Homebrew PCBs

--- 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