Dave & Co.
I noticed it too. I have no information on what the boards saw before
testing. My initial impressions was that this was a "virgin" board that
did not see any thermal or mechanical stresses. So I kind of flying in
the dark on this one.
I'm confident that it is not Black Pad - I've seen that and this does
not register. A possible thought was that there was some contamination
in the Ni bath - I've seen that here too - but the cross-sections did
not show any.
Assuming that it was mechanically stressed, the pads in question were
not at the edge of the board but 2-3 rows into the board. There were
mounting screws holes in the area, but did the hardware mounting process
cause the problem - it is conceivable but there is not sufficient
information to clearly identify the root cause.
Like I told someone earlier, what you see is what I got...
Thanks for all the inputs.
(NTC) Spring training and the Daytona 500 starts Sunday...
Lee Whiteman, PMP
Senior Member Engineering Staff
L-3 Communications East
Telephone: (856) 338-3508
FAX: (856) 338-2906
E-Mail: [log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
Sent: Wednesday, February 11, 2009 5:33 PM
To: [log in to unmask]
Subject: Re: [TN] CRACKED ENIG PADS
Hi folks! Hey Lee, in one of the pictures, there looks to be mounting
hardware for a connector on the left side of the picture. Did you notice
that the cracks shown in the pth close-up are on the pth left side (the
side closest to that mounting hardware) and that there are nearly no
cracks on the pth right side (the side that is away from the mounting
hardware)! Humm, ya might want to see what the mounting hardware torque
requirements are and what tooling is being used. Just a guess.
Dave Hillman
Rockwell Collins
[log in to unmask]
"Stadem, Richard D." <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
02/11/2009 03:31 PM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
"Stadem, Richard D." <[log in to unmask]>
To
[log in to unmask]
cc
Subject
Re: [TN] CRACKED ENIG PADS
Vladimer is correct. They are cracks in the nickel/gold layer that
extend down to the copper and stop there. The reason is that the nickel
is a much more brittle or non-ductile material than either the gold or
the copper. The copper will bend somewhat if the board is stressed, but
the nickel will not, it cracks. The gold is so thin on true ENIG (3-5
uinches) that when the nickel cracks the gold is literally torn apart.
The copper does not crack easily.
So the board was subject to some type of flexural stress that caused the
nickel to crack, and the direction of the flexure determines the portion
of the annular ring upon which the hard nickel is going to crack. That
is why in this particular picture the cracks are concentrated on one
side of the annular ring.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev
Sent: Wednesday, February 11, 2009 2:41 PM
To: [log in to unmask]
Subject: Re: [TN] CRACKED ENIG PADS
Lee,
Without seeing the actual cross-sections it's impossible to say what is
the root cause. If you are not happy with the lab report, you can send
me the part and I'll do it.
Regards,
Vladimir
SENTEC
11 Canadian Road, Unit 7.
Scarborough, ON M1R 5G1
Tel: (416) 899-1882
Fax: (905) 882-8812
www.sentec.ca
-----Original Message-----
From: Lee Whiteman <[log in to unmask]>
Date: Wed, 11 Feb 2009 14:41:46
To: <[log in to unmask]>
Subject: Re: [TN] CRACKED ENIG PADS
Victor, George, Vladimir, and Company
Steve should be attaching the cross-section photograph. Since I did not
supervise the cross-sectioning activity, I will not vouch on the quality
of the cross-section.
I do see a layer (crack?) between the ENIG plating and the copper
surface, but the report that I received indicated that there was "no
evidence of a lack of bonding" - the lab reports words. That layer
(crack?) seems more pronounced than similar ENIG cross-sections I have
seen.
Lee Whiteman, PMP
Senior Member Engineering Staff
L-3 Communications East
Telephone: (856) 338-3508
FAX: (856) 338-2906
E-Mail: [log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Victor Hernandez
Sent: Wednesday, February 11, 2009 2:23 PM
To: [log in to unmask]
Subject: Re: [TN] CRACKED ENIG PADS
Can you share the photos of the cross section?
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wenger, George M.
Sent: Wednesday, February 11, 2009 12:51 PM
To: [log in to unmask]
Subject: Re: [TN] CRACKED ENIG PADS
Lee,
When you say "Evidently" that you have done cro
Lee,
When you say "Evidently" that you have done cross sectioning and see
that the cracks are only in the Ni and Au and not in the Cu? Since you
said "There was no evidence of a lack of bonding between the copper and
the ENIG finish" that implies to me that you did cross section but since
I wasn't sure I thought I'd ask.
Regards,
George
George M. Wenger
Andrew Wireless Solutions
Senior Principal FMA/Reliability Engineer 40 Technology Drive, Warren,
NJ 07059
(908) 546-4531 (Office) (732) 309-8964 (cell) [log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Wednesday, February 11, 2009 1:42 PM
To: [log in to unmask]
Subject: Re: [TN] CRACKED ENIG PADS
Hi Lee!
Have your pictures posted. They are here:
http://stevezeva.homestead.com/files/THROUGH_HOLE_CRACKS-1.jpg
http://stevezeva.homestead.com/files/THROUGH_HOLE_CRACKS-2.jpg
I have to let those that know more about plating than I do answer this
one...
Steve
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee Whiteman
Sent: Wednesday, February 11, 2009 12:20 PM
To: [log in to unmask]
Subject: [TN] CRACKED ENIG PADS
I have asked Steve to put up a pair of pictures I received. They are of
cracks within the ENIG finish of a PWB. I know that the board failed,
based on IPC-6011 and IPC-6012.
My question is what would cause the cracking? Evidently, it is in the
Nickel layer and the copper layer was not compromised. There was no
evidence of a lack of bonding between the copper and the ENIG finish.
These boards are fresh from the supplier.
Just curious...
Thanks in advance.
Lee Whiteman, PMP
Senior Member Engineering Staff
L-3 Communications East
Telephone: (856) 338-3508
FAX: (856) 338-2906
E-Mail: [log in to unmask]
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 15.0 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 15.0 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 15.0
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 15.0
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 15.0
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
-----------------------------------------------------
|
