the ball - grid array ball measuring system measures the distances between a reference plane and points on the surface of a small crown area of each of a plurality of balls within a ball - grid array . the points include the apex of each of the balls within the ball - grid array . these distances are then forwarded to the ball - grid array seating plane determining circuit . the ball - grid array seating plane determining circuit determines the ball - grid array seating plane in accordance with the jedec “ ball - grid array package ” standard . the determined ball - grid array seating plane consequently satisfies the needs for realizing calculations of dimensions and tolerances defined by the standard .