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February 1999

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Subject:
From:
Paul Gould <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 3 Feb 1999 09:27:42 -0000
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Hi Bill,

Assuming these slivers are not delamination, in which case you will
see copper or nickel exposed on the surface of the contact finger,
then my guess is that these were gold plated before etch and the
resulting etch undercut has left a gold overhang which can then break
off. If this is the case, the sides of the contacts will have exposed
copper showing.

I have seen this when using gold as an etch resist and you have to use
thin base copper foil to minimise undercut. The standard method of
plating edge connectors is to plate them after etch provided you can
connect a plating bar to all the connector fingers.

Hope this helps,
Paul Gould
Teknacron Circuits Ltd
www.teknacron.com

-----Original Message-----
From: Bill Davis <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: 02 February 1999 18:11
Subject: [TN] Gold Finger Slivers


>Hi Techies!
>
>I am getting slivers off the edges of gold fingers on the PCB edge
>connector. These slivers appear when the board is inserted into a
>standard PC system. Any background available on your experiences
(cause,
>solutions containment activities/screens, etc.) would be appreciated.
>
>Thanks & regards,
>
>> Bill Davis, Ph.D.
>> Diamond Multimedia Systems
>> Senior Scientist
>> Tel. 408.325.7868
>> Cell. 408.888.5650
>> e-mail: [log in to unmask]

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