John,
PCI does not supply any boards that are "Bare Copper". But we do supply
"bare copper covered with OSP" to users that so specify.  In vias that
are solder pasted, the surface tension of the solder would displace any
chemistries that were in the hole (flux, solvents, etc), so that is not
a valid concern.

Dennis J. Cantwell
R & D Liaison
Printed Circuits, Inc.
1200 West 96th Street
Minneapolis, MN 55431-2699
952-888-7900
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-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of John Perry
Sent: Monday, February 04, 2008 2:53 PM
To: [log in to unmask]
Subject: [IPC-600-6012] Bare Copper as a Surface Finish

Colleagues,

 

Our IPC-6012B specification provides for bare copper as a final finish
in Table 3-2, Final Finish, Surface Plating and Coating Thickness
Requirements.

 

The task group is evaluating whether or not this should be removed from
Table 3-2 in the future IPC-6012 Revision C.  Among the concerns with
bare copper are instances of single-sided via protection that provides
for entrapment of chemistries that attack the bare copper in the hole
wall.

 

If there are those of you out there who use bare copper as a surface
finish, could you provide feedback to IPC as to how it is used in your
applications?

 

Thanks in advance,

 

John Perry

Technical Project Manager

IPC

3000 Lakeside Drive # 309S

Bannockburn, IL 60015

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1-847-597-2818 (P)

1-847-615-7105 (F)

1-847-615-7100 (Main)