JP5104008B2 - Electrolytic capacitor - Google Patents

Description

  The present invention relates to an electrolytic capacitor that is small in size and capable of large capacity.

  An electrolytic capacitor is an electronic component widely used in electronic devices, and generally has the following configuration.

  The action of having a withstand voltage when a voltage is applied in one direction but losing the withstand voltage when a voltage is applied in the opposite direction is referred to as a so-called valve action. Used, an insulating oxide film is formed on the anode surface by anodizing.

  This oxide film becomes a dielectric layer, and an electrolyte such as an electrolytic solution or a conductive polymer or a solid electrolyte is in contact with the oxide film as a substantial cathode.

  In the wound capacitor, the electrolyte is held by electrolytic paper (separator) or the like. In a flat capacitor, metal particles containing carbon paste or resin material are sequentially formed as a cathode layer on an electrolyte.

  In both types of electrolytic capacitors, the cathode-side electrode is drawn from the cathode made of metal such as aluminum.

  The anode side electrode and the cathode side electrode are generally made of foil cut into a strip shape, and in a winding type, this is wound together with a separator to form a capacitor element. In the flat plate type, a square anode side electrode, a cathode layer, a cathode side electrode, and the like are stacked to form a capacitor element. Further, a laminate type is formed by laminating the capacitor elements.

  Further, the cathode layer is connected to an extraction electrode mainly made of a metal that is electrically connected to the outside, and is drawn out from various exteriors covering the capacitor element.

  Here, the electrolytic capacitor is characterized in that since the dielectric layer is made of an extremely thin oxide film layer, the capacitance value per unit area of the electrode is high, and a small and large capacitance can be obtained. However, along with the downsizing of electronic equipment, there is a demand for smaller and larger capacity electrolytic capacitors.

  In order to increase the electrolytic capacitor capacity, the surface of the electrode has been roughened by etching to increase the surface area. However, the surface area enlargement due to the roughening is approaching the limit in recent years, and new measures for increasing the capacitance are required.

  For example, if the capacity per unit area is increased, that is, if the etching pit shape is narrowed and the aluminum foil is deep in the center of the aluminum foil, the capacity per unit area can be increased.

  However, when the capacity of the unit area is increased as described above, the entire aluminum foil is covered with the etching pits, the electrode foil becomes brittle, and the electrode foil strength is reduced.

  On the other hand, as one method, in order to increase the surface area of the electrode foil while maintaining the foil strength, a thick aluminum foil is etched to increase the capacity per unit area. In this method, the capacity of the unit area is large. However, when a general wound electrolytic capacitor is made using the above electrode foil, the thickness of the electrode foil is so large that the length of the usable electrode foil is reduced. Limitation occurs, and an element that cannot be stored in the case is formed.

  Furthermore, in the case of a multilayer solid electrolytic capacitor, there are restrictions on the height due to the nature of its shape, and the height cannot be increased unnecessarily. For foils with reduced strength, the welding conditions during lamination cannot be set easily, and the strength after welding also becomes problematic.

  For this reason, if the capacity is increased, the number of laminated layers must be increased or a thick electrode foil must be used, resulting in an increase in the height of the capacitor.

In addition to the above general prior art, in the case of a wound electrolytic capacitor, paying attention to the fact that the capacity is calculated by the combined capacity, as described in Patent Document 1, the deposition of metal nitride on the surface of the substrate is performed. A method of increasing the capacity by forming a film is known. Alternatively, as described in Patent Document 2, using a foil in which carbon is physically in contact with the cathode, the capacity on the cathode side is canceled, and only the capacity on the anode side is reflected in the composite capacity, thereby increasing the capacity. A method has been proposed.
Japanese Patent Laid-Open No. 2-117123 Patent 3,875,705

  However, even if these conventional methods are used, in order to further increase the capacity demanded from the market in the future, an anode material capable of realizing a large capacity while maintaining the same thickness, strength and pressure resistance as the current situation is available. Without this, it is not possible to obtain an electrolytic capacitor that can sufficiently cope.

  Therefore, an object of the present invention is to present an anode electrode foil structure that dramatically increases the anode foil surface area related to the capacitance of the capacitor while maintaining the same thickness, strength, and breakdown voltage as in the past, and to adopt this structure. It is to provide an electrolytic capacitor having a capacity.

In order to achieve the above object, a first aspect of the present invention includes an anode foil made of a metal having a valve action, a cathode layer, and an electrolyte layer interposed between the anode foil and the cathode layer. An electrolytic capacitor is characterized in that it has a dielectric oxide film layer formed by depositing particles having a dielectric constant by an aerosol deposition method on the surface of the anode foil.

  In this first aspect, as a preferred embodiment, the anode foil is a flat rolled aluminum foil or an aluminum foil having an etched rough surface, and has the dielectric constant of the deposited layer deposited on the anode foil. The particles can be valve metal particles based on the valve metal.

  Furthermore, in the first aspect, as a preferred embodiment, the particles having the dielectric constant of the deposited layer deposited on the anode foil may further include ceramic particles containing ceramic as a main component.

  According to the present invention having such a configuration, it is possible to have a deposited layer in which valve metal particles having a large dielectric constant are deposited on the surface of the anode foil by the aerosol deposition method. An anode foil having a large surface area per unit area of the foil is obtained.

  Therefore, an electrolytic capacitor using such an anode foil as the anode electrode has a higher electrostatic capacity than a conventional electrolytic capacitor, and can provide a small and large-capacity electrolytic capacitor.

  It is possible to further increase the surface area of the deposited layer and the anode foil by further etching the deposited layer and the anode foil on which the valve metal particles are deposited by the aerosol deposition method described above. Is possible. The anode foil may be etched before the particle deposition step by the aerosol deposition method as described above.

  The withstand voltage can be ensured by subjecting the electrode foil subjected to the above treatment to chemical conversion treatment at an appropriate applied voltage. In addition, compared to ordinary etching conversion foil, the aerosol deposition method can adjust the spraying speed and spraying time to adjust the thickness of the deposited layer of valve metal particles. Is an advantage.

  By using the anode foil prepared by such a manufacturing method as the anode foil of a wound electrolytic capacitor, a single layer capacitor, and a multilayer capacitor, it is possible to realize a large capacity of these capacitors.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing the structure of a wound electrolytic capacitor as one embodiment to which the present invention is applied.

  In FIG. 1, (a) is an external appearance, and (b) is a diagram in which the exterior (metal case) 10 is removed and the inside is observed in a perspective manner. An anode electrode lead 12 and a cathode electrode lead 13 are fixed to a sealing body (insulating resin) 11.

  The wound capacitor element 20 is fixed to the sealing body (insulating resin) 11 in the exterior (metal case) 1, and the anode electrode lead 12 and the cathode electrode lead 13 are respectively attached to the anode foil 21 and the cathode foil 22. Electrically connected.

  The anode foil 21 and the cathode foil 22 are wound into a cylindrical shape via an electrolytic paper 23 as a separator, and the terminal portion is fixed with a winding tape 24 to maintain the wound state.

  The electrolytic capacitor of the present invention realizes a higher capacity than a conventional electrolytic capacitor using an etched electrode foil obtained by electrolytic etching of an aluminum foil serving as an anode foil.

  As a feature, ultrafine powder of metal on the surface of a conventional etched electrode foil, ultrafine powder having a high dielectric constant together with the ultrafine powder of metal, or ultrafine powder obtained by oxidizing the surface of a valve metal is used. The gas is uniformly diffused in a high-speed gas, and the gas is sprayed onto the surface of the etched electrode foil, which is the object, to form a molded film of ultrafine powder.

  This makes it possible to use an electrode foil in which the surface area of the aluminum is expanded with the same thickness of the electrode foil as compared with the conventional etched electrode foil of a single aluminum foil. In addition, the ultrafine powder molded film formed on the etched electrode foil surface may be electrolytically etched.

  By these treatments, it is possible to use an electrode foil in which the surface area of aluminum is further expanded in an electrode foil having the same thickness as compared with a conventional etched electrode foil of a single aluminum foil.

  With such a characteristic configuration of the present invention, it is possible to provide a small and large capacity electrolytic capacitor.

  The following features according to the present invention will be described in more detail based on examples.

  FIG. 2 is a schematic diagram showing a cross-sectional structure of the wound capacitor element 20 in FIG. The anode foil 21 and the cathode foil 22 are superposed via an electrolytic paper 30 that is a separator impregnated with an electrolyte 31.

  The cathode foil 22 can be configured to include at least one of electrolytic paper, carbon, metal foil, metal particles, and conductive resin.

  Furthermore, as the electrolyte 31, an electrolytic solution in which an organic acid salt or an inorganic acid salt is dissolved in a proton solvent can be used. Further, as a specific example of the electrolyte 31, a solid electrolytic capacitor can be obtained by using at least one of polythiophene-based, polypyrrole-based, polyaniline-based conductive polymer, and TCNQ complex salt solid electrolyte.

  Here, the electrolytic capacitor according to the present invention is particularly characterized in that the dielectric oxide film layer 200 on the surface of the anode foil 21 is formed.

[First Anode Foil Forming Method]
FIG. 3 is a diagram showing a procedure of a forming method of the first embodiment of the dielectric oxide film layer 200 formed on the surface of the anode foil 21. A state diagram corresponding to the processing steps is shown on the left side of the flow.

  An aluminum foil 21 having a purity of 99% by a rolling method having a thickness of 40 μm was prepared (Step S1: State I).

  Surface treatment was performed on the prepared aluminum foil 21 in an aerosol deposition chamber as follows. FIG. 4 is a diagram showing a schematic configuration example of the aerosol deposition chamber.

  The film forming chamber 303 has a stage 304 movable in the X and Y directions, and the rolled aluminum foil 21 prepared in step S1 is attached to the stage 304 (step S2).

  The inside of the film forming chamber 303 was evacuated by a vacuum pump 306 and depressurized to 10 Pa or less in advance (step S3).

  On the other hand, a raw material powder 300 mainly composed of Al powder, which is a valve metal having an average particle diameter of 8 μm, is placed in an aerosol generating container 301A, and ultrasonic waves are applied to the entire aerosol generating container 301A by a vibrator 301B and heated at about 150 degrees. Then, vacuum treatment was performed for 30 minutes, and a pretreatment was performed to remove moisture formed on the powder surface (step S4).

High-purity helium gas (gas pressure: 2 kg / cm ² , gas flow rate: 10 l / min.) 302 was introduced into the aerosol generator 301A, and the raw material powder 300 subjected to pretreatment was aerosolized (step S5).

  Next, this aerosol is fed into the film forming chamber 303 through a pipe by a nozzle 305. The nozzle 305 used was a spiral groove formed inside. Injection was performed for 3 minutes from the nozzle 305 having a spiral groove on the inner side toward the substrate aluminum foil 21 (step S6). The pressure in the chamber at this time was kept constant at 500 Pa.

  Thus, the Al film 201A formed on the upper surface of the substrate aluminum foil 21 by aerosol deposition with aluminum fine particles had a thickness of 20 μm (state II: aerosol deposition with aluminum fine particles).

  It is also possible to form an aluminum film on both surfaces of the substrate aluminum foil 21 in the manner described above.

Subsequently, a pre-sintering treatment for densifying the deposited aluminum metal particles was performed by annealing in an inert gas at 300 ° C. which is lower than (melting point + 100 ° C.) of the aluminum. This foil was subjected to an electrolytic treatment in hydrochloric acid, nitric acid, an AlCl ₃ aqueous solution at a current density of 0.2 A / m ² (50 Hz) for 8 minutes, and a roughening treatment (etching) was performed (step S7). By this etching process, a fine cavity layer 201B was formed (state III).

  Thereafter, chemical conversion treatment was performed in an aqueous solution of ammonium adipate (step S8).

  By this treatment, the surface area is enlarged by forming the fine cavity layer 201B, and the surface 201C of the fine cavity layer 201B is oxidized by the chemical conversion treatment in step S8, so that the dielectric oxide film layer 200 having a large dielectric constant becomes the substrate aluminum foil 21. (State IV).

[Second Anode Foil Forming Method]
Here, in the embodiment according to the flow of FIG. 3 described above, an example in which a substrate aluminum foil having a thickness of 40 μm of 99% by a rolling method is used as the anode foil 21 has been described. Further, as a second embodiment, FIG. As shown, an etched aluminum foil having a pre-etched rough surface (etched surface) 201 that is also used in the prior art may be used.

  FIG. 6 is a flowchart showing the procedure of the method for manufacturing the electrode foil of the second embodiment according to the present invention.

A 99% aluminum foil having a thickness of 40 μm was annealed at 300 ° C. in an inert gas and pretreated. The foil was subjected to an electrolytic treatment in an aqueous solution of hydrochloric acid, nitric acid, and AlCl ₃ at a current density of 0.2 A / m ² (50 Hz) for 8 minutes to roughen the surface. Thereby, the aluminum foil 21 having the etched surface 201 shown in the cross section of the aluminum foil in FIG. 5A was obtained (step S1).

  Then, the roughened aluminum foil was subjected to the processing from step S2 to step S8 in the same manner as the processing flow of FIG. 2 described for the first embodiment. However, the etching process in step S7 in FIG. 2 was omitted.

  It is also possible to form an aluminum film on both surfaces of the etched aluminum foil in the manner described above.

  FIG. 5B schematically shows a cross section of a layer 202 obtained by the above-described treatment, in which aluminum fine particles are deposited by aerosol deposition on a rough surface 201 that has been previously etched.

[Third anode foil forming method]
FIG. 7 is a flowchart showing the procedure of the method for manufacturing the electrode foil of the third embodiment according to the present invention. Similar to the second embodiment, 99% aluminum foil 40 μm thick by rolling was annealed at 300 ° C. in an inert gas and pretreated. The foil was subjected to an electrolytic treatment in an aqueous solution of hydrochloric acid, nitric acid, and AlCl ₃ at a current density of 0.2 A / m ² (50 Hz) for 8 minutes to roughen the surface. Thereby, etched aluminum foil 21 having rough surface (etched surface) 201 in FIG. 5A was obtained (step S1).

  Surface treatment was performed on the etched aluminum foil 21 (see FIG. 5A) in the aerosol deposition chamber shown in FIG. 4 according to the flow of FIG.

  The rolled aluminum foil 21 prepared in Step S1 is attached to the stage 304 that can move in the X and Y directions in the film forming chamber 303 (Step S2).

  The inside of the film forming chamber 303 was evacuated by a vacuum pump 306 and depressurized to 10 Pa or less in advance (step S3).

  On the other hand, an ultrafine ceramic made of barium titanate having an average particle diameter of 100 nm is placed as a raw powder 300 in an aerosol generating container 301A, and ultrasonic waves are applied to the entire aerosol generating container 301A by a vibrator 301B and heated at about 150 degrees, A pretreatment for removing moisture formed on the powder surface was performed by vacuum degassing for 30 minutes (step S4).

High-purity helium gas (gas pressure: 2 kg / cm ² , gas flow rate: 10 l / min.) 302 was introduced into the aerosol generator 301A, and the raw material powder 300 subjected to pretreatment was aerosolized (step S5).

  Next, this aerosol is fed into the film forming chamber 303 through a pipe by a nozzle 305. The nozzle 305 used was a spiral groove formed inside. Injection was performed for 3 minutes from the nozzle 305 having a spiral groove on the inner side toward the substrate aluminum foil 21 (step S6). The pressure in the chamber at this time was kept constant at 500 Pa.

In this way, the ceramic (barium titanate) film formed on the substrate aluminum foil 21 the upper surface by aerosol deposition by the ceramic fine particles, and a thickness of the 2 [mu] m.

  In addition, it is also possible to form a ceramic film on both surfaces of the substrate aluminum foil 21 in the above manner.

Subsequently, annealing was performed in an inert gas at 500 ° C., which is a temperature lower than (melting point + 100 ° C.) of the aluminum, and a sintering pretreatment for densifying the deposited metal particles was performed.

  Next, chemical conversion treatment was performed in an aqueous solution of ammonium adipate (step S8).

  Also in the third embodiment, the etching process in step S7 in FIG. 2 was omitted.

[Fourth anode foil forming method]
FIG. 8 is a flowchart showing the procedure of the method for manufacturing the electrode foil of the fourth embodiment according to the present invention. Similar to the second and third embodiments, a 99% aluminum foil having a thickness of 40 μm was annealed at 300 ° C. in an inert gas and subjected to pretreatment. The foil was subjected to an electrolytic treatment in an aqueous solution of hydrochloric acid, nitric acid, and AlCl ₃ at a current density of 0.2 A / m ² (50 Hz) for 8 minutes to roughen the surface. Thereby, etched aluminum foil 21 having rough surface 201 in FIG. 5A was obtained (step S1).

  Surface treatment was performed on the etched aluminum foil 21 (see FIG. 5A) in the aerosol deposition chamber shown in FIG. 4 according to the flow of FIG.

  The rolled aluminum foil 21 prepared in Step S1 is attached to the stage 304 that can move in the X and Y directions in the film forming chamber 303 (Step S2).

  The inside of the film forming chamber 303 was evacuated by a vacuum pump 306 and depressurized to 10 Pa or less in advance (step S3).

  On the other hand, a mixture of ultrafine ceramics composed of barium titanate with an average particle size of 100 nm and ultrafine aluminum particles with an average particle size of 8 μm is put as a raw material powder 300 in an aerosol generating container 301A and superposed on the entire aerosol generating container 301A by a vibrator 301B. A pretreatment was performed to remove moisture formed on the powder surface by vacuum degassing for 30 minutes while applying sonic waves and heating at about 150 degrees (step S4).

High-purity helium gas (gas pressure: 2 kg / cm ² , gas flow rate: 10 l / min.) 302 was introduced into the aerosol generator 301A, and the raw material powder 300 subjected to pretreatment was aerosolized (step S5).

  Next, this aerosol is fed into the film forming chamber 303 through a pipe by a nozzle 305. The nozzle 305 used was a spiral groove formed inside. Injection was performed for 3 minutes from the nozzle 305 having a spiral groove on the inner side toward the substrate aluminum foil 21 (step S6). The pressure in the chamber at this time was kept constant at 500 Pa.

  In this way, as shown in FIG. 9A, the ceramic (barium titanate) -aluminum film 202 formed on the rough surface 201 of the substrate aluminum foil 21 by the aerosol deposition by the ceramic fine particles 202a and the aluminum fine particles 202b is 20 μm. It was the thickness of.

  It is also possible to form a ceramic (barium titanate) ceramic-aluminum film on both surfaces of the substrate aluminum foil 21 in the manner described above.

  Next, chemical conversion treatment was performed in an aqueous solution of ammonium adipate (step S8).

  Next, in accordance with step S4 of FIG. 3, a heat treatment is performed, followed by a chemical conversion treatment, whereby the strong anode foil 21 having the aluminum oxide layer 201B formed on the surface and the dielectric oxide film layer 200 are formed. It is formed. Also in the fourth embodiment, the etching process in step S7 in FIG. 3 was omitted.

  According to the above embodiment, a larger surface area can be obtained by the rough surface 201 previously etched and the deposited layer 202 of the aluminum particles which are the valve metal particles 202a and the barium titanate particles which are the ceramic particles 202b. Therefore, the capacitance can be increased.

  As shown in FIG. 9B, the etching process of step S7 in FIG. 3 is performed to etch the particles with weak binding force and the inter-particle portions in the aerosol deposition film 202, thereby obtaining a porous structure of aluminum. Can do.

  Here, as the valve metal particles 202a, those containing at least one of valve metal aluminum and its compound, titanium and its compound, tantalum and its compound, niobium and its compound can be used.

  Furthermore, as the ceramic particles 202b, a material made of an oxide, nitride or carbide having a dielectric constant of 10 or more can be used in addition to the barium titanate particles.

  10A, 10B, and FIGS. 11A, 11B are examples in which the capacitor element generated by using the aerosol deposition method according to the present invention is applied to a multilayer and single-layer electrolytic capacitor instead of the winding type shown in FIG. FIG.

  FIG. 10A is a diagram showing a schematic structure inside the cross section of the two-terminal type unit capacitor element 100.

  Dielectric oxide film layers 200 are formed on both sides of the anode foil 21. The anode electrode terminal 12 is connected to one end side of the anode foil 21. The cathode foil 22 has a two-layer structure of a layer 22A containing metal particles and resin and a layer 22B containing carbon particles and resin. A cathode foil 22 having a two-layer structure is formed so as to surround one end and both sides of the anode foil 21.

  FIG. 10B is a cross-sectional view of an electrolytic capacitor in which the unit capacitor elements 100 of FIG. 10A are stacked. The exterior 10A is formed of an insulator case, and one end side of the exposed anode foil 21 of the laminated unit capacitor element 100 is connected to the anode electrode terminal 12 in common.

  The cathode electrode terminal 13 is electrically connected in common to the layer 22A containing metal particles and resin of the laminated unit capacitor element 100.

  As a result, an electrolytic capacitor having a two-terminal configuration is formed.

  FIG. 11A is a diagram showing a schematic structure inside a cross section of the three-terminal type unit capacitor element 100.

  Dielectric oxide film layers 200 are formed on both sides of the anode foil 21. Both ends of the anode foil 21 are connected to the anode electrode terminal 12, respectively. The cathode foil 22 has a two-layer structure of a layer 22A containing metal particles and resin and a layer 22B containing carbon particles and resin. A cathode foil 22 having a two-layer structure is formed so as to surround the dielectric oxide film layer 200 around the anode foil 21.

  FIG. 11B is a cross-sectional view of an electrolytic capacitor in which the unit capacitor elements 100 of FIG. 11A are stacked. The exterior 10A is formed of a conductive metal case, and both ends of the anode foil 21 of the laminated unit capacitor element 100 are commonly connected to the anode electrode terminals 12A and 12B, respectively.

  The cathode electrode terminal 13 is electrically connected through the cathode foil layer 22A containing the metal particles and resin of the unit capacitor element 100 and the conductive resin 101 that fixes the laminated unit capacitor element 100. As a result, an electrolytic capacitor having a three-terminal configuration is formed.

  Here, in the electrolytic capacitor formed using the anode foil 21 in which the dielectric oxide film layer 200 according to the present invention is formed, the comparison result of the effects caused by the difference in the structure of the dielectric oxide film layer 200 is shown. It is shown in 1.

  In Table 1 below, comparative examples to be compared with the first to fourth examples were implemented as follows.

A 99% aluminum foil having a thickness of 40 μm was annealed at 300 ° C. in an inert gas and pretreated. The foil was subjected to an electrolytic treatment in an aqueous solution of hydrochloric acid, nitric acid, and AlCl ₃ at a current density of 0.2 A / m ² (50 Hz) for 8 minutes to roughen the surface. Thereafter, chemical conversion treatment was performed in an aqueous solution of ammonium adipate.

  That is, in the comparative example, the surface roughening process is not performed by forming a film with the aluminum fine particles or ceramic fine particles in steps S2 to S7 in the processing flow of the first embodiment.

  Furthermore, as a measurement condition, the leakage current at the time of 30 minutes after reaching the predetermined voltage 20V was measured for the anode foil produced in each example. The tensile strength of the film was also measured.

  At this time, a test piece with a width of 1 cm and a length of 5 cm was cut out and pulled at 10 mm / min with a tensile tester, and the breaking strength was 1.5 kg / cm (not normalized with the thickness, but the two-dimensional shape of the test piece) If it is equal to or greater than the above), the measurement was accepted. In addition, the tensile strength of the foil was measured.

上記表１において，第２〜第４の実施例の箔の引張強度は比較例１より向上している。単位面積あたりの静電容量は比較例１の４０μＦに対して，第２〜第４の実施例では１５０〜１８０μＦといずれも４倍程度となっている。

In Table 1 above, the tensile strength of the foils of the second to fourth examples is higher than that of Comparative Example 1. The electrostatic capacity per unit area is about 4 times that of 40 μF in Comparative Example 1 and 150 to 180 μF in the second to fourth embodiments.

  Therefore, according to the present invention, it is possible to provide an electrolytic capacitor having a capacitance about four times that of the prior art.

  The aerosol deposition method is also advantageous in that it is possible to adjust the type and compounding ratio of valve metal particles to be stored in consideration of the relationship between the withstand voltage of the film and the capacity. Of course, only one type of valve metal is stored. You may let them.

(Appendix 1)
An electrolytic capacitor having an anode foil made of a metal having a valve action, a cathode layer, and an electrolyte layer interposed between the anode foil and the cathode layer,
Having a dielectric oxide film layer formed by depositing particles having a dielectric constant on the surface of the anode foil;
An electrolytic capacitor characterized by that.

(Appendix 2)
In Appendix 1,
The electrolytic capacitor, wherein the dielectric oxide film layer formed by depositing particles having a dielectric constant is formed by using an aerosol deposition method.

(Appendix 3)
In Appendix 1 or 2,
The anode foil is a flat rolled aluminum foil or an aluminum foil having an etched rough surface,
The electrolytic capacitor characterized in that the particles having the dielectric constant of the deposited layer deposited on the anode foil are valve metal particles mainly composed of a valve metal.

(Appendix 4)
In Appendix 3,
Furthermore, the particle | grains which have the said dielectric constant of the deposition layer deposited on the said anode foil contain the ceramic particle | grains which have a ceramic as a main component.

(Appendix 5)
In Appendix 4,
The ceramic particles are made of an oxide, nitride, or carbide having a dielectric constant of 10 or more.

(Appendix 6)
In Appendix 3,
The electrolytic capacitor includes at least one of valve metal aluminum and a compound thereof, titanium and a compound thereof, tantalum and a compound thereof, niobium and a compound thereof.

(Appendix 7)
In Appendix 3 or 4,
An electrolytic capacitor, wherein a metal oxide layer is formed by subjecting the anode foil and the deposited layer to a chemical conversion treatment.

(Appendix 8)
In Appendix 1 or 2,
An electrolytic capacitor comprising an electrolyte solution in which an organic acid salt or an inorganic acid salt is dissolved in a protonic solvent as an electrolyte of the electrolyte layer.

(Appendix 9)
In Appendix 1 or 2,
An electrolytic capacitor characterized in that at least one of a polythiophene-based, polypyrrole-based, polyaniline-based conductive polymer, and a TCNQ complex salt solid electrolyte is used as the electrolyte of the electrolyte layer.

(Appendix 10)
In Appendix 1 or 2,
An electrolytic capacitor characterized in that the cathode layer contains at least one of electrolytic paper, carbon, metal foil, metal particles, and conductive resin.

(Appendix 11)
In Appendix 3,
3. The electrolytic capacitor according to claim 2, wherein a particle diameter of the valve metal particles is in a range of 100 nm to 100 μm.
In Appendix 4,
The ceramic capacitor has a particle size of 500 nm or less.

  In the electrolytic capacitor according to the present invention, since the anode foil has a high capacity while maintaining strength, the winding electrolytic capacitor does not break at the connection to the anode and cathode electrode metal, and the laminated electrolytic Capacitors can also have higher capacities without causing foil damage during lamination. Therefore, the present invention greatly contributes to the industry.

It is the schematic which shows the structure of the winding type electrolytic capacitor as one Example to which this invention is applied. It is the schematic which shows the cross-section of the wound capacitor | condenser element in FIG. It is a figure which shows the procedure of the formation method of the 1st Example of the dielectric oxide film layer formed in the anode foil surface. It is a figure which shows the schematic structural example of an aerosol deposition chamber. It is a figure explaining the etched aluminum foil which has the rough surface by which the etching process was carried out previously. It is a figure which shows typically the layer which deposited the aluminum microparticles by aerosol deposition. It is a flowchart which shows the procedure of the manufacturing method of the electrode foil of the 2nd Example according to this invention. It is a flowchart which shows the procedure of the manufacturing method of the electrode foil of the 3rd Example according to this invention. It is a flowchart which shows the procedure of the manufacturing method of the electrode foil of the 4th Example according to this invention. It is a figure explaining the 4th Example of a dielectric oxide film layer. It is a figure explaining the ceramic (barium titanate) -aluminum film | membrane formed on the rough surface of the board | substrate aluminum foil by aerosol deposition. It is a figure explaining the etching process of the ceramic (barium titanate) -aluminum film | membrane of FIG. 9A. It is a figure which shows schematic structure inside the cross section of a 2 terminal type unit capacitor | condenser element. It is sectional drawing of the electrolytic capacitor which laminated | stacked the unit capacitor | condenser element of FIG. 10A. It is a figure which shows schematic structure inside the cross section of a 3 terminal type | mold unit capacitor element. It is sectional drawing of the electrolytic capacitor which laminated | stacked the unit capacitor | condenser element of FIG. 11A.

Explanation of symbols

21 Anode foil 22 Cathode foil 30 Electrolytic paper 31 Electrolyte 200 Dielectric oxide layer

Claims (5)

An electrolytic capacitor having an anode foil made of a metal having a valve action, a cathode layer, and an electrolyte layer interposed between the anode foil and the cathode layer,
Having a dielectric oxide film layer formed by depositing particles having a dielectric constant on the surface of the anode foil by an aerosol deposition method (excluding deposition in an atmosphere containing oxygen) ;
The electrolytic capacitor characterized in that the dielectric oxide film layer has a fine cavity layer formed by an etching process. Oite to claim 1,
The anode foil is a flat rolled aluminum foil or an aluminum foil having an etched rough surface,
The electrolytic capacitor characterized in that the particles having the dielectric constant of the deposited layer deposited on the anode foil are valve metal particles mainly composed of a valve metal. Oite to claim 2,
Furthermore, the particle | grains which have the said dielectric constant of the deposition layer deposited on the said anode foil contain the ceramic particle | grains which have a ceramic as a main component. Oite to claim 2,
The electrolytic capacitor includes at least one of valve metal aluminum and a compound thereof, titanium and a compound thereof, tantalum and a compound thereof, niobium and a compound thereof. Oite to claim 2 or 3,
An electrolytic capacitor, wherein a metal oxide layer is formed by subjecting the anode foil and the deposited layer to a chemical conversion treatment.

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