A few people here did some tests with toner transfer to determine if 300dpi or 600dpi Laser printer resolution was sufficient.
The end result was that 600dpi was required.
So to make a board 2x3 inches, you'll need 2x3x600 = 30,000 LEDs. And they'll need to be about a thousandth of an inch square in size.
Steve Greenfield AE7HD
--- In Homebrew_PCBs@yahoogroups.com, Benjamin Blumer <b3nzilla@...> wrote:
>
> I like the idea of an area of LEDs. I wonder what kind of resolution /
> LEDs/inch one could get.
>
> Sent from my iPad
>
> On 2012-06-29, at 8:30 AM, designer_craig <cs6061@...> wrote:
>
>
>
> Janes,
> The UV laser has been done -- check back in the archives Zoltan built a
> system basically replacing the print head with a UV laser diode and raster
> scanning the board. It was a little slow but had stunning resolution and
> chrispness in the image. It's on my project list, just not near the top.
>
> Craig
>
> --- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@> wrote:
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@> wrote:
> > >
> > >
> > > Is it time for someone to purpose-design a direct-to-pcb printer?
> > > Probably way too expensive to consider, but still...
> > >
> > > Maybe something that laminates UV film on, and has a linear array of
> > > high power UV LEDs to expose the film as it's being laminated, on both
> > > sides... Include an infeed tray with registration pins for pre-drilled
> > > PCBs... pre-drill, drop on pins, press button, when pcb comes out the
> > > other side you wait 15 minutes, peel off the outer protective film, and
> > > develop. Maybe it could laminate (or just use a sticky-backed film) on
> > > a UV-opaque film over the UV film after exposure, so you don't even need
> > > a darkroom :-) Add a tiny inkjet head on the way out to print timestamp
> > > and job information, and you're done!
> > >
> > > ok, blue-skying over :-)
> > >
> >
> > I suspect it will be difficult to come up with something that will be
> affordable yet offer decent performance.
> >
> > I'm intrigued at the thought of a laser photoplotter that would cure UV
> resist. Either an X-Y plotter table with a 405nm laser in place of a pen,
> or a scanner assembly from a laser printer with a feeder to run the board
> through.
> >
> > Really though I've got the laser printer toner transfer process pretty
> well dialed in, and for any time I want more than one board and don't mind
> waiting, Seeed Studio is ridiculously cheap so it's easier to just send off
> for a batch after I've etched a prototype at home.
> >
>
>
>
>
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>