Research on IGBT Bonding Wires Crack Propagation at the Macro and Micro Scales

Under the action of a complex and harsh working environment, the damage of the IGBT power module’s packaging interconnection structure is the primary failure mode. The crack propagation and the bonding interface and the bond point shedding in the bonding wires will seriously affect the device’s electrical interconnection function and heat dissipation ability, resulting in its performance degradation and failure. In this work, the formulation and application of a multiscale approach combined with a cohesive zone model (CZM) were proposed to investigate IGBT bonding wires’ crack propagation. Firstly, the cohesive force model’s principle considering fatigue damage accumulation is analyzed, and the degradation multiscale simulation method of the critical structure of the power module is studied. Secondly, further research on IGBT bonding wires’ degradation behavior is carried out based on the macro and micro scales. The IGBT power module key package structure’s defect evolution model is established to analyze the damage evolution process of the critical package structure. Finally, the accuracy of the model is verified by the experiment analysis. Such a multiscale, mechanism-based cohesive zone model offers a promising approach for modeling and understanding the rate-dependent fracture of IGBT bonding wire crack evolution.