Re:milling pc boards

Subtopic: EAGLE Layout Editor

Andrew Werby wrote
[but is it as hard
to learn as it looks? And what do they mean by "copper pouring"? ]

Eagle does take a bit of getting used to, but isn't really
any harder to learn than the Ivex or Protel programs that I've used.
It seems to have the look and feel of a program written for a Unix type OS,
so it may be a little 'non-intuitive' at first if you are used
to win9x(it makes use of the middle mouse button for example) but once you
get into it you shouldn't have to much trouble.
Copper pours or zones 'I think' are just areas where the copper is
not removed To save etching time/chemicals,give some EM shielding, or
extend a ground plane

[Does the mill_drill utility track the traces, or the space between the
traces? For doing what you're talking about, the former would be fine, but
to mill the board with a cutter, the latter would be necessary. Is this
method supported?]

the mill and mill_drill scripts are eagle user language programs that
add extra features to the base program (C like syntax,well comented)
they produce a toolpath that outlines the traces and pads to separate
them from each other, just what you wanted:)
when I use a pen in the spindle to draw the traces I use the normal output mode.
there is also a ulp to convert your board to dxf format and in the
powertools package is a utility to convert dxf to board

subtopic: conductive ink & plating

[I'd heard about the Sharpies for acid resist, but what pens are
conductive? ]

I've seen these in some catalogs for repairing broken traces on boards
Or fixing rear window defrosters.


The chemicals needed for building up copper with electricity
aren't as nasty as the ones that dissolve it, so even if the dip method
didn't work this might be viable if one invested in a small electroforming
setup, like the ones sold by Dalmar. These can also be used in reverse for
electro-etching, which might make the conventional appoach less toxic.]


Jon Elson wrote
[This won't work very well. The electroless tin is very 'fuzzy', ie. low density.
Also, it burns away very quickly at soldering iron temperature. I've never
found it to be usable at all. Also, the electroless tin is as likely to deposit
on the fiberglass as on the conductive ink. It has some sort of reaction on
copper, but won't deposit on a lot of other surfaces.

Jon]

Oh well,I didn't really expect the dip tin to work that great,
copper would be better of course but that goes right back to
all the wet electro-chemical stuff that I had hoped to avoid.
My idea was to take a net shape part (not flat, say a fiberglass
shell for a small robot) and incorporate most of the electronics
Into its surface, sure it would be a design/build/debug nightmare,
but that's when you really start learning stuff

Brian