对数正态分布分析法求取LED器件光通维持寿命

Analytical Method of the Lumen Maintenance Life of LED Devices Based on Lognormal Distribution

由于发光二极管(LED)属于半导体器件,其参数退化服从对数正态分布。基于对数正态分布的数值分析法,研究了LED的光通维持寿命,通过以温度为应力的恒定压力加速寿命试验,并以LED器件的光通维持率作为失效判据,对LED器件加速寿命试验数据进行了分析处理。采用定数截尾的加速寿命试验方法,基于对数正态分布的基本假设,通过对对数正态分布的主要参数进行估计,给出了LED器件的加速模型,由此得到LED器件正常工作时的光通维持寿命,并且采用了图估法证明了该方法的有效性。

As the light emitting diode （LED） belongs to the semiconductor device, the parameter degradation submits lognormal distribution. The lumen maintenance life of LED devices was studied based on the lognormal distribution of numerical analysis method. The data of accelerated life tests of LED devices were analyzed by taking the temperature of constant stress accelerated life test and taking the lumen maintenance of LED devices as the failure criterion. By carrying out the life test ending with a provided number, the average life of LED devices under the normal working condition can be calculated by estimating the main parameters of lognormal distribution via basic hypothesis and setting up the accelerating model of LED devices. And the program estimate method was used to verify the effectiveness of this method.