大功率LED热阻自动测量方法研究

Method of Automatic Measurement of Thermal Resistance of High Power LED

摘要:

在没有散热措施的情况下,大功率LED芯片的温度迅速升高,当结温超过最大允许温度时,大功率LED会因过热而损坏;大功率LED灯具设计中,最主要的设计工作就是散热设计;利用LED半导体器件的结电压与结温具有良好的线性关系的特性,通过测量大功率LED工作时的正向压降、工作电流、恒温箱温度和热衬温度,采用电学参数法,实现了大功率LED热阻的自动测量;设计并制作了大功率LED热阻自动测量仪,快速、准确地测量了LED晶片到热衬的热阻;6种不同规格LED晶片到热衬的热阻测量值与计算值之间的误差小于10%;热阻测量值普遍高于理论计算值,说明LED制造工艺水平还有很大的提升空间。

Abstract:

In the absence of cooling measures, the wafer thermal of high power LED rises rapidly. When the junction thermal exceeds the maximum allowable thermal, the high power LED will be damaged due to overheating. In the design of high power LED lamps, the main work is to the thermal design. Using a good linear relationship characteristic of the semiconductor devices between the LED junction voltage and junction thermal, this paper measured the high-power LED working voltage, working current, thermal of the incubator and heat sink. Adopting the method of electrical parameters, the paper measure the thermal resistor of high power LED. The high-power LED thermal resistance measuring instrument is designed and made. The thermal resistance from the LED wafer to the heat sink is measured fast and accurately, and the error is less than 10%. The measured value of the thermal resistor is generally higher than the theoretical calculated value. It shows that the LED manufacturing technology level can be improved.