性能退化数据下的VDMOS可靠性分析

依据VDMOS可靠性实验获得的性能指标退化数据,选择导通阻抗作为表征VDMOS性能退化的关键指标,用二阶最小二乘估计的方法拟合了VDMOS关键性能指标退化数据的回归曲线.以该性能指标的相对增量(初始值的20%)为阈值,给出了VDMOS的伪寿命估计.然后基于获得的伪寿命数据,在VDMOS寿命服从Weibull分布的假设下,研究并估计了该分布的形状参数与尺度参数.最后结合W统计量对该假设进行了检验,进一步说明了Weibull分布假设的合理性.

Reliability Analysis for VDMOS with Degradation Data

Based on the performance degradation data derived from experiments for the VDMOS,this paper selects the RDS(on) as the key index to describe the degeneration of the VDMOS.The method of the second-order least squares estimation is used to fit the regression curve with the help of performance degradation data.By using the regression curve,the pseudo life of VDMOS is derived by regarding the relative increment of RDS(on) (20％ of the initial value) as the threshold value.With the assumption that the failure life distribution of VDMOS follows Weibull distribution,we get the estimate of shape parameter and scale parameter of the Weibull distribution based on the pseudo life data.The rationality of such assumption is also tested at the end of the paper by W statistic.