CROSS-REFERENCE

This application is a national phase of an international application, PCT/JP2018/037416, filed on Oct. 5, 2018, which claims the benefit of Japanese Application No. 2017-229481 filed on Nov. 29, 2017.

TECHNICAL FIELD

The present invention relates to technology for diagnosing an abnormality of a fluid supply line having a plurality of fluid control devices.

BACKGROUND ART

A fluid control device such as an automatic valve is used in a fluid supply line that supplies a process fluid used in a semiconductor manufacturing process.

In recent years, a semiconductor manufacturing process such as atomic layer deposition (ALD) is advanced, and a fluid supply line capable of finely controlling a process fluid more than ever is demanded. In order to meet the demand of the advanced semiconductor manufacturing process, for example, a fluid control device capable of monitoring a state of a valve more precisely is proposed.

In this regard, Patent Literature 1 proposes a valve that includes a body provided with a first flow passage and a second flow passage and a valve element causing the first flow passage and the second flow passage to communicate with or block each other. The body has a base portion that has a first plane located at the side of the valve element and a second plane located at the side opposite to the first plane, a first connection portion that has a third plane forming a step portion with the second plane, and a second connection portion that has a fourth plane forming a step portion with the first plane. The first flow passage has a 1-1 flow passage and a 1-2 flow passage. A 1-1 port of the 1-1 flow passage is opened to the third plane, a 1-3 port of the 1-2 flow passage communicates with a 1-2 port of the 1-1 flow passage and is opened to the valve element, a 1-4 port of the 1-2 flow passage is opened to the fourth plane, and the first flow passage and the second flow passage can communicate with each other via the 1-3 port. The first connection portion is connected to a portion corresponding to the second connection portion in a body of another valve, and the 1-1 flow passage and a flow passage corresponding to the 1-2 flow passage in the body of another valve communicate with each other.

Further, as technology for diagnosing an abnormality of the valve, Patent Literature 2 proposes an orifice clogging detection method in a pressure type flow rate control device. The flow rate control device includes a control valve, an orifice, a pressure detector for detecting an upstream side pressure between them, and a flow rate setting circuit. The flow rate control device holds the upstream side pressure at about twice or more a downstream side pressure, calculates a flow rate of the downstream side, and controls opening/closing of the control valve, on the basis of a difference signal between the calculated flow rate and a setting flow rate. The orifice clogging detection method includes a first step of holding the setting flow rate at a high setting flow rate of a 100% flow rate, a second step of switching the high setting flow rate to a low setting flow rate of a 0% flow rate, holding the low setting flow rate, and measuring the upstream side pressure to obtain pressure attenuation data, a third step of comparing the pressure attenuation data and reference pressure attenuation data measured when the orifice has no clogging under the same conditions, and a fourth step of reporting clogging when the pressure attenuation data after a predetermined time elapses from switching to the low setting flow rate is separated from the reference pressure attenuation data by a predetermined degree or more.

CITATION LIST

Patent Literature

Patent Literature 1: JP 2016-223533 APatent Literature 2: Japanese Patent No. 3546153

SUMMARY OF INVENTION

Technical Problem

However, in the fluid supply line including the plurality of fluid control devices, each fluid control device is affected by an opening/closing operation of another fluid control device, a flow rate change, or the like. For this reason, accuracy required for the advanced semiconductor manufacturing process cannot be secured only by diagnosing the presence or absence of an operation abnormality independently for each fluid control device.

Further, if electric wiring or an air tube is complicated due to high functionality of the fluid control device, the complicated electric wiring causes noise or delay in the transmission speed of an instruction signal, and an increase in the inner volume of the air tube decreases an opening/closing speed of the fluid control device or causes an error in the opening/closing speed of each fluid control device. This disturbs accurate and precise diagnosis even when the presence or absence of an abnormality is diagnosed.

Accordingly, an object of the present invention is to diagnose an abnormality of a fluid control device from an operation of an entire fluid supply line including a plurality of fluid control devices.

Solution to Problem

In order to achieve the above object, an abnormality diagnosis method of a fluid supply line according to the present invention is an abnormality diagnosis method of a fluid supply line including a plurality of fluid control devices communicating with each other fluid-tightly. The fluid supply line includes a flow rate control device that is connected to a mechanism outside the fluid supply line by a first connection mechanism and has a valve in the flow rate control device and a pressure detection mechanism that detects a pressure in a flow passage, a first valve that is connected to the mechanism outside the fluid supply line by a second connection mechanism branched from the first connection mechanism and is disposed on the upstream side of the flow rate control device, and a second valve that is connected to the mechanism outside the fluid supply line by the second connection mechanism branched from the first connection mechanism and is disposed on the downstream side of the flow rate control device. The abnormality diagnosis method includes: a valve operation step of opening/closing any one or more of the valve in the flow rate control device, the first valve, and the second valve; a pressure adjustment step of setting a part or all of flow passages leading from the first valve to the second valve via the flow rate control device to a vacuum state or a pressurization state; a pressure detection step of acquiring temporal pressure characteristics in the flow passage of the flow rate control device by the pressure detection mechanism; and an abnormality determination step of comparing pressure characteristics at the time of abnormality diagnosis acquired by the pressure detection mechanism and pressure characteristics at the time of normality measured in advance under the same conditions, and determining whether or not there is an abnormality.

Further, the valve operation step may be configured by a first step of opening the first valve, a second step of closing the valve in the flow rate control device, a third step of opening the second valve, and a fifth step of closing the second valve from a state where the inside of a flow passage leading from a valve portion of the valve in the flow rate control device to a valve portion of the second valve is evacuated, the pressure adjustment step may be configured by a fourth step of setting the inside of the flow passage leading from the valve portion of the valve in the flow rate control device to the valve portion of the second valve to a vacuum state, after the third step, and the pressure detection step may be configured by a sixth step of acquiring temporal pressure characteristics in the flow passage leading from the valve portion of the valve in the flow rate control device to the valve portion of the second valve by the pressure detection mechanism, after executing the fifth step.

Further, the valve operation step may be configured by a first step of closing the first valve, a second step of opening the valve in the flow rate control device, a third step of opening the second valve, and a fifth step of closing the second valve from a state where the inside of a flow passage leading from a valve portion of the first valve to a valve portion of the second valve via the flow passage of the flow rate control device is evacuated, the pressure adjustment step may be configured by a fourth step of setting the inside of the flow passage leading from the valve portion of the first valve to the valve portion of the second valve via the flow passage of the flow rate control device to a vacuum state, after the third step, and the pressure detection step may be configured by a sixth step of acquiring temporal pressure characteristics in the flow passage leading from the valve portion of the first valve to the valve portion of the second valve via the flow passage of the flow rate control device by the pressure detection mechanism, after executing the fifth step.

Further, the valve operation step may be configured by a first step of opening the first valve, a second step of opening the valve in the flow rate control device, a third step of closing the second valve, and a fifth step of closing the valve in the flow rate control device from a state where the inside of a flow passage leading from a valve portion of the first valve to a valve portion of the second valve via the flow passage of the flow rate control device is pressurized, the pressure adjustment step may be configured by a fourth step of setting the inside of the flow passage leading from the valve portion of the first valve to the valve portion of the second valve via the flow passage of the flow rate control device to a pressurization state, after the third step, and the pressure detection step may configure a sixth step of acquiring temporal pressure characteristics in the flow passage leading from the valve portion of the first valve to the valve portion of the second valve via the flow passage of the flow rate control device by the pressure detection mechanism, after executing the fifth step.

Further, the valve operation step may be configured by a first step of opening the first valve, a second step of opening the valve in the flow rate control device, a third step of closing the second valve, a fifth step of closing the valve in the flow rate control device from a state where the inside of a flow passage leading from a valve portion of the valve in the flow rate control device to a valve portion of the second valve is pressurized, and a sixth step of opening the second valve after closing the valve in the flow rate control device, the pressure adjustment step may be configured by a fourth step of setting the inside of the flow passage leading from the valve portion of the valve in the flow rate control device to the valve portion of the second valve to a pressurization state, after the third step, and the pressure detection step may configure a seventh step of acquiring temporal pressure characteristics in the flow passage leading from the valve portion of the valve in the flow rate control device to the valve portion of the second valve by the pressure detection mechanism, after executing the sixth step.

Further, each of the first connection mechanism and the second connection mechanism may be a drive pressure supply path that supplies a drive fluid used for driving the fluid control device from the mechanism outside the fluid supply line.

Further, each of the first connection mechanism and the second connection mechanism may be electric wiring that enables communication between the mechanism outside the fluid supply line and the fluid control device.

Further, a plurality of fluid supply lines may be arranged in parallel to configure a gas unit, and the first connection mechanism may branch for each of the plurality of fluid supply lines in the vicinity of the gas unit, and may be connected to each predetermined fluid control device on the plurality of fluid supply lines.

Further, the flow rate control device may be a flow rate range variable type flow rate control device. The flow rate range variable type flow rate control device may have at least a fluid passage for a small flow rate and a fluid passage for a large flow rate as a fluid passage to a flow rate detection unit of the flow rate control device. The flow rate range variable type flow rate control device may circulate a fluid in a small flow rate region to the flow rate detection unit through the fluid passage for the small flow rate and switch a detection level of a flow rate control unit to a detection level suitable for the detection of the flow rate of the small flow rate region, and may circulate a fluid in a large flow rate region to the flow rate detection unit through the fluid passage for the large flow rate and switch the detection level of the flow rate control unit to a detection level suitable for the detection of the flow rate of the large flow rate region, thereby switching the fluid in each of the large flow rate region and the small flow rate region to control the flow rate.

Further, the flow rate control device may be a differential pressure type flow rate control device. The differential pressure type flow rate control device may have a control valve including a valve drive unit, an orifice provided on the downstream side of the control valve, a detector for a fluid pressure of the upstream side of the orifice, a detector for a fluid pressure of the downstream side of the orifice, a detector for a fluid temperature of the upstream side of the orifice, and a control arithmetic circuit including a flow rate comparison circuit that calculates a fluid flow rate using a detection pressure and a detection temperature from each of the detectors and calculates a difference between the calculated flow rate and a setting flow rate.

Advantageous Effects of Invention

According to the present invention, it is possible to diagnose an abnormality of a fluid control device from an operation of an entire fluid supply line including a plurality of fluid control devices.

