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. 22, 1992
Filed:
Oct. 22, 1990
Herbert P Byrnes, Poughkeepsie, NY (US);
Richard Wahl, Fishkill, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A dual mode Z/Theta stage supports and moves a work piece such as a semiconductor wafer into position for positioning during testing. The Z/Theta stage has a peripheral four point elevator drive. The elevating suspension comprises parallel, vertically oriented, rigid lift pins which bear the weight of a top-plate. The lift pins are located about the periphery of the stage to provide stability of the support. The top plate essentially floats on the lift pins so that virtually no frictional forces are translated to lift pins. The lift pins are elevated together by the force of four matched pin lift levers, crank arms. The crank arms are driven by downward force from a vertically translating air piston which is in contact with the crank arms 31. The air piston provides a gentle force moderated by pneumatic pressure which can moderate the full force of a stepping motor which drives it.