Thermal effects of packaging material and structure on high power white LEDs

The heat dissipation is a crucial factor for the reliability of high power white LEDs(HPLEDs). In this paper, a novel thermal pad structure is presented for HPLEDs, a theoretic thermal transfer model is built to analyze the thermal transferring in LED component. Besides, the thermal simulations of the LED component with the typical or the novel thermal pad are conducted, the temperature distributions are obtained to assess the thermal performance of the LED components. Moreover, the material of the substrate is changed into FR4 to investigate the advantage of the novel thermal pad structure in LED component. The thermal conductivity gap between the thermal pad and the packaging material is recognized as the most important factor on the selection of thermal pad structure.