Pads numeration when creating "combined" castellated holes on the edge

Hello, I’m trying to make "combined "castellated holes (for both THT and on-board soldering) like on Arduino Nano Every / Raspberry Pico boards.

I’m not sure, how to formulate the question, but I assume: “How to automatically link pin numbers between 2 pins?”

The way I’m making such a castellated hole (using KiCad 6.0.10) is:

  • make a normal THT round pad (80 mil OD, 40 mi ID)
  • add the rectangular THT pad with “castellation” checkmark (width 80 mil, length 0.1 inches, hole diameter 40 mil)
  • assign the same number to both pads
  • place the rectangular pad in a way when:
    • the board edge passes through its center
    • it overlaps with a circular pad
    • the distance between the centers of 2 pads is 50 mil
  • group these pads
  • copy-past group up to a final number of needed pads in the connector (let say, I need 30)

The problem starts when I need to re-enumerate those pins. If I’m using the built-in option “Renumber Pins”, I can easily re-enumerate the circular pads from 1 to 30, but how to restart it for rectangular ones? If I start “Renumber pins” and start clicking on rectangular pads, it also starts changing the number of circular pins (changing the previously created numbers). The way I see it, would be bounding the number of the rectangular pad to the number of circular pad it is in the group with, but I don’t get if such an option is in KiCad. Or what are other options?

P.S. Yes, I can do it all manually, but I was wondering if there is other option.

Nevermind, all that was needed is to use a rectangular pad with “NPTH, Mechanical” as pad type instead of “castellated”. Then KiCad doesn’t assign the number to it.

As far as I know, using pads with the same pad number is the way to go for “weird” pads.

When you use NPTH pads, I suspect you get into trouble later as these probably get flagged by DRC, or KiCad won’t even let you connect wires to (through) the NPTH. But I have not verified this.

A better way may be to add graphics to your pads. To do this, select a pad in your footprint in the footprint editor, then press [Ctrl + e] to get into “Pad Edit Mode”. In the pad edit mode you can add graphic objects such as lines, rectangles and circles to your pad.

With this, I was able to easily add the pads, but not drills for castellations.

You can of course use THT pads and attach graphics to that (But I think this only works on the top layer and this may be a bug) But then you still have only one hole. I’ve seen castelations with two holes (or is that a hole and a half?) And for that you need some workaround. KiCad does not support two holes in a single pad.