Prediction of system level failure probabilities of printed circuit boards under vibration load using simulation-based failure mode and effects analysis

The effects of vibration loads on the reliability of printed circuit boards is gaining importance due to the increasing use in vibration-intensive areas such as the drive train of electric cars. When assessing the reliability of electronic systems, it is important to consider not only the general probability of failures, but also their effects at the system level. Different failure modes present varying degrees of safety risk, which is taken into account in the design process through target values for failure probabilities. However, the occurrence probabilities of specific failure modes are currently assessed mainly qualitatively, or based on literature values and expert estimations. This work presents a simulation-based failure modes and effects analysis (FMEA) to estimate the probability of failure modes depending on external vibration loads. The simulation-based FMEA combines a numerical simulation, a lifetime model and a probabilistic FMEA. The key to reliable estimations of failure probabilities is the quantification of uncertainties that cause variations of the structural dynamic properties and thereby variations of local stresses on the electronic components. Therefore, Bayesian model updating is conducted to find probability distributions representing the scattering of selected parameters. The method is applied to a test printed circuit board and validated with experimental failure data.