I don't think there is a standard for that.
I'm pretty sure they are allowed to overlap.
- but -
We don't want them to overlap too often, because it "swiss cheeses" the planes,
and return currents have to go around slots created by "ganged clearances"
Jack
On Wed, 10 Feb 2016 17:43:16 +0000, Victor Hernandez <[log in to unmask]> wrote:
>Fellow TechNetters:
>
> I am unable to find/locate a spacing dimension between the two antipad/clearance rings for class 3..
>
>Victor,