The Design Of High Power LED Lighting Module

Considering the status that integration package for high power LED lighting is not easy to repair and upgrade, LED modular is proposed for street lighting or indoor lighting, which can be used separately or in matrix to meet the different need. To keep the temperature of junction of LED chip around60℃and the largest outside dimensions should be below100×100×60mm, the thermal management solution is researched and optimized, from the chip bonding to air convection. Experiments are carried out to prove the effect of the structure improvement.The Direct Bonded Copper(DBC) is used as the carrier of chip, and the dimension of geometry and the spacing between the chips is calculated and optimized by ANSYS finite element numerical simulation software.A type of radiator based on heat-pipe depending on air natural convection is designed. The impact of the size factors on the thermal performance is researched by orthogonal experiments and numerical simulation. And the optimum results have been arrived. Though the thermal conductivity of copper is higher than aluminum, the performance of radiator made of copper or aluminum is almost the same. So, aluminum is more suitable, which can make the radiator cheaper and lighter.The average temperature of junction and the temperature distribution of the whole cooler are measured by forward-voltage-method and infrared photography. Comparing the result of numerical simulation and measuring, it is found that contact resistance between DBC and heat-pipe, the contact resistance between fin and heat-pipe and the air convection coefficient are the three main factors that affect the heat dissipating efficiency. According to the results of experiments, using SnBi to weld the DBC and heat-pipe can get about6%performance increase. Welding fin with heat-pipe using SnAgCu may enhance the thermal dissipating efficiency by15%. The thermal resistance of air convection accounts for about80%of the total thermal resistance, and welded radiator with optimized fin can get a22%performance enhanced.