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AssigneesFujikin Incorporated, Tadahiro Ohmi, Tokyo Electron Limited
InventorsTadahiro Ohmi, Tetu Kagazume, Kazuhiko Sugiyama, Ryousuke Dohi, Tomio Uno, Kouji Nishino, Hiroyuki Fukuda, Nobukazu Ikeda, Michio Yamaji
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A pressure-type flow rate control apparatus for use especially in the gas supply system in semiconductor manufacturing facilities. The flow control apparatus is provided with a bore-variable orifice, which permits easy switching of the fluid flow rate control range as well as size reduction of the pressure-type flow control apparatus, and offers other advantages including improved gas replaceability, prevention of dust formation, and reduced manufacturing costs of the flow control system. The apparatus comprises an orifice, a control valve provided on the upstream side of the orifice, a pressure detector provided between the control valve and the orifice, and a control unit to calculate a fluid flow rate Q on the basis of a pressure P1 detected by the pressure detector with the equation Q=KP1 (K=constant) and to output in a drive for the control valve the difference between the set flow rate signal Qs and the calculated flow rate signal Q as control signal Qy, wherein the pressure P1 on the upstream side of the orifice is regulated by actuating the control valve for controlling the flow rate of the fluid downstream of the orifice with the ratio P2/P1 between the pressure P1 on the upstream side of the orifice and the downstream pressure P2 maintained at not higher than the ratio of the critical pressure of the controlled fluid, characterized in that a direct touch type metal diaphragm valve unit functions as the orifice and that the ring-shaped gap between the valve seat and the diaphragm serves a variable orifice wherein the gap is adjusted by the orifice drive.
A pressure-type fluid flow rate control apparatus comprising an orifice, a control valve provided on an upstream side of the orifice, a pressure detector provided between the control valve and the orifice, and a control unit which calculates a fluid flow rate on the basis of pressure P1 detected by the pressure detector with the equation Qc=KP1 (K=constant) and outputs, in a drive for the control valve, the difference between a set flow rate signal Qs and the calculated flow rate signal Qc as a control signal Qy, wherein the pressure P1 on the upstream side of the orifice is regulated by actuating the control valve for controlling the flow rate Q of the fluid downstream of the orifice, so that the ratio P2/P1 between the pressure P1 on the upstream side of the orifice and the downstream pressure P2 is maintained at not higher than the critical pressure ratio of the controlled fluid, characterized in that a direct touch type metal diaphragm valve unit functions as the orifice and that a ring-shaped gap between a valve seat and a diaphragm serves as a variable orifice, and a pulse motor type drive for regulating said ring-shaped gap.
A pressure-type fluid flow rate control apparatus comprising an orifice, a control valve provided on the upstream side of the orifice, a pressure detector provided between the control valve and the orifice, and a control unit which calculates a fluid flow rate on the basis of pressure P1 detected by the pressure detector with the equation Qc=KP1 (K=constant) and outputs, in a drive for the control valve, the difference between a set flow rate signal Qs and the calculated flow rate signal Qc as a control signal Qy, wherein the pressure P1 on the upstream side of the orifice is regulated by actuating the control valve for controlling the flow rate Q of the fluid downstream of the orifice, so that the ratio P2/P1 between the pressure P1 on the upstream side of the orifice and the downstream pressure P2 is maintained at not higher than the critical pressure ratio of the controlled fluid, characterized in that a direct touch type metal diaphragm valve unit functions as the orifice and that a ring-shaped gap between a valve seat and a diaphragm serves as a variable orifice and a piezoelectric element type drive for regulating said ring-shaped gap.
A pressure-type flow rate control apparatus for controlling a fluid, said apparatus comprising:
Dependencies are inferred from the claim text.