Yes, I have seen this phenomenon at FLUKE.  Fortunately, it is not a
pervasive problem, but it is puzzling.  We have not yet determined the exact
cause.  I will revisit the subject with our Innerlayer Dry Film/Etch Process
Engineer and get back to you, if warranted.

-- Fred

-----Original Message-----
From: Eric Masters [mailto:[log in to unmask]]
Sent: Friday, October 01, 1999 12:06 AM
To: [log in to unmask]
Subject: [TN] Internal shorts


I'm having a rather perplexing problem with shorts on inner layers.  The
short is very small, and occurs mainly on fine line jobs (5/5 mils and
less).
 It also occurs primarily on layers with one ounce copper, although I've
seen
it on half ounce.

The short is very very small; in fact, it is rarely seen at AOI.  Usually,
it
is discovered at final electrical test.  Failure analysis exhibits a very
fine sliver of copper that appears to have broken loose from a trace; it
remains attached at one end and flips across the adjacent circuit.

Cross sections and SEM's of both developed resist and etched layers show a
near vertical sidewall.  Has anyone seen this phenomenon?  Any suggestions?

Eric

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################