As the technology downscales with superior power and increased package density, the thermal effects of the high power LED are significant. Thus, the operating junction temperature of the high power light emitting diodes has to be reduced. In this paper, evaluation on single chip high power light emitting was done. The prime motive of this work was to assess the effect of heat slug size on the junction temperature and stress of LED chip under natural convection condition at ambient temperature of 25°C. Two sizes of rectangular heat slug were used. Simulation was carried out using Ansys version 11. Input power of 0.1W and 1W was applied to LED. Simulated results indicated that a larger slug size is favorable for a lower operating junction temperature and stress of the LED chip.
