Steve -

I would not use any of these that show this condition.  DFSM is prone to
adhesion failures from lamination issues as well as surface conditions.
Adhesion issues at this stage indicate an acute problem with adhesion
and it appears from the micrographs to be from surface contamination.
This condition will likely propagate from assembly and operation of the
unit over time.  

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: Stephen Gregory [mailto:[log in to unmask]] 
Sent: Thursday, June 02, 2005 10:51 AM
To: [log in to unmask]
Subject: [TN] Dry Film Soda Strawing...

Mornin' all ya'll...

We've got some boards in here with dry-film mask "soda strawing".
I've got pictures up on my page at: http:// www.stevezeva.homestead.com
and look at "Soda Strawing, Soda Strawing 2, 3, and 4".

These are class 3 boards and I say that if there's any evidence of soda
strawing
it's nonconforming, no matter if the soda straw is completely sealed or
even if it
doesn't reduce the conductor spacing below the minimum requirements.

If you see it on a class 3 board, it's rejectable according to the
IPC-600G
is the way I
read it...am I wrong?

BTW, I'm definately rejecting the board in the picture "Soda Strawing
4".
That picture
is over a planar transformer pattern and has the trace exposed. The
other
three pictures
are the different degrees of soda strawing that I'm seeing...is any of
it
acceptable?

Kind regards,

-Steve Gregory-
Senior Process Engineer
LaBarge Incorporated
Tulsa, Oklahoma
(918) 459-2285
(918) 459-2350 FAX
__________________________________________________________________
This message may contain information that is privileged and confidential
to
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above.
If you are not the intended recipient, you may not copy, use or deliver
this message to anyone.  In such event, you should destroy the message
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