That last sentence was a perfect Deweyism. I'm proud of you.
Dewey
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Fox, Ian
Sent: Thursday, October 09, 2008 8:03 AM
To: [log in to unmask]
Subject: Re: [TN] PCB pad non-wetting issues
Judging by the analysis it's an ENIG board. Precursor to black pad I'd
say. You quite often see this post wave on poor ENIG. The relatively
quiescent nature of a reflow process is fine, the solder stays wetted,
as it does in the PTH, but the dynamic nature of a wave pulls the solder
off the contact pad. I'd carry out a good x-section and see what the lie
of the land is.
Regards
Ian Fox
Goodrich ECS
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Nutting
Sent: 09 October 2008 15:13
To: [log in to unmask]
Subject: Re: [TN] PCB pad non-wetting issues
Paymon,
To fill some of the details; what is the finish plating of the board,
what is the solder being used and what is the flux being used?
This will help. In the past there has been discussion about immersion
tin oxidizing during an initial heat cycle (SMT) and then not being able
to solder the PTH parts.
Phil
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paymon Sani
Sent: Thursday, October 09, 2008 9:57 AM
To: [log in to unmask]
Subject: [TN] PCB pad non-wetting issues
Hello All,
We are experiencing a pad non-wetting issue for the though-hole
component pads ONLY! The PCB goes through few heat cycles with top and
bottom side assembly during at SMT process and then through-hole
assembly at wave process. The problem is found at Wave process. The Pb
solder does not wet to the through-hole component pads on the solder
side only! An SEM/EDS evaluation revealed high concentration of P in the
Nickel and Nickel/Tin intermetalic layer of 11% to 21%. I would like to
ask anyone if they have experienced a similar defect in the past. What
is the Root Cause?
Thank you in advance,
Paymon
---------------------------------------------------
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
-----------------------------------------------------
Note: All the information contained in this e-mail and its attachments
is proprietary to Kaiser Systems, Inc. and it may not be reproduced
without the prior written permission of sender. If you have received
this email in error, please immediately return it to sender and delete
the copy you received.
---------------------------------------------------
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
-----------------------------------------------------
------------------------------------------------------------------------
--
Goodrich Control Systems Limited.
Registered Office: Stratford Road, Solihull, West Midlands, B90 4LA.
Registered in England No. 04482312.
------------------------------------------------------------------------
--
---------------------------------------------------
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
-----------------------------------------------------
|
