skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Interdiffusion and Formation of Intermetallic Compounds in High-Temperature Power Electronics Substrate Joints Fabricated by Transient Liquid Phase Bonding

Journal Article · · Microelectronics Reliability

Power electronics packages typically comprise a dielectric substrate bonded to a metal layer and attached to heat sinks using a low-thermal-conductivity solder. These multiple layers increase the effective thermal resistance of the package and are responsible for package failures under cyclic thermal loads. Bonding the aluminum nitride dielectric layer (AlN) directly to a low coefficient of thermal expansion (CTE) aluminum silicon carbide (AlSiC) cold plate using copper-aluminum (Cu-Al) transient liquid phase (TLP) bonding has been shown to improve the mechanical reliability of the power electronic packages while making the package more compact by bringing the cooling solutions closer to the devices. This study aims to characterize the Cu-Al bonds formed during the TLP bonding of AlSiC with three different power electronics substrates: pure aluminum nitride (AlN), aluminum (DBA), and copper (DBC). The material compositions and microstructures of the bonds were analyzed using scanning electron microscopy (SEM), x-ray spectroscopy (EDS), confocal scanning acoustic microscopy (C-SAM), and x-ray diffraction (XRD). ..alpha..-Al solid compound was identified as the dominant phase in AlN-AlSiC and Al-AlSiC, with a notable presence of SiC particles. In contrast, three intermetallic phases - ..theta..-CuAl2, ..eta..-CuAl, and ..gamma..'- Cu9Al4 - were observed in the Cu-AlSiC bond. A computational solid-state diffusion model was developed to predict the intermetallic compounds (IMCs) formed during Cu-Al TLP bonding in each system, which supported the observation that an initial Cu volume fraction of 20 % in the material layers produced a final bond composition of >95 % Al with minimal IMC growth. However, increased Cu concentrations produced higher concentration gradients, leading to increased growth of IMCs, Kirkendall voids, and interstitial cracks.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1897997
Report Number(s):
NREL/JA-5400-82870; MainId:83643; UUID:14f3ec49-3ddc-45f9-9579-ecc0bf0772cb; MainAdminID:67772
Journal Information:
Microelectronics Reliability, Vol. 137
Country of Publication:
United States
Language:
English

References (45)

Electric-Drive Vehicle Power Electronics Thermal Management: Current Status, Challenges, and Future Directions journal August 2021
An Approach to Deal With Packaging in Power Electronics journal May 2005
Design, Analysis, Comparison, and Experimental Validation of Insulated Metal Substrates for High-Power Wide-Bandgap Power Modules journal June 2020
Two-Phase Liquid Cooling for Thermal Management of IGBT Power Electronic Module journal March 2013
A review of mechanical properties of lead-free solders for electronic packaging journal March 2009
Review of microstructure and properties of low temperature lead-free solder in electronic packaging journal January 2020
Confirmation of Creep and Fatigue Damage in Pb/Sn Solder Joints journal June 1992
Technological aspects of silver particle sintering for electronic packaging journal February 2018
Identifying the Development State of Sintered Silver (Ag) as a Bonding Material in the Microelectronic Packaging Via a Patent Landscape Study journal April 2016
Low-Temperature Sintered Nanoscale Silver as a Novel Semiconductor Device-Metallized Substrate Interconnect Material journal September 2006
Low-Temperature Sintering with Nano-Silver Paste in Die-Attached Interconnection journal September 2007
Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials journal September 2010
Comparing the mechanical and thermal-electrical properties of sintered copper (Cu) and sintered silver (Ag) joints journal June 2021
Characterization and Reliability of Sintered Nanosilver Joints by a Rapid Current-Assisted Method for Power Electronics Packaging journal March 2014
Die Bonding of High Power 808 nm Laser Diodes With Nanosilver Paste journal August 2012
Reliability and Lifetime Prediction Model of Sintered Silver Under High-Temperature Cycling journal October 2022
Migration issues in sintered-silver die attaches operating at high temperature journal September 2013
Migration of Sintered Nanosilver Die-Attach Material on Alumina Substrate Between 250 $^{\circ}\hbox{C}$ and 400 $^{ \circ}\hbox{C}$ in Dry Air journal June 2011
Silver nanoparticle applications and human health journal December 2010
Cellular responses induced by silver nanoparticles: In vitro studies journal June 2008
Studies on the biocompatibility and the interaction of silver nanoparticles with human mesenchymal stem cells (hMSCs) journal March 2009
Reactive Sintering of Cu Nanoparticles at Ambient Conditions for Printed Electronics journal May 2020
Synthesis of copper conductive film by low-temperature thermal decomposition of copper–aminediol complexes under an air atmosphere journal November 2014
Copper conductive inks: synthesis and utilization in flexible electronics journal January 2015
Enhanced Heat Dissipation of High-Power Light-Emitting Diodes by Cu Nanoparticle Paste journal June 2019
Room temperature sintering of Cu-Ag core-shell nanoparticles conductive inks for printed electronics journal May 2019
Low-pressure micro-silver sintering with the addition of indium for high-temperature power chips attachment journal November 2021
Chip-Bonding on Copper by Pressureless Sintering of Nanosilver Paste Under Controlled Atmosphere journal March 2014
Overview of transient liquid phase and partial transient liquid phase bonding journal August 2011
A Review on Recent Advances in Transient Liquid Phase (TLP) Bonding for Thermoelectric Power Module journal February 2018
The effect of TLP bonding temperature on microstructural and mechanical property of joints made using FSX-414 superalloy journal June 2012
Microstructure evolution and mechanical properties of Cu/Sn/Ag TLP-bonded joint during thermal aging journal October 2018
Transient Liquid Phase Bonding of AlN to AlSiC for Durable Power Electronic Packages journal June 2018
Growth behavior of Cu/Al intermetallic compounds and cracks in copper ball bonds during isothermal aging journal March 2008
Formation and growth of Cu–Al IMCs and their effect on electrical property of electroplated Cu/Al laminar composites journal December 2016
Effect of Intermetallic Compounds on the Thermal and Mechanical Properties of Al–Cu Composite Materials Fabricated by Spark Plasma Sintering journal May 2019
Experimental Description of the Al-Cu Binary Phase Diagram journal May 2019
About the Al–Cu–Si isothermal section at 500°C and the stability of the ɛ-Cu15Si4 phase journal March 2009
Investigation of Formation and Growth Behavior of Cu/Al Intermetallic Compounds during Isothermal Aging journal January 2014
Intermetallic phase formation in diffusion-bonded Cu/Al laminates journal December 2010
Prediction of phase formation sequence and phase stability in binary metal‐aluminum thin‐film systems using the effective heat of formation rule journal October 1991
Critical review on friction stir welding of aluminium to copper journal April 2016
Microstructural evolution in the friction stir welded 6061 aluminum alloy (T6-temper condition) to copper journal February 2006
Synthesis and microstructural characterization of Al–Mg alloy–SiC particle composite journal June 2008
Effect of heat treatment on microstructure and interface of SiC particle reinforced 2124 Al matrix composite journal November 2013