A distributed thermal model of GaN HEMT considering nonlinear thermal conductivity and PCB effect

A distributed thermal model for analyzing the heat distribution of GaN high electron mobility transistor (HEMT) is presented in this paper. The thermal resistance calculation of multi-gate GaN HEMT with nonlinear thermal conductivity is derived. Considering the heat conduction of PCB and the nonlinear thermal conductivity, the model developed in COMSOL realizes the consistency between the simulation results and the measurement results. Based on the model, the surface and internal temperatures can be extracted for the thermal resistance calculation. The proposed method combined model simulation with numerical calculation will be helpful for designers to analyze the thermal distribution of transistors and the circuits.