When an assemblied board was on active service, what's the main reason for its failure:the package broken; the mechanics fatigue failure under thermal cycle; the corrosion caused by salt and vapor; the broken chip inside the package etc. I think all the above may be the main reason of failure ,I want to know : when the environment was good enough and bad ,which is the main reason; for the common component,what's the reason for its failure? Thank you !
Gwen: Failures occur during a products life cycle, as you say. According to Reliability Analysis Center, overall factors affecting reliability are: � Maintenance shop (17%) � Hardware reliability (16%) � Retest OK (28%) � Design (21%) � Quality (18%)
Failures occurring during the operational life of a product are random events. Component reliability, workmanship, and applied stress problems were screened-out during the initial use of the product. Wear-out problems have not begun to occur.