Kathy,
Although the pictures are a bit difficult to determine, it could be a
classic
case of severe "pink ring". Do all vias top and bottom exhibit this
phenonom,
or is it isolated to one side? How thick is the PCB? As you stated you will
be performing a cross section
which should reveal the truth. Keep us posted.

Tony
----- Original Message -----
From: Kathy Kuhlow <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, February 05, 2002 11:23 AM
Subject: [TN] PCB Question


I have a few assemblies that a customer had asked me to look at and I
noticed an oddity around the vias.  It looks like there is delamination
around the vias.  Steve was kind enough to post these photo's on his web
page for all to view.  I need to know if this is delamination or just
haloing. I saw an issue like this a long time ago (15 years ago) and at that
time we scrapped them because we didn't know what the issue was caused by.
Some at that time thought the drill bit for that size was either pushed to
fast through the material causing a slight delanmination or the drill bit
was dull.

I appreciate any assistance or thoughts on the issue.  I have already
suggested that a cross section may have to be completed.

http://www.stevezeva.homestead.com

Thanks in advance.

Kathy

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------