At 03:18 PM 7/31/98 -0400, you wrote:
>I would think it wise to address the problem from a chemistry standpoint
>or use an alternate surface finish before going the electroplated Nickel
>route.  You will immediately either alienate or disqualify most of your
>PCB suppliers.  Using electroplate requires surface continuity (unless
>you're fortunate enough to have a design that is internally bussed, very
>unlikely!)  so you're generally forced to do a body plate prior to
>surface cu foil etch,  This most likely would entail the inclusion of an
>electrolytic gold flash as well because the nickel would be difficult if
>not impossible to re-activate if you were trying to utilize an immersion
>gold process later on.  Not only will line definition suffer,  you run
>the risk of  nickel slivers after etch, and lastly I doubt most profit
>margins  will warrant the additional expense of body plated gold!!
>
We do run this process, i.e. body plated bright electrolytic nickel which
serves as etch resist , then soldermask and immersion gold (Oromerse MN) on
the exposed pads and thru-holes only. Applications are surface mount where
a requirement for nickel-gold as a contact surface also exists,
solderability is excellent, several passes OK. Activating the nickel just
before gold is the key; we found a product called NiACT from Surface Tek to
be effective and reliable.


George Anderson
President
Uvonics Co. Inc.
2162 McKinley Ave.
Columbus, Ohio 43204            (614) 274-0040
<[log in to unmask]>           http://www.uvonics.com

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