Abstract: A drive unit for a gate valve controls a flow rate of fluid passing through an opening in a valve seat by forward and backward moving a valve plate against the opening in the valve seat. This drive unit includes a shaft connected to the valve plate, a linear motor for driving the shaft and drive control means to control the drive of the linear motor. The linear motor has a plurality of coils for generating a magnetic field by electric current and a permanent magnet assembly to react to the magnetic field generated by the plurality of coils. The plurality of coils forms a stator while the permanent magnet assembly is connected to the shaft and displaced together with the shaft to form a mover to forward and backward move the valve plate. Each of the plurality of coils is connected to its own control circuit and the drive control means individually controls the current flowing through each of the plurality of coils via the control circuit.

Abstract: A vacuum valve includes a valve plate that covers an exhaust port of a vacuum chamber, and a poppet type actuator that drives the valve plate in an axial direction orthogonal to a surface of the vacuum chamber on which the exhaust port is provided. The actuator includes a shaft that is connected to the valve plate, a drive unit that is disposed side by side with the shaft in a radial direction of the shaft and includes a ball screw shaft and a drive source that rotates the ball screw shaft, and a connection part that connects the ball screw shaft and the shaft and moves in the axial direction together with the shaft to a position where the valve plate covers the exhaust port.

Abstract: A drive unit for a gate valve controls a flow rate of fluid passing through an opening in a valve seat by forward and backward moving a valve plate against the opening in the valve seat. This drive unit includes a shaft connected to the valve plate, a linear motor for driving the shaft and drive control means to control the drive of the linear motor. The linear motor has a plurality of coils for generating a magnetic field by electric current and a permanent magnet assembly to react to the magnetic field generated by the plurality of coils. The plurality of coils forms a stator while the permanent magnet assembly is connected to the shaft and displaced together with the shaft to form a mover to forward and backward move the valve plate. Each of the plurality of coils is connected to its own control circuit and the drive control means individually controls the current flowing through each of the plurality of coils via the control circuit.

Abstract: A vacuum valve includes a valve plate that covers an exhaust port of a vacuum chamber, and a poppet type actuator that drives the valve plate in an axial direction orthogonal to a surface of the vacuum chamber on which the exhaust port is provided. The actuator includes a shaft that is connected to the valve plate, a drive unit that is disposed side by side with the shaft in a radial direction of the shaft and includes a ball screw shaft and a drive source that rotates the ball screw shaft, and a connection part that connects the ball screw shaft and the shaft and moves in the axial direction together with the shaft to a position where the valve plate covers the exhaust port.

Abstract: A gas pressure within a treatment chamber 2 can be more accurately regulated to a predicted target pressure whereby there can be provided a pressure control apparatus which can easily and speedily regulate the gas pressure for various combination of the treatment chamber 2, a sanction chamber 3 and a valve 4. A required inflow rate (Qi) at which it is necessary for gas to flow into the treatment chamber 2 in order to reach a preset target pressure (Psp) within the treatment chamber is calculated on the basis of the expression of Qi=Qo+(P/?t)V and the thus calculated required inflow rate (Qi) is flown into the treatment chamber 2 to control the pressure within the treatment chamber 2 to the required pressure (Psp).

Abstract: A gas pressure within a treatment chamber 2 can be more accurately regulated to a predicted target pressure whereby there can be provided a pressure control apparatus which can easily and speedily regulate the gas pressure for various combination of the treatment chamber 2, a sanction chamber 3 and a valve 4. A required inflow rate (Qi) at which it is necessary for gas to flow into the treatment chamber 2 in order to reach a preset target pressure (Psp) within the treatment chamber is calculated on the basis of the expression of Qi=Qo+(P/?t)V and the thus calculated required inflow rate (Qi) is flown into the treatment chamber 2 to control the pressure within the treatment chamber 2 to the required pressure (Psp).

Abstract: A predicted outflow rate (Qo) at which gas is discharged from a process chamber 2 via a vacuum pump 3 is computed, and an input flow rate (Qi) is calculated in order to reach a preset target pressure (Psp). The input flow rate (Qi) is calculated, on the basis of the expression Qi=Qo+(?P/?t)V, from a known volume (V) of the process chamber 2 and a pressure change rate (?P/?t) obtained from the current pressure (P1) within the process chamber 2 to reach the target pressure (Psp). A current predicted outflow rate (Qo) is estimated on the basis of the expression Qo(n)=P2*f1(P2), from the current pressure (P2) within the vacuum pump 3 and a known characteristic pumping rate (Sp=f1(P2)) of the vacuum pump 3 under preset pressure.

Abstract: A predicted outflow rate (Qo) at which gas is discharged from a process chamber 2 via a vacuum pump 3 is computed, and an input flow rate (Qi) is calculated in order to reach a preset target pressure (Psp). The input flow rate (Qi) is calculated, on the basis of the expression Qi=Qo+(?P/?t)V, from a known volume (V) of the process chamber 2 and a pressure change rate (?P/?t) obtained from the current pressure (P1) within the process chamber 2 to reach the target pressure (Psp). A current predicted outflow rate (Qo) is estimated on the basis of the expression Qo(n)=P2*f1(P2), from the current pressure (P2) within the vacuum pump 3 and a known characteristic pumping rate (Sp=f1(P2)) of the vacuum pump 3 under preset pressure.

Abstract: A closed loop pressure controller system that sets, measures and controls the process pressure within a semiconductor process is shown. The system is commonly composed of a pressure sensor to collect the pressure information, a controller box that hosts the control electronics, and a valve to physically affect the conductivity of the inlet or outlet gas line and accordingly the process pressure. The present invention differs from the prior art by using closed-loop motor control of the valve, rather than the method of the prior art, where the valve position is controlled by a stepper motor actuator driven in an open loop fashion. It is demonstrated that the utility of such prior art open-loop configurations is limited by the fact that the achievable precision of the valve position is hindered by static friction in the valve system, and the non-linear character of the torque versus shaft-angle of the motor (among other error components).

Abstract: A closed loop pressure controller system that sets, measures and controls the process pressure within a semiconductor process is shown. The system is commonly composed of a pressure sensor to collect the pressure information, a controller box that hosts the control electronics, and a valve to physically affect the conductivity of the inlet or outlet gas line and accordingly the process pressure. The present invention differs from the prior art by using closed-loop motor control of the valve, rather than the method of the prior art, where the valve position is controlled by a stepper motor actuator driven in an open loop fashion. It is demonstrated that the utility of such prior art open-loop configurations is limited by the fact that the achievable precision of the valve position is hindered by static friction in the valve system, and the non-linear character of the torque versus shaft-angle of the motor (among other error components).

Abstract: A method for controlling the gas flow within a digital mass flow controller. The method calculates a digitally enhanced flow rate signal that more accurately represents an actual flow rate through the digital mass flow controller. The digitally enhanced flow rate is calculated using a sensed flow rate signal output from a flow sensor, a scaled first derivative of the sensed flow rate signal, and a scaled, filtered second derivative of the sensed flow rate signal. A set-point signal is compared to the digitally enhanced flow rate signal to generate a digital error signal. The digital error signal is provided to a digitally realized PI (proportional integral) controller. The PI controller generates a digital control signal which is used to control a valve in the digital mass flow controller.

Abstract: A closed loop pressure controller system that sets, measures and controls the process pressure within a semiconductor process is shown. The system is commonly composed of a pressure sensor to collect the pressure information, a controller box that hosts the control electronics, and a valve to physically affect the conductivity of the inlet or outlet gas line and accordingly the process pressure. The present invention differs from the prior art by using closed-loop motor control of the valve, rather than the method of the prior art, where the valve position is controlled by a stepper motor actuator driven in an open loop fashion. It is demonstrated that the utility of such prior art open-loop configurations is limited by the fact that the achievable precision of the valve position is hindered by static friction in the valve system, and the non-linear character of the torque versus shaft-angle of the motor (among other error components).

Abstract: A method for generating a valve drive signal using a variable gain PI controller in a mass flow controller. The method includes multiplying an error signal with a proportional gain factor to generate a proportional signal. The method also includes implementing an integral function on the error signal. The integral function includes an integral gain factor which functions as the variable gain in the PI controller. For set-point signals less than a normalized predetermined percentage of the maximum set-point, the gain factor is equal to [ ( 1 0.1 - 1 ) ⁢   ⁢ A + B ] , where A is a first gain constant and B is a second gain constant.

Abstract: A closed loop pressure controller system that sets, measures and controls the process pressure within a semiconductor process is shown. The system is commonly composed of a pressure sensor to collect the pressure information, a controller box that hosts the control electronics, and a valve to physically affect the conductivity of the inlet or outlet gas line and accordingly the process pressure. The present invention differs from the prior art by using closed-loop motor control of the valve, rather than the method of the prior art, where the valve position is controlled by a stepper motor actuator driven in an open loop fashion. It is demonstrated that the utility of such prior art open-loop configurations is limited by the fact that the achievable precision of the valve position is hindered by static friction in the valve system, and the non-linear character of the torque versus shaft-angle of the motor (among other error components).

Abstract: A method for controlling the gas flow within a digital mass flow controller. The method calculates a digitally enhanced flow rate signal that more accurately represents an actual flow rate through the digital mass flow controller. The digitally enhanced flow rate is calculated using a sensed flow rate signal output from a flow sensor, a scaled first derivative of the sensed flow rate signal, and a scaled, filtered second derivative of the sensed flow rate signal. A set-point signal is compared to the digitally enhanced flow rate signal to generate a digital error signal. The digital error signal is provided to a digitally realized PI (proportional integral) controller. The PI controller generates a digital control signal which is used to control a valve in the digital mass flow controller.

Abstract: A closed loop pressure controller system that sets, measures and controls the process pressure within a semiconductor process is shown. The system is commonly composed of a pressure sensor to collect the pressure information, a controller box that hosts the control electronics, and a valve to physically affect the conductivity of the inlet or outlet gas line and accordingly the process pressure. The present invention differs from the prior art by using closed-loop motor control of the valve, rather than the method of the prior art, where the valve position is controlled by a stepper motor actuator driven in an open loop fashion. It is demonstrated that the utility of such prior art open-loop configurations is limited by the fact that the achievable precision of the valve position is hindered by static friction in the valve system, and the non-linear character of the torque versus shaft-angle of the motor (among other error components).

Abstract: A method for controlling the gas flow within a digital mass flow controller. The method calculates a digitally enhanced flow rate signal that more accurately represents an actual flow rate through the digital mass flow controller. The digitally enhanced flow rate is calculated using a sensed flow rate signal output from a flow sensor, a scaled first derivative of the sensed flow rate signal, and a scaled, filtered second derivative of the sensed flow rate signal. A set-point signal is compared to the digitally enhanced flow rate signal to generate a digital error signal. The digital error signal is provided to a digitally realized PI (proportional integral) controller. The PI controller generates a digital control signal which is used to control a valve in the digital mass flow controller.