基于PoF模型的电子产品可靠性参数计算方法

Method for reliability parameter calculation of electronic products based on physics of failure models

现有的基于失效物理(physics of failure,PoF)模型的可靠性预计只能计算电子产品在寿命周期内经历单一典型任务剖面的失效时间。本文提出了一种基于失效物理模型,并利用蒙特卡罗仿真定量分析电子产品在寿命周期内实际经历多任务剖面的可靠性水平的新方法。将该方法应用于某机载电子设备的平均失效前时间(mean time to failure,MTTF)的计算,建立失效率和可靠度的时间函数,与目前国内工程实践中常用的失效率经验模型法以及设备可靠性强化试验的结果进行了对比分析。结果表明,该方法不仅可以计算可靠性参数,而且通过分析与计算过程可发现设计薄弱环节与可靠性参数的定量关系,有效指导设计改进。

The existing reliability prediction methods based on physics of failure （PoF） models merely calculate electronic products＇ time to failure responding to a single typical mission profile. A novel reliability parameter calculation method based on PoF models and Monte Carlo simulation is presented, which can quantitatively analyze the reliability of electronic products actually undergoing multiple mission profiles in the whole life cycle. The method is applied to some airborne electronic equipment to calculate the mean time to failure （MTTF） and build time functions of failure rate and reliability. The results are contrastively analyzed with those concluded by the empirical model based method and reliability enhancement testing. It shows that the proposed method can not only calculate reliability parameters but also find out design weaknesses and their quantitative relationships with reliability parameters, which is an effective guidance to design improvements.