Rotary union for semiconductor wafer applications

摘要

A rotary union is provided for chemical mechanical polishing of silicon wafers, especially silicon wafers containing chemically sensitive integrated circuit structures. A rotary union is provided with a union rotor and union stator, coupled at the free end of a support spindle carrying a CMP polishing table. In the preferred embodiment the rotary union is joined to a coolant union forming the lower end of the support spindle. A passageway through the union rotor extends past the bottom end of the coolant union rotating part to avoid contact of fluid transmitted through the passageway formed in the union rotor, with the rotating part of the coolant union.