Localization and Detection of Bond Wire Faults in Multichip IGBT Power Modules

Multichip insulated gate bipolar transistor (mIGBT) power modules (PMs) degrade over power cycling. Bond wire lift-off is one of the major failure modes. This article presents a technique to diagnose bond wire lift-off by analyzing the on-state voltages across collector and emitter terminals and the voltages across collector and Kelvin emitter terminals. The proposed method can indicate the first lift-off out of 37 bond wires in a mIGBT. The main novelty of the proposed technique is that it can locate the chip that has bond wire lift-off(s). In addition, the temperature dependence of the proposed approach is negligible. The article describes the proposed technique in detail and shows results and discussions based on practical tests which are carried out on two mIGBT PMs with different packages.