真空荧光显示屏恒定及步进应力加速寿命试验的研究

Study on Constant-Step Stress Accelerated Life Test of Vacuum Fluorescent Display

为了解决在较短的时间内预测真空荧光显示屏(VFD)寿命的问题,降低寿命预测成本,通过加大灯丝温度进行了恒定和步进应力相组合的加速寿命试验,研究制定了其加速寿命试验的设计方案。应用威布尔分布函数描述其寿命分布,利用最小二乘法完成了试验数据的统计和分析,并开发了寿命预测软件。研究结果表明,试验设计方案是正确可行的,VFD的寿命服从威布尔分布,其加速模型符合阿伦尼斯方程,加速参数的精确计算确保以后在很短的时间内便可估算出VFD在正常应力下的寿命。

In order to solve the problem that the life of Vacuum Fluorescent Display （VFD） is forecasted in shorter time and to reduce the cost of the life prediction, the constant-step stress accelerated life test was performed with the filament temperature increased, and the design scheme of the accelerated life test for the vacuum fluorescent display was established. The statistic and the analysis on test data were achieved by applying the lognormal distribution to describing the life, and the Least square method （LSM） to estimating Weibull parameters, moreover, the predicted-life software was self-weaved. The results show that test design scheme is correct and feasible, the VFD life submits to Weibull distribution, the life-stress relationship meets Arrhenius equation, and the refined calculation of accelerated parameters makes it sure that the VFD life at the normal working stress can be estimated in a short time.