High contrast (lithographic?) film

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puggie

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Bill
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I am looking at doing some prints at work for making RF circuit board, we currently use a system of printing on polyester film with a laser printer and UV exposing the circuit boards then etching. Problem is out printer is 300dpi I think so we can get down to about 0.3mm repeatably and accurately. we would like to get down to under 0.1mm resolution, so looking at making optical reductions of prints and using the negs to expose through.

I believe we would be looking at lithographic film, I just need solid images, no gray scales etc, all or nothing, clear film or blacked out. Anyone offer any advice? we are looking to photograph a print out from black on white paper print, reduce it by maybe 3 or 4:1 and 4"x5" negs would be ample.

anyone know anything about such a process?
 
I have only used lith film for artistic reasons but I would think you would get problems with optical distortion during the photographing and reducing parts of the process.

Wouldn't you be better of buying a 1200 dpi laser print for £160.
 
you know of a real 1200DPI laser so cheap? All the ones we have tried (mostly HP as they seem to have the blackest toner when washed in white spirit) give relatively rough edges and just not that sharp.
 
Most manufactures appear to make 1200 dpi printers now some are 1200 x 600 but the lots are 1200 x 1200 including dell the Dell 2230D and upwards are all 1200 x 1200. The dell is about £139 + VAT.
 
I've just checked and out HP is 1200X1200dpi and that is what we need to improve on by about 3X resolution minimum. I had assumed it was lower res from the print quality.
 
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I'm not sure you'll get an inkjet that is accurate enough as mosth use dither patterns I'm not sure the 1200dpi isn't just dithered possibly it won't be any finer for line tone. I know that lots of PCB and chip makers use lithograic materials apparently nothing else is as cost effective.
You need film like this one for the accuracy you require:
http://www.ultrafineonline.com/ulhicoorlifi.html
 
Inkjet wasn't giving us a dense enough print, that is why we used laser and washed the toner with white spirit to darken it.

That orto litho stuff looks JUST the ticket, any idea on a UK supplier or more info?
 
I used to work in the PCB industry. Photoplotting is what seemed to be most popular for RF stuff, (well - all PCB stuff ) from mobile phones to radar to microwave etc etc.

0.1mm easily done with most laser photoplotting machines.


My only experience with Lith printing, is that you still get greys. That was standard dark room neg printing onto Ilford (I think) Lith paper. I was very un impressed at how 'un' black and white it was !

Apparently, the good old fashioned stuff was better. But other than that I have not real experience of dark room lith.
 
Back in the "old" days if you wanted to produce negatives for PCB you were better off using "Line"film not lith. Line film had the advantage that it could be processed in a conventional developer, rather than a specialist one. Lith film needed it own type of developer other wise it gave a very poor results. Also the lith film and developer tended to accentuate artefacts such as "pin holes" caused by dust and similar, which meant you didn't get such a clean result .

Not sure if you can still get line film ( Both Ilford and Kodak made them) You could try Silverprint in London, but a quick check of their web site didn't yield anything
 
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