Steve

I can't tell you about adhesion problems because we've never evaluated
putting SM over silver.  The immersion silver surface finishes I'm aware of
have a co-deposited solderability preservative added to them.  This
preservative is thermally sensitive and can be destroyed by operations like
soldermask curing.

The boards are likely still solderable now, but you probably want to
assemble them fairly quickly.  I don't recommend storing any unused boards
for an extended period.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stephen M. Vargas
Sent: Friday, April 01, 2005 5:42 AM
To: [log in to unmask]
Subject: [TN] Immersion Silver

Good Day All:

    A question arose at our factory regarding immersion silver surface
finish. We received boards where the solder masking was applied after the
immersion silver was applied to the PWB. Are there potential solder mask
adhesion issues with this? Should the solder mask be applied prior to
adding the surface finish? Any insight would be appreciated. Thanks.

Regards,
Steve Vargas

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