Dave,
Is it possible this is just an edge effect? You do get horrendous undercut
due to the different metals creating a cell effect which causes flaking at
the edges and could give the impression that gold is peeling off. If you are
using 1 oz or thicker copper the effect will be worse, 0.5 oz copper is
better with a fast etch speed and make sure the pH is not too high in the
ammoniacal etch.

I have never heard of baking curing an adhesion problem but your adhesion
could be borderline if the nickel is allowed to passivate before gold plate.
The panels must be transferred as quickly as possible with voltage applied
as they are immersed in the gold.

Good luck.
Paul Gould
Teknacron Circuits Ltd

-----Original Message-----
From: Modular Components National, Inc. <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: 04 August 1998 17:22
Subject: [TN] PEELING GOLD


> I have a question?
>Why if you plate a panel with NiAu then you do a
>tape test prior to your etch process and at that
>point the Au passes the test. After you etch the
>panel it then fails the tape test, now one more
>thing if you bake the panel at 300 F for one hour
>then do another tape test now you pass. So my
>question is should you always bake NiAu, or is
>that just a fix on a problem that we have with
>are plating process? Last thing guys when I say
>that it fails the tape test it is the adhesion
>between the NiAu. Any imput would be appreciated.
>
>
>Dave Blevins
>
>Modular Components National, Inc.
>2302 Industry Court
>Forest Hill, MD 2150
>PH (410) 879-6553
>Fax (410) 838-7629
>
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