JP2011190123A - Method for manufacturing ceramic electronic component and ceramic raw material powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a ceramic electronic component of high reliability by attaining the improvement of a high temperature load life. <P>SOLUTION: The method is for manufacturing a ceramic electronic component which has a ceramic layer and electrodes, where the ceramic layer is composed of a dielectric ceramic composition containing a main component expressed by ABO<SB>3</SB>(wherein A is one or more selected from Ba, Ca and Sr, and B is one or more selected from Ti, Zr and Hf) and additional components, and includes a process for preparing a raw material powder of a main component and a gel compound slurry of at least a part of metallic elements or a solution of at least a part of metallic elements among metallic elements contained in additional components, a process for obtaining a raw material mixture by dispersing the raw material of a main component and the gel compound slurry or the solution, a process for drying the raw material mixture, and a process for heat-treating the raw material mixture after drying. As the gel compound slurry or the solution, a gel hydroxide slurry or an aqueous solution is preferable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ceramic electronic component and a method of manufacturing a ceramic raw material powder, and more particularly to a method of manufacturing a ceramic electronic component with improved reliability and a method of manufacturing a ceramic raw material powder suitable for the electronic component.

  A multilayer ceramic capacitor as an example of a ceramic electronic component is widely used as a small-sized, high-performance, high-reliability electronic component, and a large number of electric capacitors and electronic devices are used. In recent years, with the miniaturization and high performance of devices, the demand for further miniaturization, higher performance, and higher reliability of multilayer ceramic capacitors has become increasingly severe.

  In response to such demands, a dielectric ceramic composition is manufactured using raw material powders obtained by mixing main component raw material powders such as barium titanate and various additive powders having an effect of improving characteristics. The improvement of the characteristic is aimed at. However, there is a problem that sufficient reliability cannot be obtained simply by mixing the main component raw material powder and the additive component powder.

  In order to solve such a problem, it has been proposed to improve the characteristics by using a raw material powder obtained by coating a main component raw material powder with an additive component. For example, in Patent Document 1, an alkoxide solution of an additive element is added to a barium titanate powder slurry and calcined to obtain a raw material powder in which the additive element is coated on the surface of the barium titanate powder. It is disclosed. However, the synthesis of alkoxide has problems such as time consuming, high cost, and use of an organic solvent, resulting in a large environmental load.

Japanese Patent Laid-Open No. 10-139553

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a method of manufacturing a highly reliable ceramic electronic component that realizes an improvement in high-temperature load life. Another object of the present invention is to provide a method for producing a ceramic raw material powder suitable for producing a highly reliable ceramic electronic component.

In order to achieve the above object, a method of manufacturing a ceramic electronic component according to the present invention includes:
A method for producing a ceramic electronic component having a ceramic layer and an electrode, comprising:
The ceramic layer has a main component and an addition represented by the general formula ABO ₃ (A is at least one selected from Ba, Ca and Sr, and B is at least one selected from Ti, Zr and Hf). It is composed of a dielectric ceramic composition containing components,
Preparing a raw material powder of the main component and a gel compound slurry of at least a part of metal element or a solution of at least a part of metal element among the metal elements contained in the additive component;
Dispersing the raw material of the main component and the gelled compound slurry or the solution to obtain a raw material mixture;
Drying the raw material mixture;
Heat-treating the raw material mixture after drying.

  In the present invention, the raw material powder of the main component and the gel compound slurry of the metal element contained in the additive component or the solution of the metal element are dispersed and mixed. By setting the form of the additive component at the time of dispersion as described above, the main component raw material powder and the additive component can be uniformly dispersed and mixed. As a result, after drying, a ceramic raw material powder in which the additive component is uniformly coated on the surface of the main raw material powder is obtained. A ceramic electronic component with improved reliability can be obtained by manufacturing a ceramic electronic component using the ceramic raw material powder.

  In addition, the coated powder can be obtained in a short time and the cost can be reduced as compared with the case where the additive component is coated on the main component powder using alkoxide.

  Preferably, the gel compound slurry is a gel hydroxide slurry, and the solution is an aqueous solution. By using a gel hydroxide slurry or an aqueous solution, ceramic raw material powder in which additive components are uniformly coated on the surface of the main raw material powder can be easily obtained without using an organic solvent with a large environmental load. be able to.

  Preferably, the additive component includes a rare earth element oxide, and the rare earth element gel compound slurry or the rare earth element solution is prepared. More preferably, only the rare earth element gel compound slurry is prepared.

  Preferably, the additive component includes an alkaline earth metal element oxide and a sintering aid, the alkaline earth metal gel compound slurry or the alkaline earth metal solution, and the sintering aid. A metal element gel-like compound slurry or a solution of the metal element is prepared. More preferably, only the Mg gel compound slurry is prepared. In this specification, an alkaline earth metal element is synonymous with an element belonging to Group II of the periodic table.

  The effect of the present invention can be further improved by dispersing the raw material powder of the main component and the gel compound slurry or solution of the specific element. Moreover, about the rare earth element and Mg, the effect mentioned above can further be heightened by disperse | distributing not the form of a solution but the form of a gel-like compound slurry.

  Preferably, the raw material mixture is obtained using a medium stirring type disperser. More preferably, a medium having a diameter of 0.1 mm or less is used as the medium. The effects described above can be further enhanced by using such a disperser and medium.

  Preferably, in the heat treatment step, heat treatment is performed in a range of 400 to 900 ° C. By setting it as such a temperature range, the effect mentioned above can further be heightened.

  Preferably, the drying step and the heat treatment step are performed simultaneously. Even if it does in this way, the effect similar to the effect mentioned above can be acquired.

  Preferably, a dispersing agent is added in the step of obtaining the raw material mixture. More preferably, the dispersant is a hydrophilic dispersant. By adding a dispersing agent at the time of dispersion, the dispersibility of the raw material mixture can be further increased, and thus the above-described effects can be further enhanced.

  Preferably, a solvent and a binder resin are added to the raw material mixture after the heat treatment to obtain a paste composition.

Moreover, the method for producing a ceramic raw material powder according to the present invention includes:
A ceramic raw material comprising a main component and an additive component represented by the general formula ABO ₃ (A is at least one selected from Ba, Ca and Sr, and B is at least one selected from Ti, Zr and Hf) A method for producing a powder comprising:
Preparing a raw material powder of the main component and a gel compound slurry of at least a part of metal element or a solution of at least a part of metal element among the metal elements contained in the additive component;
Dispersing the raw material of the main component and the gelled compound slurry or the solution to obtain a raw material mixture;
Drying the raw material mixture;
Heat-treating the raw material mixture after drying to obtain a ceramic raw material powder.

FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor manufactured by a manufacturing method according to an embodiment of the present invention. FIG. 2 is a flowchart showing a process for producing a ceramic raw material powder.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

Multilayer ceramic capacitor 1
As shown in FIG. 1, the multilayer ceramic capacitor 1 includes a capacitor element body 10 having a configuration in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. The internal electrode layers 3 are laminated so that the end faces are alternately exposed on the surfaces of the two opposite ends of the capacitor element body 10. The pair of external electrodes 4 are formed at both ends of the capacitor element body 10 and are connected to the exposed end surfaces of the alternately arranged internal electrode layers 3 to constitute a capacitor circuit.

  The shape of the capacitor element body 10 is not particularly limited, but is usually a rectangular parallelepiped as shown in FIG. Moreover, there is no restriction | limiting in particular also in the dimension, What is necessary is just to set it as a suitable dimension according to a use.

Dielectric layer 2
As the dielectric ceramic composition forming the dielectric layers 2 is not particularly limited, in the present embodiment, the general formula ABO 3 _(A is at least one selected from Ba, Ca and Sr, B is Ti and A dielectric ceramic composition containing a main component represented by Zr) and an additive component.

The ABO _3, for example, _{{(Ba (1-x-} y) Ca x Sr y) O} such _{A (Ti (1-z)} Zr z) compound represented by the B _{O 2} is preferred. Note that A, B, x, y, and z are all in an arbitrary range. In this embodiment, in particular, BaTiO ₃ (preferably represented by the composition formula Ba _m TiO _{2 + m} , m is 0.995 ≦ m ≦ 1.010, and the ratio of Ba to Ti is 0.995 ≦ Ba / Ti ≦ 1.010) can be preferably used.

  Additive components include rare earth element oxides, alkaline earth metal oxides, and sintering aids.

The oxide content of the rare earth element is preferably 0.2 to 3.0 mol in terms of rare earth element with respect to 100 mol of ABO ₃ . Although it does not restrict | limit especially as a rare earth element, Y, Dy, Ho, Gd, Yb, Er, Tb etc. are mentioned. The rare earth element may be a plurality of elements or one kind of element. In the case of a plurality of elements, for example, at least one selected from the group consisting of Y, Yb, Er and Ho and at least one selected from the group consisting of Dy, Gd and Tb are preferable.

The content of the alkaline earth metal oxide is preferably 0.6 to 2.5 mol, more preferably 0.8 to 2.0 mol, in terms of alkaline earth metal element, with respect to 100 mol of ABO _3. It is. The alkaline earth metal is not particularly limited, but is preferably Mg.

The content of the sintering aid is preferably 0.2 to 2.0 mol, more preferably 0.8 to 1.5, in terms of the metal element constituting the sintering aid, with respect to 100 mol of ABO _3. Is a mole. Is not particularly limited as a sintering aid, in the present embodiment, is a component that contains preferably a component containing SiO _2, and an oxide of oxide and / or Ca in the Ba, an oxide of Si It is more preferable. As such components, Ba oxide, Ca oxide, and Si oxide may be included in the form of each oxide, or may be included in the form of a composite oxide or glass. Good. As for Si, an Si fine particle aqueous dispersion may be prepared as described later. In this component, a + b + c = 1 and a + b ≦ c, where a is the molar ratio of Ba, b is the molar ratio of Ca, and c is the molar ratio of Si.

Moreover, in this embodiment, it is preferable to further contain at least one oxide selected from the group consisting of V, Mo and W. The content of these oxides is preferably 0.001 to 0.2 mol, more preferably 0.02 to 0.15 mol in terms of V, Mo and W with respect to 100 mol of ABO ₃ .

Moreover, in this embodiment, it is preferable to contain the oxide of Mn and / or Cr further. The content of these oxides is preferably 0.01 to 0.6 mol, more preferably 0.05 to 0.3 mol in terms of Mn and / or Cr with respect to 100 mol of ABO ₃ .

  The dielectric ceramic composition according to the present embodiment may further contain other components according to desired characteristics.

  The thickness of the dielectric layer 2 is not particularly limited, but is preferably 2 μm or less per layer. Although the minimum of thickness is not specifically limited, For example, it is about 0.5 micrometer.

  The number of laminated dielectric layers 2 is not particularly limited, but is preferably 20 or more, more preferably 50 or more, and particularly preferably 100 or more. The upper limit of the number of stacked layers is not particularly limited, but is about 2000, for example.

Internal electrode layer 3
The conductive material contained in the internal electrode layer 3 is not particularly limited, but a relatively inexpensive base metal can be used because the material constituting the dielectric layer 2 has reduction resistance. As the base metal used as the conductive material, Ni or Ni alloy is preferable. The Ni alloy is preferably an alloy of Ni and one or more elements selected from Mn, Cr, Co and Al, and the Ni content in the alloy is preferably 95% by weight or more. In addition, in Ni or Ni alloy, various trace components, such as P, may be contained about 0.1 wt% or less. The thickness of the internal electrode layer 3 may be appropriately determined according to the application and the like, but is usually 0.1 to 3 μm, particularly preferably about 0.2 to 2.0 μm.

External electrode 4
The conductive material contained in the external electrode 4 is not particularly limited, but in the present invention, inexpensive Ni, Cu, and alloys thereof can be used. The thickness of the external electrode 4 may be appropriately determined according to the application and the like, but is usually preferably about 10 to 50 μm.

Manufacturing Method of Multilayer Ceramic Capacitor 1 The multilayer ceramic capacitor 1 shown in FIG. 1 is manufactured by the manufacturing method according to this embodiment. Hereinafter, the manufacturing method will be specifically described. In FIG. 2, the process of producing ceramic raw material powder is shown as a flowchart.

First, an ABO ₃ raw material powder constituting the dielectric ceramic composition and a gel compound slurry of a metal element contained in the additive component or a solution of the element are prepared. The gel compound is not particularly limited and is preferably a gel hydroxide, a gel carbide, a gel oxide, or the like. In this embodiment, a gel hydroxide is prepared.

  The metal element solution is not particularly limited, and an aqueous metal element solution is preferable. In this embodiment, an aqueous solution of the element is prepared. The metal salt used in the aqueous solution is preferably used in the form of acetate, citrate, succinate or the like. In this embodiment, acetate is used.

  However, for Si, a gel slurry using ethanol as a solvent is prepared, or an Si fine particle aqueous dispersion (aqueous dispersion) is prepared. As the Si fine particle aqueous dispersion, a dispersion in which silica colloid is dispersed in water is prepared.

The raw material powder of ABO ₃ is not particularly limited, and oxides of the above-described components, mixtures thereof, and composite oxides can be used. In addition, various compounds that become the above-described oxides and composite oxides by firing, For example, it can be appropriately selected from carbonates, oxalates, nitrates, hydroxides, organometallic compounds, and the like, and can be used as a mixture.

ABO ₃ raw materials are produced by various methods such as those produced by various liquid phase methods (for example, oxalate method, hydrothermal synthesis method, alkoxide method, sol-gel method, etc.) in addition to the so-called solid phase method. Can be used.

  As the gel hydroxide slurry or aqueous solution of the metal element contained in the additive component, at least the above-described rare earth element gel hydroxide slurry or aqueous solution may be prepared. In particular, the rare earth element is preferably prepared as a gel hydroxide slurry. Furthermore, a gel-like hydroxide slurry or aqueous solution of an alkaline earth metal element other than Ba and Ca may be prepared as necessary. Moreover, you may prepare the gel-like hydroxide slurry or aqueous solution of elements, such as V and Mn.

  In addition, about Ba and Ca, what is necessary is just to prepare as a gel-like compound slurry or aqueous solution, but it is preferable to prepare as aqueous solution. When using a gel compound slurry, it is preferable to use a gel carbonate slurry.

  The total amount of the metal element contained in the additive component may not be added in the form of a gel hydroxide slurry or an aqueous solution. For example, the dielectric ceramic composition according to the present embodiment may be manufactured using a rare earth element gel hydroxide slurry and a rare earth element oxide powder.

The hydroxide particles in the gel hydroxide slurry are very fine, for example, the particle diameter is about 5 to 10 nm. The hydroxide particles in the gel hydroxide slurry are uniformly dispersed together with the ABO ₃ raw material powder in the mixing step described later, and coat the surface of the ABO ₃ particles after drying. Further, the element dissolved in the aqueous solution also covers the surface of the ABO ₃ particles after drying.

  For example, when an alkoxide or the like is used as an additive component, there are disadvantages that the price is high and the reaction takes a long time. Moreover, it is necessary to use an organic solvent, and an environmental impact is large. On the other hand, in the present embodiment, by using a gel hydroxide slurry or an aqueous solution of the element as an additive component, it is possible to improve productivity, improve environmental load, and reduce cost.

Next, in the present embodiment, the raw material powder of ABO ₃ and the gel-like hydroxide slurry or aqueous solution of the additive component element obtained above are preliminarily dispersed together with water. This preliminary dispersion is performed to lightly disperse the ABO ₃ raw material powder and the gel hydroxide slurry, and is not intended to crush the ABO ₃ raw material powder. The preliminary dispersion is performed for about 1 to 2 hours using, for example, a ball mill. At this time, a stirrer such as a disperser other than the ball mill may be used.

  Next, the pre-dispersed mixture is dispersed using a medium stirring type disperser to obtain a raw material mixture. In this embodiment, a bead mill is used as the medium stirring type disperser. The conditions for dispersing and mixing are not particularly limited, but for example, a medium having a diameter of 0.1 mm or less is preferably used.

In this dispersion, the ABO ₃ raw material powder and the additive component (gel hydroxide or added metal element in the aqueous solution) are uniformly dispersed while crushing the ABO ₃ raw material powder. As a result, after drying, the ABO ₃ particle surface can be coated with a gel hydroxide or the like. In this dispersion, it is preferable to further improve the dispersibility of the raw material mixture by adding a hydrophilic dispersant. Examples of hydrophilic dispersants include polycarboxylic acid-based dispersants.

The obtained raw material mixture is dried. In the raw material mixture after drying, the surface of the ABO ₃ particles is covered with the additive metal element in the gel hydroxide slurry or the aqueous solution. That is, the element added as a gel hydroxide slurry or an aqueous solution is physically covered with ABO ₃ particles (adsorption).

  The drying method is not particularly limited, and may be appropriately selected from stationary drying, spray drying, freeze drying, and the like. Further, the drying temperature is not particularly limited as long as the solvent can be removed from the raw material mixture.

Through these steps, by manufacturing a raw material mixture, while minimizing the damage given to the ABO ₃ particles as a main component (while maintaining the crystallinity of the ABO ₃ particles), yet rare earth ABO ₃ particle A compound such as an element can be uniformly coated.

Furthermore, by doing the above, it is possible to control the solid solution of the above element with respect to the ABO ₃ particles in the heat treatment step and the firing step described later, and as a result, the dielectric ceramic composition in which desired characteristics are realized. Can be obtained. For example, it is possible to prevent the rare earth element from being excessively dissolved in the ABO ₃ particle by coating the rare earth element on the ABO ₃ particle in the form of a gel hydroxide. As a result, reliability can be improved.

Therefore, in order to maintain the crystallinity of the ABO ₃ particles, the specific surface area of the coated ABO ₃ raw material powder contained in the raw material mixture after drying is measured by the BET method, and the ABO ₃ raw material powder before preliminary dispersion is measured. It is preferably 1.4 times or less of the specific surface area of the body.

Subsequently, the dried raw material mixture is heat treated. By performing this heat treatment, the additive component element coated on the surface of the ABO ₃ particles is more firmly fixed to the particles. For this heat treatment, for example, a rotary kiln, a tunnel furnace, or a batch furnace can be used. The holding temperature in the heat treatment is preferably in the range of 400 to 900 ° C. The holding time is preferably 0.2 to 3.0 hours. In addition, you may perform simultaneously drying and heat processing of a raw material mixture. Examples of the method performed simultaneously include a spray pyrolysis method.

  Since the raw material mixture is agglomerated after the heat treatment, the raw material mixture may be crushed to such an extent that the agglomeration is loosened. This crushing may be performed at the time of preparing a dielectric layer paste described later.

  The particle size of the raw material mixture (ceramic raw material powder) after the heat treatment is usually about 0.1 to 1 μm in average particle size. Next, as shown in FIG. 2, a ceramic raw material powder is made into a paint to prepare a dielectric layer paste. The dielectric layer paste may be an organic coating material obtained by kneading a dielectric material (ceramic material powder) and an organic vehicle, or may be a water-based coating material.

  An organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from usual various binders such as ethyl cellulose and polyvinyl butyral. The organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like according to a method to be used such as a printing method or a sheet method.

  Further, when the dielectric layer paste is used as a water-based paint, a water-based vehicle in which a water-soluble binder or a dispersant is dissolved in water and a dielectric material may be kneaded. The water-soluble binder used for the water-based vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, water-soluble acrylic resin, etc. may be used.

  The internal electrode layer paste is made by kneading the above-mentioned organic vehicle with various conductive metals and alloys as described above, or various oxides, organometallic compounds, resinates, etc. that become the above-mentioned conductive materials after firing. Prepare. The internal electrode layer paste may contain a common material. The common material is not particularly limited, but preferably has the same composition as the main component.

  The external electrode paste may be prepared in the same manner as the internal electrode layer paste described above.

  There is no restriction | limiting in particular in content of the organic vehicle in each above-mentioned paste, For example, what is necessary is just about 1-5 weight% of binders, for example, about 10-50 weight% of binders. Each paste may contain additives selected from various dispersants, plasticizers, dielectrics, insulators, and the like as necessary. The total content of these is preferably 10% by weight or less.

  When the printing method is used, the dielectric layer paste and the internal electrode layer paste are printed and laminated on a substrate such as PET, cut into a predetermined shape, and then peeled from the substrate to obtain a green chip.

  When the sheet method is used, a green sheet is formed using a dielectric layer paste, an internal electrode layer paste is printed thereon to form an internal electrode pattern, and these are stacked to form a green chip. .

  Before firing, the green chip is subjected to binder removal processing. As binder removal conditions, the temperature rising rate is preferably 5 to 300 ° C./hour, the holding temperature is preferably 180 to 400 ° C., and the temperature holding time is preferably 0.5 to 24 hours. The binder removal atmosphere is air or a reducing atmosphere.

  In firing the green chip, the rate of temperature rise is preferably 200 to 2000 ° C./hour.

  The holding temperature during firing is preferably 1300 ° C. or less, more preferably 1100 to 1250 ° C., and the holding time is preferably 0.5 to 8 hours, more preferably 1 to 3 hours. If the holding temperature is lower than the above range, the densification becomes insufficient. If the holding temperature is higher than the above range, the electrode is interrupted due to abnormal sintering of the internal electrode layer, the capacity temperature characteristic is deteriorated due to diffusion of the constituent material of the internal electrode layer, and the dielectric Reduction of the body porcelain composition is likely to occur.

The firing atmosphere is preferably a reducing atmosphere. As the atmosphere gas, for example, a mixed gas of N ₂ and H ₂ can be used by humidification.

In addition, the oxygen partial pressure during firing may be appropriately determined according to the type of the conductive material in the internal electrode layer paste, but when a base metal such as Ni or Ni alloy is used as the conductive material, The oxygen partial pressure is preferably 10 ⁻¹⁴ to 10 ⁻¹⁰ MPa. When the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may be abnormally sintered and may be interrupted. Further, when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized. The temperature lowering rate is preferably 50 to 2000 ° C./hour.

  After firing in a reducing atmosphere, the capacitor element body is preferably annealed. Annealing is a process for re-oxidizing the dielectric layer, and thereby the IR life (insulation resistance life) can be remarkably increased, so that the reliability is improved.

The oxygen partial pressure in the annealing atmosphere is preferably 10 ⁻⁹ to 10 ⁻⁵ MPa. When the oxygen partial pressure is less than the above range, it is difficult to re-oxidize the dielectric layer, and when it exceeds the above range, oxidation of the internal electrode layer tends to proceed.

  The holding temperature at the time of annealing is preferably 1100 ° C. or less, particularly 900-1100 ° C. When the holding temperature is lower than the above range, the dielectric layer is not sufficiently oxidized, so that the IR is low and the IR life tends to be short. On the other hand, if the holding temperature exceeds the above range, not only the internal electrode layer is oxidized and the capacity is lowered, but the internal electrode layer reacts with the dielectric substrate, the capacity temperature characteristic is deteriorated, the IR is lowered, the IR Life is likely to decrease. Note that annealing may be composed of only a temperature raising process and a temperature lowering process. That is, the temperature holding time may be zero. In this case, the holding temperature is synonymous with the maximum temperature.

As other annealing conditions, the temperature holding time is preferably 0 to 20 hours, more preferably 2 to 4 hours, and the cooling rate is preferably 50 to 500 ° C./hour, more preferably 100 to 300 ° C./hour. . Further, as the annealing atmosphere gas, for example, humidified N ₂ gas or the like is preferably used.

In the above-described binder removal processing, firing and annealing, for example, a wetter or the like may be used to wet the N ₂ gas or mixed gas. In this case, the water temperature is preferably about 5 to 75 ° C.

  The binder removal treatment, firing and annealing may be performed continuously or independently.

  The capacitor element main body obtained as described above is subjected to end face polishing, for example, by barrel polishing or sand blasting, and the external electrode paste is applied and fired to form the external electrode 4. Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.

  The multilayer ceramic capacitor of this embodiment manufactured in this way is mounted on a printed circuit board or the like by soldering or the like and used for various electronic devices.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the embodiment mentioned above at all, and can be variously modified within the range which does not deviate from the summary of this invention.

  In the above-described embodiment, the multilayer ceramic capacitor is exemplified as the ceramic electronic component manufactured according to the present invention. However, the ceramic electronic component is not limited to the multilayer ceramic capacitor and has the above-described configuration. Anything is fine.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Example 1
First, BaTiO ₃ powder was prepared as a raw material powder for ABO ₃ . For the sample number 1 shown in Table 1 as the raw material of the additive component, Y oxide powder, Dy oxide powder, Mg oxide powder, Mn oxide powder, V oxide powder Ba oxide powder, Ca oxide powder and Si oxide powder were prepared.

  For sample number 2 shown in Table 1, a gel hydroxide slurry of additive components other than Si was prepared, and for Si, a gel slurry using ethanol as a solvent was prepared.

  For sample number 3 shown in Table 1, for the additive components other than Si, a gel-like hydroxide slurry is prepared as in sample number 2, and for Si, the particle size synthesized by the sol-gel method is 10 to 10 A Si aqueous dispersion in which colloidal silica of about 20 nm was dispersed with water was prepared.

  For sample number 4 shown in Table 1, a gel-like hydroxide slurry was prepared for Y and Dy among the additive components in the same manner as for sample number 2. For each element other than Y and Dy, an aqueous solution of each element was prepared. About Si, the same thing as sample number 3 was prepared.

  For Sample No. 5 shown in Table 1, an aqueous solution of additive components other than Si was prepared, and for Si, the same as Sample No. 3 was prepared.

In addition, with respect to 100 mol of BaTiO ₃ , the addition amount of the additive component is 0.25 mol in terms of Y for Y oxide, 0.50 mol in terms of Dy oxide, and 1.75 in terms of Mg oxide for Mg. Mol, Mn oxide is 0.20 mol in terms of Mn, V oxide is 0.0010 mol in terms of V, and the sintering aid component is 1.40 mol in total in terms of Ba, Ca, Si. Weighed.

Next, the BaTiO ₃ powder and the raw material of the additive component were preliminarily dispersed for 1 hour using a ball mill. The raw material mixture after the preliminary dispersion was dispersed and mixed for 48 hours using a bead mill filled with a medium having a diameter of 0.1 mm to prepare a raw material mixture. That is, in sample number 1, BaTiO ₃ powder and oxide powder of each element are dispersed and mixed, and in sample numbers 2 to 4, BaTiO ₃ powder and gel hydroxide or aqueous solution of each element are dispersed. Mixed. Further, as a dispersant, 1.5 wt% of a polycarboxylic acid dispersant was added to 100 wt% of the dielectric material.

  The obtained raw material mixture was dried at 250 ° C. by a spray dryer, and then heat-treated at 750 ° C. for 15 minutes in a rotary kiln. The raw material mixture (ceramic raw material powder) after the heat treatment was used as a dielectric raw material.

  Next, the obtained dielectric material: 100 parts by weight, polyvinyl butyral resin: 10 parts by weight, dioctyl phthalate (DOP) as a plasticizer: 5 parts by weight, and alcohol as a solvent: 100 parts by weight with a ball mill The mixture was made into a paste to obtain a dielectric layer paste.

  In addition to the above, Ni particles: 44.6 parts by weight, terpineol: 52 parts by weight, ethyl cellulose: 3 parts by weight, and benzotriazole: 0.4 parts by weight are kneaded with three rolls to obtain a slurry. To prepare an internal electrode layer paste.

  Then, using the dielectric layer paste prepared above, a green sheet was formed on the PET film so that the thickness after drying was 1.0 μm. Next, the electrode layer was printed in a predetermined pattern using the internal electrode layer paste thereon, and then the sheet was peeled off from the PET film to produce a green sheet having the electrode layer. Next, a plurality of green sheets having electrode layers were laminated and pressure-bonded to obtain a green laminated body, and the green laminated body was cut into a predetermined size to obtain a green chip.

  Next, the obtained green chip was subjected to binder removal treatment, firing and annealing under the following conditions to obtain a multilayer ceramic fired body.

  The binder removal treatment conditions were temperature rising rate: 25 ° C./hour, holding temperature: 260 ° C., temperature holding time: 8 hours, and atmosphere: in the air.

The firing conditions were a heating rate: 1000 ° C./hour, a holding temperature: 1190 ° C., and a holding time of 1 hour. The cooling rate was 1000 ° C./hour. The atmospheric gas was a humidified N ₂ + H ₂ mixed gas, and the oxygen partial pressure was 10 ⁻¹² MPa.

The annealing conditions were: temperature rising rate: 200 ° C./hour, holding temperature: 1000 ° C., temperature holding time: 2 hours, temperature falling rate: 200 ° C./hour, atmospheric gas: humidified N ₂ gas (oxygen partial pressure: 10 ⁻⁷ MPa).

  A wetter was used for humidifying the atmospheric gas during firing and annealing.

  Next, after polishing the end face of the obtained multilayer ceramic fired body by sandblasting, Cu was applied as an external electrode to obtain a sample of the multilayer ceramic capacitor shown in FIG. The size of the obtained capacitor sample was 3.2 mm × 1.6 mm × 0.6 mm, the thickness of the dielectric layer was about 0.9 μm, the thickness of the internal electrode layer was about 0.7 μm, and was sandwiched between the internal electrode layers The number of dielectric layers was 100.

  About the obtained capacitor | condenser sample, the dielectric constant, dielectric loss, CR product, a capacitance temperature characteristic, and the high temperature load lifetime (HALT) were measured by the method shown below, respectively.

Dielectric constant ε _r
The relative dielectric constant ε _r was measured for a capacitor sample at a reference temperature of 25 ° C. with a digital LCR meter (4274A manufactured by YHP) under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms. Calculated from capacitance (no unit). It is preferable that the relative dielectric constant is high. In this example, 2500 or more was considered good. The results are shown in Table 1.

Dielectric loss (tan δ)
The dielectric loss (tan δ) was measured for a capacitor sample at a reference temperature of 25 ° C. using a digital LCR meter (4274A manufactured by YHP) under the conditions of a frequency of 1 kHz and an input signal level (measurement voltage) of 0.5 Vrms. The dielectric loss is preferably as low as possible. In this example, 5.0% or less was considered good. The results are shown in Table 1.

The insulation resistance IR after applying a DC voltage of 6.3 V / μm to the capacitor sample for 1 minute at 20 ° C. was measured for the CR product capacitor sample using an insulation resistance meter (R8340A manufactured by Advantest). The CR product was measured by determining the product of the capacitance C (unit: μF) measured above and the insulation resistance IR (unit: MΩ). In the present embodiment, 1000 or more is good, and 1500 or more is more preferable. The results are shown in Table 1.

Capacitance temperature characteristics (TC)
The capacitance at −55 to 85 ° C. was measured for the capacitor sample, the rate of change ΔC in capacitance was calculated, and it was evaluated whether the E5 standard X5R characteristic or B characteristic was satisfied. That is, it was evaluated whether the change rate ΔC was within ± 15% at −55 to 85 ° C. The results are shown in Table 1.

High temperature load life (HALT)
The capacitor sample was maintained at 160 ° C. in an applied DC voltage under an electric field of 9 V / μm, and the lifetime was measured to evaluate the high temperature load life. In this example, the time from the start of application until the insulation resistance drops by an order of magnitude was defined as the lifetime. In this example, the above evaluation was performed on 20 capacitor samples, and the average value was defined as the high temperature load life. The evaluation standard is good for 50 hours or more, and more preferably 60 hours or more. The results are shown in Table 1.

From Table 1, it was confirmed that when the additive component was dispersed and mixed with the BaTiO ₃ powder in the form of oxide powder (sample number 1), the high temperature load life was deteriorated. It was also confirmed that the CR product also tends to be inferior to the other samples. On the other hand, when the additive component was dispersed with BaTiO ₃ powder in the form of a gel hydroxide slurry or an aqueous solution (sample numbers 2 to 5), it was confirmed that the high temperature load life was improved. In particular, when the rare earth elements (Y and Dy) were dispersed in the form of a gel hydroxide slurry (sample numbers 2 to 4), it was confirmed that the high temperature load life was good.

  Moreover, when Ba and Ca were disperse | distributed in the form of aqueous solution (sample number 4), it has confirmed that a high temperature load lifetime improved a little compared with the case where it uses in the form of a gel slurry (sample number 3).

Example 2
A sample of the multilayer ceramic capacitor was prepared in the same manner as in Sample No. 2 of Example 1, except that the medium stirring type disperser used in the dispersion step and the diameter of the medium used were shown in Table 2. Example 1 The same characteristic evaluation was performed. The results are shown in Table 2.

  From Table 2, it was confirmed that when the diameter of the medium used was large (sample numbers 6 and 7), the dielectric loss, the capacity-temperature characteristics, and the high temperature load life tended to deteriorate. Moreover, it was confirmed that the high temperature load life tends to be deteriorated even when the dispersion mixing is performed only with the stirring blades (sample number 8) instead of the medium stirring type disperser.

Example 3
A multilayer ceramic capacitor sample was produced in the same manner as in Sample No. 2 of Example 1 except that drying and heat treatment were simultaneously performed by spray pyrolysis, and the same characteristic evaluation as in Example 1 was performed. The results are shown in Table 3.

  From Table 3, it was confirmed that the effects of the present invention can be obtained even when drying and heat treatment are performed simultaneously.

DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic capacitor 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode 10 ... Capacitor element main body

Claims (14)

A method for producing a ceramic electronic component having a ceramic layer and an electrode, comprising:
The ceramic layer has a main component and an addition represented by the general formula ABO ₃ (A is at least one selected from Ba, Ca and Sr, and B is at least one selected from Ti, Zr and Hf). It is composed of a dielectric ceramic composition containing components,
Preparing a raw material powder of the main component and a gel compound slurry of at least a part of metal element or a solution of at least a part of metal element among the metal elements contained in the additive component;
Dispersing the raw material of the main component and the gelled compound slurry or the solution to obtain a raw material mixture;
Drying the raw material mixture;
And a step of heat-treating the raw material mixture after drying.   The method for producing a ceramic electronic component according to claim 1, wherein the gel compound slurry is a gel hydroxide slurry, and the solution is an aqueous solution.   3. The method of manufacturing a ceramic electronic component according to claim 1, wherein the additive component includes an oxide of a rare earth element, and the gel compound slurry of the rare earth element or the rare earth element solution is prepared.   4. The method for producing a ceramic electronic component according to claim 3, wherein only the rare earth element gel compound slurry is prepared.   The additive component contains an oxide of an alkaline earth metal element and a sintering aid, the alkaline earth metal gel compound slurry or the alkaline earth metal solution, and a role as the sintering aid The manufacturing method of the ceramic electronic component in any one of Claims 1-4 which prepares the gel-like compound slurry of the metallic element which has this, or the solution of this metallic element.   The method for producing a ceramic electronic component according to claim 5, wherein only the gel compound slurry of Mg is prepared.   The manufacturing method of the ceramic electronic component in any one of Claims 1-6 which obtains the said raw material mixture using a medium stirring type disperser.   The method of manufacturing a ceramic electronic component according to claim 7, wherein a medium having a diameter of 0.1 mm or less is used as the medium.   The method for manufacturing a ceramic electronic component according to claim 1, wherein the heat treatment is performed in a range of 400 to 900 ° C. in the heat treatment step.   The method for manufacturing a ceramic electronic component according to claim 1, wherein the drying step and the heat treatment step are performed simultaneously.   The method for producing a ceramic electronic component according to claim 1, wherein a dispersant is added in the step of obtaining the raw material mixture.   The method for manufacturing a ceramic electronic component according to claim 11, wherein the dispersant is a hydrophilic dispersant.   The manufacturing method of the ceramic electronic component in any one of Claims 1-12 which add a solvent and binder resin to the raw material mixture after heat processing, and obtain a paste composition. A ceramic raw material comprising a main component and an additive component represented by the general formula ABO ₃ (A is at least one selected from Ba, Ca and Sr, and B is at least one selected from Ti, Zr and Hf) A method for producing a powder comprising:
Preparing a raw material powder of the main component and a gel compound slurry of at least a part of metal element or a solution of at least a part of metal element among the metal elements contained in the additive component;
Dispersing the raw material of the main component and the gelled compound slurry or the solution to obtain a raw material mixture;
Drying the raw material mixture;
Heat-treating the raw material mixture after drying to obtain a ceramic raw material powder.

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