Homebrew PCBs

On Tue, 11 Apr 2006 20:59:34 +0200, Ronald Vanschoren  
<yahoogroups@...> wrote:

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> Anyways, I'm just slightly depressed now, so I need some icecream
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> Thanks in advance for suggestions and greetings,
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> Ronald
>


I didn't know conrad had a french operation... long time since i bought  
there..


Anyway, about your board. I suggest the following:
Get a stip of photoboard, pull the protective foil off, and a sheet of  
black paper or cardboard or thin sheetmetal or.. (anything that is REALLY  
not letting through light.)

Now put the this cardboard on the light table, and the PCB on top of it.  
You want to expose only a small part of the PCB at first. After a while  
pull the cardboard back some more to expose a larger area. Time this and  
write down the times (you can mark the back of the PCB). You want like 10%  
to 1000% of the recommended time in coarse steps. Then develop that making  
sure you have the right concentration of developer.

This excludes any transparency problems, and shows you the ideal exposure  
time. Work from there with the transparency and you'll get there.

ST