Homebrew PCBs

Hi Stefan,

I posted a picture of the artwork for the largest board I've done 
with inkjet transparency TT.  It's 160mm x 100mm, I think most of 
the traces were 10 mils.  I had around 4-5 opens and had problems 
with the narrow traces near the edges of the board over etching; 
some disappeared completely.  I know my etching method is what 
caused the problem.  My container was barely large enough to hold 
the board and I couldn't agitate it in the ferric chloride very 
well.  That caused the traces near the edges of the board to be over 
etched.

I didn't author this artwork, and don't have an easy way to edit to 
make it easier to make.

Most of the opens were hairline breaks, so I used conductive silver 
ink (mentioned it before) to bridge them.  One was large enough that
a wire was needed.  The trace near the top of the board was mostly 
gone, so I used some adhesive copper to bridge (several inches).  
Fortunately it was ground, so now the board has a messy looking 
partial ground plane.

This is one reason that most of my boards have a ground plane around 
the perimeter.  I found that it protects the traces I care about.

I could have done a better job with that board, but I was in a 
hurry.  I thought I was going to send someone a loaner programmer 
and having something that worked was more important than having 
something that looked nice.  Life is full of trade-offs and 
sometimes seeking perfection isn't realistic...

The programmer works perfectly, but I never needed to loan it out.  
So now I have a constant reminder of that embarassing piece of 
work...

Regards,
Dennis

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
> That sounds like a lot of spreading - how small a 
trace/pad/spacing can  
> you get this way?
> 
> ST