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Test pattern for tuning UV

2014-04-14 by James

I rebuilt my UV box with 9 rows of 12 leds covering an A4 area, I had to 
use a diffuser in the end  otherwise because of the fairly wide spacing 
the led mounting was too critical to get a good even spread (even with 
the leds 15cm away from the artwork).

Anyway, I wanted to dial in the numbers a bit particularly because of 
the diffuser I was concerned that the resolution wouldn't be there 
(turns out, nothing to worry about, 8/8 seems just fine, I'm never going 
to want less than that).

I couldn't find a simple small test pattern in a usable (gerber) format, 
so I made my own, perhaps somebody might find it useful also one day.

Lines from 8 to 18mil, separations from 8 to 16mil, holes 0.8mm and 
1.1mm with 0.2mm, 0.35mm and 0.5mm rings, 1206,0806,0603 and 0402 pads, 
and a minimelf for no particular reason.

All repeated 5 times for a stepped exposure to home in on the right time 
(which turned out to be around 3m30s, but there is a massive amount of 
leeway, probably a minute either side is usable).

Anyway, here it is on github,  gerber and pdf

   https://github.com/sleemanj/pcb-test-pattern

you can use the Download Zip button on the right side of the page if you 
just want the files and not mess with git.

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