Temperature control of individual tools in a cluster tool system

• US 6,499,535 B2
• Filed: 06/13/2001
• Issued: 12/31/2002
• Est. Priority Date: 09/16/1997
• Status: Expired due to Term

• Current Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: B/E Aerospace Incorporated (Spirit Realty Capital, Inc.)
• Inventors: Cowans, Kenneth W.
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): MCKINNON, TERRELL L
• Application Number:
  US09/879,006
• Publication Number:
  US 20020029877A1
• Time in Patent Office: 566 Days
• Field of Search: 165/206, 165/263, 165/264, 165/80.4, 165/104.33, 622/592, 625/13, 62D/IG.10, 624/34, 621/85, 361/699
• US Class Current: 165/206
• CPC Class Codes: B23Q 11/10 Arrangements for cooling or lubricating tools or work incorporated in tools, see the relevant subclass for the tool , e.g. B23B27/10, B23B51/06, B23C5/28, B23D77/006; for circular saw blades B23D59/02, for cooling grinding surfaces B24B55/02
• CPC Class Codes: B23Q 11/141 using a closed fluid circuit for cooling or heating
• CPC Class Codes: B23Q 11/143 comprising heating means
• CPC Class Codes: F25B 2309/06 Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
• CPC Class Codes: F25B 2341/0681 the sensor is heated
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 41/20 Disposition of valves, e.g. of on-off valves or flow control valves expansion valves F25B41/31
• CPC Class Codes: F25B 41/335 via diaphragms
• CPC Class Codes: F25B 41/34 with the valve member being actuated by electric means, e.g. by piezoelectric actuators
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide
• CPC Class Codes: F25D 17/02 for circulating liquids, e.g. brine
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A temperature control unit for independent control of a number of independent channels, as can exist with a cluster tool used for semiconductor fabrication, has high efficiency, long term life and reliability, and requires only a small floor area. To these ends, the unit employs a single high capacity refrigeration system and disposes a number of separate temperature control channels for the individual tools, with only some channels receiving refrigerant. Low temperature channels use high pressure, sub-cooled refrigerant for chilling the heat transfer fluid to selected levels controlled by proportional valves adjusting refrigerant flow through evaporator heat exchanger units which cool heat transfer fluid. Moderate temperature channels cool the heat transfer fluid for associated tools to an ambient temperature level. The tools may, as needed, be heated by elements in the separate control channels, the control levels for both cooling and heating being determined by servo circuits programmed to measure actual and establish desired temperature levels.

Claims

1. A control loop system for maintaining the temperature of an operating tool at a selected level within a substantial temperature range that includes levels above and below the ambient, using a chilled pressurized refrigerant and a thermal transfer fluid, comprising:

means defining a control loop for a thermal transfer fluid communicating in thermal interchange relation with the tool, the loop further including pump means for the thermal transfer fluid;

electrical heater means disposed in the control loop between the pump and tool and controllable in response to an energizing temperature control signal;

heat exchanger means in the loop and receiving the thermal transfer fluid and the chilled refrigerant;

proportional valve means coupled to receive the chilled refrigerant in the heat exchanger means for controlling the flow of chilled refrigerant in the heat exchanger means such as to maintain a selected temperature level in the below ambient temperature range in the thermal transfer fluid transferred to the tool; and

means coupled to the heater means and providing a control signal for controlling the heater means to alternatively maintain a selected temperature level in the thermal transfer fluid that is above the ambient temperature level.

2. A system as set forth in claim 1 above, wherein the refrigerant is a subcooled refrigerant and the control loop system receives the subcooled refrigerant and wherein the heat exchanger means includes an internal evaporator coupled to receive the refrigerant at a rate controlled by the proportional valve means and providing a vaporized refrigerant at a temperature to cool the thermal transfer fluid to the selected level in the below ambient temperature range.

3. A system as set forth in claim 1 above, wherein the proportional valve means comprises a proportional integral derivative system including a valve element means for controlling refrigerant flow rate to the evaporator, the proportional valve means comprising chambers defining first and second interior volumes confining a pressurized gas and including an interconnecting gas conduit, and the chamber defining the first volume being in thermal communication with a thermal energy source controlling the internal pressure in the first interior volume, the chamber defining the second interior volume including a flexible diaphragm and a valve stem, the flexible diaphragm forming a moveable wall of the second interior volume, the valve stem controlling refrigerant flow in accordance with its position, and being controlled in position by the pressure in the second interior volume.

4. A control loop system for maintaining the temperature of an operating tool at a selected level within a substantial temperature range that includes levels above and below the ambient, using a chilled pressurized refrigerant and a thermal transfer fluid, comprising:

means defining a control loop for a thermal transfer fluid communicating in thermal interchange relation with the tool, the loop further including fluid pump means for the thermal transfer fluid, the fluid pump means comprising a pressuring pump having an inlet and outlet;

electrical heater means disposed in the control loop between the pump and tool and controllable in response to an energizing temperature control signal;

heat exchanger means in the loop and receiving the thermal transfer fluid and the chilled refrigerant;

proportional valve means coupled to receive the chilled refrigerant in the heat exchanger means for controlling the flow of chilled refrigerant in the heat exchanger means such as to maintain a selected below ambient temperature in the thermal transfer fluid transferred to the tool;

means coupled to the heater means for controlling the heater means to alternatively maintain a selected temperature level that is above the ambient in the thermal transfer fluid,

and where the system further includes conduits coupling thermal transfer fluid from the control loop system to the tool whose temperature is to be maintained, and valve means at the input and output lines at the control loop subsystem, for selectively closing off the inlet and outlet lines, and wherein the system includes pressurized gas injection means coupled to the control loop system such that thermal transfer fluid can be driven out of the conduits and a selected tool, and the conduits and tool can be isolated for maintenance or replacement purposes.