Electronic-module environmental-stress-screening data-evaluation technique

This report has provided a reliability engineering analysis technique to support optimization decisions for a production environmental stress screening (ESS) program and demonstrated its use. The important groundrules used in this analysis are: (1) a disciplined approach to the ESS process is required for the results of this analysis to be effective; and (2) the failures per thermal cycle should be distributed equally throughout the cycle in order to represent a realistic scenario. The benefits associated with the analysis technique include: (1) the parameter, “failures per thermal cycle”, has a simple accounting method and is easy to accurately collect; and (2) the tools are PC based and facilitate timely reaction to management requests. The observations made during the generation of this report are: (1) all ESS failures must be analyzed for root cause and effective corrective action; (2) the input data to the analysis technique must be completely understood so that the results of the optimization decision process are prudent; and (3) feedback from field performance is a vital element in the optimization process