Flow Rate Control Apparatus

Abstract

A flow rate control apparatus includes a base section, wherein the base section is composed of a plurality of stacked metal plates. The flow rate control apparatus further includes a pressure control section, which regulates pressure of a pressure fluid (gas) that flows through a first passage in the base section, a pressure sensor that detects pressure of the pressure fluid flowing through a second passage, and a flow passage-switching section, including first to third orifices, for throttling the fluid pressure-regulated by the pressure control section so as to have a predetermined flow rate, and which has first to third ON/OFF valves for switching fourth to sixth passages for respectively directing the pressure fluid toward a pressure fluid output port.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view taken in the axial direction illustrating a flow rate control apparatus according to a first embodiment of the present invention;

FIG. 2 is a circuit diagram of the flow rate control apparatus shown in FIG. 1;

FIG. 3 is a perspective view illustrating a base section that makes up a portion of the flow rate control apparatus shown in FIG. 1;

FIG. 4 is an exploded perspective view illustrating the base section shown in FIG. 3;

FIG. 5 is a magnified longitudinal sectional view illustrating a flow passage-switching section that makes up a portion of the flow rate control apparatus shown in FIG. 1;

FIG. 6 is a magnified longitudinal sectional view illustrating a state in which a valve plug of the flow passage-switching section shown in FIG. 5 is displaced;

FIG. 7 is a longitudinal sectional view illustrating another embodiment, in which a linear solenoid valve is provided in the pressure control section;

FIG. 8 is a longitudinal sectional view illustrating another embodiment, in which a linear solenoid valve is provided in the flow passage-switching section;

FIG. 9 is a longitudinal sectional view illustrating another embodiment, in which linear solenoid valves are provided in the pressure control section and the flow passage-switching section, respectively;

FIG. 10 is a block diagram illustrating a state in which the flow rate control apparatus shown in FIG. 1 is connected to a chamber of a semiconductor manufacturing apparatus;

FIG. 11 is a block diagram illustrating a state in which the pressure fluid output port of the flow rate control apparatus shown in FIG. 1 branches into a plurality of ports to be connected to a chamber;

FIG. 12 is a circuit diagram of the flow rate control apparatus shown in FIG. 11;

FIG. 13 is an exploded perspective view illustrating a base section that makes up a portion of the flow rate control apparatus shown in FIG. 11;

FIG. 14 is a circuit diagram of a flow rate control apparatus according to a second embodiment of the present invention;

FIG. 15 is a circuit diagram in which the pressure fluid output port of the flow rate control apparatus shown in FIG. 14 branches into a plurality of ports;

FIG. 16 is a longitudinal sectional view taken in the axial direction illustrating a flow rate control apparatus according to a third embodiment of the present invention;

FIG. 17 is a longitudinal sectional view illustrating a modified embodiment of the flow rate control apparatus shown in FIG. 16;

FIG. 18 is a longitudinal sectional view taken in the axial direction illustrating a flow rate control apparatus according to a fourth embodiment of the present invention;

FIG. 19 is an exploded perspective view illustrating a base section of the flow rate control apparatus shown in FIG. 18;

FIG. 20 is a partial magnified longitudinal sectional view illustrating a differential pressure sensor of the flow rate control apparatus shown in FIG. 18;

FIG. 21 is a schematic structural view illustrating principles of operation of the differential pressure sensor shown in FIG. 20;

FIG. 22 is a longitudinal sectional view taken in the axial direction illustrating a flow rate control apparatus according to a fifth embodiment of the present invention;

FIG. 23 is an exploded perspective view illustrating a base section of the flow rate control apparatus shown in FIG. 22;

FIG. 24 is, in partial cutout, a magnified view illustrating a rectifying mechanism provided in a third plate;

FIG. 25 is a schematic structural view illustrating functions that are obtained when a rectifying mechanism is not provided; and

FIG. 26 is a schematic structural view illustrating functions that are obtained when the rectifying mechanism is provided.

Claims

1. A flow rate control apparatus comprising: a base section having pressure fluid passages composed of penetrating or non-penetrating holes, a pressure fluid input port, a pressure fluid output port, and a pressure sensor port, said base section being formed by integrally stacking a plurality of plates and a diaphragm that functions as a valve plug disposed between said plates;a pressure control section assembled onto a side surface of said base section, which regulates a pressure of a pressure fluid that flows through said passages;a pressure sensor assembled onto said side surface of said base section, which communicates with said pressure sensor port and which detects said pressure of said pressure fluid that flows through said passages; anda flow passage-switching section assembled onto said side surface of said base section, which switches said passages that communicate with said pressure control section and said pressure fluid output port so that said pressure fluid that is pressure-regulated by said pressure control section, flows toward said pressure fluid output port.

2. The flow rate control apparatus according to claim 1, wherein said pressure control section comprises a piezoelectric/electrostrictive actuator having a piezoelectric/electrostrictive element, said base section being formed with a seat section for seating said valve plug thereon, and wherein a spacing distance between said valve plug and said seat section is controlled under a driving action of said piezoelectric/electrostrictive actuator.

3. The flow rate control apparatus according to claim 1, wherein said pressure control section comprises a linear solenoid valve for displacing a valve rod by means of an electromagnetic force generated in proportion to an amount of electric power applied to a solenoid section, said base section being formed with a seat section for seating said valve plug thereon, and wherein a spacing distance between said valve plug and said seat section is controlled under a driving action of said linear solenoid valve.

4. The flow rate control apparatus according to claim 1, wherein said flow passage-switching section comprises an ON/OFF valve having a piston that is displaceable on the basis of a pilot pressure supplied under an energizing/deenergizing action of a solenoid-operated valve, and a piston rod that is displaceable integrally with said piston, said base section being formed with a seat section for seating said valve plug thereon, and wherein said passage through which said pressure fluid flows is opened and closed in accordance with an ON/OFF operation of said ON/OFF valve.

5. The flow rate control apparatus according to claim 1, wherein said base section includes said pressure fluid output port or a plurality of pressure fluid output ports.

6. A flow rate control apparatus comprising: a base section having pressure fluid passages composed of penetrating or non-penetrating holes, a pressure fluid input port, a pressure fluid output port, and a pressure sensor port, said base section being formed by integrally stacking a plurality of plates and a diaphragm that functions as a valve plug disposed between said plates;a pressure control section assembled onto a side surface of said base section, which regulates a pressure of a pressure fluid that flows through said passages;a pressure sensor assembled onto said side surface of said base section, which communicates with said pressure sensor port and which detects said pressure of said pressure fluid that flows through said passages; anda flow passage-switching control section assembled onto said side surface of said base section, which includes control valves for controlling said pressure fluid that is pressure-regulated by said pressure control section so that said pressure fluid has a predetermined flow rate, other pressure sensors for detecting pressures of said pressure fluid that passes through said control valves, and throttle mechanisms for throttling said pressure fluid that is pressure-regulated by said control valves, so that said pressure fluid has a predetermined flow rate, wherein said flow passage-switching control section switches and controls said passages that communicate with said pressure fluid output port.

7. The flow rate control apparatus according to claim 6, wherein each of said control valves comprises a linear solenoid valve for displacing a valve rod by means of an electromagnetic force generated in proportion to an amount of electric power applied to a solenoid section.

8. The flow rate control apparatus according to claim 6, wherein each of said control valves comprises a pair of solenoid-operated valves functioning as gas supply and discharge valves.

9. The flow rate control apparatus according to claim 6, wherein: each of said control valves comprises a thermal expansion type actuator; andsaid thermal expansion type actuator comprises a cavity, which encloses a liquid therein, disposed on an upper side of said diaphragm, so that said diaphragm is flexibly bent when said liquid is expanded by heating said liquid with a heater.

10. The flow rate control apparatus according to claim 9, wherein said liquid is composed of a liquid having an insulating property and an inert property.

11. A flow rate control apparatus comprising: a base section having pressure fluid passages composed of penetrating or non-penetrating holes, a pressure fluid input port, a pressure fluid output port, and a pressure sensor port, said base section being formed by integrally stacking a plurality of plates and a diaphragm that functions as a valve plug disposed between said plates;a pressure control section assembled onto a side surface of said base section, which regulates a pressure of a pressure fluid that flows through said passages;a flow rate sensor assembled onto said side surface of said base section, which detects a flow rate of said pressure fluid that flows through said passages,wherein an intermediate plate, which is included in the plurality of plates making up said base section, is provided with rectifying mechanisms therein composed of a plurality of small holes having identical and different diameters, for stabilizing a flow of said pressure fluid that flows through said passages.