Good Mornin' Ramon! They have! Check out this: http://www.avxcorp.com/docs/Catalogs/softterm.pdf Kind regards, -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dehoyos, Ramon Sent: Wednesday, June 14, 2006 8:08 AM To: [log in to unmask] Subject: Re: [TN] Finding cracked capacitors It seems to me that it is time for the manufacturers of ceramic caps to get back to the drawing board and redesign the caps so that this problems is resolved by getting to the root cause. Some kind of strain relief termination so that the cap is not susceptible to stresses. I can think of more than one way to do that but the manufacturers have the resources in place to make the changes and come out with the best resolution. Ramon -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Camille Good Sent: Tuesday, June 13, 2006 3:03 PM To: [log in to unmask] Subject: Re: [TN] Finding cracked capacitors Using the hot soldering iron approach can cause a number of problems, many of which have been described in previous posts. I've also seen a case where a hot soldering iron caused the cracked capacitors to self-heal (temporarily) - the heat drove out any water that had worked its way into the cap due to a high-humidity operating environment, and that in turn got rid of the leakage current problems we were having. At the time, we didn't know that the issue was a cracked capacitor, so it was maddening to troubleshoot the product. The product clearly was not working correctly, but the instant you touched that area of the PCB with a soldering iron (and there were a number of components all in parallel with the capacitor) the problem went away and the product started working fine. -Camille I saw a product a couple years ago that had problems due to cracked capacitors. The problem only showed up in high humidity situations, where the presence of high humidity would cause an increase in the leakage current of the capacitor. This increased leakage current sucked away enough power from other components that the part wouldn't work correctly in certain conditions. The worst part was that as soon as we touched that particular PCB no Dale Ritzen <[log in to unmask]> wrote: 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 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 ----------------------------------------------------- __________________________________________________ Do You Yahoo!? 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