Homebrew PCBs

The pc house that I wourked at for a while did tin plate before
etching and then use and ammonia based ecthant.  The process is to
drill, plate the thru holes, tin plate the pattern and then etch.

I tried using a plated piece of pcb material that I silk printed a
pattern on with fecl and it etched through.  

Russ



--- In Homebrew_PCBs@yahoogroups.com, "Jan Kok" <jan.kok.5y@...> wrote:
>
> On 3/27/06, aggie_672000 <aggie_672000@...> wrote:
> > It is my understanding you tin plate the pcb after etching to
> > protect the new copper trace from corrosion. TINNIT is the name of
> > the material used to tin plate.
> 
> That's all true.  But I know I read the same thing that Matt did
> (where did you see it, Matt?), that some commercial processes use tin
> plate as an etch mask.  I don't remember why they did that.
> 
> Seems one could do that as a homebrew process:
> 1. Put toner or leave photoresist where you want to etch
> 2. Tin plate the areas you want to keep (TINNIT)
> 3. Remove the toner or photoresist
> 4. Etch
> 
> but I don't see what advantage that would have over the more common
> homebrew processes.
> 
> Cheers,
> - Jan
> 
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
> > <stefan_trethan@> wrote:
> > >
> > > On Mon, 27 Mar 2006 17:50:06 +0200, matt clement
> > <buckeyes1997@>
> > > wrote:
> > >
> > > > I saw a process used by a fab house and they used a negative
> > photo
> > > >
> > > > resist and then tin coated the board.  The tin only stuck to the
> > > >
> > > > places that had the bare copper.  Then the board was chemically
> > etched
> > > >
> > > > and the tin protects the copper.  Would we possibly be able to
> > come up
> > > >
> > > > with a similar system of printing a negative image and then tin
> > > >
> > > > plating before etching?  The toner would probably melt when you
> > tried
> > > >
> > > > to tin the board with an iron, but maybe a chemical plating
> > process?
> > > >
> > > >
> > > > Does anyone know for sure if tin etches away with FeCl?  I might
> > have
> > > >
> > > > to try it at lunch...haha.
> > > >
> > > >
> > > > matt
> > > >
> > >
> > >
> > > I'm not sure about FeCl, those tin resist baths are usually
> > Sulphuric acid
> > > / peroxyde i think.
> > > You could do things that way, but why do you want to?
> > >
> > > ST
>