脉冲电流测量LED结温的方法及不确定度分析

The Method of Pulse Current Measuring LED Junction Temperate and the Uncertainty Analysis

脉冲电流法是基于正向电压法原理的一种新的测量LED结温的方法。本文阐述了脉冲电流法的原理,详细介绍了根据脉冲电流法所建立的测试系统,并对温度-电压系数和LED结温的不确定度进行了分析。结果表明,在LED结温和温度-电压系数的各种不确定度分量中,LED正向电压的测量重复性所引起的测量不确定度最大。这说明,提高测量LED结温的准确度,不仅需要提高测量仪器的准确度,而且还需要对LED的制造材料加以研究,尽量减少LED材料本身对测量的影响。

The pulse current method is a new kind of method in measuring LED junction temperature which is hased on the forward-voltage principle. This paper gives an introduction on the principle of the pulse current method. The testing system which is built according to the pulse current method and also the uncertainty evaluation of the temperature -voltage coefficient and the LED junction temperature are illustrated. The results show that the most important influence quantity in the component of the LED junction temperature and temperature-voltage coefficient uncertainty arise from measuring repeatability of the LED forward voltage. This demonstrates that, improving the measurement accuracy of the LED junction temperature depends not just on the accuracy of the measuring instruments ,but also on the manufacturing materials of the LED worth further studying in order to minimize the measurement influence from LED itself.