Hi!
I think this is what you're looking for:
https://jlcpcb.com//quote/pcbOrderFaq/Castellated%20holes

When you go to order the PCB's, there is an option called "Castellated holes", check yes and there you can set how many sides will need the plating.

Hope this gives you more insight. :)

quote from here :
https://jlcpcb.com//quote/pcbOrderFaq/Castellated%20holes
.......PTH holes or via that are cut through to create a partial or half holes....

I need to know
That exactly half of the PTH is a strict requirement?
or I can choose any segment less than 1/2 of the hole - this is 1/3, 1/4, 1/8 and etc -  the technical control will allow the board to be manufactured

@serg28,

You should probably change the category of this topic to JLCPCB.

:)

OK, changed  )

@serg28   Yes ,That exactly half of the PTH is a strict requirement ,because we must ensure the standard process  ; We only support 1/2 of the hole ,otherwise it's out of our technical control .