I know what you mean, i have the same problem, but not because of the
etching.
The toner seems to break from the board easily before i can remove the
paper on the outside traces or the board outline.
So now, if i don't make a ground plane anyway, i will have a second, wider
outline surrounding the board to protect it.
This will often be partially over the board edge but that doesn't matter
since it is cut off anyway.
ST
On Mon, 13 Feb 2006 20:58:16 +0100, dl5012 <dl5012@...> wrote:
> 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