Multilayer ceramic capacitor

Abstract

Provided is a multilayer ceramic capacitor which has further improved reliability. In a multilayer ceramic capacitor (1), a laminate (2) has an inner layer part (10) in which dielectric layers (20) and internal electrodes are alternately layered. In cross sections in the width direction (W) and the thickness direction (T), the distance between the end parts in the width direction (W) of the internal electrodes that are mutually adjacent in the thickness direction (T) is larger than the distance between the internal electrodes that are mutually adjacent in the thickness direction (T) at the center in the width direction (W) of the inner layer part (10), and a first virtual line (511) connecting the end parts in the width direction (W) of the internal electrodes is projecting toward the center in the width direction W of the inner layer part (10).

Description

Multilayer ceramic capacitors

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

[0002] Multilayer ceramic capacitors, which include a laminate in which dielectric layers and internal electrodes are alternately stacked, and external electrodes connected to the internal electrodes, are one of the important electronic components used in a variety of electronic devices. Patent Document 1 discloses a multilayer ceramic capacitor in which the approximate curves of the ends of the internal electrodes are nearly straight lines.

[0003] International Publication No. WO 2024 / 062980

[0004] In the multilayer ceramic capacitor of Patent Document 1, the ends of the internal electrodes are aligned in the lamination direction. The ends of the internal electrodes are areas where an electric field is likely to concentrate. In the multilayer ceramic capacitor of Patent Document 1, the areas where an electric field is likely to concentrate are aligned, making the electric field more likely to concentrate. Therefore, the multilayer ceramic capacitor of Patent Document 1 has a problem in that the reliability of the multilayer ceramic capacitor, such as withstand voltage, is not sufficiently improved.

[0005] The present invention has been made to solve the above problems, and an object of the present invention is to provide a multilayer ceramic capacitor with improved reliability.

[0006] The multilayer ceramic capacitor of the present invention comprises a laminate including a plurality of laminated dielectric layers and a plurality of internal electrodes, the laminate having first and second main surfaces facing each other in a stacking direction of the dielectric layers and the internal electrodes, first side surfaces facing each other in a width direction perpendicular to the stacking direction, and first end surfaces facing each other in a length direction perpendicular to the stacking direction and the width direction, and external electrodes electrically connected to the internal electrodes and provided on a surface of the laminate, the laminate having an inner layer portion in which the dielectric layers and the internal electrodes are alternately stacked, and in a cross section in the width direction and the stacking direction, the distance between the ends of the internal electrodes adjacent to each other in the stacking direction is greater than the distance at the width direction centers of the inner layer portions of the internal electrodes adjacent to each other in the stacking direction, and a first imaginary line connecting the ends of the internal electrodes is convex toward the width direction center of the inner layer portion.

[0007] According to the present invention, it is possible to provide a multilayer ceramic capacitor with improved reliability.

[0008] FIG. 1 is an external perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line 2001-2001 in FIG. 1. FIG. 3 is a cross-sectional view taken along line 2002-2002 in FIG. 1. FIG. 4 is a cross-sectional view taken along line 2003-2003 in FIG. 1. FIG. 5 is a cross-sectional view taken along line 2004-2004 in FIG. 1. FIG. 6 is a cross-sectional view taken along line 2004-2004 in FIG. 1. FIG. 7 is a cross-sectional view taken along line 2004-2004 in FIG. 1 in the length direction and lamination direction of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 8 is a cross-sectional view taken along line 2004-2004 in a multilayer ceramic capacitor showing a modification of an embodiment of the present invention. FIG. 9 is a cross-sectional view taken along line 2004-2004 in a multilayer ceramic capacitor showing another modification of an embodiment of the present invention. FIG. 10 is a diagram showing an example of a manufacturing method of an embodiment of the present invention.

[0009] (Multilayer Ceramic Capacitor) A multilayer ceramic capacitor 1 according to one embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the appearance of a multilayer ceramic capacitor 1 according to an embodiment of the present invention.

[0010] 1, the multilayer ceramic capacitor 1 has a substantially rectangular parallelepiped shape. The multilayer ceramic capacitor 1 includes a laminate 2 having a substantially rectangular parallelepiped shape and a pair of external electrodes disposed at opposite ends of the laminate 2 and spaced apart from each other.

[0011] The arrow T in Fig. 1 indicates the lamination direction T of the multilayer ceramic capacitor 1 and the laminate 2. The arrow L indicates the length direction L, which is perpendicular to the lamination direction T of the multilayer ceramic capacitor 1 and the laminate 2. The arrow W indicates the width direction W, which is perpendicular to the lamination direction T and length direction L of the multilayer ceramic capacitor 1 and the laminate 2. The lamination direction T, length direction L, and width direction W are perpendicular to one another. The arrows T, L, and L indicate the same directions as those described above in figures other than Fig. 1 as well.

[0012] One of the pair of external electrodes is provided at one end of the laminate 2 in the length direction L. The other of the pair of external electrodes is provided at the other end of the laminate 2 in the length direction L. One of the external electrodes is referred to as a first external electrode 41. The other external electrode is referred to as a second external electrode 42.

[0013] (Laminate) The laminate 2 will be described with reference to Figs. 2, 3, and 4 in addition to Fig. 1. Fig. 2 is a cross-sectional view taken along line 2001-2001 of Fig. 1. Fig. 3 is a cross-sectional view taken along line 2002-2002 of Fig. 1. Fig. 4 is a cross-sectional view taken along line 2003-2003 of Fig. 1. As shown in Fig. 2, the laminate 2 includes a plurality of laminated dielectric layers 20 and a plurality of internal electrodes. The internal electrodes include a first internal electrode 31 and a second internal electrode 32.

[0014] The two surfaces of the laminate 2 that face each other in the stacking direction T are called the first main surface 3 and the second main surface 4. The two surfaces of the laminate 2 that face each other in the width direction W are called the first side surface 5 and the second side surface 6. The two surfaces of the laminate 2 that face each other in the length direction L are called the first end surface 7 and the second end surface 8.

[0015] The laminate 2 has a rectangular parallelepiped shape. The portions where three faces of the laminate 2 intersect are called corners. The portions where two faces of the laminate 2 intersect are called ridges. The corners and ridges of the laminate 2 are preferably rounded. Some or all of the main surfaces, side surfaces, and end surfaces may have irregularities formed thereon.

[0016] (Dielectric Layer) The total number of dielectric layers 20 included in the laminate 2 is preferably 100 or more and 1500 or less. More preferably, the total number is 200 or more and 1500 or less.

[0017] The ceramic material contained in the dielectric layer 20 is, for example, BaTiO ３ , CaTiO ３ , SrTiO ３ , CaZrO ３ The ceramic material may be a dielectric ceramic having the above-mentioned main component and an auxiliary component added thereto. Examples of the auxiliary component include a Mn compound, an Fe compound, a Cr compound, a Co compound, a Ni compound, and an Mg compound.

[0018] The preferred thickness of one dielectric layer 20 is 0.5 μm or more and 10 μm or less.

[0019] The size of the laminate 2 is not particularly limited. The preferred length of the laminate 2 in the longitudinal direction L is 0.2 mm or more and 10 mm or less. The preferred length of the laminate 2 in the width direction W is 0.1 mm or more and 10 mm or less. The preferred length of the laminate 2 in the stacking direction T is 0.1 mm or more and 5 mm or less.

[0020] (Internal Electrodes) The internal electrodes will now be described. The internal electrodes include a plurality of first internal electrodes 31 and a plurality of second internal electrodes 32. The first internal electrodes 31 are internal electrodes exposed at the first end face 7. The second internal electrodes 32 are internal electrodes exposed at the second end face 8. Figure 3 shows the first internal electrodes 31.

[0021] The first internal electrode 31 has a first opposing portion 33 and a first lead portion 35. The first opposing portion 33 is a portion of the first internal electrode 31 that faces the second internal electrode 32. The first lead portion 35 is a portion of the first internal electrode 31 that is led from the first opposing portion 33 to the first end face 7. The second internal electrode 32 has a second opposing portion 34 and a second lead portion 36. The second opposing portion 34 is a portion of the second internal electrode 32 that faces the first internal electrode 31. The second lead portion 36 is a portion of the second internal electrode 32 that is led from the second opposing portion 34 to the second end face 8.

[0022] When the internal electrodes are viewed in cross section in the length direction L and width direction W of the laminate 2, the portions located at the corners of the external shape of the internal electrodes are called corner portions.

[0023] The shape of the first facing portion 33 is not particularly limited. A preferred shape of the first facing portion 33 is a rectangle. The corners of the first facing portion 33 may be rounded, or the corners of the first facing portion 33 may be tapered obliquely. The shape of the first facing portion 33 may be tapered, with an inclination increasing in either direction in the length direction L.

[0024] The shape of the second facing portion 34 is not particularly limited. A preferred shape of the second facing portion 34 is a rectangular shape. The corners of the second facing portion 34 may be rounded, or the corners of the second facing portion 34 may be tapered and obliquely formed. The shape of the second facing portion 34 may be tapered, with an inclination increasing in either direction in the length direction L.

[0025] The shape of the first lead portion 35 is not particularly limited. A preferred shape of the first lead portion 35 is a rectangle. The corners of the first lead portion 35 may be rounded or may be tapered and obliquely formed. The shape of the first lead portion 35 may be tapered, with an inclination increasing in either direction in the length direction L.

[0026] The shape of the second lead portion 36 is not particularly limited. A preferred shape of the second lead portion 36 is a rectangular shape. The corners of the second lead portion 36 may be rounded or may be tapered and obliquely formed. The shape of the second lead portion 36 may be tapered, with an inclination increasing in either direction in the length direction L.

[0027] The width in the width direction W of the first opposing portion 33 may be the same as or different from the width in the width direction W of the first lead portion 35. The width in the width direction W of the second opposing portion 34 may be the same as or different from the width in the width direction W of the second lead portion 36.

[0028] The first internal electrode 31 and the second internal electrode 32 may be made of an appropriate conductive material, for example, a metal such as Ni, Cu, Ag, Pd, or Au, or an alloy containing at least one of these metals, such as an Ag-Pd alloy.

[0029] The preferred thickness of each of the first internal electrode 31 and the second internal electrode 32 is, for example, about 0.2 μm or more and 2.0 μm or less.

[0030] A preferred total number of the first internal electrodes 31 and the second internal electrodes 32 is 15 or more and 800 or less.

[0031] (Outer Layer Portion and Inner Layer Portion) The division of the laminate 2 in the stacking direction T will be described. As shown in Figures 2 and 4, the laminate 2 is divided into an inner layer portion 10 and an outer layer portion in the stacking direction T. The outer layer portion includes a first outer layer portion 11 and a second outer layer portion 12.

[0032] The inner layer portion 10 is a portion of the laminate 2 in the stacking direction T between the position of the internal electrode closest to the first main surface 3 and the position of the internal electrode closest to the second main surface 4 .

[0033] The first outer layer portion 11 is a portion of the laminate 2 between the first main surface 3 and the position of the internal electrode closest to the first main surface 3 in the stacking direction T. In other words, the first outer layer portion 11 is a portion of the laminate 2 between the inner layer portion 10 and the first main surface 3.

[0034] The second outer layer portion 12 is a portion of the laminate 2 between the second main surface 4 and the position of the internal electrode closest to the second main surface 4 in the stacking direction T. In other words, the second outer layer portion 12 is a portion of the laminate 2 between the inner layer portion 10 and the second main surface 4.

[0035] (Core portion and side gap portion) The division of the laminate 2 in the width direction W will be described. As shown in Figures 3 and 4, the laminate 2 is divided into a core portion 25 and a side gap portion in the width direction W. The side gap portion includes a first side gap portion 15 and a second side gap portion 16.

[0036] The core portion 25 is a portion of the laminate 2 in the width direction W where an internal electrode is provided. The first side gap portion 15 is a portion of the laminate 2 between the core portion 25 and the first side surface 5 in the width direction W. The second side gap portion 16 is a portion of the laminate 2 between the core portion 25 and the second side surface 6 in the width direction W. No internal electrode is provided in the side gap portion. Only the dielectric layer 20 is provided in the side gap portion. The side gap portion is also called a W gap.

[0037] (Valid Portion and Invalid Portion) The division of the core portion 25 in the stacking direction T will be described. As shown in Fig. 4, the core portion 25 is divided into a valid portion 26 and an invalid portion in the stacking direction T. The invalid portion includes a first invalid portion 28 and a second invalid portion 29.

[0038] The effective portion 26 is the portion of the core portion 25 in which the first internal electrode 31 or the second internal electrode 32 is arranged in the stacking direction T. The first ineffective portion 28 is the portion of the core portion 25 between the effective portion 26 and the first main surface 3 in the stacking direction T. The second ineffective portion 29 is the portion of the core portion 25 between the effective portion 26 and the second main surface 4 in the stacking direction T. No internal electrodes are provided in the ineffective portion. Only the dielectric layer 20 is provided in the ineffective portion.

[0039] (Electrode opposing portion) In the core portion 25, the portion where the first internal electrode 31 and the second internal electrode 32 overlap is called the electrode opposing portion 38. In the electrode opposing portion 38, the first opposing portion 33 and the second opposing portion 34 overlap. In the multilayer ceramic capacitor 1, capacitance is formed when the opposing portions of the internal electrodes face each other with the dielectric layer 20 interposed therebetween, thereby exhibiting the characteristics of the capacitor. In other words, capacitance is formed in the electrode opposing portion 38.

[0040] (L Gaps) In the core portion 25, the portion between the electrode opposing portion 38 and the end face is called the L gap. The lead portions of the internal electrodes are arranged in the L gaps. As shown in FIGS. 2 and 3 , the L gaps include a first L gap 18 and a second L gap 19. The first L gap 18 is the portion between the electrode opposing portion 38 and the first end face 7. The first lead portion 35 is arranged in the first L gap 18. The second L gap 19 is the portion between the electrode opposing portion 38 and the second end face 8. The second lead portion 36 is arranged in the second L gap 19.

[0041] (External Electrodes) The external electrodes include a first external electrode 41 and a second external electrode 42. The first external electrode 41 is connected to the first internal electrode 31 and is disposed on the first end face 7. The first external electrode 41 may also be disposed on a portion of the first main surface 3 and a portion of the second main surface 4, as well as a portion of the first side surface 5 and a portion of the second side surface 6. In this embodiment, the first external electrode 41 is disposed from the first end face 7 to a portion of the first main surface 3 and a portion of the second main surface 4, as well as a portion of the first side surface 5 and a portion of the second side surface 6.

[0042] The second external electrode 42 is connected to the second internal electrode 32 and is disposed on the second end face 8. The second external electrode 42 may also be disposed on a portion of the first main surface 3 and a portion of the second main surface 4, as well as a portion of the first side surface 5 and a portion of the second side surface 6. In this embodiment, the second external electrode 42 is disposed from the second end face 8 to a portion of the first main surface 3 and a portion of the second main surface 4, as well as a portion of the first side surface 5 and a portion of the second side surface 6.

[0043] The external electrodes include an underlying electrode layer and a plating layer.

[0044] (Base electrode layer) The base electrode layer will be described with reference to Fig. 2. The base electrode layer includes a first base electrode layer 51 and a second base electrode layer 52. The first base electrode layer 51 is a base electrode layer included in the first external electrode 41. The second base electrode layer 52 is a base electrode layer included in the second external electrode 42.

[0045] The base electrode layer includes at least one selected from a baked layer, a conductive resin layer, a thin film layer, etc. When the base electrode layer is a baked layer, the baked layer includes a glass component and a metal. The glass component includes at least one element selected from, for example, B, Si, Ba, Mg, Al, and Li. The metal includes at least one element selected from, for example, Cu, Ni, Ag, Pd, an Ag-Pd alloy, and Au.

[0046] The baking layer may be formed in multiple layers. The baking layer is formed by applying a conductive paste containing a glass component and a metal to the laminate and baking it. The baking layer may be simultaneously baked with the internal electrodes and the dielectric layers. Alternatively, the baking layer may be baked after the internal electrodes have been baked. When the baking layer is simultaneously baked with the internal electrodes and the dielectric layers, it is preferable to form the baking layer by adding a dielectric material instead of the glass component.

[0047] The thickness in the length direction L at the center position in the stacking direction T of the baked layer located on the first end face 7 and the second end face 8 is preferably, for example, about 3 μm or more and 160 μm or less.

[0048] When a baked layer is provided as a base electrode layer on a portion of the first main surface 3 and a portion of the second main surface 4, and also on a portion of the first side surface 5 and a portion of the second side surface 6, it is preferable that the thickness in the stacking direction T or the width direction W at the center in the length direction L of the base electrode layer located on the first main surface 3 and the second main surface 4, and the first side surface 5 and the second side surface 6 is, for example, approximately 3 μm or more and 40 μm or less.

[0049] (Plating Layer) The plating layer will be described. The plating layer includes a first plating layer and a second plating layer. The first plating layer is disposed so as to cover the first base electrode layer 51. The second plating layer is disposed so as to cover the second base electrode layer 52.

[0050] The material constituting the plating layer includes, for example, at least one selected from Cu, Ni, Sn, Ag, Pd, an Ag—Pd alloy, and Au.

[0051] The plating layer may be formed of multiple layers. In this embodiment, the first plating layer and the second plating layer each include two plating layers. When the plating layer has a two-layer structure, preferably, one plating layer is a Ni plating layer and the other plating layer is a Sn plating layer. The Ni plating layer included in the first plating layer is referred to as a first Ni plating layer 63. The Ni plating layer included in the second plating layer is referred to as a second Ni plating layer 64. The Sn plating layer included in the second plating layer is referred to as a first Sn plating layer 65. The Sn plating layer included in the second plating layer is referred to as a second Sn plating layer 66.

[0052] The Ni plating layer can prevent the base electrode layer from being eroded by solder when mounting the ceramic electronic component. The Sn plating layer improves the wettability of the solder when mounting the ceramic electronic component, allowing for easier mounting. The plating layers are preferably Ni plating layer and Sn plating layer, in that order, from the plating layer in contact with the base electrode layer. The plating layers may be three or more layers. The plating layers may be mainly composed of metal species other than Ni and Sn.

[0053] The preferred thickness of each plating layer is 2 μm or more and 15 μm or less.

[0054] (When no base electrode layer is provided) External electrodes may be formed using only plating layers without providing a base electrode layer. A structure in which only plating layers are provided without providing a base electrode layer will be described. No base electrode layer is provided on the first external electrode or the second external electrode, and the plating layer is formed directly on the surface of the laminate. The multilayer ceramic capacitor includes a plating layer that is directly and electrically connected to the first internal electrode or the second internal electrode. When the external electrodes have such a structure, a catalyst may be disposed on the surface of the laminate as a pretreatment for plating, and then the plating layer may be formed.

[0055] In this case, the plating layer preferably includes a lower-layer plating electrode formed on the surface of the laminate and an upper-layer plating electrode formed on the surface of the lower-layer plating electrode. The lower-layer plating electrode and the upper-layer plating electrode preferably include at least one metal selected from Cu, Ni, Sn, Pb, Au, Ag, Pd, Bi, and Zn, or an alloy containing such a metal. The lower-layer plating electrode is preferably formed using Ni, which has solder barrier properties. The upper-layer plating electrode is preferably formed using Sn or Au, which have good solder wettability.

[0056] When the first internal electrode and the second internal electrode are formed using Ni, it is preferable that the lower-layer plated electrode be formed using Cu, which has good bonding properties with Ni. The upper-layer plated electrode may be formed as needed. The first external electrode and the second external electrode may be composed of only the lower-layer plated electrode. The upper-layer plated electrode may be the outermost layer of the plated layer, or other plated electrodes may be formed on the surface of the upper-layer plated electrode.

[0057] The thickness of each plating layer disposed without a base electrode layer is preferably 1 μm or more and 15 μm or less. The plating layer preferably does not contain glass. The metal content per unit volume of the plating layer is preferably 99% by volume or more.

[0058] (Size of Multilayer Ceramic Capacitor) When the size of the multilayer ceramic capacitor 1 including the laminate 2 and the external electrodes is expressed as "length in the longitudinal direction (L) × length in the width direction (W) × length in the stacking direction (T)", it is generally expected to be, for example, "1.6 mm × 0.8 mm × 0.8 mm", "1.0 mm × 0.5 mm × 0.5 mm", "0.6 mm × 0.3 mm × 0.3 mm", "0.4 mm × 0.2 mm × 0.2 mm", or "0.2 mm × 0.1 mm × 0.1 mm". However, the size of the multilayer ceramic capacitor 1 is not limited to the above sizes.

[0059] The thickness of the first outer layer portion 11 and the thickness of the second outer layer portion 12 can be set to, for example, 10 μm or more and 80 μm or less.

[0060] (Width Direction Ends of Internal Electrodes) The positions of each part of the internal electrodes and the distances between each part will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view taken along line 2004-2004 in Fig. 1. Fig. 5 shows a cross-section of the laminate 2 in the width direction W and stacking direction T at the center of the longitudinal direction L of the laminate 2.

[0061] 5, the internal electrodes are designated as internal electrodes 301, 302, ..., and 30n in order from the internal electrode closest to the first main surface 3 to the internal electrode closest to the second main surface 4. In the following explanation, the internal electrodes 301 and 302 are taken as examples. The following explanation also applies to the other internal electrodes subsequent to the internal electrode 302, such as the internal electrodes 303 and 304.

[0062] The end of the internal electrode 301 in the width direction W on the first side surface 5 side is referred to as the width direction end 101. The same applies to the internal electrode 302, etc., subsequent to the internal electrode 301. The end of the internal electrode 30n in the width direction W on the first side surface 5 side is referred to as the width direction end 10n.

[0063] (End-to-end distance) The distance between widthwise end 101 and widthwise end 102 is defined as end-to-end distance 111. Similarly, the distance between widthwise end 102 and widthwise end 103 is defined as end-to-end distance 112. Hereinafter, the same applies to the distance between widthwise end 103 and widthwise end 104, etc.

[0064] (Width Direction Center) A line 501 in Fig. 5 indicates the center of the inner layer section 10 in the width direction W. The line 501 is referred to as the width direction center line 501. The width direction center line 501 indicates the width direction center of the inner layer section 10.

[0065] (Inter-electrode distance) The distance between the internal electrodes 302 at the center in the width direction is referred to as inter-electrode distance 211. The distance between the internal electrodes 302 and 303 at the center in the width direction is referred to as inter-electrode distance 212. Hereinafter, the same applies to the distance between the internal electrodes 303 and 304, etc.

[0066] In the multilayer ceramic capacitor 1 of this embodiment, in a cross section in the width direction W and the stacking direction T, the distance between width direction ends of internal electrodes adjacent in the stacking direction T is greater than the inter-electrode distance of the same internal electrodes adjacent in the stacking direction T. For example, the inter-electrode distance 111 is greater than the inter-electrode distance 211. Similarly, the inter-electrode distance 112 is greater than the inter-electrode distance 212.

[0067] The fact that the distance between the ends of adjacent internal electrodes in the stacking direction T is greater than the distance between the electrodes means that the shape of the internal electrodes is such that the distance between the ends in the width direction W of the internal electrodes widens toward the side. By shaping the internal electrodes as described above, the thickness of the dielectric layer 20 between the internal electrodes can be made greater at the width direction ends than at the width direction center. In other words, the thickness of the dielectric layer 20 can be made greater as it approaches the width direction ends from the width direction center. This can further improve the withstand voltage at the width direction ends.

[0068] (First virtual line) The first virtual line 511 will be described with reference to Fig. 6. Fig. 6 is a cross-sectional view taken along line 2004-2004 in Fig. 1, similar to Fig. 5. The first virtual line 511 is a line connecting the width direction ends of the internal electrodes. A method for determining the first virtual line 511 will be described.

[0069] (Width Direction End and Virtual End) Consider an XY Cartesian coordinate system in a cross section of the width direction W and stacking direction T shown in Fig. 6. The average of the XY coordinates of three width direction end points positioned consecutively in the stacking direction T is set as the XY coordinate of the virtual end point. In other words, the XY coordinate of the virtual end point is the average of the XY coordinates of the three consecutive width direction end points. The virtual end point is a virtual point determined by calculation, and is therefore not shown in Fig. 6.

[0070] For example, the point of the average XY coordinates of the XY coordinates of width direction end 101, the XY coordinates of width direction end 102, and the XY coordinates of width direction end 103 is defined as virtual end 201. Similarly, the point of the average XY coordinates of the XY coordinates of width direction end 102, the XY coordinates of width direction end 103, and the XY coordinates of width direction end 104 is defined as virtual end 202. In this way, the point of the average XY coordinates of the XY coordinates of width direction end 10n-2, width direction end 10n-1, and width direction end 10n is defined as virtual end 20n-2.

[0071] An approximation line from the determined imaginary end 201 to the imaginary end of imaginary end 20n-2 is determined. This approximation line is referred to as the first imaginary line 511. The approximation line may be expressed as a pseudo-continuous function of the imaginary end, and various methods of expression are available, such as a linear function, a quadratic function, an exponential function, a trigonometric function, or an inverse proportional function, using the least squares method or the like. Furthermore, the number of widthwise end portions averaged when determining the imaginary end portion is typically three as described above, but is not limited to three. From the viewpoint of obtaining an approximation line that is more in line with actual conditions, the imaginary end portion can also be obtained from the average of, for example, five widthwise end portions.

[0072] An example of how to determine the first virtual line 511 will be described in more detail. (Stacking Direction Center) Line 502 in Figure 6 is a line that indicates the center of the stacking direction T of the inner layer section 10. Line 502 is called the stacking direction center line 502. The stacking direction center line 502 indicates the center of the stacking direction of the inner layer section 10.

[0073] In a cross section of the laminate 2 in the width direction W and stacking direction T, an orthogonal coordinate system is established with the intersection of the stacking direction centerline 502 and the width direction centerline 501 as the origin O, the stacking direction centerline 502 as the X-axis, and the width direction centerline 501 as the Y-axis. Two-dimensional coordinates are given to the width direction ends of the internal electrodes to obtain two-dimensional coordinates of the virtual ends. The constants of a linear or quadratic function are found from multiple virtual ends using the least squares method. A first virtual line 511 is a line drawn by substituting the found constants into the linear or quadratic function. However, the range of the first virtual line 511 in the width direction W is limited to the coordinates in the width direction W at which the points of the width direction ends of the internal electrodes exist. In this embodiment, an approximation curve of a quadratic function is used as the first virtual line 511.

[0074] 6, the first imaginary line 511 is convex toward the widthwise center line 501. The vertex of the first imaginary line 511 is defined as a vertex 525.

[0075] The fact that the first virtual line 511 has the above-described convex shape means that the positions of the widthwise ends are shifted in the widthwise direction W in the stacking direction T. The shift in the positions of the widthwise ends shifts the areas where the electric field concentrates. As a result, it is possible to suppress a decrease in resistance value due to the electric field concentrating at the widthwise ends of the internal electrodes.

[0076] As described above, in the multilayer ceramic capacitor 1 of this embodiment, the first imaginary line 511 connecting the widthwise ends of the internal electrodes, where electric field concentration is likely to occur, is shifted in the lamination direction so as to be convex toward the widthwise center line 501. This makes it possible to efficiently suppress electric field concentration and increase the withstand voltage of the multilayer ceramic capacitor 1. As a result, the reliability of the multilayer ceramic capacitor 1 can be improved.

[0077] In the cross section of the multilayer ceramic capacitor 1 of this embodiment taken along the width direction W and the stacking direction T, the vertex 525 of the first imaginary line 511 is closest to the width direction center line 501 at the center of the stacking direction. As shown in FIG. 6 , the vertex 525 of the first imaginary line 511 is located on the stacking direction center line 502. By locating the vertex 525 at the center of the stacking direction in this manner, electric field concentration can be more efficiently suppressed. As a result, the withstand voltage of the multilayer ceramic capacitor 1 can be further increased.

[0078] 6, the end of the first imaginary line 511 on the first main surface 3 side is shown as an imaginary line end 521. The end of the first imaginary line 511 on the second main surface 4 side is shown as an imaginary line end 522.

[0079] (W (w edge)) The distance in the width direction W between the vertex 525 of the first virtual line 511 and the point on the first virtual line 511 that is farthest from the width-direction center line 501 is defined as W (w edge). In the example shown in FIG. 6 , of the virtual line end portions 521 and 522, the virtual line end portion 522 is defined as the point farthest from the width-direction center line 501. The line that passes through the virtual line end portion 522 and is parallel to the stacking direction T is defined as line 523. The line that passes through the vertex 525 and is parallel to the stacking direction T is defined as line 526. The distance between the line 526 and the line 523 is defined as distance 531. Distance 531 is W (w edge).

[0080] (T(w edge)) On the first virtual line 511, the distance between the farthest points in the stacking direction T is defined as T(w edge). In the example shown in FIG. 6, virtual line end 521 and virtual line end 522 are the farthest points in the stacking direction T. A line that passes through virtual line end 521 and is parallel to the width direction W is indicated by line 551. A line that passes through virtual line end 522 and is parallel to the width direction W is indicated by line 552. The distance between line 551 and line 552 is defined as distance 532. Distance 532 is T(w edge).

[0081] In the multilayer ceramic capacitor 1 of this embodiment, the value of W(w edge)×T(w edge) is not less than 50750 μm×μm and not more than 105000 μm×μm.

[0082] As described above, W (w edge) refers to the distance in the width direction W between the vertex 525 of the first imaginary line 511 and the point farthest from the widthwise center line 501 of the first imaginary line 511 at the center of the length direction L in the cross section in the width direction W and the stacking direction T. T (w edge) refers to the distance between the ends of the first imaginary line 511 in the stacking direction T. By setting the value of W (w edge) × T (w edge) to be 50,750 μm × μm or more and 105,000 μm × μm, electric field concentration can be more efficiently suppressed. As a result, the withstand voltage of the multilayer ceramic capacitor 1 can be further increased.

[0083] In Fig. 5, in a cross section in the width direction W and the stacking direction T, the width direction end of the internal electrode closest to the first side surface 5 is shown as width direction end 401. Also, the width direction end of the internal electrode farthest from the first side surface 5 is shown as width direction end 402. In the example shown in Fig. 5, the width direction end 401 is the width direction end 10n. Also, in the example shown in Fig. 5, the width direction end 402 is the width direction end 106. A distance 411 in Fig. 5 indicates the distance in the width direction W between the width direction end 401 and the width direction end 402. In other words, the distance 411 indicates the distance in the width direction W from the width direction end of the internal electrode closest to the side surface to the width direction end of the internal electrode farthest from the side surface.

[0084] 5 indicates the length in the width direction W of the laminate 2. In the multilayer ceramic capacitor 1 of this embodiment, by appropriately setting the distance 411 / distance 412, the minimum value of the breakdown voltage (BDV) can be increased.

[0085] (Bent Portion) The bent portion will be described with reference to Figure 7. Figure 7 is a cross-sectional view of the laminate 2 at the center in the width direction W, taken along a plane in the length direction L and stacking direction T. Figure 7 shows a portion of the laminate 2 near the first end face 7. Below, the internal electrodes and the like will be described using the vicinity of the first end face 7 as an example. The contents described below also apply to the vicinity of the second end face 8.

[0086] The bent portion is a portion formed in the lead portion of the internal electrode, where the internal electrode is bent in the stacking direction T. Fig. 7 shows a bent portion formed in the first lead portion 35. Fig. 7 illustrates four bent portions, namely, bent portion 601, bent portion 602, bent portion 603, and bent portion 604, in this order from the first main surface 3 to the second main surface 4.

[0087] (Shape of Bent Portion) Fig. 7 illustrates a bent portion having a V-shaped cross section. However, the shape of the bent portion is not limited to a V-shape. The cross-sectional shape of the bent portion is not particularly limited as long as it has a vertex, such as a U-shape.

[0088] (Bending Direction) The bent portions have a shape that is convex toward the stacking direction center line 502. In the example shown in Fig. 7 , bent portions 601, 602, 603, and 604 are all convex toward the stacking direction center line 502. Bent portions 601 and 602 located between the stacking direction center line 502 and the first main surface 3 in the stacking direction T are convex toward the second main surface 4. Bent portions 603 and 604 located between the stacking direction center line 502 and the second main surface 4 in the stacking direction T are convex toward the first main surface 3.

[0089] (Apex of bent portion) As described above, the bent portion has a shape with an apex. The apex of bent portion 601 is designated as apex 611. Similarly, for the other bent portions, the apex of bent portion 602 is designated as apex 612, the apex of bent portion 603 is designated as apex 613, and the apex of bent portion 604 is designated as apex 614.

[0090] (Second Virtual Line) In the cross section of the length direction L and the stacking direction T shown in FIG. 7 , the virtual line connecting the vertices of the bent portions is called the second virtual line 621. The method for determining the second virtual line 621 is the same as that for the first virtual line 511. XY coordinate axes are set on the cross section of the length direction L and the stacking direction T. The averages of the coordinates of the vertices of three bent portions adjacent in the stacking direction T are determined in sequence. "Determining in sequence" refers to determining the average of the vertex coordinates by shifting the combination of three adjacent bent portions in sequence in the stacking direction, as with the first virtual line 511. The point of the averaged coordinates is called the virtual vertex. For example, the point obtained by averaging the coordinates of vertices 611, 612, and 613 is defined as the first virtual vertex, and then the point obtained by averaging the coordinates of vertices 612, 613, and 614 is defined as the second virtual vertex. The virtual line connecting the virtual vertices determined in this manner in sequence is the second virtual line 621. The second virtual line 621 shown in FIG. 7 is a second-order approximation line.

[0091] 7 indicates the center of the inner layer section 10 in the length direction L. The line 503 is referred to as the lengthwise center line 503. The lengthwise center line 503 indicates the center of the inner layer section 10 in the lengthwise direction.

[0092] The second virtual line 621 is curved so as to be convex toward the longitudinal center line 503 in the cross section in the longitudinal direction L and the stacking direction T. This indicates that the bent portions of the internal electrodes are misaligned in the stacking direction T. The misalignment of the bent portions of the internal electrodes in the stacking direction T causes the locations where the electric field concentrates to be misaligned. As a result, the electric field concentration can be suppressed, and the decrease in resistance value due to the electric field concentration can be suppressed.

[0093] The apex of the convex portion of the second virtual line 621 is indicated by a point 631. As shown in FIG. 7 , the apex 631 of the convex portion is located on the center line 502 in the stacking direction. In other words, the apex 631 of the convex portion is located at the center in the stacking direction. This makes it possible to more uniformly suppress electric field concentration in the stacking direction T. As a result, it is possible to more reliably suppress a decrease in resistance value due to electric field concentration.

[0094] (Height of bent portion) The difference between the position of the internal electrode at the center in the longitudinal direction in the stacking direction T and the position of the apex of the bent portion of the internal electrode in the stacking direction T is called the height of the bent portion. In Fig. 7, the height of the bent portion 603 of the internal electrode 308 is indicated by height 641. Furthermore, the height of the bent portion 604 of the internal electrode 310 is indicated by height 642. The height 642 is longer than the height 641. In other words, the height of the bent portion of the internal electrode closer to the main surface is higher than the height of the bent portion of the internal electrode closer to the center in the stacking direction.

[0095] 7, the distance between the exposed positions of the internal electrodes 302 and 304 on the first end face 7 is indicated by distance 652. The distance in the stacking direction T between the internal electrodes 302 and 304 at the center in the longitudinal direction is indicated by distance 651. Distance 652 is longer than distance 651.

[0096] In this embodiment, the distance in the stacking direction T between adjacent internal electrodes at the end faces can be made longer than the distance at the center in the longitudinal direction, which makes it easier to suppress a decrease in resistance value due to electric field concentration.

[0097] The distance in the stacking direction T between the internal electrodes adjacent to each other at the end surface can be increased from the center in the stacking direction T toward the main surface. For example, with respect to distance 652 and distance 653 shown in FIG. 7 , distance 652 can be made greater than distance 653.

[0098] This makes it easier to suppress electric field concentration in the vicinity of the main surface where electric field concentration is likely to occur.

[0099] 7 indicates the distance in the stacking direction T between adjacent internal electrodes at the center in the longitudinal direction. Distance 661 indicates the distance between internal electrode 304 and internal electrode 305. However, the distance between other internal electrodes is also the same as distance 661.

[0100] For internal electrodes exposed at the end surfaces, the distance between adjacent internal electrodes in the stacking direction T at the end surfaces is, for example, distance 652 and distance 653. Distances 652 and 653 are greater than twice distance 661. Specifically, when T1 is the distance in the stacking direction T between the first internal electrode 31 and the second internal electrode 32 at the center of the longitudinal direction L of the laminate 2, and T2 is the distance in the stacking direction T between adjacent first lead portions 35 at the first end surface 7, the relationship between T1 and T2 satisfies T2 > 2 × T1. This is because the thickness of the dielectric layer 20 is thicker near the lead-portion-side end of the opposing portion. Furthermore, this configuration eliminates the step between the electrode opposing portion 38 and the first L gap 18 and the step between the electrode opposing portion 38 and the second L gap 19, thereby suppressing the occurrence of structural defects.

[0101] (Shape of Laminate) The shape of the element, i.e., the laminate 2, will now be described. In the multilayer ceramic capacitor 1 of this embodiment, the ends of the laminate 2 in the width direction W are raised. As explained above, distance 442 shown in FIG. 5 indicates the length of the laminate 2 in the stacking direction T at the ends of the laminate 2 in the width direction W. Distance 445 in FIG. 5 indicates the length of the laminate 2 in the stacking direction T at the center of the laminate 2 in the width direction. Distance 442 is greater than distance 445. In other words, the ends of the laminate 2 in the width direction W are raised. Conversely, the center of the laminate 2 in the width direction is recessed.

[0102] Furthermore, in the multilayer ceramic capacitor 1 of this embodiment, the ends of the laminate 2 in the length direction L are raised. Distance 661 shown in Fig. 7 indicates the length of the laminate 2 in the stacking direction T at the ends of the laminate 2 in the length direction L. Distance 662 in Fig. 7 indicates the dimension of the laminate 2 in the stacking direction T at the center of the laminate 2 in the length direction. Distance 661 is greater than distance 662. In other words, the ends of the laminate 2 in the length direction L are raised. Conversely, the center of the laminate 2 in the length direction is recessed.

[0103] 7 is a line connecting the boundary between the first opposing portion 33 and the first lead portion 35 of the first internal electrode 31. Like the second imaginary line 621, the line 641 also has a convex shape toward the longitudinal center line 503.

[0104] In the multilayer ceramic capacitor 1 of this embodiment, bent portions are arranged in the internal electrodes, and the internal electrodes are not straight in cross sections in the length direction L and the stacking direction T. As a result, electric field concentration near the end faces can be suppressed.

[0105] A modified example of the multilayer ceramic capacitor 1 will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view of a multilayer ceramic capacitor 1 taken along the width direction W and lamination direction T, showing a modified example of the embodiment of the present invention. Unlike the multilayer ceramic capacitor 1 described above, the modified multilayer ceramic capacitor 1 has end bends arranged at the width direction ends of the internal electrodes.

[0106] (Bent end portion) The bent end portion refers to a part of the internal electrode that is arranged in a width direction end region of the internal electrode and is bent in the stacking direction T in a cross section of the width direction W and the stacking direction T. The width direction end region refers to a region within a range of 15 μm in the width direction W from the width direction end of the internal electrode toward the width direction center line 501 of the inner layer portion 10. In the multilayer ceramic capacitor 1 of the modified example, at least some of the internal electrodes have bent end portions.

[0107] 8 illustrates four end bends: end bend 701, end bend 702, end bend 703, and end bend 704. End bend 701 is an end bend provided on internal electrode 302. End bend 702 is an end bend provided on internal electrode 309, end bend 703 is an end bend provided on internal electrode 303, and end bend 704 is an end bend provided on internal electrode 307. Note that end bends 701 to 704 are merely examples, and the number of end bends and the internal electrodes on which they are arranged are not particularly limited.

[0108] 8 illustrates a width direction end region 720 of the internal electrode 302 as an example of the width direction end region. The length 721 is 15 μm. The width direction end region 720 extends 15 μm from the width direction end 102 of the internal electrode 302 toward the width direction center line 501. The same applies to the other internal electrodes.

[0109] The end bends have vertices. The vertex of end bend 701 is indicated by vertex 711. The vertex of end bend 702 is indicated by vertex 712, the vertex of end bend 703 by vertex 713, and the vertex of end bend 704 by vertex 714. The vertices of the end bends preferably face in the direction of stacking direction center line 502. In other words, the end bends preferably have a convex shape facing stacking direction center line 502. This makes it easier to suppress electric field concentration.

[0110] Even when an end bend is disposed in the internal electrode, the first virtual line 511 can be determined by the same method as described above. As described above, the first virtual line 511 is determined based on the X and Y coordinates of the virtual end. The X and Y coordinates of the virtual end are determined as the average of the X and Y coordinates of three widthwise ends that are consecutively positioned in the stacking direction T. Therefore, even when an end bend is disposed in the internal electrode and the widthwise end of the internal electrode is located far away from the widthwise ends of the other internal electrodes, that is, even when the widthwise end of the internal electrode is located in a unique position relative to the widthwise ends of the other internal electrodes, it is easy to obtain a first virtual line 511 that reflects the actual situation.

[0111] Another modified example of the multilayer ceramic capacitor 1 will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view of a multilayer ceramic capacitor 1 showing another modified example of the embodiment of the present invention, taken along a plane in the width direction W and lamination direction T. The multilayer ceramic capacitor 1 of the modified example shown in Fig. 9 differs from the multilayer ceramic capacitor 1 described above in that the first imaginary line is a straight line.

[0112] The first imaginary line of the multilayer ceramic capacitor 1 of the modified example is referred to as a first imaginary line 512. The first imaginary line 512 is a straight line extending from a position corresponding to the widthwise end closest to the first main surface 3 to a position corresponding to the widthwise end at the center in the lamination direction. In the example shown in FIG. 9 , the widthwise end closest to the first main surface 3 is the widthwise end 101. The widthwise end at the center in the lamination direction is the widthwise end 106. The first imaginary line 512 is a straight line extending from a position corresponding to the widthwise end 101 to a position corresponding to the widthwise end 106.

[0113] The first virtual line 512 is a straight line from a position corresponding to the width direction end closest to the second main surface 4 to a position corresponding to the width direction end at the center in the stacking direction. In the example shown in Fig. 9 , the width direction end closest to the second main surface 4 is the width direction end 10n. The first virtual line 512 is a straight line from a position corresponding to the width direction end 10n to a position corresponding to the width direction end 106.

[0114] The first virtual line 512 has a vertex in a cross section in the width direction W and the stacking direction T. In Fig. 9, the vertex of the first virtual line 512 is shown as a vertex 527. The vertex 527 has a V-shape. Like the first virtual line 511, the first virtual line 512 has a convex shape toward the width direction center line 501.

[0115] The convex shape of the first virtual line 512 is symmetrical with respect to the stacking direction center line 502. In the example shown in Fig. 9, the vertex 527 is located on the stacking direction center line 502 and is convex toward the width direction center line 501.

[0116] (Method for Manufacturing Multilayer Ceramic Capacitor) A method for manufacturing the multilayer ceramic capacitor 1 will be described. Note that the method for manufacturing the multilayer ceramic capacitor 1 is not limited to the method described below.

[0117] A dielectric sheet and a conductive paste for the internal electrodes are prepared. The dielectric sheet and the conductive paste for the internal electrodes contain a binder and a solvent. Known binders and solvents can be used. The dielectric sheet is also called a ceramic green sheet. The conductive paste is also called an internal electrode paste.

[0118] A dielectric sheet on which an internal electrode pattern is formed is prepared, and a conductive paste for the internal electrodes is printed in a predetermined pattern on the dielectric sheet by, for example, screen printing or gravure printing, to form a dielectric sheet on which a pattern of a first internal electrode is formed and a dielectric sheet on which a pattern of a second internal electrode is formed.

[0119] A predetermined number of dielectric sheets not printed with an internal electrode pattern are stacked to form a portion that will become a first outer layer portion, on which dielectric sheets printed with a first internal electrode pattern and a second internal electrode pattern are stacked in order to form a portion that will become an inner layer portion, and further a predetermined number of dielectric sheets not printed with an internal electrode pattern are stacked on top of the portion that will become an inner layer portion to form a portion that will become a second outer layer portion, thereby producing a laminated sheet.

[0120] (Step Absorbing Layer Paste) In the multilayer ceramic capacitor 1 of this embodiment, the step absorbing layer paste is printed on the ceramic green sheets on which the internal electrode paste has been printed. That is, the manufacturing process includes a step absorbing layer paste printing process following the internal electrode printing process. When printing the step absorbing layer paste on the ceramic green sheets, the step absorbing layer paste is printed thicker than the internal electrode paste and so as not to overlap with the internal electrode paste. Note that the printing order of the internal electrode paste and the step absorbing layer paste is not limited to the above example. For example, the internal electrode paste may be printed after the step absorbing layer paste.

[0121] The description will be made with reference to Fig. 10. Fig. 10 is a diagram showing a state in which an internal electrode paste 1001, an internal electrode paste 1002, and a step absorption layer paste 1003 are printed on a ceramic green sheet 1000. The internal electrode paste 1001 and the internal electrode paste 1002 are made of the same material. The internal electrode paste 1001 is printed in a pattern corresponding to the first internal electrode. The internal electrode paste 1002 is printed in a pattern corresponding to the second internal electrode.

[0122] As shown in FIG. 10 , the step absorption layer paste 1003 is printed so as not to overlap the internal electrode paste 1001. Similarly, the step absorption layer paste 1003 is printed so as not to overlap the internal electrode paste 1002. When viewed in a plan view along the lamination direction T, a gap is provided between the step absorption layer paste 1003 and the internal electrode paste 1001. Similarly, a gap is provided between the step absorption layer paste 1003 and the internal electrode paste 1002. The gap between the step absorption layer paste 1003 and the internal electrode paste 1001 is indicated by gap 1021. The gap between the step absorption layer paste 1003 and the internal electrode paste 1002 is also the same as gap 1021. The gap 1021 can be preferably set to be 20 μm or more and 100 μm or less.

[0123] Furthermore, the step absorption layer paste 1003 is printed thicker than the internal electrode paste 1001. In FIG. 10 , the thickness of the internal electrode paste 1001 is indicated by thickness 1010. The thickness of the internal electrode paste 1002 is also the same as thickness 1010. The thickness of the step absorption layer paste 1003 is indicated by thickness 1011. Thickness 1011 is thicker than thickness 1010. It is preferable that thickness 1011 be 1.1 times or more and 1.3 times or less than thickness 1010. The thickness 1011 of the step absorption layer paste 1003 can be, for example, 0.75 μm or more and 0.95 μm or less.

[0124] The step absorption layer paste 1003 may have the same material composition as the dielectric layer paste that constitutes the ceramic green sheets, that is, the dielectric sheets, or may have a different material composition.

[0125] In this embodiment, the thickness of the step absorption layer paste and the distance between the step absorption layer paste and the internal electrode paste are adjusted so that the widthwise ends of each internal electrode after the firing process are positioned in a position resembling a parabola, thereby making it possible to manufacture the desired multilayer ceramic capacitor.

[0126] Furthermore, the multilayer ceramic capacitor 1 of the modified example described with reference to FIG. 9 can also be manufactured by appropriately changing the thickness of the step absorption layer paste and the distance between the step absorption layer paste and the internal electrode paste so that the widthwise ends of each internal electrode after the firing process are positioned in a position similar to a straight line.

[0127] The laminated sheets are pressed in the lamination direction by means of a hydrostatic press or the like to produce a laminated block.

[0128] The laminated block is cut into individual pieces to produce laminated chips. Specifically, the laminated block is cut into individual pieces using a cutting blade to produce pre-fired laminates.

[0129] The laminated chips are fired to produce a laminate. Before firing, the corners and ridges of the laminated chips may be rounded by barrel polishing or the like. The firing temperature is preferably 900°C or higher and 1400°C or lower, although this depends on the materials of the dielectric and internal electrodes.

[0130] Next, the external electrodes are formed. First, a conductive paste that will become the base electrode layer is applied to both end surfaces of the laminate 2 to form the base electrode layer. When forming a baked layer as the base electrode layer, a conductive paste containing a glass component and a metal is applied by a method such as dipping, and then a baking process is performed to form the base electrode layer. The baking temperature at this time is preferably 700°C or higher and 900°C or lower.

[0131] Thereafter, a plating layer is formed on the surface of the base electrode layer. A Ni plating layer and a Sn plating layer are formed on the base electrode layer. The Ni plating layer and the Sn plating layer are formed sequentially by, for example, barrel plating. In this manner, a multilayer ceramic capacitor is obtained.

[0132] 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, modifications, and combinations are possible.

[0133] <1> A multilayer ceramic capacitor comprising: a laminate including a plurality of laminated dielectric layers and a plurality of internal electrodes, the laminate having first and second main surfaces facing each other in a stacking direction of the dielectric layers and the internal electrodes, first side surfaces facing each other in a width direction perpendicular to the stacking direction, and first end surfaces facing each other in a length direction perpendicular to the stacking direction and the width direction; and external electrodes electrically connected to the internal electrodes and provided on a surface of the laminate, wherein the laminate has an inner layer portion in which the dielectric layers and the internal electrodes are alternately stacked, and in a cross section in the width direction and the stacking direction, the distance between the width direction ends of the internal electrodes adjacent to each other in the stacking direction is greater than the distance at the width direction centers of the inner layer portions of the internal electrodes adjacent to each other in the stacking direction, and a first imaginary line connecting the width direction ends of the internal electrodes is convex toward the width direction center of the inner layer portion.

[0134] <2> The multilayer ceramic capacitor according to <1>, wherein, in a cross section in the width direction and the stacking direction, the vertex of the first virtual line is closest to the center of the inner layer portion in the width direction at the center of the inner layer portion in the stacking direction.

[0135] <3> The multilayer ceramic capacitor according to <1> or <2>, wherein, in a cross section in the width direction and the stacking direction, a value of W(w edge)×T(w edge) is 50750 μm×μm or more and 105000 μm×μm or less, where W(w edge) is a distance in the width direction between an apex of the first imaginary line and a point on the first imaginary line farthest from a center in the width direction of the inner layer portion, and T(w edge) is a distance between end portions of the first imaginary line in the stacking direction.

[0136] <4> The multilayer ceramic capacitor according to any one of <1> to <3>, wherein the internal electrodes include a first internal electrode extended to the first end surface and a second internal electrode extended to the second end surface, the first internal electrode includes a first opposing portion facing the second internal electrode in the stacking direction and a first extended portion not facing the second internal electrode in the stacking direction, the second internal electrode includes a second opposing portion facing the first internal electrode in the stacking direction and a second extended portion not facing the first internal electrode in the stacking direction, and in cross sections in the length direction and the stacking direction, the first extended portion and the second extended portion have bent portions where the internal electrodes are bent.

[0137] <5> The multilayer ceramic capacitor according to <4>, wherein the bent portion has a shape that is convex toward the center of the inner layer portion in the stacking direction, and in a cross section in the length direction and the stacking direction, a second imaginary line connecting vertices of the bent portion is curved so as to be convex toward the center of the inner layer portion in the length direction.

[0138] <6> The multilayer ceramic capacitor according to any one of <1> to <5>, wherein, in a cross section in the width direction and the stacking direction, at least one of the plurality of internal electrodes has an end bent portion having an apex, and the end bent portion is arranged in an end region in the width direction of the internal electrode.

[0139] <7> The multilayer ceramic capacitor according to any one of <1> to <6>, wherein the first imaginary line is determined based on imaginary edges defined based on a plurality of width direction edges of the internal electrodes.

[0140] <8> The multilayer ceramic capacitor according to any one of <1> to <7>, wherein the internal electrodes include a first internal electrode extended to the first end surface and a second internal electrode extended to the second end surface, and wherein, when a distance in the stacking direction between the first internal electrode and the second internal electrode at a center part in the length direction of the laminate is T1 and a distance in the stacking direction between adjacent first extended portions on the first end surface is T2, a relationship between T1 and T2 satisfies T2>2×T1.

[0141] REFERENCE SIGNS LIST 1 Multilayer ceramic capacitor 2 Laminate 3 First main surface 4 Second main surface 5 First side surface 6 Second side surface 7 First end surface 8 Second end surface 10 Inner layer portion 11 First outer layer portion 12 Second outer layer portion 15 First side gap portion 16 Second side gap portion 20 Dielectric layer 25 Core portion 26 Effective portion 28 First ineffective portion 29 Second ineffective portion 31 First internal electrode 32 Second internal electrode 33 First opposing portion 34 Second opposing portion 35 First lead portion 36 Second lead portion 38 Electrode opposing portion 41 First external electrode 42 Second external electrode 51 First base electrode layer 52 Second base electrode layer 501 Width direction center line 502 Stacking direction center line 503 Length direction center line 511 First virtual line 512 First virtual line 621 Second virtual line 720 Width direction end region

Claims

1. A multilayer ceramic capacitor comprising: a laminate including a plurality of laminated dielectric layers and a plurality of internal electrodes, the laminate having first and second main surfaces facing each other in a lamination direction of the dielectric layers and the internal electrodes, first and second side surfaces facing each other in a width direction perpendicular to the lamination direction, and first and second end faces facing each other in a length direction perpendicular to the lamination direction and the width direction; and external electrodes electrically connected to the internal electrodes and provided on a surface of the laminate, wherein the laminate has an inner layer portion in which the dielectric layers and the internal electrodes are alternately laminated, and in a cross section in the width direction and the lamination direction, the distance between the width direction ends of the internal electrodes adjacent to each other in the lamination direction is greater than the distance at the width direction centers of the inner layer portions of the internal electrodes adjacent to each other in the lamination direction, and a first imaginary line connecting the width direction ends of the internal electrodes is convex toward the width direction center of the inner layer portion.

2. The multilayer ceramic capacitor according to claim 1, wherein, in a cross section in the width direction and the stacking direction, the vertex of the first imaginary line is closest to the center of the inner layer portion in the width direction at the center of the inner layer portion in the stacking direction.

3. The multilayer ceramic capacitor according to claim 1 or 2, wherein, in a cross section in the width direction and the stacking direction, the value of W(w edge)×T(w edge) is 50750 μm×μm or more and 105000 μm×μm or less, where W(w edge) is the distance in the width direction between the vertex of the first imaginary line and the point of the first imaginary line farthest from the center in the width direction of the inner layer portion, and T(w edge) is the distance between the ends of the first imaginary line in the stacking direction.

4. The multilayer ceramic capacitor according to any one of claims 1 to 3, wherein the internal electrodes include a first internal electrode extended to the first end face and a second internal electrode extended to the second end face, the first internal electrode having a first opposing portion opposing the second internal electrode in the stacking direction and a first extended portion not opposing the second internal electrode in the stacking direction, the second internal electrode having a second opposing portion opposing the first internal electrode in the stacking direction and a second extended portion not opposing the first internal electrode in the stacking direction, and in cross sections in the length direction and the stacking direction, the first extended portion and the second extended portion have bent portions where the internal electrodes are bent.

5. The multilayer ceramic capacitor according to claim 4, wherein the bent portion has a shape that is convex toward the center of the inner layer portion in the stacking direction, and in a cross section in the longitudinal direction and the stacking direction, a second imaginary line connecting the vertices of the bent portion is curved so as to be convex toward the center of the inner layer portion in the longitudinal direction.

6. The multilayer ceramic capacitor according to any one of claims 1 to 5, wherein, on a surface in the width direction and the stacking direction, at least one of the plurality of internal electrodes has an end bent portion having an apex, and the end bent portion is arranged in an end region in the width direction of the internal electrode.

7. The multilayer ceramic capacitor according to claim 1, wherein the first imaginary line is determined based on imaginary edges defined based on the width direction edges of a plurality of the internal electrodes.

8. A multilayer ceramic capacitor according to any one of claims 1 to 7, wherein the internal electrodes include a first internal electrode extended to the first end face and a second internal electrode extended to the second end face, and wherein, when T1 is the distance in the stacking direction between the first internal electrode and the second internal electrode at the center in the longitudinal direction of the laminate and T2 is the distance in the stacking direction between adjacent first extended portions on the first end face, the relationship between T1 and T2 satisfies T2 > 2 × T1.

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