Electro-Thermal Coupling Characteristics and Modeling of SiC MOSFET Modules under High Pulse Current Conditions

Silicon carbide (SiC) MOSFETs help to achieve high efficiency, high frequency, and high power density for power electronic converters. When applied in fields such as pulsed power supplies and solid-state circuit breakers, SiC MOSFETs will withstand instantaneous high pulse current shocks and significant temperature fluctuations. Thanks to high-temperature packaging technology, the working junction temperature of SiC MOSFETs can exceed 175 ℃. However, the electro-thermal coupling characteristics of SiC MOSFETs under high pulse current are not yet clear. In this paper, a nano-silver sintered half-bridge SiC MOSFET module is designed and fabricated, which allows SiC MOSFETs to operate at higher junction temperatures. Then an electro-thermal coupling model is established based on MATLAB/Simulink and COMSOL over a wide temperature range (25 ~ 375℃). Thus, the electro-thermal coupling characteristics of the SiC MOSFET module are studied in detail. Finally, some experiments are carried out to verify the model.