阅读说明：本技术 一种多层陶瓷电容器 (Multilayer ceramic capacitor ) 是由 黎兆早 余恺为 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种多层陶瓷电容器,所述多层陶瓷电容器包括中心柱体、内电极、陶瓷介电层；所述内电极以中心柱体为中心周期性交替设置,形成回字形结构；所述内电极之间设有陶瓷介电层；所述内电极一端与外电极相连。有益效果：回字形内电极结构,显著降低了器件电场边缘效应,提升器件的电容值,降低边缘击穿概率,同时该结构抑制了传统平面式陶瓷电容器介质层由于应力导致的曲翘问题产生。一体化打印,提升了层与层的界面结合力。进一步的通过内电极未闭合面的贯通电极的设置,降低了等效串联电阻,进一步提升了多层陶瓷电容器的性能。(The invention discloses a multilayer ceramic capacitor, which comprises a central cylinder, an inner electrode and a ceramic dielectric layer, wherein the central cylinder is provided with a plurality of through holes; the inner electrodes are periodically and alternately arranged by taking the central cylinder as the center to form a zigzag structure; a ceramic dielectric layer is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode. Has the advantages that: the square-clip-shaped inner electrode structure obviously reduces the electric field edge effect of the device, improves the capacitance value of the device, reduces the edge breakdown probability, and simultaneously inhibits the warping problem of the traditional plane type ceramic capacitor dielectric layer caused by stress. And the integrated printing improves the interface bonding force between layers. And further through the arrangement of the through electrode on the non-closed surface of the inner electrode, the equivalent series resistance is reduced, and the performance of the multilayer ceramic capacitor is further improved.)

1. A multilayer ceramic capacitor, characterized in that: the multilayer ceramic capacitor comprises a central cylinder (1), an inner electrode and a ceramic dielectric layer (4); the inner electrodes are periodically and alternately arranged by taking the central cylinder (1) as a center to form a zigzag structure; a ceramic dielectric layer (4) is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode.

2. A multilayer ceramic capacitor as claimed in claim 1, wherein: the multilayer ceramic capacitor further includes a through electrode (6); the inner electrodes comprise a first inner electrode (2) and a second inner electrode (3); the first inner electrode (2) is a positive electrode, and the second inner electrode (3) is a negative electrode; the through electrode (6) connects the other ends of the internal electrodes having the same polarity through in the Y direction and the Z direction.

3. A multilayer ceramic capacitor as claimed in claim 2, wherein: the through electrode (6) penetrates through the central column body (1).

4. A multilayer ceramic capacitor as claimed in claim 2, wherein: the edge line of the side wall of the through electrode (6) is arranged between the edge of the other end of the inner electrode and the inner side of the outer electrode (5); the distance between the edge line of the side wall of the through electrode (6) and the edge of the other end of the internal electrode is L₃The width from the edge of the other end of the inner electrode to the inner side of the outer electrode (5) is L₁The width of the through electrode (6) is L₂，L₂≤L₁/3，0≤L₃≤L₂/2。

5. A multilayer ceramic capacitor as claimed in claim 1, wherein: the multilayer ceramic capacitor is one of a cuboid, a cylinder and a polygonal prism.

6. A multilayer ceramic capacitor as claimed in claim 1, wherein: the multilayer ceramic capacitor is prepared by adopting a 3D printing and instant ultraviolet curing mode; the through electrode (6) is prepared by adopting a multi-head printing mode.

7. A multilayer ceramic capacitor as claimed in claim 1, wherein: the raw materials of the ceramic dielectric layer (4) comprise the following components: by weight, 20-35 parts of polyurethane acrylate resin, 25-40 parts of reaction diluent, 0.1-0.5 part of nano silicon dioxide, 1-3 parts of dispersing agent, 5-10 parts of photoinitiator, 2-4 parts of auxiliary initiator, 0.2-0.5 part of flatting agent and 100 parts of ceramic powder.

8. A multilayer ceramic capacitor as claimed in claim 7, wherein: BaTiO of which the particle diameter D50 is 500nm₃(ii) a The size of the nano silicon dioxide is 5-10 nm.

9. A multilayer ceramic capacitor as claimed in claim 1, wherein: the raw materials of the inner electrode comprise the following components: by weight, 20-35 parts of polyurethane acrylate resin, 25-40 parts of reaction diluent, 0.3-0.6 part of nano silicon dioxide, 1-3 parts of dispersing agent, 5-10 parts of photoinitiator, 2-4 parts of auxiliary initiator, 0.2-0.5 part of flatting agent and 100 parts of conductive metal.

10. A multilayer ceramic capacitor as claimed in claim 1, wherein: the conductive metal is one or more of Ag, Pd, Au, Pt, Ni, Sn, Cu, W and Ti.

Technical Field

The invention relates to the field of ceramic capacitors, in particular to a multilayer ceramic capacitor.

Background

The multilayer ceramic capacitor is a multilayer structure formed by laminating three major parts of a ceramic dielectric layer, a metal inner electrode and a metal outer electrode. Therefore, the traditional preparation method usually adopts the tape casting type to prepare the sheets and then laminate, but the inner electrode of the traditional tape casting type multilayer ceramic capacitor adopts the planar type interval arrangement design, and except for one side which is contacted with the outer electrode, other three boundaries are all limited boundaries, and the edge effect is strong. Especially, when the thickness of the ceramic dielectric layer is close to the manufacturing limit, the improvement of the capacitance value and the reliability of the capacitor tends to the upper limit and is influenced by the factor that the thickness cannot be further reduced, the edge effect cannot be weakened by reducing the thickness of the dielectric layer, and the influence degree of the edge effect caused by the limited cut-off boundary on the performance of the device is obvious at the moment. At present, enterprises such as samsung in korea carry out related research aiming at the optimization of a planar inner electrode structure, but related technical methods are that the connection of inner electrode devices with the same property is completed through holes, the capability of optimizing the edge effect is not provided, and the problem of poor edge effect of an inner electrode electric field still exists.

Therefore, it is important to solve the above problems and provide a multilayer ceramic capacitor having a low edge effect, which can ensure the reliability of the capacitor and increase the stability of the capacitor.

Disclosure of Invention

An object of the present invention is to provide a multilayer ceramic capacitor which solves the problems set forth in the background art described above.

In order to solve the technical problems, the invention provides the following technical scheme:

a multilayer ceramic capacitor comprising a central cylinder, an inner electrode, a ceramic dielectric layer; the inner electrodes are periodically and alternately arranged by taking the central cylinder as the center to form a zigzag structure; a ceramic dielectric layer is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode. And the other end of the internal electrode is selectively provided with a through electrode.

The multilayer ceramic capacitor further includes a through electrode; the internal electrodes include a first internal electrode and a second internal electrode; the first internal electrode is a positive electrode, and the second internal electrode is a negative electrode; the through electrode connects the other end of the inner electrode with the same polarity in a through manner in the Y direction and the Z direction.

Preferably, the through electrode penetrates through the central column.

Preferably, the edge line of the side wall of the through electrode is arranged at the edge of the other end of the inner electrode and in the outer electrodeBetween the sides; the distance between the edge line of the side wall of the through electrode and the edge of the other end of the internal electrode is L₃The width from the edge of the other end of the inner electrode to the inner side of the outer electrode is L₁The width of the through electrode is L₂，L₂≤L₁/3，0≤L₃≤L₂/2。

Preferably, the multilayer ceramic capacitor is one of a cuboid, a cylinder and a polygonal prism.

Optimally, the multilayer ceramic capacitor is prepared in a 3D printing mode; the multilayer ceramic capacitor is prepared by adopting a 3D printing and instant ultraviolet curing mode; the through electrode is prepared by multi-head printing, and the multi-head printing provides coating of different materials on the same plane.

Preferably, the raw materials of the ceramic dielectric layer comprise the following components: by weight, 20-35 parts of polyurethane acrylate resin, 25-40 parts of reaction diluent, 0.1-0.5 part of nano silicon dioxide, 1-3 parts of dispersing agent, 5-10 parts of photoinitiator, 2-4 parts of auxiliary initiator, 0.2-0.5 part of flatting agent and 100 parts of ceramic powder.

Preferably, the ceramic powder has a BaTiO particle size D50 of 500nm₃(ii) a The size of the nano silicon dioxide is 5-10 nm.

Preferably, the raw materials of the inner electrode comprise the following components: by weight, 20-35 parts of polyurethane acrylate resin, 25-40 parts of reaction diluent, 0.3-0.6 part of nano silicon dioxide, 1-3 parts of dispersing agent, 5-10 parts of photoinitiator, 2-4 parts of auxiliary initiator, 0.2-0.5 part of flatting agent and 100 parts of conductive metal.

Preferably, the conductive metal is one or more of Ag, Pd, Au, Pt, Ni, Sn, Cu, W and Ti.

In the technical scheme, in order to solve the problem of poor electric field edge effect of the inner electrode of the traditional multilayer ceramic capacitor, the multilayer ceramic capacitor with the borderless inner electrode is designed by utilizing a 3D printing technology and a surrounding coating and ultraviolet curing mode, so that the edge effect of the traditional device is improved, and the stability and other performances of the capacitor are improved.

(1) According to the scheme, the ultraviolet curing slurry with high solid content is combined with a 3D three-dimensional printing and instant ultraviolet curing mode, the first inner electrode, the ceramic dielectric layer and the second inner electrode are designed to form a layer-by-layer semi-closed loop, and the semi-closed loop, the semi-closed loop and the second inner electrode are periodically and alternately arranged to form the zigzag inner electrode.

The design of the square-shaped structure forms a borderless structure in the dimensions of the Y direction and the Z direction, so that the electric field edge effect of a device is greatly reduced, the capacitance value of a capacitor is improved, and the probability of edge breakdown is reduced. In the dimension of the X direction, the device is symmetrically contracted during subsequent sintering, stress offset is formed around the central column, and the warping problem of the traditional planar ceramic capacitor dielectric layer caused by internal stress is reduced.

The 3D printing technology is integrated, the problem that interlayer gaps are obvious due to the traditional tape casting type laminating process is solved, and the interface bonding force between layers is improved. Meanwhile, the electrode penetration of the non-closed surface of the inner electrode is completed, the equivalent series resistance is reduced, and the performance of the device is further improved.

(2) In the scheme, a central column body is arranged, and the shape of the central column body determines the shape of the appearance. The choice of the material of the central cylinder is versatile. When the material of the central cylinder is the same as that of the ceramic dielectric layer, the material of the inner electrode is directly coated on the central cylinder; when the material of the central cylinder is the same as that of the inner electrode, the central cylinder is directly coated with a ceramic dielectric layer material; when the central cylinder is a conductive metal, such as copper, silver-copper alloy, etc., the material of the ceramic dielectric layer or the material of the internal electrode is directly coated. When the central column body is made of pure metal, the preferred scheme is that the inner electrode material is firstly coated, and then the ceramic dielectric layer is coated, so that the transition of pure metal, metal slurry and ceramic slurry is completed, and the binding force of a device is ensured.

(3) In the scheme, the ceramic main body includes a fifth surface S5 and a sixth surface S6 opposite to each other in the X direction; a third surface S3 and a fourth surface S4 opposite to each other in the Y direction; a first surface S1 and a second surface S2 opposite to each other in the Z direction; and through electrodes are arranged in the Y direction and the Z direction and respectively connect the first internal electrodes with the same polarity and the second electrodes with the same polarity in a penetrating way. The through electrode can improve the equivalent series resistance of the device and reduce the edge effect.

When the through electrode is manufactured, a region needing to be penetrated is reserved in a multi-head printing mode to be filled with a second material, and through connection is achieved.

The through electrode can be selected to penetrate through the central column or not. In general, the through-holes are selected so that the entire electrode is closed, thereby further reducing the equivalent series resistance. When the central cylinder is made of metal materials, the through hole is not easy to manufacture and is not easy to be communicated, and the central cylinder is not communicated for ensuring the mechanical property.

The width of the through electrode and the position of the through electrode are limited so as to avoid short circuit and ensure the performance of the multilayer ceramic capacitor.

(4) In the scheme, the materials of the ceramic dielectric layer and the internal electrode are slurry containing a photocuring material, and D50 peak values of the grain diameters of the ceramic powder and the conductive metal are both in the order of 500 nm.

The paste is high solid-phase paste, and compared with common paste (low solid-phase content) for printing the capacitor, the paste is easier to mold, the shrinkage rate in the sintering process after molding is low, and the stability of the capacitor is enhanced.

In addition, the size of the nano silicon dioxide in the material is 5-10 nm, the nano silicon dioxide exists as a scattering function during ultraviolet light curing, ultraviolet light is scattered to the side surface under limited irradiation, the coating is cured quickly, timely curing is achieved, and conformal preparation of the coating is completed. In addition, in the subsequent sintering process, the method can assist in filling gaps and can be used as a reinforcing agent and a sintering aid to enhance the interface bonding force.

Has the advantages that: (1) the square-clip-shaped inner electrode structure obviously reduces the electric field edge effect of the device, improves the capacitance value of the capacitor and reduces the edge breakdown probability; the problem of warping of the dielectric layer of the traditional planar ceramic capacitor caused by internal stress is inhibited. (2) The integrated printing improves the interface binding force between layers, and completes the arrangement of the through electrode on the non-closed surface of the inner electrode, thereby reducing the equivalent series resistance and further improving the performance of the multilayer ceramic capacitor; (3) the high solid phase slurry is matched with the ultraviolet curing in time, so that the shrinkage rate of the subsequent sintering process is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a rectangular parallelepiped multilayer ceramic capacitor;

FIG. 2 is a schematic diagram of a cylindrical multilayer ceramic capacitor;

FIG. 3 is a partial perspective view of a cylindrical multilayer ceramic capacitor;

FIG. 4 is a schematic X-Z plane view of a rectangular parallelepiped multilayer ceramic capacitor;

FIG. 5 is a schematic Y-Z plane view of a rectangular parallelepiped multilayer ceramic capacitor;

FIG. 6 is a cross-sectional view of a multilayer ceramic capacitor provided with through electrodes in an X-Z plane;

FIG. 7 is a cross-sectional view of a multilayer ceramic capacitor in the X-Z plane without passing through the center post;

FIG. 8 is a schematic view of arrangement of through-electrode positions in a multilayer ceramic capacitor 1;

FIG. 9 is a schematic view of arrangement of through-electrode positions in a multilayer ceramic capacitor 2;

in the figure: 1 a central column; 2 a first internal electrode; 3 a second internal electrode; 4 a ceramic dielectric layer; 5, an outer electrode; 6 through electrode.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

Example 1:

as shown in fig. 1, 5, 6, and 8, in the present embodiment, the multilayer ceramic capacitor has a rectangular parallelepiped shape.

A multilayer ceramic capacitor includes a central cylinder 1, an inner electrode, a ceramic dielectric layer 4; the inner electrodes are periodically and alternately arranged by taking the central cylinder 1 as a center to form a zigzag structure; a ceramic dielectric layer 4 is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode.

Further, the multilayer ceramic capacitor further includes a through electrode 6; the internal electrodes include a first internal electrode 2 and a second internal electrode 3; the first inner electrode 2 is a positive electrode, and the second inner electrode 3 is a negative electrode; the through-electrodes 6 connect the other ends of the internal electrodes having the same polarity through in the Y direction and the Z direction.

Further, the through electrode 6 penetrates the center post 1.

The edge line of the side wall of the through electrode 6 is arranged between the edge of the other end of the inner electrode and the inner side of the outer electrode 5; the distance between the edge line of the side wall of the through electrode 6 and the edge of the other end of the internal electrode is L₃The width from the edge of the other end of the inner electrode to the inner side of the outer electrode 5 is L₁The width of the through electrode 6 is L₂，L₂＝L₁/3，L₃＝0。

In this embodiment, the material of the central column 1 is the same as that of the ceramic dielectric layer 4; the material of the inner electrode is directly coated.

The ceramic dielectric layer 4 is made of ultraviolet curing ceramic slurry containing ceramic powder; the ceramic powder is BaTiO₃(ii) a The raw materials of the ultraviolet curing ceramic slurry comprise the following materials: 35 parts of polyurethane acrylate resin, 40 parts of reaction diluent, 0.5 part of nano silicon dioxide, 3 parts of dispersing agent, 10 parts of photoinitiator, 4 parts of auxiliary initiator and 0.5 part of flatting agent, and 100 parts of ceramic powder;

the material of the inner electrode is ultraviolet light curing electrode slurry containing conductive metal; the conductive metal is Ag; the raw materials of the ultraviolet light curing electrode slurry comprise the following materials: by mass, 35 parts of urethane acrylate resin, 40 parts of reaction diluent, 0.6 part of nano silicon dioxide, 3 parts of dispersing agent, 10 parts of photoinitiator, 4 parts of co-initiator, 0.5 part of flatting agent and 100 parts of conductive metal.

Example 2:

as shown in fig. 1, 5, 6, 9; the multilayer ceramic capacitor of this example is a rectangular parallelepiped, and the position where the through-electrode is provided is different from that of example 1.

A multilayer ceramic capacitor includes a central cylinder 1, an inner electrode, a ceramic dielectric layer 4; the inner electrodes are periodically and alternately arranged by taking the central cylinder 1 as a center to form a zigzag structure; a ceramic dielectric layer 4 is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode.

Further, the multilayer ceramic capacitor further includes a through electrode 6; the internal electrodes include a first internal electrode 2 and a second internal electrode 3; the first inner electrode 2 is a positive electrode, and the second inner electrode 3 is a negative electrode; the through-electrodes 6 connect the other ends of the internal electrodes having the same polarity through in the Y direction and the Z direction.

Further, the through electrode 6 penetrates the center post 1.

The edge line of the side wall of the through electrode 6 is arranged between the edge of the other end of the inner electrode and the inner side of the outer electrode 5; the distance between the edge line of the side wall of the through electrode 6 and the edge of the other end of the internal electrode is L₃The width from the edge of the other end of the inner electrode to the inner side of the outer electrode 5 is L₁The width of the through electrode 6 is L₂，L₂＝L₁/3，L₃＝L₂/2。

In this embodiment, the material of the central column 1 is the same as the material of the inner electrode; the material of the ceramic dielectric layer 4 is directly coated.

The ceramic dielectric layer 4 is made of ultraviolet curing ceramic slurry containing ceramic powder; the ceramic powder is BaTiO₃(ii) a The raw materials of the ultraviolet curing ceramic slurry comprise the following materials: by weight, 20 parts of polyurethane acrylate resin, 25 parts of reaction diluent, 0.1 part of nano silicon dioxide, 1 part of dispersing agent, 5 parts of photoinitiator, 2 parts of co-initiator and 0.2 part of flatting agent, and 100 parts of ceramic powder;

the material of the inner electrode is ultraviolet light curing electrode slurry containing conductive metal; the conductive metal is Ag-Cu alloy; the raw materials of the ultraviolet light curing electrode slurry comprise the following materials: by mass, 20 parts of urethane acrylate resin, 25 parts of reaction diluent, 0.3 part of nano silicon dioxide, 1 part of dispersing agent, 5 parts of photoinitiator, 2 parts of co-initiator, 0.2 part of flatting agent and 100 parts of conductive metal.

Example 3:

as shown in fig. 1, 4 and 5, the multilayer ceramic capacitor of the present embodiment is a rectangular parallelepiped and is not provided with a through electrode.

A multilayer ceramic capacitor includes a central cylinder 1, an inner electrode, a ceramic dielectric layer 4; the inner electrodes are periodically and alternately arranged by taking the central cylinder 1 as a center to form a zigzag structure; a ceramic dielectric layer 4 is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode.

Further, the internal electrodes include a first internal electrode 2 and a second internal electrode 3;

in this embodiment, the material of the central column 1 is the same as that of the ceramic dielectric layer 4; the material of the inner electrode is directly coated.

The ceramic dielectric layer 4 is made of ultraviolet curing ceramic slurry containing ceramic powder; the ceramic powder is BaTiO₃(ii) a The raw materials of the ultraviolet curing ceramic slurry comprise the following materials: by weight, 30 parts of polyurethane acrylate resin, 30 parts of reaction diluent, 0.2 part of nano silicon dioxide, 2 parts of dispersing agent, 8 parts of photoinitiator, 3 parts of auxiliary initiator and 0.3 part of flatting agent, and 100 parts of ceramic powder;

the material of the inner electrode is ultraviolet light curing electrode slurry containing conductive metal; the conductive metal is Ag; the raw materials of the ultraviolet light curing electrode slurry comprise the following materials: by mass, 30 parts of polyurethane acrylate resin, 30 parts of reaction diluent, 0.5 part of nano silicon dioxide, 2 parts of dispersing agent, 8 parts of photoinitiator, 3 parts of co-initiator, 0.3 part of flatting agent and 100 parts of conductive metal.

Example 4:

as shown in fig. 1, 5, and 8, in the present embodiment, the multilayer ceramic capacitor has a rectangular parallelepiped shape, and the through electrode does not penetrate the center pillar.

A multilayer ceramic capacitor includes a central cylinder 1, an inner electrode, a ceramic dielectric layer 4; the inner electrodes are periodically and alternately arranged by taking the central cylinder 1 as a center to form a zigzag structure; a ceramic dielectric layer 4 is arranged between the inner electrodes; one end of the inner electrode is connected with the outer electrode.

Further, the multilayer ceramic capacitor further includes a through electrode 6; the internal electrodes include a first internal electrode 2 and a second internal electrode 3; the first inner electrode 2 is a positive electrode, and the second inner electrode 3 is a negative electrode; the through-electrodes 6 connect the other ends of the internal electrodes having the same polarity through in the Y direction and the Z direction.

The edge line of the side wall of the through electrode 6 is arranged between the edge of the other end of the inner electrode and the inner side of the outer electrode 5; the distance between the edge line of the side wall of the through electrode 6 and the edge of the other end of the internal electrode is L₃The width from the edge of the other end of the inner electrode to the inner side of the outer electrode 5 is L₁The width of the through electrode 6 is L₂，L₂＝L₁/3，L₃＝0。

In this embodiment, the central column 1 is made of a copper column; the material of the inner electrode is directly coated.

The ceramic dielectric layer 4 is made of ultraviolet curing ceramic slurry containing ceramic powder; the ceramic powder is BaTiO₃(ii) a The raw materials of the ultraviolet curing ceramic slurry comprise the following materials: 35 parts of polyurethane acrylate resin, 40 parts of reaction diluent, 0.5 part of nano silicon dioxide, 3 parts of dispersing agent, 10 parts of photoinitiator, 4 parts of auxiliary initiator and 0.5 part of flatting agent, and 100 parts of ceramic powder;

the material of the inner electrode is ultraviolet light curing electrode slurry containing conductive metal; the conductive metal is Ag; the raw materials of the ultraviolet light curing electrode slurry comprise the following materials: by mass, 35 parts of urethane acrylate resin, 40 parts of reaction diluent, 0.6 part of nano silicon dioxide, 3 parts of dispersing agent, 10 parts of photoinitiator, 4 parts of co-initiator, 0.5 part of flatting agent and 100 parts of conductive metal.

Example 5:

referring to fig. 2 and 3, in the present embodiment, the multilayer ceramic capacitor is shaped as a cylinder; the rest of the setup was the same as in example 1.

Experiments and conclusions: through simulation calculation and capacitance value comparison, it can be found that the arrangement of the loop-shaped inner electrode in embodiment 3 enables the edge field effect to be only on the side which is not closed in the shape of a square, and the other three sides are in a closed state, which is equivalent to no boundary, and the processing mode can reduce the edge effect by 30%; if the side that is not closed in the square shape is connected by the through electrode (6), as shown in example 1, the edge effect can be reduced by 50%.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.