The most sensitive parts are the leadless ones, such as Vishay/Sprague 195D or 596D. I had some of these fail about 12 years ago and tried to contact them to see what I'd done to them or if there were any documented problems with that lot. At first, Sprague told me there was no such lot number, so I sent the Certificate of Compliance, which stated the lot number, and was signed by the Quality guy who told me there was no such lot number (the most ironic fact I have seen in this kind of situation) . This guy was much more interested in telling me I must have abused the part than helping me determine how I might have damaged it! I switched to Nichicon, which has better parts but longer lead times. Wayne Thayer ________________________________ From: TechNet on behalf of Stadem, Richard D. Sent: Wed 10/24/2007 1:37 PM To: [log in to unmask] Subject: Re: [TN] Surface Mount Tantalum Capacitor Repair and Rework--Risks Involved This type of rework should only be performed using either a hand-held hot air gun (Hakko) or use the hot gas rework station, and should only be done by a skilled operator. If the hot gas rework station is used, it is not usually necessary to include a board pre-heat stage, just a ramp-up to preheat the area from the top only using a small nozzle to direct the air flow in the immediate vicinity of the capacitor and then quickly lift it off. This can easily be accomplished without allowing the PWB temperature to go above 125C. MLCCC capacitors should use the same processes. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Chafin, Ken G. Sent: Wednesday, October 24, 2007 10:22 AM To: [log in to unmask] Subject: [TN] Surface Mount Tantalum Capacitor Repair and Rework--Risks Involved I would be interested in receiving any literature on the above subject. Approx. 8--9 years ago we encountered many failures because we outsourced some surface mount boards and the supplier did a lot of repair and replacement of SMT tantalum capacitors using soldering irons. Both Kemet and Vishay Sprague were helpful by providing Engineering Bulletins on the risks involved in the hand soldering of SMT tantalum Caps. We are again contemplating outsourcing this type of rework. We really need to know the risks involved in doing this and how best to do the rework if it must be done. Any documents (or personal experience) you think might help with this decision would be appreciated--- [log in to unmask] Thanks Kenneth Chafin --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 -----------------------------------------------------