The plotter I worked on at Dickson in 1969 did use a
laser in addition to the aperature wheel. The laser
was fixed in position and the beam was positioned by
mirrors on the X/Y drive.
The high resoluion boards being made by commercial
fabs today are still done photographicly. The
photographic process has higher reseolution than can
be generatred by our common printers.
The semiconductor industry uses the same photo
techniques to make masks which are shrunk
photographicly. And the use an etching process similar
to the way PCBs are made but in far higher resolution.
My interest is not in making PCB as good as commercial
houses make. Just good enough for hobby level projects
and possibly some very low volume production. Foe any
real production these processes are just not cost
effective.
Bob Macklin
Seattle, Wa.
--- DJ Delorie <
dj@...> wrote:
>
> Answering from the perspective of "Home Brew
> PCBs"...
>
> Bob Macklin <rottenrobbie0@...> writes:
> > Do you know what a GERBER machine is? It is used
> to make a photo
> > mask.
>
> Yes, I know what a gerber file is, and what a
> commercial photoplotter
> is. I wrote a gerber viewer for Data General in
> 1988 (where I
> designed PC motherboards), and the current gerber
> plugin for gEDA's
> PCB program.
>
> > The GERBER is a laser photo plotter.
>
> "The gerber" these days is a text file with
> photoplotter commands,
> with syntax conforming with the RS274D or (more
> recently) RS274X
> standards. It was originally designed for a
> mechanical photoplotter
> with an aperture wheel, not a laser photoplotter.
>
> > I worked on the original at Dickson Eletronics in
> Scottsdale in
> > 1969.
>
> And did you do better than 6/6 rules at home back
> then? If so, how?
> That's what I'm interested in. As I said, I know
> commercial fabs can
> do better, but how can we?
>
>
> Be sure to visit the group home and check for new
> Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
> mailto:Homebrew_PCBs-fullfeatured@yahoogroups.com
>
>
>