Silver sinter joining and stress migration bonding for WBG die-attach

Power electronics play an important role in the generation-storage-distribution conversion cycle of the electric energy. Wide band gap semiconductors such as SiC and GaN have attracted many researchers recently because both of their excellent energy conversion efficiency and of capability of device downsizing. The performance of interconnection, especially die-attach, has one of the essential roles for achieving high performance. Among various proposals for die-attach materials and processes, Ag sinter joining is a promising method for power semiconductors as well as for power LEDs, providing excellent heat-resistance to achieve stable joint structures beyond 200 °C. This paper summarizes the present status of the Ag sinter joining and of the new bonding approach with Ag films.