Homebrew PCBs

----- Original Message ----- 
From: "Harvey White" <madyn@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, July 04, 2008 2:09 PM
Subject: Re: [Homebrew_PCBs] double sided PCB, accuracy


> On Fri, 4 Jul 2008 09:47:55 +0100 (BST), you wrote:
>
> I've always had a conceptual problem doing it exactly this way.  I can
> see that if the joint between the two pieces of paper is exactly in
> the middle of the board thickness, every thing aligns.  If it's not,
> then one layer is offset with respect to the other.
>
> Has anyone considered aligning the masks with a filler made from a
> scrap piece of etched board, same thickness, and then perhaps a piece
> of plastic to duplicate the board?

That has been mentioned on this forum before, it's probably the best way to 
do it. A couple of pegs could be used with holes in the transparencies, to 
make the alignment even better. I think that something similar is used by 
the PCB manufacturers - they use dowels with their phototools.

Leon
--
Leon Heller
Amateur radio call-sign G1HSM
Yaesu FT-817ND and FT-857D transceivers
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller