Influence of Cu joining partner in transient liquid phase bonding

In power electronic assembly reliable interconnects are a major requirement and several efforts are made in order to assess suitable bonding technologies as a replacement for soft soldering. Transient liquid phase bonding with the Cu-Sn system could provide such a bonding solution. As in power electronic packaging several types of Cu with different grain morphology are in use, this study evaluates the growth of the intermetallic compounds Cu
3
Sn and Cu
5
Sn
6
depending on the type of Cu as a joining partner. Further, two types of joining processes are applied, one in a vacuum solder equipment and one in an induction heating furnace. The influence of the heating rate on the joint quality as well as on the phase formation is reported.