JPWO2018159426A1 - Electrolytic capacitor - Google Patents

Abstract

An electrolytic capacitor including a capacitor element having an anode portion and a cathode portion, an anode wire, and an anode lead terminal having a first main surface and a second main surface, wherein the anode lead terminal is inside the exterior body. An inner bent portion and an outer bent portion outside the exterior body are provided, and the inner bent portion moves the anode lead terminal extending from the joint portion with the anode wire to the first main surface at a position not in contact with the anode wire. A first internal bending portion to be bent, and a second internal bending portion for bending the anode lead terminal bent at the first internal bending portion in a direction along the anode wire and leading the anode lead terminal out of the exterior body, wherein the external bending portion includes: A first outer bent portion that bends the anode lead terminal derived from the outer package toward the first main surface side, and an anode lead terminal bent at the first outer bent portion is bent along the outer shape of the outer package; The second outside placed on the mounting surface Part bending part.

Description

   The present invention relates to an electrolytic capacitor, and more particularly, to an electrolytic capacitor having a bent anode lead terminal.

   Electrolytic capacitors have low equivalent series resistance (ESR) and excellent frequency characteristics, and are therefore mounted on various electronic devices. An electrolytic capacitor generally includes a capacitor element having an anode section and a cathode section, an anode lead terminal electrically connected to the anode section, and a cathode lead terminal electrically connected to the cathode section. The anode section has an anode body and an anode wire extending from the anode body. The anode lead terminal is, for example, a long plate-shaped member, and an anode wire is bonded to one main surface. The capacitor element is usually sealed with an exterior body. The anode lead terminal is bent a plurality of times and is led out of the outer package, and then further bent along the outer shape of the outer package (Patent Document 1 and the like).

JP-A-10-64758

   As shown in FIG. 3, the anode lead terminal 113 of the electrolytic capacitor 120 of Patent Document 1 is bent in a substantially U-shape. The anode lead terminal 113 further includes a bent portion B that bends the inside of the exterior body 111 in a direction to separate the anode lead terminal 113 from the anode wire 102. Here, when the anode lead terminal 113 led out of the exterior body 111 is bent along the outer shape of the exterior body 111, the anode lead terminal 113 inside the exterior body 111 is connected to the anode lead terminal 113 from the anode wire 102. Stress F in the direction of peeling acts. At this time, the presence of the bent portion B makes it easier for the anode lead terminal 113 to be separated from the anode wire 102. Alternatively, when the anode lead terminal 113 is moved by the stress F, the position of the anode wire 102 is easily shifted. When the anode wire 102 is displaced, peeling may occur at the boundary between the anode body constituting the capacitor element 110 and the anode wire 102. Therefore, the leakage current tends to increase.

   A first aspect of the present invention is a capacitor element including an anode part and a cathode part, an anode lead terminal electrically connected to the anode part and having a first main surface and a second main surface, and the cathode part. An electrolytic capacitor comprising: a cathode lead terminal to be electrically connected; and an exterior body that covers the capacitor element and exposes at least a part of each of the anode lead terminal and the cathode lead terminal. Has an anode body and an anode wire extending from the anode body and joined to the first main surface of the anode lead terminal, wherein the anode lead terminal has an internal bent portion inside the exterior body. And an external bent portion outside the exterior body, wherein the internal bent portion extends the anode lead terminal extending from a joint portion with the anode wire, at a position not in contact with the anode wire. A first internal bent portion bent to the main surface side, and a second internal bent portion for bending the anode lead terminal bent at the first internal bent portion in a direction along the anode wire and leading out from the exterior body. A first external bent portion, wherein the external bent portion bends the anode lead terminal derived from the exterior body toward the first main surface side, and the anode lead bent at the first external bent portion. A second external bent portion that bends a terminal along the outer shape of the outer package and arranges the terminal on a mounting surface of the outer package.

   According to the present invention, since the anode lead terminal can be bent outside the exterior body without applying a load to the anode wire, displacement of the anode wire and peeling from the anode lead terminal are suppressed. Therefore, the leakage current decreases.

It is a cross section of an electrolytic capacitor concerning one embodiment of the present invention. FIG. 1 is an enlarged schematic cross-sectional view showing a main part of an electrolytic capacitor according to an embodiment of the present invention. It is a cross section showing some conventional electrolytic capacitors.

<Electrolytic capacitor>
An electrolytic capacitor according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 by taking a case where a solid electrolyte layer is provided as an electrolyte as an example, but the present invention is not limited to this. FIG. 1 is a schematic cross-sectional view of an electrolytic capacitor 20 according to the present embodiment. FIG. 2 is an enlarged schematic cross-sectional view showing a main part of the electrolytic capacitor 20 according to one embodiment of the present invention.

   The electrolytic capacitor 20 is electrically connected to the capacitor element 10 having the anode part 6 and the cathode part 7, the exterior body 11 for sealing the capacitor element 10, and the anode part 6, and partially from the exterior body 11. An exposed anode lead terminal 13 and a cathode lead terminal 14 electrically connected to the cathode portion 7 and partially exposed from the exterior body 11 are provided. The anode section 6 has an anode body 1 having the dielectric layer 3 and an anode wire 2. Cathode section 7 has solid electrolyte layer 4 formed on dielectric layer 3 and cathode layer 5 covering the surface of solid electrolyte layer 4.

<Capacitor element>
The capacitor element 10 according to the present embodiment will be described in detail.

(Anode)
The anode section 6 has an anode body 1 and an anode wire 2 extending from one surface of the anode body 1 and electrically connected to an anode lead terminal 13.

   The anode body 1 is, for example, a rectangular parallelepiped porous sintered body obtained by sintering metal particles. Valve metal particles such as titanium (Ti), tantalum (Ta), and niobium (Nb) are used as the metal particles. One or more metal particles are used for anode body 1. The metal particles may be an alloy composed of two or more metals. For example, an alloy containing a valve metal and silicon, vanadium, boron, or the like can be used. Further, a compound containing a valve metal and a typical element such as nitrogen may be used. It is preferable that the alloy of the valve action metal contains the valve action metal as a main component and the valve action metal in an amount of 50 atomic% or more.

   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 copper, aluminum, an aluminum alloy, and the like, in addition to the valve action metal. The materials constituting anode body 1 and anode wire 2 may be the same or different. The anode wire 2 has a first portion 2 a embedded from one surface of the anode body 1 into the inside of the anode body 1, and a second portion 2 b extending from the one surface of the anode body 1. The cross-sectional shape of the anode wire 2 is not particularly limited, and may be a circular shape or a shape obtained by crushing a circular shape (a shape formed of straight lines parallel to each other and two curves connecting the ends of these straight lines; hereinafter, referred to as a track shape). .), An ellipse, a rectangle, a polygon, and the like. Among them, the track shape is preferable because rolling is suppressed during welding with the anode lead terminal 13 and positioning is easy. The diameter of the anode wire 2 (the long diameter in the case of the track shape and the elliptical shape) is also not particularly limited, but is, for example, 0.1 mm to 1.0 mm.

   The anode part 6 is produced, for example, by pressing and sintering the first part 2a into a rectangular parallelepiped shape with the first part 2a embedded in the powder of the metal particles. Thereby, 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, and the anode wire 2 and the anode lead terminal 13 are electrically connected. The welding method is not particularly limited, and examples include resistance welding and laser welding.

   On the surface of anode body 1, dielectric layer 3 is formed. 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 solution to anodize the surface of the anode body 1 or a method of forming the anode body 1 with oxygen And a method of heating under an atmosphere including the above. The dielectric layer 3 is not limited to the layer containing the metal oxide, and may have any insulating property.

(Cathode)
The cathode section 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 only needs to 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, polyparaphenylenevinylene, polyacene, polythiophenvinylene, polyfluorene, polyvinylcarbazole, polyvinylphenol, polypyridine, and derivatives of these polymers. No. These may be used alone or in combination of two or more. The conductive polymer may be a copolymer of two or more monomers. Among these, polythiophene, polyaniline, polypyrrole, and the like are preferable in terms of excellent conductivity. Among them, polypyrrole is preferred because of its 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 or more solid electrolyte layers. When the solid electrolyte layer 4 is composed of two or more layers, the composition and the formation method (polymerization method) of the conductive polymer used for each layer may be different.

   In this specification, polypyrrole, polythiophene, polyfuran, polyaniline, and the like mean polymers each having a basic skeleton of polypyrrole, polythiophene, polyfuran, polyaniline, or the like. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline, and the like may include their derivatives. For example, polythiophene includes poly (3,4-ethylenedioxythiophene) and the like.

   Various dopants may be added to the polymerization liquid for forming the conductive polymer, the solution or the dispersion 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, polyvinyl sulfo Acid, methanesulfonic acid, and, derivatives thereof, and the like. 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 pyrrolium salt.

   When the conductive polymer is dispersed in the dispersion medium in the form of particles, the average particle diameter D50 of the particles is preferably, for example, 0.01 μm to 0.5 μm. If the average particle diameter D50 of the particles is in this range, the particles can easily enter the inside of the anode body 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 includes, for example, metal particles (for example, silver) and a resin. The configuration of the cathode layer 5 is not limited to this configuration. The configuration of the cathode layer 5 may be a configuration having a current collecting function.

<Anode lead terminal>
The anode lead terminal 13 is electrically connected to the anode body 1 via the second portion 2b of the anode wire 2. The material of the anode lead terminal 13 is not particularly limited as long as it is electrochemically and chemically stable and has conductivity, and may be metal or nonmetal. The shape is not particularly limited as long as it is a long and flat plate having the first main surface 13X and the second main surface 13Y. The thickness of the anode lead terminal 13 (the distance between the main surfaces of the anode lead terminal 13) is preferably 25 μm to 200 μm, and more preferably 25 μm to 100 μm, from the viewpoint of reducing the height.

   The anode lead terminal 13 may be joined to the anode wire 2 by a conductive adhesive or solder, or may be joined to the anode wire 2 by resistance welding or laser welding. The conductive adhesive is, for example, a mixture of a thermosetting resin described below and carbon particles or metal particles.

   Hereinafter, the bent portion of the anode lead terminal 13 will be described in detail.

   As shown in FIG. 1, the anode lead terminal 13 includes two inner bent portions 130 inside the outer case 11 and two outer bent portions 131 outside the outer case 11. Further, as shown in an enlarged manner in FIG. 2, the inner bent portion 130 causes the anode lead terminal 13 extending from the joint W with the anode wire 2 to move the anode lead terminal 13 to the first main surface 13X side at a position not in contact with the anode wire 2. A first internal bent portion 1301 that bends the first internal bent portion 1301, a second internal bent portion 1302 that bends the anode lead terminal 13 bent at the first internal bent portion 1301 in a direction along the anode wire 2 and leads out of the exterior body 11. Is provided. On the other hand, the outer bent portion 131 includes a first outer bent portion 1311 that bends the anode lead terminal 13 derived from the exterior body 11 toward the first main surface 13X again, and an anode lead bent by the first outer bent portion 1311. The terminal 13 includes a second external bent portion 1312 that is bent along the outer shape of the exterior body 11 and disposed on the mounting surface 11 </ b> X of the exterior body 11. The bent portion is not limited to this, and may have another bent portion as long as the function of each bent portion is not hindered.

   In other words, the anode lead terminal 13 joined to the anode wire 2 has a joint W near one end 13T1, and has a first internal bending portion 1301 near the joint W. Subsequently, a second inner bent portion 1302, a first outer bent portion 1311 and a second outer bent portion 1312 are provided. Hereinafter, a region including the end 13T1 of the anode lead terminal 13 and the bonding portion W, a region up to the first internal bending portion 1301 is a bonding region R0, and a region from the first internal bending portion 1301 to the second internal bending portion 1302 is a bending region. A region from R1 and the second inner bent portion 1302 to the first outer bent portion 1311 is defined as a bent region R2. Further, a region from the first external bending portion 1311 to the second external bending portion 1312 includes a bending region R3, and a region including the other end 13T2 from the second external bending portion 1312 and a region arranged on the mounting surface 11X is defined as a bending region. R4. The size of each region is not particularly limited, and may be appropriately set according to the shape and size of the outer package 11, the length and diameter of the anode wire 2, and the like.

   The inner bent portion 130 is sealed together with the capacitor element 10 and arranged inside the exterior body 11. Therefore, the internal bent portion 130 is formed before the sealing step of sealing the capacitor element 10. Preferably, the inner bend 130 is formed before joining with the anode wire 2. Thereby, the internal bent portion 130 can be formed in the anode lead terminal 13 without applying a load to the anode wire 2. On the other hand, the outer bent portion 131 is exposed from the exterior body 11 without being sealed. Therefore, considering the sealing step, the outer bent portion 131 is formed after the sealing step. That is, the outer bent portion 131 is joined to the anode body 1 and formed on the anode lead terminal 13 including the inner bent portion 130. The inner bent portion 130 has a function of relaxing or absorbing the stress applied to the anode lead terminal 13 (and the anode wire 2 joined to the anode lead terminal 13) when the outer bent portion 131 is formed. Thereby, while joining of anode lead terminal 13 and anode wire 2 is maintained, displacement of anode wire 2 is suppressed, and separation of anode wire 2 and anode body 1 is suppressed. Hereinafter, a case where the second outer bent portion 1312 is formed after the first outer bent portion 1311 will be described as an example.

   The first inner bent portion 1301 is located near the junction W with the anode wire 2, and bends the anode lead terminal 13 toward the first main surface 13X at a position not in contact with the anode wire 2. The angle at which the anode lead terminal 13 is bent by the first inner bent portion 1301 (bending angle θ1) is not particularly limited, but is preferably 75 to 135 °. Thereby, the stress applied to the anode lead terminal 13 when the external bent portion 131 is formed is further easily reduced. The bending angle θ1 is an angle formed between the first main surface 13X in the joining region R0 and the first main surface 13X in the bending region R1.

   The second inner bent portion 1302 bends the anode lead terminal 13 bent at the first inner bent portion 1301 in a direction along the anode wire 2, and causes the anode lead terminal 13 to be led out of the exterior body 11. The angle (bending angle θ2) of bending of the anode lead terminal 13 by the second internal bending portion 1302 is not particularly limited, but is preferably 75 to 135 °. Thereby, the stress applied to the anode lead terminal 13 when the external bent portion 131 is formed is further easily reduced. The bending angle θ2 is an angle formed between the second main surface 13Y in the bending region R1 and the second main surface 13Y in the bending region R2. The first main surface 13X (or the second main surface 13Y) in the bending region R2 and the anode wire 2 may not be parallel, and the first main surface 13X (or the second main surface 13Y) and the anode wire in the bending region R2 may not be parallel. The angle formed with 2 may be 0 to 20 °.

   The first outer bent portion 1311 bends the anode lead terminal 13 led out of the exterior body 11 toward the first main surface 13X. When forming the first outer bent portion 1311, the anode lead terminal 13 is pulled toward the first main surface 13 </ b> X in a direction along the anode wire 2 and outside the capacitor element 10 (tensile force F <b> 1). Force (tensile force F2). The tensile force F <b> 1 acts to cause the joining region R <b> 0 of the anode lead terminal 13 to be laterally displaced and to separate the anode lead terminal 13 and the anode wire 2. The tensile force F2 acts to push up the bonding region R0 of the anode lead terminal 13 to the second main surface side, so that the anode lead terminal 13 and the anode wire 2 are separated.

   In the present embodiment, when the tensile force F1 is applied, the bending angle θ1 and the bending angle θ2 of the internal bending portion 130 increase. That is, the tensile force F1 applied to the anode lead terminal 13 is absorbed by the first internal bent portion 1301 and the second internal bent portion 1302 by a spring (spring) effect. Thereby, the lateral displacement of the anode lead terminal 13 in the joint region R0 or the lateral displacement of the anode wire 2 together with the joint region R0 is suppressed.

   In particular, the second internal bending portion 1302 exerts an effect on the tensile force F2. When the tensile force F2 acts, the second internal bending portion 1302 opens, and the bending angle θ2 increases. That is, the second inner bent portion 1302 exerts a stress that pushes the bent region R1 of the anode lead terminal 13 toward the second main surface 13Y. Since this stress acts in a direction to cancel the tensile force F2, the stress applied to the anode lead terminal 13 by the tensile force F2 is reduced. Therefore, the displacement of the anode wire 2 due to the peeling of the anode lead terminal 13 from the joint W or the pushing of the anode wire 2 to the second main surface 13Y together with the joint region R0 is suppressed.

   The second outer bent portion 1312 further bends the anode lead terminal 13 bent at the first outer bent portion 1311 along the outer shape of the outer package 11, and arranges the anode lead terminal 13 on the mounting surface 11X of the outer package 11. When forming the second outer bent portion 1312, the anode lead terminal 13 is pulled toward the first main surface 13 </ b> X (tensile force F <b> 3) and pulled in the direction along the anode wire 2 and inside the capacitor element 10. Force (tensile force F4). When the tensile force F3 is applied, as in the case of the tensile force F2, a stress acts to push up the second inner bent portion 1302 toward the second main surface 13Y. Therefore, the stress applied to the anode lead terminal 13 by the tensile force F3 is reduced. When the tensile force F4 is applied, a spring effect is generated as in the case of the tensile force F1. Therefore, the tensile force F4 applied to the anode lead terminal 13 is absorbed by the first internal bent portion 1301 and the second internal bent portion 1302.

   The angle (bending angle θ3) of bending of the anode lead terminal 13 by the first external bending portion 1311 is not particularly limited, and may be any angle as long as the bending region R3 is along the surface of the exterior body 11. The bending angle θ3 is, for example, 75 to 135 ° depending on the shape of the exterior body 11. The bending angle θ3 is an angle formed between the first main surface 13X in the bending region R2 and the first main surface 13X in the bending region R3.

   The angle (bending angle θ4) of bending of the anode lead terminal 13 by the second external bending portion 1312 is not particularly limited, and may be any angle as long as the bending region R3 is along the surface of the exterior body 11. The bending angle θ4 is, for example, 75 to 135 ° depending on the shape of the exterior body 11. The bending angle θ4 is an angle formed by the first main surface 13X in the bending region R3 and the first main surface 13X in the bending region R4.

   Further, the formation of the inner bent portion 130 allows the anode lead terminal 13 to be led out from an arbitrary position of the exterior body 11. That is, by adjusting the positions of the first inner bent portion 1301 and the second inner bent portion 1302, the anode lead terminal 13 can be moved from an arbitrary position of the exterior body 11 without changing the position of the capacitor element 10 in the electrolytic capacitor 20. Can be derived.

   Conventionally, when the position of a capacitor element in an electrolytic capacitor is changed, the thickness of an exterior body that covers the capacitor element may be different between the mounting surface side and the opposite non-mounting surface side. In this case, there is a concern that a part of the capacitor element is exposed from the side where the thickness of the exterior body is small. If the thickness of the exterior body is increased in order to avoid such exposure, the thickness of the electrolytic capacitor is also increased, so that it is not possible to satisfy the demand for a reduction in height.

   Further, the bent region R <b> 2 of the anode lead terminal 13 can be arranged on a plane including the anode wire 2 by the internal bent portion 130. The anode wire 2 is usually arranged so as to pass through the center of the capacitor element 10. Therefore, when the capacitor element 10 is sealed, the position of the anode lead terminal 13 having the bent region R2 on the plane is led out of the exterior body 11 from a position where the thickness T of the electrolytic capacitor 20 is equally divided. By adjusting (see FIG. 1), the thickness from the outer surface of the capacitor element 10 to the exterior body 11 can be made equal between the mounting surface 11X side and the opposite non-mounting surface 11Y side. Thereby, the appearance of the obtained electrolytic capacitor 20 is also improved. The thickness T is the maximum length of the electrolytic capacitor 20 in the thickness direction of the anode lead terminal 13 when the cross section perpendicular to the first main surface 13X and along the anode wire 2 is viewed.

   Incidentally, when sealing the capacitor element 10, an upper mold and a lower mold are usually used. Sealing is performed while supporting the capacitor element 10 with the anode lead terminal 13 and the cathode lead terminal 14 interposed between these molds. In this case, the inner bent portion 130 is formed so that the anode lead terminal 13 joined to the anode wire 2 is arranged on the same plane as the cathode lead terminal 14 drawn out from the joint with the cathode portion 7. Thereby, control of the thickness of the exterior body 11 becomes easy, and exposure of the capacitor element 10 from the exterior body 11 can be avoided. In addition, when the capacitor element 10 before sealing is placed on a horizontal surface, if the heights of the drawn anode lead terminal 13 and the cathode lead terminal 14 are different, the capacitor element 10 supported by these is inclined. It will be housed in the mold. Therefore, the capacitor element 10 may be exposed in a portion where the thickness of the exterior body 11 is small.

(Cathode lead terminal)
The cathode lead terminal 14 is electrically connected to the cathode section 7. The material of the cathode lead terminal 14 is not particularly limited as long as it is electrochemically and chemically stable and has conductivity, and may be metal or nonmetal. The shape is not particularly limited, either. For example, it is long and flat. The thickness of the cathode lead terminal 14 is preferably from 25 to 200 μm, more preferably from 25 to 100 μm, from the viewpoint of reducing the height. The cathode lead terminal 14 is joined to the cathode layer 5 via, for example, the conductive adhesive 8.

   Regarding the cathode lead terminal 14, the presence or absence of the bent portion and the position of the junction with the cathode layer 5 are not particularly limited. Here, a part of the cathode lead terminal 14 is arranged on the mounting surface 11X together with the anode lead terminal 13. It is preferable that another part of the cathode lead terminal 14 is joined to the cathode portion 7 (cathode layer 5) on the non-mounting surface 11Y side opposite to the mounting surface 11X, as described later. This is because the manufacturing of the electrolytic capacitor 20 is simplified. From these points, it is preferable that the cathode lead terminal 14 also includes the inner bent portion 140 and the outer bent portion 141 (see FIG. 1), like the anode lead terminal 13.

   That is, it is preferable that the cathode lead terminal 14 is joined to the cathode layer 5 on the non-mounting surface 11Y side and has the following internal bent portion 140. The inner bent portion 140 is a first inner bent portion that bends the cathode lead terminal 14 extending from the junction with the cathode layer 5 toward the mounting surface 11X (to the first main surface 13X side of the anode lead terminal 13). 1401, and a second internal bent portion 1402 that bends the cathode lead terminal 14 bent at the first internal bent portion 1401 in a direction along the anode wire 2 and leads the cathode lead terminal 14 out of the exterior body 11.

   Further, it is preferable that the cathode lead terminal 14 includes an external bent portion 141 described below. The outer bent portion 141 is configured to bend the cathode lead terminal 14 derived from the exterior body 11 toward the mounting surface 11X (toward the first main surface 13X side of the anode lead terminal 13), and a first outer bent portion 1411. A second external bent portion 1412 is provided in which the cathode lead terminal 14 bent at the outer bent portion 1411 is bent along the outer shape of the outer case 11 and arranged on the mounting surface 11X of the outer case 11. Also in this case, the inner bent portion 140 has an action of relaxing the stress applied to the cathode lead terminal 14 when the two outer bent portions 141 are formed. Thereby, the junction between the cathode lead terminal 14 and the cathode layer 5 is maintained. The bent portion is not limited to this, and may have another bent portion as long as the function of each bent portion is not hindered.

<Outer 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 includes, for example, a cured product of a thermosetting resin. Examples of the thermosetting resin include an epoxy resin, a phenol resin, a silicone resin, a melamine resin, a urea resin, an alkyd resin, a polyurethane, a polyimide, and an unsaturated polyester.

   The exterior body 11 accommodates, for example, 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 having an upper mold and a lower mold, and performs transfer molding. It is formed by a method or a compression molding method. At this time, a part of the anode lead terminal 13 and a part of the cathode lead terminal 14 are led out of the exterior body 11.

製造 Method of manufacturing electrolytic capacitors コ ン デ ン サ
An example of a method for manufacturing the electrolytic capacitor 20 according to the embodiment will be described.

   The electrolytic capacitor 20 includes, for example, a preparation step of preparing the capacitor element 10, an anode lead terminal 13 having an internal bent portion 130, and a cathode lead terminal 14 having an internal bent portion 140, and a step of preparing an anode disposed at a predetermined position. The capacitor element 10 is mounted on the lead terminal 13 and the cathode lead terminal 14, a part of the first main surface 13 </ b> X of the anode lead terminal 13 is joined to the anode wire 2, and a part of the cathode lead terminal 14 is connected to the cathode part. 7; a sealing step of sealing the inner bent portions of the anode lead terminal 13 and the cathode lead terminal 14 and the capacitor element 10 to form the exterior body 11; The lead-out anode lead terminal 13 and cathode lead terminal 14 are bent to form an external bent portion, and the anode lead terminal 13 and cathode lead A bending step of placing a portion of the pin 14 on the mounting surface 11X of the exterior body 11, by a method comprising, it can be produced.

(1) Preparation Step First, the capacitor element 10 is prepared. Hereinafter, a method for manufacturing the capacitor element 10 will be described in detail.

   The valve metal particles and the anode wire 2 are put into a mold so that the first portion 2a is embedded in the valve metal particles, pressed, and then sintered in a vacuum, so that the first portion 2a is porous sintered. An anode part 6 to be buried therein is produced from one surface of the body. The pressure at the time of pressure molding is not particularly limited, and is, for example, about 10 to 100N. If necessary, a binder such as polyacrylic carbonate may be mixed with the valve action metal particles.

   Next, a dielectric layer 3 is formed on the anode body 1. Specifically, the anode body 1 is immersed in a chemical conversion tank 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 conversion tank to perform anodic oxidation. By performing the above, the dielectric layer 3 made of an oxide film of a valve 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.

   Subsequently, the solid electrolyte layer 4 is formed. In the present embodiment, a process of forming the solid electrolyte layer 4 containing a conductive polymer will be described.

   The solid electrolyte layer 4 containing a conductive polymer is formed, for example, by impregnating the anode body 1 on which the dielectric layer 3 is formed with a monomer or oligomer, and then polymerizing the monomer or oligomer by chemical polymerization or electrolytic polymerization, Alternatively, the anode body 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 portion on the dielectric layer 3.

   Finally, the cathode layer 5 composed of the carbon layer 5a and the metal paste layer 5b is formed by sequentially applying a carbon paste and a metal paste on the surface of the solid electrolyte layer 4. The configuration of the cathode layer 5 is not limited to this, and may be any configuration having a current collecting function.

   The capacitor element 10 is manufactured by the above method.

   Second, an anode lead terminal 13 and a cathode lead terminal 14 are prepared.

   Internal bent portions (130, 140) are formed on the anode lead terminal 13 and the cathode lead terminal 14, respectively. The inner bent portion is formed by, for example, press working. The position of the inner bent portion 130 of the anode lead terminal 13 may be appropriately set according to the length, diameter, and the like of the anode wire 2. The position of the internal bent portion 140 of the cathode lead terminal 14 may be set as appropriate according to the shape and size of the capacitor element 10.

(2) Lead Terminal Bonding Step The anode lead terminal 13 and the cathode lead terminal 14 each having the internal bent portion are arranged at predetermined positions. At this time, the anode wire 2 is in contact with a part of the first main surface 13X of the anode lead terminal 13, and the first main surface 13X is connected to the mounting surface 11X of the exterior body 11 formed in a later step. The anode lead terminals 13 are arranged so as to face each other. Furthermore, the cathode lead terminal 14 is arranged so that the cathode lead terminal 14 contacts the cathode portion 7 (cathode layer 5) on the non-mounting surface 11Y side opposite to the mounting surface 11X. At this time, a conductive adhesive 8 is applied to a predetermined position of the cathode layer 5.

   With the lead terminals arranged, the capacitor element 10 is placed from the first main surface 13X side. Next, the second portion 2b of the anode wire 2 and the vicinity of one end 13T1 of the anode lead terminal 13 are joined by laser welding, resistance welding, or the like. At this time, the vicinity of one end of the cathode lead terminal 14 is joined to the cathode layer 5 via the conductive adhesive 8.

   Thereby, the anode lead terminal 13 is joined to the non-mounting surface 11Y side of the anode wire 2, and the cathode lead terminal 14 is joined to the non-mounting surface 11Y side of the cathode portion 7. That is, since both the anode lead terminal 13 and the cathode lead terminal 14 are joined to the non-mounting surface 11Y side of each member, the mounting of the capacitor element 10 on each lead terminal can be performed in one step. The process is simplified.

(3) Sealing Step The materials of the capacitor element 10 and the exterior body 11 (for example, uncured thermosetting resin and filler) are accommodated in a mold, and the capacitor element 10 is sealed by a transfer molding method, a compression molding method, or the like. Stop. At this time, a part of the anode lead terminal 13 and a part of the cathode lead terminal 14 are exposed from the mold. The molding conditions are not particularly limited, and time and temperature conditions may be appropriately set in consideration of the curing temperature of the thermosetting resin to be used.

(4) Bending Step Finally, the portions of the anode lead terminal 13 and the cathode lead terminal 14 exposed from the mold are bent along guides to form external bent portions (131, 141), respectively. Thus, a part of the anode lead terminal 13 and a part of the cathode lead terminal 14 are arranged on the mounting surface 11X of the exterior body 11.

   The electrolytic capacitor 20 is manufactured by the above method.

   INDUSTRIAL APPLICABILITY The electrolytic capacitor according to the present invention can be used for various applications because the leakage current is reduced and the connection reliability is excellent.

Reference Signs List 20: electrolytic capacitor 10: capacitor element 10Y: facing surface 1: anode body 2: anode wire 2a: first portion of anode wire 2b: second portion 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 11X: Mounting surface 11Y: Non-mounting surface 13: Anode lead terminal 13X: First main surface 13Y: Second main surface 13T1, 13T2: End 130: Internal bent portion 1301: First internal bent portion 1302: Second internal bent portion 131: External bent portion 1311: First external bent portion 1312: Second external bent portion 14: Cathode lead terminal 140: Internal bent portion 1401: first internal bend 1402: second internal bend 141: external bend 1411: first external bend 1412: second external bend 120: electrolytic condenser Sensor 110: capacitor element 102: anode wire 111: exterior body 113: anode lead terminal

Claims (3)

A capacitor element having an anode part and a cathode part,
An anode lead terminal electrically connected to the anode portion and having a first main surface and a second main surface;
A cathode lead terminal electrically connected to the cathode portion;
An electrolytic capacitor that covers the capacitor element and that exposes at least a part of each of the anode lead terminal and the cathode lead terminal.
The anode section has an anode body, an anode wire extending from the anode body, and joined to the first main surface of the anode lead terminal,
The anode lead terminal includes an internal bent portion inside the exterior body, and an external bent portion outside the exterior body,
A first internal bent portion, wherein the internal bent portion bends the anode lead terminal extending from a joint portion with the anode wire toward the first main surface at a position not in contact with the anode wire; A second internal bending portion that bends the anode lead terminal bent at the internal bending portion in a direction along the anode wire, and that is derived from the exterior body.
The outer bent portion includes a first outer bent portion that bends the anode lead terminal derived from the outer package toward the first main surface, and the anode lead terminal bent by the first outer bent portion. A second external bent portion that is bent along the outer shape of the body and disposed on the mounting surface of the outer body.    The electrolytic capacitor according to claim 1, wherein a region between the second inner bent portion and the first outer bent portion of the anode lead terminal is on a plane including the anode wire. A part of the cathode lead terminal is exposed on the mounting surface of the exterior body, and another part of the cathode lead terminal is a non-mounting surface opposite to the mounting surface of the cathode part. 3. The electrolytic capacitor according to claim 1, wherein the electrolytic capacitor is joined by:

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