Ceramic electronic component and method for manufacturing same

Abstract

A multilayer ceramic electronic component according to one embodiment of the present invention comprises an element body that comprises a capacitor unit in which a plurality of dielectric layers that contain a ceramic as a main component and a plurality of internal electrode layers are alternately stacked. The internal electrode layers contain carbon nanotubes, the dielectric layers have a relative dielectric constant of 1,000 or more, and the internal electrode layers have a modulus of continuity of 45% or more.

Description

Ceramic electronic components and their manufacturing method

[0001] The present invention relates to a ceramic electronic component and a method for manufacturing the same.

[0002] As electronic devices become smaller, further miniaturization is also required for ceramic electronic components such as multilayer ceramic capacitors that are mounted on the electronic devices.

[0003] A multilayer ceramic capacitor is a ceramic electronic component that includes an element body containing a capacitive section in which multiple dielectric layers, each primarily made of ceramic, and multiple internal electrode layers are alternately stacked. Measures for reducing the size and increasing the capacitance of such ceramic electronic components include increasing the capacitance value per layer by thinning the dielectric layers, and also increasing the number of layers for a given capacitive section thickness by thinning the dielectric layers and internal electrode layers.

[0004] However, when the dielectric layers are thinned, internal electrode layers with opposite polarities may come into contact with each other, causing a short circuit, due to thermal stress during mounting on a substrate, mechanical stress due to bending of the substrate after mounting on the substrate, thermal runaway in a high-temperature load environment, etc. A multilayer ceramic capacitor in which a short circuit has occurred often loses its function as a multilayer ceramic capacitor.

[0005] In response to this, a multilayer ceramic capacitor has been proposed in which short circuits are suppressed by disposing, for example, graphene as a conductive layer between internal electrode layers (see Patent Document 1). In Patent Document 1, the conductive layer is placed on the internal electrode layers by, for example, a film transfer method.

[0006] The multilayer ceramic capacitor described in Patent Document 1 is said to have a conductive layer disposed between the internal electrode layers, which prevents contact between the internal electrode layers, which is likely to occur during the compression and sintering processes of the multilayer ceramic capacitor, thereby reducing the defect rate caused by short circuits.

[0007] Furthermore, multilayer ceramic capacitors have been proposed that suppress short-circuit defects by providing internal electrode layers with electrode portions containing a conductive carbon material such as carbon nanotubes (see Patent Documents 2 and 3). The multilayer ceramic electronic components described in Patent Documents 2 and 3 have fuse functions because the internal electrode layers include electrode portions containing a conductive carbon material such as carbon nanotubes.

[0008] Specifically, in the multilayer ceramic capacitors described in Patent Documents 2 and 3, a first electrode portion containing a conductive carbon material such as carbon nanotubes is disposed in the end margin region, and a second electrode portion containing a metal material such as nickel is disposed in the capacitance region. As a result, when a short circuit occurs and an overcurrent flows, only the first electrode portion burns out, thereby preventing the occurrence of short circuit defects. Furthermore, since a normal circuit without a short circuit is maintained, the functionality of the multilayer ceramic electronic component itself can be maintained.

[0009] JP 2013-042110 A JP 2020-141016 A JP 2020-141017 A

[0010] The element body of a multilayer ceramic electronic component is generally fired at a temperature of around 1200°C, for example, in a temperature range of about 1150°C to 1250°C, for the purpose of promoting grain growth of the dielectric material constituting the dielectric layers and increasing the dielectric constant. However, in the multilayer ceramic capacitor described in Patent Document 1, the graphene disposed as the conductive layer becomes unstable when fired at this temperature range. For example, when fired at a temperature exceeding 1200°C, the graphene layer completely disappears, and the conductive layer becomes nonexistent.

[0011] For this reason, the multilayer ceramic capacitor described in Patent Document 1, which includes a graphene layer as a conductive layer, needs to be fired at a low temperature of 900° C. to 1100° C. Firing at such a low temperature does not allow sufficient grain growth of the dielectric material, making it impossible to obtain a dielectric layer with a sufficient dielectric constant.

[0012] Furthermore, Patent Documents 2 and 3 state that the firing temperature must be 1000° C. or less in order to prevent the conductive carbon material from being burned during the firing process, and further state that the firing temperature for the green chip is preferably 250° C. or less.

[0013] Therefore, in the multilayer ceramic electronic components described in Patent Documents 2 and 3, similar to Patent Document 1, it is difficult to obtain dielectric layers having a sufficient dielectric constant.

[0014] Furthermore, in multilayer ceramic electronic components in which the internal electrode layers are thinned to increase the number of layers within a specified capacitance section thickness, the dielectric material, which grows as grains during firing, penetrates the internal electrode layers, which can easily reduce the continuity of the internal electrode layers.In multilayer ceramic electronic components with a reduced continuity of the internal electrode layers, voltage cannot be applied to the parts where the internal electrode layers are broken, which can result in insufficient performance.

[0015] The present invention has been made in view of the above circumstances, and has as its object to provide a ceramic electronic component having a high continuity ratio of internal electrode layers and a large capacitance, and a method for manufacturing the same.

[0016] The present inventors have conducted extensive research to achieve the above-mentioned object, and have found that by forming an internal electrode pattern containing carbon nanotubes on a green sheet during the manufacture of a ceramic electronic component, the carbon nanotubes remain in the internal electrode layer even when the element is formed by firing at a temperature exceeding 1000°C, thereby achieving the above-mentioned object, and have completed the present invention.

[0017] That is, the present invention includes the following aspects. [1] A ceramic electronic component comprising an element body including a capacitive section in which a plurality of dielectric layers mainly composed of ceramic and a plurality of internal electrode layers are alternately stacked, the internal electrode layers containing carbon nanotubes, the dielectric constant of the dielectric layers being 1000 or more, and the continuity rate of the internal electrode layers being 45% or more. [2] The ceramic electronic component according to aspect [1], in which the internal electrode layers contain carbon nanotubes and a metal. [3] The ceramic electronic component according to aspect [2], in which the internal electrode layers are mixed layers made of carbon nanotubes and a metal. [4] The ceramic electronic component according to aspect [2], in which the content of carbon nanotubes in the internal electrode layers is 4% by mass or more and 18% by mass or less with respect to the total of the carbon nanotubes and the metal. [5] The ceramic electronic component according to any one of aspects [1] to [4], in which the thickness of each of the plurality of dielectric layers and the plurality of internal electrode layers is 1 μm or less. [6] The ceramic electronic component according to any one of aspects [1] to [5], wherein the dielectric layers are made of barium titanate. [7] The ceramic electronic component according to any one of aspects [2] to [6], wherein the metal is Ni. [8] A method for manufacturing a ceramic electronic component, comprising: forming an internal electrode pattern containing carbon nanotubes on a dielectric green sheet to form a lamination unit; laminating a plurality of the lamination units to form a pre-fired element body including an unfired capacitive section; and firing the pre-fired element body at a temperature higher than 1000°C and lower than or equal to 1250°C to obtain a element body including a capacitive section. [9] The method for manufacturing a ceramic electronic component according to aspect [8], wherein the internal electrode pattern is formed by printing.

[0018] According to the present invention, since the element body can be fired at 1000° C. or higher, it is possible to realize a ceramic electronic component having a dielectric layer with a sufficient dielectric constant.

[0019] Furthermore, in the ceramic electronic component of the present invention, the internal electrode layers contain carbon nanotubes, thereby making it possible to improve the continuity ratio of the internal electrode layers.

[0020] Furthermore, the ceramic electronic component of the present invention can improve its strength by including carbon nanotubes in the internal electrode layers. Therefore, even when external stress or the like is applied, damage to the element body can be suppressed. Furthermore, even if a crack occurs in the capacitive section due to external stress or the like, the ceramic electronic component can maintain its function as long as the carbon nanotube fibers remain intact.

[0021] Furthermore, by including carbon nanotubes in the internal electrode layers of the ceramic electronic component of the present invention, it is possible to reduce the amount of metals such as nickel used as constituent materials for conventional internal electrode layers, thereby reducing the use of nickel, a rare metal resource, and reducing the mass of the resulting multilayer ceramic capacitor.

[0022] 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor, and FIG. 2 is a cross-sectional view used to explain the continuity ratio of internal electrode layers.

[0023] Hereinafter, embodiments will be described with reference to the drawings.

[0024] <Multilayer ceramic capacitor> A multilayer ceramic capacitor comprises an element body including a capacitive section in which a plurality of dielectric layers and a plurality of internal electrode layers, each of which is primarily composed of ceramic, are alternately stacked, and at least two external electrodes formed on the surface of the element body so as to be spaced apart from each other, and each external electrode is connected to a portion of the internal electrode layer extended from the capacitive section.

[0025] The element body of the multilayer ceramic capacitor has an outer shape of a roughly rectangular parallelepiped, and has upper and lower surfaces that face each other in the height direction when mounted on a substrate, two end surfaces that contact the upper and lower surfaces respectively and face each other in the length direction of the element body, and two side surfaces that contact the upper, lower and end surfaces respectively and face each other in the width direction of the element body.

[0026] The stacking direction of the multiple dielectric layers and multiple internal electrode layers in the multilayer ceramic capacitor may be the height direction of the element body, the length direction of the element body, the width direction of the element body, or any other direction.

[0027] In the element body, an internal electrode layer is arranged on the outermost layer in the stacking direction of the capacitance section, and the outermost internal electrode layer of the capacitance section is covered by a cover layer. The cover layer functions as a protective section for protecting the capacitance section composed of the dielectric layer and the internal electrode layer. The cover layer may be arranged on the upper and lower surfaces facing each other in the height direction of the element body, but may also be arranged on a surface other than the upper and lower surfaces depending on the relationship between the element body and the stacking direction of the capacitance section. The cover layer may be primarily composed of a ceramic material. The materials of the cover layer and the dielectric layer may be the same or different.

[0028] In the element body, a side margin is provided outside the capacitive section, perpendicular to the stacking direction of the capacitive section. The internal electrode layers are not drawn out in the side margin, and the side margin functions as a protective section for protecting the capacitive section composed of the dielectric layers and the internal electrode layers. That is, the side margin is an area located outside the capacitive section when viewed from the stacking direction, and from which the internal electrode layers are not drawn. The side margin may form the side of the element body, but depending on the positional relationship between the element body and the capacitive section in the stacking direction and the formation surface of the external electrodes formed on the surface of the element body, it may form a surface other than the side of the element body, or it may form both the side and the other surface. The side margin may be primarily composed of a ceramic material. The materials of the side margin and the dielectric layer may be the same or different. The side margin is an area that does not generate capacitance.

[0029] The element body has an end margin portion on the outside of the capacitive section, where the internal electrodes are extended to the surface of the element body. The end margin portion is a region outside the capacitive section adjacent to the capacitive section as viewed in the stacking direction, where the internal electrode layers are extended. The end margin portion may form an end face of the element body, but depending on the positional relationship between the element body and the capacitive section in the stacking direction and the formation surface of the external electrodes formed on the element body surface, the end margin portion may form a surface other than the end face of the element body, or may form both the end face and the other surface. If the element body has one surface from which the internal electrode layers are extended, there is one end margin portion, and if the element body has two surfaces, there are two end margin portions. The end margin portion may be primarily composed of a ceramic material. The end margin portion and the dielectric layer may be made of the same or different materials. Although the end margin portion may generate stray capacitance between internal electrode layers extended to the same surface, it is basically a region that can be considered to generate no electrostatic capacitance.

[0030] The multiple internal electrode layers are each extended to an end margin and electrically connected to an external electrode provided outside the end margin. The internal electrode layers may be extended to end margins on opposing surfaces of the element body, or to end margins on adjacent surfaces of the element body, or may be extended to different regions of the same end margin. The external electrodes may extend from the surface of the element body with the end margin from which the internal electrode layers are extended to another surface of the adjacent element body, as long as they are spaced apart from each other.

[0031] The ceramic electronic component of the present invention will be described below with reference to Fig. 1. Fig. 1 shows an example of a multilayer ceramic capacitor, which is a ceramic electronic component, and the present invention is not limited to this embodiment.

[0032] Fig. 1 is a partial cross-sectional perspective view of a multilayer ceramic capacitor 100. The multilayer ceramic capacitor 100 illustrated in Fig. 1 comprises an element body 10 having a substantially rectangular parallelepiped shape, and external electrodes 20a and 20b spaced apart from each other and provided on two end faces of the element body 10. The surfaces of the element body 10 that face each other in the vertical direction (Z-axis direction) are the top and bottom faces, respectively, and the other two faces of the element body 10 other than the end faces, top and bottom faces are side faces.

[0033] In the multilayer ceramic capacitor 100 shown in FIG. 1, the external electrodes 20a and 20b provided on the end surfaces extend to the top, bottom, and two side surfaces of the element body 10 in the stacking direction. However, the external electrodes 20a and 20b are spaced apart from each other. In FIG. 1, the X-axis direction (first direction) is the length direction of the element body 10, and is the direction in which the external electrodes 20a and 20b face each other. The Y-axis direction (second direction) is the width direction of the internal electrode layers. The Z-axis direction (third direction) is the stacking direction. The X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other.

[0034] In the multilayer ceramic capacitor 100 shown in Fig. 1, the element body 10 has a configuration in which dielectric layers 11 containing a ceramic material that functions as a dielectric and internal electrode layers 12 are alternately stacked, with the multiple dielectric layers 11 stacked with the internal electrode layers 12 interposed between. Some of the internal electrode layers 12 are extended to end margin portions 16a, reach the surface of the element body 10 on which the external electrodes 20a are provided, and are electrically connected to the external electrodes 20a. Other internal electrode layers 12 are extended to end margin portions 16b (not shown), reach the surface of the element body 10 on which the external electrodes 20b are provided, and are electrically connected to the external electrodes 20b. As a result, each of the internal electrode layers 12 is electrically connected to either the external electrodes 20a or the external electrodes 20b.

[0035] The region where the internal electrode layer 12 connected to the external electrode 20a and the internal electrode layer 12 connected to the external electrode 20b face each other is a region that generates capacitance in the multilayer ceramic capacitor 100, and is called a capacitance region. In the multilayer ceramic capacitor 100 shown in Fig. 1, this region is shown as a capacitance region 14. The capacitance region 14 is a region where adjacent internal electrode layers 12 connected to different external electrodes, the external electrode 20a and the external electrode 20b, face each other, and is a region of one layer called a dielectric layer 11.

[0036] In the element body 10, the regions extending from the two side surfaces of the element body 10 to the internal electrode layers 12 are side margins 15. In the multilayer ceramic capacitor 100 shown in Fig. 1, the side margins 15 are present on the side surfaces of the element body 10. As described above, the side margins 15 are regions that do not generate capacitance.

[0037] In the multilayer ceramic capacitor 100, an internal electrode layer 12 is arranged on the outermost layer in the stacking direction (Z-axis direction: third direction) of the capacitance section, and the upper and lower surfaces of the capacitance section are covered with a cover layer 13.

[0038] The size of the multilayer ceramic capacitor 100 is not particularly limited and can be changed appropriately depending on the application. The size of the multilayer ceramic capacitor 100 is, for example, 0.25 mm in length, 0.125 mm in width, and 0.125 mm in height, or 0.4 mm in length, 0.2 mm in width, and 0.2 mm in height, or 0.6 mm in length, 0.3 mm in width, and 0.3 mm in height, or 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, or 3.2 mm in length, 1.6 mm in width, and 1.6 mm in height, or 4.5 mm in length, 3.2 mm in width, and 2.5 mm in height. The size of the multilayer ceramic capacitor 100 may be, for example, length > width ≥ height, width > length ≥ height, height > length ≥ width, or height > width ≥ length.

[0039] The materials and other details of the components constituting the multilayer ceramic capacitor 100 of the present disclosure will be described below.

[0040] [Dielectric Layer] The dielectric layer in the ceramic electronic component of the present disclosure is not particularly limited as long as it is mainly composed of ceramic, and may be appropriately selected depending on the properties required for the ceramic electronic component. ３ The perovskite structure is a ceramic material having a non-stoichiometric composition represented by ABO ３－α Here, α in the formula means deviation from stoichiometry. Hereinafter, α will be omitted.

[0041] The dielectric layer is formed of a material having the general formula ABO ３ Examples of ceramic materials having a perovskite structure represented by the formula: BaTiO ３ (barium titanate), CaZrO ３ (Calcium zirconate), CaTiO ３ (Calcium titanate), SrTiO ３ (strontium titanate), Ba that forms a perovskite structure １-ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３ (0≦x≦1, 0≦y≦1, 0≦z≦1), etc. Among them, barium titanate (BaTiO ３ ) as the main component is preferred.

[0042] The dielectric layers in the ceramic electronic component according to the present disclosure have a dielectric constant of 1000 or more. Here, the dielectric constant refers to the ratio of the dielectric constant to the dielectric constant of a vacuum. In the ceramic electronic component according to the present invention, the element body is fired at 1000°C or more, which allows the dielectric constant of the dielectric layers to be increased.

[0043] The dielectric constant of the dielectric layer is preferably 1100 or more, more preferably 1200 or more, even more preferably 1300 or more, still more preferably 1400 or more, and particularly preferably 1500 or more.

[0044] The thickness of each dielectric layer is not particularly limited, but is, for example, 0.05 μm to 5 μm, or 0.1 μm to 3 μm, or 0.2 μm to 1 μm.

[0045] [Internal Electrode Layer] The internal electrode layer in the ceramic electronic component according to the present disclosure contains carbon nanotubes (CNTs).

[0046] The carbon nanotubes (CNTs) contained in the internal electrode layers of the ceramic electronic component according to the present disclosure are not particularly limited, and examples thereof include single-walled carbon nanotubes (hereinafter referred to as "SWCNTs") each having a single six-membered ring network (graphene sheet) made of carbon rolled into a cylindrical shape, double-walled carbon nanotubes (hereinafter referred to as "DWCNTs") each having two graphene sheets rolled concentrically, and multi-walled carbon nanotubes (hereinafter referred to as "MWCNTs") each having multiple graphene sheets rolled concentrically.

[0047] In the ceramic electronic component of the present disclosure, SWCNT, DWCNT, and MWCNT may be used alone or in combination. Among these, SWCNT or DWCNT is more preferred, and SWCNT is particularly preferred.

[0048] The diameter of the carbon nanotube is not particularly limited and may be, for example, 100 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, or 15 nm or less.

[0049] When the diameter of the carbon nanotubes is 100 nm or less, a network structure of the carbon nanotubes is easily formed in the internal electrode layers, which results in an improvement in the continuity rate of the internal electrode layers and further enables an increase in the strength of the internal electrode layers.

[0050] On the other hand, the diameter of the carbon nanotubes may be, for example, 0.8 nm or more, or 1 nm or more. When the diameter of the carbon nanotubes is 0.8 nm or more, the dispersibility of the carbon nanotubes in the internal electrode layers is good.

[0051] The fiber length of the carbon nanotubes is not particularly limited, but may be, for example, 0.05 μm or more and 5 μm or less, or 0.1 μm or more and 2.0 μm or less.

[0052] When the fiber length of the carbon nanotubes is 0.05 μm or more, a network structure of the carbon nanotubes is easily formed sufficiently in the internal electrode layer. Furthermore, when the fiber length of the carbon nanotubes is equal to or greater than the thickness of the internal electrode layer, a network structure of the carbon nanotubes in the lateral direction is easily formed sufficiently in the internal electrode layer. As a result, the strength of the internal electrode layer can be improved, and further, the continuity rate of the internal electrode layer can be increased.

[0053] On the other hand, when the fiber length of the carbon nanotubes is 5 μm or less, the dispersibility of the carbon nanotubes in the internal electrode layers is good.

[0054] The diameter and fiber diameter of the carbon nanotube are determined by measuring the diameter and length of 100 carbon nanotubes using a scanning electron microscope (SEM) and calculating the average value of each.

[0055] The aspect ratio (fiber length / diameter) of the carbon nanotubes is not particularly limited, but may be, for example, 30 or more and 50,000 or less. The aspect ratio of the carbon nanotubes may be 50 or more and 30,000 or less, or 100 or more and 20,000 or less. When the aspect ratio of the carbon nanotubes is within the above range, the dispersibility of the carbon nanotubes in the internal electrode layers is good.

[0056] The carbon nanotube may have any shape as long as it is tubular, for example, a needle shape, a cylindrical tube shape, a fishbone shape (fishbone, stacked cup shape), a playing card shape (platelet), a coil shape, or the like.

[0057] Carbon nanotubes can be produced by, for example, an arc discharge method, a laser ablation method, a chemical vapor deposition method (hereinafter also referred to as a "CVD method"), or the like. The carbon nanotubes used in the ceramic electronic component of the present disclosure may be produced by any of these methods. Note that the carbon nanotubes used in the ceramic electronic component of the present disclosure may be commercially available products.

[0058] The carbon nanotubes used in the ceramic electronic component of the present disclosure may be subjected to a surface treatment in advance, such as ion implantation, sputter etching, or plasma treatment.

[0059] The content of carbon nanotubes in the internal electrode layers is preferably 4% by mass or more and 18% by mass or less, more preferably 5% by mass or more and 15% by mass or less, and even more preferably 5% by mass or more and 10% by mass or less, relative to 100% by mass of the total of the metal and carbon nanotubes constituting the internal electrode layers.

[0060] When the content of carbon nanotubes in the internal electrode layers is within the above range, a network structure of carbon nanotubes is easily formed in the internal electrode layers, which results in an improvement in the strength of the internal electrode layers and an increase in the continuity rate of the internal electrode layers.

[0061] In the ceramic electronic component according to the present disclosure, the metal that forms the internal electrode layers together with the carbon nanotubes is not particularly limited, and may be any known metal that can form internal electrode layers. For example, nickel (Ni) can be preferably used.

[0062] When the internal electrode layers of the ceramic electronic component of the present disclosure contain both metal and carbon nanotubes, the internal electrode layers may be mixed layers in which metal and carbon nanotubes are mixed.

[0063] The carbon nanotube content in the internal electrode layers of the multilayer ceramic capacitor 100 can be determined by the following procedure, for example: Measurement is carried out for three or more different internal electrode layers, and the average is taken as the content.

[0064] First, a cross section (a cross section between 1 / 3 and 2 / 3 of the width direction dimension) passing through the vicinity of the center in the width direction (Y-axis direction: second direction) of the element body 10 of the multilayer ceramic capacitor 100, in which the dielectric layers 11 and the internal electrode layers 12 are stacked, is exposed by cutting, polishing, or other means. The cross section is parallel to the direction in which the external electrodes 20a and 20b face each other (X-axis direction: first direction), and through which the multiple internal electrode layers 12 can be observed. The exposed cross section is near the center in the length direction (X-axis direction: first direction) of the element body 10 (a cross section between 1 / 3 and 2 / 3 of the length direction dimension). Next, osmium (Os) or platinum (Pt) is vapor-deposited on the exposed cross section to prepare a measurement sample. The vicinity of the center of the cross section of the obtained measurement sample is observed with a scanning electron microscope (SEM) or an electron probe micro analyzer (EPMA) at a magnification at which two or three of the internal electrode layers 12 are observed in the field of view, and the areas of the metal parts and the carbon nanotube parts of the internal electrode layers are determined from the difference in contrast in the electron beam image. Specifically, in the electron beam image, the area of ​​the metal parts and the carbon nanotube parts of the internal electrode layers is determined from the difference in contrast in the electron beam image. ３ The dielectric layers such as those made of nickel are white, the metals such as nickel that make up the internal electrode layers are grayish white, and the carbon nanotubes with a small atomic weight are black. These can be easily distinguished by the difference in brightness contrast. Image processing software may be used to measure the area. Next, when the density of the carbon nanotubes is 1 g / cm ３ Considering that the density of Ni, which is most commonly used as a metal constituting the internal electrode layers, is about 8.9 g / cm, the calculated area value of the carbon nanotubes is used as the virtual mass of the carbon nanotube portion of the internal electrode layers. ３Taking this into consideration, the calculated metal area value is multiplied by 8.9 to obtain the virtual mass of the metal portion of the internal electrode. Next, for each internal electrode layer, the percentage of the virtual mass of the carbon nanotubes relative to the total virtual mass of the carbon nanotube portion and the metal portion is calculated. Finally, the average value of the percentages obtained for each internal electrode layer is used as the content of carbon nanotubes in the internal electrode layer 12.

[0065] The continuity ratio of the internal electrode layers of the ceramic electronic component according to the present disclosure is 45% or more. If the continuity ratio of the internal electrode layers containing carbon nanotubes is 45% or more, the ceramic electronic component can exhibit sufficient capacitance.

[0066] The continuity ratio of the internal electrode layers can be determined by the following method: Measurement is carried out for 30 or more internal electrode layers, the continuity ratio of each layer is determined, and the average value is used.

[0067] Each multilayer ceramic capacitor is polished from the side to expose the internal electrode layers, and observed at a magnification of 5000 to 10000 times with a microscope or the like. As shown in FIG. 2, the length L0 of the observed portion is measured using a scale or the like of the microscope. Next, for one internal electrode layer, lengths L1, L2, ... Ln (n = 4 in FIG. 2) of the electrode portions within the range of L0 are measured to find the sum ΣLn, and ΣLn / L0 is calculated to find the continuity ratio of the layer.

[0068] The continuity of the internal electrode layer containing carbon nanotubes is preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, and particularly preferably 70% or more.

[0069] The thickness of each internal electrode layer is not particularly limited, but is, for example, 0.01 μm to 5 μm, or 0.05 μm to 3 μm, or 0.1 μm to 1 μm.

[0070] The number of stacked internal electrode layers is, for example, 10 to 5,000, 50 to 4,000, or 100 to 3,000.

[0071] [External Electrode] The external electrodes in the ceramic electronic component according to the present disclosure may be made of any conductive material, such as copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), silver (Ag), or gold (Au), or an alloy containing any of these metals as a main component.

[0072] The external electrodes may have multiple layers, and may have a plating layer provided on the surface thereof. Examples of the plating layer include a Ni plating layer, a Sn plating layer, a Cu plating layer, etc., and may be a laminate in which multiple plating layers are stacked.

[0073] [Cover Layer and Side Margin Portion] The materials for the cover layer and side margin portion of the ceramic electronic component according to the present disclosure are not particularly limited, as long as they have high electrical insulation and low permeability to degradation factors such as moisture. From the viewpoints of making uniform shrinkage during firing when manufacturing the ceramic electronic component body and alleviating internal stress in the ceramic electronic component, it is preferable that the materials for the cover layer and side margin portion be the same as the material for forming the dielectric layer.

[0074] <Method for manufacturing ceramic electronic components> The method for manufacturing ceramic electronic components of the present disclosure includes, for example, forming a laminate unit by forming an internal electrode pattern containing carbon nanotubes on a dielectric green sheet, forming a pre-fired capacitive section by stacking a plurality of laminate units, and firing the pre-fired capacitive section to form the capacitive section.

[0075] [Preparation of composition powder for dielectric green sheet] The composition powder for producing the dielectric green sheet can be obtained, for example, by mixing various raw material powders containing the constituent elements in a predetermined ratio and pre-firing (calcining). When mixing the various raw material powders in a predetermined ratio, various additives such as sintering aids may be further added, or various additives may be further added to the powder after calcination.

[0076] The method for mixing the raw material powders is not particularly limited as long as it allows the powders to be mixed uniformly while suppressing the inclusion of impurities, and either dry mixing or wet mixing may be employed. When wet mixing using a ball mill is employed as the mixing method, for example, partially stabilized zirconia (PSZ) balls may be used, and the mixture may be stirred for approximately 8 to 60 hours in a ball mill using an organic solvent such as ethanol or water as a dispersion medium, and then the dispersion medium may be evaporated and dried. If necessary, the particle size may be adjusted by pulverization, or by combining with classification.

[0077] The conditions for calcining the mixed raw material powders are not particularly limited as long as they allow the various raw material powders to react to obtain a predetermined dielectric green sheet composition powder. One example is calcining in the atmosphere at a temperature of 800°C to 1100°C for 1 hour to 10 hours. The powder after calcination may be processed into a green sheet as is, but crushing using a ball mill, stamp mill, or the like is preferred because it allows for the production of a smooth green sheet through a uniform slurry and improves sinterability.

[0078] When a commercially available powder of the dielectric green sheet composition is available, the subsequent steps may be carried out on this powder without carrying out the above-mentioned mixing and pre-firing of the raw material powders.

[0079] [Preparation of Dielectric Green Sheet] A dielectric green sheet can be prepared by mixing a powder of a dielectric green sheet composition with a binder and a dispersion medium to prepare a slurry, forming the slurry into a sheet, and drying it.

[0080] It is preferable to use a binder that can maintain the shape of the dielectric green sheet and that volatilizes without leaving carbon or the like during firing or the binder removal process that precedes firing. Examples of binders that can be used include polyvinyl alcohol-based, polyvinyl butyral-based, cellulose-based, urethane-based, and vinyl acetate-based binders. The amount of binder used is not particularly limited, but since it is removed in a later process, it is preferable to use as little as possible within a range that achieves the desired moldability and shape retention in order to reduce raw material costs.

[0081] The dispersion medium used should be one that can be easily removed by volatilization or the like after forming the sheet without causing aggregation of the dielectric green sheet composition powder and binder. Examples of the dispersion medium that can be used include water and alcohol-based solvents.

[0082] Components for adjusting the properties of the slurry, such as dispersants, plasticizers, and thickeners, may be added to the slurry.

[0083] The method for mixing the dielectric green sheet composition powder with the binder, dispersion medium, etc. is not particularly limited as long as the components are mixed uniformly while preventing impurities from being mixed in. One example is mixing using a ball mill.

[0084] The prepared slurry can be formed into a sheet by a commonly used method such as a die coater method or a doctor blade method. The prepared sheet-shaped product can be dried to obtain a dielectric green sheet. The prepared slurry may be applied to a substrate such as a PET (polyethylene terephthalate) film and dried to obtain a dielectric green sheet laminated on the substrate.

[0085] [Formation of Laminate Unit by Forming Internal Electrode Pattern] In the method for producing a ceramic electronic component according to the present disclosure, an internal electrode pattern containing carbon nanotubes is formed on the dielectric green sheet obtained above to obtain a laminate unit.

[0086] The internal electrode pattern can be formed by a known method, for example, by printing, in which an internal electrode paste containing carbon nanotubes is prepared and applied to a dielectric green sheet.

[0087] (Preparation of Internal Electrode Paste) The internal electrode paste containing carbon nanotubes can be obtained, for example, by mixing carbon nanotubes, metal powder containing optional metal elements, and a vehicle in a triple roll mill. The internal electrode paste may contain glass frit and a dielectric green sheet composition powder in addition to the above-mentioned metals that are essential components.

[0088] The type and amount of binder and solvent contained in the vehicle to be used are not particularly limited, and may be selected appropriately taking into consideration the viscosity of the internal electrode paste, ease of handling, compatibility with the dielectric green sheet, etc.

[0089] (Printing of Internal Electrode Paste) The printing of the internal electrode paste on the dielectric green sheet can be carried out, for example, using a screen mask on which a predetermined internal electrode pattern is formed. A lead pattern for leading out the internal electrode layer is also printed on the dielectric green sheet. This lead pattern may be formed simultaneously with the internal electrode pattern or separately. When formed separately, it may be carried out, for example, using a screen mask on which a predetermined lead pattern is formed. The lead pattern may be formed using the internal electrode paste, or a lead portion paste of a different composition may be prepared separately and used in the same procedure as the internal electrode paste.

[0090] When printing the internal electrode paste, a space that will become a side margin when an element including a capacitance section is formed may be printed. Furthermore, a space that will become an adjacent portion of the lead section in the end margin may be printed around the lead section. A dielectric paste for forming the side margin section or the end margin section may be printed in these spaces. The dielectric paste for forming the side margin section or the end margin section may be a paste using the same raw materials as the dielectric layer, or may be a paste using different raw materials. When the dielectric pastes for forming the side margin section and the end margin section are made of the same material, they may have the same composition or different compositions.

[0091] [Fabrication of a Compressed Body Including an Unsintered Capacitive Portion] In the method for manufacturing a ceramic electronic component according to the present disclosure, a plurality of the laminate units obtained above are stacked and compressed to obtain a compressed body including an unsintered capacitive portion. In a typical method for manufacturing a multilayer ceramic capacitor, a compressed body is produced by assembling a plurality of unsintered capacitive portions, and thus, a plurality of pre-fired bodies including the unsintered capacitive portions are formed by singulating the compressed body as described below.

[0092] The pressure-bonded body can be obtained, for example, by stacking a predetermined number of lamination units, each having an internal electrode pattern and an extraction pattern, and then pressure-bonding the lamination units together. The lamination and pressure-bonding can be performed by a conventional method, such as pressing the stacked lamination units together in the lamination direction while heating them, and thermocompression bonding by the action of a binder.

[0093] At this time, if the laminate unit on which the internal electrode pattern and the lead pattern are formed is fabricated on a base material, the laminate unit is laminated while peeling off the base material.

[0094] During lamination and compression bonding, green sheets that will become cover portions when the multilayer ceramic capacitor is completed may be added to both ends in the lamination direction. In this case, the added green sheets may have the same composition as the dielectric green sheets on which the internal electrode patterns and lead patterns are formed, or a different composition. From the viewpoint of making the shrinkage rate during firing uniform, it is preferable that the composition of the added green sheets be the same as or similar to the composition of the dielectric green sheets on which the internal electrode patterns and lead patterns are formed.

[0095] The compressed body obtained by compression bonding is cut into individual pieces by a commonly used method such as using a dicer or laser cutting, to obtain an unfired element body including an unfired capacitance portion, or a part thereof.

[0096] When the pressure-bonded body is singulated, if the side margins have not been formed in advance, i.e., if no space for the side margins has been provided or if no printing has been performed to form the side margins, the side margins are formed at this stage in the area outside the portion that will become the capacitance portion when viewed from the stacking direction, where the end margins including the lead-out portions of the internal electrode layers have not been formed, to obtain a pre-fired element body including an unfired capacitance portion. The method for forming the side margins is not particularly limited and can be appropriately selected from conventional methods such as applying a paste for forming the side margins or attaching a sheet. The material and composition for forming the side margins may be the same as or different from the material and composition for forming the dielectric layers.

[0097] [Fabrication of Element Body (Firing of Pre-Fired Element Body)] In the method for manufacturing a ceramic electronic component disclosed herein, an element body including a fired capacitive portion is obtained by firing a pre-fired element body including an unfired capacitive portion that has been singulated as described above. The element body has a capacitive portion in which dielectric layers and internal electrode layers are stacked, an end margin portion adjacent to the capacitive portion and including a lead portion drawn from the internal electrode, a side margin portion adjacent to the capacitive portion and not including a lead portion, and a cover layer. Prior to firing, the binder may be removed from the pre-fired element body. In this case, binder removal and firing may be performed consecutively using the same firing apparatus.

[0098] The conditions for removing the binder and firing may be appropriately set in consideration of the volatilization temperature and content of the binder, the sinterability of the dielectric green sheet composition powder, and the heat resistance and oxidation resistance of the metals contained in the internal electrode pattern and the lead pattern. Examples of conditions for removing the binder include the use of nitrogen (N ２ ) atmosphere at a temperature of 200°C to 500°C for 5 hours to 20 hours.

[0099] External electrodes can also be formed on the element body during firing. In this case, after removing the binder from the element body before firing, a conductive paste is applied to the lead surface of the element body during firing, which has a lead pattern on its surface. Methods for applying the conductive paste include printing and dipping. Then, by completing the firing of the element body during firing, the element body is obtained and external electrodes in which the conductive paste is sintered can be produced at the same time.

[0100] When external electrodes are provided, the firing conditions are, for example, nitrogen (N ２ ) and hydrogen (H ２ ) and water vapor (H ２ In a reducing atmosphere containing a mixture of SiO2 and SiO2, the mixture is held at 800°C to 1000°C for 10 minutes to 1 hour, and then fired at 1000°C to 1400°C for 10 minutes to 2 hours. By holding the temperature during firing, a multilayer ceramic capacitor with a large capacitance can be obtained.

[0101] After firing, nitrogen (N ２ Alternatively, a re-oxidation treatment may be performed in which the pressure-bonded body is kept at 600° C. to 1000° C. in a 1000° C. gas atmosphere or a low-oxygen atmosphere. Note that instead of dividing the pressure-bonded body into individual pieces prior to firing and firing the resulting unfired bodies, the pressure-bonded body may be fired without being divided into individual pieces, and if necessary, a re-oxidation treatment may be performed, and then the body may be divided into individual pieces to obtain a plurality of bodies.

[0102] [Formation of External Electrodes] When external electrodes are formed on the fabricated element body, a conductive paste is applied to the lead-out surface of the element body and then baked. This forms external electrodes on the element body, resulting in a multilayer ceramic capacitor. Methods for applying the conductive paste include printing and dipping. When external electrodes have multiple layers, a plating layer or the like may be provided on the surface. Examples of plating layers include a Ni plating layer, a Sn plating layer, and a Cu plating layer, and the external electrodes may be a laminate in which multiple plating layers are stacked.

[0103] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0104] For example, in the above-described embodiment, a multilayer ceramic capacitor has been exemplified as a ceramic electronic component according to the present invention, but the ceramic electronic component according to the present invention is not limited to a multilayer ceramic capacitor, and any electronic component having an element body including a capacitive portion in which a plurality of dielectric layers and a plurality of internal electrode layers are laminated is included in the technical scope of the present invention.

[0105] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0106] Examples 1 to 4 Preparation of Internal Electrode Paste Internal electrode pastes containing nickel (Ni) and carbon nanotubes were prepared. The carbon nanotube content was adjusted to be slightly higher than the value in Table 1, taking into account weight loss during firing, so that the value after firing would be the value shown in Table 1. In Table 1, the carbon nanotube content is shown as the mass percentage (mass%) of carbon nanotubes relative to the total mass of Ni and carbon nanotubes.

[0107] The internal electrode paste was prepared by mixing Ni, carbon nanotubes, and a vehicle in a triple roll mill.

[0108] [Formation of Internal Electrode Pattern and Lead Pattern] A dielectric green sheet was prepared, and the internal electrode paste prepared above was printed on the surface of the green sheet to form an internal electrode pattern. The lead pattern was also printed using the internal electrode paste at the same time as printing the internal electrode pattern.

[0109] [Preparation of a Compressed Body] Thirteen dielectric green sheets on which internal electrode patterns and lead patterns were formed were laminated on a previously prepared cover layer, and another cover layer was laminated on top of that. Subsequently, the laminate was pressed at a pressure of about 190 MPa while being heated to be compressed, thereby obtaining a compressed body which was an assembly of pre-fired elements including an unfired capacitance part.

[0110] [Fabrication of Multilayer Ceramic Capacitor] The resulting pressed body was cut into individual pieces to obtain a pre-fired element body, which was then heated to 300°C in a nitrogen atmosphere to remove the binder. The lead surface of the element body during firing, on which the lead pattern was drawn, was immersed in a conductive paste containing nickel to form a precursor for the external electrodes. Next, the element body during firing on which the precursor for the external electrodes had been formed was held at 800°C for 30 minutes in a so-called reducing-steam atmosphere, in which water vapor was introduced into a reducing gas containing hydrogen in nitrogen, and then fired at 1200°C for 2 hours. During the temperature decrease, it was held at 700°C in a nitrogen atmosphere for 1 hour, and then cooled to near room temperature to obtain a multilayer ceramic capacitor.

[0111] The obtained multilayer ceramic capacitor had a roughly rectangular parallelepiped shape with a plane perpendicular to the lamination direction of the element body measuring 1.0 mm x 0.5 mm, and the thickness of the dielectric layer was 0.5 μm.

[0112] [Preparation of dielectric constant measurement sample] A pressure-bonded body, which is an assembly of pre-fired elements, was prepared using the same method as for preparing the multilayer ceramic capacitor. The obtained pressure-bonded body was cut into pieces of the size of the measurement sample, and a pre-fired measurement sample was obtained. Next, a sintered body of the measurement sample was obtained using the same process and conditions as for preparing the multilayer ceramic capacitor, except that no external electrodes were formed. A conductive paste was printed on the top surface of the obtained sintered body of the measurement sample to form a pair of comb-shaped measurement electrodes.

[0113] Comparative Example 1 A multilayer ceramic capacitor was produced in the same manner as in Example 1, except that the internal electrode paste did not contain carbon nanotubes, and a dielectric constant measurement sample was produced in the same manner as in Example 1.

[0114] Comparative Examples 2 and 3 Multilayer ceramic capacitors were fabricated in the same manner as in Example 1, except that the content of carbon nanotubes relative to the total mass of Ni and carbon nanotubes in the internal electrode paste was set as shown in Table 1.

[0115] Example 5 A multilayer ceramic capacitor was fabricated in the same manner as in Example 1, except that the internal electrode paste used had a carbon nanotube content of 7 mass % relative to the total mass of Ni and carbon nanotubes, and the element body in the middle of firing, on which the precursors of the external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1150°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also fabricated in the same manner as in Example 1.

[0116] Example 6 A multilayer ceramic capacitor was fabricated in the same manner as in Example 1, except that the internal electrode paste used had a carbon nanotube content of 7 mass % relative to the total mass of Ni and carbon nanotubes, and the element body in the middle of firing, on which the precursors of the external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1250°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also fabricated in the same manner as in Example 1.

[0117] Comparative Example 4 A multilayer ceramic capacitor was produced in the same manner as in Example 1, except that a paste for internal electrodes containing no carbon nanotubes was used, and the element body in the middle of firing, on which precursors of external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1000°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also produced in the same manner as in Example 1.

[0118] Comparative Example 5 A multilayer ceramic capacitor was produced in the same manner as in Example 1, except that the internal electrode paste used had a carbon nanotube content of 7 mass % relative to the total mass of Ni and carbon nanotubes, and the element body in the middle of firing, on which the precursors of the external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1000°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also produced in the same manner as in Example 1.

[0119] Comparative Example 6 A multilayer ceramic capacitor was produced in the same manner as in Example 1, except that a paste for internal electrodes containing no carbon nanotubes was used, and the element body in the middle of firing, on which precursors of external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1150°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also produced in the same manner as in Example 1.

[0120] Comparative Example 7 A multilayer ceramic capacitor was produced in the same manner as in Example 1, except that a paste for internal electrodes containing no carbon nanotubes was used, and the element body in the middle of firing, on which precursors of external electrodes had been formed, was held at 800°C for 30 minutes, then fired at 1250°C for 2 hours, and then held at 700°C in a nitrogen atmosphere for 1 hour during the temperature drop, and then cooled to around room temperature. A dielectric constant measurement sample was also produced in the same manner as in Example 1.

[0121] <Evaluation of Multilayer Ceramic Capacitors> [Continuity Ratio of Internal Electrode Layers] The multilayer ceramic capacitors produced in Examples 1 to 6 and Comparative Examples 1 to 7 were each polished from the side to expose the internal electrode layers, and observed with a scanning electron microscope (SEM) at 5,000 to 10,000 times magnification. As shown in Figure 2, the length L0 of the observed portion was measured using a microscope scale or the like. Next, for one internal electrode layer, the lengths L1 to L4 of the electrode portions within the range of L0 were measured and totaled to calculate ΣLn / L0 to determine the continuity ratio of the layer. This was performed for 30 layers, and the average value was taken. The results are shown in Tables 1 and 2.

[0122]

[0123] [Dielectric Constant of Dielectric Layer] The dielectric constant of the dielectric layer was measured for each of the dielectric constant measurement samples prepared in Examples 2, 5, and 6, and Comparative Examples 1, and 4 to 7. The measurement was carried out at 1 kHz using an impedance analyzer, and the average value of 30 samples was taken as the dielectric constant of each example. The results are shown in Table 2.

[0124] [Young's Modulus] The Young's modulus of the element body was measured by three-point bending for each of the multilayer ceramic capacitors produced in Examples 2, 5, and 6, and Comparative Examples 1, and 4 to 7. The number of measurement samples was 30, and the average value was calculated. The results are shown in Table 2.

[0125]

[0126] <Discussion> From Table 1, it can be seen that the continuity ratio of the internal electrode layer is 45% or more when the carbon nanotube content is within the range (5% by mass or more and 15% by mass or less) of Examples 1 to 4. In Comparative Example 3 in which the carbon nanotube content is 20% by mass, the printability of the internal electrode paste is reduced, and therefore the continuity ratio of the internal electrode layer is reduced.

[0127] From Table 2, it can be seen that in Comparative Examples 4 and 5, in which the firing temperature of the element body was 1000°C, the dielectric constant of the dielectric layer was below 1000. Furthermore, in Comparative Examples 4 and 5, in which the firing temperature of the element body was 1000°C, the Young's modulus was also low at 2 GPa or less, and it can be seen that the strength of the multilayer ceramic capacitor was reduced.

[0128] Comparing Example 5 and Comparative Example 6, in which the firing temperature of the element body is 1150° C., Example 2 and Comparative Example 1, in which the firing temperature of the element body is 1200° C., and Example 6 and Comparative Example 7, in which the firing temperature of the element body is 1250° C., it is found that the multilayer ceramic capacitors of the Examples have a larger Young's modulus than the multilayer ceramic capacitors of the Comparative Examples. This means that the multilayer ceramic capacitors of the Examples contain carbon nanotubes, and the carbon nanotubes improve their strength.

[0129] According to the present invention, it is possible to realize a ceramic electronic component having a dielectric layer with a sufficient dielectric constant.

[0130] Furthermore, the ceramic electronic component of the present invention has internal electrode layers containing carbon nanotubes, and thus has internal electrode layers with a high continuity ratio.

[0131] Furthermore, the ceramic electronic component of the present invention can have improved strength by including carbon nanotubes in the internal electrode layers, thereby preventing damage to the element body even when external stress or the like is applied, and can maintain its functionality as a ceramic electronic component even when cracks occur in the capacitive section due to external stress or the like as long as the carbon nanotube fibers remain intact.

[0132] Furthermore, by including carbon nanotubes in the internal electrode layers of the ceramic electronic component of the present invention, it is possible to reduce the amount of metals such as nickel used as constituent materials of conventional internal electrode layers. This makes it possible to reduce the use of nickel, a rare metal resource, and also to reduce the mass of the resulting multilayer ceramic capacitor.

[0133] Therefore, the ceramic electronic component of the present invention has a dielectric layer with a sufficient dielectric constant, a high continuity ratio of the internal electrode layers, and high strength.Furthermore, the amount of rare metals such as nickel used can be reduced, which is very useful industrially.

[0134] REFERENCE SIGNS LIST 100 Multilayer ceramic capacitor 10 Body 11 Dielectric layer 12 Internal electrode layer 13 Cover layer 14 Capacitance region 15 Side margin 16a End margin 20a, 20b External electrodes

Claims

1. A ceramic electronic component comprising an element body including a capacitive section in which a plurality of dielectric layers, the main component of which is ceramic, and a plurality of internal electrode layers are alternately laminated, the internal electrode layers including carbon nanotubes, the dielectric constant of the dielectric layers being 1000 or more, and the continuity rate of the internal electrode layers being 45% or more.

2. The ceramic electronic component according to claim 1, wherein the internal electrode layers contain carbon nanotubes and a metal.

3. The ceramic electronic component according to claim 2, wherein the internal electrode layers are mixed layers made of carbon nanotubes and metal.

4. The ceramic electronic component according to claim 2, wherein the content of the carbon nanotubes in the internal electrode layers is 4 mass % or more and 18 mass % or less with respect to the total of the carbon nanotubes and the metal.

5. The ceramic electronic component according to claim 1, wherein the plurality of dielectric layers and the plurality of internal electrode layers each have a thickness of 1 μm or less.

6. The ceramic electronic component according to claim 1, wherein the dielectric layer is barium titanate.

7. A ceramic electronic component according to any one of claims 2 to 6, wherein the metal is Ni.

8. A method for manufacturing a ceramic electronic component, comprising: forming an internal electrode pattern including carbon nanotubes on a dielectric green sheet to form a laminate unit; stacking a plurality of the laminate units to form an unfired element body including an unsintered capacitive portion; and firing the unsintered element body at a temperature higher than 1000°C and lower than 1250°C to obtain an element body including a capacitive portion.

9. The method for producing a ceramic electronic component according to claim 8, wherein the internal electrode pattern is formed by printing.