Silicon Technology Corporation

Thomas Lewandowski

Robert E Steere, Iii

Robert E Steere

The edge profile machine employs a centering station in which a photosensor measures a number of points on the periphery of a wafer so that the shape of the wafer and location of the geometric center can be determined in a computer. A rotatable head serves to position the geometric center of the wafer on a fixed axis and the wafer transferred to a grinding station with the geometric center located on the central axis of a rotating chuck. During grinding, a grinding wheel is moved in accordance with the differences between the detected shape of the wafer and a predetermined shape. The grinding wheel is moved on an axis perpendicular to an axis passing through the centering station and grinding station in accordance with signals received from the computer.

Automatic edge grinder

The saw assembly is provided with a self-contained balancing means for the automatic balancing of the wheel head. In one embodiment, the balancing means includes an annular rotor which is mounted on the wheel head and which contains a vaporizable fluid medium within circumferentially spaced chambers. Heating elements are provided for heating selected chambers in order to vaporize and transfer the balancing medium between chambers via a capillary manifold tube, or pneumatic means is used to transfer the balancing medium. Sensors are provided to sense the rotation of the wheel head and the radial vibration of the wheel head and cutting blade of the saw assembly in order to determine where the wheel head is out-of-balance.

Growing community of inventors

Wanaque, NJ, United States of America

Thomas Lewandowski