I don't think this data is accurate. I'd contact MacDermid or Alpha and get
tech data on their immersion silver shelflife. 6-12 months under clean,
controlled conditions is more realistic.

-----Original Message-----
From: Reid, Lorraine [mailto:[log in to unmask]]
Sent: Wednesday, June 26, 2002 11:35 AM
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
----------------------------------------------------------------------------
-----

---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------