Bill -
Your slivers could have several root-causes. You've not said whether these
slivers are exclusively gold, or Ni/Au, or Cu/Ni/Au, so the possibilities
abound and include the condition of the electroplated gold (is it granular
in appearance? Does it remove easily to the touch, or with yank of
transparent tape?) and the overall thickness of the PCB. For the former, the
gold bath integrity might be an issue, or a passivity problem my exist with
the nickel, or the gold may have been plated to fast or even too thick. For
the latter, if the board itself is "too" thick for the connector gap, excess
loading force by the connector can cause the removal of gold by scraping
that could take the appearance of slivers. Other factors include an
over-etched connector pad or a connector pad that is over-plated with copper
(in the former, an undercutting of the pad profile can result in break-away
slivers along the sides of the connector pad; same with the latter except
cause is due to an outgrowth of electroplated copper). Still another
possibility may be the edge bevel is inadequate to facilitate insertion,
whereby loading force along the leading edge is causing some shear to the
(gold) plating, resulting in slivers.
You'll find your answer eventually; write back as to your conclusion.
Bob Lazzara
Circuit Connect Tech Support
Georgia Service Bureau
TEL: 800.560.9457 FAX: 888.453.0520 BBS: 603.889.5385
alternate eMail: [log in to unmask]
-----Original Message-----
From: Bill Davis <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Tuesday, February 02, 1999 1:12 PM
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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