An Electrothermal Model for IGBT Based on Finite Differential Method

In this article, a practical electrothermal SPICE model is proposed based on finite differential method. Other than the conventional Fourier model and the Hefner model, the distribution of excess carriers can be accurately solved by a finite differential method in the SPICE simulation tool. In this method, the electrothermal behavior of the device is modeled by using a semi-mathematic model. In order to verify the modeling results, a self-packaging insulated-gate bipolar transistor (IGBT) module is tested in both static characteristics and dynamic characteristics, and the simulation results of the presented model fit well with the experimental results under different junction temperatures. More importantly, the finite differential method provided in this article is an approach for modeling bipolar devices, and it can also be applied to model widebandgap devices such as a SiC IGBT and a SiC BJT.