Failure Analysis of IGBT Bonding Wire Based on Multi-physics Coupling

As the core device of the power converter, IGBT modules is prone to aging failure failures. Mastering the failure mechanism and failure effect of IGBT modules is the basis for ensuring its reliable operation. Based on the analysis of the failure mechanism and multi-physical layer coupling of the IGBT module, this paper establishes the electric-thermal-force multi-physics coupling model of the IGBT module through ANSYS software, and studies the failure of the IGBT module bonding wire. Through the simulation analysis of the temperature distribution and thermal stress changes of the IGBT modules bonding wire under steady-state heat transfer and power cycling conditions, it is concluded that the bonding wire bears the greatest temperature and stress at the point where it is bonded to the chip; long-term stress fluctuations can easily lead to fatigue accumulation damage and bond fall failure; once the IGBT module has a bonding wire falling off failure, it will cause the temperature of the remaining bonding wire to increase, and the stress it bears will increase, thereby which accelerates the process of the remaining bonding wire falling off and accelerates the aging failure of the IGBT module.