Comparison of different technologies for the die attach of power semiconductor devices conducting active power cycling

Inhalt:
The three different die attach technologies soldering, silver sintering and transient liquid phase bonding (TLPB) were compared conducting active power cycling tests. The active power cycling method used was designed such that the temperature swing of the semiconductor die was held constant over the whole testing time. The TLPB interconnects consisting of the intermetallic phases Cu6Sn5 and Cu3Sn showed the highest life time followed by Ag sinter joints made applying a sintering pressure of 30 MPa showing almost the same life time. Even the pressure less sintered samples showed a much higher life time than the soldered interconnects made of SnAg3.5 solder. While the soldered samples failed due to solder fatigue, the silver sintered and TLPB samples showed failures like delaminations and cracks in the substrate rather than in the interconnects themselves.