JP6913875B2 - Electrolytic capacitor - Google Patents

Description

The present invention relates to an electrolytic capacitor, and more particularly to an electrolytic capacitor in which an anode wire and an anode lead frame are welded together.

Electrolytic capacitors are installed in various electronic devices because they have a small equivalent series resistance (ESR) and excellent frequency characteristics. Electrolytic capacitors usually include a capacitor element having an anode part and a cathode part, an anode lead terminal electrically connected to the anode part, a cathode lead terminal electrically connected to the cathode part, a part of the anode lead terminal, and the like. It has an exterior body that covers a capacitor element so that a part of the cathode lead terminal is exposed to the outside. At the exposed portions of the anode lead terminal and the cathode lead terminal, the electrolytic capacitor is connected to the substrate of the electronic device. The anode portion has an anode body and an anode wire extending from the anode body. The anode wire is planted from approximately the center of one surface of the anode body. At this time, when an anode lead terminal having a plate-shaped member called an anode lead frame is used and the anode lead frame and the anode wire are joined to electrically connect the anode lead terminal and the anode wire. (Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-187896

In Patent Document 1, a notch is provided in the anode lead frame, the anode wire is fitted into the notch, and then the lower part of the anode wire and the anode lead frame are welded to each other. In this case, if the method of melting the anode lead frame and joining the anode wires, the positional deviation (depression) of the anode wires in the vertical direction (vertical direction) becomes large. This is because the anode lead frame is deformed by melting. In particular, in the case of resistance welding, since energization is performed while pressurizing, the deformation of the anode lead frame is likely to be large, and the drop of the anode wire is also large.

When the anode wire falls, the capacitor element tilts with the side on which the anode wire is planted facing down. Usually, the anode lead frame and the anode wire are joined in a state where the cathode lead terminal is brought into contact with the cathode portion via a conductive adhesive. Therefore, as the capacitor element is tilted, the cathode lead terminal and the capacitor element are separated from each other, or the conductive adhesive material interposed between them moves, resulting in unstable adhesiveness. This may reduce the connection reliability. Further, if the conductive adhesive protrudes between the cathode lead terminal and the capacitor element, the device may be contaminated.

The first aspect of the present invention is a capacitor element including an anode portion and a cathode portion, an anode lead terminal electrically connected to the anode portion, a cathode lead terminal electrically connected to the cathode portion, and the capacitor. An exterior body that covers the element and exposes at least a part of the anode lead terminal and the cathode lead terminal is provided, and the anode portion includes an anode body and an anode wire extending from the anode body. The anode lead terminal has an anode lead frame that is flat and has a notch formed by cutting out a part of the first side thereof, and is the main part of the anode lead frame. The anode portion and the anode lead terminal are formed by melting the end surface of the notch of the anode lead frame and welding it to the anode wire in a state where the surface and the stretching direction of the anode wire are crossed. A first that is electrically connected and has an end face of the notch extending from one of the first notched ends of the first side toward a second side facing the first side. It is formed by a side portion and a second side portion extending from the other second notched end portion of the first side toward the second side, and is formed by the anode wire and the anode lead frame. Is welded at the first side portion and the second side portion, and in a state where the second side is in contact with the horizontal plane, the anode is from the normal direction of the main surface of the anode lead frame. When looking at the cross section of the wire, the straight line Lc drawn in the horizontal direction passing through the center C of the cross section of the anode wire is the straight line Lw _{1 connecting the first welding mark on the first side portion and the center C.} acute .theta.w 1 _forming, and the straight line Lc is acute .theta.w ₂ formed by the straight line Lw ₂ connecting the second welding marks on the second side portion and said center C, both greater than 0 °, 45 ° or less Regarding electrolytic capacitors.

According to the present invention, since the drop of the anode wire during welding is suppressed, a high quality electrolytic capacitor can be stably obtained.

It is sectional drawing of the electrolytic capacitor which concerns on one Embodiment of this invention. It is a front schematic view (a) which saw the anode lead frame from the normal direction of the main surface, and the sectional schematic view (b) which saw the anode lead frame and the anode wire after welding from the same direction. It is sectional drawing which shows the anode lead frame which concerns on one Embodiment of this invention, and the anode wire welded to this. It is sectional drawing which shows the anode lead frame which concerns on other embodiment of this invention, and the anode wire welded to this. It is sectional drawing which shows the anode lead frame which concerns on still another Embodiment of this invention, and the anode wire welded to this. FIG. 3A is a schematic cross-sectional view showing an anode lead frame and an anode wire before welding according to an embodiment of the present invention, and FIG. 6B is a schematic cross-sectional view showing an anode lead frame and an anode wire (a) after welding.

The electrolytic capacitor according to the embodiment of the present invention will be described with reference to FIG. 1 by taking as an example a case where a solid electrolyte layer is provided as an electrolyte, but the present invention is not limited thereto. FIG. 1 is a schematic cross-sectional view of the electrolytic capacitor 20 according to the present embodiment.

<Electrolytic capacitor>
The electrolytic capacitor 20 is electrically connected to the capacitor element 10 having the anode portion 6 and the cathode portion 7, the exterior body 11 that seals the capacitor element 10, and the anode portion 6, and is partially connected to the exterior body 11. It includes an exposed anode lead terminal 13 and a cathode lead terminal 14 that is electrically connected to the cathode portion 7 and is partially exposed from the exterior body 11. The anode portion 6 has an anode body 1 having a dielectric layer 3 and an anode wire 2. The cathode portion 7 has a solid electrolyte layer 4 formed on the dielectric layer 3 and a cathode layer 5 covering the surface of the solid electrolyte layer 4.

<Anode part>
The anode portion 6 has an anode body 1 and an anode wire 2 extending from one surface of the anode body 1 and electrically connected to the anode lead terminal 13.
The anode body 1 is, for example, a rectangular parallelepiped porous sintered body obtained by sintering metal particles. As the metal particles, particles of a valve acting metal such as titanium (Ti), tantalum (Ta), and niobium (Nb) are used. One kind or two or more kinds of metal particles are used for the anode body 1. The metal particles may be an alloy composed of two or more kinds of metals. For example, an alloy containing a valve acting metal and silicon, vanadium, boron or the like can be used. Further, a compound containing a valve acting metal and a typical element such as nitrogen may be used. The valve-acting metal alloy preferably contains the valve-acting metal as a main component and contains 50 atomic% or more of the valve-acting metal.

The anode wire 2 is made of, for example, a conductive material. The material of the anode wire 2 is not particularly limited, and examples thereof include copper, aluminum, and aluminum alloys in addition to the valve acting metal. The material of the anode wire 2 is selected so that the anode lead frame 131 melts during welding in consideration of the material of the anode lead terminal 13 (anode lead frame 131 described later) and the welding method. The anode wire 2 has a first portion 2a embedded in the anode body 1 from one surface of the anode body 1 and a second portion 2b extending from the one surface of the anode body 1. The cross-sectional shape of the anode wire 2 is not particularly limited, and is a circle or a shape like a crushed circle (a shape consisting of straight lines parallel to each other and two curves connecting the ends of these straight lines. Hereinafter, it is referred to as a track shape. ), Oval, rectangular, polygonal, etc. Of these, the track type is preferable because rolling is suppressed during welding with the anode lead frame 131 and positioning is easy. The diameter of the anode wire 2 (major diameter in the case of a track type and an elliptical shape) is also not particularly limited, but is, for example, 0.1 mm to 1.0 mm.

The anode portion 6 is manufactured, for example, by embedding the first portion 2a in the powder of the metal particles, pressure-molding the metal particles into a rectangular parallelepiped shape, and sintering the metal particles. 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 planted. The second portion 2b is joined to the anode lead frame 131 by welding (resistance welding, laser welding, etc.). As a result, the anode wire 2 and the anode lead terminal 13 are electrically connected. The welding method is not particularly limited, but here, the method of welding by melting the anode lead frame 131 is selected in consideration of both materials. For example, when the anode wire 2 is tantalum and the anode lead frame 131 is copper, if resistance welding is adopted, the anode lead frame 131 melts.

A dielectric layer 3 is formed on the surface of the anode body 1. The dielectric layer 3 is made of, for example, a metal oxide. As a method of forming a layer containing a metal oxide on the surface of the anode body 1, for example, a method of immersing the anode body 1 in a chemical conversion liquid to anodize the surface of the anode body 1 or a method of anodizing the surface of the anode body 1 containing oxygen. A method of heating in an atmosphere can be mentioned. The dielectric layer 3 is not limited to the layer containing the metal oxide, and may have an insulating property.

<Cathode>
The cathode portion 7 has a solid electrolyte layer 4 formed on the dielectric layer 3 and a cathode layer 5 covering the solid electrolyte layer 4.
The solid electrolyte layer 4 may be formed so as to cover at least a part of the dielectric layer 3. For the solid electrolyte layer 4, for example, a manganese compound or a conductive polymer is used. Examples of the conductive polymer include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyparaphenylene vinylene, polyacene, polythiophene vinylene, polyfluorene, polyvinylcarbazole, polyvinylphenol, polypyridine, and derivatives of these polymers. Can be mentioned. These may be used alone or in combination of a plurality of types. Further, the conductive polymer may be a copolymer of two or more kinds of monomers. Among these, polythiophene, polyaniline, polypyrrole and the like are preferable in terms of excellent conductivity. Of these, polypyrrole is preferable because it has excellent water repellency.

The solid electrolyte layer 4 containing the conductive polymer is formed, for example, by polymerizing a raw material monomer on the dielectric layer 3. Alternatively, it is formed by applying a liquid containing the conductive polymer to the dielectric layer 3. The solid electrolyte layer 4 is composed of one layer or two or more solid electrolyte layers. When the solid electrolyte layer 4 is composed of two or more layers, the composition and the forming method (polymerization method) of the conductive polymer used for each layer may be different.

In addition, in this specification, polypyrrole, polythiophene, polyfuran, polyaniline and the like mean a polymer having polypyrrole, polythiophene, polyfuran, polyaniline and the like as a basic skeleton, respectively. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline and the like may also contain their respective derivatives. For example, polythiophene includes poly (3,4-ethylenedioxythiophene) and the like.

Various dopants may be added to the polymerization solution for forming the conductive polymer, the solution or the dispersion liquid of the conductive polymer, in order to improve the conductivity of the conductive polymer. The dopant is not particularly limited, but 1,5-naphthalenedisulfonic acid, 1,6-naphthalenedisulfonic acid, 1-octanesulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 2,6-naphthalenedisulfonic acid, 2,7-naphthalenedisulfonic acid, 2-methyl-5-isopropylbenzenesulfonic acid, 4-octylbenzenesulfonic acid, 4-nitrotoluene-2-sulfonic acid, m-nitrobenzenesulfonic acid, n-octylsulfonic acid, n-butane Sulfonic acid, n-hexanesulfonic acid, o-nitrobenzenesulfonic acid, p-ethylbenzenesulfonic acid, trifluoromethanesulfonic acid, hydroxybenzenesulfonic acid, butylnaphthalenesulfonic acid, benzenesulfonic acid, polystyrenesulfonic acid, polyvinylsulfonic acid, methane Examples thereof include sulfonic acids and derivatives thereof. Examples of the derivative include metal salts such as lithium salt, potassium salt and sodium salt, ammonium salts such as methylammonium salt, dimethylammonium salt and trimethylammonium salt, piperidium salt, pyrrolidium salt and pyrrolinium salt.

When the conductive polymer is dispersed in a dispersion medium in the form of particles, the average particle size D50 of the particles is preferably, for example, 0.01 μm to 0.5 μm. When the average particle size D50 of the particles is in this range, the particles easily penetrate into the inside of the anode 1.

The cathode layer 5 has, for example, a carbon layer 5a formed so as 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 a resin. The configuration of the cathode layer 5 is not limited to this configuration. The structure of the cathode layer 5 may be any structure having a current collecting function.

<Anode lead terminal>
The anode lead terminal 13 has a function of electrically connecting the electronic component on which the electrolytic capacitor 20 is mounted and the anode portion 6. The anode lead terminal 13 includes a flat plate-shaped anode lead frame 131 and an anode exposed portion 132 exposed from the exterior body 11. The anode lead frame 131 and the anode exposed portion 132 may be integrally formed or may be separate bodies. If they are separate, they are electrically connected. The anode lead frame 131 is sealed by the exterior body 11 together with the capacitor element 10.

Hereinafter, the anode lead frame 131 will be described in detail with reference to FIGS. 2 (a) and 2 (b). FIG. 2A is a schematic front view of the anode lead frame 131 as viewed from the normal direction of its main surface, and FIG. 2B shows the welded anode lead frame 131 and the anode wire 2 in the same direction. It is a schematic cross-sectional view seen from the perspective. FIG. 2B shows the anode wire 2 by its cross section, but hatching is omitted for convenience. The same applies to FIGS. 3A to 3C and FIG. In the illustrated example, the anode lead frame 131 is erected with the second side 1312 in contact with the horizontal plane. Hereinafter, the vertical direction or the horizontal direction refers to the direction when the anode lead frame 131 is viewed in an upright state as shown in the illustrated example.

The anode lead frame 131 is formed with a notch N that cuts out a part of the first side 1311. Such an anode lead frame 131 can be obtained, for example, by punching a plate-shaped conductor (conductor plate) into a predetermined shape. At the time of welding, the second portion 2b of the anode wire 2 is placed in the notch N.

In the present embodiment, the anode lead frame 131 and the anode wire 2 are arranged so that the main surface of the anode lead frame 131 and the stretching direction of the anode wire 2 intersect, and the anode lead frame 131 is melted. The anode lead terminal 13 and the anode wire 2 are joined. However, in order to bring the anode wire 2 into contact with both side portions NS1, NS2 of the end face of the notch N or the two corner portions formed by the notch N, and to weld while supporting both sides of the anode wire 2. , The positional deviation (depression) of the anode wire 2 in the vertical direction becomes small. Further, since the anode lead frame 131 and the anode wire 2 are brought into contact with each other at two points, the welding area per place required for connection is smaller than that in the case where only one place is brought into contact with each other for welding. Therefore, the amount of melting of the anode lead frame 131 per location is reduced, and the drop of the anode wire 2 is further suppressed.

Conventionally, an anode wire having a circular cross section has a small contact area with the anode lead frame, so that it is necessary to increase the amount of melting of the anode lead frame. Therefore, when a circular anode wire is used, the amount of depression tends to be generally large. However, according to the present embodiment, the amount of depression is suppressed even when a circular anode wire is used.

The notch N cuts out a part of the first side 1311. The end face of the notch N extends from the start point of the notch formed on the first side 1311 (first notch end 1311A) toward the second side 1312 facing the first side 1311. It is formed by one side portion NS1 and a second side portion NS2 extending from the end point of the notch formed on the first side 1311 (second notch end portion 1311B) toward the second side 1312. ing. In the illustrated example, the end face of the notch N is further an end different from the first notch end 1311A of the first side portion NS1 and an end different from the second notch end 1311B of the second side portion NS2. A bottom portion NB that connects the portion and the portion is provided.

The shape of the notch N is not particularly limited as long as the anode wire 2 and the anode lead frame 131 are welded at two points, the first side portion NS1 and the second side portion NS2. In particular, when the cross section of the anode wire 2 after welding is viewed from the normal direction of one main surface of the anode lead frame 131, a straight line Lc drawn in the horizontal direction passing through the center C of the cross section of the anode wire 2 is the first. 1 acute angle with the straight line Lw ₁ connecting the welding mark W1 and the center C of the side portion NS1 (hereinafter, referred to as the welding angle .theta.w _1), and a straight line Lc is the second welding marks on the second side portion NS2 W2 _{The acute angle formed by the straight line Lw 2} connecting the center C and the center C (hereinafter referred to as the welding angle θw ₂ ) is formed so as to be larger than 0 ° and 45 ° or less. As a result, the dip of the anode wire 2 is reduced. It is more preferable that the welding angle θw ₁ and the welding angle θw ₂ are 15 ° or more and 30 ° or less. The straight line Lw ₁ and the straight line Lw ₂ are straight lines formed by connecting the center of each welding mark and the center C of the anode wire 2.

In such a notch N, for example, the length of a straight line Ln connecting the first notch end portion 1311A and the second notch end portion 1311B before welding (hereinafter, referred to as a notch width Dn) is an anode. The shape is shorter than the maximum length of the wire 2 in the direction along the straight line Ln (hereinafter, _{referred to as the first diameter D2 H).} As a result, the anode wire 2 is welded to the anode lead frame 131 at two points, the first side portion NS1 and the second side portion NS2, instead of the bottom portion NB of the notch N. Therefore, at the time of welding, the anode wire 2 does not fall to the second side 1312 side from the bottom portion NB, so that the amount of the anode wire 2 falling is further suppressed. The ratio of the notch width Dn to the first diameter D2 _{H : (Dn / D2 H} ) × 100% is preferably 50 to 90%, more preferably 60 to 80%.

The notch N preferably has a tapered shape that narrows toward the second side 1312. That is, it is preferable that the distance between the first side portion NS1 and the second side portion NS2 decreases toward the second side 1312. This is because the depression of the anode wire 2 is more likely to be suppressed. Among them, the acute angle formed by the vertical direction and the first side portion NS1 (hereinafter _{referred to as the first taper angle θt 1} ) and the acute angle formed by the vertical direction and the second side portion NS2 (hereinafter referred to as the second taper angle). θt ₂ ) is larger than 0 °, preferably 60 ° or less, and more preferably 45 ° or less. The first taper angle θt ₁ may be calculated by measuring the angle formed by the bottom portion NB and the first side portion NS1 and subtracting 90 ° from this angle. The same applies to the second taper angle θt _2.

In the illustrated example, the end face of the notch N includes a bottom portion NB, but is not limited thereto. The first side portion NS1 and the second side portion NS2 may intersect to form a V shape. Further, the bottom portion NB in the illustrated example is linear, but the present invention is not limited to this. The bottom portion NB may have a curved portion. In order to control the amount of depression of the anode wire 2 due to welding, the bottom portion NB may be provided with protrusions or steps that can support the anode wire 2 after welding. When the bottom portion NB has a linear or curved portion, the width of the bottom portion NB is not particularly limited and may be appropriately set in consideration _{of the first diameter D2 H of the anode wire 2 and the welding position.}

The welding position can be adjusted by the above Dn / D2 _H , the first taper angle θt ₁ , and the second taper angle θt _2. An example is shown in FIGS. 3A to 3C. In FIGS. 3A to 3C, the diameters D2 _H of the anode wire 2 are the same. 3A to 3C are schematic cross-sectional views showing an anode lead frame and an anode wire welded to the anode lead frame according to the present embodiment, respectively.

The notch width Dn of the anode lead frame 131A of FIG. 3A and the anode lead frame 131B of FIG. 3B is the same. On the other hand, the first taper angle θt _1B and the second taper angle θt _2B of the anode lead frame 131B are larger than _{the first taper angle θt 1A} and the second taper angle θt _2A of the anode lead frame 131A. Therefore, in the case of FIG. 3B, the positions of the first welding mark W1 _B and the second welding mark W2 _B are shifted to the bottom portion NB side from the first welding mark W1 _A and the second welding mark W2 _{A in FIG. 3A.} .. In other words, the welding angle θw ₁ and the welding angle θw ₂ in FIG. 3B are larger.

_{The first taper angle θt 1} and the second taper angle θt ₂ of the anode lead frame 131A of FIG. 3A and the anode lead frame 131C of FIG. 3C are the same. On the other hand, the notch width Dn _C of the anode lead frame 131C is smaller than _{the notch width Dn A} of the anode lead frame 131A. That is, Dn / D2 _H in FIG. 3C is smaller. Again, the position of the first welding mark W1 _C and the second welding mark W2 _C in FIG. 3C is shifted to the bottom portion NB side of FIG. 3A, the welding angle .theta.w ₁ and the welding angle .theta.w ₂ in Figure 3C , Larger.

In the illustrated example, the anode wire 2 after welding and the bottom portion NB of the notch N are in contact with each other, but the present invention is not limited to this, and the anode wire 2 and the bottom portion NB may not be in contact with each other. This is because the anode wire 2 after welding is joined and supported by the two side portions NS1 and NS2. However, it is preferable that the anode wire 2 and the bottom portion NB are in contact with each other after welding because it is easy to control the amount of depression of the anode wire 2 due to welding.

The depth of the notch N is not particularly limited. When the anode wire 2 and the bottom portion NB are brought into contact with each other after welding, the depth Dnd of the notch N (see FIG. 2A) is the diameter of the anode wire 2 in the vertical direction (second diameter D2 _V ). It is preferably 50% or less of. As a result, the amount of depression of the anode wire 2 is reduced, and it becomes easier to control the position of the anode wire 2 after welding. In this case, the center C of the anode wire 2 after welding is located on the side opposite to the second side 1312 with respect to the straight line Ln. _{The first diameter D2 H} of the anode wire 2 is preferably larger than the second diameter D2 _{V in} terms of easy positioning and suppression of rolling of the anode wire 2.

The depth Dnd of the notch N is the length of a straight line drawn in the vertical direction from the center of the straight line Ln to the bottom portion NB. The second diameter D2 _V of the anode wire 2 is vertical from the center C to the outer edge of the anode wire 2 when the cross section of the anode wire 2 after welding is viewed from the normal direction of one main surface of the anode lead frame 131. The length of the straight line drawn in the direction.

<Cathode lead terminal>
The cathode lead terminal 14 is electrically connected to the cathode portion 7. The cathode lead terminal 14 is not particularly limited as long as it is made of a conductive material (conductor). The shape is not particularly limited, and is, for example, a flat plate. The thickness of the cathode lead terminal 14 is, for example, 25 to 100 μm. The cathode lead terminal 14 may be electrically connected to the cathode portion 7 via a conductive adhesive (not shown).

<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. The exterior body 11 contains, for example, a cured product of a thermosetting resin. Examples of the thermosetting resin include epoxy resin, phenol resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, unsaturated polyester and the like.

The exterior body 11 is formed by, for example, housing the thermosetting resin and the capacitor element 10 to which the anode lead terminal 13 and the cathode lead terminal 14 are connected in a mold and performing a transfer molding method, a compression molding method, or the like. NS. At this time, the capacitor element 10 is covered with the exterior body 11 so that the anode lead terminal 13 and the cathode lead terminal 14 each have an exposed portion exposed from the exterior body 11. The outer shape of the exterior body 11 is, for example, a rectangular parallelepiped. The exposed portion of the anode lead terminal 13 and the exposed portion of the cathode lead terminal 14 are arranged on the same surface of the rectangular parallelepiped exterior body 11.

An example of a method for manufacturing an electrolytic capacitor according to the present embodiment will be described.
≪Manufacturing method of electrolytic capacitors≫
(1) Step of manufacturing the anode part 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 in vacuum. As a result, an anode portion 6 in which the first portion 2a is embedded from one surface of the porous sintered body is produced. The pressure during pressure molding is not particularly limited, and is, for example, about 10 to 100 N. If necessary, a binder such as polyacrylic carbonate may be mixed with the valve acting metal particles.

(2) Step of Forming a Dielectric Layer on the Anode Body The dielectric layer 3 is formed on the anode body 1. Specifically, the anode 1 is immersed in a chemical bath filled with an electrolytic aqueous solution (for example, a phosphoric acid aqueous solution), and the second portion 2b of the anode wire 2 is connected to the anode body of the chemical tank for anodizing. By performing the above, a dielectric layer 3 made of an oxide film of a valve acting metal can be formed on the surface of the anode body 1. The electrolytic aqueous solution is not limited to the phosphoric acid aqueous solution, and nitric acid, acetic acid, sulfuric acid and the like can be used.

(3) Forming Step of Solid Electrolyte Layer In the present embodiment, a step of forming the solid electrolyte layer 4 containing the conductive polymer will be described.
The solid electrolyte layer 4 containing the conductive polymer is prepared, for example, by impregnating the anode 1 on which the dielectric layer 3 is formed with a monomer or an oligomer, and then polymerizing the monomer or the oligomer by chemical polymerization or electrolytic polymerization. Alternatively, the anode 1 on which the dielectric layer 3 is formed is impregnated with a solution or dispersion of a conductive polymer and dried to form at least a part of the dielectric layer 3.

(4) Forming Step of Cathode Layer By sequentially applying carbon paste and metal paste to the surface of the solid electrolyte layer 4, the cathode layer 5 composed of the carbon layer 5a and the metal paste layer 5b can be formed. can. The configuration of the cathode layer 5 is not limited to this, and may be any configuration having a current collecting function.

(5) Step of connecting the anode lead terminal to the anode body The anode wire 2 and the anode lead frame 131 are joined by laser welding or resistance welding.
First, the second portion 2b of the anode wire 2 is placed in the notch N of the anode lead frame 131. When the anode wire 2 has an elliptical shape, the anode wire 2 is placed in the notch N of the anode lead frame 131 so that the major axis direction thereof is along the straight line Ln. In this case, the major axis and the diameter D2 _H of the anode wire 2 can be the same.

When the notch width Dn of the notch N _{is smaller than the first diameter D2 H} of the anode wire 2, as shown in FIG. 4A, the anode wire 2 has two corners (the second) of the notch N. It is supported by one notched end 1311A and a second notched end 1311B). When the anode wire 2 and the bottom portion NB are brought into contact with each other after welding, a minute clearance C (for example, 0. 01 mm) is preferably provided. On the other hand, when the notch width Dn of the notch N _{is equal to or larger than the diameter D2 H} of the anode wire 2, for example, the first taper angle θt ₁ and the second taper angle θt ₂ are appropriately set, and the first side portion NS1 and the first side portion NS1 and The two points of the second side portion NS2 and the anode wire 2 are brought into contact with each other.

In either case, the anode wire 2 mounted on the anode lead frame 131 is supported at two points on the anode lead frame 131, so that the anode wire 2 is prevented from rolling. Further, even when the anode wire 2 is placed in the notch N at a position deviated from a predetermined position, the anode wire 2 is guided by the two side portions NS of the notch N and fits in the predetermined position. .. Therefore, the anode wire 2 can be placed at a predetermined position of the notch N without applying a load.

Next, the anode lead frame 131 is melted and the anode wire 2 is welded. At this time, the method of melting the anode lead frame 131 is selected in consideration of the materials of the anode lead frame 131 and the anode wire 2.

(6) Step of Connecting Cathode Lead Terminal to Cathode Layer After applying a conductive adhesive to the cathode layer 5, the cathode lead terminal 14 is joined to the cathode layer 5 via the conductive adhesive. When the step (5) and the step (6) are performed at the same timing, that is, the capacitor element 10 coated with the conductive adhesive is placed on the anode lead terminal 13 and the cathode lead terminal 14 arranged on the work table. Even when the anode lead frame 131 and the anode wire 2 are welded after placement, the adhesiveness between the cathode lead terminal 14 and the cathode layer 5 is stabilized. This is because the depression of the anode wire 2 is suppressed and the inclination of the capacitor element 10 is suppressed. Further, the protrusion of the conductive adhesive is suppressed, so that the contamination of the device is reduced.

(7) Step of Sealing the Capacitor Element Next, the materials of the capacitor element 10 and the exterior body 11 (for example, uncured thermosetting resin and filler) are housed in a mold and subjected to a transfer molding method, a compression molding method, or the like. , The capacitor element 10 is sealed with the exterior body 11. At this time, a part of the anode lead terminal 13 and the cathode lead terminal 14 is 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.
The electrolytic capacitor 20 is manufactured by the above method.

Since the electrolytic capacitor according to the present invention has excellent connection reliability, it can be used for various purposes.

20: Electrolytic capacitor 10: Capacitor element 1: Anode body 2: Anode wire 2a: First part of anode wire 2b: Second part of anode wire 3: Dielectric layer 4: Solid electrolyte layer 5: Cathode layer 5a: Carbon layer 5b : Metal paste layer 6: Anode part 7: Cathode part 11: Exterior body 13: Anode lead terminal 131, 131A to 131C: Anode lead frame 1311: First side
1311A: 1st notched end 1311B: 2nd notched end 1312: 2nd side N: Notch NS1: 1st side part NS2: 2nd side part NB: Bottom part 132: Anode exposed part 14: Cathode Lead terminal

Claims (4)

A capacitor element having an anode part and a cathode part,
An anode lead terminal that is electrically connected to the anode portion and
A cathode lead terminal that is electrically connected to the cathode portion and
An exterior body that covers the capacitor element and exposes at least a part of the anode lead terminal and the cathode lead terminal is provided.
The anode portion has an anode body and an anode wire extending from the anode body.
The anode lead terminal has an anode lead frame that is flat and has a notch that cuts out a part of the first side thereof.
With the main surface of the anode lead frame and the stretching direction of the anode wire intersecting, the end face of the notch of the anode lead frame is melted and welded to the anode wire to form the anode portion. The anode lead terminal is electrically connected and
The end face of the notch includes a first side portion extending from one first notch end of the first side toward a second side facing the first side, and the first side portion. It is formed by a second side portion extending from the other second notched end of the side toward the second side.
The anode wire and the anode lead frame are welded at the first side portion and the second side portion.
When the cross section of the anode wire is viewed from the normal direction of the main surface of the anode lead frame with the second side in contact with the horizontal plane,
An acute angle θw ₁ formed by a straight line Lc drawn in the horizontal direction passing through the center C of the cross section of the anode wire _{and forming a straight line Lw 1} connecting the first welding mark on the first side portion and the center C, and
The straight line Lc is acute .theta.w ₂ formed by the straight line Lw ₂ connecting the second welding marks on the second side portion and said center C, both greater than 0 °, Ri der 45 ° or less,
The end face of the notch further includes an end portion of the first side portion different from the first notch end portion and an end portion of the second side portion different from the second notch end portion. Equipped with a bottom to connect
An electrolytic capacitor in which the anode wire is in contact with the bottom portion without being welded to the bottom portion. When looking at the cross section of the anode wire,
The first aspect of the present invention, wherein the center C is located on the side opposite to the second side with respect to the straight line Ln connecting the first notched end portion and the second notched end portion of the notch. The electrolytic capacitor described. The distance between the first side portion and the second side portion becomes smaller toward the second side.
When looking at the cross section of the anode wire,
Claim 1 or claim 1, wherein the acute angle θt ₁ formed by the vertical direction and the first side portion and the acute angle θt ₂ formed by the vertical direction and the second side portion are both larger than 0 ° and 60 ° or less. 2. The electrolytic capacitor according to 2. The electrolytic capacitor according to any one of claims 1 to 3, wherein the cross section of the anode wire has a shape in which a first diameter along the straight line Ln is larger than a second diameter orthogonal to the straight line Ln.

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