Surface potential distribution measurement device

Abstract

To provide a device for measuring surface potential distribution which enables surface potential distribution of a measurement target to be quickly measured and enables spatial resolution of the device to be easily changed according to the purpose.SOLUTION: A device for measuring surface potential distribution comprises: a sensor substrate 10 having a plurality of sensors 12; a holding portion 20 holding the sensor substrate 10 in an attachable / detachable manner; a vibration portion 40 vibrating the sensor substrate 10 and the holding portion 20; and an electrical property measurement portion 50 measuring potential using each of the sensors 12. The sensor substrate 10 comprises: a substrate 11; the plurality of sensors 12 provided on a first surface which is one of the surfaces of the substrate 11; and a plurality of electrically conductive portions 14 extending from respective sensors 12 in a thickness direction of the substrate 11 and exposed to a second surface opposite the first surface, wherein the electrically conductive portions 14 are insulated from each other, and the sensor substrate has a connection portion 15 provided on the second surface and connecting the electrical property measurement portion and each of electrically conductive portions to each other in an electrically attachable / detachable manner.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a surface potential distribution measuring device.

Background Art

[0002] Filters made of non-woven fabrics composed of polypropylene fibers or the like are used in masks, air purifiers, etc. In order to increase the collection efficiency, the fibers in the non-woven fabric are charged.

[0003] The charging of the non-woven fabric is performed, for example, by corona discharge, water flow charging, etc. The charged state of the non-woven fabric affects the collection efficiency. Therefore, a method for evaluating the charged state is required for product development and product inspection.

[0004] As a method for evaluating the charged state, Patent Document 1 discloses a data acquisition unit that acquires correlation data indicating the correlation between activation energy and temperature using measurement data obtained by measuring the thermally stimulated current of a sample, an extraction unit 43 that extracts a flat portion of a plot when the correlation between activation energy and temperature is graphed using the correlation data, an evaluation unit 44 that evaluates the characteristics of the sample based on the extraction result of the extraction unit 43, and a display unit 6 that displays the evaluation result by the evaluation unit 44 on a screen.

[0005] Patent Document 2 discloses a surface potential sensor including a flexible thin-film electret sensor and an electrostatic force detection means for detecting a change in the electrostatic force acting on the electret sensor.

[0006] Patent Document 3 discloses an electrostatic charge measurement method comprising: an imparting step of applying vibrations of a predetermined frequency and amplitude to an object to be measured; an intensity measurement step of measuring the intensity of electromagnetic waves generated in conjunction with the vibrations of the object to be measured; an amplitude measurement step of measuring the amplitude of the object to be measured; and an electrostatic charge measurement step of measuring the electrostatic charge of the object to be measured based on the intensity of the electromagnetic waves measured in the intensity measurement step and the amplitude measured in the amplitude measurement step, wherein the frequency of the vibrations is several Hz to several kHz, and the object to be measured and the receiving means that realizes the intensity measurement step and receives the electromagnetic waves are spatially separated.

[0007] Patent Document 4 discloses an electrostatic distribution measuring device for measuring the electrostatic distribution on a measurement surface of an object to be measured, comprising: an array antenna that receives electric fields generated in each of a plurality of regions on the measurement surface by vibration; a vibration means that vibrates the object to be measured or the array antenna; a measurement means that measures at least one of the intensity, frequency, and phase of the electric field in each of the plurality of regions received by the array antenna; a calculation means that calculates the amount of electrostatics in each of the plurality of regions based on the measurement results of the measurement means; and a drawing means that draws the electrostatic distribution on the measurement surface based on the amount of electrostatics in each of the plurality of regions, wherein the array antenna has a plurality of antenna elements corresponding to each of the plurality of regions. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2015-28462 [Patent Document 2] Japanese Patent Publication No. 2007-212209 [Patent Document 3] Patent No. 5665151 [Patent Document 4] International Publication No. 2015 / 011942 [Overview of the project] [Problems that the invention aims to solve]

[0009] In filter development, it is required to be able to evaluate the distribution of surface potential with high spatial resolution. On the other hand, in filter quality control, it is required to lower the spatial resolution in order to speed up measurement time. The method in Patent Document 1 can measure the charge state by measuring the discharged current when heat is applied, but it is not possible to evaluate the distribution of surface potential. In the method in Patent Document 2, it was not possible to easily change the spatial resolution with a single device. In the electrostatic charge measurement method in Patent Document 3 and the electrostatic quantity measurement device in Patent Document 4, the amount of electrostatic charge can be measured with high accuracy, but in order to measure the amount of electrostatic charge with a high spatial resolution of about 1 mm, it is necessary to vibrate the object to be measured locally, so the entire range to be measured must be vibrated locally. As a result, there was a problem that it took a long time to measure the distribution of the amount of electrostatic charge. Furthermore, in the electrostatic charge measurement method in Patent Document 3 and the electrostatic quantity measurement device in Patent Document 4, it was not possible to easily change the spatial resolution.

[0010] This invention was made in view of the above circumstances, and aims to provide a surface potential distribution measuring device that can quickly measure the distribution of the surface potential of a target object and can easily change the spatial resolution according to the purpose. [Means for solving the problem]

[0011] To solve the aforementioned problems, the present invention proposes the following means. (1) The surface potential distribution measuring device according to embodiment 1 of the present invention is A sensor board equipped with multiple sensors, A holding portion that detachably holds the sensor substrate, A vibrating unit that vibrates the sensor substrate and the holding unit, An electrical characteristic measurement unit that measures electric potential using the aforementioned sensors, Equipped with, Q Sensor board is circuit board and The plurality of sensors are provided on the first surface, which is one of the surfaces of the substrate, Multiple conductive portions are exposed on the second surface, which is the surface opposite to the first surface, and extend from each of the sensors in the thickness direction of the substrate, Equipped with, Each of the aforementioned conductive parts is insulated from each other. The sensor substrate is provided on the second surface with connection parts that electrically and detachably connect the electrical characteristic measurement unit and each of the conductive parts. (2) Aspect 2 of the present invention is a surface potential distribution measuring device of aspect 1, The spatial resolution may be changed by replacing the aforementioned sensor board. (3) Embodiment 3 of the present invention is a surface potential distribution measuring device of Embodiment 1 or Embodiment 2, which further comprises a vibration measuring unit for measuring the amplitude of the sensor substrate. (4) Embodiment 4 of the present invention is a surface potential distribution measuring device according to any one of Embodiments 1 to 3, The sensors may be arranged in a straight line when viewed from above. (5) Embodiment 5 of the present invention is a surface potential distribution measuring device according to any one of Embodiments 1 to 4, A sample stand on which the object to be measured can be placed, A sample moving unit that moves the sample stage in a direction parallel to the first surface, It may also be provided. (6) Embodiment 6 of the present invention is a surface potential distribution measuring device according to any one of Embodiments 1 to 5, The system may further include a distance measuring unit for measuring the distance between the surface of the object to be measured and the surface of the sensor. [Effects of the Invention]

[0012] According to the above-described aspect of the present invention, a surface potential distribution measuring device can be provided that can quickly measure the distribution of the surface potential of a target object and can easily change the spatial resolution according to the purpose. [Brief explanation of the drawing]

[0013] [Figure 1]It is a schematic diagram of a surface potential distribution measuring device according to the first embodiment. [Figure 2] It is a plan view of the sensor side surface of the sensor substrate. [Figure 3] It is a cross-sectional view along the line F2 - F2 of the sensor substrate shown in FIG. 2. [Figure 4] It is a flowchart of a method for measuring a surface potential distribution according to the first embodiment. [Figure 5] It is a schematic diagram of a surface potential distribution measuring device according to the second embodiment. [Figure 6] It is a flowchart of a method for measuring a surface potential distribution according to the first embodiment. [Figure 7] It is a plan view of the sensor side surface of a modified example of the sensor substrate. [Figure 8] It is a plan view of the sensor side surface of a modified example of the sensor substrate.

MODE FOR CARRYING OUT THE INVENTION

[0014] <First Embodiment> The surface potential distribution measuring device according to the present embodiment includes a sensor substrate provided with a plurality of sensors, a holding unit that detachably holds the sensor substrate, a vibrating unit that vibrates the sensor substrate and the holding unit, and an electrical characteristic measuring unit that measures a potential using each sensor. On a first surface, which is one surface of the sensor substrate, the sensors are provided. On a second surface, which is the opposite surface of the first surface, a plurality of conductive portions extending in the plate thickness direction of the sensor substrate from each of the sensors are exposed, and the respective conductive portions are insulated from each other. The sensor substrate includes a connection unit on the second surface that electrically and detachably connects the electrical characteristic measuring unit and each of the conductive portions. The surface potential distribution measuring device according to the present embodiment can change the spatial resolution by replacing the sensor substrate.

[0015] Hereinafter, with reference to the drawings, a surface potential distribution measuring device 100 according to one embodiment of the present invention will be described. Figure 1 is a schematic diagram of the surface potential distribution measuring device 100. The surface potential distribution measuring device 100 comprises a sensor substrate 10, a holding unit 20, a shaft 30, a vibration unit 40, a vibration control unit 45, an electrical characteristic measurement unit 50, a sample stage 60, a sample moving unit 65, and a control unit 80.

[0016] The amount of charge (surface potential) Q of the portion of the object to be measured O (measurement region) in the sensor substrate 10 facing the sensor is calculated, for example, based on the following equation (1). Here, in equation (1), ΔV means the difference (potential difference) between the maximum potential and the minimum potential detected by the sensor on the sensor substrate 10, ε means the dielectric constant between the sensor on the sensor substrate 10 and the portion of the object to be measured O facing the sensor, S means the area of ​​the sensor, D means the distance between the surface of the sensor and the surface of the object to be measured O along the thickness direction of the sensor substrate 10, and R means the amplitude of vibration of the sensor substrate 10.

[0017]

number

[0018] By moving the object to be measured O in a predetermined direction and calculating the surface potential of each portion of the object to be measured O facing each sensor on the sensor substrate 10 using equation (1) above, the surface potential distribution of the surface of the object to be measured O can finally be calculated. For example, the methods described in Patent Documents 3 and 4 can be used for calculating the surface potential.

[0019] The following describes each part. In the following description, the X direction is the direction parallel to the first surface 11a of the sensor substrate 10. The Y direction is the direction parallel to the first surface 11a of the sensor substrate 10 and intersects with the X direction. For example, the Y direction is approximately perpendicular to the X direction. The Z direction is the thickness direction of the substrate 11 of the sensor substrate 10 and intersects with the X and Y directions. For example, the Z direction is approximately perpendicular to the X and Y directions. The "downward direction in the Z direction" refers to the direction from the sensor substrate 10 toward the sample stage 60 along the Z direction. The "upward direction in the Z direction" refers to the direction opposite to the direction from the sensor substrate 10 toward the sample stage 60 along the Z direction. However, the terms "up" and "down" used herein are for explanatory convenience and do not define the direction of gravity.

[0020] (Sensor board 10) Figure 2 is a plan view of the sensor-side surface (first surface) of the sensor substrate 10. Figure 3 is a cross-sectional view of the sensor substrate 10 shown in Figure 2 along the line F2-F2. The sensor substrate 10 comprises a substrate 11, a plurality of sensors 12 provided on the first surface 11a, which is one surface of the substrate 11, and a plurality of conductive parts 14 exposed on the second surface 11b, which is the opposite surface of the first surface 11a, and extending from each sensor 12 in the thickness direction of the substrate 11. In the first embodiment, the thickness direction of the substrate 11 is the same as the Z direction.

[0021] The substrate 11 is not particularly limited as long as it can insulate the conductive parts 14 from each other. As the material of the substrate 11, resins commonly used for printed circuit boards can be used. For example, a combination of paper or glass cloth as the base material and epoxy resin, phenolic resin, or polyimide resin as the resin may be used. The substrate 11 is provided with a plurality of through holes 18 for passing the fixing part 22 through. It is preferable that there be two or more through holes. If there are two or more through holes, the change in potential can be precisely measured even if the sensor substrate 10 is vibrated during measurement.

[0022] Sensor 12 is provided on the first surface 11a, which is one of the surfaces of the substrate 11. Sensor 12 is a sensor that detects changes in potential caused by changing the distance from the surface of the object to be measured O. Using sensor 12, for example, the difference between the maximum potential and the minimum potential (potential difference) can be measured. Alternatively, sensor 12 may be used to measure the periodic change in potential (potential frequency) caused by the periodic change in the distance between the charged part of the object to be measured O and sensor 12. Furthermore, sensor 12 may be used to detect the phase difference (potential phase difference) between the period of change in the relative distance between the charged part of the object to be measured O and sensor 12 and the period of potential detected by sensor 12.

[0023] Sensor 12 is not particularly limited as long as it can detect changes in electrical potential. Sensor 12 is, for example, a thin film of metal such as gold or copper. The shape of sensor 12 is not particularly limited, but for example, it is square in plan view. Sensors 12 are arranged at predetermined intervals. The length lx of sensor 12 in the X direction is not particularly limited. For example, the length lx of sensor 12 in the X direction is 0.1 mm to 5 mm. Similarly, the length ly of sensor 12 in the Y direction is not particularly limited. For example, the length ly of sensor 12 in the Y direction is 0.1 mm to 5 mm. The length lx of sensor 12 in the x direction, the length ly of sensor 12, and the spacing between sensors 12 can be appropriately set according to the desired resolution. By appropriately setting the distance between sensor 12 and the measurement target O (1 / 4 to 3 / 4 of the spatial resolution) and the vibration amplitude (1 / 8 to 3 / 8 of the spatial resolution), the size of sensor 12 and the spatial resolution can be made approximately the same.

[0024] Multiple sensors 12 are arranged in a straight line on the substrate 11 in a plan view. Here, the sensors 12 are arranged along a virtual line L1 parallel to the X direction. In the first embodiment, it is preferable that the length ls of the arrangement of sensors 12 is longer than the length of the object to be measured O in the direction perpendicular to the direction in which the object to be measured O is moved (here, the Y direction) when measuring the potential. By arranging them in this way, the object to be measured O can be moved in only one direction (the Y direction) without moving the object to be measured O in the X direction. If the length ls of the arrangement of sensors 12 is shorter than the length of the object to be measured O in the direction perpendicular to the direction in which the object to be measured O is moved, the surface potential distribution can be measured over the entire surface area of ​​the side of the object to be measured O facing the sensors 12 by moving the object to be measured O in the X direction as well.

[0025] The sensor substrate 10 has a second surface 11b that is exposed to the surface opposite the first surface 11a, and comprises a plurality of conductive parts 14 that extend from each sensor 12 in the thickness direction of the substrate 11. The conductive parts 14 are insulated from each other by the substrate 11, which is an insulator. In the first embodiment, the conductive parts 14 penetrate the substrate 11. In the first embodiment, the sensor 12 and the conductive parts 14 are electrically connected. The conductive parts 14 are not particularly limited as long as they are made of a material that can transmit the potential obtained by the sensor 12 to the electrical characteristic measurement unit 50. The conductive parts 14 are, for example, a metal such as Cu. The conductive parts 14 are electrically connected to the wiring 16.

[0026] The sensor board 10 has connection parts 15 on its second surface 11b that electrically and detachably connect the electrical characteristic measurement unit 50 and each conductive part 14. The connection parts 15 are electrically connected to the wiring 16. The connection parts 15 are, for example, connector terminals. By providing detachable connection parts 15, the sensor board 10 can be changed to one suitable for the purpose.

[0027] (Holding part 20) The holding portion 20 detachably holds the sensor substrate 10. The holding portion 20 comprises a holding plate 21 and a fixing portion 22. The holding plate 21 is a plate for fixing the sensor substrate 10. The sensor substrate 10 is positioned so that the second surface 11b and the surface 21a of the holding plate 21 face each other, and the sensor substrate 10 and the holding plate 21 are fixed by the fixing portion 22. In Figure 1, the holding plate 21 and the sensor substrate 10 are separated, but they may be in contact. There may be a spacer between the holding plate 21 and the sensor substrate 10. The fixing portion 22 is not particularly limited as long as it can transmit vibrations to the sensor substrate 10 and the holding plate 21 and the fixing portion 22 can be detachably fixed. For example, the fixing portion 22 is a bolt and nut. The fixing portion 22 can be detachably fixed by passing it through the through hole 18 of the substrate 11 and fixing it.

[0028] (Shaft 30) The shaft 30 connects the holding plate 21 of the holding part 20 to the vibrating part 40. The shaft 30 is not particularly limited as long as it is capable of holding the sensor substrate 10 and the holding part 20.

[0029] (Vibrating part 40) The vibrating unit 40 vibrates the holding unit 20 and the sensor substrate 10 in a predetermined direction (for example, in the thickness direction of the sensor substrate 10). In the first embodiment, the vibrating unit 40 vibrates the holding plate 21 and the sensor substrate 10 in the thickness direction of the sensor substrate 10 by vibrating the shaft 30. The vibrating unit 40 is not particularly limited as long as it can vibrate the sensor substrate 10 and the holding unit 20 at a predetermined period. The vibrating unit 40 is electrically connected to, for example, the vibration control unit 45. The vibrating unit 40 is controlled by the vibration control unit 45. In the first embodiment, the vibrating unit 40 is provided with an acceleration sensor (not shown). The acceleration sensor (not shown) measures the vibration information (amplitude) of the vibrating unit 40 and sends it to the control unit 80.

[0030] (Vibration control unit 45) The vibration control unit 45 controls the vibration unit 40 so that the sensor substrate 10 vibrates under predetermined conditions. The period (frequency) at which the vibration unit 40 vibrates the sensor substrate 10 and the holding unit 20 is not particularly limited. For example, the period of the vibration unit 40 is 10 Hz to 5 kHz. A more preferred period is in the range of 100 Hz to 1 kHz. The amplitude at which the vibration unit 40 vibrates the sensor substrate 10 and the holding unit 20 is not particularly limited. For example, the amplitude of the vibration unit 40 is 0.01 mm to 1 mm. A more preferred amplitude of the vibration unit 40 is 0.05 mm to 0.5 mm. The vibration control unit 45 vibrates the sensor substrate 10 and the holding unit 20 based on a signal sent from the control unit 80, for example.

[0031] Here, we will explain the amplitude of vibration of the sensor substrate 10. In equation (1) above, if the charge Q, dielectric constant ε, sensor area S of the sensor substrate 10, and distance D are constant, the detected potential difference ΔV can be calculated by the following equation (2). In equation (2), a and b are predetermined constants.

[0032]

number

[0033] As shown in equation (2) above, the potential difference ΔV detected by the sensor 12 is expressed as a function only of the amplitude R of the sensor substrate 10. That is, as the amplitude R increases, the potential difference ΔV also increases. The surface potential distribution measuring device 100 can detect the surface potential of the object to be measured O with high accuracy by adjusting (increasing) the amplitude R.

[0034] (Electrical characteristics measurement unit 50) The electrical characteristics measurement unit 50 measures the potential using each sensor 12. The electrical characteristics measurement unit 50 is, for example, a lock-in amplifier (not shown). Preferably, the electrical characteristics measurement unit 50 removes noise and other unwanted signals from the signals detected by the sensors 12 and can simultaneously measure minute signals on multiple channels. The time constant of the lock-in amplifier is not particularly limited, but is preferably in the range of 0.1 ms to 1 s. A more preferable time constant for the lock-in amplifier is 1 ms to 300 ms. The electrical characteristics measurement unit 50 is electrically connected to the control unit 80 and sends the potential obtained from each sensor 12 to the control unit 80.

[0035] (Sample stage 60) The sample stage 60 is a stage on which the object to be measured O can be placed. The sample stage 60 is not particularly limited as long as the object to be measured can be placed on it. The sample stage 60 has a function to adjust the distance D between the surface of the object to be measured O and the surface of the sensor 12.

[0036] (Sample transfer unit 65) The sample moving unit 65 moves the sample stage 60 in a direction parallel to the first surface 11a. In a plan view, if multiple sensors 12 are arranged in a straight line on the virtual line L1, it is preferable for the sample moving unit 65 to move the sample stage 60 in a direction perpendicular to the virtual line L1. By moving it in this way, the surface potential distribution of the object to be measured O can be measured efficiently. The sample moving unit 65 can be moved in the X and Y directions by, for example, a motor. The sample moving unit 65 is controlled by the control unit 80.

[0037] (Control unit 80) The control unit 80 moves the object to be measured O while vibrating the sensor substrate 10 and the holding unit 20 by controlling the vibration control unit 45 and the sample moving unit 65. At the same time, the control unit 80 uses the electrical characteristic measurement unit 50 to measure the time change (potential information) of the potential of each sensor 12. The control unit 80 also obtains vibration information of the sensor substrate 10 using an acceleration sensor (not shown) provided on the vibration unit 40. The control unit 80 calculates the surface potential distribution of the object to be measured O from the potential information, the vibration information of the sensor substrate 10, and the information on the amount of movement of the object to be measured O. The obtained surface potential distribution of the object to be measured O is output to a storage unit (not shown) or a display unit (not shown).

[0038] The control unit 80 may consist of, for example, a Central Processing Unit (CPU), Read Only Memory (ROM), Random Access Memory (RAM), and a Hard Disk Drive (HDD) / Solid State Drive (SSD), which are not shown. In this case, the storage unit (not shown) will be an HDD or SSD. The display unit will be, for example, a liquid crystal display. The operation of the control unit 80 may be realized, for example, by executing a predetermined program in the CPU. The control unit 80 may also use a dedicated hardware configuration.

[0039] (Measurement target O) The object to be measured, O, is not particularly limited. Examples of the shape of the object to be measured, O, include rectangular, cylindrical, or film-like shapes.

[0040] As described above, the surface potential distribution measuring device 100 according to this embodiment has been described in detail. Since the surface potential distribution measuring device 100 according to this embodiment is equipped with multiple sensors 12, the distribution of surface potential within the surface of the object to be measured can be quickly measured in a single measurement. Furthermore, since the sensor substrate 10 is detachably held in the holding part 20, and the sensor substrate 10 is equipped with a connection part 15 that detachably connects the electrical characteristic measurement part 50 and each conductive part 14, the sensor substrate 10 can be easily replaced according to the purpose. Therefore, the resolution can be changed according to the application.

[0041] In the first embodiment, the holding portion 20 included a holding plate 21 and a fixing portion 22, but the configuration of the holding portion 20 is not limited to this configuration as long as the sensor substrate 10 can be detachably held.

[0042] In the first embodiment, the sample stage 60 was equipped with a function to adjust the distance D between the surface of the object to be measured O and the surface of the sensor 12, but a distance adjustment unit (not shown) may be provided to adjust the distance D between the surface of the object to be measured O and the surface of the sensor 12.

[0043] In the first embodiment, the substrate 11 was provided with through holes 18, but if the sensor substrate 10 can be detachably held by the holding part 20, the substrate 11 does not need to have through holes 18.

[0044] <Method for measuring surface potential distribution> Next, we will explain how to measure the potential distribution of the object O using the surface potential distribution measuring device 100. Figure 4 is a flowchart of the surface potential distribution measurement method.

[0045] First, the distance D between the surface of the object to be measured O and the surface of the sensor 12 is set to within the allowable range of the reference distance DS, which is the measurable distance (S1). Specifically, if the distance D is within a predetermined value (allowable value) α (DS±α) relative to the reference distance DS, the change in potential of the part of the object to be measured O facing the sensor 12 can be detected with high accuracy. The allowable value α is, for example, 0.005 mm to 0.1 mm relative to the reference distance DS. In the first embodiment, the distance D between the surface of the object to be measured O and the surface of the sensor 12 is adjusted using the sample stage 60.

[0046] Next, the vibration unit 40 is driven (ON) (S2). The amplitude R of the vibration is measured by the acceleration sensor in the vibration unit 40, and the obtained amplitude R is transmitted to the control unit 80 (S3). Subsequently, the sample moving unit 65 moves the object to be measured O by a predetermined amount in the Y direction, and the distance moved (travel distance) is transmitted to the control unit 80 (S4). Here, the travel distance per movement of the object to be measured O can be freely determined according to the size of the sensor 12 and the required resolution of the surface potential distribution. Preferably, the travel distance is the same length as the length of the sensor 12 along the same direction as the movement direction Y of the object to be measured O (approximately 0.1 mm to 5 mm). By using such a travel distance, the surface potential distribution of the object to be measured O can be measured more accurately and quickly.

[0047] The change in potential of the portion of the object O facing the sensor 12 is measured for a predetermined time. Information on the change in potential of each sensor 12 is acquired by the electrical characteristics measurement unit 50. The acquired information on the change in potential of each sensor 12 is sent to the control unit 80 (S5). If the measurement of the change in potential has not been completed for the entire surface area of ​​the object O facing the sensor 12 (S6NO), the object O is moved again by a predetermined amount in the Y direction (S4).

[0048] If the measurement of the potential change has been completed for the entire surface area of ​​the surface of the object O facing the sensor 12 (S6YES), the control unit 80 calculates the surface potential distribution of the object O from the potential change information transmitted from the electrical characteristic measurement unit 50, the distance the object O moves per cycle, the number of times the object O moves, the amplitude R, and the reference distance (S7). The calculated surface potential distribution of the object O is then stored in the memory unit or displayed on a display unit (not shown).

[0049] Specifically, a database consisting of numerous data points related to potential changes, reference distances, amplitudes, and corresponding surface potentials is pre-calibrated and created. The surface potential is then calculated from the potential change, reference distance, and amplitude R obtained from each sensor 12. This surface potential is the surface potential of the portion of the object to be measured O facing the sensor 12 when a potential change is detected.

[0050] Therefore, by pre-measuring the relative position of each sensor 12 with respect to the object O, the surface potential distribution of the object O can be measured quickly and with high accuracy using information on potential changes obtained from each sensor 12 (e.g., amount of potential change, potential frequency, phase shift), the distance the object O moves per cycle, the number of times the object O moves, amplitude R, and reference distance.

[0051] As described above, the surface potential distribution measurement method according to this embodiment has been detailed. Since the surface potential distribution measurement method according to this embodiment uses multiple sensors, the distribution of surface potential within the surface of the object to be measured can be quickly measured in a single measurement. Furthermore, since the sensor substrate 10 is detachably held in the holding part 20, and the sensor substrate 10 is equipped with a connection part 15 that detachably connects the electrical characteristic measurement part 50 and each conductive part 14, the sensor substrate 10 can be easily replaced according to the purpose. Therefore, the resolution can be changed according to the application.

[0052] Furthermore, in the surface potential distribution measurement method according to this embodiment, changes in potential are detected while repeatedly moving and stopping the object O to be measured. However, the surface potential distribution measurement method according to this embodiment is not limited to this. For example, the object O to be measured may be moved at a constant speed, and changes in potential may be detected at predetermined intervals of movement. By operating in this manner, the surface potential distribution of the object O to be measured can be measured more quickly.

[0053] In this embodiment, the measurement was performed by moving the sample stage 60 in a direction parallel to the first surface 11a using the sample moving unit 65. However, the measurement may also be performed by moving the vibrating unit 40 in a direction parallel to the first surface 11a using a vibrating unit moving unit (not shown).

[0054] In this embodiment, after setting the distance D between the measurement mode O and the surface of the sensor 12 (S1), the vibration start S2 of the vibration unit 40 and the vibration measurement S3 of the vibration unit 40 were performed. However, the setting of the distance D between the measurement mode O and the surface of the sensor 12 (S1) may be performed after the vibration start S2 of the vibration unit 40 and the vibration measurement S3 of the vibration unit 40.

[0055] In this embodiment, the measurement of the potential change S5 was performed after moving the object to be measured O by a predetermined amount (S4), but the measurement mode O may be moved by a predetermined amount after performing the measurement of the potential change S5 (S4).

[0056] In this case, the movement speed of the object to be measured O is not particularly limited, but is, for example, in the range of 0.1 mm / s to 200 mm / s. A movement speed of 1 to 20 mm / s is more preferable. The movement distance of the object to be measured O is also not particularly limited, but is, for example, in the range of 0.01 mm to 5 mm. A movement distance of 0.1 mm to 1 mm is more preferable.

[0057] (Second Embodiment) Next, a surface potential distribution measuring device 100B according to a second embodiment of the present invention will be described with reference to Figure 5. In this second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions are omitted; only the differences will be described. The surface potential distribution measuring device 100B includes a sensor substrate 10, a holding part 20, a shaft 30, a vibration part 40, a vibration control unit 45, an electrical characteristic measurement unit 50, a sample stage 60, a sample moving part 65B, a control unit 80B, a vibration measurement unit 110, and a distance measurement unit 120. The spatial resolution of the surface potential distribution measuring device 100B according to the second embodiment can be changed by replacing the sensor substrate 10. Each part will be described below.

[0058] (Vibration measurement unit 110) The vibration measurement unit 110 measures the amplitude of the sensor substrate 10. The vibration measurement unit 110 is electrically connected to the control unit 80B. The vibration measurement unit 110 is not particularly limited as long as it can measure the amplitude of the sensor substrate 10. For example, the vibration measurement unit 110 is a laser displacement sensor. The vibration measurement unit 110 sends the measured vibration information of the sensor substrate 10 to the control unit 80B.

[0059] (Distance measuring unit 120) The distance measuring unit 120 measures the distance D between the surface of the sensor 12 and the surface of the object to be measured O. By measuring the positional relationship between the position of the distance measuring unit 120 and the surface of the sensor 12 in advance, the distance D between the surface of the sensor 12 and the surface of the object to be measured O can be measured. The distance measuring unit 120 is not particularly limited as long as it can measure the distance D between the surface of the sensor 12 and the surface of the object to be measured O. For example, the distance measuring unit 120 is a laser displacement sensor. The distance measuring unit 120 sends the measured distance D between the surface of the sensor 12 and the surface of the object to be measured O to the control unit 80B.

[0060] (Sample transfer unit 65B) The sample moving unit 65B moves the sample stage 60 in a direction parallel to the first surface 11a. The sample moving unit 65B also adjusts the distance D between the surface of the object to be measured O and the surface of the sensor 12. If multiple sensors 12 are arranged in a straight line in a plan view on the virtual line L1, it is preferable for the sample moving unit 65B to move the sample stage 60 in a direction perpendicular to the virtual line L1. Moving it in this way allows for efficient measurement of the surface potential distribution of the object to be measured O. The sample moving unit 65B can be moved in the X, Y, and Z directions, for example, by a motor. The sample moving unit 65B is controlled by the control unit 80B.

[0061] (Control Unit 80B) The control unit 80B moves the object to be measured O while vibrating the sensor substrate 10 and the holding unit 20 by controlling the vibration control unit 45 and the sample moving unit 65B. At the same time, the control unit 80B uses the electrical characteristic measurement unit 50 to measure the time change (potential information) of the potential of each sensor 12. In addition, the control unit 80B uses the sample moving unit 65B to adjust the position of the object to be measured O in the Z direction based on the distance D between the surface of the object to be measured O and the surface of the sensor 12 obtained by the distance measurement unit 120. Specifically, the position of the object to be measured O is adjusted so that the distance D is within the allowable range of the reference distance DS (DS ± α).

[0062] The control unit 80B obtains vibration information of the sensor substrate 10 using the vibration measurement unit 110. The control unit 80B calculates the surface potential distribution of the object O from the potential information, the vibration information of the sensor substrate 10, and the displacement information of the object O. The obtained surface potential distribution of the object O is output to a storage unit (not shown) or a display unit (not shown). The surface potential distribution is, for example, a surface potential quantity distribution.

[0063] As described above, the surface potential distribution measuring device according to this embodiment has been described in detail. Since the surface potential distribution measuring device 100B according to this embodiment is equipped with multiple sensors 12, the distribution of surface potential in the surface of the object to be measured can be quickly measured in a single measurement. Furthermore, since the sensor substrate 10 is detachably held in the holding part 20, and the sensor substrate 10 is equipped with a connecting part 15 that detachably connects the electrical characteristic measurement part 50 and each conductive part 14, the sensor substrate 10 can be easily replaced according to the purpose. Therefore, the resolution can be changed according to the application.

[0064] Furthermore, since the amplitude of the sensor substrate 10 is directly measured using the vibration measurement unit 110, the surface potential distribution of the measurement target O can be calculated with greater accuracy. In addition, since the distance D between the surface of the measurement target O and the surface of the sensor 12 is adjusted using the distance measurement unit 120, the surface potential distribution of the measurement target O can be calculated with greater accuracy.

[0065] <Method for measuring surface potential distribution> Next, we will explain how to measure the potential distribution of the object O using the surface potential distribution measuring device 100B. Figure 6 is a flowchart of the surface potential distribution measurement method.

[0066] First, the distance D between the surface of the object to be measured O and the surface of the sensor 12 is set to within the allowable range of the reference distance DS, which is the measurable distance (S1). Specifically, if the distance D is within a predetermined value (allowable value) α (DS±α) relative to the reference distance DS, the change in potential of the part of the object to be measured O facing the sensor 12 can be detected with high accuracy. The allowable value relative to the reference distance DS is, for example, 0.005 mm to 0.1 mm. In the second embodiment, the distance D between the surface of the object to be measured O and the surface of the sensor 12 is adjusted using the sample moving unit 65.

[0067] Next, the vibration unit 40 is driven (ON) (S2). The amplitude R is measured by the vibration measurement unit 110, and the obtained amplitude R is transmitted to the control unit 80 (S3B). Subsequently, the sample moving unit 65B moves the object to be measured O by a predetermined amount in the Y direction, and the distance moved (movement distance) is transmitted to the control unit 80B (S4). Here, the distance moved each time the object to be measured O moves can be freely determined according to the size of the sensor 12 and the required resolution of the surface potential distribution. Preferably, the movement distance is the same length as the length of the sensor 12 along the same direction as the movement direction Y of the object to be measured O (approximately 0.1 mm to 5 mm). By using such a movement distance, the surface potential distribution of the object to be measured O can be measured more accurately and quickly.

[0068] The distance measurement unit 120 is used to measure the distance D between the surface of the object to be measured O and the surface of the sensor 12. If the distance D is not within a predetermined range (DS±α), the sample moving unit 65B is used to adjust the distance D between the surface of the object to be measured O and the surface of the sensor 12 so that the distance D between the surface of the object to be measured O and the surface of the sensor 12 falls within the predetermined range (S8).

[0069] After adjusting the distance D between the surface of the object to be measured O and the surface of the sensor 12, the change in potential of the portion of the object to be measured O facing the sensor 12 is measured for a predetermined time. Information on the change in potential of each sensor 12 is acquired by the electrical characteristics measurement unit 50. The acquired information on the change in potential of each sensor 12 is sent to the control unit 80 (S5). If the measurement of the change in potential has not been completed for the entire surface area of ​​the side of the object to be measured O facing the sensor 12 (S6NO), the object to be measured O is moved again by a predetermined amount in the Y direction (S4).

[0070] If the measurement of the potential change has been completed for the entire surface area of ​​the surface of the object O facing the sensor 12 (S6YES), the control unit 80 calculates the surface potential distribution of the object O from the potential change information transmitted from the electrical characteristic measurement unit 50, the distance the object O moves per cycle, the number of times the object O moves, the amplitude R, and the reference distance (S7). The calculated surface potential distribution of the object O is then stored in the memory unit or displayed on a display unit (not shown).

[0071] Specifically, a database consisting of numerous data points related to potential changes, reference distances, amplitudes, and corresponding surface potentials is pre-calibrated and created. The surface potential is then calculated from the potential change, reference distance, and amplitude R obtained from each sensor 12. This surface potential is the surface potential of the portion of the object to be measured O facing the sensor 12 when a potential change is detected.

[0072] Therefore, by pre-measuring the relative position of each sensor 12 with respect to the object O, the surface potential distribution of the object O can be measured quickly and with high accuracy using information on potential changes obtained from each sensor 12 (e.g., amount of potential change, frequency, phase shift), the distance the object O moves per cycle, the number of times the object O moves, the amplitude R, and the reference distance.

[0073] As described above, the method for measuring surface potential distribution according to the second embodiment has been described in detail. Since the method for measuring surface potential distribution according to this embodiment uses multiple sensors, the distribution of surface potential within the surface of the object to be measured can be quickly measured in a single measurement. Furthermore, since the sensor substrate 10 is detachably held in the holding part 20, and the sensor substrate 10 is equipped with a connection part 15 that detachably connects the electrical characteristic measurement part 50 and each conductive part 14, the sensor substrate 10 can be easily replaced according to the purpose. Therefore, the resolution can be changed according to the application.

[0074] In this embodiment, the measurement was performed by moving the sample stage 60 in a direction parallel to the first surface 11a using the sample moving unit 65B. However, the measurement may also be performed by moving the vibrating unit 40 in a direction parallel to the first surface 11a using a vibrating unit moving unit (not shown).

[0075] In this embodiment, after setting the distance D between the measurement mode O and the surface of the sensor 12 (S1), the vibration start S2 of the vibration unit 40 and the vibration measurement S3B of the vibration unit 40 were performed. However, the vibration start S2 of the vibration unit 40 and the vibration measurement S3B of the vibration unit 40 may be performed first, and then the distance D between the measurement mode O and the surface of the sensor 12 (S1) may be set.

[0076] In this embodiment, after moving the object to be measured O by a predetermined amount (S4), the distance between the object to be measured O and the sensor 12 was adjusted S8 and the potential change was measured S5. However, after adjusting the distance between the object to be measured O and the sensor 12 S8 and measuring the potential change S5, the object to be measured O may be moved by a predetermined amount (S4). If the object to be measured O is flat, the distance adjustment S8 may be omitted.

[0077] Furthermore, since the amplitude of the sensor substrate 10 is directly measured using the vibration measurement unit 110, the surface potential distribution of the measurement target O can be calculated with greater accuracy. In addition, since the distance D between the surface of the measurement target O and the surface of the sensor 12 is adjusted using the distance measurement unit 120, the surface potential distribution of the measurement target O can be calculated with greater accuracy.

[0078] (Variation 1) Figure 7 is a plan view of the sensor-side surface (first surface) of the sensor substrate 10A of Modified Example 1. An absorption section 17 is provided on the substrate 11 so as to surround the sensor 12. The absorption section 17 is not particularly limited as long as it can reduce electromagnetic influences. The absorption section 17 is, for example, a thin film of metal such as gold or copper, or an electromagnetic wave absorbing sheet. By providing the absorption section 17, electromagnetic influences from parts of the surface of the object to be measured O other than the parts facing each sensor 12 can be reduced. Each sensor 12 can mainly detect changes in potential from the parts facing the object to be measured O. Therefore, a more accurate surface potential can be measured. As a result, the surface potential distribution measuring device 100 can measure the potential distribution with higher spatial resolution.

[0079] In the sensor substrate 10A of the modified example 1, the absorption portion 17 was provided so as to surround the sensor 12, but it is not necessarily required to provide the absorption portion 17 so as to completely surround the sensor 12. The absorption portion 17 may be formed only on a part of the periphery of the sensor 12.

[0080] (Modification 2) Figure 8 is a plan view of the sensor-side surface (first surface) of the sensor substrate 10B of the modified example 2. In plan view, the sensors 12 are arranged on virtual lines L1 and L2. Virtual line L1 is approximately parallel to virtual line L2. In the case of sensor substrate 10B, since multiple sensors 12 are arranged in two rows, for example, the distance the measurement target O moves in one step can be doubled compared to the case of a single row. As a result, the potential distribution of the measurement target O can be measured in half the time compared to the case of a single row.

[0081] The surface potential distribution measuring device of the present invention has been described above. It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. Furthermore, without departing from the spirit of the present invention, the components in the above embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of symbols]

[0082] 10 Sensor substrate, 11 Substrate, 12 Sensor, 14 Conductive part, 15 Connection part, 20 Holding part, 21 Holding plate, 22 Fixing part, 30 Shaft, 40 Vibration part, 45 Vibration control unit, 50 Electrical characteristic measurement unit, 60 Sample stage, 65 Sample moving part, 80 Control unit, 100 Surface potential distribution measurement device, 110 Vibration measurement unit, 120 Distance measurement unit

Claims

1. A sensor board equipped with multiple sensors, A holding portion that detachably holds the sensor substrate, A vibrating unit that vibrates the sensor substrate and the holding unit, An electrical characteristic measurement unit that measures electric potential using the aforementioned sensors, Equipped with, Q Sensor board is circuit board and The plurality of sensors are provided on the first surface, which is one of the surfaces of the substrate, Multiple conductive portions are exposed on the second surface, which is the surface opposite to the first surface, and extend from each of the sensors in the thickness direction of the substrate, Equipped with, Each of the aforementioned conductive parts is insulated from each other. The sensor substrate is provided with a connection portion on the second surface for electrically detachably connecting the electrical characteristic measurement unit and each of the conductive parts, respectively. A surface potential distribution measuring device that can change the spatial resolution by replacing the aforementioned sensor substrate.

2. The surface potential distribution measuring device according to claim 1, further comprising a vibration measuring unit for measuring the amplitude of the sensor substrate.

3. The surface potential distribution measuring device according to claim 1, wherein each of the sensors is arranged in a straight line in a plan view.

4. A sample stand on which the object to be measured can be placed, A sample moving unit that moves the sample stage in a direction parallel to the first surface, The surface potential distribution measuring device according to claim 1, further comprising:

5. The surface potential distribution measuring device according to claim 4, further comprising a distance measuring unit for measuring the distance between the surface of the object to be measured and the surface of the sensor.

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