Matthew,

We run silver process on our bare PWB's, although not MacDermid Sterling
with peelable masks all the time with no tarnishing issues.
It would suggest that the Silver surface is not clean enough, possible
presence of chlorides etc (we use DI rinsing) prior to the baking
process, or the temperature in the oven is getting too high, or more
likely, that the solvents and fumes are not being extracted in the oven
during the curing process, hence tarnishing the silver coating.


Colin McVean
Production Manager
Artetch Circuits Limited
Tel: 01903 725365

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Matthew Lamkin
Sent: 25 February 2005 10:21
To: [log in to unmask]
Subject: [TN] Peelable mask on Sterling Silver coatings?

Hello, has anyone any experiences of peelable mask on MacDermid Sterling
Silver coated FR4 boards?

We have just been going through the process of changing our board spec
to silver coating for all, but the peelable process seems to give us a
bit of a problem.

AFAIK The peelable goes through an oven to cure it, which seems to
tarnish the silver.

Has anyone any recommendations/suggestions that I can pass onto our
supplier
to allow us to have our boards that use peelable silver coated too?

Thankyou,
Matthew Lamkin.

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