The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 03, 1991
Filed:
Jun. 30, 1989
Henrik Thurfjell, Sunnyvale, CA (US);
Robert G Ozarski, Livermore, CA (US);
General Signal Corporation, Stamford, CT (US);
Abstract
An apparatus is provided for loading and/or unloading wafers from a holding cassette to a quartz boat without scraping the wafer on the slots contained in the quartz boat; the apparatus comprising a robot and a paddle. The improvement resides in the main feature of wafer sensor means disposed on the surface of the paddle, the wafer sensor means being connected to a microprocessor which converts and digitizes an analog signal from the wafer sensor means, the analog signal indicating the position of a wafer disposed on the surface of the paddle. Further included is an arrangement for signaling the robot to compensate for the particular position of the wafer on the paddle by adjusting the position of the paddle with respect to the quartz boat. Another feature lies in the fact that sensing notches are disposed along the front, right-side and left-side edges of said paddle, each of the sensing notches having a sensor device and associated emitter means disposed on opposite sides of the sensing notches in such a manner as to permit detection of the position of the slots in the quartz boat stacking rods lying adjacent to respective sensing notches.