Chiang Mai Journal of Science

Heat dissipation plays an important role in improving luminous efficiency and reliability for light emitting diode (LED) devices. In this paper, a new thermal interface material (TIM), graphene-epoxy composite, is synthesized and used for LED heat dissipation enhancement. Experiment is conducted to measure the TIM interface resistance, and the junction temperatures of LED with and without such TIM are compared through simulation. The results show that thermal conductivity increases with growing graphene ratio and the interface resistance can be decreased by more than 65 % with the synthesized TIM. Besides, for the same graphene ratio in TIM, interface resistance drops considerably with increasing contact pressure. The case study indicates that junction temperature decreases from 72 ฐC to 67 ฐC for a 10 W power LED after using TIM, and such temperature difference becomes larger for bigger LED power. This work is important for practical heat sink design and optimization for LED equipment with TIM.