TW201841088A - Diagnostic system, diagnostic method, storage medium, and flow rate controller - Google Patents

Abstract

The present invention intends to more accurately diagnose a function of a flow rate sensor regardless of a variation in measurement ambient condition. The present invention includes: a flow rate sensor for measuring the flow rate of fluid; a correction part adapted to measure an output value of the flow rate sensor or a value related to the output value (hereinafter collectively referred to as an "output-related value"), relates the measured output-related value and a corresponding measurement ambient condition to each other, and in accordance with the measurement ambient condition in measurement data, correct the output-related value or a reference value that is predetermined in order to determine whether the output-related value is normal; and a diagnostic part adapted to compare the output-related value and the reference value on the basis of a correction result by the correction part and correct the function of the flow rate sensor.

Description

Diagnostic system, diagnostic method, storage medium, and flow control device

The present invention relates to a diagnostic system, a diagnostic method, a storage medium, and a flow control device.

The diagnostic mechanism used in the conventionally disclosed flow rate control device (mass flow controller) includes a flow sensor and a valve as disclosed in Patent Document 1, and the flow sensor has a pressure difference in a flow path in which a fluid flows. The resistance body and the pressure sensors respectively disposed on the upstream side and the downstream side of the resistance body open and close the flow path on the upstream side of the flow rate sensor. The flow path is decompressed while the flow path is closed by the valve, and based on the output value obtained from the flow rate sensor or the value related to the output value, that is, the output correlation value (diagnostic parameter) is set in advance. The reference values are different to diagnose the function of the flow sensor.

Here, the output correlation value is more specifically described, and the output correlation value is obtained by decompressing the flow path in a state where the flow path is closed by the valve, and based on the pressure difference between the pressures P1 and P2 measured by the two pressure sensors. The mass flow rate Q calculated by equation (1).

Further, P1 is a pressure value of the upstream side pressure sensor, P2 is a pressure value of the downstream side pressure sensor, and X is a coefficient that varies depending on the kind of the gas.

Next, the mass flow integral value n is calculated using the equation (2) in which the mass flow rate Q is time-integrated in a specified time during which the pressure measured by the upstream side pressure sensor changes with time. Further, in Fig. 5, the sum of the mass flow rates Q of the portions indicated by oblique lines between a-b indicates the mass flow integral value n.

Further, the mass flow integral value n can also be expressed as shown by the equation (3) using the state equation of the gas.

In addition, V is the volume value for diagnosis, P1 _START is the pressure measured by the upstream side pressure sensor at the starting point of the specified time, and P1 _END is the pressure measured by the upstream side pressure sensor at the end of the specified time. .

Further, the volume value V represented by the formula (4) derived from the equations (2) and (3) becomes an output correlation value.

Further, n is a molar number (a value obtained by integrating the mass per unit time (mass flow rate Q) calculated using the formula (1) with time, that is, a mass flow integral value n), and R is a gas determined according to the kind of gas The constant, T is the temperature measured by the temperature sensor, which is considered constant here, and ΔP1 is the pressure difference of the pressure measured by the upstream side pressure sensor at the start and end points of the specified time.

Here, although the pressure difference and temperature between the start point and the end point of the specified time are included in the equations (3) to (4), the above values may be considered in consideration of the pressure and temperature between the specified times. The amount of change in pressure and the amount of change in temperature.

However, the output correlation value represented by the equation (4) includes temperature and pressure, and these values become the cause of the error in the volume value V. In other words, when the pressure that changes with time is continuously measured at a predetermined time by the pressure sensor, the secondary pressure generated by the piping, various equipment, and the like connected to the downstream side of the flow sensor occurs over time. The change, the secondary pressure change affects the pressure measurement of the pressure sensor, and cannot be measured under the same measurement peripheral conditions, and the secondary pressure change causes an error in the volume value V. In addition, the temperature also changes with time, and the change of the temperature also affects the pressure measurement of the pressure sensor, and cannot be measured under the same measurement peripheral conditions, and the temperature change causes an error in the volume value V. .

Therefore, if the diagnosis of the flow sensor is performed based on the output correlation value expressed by the equation (4), there is a problem that the output correlation value is erroneous and cannot be accurately diagnosed.

Patent Document 1: Japanese Patent Publication No. 4881391

Therefore, the main technical problem to be solved by the present invention is that the function of the flow sensor can be more accurately diagnosed and the misdiagnosis can be reduced despite the measurement of the variation of the peripheral conditions.

That is, the diagnostic system of the present invention includes: a fluid sensor that measures a fluid; an output correlation value measuring unit that measures an output correlation value, the output correlation value being an output value of the fluid sensor or with the fluid a value related to an output value of the sensor; a reference value storage unit stores a reference value set in advance to determine whether the output correlation value is normal; and a correction unit that outputs the output based on a measurement surrounding condition of the output correlation value At least one of the correlation value and the reference value is corrected; and the diagnosis unit diagnoses the fluid sensor based on the output correlation value and the reference value based on the correction result of the correction unit.

According to this configuration, the output correlation value or the reference value is corrected based on the fluid pressure and the temperature, which are causes of the error in the output correlation value, and the correlation value or the reference value is corrected based on the correction result, and based on the output correlation value and the reference value. The function of the fluid sensor, thereby being able to more accurately diagnose the function of the fluid sensor, improve the diagnostic accuracy, and thereby reduce misdiagnosis. Additionally, the output correlation value includes an output value of the fluid sensor or a value associated with the output value of the fluid sensor. In the case where the fluid sensor is a flow sensor, the output correlation value is a flow value as an output value of the flow sensor, a volume value as a value related to the flow value, and the like. Further, specifically, the diagnosis unit performs a diagnosis of diagnosing the fluid feeling based on the corrected output-related value and the uncorrected reference value when the correction unit corrects only the output-related value. When the correction unit corrects only the reference value, the detector diagnoses the flow rate sensor based on the uncorrected output-related value and the corrected reference value, and the correction unit corrects the When the correlation value and the reference value are output, the fluid sensor is diagnosed based on the corrected output correlation value and the corrected reference value.

Further, in the above-described diagnostic system, it is preferable to further include a reference output-related value storage unit that uses a reference output-related value measured under measurement surrounding conditions as a reference in advance and the measurement peripheral condition Associatedly storing, the correction unit, based on a deviation between a measurement peripheral condition associated with the output correlation value and a measurement peripheral condition associated with the reference output correlation value, the output associated value and the At least one of the reference values is corrected.

According to this configuration, the reference output correlation value as the reference of the reference value can be measured in the same manner as the output correlation value, and it is not necessary to add a new sensor or the like when determining the reference value, and the system can be simplified and cost reduced.

Furthermore, in any of the above diagnostic systems, it is preferred that the measurement peripheral conditions comprise the pressure and/or temperature of the fluid. Further, the pressure of the fluid may be a primary pressure or a secondary pressure generated by the influence of a pipe or an external device connected to the fluid sensor. Further, the temperature of the fluid may be a temperature that affects the measurement of each sensor such as a pressure sensor.

Furthermore, it is preferred that the output correlation value is a value based on a time integral value of the pressure of the fluid as a function of time. Specifically, it is preferable that the output correlation value is a value based on a mass flow integral value, wherein a mass flow calculated based on a pressure difference generated between upstream and downstream of the fluid flow is integrated at a specified time The mass flow integral value is obtained. More specifically, it is preferable that the output correlation value is calculated based on a pressure change amount and a temperature change amount between the specified time in the upstream or downstream of the fluid flow, and the mass flow integral value The volumetric value of the fluid.

If such an output correlation value is used, when the pressure that changes with time is continuously measured, even if there is local peak-to-valley noise in a part of the pressure value, since the time integral value of the noise is small, it can be lowered. The influence of noise on the output correlation value can improve the diagnostic accuracy. In addition, since the differential pressure mass flow controller can measure the value for calculating the output-related value by using each sensor that is originally provided, it is not necessary to add a sensor or the like, and the flow can be diagnosed with high precision. Sensor.

Further, in any of the above diagnostic systems, it is preferable to further include a flow rate adjusting mechanism that cuts off the flow of the fluid, the flow rate adjusting mechanism causing fluid pressure on the upstream side or the downstream side by cutting off the flow of the fluid Change of time. It is further preferred that the fluid sensor comprises a resistance body that creates a pressure differential between upstream and downstream of the fluid.

Here, the "flow rate adjustment mechanism" includes not only a flow rate control mechanism that constitutes a flow rate control device such as a differential pressure type mass flow controller or a thermal mass flow controller, but also includes, for example, an opening and closing valve, and the like. The flow controller is independently disposed on a pipe extending from the inlet port or the outlet port of the mass flow controller. In other words, any member that can open and close the fluid flow path may be used.

According to this configuration, the function of the fluid sensor is diagnosed by the pressure change with respect to the very small flow path volume between the flow rate adjusting mechanism and the resistance body, so that the decompression time becomes shorter and the diagnosis can be shortened. time needed. In addition, if it is a differential pressure mass flow controller, it is possible to diagnose the flow sensor using the mechanism originally provided.

Further, in the diagnostic method of the fluid sensor of the present invention, an output correlation value is determined, the output correlation value being an output value of the fluid sensor or a value related to an output value of the fluid sensor; Correcting at least one of the output-related value and a reference value set in advance to determine whether the output-related value is normal or not based on the measurement surrounding condition of the output-related value; and based on the result of the correction The output correlation value and the reference value are used to diagnose the fluid sensor.

Further, the storage medium of the present invention stores a program used in a diagnostic system for diagnosing a function of a fluid sensor for measuring a fluid, wherein the program causes the computer to function to determine an output correlation value, the output associated value And a value associated with an output value of the fluid sensor or an output value of the fluid sensor; and the output correlation value and the value of the output correlation value according to the measured peripheral condition of the output correlation value Correction is performed by at least one of the normal and predetermined reference values; and the fluid sensor is diagnosed based on the output correlation value based on the result of the correction and the reference value.

In addition, the flow control device of the present invention includes: a flow sensor that measures a flow rate of the fluid; and a flow control mechanism that is disposed on an upstream side of the flow sensor, and controls the output according to an output value of the flow sensor a flow rate of the fluid; an output correlation value measuring unit that measures an output correlation value, the output correlation value being an output value of the flow sensor or a value related to an output value of the flow sensor; a reference value storage unit, a reference value that is set in advance to determine whether the output correlation value is normal or not; and a correction unit that corrects at least one of the output correlation value and the reference value based on a measurement surrounding condition of the output correlation value; The diagnosis unit diagnoses the flow rate sensor based on the output correlation value and the reference value based on the correction result of the correction unit.

According to the present invention thus constituted, since the output correlation value is diagnosed in consideration of the measurement peripheral condition which is the cause of the error in the output correlation value, the function of the fluid sensor can be more accurately diagnosed, and misdiagnosis can be reduced.

The diagnostic system of the present invention will now be described with reference to the accompanying drawings.

The diagnostic system of the present invention is used to diagnose the function of a fluid sensor, such as a flow measurement device or a flow control device (mass flow controller) having a flow sensor. Specific examples of the flow rate control device include a differential pressure mass flow controller, a thermal mass flow controller, and the like.

<First embodiment>

As shown in FIG. 1, the diagnostic system DS of the present embodiment includes a flow rate control device MF1 and on-off valves UV and DV provided on the upstream and downstream sides of the flow rate control device MF1, and the diagnostic system DS is applied, for example, to a gas control system, The gas control system is for supplying a material gas or a cooling gas to a film forming chamber (chamber) of the semiconductor film forming apparatus.

The flow control device MF1 is a differential pressure mass flow controller. Specifically, the flow control device MF1 includes a flow path 10 for fluid flow, a flow sensor 20 for measuring the flow rate of the fluid flowing in the flow path 10, and a flow control mechanism 30 disposed upstream of the flow sensor 20 The side sensor and the pressure sensor 40 are disposed on the upstream side of the flow rate control mechanism 30 for measuring the supply pressure.

Although not shown, the flow path 10 is provided with an introduction port at the upstream end and a delivery port at the downstream end. Further, for example, the introduction port is connected to the gas supply mechanism via a pipe, and the gas supply mechanism supplies a gas for introducing the flow rate control device MF1, and the outlet port is connected to the film forming chamber by a pipe, and the film forming chamber is controlled by the flow rate control device. The supply destination of the flow of gas.

The flow sensor 20 includes a resistance body 50 that causes a pressure difference to be generated in the flow path 10, an upstream side pressure sensor 60 that measures the upstream side pressure of the resistance body 50, and a downstream side pressure sensor 70 that faces the resistance body 50. The downstream side pressure is measured; and the temperature sensor 80 measures the temperature between the flow rate control mechanism 30 and the resistance body 50. In addition, the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) are absolute pressure type pressure sensors.

As shown in FIG. 3, the resistance body 50 is for generating a pressure difference between the inlet port 50a on the upstream side and the outlet port 50b on the downstream side. Further, as a specific structure, mainly composed of two kinds of rings (the first ring body 51 and the second ring body 52), the first ring body 51 has a smaller outer diameter and a larger inner diameter than the second ring body 52. The second ring body 52 has a larger outer diameter and a smaller inner diameter than the first ring body 51. Further, the two ring bodies (the first ring body 51 and the second ring body 52) are configured to be alternately laminated from the first ring body 51, and finally the disk body 53 is laminated, whereby each ring body (first ring) A space is formed in the center of the laminated body in which the body 51 and the second ring body 52 are laminated, and one end of the space is closed, thereby forming the introduction port 50a. Further, the second ring body 52 laminated between the first ring bodies 51 is provided with a flow path space 54 that penetrates partially leaving the inner wall and the outer wall. Thereby, the gap formed between the inner surface of the first ring body 51 and the inner wall of the second ring body 52 constitutes the introduction passage 54a leading to the flow path space 54, on the outer surface of the first ring body 51 and the second The gap formed between the outer walls of the ring body 52 constitutes an outlet passage 54b leading to the outside. Further, the outlet port 50b is formed by the outlet passage 54b. With such a configuration, by adjusting the number of laminated sheets of the ring body (the first ring body 51 and the second ring body 52) and the range of the flow path space 54, the inlet port 50a side and the outlet port 50b side can be freely set. The amount of differential pressure produced.

The flow rate control mechanism 30 is configured to be capable of adjusting the valve opening degree by an actuator such as a piezoelectric element.

Further, the flow rate control device MF1 includes a control unit 90 for exerting a flow rate control function, a flow rate sensor diagnosis function, a pressure sensor diagnosis function, a flow rate control mechanism diagnosis function, and the like. The control unit 90 has a so-called computer including a CPU, a memory, an A/D converter or a D/A converter, an input/output mechanism, and the like, and the control unit 90 executes a program stored in the memory so that the control unit 90 Each device works in concert to perform various functions. Further, the control unit 90 is connected to an input/output unit (not shown).

Specifically, as shown in FIG. 2, the control unit 90 includes a flow rate measuring unit 90a, a control value calculating unit 90b, a valve control unit 90c, an output-related value measuring unit 90d, a reference output-related value storage unit 90e, and a reference value storage unit. 90f, correction unit 90g, deviation calculation unit 90h, flow sensor diagnosis unit 90i, pressure sensor diagnosis unit 90j, pressure sensor correction unit 90k, flow rate control unit diagnosis unit 90l, initialization execution unit 90m, and diagnosis result output Department 90n.

The flow rate measuring unit 90a calculates the fluid value based on the detected value (pressure value) detected by the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) provided in the flow rate sensor 20. Flow value. Further, the flow rate measuring unit 90a is configured to receive the detected values detected by the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) at a predetermined timing.

The control value calculation unit 90b calculates a control value for performing feedback control on the flow rate control unit 30 based on the deviation between the flow rate value calculated by the flow rate measurement unit 90a and a preset reference flow rate value.

The valve control unit 90c is for controlling the opening of the valve of the flow rate control mechanism 30 and the opening and closing valves UV and DV. Specifically, during the normal operation, feedback control that changes the opening degree of the valve of the flow rate control unit 30 based on the control value calculated by the control value calculation unit 90b is performed. Further, the valve control unit 90c completely closes the valve of the flow rate control mechanism 30 based on the flow rate sensor diagnosis instruction input from the input/output mechanism, and opens the opening and closing valves UV and DV. Further, the valve control unit 90c completely closes the opening and closing valve UV based on the pressure sensor diagnosis instruction input from the input/output mechanism, and opens the valve of the flow rate control mechanism 30 and the opening and closing valve DV. Further, the valve control unit 90c completely closes the valve of the flow rate control mechanism 30 based on the flow rate control mechanism diagnosis instruction input from the input/output mechanism, and opens the opening and closing valves UV and DV.

The output correlation value measuring unit 90d detects the detected values based on the two pressure sensors (the upstream side pressure sensor 60, the downstream side pressure sensor 70) and the temperature sensor 80 provided in the flow rate sensor 20 ( Pressure value, temperature value), calculate the volume value of the fluid (output correlation value). Further, the output correlation value measuring unit 90d starts measurement of the output correlation value based on the case where the flow rate sensor diagnosis instruction is input from the input/output unit. Specifically, when the flow sensor diagnostic instruction is input from the input/output mechanism, the valve of the flow rate control mechanism 30 is completely closed by the valve control unit 90c, and the opening and closing valves UV and DV are opened. Then, the downstream side of the flow rate control mechanism 30 starts decompression by a discharge mechanism (not shown) provided on the downstream side, and the discharge mechanism is, for example, an exhaust pump connected to the film forming chamber. Further, the mass flow rate Q of the fluid calculated using the pressure values P1 and P2 measured by the respective pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) and using the above formula (1) is specified. The integration is performed in time to calculate the mass flow integral value n. Next, the pressure difference ΔP of the pressure measured by the upstream side pressure sensor 60 at the beginning and the end of the specified time and the temperature value T measured by the temperature sensor 80 are used, and the measured volume value is calculated using the equation (4). V. Further, the measured volume value V indicates the flow path volume from the flow rate control mechanism 30 to the introduction port 50a of the resistance body 50. Further, the output-related value measuring unit 90d is configured to receive the detected values detected by the two pressure sensors (the upstream side pressure sensor 60, the downstream side pressure sensor 70) and the temperature sensor 80 at the designated timing.

The reference output-related value storage unit 90e stores the reference volume value VS measured under the measurement peripheral condition specified in advance, for example, before the flow control device MF1 is shipped from the manufacturing plant or the flow control device MF1 is actually connected to the semiconductor manufacturing device or the like. This benchmark data is used to determine the surrounding conditions.

The reference value storage unit 90f stores a reference value for determining whether or not the measured volume value V is normal. In addition, the reference value is determined based on the reference volume value VS. In the present embodiment, the threshold value is set for the ratio of the measured volume value V to the reference volume value VS deviation, and it is determined whether or not the measured volume value V is normal by determining whether or not the deviation ratio exceeds the threshold value. Therefore, the threshold of the deviation ratio becomes the reference value.

The correction unit 90g associates the measurement volume value V with the measurement peripheral condition when the measurement volume value V is measured, and generates measurement data based on the deviation between the measurement surrounding conditions included in the measurement data and the measurement peripheral conditions included in the reference data. Correct the measured volume value V or the reference value. In the present embodiment, the threshold value is corrected, and the threshold value is an upper limit value of the deviation ratio of the measured volume value V to the reference volume value VS.

The deviation calculating unit 90h calculates the deviation ratio of the measured volume value V to the reference volume value VS.

The flow rate sensor diagnosis unit 90i determines whether or not the measurement volume value V is normal based on the measured volume value V and the reference value based on the correction result of the correction unit 90g, and diagnoses the function of the flow rate sensor 20.

The pressure sensor diagnosing unit 90j detects whether the pressure values of the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) provided in the flow sensor 20 are preset. Diagnose within the specified pressure range. Specifically, when the pressure sensor diagnosis instruction is input from the input/output mechanism, the valve control unit 90c completely closes the opening and closing valve UV, and opens the valve of the flow rate control mechanism 30 and the opening and closing valve DV. Then, the downstream side of the flow rate control mechanism 30 starts the pressure reduction by the discharge mechanism provided on the downstream side. In the pressure sensor diagnostic state, it is diagnosed whether the two pressure sensors (the upstream side pressure sensor 60, the downstream side pressure sensor 70) are within a prescribed pressure range.

The pressure sensor correction unit 90k performs zero point correction on the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) provided to the flow rate sensor 20. Specifically, in the above-described pressure sensor diagnosis state, when the pressure sensor correction indication is input from the input/output mechanism, the two pressure sensors (the upstream side pressure sensor 60, the downstream side pressure sensor) 70) The zero point is corrected.

The flow rate control unit diagnosing unit 90l diagnoses the flow rate control unit 30. Specifically, when the flow rate control mechanism diagnosis instruction is input from the input/output mechanism, the valve of the flow rate control unit 30 is completely closed by the valve control unit 90c, and the opening and closing valves UV and DV are opened. Then, the upstream side of the flow rate control mechanism 30 starts the pressure increase by the supply mechanism provided on the upstream side, and the downstream side of the flow rate control mechanism 30 starts the pressure reduction by the discharge mechanism provided on the downstream side. Then, whether or not the rate of increase of the flow rate value measured by the flow rate measuring unit 90a is within the range of the predetermined increase rate is diagnosed.

The initialization execution unit 90m resets the reference data stored in the reference output related value storage unit 90e. Specifically, when an initialization instruction is input from the input/output means, the initialization execution unit 90m covers the reference by using the reference volume value VS ́ that is newly measured again under another measurement peripheral condition and the new reference material associated with the measurement peripheral condition. The reference data stored in the correlation value storage unit 90e is output, and the reference value stored in the reference value storage unit 90f is reset based on the new reference data.

The diagnosis result output unit 90n outputs the diagnosis result of each diagnosis unit from the input/output unit by image, sound, or the like.

Next, a diagnosis process of the flow rate sensor 20 in the flow rate control device of the present embodiment will be described with reference to Fig. 6 .

First, when the flow sensor diagnostic indication is input from the input/output mechanism, before the diagnosis is started, when the pressure measured by the upstream side pressure sensor 60 is lower than the starting pressure (P1 _START ), the pressure is raised to make it high. At the beginning of the pressure.

Next, the valve control unit 90c completely closes the valve of the flow rate control mechanism 30 that functions as the flow rate control function based on the flow rate sensor diagnosis instruction, and opens the opening and closing valves UV and DV (step S101).

Further, when the valve of the flow rate control mechanism 30 is completely closed, the downstream side of the flow rate control device MF1 is sucked and decompressed by the exhaust pump, and the pressure in the flow path changes with time.

Next, the output correlation value measuring unit 90d uses the pressure values detected by the pressure sensor upstream side pressure sensor 60 and the downstream side pressure sensor 70) and calculates the mass flow rate Q using the above formula (1) (step S102) Next, the mass flow rate Q is time-integrated within a predetermined time, thereby calculating the mass flow integral value n (step S103). Further, the pressure change amount ΔP1 is calculated based on the pressure value detected by the upstream side pressure sensor 60 at the start and end of the designated time, and the temperature value T detected by the temperature sensor 80 is obtained (step S104). . Then, the mass flow rate integral value n, the pressure change amount ΔP1, and the temperature value T are used, and the measured volume value V is calculated using the equation (4) (step S105). Further, based on the series of calculations, it can be said that the mass flow integral value n is a value based on the pressure integral value.

Next, the correction unit 90g generates measurement data relating the measurement volume value V to the measurement peripheral condition when the measurement volume value V is measured (step S106). Further, by referring to the reference data and the measurement data, the deviation between the measurement surrounding conditions of the reference data and the measurement surrounding conditions of the measurement data is calculated, and the threshold value is corrected in consideration of the deviation of the measurement surrounding conditions, and the threshold value is used for determining the measurement. The upper limit of the deviation ratio of the volume value V to the reference volume value VS (step S107). This corrects the reference value.

Finally, the deviation calculating unit 90h calculates the deviation ratio of the measured volume value V to the reference volume value VS (step S108), and the flow rate sensor diagnostic unit 90i determines whether or not the deviation ratio exceeds the corrected threshold (step S109). When the deviation ratio does not exceed the threshold value, the diagnosis result output unit 90n notifies that the function of the flow rate sensor 20 is normal, and can continue to be used (step S110). If the deviation ratio exceeds the threshold value, the diagnosis result output unit The function of 90n notifies the flow sensor 20 that there is an abnormality (step S111).

Further, as a result of the diagnosis of the flow rate sensor 20, when it is determined that the flow rate sensor 20 is normal, the flow rate sensor 20 is returned to the flow rate control function, and on the other hand, it is determined that the flow rate sensor 20 is abnormal. Next, the diagnostic process of the pressure sensors 60, 70 is performed.

Here, in the diagnosis process of the flow rate sensor, each parameter (specifically, the pressure change amount ΔP1, the temperature value T, the mass flow integral value n, etc.) is substituted into the equation (4) that is derived using the state equation. This calculates the volume value V (internal volume) and uses the volume value V to determine whether the function of the flow sensor is abnormal, but the inventors have continuously studied and found that the parameters not reflected in the above equation of state are also It affects the calculation of the volume value V.

Specifically, when the above-described step S101 is performed, if the pressure on the downstream side of the resistance body 50 becomes high, in other words, if the secondary pressure of the flow rate control device MF becomes high, the upstream side and the downstream side of the resistance body 50 are thereby caused. The pressure difference between them becomes smaller. Along with this, the pressure drop time is shortened, and as a result, the cumulative time (designated time) of the mass flow integral value n is shortened, and the number of samples of the mass flow rate Q for calculating the mass flow integral value n is decreased, thereby the volume value. V is prone to errors. Moreover, it can be seen that the error of the volume value V affects the diagnostic accuracy of the flow sensor.

Therefore, by providing the correction unit (diagnosis standard correction unit) and strictly controlling the diagnosis criterion of the flow sensor 20, it is possible to prevent the entire system in which the flow rate control device MF is assembled from being damaged due to misdiagnosis of the flow rate control device MF. When the pressure difference generated between the upstream and downstream of the fluid is equal to or less than a predetermined value, the correction unit performs correction for increasing or increasing the output correlation value of the measurement, or makes the reference value smaller (decreased). ) correction. Further, the correction may be performed by the correction unit 90g, and another correction unit (diagnostic criterion correction unit) independent of the correction unit 90g may be provided, and the correction may be performed by the other correction unit.

Next, a diagnosis process of the pressure sensor in the flow rate control device of the present embodiment will be described with reference to Fig. 7 .

In the case where the diagnosis of the flow sensor 20 is diagnosed as having an abnormality, when the pressure sensor diagnosis instruction is input from the input/output mechanism, the valve control portion 90c completely closes the opening and closing valve UV according to the instruction, and controls the flow rate. The valve of the mechanism 30 and the opening and closing valve DV are opened (step S201). Next, the pressure sensor diagnosing unit 90j diagnoses whether or not the pressure value measured by the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) is within a predetermined pressure range (step S202). ). Further, when the pressure value is within the predetermined pressure range, the diagnosis result output unit 90n notifies the upstream side pressure sensor 60 and the downstream side pressure sensor 70 that it is normal (step S203), and the pressure value is not at When the predetermined pressure range is within the predetermined pressure range, the diagnosis result output unit 90n notifies the upstream side pressure sensor 60 and the downstream side pressure sensor 70 that the abnormality is abnormal (step S204).

In the case where the diagnosis of the upstream side pressure sensor 60 and the downstream side pressure sensor 70 is normal, the diagnosis process of the flow rate control unit 30 to be described later is performed. On the other hand, in the case where the diagnosis of the upstream side pressure sensor 60 and the downstream side pressure sensor 70 is diagnosed as having an abnormality, when the pressure sensor correction instruction is input from the input/output mechanism, the two pressure senses In a state where the pressure value measured by the detector (the upstream side pressure sensor 60 and the downstream side pressure sensor 70) becomes equal to or lower than the specified pressure value, the pressure sensor correcting portion 90k faces the two pressure sensors (upstream side) The pressure sensor 60 and the downstream side pressure sensor 70) perform zero point correction (step S205). Next, the diagnosis of the flow sensor 20 is performed again (step S206). Further, when it is diagnosed that the flow rate sensor 20 is normal, the diagnosis result output unit 90n notifies the situation, and thereafter returns to the flow rate control function (step S207). On the other hand, when it is diagnosed that there is an abnormality in the flow sensor 20, the diagnosis result output unit 90n notifies the upstream side pressure sensor 60 and the downstream side pressure sensor 70 that there is an abnormality requiring repair (step S208).

Next, a diagnosis process of the flow rate control mechanism 30 in the flow rate control device MF1 of the present embodiment will be described with reference to Fig. 8 .

First, in the case where the diagnosis of the flow sensor 20 is diagnosed as having an abnormality, in the case where the diagnosis is normal in the diagnosis of the upstream side pressure sensor 60 and the downstream side pressure sensor 70, when the flow is input from the input/output mechanism When the control unit diagnoses the instruction, the valve control unit 90c completely closes the valve of the flow rate control unit 30 based on the instruction, and opens the opening and closing valves UV and DV (step S301). Next, the flow rate control unit diagnosing unit 901 diagnoses whether or not the rate of increase of the flow rate value measured by the flow rate measuring unit 90a is within the predetermined increase rate range (step S302). Further, when the increase rate is within the predetermined increase rate range, the diagnosis result output unit 90n notifies the flow rate control mechanism 30 that it is normal (step S303), and on the other hand, that the increase rate is not within the prescribed increase rate range. In this case, the diagnosis result output unit 90n notifies the flow rate control unit 30 that there is an abnormality requiring repair (step S304). The abnormality of the flow control mechanism 30 is likely to be a valve seat leak.

Further, when the diagnosis is normal in the diagnosis of the flow rate control unit 30, the initialization is next performed (step S305). In the initialization, when the initialization instruction is input from the input/output means, the initialization execution unit 90m covers the reference output with the reference data value VS ́ re-measured again under another measurement peripheral condition and the new reference data associated with the measurement peripheral condition. The reference data stored in the correlation value storage unit 90e further resets the threshold value stored in the reference value storage unit 90f based on the new reference data. Therefore, when the amount of leakage of the valve of the flow rate control mechanism 30 is a leakage amount that does not affect the function of the flow rate control device MF, the flow rate control device MF can be replaced without being replaced. And then return to the flow control function.

Further, after the initialization of the flow rate control device MF1 is performed, the diagnosis of the flow sensor 20 is performed again, and in the case where it is diagnosed that there is an abnormality in the flow sensor 20, it can be judged that the upstream side pressure sensor 60 and the downstream side are under pressure. The reason other than the sensor 70 and the flow control mechanism 30 causes the function of the flow sensor 20 to be abnormal. Further, for this reason, the clogging of the resistance body 50, the leakage of the flow path 10, the gas specification of the flow rate control device MF1, and the actual gas can be considered.

In addition, when the initialization is performed, the reference value is sequentially replaced with the reference value after the initialization. Therefore, it is preferable to include the reference value change amount calculation unit that calculates the initial reference value stored in the reference value storage unit 90f (setup) The reference value change amount determining unit determines whether the change amount exceeds a predetermined change amount set in advance, and the warning unit notifies that the change amount exceeds a predetermined change amount set in advance. Further, the specified change amount is an upper limit value of the change amount of the reference value after initialization with respect to the initially set reference value, and the output correlation value is calculated by using the maximum value of the valve seat leakage amount which is secured in advance by the flow rate control mechanism 30. The upper limit value can be remitted based on the deviation ratio with respect to the reference output. Further, when a plurality of initializations are performed, the total amount of change with respect to the initially stored reference value is the amount of change after initialization.

According to this configuration, the diagnosis of each element of the flow rate control device MF1 that cannot be determined by the diagnosis of the flow rate sensor 20 can be sequentially performed, and the element that causes the abnormality of the flow rate sensor 20 can be locked. As a result, the possibility of abnormality that can be dealt with by correction, repair, replacement, and the like is reduced, and misdiagnosis can be reduced.

Further, in the present embodiment, the user manually inputs each instruction from the input/output unit, and the instructions for storing the respective instruction timings may be stored in advance in the memory, and each of the programs may be automatically executed by the program. Instructions.

Further, in the present embodiment, after the upstream side pressure sensor 60 and the downstream side pressure sensor 70 are corrected, the flow rate sensor 20 is diagnosed to diagnose the function of the flow rate sensor 20, but is not limited to the upstream side. The pressure sensor 60 and the downstream side pressure sensor 70 may similarly perform diagnostic correction on the temperature sensor 80, other sensors, and the like. That is, it is preferable that the configuration includes: a fluid sensor for measuring a fluid; and a diagnosis unit that measures an output correlation value and compares the measured output correlation value with a preset reference value to diagnose the function of the fluid sensor. The output correlation value is an output value of the fluid sensor or a value related to an output value of the fluid sensor, wherein the diagnostic portion will be part or all of the fluid sensor The output correlation value measured after the factor is corrected is compared with the reference value. Additionally, the fluid sensor is a flow sensor, the elements of the flow sensor comprising a pressure sensor and/or a temperature sensor. In addition, in this case, the fluid sensor may be a flow sensor, and further includes a flow control mechanism for controlling a flow rate of the fluid by the valve according to the flow rate value measured by the flow sensor. When the valve of the flow control mechanism is closed, the pressure is reduced, and the state of the valve of the flow control mechanism is diagnosed based on whether or not the increase rate of the flow rate measured by the flow sensor is within the predetermined increase rate.

In the present embodiment, the valve control unit 90c included in the flow rate control device MF controls each valve based on each instruction input from the input/output unit. However, the present invention is not limited thereto, and may be provided in the flow rate control device. A valve control unit provided by a control device external to the MF controls each valve.

<Other Embodiments>

As another embodiment, the flow rate control device MF2 shown in FIG. 9 is a modification of the flow rate control device MF1 of the first embodiment, and an opening and closing valve 31 is provided on the downstream side of the flow rate sensor 20, and the temperature sensor 80 is provided. Between the resistance body 50 and the opening and closing valve 31. In such a flow control device MF2, ROR type diagnosis can be performed. Specifically, when the function of the flow rate sensor 20 is diagnosed, when the gas is continuously supplied in a state where the on-off valve 31 is closed, the upstream side of the opening and closing valve 31 is boosted. Further, in this case, since the pressure difference is also generated on the upstream side and the downstream side of the resistance body 50, it is possible to perform the respective sensors (the upstream side pressure sensor 60, the downstream side pressure sensor 70, and the temperature sensor 80). The measured value of the volume 50 is calculated between the resistance body 50 and the opening and closing valve 31, and the volume value V can be used to diagnose the function of the flow sensor 20. Further, in the present embodiment, it is necessary to change the reference value by referring to the primary pressure change or the temperature change generated by the piping connected to the upstream side of the flow rate sensor 20 or the external device as the measurement peripheral condition.

Further, as another embodiment, it is particularly possible to consider setting in the flow rate control device MF1 of the first embodiment instead of the two pressure sensors (the upstream side pressure sensor 60 and the downstream side pressure sensor 70). A mode of a differential pressure sensor that measures a pressure difference between the upstream side and the downstream side of the resistance body 50. If this is the case, the influence of the nozzle of the pressure sensor can be reduced and the cost can be reduced, even if the fluid with variable pressure can be used better. Further, since the flow rate control device MF1 of the first embodiment has a chamber (vacuum) such as a film forming chamber connected to the secondary side, the measured value of the differential pressure sensor can be measured based on the secondary side (zero). Find the flow rate on the primary side.

Further, in the above-described embodiment, the diagnosis is performed based on whether or not the deviation ratio of the calculated volume value V to the reference volume value VS exceeds the threshold value. However, the present invention is not limited thereto, and may be based on the volume value V with respect to the reference volume value VS. Deviation to diagnose. In this case, the upper limit value and/or the lower limit value may be set based on the reference output correlation value, and the upper limit value and/or the lower limit value may be used as the reference value. Further, in the above-described embodiment, the reference value is corrected based on the deviation between the measurement surrounding conditions of the measurement data and the measurement surrounding conditions of the reference data, but the output correlation value of the measurement data may be corrected. Further, in the above-described embodiment, when the volume value V is calculated, the pressure change amount and the temperature value at the start and end of the specified time are used, but the flow rate change amount may be used.

Further, in the above-described embodiment, the pressure and the temperature of the fluid are exemplified as the measurement of the peripheral conditions. However, the condition is not limited thereto. For example, in the diagnosis as in the above-described embodiment, the measurement is performed as a cause of the error of the volume value V. Conditions, in addition to the above-described secondary pressure and temperature, it is also possible to consider the offset of the reference point of each pressure sensor, the clogging of the resistance body, the valve seat leakage of the flow control mechanism, and the like. Therefore, the reference value can also be corrected based on these measurement peripheral conditions.

Further, in the above embodiment, the flow sensor includes a temperature sensor, but the flow sensor may be provided with a structure required for measuring the flow rate, such as a temperature sensor, which is not directly related to the measurement of the flow rate. The sensor is not necessarily included in the flow sensor. Further, the temperature sensor may be provided as a sensor for measuring the peripheral conditions of the measurement, or may be provided independently of the flow sensor.

Further, the diagnostic system of the present invention can be applied to a flow rate control device and a pressure control device as in the above-described embodiment, and can also be applied to a flow rate measuring device. Further, the fluid sensor of the present invention is not limited to the flow rate sensor used in the above embodiment, and a pressure sensor, a temperature sensor, or the like can be used.

10‧‧‧Flow

20‧‧‧Flow sensor

30‧‧‧Flow Control Agency

31‧‧‧Opening and closing valve

40‧‧‧pressure sensor

50‧‧‧ resistance body

50a‧‧‧Import

50b‧‧‧Export

51‧‧‧First ring

52‧‧‧Second ring

53‧‧‧ disc body

54‧‧‧Flow space

54a‧‧‧Importing channel

54b‧‧‧ Export Channel

60‧‧‧Upstream side pressure sensor

70‧‧‧ downstream pressure sensor

80‧‧‧temperature sensor

90‧‧‧Control Department

90a‧‧‧Flow Measurement Department

90b‧‧‧Control value calculation unit

90c‧‧‧Valve Control Department

90d‧‧‧Output correlation value measurement department

90e‧‧‧Reference output correlation value storage unit

90f‧‧‧ reference value storage

90g‧‧‧Amendment

90h‧‧‧Deviation calculation department

90i‧‧‧Flow Sensor Diagnostics Department

90j‧‧‧ Pressure Sensor Diagnostics Department

90k‧‧‧ Pressure Sensor Correction Department

90l‧‧‧Flow Control Department Diagnostics Department

90m‧‧‧Initial Implementation Department

90n‧‧‧Diagnostic Results Output Department

Fig. 1 is a schematic view showing a flow rate control device according to a first embodiment. FIG. 2 is a functional configuration diagram showing a control unit of the flow rate control device according to the first embodiment. 3 is a cross-sectional view showing a resistance body of the flow rate control device according to the first embodiment. 4 is a graph showing changes in pressure measured with time by the upstream side pressure sensor of the flow rate control device of the first embodiment. Fig. 5 is a graph for explaining a mass flow integral value of the flow rate control device of the first embodiment. Fig. 6 is a flowchart showing a flow rate sensor diagnosis process of the flow rate control device according to the first embodiment. FIG. 7 is a flowchart showing a pressure sensor diagnosis process of the flow rate control device according to the first embodiment. 8 is a flowchart showing a flow rate control mechanism diagnosis process of the flow rate control device according to the first embodiment. Fig. 9 is a schematic view showing a flow rate control device according to a second embodiment.

Claims (11)

A diagnostic system, comprising: a fluid sensor for measuring a fluid; an output correlation value measuring unit that determines an output correlation value, the output correlation value being an output value of the fluid sensor or a value related to the output value of the fluid sensor; a reference value storage unit storing a reference value set in advance to determine whether the output correlation value is normal; a correction unit according to the output correlation value Correcting at least one of the output correlation value and the reference value, and a diagnosis unit that outputs the correlation value and the reference value based on a correction result of the correction unit To diagnose the fluid sensor. The diagnostic system according to claim 1, further comprising: a reference output correlation value storage unit, wherein the reference output correlation value storage unit uses a reference output correlation value measured under a measurement peripheral condition as a reference in advance The measurement peripheral condition is stored in association; the correction unit is based on a deviation between the measurement peripheral condition associated with the output correlation value and the measurement peripheral condition associated with the reference output correlation value, Correcting at least one of the output correlation value and the reference value. The diagnostic system of claim 1 or 2, wherein the assay peripheral condition comprises a pressure and/or a temperature of the fluid. The diagnostic system of claim 1 or 2, wherein the output correlation value is a value based on a time integral value of the pressure of the fluid as a function of time. The diagnostic system of claim 1 or 2, wherein the output correlation value is based on a value of a mass flow integral value, wherein a pressure difference generated between upstream and downstream based on the fluid flow is calculated The mass flow rate is integrated over a specified time to obtain the mass flow integral value. The diagnostic system according to claim 5, wherein the output correlation value is a pressure change amount and a temperature change amount between the specified time in the upstream or downstream, and the mass flow rate A volume value of the fluid calculated from the integral value. The diagnostic system according to claim 6, further comprising: a flow rate adjusting mechanism that cuts off the flow of the fluid; the flow rate adjusting mechanism causes a fluid on the upstream side or the downstream side by cutting off the flow of the fluid The pressure changes over time. A diagnostic system according to claim 7 wherein said fluid sensor comprises a resistance body that creates a pressure differential between upstream and downstream of said fluid. A method for diagnosing a fluid sensor for diagnosing a function of a fluid sensor for measuring a fluid, wherein: determining an output correlation value, the output correlation value being an output value of the fluid sensor or a value related to the output value of the fluid sensor; a predetermined reference to the output correlation value and a predetermined value for determining whether the output correlation value is normal or not according to a measured peripheral condition of the output correlation value At least one of the values performs a correction; and the fluid sensor is diagnosed based on the output correlation value and the reference value based on the result of the correction. A storage medium storing a program for use in a diagnostic system for diagnosing the function of a fluid sensor for measuring fluid, wherein the program causes the computer to perform the following functions: The output correlation value is an output value of the fluid sensor or a value related to the output value of the fluid sensor; and the output correlation value is compared according to a measured peripheral condition of the output correlation value At least one of a preset reference value is subjected to a correction in order to determine whether the output associated value is normal; and the fluid sensing is diagnosed based on the output associated value and the reference value based on a result of the correction Device. A flow control device, comprising: a flow sensor for measuring a flow rate of a fluid; a flow control mechanism disposed on an upstream side of the flow sensor, according to one of the flow sensors Outputting a value to control the flow rate of the fluid; an output correlation value measuring unit that determines an output correlation value, the output correlation value being the output value of the flow sensor or with the flow sensor a value related to the output value; a reference value storage unit that stores a reference value that is set in advance to determine whether the output correlation value is normal; and a correction unit that determines the peripheral condition according to the output correlation value And correcting at least one of the output correlation value and the reference value; and a diagnosis unit that diagnoses the flow sensing based on the output correlation value and the reference value based on the correction result of the correction unit Device.