大功率LED照明灯散热路径温度场及发光效率研究

The Study on Radiation Way of Temperature Field and the Luminescent Efficiency of High-power LED Light

针对大功率LED照明灯(以下简称LED灯)内、外热传导路径的温度分布进行了热模拟分析,开发出4种大功率LED灯。通过对4种LED灯PN结导出端温度和散热片平均温度、散热结构的散热表面积及光通量的测量,并经由热阻及温度场模拟研究,得出了散热表面积和PN结温度、热阻以及发光效率间的关系。研究结果表明,大功率LED灯的热阻很大程度上取决于外部装置,设计合理的外部散热结构增大散热表面积,可以有效地降低PN结温度和LED灯的热阻,从而提高大功率LED灯的发光效率及使用寿命。

High-power LED lights＇ inside and outside heat conduction paths was simulated by temperature distribution analysis. Thus, we developed four high-power LED lights. The paper studied the temperature of PN junction, average tem- perature of heat sink, surface area of thermal structure, heat flux measurements and the simulation of temperature field of the four lights, and then we obtained the relationship among cooling area, junction temperature and the luminescent efficien- cy. The results showed that, the thermal resistance of high-power LED depends largely on external heat sink and the appro- priate design of external heat structure. Increasing the cooling surface can effectively reduce the temperature of PN junction and structure thermal resistance, to enhance the Luminescent efficiency and life of high-power LED lights.