Hello ghidera2000,
01. January 2003, 20:29:37, you wrote:
ggyc> would qualify as a UV source - it doesn't (silly me :D) Exposed for
ggyc> 60 seconds and tossed it into the developer. Sat there for two
ggyc> minutes with zero effect. I rinsed it off and re-exposed for 6
ggyc> minutes (board is gone, may as well experiment). Developed in like 1
ggyc> minute and it was PERFECT. Couldn't believe it. I expected to see a
ggyc> ghost of the first exposure but there was none at all.
And I replied:
There are a lot of info on PCB making. I've made the axposure unit using 2
Philips TL20/09N 20W tubes that are quite radiating in the UV spectrum.
Peek output is somwhere arround 340-360nm range. the /09 type of tubes
have more UV radiated than /05 type. The tubes are rised approx 20cm from
the board covered with the artwork, and the exposure time that I use is 5
minutes, determined with stouffer gauge, and each of the boards that I've
made came out perfectly. (artwork - graphical film made in the printing
shop covered with ordinary 2mm glass).
interesting links:
www.thinktink.com
www.stouffer.net
--
Best Regards,
Zoran
mailto:
zasto@...