On Sun, 22 Apr 2007 14:00:30 +0200, Russell Shaw <
rjshaw@...>
wrote:
> Bubble and foam etchers are a very gentle agitation and etch everything
> off in most cases. Many times however, traces of copper are left because
> of stubborn resist caused by variations in pcb cleaning, coating, and age
> of chemicals used.
> A spray etcher with proper nozzles has a ∗very∗ hard fluid impact
> compared
> to bubble etchers and really knocks off the last few percent of stubborn
> cases.
Maybe including the resist we want, considering many of us use
less-than-industrial-strength resist.
ST