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 >A good acoustic microscope should be able to find these cracks quickly and >non-destructively. It is not a cheap tool, though, at $100k-$200k depending >on the options. > >On Mon, 5 Jun 2006 10:11:04 -0400, Tempea, Ioan <[log in to unmask]> wrote: > > > >>Hi Technos, >> >>a never ending story, ceramic caps that crack, possibly due to >> >> >depanelizing. The damage is not visible, unless the cap is cross sectioned. > > >>Is there any testing, thermal cycling or something like that, that could >> >> >show the damage real fast? > > >>Thanks, >> >>Ioan >> >> --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------