Gas supply device capable of measuring flow rate, flow meter, and flow measurement method

Abstract

The present invention provides a gas supply device capable of measuring the flow rate, comprising: a flow controller, which controls the flow rate of the gas flowing; a first cutoff valve, which is arranged downstream of the flow controller; a second cutoff valve, which is set The first flow path communicating with the downstream side of the first block valve; the second flow path branched from the first flow path; the third block valve provided in the second flow path; pressure detection A device that detects the pressure in the flow path surrounded by the first, second and third block valves; a temperature detector that detects the flow path surrounded by the first, second and third block valves temperature inside; a volume measurement box, which is connected to the downstream of the third block valve and has a known volume; ear's law to obtain the flow path volume surrounded by the first, second, and third blocking valves, and calculate the flow rate using the flow path volume, the detection values ​​of the pressure detector, and the temperature detector Controller flow.

Description

technical field [0001] The present invention relates to a gas supply device capable of measuring a flow rate, a flow meter, and a flow measurement method. Background technique [0002] Conventionally, in a semiconductor manufacturing process or the like, a gas supply device provided with a flow controller, a valve, or the like has been used in order to supply processing gas or the like at a predetermined flow rate. This kind of flow controller needs to measure the flow and check the control accuracy because of the demand for high-precision flow control. As a method of measuring the flow rate, the ROR (rate of rise) method (also called the buildup method) for measuring the flow rate based on the pressure rise rate is widely known (Patent Documents 1, 2, etc.). [0003] The ROR method is to make the gas whose flow rate is controlled by a flow controller flow in a predetermined volume (V) existing in the flow path, and use Q=( ΔP / Δt) × V / RT relationship (R is the gas constant...

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Problems solved by technology

[0009] However, in the conventional ROR method, the volume (V) is measured with a flow controller, and the measured volume (V) may contain errors because the flow rate controlled by the flow controller used for the measurement contains errors.

[0010] In addition, there is a need for space-saving gas supply equipment, but installing an accessory device for flow measurement will hinder space-saving

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