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Subject: Re: Exposing Photoresist and Some Boards I have built

From: "javaguy11111" <javaguy11111@...>
Date: 2008-02-22

--- In Homebrew_PCBs@yahoogroups.com, "jj_winkel" <jj.winkel@...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "javaguy11111"
> <javaguy11111@> wrote:
> >
> > I have updated my website demonstrating exposing and developing
> boards
> > using photoresist.
> > The url is
> http://www.pcbhobbyist.com/exposinganddevelopingphotoresist
>
> I am very impressed by your mask, has it really been printed with a
> R2400 ?
> I have a R1800 and pigment inks too, can you share printer settings
> and transparency details to achieve such a result ?
> Thanks
>

Yes, the mask was printed with an R2400. I am using eagle for my cad
software. I exported to a png, then loaded it into gimp and reversed
the image to make a negative and printed that out.

For the transparency I used Pictorico Premium OHP Transparency.

I am not sure of the differences between the R2400 and R1800 drivers,
so I am not sure if they will be applicable to the R1800.
Paper is premium photo glossy and best photo. Color management is set
to Advanced B&W Photo. There is an Ink Config option. Set that to +50
density and Drying Time per Print Head Pass to 50 which corresponds to
5 seconds. The black ink cartridge I am using is the Glossy Black and
not the Matte Black. Matte Black will not dry properly on the
transparency.

The settings I have are based on what is used for contact photographic
techniques. The photographers tend to work with plates made of
palladium and platinum and use UV light sources as well. So that
pretty much matches what we do, except we work with copper. We
actually have it easier because people doing photographic prints try
to get gray scale.

The other nice thing about the R2400 is that it also has a straight
through feed to allow items up to 1.3 mm thick to pass through. It is
not quite enough to use 1/16 board, but I did see some .04 board on
ebay that I could use to test direct to board printing. I might also
try direct to photoresist printing if the mylar will take the ink.

My initial tests while quite good, I think will be much better once I
have the UV LEDs. When those come in, I will mount some of the LEDs on
a breadboard to do some test exposures. The mask is well defined(but
jagged) down to .001 width and .001 spacing. I will be surprised if I
can etch that fine, but I am hoping to reach .003/.003 .

Damon