Apparatus and method for thermal management of a mass flow controller
AssigneeMKS Instruments, Inc.
InventorsJesse Ambrosina, Isao Suzuki, Ali Shajii
Life of this patent
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Abstract
A thermal mass flow controller includes a sensor assembly, a valve assembly, and mass flow controller housing. A thermal ground limits the conductive thermal path between the mass flow controller housing and the sensor assembly and, due to the limited cross-section of the thermal ground, substantially eliminates externally imposed thermal gradients within the sensor assembly. The controller also includes a thermally dissipative element that conducts thermal energy along a path from the valve assembly away from the sensor assembly.
Claims21
A thermal mass flow controller housing, comprising:
- a) a first chamber for enclosing a bypass tube, the first chamber including a wall for mounting a second chamber;
- b) a second chamber for enclosing a sensor tube, the second chamber including a wall for mounting to said wall of the first chamber, both walls including input and output apertures formed therethrough to provide access to the bypass tube for the sensor tube;
- c) a thermal ground formed between the first and second chambers, the thermal ground comprising substantially the entire thermal conductive path between the first and second chambers;
- and
- d) a conductive thermal element in conductive thermal contact conductive with at least a portion of the second chamber and formed to conduct thermal energy from within the second chamber away from the first chamber.
A thermal mass flow controller comprising:
- a) a control valve assembly for controlling the rate of fluid flow through a conduit, the control valve assembly in thermally conductive communication with a thermal mass flow controller housing;
- b) a sensor assembly for sensing the rate of flow of the fluid through the conduit as a function of the difference in temperature between first and second regions of the conduit and for generating a control signal as a function of said rate of fluid flow, the sensor assembly in thermally conductive communication with said mass flow controller housing;
- c) a thermal ground formed between the valve assembly and the sensor assembly, the thermal ground comprising substantially the entire thermal conductive path between the sensor assembly and the valve assembly;
- and
- d) a conductive thermal element in conductive thermal contact with at least a portion of the second chamber and formed to conduct thermal energy from within the second chamber away from the first chamber.
Dependencies are inferred from the claim text.