Hi Robert,

Yep, multilayer for BGA application.  Is that standard practice?  Nobody
here has seen it before, and right now we're rejecting them.  Why would
anybody choose purple?

Glenn

-----Original Message-----
From: Robert B. Denbo [mailto:[log in to unmask]]
Sent: Thursday, May 16, 2002 10:54 AM
To: 'TechNet E-Mail Forum.'; 'Pelkey, Glenn'
Subject: RE: [TN] Board defect? Purple spot


Glen:

It sounds like someone put an extra hole in the board and filled it with a
purple epoxy. Is it a multilayer board where they might have been drilling
out an internal short?


Robert B. Denbo
Engineering Manager
Midwest Printed Circuit Services, Inc.
http://www.midwestpcb.com <http://www.midwestpcb.com/>
mailto:[log in to unmask] <mailto:[log in to unmask]>
847.740.4120
847.740.4187 Fax

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Pelkey, Glenn
Sent: Thursday, May 16, 2002 12:14 PM
To: [log in to unmask]
Subject: [TN] Board defect? Purple spot



Hi all,

        We just spotted a new board level defect, or is it?  It is a small,
about 25 mil diameter circle that is bright purple in color.  We dug one out
and found it goes all the way through the board.  Definitely no glass fiber
in this spot, and it shows some peeling on the edge where it meets the top
of the soldermask.

        So, we have our guess at what it is, but have any of you seen this
before?

Thanks in advance for any input.

Glenn