Annular Ring (OAR & IAR)
The Annular Ring value is defined as the amount of Copper from the edge of the Drilled Hole to the Copper Pad associated with the hole.
OAR – Outer Layer Annular Ring – for more information click here.
IAR – Inner Layer Annular Ring – for more information click here.
Also see our PCB Design Guidelines – Drilled Holes page.