Investigation of Deformation Fluctuation of IGBT Chips Under Switching Conditions Using the Dynamic Field Reconstruction Method

Insulated gate bipolar transistor (IGBT) chips are crucial core components in power electronic modules. It is of great significance to investigate the deformation characteristics of IGBT chips induced by the electro-thermal-mechanical coupling. In this article, a field reconstruction technique based on scanning laser displacement measurement is developed to accurately capture the dynamic deformation field distribution on the surface of IGBT chips. Based on this method, a comprehensive investigation of the impacts of switching conditions on the deformation fluctuation characteristics of IGBT chips is implemented. The results indicate the middle region of the IGBT chip suffers from a relatively larger deformation compared to the edge area. In particular, the largest deformation fluctuation occurs near the heel of bonding wires. In addition, it is also observed that the deformation fluctuation is negatively correlated with the switching frequency, meanwhile positively related to load amplitude, and shows a trend of increasing first, and then, decreasing with duty cycle. This work provides an intuitive and effective method for the dynamic deformation field characterization of IGBT chips. Furthermore, the outcomes obtained in this article can also provide confident evidence and important data to facilitate more precise reliability analysis and evaluation for power electronic modules.