Physics-of-Failure Based Lifetime Approach for Silver Sintered Power Modules in Power Cycling

Abstract:
New reliability requirements for power modules due to increasing demands, new materials and new technologies render classical empirical lifetime models not sufficient anymore. The paradigm change towards a physics-of-failure framework for lifetime modeling within power electronics offers the possibility to connect stress tests, microstructural analysis and finite element simulations. Especially, power cycling plays a crucial role as reliability test of power modules as it features the most application-like conditions with the semiconductor serving as heat source. To successfully model this stress test multidomain simulations are needed which comprise electro-thermal and thermo-mechanical setups. In this study, power cycling experiments with three different testing conditions are performed and followed by an in-detail microstructural analysis. Multidomain FE simulations accompany the experiments to determine the failure mechanisms and are used to generate the lifetime model.