TY - JOUR
T1 - Effect of Gold on the Microstructural Evolution and Integrity of a Sintered Silver Joint
AU - Muralidharan, Govindarajan
AU - Leonard, Donovan N.
AU - Meyer, Harry M.
N1 - Publisher Copyright:
© 2016, The Minerals, Metals & Materials Society (outside the USA).
PY - 2017/7/1
Y1 - 2017/7/1
N2 - There is a need for next-generation, high-performance power electronic packages and systems employing wide-bandgap devices to operate at high temperatures in automotive and electric grid applications. Sintered silver joints are currently being evaluated as an alternative to Pb-free solder joints. Of particular interest is the development of joints based on silver paste consisting of nano- or micron-scale particles that can be processed without application of external pressure. The microstructural evolution at the interface of a pressureless-sintered silver joint formed between a SiC die with Ti/Ni/Au metallization and an active metal brazed (AMB) substrate with Ag metallization at 250°C has been evaluated using scanning electron microscopy (SEM), x-ray microanalysis, and x-ray photoelectron spectroscopy (XPS). Results from focused ion beam (FIB) cross-sections show that, during sintering, pores in the sintered region near to the Au layer tend to be narrow and elongated with long axis oriented parallel to the interface. Further densification results in formation of many small, relatively equiaxed pores aligned parallel to the interface, creating a path for easy crack propagation. X-ray microanalysis results confirm interdiffusion between Au and Ag and that a region with poor mechanical strength is formed at the edge of this region of interdiffusion.
AB - There is a need for next-generation, high-performance power electronic packages and systems employing wide-bandgap devices to operate at high temperatures in automotive and electric grid applications. Sintered silver joints are currently being evaluated as an alternative to Pb-free solder joints. Of particular interest is the development of joints based on silver paste consisting of nano- or micron-scale particles that can be processed without application of external pressure. The microstructural evolution at the interface of a pressureless-sintered silver joint formed between a SiC die with Ti/Ni/Au metallization and an active metal brazed (AMB) substrate with Ag metallization at 250°C has been evaluated using scanning electron microscopy (SEM), x-ray microanalysis, and x-ray photoelectron spectroscopy (XPS). Results from focused ion beam (FIB) cross-sections show that, during sintering, pores in the sintered region near to the Au layer tend to be narrow and elongated with long axis oriented parallel to the interface. Further densification results in formation of many small, relatively equiaxed pores aligned parallel to the interface, creating a path for easy crack propagation. X-ray microanalysis results confirm interdiffusion between Au and Ag and that a region with poor mechanical strength is formed at the edge of this region of interdiffusion.
KW - Au–Ag interdiffusion
KW - Sintered Ag
KW - pore connectivity
KW - pore shape
UR - http://www.scopus.com/inward/record.url?scp=85008487956&partnerID=8YFLogxK
U2 - 10.1007/s11664-016-5216-8
DO - 10.1007/s11664-016-5216-8
M3 - Article
AN - SCOPUS:85008487956
SN - 0361-5235
VL - 46
SP - 4085
EP - 4092
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
IS - 7
ER -