Multilayer ceramic capacitor

Abstract

The utility model discloses a multilayer ceramic capacitor, which comprises a laminated body, a first external electrode and a second external electrode, the laminated body is provided with a first main surface and a second main surface which are opposite to each other in a lamination direction, a first side surface and a second side surface which are opposite to each other in a width direction, and a first end surface and a second end surface which are opposite to each other in a length direction, and further comprises ceramic columns, the ceramic columns penetrate through the first main surface and the second main surface in the lamination direction of the lamination body. The ceramic column provided by the utility model is an individual which is integrally formed after lamination and lamination, and can reinforce the connection among the dielectric material layer, the first inner electrode and the second inner electrode, thereby effectively preventing the layering and cracking of an MLCC finished product, and improving the production yield and reliability of the multi-layer ceramic capacitor.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic components, and more specifically, to a multilayer ceramic capacitor. Background Art

[0002] Multilayer ceramic capacitors (MLCCs) are a type of ceramic electronic component that features compact structure, high capacitance, and easy installation. They are widely used in electronic products such as imaging devices, computers, personal digital assistants (PDAs), and mobile phones. Imaging devices include liquid crystal displays, plasma display panels, and the like.

[0003] MLCC consists of two or more external electrodes, multiple layers of internal electrodes and multiple layers of dielectric materials, inside which metal internal electrode layers and dielectric material layers are alternately stacked. The general preparation method of MLCC is to first produce dielectric material green sheets by casting, and then print the internal electrode slurry on its surface, and then alternately stack the dielectric material green sheets printed with internal electrode slurry by lamination, and then make MLCC through cutting, sintering, printing external electrodes, burning ends, electroplating and other steps.

[0004] The MLCC finished products obtained by the general preparation method of existing MLCC are prone to delamination and cracking, which has an adverse effect on the reliability of MLCC products. Therefore, it is of great significance to develop a multilayer ceramic capacitor that can effectively prevent delamination and cracking of MLCC finished products. Utility Model Content

[0005] The utility model aims to provide a multilayer ceramic capacitor to solve the problem of delamination and cracking of MLCC finished products.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] In a first aspect, the utility model provides a multilayer ceramic capacitor, comprising:

[0008] a stacked body, a first external electrode and a second external electrode;

[0009] The stacked body has a first main surface and a second main surface opposite to each other in a stacking direction, a first side surface and a second side surface opposite to each other in a width direction, and a first end surface and a second end surface opposite to each other in a length direction, and the stacked body includes a plurality of stacked dielectric material layers and first internal electrodes and second internal electrodes stacked alternately, and each adjacent first internal electrode and second internal electrode is separated by a dielectric material layer;

[0010] The first outer electrode is disposed on the first end surface and is electrically connected to the first inner electrode;

[0011] The second outer electrode is disposed on the second end surface and is electrically connected to the second inner electrode;

[0012] The stacked body further includes a ceramic column, and the ceramic column penetrates the first main surface and the second main surface in the stacking direction of the stacked body.

[0013] The utility model forms ceramic columns by opening pores in a dielectric material green sheet printed with an internal electrode slurry before lamination and pressing, and filling the pores with ceramic column slurry after lamination and pressing. Therefore, the ceramic column established in the utility model is an individual formed in one piece after lamination and pressing, which can strengthen the connection between the dielectric material layer, the first internal electrode and the second internal electrode, effectively prevent delamination and cracking of the MLCC finished product, and improve the production yield and reliability of multilayer ceramic capacitors.

[0014] Preferably, the ceramic column does not penetrate the first internal electrode and the second internal electrode.

[0015] In the present invention, when the ceramic column passes through the first internal electrode and / or the second internal electrode, the established ceramic column is still beneficial to strengthening the connection between the dielectric material layer, the first internal electrode and the second internal electrode, but it will reduce the area of ​​the first / second internal electrode, thereby reducing the capacitance of the multilayer ceramic capacitor.

[0016] Preferably, the number of the ceramic columns is ≥1.

[0017] Preferably, the number of the ceramic columns is 2-4.

[0018] In the present invention, when the number of ceramic pillars is greater than 4, more pores need to be opened when preparing the multilayer ceramic capacitor, which will result in a decrease in the production efficiency of the multilayer ceramic capacitor.

[0019] Preferably, the cross-sectional shape of the ceramic column on the first main surface and / or the second main surface is a triangle, a quadrilateral, a circle, a sector or a polygon, and the quadrilateral is a rectangle, a trapezoid, a parallelogram or a rhombus.

[0020] Preferably, the ceramic column is exposed on the first side surface and / or the second side surface.

[0021] Preferably, the cross-sectional shape of the ceramic column in a direction perpendicular to the first main surface and the second main surface is a triangle or a quadrilateral; the quadrilateral is a rectangle, a trapezoid, a parallelogram or a rhombus.

[0022] More preferably, the cross-sectional shape of the ceramic column on the first side surface and / or the second side surface and / or the first end surface and / or the second end surface is a triangle or a quadrilateral.

[0023] Preferably, the ceramic column is divided into a main body and a protrusion, the main body and the protrusion are connected, and the cross-sectional shape of the main body in a direction perpendicular to the first main surface and the second main surface is a triangle or a quadrilateral; the quadrilateral is a rectangle, a trapezoid, a parallelogram or a rhombus.

[0024] More preferably, a cross-sectional shape of the main body on the first side surface and / or the second side surface and / or the first end surface and / or the second end surface is a triangle or a quadrilateral.

[0025] More preferably, the cross-sectional shape of the protrusion on the first side surface and / or the second side surface and / or the first end surface and / or the second end surface is at least one of a V-shape, a rectangle, a polygon, a curved polygon, and a stepped shape.

[0026] When the protrusion is in a stepped shape, the steps of the protrusion decrease step by step from the first main surface and / or the second main surface toward the middle of the stacked body.

[0027] More preferably, there are gaps between adjacent protrusions.

[0028] More preferably, the ceramic column is located in the middle of the first side surface and / or the second side surface.

[0029] More preferably, the ceramic column is located at the intersection of the first / second side surface and the first / second end surface.

[0030] Preferably, the first external electrode covers the first end surface, part of the first main surface and part of the second main surface, part of the first side surface and part of the second side surface of the stacked body.

[0031] Preferably, the second external electrode covers the second end surface, part of the first main surface and part of the second main surface, part of the first side surface and part of the second side surface of the stacked body.

[0032] In a second aspect, the utility model provides a method for preparing a multilayer ceramic capacitor, comprising:

[0033] S1. Casting the ceramic slurry into a film to obtain a ceramic green sheet;

[0034] S2. Printing a conductive paste for forming an inner electrode on a ceramic green sheet by screen printing to obtain a ceramic green sheet containing an inner electrode;

[0035] S3. Opening pores in the ceramic green sheet containing the inner electrode, laminating and pressing the ceramic green sheets, filling the pores with a ceramic column slurry to form a ceramic column green body, cutting, and obtaining a laminated green body containing a ceramic column green body;

[0036] S4. The green body of the laminate containing the ceramic column is subjected to binder removal and sintering treatment to obtain a laminate containing the ceramic column;

[0037] S5. Coating a conductive paste for forming an external electrode on the first end surface and the second end surface opposite to each other in the length direction of the stack to obtain a stack containing a first external electrode and a second external electrode;

[0038] S6. The stacked body including the first external electrode and the second external electrode is subjected to a sintering and electroplating process to obtain a multi-layer ceramic capacitor (MLCC).

[0039] The preparation method of the multilayer ceramic capacitor of the utility model promotes the discharge of bubbles generated in the lamination and pressing process by opening pores in the ceramic green sheet, prevents the bubbles from being retained in the MLCC, and effectively prevents the MLCC finished product from delamination and cracking; at the same time, the pores are opened in the ceramic green sheet to facilitate the alignment during lamination, which can further ensure the lamination accuracy and improve the production yield and reliability of the multilayer ceramic capacitor.

[0040] Ceramic slurries commonly used in the art can be used in the present invention. The ceramic slurry generally includes ceramic powder, adhesive and solvent; the ceramic powder is ceramic powder commonly used in the art, such as at least one of barium titanate, barium zirconate titanate, strontium titanate, calcium titanate, calcium zirconate, etc.; the adhesive is an adhesive resin commonly used in the art, such as polyvinyl butyral, ethyl cellulose, etc.; the solvent is a solvent commonly used in the art, such as ethanol, toluene, etc.

[0041] In addition, after the ceramic slurry is sintered in step S4 , the binder and solvent in the ceramic slurry will decompose and volatilize, and the remaining part of the ceramic slurry will become the dielectric material of the dielectric material layer.

[0042] The ceramic column slurry used to fill the pores of the utility model can be the same as or different from the ceramic slurry. When the ceramic column slurry is different from the ceramic slurry, it is best to ensure that the thermal expansion coefficients of the ceramic column and the dielectric material layer are similar, because it can prevent the MLCC finished product from being deformed due to sudden temperature changes.

[0043] The material of the first inner electrode and the second inner electrode of the utility model is at least one of nickel (Ni) and its alloys, copper (Cu) and its alloys, palladium (Pd) and its alloys, silver (Ag) and its alloys, gold (Au) and its alloys, platinum (Pt) and its alloys, tin (Sn) and its alloys, tungsten (W) and its alloys, and titanium (Ti) and its alloys.

[0044] The conductive paste for forming the inner electrode of the utility model contains at least one of nickel (Ni) and its alloys, copper (Cu) and its alloys, palladium (Pd) and its alloys, silver (Ag) and its alloys, gold (Au) and its alloys, platinum (Pt) and its alloys, tin (Sn) and its alloys, tungsten (W) and its alloys, and titanium (Ti) and its alloys.

[0045] The material of the first external electrode and the second external electrode of the utility model is at least one of nickel (Ni), silver (Ag), copper (Cu), tin (Sn), gold (Au), and lead (Pb).

[0046] The conductive paste used to form the external electrode of the utility model contains at least one of nickel (Ni), silver (Ag), copper (Cu), tin (Sn), gold (Au) and lead (Pb).

[0047] The conductive paste for forming the inner electrode and the conductive paste for forming the outer electrode of the utility model both contain a binder and a solvent; the binder is a binder resin commonly used in the art, such as polyvinyl butyral, ethyl cellulose, etc.; the solvent is a solvent commonly used in the art, such as ethanol, toluene, etc.

[0048] Preferably, the ratio of the equivalent radius of the pore to the length of the laminate green body is (0.02-0.05):1.

[0049] When the pores are too large, they will occupy the internal electrode area, resulting in a decrease in the performance of the multilayer ceramic capacitor; when the pores are too small, it will increase the process difficulty and reduce the production efficiency of the multilayer ceramic capacitor.

[0050] Preferably, in step S3, the pores are opened at locations on the ceramic green sheet that do not contain internal electrodes.

[0051] Preferably, in step S3, the equivalent radius of the pores is more than one.

[0052] Preferably, in step S3, the cross-sectional shape of the pores on the ceramic green sheet is circular, triangular, quadrilateral, pentagonal, hexagonal, heptagonal or octagonal.

[0053] More preferably, in step S3, when there are two types of equivalent radii of the pores, ceramic green sheets containing pores of different equivalent radii are alternately stacked and pressed.

[0054] More preferably, in step S3, when there are more than two equivalent radii of the pores, the ceramic green sheets are stacked and pressed in this order: the ceramic green sheet with a small equivalent radius of the pore is in the middle of the laminated green body, the ceramic green sheets with a large equivalent radius of the pore are at both ends of the laminated green body, and the size of the equivalent radius of the pore gradually increases from the middle of the laminated green body to both ends of the laminated body in the stacking direction.

[0055] More preferably, in step S3, when the equivalent radius of the pores is two or more and the size of the pores on the single ceramic green sheet gradually decreases in the stacking direction of the stack, the ceramic green sheets are laminated and pressed.

[0056] More preferably, in step S3, when there are more than two equivalent radii of the pores, the ratio of the minimum equivalent radius to the maximum equivalent radius of the pores is (0.5-1):1.

[0057] Compared with the prior art, the beneficial effects of the utility model are:

[0058] The ceramic column established in the utility model is an individual formed in one piece after lamination and pressing, which can strengthen the connection between the dielectric material layer, the first inner electrode and the second inner electrode, effectively prevent the MLCC finished product from delamination and cracking, and improve the production yield and reliability of the multilayer ceramic capacitor.

[0059] The preparation method of the multilayer ceramic capacitor of the utility model promotes the discharge of bubbles generated in the lamination and pressing process by opening pores in the ceramic green sheet, prevents the bubbles from being retained in the MLCC, and effectively prevents the MLCC finished product from delamination and cracking; at the same time, the pores are opened in the ceramic green sheet to facilitate the alignment during lamination, which can further ensure the lamination accuracy and improve the production yield and reliability of the multilayer ceramic capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Schematic diagram of the three-dimensional structure of the multilayer ceramic capacitor of Example 1;

[0061] Figure 2 It is a front view of the multilayer ceramic capacitor of Example 1 along the width direction;

[0062] Figure 3 A top view of the multilayer ceramic capacitor of Example 1 along the stacking direction;

[0063] Figure 4 is a schematic cross-sectional view of the multilayer ceramic capacitor of Example 1 along the length direction, which is Figure 3 Obtained by AA line cutting;

[0064] Figure 5 Schematic diagram of the process of step S4 in the method for preparing a multilayer ceramic capacitor in Example 1;

[0065] Figure 6 This is a schematic diagram of the three-dimensional structure of the multilayer ceramic capacitor of Example 2 after the second outer electrode is hidden;

[0066] Figure 7 Schematic diagram of the process of step S4 in the method for preparing a multilayer ceramic capacitor in Example 2;

[0067] Figure 8It is a front view of the multilayer ceramic capacitor of Example 3 along the width direction;

[0068] Fig. 9 It is a front view of the multilayer ceramic capacitor of Example 4 along the width direction;

[0069] Fig.10 It is a front view of the multilayer ceramic capacitor of Example 5 along the width direction;

[0070] Fig.11 A top view of the multilayer ceramic capacitor of Example 6 along the stacking direction;

[0071] In the figure, the stack 1, the first outer electrode 21, the second outer electrode 22, the first main surface 31, the second main surface 32, the first side surface 41, the second side surface 42, the first end surface 51, the second end surface 52, the dielectric material layer 6, the first inner electrode 71, the second inner electrode 72, the ceramic column 8, the main body 81, the protrusion 82, the inner electrode 91, the pores 92, and the cutting line 93. DETAILED DESCRIPTION

[0072] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0073] However, the example embodiments can be implemented in a variety of forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted.

[0074] The words expressing positions and directions described in the present utility model are all explained by taking the drawings as examples, but they can be changed as needed, and all the changes are included in the protection scope of the present utility model.

[0075] Example 1

[0076] This embodiment provides a multilayer ceramic capacitor, such as Figure 1-4 As shown, including:

[0077] A laminate 1, a first external electrode 21 and a second external electrode 22;

[0078] The stacked body 1 has a first main surface 31 and a second main surface 32 opposite to each other in a stacking direction (Z direction), a first side surface 41 and a second side surface 42 opposite to each other in a width direction (X direction), and a first end surface 51 and a second end surface 52 opposite to each other in a length direction (Y direction), and the stacked body 1 includes a plurality of stacked dielectric material layers 6 and alternately stacked first internal electrodes 71 and second internal electrodes 72, each adjacent first internal electrode 71 and second internal electrode 72 being separated by a dielectric material layer 6;

[0079] The first outer electrode 21 is disposed on the first end surface 51 and is electrically connected to the first inner electrode 71;

[0080] The second outer electrode 22 is disposed on the second end surface 52 and is electrically connected to the second inner electrode 72;

[0081] The stacked body 1 further includes a ceramic column 8, which penetrates the first main surface 31 and the second main surface 32 in the stacking direction (Z direction) of the stacked body 1; the number of the ceramic columns 8 is 2, and the ceramic columns 8 do not penetrate the first internal electrode 71 and the second internal electrode 72; the cross-sectional shapes of the ceramic columns 8 on the first main surface 31 and the second main surface 32 are both fan-shaped; the ceramic columns 8 are exposed on the first side surface 41 and the second side surface 42, and the cross-sectional shapes of the ceramic columns 8 on the first side surface 41 and the second side surface 42 are both rectangular, and the ceramic columns 8 are located in the middle of the first side surface and / or the second side surface;

[0082] The first external electrode 21 covers the first end surface 51, part of the first main surface 31 and part of the second main surface 32, part of the first side surface 41 and part of the second side surface 42 of the stack 1; the second external electrode 22 covers the second end surface 52, part of the first main surface 31 and part of the second main surface 32, part of the first side surface 41 and part of the second side surface 42 of the stack 1.

[0083] The method for preparing the multilayer ceramic capacitor comprises:

[0084] S1. Mixing ceramic powder barium titanate, binder polyvinyl butyral and solvent ethanol to obtain a ceramic slurry;

[0085] S2. Casting the ceramic slurry into a film to obtain a ceramic green sheet;

[0086] S3. Printing a conductive paste for forming an internal electrode on a ceramic green sheet by screen printing to obtain a ceramic green sheet containing an internal electrode 91;

[0087] S4. Figure 5As shown, a pore 92 is opened in a ceramic green sheet containing an internal electrode 91, and the pore 92 is opened at a portion of the ceramic green sheet that does not contain the internal electrode 91. The ceramic green sheets are laminated and pressed, and a ceramic slurry is used as a ceramic column slurry to fill the pores to form a ceramic column green body, which is cut along a cutting line 93 to obtain a laminated green body containing a ceramic column green body.

[0088] S5. The green body of the laminate containing the ceramic column is subjected to binder removal and sintering treatment to obtain a laminate containing the ceramic column;

[0089] S6. Coating a conductive paste for forming an external electrode on the first end surface and the second end surface opposite to each other in the length direction of the stack to obtain a stack containing a first external electrode and a second external electrode;

[0090] S7. The laminate including the first external electrode and the second external electrode is subjected to end burning, and a nickel layer and a tin layer are electroplated to obtain a multilayer ceramic capacitor (MLCC);

[0091] Wherein, the material of the inner electrode is nickel, and the conductive paste used to form the inner electrode contains nickel, a binder ethyl cellulose and a solvent toluene;

[0092] The first external electrode and the second external electrode are made of copper, and the conductive paste used to form the external electrodes contains copper, a binder ethyl cellulose and a solvent toluene;

[0093] In step S4, the cross-sectional shape of the pore on the ceramic green sheet is circular, the equivalent radius of the pore is 1, and the ratio of the equivalent radius of the pore to the length of the laminated green sheet is 0.05:1;

[0094] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0095] Example 2

[0096] This embodiment provides a multilayer ceramic capacitor, such as Figure 6 As shown, Figure 6 The second outer electrode is hidden to better show the position of the ceramic column, including:

[0097] A laminate 1, a first external electrode 21 and a second external electrode 22;

[0098] The stacked body 1 has a first main surface 31 and a second main surface 32 opposite to each other in a stacking direction (Z direction), a first side surface 41 and a second side surface 42 opposite to each other in a width direction (X direction), and a first end surface 51 and a second end surface 52 opposite to each other in a length direction (Y direction), and the stacked body 1 includes a plurality of stacked dielectric material layers 6 and alternately stacked first internal electrodes 71 and second internal electrodes 72, each adjacent first internal electrode 71 and second internal electrode 72 being separated by a dielectric material layer 6;

[0099] The first outer electrode 21 is disposed on the first end surface 51 and is electrically connected to the first inner electrode 71;

[0100] The second outer electrode 22 is disposed on the second end surface 52 and is electrically connected to the second inner electrode 72;

[0101] The stacked body 1 further includes a ceramic column 8, which penetrates the first main surface 31 and the second main surface 32 in the stacking direction (Z direction) of the stacked body 1; the number of the ceramic columns 8 is 4, and the ceramic columns 8 do not penetrate the first internal electrode 71 and the second internal electrode 72; the cross-sectional shapes of the ceramic columns 8 on the first main surface 31 and the second main surface 32 are both fan-shaped, the ceramic columns 8 are exposed on the first side surface 41, the second side surface 42, the first end surface 51 and the second end surface 52, the cross-sectional shapes of the ceramic columns 8 on the first side surface 41, the second side surface 42, the first end surface 51 and the second end surface 52 are all rectangular, and the ceramic columns 8 are located at the intersection of the first / second side surface and the first / second end surface;

[0102] The cross-sectional view of the multilayer ceramic capacitor of this embodiment along the length direction is shown in FIG. Figure 4 ;

[0103] The first external electrode 21 covers the first end surface 51, part of the first main surface 31 and part of the second main surface 32, part of the first side surface 41 and part of the second side surface 42 of the stack 1; the second external electrode 22 covers the second end surface 52, part of the first main surface 31 and part of the second main surface 32, part of the first side surface 41 and part of the second side surface 42 of the stack 1.

[0104] The method for preparing the multilayer ceramic capacitor comprises:

[0105] S1. Mixing ceramic powder barium titanate, binder polyvinyl butyral and solvent ethanol to obtain a ceramic slurry;

[0106] S2. Casting the ceramic slurry into a film to obtain a ceramic green sheet;

[0107] S3. Printing a conductive paste for forming an internal electrode on a ceramic green sheet by screen printing to obtain a ceramic green sheet containing an internal electrode 91;

[0108] S4. Figure 7 As shown, a pore 92 is opened in a ceramic green sheet containing an internal electrode 91, and the pore 92 is opened at a portion of the ceramic green sheet that does not contain the internal electrode 91. The ceramic green sheets are laminated and pressed, and a ceramic slurry is used as a ceramic column slurry to fill the pores to form a ceramic column green body, which is cut along a cutting line 93 to obtain a laminated green body containing a ceramic column green body.

[0109] S5. The green body of the laminate containing the ceramic column is subjected to binder removal and sintering treatment to obtain a laminate containing the ceramic column;

[0110] S6. Coating a conductive paste for forming an external electrode on the first end surface and the second end surface opposite to each other in the length direction of the stack to obtain a stack containing a first external electrode and a second external electrode;

[0111] S7. The laminate including the first external electrode and the second external electrode is subjected to end burning, and a nickel layer and a tin layer are electroplated to obtain a multilayer ceramic capacitor (MLCC);

[0112] Wherein, the material of the inner electrode is nickel, and the conductive paste used to form the inner electrode contains nickel, a binder ethyl cellulose and a solvent toluene;

[0113] The first external electrode and the second external electrode are made of copper, and the conductive paste used to form the external electrodes contains copper, a binder ethyl cellulose and a solvent toluene;

[0114] In step S4, the cross-sectional shape of the pore on the ceramic green sheet is circular, the equivalent radius of the pore is 1, and the ratio of the equivalent radius of the pore to the length of the laminated green sheet is 0.05:1;

[0115] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0116] Example 3

[0117] This embodiment provides a multilayer ceramic capacitor, such as Figure 8 As shown, the difference between it and Example 1 is that the structure of the ceramic column 8 is different, and the rest is consistent with Example 1, specifically:

[0118] The ceramic column 8 is divided into a main body 81 and a protrusion 82, the main body 81 and the protrusion 82 are connected, the cross-sectional shape of the main body 81 on the first side surface 41 and the second side surface 42 is rectangular; the cross-sectional shape of the protrusion 82 on the first side surface 41 and the second side surface 42 is stepped, and the steps of the protrusion 82 gradually decrease from the first main surface 31 and the second main surface 32 toward the middle of the stack 1.

[0119] The method for preparing the multilayer ceramic capacitor is different from that of Example 1 only in that step S4 is different, and the rest is consistent with Example 1, specifically:

[0120] S4. Three pores with different equivalent radii are opened in the ceramic green sheet containing the inner electrode, wherein the pores are opened at the part of the ceramic green sheet not containing the inner electrode, and the ceramic green sheets are stacked and pressed in the order that the ceramic green sheet with the smaller pore equivalent radius is in the middle of the laminated green sheet, and the ceramic green sheets with the larger pore equivalent radius are in the two ends of the laminated green sheet in the stacking direction, and the size of the pore equivalent radius gradually increases from the middle of the laminated green sheet to the two ends of the laminated green sheet in the stacking direction, and the ceramic slurry is filled into the pores as the ceramic column slurry to form a ceramic column green sheet, and the ceramic column green sheet is cut to obtain a laminated green sheet containing the ceramic column green sheet;

[0121] In step S4, the cross-sectional shape of the pore on the ceramic green sheet is circular, the ratio of the three different equivalent radii of the pore is 1:0.75:0.5, the ratio of the minimum equivalent radius of the pore to the maximum equivalent radius is 0.5:1, and in descending order, the ratios of the three different equivalent radii of the pore to the length of the laminated green body are 0.025:1, 0.0375:1, and 0.05:1, respectively;

[0122] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0123] Example 4

[0124] This embodiment provides a multilayer ceramic capacitor, such as Fig. 9 As shown, the difference between it and Example 1 is that the structure of the ceramic column 8 is different, and the rest is consistent with Example 1, specifically:

[0125] The ceramic column 8 is divided into a main body 81 and a protrusion 82. The main body 81 and the protrusion 82 are connected. The cross-sectional shape of the main body 81 on the first side surface 41 and the second side surface 42 is a rectangle; the cross-sectional shape of the protrusion 82 on the first side surface 41 and the second side surface 42 is a rectangle, and there is a gap between adjacent protrusions 82.

[0126] The method for preparing the multilayer ceramic capacitor is different from that of Example 1 only in that step S4 is different, and the rest is consistent with Example 1, specifically:

[0127] S4. Two pores of different equivalent radii are opened in the ceramic green sheet containing the inner electrode, wherein the pores are opened in the portion of the ceramic green sheet not containing the inner electrode, the ceramic green sheets containing pores of different equivalent radii are alternately laminated and pressed, the ceramic slurry is filled into the pores as a ceramic column slurry to form a ceramic column green body, and the ceramic column green body is cut to obtain a laminated green body containing the ceramic column green body;

[0128] In step S4, the cross-sectional shape of the pore on the ceramic green sheet is circular, the ratio of the two different equivalent radii of the pore is 1:0.6, the ratio of the minimum equivalent radius of the pore to the maximum equivalent radius is 0.6:1, and in descending order, the ratios of the two different equivalent radii of the pore to the length of the laminated green body are 0.05:1 and 0.03:1 respectively;

[0129] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0130] Example 5

[0131] This embodiment provides a multilayer ceramic capacitor, such as Fig.10 As shown, the difference between it and Example 1 is that the structure of the ceramic column 8 is different, and the rest is consistent with Example 1, specifically:

[0132] The ceramic column 8 is divided into a main body 81 and a protrusion 82. The main body 81 and the protrusion 82 are connected. The cross-sectional shape of the main body 81 on the first side surface 41 and the second side surface 42 is rectangular; the cross-sectional shape of the protrusion 82 on the first side surface 41 and the second side surface 42 is V-shaped, and there is no gap between adjacent protrusions 82.

[0133] The method for preparing the multilayer ceramic capacitor is different from that of Example 1 only in that step S4 is different, and the rest is consistent with Example 1, specifically:

[0134] S4. Opening pores in the ceramic green sheet containing the internal electrode, the pores are opened at the part of the ceramic green sheet that does not contain the internal electrode, the equivalent radius of the pores is two or more, and the size of the pores on the single ceramic green sheet gradually decreases in the stacking direction of the laminate, laminating and pressing the ceramic green sheets, filling the pores with ceramic slurry as ceramic column slurry to form a ceramic column green body, cutting, and obtaining a laminated green body containing the ceramic column green body;

[0135] In step S4, the cross-sectional shape of the pores on the ceramic green sheet is circular, the ratio of the minimum equivalent radius to the maximum equivalent radius of the pores is 0.5:1, and the ratio of different equivalent radii of the pores to the length of the laminated green body is in the range of (0.025-0.05):1;

[0136] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0137] Example 6

[0138] This embodiment provides a multilayer ceramic capacitor, such as Fig.11 As shown, the difference from Example 1 is that the cross-sectional shapes of the ceramic column 8 on the first main surface 31 and the second main surface 32 are different, and the rest are consistent with Example 1, specifically:

[0139] The cross-sectional shapes of the ceramic column 8 on the first main surface 31 and the second main surface 32 are both trapezoidal, and the trapezoid gradually expands toward the middle of the first main surface 31 and the second main surface 32 in the width direction (X direction) of the stacked body 1 .

[0140] The method for preparing the multilayer ceramic capacitor described above is different from that of Example 1 only in that the cross-sectional shape of the pores on the ceramic green sheet in step S4 is different, and the rest is consistent with Example 1, specifically:

[0141] In step S4, the cross-sectional shape of the pore on the ceramic green sheet is a concave hexagon, the equivalent radius of the pore is 1, and the ratio of the equivalent radius of the pore to the length of the laminated green body is 0.04:1;

[0142] In step S4, the lamination pressing parameters are temperature 50° C., pressure 0.5 MPa, and time 20 min.

[0143] Comparative Example 1

[0144] This comparative example provides a multilayer ceramic capacitor, which differs from Example 1 in that the laminate does not contain ceramic columns, and its preparation method differs from Example 1 in that step S4 does not open pores in the ceramic green sheet containing the inner electrode, and the rest is consistent with Example 1.

[0145] Performance Testing

[0146] The following performance tests were performed on the multilayer ceramic capacitors of each embodiment and comparative example:

[0147] (1) Delamination cracking test

[0148] 1000 multilayer ceramic capacitors are selected for each embodiment or comparative example, and the first side surface or the second side surface of the multilayer ceramic capacitor is ground to expose the inside of the laminate, and a microscope is used to observe whether delamination and cracking occur in the exposed cross section of the laminate, and the number of multilayer ceramic capacitors with delamination and cracking is counted, and the ratio of the number of multilayer ceramic capacitors with delamination and cracking to the total number of multilayer ceramic capacitors is used as the delamination and cracking ratio of the multilayer ceramic capacitors in each embodiment or comparative example;

[0149] (2) Observe the green body of the laminate prepared in each embodiment or comparative example to see whether bubbles appear therein;

[0150] The experimental results are shown in the following table:

[0151] Table 1 Performance test results of various embodiments and comparative examples

[0152] Delamination cracking ratio (%) Are there bubbles in the laminated green body? Example 1 0.2 no Example 2 0.4 no Example 3 0 no Example 4 0 no Example 5 0 no Example 6 0.2 no Comparative Example 1 2.3 yes

[0153] As can be seen from Table 1, the ceramic column established in the utility model is an individual formed in one piece after lamination and pressing, which can strengthen the connection between the dielectric material layer, the first internal electrode and the second internal electrode, effectively prevent the delamination and cracking of the MLCC finished product, and improve the production yield and reliability of the multilayer ceramic capacitor.

[0154] The preparation method of the multilayer ceramic capacitor of the utility model promotes the discharge of bubbles generated in the lamination and pressing process by opening pores in the ceramic green sheet, prevents the bubbles from being retained in the MLCC, and effectively prevents the MLCC finished product from delamination and cracking; at the same time, the pores are opened in the ceramic green sheet to facilitate the alignment during lamination, which can further ensure the lamination accuracy and improve the production yield and reliability of the multilayer ceramic capacitor.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit the protection scope of the utility model. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. A multilayer ceramic capacitor, characterized in that: include: A stacked body (1), a first external electrode (21) and a second external electrode (22); The stacked body (1) has a first main surface (31) and a second main surface (32) opposite to each other in a stacking direction, a first side surface (41) and a second side surface (42) opposite to each other in a width direction, and a first end surface (51) and a second end surface (52) opposite to each other in a length direction. The stacked body (1) includes a plurality of stacked dielectric material layers (6) and alternately stacked first internal electrodes (71) and second internal electrodes (72), each adjacent first internal electrode (71) and second internal electrode (72) being separated by a dielectric material layer (6). The first outer electrode (21) is disposed on the first end surface (51) and is electrically connected to the first inner electrode (71); The second outer electrode (22) is disposed on the second end surface (52) and is electrically connected to the second inner electrode (72); The stacked body (1) further comprises a ceramic column (8), wherein the ceramic column (8) penetrates the first main surface (31) and the second main surface (32) in the stacking direction of the stacked body (1).

2. The multilayer ceramic capacitor according to claim 1, wherein: The ceramic column (8) does not penetrate the first internal electrode (71) and the second internal electrode (72).

3. The multilayer ceramic capacitor according to claim 1, wherein: The number of the ceramic columns (8) is ≥1.

4. The multilayer ceramic capacitor according to claim 1, wherein: The cross-sectional shape of the ceramic column (8) on the first main surface (31) and / or the second main surface (32) is circular, sector-shaped or polygonal.

5. The multilayer ceramic capacitor according to claim 1, wherein: The ceramic column (8) is exposed on the first side surface (41) and / or the second side surface (42).

6. The multilayer ceramic capacitor according to claim 1, wherein: Including any of the following (1)-(2): (1) The cross-sectional shape of the ceramic column (8) in a direction perpendicular to the first main surface (31) and the second main surface (32) is a triangle or a quadrilateral; (2) The ceramic column (8) is divided into a main body (81) and a protrusion (82), the main body (81) and the protrusion (82) are connected, and the cross-sectional shape of the main body (81) in a direction perpendicular to the first main surface (31) and the second main surface (32) is a triangle or a quadrilateral.

7. The multilayer ceramic capacitor according to claim 6, wherein: Including any one of the following (1)-(2): (1) The cross-sectional shape of the ceramic column (8) on the first side surface (41) and / or the second side surface (42) and / or the first end surface (51) and / or the second end surface (52) is a triangle or a quadrilateral; (2) The cross-sectional shape of the main body (81) on the first side surface (41) and / or the second side surface (42) and / or the first end surface (51) and / or the second end surface (52) is a triangle or a quadrilateral.

8. The multilayer ceramic capacitor according to claim 6, wherein: The cross-sectional shape of the protrusion (82) on the first side surface (41) and / or the second side surface (42) and / or the first end surface (51) and / or the second end surface (52) is at least one of a V-shape, a polygon, a curved polygon, and a stepped shape.

9. The multilayer ceramic capacitor according to claim 8, wherein: When the protrusion (82) is in a stepped shape, the steps of the protrusion (82) gradually decrease from the first main surface (31) and / or the second main surface (32) toward the middle of the stacked body (1).

10. The multilayer ceramic capacitor according to claim 5, wherein: The ceramic column (8) is located in the middle of the first side surface (41) and / or the second side surface (42).

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