# US 5,706,890 A · Temperature control apparatus with recirculated coolant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,890 A - Document ID: US5706890A - Status: Granted - Kind: A - Application number: 08/184,681 - Filed: 1994-01-21 - Granted: 1998-01-13 - Earliest claimed: 1994-01-21 - Assignees: FSI International, Inc. - Inventors: Ben J. Sloan; William G. Reed - Web page: https://patentgrep.com/patent/US5706890A ## Abstract A temperature control and process for adjusting the temperature of a workstation and a work medium at a workstation to a predetermined temperature. The temperature control comprises a cooling vehicle such as a heat exchanger, a coolant temperature sensor and control, a source of fluid coolant such as a manifold, a recirculating pump, a flow line to circulate the coolant to the workstation with the flow line containing a flow regulator and a heater, a bypass valve for bypassing the flow regulator and heater, and a workstation temperature sensor and control. The workstation temperature control controls the operation of the heater and bypass valve so that the temperature of the coolant is below the desired temperature for the workstation, thus achieving a rapid transient response while avoiding overcooling. The coolant temperature control and workstation temperature control may be in a temperature control computer, thus providing a large number of different operating sequences. A number of embodiments of workstations are also described. ## Claims ### Claim 1 A temperature control for adjusting the temperature of a workstation and a work medium at a workstation to a predetermined temperature, comprising: a source of fluid coolant, a cooling vehicle, main coolant temperature sensor and main coolant temperature control for detecting and maintaining the temperature of the fluid coolant at a temperature below said predetermined temperature, a flow line, a return line, and a recirculating pump for receiving fluid coolant from said source of fluid coolant and providing fluid coolant to the workstation and producing cooling of the workstation and work medium therein, a workstation temperature sensor and workstation temperature control for detecting and regulating the temperature of the workstation, a coolant heater in said flow line responsive to said workstation temperature control for heating the coolant being supplied to the workstation to a temperature nearly equal to said predetermined temperature as to maintain the workstation and work medium at said predetermined temperature, said workstation temperature control reducing the heating by said heater while a substantial differential exists between the workstation temperature and said predetermined temperature, and said workstation temperature control increasing the heating by said heater as said differential decreases and as the workstation temperature nearly achieves said predetermined temperature, a flow regulator in said flow line for maintaining the desired rate of flow of coolant through said flow line, and a bypass valve for bypassing both said heater and said flow regulator, thereby providing a flow of unwarmed coolant to the workstation at an increased rate of flow, said bypass valve being responsive to said workstation temperature control. ### Claim 2 (depends on 1) A temperature control as in claim 1, wherein said main coolant temperature control and said workstation temperature control are a temperature control computer. ### Claim 3 (depends on 1) A temperature control as in claim 1, wherein said temperature control controls the temperature of a plurality of workstations and work media therein. ### Claim 4 A temperature control for adjusting the temperature of a workstation and a work medium at a workstation to a predetermined temperature, comprising: a workstation, a source of fluid coolant, a cooling vehicle, main coolant temperature sensor and main coolant temperature control for detecting and maintaining the temperature of the fluid coolant at a temperature below said predetermined temperature, a flow line, a return line, and a recirculating pump for receiving fluid coolant from said source of fluid coolant and providing fluid coolant to the workstation and producing cooling of the workstation and work medium therein, a workstation temperature sensor and workstation temperature control for detecting and regulating the temperature of the workstation, a coolant heater in said flow line responsive to said workstation temperature control for heating the coolant being supplied to the workstation to a temperature nearly equal to said predetermined temperature as to maintain the workstation and work medium at said predetermined temperature, said workstation temperature control reducing the heating by said heater while a substantial differential exists between the workstation temperature and said predetermined temperature, and said workstation temperature control increasing the heating by said heater as said differential decreases and as the workstation temperature nearly achieves said predetermined temperature, a flow regulator in said flow line for maintaining the desired rate of flow of coolant through said flow line, and a bypass valve for bypassing both said heater and said flow regulator, thereby providing a flow of unwarmed coolant to the workstation at an increased rate of flow, said bypass valve being responsive to said workstation temperature control. ### Claim 5 (depends on 4) A temperature control as in claim 4, wherein said workstation comprises a cooling plate for supporting a wafer whose temperature is to be regulated. ### Claim 6 (depends on 4) A temperature control as in claim 4, wherein said workstation comprises a module having an upper compartment, a lower compartment, and a cooling plate separating said upper compartment from said lower compartment, said module regulating the temperature of materials in said upper compartment and said lower compartment. ### Claim 7 (depends on 4) A temperature control as in claim 4, wherein said main coolant temperature control and said workstation temperature control are a temperature control computer. ### Claim 8 (depends on 4) A temperature control as in claim 4, wherein said temperature control controls the temperature of a plurality of workstations and work media therein. ### Claim 9 A temperature control for adjusting the temperature of a workstation and a work medium at a workstation to a predetermined temperature, comprising: workstation temperature sensing means to determine the temperature of the workstation, a source of fluid coolant and means for maintaining the fluid coolant at a temperature below said predetermined temperature, coolant circulating means comprising a flow line delivering coolant from said source and to and through the workstation and adjusting the temperature of the workstation and work medium therein, a coolant heater in the flow line heating the coolant being supplied to the workstation to a temperature nearly equal to said predetermined temperature as to maintain the workstation and work medium at said predetermined temperature, control means for the heater and modulating the heating thereof, said control means reducing the heating by said heater while a substantial differential exists between the workstation temperature and said predetermined temperature, and said control means increasing the heating by said heater as said differential decreases and as the workstation temperature nearly achieves said predetermined temperature; means for regulating the flow of coolant in the flow line; and means for bypassing said flow regulating means and said heater, and wherein said control means controls said bypass means. ### Claim 10 (depends on 9) A temperature control as in claim 9, wherein said control means is a temperature control computer, and the computer's program controls said heater and said bypass means. ### Claim 11 (depends on 9) A temperature control as in claim 9, wherein said temperature control controls the temperature of a plurality of workstations and work media therein. ### Claim 12 A temperature control for adjusting the temperature of a workstation and a work medium at a workstation to a predetermined temperature, comprising: a workstation, workstation temperature sensing means to determine the temperature of the workstation, a source of fluid coolant and means for maintaining the fluid coolant at a temperature below said predetermined temperature, coolant circulating means comprising a flow line delivering coolant from said source and to and through the workstation and producing cooling of the workstation and work medium therein, a coolant heater in the flow line heating the coolant being supplied to the workstation to a temperature nearly equal to said predetermined temperature as to maintain the workstation and work medium at said predetermined temperature, control means for the heater and modulating the heating thereof, said control means reducing the heating by said heater while a substantial differential exists between the workstation temperature and said predetermined temperature, and said control means increasing the heating by said heater as said differential decreases and as the workstation temperature nearly achieves said predetermined temperature; means for regulating the flow of coolant in the flow line; and means for bypassing said flow regulating means and said heater, and wherein said control means controls said bypass means. ### Claim 13 (depends on 12) A temperature control as in claim 12, wherein said control means is a temperature control computer, and the computer's program controls said heater and said bypass means. ### Claim 14 (depends on 12) A temperature control as in claim 12, wherein said workstation comprises a cooling plate for supporting a wafer whose temperature is to be regulated. ### Claim 15 (depends on 12) A temperature control as in claim 12, wherein said workstation comprises a module having an upper compartment, a lower compartment, and a cooling plate separating said upper compartment from said lower compartment, said module regulating the temperature of materials in said upper compartment and said lower compartment.