Characterization on the thermal field inside IGBT cells during switching based on TCAD modeling and Thermoreflectance imaging

Abstract

—Temperature characterization of power semiconductors is a hot topic in power electronics. Nevertheless, the transient temperature field inside an IGBT cell is highly difficult to measure. In this study, we presented a method combining metallographic technology and Thermoreflectance Imaging (TRI) to measure the temperature distribution inside IGBT cells during switching. First, the IGBT module was prepared to achieve a well longitudinal section and its electrical characteristics were verified. Subsequently, the double-pulse test was performed on the IGBT sample and the temperature distributions along the ground section were measured through TRI. The result indicates that the temperature along the cross-section can be observed through TRI. The experimental results are confirmed to be consistent with the TCAD simulations on electro-thermal behavior. The proposed method for the first time achieves the direct temperature measurement inside the cells of power devices on a micro-nano temporal-spatial scale, and it can serve as an effective tool for analysis like temperature evaluation, aging analysis and TCAD modeling.