Homebrew PCBs

Have you tried masking it with something really opaque, like sheetmetal or  
something?
Sorry if you have already done that, i don't quite remember all posts.
It would show if some transparency is the problem.

ST

On Thu, 13 Apr 2006 21:42:46 +0200, patroclus04 <patroclus04@...>  
wrote:

> Hello,
>
> I made another PCB, this time more complex, and tried to solve the
>
> problems I had, especially the photo-resist coming out when tried to
>
> clean the board's surface while developing.
>
> I was not able to solve this...
>
>
> I'm thinking that may happend because of some light getting trough the
>
> dark areas in the transparency, so expossing a bit, and so making
>
> photo-resist come out when I try to clean the board while developing...
>
> If I take out the board and clean with lots of fresh water, then it
>
> does not come out anymore.
>
>
> Now the question... I don't know how to solve this. Maybe:
>
>
> - Less expossure time (the problem is I need 0.3mm track separation
>
> sometimes, so it's tricky, as little time doesn't allow to separate  
> them).
>
> - Use acetate paper and laser printer (I was using inkjet paper,
>
> printing in the rough side with a inkjet printer. Should this be a
>
> problem??)
>
> - Take the board out of the developer sooner. When the image appears,
>
> I usually left the board in for about 1 or 1,5 minutes.
>
>
> Do you think this could be right?
>
> Any advice?
>
>
> thank you!