Monitoring IGBT Module Bond Wire Fatigue Use Turn-Off Time

Bond wire fatigue is a prominent problem in the reliability of IGBT modules and power electronic converter. The fatigue evaluation method of IGBT bond wire based on non-invasive methods has attracted a lot of attention. The paper proposes a fatigue evaluation method for bond wire based on IGBT turn-off time. At the chip level, the input capacitance of gate before and after bond wire fatigue is different, resulting in changes in multiple stages of the IGBT turn-off process. Based on the above conclusions, the paper constructs a fatigue evaluation model for bond wire using IGBT turn-off time, fully considering the impact of changes in collector current. In addition, the applicability of the turn-off time extraction method based on Kelvin terminals is verified by the three-phase power cycling experimental platform. It also can be found that the IGBT bond wire fatigue monitoring method based on turn off time has high sensitivity and convenient extraction, and can be used for reliability online monitoring of power electronic converters.