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Reply To: | TechNet E-Mail Forum. |
Date: | Fri, 6 Apr 2001 07:32:33 -0500 |
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Eric,
I have to concur with the two recommendations given by Rudy and Brian.
And of course, their assessment of the situation. I was curious how
your results would be if you turned off your pumps in the replenisher
chamber. You could then run a double pass through your main chamber if
needed. This may affect your side walls, but I cannot say to how much
of a degree. You may get away with two passes through your etch
chamber without breaking down the resist.
Aside from that, I would really push for cupric etching if given the
chance.
Good luck,
Sean
Eric Masters wrote:
> I am having some difficulty with dryfilm breakdown on heavy copper
> etching.
> I have tried a number of different films, and they all work on copper
> weights
> less than 3 ounces. Above three ounces, I begin to have breakdown
> issues in
> the etch replenisher chamber.
>
> I have maximized all the process parameters for dryfilm: surface
> prep,
> lamination exit temperature, exposure, and developing. I am convinced
> that
> the problem lies with the etching chemistry, but I'm not sure what
> parameter
> contributes most to breakdown.
>
> Does anyone know which component is the most troublesome? or is it a
> combination of things? I've tried varying pH, copper concentration,
> chlorides, and controlling free ammonia in the replenishment chamber.
> Any
> suggestions will be appreciated.
>
> Thanks.
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