Hello Lorraine, Can't help you with the articles, but we have an immersion tin board that has been sitting on a shelf for the last 12 months that at least still appears to be solderable. (still bright - no blackening) It was packaged in a heat sealed plastic wrap by our supplier. Unwrapped boards exhibit tarnishing after a few months - less if handled. regards, Phil. Phil Dutton C.I.D. Senior CAD Technician IPC Certified Interconnect Designer Tenix Defence Pty Ltd Electronic Systems Division Second Avenue, Technology Park, Mawson Lakes. SOUTH AUSTRALIA 5095 -----Original Message----- From: Reid, Lorraine [mailto:[log in to unmask]] Sent: Thursday, 27 June 2002 01:05 To: [log in to unmask] Subject: [TN] Shelf life of Immersion Silver Fabs A couple of months ago there was a discussion thread running on the merits of immersion silver boards. One of the contributors (Jack Olson, I think) made the comment that - "Most sources say a silver surface will not be solderable after a month or so unprotected. (Even in a baggie it will be okay a year later?)" What are these "sources"? Are there published articles giving guidelines on how fabs should be packed to maximise shelf-life? Basically, we've just received some Immersion Silver boards from fab house which were wrapped in tissue paper then bubble-wrap. Not in sealed bags or anything. They claim boards should be OK, even though we won't be using all supplied boards for a few months. They have offered to repackage if we insist on it. I'm a little concerned, having seen how Immersion Silver boards can easily tarnish. I'd be interested to hear what TechNet contributors have to say on this matter. Thanks in advance for your replies Lorraine Reid Senior Electronics Engineer Trivirix International tel. +44 (0)28 9096 0932 - --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------