Measuring instrument

Abstract

An exemplary embodiment of the measuring device of the present invention includes a substrate, a sensor chip disposed on the substrate, and a circuit board disposed on the substrate. The sensor chip includes a sensor portion comprising: a signal electrode having a front surface radially intersecting the substrate; a shielding electrode disposed behind the signal electrode; and a first ground electrode disposed behind the shielding electrode. The sensor chip includes a second ground electrode extending along the lower surface of the sensor portion. Only an insulating material is filled between the second ground electrode and the sensor portion.

Description

Measuring device An exemplary embodiment of the present invention relates to a measuring device. Japanese Patent Application Publication No. 2017-3557 discloses a measuring device having a sensor chip for measuring electrostatic capacitance. The sensor chip includes a first electrode, a second electrode, and a third electrode. The first electrode has a first portion. The second electrode has a second portion extending above the first portion and is insulated from the first electrode within the sensor chip. The third electrode has a front surface extending in a direction intersecting the first and second portions, is disposed above both the first and second portions, and is insulated from the first and second electrodes within the sensor chip. In one exemplary embodiment, a measuring device is provided. The measuring device includes: a circular substrate, a sensor chip disposed on the substrate, and a circuit board disposed on the substrate. The sensor chip includes a sensor portion comprising: a signal electrode having a front surface that radially intersects the substrate; a shielding electrode disposed away from the signal electrode and extending along the signal electrode; and a first ground electrode disposed behind the shielding electrode. The circuit board includes: a high-frequency oscillator configured to apply high-frequency signals to the signal electrode and the shielding electrode respectively; and a C / V (capacitance-voltage) conversion circuit that generates a voltage signal corresponding to the electrostatic capacitance formed by the signal electrode. The C / V conversion circuit has an amplification circuit including an operational amplifier. The high-frequency oscillator is connected to a non-inverting input terminal such that the high-frequency signal applied to the signal electrode is input to the non-inverting input terminal of the operational amplifier, and is connected to an inverting input terminal such that the high-frequency signal applied to the signal electrode is input to the inverting input terminal of the operational amplifier. The sensor chip includes a second ground electrode extending along the lower surface of the sensor section. The signal electrode, shielding electrode, and first ground electrode of the sensor section all extend to the lower end of the sensor section. Only insulating material is filled between the second ground electrode and the sensor section. The following describes various exemplary embodiments. In one exemplary embodiment, a measuring device is provided. The measuring device includes: a circular substrate, a sensor chip disposed on the substrate, and a circuit board disposed on the substrate. The sensor chip includes a sensor portion comprising: a signal electrode having a front surface that radially intersects the substrate; a shielding electrode disposed away from the signal electrode and extending along the signal electrode; and a first ground electrode disposed behind the shielding electrode. The circuit board includes: a high-frequency oscillator configured to apply high-frequency signals to the signal electrode and the shielding electrode respectively; and a C / V conversion circuit that generates a voltage signal corresponding to the electrostatic capacitance formed by the signal electrode. The C / V conversion circuit includes an amplification circuit including an operational amplifier. The high-frequency oscillator is connected to a non-inverting input terminal such that the high-frequency signal applied to the signal electrode is input to a non-inverting input terminal of the operational amplifier, and is connected to an inverting input terminal such that the high-frequency signal applied to the signal electrode is input to an inverting input terminal of the operational amplifier. The sensor chip includes a second ground electrode extending along the lower surface of the sensor portion. The signal electrode, shielding electrode, and first ground electrode of the sensor unit all extend to the lower end of the sensor unit. The space between the second ground electrode and the sensor unit is filled only with insulating material. In the measuring device of the above embodiment, the signal electrode is shielded from the rear by a shielding electrode and a first ground electrode, and from the bottom by a second ground electrode. Therefore, according to this sensor chip, electrostatic capacitance can be measured with high directivity in a specific direction, that is, in the direction in which the front surface of the signal electrode faces. Furthermore, ESD (electrostatic discharge) to the shielding electrode is suppressed, thus preventing ESD from damaging the operational amplifier via the shielding electrode. In one exemplary embodiment, the shielding electrode constituting the sensor portion may not include a portion extending along the lower surface of the sensor portion. In one exemplary embodiment, from a top view, the front surface of the signal electrode, the front surface of the shielding electrode, and the front surface of the first ground electrode can all be curved surfaces parallel to the curved surface formed by the outer periphery of the substrate. In one exemplary embodiment, the sensor chip may have a first flexible substrate extending along the lower surface of the sensor portion and including a second ground electrode. In one exemplary embodiment, the sensor chip may have a second flexible substrate extending along the upper surface of the sensor portion. In one exemplary embodiment, the front surface of the signal electrode may be covered with an insulating material having insulating properties. In one exemplary embodiment, the insulating material on the front surface of the covered signal electrode may also be formed of borosilicate glass or quartz. Hereinafter, various embodiments will be described in detail with reference to the drawings. Furthermore, the same or equivalent parts in each drawing will be labeled with the same symbols. An exemplary embodiment of the measuring device can be conveyed by a processing system 1 that functions as a conveying system S1. First, the processing system, which includes a processing apparatus for processing workpieces and a conveying apparatus for conveying workpieces to the processing apparatus, will be described. Figure 1 is a diagram illustrating the processing system. The processing system 1 includes: stands 2a-2d, containers 4a-4d, a carrier module LM, an alignment device AN, load locking modules LL1, LL2, process modules PM1-PM6, a transfer module TF, and a control unit MC. Furthermore, the number of stands 2a-2d, containers 4a-4d, load locking modules LL1, LL2, and process modules PM1-PM6 is not limited and can be any number of more than one. The pedestals 2a to 2d are arranged along one edge of the carrier module LM. Containers 4a to 4d are respectively mounted on the pedestals 2a to 2d. Each of the containers 4a to 4d is, for example, a container referred to as a FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d can be configured to house the workpiece W. The workpiece W, like a wafer, has a generally disk-shaped form. The carrier module LM has chamber walls that divide its interior into transport spaces at atmospheric pressure. A transport device TU1 is installed within this transport space. The transport device TU1 is, for example, a multi-joint robotic arm, controlled by a control unit MC. The transport device TU1 is configured to transport the workpiece W between containers 4a-4d and the alignment device AN, between the alignment device AN and the load locking modules LL1-LL2, and between the load locking modules LL1-LL2 and containers 4a-4d. The aligner AN is connected to the carrier module LM. The aligner AN is configured to adjust the position (position calibration) of the workpiece W. Figure 2 is a perspective view illustrating the aligner. The aligner AN has a support stage 6T, a drive device 6D, and a sensor 6S. The support stage 6T is a platform capable of rotating about a center axis extending in the vertical direction. The support stage 6T is configured to support the workpiece W. The support stage 6T is rotated by the drive device 6D. The drive device 6D is controlled by the control unit MC. When the support stage 6T rotates by power from the drive device 6D, the workpiece W placed on the support stage 6T also rotates. Sensor 6S is an optical sensor. Sensor 6S detects the edge of workpiece W during its rotation. Based on the edge detection results, sensor 6S detects the offset of the angular position of the notch WN (or other marking) of workpiece W relative to a reference angular position, and the offset of the center position of workpiece W relative to the reference position. Sensor 6S outputs the offset of the angular position of notch WN and the offset of the center position of workpiece W to control unit MC. Control unit MC calculates the rotation amount of support stage 6T to correct the angular position of notch WN to the reference angular position based on the offset of the angular position of notch WN. Control unit MC controls drive device 6D to rotate support stage 6T by this rotation amount. This allows the angular position of notch WN to be corrected to the reference angular position. Furthermore, based on the offset of the center position of workpiece W, control unit MC controls the position of the end effector of the conveying device TU1 when the alignment device AN receives workpiece W. In this way, the center position of the workpiece W is consistent with the specified position on the end effector of the conveying device TU1. Returning to Figure 1, load locking modules LL1 and LL2 are each positioned between the carrier module LM and the transmission module TF. Each of the load locking modules LL1 and LL2 provides a pre-pressure reduction chamber. The transfer module TF is airtightly connected to the load locking modules LL1 and LL2 via gate valves. The transfer module TF provides a pressure-reducing chamber. A conveying device TU2 is installed in this pressure-reducing chamber. The conveying device TU2 is, for example, a multi-joint robot with a conveying arm TUa. The conveying device TU2 is controlled by the control unit MC. The conveying device TU2 is configured to convey the workpiece W between the load locking modules LL1-LL2 and the process modules PM1-PM6, and between any two process modules PM1-PM6. Process modules PM1 to PM6 are airtightly connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM6 is configured as a processing device for performing special processing such as plasma treatment on the workpiece W. A series of actions during the processing of workpiece W in the processing system 1 are illustrated as follows: The conveying device TU1 of the carrier module LM removes workpiece W from any of containers 4a to 4d and conveys it to the alignment device AN. Then, the conveying device TU1 removes the adjusted workpiece W from the alignment device AN and conveys it to one of the load-locking modules LL1 and LL2. Next, one load-locking module reduces the pressure in the pre-pressure reduction chamber to a specified pressure. Then, the conveying device TU2 of the transfer module TF removes workpiece W from one of the load-locking modules and conveys it to any of the process modules PM1 to PM6. Finally, one or more of the process modules PM1 to PM6 process workpiece W. Then, the conveying device TU2 transports the processed workpiece W to one of the load-locking modules LL1 and LL2. Subsequently, the conveying device TU1 transports the workpiece W from one of the load-locking modules to any one of the containers 4a to 4d. As described above, the processing system 1 includes a control unit MC. The control unit MC can be a computer equipped with a processor, memory and other memory devices, a display device, input / output devices, communication devices, etc. A series of operations of the processing system 1 are realized by the control unit MC controlling each part of the processing system 1 according to the program stored in the memory device. Figure 3 shows an example of a plasma processing apparatus that can be used as any of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in Figure 3 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 has a generally cylindrical chamber body 12. The chamber body 12 is formed of aluminum, for example, and its inner wall surface can be anodized. The chamber body 12 is safely grounded. A generally cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 may contain, for example, an insulating material. The support portion 14 is disposed within the chamber body 12. The support portion 14 extends upward from the bottom of the chamber body 12. Furthermore, a stage ST is provided within the chamber S provided by the chamber body 12. The stage ST is supported by the support portion 14. The stage ST has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of metal such as aluminum and are generally disk-shaped. The second plate 18b is disposed on the first plate 18a and is electrically connected to the first plate 18a. An electrostatic chuck (ESC) is provided on the second plate 18b. The ESC has a structure in which electrodes, serving as conductive films, are disposed between a pair of insulating layers or sheets, and has a generally disc-shaped structure. The electrodes of the ESC are electrically connected to a DC power supply 22 via a switch 23. The ESC uses electrostatic forces, such as Coulomb force, generated by the DC voltage from the DC power supply 22 to attract the workpiece W. In this way, the ESC can hold the workpiece W. An edge ring ER is provided on the periphery of the second plate 18b. The edge ring ER is configured to surround the edge of the workpiece W and the electrostatic chuck ESC. The edge ring ER has a first portion P1 and a second portion P2 (see Figure 7). Both the first portion P1 and the second portion P2 have annular plate shapes. The second portion P2 is the outermost portion of the first portion P1. The second portion P2 has a greater thickness in the height direction than the first portion P1. The inner edge P2i of the second portion P2 has a larger diameter than the inner edge P1i of the first portion P1. The workpiece W is placed on the electrostatic chuck ESC with its edge region located on the first portion P1 of the edge ring ER. The edge ring ER can be formed from any of various materials such as silicon, silicon carbide, and silicon oxide. A refrigerant flow path 24 is provided inside the second plate 18b. The refrigerant flow path 24 constitutes a temperature control mechanism. Refrigerant is supplied to the refrigerant flow path 24 from the cooler unit located outside the chamber body 12 via pipe 26a. The refrigerant supplied to the refrigerant flow path 24 returns to the cooler unit via pipe 26b. In this way, the refrigerant circulates between the refrigerant flow path 24 and the cooler unit. By controlling the temperature of the refrigerant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled. A plurality of (e.g., three) through holes 25 are formed through the stage ST. The plurality of through holes 25 are formed inside the electrostatic chuck ESC in top view. A lifting pin 25a is inserted into each of these through holes 25. Furthermore, Figure 3 depicts one through hole 25 with one lifting pin 25a inserted. The lifting pin 25a is configured to move up and down within the through hole 25. The workpiece W on the electrostatic chuck ESC is supported by the rising of the lifting pin 25a. A plurality of (e.g., three) through holes 27 are formed on the stage ST, located on the outer side of the electrostatic chuck ESC in top view, penetrating the stage ST (lower electrode LE). A lifting pin 27a is inserted into each of these through holes 27. Furthermore, Figure 3 depicts one through hole 27 with a lifting pin 27a inserted. The lifting pin 27a is configured to move up and down within the through hole 27. The rising of the lifting pin 27a supports the rising of the edge ring ER on the second plate 18b. Furthermore, a gas supply line 28 is provided in the plasma processing apparatus 10. The gas supply line 28 supplies heat transfer gas, such as He gas, from the heat transfer gas supply mechanism to the space between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W. Furthermore, the plasma processing apparatus 10 includes an upper electrode 30. The upper electrode 30 is positioned above the stage ST and faces the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support body 36. The top plate 34 faces the chamber S. A plurality of gas ejection holes 34a are provided on the top plate 34. The top plate 34 may be formed of silicon or quartz. Alternatively, the top plate 34 may be formed by forming a plasma-resistant film such as yttrium oxide on the surface of an aluminum substrate. The support body 36 provides flexible support for the top plate 34. The support body 36 may, for example, contain a conductive material such as aluminum. The support body 36 may have a water-cooling structure. Inside the support body 36, a gas diffusion chamber 36a is provided. A plurality of gas flow holes 36b, communicating with the gas ejection holes 34a, extend downwards from the gas diffusion chamber 36a. Furthermore, a gas inlet 36c is formed in the support body 36 to guide the processed gas into the gas diffusion chamber 36a. A gas supply pipe 38 is connected to the gas inlet 36c. A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow controller group 44. The gas source group 40 includes a plurality of gas sources for a plurality of different gases. The valve group 42 includes a plurality of valves, and the flow controller group 44 includes a plurality of flow controllers, such as a mass flow controller. The plurality of gas sources in the gas source group 40 are connected to the gas supply pipe 38 via corresponding valves in the valve group 42 and corresponding flow controllers in the flow controller group 44. Furthermore, in the plasma processing apparatus 10, an accumulation shield 46 is detachably provided along the inner wall of the chamber body 12. The accumulation shield 46 is also provided on the outer periphery of the support portion 14. The accumulation shield 46 prevents etching byproducts (accumulations) from adhering to the chamber body 12. The accumulation shield 46 can be constructed by coating an aluminum material with a ceramic such as yttrium oxide. An exhaust plate 48 is provided at the bottom of the chamber body 12, between the support portion 14 and the side wall of the chamber body 12. The exhaust plate 48 can be constructed, for example, by coating aluminum with a ceramic such as yttrium oxide. A plurality of holes are formed in the exhaust plate 48, extending along its thickness. An exhaust port 12e is provided below the exhaust plate 48 and within the chamber body 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbomolecular pump. The exhaust device 50 can reduce the pressure of the space within the chamber body 12 to the required vacuum level. Furthermore, an inlet / outlet 12g for the workpiece W is provided on the side wall of the chamber body 12. This inlet / outlet 12g can be opened and closed by a gate valve 54. Furthermore, the plasma processing apparatus 10 further includes a first high-frequency power supply 62 and a second high-frequency power supply 64. The first high-frequency power supply 62 is a power supply that generates a first high frequency for plasma generation. The first high-frequency power supply 62 generates, for example, a high frequency with a frequency of 27 to 100 MHz. The first high-frequency power supply 62 is connected to the upper electrode 30 via a matching device 66. The matching device 66 has circuitry for matching the output impedance of the first high-frequency power supply 62 with the input impedance of the load side (upper electrode 30 side). Furthermore, the first high-frequency power supply 62 can also be connected to the lower electrode LE via the matching device 66. The second high-frequency power supply 64 generates a second high-frequency power supply for feeding ions into the workpiece W. The second high-frequency power supply 64 generates, for example, a high frequency in the range of 400 kHz to 13.56 MHz. The second high-frequency power supply 64 is connected to the lower electrode LE via a matching converter 68. The matching converter 68 has circuitry for matching the output impedance of the second high-frequency power supply 64 with the input impedance of the load side (lower electrode LE side). In the plasma processing apparatus 10, gas from one or more gas sources selected from a plurality of gas sources is supplied to chamber S. Furthermore, the pressure in chamber S is set to a predetermined pressure by the exhaust device 50. Then, the gas in chamber S is excited by a first high frequency from a first high-frequency power supply 62, thereby generating plasma. Subsequently, the workpiece W is processed using the generated active species. Furthermore, ions can also be fed into the workpiece W as needed by a bias voltage based on a second high frequency from a second high-frequency power supply 64. The measuring device will now be described. Figure 4 is a top view of the measuring device viewed from the top surface. Figure 5 is a top view of the measuring device viewed from the bottom surface. The measuring device 100 shown in Figures 4 and 5 includes a base substrate 102. The base substrate 102 is formed of silicon, for example, and has a shape that is the same as the shape of the workpiece W, i.e., a generally disc shape. The diameter of the base substrate 102 is the same as the diameter of the workpiece W, for example, 300 mm. The shape and size of the measuring device 100 are defined by the shape and size of the base substrate 102. Therefore, the measuring device 100 has a shape that is the same as the shape of the workpiece W and has a size that is the same as the size of the workpiece W. Furthermore, a notch 102N (or other markings) is formed on the edge of the base substrate 102. A plurality of first sensors 104A to 104C for measuring electrostatic capacitance are disposed on a substrate 102. The plurality of first sensors 104A to 104C are arranged at equal intervals along the edge of the substrate 102, for example, along the entire circumference of the edge. Specifically, each of the plurality of first sensors 104A to 104C is arranged along the edge of the upper surface side of the substrate 102. The front end face of each of the plurality of first sensors 104A to 104C is along the side surface of the substrate 102. Furthermore, a plurality of second sensors 105A to 105C for electrostatic capacitance measurement are disposed on the substrate 102. The plurality of second sensors 105A to 105C are arranged at equal intervals along the edge of the substrate 102, for example, along the entire circumference of the edge. Specifically, each of the plurality of second sensors 105A to 105C is arranged along the edge of the bottom surface of the substrate. The signal electrode 161 of each of the plurality of second sensors 105A to 105C is along the bottom surface of the substrate 102. Furthermore, the second sensors 105A to 105C and the first sensors 104A to 104C are arranged alternately at 60° intervals in the circumferential direction. A circuit board 106 is disposed at the center of the upper surface of the substrate 102. Wiring groups 108A-108C for electrically connecting the circuit board 106 and a plurality of first sensors 104A-104C are disposed between the circuit board 106 and the plurality of second sensors 105A-105C. Wiring groups 208A-208C for electrically connecting the circuit board 106 and the plurality of second sensors 105A-105C are disposed between the circuit board 106 and the second sensors 105A-105C. The circuit board 106, wiring groups 108A-108C, and wiring groups 208A-208C are covered by an outer casing 103. The first sensor will now be described in detail. Figure 6 is a perspective view showing an example of the sensor. Figure 7 is a cross-sectional view taken along line VII-VII of Figure 6. Figure 8 is a cross-sectional view of the first sensor taken along line VIII-VIII of Figure 7. Figure 9 is a cross-sectional view of the first sensor taken along line IX-IX of Figure 7. Figure 10 is a cross-sectional view of the first sensor taken along line XX of Figure 7. The first sensor (sensor chip) 104 is a sensor used as one of the plurality of first sensors 104A to 104C in the measuring instrument 100, and in one example, it is configured as a chip-shaped part. Furthermore, in the following description, the XYZ orthogonal coordinate system is appropriately referenced. The X direction represents the forward direction of the first sensor 104, the Y direction represents a direction orthogonal to the X direction and the width direction of the first sensor 104, and the Z direction represents a direction orthogonal to both the X and Y directions and the upward direction of the first sensor 104. In Figure 7, the edge ring ER is shown together with the first sensor 104. The first sensor 104 includes a sensor body 140 (sensor section), a first flexible substrate 146, and a second flexible substrate 149. The sensor body 140 includes a signal electrode 141, a shielding electrode 142, and a first ground electrode 143. In one example, the sensor body 140 may also be a MEMS chip manufactured using MEMS (Micro Electro Mechanical Systems) technology. For example, the signal electrode 141, the shielding electrode 142, and the first ground electrode 143 may be formed of conductive materials such as copper or silicon. The signal electrode 141 has a front surface 141a that radially intersects the substrate 101. That is, in the measuring device 100, the front surface 141a of the signal electrode 141 faces the radially outer side of the substrate. In one example, the front surface 141a of the signal electrode 141 is curved along the outer periphery of the measuring device 100. For example, the front surface 141a of the signal electrode 141 has a fixed curvature at any position, which may be the reciprocal of the distance between the central axis AX100 of the measuring device 100 and the front surface 141a. A pad 151 electrically connected to the signal electrode 141 is provided at the upper end of the sensor body 140. The shielding electrode 142 is disposed behind the signal electrode 141, away from it. Furthermore, the shielding electrode 142 extends along the signal electrode 141. The shielding electrode 142 in the example figure has an inner surface portion 142a that curves along the signal electrode 141, and a side edge portion 142b that surrounds the end edge of the signal electrode 141 in the width direction. The inner surface portion 142a of the shielding electrode 142 is also curved, just like the signal electrode 141. For example, the inner surface portion 142a of the shielding electrode 142 has a fixed curvature at any position, which can be the reciprocal of the distance between the central axis AX100 of the measuring device 100 and the inner surface portion 142a. The side edge portion 142b of the shielding electrode 142 protrudes forward from both ends of the inner surface portion 142a in the width direction. The side edge portion 142b is formed along the end edge of the signal electrode 141 in the width direction. A solder pad 152 electrically connected to the shielding electrode 142 is provided on the upper end of the sensor body 140. The first ground electrode 143 is disposed behind the shielding electrode 142, away from the shielding electrode 142. Furthermore, the front surface 143a of the first ground electrode 143 extends along the shielding electrode 142. That is, the front surface 143a of the first ground electrode 143 is a curved surface parallel to the shielding electrode 142. For example, the front surface 143a of the first ground electrode 143 has a fixed curvature at any position on the front surface 143a, which can be the reciprocal of the distance between the central axis AX100 of the measuring device 100 and the front surface 143a. The first ground electrode 143 includes a side edge 143b surrounding the side edge 142b of the shielding electrode 142. The side edge 143b of the first ground electrode 143 protrudes forward from both ends of the front surface 143a in the width direction. The side edge 143b is formed away from the side edge 142b of the shielding electrode 142 and along that side edge 142b. A pad 153 electrically connected to the first ground electrode 143 is provided on the upper end of the sensor body 140. Furthermore, an insulating material 145 with electrical insulation properties is disposed between each of the mutually separated signal electrode 141, shield electrode 142, and first ground electrode 143. As shown in the figure, the insulating material 145 includes a front surface portion 145a, a first intermediate portion 145b, and a second intermediate portion 145c. The front surface portion 145a constitutes the front surface of the sensor body 140. That is, the front surface portion 145a covers the front surface 141a of the signal electrode 141, the front portion of the side edge portion 142b of the shield electrode 142, and the front portion of the side edge portion 143b of the first ground electrode 143. The first intermediate portion 145b is disposed between the signal electrode 141 and the shield electrode 142. In the example shown in the figure, the first intermediate portion 145b is also disposed between the solder pad 151 connected to the signal electrode 141 and the solder pad 152 connected to the shield electrode 142. The second intermediate portion 145c is disposed between the shielding electrode 142 and the first grounding electrode 143. In the example shown, the second intermediate portion 145c is also disposed between the solder pad 152 connected to the shielding electrode 142 and the solder pad 153 connected to the first grounding electrode 143. The insulating material 145 may be formed, for example, from borosilicate glass, quartz, etc. Thus, from a top view, the front surface 141a of the signal electrode 141, the front surface (inner surface portion 142a) of the shielding electrode 142, and the front surface 143a of the first ground electrode 143 are all curved surfaces parallel to the curved surface formed by the outer periphery of the substrate 101. Furthermore, the signal electrode 141, the shielding electrode 142, and the first ground electrode 143 all extend from the upper end to the lower end of the sensor body 140. The signal electrode 141, the shielding electrode 142, and the first ground electrode 143 are arranged apart from each other by an insulating material 145 extending from the upper end to the lower end of the sensor body 140. The first flexible substrate 146 extends along the lower surface of the columnar sensor body 140. For example, the first flexible substrate 146 is fixed to the lower surface of the sensor body 140 by adhesive members such as an electrically insulating adhesive or adhesive sheet. Here, the lower surface of the sensor body 140 is electrically insulated from the outside. Furthermore, the first flexible substrate 146 includes a region having the same planar shape as the sensor body 140, and a terminal region 146a protruding rearward from the center of the rear end of that region. In one example, the first flexible substrate 146 includes a substrate body 147 and a second ground electrode 148. The substrate body 147 is formed of an electrically insulating material such as polyimide. The second ground electrode 148 is formed as a plate shape slightly smaller than the substrate body 147 and is covered by the substrate body 147. That is, the upper surface, lower surface, and side surfaces of the second ground electrode 148 are all covered by the substrate body 147. The second grounding electrode 148 may be formed, for example, from a conductive metal such as copper. The second ground electrode 148 extends along the lower surface of the sensor body 140. Therefore, only the electrically insulating substrate body 147 fills the space between the second ground electrode 148 and the sensor body 140. In the terminal region 146a, an opening 147a is formed in the substrate body 147, and a portion of the second ground electrode 148 is exposed as a solder pad 148a. Furthermore, in the terminal region 146a, solder pads 146c and 146d corresponding to the signal electrode 141 and the shielding electrode 142, respectively, are formed. The second flexible substrate 149 has the same planar shape as the sensor body 140 and extends along the upper surface of the sensor body 140. In one example, the second flexible substrate 149 is formed of an electrically insulating material such as polyimide. Openings 149a corresponding to solder pads 151-153 are formed on the second flexible substrate 149, thereby exposing the solder pads 151-153 to the outside. The second flexible substrate 149 can also be fixed to the upper surface of the sensor body 140 by adhesive members such as electrically insulating adhesives or adhesive sheets. In this case, the upper surface of the sensor body 140 is electrically insulated from the outside. When the first sensor 104 is used as a sensor in the measuring device 100, as described below, the signal electrode 141 is connected to wiring 181, the shielding electrode 142 is connected to wiring 182, and the first ground electrode 143 is connected to wiring 183. Furthermore, in one example, the wiring of the signal electrode 141 connected to the pad 151 can be connected to wiring 181 via pad 146c. Also, the wiring of the shielding electrode 142 connected to the pad 152 can be connected to wiring 182 via pad 146d. Furthermore, the wiring of the first ground electrode 143 connected to the pad 153 can be connected to wiring 183 via pad 148a of the second ground electrode 148. The second sensor will now be described in detail. Figure 11 is a partial enlarged view of Figure 5, showing one second sensor. The second sensor 105 has a signal electrode 161. The edge of the signal electrode 161 is partially arc-shaped. That is, the signal electrode 161 has a planar shape defined by two arcs with different radii centered on the central axis AX100, namely an inner edge 161a and an outer edge 161b. The outer radially outer edge 161b of the signal electrode 161 of each of the plurality of second sensors 105A to 105C extends on a common circle. Furthermore, the inner radially inner edge 161a of the signal electrode 161 of each of the plurality of second sensors 105A to 105C extends on another common circle. The curvature of a portion of the edge of the signal electrode 161 is consistent with the curvature of the edge of the electrostatic chuck ESC. In one exemplary embodiment, the curvature of the outer edge 161b of the signal electrode 161 forming the radially outer edge coincides with the curvature of the edge of the electrostatic chuck ESC. Furthermore, the center of curvature of the outer edge 161b, i.e., the center of the circle extending from the outer edge 161b, shares a central axis AX100. In one exemplary embodiment, the second sensor 105 further includes a shielding electrode 162 surrounding the signal electrode 161. The shielding electrode 162 is frame-shaped and surrounds the entire circumference of the signal electrode 161. The shielding electrode 162 and the signal electrode 161 are separated from each other by an insulating region 164 between them. In another exemplary embodiment, the second sensor 105 further includes an electrode 163 surrounding the shielding electrode 162 on the outside. The electrode 163 is frame-shaped and surrounds the entire circumference of the shielding electrode 162. The shielding electrode 162 and the electrode 163 are separated from each other by an insulating region 165 between them. The configuration of the circuit board 106 will now be described. Figure 12 is a diagram illustrating the configuration of the circuit board of the measuring device. The circuit board 106 includes a high-frequency oscillator 171, a plurality of C / V conversion circuits 172A to 172C, a plurality of C / V conversion circuits 272A to 272C, an A / D (analog to digital) converter 173, a processor 174, a memory device 175, a communication device 176, and a power supply 177. In one example, the processor 174, the memory device 175, etc., constitute an arithmetic unit. Furthermore, the circuit board 106 includes a temperature sensor 179. The temperature sensor 179 outputs a signal corresponding to the detected temperature to the processor 174. For example, the temperature sensor 179 can acquire the temperature of the environment surrounding the measuring device 100. A plurality of first sensors 104A to 104C are connected to the circuit board 106 via corresponding wiring groups 108A to 108C. Furthermore, the plurality of first sensors 104A to 104C are connected to corresponding C / V conversion circuits 172A to 172C via wirings included in their respective wiring groups. A plurality of second sensors 105A to 105C are connected to the circuit board 106 via corresponding wiring groups 208A to 208C. Furthermore, the plurality of second sensors 105A to 105C are connected to corresponding C / V conversion circuits 272A to 272C via wirings included in their respective wiring groups. The following describes a first sensor 104 with the same configuration as each of the first sensors 104A to 104C, a wiring group 108 with the same configuration as each of the wiring groups 108A to 108C, and a C / V conversion circuit 172 with the same configuration as each of the C / V conversion circuits 172A to 172C. Furthermore, a second sensor 105 with the same configuration as each of the second sensors 105A to 105C, a wiring group 208 with the same configuration as each of the wiring groups 208A to 208C, and a C / V conversion circuit 272 with the same configuration as each of the C / V conversion circuits 272A to 272C will be described. Wiring group 108 includes wirings 181 to 183. One end of wiring 181 is electrically connected to pad 151, which is connected to signal electrode 141, and the other end of wiring 181 is connected to C / V conversion circuit 172. Wiring 182 is electrically connected to pad 152, which is connected to shield electrode 142, and the other end of wiring 182 is connected to C / V conversion circuit 172. Wiring 183 is electrically connected to pad 153, which is electrically connected to first ground electrode 143 and second ground electrode 148. Wiring 183 is connected to ground potential line GL, which is connected to ground G of circuit board 106. Alternatively, wiring 183 can also be connected to ground potential line GL via switch SWG. Wiring group 208 includes wirings 281 to 283. One end of wiring 281 is electrically connected to signal electrode 161, and the other end of wiring 281 is connected to C / V conversion circuit 272. Wiring 282 has one end electrically connected to shielding electrode 162, and the other end of wiring 282 is connected to C / V conversion circuit 272. Wiring 283 has one end connected to electrode 163. Wiring 283 is electrically connected to ground potential line GL, which is connected to ground G of circuit board 106. Furthermore, wiring 283 can also be connected to ground potential line GL via switch SWG. A high-frequency oscillator 171 is connected to a power source 177, such as a battery, and is configured to receive power from the power source 177 to generate a high-frequency signal. Furthermore, the power source 177 is also connected to a processor 174, a memory device 175, and a communication device 176. The high-frequency oscillator 171 has a plurality of output lines. The high-frequency oscillator 171 transmits the generated high-frequency signal to wirings 181 and 182, and wirings 281 and 282, via the plurality of output lines. Therefore, the high-frequency oscillator 171 is electrically connected to the signal electrode 141 and the shielding electrode 142 of the first sensor 104, and the high-frequency signal from the high-frequency oscillator 171 is transmitted to the signal electrode 141 and the shielding electrode 142. Also, the high-frequency oscillator 171 is electrically connected to the signal electrode 161 and the shielding electrode 162 of the second sensor 105, and the high-frequency signal from the high-frequency oscillator 171 is transmitted to the signal electrode 161 and the shielding electrode 162. At the input of C / V conversion circuit 172, a wiring 181 connected to pad 151 and a wiring 182 connected to pad 152 are connected. That is, at the input of C / V conversion circuit 172, the shielding electrode 142 and the signal electrode 141 of the first sensor 104 are connected. Also, at the input of C / V conversion circuit 272, the signal electrode 161 and the shielding electrode 162 are connected. C / V conversion circuits 172 and 272 are configured to generate a voltage signal with an amplitude corresponding to the potential difference at their inputs and output the voltage signal. C / V conversion circuit 172 generates a voltage signal corresponding to the electrostatic capacitance formed by the corresponding first sensor 104. That is, the larger the electrostatic capacitance connected to the signal electrode of C / V conversion circuit 172, the larger the voltage of the voltage signal output by C / V conversion circuit 172. Similarly, the larger the electrostatic capacitance of the signal electrode connected to the C / V conversion circuit 272, the larger the voltage of the voltage signal output by the C / V conversion circuit 272. The connections of the high-frequency oscillator 171, wiring 181 and 182, and the C / V conversion circuit 172 are described in more detail. Figure 11 is a circuit diagram showing the connections of the high-frequency oscillator 171, wiring 181 and 182, and the C / V conversion circuit 172. As shown in Figure 13, a resistor 171a is connected between the high-frequency oscillator 171 and wiring 182. A phase adjustment circuit 171d, including a variable resistor 171b and a variable capacitor 171c, is connected between the high-frequency oscillator 171 and wiring 181. A portion of the C / V conversion circuit 172 has an amplifier circuit 172a that includes an operational amplifier and resistors. In the amplifier circuit 172a, wiring 181 is input to the inverting input of the operational amplifier, and wiring 182 is input to the non-inverting input of the operational amplifier. Furthermore, the inverting input and output of the operational amplifier are connected via resistors. Amplifier circuit 172a amplifies the potential difference between the signal from signal electrode 141 and the signal from shield electrode 142 input to C / V conversion circuit 172. The high-frequency oscillator 171, wiring 281 and 282, and C / V conversion circuit 272 are similarly connected to the high-frequency oscillator 171, wiring 181 and 182, and C / V conversion circuit 172. That is, a resistor is connected between the high-frequency oscillator 171 and wiring 282. A variable impedance circuit, including a variable resistor and a variable capacitor, is connected between the high-frequency oscillator 171 and wiring 281. A portion of the C / V conversion circuit 272 has an amplifier circuit including an operational amplifier and a resistor. In the amplifier circuit, wiring 281 is input to the inverting input of the operational amplifier, and wiring 282 is input to the non-inverting input of the operational amplifier. Furthermore, the inverting input and output of the operational amplifier are connected via a resistor. In the circuit configuration described above, the amplitude of the signal from the signal electrode 141 can be changed by altering the resistance value of the variable resistor 171b in the phase adjustment circuit 171d. Furthermore, the phase of the signal from the signal electrode 141 can be changed by altering the capacitance value of the variable capacitor 171c in the phase adjustment circuit 171d. In one exemplary embodiment, the admittance of the phase adjustment circuit 171d is adjusted by using the processor 174 to adjust (control) the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c. For example, as a so-called zero-point adjustment, the processor 174 can adjust the resistance value of the variable resistor 171b and the capacitance of the variable capacitor 171c in the phase adjustment circuit 171d to make the voltage signal output from the C / V conversion circuit 172 zero. Similarly, the resistance value of the variable resistor 171b and the capacitance of the variable capacitor 171c in the phase adjustment circuit 171d can also be adjusted to make the voltage signal output from the C / V conversion circuit 272 zero. The input of A / D converter 173 is connected to the outputs of C / V conversion circuit 172 and C / V conversion circuit 272. A / D converter 173 is also connected to processor 174. A / D converter 173 is controlled by control signals from processor 174, converting the output signals (voltage signals) of C / V conversion circuit 172 and C / V conversion circuit 272 into digital values, which are then output as detected values ​​to processor 174. A memory device 175 is connected to the processor 174. The memory device 175 is a volatile memory or other memory device, for example configured to store measurement data. Furthermore, another memory device 178 is connected to the processor 174. The memory device 178 is a non-volatile memory or other memory device, for example storing a program that is read and executed by the processor 174. Communication device 176 is a communication device based on any wireless communication standard. For example, communication device 176 is based on Bluetooth (registered trademark). Communication device 176 is configured to store measurement data in wireless transmission memory device 175. The processor 174 is configured to control various parts of the measuring device 100 by executing the aforementioned program. For example, the processor 174 controls the supply of high-frequency signals from the high-frequency oscillator 171 to the shielding electrode 142, signal electrode 141, signal electrode 161, and shielding electrode 162. Furthermore, the processor 174 controls the power supply from the power supply 177 to the memory device 175, the power supply from the power supply 177 to the communication device 176, and so on. Furthermore, by executing the aforementioned program, the processor 174 acquires the measured values ​​of the first sensor 104 and the second sensor 105 based on the detected values ​​input from the A / D converter 173. In one embodiment, when the detected value output from the A / D converter 173 is set to X, the processor 174 acquires the measured value based on the detected value in a manner that the measured value is proportional to (a·X + b). Here, a and b are constants that vary depending on circuit states, etc. The processor 174 may, for example, have a defined expression (function) such that the measured value is a value proportional to (a·X+b). In the measuring device 100 described above, when the measuring device 100 is positioned within the area surrounded by the edge ring ER, a plurality of signal electrodes 141 and shielding electrodes 142 face each other to the inner edge of the edge ring ER. The measured value, generated based on the potential difference between the signals of the signal electrodes 141 and the signals of the shielding electrodes 142, represents the electrostatic capacitance reflecting the distance between each of the plurality of signal electrodes 141 and the edge ring ER. Furthermore, the electrostatic capacitance C is represented by C = εS / d. ε is the dielectric constant of the medium between the front surface 141a of the signal electrode 141 and the inner edge of the edge ring ER, S is the area of ​​the front surface 141a of the signal electrode 141, and d can be considered as the distance between the front surface 141a of the signal electrode 141 and the inner edge of the edge ring ER. Therefore, measurement data reflecting the relative positional relationship between the measuring device 100 and the edge ring ER of the simulated workpiece W can be obtained using the measuring device 100. For example, the greater the distance between the front surface 141a of the signal electrode 141 and the inner edge of the edge ring ER, the smaller the plurality of measurement values ​​obtained by the measuring device 100. Therefore, the offset of each signal electrode 141 in each radial direction of the edge ring ER can be determined based on the measured values ​​representing the electrostatic capacitance of each signal electrode 141 of the first sensors 104A to 104C. Furthermore, the error in the transport position of the measuring device 100 can be determined based on the offset of each signal electrode 141 of the first sensors 104A to 104C in each radial direction. Furthermore, with the measuring device 100 mounted on the electrostatic chuck ESC, a plurality of signal electrodes 161 and shielding electrodes 162 face each other to the electrostatic chuck ESC. As described above, the electrostatic capacitance C is represented by C = εS / d. ε is the dielectric constant of the medium between the signal electrodes 161 and the electrostatic chuck ESC, d is the distance between the signal electrodes 161 and the electrostatic chuck ESC, and S can be considered as the area of ​​overlap between the signal electrodes 161 and the electrostatic chuck ESC when viewed from above. The area S varies depending on the relative positional relationship between the measuring device 100 and the electrostatic chuck ESC. Therefore, based on the measuring device 100, measurement data reflecting the relative positional relationship between the measuring device 100 and the electrostatic chuck ESC of the simulated workpiece W can be obtained. In one example, when the measuring device 100 is moved to a predetermined moving position, i.e., on the electrostatic chuck ESC where the center of the measuring device 100 coincides with the center of the measuring device 100, the outer edge 161b of the signal electrode 161 may coincide with the edge of the electrostatic chuck ESC. In this case, for example, when the signal electrode 161 shifts radially outward relative to the electrostatic chuck ESC due to the shift of the measuring device 100's moving position from the predetermined moving position, the area S will become smaller. That is, the electrostatic capacitance measured by the signal electrode 161 will be smaller than the electrostatic capacitance when the measuring device 100 is moved to the predetermined moving position. Therefore, the offset of each signal electrode 161 in each radial direction of the electrostatic chuck ESC can be determined based on the measured values ​​of the electrostatic capacitance of the signal electrodes 161 of each of the second sensors 105A to 105C. Furthermore, the error in the conveying position of the measuring device 100 can be determined based on the offset of the signal electrode 161 of each of the second sensors 105A to 105C in each radial direction. As described above, the measuring device 100 includes a circular substrate 101, a first sensor 104 disposed on the substrate 101, and a circuit board 106 disposed on the substrate 101. The first sensor 104 includes a sensor body 140 comprising a signal electrode 141, a shielding electrode 142, and a first ground electrode 143. The signal electrode 141 has a front surface that radially intersects the substrate 101. The shielding electrode 142 is disposed behind the signal electrode 141 and extends along the signal electrode 141. The first ground electrode 143 is disposed behind the shielding electrode 142. The circuit board 106 includes a high-frequency oscillator 171 configured to impart high-frequency signals to the signal electrode 141 and the shielding electrode 142 respectively; and a C / V conversion circuit 172 that generates a voltage signal corresponding to the electrostatic capacitance formed by the signal electrode 141. The C / V conversion circuit 172 includes an amplifier circuit 172a comprising an operational amplifier. A high-frequency oscillator 171 is connected to the non-inverting input terminal of an operational amplifier such that the high-frequency signal applied to the signal electrode 141 is input to the non-inverting input terminal of the operational amplifier. Similarly, the high-frequency oscillator 171 is connected to the inverting input terminal of the operational amplifier such that the high-frequency signal applied to the signal electrode 141 is input to the inverting input terminal of the operational amplifier. The first sensor 104 includes a second ground electrode 148 extending along the lower surface of the sensor body 140. The signal electrode 141, shielding electrode 142, and first ground electrode 143 of the sensor body 140 all extend to the lower end of the sensor body 140. Only insulating material is filled between the second ground electrode 148 and the sensor body 140. In the measuring device 100 of the above embodiment, the signal electrode 141 is shielded from the rear by the shielding electrode 142 and the first grounding electrode 143, and from the bottom by the second grounding electrode 148. Therefore, according to the first sensor 104, the electrostatic capacitance can be measured with high directivity in a specific direction, that is, in the direction in which the front surface of the signal electrode 141 faces. For example, to improve the shielding of the sensor body 140 relative to the surface below, it is considered to also place the shielding electrode below the sensor body 140. However, when the shielding electrode extends along the lower surface of the sensor body 140, ESD may damage the operational amplifier through the shielding electrode. In an exemplary embodiment, no shielding electrode is placed below the sensor body 140, and the shielding electrode 142 constituting the sensor body 140 does not include a portion extending along the lower surface of the sensor body 140. That is, only insulating material is filled between the second ground electrode 148 and the sensor body 140, thus suppressing ESD damage to the operational amplifier through the shielding electrode. In one exemplary embodiment, viewed from above, the front surfaces of the signal electrode 141, the shield electrode 142, and the first ground electrode 143 can all be curved surfaces parallel to the curved surface formed on the outer periphery of the substrate 101. In this configuration, each of the signal electrode, shield electrode, and first ground electrode is also arranged parallel to the edge ring. Therefore, a highly accurate measurement value representing the distance to the edge ring can be obtained. In one exemplary embodiment, the first sensor 104 may include an insulating first flexible substrate 146 extending along the lower surface of the sensor body 140 and including a second ground electrode 148. In this configuration, the second ground electrode 148 can be easily positioned below the sensor body 140. In one exemplary embodiment, the first sensor 104 may include an insulating second flexible substrate 149 extending along the upper surface of the sensor body 140. In this configuration, the insulation of the upper surface of the sensor body 140 can be guaranteed. In one exemplary embodiment, the front surface 141a of the signal electrode 141 is covered with an insulating material 145 having electrical insulating properties. In this configuration, ESD is suppressed from damaging the operational amplifier via the signal electrode 141. As described above, various embodiments of the present invention have been presented in this specification for illustrative purposes. It should be understood that various modifications can be made without departing from the scope and spirit of the invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting, and the true scope and spirit are indicated by the appended claims. 1: Processing system 2a, 2b, 2c, 2d: Base 4a, 4b, 4c, 4d: Container 6D: Drive unit 6S: Sensor 6T: Support platform 10: Plasma processing device 12: Chamber body 12e: Exhaust port 12g: Loading / unloading port 14: Support section 18a: First plate 18b: Second plate 22: DC power supply 23: Switch 24: Refrigerant flow path 25: Through hole 25a: Lifting pin 26a: Piping 26b: Piping 27: Through hole 27a: Lifting pin 28: Gas supply line 30: Upper electrode 32: Insulating shielding component 34: Top plate 34a: Gas ejection port 36: Support body 36a: Gas diffusion chamber 36b : Gas flow port 36c: Gas inlet 38: Gas supply pipe 40: Gas source group 42: Valve group 44: Flow controller group 46: Accumulation shield 48: Exhaust plate 50: Exhaust device 52: Exhaust pipe 54: Gate valve 62: First high-frequency power supply 64: Second high-frequency power supply 66: Matching device 68: Matching device 100: Measuring device 102: Substrate 102N: Notch 103: Outer cover 104: First sensor 104A, 104B, 104C: First sensor 105: Second sensor 105A, 105B, 105C: Second sensor 106: Circuit board 108: Wiring group 108A, 108B, 108 C: Wiring group 140: Sensor body 141: Signal electrode 141a: Front surface 142: Shielding electrode 142a: Inner surface portion 142b: Side edge portion 143: First ground electrode 143a: Front surface 143b: Side edge portion 145: Insulating material 145a: Front surface portion 145b: First middle portion 145c: Second middle portion 146: First flexible substrate 146a: Terminal area 146c: Solder pad 146d: Solder pad 147: Substrate body 147a: Opening 148: Second ground electrode 148a: Solder pad 149: Second flexible substrate 149a: Opening 151: Solder pad 152: Solder pad 153: Solder pad 16 1: Signal electrode 161a: Inner edge 161b: Outer edge 162: Shielding electrode 163: Electrode 164: Insulating area 165: Insulating area 171: High-frequency oscillator 171a: Resistor 171b: Variable resistor 171c: Variable capacitor 171d: Phase adjustment circuit 172: C / V conversion circuit 172A, 172B, 172C: C / V conversion circuit 172a: Amplifier circuit 173: A / D converter 174: Processor 175: Memory device 176: Communication device 177: Power supply 178: Memory device 181: Wiring 182: Wiring 183: Wiring 208: Wiring group 208A, 208B208C: Wiring group; 272: C / V conversion circuit; 272A, 272B, 272C: C / V conversion circuit; 281, 282, 283: Wiring; AN: Aligner; AX100: Center axis; ER: Edge ring; ESC: Electrostatic chuck; G: Ground; GL: Ground potential line; MC: Control unit; LE: Lower electrode; LL1, LL2: Load locking module; LM: Carrier module; P1: Part 1; P1i: Inner edge; P2: Part 2; P2i: Inner edge; PM1, PM2, PM3, PM4, PM5, PM6: Process module; S: Chamber; S1: Conveying system; ST: Platform; SWG: Switch; TF: Conveying module; TU1: Conveying device; TU2: Conveying device; TUa: Conveying arm; W: Workpiece; WN: Notch; X: Direction; Y: Direction; Z: Direction; Figure 1 is a diagram illustrating the processing system. Figure 2 is a perspective view illustrating the alignment device. Figure 3 is a diagram illustrating an example of a plasma processing apparatus. Figure 4 is a top view showing an example of a measuring device viewed from the top surface. Figure 5 is a top view showing an example of a measuring device viewed from the bottom surface. Figure 6 is a perspective view showing an example of a first sensor. Figure 7 is a cross-sectional view along line VII-VII of Figure 6. Figure 8 is a cross-sectional view along line VIII-VIII of Figure 7. Figure 9 is a cross-sectional view along line IX-IX of Figure 7. Figure 10 is a cross-sectional view along line XX of Figure 7. Figure 11 is an enlarged view of the second sensor in Figure 5. Figure 12 is a diagram illustrating the structure of the circuit board of the measuring device. Figure 13 is a diagram illustrating the detailed structure of the circuit board of the measuring device. 141: Signal electrode 141a: Front surface 142: Shielding electrode 142a: Inner surface portion 143: First grounding electrode 143a: Front surface 145: Insulating materials 145a: Front surface portion 145b: First Middle Section 145c: Second Middle Section 146: First flexible substrate 146a: Terminal area 147:Substrate body 148: Second grounding electrode 148a: solder pad 149: Second flexible substrate 149a: Opening 153: Solder pad ER: Edge ring P1: Part 1 P1i: Inner edge P2: Part 2 P2i: Inner edge X: Direction Y: direction Z: Direction

Claims

1. A measuring device comprising: a circular substrate, a sensor chip disposed on the substrate, and a circuit board disposed on the substrate; the sensor chip comprising a sensor portion including: a signal electrode having a front surface radially intersecting the substrate; a shielding electrode disposed behind the signal electrode and extending along the signal electrode; and a first ground electrode disposed behind the shielding electrode; the circuit board comprising: a high-frequency oscillator configured to impart high-frequency signals to the signal electrode and the shielding electrode respectively; and a C / V conversion circuit generating a voltage signal corresponding to the electrostatic capacitance formed by the signal electrode; the C / V conversion circuit having an amplification circuit including an operational amplifier; the high-frequency oscillator being connected to the non-inverting input terminal such that the high-frequency signal imparted to the signal electrode is input to the non-inverting input terminal of the operational amplifier, and being connected to the inverting input terminal such that the high-frequency signal imparted to the signal electrode is input to the inverting input terminal of the operational amplifier; The aforementioned sensor chip includes a second ground electrode extending along the lower surface of the aforementioned sensor portion; the aforementioned signal electrode, the aforementioned shielding electrode, and the aforementioned first ground electrode of the aforementioned sensor portion all extend to the lower end of the aforementioned sensor portion; the space between the aforementioned second ground electrode and the aforementioned sensor portion is filled only with an insulating material.

2. The measuring device of claim 1, wherein the shielding electrode constituting the sensor portion does not include a portion extending along the lower surface of the sensor portion.

3. The measuring instrument as claimed in claim 1 or 2, wherein, in top view, the front surface of the signal electrode, the front surface of the shielding electrode, and the front surface of the first ground electrode are all curved surfaces parallel to the curved surface formed by the outer periphery of the substrate.

4. The measuring device of claim 1 or 2, wherein the sensor chip has an insulating first flexible substrate extending along the lower surface of the sensor portion and including the second ground electrode.

5. The measuring device of claim 3, wherein the sensor chip has an insulating first flexible substrate extending along the lower surface of the sensor portion and including the second ground electrode.

6. The measuring device of claim 1 or 2, wherein the sensor chip has an insulating second flexible substrate extending along the upper surface of the sensor portion.

7. The measuring device of claim 5, wherein the sensor chip has an insulating second flexible substrate extending along the upper surface of the sensor portion.

8. The measuring device as claimed in claim 1 or 2, wherein the front surface of the aforementioned signal electrode is covered with an insulating material having insulating properties.

9. The measuring device of claim 7, wherein the front surface of the aforementioned signal electrode is covered with an insulating material having insulating properties.

10. The measuring device of claim 8, wherein the insulating material covering the front surface of the signal electrode is formed of borosilicate glass or quartz.

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