Effect of process and surface metallization on interfacial reaction of siliver sintered joint for power devices

Abstract:
In this paper, the interfacial reactions and quality of silver sintered joints with three different surface finishes of Cu, Ag and electroless Ni-immersion Gold (ENIG) between large area die and Direct Bonding Copper (DBC) substrate were evaluated. The sintering process is operated with a certain range of pressure, temperature and the time factor. The comparison of the porosity of the sintered silver layer under different conditions showed that prolonging the time can effectively increase the density, and increasing the pressure can significantly reduce the thickness of the silver layer and promote the densification reaction. The results of the reliability test showed that the silver sintered joint can pass the power cycle test of the module, and showed a significant increase compared with the solder joints.