Laminated ceramic electronic component

Abstract

Provided is a laminated ceramic electronic component capable of improving flexure resistance. The present invention is provided with a laminate (10) including an internal electrode layer (30), and a pair of external electrodes (40) disposed at both ends of the laminate (10), the external electrodes (40) including main surface-side external electrodes (411A) having surfaces (411sA) facing a main surface (TS), and the main surface-side external electrodes (411A) having surfaces (411sA) facing the main surface (TS). The surface (411sA) has a step section (900) in which the height of the surface (411sA) on the center side in the longitudinal direction (L) of the laminate (10) is lower than the height of the surface (411sA) on the outer side in the longitudinal direction (L) of the laminate (10) at the height from the main surface (TS) to the surface (411sA), and the step section (900) has a curved shape protruding toward the center in the longitudinal direction (L) and extends across the width direction (W) on the surface (411sA).

Description

Technical Field

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

[0002] Conventionally, multilayer ceramic capacitors are known as multilayer ceramic electronic components. Generally, a multilayer ceramic capacitor comprises a laminated body composed of a plurality of dielectric layers and internal electrode layers alternately stacked, and external electrodes disposed on both end surfaces of the laminated body. For example, Patent Document 1 discloses a multilayer ceramic capacitor having the aforementioned structure, wherein the external electrodes include a base electrode layer formed by sintering.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-243249

[0006] However, in such multilayer ceramic capacitors, there is a concern that flexural stress generated in the external electrodes is transmitted to the multilayer body during mounting on a substrate, causing cracks in the multilayer body. Therefore, there is a need for multilayer ceramic capacitors with improved flexural resistance. Summary of the Invention

[0007] Problems to be solved by the invention

[0008] An object of the present invention is to provide a multilayer ceramic electronic component capable of improving flexural resistance.

[0009] Technical solutions to solve problems

[0010] The multilayer ceramic capacitor according to the present invention comprises: a multilayer body comprising a plurality of ceramic layers and a plurality of internal conductor layers alternately stacked in a height direction, and comprising a pair of main surfaces opposing each other in the height direction, a pair of end surfaces 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 respectively arranged at both end portions of the multilayer body in the length direction, the main surfaces comprising a first main surface and a second main surface opposing each other in the height direction, the end surfaces comprising a first end surface and a second end surface opposing each other in the length direction, and the side surfaces comprising a first end surface and a second end surface opposing each other in the width direction. side surface and a second side surface, the internal conductor layer includes a first internal conductor layer led to the first end surface, and a second internal conductor layer led to the second end surface, the external electrode includes a main surface side external electrode arranged on at least one of the first main surface and the second main surface, the main surface side external electrode has a surface opposite to the main surface, and the surface has a step portion at a height from the main surface to the surface so that the height of the surface on the central side of the longitudinal direction of the stack is lower than the surface on the outer side of the longitudinal direction of the stack, the step portion has a curved shape convex toward the center of the longitudinal direction, and extends across the width direction on the surface.

[0011] Effects of the Invention

[0012] According to the present invention, a multilayer ceramic electronic component capable of improving flexural resistance can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A It is a perspective view of the appearance of a multilayer ceramic capacitor according to an embodiment.

[0014] Figure 1B yes Figure 1A IB to view.

[0015] Figure 1C yes Figure 1A IC-oriented view.

[0016] Figure 2 It is along Figure 1A as well as Figure 1B Cross-sectional view along line II-II.

[0017] Figure 3 It is along Figure 1C as well as Figure 2 Cross-sectional view along line III-III.

[0018] Figure 4 It is along Figure 1C as well as Figure 2A cross-sectional view taken along line IV-IV.

[0019] Figure 5 yes Figure 2 The enlarged view of the portion indicated by V in FIG. 1 is a view showing a cross section of the first main surface side external electrode.

[0020] Figure 6A 1 is a diagram illustrating a method for manufacturing a multilayer ceramic capacitor according to an embodiment, and is a diagram illustrating a first step of forming external electrodes on a multilayer body.

[0021] Figure 6B 1 is a diagram illustrating a method for manufacturing a multilayer ceramic capacitor according to an embodiment, and is a diagram illustrating a second step of forming external electrodes on a multilayer body.

[0022] Figure 7A FIG. 1 is a diagram showing a multilayer ceramic capacitor having a dual structure.

[0023] Figure 7B A diagram showing a triple-structured multilayer ceramic capacitor.

[0024] Figure 7C A diagram showing a quadruple-structured multilayer ceramic capacitor.

[0025] Description of Reference Numerals

[0026] 1. Multilayer ceramic capacitors (multilayer ceramic electronic components);

[0027] 10 laminates;

[0028] 20 dielectric layer (ceramic layer);

[0029] 30 internal electrode layer (internal conductor layer);

[0030] 31 first internal electrode layer (first internal conductor layer);

[0031] 32 second internal electrode layer (second internal conductor layer);

[0032] 40 external electrodes;

[0033] 411A, 411B: first main surface side external electrodes (main surface side external electrodes);

[0034] 412A, 412B: second main surface side external electrodes (main surface side external electrodes);

[0035] 411eA, 411eB: first main surface side edge (edge);

[0036] 412eA, 412eB: end edge (end edge) on the second main surface side;

[0037] 411sA, 412sA, 411sB, 412sB surfaces;

[0038] 50 base electrode layer;

[0039] 60 conductive resin layer;

[0040] 70 coating;

[0041] 800 main surface side step portion (step portion);

[0042] 810A, 810B first main surface side step portion (step portion);

[0043] 820A, 820B second main surface side step portion (step portion);

[0044] L length direction;

[0045] T stacking direction (height direction);

[0046] W width direction;

[0047] LS end face;

[0048] LS1 1st end face;

[0049] LS2 second end face;

[0050] TS main surface;

[0051] TS1 1st main surface;

[0052] TS2 2nd main surface;

[0053] WS side;

[0054] WS1 lateral 1;

[0055] WS2 Side 2. DETAILED DESCRIPTION

[0056] Below, using Figures 1A to 4 A multilayer ceramic capacitor 1 as a multilayer ceramic electronic component according to an embodiment will be described. Figure 1A It is an external perspective view of a multilayer ceramic capacitor 1 according to the embodiment. Figure 1B yes Figure 1A IB to view. Figure 1C yes Figure 1A IC-oriented view. Figure 2 It is along Figure 1A as well as Figure 1B Cross-sectional view along line II-II. Figure 3 It is along Figure 1C as well as Figure 2 Cross-sectional view along line III-III. Figure 4 It is along Figure 1C as well as Figure 2 A cross-sectional view taken along line IV-IV.

[0057] The multilayer ceramic capacitor 1 includes a laminate 10 and external electrodes 40 .

[0058] exist Figures 1A to 4 The XYZ orthogonal coordinate system is shown. The length direction L of the multilayer ceramic capacitor 1 and the multilayer body 10 corresponds to the X direction. The width direction W of the multilayer ceramic capacitor 1 and the multilayer body 10 corresponds to the Y direction. The stacking direction T, which is the height direction of the multilayer ceramic capacitor 1 and the multilayer body 10, corresponds to the Z direction. Figure 2 The cross section shown is also referred to as the LT cross section. Figure 3 The cross section shown is also referred to as the WT cross section. Figure 4 The cross section shown is also referred to as the LW cross section.

[0059] like Figure 1A As shown, the stacked body 10 includes a pair of main surfaces TS opposing each other in the stacking direction T, a pair of end surfaces LS opposing each other in the longitudinal direction L orthogonal to the stacking direction T, and a pair of side surfaces WS opposing each other in the width direction W orthogonal to the stacking direction T and the longitudinal direction L. The main surfaces TS include a first main surface TS1 and a second main surface TS2 opposing each other in the stacking direction T. The end surfaces LS include a first end surface LS1 and a second end surface LS2 opposing each other in the longitudinal direction L. The side surfaces WS include a first side surface WS1 and a second side surface WS2 opposing each other in the width direction W.

[0060] like Figures 1A to 1C As shown, the laminate 10 has a generally rectangular parallelepiped shape. Furthermore, the length L of the laminate 10 is not necessarily longer than its width W. The corners and ridges of the laminate 10 are preferably rounded. A corner is where three surfaces of the laminate intersect, and a ridge is where two surfaces of the laminate intersect. Furthermore, a portion or all of the surface constituting the laminate 10 may have irregularities.

[0061] The dimensions of the laminate 10 are not particularly limited, but if the dimension in the longitudinal direction L of the laminate 10 is defined as the L dimension, the L dimension is preferably 0.2 mm or more and 10 mm or less. Furthermore, if the dimension in the stacking direction T of the laminate 10 is defined as the T dimension, the T dimension is preferably 0.1 mm or more and 10 mm or less. Furthermore, if the dimension in the width direction W of the laminate 10 is defined as the W dimension, the W dimension is preferably 0.1 mm or more and 10 mm or less.

[0062] like Figure 2 as well as Figure 3As shown, the laminate 10 includes 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 in the lamination direction T so as to sandwich the inner layer portion 11 .

[0063] The inner portion 11 includes a plurality of dielectric layers 20, which are ceramic layers, and a plurality of internal electrode layers 30, which are internal conductor layers. The inner portion 11 includes the internal electrode layer 30 located closest to the first main surface TS1 in the stacking direction T, through the internal electrode layer 30 located closest to the second main surface TS2. In the inner portion 11, the plurality of internal electrode layers 30 are arranged opposite each other with the dielectric layer 20 interposed therebetween. The inner portion 11 generates capacitance and essentially functions as a capacitor.

[0064] The plurality of dielectric layers 20 are formed of a dielectric material. For example, the dielectric material may be a dielectric ceramic containing BaTiO3, CaTiO3, SrTiO3, or CaZrO3. Alternatively, the dielectric material may be a material containing these main components with the addition of secondary components such as Mn compounds, Fe compounds, Cr compounds, Co compounds, or Ni compounds.

[0065] The thickness of dielectric layer 20 is preferably not less than 0.5 μm and not more than 30 μm. The number of dielectric layers 20 stacked is preferably not less than 10 and not more than 1500. The number of dielectric layers 20 is the sum of the number of dielectric layers in inner layer portion 11 and the number of dielectric layers in first principal surface-side outer layer portion 12A and second principal surface-side outer layer portion 12B.

[0066] The plurality of internal electrode layers 30 include a plurality of first internal electrode layers 31 serving as first internal conductor layers and a plurality of second internal electrode layers 32 serving as second internal conductor layers. The plurality of first internal electrode layers 31 are disposed on the plurality of dielectric layers 20. The plurality of second internal electrode layers 32 are disposed on the plurality of dielectric layers 20. The plurality of first internal electrode layers 31 and the plurality of second internal electrode layers 32 are alternately disposed in the stacking direction T of the laminate 10, with the dielectric layers 20 interposed therebetween. The first internal electrode layers 31 and the second internal electrode layers 32 are disposed with the dielectric layers 20 interposed therebetween. In the following description, when the first internal electrode layers 31 and the second internal electrode layers 32 do not need to be distinguished from each other, the first internal electrode layers 31 and the second internal electrode layers 32 may be collectively referred to as the internal electrode layers 30.

[0067] The first internal electrode layer 31 includes a first opposing portion 31A opposing the second internal electrode layer 32 and a first lead portion 31B led out from the first opposing portion 31A toward the first end surface LS1. The first lead portion 31B is exposed on the first end surface LS1.

[0068] The second internal electrode layer 32 includes a second opposing portion 32A opposing the first internal electrode layer 31 and a second lead portion 32B led out from the second opposing portion 32A toward the second end surface LS2. The second lead portion 32B is exposed at the second end surface LS2.

[0069] 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 capacitance and exhibiting capacitor characteristics.

[0070] 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 angled. The shapes of the first lead portion 31B and the second lead portion 32B are not particularly limited, but are preferably rectangular. However, the corners of the rectangular shape may be rounded or angled.

[0071] The first opposing portion 31A and the first lead portion 31B may have the same width W dimension, or one of them may be smaller. The second opposing portion 32A and the second lead portion 32B may have the same width W dimension, or one of them may be smaller.

[0072] The first internal electrode layer 31 and the second internal electrode layer 32 are formed of a suitable 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 formed of, for example, an Ag-Pd alloy.

[0073] The thickness of each of the first internal electrode layer 31 and the second internal electrode layer 32 is preferably about 0.2 μm to 2.0 μm, for example. The total number of the first internal electrode layers 31 and the second internal electrode layers 32 is preferably 10 to 1500.

[0074] The first principal surface-side outer layer portion 12A is located on the first principal surface TS1 side of the laminate 10. The first principal surface-side outer layer portion 12A is an aggregate of a plurality of dielectric layers 20 located between the first principal surface TS1 and the internal electrode layer 30 closest to the first principal surface TS1. The dielectric layers 20 used in the first principal 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 made of a different material.

[0075] 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 aggregate of a plurality of 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 made of a different material.

[0076] Furthermore, the laminate 10 includes an opposing electrode portion 11E. The opposing electrode portion 11E is a portion where 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. The opposing electrode portion 11E is configured as a portion of the inner layer portion 11. Figure 4 : denoted by : W and L. The range of the opposing electrode portion 11E in the width direction W and the length direction L. The opposing electrode portion 11E is also referred to as a capacitor effective portion.

[0077] In addition, the stacked body 10 has a side outer layer portion WG. The side outer layer portion WG has a first side outer layer portion WG1 and a second side outer layer portion WG2. The first side outer layer portion WG1 is a portion including the dielectric layer 20 located between the opposing electrode portion 11E and the first side WS1. The second side outer layer portion WG2 is a portion including the dielectric layer 20 located between the opposing electrode portion 11E and the second side WS2. Figure 3 as well as Figure 4 : Graph 1 shows the range of the first side outer layer portion WG1 and the second side outer layer portion WG2 in the width direction W. The side outer layer portion is also referred to as a W gap or a side gap.

[0078] In addition, the stacked body 10 has an end face side outer layer portion LG. The end face side outer layer portion LG has a first end face side outer layer portion LG1 and a second end face side outer layer portion LG2. The first end face side outer layer portion LG1 is a portion including the dielectric layer 20 located between the opposing electrode portion 11E and the first end face LS1. The second end face side outer layer portion LG2 is a portion including the dielectric layer 20 located between the opposing electrode portion 11E and the second end face LS2. Figure 2 as well as Figure 4 : : shows the range of the first end surface side outer layer portion LG1 and the second end surface side outer layer portion LG2 in the longitudinal direction L. In addition, the end surface side outer layer portion is also called an L gap or an end gap.

[0079] The external electrode 40 includes a first external electrode 40A arranged on the first end surface LS1 side and a second external electrode 40B arranged on the second end surface LS2 side.

[0080] The first external electrode 40A is disposed on the first end surface 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 the embodiment, the first external electrode 40A is formed to extend from the first end surface LS1 to a portion of the first main surface TS1 and a portion of the second main surface TS2, and to a portion of the first side surface WS1 and a portion of the second side surface WS2.

[0081] The second external electrode 40B is disposed on the second end surface 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 surface LS2 to a portion of the first main surface TS1 and 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.

[0082] As described above, within 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 oppose each other via the dielectric layer 20, thereby forming a capacitor. Consequently, capacitor characteristics 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.

[0083] The first external electrode 40A includes 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 includes a first Ni plating layer 71A and a first Sn plating layer 72A.

[0084] The second external electrode 40B includes a second foundation electrode layer 50B containing a metal component, a second conductive resin layer 60B disposed on the second foundation electrode layer 50B, and a second plating layer 70B disposed on the second conductive resin layer 60B. The second plating layer 70B includes a second Ni plating layer 71B and a second Sn plating layer 72B.

[0085] Here, the basic structure of the layers constituting the first external electrode 40A and the second external electrode 40B is the same. Furthermore, the first external electrode 40A and the second external electrode 40B are substantially plane-symmetrical with respect to the LW cross-section taken at the center of the longitudinal direction L of the multilayer ceramic capacitor 1. Therefore, unless otherwise specified, the first external electrode 40A and the second external electrode 40B are sometimes collectively referred to as the external electrode 40. Furthermore, unless otherwise specified, the first foundation electrode layer 50A and the second foundation electrode layer 50B are sometimes collectively referred to as the foundation electrode layer 50. Furthermore, unless otherwise specified, the first conductive resin layer 60A and the second conductive resin layer 60B are sometimes collectively referred to as the conductive resin layer 60. In addition, when there is no need to specifically distinguish between the first plating layer 70A and the second plating layer 70B, the first plating layer 70A and the second plating layer 70B are sometimes collectively referred to as the plating layer 70. In addition, when there is no need to specifically 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 are sometimes collectively referred to as the Ni plating layer 71. In addition, when there is no need to specifically 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 are sometimes collectively referred to as the Sn plating layer 72.

[0086] The foundation electrode layer 50 includes a first foundation electrode layer 50A and a second foundation electrode layer 50B.

[0087] The first foundation electrode layer 50A is disposed on the first end surface LS1. The first foundation electrode layer 50A is connected to the first internal electrode layer 31. In the embodiment, the first foundation electrode layer 50A is formed to extend from the first end surface LS1 to a portion of the first main surface TS1, a portion of the second main surface TS2, a portion of the first side surface WS1, and a portion of the second side surface WS2.

[0088] The second foundation electrode layer 50B is disposed on the second end surface LS2. The second foundation electrode layer 50B is connected to the second internal electrode layer 32. In the embodiment, the second foundation electrode layer 50B is formed to extend from the second end surface LS2 to a portion of the first main surface TS1, a portion of the second main surface TS2, a portion of the first side surface WS1, and a portion of the second side surface WS2.

[0089] The first and second base electrode layers 50A and 50B of the embodiment are sintered layers. The sintered layers preferably contain either a metal component and a glass component or a ceramic component, or both. This improves the adhesion between the laminate 10 and the base electrode layer. The metal component may include, for example, at least one selected from Cu, Ni, Ag, Pd, an Ag-Pd alloy, Au, and the like. The glass component may include, for example, at least one selected from B, Si, Ba, Mg, Al, Li, and the like. The presence of a glass component can assist in sintering the metal component in the base electrode layer, thereby promoting sintering. The ceramic component may be the same or a different type of ceramic material as the dielectric layer 20. The ceramic component may include, for example, at least one selected from BaTiO3, CaTiO3, (Ba,Ca)TiO3, SrTiO3, CaZrO3, and the like.

[0090] The sintered layer is formed by, for example, applying a conductive paste containing glass and metal to a laminate and sintering it. The sintered layer can be formed by simultaneously sintering a laminated chip having internal electrodes and a dielectric layer and a conductive paste applied to the laminated chip, or by sintering the laminated chip having internal electrodes and a dielectric layer to obtain a laminate, then applying a conductive paste to the laminate and sintering it. Furthermore, when the laminated chip having internal electrodes and a dielectric layer and the conductive paste applied to the laminated chip are sintered simultaneously, the sintered layer is preferably formed by sintering a conductive paste to which a ceramic material has been added instead of the glass component. In this case, it is particularly preferred to use the same type of ceramic material as the dielectric layer 20 as the added ceramic material. The sintered layer can also be a plurality of layers.

[0091] The thickness of the first foundation electrode layer 50A located at the first end surface LS1 in the longitudinal direction L is preferably approximately 2 μm or more and 220 μm or less at the center portion in the stacking direction T and the width direction W of the first foundation electrode layer 50A.

[0092] The thickness of the second foundation electrode layer 50B located at the second end surface LS2 in the longitudinal direction L is preferably approximately 2 μm or more and 220 μm or less at the center portion in the stacking direction T and the width direction W of the second foundation electrode layer 50B.

[0093] When the first base electrode layer 50A is also provided on a portion of at least one surface of the first main surface TS1 or the second main surface TS2, the thickness of the first base electrode layer 50A provided on the portion in the stacking direction T is preferably, for example, greater than 3 μm and less than 40 μm in the central portion of the first base electrode layer 50A provided on the portion in the length direction L and the width direction W.

[0094] When the first base electrode layer 50A is also provided on a portion of at least one surface of the first side surface WS1 or the second side surface WS2, the thickness in the width direction of the first base electrode layer 50A provided on the portion is preferably, for example, greater than 3 μm and less than 40 μm in the central portion of the length direction L and the stacking direction T of the first base electrode layer 50A provided on the portion.

[0095] When the second base electrode layer 50B is also provided on a portion of at least one surface of the first main surface TS1 or the second main surface TS2, the thickness of the second base electrode layer 50B provided on the portion in the stacking direction T is preferably, for example, greater than 3 μm and less than 40 μm in the central portion of the second base electrode layer 50B provided on the portion in the length direction L and the width direction W.

[0096] When the second base electrode layer 50B is also provided on a portion of at least one surface of the first side surface WS1 or the second side surface WS2, the thickness in the width direction of the second base electrode layer 50B provided on the portion is preferably, for example, greater than 3 μm and less than 40 μm in the central portion of the length direction L and the stacking direction T of the second base electrode layer 50B provided on the portion.

[0097] The external electrode 40 includes a conductive resin layer 60 including a resin component and a metal component and disposed on the base electrode layer 50 .

[0098] The conductive resin layer 60 includes a first conductive resin layer 60A and a second conductive resin layer 60B.

[0099] The first conductive resin layer 60A is configured to cover the first foundation electrode layer 50A. In the embodiment, the first conductive resin layer 60A is formed to extend from the first end surface LS1 to a portion of the first principal surface TS1, a portion of the second principal 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 configured to cover the second foundation electrode layer 50B. In the embodiment, the second conductive resin layer 60B is formed to extend from the second end surface LS2 to a portion of the first principal surface TS1, a portion of the second principal surface TS2, and a portion of the first side surface WS1 and a portion of the second side surface WS2. The length L of the first conductive resin layer 60A on the first principal surface TS1 and the second principal surface TS2 is shorter than the length L of the first foundation electrode layer 50A on the first principal surface TS1 and the second principal surface TS2. Furthermore, the length L of the second conductive resin layer 60B on the first and second principal surfaces TS1 and TS2 is shorter than the length L of the second foundation electrode layer 50B on the first and second principal surfaces TS1 and TS2 .

[0100] The thickness of the first conductive resin layer 60A in the longitudinal direction L located on the first end surface LS1 side is preferably about 5 μm or more and 200 μm or less in the center portion in the stacking direction T and the width direction W of the first conductive resin layer 60A.

[0101] The thickness of the second conductive resin layer 60B in the longitudinal direction L located on the second end surface LS2 side is preferably about 5 μm or more and 200 μm or less in the center portion in the stacking direction T and the width direction W of the second conductive resin layer 60B.

[0102] When the first conductive resin layer 60A is also provided on a portion of the first main surface TS1 side and a portion of the second main surface TS2 side, the thickness of the first conductive resin layer 60A provided in the portion in the stacking direction T is preferably, for example, greater than 5 μm and less than 200 μm in the central portion of the first conductive resin layer 60A provided in the portion in the length direction L and the width direction W.

[0103] When the first conductive resin layer 60A is also provided on a portion of the first side surface WS1 and a portion of the second side surface WS2, the thickness in the width direction of the first conductive resin layer 60A provided in the portion is preferably, for example, greater than 5 μm and less than 200 μm in the central portion of the length direction L and the stacking direction T of the first conductive resin layer 60A provided in the portion.

[0104] When the second conductive resin layer 60B is also provided on a portion of the first main surface TS1 side and a portion of the second main surface TS2 side, the thickness of the second conductive resin layer 60B provided in the portion in the stacking direction T is preferably, for example, greater than 5 μm and less than 200 μm in the central portion of the second conductive resin layer 60B provided in the portion in the length direction L and the width direction W.

[0105] When the second conductive resin layer 60B is also provided on a part of the first side surface WS1 and a part of the second side surface WS2, the thickness in the width direction of the second conductive resin layer 60B provided in the part is preferably, for example, greater than 5 μm and less than 200 μm in the central part of the length direction L and the stacking direction T of the second conductive resin layer 60B provided in the part.

[0106] The conductive resin layer 60 is provided on the base electrode layer 50. The plating layer 70 is arranged so as to cover the conductive resin layer 60 and a portion of the base electrode layer 50. The plating layer 70 includes a Ni plating layer 71 and a Sn plating layer 72.

[0107] The conductive resin layer 60 includes a resin portion as a resin component and a conductive filler as filler powder dispersed in the resin portion.

[0108] The resin portion of the conductive resin layer 60 may also include at least one selected from various well-known thermosetting resins, such as epoxy resin, phenoxy resin, phenolic resin, polyurethane resin, silicone resin, and polyimide resin. Among them, 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 includes a curing agent along with the thermosetting resin. When epoxy resin is used as the base resin, the epoxy resin curing agent may also be various well-known compounds, such as phenolic, amine, acid anhydride, imidazole, active ester, and amide-imide compounds.

[0109] Because the conductive resin layer 60 includes such a resin portion, it is more flexible than, for example, a plated film or base electrode layer 50, which is a fired product containing metal and glass components. Therefore, even when the multilayer ceramic capacitor 1 is subjected to physical shock or shock resulting from thermal cycling, the conductive resin layer 60 functions as a buffer layer. Consequently, the conductive resin layer 60 suppresses the occurrence of cracks in the multilayer ceramic capacitor 1.

[0110] The conductive fillers are dispersed and present in the resin portion in a substantially uniform distribution. The conductive fillers primarily contribute to the electrical conductivity of the conductive resin layer 60. Specifically, the plurality of conductive fillers are in contact with one another, thereby forming an electrical path within the conductive resin layer 60, thereby establishing electrical continuity between the base electrode layer 50 and the plated layer 70.

[0111] The metal constituting the conductive filler may be Ag alone, or an alloy containing Ag, or a metal powder coated with Ag on the surface of the metal powder. Ag has the lowest resistivity among metals and is therefore suitable for electrode materials. Furthermore, since Ag is a noble metal, it is not easily oxidized and has high weather resistance. Therefore, Ag metal powder is suitable as a conductive filler. Furthermore, when using a metal powder coated with Ag on the surface of the metal powder, it is preferred to use Cu, Ni, Sn, Bi, or alloy powders containing these as the metal powder.

[0112] Furthermore, the conductive filler may be a conductive filler in which Cu or Ni has been subjected to an oxidation resistance treatment. Furthermore, the conductive filler may be a metal powder coated with Sn, Ni, or Cu on the surface of the metal powder. When using a metal powder coated with Sn, Ni, or Cu on the surface of the metal powder, the metal powder is preferably Ag, Cu, Ni, Sn, Bi, or an alloy powder thereof. The conductive filler more preferably has Cu particles as a core. Furthermore, it is more preferred that at least a portion of the surface of the Cu particles be coated with a Cu-Ag alloy of Cu and Ag. At least a portion of the surface of the Cu particles may also be coated with Ag. Thus, the affinity with Ni plating improves, and the electrical properties improve.

[0113] The shape of the conductive filler is not particularly limited. Spherical or flat conductive fillers can be used. A mixture of spherical metal powder and flat metal powder is preferably used. In other words, the conductive filler powder used as the filler powder includes flat powder or spherical powder.

[0114] The average particle diameter of the conductive filler can be, for example, 0.3 μm or more and 10 μm or less.

[0115] The average particle size of the conductive filler contained in the conductive resin layer 60 is measured by calculation using a laser diffraction particle size measurement method in accordance with ISO 13320, regardless of the shape of the conductive filler.

[0116] The plating layer 70 includes a first plating layer 70A and a second plating layer 70B.

[0117] The first plating layer 70A is arranged to cover the first conductive resin layer 60A and the first base electrode layer 50A. In the embodiment, the first plating layer 70A is arranged to extend from the first end surface LS1 to a portion of the first main surface TS1 and 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.

[0118] The second plating layer 70B is arranged to cover the second conductive resin layer 60B and the second base electrode layer 50B. In the embodiment, the second plating layer 70B is arranged to extend from the second end surface LS2 to a portion of the first main surface TS1 and 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.

[0119] The plating layer 70 preferably has a two-layer structure consisting 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 corroded by the solder during assembly of the multilayer ceramic capacitor 1. The Sn plating layer 72 improves the wettability of the solder during assembly of the multilayer ceramic capacitor 1. This facilitates assembly of the multilayer ceramic capacitor 1.

[0120] The thickness of each of the first Ni plating layer 71A and the first Sn plating layer 72A is preferably 1 μm or more and 15 μm or less.

[0121] The thickness of each of the second Ni plating layer 71B and the second Sn plating layer 72B is preferably 1 μm or more and 15 μm or less.

[0122] The above is the basic structure of the multilayer ceramic capacitor 1 according to the embodiment. Furthermore, if the dimension of the multilayer ceramic capacitor 1 in the longitudinal direction L, including the multilayer body 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. Furthermore, if the dimension of the multilayer ceramic capacitor 1 in the stacking direction T is defined as the T dimension, then the T dimension is preferably 0.05 mm or more and 10 mm or less. Furthermore, if the dimension of the multilayer ceramic capacitor 1 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.

[0123] The multilayer ceramic capacitor 1 of the embodiment having the above-described basic structure has the following features in the external electrodes 40 , namely, the first external electrode 40A and the second external electrode 40B.

[0124] 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. Specifically, as described above, the first external electrode 40A of the embodiment is arranged on the first end surface LS1 and is formed by extending from the first end surface LS1 to a portion of the first main surface TS1 and 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. That is, Figure 2 as well as Figure 4 As shown, the first external electrode 40A of the embodiment includes a first end surface side external electrode 400A arranged on the first end surface LS1, a first main surface side external electrode 411A as a main surface side external electrode arranged on the first main surface TS1, a second main surface side external electrode 412A as a main surface side external electrode arranged on the second main surface TS2, Figure 4Shown are a first side surface side external electrode 421A arranged on the first side surface WS1 and a second side surface side external electrode 422A arranged on the second side surface WS2.

[0125] 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 plating layer 70A disposed on the first conductive resin layer 60A. Furthermore, in the embodiment, the first base electrode layer 50A is formed to extend from the first end surface 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. 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.

[0126] That is, Figure 2 as well as Figure 4 As shown, 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 conductive resin 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 a portion of the first base electrode layer 50A. The first end face-side conductive resin layer 600A is a portion of the first conductive resin layer 60A. The first end face-side plating layer 700A is a portion of the first plating layer 70A and includes a first Ni plating layer 71A and a first Sn plating layer 72A formed on the first Ni plating layer 71A.

[0127] like Figure 2 As shown, 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 plated 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 plated layer 711A is part of the first plated layer 70A and includes a first Ni plated layer 71A and a first Sn plated layer 72A formed on the first Ni plated layer 71A.

[0128] like Figure 2As shown, 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 plated 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 plated layer 712A is part of the first plated layer 70A and includes a first Ni plated layer 71A and a first Sn plated layer 72A formed on the first Ni plated layer 71A.

[0129] like Figure 4 As shown, the first-side external electrode 421A of the embodiment includes a first-side base electrode layer 521A disposed on the first side surface WS1, a first-side conductive resin layer 621A formed above the first-side base electrode layer 521A, and a first-side plated layer 721A formed above the first-side conductive resin layer 621A. The first-side base electrode layer 521A is part of the first base electrode layer 50A. The first-side conductive resin layer 621A is part of the first conductive resin layer 60A. The first-side plated layer 721A is part of the first plated layer 70A and includes a first Ni plated layer 71A and a first Sn plated layer 72A formed on the first Ni plated layer 71A.

[0130] like Figure 4 As shown, the second-side external electrode 422A of the embodiment includes a second-side base electrode layer 522A disposed on the second side surface WS2, a second-side conductive resin layer 622A formed above the second-side base electrode layer 522A, and a second-side plated layer 722A formed above the second-side conductive resin layer 622A. The second-side base electrode layer 522A is part of the first base electrode layer 50A. The second-side conductive resin layer 622A is part of the first conductive resin layer 60A. The second-side plated layer 722A is part of the first plated layer 70A and includes a first Ni plated layer 71A and a first Sn plated layer 72A formed on the first Ni plated layer 71A.

[0131] The thickness of each of the first principal surface side foundation electrode layer 511A, the second principal surface side foundation electrode layer 512A, the first lateral surface side foundation electrode layer 521A, and the second lateral surface side foundation electrode layer 522A is preferably, for example, 5 μm or more and 10 μm or less.

[0132] The thickness of each of the first Ni plating layer 71A and the first Sn plating layer 72A in the first main surface plating layer 711A, the second main surface plating layer 712A, the first side surface plating layer 721A, and the second side surface plating layer 722A is preferably 1 μm or more and 4 μm or less.

[0133] As described above, the second external electrode 40B of the embodiment is arranged on the second end surface LS2 and is formed by extending from the second end surface LS2 to a portion of the first main surface TS1 and 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. Figure 2 As shown, the second external electrode 40B of the embodiment includes a second end surface side external electrode 400B arranged on the second end surface LS2, a first main surface side external electrode 411B as a main surface side external electrode arranged on the first main surface TS1, a second main surface side external electrode 412B as a main surface side external electrode arranged on the second main surface TS2, Figure 4 Shown are a first side surface side external electrode 421B arranged on the first side surface WS1 and a second side surface side external electrode 422B arranged on the second side surface WS2.

[0134] 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. Furthermore, in the embodiment, the second base electrode layer 50B is formed to extend from the second end surface LS2 to a portion of the first main surface TS1, a portion of the second main surface TS2, 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.

[0135] That is, Figure 2 as well as Figure 4 As shown, 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 conductive resin layer 600B, 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 a portion of the second base electrode layer 50B. The second end face-side conductive resin layer 600B is a portion of the second conductive resin layer 60B. The second end face-side plating layer 700B is a portion of the second plating layer 70B and includes a second Ni plating layer 71B and a second Sn plating layer 72B formed on the second Ni plating layer 71B.

[0136] like Figure 2 As shown, the first main surface-side external electrode 411B of the embodiment includes a first main surface-side base electrode layer 511B arranged 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 plated 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 plated layer 711B is part of the second plated layer 70B and includes a second Ni plated layer 71B and a second Sn plated layer 72B formed on the second Ni plated layer 71B.

[0137] like Figure 2 As shown, the second main surface-side external electrode 412B of the embodiment includes a second main surface-side base electrode layer 512B arranged 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 plated 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 plated layer 712B is part of the second plated layer 70B and includes a second Ni plated layer 71B and a second Sn plated layer 72B on the second Ni plated layer 71B.

[0138] like Figure 4 As shown, the first-side external electrode 421B of the embodiment includes a first-side base electrode layer 521B disposed on the first side surface WS1, a first-side conductive resin layer 621B formed above the first-side base electrode layer 521B, and a first-side plated layer 721B formed above the first-side conductive resin layer 621B. The first-side base electrode layer 521B is part of the second base electrode layer 50B. The first-side conductive resin layer 621B is part of the second conductive resin layer 60B. The first-side plated layer 721B is part of the second plated layer 70B and includes a second Ni plated layer 71B and a second Sn plated layer 72B formed on the second Ni plated layer 71B.

[0139] like Figure 4As shown, the second-side external electrode 422B of the embodiment includes a second-side base electrode layer 522B disposed on the second side surface WS2, a second-side conductive resin layer 622B formed above the second-side base electrode layer 522B, and a second-side plated layer 722B formed above the second-side conductive resin layer 622B. The second-side base electrode layer 522B is part of the second base electrode layer 50B. The second-side conductive resin layer 622B is part of the second conductive resin layer 60B. The second-side plated layer 722B is part of the second plated layer 70B and includes a second Ni plated layer 71B and a second Sn plated layer 72B formed on the second Ni plated layer 71B.

[0140] The thickness of each of the first principal surface side foundation electrode layer 511B, the second principal surface side foundation electrode layer 512B, the first lateral surface side foundation electrode layer 521B, and the second lateral surface side foundation electrode layer 522B is preferably, for example, 5 μm or more and 10 μm or less.

[0141] The thickness of each of the second Ni plating layer 71B and the second Sn plating layer 72B in the first main surface plating layer 711B, the second main surface plating layer 712B, the first side surface plating layer 721B, and the second side surface plating layer 722B is preferably, for example, 1 μm to 4 μm.

[0142] Each of the principal-surface-side external electrodes 411A, 411B, 412A, and 412B has a principal-surface-side step portion 800 as a step portion. Each of the side-surface-side external electrodes 421A, 421B, 422A, and 422B has a side-surface-side step portion 900. These principal-surface-side step portions 800 and side-surface-side step portions 900 will be described below.

[0143] like Figure 1B as well as Figure 2As shown, the first principal-surface-side external electrode 411A of the first external electrode 40A includes a first principal-surface-side step portion 810A serving as the principal-surface-side step portion 800. The first principal-surface-side step portion 810A is formed approximately near the center of the surface 411sA of the first principal-surface-side external electrode 411A in the longitudinal direction L. The first principal-surface-side step portion 810A is a step that is lowered on the inner side of the surface 411sA of the first principal-surface-side external electrode 411A in the longitudinal direction L (the center side of the stack 10 in the longitudinal direction L) and higher on the outer side of the surface 411sA in the longitudinal direction L (the end surface LS side of the stack 10 in the longitudinal direction L). In other words, the height of the surface 411sA on the inner side of the first principal-surface-side step portion 810A in the longitudinal direction L is lower than the height of the surface 411sA on the outer side of the first principal-surface-side step portion 810A in the longitudinal direction L. The height referred to here refers to the distance from the first main surface TS1 to the surface 411sA corresponding to the stacking direction T. In this way, the surface 411sA of the first main surface side external electrode 411A is given a height difference by the first main surface side step portion 810A, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0144] like Figure 1B As shown, the first principal surface side step portion 810A has a curved shape that is convex inward in the longitudinal direction L. The first principal surface side step portion 810A extends across the width direction W on the surface 411sA of the first principal surface side external electrode 411A. The first principal surface side step portion 810A of the embodiment is formed symmetrically in the width direction W with a line F1 extending along the longitudinal direction L at the center of the width direction W of the first principal surface side external electrode 411A as a symmetry line, but does not need to be strictly symmetrical. The radius of curvature of the curved first principal surface side step portion 810A is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0145] like Figure 1B as well as Figure 2 As shown, the first main surface side external electrode 411A has a first main surface side edge 411eA at the inner end in the longitudinal direction L, which is the inner terminal end in the longitudinal direction L. Figure 1B As shown, the first principal surface side edge 411eA has a curved shape that is convex inward in the longitudinal direction. The first principal surface side edge 411eA of the embodiment is formed symmetrically in the width direction W about the aforementioned line F1, but this does not necessarily have to be strictly symmetrical. The curve of the first principal surface side edge 411eA is gentler than that of the first principal surface side step 810A and has a curvature that is closer to a straight line and smaller than that of the first principal surface side step 810A. The radius of curvature of the curved first principal surface side edge 411eA is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0146] The second main surface side external electrode 412A also has the same main surface side step portion as the first main surface side external electrode 411A. Figure 2 As shown, the second principal-surface-side external electrode 412A of the first external electrode 40A includes a second principal-surface-side step portion 820A serving as the principal-surface-side step portion 800. The second principal-surface-side step portion 820A is formed approximately near the center of the surface 412sA of the second principal-surface-side external electrode 412A in the longitudinal direction L. The second principal-surface-side step portion 820A is a step that lowers the inner side of the surface 412sA of the second principal-surface-side external electrode 412A in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 412sA on the inner side of the second principal-surface-side step portion 820A in the longitudinal direction L is lower than the height of the surface 412sA on the outer side of the second principal-surface-side step portion 820A in the longitudinal direction L. The height referred to here refers to the distance from the second principal surface TS2 to the surface 412sA corresponding to the stacking direction T. In this manner, the surface 412sA of the second principal surface side external electrode 412A is provided with a height difference by the second principal surface side step portion 820A, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0147] Although not shown in the figure, the second main surface side step portion 820A also has a curved shape that is convex toward the center in the longitudinal direction L, similar to the first main surface side step portion 810A. 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. The second main surface side step portion 820A of the embodiment is also formed symmetrically in the width direction W, but this does not necessarily have to be strictly symmetrical. The radius of curvature of the curved second main surface side step portion 820A is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0148] like Figure 2 As shown, the second main surface side external electrode 412A has a second main surface side edge 412eA at its inner end in the longitudinal direction L, which serves as the innermost end edge in the longitudinal direction L. This second main surface side edge 412eA also has a curved shape that is convex toward the inner side in the longitudinal direction, similar to the first main surface side edge 411eA described above. The second main surface side edge 412eA of the embodiment is also formed to be symmetrical in the width direction W, but it does not need to be strictly symmetrical. The curved shape of the second main surface side edge 412eA is gentler than that of the second main surface side step 820A and has a curvature that is closer to a straight line and smaller than that of the second main surface side step 820A. The radius of curvature of the curved second main surface side edge 412eA is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0149] like Figure 1B as well as Figure 2As shown, the first principal-surface-side external electrode 411B of the second external electrode 40B has a first principal-surface-side step portion 810B serving as the principal-surface-side step portion 800. The first principal-surface-side step portion 810B is formed approximately near the center of the surface 411sB of the first principal-surface-side external electrode 411B in the longitudinal direction L. The first principal-surface-side step portion 810B is a step that lowers the inner side of the surface 411sB of the first principal-surface-side external electrode 411B in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 411sB on the inner side of the first principal-surface-side step portion 810B in the longitudinal direction L is lower than the height of the surface 411sB on the outer side of the first principal-surface-side step portion 810B in the longitudinal direction L. The height referred to here refers to the distance from the first principal surface TS1 to the surface 411sB corresponding to the stacking direction T. In this manner, the surface 411sB of the first principal surface side external electrode 411B is provided with a height difference by the first principal surface side step portion 810B so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0150] like Figure 1B As shown, the first principal surface side step portion 810B has a curved shape that is convex inward in the longitudinal direction L. The first principal surface side step portion 810B extends across the width direction W on the surface 411sB of the first principal surface side external electrode 411B. The first principal surface side step portion 810B of the embodiment is formed symmetrically in the width direction W with a line F2 extending along the longitudinal direction L at the center of the width direction W of the first principal surface side external electrode 411B as a symmetry line, but does not need to be strictly symmetrical. The radius of curvature of the curved first principal surface side step portion 810B is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0151] like Figure 1B as well as Figure 2 As shown, the first principal surface side external electrode 411B has a first principal surface side edge 411eB at the inner end in the longitudinal direction L, which is the inner terminal end in the longitudinal direction L. Figure 1B As shown, the first principal surface side edge 411eB has a curved shape that is convex inward in the longitudinal direction. The first principal surface side edge 411eB of the embodiment is formed symmetrically in the width direction W with the aforementioned line F2 as the line of symmetry, but this does not necessarily have to be strictly symmetrical. The curve of the first principal surface side edge 411eB is gentler than that of the first principal surface side step 810B and has a curvature that is closer to a straight line and smaller than that of the first principal surface side step 810B. The radius of curvature of the curved first principal surface side edge 411eB is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0152] The second main surface side external electrode 412B also has the same main surface side step portion as the first main surface side external electrode 411B. Figure 2 As shown, the second main-surface-side external electrode 412B of the second external electrode 40B has a second main-surface-side step portion 820B serving as the main-surface-side step portion 800. The second main-surface-side step portion 820B is formed approximately near the center of the surface 412sB of the second main-surface-side external electrode 412B in the longitudinal direction L. The second main-surface-side step portion 820B is a step that lowers the inner side of the surface 412sB of the second main-surface-side external electrode 412B in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 412sB on the inner side of the second main-surface-side step portion 820B in the longitudinal direction L is lower than the height of the surface 412sB on the outer side of the second main-surface-side step portion 820B in the longitudinal direction L. The height referred to here refers to the distance from the second main surface TS2 to the surface 412sB corresponding to the stacking direction T. In this manner, the surface 412sB of the second principal surface side external electrode 412B is provided with a height difference by the second principal surface side step portion 820B so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0153] Although not shown in the figure, the second main surface side step portion 820B also has a curved shape that is convex toward the center in the longitudinal direction L, similar to the first main surface side step portion 810B. 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. The second main surface side step portion 820B of the embodiment is also formed symmetrically in the width direction W, but this does not need to be strictly symmetrical. The radius of curvature of the curved second main surface side step portion 820B is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0154] like Figure 2 As shown, the second main surface side external electrode 412B has a second main surface side edge 412eB at its inner end in the longitudinal direction L, which serves as the innermost end edge in the longitudinal direction L. This second main surface side edge 412eB also has a curved shape that is convex toward the inner side in the longitudinal direction, similar to the first main surface side edge 411eB described above. The second main surface side edge 412eB of the embodiment is also formed symmetrically in the width direction W, but it does not need to be strictly symmetrical. The curvature of the second main surface side edge 412eB is gentler than that of the second main surface side step 820B and has a curvature that is closer to a straight line and smaller than that of the second main surface side step 820B. The curvature radius of the curved second main surface side edge 412eB is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0155] like Figure 1C as well as Figure 4As shown, the second side surface-side external electrode 422A of the first external electrode 40A has a second side surface-side step portion 920A serving as the side surface-side step portion 900. The second side surface-side step portion 920A has the same structure as the aforementioned main surface-side step portions 810A, 820A, 810B, and 820B. The second side surface-side step portion 920A is formed approximately near the center of the surface 422sA of the second side surface-side external electrode 422A in the longitudinal direction L. The second side surface-side step portion 920A is a step that lowers the surface 422sA of the second side surface-side external electrode 422A inward in the longitudinal direction L and raises the surface 422sA in the longitudinal direction L. In other words, the height of the surface 422sA on the inner side of the second side surface-side step portion 920A in the longitudinal 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 longitudinal direction L. The height referred to here refers to the distance from the second side surface WS2 to the surface 422sA corresponding to the width direction W. In this way, the surface 422sA of the second side surface external electrode 422A is given a height difference by the second side surface step portion 920A, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0156] like Figure 1C As shown, the second-side step portion 920A has a curved shape that is convex inward in the longitudinal direction L. The second-side step portion 920A extends along the stacking direction T on the surface 422sA of the second-side external electrode 422A. The second-side step portion 920A of the embodiment is formed symmetrically in the stacking direction T with a line F3 extending along the longitudinal direction L at the center of the stacking direction T of the second-side external electrode 422A as a symmetry line, but does not need to be strictly symmetrical. The radius of curvature of the curved second-side step portion 920A is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0157] like Figure 1C as well as Figure 4 As shown, the second side surface side external electrode 422A has a second side surface side edge 422eA at the inner end portion in the longitudinal direction L, which is the inner terminal end edge in the longitudinal direction L. Figure 1C As shown, the second side edge 422eA has a curved shape that is convex inward in the longitudinal direction. The second side edge 422eA of the embodiment is formed symmetrically in the stacking direction T with the aforementioned line F3 as the line of symmetry, but this does not necessarily have to be strictly symmetrical. The curve of the second side edge 422eA is gentler than that of the second side step 920A and has a curvature that is closer to a straight line than that of the second side step 920A. The radius of curvature of the curved second side edge 422eA is not limited, but is preferably, for example, 800 μm or more and 10 mm or less.

[0158] The second side surface step portion 920A may be continuous with one or both of the first main surface step portion 810A and the second main surface step portion 820A, or may not be continuous with both.

[0159] The first side surface external electrode 421A also has the same side surface step portion as the second side surface external electrode 422A. Figure 4 As shown, the first side surface external electrode 421A of the first external electrode 40A has a first side surface step portion 910A serving as the side surface step portion 900. The first side surface step portion 910A is formed approximately near the center of the surface 421sA of the first side surface external electrode 421A in the longitudinal direction L. The first side surface step portion 910A is a step that lowers the inner side of the surface 421sA of the first side surface external electrode 421A in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 421sA on the inner side of the first side surface step portion 910A in the longitudinal direction L is lower than the height of the surface 421sA on the outer side of the first side surface step portion 910A in the longitudinal direction L. The height referred to here refers to the distance from the first side surface WS1 to the surface 421sA in the width direction W. In this manner, the surface 421sA of the first side surface external electrode 421A is provided with a height difference by the first side surface step portion 910A, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0160] Although not shown in the figure, the first side step portion 910A also has a curved shape that is convex toward the center in the longitudinal direction L, similar to the second side step portion 920A. The first side step portion 910A extends along the stacking direction T on the surface 421sA of the first side external electrode 421A. The first side step portion 910A of the embodiment is also formed symmetrically in the stacking direction T, but does not need to be strictly symmetrical. The radius of curvature of the curved first side step portion 910A is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0161] like Figure 4As shown, the first side external electrode 421A has a first side edge 421eA at the inner end in the longitudinal direction L, which serves as the end edge of the inner end in the longitudinal direction L. The first side edge 421eA also has a curved shape that is convex toward the inner side in the longitudinal direction, similar to the second side edge 422eA described above. The first side edge 421eA of the embodiment is also formed to be symmetrical in the stacking direction T, but it does not have to be strictly symmetrical. The curved shape of the first side edge 421eA is gentler than that of the first side step portion 910A and has a curvature that is closer to a straight line and smaller than that of the first side step portion 910A. The radius of curvature of the curved first side edge 421eA is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0162] The first side surface step portion 910A may be continuous with one or both of the first main surface step portion 810A and the second main surface step portion 820A, or may not be continuous with both.

[0163] like Figure 1C as well as Figure 4 As shown, the second side surface external electrode 422B of the second external electrode 40B has a second side surface step portion 920B serving as the side surface step portion 900. The second side surface step portion 920B is formed approximately near the center of the surface 422sB of the second side surface external electrode 422B in the longitudinal direction L. The second side surface step portion 920B is a step that lowers the inner side of the surface 422sB of the second side surface external electrode 422B in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 422sB on the inner side of the second side surface step portion 920B in the longitudinal direction L is lower than the height of the surface 422sB on the outer side of the second side surface step portion 920B in the longitudinal direction L. The height referred to here refers to the distance from the second side surface WS2 to the surface 422sB in the width direction W. In this manner, the surface 422sB of the second-side-side external electrode 422B is provided with a height difference by the second-side-side step portion 920B, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0164] like Figure 1CAs shown, the second-side step portion 920B has a curved shape that is convex inward in the longitudinal direction L. The second-side step portion 920B extends along the stacking direction T on the surface 422sB of the second-side external electrode 422B. The second-side step portion 920B of the embodiment is formed symmetrically in the stacking direction T with a line F4 extending along the longitudinal direction L at the center of the stacking direction T of the second-side external electrode 422B as a symmetry line, but does not need to be strictly symmetrical. The radius of curvature of the curved second-side step portion 920B is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0165] like Figure 1C as well as Figure 4 As shown, the second side surface external electrode 422B has a second side surface end edge 422eB at the inner end in the longitudinal direction L, which is the inner terminal end in the longitudinal direction L. Figure 1C As shown, the second side edge 422eB has a curved shape that is convex inward in the longitudinal direction. The second side edge 422eB of this embodiment is formed symmetrically in the stacking direction T about the line F4, but this does not necessarily have to be strictly symmetrical. The curve of the second side edge 422eB is gentler than that of the second side step 920B and has a curvature that is closer to a straight line than that of the second side step 920B. The radius of curvature of the curved second side edge 422eB is not limited, but is preferably, for example, 800 μm or more and 10 mm or less.

[0166] The second side surface step portion 920B may be continuous with one or both of the first main surface step portion 810B and the second main surface step portion 820B, or may not be continuous with both.

[0167] The first side surface external electrode 421B also has the same side surface step portion as the second side surface external electrode 422B. Figure 4As shown, the first side surface external electrode 421B of the second external electrode 40B has a first side surface step portion 910B serving as the side surface step portion 900. The first side surface step portion 910B is formed approximately near the center of the surface 421sB of the first side surface external electrode 421B in the longitudinal direction L. The first side surface step portion 910B is a step that lowers the inner side of the surface 421sB of the first side surface external electrode 421B in the longitudinal direction L and raises the outer side in the longitudinal direction L. In other words, the height of the surface 421sB on the inner side of the first side surface step portion 910B in the longitudinal direction L is lower than the height of the surface 421sB on the outer side of the first side surface step portion 910B in the longitudinal direction L. The height referred to here refers to the distance from the first side surface WS1 to the surface 421sB in the width direction W. In this manner, the surface 421sB of the first side surface external electrode 421B is provided with a height difference by the first side surface step portion 910B, so that the inner side in the longitudinal direction L becomes lower and the outer side in the longitudinal direction L becomes higher.

[0168] Although not shown in the figure, the first side step portion 910B also has a curved shape that is convex toward the center in the longitudinal direction L, similar to the second side step portion 920B. The first side step portion 910B extends across the stacking direction T on the surface 421sB of the first side external electrode. The first side step portion 910B of the embodiment is also formed symmetrically in the stacking direction, but this does not necessarily have to be strictly symmetrical. The radius of curvature of the curved first side step portion 910B is not limited, but is preferably, for example, not less than 150 μm and not more than 800 μm.

[0169] like Figure 4 As shown, the first side step portion 910B has a first side edge 421eB at its inner end in the longitudinal direction L, which serves as the end edge of the inner side thereof in the longitudinal direction L. This first side edge 421eB also has a curved shape that is convex toward the inner side in the longitudinal direction, similar to the second side edge 422eB described above. The first side edge 421eB of the embodiment is also formed to be symmetrical in the stacking direction T, but it does not need to be strictly symmetrical. The curved shape of the first side edge 421eB is gentler than that of the first side step portion 910B and has a curvature that is smaller than that of the first side step portion 910B and is close to a straight line. The radius of curvature of the curved first side edge 421eB is not limited, but is preferably, for example, not less than 800 μm and not more than 10 mm.

[0170] The first side surface step portion 910B may be continuous with one or both of the first main surface step portion 810B and the second main surface step portion 820B, or may not be continuous with both.

[0171] The aforementioned principal surface-side step portions 800 and side surface-side step portions 900 will be described in further detail. Here, the first principal surface-side external electrode 411A and the second principal surface-side external electrode 412A of the first external electrode 40A, and the first principal surface-side external electrode 411B and the second principal surface-side external electrode 412B of the second external electrode 40B have the same structure. 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 structure as the aforementioned four principal surface-side external electrodes 411A, 412A, 411B, and 412B.

[0172] The principal surface-side step portions 800 of the first external electrode 40A, namely the first principal surface-side step portion 810A and the second principal surface-side step portion 820A, and the first principal surface-side step portion 810B and the second principal surface-side step portion 820B of the second external electrode 40B have the same structure. Furthermore, the side surface-side step portions 900 of the first external electrode 40A, namely 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 structure as the four principal surface-side step portions 810A, 820A, 810B, and 820B described above.

[0173] Therefore, as representatives of the main surface side external electrodes and the main surface side step portions 800 at these four locations, and the side side external electrodes and the side side step portions 900 at these four locations, the first external electrode 40A, the first main surface side external electrode 411A, and the first main surface side step portion 810A are described below, thereby serving as a description of the main surface side external electrodes and the main surface side step portions 800 at the four locations, and the side side external electrodes and the side side step portions 900 at the four locations.

[0174] Furthermore, the first principal surface-side external electrode 411A of the first external electrode 40A corresponds to the second principal 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 principal surface-side external electrode 411B, the second principal 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 principal surface-side step portion 810A of the first external electrode 40A corresponds to the second principal 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 principal surface-side step portion 810B, the second principal 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.

[0175] 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.

[0176] Figure 5 yes Figure 2 The enlarged view of the portion indicated by V is a LT cross-sectional view showing the first main surface side external electrode 411A of the first external electrode 40A. Figure 5 Shown in Figures 1A to 4 The same XYZ orthogonal coordinate system. In addition, Figure 5 In the figures, hatching is omitted to clarify the reference numerals, reference numeral lead lines, and dimension lines.

[0177] like Figure 5 As shown, 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.

[0178] As described above, the surface 411sA of the first principal-surface-side external electrode 411A is given a height difference by the first principal-surface-side step portion 810A, being lower on the inside in the longitudinal direction L and higher on the outside in the longitudinal direction L. Specifically, the first principal-surface-side external electrode 411A includes the first principal-surface-side step portion 810A, the inner thin-walled portion 81 located inward of the first principal-surface-side step portion 810A in the longitudinal direction L (toward the center of the stack 10 in the longitudinal direction L), and the outer thick-walled portion 82 located outward of the first principal-surface-side step portion 810A in the longitudinal direction L. The surface 411sA of the first principal-surface-side external electrode 411A includes the surface 81s of the inner thin-walled portion 81, the surface 82s of the outer thick-walled portion 82, and the surface 83s of the first principal-surface-side step portion 810A.

[0179] The outer thick-walled portion 82 and the first main-surface-side stepped portion 810A include the first main-surface-side base electrode layer 511A, the first main-surface-side conductive resin layer 611A, and the first main-surface-side plated layer 711A. The inner thin-walled portion 81 includes the first main-surface-side base electrode layer 511A and the first main-surface-side plated layer 711A. Specifically, the outer thick-walled 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 plated layer 711A disposed on the first main-surface-side conductive resin layer 611A. The inner thin-walled portion 81 includes the first main-surface-side base electrode layer 511A and the first main-surface-side plated layer 711A disposed directly on the first main-surface-side base electrode layer 511A. Therefore, in the inner thin-walled portion 81 inward in the longitudinal direction L of the first principal surface side step portion 810A, the first principal surface side plated layer 711A is disposed on the first principal surface side base electrode layer 511A, and the first principal surface side conductive resin layer 611A is not disposed.

[0180] The distance from the first main surface TS1 of the laminate 10 to the surface 81s of the inner thin-walled portion 81, as measured in the stacking direction T, is the height (thickness) 81H of the inner thin-walled portion 81. The distance from the first main surface TS1 to the surface 82s of the outer thick-walled portion 82, as measured in the stacking direction T, is the height (thickness) 82H of the outer thick-walled portion 82. The maximum height 81H of the inner thin-walled portion 81 is lower than the maximum height H of the outer thick-walled portion 82.

[0181] The surface 83s of the first main surface-side step portion 810A is a continuous surface formed by the surface 82s of the outer thick-walled portion 82 and the surface 81s of the inner thin-walled portion 81. It is inclined so as to approach the first main surface TS1 as it moves from the outer side toward the inner side in the longitudinal direction L. The thickness of the step of the first main surface-side step portion 810A, that is, the step amount D formed between the outer end 84e and the inner end 85e of the first main surface-side step portion 810A in the longitudinal direction L, is not limited, but is preferably, for example, 3 μm or more and 40 μm or less. Furthermore, the step amount D is preferably 5% or more and 60% or less of the maximum thickness of the first main surface-side external electrode 411A, that is, the maximum thickness of the outer thick-walled portion 82. The step amount D is preferably greater than the thickness of the first Ni plating layer 71A.

[0182] As described above, the first principal surface-side conductive resin layer 611A is not disposed within the inner thin-walled portion 81, and its inner end 611e is located at the same position as, or outside (toward the first end surface LS1) the inner end 85e of the first principal surface-side stepped portion 810A in the longitudinal direction L. Furthermore, the inner end 511e of the first principal surface-side base electrode layer 511A is located further inward (toward the center of the laminate 10) than the inner end 85e of the first principal surface-side stepped portion 810A in the longitudinal direction L. Therefore, the length 511L in the longitudinal direction L from the first end surface 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 surface LS1 to the inner end 611e of the first principal surface-side conductive resin layer 611A.

[0183] In the embodiment, the thickness H3 of the first main surface-side plating layer 711A of the thin portion 81 is preferably larger than the thickness H4 of the first main surface-side plating layer 711A of the outer thick portion 82 .

[0184] The multilayer ceramic capacitor 1 of the embodiment is mounted on a substrate. Mounting on the substrate sometimes involves joining the external electrodes 40 to terminals, etc., of the substrate by welding. When the first main surface-side external electrode 411A is joined to the substrate by welding, the flexural stress generated by the first main surface-side external electrode 411A is transmitted to the laminate 10, potentially causing cracks, etc. 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 portion 810A that bulges inward (toward the center) in the longitudinal direction L of the laminate 10. This facilitates uniformity in the flexural stress at the interface between the first main surface-side external electrode 411A and the laminate 10 and disperses it toward the first main surface-side step portion 810A or the periphery of the first main surface-side step portion 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 electrodes.

[0185] In the multilayer ceramic capacitor 1 of the embodiment, as described above, when observing the first main surface-side external electrode 411A, the first main surface-side edge 411eA has a curvature that is gentler than that of the first main surface-side step 810A and has a curvature that is closer to a straight line than that of the first main surface-side step 810A. This facilitates uniform retention of the flexural stress generated during substrate mounting at the interface between the first main surface-side external electrode 411A and the multilayer body 10 and disperses it toward or around the first main surface-side step 810A. This improves flexural resistance and suppresses cracking in the multilayer body 10. This also applies to the other main surface-side external electrodes and side electrodes.

[0186] 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 within the inner thin-walled portion 81 located inward of the first main surface-side step 810A in the longitudinal direction L. The inner end 611e of the first main surface-side conductive resin layer 611A is located at the same position as, or outside, the inner end 85e of the first main surface-side step 810A in the longitudinal direction L. This reduces the amount of the first main surface-side conductive resin layer 611A, thereby suppressing an increase in the size of the first external electrode 40A. Furthermore, in the inner thin-walled portion 81, a region is formed where the first main surface-side plated layer 711A is directly connected to the first main surface-side base electrode layer 511A without the first main surface-side conductive resin layer 611A interposed therebetween. This reduces electrical resistance even in a structure including a conductive resin layer. This also applies to the other main surface side external electrodes and side surface side electrodes.

[0187] In the multilayer ceramic capacitor 1 of the embodiment, as described above, when observing the first main surface-side external electrode 411A, the thickness H3 of the first main surface-side plating layer 711A of the thin-walled portion 81 is preferably greater than the thickness H4 of the first main surface-side plating layer 711A of the outer thick-walled portion 82. In this case, the compressive stress caused by the plating increases, thereby improving flexural resistance. Cracks caused by flexing of the stack 10 are generated by applying stress to the side of the stack 10 that is stretched in the longitudinal direction L. When the plating layer has compressive stress as residual stress, the compressive stress caused by the plating is in the opposite direction to the stress on the stretched side. Therefore, the compressive stress caused by the plating is increased, thereby improving flexural resistance. In addition, by forming a portion with thicker plating thickness, substrate mountability is improved. This also applies to the other main surface-side external electrodes and side electrodes. On the other hand, the thickness H4 directly affects the external dimensions of the multilayer ceramic capacitor 1 and is therefore preferably thin.

[0188] 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 step portion 810A are measured, for example, by the following method. Specifically, the multilayer ceramic capacitor 1 is ground from the first side surface WS1 or the second side surface WS2 to a position approximately half the width direction W. This exposes a cross-section (LT) of the multilayer ceramic capacitor 1 at the exact center of the width direction W. The aforementioned dimensions are then measured using a digital microscope on the exposed LT cross-section.

[0189] Next, a method for manufacturing the multilayer ceramic capacitor 1 according to the embodiment will be described. The method for manufacturing the multilayer ceramic capacitor 1 according to the embodiment is not limited as long as the aforementioned requirements are met. However, a suitable manufacturing method includes the following steps. Details of each step are described below.

[0190] A dielectric sheet for dielectric layer 20 and a conductive paste for internal electrode layer 30 are prepared. The dielectric sheet and the conductive paste for internal electrode contain a binder and a solvent. The binder and solvent may be known binders and solvents.

[0191] Conductive paste for the internal electrode layer 30 is printed in a predetermined pattern on the dielectric sheet by, for example, screen printing or gravure printing. Thus, a dielectric sheet having a pattern for the first internal electrode layer 31 and a dielectric sheet having a pattern for the second internal electrode layer 32 are prepared.

[0192] By stacking a predetermined number of dielectric sheets without internal electrode layer patterns, a portion that will become the first principal surface outer layer portion 12A on the first principal surface TS1 side is formed. A dielectric sheet with a pattern printed on the first internal electrode layer 31 and a dielectric sheet with a pattern printed on the second internal electrode layer 32 are sequentially stacked on top of this portion to form the inner layer portion 11. A predetermined number of dielectric sheets without internal electrode layer patterns are stacked on top of this portion that will become the inner layer portion 11 to form the second principal surface outer layer portion 12B on the second principal surface TS2 side. In this manner, a laminated sheet is produced.

[0193] The laminated sheets are pressed in the lamination direction by isostatic pressing or the like, thereby producing a laminated block.

[0194] The stacked blocks are cut into predetermined sizes to produce stacked small pieces. Corners and ridges of the stacked small pieces may be rounded by barrel grinding or the like.

[0195] The stacked small pieces are fired to produce the laminate 10. The firing temperature depends on the materials of the dielectric layer 20 and the internal electrode layer 30, but is preferably 900°C or higher and 1400°C or lower.

[0196] A conductive paste, which will become the base electrode layer 50, is applied to both end surfaces of the laminate 10. In the embodiment, the base electrode layer 50 is a sintered layer. The conductive paste, which contains a glass component and a metal, is applied to the laminate 10 by a method such as dipping. A sintering process is then performed to form the base electrode layer 50. The sintering process temperature is preferably between 700°C and 950°C.

[0197] In the embodiment, the impregnation is performed so that the first foundation electrode layer 50A extends from the first end surface LS1 to a portion of the first main surface TS1 and the second main surface TS2. Furthermore, the impregnation is performed so that the second foundation electrode layer 50B extends from the second end surface LS2 to a portion of the first main surface TS1 and the second main surface TS2. Furthermore, in this case, the impregnation is preferably performed so that the first foundation electrode layer 50A extends to a portion of both the first side surface WS1 and the second side surface WS2. Furthermore, the impregnation is preferably performed so that the second foundation electrode layer 50B extends to a portion of both the first side surface WS1 and the second side surface WS2.

[0198] Alternatively, the pre-fired laminated pieces and the conductive paste applied to the laminated pieces can be fired simultaneously. In this case, the sintered layer is preferably formed by sintering a conductive paste to which a ceramic material has been added instead of the glass component. In this case, the added ceramic material is particularly preferably the same type as that used in dielectric layer 20. In this case, the conductive paste is applied to the pre-fired laminated pieces, and the laminated pieces and the conductive paste applied to the laminated pieces are sintered simultaneously to form a laminate 10 having a sintered layer formed thereon.

[0199] Next, the conductive resin layer 60 is formed. In addition, the conductive resin layer 60 of the embodiment is formed on the surface of the foundation electrode layer 50 .

[0200] First, a conductive resin paste is prepared, in which a conductive filler is dispersed in a thermosetting resin (the base resin) serving as the resin portion. This conductive resin paste is produced by stirring and mixing the thermosetting resin and the conductive filler. As a result, the conductive filler is uniformly distributed and dispersed within the conductive resin paste. Here, the thermosetting resin is, for example, epoxy resin. The conductive filler is, for example, Ag metal powder.

[0201] Next, a conductive resin paste is applied to the base electrode layer 50 using a dipping method and heat-treated at a temperature between 200°C and 550°C. This thermally cures the resin portion, forming the conductive resin layer 60. The heat treatment is preferably conducted in an N2 atmosphere. Furthermore, to prevent scattering of the resin and oxidation of the various metal components, the oxygen concentration is preferably kept below 100 ppm.

[0202] In the embodiment, the impregnation is performed so that the first conductive resin layer 60A extends from the first end surface LS1 to a portion of the first main surface TS1 and the second main surface TS2. Furthermore, the impregnation is performed so that the second conductive resin layer 60B extends from the second end surface LS2 to a portion of the first main surface TS1 and the second main surface TS2. Furthermore, at this time, the impregnation is preferably performed so that the first conductive resin layer 60A extends to a portion of both the first side surface WS1 and the second side surface WS2. Furthermore, the impregnation is preferably performed so that the second conductive resin layer 60B extends to a portion of both the first side surface WS1 and the second side surface WS2.

[0203] Then, a plating layer 70 is formed on the surface of the conductive resin layer 60. In the 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 sequentially using electric field plating. As the plating method, barrel plating is preferably used, for example.

[0204] Here, when obtaining the above-mentioned step portion on each main surface side external electrode and each side surface side external electrode of the external electrode 40 as in the embodiment, for example, the following method can be mentioned.

[0205] Figure 6A as well as Figure 6B The steps of forming the base electrode layer 50 and the conductive resin layer 60 in this method are schematically shown. Figure 6A As shown, a base electrode paste 50P, which becomes the base electrode layer 50, is applied to the end portion of the laminate 10 in the longitudinal direction L by dipping. Next, a conductive resin paste 60P, which becomes the conductive resin layer 60, is applied by dipping. Here, the conductive resin paste 60P is applied shallower than the base electrode paste 50P. As a result, a step portion G is formed near the end portion of the conductive resin paste 60P. This step portion G becomes the main surface side step portion 800 and the side surface side step portion 900 mentioned above. Thereafter, 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 in sequence using an electrolytic plating method. As a plating method, it is preferable to use, for example, drum plating.

[0206] Alternatively, a step portion can be formed 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 modifying the dipping method. Furthermore, by forming the surface where the base electrode layer 50 is exposed from the conductive resin layer 60 through the aforementioned dipping, the thickness of the plating can be adjusted by adjusting the plating conditions.

[0207] Through the above-described manufacturing steps, the multilayer ceramic capacitor 1 is manufactured.

[0208] The structure of the multilayer ceramic capacitor 1 is not limited to Figures 1A to 4 For example, the multilayer ceramic capacitor 1 may also be Figure 7A 、 Figure 7B as well as Figure 7C As shown, there are dual, triple, and quadruple multilayer ceramic capacitors.

[0209] Figure 7A The multilayer ceramic capacitor 1 shown is a multilayer ceramic capacitor 1 of a dual structure, and as an internal electrode layer 30, in addition to the first internal electrode layer 33 and the second internal electrode layer 34, it also has a floating internal electrode layer 35 as a floating internal conductor layer that is not led to either the first end surface LS1 or the second end surface LS2.

[0210] Figure 7B The illustrated multilayer ceramic capacitor 1 is a multilayer ceramic capacitor 1 having a triple structure including a first floating internal electrode layer 35A and a second floating internal electrode layer 35B as floating internal electrode layers 35 .

[0211] Figure 7C The illustrated multilayer ceramic capacitor 1 is a quadruple structure multilayer ceramic capacitor 1 including a first floating internal electrode layer 35A, a second floating internal electrode layer 35B, and a third floating internal electrode layer 35C as floating internal electrode layers 35 .

[0212] By providing a floating internal electrode layer 35 as the internal electrode layer 30, the multilayer ceramic capacitor 1 has a structure in which the opposing electrode portion is divided into multiple components. This results in a structure in which multiple capacitor components are formed between the opposing internal electrode layers 30 and are connected in series. Consequently, the voltage applied to each capacitor component is reduced, enabling the multilayer ceramic capacitor 1 to achieve a higher withstand voltage. Furthermore, the multilayer ceramic capacitor 1 of the embodiment can also have a multi-cell structure of four or more components.

[0213] exist Figure 7A 、 Figure 7B as well as Figure 7C In the multilayer ceramic capacitor 1 having the structure shown, similarly to the above-described embodiment, each of the first external electrode 40A and the second external electrode 40B includes a main surface-side external electrode having a main surface-side step portion 800 .

[0214] In addition, Figure 7A 、 Figure 7B as well as Figure 7C Although not shown in the figure, in the multilayer ceramic capacitor 1 having the structure shown, similarly to the above-described embodiment, the first external electrode 40A and the second external electrode 40B each include a side surface external electrode having a side surface step portion 900 .

[0215] in particular, Figures 7A to 7C While the illustrated multilayer ceramic capacitors 1 with floating internal electrode layers 35, such as the double, triple, and quadruple structures, are effective when used under high voltages, it is preferable to apply compressive stress to the multilayer body 10 as a countermeasure against electrostriction under high voltages. To achieve this, the plating thickness of the external electrodes on the main and side surfaces of the multilayer body 10 is increased. In such a structure, by making the plating layer thicker on the inner thin-walled portion of the main surface-side external electrode than on the outer thick-walled portion, the compressive stress caused by the plating is increased, thereby further improving flexural resistance. Furthermore, in such multilayer ceramic capacitors 1, by providing stepped portions on the main surface-side external electrodes, as in the embodiment, flexural resistance can be improved as described above, thereby suppressing the occurrence of cracks in the multilayer body 10.

[0216] According to the multilayer ceramic capacitor 1 according to the embodiment described above, the following effects are achieved.

[0217] (1) A multilayer ceramic capacitor 1 according to an embodiment comprises: a multilayer body 10 including a plurality of dielectric layers 20 as ceramic layers and a plurality of internal electrode layers 30 as internal conductor layers alternately stacked in a stacking direction T as a height direction, and including a pair of main surfaces TS opposing each other in the stacking direction T, a pair of end surfaces LS opposing each other in a length direction L orthogonal to the stacking direction T, and a pair of side surfaces WS opposing each other in a width direction W orthogonal to the stacking direction T and the length direction L; and a pair of external electrodes 40 disposed at both ends of the stacking body 10 in the length direction L, the main surface TS including a first main surface TS1 and a second main surface TS2 opposing each other in the stacking direction T, the end surface LS including a first end surface LS1 and a second end surface LS2 opposing each other in the length direction L, and the side surface WS including a first end surface LS1 and a second end surface LS2 opposing each other in the width direction W. The first side surface WS1 and the second side surface WS2 are opposite to each other on W, the internal electrode layer 30 includes a first internal electrode layer 31 extending to the first end surface LS1 as the first internal conductor layer, and a second internal electrode layer 32 extending to the second end surface LS2 as the second internal conductor layer, 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 has a surface opposite to the main surface TS, the surface has a main surface side step portion 800 as a step portion, which makes the height of the surface on the central side of the longitudinal direction L of the stack 10 lower than the surface on the outer side of the longitudinal direction L of the stack 10 at a height from the main surface TS to the surface, the main surface side step portion 800 has a curved shape convex toward the center of the longitudinal direction L, and extends in the width direction on the surface.

[0218] This improves the flexural resistance when the multilayer ceramic capacitor 1 is mounted on a substrate, and suppresses the occurrence of cracks in the multilayer body 10 .

[0219] (2) In the multilayer ceramic capacitor 1 according to the embodiment, the external electrode 40 has an edge 411eA at an end portion on the central side in the longitudinal direction L of the laminate 10. The edge 411eA has a curved shape that is convex toward the center in the longitudinal direction L and extends in the width direction. The edge 411eA has a curvature that is smaller than the curvature of the main surface side step portion 800.

[0220] This improves the flexural resistance when the multilayer ceramic capacitor 1 is mounted on a substrate, and suppresses the occurrence of cracks in the multilayer body 10 .

[0221] (3) In the multilayer ceramic capacitor 1 according to the embodiment, the main surface side external electrode 411A includes 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. The plating layer 70 is arranged on the base electrode layer 50 and is not arranged on the central side of the stack 10 in the longitudinal direction L relative to the main surface side step portion 800.

[0222] This makes it possible to reduce the amount of the conductive resin layer 60 , and thereby suppress an increase in the size of the external electrode 40 .

[0223] (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 further outward in the longitudinal direction L than the main surface-side step portion 800 .

[0224] This increases the compressive stress caused by plating, improving flexural resistance. Furthermore, by forming a portion with thick plating thickness, substrate mounting properties are improved.

[0225] The multilayer ceramic capacitor 1 of the embodiment may have a structure in which the first external electrode 40A and the second external electrode 40B each include a side surface external electrode having a stepped portion similar to the main surface external electrode.

[0226] That is, the multilayer ceramic capacitor 1 of the embodiment includes: a laminate 10 including a plurality of dielectric layers 20 as ceramic layers and a plurality of internal electrode layers 30 as internal conductive layers alternately laminated in a lamination direction T as a height direction, and including a pair of main surfaces TS opposing each other in the lamination direction T, a pair of end surfaces LS opposing each other in a longitudinal direction L perpendicular to the lamination direction T, and a pair of side surfaces WS opposing each other in a width direction W perpendicular to the lamination direction T and the longitudinal direction L; and a pair of external electrodes 40 disposed at opposite ends of the laminate 10 in the longitudinal direction L, spaced apart from each other.

[0227] The main surface TS includes a first main surface TS1 and a second main surface TS2 that are opposite to each other in the stacking direction T.

[0228] The end surface LS includes a first end surface LS1 and a second end surface LS2 that are opposite to each other in the longitudinal direction L.

[0229] The side surface WS includes a first side surface WS1 and a second side surface WS2 that are opposite to each other in the width direction W.

[0230] The internal electrode layer 30 includes a first internal electrode layer 31 extending to the first end face LS1 as a first internal conductor layer, and a second internal electrode layer 32 extending to the second end face LS2 as a second internal conductor layer, and the external electrode 40 includes a side external electrode arranged on at least one of the first side face WS1 and the second side face WS2, the side external electrode having a surface opposite to the side face WS, the surface having a 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 stack 10 lower than the surface on the outer side of the longitudinal direction L of the stack 10 at a height from the side face WS to the surface, the side step portion having a curved shape convex toward the center of the longitudinal direction L, and extending throughout the width direction on the surface.

[0231] The present invention is not limited to the configuration of the above embodiment, and can be applied with appropriate modifications within the scope of the present invention. In addition, a configuration combining two or more of the desired configurations described in the above embodiment also constitutes the present invention.

[0232] For example, the multilayer ceramic capacitor 1 may be a two-terminal multilayer ceramic capacitor having two external electrodes, or may be a multi-terminal multilayer ceramic capacitor having a large number of external electrodes.

[0233] In the above embodiment, a multilayer ceramic capacitor using dielectric ceramics is exemplified as a multilayer ceramic electronic component. However, the multilayer ceramic electronic component disclosed herein is not limited thereto and can be applied to various multilayer ceramic electronic components, such as piezoelectric components using piezoelectric ceramics, thermistors using semiconductor ceramics, and inductors using magnetic ceramics. Examples of piezoelectric ceramics include PZT (lead zirconate titanate) ceramics, semiconductor ceramics include spinel ceramics, and magnetic ceramics include ferrites.

[0234] The external electrode 40 in the embodiment includes the conductive resin layer 60 , but the external electrode 40 may not include the conductive resin layer 60 .

Claims

1. A multilayer ceramic electronic component comprising: a laminate comprising a plurality of ceramic layers and a plurality of internal conductor layers alternately stacked in a height direction, and comprising a pair of main surfaces opposing each other in the height direction, a pair of end surfaces 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 are disposed at both ends of the stack in the longitudinal direction, separated from each other. The main surface includes a first main surface and a second main surface that are opposite to each other in the height direction. The end faces include a first end face and a second end face that are opposite to each other in the longitudinal direction. The side surfaces include a first side surface and a second side surface that are opposite to each other in the width direction. The internal conductive layer includes a first internal conductive layer extended to the first end surface and a second internal conductive layer extended to the second end surface. The external electrodes include a main surface side external electrode arranged 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 such that the height of the surface on the center side of the stack in the longitudinal direction is lower than the surface on the outer side of the stack in the longitudinal direction in terms of the height from the main surface to the surface. The step portion has a curved shape that is convex toward the center in the longitudinal direction, and extends across the width direction on the surface.

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

3. The multilayer ceramic electronic component according to claim 1 or 2, wherein The main surface side external electrode includes a base electrode layer arranged on the main surface, a plating layer arranged above the base electrode layer, and a conductive resin layer arranged between the base electrode layer and the plating layer. The plating layer is disposed on the base electrode layer, and the conductive resin layer is not disposed, on the center side of the stacked body in the longitudinal direction relative to the step portion.

4. The multilayer ceramic electronic component according to claim 3, wherein The thickness of the plating layer closer to the center of the stacked body in the longitudinal direction than the step portion is greater than the thickness of the plating layer closer to the outer side of the stacked body in the longitudinal direction than the step portion.

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