Design for qualification

A design methodology based on the concept of designing electronic equipment to ensure rigorous qualification is presented. The design-for-qualification philosophy recognizes that life-critical electronic equipment must be designed in a manner that allows rigorous analysis in order to meet reliability goals. Several projects have already demonstrated that formal physics-of-failure evaluation is useful and cost-effective for uncovering faults early in the design process. For example, in a study of a printed wiring board assembly, acceptable aspect ratios for plated-through-holes subject to infrared reflow soldering were determined using formal physics-of-failure methods. The experience gained was used to qualify SMT (surface mount technology) printed circuit assemblies for a NASA satellite program.<>