Numerical Study of Thermal Behavior in Alternating Current Light-Emitting Diodes

Abstract

The thermal characteristics of an alternating current light-emitting diode (AC LED) chip based on a three-dimensional unsteady numerical simulation are discussed. In this model, the difficulties due to the tiny scale and extra-low aspect ratio of the AC LED microchip geometry are resolved. A time lag between the maximum forward voltage and the highest mean junction temperature is observed. The influence of different input power frequencies on the thermal fields is also investigated for AC LEDs with 600 μm × 600 μm area. A numerical simulation of the junction temperature distributions shows that the AC LED has a better performance under a higher frequency than under a lower frequency.