Fast and Distributed Thermal Model for Thermal Modeling of GaN Power Devices

A new thermal model based on a distributed and fast modeling approach for the modeling of gallium nitride (GaN) power devices is presented in this paper. The model is based on the application of Green's function theory to obtain an analytical solution of the heat conduction equation. The model comprises an accurate, spatially distributed, and fast algorithm that calculates a 2-D thermal response at the 2-D electron gas level of GaN power devices in the steady-state and the transient regime. In comparison with finite element method finite-element model simulations, the model achieves a significant reduction of the computational time while retaining very good accuracy. The model shows strong capabilities for thermal analysis with respect to parameters that have a significant impact on the thermal behavior. Moreover, the nonlinear effect associated with the temperature-dependent thermal conductivity is encompassed together with the impact of package and ambience. As a validation study, the thermal behavior of packaged GaN devices is experimentally characterized by means of infrared thermography. An excellent agreement between the model results and experiments is observed.