Temptronic Corporation

Thomas J Schey

Paul A Getchel

William M Stone

Robert R Lopez

Kenneth M Cole, Sr

Henry A Lyden

Dana G Butcher

George Eager

Peter Selverstone

A workpiece chuck includes an upper assembly on which can be mounted a flat workpiece such as a semiconductor wafer. A lower assembly is mountable to a base that supports the chuck. A non-constraining attachment means such as vacuum, springs or resilient washers applied to the chuck holds the upper assembly to the lower assembly, the lower assembly to the base and can hold the wafer to the top surface of the upper assembly. By holding the chuck together by non-constraining means, the chuck layers can move continuously relative to each other under expansion forces caused by temperature effects, such that mechanical stresses on the chuck and resulting deformation of the chuck and workpiece over temperature are substantially eliminated. A plurality of support members including inclined surfaces provided between an upper and lower portion of the chuck maintain the top surface of the chuck and any workpiece mounted thereon at a constant height over temperature.

Workpiece chuck with guard layer having vacuum distribution pattern

Workpiece chuck

An improved system for and method of precisely controlling the temperature at a predetermined location at a preselected temperature selected from a range of temperatures is described. The preferred system for carrying out the preferred method includes a mixing valve for separating a fluid stream into first and second component streams and adjustable in response to a first contol signal so as to control the amount of separation of first and second component streams. The preferred system also includes a heater for heating the first compponent stream in response to a second control signal, a first evaporator for cooling the second component stream and a conduit for combining the heated and cooled component streams so as to provide a mixed stream to the predetermined location. The first and second control signals are provided as a function of the preselected temperature, the temperature of the heated first component stream, the temperature of the mixed stream and the temperature at said predetermined location. The system is also preferably provided with a second evaporator for recooling the mixed stream as it is recirculated if the temperature at the predetermined location does not drop below some predetermined level. The second evaporator provides partial recooling of the mixed stream when the temperature difference between the preselected temperature and the temperature at the predetermined location is below some preselected value and maximum recooling when above the preselected value so long as the temperature at the predetermined location does not drop below the predetermined level.

Mixing valve air source

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Woonsocket, RI, United States of America

Thomas J Schey