Homebrew PCBs

----- Original Message ----- 
From: "LogicResearch" <logicresearch@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, April 04, 2006 8:22 AM
Subject: [Homebrew_PCBs] Making the PCB


> Ok,
>
> Now I have my chemicals and PCB etc, it's time to experiment with making 
> the
> boards.
>
> I'm using photo resist and developer etc - should I just experiment with
> times or does somebody have a good suggestion.

The development is easy, just make sure you have the right concentration and 
you can see when the resist has been removed - it turns purple in the 
solution. It only takes about 30 seconds or so for me with NaOH.

For the UV exposure you need to experiment. Best way is to use a technique 
like the test strip used in photography and make a test pattern. Put the 
pattern and PCB in the UV exposure unit and move a cardboard mask across 
every minute and see what exposure gives the best results. I use 13 minutes 
but I've only got two tubes and they are quite far from the glass.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller