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

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.