高热流密度LED离子风散热系统性能研究

发布时间：2018-12-23 08:52

【摘要】：随着相关技术的飞速发展,LED的功率增长速度越来越快,产生的热流密度越来越高,LED对创新、先进的散热技术的需求越来越紧迫,对散热技术的要求也越来越高,散热问题一直以来都是制约LED发展的关键因素之一。由此可见,LED急需新一代散热技术,该技术应该具备以下优点:高散热效率,小重量,小体积,低成本,低噪音,低功耗,可集成度高,没有运动部件等。离子风散热技术具备这些优点,很可能成为满足LED散热的新一代散热技术。本文基于电晕放电理论,设计了一种离子风发生装置,装置由针状发射电极和网状收集电极组成,其具备前面提到的各个优点,能与LED芯片高度集成,实现一体化封装;同时,设计了实验测试平台,对影响离子风发生装置性能的关键参数进行了研究,重点研究了发射电极形状、收集电极形状、电极间距和工作电压等因素对离子风发生装置的影响,针对散热表面尺寸为40mm×40mm的高热流密度LED芯片设计了离子风发生装置阵列,进而设计出满足LED芯片散热需求的离子风散热系统,同时,设计对比实验,对比分析离子风散热系统与传统强制风冷散热系统的散热效果,具体研究内容与结论如下:1.采用紫铜作为发射电极和收集电极的材料,利用激光加工设备对0.1mm厚度的紫铜板进行激光加工,通过后期组装制成离子风发生装置,使用单一变量法对网状收集电极网格尺寸、针状发射电极直径和电极间距等影响因素逐一展开实验研究,结果表明:收集电极网格尺寸为1.0mm×1.0mm、发射电极直径为0.122mm、电极间距为5mm是优选的结构参数,实现的最高风速达到2.45m/s。2.设计了一个适用于离子风发生装置阵列性能测试的实验平台,通过控制单一变量,对离子风发生装置阵列纵向间距、横向间距,以及收集电极与散热表面夹角等关键参数进行实验研究,实验结果显示:优选的纵向间距为6mm,优选的横向间距为2.64mm,收集电极与散热表面夹角优选值为30°,实现的最低温度为50.29°C。3.分别研究了不同热流密度、不同工作电压等因素对LED离子风散热系统性能的影响,并设计对比实验,对比分析离子风散热系统与传统强制风冷散热系统的散热效果,实验结果表明:在0.3752cm W热流密度下,系统的散热效果最佳,实现的对流换热系数最高可达到75.56W/(3　);当工作电压为4.2k V时,系统的散热效果良好,实现的对流换热系数最高可达到66.71W/(3　);当功耗在0-0.026W时,离子风散热系统占有绝对优势,实现的对流换热系数最高可达到51.30W/(3　)。本文为高热流密度LED离子风散热系统的设计、结构优化提供了新思路,对离子风散热系统的传热特性和应用研究丰富了LED芯片热管理的应用体系,为以LED芯片为代表的高热流密度芯片的热设计提供了新方案。
[Abstract]:With the rapid development of related technology, the power of LED is increasing faster and faster, and the heat flux is becoming higher and higher. The demand of LED for innovation and advanced heat dissipation technology is more and more urgent, and the requirement for heat dissipation technology is also more and more high. Heat dissipation has always been one of the key factors restricting the development of LED. Therefore, LED is in urgent need of a new generation of heat dissipation technology, which should have the following advantages: high heat dissipation efficiency, small weight, small volume, low cost, low noise, low power consumption, high integration, no moving parts, etc. Ion wind heat dissipation technology has these advantages, and it is likely to be a new generation of heat dissipation technology to meet the LED heat dissipation. Based on the theory of corona discharge, an ion wind generator is designed in this paper. The device is composed of needle-like emission electrode and net-shaped collection electrode. It has the advantages mentioned above, and can be highly integrated with LED chip to realize integrated encapsulation. At the same time, the experimental test platform is designed to study the key parameters that affect the performance of the ion wind generator, especially the shape of the emission electrode and the shape of the collecting electrode. The effect of electrode spacing and working voltage on the ion wind generator was studied. An array of ion wind generating devices was designed for a high heat flux LED chip with a heat dissipation surface size of 40mm 脳 40mm. Then we design the ion wind heat dissipation system which can meet the demand of LED chip. At the same time, we design the contrast experiment, compare and analyze the heat dissipation effect of ion wind cooling system and traditional forced air cooling heat dissipation system. The specific research contents and conclusions are as follows: 1. Using copper as the material of emission electrode and collecting electrode, the copper plate with 0.1mm thickness was processed by laser processing equipment, and the ion wind generating device was made through the later assembly. A single variable method was used to study the influence factors such as mesh size, needle emission electrode diameter and electrode spacing. The results showed that the grid size of the collecting electrode was 1.0mm 脳 1.0 mm, the diameter of the emission electrode was 0.122 mm, and so on. The electrode spacing of 5mm is the optimal structural parameter, and the maximum wind speed is 2.45 m / s. 2. An experimental platform for measuring the performance of ion wind generator array is designed. By controlling a single variable, the longitudinal and transverse spacing of ion wind generator array is calculated. The experimental results show that the optimized longitudinal distance is 6 mm, the optimal transverse distance is 2.64 mm, and the optimum angle between the collecting electrode and the heat dissipation surface is 30 掳. The realized minimum temperature is 50.29 掳C. 3. The effects of different heat flux and working voltage on the performance of LED ion cooling system were studied, and a comparative experiment was designed to analyze the effect of ion air cooling system and traditional forced air cooling system. The experimental results show that under the heat flux of 0.3752cm W, the heat dissipation effect of the system is the best, and the highest convection heat transfer coefficient can reach to 75.56W/ (3?). When the working voltage is 4.2 kV, the heat dissipation effect of the system is good, and the highest convection heat transfer coefficient can reach 66.71W/ (3?). When the power consumption is 0-0.026W, the ion wind heat dissipation system has the absolute advantage and the highest convection heat transfer coefficient can reach 51.30W/ (3?). This paper provides a new idea for the design and structure optimization of LED ion cooling system with high heat flux. The research on heat transfer characteristics and application of ion wind cooling system enriches the application system of LED chip thermal management. It provides a new scheme for heat design of high heat flux chip represented by LED chip.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN312.8

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