Temperature control of individual tools in a cluster tool system
First Claim
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.
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Accused Products
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.
33 Citations
4 Claims
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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:
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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. - View Dependent Claims (2, 3)
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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:
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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.
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Specification