Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "Alan King" <alan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Wednesday, January 07, 2004 8:37 PM
Subject: Re: [Homebrew_PCBs] late night office experiment


>
> Yes you still have to get the toner up above the melt point, so
> really shouldn't be much difference.
>
> What really would make a difference is to have no sheet in between at
> all. As in a direct laser print to the board. I have looked at the
> idea, an insulation layer over the copper is all that's really needed,
> so it'll hold the electrostatic image. Something that can be etched,
> but that won't etch out too fast under the toner, or that the toner will
> melt through some in fusing with pressure but won't just melt off onto
> the fuser where there isn't toner. Plus it takes a straight through
> printer and mods for the board thickness, but that's minor enough. Also
> you have to be sure your edges and surface is smooth with no scratches
> or you'll scratch the drum. Quite a bit of trouble to get it going when
> the results from just ironing on are so good..

I worked for Rank-Xerox UK many years ago.

Xerox's first copier was a manually operated 'flat bed' copier, with a
photoreceptor plate. The plate
was charged, then exposed to the image. The image on the plate was then
developed
by cascading developer and toner over it, the toner image on the plate was
then transferred
onto paper and passed through a fuser (a simple radiant heater).

Even when automatic copiers like the 914 and 813 were developed the flat bed
machines were still popular for certain jobs, like making prototype PCBs.
Instead of transferring the toner image onto paper, the image on the plate
was transferred directly to the copper surface of a PCB. It was then passed
through the fuser and then etched. I saw some PCBs made using this technique
and they were quite good by the standards at the time. I kept meaning to try
it for myself, but never got round to it.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html