分析了LED结温精密测量中测量电流、加热电流、加热时间等三项测量因素的变化对所测结温的影响。实验采用小电流K系数法测试结温。实验结果表明:1W LED被测样品,当测量电流在0～30 mA时结温逐渐升高,当测量电流超过30 mA时结温趋于稳定;LED样品的结温数据与加热电流呈近似线性变化,表明能够通过加热电流对LED结温及相关光学性能实现线性调控。同时研究表明,结温精密测量还受到加热时间的影响,测得LED器件稳定的结温需要一定的加热时间。

The impact of the measuring junction temperature with the change of three measurement factors, i.e. measuring current, heating current, heating time, was analyzed in the LED junction temperature precision measurement. The small current K-factor method is commonly used for the measurement of junction temperature. Experimental results showed that the junction temperature of 1W LED gradually increased when the measuring current ranged from 0 mA to 30 mA, and when it exceeded 30 mA, the junction temperature would be stabilized;when the heating current changed from 100 mA to 400 mA, there existed an approximately linear relationship between junction temperature data and heating current. The result proves that, heating current had a linear modulation function for junction temperature. We also analyzed the relation between heating time and junction temperature simultaneously, with the conclusion that a certain heating time is required to obtain stability data in the measurement of LED junction temperature.