Thermal simulations and design propositions for LEDs used in automotive applications

Thermal simulations of power LED's packaging were performed. Results focus on design proposals for Rth and thermal management improvements, favoring the use of LEDs in automotive lighting. As automotive applications require ever increasing power from LEDs, thermal management is still one major issue for lighting systems designers. Ambient temperature in the front lighting system can get as high as 85°C which readily leads to the conclusion that thermal resistance from the light source junction to the heat sink fins must be as low as possible to avoid overheating. Working with LED suppliers and pushing their designs to fit automotive criteria is a continuous need for innovative tier ones suppliers to keep competitive. In this paper, we present thermal simulations performed to find design solutions for LED typical packaging. Starting with the precise knowledge of the construction and materials used in the LED's structure, and knowing the industrial constraints, we have studied the improvements that could be implemented on existing packages.