A parametric study of a typical high power LED package to enhance overall thermal performance

LED is the revolution in the illumination industry due to its great performance of solid state lighting, environment friendly working, power saving and long lasting life. But dissipation of heat generated and subsequently the thermal management in the LED package is a challenge. A steady state thermal analysis of a typical high power LED model with power dissipation values ranging from 1– 3W, consisting of LED chip, submount, heat slug and silicone enclosure is carried out in order to minimize the junction temperature of LED system. A three dimensional finite element model of the LED package is solved numerically and simulated using ANSYS Workbench to fulfill the purpose. Junction temperature is a critical parameter which affects the efficiency, reliability and lifetime of the LED. In order to minimize the junction temperature, a parametric study is carried out. This study consists of critical geometric parameters such as size of the die, thickness of the submount adhesive, width and thickness of lead frame and height of encapsulation as well as thermal properties of die attach, submount adhesive and encapsulation covering most common adhesive, die attach and encapsulant materials. Recommendations are provided regarding both geometric and process parameters to minimize the junction temperature which will improve the overall reliability and performance of the LED package.