Lifetime and duty cycles of automotive electronics are increasing, inducing new challenges to reliability predictions and testing. For qualification purposes, the automotive industry generates various time-dependent mission profiles with various stressors and varying stress levels according to different use cases. We present a theoretical model, describing the common approach, to reduce the stressors from time-dependent mission profiles to the two single parameters "effective stress level" and "effective stress time" for equivalent reliability testing. In a first step, the cumulative exposure (CE) model is shown to describe the future reliability behaviour after steplike stress level changes. Taking into account the individual characteristic lifetimes T-63 of the corresponding Weibull distributions, in a second step, an effective T-63 lifetime can be derived. For this calculation, periodic stress cycles are defined and transformed into an equivalent effective stress level. This procedure confirms the industry-wide used approach of dealing with effective stress levels for reliability testing. For the experimental validation metal-oxide-semiconductor (MOS) capacitors are fabricated and stressed by voltage and temperature. The received reliability data fit the theoretical predictions within the statistical variations.    «

Lifetime and duty cycles of automotive electronics are increasing, inducing new challenges to reliability predictions and testing. For qualification purposes, the automotive industry generates various time-dependent mission profiles with various stressors and varying stress levels according to different use cases. We present a theoretical model, describing the common approach, to reduce the stressors from time-dependent mission profiles to the two single parameters "effective stress level" an...    »