Patent ID: 7131211

Claim:
An apparatus for determining at least one dimensional value of a substantially planar substrate, comprising: a carrier configured for holding and positioning a substantially planar substrate in a plane, the substantially planar substrate having first and second substantially planar opposed surfaces parallel to the plane; a first linear measuring device including a first movable caliper finger disposed on one side of the plane for measuring a first linear distance from a common zero point location to the first surface of the substrate along an axis substantially normal to the first and second surfaces, the first movable caliper finger movable in a linear direction substantially normal to the plane; a second linear measuring device including a second movable caliper finger disposed on an opposing side of the plane for measuring a second linear distance from the common zero point location to the second surface of the substrate along the axis generally normal to the first and second surfaces, the second movable caliper finger being coaxial with the first movable caliper finger and movable in a linear direction substantially normal to the plane, the common zero point location being a location of an end of the first linear measuring device wherein the end of the first linear measuring device is in axial contact with an end of the second linear measuring device; and a calculation device for calculating the first and second linear distances.