Because of the need for electronics use at temperatures beyond 150°C, new high temperature interconnection technologies emerge, like silver sintering and copper wire bonding. In the project PROPOWER inverter modules with IGBTs and diodes mounted on DBC substrates were investigated as a prototype. Analyses were made to study the effects of the new interconnect technologies on fatigue failure. It is one basic question for the replacement of solders by sinter silver to what extend the failure behaviour depends on the kind of loading, that means passive thermal cycling versus active thermal cycling, and how it relates to solder fatigue failure. These questions were addressed by passive thermal cycling and in particular by different kinds of power cycling. Failure modes different from those observed with traditional interconnection technologies were detected. Finite element (FE-) analyses were made to understand the thermo-mechanical stresses, which cause these failures. To simulate the power cycle loading most realistic, coupled electro-thermal-mechanical analyses were carried out which are in the focus of this paper. The simulation results are compared to failures found by testing.

The recent developments in power semiconductor devices and increasing demands on reliability as well as on operation performance require innovative package technologies. Such a novel package technique based on a Planar Interconnect Technology (SiPLIT®) for power modules is introduced in this work. This package features thick Cu interconnects on a high-reliable insulating film for power semiconductor chip top contacts. Due to the conductor structure and contact technology, on-resistance and stray inductances are very low compared to state-of-the-art Al wire bonds. In addition, large area contacting improves the power cycling capability and surge current robustness significantly. These remarkable properties have been verified on several prototype modules where the manufacturing process has also been optimised in terms of cost-effectiveness, system integration and maturity for series production.