Dale, Man oh man I can only say I wish I was still consulting as this is not a very good idea. Thermal shock with soldering irons was always a such a good source of revenue for me in the old days. John Maxwell >Quite a lot has been done in regard to this in the design of electronic >assemblies. There are some pretty good white papers out on part placement >changes during board design that minimize this risk, especially during >depanelization. I used to have one saved aside after an incident with a >customer of ours. I'll see if I can find it and post same. > >The only solid way we were ever successful in finding these was with a quick >touch with a hot soldering iron. The cracked terminus usually pops off the >pad if it has cracked away from the body of the part. Yes, it does expose >the cap to another shot of high temp, but it does ensure that you detect all >cracked caps and get them replaced. Since caps with cracked terminus >typically don't fail consistently during ICT or functional testing (as they >can be in parallel or be making partial contact to pogo pins which still see >a device), the soldering iron method was our only recourse. But, this is >only practical if you have a consistent problematic area of the board. In a >case where the caps may be located in many areas, trying the soldering iron >technique on an entire board is probably not very timely or cost effective. > >Good luck with this. It's a tough one... >Dale Ritzen >Quality Manager >Austin Manufacturing Services > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]]On Behalf Of John Maxwell >Sent: Monday, June 05, 2006 10:46 AM >To: [log in to unmask] >Subject: Re: [TN] Finding cracked capacitors > > >Daniel, >Most flex cracks are hidden under the termination at the capacitor >termination/PWA interrface making it very difficult to detect using SLAM >or C-SAM. A quick way to uncover cracks is exposure to humidity & bias >accelerating failure. A few temp cycles ahead of humidity testing will >open the cracks a bit easing humidity entering the capacitor body >accelerating failure. > >John Maxwell > > --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------