Edge-gripping pre-aligner

摘要

An apparatus for holding and orienting a wafer having an alignment feature, and including a movable robot arm; and an end effector attached to an end of the robot arm, the end effector including a gripping mechanism which during operation both holds the wafer and rotates it about an axis that is perpendicular to the plane of the wafer and a sensing element for detecting the alignment feature on the wafer as the gripping mechanism rotates the wafer past the sensing element.