Multilayer ceramic capacitor

Abstract

Provided is a multilayer ceramic capacitor capable of more reliably suppressing the formation of blisters. A multilayer ceramic capacitor 1 comprising: a ceramic body 2 including a plurality of laminated dielectric layers and a plurality of laminated internal electrode layers, and having six faces consisting of a first main face 3 and a second main face 4 facing each other in a height direction T, a first side face 5 and a second side face 6 facing each other in a width direction W perpendicular to the height direction T, and a first end face 7 and a second end face 8 facing each other in a length direction L perpendicular to the height direction T and the width direction W; and external electrodes 22 provided on the ceramic body 2 and connected to some of the internal electrode layers, wherein when the portion on the face of the ceramic body 2 where an external electrode 22 is arranged is defined as an electrode arrangement portion 77, and the portion of the ceramic body 2 where two of the faces intersect is defined as a corner portion 78, the external electrode 22 includes glass domains 40, the ratio of the sum of the lengths, in the longitudinal direction L, of the glass domains 40 to the sum of the lengths, in the longitudinal direction L, of the surface of the electrode arrangement portion 77 of the ceramic body 2 on at least one face among the first side face 5, second side face 6, first main face 3, and second main face 4, and of the surface of the corner portion 78 of the ceramic body 2 contiguous with said surface of the electrode arrangement portion 77 in the longitudinal direction L is 40-60%, and the ratio of the number of glass domains 40 extending from the surface of the ceramic body 2 to the surface of the external electrode 22 among the glass domains 40 located in the electrode arrangement portion 77 is 10-30%.

Description

Multilayer ceramic capacitors

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

[0002] During the process of forming the external electrodes of a multilayer ceramic capacitor, blisters may form in the external electrodes. Blisters are cavities formed inside the external electrodes. The formation of blisters in the external electrodes may cause problems such as reduced conductivity or reduced reliability of the external electrodes. Patent Document 1 describes a method for reducing blisters by adjusting the material composition of the external electrodes.

[0003] Japanese Patent Application Publication No. 04-95307

[0004] However, conventional techniques have not been able to sufficiently prevent the occurrence of blisters. Therefore, an object of the present invention is to provide a multilayer ceramic capacitor that can more reliably prevent the occurrence of blisters.

[0005] The multilayer ceramic capacitor of the present invention is a multilayer ceramic capacitor comprising: a ceramic body including a plurality of laminated dielectric layers and a plurality of laminated internal electrode layers, the ceramic body having six surfaces: a first main surface and a second main surface opposing each other in a height direction; a first side surface and a second side surface opposing each other in a width direction perpendicular to the height direction; and a first end surface and a second end surface opposing each other in a length direction perpendicular to the height direction and the width direction; and external electrodes provided on the ceramic body and connected to some of the internal electrode layers, wherein the portions of the surfaces of the ceramic body where the external electrodes are arranged are electrode arrangement portions, and two of the surfaces of the ceramic body are arranged on the same surface. When a portion where the above surfaces intersect is defined as a corner portion, the external electrode includes a glass domain, and the ratio of the sum of the longitudinal lengths of the glass domains to the sum of the longitudinal lengths of the surface of the ceramic body in the electrode arrangement portion on at least one of the first side surface, the second side surface, the first main surface, and the second main surface and the surface of the ceramic body in the corner portion that is continuous with the surface in the longitudinal direction is 40% or more and 60% or less, and the ratio of the number of glass domains arranged in the electrode arrangement portion that extend from the surface of the ceramic body to the surface of the external electrode is 10% or more and 30% or less.

[0006] According to the present invention, it is possible to provide a multilayer ceramic capacitor that can more reliably suppress the occurrence of blisters.

[0007] 1 is a perspective view of a multilayer ceramic capacitor according to an embodiment of the present invention; 2 is a cross-sectional view taken along line II in FIG. 1; 3 is a cross-sectional view taken along line II-II in FIG. 1; 4 is an enlarged view of the framed portion in FIG. 2; 5 is an LT cross-sectional view showing the arrangement of glass domains; 6 is an LT cross-sectional view showing the conductive paste after application and drying; 7 is an LT cross-sectional view showing the conductive paste after baking; and 8 is a three-dimensional focused ion beam scanning electron microscope image of an external electrode.

[0008] An embodiment of the present invention will be described with reference to FIG. 1. FIG. 1 is a perspective view of a multilayer ceramic capacitor 1 according to an embodiment of the present invention. FIG. 1 shows a so-called two-terminal multilayer ceramic capacitor. The multilayer ceramic capacitor 1 of the present invention is not limited to a two-terminal multilayer ceramic capacitor. The multilayer ceramic capacitor 1 of the present invention may also be a multi-terminal multilayer ceramic capacitor, such as a three-terminal multilayer ceramic capacitor.

[0009] The multilayer ceramic capacitor 1 includes a ceramic body 2 and terminal electrodes. The terminal electrodes include a first terminal electrode 20 and a second terminal electrode 21.

[0010] The ceramic body 2 includes a plurality of laminated dielectric layers and a plurality of internal electrode layers, and is shaped like a rectangular parallelepiped.

[0011] In the ceramic body 2, the direction in which the dielectric layers and internal electrode layers are stacked is defined as a height direction T. The direction perpendicular to the height direction T is defined as a width direction W. The direction perpendicular to the height direction T and the width direction W is defined as a length direction L.

[0012] Of the two surfaces of the ceramic body 2 that face each other in the height direction T, one surface is designated as a first main surface 3. The remaining surface is designated as a second main surface 4. Of the two surfaces of the ceramic body 2 that face each other in the width direction W, one surface is designated as a first side surface 5. The remaining surface is designated as a second side surface 6. Of the two surfaces of the ceramic body 2 that face each other in the length direction L, one surface is designated as a first end surface 7. The remaining surface is designated as a second end surface 8.

[0013] 1 is referred to as an LT cross section, and the cross section of the ceramic body 2 taken along line II in FIG. 1 is referred to as a WT cross section.

[0014] The intersection of three faces of the ceramic body 2 is called a corner of the ceramic body 2. The intersection of two faces of the ceramic body 2 is called a ridge or corner of the ceramic body 2. The corners and ridges are preferably rounded.

[0015] The total number of dielectric layers stacked on the ceramic body 2 is preferably 15 or more and 2000 or less. The main material of the dielectric layers is a ceramic material. Examples of ceramic materials include dielectric ceramics containing barium titanate, calcium titanate, strontium titanate, calcium zirconate, or the like as main components. The ceramic material may also be a dielectric ceramic containing these main components plus a secondary component such as a manganese compound, an iron compound, a chromium compound, a cobalt compound, or a nickel compound.

[0016] The thickness of each dielectric layer is preferably 0.3 μm or more and 10 μm or less.

[0017] The division of the ceramic body 2 in the length direction L will be described with reference to Figure 2. Figure 2 is a cross-sectional view taken along line II in Figure 1. The ceramic body 2 can be divided into a first main surface side outer layer portion 10, an effective portion 11, and a second main surface side outer layer portion 12 in the height direction T.

[0018] The first main surface side outer layer portion 10 is the portion between the first main surface 3 and the internal electrode layer closest to the first main surface 3. The effective portion 11 is the portion where the internal electrode layers face each other. The second main surface side outer layer portion 12 is the portion between the second main surface 4 and the internal electrode layer closest to the second main surface 4.

[0019] Of the dielectric layers, the dielectric layers arranged in the first main surface side outer layer portion 10 and the second main surface side outer layer portion 12 are referred to as outer dielectric layers 30. Of the dielectric layers, the dielectric layer arranged in the effective portion 11 is referred to as inner dielectric layers 31.

[0020] The size of the ceramic body 2 is not particularly limited. The length in the longitudinal direction L of the ceramic body is preferably 0.2 mm or more and 10 mm or less. The length in the width direction W of the ceramic body 2 is preferably 0.1 mm or more and 5 mm or less. The length in the height direction T of the ceramic body 2 is preferably 0.1 mm or more and 5 mm or less.

[0021] The division of the ceramic body 2 in the longitudinal direction L will be described. The ceramic body 2 can be divided into a first end face side outer layer portion 13, a longitudinally facing portion 14, and a second end face side outer layer portion 15 in the longitudinal direction L.

[0022] The longitudinal facing portion 14 is a portion where internal electrode layers face each other in the height direction T. The first end face side outer layer portion 13 is a portion between the longitudinal facing portion 14 and the first end face 7. The second end face side outer layer portion 15 is a portion between the longitudinal facing portion 14 and the second end face 8.

[0023] The longitudinally opposing portions 14 correspond to opposing electrode portions of the internal electrode layers. The first end surface side outer layer portion 13 and the second end surface side outer layer portion 15 correspond to lead electrode portions of the internal electrode layers. The first end surface side outer layer portion 13 and the second end surface side outer layer portion 15 are also called L gaps.

[0024] The division of the ceramic body 2 in the width direction W will be described with reference to Figure 3. Figure 3 is a cross-sectional view taken along line II-II in Figure 1. The ceramic body 2 can be divided in the width direction W into a first side surface outer layer portion 16, a widthwise opposing portion 17, and a second side surface outer layer portion 18.

[0025] The widthwise facing portion 17 is a portion where internal electrode layers face each other in the height direction T. The first side surface side outer layer portion 16 is a portion between the widthwise facing portion 17 and the first side surface 5. The second side surface side outer layer portion 18 is a portion between the widthwise facing portion 17 and the second side surface 6.

[0026] The first side surface side outer layer portion 16 and the second side surface side outer layer portion 18 are portions where no internal electrode layers exist in the height direction T. The first side surface side outer layer portion 16 and the second side surface side outer layer portion 18 are also called W gaps.

[0027] The internal electrode layers include a plurality of first internal electrode layers 32 and a plurality of second internal electrode layers 33. The first internal electrode layers 32 are internal electrode layers exposed at the first end face 7. The second internal electrode layers 33 are internal electrode layers exposed at the second end face 8.

[0028] The first internal electrode layer 32 can be divided into a first opposing electrode portion 34 and a first lead electrode portion 36. The first opposing electrode portion 34 is a portion that faces the second internal electrode layer 33. The first lead electrode portion 36 is a portion that is led from the first opposing electrode portion 34 to the first end face 7 of the ceramic body 2.

[0029] The second internal electrode layer 33 can be divided into a second opposing electrode portion 35 and a second lead electrode portion 37. The second opposing electrode portion 35 is a portion that faces the first internal electrode layer 32. The second lead electrode portion 37 is a portion that is led from the second opposing electrode portion 35 to the second end face 8 of the ceramic body 2.

[0030] The material of the internal electrode layers can be, for example, a metal such as nickel, copper, silver, palladium, gold, etc. The material of the internal electrode layers can be an alloy containing at least one of the aforementioned metals, such as a silver-palladium alloy.

[0031] In the multilayer ceramic capacitor 1, capacitance is formed by the first opposing electrode portion 34 and the second opposing electrode portion 35 facing each other via the inner dielectric layer 31. This allows the multilayer ceramic capacitor 1 to exhibit capacitor characteristics.

[0032] The thickness of the internal electrode layer is preferably, for example, about 0.2 μm or more and 2.0 μm or less. The total number of the first internal electrode layers 32 and the second internal electrode layers 33 is preferably 15 or more and 2000 or less.

[0033] The terminal electrodes will now be described. The terminal electrodes include a first terminal electrode 20 and a second terminal electrode 21. The first terminal electrode 20 is a terminal electrode connected to a first internal electrode layer 32. The second terminal electrode 21 is a terminal electrode connected to a second internal electrode layer 33.

[0034] The first terminal electrode 20 is arranged on the first end face 7, part of the first main surface 3, part of the second main surface 4, part of the first side surface 5, and part of the second side surface 6. The second terminal electrode 21 is arranged on the second end face 8, part of the first main surface 3, part of the second main surface 4, part of the first side surface 5, and part of the second side surface 6.

[0035] The terminal electrodes include an external electrode 22, a nickel-plated film 24, and a tin-plated film 25. These are arranged in this order from the end face of the ceramic body 2: the external electrode 22, the nickel-plated film 24, and the tin-plated film 25.

[0036] The external electrodes 22 are disposed on and cover the end faces of the ceramic body 2. The external electrodes 22 extend from the end faces to parts of the main surfaces and parts of the side surfaces.

[0037] The external electrode 22 includes glass and metal. The glass includes at least one selected from boron, silicon, barium, magnesium, aluminum, lithium, etc. The metal includes at least one selected from copper, nickel, silver, palladium, a silver-palladium alloy, gold, etc. The external electrode 22 is formed by applying a conductive paste including glass and metal to the ceramic body 2 and firing the paste. The metal is contained in the conductive paste as metal powder. The glass is contained in the conductive paste as glass powder. The thickness of the external electrode 22 is preferably, for example, 3 μm or more and 25 μm or less. The external electrode 22 will be described later.

[0038] The nickel plating film 24 is disposed so as to cover the external electrodes 22. The tin plating film 25 is disposed so as to cover the nickel plating film 24.

[0039] The nickel plating film 24 can prevent the external electrodes 22 from being eroded by solder when mounting the multilayer ceramic capacitor 1. The tin plating film 25 can improve the wettability of the solder when mounting the multilayer ceramic capacitor 1, making mounting easier.

[0040] The size of the multilayer ceramic capacitor 1 is not particularly limited. The length in the longitudinal direction of the multilayer ceramic capacitor 1 including the ceramic body 2 and the terminal electrodes is preferably 0.2 mm or more and 10 mm or less. The length in the height direction of the multilayer ceramic capacitor 1 including the ceramic body 2 and the terminal electrodes is preferably 0.1 mm or more and 5 mm or less. The length in the width direction of the multilayer ceramic capacitor 1 including the ceramic body 2 and the terminal electrodes is preferably 0.1 mm or more and 10 mm or less.

[0041] The external electrode 22 will be described in more detail. Fig. 4 is an enlarged view of the area indicated by the frame 70 in Fig. 2. The external electrode 22 includes a metal domain 28 and a glass domain 40. The metal domain 28 is a region formed by the metal contained in the conductive paste after firing. The glass domain 40 is a region formed by the glass contained in the conductive paste after firing.

[0042] The surface of the external electrode 22 facing the nickel plating film 24 is referred to as the surface 26. At least a portion of the glass domain 40 of the external electrode 22 extends from the surface of the ceramic body 2 to the surface 26 of the external electrode 22. The glass domain 40 serves as a degassing path when the conductive paste is fired. A degassing path is a path that allows gas generated when the conductive paste is fired to escape to the outside of the external electrode 22. Arrow 60 shown in FIG. 4 indicates an example of a degassing path. The formation of the degassing path 60 makes it difficult for gas to remain inside the external electrode 22 when the conductive paste is fired. As a result, blisters are less likely to form in the external electrode 22.

[0043] In the multilayer ceramic capacitor 1 of this embodiment, the occupancy rate of the glass domains 40 on the surface of the ceramic body 2 included in the portion where the external electrode 22 is arranged on at least one of the first side surface 5, the second side surface 6, the first main surface 3, and the second main surface 4, and in the corner portions continuous with that surface in the longitudinal direction, is 40% or more and 60% or less. This will be described with reference to the drawings. The portions of the first side surface 5, the second side surface 6, the first main surface 3, and the second main surface 4 where the external electrode 22 is arranged are referred to as electrode arrangement portions.

[0044] Fig. 5 is a conceptual diagram for explaining the arrangement of glass domains 40. Fig. 5 shows an LT cross section of multilayer ceramic capacitor 1. Fig. 5 also shows second main surface 4 and second end surface 8. The following description also applies to other surfaces.

[0045] Position 72 in Figure 5 is the position where the second main surface 4 starts to tilt toward the second end surface 8. Position 74 in Figure 5 is the position where the second end surface 8 starts to tilt toward the second main surface 4. The portion of the ceramic body 2 from position 72 to position 74 is defined as a corner portion 78.

[0046] 5 is the position of the end of the external electrode 22 on the second main surface 4. The range from position 72 to position 76 is defined as an electrode arrangement portion 77.

[0047] The sum of the length in the longitudinal direction L of the surface of the ceramic body 2 at the electrode arrangement portion 77 and the length in the longitudinal direction L of the surface 64 of the ceramic body 2 at the corner portion 78 is defined as length 62. That is, in the example shown in Fig. 5 , length 62 is the length of a straight line in the longitudinal direction L from a position 76 of the end of the external electrode 22 on the second main surface 4 to the second end face 8.

[0048] Five glass domains, first glass domain 41 to fifth glass domain 45, are arranged on second main surface 4. Sixth glass domain 46 is arranged in corner portion 78. The lengths of the respective glass domains in the longitudinal direction L are indicated by lengths 51 to 56.

[0049] Here, the ratio of the sum of lengths 51 to 56 to length 62 is calculated. In this embodiment, this ratio is 40% to 60%. This indicates that the occupancy rate of glass on the surface of the ceramic body 2 at the corners and the side or main surface is 40% to 60%.

[0050] Furthermore, in the multilayer ceramic capacitor 1 of this embodiment, the percentage of the number of glass domains 40 arranged in the electrode arrangement portion 77 that extend from the surface of the ceramic body 2 to the surface 26 of the external electrode 22 is 10% or more and 30% or less. In the example shown in Fig. 5, five glass domains, a first glass domain 41 to a fifth glass domain 45, are arranged in the electrode arrangement portion 77. Of these, the first glass domain 41 extends from the surface of the ceramic body 2 to the surface 26 of the external electrode 22. In other words, of the five glass domains, one glass domain extends from the surface of the ceramic body 2 to the surface 26 of the external electrode 22. This percentage is 20%.

[0051] In this way, by having a glass occupancy rate of 40% or more and 60% or less, and a proportion of glass domains 40 in which glass extends columnarly to the surface 26 of the external electrode 22 of 10% or more and 30% or less, it is possible to suppress the formation of blisters on the external electrode 22 when the conductive paste is fired.

[0052] In particular, the occurrence of blisters can be suppressed at corner portions 78 where the external electrode 22 is thin and where blisters are likely to occur.

[0053] An example of a method for forming such glass domains 40 is shown below. First, there is a method of blending two or more types of metal powders with different particle sizes and particle shapes into a conductive paste. For example, copper powder with a D50 average particle size of 1 μm and spherical particle shape and copper powder with a D50 average particle size of 4 μm and flat particle shape are blended into the conductive paste. The flat copper powder acts as beams, ensuring degassing paths and enabling the formation of columnar glass domains 40.

[0054] Figure 6 is a diagram showing the state after the conductive paste for the external electrodes 22 has been applied to the ceramic body 2 and dried. Figure 6 shows a portion of the LT cross section of the multilayer ceramic capacitor 1. As shown in the circle 66 in Figure 6, among the metal powder particles 27, there is a portion where multiple flat-shaped metal powder particles 27 are continuous from the surface of the ceramic body 2 in the thickness direction of the conductive paste. This portion ensures a degassing path when the conductive paste is fired. The flat-shaped metal powder particles 27 with large particle diameters are connected together, forming beams that ensure a path in the thickness direction.

[0055] Furthermore, in the corner portion 78, only one flat-shaped metal powder particle 27 exists in the film thickness direction. A degassing path is formed around this single metal powder particle 27.

[0056] When two or more types of metal powders with different particle sizes are mixed into the conductive paste, the particle sizes of the metal powders are not limited to the above-mentioned 1 μm and 4 μm, and can be changed as appropriate, for example, to 1.2 μm and 3.6 μm.

[0057] The state of the conductive paste after baking will be described with reference to Fig. 7. Fig. 7 is a diagram showing the conductive paste after baking. Fig. 7, like Fig. 6, shows a part of the LT cross section of the multilayer ceramic capacitor 1.

[0058] 7, a portion is formed in which the glass domain 40 continues from the surface of the ceramic body 2 toward the surface of the external electrode 22. This portion serves as a degassing path 60.

[0059] The degassing paths 60 are formed not only on the second end face 8 but also on the second main surface 4. Although not shown in FIG. 7 , degassing paths 60 are similarly formed on other surfaces of the ceramic body 2.

[0060] In FIG. 7 , glass domain 40 is interrupted in some places between the surface of ceramic body 2 and the surface of external electrode 22. This is because FIG. 7 shows only one cross section. As will be explained later with reference to FIG. 8 , glass domain 40 has a three-dimensional extent. In other words, glass domain 40 forms a three-dimensional network. Therefore, even if glass domain 40 is interrupted on the page of FIG. 7 , glass domain 40 is connected on the front side or the back side of the page.

[0061] As a method for forming glass domains 40, a method in which two or more types of metal powders with different particle sizes and shapes are blended into a conductive paste has been described. In addition to using such metal powders, the columnar glass domains 40 are more likely to be formed by setting the softening point of the glass higher than the temperature at which necking due to surface diffusion between the finer metal powders of the two types of metal powders begins. This is because necking between the metal powders occurs faster than the softening of the glass, forming cavities, which makes it easier for the glass to move toward the surface 26 of the external electrode 22. The baking temperature can be, for example, 650°C or higher and 950°C or lower.

[0062] The flatness of the flat copper powder is preferably low. The flatness of the flat copper powder can be, for example, 1.05 or more and 2 or less.

[0063] The glass particles contained in the conductive paste preferably have a small particle size. The D50 average particle size of the glass particles can be, for example, 0.5 μm or more and 2.2 μm or less, preferably 0.5 μm or more and 1.0 μm or less.

[0064] Furthermore, it is preferable that the ratio of the particle size of the glass particles to the particle size of the flat copper powder is large. For example, the ratio of the D50 average particle size of the glass particles to the D50 average particle size of the flat copper powder can be 1 or more and 4 or less.

[0065] The three-dimensional structure of the glass domains 40 will be described with reference to FIG. 8 . FIG. 8 is a 3D-FIB (Focused Ion Beam)-SEM (Scanning Electron Microscope) image of the external electrode 22 in the LT cross section. SEM images of successive cross sections are joined together to form a single image. The striped patterns depicted in one glass domain 40 in FIG. 8 each represent a glass domain 40 observed in a different cross section on the far side of the page.

[0066] As shown in FIG. 8, the glass domains 40 extend not only on the paper surface but also into the depth of the paper surface, forming a three-dimensional network.

[0067] In the external electrode 22 of this embodiment, the glass domain 40 occupies more than two-thirds of the length of the external electrode 22 in the film thickness direction in the external electrode 22 arranged on at least one of the first side surface 5, the second side surface 6, the first main surface 3, and the second main surface 4.

[0068] Here, "occupying two-thirds or more of the length in the film thickness direction" means that if glass domain 40 exists at any position on a plane perpendicular to the film thickness direction within external electrode 22, and it is determined that glass domain 40 exists at that film thickness position, then glass domain 40 exists at a position that is at least two-thirds of the length in the film thickness direction of external electrode 22. In other words, the position where glass domain 40 exists at that film thickness position occupies two-thirds or more of the film thickness.

[0069] The method for measuring the length and thickness of each part will be described below. The multilayer ceramic capacitor 1 is polished to the center position in the width direction W. The LT cross section exposed by polishing is then observed using an optical microscope or the like. The length, thickness, etc. can be measured from the observed LT cross section.

[0070] A method for manufacturing the multilayer ceramic capacitor 1 will now be described. First, a conductive paste for the dielectric sheets and the internal electrode layers is prepared. The conductive paste for the dielectric sheets and the internal electrode layers contains a binder and a solvent. The binder and the solvent may be a known organic binder and organic solvent, for example.

[0071] A conductive paste for the internal electrode layers is printed on the dielectric sheet in a predetermined pattern. The internal electrode layer pattern is formed by printing the conductive paste. The printing can be performed by, for example, screen printing or gravure printing.

[0072] A predetermined number of dielectric sheets for the outer layer portions are stacked. No internal electrode layer patterns are printed on the dielectric sheets for the outer layer portions. Dielectric sheets with internal electrode layer patterns printed on them are stacked in order on top of the stacked dielectric sheets. Furthermore, a predetermined number of dielectric sheets for the outer layer portions are stacked on top of those. A laminated sheet is produced by stacking these layers.

[0073] The laminated sheet is pressed in the height direction to produce a laminated block. The pressing method can be isostatic pressing.

[0074] The laminated block is cut to a predetermined size. This cutting process cuts out laminated chips. When cutting, the corners and ridges of the laminated chips may be rounded. The rounding method can be barrel polishing.

[0075] The laminated chip is fired to produce a ceramic body. The firing temperature is preferably 900° C. or higher and 1110° C. or lower. The firing temperature can be changed depending on the materials of the dielectric and internal electrode layers.

[0076] Forming the terminal electrodes. First, a conductive paste that will become the external electrodes 22 is applied to the two end surfaces of the ceramic body 2. The conductive paste includes glass, metal, etc. The conductive paste can be applied by a method such as dipping. After application, firing is performed to form the external electrodes 22. The firing temperature is preferably 500°C or higher and 900°C or lower. The firing time is preferably 30 minutes or higher and 2 hours or lower.

[0077] Nickel plating films 24 are formed on the surfaces of the external electrodes 22. Furthermore, tin plating films 25 are formed on the surfaces of the nickel plating films 24. The nickel plating films 24 and tin plating films 25 can be formed by barrel plating or the like. In this manner, the multilayer ceramic capacitor 1 can be manufactured.

[0078] 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.

[0079] REFERENCE SIGNS LIST 1 Multilayer ceramic capacitor 2 Ceramic body 3 First main surface 4 Second main surface 5 First side surface 6 Second side surface 7 First end surface 8 Second end surface 27 Metal powder 28 Metal domain 40 Glass domain 60 Degassing path 77 Electrode placement portion 78 Corner portion

Claims

1. A multilayer ceramic capacitor comprising: a ceramic body including a plurality of laminated dielectric layers and a plurality of laminated internal electrode layers, the ceramic body having six surfaces including a first main surface and a second main surface opposing each other in a height direction, a first side surface and a second side surface opposing each other in a width direction perpendicular to the height direction, and a first end surface and a second end surface opposing each other in a length direction perpendicular to the height direction and the width direction; and an external electrode provided on the ceramic body and connected to some of the internal electrode layers, wherein when a portion of the surfaces of the ceramic body where the external electrode is arranged is defined as an electrode arrangement portion, and a portion of the ceramic body where two of the surfaces intersect is defined as a corner portion, the external electrode includes a glass domain, and a ratio of the sum of the longitudinal lengths of the glass domain to the sum of the longitudinal lengths of the surface of the ceramic body of the electrode arrangement portion on at least one of the first side surface, the second side surface, the first main surface, and the second main surface and the surface of the ceramic body of the corner portion continuous with the surface of the electrode arrangement portion in the longitudinal direction is 40% or more and 60% or less, a ratio of the number of glass domains extending from a surface of the ceramic body to a surface of the external electrode to the number of glass domains arranged in the electrode arrangement portion is 10% or more and 30% or less.

2. The multilayer ceramic capacitor according to claim 1, wherein in the external electrode disposed on at least one of the first side surface, the second side surface, the first main surface, and the second main surface, the glass domain occupies two-thirds or more of the length of the external electrode in the film thickness direction.

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