| 摘要 |
PURPOSE:To make it possible to set a wafer in a desired position by a method wherein one point between rotatable rollers is movably supported and pushing force is given to the supporting point for the rollers to be pressed against a wafer. CONSTITUTION:A wafer 4 being pneumatically supported above a wafer supporting plate 23 is moved toward driving rollers 2, 5, 6 and a rotating roller 3 by see-saw type pushing rollers 15-18 and is then rotated. At the moment when one end of an orientation flat 4' reaches the roller 15, the pushing component force exerts a moment against the wafer, which moment affecting in a reverse direction of the rotation is, however, small. On the other hand, the effective force required for moving the wafer 4 toward the roller 2 is great and hence a minimum value of the friction coefficient between the wafer 4 and the roller 2 is decreased. Just when the flat 4' contacts with each of the driving rollers 2, 5, 6, among which the two rollers 5 and 6 are returned to a state of free rotation in response to a signal transmitted from a device for optically detecting the flat 4' thereby to prevent any overrun given by the inertia of rotation. |
