Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

Hi Larry,

Thanks you for your effort and offer.

A while ago I was doing artwork testing for best resolution and print
density and I had a post with resolution targets. I never got finished,
work is interfering with my hobbies...

What artwork material and printer/ink are you using and what is your
practical trace size?

Bertho

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From Larry Battraw Sent: Monday, December 19, 2011 07:44
Hi Mike,

Not sure what you mean by rigorous testing. I've done a fair amount of
tests to zero in the best exposure time for the combination of lights,
distance, and artwork I use. I'm not sure it would be very useful to
anyone else since I built my own setup and it will likely vary depending on
your light source and artwork medium. I use two 40W U-shaped UV "bug
lights" from Home Depot, mounted side by side at 8 inches from my board.
It takes about 4.5 minutes to get a good exposure. It's not really ideal
since the lights are fairly narrow (I really would like to have 4 of them
but haven't got around to it) but it works for my purposes. I affix my
inkjet-printed red (Black prints out poorly on my transparencies) artwork
to the board in those vacuum kitchen sealer bags to get a very tight
interface since I don't have the room for a full-sized vacuum bed.
Regards,
Larry





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