Accelerated storage degradation test and life extension assessment method for hermetically sealed electromagnetic relay

For products which are required for long-term storage, it is difficult to assess their reliability or life extension due to lack of historical usage data or test data. This paper presents a life extension assessment method based on the accelerated storage degradation test (ASDT) and the degradation model with random performance parameters. The typical failure modes and mechanisms of hermetically sealed electromagnetic relay under die storage condition are analyzed. The degradation process of contact resistance (contact failure) is described using die Arrhenius model. In the accelerated storage degradation test, the contact resistance is selected as die major performance parameter to be measured. The composite activation energy parameter in the Arrhenius model was obtained by the degradation model with random performance parameters. Then, the life extension and the reliability are assessed combining with the historical storage environment data. The assessment result shows that the electromagnetic relay used in the airborne electronic part can satisfy the operating requirement of life extension for 10-year.