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