A Wire-less SiC Power Module Using Flip-Chip Sintering Method

As SiC devices move towards lower specific RDS(on) and higher current density, traditional wire bonding SiC power modules are facing serious challenges in thermal management. The top-side of the SiC device of the double-sided cooling (DSC) power module uses a metal surface interconnection instead of the bonding wire point interconnection of the single-sided cooling (SSC) power module, which can effectively improve the current carrying capacity of the devices and significantly reduce the device junction temperature. However, the fragile interconnection structure on the top-side of the SiC devices of the DSC power modules will endure high thermomechanical stress from the upper largearea substrate, leading to significant thermal-mechanical reliability concerns. This paper proposes a flip-chip sintering interconnection method for DSC power modules which strengthens the mechanical interconnection structure between the top-side of the SiC device and the upper substrate. Simultaneously, it further improves the double-sided heat dissipation efficiency and current carrying capacity of the SiC device. Compared with the traditional DSC power modules, the maximum junction temperature of the SiC device of the flip-chip double-sided cooling (FCDSC) power modules is reduced by 14.2%, the effective interconnection area is increased by 60.5%, the maximum thermomechanical stress of the SiC device is reduced by 11.0%, and the maximum current carrying capacity is increased by 5.5%.