Re: gEDA-user: free technology printer

[Egil Kvaleberg <egil@kvaleberg.no>]

Mike Jarabek wrote:

>    Tek used to have a wax based technology called a `Phasar'.  The wax 
> itself seemed to resist my Ferric Cloride etchant, but I had great 
> dificulty in transferring the wax to the PCB.  I tried transferring it 
> from paper and transparencies, but could not control the temperature, 
> the wax went from solid to runny liquid very quickly, and tended to 
> smear the traces.  At the time, I had though that if I could somehow 
> feed the actual bare board through the printer I could image directly 
> onto the copper, and skip the whole transfer step. ( Unfortunatly the 
> printer belonged to my employer, and the paper path through the 
> printer had too many bends in it... And my raw PCB material was not 
> that flexible. :-)
The Phasers still exist, but are now sold as Xeroxes. They are somewhat 
expensive, and certainly nothing you would want to try to feed a rigid 
copper laminate through.

For making PCBs directly, the thing to use must be an old fashioned pen 
plotter, using a pen with a type of ink that is resistant to whatever 
you use for etchant. (There used to be special pens for that, but they 
are probably not fine-line enough).

These plotters usually support HPGL, which should not be difficult to 
convert from Gerber, for instance.

Low cost versions up to A3 used to be readily available, and I'm sure 
they will be sold on ebay etc. quite inexpensively nowadays.

Of course, laser prints on transparencies, exposed on photo-resistant 
PCBs, used to be the standard way of DIY PCBs. For sufficient contrast, 
and protection against hairline etch-troughs, one would normally place 
to identical transparencies on top of each other.

Egil