On 5/27/2015 7:29 AM, gareth wrote:
I wonder if anyone here has experience of milling PCBs using
CNC rather than etching them, and if so, what pitfalls and pratfalls
were encountered?

Years ago a place I worked had one of the machines that cost a few
thousand. It wasn't great as they hadn't provided a good base so the
board could be inserted multiple times with the same registration or
easily flipped for double sided. The bits were conical rather than flat
tipped and tended to break easily. In the end the company went belly up
and we were stuck with proprietary software that was no longer
maintained. The only people who really used it much were the RF guys...


Some in s.e.d use a mounting technique of soldering bits of double sided
PCB onto a board of copper clad as soldering islands. No etching
needed. Not the greatest appearance, but it is very fast and simple to
make and you do have a decent ground plane even if you don't have good
impedance controlled runs... maybe. I expect you could find a wire with
the appropriate thickness insulation for a given impedance and glue it
to the copper clad. Think microstrip.

--

Rick