Homebrew PCBs

----- Original Message ----- 
From: "mikezcnc" <eemikez@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, January 20, 2004 7:01 AM
Subject: [Homebrew_PCBs] Re: UV light sources question


> Leon, how long does it take you to expose the PCB?

I have mine about 20 cm away from the PCB to get a sharper image, so I use
13 mins. It depends on the distance, of course. Over-exposure doesn't matter
so much as under-exposure. Test with some artwork and expose progressively
with a cardboard mask, moving it every minute, to get the correct exposure
time.


>
> Disco tubes (Black Light) are mentioned on the web all the time but I
> think they have the wrong wavelength for PCBs.

They will work, I think, but aren't as good as the proper ones.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html