Electrolytic capacitors

Abstract

To improve the reliability of electrolytic capacitors. [Solution] The electrolytic capacitor comprises a capacitor element having an anode portion and a cathode portion, an anode lead frame electrically connected to the anode portion, a cathode lead frame electrically connected to the cathode portion, and an outer casing covering the capacitor element. The anode portion has an anode body and an anode wire extending from the mounting surface of the anode body. The anode lead frame has a first portion exposed from a first main surface facing the mounting surface of the outer casing and extending along the first main surface, and a second portion bent from the first portion and embedded in the outer casing. The second portion has a projection that protrudes in a direction intersecting the direction in which the anode wire extends.

Description

[Technical Field]

[0001] This invention relates to an electrolytic capacitor. [Background technology]

[0002] Electrolytic capacitors are used in a variety of electronic devices because they have a low equivalent series resistance (ESR) and excellent frequency characteristics. An electrolytic capacitor typically comprises a capacitor element with an anode and a cathode, an anode lead frame electrically connected to the anode, and a cathode lead frame electrically connected to the cathode. The capacitor element is usually sealed by an outer casing.

[0003] Patent Document 1 proposes a bottom-electrode type solid electrolytic capacitor comprising a capacitor element from which an anode lead wire is led out, an anode terminal connected to the anode lead wire and exposed on the bottom and end faces, a cathode terminal connected to the cathode of the capacitor element via a conductive adhesive and exposed on the bottom and end faces, and an insulating outer resin covering the entire assembly, wherein the anode terminal and cathode terminal have a sleeper-like raised portion processed from the base material of the lead frame and raised by drawing, coining, or rolling, and a tip extension portion is formed at the tip on the bottom center side of the cathode terminal that is connected to the cathode layer of the capacitor element, and a step is formed between the back surface of the tip extension portion on the bottom side of the tip extension portion and the bottom exposed surface of the cathode terminal, and a stepped shape is formed at the gradient boundary portion connecting the back surface of the tip extension portion and the bottom exposed surface. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2008-53513 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In Patent Document 1, the upper surface of the cathode terminal extension portion of the cathode terminal is processed with embossing, chrysanthemum patterns, star patterns, etc., to improve connection strength (paragraph

[0015] ), thereby strengthening the connection between the cathode terminal and the capacitor element.

[0006] On the other hand, the connection strength between the anode terminal and the capacitor element is ensured by the welded portion between the anode terminal and the anode lead wire (anode wire) and the outer resin (outer casing).

[0007] However, the connection between the anode terminal and the capacitor element is susceptible to thermal stress in the lateral direction (the direction in which the anode wire extends) due to the difference in thermal expansion coefficients between the anode terminal, anode wire, and outer casing. Therefore, when the anode terminal and anode wire expand and contract due to changes in ambient temperature, delamination or defects may occur in the welded area. If delamination or defects occur in the welded area, the performance of the electrolytic capacitor will deteriorate, such as an increase in the ESR of the electrolytic capacitor. [Means for solving the problem]

[0008] In view of the above issues, one aspect of the present disclosure relates to an electrolytic capacitor comprising: at least one capacitor element having an anode portion and a cathode portion; an anode lead frame electrically connected to the anode portion; a cathode lead frame electrically connected to the cathode portion; and an outer casing covering the capacitor element with a portion of the anode lead frame and the cathode lead frame exposed, wherein the anode portion comprises an anode body and an anode wire extending from the mounting surface of the anode body; the anode lead frame comprises a first portion exposed from a first main surface of the outer casing facing the mounting surface and extending along the first main surface, and a second portion bent from the first portion and embedded in the outer casing, wherein the second portion has a projection that protrudes in a direction intersecting the direction of extension of the anode wire. [Effects of the Invention]

[0009] According to this disclosure, the reliability of electrolytic capacitors is improved. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing an electrolytic capacitor according to one embodiment of the present disclosure. [Figure 2] This is a schematic cross-sectional view of a capacitor element used in an electrolytic capacitor according to one embodiment of the present disclosure. [Figure 3] This is a schematic cross-sectional view of an electrolytic capacitor, showing an enlarged view of the connection point between the anode wire and the anode lead frame, illustrating the structure of the protrusions. [Figure 4] This is a schematic top view of an electrolytic capacitor, showing an enlarged view of the connection point between the anode wire and the anode lead frame, illustrating the structure of the protrusions. [Modes for carrying out the invention]

[0011] Examples of embodiments relating to this disclosure are described below. While examples of embodiments relating to this disclosure are given below, this 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 this disclosure are achieved. In this specification, when referring to a "range of numerical values ​​A to numerical values ​​B," the range includes numerical values ​​A and B, and can be interpreted as "greater than or equal to numerical value A and less than or equal to numerical value B." In the following description, when exemplified lower and upper limits of numerical values ​​relating to specific physical properties or conditions, any combination of the exemplified lower limits and exemplified upper limits may be used, as long as the lower limit is not greater than or equal to the upper limit. When multiple materials are exemplified, one may be selected and used alone, or two or more may be used in combination.

[0012] Furthermore, this disclosure encompasses any combination of matters described in two or more claims, which may be arbitrarily selected from the multiple claims set forth in the attached claims. In other words, any combination of matters described in two or more claims, which may be arbitrarily selected from the multiple claims set forth in the attached claims, is possible, provided that no technical inconsistency arises.

[0013] The electrolytic capacitor according to this embodiment includes at least one capacitor element having an anode portion and a cathode portion, an anode lead frame electrically connected to the anode portion, a cathode lead frame electrically connected to the cathode portion, and an exterior body. The exterior body covers the capacitor element in a state where a part of the anode lead frame and the cathode lead frame is exposed. The anode portion has an anode body and an anode wire extending from the implantation surface of the anode body.

[0014] The outer surface of the exterior body has a first main surface. The first main surface is a surface facing the implantation surface of the anode body, and the anode wire extends from the implantation surface toward the first main surface. The outer surface of the exterior body may also have a second main surface and a third main surface that share a side with the first surface. The second main surface and the third main surface face each other. The second main surface may be a surface corresponding to the bottom surface of the electrolytic capacitor. The third main surface may be a surface corresponding to the top surface of the electrolytic capacitor.

[0015] The electrolytic capacitor usually has a schematic rectangular parallelepiped shape. In this case, the schematic shape of the exterior body is also a rectangular parallelepiped, and the first main surface to the third main surface are three surfaces of the rectangular parallelepiped. That is, the first main surface to the third main surface of the exterior body are usually, among the six surfaces of the outer surface of the exterior body formed to form a substantially rectangular parallelepiped, two surfaces facing each other and one surface connecting the two facing surfaces. However, these surfaces do not necessarily have to be flat, and may have a curved surface shape, have some irregularities, and / or be formed by a plurality of bent planes. The angle formed by the first main surface and the second main surface, and the angle formed by the second main surface and the third main surface may each be a right angle, an acute angle, or an obtuse angle. That is, a certain main surface may be inclined with respect to another main surface.

[0016] The anode lead frame has a first portion and a second portion bent from the first portion. The first portion is exposed from the first main surface of the exterior body facing the implantation surface and extends along the first main surface from the exposed position. The second portion is embedded in the exterior body in a state bent from the first portion. The second portion usually extends in a direction intersecting the first main surface of the exterior body substantially parallel to the second main surface toward the implantation surface of the anode wire.

[0017] Furthermore, the phrase "extending along the first main surface" for the lead frame portion is not limited to cases where the portion extends parallel to the first main surface, but may also include cases where it extends at a slight angle to the first main surface. Similarly, the phrase is not limited to cases where the portion extends exposed from the first main surface, but may also include cases where it extends within the exterior of the casing, near the first main surface. The same applies to the phrase "extending along the second or third main surface" for the lead frame portion.

[0018] The second part has a projection that protrudes in a direction intersecting the extension direction of the anode wire.

[0019] The protrusions are positioned to intersect the direction in which the anode wire extends, thereby suppressing thermal expansion of the anode lead frame (second portion) in the direction in which the anode wire extends. This keeps the relative position of the second portion with respect to the anode wire constant even when the electrolytic capacitor is subjected to changes in ambient temperature, and prevents delamination or defects from occurring at the joint between the second portion and the anode wire.

[0020] The projection may protrude in a direction that intersects the second main surface and the direction in which the anode wire extends, or it may protrude along the second main surface and in a direction that intersects the direction in which the anode wire extends.

[0021] As an example of a projection that intersects the second main surface and protrudes in a direction intersecting the extension direction of the anode wire, the second portion may have a third portion that bends from the first portion and extends toward the anode wire, and a fourth portion that rises from the third portion, intersects with the third portion, and protrudes so as to intersect with the mounting surface, which is the second main surface of the outer casing. In this case, the fourth portion constitutes the projection. The fourth portion may rise from the third portion on the side of the joint surface between the anode wire and the second portion (third portion), or it may rise from the third portion on the side opposite to the joint surface between the anode wire and the second portion (third portion).

[0022] At least a portion of the anode wire overlaps with the third portion. In the overlapping portion of the anode wire, the anode wire comes into contact with the third portion of the anode lead frame, forming a joint between the anode wire and the third portion. To suppress delamination or defects at the joint, the position where the fourth portion rises from the third portion is preferably between the anode body side end of the overlapping portion of the anode wire and the extended end of the anode wire in the direction of extension of the anode wire. More preferably, the fourth portion rises from the third portion at the position of the anode body side end of the overlapping portion in the direction of extension of the anode wire.

[0023] As an example of a projection that extends along the second main surface and in a direction intersecting the direction of extension of the anode wire, the second portion may have a third portion that bends from the first portion and extends toward the anode wire, and a fifth portion that protrudes from the third portion in a direction away from the anode wire along the surface direction of the third portion. In this case, the fifth portion constitutes the projection.

[0024] The projection may have a rising portion that protrudes in a first direction intersecting the extension direction of the anode wire, and a folded portion that bends from the rising portion and extends in a direction intersecting the first direction. This makes it easier to suppress thermal expansion of the anode lead frame (second portion) in the extension direction of the anode wire, makes it easier to maintain a constant relative position of the second portion with respect to the anode wire, and enhances the effect of suppressing delamination or defects at the joint between the second portion and the anode wire.

[0025] In the above example, the fourth and fifth portions include rising portions. The second portion may have a sixth portion as a folded portion that bends from the fourth portion and extends in a direction intersecting the first main surface. The second portion may have a sixth portion as a folded portion that bends from the fifth portion and extends in a direction intersecting the first main surface. The folded portion may extend toward the anode wire or toward the anode wire, either way is acceptable.

[0026] The joint between the anode wire and the second part may form a protrusion. For example, when the anode wire is joined to the second part by resistance welding, the molten part of the anode wire may be formed in a columnar shape near the end of the anode body side in the overlapping part. Usually, the welding conditions are set and adjusted so that a columnar molten part does not occur. However, in the present disclosure, by performing welding under conditions that deliberately leave a columnar molten part, the molten part can be used as the above-mentioned protrusion to suppress the occurrence of peeling or defects in the joint part due to thermal stress.

[0027] That is, the protrusion may include a welding mark at the joint between the anode wire and the second part.

[0028] The protruding height of the protrusion is, for example, 1 time or more and 10 times or less the thickness of the anode lead frame (second part), preferably 2 times or more and 5 times or less, more preferably 3 times or more and 5 times or less.

[0029] The linear expansion coefficient α of the anode wire A and the linear expansion coefficient α of the anode lead frame B and the linear expansion coefficient α of the exterior body C satisfy α A < α C < α B It may satisfy.

[0030] Normally, the linear expansion coefficient α of the anode wire A is smaller than the linear expansion coefficient α of the anode lead frame B , and α B > α A . As a result, in the extending direction of the anode wire, the elongation due to the thermal expansion of the anode lead frame is larger than the elongation of the anode wire, and thermal stress is applied to the joint position between the second part of the anode lead frame and the anode wire. When the linear expansion coefficient α of the exterior body C is between α A and α B , the exterior body has an effect of relaxing the thermal stress at the joint position between the anode wire and the second part of the anode lead frame.

[0031] Hereinafter, an electrolytic capacitor according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a schematic cross-sectional view showing an electrolytic capacitor 100 according to one embodiment of the present invention. Figure 2 is a schematic cross-sectional view of a capacitor element 10 used in the electrolytic capacitor 100.

[0032] The electrolytic capacitor 100 comprises a capacitor element 10 having an anode portion 6 and a cathode portion 7, an anode lead frame 20 electrically connected to the anode portion 6, a cathode lead frame 25 electrically connected to the cathode portion 7, and an outer casing 30. The outer casing 30 covers the capacitor element 10 with a portion of the anode lead frame 20 and the cathode lead frame 25 exposed. The anode portion 6 has an anode body 1 and an anode wire 2 extending from the anode body 1, and the anode wire 2 is joined to the anode lead frame 20.

[0033] The outer surface of the outer casing 30 has a first main surface S1, a second main surface S2 and a third main surface S3 that share one side with the first main surface S1, and a fourth main surface S4 that shares one side with each of the second main surface S2 and the third main surface S3 (see Figure 2). The first main surface S1 is the surface facing the mounting surface 1P on which the anode wire 2 is mounted in the anode body 1. The anode wire 2 extends from the mounting surface toward the first main surface S1. The second main surface S2 and the third main surface S3 face each other. The second main surface S2 is the surface corresponding to the bottom surface of the electrolytic capacitor 100, and the third main surface S3 is the surface corresponding to the top surface of the electrolytic capacitor 100.

[0034] The capacitor element 10 comprises an anode portion 6 and a cathode portion 7. The anode portion 6 has an anode body 1 with a dielectric layer 3 and an anode wire 2. The cathode portion 7 has a solid electrolyte layer 4 formed on the dielectric layer 3 and a cathode layer 5 covering the surface of the solid electrolyte layer 4. The anode wire 2 is embedded in the interior of the anode body 1 from one side (the mounting surface) of the anode body 1, with a portion of it extending from the aforementioned side of the anode body 1.

[0035] The anode lead frame 20 has a first portion 21 and a second portion 22 that is bent from the first portion 21. The first portion 21 is exposed from the first main surface S1 of the outer casing 30 and extends along the first main surface S1 from the exposed position. The second portion 22 is bent from the first portion 21 and is embedded in the outer casing 30 in the bent state from the first portion. The second portion 22 extends in a direction intersecting the first main surface S1 of the outer casing 30, substantially parallel to the second main surface, and extends toward the planting surface 1P.

[0036] The second part 22 is joined to the anode wire 2 by a welding method such as resistance welding, forming a welded joint 23.

[0037] The first part 21 extends along the first main surface S1 on the outer surface of the casing 30, and then bends and extends along the second main surface S2. The portion of the first part 21 that bends and extends along the second main surface S2 constitutes a connection terminal (anode terminal) for the external circuit.

[0038] A portion of the second part 22 is bent further away from the anode wire 2 within the outer casing 30, and a projection is formed that protrudes in a direction intersecting the direction of extension of the anode wire. The projection suppresses thermal expansion of the second part in the direction of extension of the anode wire when the electrolytic capacitor is subjected to changes in ambient temperature (temperature rise), and prevents delamination or defects from occurring at the joint 23 between the second part 22 and the anode wire 2.

[0039] In the example shown in Figure 1, the second portion 22 has a third portion 22A that bends from the first portion 21 and extends toward the anode wire, and a fourth portion 22B that rises from the third portion 22A and protrudes so as to intersect with the third portion 22A and the mounting surface which is the second main surface of the casing. The fourth portion 22B constitutes the projection.

[0040] The protrusion may be a welding mark at the joint between the anode wire 2 and the second portion 22.

[0041] The cathode lead frame 25 has a first portion 26 and a second portion 27 bent from the first portion 26. The first portion 26 is exposed from a fourth main surface S4 facing the first main surface S1 of the housing 30 and extends along the fourth main surface S4 from the exposed position. The second portion 27 is embedded in the housing 30 in a bent state from the first portion 26.

[0042] The second portion 27 extends substantially parallel to the third main surface S3 while bending within the outer casing 30, and is electrically connected to the cathode portion of the capacitor element 10 on the third main surface S3 side. The second portion 27 is electrically connected to the cathode portion 7 via a conductive adhesive layer (e.g., silver paste) 29 on the surface of the cathode portion facing the third main surface S3.

[0043] The first part 26 extends along the fourth main surface S4 on the outer surface of the casing 30, and then bends and extends along the second main surface S2. The portion of the first part 26 that bends and extends along the second main surface S2 constitutes a connection terminal (cathode terminal) for the external circuit.

[0044] Figures 3 and 4 show other examples of projections 24 that protrude in a direction intersecting the extension direction of the anode wire 2. In the example in Figure 3, projections 24A to 24D protrude in a direction intersecting the second main surface S2 and the third main surface S3. Figure 3, like Figure 1, is a schematic cross-sectional view of the electrolytic capacitor in a plane perpendicular to the first main surface S1 and the second main surface S2, and shows a magnified view of the connection between the anode wire 2 and the anode lead frame 20.

[0045] The third portion 22A and the rising position of the fourth portion 22B (projection) rising from the third portion 22A are not particularly limited, but should be located close enough to the joint between the anode wire and the third portion 22A. The rising position should be between the end of the anode body 1 at the portion (joint) where the anode wire 2 overlaps with the third portion 22A, and the extended end of the anode wire 2, in the direction of extension of the anode wire.

[0046] The rising position of the fourth portion 22B may be at the end X on the anode body 1 side of the portion (joint) that overlaps with the third portion 22A of the anode wire 2 in the direction of extension of the anode wire, as shown by projection 24A in Figure 3; it may be at the position of the extended end Y of the anode wire 2 in the direction of extension of the anode wire, as shown by projection 24B or 24C; or it may be at a position on the first portion 21 side of the extended end Y of the anode wire 2 in the direction of extension of the anode wire, as shown by projection 24D.

[0047] The fourth part 22B may rise from the third part on the opposite side of the joint surface between the anode wire 2 and the third part 22A, as shown by the protrusions 24A and 24B in Figure 3, or it may rise from the third part on the side of the joint surface between the anode wire 2 and the third part, as shown by the protrusions 24C and 24D.

[0048] Furthermore, as shown in the projection 24A of Figure 3, the projection may be composed of a rising portion (fourth portion 22B) that protrudes in a first direction intersecting the extension direction of the anode wire, and a folded portion 22D that bends from the rising portion and extends in a direction intersecting the first direction. The folded portion 22D may intersect the first main surface S1 and extend along the second main surface S2.

[0049] The protrusions 24A to 24D can each be formed by folding a portion of the second part of the anode lead frame in a mountain or valley fold and overlapping them.

[0050] In the example shown in Figure 4, the protrusions 24E and 24F project in a direction along the second main surface S2 or the third main surface S3. Figure 4 is a schematic top view of an electrolytic capacitor as seen from the side of the third main surface S3, with the casing 30 omitted and the connection portion between the anode wire 2 and the anode lead frame 20 shown in enlargement.

[0051] The second portion 22 of the anode lead frame 20 may have a third portion 22A that bends from the first portion 21 and extends toward the anode wire 2, and a fifth portion 22C that protrudes from the third portion in a direction away from the anode wire 2 along the planar direction of the third portion 22A. The fifth portion 22C constitutes the projections 24E and 24F.

[0052] The components of the electrolytic capacitor according to this embodiment will be described in detail below.

[0053] (Anode part) The anode section comprises an anode body and an anode wire extending from one surface of the anode body and electrically connected to an anode lead frame. The anode is, for example, a rectangular porous sintered body obtained by sintering metal particles. As the metal particles, valve metal particles such as titanium (Ti), tantalum (Ta), and niobium (Nb) are used. One or more types of metal particles are used for the anode 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, etc. can be used. Alternatively, a compound containing a valve metal and a typical element such as nitrogen may be used. The valve metal alloy preferably has a valve metal as its main component and contains 50 atomic percent or more of the valve metal.

[0054] The anode wire is made of a conductive material. The material of the anode wire is not particularly limited, and examples include copper, aluminum, aluminum alloy, etc., in addition to the valve metal mentioned above. The materials constituting the anode body and the anode wire may be the same or different. The cross-sectional shape of the anode wire is not particularly limited, and examples include circular, track shape (a shape consisting of parallel straight lines and two curves connecting the ends of these lines), elliptical, rectangular, polygonal, etc. Among these, the track shape is preferred because rolling is suppressed and positioning is easier when welding to the anode lead frame. The diameter of the anode wire (the major axis in the case of track shape and elliptical shape) is also not particularly limited, but for example, it is 0.1 mm or more and 1.0 mm or less.

[0055] A dielectric layer is formed on the surface of the anode. The dielectric layer is composed of, for example, a metal oxide. Methods for forming a layer containing a metal oxide on the surface of the anode include, for example, immersing the anode in a chemical solution to anodize the surface of the anode, or heating the anode in an oxygen-containing atmosphere. The dielectric layer is not limited to the layer containing the metal oxide described above, but only needs to have insulating properties.

[0056] (Cathode part) The cathode portion comprises a solid electrolyte layer formed on a dielectric layer and a cathode layer covering the solid electrolyte layer. The solid electrolyte layer only needs to be formed so as to cover at least a portion of the dielectric layer. For example, manganese compounds or conductive polymers can be used for the solid electrolyte layer. Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyparaphenylenevinylene, polyacene, polythiophenevinylene, polyfluorene, polyvinylcarbazole, polyvinylphenol, polypyridine, or derivatives of these polymers. These may be used individually or in combination. The conductive polymer may also be a copolymer of two or more monomers. Among these, polythiophene, polyaniline, and polypyrrole are preferred in terms of their excellent conductivity. Polypyrrole is particularly preferred in terms of its excellent water repellency.

[0057] The solid electrolyte layer containing the conductive polymer described above is formed, for example, by polymerizing raw material monomers on the dielectric layer 3. Alternatively, it is formed by coating the dielectric layer 3 with a liquid containing the conductive polymer. The solid electrolyte layer consists of one or more solid electrolyte layers. When the solid electrolyte layer consists of two or more layers, the composition of the conductive polymer used in each layer and the method of formation (polymerization method) may differ.

[0058] The cathode layer includes, for example, a carbon layer formed to cover the solid electrolyte layer and a metal paste layer formed on the surface of the carbon layer. The carbon layer contains a conductive carbon material such as graphite and a resin. The metal paste layer contains, for example, metal particles (e.g., silver) and a resin. However, the configuration of the cathode layer is not limited to this configuration. The configuration of the cathode layer may be any configuration that has a current collection function.

[0059] (Anode lead frame) The anode lead frame is electrically connected to the anode body via anode wires. The material of the anode lead frame is not particularly limited as long as it is electrochemically and chemically stable and conductive, and may be metallic or nonmetallic. Its shape is, for example, elongated and flat. From the viewpoint of reducing the height, the thickness of the anode lead frame (distance between the main surfaces of the anode lead frame) is preferably 25 μm to 200 μm, and more preferably 25 μm to 150 μm.

[0060] The anode lead frame may be joined to the anode wire by conductive adhesive or solder, or by resistance welding or laser welding. The conductive adhesive is, for example, a mixture of a thermosetting resin and carbon particles or metal particles, as described later.

[0061] (Cathode lead frame) The cathode lead frame is electrically connected to the cathode. The material of the cathode lead frame is not particularly limited as long as it is electrochemically and chemically stable and conductive, and may be metallic or nonmetallic. Its shape is also not particularly limited, for example, it may be long and flat. From the viewpoint of reducing the profile, the thickness of the cathode lead frame is preferably 25 μm to 200 μm, and more preferably 25 μm to 150 μm. The cathode lead frame is bonded to the cathode, for example, via a conductive adhesive.

[0062] (Exterior) The outer casing is provided to electrically insulate the anode lead frame and the cathode lead frame, and is made of an insulating material. The outer casing includes, for example, a cured product of a thermosetting resin. Examples of thermosetting resins include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester.

[0063] (Note) The above description of embodiments discloses the following technologies. (Technology 1) A capacitor element comprising an anode portion and a cathode portion, an anode lead frame electrically connected to the anode portion, A cathode lead frame electrically connected to the cathode portion, The capacitor element is covered by an outer casing, with a portion of the anode lead frame and the cathode lead frame exposed. The anode portion is, Anode and, The anode body has an anode wire extending from the mounting surface, The anode lead frame is A first portion is exposed from the first main surface of the exterior body facing the planting surface and extends along the first main surface, It has a second portion that is bent from the first portion and embedded in the outer casing, The second part is an electrolytic capacitor having a projection that protrudes in a direction intersecting the extending direction of the anode wire. (Technology 2) The second portion comprises a third portion that bends from the first portion and extends toward the anode wire, It has a fourth portion that rises from the third portion, intersects with the third portion, and protrudes so as to intersect with the mounting surface which is the second main surface of the exterior body, The electrolytic capacitor described in Technical Reference 1, wherein the fourth portion constitutes the projection. (Technology 3) The electrolytic capacitor according to Technology 2, wherein the fourth portion rises from the third portion on the side opposite to the junction surface between the anode wire and the second portion. (Technology 4) The electrolytic capacitor according to Technology 2 or 3, wherein the rising position of the fourth portion is located between the end on the anode body side of the overlapping portion of the anode wire that overlaps with the third portion of the anode wire in the extending direction of the anode wire, and the extending end of the anode wire. (Technology 5) The electrolytic capacitor according to Technical 4, wherein the fourth portion rises from the third portion at the position of the end on the anode body side in the overlapping portion in the direction of extension of the anode wire. (Technology 6) The second portion comprises a third portion that bends from the first portion and extends toward the anode wire, It has a fifth portion that protrudes from the third portion in a direction away from the anode wire along the planar direction of the third portion, The electrolytic capacitor described in Technical Reference 1, wherein the fifth portion constitutes the projection. (Technology 7) The projection has a rising portion that protrudes in a first direction intersecting the extending direction of the anode wire, An electrolytic capacitor according to any one of the technologies 1 to 6, having a folded portion that bends from the rising portion and extends in a direction intersecting the first direction. (Technology 8) The electrolytic capacitor according to any one of the technologies 1 to 7, wherein the projection includes a weld mark at the joint between the anode wire and the second portion. (Technology 9) The electrolytic capacitor according to any one of the technologies 1 to 8, wherein the protruding height of the projection is 1 to 10 times the thickness of the anode lead frame. (Technology 10) The coefficient of linear expansion α of the anode wire A And the coefficient of linear expansion α of the anode lead frame B And the coefficient of linear expansion α of the exterior body C That is, α A <α C <α BAn electrolytic capacitor that satisfies one of the following technical requirements (1-9). [Industrial applicability]

[0064] The electrolytic capacitor according to the present invention has high reliability and can be used in a variety of applications. [Explanation of Symbols]

[0065] 100: Electrolytic capacitor 10: Capacitor element 1: Anode 2: Anode wire 3: Dielectric layer 4: Solid electrolyte layer 5: Cathode layer 6: Anode section 7: Cathode part 20: Anode lead frame 21: Part 1 22:Second part 22A: 3rd part 22B: 4th part (protrusion) 22D: Folded section 22C: 5th part (protrusion) 24A~24F:Protrusion 25: Cathode lead frame 26: Part 1 27:Second part 29: Conductive adhesive layer 30: Exterior S1: First main surface S2: 2nd principal surface S3: Third main surface S4: Fourth main surface

Claims

1. A capacitor element comprising an anode portion and a cathode portion, an anode lead frame electrically connected to the anode portion, A cathode lead frame electrically connected to the cathode portion, The capacitor element is covered by an outer casing, with a portion of the anode lead frame and the cathode lead frame exposed. The anode portion is, Anode and, The anode body has an anode wire extending from the mounting surface, The anode lead frame is A first portion is exposed from the first main surface of the exterior body facing the planting surface and extends along the first main surface, It has a second portion that is bent from the first portion and embedded in the outer casing, The second part is an electrolytic capacitor having a projection that protrudes in a direction intersecting the extending direction of the anode wire.

2. The second portion comprises a third portion that bends from the first portion and extends toward the anode wire, It has a fourth portion that rises from the third portion, intersects with the third portion, and protrudes so as to intersect with the mounting surface which is the second main surface of the exterior body, The electrolytic capacitor according to claim 1, wherein the fourth portion constitutes the projection.

3. The electrolytic capacitor according to claim 2, wherein the fourth portion rises from the third portion on the side opposite to the junction surface between the anode wire and the second portion.

4. The electrolytic capacitor according to claim 2, wherein the rising position of the fourth portion is located between the end on the anode body side of the overlapping portion of the anode wire that overlaps with the third portion of the anode wire in the extending direction of the anode wire, and the extending end of the anode wire.

5. The electrolytic capacitor according to claim 4, wherein the fourth portion rises from the third portion at the position of the end on the anode body side in the overlapping portion in the extending direction of the anode wire.

6. The second portion comprises a third portion that bends from the first portion and extends toward the anode wire, It has a fifth portion that protrudes from the third portion in a direction away from the anode wire along the planar direction of the third portion, The electrolytic capacitor according to claim 1, wherein the fifth portion constitutes the projection.

7. The projection has a rising portion that protrudes in a first direction intersecting the extending direction of the anode wire, An electrolytic capacitor according to any one of claims 1 to 6, having a folded portion that bends from the rising portion and extends in a direction intersecting the first direction.

8. The electrolytic capacitor according to any one of claims 1 to 6, wherein the projection includes a welding mark at the joint between the anode wire and the second portion.

9. The electrolytic capacitor according to any one of claims 1 to 6, wherein the protruding height of the projection is 1 to 10 times the thickness of the anode lead frame.

Images