CN115083783B - Computable capacitance structure - Google Patents

Abstract

The embodiment of the disclosure provides a calculable capacitance structure, including a plurality of calculable capacitors connected in parallel and symmetrically arranged, each of the calculable capacitors includes respectively: the two ends of each main electrode are respectively led out of the capacitor through leads, and part of main electrodes are shared between two adjacent calculable capacitors; and the shielding electrode can move in a space formed by surrounding the main electrodes, so that the capacitance of the output of the capacitor can be calculated through adjustment, and the linear output of the capacitance with respect to displacement is realized. According to the embodiment of the disclosure, the main electrode is multiplexed to serve as the capacitor plate, so that the measuring range of the computable capacitor structure can be expanded to multiple times in the prior art under the condition that the longitudinal length is kept unchanged, the structure is compact, and a large measuring range can be realized in a small volume. Meanwhile, the plurality of computable capacitors are not interfered with each other, and the change relation between the capacitance and the displacement is independent of each other, so that higher sensitivity can be kept in the whole range.

Description

Computable capacitance structure

Technical field

Embodiments of the present disclosure relate to the technical field of capacitors, and in particular to a calculable capacitance structure.

Background technique

Calculable capacitance is based on a new theorem in electrostatics proposed by AM Thompson and DGL Lampard in 1956. The theorem is briefly described as follows: For an infinitely long conductive cylinder with any shape cross-section, it is isolated at four positions by four infinitesimal insulating gaps, making it four electrodes α, β, γ, δ, As shown in Figure 1. An opposing set of electrodes forms a capacitor, and four electrodes form two capacitors. Assume that the unit length capacitances of these two capacitors are C ₁ and C 2 respectively. There is a relationship between _{C 1 and} C ₂ :

Among them, C ₀ =(ε ₀ ε _r )/π·ln2 is a determinable constant value. ε ₀ is the vacuum dielectric constant, ε _r is the relative dielectric constant of the medium in the inner space of the infinitely long conductive cylinder. C ₁ and C ₂ are called cross capacitance, and the average value of C ₁ and C ₂ Calculate according to the following formula:

When C ₁ and C ₂ are relatively close, the error between the average capacitance and C ₀ is a small amount above the second order. When the longitudinal length of the capacitor is l, the output capacitance is The output capacitance is only related to the axial length l of the capacitor.

The characteristic of calculable capacitance is that its output capacitance value is proportional to its axial length and has nothing to do with the shape and geometric dimensions of the cross-section. It transfers the capacitance accuracy to the length accuracy, so it has high stability and accuracy in the capacitance output. . Since the 1970s, calculable capacitance has been used by domestic and foreign metrology institutions as a standard for reproducing parameters such as capacitance, resistance, and inductance in electromagnetic metrology. Among them, the reproduction accuracy of the United States, Australia, Japan, and the United Kingdom is ±10 ^-7 or above. In addition to being used to reproduce international standard units, calculable capacitance can also be used as a capacitor in high-precision capacitive sensors, including micrometer pressure gauges and precision systems for measuring the dielectric constant of liquids.

A typical computable capacitance structure is shown in Figure 2. Four very close cylinders constitute the four main electrodes 02 from which the capacitance can be calculated. Two cylinders with relatively small diameters are inserted into the gaps between the four main electrodes, serving as the upper shield electrode 01 and the lower shield electrode 03 respectively. The length l that actually participates in forming the capacitance is the length of the unshielded part of the main electrode 02, that is, the distance L between the two shielding electrode ends. The distance L can be accurately measured by the laser interference method (in Figure 2, 04 is a plane mirror installed at the bottom of the upper fine-tuning electrode 01, 05 is a concave mirror installed at the top of the lower shielding electrode 03, and 06 is the incident laser). . Therefore, according to the formula C = C ₀ l, the output capacitance C can be accurately calculated.

Current computable capacitors mainly work in a vacuum environment. The relationship between the output capacitance and the longitudinal length l of the capacitor is C=C ₀ l, C ₀ =1.95354902 pF/m. The measuring range of the capacitor is determined by the longitudinal length of the capacitor. For example, to achieve a capacitance of 0.1pF, the required longitudinal length of the capacitor is at least 52mm. To obtain a larger range, the longitudinal length of the capacitor needs to be expanded, which will result in the overall size of the capacitor being too large, which is not conducive to production control and system integration.

Contents of the invention

The present disclosure aims to solve one of the technical problems in the related art, at least to a certain extent.

To this end, the present disclosure implements a simple and compact structure, a large-range, small-volume calculable capacitance structure that can maintain high sensitivity within the full range: including multiple calculable capacitors connected in parallel and symmetrically arranged, each of which The above calculable capacitors include respectively:

Several main electrodes arranged parallel and symmetrically to each other, capacitors are drawn out from both ends of each main electrode through leads respectively, and a portion of the main electrode is shared between two adjacent calculable capacitors; and

A shielding electrode that can move within a space formed by a plurality of main electrodes, thereby adjusting the capacitance output by the calculable capacitor to achieve a linear output of capacitance with respect to displacement.

Compared with the existing technology, the calculable capacitance structure provided by the embodiments of the present disclosure has the following characteristics and beneficial effects:

The computable capacitance structure provided by the embodiment of the present disclosure multiplexes main electrodes as capacitor plates, uses several main electrodes to form multiple computable capacitors, and connects all the computable capacitors in parallel. Under the condition of keeping the longitudinal length unchanged, the range of the calculable capacitance structure can be expanded to many times the original. The structure is compact and a large range can be achieved in a small volume. At the same time, multiple calculable capacitors do not interfere with each other, and the relationship between capacitance and displacement changes is independent of each other, so it can maintain high sensitivity throughout the entire range.

In some embodiments, the calculable capacitance structure further includes an electrode sleeve, a plurality of first through holes and second through holes are respectively formed in the electrode sleeve, and each of the shielding electrodes can be connected to a corresponding one of the first through holes. The through hole moves along the axis of the first through hole, and each main electrode is inserted into a corresponding second through hole and remains relatively stationary with the electrode sleeve.

In some embodiments, each of the shielding electrodes includes a first electrode and a second electrode, and the first electrode and the second electrode can be independently disposed along the corresponding first through hole. The axis of the first through hole moves.

In some embodiments, the dielectric constant of the first electrode is greater than the dielectric constant of the second electrode.

In some embodiments, the second electrode and the electrode sleeve are kept relatively stationary, and the capacitance of the calculable capacitor output is roughly adjusted by moving the first electrode in the first through hole. ; When all of the second electrodes are located outside the electrode sleeve and the first electrode enters the first through hole to the maximum displacement, the capacitance output by the calculable capacitor is the largest.

In some embodiments, the first electrode and the electrode sleeve are kept relatively stationary, and the capacitance output by the calculable capacitor is finely adjusted by moving the second electrode in the first through hole. ; When all of the first electrodes are located outside the electrode sleeve, and the second electrode enters the first through hole to the maximum displacement, the capacitance output by the calculable capacitor is the smallest.

In some embodiments, the first electrode enters and exits the first through hole from one end of the electrode sleeve, and the second electrode enters and exits the first through hole from the other end of the electrode sleeve.

In some embodiments, the main electrode and the second electrode are made of the same or different conductor materials, and the electrode sleeve and the second electrode are made of the same insulating material or semiconductor material.

In some embodiments, the calculable capacitance structure is provided with a total of 9 main electrodes and 4 shielding electrodes to form 4 calculable capacitors, and the 9 main electrodes are arranged in a 3×3 Arranged in array form, two adjacent calculable capacitors share two main electrodes, and the main electrode located in the center is shared by four calculable capacitors for output capacitance, and the main electrode located in the center The main electrodes whose electrodes are arranged diagonally are connected in parallel, and the remaining main electrodes are all grounded.

In some embodiments, the nine main electrodes are identical.

Description of the drawings

Figure 1 is a schematic diagram of the principle of calculable capacitance.

Figure 2 is a schematic structural diagram of an existing computable capacitor.

FIG. 3 is a schematic structural diagram of a calculable capacitance structure provided by an embodiment of the present disclosure.

FIG. 4 is a top view of a calculable capacitance structure provided by an embodiment of the present disclosure.

FIG. 5 is a schematic diagram of electrical connections of a calculable capacitance structure provided by an embodiment of the present disclosure.

FIG. 6 is a schematic structural diagram of a calculable capacitance structure provided with an electrode sleeve according to an embodiment of the present disclosure.

In the picture:

1—shielding electrode, 11—coarse adjustment electrode, 12—fine adjustment electrode, 2—main electrode, 21 to 24—main electrode, 3—electrode cover.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

On the contrary, this application covers any alternatives, modifications, equivalent methods and solutions that fall within the spirit and scope of this application as defined by the claims. Furthermore, in order to enable the public to have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. A person skilled in the art may fully understand the present application without these detailed descriptions.

Referring to Figure 3, the calculable capacitance structure provided by the embodiment of the present disclosure includes multiple calculable capacitors connected in parallel and arranged symmetrically. Each calculable capacitor includes:

Several main electrodes 2 are arranged parallel to each other and symmetrically. Capacitors are drawn out through leads at both ends of each main electrode 2, and part of the main electrode 2 is shared between two adjacent calculable capacitors; and

The shield electrode 1 can move in the space formed by several main electrodes 2, thereby adjusting the capacitance of the calculable capacitor output and realizing the linear output of the capacitance with respect to the displacement.

In some embodiments, in order to facilitate processing, the main electrode 2 is an overall cylindrical solid structure or a hollow structure made of conductive material, which is used to form a capacitor. The capacitors are drawn out from both ends of each main electrode 2 through metal leads. The present disclosure is also applicable to main electrodes 2 of other shapes, such as hexahedrons such as rectangular parallelepiped and cube. The structure and material of each main electrode 2 in all calculable capacitors are exactly the same, ensuring that the structure has symmetry, so that the capacitance can be calculated.

Further, referring to FIG. 4 and FIG. 5 , the computable capacitance structure provided by the embodiment of the present disclosure includes a total of four computable capacitors A, B, C, and D with the same structure. Now, the computable capacitor A is used as an example for explanation. It can be calculated that the capacitor A contains four main electrodes 21, 22, 23, and 24. The main electrodes 21 to 24 are all made of metal cylindrical electrodes. The main electrode 21 and the main electrode 23 are arranged diagonally, and the main electrode 22 and the main electrode 24 are arranged diagonally. Arranged diagonally and both grounded, the main electrode 21 and the main electrode 22 form a capacitor that can calculate the external output capacitance of the capacitor A. Its output capacitance is only related to the axial length of the capacitor (specifically, the shield electrode 1 is connected to the four main electrodes 21 The capacitance output by the capacitor A can be calculated by measuring the displacement of the shield electrode 1 along the movement in the space enclosed by the four main electrodes 21 to 24. In addition, the main electrode 21 and the main electrode 22 serve as the common main electrode of the two adjacent calculable capacitors A and B, and the main electrode 21 and the main electrode 24 serve as the common main electrode of the two adjacent calculable capacitors A and D. At the same time, The main electrode 21 also serves as the common main electrode of the four calculable capacitors A, B, C, and D, and serves as a pole of the entire calculable capacitance structure. The main electrode 23 of the calculable capacitors A, B, C, and D passes through The leads are connected in parallel as the other pole of the entire calculable capacitance structure, so that the calculable capacitors A, B, C, and D form a parallel structure (since the four calculable capacitors A, B, C, and D share part of the main electrode, it could have been There are a total of 9 main electrodes 2 and 4 shielding electrodes 1 in the calculated capacitor structure, and the 9 main electrodes 2 are arranged in a 3×3 array). After four calculable capacitors A, B, C, and D are connected in parallel, the external output capacitance is the sum of the capacitance values of the four calculable capacitors A, B, C, and D. Therefore, the measuring range of the overall structure is expanded to the original four times. At the same time, the capacitance changes of the four calculable capacitors do not interfere with each other. The movement of the shielding electrode in a certain calculable capacitor will only affect the capacitance value of the certain calculable capacitor and will not change the capacitance values of the other three calculable capacitors. Therefore, by separately controlling the movement of the shielding electrodes in the four calculable capacitors, the capacitance changes of each calculable capacitor can be independently adjusted to achieve high sensitivity within the full range.

In some embodiments, see FIG. 6 , the calculable capacitance structure provided by the embodiment of the present disclosure also includes an electrode sleeve 3 . In order to facilitate processing, the electrode sleeve 3 adopts an overall cylindrical solid structure. For electrode sleeves 3 of other shapes , such as the case of hexahedrons such as cuboids and cubes, the same is applicable to the present disclosure. A number of first through holes (the medium in the first through holes is air) and a number of second through holes are formed in the electrode sleeve 3 . Wherein, each shielding electrode 1 can move in a corresponding first through hole along the axial direction of the first through hole, thereby adjusting the capacitance of the calculable capacitor output and realizing a linear output of the capacitance with respect to the displacement. The inner diameter of the first through hole should be slightly larger than the outer diameter of the shield electrode 1, and the inner diameter of the first through hole should be as small as the outer diameter of the shield electrode 1 while ensuring that the movement of the shield electrode in the first through hole is not hindered. As close as possible to ensure that the air gap between the first through hole and the shield electrode 1 is as small as possible, thereby reducing the error in calculating the capacitance of the capacitor output. Each main electrode 2 is inserted into a corresponding second through hole, and each main electrode 2 remains motionless in the corresponding second through hole of the electrode cover 3 . The outer diameter of the electrode sleeve 3 should be enough to wrap all the main electrodes 2, thereby isolating the main electrodes 2 from the air. By setting the electrode cover 3, the dielectric constant between the main electrodes 2 can be increased (when the electrode cover is not set, the medium between the main electrodes 2 is air), thereby further expanding the range of the calculable capacitor. The multiple of the increase depends on Because of the dielectric constant of the electrode sleeve material, the material of the electrode sleeve 3 can be selected according to the range required for the calculated capacitor. Optionally, the electrode sleeve 3 is made of an insulating material or a semiconductor material with a dielectric constant greater than 10. into, such as ceramics, zirconia, lithium chloride.

In some embodiments, the shield electrode 1 adopts a slender cylindrical electrode. Without affecting the movement of the shield electrode 1, the distance between the shield electrode 1 and its surrounding main electrodes 2 should be as small as possible to reduce the calculated The error in the capacitance of the capacitor output.

In some embodiments, the shielding electrode 1 in each calculable capacitor includes a coarse-adjusting electrode 11 and a fine-adjusting electrode 12 respectively. The coarse-adjusting electrode 11 and the fine-adjusting electrode 12 can be independently connected to a corresponding first pass of the electrode sleeve 3 The inside of the hole moves along the axial direction of the first through hole, thereby adjusting the capacitance of the corresponding calculable capacitor output to achieve a linear output of the capacitance with respect to the displacement. Both the fine-adjusting electrode 12 and the coarse-adjusting electrode 11 are elongated cylindrical electrodes, and the dielectric constant of the fine-adjusting electrode 12 is smaller than the dielectric constant of the coarse-adjusting electrode 11. The outer diameters of the fine-adjusting electrode 12 and the coarse-adjusting electrode 11 are the same. Ensure that it can move freely in the first through hole and that the air gap is small enough. The present disclosure is also applicable to the fine-tuning electrode 12 and the coarse-tuning electrode 11 in other shapes, such as hexahedrons such as cuboids and cubes. Among them, the fine-adjusting electrode 12 has a solid structure or a hollow structure, is connected to the outside world through a gold wire lead, and is grounded to keep the coarse-adjusting electrode 11 fixed. The movement shields the main electrode 2, and at the same time, high-precision adjustment of the output capacitance of the calculable capacitor can be achieved. The coarse adjustment electrode 11 has a solid structure and keeps the fine adjustment electrode 12 fixed. By moving the coarse adjustment electrode 11 in the first through hole of the electrode sleeve 3, the output capacitance of the calculable capacitor can be greatly adjusted. Embodiments of the present disclosure provide fine-tuning electrodes and coarse-tuning electrodes for dielectric constants, thereby providing sensitivity for adjusting different capacitance values and having a wider applicable range. Specifically, under the condition that the fine-adjusting electrode is fixed, the output capacitance of the corresponding calculable capacitor can be greatly adjusted by moving the coarse-adjusting electrode within the electrode sleeve. Under the condition of fixing the coarse-adjusting electrode, through the movement of the fine-adjusting electrode in the electrode sleeve, high sensitivity of capacitance value adjustment can be achieved, maintaining the same accuracy as the existing design.

Further, the coarse adjustment electrode 11 enters and exits the first through hole of the electrode cover 3 from one end of the electrode cover 3, and the fine adjustment electrode 12 enters and exits the first through hole of the electrode cover 3 from the other end of the electrode cover 3, ensuring that the coarse adjustment electrode 11 and the fine-adjusting electrode 12 can work independently without interfering with each other.

Further, the fine-tuning electrode 12 is made of the same conductor material as the main electrode 2 , such as metal, or the fine-tuning electrode 12 and the main electrode 2 are made of different conductor materials. The coarse adjustment electrode 11 is made of the same insulating material or semiconductor material as the electrode sleeve 3, such as ceramic, so that the dielectric constant of the central space of the main electrode 2 is consistent, which facilitates capacitance calculation.

The working process of the coarse adjustment electrode 11 and the fine adjustment electrode 12 in the calculable capacitor A is described below:

The coarse adjustment electrode 11 can move up and down in the first through hole in the center of the electrode sleeve 3, and the fine adjustment electrode 12 can also move up and down in the first through hole. Keep the fine-adjusting electrode 12 stationary outside or inside the electrode sleeve 3. When the lower end surface of the coarse-adjusting electrode 11 moves up and down in the first through hole of the electrode sleeve 3, the capacitance output by the capacitor A and the coarse-adjusting electrode 1 can be calculated. The displacement has a linear relationship. In the same way, keep the coarse adjustment electrode 11 stationary outside or inside the electrode cover 3, and when the upper end surface of the fine adjustment electrode 3 moves up and down in the first through hole of the electrode cover 3, the capacitance and precision output of the capacitor A can be calculated. The displacement of the adjusting electrode 12 also has a linear relationship. Therefore, by fixing one of the coarse-adjusting electrode 11 and the fine-adjusting electrode 12 to be located outside or inside the electrode sleeve 3 , the other of the coarse-adjusting electrode 11 and the fine-adjusting electrode 12 is positioned in the first through hole of the electrode sleeve 3 By moving within, the linear change in capacitance of capacitor A output with displacement can be calculated. Due to the different dielectric constants of the media, the capacitance changes with the displacement of the coarse adjustment electrode 11 to a greater extent. For example, for the electrode sleeve 3 and the coarse-adjusting electrode 11 made of ceramics with a dielectric constant of 150, the relationship between the capacitance output by the capacitor A and the displacement of the coarse-adjusting electrode 11 can be calculated to be approximately 120 pF/m, which is 60 in the air. times, enabling a large range in a small volume. For the main electrode 2 and the fine-adjusting electrode 12 made of metal, it can be calculated that the relationship between the capacitance output by the capacitor A and the displacement of the fine-adjusting electrode 12 is about 1.95354902pF/m, which can ensure the high resolution of the capacitance. Therefore, the coarse adjustment electrode 11 can be used to realize coarse adjustment of the capacitance value, so that the overall volume of the capacitor can be reduced; and the fine adjustment electrode 12 can be used to realize fine adjustment of the capacitor, ensuring high sensitivity of the capacitor.

Keep the coarse adjustment electrode 11 completely located outside the electrode sleeve 3 and push the fine adjustment electrode 12 to gradually enter the first through hole of the electrode sleeve 3 until most of the first through hole is blocked by the fine adjustment electrode 12 ( At this time, the end of the fine-tuning electrode 12 entering the first through hole is at the maximum displacement), and most of the area of the main electrode 2 has been shielded by the fine-tuning electrode 12. At this time, it can be calculated that the capacitance of the capacitor A reaches the minimum value. For example, for a calculable capacitor A with a length of main electrode 2 of 103 mm and a length of electrode sleeve 3 of 80 mm, when the length of the finely adjusted electrode 12 entering the electrode sleeve 3 is 77 mm, the minimum value of the capacitance output by the capacitor A can be calculated is 0.08pF.

Keep the fine-adjusting electrode 12 completely outside the electrode cover 3 and push the coarse-adjusting electrode 11 to gradually enter the first through hole of the electrode cover 3 until the first through-hole is completely blocked by the coarse-adjusting electrode 11 (coarse adjustment at this time The end of the electrode 11 entering the first through hole is at the maximum displacement), and the main electrode 2 has no shielded area. At this time, it can be calculated that the capacitance output by the capacitor A reaches the maximum value. For example, for a calculable capacitor A with a length of main electrode 2 of 103 mm and a length of electrode sleeve 3 of 80 mm, when the length of the part where the coarse adjustment electrode 11 enters the electrode sleeve 3 is 80 mm, the maximum value of the capacitance output by the capacitor A can be calculated up to 11pF.

In some embodiments, the calculable capacitance structure provided by the embodiments of the present disclosure also includes a shielding shell (the shielding shell is not shown in the figure), and the electrode sleeve 3 and all the main electrodes 2 are accommodated in the shielding shell, To shield the influence of external interference on the capacitance accuracy.

In the description of this specification, content that is not described in detail is within the common knowledge of those skilled in the art. Reference is made to the terms “one embodiment”, “some embodiments”, “illustrative embodiments”, “examples” and “specific examples”. "," or "some examples," etc., means that a specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present disclosure have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purposes of the disclosure. The scope of the disclosure is defined by the claims and their equivalents.

Claims (8)

1. A calculable capacitance structure, characterized in that it includes a plurality of calculable capacitors connected in parallel and arranged symmetrically, and each of the calculable capacitors includes: Several main electrodes arranged parallel and symmetrically to each other, capacitors are drawn out from both ends of each main electrode through leads respectively, and a portion of the main electrode is shared between two adjacent calculable capacitors; and A shielding electrode that can move within a space formed by a plurality of main electrodes, thereby adjusting the capacitance output by the calculable capacitor and realizing a linear output of capacitance with respect to displacement; The calculable capacitance structure is provided with a total of 9 main electrodes and 4 shielding electrodes to form 4 calculable capacitors, and the 9 main electrodes are arranged in a 3×3 array. Two adjacent calculable capacitors share two main electrodes, and the main electrode located in the center is shared by four calculable capacitors for output capacitance, which is arranged diagonally to the main electrode located in the center. The main electrodes are connected in parallel, the remaining main electrodes are all grounded, and the structures and materials of the nine main electrodes are exactly the same. 2. The calculable capacitance structure according to claim 1, characterized in that the calculable capacitance structure further includes an electrode sleeve, and a plurality of first through holes and second through holes are respectively formed in the electrode sleeve, each of which is The shielding electrode can move in the corresponding first through hole along the axis of the first through hole, and each main electrode is inserted into the corresponding second through hole and remains relatively stationary with the electrode sleeve. . 3. The calculable capacitance structure according to claim 2, characterized in that each of the shielding electrodes respectively includes a first electrode and a second electrode, and the first electrode and the second electrode can be independently connected to each other. moves along the axis of one of the first through holes. 4. The calculable capacitance structure according to claim 3, wherein the dielectric constant of the first electrode is greater than the dielectric constant of the second electrode. 5. The calculable capacitance structure according to claim 4, wherein the second electrode and the electrode sleeve are kept relatively stationary by moving the first electrode in the first through hole. Coarse adjustment of the capacitance output by the calculable capacitor; when the second electrode is all located outside the electrode sleeve and the first electrode enters the first through hole to the maximum displacement, the calculable capacitor The capacitor output has the largest capacitance. 6. The calculable capacitance structure according to claim 4, wherein the first electrode and the electrode sleeve are kept relatively stationary by moving the second electrode in the first through hole. Fine adjustment of the capacitance output by the calculable capacitor; when the first electrode is all located outside the electrode sleeve, and the second electrode enters the first through hole to the maximum displacement, the calculable capacitor The capacitor output has the smallest capacitance. 7. The calculable capacitance structure according to claim 3, wherein the first electrode enters and exits the first through hole from one end of the electrode sleeve, and the second electrode enters and exits from the other end of the electrode sleeve. One end goes in and out of the first through hole. 8. The calculable capacitance structure according to claim 3, characterized in that the main electrode and the second electrode are made of the same or different conductor materials, and the electrode sleeve and the first electrode are made of the same conductor material. Made of insulating or semiconductor materials.