Hi Eric,
believe it or not I had the same problem and I
solved it only by closing any fume extraction after the etching and replenish chamber.
I suppose the dry film was brake down from ammoniac
fume that from the etch and replenish chamber was aspirate into the rinsing
chamber.
Moreover, as first step I only had replenish
directly in the etching chamber.
Good luck
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.