Valve device, fluid control system, fluid control method, semiconductor manufacturing system, and semiconductor manufacturing method

1. A valve device comprising:

a valve body that forms a first flow path and a second flow path;

an inner disc that includes:

an inner annular part disposed around an opening of the first flow path;

an outer annular part disposed on an outer peripheral side of the inner annular part; and

a connecting part that:

comprises a plurality of openings that communicates with the second flow path, and

connects the inner annular part and the outer annular part;

a valve seat disposed on the inner annular part;

a diaphragm that:

comprises a peripheral edge part that contacts the outer annular part, and

moves between an open position and a closed position, wherein

in the open position, the diaphragm does not contact the valve seat, and the first flow path and the second flow path are continuous, and

in the closed position, the diaphragm contacts the valve seat, and the first flow path and the second flow path are discontinuous;

a pressing adapter that sandwiches the peripheral edge part with the outer annular part and that contacts the peripheral edge part; and

a disc seal that is disposed between the inner annular part and the valve body and that is held in a disc seal groove, wherein

the outer annular part comprises:

a diaphragm contact surface that contacts the diaphragm; and

a body contact surface that contacts a surface of the valve body, wherein

an outermost position of the diaphragm contact surface is on an outer side of an outermost position of the body contact surface, and

the disc seal groove is disposed on a valve body side of the inner annular part.

2. The valve device according to claim 1 , wherein the diaphragm is dome-shaped with a curved surface that has no inflection point in the open position.

3. The valve device according to claim 1 , wherein:

the inner annular part includes a valve seat groove disposed on a diaphragm side of the inner annular part, and

the valve seat is:

held in the valve seat groove,

made of a same material as the disc seal, and

a same shape as the disc seal.

4. The valve device according to claim 1 , wherein the inner annular part:

has a tubular shape longer than the outer annular part in a direction of extension of a center line of the inner disc, and

communicates:

with the first flow path on an inner side of the inner annular part, and

with the second flow path on an outer side of the inner annular part.

5. A fluid control system comprising a plurality of fluid devices that is arranged from an upstream side toward a downstream side and that includes the valve device of claim 1 .

6. A valve device comprising:

a valve body that forms a first flow path and a second flow path;

an inner disc that includes:

an inner annular part disposed around an opening of the first flow path;

an outer annular part disposed on an outer peripheral side of the inner annular part; and

a connecting part that:

comprises a plurality of openings that communicates with the second flow path, and

connects the inner annular part and the outer annular part;

a valve seat disposed on the inner annular part;

a diaphragm that:

comprises a peripheral edge part that contacts the outer annular part, and

moves between an open position and a closed position, wherein

in the open position, the diaphragm does not contact the valve seat, and the first flow path and the second flow path are continuous, and

in the closed position, the diaphragm contacts the valve seat, and the first flow path and the second flow path are discontinuous;

a pressing adapter that sandwiches the peripheral edge part with the outer annular part and that contacts the peripheral edge part; and

a disc seal that is disposed between the inner annular part and the valve body and that is held in a disc seal groove, wherein

the outer annular part comprises:

a diaphragm side surface; and

a valve body side surface that is opposite the diaphragm side surface, wherein

a radius of a circle formed by an outer edge of the diaphragm side surface is greater than a radius of a circle formed by an outer edge of the valve body side surface, and

the disc seal groove is disposed on a valve body side of the inner annular part.

7. A flow control method for adjusting a flow rate of a fluid using the valve device of claim 1 .

8. A semiconductor manufacturing system comprising the valve device of claim 1 for control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.

9. A semiconductor manufacturing method comprising a step of using the valve device of claim 1 for flow control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.

10. A fluid control system comprising a plurality of fluid devices that is arranged from an upstream side toward a downstream side and that includes the valve device of claim 6 .

11. A flow control method for adjusting a flow rate of a fluid using the valve device of claim 6 .

12. A semiconductor manufacturing system comprising the valve device of claim 6 for control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.

13. A semiconductor manufacturing method comprising a step of using the valve device of claim 6 for flow control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.