Assessment of uni-axial mechanical stress on Trench IGBT under severe operating conditions: a 2D physically-based simulation approach

Power devices in their environmental application are submitted in addition to the electrical, thermal, radiation and other kinds of stresses to mechanical stress. In our study, we focus in combination of electrical, thermal and mechanical stresses of a Trench Gate punch through insulated gate bipolar transistor during switching transients. With a 2D physically-based finite elements simulator, we can achieve electro-thermo-mechanical simulations. Two operating configurations have been analyzed: inductive switching and short circuit. Simulation results show that whereas the mechanical stress has low effect on the current tail during clamped inductive switching turn off and on the sustain voltage during unclamped inductive switching, the saturation current during short-circuit operating is strongly affected by external mechanical stress depending on its level, direction and nature (compressive or tensile).