Manual wafer lift

Abstract

A wafer lift for lifting a series of vertically oriented wafers arranged parallel to one another in a cassette. The wafer lift comprises a lift plate and an actuator mechanism for raising the lift plate. The lift plate has a contact surface for engaging the edge of each of the wafers. The contact surface extends upward at a predetermined angle so that, when the lift plate is raised and the contact surface engages the edges of the wafers, each wafer is lifted incrementally higher than the preceding wafer. The actuator mechanism includes a bell crank rotatable about a pivotal axis for transforming rotational motion into translational motion. The bell crank has first and second crank arms that extend radially from the pivotal axis and an arcuate member that extends circumferentially between and joining the crank arms. Thus, the arcuate member forms the circumferential perimeter of the bell crank. The actuator mechanism also includes a transmission mechanism for transmitting the translational motion of the perimeter of the bell crank to the lift plate to raise the lift plate so that the contact surface engages the edges of the wafers. The transmission mechanism consists of a lift belt linking the bell crank and the lift plates. One end of the lift belt is attached to the perimeter of the bell crank and the other end is operatively connected to the lift plate for vertical movement therewith. The lift belt runs under a first roller and over a second roller. The belt has a first segment between the bell crank and the first roller, a second segment between the first and second rollers, and a third segment between the second roller and the lift plate. The rollers are configured so that rotation of the bell crank about its pivotal axis pulls the first segment of the belt upward, the second segment downward and the third segment upward to raise the lift plate to engage and lift the wafers.