What is Castellated holes / half-holes?

Castellated holes is PTH holes or via that are cut through to create a partial or half holes to form an opening into the side of the hole barrel.

Generally, it is used for mounting a PCB to another one.

How to make castellated holes in your design?

Please make sure a via or plated hole is added directly on the outline of the boards where the plated half hole is required.

Ensure that half of the via is on the board and half is on the outside of the outline. 

BTW the following rules should be followed:

- Copper layers (GTL and GBL): Copper pads on both top and bottom copper layers for each castellated hole.

- Solder mask layers (GTS and GBS): Solder mask openings on both sides.

- Drill layer (TXT/DRL): A drill hole for each castellated hole.

- Mechanical/Outline layer (GML/GKO): The outline should cross the drill hole.

Notes:

1. If "Yes" is checked, the castellated holes will be made with a special process and extra cost will be charged.

2. If "No" is checked, the castellated holes will still be made but with the ordinary process, so the quality is not promised (e.g. defects may highly occur: unplated holes, incomplete plating, hole with copper residues etc.).

3, To make Castellated holes, the hole size and space need to be 0.6 mm at least.