基于离子风技术的功率型LED散热研究

发布时间：2018-03-29 20:24

  本文选题：离子风　切入点：电晕放电　出处：《江苏大学》2017年硕士论文

【摘要】：近年来,随着全球制造业对产品“低碳化、高效化、环保化”的日益重视,“绿色光源”LED在照明领域得以广泛应用。尤其是功率型LED的出现,满足了诸多照明应用场合对光源的苛刻要求。但是,受到发光原理和自身结构的限制,LED芯片内部极易产生热量堆积,尤其是高驱动电流下的功率型LED,工作性能及使用寿命更是受到结温的严重影响,致使当前不少场合对功率型LED的应用都停留在实验室研究阶段,而难以实现产业化。随着制造工艺和封装技术的不断推进,LED芯片内部热阻已得到明显降低。因此,选择一种高效的外部散热方案成为改善功率型LED热管理问题的关键。本研究针对传统散热方案应用过程中的缺点,提出了一种基于电晕放电原理的离子风散热方案,设计加工出了一款结构可调的离子风散热装置。通过试验探寻了离子风发展过程中的伏安特性变化规律,并从中得出影响离子风特性的主要因素包括电源极性、发射极与接收极的结构、放电间距等。这些因素对离子风发生器的起晕电压、工作电压的可调范围、离子风风速以及功耗等诸多性能有直接影响。因此,本研究搭建了一套测试系统,进行了离子风发生器的散热应用试验。试验以功率型LED芯片组达到稳定工作状态时的引脚温度、芯片结温、系统热阻等为控制目标,在进行散热系统搭建时,根据发热器件的结构及发热特点进行放电电极分布的优化设计,探讨了不同的离子风散热方式对功率型LED的散热效果。研究结果表明,离子风散热方案可有效缓解功率型LED使用过程中结温过高的问题,离子风的产生大大提高了散热装置的极间换热系数,当散热系统与LED芯片在常温下同时处于工作状态时,芯片引脚温度可保持在50℃以下。与自然对流状态下相比,在离子风的作用下,系统热阻显著减小。选择针状电极作为离子风发生器的发射极,并对发射极输入负极性高压,可降低放电过程的起晕电压,增大工作电压的可调范围,同时还能够提高整个散热装置的工作稳定性。研究针对LED芯片组所设计的“一字型”针电极阵列,是几种针电极阵列中综合散热效果较好的设计方案。
[Abstract]:In recent years, with the increasing attention of the global manufacturing industry to "low carbonization, high efficiency and environmental protection", the "green light source" LED has been widely used in the field of lighting, especially the emergence of power type LED. It meets the harsh requirements of light source in many lighting applications. However, due to the principle of luminescence and the limitation of its own structure, it is easy to generate heat accumulation inside the LED chip. Especially, the performance and service life of power type LEDs under high driving current are seriously affected by junction temperature, which results in the application of power type LED in laboratory research stage. However, it is difficult to realize industrialization. With the continuous development of manufacturing technology and packaging technology, the internal thermal resistance of LED chips has been significantly reduced. Choosing an efficient external heat dissipation scheme is the key to improve the thermal management of power type LED. In this paper, a scheme of ion wind heat dissipation based on corona discharge principle is proposed to solve the shortcomings of the traditional heat dissipation scheme. A structure adjustable ion wind heat dissipation device is designed and manufactured. The variation law of volt-ampere characteristics during the development of ion wind is explored through experiments, and the main factors influencing the ion wind characteristics include the polarity of power supply, from which we can find out that the main factors affecting the ion wind characteristics include the polarity of the power supply. The structure of emitter and receiver, the distance between discharge and so on. These factors have direct influence on the corona voltage of ion wind generator, the adjustable range of working voltage, the wind speed of ion wind, power consumption and so on. In this study, a testing system was set up, and the heat dissipation test of the ion wind generator was carried out. The control targets were the pin temperature, chip junction temperature and system thermal resistance when the power LED chipset reached the stable working state. When the heat dissipation system is built, the optimum design of discharge electrode distribution is carried out according to the structure and characteristics of the heating device, and the heat dissipation effect of different ion air cooling modes on the power type LED is discussed. The scheme of ion wind heat dissipation can effectively alleviate the problem of excessive junction temperature in the use of power type LED. The generation of ion wind greatly increases the inter-polar heat transfer coefficient of the heat dissipation device. When the cooling system and the LED chip are simultaneously working at room temperature, The chip pin temperature can be kept below 50 鈩，

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