Failure mechanism based failure rate model

For electronic products, the typical failure rate curve takes on three-stage bathtub shape, while few failure rate equations can describe the bathtub shaped curve. Based on environment load impact failure mechanism, the present paper develops load-property interference failure rate model for electronic products. The operation load, i.e. the impact is taken as a random process, and product property suffers degradation over service time. The ever changing load-property relationship yields the variation in failure rate curve. During service life, the product is continuously subjected to stochastic load impact, and product property degrades continuously. Since failure occurs when a load higher than the relevant property appears, failure rate model can be developed based on load statistical characteristic and product property. From such a principle, the variation in failure rate is interpreted in both the load uncertainty and product property uncertainty. Moreover, the effects of product property degradation, as well as load dispersion and product property dispersion on failure rate are highlighted.