I assumed that they must have meant milling PCBs, because the only kind of “cnc-ish” way of manipulating things on wafers I can think of would be atomic manipul

I assumed that they must have meant milling PCBs, because the only kind of “cnc-ish” way of manipulating things on wafers I can think of would be atomic manipulation with a scanning tunnelling microscope, which really doesn’t seem likely!