Zecal Engineering wrote:
>
> We have trouble with dry film lifting during heavy dep gold plating. LPI works, but is difficult to strip. Any suggestions?
>
>     ---------------------------------------------------------------
> We have trouble with dry film lifting during heavy dep gold plating.
> LPI works, but is difficult to strip. Any suggestions?There are several options you can employ to enhance adhesion of the film.
The first thing to understand is that deep gold plating is inefficient. Inefficient
plating processes tend to gas during the plating process. Gassing causes bubbles which
can cause a "scrubbing" action on the film and cause lifting. Therefore:

1.      Minimize the gassing by maintaining the gold concentration in solution near the
upper range.
2.      Keep the solution moving past the cathode so that the gas bubbles keep moving and
this will help keep OH ions from attacking the resist. The ions are a by product of the
plating reaction.
3.      Lower the cathode current density in order to minimize the inefficiency.
4.      Pay very close attention to the surface prep process prior to dry film
lamination. At this point, one needs all the help oine can get.

Good luck.

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