US Patent 9352466 Robot positioning system for semiconductor tools

A system and method for adjusting the position and orientation of a feed arm associated with a wafer handling robot. In one embodiment, the system includes a positioning plate detachably carried by the feed arm and insertable therewith into a wafer carrier. The positioning plate includes graphic alignment indicia. An alignment apparatus is provided configured for insertion into wafer-holding slots in the wafer carrier. The apparatus includes at least one digital image sensor. With the positioning plate and alignment apparatus located in the wafer carrier, an image of the alignment indicia is displayed on a video monitor by the image sensor for comparison to a reference mark superimposed on the monitor for determining the relative position and orientation of the feed arm with respect to the wafer carrier. Some embodiments of the apparatus further include a distance detection device to measure the distance to the plate.