Werner,
I'm also not a great fan of ENIG and agree that HASL should work much
better than trying to remove the Ni. However, I do think that your
comment about Au-embrittlement isn't correct. Yes, when the HASL
process is finished there is only a small volume of solder on the Ni but
when you dip boards into a vertical HASL machine that has hundreds of
pounds of solder or when you flow solder onto a board in a horizontal
HASL process and blow off the excess the small amount of immersion gold
will dissolve rapidly into the flowing solder and be carried away. The
HASL process is actually a gold removal process and once you go through
a surface mount solder paste stencil and reflow process there isn't a
small amount of solder and in fact the percentage of Au in a solder
joint formed on an ENIG board that was processed through HASL would be
less than the percentage of Au in a solder joint formed on an ENIG
board.
Regards,
George
George M. Wenger, Andrew Corporation
Reliability / FMA Engineer
Base Station & Subsystems Group
40 Technology Drive, Warren, NJ 07059
(908) 546-4531 [log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
Sent: Wednesday, August 17, 2005 10:42 PM
To: [log in to unmask]
Subject: Re: [TN] HASL over nickel
Hi,
Many people have successfully used ENIG [as long as the Ni electrical
properties are no problem for your application]. I am not a great fan of
ENIG, but it
should work much better than trying to remove the Ni. Certainly, HASL
can be
applied over ENIG, however, with that small volume of solder,
Au-embrittlement
cannot be positively excluided.
Regards,
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com
---------------------------------------------------
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
-----------------------------------------------------
------------------------------------------------------------------------------------------------
This message is for the designated recipient only and may
contain privileged, proprietary, or otherwise private information.
If you have received it in error, please notify the sender
immediately and delete the original. Any unauthorized use of
this email is prohibited.
------------------------------------------------------------------------------------------------
[mf2]
---------------------------------------------------
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
-----------------------------------------------------
|
