TECHNET Archives

January 2002

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 31 Jan 2002 11:03:53 +0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (101 lines)
Rick,

I went through this pain a while ago, and got a lot of tremendous help from
Ingemar Hernefjord in particular. I believe there is no released standard
for ENIG, though there is an empirical spec IPC-4552. It does not contain a
lot of useful detail, though. I specify 5 microinches (0.12 microns) of
Gold over minimum 235 microinches (6 microns) Nickel for my boards, after
reading a number of studies and failure reports. In fact I was recommended
to use 250 microinches of Nickel, but this would have made our boards too
thick. The thicker gold layer minimises porosity and therefore oxidation to
the underlying Nickel layer.

Older thinking was for around 100 to 120 microinches Nickel, but studies by
Eriksson and others concluded that with the growth of gold flashing through
the Nickel from one side and Cu/Ni intermetallics on the other side of the
plating, that a thicker Nickel layer would offer the boards a longer
solderability shelf life and greater solder joint reliability.

Hope this helps a bit. Certainly, I haven't experienced any problems with
soldering or mounting of components on boards to this spec.

Peter




                    Rick Thompson
                    <rthompson@VENTURAELECTR        To:     [log in to unmask]
                    ONICS.COM>                      cc:     (bcc: DUNCAN Peter/Asst Prin Engr/ST
                    Sent by: TechNet                Aero/ST Group)
                    <[log in to unmask]>               Subject:     [TN] ENIG Thickness Standard?


                    01/31/02 08:36 AM
                    Please respond to
                    "TechNet E-Mail Forum.";
                    Please respond to Rick
                    Thompson






Is there a standard for the plating thickness of the ENIG surface
finish?  I've searched the archives and didn't find anything.  Based on
a customer request we had increased the requirement for the electroless
nickel to 200u inches. A couple of our board vendors are telling me that
that is excessive and that anything over 100u inches is overkill. I've
seen references in the archives for anything from 120u inches to 200u
inches.  What (if anything) is considered standard for this finish?

Thanks for your inputs.


Rick Thompson
Ventura Electronics Assembly
2655 Park Center Dr.
Simi Valley, CA 93065

+1 (805) 584-9858   x-304  voice
+1 (805) 584-1529 fax
[log in to unmask]

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

Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send e-mail to [log in to unmask]:
SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail 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
---------------------------------------------------------------------------------





[This e-mail is confidential and may also be privileged. If you are not the
intended recipient, please delete it and notify us immediately; you should
not copy or use it for any purpose, nor disclose its contents to any other
person. Thank you.]

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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
---------------------------------------------------------------------------------

ATOM RSS1 RSS2