Electrolytic capacitor

Abstract

An electrolytic capacitor 100 includes a capacitor element 110 and a cathode lead terminal 130. The capacitor element 110 includes an anode body 113 and a cathode part 115. The cathode lead terminal 130 includes a connection part 133 that is connected to the cathode part 115 with a conductive member 141 therebetween. The connection part 133 includes a plate-like part 133a and first and second lateral walls rising from plate-like part 133a. A plurality of grooves 133g are formed in the surfaces of the first and second lateral walls and the plate-like part 133a. The grooves 133g include multiple first and second grooves formed so as to be connected from the plate-like part 133a over the first and second lateral walls. The conductive member 141 is disposed between one surface of the cathode part 115 and the plate-like part 133a and between the two lateral surfaces of the cathode part 115 and the first and second lateral walls.

Description

Technical Field

[0001] The present disclosure relates to an electrolytic capacitor.

Background Art

[0002] Electrolytic capacitors are mounted in various electronic devices. An electrolytic capacitor generally includes a capacitor element having an anode portion and a cathode portion, an anode lead terminal, a cathode lead terminal, and an exterior resin covering the capacitor element. The anode lead terminal is electrically connected to the anode portion, and the cathode lead terminal is electrically connected to the cathode portion.

[0003] Conventionally, cathode lead terminals of various shapes have been proposed (for example, Patent Documents 1 to 3). Patent Document 1 discloses "an electrolytic capacitor characterized in that recesses formed of a plurality of grooves or dents are provided on the surface of the cathode lead frame in contact with the conductive adhesive and on the surface in contact with the exterior resin."

[0004] FIG. 7 of Patent Document 2 discloses that both sides of the cathode lead terminal are bent upward to form a fitting portion.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] In an electrolytic capacitor, reduction of ESR and the like are required. In such a situation, one object of the present disclosure is to provide an electrolytic capacitor having a low ESR.

Means for Solving the Problem

[0007] One aspect of the present disclosure relates to an electrolytic capacitor. The electrolytic capacitor includes a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element. The capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on its surface, an anode wire protruding from an end face of the anode body, and a cathode portion disposed adjacent to the dielectric layer. The cathode portion has first and second side surfaces, and a bottom surface and a top surface connecting the first and second side surfaces. The cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member. The connection portion includes a plate-like portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and first and second side walls rising from the plate-like portion and facing the first and second side surfaces, respectively. A plurality of grooves are formed on the surface of the cathode portion side of the plate-like portion and the first and second side walls. The plurality of grooves include a plurality of first grooves formed so as to connect from the plate-like portion to the first side wall, and a plurality of second grooves formed so as to connect from the plate-like portion to the second side wall. The conductive member is disposed between the one surface and the plate-like portion, between the first side surface and the first side wall, and between the second side surface and the second side wall.

[0008] Another aspect of the present disclosure relates to other electrolytic capacitors. The other electrolytic capacitor is an electrolytic capacitor including a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element, wherein the capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on a surface thereof, an anode wire protruding from an end surface of the anode body, and a cathode portion disposed so as to surround the anode body, the cathode portion having two side surfaces, and a bottom surface and a top surface connecting the two side surfaces, the cathode lead terminal including a connection portion connected to the cathode portion via the conductive member, the connection portion including a plate-like portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and two side walls rising from the plate-like portion and facing the two side surfaces respectively, the conductive member being disposed between the one surface and the plate-like portion, and between the two side surfaces and the two side walls facing the two side surfaces, and a volume between the cathode portion and the two side walls increasing as the distance from the end surface increases.

[0009] Another aspect of the present disclosure relates to other electrolytic capacitors. The other electrolytic capacitor is an electrolytic capacitor including a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element, wherein the capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on a surface thereof, an anode wire protruding from an end face of the anode body, and a cathode portion disposed so as to surround the anode body, the cathode portion has two side surfaces, and a bottom surface and a top surface connecting the two side surfaces, the cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member, the connection portion includes a plate-like portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and two side walls rising from the plate-like portion and facing the two side surfaces respectively, the conductive member is disposed between the one surface and the plate-like portion, and between the two side surfaces and the two side walls facing the two side surfaces, and end portions of the two side walls on the end face side are farther from the end face than an end portion of the plate-like portion on the end face side.

Advantages of the Invention

[0010] According to the present disclosure, an electrolytic capacitor with low ESR can be obtained. The novel features of the present invention are described in the appended claims, but the present invention relates to both the configuration and the content, and will be better understood from the following detailed description in conjunction with the drawings, along with other objects and features of the present invention.

Brief Description of the Drawings

[0011]

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Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the first to third electrolytic capacitors according to the present disclosure will be described with examples. However, the electrolytic capacitor according to the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be exemplified, but other numerical values and materials may be applied as long as the effects of the present disclosure can be obtained. Note that known components of an electrolytic capacitor may be applied to the components other than the characteristic parts of the present disclosure. In this specification, when referring to "the range of numerical value A to numerical value B", the range includes numerical value A and numerical value B.

[0013] (First Electrolytic Capacitor) The first electrolytic capacitor of the present disclosure includes a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element. The capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on its surface, an anode wire protruding from an end face of the anode body, and a cathode portion disposed adjacent to the dielectric layer. The cathode portion has first and second side surfaces, and a bottom surface and a top surface connecting the first and second side surfaces. The cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member. The connection portion includes a plate-shaped portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and first and second side walls rising from the plate-shaped portion and facing the first and second side surfaces, respectively. A plurality of grooves are formed on the surfaces of the plate-shaped portion and the first and second side walls on the cathode portion side. The plurality of grooves includes a plurality of first grooves formed to connect from the plate-shaped portion to the first side wall, and a plurality of second grooves formed to connect from the plate-shaped portion to the second side wall. The conductive member is disposed between the one surface and the plate-shaped portion, between the first side surface and the first side wall, and between the second side surface and the second side wall. That is, the conductive member contacts and connects the one surface and the plate-shaped portion, contacts and connects the first side surface and the first side wall, and contacts and connects the second side surface and the second side wall.

[0014] The anode lead terminal and the cathode lead terminal may each include an anode terminal portion and a cathode terminal portion exposed on the surface of the electrolytic capacitor. When mounting the electrolytic capacitor, these anode terminal portions and cathode terminal portions are joined to a substrate or the like by solder or the like. In this specification, the side on which the anode terminal portion and the cathode terminal portion are exposed may be referred to as the bottom side, and the side opposite to the bottom side may be referred to as the top side.

[0015] The anode body is, for example, in the shape of a rectangular parallelepiped, and has a bottom surface on the side of the anode terminal portion and the cathode terminal portion, an upper surface facing the bottom surface, an end surface (E) from which the anode lead terminal protrudes, first and second side surfaces, and a surface facing the end surface (E). The first and second side surfaces are connected to the end surface (E), the bottom surface, and the upper surface. The first and second side surfaces of the cathode portion are the outer surfaces of the cathode portion formed on the first and second side surfaces of the anode body. The bottom surface of the cathode portion is the outer surface of the cathode portion formed on the bottom surface of the anode body. The upper surface of the cathode portion is the outer surface of the cathode portion formed on the upper surface of the anode body.

[0016] The cathode portion is formed so as to surround the anode body with a dielectric layer interposed therebetween. The cathode portion may be formed with a dielectric layer interposed therebetween on five surfaces of the surface of the anode body excluding the end surface (E) from which the anode lead protrudes. In that case, the cathode portion is formed in a rectangular tube shape with one end closed.

[0017] In order to lower the ESR, it is necessary to increase the connection area between the cathode portion and the cathode lead terminal. In the case of the electrolytic capacitor of Patent Document 1, in order to increase the connection area between the cathode portion and the cathode lead terminal, it is conceivable to apply a conductive adhesive to the entire surface of the cathode lead terminal facing the cathode portion. However, if this is done, there is a risk that the applied conductive adhesive may protrude from between the cathode portion and the cathode lead terminal, causing problems in coating with the exterior resin or problems such as short circuits. Further, in the electrolytic capacitor of Patent Document 1, when connecting the cathode portion of the capacitor element and the cathode lead terminal, it may be difficult to hold the capacitor element in a stable position.

[0018] On one hand, the connection part of the first electrolytic capacitor includes a plate-shaped part and first and second side walls. Therefore, even when a large amount of conductive material (a material that becomes a conductive member, such as a metal paste) is arranged between the plate-shaped part and the cathode part to increase the connection area between the plate-shaped part and the cathode part, the excess conductive material moves between the first and second side walls of the connection part and the cathode part, and is suppressed from protruding from the connection part. Also, according to this configuration, the plate-shaped part and the first and second side walls of the connection part are connected to the cathode part by the conductive member. Therefore, the connection area between the plate-shaped part and the cathode part can be increased, and the ESR can be reduced.

[0019] In particular, a groove that extends across the plate-shaped part and the first and second side walls is formed in the connection part of the first electrolytic capacitor. This groove makes it easier for the conductive material arranged on the surface of the plate-shaped part and / or the surface of the cathode part to move between the first and second side walls and the plate-shaped part. Therefore, according to the first electrolytic capacitor, it is particularly easy to increase the connection area between the plate-shaped part and the cathode part. Furthermore, by forming a groove in the connection part, it is possible to enhance the anchor effect and increase the adhesive force between the connection part and the cathode part. That is, according to this configuration, a highly reliable electrolytic capacitor can be obtained.

[0020] Furthermore, in the first electrolytic capacitor, when connecting the capacitor element and the cathode lead terminal, the movement of the capacitor element is restricted by the first and second side walls of the cathode lead terminal. Therefore, the positioning of the capacitor element is easy, and it is possible to prevent the capacitor element from shifting and being connected to the cathode lead terminal. Therefore, according to the present disclosure, an electrolytic capacitor that is easy to manufacture and highly reliable can be obtained.

[0021] There are no particular limitations on the width, depth, number, and area of the groove formed in the connection part of the cathode lead terminal. There are also no particular limitations on the number of grooves to be formed.

[0022] The direction in which the anode wire extends may hereinafter be referred to as "direction D1". The end of the connection part (the end on the end face (E) side) may be present on the end face (E) side rather than at the center of the anode body (the center in direction D1). According to this configuration, it is possible to increase the area of the connection part connected to the cathode part by the conductive member.

[0023] The plate-like part, the first side wall, and the second side wall of the connection part may each be rectangular, or may have a shape other than rectangular.

[0024] A conductive member may be arranged in the first groove so as to connect from the plate-like part to the first side wall, and a conductive member may be arranged in the second groove so as to connect from the plate-like part to the second side wall. According to this configuration, a particularly high anchor effect can be obtained.

[0025] Each of the plurality of first grooves may be connected to a corresponding groove among the plurality of second grooves to form a single groove. That is, the plurality of grooves may be connected from the plate-like part to the first and second side walls.

[0026] Each of the plurality of grooves may extend in a direction substantially perpendicular to the direction in which the anode wire extends. According to this configuration, the conductive material arranged on the surface of the plate-like part and / or the cathode part facing the plate-like part easily moves between the first and second side walls and the plate-like part. Here, the substantially perpendicular direction means a direction in which the inclination with respect to the perpendicular direction is less than 10°.

[0027] As long as each groove is formed so as to connect from the connection part to the side wall part, the arrangement of the plurality of grooves may be an arrangement other than the above-described arrangement. For example, the plurality of grooves may intersect in a lattice pattern. Even in that case, each groove is connected from the connection part to the side wall part. Each of the plurality of grooves may be linear, may be curved, or may have a shape combining a plurality of straight lines and / or a plurality of curves.

[0028] Of the plurality of grooves, the grooves formed in the first and second side walls may each be formed so as to be farther from the end face (E) as they are farther from the plate-like portion. According to this configuration, it becomes easier to guide the material of the conductive member disposed between the side wall and the cathode portion to a position farther from the end face (E). As a result, it becomes easier to prevent a short circuit between the anode portion and the cathode portion.

[0029] Grooves may also be formed on the surfaces of the plate-like portion of the connection portion and the first and second side walls that are opposite to the surfaces on the cathode portion side. And an exterior resin may be disposed in the grooves on the opposite surfaces. According to this configuration, the adhesive strength between the exterior resin and the connection portion can be improved by the anchor effect.

[0030] The first and second side walls of the connection portion may be substantially parallel to the first and second side surfaces of the anode body. That is, the first and second side walls of the connection portion may rise substantially perpendicularly from the plate-like portion. For example, the angle formed by the plate-like portion and the first side wall, and the angle formed by the plate-like portion and the second side wall may be 90° or more and less than 100°. Alternatively, the first and second side walls of the connection portion may be formed so as to be farther apart from each other as they are farther from the plate-like portion. For example, the angle formed by the plate-like portion and the first side wall, and the angle formed by the plate-like portion and the second side wall may be 100° or more and 120° or less. According to this configuration, even when the amount of the conductive material, which is the material of the conductive member, is large, it is possible to suppress the conductive material from protruding from the second side wall.

[0031] (Second electrolytic capacitor) The second electrolytic capacitor includes a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element. The capacitor element includes an anode body which is a porous sintered body having a dielectric layer formed on its surface, an anode wire protruding from an end face of the anode body, and a cathode portion disposed so as to surround the anode body. The cathode portion has two side faces, and a bottom face and a top face connecting the two side faces. The cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member. The connection portion includes a plate-like portion facing either one of the bottom face and the top face of the cathode portion with the conductive member interposed therebetween, and two side walls rising from the plate-like portion and facing the two side faces of the cathode portion respectively. The conductive member is disposed between the one face and the plate-like portion of the connection portion, and between the two side faces of the cathode portion and the two side walls of the connection portion facing the two side faces. The volume between the cathode portion and the two side walls increases as it moves away from the end face (E) of the anode body. Hereinafter, the end face of the anode body from which the anode wire protrudes may be referred to as "end face (E)".

[0032] In the second and third capacitors, the two side faces of the cathode portion can be read as the first side face and the second side face, and the two side walls of the connection portion can be read as the first and second side walls. The first side face and the second side face of the cathode portion face the first side wall and the second side wall of the connection portion respectively.

[0033] The cathode portion and the cathode lead terminal are connected by the conductive member. The conductive member can be formed, for example, by applying a conductive material which is the material of the conductive member to the plate-like portion of the cathode portion and / or the cathode lead terminal, and then changing the conductive material into the conductive member by heating or the like.

[0034] To lower the ESR, it is necessary to increase the connection area between the cathode part and the connection part of the cathode lead terminal. For this purpose, it is necessary to increase the area of the conductive member, and it is conceivable to apply a conductive material over a wide range of the surface of the connection part. However, if a large amount of conductive material is applied to increase the area of the conductive member, there is an increased possibility of problems such as excess conductive material protruding from the plate-like part and short-circuiting between the anode wire and the cathode part.

[0035] In the second electrolytic capacitor, the connection part of the cathode lead terminal has side walls. Therefore, it is possible to connect between the side walls and the cathode part with a conductive member. As a result, a low ESR can be achieved. Also, in the second electrolytic capacitor, the volume between the cathode part and the two side walls increases as it moves away from the end face (E) of the anode body. Therefore, even if a large amount of conductive material is applied, the excess conductive material is induced in the direction away from the end face (E) where the anode wire is present. Therefore, it is possible to suppress the protruding conductive material from reaching the end face (E), and it is possible to suppress problems such as short-circuiting between the anode part and the cathode part. That is, the second electrolytic capacitor can be manufactured with good yield. Also, according to this configuration, since it is possible to apply a large amount of conductive adhesive, it is possible to increase the area of the conductive member. As a result, it is possible to lower the ESR.

[0036] The width of the plate-like part of the connection part of the cathode lead terminal may increase as it moves away from the end face (E) at least in the part connected to the two side walls. In this case, the angle α1 formed between the direction in which the side wall of the connection part extends and the side surface of the cathode part (more specifically, the surface including the side surface) may be in the range of 5 to 20°.

[0037] Alternatively, the plate-shaped portion of the connection part of the cathode lead terminal may be rectangular. And the distance between each of the two side walls of the connection part and the cathode part may increase as the distance from the end face (E) and the distance from the plate-shaped portion increase. In this case, the angle α2 formed between the direction in which the upper side of the side wall of the connection part extends and the side surface of the cathode part (more specifically, the surface including the side surface) may be in the range of 5 to 20°. Here, the upper side means the side of the side wall that is farthest from the plate-shaped portion of the connection part.

[0038] The distance X1 between the end portion on the end face (E) side of the plate-shaped portion and the end face (E) in the direction D1 in which the anode wire 112 extends, and the distance Y1 between the end portions on the end face (E) side of the two side walls and the end face (E) in the direction D1 may each be in the range of 10 to 40% (for example, in the range of 20 to 30%) of the length L1 of the anode body in the direction D1. Note that the distance X1 and the distance Y1 may be different, but typically they are the same.

[0039] (Third electrolytic capacitor) The third electrolytic capacitor includes a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element. The capacitor element includes an anode body that is a porous sintered body with a dielectric layer formed on its surface, an anode wire protruding from the end face of the anode body, and a cathode part disposed so as to surround the anode body. The cathode part has two side surfaces, and a bottom surface and a top surface connecting the two side surfaces. The cathode lead terminal includes a connection part connected to the cathode part via a conductive member. The connection part includes a plate-shaped portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and two side walls rising from the plate-shaped portion and facing the two side surfaces respectively. The conductive member is disposed between the one surface and the plate-shaped portion of the connection part, and between the two side surfaces of the cathode part and the two side walls of the connection part facing the two side surfaces. The end portions on the end face side of the two side walls are farther from the end face than the end portion on the end face side of the plate-shaped portion.

[0040] Since only the shape of the connection portion of the cathode lead terminal of the third electrolytic capacitor is different from that of the second electrolytic capacitor, duplicate explanations may be omitted.

[0041] In the above-mentioned third electrolytic capacitor, the connection portion of the cathode lead terminal has side walls. Therefore, it is also possible to connect between the side walls and the cathode portion with a conductive member. As a result, a low ESR can be achieved. Further, in the third electrolytic capacitor, the end portions on the end face (E) side of the two side walls of the connection portion are farther from the end face (E) than the end portions on the end face (E) side of the plate-shaped portion of the connection portion. Therefore, even when a large amount of conductive material (the material of the conductive member) is applied and the excess conductive material protrudes, it is likely to protrude from the end portions on the end face (E) side of the side walls. Therefore, it is possible to suppress the conductive adhesive from reaching the end face (E) and causing a short circuit or the like. That is, the third electrolytic capacitor can be manufactured with a high yield. Further, according to this configuration, since it is possible to apply a large amount of conductive adhesive, it is possible to increase the area of the conductive member. As a result, it is possible to reduce the ESR.

[0042] The third electrolytic capacitor may satisfy the following configuration (1). (1) The distance X2 in the direction D2, which is the distance between the end portion on the end face (E) side of the plate-shaped portion of the connection portion of the cathode lead terminal and the end face (E), is in the range of 10 to 50% (for example, 30 to 45%) of the length L2 of the anode body in the direction D2.

[0043] The third electrolytic capacitor may satisfy the above configuration (1) and the following configuration (2). (2) The difference (Y2 - X2) between the distance Y2 in the direction D2, which is the distance between the end portions on the end face (E) side of the two side walls of the connection portion and the end face (E), and the distance X2 is in the range of 10 to 50% (for example, 30 to 45%) of the length L2.

[0044] The electrolytic capacitor according to the present disclosure can satisfy at least one condition selected from the group consisting of the following conditions (J1), (J2), and (J3). For example, the first electrolytic capacitor may satisfy condition (J2) and / or (J3). The second capacitor may satisfy condition (J3). In the following (J1) to (J3), the "one surface" refers to the surface of the bottom surface and the upper surface of the cathode portion where the plate-like portion faces across the conductive member. (J1) A plurality of grooves are formed on the surface on the cathode portion side among the surfaces of the plate-like portion and the first and second side walls. The plurality of grooves includes a plurality of first grooves formed so as to connect from the plate-like portion to the first side wall and a plurality of second grooves formed so as to connect from the plate-like portion to the second side wall. The conductive member is disposed between the one surface and the plate-like portion, between the first side surface and the first side wall, and between the second side surface and the second side wall. (J2) The conductive member is disposed between the one surface and the plate-like portion, and between the two side surfaces (the first and second side surfaces) and the two side walls (the first and second side walls) facing the two side surfaces. The volume between the cathode portion and the two side walls increases as it moves away from the end surface. (J3) The conductive member is disposed between the one surface and the plate-like portion, and between the two side surfaces (the first and second side surfaces) and the two side walls (the first and second side walls) facing the two side surfaces. The end portions on the end surface side of the two side walls are farther from the end surface than the end portions on the end surface side of the plate-like portion.

[0045] Examples of the components common to the first to third electrolytic capacitors of the present disclosure will be described below.

[0046] (Cathode lead terminal) The cathode lead terminal has the above-described characteristics. A typical cathode lead terminal includes a cathode terminal portion exposed on the bottom surface of the electrolytic capacitor and a connection portion connected to the cathode terminal portion. As described above, the connection portion is connected to the cathode portion via a conductive member.

[0047] The material of the cathode lead terminal may be any material that can be used as the material of the cathode lead terminal of the electrolytic capacitor. For example, a known material for the cathode lead terminal used in an electrolytic capacitor may be used. The cathode lead terminal may be formed by processing a metal sheet (including a metal plate and a metal foil) made of a metal (such as copper or a copper alloy) by a known metal processing method.

[0048] (Anode lead terminal) A typical anode lead terminal includes an anode terminal portion exposed on the bottom surface of the electrolytic capacitor and a wire connection portion connected to the anode terminal portion. The wire connection portion is connected to the anode wire. The material of the anode lead terminal may be any material that can be used as the material of the anode lead terminal of the electrolytic capacitor. For example, a known material for the anode lead terminal used in an electrolytic capacitor may be used. The anode lead terminal may be formed by processing a metal sheet (including a metal plate and a metal foil) made of a metal (such as copper or a copper alloy) by a known metal processing method.

[0049] (Capacitor element) The capacitor element includes an anode portion and a cathode portion. There is no particular limitation on the capacitor element, and a capacitor element used in a known electrolytic capacitor or a capacitor element having a similar configuration may be used.

[0050] The anode portion includes an anode body and an anode wire. The anode body is a porous sintered body having a dielectric layer formed on its surface. The cathode portion includes an electrolyte layer and a cathode layer. The electrolyte layer is disposed between the dielectric layer formed on the surface of the anode body and the cathode layer. There is no particular limitation on these components, and components used in known electrolytic capacitors may be applied. Examples of these components will be described below.

[0051] (Anode body) The anode body is formed by sintering particles as the material. Examples of the above particles include particles of valve metal, particles of an alloy containing valve metal, and particles of a compound containing valve metal. These particles may be used alone or in combination of two or more. As the valve metal, titanium (Ti), tantalum (Ta), niobium (Nb), etc. are used.

[0052] The anode body may be manufactured by the following method. First, a part of the anode wire is embedded in the powder (for example, metal powder) which is the material of the anode body, and the powder is pressure-molded into a columnar shape (for example, a rectangular parallelepiped shape). Then, the anode body is formed by sintering the powder. In this way, an anode body with a part of the anode wire embedded therein can be manufactured.

[0053] There is no particular limitation on the dielectric layer formed on the surface of the anode body, and it may be formed by a known method. For example, the dielectric layer may be formed by immersing the anode body in a forming solution and anodizing the surface of the anode body. Alternatively, the dielectric layer may be formed by heating the anode body in an atmosphere containing oxygen and oxidizing the surface of the anode body.

[0054] (Anode wire) The anode wire may be a wire made of metal. Examples of the material of the anode wire include the above-mentioned valve metal, copper, aluminum, aluminum alloy, etc. A part of the anode wire is embedded in the anode body, and the remaining part protrudes from the end face (E) of the anode body. The anode wire has a rod-like shape. The tip of the anode wire protruding from the anode body may have a cross-sectional shape different from that of other parts.

[0055] (Electrolyte layer) There is no particular limitation on the electrolyte layer, and an electrolyte layer used in a known electrolytic capacitor (for example, a solid electrolytic capacitor) may be applied. In this specification, the electrolyte layer may be read as a solid electrolyte layer, and the electrolytic capacitor may be read as a solid electrolytic capacitor. The electrolyte layer may be a laminate of two or more different electrolyte layers.

[0056] The electrolyte layer is disposed so as to cover at least a part of the dielectric layer. The electrolyte layer may be formed using a manganese compound or a conductive polymer. Examples of the conductive polymer include polypyrrole, polythiophene, polyaniline, and derivatives thereof. These may be used alone or in combination of multiple types. Further, the conductive polymer may be a copolymer of two or more types of monomers. Note that the derivative of the conductive polymer means a polymer having the conductive polymer as a basic skeleton. For example, examples of the derivative of polythiophene include poly(3,4-ethylenedioxythiophene).

[0057] It is preferable that a dopant is added to the conductive polymer. The dopant can be selected according to the conductive polymer, and a known dopant may be used. Examples of the dopant include naphthalenesulfonic acid, p-toluenesulfonic acid, polystyrenesulfonic acid, and salts thereof. An example of the electrolyte layer is formed using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrenesulfonic acid (PSS).

[0058] The electrolyte layer containing the conductive polymer may be formed by polymerizing a raw material monomer on the dielectric layer. Alternatively, it may be formed by applying a liquid containing the conductive polymer (and, if necessary, a dopant) to the dielectric layer and then drying it.

[0059] (Cathode layer) The cathode layer may be a conductive layer formed on the electrolyte layer, for example, a conductive layer formed so as to cover the electrolyte layer. The cathode layer may include a carbon layer formed on the electrolyte layer and a metal paste layer formed on the carbon layer. The carbon layer may be formed of a conductive carbon material such as graphite and a resin. The metal paste layer may be formed of metal particles (for example, silver particles) and a resin, and may be formed of a known silver paste, for example.

[0060] (Conductive member) The cathode layer is connected to the connection part of the cathode lead terminal by a conductive member. That is, the cathode layer (cathode part) is electrically connected to the cathode lead terminal. The conductive member is composed of a material having conductivity. The conductive member may be formed using a material containing metal particles (for example, silver particles) and resin, or may be formed using a known metal paste (for example, silver paste), for example. The conductive member may be formed by curing the metal paste (for example, curing by heating). Note that the conductive member may be composed of a plurality of conductive layers of different types.

[0061] (Exterior resin) The exterior resin is disposed around the capacitor element so that the capacitor element is not exposed on the surface of the electrolytic capacitor. Further, the exterior resin insulates the anode lead terminal and the cathode lead terminal. A known exterior resin used for an electrolytic capacitor may be applied to the exterior resin. For example, the exterior resin may be formed using an insulating resin material used for sealing the capacitor element. Examples of the exterior resin include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester. The exterior resin may contain substances other than resin (such as inorganic fillers).

[0062] (Manufacturing method of electrolytic capacitor) The manufacturing methods of the first to third electrolytic capacitors of the present disclosure are not particularly limited. For example, they may be manufactured by the manufacturing methods described below. An example of the manufacturing method of the first to third electrolytic capacitors of the present disclosure includes a coating step of applying a conductive material (a material that becomes a conductive member) to the plate-like portion and / or the cathode portion of the connection portion of the cathode lead terminal, an adhesion step of adhering the connection portion and the cathode portion via the conductive material, and a step of converting the conductive material into a conductive member. The conductive material can be converted into a conductive member by heating, curing, or the like. When adhering the connection portion and the cathode portion via the conductive material, the conductive material spreads between the side surface of the cathode portion and the side wall of the connection portion. When grooves are formed in the plate-like portion and the side wall of the connection portion, the conductive material is disposed in the grooves so as to connect from the plate-like portion to the side wall. In the coating step, the conductive material may be applied to the plate-like portion and the side wall portion.

[0063] Hereinafter, an example of the electrolytic capacitor of the present disclosure will be specifically described with reference to the drawings. The above-described components can be applied to the components of the electrolytic capacitor in the example described below. Further, the components of the electrolytic capacitor in the example described below can be changed based on the above-described description. Further, the matters described below may be applied to the above-described embodiments. Further, in the embodiments described below, components that are not essential to the electrolytic capacitor of the present disclosure may be omitted.

[0064] (Embodiment 1) In Embodiment 1, an example of the first electrolytic capacitor will be described. A cross-sectional view of the electrolytic capacitor 100 of Embodiment 1 is schematically shown in FIG. 1. Further, a cross-sectional view taken along line II-II in FIG. 1 is shown in FIG. 2. Also, an exploded view when the connection portion 133 of the cathode lead terminal 130 is flattened is shown in FIG. 3A. Note that FIG. 3A is an exploded view when the connection portion 133 is viewed from the side where the groove 133g is formed (the same applies to the following exploded views). A side view of the cathode lead terminal 130 is shown in FIG. 3B. Note that FIG. 3B also shows the positions of the cathode portion 115 and the like.

[0065] The electrolytic capacitor 100 includes a capacitor element 110, an anode lead terminal 120, a cathode lead terminal 130, an exterior resin 101, and a conductive member 141. The capacitor element 110 includes an anode portion 111, a dielectric layer 114, and a cathode portion 115. The anode portion 111 includes an anode wire 112 and an anode body 113. The anode body 113 is a rectangular parallelepiped porous sintered body, and its surface is covered with the dielectric layer 114. A part of the anode wire 112 protrudes from the end face 113e of the anode body 113, and the other part of the anode wire 112 is embedded in the anode body 113. Among the capacitor element 110, the portion excluding the anode wire 112 is rectangular parallelepiped-shaped.

[0066] The cathode portion 115 includes an electrolyte layer 116 disposed so as to cover the dielectric layer 114 (or cover the anode body 113 from another perspective) and a cathode layer 117 formed on the electrolyte layer 116. The cathode layer 117 includes, for example, a carbon layer formed on the electrolyte layer 116 and a metal particle layer formed on the carbon layer. The metal particle layer is a layer formed using, for example, a metal paste.

[0067] The anode lead terminal 120 includes an anode terminal portion 121 and a wire connection portion 122. The anode terminal portion 121 is exposed at the bottom face 100b of the electrolytic capacitor 100. The wire connection portion 122 is connected to the anode terminal portion 121. The wire connection portion 122 is connected to the anode wire 112. That is, the anode lead terminal 120 is electrically connected to the anode portion 111 of the capacitor element 110. Note that the anode lead terminal 120 shown in FIG. 1 is an example, and as long as it functions as the anode lead terminal 120, other shapes may be used.

[0068] The cathode lead terminal 130 includes a cathode terminal portion 131, a connecting portion 132, and a connection portion 133. The cathode terminal portion 131 is exposed at the bottom face 100b of the electrolytic capacitor 100. The connecting portion 132 connects the cathode terminal portion 131 and the connection portion 133. The anode lead terminal 120 and the cathode lead terminal 130 can each be formed by processing a single metal sheet by a known metal processing method.

[0069] Hereinafter, the surface on the side opposite to the bottom surface 100b of the electrolytic capacitor 100 may be referred to as the upper surface 100t of the electrolytic capacitor 100. Note that the bottom surface 100b is the surface on which the anode terminal portion 121 and the cathode terminal portion 131 are exposed.

[0070] The cathode portion 115 has first and second side surfaces 115sa and 115sb, and a bottom surface 115b and an upper surface 115t that connect the first side surface 115sa and the second side surface 115sb. The bottom surface 115b is the surface on the bottom surface 100b side. The upper surface 115t is the surface on the upper surface 100t side. The first and second side surfaces 115sa and 115sb are substantially perpendicular to the end surface 113e.

[0071] The connection portion 133 includes a plate-like portion 133a facing the upper surface 115t of the cathode portion 115 with the conductive member 141 interposed therebetween, and first and second side walls 133sa and 133sb rising from the plate-like portion 133a. The first and second side walls 133sa and 133sb face the first and second side surfaces 115sa and 115sb of the cathode portion 115 with the conductive member 141 interposed therebetween, respectively. The first and second side walls 133sa and 133sb rise substantially vertically from the plate-like portion 133a.

[0072] The conductive member 141 is disposed between the upper surface 115t and the plate-like portion 133a, between the first side surface 115sa and the first side wall 133sa, and between the second side surface 115sb and the second side wall 133sb. That is, the conductive member 141 contacts the upper surface 115t and the plate-like portion 133a and electrically connects them, contacts the first side surface 115sa and the first side wall 133sa and electrically connects them, and contacts the second side surface 115sb and the second side wall 133sb and electrically connects them.

[0073] Referring to FIG. 3A, on the surfaces of the plate-like portion 133a and the side walls 133sa and 133sb that face the cathode portion 115, a plurality of grooves 133g arranged in a stripe shape are formed. Each groove 133g extends from the plate-like portion 133a across the first and second side walls 133sa and 133sb. Each groove 133g extends in a direction perpendicular to the direction D1 in which the anode wire 112 extends.

[0074] In addition, as shown in FIG. 3A, the plurality of grooves 133g can be considered to include a plurality of first grooves 133ga and a plurality of second grooves 133gb. That is, each of the plurality of first grooves 133ga can be considered to be connected to the corresponding groove among the plurality of second grooves 133gb to form one groove 133g. This is the same for all the grooves 133g (for example, the grooves 133g shown in FIGS. 5 and 6) that extend so as to be connected to both the first and second side walls 133sa and 133sb from the plate-like portion 133a. Each of the plurality of first grooves 133ga is formed so as to extend from the plate-like portion 133a across the first side wall 133sa. Each of the plurality of second grooves 133gb is formed so as to extend from the plate-like portion 133a across the second side wall 133sb.

[0075] FIG. 3B shows the heights 133h of the first and second side walls of the connection portion 133 and the height 115h of the side surface 115sa of the cathode portion 115. The height 133h may be within the range described above. FIG. 3B shows the center 113c (the center in the direction D1) of the anode body 113. One end of the connection portion 133 shown in FIG. 3B is located on the side of the end surface 113e rather than the center 113c.

[0076] The conductive member 141 is disposed between the upper surface 115t of the cathode portion 115 and the plate-like portion 133a of the connection portion 133, and between the side surfaces 115sa and 115sb of the cathode portion 115 and the side walls 133sa and 133sb of the connection portion 133, and electrically and physically connects them. Further, in the plurality of grooves 133g, the conductive member 141 is disposed so as to connect from the groove 133g of the plate-like portion 133a to the grooves 133g of the first and second side walls 133sa and 133sb. According to these configurations, the contact area between the cathode portion 115 and the conductive member 141 can be increased, and the ESR can be reduced. Further, according to these configurations, the conductive member 141 can be prevented from protruding from the connection portion 133, so that problems such as a short circuit can be suppressed. Furthermore, the cathode portion 115 and the connection portion 133 (cathode lead terminal 130) can be fixed with a high adhesive force.

[0077] In one example shown in FIGS. 1 to 3B, the cathode lead terminal 130 in which a linear groove 133g is formed is shown. However, the groove 133g formed in the cathode lead terminal 130 may have other shapes. Development views when such a cathode lead terminal 130 is flattened are shown in FIGS. 4 to 6. Even with the cathode lead terminal 130 shown in FIGS. 4 to 6, the above-described effects can be obtained.

[0078] In the connection portion 133 of the cathode lead terminal 130 in FIG. 4, a plurality of grooves 133g are formed. The plurality of grooves 133g include a plurality of first grooves 133ga and a plurality of second grooves 133gb. The cathode lead terminal 130 shown in FIG. 4 is different from the cathode lead terminal 130 shown in FIG. 3 in that the first groove 133ga and the second groove 133gb are not connected. Since other points are the same as those of the cathode lead terminal 130 shown in FIG. 3, overlapping descriptions are omitted. According to the cathode lead terminal 130 shown in FIG. 4, when the conductive member 141 is formed, the material of the conductive member 141 disposed in the portion without the groove 133g is easily moved to the groove 133g and the side walls 133sa and 133sb sides.

[0079] A plurality of grooves 133g are formed in the connection portion 133 of the cathode lead terminal 130 in FIG. 5. In an example shown in FIG. 4, the groove 133g formed in the plate-like portion 133a is a linear groove extending substantially perpendicular to the direction D1 in which the anode wire 112 extends. The grooves 133g formed in the side walls 133sa and 133sb are also linear grooves, but are formed so as to be farther from the end face 113e of the anode body 113 as they are farther from the plate-like portion 133a. All the grooves 133g are connected from the plate-like portion 133a to the side walls 133sa and 133sb.

[0080] According to the configuration of FIG. 5, it becomes easier to guide the material of the conductive member 141 disposed between the side surfaces 115sa and 115sb of the cathode portion 115 and the side walls 133sa and 133sb in a direction away from the end face 113e. As a result, it is possible to suppress the material of the conductive member from protruding to the side of the anode wire 112 protruding from the end face 113e, and prevent a short circuit or the like.

[0081] A plurality of grooves 133g are formed in the connection portion 133 of the cathode lead terminal 130 in FIG. 6. The plurality of grooves 133g include a plurality of grooves 133gc arranged in a stripe shape and a plurality of grooves 133gd arranged in a stripe shape. The plurality of grooves 133gc and the plurality of grooves 133gd are each inclined with respect to a direction perpendicular to the direction D1 in which the anode wire 112 extends.

[0082] The plurality of grooves 133gc and the plurality of grooves 133gd are arranged to intersect each other. The plurality of grooves 133gc and 133gd are each connected from the plate-like portion 133a to the first and second side walls 133sa and 133sb. However, some of the grooves 133gc and some of the grooves 133gd may be connected only to one of the first and second side walls 133sa and 133sb from the plate-like portion 133a.

[0083] FIG. 2 shows an example in which the first and second side walls 133sa and 133sb are substantially perpendicular to the plate-like portion 133a. However, the first and second side walls 133sa and 133sb may widen as they move away from the plate-like portion 133a. A cross-sectional view of an example of the electrolytic capacitor 100 including such a connection portion 133 is shown in FIG. 7. In the connection portion 133 shown in FIG. 7, the angle formed by the first and second side walls 133sa and 133sb and the plate-like portion 133a may be 100° or more.

[0084] A groove 133z may also be formed on the surface of the connection portion 133 opposite to the surface on the cathode portion 115 side. A cross-sectional view of an example of the electrolytic capacitor 100 including the cathode lead terminal 130 in which the groove 133z is formed is shown in FIG. 8. In the electrolytic capacitor 100 of FIG. 8, the exterior resin 101 is disposed in the groove 133z. Thereby, a high anchor effect can be obtained, and the connection portion 133 of the cathode lead terminal 130 can be firmly fixed. Note that the shape and arrangement of the groove 133z are not particularly limited. The groove 133z may have the same shape as the groove 133g described above.

[0085] In Embodiment 1, an example in which the plate-like portion 133a of the connection portion 133 faces the upper surface 115t of the cathode portion 115 with the conductive member 141 interposed therebetween has been described. However, the plate-like portion 133a may be arranged to face the bottom surface 115b of the cathode portion 115 with the conductive member 141 interposed therebetween. In that case, the first and second side walls 133sa and 133sb extend from the plate-like portion 133a toward the upper surface 100t.

[0086] An example of a method for manufacturing the electrolytic capacitor 100 will be described below. First, the capacitor element 110, the anode lead terminal 120, and the cathode lead terminal 130 are prepared. The method for manufacturing the capacitor element 110 is not particularly limited, and it can be manufactured by a known method. The anode lead terminal 120 and the cathode lead terminal 130 can be formed by a known metal processing method.

[0087] Next, connect the anode wire 112 and the anode lead terminal 120, and connect the cathode layer 117 and the cathode lead terminal 130. The anode wire 112 and the anode lead terminal 120 may be connected, for example, by welding the tip of the anode lead terminal 120 and the wire connection portion 122. The connection between the cathode layer 117 and the cathode lead terminal 130 can be performed, for example, by the following method. First, apply a conductive material (for example, a metal paste) that becomes the conductive member 141 to the connection portion 133 (for example, the plate-shaped portion 133a) of the cathode lead terminal 130 and / or the surface of the cathode portion 115 (cathode layer 117) of the capacitor element 110. Usually, the conductive material is applied to either the plate-shaped portion 133a or the cathode portion 115. Next, after bonding the connection portion 133 and the cathode portion 115 via the conductive material, cure the conductive material to form the conductive member 141. In this way, the cathode portion 115 and the cathode lead terminal 130 can be connected by the conductive member 141.

[0088] Next, encapsulate the capacitor element with the outer resin 101. The encapsulation process can be carried out by a known method. In this way, the electrolytic capacitor 100 can be manufactured. Note that other electrolytic capacitors of the present disclosure can also be manufactured by a similar manufacturing method.

[0089] (Embodiment 2) In Embodiment 2, an example of the second electrolytic capacitor described above will be described. A cross-sectional view of the electrolytic capacitor 200 of Embodiment 2 is schematically shown in FIG. 9. Further, a cross-sectional view taken along line X-X in FIG. 9 is shown in FIG. 10. An exploded view when the connection portion 133 of the cathode lead terminal 130 is flattened is shown in FIG. 11A. A top view and a side view of the cathode lead terminal 130 are shown in FIGS. 11B and 11C, respectively. Note that FIGS. 11B and 11C also show the positions of the cathode portion 115 and the like.

[0090] The electrolytic capacitor 200 includes a capacitor element 110, an anode lead terminal 120, a cathode lead terminal 130, an exterior resin 101, and a conductive member 141. The capacitor element 110 includes an anode portion 111, a dielectric layer 114, and a cathode portion 115. The anode portion 111 includes an anode body 113 and an anode wire 112. The anode body 113 is a rectangular parallelepiped-shaped porous sintered body, and the dielectric layer 114 is formed on the surface. A part of the anode wire 112 protrudes from the end face 113e of the anode body 113, and the other part of the anode wire 112 is embedded in the anode body 113.

[0091] The cathode portion 115 includes an electrolyte layer 116 disposed so as to cover the dielectric layer 114 (anode body 113), and a cathode layer 117 formed on the electrolyte layer 116. The cathode layer 117 includes, for example, a carbon layer formed on the electrolyte layer 116 and a metal particle layer formed on the carbon layer. The metal particle layer is a layer formed using, for example, a metal paste.

[0092] The anode lead terminal 120 includes an anode terminal portion 121 and a wire connection portion 122. The anode terminal portion 121 is exposed at the bottom surface 100b of the electrolytic capacitor 200. The wire connection portion 122 is connected to the anode terminal portion 121. The wire connection portion 122 is connected to the anode wire 112. That is, the anode lead terminal 120 is electrically connected to the anode portion 111 of the capacitor element 110. Note that the anode lead terminal 120 shown in FIG. 9 is an example, and other shapes may be used as long as the function of the anode lead terminal 120 is achieved.

[0093] The cathode lead terminal 130 includes a cathode terminal portion 131, a connecting portion 132, and a connection portion 133. The cathode terminal portion 131 is exposed at the bottom surface 100b of the electrolytic capacitor 200. The connecting portion 132 connects the cathode terminal portion 131 and the connection portion 133. The anode lead terminal 120 and the cathode lead terminal 130 can each be formed by processing a single metal sheet by a known metal processing method.

[0094] Hereinafter, the surface on the side opposite to the bottom surface 100b of the electrolytic capacitor 200 may be referred to as the upper surface 100t of the electrolytic capacitor 200. Note that the bottom surface 100b is the surface on which the anode terminal portion 121 and the cathode terminal portion 131 are exposed.

[0095] The cathode portion 115 has two side surfaces 115s, a bottom surface 115b connecting the two side surfaces 115s, and an upper surface 115t. The bottom surface 115b is the surface on the bottom surface 100b side. The upper surface 115t is the surface on the upper surface 100t side. The two side surfaces 115s are substantially perpendicular to the end surface 113e.

[0096] The connection portion 133 includes a plate-like portion 133a facing the bottom surface 115b with the conductive member 141 interposed therebetween, and two side walls 133s rising from the plate-like portion 133a. The two side walls 133s respectively face the two side surfaces 115s of the cathode portion 115 with the conductive member 141 interposed therebetween. The two side walls 133s rise substantially vertically from the plate-like portion 133a.

[0097] The conductive member 141 is disposed between the bottom surface 115b and the plate-like portion 133a, and between the two side surfaces 115s and the two side walls 133s facing the respective side surfaces. That is, the conductive member 141 contacts the bottom surface 115b and the plate-like portion 133a and electrically connects them. Further, the conductive member 141 contacts the two side surfaces 115s and the two side walls 133s and electrically connects them.

[0098] FIG. 11A shows the width W of the plate-like portion 133a. The width W is the length of the plate-like portion 133a in a direction perpendicular to the direction D1. The width W of the plate-like portion 133a becomes wider as it moves away from the end surface 113e of the anode body 113. The plate-like portion 133a shown in FIG. 11A has a trapezoid shape with equal legs. And two side walls 133s rise from the two leg portions of the trapezoid with equal legs. The side wall 133s shown in FIG. 11A is rectangular.

[0099] FIG. 11B shows the angle α1 formed between the direction in which the side wall 133s extends and the side surface 115s (more specifically, the surface including the side surface 115s) of the cathode portion 115. FIG. 11C shows the distance X1 between the end portion (end edge) 133ae on the end surface 113e side of the plate-like portion 133a and the end surface 113e, which is the distance in the direction D1 in which the anode wire 112 extends, and the distance Y1 between the end portion 133se (end edge) on the end surface 113e side of the side wall 133s and the end surface 113e, which is the distance in the direction D1. Further, FIG. 11C also shows the length L1 of the anode body 113 in the direction D1. Further, FIG. 11C also shows the center 113c of the anode body 113 in the direction D1.

[0100] The distance X1, the distance Y1, and the length L1 may be within the ranges described above. Both the end portion 133ae of the plate-like portion 133a and the end portion 133se of the side wall 133s are located closer to the end surface 113e than the center 113c of the anode body 113.

[0101] In the electrolytic capacitor 200, the volume between the cathode portion 115 and the two side walls 133s of the connection portion 133 increases as it moves away from the end surface 113e of the anode body 113. From another perspective, the area between the cathode portion 115 and the side wall 133s in a cross-section perpendicular to the direction D1 increases as it moves away from the end surface 113e of the anode body 113. According to these configurations, when adhering the cathode portion 115 and the connection portion 133 using the material (conductive material) of the conductive member 141, it is easy to guide the conductive material in the direction away from the end surface 113e. Therefore, the above-described effects can be obtained.

[0102] (Embodiment 3) In Embodiment 3, another example of the second electrolytic capacitor will be described. Since the electrolytic capacitor 200a of Embodiment 3 is substantially different from the electrolytic capacitor 200 of Embodiment 2 only in the shape of the connection portion 133, duplicate explanations will be omitted.

[0103] Since the cross-sectional view of the electrolytic capacitor 200a of Embodiment 3 along the direction D1 is the same as the cross-sectional view of the electrolytic capacitor 200 shown in FIG. 9, the illustration thereof is omitted. FIG. 12 shows a cross-sectional view of the electrolytic capacitor 200a at a position corresponding to the line X-X in FIG. 9. FIG. 13A shows a developed view when the connection portion 133 of the cathode lead terminal 130 of Embodiment 3 is flattened. FIG. 13B shows a top view of the cathode lead terminal 130. FIG. 13B also shows the position of the cathode portion 115. FIG. 13B also shows an angle α2 formed between the direction in which the upper side of the side wall 133s of the connection portion 133 extends and the side surface 115s of the cathode portion 115 (more specifically, the surface including the side surface 115s). Note that since the side view of the cathode lead terminal 130 of Embodiment 3 is the same as that in FIG. 11C, the illustration thereof is omitted.

[0104] In Embodiment 3, the plate-like portion 133a of the connection portion 133 has a rectangular shape. The distance between each of the two side walls 133s of the connection portion 133 and the cathode portion 115 increases as the distance from the end face 113e of the anode body 113 increases, and also increases as the distance from the plate-like portion 133a increases.

[0105] Also in the electrolytic capacitor 200a of Embodiment 3, the volume between the cathode portion 115 and the two side walls 133s of the connection portion increases as the distance from the end face 113e of the anode body 113 increases. According to this configuration, the above-described effects can be obtained.

[0106] (Embodiment 4) In Embodiment 4, an example of a third electrolytic capacitor will be described. Since the electrolytic capacitor 300 of Embodiment 4 is substantially different from the electrolytic capacitor 200 of Embodiment 2 only in the shape of the connection portion 133, duplicate explanations are omitted.

[0107] FIG. 14 shows a cross-sectional view of the electrolytic capacitor 300. Note that FIG. 14 is substantially the same as FIG. 9. FIG. 15 shows a cross-sectional view at the line XV-XV in FIG. 14. FIG. 16A shows a developed view when the connection portion 133 of the electrolytic capacitor 300 is flattened. FIGS. 16B and 16C show a top view and a side view of the connection portion 133, respectively.

[0108] The cathode lead terminal 130 of the electrolytic capacitor 300 includes a connection portion 133 connected to the cathode portion 115 via a conductive member 141. The connection portion 133 includes a plate-shaped portion 133a facing the bottom surface 115b of the cathode portion 115 with the conductive member 141 interposed therebetween, and two side walls 133s rising substantially perpendicularly from the plate-shaped portion 133a. The two side walls 133s face two side surfaces 115s of the cathode portion 115, respectively.

[0109] The conductive member 141 is disposed between the bottom surface 115b and the plate-shaped portion 133a, and between the two side surfaces 115s and the two side walls 133s. That is, the conductive member 141 contacts the bottom surface 115b and the plate-shaped portion 133a and electrically connects them, and contacts the two side surfaces 115s and the two side walls 133s and electrically connects them.

[0110] FIG. 16C shows a distance X2 between an end portion (end edge) 133ae of the plate-shaped portion 133a on the end face 113e side and the end face 113e, which is a distance in the direction D2 in which the anode wire extends. Further, FIG. 16C shows a distance Y2 between an end portion (end edge) 133se of the two side walls 133s on the end face 113e side and the end face 113e, which is a distance in the direction D2. Further, FIG. 16C shows a length L2 of the anode body 113 in the direction D2. Further, FIG. 16C shows a center 113c of the anode body 113 in the direction D2.

[0111] The relationship among the distance X2, the distance Y2, and the length L2 may be within the range described above. As shown in FIG. 16C, the end portions 133se of the two side walls 133s of the connection portion 133 on the end face 113e side are farther from the end face 113e than the end portion 133ae of the plate-shaped portion 133a on the end face 113e side. That is, the distance Y2 is larger than the distance X2.

[0112] In order to increase the area of the conductive member 141, it is necessary to apply a large amount of the conductive material, which is the material of the conductive member 141. On the other hand, in that case, there is a possibility that a part of the conductive material may protrude from the connection part 133. According to the above configuration, the conductive material is likely to protrude from the end part 133se. Since the end part 133se is located at a position away from the anode wire 112, even when the conductive material protrudes from the connection part 133, it is possible to suppress the conductive material from reaching the anode wire 112. In order to enhance this effect, when arranging the conductive material, it may be arranged at a position away from the end face 113e. For example, the conductive material may be arranged at a position farther from the end face 113e than the center 113c. Alternatively, the conductive material may be arranged at a position farther from the end face 113e than the end part 133se.

[0113] The end part 133ae and the end part 133se are each located on the end face 113e side with respect to the center 113c. According to this configuration, it is possible to increase the area connected by the conductive member 141. Even in this case, as described above, it is possible to suppress the conductive material for forming the conductive member 141 from reaching the anode wire 112.

[0114] In Embodiments 2 to 4, an example in which the plate-like part 133a of the connection part 133 faces the bottom face 115b of the cathode part 115 with the conductive member 141 interposed therebetween has been described. However, the plate-like part 133a may be arranged so as to face the upper face 115t of the cathode part 115 with the conductive member 141 interposed therebetween. In that case, the two side walls 133s extend from the plate-like part 133a toward the bottom face 100b.

[0115] In the electrolytic capacitor 200 of Embodiment 2 or Embodiment 3, grooves described in Embodiment 1 may be formed in the connection part 133. In that case, as described in Embodiment 4, the end parts on the end face 113e side of the two side walls 133s of the connection part 133 may be farther from the end face 113e than the end parts on the end face 113e side of the plate-like part 133a.

[0116] In the electrolytic capacitor of Embodiment 1 or 2, as described in Embodiment 4, the ends of the two side walls 133s of the connecting portion 133 on the end face 113e side may be farther from the end face 113e than the ends of the plate-like portion 133a on the end face 113e side.

Industrial Applicability

[0117] The present disclosure can be applied to an electrolytic capacitor. Although the present invention has been described with respect to the presently preferred embodiments, such disclosure should not be construed in a limiting sense. Various modifications and alterations will no doubt become apparent to those skilled in the art in the technology field to which the present invention pertains upon reading the above disclosure. Accordingly, the appended claims are to be construed as encompassing all modifications and alterations without departing from the true spirit and scope of the present invention.

Explanation of Signs

[0118] 100, 200, 200a, 300: Electrolytic capacitor 101: Exterior resin 110: Capacitor element 112: Anode wire 113: Anode body 113e: End face 114: Dielectric layer 115: Cathode portion 115b: Bottom face 115sa: First side face 115sb: Second side face 115t: Top face 120: Anode lead terminal 130: Cathode lead terminal 13 3: Connecting portion 133 a: Plate-like portion 133g, 133z: Groove 133ga: First groove 133gb: Second groove 133s: Side wall 133sa: First side wall 133sb: Second side wall 141: Conductive member

Claims

1. An electrolytic capacitor including a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element, wherein the capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on a surface thereof, an anode wire protruding from an end surface of the anode body, and a cathode portion disposed adjacent to the dielectric layer, the cathode portion has first and second side surfaces, and a bottom surface and a top surface connecting the first and second side surfaces, the cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member, the connection portion includes a plate-like portion facing one of the bottom surface and the top surface with the conductive member interposed therebetween, and first and second side walls rising from the plate-like portion and facing the first and second side surfaces respectively, a plurality of grooves are formed on surfaces of the plate-like portion and the first and second side walls on the cathode portion side, the plurality of grooves include a plurality of first grooves formed to connect from the plate-like portion to the first side wall, and a plurality of second grooves formed to connect from the plate-like portion to the second side wall, the conductive member is disposed between the one surface and the plate-like portion, between the first side surface and the first side wall, and between the second side surface and the second side wall, an electrolytic capacitor in which a volume between the cathode portion and the first side wall and a volume between the cathode portion and the second side wall each increase as they are away from the end surface.

2. the conductive member is disposed in the first groove so as to connect from the plate-like portion to the first side wall, the conductive member is disposed in the second groove so as to connect from the plate-like portion to the second side wall, the electrolytic capacitor according to claim 1.

3. each of the plurality of first grooves connects to a corresponding groove among the plurality of second grooves to form one groove, the plurality of grooves connect from the plate-like portion to the first and second side walls, the electrolytic capacitor according to claim 1 or 2.

4. each of the plurality of grooves extends in a direction substantially perpendicular to a direction in which the anode wire extends, the electrolytic capacitor according to any one of claims 1 to 3.

5. The electrolytic capacitor according to any one of claims 1 to 3, wherein among the plurality of grooves, the grooves formed in the first and second side walls are each formed so as to be farther from the end face as they are farther from the plate-like portion.

6. Grooves are also formed on the surface of the plate-like portion and the surfaces of the first and second side walls that are opposite to the surface on the cathode portion side. The electrolytic capacitor according to any one of claims 1 to 5, wherein the exterior resin is disposed in the grooves on the opposite surface.

7. The electrolytic capacitor according to any one of claims 1 to 6, wherein the end of the first side wall on the end face side and the end of the second side wall on the end face side are each farther from the end face than the end of the plate-like portion on the end face side.

8. An electrolytic capacitor including a capacitor element, an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, a conductive member, and an exterior resin disposed around the capacitor element, The capacitor element includes an anode body that is a porous sintered body having a dielectric layer formed on its surface, an anode wire protruding from an end face of the anode body, and a cathode portion disposed so as to surround the anode body. The cathode portion has two side surfaces, and a bottom surface and an upper surface connecting the two side surfaces. The cathode lead terminal includes a connection portion connected to the cathode portion via the conductive member. The connection portion includes a plate-like portion facing one of the bottom surface and the upper surface with the conductive member interposed therebetween, and two side walls rising from the plate-like portion and facing the two side surfaces respectively. The conductive member is disposed between the one surface and the plate-like portion, and between the two side surfaces and the two side walls facing the two side surfaces. The electrolytic capacitor in which the volume between the cathode portion and the two side walls increases as it is farther from the end face.

9. The electrolytic capacitor according to claim 8, wherein the width of the plate-like portion widens as it is farther from the end face, at least in a portion where it is connected to the two side walls.

10. The plate-like portion is rectangular. The electrolytic capacitor according to claim 8, wherein the distance between each of the two side walls and the cathode portion increases as the distance from the end face and the distance from the plate-like portion increase.

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