Electroconductive material, ceramic electronic component, and method for manufacturing same

Abstract

Provided is technology that makes it possible to reduce the likelihood that plating adhesion will fail and that moisture infiltration paths will be formed in a conductor film provided to the surface of a ceramic electronic component, even when the conductor film is made thin.　In order to form, for example, external electrodes (6, 7) of a multilayer ceramic capacitor (1), there is prepared an electroconductive material containing nano-CuO particles that become metallic copper serving as an electroconductive component by being fired, a glass raw material mixture that becomes glass by being fired, and a solvent that dissolves or disperses the nano-CuO particles and the glass raw material, the glass raw material mixture containing a metal salt that is in a powder state and has a grain size of 100 nm or less, or a metal salt that is in the form of ions. The electroconductive material is applied to the surface of a ceramic element body (2) and is then fired at a temperature equal to or higher than the melting point of the glass raw material mixture, whereby the external electrodes (6, 7) are formed.

Description

Conductive material, ceramic electronic component and manufacturing method thereof

[0001] The present invention relates to a conductive material, a method for manufacturing a ceramic electronic component using the conductive material, and a ceramic electronic component obtained by the manufacturing method.

[0002] One example of a conductive material of interest to this invention is a conductor paste for terminal electrodes of multilayer ceramic components, as described in Japanese Patent Laid-Open Publication No. 2007-103845 (Patent Document 1). This conductor paste contains a conductive powder, such as copper powder, a glass powder, and an organic vehicle. By using glass powder with improved acid resistance through composition adjustment, even if the terminal electrodes of the multilayer ceramic component are thin, defects caused by penetration of a plating solution, such as a decrease in the adhesive strength of the terminal electrodes to the base body of the multilayer ceramic component and peeling of the terminal electrodes, are less likely to occur.

[0003] The assumed film thickness of the terminal electrode in the thin film state in Patent Document 1 is about 20 μm, as described in paragraph 0006. The particle size of the glass powder in the examples of Patent Document 1 is 3.3 μm, as described in paragraph 0034.

[0004] Japanese Patent Application Laid-Open No. 2007-103845

[0005] In addition to conductive metal components, terminal electrodes of multilayer ceramic components must contain glass to ensure film density and adhesion to the base body. The glass powder in the conductor paste provides this glass. The glass powder particles fuse together during firing to obtain the multilayer ceramic component.

[0006] When aiming for a thin terminal electrode, for example, a film thickness of 5 μm or less, the glass powder particles fuse together, causing the glass to be significantly exposed on the surface of the external electrode, reducing the continuity of the conductive metal distribution area. As a result, poor plating adhesion may occur during the plating process performed on the terminal electrode. Furthermore, if the glass penetrates the film on the terminal electrode in the thickness direction, the glass may dissolve in water, creating a path for moisture penetration into the terminal electrode.

[0007] Therefore, an object of the present invention is to provide a technology that can reduce the occurrence of the above-mentioned poor plating adhesion and the formation of moisture penetration paths in conductive films such as terminal electrodes provided on the surfaces of ceramic electronic components, even when the films are thinned.

[0008] In order to solve the above-mentioned technical problems, the present invention provides a conductive material for forming a conductor film that can satisfy the demand for reducing poor plating adhesion and the formation of moisture penetration paths, and a method for manufacturing a ceramic electronic component in which a conductor film formation step is carried out using this conductive material, and further provides a ceramic electronic component obtained by this manufacturing method.

[0009] The conductive material according to the present invention is for forming a conductive film by firing, and comprises nano-CuO particles that become metallic copper as a conductive component by firing, a glass raw material mixture that becomes glass by firing, and a solvent that dissolves or disperses the nano-CuO particles and the glass raw material mixture, wherein the glass raw material mixture contains a metal salt in a powder state or a metal salt in an ionic form having a particle size of 100 nm or less.

[0010] The present invention is also directed to a method for manufacturing a ceramic electronic component including a ceramic body and a conductive film provided on the surface of the ceramic body. The manufacturing method according to the present invention is characterized by comprising the steps of: applying the above-described conductive material to the surface of the ceramic body to form the conductive film; subsequently, heating and drying the glass raw material mixture contained in the conductive material; and subsequently, firing the glass raw material mixture at a temperature equal to or higher than the melting point of the glass raw material mixture to form the conductive film.

[0011] The present invention is also directed to a ceramic electronic component having a ceramic body and a conductive film provided on a surface of the ceramic body. The ceramic electronic component according to the present invention has the following features.

[0012] The conductor film includes copper and glass. When viewed in a cross section along the thickness direction of the conductor film, there are multiple glass domains made of glass that are not in contact with either the surface or the base in the cross section and are surrounded by copper. The conductor film is characterized in that the average diameter of circles surrounding the glass domains is 0.5 μm or more and 0.7 μm or less, the standard deviation of the diameters of the circles is 0.3 μm or more and 0.5 μm or less, and the ratio of the maximum diameter of the circles to the dimension of the conductor film in the thickness direction is less than 1.

[0013] According to the present invention, it is possible to obtain a ceramic electronic component having a conductive film that is less likely to cause poor plating adhesion or the formation of a moisture penetration path.

[0014] More specifically, according to the present invention, a conductive material containing nano CuO particles as a conductive component and a glass raw material mixture in a powder state or in the form of ions with a particle size of 100 nm or less is used for forming a conductive film, and the conductive material is fired at a temperature equal to or higher than the melting point of the glass raw material mixture to form a conductive film.

[0015] Therefore, even when glass melting occurs during the firing process, the copper and glass can each remain small. As a result, a conductor film is obtained in which, in a cross section along the thickness direction, the average diameter of circles surrounding the glass that are not in contact with either the surface or the base and are surrounded by metal is 0.5 μm or more and 0.7 μm or less, the standard deviation of the circle diameters is 0.3 μm or more and 0.5 μm or less, and the ratio of the maximum circle diameter to the thickness dimension of the conductor film is less than 1.

[0016] In this conductor film, the copper as the conductive component and the ceramic portion of the ceramic body are bonded by the glass, and the glass is separated from the copper and dispersed in a small, uniform domain size. This prevents moisture from penetrating through the glass portion of the conductor film surface. Furthermore, significant exposure of the glass on the conductor film surface is also suppressed, resulting in good plating adhesion.

[0017] 1 is a cross-sectional view schematically showing a multilayer ceramic capacitor 1 as a ceramic electronic component according to an embodiment of the present invention. It is a cross-sectional view schematically showing an enlarged view of a portion of a first external electrode 6 of the multilayer ceramic capacitor 1 shown in FIG. 1. It is a diagram showing the cross-sectional structure of a conductor film employed as the external electrodes 6 and 7 of the multilayer ceramic capacitor 1 shown in FIG. 1, and is a diagram showing an SEM image of a cross section of a sample of a conductor film 12 according to an example of the present invention, taken in an experimental example. It is a diagram showing an SEM image of a further enlarged portion of the conductor film 12 shown in FIG. 3. It is a diagram in which a circle EC surrounding a glass domain 13 is drawn in the SEM image shown in FIG. 4. It is a diagram showing an SEM image of a cross section of a sample of a conductor film 22 according to a comparative example, taken in an experimental example.

[0018] Referring to FIG. 1, the structure of a multilayer ceramic capacitor 1 as a ceramic electronic component according to one embodiment of the present invention will be described.

[0019] The multilayer ceramic capacitor 1 includes a ceramic body 2. The ceramic body 2 includes a plurality of stacked ceramic layers 3 and a plurality of internal electrodes 4 and 5 arranged along the interfaces between the plurality of ceramic layers 3. The internal electrodes 4 and 5 are classified into a plurality of first internal electrodes 4 and a plurality of second internal electrodes 5 arranged alternately in the stacking direction of the ceramic body 2. A first external electrode 6 and a second external electrode 7 serving as conductor films are provided on the surface of the ceramic body 2, more specifically, on each of the opposing end faces. The first external electrode 6 is electrically connected to the first internal electrode 4, and the second external electrode 7 is electrically connected to the second internal electrode 5.

[0020] The ceramic layer 3 is made of, for example, ABO ３ (A is at least one of Ba, Ca and Sr, and B is at least one of Ti and Zr) as a main component. ３ The alloy may contain at least one of Mn, Mg, Si, Y, Dy and Gd as a secondary component.

[0021] The internal electrodes 4 and 5 preferably contain, as a conductive component, a conductive metal or an alloy containing the same, for example, one selected from nickel, copper, silver, and a silver / palladium alloy.

[0022] The external electrodes 6 and 7 are formed by applying the conductive material of the present invention to the end faces of the ceramic body 2 so as to contact the respective ends of the internal electrodes 4 and 5, heating and drying the material, and then firing it.

[0023] The multilayer ceramic capacitor 1 is manufactured, for example, through the following steps. First, a ceramic slurry containing ceramic raw material powder having the above-described composition is prepared. Next, the ceramic slurry is formed into ceramic green sheets using an appropriate sheet forming method. Next, a conductive paste to become each of the internal electrodes 4 and 5 is applied by printing or the like to predetermined ceramic green sheets among the plurality of ceramic green sheets. Next, the plurality of ceramic green sheets are stacked and then pressed together to obtain a green ceramic body. Next, the green ceramic body is fired. In this firing step, the ceramic green sheets become the ceramic layers 3. Thereafter, a step of forming external electrodes 6 and 7 on the end faces of the ceramic body 2 is carried out.

[0024] The conductive material for forming the external electrodes 6 and 7 contains nano-CuO particles that become metallic copper as a conductive component when fired, a glass raw material mixture that becomes glass when fired, and a solvent that dissolves or disperses the nano-CuO particles and the glass raw material mixture, and the glass raw material mixture is characterized in that it contains metal salts that reach a temperature above their melting point during firing and that are in the form of powder or ions with a particle size of 100 nm or less.

[0025] Such a conductive material is initially in a sol state and is applied to the surface of the ceramic body 2, more specifically to each of the opposing end faces. It is then heated and dried to form a gel, and then fired at a temperature equal to or higher than the melting point of the metal salt contained in the glass raw material mixture, so that the glass raw material mixture is vitrified while flowing.

[0026] Fig. 2 is an enlarged schematic cross-sectional view of a portion of the first external electrode 6 of the multilayer ceramic capacitor 1 shown in Fig. 1. The second external electrode 7, although not shown in Fig. 2, has substantially the same configuration as the first external electrode 6.

[0027] 3 to 5 are SEM images of a cross section of conductive film 12 formed on substrate 11 in an experimental example described later, and because the structure of conductive film 12 is also used in external electrodes 6 and 7, these images may be used in the following description. Fig. 4 shows an SEM image of a further enlarged portion of conductive film 12 shown in Fig. 3, and Fig. 5 is a diagram in which a circle EC surrounding glass domain 13 is drawn in the SEM image shown in Fig. 4.

[0028] As a result of the firing described above, as shown in Fig. 2 for the first external electrode 6, a glass layer 14 is formed along the interface between the external electrodes 6 and 7 and the ceramic layer 3 of the ceramic body 2. In Figs. 3 to 5, the glass layer 14 is the portion extending along the interface between the substrate 11 and the conductor film 12. In Figs. 3 to 5, the glass layer 14 appears as a blackish portion.

[0029] 2 , the glass layer 14 provides a strong bond between the copper contained in the external electrodes 6 and 7 and the ceramic body 2. As described above, the firing temperature is set to be equal to or higher than the melting point of the metal salt contained in the glass raw material mixture, which promotes wetting of the glass contained in the external electrodes 6 and 7 onto the base surface 15 and densification.

[0030] 3 to 5 show multiple glass domains 13 that appear as darker regions in conductor film 12. When viewing a cross section of conductor film 12 along the thickness direction, these glass domains 13 are not in contact with either surface 16 or base surface 15 of conductor film 12 and are surrounded by copper 17. Glass domains 13 are distributed in small sizes without intermixing with copper 17.

[0031] 2 , the above-described structure will be explained by replacing the conductor film 12 with the external electrodes 6 and 7. When viewed in a cross section along the thickness direction of the external electrodes 6 and 7, there are multiple glass domains made of glass that are not in contact with either the surface 16 or the base surface 15 in the cross section and are surrounded by copper. These glass domains are distributed in small sizes without intermixing with the copper.

[0032] To define this more clearly, as shown in Fig. 5, the concept of a circle EC surrounding the glass domain 13 is introduced and quantified as follows: the average diameter of the surrounding circle EC is 0.5 µm or more and 0.7 µm or less, the standard deviation of the diameter of the surrounding circle EC is 0.3 µm or more and 0.5 µm or less, and the ratio of the maximum diameter of the surrounding circle EC to the dimension of the external electrodes 6 and 7 in the thickness direction is less than 1.

[0033] 2 for the first external electrode 6, a plating film 8 is formed as needed on the external electrodes 6 and 7. Although not shown in detail, the plating film 8 is composed of, for example, a Cu plating layer, an Ni plating layer thereon, and an Sn plating layer thereon.

[0034] In this way, even if the conductive material for the external electrodes 6 and 7 is fired until the copper portion and the ceramic body 2 are joined by the glass layer 14, the size of the glass domains 13 can be maintained small and uniform. This makes it difficult for glass domains that penetrate from the surfaces 16 of the external electrodes 6 and 7 to the substrate surface 15 to be formed. This makes it possible to suppress the penetration of moisture from the glass portions on the surfaces of the external electrodes 6 and 7. Furthermore, significant exposure of the glass on the surfaces of the external electrodes 6 and 7 is suppressed, ensuring good plating adhesion.

[0035] It is believed that the reason why the external electrodes 6 and 7 having the above-mentioned advantages were obtained is because the conductive material according to the present invention was used and the conductive material was fired according to the manufacturing method according to the present invention. This is because the conductive material contains nano CuO particles as a conductive component and also contains a powdered metal salt or ionic metal salt with a particle size of 100 nm or less as a glass raw material mixture, so that even if glass particles are fused together by firing at a temperature equal to or higher than the melting point of the glass raw material mixture, the glass domains can be maintained small and uniform.

[0036] The conductive material according to the present invention is also characterized by its ability to form thin conductive films. For example, the thickness of the external electrodes 6 and 7 can be set to 2.4 μm or more and 4.6 μm or less, as will be seen from the experimental examples described below.

[0037] The metal salt contained in the glass raw material mixture contained in the conductive material for forming the external electrodes 6 and 7 includes, for example, either a metal carboxylate or a metal nitrate.

[0038] The glass contained in the external electrodes 6 and 7 is, for example, SiO ２ and B ２ O ３ and an oxide of at least one of an alkali metal and an alkaline earth metal.

[0039] The weight ratio of the content of the glass raw material mixture to the content of the nano CuO particles as a conductive component contained in the conductive material for forming the external electrodes 6 and 7 is preferably 0.13 or more and 0.57 or less, converted into the weight of the nano CuO particles after metal copperization and the weight of the glass raw material mixture after vitrification.

[0040] The conductive material for forming the external electrodes 6 and 7 may contain an organic binder to adjust viscosity, etc. Hydroxypropyl cellulose, for example, is advantageously used as the organic binder.

[0041] While the present invention has been described above in relation to the external electrodes of a multilayer ceramic capacitor, the present invention can also be applied to ceramic electronic components other than multilayer ceramic capacitors, as long as the ceramic electronic component includes a ceramic body and a conductive film provided on the surface of the ceramic body.

[0042] Next, an example of an experiment carried out to confirm the effects of the present invention will be described.

[0043] [Example] <Preparation of Conductive Material> A conductive material in a sol state was prepared containing the following (1) to (7): (1) 50 nm diameter nanosilica surface-treated with methacrylsilane ("Admanano" manufactured by Admatechs): 1.5 mass%, (2) boric acid: 0.92 mass%, (3) lithium nitrate (melting point: 260°C): 0.48 mass%, (4) sodium nitrate (melting point: 306°C): 0.66 mass%, (5) 50 nm diameter nano CuO particles: 27.60 mass%, (6) hydroxypropyl cellulose (2.0 to 2.9 @ 20°C / 2% aqueous solution): 11.60 mass%, (7) diethylene glycol monoethyl ether: 43.80 mass%.

[0044] The above (1) to (4) are glass raw materials that become glass when fired. (5) is nano CuO particles that become metallic copper as a conductive component when fired. (6) is an organic binder. (7) is a solvent.

[0045] <Coating and baking> The conductive material was coated on a barium titanate substrate using a doctor blade with a clearance of 50 μm, and then dried at 150° C. for 30 minutes to form a gel. ２ The mixture was baked in an atmosphere at a temperature of 780° C., which is higher than the melting points of the above (3) and (4), to obtain a conductive film sample.

[0046] <Structural analysis of conductive film> Conductive film samples were embedded in resin, polished, and cross-sectioned, and then observed using an FE-SEM (JSM-6335F manufactured by JEOL Ltd.) under the following conditions: Observation pretreatment: Au+Pd sputtering, Magnification: ×2000, Acceleration voltage: 5 kV, WD: 15 to 18 mm.

[0047] Fig. 3 is an SEM image of a cross section of a sample of the conductive film 12 according to the example. Fig. 4 is an SEM image of a further enlarged portion of the conductive film 12 shown in Fig. 3.

[0048] 3 and 4, the dark portion of the conductor film 12 extending along the substrate 11 is the glass layer 14. As can be seen from Fig. 3, it was confirmed that the glass layer 14 was wet and spread and formed between the conductor film 12 and the substrate 11 over more than half of the width of the obtained image.

[0049] Next, using image analysis software (Mitani Shoji Co., Ltd.: WinROOF2021), the film thickness of the conductor film 12 was measured from the obtained image, and as shown in Figure 5, circles EC were drawn surrounding the glass domains 13 that were not in contact with the surface 16 or the base surface 15 in the cross section of the conductor film 12 as a fired film and were surrounded by copper 17. The maximum diameter, average diameter, and standard deviation of the drawn surrounding circles EC were determined, and the maximum diameter / film thickness ratio was calculated. These operations were performed for each field of view, for a total of six fields of view. The results are shown in Table 1.

[0050]

[0051] [Comparative Example] <Preparation of Conductive Material> A conductive material having the following composition was prepared using a roll mill: Cu powder (average particle size 4 μm, flake shape): 100 parts by mass, Glass powder (average particle size 3.3 μm): 10 parts by mass, and 40 parts by mass of a vehicle in which an acrylic resin binder was dissolved in terpineol.

[0052] <Coating and baking> After coating the conductive material in the same manner as in the example, the conductive material was baked in a nitrogen atmosphere containing 5 ppm of oxygen. ２ The mixture was fired at a temperature of 860° C. in an atmosphere to obtain a conductive film sample.

[0053] <Structural Analysis of Conductive Film> Structural analysis of the conductive film sample was carried out in the same manner as in the example.

[0054] FIG. 6 is an SEM image of a cross section of a sample of the conductor film 22 according to the comparative example.

[0055] 6, the dark portion of the conductor film 22 extending along the substrate 21 is the glass layer 23. As can be seen from Fig. 6, it was confirmed that the glass layer 23 was wet and spread and formed between the conductor film 22 and the substrate 21 over more than half of the width of the obtained image.

[0056] As in the case of the examples, the maximum diameter, average diameter, and standard deviation of the encircling circle of the glass domain 24 were determined, and the film thickness was also determined, and the maximum diameter / film thickness ratio was calculated. The results are shown in Table 2.

[0057]

[0058] [Discussion] Table 3 below shows a comparison between the distribution ranges of the maximum diameter, average diameter, standard deviation, film thickness, and maximum diameter / film thickness of the enclosing circle EC of glass domain 13 in the examples shown in Table 1 and the distribution ranges of the maximum diameter, average diameter, standard deviation, film thickness, and maximum diameter / film thickness of the enclosing circle of glass domain 24 in the comparative examples shown in Table 2. In Table 3, each value is rounded to one decimal place.

[0059]

[0060] In Table 3, first, comparing the film thickness, the film thickness is 2.4 μm or more and 4.6 μm or less in the Example, and 12.5 μm or more and 20.3 μm or less in the Comparative Example, which shows that the film thickness can be made overwhelmingly thinner in the Example than in the Comparative Example. This can also be confirmed by comparing Figure 3 and Figure 6, which are displayed on the same scale.

[0061] Furthermore, as shown in Table 3, in the Examples, the average diameter was 0.5 to 0.7 μm and the standard deviation was 0.3 to 0.5 μm, which is particularly comparable to the average diameter of 1.9 to 3.0 μm and the standard deviation of 1.3 to 3.8 μm in the Comparative Examples. It can be confirmed that the sizes of the glass domains 13 are small and uniform.

[0062] In the examples, the maximum diameter / film thickness is less than 1, i.e., 0.3 to 0.6, so it can be determined that glass domains penetrating from the surface 16 of the conductor film 12 to the base surface 15 are unlikely to be generated.

[0063] In the comparative examples, the average diameter of the glass domain surrounding circle was 1.9 to 3.0 μm, with a standard deviation of 1.3 to 3.8 μm, and it can be seen that the glass domains were largely irregular compared with the results of the examples.

[0064] In addition, in the comparative example, there was more than one field of view, with the maximum diameter / film thickness being 0.3 to 1.1, so it can be determined that there is a high possibility that a glass domain will be generated that penetrates from the surface of the conductor film 22 to the underlying surface.

[0065] From the above, it is presumed that in the comparative example, the CuO particles and glass raw material particles in the conductive material are large, and when firing is continued until Cu and substrate 21 are bonded, fusion of the glass particles occurs, and the glass domains become larger. This is presumed to form glass domains that penetrate from the surface of conductive film 22 to the base surface, which may cause the plating solution to penetrate into conductive film 22. It is also presumed that the glass domains become larger on the surface of conductive film 22, which may cause poor plating adhesion.

[0066] In contrast, in the examples, the Cu in the conductive material is in the form of nano-CuO particles, and the glass raw material mixture contains a powdered metal salt with a particle size of 100 nm or less or a metal salt in the form of ions. This allows the glass domains 13 to remain small and uniform even when glass is fused to itself. This prevents the formation of glass domains that penetrate from the surface 16 of the conductor film 12 to the base surface 15, thereby preventing the penetration of the plating solution into the conductor film 12. Furthermore, significant exposure of the glass on the surface 16 of the conductor film 12 is also prevented, resulting in good plating adhesion.

[0067] The embodiments of the present invention include the following:

[0068] <1> A conductive material for forming a conductor film provided on a surface of a ceramic body by firing, the conductive material comprising: nano-CuO particles that become metallic copper as a conductive component by firing; a glass raw material mixture that becomes glass by firing; and a solvent for dissolving or dispersing the nano-CuO particles and the glass raw material mixture, wherein the glass raw material mixture contains a metal salt in a powder state or a metal salt in an ionic form having a particle size of 100 nm or less.

[0069] <2> The conductive material according to <1>, wherein the metal salt includes either a metal carboxylate or a metal nitrate.

[0070] <3> The conductive material according to <1> or <2>, which is used to form an external electrode of a multilayer ceramic capacitor.

[0071] <4> The conductive material according to any one of <1> to <3>, wherein a weight ratio of the content of the glass raw material mixture to the content of the nano CuO particles is 0.13 or more and 0.57 or less, calculated as a weight of the nano CuO particles after metal copperization and a weight of the glass raw material mixture after vitrification.

[0072] <5> The conductive material according to any one of <1> to <4>, wherein the solvent contains diethylene glycol monoethyl ether.

[0073] <6> The conductive material according to any one of <1> to <5>, further comprising an organic binder.

[0074] <7> The conductive material according to <6>, wherein the organic binder contains hydroxypropyl cellulose.

[0075] <8> A method for manufacturing a ceramic electronic component including a ceramic body and a conductive film provided on a surface of the ceramic body, the method comprising: applying the conductive material according to any one of <1> to <7> to a surface of the ceramic body to form the conductive film; subsequently, heating and drying a glass raw material mixture contained in the conductive material; and subsequently, firing the glass raw material mixture at a temperature equal to or higher than the melting point of the glass raw material mixture to form the conductive film.

[0076] <9> A ceramic electronic component comprising: a ceramic body; and a conductor film provided on a surface of the ceramic body, wherein the conductor film contains copper and glass; when viewed in a cross section along a thickness direction of the conductor film, there are a plurality of glass domains made of the glass that are not in contact with either the surface or a substrate in the cross section and are surrounded by the copper; the average diameter of circles surrounding the glass domains is 0.5 μm or more and 0.7 μm or less, the standard deviation of the diameters of the circles is 0.3 μm or more and 0.5 μm or less, and the ratio of the maximum diameter of the circles to the dimension of the conductor film in the thickness direction is less than 1.

[0077] <10> The ceramic electronic component according to <9>, wherein the conductor film has a thickness dimension of 2.4 μm or more and 4.6 μm or less.

[0078] <11> The glass is SiO ２ and B ２ O ３ and an oxide of at least one of an alkali metal and an alkaline earth metal.

[0079] <12> The ceramic electronic component according to any one of <9> to <11>, further comprising a plating film formed on the conductor film.

[0080] <13> The ceramic electronic component according to any one of <9> to <12>, wherein the ceramic body includes a plurality of laminated ceramic layers and a plurality of internal electrodes respectively arranged along a plurality of interfaces between the ceramic layers, and the conductor film is provided on a surface of the ceramic body and provides a plurality of external electrodes electrically connected to the internal electrodes, thereby constituting a multilayer ceramic capacitor.

[0081] REFERENCE SIGNS LIST 1 Multilayer ceramic capacitor 2 Ceramic element body 3 Ceramic layer 4, 5 Internal electrodes 6, 7 External electrodes 8 Plating film 11 Substrate 12 Conductor film 13 Glass domain 14 Glass layer 15 Base surface 16 Surface 17 Copper EC Enclosing circle

Claims

1. A conductive material for forming a conductor film provided on the surface of a ceramic green body by firing, comprising nano CuO particles that become metallic copper as a conductive component when fired, a glass raw material mixture that becomes glass when fired, and a solvent that dissolves or disperses the nano CuO particles and the glass raw material mixture, wherein the glass raw material mixture contains a metal salt in the form of a powder having a particle size of 100 nm or less or a metal salt in ionic form, a conductive material.

2. The conductive material according to claim 1, wherein the metal salt contains either a metal carboxylate or a metal nitrate.

3. The conductive material according to claim 1, which is used for forming an external electrode of a multilayer ceramic capacitor.

4. The weight ratio of the content of the glass raw material mixture to the content of the nano CuO particles is 0.13 or more and 0.57 or less when converted to the weight after the nano CuO particles are converted to metallic copper and the weight after the glass raw material mixture is vitrified. The conductive material according to claim 1.

5. The conductive material according to claim 1, wherein the solvent contains diethylene glycol monoethyl ether.

6. Furthermore, the conductive material according to claim 1, which contains an organic binder.

7. The conductive material according to claim 6, wherein the organic binder contains hydroxypropyl cellulose.

8. A method for manufacturing a ceramic electronic component, comprising a ceramic green body and a conductor film provided on the surface of the ceramic green body, wherein, in order to form the conductor film, a step of applying the conductive material according to any one of claims 1 to 5 to the surface of the ceramic green body, then a step of heating and drying the glass raw material mixture contained in the conductive material, and then a step of firing at a temperature equal to or higher than the melting point of the glass raw material mixture to form the conductor film, a method for manufacturing a ceramic electronic component.

9. A ceramic green body, and a conductor film provided on the surface of the ceramic green body, comprising, wherein the conductor film contains copper and glass. When looking at a cross-section along the thickness direction of the conductor film, there are a plurality of glass domains made of the glass that are not in contact with either the surface or the bottom surface in the cross-section and are surrounded by the copper. The average of the diameters of the circles surrounding the glass domains is 0.5 μm or more and 0.7 μm or less, the standard deviation of the diameters of the circles is 0.3 μm or more and 0.5 μm or less, and the ratio of the maximum diameter of the circle to the thickness direction dimension of the conductor film is less than 1. Ceramic electronic component.

10. The ceramic electronic component according to claim 9, wherein the thickness direction dimension of the conductor film is 2.4 μm or more and 4.6 μm or less.

11. The glass contains SiO 2 and B 2 O 3 and includes at least one oxide of an alkali metal and an alkaline earth metal, the ceramic electronic component according to claim 9.

12. The ceramic electronic component according to claim 9, further comprising a plating film formed on the conductor film.

13. The ceramic body includes a plurality of laminated ceramic layers and a plurality of internal electrodes respectively arranged along a plurality of interfaces between the ceramic layers. The conductor film is a plurality of external electrodes provided on the surface of the ceramic body and electrically connected to the internal electrodes. Constituting a multilayer ceramic capacitor. The ceramic electronic component according to claim 9.