Investigation of thermal characteristics of a silicon-based LED packaging module

The thermal management of light-emitting diode (LED) packaging modules has become more important in the electronic industrials. High temperatures during lighting resulting in luminance decay, color temperature drift, life time decline and generally efficiency decrease. Low thermal resistance, low cost and high potential for mass production of Si, lead to improve its usage in LED packaging. For this issue, this paper proposes a silicon-based LED packaging module with thin gold sputtered layer on the top surface of silicon substrate and a bulk micro machined cavity on the other side. In two different configuration, LED die directly is mounted on flat surface and cup cavity of silicon with various area of Au layer and volume of cavity. Afterwards, by in-situ measuring the temperature of substrate and finite element simulation, the temperature distribution of silicon submount is evaluated. The results of experiment and simulation were very similar and confirm that heat conductivity of package which LED directly is mounted on flat surface is higher than one which LED mounted in cup cavity.