Multilayer ceramic capacitor

Abstract

This invention provides a multilayer ceramic capacitor capable of suppressing energy loss in high-frequency regions, achieving ESL reduction, and suppressing internal structural defects. The dimension of the multilayer (2) in the width direction (W) is larger than the dimension in the length direction (L). Multiple internal electrodes (15) have multiple internal electrode groups (16), which are groups of internal electrodes (15) that are continuously adjacent in the stacking direction (T) and exposed on the same end face (C). Each internal electrode group (16) has: an inner internal electrode (151), which is the internal electrode (15) closest to the center of the multilayer (2) in the stacking direction (T); and an inner internal electrode (151), which is the internal electrode (15) closest to the surface of the multilayer (2). The inner inner electrode (151) of the inner electrode group (16) closest to the surface of the stack (2) among the multiple inner electrode groups (16) has an inner curved portion (151a), which is a portion that is curved into a central convex shape toward the stacking direction (T) of the stack (2).

Description

Technical Field

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

[0002] Conventional multilayer ceramic capacitors have existed that comprise: a multilayer body having multiple dielectric layers and multiple internal electrodes alternately stacked; and external electrodes disposed on both ends of the multilayer body. In recent years, multilayer ceramic capacitors with excellent high-frequency characteristics have been developed (e.g., Patent Document 1).

[0003] In the multilayer ceramic capacitor of Patent Document 1, an internal electrode group consisting of internal electrodes adjacent to each other in the stacking direction is provided. This results in a high Q value in the high-frequency region. In high-frequency circuits using multilayer ceramic capacitors with high Q values, energy loss within the high-frequency circuit can be suppressed. Furthermore, in multilayer ceramic capacitors where the width dimension is larger than the length dimension, compared to conventional multilayer ceramic capacitors, the distance between the external electrodes can be shortened or the width dimension of the external electrodes can be increased, thereby reducing ESL.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-9817 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, in the multilayer ceramic capacitor of Patent Document 1, it becomes difficult to ensure a tight seal between the internal electrodes and the dielectric layer around the internal electrode assembly. Consequently, internal structural defects such as cracks and delamination may occur, originating between the internal electrodes and the dielectric layer. In particular, in multilayer ceramic capacitors where the width dimension is larger than the length dimension, there is a tendency for the area of ​​the gap from the lengthwise end of the first internal electrode to the second end face and the area of ​​the gap from the lengthwise end of the second internal electrode to the first end face to increase, sometimes making it easier for internal structural defects to originate between the internal electrodes and the dielectric layer.

[0009] The purpose of this invention is to provide a multilayer ceramic capacitor that can suppress energy loss in the high-frequency region, reduce ESL, and suppress internal structural defects.

[0010] Technical solutions for solving the problem

[0011] To address the aforementioned problems, the multilayer ceramic capacitor of the present invention comprises: a multilayer body having an inner layer comprising a plurality of alternately stacked dielectric layers and a plurality of internal electrodes, a pair of main surfaces facing each other in a stacking direction, a pair of side surfaces facing each other in a width direction orthogonal to the stacking direction, and a pair of end surfaces facing each other in a length direction orthogonal to both the stacking direction and the width direction; and external electrodes disposed on the end surfaces and connected to the internal electrodes, wherein the dimension of the multilayer body in the width direction is larger than the dimension of the multilayer body in the length direction, and the plurality of internal electrodes have a plurality of internal electrode groups, wherein the internal electrode groups are contained in a continuous manner in the stacking direction. The internal electrode groups are adjacent to each other and exposed on the same end face. Each internal electrode group has an inner internal electrode and an outer internal electrode. The inner internal electrode is the internal electrode of the internal electrode group that is closest to the center of the stacking direction of the laminate. The outer internal electrode is the internal electrode of the internal electrode group that is closest to the surface of the laminate. The inner internal electrode of the internal electrode group that is closest to the surface of the laminate has an inner curved portion. The inner curved portion is a portion that is curved into a shape that convexes toward the center of the stacking direction of the laminate.

[0012] Invention Effects

[0013] According to the present invention, a multilayer ceramic capacitor is provided that can suppress energy loss in the high-frequency region, achieve ESL reduction, and suppress internal structural defects. 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 1 Sectional view III-III.

[0017] Figure 4 yes Figure 2 Enlarged view of part IV. Detailed Implementation

[0018] The following is for reference Figures 1-4 The multilayer ceramic capacitor 1 according to an embodiment of the present invention will be described.

[0019] (Laminated ceramic capacitor 1)

[0020] 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 portion 11 in which a dielectric layer 14 and internal electrodes 15 are stacked.

[0021] In this specification, the stacking direction of the dielectric layer 14 and the internal electrode 15 in the multilayer ceramic capacitor 1 is defined as the stacking direction T. One of the directions orthogonal to the stacking direction T is defined as the length direction L. The direction orthogonal to both the length direction L and the stacking direction T is defined as the width direction W.

[0022] One pair of outer surfaces of the six outer surfaces of the laminate 2, which are located on both sides in the stacking direction T, are designated as the first main surface AA and the second main surface AB. Another pair of outer surfaces that extend in the stacking direction T and are located on both sides in the width direction W are designated as the first side surface BA and the second side surface BB. Another pair of outer surfaces that extend in the stacking direction T and are located on both sides in the length direction L are designated as the first end surface CA and the second end surface CB.

[0023] The first principal surface AA and the second principal surface AB are sometimes collectively referred to as "each principal 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".

[0024] The section parallel to the stacking direction T and the length direction L is designated as the "LT section". Figure 2 The cross-section is the LT section passing through the center of the width direction W of the multilayer ceramic capacitor 1. The cross-section parallel to the stacking direction T and the width direction W is designated as the "WT section". Figure 3 The cross-section is the WT section passing through the center of the length direction L of the stacked ceramic capacitor 1.

[0025] (Layered body 2)

[0026] 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 portion where the three outer surfaces of the laminate 2 intersect is designated as a "corner". The portion where the two outer surfaces of the laminate 2 intersect is designated as an "edge". Preferably, the corners and edges of the laminate 2 have rounded corners.

[0027] The dimension in the width direction W of the laminate 2 is larger than the dimension in the length direction L of the laminate 2. The dimension in the length direction L of the laminate 2 is, for example, 0.2 mm or more and 0.6 mm or less. The dimension in the width direction W of the laminate 2 is, for example, 0.4 mm or more and 1.0 mm or less. The dimension in the stacking direction T of the laminate 2 is, for example, 0.1 mm or more and 0.9 mm or less. The external dimensions of the laminated ceramic capacitor 1 can be measured using a micrometer.

[0028] (Inner layer 11)

[0029] 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.

[0030] The dielectric layer 14 uses a ceramic material containing at least one of Ca, Sr, Zr, and Ti as its main component.

[0031] For example, dielectric layer 14 uses a ceramic material as its main component, which contains Ca and Zr and has a perovskite structure represented by the general formula ABO3. Dielectric layer 14, for example, has the following composition: (Ca...) 1-x-y Sr x Ba y )m(Zr 1-z-α Ti z Hf α The term O3 represents x being 0 or higher and 1 or lower, y being 0 or higher and 0.4 or lower, m being 1.0 or higher and 1.1 or lower, z being 0 or higher and 0.2 or lower, and α being 0 or higher and 0.3 or lower. The dielectric layer 14 is, for example, CaZrO3 (calcium zirconate). The main component of the ceramic material forming the dielectric layer 14 may also include all of Ca, Zr, and Ti. For example, the dielectric layer 14 may also be Ca(Zr0.9Ti0.1)O3, where Ca(Zr0.9Ti0.1)O3 is a substance in which ZrO3 or a portion of Zr is replaced by Ti.

[0032] Furthermore, the dielectric layer 14 is not limited to a ceramic material containing Ca and Zr and having a perovskite structure represented by the general formula ABO3 as the main component. The dielectric layer 14 can also be, for example, TiO2 (titanium oxide).

[0033] The dielectric layer 14 is preferably any of the following: having a dielectric layer composed of (Ca) 1-x-y Sr x Ba y )m(Zr 1-z-α Ti z Hf αThe composition represented by O3, wherein x is 0 or more and less than 1, y is 0 or more and less than 0.4, m is 1.0 or more and less than 1.1, z is 0 or more and less than 0.2, and α is 0 or more and less than 0.3; or TiO2.

[0034] Additives may be added to the ceramic material forming the dielectric layer 14, depending on the purpose. Examples of such additives include oxides of rare earth elements such as Mn, Mg, Dy, Cr, or V, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, Y, or oxides of Co, Ni, Li, B, Na, K, and Si, or glass.

[0035] The thickness of the dielectric layer 14 (i.e., the dimension T in the stacking direction) can be observed by measuring the distance between two adjacent first internal electrodes 15A or the distance between two adjacent second internal electrodes 15B, and for example, it is 1 μm or more and 100 μm or less.

[0036] The internal electrode 15 uses a conductive metal as its main component, for example, at least one of the following metals: Cu, Ni, Ag, Pd, alloys of Ag and Pd, and Au. Furthermore, the main component of the internal electrode is defined as 50% or more by mass of the components constituting the internal electrode. These metals can be compounds containing these metal elements or alloys with other metals. The internal electrode 15 preferably contains Cu. The internal electrode 15 is formed by sintering a conductive paste containing metal powder that serves as a conductor, an organic solvent, a binder, and a dispersant onto the dielectric layer 14.

[0037] The total number of internal electrodes 15 is, for example, 4 or more and 100 or less. The internal electrodes 15 are layered. The thickness of each layer of the internal electrodes 15 (i.e., the dimension T in the stacking direction) is, for example, 0.5 μm or more and 3 μm or less, preferably 1.2 μm or more and 2.4 μm or less. This is because if the thickness of the internal electrodes 15 is less than 1.2 μm, the Q value may become too small. Furthermore, this is because if the thickness of the internal electrodes 15 is greater than 2.4 μm, during firing, the interface between the internal electrodes 15 and the dielectric layer may peel off due to the difference in shrinkage between the internal electrodes 15 and the dielectric layer 14.

[0038] 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 on the first end face CA. The second internal electrodes 15B are exposed only on the second end face CB.

[0039] The plurality of first internal electrodes 15A have a plurality of first internal electrode groups 16A, which are groups of first internal electrodes 15A that are continuously adjacent in the stacking direction T and exposed on the same end face (specifically, the first end face CA).

[0040] Each first internal electrode group 16A includes a plurality of first internal electrodes 15A, specifically, two first internal electrodes 15A. A dielectric layer 14 is disposed between adjacent first internal electrodes 15A in each first internal electrode group 16A. Each first internal electrode group 16A has: a first inner internal electrode 151A, which is the first internal electrode 15A of the first internal electrodes 15A constituting the first internal electrode group 16A that is closest to the central portion in the lamination direction T of the laminate 2; and a first outer internal electrode 152A, which is the first internal electrode 15A of the first internal electrodes 15A constituting the first internal electrode group 16A that is closest to the surface of the laminate 2.

[0041] The plurality of second internal electrodes 15B have a plurality of second internal electrode groups 16B, which are groups of second internal electrodes 15B that are continuously adjacent in the stacking direction T and exposed on the same end face (specifically, the second end face CB).

[0042] Each second internal electrode group 16B includes a plurality of second internal electrodes 15B, specifically, two second internal electrodes 15B. A dielectric layer 14 is disposed between adjacent second internal electrodes 15B in each second internal electrode group 16B. Each second internal electrode group 16B has: a second inner internal electrode 151B, which is the second internal electrode 15B of the second internal electrodes 15B constituting the second internal electrode group 16B that is closest to the central portion in the lamination direction T of the laminate 2; and a second outer internal electrode 152B, which is the second internal electrode 15B of the second internal electrodes 15B constituting the second internal electrode group 16B that is closest to the surface of the laminate 2.

[0043] Multiple first internal electrode groups 16A and multiple second internal electrode groups 16B are alternately arranged in the stacking direction T. A dielectric layer 14 is disposed between adjacent first internal electrode groups 16A and second internal electrode groups 16B. A portion of the first internal electrode group 16A and a portion of the second internal electrode group 16B are opposed to each other in the stacking direction T.

[0044] An electrostatic capacitance is generated between the first internal electrode group 16A and the second internal electrode group 16B. The first internal electrode group 16A can be considered as a single, thicker first internal electrode 15A. Similarly, the second internal electrode group 16B can be considered as a single, thicker second internal electrode 15B. Therefore, the same effect as increasing the thickness of an internal electrode 15 can be obtained, reducing the equivalent series resistance (ESR). Consequently, a multilayer ceramic capacitor 1 with low loss can be obtained.

[0045] In addition, the first internal electrode group 16A and the second internal electrode group 16B are sometimes collectively referred to as "internal electrode group 16". The first inner internal electrode 151A and the second inner internal electrode 151B are sometimes collectively referred to as "inner internal electrode 151". The first outer internal electrode 152A and the second outer internal electrode 152B are sometimes collectively referred to as "outer internal electrode 152".

[0046] (Auxiliary electrode 21)

[0047] In addition, the inner layer 11 includes, for example, a plurality of auxiliary electrodes 21 that are spaced apart from the inner electrode 15 in the length direction L.

[0048] The auxiliary electrode 21 is made of a suitable conductive material, such as a metal like Cu, Ni, Ag, Pd, Au, or an alloy containing at least one of these metals, such as an Ag-Pd alloy, similar to the internal electrode 15.

[0049] The auxiliary electrode 21 includes a plurality of first auxiliary electrodes 21A and a plurality of second auxiliary electrodes 21B.

[0050] The first auxiliary electrode 21A and the second internal electrode 15B are spaced apart along the length direction L. The first auxiliary electrode 21A is exposed at its first end face CA. The first auxiliary electrode 21A is connected to the first external electrode 3A. The first auxiliary electrode 21A and the first internal electrode 15A are opposite each other along the stacking direction T.

[0051] The plurality of first auxiliary electrodes 21A have a plurality of first auxiliary electrode groups 22A, which are groups of first auxiliary electrodes 21A that are continuously adjacent in the stacking direction T.

[0052] A first auxiliary electrode group 22A includes a plurality of first auxiliary electrodes 21A, specifically, two first auxiliary electrodes 21A. The first auxiliary electrode group 22A and the second internal electrode group 16B are spaced apart in the length direction L. In the first auxiliary electrode group 22A, a dielectric layer 14 is disposed between adjacent first auxiliary electrode groups 22A.

[0053] The second auxiliary electrode 21B is spaced apart from the first internal electrode 15A along the length direction L. The second auxiliary electrode 21B is exposed at its second end face CB. The second auxiliary electrode 21B is connected to the second external electrode 3B. The second auxiliary electrode 21B and the second internal electrode 15B are opposite each other along the stacking direction T.

[0054] The plurality of second auxiliary electrodes 21B have a plurality of second auxiliary electrode groups 22B, which are groups of second auxiliary electrodes 21B that are continuously adjacent in the stacking direction T.

[0055] A second auxiliary electrode group 22B includes a plurality of second auxiliary electrodes 21B, specifically, two second auxiliary electrodes 21B. The second auxiliary electrode group 22B is spaced apart from the first internal electrode group 16A in the length direction L. In the second auxiliary electrode group 22B, a dielectric layer 14 is disposed between adjacent second auxiliary electrode groups 22B.

[0056] In addition, the first auxiliary electrode group 22A and the second auxiliary electrode group 22B are sometimes referred to collectively as "auxiliary electrode group 22".

[0057] (Outer layer 12)

[0058] The outer layer 12 is formed of the same material as the dielectric layer 14 of the inner layer 11. Furthermore, no internal electrode 15 is disposed in the outer layer 12.

[0059] (External electrode 3)

[0060] An external electrode 3 is disposed on end face C and connected to the internal electrode 15. The external electrode 3 has a first external electrode 3A disposed on the first end face CA and connected to the first internal electrode 15A, and a second external electrode 3B disposed on the second end face CB and connected to the second internal electrode 15B. Furthermore, the first external electrode 3A covers not only the first end face CA, but also a portion of the main surface A and a portion of the side surface B. The second external electrode 3B covers not only the second end face CB, but also a portion of the main surface A and a portion of the side surface B.

[0061] Furthermore, as described above, the dimension in the width direction W of the laminate 2 is larger than the dimension in the length direction L of the laminate 2. The laminated ceramic capacitor 1 becomes a so-called LW-reversed laminated ceramic capacitor. By making the laminated ceramic capacitor 1 an LW-reversed laminated ceramic capacitor, compared with the case of making it a conventional laminated ceramic capacitor, it is possible to shorten the distance between the external electrodes 3 or increase the width direction W dimension of the external electrodes 3, thereby reducing ESL.

[0062] The external electrodes 3 each include a base electrode layer 31 disposed on the surface of the laminate 2 and a plating layer 32 disposed on the base electrode layer 31.

[0063] The substrate electrode layer 31 uses a conductive metal as its main component, such as Cu, Ni, Ag, Pd, Au, or Ag-Pd alloys. The substrate electrode layer 31 preferably contains Cu. The substrate electrode layer 31 is, for example, a sintered layer comprising a conductive metal and glass. The maximum thickness of the substrate electrode layer 31 is 5 μm or more and 50 μm or less. Furthermore, the term "main component" refers to a component that constitutes 50% or more by mass of the components forming the substrate electrode layer.

[0064] The plating layer 32 is, for example, made of a metal selected from the group consisting of Cu, Ni, Ag, Pd, Au, and Sn, or an alloy containing such metal. The plating layer 32 includes, for example, a first plating layer 321 disposed on the substrate electrode layer 31, and a second plating layer 322 disposed on the first plating layer 321.

[0065] The first plating layer 321 is, for example, a Ni plating layer. The second plating layer 322 is, for example, a Sn (tin) plating layer. Alternatively, the plating layer 32 may be a single-layer structure. The thickness of each plating layer 32 is preferably 0.5 μm or more and 10 μm or less.

[0066] Here, the inner inner electrode 151 of the inner electrode group 16 closest to the surface of the laminate 2 among the plurality of inner electrode groups 16 has an inner curved portion 151a, which is curved into a shape that convexes towards the center in the lamination direction T. For example, the first inner inner electrode 151A of the first inner electrode group 16A closest to the first main surface AA among the plurality of first inner electrode groups 16A has a first inner curved portion 151Aa, which is curved into a shape that convexes towards the center in the lamination direction T of the laminate 2.

[0067] Furthermore, let the inner bend be defined as a bend in the inner internal electrode whose shortest distance to the apex of the bend and the imaginary straight line (denoted as "first imaginary line L1") connecting the ends of the inner internal electrode in the longitudinal direction L is 0.1 μm or more. The first imaginary line L1 is an imaginary straight line originating from the portion of the inner internal electrode's ends in the longitudinal direction closest to the center of the stacking direction.

[0068] The first inner curved portion 151Aa is, for example, roughly V-shaped or roughly U-shaped, convex in the central part of the stacking direction T toward the laminate 2.

[0069] The first outer inner electrode 152A of the inner electrode group 16 closest to the surface of the laminate 2 among the plurality of first inner electrode groups 16A has, for example, a first outer curved portion 152Aa, which is a portion curved into a central convex shape in the lamination direction T. The first outer curved portion 152Aa and the first inner curved portion 151Aa overlap in the lamination direction T.

[0070] The region in the inner layer 11 between the internal electrode 15 exposed at one end face C and the auxiliary electrode 21 located between the internal electrode 15 and the other end face C, extending in the stacking direction T, is designated as the "extension region 25". The apex of the inner curved portion 151a is provided in the portion of the internal electrode 15 exposed at the other end face C located in the extension region 25. For example, the region in the inner layer 11 between the second internal electrode 15B and the first auxiliary electrode 21A located between the second internal electrode 15B and the first end face CA, extending in the stacking direction T, is designated as the "first extension region 25A". The apex of the first inner curved portion 151Aa is provided in the portion of the first inner internal electrode 151A located in the first extension region 25A. However, as long as the apex of the first inner curved portion 151Aa is located in the first extension region 25A, a portion of the first inner curved portion 151Aa may not be provided in the first extension region 25A. In addition, the so-called "apex of the inner curvature" refers to the central part of the inner curvature that is closest to the stacking direction of the stacked body.

[0071] In the inner electrode group 16 closest to the surface of the laminate 2 among the multiple inner electrode groups 16, the bending magnitude of the inner bend 151a is larger than that of the outer inner electrode 152. For example, as Figure 4 As shown, the size of the bend of the first inner curved portion 151Aa (denoted as "TI") is larger than the size of the bend of the first outer inner electrode 152A (denoted as "TO").

[0072] In addition, the curvature of the inner curved portion is the shortest distance between the vertex of the curved portion of the inner electrode and the first imaginary line L1.

[0073] The degree of bending of the outer inner electrode is determined by defining an imaginary straight line connecting each end of the outer inner electrode along its length L as "the second imaginary line L2" and an imaginary straight line extending from the shortest distance connecting the first imaginary line L1 and the vertex of the inner inner electrode as "the third imaginary line L3," as the shortest distance between the intersection point of the second imaginary line L2 and the outer inner electrode and the third imaginary line L3. Furthermore, the second imaginary line L2 is an imaginary straight line originating from the portion of the outer inner electrode's length end closest to the center of the stacking direction. The outer inner electrode may also remain unbent.

[0074] The bending size of the inner internal electrode 151 is preferably 0.5 μm or more and 3 μm or less. For example, the bending size of the first inner internal electrode 151A is preferably 0.5 μm or more and 3 μm or less.

[0075] An auxiliary electrode 21 is present on the extension line of the internal electrode 15. For example, a first auxiliary electrode 21A is present on the extension line of the second internal electrode 15B. The end of the first auxiliary electrode 21A on the side of the second internal electrode 15B and the end of the second internal electrode 15B on the side of the first auxiliary electrode 21A are opposite each other in the length direction L.

[0076] Furthermore, the so-called "extension line of the internal electrode" is an imaginary straight line connecting the central portion of one end in the stacking direction T of the internal electrode along its length direction L to the central portion of the other end in the stacking direction T.

[0077] Furthermore, the second inner electrode 151B of the second inner electrode group 16B closest to the second main surface AB among the plurality of second inner electrode groups 16B has a second inner curved portion 151Ba, which is a portion curved into a shape that convexes towards the center of the laminate 2 in the lamination direction T. The second inner curved portion 151Ba is, for example, in a generally V-shaped or generally U-shaped form that convexes towards the center of the laminate 2 in the lamination direction T.

[0078] The second outer inner electrode 152B of the second inner electrode group 16B closest to the surface of the laminate 2 among the plurality of second inner electrode groups 16B has, for example, a second outer curved portion 152Ba, which is a portion curved into a shape that convexes towards the center in the lamination direction T. The second outer curved portion 152Ba and the second inner curved portion 151Ba overlap in the lamination direction T.

[0079] The region extending in the lamination direction T between the first internal electrode 15A in the inner layer 11 and the second auxiliary electrode 21B located between the first internal electrode 15A and the second end face CB is designated as the "second extended region 25B". The apex of the second inner curved portion 151Ba is provided in the portion of the second inner internal electrode 151B located in the second extended region 25B. However, as long as the apex of the second inner curved portion 151Ba is located in the second extended region 25B, a portion of the second inner curved portion 151Ba may not be provided in the second extended region 25B.

[0080] The curvature of the second inner curved portion 151Ba is greater than that of the second outer curved portion 152Ba.

[0081] The bending size of the second inner electrode 151B is preferably 0.5 μm or more and 3 μm or less.

[0082] The second auxiliary electrode 21B is located on the extension line of the first internal electrode 15A.

[0083] The first internal electrode group 16A and the second internal electrode group 16B are sometimes collectively referred to as "internal electrode group 16". The first inner internal electrode 151A and the second inner internal electrode 151B are sometimes collectively referred to as "inner internal electrode 151". The first inner curved portion 151Aa and the second inner curved portion 151Ba are sometimes collectively referred to as "inner curved portion 151a". The first outer internal electrode 152A and the second outer internal electrode 152B are sometimes collectively referred to as "outer internal electrode 152". The first outer curved portion 152Aa and the second outer curved portion 152Ba are sometimes collectively referred to as "outer curved portion 152a". The first extended region 25A and the second extended region 25B are sometimes collectively referred to as "extended region 25".

[0084] (Manufacturing method of multilayer ceramic capacitor 1)

[0085] Next, the manufacturing method of the multilayer ceramic capacitor 1 according to the embodiment will be described.

[0086] (Printing process)

[0087] First, prepare a dielectric sheet, a conductive paste for the internal electrode, and a conductive paste for the auxiliary electrode. These materials contain an adhesive and a solvent. The adhesive and solvent may be, for example, known adhesives and solvents. The conductive paste for the internal electrode and the conductive paste for the auxiliary electrode also contain metal powder. Furthermore, the components of the conductive paste for the internal electrode and the conductive paste for the auxiliary electrode may differ.

[0088] Next, for example, conductive paste for internal electrodes and conductive paste for auxiliary electrodes are printed on the dielectric sheet in a given pattern using screen printing, gravure printing, or the like. The conductive paste for internal electrodes and conductive paste for auxiliary electrodes are printed at intervals along the length direction L. This yields a dielectric sheet for the inner layer printed with conductive paste for internal electrodes and conductive paste for auxiliary electrodes.

[0089] As the dielectric sheet used in the outer layer, a dielectric sheet without printed internal electrode patterns and auxiliary electrode patterns is prepared. Furthermore, the components contained in the dielectric sheet used in the inner layer and the dielectric sheet used in the outer layer can be different.

[0090] (Layering process)

[0091] Next, dielectric sheets for the inner layers are laminated. When laminating the dielectric sheets for the inner layers, the following operation is repeated: multiple dielectric sheets printed with conductive paste serving as a first internal electrode and conductive paste serving as a second auxiliary electrode are continuously laminated; then multiple dielectric sheets printed with conductive paste serving as a second internal electrode and conductive paste serving as a first auxiliary electrode are continuously laminated. This forms a first internal electrode group 16A, a second internal electrode group 16B, a first auxiliary electrode group 22A, and a second auxiliary electrode group 22B.

[0092] Here, the dielectric sheets for the inner layer are pressed and stacked in the lamination direction. The dielectric sheets for the inner layer can be pressed at a time when one sheet is stacked, or at a time when multiple sheets are stacked. When pressing the dielectric sheets, the pressure applied to the portion of the inner electrode that is to be bent is set to be greater than the pressure applied to other portions. As a result, the portion of the conductive paste used for the inner electrode located in the extension region is bent into a state that bulges toward the center of the lamination direction T of the laminate. Thus, the conductive paste used for the inner electrode forms an inner bent portion 151a. Furthermore, the size of the bend of the inner bent portion 151a is adjusted by adjusting the pressure applied during pressing.

[0093] Furthermore, when the auxiliary electrode 21 is provided in the inner layer 11, the conductive paste for the pressed inner electrode deforms, causing it to enter the area between the previously stacked conductive paste for the inner electrode and the conductive paste for the auxiliary electrode. Therefore, even without setting too large a difference in pressure for each part of the conductive paste, the inner curved portion 151a can be appropriately formed. Thus, by providing the auxiliary electrode 21 in the inner layer 11, the inner curved portion 151a can be easily formed in the inner electrode 15. In addition, the inner curved portion 151a can be easily formed in a suitable position (i.e., in the portion located in the extension region 25). However, even without providing the auxiliary electrode 21 in the inner layer 11, the inner curved portion 151a can be formed in the inner inner electrode 151 by applying stronger pressure than other parts to the part of the conductive paste for the inner electrode that is to be bent during pressing.

[0094] Furthermore, the outer curved portion 152a can be formed, for example, by laminating a dielectric sheet on which a conductive paste is printed to become the outer inner electrode 152, wherein the conductive paste and the dielectric sheet are bent along the curve of the inner curved portion 151a.

[0095] The dielectric sheet constituting the portion of the inner layer 11 near the first main surface AA and the dielectric sheet constituting the portion of the inner layer 11 near the second main surface AB are, for example, stacked separately and then combined. Therefore, either the inner internal electrode 151 located in the portion near the first main surface AA in the laminate 2 and the inner internal electrode 151 located in the portion near the second main surface AB in the laminate 2 can form a bend that convexes towards the center in the lamination direction T of the laminate 2.

[0096] Next, outer dielectric sheets are stacked on both sides of the inner dielectric sheet in the stacking direction. The outer dielectric sheets are then thermo-pressed onto the inner dielectric sheets. This yields a master block. The master block is then pressed in the stacking direction using methods such as isostatic pressing.

[0097] In addition, each outer layer 12 can be obtained by stacking multiple dielectric sheets or by being composed of a single dielectric sheet.

[0098] (Main block cutting process)

[0099] Next, the mother block is cut along a cutting line corresponding to the size of the laminate 2. For example, the mother block is cut in the length direction L and the width direction W. This yields multiple cuboid blocks (called "laminated pieces"). Furthermore, it is preferable, for example, to round the corners and edges of the laminated pieces by tumbling.

[0100] (Laminated body firing process)

[0101] Next, the laminated sheets are heated in a nitrogen atmosphere for a given time at a given firing temperature. This yields laminate 2. Furthermore, since the internal electrode 15 contains Cu as the main component, Cu has excellent oxidation resistance, allowing the atmosphere during co-firing of the dielectric layer 14 and the internal electrode 15 to be set closer to the oxidation side. This suppresses the reduction of Ca(Zr,Ti)O3-type compounds. Perovskite compounds such as Ca(Zr,Ti)O3 exhibit semiconductor properties when reduced, potentially resulting in poor dielectric properties; however, this undesirable condition can be suppressed.

[0102] (Substrate electrode layer formation process)

[0103] Next, a base electrode layer 31 is formed on each end face C of the laminate 2. A conductive paste containing glass and metal is applied to the laminate 2. Each base electrode layer 31 is formed, for example, to cover a portion of each end face C, a portion of each main face A, and a portion of each side face B. However, it is not limited to this, and each base electrode layer 31 may also be disposed only on each end face C.

[0104] (Substrate electrode layer sintering process)

[0105] Next, the laminate 2 with the base electrode layer 31 formed thereon is heated in a nitrogen atmosphere at a given firing temperature for a given time. Thus, the base electrode layer 31 is fired onto the laminate 2. Furthermore, the laminate firing process and the base electrode layer firing process can be performed simultaneously after the base electrode layer material is placed on the laminated sheet. Moreover, when the base electrode layer 31 contains Cu as the main component, the firing atmosphere can be set closer to the oxidation side. This suppresses the reduction of Ca(Zr,Ti)O3-like compounds.

[0106] (Platinum coating process)

[0107] Next, a plating layer 32 is formed on the substrate electrode layer 31. First, a first plating layer 321 is formed on the substrate electrode layer 31. Then, a second plating layer 322 is formed on the first plating layer 321. The first plating layer 321 is formed, for example, by a Ni plating layer. The second plating layer 322 is formed, for example, by a Sn plating layer. The first plating layer 321 and the second plating layer 322 are formed sequentially, for example, by an electrolytic plating method.

[0108] Based on the above, we can obtain Figure 1 The stacked ceramic capacitor 1 shown.

[0109] <Experimental Example>

[0110] Examples and comparative examples will be described. The experimental methods and results will be described below.

[0111] 1. Manufacturing of multilayer ceramic capacitors

[0112] As an experimental and comparative example, a sample with the same structure as the aforementioned multilayer ceramic capacitor 1 was fabricated. Figures 1-4 The multilayer ceramic capacitor (with the structure shown) is used. The manufacturing method of the sample multilayer ceramic capacitor is the manufacturing method described in the above embodiment. The comparative example is Comparative Example 1. The experimental examples are Experimental Examples 1 to 7. 10,000 sample multilayer ceramic capacitors were manufactured for each experimental example and comparative example.

[0113] In all experimental and comparative examples, the dimensions of the multilayer ceramic capacitor were L×W×T=0.3mm×0.6mm×0.18mm.

[0114] In each experimental and comparative example, the degree of bending of the internal electrode varied. The degree of bending of the internal electrode in each experimental example was adjusted by adjusting the lamination pressure during the lamination process. In the case of the comparative example, the lamination pressure during the lamination process was set to a constant at each location of the internal electrode.

[0115] The bending magnitude of the internal electrode in each experimental and comparative example is shown in Table 1. Additionally, the bending magnitude of the inner bending portion is sometimes referred to as "TI," and the bending magnitude of the outer internal electrode is sometimes referred to as "TO."

[0116] 2. Evaluation

[0117] Next, the prepared samples were measured and evaluated according to the following methods. The withstand voltage, the degree of bending of the internal electrodes, and the rate of internal structural defects were measured, among other things.

[0118] <Voltage Withstand>

[0119] Withstand voltage was tested (DC-BDV test) under the conditions of a boost rate of 100V / second and a detection current of 10mA, and the withstand voltage of each sample was measured.

[0120] According to each embodiment and comparative example, the withstand voltage was measured on 20 samples randomly selected from 10,000 samples. The average value of the obtained withstand voltage was set as the withstand voltage of each embodiment and comparative example.

[0121] In addition, for samples that are the subjects of voltage withstand tests, other tests are performed after the voltage withstand test is performed.

[0122] <The size of the bend in the internal electrodes>

[0123] The magnitude of the bend in the inner bend of the inner electrode group closest to the surface of the stack and the magnitude of the bend in the outer inner electrode were measured.

[0124] The LT cross-section of the central portion in the width direction W of the multilayer ceramic capacitor was exposed by grinding and observed with an optical microscope. In the internal electrode group closest to the surface of the multilayer, the bending size of the inner bending portion and the bending size of the outer internal electrode were measured according to the definition described in the above embodiment.

[0125] According to each embodiment and comparative example, the bending magnitude of the inner curved portion and the bending magnitude of the outer internal electrode were measured for 10,000 samples. The average value of the obtained bending magnitude of the inner curved portion was set as the bending magnitude of the inner curved portion of each embodiment and comparative example. The average value of the obtained bending magnitude of the outer internal electrode was set as the bending magnitude of the outer internal electrode of each embodiment and comparative example.

[0126] Furthermore, for each embodiment and comparative example, the value of the bending size of the inner curved portion divided by the bending size of the outer inner electrode (sometimes referred to as "TI / TO") was calculated.

[0127] <Internal structural defect occurrence rate>

[0128] An LT cross-section passing through the central portion in the width direction W of a multilayer ceramic capacitor was observed using an optical microscope. The presence or absence of interlaminar delamination between the internal electrode group closest to the surface of the stack and the dielectric layer adjacent to the internal electrode group, as well as the presence or absence of cracks in the dielectric layer adjacent to the internal electrode group, were observed. Samples showing at least one of interlaminar delamination and cracks were defined as samples with internal structural defects.

[0129] According to each embodiment and comparative example, the number of samples that produced internal structural defects was counted for each of the 10,000 samples. The number of samples that produced internal structural defects out of the 10,000 samples was defined as the "internal structural defect generation rate".

[0130] <Determination of Qualification>

[0131] According to each embodiment and comparative example, a qualification or non-qualification determination was performed.

[0132] If the internal structural defect occurrence rate is 0 / 10000 and the withstand voltage is above 800V, the judgment result will be set as "qualified".

[0133] In cases where the judgment result is qualified, if the internal structural defect occurrence rate is less than 10 / 10000 and the withstand voltage is above 800V, the judgment result will be set as "generally qualified".

[0134] If the internal structural defect rate is above 10 / 10000, the judgment result will be set as "unqualified".

[0135] 3. Measurement Results

[0136] Table 1 shows the TI (μm), TO (μm), TI / TO, internal structural defect occurrence rate, withstand voltage (V), and judgment results for Comparative Example 1 and Experimental Examples 1 to 7, respectively.

[0137] [Table 1]

[0138]

[0139] In Comparative Example 1, the TI was 0.05 μm. In Comparative Example 1, the internal structural defect occurrence rate was 10 / 10000, resulting in a failing grade. However, in Comparative Example 1, the withstand voltage was 852 V, which was considered a good result.

[0140] In Experiments 1 through 7, the TI (Temperature Inclusion) was 0.1 μm or more and 6 μm or less. In Experiments 1 through 7, the internal structural defect rejection rate was 3 / 10000 or less, which is considered a good result. In particular, in Experiments 2 through 7, the internal structural defect rejection rate was 0 / 10000, which is an even better result.

[0141] In Experiments 2 through 7, the TI / TO ratio was 8.3 or higher and 42.9 or lower. In the samples from Experiments 2 through 7, the inner internal electrode exhibited significant bending, while the outer internal electrode showed almost no bending. It can be assumed that the significant bending of the internal electrode improved the adhesion between the dielectric layer and the inner internal electrode. Conversely, the near absence of bending on the outer internal electrode suppressed the decrease in adhesion between the outer internal electrode and the outer layer. Therefore, it can be considered that the generation of internal structural defects was appropriately suppressed.

[0142] In Experiment 7, the dielectric constant (TI) was 6 μm. The internal structural defect rate was 0 / 10000, a good result. However, the withstand voltage was 793 V, slightly lower than the results of Experiments 1 through 6. It can be assumed that in Experiment 7, the excessively high TI resulted in an excessively thin dielectric near the bend of the inner electrode, leading to a decrease in withstand voltage.

[0143] Based on the above, as shown in the results of Experiments 2 to 6, it has been confirmed that by setting TI to 0.5 μm or more and 3 μm or less, the generation of internal structural defects can be appropriately suppressed, and the withstand voltage can be ensured within a good range. It has been confirmed that by setting TI to 0.5 μm or more and 3 μm or less, multilayer ceramic capacitors with excellent reliability can be obtained. Furthermore, it has been confirmed that by setting TI / TO to 8.3 or more and 28.6 or less, the generation of internal structural defects can be suppressed more reliably and appropriately, and the withstand voltage can be ensured within a good range.

[0144] (Effects related to the implementation method)

[0145] According to this embodiment, the following effects can be obtained.

[0146] According to the above embodiment, the multilayer ceramic capacitor 1 includes a multilayer body 2 and a pair of external electrodes 3 disposed on each end face C of the multilayer body 2 and connected to the internal electrodes 15. The dimension of the multilayer body 2 in the width direction W is larger than the dimension in the length direction L of the multilayer body. The multiple internal electrodes 15 have multiple internal electrode groups 16. Each internal electrode group 16 is a group of internal electrodes 15 that are continuously adjacent in the stacking direction T and exposed on the same end face C. Each internal electrode group 16 has an inner internal electrode 151 and an outer internal electrode. The inner internal electrode 151 is the internal electrode 15 that is closest to the center of the multilayer body 2 in the stacking direction T among the internal electrodes 15 of the internal electrode group 16. The outer internal electrode is the internal electrode that is closest to the surface of the multilayer body 2 among the internal electrodes 15 of the internal electrode group 16. The inner inner electrode 151 of the inner electrode group 16 closest to the surface of the laminate 2 among the multiple inner electrode groups 16 has an inner curved portion 151a, which is a portion that is curved into a shape that convexes towards the center in the lamination direction T of the laminate 2.

[0147] Based on this structure, the multilayer ceramic capacitor 1 becomes a so-called LW inverse type multilayer ceramic capacitor. Therefore, the ESL of the multilayer ceramic capacitor 1 can be reduced. Furthermore, according to the LW inverse type multilayer ceramic capacitor 1, even in the high-frequency region, the ESL can be appropriately reduced.

[0148] Furthermore, an internal electrode group 16 includes multiple internal electrodes 15, thereby achieving the same effect as increasing the thickness of an internal electrode. This reduces the ESR of the internal electrodes 15. In the high-frequency region, by reducing the ESR of the internal electrodes 15, the ESR of the multilayer ceramic capacitor 1 can be appropriately reduced. Therefore, in the high-frequency region, the ESR of the multilayer ceramic capacitor 1 can be appropriately reduced.

[0149] Furthermore, around the inner electrode group 16 near the surface of the laminate 2, steps can easily form due to the thickness of the inner electrode 15, thus reducing the adhesion between the dielectric layer 14 and the inner inner electrode 151. However, by providing an inner bend 151a to the inner inner electrode 151, an anchoring effect can be achieved between the inner inner electrode 151 and the dielectric layer 14. Consequently, the adhesion between the inner inner electrode 151 and the dielectric layer 14 can be improved. This, in turn, suppresses the formation of cracks, delamination, and other defects around the inner electrode group 16.

[0150] Therefore, a multilayer ceramic capacitor 1 is provided that can suppress energy loss in the high-frequency region, achieve ESL reduction, and suppress internal structural defects.

[0151] According to the above embodiment, the inner layer 11 includes an auxiliary electrode 21 that is spaced apart from the inner electrode 15 in the length direction L. If the region between the inner electrode 15 exposed on one end face C and the auxiliary electrode 21 located between the inner electrode 15 and the other end face C is defined as the extended region, then the apex of the inner curved portion 151a is provided in the portion of the inner inner electrode 151 exposed on the other end face C located in the extended region 25.

[0152] With this structure, by providing an auxiliary electrode 21 in the inner layer 11, the proportion of metal in the laminate 2 can be increased. The toughness of the metal is higher than that of the dielectric layer 14. As a result, the mechanical strength of the laminate 2 can be improved, thus suppressing the generation of cracks in the laminate 2.

[0153] In the extended region 25, the adhesion between the internal electrode 15 and the dielectric layer 14 is weaker compared to the portions where the internal electrode group 16 faces each other and the portions where the internal electrode group 16 and the auxiliary electrode 21 face each other. However, according to this structure, by arranging the inner curved portion 151a in the extended region 25, the adhesion between the inner internal electrode 151 and the dielectric layer 14 can be further improved. As a result, internal structural defects can be more appropriately suppressed.

[0154] During the pressing process in the lamination step, bending of the portion of the internal electrode 15 that is opposite to the auxiliary electrode 21 in the lamination direction T can be suppressed. As a result, bending near the end of the internal electrode 15 in the length direction L can be suppressed, and thus the internal electrode 15 can be easily bent into a generally V-shape or a generally U-shape.

[0155] According to the above embodiment, in the inner electrode group 16 closest to the surface of the laminate 2 among the plurality of inner electrode groups 16, the bending size of the inner bending portion 151a is greater than the bending size of the outer inner electrode 152.

[0156] According to this structure, by making the inner internal electrode 151 more curved, the adhesion between the inner internal electrode 151 and the dielectric layer can be improved. Furthermore, if the outer curved portion 152a bends significantly towards the center of the laminate 2, the adhesion between the outer curved portion 152a and the outer layer 12 may decrease, but this undesirable situation can be suppressed. Thus, internal structural defects can be more appropriately suppressed.

[0157] According to the above embodiment, the bending size of the inner bending portion 151a is 0.5 μm or more and 3 μm or less.

[0158] With this structure, energy loss in the high-frequency region can be effectively suppressed, and the interface peeling of the internal electrode 15 and the dielectric layer 14 due to the difference in shrinkage between the internal electrode 15 and the dielectric layer 14 during firing can be suppressed.

[0159] According to the above embodiment, the auxiliary electrode 21 is located on the extension line of the internal electrode 15.

[0160] With this structure, the increase in the dimension T of the stacking direction of the laminate 2, which is caused by the thickness of the auxiliary electrode 21, can be suppressed, and thus the laminated ceramic capacitor 1 can be easily formed thin.

[0161] According to the above embodiment, the internal electrode 15 contains Cu, and the external electrode 3 has a base electrode layer 31 disposed on the surface of the laminate 2, the base electrode layer 31 containing Cu.

[0162] Due to this structure, Cu has low resistance, which is caused by low conductor loss, thus enabling low-loss multilayer ceramic capacitors.

[0163] According to the above embodiments, the dielectric layer 14 is any of the following: having a dielectric layer composed of (Ca... 1-x-y Sr x Ba y )m(Zr 1-z-α Ti z Hf α The composition represented by O3, wherein x is 0 or more and less than 1, y is 0 or more and less than 0.4, m is 1.0 or more and less than 1.1, z is 0 or more and less than 0.2, and α is 0 or more and less than 0.3; or TiO2.

[0164] Based on this structure, multilayer ceramic capacitors with low electrostatic capacitance temperature change rate and low loss can be obtained.

[0165] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments and various changes and modifications can be made.

[0166] In the above embodiments, an internal electrode group 16 includes two internal electrodes 15, but an internal electrode group may also include three or more internal electrodes.

[0167] In the above embodiment, a first outer bend 152Aa is provided on the first outer inner electrode 152A, and a second outer bend 152Ba is provided on the second outer inner electrode 152B. However, the first outer bend 152Aa and the second outer bend 152Ba are not essential structures. From the viewpoint of suppressing the decrease in the adhesion force between the outer inner electrode and the outer layer, the outer inner electrode preferably does not bend toward the center of the laminate in the lamination direction.

[0168] In the above embodiment, the first inner electrode 151A has a first inner bend 151Aa, and the second inner electrode 151B has a second inner bend 151Ba. However, it is sufficient for at least either the first inner electrode 151A or the second inner electrode 151B to have an inner bend. However, by having both the first inner electrode 151A and the second inner electrode 151B have inner bends, the above-described effects can be obtained more appropriately.

[0169] Furthermore, the present invention includes the following combinations.

[0170] <1> A multilayer ceramic capacitor, comprising:

[0171] A laminate includes an inner layer comprising alternatingly stacked dielectric layers and a plurality of internal electrodes; a pair of main faces opposing each other in the stacking direction; a pair of side faces opposing each other in a width direction orthogonal to the stacking direction; and a pair of end faces opposing each other in a length direction orthogonal to both the stacking direction and the width direction; and external electrodes disposed on the end faces and connected to the internal electrodes. The dimension of the laminate in the width direction is larger than the dimension of the laminate in the length direction. The plurality of internal electrodes have a plurality of internal electrode groups, which are continuously adjacent in the stacking direction and exposed on the same end face. The internal electrode group comprises an inner internal electrode and an outer internal electrode. The inner internal electrode is the internal electrode of the internal electrode group that is closest to the center of the stacked body in the stacking direction. The outer internal electrode is the internal electrode of the internal electrode group that is closest to the surface of the stacked body. The inner internal electrode of the internal electrode group closest to the surface of the stacked body has an inner curved portion, which is a portion that is curved into a shape that convexes toward the center of the stacked body in the stacking direction.

[0172] <2> according to <1> The aforementioned multilayer ceramic capacitor, wherein,

[0173] The inner layer includes an auxiliary electrode that is spaced apart from the inner electrode in the length direction. If the region in the inner layer that extends in the stacking direction between the inner electrode exposed on one end face and the auxiliary electrode located between the inner electrode and the other end face is defined as an extended region, then the apex of the inner curved portion is provided in the portion of the inner inner electrode exposed on the other end face located in the extended region.

[0174] <3> according to <1> or <2> The aforementioned multilayer ceramic capacitor, wherein,

[0175] In the inner electrode group closest to the surface of the laminate among the plurality of inner electrode groups, the curvature of the inner bend is greater than that of the outer inner electrode.

[0176] <4> according to <1> ~ <3> The multilayer ceramic capacitor described in any one of the following, wherein,

[0177] The curvature of the inner curved portion is greater than 0.5 μm and less than 3 μm.

[0178] <5> according to <2> ~ <4> The multilayer ceramic capacitor described in any one of the following, wherein,

[0179] The auxiliary electrode is located on the extension line of the internal electrode.

[0180] <6> according to <1> ~ <5> The multilayer ceramic capacitor described in any one of the following, wherein,

[0181] The internal electrode contains Cu, and the external electrode has a base electrode layer disposed on the surface of the laminate, the base electrode layer containing Cu.

[0182] <7> according to <1> ~ <6> The multilayer ceramic capacitor described in any one of the following, wherein,

[0183] The dielectric layer is any of the following:

[0184] Having (Ca) 1-x-y Sr x Ba y )m(Zr 1-z-α Ti z Hf α The composition represented by O3, wherein x is 0 or more and less than 1, y is 0 or more and less than 0.4, m is 1.0 or more and less than 1.1, z is 0 or more and less than 0.2, and α is 0 or more and less than 0.3; or

[0185] It is TiO2.

[0186] Explanation of reference numerals in the attached figures

[0187] 1: Multilayer ceramic capacitor;

[0188] 2: Layered body;

[0189] 3: External electrode;

[0190] 14: Dielectric layer;

[0191] 15: Internal electrodes;

[0192] 16: Internal electrode assembly;

[0193] 21: Auxiliary electrode;

[0194] 25: Extend the area;

[0195] 31: Substrate electrode layer;

[0196] 151: Inner internal electrode;

[0197] 151a: Inner curved portion;

[0198] 152: External internal electrode;

[0199] A: A pair of main faces;

[0200] B: A pair of side views;

[0201] C: A pair of end faces.

Claims

1. A multilayer ceramic capacitor, comprising: A laminate has an inner layer comprising alternatingly stacked dielectric layers and a plurality of internal electrodes, a pair of main surfaces facing each other in the stacking direction, a pair of side surfaces facing each other in a width direction orthogonal to the stacking direction, and a pair of end surfaces facing each other in a length direction orthogonal to both the stacking direction and the width direction; and An external electrode is disposed on the end face and connected to the internal electrode. The dimension of the laminate in the width direction is larger than the dimension of the laminate in the length direction. The plurality of internal electrodes have a plurality of internal electrode groups, wherein the internal electrode group comprises a group of internal electrodes that are continuously adjacent in the stacking direction and exposed on the same end face. Each of the internal electrode groups has an inner internal electrode and an outer internal electrode. The inner internal electrode is the internal electrode of the internal electrode group that is closest to the center of the laminate in the lamination direction. The outer internal electrode is the internal electrode of the internal electrode group that is closest to the surface of the laminate. The inner inner electrode of the inner electrode group closest to the surface of the stack has an inner curved portion, which is a portion that is curved into a shape that convexes towards the center of the stack in the stacking direction of the stack.

2. The multilayer ceramic capacitor according to claim 1, wherein, The inner layer includes auxiliary electrodes that are spaced apart from the inner electrodes in the length direction. If the region between the internal electrode exposed on one end face and the auxiliary electrode located between the internal electrode and the other end face in the inner layer is extended in the stacking direction, then... The apex of the inner bend is provided in the portion of the extended region within the inner electrode exposed on the other end face.

3. The multilayer ceramic capacitor according to claim 1 or 2, wherein, In the inner electrode group closest to the surface of the laminate among the plurality of inner electrode groups, the curvature of the inner bend is greater than that of the outer inner electrode.

4. The multilayer ceramic capacitor according to any one of claims 1 to 3, wherein, The curvature of the inner curved portion is greater than 0.5 μm and less than 3 μm.

5. The multilayer ceramic capacitor according to any one of claims 2 to 4, wherein, The auxiliary electrode is located on the extension line of the internal electrode.

6. The multilayer ceramic capacitor according to any one of claims 1 to 5, wherein, The internal electrode contains Cu. The external electrode has a base electrode layer disposed on the surface of the laminate. The substrate electrode layer contains Cu.

7. The multilayer ceramic capacitor according to any one of claims 1 to 6, wherein, The dielectric layer is any of the following: Having (Ca) 1-x-y Sr x Ba y )m(Zr 1-z-α Ti z Hf α The composition represented by O3, wherein x is 0 or more and less than 1, y is 0 or more and less than 0.4, m is 1.0 or more and less than 1.1, z is 0 or more and less than 0.2, and α is 0 or more and less than 0.3; or It is TiO2.

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