Thermal design and simulation analysis of GaN based MPS switching diode

Abstract

Merged PiN/Schottky power (hereinafter referred to as MPS) switching diode has the advantages of high blocking voltage, low leakage current, high switching speed, high current, low voltage and so on. Based on the above advantages, in modern society, the power of MPS switching diode is getting larger and larger, which is used in many fields, and almost all electrical energy converts into heat, so that the chip junction temperature rises rapidly, when the temperature exceeds the maximum allowable temperature, the MPS power switching diode will be damaged due to overheating, so heat dissipation is the key problem for MPS package. In this study, the heat sink is installed under the MPS diode, so heat can be exchanged with the surrounding environment by adopting to forced convection, and combined with high thermal conductivity material as insulating layer of the MPS diode substrate, so the heat generated can be dissipated in a timely manner. In this paper, aiming at the heat characteristics of high power MPS switching diode, a three-dimensional model of the MPS power switching diode is constructed by using three-dimensional drawing software Solid-Works. The diamond like carbon (DLC) film and aluminum oxide (Al2O3) film are respectively used as the insulating layers of the substrate, and the thermal analysis is carried out by ANSYS. Through changing the forced convection coefficient on the surface of the radiator, the relationship between the different convection coefficient and the maximum temperature of the device is obtained. In addition to thermal analysis, the temperature distribution of the device is obtained by infrared thermal imaging instrument test method.