Mike is absolutely correct but I think based on the discussions in this thread we need to define acceptance criteria for FOLDS.

-----Original Message-----
From: Michael E. Hill [mailto:[log in to unmask]]
Sent: Thursday, August 11, 2005 11:48 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] Request for Plating Definitions for IPC-T-50




We all have to remember this is a "definition" so folks can speak in the
right language and is NOT tied to any requirements. The requirements will be
tied to these terms/definitions in 6012.

Mike

-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]]On Behalf Of Denny
Cantwell
Sent: Thursday, August 11, 2005 9:52 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] Request for Plating Definitions for IPC-T-50


To all of the group:

Susan has provided some very good photos of foldovers, but I personally
have a heartburn issue with the term "healed folds".  During the time
that the crevice is in the copper plating bath, there is plating
solution down to the base of the crevice, and when the copper plates
over and meets the opposite side, this plating solution is permanently
trapped in the fold.  An electrolytic solution trapped within a board at
the PTH interfaces is pretty 'sick" to me.  The thermal excursions of
assembly will turn the solution to steam, causing blowouts, copper
cracks, and ionic contamination, none of which is good for a PWB.  The
electrolytic solution may contribute to CAF failures under the influence
of the voltage in the PTH, especially when the crevices are at the glass
bundles, which is typically where they occur.  Boards with the plating
down to the base of the crevice should be acceptable "foldovers", but
boards with voids behind the plating should be rejectable.  The
IPC600/6012 committee should consider this for inclusion in the next
versions of these specs, and maybe use Susan's photos for "reject"
conditions.

Dennis J. Cantwell
R & D Liaison
Printed Circuits, Inc.
1200 West 96th Street
Minneapolis, MN 55431-2699
952-888-7900
[log in to unmask]


-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Susan
Mansilla
Sent: Wednesday, August 10, 2005 2:28 PM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] Request for Plating Definitions for IPC-T-50


Here are three photos - two of "healed" folds and one that is open

Susan Mansilla
Robisan Laboratory, Inc