Dan,

What do you mean by "lack of plating" exactly? Are you seeing copper? (and
what color, shade, etc is the copper) Are you seeing another color? (and
what would this color be).

There are myriad reasons for failure to coat pads, and while I have not
documented evidence, I would not think nets being "charged" interfering with
the ion exchange as the cause. Usually, when we look at all the information
it is a pretty straightforward root cause.

Describe for us the color of the pads, also, did you happen to do any
solderability of these affected pads, if so what were the results?

Franklin

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Dan Skweres
Sent: Monday, September 18, 2006 4:54 PM
To: [log in to unmask]
Subject: [TN] ENIG

We have, at times, had an outside plating service have difficulties with
plating of ENIG on our bare boards. The interesting anomaly we have
encountered is lack of plating on certain pads. They tell us there is
something on the surface of the pads but when they return the panels to us
we micro etch (copper looks beautiful) and all pads look similar in
appearance. We even took a panel and coated immersion white tin with out
problems. This tells me that there isn't any thing on the surface of the
copper. There is one thing I did leave out. The pads that aren't taking ENIG
all happen to be in the same net. Has anyone encountered this? It's almost
like there is a charge being created in certain nets not allowing the ion
exchange to happen. Could it be entrapped chemistry within vias? Any help
and/or direction would be greatly appreciated.
Thanks,


Dan Skweres
Engineering Manager
Bartlett Manufacturing
Phone:847-639-2102 Ext.#230
Fax:847-639-8838


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