Reliability Prediction for Aerospace Electronics
Final rept. 15 Jul 014-14 Apr 2015
ARIEL UNIV (ISRAEL)
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This project presents a method for predicting the failure rate, and thus the reliability of an electronic system by summing the failure rate of each known failure mechanism. The approach combines the physics of failure for each mechanism with their effects as observed by HighLow temperature, HighLow voltage, and current stresses. The method assumes that lifetime of each of its failure mechanisms follows constant rate distribution and each mechanism is independently accelerated by the stress factors that can be entered into a reliability model. The overall failure rate therefore follows an exponential distribution and is described in the standard FIT Failure unIT or Failure In Time. The method combines mathematical models for known failure mechanism and solves them simultaneously at a multiplicity of accelerated life tests to find a consistent set of weighting factors for each mechanism. The result of solving the system of equations is a more accurate and a unique combination for each system model by proportional summation of each of the contributing failure mechanisms. Consequently, this matrix approach gives a very cost-effective way to predict reliability based on the Physics of Failure using only three tests as compared to the normal single-mechanism approach. Finally, this methodology can be extended to include radiation effects, frequency, and even packaging and solder joint effects to give a complete system reliability evaluation framework. Such efforts are being pursued in a follow-on project.
- Electrical and Electronic Equipment