Flow rate control device

Abstract

A flow rate control device (100) is provided with a pressure control valve (6) that is provided to a flow path; a flow rate control valve (8) that is provided to the downstream side of the pressure control valve; and a first pressure sensor (3) that measures pressure at the downstream side of the pressure control valve and the upstream side of the flow rate control valve. The flow rate control valve has a valve body (13) that is seated on / separated from a valve seat (12); a piezoelectric element (10b) for moving the valve body so as to be seated on / separated from the valve seat; and a strain sensor (20) that is installed on a side surface of the piezoelectric element and is configured to control the pressure control valve (6) on the basis of a signal outputted from the first pressure sensor (3) and control the driving of the piezoelectric element of the flow rate control valve (8) on the basis of a signal outputted from the strain sensor (20).

Description

technical field [0001] The present invention relates to a flow control device, in particular to a flow control device suitable for semiconductor manufacturing equipment or chemical manufacturing equipment. Background technique [0002] In semiconductor manufacturing equipment or chemical plants, various types of flowmeters or flow control devices are used to control the flow of fluids such as material gases and etching gases. Among them, pressure type flow control devices are widely used because they can control the flow rates of various fluids with high precision through a relatively simple mechanism combining a control valve and a throttle (for example, an orifice) (for example, Patent Document 1). [0003] As a control valve of a pressure-type flow control device, it is widely used in consideration of high corrosion resistance, less dust generation, good gas replacement, fast opening and closing speed, and the ability to quickly and reliably seal the fluid passage when cl...

AI Technical Summary

Problems solved by technology

However, in this case, the manufacturing cost of the device increases, which may impair the advantage of being able to control the flow rate with high precision by a relatively simple mechanism of the pressure type flow control device.

Therefore, in the conventional flow control device, there is an obstacle that it is difficult to perform both the pulse flow control and the flow control of the continuous flow appropriately.

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