gEDA-user: DIY brass stencils

DJ Delorie dj at delorie.com
Wed Feb 21 19:32:36 EST 2007


> You have to control the access of the etchant to the metal.  Maybe a
> dithered fuzz of toner around the edge of the hole would allow the
> center more access to etchant so you could go through before
> exposing as much edge.  Eventually the isolated dots would just fall
> off as the surrounding metal was eaten away.

The pitting indicates that any tiny hole, no matter how fine my
dithering, results in a cone shaped pit.  Think about it - if the
etchant can get to the other side, which is 5 mils away, it can
certainly get sideways the same amount through the same hole.
Since the holes I'm trying to make are only 10 mils across, 

> I'm wondering if you use a scalloped hole like that, if the "bowl"
> of solder paste will actually be peeled off by the lip all around
> the edge.  You almost need to etch it from the board side so that
> the opening "faces" downward.

The idea was always to have the "toner" side down, so that it releases
the paste easier.


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