Thanks, TWB. I was just wondering how long it took to add the additional 0.00007 inches of copper for the traces. I presume it is minutes to tens of minutes (and not hours because you probably can't afford that much time on the line) but I just don't know.
Donald.
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----- Original Message -----
> From: "twb8899" <twb8899@...>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Wednesday, July 13, 2011 9:55:16 AM
> Subject: [Homebrew_PCBs] Re: Plating rate
> I was in the PWB business for many years. Most jobs started with half
> ounce copper (.0007"). After drilling and electroless processing the
> panel was laminated with dry film photoresist, exposed, and then
> developed. At this point the only copper showing was the trace pattern
> which was then copper plated at 25 to 30 amps per square foot.
>
> After copper plating the panels were solder plated. The solder plating
> was also used as the etch resist. After stripping the dry film the
> panel had solder plated traces with a copper background that was only
> .0007" thick so the etching time was only a couple of minutes. That's
> the basic method of how it was done. Of course there was more
> processing after etching depending on the job requirements such as
> soldermask over bare copper etc.
>
> --- In Homebrew_PCBs@yahoogroups.com, Donald H Locker <dhlocker@...>
> wrote:
> >
> > I know that "real" circuit board houses don't etch away all the
> > copper they don't want, I believe they plate up where the copper is
> > desired over a very thin layer, then etch just a little copper away
> > from everywhere. Does anyone know how long it takes to lay down the
> > 1oz (0.0014in) of copper on a "real" circuit board in the panel
> > plating part of the process?
> >
> > Thanks,
> > Donald.
> > --
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