Piezoelectric element diagnostic device, piezoelectric element diagnostic method, piezoelectric element diagnostic program, fluid control device, and vaporization system

Abstract

To make it possible to replace or maintain a piezoelectric element at an appropriate time.SOLUTION: A piezoelectric element diagnostic device 10 for diagnosing a piezoelectric element 321 built into a device includes a drive information acquisition unit 4d for acquiring drive information of the piezoelectric element 321 and a life calculation unit 4e for calculating a consumption life or remaining life of the piezoelectric element on the basis of the drive information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a piezoelectric element diagnostic device, a piezoelectric element diagnostic method, and a piezoelectric element diagnostic program. The present invention also relates to a fluid control device using the piezoelectric element diagnostic device, and a vaporization system using the piezoelectric element diagnostic device. [Background technology]

[0002] Piezo valves using a piezoelectric element are used as fluid control valves for mass flow controllers (MFCs) etc. In this type of piezo valve, the valve body is driven relative to the valve seat by applying a voltage to the piezoelectric element to expand and contract the element.

[0003] It is known that the degree of deterioration of this piezoelectric element varies depending on the magnitude of the applied voltage, the environmental temperature in which it is used, etc. In fact, in vaporization systems using a piezoelectric valve, the piezoelectric element is used in a high-temperature environment because the vaporized gas is controlled by the piezoelectric valve. Therefore, the piezoelectric element deteriorates (breaks down) more quickly than when used in a normal temperature environment.

[0004] Conventionally, as shown in Patent Document 1, the replacement timing of a piezoelectric element is determined by calculating in advance the mean time to failure (MTTF) until the piezoelectric element breaks down, and replacing the element based on this time. MTTF = MTTF0 x Kt x Kv MTTF0 is a standard MTTF, and is a value determined in advance through a reliability test. Kt is the acceleration factor (=1.4) determined by a specific operating temperature T. (T0-T) / 10 ) Kv is the acceleration coefficient determined by a specific operating voltage V (=(V0 / V) 2.5 ) T0 is the standard temperature when determining MTTF0. V0 is the standard voltage when determining MTTF0.

[0005] However, the above-mentioned mean time to failure (MTTF) can only calculate the life span when used at a certain temperature (T) and voltage (V). Therefore, when the usage conditions of the piezo valve change (for example, when the applied voltage or the usage temperature changes), it is difficult to accurately determine the replacement time. As a result, the piezo element may fail before the calculated mean time to failure. In addition, the piezo element may be replaced unnecessarily early compared to the mean time to failure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-8092 A Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to enable replacement or maintenance of a piezoelectric element at an appropriate time. [Means for solving the problem]

[0008] In other words, the piezoelectric element diagnostic device of the present invention is a piezoelectric element diagnostic device that diagnoses a piezoelectric element incorporated in an apparatus, and is characterized in that it includes a drive information acquisition unit that acquires drive information of the piezoelectric element, and a life calculation unit that calculates the consumed life or remaining life of the piezoelectric element based on the drive information.

[0009] Such a piezoelectric element diagnostic device calculates the consumed life or remaining life of the piezoelectric element based on the drive information, making it possible to replace or maintain the piezoelectric element at the appropriate time even if the usage conditions of the piezoelectric element change.

[0010] It is preferable that the life calculation unit calculates the consumed life or the remaining life based on an expected life of the piezoelectric element and the drive information acquired in advance. Here, the expected life of the piezoelectric element obtained in advance can be a standard life obtained in advance by a reliability test. This standard life is the standard mean time to failure (hereinafter, MTTFs) obtained in advance by a reliability test, and indicates the average time from when the piezoelectric element is put into operation until it breaks down. With this configuration, the standard life span (MTTFs) of the piezoelectric element is used, so that the consumed life span or remaining life span can be calculated more accurately.

[0011] As a specific embodiment of the drive information, it is desirable that the drive information includes at least one of the drive voltage of the piezoelectric element or the temperature of the piezoelectric element, and that the life calculation unit calculates the consumed life or the remaining life based on the expected life and at least one of the drive voltage of the piezoelectric element or the temperature of the piezoelectric element. According to this configuration, the consumed life or remaining life is calculated based on the drive voltage or temperature, which are likely to affect the life of the piezoelectric element, so that the consumed life or remaining life can be determined more accurately.

[0012] As a specific embodiment of the life calculation unit, it is considered that the life calculation unit calculates the total consumed life or the remaining life from the start of use of the piezoelectric element for each interval period.

[0013] Conventionally, the mean time to failure (MTTFr) taking into account usage conditions could only be calculated for a specific operating temperature (T) and voltage (V). On the other hand, in the present invention, the life calculation section is configured to calculate a unit consumed life, which is a consumed life per unit time in each interval period. For example, the MTTFr calculated from the representative values ​​of the driving voltage and temperature for each interval is used as the denominator, and the time of the interval is used as the numerator. This makes it possible to calculate the unit consumption life (hereinafter referred to as MTTFm), which is the consumption life per unit time. If the MTTFm calculated for each interval is added up, this total value (hereafter referred to as MTTFc) will be the total consumed lifespan of the piezoelectric element from the start of its use. When MTTFc reaches 1, it means that the expected lifespan (mean time to failure) taking into account the usage conditions has been reached.

[0014] A specific method of calculating the consumed life or remaining life is such that the drive information acquisition unit acquires the drive information at each sampling time, and the life calculation unit calculates the consumed life or remaining life using a representative value of multiple pieces of the drive information.

[0015] It is desirable that the piezoelectric element diagnostic device of the present invention further includes a comparison unit that compares the consumed lifespan or the remaining lifespan calculated by the lifespan calculation unit with a predetermined threshold value, and an alarm output unit that outputs an alarm based on the comparison result of the comparison unit. With this configuration, the user can be notified when it is time to replace or maintain the piezoelectric element, and can be prompted to replace or maintain the piezoelectric element.

[0016] As a specific embodiment of management associated with the replacement of a piezoelectric element, it is desirable that the piezoelectric element diagnostic device of the present invention further includes a replacement signal receiving unit that receives a replacement signal indicating that the piezoelectric element to be diagnosed has been replaced, and a reset unit that, upon receiving the replacement signal, resets the consumed lifespan or the remaining lifespan calculated by the lifespan calculation unit.

[0017] The piezoelectric element diagnosis device of the present invention further includes an automatic recognition unit that automatically recognizes the replaced piezoelectric element when the piezoelectric element to be diagnosed is replaced, and it is desirable that the life calculation unit calculates the consumed life or remaining life of the replaced piezoelectric element. With this configuration, the replaced piezoelectric element is automatically recognized, so that the management required for replacing the piezoelectric element with a new one can be reduced.

[0018] It is preferable that the device further comprises a life expectancy prediction unit that calculates a future consumed life expectancy or a remaining life expectancy based on the change in the consumed life expectancy or the remaining life expectancy obtained by the life expectancy calculation unit. With this configuration, it is possible to prepare new piezoelectric elements in advance, and to create plans in advance for replacing or maintaining piezoelectric elements.

[0019] In addition, the piezoelectric element diagnosis method of the present invention is a piezoelectric element diagnosis method for diagnosing a piezoelectric element incorporated in an apparatus, characterized in that it acquires driving information of the piezoelectric element and calculates a consumed life or remaining life of the piezoelectric element based on the driving information.

[0020] Furthermore, the piezoelectric element diagnosis program of the present invention is a piezoelectric element diagnosis program for diagnosing a piezoelectric element incorporated in an apparatus, and is characterized in that it has a function as a drive information acquisition unit that acquires drive information of the piezoelectric element, and a function as a life calculation unit that calculates the consumed life or remaining life of the piezoelectric element based on the drive information.

[0021] The piezoelectric element diagnostic program may be distributed electronically or may be recorded on a program recording medium such as a CD, DVD, or flash memory. Alternatively, edge processing (raw data is uploaded to the cloud and calculations are performed on the server) may be performed. The edge processing configuration allows data to be accumulated, which has the advantage of allowing all data to be referenced even when calculating the remaining life.

[0022] Furthermore, a fluid control device according to the present invention is characterized in that it comprises a piezoelectric valve in which a valve body is driven relative to a valve seat by a piezoelectric element, a valve control unit that controls the opening degree of the piezoelectric valve, and the above-mentioned piezoelectric element diagnosis device.

[0023] Furthermore, a vaporization system according to the present invention is characterized in that it comprises a vaporization unit that vaporizes a liquid raw material, a fluid control device that controls a flow rate of the gas vaporized by the vaporization unit, and the above-mentioned piezoelectric element diagnostic device. Effect of the Invention

[0024] Thus, according to the present invention, the consumed life or remaining life of the piezoelectric element is calculated based on the drive information, so that even if the usage condition of the piezoelectric element changes, the piezoelectric element can be replaced or maintained at the appropriate time. [Brief description of the drawings]

[0025] [Figure 1] 1 is a diagram illustrating a schematic configuration of an evaporation system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a functional block diagram of a control device and a piezoelectric element diagnosis device according to the embodiment. [Diagram 3] FIG. 11 is a functional block diagram of a control device and a piezoelectric element diagnosis device according to a modified embodiment. [Figure 4] FIG. 11 is a functional block diagram of a control device and a piezoelectric element diagnosis device according to a modified embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] An embodiment of a vaporization system incorporating a piezoelectric element diagnostic device according to the present invention will be described below with reference to the drawings. Note that in all of the drawings shown below, for ease of understanding, some parts are omitted or exaggerated as appropriate. The same components are given the same reference numerals and their explanations are omitted as appropriate.

[0027] <1. Basic configuration of vaporization system 100> The vaporization system 100 of this embodiment is incorporated in, for example, a semiconductor manufacturing line, and is intended to supply a predetermined flow rate of gas to a chamber in which a semiconductor manufacturing process is carried out.

[0028] Specifically, as shown in FIG. 1, the vaporization system 100 includes a vaporization unit 2 that vaporizes a liquid material, a mass flow controller 3 that controls the flow rate of the gas (hereinafter, material gas) vaporized by the vaporization unit 2, and a control device 4 that controls the operation of the vaporization unit 2, the mass flow controller 3, etc.

[0029] The vaporization section 2 includes a vaporizer 21 that vaporizes the liquid material by, for example, a baking method, a supply amount control device 22 that controls the amount of liquid material supplied to the vaporizer 21, and a preheater 23 that preheats the liquid material supplied to the vaporizer 21 to a predetermined temperature. The vaporizer 21, the supply amount control device 22, and the preheater 23 are attached to a main body block 5 having a flow path formed therein. The vaporization section 2 may be configured without the preheater 23.

[0030] Vaporizer 21 has storage container 211 for storing liquid material therein, and vaporization heater 212 provided in storage container 211 for vaporizing the liquid material. Storage container 211 is provided with liquid level sensor 213 for detecting the amount of stored liquid material. Note that various types of liquid level sensor 213 can be used, such as a self-heating type, a liquid temperature measurement type, a magnetic type, a capacitance type, and an ultrasonic type.

[0031] The supply amount control device 22 is an electromagnetic on-off valve. This electromagnetic on-off valve 22 is configured to open or close a flow path formed in the main body block 5 to supply or stop the supply of the liquid material to the vaporizer 21. Note that the supply amount control device 22 may be, for example, a control valve such as a piezo valve, a mass flow controller, or the like.

[0032] The preheater 23 has a preheating block 231 in which a flow path through which the liquid material flows is formed, and a preheater 232 provided in the preheating block 231 for preheating the liquid material. The preheater 23 heats the liquid material to a temperature just before vaporization (lower than the boiling point).

[0033] With the vaporizer 2 configured as described above, the liquid material introduced from the liquid material introduction port P1 of the main body block 5 flows through the flow path of the preheating block 231 of the preheater 23 and is preheated. The liquid material preheated by the preheater 23 is introduced into the vaporizer 21 by controlling the electromagnetic on-off valve 22. The liquid material is constantly stored in the vaporizer 21, and the liquid material is vaporized to continuously generate the material gas, which is continuously led to the mass flow controller 3.

[0034] Next, the mass flow controller 3 will be described. The mass flow controller 3 is provided downstream of the vaporizer 2 and controls the flow rate of the material gas generated by the vaporizer 2. Specifically, the mass flow controller 3 includes a fluid detection device 31 that detects the material gas flowing through the flow path, and a piezoelectric valve 32 that controls the flow rate of the material gas flowing through the flow path.

[0035] The fluid detection device 31 and the piezoelectric valve 32 are attached to the main body block 5. Specifically, the fluid detection device 31 and the piezoelectric valve 32 are attached to the main body block 5 on the downstream side of the vaporizer 2. The main body block B is installed in a semiconductor manufacturing line or the like with its longitudinal direction facing up and down (vertical direction) so that the liquid material inlet port P1 is located on the lower side and the material gas outlet port P2 is located on the upper side.

[0036] The fluid detection device 31 is, for example, a first pressure sensor 311 of a capacitance type that detects the pressure upstream of a fluid resistor (not shown) provided in the flow path of the main body block 5, and a second pressure sensor 312 of a capacitance type that detects the pressure downstream of the fluid resistor. Note that the fluid detection device 31 in this embodiment constitutes a differential pressure type flow sensor, but may also constitute a thermal type flow sensor using a pair of heating resistors.

[0037] The piezoelectric valve 32 controls the flow rate of the material gas flowing through the flow path of the main body block 5. This piezoelectric valve 32 has a valve body driven relative to a valve seat by a piezoelectric element 321. The piezoelectric valve 32 in this embodiment is of a so-called normally open type (normally open type), but may be of a normally closed type (normally closed type).

[0038] Next, the control device 4 will be described. The control device 4 is configured to control the operation of the vaporizer 2, the mass flow controller 3, etc., so as to supply a predetermined flow rate of gas to the chamber.

[0039] Specifically, the control device 4 is a computer having a CPU, memory, an AC / DC converter, input means, etc., and the CPU and its peripheral devices work together in accordance with a program stored in the memory to have functions as a set flow rate receiving unit 4a, a flow rate calculating unit 4b, a valve control unit 4c, etc., as shown in Fig. 2. In addition, the control device 4 controls the electromagnetic opening / closing valve 22 based on a detection signal from a liquid level sensor 213.

[0040] The set flow rate receiving unit 4a receives a set flow rate signal indicating a set flow rate input by a user via an input means such as a keyboard or transmitted from another device.

[0041] The flow rate calculation unit 4b acquires an output signal from the fluid detection device 31 and calculates the flow rate of the material gas output from the vaporization unit 2. The flow rate calculation unit 4b may be provided in the mass flow controller 3 and may constitute a flow rate sensor together with the fluid detection device 31.

[0042] The valve control unit 4c controls the piezo valve 32 based on the set flow rate and the measured flow rate calculated by the flow rate calculation unit 4b, and here outputs a drive signal to the piezo valve 32 to feedback control the valve opening so that the measured flow rate becomes the set flow rate.

[0043] <2. Piezo element life diagnosis function> Thus, the control device 4 of this embodiment has a piezoelectric element diagnostic function for diagnosing the piezoelectric element incorporated in the piezoelectric valve 32. That is, the control device 4 is provided with the function of the piezoelectric element diagnostic device 10.

[0044] Specifically, the control device 4 performs functions such as a drive information acquisition unit 4d, a life calculation unit 4e, a life related data storage unit 4f, a comparison unit 4g, and an alarm output unit 4h in accordance with a piezoelectric element diagnosis program stored in the memory.

[0045] The drive information acquisition unit 4d acquires drive information such as the drive history of the piezoelectric element 321. The drive information acquisition unit 4d acquires drive information at a predetermined sampling time (for example, every 100 msec). The drive information in this embodiment is the drive voltage applied to the piezoelectric element 321 and the temperature of the piezoelectric element 321.

[0046] Here, the drive voltage can be acquired from the valve control unit 4c or a drive circuit (not shown). The temperature of the piezoelectric element 321 can be acquired from a temperature sensor (not shown) provided around the piezoelectric element 321. The temperature of the piezoelectric element 321 may be the temperature of the piezoelectric element 321 itself, the ambient temperature of the piezoelectric element 321, the temperature of the piezo valve 32, the ambient temperature of the piezo valve 32, or the like.

[0047] The life calculation unit 4e calculates, based on the drive information, the consumed life or the remaining life of the piezoelectric element 321. The life calculation unit 4e of the present embodiment calculates the consumed life or the remaining life of the piezoelectric element 321 based on at least one of the drive voltage of the piezoelectric element 321 or the temperature of the piezoelectric element 321.

[0048] Here, the lifespan of the piezoelectric element 321 includes a total lifespan, which is a lifespan from the start of use (first use after shipment), or a unit lifespan, which is a lifespan per unit time. The lifespan is the time consumed (operating time) or the ratio of consumption (the ratio to the expected lifespan), etc. The operating time includes the time the piezoelectric element is simply operated, or a converted operating time converted when used under certain driving conditions (driving voltage, driving temperature, etc.). The lifespan of this embodiment is calculated from a standard mean time to failure (MTTFs) previously obtained by a reliability test, as described later. The remaining lifespan is the remaining time (operating time) or the remaining ratio (the ratio to the expected lifespan), etc., calculated from an integrated lifespan (total lifespan).

[0049] Specifically, the life calculation unit 4e calculates the consumed life or the remaining life based on the previously acquired expected life and driving information of the piezoelectric element 321. The life calculation unit 4e of this embodiment calculates the consumed life or the remaining life based on the previously acquired expected life, the driving voltage of the piezoelectric element 321, and the temperature of the piezoelectric element 321. Here, the previously acquired expected life is a standard mean time to failures (MTTFs) obtained in advance by a reliability test.

[0050] Furthermore, the life calculation unit 4e calculates the consumed life or remaining life for each interval period (e.g., 1 hour) including a plurality of sampling times (100 msec). The interval period may be the same every time, may be different every time, or may be different depending on the elapsed time from the start of use.

[0051] Furthermore, the life calculation unit 4e calculates the consumed life or the remaining life by using a representative value of the plurality of pieces of driving information (driving voltage and temperature) included in each interval period. Here, the representative value of the plurality of pieces of driving information may be an average value, a median value, or a calculated value obtained from the plurality of pieces of driving information.

[0052] Then, the life calculation unit 4e calculates the unit consumption life, which is the consumption life per unit time in each interval period, for each interval period. Specifically, the life calculation unit 4e calculates the unit consumption life (hereinafter, MTTFm) defined by the following formula. Note that MTTFm indicates the ratio of the time (operating time) consumed in the interval period of the piezoelectric element 321 to the expected life (mean time to failure) taking into account the usage status of the piezoelectric element 321.

[0053]

number

[0054] T int is the time interval [hour], which is 1 hour in this embodiment. Also, MTTFs is the standard mean time to failure obtained in advance by a reliability test.

[0055] Av(m) is the representative value (V R ) where the acceleration coefficient Av is, for example, (V0 / V R ) k1 V0 is the standard voltage when determining the standard mean time to failure. k1 is a coefficient set by the user.

[0056] At(m) is the representative value of multiple temperatures included in the mth interval (T R ) is the acceleration coefficient obtained by the following equation. Here, the acceleration coefficient At is, for example, k2 (T0-T) / 10 T0 is the standard temperature when determining the standard mean time to failure. k2 is a coefficient set by the user. In addition, in calculating MTTFm, a preset fixed value may be used for either the driving voltage or the temperature.

[0057] Then, the life calculation unit 4e sums up the MTTFm calculated for each interval period. This sum (hereinafter, MTTFc) represents the total consumed life from the start of use of the piezoelectric element 321, and is expressed by the following formula. That is, the life calculation unit 4e of this embodiment calculates the following MTTFc for each interval period. Note that MTTFc indicates the ratio of the total time consumed by the piezoelectric element 321 (total operating time) to the expected life (mean time to failure) taking into account the usage status of the piezoelectric element 321.

[0058]

number

[0059] When the above MTTFc is 1, the expected lifespan (mean time to failure) taking into account usage conditions has been reached.

[0060] Furthermore, the life calculation unit 4e can also output and display the calculated unit consumption life (MTTFm) or total consumption life (MTTFc) on a display of a user terminal, etc. Here, by outputting the calculated unit consumption life (MTTFm), it becomes possible to judge the usage status and grasp the tendency of the piezoelectric element 321.

[0061] The life-related data storage unit 4f stores various data necessary for life diagnosis of the piezoelectric element 321. The life-related data in this embodiment is configured, for example, by a non-volatile memory.

[0062] Specifically, the life-related data storage unit 4f stores the driving voltage applied to the piezoelectric element 321, the temperature of the piezoelectric element 321, the coefficients (k1, k2, etc.) of MTTFs, MTTFm, MTTFc, Av, and At, and the thresholds of the alarm output and error output described later.

[0063] Here, the drive voltage stored is a representative value of the drive voltage included in each interval period or the immediately preceding interval period. The temperature of the piezoelectric element 321 stored is a representative value of the temperature included in each interval period or the immediately preceding interval period. These representative values ​​of the drive voltage and temperature are stored every interval period (e.g., every hour). The drive voltage or temperature stored may be a value at each sampling time instead of a representative value. Furthermore, when a fixed value is used for the drive voltage or temperature in the life calculation unit 4e, the fixed value is stored.

[0064] The MTTFs stored is a standard value determined in advance by a reliability test. The MTTFm stored is the previously saved value. The MTTFm for each interval period may be stored. Furthermore, the MTTFc stored is the total value up to the previous time. These MTTFm and MTTFc are stored every interval period (e.g., every hour).

[0065] The comparison unit 4g compares the consumed life or remaining life calculated by the life calculation unit 4e with a predetermined threshold. In this embodiment, the comparison unit 4g compares the calculated total consumed life with a predetermined threshold. The comparison unit 4g also compares the calculated total consumed life with a first threshold for outputting an alarm and a second threshold for outputting an error.

[0066] Since the life calculation unit 4e of this embodiment calculates the total consumed life (MTTFc), the first threshold and the second threshold are thresholds for the total consumed life (MTTFc). For example, the first threshold for outputting an alarm is 0.6, and the second threshold for outputting an error is 0.8. The comparison unit 4g compares the MTTFc with each threshold at each interval (for example, every hour).

[0067] The warning output unit 4h outputs an alarm or an error based on the comparison result (MTTFc≧first threshold, MTTFc≧second threshold) of the comparison unit 4g. A specific example of the warning output unit 4h may be configured to output a signal to control an alarm device that emits sound or light, or may display an alarm or an error on a display of a user terminal or the like.

[0068] <3. Effects of this embodiment> As described above, according to the vaporization system 100 of this embodiment, the consumed life or remaining life of the piezoelectric element 321 is calculated based on the drive information, so that even if the use state of the piezoelectric element changes, the piezoelectric element 321 can be replaced or maintained at an appropriate timing. Here, the consumed life or remaining life of the piezoelectric element 321 is calculated using a standard mean time to failure (MTTFs) obtained in advance by a reliability test, so that the consumed life or remaining life can be obtained more accurately. In addition, the consumed life or remaining life is calculated based on the drive voltage or temperature that is likely to affect the life of the piezoelectric element 321, so that the consumed life or remaining life can be obtained more accurately.

[0069] <4. Other embodiments> For example, the life calculation unit 4e may obtain the total consumed life of the piezoelectric element 321 in terms of time instead of a percentage. In this case, the time used is the sum of the interval periods in the above embodiment. For example, if the interval period is set to every hour, the number of intervals is recorded, and the time used (simply the time the piezoelectric element was operated) can be calculated.

[0070] In order to calculate the total consumed life more accurately, the life calculation unit 4e can also calculate a converted operating time converted when used under certain driving conditions (driving voltage, driving temperature, etc.). Specifically, the life calculation unit 4e can calculate the converted operating time as the consumed life by multiplying the mean time to failure (MTTFr) when used under certain driving voltage and temperature by the total consumed life (MTTFc) obtained by Equation 2.

[0071] Further, the life calculation unit 4e in the above embodiment calculates the total consumed life (MTTFc) of the piezoelectric element 321, but the remaining life (1-MTTFc) may be calculated by subtracting the total consumed life (MTTFc) from 1. In this case, the calculated remaining life is a percentage.

[0072] Furthermore, the life calculation unit 4e may calculate the time as the remaining life. For example, when the MTTFm is 0.4, the remaining life is 0.6, and this 0.6 needs to be converted into time. In this case, the remaining time can be calculated using the MTTFm calculation formula and, for example, the representative value of the driving voltage and the representative value of the temperature in the most recent interval period. When the remaining life (ratio) is 0.6, the remaining time α can be calculated by the following formula. 0.6=α / (MTTFs×Av×At) Here, Av and At are the representative values ​​of the driving voltage and the temperature in the most recent interval. Also, Av and At can be the representative values ​​of the driving voltage and the temperature in any past interval. Alternatively, preset fixed values ​​can be used for Av and At.

[0073] The life calculation unit 4e in the above embodiment calculates both the unit consumption life and the total consumption life of the piezoelectric element 321, but may be configured to calculate only either the unit consumption life or the total consumption life. Even if the configuration calculates only the unit consumption life, it is possible to judge the usage status and grasp the tendency of the piezoelectric element 321 by observing the change in the unit consumption life.

[0074] In the above embodiment, the configuration includes the comparison unit 4g and the warning output unit 4h, but the configuration may not include these. In this case, the total consumed life or remaining life calculated by the life calculation unit 4e is output to a display of a user terminal or the like, so that the user can replace or maintain the piezoelectric element at an appropriate time.

[0075] In addition, the expected lifespan may be calculated from the number of times the piezo valve 32 (piezo element 321) is driven, the driving time, or the accumulated driving amount (accumulated movement amount), and the lifespan calculation unit 4e may calculate the consumed lifespan or remaining lifespan based on the expected lifespan and the driving information.

[0076] Furthermore, the control device 4 (piezo element diagnosis device 10) may be configured to include a replacement signal receiving unit 4i that receives a replacement signal indicating that the piezoelectric element to be diagnosed has been replaced, and a reset unit 4j that resets the consumed life or remaining life calculated by the life calculation unit 4e upon receiving the replacement signal, as shown in Fig. 3. The replacement signal may be input by a user using an input means.

[0077] 3, the control device 4 (piezo element diagnosis device 10) may be configured to include an automatic recognition unit 4k that automatically recognizes the replaced piezo element 321 when the piezo element 321 to be diagnosed is replaced, instead of the replacement signal receiving unit 4i. When the piezo valve 32 or the mass flow controller 3 (fluid control device) having the piezo element 321 is replaced, the automatic recognition unit 4k may automatically recognize the replaced piezo element 321 by receiving identification information transmitted from the replaced piezo valve 32 or the mass flow controller 3. In these cases, the life calculation unit 4e calculates the consumed life or remaining life of the replaced piezo element 321 automatically recognized by the automatic recognition unit 4k. In addition, when the automatic recognition unit 4k automatically recognizes the piezo element 321, the life-related data may be managed for each identification information without resetting the information by the reset unit 4j.

[0078] Furthermore, the control device 4 (piezo element diagnostic device 10) may further include a life prediction unit 4m that calculates a future consumed life or remaining life based on a change in the consumed life or remaining life obtained by the life calculation unit 4e, as shown in FIG. 4. Specifically, the life prediction unit 4m calculates a future consumed life or remaining life based on a driving history such as the driving frequency of the piezoelectric element in addition to the change in the consumed life or remaining life calculated by the life calculation unit 4e. This life prediction unit 4m can also predict, for example, a period until each threshold value used in the comparison unit is reached. Specifically, assuming that use will continue with driving information for a certain interval period, for example, if the current consumed life (MTTFc) is 0.5, it can predict that it will take one month to reach the first threshold value (0.6). The life prediction unit 4m can also predict a period until the mean time to failure is reached. Furthermore, the life prediction unit 4m can be configured to issue an alarm command to the alarm output unit 4h.

[0079] Moreover, the vaporization method may be other vaporization methods such as a heating method in addition to bubbling.

[0080] In addition, although the vaporizer 2 and the mass flow controller 3 in the above embodiment are configured to be attached to the main body block 5, the main body block 5 may be configured to be separate from each other. Also, the vaporizer 2 and the mass flow controller 3 may be configured to be connected by piping.

[0081] Furthermore, although the vaporization system in the above embodiment supplies the material gas to a chamber of a semiconductor manufacturing apparatus, it may also supply the material gas to other chambers.

[0082] Although the piezoelectric element diagnostic device in the above embodiment is incorporated in the vaporization system, it may be a separate device (module) from the vaporization system. Also, the piezoelectric element diagnostic device may be a separate device (module) from the fluid control device.

[0083] Furthermore, the piezoelectric element diagnostic device may diagnose piezoelectric elements used in applications where they are driven by the application of voltage, as well as piezoelectric elements used in applications where they output voltage when pressure is applied.

[0084] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention. [Explanation of symbols]

[0085] 100···Evaporation system 2. Evaporation section 3. Fluid control device (mass flow controller) 32 Piezo valve 321 Piezo element 10 Piezo element diagnostic device 4. Control device 4c Valve control section 4d Driving information acquisition section 4e...Life calculation section 4g Comparison section 4h...Alarm output section 4i...Exchange signal reception section 4j Reset section 4k...Automatic recognition section 4l...Life prediction section

Claims

1. A piezoelectric element diagnostic device for diagnosing a piezoelectric element incorporated in a device, a drive information acquisition unit that acquires drive information of the piezoelectric element; and a life calculation unit that calculates a consumed life or a remaining life of the piezoelectric element based on the drive information.

2. The piezoelectric element diagnostic device according to claim 1 , wherein the life calculation unit calculates the consumed life or the remaining life based on an expected life of the piezoelectric element acquired in advance and the driving information.

3. the drive information includes at least one of a drive voltage of the piezoelectric element or a temperature of the piezoelectric element, The piezoelectric element diagnostic device according to claim 2 , wherein the life calculation unit calculates the consumed life or the remaining life based on the expected life and at least one of a drive voltage of the piezoelectric element and a temperature of the piezoelectric element.

4. The piezoelectric element diagnostic device according to claim 1 , wherein the life calculation unit calculates the total consumed life from the start of use or the remaining life for each interval period.

5. The piezoelectric element diagnostic device according to claim 1 , wherein the life calculation unit calculates a unit consumed life, which is a consumed life per unit time in each interval period.

6. the drive information acquisition unit acquires the drive information at each sampling time, The piezoelectric element diagnostic device according to claim 1 , wherein the life calculation unit calculates the consumed life or the remaining life using a representative value of a plurality of pieces of the driving information.

7. a comparison unit that compares the consumed lifespan or the remaining lifespan calculated by the lifespan calculation unit with a predetermined threshold value; The piezoelectric element diagnostic device according to claim 1 , further comprising an alarm output unit that outputs an alarm based on a comparison result of the comparison unit.

8. a replacement signal receiving unit that receives a replacement signal indicating that the piezoelectric element to be diagnosed has been replaced; The piezoelectric element diagnostic device according to claim 1 , further comprising: a reset unit that resets the consumed life or the remaining life calculated by the life calculation unit when the replacement signal is received.

9. The device further includes an automatic recognition unit that automatically recognizes the replaced piezoelectric element when the piezoelectric element to be diagnosed is replaced, The piezoelectric element diagnostic device according to claim 1 , wherein the life calculation unit calculates a consumed life or a remaining life of the replaced piezoelectric element.

10. The piezoelectric element diagnostic device according to claim 1 , further comprising a life prediction unit that calculates a future consumed life or a remaining life based on a change in the consumed life or the remaining life obtained by the life calculation unit.

11. A piezoelectric element diagnostic method for diagnosing a piezoelectric element incorporated in an apparatus, comprising: Acquire driving information of the piezoelectric element; A piezoelectric element diagnosis method for calculating a consumed life or a remaining life of the piezoelectric element based on the drive information.

12. A piezoelectric element diagnostic program for diagnosing a piezoelectric element incorporated in an apparatus, a function as a drive information acquisition unit that acquires drive information of the piezoelectric element; and a function as a life calculation unit that calculates a consumed life or a remaining life of the piezoelectric element based on the drive information.

13. a piezo valve in which a valve element is driven relative to a valve seat by a piezo element; a valve control unit that controls the opening degree of the piezo valve; A fluid control device comprising the piezoelectric element diagnostic device according to any one of claims 1 to 10.

14. a vaporizing unit that vaporizes the liquid raw material; a fluid control device for controlling the flow rate of the gas vaporized by the vaporizing unit; A vaporization system comprising the piezoelectric element diagnostic device according to any one of claims 1 to 10.

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