Study on thermal buffering effect of phase change material on press- pack IGBT

Abstract

Power electronic devices such as metal oxide semiconductor field-effect transistors (MOSFETs), insulating gate bipolar transistors (IGBTs) have high power density and weak power surge handing capability. In order to improve the power surge handing capability of devices, some scholars have proposed the scheme of using active cooling technology and oversize heat sinks. However, due to the thermal resistance between the heat source and the heat sink, the chip temperature may have exceeded the maximum junction temperature before the heat transfers to the heat sink. Therefore, in order to enable power electronic equipment to withstand the thermal effects of power surge, this paper proposes to integrate phase change materials (PCMs) into IGBT molybdenum (Mo) plate. During power surge, PCM absorbs a large amount of heat for phase change while the temperature remains constant. Therefore, the PCM can be kept at a lower temperature, which facilitates heat transfer from the chip to outside. Furthermore, PCM can reduce the temperature rise rate of the chip, and ensure that the device works properly during power surge. In this paper, the influence of integrating PCM on normal working devices is analyzed. Furthermore, the thermal buffering effect of PCM under different power surges, and the influence of integrated structure of PCM on the thermal buffering effect of PCM are studied by finite element method. The simulation model is established in the finite element simulation software COMSOL Multiphysics. The simulation results show that the power surge handing capability of the press- pack IGBT device integrated with PCM is improved significantly.