Multilayer ceramic capacitor

Abstract

Provided is a multilayer ceramic capacitor capable of suppressing a decrease in capacitance.　A multilayer ceramic capacitor 1 comprises: a stacked body 2 having an inner layer portion 11 including a plurality of dielectric layers 14 and a plurality of internal electrodes 15 that are stacked alternately, a first main surface AA and a second main surface AB that face one another in a stacking direction T, a first side surface BA and a second side surface BB that face one another in a width direction W, which is a direction orthogonal to the stacking direction T, and a first end surface CA and a second end surface CB that face one another in a length direction L, which is a direction orthogonal to the stacking direction T and the width direction W; a first external electrode 3A arranged on the first end surface CA; and a second external electrode 3B arranged on the second end surface CB. Each internal electrode 15 has a curved portion 16 which is formed so as to include an end portion in the width direction W of the internal electrode 15 and is curved in a direction approaching a central portion of the stacked body 2 in the stacking direction T.

Description

Multilayer ceramic capacitors

[0001] The present invention relates to a multilayer ceramic capacitor.

[0002] Conventionally, there exists a multilayer ceramic capacitor including a laminate in which dielectric layers and internal electrodes are alternately stacked, and external electrodes provided on both end surfaces of the laminate (see Patent Document 1). Multilayer ceramic capacitors are one of the important electronic components involved in the operation of electronic devices. In recent years, there has been a strong demand for high-quality multilayer ceramic capacitors.

[0003] Japanese Patent Application Laid-Open No. 2003-243249

[0004] However, when laminating the dielectric layers and the internal electrodes, it is difficult to align the widthwise end positions of the internal electrodes. If the widthwise end positions of the internal electrodes are not aligned, regions may be formed at the widthwise end of each internal electrode that do not face adjacent internal electrodes. As a result, the area of ​​the portions where the internal electrodes face each other may be smaller than expected, and the capacitance of the multilayer ceramic capacitor may be smaller than the design value.

[0005] An object of the present invention is to provide a multilayer ceramic capacitor that can suppress a decrease in capacitance.

[0006] In order to solve the above-described problems, the multilayer ceramic capacitor of the present invention comprises a laminate having an inner layer portion including a plurality of dielectric layers and a plurality of internal electrodes stacked alternately, a first main surface and a second main surface opposing each other in the stacking direction, a first side surface and a second side surface opposing each other in a width direction that is a direction perpendicular to the stacking direction, and a first end surface and a second end surface opposing each other in a length direction that is a direction perpendicular to the stacking direction and the width direction, a first external electrode arranged on the first end surface, and a second external electrode arranged on the second end surface, wherein the internal electrodes have curved portions that are formed to include the width direction ends of the internal electrodes and that curve in a direction approaching a center portion of the laminate in the stacking direction.

[0007] According to the present invention, it is possible to provide a multilayer ceramic capacitor capable of suppressing a decrease in capacitance.

[0008] 1 is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment; FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1; FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1; FIG. 4 is an enlarged view of part IV of FIG. 3; and FIG. 5 is an enlarged view of part V of FIG. 2. It is a perspective view showing a state in which a step-eliminating paste is disposed on a ceramic green sheet. It is a cross-sectional view showing a portion around a first lead-out portion in an LT cross-section passing through the center of the width direction of the laminate, where (a) is a diagram showing a case in which the viscosities of the conductive paste and the step-eliminating paste are relatively high, (b) is a diagram showing a case in which the viscosities of the conductive paste and the step-eliminating paste are medium, and (c) is a diagram showing a case in which the viscosities of the conductive paste and the step-eliminating paste are relatively low.

[0009] A multilayer ceramic capacitor 1 according to an embodiment of the present invention will now be described with reference to FIGS.

[0010] (Multilayer Ceramic Capacitor 1) As shown in Fig. 1, the multilayer ceramic capacitor 1 is a multilayer ceramic capacitor with a so-called two-terminal structure. The multilayer ceramic capacitor 1 includes a laminate 2, a first external electrode 3A, and a second external electrode 3B. The laminate 2 is substantially rectangular and has six outer surfaces. The laminate 2 includes an inner layer portion 11 in which a dielectric layer 14 and an internal electrode 15 are stacked. The first external electrode 3A and the second external electrode 3B may be collectively referred to as the "external electrodes 3."

[0011] In this specification, the direction in which the dielectric layers 14 and the internal electrodes 15 are stacked in the multilayer ceramic capacitor 1 is referred to as the stacking direction T. One of the directions perpendicular to the stacking direction T is referred to as the length direction L. The direction perpendicular to both the length direction L and the stacking direction T is referred to as the width direction W.

[0012] Of the six outer surfaces of the laminate 2, a pair of outer surfaces on both sides in the stacking direction T are referred to as the first main surface AA and the second main surface AB, a pair of outer surfaces extending in the stacking direction T and on both sides in the width direction W are referred to as the first side surface BA and the second side surface BB, and a pair of outer surfaces extending in the stacking direction T and on both sides in the length direction L are referred to as the first end surface CA and the second end surface CB.

[0013] The first main surface AA and the second main surface AB may be collectively referred to as "main surfaces A." The first side surface BA and the second side surface BB may be collectively referred to as "side surfaces B." The first end surface CA and the second end surface CB may be collectively referred to as "end surfaces C."

[0014] A cross section parallel to the stacking direction T and the length direction L is referred to as an "LT cross section." The cross section of FIG. 2 is an LT cross section passing through the center of the multilayer ceramic capacitor 1 in the width direction W. A cross section parallel to the stacking direction T and the width direction W is referred to as a "WT cross section." The cross section of FIG. 3 is a WT cross section passing through the center of the multilayer ceramic capacitor 1 in the length direction L.

[0015] (Laminate 2) The laminate 2 has an inner layer portion 11 and a pair of outer layer portions 12 arranged on either side of the inner layer portion 11 in the stacking direction T. The portions where three outer surfaces of the laminate 2 intersect are referred to as "corners." The portions where two outer surfaces of the laminate 2 intersect are referred to as "ridge portions." The corners and ridge portions of the laminate 2 are preferably rounded.

[0016] The outer dimensions of the laminate are, for example, 0.1 mm to 5.0 mm in the lamination direction T, 0.2 mm to 5.7 mm in the length direction L, and 0.1 mm to 5.0 mm in the width direction W. The outer dimensions of the multilayer ceramic capacitor 1 can be measured with a micrometer.

[0017] 2 and 3, the inner layer portion 11 has a plurality of dielectric layers 14 and a plurality of internal electrodes 15. The dielectric layers 14 and the internal electrodes 15 are alternately stacked.

[0018] The dielectric layer 14 is made of a perovskite compound. For example, a dielectric ceramic containing BaTiO3, CaTiO3, SrTiO3, or CaZrO3 as a main component is used as the material for the dielectric layer 14. The material for the dielectric layer 14 may contain, in addition to these main components, a secondary component such as a Mn compound, a Mg compound, a Si compound, a Fe compound, a Cr compound, a Co compound, a Ni compound, an Al compound, a V compound, or a rare earth compound.

[0019] The internal electrodes 15 are formed by sintering a conductive paste containing a metal powder that serves as a conductor, an organic solvent, a binder, and a dispersant on the dielectric layer 14. Metals such as Ni, Cu, Ag, Pd, an Ag-Pd alloy, Au, and Sn are used as the metal powder that serves as a conductor. These metals may be compounds containing these metal elements or alloys with other metals. The total number of internal electrodes 15 is, for example, 200 to 2000.

[0020] The internal electrodes 15 include a plurality of first internal electrodes 15A and a plurality of second internal electrodes 15B. The first internal electrodes 15A are exposed only at the first end face CA. The second internal electrodes 15B are exposed only at the second end face CB. The first internal electrodes 15A and the second internal electrodes 15B are arranged alternately. Of the internal electrodes 15, the one closest to the first main surface AA is, for example, the first internal electrode 15A. Of the internal electrodes 15, the one closest to the second main surface AB is, for example, the second internal electrode 15B. However, this is not limited thereto, and the one closest to the first main surface AA may be the second internal electrode 15B, and the one closest to the second main surface AB may be the first internal electrode 15A.

[0021] The first internal electrode 15A has a first effective portion 15Aa and a first lead portion 15Ab. The first effective portion 15Aa is a portion of the first internal electrode 15A that faces the adjacent second internal electrode 15B. The first lead portion 15Ab is a portion of the first internal electrode 15A that is led out from the first effective portion 15Aa toward the first end face CA.

[0022] The second internal electrode 15B has a second effective portion 15Ba and a second lead portion 15Bb. The second effective portion 15Ba is a portion of the second internal electrode 15B facing the adjacent first internal electrode 15A (first effective portion 15Aa). The second lead portion 15Bb is a portion of the second internal electrode 15B that is led out from the second effective portion 15Ba toward the second end face CB.

[0023] The first internal electrode 15A and the second internal electrode 15B may be collectively referred to as "internal electrodes 15." The first effective portion 15Aa and the second effective portion 15Ba may be collectively referred to as "effective portion 15a."

[0024] (Outer Layer Portion 12) The outer layer portion 12 is formed of the same material as the dielectric layer 14 of the inner layer portion 11. Note that no inner electrode 15 is disposed in the outer layer portion 12.

[0025] (External electrode 3) The first external electrode 3A is provided on the first end face CA. The first external electrode 3A covers not only the first end face CA but also part of the principal face A and part of the side face B. The first external electrode 3A is connected to the first internal electrode 15A.

[0026] The second external electrode 3B is provided on the second end face CB. The second external electrode 3B covers not only the second end face CB but also part of the main face A and part of the side face B. The second external electrode 3B is connected to the second internal electrode 15B.

[0027] The external electrodes 3 each include a base electrode layer 31 disposed on the surface of the laminate 2 and a plating layer 32 disposed on the base electrode layer 31 .

[0028] The base electrode layer 31 is a baked layer containing, for example, a conductive metal and glass. The conductive metal is, for example, nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), gold (Au), an Ag—Pd alloy, or the like, and is preferably Cu.

[0029] The plating layer 32 is made of, for example, one metal selected from the group consisting of Ni, Cu, Ag, Pd, Au, and Sn, or an alloy containing such a metal. The plating layer 32 includes, for example, a first plating layer 321 disposed on the base electrode layer 31 and a second plating layer 322 disposed on the first plating layer 321.

[0030] The first plating layer 321 is, for example, a Ni plating layer. The second plating layer 322 is, for example, a Sn (tin) plating layer. The plating layer 322 may have a single layer structure.

[0031] In the WT cross section of the laminate 2, the structure of the multilayer ceramic capacitor 1 is generally symmetrical in the stacking direction T and in the width direction W. In the following description of the WT cross section of the laminate 2, in principle, the region of the laminate 2 closer to the first main surface AA and closer to the first side surface BA will be described as an example.

[0032] In the LT cross section of the laminate 2, the structure of the multilayer ceramic capacitor 1 is generally symmetrical in the stacking direction T and in the length direction L. When describing the LT cross section of the laminate 2 below, in principle, the region of the laminate 2 closer to the first main surface AA and closer to the first end face CA will be described as an example.

[0033] Here, in adjacent internal electrodes 15, each end portion in the width direction W of the first internal electrode 15A and each end portion in the width direction W of the second internal electrode 15B may not overlap when viewed in the stacking direction T.

[0034] At least one internal electrode 15 has a curved portion 16 that is formed including an end portion of the internal electrode 15 in the width direction W and curves in a direction approaching the center of the stacking direction T of the laminate 2 (see FIG. 3 ). For example, all internal electrodes 15 except for two internal electrodes 15 adjacent to each other across the center of the stacking direction T of the laminate 2 each have a curved portion 16. Two internal electrodes 15 adjacent to each other across the center of the stacking direction T of the laminate 2 do not have curved portions 16.

[0035] The ratio of the total number of internal electrodes 15 having curved portions 16 to the total number of internal electrodes 15 is preferably 60% or more and 80% or less. Of the internal electrodes 15, the internal electrode 15 closest to the first main surface AA and the internal electrode 15 adjacent to that internal electrode 15 preferably each have a curved portion 16. The internal electrodes 15 having curved portions 16 preferably sandwich the internal electrodes 15 not having curved portions 16 from both sides in the stacking direction T. The width direction W dimension of the curved portions 16 is preferably 10 μm or more and 30 μm or less.

[0036] For example, a first curved portion 16A is formed as a curved portion in a portion of each internal electrode 15 including an end portion on one side in the width direction W (more specifically, an end portion of each end portion in the width direction W that is closer to the first side surface BA). The intermediate portion of each internal electrode 15 in the width direction W extends, for example, parallel to the width direction W. In adjacent internal electrodes 15, the first curved portions 16A face each other in a direction intersecting the stacking direction T. Electrostatic capacitance is generated between the facing first curved portions 16A.

[0037] 4, the dielectric layer 14 has a side adjustment region 141 formed in a region overlapping the internal electrode 15 in the stacking direction T and derived from the step-eliminating paste 104 (described later). The side adjustment region 141 has, for example, a first side adjustment region 141A formed between the second internal electrode 15B and the first side surface BA. In the drawing, the region corresponding to the first side adjustment region 141A is shown surrounded by a virtual line. The region of the dielectric layer 14 that does not correspond to the first side adjustment region 141A is derived from the ceramic green sheet 102 (described later).

[0038] The first side surface side adjusting region 141A and the region of the dielectric layer 14 that does not correspond to the first side surface side adjusting region 141A overlap in the stacking direction T. The first side surface side adjusting region 141A abuts or is close to the internal electrode 15.

[0039] In the WT cross section passing through the center of the longitudinal direction L of the laminate 2, of the surfaces of the internal electrode 15 in the stacking direction T, the surface farther from the center of the laminate 2 in the stacking direction T is referred to as the "outer electrode surface 19" (see Figure 3).

[0040] An end portion on one side of the internal electrode 15 in the width direction W is defined as a "first reference point P1." A point on the outer electrode surface 19, which is 20 μm away from the first reference point P1 in the width direction W, is defined as a "second reference point P2." A virtual circle passing through the first reference point P1 and the second reference point P2, whose central angle formed by the radius connecting the center of the circle to the first reference point P1 and the radius connecting the center of the circle to the second reference point P2 is defined as a "virtual circle VC."

[0041] The tangent to the imaginary circle VC at the first reference point P1 is defined as a "first imaginary line L1." An imaginary line connecting a point on the outer electrode surface 19 that is located at ¼ of the width direction W dimension of the outer electrode surface 19 from one end of the outer electrode surface 19 in the width direction W, and a point on the outer electrode surface 19 that is located at ¼ of the width direction W dimension of the outer electrode surface 19 from the other end of the outer electrode surface 19 in the width direction W is defined as a "second imaginary line L2."

[0042] The first virtual line L1 and the second virtual line L2 intersect with each other. The acute angle at which the first virtual line L1 and the second virtual line L2 intersect is defined as the "reference angle θ."

[0043] The reference angle θ of the internal electrode 15 that is closest to the first main surface AA among the internal electrodes 15 is larger than the reference angle θ of the internal electrode 15 that is closest to the center of the stacking direction T of the laminate 2 among the internal electrodes 15.

[0044] The reference angle θ of the internal electrode 15 that is closest to the first main surface AA is, for example, the largest among the reference angles θ of the internal electrodes 15 located in a region closer to the first main surface AA of the laminate 2. The reference angle θ of the internal electrode 15 that is closest to the center of the stacking direction T of the laminate 2 is, for example, the smallest among the reference angles θ of the internal electrodes 15 located in a region closer to the first main surface AA of the laminate 2. For example, the reference angle θ of the internal electrode 15 becomes smaller as the internal electrode 15 becomes closer to the center of the stacking direction T of the laminate 2.

[0045] Of the internal electrodes 15, the reference angle θ of the internal electrode 15 closest to the first main surface AA is preferably 20° or more and 60° or less.

[0046] Each of the first curved portions 16A has an arc shape that protrudes in a direction away from the center of the stacking direction T and width direction W of the laminate 2.

[0047] The radius of curvature of the first curved portion 16A that is closest to the first main surface AA (hereinafter referred to as the "first curved portion 16AA") is smaller than the radius of curvature of the first curved portion 16A that is closest to the center of the stacking direction T of the laminate 2 (hereinafter referred to as the "first curved portion 16AC").

[0048] Of the two first curved portions 16A, the radius of curvature of the first curved portion 16A farther from the center in the stacking direction T of the laminate 2 is smaller than the radius of curvature of the first curved portion 16A closer to the center in the stacking direction T of the laminate 2. The radius of curvature of the first curved portion 16A decreases as the distance between the first curved portion 16A and the center in the stacking direction T of the laminate 2 increases.

[0049] It is assumed that there may be one or two first curved portions 16AC among the first curved portions 16A that are closest to the center in the stacking direction T of the laminate 2. When there are two first curved portions 16AC, in comparing the radii of curvature of different first curved portions 16A, the radius of curvature of the first curved portion 16AC that is closer to the first curved portion 16A being compared is used as the radius of curvature of the first curved portion 16AC.

[0050] Although not shown, each of the first curved portions 16A is formed continuously in the length direction L, for example.

[0051] The configuration of the region of the laminate 2 closer to the second side surface BB is generally the same as the configuration of the region of the laminate 2 closer to the first side surface BA, where "first side surface BA" is replaced with "second side surface BB." The configuration of the region of the laminate 2 closer to the second main surface AB is generally the same as the configuration of the region of the laminate 2 closer to the first main surface AA, where "first main surface AA" is replaced with "second main surface AB."

[0052] However, this is not limited to these, and the configuration of the region of the laminate 2 closer to the second side surface BB may not correspond to the configuration of the region of the laminate 2 closer to the first side surface BA, and the configuration of the region of the laminate 2 closer to the second main surface AB may not correspond to the configuration of the region of the laminate 2 closer to the first main surface AA.

[0053] At least one (more specifically, all) of the internal electrodes 15 has a bent portion 17 formed to include the lead portion 15b (see FIG. 2). For example, at least one (more specifically, all) of the first internal electrodes 15A has a first bent portion 17A formed to include the first lead portion 15Ab.

[0054] Each first bent portion 17A is convex toward the center of the stacking direction T of the laminate 2. Each first bent portion 17A has, for example, a V-shape that is convex toward the center of the stacking direction T of the laminate 2. Each first bent portion 17A is formed, for example, from the first drawn portion 15Ab to the first effective portion 15Aa. In other words, the end of each first bent portion 17A in the width direction W that is closer to the center of the length direction L of the laminate 2 is located in the first effective portion 15Aa. In adjacent first drawn portions 15Ab, the first bent portions 17A face each other in a direction intersecting the stacking direction T. Electrostatic capacitance is generated between the facing first bent portions 17A.

[0055] As shown in Figure 5, in the LT cross section passing through the center of the width direction W of the laminate 2, the relationship between the distance T1 in the stacking direction T between adjacent first internal electrodes 15A and second internal electrodes 15B at the center of the length direction L of the laminate 2 and the distance T2 in the stacking direction T between adjacent first lead portions 15Ab at the first end face CA satisfies T2 > (2 × T1).

[0056] Note that T2 is the distance between the portions of each first lead portion 15Ab that extend parallel to the longitudinal direction L. In other words, T2 is the distance between the portions of each first lead portion 15Ab that do not have the first curved portion 16A.

[0057] The dielectric layer 14 has an end surface side adjusting region 142 formed in the region between adjacent lead portions 15b and derived from step-eliminating paste 104 (described below). The end surface side adjusting region 142 has, for example, a first end surface side adjusting region 142A formed in the region between adjacent first lead portions 15Ab. Note that in the drawings, the region corresponding to the first end surface side adjusting region 142A is shown surrounded by a virtual line. Furthermore, the region of the dielectric layer 14 that does not correspond to the first end surface side adjusting region 142A is derived from the ceramic green sheet 102 (described below).

[0058] The first end surface side adjusting region 142A is located between the second internal electrode 15B and the first end surface CA. The first end surface side adjusting region 142A and the region of the dielectric layer 14 that does not correspond to the first end surface side adjusting region 142A overlap in the stacking direction T. The first end surface side adjusting region 142A abuts the first lead portion 15Ab. The first end surface side adjusting region 142A abuts or is close to, for example, the second internal electrode 15B. For example, a gap V is formed between the first end surface side adjusting region 142A and the second internal electrode 15B.

[0059] The presence of the first end face side adjustment region 142A increases the thickness of the dielectric layer 14 near the end of the second internal electrode 15B on the first end face CA side, thereby ensuring the magnitude of T2 and realizing the relationship T2 > (2 × T1).

[0060] The end surface side adjustment region 142 and the side surface side adjustment region 141 may be collectively referred to as "adjustment regions 141, 142."

[0061] The thickness of the internal electrode 15 closest to the first main surface AA is smaller than the thickness of the internal electrode 15 closest to the center in the stacking direction T of the laminate 2 .

[0062] Of the two internal electrodes 15, the thickness of the internal electrode 15 farther from the center in the stacking direction T of the laminate 2 is smaller than the thickness of the internal electrode 15 closer to the center in the stacking direction T of the laminate 2. The thickness of the internal electrode 15 decreases as the distance between the internal electrode 15 and the center in the stacking direction T of the laminate 2 increases.

[0063] It is assumed that there may be one or two of the internal electrodes 15 that are closest to the center in the stacking direction T of the laminate 2. When there are two of the internal electrodes 15 that are closest to the center in the stacking direction T of the laminate 2, in comparing the thicknesses of the internal electrodes 15, the thickness of the internal electrode 15 that is closest to the internal electrode 15 being compared, of the two internal electrodes 15 that are closest to the center in the stacking direction T of the laminate 2, is determined to be the thickness of the internal electrode 15 that is closest to the center in the stacking direction T of the laminate 2.

[0064] The thickness of the internal electrode 15 is measured at a WT cross section passing through the center of the length direction L of the laminate 2. The multilayer ceramic capacitor 1 is polished to expose a predetermined cross section. The exposed cross section is observed using an optical microscope. The thickness of the internal electrode 15 is measured along five lines parallel to the lamination direction T that divide the internal electrode 15 into six equal parts in the width direction W. The average of these measurements is taken as the thickness of the internal electrode 15.

[0065] In adjacent first internal electrodes 15A, the distance between the first extraction portions 15Ab of each first internal electrode 15A is greater than the sum of the distance from one of the first internal electrodes 15A to the second effective portion 15Ba sandwiched between each first internal electrode 15A and the distance from the other of the first internal electrodes 15A to the second effective portion 15Ba sandwiched between each first internal electrode 15A.

[0066] The distance between the first lead portions 15Ab of adjacent first internal electrodes 15A is the distance between the portions of each first lead portion 15Ab that do not have the first curved portion 16A. In other words, the distance between the first lead portions 15Ab of adjacent first internal electrodes 15A is the distance between the portions of each first lead portion 15Ab that extend parallel to the longitudinal direction L.

[0067] Furthermore, the configuration of the region of the laminate 2 closer to the second end face CB is generally the same as the configuration of the region of the laminate 2 closer to the first end face CA, with "first end face CA" replaced with "second end face CB." However, this is not limited to this, and the configuration of the region of the laminate 2 closer to the second end face CB does not have to correspond to the configuration of the region of the laminate 2 closer to the first end face CA.

[0068] (Method of Manufacturing Multilayer Ceramic Capacitor 1) Next, a method of manufacturing the multilayer ceramic capacitor 1 of the embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 7 is a cross-sectional view showing a portion around the first lead portion 15Ab in an LT cross section passing through the center portion in the width direction W of the laminate 2, in which (a) is a diagram showing a case where the viscosities of the conductive paste and the step-eliminating paste are relatively high, (b) is a diagram showing a case where the viscosities of the conductive paste and the step-eliminating paste are medium, and (c) is a diagram showing a case where the viscosities of the conductive paste and the step-eliminating paste are relatively low.

[0069] (Internal Electrode Pattern Forming Process) First, a ceramic green sheet 102 is prepared by forming a ceramic slurry into a sheet shape. The ceramic green sheet 102 contains ceramic raw materials including a dielectric ceramic material, as well as a binder, a solvent, and the like. A rare earth-containing additive may also be added to the ceramic raw materials. Next, a pattern of the internal electrodes 15 (sometimes simply referred to as the "internal electrode pattern 103") is printed on the ceramic green sheet 102 using a conductive paste. The shape of the internal electrode pattern 103 as viewed in the stacking direction T is, for example, rectangular. This results in a ceramic green sheet 101 for an inner layer portion on which the internal electrodes 15 are arranged. The internal electrode pattern 103 is formed by printing, for example, screen printing, gravure printing, letterpress printing, or the like.

[0070] (Step of arranging dielectric for eliminating step) Next, as shown in Fig. 6, a dielectric paste for eliminating step (sometimes simply referred to as "step elimination paste 104") is arranged on the ceramic green sheet 102. The step elimination paste 104 is arranged on at least a part (more specifically, over the entire area) of the surface of the ceramic green sheet 102 excluding the area where the internal electrode pattern 103 is arranged. The step elimination paste 104 is arranged, for example, at a position abutting or adjacent to an end in the length direction L of the internal electrode pattern 103. The step elimination paste 104 is arranged, for example, at a position abutting or adjacent to an end in the width direction W of the internal electrode pattern 103. The internal electrode pattern 103 is formed by printing, for example, screen printing, gravure printing, letterpress printing or the like.

[0071] The step-eliminating paste 104 contains ceramic raw materials including a dielectric ceramic material, as well as a binder, a solvent, etc. The grains (ceramic particles) of the step-eliminating paste 104 and the grains (ceramic particles) of the ceramic green sheet 102 may be different or the same. The amount of grains of the step-eliminating paste 104 and the amount of grains of the ceramic green sheet 102 may be different or the same.

[0072] Furthermore, the internal electrode pattern 103 is slightly deformed due to its own weight. The peripheral edge of the internal electrode pattern 103 is, for example, an inclined surface. The step-eliminating paste 104 is slightly deformed due to its own weight. The end of the step-eliminating paste 104 on the internal electrode pattern 103 side is, for example, an inclined surface. Therefore, the vicinity of the boundary between the internal electrode pattern 103 and the step-eliminating paste 104 described later is, for example, concave.

[0073] The thickness of the step-eliminating paste 104 and the shape of the end of the step-eliminating paste 104 are adjusted, for example, by adjusting the viscosity of the step-eliminating paste 104. The viscosity of the step-eliminating paste 104 is adjusted, for example, by adjusting the binder content in the step-eliminating paste 104. Similarly, the thickness of the internal electrode pattern 103 and the shape of the end of the internal electrode pattern 103 are adjusted, for example, by adjusting the viscosity of the conductive paste. Also, as an example, the thickness of the step-eliminating paste may be formed to be thicker than the thickness of the internal electrode pattern, so that the step-eliminating paste and the internal electrode pattern are formed without overlapping each other. The step-eliminating paste and the internal electrode pattern may be arranged, for example, with an application interval of 20 μm or more and 100 μm or less.

[0074] The order in which the step of arranging dielectrics to eliminate the step and the step of forming internal electrode patterns can be reversed. For example, the step of arranging dielectrics to eliminate the step may be performed after the step of forming internal electrode patterns.

[0075] (Laminating Process) Next, the ceramic green sheets 101 for the inner layer portion are laminated. The ceramic green sheets 101 for the inner layer portion are laminated so that the internal electrode patterns 103 are shifted by half a pitch between adjacent sheets in the length direction L. Next, ceramic green sheets for the outer layer portion, which will become the outer layer portion 12, are laminated on both sides of the laminated ceramic green sheets 101 for the inner layer portion in the lamination direction T. The ceramic green sheets for the outer layer portion are thermocompression bonded to the ceramic green sheets. This results in a mother block.

[0076] Each outer layer portion 12 may be formed by laminating a plurality of ceramic green sheets or by a single ceramic green sheet. The ceramic green sheet 101 for the inner layer portion and the ceramic green sheet for the outer layer portion may contain different components.

[0077] (Pressing Process) Next, the mother block is pressed in the stacking direction T by means of a hydrostatic press or the like. At this time, for example, of the internal electrode pattern 103 of the first internal electrode 15A, a portion that overlaps in the stacking direction T with the boundary (or gap V) between the internal electrode pattern 13 of the second internal electrode 15B and the step-eliminating paste 104 is bent into a shape that is convex toward the center of the stacking direction T of the mother block. As a result, the end portions in the width direction W of the first internal electrode 15A and the first lead portion 15Ab are each bent toward the center of the stacking direction T of the mother block. Note that, in the second internal electrode 15B as well, the end portions in the width direction W of the second internal electrode 15B and the second lead portion 15Bb are each bent.

[0078] The bending mode of the internal electrode 15 can be adjusted, for example, by adjusting the positional relationship between the step-eliminating paste 104 and the internal electrode pattern 103, by adjusting the thickness of the step-eliminating paste 104 or the thickness of the internal electrode pattern 103, or by adjusting the shape of the end of the step-eliminating paste 104 or the shape of the end of the internal electrode pattern 103.

[0079] 7(a) to 7(c), the higher the viscosity of the step-eliminating paste 104, the thicker the step-eliminating paste 104 (first end face side adjustment region 142A) becomes, and the shape of the end of the step-eliminating paste 104 becomes more sheer. The same applies to the internal electrode pattern 103 (second effective portion 15Ba).

[0080] The greater the thickness of the step-eliminating paste 104 and the thickness of the internal electrode pattern 103, the greater the bending of the first curved portion 16A in the stacking direction T, and the greater the width direction W dimension of the first curved portion 16A. The greater the thickness of the step-eliminating paste 104, the closer the end of the first curved portion 16A to the center in the length direction L of the laminate 2 becomes to the center in the length direction L of the laminate 2. The greater the thickness of the internal electrode pattern 103, the farther the end of the first curved portion 16A to the center in the length direction L of the laminate 2 becomes from the center in the length direction L of the laminate 2.

[0081] Furthermore, in the pressing process, the mother block is pressed from both sides in the stacking direction T. Therefore, the pressure acting on the laminate 2 decreases as the mother block approaches the center of the laminate 2 in the stacking direction T. For this reason, the magnitude of bending of the internal electrodes 15 tends to increase the farther they are from the center of the laminate 2 in the stacking direction T. The thickness of the internal electrodes tends to increase the closer they are to the center of the laminate 2 in the stacking direction T.

[0082] (Mother Block Cutting Process) Next, the mother block is cut along cutting lines corresponding to the dimensions of the laminate. The mother block is cut, for example, in the length direction L and the width direction W. This results in multiple rectangular blocks (referred to as "laminated chips"). It is preferable that the corners and ridges of the laminated chips are rounded, for example, by barrel polishing.

[0083] (Laminate Firing Step) Next, the laminated chip is heated at a predetermined firing temperature in a nitrogen atmosphere for a predetermined time, thereby obtaining the laminate 2.

[0084] (Base electrode layer forming process) Next, a base electrode layer 31 is formed on each end face C of the laminate 2. A conductive paste containing glass and metal is applied onto the laminate 2. Each base electrode layer 31 is formed, for example, so as to cover each end face C, a portion of each main face A, and a portion of each side face B. However, this is not limited to this, and each base electrode layer 31 may be disposed only on each end face C.

[0085] (Base Electrode Layer Baking Process) Next, the laminate 2 on which the base electrode layer 31 has been formed is heated in a nitrogen atmosphere at a predetermined baking temperature for a predetermined time, thereby baking the base electrode layer 31 to the laminate 2. Note that the laminate baking process and the base electrode layer baking process may be performed simultaneously after the material for the base electrode layer 31 has been placed on the laminate chip.

[0086] (Plating Process) Next, the plating layer 32 is formed on the base electrode layer 31. First, the first plating layer 321 is formed on the base electrode layer 31. Next, the second plating layer 322 is formed on the first plating layer 321. The first plating layer 321 is formed by, for example, Ni plating. The second plating layer 322 is formed by, for example, Sn plating. The first plating layer 321 and the second plating layer 322 are formed sequentially by, for example, electrolytic plating.

[0087] As a result of the above, the multilayer ceramic capacitor 1 shown in FIG. 1 is obtained.

[0088] (Effects of the Embodiment) According to the present embodiment, the following effects can be obtained.

[0089] The multilayer ceramic capacitor 1 includes an inner layer portion 11 including a plurality of alternately stacked dielectric layers 14 and a plurality of internal electrodes 15, a laminate 2 having first and second main surfaces AA and AB facing in a stacking direction T, first and second side surfaces BA and BB facing in a width direction W that is a direction perpendicular to the stacking direction T, and first and second end surfaces CA and CB facing in a length direction L that is a direction perpendicular to the stacking direction T and the width direction W, a first external electrode 3A arranged on the first end surface CA, and a second external electrode 3B arranged on the second end surface CB. The internal electrode 15 has a curved portion 16 that is formed including an end portion of the internal electrode 15 in the width direction W and curves in a direction approaching the center of the laminate 2 in the stacking direction T.

[0090] In adjacent internal electrodes 15, it is preferable that the ends of the first internal electrode 15A and the second internal electrode 15B in the width direction W are aligned in the width direction W. However, stacking the dielectric layers 14 and the internal electrodes 15 to achieve this state is extremely difficult. However, with this configuration, even if adjacent internal electrodes 15 are misaligned in the width direction W, it is easy to make the curved portion 16 of one internal electrode 15 face the other internal electrode 15. When the curved portion 16 of one internal electrode 15 faces the other internal electrode 15, capacitance can be generated at the facing portion. This prevents a decrease in capacitance even if the internal electrodes 15 are misaligned from their desired positions. Therefore, a multilayer ceramic capacitor 1 capable of ensuring a suitable capacitance can be provided.

[0091] Furthermore, this configuration makes it easier to ensure the distance between the ends of the internal electrodes 15 in the width direction W and the side surfaces B of the laminate 2. This makes it possible to prevent external forces from acting on the internal electrodes 15 and to prevent moisture from penetrating, thereby suppressing the occurrence of defects inside the laminate 2. This improves the reliability of the multilayer ceramic capacitor 1.

[0092] Even if the position of the internal electrode 15 is shifted during the manufacturing process, it is possible to easily ensure the capacitance and suppress the occurrence of internal defects, thereby suppressing a decrease in the production efficiency of the multilayer ceramic capacitor 1.

[0093] The internal electrode 15 has a first internal electrode 15A connected to the first external electrode 3A and a second internal electrode 15B connected to the second external electrode 3B, and the relationship between the distance T1 in the stacking direction T between adjacent first internal electrodes 15A and second internal electrodes 15B at the center of the longitudinal direction L of the laminate 2 and the distance T2 in the stacking direction T between adjacent first extraction portions 15Ab at the first end face CA satisfies T2 > 2 × T1.

[0094] This configuration can prevent the occurrence of steps near the boundary between the effective portion and the lead portion due to the thickness of the internal electrode 15. This makes it possible to effectively prevent the occurrence of structural defects.

[0095] In a cross section parallel to the stacking direction T and width direction W of the laminate 2, of the surfaces of the internal electrode 15 in the stacking direction T, the surface farther from the center of the laminate 2 in the stacking direction T is defined as an outer electrode surface 19, of the ends of the internal electrode 15 in the width direction W, the end closer to the first side surface BA is defined as a first reference point P1, a point on the outer electrode surface 19 at a distance of 20 μm in the width direction W from the first reference point P1 is defined as a second reference point P2, and a virtual circle passing through the first reference point P1 and the second reference point P2, the radius of which connects the center of the circle with the first reference point P1 and the length of the circle is defined as a radius of the circle. A virtual circle VC is a circle whose center is π / 8 and whose radius is a line connecting the center and the second reference point P2. A first virtual line L1 is a tangent to the virtual circle VC at the first reference point P1. A second virtual line L2 is a virtual line connecting a point on the outer electrode surface 19 that is ¼ of the width direction W dimension of the outer electrode surface 19 from one end of the outer electrode surface 19 in the width direction W with a point on the outer electrode surface 19 that is ¼ of the width direction W dimension of the outer electrode surface 19 from the other end of the outer electrode surface 19 in the width direction W. The first virtual line L1 and the second virtual line L2 intersect with each other. The acute angle at which the first virtual line L1 and the second virtual line L2 intersect is defined as a reference angle θ. The reference angle θ of the internal electrode 15 that is closest to the first main surface AA among the internal electrodes 15 is larger than the reference angle θ of the internal electrode 15 that is closest to the center of the stacking direction T of the laminate 2 among the internal electrodes 15.

[0096] It is believed that defects inside the laminate 2 are more likely to occur in regions of the laminate 2 closer to the outer surface. However, with this configuration, it is easier to ensure the distance between the internal electrode 15 and the side surface B in regions of the laminate 2 closer to the main surface A. This makes it possible to more effectively suppress defects inside the laminate 2.

[0097] Furthermore, with this configuration, the connection between the internal electrodes 15 and the dielectric layers 14 can be strengthened in the region of the laminate 2 closer to the main surface A. This makes it possible to prevent the internal electrodes 15 from peeling off.

[0098] The reference angle θ of the internal electrode 15 that is closest to the first main surface AA is equal to or greater than 20° and equal to or less than 60°.

[0099] If the reference angle θ is too small, the opposing area between the internal electrodes 15 cannot be increased sufficiently, which may result in an inability to ensure capacitance. Furthermore, the distance between the internal electrodes 15 and the side surface B may not be sufficiently secured, which may result in an increased likelihood of internal defects. On the other hand, if the reference angle θ is too large, the ends of adjacent internal electrodes 15 in the width direction W may be too close to each other, which may result in an increased likelihood of short-circuiting between the internal electrodes 15. However, by setting the reference angle θ to be between 20° and 60°, it is possible to prevent these defects from occurring, thereby making it easier to ensure capacitance while suppressing a decrease in reliability.

[0100] The curved portion 16 is arc-shaped, and the radius of curvature of the curved portion 16 closest to the first main surface AA is smaller than the radius of curvature of the curved portion 16 closest to the center of the stacking direction T of the laminate 2.

[0101] In the region of the laminate 2 close to the principal surface A, contact between the internal electrodes 15 due to an external impact is more likely to occur than in the region of the laminate 2 near the center in the stacking direction T of the laminate 2. However, with this configuration, even if the reference angle θ is relatively large in the curved portion 16 closest to the first principal surface AA, it is possible to easily ensure the distance between adjacent curved portions 16. This makes it possible to prevent adjacent curved portions 16 from contacting each other and causing a short circuit.

[0102] The internal electrode 15 has an effective portion 15a which is a portion facing an adjacent internal electrode 15, and an extraction portion 15b which is a portion extracted from the effective portion 15a toward either the first end face CA or the second end face CB, and also has a bending portion 17 formed including the extraction portion 15b.

[0103] According to this configuration, the ratio of the internal electrodes 15 to the dielectric layers 14 can be increased in the region of the laminate 2 that is closer to the end face C than the effective portion 15a. This makes it possible to suppress peeling of the internal electrodes 15 originating from inside the laminate 2.

[0104] Furthermore, with this configuration, an anchor effect can be generated between the internal electrode 15 and the dielectric layer 14 near the boundary between the lead portion 15b and the effective portion 15a, thereby making it possible to suppress peeling of the internal electrode 15 originating from inside the laminate 2.

[0105] The bent portions 17 adjacent to each other in the stacking direction T are each convex toward the center of the stack 2 in the stacking direction T.

[0106] According to this configuration, the bent portions 17 can be prevented from coming too close to each other, and therefore, the occurrence of short circuits between the internal electrodes 15 can be prevented.

[0107] The thickness of the internal electrode 15 closest to the first main surface AA is smaller than the thickness of the internal electrode 15 closest to the center in the stacking direction T of the laminate 2 .

[0108] This configuration can prevent discontinuity of the internal electrodes 15 near the center of the laminate 2 in the stacking direction T. This can improve the ESR and the withstand voltage characteristics.

[0109] The width W of the curved portion 16 is preferably 10 μm or more and 30 μm or less.

[0110] If the curved portion 16 is 10 μm or more and 30 μm or less, the area that forms the capacitance can be maximized, and even a multilayer ceramic capacitor 1 with poor lamination precision can still operate normally.

[0111] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various changes and modifications are possible.

[0112] In the above embodiment, the reference angle of the internal electrode 15 is smaller for the internal electrode 15 closer to the center of the laminate 2 in the lamination direction T, but this is not limitative.

[0113] In the above embodiment, the first curved portion 16A has an arc shape that is convex in the direction away from the center of the stacking direction T and the width direction W of the laminate 2, but the shape of the curved portion 16 is not limited to this. The curved portion 16 may have, for example, an oblique straight line shape that approaches the center of the stacking direction T of the laminate 2 as it moves away from the center of the width direction W of the laminate 2, or may have a broken line shape.

[0114] In the above embodiment, the first bent portion 17A has a V-shape that protrudes toward the center of the stacking direction T of the laminate 2, but the shape of the bent portion 17 is not limited to this. The bent portion 17 may have, for example, a U-shape. The bent portion 17 may have, for example, an oblique linear shape that approaches the center of the stacking direction T of the laminate 2 as it moves away from the center of the width direction W of the laminate 2. In other words, the bent portion 17 does not have to have an apex in the middle of the width direction W.

[0115] In the above embodiment, the first bent portion 17A is formed from the first lead portion 15Ab to the first effective portion 15Aa, but this is not limited thereto. For example, the entire bent portion 17 may be formed in the lead portion 15b. The range in which the bent portion 17 is formed in the internal electrode 15 can be adjusted by adjusting the thickness of the internal electrode pattern 103 and the thickness of the step-eliminating paste 104, respectively.

[0116] In the above embodiment, the thickness of the internal electrode 15 is smaller for internal electrodes 15 with a larger distance between the internal electrode 15 and the center of the laminate 2 in the stacking direction T, but this is not limited to this.

[0117] In the above embodiment, the bending of the internal electrode 15 is caused by the step-eliminating paste 104, but this is not limiting. For example, the bending of the internal electrode 15 may be formed by pressing a pressing member against the mother block in the stacking direction. For example, the pressing member is pressed into a position on the surface of the mother block that overlaps in the stacking direction with the portion of the internal electrode 15 where the bending is desired. As the pressing member is pressed into the mother block, the internal electrode 15 is bent toward the center of the mother block in the stacking direction. For example, the pressing member is pressed into the mother block simultaneously from both sides in the stacking direction. The shape of the pressing member can be changed as needed to match the desired curved shape of the internal electrode 15.

[0118] In the above embodiment, the first lead portion 15Ab has the first bent portion 17A in the WT cross section passing through the center of the width direction W of the laminate 2, but the bent portion 17A is not an essential component. The first lead portion 15Ab does not necessarily have to be bent.

[0119] The adjustment regions 141, 142 may be in contact with or close to the internal electrode 15 adjacent to the adjustment regions 141, 142 in a direction perpendicular to the stacking direction T. The gap V does not necessarily have to be formed in the laminate 2.

[0120] The present invention also includes the following combinations:

[0121] <1> A multilayer ceramic capacitor comprising: a laminate having an inner layer portion including a plurality of alternately stacked dielectric layers and a plurality of internal electrodes; first and second main surfaces opposing each other in a stacking direction; first and second side surfaces opposing each other in a width direction that is a direction perpendicular to the stacking direction; and first and second end surfaces opposing each other in a length direction that is a direction perpendicular to the stacking direction and the width direction; first external electrodes arranged on the first end surfaces; and second external electrodes arranged on the second end surfaces, wherein the internal electrodes have curved portions that are formed to include the width direction ends of the internal electrodes and that curve in a direction approaching a center of the laminate in the stacking direction.

[0122] <2> The multilayer ceramic capacitor according to <1>, wherein the internal electrodes include a first internal electrode connected to the first external electrode and a second internal electrode connected to the second external electrode, and the relationship between the stacking direction distance T1 between adjacent first internal electrodes and second internal electrodes at the longitudinal center of the laminate and the stacking direction distance T2 between adjacent first lead portions at the first end face satisfies T2>2×T1.

[0123] <3> In a cross section parallel to the stacking direction and the width direction of the laminate, among the surfaces of the internal electrode in the stacking direction, a surface farther from the center of the laminate in the stacking direction is defined as an outer electrode surface; among the ends of the internal electrode in the width direction, an end closer to the first side surface is defined as a first reference point; a point on the outer electrode surface, the distance in the width direction between the point and the first reference point being 20 μm, is defined as a second reference point; a virtual circle passing through the first reference point and the second reference point, the central angle formed by the radius connecting the center of the circle and the first reference point and the radius connecting the center of the circle and the second reference point is π / 8, is defined as a virtual circle; a tangent to the virtual circle at the first reference point is defined as a first virtual line; a second virtual line connecting a point on the outer electrode surface that is a distance from an end of one side in the width direction of the outer electrode surface by ¼ of the width direction dimension of the outer electrode surface to a point on the outer electrode surface that is a distance from an end of the other side in the width direction of the outer electrode surface by ¼ of the width direction dimension of the outer electrode surface; the first virtual line and the second virtual line intersect with each other; and an acute angle at which the first virtual line and the second virtual line intersect is defined as a reference angle. The reference angle of the internal electrode that is closest to the first main surface among the internal electrodes is larger than the reference angle of the internal electrode that is closest to a center of the laminate in the stacking direction among the internal electrodes.

[0124] <4> The multilayer ceramic capacitor according to <3>, wherein the reference angle of the internal electrode that is closest to the first main surface among the internal electrodes is 20° or more and 60° or less.

[0125] <5> The multilayer ceramic capacitor according to any one of <1> to <4>, wherein the curved portions are arc-shaped, and a radius of curvature of the curved portion closest to the first main surface is smaller than a radius of curvature of the curved portion closest to a center portion of the laminate in the stacking direction.

[0126] <6> The multilayer ceramic capacitor according to any one of <1> to <5>, wherein the internal electrodes have effective portions that are portions facing the adjacent internal electrodes, and lead portions that are portions that are led from the effective portions toward either the first end face or the second end face, and have bent portions that are formed to include the lead portions.

[0127] <7> The multilayer ceramic capacitor according to <6>, wherein the bent portions adjacent to each other in the stacking direction are each convex toward a center portion of the laminate in the stacking direction.

[0128] <8> The multilayer ceramic capacitor according to any one of <1> to <7>, wherein the thickness of the internal electrode closest to the first main surface is smaller than the thickness of the internal electrode closest to a center portion of the laminate in the stacking direction.

[0129] REFERENCE SIGNS LIST 1 Multilayer ceramic capacitor 2 Laminate 3A First external electrode 3B Second external electrode 14 Dielectric layer 15 Internal electrode 15A First internal electrode 15Aa First effective portion 15Ab First lead portion 16 Curved portion 16A First curved portion 17 Bent portion 17A First bent portion 19 External electrode surface AA First main surface AB Second main surface BA First side surface BB Second side surface CA First end surface CB Second end surface F1 First region L1 First virtual line L2 Second virtual line P1 First reference point P2 Second reference point VC Virtual circle θ Reference angle

Claims

1. A multilayer ceramic capacitor comprising: a laminate having an inner layer portion including a plurality of alternately stacked dielectric layers and a plurality of internal electrodes; first and second main surfaces facing each other in the stacking direction; first and second side surfaces facing each other in a width direction that is a direction perpendicular to the stacking direction; and first and second end surfaces facing each other in a length direction that is a direction perpendicular to the stacking direction and the width direction; a first external electrode disposed on the first end surface; and a second external electrode disposed on the second end surface, wherein the internal electrodes have curved portions that are formed to include the width direction ends of the internal electrodes and curve in a direction approaching the center of the laminate in the stacking direction.

2. The multilayer ceramic capacitor according to claim 1, wherein the internal electrodes include a first internal electrode connected to the first external electrode and a second internal electrode connected to the second external electrode, and the relationship between the stacking direction distance T1 between adjacent first internal electrodes and second internal electrodes at the longitudinal center of the laminate and the stacking direction distance T2 between adjacent first lead portions at the first end face satisfies T2 > 2 × T1.

3. In a cross section parallel to the stacking direction and the width direction of the laminate, of each face of the internal electrode in the stacking direction, the face farther from the center of the laminate in the stacking direction is defined as an outer electrode face, of each end of the internal electrode in the width direction, the end closer to the first side face is defined as a first reference point, a point on the outer electrode face, the distance in the width direction between the point and the first reference point being 20 μm, is defined as a second reference point, a virtual circle is defined as a circle that passes through the first reference point and the second reference point, the central angle formed by the radius connecting the center of the circle to the first reference point and the radius connecting the center of the circle to the second reference point is π / 8, and a tangent to the virtual circle at the first reference point is defined as a first virtual line, 3. The multilayer ceramic capacitor according to claim 1, wherein: a virtual line connecting a point on the outer electrode surface that is a quarter of the width direction dimension of the outer electrode surface from an end portion on one side of the width direction of the outer electrode surface, and a point on the outer electrode surface that is a quarter of the width direction dimension of the outer electrode surface from an end portion on the other side of the width direction of the outer electrode surface is defined as a second virtual line; the first virtual line and the second virtual line intersect with each other; and an acute angle at which the first virtual line and the second virtual line intersect is defined as a reference angle; and the reference angle of the internal electrode that is closest to the first main surface among the internal electrodes is larger than the reference angle of the internal electrode that is closest to a center portion of the laminate in the stacking direction among the internal electrodes.

4. The multilayer ceramic capacitor according to claim 3, wherein the reference angle of the internal electrode that is closest to the first main surface is 20° or more and 60° or less.

5. A multilayer ceramic capacitor according to any one of claims 1 to 4, wherein the curved portion is arc-shaped, and the radius of curvature of the curved portion closest to the first principal surface is smaller than the radius of curvature of the curved portion closest to the center of the laminate in the stacking direction.

6. A multilayer ceramic capacitor according to any one of claims 1 to 5, wherein the internal electrodes have effective portions that face adjacent internal electrodes, and lead portions that are led from the effective portions toward either the first end face or the second end face, and also have bent portions formed to include the lead portions.

7. The multilayer ceramic capacitor according to claim 6, wherein the bent portions adjacent to each other in the stacking direction are each convex toward the center of the laminate in the stacking direction.

8. A multilayer ceramic capacitor according to any one of claims 1 to 7, wherein the thickness of the internal electrode closest to the first main surface is smaller than the thickness of the internal electrode closest to the center of the laminate in the stacking direction.

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