G'day Jason,
My understanding of it is that you need to have collimated light, i.e. all
light rays are coming vertical to the artwork so that it does not go under
the edges of the artwork.
This is the reason that a negative should be placed with the emulsion on the
PCB to reduce any chances of the light going under the edges.
I saw somewhere where they used an egg-crate diffuser (from a flourescent
light fitting) painted matt black, to collimate the light. This meant a
reduction in effective light output but a cleaner image.
Cheers
Brian
-------Original Message-------
From:
Homebrew_PCBs@yahoogroups.comDate: 01/24/05 12:20:04
To:
Homebrew_PCBs@yahoogroups.comSubject: Re: [Homebrew_PCBs] UV lamps?
At work, for exposing printing plates we have a professional vacuum UV
exposure table. This uses a few dozen bulbs very close to the work.
Isn't this the ideal situation for PCB too?
Earl T. Hackett, Jr. wrote:
> I'd recommend a single bulb fixture - the smallest you can get a lamp for
- and
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