Homebrew PCBs

> A spray etcher is faster than most other methods, because it uses a 
lot
> of force/agitation. It is basically a set of nozzles spraying 
etchant
> at a board, and the nozzles move so it is distributed evenly.
> You get etch times around one minute or even less with it.
> 
> If you etch in a bowl the "used" etchant will sit close to the 
surface of
> the PCB, prolonging etch time. you will want to use some sort of 
agitation
> (like moving the board or bubbles) to speed it up. But even with a 
lot of
> agitation you don't get the speed of spray etching. (dunno why)
> 
> 
> ST


I think I read about surface tension of the etchant and exposure of 
the coppper being different if it was submerged and bubbled and 
sprayed.  IIRC, spraying acutally allowed the etchant to be removed 
down to the copper whereas the think film of etchant with bubbling 
never really did.

Dave