Thanks, Joyce.
Cu-S complex gonna creep along glass-epoxy interface or over solder resist surface?
The discoloration is creeping beyond via pad on appearance, but not corrosion product with naked eye checking. It is different from typical immersion silver creeping corrosion.
-----Original Message-----
From: Joyce Koo <[log in to unmask]>
To: [log in to unmask]
Sent: Wed, Nov 17, 2010 10:07 pm
Subject: Re: [TN] Radially discoloration on solder-resist covered via holes, why?
Cu-S complex. Residue etchant or other chemicals traped there. If they use UV
ure mask, un cured mask may have S containing chemicals that react with Cu.
nside via is difficult to cure. Just an off shot Guess.
-------------------------
ent using BlackBerry
---- Original Message -----
rom: Steve Gregory [mailto:[log in to unmask]]
ent: Wednesday, November 17, 2010 08:26 AM
o: [log in to unmask] <[log in to unmask]>
ubject: Re: [TN] Radially discoloration on solder-resist covered via holes,
hy?
Hi Colin,
The thing that confuses me, is that Charming said that the boards looked
ine after assembly, and it was only after the boards had been stored a
hile did they notice the dark areas around the vias. If it was thicker mask
ver the vias you should have seen that from the beginning, right?
Steve
-----Original Message-----
rom: TechNet [mailto:[log in to unmask]] On Behalf Of colin mcvean
ent: Tuesday, November 16, 2010 7:15 PM
o: [log in to unmask]
ubject: Re: [TN] Radially discoloration on solder-resist covered via holes,
hy?
I agree with the plugged via scenario....
The possible reason for "discolouration" could be the fact that the plugging
rocess is a seperate screening process, using a stencil screen with only
ias open. Normal PSR is then applied over the top of semi-cured plugged
ias, and process photomechanically. This would account for a thicker
eposition at the via hol area, and also the darker contrast of colour.
icrosection of the via hole would verify the situation....
My 2p worth
--- On Tue, 16/11/10, Bob Landman <[log in to unmask]> wrote:
rom: Bob Landman <[log in to unmask]>
ubject: Re: [TN] Radially discoloration on solder-resist covered via holes,
hy?
o: [log in to unmask]
ate: Tuesday, 16 November, 2010, 22:48
think you nailed it Inge. All the bad holes are plugged vias. The open
ias are very tightly registered.
Bob
-----Original Message-----
rom: TechNet [mailto:[log in to unmask]] On Behalf Of Inge
ent: Tuesday, November 16, 2010 2:11 PM
o: [log in to unmask]
ubject: Re: [TN] Radially discoloration on solder-resist covered via holes,
hy?
Had a brief look in some of our company papers about the second guess. We
bserved a difference between plugged and unplugged vias. The former were
iscolored like yours and it was caused by overtemperature (Leadfree!)
hich degraded the epoxy which bleeded out some stuff that discolerd the
oldermask. What chemistry process, I don't remember.
Inge
---- Original Message -----
rom: "Inge" <[log in to unmask]>
o: <[log in to unmask]>
ent: Tuesday, November 16, 2010 7:44 PM
ubject: Re: [TN] Radially discoloration on solder-resist covered via holes,
hy?
It may be what we name 'via halo' effects,which is caused by stress.
We do not accept.
It may also be caused by contaminations and/or improper drying.
/ Inge
----- Original Message -----
From: "Victor Hernandez" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, November 16, 2010 7:22 PM
Subject: Re: [TN] Radially discoloration on solder-resist covered via
holes, why?
Is there a higher mag photo of this anomaly. I need to see it, to call
it.
"X"
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ian Hanna
Sent: Tuesday, November 16, 2010 12:20 PM
To: [log in to unmask]
Subject: Re: [TN] Radially discoloration on solder-resist covered via
holes, why?
the discoloration is visible on top of the surface copper just right
of
R52 -- this suggests it is a surface condition of the mask or between
the mask and the surface copper and not an internal condition
Chuck Brummer <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
11/16/2010 01:14 PM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
[log in to unmask]
To
[log in to unmask]
cc
Subject
Re: [TN] Radially discoloration on solder-resist covered via holes, why?
Charming,
I think you need a micro section and it will reveal bad news. Rudy
may be
right or there may be an internal separation. Is this a multi layer?
I once saw a set of boards on which they spend to much time in the
glass etch and when copper plating the holes the copper wicked up the
glass fibers.
Chuck Brummer l 3M Manufacturing Engineer 3m Electronic Solutions
Division--Flexible Circuits
8357 Canoga Ave. l Canoga Park, CA 91304-2605
(818) 734-4930
[log in to unmask] l www.3m.com l www.3mFlex.com
From:
Steve Gregory <[log in to unmask]>
To:
<[log in to unmask]>
Date:
11/16/2010 08:48 AM
Subject:
Re: [TN] Radially discoloration on solder-resist covered via holes, why?
Sent by:
TechNet <[log in to unmask]>
Hi Charming,
I have your picture posted, it's here:
http://stevezeva.homestead.com/Pic1.JPG
Maybe they weren't cleaned well before solder masking?
Steve
From: Charming Chan [mailto:[log in to unmask]]
Sent: Tuesday, November 16, 2010 10:51 AM
To: [log in to unmask]
Subject: Radially discoloration on solder-resist covered via holes, why?
Hi Steve,
Would you help post the attached picture for me and forward this
message to TechNet? Thanks a lot.
The picture shows radially discoloration on solder-resist covered via
holes, while, the immersion silver pads without solder-paste reflowing
have shiny appearance with no discoloration. With naked eye checking,
the discoloration on solder-resist covered via holes is not corrosion
product.
BTW, the pcb board surface finish is immersion silver, via holes are
fully pluged with solder resist, and no discoloration is observed
after pcb assembly finished. The discoloration possibly gets start in
PCBA storaging.
Best Regarads
Charming Chan
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[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
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or
[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
-----------------------------------------------------
_____________________________________________________________________
his email has been scanned by the MessageLabs Email Security System.
or more information please contact helpdesk at x2960 or [log in to unmask]
_____________________________________________________________________
---------------------------------------------------
echnet Mail List provided as a service by IPC using LISTSERV 15.0 To
nsubscribe, send a message to [log in to unmask] with following text in the
ODY (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
OMAIL or (MAIL) To receive ONE mailing per day of all the posts: send
-mail to [log in to unmask]: SET Technet Digest Search the archives of
revious posts at: http://listserv.ipc.org/archives Please visit IPC web
ite http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
nformation, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
xt.2815
----------------------------------------------------
______________________________________________________________________
his email has been scanned by the MessageLabs Email Security System.
or more information please contact helpdesk at x2960 or [log in to unmask]
_____________________________________________________________________
---------------------------------------------------
echnet Mail List provided as a service by IPC using LISTSERV 15.0
o unsubscribe, send a message to [log in to unmask] with following text in
he BODY (NOT the subject field): SIGNOFF Technet
o temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
o receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
earch the archives of previous posts at: http://listserv.ipc.org/archives
lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
or additional information, or contact Keach Sasamori at [log in to unmask] or
47-615-7100 ext.2815
----------------------------------------------------
______________________________________________________________________
his email has been scanned by the MessageLabs Email Security System.
or more information please contact helpdesk at x2960 or [log in to unmask]
_____________________________________________________________________
---------------------------------------------------
echnet Mail List provided as a service by IPC using LISTSERV 15.0
o unsubscribe, send a message to [log in to unmask] with following text in
he BODY (NOT the subject field): SIGNOFF Technet
o temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
o receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
earch the archives of previous posts at: http://listserv.ipc.org/archives
lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
or additional information, or contact Keach Sasamori at [log in to unmask] or
47-615-7100 ext.2815
----------------------------------------------------
_____________________________________________________________________
his email has been scanned by the MessageLabs Email Security System.
or more information please contact helpdesk at x2960 or [log in to unmask]
_____________________________________________________________________
---------------------------------------------------
echnet Mail List provided as a service by IPC using LISTSERV 15.0
o unsubscribe, send a message to [log in to unmask] with following text in
he BODY (NOT the subject field): SIGNOFF Technet
o temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
o receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
earch the archives of previous posts at: http://listserv.ipc.org/archives
lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
dditional information, or contact Keach Sasamori at [log in to unmask] or
47-615-7100 ext.2815
----------------------------------------------------
---------------------------------------------------------------------
his transmission (including any attachments) may contain confidential
nformation, privileged material (including material protected by the
olicitor-client or other applicable privileges), or constitute non-public
nformation. Any use of this information by anyone other than the intended
ecipient is prohibited. If you have received this transmission in error, please
mmediately reply to the sender and delete this information from your system.
se, dissemination, distribution, or reproduction of this transmission by
nintended recipients is not authorized and may be unlawful.
______________________________________________________________________
his email has been scanned by the MessageLabs Email Security System.
or more information please contact helpdesk at x2960 or [log in to unmask]
_____________________________________________________________________
---------------------------------------------------
echnet Mail List provided as a service by IPC using LISTSERV 15.0
o unsubscribe, send a message to [log in to unmask] with following text in
he BODY (NOT the subject field): SIGNOFF Technet
o temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
o receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
earch the archives of previous posts at: http://listserv.ipc.org/archives
lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
dditional information, or contact Keach Sasamori at [log in to unmask] or
47-615-7100 ext.2815
----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [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
-----------------------------------------------------
|
