Catherine,

I am not sure what you mean when you say it happens on most kinds of
laminates? It is possible that there is epoxy residues on the panels which
occurs during the manufacturing of the laminate if the lay up area is not a
clean room. However if you mean when you say that this is happening on most
kinds of laminates and you are referring to different laminate manufacturers
than I would say that it is a in-house problem and some where in your
pre-clean or etching operation you are introducing a surface contaminate.
May be something on the rollers.

Hope this helps

Scott Westheimer

----- Original Message -----
From: "Catherine Smith" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, January 27, 2004 1:15 PM
Subject: [TN] Low level shiny copper spots after cupric chloride etching


> Hello, can anybody help me please?  We are getting low level (up to 5
> microns high) copper spots left on inner layer panels after the cupric
> chloride etch.  It happens on most kinds of laminate.  We have put panels
> through our chemical clean line and the etch only and the effect is still
> there.  Leaving out the chemical clean line or pumicing the panels first
> still leaves the spots.  The surface is shiny copper and sometimes there
> appears to be some residue which we believe to be organic from a slight
> carbon peak on an EDAX scan.  We found some sticky residue on the rollers
> in the etcher which we removed, but the problem didn't go away.  We run at
> 4N HCl and 520mV, regenerating with hydrogen peroxide.
> Has anyone experienced this before?  Did you discover where the organic
> residue came from and the best way to remove it?
>
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