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:
Jul. 13, 1976
Filed:
Aug. 02, 1974
Gerd Schliemann, Saratoga, CA (US);
The Computervision Corporation, Bedford, MA (US);
Abstract
An air bearing piston assembly for semiconductor mask-to-wafer aligner which utilizes a plurality of air bearings to produce a very low friction and a very predictable force system for bringing a mask into contact and level with a semiconductor wafer. Two small driver pistons are employed to move a main piston. An outside air bearing between a rotation clamp ring and the main piston and an inside air bearing between a piston guide and the main piston produce an almost frictionless system. A third air bearing is established between a leveling ball and the ball table so that the wafer with the chunk can level accurately with a minimum of force against the mask.