Multilayer ceramic electronic component

Abstract

To provide a multilayer ceramic electronic component capable of achieving an improvement in deflection resistance.SOLUTION: A multilayer ceramic electronic component includes a laminate 10 including an internal electrode layer 30, and a pair of external electrodes 40 disposed on both ends of the laminate 10. The external electrodes 40 each include a main surface side external electrode 411A, and the main surface side external electrode 411A has a surface 411sA facing a main surface TS. The surface 411sA includes a step portion 900 that lowers the height of the surface 411sA, of the laminate 10, on a center side in a length direction L than that of the surface 411sA of the laminate 10 on the outside in the length direction L, in the height from the main surface TS to the surface 411sA. The step portion 900 has a shape curved convexly toward the center in the length direction L and extends across a width direction W at the surface 411sA.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a multilayer ceramic electronic component. [Background technology]

[0002] Multilayer ceramic capacitors have been known as multilayer ceramic electronic components. Generally, a multilayer ceramic capacitor includes a laminate in which dielectric layers and internal electrode layers are alternately stacked, and external electrodes provided on both end surfaces of the laminate. For example, Patent Document 1 discloses a multilayer ceramic capacitor having the above-described structure, in which the external electrodes include base electrode layers formed by baking. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-243249 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in this type of multilayer ceramic capacitor, there is a concern that when the capacitor is mounted on a substrate, bending stress generated in the external electrodes is transmitted to the laminate, causing cracks in the laminate, etc. Therefore, a multilayer ceramic capacitor with improved bending resistance is desired.

[0005] An object of the present invention is to provide a multilayer ceramic electronic component that can improve resistance to bending. [Means for solving the problem]

[0006] A multilayer ceramic capacitor according to the present invention comprises a laminate including a plurality of ceramic layers and a plurality of internal conductor layers alternately stacked in a height direction, and including a pair of main surfaces opposing each other in the height direction, a pair of end faces opposing each other in a length direction perpendicular to the height direction, and a pair of side surfaces opposing each other in a width direction perpendicular to the height direction and the length direction; and a pair of external electrodes disposed spaced apart from each other at both ends in the length direction of the laminate, wherein the main surfaces include a first main surface and a second main surface opposing each other in the height direction, the end faces include a first end face and a second end face opposing each other in the length direction, and the side surfaces include a first side face and a second side face opposing each other in the width direction. the internal conductor layer includes a first internal conductor layer that is extended to the first end face and a second internal conductor layer that is extended to the second end face, the external electrode includes a main surface side external electrode that is arranged on at least one of the first main surface and the second main surface, the main surface side external electrode having a surface facing the main surface, the surface having a step portion that makes the height of the surface on the center side in the longitudinal direction of the laminate lower than the height of the surface on the outer side in the longitudinal direction of the laminate from the main surface to the surface, the step portion having a curved shape that is convex toward the center in the longitudinal direction and extending across the width direction on the surface. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a multilayer ceramic electronic component that can improve resistance to bending. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is an external perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention; [Figure 1B] FIG. 1B is a view taken along the arrow IB in FIG. 1A. [Figure 1C] FIG. 1B is a view taken along the arrow IC in FIG. 1A. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIGS. 1A and 1B. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIGS. 1C and 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIGS. 1C and 2. [Figure 5] 3 is an enlarged view of a portion indicated by V in FIG. 2, showing a cross section of a first main surface side external electrode. FIG. [Figure 6A] FIG. 2 is a diagram illustrating a method for manufacturing a multilayer ceramic capacitor according to an embodiment, showing a first step of forming external electrodes on a laminate. [Figure 6B] 4A and 4B are diagrams illustrating a method for manufacturing the multilayer ceramic capacitor according to the embodiment, showing a second step of forming external electrodes on the laminate. [Figure 7A] FIG. 1 is a diagram showing a multilayer ceramic capacitor with a double structure. [Figure 7B] FIG. 1 is a diagram showing a multilayer ceramic capacitor with a triple structure. [Figure 7C] FIG. 1 is a diagram showing a multilayer ceramic capacitor with a four-element structure. DETAILED DESCRIPTION OF THE INVENTION

[0009] A multilayer ceramic capacitor 1 as a multilayer ceramic electronic component according to an embodiment will be described below with reference to FIGS. 1A to 4. FIG. 1A is an external perspective view of the multilayer ceramic capacitor 1 of the embodiment. FIG. 1B is a view taken along arrow IB in FIG. 1A. FIG. 1C is a view taken along arrow IC in FIG. 1A. FIG. 2 is a cross-sectional view taken along line II-II in FIGS. 1A and 1B. FIG. 3 is a cross-sectional view taken along line III-III in FIGS. 1C and 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIGS. 1C and 2.

[0010] The multilayer ceramic capacitor 1 includes a laminate 10 and external electrodes 40.

[0011] 1A to 4 show an XYZ Cartesian coordinate system. The length direction L of the multilayer ceramic capacitor 1 and the laminate 10 corresponds to the X direction. The width direction W of the multilayer ceramic capacitor 1 and the laminate 10 corresponds to the Y direction. The stacking direction T as the height direction of the multilayer ceramic capacitor 1 and the laminate 10 corresponds to the Z direction. Here, the cross section shown in FIG. 2 is also referred to as the LT cross section. The cross section shown in FIG. 3 is also referred to as the WT cross section. The cross section shown in FIG. 4 is also referred to as the LW cross section.

[0012] 1A, the laminate 10 includes a pair of main surfaces TS facing in a stacking direction T, a pair of end surfaces LS facing in a length direction L perpendicular to the stacking direction T, and a pair of side surfaces WS facing in a width direction W perpendicular to the stacking direction T and the length direction L. The main surfaces TS include a first main surface TS1 and a second main surface TS2 facing in the stacking direction T. The end surfaces LS include a first end surface LS1 and a second end surface LS2 facing in the length direction L. The side surfaces WS include a first side surface WS1 and a second side surface WS2 facing in the width direction W.

[0013] As shown in FIGS. 1A to 1C, the laminate 10 has a substantially rectangular parallelepiped shape. The dimension of the laminate 10 in the length direction L is not necessarily longer than the dimension in the width direction W. The corners and ridges of the laminate 10 are preferably rounded. A corner is a portion where three surfaces of the laminate intersect, and a ridge is a portion where two surfaces of the laminate intersect. Incidentally, unevenness may be formed on part or all of the surfaces constituting the laminate 10.

[0014] The dimensions of the laminate 10 are not particularly limited, but if the dimension of the laminate 10 in the length direction L is defined as the L dimension, then the L dimension is preferably 0.2 mm or more and 10 mm or less. If the dimension of the laminate 10 in the stacking direction T is defined as the T dimension, then the T dimension is preferably 0.1 mm or more and 10 mm or less. If the dimension of the laminate 10 in the width direction W is defined as the W dimension, then the W dimension is preferably 0.1 mm or more and 10 mm or less.

[0015] As shown in Figures 2 and 3, the laminate 10 has an inner layer portion 11, and a first main surface side outer layer portion 12A and a second main surface side outer layer portion 12B arranged to sandwich the inner layer portion 11 in the stacking direction T.

[0016] The internal layer portion 11 includes a plurality of dielectric layers 20 as a plurality of ceramic layers and a plurality of internal electrode layers 30 as a plurality of internal conductor layers. The internal layer portion 11 includes the internal electrode layer 30 located closest to the first principal surface TS1 in the stacking direction T to the internal electrode layer 30 located closest to the second principal surface TS2. In the internal layer portion 11, the multiple internal electrode layers 30 are arranged opposite each other with the dielectric layer 20 interposed therebetween. The internal layer portion 11 is a portion that generates electrostatic capacitance and essentially functions as a capacitor.

[0017] The plurality of dielectric layers 20 are made of a dielectric material. The dielectric material may be, for example, a dielectric ceramic containing components such as BaTiO3, CaTiO3, SrTiO3, or CaZrO3. The dielectric material may also be one in which a secondary component such as a Mn compound, an Fe compound, a Cr compound, a Co compound, or a Ni compound is added to the above main components.

[0018] The thickness of the dielectric layer 20 is preferably 0.5 μm or more and 30 μm or less. The number of laminated dielectric layers 20 is preferably 10 or more and 1500 or less. Note that this number of dielectric layers 20 is the total number of the dielectric layers in the inner layer portion 11 and the dielectric layers in the first main surface side outer layer portion 12A and the second main surface side outer layer portion 12B.

[0019] The multiple internal electrode layers 30 include first internal electrode layers 31 as multiple first internal conductor layers and second internal electrode layers 32 as multiple second internal conductor layers. The multiple first internal electrode layers 31 are arranged on the multiple dielectric layers 20. The multiple second internal electrode layers 32 are arranged on the multiple dielectric layers 20. The multiple first internal electrode layers 31 and the multiple second internal electrode layers 32 are arranged alternately in the stacking direction T of the laminate 10, with the dielectric layers 20 interposed between them. The first internal electrode layers 31 and the second internal electrode layers 32 are arranged so as to sandwich the dielectric layers 20. In the following, when it is not necessary to distinguish between the first internal electrode layers 31 and the second internal electrode layers 32, the first internal electrode layers 31 and the second internal electrode layers 32 may be collectively referred to as internal electrode layers 30.

[0020] The first internal electrode layer 31 has a first opposing portion 31A opposing the second internal electrode layer 32, and a first lead portion 31B led from the first opposing portion 31A to the first end face LS1. The first lead portion 31B is exposed at the first end face LS1.

[0021] The second internal electrode layer 32 has a second opposing portion 32A opposing the first internal electrode layer 31, and a second lead portion 32B led from the second opposing portion 32A to the second end face LS2. The second lead portion 32B is exposed at the second end face LS2.

[0022] In the embodiment, the first opposing portion 31A and the second opposing portion 32A face each other with the dielectric layer 20 interposed therebetween, thereby forming a capacitance and exhibiting the characteristics of a capacitor.

[0023] The shapes of the first opposing portion 31A and the second opposing portion 32A are not particularly limited, but are preferably rectangular. However, the corners of the rectangular shape may be rounded or the corners of the rectangular shape may be formed at an angle. The shapes of the first drawer portion 31B and the second drawer portion 32B are not particularly limited, but are preferably rectangular. However, the corners of the rectangular shape may be rounded or the corners of the rectangular shape may be formed at an angle.

[0024] The dimension in the width direction W of the first facing portion 31A and the dimension in the width direction W of the first lead portion 31B may be the same dimension, or one of the dimensions may be smaller. The dimension in the width direction W of the second facing portion 32A and the dimension in the width direction W of the second lead portion 32B may be the same dimension, or one of the dimensions may be smaller.

[0025] The first internal electrode layer 31 and the second internal electrode layer 32 are made of an appropriate conductive material, such as a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy containing at least one of these metals. When an alloy is used, the first internal electrode layer 31 and the second internal electrode layer 32 may be made of, for example, an Ag-Pd alloy.

[0026] The thickness of each of the first internal electrode layers 31 and the second internal electrode layers 32 is preferably, for example, about 0.2 μm or more and 2.0 μm or less. The total number of the first internal electrode layers 31 and the second internal electrode layers 32 is preferably 10 or more and 1500 or less.

[0027] The first main surface side outer layer portion 12A is located on the first main surface TS1 side of the laminate 10. The first main surface side outer layer portion 12A is an assembly of multiple dielectric layers 20 located between the first main surface TS1 and the internal electrode layer 30 closest to the first main surface TS1. The dielectric layers 20 used in the first main surface side outer layer portion 12A may be the same as the dielectric layers 20 used in the internal layer portion 11, or may be dielectric layers made of a different material.

[0028] The second main surface side outer layer portion 12B is located on the second main surface TS2 side of the laminate 10. The second main surface side outer layer portion 12B is an assembly of multiple dielectric layers 20 located between the second main surface TS2 and the internal electrode layer 30 closest to the second main surface TS2. The dielectric layers 20 used in the second main surface side outer layer portion 12B may be the same as the dielectric layers 20 used in the internal layer portion 11, or may be dielectric layers made of a different material.

[0029] The laminate 10 has a counter electrode portion 11E. The counter electrode portion 11E is a portion where the first counter portion 31A of the first internal electrode layer 31 and the second counter portion 32A of the second internal electrode layer 32 face each other. The counter electrode portion 11E is configured as a part of the inner layer portion 11. FIG. 4 shows the range of the counter electrode portion 11E in the width direction W and the length direction L. The counter electrode portion 11E is also called the effective portion of the capacitor.

[0030] The laminate 10 has a side surface outer layer portion WG. The side surface outer layer portion WG has a first side surface outer layer portion WG1 and a second side surface outer layer portion WG2. The first side surface outer layer portion WG1 is a portion including the dielectric layer 20 located between the counter electrode portion 11E and the first side surface WS1. The second side surface outer layer portion WG2 is a portion including the dielectric layer 20 located between the counter electrode portion 11E and the second side surface WS2. Figures 3 and 4 show the ranges in the width direction W of the first side surface outer layer portion WG1 and the second side surface outer layer portion WG2. The side surface outer layer portions are also called W gaps or side gaps.

[0031] The laminate 10 has an end surface side outer layer portion LG. The end surface side outer layer portion LG has a first end surface side outer layer portion LG1 and a second end surface side outer layer portion LG2. The first end surface side outer layer portion LG1 is a portion including the dielectric layer 20 located between the counter electrode portion 11E and the first end surface LS1. The second end surface side outer layer portion LG2 is a portion including the dielectric layer 20 located between the counter electrode portion 11E and the second end surface LS2. Figures 2 and 4 show the ranges in the length direction L of the first end surface side outer layer portion LG1 and the second end surface side outer layer portion LG2. The end surface side outer layer portions are also called L gaps or end gaps.

[0032] The external electrode 40 has a first external electrode 40A arranged on the first end face LS1 side and a second external electrode 40B arranged on the second end face LS2 side.

[0033] The first external electrode 40A is disposed on the first end face LS1. The first external electrode 40A is connected to the first internal electrode layer 31. The first external electrode 40A is disposed on a portion of the first main surface TS1 and a portion of the second main surface TS2. In this embodiment, the first external electrode 40A is formed to extend from the first end face LS1 to a portion of the first main surface TS1 and a portion of the second main surface TS2, as well as a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0034] The second external electrode 40B is disposed on the second end face LS2. The second external electrode 40B is connected to the second internal electrode layer 32. The second external electrode 40B is disposed on a portion of the first main surface TS1 and a portion of the second main surface TS2. In the embodiment, the second external electrode 40B is formed to extend from the second end face LS2 to a portion of the first main surface TS1 and a portion of the second main surface TS2, as well as a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0035] As described above, in the laminate 10, the first opposing portion 31A of the first internal electrode layer 31 and the second opposing portion 32A of the second internal electrode layer 32 face each other via the dielectric layer 20, thereby forming a capacitance. Therefore, the characteristics of a capacitor are exhibited between the first external electrode 40A connected to the first internal electrode layer 31 and the second external electrode 40B connected to the second internal electrode layer 32.

[0036] The first external electrode 40A has a first base electrode layer 50A containing a metal component, a first conductive resin layer 60A disposed on the first base electrode layer 50A, and a first plating layer 70A disposed on the first conductive resin layer 60A. The first plating layer 70A has a first Ni plating layer 71A and a first Sn plating layer 72A.

[0037] The second external electrode 40B has a second base electrode layer 50B containing a metal component, a second conductive resin layer 60B disposed on the second base electrode layer 50B, and a second plating layer 70B disposed on the second conductive resin layer 60B. The second plating layer 70B has a second Ni plating layer 71B and a second Sn plating layer 72B.

[0038] Here, the layers constituting the first external electrode 40A and the second external electrode 40B have the same basic configuration. The first external electrode 40A and the second external electrode 40B are generally symmetrical with respect to the LW cross section at the center of the longitudinal direction L of the multilayer ceramic capacitor 1. Therefore, when there is no need to particularly distinguish between the first external electrode 40A and the second external electrode 40B, the first external electrode 40A and the second external electrode 40B may be collectively referred to as the external electrodes 40. When there is no need to particularly distinguish between the first base electrode layer 50A and the second base electrode layer 50B, the first external electrode 40A and the second external electrode 40B may be collectively referred to as the base electrode layer 50. Furthermore, when it is not necessary to distinguish between the first conductive resin layer 60A and the second conductive resin layer 60B, the first conductive resin layer 60A and the second conductive resin layer 60B may be collectively referred to as the conductive resin layer 60. When it is not necessary to distinguish between the first plating layer 70A and the second plating layer 70B, the first plating layer 70A and the second plating layer 70B may be collectively referred to as the plating layer 70. When it is not necessary to distinguish between the first Ni plating layer 71A and the second Ni plating layer 71B, the first Ni plating layer 71A and the second Ni plating layer 71B may be collectively referred to as the Ni plating layer 71. When it is not necessary to distinguish between the first Sn plating layer 72A and the second Sn plating layer 72B, the first Sn plating layer 72A and the second Sn plating layer 72B may be collectively referred to as the Sn plating layer 72.

[0039] The base electrode layer 50 includes a first base electrode layer 50A and a second base electrode layer 50B.

[0040] The first base electrode layer 50A is disposed on the first end face LS1. The first base electrode layer 50A is connected to the first internal electrode layer 31. In this embodiment, the first base electrode layer 50A is formed to extend from the first end face LS1 to a portion of the first main surface TS1, a portion of the second main surface TS2, and a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0041] The second base electrode layer 50B is disposed on the second end face LS2. The second base electrode layer 50B is connected to the second internal electrode layer 32. In the embodiment, the second base electrode layer 50B is formed to extend from the second end face LS2 to a part of the first main surface TS1, a part of the second main surface TS2, a part of the first side surface WS1, and a part of the second side surface WS2.

[0042] The first base electrode layer 50A and the second base electrode layer 50B of the embodiment are firing layers. The firing layer preferably contains a metal component and either a glass component or a ceramic component, or both. This improves adhesion between the laminate 10 and the base electrode layer. The metal component includes at least one selected from, for example, Cu, Ni, Ag, Pd, an Ag-Pd alloy, and Au. The glass component includes at least one selected from, for example, B, Si, Ba, Mg, Al, and Li. The presence of a glass component can help sinter the metal component in the base electrode layer and promote sintering. The ceramic component may be the same ceramic material as that of the dielectric layer 20, or a different ceramic material. The ceramic component may include at least one selected from, for example, BaTiO3, CaTiO3, (Ba,Ca)TiO3, SrTiO3, and CaZrO3.

[0043] The baked layer is formed by, for example, applying a conductive paste containing glass and metal to the laminate and baking it. The baked layer may be formed by simultaneously firing a laminated chip having internal electrodes and a dielectric layer with a conductive paste applied to the laminated chip, or by simultaneously firing a laminated chip having internal electrodes and a dielectric layer to obtain a laminate and then applying a conductive paste to the laminate and baking it. When simultaneously firing a laminated chip having internal electrodes and a dielectric layer with a conductive paste applied to the laminated chip, it is preferable to form the baked layer by adding a ceramic material instead of a glass component and baking it. In this case, it is particularly preferable to use the same type of ceramic material as the dielectric layer 20 as the added ceramic material. The baked layer may be formed in multiple layers.

[0044] The thickness in the length direction L of the first base electrode layer 50A located on the first end surface LS1 is preferably, for example, approximately 2 μm or more and 220 μm or less at the center in the stacking direction T and width direction W of the first base electrode layer 50A.

[0045] The thickness in the length direction L of the second base electrode layer 50B located on the second end surface LS2 is preferably, for example, approximately 2 μm or more and 220 μm or less at the center in the stacking direction T and width direction W of the second base electrode layer 50B.

[0046] When the first base electrode layer 50A is provided on at least a portion of the first main surface TS1 or the second main surface TS2, the thickness in the stacking direction T of the first base electrode layer 50A provided on this portion is preferably, for example, approximately 3 μm or more and 40 μm or less at the center of the first base electrode layer 50A provided on this portion in the length direction L and width direction W.

[0047] When the first base electrode layer 50A is provided on a portion of at least one of the first side surface WS1 or the second side surface WS2, the widthwise thickness of the first base electrode layer 50A provided on this portion is preferably, for example, approximately 3 μm or more and 40 μm or less at the center of the first base electrode layer 50A provided on this portion in the length direction L and stacking direction T.

[0048] When the second base electrode layer 50B is provided on a portion of at least one of the first main surface TS1 or the second main surface TS2, the thickness in the stacking direction T of the second base electrode layer 50B provided on this portion is preferably, for example, approximately 3 μm or more and 40 μm or less at the center in the length direction L and width direction W of the second base electrode layer 50B provided on this portion.

[0049] When the second base electrode layer 50B is provided on a portion of at least one of the first side surface WS1 or the second side surface WS2, the widthwise thickness of the second base electrode layer 50B provided on this portion is preferably, for example, approximately 3 μm or more and 40 μm or less at the center in the length direction L and stacking direction T of the second base electrode layer 50B provided on this portion.

[0050] The external electrode 40 has a conductive resin layer 60 that is disposed on the base electrode layer 50 and contains a resin component and a metal component.

[0051] The conductive resin layer 60 includes a first conductive resin layer 60A and a second conductive resin layer 60B.

[0052] The first conductive resin layer 60A is disposed so as to cover the first base electrode layer 50A. In this embodiment, the first conductive resin layer 60A is formed to extend from the first end face LS1 to a portion of the first main surface TS1 and a portion of the second main surface TS2, as well as a portion of the first side surface WS1 and a portion of the second side surface WS2. The second conductive resin layer 60B is disposed so as to cover the second base electrode layer 50B. In this embodiment, the second conductive resin layer 60B is formed to extend from the second end face LS2 to a portion of the first main surface TS1 and a portion of the second main surface TS2, as well as a portion of the first side surface WS1 and a portion of the second side surface WS2. Here, the dimension of the first conductive resin layer 60A in the length direction L on the first main surface TS1 and the second main surface TS2 is shorter than the dimension of the first base electrode layer 50A in the length direction L on the first main surface TS1 and the second main surface TS2. Furthermore, the dimension in the length direction L on the first principal surface TS1 and the second principal surface TS2 of the second conductive resin layer 60B is shorter than the dimension in the length direction L on the first principal surface TS1 and the second principal surface TS2 of the second base electrode layer 50B.

[0053] The thickness in the longitudinal direction L of the first conductive resin layer 60A located on the first end face LS1 side is preferably, for example, approximately 5 μm or more and 200 μm or less at the center of the first conductive resin layer 60A in the stacking direction T and width direction W.

[0054] The thickness in the longitudinal direction L of the second conductive resin layer 60B located on the second end face LS2 side is preferably, for example, approximately 5 μm or more and 200 μm or less at the center of the second conductive resin layer 60B in the stacking direction T and width direction W.

[0055] When the first conductive resin layer 60A is provided on a portion of the first main surface TS1 side and a portion of the second main surface TS2 side, the thickness in the stacking direction T of the first conductive resin layer 60A provided on this portion is preferably, for example, approximately 5 μm or more and 200 μm or less at the center in the length direction L and width direction W of the first conductive resin layer 60A provided on this portion.

[0056] When the first conductive resin layer 60A is provided on a portion of the first side surface WS1 side and a portion of the second side surface WS2 side, the widthwise thickness of the first conductive resin layer 60A provided on this portion is preferably, for example, approximately 5 μm or more and 200 μm or less at the center in the length direction L and stacking direction T of the first conductive resin layer 60A provided on this portion.

[0057] When the second conductive resin layer 60B is provided on a portion of the first main surface TS1 side and a portion of the second main surface TS2 side, the thickness in the stacking direction T of the second conductive resin layer 60B provided on this portion is preferably, for example, approximately 5 μm or more and 200 μm or less at the center in the length direction L and width direction W of the second conductive resin layer 60B provided on this portion.

[0058] When the second conductive resin layer 60B is provided on a portion of the first side surface WS1 side and a portion of the second side surface WS2 side, the widthwise thickness of the second conductive resin layer 60B provided on this portion is preferably, for example, approximately 5 μm or more and 200 μm or less at the center in the length direction L and stacking direction T of the second conductive resin layer 60B provided on this portion.

[0059] The conductive resin layer 60 is disposed on the base electrode layer 50. Then, a plating layer 70 is disposed so as to cover the conductive resin layer 60 and a portion of the base electrode layer 50. The plating layer 70 has a Ni plating layer 71 and a Sn plating layer 72.

[0060] The conductive resin layer 60 has a resin portion as a resin component and a conductive filler as filler powder dispersed in the resin portion.

[0061] The resin portion of the conductive resin layer 60 may contain at least one selected from various known thermosetting resins, such as epoxy resin, phenoxy resin, phenolic resin, urethane resin, silicone resin, and polyimide resin. Among these, epoxy resin is one of the most suitable resins, due to its excellent heat resistance, moisture resistance, and adhesion. Furthermore, the resin portion of the conductive resin layer 60 preferably contains a curing agent in addition to the thermosetting resin. When an epoxy resin is used as the base resin, the curing agent for the epoxy resin may be any of various known compounds, such as phenolic, amine, acid anhydride, imidazole, active ester, and amide-imide compounds.

[0062] Because the conductive resin layer 60 contains such a resin portion, it is more flexible than the base electrode layer 50, which is made of, for example, a plating film or a fired product of a metal component and a glass component. Therefore, even when the multilayer ceramic capacitor 1 is subjected to a physical impact or an impact due to a thermal cycle, the conductive resin layer 60 functions as a buffer layer. Therefore, the conductive resin layer 60 suppresses the occurrence of cracks in the multilayer ceramic capacitor 1.

[0063] The conductive fillers are dispersed in a substantially uniform distribution within the resin portion. The conductive fillers are primarily responsible for the electrical conductivity of the conductive resin layer 60. Specifically, when multiple conductive fillers come into contact with each other, an electrical path is formed within the conductive resin layer 60, providing electrical continuity between the base electrode layer 50 and the plating layer 70.

[0064] The metal constituting the conductive filler may be Ag alone, an alloy containing Ag, or a metal powder with Ag coated on its surface. Ag has the lowest resistivity of all metals, making it suitable as an electrode material. Furthermore, Ag is a noble metal, so it is resistant to oxidation and highly weather-resistant. Therefore, Ag metal powder is suitable as a conductive filler. Furthermore, when using a metal powder with Ag coated on its surface, it is preferable to use Cu, Ni, Sn, Bi, or an alloy powder containing any of these metals as the metal powder.

[0065] Furthermore, the conductive filler may be Cu or Ni that has been subjected to an oxidation prevention treatment. The conductive filler may also be a metal powder in which the surface of the metal powder is coated with Sn, Ni, or Cu. When using a metal powder in which the surface of the metal powder is coated with Sn, Ni, or Cu, the metal powder is preferably Ag, Cu, Ni, Sn, Bi, or an alloy powder thereof. It is more preferable that the conductive filler has a core of Cu particles. It is also more preferable that at least a portion of the surface of the Cu particles is coated with a Cu-Ag alloy of Cu and Ag. At least a portion of the surface of the Cu particles may be coated with Ag. This improves affinity with Ni plating and improves electrical properties.

[0066] The shape of the conductive filler is not particularly limited. The conductive filler may be spherical, flat, or the like. It is preferable to use a mixture of spherical metal powder and flat metal powder. In other words, the conductive filler as the filler powder includes flat powder or spherical powder.

[0067] The average particle size of the conductive filler may be, for example, 0.3 μm or more and 10 μm or less.

[0068] The average particle size of the conductive filler contained in the conductive resin layer 60 is calculated by using a laser diffraction particle size measurement method based on ISO 13320, regardless of the shape of the conductive filler.

[0069] The plating layer 70 includes a first plating layer 70A and a second plating layer 70B.

[0070] The first plating layer 70A is disposed so as to cover the first conductive resin layer 60A and the first base electrode layer 50A. In the embodiment, the first plating layer 70A is disposed so as to extend from the first end face LS1 to a portion of the first main surface TS1, a portion of the second main surface TS2, and a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0071] The second plating layer 70B is disposed so as to cover the second conductive resin layer 60B and the second base electrode layer 50B. In the embodiment, the second plating layer 70B is disposed so as to extend from the first end face LS1 to a portion of the first main surface TS1, a portion of the second main surface TS2, and a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0072] The plating layer 70 preferably has a two-layer structure of a Ni plating layer 71 and a Sn plating layer 72. A first Sn plating layer 72A is preferably disposed on the first Ni plating layer 71A, and a second Sn plating layer 72B is preferably disposed on the second Ni plating layer 71B. The Ni plating layer 71 prevents the base electrode layer 50 and the conductive resin layer 60 from being eroded by solder when the multilayer ceramic capacitor 1 is mounted. The Sn plating layer 72 improves the wettability of the solder when the multilayer ceramic capacitor 1 is mounted. This makes it easier to mount the multilayer ceramic capacitor 1.

[0073] The thickness of each of the first Ni plated layer 71A and the first Sn plated layer 72A is preferably 1 μm or more and 15 μm or less.

[0074] The thickness of each of the second Ni plated layer 71B and the second Sn plated layer 72B is preferably 1 μm or more and 15 μm or less.

[0075] The above is the basic configuration of the multilayer ceramic capacitor 1 according to the embodiment. If the dimension in the length direction L of the multilayer ceramic capacitor 1 including the laminate 10 and the external electrodes 40 is defined as the L dimension, then the L dimension is preferably 0.2 mm or more and 10 mm or less. If the dimension in the stacking direction T of the multilayer ceramic capacitor 1 is defined as the T dimension, then the T dimension is preferably 0.05 mm or more and 10 mm or less. If the dimension in the width direction W of the multilayer ceramic capacitor 1 is defined as the W dimension, then the W dimension is preferably 0.1 mm or more and 10 mm or less.

[0076] The multilayer ceramic capacitor 1 of this embodiment having the above basic configuration has the following features in the external electrodes 40, that is, the first external electrode 40A and the second external electrode 40B.

[0077] The external electrode 40 of the embodiment includes a main surface-side external electrode arranged on at least one of the first main surface TS1 and the second main surface TS2. In detail, as described above, the first external electrode 40A of the embodiment is arranged on the first end face LS1 and extends from the first end face LS1 to part of the first main surface TS1 and part of the second main surface TS2, as well as part of the first side surface WS1 and part of the second side surface WS2. That is, as shown in Figures 2 and 4, the first external electrode 40A of the embodiment includes a first end face side external electrode 400A arranged on the first end face LS1, a first main surface side external electrode 411A as a main surface side external electrode arranged on the first main surface TS1, and a second main surface side external electrode 412A as a main surface side external electrode arranged on the second main surface TS2, and as shown in Figure 4, a first side face side external electrode 421A arranged on the first side face WS1 and a second side face side external electrode 422A arranged on the second side face WS2.

[0078] As described above, the first external electrode 40A includes a first base electrode layer 50A, a first conductive resin layer 60A disposed on the first base electrode layer 50A, and a first plating layer 70A disposed on the first conductive resin layer 60A. In the embodiment, the first base electrode layer 50A is formed to extend from the first end face LS1 to a portion of the first main surface TS1 and a portion of the second main surface TS2, as well as a portion of the first side surface WS1 and a portion of the second side surface WS2. The first conductive resin layer 60A is disposed so as to cover the first base electrode layer 50A, and the first plating layer 70A is disposed so as to cover the first conductive resin layer 60A.

[0079] 2 and 4, the first end face side external electrode 400A of the embodiment includes a first end face side base electrode layer 500A disposed on the first end face LS1, a first end face side conductive resin layer 600A formed above the first end face side base electrode layer 500A, and a first end face side plating layer 700A formed above the first end face side conductive resin layer 600A. The first end face side base electrode layer 500A is part of the first base electrode layer 50A. The first end face side conductive resin layer 600A is part of the first conductive resin layer 60A. The first end face side plating layer 700A is part of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A on the first Ni plating layer 71A.

[0080] 2, the first main surface side external electrode 411A of the embodiment includes a first main surface side base electrode layer 511A disposed on the first main surface TS1, a first main surface side conductive resin layer 611A formed above the first main surface side base electrode layer 511A, and a first main surface side plating layer 711A formed above the first main surface side conductive resin layer 611A. The first main surface side base electrode layer 511A is part of the first base electrode layer 50A. The first main surface side conductive resin layer 611A is part of the first conductive resin layer 60A. The first main surface side plating layer 711A is part of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A on the first Ni plating layer 71A.

[0081] 2, the second main surface side external electrode 412A of the embodiment includes a second main surface side base electrode layer 512A disposed on the second main surface TS2, a second main surface side conductive resin layer 612A formed above the second main surface side base electrode layer 512A, and a second main surface side plating layer 712A formed above the second main surface side conductive resin layer 612A. The second main surface side base electrode layer 512A is part of the first base electrode layer 50A. The second main surface side conductive resin layer 612A is part of the first conductive resin layer 60A. The second main surface side plating layer 712A is part of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A on the first Ni plating layer 71A.

[0082] 4, the first side surface side external electrode 421A of the embodiment includes a first side surface side base electrode layer 521A disposed on the first side surface WS1, a first side surface side conductive resin layer 621A formed above the first side surface side base electrode layer 521A, and a first side surface side plating layer 721A formed above the first side surface side conductive resin layer 621A. The first side surface side base electrode layer 521A is part of the first base electrode layer 50A. The first side surface side conductive resin layer 621A is part of the first conductive resin layer 60A. The first side surface side plating layer 721A is part of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A on the first Ni plating layer 71A.

[0083] 4, the second side surface side external electrode 422A of the embodiment includes a second side surface side base electrode layer 522A disposed on the second side surface WS2, a second side surface side conductive resin layer 622A formed above the second side surface side base electrode layer 522A, and a second side surface side plating layer 722A formed above the second side surface side conductive resin layer 622A. The second side surface side base electrode layer 522A is part of the first base electrode layer 50A. The second side surface side conductive resin layer 622A is part of the first conductive resin layer 60A. The second side surface side plating layer 722A is part of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A on the first Ni plating layer 71A.

[0084] The thickness of each of the first Ni plating layer 71A and the first Sn plating layer 72A of the above-mentioned first main surface side base electrode layer 511A, second main surface side base electrode layer 512A, first side surface side base electrode layer 521A and second side surface side base electrode layer 522A is preferably, for example, 5 μm or more and 10 μm or less.

[0085] The thickness of each of the first Ni plating layer 71A and the first Sn plating layer 72A of the above-mentioned first main surface side plating layer 711A, second main surface side plating layer 712A, first side surface side plating layer 721A and second side surface side plating layer 722A is preferably, for example, 1 μm or more and 4 μm or less.

[0086] As described above, the second external electrode 40B of the embodiment is disposed on the second end face LS2 and extends from the second end face LS2 to a part of the first main surface TS1 and a part of the second main surface TS2, and to a part of the first side surface WS1 and a part of the second side surface WS2. That is, the second external electrode 40B of the embodiment includes a second end face side external electrode 400B disposed on the first end face LS1, a first main surface side external electrode 411B as a main surface side external electrode disposed on the first main surface TS1, and a second main surface side external electrode 412B as a main surface side external electrode disposed on the second main surface TS2, as shown in Fig. 2, and a first side surface side external electrode 421B disposed on the first side surface WS1 and a second side surface side external electrode 422B disposed on the second side surface WS2, as shown in Fig. 4.

[0087] As described above, the second external electrode 40B includes a second base electrode layer 50B, a second conductive resin layer 60B disposed on the second base electrode layer 50B, and a second plating layer 70B disposed on the second conductive resin layer 60B. In the embodiment, the second base electrode layer 50B extends from the second end face LS2 to a portion of the first main surface TS1, a portion of the second main surface TS2, and a portion of the first side surface WS1, and a portion of the second side surface WS2. The second conductive resin layer 60B is disposed so as to cover the second base electrode layer 50B, and the second plating layer 70B is disposed so as to cover the second conductive resin layer 60B.

[0088] 2 and 4, the second end face side external electrode 400B of the embodiment includes a second end face side base electrode layer 500B disposed on the second end face LS2, a second end face side conductive resin layer 600B formed above the second end face side base electrode layer 500B, and a second end face side plating layer 700B formed above the second end face side conductive resin layer 600B. The second end face side base electrode layer 500B is part of the second base electrode layer 50B. The second end face side conductive resin layer 600B is part of the second conductive resin layer 60B. The second end face side plating layer 700B is part of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B on the second Ni plating layer 71B.

[0089] 2, the first main surface side external electrode 411B of the embodiment includes a first main surface side base electrode layer 511B disposed on the first main surface TS1, a first main surface side conductive resin layer 611B formed above the first main surface side base electrode layer 511B, and a first main surface side plating layer 711B formed above the first main surface side conductive resin layer 611B. The first main surface side base electrode layer 511B is part of the second base electrode layer 50B. The first main surface side conductive resin layer 611B is part of the second conductive resin layer 60B. The first main surface side plating layer 711B is part of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B on the second Ni plating layer 71B.

[0090] 2, the second main surface side external electrode 412B of the embodiment includes a second main surface side base electrode layer 512B disposed on the second main surface TS2, a second main surface side conductive resin layer 612B formed above the second main surface side base electrode layer 512B, and a second main surface side plating layer 712B formed above the second main surface side conductive resin layer 612B. The second main surface side base electrode layer 512B is part of the second base electrode layer 50B. The second main surface side conductive resin layer 612B is part of the second conductive resin layer 60B. The second main surface side plating layer 712B is part of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B on the second Ni plating layer 71B.

[0091] 4, the first side surface side external electrode 421B of the embodiment includes a first side surface side base electrode layer 521B disposed on the first side surface WS1, a first side surface side conductive resin layer 621B formed above the first side surface side base electrode layer 521B, and a first side surface side plating layer 721B formed above the first side surface side conductive resin layer 621B. The first side surface side base electrode layer 521B is part of the second base electrode layer 50B. The first side surface side conductive resin layer 621B is part of the second conductive resin layer 60B. The first side surface side plating layer 721B is part of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B on the second Ni plating layer 71B.

[0092] 4, the second side surface side external electrode 422B of the embodiment includes a second side surface side base electrode layer 522B disposed on the second side surface WS2, a second side surface side conductive resin layer 622B formed above the second side surface side base electrode layer 522B, and a second side surface side plating layer 722B formed above the second side surface side conductive resin layer 622B. The second side surface side base electrode layer 522B is part of the second base electrode layer 50B. The second side surface side conductive resin layer 622B is part of the second conductive resin layer 60B. The second side surface side plating layer 722B is part of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B on the second Ni plating layer 71B.

[0093] The thickness of each of the second Ni plating layer 71B and the second Sn plating layer 72B of the above-mentioned first main surface side base electrode layer 511B, second main surface side base electrode layer 512B, first side surface side base electrode layer 521B and second side surface side base electrode layer 522B is preferably, for example, 5 μm or more and 10 μm or less.

[0094] The thickness of the second Ni plating layer 71B and the thickness of the second Sn plating layer 72B of the above-mentioned first main surface side plating layer 711B, second main surface side plating layer 712B, first side surface side plating layer 721B and second side surface side plating layer 722B are preferably, for example, 1 μm or more and 4 μm or less.

[0095] Each of the above-described main surface side external electrodes 411A, 411B, 412A, and 412B has a main surface side step portion 800 as a step portion. Each of the above-described side surface side external electrodes 421A, 421B, 422A, and 422B has a side surface side step portion 900. These main surface side step portion 800 and side surface side step portion 900 will be described below.

[0096] 1B and 2, the first main surface side external electrode 411A of the first external electrode 40A has a first main surface side step 810A as the main surface side step 800. The first main surface side step 810A is formed approximately in the vicinity of the center in the longitudinal direction L of the surface 411sA of the first main surface side external electrode 411A. The first main surface side step 810A is a step that lowers the surface 411sA of the first main surface side external electrode 411A on the inside in the longitudinal direction L (toward the center of the laminate 10 in the longitudinal direction L) and raises the surface 411sA on the outside in the longitudinal direction L (toward the end surface LS of the laminate 10 in the longitudinal direction L). In other words, the height of the surface 411sA on the inside in the longitudinal direction L of the first main surface side step 810A is lower than the height of the surface 411sA on the outside in the longitudinal direction L of the first main surface side step 810A. The height here refers to the distance from the first principal surface TS1 to the surface 411sA in the stacking direction T. In this way, the surface 411sA of the first principal surface side external electrode 411A has a height difference caused by the first principal surface side step portion 810A so that the inside in the length direction L is lower and the outside in the length direction L is higher.

[0097] 1B, the first principal surface side stepped portion 810A has a curved shape that convexly extends inward in the length direction L. The first principal surface side stepped portion 810A extends across the width direction W on the surface 411sA of the first principal surface side external electrode 411A. In the embodiment, the first principal surface side stepped portion 810A is formed symmetrically in the width direction W with respect to a line F1 that extends along the length direction L through the center of the width direction W of the first principal surface side external electrode 411A, but strictly speaking, it does not have to be symmetrical. The radius of curvature of the curved first principal surface side stepped portion 810A is not limited, but is preferably 150 μm or more and 800 μm or less, for example.

[0098] As shown in FIGS. 1B and 2, the first principal surface side external electrode 411A has a first principal surface side edge 411eA at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. As shown in FIG. 1B, this first principal surface side edge 411eA has a curved shape that convexly curves inward in the length direction. In the embodiment, the first principal surface side edge 411eA is formed symmetrically in the width direction W with the line F1 as the line of symmetry, but strictly speaking, it does not have to be symmetrical. The curved shape of the first principal surface side edge 411eA is gentler than that of the first principal surface side stepped portion 810A and has a curvature that is closer to a straight line and smaller than that of the first principal surface side stepped portion 810A. The radius of curvature of the curved first principal surface side edge 411eA is not limited, but is preferably, for example, 800 μm to 10 mm.

[0099] The second main surface side external electrode 412A also has a main surface side step portion similar to the first main surface side external electrode 411A. As shown in Fig. 2, the second main surface side external electrode 412A of the first external electrode 40A has a second main surface side step portion 820A as the main surface side step portion 800. The second main surface side step portion 820A is formed approximately in the vicinity of the center in the length direction L of the surface 412sA of the second main surface side external electrode 412A. The second main surface side step portion 820A is a step that lowers the inner side in the length direction L of the surface 412sA of the second main surface side external electrode 412A and raises the outer side in the length direction L. That is, the height of the surface 412sA on the inner side in the length direction L of the second main surface side stepped portion 820A is lower than the height of the surface 412sA on the outer side in the length direction L of the second main surface side stepped portion 820A. The height here refers to the distance from the second main surface TS2 to the surface 412sA, which corresponds to the stacking direction T. In this way, the surface 412sA of the second main surface side external electrode 412A is given a difference in height by the second main surface side stepped portion 820A, so that the inner side in the length direction L is lower and the outer side in the length direction L is higher.

[0100] Although not shown in the figures, the second main surface side step portion 820A, like the first main surface side step portion 810A, has a curved shape that convexly extends toward the center in the length direction L. The second main surface side step portion 820A extends across the width direction W on the surface 412sA of the second main surface side external electrode 412A. Although the second main surface side step portion 820A in the embodiment is also formed symmetrically in the width direction W, it does not have to be symmetrical in the strict sense. The radius of curvature of the curved second main surface side step portion 820A is not limited, but is preferably, for example, 150 μm or more and 800 μm or less.

[0101] As shown in FIG. 2 , the second principal surface side external electrode 412A has a second principal surface side edge 412eA at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. Like the first principal surface side edge 411eA, this second principal surface side edge 412eA also has a curved shape that convexly extends inward in the length direction. In the embodiment, the second principal surface side edge 412eA is also formed symmetrically in the width direction W, but strictly speaking, symmetry is not required. The curved shape of the second principal surface side edge 412eA is gentler than the second principal surface side stepped portion 820A and has a curvature that is closer to a straight line and smaller than that of the second principal surface side stepped portion 820A. The radius of curvature of the curved second principal surface side edge 412eA is not limited, but is preferably, for example, between 800 μm and 10 mm.

[0102] 1B and 2, the first main surface side external electrode 411B of the second external electrode 40B has a first main surface side step 810B as the main surface side step 800. The first main surface side step 810B is formed approximately in the center of the length direction L of the surface 411sB of the first main surface side external electrode 411B. The first main surface side step 810B is a step that lowers the inside of the surface 411sB of the first main surface side external electrode 411B in the length direction L and raises the outside of the surface 411sB in the length direction L. In other words, the height of the surface 411sB on the inside of the first main surface side step 810B in the length direction L is lower than the height of the surface 411sB on the outside of the first main surface side step 810B in the length direction L. The height here refers to the distance corresponding to the stacking direction T from the first main surface TS1 to the surface 411sB. In this way, the surface 411sB of the first main surface side external electrode 411B is provided with a height difference such that the inside in the length direction L is lower and the outside in the length direction L is higher due to the first main surface side step portion 810B.

[0103] 1B, the first main surface side stepped portion 810B has a curved shape that convexly extends inward in the length direction L. The first main surface side stepped portion 810B extends across the width direction W on the surface 411sB of the first main surface side external electrode 411B. In the embodiment, the first main surface side stepped portion 810B is formed symmetrically in the width direction W with respect to a line F2 that extends along the length direction L through the center of the width direction W of the first main surface side external electrode 411B, but strictly speaking, it does not have to be symmetrical. The radius of curvature of the curved first main surface side stepped portion 810B is not limited, but is preferably 150 μm or more and 800 μm or less, for example.

[0104] As shown in FIGS. 1B and 2, the first principal surface side external electrode 411B has a first principal surface side edge 411eB at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. As shown in FIG. 1B, this first principal surface side edge 411eB has a curved shape that convexly curves inward in the length direction. In the embodiment, the first principal surface side edge 411eB is formed symmetrically in the width direction W with the line F2 as the line of symmetry, but strictly speaking, it does not have to be symmetrical. The curved shape of the first principal surface side edge 411eB is gentler than that of the first principal surface side stepped portion 810B and has a curvature that is closer to a straight line and smaller than that of the first principal surface side stepped portion 810B. The radius of curvature of the curved first principal surface side edge 411eB is not limited, but is preferably, for example, 800 μm to 10 mm.

[0105] The second main surface side external electrode 412B also has a main surface side step portion similar to the first main surface side external electrode 411B. As shown in Fig. 2, the second main surface side external electrode 412B of the second external electrode 40B has a second main surface side step portion 820B as the main surface side step portion 800. The second main surface side step portion 820B is formed approximately in the vicinity of the center in the length direction L of the surface 412sB of the second main surface side external electrode 412B. The second main surface side step portion 820B is a step that lowers the inner side in the length direction L of the surface 412sB of the second main surface side external electrode 412B and raises the outer side in the length direction L. That is, the height of the surface 412sB on the inside in the length direction L of the second main surface side stepped portion 820B is lower than the height of the surface 412sB on the outside in the length direction L of the second main surface side stepped portion 820B. The height here refers to the distance from the second main surface TS2 to the surface 412sB, which corresponds to the stacking direction T. In this way, the surface 412sB of the second main surface side external electrode 412B is given a difference in height by the second main surface side stepped portion 820B so that the inside in the length direction L is lower and the outside in the length direction L is higher.

[0106] Although not shown in the figures, the second main surface side step portion 820B, like the first main surface side step portion 810B, has a curved shape that convex toward the center in the length direction L. The second main surface side step portion 820B extends across the width direction W on the surface 412sB of the second main surface side external electrode 412B. Although the second main surface side step portion 820B in the embodiment is also formed symmetrically in the width direction W, it does not have to be symmetrical in the strict sense. The radius of curvature of the curved second main surface side step portion 820B is not limited, but is preferably, for example, 150 μm or more and 800 μm or less.

[0107] As shown in FIG. 2 , the second principal surface side external electrode 412B has a second principal surface side edge 412eB at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. Like the first principal surface side edge 411eB, this second principal surface side edge 412eB also has a curved shape that convexly extends inward in the length direction. In the embodiment, the second principal surface side edge 412eB is also formed symmetrically in the width direction W, but strictly speaking, it does not have to be symmetrical. The curved shape of the second principal surface side edge 412eB is gentler than the second principal surface side stepped portion 820B and has a curvature that is closer to a straight line and smaller than that of the second principal surface side stepped portion 820B. The radius of curvature of the curved second principal surface side edge 412eB is not limited, but is preferably, for example, between 800 μm and 10 mm.

[0108] 1C and 4, the second side surface side external electrode 422A of the first external electrode 40A has a second side surface side step portion 920A as the side surface side step portion 900. The second side surface side step portion 920A has a configuration similar to that of each of the above-mentioned main surface side step portions 810A, 820A, 810B, and 820B. The second side surface side step portion 920A is formed approximately near the center in the length direction L of the surface 422sA of the second side surface side external electrode 422A. The second side surface side step portion 920A is a step that lowers the inner side in the length direction L of the surface 422sA of the second side surface side external electrode 422A and raises the outer side in the length direction L. That is, the height of the surface 422sA on the inner side of the second side surface side step portion 920A in the length direction L is lower than the height of the surface 422sA on the outer side of the second side surface side step portion 920A in the length direction L. The height here refers to the distance corresponding to the width direction W from the second side surface WS2 to the surface 422sA. In this way, the surface 422sA of the second side surface side external electrode 422A is given a difference in height by the second side surface side step portion 920A so that the inner side in the length direction L is lower and the outer side in the length direction L is higher.

[0109] 1C, the second side surface side step portion 920A has a curved shape that convexly extends inward in the length direction L. The second side surface side step portion 920A extends in the stacking direction T on the surface 422sA of the second side surface side external electrode 422A. In the embodiment, the second side surface side step portion 920A is formed symmetrically in the stacking direction T with respect to a line F3 that extends along the length direction L through the center of the second side surface side external electrode 422A in the stacking direction T, but strictly speaking, the symmetry is not required. The radius of curvature of the curved second side surface side step portion 920A is not limited, but is preferably 150 μm or more and 800 μm or less, for example.

[0110] As shown in FIGS. 1C and 4, the second side surface side external electrode 422A has a second side surface side edge 422eA at its inner end in the length direction L, as the edge that serves as the inner terminal edge in the length direction L. As shown in FIG. 1C, this second side surface side edge 422eA has a curved shape that convexly curves inward in the length direction. In the embodiment, the second side surface side edge 422eA is formed symmetrically in the stacking direction T with the line F3 as the line of symmetry, but strictly speaking, it does not have to be symmetrical. The curved shape of the second side surface side edge 422eA is gentler than that of the second side surface side step portion 920A and has a curvature that is closer to a straight line and smaller than that of the second side surface side step portion 920A. The radius of curvature of the curved second side surface side edge 422eA is not limited, but is preferably, for example, 800 μm to 10 mm.

[0111] The second side surface side step portion 920A may be continuous with either or both of the above-mentioned first main surface side step portion 810A and second main surface side step portion 820A, or it does not have to be continuous with both.

[0112] The first side surface side external electrode 421A also has a side surface side step portion similar to the second side surface side external electrode 422A. As shown in FIG. 4, the first side surface side external electrode 421A of the first external electrode 40A has a first side surface side step portion 910A as the side surface side step portion 900. The first side surface side step portion 910A is formed approximately near the center in the longitudinal direction L of the surface 421sA of the first side surface side external electrode 421A. The first side surface side step portion 910A is a step that lowers the inner side in the longitudinal direction L of the surface 421sA of the first side surface side external electrode 421A and raises the outer side in the longitudinal direction L. In other words, the height of the surface 421sA on the inner side in the longitudinal direction L than the first side surface side step portion 910A is lower than the height of the surface 421sA on the outer side in the longitudinal direction L than the first side surface side step portion 910A. The height here refers to the distance from the first side surface WS1 to the surface 421sA in the width direction W. In this way, the surface 421sA of the first side surface side external electrode 421A has a height difference caused by the first side surface side step portion 910A so that the inside in the length direction L is lower and the outside in the length direction L is higher.

[0113] Although not shown in the figures, the first side surface side step portion 910A, like the second side surface side step portion 920A, has a curved shape that convex toward the center in the length direction L. The first side surface side step portion 910A extends across the width direction W on the surface 421sA of the first side surface side external electrode 421A. The first side surface side step portion 910A in the embodiment is also formed symmetrically with respect to the stacking direction T, but strictly speaking, it does not have to be symmetrical. The radius of curvature of the curved first side surface side step portion 910A is not limited, but is preferably, for example, 150 μm or more and 800 μm or less.

[0114] As shown in FIG. 4 , the first side surface side external electrode 421A has a first side surface side edge 421eA at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. Like the second side surface side edge 422eA, this first side surface side edge 421eA also has a curved shape that convexly extends inward in the length direction. In the embodiment, the first side surface side edge 421eA is also formed symmetrically with respect to the stacking direction T, but strictly speaking, symmetry is not required. The curved shape of the first side surface side edge 421eA is gentler than that of the first side surface side step portion 910A and has a curvature that is closer to a straight line and smaller than that of the first side surface side step portion 910A. The radius of curvature of the curved first side surface side edge 421eA is not limited, but is preferably, for example, between 800 μm and 10 mm.

[0115] The first side surface side step portion 910A may be continuous with either or both of the above-mentioned first main surface side step portion 810A and second main surface side step portion 820A, or it does not have to be continuous with both.

[0116] As shown in FIGS. 1C and 4, the second side surface side external electrode 422B of the second external electrode 40B has a second side surface side step 920B as the side surface side step 900. The second side surface side step 920B is formed approximately near the center in the longitudinal direction L of the surface 422sB of the second side surface side external electrode 422B. The second side surface side step 920B is a step that lowers the inner side in the longitudinal direction L of the surface 422sB of the second side surface side external electrode 422B and raises the outer side in the longitudinal direction L. In other words, the height of the surface 422sB on the inner side in the longitudinal direction L of the second side surface side step 920B is lower than the height of the surface 422sB on the outer side in the longitudinal direction L of the second side surface side step 920B. The height here refers to the distance corresponding to the width direction W from the second side surface WS2 to the surface 422sB. In this way, the surface 422sB of the second side surface side external electrode 422B is provided with a height difference such that the inside in the length direction L is lower and the outside in the length direction L is higher due to the second side surface side step portion 920B.

[0117] As shown in FIG. 1C , the second side surface side step portion 920B has a curved shape that convexly extends inward in the length direction L. The second side surface side step portion 920B extends across the width direction W on the surface 422sB of the second side surface side external electrode 422B. In the embodiment, the second side surface side step portion 920B is formed symmetrically in the stacking direction T with respect to a line F4 that extends along the length direction L through the center of the width direction W of the second side surface side external electrode 422B as the line of symmetry, but strictly speaking, the symmetry is not required. The radius of curvature of the curved second side surface side step portion 920B is not limited, but is preferably 150 μm or more and 800 μm or less, for example.

[0118] As shown in FIGS. 1C and 4, the second side surface side external electrode 422B has a second side surface side edge 422eB at its inner end in the length direction L, serving as the end edge on the inner side in the length direction L. This second side surface side edge 422eB has a curved shape that convexly curves inward in the length direction, as shown in FIG. 1C. In the embodiment, the second side surface side edge 422eB is formed symmetrically in the stacking direction T with the line F4 as the line of symmetry, but strictly speaking, it does not have to be symmetrical. The curved shape of the second side surface side edge 422eB is gentler than that of the second side surface side step portion 920B and has a curvature that is closer to a straight line and smaller than that of the second side surface side step portion 920B. The radius of curvature of the curved second side surface side edge 422eB is not limited, but is preferably, for example, 800 μm to 10 mm.

[0119] The second side surface side step portion 920B may be continuous with either or both of the above-mentioned first main surface side step portion 810B and second main surface side step portion 820B, or it does not have to be continuous with both.

[0120] The first side surface side external electrode 421B also has a side surface side step portion similar to the second side surface side external electrode 422B. As shown in FIG. 4, the first side surface side external electrode 421B of the second external electrode 40B has a first side surface side step portion 910B as the side surface side step portion 900. The first side surface side step portion 910B is formed approximately near the center in the longitudinal direction L of the surface 421sB of the first side surface side external electrode 421B. The first side surface side step portion 910B is a step that lowers the inner side in the longitudinal direction L of the surface 421sB of the first side surface side external electrode 421B and raises the outer side in the longitudinal direction L. In other words, the height of the surface 421sB on the inner side in the longitudinal direction L of the first side surface side step portion 910B is lower than the height of the surface 421sB on the outer side in the longitudinal direction L of the first side surface side step portion 910B. The height here refers to the distance from the first side surface WS1 to the surface 421sB in the width direction W. In this way, the surface 421sB of the first side surface side external electrode 421B has a height difference caused by the first side surface side step portion 910B so that the inside in the length direction L is lower and the outside in the length direction L is higher.

[0121] Although not shown in the figures, the first side surface side step portion 910B, like the second side surface side step portion 920B, has a curved shape that convex toward the center in the length direction L. The first side surface side step portion 910B extends in the stacking direction T on the surface 421sB of the first side surface side external electrode. The first side surface side step portion 910B in the embodiment is also formed symmetrically in the stacking direction, but does not have to be symmetrical in the strict sense. The radius of curvature of the curved first side surface side step portion 910B is not limited, but is preferably, for example, 150 μm or more and 800 μm or less.

[0122] As shown in FIG. 4, the first side surface step portion 910B has a first side surface edge 421eB at its inner end in the length direction L, serving as the edge that terminates on the inner side in the length direction L. Like the second side surface edge 422eB, this first side surface edge 421eB also has a curved shape that convexly extends inward in the length direction. In the embodiment, the first side surface edge 421eB is also formed symmetrically with respect to the stacking direction T, but this does not necessarily have to be strictly symmetrical. The curved shape of the first side surface edge 421eB is gentler than that of the first side surface step portion 910B and has a curvature that is closer to a straight line and smaller than that of the first side surface step portion 910B. The radius of curvature of the curved first side surface edge 421eB is not limited, but is preferably, for example, between 800 μm and 10 mm.

[0123] The first side surface side step portion 910B may be continuous with either or both of the above-mentioned first main surface side step portion 810B and second main surface side step portion 820B, or it does not have to be continuous with both.

[0124] The above-mentioned main surface-side stepped portions 800 and side surface-side stepped portions 900 will be described in further detail. The first main surface-side external electrode 411A and the second main surface-side external electrode 412A of the first external electrode 40A and the first main surface-side external electrode 411B and the second main surface-side external electrode 412B of the second external electrode 40B have the same configuration. Furthermore, the first side surface-side external electrode 421A and the second side surface-side external electrode 422A of the first external electrode 40A and the first side surface-side external electrode 421B and the second side surface-side external electrode 422B of the second external electrode 40B also have the same configuration as the above-mentioned four main surface-side external electrodes 411A, 412A, 411B, 412B.

[0125] The main surface-side step portions 800 of the first external electrode 40A, i.e., the first main surface-side step portion 810A and the second main surface-side step portion 820A, and the first main surface-side step portion 810B and the second main surface-side step portion 820B of the second external electrode 40B, have the same configuration. Furthermore, the side surface-side step portions 900 of the first external electrode 40A, i.e., the first side surface-side step portion 910A and the second side surface-side step portion 920A, and the first side surface-side step portion 910B and the second side surface-side step portion 920B of the second external electrode 40B, also have the same configuration as the four main surface-side step portions 810A, 820A, 810B, 820B.

[0126] Therefore, the first main surface side external electrode 411A and the first main surface side step portion 810A of the first external electrode 40A will be described below as representative of these four main surface side external electrodes and main surface side step portions 800, and these four side surface side external electrodes and side surface side step portions 900, thereby explaining the four main surface side external electrodes and main surface side step portions 800, and the four side surface side external electrodes and side surface side step portions 900.

[0127] The first main surface side external electrode 411A of the first external electrode 40A corresponds to the second main surface side external electrode 412A, the first side surface side external electrode 421A, and the second side surface side external electrode 422A of the first external electrode 40A, and the first main surface side external electrode 411B, the second main surface side external electrode 412B, the first side surface side external electrode 421B, and the second side surface side external electrode 422B of the second external electrode 40B. The first main surface side step portion 810A of the first external electrode 40A corresponds to the second main surface side step portion 820A, the first side surface side step portion 910A, and the second side surface side step portion 920A of the first external electrode 40A, and the first main surface side step portion 810B, the second main surface side step portion 820B, the first side surface side step portion 910B, and the second side surface side step portion 920B of the second external electrode 40B.

[0128] The first base electrode layer 50A, the first conductive resin layer 60A, and the first plating layer 70A of the first external electrode 40A correspond to the second base electrode layer 50B, the second conductive resin layer 60B, and the second plating layer 70B of the second external electrode 40B. The first Ni plating layer 71A and the first Sn plating layer 72A of the first plating layer 70A of the first external electrode 40A correspond to the second Ni plating layer 71B and the second Sn plating layer 72B of the second plating layer 70B of the second external electrode 40B.

[0129] Fig. 5 is an enlarged view of the portion indicated by V in Fig. 2, and is an LT cross-sectional view showing the first main surface side external electrode 411A of the first external electrode 40A. Fig. 5 also shows an XYZ Cartesian coordinate system similar to Figs. 1A to 4. In Fig. 5, hatching is omitted to clearly show the symbols, symbol leads, and dimension lines.

[0130] As shown in FIG. 5, the first main surface side external electrode 411A of the first external electrode 40A has a first main surface side base electrode layer 511A and a first main surface side conductive resin layer 611A arranged on the first main surface TS1, and a first main surface side plating layer 711A including a first Ni plating layer 71A and a first Sn plating layer 72A.

[0131] As described above, the surface 411sA of the first main surface side external electrode 411A is provided with a difference in height by the first main surface side step portion 810A so that the inside in the length direction L is lower and the outside in the length direction L is higher. That is, the first main surface side external electrode 411A includes the first main surface side step portion 810A, an inner thin portion 81 located inside the first main surface side step portion 810A in the length direction L (toward the center of the laminate 10 in the length direction L), and an outer thick portion 82 located outside the first main surface side step portion 810A in the length direction L. The surface 411sA of the first main surface side external electrode 411A includes a surface 81s of the inner thin portion 81, a surface 82s of the outer thick portion 82, and a surface 83s of the first main surface side step portion 810A.

[0132] The outer thick portion 82 and the first main surface side stepped portion 810A include a first main surface side base electrode layer 511A, a first main surface side conductive resin layer 611A, and a first main surface side plating layer 711A. The inner thin portion 81 includes a first main surface side base electrode layer 511A and a first main surface side plating layer 711A. Specifically, the outer thick portion 82 and the first main surface side stepped portion 810A are composed of the first main surface side base electrode layer 511A, the first main surface side conductive resin layer 611A disposed on the first main surface side base electrode layer 511A, and the first main surface side plating layer 711A disposed on the first main surface side conductive resin layer 611A. The inner thin portion 81 includes a first main surface side base electrode layer 511A and a first main surface side plating layer 711A disposed directly on the first main surface side base electrode layer 511A. Therefore, in the inner thin portion 81 located more inward in the longitudinal direction L than the first main surface side stepped portion 810A, the first main surface side plating layer 711A is disposed on the first main surface side base electrode layer 511A, and the first main surface side conductive resin layer 611A is not disposed.

[0133] The distance corresponding to the stacking direction T from the first main surface TS1 of the laminate 10 to the surface 81s of the inner thin portion 81 is the height (thickness) 81H of the inner thin portion 81. The distance corresponding to the stacking direction T from the first main surface TS1 to the surface 82s of the outer thick portion 82 is the height (thickness) 82H of the outer thick portion 82. The maximum height 81H of the inner thin portion 81 is smaller than the maximum height H of the outer thick portion 82.

[0134] The surface 83s of the first main surface side stepped portion 810A connects the surface 82s of the outer thick portion 82 and the surface 81s of the inner thin portion 81, and is inclined toward the first main surface TS1 from the outside toward the inside in the longitudinal direction L. The thickness of the step of the first main surface side stepped portion 810A, i.e., the step amount D formed between the outer end 84e and the inner end 85e of the first main surface side stepped portion 810A in the longitudinal direction L, is not limited, but is preferably, for example, 3 μm to 40 μm. Furthermore, the step amount D is preferably 5% to 60% of the maximum thickness of the first main surface side external electrode 411A, i.e., the maximum thickness of the outer thick portion 82. The step amount D is preferably greater than the thickness of the first Ni plating layer 71A.

[0135] As described above, the first principal surface side conductive resin layer 611A is not disposed in the inner thin portion 81, and its inner end 611e is located at the same position as the inner end 85e of the first principal surface side stepped portion 810A in the longitudinal direction L, or on the outer side (toward the first end face LS1). The inner end 511e of the first principal surface side base electrode layer 511A is located more inward in the longitudinal direction L (toward the center of the laminate 10) than the inner end 85e of the first principal surface side stepped portion 810A. Therefore, the length 511L in the longitudinal direction L from the first end face LS1 to the inner end 511e of the first principal surface side base electrode layer 511A is longer than the length 611L in the longitudinal direction L from the first end face LS1 to the inner end 611e of the first principal surface side conductive resin layer 611A.

[0136] In the embodiment, the thickness H3 of the first main surface plating layer 711A of the thin portion 81 is preferably greater than the thickness H4 of the first main surface plating layer 711A of the outer thick portion .

[0137] The multilayer ceramic capacitor 1 of the embodiment is mounted on a substrate. Mounting on the substrate may involve soldering the external electrodes 40 to terminals of the substrate. When the first main surface side external electrode 411A is soldered to the substrate, flexural stress generated in the first main surface side external electrode 411A is transmitted to the laminate 10, potentially causing cracks in the laminate 10. In the multilayer ceramic capacitor 1 of the embodiment, the first main surface side external electrode 411A has a curved first main surface side step 810A that is convex toward the inside (center) of the length direction L of the laminate 10. This makes it easier for the flexural stress to be uniformly maintained at the interface between the first main surface side external electrode 411A and the laminate 10 and to be dispersed to the first main surface side step 810A or the periphery of the first main surface side step 810A. This improves flexural resistance and suppresses cracks in the laminate 10. This also applies to the other main surface side external electrodes and side surface side electrodes.

[0138] In the multilayer ceramic capacitor 1 of the embodiment, as described above, when the first main surface side external electrode 411A is viewed, the curved shape of the first main surface side edge 411eA is gentler than that of the first main surface side stepped portion 810A and has a curvature closer to a straight line than that of the first main surface side stepped portion 810A. This makes it easier for the above-mentioned bending stress generated during mounting on a substrate to be uniformly maintained at the interface between the first main surface side external electrode 411A and the laminate 10 and to be dispersed to the first main surface side stepped portion 810A or the periphery of the first main surface side stepped portion 810A. This improves bending resistance and suppresses the occurrence of cracks in the laminate 10. The same applies to the other main surface side external electrodes and side surface side electrodes.

[0139] In the multilayer ceramic capacitor 1 of the embodiment, as described above, when viewing the first main surface side external electrode 411A, the first main surface side conductive resin layer 611A is not disposed in the inner thin portion 81 that is located inside the first main surface side stepped portion 810A in the longitudinal direction L, and the inner end 611e of the first main surface side conductive resin layer 611A is located at the same position as the inner end 85e of the first main surface side stepped portion 810A in the longitudinal direction L or outside. This reduces the amount of the first main surface side conductive resin layer 611A, thereby preventing an increase in the size of the first external electrode 40A. Furthermore, in the inner thin portion 81, a region is formed where the first main surface side base electrode layer 511A and the first main surface side plating layer 711A are directly connected without the first main surface side conductive resin layer 611A being interposed therebetween. This reduces electrical resistance even in a configuration that includes a conductive resin layer. This also applies to the other main surface side external electrodes and side surface side electrodes.

[0140] As described above, in the multilayer ceramic capacitor 1 of the embodiment, when considering the first main surface side external electrode 411A, the thickness H3 of the first main surface side plating layer 711A in the thin portion 81 is preferably greater than the thickness H4 of the first main surface side plating layer 711A in the outer thick portion 82. In this case, the compressive stress due to the plating is increased, improving the resistance to deflection. Cracks due to deflection of the laminate 10 occur when stress is applied to the side of the laminate 10 that is pulled in the longitudinal direction L. If the plating layer has compressive stress as residual stress, the compressive stress due to the plating is stress in the opposite direction to the stress on the side that is pulled. Therefore, the increased compressive stress due to the plating improves the resistance to deflection. Furthermore, the formation of thick plating portions improves board mountability. This also applies to the other main surface side external electrodes and side surface side electrodes. On the other hand, a relatively thin thickness H4 is preferable because it directly affects the overall dimensions of the multilayer ceramic capacitor 1.

[0141] The above-described dimensions, such as the thickness of each layer constituting the first principal surface side external electrode 411A and the step amount D of the first principal surface side stepped portion 810A, are measured, for example, by the following method. That is, the multilayer ceramic capacitor 1 is polished from the first side surface WS1 or the second side surface WS2 to a position approximately half the dimension in the width direction W. This exposes the LT cross section at the center position in the width direction W of the multilayer ceramic capacitor 1. Next, a digital microscope is used to measure the above-described dimensions of the LT cross section exposed by polishing.

[0142] Next, a method for manufacturing the multilayer ceramic capacitor 1 of the embodiment will be described. The method for manufacturing the multilayer ceramic capacitor 1 of the embodiment is not limited as long as it satisfies the above-mentioned requirements. However, a suitable manufacturing method includes the following steps. Each step will be described in detail below.

[0143] A dielectric sheet for the dielectric layer 20 and a conductive paste for the internal electrode layer 30 are prepared. The dielectric sheet and the conductive paste for the internal electrode contain a binder and a solvent. The binder and the solvent may be known.

[0144] On the dielectric sheets, a conductive paste for the internal electrode layers 30 is printed in a predetermined pattern by, for example, screen printing, gravure printing, etc. In this way, a dielectric sheet on which the pattern of the first internal electrode layer 31 is formed and a dielectric sheet on which the pattern of the second internal electrode layer 32 is formed are prepared.

[0145] A predetermined number of dielectric sheets without a printed internal electrode layer pattern are stacked to form a portion that will become the first main surface-side outer layer portion 12A on the first main surface TS1 side. A dielectric sheet with a printed first internal electrode layer pattern and a dielectric sheet with a printed second internal electrode layer pattern are stacked in this order on top of that to form a portion that will become the internal layer portion 11. A predetermined number of dielectric sheets without a printed internal electrode layer pattern are stacked on top of this portion that will become the internal layer portion 11 to form a portion that will become the second main surface-side outer layer portion 12B on the second main surface TS2 side. In this way, a laminated sheet is produced.

[0146] The laminated sheets are pressed in the lamination direction by means of a hydrostatic press or the like to produce a laminated block.

[0147] The laminated block is cut to a predetermined size to cut out laminated chips, and at this time, corners and ridges of the laminated chips may be rounded by barrel polishing or the like.

[0148] The laminated chip is fired to produce the laminate 10. The firing temperature depends on the materials of the dielectric layers 20 and the internal electrode layers 30, but is preferably 900°C or higher and 1400°C or lower.

[0149] A conductive paste that will become the base electrode layer 50 is applied to both end surfaces of the laminate 10. In this embodiment, the base electrode layer 50 is a baked layer. A conductive paste containing a glass component and a metal is applied to the laminate 10 by a method such as dipping. A baking process is then performed to form the base electrode layer 50. The temperature for the baking process at this time is preferably 700°C or higher and 950°C or lower.

[0150] In this embodiment, dipping is performed so that the first base electrode layer 50A extends from the first end face LS1 to parts of the first main surface TS1 and the second main surface TS2. Also, dipping is performed so that the second base electrode layer 50B extends from the second end face LS2 to parts of the first main surface TS1 and the second main surface TS2. At the same time, dipping is preferably performed so that the first base electrode layer 50A extends to parts of the first side surface WS1 and the second side surface WS2. Also, dipping is preferably performed so that the second base electrode layer 50B extends to parts of the first side surface WS1 and the second side surface WS2.

[0151] The laminated chip before firing and the conductive paste applied to the laminated chip may be fired simultaneously. In this case, the fired layer is preferably formed by firing a material containing a ceramic material instead of a glass component. In this case, it is particularly preferable to use the same type of ceramic material as the dielectric layer 20 as the ceramic material added. In this case, the conductive paste is applied to the laminated chip before firing, and the laminated chip and the conductive paste applied to the laminated chip are fired simultaneously to form the laminate 10 with the fired layer formed.

[0152] Next, the conductive resin layer 60 is formed. The conductive resin layer 60 of the embodiment is formed on the surface of the base electrode layer 50.

[0153] First, a conductive resin paste is prepared by dispersing conductive fillers in a thermosetting resin as a base resin for the resin portion. This conductive resin paste is produced by stirring and mixing the thermosetting resin and conductive fillers. Therefore, the conductive fillers are uniformly dispersed within the conductive resin paste. Here, the thermosetting resin is, for example, an epoxy resin. The conductive filler is, for example, Ag metal powder.

[0154] Thereafter, a conductive resin paste is applied onto the base electrode layer 50 using a dipping method, and a heat treatment is performed at a temperature of 200°C to 550°C. This causes the resin portion to thermally harden, forming the conductive resin layer 60. The atmosphere during this heat treatment is preferably an N2 atmosphere. Furthermore, to prevent the resin from scattering and the various metal components from oxidizing, it is preferable that the oxygen concentration be kept below 100 ppm.

[0155] In this embodiment, dipping is performed so that the first conductive resin layer 60A extends from the first end face LS1 to parts of the first main surface TS1 and the second main surface TS2. Also, dipping is performed so that the second conductive resin layer 60B extends from the second end face LS2 to parts of the first main surface TS1 and the second main surface TS2. At the same time, dipping is preferably performed so that the first conductive resin layer 60A extends to parts of the first side face WS1 and the second side face WS2. Also, dipping is preferably performed so that the second conductive resin layer 60B extends to parts of the first side face WS1 and the second side face WS2.

[0156] Thereafter, a plating layer 70 is formed on the surface of the conductive resin layer 60. In this embodiment, a Ni plating layer 71 and a Sn plating layer 72 are formed on the conductive resin layer 60. The Ni plating layer 71 and the Sn plating layer 72 are formed in this order using an electrolytic plating method. As the plating method, for example, barrel plating is preferably used.

[0157] Here, in order to obtain the above-mentioned step portions in each of the main surface side external electrodes and each of the side surface side external electrodes of the external electrode 40 as in the embodiment, for example, the following method can be mentioned.

[0158] 6A and 6B schematically illustrate steps for forming the base electrode layer 50 and the conductive resin layer 60 in this method. As shown in FIG. 6A, a base electrode paste 50P that will become the base electrode layer 50 is applied by dipping to an end portion of the laminate 10 in the longitudinal direction L. Next, a conductive resin paste 60P that will become the conductive resin layer 60 is applied by dipping. The conductive resin paste 60P is applied shallower than the base electrode paste 50P. As a result, a step G is formed near the end portion of the conductive resin paste 60P. This step G becomes the main surface-side step portion 800 and the side surface-side step portion 900 described above. After this, a Ni plating layer 71 and a Sn plating layer 72 are formed. The Ni plating layer 71 and the Sn plating layer 72 are formed sequentially using electrolytic plating. For example, barrel plating is preferably used as the plating method.

[0159] It is also possible to form a stepped portion by appropriately adjusting the viscosity of the base electrode paste 50P and the conductive resin paste 60P, controlling the surface roughness of the base electrode layer 50, or devising a dipping method. Furthermore, the above-mentioned dipping forms a surface in which the base electrode layer 50 is exposed from the conductive resin layer 60, and the plating thickness can be adjusted by adjusting the conditions of the plating method.

[0160] Through the above manufacturing steps, the multilayer ceramic capacitor 1 is manufactured.

[0161] The configuration of the multilayer ceramic capacitor 1 is not limited to the configurations shown in Figures 1A to 4. For example, the multilayer ceramic capacitor 1 may be a multilayer ceramic capacitor having a double structure, a triple structure, or a quadruple structure as shown in Figures 7A, 7B, and 7C.

[0162] The multilayer ceramic capacitor 1 shown in FIG. 7A is a double-structure multilayer ceramic capacitor 1, and includes, as the internal electrode layers 30, a first internal electrode layer 33 and a second internal electrode layer 34, as well as a floating internal electrode layer 35 that serves as a floating internal conductor layer that is not drawn out to either the first end face LS1 or the second end face LS2.

[0163] The multilayer ceramic capacitor 1 shown in FIG. 7B is a triple-structure multilayer ceramic capacitor 1 including a first floating internal electrode layer 35A and a second floating internal electrode layer 35B as the floating internal electrode layers 35.

[0164] The multilayer ceramic capacitor 1 shown in FIG. 7C is a four-layer structure multilayer ceramic capacitor 1 having, as the floating internal electrode layers 35, a first floating internal electrode layer 35A, a second floating internal electrode layer 35B, and a third floating internal electrode layer 35C.

[0165] In this way, by providing the floating internal electrode layers 35 as the internal electrode layers 30, the multilayer ceramic capacitor 1 has a structure in which the opposing electrode portion is divided into multiple parts. As a result, multiple capacitor components are formed between the opposing internal electrode layers 30, and these capacitor components are connected in series. Therefore, the voltage applied to each capacitor component is reduced, and the multilayer ceramic capacitor 1 can have a high withstand voltage. It goes without saying that the multilayer ceramic capacitor 1 of the embodiment may have a multi-connection structure of four or more.

[0166] In the multilayer ceramic capacitor 1 having the structure shown in Figures 7A, 7B, and 7C, as in the above-mentioned embodiment, the first external electrode 40A and the second external electrode 40B each have a main surface side external electrode, and these main surface side external electrodes have a main surface side step portion 800.

[0167] Although not shown, in the multilayer ceramic capacitor 1 having the structure shown in Figures 7A, 7B, and 7C, similarly to the above-described embodiment, the first external electrode 40A and the second external electrode 40B each have a side surface side external electrode, and these side surface side external electrodes have a side surface side step portion 900.

[0168] In particular, multilayer ceramic capacitors 1 having a two-, three-, or four-layer structure with floating internal electrode layers 35, as shown in FIGS. 7A to 7C, are effective for use under high voltages. However, under high voltages, it is preferable to apply a shrinkage stress to the laminate 10 as a countermeasure against electrostriction. To achieve this, the plating thickness of the external electrodes on the main and side surfaces of the laminate 10 is increased. Even in such a structure, the plating layer on the inner thin portion of the main surface-side external electrode can be made thicker than the plating layer on the outer thick portion to increase the compressive stress caused by the plating, thereby further improving the flexure resistance. Furthermore, even in such a multilayer ceramic capacitor 1 having a multiple structure, by providing a step portion in the main surface-side external electrode as in the embodiment, for example, the flexure resistance can be improved as described above, and the occurrence of cracks and the like in the laminate 10 can be suppressed.

[0169] The multilayer ceramic capacitor 1 according to the embodiment described above provides the following advantages.

[0170] (1) A multilayer ceramic capacitor 1 according to an embodiment includes a laminate 10 including dielectric layers 20 as a plurality of ceramic layers alternately stacked in a stacking direction T as a height direction and internal electrode layers 30 as a plurality of internal conductor layers, and including a pair of main surfaces TS facing the stacking direction T, a pair of end faces LS facing a length direction L perpendicular to the stacking direction T, and a pair of side surfaces WS facing a width direction W perpendicular to the stacking direction T and the length direction L, and a pair of external electrodes 40 arranged spaced apart from each other at both ends of the length direction L of the laminate 10, wherein the main surfaces TS include a first main surface TS1 and a second main surface TS2 facing the stacking direction T, the end faces LS include a first end face LS1 and a second end face LS2 facing the length direction L, and the side surfaces WS are a first side surface facing the width direction W. the first end face LS1 and the second end face LS2, the internal electrode layer 30 includes a first internal electrode layer 31 as a first internal conductor layer drawn out to the first end face LS1, and a second internal electrode layer 32 as a second internal conductor layer drawn out to the second end face LS2, the external electrode 40 includes a main surface-side external electrode arranged on at least one of the first main surface TS1 and the second main surface TS2, the main surface-side external electrode having a surface facing the main surface TS, the surface having a main surface-side step portion 800 as a step portion that makes the height of the surface on the central side in the longitudinal direction L of the laminate 10 lower than the outer surface in the longitudinal direction L of the laminate 10, in terms of the height from the main surface TS to the surface, and the main surface-side step portion 800 has a curved shape that is convex toward the center in the longitudinal direction L, and extends across the width on the surface.

[0171] This improves the resistance to bending when the multilayer ceramic capacitor 1 is mounted on a substrate, and the occurrence of cracks in the laminate 10 is suppressed.

[0172] (2) In the multilayer ceramic capacitor 1 according to the embodiment, the external electrode 40 has a curved shape at the end portion on the central side of the longitudinal direction L of the laminate 10 that is convex toward the center in the longitudinal direction L, and has an edge 411eA that extends across the width, and the edge 411eA has a curvature that is smaller than the curvature of the main surface side step portion 800.

[0173] This improves the resistance to bending when the multilayer ceramic capacitor 1 is mounted on a substrate, and the occurrence of cracks in the laminate 10 is suppressed.

[0174] (3) In the multilayer ceramic capacitor 1 according to the embodiment, the main surface side external electrode 411A has a base electrode layer 50 arranged on the main surface TS, a plating layer 70 arranged above the base electrode layer 50, and a conductive resin layer 60 arranged between the base electrode layer 50 and the plating layer 70, and the plating layer 70 is arranged on the base electrode layer 50 closer to the center of the length direction L of the laminate 10 than the main surface side step portion 800, and the conductive resin layer 60 is not arranged.

[0175] This allows the amount of conductive resin layer 60 to be reduced, and accordingly, the increase in the dimensions of the external electrodes 40 can be suppressed.

[0176] (4) In the multilayer ceramic capacitor 1 according to the embodiment, the thickness H4 of the plating layer 70 located closer to the center of the laminate 10 in the longitudinal direction L than the main surface side step portion 800 is greater than the thickness H3 of the plating layer 70 located closer to the outside of the main surface side step portion 800 in the longitudinal direction L of the laminate 10.

[0177] This increases the compressive stress of the plating, improving resistance to bending. Also, the thick plating creates areas that improve board mountability.

[0178] In the multilayer ceramic capacitor 1 of the embodiment, each of the first external electrode 40A and the second external electrode 40B includes a side surface side external electrode, and the side surface side external electrode may also include a configuration having a step portion similar to that of the main surface side external electrode.

[0179] That is, the multilayer ceramic capacitor 1 of the embodiment includes a laminate 10 including dielectric layers 20 as a plurality of ceramic layers and internal electrode layers 30 as a plurality of internal conductor layers alternately stacked in a stacking direction T as a height direction, and including a pair of main surfaces TS facing the stacking direction T, a pair of end faces LS facing a length direction L perpendicular to the stacking direction T, and a pair of side surfaces WS facing a width direction W perpendicular to the stacking direction T and the length direction L, and a pair of external electrodes 40 arranged spaced apart from each other at both ends of the length direction L of the laminate 10, the main surface TS includes a first main surface TS1 and a second main surface TS2 that face each other in the stacking direction T, The end surface LS includes a first end surface LS1 and a second end surface LS2 that face each other in the longitudinal direction L, The side surface WS includes a first side surface WS1 and a second side surface WS2 that face each other in the width direction W, The internal electrode layer 30 includes a first internal electrode layer 31 as a first internal conductor layer that is drawn to the first end face LS1, and a second internal electrode layer 32 as a second internal conductor layer that is drawn to the second end face LS2, and the external electrode 40 includes a side-side external electrode arranged on at least one of the first side face WS1 and the second side face WS2, and the side-side external electrode has a surface facing the side face WS, and the surface has a side-side step portion as a step portion that makes the height of the surface on the central side of the longitudinal direction L of the laminate 10 lower than the surface on the outer side of the longitudinal direction L of the laminate 10, in terms of the height from the side face WS to the surface, and the side-side step portion has a curved shape that is convex toward the center of the longitudinal direction L and extends across the width direction on the surface.

[0180] The present invention is not limited to the configurations of the above-described embodiments, and can be appropriately modified and applied within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations described in the above-described embodiments.

[0181] For example, the multilayer ceramic capacitor 1 may be a two-terminal type having two external electrodes, or may be a multi-terminal type having many external electrodes.

[0182] In the above-described embodiment, a multilayer ceramic capacitor using a dielectric ceramic is exemplified as a multilayer ceramic electronic component, but the multilayer ceramic electronic component of the present disclosure is not limited to this and can be applied to various other multilayer ceramic electronic components such as piezoelectric components using piezoelectric ceramic, thermistors using semiconductor ceramic, inductors using magnetic ceramic, etc. Examples of piezoelectric ceramics include PZT (lead zirconate titanate) ceramics, examples of semiconductor ceramics include spinel ceramics, and examples of magnetic ceramics include ferrite.

[0183] Although the external electrode 40 in the embodiment has the conductive resin layer 60 , the external electrode 40 does not necessarily have to have the conductive resin layer 60 . [Explanation of symbols]

[0184] 1. Multilayer ceramic capacitors (multilayer ceramic electronic components) 10 Laminate 20 Dielectric layer (ceramic layer) 30 Internal electrode layer (internal conductor layer) 31 First internal electrode layer (first internal conductor layer) 32 Second internal electrode layer (second internal conductor layer) 40 External electrode 411A, 411B First main surface side external electrodes (main surface side external electrodes) 412A, 412B Second main surface side external electrodes (main surface side external electrodes) 411eA, 411eB First main surface side edge (edge) 412eA, 412eB Second main surface side edge (edge) 411sA, 412sA, 411sB, 412sB surface 50 Base electrode layer 60 Conductive resin layer 70 plating layer 800 Main surface step (step) 810A, 810B First main surface side step portion (step portion) 820A, 820B Step portion on the second main surface side (step portion) L lengthwise T Stacking direction (height direction) W width direction LS end face LS1 First end face LS2 Second end face TS main surface TS1 First principal surface TS2 Second principal surface WS side WS1 First Aspect WS2 Second Aspect

Claims

1. a laminate including a plurality of ceramic layers and a plurality of internal conductor layers alternately stacked in a height direction, and including a pair of main surfaces opposing each other in the height direction, a pair of end faces opposing each other in a length direction perpendicular to the height direction, and a pair of side surfaces opposing each other in a width direction perpendicular to the height direction and the length direction; a pair of external electrodes disposed at opposite ends of the laminate in the longitudinal direction and spaced apart from each other; the main surfaces include a first main surface and a second main surface facing each other in the height direction, the end surfaces include a first end surface and a second end surface opposed to each other in the longitudinal direction; the side surfaces include a first side surface and a second side surface opposed to each other in the width direction, the internal conductor layer includes a first internal conductor layer extended to the first end surface and a second internal conductor layer extended to the second end surface; the external electrodes include main surface-side external electrodes disposed on at least one of the first main surface and the second main surface, the main surface side external electrode has a surface facing the main surface, the surface has a step portion that makes the height of the surface on a central side in the longitudinal direction of the laminate lower than the height of the surface on an outer side in the longitudinal direction of the laminate, in terms of a height from the main surface to the surface; The step portion has a curved shape that is convex toward the center in the length direction and extends across the width direction on the surface.

2. the external electrode has a curved shape at an end portion on a center side in the longitudinal direction that is convex toward the center in the longitudinal direction, and has an edge that extends across the width direction; 2. The multilayer ceramic electronic component according to claim 1, wherein the edge has a curvature smaller than that of the step portion.

3. the main surface-side external electrode has a base electrode layer disposed on the main surface, a plating layer disposed above the base electrode layer, and a conductive resin layer disposed between the base electrode layer and the plating layer, 3. The multilayer ceramic electronic component according to claim 1, wherein the plating layer is disposed on the base electrode layer, and the conductive resin layer is not disposed on the laminate at a position closer to the center of the laminate in the longitudinal direction than the step portion.

4. 4. The multilayer ceramic electronic component according to claim 3, wherein a thickness of the plating layer on a portion of the laminate closer to the center in the longitudinal direction than the step portion is greater than a thickness of the plating layer on a portion outside the step portion in the longitudinal direction of the laminate.

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