Substrate alignment system

摘要

A system for aligning an end effector with a substrate in a substrate transport apparatus. The system comprises a first sensor connected to the end effector and a controller for moving the substrate transport apparatus. The sensor has a sensing path pointed in an outward direction. The sensing path does not intersect the substrate when the substrate is located on the end effector. The controller for moving the substrate transport apparatus moves the substrate transport apparatus, based at least partially upon input from the sensor, to position the end effector at a predetermined position relative to the substrate to pick up the substrate onto the end effector.

主权项

1. A method of aligning substrates in stack of substrates, the method comprising:
scanning positions of first reference points on respective first edges of at least two of the substrates by measuring a first distance between the first reference point on each of the substrates and a scanner; scanning positions of second reference points on the respective first edges by measuring a second distance between the second reference point on each of the substrates and the scanner so that for each substrate there is more than one measured distance, wherein the first and second reference points of a respective substrate are located on a common side of the respective substrate and scanning the positions of more than one of the first reference points is completed before commencing scanning of any of the positions of the second reference points; subsequently moving the at least two substrates with an end effector; and aligning the substrates as the substrates are moved; wherein the steps of scanning the positions of the first and second reference points occurs from on the common side of the respective substrate prior to end effector entry into the stack of substrates and before the at least two substrates are subsequently moved.