JP4653647B2 - Ceramic capacitor, ceramic capacitor manufacturing method, and ceramic green sheet - Google Patents

Description

The present invention relates to a ceramic capacitor, a ceramic capacitor manufacturing method, and a ceramic green sheet that can be manufactured through a simple manufacturing process and have high productivity.

Multilayer electronic components, such as ceramic capacitors, are provided between a large number of dielectric layers, internal electrodes that are arranged between these dielectric layers, and that are alternately exposed on opposite side surfaces, and on opposite side surfaces. And a pair of external electrodes.

A dielectric layer and internal electrodes of a conventional multilayer ceramic capacitor are generally manufactured through the following steps. After adding a plasticizer, a dispersant, etc. to a solution in which a binder resin such as polyvinyl butyral resin or poly (meth) acrylic acid ester resin is dissolved in an organic solvent, add ceramic raw material powder, and uniformly mix with a ball mill or the like, A ceramic slurry composition having a constant viscosity after defoaming is obtained. This slurry composition is cast-molded on a support surface such as a polyethylene terephthalate film or a SUS plate which has been subjected to a release treatment using a doctor blade, a reverse roll coater or the like. This is heated to remove volatile components such as a solvent, and then peeled off from the support to obtain a ceramic green sheet.

Next, a plurality of sheets obtained by alternately applying a conductive paste serving as an internal electrode on the obtained ceramic green sheet by screen printing or the like are stacked and heat-pressed to obtain a laminate. A multilayer ceramic capacitor through a process of thermally decomposing and removing the binder component contained in the laminate, so-called degreasing treatment, and sintering an external electrode on the end face of the ceramic fired product obtained by firing. Is obtained.
As described above, the production of the multilayer ceramic capacitor requires a very complicated and complicated process.

In recent years, there has been a demand for miniaturization and large capacity of multilayer ceramic capacitors, and thinning and multilayering of dielectrics and internal electrodes have been promoted.
However, in such a multilayer ceramic capacitor, the level difference generated between the region where the electrode layer is formed in a predetermined pattern on the surface of the ceramic green sheet and the region where the electrode layer is not formed accumulates. In the step of pressure-bonding the laminate, there has been a problem that pressure cannot be uniformly applied and delamination called delamination occurs.

On the other hand, for example, Patent Document 1 discusses a method for eliminating a step by printing a dielectric paste in a region where an electrode layer is not formed. However, this method has a problem that the manufacturing process and structure of the ceramic capacitor are further complicated.
JP 2005-171177 A

The present invention has been made in view of the above situation, and an object thereof is to provide a ceramic capacitor, a method for manufacturing a ceramic capacitor, and a ceramic green sheet that can be manufactured through a simple manufacturing process and have high productivity.

The present invention is a ceramic capacitor comprising a sheet-like ceramic sintered body containing nanofibers or nanotubes having magnetism and conductivity, and an external electrode formed on the sheet surface of the ceramic sintered body, In the ceramic sintered body, the nanofibers or nanotubes having magnetism and conductivity are oriented in a direction perpendicular to the sheet surface on which the external electrode is formed, and at least a part of the magnetism and conductivity is provided. The nanofiber or nanotube having a property is a ceramic capacitor in which one end is in contact with the external electrode.

As a result of intensive studies, the present inventors have found that the ceramic sintered body is composed of a sheet-shaped ceramic sintered body and an external electrode formed on the sheet surface of the ceramic sintered body. The nanofibers or nanotubes having magnetic properties and conductivity are oriented in the direction perpendicular to the sheet surface on which the external electrodes are formed, and at least one One part of the nanofiber or nanotube having magnetism and conductivity in contact with the external electrode can obtain a ceramic capacitor in which the nanofiber or nanotube having magnetism and conductivity functions as an internal electrode. I found out that I can do it. This eliminates the need to separately manufacture and laminate the dielectric and internal electrodes in the ceramic capacitor manufacturing process, simplifying the manufacturing process, improving productivity, and reducing delamination. The inventors have found that a ceramic capacitor that does not occur can be produced, and have completed the present invention.

An example of the ceramic capacitor of the present invention is shown in FIG.
FIG. 1a is a cross-sectional view showing a state before voltage application of the ceramic capacitor of the present invention, and FIG. 1b is a cross-sectional view showing a state after voltage application of the ceramic capacitor of the present invention.
As shown in FIG. 1 a, the ceramic capacitor 1 includes a ceramic sintered body 2 and an external electrode 3 formed on the sheet surface of the ceramic sintered body 2. The ceramic sintered body 2 includes nanofibers 4 having magnetism and conductivity, and the nanofibers 4 having magnetism and conductivity are oriented in a direction perpendicular to the sheet surface on which the external electrode 2 is formed. At least a part of the nanofiber 4 having magnetism and conductivity is in contact with the external electrode 2 at one end. The nanofibers 4 having magnetism and conductivity form a nanofiber chain portion 4a and are electrically connected.
When a voltage is applied to such a ceramic capacitor 1, a negative electrode 3a formed on the upper surface of the sheet and a positive electrode 3b formed on the lower surface of the sheet are electrically connected via the ceramic sintered body 2 as shown in FIG. Connected.

The ceramic capacitor of the present invention comprises a sheet-like ceramic sintered body and an external electrode formed on the sheet surface of the ceramic sintered body.

The ceramic sintered body contains nanofibers or nanotubes having magnetism and conductivity.
In the present specification, the nanofibers having magnetism and conductivity mean ultrafine fibers made of a material having magnetism and conductivity. The nanotube having magnetism and conductivity means an ultrafine hollow fiber made of a material having magnetism and conductivity.

The magnetic and conductive material constituting the magnetic and conductive nanofiber or nanotube is not particularly limited. For example, nickel, aluminum, iron, cobalt, chromium, ferrite, magnesium, palladium, zirconium, or The alloy, the compound, etc. are mentioned.
By using such nanofibers or nanotubes, in the ceramic capacitor of the present invention, the above-mentioned nanofibers or nanotubes having magnetism and conductivity can be used as internal electrodes, and a capacitor having excellent electrical characteristics can be obtained. .

In the nanofiber or nanotube having magnetism and conductivity, the preferable lower limit of the fiber length or the tube length is 1 μm, and the preferable upper limit is 100 μm. When the thickness is less than 1 μm, the nanofibers or nanotubes having magnetism and conductivity may not be electrically connected to each other. When the thickness exceeds 100 μm, when the magnetic and conductive nanofibers or nanotubes are oriented in the direction perpendicular to the sheet surface, the magnetic and conductive nanofibers or nanotubes may be entangled and not sufficiently aligned.

The nanofibers or nanotubes having magnetism and conductivity preferably have a high aspect ratio structure, and the preferred lower limit of the aspect ratio (fiber diameter or tube diameter / fiber length or tube length) is 20. If the aspect ratio is less than 20, sufficient anisotropic conductivity may not be obtained, and nanofibers or nanotubes having magnetism and conductivity may not function as internal electrodes.

In the ceramic sintered body, the nanofibers or nanotubes having magnetism and conductivity are oriented in a direction perpendicular to the sheet surface on which the external electrode is formed, and at least a part of the magnetism and conductivity is obtained. One end of the nanofiber or nanotube having a contact with the external electrode.
By being oriented in this way, in the ceramic capacitor of the present invention, the above-described nanofibers or nanotubes having magnetism and conductivity can be used as internal electrodes, and a ceramic capacitor having excellent electrical characteristics can be obtained.

In the ceramic sintered body, the magnetic and conductive nanofibers or nanotubes preferably have a nanofiber chain part or a nanotube chain part.
In addition, the said nanofiber chain part or the nanotube chain part means the part which the nanofiber or nanotube which has the said magnetism and electroconductivity is electrically connected.
By having such a chain portion, in the ceramic capacitor of the present invention, the above-described magnetic and conductive nanofibers or nanotubes are electrically connected to each other to form an internal electrode, thereby having excellent electrical characteristics. A ceramic capacitor is obtained.

The method for producing the magnetic and conductive nanofibers is not particularly limited. For example, the nanofiber is produced by immersing a magnetic and conductive material in an alkaline solution and raising the temperature from 20 ° C. to 200 ° C. The method of doing is mentioned.

The method for producing the above-mentioned nanotubes having magnetism and conductivity is not particularly limited. For example, the ultrafine fiber made of an organic material is immersed in an electroless plating bath to be plated with a material having magnetism and conductivity. The organic fiber covered with the obtained magnetic and conductive material is immersed in an alkaline solution to dissolve the organic fiber.

The ceramic sintered body can be obtained, for example, by molding a ceramic paste in which ceramic powder is dispersed in an organic binder, followed by firing and degreasing.
The ceramic powder is not particularly limited as long as it exhibits dielectric properties, and various compounds that become composite oxides or oxides, such as carbonates, nitrates, hydroxides, organometallic compounds, or the like, or Mixed powders can be used. Specifically, powders, such as barium titanate, magnesium carbonate, manganese oxide, are mentioned, for example. These ceramic powders may be used alone or in combination of two or more.

The external electrode is formed on the sheet surface of the ceramic sintered body.
It does not specifically limit as said external electrode, For example, it can form using the paste for external electrodes containing conductor powder, an organic binder, etc.

The conductor powder is not particularly limited as long as it exhibits conductivity, and examples thereof include fine particles made of nickel, palladium, platinum, gold, silver, copper, or alloys thereof. These conductive powders may be used alone or in combination of two or more.

Although it does not specifically limit as said organic binder, For example, cellulose derivatives, such as ethyl cellulose, an acrylic resin, polyvinyl butyral resin, etc. are mentioned. These organic binders may be used alone or in combination of two or more.

The method for producing the ceramic capacitor of the present invention is not particularly limited. For example, a composition for a ceramic green sheet containing nanofibers or nanotubes having magnetism and conductivity, ceramic powder, and an organic binder is formed into a sheet shape. A sheet molded body by applying a magnetic field to the sheet molded body to orient the nanofibers or nanotubes having magnetism and conductivity in a direction perpendicular to the sheet surface of the sheet molded body. A ceramic capacitor comprising a step of producing a green sheet, a step of firing the ceramic green sheet to produce a sheet-like ceramic sintered body, and a step of forming an external electrode on a sheet surface of the ceramic sintered body Manufacturing methods can be used. Such a method of manufacturing a ceramic capacitor is also one aspect of the present invention.
By such a manufacturing method, a ceramic capacitor containing magnetic and conductive nanofibers or nanotubes oriented in a direction perpendicular to the sheet surface of the ceramic sintered body can be obtained, and has the above magnetic and conductive properties. Since the nanofiber or the nanotube can be used as an internal electrode in the ceramic capacitor, the manufacturing process of the ceramic capacitor can be simplified and the productivity can be improved.

Specifically, the method for producing a ceramic capacitor of the present invention was obtained by mixing raw materials containing nanofibers or nanotubes having magnetism and conductivity, ceramic powder, an organic binder, and an organic solvent, for example. The ceramic green sheet composition is coated on a support such as polyethylene terephthalate, and formed into a sheet shape to produce a sheet molded body. By applying a magnetic field to the sheet molded body, the magnetic and conductive properties are improved. A ceramic green sheet is produced by orienting the nanofibers or nanotubes that are included in a direction perpendicular to the sheet surface of the sheet molded article and then drying. Alternatively, a composition for a ceramic green sheet containing nanofibers or nanotubes having magnetism and conductivity, ceramic powder, and a thermoplastic binder is formed into a sheet shape, and heat is applied to the obtained sheet, thereby forming a sheet. A magnetic field is applied in a state where the viscosity of the ceramic green sheet is lowered to orient the nanofibers or nanotubes having magnetism and conductivity in a direction perpendicular to the sheet surface of the ceramic green sheet, and then cooled to produce a ceramic green sheet. Next, after performing a process of thermally decomposing organic components contained in the obtained ceramic green sheet, so-called degreasing treatment, after firing to obtain a sheet-like ceramic sintered body, a conductive paste is applied, For example, a method of forming an external electrode on the sheet surface of the ceramic sintered body by performing plating treatment and pasting conductive plates can be used.

The method for producing a ceramic capacitor of the present invention includes a step of forming a sheet green body by forming a ceramic green sheet composition into a sheet shape.
The composition for a ceramic green sheet contains the nanofibers or nanotubes having magnetic properties and conductivity, ceramic powder, and an organic binder.

In the ceramic green sheet composition, the content of the nanofibers or nanotubes having magnetism and conductivity is preferably 5 parts by weight and preferably 40 parts by weight with respect to 100 parts by weight of the ceramic powder. . If it is less than 5 parts by weight, the area functioning as the internal electrode may be insufficient, and sufficient electrical characteristics may not be obtained. When the amount exceeds 40 parts by weight, the entanglement between the magnetic and conductive nanofibers or nanotubes increases, so that it becomes difficult to disperse well, and at the same time, it is difficult to orient in the direction perpendicular to the sheet surface by a magnetic field. May be.

The ceramic powder is not particularly limited as long as it exhibits dielectric properties, and various compounds that become composite oxides or oxides, such as carbonates, nitrates, hydroxides, organometallic compounds, or the like, or Mixed powders can be used. Specifically, powders, such as barium titanate, magnesium carbonate, manganese oxide, are mentioned, for example. These ceramic powders may be used alone or in combination of two or more.

The organic binder is not particularly limited, and examples thereof include cellulose derivatives such as ethyl cellulose, acrylic resins, polyvinyl butyral resins, and the like. These organic binders may be used alone or in combination of two or more.

The ceramic green sheet composition may contain an organic solvent.
The organic solvent is not particularly limited, and examples thereof include ketones such as acetone, methyl ethyl ketone, dipropyl ketone, and diisobutyl ketone; alcohols such as methanol, ethanol, isopropanol, and butanol; aromatic hydrocarbons such as toluene and xylene; Methyl propionate, ethyl propionate, butyl propionate, methyl butanoate, ethyl butanoate, butyl butanoate, methyl pentanoate, ethyl pentanoate, butyl pentanoate, methyl hexanoate, ethyl hexanoate, butyl hexanoate, acetic acid 2 -Esters such as ethyl hexyl and 2-ethylhexyl butyrate; methyl cellosolve, ethyl cellosolve, butyl cellosolve, α-terpineol, terpinyl acetate, dihydroterpineol, dihydroterpineol acetate, Chill cellosolve acetate, butyl carbitol acetate. These organic solvents may be used independently and 2 or more types may be used together.

The ceramic green sheet composition may further contain a dispersant.
Although it does not specifically limit as said dispersing agent, For example, a fatty acid, an aliphatic amine, an alkanolamide, and phosphate ester can be used conveniently.

The fatty acid is not particularly limited, and examples thereof include saturated fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, caprylic acid, and coconut fatty acid; oleic acid, linoleic acid, linolenic acid, sorbic acid And unsaturated fatty acids such as beef tallow fatty acid and castor-cured fatty acid. Of these, lauric acid, stearic acid, oleic acid and the like are preferable.
The aliphatic amine is not particularly limited. For example, laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, alkyl (coconut) amine, alkyl (cured beef tallow) amine, alkyl (beef tallow) amine, alkyl (soybean) amine Etc.
The alkanolamide is not particularly limited, and examples thereof include coconut fatty acid diethanolamide, beef tallow fatty acid diethanolamide, lauric acid diethanolamide, and oleic acid diethanolamide.
It does not specifically limit as said phosphate ester, For example, polyoxyethylene alkyl ether phosphate ester and polyoxyethylene alkyl allyl ether phosphate ester are mentioned.

The composition for ceramic green sheets may further contain conventionally known additives such as a plasticizer, a lubricant, and an antistatic agent as long as the effects of the present invention are not impaired.

Examples of the method for forming into a sheet include a method of coating a ceramic green sheet composition on a support such as polyethylene terephthalate, a method using a molding machine, and the like.
The method for coating the ceramic green sheet composition on a support such as polyethylene terephthalate is not particularly limited. For example, a doctor blade, an extrusion coater, a wire bar coater, a screen printing machine, a gravure printing machine, etc. The method to use is mentioned.
The method using the molding machine is not particularly limited, and examples thereof include calendar molding and a method using a T die.

The method for producing a ceramic capacitor according to the present invention includes applying a magnetic field to the sheet compact to orient the nanofibers or nanotubes having magnetism and conductivity in a direction perpendicular to the sheet surface of the sheet compact. A step of producing a green sheet.

The method of applying the magnetic field is not particularly limited, and examples thereof include a method of placing on a solenoid coil to which a predetermined current and voltage are applied, a method of placing on a magnet such as a superconducting magnet and a permanent magnet, and the like. It is done.

In the step of forming a sheet green body by forming the ceramic green sheet composition into a sheet shape, when using a method of coating on a support such as the polyethylene terephthalate, after applying the magnetic field, A ceramic green sheet can be obtained by drying the sheet compact.

In the step of forming a sheet green body by forming the ceramic green sheet composition into a sheet shape, when the method using the molding machine is used, heat is applied to the molded sheet before applying the magnetic field. By adding, it is preferable to reduce the viscosity of the sheet compact. This makes it easier to orient the nanofibers or nanotubes having magnetism and conductivity in the sheet molded body in the direction perpendicular to the sheet surface of the sheet molded body.

In the step of producing a ceramic green sheet by orienting the nanofibers or nanotubes having magnetism and conductivity in a direction perpendicular to the sheet surface of the sheet molded body by applying the magnetic field, the sheet molded body comprises: The viscosity measured using a rotary viscometer (manufactured by Eiko Seiki Co., Ltd.) is preferably less than 100,000 Pa · s. When the magnetic field is applied when it is 100,000 Pa · s or more, the nanofibers or nanotubes having the magnetism and conductivity in the sheet molded body are oriented in a direction perpendicular to the sheet surface of the sheet molded body. May be difficult.

The temperature at which the viscosity is measured is not particularly limited, and heat may be applied so that the viscosity becomes less than 100,000 Pa · s, but a preferable upper limit is 90 ° C. When the temperature exceeds 90 ° C., volatilization and thermal decomposition of the sheet molded product content easily occur, and voids are generated in the sheet, so that a uniform sheet molded product may not be obtained.

In the method for producing a ceramic capacitor of the present invention, a ceramic green sheet containing the above-mentioned magnetic and conductive nanofibers or nanotubes having the above-mentioned conductivity, the above-mentioned ceramic powder, and the above-mentioned organic binder, wherein the above-mentioned magnetism and conductivity As the intermediate product, the nanofibers or nanotubes having a can be obtained as an intermediate product of a ceramic green sheet that is oriented in a direction perpendicular to the sheet surface of the ceramic green sheet.
Such a ceramic green sheet is also one aspect of the present invention.

The method for producing a ceramic capacitor of the present invention includes a step of firing the ceramic green sheet to produce a ceramic sintered body.
The method for firing the ceramic green sheet is not particularly limited. For example, first, the binder is gradually removed at 200 to 500 ° C. in an air atmosphere, and then fired at a high temperature of 950 to 1350 ° C. in a reducing atmosphere. And a method of sintering the ceramic.

The manufacturing method of the ceramic capacitor of this invention may have the process of performing double-sided grinding | polishing to the said ceramic sintered compact.
By performing such double-sided polishing, at least a part of one end of the above-mentioned nanofiber or nanotube having magnetism and conductivity is exposed on the sheet surface of the ceramic sintered body and is connected to the external electrode. It can function as an electrode.
The double-side polishing method is not particularly limited, and examples thereof include barrel polishing, buff polishing, glass polishing, belt polishing, and blast polishing.

The manufacturing method of the ceramic capacitor of this invention has the process of forming an external electrode on the sheet | seat surface of the said ceramic sintered compact.
The method for forming the external electrode is not particularly limited. For example, the external electrode is formed by applying an external electrode paste obtained by mixing the conductive powder, the organic binder, and the like, and sintering in a nitrogen atmosphere. The method of doing is mentioned.

The external electrode may be formed by applying the external electrode paste on the surface of the ceramic green sheet, and simultaneously firing and sintering the ceramic sintered body and the external electrode.

According to the present invention, in the production of a ceramic capacitor, it is not necessary to separately produce and laminate a plurality of dielectrics and internal electrodes, so that it can be produced through a simple production process, has high productivity, and A ceramic capacitor in which delamination does not occur, a method of manufacturing a ceramic capacitor, and a ceramic green sheet can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example)
(Production of magnetic nanotube)
A homogeneous aqueous solution was prepared by dissolving 1 g of 6- {2-sec-butyl-4- (4-pyridylazo) phenoxy} hexanoic acid powder in 1000 ml of a sodium hydroxide aqueous solution at pH 12. Carbon dioxide was blown into this aqueous solution for 3 hours (blowing amount: 100 ml / min) to obtain an organic fiber having a shaft diameter of 1 μm and a length of about 20 μm.

The obtained organic fiber was washed with deionized water, and an acetate buffer solution (pH 5, 0.1 mol dm ⁻³ ) in which 6 × 10 ⁻³ mass% palladium chloride and 0.6 mass% sodium chloride were dissolved. It was immersed in 500 ml. After standing at room temperature for 30 minutes, it was washed with deionized water. Subsequently, the organic fiber washed with deionized water was mixed with 1.5% by mass of nickel hypophosphite hexahydrate, 1.2% by mass of boric acid, 0.24% by mass of sodium acetate and 0.2% by mass. It was immersed in an electroless nickel plating bath having a pH of 5.5 containing 12% by mass of ammonium sulfate and allowed to stand at room temperature for 30 minutes. In addition, a pH 5.5 solution containing 4.5% by weight nickel hypophosphite hexahydrate, 1.2% by weight boric acid, 0.24% by weight sodium acetate and 0.12% by weight ammonium sulfate. After being immersed in an electrolytic plating bath and allowed to stand at room temperature for 24 hours, it was washed with deionized water to obtain organic fibers coated with metallic nickel.

The obtained organic fiber coated with nickel metal is immersed in an aqueous sodium hydroxide solution having a pH of 14 and allowed to stand at room temperature for 24 hours to dissolve the organic fiber and use a PTFE membrane filter (pore size: 0.2 μm). Filtration and washing with deionized water gave a hollow nickel tube.

(Preparation of ceramic slurry composition)
6 parts by weight of a polyvinyl butyral resin (ESREC B “BM-S”, polymerization degree 800, manufactured by Sekisui Chemical Co., Ltd.) was added to a mixed solvent of 70 parts by weight of toluene and 70 parts by weight of ethanol and dissolved by stirring. Further, 3 parts by weight of dibutyl phthalate as a plasticizer was added to this resin solution and dissolved by stirring. To the resin solution thus obtained, 20 parts by weight of the obtained nickel tube and 100 parts by weight of barium titanate (BT-01, average particle size of 0.1 μm, manufactured by Sakai Chemical Industry Co., Ltd.) as ceramic powder were added, and 48 times by a ball mill. Mixing for a time, a ceramic slurry composition was obtained.

(Production of magnetic nanotube oriented ceramic green sheet)
The obtained ceramic slurry composition was applied to a PET film so that the film thickness after drying was 150 μm after volatilizing the organic solvent at 40 ° C. for 1 hour using a vacuum oven. A ceramic green sheet is left on a DC solenoid coil (Tamagawa Seisakusho Co., Ltd.) applied with 20A and a voltage of 30V for 10 minutes, air-dried at room temperature for 1 hour, and further dried at 80 ° C. for 3 hours using a hot air dryer. Obtained.

(Production of ceramic capacitors)
The obtained ceramic green sheet was cut to a size of 5 cm square, heated to 450 ° C. at a heating rate of 3 ° C./min in a nitrogen atmosphere, held for 5 hours, and further heated at a heating rate of 5 ° C./min. The temperature was raised to 1350 ° C. and held for 10 hours to obtain a ceramic sintered body. The ceramic sintered body thus obtained was subjected to double-side polishing, and then an external electrode paste was pattern printed on both sides as shown in FIG.
Next, in a nitrogen atmosphere, the temperature was raised to 700 ° C. at a temperature raising rate of 10 ° C./min, held for 10 minutes, and then cooled to form an external electrode. Further, the formed external electrode was plated to produce a ceramic capacitor.

(Comparative example)
(Production of ceramic green sheets)
6 parts by weight of a polyvinyl butyral resin (ESREC B “BM-S”, polymerization degree 800, manufactured by Sekisui Chemical Co., Ltd.) was added to a mixed solvent of 70 parts by weight of toluene and 70 parts by weight of ethanol and dissolved by stirring. To this resin solution, 3 parts by weight of dibutyl phthalate was added as a plasticizer and dissolved by stirring. Furthermore, 100 parts by weight of barium titanate (BT-01, average particle size 0.1 μm, manufactured by Sakai Chemical Industry Co., Ltd.) as ceramic powder was added to this resin solution, and mixed with a ball mill for 48 hours to obtain a ceramic slurry composition. It was.
The obtained ceramic slurry composition was applied onto a substrate sheet on which a release layer was formed so that the thickness after drying was about 1 μm, air-dried at room temperature for 1 hour, and further heated with a hot-air dryer at 80 ° C. for 3 hours. The resulting mixture was dried at 120 ° C. for 2 hours to obtain a ceramic green sheet.

(Preparation of conductive paste)
7 parts by weight of polyvinyl butyral resin (ESREC B “BM-S”, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts by weight of α-terpineol with respect to 100 parts by weight of nickel fine particles (2020SS, manufactured by Mitsui Kinzoku Co., Ltd.) as a conductive powder And kneaded with three rolls to obtain a conductive paste. The kneading was performed by passing a roll until no aggregate (uncrushed material) was observed with an optical microscope.

(Production of ceramic capacitors)
A conductive pattern was printed on the ceramic green sheet by screen printing of the obtained conductive paste. The printing speed was about 4 m / min. The dielectric layer paste for absorbing the level difference caused by the formation of the conductive pattern is heated at 40 ° C. and stirred to volatilize excess ethanol and toluene. Screen printing was performed on the unformed part.
50 layers of the obtained green sheets on which the electrode layers were formed were laminated, cut and sintered. After polishing this, an external electrode paste was applied to both ends by the dipping method, and firing and plating were performed in the same manner as in Example to produce a ceramic capacitor.

(Evaluation)
When an electric signal was applied to the ceramic capacitor obtained in the example, a response as a capacitor was recognized.
Further, in the embodiment, since the screen printing process of the internal electrode and the stacking process of the unit composed of the ceramic green sheet and the internal electrode, which have been conventionally required, can be omitted, the ceramic capacitor is compared with the comparative example. The time required for production could be reduced by 40% or more.
Furthermore, since the ceramic capacitor obtained in the example is not a laminated body, the ceramic capacitor can be manufactured extremely efficiently without the occurrence of delamination, which has been a big problem in the conventional production efficiency. It has been found.

ADVANTAGE OF THE INVENTION According to this invention, it can manufacture through a simple manufacturing process and can provide the ceramic capacitor, the manufacturing method of a ceramic capacitor, and a ceramic green sheet with high productivity.

It is a schematic cross section which shows an example of the ceramic capacitor of this invention. It is a schematic cross section which shows an example of the ceramic capacitor of this invention. It is a schematic diagram which shows arrangement | positioning of the external electrode in the ceramic capacitor produced in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ceramic capacitor 2 Ceramic sintered body 3 External electrode 3a Negative electrode 3b Positive electrode 4 Nanofiber 4a which has magnetism and conductivity Nanofiber connection part

Claims (3)

A ceramic capacitor comprising a sheet-like ceramic sintered body containing nanofibers or nanotubes having magnetism and conductivity, and an external electrode formed on the sheet surface of the ceramic sintered body,
In the ceramic sintered body, the nanofibers or nanotubes having magnetism and conductivity are oriented in a direction perpendicular to the sheet surface on which the external electrode is formed, and at least a part of the magnetism and conductivity is provided. One end of the nanofiber or nanotube having a property is in contact with the external electrode. Forming a sheet green body by molding a composition for a ceramic green sheet containing nanofibers or nanotubes having magnetism and conductivity, ceramic powder, and an organic binder into a sheet,
Producing a ceramic green sheet by orienting the magnetic and conductive nanofibers or nanotubes in a direction perpendicular to the sheet surface of the sheet molded body by applying a magnetic field to the sheet molded body;
Firing the ceramic green sheet to produce a sheet-like ceramic sintered body; and
A method of manufacturing a ceramic capacitor comprising a step of forming an external electrode on a sheet surface of the ceramic sintered body. In the step of producing a ceramic green sheet by orienting nanofibers or nanotubes having magnetism and conductivity in a direction perpendicular to the sheet surface of the sheet molded body by applying a magnetic field to the sheet molded body, the sheet molded body The method for producing a ceramic capacitor according to claim 2, wherein the viscosity measured using a rotary viscometer is less than 100,000 Pa · s.

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