Proportional hazards model for reliability analysis of solder joints under various drop-impact and vibration conditions

This paper is devoted to the use of a proportional hazards model (PHM) for reliability analysis of solder joints through two case studies: a drop-impact test and a vibration test. The lifetime data collected under various load conditions can be integrated in establishing a PHM for reliability analysis of solder joints. PHM has the capability of evaluating the influence of load conditions (e.g. drop height, power spectrum density in random vibration) on the life span of solder joints. Using this capability, this paper focuses on the implementation of PHM for estimating the reliability characteristics (MTTF and probability density function (p.d.f.) of failure) of solder joints whose load conditions are not contained in the training dataset of the PHM. In comparison with the naive use of lifetime data by simply ignoring the effect of load conditions, the two case studies verify the effectiveness of PHM in providing consistent reasonable estimation of the reliability characteristics of solder joints. The perspectives and the procedures of the use of PHM in this paper are generic and can be directly adopted for other systems/products.