| 摘要 |
<p>This invention relates to a device for simultaneously centering a plurality of substrates, particularly semiconductor wafers W. A plurality of turntables 23 for supporting the semiconductor wafers W are arranged at a predetermined spacing in the vertical direction. All of the turntables 23 are driven by a single, common servo motor 28. Clutches 26 for each of the turntables 23 are disposed on rotational shafts 38a and 38b that are driven by the servo motor 28. A drive pulley 41 is attached to an output side of each clutch 26 and each drive pulley 41 drives the corresponding turntable 23 via a belt. A sensor device 29 for detecting a notch formed in the peripheral edge of each semiconductor wafer W is disposed on an outer side in the radial direction of each of the turntables 23. A wafer W is placed on each of the turntables 23 and is centered. The servo motor 28 operates in a state in which the clutches 26 are connected, so that all of the turntables 23 start to rotate simultaneously. As a CPU 30 receives notch detection signals from each of the sensor devices 29, it sequentially disengages the clutches 26 corresponding to those turntables 23. This invention makes it possible to simplify the structure of the device and make it more compact.</p> |
