Apparatus and method for controlling temperature in a chuck system

Abstract

An apparatus and method of controlling the temperature of a thermal chuck system are disclosed. The system includes a temperature controller which controls a temperature transition in a thermal chuck. The temperature controller comprises inputs that receive air and fluid from an air source and water source, respectively, and an output for alternately transferring the air and fluid in proportions to the thermal chuck. A time proportional controller generates the proportions by computing a proportion band in each of a plurality of control regions. The proportion bands are used by the temperature controller to manage the flow of air and fluid to the chuck such that a minimum undershoot of the temperature transition is realized.

1 . A temperature control system for a chuck comprising: 
 a first input for receiving air from an air source;    a second input for receiving a fluid from a fluid source; and    at least one output for alternately transferring the air and fluid in proportions to the chuck to control a surface temperature of the chuck.    
   
   
       2 . The temperature control system of  claim 1 , wherein the fluid is temperature-controlled.  
   
   
       3 . The temperature control system of  claim 1 , wherein the fluid comprises water.  
   
   
       4 . The temperature control system of  claim 1  further comprising: 
 a first temperature control system for controlling an increase of the surface temperature; and    a second temperature control system for controlling a decrease of the surface temperature by alternating the air and fluid in the proportions during a predefined period, the second temperature control system including low-temperature processes and controller processes for managing temperature transitions among a plurality of control regions.    
   
   
       5 . A thermal chuck system comprising: 
 a first input for receiving air from an air source;    a second input for receiving a temperature-controlled fluid from a fluid source;    at least one output for alternately transferring the air and fluid in proportions to a thermal chuck;    a first temperature control system for controlling an increase of a surface temperature; and    a second temperature control system for controlling a decrease of the surface temperature by alternating the air and fluid in the proportions during the predefined period, the second temperature control system including low-temperature processes and controller processes for managing temperature transitions among a plurality of control regions.    
   
   
       6 . The thermal chuck system of  claim 5 , wherein the fluid comprises water.  
   
   
       7 . The thermal chuck system of  claim 5 , wherein the thermal chuck is one of a 200 mm and a 300 mm thermal chuck.  
   
   
       8 . The thermal chuck system of  claim 5  further comprising a valve control box and a time proportional controller.  
   
   
       9 . The thermal chuck system of  claim 8  wherein the valve control box comprises an air valve for outputting the air and a fluid valve for outputting the temperature-controlled fluid.  
   
   
       10 . The thermal chuck system of  claim 9 , wherein the fluid valve is at least one of a high flow solenoid valve and a low flow solenoid valve.  
   
   
       11 . The thermal chuck system of  claim 9 , wherein the air valve and the fluid valve outputs the air and fluid in an alternating mode in response to the controller.  
   
   
       12 . The thermal chuck system of  claim 8 , wherein the valve control box further includes a base air valve for providing a base cooling.  
   
   
       13 . The thermal chuck system of  claim 8 , wherein the time proportional controller comprises: 
 an interface for receiving measured temperature information from the thermal chuck;    a control region processor for defining the plurality of control regions and a plurality of low-temperature regions;    a controller process in each control region; and    a low-temperature process in each low-temperature region.    
   
   
       14 . The thermal chuck system of  claim 13 , wherein the control region processor defines each control region and low-temperature region by temperature boundaries.  
   
   
       15 . The thermal chuck system of  claim 5 , wherein when a first temperature is in a first control region of the plurality of control regions, a first controller process of the first control region adjusts the air and fluid proportions, and wherein when the first temperature is transitioned to a second temperature in a second control region, a second controller process of the second control region adjusts the air and fluid proportions.  
   
   
       16 . The thermal chuck system of  claim 15 , wherein the first control region and the second control region are the same.  
   
   
       17 . The thermal chuck system of  claim 15 , wherein the first control region and the second control region are different control regions in the plurality of control regions.  
   
   
       18 . The thermal chuck system of  claim 15 , wherein a dead-band region in the second control region provides an approximate temperature region for the second temperature, and wherein the second controller process controls the dead-band region to reduce an undershoot during the transition from the first temperature to the second temperature.  
   
   
       19 . The thermal chuck system of  claim 18 , wherein the second controller process reduces the undershoot by alternating the first input of air and the second input of fluid in proportions.  
   
   
       20 . The thermal chuck system of  claim 18 , wherein the second controller process reduces the undershoot by disabling the first input of air and the second input of fluid.  
   
   
       21 . The thermal chuck system of  claim 5  further comprising temperature sensors for providing chuck temperature measurements to the thermal chuck system.  
   
   
       22 . The thermal chuck system of  claim 5 , wherein each controller process comprises a gain scheduler that computes a proportion band during the predefined period, wherein the proportion band determines the proportions of air and fluid input to the chuck during the predefined period, and wherein the proportion band is calculated in response to the chuck temperature measurements.  
   
   
       23 . A time proportional controller for controlling a thermal chuck, the controller comprising: 
 an interface for receiving a measured chuck surface temperature from the thermal chuck;    a control region processor for defining a plurality of control regions and low temperature regions;    a controller process in each control region, wherein the controller process controls a transition between temperatures of the control regions and low temperature regions; and    a low-temperature process for each low-temperature region.    
   
   
       24 . The controller of  claim 23 , wherein the controller process of each control region comprises: 
 a gain scheduler for computing a proportion band in each of the plurality of control regions, the proportion band for determining a proportion of air and fluid inputs to the thermal chuck during a predefined period; and    a dead-band mode for determining a dead-band temperature range in each control region, and for reducing an undershoot formed during the temperature transition.    
   
   
       25 . The controller of  claim 23 , wherein each control region and low temperature region is separated by temperature boundaries;  
   
   
       26 . The controller of  claim 24 , wherein the controller minimizes an undershoot by disabling the proportion of air and fluid inputs during the predefined period when a measured temperature in the dead-band temperature range.  
   
   
       27 . The controller of  claim 24  further controlling a heater for transitioning the measured temperature to a desired temperature when the measured temperature is lower than the desired temperature.  
   
   
       28 . The controller of  claim 27  further controlling a plurality of valves for transitioning the measured temperature to the desired temperature when the measured temperature is higher than the desired temperature.  
   
   
       29 . A method for controlling a chuck temperature comprising: 
 receiving air from an air source;    receiving fluid from a fluid source; and    alternately transferring the air and fluid in proportions to the chuck.    
   
   
       30 . The method of  claim 29  further comprising controlling a temperature of the fluid.  
   
   
       31 . The method of  claim 29  further comprising: 
 controlling an increase of a surface temperature of the chuck; and    controlling a decrease of the surface temperature by alternating the air and fluid in the proportions during a predefined period.    
   
   
       32 . The method of  claim 31  further comprising managing temperature transitions among a plurality of control regions.  
   
   
       33 . A method for controlling a temperature of a chuck comprising: 
 receiving air from an air source;    receiving a temperature-controlled fluid from a fluid source;    alternately transferring the air and fluid in proportions to the chuck;    controlling an increase of the chuck temperature;    controlling a decrease of the chuck temperature by alternating the air and fluid in the proportions during a predefined period; and    managing temperature transitions among a plurality of control regions and low-temperature regions.    
   
   
       34 . The method of  claim 33 , wherein the air and fluid are outputted in an alternating mode in response to a time proportional controller.  
   
   
       35 . The method of  claim 34  further comprising receiving measured temperature information from the chuck.  
   
   
       36 . The method of  claim 33 , wherein each control region and low-temperature region is defined by temperature boundaries.  
   
   
       37 . The method of  claim 33  further comprising adjusting air and fluid proportions in a first control region of the plurality of control regions when a first temperature is in the first control region, wherein when the first temperature is transitioned to a second temperature in a second control region, adjusting air and fluid proportions in the second control region.  
   
   
       38 . The method of  claim 37 , wherein the first control region and the second control region are the same.  
   
   
       39 . The method of  claim 37 , wherein the first control region and the second control region are different control regions in the plurality of control regions.  
   
   
       40 . The method of  claim 37  further comprising providing an approximate temperature region as a dead-band region in the second control region for the second temperature, and controlling the dead-band region to reduce an undershoot during the transition from the first temperature to the second temperature.  
   
   
       41 . The method of  claim 40  further comprising reducing the undershoot by alternating the air and fluid in proportions.  
   
   
       42 . The method of  claim 40  further comprising reducing the undershoot by disabling an input of air and an input of fluid.  
   
   
       43 . The method of  claim 33  further comprising computing a proportion band during the predefined period, wherein the proportion band determines the proportions of air and fluid input to the chuck during the predefined period, and wherein the proportion band is calculated in response to the chuck temperature measurements.  
   
   
       44 . A method for controlling a chuck temperature comprising: 
 receiving a measured chuck surface temperature from a thermal chuck;    defining a plurality of control regions, each control region having a controller process, and low temperature regions, each low temperature region having a low-temperature process; and    controlling a transition between temperatures of the control regions and low-temperature regions.    
   
   
       45 . The method of  claim 44 , wherein each control region and low temperature region is separated by temperature boundaries.  
   
   
       46 . The method of  claim 44 , wherein controlling the transition between temperatures of the control regions and low temperature regions further comprises: 
 computing a proportion band in each control region, the proportion band determining a proportion of air and fluid inputs to the thermal chuck during a predefined period; and    determining a dead-band temperature range in each control region, and reducing an undershoot formed during the temperature transition.    
   
   
       47 . The method of  claim 46  further comprising minimizing an undershoot by disabling the proportion of air and fluid inputs during the predefined period when a measured temperature is in the dead-band temperature range.  
   
   
       48 . The method of  claim 46  further comprising controlling a heater for transitioning the measured temperature to a desired temperature when the measured temperature is lower than the desired temperature.  
   
   
       49 . The method of  claim 48  further comprising controlling a plurality of valves for transitioning the measured temperature to the desired temperature when the measured temperature is higher than the desired temperature.