JP2008218974A - Electronic component and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic components, such as stacked ceramic capacitor, and a method of manufacturing electronic component, that can prevent IR deterioration, as well as, cracks and peeling of an internal electrode layer and deterioration in the electrostatic capacity. <P>SOLUTION: The electronic component has a component body 4 that includes internal electrode layers 12 and ceramic layers 10. The internal electrode layers 12 contain Ni and at least one element selected from among a group of Re, Ru, Os and Ir. The ceramic layers contain at least one element selected from s group of Re, Ru, Os and Ir. The ceramic layers 10 do not substantially contain Re, Ru, Os and Ir. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic component such as a multilayer ceramic capacitor and a manufacturing method thereof.

  A multilayer ceramic capacitor as an example of an electronic component includes an element body having a multilayer structure in which a plurality of ceramic layers (dielectric layers) and internal electrode layers are alternately arranged, and a pair of elements formed at both ends of the element body. It consists of external terminal electrodes.

  In the production of this multilayer ceramic capacitor, first, a plurality of dielectric layers before firing and internal electrode layers before firing are alternately laminated in a necessary number to form a laminate. Next, this laminate is cut to a predetermined size to form a green chip. Next, the green chip is subjected to binder removal processing, firing processing, and annealing processing to obtain a capacitor element body. A multilayer ceramic capacitor is obtained by forming a pair of external terminal electrodes at both ends of the element body.

  Thus, when manufacturing the multilayer ceramic capacitor, the dielectric layer before firing and the internal electrode layer before firing are fired simultaneously as a green chip. For this reason, the conductive material contained in the internal electrode layer before firing must have a melting point higher than the sintering temperature of the dielectric powder contained in the dielectric layer before firing, or must not react with the dielectric powder. Is done.

  Examples of the conductive material having a high melting point include noble metals such as Pt and Pd. However, since noble metals are expensive, it has been a problem that the multilayer ceramic capacitor using the noble metals is expensive. Therefore, conventionally, a base metal such as Ni, which is cheaper than a noble metal, has been frequently used as a conductive material.

  However, when Ni is used as a conductive material, the problem is that the melting point of Ni (sintering temperature of the internal electrode layer) is lower than the sintering temperature of the dielectric powder. If the pre-fired dielectric layer and the pre-fired internal electrode layer are fired simultaneously at a high temperature (a temperature close to the sintering temperature of the dielectric powder), the internal electrode layer may be cracked or peeled off. On the other hand, if the pre-fired dielectric layer and the pre-fired internal electrode layer are fired simultaneously at a low temperature (a temperature close to the sintering temperature of the internal electrode layer), the dielectric powder may be insufficiently sintered.

  Further, if the thickness of the internal electrode layer before firing is made too thin in order to reduce the size and increase the capacity of the capacitor, Ni particles contained in the conductive material grow and become spherical when fired in a reducing atmosphere. That was the problem. When the Ni particles are spheroidized, an interval is generated between the Ni particles connected to each other before firing. That is, voids are formed at arbitrary locations in the fired internal electrode layer, and the fired internal electrode layer becomes discontinuous. When the internal electrode layer after firing is not continuous (disconnected), the capacitance of the multilayer ceramic capacitor is reduced.

  As a countermeasure against the above-described problems associated with the use of Ni, as shown in Patent Document 1, a part of the internal electrode layer is made of at least one selected from the group consisting of Ni and Ru, Rh, Re, and Pt. The method of comprising with the alloy layer containing an element is mentioned. In this method, cracking and peeling of the internal electrode layer after sintering and poor sintering of the dielectric powder can be prevented. Moreover, the spheroidization of the Ni-based alloy particles can be suppressed. As a result, the internal electrodes can be formed continuously, and a reduction in the capacitance of the capacitor can be suppressed.

However, the method disclosed in Patent Document 1 has a problem that the IR (insulation resistance) of the capacitor may be reduced as a result of forming a part of the internal electrode layer of a Ni-based alloy. There has been a demand for effective measures against this IR reduction.
JP 2004-319969 A

  An object of the present invention is to provide an electronic component such as a multilayer ceramic capacitor capable of preventing IR deterioration and preventing internal electrode layers from cracking and peeling, and a decrease in capacitance, and a method for manufacturing the same. It is.

  As a result of intensive studies by the present inventors, it has been found that the reduction of IR in the capacitor is caused by the oxidation of metal atoms such as Re contained in the internal electrode layer and diffusion to the ceramic layer (dielectric layer). It was. Therefore, the present inventor has invented the following electronic components and manufacturing method thereof in order to achieve the above-described object.

The electronic component according to the present invention is
An electronic component having an element body including an internal electrode layer and a ceramic layer,
The internal electrode layer includes at least one element of Re, Ru, Os, and Ir;
Ni, and
The ceramic layer is substantially free of Re, Ru, Os, and Ir.

  In the present invention, the ceramic layer is preferably a dielectric layer.

  In the manufacturing process of the electronic component, when the fired body is annealed, at least one element of Re, Ru, Os, and Ir contained in the internal electrode layer is oxidized, and enters the ceramic layer adjacent to the internal electrode layer. Spread. As a result, in the completed electronic component, the ceramic layer may also contain at least one element of Re, Ru, Os, and Ir. Therefore, in the present invention, IR deterioration can be prevented by making the ceramic layer substantially free of Re, Ru, Os, and Ir.

  Moreover, the internal electrode layer contains not only Ni but also at least one element of Re, Ru, Os, and Ir having a melting point higher than Ni as a conductive material, so that the sintering temperature of the conductive material is increased. Then, it approaches the sintering temperature of the dielectric powder. As a result, cracking and peeling of the internal electrode layer after sintering can be prevented, and defective sintering of the dielectric powder can be prevented. Therefore, the capacitance and IR of the capacitor are improved.

  The internal electrode layer preferably includes Re among Re, Ru, Os, and Ir. The total content of Re, Ru, Os, and Ir contained in the ceramic layer is preferably as small as possible, and most preferably 0.

  The content ratio of Ni contained in the internal electrode layer is preferably 80 mol% or more and less than 100 mol%, more preferably 87 mol% or more and less than 100 mol%, with respect to all metal components contained in the internal electrode layer.

  The total content of Re, Ru, Os, and Ir contained in the internal electrode layer is preferably more than 0 mol% and not more than 20 mol%, more preferably, with respect to all metal components contained in the internal electrode layer. Is 0.1 mol% or more and 13 mol% or less.

  Preferably, in the internal electrode layer, at least one element of Re, Ru, Os, and Ir and Ni form an alloy. More preferably, Re and Ni form an alloy in the internal electrode layer.

The method of manufacturing an electronic component according to the present invention is as follows:
Forming a green chip having an internal electrode layer film;
Firing the green chip to form a fired body;
The oxygen partial pressure is preferably more than 0.00061 Pa and less than 1.3 Pa, more preferably 10 ^{−3 to 1} Pa, even more preferably 0.0015 to 0.57 Pa, and the temperature is preferably more than 600 ° C. and less than 1100 ° C., More preferably, the device body is formed by annealing the fired body in an annealing atmosphere of 700 ° C. or higher and lower than 1100 ° C., more preferably 900 ° C. or higher and lower than 1100 ° C.

  In addition, in this invention, the film | membrane for internal electrode layers means the site | part used as an internal electrode layer in the electronic component after completion.

  By annealing the fired body in the above annealing atmosphere, it is possible to suppress the diffusion of Re, Ru, Os, and Ir contained in the internal electrode layer into the dielectric layer. As a result, in the completed electronic component, Re, Ru, Os, and Ir can be substantially not included in the ceramic layer.

  Further, by annealing the fired body in the above atmosphere, the dielectric layer is re-oxidized and semiconductor formation is prevented. Therefore, IR deterioration can be prevented.

  Furthermore, by reducing the oxygen partial pressure even in the above atmosphere, it is possible to suppress oxidation of the electrode near the terminal.

Preferably, the green chip is fired to form the fired body in an atmosphere having an oxygen partial pressure of 10 ⁻¹⁰ to 10 ⁻² Pa and a temperature of 1000 to 1300 ° C.

  The internal electrode layer film (including the green chip) is fired in the above atmosphere to raise the sintering start temperature of the conductive material (Ni-based alloy) and to grow the conductive material (Ni-based alloy). And spheroidization can be suppressed. As a result, the internal electrode layer can be formed continuously and without interruption, and a reduction in the capacitance of the capacitor can be suppressed.

  Preferably, the internal electrode layer film is formed by a thin film method. As the thin film method, a sputtering method or a vapor deposition method is preferably used.

  Preferably, the internal electrode layer film has a crystallite size of 10 to 100 nm.

  Preferably, the internal electrode layer film is formed by a printing method using a conductive paste containing an alloy powder having an average particle diameter of 0.01 to 1 μm.

  Preferably, an alloy film is formed by a thin film method (preferably a sputtering method or a vapor deposition method), and the alloy powder is formed by pulverizing the alloy film.

  Preferably, the alloy powder has a crystallite size of 10 to 100 nm.

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

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.
2A, 2B, 2C and FIGS. 3A, 3B, and 3C are main part sectional views showing a method for transferring a film for an internal electrode layer in a manufacturing process of a multilayer ceramic capacitor according to an embodiment of the present invention.
FIG. 4A illustrates a TEM-EDS spectrum of a dielectric layer included in a multilayer ceramic capacitor according to an embodiment of the present invention.
4B is a partially enlarged view of the TEM-EDS spectrum shown in FIG. 4A.
FIG. 5A shows a TEM-EDS spectrum of a dielectric layer included in a multilayer ceramic capacitor according to a comparative example of the present invention.
FIG. 5B is a partially enlarged view of the TEM-EDS spectrum shown in FIG. 5A.
FIG. 6 shows the relationship between the content of Re contained in the dielectric layer (the main component contained in the dielectric layer (Ba in the case of barium titanate is 100 mol%)) and the IR of the multilayer ceramic capacitor. FIG.

Overall Configuration of Multilayer Ceramic Capacitor First, the overall configuration of a multilayer ceramic capacitor will be described as an embodiment of an electronic component according to the present invention.

  As shown in FIG. 1, the multilayer ceramic capacitor 2 according to this embodiment includes an element body 4 (hereinafter referred to as a capacitor element body 4), a first terminal electrode 6, and a second terminal electrode 8. The capacitor element body 4 includes a ceramic layer 10 (hereinafter referred to as a dielectric layer 10) and internal electrode layers 12, and the internal electrode layers 12 are alternately laminated between the dielectric layers 10. is there. One internal electrode layer 12 that is alternately stacked is electrically connected to the inside of the first terminal electrode 6 that is formed outside the first end 4 a of the capacitor element body 4. The other internal electrode layer 12 that is alternately stacked is electrically connected to the inside of the second terminal electrode 8 that is formed outside the second end 4 b of the capacitor element body 4.

  The internal electrode layer 12 contains at least one element of Re, Ru, Os, and Ir, and Ni. Preferably, the internal electrode layer 12 includes Re and Ni.

  The content ratio of Ni contained in the internal electrode layer 12 is preferably 80 mol% or more and less than 100 mol%, more preferably 87 mol% or more and less than 100 mol%, with respect to all metal components contained in the internal electrode layer 12. The total content of Re, Ru, Os, and Ir contained in the internal electrode layer 12 is preferably more than 0 mol% and not more than 20 mol%, more preferably, with respect to all metal components contained in the internal electrode layer 12. , 0.1 mol% or more and 13 mol% or less. If the Ni content is too high, the effects of the present invention tend to be small, and if it is too low, problems such as an increase in dielectric loss tanσ tend to increase. In addition, if the total content of Re, Ru, Os, and Ir is too large, there is a tendency that a disadvantage such as an increase in resistivity of the metal film occurs. In addition, various trace components, such as P, may be contained at about 0.1 mol% or less with respect to all metal components.

  Preferably, in the internal electrode layer 12, at least one element of Re, Ru, Os, and Ir and Ni form an alloy. Although it does not specifically limit as a composition (combination of metals) of an alloy, Ni-Re, Ni-Ru, Ni-Os, Ni-Ir etc. are mentioned. Preferably, in the internal electrode layer 12, Re and Ni form an alloy. In addition, you may use the alloy comprised from the said 3 or more types of metal type containing Ni as a electrically conductive material. Further, the conductive material particles constituting the internal electrode layer 12 are not necessarily an alloy. For example, the particle | grains comprised from the said metal alone, or the particle | grains comprised from the several metal layer comprised by the said metal alone may be sufficient.

  The thickness of the internal electrode layer 12 is not particularly limited, but is preferably 0.1 to 1 μm.

  The main component of the dielectric layer 10 (ceramic layer) is not particularly limited, and examples thereof include dielectric materials such as calcium titanate, strontium titanate and / or barium titanate. The thickness of each dielectric layer 10 is not particularly limited, but is generally several μm to several hundred μm. In particular, in this embodiment, the thickness is preferably 5 μm or less, more preferably 3 μm or less.

  The dielectric layer 10 is substantially free of Re, Ru, Os, and Ir. More specifically, the total content of Re, Ru, Os, and Ir contained in the dielectric layer 10 is relative to the main component element (Ba in the case of barium titanate) contained in the dielectric layer 10. , 0.5 mol% or less. The total content of Re, Ru, Os, and Ir contained in the dielectric layer 10 is preferably as small as possible, and most preferably 0.

  The material of the terminal electrodes 6 and 8 is not particularly limited, but usually copper, copper alloy, nickel, nickel alloy or the like is used. Alternatively, silver or an alloy of silver and palladium can also be used. Although the thickness of the terminal electrodes 6 and 8 is not specifically limited, Usually, it is about 10-50 micrometers.

  The shape and size of the multilayer ceramic capacitor 2 may be appropriately determined according to the purpose and application. When the multilayer ceramic capacitor 2 has a rectangular parallelepiped shape, the size is usually vertical (0.6 to 5.6 mm, preferably 0.6 to 3.2 mm) × horizontal (0.3 to 5.0 mm, preferably 0). 0.3 to 1.6 mm) × thickness (0.1 to 1.9 mm, preferably 0.3 to 1.6 mm).

Method for Manufacturing Multilayer Ceramic Capacitor 2 Next, an example of a method for manufacturing the multilayer ceramic capacitor 2 will be described.

(Formation of internal electrode layer film)
First, formation of the internal electrode layer film will be described. The internal electrode layer film constitutes the internal electrode layer 12 in the completed multilayer ceramic capacitor 2 (FIG. 1).

  First, as shown to FIG. 2A, the carrier sheet 20 as a 1st support sheet is prepared, and the peeling layer 22 is formed on it. Next, the internal electrode layer film 12 a is formed in a predetermined pattern on the surface of the release layer 22.

  The thickness of the formed internal electrode layer film 12a is preferably about 0.1 to 1 μm, more preferably about 0.1 to 0.5 μm. The internal electrode layer film 12a may be composed of a single layer, or may be composed of two or more layers having different compositions.

  A method for forming the internal electrode layer film 12a is not particularly limited, but a thin film method or a printing method is preferable.

(Thin film method)
The thin film method is not particularly limited, and examples thereof include a plating method, a sputtering method, and a vapor deposition method. Preferably, a sputtering method or an evaporation method is used.

  The target material used in the sputtering method includes at least one element of Re, Ru, Os, and Ir, and Ni. Preferably, a Ni-based alloy of at least one of Ni-Re, Ni-Ru, Ni-Os, and Ni-Ir described above is used as a target material. Note that the target material is not necessarily an alloy.

The sputtering conditions are not particularly limited, but the ultimate vacuum is preferably 10 ⁻² Pa or less, more preferably 10 ⁻³ Pa or less. The Ar gas introduction pressure is preferably 0.1 to 2 Pa, more preferably 0.3 to 0.8 Pa. The output is preferably 50 to 400 W, more preferably 100 to 300 W. The sputtering temperature is preferably 20 to 150 ° C, more preferably 20 to 120 ° C.

  The composition of the internal electrode layer film 12a formed by the sputtering method is the same as that of the target material.

A raw material used in the vapor deposition method is not particularly limited, but a metal (Re, Ru, Os, Ir and Ni) halide, a metal alkoxide, or the like is used. By vaporizing them and reducing them with, for example, H ₂ gas, the internal electrode layer film 12a is formed.

  The internal electrode layer film 12a formed by a thin film method (sputtering method or vapor deposition method) contains metal particles (alloy) having a crystallite size of preferably 10 to 100 nm, more preferably 30 to 80 nm. If the crystallite size is too small, inconveniences such as spheroidization and interruption occur, and if it is too large, inconveniences such as variations in film thickness occur.

(Printing method)
Although it does not specifically limit as a printing method, Screen printing method, gravure printing method, etc. are mentioned. When the internal electrode layer film 12a is formed by the printing method, it is performed as follows.

  First, another release layer (not shown) different from the release layer 22 shown in FIG. 2A is formed on a carrier sheet (not shown).

  Next, a Ni alloy film is formed on the release layer by the above-described thin film method (sputtering method or thin film method). Next, the formed Ni alloy film is peeled from the carrier sheet, and pulverized and classified with a ball mill or the like to obtain an alloy powder having an average particle size of 0.01 to 1 μm. Preferably, the alloy powder has a crystallite size of 10 to 100 nm. If the crystallite size is too small, inconveniences such as spheroidization and interruption occur, and if it is too large, inconveniences such as variations in film thickness occur.

  Next, this alloy powder is kneaded with an organic vehicle to form a paste, thereby obtaining a conductive paste for forming an internal electrode layer. The organic vehicle can be made of the same material as in the dielectric paste described later. The obtained conductive paste is formed in a predetermined pattern on the surface of the release layer 22 shown in FIG. 2A by a printing method. As a result, the internal electrode layer film 12a is obtained.

(Green sheet formation)
Next, formation of the green sheet will be described. The green sheet constitutes the dielectric layer 10 in the completed multilayer ceramic capacitor 2 (FIG. 1).

  First, a dielectric paste that is a material for a green sheet is prepared. The dielectric paste is usually composed of an organic solvent-based paste obtained by kneading a dielectric material and an organic vehicle, or an aqueous paste.

  The dielectric material is appropriately selected from various compounds that become composite oxides and oxides, such as carbonates, nitrates, hydroxides, organometallic compounds, and the like, and these can be used in combination. The dielectric material is usually used as a powder having an average particle size of about 0.1 to 3.0 μm. In order to form a very thin green sheet, it is desirable to use a powder having a particle size smaller than the thickness of the green sheet.

  An organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used in the organic vehicle is not particularly limited, and various ordinary binders such as ethyl cellulose, polyvinyl butyral, and acrylic resin are used, but a butyral resin such as polyvinyl butyral is preferably used.

  Moreover, the organic solvent used for the organic vehicle is not particularly limited, and organic solvents such as terpineol, butyl carbitol, acetone, and toluene are used. Further, the vehicle in the aqueous paste is obtained by dissolving a water-soluble binder in water. The water-soluble binder is not particularly limited, and polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, water-soluble acrylic resin, emulsion and the like are used. The content of each component in the dielectric paste is not particularly limited, and the normal content, for example, the binder may be about 1 to 5% by mass, and the solvent (or water) may be about 10 to 50% by mass.

  The dielectric paste may contain additives selected from various dispersants, plasticizers, dielectrics, glass frit, insulators and the like as required. However, the total content of these is preferably 10% by mass or less. When a butyral resin is used as the binder resin, the plasticizer preferably has a content of 25 to 100 parts by mass with respect to 100 parts by mass of the binder resin. If the amount of the plasticizer is too small, the green sheet tends to be brittle. If the amount is too large, the plasticizer oozes out and is difficult to handle.

  Next, as shown in FIG. 3A, the dielectric paste is applied onto a carrier sheet 30 (second support sheet) by a doctor blade method or the like to form a green sheet 10 a. The thickness of the green sheet 10a is preferably about 0.5 to 30 μm, more preferably about 0.5 to 10 μm. The green sheet 10a is dried after formation. The drying temperature of the green sheet 10a is preferably 50 to 100 ° C., and the drying time is preferably 1 to 5 minutes.

(Lamination process)
Next, the process of laminating | stacking the film | membrane 12a for internal electrode layers and the green sheet 10a which were formed by the above-mentioned method is demonstrated.

  As shown in FIG. 2A, first, an adhesive layer 28 is formed on the surface of the carrier sheet 26 (third support sheet) to prepare an adhesive layer transfer sheet. The carrier sheet 26 is composed of a sheet similar to the carrier sheets 20 and 30 described above.

  Next, as shown in FIG. 2B, the adhesive layer 28 formed on the carrier sheet 26 is pressed against the surface of the internal electrode layer film 12a and heated and pressurized. Thereafter, by peeling off the carrier sheet 26, the adhesive layer 28 is transferred to the surface of the internal electrode layer film 12a as shown in FIGS. 2C and 3A.

  The heating temperature during transfer is preferably 40 to 100 ° C., and the applied pressure is preferably 0.1 to 15 MPa. The pressurization may be a pressurization or a calender roll, but is preferably performed by a pair of rolls.

  Next, as shown in FIG. 3B, the internal electrode layer film 12a formed on the carrier sheet 20 is pressed against the surface of the green sheet 10a through the adhesive layer 28, and is heated and pressurized. Thereafter, by peeling off the carrier sheet 30, the internal electrode layer film 12a is transferred to the surface of the green sheet 10a as shown in FIG. 3C. The transfer method is the same as that for transferring the adhesive layer 28.

  A plurality of laminate units having a pair of green sheets 10a and internal electrode layer films 12a as shown in FIG. 3C are produced by the method described above. The laminate units are laminated to form a laminate in which a large number of internal electrode layer films 12a and green sheets 10a are alternately laminated. In addition, when performing this lamination | stacking, the carrier sheet 20 is peeled from each laminated body unit.

  Next, after laminating green sheets for outer layers on both end faces in the laminating direction of the laminate, final heating and pressurization are performed on the laminate. The pressure at the time of final pressurization is preferably 10 to 200 MPa. Moreover, 40-100 degreeC is preferable for heating temperature.

  Next, the laminate is cut into a predetermined size to form a green chip.

(Binder removal, firing, annealing)
Next, the binder removal process is performed on the green chip.

When Ni, which is a base metal, is used as the conductive material for forming the internal electrode layer as in the present invention, the binder removal treatment is preferably performed in an Air atmosphere or an N ₂ atmosphere. Further, as other binder removal conditions, the rate of temperature rise is preferably 5 to 300 ° C./hour, more preferably 10 to 50 ° C./hour. The holding temperature is preferably 200 to 400 ° C, more preferably 250 to 350 ° C. The temperature holding time is preferably 0.5 to 20 hours, more preferably 1 to 10 hours.

  Next, the green chip after the binder removal treatment is fired to form a fired body.

In the present embodiment, the green chip is baked in an atmosphere where the oxygen partial pressure is preferably 10 ⁻¹⁰ to 10 ⁻² Pa, more preferably 10 ⁻¹⁰ to 10 ⁻⁵ Pa. Further, the green chip is fired in a temperature atmosphere of preferably 1000 to 1300 ° C., more preferably 1150 to 1250 ° C.

  If the oxygen partial pressure during firing is too low, the conductive material (alloy) of the internal electrode layer film may be abnormally sintered and may be interrupted. Conversely, if the oxygen partial pressure during firing is too high, the internal electrode layer tends to oxidize. If the firing temperature is too low, the green chip will not be densified. On the other hand, if the firing temperature is too high, the internal electrodes are interrupted, the capacity-temperature characteristics are deteriorated due to the diffusion of the conductive material, and the dielectric is reduced.

  In the present embodiment, these problems can be prevented by firing the green chip in the above atmosphere. That is, by firing in the above atmosphere, it is possible to suppress grain growth and spheroidization of the conductive material (Ni-based alloy) while increasing the sintering start temperature of the conductive material (Ni-based alloy). As a result, the internal electrode layer can be formed continuously and without interruption, and a reduction in the capacitance of the capacitor can be suppressed.

As other firing conditions, the rate of temperature rise is preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour. The temperature holding time is preferably 0.5 to 8 hours, more preferably 1 to 3 hours. The cooling rate is preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour. The firing atmosphere is preferably a reducing atmosphere. As the atmospheric gas, for example, it is preferable to use a mixed gas of N ₂ and H ₂ in a wet (humidified) state.

  Next, the fired body obtained after firing the green chip is annealed to form the capacitor element body 4 (FIG. 1). Annealing is a process for reoxidizing the dielectric layer. By this annealing treatment, the IR of the capacitor can be improved and the IR accelerated life can be extended.

In this embodiment, it is preferable to anneal the fired body under an oxygen partial pressure higher than the reducing atmosphere during firing. Specifically, the fired body is annealed in an atmosphere where the oxygen partial pressure is preferably more than 0.00061 Pa and less than 1.3 Pa, more preferably 10 ^{−3 to 1} Pa, and still more preferably 0.0015 to 0.57 Pa. To do. The holding temperature or maximum temperature during annealing is preferably more than 600 ° C. and less than 1100 ° C., more preferably 700 ° C. or more and less than 1100 ° C., and further preferably 900 ° C. or more and less than 1100 ° C.

  In the present embodiment, the ceramic of the dielectric layer can be sufficiently reoxidized by annealing the fired body in the above atmosphere, and Re, Ru, Os, and Ir contained in the internal electrode layer are oxidized. Thus, diffusion into the dielectric layer can be suppressed. As a result, in the completed capacitor, the total content of Re, Ru, Os, and Ir contained in the dielectric layer is compared to the main component element (Ba in the case of barium titanate) contained in the dielectric layer. And 0.5 mol% or less. That is, Re, Ru, Os, and Ir can be substantially not included in the dielectric layer. As a result, the capacitor IR does not deteriorate.

  If the oxygen partial pressure during annealing is too low, the reoxidation of the dielectric layer becomes insufficient and the IR characteristics deteriorate. Also, tan δ increases due to insufficient annealing. Conversely, if the oxygen partial pressure is too high, the internal electrode layer film tends to oxidize. Further, if the holding temperature at the time of annealing is less than the above range, the re-oxidation of the dielectric material becomes insufficient, the IR becomes low, and tan δ increases. Conversely, when the holding temperature during annealing exceeds the above range, Ni of the internal electrode is oxidized and the capacitance of the capacitor is lowered. Furthermore, Re, Ru, Os, and Ir are oxidized and diffused into the dielectric layer, IR deteriorates, and tan δ increases. In the present embodiment, these problems can be prevented by annealing the fired body in the above atmosphere.

As other annealing conditions, the temperature holding time is preferably 0.5 to 4 hours, more preferably 1 to 3 hours. 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 order to humidify the N ₂ gas, for example, a wetter or the like may be used. In this case, the water temperature is preferably about 0 to 75 ° C.

    Note that the above-described binder removal processing, firing, and annealing may be performed continuously or independently.

Next, the obtained capacitor element body 4 (FIG. 1) is subjected to end surface polishing by, for example, barrel polishing or sand plast. Next, the terminal electrode paste is baked on each end face to form the first terminal electrode 6 and the second terminal electrode 8. The terminal electrode paste is baked, for example, in a humidified mixed gas of N ₂ and H ₂ . The temperature of the mixed gas at that time is preferably 600 to 800 ° C., and the heating time is preferably about 10 minutes to 1 hour. Then, if necessary, plating or the like is performed on the terminal electrodes 6 and 8 to form a pad layer. In addition, what is necessary is just to prepare the paste for terminal electrodes like the above-mentioned electrode paste.

  The multilayer ceramic capacitor 2 manufactured in this way is mounted on a printed circuit board by soldering or the like and used for various electronic devices.

In this embodiment, when the fired body is annealed, at least one element of Re, Ru, Os, and Ir contained in the internal electrode layer (internal electrode layer film) is converted into the internal electrode layer (internal electrode layer). Diffusion into the dielectric layer (green sheet) adjacent to the layer film) can be prevented. As a result, in the completed multilayer ceramic capacitor 2 (FIG. 1), the dielectric layer 10 does not substantially contain Re, Ru, Os, and Ir. Therefore, the deterioration of the IR of the multilayer ceramic capacitor 2 can be prevented. In other words, the total content of Re, Ru, Os, and Ir contained in the dielectric layer 10 is 0 with respect to the main component element (Ba in the case of barium titanate) contained in the dielectric layer 10. By limiting to 5 mol% or less, the deterioration of the IR of the multilayer ceramic capacitor 2 can be prevented.
Further, the internal electrode layer 12 contains not only Ni but also at least one element of Re, Ru, Os, and Ir having a melting point higher than Ni as a conductive material, so that the sintering temperature of the conductive material is increased. It rises and approaches the sintering temperature of the dielectric powder. As a result, cracking and peeling of the internal electrode layer 12 after sintering can be prevented, and defective sintering of the dielectric powder can be prevented.

In this embodiment, it is preferably more than 0.00061 Pa and less than 1.3 Pa, more preferably 10 ^{−3 to 1} Pa, still more preferably 0.0015 to 0.57 Pa, and the temperature is preferably more than 600 ° C. and less than 1100 ° C. More preferably, the fired body is annealed in an annealing atmosphere of 700 ° C. or higher and lower than 1100 ° C., more preferably 900 ° C. or higher and lower than 1100 ° C. As a result, Re, Ru, Os, and Ir contained in the internal electrode layer 12 can be prevented from diffusing into the dielectric layer 10. Therefore, Re, Ru, Os, and Ir can be substantially not included in the dielectric layer 10. As a result, IR degradation of the multilayer ceramic capacitor 2 can be prevented.

  Further, by annealing the fired body in the above atmosphere, the dielectric layer 10 is reoxidized, semiconductorization is prevented, and IR can be increased.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in various aspects. .

  For example, the alloy powder (conductive material) included in the conductive paste for the internal electrode layer may be formed directly by the CVD method (chemical vapor deposition method) instead of by pulverizing the alloy film. Also in this case, the same effect as the above embodiment can be obtained. By producing the alloy powder by the CVD method, the average particle diameter of the alloy powder can be precisely controlled, and the particle size distribution of the alloy powder can be sharpened. The average particle size and composition of the alloy powder can be controlled by the flow rate of the carrier gas carrying the vaporized raw material, the reaction temperature, the amount ratio of the raw material to be reacted, and the like.

  Further, the present invention is not limited to the multilayer ceramic capacitor but can be applied to other electronic components. Examples of other electronic components include, but are not limited to, piezoelectric elements, chip inductors, chip varistors, chip thermistors, chip resistors, and other surface mount (SMD) chip type electronic components.

  Hereinafter, the present invention will be described based on further detailed examples, but the present invention is not limited to these examples.

Example 1
First, a conductive material (alloy powder) for an internal electrode layer was manufactured by a CVD method. Ni chloride and Re chloride were used as raw materials for the conductive material. The crucible charged with Ni chloride and the crucible charged with Re chloride were placed in the raw material vaporization section of the CVD apparatus to vaporize Ni chloride and Re chloride. The vaporized Ni chloride and Re chloride fine particles were transported to the reaction part of the CVD apparatus by N ₂ as a carrier gas. The flow rate of the carrier gas was 3 L / min. The reaction part was heated to 1100 ° C., and the reduction reaction of Ni chloride and Re chloride occurred by H ₂ gas as the reducing gas supplied to the reaction part at 5 L / min, and Ni—Re alloy particles were generated. . The produced Ni—Re alloy particles were cooled together with the carrier gas in the cooling section, then discharged from the reaction vessel, and collected by a collection device.

  The obtained conductive material (Ni—Re alloy powder) had an average particle diameter of 300 nm, and the Re content in the alloy powder was about 20 mol% with respect to the entire alloy powder.

20 parts by weight of BaTiO ₃ powder (BT-005 / Sakai Chemical Industry Co., Ltd.) having an average particle diameter of 50 nm as co-material particles is added to 100 parts by weight of the conductive material, and further an organic vehicle (ethyl cellulose resin as a binder resin). 4.5 parts by weight of terpineol dissolved in 228 parts by weight) was added and kneaded with three rolls to form a slurry to form a conductive paste for forming an internal electrode layer film.

Next, BaTiO ₃ powder (BT-02 / Sakai Chemical Industry Co., Ltd.), MgCO ₃ , MnCO ₃ , (Ba _0.6 Ca _0.4 ) SiO ₃ and rare earth (Gd ₂ O ₃ , Tb ₄ O ₇₎ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , Lu ₂ O ₃ , Y ₂ O ₃ ) A dielectric material was obtained by mixing and drying. The average particle diameter of these raw material powders was 0.1 to 1 μm. (Ba _0.6 Ca _0.4 ) SiO ₃ was prepared by wet-mixing BaCO ₃ , CaCO ₃ and SiO ₂ with a ball mill, followed by drying and firing in the air using a ball mill.

  Next, in order to make the obtained dielectric material into a paste, an organic vehicle was added to the dielectric material and mixed with a ball mill to obtain a dielectric paste. The organic vehicle is based on 100 parts by mass of the dielectric material, polyvinyl butyral: 6 parts by mass as a binder, bis (2-ethylhexyl) phthalate (DOP): 3 parts by mass, ethyl acetate: 55 parts by mass, toluene: The blending ratio is 10 parts by mass and 0.5 parts by mass of paraffin as a release agent.

  Next, the dielectric paste diluted with ethanol / toluene (55/10) twice by weight was used as a release layer paste.

  Next, a paste similar to the above-described dielectric paste was prepared except that it did not contain dielectric particles and a release agent, and this was diluted 4 times by weight with toluene. In this way, an adhesive layer paste was produced.

  Next, using the dielectric paste, a green sheet 10a having a thickness of 1.0 μm was formed on a PET film (second support sheet) using a wire bar coater (FIG. 3A).

  Next, the release layer paste was applied and dried on another PET film (first support sheet) with a wire bar coater to form a release layer having a thickness of 0.3 μm.

  Next, as shown in FIG. 2A, an internal electrode layer film 12a having a predetermined pattern was formed on the surface of the release layer 22 by screen printing using the above conductive paste. The thickness of the internal electrode layer film 12a after drying was 0.5 μm.

  Next, as shown in FIG. 2A, the above adhesive layer paste is applied and dried by a wire bar coater on another PET film (third support sheet) whose surface has been subjected to a release treatment with a silicone resin. As a result, an adhesive layer 28 having a thickness of 0.2 μm was formed.

  Next, the adhesive layer 28 was transferred to the surface of the internal electrode layer film 12a by the method shown in FIGS. 2B and 2C. At the time of transfer, a pair of rolls were used, the pressure was 0.1 MPa, and the temperature was 80 ° C.

  Next, by the method shown in FIG. 3B, the internal electrode layer film 12a was adhered (transferred) to the surface of the green sheet 10a via the adhesive layer 28, thereby forming the laminate unit shown in FIG. 3C. A plurality of the laminate units were formed. At the time of transfer, a pair of rolls were used, the pressure was 0.1 MPa, and the temperature was 80 ° C.

  Next, the laminate units were laminated to form a laminate having a structure in which a large number of internal electrode layer films 12a and green sheets 10a were alternately laminated. The number of films for internal electrode layers included in the laminate was 21 layers. The lamination conditions were a pressure of 50 MPa and a heating temperature of 120 ° C. during pressurization. Next, the laminate was cut to a predetermined size to form a green chip.

  Next, the green chip was subjected to binder removal treatment in the following atmosphere.

Temperature increase rate: 5 to 300 ° C./hour,
Holding temperature: 200-400 ° C.
Retention time: 0.5-20 hours,
Atmospheric gas: humidified N ₂ gas.

  Next, the green chip after the binder removal treatment was fired under the following atmosphere to obtain a fired body.

Temperature increase rate: 5 to 500 ° C./hour,
Holding temperature: 1200 ° C,
Retention time: 0.5-8 hours,
Cooling rate: 50 to 500 ° C./hour,
Atmosphere gas: humidified mixed gas of N ₂ and H ₂ ,
Oxygen partial pressure: 10 ⁻⁷ Pa.

  Next, the fired body was annealed under the following atmosphere to form a capacitor element body.

Temperature increase rate: 200 to 300 ° C./hour,
Holding temperature: 700 ° C.
Retention time: 2 hours
Cooling rate: 300 ° C./hour,
Atmospheric gas: humidified N ₂ gas,
Oxygen partial pressure: 2.0 × 10 ⁻³ Pa.

The atmosphere gas was humidified using a wetter at a water temperature of 0 to 75 ° C.

Next, the end face of the capacitor element body was polished by sandblasting. Next, the external electrode paste was transferred to each end face. Next, the capacitor element body was baked at 800 ° C. for 10 minutes in a humidified N ₂ + H ₂ atmosphere to form an external electrode. In this way, a sample of the multilayer ceramic capacitor 2 having the configuration shown in FIG. 1 was obtained.

  The size of the obtained sample is 3.2 mm × 1.6 mm × 0.6 mm, the number of dielectric layers sandwiched between the internal electrode layers is 21, and the thickness is 1 μm. The thickness was 0.5 μm. The thickness (film thickness) of each layer was measured by observing with SEM.

Examples 2-13, Comparative Examples 1-4
In Examples 2 to 13 and Comparative Examples 1 to 4, the annealing atmosphere holding temperature and oxygen partial pressure were set to the values shown in Table 1 when the sintered body was annealed. Other than that was the same conditions as Example 1, and produced the multilayer ceramic capacitor of Examples 2-13 and Comparative Examples 1-4.

Evaluation 1
Measurement of Re Content Ratio For the multilayer ceramic capacitors obtained in Examples 1 to 13 and Comparative Examples 1 to 4, the composition of the dielectric constituting the dielectric layer (ceramic layer) was analyzed. More specifically, first, a multilayer ceramic capacitor as a sample was polished perpendicularly to the stacking direction to expose the dielectric layer. Next, composition analysis was performed on any 30 points of the dielectric ceramic layer sandwiched between the internal electrodes by energy dispersive X-ray analysis (TEM-EDS) using a transmission electron microscope, and the average value was stored in Re. The amount. Specifically, the Re content contained in the dielectric ceramic layer (Re amount (mol%) with respect to Ba as the main component of the dielectric ceramic phase) was determined. A 1 nm probe was used as an electron beam for analysis. The results are shown in FIGS. 4A, 4B, 5A, 5B and Table 1.

Measurement of electrical characteristic values The electrical characteristic values of the multilayer ceramic capacitors obtained in Examples 1 to 13 and Comparative Examples 1 to 4 were measured.

Specifically, the insulation resistance IR (unit: Ω) was measured. A IR variable measuring device was used for IR measurement. The measurement was performed under the conditions of room temperature, a measurement voltage of 6.3 V, and a voltage application time of 60 s. The larger the IR, the better. Specifically, IR is preferably 7.0 × 10 ⁸ Ω or more, more preferably 8.0 × 10 ⁸ Ω or more. The results are shown in Table 1.

  Capacitor and dielectric loss (tan δ) for a capacitor sample with a digital LCR meter (YHP 4274A) at a reference temperature of 25 ° C. and a frequency of 1 kHz and an input signal level (measurement voltage) of 1 Vrms. Was measured. The results are shown in Table 1.

Furthermore, the resistivity of the metal film having the same composition as the internal electrode layer was measured. Resistivity (unit: Ω · m) was measured by using a resistivity meter (Σ-5, manufactured by NPS), a sputtered film (before firing) formed on a glass substrate at 25 ° C. by DC 4 probe method. Measurement was performed at a current of 1 mA for 2 seconds. The resistivity is preferably 70 × 10 ⁻⁸ Ω · m or less. The results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 13 and Comparative Examples 1 to 4, the content of Re contained in the internal electrode layer is based on the total metal component (Ni—Re alloy) contained in the internal electrode layer. And 20 mol%.

  4A and 4B are TEM-EDS spectra obtained from one measurement point in the dielectric layer of Example 1. FIG. 5A and 5B are TEM-EDS spectra obtained from one measurement point in the dielectric layer of Comparative Example 4. FIG. 4A, 4B, 5A, and 5B, the horizontal axis represents the energy (KeV) of characteristic X-rays excited from atoms included in the dielectric layer, and the vertical axis represents excitation from atoms included in the dielectric layer. The detected intensity of the characteristic X-ray (value corresponding to the atomic content (mol%) in the dielectric layer). The Cu peak in the spectrum is derived from the support used for TEM observation, and each dielectric layer of Example 1 and Comparative Example 4 does not contain Cu.

As shown in FIGS. 4A and 5A, peaks derived from Ba and Ti of BaTiO ₃ as the main component of the dielectric layer were confirmed.

  As shown in FIGS. 4A and 4B, in Example 1, no peak was observed in the energy band corresponding to the Re characteristic X-ray. That is, Re was not detected at this measurement point (Re content was 0.5 mol% or less, which is the detection limit of the apparatus). Moreover, the spectrum similar to FIG. 4A and 4B was acquired also about the other measurement point in the dielectric material layer of Example 1. FIG.

  As shown in FIGS. 5A and 5B, in Comparative Example 4, a peak was observed in the energy band corresponding to the Re characteristic X-ray. From the peak intensity, 3.4 mol% of Re was detected at this measurement point. Further, at other measurement points in the dielectric ceramic layer of Comparative Example 1, a spectrum indicating the inclusion of Re was obtained as in FIGS. 5A and 5B.

As shown in Table 1, in Examples 1 to 13, the sintered body was annealed in an atmosphere having an oxygen partial pressure of 10 ^{−3 to 1} Pa and a holding temperature of 700 ° C. or higher and lower than 1100 ° C. Formed. As a result, in Examples 1 to 13, Re is below the lower detection limit concentration (the detection limit (lower limit value in TEM analysis is 0.5 mol%)), and Re is substantially detected in the dielectric ceramic layer. There wasn't.

On the other hand, in Comparative Examples 1 to 4, the oxygen partial pressure in the atmosphere for annealing the fired body was outside the range of 10 ^{−3 to 1} Pa, or outside the range of 700 ° C. or more and less than 1100 ° C. As a result, in Comparative Examples 1 to 4, Re was detected in the dielectric layer. That is, 0.5 mol% or more of Re content was recognized with respect to the dielectric layer main component Ba.

In Examples 1 to 13 in which Re is not substantially contained in the dielectric layer, the IR content is larger than those in Comparative Examples 1 to 4 in which the content of Re contained in the dielectric layer exceeds 0.5 mol%. (7.0 × 10 ⁸ Ω or more) was confirmed. On the other hand, IR was small in all the comparative examples (less than 7.0 × 10 ⁸ Ω).

In particular, in Examples 4 to 13 in which the fired body was annealed in an atmosphere having an oxygen partial pressure of 10 ^{−3 to 1} Pa and a holding temperature of 900 ° C. or higher and lower than 1100 ° C., compared to the other examples, IR Is large (8.0 × 10 ⁸ Ω or more).

  In Comparative Example 4, it was confirmed that the capacitance was small and tan δ was large compared to Examples 1-13.

  Regarding Examples 1 to 13, when the holding temperatures are equal to each other (Examples 1 and 2, Examples 4 and 5, Examples 6 and 7, Examples 8 and 9, Examples 11 to 13), It was confirmed that IR was larger in the example having a lower oxygen partial pressure. This is considered to be because the oxidation of Re and the diffusion into the dielectric layer are suppressed by lowering the oxygen partial pressure.

Examples 14-26, Comparative Examples 5-8
In Examples 14 to 26 and Comparative Examples 5 to 8, the Re content in the alloy powder included in the conductive material was about 5.0 mol% with respect to the entire alloy powder. In Examples 14 to 26 and Comparative Examples 5 to 8, the fired bodies were annealed in an atmosphere in which the holding temperature and the oxygen partial pressure were values shown in Table 2. Otherwise, a multilayer ceramic capacitor was produced under the same conditions as in Example 1. Moreover, the same evaluation as Example 1 was performed with respect to each capacitor. The results are shown in Table 2.

Examples 27-39, Comparative Examples 9-12
In Examples 27 to 39 and Comparative Examples 9 to 12, the Re content in the alloy powder was about 1.0 mol% with respect to the entire alloy powder. In Examples 27 to 39 and Comparative Examples 9 to 12, the fired bodies were annealed in an atmosphere in which the holding temperature and the oxygen partial pressure were values shown in Table 3. Otherwise, a multilayer ceramic capacitor was produced under the same conditions as in Example 1. Moreover, the same evaluation as Example 1 was performed with respect to each capacitor. The results are shown in Table 3.

Evaluation 2
As shown in Table 2, in Examples 14 to 26 and Comparative Examples 5 to 8, the content of Re contained in the internal electrode layer was based on the total metal component (Ni-Re alloy) contained in the internal electrode layer. And 5.0 mol%.

  As shown in Table 3, in Examples 27 to 39 and Comparative Examples 9 to 12, the content of Re contained in the internal electrode layer is based on the total metal component (Ni-Re alloy) contained in the internal electrode layer. 1.0 mol%.

  Despite the difference in the content of Re contained in the internal electrode layer, the same results as in Table 1 were confirmed in both Table 2 and Table 3.

That is, in Examples 14 to 39 in which the fired bodies were annealed in an atmosphere having an oxygen partial pressure of 10 ^{−3 to 1} Pa and a holding temperature of 700 ° C. or higher and lower than 1100 ° C., Re was not substantially contained in the dielectric layer. It was.

Further, in Examples 14 to 39 in which Re is not substantially contained in the dielectric layer, IR is higher than that in Comparative Examples 5 to 12 in which the content of Re contained in the dielectric layer exceeds 0.5 mol%. It was confirmed that it was large (7.0 × 10 ⁸ Ω or more).

In FIG. 6, the result of Comparative Examples 1-12 is shown. In the graph shown in FIG. 6, the horizontal axis indicates the content of Re contained in the dielectric layer of each comparative example (capacitor), and the vertical axis indicates the IR of the corresponding capacitor. In addition, the triangle mark, the square mark, and the circle mark in the graph mean comparative examples in which the content of Re contained in the internal electrode layer is 1.0 mol%, 5.0 mol%, and 20 mol%, respectively. . In all the examples shown in Tables 1 to 3, the Re content in the dielectric layer is below the detection limit (0.5 mol% or less), and the IR is 7.0 × 10 ⁸ Ω or more. Therefore, it is not shown in FIG.

  As shown in FIG. 6, regardless of the Re content in the internal electrode layer, it is confirmed that the IR rapidly decreases when the Re content in the dielectric layer exceeds 0.5 mol%. It was done. In addition, it was confirmed that the IR decreases as the content of Re contained in the dielectric layer increases.

Examples 40-42
The multilayer ceramic capacitors of Examples 40 to 42 were produced in the same manner as in Example 1 except that the Re content, the holding temperature in the annealing atmosphere, and the oxygen partial pressure contained in the internal electrode layers were set to the values shown in Table 4. Was made. In addition to the same evaluation as in Example 1, the electrode coverage and breakdown voltage were also evaluated for these samples. The results are shown in Table 4.

Measurement of electrode coverage The electrode coverage was measured by cutting a sample of a multilayer ceramic capacitor so that the electrode surface was exposed, observing the electrode surface with SEM, and performing image processing. The electrode coverage is preferably 80% or more, more preferably 90% or more.

Measurement of breakdown voltage The voltage value at a temperature rising speed of 1 V / s and a detection current of 2 mA was defined as a breakdown voltage. About the same lot, 30 pieces were measured and the average value was calculated | required. The breakdown voltage is preferably 90 V or higher, more preferably 100 V or higher.

Examples 43-45
Except for using Ru instead of Re contained in the internal electrode layer and setting the annealing atmosphere holding temperature and oxygen partial pressure to the values shown in Table 4, the same methods as in Example 1 were used. A multilayer ceramic capacitor was produced. In addition to the same evaluation as in Example 1, the electrode coverage and breakdown voltage were also evaluated for these samples. The results are shown in Table 4.

Example 46
The multilayer ceramic of Example 46 was the same as Example 1 except that Os was used instead of Re contained in the internal electrode layer, and the annealing atmosphere holding temperature and oxygen partial pressure were set to the values shown in Table 4. A capacitor was produced. In addition to the same evaluation as in Example 1, the electrode coverage and breakdown voltage were also evaluated for the sample of Example 46. The results are shown in Table 4.

Example 47
The laminated ceramic of Example 40 was prepared in the same manner as in Example 1 except that Ir was used instead of Re contained in the internal electrode layer and the annealing atmosphere holding temperature and oxygen partial pressure were set to the values shown in Table 4. A capacitor was produced. In addition to the same evaluation as in Example 1, the electrode coverage and breakdown voltage were also evaluated for the sample of Example 47. The results are shown in Table 4.

Evaluation 3
From the results of Examples 43 to 47, the same results as in Examples 1 to 39 and 40 to 42 were confirmed. That is, Ru, Os, and Ir are substantially contained in the dielectric layer by annealing the fired body in an atmosphere having an oxygen partial pressure of 10 ^{−3 to 1} Pa and a holding temperature of more than 600 ° C. and less than 1100 ° C. It was confirmed that it is not included in As a result, it was confirmed that the deterioration of the IR of the capacitor was prevented.

Evaluation 4
In Examples 40 to 42 and 47 in which Re and Ir are included in the internal electrode layer, IR is comparable to those in Examples 43 to 46 in which any of Ru and Os is included in the internal electrode layer. It was confirmed that the electrode coverage, breakdown voltage and capacitance were large. That is, since Re and Ir have a larger function of suppressing the spheroidization of the electrode than Ru and Os, the electrode coverage is increased and the capacitance is also increased. In addition, with respect to the breakdown voltage, since the spheroidization of the electrode can be suppressed, variations in the dielectric thickness can be suppressed, and as a result, the breakdown voltage can be increased.

  It was also confirmed that Examples 40 to 42 containing Re had higher electrode coverage, breakdown voltage, and capacitance than Example 47 containing Ir.

FIG. 1 is a schematic cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 2A is a cross-sectional view of a principal part showing a method for transferring a film for an internal electrode layer. FIG. 2B is a cross-sectional view illustrating the main part of the internal electrode layer film transfer method. FIG. 2C is a cross-sectional view of a principal part showing a method for transferring the film for the internal electrode layer. FIG. 3A is a sectional view of an essential part showing a method for transferring a film for an internal electrode layer. FIG. 3B is a cross-sectional view illustrating the main part of the internal electrode layer film transfer method. FIG. 3C is a cross-sectional view of a principal part showing a transfer method of the internal electrode layer film. FIG. 4A is a TEM-EDS spectrum of a dielectric layer included in the multilayer ceramic capacitor according to the example of the present invention. FIG. 4B is a partially enlarged view of the TEM-EDS spectrum shown in FIG. 4A. FIG. 5A is a TEM-EDS spectrum of a dielectric layer included in a multilayer ceramic capacitor according to a comparative example of the present invention. FIG. 5B is a partially enlarged view of the TEM-EDS spectrum shown in FIG. 5A. FIG. 6 is a diagram showing the relationship between the content of Re contained in the dielectric layer (Ba contained in the dielectric layer is 100 mol%) and the IR of the multilayer ceramic capacitor.

Explanation of symbols

2 ... Multilayer ceramic capacitor 4 ... Capacitor element body (element body)
6, 8 ... Terminal electrode 10 ... Dielectric layer (ceramic layer)
10a ... Green sheet 12 ... Internal electrode layer 12a ... Film for internal electrode layer 20 ... Carrier sheet (first support sheet)
22 ... Release layer 26 ... Carrier sheet (third support sheet)
28 ... Adhesive layer 30 ... Carrier sheet (second support sheet)

Claims (12)

An electronic component having an element body including an internal electrode layer and a ceramic layer,
The internal electrode layer includes at least one element of Re, Ru, Os, and Ir;
Ni, and
The electronic component, wherein the ceramic layer is substantially free of Re, Ru, Os, and Ir. The content of Ni contained in the internal electrode layer is 80 mol% or more and less than 100 mol% with respect to the total metal components contained in the internal electrode layer,
The total content of Re, Ru, Os, and Ir contained in the internal electrode layer is more than 0 mol% and 20 mol% or less with respect to all metal components contained in the internal electrode layer. Item 2. The electronic component according to Item 1. 3. The electronic component according to claim 1, wherein in the internal electrode layer, at least one element of Re, Ru, Os, and Ir and Ni form an alloy. A method for manufacturing the electronic component according to claim 1,
Forming a green chip having an internal electrode layer film;
Firing the green chip to form a fired body;
Annealing the fired body to form the element body in an atmosphere having an oxygen partial pressure of more than 6.1 × 10 ⁻⁴ Pa and less than 1.3 Pa and a temperature of more than 600 ° C. and less than 1100 ° C .; A method for manufacturing an electronic component, comprising: The element body is formed by annealing the fired body in an atmosphere having an oxygen partial pressure of more than 6.1 × 10 ⁻⁴ Pa and less than 1.3 Pa and a temperature of 900 ° C. or more and less than 1100 ° C. The manufacturing method of the electronic component of Claim 4. 6. The green chip is fired to form the fired body in an atmosphere having an oxygen partial pressure of 10 ⁻¹⁰ to 10 ⁻² Pa and a temperature of 1000 to 1300 ° C. 6. The manufacturing method of the electronic component of description. The method for manufacturing an electronic component according to claim 4, wherein the internal electrode layer film is formed by a thin film method. The method for manufacturing an electronic component according to claim 7, wherein the internal electrode layer film has a crystallite size of 10 to 100 nm. 9. The method of manufacturing an electronic component according to claim 7, wherein the internal electrode layer film is formed by a sputtering method or a vapor deposition method. The electronic component according to claim 4, wherein the internal electrode layer film is formed by a printing method using a conductive paste containing an alloy powder having an average particle size of 0.01 to 1 μm. Manufacturing method. The method for manufacturing an electronic component according to claim 10, wherein the alloy powder has a crystallite size of 10 to 100 nm. 12. The method of manufacturing an electronic component according to claim 10, wherein the alloy powder is formed by forming an alloy film by a thin film method and pulverizing the alloy film.

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