Cryopump method and apparatus
AssigneeEbara Technologies Incorporated
InventorsGraham J. Higham, Craig Perkins
Life of this patent
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Abstract
Cryopump apparatus and method for controlling the operating temperature of a cryoarray in a cryopump. The cryopump has means for thermally isolating one of more of the cryoarrays from the refrigeration source. The means for thermally isolating is a thermal switch formed from at least first and second switch elements made of materials having dissimilar coefficients of thermal expansion. The thermal switch is also used in isolating one of the pump's cryoarrays during a partial regeneration process. The thermal switch of the preferred embodiment may also be used to prevent one of the pump's cryoarrays from falling below a predetermined operating temperature.
Claims10
A cryopump comprising:
- refrigeration means;
- first and second cryoarrays;
- means for thermally isolating and thermally reconnecting the first cryoarray and the refrigeration means without isolating the second cryoarray from the refrigeration means;
- said means for thermally isolating and thermally reconnecting comprising a thermal shrink fit switch formed from at least first and second switch elements made of materials having dissimilar coefficients of thermal expansion.
A cryopump comprising a refrigeration means;
- a cryoarray;
- means for providing thermal conduction between the refrigeration means and the cryoarray;
- and thermal shrink fit switch means of two dissimilar materials in a shrink fit relationship for thermally isolating the cryoarray from the refrigeration means to prevent thermal conduction between the refrigeration means and the cryoarray when the thermal switch (comprises two dissimilar materials in a shrink fit relationship) is in an open position in which said dissimilar materials are separated at a predetermined temperature.
A method of regenerating a two stage cryopump comprising thermally isolating the second stage cryoarray of said cryopump from the pump refrigeration system using a thermal shrink fit switch formed from at least first and second switch elements made of materials having dissimilar coefficients of thermal expansion, releasing deposited gases from said second stage cryoarray while continuing operation of said refrigeration system, venting said released gases, and then thermally reconnecting said operating refrigeration system with said second stage cryoarray by closely coupling said dissimilar materials with one another.
Dependencies are inferred from the claim text.