My opinion is that missing holes were found at image and the panels
returned to drill for rework.  Being difficult to find the last know
good drill location the panels were likely re-drilled with the same tool
again causing the location deltas that you see.  Not an issues are long
at the PTH conditions meet the performance requirements - I would pull a
x-section of a few of these sites and evaluate the through hole
characteristics.

Jeffrey Bush
Director, Quality Assurance and Technical Support

VERMONT CIRCUITS INCORPORATED
  76 Technology Drive - POB 1890
    Brattleboro, Vermont 05302
      Voice: 802.257.4571.21 Fax: 802.257.0011
           http://www.vtcircuits.com
 

-----Original Message-----
From: Ryan Grant [mailto:[log in to unmask]] 
Sent: Tuesday, April 26, 2005 11:24 AM
To: [log in to unmask]
Subject: [TN] Oval via holes

Hi Technetters,

Our AQL department discovered some boards that they thought might be
annular ring violations.  Although they are admittedly ugly, the drilled
hole did not break out of the annular ring so they are in spec.
However, I noticed the drilled hole is oval shaped.  

It appears a drill bit may have broken and the panel was "re-drilled" to
ensure all holes are there.  Apparently, by random chance, some via
holes were not drilled in the exact same location, causing an oval hole.
In one hole, the second drill is offset from the first by 3/4ths the
diameter of the first drill.

Now I'm not sure what to make of it.  What are your opinions?  A little
weird looking but just fine?

Thanks,
Ryan Grant

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 1.8e
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
-----------------------------------------------------