Homebrew PCBs

>From: Markus Zingg <m.zingg@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: Re: [Homebrew_PCBs] Narrowest tracks?
>Date: Mon, 26 May 2003 15:45:18 +0200
>
> >I'm quite sure I could get 8 mils, with a better printer, as I can get 12
> >reliably even with tracing paper.
>
>Of course, it works for me also.
>
> >I think a lot of people have problems because they have the artwork/PCB 
>too
> >close to the UV source. The exposure might be nice and short but the
> >definition and contrast are often poor. Someone I know just can't get 
>good
> >results. He's joked about coming over to the UK (from the US) to see how 
>I
> >do it.
>
>Hmmm, I have a picture online of my exposing unit which is a Scanner
>housing with UV tubes built in. The picture showes the opened unit and
>there you can see that the tubes are relatively close too....

Similar to mine, except you have *lots* more tubes and mine is made 
(crudely) from MDF. 8-)

My tubes (I only have 2) are about 13.5 cms from the glass and about 10 cms 
apart. Exposure is 13 minutes. I keep meaning to add a third tube in the 
middle and use curved reflectors and a sort of grid for collimation.

Leon
--
Leon Heller, G1HSM Tel: +44 1424 423947
Email:leon_heller@...
My web page: http://www.geocities.com/leon_heller

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