US 12,334,355 B2
Pressure control device
Kaoru Hirata, Osaka (JP); Kouji Nishino, Osaka (JP); Katsuyuki Sugita, Osaka (JP); Shinya Ogawa, Osaka (JP); and Keisuke Ideguchi, Osaka (JP)
Assigned to FUJIKIN INCORPORATED, Osaka (JP)
Appl. No. 17/785,352
Filed by FUJIKIN INCORPORATED, Osaka (JP)
PCT Filed Dec. 3, 2020, PCT No. PCT/JP2020/045060
§ 371(c)(1), (2) Date Jun. 14, 2022,
PCT Pub. No. WO2021/131577, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 2019-235252 (JP), filed on Dec. 25, 2019.
Prior Publication US 2023/0011244 A1, Jan. 12, 2023
Int. Cl. G01F 1/34 (2006.01); G05D 16/20 (2006.01); H01L 21/3065 (2006.01); H01L 21/66 (2006.01); G01F 1/48 (2006.01)
CPC H01L 21/3065 (2013.01) [G05D 16/20 (2013.01); H01L 22/26 (2013.01); G01F 1/34 (2013.01); G01F 1/48 (2013.01); Y10T 137/7759 (2015.04); Y10T 137/7761 (2015.04)] 6 Claims
OG exemplary drawing
 
1. A pressure control device comprising:
a pressure control valve provided in a flow path;
a flow resistance for restricting a gas flow provided downstream of the pressure control valve;
a first pressure sensor for measuring a gas pressure of the flow path between the pressure control valve and the flow resistance;
a second pressure sensor for measuring a gas pressure of the flow path downstream of the flow resistance; and
an arithmetic control circuit connected to the first pressure sensor and the second pressure sensor,
wherein the arithmetic control circuit is configured to control a gas pressure downstream of the flow resistance by adjusting an opening degree of the pressure control valve based on an output of the second pressure sensor regardless of an output of the first pressure sensor and calculate a flow rate of the gas flowing downstream from the flow resistance based on the outputs of the first pressure sensor and the second pressure sensor,
wherein the flow resistance is a laminar flow element comprising a columnar member and a capillary structure provided in a hole penetrating an axis direction of the columnar member, and
the columnar member has a recess on its end surface for accommodating an enlarged diameter portion of the capillary structure, and a resin gasket is provided between a bottom surface of the recess of the columnar member and a bottom surface of the enlarged diameter portion of the capillary structure.