Homebrew PCBs

At the edge of your board outside the final area place a small piece of aluminum foil.  That way you have a spot without any exposure at all.  Similarly cut a small notch in your artwork or have one side smaller than the PCB.  That way you get an area with 100% exposure without any loss through the  artwork.  Those two areas will work as a process reference and they have 100% contrast.  If they are good, then the issues are with the artwork.

Bertho

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] 
Sent: Friday, August 29, 2014 07:53
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] help request: disappointing etch resist development

 

  

On 29/08/2014 12:49, mattmoose1969@... [Homebrew_PCBs] wrote:
> Hi Leon,
>
> I'm laser printing the artwork onto 90gsm tracing paper, as recommended
> by someone who has done a lot more of this than I have.

It might not have enough contrast, try using LaserStar film. I think 
it's available from RS, or you can get it from Mega Electronics (UK).

Leon
-- 
Leon Heller