WORKPIECE CHUCK

摘要

A workpiece chuck (10) includes an upper assembly (26) on which can be mounted a flat workpiece such as a semiconductor wafer. A lower assembly (30) is mountable to a base (48) that supports the chuck (10). A non-constraining attachment means such as vacuum, springs or resilient washers applied to the chuck (10) holds the upper assembly (26) to the lower assembly (30), the lower assembly (30) to the base (48) and can hold the wafer to the top surface (12) of the upper assembly (26). A heater (16) and a heat sink (14) can be included in the lower assembly (30) to allow for temperature cycle testing of the wafer. By holding the chuck (10) together by non-constraining means, the chuck layers can move continuously relative to each other under expansion forces caused by temperature effects. Mechanical stresses on the chuck (10) and resulting deformation of the chuck (10) and workpiece over temperature are substantially eliminated.