SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: Olga G
Date posted: Wed Nov 17 17:05:29 US/Eastern 2004
Subject: residual component life after environmental testing
I would like to know if it is possible for Electronic components, after Environmental Testing, to be used as "usual" or are there any restrictions as to their residual life?
Is there any change in the failure rate as a consequense of these tests?
Subject: Environmental Testing
Reply Posted by: BWD
Date Posted: Mon Dec 6 10:58:42 US/Eastern 2004
The application of any testing has some effect on the life of the electronic components as the damage due to fatigue is cumulative. Tests such as shock and high vibration will result in extreme loss of useful life and probably should not be used in critical applications. In MIL-HDBK-344, Environmental Stress Screening of Electronic Equipment, you will find equations to estimate the useful life remaining after vibration and temperature cycling tests. The equations are estimates and may or may not be applicable to your circumstance. The failure rate (random failure) should not change due to this testing as long as the test limits are less than the maximum values specified by the manufacturer. Only the life parameters are affected by extensive in specification testing.