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Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

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Original Message:

Posted by: Ben Walters (bwalters@etec.com )
Organization:Reliability Engineering Manager
Date posted: Tue Jan 12 20:15:37 US/Eastern 1999
Subject: Aluminum Electrolytic Capacitors
Message:
Can anyone provide info concerning the use of aluminum electrolytic capacitors in a controlled, benign environment? From past employers in the defense/aerospace industry, we always avoided these capacitors due to possible outgassing, creating a fire/explosion situation if a spark occurred. This was over 10 years ago, though. Has the technology of these capacitors changed and are they safer to use? Appreciate any help you can provide. Please e-mail to me as well as respond to this forum. Thanks again.


Reply:

Subject: Al Electrolytic Caps
Reply Posted by: Bruce Dudley (bdudley@alionscience.com )
Organization: Reliability Analysis Center
Date Posted: Wed Jan 13 16:10:26 US/Eastern 1999
Message:
Current manufacturing techniques for al electrolytic capacitors have minimized the problem of outgassing at low pressue-high altitude applications. These devices are now approved for use in airborne conditions. A manufacturing problem that should not be over-looked when using al electrolytics is the use of circuit board cleaning agents. These agents, such as trichloroethylene and freon, can and do seep around the end cap seal resulting in corrosion of the internal structure of the capacitor and failure. This information was found in our report "Reliable Application of Capacitors", 1996.


Reply:

Subject: Al Electrolytic Capacitors
Reply Posted by: Koh Siew Huay (ksiewhua@dso.org.sg )DSO National Laboratories
Date Posted: Tue Feb 22 21:14:58 US/Eastern 2000
Message:
I refer to Bruce Dudley's response, is the approval(for use in airborne conditions) applicable to all manufacturers or only certain manufacturers? Would I be able to find any technical reports that show all Al Electrolytic Capacitors are safe to use in airborne conditions or list of approved manufacturers? If Al Electrolytic Capacitor is fully potted, will it be safer or more hazardous? Will the potting cause the safety vent unable to release internal pressures ? Thank you.


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