Middle-high voltage ceramic dielectric capacitor with shielding electrode

Abstract

The utility model discloses a medium-high voltage ceramic dielectric capacitor with shielding electrodes, which relates to the field of capacitor structures and comprises an effective electric layer, and a first shielding electric layer and a second shielding electric layer are respectively arranged at two axial ends of the effective electric layer. The effective electric layer comprises a plurality of staggered and stacked effective units, each effective unit comprises a first effective electrode, a second effective electrode and a first ceramic dielectric layer, and the length of the first effective electrode is larger than that of the second effective electrode; each of the first shielding electric layer and the second shielding electric layer comprises at least one shielding unit, and each shielding unit comprises a first shielding electrode, a second shielding electrode and a second ceramic dielectric layer. According to the utility model, the first shielding electric layer and the second shielding electric layer are arranged to shield the two sides of the effective electric layer, and the electrode structures of the effective electric layer and the shielding electric layers are limited, so that the purpose of meeting the requirements of high power, high voltage bypass and coupling circuits under the condition that the volume of the capacitor is not enlarged is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to capacitor structure field, concretely relates to a middle and high voltage porcelain dielectric capacitor with shielding electrode. BACKGROUND

[0002] The middle and high voltage multilayer porcelain dielectric capacitor product is widely used in military and aerospace, power electronics, high voltage power supply, automobile electronics, communication equipment and the fields, especially in those extremely high system of capacitance stability, reliability requirement, acts power filter, resonance, bypass and low frequency coupling etc. The traditional PME middle and high voltage product, its inner electrode adopts Pd / Ag, and the cost is higher, and the volume ratio is small, and with the product stack layer number increases its structure stability is worse, is difficult to satisfy the demand of large capacity.

[0003] Therefore, the capacitor with the electrode prepared from the base metal is urgently needed, which can ensure small volume of the capacitor and also ensure that it is applicable to high-power, high-voltage bypass and coupling circuits, and can continuously work under high-voltage impact. SUMMARY

[0004] The utility model discloses a kind of middle and high voltage porcelain dielectric capacitor with shielding electrode, the capacitor is shielded to the two sides of effective electric layer by setting first shielding electric layer and second shielding electric layer, and limit the electrode structure of effective electric layer and shielding electric layer, to solve the problem that in prior art, in the case of small volume of capacitor, it is difficult to meet the requirement of high-power, high-voltage bypass and coupling circuit.

[0005] The utility model embodiment realizes by the following technical scheme: the utility model embodiment provides a kind of middle and high voltage porcelain dielectric capacitor with shielding electrode, including effective electric layer, the axial two ends of effective electric layer are respectively provided with first shielding electric layer and second shielding electric layer;

[0006] Effective electric layer includes a plurality of staggered effective units, and a single effective unit includes a first effective electrode, a second effective electrode and a first ceramic dielectric layer, the first effective electrode and the second effective electrode are respectively arranged on the transverse two sides of the first ceramic dielectric layer, and the length of the first effective electrode is greater than the length of the second effective electrode;

[0007] First shielding electric layer and second shielding electric layer both include at least one shielding unit, and the shielding unit includes a first shielding electrode, a second shielding electrode and a second ceramic dielectric layer, the first shielding electrode and the second shielding electrode are respectively arranged on the transverse two sides of the second ceramic dielectric layer, and are arranged in axial symmetry along the axial direction.

[0008] Preferably, the first shielding electric layer includes a plurality of shielding units, and the plurality of shielding units are arranged in overlap.

[0009] The second shielding electric layer comprises a plurality of shielding units, and the plurality of shielding units are arranged in an overlapping manner.

[0010] Preferably, the length of the first shielding electrode is greater than the length of the second effective electrode.

[0011] Preferably, the width of the first shielding electrode is greater than the width of the first effective electrode and the second effective electrode, and a line connecting the center of the outer side line of the first shielding electrode with the center of the outer side line of the first effective electrode is perpendicular to the first ceramic dielectric layer and the second ceramic dielectric layer.

[0012] Preferably, the width of the first shielding electrode is greater than the width of the first effective electrode and the second effective electrode, and a line connecting the center of the outer side line of the first shielding electrode with the center of the outer side line of the first effective electrode is perpendicular to the first ceramic dielectric layer and the second ceramic dielectric layer.

[0013] Preferably, the electrode thicknesses of the first shielding electrode, the second shielding electrode, the first effective electrode and the second effective electrode are equal.

[0014] Preferably, the first shielding electrode, the second shielding electrode, the first effective electrode and the second effective electrode are all in a quadrilateral structure, and four top corners are all arranged in a round corner manner.

[0015] Preferably, the radius of the round corner is greater than or equal to twice the electrode thickness.

[0016] Preferably, the thicknesses of each first ceramic dielectric layer are equal, and the thicknesses of each second ceramic dielectric layer are equal.

[0017] Preferably, the thickness of the single first ceramic dielectric layer is equal to the thickness of the single second ceramic dielectric layer.

[0018] Preferably, the first shielding electrode, the second shielding electrode, the first effective electrode and the second effective electrode are all made of Ni.

[0019] Compared with the prior art, the embodiments of the utility model have the following advantages and beneficial effects:

[0020] 1. The high-voltage ceramic capacitor with shielding electrodes provided by the embodiments of the utility model can withstand higher voltage under small size through the setting and structure limitation of the shielding electrodes, and meets the requirements of high-power, high-voltage bypass and coupling circuit. The shielding electric layer shields the two sides of the effective electric layer, thereby reducing the unevenness of the edge electric field, improving the voltage resistance performance of the capacitor, and reducing the risk of corona discharge. The effective electric layer is located between the two shielding electric layers, and the "sandwich" structure can maximize the shielding effect. The electrode structure of the effective electric layer is limited to ensure that the electric field is mainly distributed in the effective electric layer, rather than diffusing to the edge, thereby reducing the edge effect and leakage current.

[0021] 2、The length of the first shielding electrode is greater than the length of the second effective electrode, and the width of the first shielding electrode is greater than the width of the effective electrode, so that the shielding electrode can more effectively cover and protect the effective electrode layer, reduce external electromagnetic interference, and at the same time reduce the concentration of the electric field at the edge of the effective electrode, and reduce the risk of partial discharge. By accurately controlling the length and width of the shielding electrode and the effective electrode, and their relative positions with the ceramic dielectric layer, uniform distribution of the electric field and effective electromagnetic shielding are realized, which helps to reduce the non-uniformity of the electric field inside the capacitor, reduces the risk of partial discharge, and improves the withstand voltage performance of the capacitor.

[0022] 3、The embodiments of the utility model adopt quadrilateral structure for the electrode, and the four top corners are all provided with round corners, which helps to reduce the electric field concentration at the sharp corner of the electrode. Because the sharp corner is often a region with high electric field strength, partial discharge is easy to occur. By providing the round corner, the electrode edge can be smoothed, so that the electric field distribution is more uniform. The radius of the round corner is greater than or equal to twice the thickness of the electrode, which can further reduce the electric field strength at the sharp corner of the electrode. Because the larger radius of the round corner helps to disperse the electric field lines and reduce the risk of electric field concentration, the withstand voltage performance and reliability of the capacitor are improved.

[0023] Overall, the embodiments of the utility model provide the medium and high voltage porcelain dielectric capacitor with shielding electrodes. The capacitor shields the two sides of the effective electrode layer by setting the first shielding electrode layer and the second shielding electrode layer, and limits the electrode structure of the effective electrode layer and the shielding electrode layer, so as to meet the requirements of high power, high voltage bypass and coupling circuit without expanding the volume of the capacitor. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the utility model, and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0025] Figure 1 The structure schematic diagram of the medium and high voltage porcelain dielectric capacitor with shielding electrodes provided by the embodiments of the utility model is shown in the figure.

[0026] Figure 2 The detailed structure schematic diagram of the medium and high voltage porcelain dielectric capacitor with shielding electrodes provided by the embodiments of the utility model is shown in the figure.

[0027] Figure 3 The potential test situation diagram of the capacitor without shielding electrode layer in the prior art is shown in the figure.

[0028] Figure 4The electric potential test condition graph when the inner electrode is a right angle in the middle and high voltage porcelain dielectric capacitor is provided for the embodiment of the utility model;

[0029] Figure 5 The electric field test condition graph when the inner electrode is a right angle in the middle and high voltage porcelain dielectric capacitor is provided for the embodiment of the utility model;

[0030] Figure 6 The electric potential test condition graph when the inner electrode is a round angle in the middle and high voltage porcelain dielectric capacitor is provided for the embodiment of the utility model;

[0031] Figure 7 The electric field test condition graph when the inner electrode is a round angle in the middle and high voltage porcelain dielectric capacitor is provided for the embodiment of the utility model.

[0032] Markings in the drawings and corresponding component names:

[0033] 100-effective electric layer, 110-effective unit, 111-first effective electrode, 112-second effective electrode, 113-first ceramic dielectric layer;

[0034] 200-first shielding electric layer, 210-shielding unit, 211-first shielding electrode, 212-second shielding electrode, 213-second ceramic dielectric layer;

[0035] 300-second shielding electric layer, 400-round angle. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the utility model.

[0038] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0039] In the description of the utility model, it needs to explain, the term "first", "second", "third" and so on are only used for distinguishing description, and cannot be understood as indicating or suggesting relative importance.

[0040] Embodiment

[0041] As Figures 1-2 shown, the utility model discloses a high voltage porcelain dielectric capacitor with shielding electrode, including effective electric layer 100, and the axial both ends of effective electric layer 100 are provided with first shielding electric layer 200 and second shielding electric layer 300 respectively;Effective electric layer 100 includes a plurality of staggered effective unit 110, and single effective unit 110 includes first effective electrode 111, second effective electrode 112 and first ceramic dielectric layer 113, and first effective electrode 111 and second effective electrode 112 are arranged at the transverse both sides of first ceramic dielectric layer 113 respectively, and the length of first effective electrode 111 is greater than the length of second effective electrode 112;First shielding electric layer 200 and second shielding electric layer 300 all contain at least one shielding unit 210, and shielding unit 210 includes first shielding electrode 211, second shielding electrode 212 and second ceramic dielectric layer 213, and first shielding electrode 211 and second shielding electrode 212 are arranged at the transverse both sides of second ceramic dielectric layer 213 respectively, and are arranged axially symmetrically. Specifically, effective electric layer 100 is composed of a plurality of staggered effective unit 110, and each effective unit 110 includes first effective electrode 111, second effective electrode 112 and first ceramic dielectric layer 113. The staggered structure can increase the capacitance value of the capacitor while maintaining a small volume. First effective electrode 111 and second effective electrode 112 are arranged at the transverse both sides of first ceramic dielectric layer 113 respectively, and the length of first effective electrode 111 is greater than the length of second effective electrode 112, which helps to optimize the electric field distribution, reduce the electric field concentration and reduce the risk of partial discharge. The axial both ends of effective electric layer 100 are provided with first shielding electric layer 200 and second shielding electric layer 300 respectively, which reduces the influence of external electromagnetic interference on the internal electric field of the capacitor. Each shielding electric layer contains at least one shielding unit 210, and the shielding unit 210 is composed of first shielding electrode 211, second shielding electrode 212 and second ceramic dielectric layer 213, and the symmetrical layout helps to uniformly distribute the electric field, reduce the electric field concentration and improve the insulation performance of the capacitor.

[0042] In the utility model embodiment, through the cooperation of effective electric layer 100 and shielding electric layer, the shielding electric layer can effectively shield external electromagnetic interference, protect the stability of the internal electric field of the capacitor and reduce the influence of electromagnetic interference on the performance of the capacitor. The capacitor can withstand higher voltage at a small volume, meet the requirements of high-power, high-voltage bypass and coupling circuit, and the shielding electrode reduces the edge effect and leakage current, reduces the risk of corona discharge and improves the reliability and stability of the capacitor.

[0043] In order to better adapt to different scenes, the first shielding electric layer 200 can be set to include a plurality of shielding units 210, and the plurality of shielding units 210 are arranged in overlap; the second shielding electric layer 300 is set to include a plurality of shielding units 210, and the plurality of shielding units 210 are arranged in overlap. It should be noted that the number of shielding units 210 contained in the first shielding electric layer 200 and the second shielding electric layer 300 is not limited here, and only one shielding unit 210 can be set, or two, three, or even the number of shielding units 210 contained in the first shielding electric layer 200 and the second shielding electric layer 300 can be inconsistent, and the actual needs can be set.

[0044] As a preferred embodiment of the utility model, the length of the first shielding electrode 211 can be set to be greater than the length of the second effective electrode 112, which can provide more comprehensive shielding coverage, especially at the two ends of the axial direction of the capacitor, which helps to more effectively reduce the influence of external electromagnetic interference on the electric field inside the capacitor, protect the stability and performance of the capacitor in a high-voltage environment, and at the same time, help to reduce the edge effect and improve the withstand voltage performance of the capacitor. More preferably, the width of the first shielding electrode 211 is greater than the width of the first effective electrode 111 and the second effective electrode 112, and the center line of the outer side line of the first shielding electrode 211 and the center line of the outer side line of the first effective electrode 111 is perpendicular to the first ceramic dielectric layer 113 and the second ceramic dielectric layer 213; the center line of the outer side line of the second shielding electrode 212 and the center line of the outer side line of the second effective electrode 112 is perpendicular to the first ceramic dielectric layer 113 and the second ceramic dielectric layer 213. By increasing the width and vertical layout, the electric field distribution is optimized, the edge effect is further reduced, and the withstand voltage performance and reliability of the capacitor are improved, so that the capacitor can withstand higher voltage under small volume, meet the requirements of large power, high voltage bypass and coupling circuit.

[0045] Further, the electrode thicknesses of the first shielding electrode 211, the second shielding electrode 212, the first active electrode 111 and the second active electrode 112 are equal. Equal electrode thicknesses can ensure more uniform and consistent electric field distribution inside the capacitor, and can more easily control and optimize the performance of the capacitor, such as capacitance and voltage withstand performance. Preferably, the first shielding electrode 211, the second shielding electrode 212, the first active electrode 111 and the second active electrode 112 are all quadrilateral structures, and the four corners are all provided with rounded corners 400. Specifically, the quadrilateral structure helps to achieve uniform distribution of the electric field, and the rounded corners 400 can reduce the electric field concentration at the sharp corners, because the sharp corners are often areas with high electric field strength, and are prone to partial discharge. By providing the rounded corners 400, the electrode edges can be smoothed, making the electric field distribution more uniform and reducing the risk of partial discharge. At the same time, the rounded corners 400 can reduce the risk of electrode cracking due to thermal expansion or mechanical stress, thereby improving the durability and reliability of the capacitor. More preferably, the radius of the rounded corners 400 is greater than or equal to twice the electrode thickness, and a larger radius of the rounded corners 400 helps to improve the mechanical strength of the electrode, reduce the risk of electrode cracking due to thermal expansion or mechanical stress, thereby improving the durability and reliability of the capacitor, while further reducing electric field concentration, improving mechanical strength and optimizing capacitor performance.

[0046] As a preferred embodiment of the present application, the thickness of each first ceramic dielectric layer 113 is equal, and the thickness of each second ceramic dielectric layer 213 is equal. It should be noted that in other embodiments, the thickness of each first ceramic dielectric layer 113 can also be set to be unequal, which is not limited here. Returning to the embodiment of the present application, it is helpful to further optimize the uniform distribution of the electric field and improve the reliability and stability of the capacitor. More preferably, the thickness of a single first ceramic dielectric layer 113 is equal to the thickness of a single second ceramic dielectric layer 213.

[0047] Further, the first shielding electrode 211, the second shielding electrode 212, the first active electrode 111 and the second active electrode 112 are all made of Ni. As a base metal, nickel has a lower cost than traditional noble metals such as gold (Au), platinum (Pt) and silver (Ag), which helps to reduce the production cost of the capacitor. At the same time, it also has advantages such as high-temperature resistance, high electrical conductivity, high-frequency characteristics, small electron mobility and good ohmic contact, which helps to improve the performance and reliability of the capacitor.

[0048] In order to better demonstrate the advantages of the embodiment of the present application, the capacitor without a shielding electrode in the prior art, the rounded corner electrode capacitor of the embodiment of the present application, and the right-angled electrode capacitor of other embodiments of the present application are simulated and tested, and the test results are shown in Table 1. Figures 3-7 Figure 3 ​For the potential test situation of the capacitor without shielding electrode in the art, Figure 4 and Figure 5 are the potential and electric field test situations of the right-angle electrode capacitor of other embodiments of the utility model respectively, Figure 6 and Figure 7 are the potential and electric field test situations of the round-angle electrode capacitor of the embodiment of the utility model respectively, through Figures 3-7 It can be known by comparison that the shielding electrode can effectively block the diffusion of the electric field to the edge of the capacitor, thereby reducing the unevenness of the edge electric field, reducing the edge effect and leakage current to improve the withstand voltage performance of the capacitor and reduce the risk of corona discharge, adopting the inner electrode arc design can smooth the electrode edge, so that the electric field distribution is more uniform, thereby reducing the strong electric field concentration, optimizing the local discharge or reducing the insulation performance. In the embodiment of the utility model, Ni is used to replace the traditional PME high-voltage product (Pd / Ag), and the BME high-voltage product can effectively reduce the cost, and at the same time, a higher volume ratio can be realized to meet the market development trend (small volume and large capacity).

[0049] The above only describes the preferred embodiments of the utility model and is not used to limit the utility model, and for those skilled in the art, the utility model can have various changes and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model. It should be noted that the structures or components illustrated in the drawings are not necessarily drawn to scale, and the utility model omits the description of known components and processing technologies and processes to avoid unnecessary limitation of the utility model.

Claims

1. A medium-high voltage porcelain dielectric capacitor with shielded electrodes, characterized in that, The effective electric layer (100) is provided with a first shielding electric layer (200) and a second shielding electric layer (300) at two axial ends thereof respectively; The effective electric layer (100) comprises a plurality of effective units (110) stacked alternately, and each effective unit (110) comprises a first effective electrode (111), a second effective electrode (112) and a first ceramic dielectric layer (113), the first effective electrode (111) and the second effective electrode (112) are arranged at two lateral sides of the first ceramic dielectric layer (113) respectively, and the length of the first effective electrode (111) is greater than that of the second effective electrode (112); The first shielding electric layer (200) and the second shielding electric layer (300) each comprise at least one shielding unit (210), and the shielding unit (210) comprises a first shielding electrode (211), a second shielding electrode (212) and a second ceramic dielectric layer (213), the first shielding electrode (211) and the second shielding electrode (212) are arranged at two lateral sides of the second ceramic dielectric layer (213) respectively, and are arranged in axial symmetry along the axial direction.

2. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 1, characterized in that, The first shielding electric layer (200) comprises a plurality of shielding units (210), and the plurality of shielding units (210) are arranged in overlap. The second shielding electric layer (300) comprises a plurality of shielding units (210), and the plurality of shielding units (210) are arranged in overlap.

3. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 1, characterized in that, The length of the first shielding electrode (211) is greater than that of the second effective electrode (112).

4. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 3, characterized in that, The width of the first shielding electrode (211) is greater than that of the first effective electrode (111) and the second effective electrode (112), and the center line of the outer side of the first shielding electrode (211) is perpendicular to the first ceramic dielectric layer (113) and the second ceramic dielectric layer (213). The center line of the outer side of the second shielding electrode (212) is perpendicular to the first ceramic dielectric layer (113) and the second ceramic dielectric layer (213).

5. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 1, characterized in that, The electrode thicknesses of the first shielding electrode (211), the second shielding electrode (212), the first effective electrode (111) and the second effective electrode (112) are equal.

6. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 5, characterized in that, The first shielding electrode (211), the second shielding electrode (212), the first effective electrode (111) and the second effective electrode (112) are all in quadrilateral structure, and four corners are all provided with round corners (400).

7. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 6, characterized in that, The radius of the round corner (400) is greater than or equal to twice the electrode thickness.

8. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 1, characterized in that, The thicknesses of each first ceramic dielectric layer (113) are equal, and the thicknesses of each second ceramic dielectric layer (213) are equal.

9. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 8, characterized in that, The thickness of each first ceramic dielectric layer (113) is equal to that of each second ceramic dielectric layer (213).

10. A medium-high voltage porcelain capacitor with shielded electrodes according to claim 5, characterized in that, The first shielding electrode (211), the second shielding electrode (212), the first effective electrode (111) and the second effective electrode (112) are all made of Ni.

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