Emperical limit testing – the benefits of discovery and comparisons instead of assumptions and predictions

Reliability engineering of electronics systems has been historically focused on quantifying life entitlement regardless of the fact that most field failures are not due to intrinsic physical mechanisms in components or devices that can be modeled. Customers are likely not interested in theoretical lifetimes, nor are they likely to believe predicted life claims. They mostly care that the product doesn’t fail during use. David Packard stated in 1972 that "Reliability cannot be achieved by adhering to detailed specifications. Reliability cannot be achieved by formula or by analysis. Some of these may help to some extent, but there is only one road to reliability. Build it, test it, and fix the things that go wrong. Repeat the process until the desired reliability is achieved. It is a feedback process and there is no other way." What David Packard did not know in 1972 is that electronics will become much stronger and used in much harsher environmental conditions in the 21st Century. Finding weaknesses takes longer now to discover defects and weaknesses under worst case stress simulation tests than testing to stress operational limits. This webinar will present the advantages of using empirical limit tests, including HALT (Highly Accelerated Life Test) methods but may not require a “HALT” environmental test chamber. Empirical limit testing may include many other stimuli besides temperature and vibration. Empirical testing can be done in traditional stress testing equipment, such as ED shakers and environmental shakers. Testing to discover empirical limits establishes a stress-strength benchmark to compare successive products. Empirical stress limits can also be used to use the highest safe stresses for fast stress screening in manufacturing to find and remove latent infant mortality defects before shipping to customers.