High-Accuracy Fatigue Evaluation of Power Devices by Multi-Coupled Analysis

To calculate power semiconductor device fatigue with high accuracy, multiphysics analysis comprising electrical, heat, and stress analyses is presented. Power semiconductor devices (e.g., IGBTs) have been widely used in various applications. In particularly, the power semiconductor device (IGBT) becomes important component in vehicle applications. There is a high demand for compact and high-power capacity next-generation vehicles such as electric vehicles and hybrid vehicles. However, it causes the problem such as thermal stress. The reliability of power semiconductor devices has to be investigated by carrying out highly accurate simulations before developing IGBTs. In this paper, the electrical conductivity in silicon (IGBT) is considered as the material parameter. The semiconductor resistance is calculated by voltage distributions in the semiconductor. Comparing the conductivity constant case with the conductivity variation case, we examine the effects of the electrical characteristics of the semiconductor on fatigue.