Improvement in the heat dissipation of matrix LED headlamps for vehicles according to the thickness and thermal conductivity of thermal interface materials

Abstract

This study examined the effects of thermal interface materials (TIMs) in light-emitting diode (LED) headlamps for vehicles based on thermally conductive plastics. Heat transfer is a very important issue in LED applications because the stability and performance of LEDs decrease considerably with increasing junction temperature. When two solid surfaces are placed in contact, a TIM is used to reduce the thermal interface resistance. This study examined the effects of the thickness (0.3, 0.5, and 1.0 mm) and thermal conductivity (1.8, 3.0, 5.0, and 11.0 W m-1 K-1) of a TIM on the soldering temperature (T S). T S increased with increasing TIM thickness. In addition, T S decreased with increasing thermal conductivity of the TIM. The junction temperature (T J) was lower than the others when a TIM with a high thermal conductivity of 11 W m-1 K-1 was used. Overall, the T J and T S can be reduced using a suitable high thermal conductivity TIM with an appropriate thickness.