SMD pads with holes

[tdarlic]

Hi

I am creating a pcb with a zentri Bluetooth module. The module has a row of ground SMD pads with holes:

I’ve created the footprint as per the images below. For the ground pads i just created trough hole oval pads and offset the holes to the top.
The specifications ask for “key like” pads which are thicker around the holes as on the image above.
Any idea how to “ellegantly” create this in KiCad?

[Joan_Sparky]

@tdarlic

Any idea how to “ellegantly” create this in KiCad?

Just use oval smd pads like the others and then create a row of PTH that are partly overlapping.

PS: are you aware that those are castellations? I would make that more clear in the footprint and mark out the board edge on a different layer than F.SilkS

Question about castellation

@Nilz Are those mounting holes for the display? Can you make sure that nothing will be able to get hold of the bolt-heads or nuts/thread behind the board and try yo pry them out (as I’m sure the display has not much ‘flesh’ around the hole and will be the only thing keeping the bolt “straight”? I wouldn’t worry about the castellation too much, just get a bit more more copper on the top/bottom surface there (make the pads larger) to counter the forces when it’s being routed, as the chance of i…

Also, if you need those to come out perfect then you might also want to talk with your fab house about their ability in regards to those.

[davidsrsb]

Are the holes used by the module itself? It would be much easier if the hole could be placed in a zig-zag pattern, allowing better clearances and bigger pads

[tdarlic]

Thanks Joan for fast reply. Yeah, I know that these are castellations. Will have to speak to fab house before sending these to them. I will definitely mark these separately. This is a first time I make these in KiCad so I was wondering is there something I missed.

For the PTH I understand that there are no way to include them in the footprint so i need to add them after placing the component on the board?

[tdarlic]

No, the holes are castellations so the intention is for the holes to be cut in half during milling of the board. I’m pretty sure that they need to be in this straight line as shown on the drawing…

[Joan_Sparky]

@tdarlic

For the PTH I understand that there are no way to include them in the footprint so i need to add them after placing the component on the board?

Sure is, as I said, partly overlap a SMD pad with a PTH.
Something like this:

Just make sure the pin numbers match for each of them… otherwise DRC will try to kill you.

[davidsrsb]

Ok they are castellations, then do they need to be plated through pads? Or is the aim to make finger contacts to the board edge? Any particular reason for castellations rather than routing?
This is definitely one to discuss with the pcb house

[tdarlic]

Thanks for advice, i did it like this. Looks exactly as it needs to be…

[tdarlic]

It’s a Zentry BT module (see link below) which I am installing onto a board and I usually tend to follow the datasheet specification as much as I can.
https://zentri.ack.me/products/AMS002_Bobcat_LC