Transient Characteristic Analysis of IGBT Voltage Breakdown Failure

The electrical breakdown failure of insulated gate bipolar transistor(IGBT) is one of the common failure mechanisms. Because of the existence of stray inductance distributed inside the circuit and device, excessive voltage spike occurs during the turnoff transient, which leads to overvoltage breakdown. Based on the adiabatic process analysis of IGBT electric breakdown, the failure mechanism of IGBT electric breakdown is obtained. Because the IGBT module is composed of IGBT chip and anti-parallel diode, it is difficult to judge the fault location only by the failure waveform. Therefore, this paper analyzes the failure mode of IGBT chip and anti-parallel diode by opening the package observation and real-time observation by infrared thermal imager, which shows that the chip has stronger ability to withstand electric breakdown than diode and the failure location is smaller.