Abstract: The present invention proposes an apparatus for loading and unloading wafers to and from the semiconductor fabrication equipment. The present invention uses two U-shaped port plate supporters of high rigidity to respectively join with drive devices such as lead screws, shaft bearings, and a lead device, and then join with components such as a port plate, a port door, and a base. The assembly is driven by a motor via timing pulleys, timing belts, idle wheels, a pair of lead screws, shaft bearings, and a lead device. An encoder is matched for feedback control. Thereby, accurate positioning of the main mechanism of the wafer pod responsible for upward and downward movement can be achieved so as to increase the accuracy and reliability of positioning transfer of wafers. Secondarily, the contamination of particles resulted from the motion of the main mechanism can be reduced by using an intake filtering system.

Abstract: A two screw double-stroke and screw differential-motion mechanism is applied in a standard mechanical interface. The two mechanisms are utilized for the correlation of transmission between screws and nuts and the screw differential-motion, so as to achieve more efficient positioning and clamp retrieval and placement.