Thermal simulation and analysis of flat surface flip-chip high power light-emitting diodes

Abstract

Conventional GaN-based flip-chip light-emitting diodes (CFC-LEDs) use Au bumps to contact the LED chip and Si submount, however the contact area is constrained by the number of Au bumps, limiting the heat dissipation performance. This paper presents a flat surface high power GaN-based flip-chip light emitting diode (SFC-LED), which can greatly improve the heat dissipation performance of the device. In order to understand the thermal performance of the SFC-LED thoroughly, a 3-D finite element model (FEM) is developed, and ANSYS is used to simulate the thermal performance. The temperature distributions of the SFC-LED and the CFC-LED are shown in this article, and the junction temperature simulation values of the SFC-LED and the CFC-LED are 112.80 °C and 122.97 °C, respectively. Simulation results prove that the junction temperature of the new structure is 10.17 °C lower than that of the conventional structure. Even if the CFC-LED has 24 Au bumps, the thermal resistance of the new structure is still far less than that of the conventional structure. The SFC-LED has a better thermal property.