Improving the power cycling performance of the emitter contact of IGBT modules: Implementation and evaluation of stitch bond layouts

The emitter (front metallization) of IGBTs is contacted by wire bonding. In this study, the influence of the wirebond layout on the power cycling performance of IGBT modules is investigated. Stitch bonding is implemented to modify the wirebond layout of the emitter contact. The different layouts are subjected to power cycling tests. For a better understanding of the experimental results, electrical and thermo-mechanical FEM simulations are run and the current distribution and induced mechanical stress is discussed. Based on the results of this study, the emitter contact of the new HiPak module platform is designed.