WO2023120309A1 - Method for producing electrolytic capacitor - Google Patents

Method for producing electrolytic capacitor Download PDF

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Publication number
WO2023120309A1
WO2023120309A1 PCT/JP2022/045965 JP2022045965W WO2023120309A1 WO 2023120309 A1 WO2023120309 A1 WO 2023120309A1 JP 2022045965 W JP2022045965 W JP 2022045965W WO 2023120309 A1 WO2023120309 A1 WO 2023120309A1
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Prior art keywords
conductive polymer
layer
anode body
anode
polymer layer
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PCT/JP2022/045965
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French (fr)
Japanese (ja)
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孝裕 小林
剛士 古川
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パナソニックＩｐマネジメント株式会社
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Publication of WO2023120309A1 publication Critical patent/WO2023120309A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/15—Solid electrolytic capacitors

Definitions

  • the present invention relates to a method for manufacturing an electrolytic capacitor.
  • Electrolytic capacitors have a low equivalent series resistance (ESR) and excellent frequency characteristics, so they are installed in various electronic devices. Electrolytic capacitors typically comprise a capacitor element comprising an anode portion and a cathode portion. The anode part includes a porous anode body, and a dielectric layer is formed on the surface of the anode body. The dielectric layer contacts the electrolyte. As an electrolyte, there is an electrolytic capacitor using a solid electrolyte such as a conductive polymer (see, for example, Patent Document 1).
  • Patent Document 2 discloses that (i) a first conductive polymer is added in the presence of a silane compound to the dielectric layer of the anode body on which the dielectric layer is formed. (ii) comprising a second conductive polymer and a basic compound on the first conductive polymer layer, and a first forming a second conductive polymer layer overlying at least a portion of the first conductive polymer layer.
  • the oxidizing agent and dopant used in polymerization easily combine with water, so a large amount of water remains in the polymer film. can.
  • the outer conductive polymer layer peels off due to vaporization and expansion of water, and the solid electrolyte layer tends to be poorly formed due to swelling.
  • one aspect of the present disclosure provides a porous anode body, a dielectric layer formed on the surface of the anode body, a solid electrolyte layer covering at least a portion of the dielectric layer, and the solid electrolyte and a cathode layer covering at least a part of the layer, the step of forming the solid electrolyte layer containing a conductive polymer on the surface of the anode body on which the dielectric layer is formed.
  • the step of forming the solid electrolyte layer includes impregnating the anode body with a first solution containing a first monomer that is a raw material of the first conductive polymer, and forming the first a first step of polymerizing one monomer to form a first conductive polymer layer covering the dielectric layer; a second step of impregnating and forming a second conductive polymer layer covering the first conductive polymer layer, wherein the second step includes subjecting the anode body to a reduced pressure treatment;
  • the present invention relates to a method for manufacturing an electrolytic capacitor.
  • an electrolytic capacitor comprising a solid electrolyte layer formed of a plurality of conductive polymer layers, it is possible to improve the adhesion between the conductive polymer layers, so that swelling of the conductive polymer layer due to vaporization expansion of moisture etc. can be prevented. Defects due to are reduced.
  • FIG. 1 is a cross-sectional view schematically showing an example of a capacitor element of an electrolytic capacitor manufactured by a manufacturing method according to an embodiment of the present disclosure
  • FIG. 1 is a cross-sectional view schematically showing an electrolytic capacitor manufactured by a manufacturing method according to an embodiment of the present disclosure
  • FIG. 4 is a flow chart showing an example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to the present embodiment.
  • 4 is a flow chart showing another example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to the present embodiment.
  • the present disclosure encompasses a combination of matters described in two or more claims arbitrarily selected from the multiple claims described in the attached claims. In other words, as long as there is no technical contradiction, the items described in two or more claims arbitrarily selected from the multiple claims described in the attached claims can be combined.
  • a method for manufacturing an electrolytic capacitor according to an embodiment of the present disclosure includes a porous anode body, a dielectric layer formed on the surface of the anode body, a solid electrolyte layer covering at least a portion of the dielectric layer, a solid a cathode layer covering at least a portion of the electrolyte layer, the method comprising the step of forming a solid electrolyte layer containing a conductive polymer on the surface of an anode body having a dielectric layer formed thereon.
  • the anode body is impregnated with a first solution containing a first monomer as a raw material of the first conductive polymer, and the first monomer is polymerized on the surface of the dielectric layer to form a dielectric layer.
  • an oligomer is contained in a 1st monomer.
  • a dispersion of a conductive polymer includes a solution of a conductive polymer.
  • the second step includes depressurizing the anode body.
  • the depressurization treatment may be performed before drying the second dispersion impregnated in the anode body, and there are no particular limitations on the depressurization start time, treatment time and method.
  • the anode body may be immersed in the second dispersion under reduced pressure and released to atmospheric pressure to impregnate the second dispersion into the anode body, or the anode body may be impregnated with the second dispersion.
  • the second dispersion may be impregnated into the anode body by pulling up the body and decompressing and releasing the anode body with the second dispersion adhered thereon to the atmospheric pressure.
  • the depressurization process is started in a state in which the fluidity of the second conductive polymer in the second dispersion is sufficiently ensured.
  • the decompression treatment may be started when the content of the second conductive polymer in the second dispersion impregnated in the anode body is 90% by mass or less, 75% by mass or less, or 50% by mass or less.
  • the surface of the first conductive polymer layer (eg, chemically polymerized layer) formed by polymerization has fine irregularities when viewed microscopically.
  • the second conductive polymer can penetrate deep into the recesses on the surface of the first conductive polymer layer, and the second conductive polymer layer and the first conductive polymer layer can be separated. Adhesion can be improved.
  • the formation of voids in the concave portion that is the starting point of swelling is also suppressed. This suppresses the second conductive polymer layer from peeling off from the first conductive polymer layer and causing swelling.
  • the reduced pressure treatment can prevent swelling of the dispersion liquid containing the second conductive polymer (polymer dispersion), which tends to accumulate in the lower portion of the anode body, during drying, and suppress variation in characteristics due to insufficient adhesion.
  • the pressure during the decompression process should be at least lower than the atmospheric pressure.
  • the pressure during the decompression process may be, for example, a pressure lower than the atmospheric pressure by 50 kPa or more, or a pressure lower than the atmospheric pressure by 100 kPa or more.
  • the treatment time for reducing pressure may be 1 minute or more and 10 minutes or less, or may be 2 minutes or more and 10 minutes or less.
  • the anode body may be impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the second dispersion.
  • the cation contained in the basic compound suppresses the repulsion of the anionic dopant contained in the conductive polymer, thereby increasing the adhesion between the second conductive polymer layer and the first conductive polymer layer.
  • the surface of the first conductive polymer layer is precoated with a basic compound layer, and the second conductive polymer layer is formed on the surface of the first conductive polymer layer precoated with the basic compound layer. This further improves the adhesion of the second conductive polymer layer to the first conductive polymer layer. This further suppresses the second conductive polymer layer from peeling off from the first conductive polymer layer and causing swelling.
  • a third solution or third dispersion containing a third conductive polymer (hereinafter, unless otherwise specified, “third solution or third dispersion liquid” is simply referred to as “third dispersion liquid”, and the description of the third solution is omitted.) is impregnated into the anode body to form a third conductive polymer layer. good too.
  • the anode body may be impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the third dispersion.
  • the surface of the second conductive polymer layer is pre-coated with a basic compound layer, and the third conductive polymer layer is formed on the surface of the second conductive polymer layer pre-coated with the basic compound layer.
  • the adhesion of the third conductive polymer layer to the second conductive polymer layer is improved, and as a result, the third conductive polymer layer is peeled off from the second conductive polymer layer, causing swelling. is suppressed.
  • the second conductive polymer layer when forming the second conductive polymer layer on the first conductive polymer layer, if the surface of the first conductive polymer layer is pre-coated with a layer containing a basic compound, part of the basic compound dissolves into the second dispersion, increasing the viscosity of the second dispersion.
  • the recesses on the surface of the first conductive polymer layer are particularly fine compared to other conductive polymer layers formed thereon, and the recesses between the second conductive polymer layer and the first conductive polymer layer are particularly fine.
  • the surface of the first conductive polymer layer is pre-coated with a basic compound so that the second conductive polymer can easily penetrate deep into the recesses on the surface of the first conductive polymer layer.
  • the second conductive polymer layer may be formed directly on the first conductive polymer layer.
  • the second conductive polymer layer is directly formed without precoating the surface of the first conductive polymer layer with a basic compound. is preferred.
  • the anode body is not impregnated with a solution or solvent containing a basic compound in the second step.
  • the surface of the conductive polymer layer may not be precoated with a basic compound.
  • the solid electrolyte layer may be formed of two conductive polymer layers, or may be formed of three or more conductive polymer layers.
  • amine compounds or amidine compounds such as N,N-dimethyloctylamine and 1,8-diaminooctane can be preferably used.
  • a first conductive polymer contained in the first conductive polymer layer, a second conductive polymer contained in the second conductive polymer layer, and a third conductive polymer contained in the third conductive polymer layer may each contain the same or different monomeric units.
  • the third conductive polymer preferably contains the same monomer units as those constituting the second conductive polymer.
  • a thick conductive polymer layer having the same monomer skeleton can be formed.
  • FIG. 1 is a cross-sectional view schematically showing an example of a capacitor element of an electrolytic capacitor manufactured by the manufacturing method according to this embodiment.
  • FIG. 2 is a schematic cross-sectional view of an electrolytic capacitor manufactured by the manufacturing method according to this embodiment.
  • Electrolytic capacitor 20 is electrically connected to capacitor element 10 having anode portion 6 and cathode portion 7, exterior body 11 that seals capacitor element 10, and anode section 6, and a portion of exterior body 11 extends from An exposed anode lead terminal 13 and a cathode lead terminal 14 electrically connected to the cathode section 7 and partly exposed from the exterior body 11 are provided.
  • Anode section 6 has anode body 1 and anode wire 2 .
  • a dielectric layer 3 is formed on the surface of the anode body.
  • Cathode portion 7 has solid electrolyte layer 4 covering at least part of dielectric layer 3 and cathode layer 5 covering at least part of the surface of solid electrolyte layer 4 .
  • capacitor element 10 will be described in detail, taking as an example a case in which a solid electrolyte layer is provided as an electrolyte.
  • Anode section 6 has anode body 1 and anode wire 2 extending from one surface of anode body 1 and electrically connected to anode lead terminal 13 .
  • Anode body 1 is, for example, a cuboid porous sintered body obtained by sintering metal particles.
  • the metal particles particles of valve action metals such as titanium (Ti), tantalum (Ta) and niobium (Nb) are used.
  • One or two or more kinds of metal particles are used in anode body 1 .
  • the metal particles may be an alloy of two or more metals.
  • an alloy containing a valve action metal and silicon, vanadium, boron, or the like can be used.
  • a compound containing a valve action metal and a typical element such as nitrogen may also be used.
  • the alloy of the valve action metal is mainly composed of the valve action metal, and contains, for example, 50 atomic % or more of the valve action metal.
  • the anode wire 2 is made of a conductive material.
  • the material of the anode wire 2 is not particularly limited, and examples thereof include the above-described valve action metals, copper, aluminum, aluminum alloys, and the like.
  • the materials constituting anode body 1 and anode wire 2 may be of the same type or of different types.
  • Anode wire 2 has a first portion 2 a embedded inside anode body 1 from one surface of anode body 1 and a second portion 2 b extending from the one surface of anode body 1 .
  • the cross-sectional shape of the anode wire 2 is not particularly limited, and may be circular, track-shaped (a shape consisting of mutually parallel straight lines and two curved lines connecting the ends of these straight lines), elliptical, rectangular, polygonal, and the like. be done.
  • the anode portion 6 is produced, for example, by embedding the first portion 2a in the powder of the first metal particles, molding the first portion 2a into a rectangular parallelepiped shape, and sintering the first portion. As a result, the second portion 2b of the anode wire 2 is pulled out from one surface of the anode body 1 so as to be erected. The second portion 2b is joined to the anode lead terminal 13 by welding or the like, so that the anode wire 2 and the anode lead terminal 13 are electrically connected.
  • the welding method is not particularly limited, and includes resistance welding, laser welding, and the like.
  • a dielectric layer 3 is formed on the surface of the anode body 1 .
  • the dielectric layer 3 is made of metal oxide, for example.
  • a method for forming a layer containing a metal oxide on the surface of anode body 1 for example, anode body 1 is immersed in a chemical solution to anodize the surface of anode body 1, or anode body 1 is immersed in oxygen.
  • the dielectric layer 3 is not limited to the layer containing the above-mentioned metal oxide, and may have insulating properties.
  • the cathode section 7 has a solid electrolyte layer 4 and a cathode layer 5 covering the solid electrolyte layer 4 .
  • Solid electrolyte layer 4 is formed to cover at least a portion of dielectric layer 3 .
  • a manganese compound or a conductive polymer is used for the solid electrolyte layer 4 .
  • conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, and the like. These may be used alone, or may be used in combination. Also, the conductive polymer may be a copolymer of two or more monomers. Polythiophene, polyaniline, and polypyrrole may be used from the viewpoint of excellent conductivity. In particular, polypyrrole may be used because of its excellent water repellency.
  • the solid electrolyte layer 4 containing the conductive polymer is composed of two or more solid electrolyte layers, for example, a first conductive polymer layer covering the dielectric layer 3 and a first conductive polymer layer covering the first conductive polymer layer.
  • a second conductive polymer layer is included.
  • the composition and formation method (polymerization method) of the conductive polymer used for each layer may be different.
  • the first conductive polymer layer may be formed by polymerizing raw material monomers on the dielectric layer 3 .
  • the second conductive polymer layer may be formed by applying a liquid containing the conductive polymer to the dielectric layer 3 .
  • polypyrrole, polythiophene, polyfuran, polyaniline, etc. mean polymers having polypyrrole, polythiophene, polyfuran, polyaniline, etc. as a basic skeleton, respectively. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline, etc. may also include their respective derivatives.
  • polythiophenes include poly(3,4-ethylenedioxythiophene) and the like.
  • dopants may be added to the polymerization liquid, solution or dispersion of the conductive polymer for forming the conductive polymer, in order to improve the conductivity of the conductive polymer.
  • the dopant is not particularly limited, examples include naphthalenesulfonic acid, p-toluenesulfonic acid, polystyrenesulfonic acid and the like.
  • the average particle diameter D50 of the particles is, for example, 0.01 ⁇ m or more and 0.5 ⁇ m or less. If the average particle diameter D50 of the particles is within this range, the particles can easily penetrate into the interior of anode body 1 .
  • the cathode layer 5 has, for example, a carbon layer 5a formed to cover the solid electrolyte layer 4 and a metal paste layer 5b formed on the surface of the carbon layer 5a.
  • the carbon layer 5a contains a conductive carbon material such as graphite and a resin.
  • the metal paste layer 5b contains, for example, metal particles (for example, silver) and resin.
  • the structure of the cathode layer 5 is not limited to this structure.
  • the configuration of the cathode layer 5 may be any configuration as long as it has a current collecting function.
  • a basic compound When the solid electrolyte layer 4 is composed of a plurality of conductive polymer layers, a basic compound may be interposed between the conductive polymer layers in order to improve adhesion between the conductive polymer layers.
  • Basic compounds include inorganic bases such as ammonia, as well as organic bases such as amine compounds.
  • amine compounds are preferable from the viewpoint of being highly effective in suppressing a decrease in conductivity. Any of a primary amine, a secondary amine, and a tertiary amine may be sufficient as an amine compound.
  • Amine compounds include aliphatic amines and cyclic amines.
  • a basic compound may be used individually by 1 type, and may be used in combination of 2 or more types.
  • Aliphatic amines include alkylamines such as ethylamine, diethylamine, triethylamine, N,N-dimethyloctylamine and N,N-diethyloctylamine; alkanolamines such as ethanolamine, 2-ethylaminoethanol and diethanolamine; -ethylethylenediamine, alkylenediamine such as 1,8-diaminooctane, and the like.
  • Alicyclic amines include, for example, aminocyclohexane, diaminocyclohexane, and isophoronediamine. Examples of aromatic amines include aniline and toluidine.
  • Cyclic amines are preferably cyclic amines having a 5- to 8-membered (preferably 5- or 6-membered) nitrogen-containing ring skeleton, such as pyrrole, imidazoline, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, and triazine. Cyclic amines may have one nitrogen-containing ring skeleton, or two or more (eg, two or three). When the cyclic amine has more than one nitrogen-containing ring skeleton, the nitrogen-containing ring skeletons may be the same or different.
  • the amine compound may have a substituent as necessary. Whether the conductive polymer layer contains an amine compound can be analyzed, for example, by gas chromatography (GC).
  • GC gas chromatography
  • Anode lead terminal 13 is electrically connected to anode body 1 through second portion 2 b of anode wire 2 .
  • the material of anode lead terminal 13 is not particularly limited as long as it is electrochemically and chemically stable and has conductivity.
  • the anode lead terminal 13 may be made of metal such as copper, or may be made of non-metal.
  • the shape is not particularly limited as long as it is flat.
  • the thickness of anode lead terminal 13 (the distance between the main surfaces of anode lead terminal 13) may be 25 ⁇ m or more and 200 ⁇ m or less, and may be 25 ⁇ m or more and 100 ⁇ m or less, from the viewpoint of height reduction.
  • anode lead terminal 13 may be joined to the anode wire 2 with a conductive adhesive or solder, or may be joined to the anode wire 2 by resistance welding or laser welding.
  • the other end of anode lead terminal 13 is led out of package 11 and exposed from package 11 .
  • the conductive adhesive is, for example, a mixture of a thermosetting resin, which will be described later, and carbon particles or metal particles.
  • the cathode lead terminal 14 is electrically connected to the cathode portion 7 at the joint portion 14a.
  • the junction portion 14 a is a portion where the cathode lead terminal 14 overlaps the cathode layer 5 .
  • the cathode lead terminal 14 is joined to the cathode layer 5 via a conductive adhesive 8, for example.
  • One end of the cathode lead terminal 14 constitutes, for example, a part of the joint portion 14 a and is arranged inside the exterior body 11 .
  • the other end of the cathode lead terminal 14 is led out to the outside. Therefore, a portion including the other end of cathode lead terminal 14 is exposed from exterior body 11 .
  • the material of the cathode lead terminal 14 is also not particularly limited as long as it is electrochemically and chemically stable and has conductivity.
  • the cathode lead terminal 14 may be made of metal such as copper, or may be made of non-metal.
  • the shape is not particularly limited, either, and for example, it is long and flat.
  • the thickness of the cathode lead terminal 14 may be 25 ⁇ m or more and 200 ⁇ m or less, or may be 25 ⁇ m or more and 100 ⁇ m or less, from the viewpoint of height reduction.
  • the exterior body 11 is provided to electrically insulate the anode lead terminal 13 and the cathode lead terminal 14, and is made of an insulating material (sheath material).
  • the exterior body material includes, for example, thermosetting resin.
  • thermosetting resins include epoxy resins, phenol resins, silicone resins, melamine resins, urea resins, alkyd resins, polyurethanes, polyimides, unsaturated polyesters, and the like.
  • Capacitor Element Preparing Step First, a capacitor element is prepared.
  • the steps of preparing the capacitor element include, for example, preparing an anode body, covering at least part of the anode body with a dielectric layer, covering at least part of the dielectric layer with a solid electrolyte layer, and solid and covering at least a portion of the electrolyte layer with a carbon layer.
  • the step of preparing the capacitor element may further include the step of covering at least part of the carbon layer with a conductive resin layer.
  • anode body Preparing Step
  • a porous sintered body can be used as the anode body 1.
  • the valve-acting metal particles and the anode wire 2 are placed in a mold so that the first portion 2a is embedded in the valve-acting metal particles, pressure-molded, and then sintered to form an anode body, which is a porous body of the valve-acting metal.
  • An anode portion 6 containing 1 is obtained.
  • a first portion 2a of the anode wire is embedded inside the porous sintered body from one side thereof.
  • the pressure during pressure molding is not particularly limited. Sintering is preferably performed under reduced pressure.
  • the valve metal particles may be mixed with a binder such as polyacrylic carbonate.
  • valve action metal particles are usually pressure-molded and sintered using a mold with a rectangular parallelepiped internal space.
  • shape of anode body 1 after sintering is also a rectangular parallelepiped and has a plurality of main surfaces.
  • anode body 1 is subjected to chemical conversion treatment, and at least a portion of anode body 1 is covered with dielectric layer 3 .
  • the anode body 1 is immersed in an anodizing tank filled with an electrolytic aqueous solution (for example, a phosphoric acid aqueous solution), the second portion 2b of the anode wire 2 is connected to the anode body in the anodizing tank, and anodization is performed.
  • an electrolytic aqueous solution is not limited to the phosphoric acid aqueous solution, and nitric acid, acetic acid, sulfuric acid, or the like can be used.
  • Step of Forming Solid Electrolyte Layer Subsequently, at least part of the dielectric layer 3 is covered with the solid electrolyte layer 4 .
  • Capacitor element 10 including anode body 1 , dielectric layer 3 , and solid electrolyte layer 4 is thus obtained.
  • a solid electrolyte layer 4 including a plurality of conductive polymer layers may be formed.
  • the anode body is impregnated with a solution containing a first monomer as a raw material of the first conductive polymer, and the first monomer is polymerized on the surface of the dielectric layer to form the dielectric layer.
  • FIG. 3 is a flow chart showing an example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to this embodiment.
  • a first conductive polymer layer is formed on anode body 1 having dielectric layer 3 formed thereon by impregnating with a monomer or oligomer and then polymerizing the monomer or oligomer by chemical polymerization or electrolytic polymerization.
  • the first conductive polymer may contain a dopant.
  • the conductive polymer and dopant may be selected from those exemplified for the solid electrolyte layer 4, respectively.
  • the raw material monomer of the first conductive polymer is oxidatively polymerized (so-called “in situ polymerization”) above the dielectric layer 3 to form the dielectric layer 3.
  • a first conductive polymer layer is formed thereover.
  • the surface of the first conductive polymer layer may have fine unevenness due to non-uniform polymerization reaction, non-uniform layer growth, and the like.
  • step (ii) first, the anode body is impregnated with a solution or solvent containing a basic compound. After that, the solvent is removed by drying, and the basic compound is attached to the surface of the first conductive polymer layer.
  • a solvent is, for example, water.
  • the treatment of adhering the basic compound includes, prior to the formation of the second conductive polymer layer, the anionic first dopant doped into the first conductive polymer in the first conductive polymer layer and the first By suppressing electrostatic repulsion with the anionic second dopant doped into the second conductive polymer in the two conductive polymer layers, the first conductive polymer layer and the second conductive polymer layer This is done to increase the adhesion with. Therefore, the basic compound is precoated along the unevenness of the surface of the first conductive polymer layer.
  • the basic compound may be selected from the compounds already listed (eg, amine compounds).
  • the anode body 1 in which the first conductive polymer layer is precoated with a basic compound is immersed in a second dispersion containing a prepolymerized second conductive polymer, taken out, and decompressed. Dry after treatment or at the same time as vacuum treatment.
  • the second conductive polymer layer is formed on at least a portion of the first conductive polymer layer.
  • the dispersion may include a binder and/or conductive inorganic particles (eg, a conductive carbon material such as carbon black).
  • step (ii) is performed under reduced pressure. It is desirable that the decompression treatment be performed before the step of drying the anode body impregnated with the second dispersion. Thereby, the adhesion between the first conductive polymer layer and the second conductive polymer layer can be improved.
  • the anode body is immersed in the second dispersion liquid, pulled up from the solution or the dispersion liquid, and then the anode body to which the second dispersion liquid has adhered is subjected to reduced pressure treatment.
  • reduced pressure treatment good too.
  • Adhesion of the second conductive polymer layer to the first conductive polymer layer is not sufficient, and a gap is formed between the concave portion on the surface of the first conductive polymer layer and the second conductive polymer layer. Even in this case, the air present in the gaps is released by the reduced pressure, and the second conductive polymer layer having fluidity easily fills the gaps in the recesses of the first conductive polymer layer.
  • the recovered atmospheric pressure pushes the second conductive polymer layer toward the first conductive polymer layer, making it easier to fill the concave portions of the first conductive polymer layer.
  • the adhesion between the first conductive polymer layer and the second conductive polymer layer is improved.
  • the anode body may be impregnated with the second dispersion liquid under reduced pressure.
  • the solution or dispersion liquid can easily enter the recesses of the first conductive polymer layer. , the adhesion between the first conductive polymer layer and the second conductive polymer layer is improved.
  • FIG. 4 is a flow chart showing another example of the process of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to this embodiment.
  • the step of impregnating the anode body with a third dispersion containing the third conductive polymer to form the third conductive polymer layer ( iii) is performed.
  • step (iii) first, the anode body is impregnated with a solution or solvent containing a basic compound. After that, the solvent is removed by drying, and the basic compound is attached to the surface of the second conductive polymer layer.
  • a basic compound is pre-coated along the unevenness of the surface of the second conductive polymer layer.
  • a solvent is, for example, water.
  • the basic compound may be selected from the compounds already listed (eg, amine compounds). The basic compound can enhance the adhesion between the second conductive polymer layer and the third conductive polymer layer.
  • the anode body 1 is immersed in a third dispersion containing a prepolymerized third conductive polymer, taken out, and dried.
  • the third conductive polymer layer is formed on at least part of the second conductive polymer layer.
  • the dispersion may include a binder and/or conductive inorganic particles (eg, a conductive carbon material such as carbon black).
  • step (iii) may be performed under reduced pressure.
  • the decompression treatment is performed before the step of drying the anode body impregnated with the third dispersion.
  • the anode body to which the third dispersion is adhered may be subjected to reduced pressure treatment, or the anode body may be impregnated with the third dispersion under reduced pressure.
  • the basic compound When the basic compound is attached to the surface of the second conductive polymer layer in step (iii), the basic compound may not be attached to the surface of the first conductive polymer layer in step (ii).
  • a dopant may be contained in the second and third conductive polymers.
  • the conductive polymer and dopant may be selected from those exemplified for the solid electrolyte layer 4, respectively.
  • a known binder can be used.
  • the dispersion may contain known additives used in forming the solid electrolyte layer.
  • Step of forming a carbon layer and a conductive resin layer Subsequently, a carbon paste and a metal paste are sequentially applied to the surface of the solid electrolyte layer 4 to form a carbon layer 5a and a metal paste layer 5b.
  • a cathode layer 5 is formed.
  • the configuration of the cathode layer 5 is not limited to this, as long as it has a current collecting function.
  • anode lead terminal 13 and cathode lead terminal 14 are prepared.
  • a second portion 2b of anode wire 2 erected from anode body 1 is joined to anode lead terminal 13 by laser welding, resistance welding, or the like.
  • the conductive adhesive 8 is applied to the cathode layer 5
  • the cathode lead terminal 14 is joined to the cathode portion 7 via the conductive adhesive 8 .
  • capacitor element 10 and exterior body 11 for example, uncured thermosetting resin and filler
  • materials of capacitor element 10 and exterior body 11 for example, uncured thermosetting resin and filler
  • capacitor element 10 is sealed by transfer molding, compression molding, or the like.
  • the anode lead terminal 13 and the cathode lead terminal 14 are partly exposed from the mold.
  • the molding conditions are not particularly limited, and the time and temperature conditions may be appropriately set in consideration of the curing temperature of the thermosetting resin used.
  • anode lead terminal 13 and cathode lead terminal 14 are bent along exterior body 11 to form bent portions.
  • a part of anode lead terminal 13 and cathode lead terminal 14 is arranged on the mounting surface of package 11 .
  • the electrolytic capacitor 20 is manufactured by the above method.
  • An electrolytic capacitor was produced in the following manner.
  • Tantalum metal particles were used as the valve action metal.
  • the tantalum metal particles were formed into a rectangular parallelepiped so that one end of the anode wire made of tantalum metal was embedded in the tantalum metal particles, and then the compact was sintered in vacuum.
  • an anode body (1.7 mm ⁇ 3.3 mm ⁇ 4.4 mm) made of a porous sintered body of tantalum and an anode having one end embedded in the anode body and the remaining portion planted from one surface of the anode body An anode part containing a wire was obtained.
  • the anode body and part of the anode wire planted from the anode body were immersed in a chemical bath filled with an aqueous solution of phosphoric acid, which was an electrolytic aqueous solution, and the other end of the anode wire was connected to the anode body in the chemical bath. .
  • a uniform dielectric of tantalum oxide (Ta 2 O 5 ) is formed on the surface of the anode body (the surface of the porous sintered body including the inner wall surfaces of the pores) and a part of the surface of the anode wire. form the body layer.
  • poly(3,4-ethylenedioxythiophene) as the second conductive polymer, polystyrene sulfonate, and water were mixed to prepare a second dispersion.
  • the anode body was immersed in the second dispersion, the anode body was lifted out of the second dispersion and subjected to reduced pressure treatment. After the decompression treatment, drying treatment was performed at 80° C. for 20 minutes under atmospheric pressure to form a second conductive polymer layer, thereby obtaining anode bodies A1 to A5.
  • the pressure and the decompression time in the decompression process were changed as shown in Table 1. Further, an anode body was manufactured by the same manufacturing method as that for the anode bodies A1 to A5 without performing the decompression treatment, thereby obtaining the anode body B1.
  • the pressure in the depressurization process is indicated by relative pressure (that is, gauge pressure) based on the atmospheric pressure.
  • the reason why the rate of blistering in the anode body A5 was higher than that in the anode body A1 to A4 is that the moisture contained in the dispersion volatilizes due to the pressure reduction for a long time, making it easy to generate air bubbles. It is considered that the surface conditions of the molecular layer and the first conductive polymer layer deteriorated.
  • the present invention can be used for electrolytic capacitors, preferably for electrolytic capacitors using a porous body as an anode body.
  • Electrolytic capacitor 10 Capacitor element 1: Anode body 2: Anode wire 2a: First part 2b: Second part 3: Dielectric layer 4: Solid electrolyte layer 5: Cathode layer 5a: Carbon layer 5b: Metal paste layer 6: Anode part 7: Cathode part 8: Conductive adhesive 11: Exterior body 13: Anode lead terminal 14: Cathode lead terminal 14a: Joining part

Abstract

A method for producing an electrolytic capacitor according to the present invention comprises a step for forming a solid electrolyte layer, which contains a conductive polymer, on the surface of a positive electrode body that is provided with a dielectric layer. The step for forming a solid electrolyte layer comprises: a first step in which a first conductive polymer layer that covers the dielectric layer is formed by having the positive electrode body impregnated with a first solution, which contains a first monomer that serves as the starting material for a first conductive polymer, and polymerizing the first monomer on the surface of the dielectric layer; and a second step in which a second conductive polymer layer that covers the first conductive polymer layer is formed by having the positive electrode body impregnated with a second solution or a second dispersion liquid, each of which contains the second conductive polymer. The second step comprises low-pressure processing of the positive electrode body.

Description

電解コンデンサの製造方法Manufacturing method of electrolytic capacitor
　本発明は、電解コンデンサの製造方法に関する。 The present invention relates to a method for manufacturing an electrolytic capacitor.
　電解コンデンサは、等価直列抵抗（ＥＳＲ）が小さく、周波数特性が優れているため、様々な電子機器に搭載されている。電解コンデンサは、通常、陽極部および陰極部を備えるコンデンサ素子を備える。陽極部は、多孔質の陽極体を含み、陽極体の表面に誘電体層が形成される。誘電体層は、電解質と接触する。電解質として、導電性高分子などの固体電解質を用いた電解コンデンサがある（例えば、特許文献１参照）。 Electrolytic capacitors have a low equivalent series resistance (ESR) and excellent frequency characteristics, so they are installed in various electronic devices. Electrolytic capacitors typically comprise a capacitor element comprising an anode portion and a cathode portion. The anode part includes a porous anode body, and a dielectric layer is formed on the surface of the anode body. The dielectric layer contacts the electrolyte. As an electrolyte, there is an electrolytic capacitor using a solid electrolyte such as a conductive polymer (see, for example, Patent Document 1).
　誘電体層に固体電解質層を形成するに際して、特許文献２には、誘電体層が形成された陽極体の誘電体層上に、（i）シラン化合物の存在下で、第１導電性高分子の前駆体を重合させることにより第１導電性高分子層を形成する工程と、（ii）第１導電性高分子層上に、第２導電性高分子と塩基性化合物とを含み、かつ第１導電性高分子層の少なくとも一部を覆う第２導電性高分子層を形成する工程と、を含む電解コンデンサの製造方法が記載されている。 In forming a solid electrolyte layer on a dielectric layer, Patent Document 2 discloses that (i) a first conductive polymer is added in the presence of a silane compound to the dielectric layer of the anode body on which the dielectric layer is formed. (ii) comprising a second conductive polymer and a basic compound on the first conductive polymer layer, and a first forming a second conductive polymer layer overlying at least a portion of the first conductive polymer layer.
特開２００９－１８２１５７号公報JP 2009-182157 A 再表２０１７－００２３５１号公報Retable 2017-002351
　特許文献２のように固体電解質層を複数の導電性高分子層で形成する場合、導電性高分子層間の密着性が問題になる。導電性高分子層間の密着性が十分でないと、導電性高分子層内に残存する水分等が、後工程で生じる熱により気化膨張し、外側の導電性高分子層が内側の導電性高分子層から剥がれ、導電性高分子層間の隙間を押し広げて空洞が膨らむ場合がある。 When forming a solid electrolyte layer with a plurality of conductive polymer layers as in Patent Document 2, the adhesion between the conductive polymer layers becomes a problem. If the adhesion between the conductive polymer layers is not sufficient, the moisture remaining in the conductive polymer layer will evaporate and expand due to the heat generated in the subsequent process, and the outer conductive polymer layer will become the inner conductive polymer. It may peel off from the layer and expand the gap between the conductive polymer layers to expand the cavity.
　特に、重合で形成した導電性高分子層の上に別の導電性高分子層を形成する場合、重合で用いる酸化剤やドーパントは水と結合し易いため、重合膜中に多くの水分が残留し得る。結果、水分の気化膨張により外側の導電性高分子層が剥がれ、膨らむことによる固体電解質層の形成不良が発生し易くなる。 In particular, when another conductive polymer layer is formed on top of a conductive polymer layer formed by polymerization, the oxidizing agent and dopant used in polymerization easily combine with water, so a large amount of water remains in the polymer film. can. As a result, the outer conductive polymer layer peels off due to vaporization and expansion of water, and the solid electrolyte layer tends to be poorly formed due to swelling.
　上記を鑑み、本開示の一局面は、多孔質の陽極体と、前記陽極体の表面に形成された誘電体層と、前記誘電体層の少なくとも一部を覆う固体電解質層と、前記固体電解質層の少なくとも一部を覆う陰極層と、を備える電解コンデンサの製造方法であって、前記誘電体層が形成された前記陽極体の表面に導電性高分子を含む前記固体電解質層を形成する工程を有し、前記固体電解質層の形成工程は、第１導電性高分子の原料となる第１モノマーを含む第１溶液を、前記陽極体に含侵させ、前記誘電体層の表面で前記第１モノマーを重合させて、前記誘電体層を覆う第１導電性高分子層を形成する第１工程と、第２導電性高分子を含む第２溶液または第２分散液を、前記陽極体に含侵させ、前記第１導電性高分子層を覆う第２導電性高分子層を形成する第２工程と、を有し、前記第２工程は、前記陽極体を減圧処理することを含む、電解コンデンサの製造方法に関する。 In view of the above, one aspect of the present disclosure provides a porous anode body, a dielectric layer formed on the surface of the anode body, a solid electrolyte layer covering at least a portion of the dielectric layer, and the solid electrolyte and a cathode layer covering at least a part of the layer, the step of forming the solid electrolyte layer containing a conductive polymer on the surface of the anode body on which the dielectric layer is formed. The step of forming the solid electrolyte layer includes impregnating the anode body with a first solution containing a first monomer that is a raw material of the first conductive polymer, and forming the first a first step of polymerizing one monomer to form a first conductive polymer layer covering the dielectric layer; a second step of impregnating and forming a second conductive polymer layer covering the first conductive polymer layer, wherein the second step includes subjecting the anode body to a reduced pressure treatment; The present invention relates to a method for manufacturing an electrolytic capacitor.
　複数の導電性高分子層で形成された固体電解質層を備える電解コンデンサの製造において、導電性高分子層間の密着性を高めることができるため、水分等の気化膨張による導電性高分子層の膨れによる不良が低減される。 In the manufacture of an electrolytic capacitor comprising a solid electrolyte layer formed of a plurality of conductive polymer layers, it is possible to improve the adhesion between the conductive polymer layers, so that swelling of the conductive polymer layer due to vaporization expansion of moisture etc. can be prevented. Defects due to are reduced.
　本発明の新規な特徴を添付の請求の範囲に記述するが、本発明は、構成および内容の両方に関し、本発明の他の目的および特徴と併せ、図面を照合した以下の詳細な説明によりさらによく理解されるであろう。 While the novel features of the present invention are set forth in the appended claims, the present invention, both as to construction and content, together with other objects and features of the present invention, will be further developed by the following detailed description in conjunction with the drawings. will be well understood.
本開示の一実施形態に係る製造方法により製造される電解コンデンサのコンデンサ素子の一例を模式的に示す断面図である。1 is a cross-sectional view schematically showing an example of a capacitor element of an electrolytic capacitor manufactured by a manufacturing method according to an embodiment of the present disclosure; FIG. 本開示の一実施形態に係る製造方法により製造される電解コンデンサを模式的に示す断面図である。1 is a cross-sectional view schematically showing an electrolytic capacitor manufactured by a manufacturing method according to an embodiment of the present disclosure; FIG. 本実施形態に係る電解コンデンサの製造方法において、固定電解質層の形成工程の一例を示すフローチャートである。4 is a flow chart showing an example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to the present embodiment. 本実施形態に係る電解コンデンサの製造方法において、固定電解質層の形成工程の他の例を示すフローチャートである。4 is a flow chart showing another example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to the present embodiment.
　以下、本開示の実施形態について例を挙げて説明するが、本開示は以下で説明する例に限定されない。以下の説明では、具体的な数値、材料等を例示する場合があるが、本開示の効果が得られる限り、他の数値、材料等を適用してもよい。この明細書において、「数値Ａ～数値Ｂ」という記載は、数値Ａおよび数値Ｂを含み、「数値Ａ以上で数値Ｂ以下」と読み替えることが可能である。以下の説明において、特定の物性や条件などに関する数値の下限と上限とを例示した場合、下限が上限以上とならない限り、例示した下限のいずれかと例示した上限のいずれかを任意に組み合わせることができる。複数の材料が例示される場合、その中から１種を選択して単独で用いてもよく、２種以上を組み合わせて用いてもよい。  Hereinafter, embodiments of the present disclosure will be described with examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values, materials, etc. may be exemplified, but other numerical values, materials, etc. may be applied as long as the effects of the present disclosure can be obtained. In this specification, the description "numerical value A to numerical value B" includes numerical value A and numerical value B, and can be read as "numerical value A or more and numerical value B or less". In the following description, when lower and upper limits of numerical values relating to specific physical properties, conditions, etc. are exemplified, any of the illustrated lower limits and any of the illustrated upper limits can be arbitrarily combined as long as the lower limit is not greater than or equal to the upper limit. . When a plurality of materials are exemplified, one of them may be selected and used alone, or two or more may be used in combination. 
　また、本開示は、添付の特許請求の範囲に記載の複数の請求項から任意に選択される２つ以上の請求項に記載の事項の組み合わせを包含する。つまり、技術的な矛盾が生じない限り、添付の特許請求の範囲に記載の複数の請求項から任意に選択される２つ以上の請求項に記載の事項を組み合わせることができる。 In addition, the present disclosure encompasses a combination of matters described in two or more claims arbitrarily selected from the multiple claims described in the attached claims. In other words, as long as there is no technical contradiction, the items described in two or more claims arbitrarily selected from the multiple claims described in the attached claims can be combined.
　本開示の一実施形態に係る電解コンデンサの製造方法は、多孔質の陽極体と、陽極体の表面に形成された誘電体層と、誘電体層の少なくとも一部を覆う固体電解質層と、固体電解質層の少なくとも一部を覆う陰極層と、を備える電解コンデンサの製造方法であって、誘電体層が形成された陽極体の表面に導電性高分子を含む固体電解質層を形成する工程を有する。 A method for manufacturing an electrolytic capacitor according to an embodiment of the present disclosure includes a porous anode body, a dielectric layer formed on the surface of the anode body, a solid electrolyte layer covering at least a portion of the dielectric layer, a solid a cathode layer covering at least a portion of the electrolyte layer, the method comprising the step of forming a solid electrolyte layer containing a conductive polymer on the surface of an anode body having a dielectric layer formed thereon. .
　固体電解質層の形成工程は、第１導電性高分子の原料となる第１モノマーを含む第１溶液を、陽極体に含侵させ、誘電体層の表面で第１モノマーを重合させて、誘電体層を覆う第１導電性高分子層を形成する第１工程（i）と、第２導電性高分子を含む第２溶液または第２分散液を、陽極体に含侵させ、第１導電性高分子層を覆う第２導電性高分子層を形成する第２工程（ii）と、を有する。なお、第１モノマーには、オリゴマーが含まれる。 In the step of forming the solid electrolyte layer, the anode body is impregnated with a first solution containing a first monomer as a raw material of the first conductive polymer, and the first monomer is polymerized on the surface of the dielectric layer to form a dielectric layer. a first step (i) of forming a first conductive polymer layer covering the body layer; and a second step (ii) of forming a second conductive polymer layer covering the conductive polymer layer. In addition, an oligomer is contained in a 1st monomer.
　以下において、「第２溶液または第２分散液」の記載については、単に「第２分散液」とし、第２溶液の記載を省略する。つまり、特に明記しない限り、導電性高分子の分散液には、導電性高分子の溶液が含まれるものとする。 In the following, the description of "second solution or second dispersion" will be simply referred to as "second dispersion", and the description of the second solution will be omitted. That is, unless otherwise specified, a dispersion of a conductive polymer includes a solution of a conductive polymer.
　第２工程は、陽極体を減圧処理することを含む。減圧処理は、陽極体に含侵させた第２分散液を乾燥させる前に行えばよく、減圧の開始時期、処理時間および方法については特に限定されない。第２工程では、減圧下で第２分散液中に陽極体を浸漬させて、大気圧解放することで第２分散液を陽極体に含侵させてもよいし、第２分散液中から陽極体を引き上げて、第２分散液が付着した陽極体を減圧および大気圧開放することで、第２分散液を陽極体に含侵させてもよい。第２分散液が付着した陽極体を減圧する場合、減圧処理は、第２分散液中の第２導電性高分子の流動性が十分に確保された状態で開始される。減圧処理は、陽極体に含侵させた第２分散液中の第２導電性高分子の含有率が９０質量％以下もしくは７５質量％以下もしくは５０質量％以下の状態で開始してもよい。 The second step includes depressurizing the anode body. The depressurization treatment may be performed before drying the second dispersion impregnated in the anode body, and there are no particular limitations on the depressurization start time, treatment time and method. In the second step, the anode body may be immersed in the second dispersion under reduced pressure and released to atmospheric pressure to impregnate the second dispersion into the anode body, or the anode body may be impregnated with the second dispersion. The second dispersion may be impregnated into the anode body by pulling up the body and decompressing and releasing the anode body with the second dispersion adhered thereon to the atmospheric pressure. When depressurizing the anode body to which the second dispersion adheres, the depressurization process is started in a state in which the fluidity of the second conductive polymer in the second dispersion is sufficiently ensured. The decompression treatment may be started when the content of the second conductive polymer in the second dispersion impregnated in the anode body is 90% by mass or less, 75% by mass or less, or 50% by mass or less.
　重合により形成された第１導電性高分子層（例えば、化学重合層）の表面は、微視的に見ると、微細な凹凸を有している。減圧処理を行うことで、第２導電性高分子が第１導電性高分子層の表面における凹部の奥深くまで入り込むことができ、第２導電性高分子層の第１導電性高分子層との密着性を向上させることができる。また、膨れの起点となる凹部における空隙の形成も抑制される。これにより、第２導電性高分子層が第１導電性高分子層から剥がれ、膨れが発生することが抑制される。特に、陽極体を第２導分散液中から引き上げた際、重力によって第２分散液が陽極体下部に溜まり易い。減圧処理により、陽極体下部に溜まり易い第２導電性高分子（ポリマー分散体）を含有した分散液の乾燥時の膨れを防止することができ、密着不足による特性ばらつきが抑制される。 The surface of the first conductive polymer layer (eg, chemically polymerized layer) formed by polymerization has fine irregularities when viewed microscopically. By performing the reduced pressure treatment, the second conductive polymer can penetrate deep into the recesses on the surface of the first conductive polymer layer, and the second conductive polymer layer and the first conductive polymer layer can be separated. Adhesion can be improved. In addition, the formation of voids in the concave portion that is the starting point of swelling is also suppressed. This suppresses the second conductive polymer layer from peeling off from the first conductive polymer layer and causing swelling. In particular, when the anode body is lifted out of the second dispersion liquid, gravity tends to cause the second dispersion liquid to accumulate in the lower part of the anode body. The reduced pressure treatment can prevent swelling of the dispersion liquid containing the second conductive polymer (polymer dispersion), which tends to accumulate in the lower portion of the anode body, during drying, and suppress variation in characteristics due to insufficient adhesion.
　減圧処理時の圧力は、少なくとも大気圧よりも低ければよい。減圧処理時の圧力は、例えば、大気圧に対して５０ｋＰａ以上低い圧力であってもよく、大気圧に対して１００ｋＰａ以上低い圧力であってもよい。減圧の処理時間は、第２分散液が付着した陽極体を減圧下に置く場合、１分以上１０分以下であってもよく、２分以上１０分以下であってもよい。 The pressure during the decompression process should be at least lower than the atmospheric pressure. The pressure during the decompression process may be, for example, a pressure lower than the atmospheric pressure by 50 kPa or more, or a pressure lower than the atmospheric pressure by 100 kPa or more. When the anode body to which the second dispersion is adhered is placed under reduced pressure, the treatment time for reducing pressure may be 1 minute or more and 10 minutes or less, or may be 2 minutes or more and 10 minutes or less.
　第２工程では、第２分散液を陽極体に含侵させる前に、塩基性化合物を含む溶液または溶媒を陽極体に含侵させてもよい。塩基性化合物に含まれるカチオンは、導電性高分子に含まれるアニオン性ドーパントの反発を抑制して、第２導電性高分子層と第１導電性高分子層との密着性を高める作用を奏する。予め第１導電性高分子層の表面を塩基化合物の層でプレコートしておき、塩基化合物の層でプレコートされた第１導電性高分子層の表面上に第２導電性高分子層を形成することで、第２導電性高分子層の第１導電性高分子層との密着性が一層向上する。これにより、第２導電性高分子層が第１導電性高分子層から剥がれ、膨れが発生することが一層抑制される。 In the second step, the anode body may be impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the second dispersion. The cation contained in the basic compound suppresses the repulsion of the anionic dopant contained in the conductive polymer, thereby increasing the adhesion between the second conductive polymer layer and the first conductive polymer layer. . The surface of the first conductive polymer layer is precoated with a basic compound layer, and the second conductive polymer layer is formed on the surface of the first conductive polymer layer precoated with the basic compound layer. This further improves the adhesion of the second conductive polymer layer to the first conductive polymer layer. This further suppresses the second conductive polymer layer from peeling off from the first conductive polymer layer and causing swelling.
　同様に、固体電解質層の形成工程は、第２工程の後に、第３導電性高分子を含む第３溶液または第３分散液（以降において、特に断らない限り、「第３溶液または第３分散液」を単に「第３分散液」と記載し、第３溶液の記載を省略する。）を陽極体に含侵させ、第３導電性高分子層を形成する第３工程をさらに有してもよい。その場合、第３工程において、第３分散液を陽極体に含侵させる前に、塩基性化合物を含む溶液または溶媒を陽極体に含侵させてもよい。予め第２導電性高分子層の表面を塩基化合物の層でプレコートしておき、塩基化合物の層でプレコートされた第２導電性高分子層の表面上に第３導電性高分子層を形成することで、第３導電性高分子層の第２導電性高分子層との密着性が向上し、これにより、第３導電性高分子層が第２導電性高分子層から剥がれ、膨れが発生することが抑制される。 Similarly, in the step of forming the solid electrolyte layer, after the second step, a third solution or third dispersion containing a third conductive polymer (hereinafter, unless otherwise specified, "third solution or third dispersion liquid" is simply referred to as "third dispersion liquid", and the description of the third solution is omitted.) is impregnated into the anode body to form a third conductive polymer layer. good too. In this case, in the third step, the anode body may be impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the third dispersion. The surface of the second conductive polymer layer is pre-coated with a basic compound layer, and the third conductive polymer layer is formed on the surface of the second conductive polymer layer pre-coated with the basic compound layer. As a result, the adhesion of the third conductive polymer layer to the second conductive polymer layer is improved, and as a result, the third conductive polymer layer is peeled off from the second conductive polymer layer, causing swelling. is suppressed.
　しかしながら、第１導電性高分子層の上に第２導電性高分子層を形成する場合、塩基性化合物を含む層で第１導電性高分子層の表面をプレコートすると、塩基性化合物の一部が第２分散液中に溶出し、第２分散液の粘性が大きくなる。第１導電性高分子層の表面における凹部は、その上に形成される他の導電性高分子層に比べ特に微細であり、第２導電性高分子層と第１導電性高分子層との密着性を向上させる点では、第２導電性高分子が第１導電性高分子層の表面における凹部の奥深くまで入り込み易くするために、第１導電性高分子層の表面を塩基性化合物でプレコートせず、第１導電性高分子層の上に直接第２導電性高分子層を形成してもよい。特に固体電解質層を３層以上の導電性高分子層で形成する場合には、第１導電性高分子層の表面を塩基性化合物でプレコートせず、直接第２導電性高分子層を形成することが好ましい。 However, when forming the second conductive polymer layer on the first conductive polymer layer, if the surface of the first conductive polymer layer is pre-coated with a layer containing a basic compound, part of the basic compound dissolves into the second dispersion, increasing the viscosity of the second dispersion. The recesses on the surface of the first conductive polymer layer are particularly fine compared to other conductive polymer layers formed thereon, and the recesses between the second conductive polymer layer and the first conductive polymer layer are particularly fine. In terms of improving adhesion, the surface of the first conductive polymer layer is pre-coated with a basic compound so that the second conductive polymer can easily penetrate deep into the recesses on the surface of the first conductive polymer layer. Alternatively, the second conductive polymer layer may be formed directly on the first conductive polymer layer. In particular, when the solid electrolyte layer is formed of three or more conductive polymer layers, the second conductive polymer layer is directly formed without precoating the surface of the first conductive polymer layer with a basic compound. is preferred.
　つまり、第３工程において塩基化合物の層で第２導電性高分子層の表面を予めプレコートする場合、第２工程において、塩基性化合物を含む溶液または溶媒を陽極体に含侵させず、第１導電性高分子層の表面を塩基性化合物でプレコートしなくてもよい。 That is, when the surface of the second conductive polymer layer is previously precoated with a layer of a basic compound in the third step, the anode body is not impregnated with a solution or solvent containing a basic compound in the second step. The surface of the conductive polymer layer may not be precoated with a basic compound.
　固体電解質層は、２層の導電性高分子層により形成されていてもよいし、３層以上の導電性高分子層により形成されていてもよい。 The solid electrolyte layer may be formed of two conductive polymer layers, or may be formed of three or more conductive polymer layers.
　塩基性化合物としては、例えば、Ｎ，Ｎ－ジメチルオクチルアミン、１，８－ジアミノオクタンなどのアミン化合物またはアミジン化合物が好ましく用いられ得る。 As the basic compound, for example, amine compounds or amidine compounds such as N,N-dimethyloctylamine and 1,8-diaminooctane can be preferably used.
　第１導電性高分子層に含まれる第１導電性高分子、第２導電性高分子層に含まれる第２導電性高分子、および、第３導電性高分子層に含まれる第３導電性高分子は、それぞれ、同じであってもよいし、異なるモノマーユニットを含んでいてもよい。第３導電性高分子は、第２導電性高分子を構成するモノマーユニットと同じモノマーユニットを含んでいることが好ましい。同じモノマー骨格を有する導電性高分子層を厚く形成することができる。 A first conductive polymer contained in the first conductive polymer layer, a second conductive polymer contained in the second conductive polymer layer, and a third conductive polymer contained in the third conductive polymer layer The macromolecules may each contain the same or different monomeric units. The third conductive polymer preferably contains the same monomer units as those constituting the second conductive polymer. A thick conductive polymer layer having the same monomer skeleton can be formed.
　以下に、本実施形態に係る電解コンデンサの製造方法について、適宜図面を参照しながら説明する。しかしながら、本発明はこれに限定されるものではない。図１は、本実施形態に係る製造方法により製造される電解コンデンサのコンデンサ素子の一例を模式的に示す断面図である。図２は、本実施形態に係る製造方法により製造される電解コンデンサの断面模式図である。 A method for manufacturing an electrolytic capacitor according to this embodiment will be described below with reference to the drawings as appropriate. However, the invention is not limited to this. FIG. 1 is a cross-sectional view schematically showing an example of a capacitor element of an electrolytic capacitor manufactured by the manufacturing method according to this embodiment. FIG. 2 is a schematic cross-sectional view of an electrolytic capacitor manufactured by the manufacturing method according to this embodiment.
　電解コンデンサ２０は、陽極部６および陰極部７を有するコンデンサ素子１０と、コンデンサ素子１０を封止する外装体１１と、陽極部６と電気的に接続し、かつ、外装体１１から一部が露出する陽極リード端子１３と、陰極部７と電気的に接続し、かつ、外装体１１から一部が露出する陰極リード端子１４と、を備えている。陽極部６は、陽極体１と陽極ワイヤ２とを有する。陽極体の表面に誘電体層３が形成されている。陰極部７は、誘電体層３の少なくとも一部を覆う固体電解質層４と、固体電解質層４の表面の少なくとも一部を覆う陰極層５とを有する。 Electrolytic capacitor 20 is electrically connected to capacitor element 10 having anode portion 6 and cathode portion 7, exterior body 11 that seals capacitor element 10, and anode section 6, and a portion of exterior body 11 extends from An exposed anode lead terminal 13 and a cathode lead terminal 14 electrically connected to the cathode section 7 and partly exposed from the exterior body 11 are provided. Anode section 6 has anode body 1 and anode wire 2 . A dielectric layer 3 is formed on the surface of the anode body. Cathode portion 7 has solid electrolyte layer 4 covering at least part of dielectric layer 3 and cathode layer 5 covering at least part of the surface of solid electrolyte layer 4 .
＜コンデンサ素子＞
　以下、コンデンサ素子１０について、電解質として固体電解質層を備える場合を例に挙げて、詳細に説明する。 <Capacitor element>
Hereinafter, capacitor element 10 will be described in detail, taking as an example a case in which a solid electrolyte layer is provided as an electrolyte.
　陽極部６は、陽極体１と、陽極体１の一面から延出して陽極リード端子１３と電気的に接続する陽極ワイヤ２と、を有する。
　陽極体１は、例えば、金属粒子を焼結して得られる直方体の多孔質焼結体である。上記金属粒子として、チタン（Ｔｉ）、タンタル（Ｔａ）、ニオブ（Ｎｂ）などの弁作用金属の粒子が用いられる。陽極体１には、１種または２種以上の金属粒子が用いられる。金属粒子は、２種以上の金属からなる合金であってもよい。例えば、弁作用金属と、ケイ素、バナジウム、ホウ素等とを含む合金を用いることができる。また、弁作用金属と窒素等の典型元素とを含む化合物を用いてもよい。弁作用金属の合金は、弁作用金属を主成分とし、例えば、弁作用金属を５０原子％以上含む。 Anode section 6 has anode body 1 and anode wire 2 extending from one surface of anode body 1 and electrically connected to anode lead terminal 13 .
Anode body 1 is, for example, a cuboid porous sintered body obtained by sintering metal particles. As the metal particles, particles of valve action metals such as titanium (Ti), tantalum (Ta) and niobium (Nb) are used. One or two or more kinds of metal particles are used in anode body 1 . The metal particles may be an alloy of two or more metals. For example, an alloy containing a valve action metal and silicon, vanadium, boron, or the like can be used. A compound containing a valve action metal and a typical element such as nitrogen may also be used. The alloy of the valve action metal is mainly composed of the valve action metal, and contains, for example, 50 atomic % or more of the valve action metal.
　陽極ワイヤ２は、導電性材料から構成されている。陽極ワイヤ２の材料は特に限定されず、例えば、上記弁作用金属の他、銅、アルミニウム、アルミニウム合金等が挙げられる。陽極体１および陽極ワイヤ２を構成する材料は、同種であってもよいし、異種であってもよい。陽極ワイヤ２は、陽極体１の一面から陽極体１の内部へ埋設された第一部分２ａと、陽極体１の上記一面から延出した第二部分２ｂと、を有する。陽極ワイヤ２の断面形状は特に限定されず、円形、トラック形（互いに平行な直線とこれら直線の端部同士を繋ぐ２本の曲線とからなる形状）、楕円形、矩形、多角形等が挙げられる。 The anode wire 2 is made of a conductive material. The material of the anode wire 2 is not particularly limited, and examples thereof include the above-described valve action metals, copper, aluminum, aluminum alloys, and the like. The materials constituting anode body 1 and anode wire 2 may be of the same type or of different types. Anode wire 2 has a first portion 2 a embedded inside anode body 1 from one surface of anode body 1 and a second portion 2 b extending from the one surface of anode body 1 . The cross-sectional shape of the anode wire 2 is not particularly limited, and may be circular, track-shaped (a shape consisting of mutually parallel straight lines and two curved lines connecting the ends of these straight lines), elliptical, rectangular, polygonal, and the like. be done.
　陽極部６は、例えば、第一部分２ａを上記第１金属の粒子の粉体中に埋め込んだ状態で直方体状に加圧成形し、焼結することにより作製される。これにより、陽極体１の一面から、陽極ワイヤ２の第二部分２ｂが植立するように引き出される。第二部分２ｂは、溶接等により、陽極リード端子１３と接合されて、陽極ワイヤ２と陽極リード端子１３とが電気的に接続する。溶接の方法は特に限定されず、抵抗溶接、レーザー溶接等が挙げられる。 The anode portion 6 is produced, for example, by embedding the first portion 2a in the powder of the first metal particles, molding the first portion 2a into a rectangular parallelepiped shape, and sintering the first portion. As a result, the second portion 2b of the anode wire 2 is pulled out from one surface of the anode body 1 so as to be erected. The second portion 2b is joined to the anode lead terminal 13 by welding or the like, so that the anode wire 2 and the anode lead terminal 13 are electrically connected. The welding method is not particularly limited, and includes resistance welding, laser welding, and the like.
　陽極体１の表面には、誘電体層３が形成されている。誘電体層３は、例えば、金属酸化物から構成されている。陽極体１の表面に金属酸化物を含む層を形成する方法として、例えば、化成液中に陽極体１を浸漬して陽極体１の表面を陽極酸化する方法や、陽極体１を、酸素を含む雰囲気下で加熱する方法が挙げられる。誘電体層３は、上記金属酸化物を含む層に限定されず、絶縁性を有していればよい。 A dielectric layer 3 is formed on the surface of the anode body 1 . The dielectric layer 3 is made of metal oxide, for example. As a method for forming a layer containing a metal oxide on the surface of anode body 1, for example, anode body 1 is immersed in a chemical solution to anodize the surface of anode body 1, or anode body 1 is immersed in oxygen. A method of heating in an atmosphere containing The dielectric layer 3 is not limited to the layer containing the above-mentioned metal oxide, and may have insulating properties.
（陰極部）
　陰極部７は、固体電解質層４と、固体電解質層４を覆う陰極層５とを有している。固体電解質層４は、誘電体層３の少なくとも一部を覆うように形成されている。 (cathode)
The cathode section 7 has a solid electrolyte layer 4 and a cathode layer 5 covering the solid electrolyte layer 4 . Solid electrolyte layer 4 is formed to cover at least a portion of dielectric layer 3 .
　固体電解質層４には、例えば、マンガン化合物や導電性高分子が用いられる。導電性高分子としては、ポリピロール、ポリチオフェン、ポリフラン、ポリアニリン、ポリアセチレン、などが挙げられる。これらは、単独で用いてもよく、複数種を組み合わせて用いてもよい。また、導電性高分子は、２種以上のモノマーの共重合体でもよい。導電性に優れる点で、ポリチオフェン、ポリアニリン、ポリピロールであってもよい。特に、撥水性に優れる点で、ポリピロールであってもよい。 For example, a manganese compound or a conductive polymer is used for the solid electrolyte layer 4 . Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, and the like. These may be used alone, or may be used in combination. Also, the conductive polymer may be a copolymer of two or more monomers. Polythiophene, polyaniline, and polypyrrole may be used from the viewpoint of excellent conductivity. In particular, polypyrrole may be used because of its excellent water repellency.
　上記導電性高分子を含む固体電解質層４は、２層以上の固体電解質層から構成され、例えば、誘電体層３を覆う第１導電性高分子層と、第１導電性高分子層を覆う第２導電性高分子層を含む。固体電解質層４が２層以上から構成されている場合、各層に用いられる導電性高分子の組成や形成方法（重合方法）等は異なっていてもよい。例えば、第１導電性高分子層を、原料モノマーを誘電体層３上で重合することにより、形成してもよい。あるいは、第２導電性高分子層を、上記導電性高分子を含んだ液を誘電体層３に塗布することにより、形成してもよい。 The solid electrolyte layer 4 containing the conductive polymer is composed of two or more solid electrolyte layers, for example, a first conductive polymer layer covering the dielectric layer 3 and a first conductive polymer layer covering the first conductive polymer layer. A second conductive polymer layer is included. When the solid electrolyte layer 4 is composed of two or more layers, the composition and formation method (polymerization method) of the conductive polymer used for each layer may be different. For example, the first conductive polymer layer may be formed by polymerizing raw material monomers on the dielectric layer 3 . Alternatively, the second conductive polymer layer may be formed by applying a liquid containing the conductive polymer to the dielectric layer 3 .
　なお、本明細書では、ポリピロール、ポリチオフェン、ポリフラン、ポリアニリンなどは、それぞれ、ポリピロール、ポリチオフェン、ポリフラン、ポリアニリンなどを基本骨格とする高分子を意味する。したがって、ポリピロール、ポリチオフェン、ポリフラン、ポリアニリンなどには、それぞれの誘導体も含まれ得る。例えば、ポリチオフェンには、ポリ（３，４－エチレンジオキシチオフェン）などが含まれる。 In this specification, polypyrrole, polythiophene, polyfuran, polyaniline, etc. mean polymers having polypyrrole, polythiophene, polyfuran, polyaniline, etc. as a basic skeleton, respectively. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline, etc. may also include their respective derivatives. For example, polythiophenes include poly(3,4-ethylenedioxythiophene) and the like.
　導電性高分子を形成するための重合液、導電性高分子の溶液または分散液には、導電性高分子の導電性を向上させるために、様々なドーパントを添加してもよい。ドーパントは、特に限定されないが、例えば、ナフタレンスルホン酸、ｐ－トルエンスルホン酸、ポリスチレンスルホン酸などが挙げられる。 Various dopants may be added to the polymerization liquid, solution or dispersion of the conductive polymer for forming the conductive polymer, in order to improve the conductivity of the conductive polymer. Although the dopant is not particularly limited, examples include naphthalenesulfonic acid, p-toluenesulfonic acid, polystyrenesulfonic acid and the like.
　導電性高分子が、粒子の状態で分散媒に分散している場合、その粒子の平均粒径Ｄ５０は、例えば０．０１μｍ以上、０．５μｍ以下である。粒子の平均粒径Ｄ５０がこの範囲であれば、陽極体１の内部にまで粒子が侵入し易くなる。 When the conductive polymer is dispersed in the dispersion medium in the form of particles, the average particle diameter D50 of the particles is, for example, 0.01 μm or more and 0.5 μm or less. If the average particle diameter D50 of the particles is within this range, the particles can easily penetrate into the interior of anode body 1 .
　陰極層５は、例えば、固体電解質層４を覆うように形成されたカーボン層５ａと、カーボン層５ａの表面に形成された金属ペースト層５ｂと、を有している。カーボン層５ａは、黒鉛等の導電性炭素材料と樹脂を含む。金属ペースト層５ｂは、例えば、金属粒子（例えば、銀）と樹脂とを含む。なお、陰極層５の構成は、この構成に限定されない。陰極層５の構成は、集電機能を有する構成であればよい。 The cathode layer 5 has, for example, a carbon layer 5a formed to cover the solid electrolyte layer 4 and a metal paste layer 5b formed on the surface of the carbon layer 5a. The carbon layer 5a contains a conductive carbon material such as graphite and a resin. The metal paste layer 5b contains, for example, metal particles (for example, silver) and resin. In addition, the structure of the cathode layer 5 is not limited to this structure. The configuration of the cathode layer 5 may be any configuration as long as it has a current collecting function.
（塩基性化合物）
　固体電解質層４が複数層の導電性高分子層から構成される場合、導電性高分子層間の密着性を向上させるために、導電性高分子層間に塩基性化合物を介在させてもよい。 (basic compound)
When the solid electrolyte layer 4 is composed of a plurality of conductive polymer layers, a basic compound may be interposed between the conductive polymer layers in order to improve adhesion between the conductive polymer layers.
　塩基性化合物としては、アンモニアなどの無機塩基の他、アミン化合物などの有機塩基が挙げられる。導電性の低下を抑制する効果が高い観点から、塩基性化合物のうち、アミン化合物が好ましい。アミン化合物は、１級アミン、２級アミン、３級アミンのいずれであってもよい。アミン化合物としては、脂肪族アミン、環状アミンなどが挙げられる。塩基性化合物は、一種を単独で用いてもよく、二種以上を組み合わせて用いてもよい。 Basic compounds include inorganic bases such as ammonia, as well as organic bases such as amine compounds. Among the basic compounds, amine compounds are preferable from the viewpoint of being highly effective in suppressing a decrease in conductivity. Any of a primary amine, a secondary amine, and a tertiary amine may be sufficient as an amine compound. Amine compounds include aliphatic amines and cyclic amines. A basic compound may be used individually by 1 type, and may be used in combination of 2 or more types.
　脂肪族アミンとしては、エチルアミン、ジエチルアミン、トリエチルアミン、Ｎ、Ｎ－ジメチルオクチルアミン、Ｎ，Ｎ－ジエチルオクチルアミンなどのアルキルアミン；エタノールアミン、２－エチルアミノエタノール、ジエタノールアミンなどのアルカノールアミン； アリルアミン；Ｎ－エチルエチレンジアミン、１，８－ジアミノオクタンなどのアルキレンジアミンなどが挙げられる。脂環族アミンとしては、例えば、アミノシクロヘキサン、ジアミノシクロヘキサン、イソホロンジアミンなどが挙げられる。芳香族アミンとしては、例えば、アニリン、トルイジンなどが挙げられる。 Aliphatic amines include alkylamines such as ethylamine, diethylamine, triethylamine, N,N-dimethyloctylamine and N,N-diethyloctylamine; alkanolamines such as ethanolamine, 2-ethylaminoethanol and diethanolamine; -ethylethylenediamine, alkylenediamine such as 1,8-diaminooctane, and the like. Alicyclic amines include, for example, aminocyclohexane, diaminocyclohexane, and isophoronediamine. Examples of aromatic amines include aniline and toluidine.
　環状アミンとしては、ピロール、イミダゾリン、イミダゾール、ピラゾール、ピリジン、ピラジン、ピリミジン、トリアジンなどの５～８員（好ましくは５員または６員）の窒素含有環骨格を有する環状アミンが好ましい。環状アミンは、窒素含有環骨格を１つ有してもよく、２つ以上（例えば、２または３個）有してもよい。環状アミンが２つ以上の窒素含有環骨格を有する場合、窒素含有環骨格は同じであってもよく、異なっていてもよい。 Cyclic amines are preferably cyclic amines having a 5- to 8-membered (preferably 5- or 6-membered) nitrogen-containing ring skeleton, such as pyrrole, imidazoline, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, and triazine. Cyclic amines may have one nitrogen-containing ring skeleton, or two or more (eg, two or three). When the cyclic amine has more than one nitrogen-containing ring skeleton, the nitrogen-containing ring skeletons may be the same or different.
　アミン化合物は、必要に応じて、置換基を有していてもよい。導電性高分子層がアミン化合物を含むことは、例えば、ガスクロマグトラフィー（ＧＣ）により分析することができる。 The amine compound may have a substituent as necessary. Whether the conductive polymer layer contains an amine compound can be analyzed, for example, by gas chromatography (GC).
＜陽極リード端子＞
　陽極リード端子１３は、陽極ワイヤ２の第二部分２ｂを介して、陽極体１と電気的に接続している。陽極リード端子１３の材質は、電気化学的および化学的に安定であり、導電性を有するものであれば特に限定されない。陽極リード端子１３は、例えば銅等の金属であってもよいし、非金属であってもよい。その形状は平板状であれば、特に限定されない。陽極リード端子１３の厚み（陽極リード端子１３の主面間の距離）は、低背化の観点から、２５μｍ以上、２００μｍ以下であってよく、２５μｍ以上、１００μｍ以下であってよい。 <Anode lead terminal>
Anode lead terminal 13 is electrically connected to anode body 1 through second portion 2 b of anode wire 2 . The material of anode lead terminal 13 is not particularly limited as long as it is electrochemically and chemically stable and has conductivity. The anode lead terminal 13 may be made of metal such as copper, or may be made of non-metal. The shape is not particularly limited as long as it is flat. The thickness of anode lead terminal 13 (the distance between the main surfaces of anode lead terminal 13) may be 25 μm or more and 200 μm or less, and may be 25 μm or more and 100 μm or less, from the viewpoint of height reduction.
　陽極リード端子１３の一端は、導電性接着材やはんだにより、陽極ワイヤ２に接合されてもよいし、抵抗溶接やレーザ溶接により、陽極ワイヤ２に接合されてもよい。陽極リード端子１３の他方の端部は、外装体１１の外部へと導出されて、外装体１１から露出している。導電性接着材は、例えば後述する熱硬化性樹脂と炭素粒子や金属粒子との混合物である。 One end of the anode lead terminal 13 may be joined to the anode wire 2 with a conductive adhesive or solder, or may be joined to the anode wire 2 by resistance welding or laser welding. The other end of anode lead terminal 13 is led out of package 11 and exposed from package 11 . The conductive adhesive is, for example, a mixture of a thermosetting resin, which will be described later, and carbon particles or metal particles.
＜陰極リード端子＞
　陰極リード端子１４は、接合部１４ａにおいて陰極部７と電気的に接続している。接合部１４ａは、陰極層５と陰極層５に接合された陰極リード端子１４とを、陰極層５の法線方向からみたとき、陰極リード端子１４の陰極層５に重複する部分である。 <Cathode lead terminal>
The cathode lead terminal 14 is electrically connected to the cathode portion 7 at the joint portion 14a. When the cathode layer 5 and the cathode lead terminal 14 joined to the cathode layer 5 are viewed from the normal direction of the cathode layer 5 , the junction portion 14 a is a portion where the cathode lead terminal 14 overlaps the cathode layer 5 .
　陰極リード端子１４は、例えば、導電性接着材８を介して、陰極層５に接合される。陰極リード端子１４の一方の端部は、例えば接合部１４ａの一部を構成しており、外装体１１の内部に配置される。陰極リード端子１４の他方の端部は、外部へと導出されている。そのため、陰極リード端子１４の他方の端部を含む一部は、外装体１１から露出している。 The cathode lead terminal 14 is joined to the cathode layer 5 via a conductive adhesive 8, for example. One end of the cathode lead terminal 14 constitutes, for example, a part of the joint portion 14 a and is arranged inside the exterior body 11 . The other end of the cathode lead terminal 14 is led out to the outside. Therefore, a portion including the other end of cathode lead terminal 14 is exposed from exterior body 11 .
　陰極リード端子１４の材質も、電気化学的および化学的に安定であり、導電性を有するものであれば、特に限定されない。陰極リード端子１４は、例えば銅等の金属であってもよいし、非金属であってもよい。その形状も特に限定されず、例えば、長尺かつ平板状である。陰極リード端子１４の厚みは、低背化の観点から、２５μｍ以上２００μｍ以下であってもよく、２５μｍ以上１００μｍ以下であってもよい。 The material of the cathode lead terminal 14 is also not particularly limited as long as it is electrochemically and chemically stable and has conductivity. The cathode lead terminal 14 may be made of metal such as copper, or may be made of non-metal. The shape is not particularly limited, either, and for example, it is long and flat. The thickness of the cathode lead terminal 14 may be 25 μm or more and 200 μm or less, or may be 25 μm or more and 100 μm or less, from the viewpoint of height reduction.
＜外装体＞
　外装体１１は、陽極リード端子１３と陰極リード端子１４とを電気的に絶縁するために設けられており、絶縁性の材料（外装体材料）から構成されている。外装体材料は、例えば、熱硬化性樹脂を含む。熱硬化性樹脂としては、例えば、エポキシ樹脂、フェノール樹脂、シリコーン樹脂、メラミン樹脂、尿素樹脂、アルキド樹脂、ポリウレタン、ポリイミド、不飽和ポリエステル等が挙げられる。 <Exterior body>
The exterior body 11 is provided to electrically insulate the anode lead terminal 13 and the cathode lead terminal 14, and is made of an insulating material (sheath material). The exterior body material includes, for example, thermosetting resin. Examples of thermosetting resins include epoxy resins, phenol resins, silicone resins, melamine resins, urea resins, alkyd resins, polyurethanes, polyimides, unsaturated polyesters, and the like.
≪電解コンデンサの製造方法≫
　以下に、本実施形態に係る電解コンデンサの製造方法の一例を説明する。 ≪Manufacturing method of electrolytic capacitor≫
An example of the method for manufacturing the electrolytic capacitor according to this embodiment will be described below.
（１）コンデンサ素子の準備工程
　先ず、コンデンサ素子を準備する。コンデンサ素子を準備する工程は、例えば、陽極体を準備する工程と、陽極体の少なくとも一部を誘電体層で覆う工程と、誘電体層の少なくとも一部を固体電解質層で覆う工程と、固体電解質層の少なくとも一部をカーボン層で覆う工程と、を含む。コンデンサ素子を準備する工程は、さらに、カーボン層の少なくとも一部を導電性樹脂層で覆う工程を含んでもよい。 (1) Capacitor Element Preparing Step First, a capacitor element is prepared. The steps of preparing the capacitor element include, for example, preparing an anode body, covering at least part of the anode body with a dielectric layer, covering at least part of the dielectric layer with a solid electrolyte layer, and solid and covering at least a portion of the electrolyte layer with a carbon layer. The step of preparing the capacitor element may further include the step of covering at least part of the carbon layer with a conductive resin layer.
（１ａ）陽極体の準備工程
　陽極体１としては、多孔質焼結体を用いることができる。弁作用金属粒子と陽極ワイヤ２とを、第一部分２ａが弁作用金属粒子に埋め込まれるように型に入れ、加圧成形した後、焼結することにより、弁作用金属の多孔体である陽極体１を含む陽極部６を得る。陽極ワイヤの第一部分２ａは、多孔質焼結体の一面からその内部に埋設されている。加圧成形の際の圧力は特に限定されない。焼結は、減圧下で行なうことが好ましい。弁作用金属粒子には、必要に応じて、ポリアクリルカーボネート等のバインダを混合してもよい。 (1a) Anode Body Preparing Step As the anode body 1, a porous sintered body can be used. The valve-acting metal particles and the anode wire 2 are placed in a mold so that the first portion 2a is embedded in the valve-acting metal particles, pressure-molded, and then sintered to form an anode body, which is a porous body of the valve-acting metal. An anode portion 6 containing 1 is obtained. A first portion 2a of the anode wire is embedded inside the porous sintered body from one side thereof. The pressure during pressure molding is not particularly limited. Sintering is preferably performed under reduced pressure. If necessary, the valve metal particles may be mixed with a binder such as polyacrylic carbonate.
　弁作用金属粒子は、通常、直方体の内部空間を有する型を用いて加圧成形され、焼結される。この場合、焼結後の陽極体１の形状も直方体であり、複数の主面を有している。 The valve action metal particles are usually pressure-molded and sintered using a mold with a rectangular parallelepiped internal space. In this case, the shape of anode body 1 after sintering is also a rectangular parallelepiped and has a plurality of main surfaces.
（１ｂ）誘電体層の形成工程
　次に、陽極体１を化成処理し、陽極体１の少なくとも一部を誘電体層３で覆う。具体的には、電解水溶液（例えば、リン酸水溶液）が満たされた化成槽に、陽極体１を浸漬し、陽極ワイヤ２の第二部分２ｂを化成槽の陽極体に接続して、陽極酸化を行うことにより、多孔質部分の表面に弁作用金属の酸化被膜からなる誘電体層３を形成することができる。電解水溶液としては、リン酸水溶液に限らず、硝酸、酢酸、硫酸などを用いることができる。 (1b) Step of Forming Dielectric Layer Next, anode body 1 is subjected to chemical conversion treatment, and at least a portion of anode body 1 is covered with dielectric layer 3 . Specifically, the anode body 1 is immersed in an anodizing tank filled with an electrolytic aqueous solution (for example, a phosphoric acid aqueous solution), the second portion 2b of the anode wire 2 is connected to the anode body in the anodizing tank, and anodization is performed. can form the dielectric layer 3 made of the oxide film of the valve action metal on the surface of the porous portion. The electrolytic aqueous solution is not limited to the phosphoric acid aqueous solution, and nitric acid, acetic acid, sulfuric acid, or the like can be used.
（１ｃ）固体電解質層の形成工程
　続いて、誘電体層３の少なくとも一部を固体電解質層４で覆う。これにより、陽極体１、誘電体層３、および固体電解質層４を含むコンデンサ素子１０を得る。複数の導電性高分子層を含む固体電解質層４を形成してもよい。 (1c) Step of Forming Solid Electrolyte Layer Subsequently, at least part of the dielectric layer 3 is covered with the solid electrolyte layer 4 . Capacitor element 10 including anode body 1 , dielectric layer 3 , and solid electrolyte layer 4 is thus obtained. A solid electrolyte layer 4 including a plurality of conductive polymer layers may be formed.
　固体電解質層の形成工程は、第１導電性高分子の原料となる第１モノマーを含む溶液を陽極体に含侵させ、誘電体層の表面で第１モノマーを重合させて、誘電体層を覆う第１導電性高分子層を形成する工程（i）と、第２導電性高分子を含む第２分散液を陽極体に含侵させ、第１導電性高分子層を覆う第２導電性高分子層を形成する工程（ii）と、を有する。図３は、本実施形態に係る電解コンデンサの製造方法において、固定電解質層の形成工程の一例を示すフローチャートである。 In the step of forming the solid electrolyte layer, the anode body is impregnated with a solution containing a first monomer as a raw material of the first conductive polymer, and the first monomer is polymerized on the surface of the dielectric layer to form the dielectric layer. step (i) of forming a covering first conductive polymer layer; and a step (ii) of forming a polymer layer. FIG. 3 is a flow chart showing an example of a step of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to this embodiment.
　工程（i）では、モノマーやオリゴマーを含浸させ、その後、化学重合や電解重合によりモノマーやオリゴマーを重合させる方法により、誘電体層３が形成された陽極体１に第１導電性高分子層を形成する。第１導電性高分子には、ドーパントが含まれていてもよい。導電性高分子およびドーパントとしては、それぞれ、固体電解質層４について例示したものから選択すればよい。 In step (i), a first conductive polymer layer is formed on anode body 1 having dielectric layer 3 formed thereon by impregnating with a monomer or oligomer and then polymerizing the monomer or oligomer by chemical polymerization or electrolytic polymerization. Form. The first conductive polymer may contain a dopant. The conductive polymer and dopant may be selected from those exemplified for the solid electrolyte layer 4, respectively.
　第１導電性高分子層を形成する工程（i）では、誘電体層３の上方で第１導電性高分子の原料モノマーを酸化重合（いわゆる「その場重合」）させて、誘電体層３上に第１導電性高分子層を形成する。このため、第１導電性高分子層の表面には、重合反応の不均一や層成長の不均一などに伴う細かい凹凸が生じ得る。 In the step (i) of forming the first conductive polymer layer, the raw material monomer of the first conductive polymer is oxidatively polymerized (so-called “in situ polymerization”) above the dielectric layer 3 to form the dielectric layer 3. A first conductive polymer layer is formed thereover. For this reason, the surface of the first conductive polymer layer may have fine unevenness due to non-uniform polymerization reaction, non-uniform layer growth, and the like.
　工程（ii）では、先ず、塩基性化合物を含む溶液または溶媒を陽極体に含侵させる。その後、乾燥により溶媒を除去し、第１導電性高分子層の表面に塩基性化合物を付着させる。溶媒は、例えば、水である。塩基性化合物を付着させる処理は、第２導電性高分子層の形成に先立って、第１導電性高分子層内の第１導電性高分子にドープされたアニオン性の第１ドーパントと、第２導電性高分子層内の第２導電性高分子にドープされるアニオン性の第２ドーパントとの静電的反発を抑制して、第１導電性高分子層と第２導電性高分子層との密着性を高めるために行われる。よって、塩基性化合物は、第１導電性高分子層の表面の凹凸に沿ってプレコートされる。塩基性化合物としては、既に挙げた化合物（例えば、アミン化合物）から選択すればよい。 In step (ii), first, the anode body is impregnated with a solution or solvent containing a basic compound. After that, the solvent is removed by drying, and the basic compound is attached to the surface of the first conductive polymer layer. A solvent is, for example, water. The treatment of adhering the basic compound includes, prior to the formation of the second conductive polymer layer, the anionic first dopant doped into the first conductive polymer in the first conductive polymer layer and the first By suppressing electrostatic repulsion with the anionic second dopant doped into the second conductive polymer in the two conductive polymer layers, the first conductive polymer layer and the second conductive polymer layer This is done to increase the adhesion with. Therefore, the basic compound is precoated along the unevenness of the surface of the first conductive polymer layer. The basic compound may be selected from the compounds already listed (eg, amine compounds).
　続いて、第１導電性高分子層が塩基性化合物でプレコートされた陽極体１を、予め重合された第２導電性高分子を含有している第２分散液に浸漬し、取り出して、減圧処理後または減圧処理と同時に乾燥させる。これにより、第２導電性高分子層が第１導電性高分子層の少なくとも一部に形成される。分散液には、バインダ、および／または導電性の無機粒子（例えば、カーボンブラックなどの導電性炭素材料）が含まれていてもよい。 Subsequently, the anode body 1 in which the first conductive polymer layer is precoated with a basic compound is immersed in a second dispersion containing a prepolymerized second conductive polymer, taken out, and decompressed. Dry after treatment or at the same time as vacuum treatment. As a result, the second conductive polymer layer is formed on at least a portion of the first conductive polymer layer. The dispersion may include a binder and/or conductive inorganic particles (eg, a conductive carbon material such as carbon black).
　工程（ii）の少なくとも一部は、減圧した状態で行われる。減圧処理は、第２分散液を含浸させた陽極体を乾燥させる工程より前に行われることが望ましい。これにより、第１導電性高分子層と第２導電性高分子層との密着性を向上できる。 At least part of step (ii) is performed under reduced pressure. It is desirable that the decompression treatment be performed before the step of drying the anode body impregnated with the second dispersion. Thereby, the adhesion between the first conductive polymer layer and the second conductive polymer layer can be improved.
　例えば、図３に示すように、陽極体を第２分散液に浸漬し、溶液または分散液から陽極体を引き上げた後、第２分散液が付着した陽極体に対して、減圧処理を施してもよい。第２導電性高分子層の第１導電性高分子層との密着性が十分でなく、第１導電性高分子層の表面の凹部と第２導電性高分子層との間に隙間が形成されている場合であっても、減圧により隙間に存在する空気が抜け、流動性を有する第２導電性高分子層が第１導電性高分子層の凹部の隙間を埋め易くなる。また、減圧状態を解除することで、回復した大気圧により第２導電性高分子層が第１導電性高分子層の側に向かって押され、第１導電性高分子層の凹部を埋め易くなり、第１導電性高分子層と第２導電性高分子層との密着性が向上する。 For example, as shown in FIG. 3, the anode body is immersed in the second dispersion liquid, pulled up from the solution or the dispersion liquid, and then the anode body to which the second dispersion liquid has adhered is subjected to reduced pressure treatment. good too. Adhesion of the second conductive polymer layer to the first conductive polymer layer is not sufficient, and a gap is formed between the concave portion on the surface of the first conductive polymer layer and the second conductive polymer layer. Even in this case, the air present in the gaps is released by the reduced pressure, and the second conductive polymer layer having fluidity easily fills the gaps in the recesses of the first conductive polymer layer. In addition, by releasing the reduced pressure state, the recovered atmospheric pressure pushes the second conductive polymer layer toward the first conductive polymer layer, making it easier to fill the concave portions of the first conductive polymer layer. As a result, the adhesion between the first conductive polymer layer and the second conductive polymer layer is improved.
　また、陽極体を減圧状態に置いた後、減圧下で、陽極体を第２分散液に含浸してもよい。減圧により、第１導電性高分子層の凹部の空気が抜けた状態の陽極体を第２分散液に含浸させることにより、溶液または分散液が第１導電性高分子層の凹部に入り込み易くなり、第１導電性高分子層と第２導電性高分子層との密着性が向上する。 Alternatively, after placing the anode body in a reduced pressure state, the anode body may be impregnated with the second dispersion liquid under reduced pressure. By impregnating the anode body with the air removed from the recesses of the first conductive polymer layer under reduced pressure with the second dispersion liquid, the solution or dispersion liquid can easily enter the recesses of the first conductive polymer layer. , the adhesion between the first conductive polymer layer and the second conductive polymer layer is improved.
　図４は、本実施形態に係る電解コンデンサの製造方法において、固定電解質層の形成工程の他の例を示すフローチャートである。図４の例では、第２導電性高分子層の形成に引き続き、第３導電性高分子を含む第３分散液を陽極体に含侵させ、第３導電性高分子層を形成する工程（iii）が行われる。 FIG. 4 is a flow chart showing another example of the process of forming a fixed electrolyte layer in the method of manufacturing an electrolytic capacitor according to this embodiment. In the example of FIG. 4, following the formation of the second conductive polymer layer, the step of impregnating the anode body with a third dispersion containing the third conductive polymer to form the third conductive polymer layer ( iii) is performed.
　工程（iii）では、先ず、塩基性化合物を含む溶液または溶媒を陽極体に含侵させる。その後、乾燥により溶媒を除去し、第２導電性高分子層の表面に塩基性化合物を付着させる。塩基性化合物は、第２導電性高分子層の表面の凹凸に沿ってプレコートされる。溶媒は、例えば、水である。塩基性化合物としては、既に挙げた化合物（例えば、アミン化合物）から選択すればよい。塩基性化合物により、第２導電性高分子層と第３導電性高分子層との密着性を高められる。 In step (iii), first, the anode body is impregnated with a solution or solvent containing a basic compound. After that, the solvent is removed by drying, and the basic compound is attached to the surface of the second conductive polymer layer. A basic compound is pre-coated along the unevenness of the surface of the second conductive polymer layer. A solvent is, for example, water. The basic compound may be selected from the compounds already listed (eg, amine compounds). The basic compound can enhance the adhesion between the second conductive polymer layer and the third conductive polymer layer.
　その後、陽極体１を、予め重合された第３導電性高分子を含有している第３分散液に浸漬し、取り出して、乾燥させる。これにより、第３導電性高分子層が第２導電性高分子層の少なくとも一部に形成される。分散液には、バインダ、および／または導電性の無機粒子（例えば、カーボンブラックなどの導電性炭素材料）が含まれていてもよい。 After that, the anode body 1 is immersed in a third dispersion containing a prepolymerized third conductive polymer, taken out, and dried. Thereby, the third conductive polymer layer is formed on at least part of the second conductive polymer layer. The dispersion may include a binder and/or conductive inorganic particles (eg, a conductive carbon material such as carbon black).
　第２導電性高分子層と第３導電性高分子層との密着性を向上させるため、工程（iii）の少なくとも一部を、減圧した状態で行ってもよい。減圧処理は、第３分散液を含浸させた陽極体を乾燥させる工程より前に行われる。例えば、第３分散液を付着させた陽極体に対して、減圧処理を施してもよいし、減圧下で、陽極体を第３分散液に含浸してもよい。 In order to improve the adhesion between the second conductive polymer layer and the third conductive polymer layer, at least part of step (iii) may be performed under reduced pressure. The decompression treatment is performed before the step of drying the anode body impregnated with the third dispersion. For example, the anode body to which the third dispersion is adhered may be subjected to reduced pressure treatment, or the anode body may be impregnated with the third dispersion under reduced pressure.
　工程（iii）において第２導電性高分子層の表面に塩基性化合物を付着させる場合、工程（ii）において、第１導電性高分子層の表面に塩基性化合物を付着させなくてもよい。 When the basic compound is attached to the surface of the second conductive polymer layer in step (iii), the basic compound may not be attached to the surface of the first conductive polymer layer in step (ii).
　第２および第３導電性高分子には、ドーパントが含まれていてもよい。導電性高分子およびドーパントとしては、それぞれ、固体電解質層４について例示したものから選択すればよい。バインダは、公知のものを利用できる。分散液は、固体電解質層を形成する際に使用される公知の添加剤を含んでもよい。 A dopant may be contained in the second and third conductive polymers. The conductive polymer and dopant may be selected from those exemplified for the solid electrolyte layer 4, respectively. A known binder can be used. The dispersion may contain known additives used in forming the solid electrolyte layer.
（１ｄ）カーボン層および導電性樹脂層の形成工程
　続いて、固体電解質層４の表面に、カーボンペーストおよび金属ペーストを順次、塗布することにより、カーボン層５ａと金属ペースト層５ｂとで構成される陰極層５を形成する。陰極層５の構成は、これに限られず、集電機能を有する構成であればよい。 (1d) Step of forming a carbon layer and a conductive resin layer Subsequently, a carbon paste and a metal paste are sequentially applied to the surface of the solid electrolyte layer 4 to form a carbon layer 5a and a metal paste layer 5b. A cathode layer 5 is formed. The configuration of the cathode layer 5 is not limited to this, as long as it has a current collecting function.
（２）コンデンサ素子とリード端子との電気的接続工程
　次に、陽極リード端子１３と陰極リード端子１４とを準備する。陽極体１から植立する陽極ワイヤ２の第二部分２ｂを、レーザ溶接や抵抗溶接などにより、陽極リード端子１３と接合する。また、陰極層５に導電性接着材８を塗布した後、陰極リード端子１４を、導電性接着材８を介して陰極部７に接合する。 (2) Step of Electrically Connecting Capacitor Element and Lead Terminal Next, anode lead terminal 13 and cathode lead terminal 14 are prepared. A second portion 2b of anode wire 2 erected from anode body 1 is joined to anode lead terminal 13 by laser welding, resistance welding, or the like. After the conductive adhesive 8 is applied to the cathode layer 5 , the cathode lead terminal 14 is joined to the cathode portion 7 via the conductive adhesive 8 .
　続いて、コンデンサ素子１０および外装体１１の材料（例えば、未硬化の熱硬化性樹脂およびフィラー）を金型に収容し、トランスファー成型法、圧縮成型法等により、コンデンサ素子１０を封止する。このとき、陽極リード端子１３および陰極リード端子１４の一部を金型から露出させる。成型の条件は特に限定されず、使用される熱硬化性樹脂の硬化温度等を考慮して、適宜、時間および温度条件を設定すればよい。 Subsequently, the materials of capacitor element 10 and exterior body 11 (for example, uncured thermosetting resin and filler) are placed in a mold, and capacitor element 10 is sealed by transfer molding, compression molding, or the like. At this time, the anode lead terminal 13 and the cathode lead terminal 14 are partly exposed from the mold. The molding conditions are not particularly limited, and the time and temperature conditions may be appropriately set in consideration of the curing temperature of the thermosetting resin used.
　最後に、陽極リード端子１３および陰極リード端子１４の露出部分を、外装体１１に沿って折り曲げ、屈曲部を形成する。これにより、陽極リード端子１３および陰極リード端子１４の一部が外装体１１の搭載面に配置される。
　以上の方法により、電解コンデンサ２０が製造される。 Finally, the exposed portions of anode lead terminal 13 and cathode lead terminal 14 are bent along exterior body 11 to form bent portions. As a result, a part of anode lead terminal 13 and cathode lead terminal 14 is arranged on the mounting surface of package 11 .
The electrolytic capacitor 20 is manufactured by the above method.
［実施例］
　以下、本発明を実施例および比較例に基づいて具体的に説明するが、本発明は以下の実施例に限定されるものではない。 [Example]
EXAMPLES The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to the following examples.
　下記の要領で電解コンデンサを作製した。
（陽極体の形成）
　弁作用金属としてタンタル金属粒子を用いた。タンタル金属からなる陽極ワイヤの一端がタンタル金属粒子に埋め込まれるように、タンタル金属粒子を直方体に成形し、その後、成形体を真空中で焼結した。これにより、タンタルの多孔質焼結体からなる陽極体（１．７ｍｍ×３．３ｍｍ×４．４ｍｍ）と、陽極体に一端が埋設され、残りの部分が陽極体の一面から植立した陽極ワイヤと、を含む陽極部を得た。 An electrolytic capacitor was produced in the following manner.
(Formation of anode body)
Tantalum metal particles were used as the valve action metal. The tantalum metal particles were formed into a rectangular parallelepiped so that one end of the anode wire made of tantalum metal was embedded in the tantalum metal particles, and then the compact was sintered in vacuum. As a result, an anode body (1.7 mm × 3.3 mm × 4.4 mm) made of a porous sintered body of tantalum and an anode having one end embedded in the anode body and the remaining portion planted from one surface of the anode body An anode part containing a wire was obtained.
　続いて、電解水溶液であるリン酸水溶液が満たされた化成槽に、陽極体および陽極体から植立した陽極ワイヤの一部を浸漬し、陽極ワイヤの他端を化成槽の陽極体に接続した。そして、陽極酸化を行うことにより、陽極体の表面（孔の内壁面を含む多孔質焼結体の表面）および陽極ワイヤの一部の表面に、酸化タンタル（Ｔａ２Ｏ５）の均一な誘電体層を形成した。 Subsequently, the anode body and part of the anode wire planted from the anode body were immersed in a chemical bath filled with an aqueous solution of phosphoric acid, which was an electrolytic aqueous solution, and the other end of the anode wire was connected to the anode body in the chemical bath. . Then, by performing anodization, a uniform dielectric of tantalum oxide (Ta 2 O 5 ) is formed on the surface of the anode body (the surface of the porous sintered body including the inner wall surfaces of the pores) and a part of the surface of the anode wire. form the body layer.
　次に、第１導電性高分子の原料である３，４－エチレンジオキシチオフェンと、ｐ－トルエンスルホン酸鉄（ＩＩＩ）と、１－ブタノ－ルとを混合し、第１溶液を調製した。第１溶液に陽極体を浸漬した後、陽極体を第１溶液から引き上げ、大気中で熱処理を行った。この場合、ｐ－トルエンスルホン酸鉄（ＩＩＩ）は、酸化剤として機能する。このようにして、誘電体層上にポリ（３，４－エチレンジオキシチオフェン）（ＰＥＤＯＴ）を含む固体電解質層を、第１導電性高分子層として形成した。 Next, 3,4-ethylenedioxythiophene, iron (III) p-toluenesulfonate, and 1-butanol, which are raw materials for the first conductive polymer, were mixed to prepare a first solution. . After the anode body was immersed in the first solution, the anode body was taken out of the first solution and heat-treated in the air. In this case, iron (III) p-toluenesulfonate functions as an oxidizing agent. Thus, a solid electrolyte layer containing poly(3,4-ethylenedioxythiophene) (PEDOT) was formed as the first conductive polymer layer on the dielectric layer.
　続いて、アミン化合物であるＮ，Ｎ－ジメチルオクチルアミンの水溶液に陽極体を浸漬した後、陽極体を引き上げ、１３０℃で１０分、大気中で乾燥させた。 Subsequently, after the anode body was immersed in an aqueous solution of N,N-dimethyloctylamine, which is an amine compound, the anode body was pulled out and dried in the air at 130°C for 10 minutes.
　次に、第２導電性高分子としてのポリ（３，４－エチレンジオキシチオフェン）と、ポリスチレンスルホン酸塩と、水とを混合し、第２分散液を調製した。第２分散液に陽極体を浸漬した後、陽極体を第２分散液から引き上げ、減圧処理を施した。減圧処理後、大気圧下で、８０℃で２０分の乾燥処理を行い、第２導電性高分子層を形成し、陽極体Ａ１～Ａ５を得た。 Next, poly(3,4-ethylenedioxythiophene) as the second conductive polymer, polystyrene sulfonate, and water were mixed to prepare a second dispersion. After the anode body was immersed in the second dispersion, the anode body was lifted out of the second dispersion and subjected to reduced pressure treatment. After the decompression treatment, drying treatment was performed at 80° C. for 20 minutes under atmospheric pressure to form a second conductive polymer layer, thereby obtaining anode bodies A1 to A5.
　陽極体Ａ１～Ａ５では、減圧処理における圧力および減圧時間を表１に示す通り変化させた。また、陽極体Ａ１～Ａ５と同様の製造方法で、減圧処理を施さないで陽極体を製造し、陽極体Ｂ１を得た。表１において、減圧処理における圧力は、大気圧を基準とした相対圧（すなわち、ゲージ圧）で示す。 For the anode bodies A1 to A5, the pressure and the decompression time in the decompression process were changed as shown in Table 1. Further, an anode body was manufactured by the same manufacturing method as that for the anode bodies A1 to A5 without performing the decompression treatment, thereby obtaining the anode body B1. In Table 1, the pressure in the depressurization process is indicated by relative pressure (that is, gauge pressure) based on the atmospheric pressure.
　陽極体Ａ１～Ａ５およびＢ１について、それぞれ４６個のサンプルを作製し、後工程を想定した１００℃以上での熱処理を行った。熱処理後、導電性高分子層に膨れが発生しているかを目視で確認した。４６個のサンプルのうち、膨れが発生したサンプルの個数Ｎを求め、（Ｎ／４６）×１００を膨れ発生率（％）として評価した。評価結果を表１に示す。表１より、減圧処理を施した陽極体Ａ１～Ａ５では、第１導電性高分子層と第２導電性高分子層との密着性が高められており、結果、導電性高分子層の膨れの発生が顕著に抑制されていることが分かる。なお、陽極体Ａ５において膨れ発生率がＡ１～Ａ４と比べて増加したのは、長時間の減圧により分散液に含まれる水分が揮発し、気泡が発生し易くなっており、第２導電性高分子層と第１導電性高分子層との表面状態が劣化したためと考えられる。 Forty-six samples of each of the anode bodies A1 to A5 and B1 were prepared and subjected to heat treatment at 100°C or higher assuming the post-process. After the heat treatment, it was visually confirmed whether swelling occurred in the conductive polymer layer. Among the 46 samples, the number N of samples in which swelling occurred was determined, and (N/46)×100 was evaluated as the rate of occurrence of swelling (%). Table 1 shows the evaluation results. From Table 1, it can be seen that the anode bodies A1 to A5 subjected to the decompression treatment have improved adhesion between the first conductive polymer layer and the second conductive polymer layer, and as a result, the conductive polymer layer swells. It can be seen that the occurrence of is remarkably suppressed. The reason why the rate of blistering in the anode body A5 was higher than that in the anode body A1 to A4 is that the moisture contained in the dispersion volatilizes due to the pressure reduction for a long time, making it easy to generate air bubbles. It is considered that the surface conditions of the molecular layer and the first conductive polymer layer deteriorated.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　本発明は、電解コンデンサに利用可能であり、好適には、多孔体を陽極体に用いる電解コンデンサに利用することができる。 The present invention can be used for electrolytic capacitors, preferably for electrolytic capacitors using a porous body as an anode body.
　本発明を現時点での好ましい実施態様に関して説明したが、そのような開示を限定的に解釈してはならない。種々の変形および改変は、上記開示を読むことによって本発明に属する技術分野における当業者には間違いなく明らかになるであろう。したがって、添付の請求の範囲は、本発明の真の精神および範囲から逸脱することなく、すべての変形および改変を包含する、と解釈されるべきものである。 Although the present invention has been described in terms of its presently preferred embodiments, such disclosure should not be construed as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art to which the invention pertains after reading the above disclosure. Therefore, the appended claims are to be interpreted as covering all variations and modifications without departing from the true spirit and scope of the invention.
２０：電解コンデンサ
　１０：コンデンサ素子
　　　１：陽極体
　　　２：陽極ワイヤ
　　　　２ａ：第一部分
　　　　２ｂ：第二部分
　　　３：誘電体層
　　　４：固体電解質層
　　　５：陰極層
　　　　５ａ：カーボン層
　　　　５ｂ：金属ペースト層
　　　６：陽極部
　　　７：陰極部
　　　８：導電性接着材
　１１：外装体
　１３：陽極リード端子
　１４：陰極リード端子
　　１４ａ：接合部
  20: Electrolytic capacitor 10: Capacitor element 1: Anode body 2: Anode wire 2a: First part 2b: Second part 3: Dielectric layer 4: Solid electrolyte layer 5: Cathode layer 5a: Carbon layer 5b: Metal paste layer 6: Anode part 7: Cathode part 8: Conductive adhesive 11: Exterior body 13: Anode lead terminal 14: Cathode lead terminal 14a: Joining part

Claims (7)

  1. 　多孔質の陽極体と、前記陽極体の表面に形成された誘電体層と、前記誘電体層の少なくとも一部を覆う固体電解質層と、前記固体電解質層の少なくとも一部を覆う陰極層と、を備える電解コンデンサの製造方法であって、
    　前記誘電体層が形成された前記陽極体の表面に導電性高分子を含む前記固体電解質層を形成する工程を有し、
    　前記固体電解質層の形成工程は、
    　第１導電性高分子の原料となる第１モノマーを含む第１溶液を、前記陽極体に含侵させ、前記誘電体層の表面で前記第１モノマーを重合させて、前記誘電体層を覆う第１導電性高分子層を形成する第１工程と、
    　第２導電性高分子を含む第２溶液または第２分散液を、前記陽極体に含侵させ、前記第１導電性高分子層を覆う第２導電性高分子層を形成する第２工程と、を有し、
    　前記第２工程は、前記陽極体を減圧処理することを含む、電解コンデンサの製造方法。     a porous anode body, a dielectric layer formed on the surface of the anode body, a solid electrolyte layer covering at least part of the dielectric layer, a cathode layer covering at least part of the solid electrolyte layer, A method for manufacturing an electrolytic capacitor comprising
    forming the solid electrolyte layer containing a conductive polymer on the surface of the anode body on which the dielectric layer is formed;
    The step of forming the solid electrolyte layer includes:
    The anode body is impregnated with a first solution containing a first monomer as a raw material of the first conductive polymer, and the first monomer is polymerized on the surface of the dielectric layer to cover the dielectric layer. a first step of forming a first conductive polymer layer;
    a second step of impregnating the anode body with a second solution or second dispersion containing a second conductive polymer to form a second conductive polymer layer covering the first conductive polymer layer; , has
    The method for manufacturing an electrolytic capacitor, wherein the second step includes subjecting the anode body to decompression treatment.
  2. 　前記第２工程では、減圧下で、前記第２溶液または前記第２分散液を前記陽極体に含侵させる、請求項１に記載の電解コンデンサの製造方法。 2. The method for manufacturing an electrolytic capacitor according to claim 1, wherein in the second step, the anode body is impregnated with the second solution or the second dispersion under reduced pressure.
  3. 　前記第２工程では、前記第２溶液または前記第２分散液が付着した前記陽極体を減圧下に置き、前記第２溶液または前記第２分散液を前記陽極体に含侵させる、請求項１に記載の電解コンデンサの製造方法。 2. In the second step, the anode body to which the second solution or the second dispersion has adhered is placed under reduced pressure to impregnate the anode body with the second solution or the second dispersion. A method for manufacturing the electrolytic capacitor according to 1.
  4. 　前記第２工程では、前記第２溶液または前記第２分散液を前記陽極体に含侵させる前に、塩基性化合物を含む溶液または溶媒を前記陽極体に含侵させる、請求項１～３のいずれか１項に記載の電解コンデンサの製造方法。 4. The method of claim 1, wherein in the second step, the anode body is impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the second solution or the second dispersion. A method for manufacturing an electrolytic capacitor according to any one of items 1 to 3.
  5. 　前記固体電解質層の形成工程は、
    　前記第２工程の後に、第３導電性高分子を含む第３溶液または第３分散液を、前記陽極体に含侵させ、第３導電性高分子層を形成する第３工程をさらに有し、
    　前記第３工程では、前記第３溶液または前記第３分散液を前記陽極体に含侵させる前に、塩基性化合物を含む溶液または溶媒を前記陽極体に含侵させる、請求項１～３のいずれか１項に記載の電解コンデンサの製造方法。     The step of forming the solid electrolyte layer includes:
    After the second step, the method further includes a third step of impregnating the anode body with a third solution or dispersion containing a third conductive polymer to form a third conductive polymer layer. ,
    The method according to any one of claims 1 to 3, wherein in the third step, the anode body is impregnated with a solution or solvent containing a basic compound before impregnating the anode body with the third solution or the third dispersion. A method for manufacturing an electrolytic capacitor according to any one of items 1 to 3.
  6. 　前記第２工程において、塩基性化合物を含む溶液または溶媒を前記陽極体に含侵させない、請求項５に記載の電解コンデンサの製造方法。 The method for manufacturing an electrolytic capacitor according to claim 5, wherein in the second step, the anode body is not impregnated with a solution or solvent containing a basic compound.
  7. 　前記第３導電性高分子は、前記第２導電性高分子を構成するモノマーユニットと同じモノマーユニットを含む、請求項５または６に記載の電解コンデンサの製造方法。
          7. The method for manufacturing an electrolytic capacitor according to claim 5, wherein said third conductive polymer contains the same monomer units as those constituting said second conductive polymer.
PCT/JP2022/045965 2021-12-24 2022-12-14 Method for producing electrolytic capacitor WO2023120309A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010040776A (en) * 2008-08-05 2010-02-18 Nec Tokin Corp Conductive polymer suspension and method of preparing the same, conductive polymer material, electrolytic capacitor, and solid electrolytic capacitor and method of manufacturing the same
JP2012043958A (en) * 2010-08-19 2012-03-01 Nec Tokin Corp Solid electrolytic capacitor and manufacturing method thereof
WO2017002351A1 (en) * 2015-06-30 2017-01-05 パナソニックＩｐマネジメント株式会社 Electrolytic capacitor and method for manufacturing same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010040776A (en) * 2008-08-05 2010-02-18 Nec Tokin Corp Conductive polymer suspension and method of preparing the same, conductive polymer material, electrolytic capacitor, and solid electrolytic capacitor and method of manufacturing the same
JP2012043958A (en) * 2010-08-19 2012-03-01 Nec Tokin Corp Solid electrolytic capacitor and manufacturing method thereof
WO2017002351A1 (en) * 2015-06-30 2017-01-05 パナソニックＩｐマネジメント株式会社 Electrolytic capacitor and method for manufacturing same

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