Thermal analysis of GaN-based LEDs using the finite element method and unit temperature profile approach

This paper reports on the thermal modelling of GaN-based LEDs. The theoretical calculation was made by combining an analytical simulation employing the Unit Temperature Profile Approach (UTPA) and Finite Element Method (FEM). An interfacing process was made by the optimization of the modelling input parameters used in the analytical simulator. The calculated temperatures of the LED chip inside the epoxy package was compared with the experimentally measured data and the optimized heat transfer coefficients were extracted. The extracted parameters were implemented into the numerical thermal calculation of the package surface using FEM. By the effective interfacing process between the two modelling tools, it is demonstrated that the analytical simulator can be utilized for the accurate prediction of the surface temperatures of LED packaging with non-flat surface.