Hi Bob - unfortunately you are going to lose the solderability of those
sheets somewhere in the 6-12 month time frame depending on which immersion
tin formulation you are using and due to diffusion issues will lose the
solderability of the sheets on a permanent basis somewhere in the 12-24
month time frame depending on the thickness of the immersion tin plating.
You may be able to "reactive" the surface for some other operation but you
will need to somehow make sure the surfaces to not passivate (aka oxidize)
preventing the next process operation. My recommendation is talk to your
favorite plating supplier. Good Luck.
Dave Hillman
Rockwell Collins
[log in to unmask]
bob wettermann <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
12/08/2009 11:11 AM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
bob wettermann <[log in to unmask]>
To
[log in to unmask]
cc
Subject
[TN] Storing of Copper Sheets
Dear Technetters:
If you planned on storing 10z copper sheets with a bright immersion tin
coating for several years in 24 x 24" sheets-how would you do it?
We have several internal opinions from interleaving of saver paper to
moisture barrier bags to other types of bags.
Thanks!
Bob Wettermann
PH 847-767-5745
---------------------------------------------------
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
-----------------------------------------------------