DIY PCB How To Create Your Own Printed Circuit Boards · A CNC mill is a machine that mills off the unwanted copper of your board When I went to the University of Oslo we had access to a CNC mill It was great to be able to mill a PCB but placing vias manually is a real pain in the butt if you have a lot of them CNC mills can be very expensive but I have also seen many DIY projects where people build their own mills Like this guy Fab house