Research on the Electro-Thermal–Mechanical Properties of IGBT Modules Under Different Bond Wire Failure Modes

Due to the coefficients of thermal expansion (CTE) mismatch between various materials, the bond wire of insulated gate bipolar transistor (IGBT) module is prone to heel-cracking or lift-off failure under power cycling, which will affect the performance of the module. In this article, an electro-thermal-mechanical multiphysics coupling model was constructed for IGBT module, and the accuracy of the model was validated by steady-state conduction experiment. Based on the simulation model, the characteristics of IGBT module were further simulated under the normal state conduction operation, and the results showed that the stress of the middle bond position on a single bond wire is higher. Then, the research on the influence of heel-cracking and lift-off failure of the bond wire was carried out. The simulation results showed that the heel-cracking failure of the bond wire will cause obvious effect, in which the increase stress can be as high as 77.4 MPa. When the bond wires are detached one by one until five bond wires were lifted off, the temperature in the remaining bond wires increases by
$48.7~^{\circ }$
C, which has a significant impact on the module. The research in this article can provide the basis for improving the reliability of IGBT module and the optimization of module package design.