TECHNET Archives

June 2007

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:
Kerry McMullen <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Tue, 5 Jun 2007 11:38:45 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (87 lines)
Hi Tom,
Check the plating spec on the fab.   The plating thickness in the via's 
should be specified at 0.001" absolute minimum if you are going with LF 
processes, regardless of the board material.   (That is what I am told). I 
have made this change on my large 18+ layer boards, and my quality/yields 
have increased, and my opens have practically diappeared.

Kerry McMullen
Principal New Product Mfg. Engineer
LTX Corporation
825 University Avenue
Norwood, MA 02062-2643
(T) 781-467-5468
(C) 508-631-1832
(F) 781-461-0993



Tom Parkinson <[log in to unmask]> 
Sent by: TechNet <[log in to unmask]>
06/05/2007 10:13 AM
Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
Tom Parkinson <[log in to unmask]>


To
[log in to unmask]
cc

Subject
[TN] Via Open






Tech Net & Designer Net

Greetings. We are running into a situation on Lead Free processed PCBs.
Failure mode is finding open vias during unit testing (fully populated).

Boards are Tg170, Material type EM320, 0.063" thick boards. 
6 layers of 1 oz copper. ENIG 3~5u"

Suspect vias go from top layer to bottom layer only.

After running through reflow, we have found vias open. No visual signs of
delamination, however when ohming out the via, if we press on the via we 
get
continuity - thus we suspect the vias are opening during the process.

Anyone out there having these problems, or information concerning this
failure mode?  Z-expansion failure?


Tom Parkinson 
Quality System Manager - CIT
WinTronics, Inc.
Phone: 724-981-5770 - extension 235

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

ATOM RSS1 RSS2