> > Hello!
> >
> > I am following this nice group for a while. This is my first post.
> >
> > I've got old X/Y coordinate table which used to be simple pick and
> > place machine. There's no Z axis and mechanics is not strong enough
> > for holding any machine with drill or mill tools. One crazy idea
> > crossed my mind... what if I put one UV light source to
> this machine
> > and plot with UV light directly to photoresist coated FR4?
> I can make
> > small optical mask with (e.g.) 10 mils aperture, which
> floats on thin
> > air blowing beneath the mask. It could act as single
> (fixed) aperture
> > photoplotter for direct exposure of PCB photoresist.... Is
> this kind of stupid idea?
> > Anyone had experience with that? Would be UV LED enough? Exposure
> > time is critical here, but I am talking about PCB prototyping.
>
> The field of homebreweing PCBs is full of nutty ideas, some
> of which work.
> I'd call this nutty, but definitely not stupid. It's worth
> some investigation to see if it's feasable.
It's already been done. Works well actually, definitely not nutty.
There's a web page out there somewhere of one that was home made, but there
are commercial versions. If I recall he attached the film to a cylinder
(which rotated) and the laser was moved across it. Like a lathe works.
Years ago (like 1990) I worked for a company that did bar code stuff. One
thing we did was film masters & bromides for bar codes. These were sent to
the printers who used them to print the product packaging.
The machine was an X-Y plotter with a laser, drew the images on a piece of
film which you then developed. Very nice sharp lines, very accurate too.
Downsides are it's a bit slow compared to a printer, and you need to have a
darkroom.
Controlled by a BBC micro, of all things!
Tony