There are times that a PCB just needs a hole drilled through it. No plating or inner connections required. These are used for things like screw-mounting points. I have a case where a PCB design of mine is a daughter-board that mounts directly on top of another PCB board. But the lower board has some large electrolytic capacitors on it, so I need holes slightly larger than the diameter of the caps in the daughter board. I've been able to do this, by (1) making sure none of the inner planes cover these areas, and (2) putting a small via at the center of the hole to be drilled. The via serves as a place to center the drill bit. I then drill out a somewhat smaller hole in the area, and then finish with a Dremel tool. It would be far better if I could just have the board manufactured with the desired holes.
There are times that a PCB just needs a hole drilled through it. No plating or inner connections required. These are used for things like screw-mounting points. I have a case where a PCB design of mine is a daughter-board that mounts directly on top of another PCB board. But the lower board has some large electrolytic capacitors on it, so I need holes slightly larger than the diameter of the caps in the daughter board. I've been able to do this, by (1) making sure none of the inner planes cover these areas, and (2) putting a small via at the center of the hole to be drilled. The via serves as a place to center the drill bit. I then drill out a somewhat smaller hole in the area, and then finish with a Dremel tool. It would be far better if I could just have the board manufactured with the desired holes.