Multilayer ceramic capacitor

Abstract

The utility model provides a laminated ceramic capacitor with high capacitance and excellent reliability. In a laminated ceramic capacitor (1), a laminated body (2) has an internal electrode (15) and a plurality of dummy electrodes, the plurality of dummy electrodes being electrodes that do not contribute to the formation of electrostatic capacitance and being disposed further toward a first main surface (AA) than the internal electrode (15) disposed closest to the first main surface (AA). The plurality of dummy electrodes (5) include: an outer dummy electrode (5A) disposed closest to the first main surface (AA) among the plurality of dummy electrodes; and an inner dummy electrode (5B) disposed closer to the inner electrode (15) than the outer dummy electrode (5A). The coverage rate of the outer dummy electrode (5A) is lower than the coverage rate of the internal electrode (15).

Description

Technical Field

[0001] This utility model relates to multilayer ceramic capacitors. Background Technology

[0002] Previously, miniaturization and high capacitance were required in multilayer ceramic capacitors. To achieve this, efforts are being made to thin the dielectric layer and internal electrode layer, and to multiply them. Improved reliability is also a requirement in multilayer ceramic capacitors.

[0003] Therefore, there is a known technique of arranging dummy electrodes in the upper and lower covering portions of a laminate to improve its mechanical strength and moisture resistance. Multiple dummy electrodes can be arranged in a specific configuration. In this case, the mechanical strength and other properties of the laminate can be further improved.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2023-073974 Utility Model Content

[0007] Problems to be solved by utility models

[0008] However, if the number of dummy electrodes is increased, the dummy electrodes become closer to the outer surface of the laminate. It can be assumed that near the outer surface of the laminate, the load is more easily applied to the dummy electrodes. Therefore, defects such as interlayer delamination may become more likely to occur at the dummy electrodes near the outer surface.

[0009] The purpose of this invention is to provide a multilayer ceramic capacitor with high capacitance and excellent reliability.

[0010] Technical solutions for solving the problem

[0011] To solve the above problems, the present invention provides a multilayer ceramic capacitor comprising: a multilayer body having an inner layer comprising alternatingly stacked dielectric layers and internal electrodes; an outer layer sandwiched between the inner layer in a stacking direction; a first main surface and a second main surface opposite to each other in the stacking direction; a first side surface and a second side surface opposite to each other in a width direction orthogonal to the stacking direction; and a first end surface and a second end surface opposite to each other in a length direction orthogonal to both the stacking direction and the width direction; and external electrodes, arranged in pairs on at least one of the side surfaces and the end surfaces, wherein, if the electrode is aligned with the central portion of the multilayer body in the stacking direction... The direction of observation for each of the main surfaces is set to the outer side of the stacking direction, and the direction of observation from the central portion of the stacked body from each of the main surfaces in the stacking direction is set to the inner side of the stacking direction. Then the stacked body has a plurality of dummy electrodes. The plurality of dummy electrodes are electrodes that do not contribute to the formation of electrostatic capacitance and are arranged further outward in the stacking direction than the inner electrodes. The plurality of dummy electrodes includes: an outer dummy electrode, which is arranged furthest outward in the stacking direction among the plurality of dummy electrodes; and an inner dummy electrode, which is arranged further inward in the stacking direction than the outer dummy electrode. The coverage of the outer dummy electrode is lower than the coverage of the inner electrode.

[0012] Utility Model Effect

[0013] According to this invention, a multilayer ceramic capacitor with high capacitance and excellent reliability can be provided. Attached Figure Description

[0014] Figure 1 This is a schematic perspective view of the multilayer ceramic capacitor involved in the embodiment.

[0015] Figure 2 yes Figure 1 Sectional view II-II.

[0016] Figure 3 yes Figure 2 An enlarged view of Part III.

[0017] Explanation of reference numerals in the attached figures

[0018] 1: Multilayer ceramic capacitor;

[0019] 2: Layered body;

[0020] 3: External electrode;

[0021] 5: Dummy electrodes;

[0022] 5A: External dummy electrode;

[0023] 5B: Dummy electrode on the inner side;

[0024] 14: Dielectric layer;

[0025] 15: Internal electrodes;

[0026] 16: Opposite part;

[0027] 17: Introduction section;

[0028] 18: First inclined section;

[0029] 19: Second inclined section;

[0030] 51: A fictitious opposing part;

[0031] 52: A fictitious lead-out section;

[0032] 54: The first fictitious inclined part;

[0033] 55: The second fictitious inclined part;

[0034] AA: 1st main side;

[0035] AB: 2nd main side;

[0036] BA: First side view;

[0037] BB: Second side view;

[0038] CA: First end face;

[0039] CB: Second end face. Detailed Implementation

[0040] The following is for reference Figures 1-3 The laminated ceramic capacitor 1 according to the embodiments of this utility model will be described.

[0041] (Laminated ceramic capacitor 1)

[0042] like Figure 1 As shown, the multilayer ceramic capacitor 1 is a so-called two-terminal multilayer ceramic capacitor. The multilayer ceramic capacitor 1 includes a multilayer body 2 and a pair of external electrodes 3. The multilayer body 2 is generally cuboid in shape and has six outer surfaces. The multilayer body 2 includes an inner layer 11 in which a dielectric layer 14 and an internal electrode 15 are stacked.

[0043] In this specification, the direction in which the dielectric layer 14 and the internal electrode 15 are stacked in the multilayer ceramic capacitor 1 is designated as the stacking direction T. One of the directions orthogonal to the stacking direction T is designated as the length direction L. The direction orthogonal to both the length direction L and the stacking direction T is designated as the width direction W. The direction in the stacking direction T from the center portion of the multilayer 2 towards each main surface A is designated as the "outer side of the stacking direction", and the direction in the stacking direction T from each main surface A towards the center portion of the multilayer 2 is designated as the "inner side of the stacking direction".

[0044] Of the six outer surfaces of the laminate 2, one pair of outer surfaces located on both sides along the stacking direction T are designated as the first main surface AA and the second main surface AB. Another pair of outer surfaces extending along the stacking direction T and located on both sides along the width direction W are designated as the first side surface BA and the second side surface BB. Finally, another pair of outer surfaces extending along the stacking direction T and located on both sides along the length direction L are designated as the first end surface CA and the second end surface CB. The first main surface AA and the second main surface AB are sometimes collectively referred to as "each main surface A". The first side surface BA and the second side surface BB are sometimes collectively referred to as "each side surface B". The first end surface CA and the second end surface CB are sometimes collectively referred to as "each end surface C".

[0045] In addition, a pair of external electrodes 3 are respectively disposed on each end face C. The external electrodes 3 are arranged in the length direction L.

[0046] The cross-section of the multilayer ceramic capacitor 1, parallel to both the stacking direction T and the length direction L, is designated as the "LT cross-section". Additionally, Figure 2 as well as Figure 3 The cross-section is the LT section of the central part in the width direction W of the stacked ceramic capacitor 1.

[0047] (Layered body 2)

[0048] The laminate 2 has an inner layer 11 and an outer layer 12 sandwiched between the inner layer 11 in the lamination direction T. The laminate 2 preferably has rounded corners and edges. A corner is the portion where three faces of the laminate intersect. An edge is the portion where two faces of the laminate intersect.

[0049] (Inner layer 11)

[0050] like Figure 2 as well as Figure 3 As shown, the inner layer 11 has a plurality of dielectric layers 14 and a plurality of internal electrodes 15. The dielectric layers 14 and the internal electrodes 15 are stacked alternately.

[0051] The dielectric layer 14 is formed, for example, of a dielectric ceramic with BaTiO3 as the main component. The dielectric ceramic may also contain Mn compounds, Fe compounds, Cr compounds, Co compounds, Ni compounds, etc. as secondary components.

[0052] The internal electrode 15 is formed of a metallic material such as Ni, Cu, Ag, Pd, Ag-Pd alloy, or Au. The internal electrode 15 has a plurality of first internal electrodes 15A and a plurality of second internal electrodes 15B. The first internal electrodes 15A are exposed only at the first end face CA. The second internal electrodes 15B are exposed only at the second end face CB. The first internal electrodes 15A and the second internal electrodes 15B are arranged alternately.

[0053] The first internal electrode 15A has a first opposing portion 16A and two first lead-out portions 17A. The first opposing portion 16A is the part of the first internal electrode 15A that opposes the second internal electrode 15B adjacent in the stacking direction T. The first opposing portion 16A is located at the center between each end face C. The first lead-out portion 17A is the part of the first internal electrode 15A that extends from the first opposing portion 16A toward the first end face CA. The first lead-out portion 17A is exposed at the first end face CA.

[0054] The second internal electrode 15B has a second opposing portion 16B and two second lead-out portions 17B. The second opposing portion 16B is the part of the second internal electrode 15B that opposes the adjacent first internal electrode 15A (first opposing portion 16A). The second opposing portion 16B is located at the center between each end face C. The second lead-out portion 17B is the part of the second internal electrode 15B that extends from the second opposing portion 16B toward the second end face CB. The second lead-out portion 17B is exposed at the second end face CB.

[0055] Furthermore, the first internal electrode 15A and the second internal electrode 15B are sometimes collectively referred to as "internal electrode 15". The first opposing portion 16A and the second opposing portion 16B are sometimes collectively referred to as "opposing portion 16". In addition, in the laminate 2, the internal electrode 15 closest to the first main surface AA is called the first internal electrode 15A, and the internal electrode 15 closest to the second main surface AB is called the second internal electrode 15B.

[0056] (Outer layer 12)

[0057] The outer layer 12 is formed of the same material as the dielectric layer 14 of the inner layer 11. In addition, no internal electrode 15 is disposed in the outer layer 12. Furthermore, among the two outer layer portions 12, the outer layer portion on the first main surface AA side is designated as "first outer layer portion 12A", and the outer layer portion on the second main surface AB side is designated as "second outer layer portion 12B".

[0058] (External electrode 3)

[0059] Each external electrode 3 is disposed on each end face C. Each external electrode 3 covers not only end face C, but also a portion of the main face A and a portion of the side face B. Among the external electrodes 3, the external electrode disposed on the first end face CA is designated as "first external electrode 3A", and the external electrode disposed on the second end face CB is designated as "second external electrode 3B". A first internal electrode 15A is connected to the first external electrode 3A. A second internal electrode 15B is connected to the second external electrode 3B. Each external electrode 3 includes a base electrode layer 31 formed to be in contact with the surface of the laminate 2, a first plating layer 32 disposed on the base electrode layer 31, and a second plating layer 33 disposed on the first plating layer 32.

[0060] The base electrode layer 31 is, for example, a sintered layer comprising a conductive metal such as Cu (copper) and glass. The first plating layer 32 is, for example, a Ni (nickel) plating layer. The second plating layer 33 is, for example, a Sn (tin) plating layer.

[0061] (Dummy electrode 5)

[0062] Here, the laminate 2 has a dummy electrode 5. The dummy electrode 5 is an electrode disposed inside the laminate 2 that does not form an electrostatic capacitance. The structure of the dummy electrode 5 will be described below.

[0063] The dummy electrode 5 is formed of metallic materials such as Ni, Cu, Ag, Pd, Ag-Pd alloy, and Au. The dummy electrode 5 can be formed of the same material as the internal electrode 15.

[0064] The dummy electrode 5 is positioned further outward in the stacking direction than the inner electrode 15, which is located on the outermost side of the stacking direction. In other words, the dummy electrode 5 is positioned in the outer layer 12. For example, the dummy electrode 5 is positioned in the first outer layer 12A and the second outer layer 12B, respectively.

[0065] The dummy electrode 5 is connected to the same external electrode 3 as the internal electrode 15 closest to it. Therefore, the dummy electrode 5 does not form an electrostatic capacitance. The dummy electrode 5 has: a dummy opposing portion 51, which is opposite to the opposing portion 16 closest to it; and a dummy lead-out portion 52, which extends from the dummy opposing portion 51 toward the external electrode 3 to which the internal electrode 15 closest to it is connected.

[0066] More specifically, the internal electrode 15 closest to the dummy electrode 5A disposed in the first outer layer 12A is the first internal electrode 15A. The dummy lead-out portion 52 of the dummy electrode 5 disposed in the first outer layer 12A extends towards the first end face CA. The dummy lead-out portion 52 disposed in the first outer layer 12A is connected, for example, to the first external electrode 3A. The internal electrode 15 closest to the dummy electrode 5B disposed in the second outer layer 12B is the second internal electrode 15B. The dummy lead-out portion 52 of the dummy electrode 5 disposed in the second outer layer 12B extends towards the second end face CB. The dummy lead-out portion 52 disposed in the second outer layer 12B is connected, for example, to the second external electrode 3B.

[0067] Multiple dummy electrodes 5 are disposed in each outer layer 12, specifically, two are disposed in each outer layer 12. In each outer layer 12, the multiple dummy electrodes 5 respectively include: an outer dummy electrode 5A, which is disposed on the outermost side in the stacking direction among the dummy electrodes 5; and an inner dummy electrode 5B, which is disposed on the inner side in the stacking direction than the outer dummy electrode 5A.

[0068] In each outer layer 12, the outer dummy electrode 5A and the inner dummy electrode 5B are stacked in the stacking direction T, separated by the dielectric layer 14 forming the first outer layer 12A. By stacking multiple dummy electrodes 5, the moisture resistance and mechanical strength of the laminate 2 can be improved.

[0069] However, by stacking multiple dummy electrodes 5, the outer dummy electrode 5A is particularly close to the main surface A. Therefore, it can be assumed that external loads are more likely to act on the outer dummy electrode 5A. If this is the case, deterioration problems such as interlayer peeling may easily occur at the outer dummy electrode 5A.

[0070] Therefore, the coverage of the outer dummy electrode 5A is lower than that of the inner electrode 15.

[0071] According to this structure, by reducing the coverage of the outer dummy electrode 5A, the adhesion between the outer dummy electrode 5A and the dielectric layer 14 can be improved, thus suppressing interlayer delamination at the outer dummy electrode 5A. This improves the reliability of the multilayer ceramic capacitor 1. Furthermore, by increasing the coverage of the internal electrode 15, the electrostatic capacitance can be increased.

[0072] Therefore, it is possible to provide multilayer ceramic capacitors with high capacitance and excellent reliability.

[0073] The coverage of the outer dummy electrode 5A is preferably 40% or more and less than 60%, and the coverage of the inner electrode 15 is preferably 60% or more and less than 90%. Under these conditions, the desired effect can be appropriately obtained.

[0074] The coverage of the outer dummy electrode 5A is lower than that of the inner dummy electrode 5B.

[0075] It can be assumed that the closer the distance to the main surface A, the higher the risk of interlayer delamination. However, according to this structure, by reducing the coverage of the outer dummy electrode 5A, interlayer delamination at the outer dummy electrode 5A can be appropriately suppressed. Furthermore, by increasing the coverage of the inner dummy electrode 5B, for example, it is possible to suppress the infiltration of moisture through the voids formed in the inner dummy electrode 5B, thus more reliably suppressing the reach of moisture to the inner electrode 15. As a result, the reliability of the multilayer ceramic capacitor 1 can be more appropriately improved.

[0076] The coverage of the outer dummy electrode 5A is preferably 40% or more and less than 60%, and the coverage of the inner dummy electrode 5B is preferably 60% or more and less than 90%. Under these conditions, the desired effect can be appropriately obtained.

[0077] The coverage of the inner dummy electrode 5B is lower than that of the inner electrode 15.

[0078] Based on this structure, by reducing the coverage of the inner dummy electrode 5B, the adhesion between the inner dummy electrode 5B and the dielectric layer 14 can be improved, thus more effectively suppressing interlayer delamination at the inner dummy electrode 5B. By increasing the coverage of the internal electrode 15, the desired effect can be achieved without causing a decrease in electrostatic capacitance.

[0079] The coverage of the outer dummy electrode 5A is preferably 40% or more and less than 70%, the coverage of the inner dummy electrode 5B is preferably 60% or more and less than 90%, and the coverage of the inner electrode 15 is preferably 80% or more. Preferably, the coverage of the inner dummy electrode 5B is higher than that of the outer dummy electrode 5A, and the coverage of the inner electrode 15 is higher than that of the inner dummy electrode 5B. In these cases, the desired effect can be appropriately obtained.

[0080] The coverage of the dummy lead-out section 52 is lower than that of the lead-out section 17.

[0081] It can be considered that interlayer delamination is particularly prone to occur at the dummy lead 52 in the laminate 2. Therefore, by reducing the coverage of the dummy lead 52, the occurrence of interlayer delamination at the dummy lead 52 can be effectively suppressed. By increasing the coverage of the lead 17, it becomes easier to increase the overall coverage of the internal electrode 15, thereby increasing the electrostatic capacitance.

[0082] In the internal electrode 15, the coverage of the lead-out portion 17 is lower than that of the opposing portion 16.

[0083] It can be considered that interlayer delamination is prone to occur at the lead-out portion 17 in the internal electrode 15. By reducing the coverage of the lead-out portion 17, the occurrence of interlayer delamination at the internal electrode 15 can be suppressed. Furthermore, by increasing the coverage of the counter portion 16, the electrostatic capacitance can be increased.

[0084] like Figure 3 As shown, each dummy lead-out portion 52 (dummy lead-out portion 52A, dummy lead-out portion 52B) has: a first dummy inclined portion 54 (first dummy inclined portion 54A, first dummy inclined portion 54B), which extends from the dummy opposing portion 51 (dummy opposing portion 51A, dummy lead-out portion 51B) and is inclined inward in the stacking direction from the dummy opposing portion 51 side toward the side separated from the dummy opposing portion 51; and a second dummy inclined portion 55 (second dummy inclined portion 55A, second dummy inclined portion 55B), which extends from the first dummy inclined portion 54 toward the side separated from the dummy opposing portion 51 and is inclined inward in the stacking direction at a gentler inclination than the first dummy inclined portion 54 from the dummy opposing portion 51 side toward the side separated from the dummy opposing portion 51. In addition, an "A" is added to the end of the reference numerals for each part of the outer dummy electrode 5A, and a "B" is added to the end of the reference numerals for each part of the inner dummy electrode 5B.

[0085] The coverage of the first dummy inclined section 54 is lower than that of the second dummy inclined section 55.

[0086] The dummy lead-out portion 52 is sometimes significantly inclined near the dummy opposing portion 51. It can be considered that interlaminar peeling is prone to occur in this inclined portion (first dummy inclined portion 54). Therefore, by making the coverage particularly low at the first dummy inclined portion 54 in the dummy lead-out portion 52, interlaminar peeling at the dummy lead-out portion 52 can be effectively suppressed.

[0087] Furthermore, the lead-out portion 17 of the internal electrode 15 has: a first inclined portion 18, which extends from the opposing portion 16 and is inclined inward in the stacking direction from the opposing portion 16 side toward the side separated from the opposing portion 16; and a second inclined portion 19, which extends from the first inclined portion 18 toward the side separated from the opposing portion 16 and is inclined inward in the stacking direction at a gentler inclination than the first inclined portion 18 from the opposing portion 16 side toward the side separated from the opposing portion 16.

[0088] The dimension of the first inclined portion 18 in the inclined direction is smaller than the dimension of the first dummy inclined portion 54 in the inclined direction. Specifically, the dimension of the first inclined portion 18 in the inclined direction is smaller than the dimension of the first dummy inclined portion 54B formed on the inner dummy electrode 5B in the inclined direction, and smaller than the dimension of the first dummy inclined portion 54A formed on the outer dummy electrode 5A in the inclined direction.

[0089] Lead-out portion 17 and dummy lead-out portion 52 are sometimes significantly inclined near opposing portion 16 and dummy opposing portion 51. It can be considered that interlaminar peeling is more likely to occur in the steeply inclined portions (first inclined portion 18, first dummy inclined portion 54) compared to other portions. Furthermore, it can be considered that the internal electrode 15 requires more effort to suppress interlaminar peeling compared to the dummy electrode 5. However, according to this structure, by reducing the size of the first inclined portion 18, interlaminar peeling at the internal electrode 15 can be suppressed. Additionally, as described above, the coverage of the dummy electrode 5 can be made lower than that of the internal electrode 15. Therefore, even when the size of the first dummy inclined portion 54 is relatively large, interlaminar peeling at the dummy electrode 5 can be sufficiently suppressed by reducing the coverage of the first dummy inclined portion 54.

[0090] The dimension of the first dummy inclined portion 54B formed on the inner dummy electrode 5B in the inclined direction is smaller than the dimension of the first dummy inclined portion 54A formed on the outer dummy electrode 5A in the inclined direction.

[0091] Therefore, interlaminar peeling can be suppressed at the inner dummy electrode 5B, which is closer to the inner electrode 15 among the multiple dummy electrodes 5. Thus, at the inner dummy electrode 5B, interlaminar peeling can be suppressed while ensuring sufficient coverage.

[0092] In addition, Figure 3 In this diagram, the dimension of the first inclined portion 18 in the inclined direction is shown as d1, the dimension of the first dummy inclined portion 54B formed on the inner dummy electrode 5B in the inclined direction is shown as d2, and the dimension of the first dummy inclined portion 54A formed on the outer dummy electrode 5A in the inclined direction is shown as d3. The second dummy inclined portion 55 formed on the outer dummy electrode 5A is shown as the second dummy inclined portion 55A, and the second dummy inclined portion 55 formed on the inner dummy electrode 5B is shown as the second dummy inclined portion 55B.

[0093] (Measurement Method)

[0094] Next, the methods for determining each value will be explained.

[0095] Electrode coverage is the proportion of the metal portion within the electrode. Electrode coverage can be measured, for example, as so-called line coverage.

[0096] When measuring the coverage (line coverage) of the electrodes, the laminate is ground so that the LT section passing through the center of the width direction W of the laminated ceramic capacitor 1 (e.g., Figure 2 The cross-section of the electrode is exposed. Next, the exposed cross-section is observed using a scanning electron microscope (SEM) or the like. In each region of the electrode, the length L dimension (denoted as "length La") including the gaps of the electrode and the length L dimension (denoted as "length Lb") of the actual electrode without the gaps are measured. The coverage of each region of the electrode is calculated using the following formula (1).

[0097] Coverage (%) = (Length Lb / Length La) × 100 … (1)

[0098] While measuring the dimensions of the electrodes, the laminate is ground to expose a given cross-section (e.g., a reference cross-section) at the center of the LT cross-section in the width direction W of the laminate 2. The exposed cross-section is then observed using a scanning electron microscope, and various dimensions are measured.

[0099] In addition, the coverage and size of the internal electrode 15 are set as the average of the measured values ​​among the multiple internal electrodes 15.

[0100] (Manufacturing method of multilayer ceramic capacitor 1)

[0101] Next, the manufacturing method of the multilayer ceramic capacitor 1 according to the embodiment will be described. The manufacturing method of the multilayer ceramic capacitor 1 according to this embodiment is not limited as long as the above-described requirements are met. However, a preferred manufacturing method includes the following steps. Each step will be described in detail below.

[0102] (Internal electrode pattern formation process)

[0103] First, a ceramic green sheet is prepared by molding the ceramic slurry into a sheet shape. On the ceramic green sheet, a pattern for the internal electrode 15 is printed using conductive paste. This yields a ceramic green sheet with the internal electrode 15 (hereinafter referred to as a "ceramic green sheet for the inner layer"). Furthermore, a pattern for the dummy electrode 5 is printed on the ceramic green sheet using conductive paste. This yields a ceramic green sheet with the dummy electrode 5 (hereinafter referred to as a "ceramic green sheet for dummy electrode lamination"). The patterns for the internal electrode 15 and the dummy electrode 5 are formed, for example, by screen printing, gravure printing, letterpress printing, or similar methods.

[0104] When the printing method is screen printing, the electrode coverage can be adjusted by changing the depth of the mesh openings for each electrode and area. In areas where higher coverage is desired, the mesh opening depth is set deeper, and in areas where lower coverage is desired, the mesh opening depth is set shallower. Furthermore, when the printing method is gravure printing, the electrode coverage can be adjusted by changing the area and volume of the gravure plate openings for each electrode and area. The adjustment of the opening area and volume can, for example, be performed using laser-based printing.

[0105] The degree of electrode tilt can be adjusted, for example, by adjusting the thickness of the ceramic green sheet and the conductive paste, or by adjusting the pressing conditions when pressing the master block described later by isostatic pressing.

[0106] (Layering process)

[0107] Next, ceramic green sheets are used for the inner layer. By using ceramic green sheets for the inner layer, the internal electrode patterns are staggered by half a spacing in the length direction L between adjacent sheets.

[0108] Next, a dummy electrode ceramic green sheet is placed on top of the uppermost layer of the inner layer ceramic green sheets, which are stacked with each layer staggered by half a spacing. The dummy electrode ceramic green sheet is arranged such that, when viewed from the stacking direction T, the pattern of the conductive paste on the uppermost ceramic green sheet and the pattern of the conductive paste on the dummy electrode ceramic green sheet overlap. For example, two dummy electrode ceramic green sheets are stacked. Then, a ceramic green sheet without conductive paste is stacked on top of it as the outer layer ceramic green sheet.

[0109] Similarly, below the bottommost layer of the inner layer ceramic green sheets stacked at half-spaced intervals, a ceramic green sheet for dummy electrode stacks is placed. The ceramic green sheet for dummy electrode stacks is arranged such that, viewed from the stacking direction T, the pattern of the conductive paste on the bottommost ceramic green sheet and the pattern of the conductive paste on the ceramic green sheet for dummy electrode stacks overlap. For example, two layers of ceramic green sheets for dummy electrode stacks are stacked. Furthermore, a ceramic green sheet without conductive paste is stacked below it as the ceramic green sheet for the outer layer.

[0110] The outer ceramic sheet is hot-pressed onto the inner ceramic sheet. This yields the master block.

[0111] Furthermore, the outer layer 12 is composed of ceramic green sheets for stacking dummy electrodes and ceramic green sheets without conductive paste printed on them. In addition, in each outer layer 12, the number of ceramic green sheets for stacking dummy electrodes is not limited to two layers, but can be three or more layers. The number of ceramic green sheets for stacking outer layers without conductive paste printed on them can be one layer or two or more layers.

[0112] (Main block cutting process)

[0113] Next, the parent block is divided along a cutting line corresponding to the dimensions of the laminate. The parent block is cut, for example, in the length direction L and the width direction W. This yields multiple cuboid blocks (called "laminated pieces"). Furthermore, preferably, the laminated pieces are rounded at the corners and edges, for example, by tumbling.

[0114] (Laminated body firing process)

[0115] Next, the stacked sheets are heated in a nitrogen atmosphere at a given firing temperature for a given time. This yields stack 2.

[0116] (External electrode formation process)

[0117] Next, external electrodes 3 are formed on each end face C of the laminate 2. Each external electrode 3 is formed to cover not only the end face C but also a portion of the end face C side of the main face A and the side face B.

[0118] (External electrode welding process)

[0119] Next, the laminate 2 forming the external electrode 3 is heated in a nitrogen atmosphere at a given firing temperature for a given time. Thus, the external electrode 3 is fired onto the laminate 2.

[0120] Based on the above, we can obtain Figure 1 The stacked ceramic capacitor 1 shown.

[0121] (Effects related to the implementation method)

[0122] According to this embodiment, the following effects can be obtained.

[0123] According to this embodiment, the coverage of the outer dummy electrode 5A is lower than the coverage of the inner electrode 15.

[0124] According to this structure, by reducing the coverage of the outer dummy electrode 5A, the adhesion between the outer dummy electrode 5A and the dielectric layer 14 can be improved, thus suppressing interlayer delamination at the outer dummy electrode 5A. This improves the reliability of the multilayer ceramic capacitor 1. Furthermore, by increasing the coverage of the internal electrode 15, the electrostatic capacitance can be increased.

[0125] Therefore, it is possible to provide multilayer ceramic capacitors with high capacitance and excellent reliability.

[0126] According to this embodiment, the coverage of the outer dummy electrode 5A is lower than the coverage of the inner dummy electrode 5B.

[0127] It can be assumed that the closer the distance to the main surface A, the higher the risk of interlayer delamination. However, according to this structure, by reducing the coverage of the outer dummy electrode 5A, interlayer delamination at the outer dummy electrode 5A can be appropriately suppressed. Furthermore, by increasing the coverage of the inner dummy electrode 5B, for example, the reach of moisture to the inner electrode 15 can be more reliably suppressed. Thus, the reliability of the multilayer ceramic capacitor 1 can be more appropriately improved.

[0128] According to this embodiment, the coverage of the inner dummy electrode 5B is lower than the coverage of the inner electrode 15.

[0129] Based on this structure, by reducing the coverage of the inner dummy electrode 5B, the adhesion between the inner dummy electrode 5B and the dielectric layer 14 can be improved, thus more effectively suppressing interlayer delamination at the inner dummy electrode 5B. By increasing the coverage of the internal electrode 15, the desired effect can be achieved without causing a decrease in electrostatic capacitance.

[0130] According to this embodiment, the coverage of the outer dummy electrode 5A is preferably 40% or more and less than 60%, and the coverage of the inner electrode 15 is preferably 60% or more and less than 90%. In this case, the desired effect can be appropriately obtained.

[0131] According to this embodiment, the coverage of the outer dummy electrode 5A is preferably 40% or more and less than 60%, and the coverage of the inner dummy electrode 5B is preferably 60% or more and less than 90%. In this case, the desired effect can be appropriately obtained.

[0132] According to this embodiment, the coverage of the dummy lead-out portion 52 is lower than the coverage of the lead-out portion 17.

[0133] It can be considered that interlayer delamination is particularly prone to occur at the dummy lead 52 in the laminate 2. Therefore, by reducing the coverage of the dummy lead 52, the occurrence of interlayer delamination at the dummy lead 52 can be effectively suppressed. By increasing the coverage of the lead 17, the coverage of the internal electrode 15 can be increased, thereby increasing the electrostatic capacitance.

[0134] According to this embodiment, in the internal electrode 15, the coverage of the lead-out portion 17 is lower than the coverage of the opposing portion 16.

[0135] It can be considered that interlayer delamination is prone to occur at the lead-out portion 17 in the internal electrode 15. By reducing the coverage of the lead-out portion 17, the occurrence of interlayer delamination at the internal electrode 15 can be suppressed. Furthermore, by increasing the coverage of the counter portion 16, the electrostatic capacitance can be increased.

[0136] According to this embodiment, the coverage of the first dummy tilted portion 54 is lower than the coverage of the second dummy tilted portion 55.

[0137] The dummy lead-out portion 52 is sometimes significantly inclined near the dummy opposing portion 51. It can be considered that interlaminar peeling is prone to occur in this inclined portion (first dummy inclined portion 54). Therefore, by making the coverage particularly low at the first dummy inclined portion 54 in the dummy lead-out portion 52, interlaminar peeling at the dummy lead-out portion 52 can be effectively suppressed.

[0138] According to this embodiment, the dimension of the first inclined portion 18 in the inclined direction is smaller than the dimension of the first dummy inclined portion 54 in the inclined direction. Specifically, the dimension of the first inclined portion 18 in the inclined direction is smaller than the dimension of the first dummy inclined portion 54B formed on the inner dummy electrode 5B in the inclined direction, and smaller than the dimension of the first dummy inclined portion 54A formed on the outer dummy electrode 5A in the inclined direction.

[0139] Lead-out portion 17 and dummy lead-out portion 52 are sometimes significantly inclined near opposing portion 16 and dummy opposing portion 51. It can be considered that interlaminar peeling is more likely to occur in the steeply inclined portions (first inclined portion 18, first dummy inclined portion 54) compared to other portions. Furthermore, it can be considered that the internal electrode 15 requires more effort to suppress interlaminar peeling compared to the dummy electrode 5. However, according to this structure, by reducing the size of the first inclined portion 18, interlaminar peeling at the internal electrode 15 can be suppressed. Additionally, as described above, the coverage of the dummy electrode 5 can be made lower than that of the internal electrode 15. Therefore, even when the size of the first dummy inclined portion 54 is relatively large, interlaminar peeling at the dummy electrode 5 can be sufficiently suppressed by reducing the coverage of the first dummy inclined portion 54.

[0140] According to this embodiment, the dimension of the first dummy tilted portion 54B formed on the inner dummy electrode 5B in the tilting direction is smaller than the dimension of the first dummy tilted portion 54A formed on the outer dummy electrode 5A in the tilting direction.

[0141] Therefore, interlaminar peeling can be suppressed at the inner dummy electrode 5B, which is closer to the inner electrode 15 among the multiple dummy electrodes 5. Thus, at the inner dummy electrode 5B, interlaminar peeling can be suppressed while ensuring sufficient coverage.

[0142] The embodiments of this utility model have been described above, but this utility model is not limited to the above embodiments and various changes and modifications can be made.

[0143] In the above embodiment, the internal electrode 15 located on the side closest to the first main surface AA is the first internal electrode 15A, and the internal electrode 15 located on the side closest to the second main surface AB is the second internal electrode 15B, but this is not a limitation. For example, the internal electrode 15 located on the side closest to the first main surface AA can be designated as the second internal electrode 15B, and the internal electrode 15 located on the side closest to the second main surface AB can be designated as the first internal electrode 15A. In this case, the internal structure of the laminate 2 becomes substantially the same as the structure obtained by flipping the internal structure of the laminate 2 in the above embodiment along the length direction L.

[0144] In the above embodiment, each dummy electrode 5 is connected to the external electrode 3 connected to the internal electrode 15 closest to that dummy electrode 5, but this is not a limitation. The dummy electrode 5 may also be configured not to be connected to any of the external electrodes 3.

[0145] In the above embodiment, two dummy electrodes 5 are disposed in each outer layer 12. Although two are disposed in each outer layer 12, this is not a limitation. Three or more dummy electrodes 5 may also be disposed in each outer layer 12. In this case, in each outer layer 12, the plurality of dummy electrodes 5 become one outer dummy electrode 5A and two or more inner dummy electrodes 5B. Moreover, preferably, among the plurality of inner dummy electrodes 5B disposed in one outer layer 12, the coverage of the inner dummy electrode 5B located further outward in the stacking direction is lower than that of the inner dummy electrode 5B located further inward in the stacking direction.

[0146] In this case, it can be considered that among the multiple inner dummy electrodes 5B, the inner dummy electrode 5B located further outward in the stacking direction has a higher risk of peeling. Therefore, peeling of the inner dummy electrode 5B, which is more prone to peeling, can be appropriately suppressed. It can also be considered that the inner dummy electrode 5B located further inward in the stacking direction has a lower risk of peeling. Therefore, the reliability of the multilayer ceramic capacitor 1 can be improved by increasing the coverage of the inner dummy electrode 5B with a lower risk of peeling.

[0147] In the above embodiment, the dummy electrode 5 is disposed on the outer layer 12 on the first main surface AA side and the outer layer 12 on the second main surface AB side, but the dummy electrode 5 can be disposed on at least one of the outer layer 12.

[0148] In addition, this utility model includes the following combinations.

[0149] <1>

[0150] A multilayer ceramic capacitor comprises: a multilayer body having an inner layer portion including alternately stacked dielectric layers and internal electrodes; an outer layer portion sandwiched between the inner layer portion in a stacking direction; a first main surface and a second main surface opposite to each other in the stacking direction; a first side surface and a second side surface opposite to each other in a width direction orthogonal to the stacking direction; and a first end surface and a second end surface opposite to each other in a length direction orthogonal to both the stacking direction and the width direction; and external electrodes, arranged in pairs on at least one of the side surfaces and the end surfaces, wherein, if the electrode is moved from the center of the multilayer body in the stacking direction to each of the main surfaces... If the direction of observation is set to the outer side of the stacking direction, and the direction of observation from the central portion of the stacked body from each of the main faces in the stacking direction is set to the inner side of the stacking direction, then the stacked body has a plurality of dummy electrodes. The plurality of dummy electrodes are electrodes that do not contribute to the formation of electrostatic capacitance and are arranged further outward in the stacking direction than the inner electrodes. The plurality of dummy electrodes includes: an outer dummy electrode, which is arranged furthest outward in the stacking direction among the plurality of dummy electrodes; and an inner dummy electrode, which is arranged further inward in the stacking direction than the outer dummy electrode. The coverage of the outer dummy electrode is lower than the coverage of the inner electrode.

[0151] <2>

[0152] according to <1> The aforementioned multilayer ceramic capacitor, wherein,

[0153] The coverage of the outer dummy electrode is lower than that of the inner dummy electrode.

[0154] <3>

[0155] according to <1> or <2> The aforementioned multilayer ceramic capacitor, wherein,

[0156] The coverage of the inner dummy electrode is lower than that of the internal electrode.

[0157] <4>

[0158] according to <1> ~ <3> The multilayer ceramic capacitor described in any one of the following embodiments, wherein,

[0159] The coverage of the outer dummy electrode is more than 40% but less than 60%, and the coverage of the inner electrode is more than 60% but less than 90%.

[0160] <5>

[0161] according to <2> ~ <4> The multilayer ceramic capacitor described in any one of the following, wherein,

[0162] The coverage of the outer dummy electrode is more than 40% but less than 60%, and the coverage of the inner dummy electrode is more than 60% but less than 90%.

[0163] <6>

[0164] according to <1> ~ <5> The multilayer ceramic capacitor described in any one of the following, wherein,

[0165] The internal electrode has: an opposing portion, which is opposite to the internal electrode adjacent in the stacking direction; and a lead-out portion, which extends from the opposing portion and is connected to the external electrode. Each dummy electrode has: a dummy opposing portion, which overlaps with the opposing portion closest to the first main surface in the stacking direction; and a dummy lead-out portion, which extends from the dummy opposing portion to the external electrode side connected to the lead-out portion furthest outward in the stacking direction. The coverage of the dummy lead-out portion is lower than the coverage of the lead-out portion.

[0166] <7>

[0167] according to <6> The aforementioned multilayer ceramic capacitor, wherein,

[0168] The coverage of the lead-out portion is lower than that of the opposing portion.

[0169] <8>

[0170] according to <6> or <7> The aforementioned multilayer ceramic capacitor, wherein,

[0171] The dummy lead-out portion has: a first dummy inclined portion extending from the dummy opposing portion and inclined inward in the stacking direction from the dummy opposing portion side toward the side separated from the dummy opposing portion; and a second dummy inclined portion extending from the first dummy inclined portion toward the side separated from the dummy opposing portion and inclined inward in the stacking direction at a gentler inclination than the first dummy inclined portion from the dummy opposing portion side toward the side separated from the dummy opposing portion, wherein the coverage of the first dummy inclined portion is lower than the coverage of the second dummy inclined portion.

[0172] <9>

[0173] according to <8> The aforementioned multilayer ceramic capacitor, wherein,

[0174] The lead-out portion has: a first inclined portion extending from the opposing portion and inclined inward in the stacking direction from the opposing portion side toward the side separated from the opposing portion; and a second inclined portion extending from the first inclined portion toward the side separated from the opposing portion and inclined inward in the stacking direction at a gentler inclination than the first inclined portion from the opposing portion side toward the side separated from the opposing portion, wherein the dimension of the first inclined portion in the inclined direction is smaller than the dimension of the first dummy inclined portion in the inclined direction.

[0175] <10>

[0176] according to <8> or <9> The aforementioned multilayer ceramic capacitor, wherein,

[0177] The dimension of the first dummy inclined portion formed on the inner dummy electrode in the inclined direction is smaller than the dimension of the first dummy inclined portion formed on the outer dummy electrode in the inclined direction.

Claims

1. A multilayer ceramic capacitor, characterized in that, have: A laminate includes an inner layer comprising alternating layers of dielectric layers and internal electrodes, an outer layer sandwiched between the inner layer in a stacking direction, a first main surface and a second main surface opposite to each other in the stacking direction, a first side surface and a second side surface opposite to each other in a width direction orthogonal to the stacking direction, and a first end surface and a second end surface opposite to each other in a length direction orthogonal to both the stacking direction and the width direction; and External electrodes are arranged in pairs on at least one of the said side faces and said end faces. in, If the direction of observation from the center of the stacked body along the stacking direction to each of the main faces is defined as the outer side of the stacking direction, and the direction of observation from each of the main faces to the center of the stacked body along the stacking direction is defined as the inner side of the stacking direction, then The laminate has a plurality of dummy electrodes, which are electrodes that do not contribute to the formation of electrostatic capacitance, and are disposed on the outer side of the laminate direction than the inner electrodes. The plurality of dummy electrodes includes: an outer dummy electrode, disposed on the outermost side of the plurality of dummy electrodes in the stacking direction; and an inner dummy electrode, disposed on the inner side of the plurality of dummy electrodes in the stacking direction than the outer dummy electrode. The coverage of the outer dummy electrode is lower than that of the inner electrode.

2. The multilayer ceramic capacitor according to claim 1, characterized in that, The coverage of the outer dummy electrode is lower than that of the inner dummy electrode.

3. The multilayer ceramic capacitor according to claim 2, characterized in that, The coverage of the inner dummy electrode is lower than that of the internal electrode.

4. The multilayer ceramic capacitor according to any one of claims 1 to 3, characterized in that, The coverage of the outer dummy electrode is more than 40% but less than 60%, and the coverage of the inner electrode is more than 60% but less than 90%.

5. The multilayer ceramic capacitor according to claim 2 or 3, characterized in that, The coverage of the outer dummy electrode is more than 40% but less than 60%, and the coverage of the inner dummy electrode is more than 60% but less than 90%.

6. The multilayer ceramic capacitor according to any one of claims 1 to 3, characterized in that, The internal electrode has: an opposing portion, which opposes the internal electrode adjacent in the stacking direction; and a lead-out portion, which extends from the opposing portion and is connected to the external electrode. Each of the dummy electrodes has: a dummy opposing portion that overlaps with the opposing portion closest to the first main surface in the stacking direction; and a dummy lead-out portion that extends from the dummy opposing portion to the external electrode side connected to the lead-out portion furthest outward in the stacking direction. The coverage of the dummy lead-out section is lower than the coverage of the lead-out section.

7. The multilayer ceramic capacitor according to claim 6, characterized in that, The coverage of the lead-out portion is lower than that of the opposing portion.

8. The multilayer ceramic capacitor according to claim 6, characterized in that, The dummy lead-out portion has: a first dummy inclined portion extending from the dummy opposing portion and inclined inward in the stacking direction from the dummy opposing portion side toward the side separated from the dummy opposing portion; and a second dummy inclined portion extending from the first dummy inclined portion toward the side separated from the dummy opposing portion and inclined inward in the stacking direction at a gentler inclination than the first dummy inclined portion from the dummy opposing portion side toward the side separated from the dummy opposing portion. The coverage of the first dummy tilted portion is lower than that of the second dummy tilted portion.

9. The multilayer ceramic capacitor according to claim 8, characterized in that, The lead-out portion has: a first inclined portion extending from the opposing portion and inclined inward in the stacking direction from the opposing portion side toward the side separated from the opposing portion; and a second inclined portion extending from the first inclined portion toward the side separated from the opposing portion and inclined inward in the stacking direction at a gentler inclination than the first inclined portion from the opposing portion side toward the side separated from the opposing portion. The dimension of the first inclined portion in the inclined direction is smaller than the dimension of the first dummy inclined portion in the inclined direction.

10. The multilayer ceramic capacitor according to claim 8, characterized in that, The dimension of the first dummy inclined portion formed on the inner dummy electrode in the inclined direction is smaller than the dimension of the first dummy inclined portion formed on the outer dummy electrode in the inclined direction.

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