Remaining Useful Lifetime estimation for Electronic Power modules using an analytical degradation model

Abstract

Power electronic modules undergo electro-thermal stresses due to power losses that lead to several kinds of degradations, and finally to failure. In order to prevent power electronic module failure, one should assess its state of health in real-time operation. For this purpose, Prognostics and Health Management (PHM) approach could be a promising tool for reliability evaluation for an IGBT device. The Insulated Gate Bipolar Transistor is a three-terminal power semiconductor device used as an electronic switch which combines high efficiency and fast switching. In this paper, an analytical model is proposed that describes the metallization to wire-bond contact resistance. This model computes the crack length and then using online measurement the rate of crack propagation is computed and used to predict the future crack lengths with the assumption of linearity in crack propagation. The main failure mechanism of the IGBT device in this paper is the crack propagation in the wire-bond interconnection. The usual aging indicator of such damages is the voltage between the collector and the emitter of current (VCE) that increases with degradation. The analytical model is related to this indicator and it is based on the contact resistance theory and constriction current lines. The proposed model is hence used to build a prognostics model for estimating the remaining useful lifetime (RUL) of IGBT power modules. The prognostics model is illustrated using aging data coming from accelerated power cycling tests with different stress conditions. The first cycling test is under the conditions of stress duration ton = 3sec and junction temperature swing amplitudes ΔTj = 110 ºC and the second cycling test is under ton = 3sec and ΔTj = 90ºC. Results show a prognostics capability.