Study of a failure mechanism during UIS switching of planar PT-IGBT with current sense cell

IGBT with sense emitter cells are used in power applications where current sensing or feedback is needed to guarantee safe operation of the switching device. In this paper we show, by experimental measurements and simulations, how the coupling of undesired voltages to the sense cell that is disconnected from the main IGBT emitter is able to trigger the latch-up of the entire device during inductive switching leading to its failure. Being able to reproduce the failure phenomenon by 2D simulations we are able to identify the possible physical cause of this phenomenon.