Physical acceleration means that operating a unit at some higher stress level(s) (i.e, higher temperature, voltage, humidity or duty cycle, etc…) should produce similar failures as would occur at typical-use stresses, except that they are expected to occur much sooner. Failures may be due to mechanical fatigue, corrosion, chemical reaction, diffusion, migration, etc. These are the same cause of failures under normal stress condition; the only difference is the time scale (the time to failure). When there is true acceleration, changing stress is equivalent to transforming the time scale used to record when failures occur. The transformations commonly used are linear, which means that time-to-fail at high stress just has to be multiplied by a constant (the Acceleration Factor or AF) to …
Creating a Qualification Framework can pay-off big as your product matures
We can't under-estimate the power of a well laid-out qualification process. We've all heard about DVT, the Design Verification Process step that puts one's product through several testing requirements; but a comprehensive qualification plan requires more than DVT. My professional experience has shown that a 3 steps qualification process: EVT, DVT and PMT allows a much more thorough qualification. These acronyms can be stated differently in different organizations, but they have about the same meaning: EVT is for the early stages of product development, when the product is still somewhat imature; for example, for an electronic assembly, one can choose to conduct EVT on just the PCBAs before they are mated to the main system. DVT is for a more mature stage of product development, when …
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