I am making gerbers where I want one edge of the PCB to have castellations ( plated half-holes) on the edge.
What is the safest way to specify castellations in the gerbers that will ensure that:
- The fab how makes the castellations "properly", without making any mistakes. For example one possible mistake is that if the castellations are specified as vias chopped in half by the edge, then a CNC router cutting the board edge may tend to rip the copper off of the castellation through its high-speed spinning motion.
- The flat edge itself must be plated - not just the hole part!! See how the flat part of the edge is supposed to be plated in the vicinity of the hole: