基于Kolmogorov-Smirnov检验的LED可靠性评估

Reliability Assessment of LED Based on Kolmogorov-Smirnov Check

提出一种对光参量呈非单调下降规律的LED灯珠可靠性进行评价的方法.采用加速寿命实验获得光通量退化数据,利用指数叠加形式的退化模型对光通维持率退化数据进行拟合,与指数模型拟合效果相比,该模型具有更好的效果.用MATLAB软件计算样品的伪失效寿命,通过KolmogorovSmirnov检验法得到两个公司样本伪失效寿命分布分别服从对数正态分布和威布尔分布,以相应分布参量评估产品可靠性得到两个公司样本的伪失效寿命分别为5 328.37h和4 758.35h.该方法对参量呈非单调下降规律的LED器件可靠性的评估具有参考价值.

A reliability evaluation method was proposed for Light Emitting Diodes（LED）which the optical performance is declining nonmonotonicly.The accelerated degradation test was conducted in order to obtain luminous flux degradation data.A bi-exponential degradation model was used to fit the lumen maintenance degradation data.Comparing the model with exponential model in fitting effect,indicates that the bi-exponential model provides a good fit to the date.The pseudo failure lifetime was tested and analyzed by MATLAB program.The distribution type of pseudo failure life was determined by using Kolmogorov-Smirnov（K-S）test.The results showed that,the pseudo failure lifetime distribution of samples from two companys obeys Lognormal distribution and Weibull distribution,respectively.And the reliability evaluation of LED is made by the corresponding distribution parameters.It was obtained that the pseudo failure lifetime of samples from two companies is 5 328.37 h and 4 758.35 h,respectively.This method shows a certain reference value to reliability evaluation on nonmonotonic degradation law of LED.