【作者】 孙毅；

【导师】 王春青；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2012， 硕士

【摘要】 针对大功率LED照明一体化集成封装不便于维修和升级的现状，本文以路灯或室内照明为背景，从模块化的思想出发，设计了可随意拆装和组合的模块。为满足结温约60℃和最大外包围尺寸不超过100×100×60mm3的要求，本文对整个热管理方案，从芯片键合到空气对流换热，逐步进行了设计和优化，从根本上降低了热阻，并研制了样品进行测量和评价。采用双面覆铜板（DBC）作为芯片基板，运用ANSYS有限元软件通过数值模拟的方法研究了各层厚度和芯片间距对基板热阻的影响并得出最优尺寸。通过正交试验和数值模拟，设计了基于热管的依靠空气自然对流换热的散热器，并研究了各尺寸因素影响散热性能的显著性，得到最优尺寸并实验验证。比较了铜和铝两种材料，铜的热导率虽然高于铝，但均属于高热导率金属，散热效果十分接近，从轻量化和成本方面考虑，铝是优选的散热器材料。采用正向电压法和红外热成像法对LED芯片结温和散热结构进行了测量，并使用有限元模拟对散热片与热管的接触热阻进行了估算，模拟结果与实际测量吻合，证实了DBC与热管热沉表面的接触热阻、散热片与热管的接触热阻、散热片与空气的对流换热热阻是影响散热器效果的主要因素。实测结果表明，使用SnBi钎料改善DBC与热沉的接触能得到6.12%的性能提升，进一步采用SnAgCu钎料焊接散热片与热管，能使散热性能提升15%。空气对流换热热阻约占有总热阻的80%，进一步优化散热片尺寸能获得22%的性能提升。更多还原

【Abstract】 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.更多还原