Research on the multi-physical field coupling modelling of IGBT package module and the effect of different structure failure interaction

Abstract

As the key package structure of insulated gate bipolar transistor (IGBT), the bond wire and solder layer are susceptible to failure due to alternating thermal stress, which can seriously change the operating characteristics of the package structure. In this paper, an electrical-thermal-mechanical multi-physical field coupling simulation model of IGBT including the fine bond wire and solder layer structure is constructed, whose equivalence and accuracy are verified by experiments and characteristic curves. Based on the constructed healthy model, the simulation results find that the fourth bond wire at the center location shows the highest temperature of 38.7 °C and the maximum mechanical stress of 55.5 MPa. Subsequently, the researches on single-structure failure and dual-structure simultaneous failure are carried out. The results show that bond wire failure only significantly affects its own operating characteristics, while solder layer failure affects itself and bond wire simultaneously. Moreover, the temperature rise due to the bond wire failure is more significant with an 86.8 % increase, while the mechanical stress change due to the solder layer failure is larger with a 178.2 % increase. The research in this paper can guide the reliability improvement of IGBT and the optimization of IGBT package structure.