[sdiy] etching really fine tracks on a pcb

[Tim Parkhurst]

On 8/16/07, Heiko van der Linden <heiko.vanderlinden at tudelft.nl> wrote:
>
> I am currently trying to make a small pcb for a PSOC with very fine tracks.
> I do
> the lithography and ethcing myself. The lithography is done with a
> commercial
> exposure box and looks very sharp. But after etching with ammonium
> persulphate I
> see that fine tracks near the edge of the board are thin compared to similar
> width
> tracks near the middle of the board.

A bubble etcher? Basically a tank filled with etchant, a heater, and a
fish tank aerator (a small pump that blows bubbles in the tank to keep
the etchant moving). This is similar to the setup used by board
houses, so it may yield more consistent results. Otherwise, I'd just
start with a bigger PCB and trim off of excess.

Please put some photos up if you have them. I'm sure a lot of people
here would like to see your boards.


Tim (also a small bubble blower) Servo
-- 
"Imagination is more important than knowledge." - Albert Einstein