--- In
Homebrew_PCBs@yahoogroups.com, "Kim Vellore" <kimvellore@...>
Many thanks to all who replied with advice for double sided pcb
construction. I'll give it a go, it sounds as though that process
will work.
Steve GW4ZDU
wrote:
>
> I do a little bit of etching and registration is important for me.
The way I
> do it is I take both the printouts with traces an put a Plexiglass
the
> thickness of the PCB in between the printout once aligned under
light I put
> a tape on the top of the sheet that holds both the sheets together.
Now I
> open it up with the tape as a hinge. Replace the plexiglass with a
PCB,
> laminate and etch. Some of my work that involved etching are here
> http://kimsartshop.com/Bicycle.html
> http://kimsartshop.com/Motorcycle.html
> http://kimsartshop.com/CameraTrain.html
>
>
> ----- Original Message -----
> From: "Harvey White" <madyn@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Saturday, February 23, 2008 10:22 AM
> Subject: Re: [Homebrew_PCBs] Toner Transfer PCB Method
>
>
> > On Sat, 23 Feb 2008 09:51:05 -0000, you wrote:
> >
> > One method that is recommended by pulsar (who makes TT paper).
> >
> > 1) take the DS board and prepare one side. Toner transfer to it.
> > Registration is not a problem yet.
> >
> > 2) cut a piece of self adhesive shelf paper (Kmart: Martha
Stewart)
> > and fasten it to the unprocessed side.
> >
> > 3) etch the board as usual. You should get a one sided board with
> > bare (and protected) copper on the other side.
> >
> > 4) remove the backing, do not yet tin coat the board if you do
this.
> >
> > 5) at this point, I then drill a few well chosen holes in the
board,
> > and matching holes in the paper.
> >
> > 6) prepare the board and align the second side with the holes in
the
> > first.
> >
> > 7) run the board through the laminator again. You can use thin
paper
> > to protect the other side's toner
> >
> > 8) put a layer of contact paper (I use transparent so I can see
what's
> > happening) on the etched side.
> >
> > 9) etch the board if the registration is OK. I'd put in a
pattern to
> > make sure of that.
> >
> > 10) remove the backing, and the used toner. Tin plate as needed.
> >
> > 11) trim the board and drill as required.
> >
> > Comments:
> >
> > 1) this is a lot of steps
> >
> > 2) it's easier to align a pattern with the etched pattern on the
other
> > side of the board than otherwise.
> >
> > 3) less stress on the laminator
> >
> > 4) if you have a problem with both sides etching at different
rates,
> > this solves it.
> >
> > 5) you can strip the second side and reposition it if you must,
since
> > the first side is aligned by definition.
> >
> > 6) if something goes wrong on the first side, you have not wasted
more
> > etchant and toner transfer paper.
> >
> > Evaluation:
> >
> > seems to work so far, but I'm still getting the hang of it.
> >
> > Harvey