Fluid measurement apparatus, fluid measurement method, and substrate processing apparatus

Abstract

To provide a technique capable of measuring a flow direction and a flow velocity in a short time.SOLUTION: A fluid measurement apparatus 1 includes a piezoelectric sensor 3 and an arithmetic unit 7. The piezoelectric sensor 3 has a plurality of structures 4 arranged two-dimensionally on an upper portion thereof, and converts pressures received by the plurality of structures 4 into voltage values. The arithmetic unit 7 processes a two-dimensional voltage distribution output from the piezoelectric sensor 3. The arithmetic unit 7 is capable of executing a flow direction calculation process S1 and a flow velocity calculation process S2. In the flow direction calculation process S1, the arithmetic unit 7 calculates a flow direction by using voltage values of regions corresponding to positions of the respective structures 4 in the voltage distribution. In the flow velocity calculation process S2, the arithmetic unit 7 calculates a movement amount of a distribution pattern of voltage values between a first voltage distribution obtained at a first time t1 and a second voltage distribution obtained at a second time t2, and calculates a flow velocity from the calculated movement amount d.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The subject matter disclosed herein relates to a fluid measurement device, a fluid measurement method, and a substrate processing apparatus. [Background technology]

[0002] A known example of a sensor capable of measuring wind speed and direction is the thermal flow sensor described in Patent Document 1. The sensor in Patent Document 1 is configured to calculate the flow speed from a heater element, an ambient temperature measuring element, and the heat generation amount of the heater. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-87768 [Non-patent literature]

[0004] [Non-Patent Document 1] Holt Plan Sensor Specifications "HWS-19-ONE Specifications" Rev.0.80 [Non-patent document 2] Mizuki Ohira et al., "Proposal and Verification of Shear Force Image Sensor by Forming Microstructures on a CMOS Sensor Array." Proceedings of the Symposium "Sensors, Micromachines and Application Systems," Sensors and Micromachines Division, Institute of Electrical Engineers of Japan, 39 (2022): 6p. Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order for a thermal flow sensor to stably and continuously calculate flow velocity, a certain amount of time is required for the heater element to cool or warm up. As an example, the thermal flow sensor described in Non-Patent Document 1 has a flow velocity measurement cycle of 250 ms. As such, it has been difficult for a thermal flow sensor to calculate flow direction and velocity in a short time.

[0006] An object of the present invention is to provide a technique that can measure flow direction and flow velocity in a short time. [Means for solving the problem]

[0007] In order to solve the above problem, a first aspect is a fluid measurement device that measures the flow direction and flow velocity of a fluid, and has a plurality of structures that are two-dimensionally arranged formed on top of it, and is equipped with a piezoelectric sensor that converts the pressure received by the plurality of structures into a voltage value, and a calculation unit that processes the two-dimensional voltage distribution output from the piezoelectric sensor, wherein the calculation unit is capable of executing a flow direction calculation process that calculates the flow direction using voltage values ​​of an area corresponding to the position of each of the structures in the voltage distribution, and a flow velocity calculation process that calculates the amount of movement of the distribution pattern of voltage values ​​between a first voltage distribution obtained at a first time and a second voltage distribution obtained at a second time after the first time, and calculates the flow velocity from the calculated amount of movement.

[0008] A second aspect is the fluid measurement device of the first aspect, wherein the calculation unit calculates the movement amount in the flow velocity calculation process by using the flow direction calculated by the flow direction calculation process as the movement direction of the distribution pattern.

[0009] A third aspect is the fluid measurement device of the second aspect, wherein the calculation unit uses, in the flow velocity calculation process, the voltage distribution used to calculate the flow direction in the flow direction calculation process as the first voltage distribution.

[0010] A fourth aspect is the fluid measurement device of the first or second aspect, wherein the calculation unit divides the voltage distribution into a plurality of inspection areas in the flow velocity calculation process and calculates the movement amount for each of the plurality of inspection areas.

[0011] A fifth aspect is the fluid measurement device of the first or second aspect, wherein the calculation unit calculates the amount of movement by a brightness difference accumulation method in the flow velocity calculation process.

[0012] A sixth aspect is a fluid measurement method for measuring the flow direction and flow velocity of a fluid, comprising the steps of: a) converting the pressure received by a plurality of two-dimensionally arranged structures into a two-dimensional voltage distribution using a piezoelectric sensor; b) calculating the flow direction using voltage values ​​of an area corresponding to the position of each of the structures in the voltage distribution; and c) calculating the amount of movement of the distribution pattern of voltage values ​​between a first voltage distribution obtained at a first time and a second voltage distribution obtained at a second time after the first time, and calculating the flow velocity from the calculated amount of movement.

[0013] A seventh aspect is a substrate processing apparatus comprising a substrate holding part for holding a substrate, a cup surrounding the substrate holding part, and a fluid measuring device of the first or second aspect for measuring the flow direction and flow velocity of a fluid around the cup. [Effects of the Invention]

[0014] According to the first to seventh aspects, the pressure received by each structure can be instantaneously output as a voltage value, so that the flow direction and flow velocity can be calculated in a short time.

[0015] According to the second aspect, the amount of calculation of the movement amount can be reduced by using a flow direction calculated in advance.

[0016] According to the third aspect, the amount of movement of the distribution pattern of the voltage values ​​can be calculated appropriately.

[0017] According to the fourth aspect, it is possible to detect a shift in the distribution pattern of voltage values.

[0018] According to the fifth aspect, similar portions between the voltage distribution at the first time point and the voltage distribution at the second time point can be identified with high accuracy by pattern matching using the brightness difference accumulation method, and therefore the amount of movement can be calculated appropriately. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a diagram showing a configuration of a fluid measurement device according to an embodiment; [Figure 2]FIG. 2 is a view showing the top surface of the detector. [Figure 3] FIG. 10 is a diagram showing a two-dimensional voltage distribution detected by a piezoelectric sensor. [Figure 4] FIG. 10 is a diagram showing the flow of a fluid measurement process. [Figure 5] FIG. 5 is a diagram showing a detailed flow of the flow direction calculation process shown in FIG. [Figure 6] FIG. 10 is a diagram conceptually illustrating the flow of a flow direction calculation process. [Figure 7] FIG. 5 is a diagram showing a detailed flow of the flow velocity calculation process shown in FIG. 4. [Figure 8] FIG. 10 is a diagram conceptually illustrating a flow velocity calculation process. [Figure 9] 1 is a substrate processing apparatus equipped with the fluid measuring device shown in FIG. [Figure 10] FIG. 2 is a diagram showing a printing device equipped with the fluid measurement device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary to facilitate understanding.

[0021] 1 and the following figures, arrows indicating the mutually perpendicular X, Y, and Z directions are appropriately shown for the sake of convenience. In the following explanation, the direction indicated by the tip of each arrow is the positive (+) direction, and the opposite direction is the negative (-) direction.

[0022] <1. Embodiment> 1 is a diagram showing the configuration of a fluid measurement device 1 according to an embodiment. The fluid measurement device 1 is a device that measures, for example, the flow direction and flow velocity of a fluid. In the following explanation, a case will be described in which the flow direction (wind direction) and flow velocity (wind speed) of a gas are measured using the fluid measurement device 1, but it is also possible to measure a liquid in the same way as a gas.

[0023] As shown in FIG. 1, the fluid measurement device 1 has a piezoelectric sensor 3 and a calculation unit 7. The piezoelectric sensor 3 has a plurality of structures 4 on its upper portion. The piezoelectric sensor 3 is a device that converts the force received by the plurality of structures 4 from the fluid into a two-dimensional voltage distribution. As the piezoelectric sensor 3, for example, a shear force image sensor described in Non-Patent Document 2 can be used.

[0024] FIG. 2 is a diagram showing the top surface of the piezoelectric sensor 3. The structures 4 are formed of, for example, PET resin. As shown in FIG. 2, the piezoelectric sensor 3 has a shape that extends on a plane parallel to the X and Y directions that are orthogonal to each other. A plurality of structures 4 are two-dimensionally arranged on the top surface of the piezoelectric sensor 3 (more specifically, on the surface of the metal layer 51). Specifically, the plurality of structures 4 are regularly arranged at regular intervals in the X and Y directions.

[0025] The piezoelectric sensor 3 has, from top to bottom, a metal layer 51, a piezoelectric layer 53, and a CMOS sensor array 55. The metal layer 51 is a thin film made of, for example, gold (Au). The piezoelectric layer 53 is formed of, for example, polyvinylidene fluoride (PVDF) resin. The CMOS sensor array 55 has a plurality of sensor pixels 551 arranged two-dimensionally. The number of sensor pixels 551 is not particularly limited, but is, for example, 256 pixels by 256 pixels.

[0026] When no force is applied to the piezoelectric layer 53, the piezoelectric layer 53 of the piezoelectric sensor 3 is in an electrically balanced state due to external floating charges. On the other hand, when the structure 4 is subjected to pressure, force is applied to the piezoelectric layer 53. This changes the magnitude of the spontaneous polarization of the piezoelectric layer 53, generating a positive charge on one side and a negative charge on the other. Each sensor pixel 551 of the CMOS sensor array 55 reads this change in charge in the piezoelectric layer 53 as a change in surface potential. In this way, the piezoelectric sensor 3 converts and detects changes in physical force perpendicular to the surface into an electrical signal. Note that when the piezoelectric layer 53 is compressed (i.e., pushed from above) and stretched (pulled upward), the charges generated on both sides are reversed, and therefore the output from the CMOS sensor array 55 is also reversed in positive and negative.

[0027] The analog signal of the voltage value output from each sensor pixel 551 of the CMOS sensor array 55 is converted into a digital signal by the AD converter 33 and output to the calculation unit 7. That is, the piezoelectric sensor 3 outputs the voltage distribution data to the calculation unit 7.

[0028] The calculation unit 7 is a device that processes the voltage distribution data output from the AD converter 33. The calculation unit 7 is, for example, a computer, and has a processor 71 and a memory 73. The processor 71 includes a circuit such as a CPU (Central Processing Unit). The memory 73 includes, for example, a main storage device such as a RAM (Random-Access Memory) and an auxiliary storage device such as an HDD (Hard Disc Drive) or an SSD (Solid State Drive). The memory 73 is electrically connected to the processor 71 via a bus wiring.

[0029] A computer program P is stored in the memory 73. The processor 71 executes the computer program P stored in the memory 73 to perform arithmetic processing for calculating flow direction and flow velocity. The computer program P may be stored in the memory 73 of the calculation unit 7 by reading the computer program P recorded on a recording medium such as a flash memory or optical media with a dedicated reading device. The computer program P may also be stored in the memory 73 via a network line such as the Internet.

[0030] The calculation unit 7 has a display 75 and an input device 77. The display 75 is a device that displays various images, and is specifically a liquid crystal display. The input device 77 is a device that accepts input operations from the user, and is, for example, a mouse or a keyboard. Note that the display 75 may have a touch panel, so that the display 75 can function as an input device.

[0031] FIG. 3 shows a two-dimensional voltage distribution detected by the piezoelectric sensor 3. Each structure 4 is disposed above a plurality of sensor pixels 551 adjacent to it in the X and Y directions. Therefore, when one structure 4 receives a force (shear force) from the fluid in the XY plane direction parallel to the XY plane (plane parallel to the X and Y directions), the piezoelectric layer 53 directly below the structure 4 generates points that are compressed downward perpendicular to the XY plane (-Z direction) and points that are stretched upward perpendicular to the XY plane (+Z direction) in accordance with the force received by the structure 4. Therefore, by analyzing the voltage value output from the sensor pixel 551 disposed directly below the structure 4, the direction of the force received by the structure 4 in the XY plane direction can be detected.

[0032] In this example, one structure 4 is disposed on four sensor pixels 551 adjacent in the X and Y directions. Therefore, when a force is applied to one structure 4, four sensor pixels 551 detect a voltage value, as shown in Fig. 3. For example, when the structure 4 receives a force in the +X direction, two sensor pixels 551 on the +X side detect a voltage value corresponding to the force in the vertical downward direction (-Z direction). Furthermore, two sensor pixels 551 on the -X side detect a voltage value corresponding to the force in the vertical upward direction (+Z direction).

[0033] <Fluid measurement method> Next, a description will be given of the fluid measurement process performed by the fluid measurement device 1. Fig. 4 is a diagram showing the flow of the fluid measurement process. In the following description, a case where the wind direction and wind speed of a gas are measured will be described. However, the same can be done for liquid measurement.

[0034] The calculation unit 7 first calculates the wind direction in a flow direction calculation process S1. Next, the calculation unit 7 calculates the wind speed in a flow speed calculation process S2. The wind direction calculated in the flow direction calculation process S1 is used in the flow speed calculation process S2. The calculation unit 7 then stores the wind direction and wind speed calculated in the flow direction calculation process S1 and the flow speed calculation process S2 in the memory 73. Next, the detailed procedures of the flow direction calculation process S1 and the flow speed calculation process S2 will be described.

[0035] <Flow direction calculation process procedure> FIG. 5 is a diagram showing a detailed flow of the flow direction calculation process S1 shown in FIG. 4. FIG. 6 is a diagram conceptually showing the flow of the flow direction calculation process. In the flow direction calculation process S1, the calculation unit 7 first acquires sensor data DS (FIG. 5; step S11). As shown in FIG. 6, the sensor data DS is image data showing a two-dimensional voltage distribution output from the piezoelectric sensor 3. The sensor data DS is acquired, for example, at a predetermined sampling period.

[0036] When the calculation unit 7 acquires the sensor data DS, it acquires the voltage values ​​of the area corresponding to the position of each structure 4 (FIG. 5; step S12). Specifically, as shown in FIG. 6, the calculation unit 7 acquires four voltage values ​​of four sensor pixels 551 (hereinafter also referred to as "corresponding pixel group") corresponding to each structure 4 by applying mask data DM indicating the position of the structure 4 to the sensor data DS. Then, by regarding the four voltage values ​​as vectors in the vertical direction, the calculation unit 7 calculates the normal vector of the plane when the corresponding pixel group is regarded as one plane (FIG. 5; step S13). Specifically, by focusing on one corresponding pixel group, the calculation unit 7 calculates the X coordinate x of the four sensor pixels 551 included in that corresponding pixel group. k and the Y coordinate y k The calculation unit 7 also calculates the voltage values ​​of the four sensor pixels 551 by calculating the Z coordinate z k By treating it as such, the four coordinates (x k ,y k ,z k ) is set as a virtual plane passing through the points . Then, the calculation unit 7 calculates the normal vector (unit normal vector) of the virtual plane as the normal vector of the corresponding pixel group of interest. Note that the normal vector can be calculated by, for example, principal component analysis.

[0037] After calculating the normal vector for each corresponding pixel group, the calculation unit 7 obtains the vector value of each normal vector in the XY plane direction (FIG. 5: step S14). Then, the calculation unit 7 calculates the rotation angle from a predetermined reference line around the Z axis for a resultant vector Vr obtained by combining all the obtained vector values ​​(FIG. 5; step S15). The wind direction is calculated by the above procedure. Next, the procedure of the flow velocity calculation process S2 will be described.

[0038] <Flow velocity calculation process procedure> Fig. 7 is a diagram showing a detailed flow of the flow velocity calculation process S2 shown in Fig. 4. Fig. 8 is a diagram showing a concept of the flow velocity calculation process S2.

[0039] When gas flows in a specific wind direction above the piezoelectric sensor 3, the gas sequentially collides with multiple structures 4 aligned in that wind direction. As a result, the distribution pattern of voltage values ​​detected by the piezoelectric sensor 3 also moves in that wind direction. Therefore, in this embodiment, template matching is performed between an image (hereinafter referred to as the "first frame image F1") represented by the sensor data DS (first voltage distribution) at a first time t1 used to calculate the wind direction in the flow direction calculation process S1, and an image (hereinafter referred to as the "second frame image F2") represented by the sensor data DS (second voltage distribution) at a second time t2 after the first time t1. Then, based on the results of this template matching, the amount of movement of the distribution pattern is calculated, and the wind speed is further calculated from the amount of movement.

[0040] Specifically, when the calculation unit 7 starts the flow velocity calculation process S2, it first acquires a first frame image F1 and a second frame image F2 (FIG. 7; step S20). The first frame image F1 is an image represented by the sensor data DS acquired in step S11 of the flow direction calculation process S1 in order to calculate the wind direction. The second frame image F2 is an image acquired, for example, at a second time t2 immediately after the first frame image F1. In this case, the time difference between the first time t1 and the second time t2 coincides, for example, with the sampling period of the sensor data DS.

[0041] Next, an inspection area AE is set on the first frame image F1 (FIG. 7; step S21). The size of the inspection area AE (Npix×Mpix) is smaller than the size of the first frame image F1. In this example, the calculation unit 7 divides the first frame image F1 into four equal parts to set four inspection areas AE1, AE2, AE3, and AE4, as shown in FIG. 8. The inspection areas AE1 to AE4 are all the same size, which is 128pix×128pix. Furthermore, the calculation unit 7 calculates a measurement point PM (coordinates (x e ,y e)) is determined. The measurement point PM is, for example, the center point of each inspection area AE. The calculation unit 7 processes the multiple inspection areas AE1 to AE4 one by one. Below, first, the case where the inspection area AE1 is processed will be described.

[0042] Next, the calculation unit 7 sets a search area AS1 in the second frame image F2 (FIG. 7; step S22). The search area AS1 includes at least a measurement point PM1 (coordinates: (x e1 ,y e1 )) and has a rectangular shape extending in the wind direction calculated by the flow velocity calculation process S2. The search area AS1 is a similarity calculation target area calculated based on the wind direction indicated by the first frame image F1. For example, in the example shown in Fig. 8, the wind direction is the +X direction, so the search area AS1 is an area extending to the +X side of the measurement point PM1.

[0043] Next, the calculation unit 7 sets a candidate area AC1 centered on a point within the search area AS1 in the second frame image F2 (FIG. 7; step S23). The size of the candidate area AC1 is the same as the size (Npix × Mpix) of the inspection area AE1.

[0044] Next, the calculation unit 7 calculates the luminance difference cumulative value C between the inspection area AE1 in the first frame image F1 and the candidate area AC1 in the second frame image F2. a (FIG. 7; step S24). a is expressed by the following equation:

[0045]

number

[0046] The calculation unit 7 calculates the luminance difference cumulative value C for all points in the search area AS1. a It is then determined whether the luminance difference cumulative value C aIf there are any points for which the luminance difference cumulative value C has not been calculated, the calculation unit 7 returns to step S23 and calculates the luminance difference cumulative value C for the next point. a The cumulative brightness difference C of all points in the search area AS1 is calculated. a If calculated (Yes in step S25), the calculation unit 7 calculates the luminance difference cumulative value C a is determined (FIG. 7; step S26). This determines the center point G of the candidate area AC1 that is most similar to the inspection area AE1.

[0047] The calculation unit 7 determines whether or not processing has been performed for all inspection areas AE1 to AE4 (FIG. 7; step S27). Here, since inspection areas AE2 to AE4 have not been processed, the calculation unit 7 returns to step S21 and performs the processing of steps S21 to S26 for any of the remaining inspection areas AE2 to AE4. As a result, the center point G is determined for each of all inspection areas AE1 to AE4.

[0048] Of the inspection areas AE1 to AE4 in the first frame image F1, steps S21 to S26 may be skipped for inspection area AE where the voltage value of the voltage distribution does not exceed a predetermined threshold. This allows the processing to be omitted for inspection area AE where no change in voltage value is detected at the first time t1, thereby reducing the amount of calculation.

[0049] If it is determined in step S27 that processing has been completed for all inspection areas AE, the calculation unit 7 calculates the distance d from the measurement point PM to the center point G for each inspection area AE (FIG. 7: step S28). This distance d corresponds to the amount of movement of the distribution pattern detected in the first frame image F1. The calculation unit 7 then calculates the wind speed y by substituting the calculated distance d into the following equation (2) (FIG. 7: step S29).

[0050]

number

[0051] The wind speed y is calculated by the above procedure. By processing all of the inspection areas AE1 to AE4, four wind speeds y are obtained. In this case, the calculation unit 7 may determine one of the wind speeds y as the final wind speed y based on a threshold, for example, or may determine the average, median, or weighted average of several wind speeds y as the final wind speed y.

[0052] Next, the worst-case calculation amount of the flow direction calculation process S1 and the flow velocity calculation process S2 will be examined. The explanation will be given assuming that each variable has the value shown in Table 1 below.

[0053] [Table 1]

[0054] The worst case computational complexity for wind direction and speed, using Landau's O notation, is as follows: Wind direction calculation: O("Number of structure positions" x "Calculation of normal vectors" + "Sum of all normal vectors") = O(512 × "variance-covariance matrix calculation" + "Eigenvalue decomposition by Jacobi method" + "deriving the third eigenvector" + 512) =O(512×(16+3+1)+512) =O(10752) =O(1.1×10 4 ) Wind speed calculation: O("Maximum number of inspection areas to be inspected" x "Maximum relative position" x N x M) =O(2×128×128×128) =O(4194304) =O(4.2×10 6 )

[0055] The case where the amount of calculation required for wind speed calculation is the case where the wind blows along the X or Y direction. For example, when the wind blows along the +X direction, there are two areas that need to be inspected: inspection areas AE1 and AE3. In this case, the relative position of inspection area AE1 is (x e1 ,y e1 ) to (xe2 ,y e2 ), so the value is "128". In this case, a calculation load of O(128 x 128) is required to calculate the cumulative brightness difference value of the N x M area in the inspection area. Putting all this together, we get the worst-case calculation load for wind speed calculation mentioned above.

[0056] Since the clock frequency of a typical CPU is about 3 GHz, we will assume that the clock frequency of the arithmetic unit is 1 GHz. In other words, the computational complexity using Landau's O notation is O(10 9 ), it can be estimated that the calculation takes 1 second. Based on this idea, the computational complexity of this algorithm is O(1.1×10 4 +4.2×10 6 )=O(4.3×10 6 ), and the processing time is about 10 ms even with a margin. Therefore, it is possible to calculate wind speed and direction within 10 ms, which is sufficiently fast compared to the thermal sensor of Patent Document 1.

[0057] <Application examples of fluid measurement devices> FIG. 9 shows a substrate processing apparatus 10 equipped with the fluid measuring device 1 shown in FIG. The substrate processing apparatus 10 is a semiconductor cleaning apparatus for cleaning a semiconductor substrate W. The substrate processing apparatus 10 includes a substrate holding unit 101 for holding the semiconductor substrate W, annular cups 103 and 105 surrounding the substrate holding unit 101, and a nozzle 107 for discharging a liquid such as a chemical solution onto the semiconductor substrate W held by the substrate holding unit 101. The cup 103 is disposed outside the cup 105. The cups 103 and 105 can be raised and lowered by an elevating mechanism (not shown). The piezoelectric sensor 3 of the fluid measuring device 1 is disposed in the space between the cups 103 and 105. Here, the piezoelectric sensor 3 is attached to the inner surface of the cup 103, and is capable of measuring the flow direction and flow velocity around the cup 103.

[0058] Airflows within a semiconductor cleaning equipment can adversely affect the equipment's processes by interfering with the discharge of chemicals, scattering chemicals, or leaving chemicals from previous processes in the atmosphere when they should not be present. Therefore, it is necessary to measure the wind speed and direction within the equipment to determine where and during which process airflows are occurring. Because the piezoelectric sensor 3 of the fluid measuring device 1 is relatively small, it can quickly and accurately measure wind direction and speed even in narrow spaces such as the gap between the cups 103 and 105. The location where the piezoelectric sensor 3 is installed is not limited to the gap between the cups 103 and 105, but can be set anywhere, such as directly above the semiconductor substrate W.

[0059] Figure 10 is a diagram showing a printing device 11 equipped with the fluid measurement device 1 shown in Figure 1. The printing device 11 is an industrial printing machine, and is equipped with a conveying unit 111 such as rollers that conveys a long strip of rolled paper 9, and an inkjet 113 that ejects ink onto the rolled paper 9 conveyed by the conveying unit 111. The piezoelectric sensor 3 of the fluid measurement device 1 is disposed between the inkjet 113 and the rolled paper 9.

[0060] If an air current occurs between the inkjet 113 and the roll paper 9, it could have a negative effect on the ink ejection from the inkjet 113 or on the position where the ink lands on the roll paper 9. By installing the fluid measurement device 1 in the printing device 11, it becomes possible to quickly and accurately measure the direction and speed of the air current even in the narrow gap between the inkjet 113 and the roll paper 9.

[0061] <Effects> As described above, the fluid measurement device 1 according to the embodiment includes a piezoelectric sensor 3 and a calculation unit 7. The piezoelectric sensor 3 has a plurality of structures 4 arranged two-dimensionally formed thereon, and converts the pressure received by the structures 4 into voltage values. The calculation unit 7 processes the two-dimensional voltage distribution output from the piezoelectric sensor 3. The calculation unit 7 is capable of performing a flow direction calculation process S1 and a flow velocity calculation process S2. In the flow direction calculation process S1, the calculation unit 7 calculates the flow direction using the voltage values ​​of an area corresponding to the position of each structure 4 in the voltage distribution. In the flow velocity calculation process S2, the calculation unit 7 calculates the amount of movement d of the distribution pattern of the voltage values ​​between the first voltage distribution obtained at the first time t1 and the second voltage distribution obtained at the second time t2, and calculates the flow velocity from the calculated amount of movement d. This configuration allows the pressure received by each structure 4 to be instantaneously output as a voltage value, thereby enabling the flow direction and flow velocity to be calculated in a short time.

[0062] In the flow velocity calculation process S2, the calculation unit 7 calculates the movement amount d by using the flow direction calculated in the flow direction calculation process S1 as the movement direction of the distribution pattern. According to this configuration, by using the flow direction calculated in advance, the amount of calculation of the movement amount d can be reduced.

[0063] In the flow velocity calculation process S2, the calculation unit 7 uses the voltage distribution used for calculating the flow direction in the flow direction calculation process as the first voltage distribution. With this configuration, the amount of movement of the distribution pattern of voltage values ​​can be calculated appropriately.

[0064] In the flow velocity calculation process S2, the calculation unit 7 divides the voltage distribution into a plurality of inspection regions AE1 to AE4 and calculates the movement amount d for each of the plurality of inspection regions AE1 to AE4. With this configuration, it is possible to detect the movement of the distribution pattern of the voltage values ​​in any of the plurality of inspection regions AE1 to AE4.

[0065] In the flow velocity calculation process S2, the calculation unit 7 calculates the movement amount d by the brightness difference accumulation method. According to this configuration, the pattern matching using the brightness difference accumulation method can accurately identify similar parts between the voltage distribution at the first time point and the voltage distribution at the second time point, so that the movement amount d can be calculated appropriately.

[0066] The calculation unit 7 also executes a fluid measurement method for calculating the flow direction and flow velocity of the fluid. The fluid measurement method includes the steps of: a) converting the pressure received by the two-dimensionally arranged multiple structures 4 into a two-dimensional voltage distribution using the piezoelectric sensor 3; b) calculating the flow direction using the voltage values ​​of regions in the voltage distribution that correspond to the positions of each structure; and c) calculating a shift d of the distribution pattern of the voltage values ​​between a first voltage distribution obtained at a first time t1 and a second voltage distribution obtained at a second time t2 that is later than the first time t1, and calculating the flow velocity from the calculated shift d. This configuration allows the flow direction and flow velocity to be calculated in a short time.

[0067] <2. Modifications> Although the embodiments have been described above, the present invention is not limited to the above and various modifications are possible.

[0068] For example, in the above embodiment, the inspection areas AE1 to AE4 are all the same size, but this is not essential. Also, the inspection areas AE1 to AE4 may have overlapping portions.

[0069] Furthermore, in the above embodiment, all of the inspection areas AE1 to AE4 are processed, but only some of the inspection areas AE1 to AE4 may be processed. Specifically, some of the inspection areas AE selected from the inspection areas AE1 to AE4 may be processed depending on the wind direction. For example, as shown in FIG. 8, when an airflow occurs in the +X direction, the gas first collides with the structures 4 on the -X side, which is the upwind side, among all the structures 4. Therefore, as shown in the first frame image F1, a potential change is first detected in the -X side area. Therefore, of the inspection areas AE1 to AE4, only the inspection areas AE1 and AE3 on the -X side, which is the upwind side, may be processed.

[0070] Although the present invention has been described in detail, the above description is merely illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually inconsistent. [Explanation of symbols]

[0071] 1: Fluid measuring device 3: Detector 4: Structure 5: Piezoelectric sensor 7: Arithmetic section 10: Substrate processing equipment 53: Piezoelectric layer 55: CMOS sensor array 101: Board holding part 103: Cup AE1~AE4: Inspection area DD: Sensor data (voltage distribution) F1: First frame image (first voltage distribution) F2: Second frame image (second voltage distribution)

Claims

1. A fluid measurement device that measures a flow direction and a flow velocity of a fluid, a piezoelectric sensor having a plurality of two-dimensionally arranged structures formed on the upper portion thereof, the piezoelectric sensor converting pressure received by the plurality of structures into a voltage value; a calculation unit that processes a two-dimensional voltage distribution output from the piezoelectric sensor; Equipped with The calculation unit a flow direction calculation process for calculating a flow direction using a voltage value of an area corresponding to a position of each of the structures in the voltage distribution; a flow velocity calculation process for calculating a shift amount of a distribution pattern of voltage values ​​between a first voltage distribution obtained at a first time and a second voltage distribution obtained at a second time after the first time, and calculating a flow velocity from the calculated shift amount; A fluid measurement device capable of performing the above.

2. The fluid measurement device according to claim 1, The calculation unit calculates the movement amount in the flow velocity calculation process by using the flow direction calculated in the flow direction calculation process as a movement direction of the distribution pattern.

3. The fluid measurement device according to claim 2, The calculation unit uses, in the flow velocity calculation process, a voltage distribution used for calculating the flow direction in the flow direction calculation process as the first voltage distribution.

4. 3. The fluid measurement device according to claim 1, The calculation unit divides the voltage distribution into a plurality of test areas and calculates the movement amount for each of the plurality of test areas in the flow velocity calculation process.

5. 3. The fluid measurement device according to claim 1, The calculation unit calculates the amount of movement by a brightness difference accumulation method in the flow velocity calculation process.

6. A fluid measurement method for measuring a flow direction and a flow velocity of a fluid, comprising: a) converting pressure received by a plurality of two-dimensionally arranged structures into a two-dimensional voltage distribution by a piezoelectric sensor; b) calculating a flow direction using a voltage value of a region corresponding to the position of each of the structures in the voltage distribution; c) calculating a shift amount of a distribution pattern of voltage values ​​between a first voltage distribution obtained at a first time and a second voltage distribution obtained at a second time after the first time, and calculating a flow velocity from the calculated shift amount; A fluid measurement method comprising:

7. A substrate processing apparatus, a substrate holder for holding a substrate; a cup surrounding the substrate holder; a fluid measuring device according to claim 1 or 2, which measures a flow direction and a flow velocity of a fluid around the cup; A substrate processing apparatus comprising:

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