A center-perforated ring-shaped ceramic capacitor

Abstract

The invention discloses a center-perforated annular ceramic capacitor, which relates to the technical field of sensors. The annular capacitor is formed by sintering a ceramic base and a ceramic reaction diaphragm. The axes of the ceramic base and the ceramic reaction diaphragm are both provided with through holes, which provide assembly paths for circuit elements to be combined, so that the annular capacitor can be more conveniently integrated into the complex circuit of a temperature-pressure sensor, and the overall structure of the temperature-pressure sensor including the circuit and the sealing structure is simplified, so that the temperature-pressure sensor has an automatic assembly structure, and the production and assembly cost is reduced; the first annular circuit and the second annular circuit of the annular capacitor design have a higher initial value and a wider variation than a circular ceramic capacitor without a center through hole, so that the annular capacitor has a wider range and a finer pressure perception classification, thereby improving the accuracy of pressure measurement.

Description

Technical Field

[0001] The invention relates to the technical field of sensors, in particular to a central-perforated annular ceramic capacitor. Background Art

[0002] The structure of the temperature-pressure sensor is as follows: a temperature sensing part, a pressure sensing part and a control processing part are arranged in sequence in the axial direction; in order not to affect the simultaneous detection of pressure and temperature, the detected liquid needs to be introduced into the reaction diaphragm of the pressure sensing part, so that the liquid pressure can be sensed through the slight deformation of the reaction diaphragm, but it cannot affect the detection of the liquid temperature by the temperature sensing part, and the pressure and temperature detection channels are separated.

[0003] The existing ceramic capacitor of the pressure sensing part is a sealed circular ceramic capacitor pressure sensor or a square ceramic capacitor pressure sensor, which requires the circuit of the temperature sensing part to bypass the pressure sensing part in order to connect to the control processing part located above, thereby increasing the structural complexity of the sensor.

[0004] The current processing method is, for example, invention patent: CN108414030B. In order not to increase the volume of the temperature-pressure sensor and to avoid affecting the performance of the ceramic capacitor, an eccentric capacitor is used to drill holes around the capacitor to guide the wire of the temperature sensor part from the side to the control processing part. Because the guided wire is soft, this design method makes it impossible to realize the assembly and manufacturing of the temperature-pressure sensor by automated assembly, and it can only be assembled manually, which makes its manufacturing cost higher and the production efficiency lower than that of automated assembly. At the same time, the stability of the quality of the finished product of manual assembly is not as high as that of automated assembly. Therefore, there is an urgent need for a temperature-pressure sensor structure that can facilitate automated assembly and can also improve the pressure measurement performance of the temperature-pressure sensor to a certain extent.

[0005] However, the best solution is to drill a hole in the center of the ceramic capacitor so that the wires of the temperature sensor do not need to be wrapped around the side, but can directly pass through the center of the ceramic capacitor to the control processing part. This structure simplifies the structure of the temperature-pressure sensor and makes automated assembly possible; but with the current structure of ceramic capacitors, it is impossible to drill a hole in the center, which will affect the pressure sensing performance of the ceramic capacitor.

[0006] In summary, it is found that the prior art has at least the following technical problems:

[0007] The structure of existing ceramic capacitors cannot realize the automated assembly of temperature-pressure sensors. Summary of the invention

[0008] The purpose of the present invention is to provide a center-perforated annular ceramic capacitor, which solves the problem that the structure of the existing ceramic capacitor cannot realize the automatic assembly of the temperature-pressure sensor without affecting the pressure sensing performance of the ceramic capacitor in the temperature-pressure sensor.

[0009] The various technical effects that can be produced by the preferred technical solutions among the various technical solutions provided by the present invention are described in detail below.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] The present invention provides a center-perforated annular ceramic capacitor, comprising a ceramic base and a ceramic reaction diaphragm, wherein the axes of the ceramic base and the ceramic reaction diaphragm are both provided with through holes for providing assembly paths for circuit elements to be assembled; a first annular circuit is printed on one side of the ceramic base; the first annular circuit is sleeved outside the through hole, a first insulating area is provided between the inner hole of the first annular circuit and the through hole, and a second insulating area 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 side of the ceramic base, and a plurality of the pins are perforated to the surface provided with the first annular circuit; the leads of the first annular circuit are provided in the second insulating area and are electrically connected to the pins; A second annular circuit is printed on one side of the diaphragm; the ceramic reaction diaphragm is merged with the first annular circuit of the ceramic base with the second annular circuit, and the lead of the second annular circuit of the ceramic reaction diaphragm is electrically connected to one of the pins of the ceramic base; the other side of the ceramic reaction diaphragm is used to receive the impact of the medium to be measured, so as to obtain pressure and generate deformation; an insulating layer is coated on the surface of the first annular circuit; the first insulating area and the second insulating area are coated with insulating glue; the insulating layer and the insulating glue are used to separate the ceramic reaction diaphragm from the ceramic base; the ceramic reaction diaphragm and the ceramic base are merged and sintered to form an annular capacitor; the capacitance of the annular capacitor is 10-80pf.

[0012] In one embodiment, the diameter of the through hole does not exceed 3.5 mm.

[0013] In one of the embodiments, the coincidence error between the axis of the through hole and the axis of the ceramic base and the axis of the ceramic reaction membrane does not exceed 3 mm.

[0014] In one embodiment, the thickness of the ceramic reaction membrane is 0.2-1.2 mm.

[0015] In one of the embodiments, after the ceramic reaction diaphragm is subjected to pressure, the change in the annular capacitance is 1-30 pf.

[0016] In one of the embodiments, the insulating adhesive material contains 60-80% glass powder.

[0017] In one embodiment, the material of the insulating layer contains 70-90% glass powder.

[0018] In one embodiment, the printing material of the first ring circuit and the second ring circuit is gold.

[0019] In one embodiment, the first annular circuit is composed of two annular electrodes, namely a first annular electrode and a second annular electrode; the second annular electrode is sleeved outside the first annular electrode, and the first annular electrode is adjacent to the first insulating area; and a gap is provided between the first annular electrode and the second annular electrode.

[0020] In one embodiment, the second annular circuit is composed of an annular electrode, which is a third annular electrode; the third annular electrode covers the first annular electrode and the second annular electrode.

[0021] The beneficial effects of the present invention are as follows:

[0022] The center-perforated annular ceramic capacitor designed in the present invention has the following improvements compared to the existing disc-shaped ceramic capacitors: 1. A through hole is designed at the axis of the ceramic base and the ceramic reaction diaphragm, so that when the center-perforated annular ceramic capacitor is used in a comprehensive sensor such as a temperature-pressure sensor, an assembly channel is provided for a temperature probe that needs to be installed in front of the center-perforated annular ceramic capacitor, through which the wire of the temperature probe can pass, so that the center-perforated annular ceramic capacitor can be more conveniently integrated into the original complex circuit of the temperature-pressure sensor, simplifying the overall structure of the temperature-pressure sensor including the circuit and the sealing structure, and also improving the circuit assembly efficiency of the center-perforated annular ceramic capacitor, the temperature probe and the control processing part, achieving simplification of the assembly process, and also realizing automatic assembly, directly further improving the assembly efficiency and reducing more assembly costs.

[0023] 2. The reaction diaphragm pressure surface of the disc-shaped ceramic capacitor with no through hole in the center is circular. Compared with the annular pressure surface, the axial stress of the circular pressure surface is larger. When it is compressed and deformed, the distance from the center to the circumference of the circular pressure surface is longer, the force arm is longer, and the deformation of the center range of the circular pressure surface is larger than that of the circumference. After repeated high-intensity pressure shocks, the reaction diaphragm is prone to fatigue, thereby accelerating aging and cracking.

[0024] The ceramic base and ceramic reaction diaphragm of the center-perforated annular ceramic capacitor are both annular in structure, and the electrodes printed on its surface are also annular in structure. When under pressure, the pressure surface of the ceramic reaction diaphragm is also annular in shape. The initial value of the annular capacitance is designed to be relatively large. The compressed ceramic reaction diaphragm only needs a slight change in shape to cause a large change in capacitance value. The deformation of the ceramic reaction diaphragm is relatively small, thereby increasing the service life of the diaphragm and making the pressure sensor equipped with the center-perforated annular ceramic capacitor have better stability and reliability.

[0025] 3. Compared with the disc-shaped ceramic capacitor without a through hole in the center, the center-perforated annular ceramic capacitor has a higher initial capacitance value and capacitance change, which makes the center-perforated annular ceramic capacitor have a wider range and a finer scale, which means that the pressure detection range is larger and the pressure detection classification is finer, so that the pressure measurement accuracy of the temperature-pressure sensor equipped with the center-perforated annular ceramic capacitor is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the isometric structure of the annular capacitor of the present invention;

[0028] Figure 2 1 is a schematic diagram of the bottom-up structure of the ceramic base of the present invention;

[0029] Figure 3 It is a schematic diagram of the top view of the structure of the ceramic reaction diaphragm of the present invention;

[0030] Figure 4 It is a schematic diagram of the cross-sectional structure of the annular capacitor of the present invention.

[0031] The reference numerals are as follows:

[0032] 1. Ceramic base; 11. First annular circuit; 111. First annular electrode; 112. Second annular electrode; 12. First insulating area; 13. Second insulating area; 14. Pin; 15. Insulating layer; 16. Insulating glue;

[0033] 2. Ceramic reaction diaphragm; 21. Second annular circuit; 211. Third annular electrode;

[0034] 3. Through hole;

[0035] 4. Lead. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] A specific embodiment provides a center-perforated annular ceramic capacitor, which is formed by sintering a ceramic base and a ceramic reaction diaphragm together to form an annular capacitor. The axis of the ceramic base and the ceramic reaction diaphragm are both provided with through holes, providing assembly paths for the circuit elements to be combined, so that the annular capacitor can be more conveniently integrated into the complex circuit of the temperature-pressure sensor, simplifying the overall structure of the temperature-pressure sensor including the circuit and the sealing structure, so that the temperature-pressure sensor has an automated assembly structure, reducing the production and assembly costs; effectively solving the problem that the structure of the existing ceramic capacitor cannot realize the automated assembly of the temperature-pressure sensor. The first annular circuit and the second annular circuit of the annular capacitor design have a higher initial capacitance value and a wider capacitance variation than the disc-shaped ceramic capacitor without a through hole in the center, so that the annular capacitor has a wider range and a finer pressure perception grading, thereby improving the accuracy of pressure measurement.

[0038] In addition, all the contents of the configurations shown in the following embodiments are not necessarily limited to the solutions of the invention described in the claims.

[0039] The first embodiment of a center-perforated annular ceramic capacitor is as follows Figures 1 to 4 As shown, it includes a ceramic base 1 and a ceramic reaction diaphragm 2, and the axes of the ceramic base 1 and the ceramic reaction diaphragm 2 are both provided with through holes 3, which are used to provide assembly paths for circuit elements to be assembled; a first ring circuit 11 is printed on one side of the ceramic base 1; the first ring circuit 11 is sleeved outside the through hole 3, a first insulating area 12 is provided between the inner hole of the first ring circuit 11 and the through hole 3, and a second insulating area 13 is provided between the outer circle of the first ring circuit 11 and the outer edge of the ceramic base 1; a plurality of pins 14 are provided on the other side of the ceramic base 1, and the plurality of pins 14 are perforated to the surface provided with the first ring circuit 11; the leads of the first ring circuit 11 are provided in the second insulating area 13 and are electrically connected to the pins 14; A second ring circuit 21 is printed on one side of the reaction diaphragm 2; the ceramic reaction diaphragm 2 is merged with the first ring circuit 11 of the ceramic base 1 with the second ring circuit 21, and the lead of the second ring circuit 21 of the ceramic reaction diaphragm 2 is electrically connected to one of the pins 14 of the ceramic base 1; the other side of the ceramic reaction diaphragm 2 is used to receive the impact of the medium to be measured, so as to obtain pressure and generate deformation; an insulating layer 15 is coated on the surface of the first ring circuit 11; the first insulating area 12 and the second insulating area 13 are coated with insulating glue 16; the insulating layer 15 and the insulating glue 16 are used to separate the ceramic reaction diaphragm 2 from the ceramic base 1; the ceramic reaction diaphragm 2 is merged with the ceramic base 1 and then sintered to form a ring capacitor.

[0040] The medium to be measured received by the other side of the ceramic reaction diaphragm 2 may be a medium capable of imparting pressure, such as gas or liquid.

[0041] The first annular circuit 11 is composed of two annular electrodes, including a first annular electrode 111 and a second annular electrode 112 ; the second annular electrode 112 is sleeved outside the first annular electrode 111 , and the first annular electrode 111 is adjacent to the first insulating region 12 ; a gap is provided between the first annular electrode 111 and the second annular electrode 112 .

[0042] The second annular circuit 21 is composed of an annular electrode, which is a third annular electrode 211; the third annular electrode 211 covers the first annular electrode 111 and the second annular electrode 112;

[0043] Specifically, the first annular electrode 111, the second annular electrode 112 and the third annular electrode 211 are all provided with a lead wire 4;

[0044] The second annular electrode 112 has a notch, the lead of the first annular electrode 111 extends from the notch and is electrically connected to the first pin 14, and leads extend from both ends of the notch of the second annular electrode 112 and are electrically connected to the second pin 14. The lead of the third annular electrode 211 is electrically connected to the third pin 14.

[0045] Furthermore, the area of ​​the first annular electrode 111 is larger than that of the second annular electrode 112 .

[0046] Specifically, the outer periphery of the ceramic base 1 and the ceramic reaction diaphragm 2 is circular. Therefore, the ceramic reaction diaphragm 2 and the ceramic base 1 form an annular capacitor, and the electrodes on the ceramic reaction diaphragm 2 and the ceramic base 1 are not only annular, but also the outer shapes of the ceramic reaction diaphragm 2 and the ceramic base 1 are circular, and the central perforation is superimposed, and the ceramic reaction diaphragm 2 and the ceramic base 1 are combined to form an annular capacitor.

[0047] Furthermore, the reaction diaphragm pressure surface of the disc-shaped ceramic capacitor with no through hole in the center is circular. Compared with the annular pressure surface, the axial stress of the circular pressure surface is larger. When it is compressed and deformed, the distance from the center to the circumference of the circular pressure surface is longer, the force arm is longer, and the deformation of the central range of the circular pressure surface is larger than that of the circumferential edge. After repeated high-intensity pressure shocks, the reaction diaphragm is prone to fatigue, thereby accelerating aging and cracking.

[0048] The ceramic base 1 and the ceramic reaction diaphragm 2 of the center-perforated annular ceramic capacitor are both annular in structure, and the electrodes printed on the surface are also annular in structure. When under pressure, the pressure surface of the ceramic reaction diaphragm 2 is also annular in shape. The initial value of the annular capacitance is designed to be relatively large. The compressed ceramic reaction diaphragm 2 only needs a slight change in shape to cause a large change in capacitance value of the annular capacitor. The deformation of the ceramic reaction diaphragm 2 is relatively small, thereby increasing the service life of the diaphragm, and making the pressure sensor equipped with the center-perforated annular ceramic capacitor have better stability and reliability.

[0049] Furthermore, the center-perforated annular ceramic capacitor is designed with a through hole 3 on the axis of the ceramic base 1 and the ceramic reaction diaphragm 2. Therefore, when the center-perforated annular ceramic capacitor is used in a comprehensive sensor such as a temperature-pressure sensor, a temperature probe that needs to be installed in front of the center-perforated annular ceramic capacitor is provided with an assembly channel through which the wire of the temperature probe can pass. This makes it easier to integrate the center-perforated annular ceramic capacitor into the original complex circuit of the temperature-pressure sensor, simplifies and improves the overall structure of the temperature-pressure sensor including the circuit and the sealing structure, and also improves the circuit assembly efficiency of the center-perforated annular ceramic capacitor, the temperature probe and the control processing part, thereby simplifying the assembly process and realizing automated assembly, which directly further improves the assembly efficiency and reduces more assembly costs.

[0050] Among them: (1) By using a temperature-pressure sensor with a center-perforated annular ceramic capacitor, compared with the previous generation product using a disc-shaped ceramic capacitor without a center through-hole, namely, invention patent: CN108414030B, the components on the sealing structure are reduced by one base and two sealing rings, the number of assembled parts is reduced, the material cost is reduced, the assembly process is reduced, and the assembly cost is also reduced.

[0051] (2) In terms of circuit structure, the temperature probe of the previous generation of temperature-pressure sensors uses a soft flat cable. The wire of the temperature probe located at the axis of the temperature-pressure sensor needs to be wound from the axis to the flattened notch on the circumferential side of the disc-shaped ceramic capacitor during installation. The wire passes through the notch to reach the circuit board of the control processing part for circuit welding. Since the temperature probe uses a soft flat cable, the assembly of this generation of temperature-pressure sensor products can only be completed manually, and the welding of the flat cable can only be completed manually, resulting in the inability to realize automated assembly, increasing the number of assembly processes, reducing assembly efficiency, and sharply increasing assembly costs. However, the use of a center-perforated annular ceramic capacitor, the temperature-pressure sensor can only be assembled manually. The wires of the temperature probe of the temperature-pressure sensor can be replaced by pins, so that during the automatic assembly, after the temperature probe is automatically clamped, the pins can directly pass through the through hole 3 in the center of the center-perforated annular ceramic capacitor to reach the corresponding pinhole of the control processing part; then the pins of the center-perforated annular ceramic capacitor are also aligned with the corresponding pinholes of the control processing part, and the pins of the temperature probe and the center-perforated annular ceramic capacitor are directly welded to the circuit board of the control processing part using automatic welding, thereby simplifying the assembly process and realizing the automatic welding of the temperature probe and the center-perforated annular ceramic capacitor, directly improving the assembly efficiency and reducing the assembly cost at the same time.

[0052] As one optional implementation,

[0053] Regarding the diameter of the through hole 3 in the center of the ceramic base 1 and the ceramic reaction membrane 2, the diameter of the through hole 3 does not exceed 3.5 mm.

[0054] Furthermore, the coincidence error between the axis of the through hole 3 and the axis of the ceramic base 1 and the axis of the ceramic reaction membrane 2 does not exceed 3 mm.

[0055] Regarding the thickness of the ceramic reaction diaphragm 2, the thickness of the ceramic reaction diaphragm 2 is 0.2-1.2 mm.

[0056] When applied, the ceramic reaction diaphragm 2 with a central perforation can be made as thin as 0.2 mm, making the overall thickness of the annular capacitor smaller, thereby further reducing the overall height of the temperature-pressure sensor equipped with the annular capacitor, reducing the size of the sensor, and further improving the integration; a smaller temperature-pressure sensor means that the volume requirement for its installation scenario can be higher, the application barrier of the temperature-pressure sensor is smaller, and the application range is wider.

[0057] The thinner ceramic reaction diaphragm 2 makes the annular capacitor have higher sensitivity, which can detect liquids with smaller pressure changes, and the pressure detection is more precise. The application scope is further improved and can be used in micro-pressure scenarios.

[0058] Furthermore, regarding the capacitance variation of the annular capacitor, after the ceramic reaction diaphragm 2 is subjected to pressure, the capacitance variation of the annular capacitor is 1-30 pf.

[0059] The capacitance of the annular capacitor is 10-80 pf; that is, the initial capacitance value of the annular capacitor during pressure measurement is 10-80 pf, and the range of the initial capacitance value is wider.

[0060] Through testing and comparison: Y1 is the annular capacitor of the present invention, and Y2 is a disc-shaped ceramic capacitor without a through hole in the center;

[0061]

[0062] During application, it can be concluded through test comparison data that the center-perforated annular ceramic capacitor has a higher initial capacitance value and a wider capacitance variation than the disc-shaped ceramic capacitor without a through hole in the center, which makes the center-perforated annular ceramic capacitor have a wider range and a finer scale, which means that the pressure detection range is larger and the pressure detection classification is finer, so that the pressure measurement accuracy of the temperature-pressure sensor equipped with the center-perforated annular ceramic capacitor is higher.

[0063] Regarding the key components of the insulating glue 16 covering the first insulating region 12 and the second insulating region 13, the material of the insulating glue 16 contains 60-80% of glass powder.

[0064] Regarding the key component of the transparent insulating glue 15 covering the first ring circuit 11, the material of the insulating layer 15 contains 70-90% glass powder.

[0065] Regarding the key components of the first ring circuit 11 and the second ring circuit 21, the printing material of the first ring circuit 11 and the second ring circuit 21 is gold.

[0066] When applied, the glass powder will form an insulating layer after sintering, and the content of the glass powder will determine the insulating performance and degree of insulation of the insulating layer. Different areas require different insulating properties to optimize the capacitance and capacitance change of the ring capacitor to the extreme.

[0067] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A center-perforated annular ceramic capacitor, characterized in that: It comprises a ceramic base and a ceramic reaction diaphragm, wherein the axes of the ceramic base and the ceramic reaction diaphragm are both provided with through holes for providing assembly paths for circuit elements to be assembled; A first annular circuit is printed on one side of the ceramic base; the first annular circuit is sleeved outside the through hole, a first insulating area is provided between the inner hole of the first annular circuit and the through hole, and a second insulating area 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 side of the ceramic base, and the plurality of pins are penetrated to the surface provided with the first ring circuit; the leads of the first ring circuit are provided in the second insulating area and are electrically connected to the pins; A second annular circuit is printed on one surface of the ceramic reaction diaphragm; the ceramic reaction diaphragm is merged with the first annular circuit of the ceramic base with the second annular circuit facing the ceramic base, and the lead of the second annular circuit of the ceramic reaction diaphragm is electrically connected to one of the pins of the ceramic base; The other side of the ceramic reaction diaphragm is used to receive the impact of the medium to be measured, thereby obtaining pressure to generate deformation; An insulating layer is coated on the surface of the first ring circuit; the first insulating area and the second insulating area are coated with insulating glue; the insulating layer and the insulating glue are used to separate the ceramic reaction diaphragm from the ceramic base; the ceramic reaction diaphragm and the ceramic base are combined and sintered to form a ring capacitor; the capacitance of the ring capacitor is 10-80pf.

2. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The diameter of the through hole does not exceed 3.5 mm.

3. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The coincidence error between the axis of the through hole and the axis of the ceramic base and the axis of the ceramic reaction membrane does not exceed 3 mm.

4. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The thickness of the ceramic reaction membrane is 0.2-1.2 mm.

5. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: After the ceramic reaction diaphragm is subjected to pressure, the change amount of the annular capacitance is 1-30pf.

6. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The insulating adhesive material contains 60-80% glass powder.

7. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The material of the insulating layer contains 70-90% glass powder.

8. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The printing material of the first ring circuit and the second ring circuit is gold.

9. The center-perforated annular ceramic capacitor according to claim 1, characterized in that: The first annular circuit is composed of two annular electrodes, namely a first annular electrode and a second annular electrode; the second annular electrode is sleeved outside the first annular electrode, and the first annular electrode is adjacent to the first insulating area; A gap is provided between the first annular electrode and the second annular electrode.

10. The center-through-hole annular ceramic capacitor according to claim 9, characterized in that: The second annular circuit is composed of an annular electrode, which is the third annular electrode; The third annular electrode covers the first annular electrode and the second annular electrode.

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