Comparison of Silver Sintered Assemblies on Non-DCB Substrates

Abstract:
Silver sintering technology has already been established as an alternative in power electronics to replace soldering on DCB. As different methods and processes for silver sintering are increasingly available, there is the posibility to diversify the substrate materials for silver sintering. Most research works on silver sintering uses direct copper bonded substrates (DCB) due to their thermal and electrical performance. Investigating silver sintering on alternative substrates like high-temperature stable PCBs, insulated metal substrates (IMS) and copper lead-frames can diversify possible applications in high power and high temperature operating conditions. High temperature stable embedded printed circuit boards are emerging as an alternative to ceramic-based inorganic substrates. Embedding of power electric chips with high power density to novel printed circuit boards requires reliable die attachment techniques. Establishing silver sintering on these materials can help solve the existing issues in the embedding of power chips into printed circuit boards. This research work presents the results of the silver sintered process developed on these non-DCB substrates using shear tests and metallographic cross sections. Thermal stresses after the assembly are characterized using warpage measurements using the digital image correlation technique (DIC). Finally the results achieved with different substrates are compared.