Problem with two colliders!

Unity Engine
1

Hi everybody!!!
I’m creating billiard game! All my balls have y-freeze position. And I have a problem:
sometimes when new ball created in place where another ball located, they enter to each other. How I can fix it?

2

What coincident, me too! Try this:
http://docs.unity3d.com/ScriptReference/Physics.CheckSphere.html

3

It’s nice.
THX for detection!
But I want to split them. How can I do this?