Hitachi Metals, Ltd.

Patrick Albright

Alexei V Smirnov

Ryan Johnson

Arun Nagarajan

Cy Jordan

Michael John Zolock

Alexander Fernandez

Systems and methods for determining a concentration of a constituent gas in a gas stream using pressure measurements are disclosed. A method may include a vaporizer receiving a carrier gas and a source material, and vaporizing the source material in the vaporizer to produce a gas stream including the carrier gas and the constituent vapor. Then, a pressure of a chamber of the vaporizer is obtained, a mass flow rate of the gas stream is measured, and a temperature of the chamber of the vaporizer is measured. A constituent-vapor-concentration signal indicative of the concentration the constituent vapor in the gas stream is then generated. The mass flow rate of the constituent vapor may be determined using the concentration of the constituent vapor, and the mass flow rate of the constituent vapor may then be controlled using the determined mass flow rate of the constituent vapor.

System and method for determining a concentration of a constituent gas in a gas stream using pressure measurements

Mass flow control systems and methods for controlling the mass flow rate of a gas through a primary conduit are disclosed. One mass flow control system includes a primary conduit for directing a flow of a gas and an adjustment system configured to divert a portion of the gas from the primary conduit to a secondary conduit and provide an adjustment signal that changes when a composition of the gas changes. A mass flow controller is operatively coupled to the primary conduit to control a primary flow rate of the gas. The mass flow controller includes a valve to control the primary flow rate of the gas and a control loop configured to receive the adjustment signal and control the valve to provide the primary flow rate of the gas at a set point.

Gas insensitive mass flow control systems and methods

Systems and method for detecting a concentration of a gas in a gas stream are disclosed. A method includes receiving a gas stream including a carrier gas and a processing gas. Bridge signals of a mass flow sensor are used to produce a processing-gas concentration signal and a gas-stream mass flow rate signal. The gas stream is controlled so a mass flow rate of the processing gas equals a processing-gas-setpoint signal. In some variations, the processing-gas-concentration signal is produced using an upstream temperature of the gas stream and a bridge-derived temperature.

Mass flow controller and method for controlling a mass flow rate of a gas in a gas stream

Systems and method for detecting a concentration of a gas in a gas stream are disclosed. A method includes receiving a gas stream including a carrier gas and a processing gas. Bridge voltages of a mass flow sensor are used to produce a processing-gas concentration signal and a gas-stream mass flow rate signal. The gas stream is controlled so a mass flow rate of the processing gas equals a processing-gas-setpoint signal. In some variations, the processing-gas-concentration signal is produced using an upstream temperature of the gas stream and a bridge-derived temperature. In other variations, the processing-gas-concentration signal is produced using a top voltage of the mass flow sensor and the gas-stream mass flow rate signal.

System and method for detecting concentration of a gas in a gas stream

Gas insensitive systems and methods for controlling the mass flow rate of a gas through a primary conduit are disclosed. The method includes producing, in a secondary conduit, an assessment flow that has a changing pressure; calculating a first measure of a flow rate of the assessment flow based upon a rate-of-change of the pressure of the assessment flow; and measuring the assessment flow with a mass flow meter that is affected by the composition of the gas to produce a second measure of the assessment flow. An adjustment signal is generated based upon a difference between the first measure and the second measure, and a gas-corrected flow signal is generated by adjusting a measured-flow signal of a mass flow controller with the adjustment signal. The gas-corrected flow signal is used by the mass flow controller to control a flow rate of the gas through the primary conduit.

Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnostics are disclosed. A mass flow controller includes a differential voltage processing component to provide a first output that is indicative of a differential voltage between second and fourth nodes of a bridge circuit and a top voltage processing component provides a second output indicative of a top voltage between the first node and the third node of the bridge circuit. Top-and-differential voltage reference data stored in non-volatile memory defines a characteristic curve relating top voltage reference values to corresponding differential voltage reference values. A sensor analysis component obtains a top and differential voltage pair and assesses whether the top and differential voltage pair deviates from the characteristic curve to determine whether the sensing element circuit has changed since the top-and-differential voltage reference data was stored in the non-volatile memory.

On-tool mass flow controller diagnostic systems and methods

A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

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Wellington, CO, United States of America

Patrick Albright