Solid electrolytic capacitor

Abstract

A solid electrolytic capacitor according to the present disclosure comprises: a first end surface and a second end surface; a top surface and a bottom surface that connect the first end surface and the second end surface; and a first side surface and a second side surface that connect the first end surface, the second end surface, the top surface, and the bottom surface. The solid electrolytic capacitor further comprises: an exterior body that has a rectangular parallelepiped shape; a capacitor element that has a positive electrode part and a negative electrode part and is encapsulated inside the exterior body; a lead frame which is electrically connected to the negative electrode part and at least a portion of which is encapsulated by the exterior body; a first external electrode electrically connected to the positive electrode part at the first end surface; and a second external electrode electrically connected to the lead frame at the second end surface. The negative electrode part has a solid electrolyte layer containing a conductive polymer. The lead frame has an overhanging part exposed from the bottom surface side at the second end surface, and is electrically connected to the second external electrode via the overhanging part. The R dimension or C dimension of the side where the bottom surface and the second end surface meet is smaller than the R dimension or C dimension of the side where the bottom surface and the first side surface meet.

Description

solid electrolytic capacitor

[0001] The present invention relates to a solid electrolytic capacitor.

[0002] A solid electrolytic capacitor includes, for example, at least one capacitor element and an exterior body that seals the capacitor element. The capacitor element includes, for example, an anode portion, a dielectric layer that covers at least a portion of the anode portion, and a cathode portion that covers at least a portion of the dielectric layer. In the capacitor element, the cathode portion includes, for example, a solid electrolyte layer that covers at least a portion of the dielectric layer and a cathode extraction layer that covers at least a portion of the solid electrolyte layer, and the solid electrolyte layer typically contains a conductive polymer.

[0003] Patent Document 1 listed below describes a solid electrolytic capacitor including at least one capacitor element including an anode portion made of a metal layer extending in a first direction, a dielectric layer provided on the outer surface of the metal layer, a solid electrolyte layer provided on a portion of the outer surface of the dielectric layer, and a cathode portion having a current collector layer provided on the outer surface of the solid electrolyte layer, a lead conductor layer connected to the current collector layer, an insulating resin body (corresponding to an outer body) on which the capacitor element and the lead conductor layer are provided, a first external electrode electrically connected to the cathode portion, and a second external electrode electrically connected to the anode portion.

[0004] Patent Document 1 below describes that the insulating resin body has a first end face and a second end face that face each other in the first direction, a first main face and a second main face that face each other in a second direction perpendicular to the first direction, and a first side face and a second side face that face each other in a third direction perpendicular to the first and second directions, and that the insulating resin body has a first connection portion that connects the first end face and the first main face, a second connection portion that connects the first end face and the second main face, a third connection portion that connects the second end face and the first main face, a fourth connection portion that connects the second end face and the second main face, a fifth connection portion that connects the first end face and the first side face, a sixth connection portion that connects the first end face and the second side face, a seventh connection portion that connects the second end face and the first side face, and an eighth connection portion that connects the second end face and the second side face. Furthermore, the following Patent Document 1 describes that each of the first to fourth connection portions has a first chamfered portion, and that each of the fifth to eighth connection portions has a second chamfered portion.

[0005] The following Patent Document 1 describes that a first external electrode is provided across the first connection portion, second connection portion, fifth connection portion, and sixth connection portion, from the first end face to the first and second main surfaces and the first and second side surfaces, i.e., along the first chamfered portions provided on the first and second connection portions and the second chamfered portions provided on the fifth and sixth connection portions, and describes that by providing the first external electrode in this manner, it is possible to alleviate the stress acting on the first external electrode at the boundary between the first end face and the first and second main surfaces, and to improve the adhesion of the first external electrode to the surface of the insulating resin body on the first end face side. Furthermore, the following Patent Document 1 describes that a second external electrode is provided across the third, fourth, seventh, and eighth connection portions, from the second end face to the first and second main surfaces and the first and second side surfaces, i.e., along the first chamfered portions provided on the third and fourth connection portions and the second chamfered portions provided on the seventh and eighth connection portions, and describes that by providing the second external electrode in this manner, it is possible to alleviate the stress acting on the second external electrode at the boundary between the second end face and the first and second main surfaces, and to improve the adhesion of the second external electrode to the surface of the insulating resin body on the second end face side.

[0006] Patent No. 6686975

[0007] In the solid electrolytic capacitor described above, when the solid electrolyte layer included in the capacitor element comes into contact with air, the oxygen in the air can oxidize and degrade the conductive polymer included in the solid electrolyte layer. Oxidative degradation of the conductive polymer can cause the solid electrolyte layer to have poor conductivity, resulting in a decrease in the reliability (e.g., capacity retention) of the solid electrolytic capacitor. In such cases, the solid electrolytic capacitor will not be able to fully demonstrate its characteristics.

[0008] As explained above, Patent Document 1 focuses on the structure of the insulating resin body and considers alleviating the stress acting on the first external electrode and the second external electrode from the insulating resin body and improving the adhesion of the first external electrode and the second external electrode to the insulating resin body, but does not consider at all how to suppress oxidative degradation of the conductive polymer.

[0009] Therefore, an object of the present disclosure is to provide a solid electrolytic capacitor that can suppress oxidative degradation of conductive polymers.

[0010] One aspect of the present invention provides a capacitor element including a rectangular parallelepiped exterior housing having first and second end faces that face each other in a first direction, top and bottom faces that face each other in a second direction perpendicular to the first direction and that connect the first and second end faces, respectively, and first and second side faces that face each other in a third direction perpendicular to the first and second directions and that connect the first and second end faces and the top and bottom faces, respectively; an anode portion and a cathode portion, the capacitor element having the anode portion and the cathode portion sealed inside the exterior housing; and a lead frame electrically connected to the cathode portion and at least a portion of which is sealed in the exterior housing. the cathode portion has a solid electrolyte layer containing a conductive polymer; the lead frame has a protrusion that is exposed more from the bottom surface side than from the top surface side at the second end surface; and the lead frame is electrically connected to the second external electrode via the protrusion; and the R dimension or C dimension of the side where the bottom surface and the second end surface overlap is smaller than the R dimension or C dimension of the side where the bottom surface and the first side surface overlap.

[0011] According to the present disclosure, it is possible to provide a solid electrolytic capacitor capable of suppressing oxidative degradation of a conductive polymer.

[0012] 2A is a cross-sectional view showing the configuration of a capacitor element according to an embodiment of the present disclosure; FIG. 2B is a side cross-sectional view showing the configuration of a solid electrolytic capacitor according to a first embodiment of the present disclosure; FIG. 2C is a plan view of the solid electrolytic capacitor when viewed from above; FIG. 2D is a schematic perspective view of the exterior body of the solid electrolytic capacitor according to the first embodiment; FIG. 2E is a plan view of the exterior body when viewed from a first side surface in the solid electrolytic capacitor according to the first embodiment; FIG. 2F is a plan view of the exterior body when viewed from a bottom surface in the solid electrolytic capacitor according to the first embodiment; FIG. 2G is a plan view of the exterior body when viewed from a second end surface in the solid electrolytic capacitor according to the second embodiment; FIG. 2G is a side cross-sectional view showing the configuration of a solid electrolytic capacitor according to a third embodiment of the present disclosure; FIG. 2H is a plan view of the solid electrolytic capacitor when viewed from above; FIG. 2J is a plan view of the solid electrolytic capacitor according to the third embodiment;

[0013] Below, embodiments of the present disclosure will be described using examples, but 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, materials, etc. may be applied as long as the effects of the present disclosure are obtained. Note that known components may be applied to components characteristic of the present disclosure. In this specification, when a "range from numerical value A to numerical value B" is mentioned, the range includes numerical value A and numerical value B.

[0014] In the following description, when lower and upper limits of numerical values ​​relating to specific physical properties, conditions, etc. are exemplified, any of the exemplified lower limits and any of the exemplified upper limits can be arbitrarily combined, as long as the lower limit is not equal to or greater than the upper limit. When multiple materials are exemplified, one of them can be selected and used alone, or two or more can be used in combination, unless otherwise specified.

[0015] The present disclosure encompasses any combination of two or more features arbitrarily selected from the appended claims, i.e., any combination of two or more features arbitrarily selected from the appended claims can be combined unless a technical contradiction arises.

[0016] [Solid Electrolytic Capacitor] A solid electrolytic capacitor according to an embodiment of the present disclosure includes a rectangular parallelepiped outer casing including a first end face and a second end face that face each other in a first direction, a top face and a bottom face that face each other in a second direction perpendicular to the first direction and that respectively connect the first end face and the second end face, and a first side face and a second side face that face each other in a third direction perpendicular to the first and second directions and that respectively connect the first end face and the second end face and the top face and the bottom face, and includes: a capacitor element having an anode portion and a cathode portion and sealed inside the outer casing; a lead frame electrically connected to the cathode portion and at least a portion of which is sealed in the outer casing; a first external electrode electrically connected to the anode portion at the first end face; and a second external electrode electrically connected to the lead frame at the second end face.

[0017] <Capacitor Element> First, the capacitor element will be described below with reference to FIG.

[0018] 1 , capacitor element 10 includes anode portion 11, dielectric layer 12 covering at least a portion of anode portion 11, solid electrolyte layer 13 covering at least a portion of dielectric layer 12, and cathode extraction layer 14 covering at least a portion of solid electrolyte layer 13. That is, in capacitor element 10, as described above, cathode portion 15 includes solid electrolyte layer 13. In capacitor element 10, cathode portion 15 is formed by, for example, solid electrolyte layer 13 and cathode extraction layer 14. With this configuration, capacitor element 10 includes anode portion 11 and cathode portion 15.

[0019] The anode portion 11 and the cathode portion 15 extend along a first direction (direction D1 in FIG. 1 ) in which a first end surface and a second end surface of the exterior body face each other. In the example shown in FIG. 1 , the anode portion 11 is covered with a dielectric layer 12 so that one side in the first direction D1 is exposed. That is, in the example shown in FIG. 1 , the anode portion 11 has a covered portion C covered with the dielectric layer 12 and an uncovered portion NC that is not covered with the dielectric layer 12. It is preferable that an insulating separation portion (insulating region, not shown) be formed in a portion of the uncovered portion NC adjacent to the cathode portion 15 so as to cover the surface of the anode portion 11 in a strip shape, thereby restricting contact between the anode portion 11 and the cathode portion 15.

[0020] The anode part 11 may be formed of an anode body made of a valve metal. Examples of the valve metal constituting the anode body include aluminum, tantalum, niobium, and titanium. The anode body may be a valve metal foil or a sintered body of valve metal particles. When the anode body is a valve metal foil, the foil may be etched from the outer surface toward the center. That is, an etched layer (porous portion) may be formed on the surface layer of the foil.

[0021] The dielectric layer 12 may be made of an oxide (e.g., aluminum oxide) formed on the surface of the anode body by a liquid phase method such as anodization, or a gas phase method such as vapor deposition or atomic layer deposition.

[0022] The solid electrolyte layer 13 is formed on the surface of the dielectric layer 12. The solid electrolyte layer 13 contains a conductive polymer. The solid electrolyte layer 13 may further contain a dopant in addition to the conductive polymer.

[0023] Examples of conductive polymers include known polymers used in solid electrolytic capacitors, such as π-conjugated conductive polymers. Examples of conductive polymers include polymers with a basic skeleton of polypyrrole, polythiophene, polyaniline, polyfuran, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, and polythiophene vinylene. Of these, polymers with a basic skeleton of polypyrrole, polythiophene, or polyaniline are preferred. The above polymers also include homopolymers, copolymers of two or more monomers, and derivatives thereof (e.g., substituted products having substituents). For example, polythiophenes include poly(3,4-ethylenedioxythiophene). Conductive polymers may be used alone or in combination of two or more.

[0024] The dopant may be, for example, at least one selected from the group consisting of low molecular weight anions and polyanions. Examples of low molecular weight anions include sulfate ions, nitrate ions, phosphate ions, borate ions, organic sulfonate ions, and carboxylate ions. Examples of dopants that generate organic sulfonate ions include benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. Examples of polyanions include polymeric polysulfonic acids and polymeric polycarboxylic acids. Examples of polymeric polysulfonic acids include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylicsulfonic acid, and polymethacrylicsulfonic acid. Examples of polymeric polycarboxylic acids include polyacrylic acid and polymethacrylic acid. Examples of polyanions include polyestersulfonic acid and phenolsulfonic acid novolac resin. However, the polyanions are not limited to the examples listed above.

[0025] The solid electrolyte layer 13 may further contain known additives and known conductive materials other than conductive polymers, as needed. Examples of such conductive materials include at least one selected from the group consisting of conductive inorganic materials such as manganese dioxide and TCNQ (tetracyanoxydimethane) complex salts.

[0026] The cathode extraction layer 14 may be composed of a carbon layer (not shown) formed on the surface of the solid electrolyte layer 13 and a conductor layer (not shown) formed on the surface of the carbon layer. The conductor layer may be composed of a metal paste layer containing metal particles, or a silver paste layer. The silver paste layer may be composed of, for example, a composition containing silver particles and a resin component (binder resin). The resin component may be either a thermoplastic resin or a thermosetting resin, but a thermosetting resin is preferably used. Examples of thermosetting resins include imide resins and epoxy resins.

[0027] First Embodiment Next, a solid electrolytic capacitor according to a first embodiment of the present disclosure will be described with reference to FIGS. 2A to 2F. The exterior package shown in FIG. 2C does not include the R-surfaces shown in FIGS. 2D and 2E. In the example shown in FIG. 2A, the solid electrolytic capacitor 100 includes multiple capacitor elements 10. Specifically, as shown in FIG. 2A, the multiple capacitor elements 10 are stacked in the height direction with their main surfaces overlapping each other. As shown in FIG. 2A, the multiple capacitor elements 10 are stacked in the solid electrolytic capacitor 100 such that the protruding end faces San of the anode portions 11 and the terminal faces Sca of the cathode portions 15 are oriented in the same direction in the first direction D1 in which the first end face E1 and the second end face E2 face each other.

[0028] The solid electrolytic capacitor 100 of the first embodiment comprises a lead frame 110 electrically connected to each of the cathode portions 15 of the plurality of capacitor elements 10, an outer casing 120 that seals the plurality of capacitor elements 10 and at least a portion of the lead frame 110, a first external electrode 130 electrically connected to each of the anode portions 11 of the plurality of capacitor elements 10 at a first end face E1 on one side of the outer casing 120 in the first direction D1, and a second external electrode 140 electrically connected to the lead frame 110 at a second end face E2 on the other side of the outer casing 120 in the first direction D1.

[0029] The exterior body 120 may be a resin exterior body or may be another exterior body. In the solid electrolytic capacitor 100, the exterior body 120 has a rectangular parallelepiped shape as shown in FIG. 2C . The exterior body 120 includes a first end face E1 and a second end face E2 that face each other in a first direction D1, a top face R and a bottom face B that face each other in a second direction D2 that is perpendicular to the first direction D1 and that connect the first end face E1 and the second end face E2, respectively, and a first side face S1 and a second side face S2 that face each other in a third direction D3 that is perpendicular to the first direction D1 and the second direction D2 and that connect the first end face E1, the second end face E2, the top face R, and the bottom face B, respectively.

[0030] In the exterior body 120, the side Sa, where the bottom surface B and the first side surface S1 overlap, has an R-shaped surface or a C-shaped surface. Note that FIGS. 2D and 2E illustrate an embodiment in which the side Sa has an R-shaped surface. Here, as described below, the second end surface E2 of the exterior body 120 and the second external electrode 140 may be connected by a second conductive paste layer or a metal layer. The metal layer can be formed by various known methods, such as sputtering or plating. The metal layer is typically composed solely of a metal material. Having the side Sa with an R-shaped surface or a C-shaped surface as described above not only ensures sufficient adhesion of the second external electrode 140 to the exterior body 120, but also ensures sufficient electrical connection between the lead frame 110 and the second external electrode 140. The metal layer is also a component of the second external electrode 140. The metal layer may be formed on a portion of the second end surface E2, or may be formed on the entire second end surface E2. That is, the metal layer may be formed on at least a part of the second end face E2.

[0031] When the side Sa has a rounded surface, the R dimension of the side Sa is preferably 0.03 mm or more and 0.2 mm or less (R 0.03 or more and R 0.2 or less). The R dimension is defined in terms of R-chamfering. When the side Sa has a rounded surface, cracks or chips can be prevented from occurring in the side Sa when an external force is applied to the side Sa.

[0032] When the side Sa has a chamfered surface, the C dimension of the side Sa is preferably 0.03 mm or more and 0.2 mm or less (C0.03 or more and C0.2 or less). The C dimension is defined in terms of chamfered chamfering. When the side Sa has a chamfered surface, the gap generated near the side Sa can be larger than when the side Sa has a rounded surface. This not only ensures more sufficient adhesion of the second external electrode 140 to the exterior body 120, but also ensures more sufficient electrical continuity between the lead frame 110 and the second external electrode 140, compared to when the side Sa has a rounded surface. On the other hand, since it is sufficient to ensure a certain degree of adhesion of the second external electrode 140 to the exterior body 120, it is preferable to employ a rounded surface from the viewpoint of preventing cracks and chips in the exterior body 120.

[0033] In the exterior body 120, the R dimension or C dimension of the side Sb where the bottom surface B and the second end surface E2 overlap is smaller than the R dimension or C dimension of the side Sa. Specifically, in the exterior body 120, the side Sb does not substantially have an R-surface or a C-surface. Here, "the side Sb does not substantially have an R-surface" means that the R dimension of the side Sb is less than 0.0001 mm, and "the side Sb does not have a C-surface" means that the C dimension of the side Sb is less than 0.0001 mm. Note that Figures 2D and 2E show an embodiment in which the side Sb does not substantially have an R-surface or a C-surface.

[0034] As described below, the lead frame 110 has a protruding portion 112 that is exposed more from the bottom surface B than from the top surface R at the second end surface E2 of the exterior package 120, and is electrically connected to the second external electrode 140 via this protruding portion 112. More specifically, the lead frame 110 is electrically connected to the second external electrode 140 via the protruding end surface Ss of the protruding portion 112. Therefore, on the second end surface E2 side, air contained in the atmosphere often enters the interior of the exterior package 120 mainly via the protruding end surface Ss of the protruding portion 112 along the first direction D1. From this perspective, it is preferable that the exterior package 120 have a sufficient thickness near the edge Sb located on the bottom surface B side of the second end surface E2. Note that in the solid electrolytic capacitor 100 according to the first embodiment, the lead frame 110 includes a pair of first protruding portions 112A spaced apart from each other (see FIG. 2F ). The first protruding portions 112A will be described later.

[0035] As described above, in the exterior body 120, the side Sb located on the bottom surface B side of the second end face E2 has a smaller R dimension or C dimension than the side Sa. In other words, the vicinity of the side Sb has a sufficient thickness. This prevents atmospheric air from entering the interior of the exterior body 120 via the protruding end face Ss of the protruding portion 112. This sufficiently prevents the conductive polymer contained in the capacitor element sealed within the exterior body 120 from being oxidized and deteriorated.

[0036] In the exterior body 120, the side Sc, where the bottom surface B and the second side surface S2 overlap, preferably has an R-surface or a C-surface. That is, the R-dimension or C-dimension of the side Sb, where the bottom surface B and the second end surface E2 overlap, is preferably smaller than the R-dimension or C-dimension of the side Sc. In such a case, a gap can be formed near the side Sc. This not only ensures sufficient adhesion of the second external electrode 140 to the exterior body 120, but also ensures sufficient electrical connection between the lead frame 110 and the second external electrode 140. When the side Sc has an R-surface, the R-dimension of the side Sc is preferably 0.03 mm or more and 0.2 mm or less (R 0.03 mm or more and R 0.2 mm or less). When the side Sc has a C-surface, the C-dimension of the side Sc is preferably 0.03 mm or more and 0.2 mm or less (C 0.03 mm or more and C 0.2 mm or less).

[0037] In the exterior body 120, the side Sd where the second end face E2 and the first side face S1 overlap preferably has an R-shaped or C-shaped surface. That is, the R-dimension or C-dimension of the side Sb where the bottom face B and the second end face E2 overlap preferably is smaller than the R-dimension or C-dimension of the side Sd. In such a case, a gap can be formed near the side Sd. This not only ensures sufficient adhesion of the second external electrode 140 to the exterior body 120, but also ensures sufficient electrical connection between the lead frame 110 and the second external electrode 140. When the side Sd has an R-shaped surface, the R-dimension of the side Sd is preferably 0.03 mm or more and 0.2 mm or less (R 0.03 mm or more and R 0.2 mm or less). When the side Sd has a C-shaped surface, the C-dimension of the side Sd is preferably 0.03 mm or more and 0.2 mm or less (C 0.03 mm or more and C 0.2 mm or less).

[0038] In the exterior body 120, the side Se, where the second end face E2 and the second side face S2 overlap, preferably has an R-surface or a C-surface. That is, the R-dimension or C-dimension of the side Sb, where the bottom face B and the second end face E2 overlap, is preferably smaller than the R-dimension or C-dimension of the side Se. In such a case, a gap can be formed near the side Se. This not only ensures sufficient adhesion of the second external electrode 140 to the exterior body 120, but also ensures sufficient electrical connection between the lead frame 110 and the second external electrode 140. When the side Se has an R-surface, the R-dimension of the side Se is preferably 0.03 mm or more and 0.2 mm or less (C0.03 mm or more and C0.2 mm or less). When the side Se has a C-surface, the C-dimension of the side Se is preferably 0.03 mm or more and 0.2 mm or less (C0.03 mm or more and C0.2 mm or less).

[0039] The first external electrode 130 and the second external electrode 140 can be obtained, for example, by applying a conductive paste containing conductive particles (e.g., silver particles) to the first end face E1 and the second end face E2 of the exterior body 120, drying the paste to form a conductive paste layer, and then plating a metal (e.g., nickel) on the conductive paste layer to form a metal plating layer. In the solid electrolytic capacitor 100, the first external electrode 130 is configured to cover the first end face E1 of the exterior body 120, and the second external electrode 140 is configured to cover the second end face E2 of the exterior body 120.

[0040] In the solid electrolytic capacitor 100 according to the first embodiment, the lead frame 110 has a protruding portion 112 (more specifically, a first protruding portion 112A) that is exposed from the bottom surface B side of the second end surface E2 of the exterior package 120 relative to the top surface R side. As shown in FIGS. 2A and 2F , the protruding portion 112 is located on the side Sb side of the second end surface E2 of the exterior package 120. The lead frame 110 is electrically connected to the second external electrode 140 via the protruding portion 112. Specifically, at the second end surface E2 of the exterior package 120, the protruding end surface Ss of the protruding portion 112 of the lead frame 110 is exposed (see FIGS. 2A and 2F ) and is electrically connected to the second external electrode 140.

[0041] The length L of the protruding portion 112 is preferably 0.60 mm or less, and more preferably 0.40 mm or less. The lower limit of the length L of the protruding portion 112 is typically 0.15 mm. The protruding portion 112 includes a first protruding portion 112A and a second protruding portion 112B, which will be described later. Therefore, the lengths L of the first protruding portion 112A and the second protruding portion 112B are also preferably within the above range. The second protruding portion 112B is a protruding portion provided in the solid electrolytic capacitor 100 according to the second and third embodiments, which will be described later.

[0042] As shown in FIG. 2A , the lead frame 110 preferably has a sidewall 111 that extends along the second end surface E2 of the exterior package 120 and faces the end surface Sca of the cathode portion 15 in the first direction D1. The sidewall 111 of the lead frame 110 and the plurality of capacitor elements 10 are connected by a first conductive paste layer (not shown). This allows electrical connection between each of the cathode portions 15 of the plurality of capacitor elements 10 and the sidewall 111 of the lead frame 110. More specifically, the sidewall 111 of the lead frame 110 can be electrically connected to each of the end surfaces Sca of the cathode portions 15 of the plurality of capacitor elements 10. Furthermore, the second end surface E2 of the exterior package 120 and the second external electrode 140 may be connected by a second conductive paste layer, as described above, or by a metal layer. The metal layer can be formed by various known methods, such as sputtering or plating. This allows electrical connection between the second external electrode 140 and the protruding portion 112 of the lead frame 110. The first conductive paste layer and the second conductive paste layer can be formed using various known conductive adhesives. In the lead frame 110, the side wall portion 111 is usually formed by bending a portion of a flat plate (e.g., a metal plate).

[0043] In the solid electrolytic capacitor 100 according to the first embodiment, the anode portion 11 has a protruding end surface San exposed at the first end surface E1 of the exterior body 120. The anode portion 11 is electrically connected to the first external electrode 130 via the protruding end surface San. In other words, the protruding end surface San of the anode portion 11 is exposed at the first end surface E1 of the exterior body 120 and is electrically connected to the first external electrode 130. Specifically, the first end surface E1 of the exterior body 120 and the first external electrode 130 may be connected, for example, by a third conductive paste layer (not shown) or by a metal layer. The metal layer can be formed by various known methods, such as sputtering or plating. The metal layer is typically composed only of a metal material. The metal layer is also a component of the first external electrode 130. The metal layer may be formed on a portion of the first end surface E1 or on the entire first end surface E1. That is, the metal layer may be formed on at least a part of the first end face E1.

[0044] When the anode portion 11 is electrically connected to the first external electrode 130 via the protruding end surface San as described above, it is preferable that the R dimension or C dimension of the side Sf, where the bottom surface B and the first end surface E1 overlap, in the exterior body 120, be smaller than the R dimension or C dimension of the side Sa, where the bottom surface B and the first side surface S1 overlap. Specifically, it is preferable that the side Sf of the exterior body 120 substantially does not have an R or C surface. This ensures more sufficient electrical continuity between the protruding end surface San of the anode portion 11 and the first external electrode 130. This also prevents atmospheric air from entering the interior of the exterior body 120 via the protruding end surface San of the anode portion 11. This sufficiently prevents oxidative degradation of the conductive polymer contained in the capacitor element 10 sealed in the exterior body 120.

[0045] In the exterior body 120, the R dimension or C dimension of the side Sf preferably has an R-surface or C-surface and is smaller than the R dimension or C dimension of the sides other than the side Sa. Specifically, the side Sf is preferably smaller than the R dimension or C dimension of the side Sc where the bottom surface B and the second side surface S2 overlap, is preferably smaller than the R dimension or C dimension of the side Sg where the first end surface E1 and the first side surface S1 overlap, and is preferably smaller than the R dimension or C dimension of the side Sh where the first end surface E1 and the second side surface S2 overlap. This provides the same effect as described above on the first end surface E1 side.

[0046] In the exterior body 120, the side Si where the top surface R and the first side surface S1 overlap preferably has an R-surface or a C-surface. On the other hand, the R dimension or C dimension of the side Sj where the top surface R and the second end surface E2 overlap preferably is smaller than the R dimension or C dimension of the side Si. In other words, it is preferable that the side Sj does not substantially have an R-surface or a C-surface. When the side Si has an R-surface, the R dimension of the side Si is preferably 0.03 mm or more and 0.2 mm or less (R 0.03 or more and C 0.2 or less). When the side Si has a C-surface, the C dimension of the side Si is preferably 0.03 mm or more and 0.2 mm or less (C 0.03 or more and C 0.2 or less).

[0047] In the exterior body 120, the side Sk where the top surface R and the second side surface S2 overlap preferably has an R-surface or a C-surface. That is, in the exterior body 120, the R dimension or C dimension of the side Sj is preferably smaller than the R dimension or C dimension of the side Sk. When the side Sk has an R-surface, the R dimension of the side Sk is preferably 0.03 mm or more and 0.2 mm or less (R 0.03 or more and R 0.2 or less). When the side Sk has a C-surface, the C dimension of the side Sk is preferably 0.03 mm or more and 0.2 mm or less (C 0.03 or more and C 0.2 or less).

[0048] In the exterior body 120, the R dimension or C dimension of the side Sj where the top surface R and the second end face E2 overlap is preferably smaller than the R dimension or C dimension of the side Sd where the second end face E2 and the first side face S1 overlap. Also, in the exterior body 120, the R dimension or C dimension of the side Sj is preferably smaller than the R dimension or C dimension of the side Se where the second end face E2 and the second side face S2 overlap.

[0049] In the exterior body 120, it is preferable that the R dimension or C dimension of the side S1 where the top surface R and the first end surface E1 overlap is smaller than the R dimension or C dimension of the side Si where the top surface R and the first side surface S1 overlap. In other words, it is preferable that the side S1 does not substantially have an R surface or a C surface.

[0050] Furthermore, in the exterior body 120, the R dimension or C dimension of the side Sl is preferably smaller than the R dimension or C dimension of the side Sk where the top surface R and the second side surface S2 overlap, is preferably smaller than the R dimension or C dimension of the side Sg where the first end surface E1 and the first side surface S1 overlap, and is preferably smaller than the R dimension or C dimension of the side Sh where the first end surface E1 and the second side surface S2 overlap. This provides the same effects as those described above.

[0051] In the solid electrolytic capacitor 100 according to the first embodiment, as described above, the lead frame 110 includes a pair of first protruding portions 112A spaced apart from each other as the protruding portion 112 (see FIG. 2F ), and the side wall portion 111 extends from between the pair of first protruding portions 112A along the second end face E2 of the exterior body 120 toward the terminal face Sca of the cathode portion 15 (see FIG. 2A ). When the solid electrolytic capacitor 100 is configured as described above, the contact area between the second external electrode 140 and the lead frame 110 can be increased, thereby enabling a more optimal electrical connection between the lead frame 110 and the second external electrode 140.

[0052] In the solid electrolytic capacitor 100 according to the first embodiment, the lead frame 110 further includes a bottom plate portion 113 that extends in the first direction D1 along the lower end surface of the cathode portion 15 and is connected to the side wall portion 111 and the first protruding portion 112A (see FIG. 2A ). With the lead frame 110 configured as described above, the bottom plate portion 113 can adequately support the plurality of capacitor elements 10 from below. In FIG. 2A , the boundary between the bottom plate portion 113 and the first protruding portion 112A is indicated by a dashed line L1. This also applies to the side cross-sectional views ( FIGS. 2G and 2J ) of the solid electrolytic capacitor 100 according to the second and third embodiments described below.

[0053] In solid electrolytic capacitor 100 according to the first embodiment, bottom plate portion 113 of lead frame 110 is connected to the lower end surface of cathode portion 15 of capacitor element 10 by a fourth conductive paste layer (not shown). With this configuration, the lower end surface of capacitor element 10 can also be electrically connected to lead frame 110. That is, bottom plate portion 113 of lead frame 110 can be electrically connected so as to contact the lower end surface of cathode portion 15.

[0054] In the solid electrolytic capacitor 100 according to the first embodiment, a notch S is preferably formed in the lead frame 110 between the pair of first protrusions 112A and the sidewalls 111 (see FIG. 2B ). Here, the sidewalls 111 of the lead frame 110 are typically formed by bending a portion of a flat plate (e.g., a metal plate). Therefore, if the regions corresponding to the sidewalls 111 and the regions corresponding to the pair of first protrusions 112A are in contact with each other in the flat plate, the regions corresponding to the sidewalls 111 are likely to be obstructed by the regions corresponding to the first protrusions 112A when the flat plate is bent. However, by forming the notch S, the regions corresponding to the sidewalls 111 and the regions corresponding to the first protrusions 112A can be kept out of contact with each other in the flat plate. This makes the regions corresponding to the sidewalls 111 less likely to be obstructed by the regions corresponding to the first protrusions 112A when the flat plate is bent. That is, the area corresponding to the side wall portion 111 can be easily bent to any desired position.

[0055] Second Embodiment Next, a solid electrolytic capacitor 100 according to a second embodiment of the present disclosure will be described with reference to Figures 2G to 2I. The solid electrolytic capacitor 100 according to the second embodiment is the same as the solid electrolytic capacitor 100 according to the first embodiment except for the configuration of the lead frame 110. Therefore, the configuration of the lead frame 110 of the solid electrolytic capacitor 100 according to the second embodiment will be described below.

[0056] In the solid electrolytic capacitor 100 according to the second embodiment, as shown in FIGS. 2G to 2I , the lead frame 110 includes a pair of first protrusions 112A spaced apart from each other, as well as a pair of second protrusions 112B on the side wall 111 that is disposed between the pair of first protrusions 112A and extends along the second end face E2 of the exterior package 120. That is, in the solid electrolytic capacitor 100 according to the second embodiment, the lead frame 110 includes a pair of first protrusions 112A and a pair of second protrusions 112B that are disposed between the pair of first protrusions 112A. The pair of second protrusions 112B extend from both side edges of the side wall 111 toward the second end face E2 of the exterior package 120. In the solid electrolytic capacitor 100 according to the second embodiment, the lead frame 110 is electrically connected to the second external electrode 140 via the pair of second protrusions 112B in addition to the pair of first protrusions 112A. In other words, at the second end surface E2 of the outer casing 120, the tip surface Ss of the first protrusion 112A of the lead frame 110 and the tip surface St of the second protrusion 112B are exposed, and are electrically connected to the second external electrode 140 by the tip surface Ss and the tip surface St.

[0057] By configuring the lead frame 110 as described above, it is possible to increase the contact area between the lead frame 110 and the second external electrode 140. This makes it possible to reduce the equivalent series resistance (ESR) of the solid electrolytic capacitor 100.

[0058] 2G shows an example in which a pair of second protrusions 112B are arranged on the upper end sides of the side wall portion 111 in the height direction, but the arrangement of the pair of second protrusions 112B on the side wall portion 111 is not limited to this. The pair of second protrusions 112B may be arranged at any position in the height direction of the side wall portion 111. For example, the pair of second protrusions 112B may be arranged on the lower end sides of the side wall portion 111 in the height direction, or may be arranged on the center side of the side wall portion 111 in the height direction. The pair of second protrusions 112B can be formed, for example, by bending both side edge sides of the side wall portion 111 so as to align with the extension direction of the pair of first protrusions 112A.

[0059] 2J to 2L, a solid electrolytic capacitor 100 according to a third embodiment of the present disclosure will be described. The solid electrolytic capacitor 100 according to the third embodiment is the same as the solid electrolytic capacitor 100 according to the first embodiment except for the configuration of the lead frame 110. Therefore, the configuration of the lead frame 110 of the solid electrolytic capacitor 100 according to the third embodiment will be described below.

[0060] 2J to 2L , in the solid electrolytic capacitor 100 according to the third embodiment, the lead frame 110 includes, in addition to a pair of first protrusions 112A spaced apart from each other, a second protrusion 112B also on the side wall 111 that is disposed between the pair of first protrusions 112A and extends along the second end face E2 of the exterior package 120. That is, in the solid electrolytic capacitor 100 according to the third embodiment, the lead frame 110 includes, in addition to the pair of first protrusions 112A, a second protrusion 112B that is disposed between the pair of first protrusions 112A. The second protrusion 112B extends from the upper edge of the side wall 111 toward the second end face E2 of the exterior package 120. In the solid electrolytic capacitor 100 according to the third embodiment, the lead frame 110 is electrically connected to the second external electrode 140 via one second protruding portion 112B in addition to the pair of first protruding portions 112A. In other words, at the second end surface E2 of the exterior body 120, the protruding end surfaces Ss of the pair of first protruding portions 112A and the protruding end surface St of the one second protruding portion 112B of the lead frame 110 are exposed, and are electrically connected to the second external electrode 140 by the protruding end surfaces Ss and St.

[0061] Similarly to the second embodiment, the lead frame 110 configured as described above can increase the contact area between the lead frame 110 and the second external electrode 140. This can reduce the equivalent series resistance (ESR) of the solid electrolytic capacitor 100.

[0062] One second protruding portion 112B can be formed, for example, by bending the upper edge side of the side wall portion 111 along the extension direction of the pair of first protruding portions 112A.

[0063] (Method of manufacturing solid electrolytic capacitor) A method of manufacturing a solid electrolytic capacitor according to the present disclosure includes: a first step of forming a dielectric layer to cover at least a portion of an anode portion; a second step of forming a cathode portion to cover at least a portion of the dielectric layer to obtain a laminate in which the anode portion, the dielectric layer, and the cathode portion are stacked in this order; a third step of disposing the laminate on a lead frame having sidewall portions and protruding portions extending in a direction intersecting the sidewall portions, with the sidewall portions of the lead frame and an end surface of the cathode portion electrically connected to each other, and sealing the lead frame and the laminate to obtain a sealed body; a fourth step of exposing a protruding end surface of the anode portion from a first end surface of the sealed body and exposing a protruding end surface of the protruding portion of the lead frame from a second end surface of the sealed body; and a fifth step of disposing a first external electrode to be electrically connected to the protruding end surface of the anode portion exposed from the first end surface of the sealed body, and disposing a second external electrode to be electrically connected to the protruding end surface of the protruding portion of the lead frame exposed from the second end surface of the sealed body.

[0064] In the first step, the dielectric layer covering at least a portion of the anode part can be formed by various known methods. The dielectric layer can be formed by oxidizing the valve metal contained in the anode part by chemical conversion treatment or the like. For example, the dielectric layer may be formed by immersing the anode part in a chemical conversion solution and applying a voltage. The anode part may have a porous part formed therein, which includes a plurality of pores opening from the outer surface toward the center. When a porous part is formed in the anode part, the dielectric layer is preferably formed so as to cover at least a portion of the outer surface of the anode part and at least a portion of the inner surface of each of the plurality of pores.

[0065] In the second step, the cathode covering at least a portion of the dielectric layer can be formed by various known methods. The solid electrolyte layer in the cathode can be formed by immersing the anode on which the dielectric layer has been formed in a conductive polymer solution containing a conductive polymer to deposit the conductive polymer solution on the dielectric layer, and then drying the conductive polymer solution deposited on the dielectric layer. When a porous portion is formed in the anode, the anode after depositing the conductive polymer solution on the dielectric layer is preferably exposed to a pressure higher or lower than the pressure P1 applied when the cathode was immersed in the conductive polymer solution. By exposing the anode to a pressure higher than P1, the conductive polymer solution can be forced into the multiple pores at high pressure, while by exposing the anode to a pressure lower than P1, the conductive polymer solution can be drawn into the multiple pores at low pressure. That is, the pressure difference from the pressure P1 allows a portion of the conductive polymer solution deposited on the dielectric layer formed on the outer surface of the anode to move into the multiple pores.

[0066] The cathode extraction layer in the cathode portion can be obtained, for example, by applying a carbon dispersion liquid containing dispersed carbon to cover at least a portion of the solid electrolyte layer, drying the liquid to form a carbon layer, and then applying a composition containing metal particles (e.g., silver particles) and a resin component (binder resin) to cover at least a portion of the carbon layer, and drying the composition to form a conductive layer. Note that, when the binder resin is a thermosetting resin, the binder resin can be thermally cured by the heating.

[0067] In the third step, a lead frame having sidewall portions and protruding portions extending in a direction intersecting the sidewall portions can be obtained by processing a metal plate into a predetermined shape. For example, it can be obtained by performing the bending process described in the first to third embodiments. In addition to the sidewall portions and protruding portions, the lead frame preferably further includes a bottom plate portion connected to the sidewall portions and the protruding portions. By including the bottom plate portion in the lead frame, it is possible to sufficiently support from the underside a laminate in which an anode portion, a dielectric layer, and a cathode portion are stacked in this order. The bottom plate portion preferably extends in the same direction as the extending direction of the protruding portions. In other words, the bottom plate portion preferably extends in a direction intersecting the sidewall portions.

[0068] The lead frame preferably has a pair of first protrusions spaced apart from each other as protrusions. As described above, the first protrusions are protrusions that are exposed from the bottom side of the second end surface of the exterior body, rather than the top side. The first protrusions are also protrusions that are disposed on the lower edge side of the side wall. When the lead frame has a pair of first protrusions, it is preferable that a second protrusion be disposed between the pair of first protrusions, from the viewpoint of reducing the equivalent series resistance (ESR) of the solid electrolytic capacitor. A pair of second protrusions may be disposed between the pair of first protrusions (as in the configuration of the second embodiment described above), or one second protrusion may be disposed between the pair of first protrusions (as in the configuration of the third embodiment described above).

[0069] The side wall portion of the lead frame and the end surface of the cathode portion can be electrically connected, for example, by interposing a conductive paste layer therebetween. The lead frame and the laminate are sealed, for example, by embedding the entire lead frame and the laminate with a sealing resin. When the sealing resin is a thermosetting resin, it is preferable that the sealing resin be thermally cured after embedding the lead frame and the laminate.

[0070] The sealed body obtained by sealing the lead frame and the laminate has a rectangular parallelepiped shape (see FIG. 2C ), including first and second end faces that face each other in a first direction, top and bottom faces that face each other in a second direction perpendicular to the first direction and connect the first and second end faces, respectively, and first and second side faces that face each other in a third direction perpendicular to the first and second directions and connect the first and second end faces, the top and bottom faces, respectively. Furthermore, in this sealed body, at least the side where the bottom face and the first side face overlap has an R-plane or C-plane, while the side where the bottom face and the second end face overlap does not substantially have an R-plane or C-plane. That is, in this sealed body, the R dimension or C dimension of the side where the bottom face and the second end face overlap is smaller than the R dimension or C dimension of the side where the bottom face and the first side face overlap. Such a sealing body can be obtained by using a mold in which a shape corresponding to a C-surface or an R-surface is machined at a location corresponding to the side where the bottom surface and the first side surface overlap.

[0071] In the sealed body, in addition to the edge where the bottom surface and the first side surface overlap, the edge where the bottom surface and the second side surface overlap, the edge where the second end surface and the first side surface overlap, the edge where the second end surface and the second side surface overlap, the edge where the first end surface and the first side surface overlap, the edge where the first end surface and the second side surface overlap, the edge where the top surface and the first side surface overlap, and the edge where the top surface and the second side surface overlap preferably have an R-surface or a C-surface. Such a sealed body can also be obtained using a mold in which a shape corresponding to the C-surface or the R-surface is machined at locations corresponding to each edge. Sealing with a sealing resin is preferably performed by transfer molding.

[0072] On the other hand, in the sealing body, in addition to the side where the bottom surface and the second end face overlap, it is preferable that the side where the bottom surface and the first end face overlap, the side where the top surface and the second end face overlap, and the side where the top surface and the first end face overlap also do not substantially have an R-plane or a C-plane.

[0073] In the fourth step, the first and second end faces of the sealing body are cut to a predetermined size, for example, by blade dicing or using an ultrasonic cutter, so that the protruding end faces of the anode portion and the protruding end faces of the lead frame are exposed. A cold spray treatment may be performed to form a coating on the first and second end faces of the sealing body after cutting. This prevents natural oxidation of the protruding end faces of the anode portion and the protruding end faces of the protruding portion exposed by cutting. Metal particles such as copper (Cu), aluminum (Al), titanium (Ti), silver (Ag), nickel (Ni), zinc (Zn), tin (Sn), molybdenum (Mo), iron (Fe), tantalum (Ta), niobium (Nb), silicon (Si), and chromium (Cr) can be used for the cold spray treatment.

[0074] In the fifth step, the first external electrode can be obtained by applying a conductive paste containing conductive particles (e.g., silver particles) to the first end surface of the cut sealing body, drying the paste to form a conductive paste layer, and then plating a metal (e.g., nickel) on the conductive paste layer to form a metal plating layer. Similarly, the second external electrode can be obtained by forming a conductive paste layer and a metal plating layer in this order on the second end surface of the cut sealing body. The first external electrode obtained as described above is electrically connected to the protruding end surface of the anode portion, and the second external electrode obtained as described above is electrically connected to the protruding end surface of the lead frame. The first external electrode and the protruding end surface of the anode portion may be connected by a conductive paste layer or a metal layer, as described above. Similarly, the second external electrode and the protruding end surface of the lead frame may be connected by a conductive paste layer or a metal layer.

[0075] As described above, by carrying out the first to fifth steps, a solid electrolytic capacitor according to an embodiment of the present disclosure can be obtained.

[0076] In the method for manufacturing a solid electrolytic capacitor according to an embodiment of the present disclosure, a single metal plate on which multiple lead frames are formed may be used. Specifically, a single metal plate on which multiple lead frames are formed so as to be aligned in the length and width directions may be used. By using a single metal plate on which multiple lead frames are formed, multiple sealed bodies can be obtained at once by sealing the multiple lead frames and multiple laminates together on the single metal plate in the third step. The multiple sealed bodies can be individually cut out from the single metal plate by dicing or the like.

[0077] Although the present specification has described an example in which the solid electrolytic capacitor 100 includes a plurality of capacitor elements 10 as an embodiment, the solid electrolytic capacitor 100 may include only one capacitor element 10. Furthermore, the present specification has described an example in which the protruding end face of the anode portion 11 is exposed and electrically connected to the first external electrode 130 in the solid electrolytic capacitor 100 as an embodiment, but the electrical connection between the anode portion 11 and the first external electrode 130 is not limited to this. The anode portion 11 and the first external electrode 130 may be electrically connected via a lead frame.

[0078] (Additional Notes) The above description discloses the following techniques. (Technology 1) A capacitor element comprising: an exterior body having a rectangular parallelepiped shape, the exterior body including: a first end face and a second end face that face each other in a first direction; a top face and a bottom face that face each other in a second direction orthogonal to the first direction and that respectively connect the first end face and the second end face; and a first side face and a second side face that face each other in a third direction orthogonal to the first and second directions and that respectively connect the first end face and the second end face and the top face and the bottom face; an anode portion and a cathode portion, the capacitor element being sealed inside the exterior body; a lead frame electrically connected to the cathode portion and at least a portion of which is sealed in the exterior body; a first external electrode electrically connected to the anode portion at the first end face; and a second external electrode electrically connected to the lead frame at the second end face, the cathode portion having a solid electrolyte layer containing a conductive polymer, The lead frame has an overhanging portion at the second end surface that is exposed more from the bottom surface side than the top surface side, and is electrically connected to the second external electrode via the overhanging portion, and an R dimension or C dimension of an edge where the bottom surface and the second end surface overlap is smaller than an R dimension or C dimension of an edge where the bottom surface and the first side surface overlap. (Technology 2) The solid electrolytic capacitor according to Technology 1, wherein the R dimension or C dimension of an edge where the bottom surface and the second end surface overlap is smaller than an R dimension or C dimension of an edge where the bottom surface and the second side surface overlap. (Technology 3) The solid electrolytic capacitor according to Technology 1 or 2, wherein the R dimension or C dimension of an edge where the bottom surface and the second end surface overlap is smaller than an R dimension or C dimension of an edge where the second end surface and the first side surface overlap. (Technology 4) The solid electrolytic capacitor according to any one of Technologies 1 to 3, wherein an R dimension or a C dimension of an edge where the bottom surface and the second end face overlap is smaller than an R dimension or a C dimension of an edge where the second end face and the second side face overlap. (Technology 5) The solid electrolytic capacitor according to any one of Technologies 1 to 4, wherein the lead frame has a side wall portion extending along the second end face of the exterior body and facing an end face of the cathode portion in the first direction.(Technology 6) The solid electrolytic capacitor according to any one of Technologies 1 to 5, wherein the anode portion has a protruding end surface exposed at the first end surface of the exterior body and is electrically connected to the first external electrode via the protruding end surface, and wherein an R dimension or C dimension of an edge where the bottom surface and the first end surface overlap is smaller than an R dimension or C dimension of an edge where the bottom surface and the first side surface overlap. (Technology 7) The solid electrolytic capacitor according to Technology 6, wherein the R dimension or C dimension of an edge where the bottom surface and the first end surface overlap is smaller than an R dimension or C dimension of an edge where the bottom surface and the second side surface overlap. (Technology 8) The solid electrolytic capacitor according to Technology 6 or 7, wherein the R dimension or C dimension of an edge where the bottom surface and the first end surface overlap is smaller than an R dimension or C dimension of an edge where the first end surface and the first side surface overlap. (Technology 9) The solid electrolytic capacitor according to any one of Technologies 6 to 8, wherein an R dimension or C dimension of an edge where the bottom surface and the first end surface overlap is smaller than an R dimension or C dimension of an edge where the first end surface and the second side surface overlap. (Technology 10) The solid electrolytic capacitor according to any one of Technologies 1 to 9, wherein an R dimension or C dimension of an edge where the top surface and the second end surface overlap is smaller than an R dimension or C dimension of an edge where the top surface and the first side surface overlap. (Technology 11) The solid electrolytic capacitor according to any one of Technologies 1 to 10, wherein an R dimension or C dimension of an edge where the top surface and the second end surface overlap is smaller than an R dimension or C dimension of an edge where the top surface and the second side surface overlap. (Technology 12) The solid electrolytic capacitor according to any one of Technologies 1 to 11, wherein an R dimension or C dimension of an edge where the top surface and the second end face overlap is smaller than an R dimension or C dimension of an edge where the second end face and the first side face overlap. (Technology 13) The solid electrolytic capacitor according to any one of Technologies 1 to 12, wherein an R dimension or C dimension of an edge where the top surface and the second end face overlap is smaller than an R dimension or C dimension of an edge where the second end face and the second side face overlap. (Technology 14) The solid electrolytic capacitor according to any one of Technologies 6 to 13, wherein an R dimension or C dimension of an edge where the top surface and the first end face overlap is smaller than an R dimension or C dimension of an edge where the top surface and the first side face overlap.(Technology 15) The solid electrolytic capacitor according to any one of Technologies 6 to 14, wherein an R dimension or C dimension of an edge where the top surface and the first end face overlap is smaller than an R dimension or C dimension of an edge where the top surface and the second side face overlap. (Technology 16) The solid electrolytic capacitor according to any one of Technologies 6 to 15, wherein an R dimension or C dimension of an edge where the top surface and the first end face overlap is smaller than an R dimension or C dimension of an edge where the first end face and the first side face overlap. (Technology 17) The solid electrolytic capacitor according to any one of Technologies 6 to 16, wherein an R dimension or C dimension of an edge where the top surface and the first end face overlap is smaller than an R dimension or C dimension of an edge where the first end face and the second side face overlap.

[0079] While the present invention has been described in terms of presently preferred embodiments, such disclosure should not be interpreted as limiting. Various changes and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. It is therefore intended that the appended claims be interpreted to cover all changes and modifications that do not depart from the true spirit and scope of the invention.

[0080] The solid electrolytic capacitor according to the present disclosure can be used in applications where it is required to suppress oxidative degradation of conductive polymers.

[0081] 10: capacitor element, 11: anode portion, 12: dielectric layer, 13: solid electrolyte layer, 14: cathode lead layer, 15: cathode portion, 100: solid electrolytic capacitor, 110: lead frame, 111: side wall portion, 112: extension portion, 112A: first extension portion, 112B: second extension portion, 113: bottom plate portion, 120: exterior body, 130: first external electrode, 140: second external electrode, B: bottom surface, C: coated portion, D1: first direction, D2: second direction, D3: third direction, E1: first end face, E2: second end face, NC: uncoated portion, R: top surface, S: notch, S1: first side surface, S2: second side surface, Sa to S1: side, San: tip surface, Sca: end surface, Ss: tip surface, St: tip surface

Claims

1. A capacitor element comprising: a rectangular parallelepiped exterior housing having a first end face and a second end face that face each other in a first direction; a top face and a bottom face that face each other in a second direction perpendicular to the first direction and that respectively connect the first end face and the second end face; and a first side face and a second side face that face each other in a third direction perpendicular to the first and second directions and that respectively connect the first end face and the second end face and the top face and the bottom face; an anode portion and a cathode portion, the capacitor element being sealed inside the exterior housing; a lead frame that is electrically connected to the cathode portion and at least a portion of which is sealed in the exterior housing; a first external electrode that is electrically connected to the anode portion at the first end face; and a second external electrode that is electrically connected to the lead frame at the second end face; the cathode portion having a solid electrolyte layer containing a conductive polymer; the lead frame has a protrusion at the second end surface that is exposed more from the bottom surface side than from the top surface side, and is electrically connected to the second external electrode via the protrusion; and an R dimension or C dimension of the side where the bottom surface and the second end surface overlap is smaller than the R dimension or C dimension of the side where the bottom surface and the first side surface overlap.

2. The solid electrolytic capacitor according to claim 1, wherein the R dimension or C dimension of the side where the bottom surface and the second end surface overlap is smaller than the R dimension or C dimension of the side where the bottom surface and the second side surface overlap.

3. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the bottom surface and the second end face overlap is smaller than the R dimension or C dimension of the side where the second end face and the first side face overlap.

4. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the bottom surface and the second end surface overlap is smaller than the R dimension or C dimension of the side where the second end surface and the second side surface overlap.

5. The solid electrolytic capacitor according to claim 1 or 2, wherein the lead frame has a sidewall portion that extends along the second end face of the exterior body and faces the end face of the cathode portion in the first direction.

6. The solid electrolytic capacitor according to claim 1 or 2, wherein the anode portion has a pointed end surface exposed on the first end surface of the outer casing and is electrically connected to the first external electrode via the pointed end surface, and the R dimension or C dimension of the side where the bottom surface and the first end surface overlap is smaller than the R dimension or C dimension of the side where the bottom surface and the first side surface overlap.

7. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the bottom surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the bottom surface and the second side face overlap.

8. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the bottom surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the first end face and the first side face overlap.

9. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the bottom surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the first end face and the second side face overlap.

10. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the top surface and the second end face overlap is smaller than the R dimension or C dimension of the side where the top surface and the first side face overlap.

11. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the top surface and the second end face overlap is smaller than the R dimension or C dimension of the side where the top surface and the second side face overlap.

12. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the top surface and the second end face overlap is smaller than the R dimension or C dimension of the side where the second end face and the first side face overlap.

13. The solid electrolytic capacitor according to claim 1 or 2, wherein the R dimension or C dimension of the side where the top surface and the second end face overlap is smaller than the R dimension or C dimension of the side where the second end face and the second side face overlap.

14. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the top surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the top surface and the first side face overlap.

15. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the top surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the top surface and the second side face overlap.

16. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the top surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the first end face and the first side face overlap.

17. The solid electrolytic capacitor according to claim 6, wherein the R dimension or C dimension of the side where the top surface and the first end face overlap is smaller than the R dimension or C dimension of the side where the first end face and the second side face overlap.

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