Optimization of wire connections design for power electronics

ESREF 2011 - 22nd European Symposium Reliability of Electron Devices, Failure Physics and Analysis, Bordeaux, FRANCE, 03-/10/2011 - 07/10/2011In automotive power electronics, low cost and reliability requirements both demand to optimize each part of the package in order to increase its life time during use. The wire bonding breakage accounts for one of the most common failures observed on power modules. In particular, the heel crack mechanism, mainly due to Joule self-heating, can occur in the module, leading to its death. Thus, the wire geometry design has to be set up to maximize its endurance. This paper presents an analytical method able to predict the optimal wire length regarding a wire displacement criterion. Finally, comparisons between experimental results and predictions of the analytical model are given