Optimal thermal design of LED automotive headlamp with the response surface method

Light Emitting Diode (LED) is gradually being applied in automotive lighting systems as the new generation of light source. Recently, increasing demands are adapt on automotive headlamps, including not only being functionally perfect, cost-effective and durable, but also with fashion, energy saving and environmental protection. LED light source has the advantages of long lifetime, high efficiency and energy saving, compact size etc., therefore, it has been widely used in headlamps, turn signals, brake lights, position lights, etc., and will soon become the mainstream of the automotive light source market. Although it has higher energy conversion efficiency, LED headlamp is still suffering difficulties on the thermal management. In this paper, we optimize the designs of heatsink for a commercialized LED automotive headlamp module by using the response surface method. Firstly, the temperature distribution of the test sample is simulated by the finite element (FE) method. Then, we use the response surface method to optimize the design parameters of heatsink on its thermal dissipation capacity. The results indicate that: (1) Through optimizing the structure of the heat sink with the thickness, spacing and height of fins as 3mm, 9mm and 60mm respectively, the LED junction temperature drops by 2.9%; (2) By changing the materials of heat sink and PCB substrate as 6063 aluminum alloy and AlN respectively, the LED junction temperature lowers down by 11.9%.