Gate Oxide Breakdown in IGBT Modules Due to Bonding Wires Lift-Off

In this paper, a rarely reported failure mechanism of multichip IGBT module caused by the aging of the emitter bonding wires on a single IGBT chip is revealed. It is found that when the emitter bonding wires bonded on a single chip are all electrically disconnected due to lift-off or cracking, there is a chance that the chip gate can be broken down when the device is blocking busbar voltage and eventually leading to the malfunction of the entire module. Due to the internal parasitics distribution, an over-voltage might be applied across the E-G terminals resulting in a breakdown on the gate oxide layer of device. In the paper, the failure mechanism of IGBT’s gate overvoltage is studied via equivalent circuit modeling and followed by simulation and experiment validations.