Loading patent…
AssigneeNor-Cal Products, Inc.
InventorsEmmanuel Vyers, William Ballard, David Kruse, Sean Mallory, Per Cederstav
Estimating the term…
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). The method of the present invention more accurately positions the valve, and accordingly enhances the overall precision and allowable loop-gain of the pressure control system by providing the valve drive with feedback as to the actual angular position of the valve in extremely high resolution
An improved valve control assembly for controlling the position of a valve, comprising:
An improved valve control assembly for controlling the position of a valve, said valve comprising a valve stem for actuating said valve, the valve control assembly comprising:
A process for controlling the pressure within a chamber, comprising the steps of:
A process for controlling the fluid flow through a conduit, comprising the steps of:
Dependencies are inferred from the claim text.