Bruce:

My understanding of Black Pad was it is caused by too much phosphorus in the nickel (as I recall) plating bath.
Solder mask contamination is a new one for me.
With mask going on after the gold, how does it contaminate the nickel? Mask should not come in contact with the nickel at all in my experience

I am interested in learning all nuances of black pad causation.
Would appreciate your comments.

Charlie McMahon

Misner, Bruce wrote:
[log in to unmask]"> 
Congratulations. Sounds like you are the proud owner of Black Pad Disease or
better known as Black-line Nickel (BLN), an unpredictable low-level defect
of ENIG. It has been traced to electroless nickel plating bath contamination
by uncured soldermask, although I'm not convinced this is the only cause.

Good Luck,
Bruce Misner

----------
From:         Marki Sasportas[[log in to unmask]">SMTP:[log in to unmask]]
Reply To:     TechNet E-Mail Forum.;Marki Sasportas
Sent:         Monday, July 22, 2002 8:03 AM
To:   [log in to unmask]
Subject:      [TN] Au-Ni coating

Hello All,

I have problem in BGA rework, In some cases after, heating specific zone
on
the board ( gold finish)
A near BGA joints are being defected. After taking off this BGA I noticed
that some of the pads are black,
What can cause the problem?

Thanks in advance,
Sasportas Marki,
CreoScitex Corporation Ltd.

--------------------------------------------------------------------------
-------
Technet Mail List provided as a free 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/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 1.8e
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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------