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Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 6 Oct 1998 10:35:26 -0400 |
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Roger:
How then does copper thieving affect throwing power? Is it correct to surmise that copper thieving would
serve to enhance throwing power by allowing a more uniform current density across a panel, thus resulting
in a more uniform plating thickness?
Roger Mouton wrote:
> Jacob -
>
> The term throwing power is often misused. It refers to the uniformity of a
> deposit thickness over a varying current density range. It's often confused
> with the cosmetic uniformity achieved when the deposit "looks" the same in the
> high and low current density areas of a cathode.
>
> Good throwing power would thus be achieved when the deposit on a circuit board
> is 1 mil in the hole and 1 mil on the surface.....everywhere on the board.
> Or, 1 mil on the surface and 1 mil in the bottom of a blind via hole,
> especially a deep one. That's good throwing power. Thought of another way:
> uniform plating thickness distribution in any cavity or blind area where there
> is a disparity of current distribution from high to low current density areas.
> Stay put and see what else shows up on this question. It can elicit a
> multitude of responses.
>
> Roger Mouton
>
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