基于三参数Weibull分布模型的LED寿命预测研究

Research on the Life Prediction of LED Based on Three-parameter Weibull Statistical Distribution Model

首先,通过恒定、步进和步降加速应力试验方法获得了小功率LED的寿命信息;然后,采用三参数Weibull统计分布模型描述了LED的寿命分布,并对所拟合的分布模型进行参数显著性检验;最后,结合Nelson原理和逆幂律定理,分别预测了LED试验样品的平均寿命和中位寿命。结果表明,利用步进加速应力试验所获得的LED寿命信息来进行寿命预测更加合适,可靠性水平相对较高;并且其预测LED的平均寿命值和中位寿命值也高于利用恒定和步降加速应力试验所得到的预测寿命值。

Firstly, the life information of small power LED is obtained through the constantstress, step-stress and step-down-stress accelerated life test. Next, the life distribution of LED is described by three-parameter Weibull statistical distribution model, and the significance of the parameters of the fitted distribution model is tested. At last, combining with Nelson principle and inverse power law, the average life and median life of LED are predicted. The results show that the life information of LED obtained through step-stress accelerated life test is more suitable to predict the life of LED, and its reliability is relatively high. Besides, the average life and median life of the LED predicted based on the data obtained through step-stress accelerated life test are higher than the results obtained through constant-stress and step-down- stress accelerated life test.