S.H. and Morris, J.W.},
abstractNote = {},
doi = {},
journal = {Journal of Electronic Materials},
number = 1,
volume = 28,
place = {United States},
year = {Fri May 01 00:00:00 EDT 1998},
month = {Fri May 01 00:00:00 EDT 1998}
}
  • Creep deformation behavior was measured for 60--100 {micro}m thick solder joints. The solder joints investigated consisted of: (1) non-composite solder joints made with eutectic Sn-Ag solder, and (2) composite solder joints with eutectic Sn-Ag solder containing 20 vol.%, 5 {micro}m diameter in-situ Cu{sub 6}Sn{sub 5} intermetallic reinforcements. All creep testing in this study was carried out at room temperature. Qualitative and quantitative assessment of creep deformation was characterized on the solder joints. Creep deformation was analyzed using a novel mapping technique where a geometrical-regular line pattern was etched over the entire solder joint using excimer laser ablation. During creep, themore » laser-ablation (LA) pattern becomes distorted due to deformation in the solder joint. By imaging the distortion of laser-ablation patterns using the SEM, actual deformation mapping for the entire solder joint is revealed. The technique involves sequential optical/digital imaging of the deformation versus time history during creep. By tracing and recording the deformation of the LA patterns on the solder over intervals of time, local creep data are obtained in many locations in the joint. This analysis enables global and localized creep shear strains and strain rate to be determined.« less
  • The addition of 3 wt.% Ag to In results in a eutectic composition with improved mechanical properties while only slightly lowering the melting temperature. Steady-state creep properties of In-Ag eutectic solder joints have been measured using constant load tests at 0, 30, 60, and 90 C. Constitutive equations are derived to describe the creep behavior. The data are well represented by an equation of the form proposed by Dorn: a power-law equation applies to each independent creep mechanism. Two parallel mechanisms were observed for the In-Ag eutectic joints. The high-stress mechanism is a bulk mechanism with a thermal dependence dominatedmore » by the thermal dependence of creep in the In-rich matrix. The low-stress mechanism is a grain boundary mechanism. Results of this work are discussed with regard to creep behavior of typical eutectic systems.« less
  • Solidification of eutectic Sn-Ag solder, with and without Cu{sub 6}Sn{sub 5} composite reinforcements, on copper substrates, was investigated at two different cooling rates. The size, orientation, randomness, and overall morphology of the dendritic microstructure were examined as a function of cooling rate. Cu{sub 6}Sn{sub 5} particle reinforcements were found to act as nucleation sites for dendrites, in addition to sites on the substrate/solder interface. The mechanical properties of these solders were also examined as a function of cooling rate. Solder joints with a lower load-carrying area were found to exhibit higher shear strength, but reduced ductility when compared to soldermore » joints with more load carrying area.« less
  • No abstract prepared.