Lifetime prediction of IGBT modules for traction applications

Bond wire lift-off caused by low-cycle fatigue is one among the dominant failure mechanisms of modern high power Insulated Gate Bipolar Transistors multichip modules used in traction applications. A model is proposed which is calibrated basing on data from accelerated tests and which predicts quantitatively the lifetime of devices submitted to cyclic loads as they are encountered in current converters of railway systems. It assumes linear accumulation of the thermal-cycle fatigue damage and takes into account the redundancy of the bond wires within a complex multichip module.