剔除大功率LED早期和次早期失效的非老化方法探究

Elimination of high power LED early and early failure of non aging method research

LED老化测试在产品质量控制中是一个非常重要的环节,本文根据产生LED老化的原因,提出了剔除大功率LED早期和次早期失效的非老化方法,包括利用LED电压与结温的关系,剔除电压降异常器件;利用LED启动阀值和(或)关闭阀值的差异,剔除不协调品;利用LED封装材料膨胀系数和收缩比差异产生的应力,剔除封装不良器件;采用面测温方式,剔除高电流密度器件;利用波长红移效应,剔除波长红移异常器件。采用这些方法选择LED器件,制作出的的路灯,已挂网运行多年,效果良好。

LED aging test is a very important part in product quality control.In this paper,based on the cause of aging produce the methods for eliminating early failure and secondary early failure of high power LED are proposed: including use the relationship between LED voltage and junction temperature to excluding abnormal voltage drop devices;utilizing LED start threshold voltage and (or) turn off threshold voltage difference to excluding uncoordinated products; LED packaging materials use the stress causing by the coefficient of expansion and contraction differences to excluding packaging bad devices; use surface temperature measurement methods to excluding high current density devices; utilize wavelength red shift effect to eliminate wavelength red shift anomalies devices.Employing these methods to choose the LED devices,we manufactured the LED street lamp which had been working very well for years.