A ring-shaped ceramic capacitor with a hole drilled in the center.

Abstract

A ring-shaped ceramic capacitor with a central hole is provided. [Solution] An annular capacitor is formed by sintering a ceramic base and a ceramic reaction diaphragm together. Through holes are provided in the axial centers of both the ceramic base and the ceramic reaction diaphragm, providing assembly passages to the circuit elements to be combined. This facilitates the integration of the annular capacitor into the complex circuit of the temperature-pressure sensor. By simplifying the overall structure of the temperature-pressure sensor to include only the circuit and sealing structure, the temperature-pressure sensor is equipped with an automatically assembled structure, reducing production and assembly costs. The first and second annular circuits designed for the annular capacitor have higher initial values ​​and a wider range of change compared to a disc ceramic capacitor without a through hole in the center. This allows the annular capacitor to have a wider measurement range and finer pressure sensing grading, thereby improving the accuracy of pressure measurement.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and more particularly to an annular ceramic capacitor with a central perforation.

Background Art

[0002] A temperature-pressure sensor has a structure in which a temperature sensor portion, a pressure sensor portion, and a control processing portion arranged in sequence are provided in the axial direction. In order not to affect the simultaneous detection of pressure and temperature, the liquid to be detected is introduced into the reaction diaphragm of the pressure sensor portion, and while sensing the liquid pressure by the minute deformation of the reaction diaphragm, the detection passages of pressure and temperature are required to be independent so as not to affect the detection of the liquid temperature by the temperature sensor portion.

[0003] The conventional ceramic capacitor of the pressure sensor portion is a sealed circular electrostatic capacitive ceramic pressure sensor or a square electrostatic capacitive ceramic pressure sensor. As a result, the circuit of the temperature sensor portion needs to bypass the pressure sensor portion so as to be connected to the control processing portion located above, thereby increasing the complexity of the structure of the sensor.

[0004] As a current processing method, like the invention patent of Chinese Patent Application Publication No. 108414030, in order not to increase the volume of the temperature-pressure sensor and avoid affecting the performance of the ceramic capacitor, an eccentric capacitor opens holes around the capacitor to guide the lead wire of the temperature sensor portion from the side to the control processing portion. Since the lead wire to be guided is flexible, such a design form cannot realize the assembly manufacturing of the temperature-pressure sensor so as to be automatically assembled, and can only be assembled manually. Therefore, its manufacturing cost is relatively high, the production efficiency is lower than that of automatic assembly, and manual assembly does not have higher stability of the quality of the finished product than automatic assembly. Therefore, there is an urgent need for a temperature-pressure sensor that can facilitate automatic assembly and can improve the pressure measurement performance to a certain extent.

[0005] However, as an optimal processing method, a hole could be made in the center of the ceramic capacitor so that the temperature sensor leads could pass directly from the center of the ceramic capacitor to the control processing section without being wound around the sides. Such a structure would simplify the structure of the temperature-pressure sensor and enable automated assembly. However, with the current structure of ceramic capacitors, it is not possible to make a hole in the center, which would affect the pressure sensing performance of the ceramic capacitor.

[0006] As explained above, it has been found that conventional technology has at least the following problems. The problem is that the structure of conventional ceramic capacitors does not enable the automated assembly of temperature-pressure sensors. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The objective of the present invention is to provide a centrally perforated annular ceramic capacitor, thereby solving the problem that conventional ceramic capacitor structures cannot enable the automated assembly of temperature-pressure sensors without affecting the pressure sensing performance of the ceramic capacitor in the temperature-pressure sensor. [Means for solving the problem]

[0008] Many of the technical effects of the preferred technical proposal among the many technical proposals according to the present invention will be explained in detail below.

[0009] To solve the above problems, the present invention provides the following technical solutions. The present invention relates to a centrally perforated annular ceramic capacitor comprising a ceramic base and a ceramic reaction diaphragm, wherein through holes are provided in the axial centers of both the ceramic base and the ceramic reaction diaphragm, used to provide assembly passages to the circuit elements to be combined, a first annular circuit is printed on one surface of the ceramic base, the first annular circuit surrounds the outside of the through hole, a first insulating region is provided between the inner hole of the first annular circuit and the through hole, a second insulating region is provided between the outer ring of the first annular circuit and the outer edge of the ceramic base, a plurality of pins are provided on the other surface of the ceramic base, the plurality of pins are perforated to the surface on which the first annular circuit is provided, the lead wires of the first annular circuit are provided in the second insulating region and electrically connected to the pins, and a second annular circuit is printed on one surface of the ceramic reaction diaphragm, the ceramic A MIC reaction diaphragm is fitted with the ceramic base such that the second annular circuit faces the first annular circuit of the ceramic base, the leads of the second annular circuit of the ceramic reaction diaphragm are electrically connected to one of the pins on the ceramic base, the other side of the ceramic reaction diaphragm is used to acquire pressure and generate deformation by being subjected to impact from a medium to be measured, an insulating layer is applied to the surface of the first annular circuit, an insulating adhesive is applied to the first insulating region and the second insulating region, the insulating layer and the insulating adhesive are used to separate the ceramic reaction diaphragm from the ceramic base, and after the ceramic reaction diaphragm and the ceramic base are fitted together, an annular capacitor is formed by sintering, and the capacitance of the annular capacitor is 10 to 80 pF, providing a centrally perforated annular ceramic capacitor.

[0010] In one embodiment, the diameter of the through hole is 3.5 mm or less.

[0011] In one embodiment, the overlap error between the axis of the through hole, the axis of the ceramic base, and the axis of the ceramic reaction diaphragm is 3 mm or less.

[0012] In one embodiment, the thickness of the ceramic reaction diaphragm is 0.2 to 1.2 mm.

[0013] In one embodiment, when the ceramic reaction diaphragm is subjected to pressure, the change in the annular capacitor is 1 to 30 pF.

[0014] In one embodiment, the insulating adhesive material contains 60-80% glass powder.

[0015] In one embodiment, the insulating layer material contains 70-90% glass powder.

[0016] In one embodiment, the printing material for the first annular circuit and the second annular circuit is gold.

[0017] In one embodiment, the first annular circuit is composed of two annular electrodes, a first annular electrode and a second annular electrode, the second annular electrode surrounding the outside of the first annular electrode, the first annular electrode adjacent to the first insulating region, and a gap between the first annular electrode and the second annular electrode.

[0018] In one embodiment, the second annular circuit is composed of a third annular electrode, the third annular electrode covering the first annular electrode and the second annular electrode. [Effects of the Invention]

[0019] The beneficial effects of this invention are as follows: The annular ceramic capacitor with a central perforation designed by this invention offers the following improvements compared to conventional disc-shaped ceramic capacitors.

[0020] 1. By designing through holes in the axial centers of the ceramic base and ceramic reaction diaphragm, when applying a centrally perforated annular ceramic capacitor to an intelligent sensor such as a temperature-pressure sensor, an assembly passage is provided for the temperature probe lead wires to pass through, which is required to be mounted in front of the centrally perforated annular ceramic capacitor. This allows the centrally perforated annular ceramic capacitor to be easily integrated into the original complex circuit of the temperature-pressure sensor, simplifying the overall structure of the temperature-pressure sensor to include only the circuit and sealing structure. Furthermore, it improves the circuit assembly efficiency of the centrally perforated annular ceramic capacitor, temperature probe, and control processing unit, simplifying the assembly process and enabling automated assembly, directly improving assembly efficiency and further reducing assembly costs.

[0021] 2. In a disc-shaped ceramic capacitor without a through hole in the center, the reaction diaphragm has a circular pressure-receiving surface. Compared to an annular pressure-receiving surface, the axial stress on the circular pressure-receiving surface is greater. When deformed under pressure, the distance from the center of the circular pressure-receiving surface to the circumference is relatively long, resulting in a relatively long moment arm. The deformation in the central area of ​​the circular pressure-receiving surface is greater than at the edges of the circumference. After repeated high-intensity pressure shocks, the reaction diaphragm is prone to fatigue, which accelerates cracking due to aging.

[0022] In a centrally perforated annular ceramic capacitor, both the ceramic base and the ceramic reaction diaphragm have annular structures, and the electrodes printed on their surface also have annular structures. When pressure is applied, the pressure-receiving surface shape of the ceramic reaction diaphragm is also annular. The initial value of the annular capacitor is designed to be relatively large, and even a small change in the shape of the pressure-receiving ceramic reaction diaphragm can cause a relatively large change in the capacitance value of the annular capacitor. This results in relatively small deformation of the ceramic reaction diaphragm, thereby extending the lifespan of the diaphragm and giving the pressure sensor equipped with a centrally perforated annular ceramic capacitor better stability and reliability.

[0023] 3. The annular ceramic capacitor with a central perforation has a larger initial capacitance value and capacitance change amount compared to the disc-shaped ceramic capacitor without a central through-hole. As a result, the annular ceramic capacitor with a central perforation has a wider measurement range and finer scale, which means a wider pressure detection range and finer pressure detection grading. Consequently, the pressure measurement accuracy of the temperature-pressure sensor equipped with the annular ceramic capacitor with a central perforation is higher.

Brief Description of the Drawings

[0024] To more clearly explain the technical solution of the present invention, the drawings necessary for use in the following embodiments are briefly introduced below. Obviously, the drawings in the following description are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0025] [Figure 1] It is an axonometric projection view of the structure of the annular capacitor of the present invention. [Figure 2] It is a bottom view of the structure of the ceramic base of the present invention. [Figure 3] It is a plan view of the structure of the ceramic reaction diaphragm of the present invention. [Figure 4] It is a cross-sectional view of the structure of the annular capacitor of the present invention.

Modes for Carrying Out the Invention

[0026] Hereinafter, while referring to the drawings in the embodiments of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described.

[0027] Embodiments for carrying out the invention are provided, which include a centrally perforated annular ceramic capacitor. The annular capacitor is formed by sintering together a ceramic base and a ceramic reaction diaphragm. Through holes are provided in the axes of both the ceramic base and the ceramic reaction diaphragm, providing assembly passages to the circuit elements to be combined. This facilitates the integration of the annular capacitor into the complex circuit of a temperature-pressure sensor, simplifying the overall structure of the temperature-pressure sensor to include only the circuit and sealing structure. This allows the temperature-pressure sensor to have an automatically assembled structure, reducing production and assembly costs and effectively solving the problem that conventional ceramic capacitor structures cannot achieve automatic assembly of temperature-pressure sensors. The first and second annular circuits designed in the annular capacitor have a higher initial capacitance value and a wider capacitance change range compared to a disc-shaped ceramic capacitor without a central through hole. This allows the annular capacitor to have a wider measurement range and finer pressure sensing classification, thereby improving the accuracy of pressure measurement.

[0028] Furthermore, not all of the configurations shown in the following examples are necessarily essential as means of solving the invention described in the claims.

[0029] The first embodiment of a centrally perforated annular ceramic capacitor, as shown in Figures 1 to 4, includes a ceramic base 1 and a ceramic reaction diaphragm 2, both of which have through holes 3 at their axial centers, and are used to provide assembly passages to the circuit elements to be combined. A first annular circuit 11 is printed on one surface of the ceramic base 1, the first annular circuit 11 surrounds the outside of the through hole 3, a first insulating region 12 is provided between the inner hole of the first annular circuit 11 and the through hole 3, a second insulating region 13 is provided between the outer ring of the first annular circuit 11 and the outer edge of the ceramic base 1, and a plurality of pins 14 are provided on the other surface of the ceramic base 1, the plurality of pins 14 are perforated up to the surface on which the first annular circuit 11 is provided, and the lead wires of the first annular circuit 11 are provided in the second insulating region 13. Electrically connected, a second annular circuit 21 is printed on one side of the ceramic reaction diaphragm 2, the ceramic reaction diaphragm 2 is fitted with the ceramic base 1 such that the second annular circuit 21 faces the first annular circuit 11 of the ceramic base 1, the leads of the second annular circuit 21 of the ceramic reaction diaphragm 2 are electrically connected to one pin 14 on the ceramic base 1, the other side of the ceramic reaction diaphragm 2 is used to acquire pressure and generate deformation by being subjected to impact from the medium to be measured, an insulating layer 15 is applied to the surface of the first annular circuit 11, an insulating adhesive 16 is applied to the first insulating region 12 and the second insulating region 13, the insulating layer 15 and the insulating adhesive 16 are used to separate the ceramic reaction diaphragm 2 and the ceramic base 1, and after the ceramic reaction diaphragm 2 and the ceramic base 1 are fitted together, an annular capacitor is formed by sintering.

[0030] Here, the medium to be measured on the other side of the ceramic reaction diaphragm 2 can be a medium to which pressure is applied, such as a gas or a liquid.

[0031] The first annular circuit 11 is composed of two annular electrodes, a first annular electrode 111 and a second annular electrode 112. The second annular electrode 112 surrounds the outside of the first annular electrode 111, the first annular electrode 111 is adjacent to the first insulating region 12, and a gap is provided between the first annular electrode 111 and the second annular electrode 112.

[0032] The second annular circuit 21 is composed of one annular electrode which is the third annular electrode 211, and the third annular electrode 211 covers the first annular electrode 111 and the second annular electrode 112. Specifically, lead wires 4 are provided on the first annular electrode 111, the second annular electrode 112, and the third annular electrode 211. The second annular electrode 112 has a notch, and the lead wire of the first annular electrode 111 extends from the notch and is electrically connected to the first pin 14, and lead wires extend from both ends of the notch of the second annular electrode 112 and are electrically connected to the second pin 14. The lead wire of the third annular electrode 211 is electrically connected to the third pin 14.

[0033] Furthermore, the first annular electrode 111 has a larger area than the second annular electrode 112.

[0034] Specifically, the outer periphery of the ceramic base 1 and the ceramic reaction diaphragm 2 is circular. Therefore, the annular capacitor formed on the ceramic reaction diaphragm 2 and the ceramic base 1 is formed not only because the electrodes on the ceramic reaction diaphragm 2 and the ceramic base 1 are annular, but also because the outer shapes of the ceramic reaction diaphragm 2 and the ceramic base 1 are circular. By aligning the ceramic reaction diaphragm 2 and the ceramic base 1 in accordance with the central drilling, an annular capacitor is formed.

[0035] Furthermore, in disc-shaped ceramic capacitors without a through-hole in the center, the reaction diaphragm has a circular pressure-receiving surface. Compared to an annular pressure-receiving surface, the axial stress on the circular pressure-receiving surface is greater. When deformed under pressure, the distance from the center to the circumference of the circular pressure-receiving surface is relatively long, resulting in a relatively long moment arm. Consequently, the deformation in the central area of ​​the circular pressure-receiving surface is greater than at the circumferential edge. After repeated high-intensity pressure shocks, the reaction diaphragm is prone to fatigue, which accelerates cracking due to aging.

[0036] In a centrally perforated annular ceramic capacitor, both the ceramic base 1 and the ceramic reaction diaphragm 2 have annular structures, and the electrodes printed on their surfaces also have annular structures. When pressure is applied, the pressure-receiving surface shape of the ceramic reaction diaphragm 2 is also annular. The initial value of the annular capacitor is designed to be relatively large, and when pressure is applied, even a small change in the shape of the ceramic reaction diaphragm 2 can cause a relatively large change in the capacitance value of the annular capacitor. This results in relatively small deformation of the ceramic reaction diaphragm 2, thereby extending the service life of the diaphragm and giving the pressure sensor equipped with a centrally perforated annular ceramic capacitor better stability and reliability.

[0037] Furthermore, the centrally perforated annular ceramic capacitor is designed with a through-hole 3 in the axis of the ceramic base 1 and ceramic reaction diaphragm 2. This provides an assembly passage for the temperature probe's lead wires to pass through, which is required to be mounted in front of the centrally perforated annular ceramic capacitor when applied to an intelligent sensor such as a temperature-pressure sensor. This allows the centrally perforated annular ceramic capacitor to be easily integrated into the original complex circuit of the temperature-pressure sensor, simplifying the overall structure of the temperature-pressure sensor to include only the circuit and sealing structure. Moreover, it improves the circuit assembly efficiency of the centrally perforated annular ceramic capacitor, temperature probe, and control processing unit, simplifying the assembly process and enabling automated assembly, directly improving assembly efficiency and further reducing assembly costs.

[0038] Here, (1) the temperature-pressure sensor using a circular ceramic capacitor with a central perforation has a seal structure that reduces the number of components to one base and two seal rings, reduces the number of assembly parts, lowers material costs, reduces assembly processes, and lowers assembly costs.

[0039] (2) Due to the circuit structure, the temperature probe of conventional temperature-pressure sensors uses a flexible flat cable. The lead wire of the temperature probe, which is located on the axis of the temperature-pressure sensor, needs to be wound from the axis to the flat notch on the circumferential side of the disc-shaped ceramic capacitor during installation. The lead wire only reaches the circuit board of the control processing unit after passing through the notch, and the circuit is welded. Because the temperature probe uses a flexible flat cable, the assembly of this conventional temperature-pressure sensor can only be completed manually, and the welding of the flat cable can only be completed manually. As a result, assembly automation cannot be achieved, the assembly process increases, assembly efficiency decreases, and assembly costs rise in a straight line. On the other hand, the annular ceramic capacitor with a hole in the center When applied, the lead wires of the temperature probe of the temperature-pressure sensor can be replaced with pins. As a result, when the temperature probe is automatically grasped during automatic assembly, the pins pass directly through the through-hole 3 in the center of the centrally perforated annular ceramic capacitor and directly into the corresponding pinhole of the control processing unit. Furthermore, the pins of the centrally perforated annular ceramic capacitor are aligned with the corresponding pinholes of the control processing unit, and the temperature probe and the pins of the centrally perforated annular ceramic capacitor are welded to the circuit board of the control processing unit using automatic welding. This simplifies the assembly process, enables automatic welding of the temperature probe and the centrally perforated annular ceramic capacitor, directly improves assembly efficiency, and reduces assembly costs.

[0040] As one embodiment of this, The diameter of the through-hole 3 located in the center of the ceramic base 1 and the ceramic reaction diaphragm 2 is 3.5 mm or less.

[0041] Furthermore, the overlapping error between the axis of the through hole 3, the axis of the ceramic base 1, and the axis of the ceramic reaction diaphragm 2 is 3 mm or less.

[0042] The thickness of the ceramic reaction diaphragm 2 is 0.2 to 1.2 mm.

[0043] When applied, the centrally perforated ceramic reaction diaphragm 2 can be manufactured to a minimum thickness of 0.2 mm, further reducing the overall thickness of the annular capacitor. This, in turn, further reduces the overall height of the temperature-pressure sensor assembled with the annular capacitor, shrinking the sensor volume and further improving integration density. Further miniaturization of the temperature-pressure sensor means that the volume requirements of the mounting environment may be higher, resulting in lower application barriers and a wider range of applications for the temperature-pressure sensor.

[0044] Furthermore, the thinner ceramic reaction diaphragm 2 gives the annular condenser higher sensitivity, allowing it to detect liquids with smaller pressure changes, resulting in more precise pressure detection, an improved range of application, and usability in low-pressure situations.

[0045] Furthermore, regarding the change in capacitance of the above-mentioned annular capacitor, when the ceramic reaction diaphragm 2 is subjected to pressure, the change in capacitance of the annular capacitor is 1 to 30 pF.

[0046] The capacitance of the above-mentioned annular capacitor is 10 to 80 pF, meaning that the initial capacitance value of the annular capacitor during pressure measurement is 10 to 80 pF, and the range of the initial capacitance value is wider.

[0047] Comparison by test: Y1 is the annular capacitor of the present invention, and Y2 is a disc-shaped ceramic capacitor without a through hole in the center. [Table 1]

[0048] When applied, as can be seen from the comparative data from tests, annular ceramic capacitors with a central perforation have a higher initial capacitance value and a wider capacitance change range compared to disc-shaped ceramic capacitors without a central perforation. Consequently, annular ceramic capacitors with a central perforation have a wider measurement range and a finer scale, which means a wider pressure detection range and finer pressure detection grading. Thus, temperature-pressure sensors equipped with annular ceramic capacitors with a central perforation have higher pressure measurement accuracy.

[0049] Regarding the important components of the insulating adhesive 16 covering the first insulating region 12 and the second insulating region 13, the material of the insulating adhesive 16 contains 60-80% glass powder.

[0050] Regarding the important components of the transparent insulating layer 15 covering the first annular circuit 11, the material of the insulating layer 15 contains 70-90% glass powder.

[0051] Regarding the ten most important components of the first annular circuit 11 and the second annular circuit 21 described above, the printing material for the first annular circuit 11 and the second annular circuit 21 is gold.

[0052] When applied, the glass powder forms an insulating layer after sintering. The glass powder content determines the insulating performance and degree of the insulating layer, and different regions require different insulating performance. This alone allows for ultimate optimization of the capacitance and capacitance change of the annular capacitor.

[0053] Each of the technical features of the above embodiments can be combined in any way, and for the sake of brevity, not all possible combinations of each of the technical features in the above embodiments will be described.

[0054] (Note) (Note 1) A centrally perforated annular ceramic capacitor comprising a ceramic base and a ceramic reaction diaphragm, Through holes are provided in the axial centers of both the ceramic base and the ceramic reaction diaphragm, and are used to provide assembly passages for the circuit elements to be combined. A first annular circuit is printed on one surface of the ceramic base, the first annular circuit surrounds the outside of the through hole, a first insulating region is provided between the inner hole of the first annular circuit and the through hole, and a second insulating region is provided between the outer ring of the first annular circuit and the outer edge of the ceramic base. Multiple pins are provided on the other side of the ceramic base, and the multiple pins are drilled to the surface on which the first annular circuit is provided, and the lead wires of the first annular circuit are provided in the second insulating region and electrically connected to the pins. A second annular circuit is printed on one surface of the ceramic reaction diaphragm, the ceramic reaction diaphragm is fitted with the ceramic base such that the second annular circuit faces the first annular circuit of the ceramic base, and the leads of the second annular circuit of the ceramic reaction diaphragm are electrically connected to one of the pins on the ceramic base. The other side of the ceramic reaction diaphragm is used to acquire pressure and generate deformation by receiving an impact from the medium to be measured. An annular ceramic capacitor with a central hole, characterized in that an insulating layer is applied to the surface of the first annular circuit, an insulating adhesive is applied to the first insulating region and the second insulating region, the insulating layer and the insulating adhesive are used to separate the ceramic reaction diaphragm and the ceramic base, an annular capacitor is formed by sintering after the ceramic reaction diaphragm and the ceramic base are joined together, and the capacitance of the annular capacitor is 10 to 80 pf.

[0055] (Note 2) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the diameter of the through-hole is 3.5 mm or less.

[0056] (Note 3) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the overlapping error between the axis of the through hole, the axis of the ceramic base, and the axis of the ceramic reaction diaphragm is 3 mm or less.

[0057] (Note 4) The annular ceramic capacitor with a central hole, as described in Appendix 1, is characterized in that the thickness of the ceramic reaction diaphragm is 0.2 to 1.2 mm.

[0058] (Note 5) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that when the ceramic reaction diaphragm is subjected to pressure, the amount of change in the annular capacitor is 1 to 30 pF.

[0059] (Note 6) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the insulating adhesive material contains 60-80% glass powder.

[0060] (Note 7) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the insulating layer material contains 70-90% glass powder.

[0061] (Note 8) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the printing material for the first annular circuit and the second annular circuit is gold.

[0062] (Note 9) The annular ceramic capacitor with a central hole as described in Appendix 1, characterized in that the first annular circuit is composed of two annular electrodes, a first annular electrode and a second annular electrode, the second annular electrode surrounds the outside of the first annular electrode, the first annular electrode is adjacent to the first insulating region, and a gap is provided between the first annular electrode and the second annular electrode.

[0063] (Note 10) The annular ceramic capacitor with a central hole as described in Appendix 9, characterized in that the second annular circuit is composed of one annular electrode which is a third annular electrode, and the third annular electrode covers the first annular electrode and the second annular electrode. [Explanation of symbols]

[0064] 1...Ceramic base, 11...First annular circuit, 111...First annular electrode, 112...Second annular electrode, 12...First insulating region, 13...Second insulating region, 14...Pin, 15...Insulating layer, 16...Insulating adhesive, 2...Ceramic reaction diaphragm, 21...Second annular circuit, 211...Third annular electrode, 3...Through hole, 4...Lead wire.

Claims

1. A centrally perforated annular ceramic capacitor comprising a ceramic base and a ceramic reaction diaphragm, Through holes are provided in the axial centers of both the ceramic base and the ceramic reaction diaphragm, and are used to provide assembly passages for the circuit elements to be combined. A first annular circuit is printed on one surface of the ceramic base, the first annular circuit surrounds the outside of the through hole, a first insulating region is provided between the inner hole of the first annular circuit and the through hole, and a second insulating region is provided between the outer ring of the first annular circuit and the outer edge of the ceramic base. Multiple pins are provided on the other side of the ceramic base, and the multiple pins are drilled to the surface on which the first annular circuit is provided, and the lead wires of the first annular circuit are provided in the second insulating region and electrically connected to the pins. A second annular circuit is printed on one surface of the ceramic reaction diaphragm, the ceramic reaction diaphragm is fitted with the ceramic base such that the second annular circuit faces the first annular circuit of the ceramic base, and the leads of the second annular circuit of the ceramic reaction diaphragm are electrically connected to one of the pins on the ceramic base. The other side of the ceramic reaction diaphragm is used to acquire pressure and generate deformation by receiving an impact from the medium to be measured. An annular ceramic capacitor with a central hole, characterized in that an insulating layer is applied to the surface of the first annular circuit, an insulating adhesive is applied to the first insulating region and the second insulating region, the insulating layer and the insulating adhesive are used to separate the ceramic reaction diaphragm and the ceramic base, an annular capacitor is formed by sintering after the ceramic reaction diaphragm and the ceramic base are joined, and the capacitance of the annular capacitor is 10 to 80 pf.

2. The annular ceramic capacitor with a central hole according to claim 1, characterized in that the diameter of the through hole is 3.5 mm or less.

3. The annular ceramic capacitor with a central hole according to claim 1, characterized in that the overlap error between the axis of the through hole, the axis of the ceramic base, and the axis of the ceramic reaction diaphragm is 3 mm or less.

4. The annular ceramic capacitor with a central hole according to claim 1, characterized in that the thickness of the ceramic reaction diaphragm is 0.2 to 1.2 mm.

5. The annular ceramic capacitor with a central hole according to claim 1, characterized in that when the ceramic reaction diaphragm is subjected to pressure, the amount of change in the annular capacitor is 1 to 30 pf.

6. The annular ceramic capacitor with a central hole according to claim 1, characterized in that the insulating adhesive material contains 60 to 80% glass powder.

7. The annular ceramic capacitor with a central hole according to claim 1, characterized in that the insulating layer material contains 70 to 90% glass powder.

8. The centrally perforated annular ceramic capacitor according to claim 1, characterized in that the printing material for the first annular circuit and the second annular circuit is gold.

9. The first annular circuit is composed of two annular electrodes, a first annular electrode and a second annular electrode, the second annular electrode surrounding the outside of the first annular electrode, the first annular electrode adjacent to the first insulating region, and a gap provided between the first annular electrode and the second annular electrode, characterized in that a centrally perforated annular ceramic capacitor according to claim 1.

10. The annular ceramic capacitor with a central hole according to claim 9, characterized in that the second annular circuit is composed of a single annular electrode which is a third annular electrode, and the third annular electrode covers the first annular electrode and the second annular electrode.

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