Electrolytic capacitor

Abstract

In the present invention, the disclosed electrolytic capacitor includes at least one capacitor element (100), a first lead terminal (20) and a second lead terminal connected to the capacitor element (100), and an exterior body (40) covering a part of the first lead terminal (20), a part of the second lead terminal, and the at least one capacitor element. The first lead terminal (20) includes a buried portion (21) buried in the exterior body and a exposed portion (22) exposed from the exterior body (40). The first lead terminal (20) has two main surfaces and a lead side surface (20Ls) connecting the two main surfaces. The exterior body (40) has a first end surface (40Pe1) on which the exposed portion of the first lead terminal (20) protrudes and a second end surface on the opposite side of the first end surface (40Pe1). The buried portion (21) includes a protruding portion (21X) protruding from the lead side surface (20Ls).

Description

Cross-references to related applications

[0001] This disclosure claims the benefit of priority to Japanese Patent Application No. 2024-053525, filed on March 28, 2024, with the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to electrolytic capacitors. Background Technology

[0003] An electrolytic capacitor comprises a capacitor element, lead terminals connected to the capacitor element, and an outer casing covering the capacitor element. Various designs have been proposed for electrolytic capacitors in the past.

[0004] Claim 1 of Patent Document 1 (Japanese Patent Application Publication No. 2011-91444) discloses "an electrolytic capacitor having an anode portion and a cathode portion, wherein the anode portion is formed by sequentially stacking a dielectric oxide film, a solid electrolyte layer, and a cathode layer on the surface of the anode portion having an anode lead and including a valve metal to form a capacitor element; multiple such capacitor elements are stacked, and the anode lead portions of the capacitor elements are joined to obtain the anode portion; the cathode portion is formed by joining the cathode layer of the capacitor element with a conductive sheet in between, wherein the conductive sheet is formed of a film mixed with conductive filler and binder resin, and has a volume resistivity of 10.0 × 10⁻⁶." -4 Below Ω·cm.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-91444 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In electrolytic capacitors, it is required to suppress degradation. One of the objectives of this disclosure is to provide electrolytic capacitors with less degradation.

[0010] Methods for solving problems

[0011] One aspect of this disclosure relates to an electrolytic capacitor comprising:

[0012] At least one capacitor element;

[0013] The first lead terminal and the second lead terminal are connected to the at least one capacitor element; and

[0014] An outer casing that covers a portion of the first lead terminal, a portion of the second lead terminal, and the at least one capacitor element.

[0015] The first lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing.

[0016] The first lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces.

[0017] The outer casing has a first end face Pe1 protruding from the exposed portion of the first lead terminal and a second end face Pe2 on the opposite side of the first end face Pe1.

[0018] The embedded portion includes a protrusion that protrudes from the side Ls of the lead wire.

[0019] Invention Effects

[0020] According to this disclosure, electrolytic capacitors with less degradation can be obtained.

[0021] The novel features of the invention are set forth in the appended claims; however, the invention should be more fully understood, in both its structure and content, together with its other objects and features, by referring to the following detailed description of the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view schematically illustrating an example of an electrolytic capacitor according to Embodiment 1.

[0023] Figure 2 yes Figure 1 The top view of the electrolytic capacitor shown.

[0024] Figure 3 This is a cross-sectional view schematically representing an example of a capacitor element.

[0025] Figure 4 It is a schematic representation Figure 1 A diagram showing a portion of an electrolytic capacitor.

[0026] Figure 5 It is a schematic representation Figure 1 A top view of a portion of the electrolytic capacitor shown.

[0027] Figure 6 It is a schematic representation Figure 1 A top view of an example of the first lead terminal used in the electrolytic capacitor shown. Detailed Implementation

[0028] The following description illustrates embodiments of this disclosure using examples, but this disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials are sometimes illustrated, but other numerical values ​​and materials can be applied as long as the effects of this disclosure are achieved. In this specification, the phrase "numerical value A to numerical value B" includes both numerical value A and numerical value B, and can be understood as "numerical value A or higher and numerical value B or lower." In the following description, when lower and upper limits of numerical values ​​related to specific physical properties, conditions, etc., are illustrated, any of the illustrated lower limits can be arbitrarily combined with any of the illustrated upper limits, as long as the lower limit is not higher than the upper limit. In the following description, when examples of constituent elements are listed, unless specifically mentioned, only one of the listed examples can be used, or multiple listed examples can be used together.

[0029] (Electrolytic capacitor)

[0030] Hereinafter, the electrolytic capacitor of this embodiment will sometimes be referred to as "electrolytic capacitor (C)" or "capacitor (C)". The capacitor (C) includes at least one capacitor element, a first lead terminal and a second lead terminal connected to the at least one capacitor element, and an outer casing covering a portion of the first lead terminal, a portion of the second lead terminal, and the at least one capacitor element. The first lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing. The first lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces. The outer casing has a first end surface Pe1 protruding from the exposed portion of the first lead terminal and a second end surface Pe2 opposite to the first end surface Pe1. The embedded portion includes a protrusion protruding from the lead side surface Ls.

[0031] The protrusion may protrude onto the surface of the outer casing. Preferably, the protrusion does not protrude from the outer casing. By preventing the protrusion from protruding from the outer casing, water and oxygen can be prevented from entering through the interface between the protrusion and the outer casing.

[0032] Electrolytic capacitors require long lifespans, especially at high temperatures. The capacitor element is enclosed in a casing. However, if the casing's airtightness decreases, the capacitor element will deteriorate due to the intrusion of water, oxygen, and other contaminants, leading to an increase in the equivalent series resistance (ESR). Therefore, maintaining the airtightness of the casing is crucial to suppressing electrolytic capacitor degradation.

[0033] One of the main reasons for reduced hermeticity of the casing is decreased seal between the lead terminals and the casing. For example, tensile stress is applied to the lead terminals during the assembly of electrolytic capacitors, which can sometimes lead to a reduced seal between the lead terminals and the casing. Additionally, if the electrolytic capacitor is heated during the reflow soldering process when mounting it onto the substrate, the moisture inside the capacitor can expand, reducing the seal between the lead terminals and the casing. Furthermore, temperature variations during the use of electrolytic capacitors can sometimes cause a decrease in the seal between the lead terminals and the casing.

[0034] As a result of their research, the inventors of this application discovered that by changing the shape of the lead terminals, they were able to suppress the reduction in the seal between the lead terminals and the outer casing. This disclosure is based on this new insight.

[0035] The capacitor (C) has protrusions in the embedded portions of its lead terminals. These protrusions prevent misalignment between the casing and the lead terminals. As a result, the seal between the casing and the lead terminals is improved. Furthermore, even with stresses generated during the manufacturing of the electrolytic capacitor or stresses caused by temperature changes, the anchoring effect of the protrusions helps to suppress any decrease in the seal between the lead terminals and the casing. Additionally, the length of the protrusions on the sides of the capacitor (C)'s lead terminals increases. This, in turn, prevents moisture or oxygen from reaching the capacitor element through the interface between the side of the lead terminals and the casing. Thus, based on the configuration of the capacitor (C), degradation can be suppressed.

[0036] The number N of capacitor elements contained in a capacitor (C) is not particularly limited. The number N of capacitor elements contained in a capacitor (C) can be 1 or more. There is no particular upper limit to the number N, which can be 10 or less. When a capacitor (C) contains multiple capacitor elements, the multiple capacitor elements can be stacked in parallel.

[0037] The embedded portion may include a connection portion that is directly or indirectly connected to at least one capacitor element, and a lead portion that connects the connection portion to the exposed portion. A protrusion may protrude from the lead side Ls of the lead portion.

[0038] The connector is connected to the capacitor element directly or indirectly. Examples of direct connection include connections where the connector is soldered to a portion of the capacitor element. Examples of indirect connection include connections where the connector is connected to the capacitor element via a conductive layer. Examples of conductive layers include carbon layers, metal particle layers (e.g., silver particle layers), etc.

[0039] The lead side Ls includes a first lead side Ls1 and a second lead side Ls2. The protrusion may include a first protrusion protruding from the first lead side Ls1 and a second protrusion protruding from the second lead side Ls2. By having two protrusions in the embedded portion, the fit between the outer casing and the lead terminal is particularly improved. The first and second protrusions may protrude symmetrically. It should be noted that the lead side Ls on the first side Ps1 (described later) can be considered the first lead side Ls1, and the lead side Ls on the second side Ps2 (described later) can be considered the second lead side Ls2.

[0040] The exposed portion may include a terminal portion for connection to an external circuit. The outer casing may have a first end face Pe1, a second end face Pe2, a bottom surface where the terminal portion is disposed, a top surface opposite the bottom surface, and a first side surface Ps1 and a second side surface Ps2 connecting the first end face Pe1 and the second end face Pe2. In this case, the outer casing may have a generally cuboid shape. The first protrusion may protrude toward the first side surface Ps1, and the second protrusion may protrude toward the second side surface Ps2. In this configuration, bending of the protrusions is unnecessary. Furthermore, according to this configuration, the distance between the top and bottom surfaces of the outer casing and the protrusions is easily ensured.

[0041] The planar shape of the protrusion (the shape of the main surface of the protrusion) is not particularly limited. The planar shape of the protrusion can be rectangular, triangular, trapezoidal, or any other shape.

[0042] The protrusion has two main surfaces and a side surface Xs connecting the two main surfaces. The side surface Xs may have a first side surface Xs1 on the side of the first end surface Pe1 and a second side surface Xs2 on the side of the second end surface Pe2.

[0043] The distance between the first side surface Xs1 and the first end face Pe1 increases as it moves away from the lead side surface Ls adjacent to the protrusion (more specifically, the first side surface Xs1 of the protrusion). With this configuration, cracking between the first side surface Xs1 and the first end face Pe1 can be suppressed. In this case, the distance between the first side surface Xs1 and the first end face Pe1 can increase continuously as it moves away from the lead side surface Ls adjacent to the protrusion. Alternatively, the distance between the first side surface Xs1 and the first end face Pe1 can increase in a stepped manner as it moves away from the lead side surface Ls adjacent to the protrusion.

[0044] The angle α1 between the lead wire side Ls adjacent to the protrusion (more specifically, the first side Xs1 of the protrusion) and the first side Xs1 can be 160° or less or 140° or less. By setting the angle α1 to 160° or less, the anchoring effect of the protrusion can be particularly improved.

[0045] The angle α1 can be 90° or more, 130° or more, or 150° or more. By setting the angle α1 to 130° or more, it is possible to particularly suppress the generation of cracks on the outer casing between the first side surface Xs1 and the first end face Pe1, or the peeling between the outer casing and the first lead terminal. When the angle α1 is greater than 90°, the distance between the first side surface Xs1 and the first end face Pe1 increases as it moves away from the lead side surface Ls adjacent to the protrusion.

[0046] The angle β1 between the lead wire side Ls adjacent to the protrusion (more specifically, the second side Xs2 of the protrusion) and the second side Xs2 can be 90° or less or 70° or less. By setting the angle β1 to 90° or less, a high anchoring effect can be obtained. As a result, the fit between the outer casing and the lead wire terminal is improved. The angle β1 can be 90°.

[0047] The distance between the second side Xs2 and the first end face Pe1 increases as it moves away from the lead wire side Ls adjacent to the protrusion (more specifically, the second side Xs2 of the protrusion). With this configuration, a particularly high anchoring effect can be obtained. In this case, the distance between the second side Xs2 and the first end face Pe1 increases continuously as it moves away from the lead wire side Ls adjacent to the protrusion. Alternatively, the distance between the second side Xs2 and the first end face Pe1 can increase in a stepped manner as it moves away from the lead wire side Ls adjacent to the protrusion.

[0048] The aforementioned angle β1 can be 60° or greater, or 80° or greater. By setting the angle β1 to 60° or greater, the formation based on the punching process becomes easier.

[0049] The coefficient of thermal expansion of the outer casing at 110°C can be less than that of the first lead terminal at 110°C. This configuration helps to suppress the decrease in the seal between the outer casing and the lead terminal caused by temperature changes. Similarly, the coefficient of thermal expansion of the outer casing at 110°C can be less than that of the second lead terminal (described later) at 110°C. The coefficient of thermal expansion of the outer casing can be varied depending on the type of material (resin, inorganic filler, etc.) constituting the outer casing. The coefficient of thermal expansion of the lead terminal can be varied depending on the type of metal constituting the lead terminal. It should be noted that the coefficient of thermal expansion of the outer casing at 110°C can be greater than or equal to the coefficient of thermal expansion of the lead terminals (first lead terminal, second lead terminal) at 110°C. In this specification, the coefficient of thermal expansion refers to the linear coefficient of thermal expansion.

[0050] The second lead terminal may include an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing. The exposed portion of the second lead terminal may protrude from the second end face Pe2. The second lead terminal may have two main faces and a lead side Ls connecting the two main faces.

[0051] The embedded portion of the second lead terminal may include a protrusion extending from the lead side of the second lead terminal. That is, the second lead terminal may have a protrusion similar to that of the first lead terminal. The details described for the protrusion of the first lead terminal can be applied to the protrusion of the second lead terminal, therefore, repeated descriptions are omitted. However, when applying the details described for the shape of the protrusion of the first lead terminal to the second lead terminal, the first end face Pe1 is replaced by the second end face Pe2, and the second end face Pe2 is replaced by the first end face Pe1. The shape of the protrusion of the first lead terminal may be the same as or different from the shape of the protrusion of the second lead terminal.

[0052] The embedded portion of the second lead terminal may include a connection portion that is directly or indirectly connected to at least one capacitor element, and a lead portion that connects the connection portion to the exposed portion. The protrusion of the second lead terminal may protrude from the lead side Ls of the lead portion of the second lead terminal.

[0053] The lead side Ls of the second lead terminal may include a first lead side Ls1 and a second lead side Ls2. The protrusion of the second lead terminal may include a first protrusion protruding from the first lead side Ls1 of the second lead terminal and a second protrusion protruding from the second lead side Ls2 of the second lead terminal.

[0054] The exposed portion of the second lead terminal may include a terminal portion for connection to an external circuit. The outer casing may have a first end face Pe1, a second end face Pe2, a bottom surface on which the terminal portion is disposed, a top surface opposite the bottom surface, and a first side surface Ps1 and a second side surface Ps2 connecting the first end face Pe1 and the second end face Pe2. The first protrusion of the second lead terminal may protrude toward the first side surface Ps1. The second protrusion of the second lead terminal may protrude toward the second side surface Ps2.

[0055] The planar shape of the protrusion of the second lead terminal can be triangular.

[0056] The protrusion of the second lead terminal may have two main surfaces and a side surface Xs connecting the two main surfaces. The side surface Xs of the second lead terminal may have a first side surface Xs1 on the second end surface Pe2 and a second side surface Xs2 on the first end surface Pe1.

[0057] The distance between the first side surface Xs1 of the second lead terminal and the second end face Pe2 increases as the lead side surface Ls of the second lead terminal, which is adjacent to the protrusion of the second lead terminal (more specifically, the first side surface Xs1 of the protrusion), moves away from the protrusion of the second lead terminal.

[0058] The angle α2 between the lead side Ls of the second lead terminal adjacent to the protrusion of the second lead terminal (more specifically, the first side Xs1 of the protrusion) and the first side Xs1 of the second lead terminal can be 160° or less. Similarly to angle α1, angle α2 can be 90° or more, 130° or more, or 150° or more.

[0059] The angle β2 between the lead side Ls of the second lead terminal adjacent to the protrusion of the second lead terminal (more specifically, the second side Xs2 of the protrusion) and the second side Xs2 of the second lead terminal can be 90° or less.

[0060] The angle β2 of the second lead terminal can be 60° or higher.

[0061] The coefficient of thermal expansion of the outer casing at 110°C can be less than that of the second lead terminal at 110°C.

[0062] The following describes examples of the constituent elements of the electrolytic capacitor of this disclosure, but the composition of the electrolytic capacitor (C) of this disclosure is not limited to the composition illustrated below. Except for the parts unique to the electrolytic capacitor (C), the constituent elements of the electrolytic capacitor (C) may use the constituent elements known to be used in electrolytic capacitors (C).

[0063] An electrolytic capacitor (C) includes at least one capacitor element, lead terminals (anode lead terminals and cathode lead terminals), and an outer casing. The capacitor element includes an anode portion, a dielectric layer, and a cathode portion. The dielectric layer is formed on the surface of the anode portion. The anode lead terminals are connected to the anode portion. The cathode lead terminals are connected to the cathode portion.

[0064] One of the anode lead terminal and the cathode lead terminal is the first lead terminal, and the other is the second lead terminal. The protrusion may be formed only on the anode lead terminal, or only on the cathode lead terminal. Alternatively, the protrusion may be formed on both the anode lead terminal and the cathode lead terminal.

[0065] (Anode section)

[0066] The anode section includes an anode body. The anode body can be a foil (metal foil) containing a valve metal. Examples of valve metals include titanium, tantalum, aluminum, and niobium. Aluminum foil can be used for the anode body. The thickness of the anode body is not particularly limited. The thickness of the anode body can be in the range of 15–300 μm (e.g., 80–250 μm).

[0067] At least a portion of the surface of the anode (e.g., aluminum foil) can be roughened by electrolytic etching or the like. In this case, the anode has a porous structure on its surface.

[0068] (Dielectric layer)

[0069] A dielectric layer is formed on at least a portion of the surface of the anode body. The dielectric layer can be formed by anodizing the surface of the anode body (e.g., anodizing based on a chemical conversion process). In this case, the dielectric layer comprises an oxide of the valve metal. For example, when using aluminum foil as the anode body, an aluminum oxide layer (dielectric layer) is formed on the surface of the aluminum foil by anodizing it.

[0070] (Cathode section)

[0071] The cathode portion includes an electrolyte layer (solid electrolyte layer) and a cathode lead-out layer adjacent to the electrolyte layer. The cathode lead-out layer may be formed to cover at least a portion of the electrolyte layer, or it may be formed to cover the entire surface of the electrolyte layer.

[0072] The electrolyte layer (solid electrolyte layer) is configured to cover at least a portion of the dielectric layer. Alternatively, the electrolyte layer may be configured to cover the entire surface of the dielectric layer.

[0073] The electrolyte layer can be formed from manganese compounds, conductive polymers, etc. Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyphenylene vinylidene, polyphenylene, polythiophene vinylidene, and their derivatives. A preferred example of a conductive polymer includes poly(3,4-ethylenedioxythiophene).

[0074] Conductive polymers can be doped with dopants. Dopants can be polymeric dopants. Examples of polymeric dopants include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polypropylene sulfonic acid, polymethylpropylene sulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprene sulfonic acid, polyacrylic acid, etc. A preferred example of a dopant is polystyrene sulfonic acid (PSS). A preferred example of an electrolyte layer is formed using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrene sulfonic acid (PSS).

[0075] An electrolyte layer containing conductive polymers can be formed using known methods. Alternatively, the electrolyte layer can be formed by contacting an anode with a dielectric layer in a solution or dispersion of conductive polymers followed by drying. Alternatively, the electrolyte layer can be formed on the surface of the dielectric layer using chemical polymerization or electrolytic polymerization.

[0076] The cathode lead-out layer can use a conductive layer. Examples of conductive layers include carbon layers, metal-containing layers, etc. The metal-containing layer can be a layer of metal particles (e.g., a silver particle layer). The metal particle layer can be formed using a metal paste (e.g., a silver paste). The cathode lead-out layer can consist of multiple layers. For example, the cathode lead-out layer can include a carbon layer formed on an electrolyte layer and a metal particle layer (e.g., a silver particle layer) formed on the carbon layer. The cathode lead-out layer can be formed using known methods. For example, the material coated with the cathode lead-out layer can be dried and / or heat-treated as needed.

[0077] (outer body)

[0078] The outer casing contains an outer resin. Examples of outer resins include curable resins and engineering plastics. Examples of curable resins (e.g., thermosetting resins) include epoxy resins, phenolic resins, silicone resins, melamine resins, urea resins, alkyd resins, polyurethanes, and unsaturated polyesters. Engineering plastics include general-purpose engineering plastics and super engineering plastics. Examples of engineering plastics include polyimide and polyamide-imide.

[0079] In addition to the outer resin, the outer casing may also contain other additives such as inorganic fillers. That is, at least a portion of the outer casing may be composed of a resin composition. Examples of inorganic fillers include silica (fused silica, etc.), talc, calcium carbonate, alumina, etc.

[0080] (Lead terminals)

[0081] As described above, the specified lead terminals have protrusions. The first and second lead terminals can each be formed by processing a single sheet of metal. That is, the protrusions and the lead portion can be formed as a single unit. The material of the lead terminals (anode and cathode lead terminals) is not particularly limited as long as they are electrochemically and chemically stable and conductive. Lead terminals are typically made of metal (e.g., iron alloys, copper, copper alloys, etc.). The surface of the lead terminals can be plated. The thickness of the lead terminals can be in the range of 25 μm to 200 μm (e.g., 25 μm to 100 μm).

[0082] (An example of a manufacturing method for electrolytic capacitors)

[0083] The manufacturing method of the electrolytic capacitors in this embodiment is not particularly limited. Known manufacturing methods can be used, or a portion of a known manufacturing method can be modified based on the configuration of the electrolytic capacitors in this embodiment.

[0084] In one example manufacturing method, firstly, anode and cathode leads are formed by stamping a metal sheet. During this process, stamping is performed to form protrusions on the leads. Next, the leads are bent into a predetermined shape. Then, the connecting portions of the anode and cathode leads are respectively connected to a capacitor element. The connection can be made by welding or via a conductive layer. Next, a portion of the leads and the capacitor element are sealed with an outer casing. This sealing with the outer casing can be achieved through transfer molding or the like. Finally, the exposed portions of the leads are cut and bent as needed. Thus, an electrolytic capacitor is manufactured.

[0085] Hereinafter, examples of embodiments of the present disclosure will be specifically described with reference to the accompanying drawings. The constituent elements of the examples described below can be applied to the constituent elements described above. Furthermore, the examples described below can be modified based on the above description. Additionally, the matters described below can be applied to the embodiments described above. Furthermore, in the embodiments described below, constituent elements that are not essential for the electrolytic capacitor of the present disclosure can be omitted. It should be noted that, for ease of viewing the accompanying drawings, some parts are sometimes omitted from the illustrations in the following figures. Also, for ease of illustration in the following figures, the scale of some parts is sometimes changed.

[0086] (Implementation Method 1)

[0087] Figure 1 This is a schematic cross-sectional view of the electrolytic capacitor 10 of Embodiment 1. Figure 2 This is a schematic top view of the electrolytic capacitor 10. In Embodiment 1, an example where the first lead terminal is an anode lead terminal and the second lead terminal is a cathode lead terminal will be described. As mentioned above, the first lead terminal may also be a cathode lead terminal and the second lead terminal may be an anode lead terminal. In Embodiment 1, an example where both the first and second leads terminal have protrusions will be described.

[0088] The electrolytic capacitor 10 includes four capacitor elements 100, a first lead terminal (anode lead terminal) 20, a second lead terminal (cathode lead terminal) 30, and an outer casing 40. The anode portions 110 of the four capacitor elements 100 converge and are connected to the first lead terminal 20. The cathode portions 130 of the four capacitor elements 100 are interconnected and further connected to the second lead terminal 30 via a conductive layer 51. It should be noted that in Figure 1 For ease of observation, the dielectric layer is omitted from the accompanying drawings. The outer casing 40 seals a portion of the first lead terminal 20, a portion of the second lead terminal 30, and the capacitor element 100.

[0089] Four capacitor elements 100 are stacked in the direction connecting the bottom surface 40Pb and the top surface 40Pt of the outer casing 40. The cathode portions 130 of the four capacitor elements 100 can be connected to each other through conductive layers or the like. The anode portions 110 of the four capacitor elements 100 can be connected to each other through welding or the like.

[0090] The first lead terminal 20 is formed from a metal sheet. The first lead terminal 20 includes an embedded portion 21 embedded in the outer casing 40 and an exposed portion 22 protruding from the outer casing 40. The embedded portion 21 includes a connection portion 21a that is directly or indirectly connected to the anode portion 110 (capacitor element 100) and a lead portion 21b that connects the connection portion 21a to the exposed portion 22. The exposed portion 22 includes a terminal portion 22a that connects to an external circuit and an exposed lead portion 22b that connects the terminal portion 22a to the embedded portion 21. The terminal portion 22a is the portion that connects to an external circuit. For example, the terminal portion 22a may be a portion soldered to a circuit board. The connection portion 21a may include two blade portions arranged to surround the side of the end of the anode portion 110. The embedded portion 21 includes two protrusions 21X protruding into the surface of the outer casing 40.

[0091] The second lead terminal 30 is formed from a metal sheet. The second lead terminal 30 includes an embedded portion 31 embedded in the outer casing 40 and an exposed portion 32 protruding from the outer casing 40. The embedded portion 31 includes a connection portion 31a indirectly connected to the cathode portion 130 (capacitor element 100) via a conductive layer 51, and a lead portion 31b connecting the connection portion 31a to the exposed portion 32. The exposed portion 32 includes a terminal portion 32a connected to an external circuit and an exposed lead portion 32b connecting the terminal portion 32a to the embedded portion 31. The terminal portion 32a is a portion that is soldered, etc. The connection portion 31a may include two blade portions arranged to surround the side of the cathode portion 130. The embedded portion 31 includes two protrusions 31X protruding into the surface of the outer casing 40.

[0092] The outer casing 40 has a cuboid shape. (See reference) Figure 1 and Figure 2 The outer casing 40 has a first end face 40Pe1, a second end face 40Pe2, a bottom face 40Pb, a top face 40Pt, a first side face 40Ps1, and a second side face 40Ps2. The first end face 40Pe1 is the surface from which the first lead terminal 20 protrudes. The second end face 40Pe2 is the surface from which the second lead terminal 30 protrudes. The bottom face 40Pb is the surface on which terminal portions 22a and 32a are disposed. The first side face 40Ps1 and the second side face 40Ps2 are the surfaces that connect the first end face 40Pe1 and the second end face 40Pe2, and are also the surfaces that connect the bottom face 40Pb and the top face 40Pt.

[0093] A cross-sectional view of an example of capacitor element 100 is schematically shown in Figure 3 The capacitor element 100 includes an anode portion (anode body) 110, a dielectric layer 120 covering at least a portion of the anode portion 110, and a cathode portion 130 covering at least a portion of the dielectric layer 120. The cathode portion 130 includes a solid electrolyte layer 131 covering at least a portion of the dielectric layer 120 and a cathode lead-out layer 132 formed on the solid electrolyte layer 131. The cathode lead-out layer 132 includes a carbon layer 132a and a silver particle layer 132b sequentially stacked from the solid electrolyte layer 131 side.

[0094] A partial enlarged view of the embedded portion 21 of the first lead terminal 20 is schematically shown. Figure 4 .Will Figure 4 The partial top view shown is schematically illustrated. Figure 5 In addition, Figure 5 The top view of the first lead terminal 20 shown is shown in Figure 6 .exist Figure 5 The direction LD connecting the first end face 40Pe1 and the second end face 40Pe2, and the direction WD connecting the first side face 40Ps1 and the second side face 40Ps2 are shown.

[0095] Reference Figure 4 The first lead terminal 20 has main surfaces 20Lp1 and 20Lp2, and a lead side surface 20Ls connecting these two main surfaces. (Refer to...) Figure 5 and Figure 6 The lead side 20Ls includes the first lead side 20Ls1 on the first side 40Ps1 side of the outer body 40 and the second lead side 20Ls2 on the second side 40Ps2 side of the outer body 40.

[0096] The first lead terminal 20 has two protrusions 21X that protrude from the lead side 20Ls toward the surface of the outer casing 40. Specifically, the first lead terminal 20 has a first protrusion 21X1 protruding toward a first side 40Ps1 of the outer casing 40 and a second protrusion 21X2 protruding toward a second side 40Ps2 of the outer casing 40. The first protrusion 21X1 protrudes from the first lead side 20Ls1 of the first lead terminal 20. The second protrusion 21X2 protrudes from the second lead side 20Ls2 of the first lead terminal 20. The protrusions 21X are generally not bent.

[0097] Reference Figure 6 A protrusion 21X has two main surfaces 21Xp and a side surface 21Xs connecting the two main surfaces 21Xp. It should be noted that... Figure 6 There is another main surface 21Xp on the opposite side of the main surface 21Xp shown on the top side. The side surface 21Xs has a first side surface 21Xs1 on the side of the first end surface 40Pe1 and a second side surface 21Xs2 on the side of the second end surface 40Pe2.

[0098] exist Figure 6 In one example shown, the first side surface 21Xs1 is inclined such that the distance from the first end face Pe1 increases as it moves away from the lead side surface 20Ls adjacent to the protrusion 21X. The angle α1 between the lead side surface 20Ls adjacent to the protrusion 21X and the first side surface 21Xs1 can be within the aforementioned range. The angle α1' between the surface parallel to the first end face 40Pe1 and the surface containing the first side surface 21Xs1 is represented by (α1-90°) (here, α1 can be set as an angle within the aforementioned range). In other words, the first side surface 21Xs1 is a surface obtained by inclining (α1-90°) the surface parallel to the first end face 40Pe1.

[0099] exist Figure 6 The diagram shows an example where the first side 21Xs1 extends from the boundary between the embedded portion 21 and the exposed portion 22. However, the first side 21Xs1 of the protrusion 21X may also protrude from the lead side 20Ls inside the outer casing 40.

[0100] exist Figure 6 In one example shown, the second side surface 21Xs2 is inclined such that the distance from the first end face Pe1 increases as it moves away from the lead side surface 20Ls adjacent to the protrusion 21X. The angle β1 between the lead side surface 20Ls and the second side surface 21Xs2 can be within the aforementioned range. The angle β1' between the surface parallel to the first end face 40Pe1 and the second side surface 21Xs2 is represented by (90°-β1) (here, β1 can be set as an angle within the aforementioned range). In other words, the second side surface 21Xs2 is a surface obtained by inclining (90°-β1) the surface parallel to the first end face 40Pe1.

[0101] The protrusion 31X can be the same shape as the protrusion 21X, or it can be a different shape. Because the lead terminals of the electrolytic capacitor 10 have protrusions, the above-mentioned effect can be achieved.

[0102] (Postscript)

[0103] The following technologies are disclosed through the above description.

[0104] (Technology 1)

[0105] An electrolytic capacitor comprising:

[0106] At least one capacitor element;

[0107] The first lead terminal and the second lead terminal are connected to the at least one capacitor element; and

[0108] An outer casing that covers a portion of the first lead terminal, a portion of the second lead terminal, and the at least one capacitor element.

[0109] The first lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing.

[0110] The first lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces.

[0111] The outer casing has a first end face Pe1 protruding from the exposed portion of the first lead terminal and a second end face Pe2 on the opposite side of the first end face Pe1.

[0112] The embedded portion includes a protrusion that protrudes from the side Ls of the lead wire.

[0113] (Technology 2)

[0114] According to the electrolytic capacitor described in Technique 1, wherein,

[0115] The embedded portion includes a connection portion that is directly or indirectly connected to the at least one capacitor element and a lead portion that connects the connection portion to the exposed portion.

[0116] The protrusion protrudes from the lead side Ls of the lead portion.

[0117] (Technology 3)

[0118] According to the electrolytic capacitor described in technique 1 or 2, wherein,

[0119] The lead side Ls includes a first lead side Ls1 and a second lead side Ls2.

[0120] The protrusion includes a first protrusion protruding from the side Ls1 of the first lead and a second protrusion protruding from the side Ls2 of the second lead.

[0121] (Technology 4)

[0122] According to the electrolytic capacitor described in Technique 3, wherein,

[0123] The exposed portion includes a terminal portion that connects to external circuitry.

[0124] The outer casing has a first end face Pe1, a second end face Pe2, a bottom surface on which the terminal portion is disposed, a top surface on the opposite side of the bottom surface, and a first side surface Ps1 and a second side surface Ps2 connecting the first end face Pe1 and the second end face Pe2.

[0125] The first protrusion protrudes toward the first side surface Ps1.

[0126] The second protrusion protrudes toward the second side surface Ps2.

[0127] (Technology 5)

[0128] According to any one of the techniques 1 to 4, the electrolytic capacitor wherein,

[0129] The planar shape of the protrusion is triangular.

[0130] (Technology 6)

[0131] According to any one of the techniques 1 to 5, the electrolytic capacitor wherein,

[0132] The protrusion has two main surfaces and a side surface Xs connecting the two main surfaces.

[0133] The side surface Xs has a first side surface Xs1 on the first end face Pe1 side and a second side surface Xs2 on the second end face Pe2 side.

[0134] (Technology 7)

[0135] According to the electrolytic capacitor described in Technique 6, wherein,

[0136] The distance between the first side surface Xs1 and the first end face Pe1 increases as the distance moves away from the lead side surface Ls adjacent to the protrusion.

[0137] (Technology 8)

[0138] According to the electrolytic capacitor described in Technique 6 or 7, wherein,

[0139] The angle α1 between the lead wire side surface Ls adjacent to the protrusion and the first side surface Xs1 is less than 160°.

[0140] (Technology 9)

[0141] According to any one of the techniques 6 to 8, the electrolytic capacitor wherein,

[0142] The angle β1 between the lead side Ls adjacent to the protrusion and the second side Xs2 is less than 90°.

[0143] (Technology 10)

[0144] According to the electrolytic capacitor described in Technique 9, wherein,

[0145] The angle β1 is 60° or more.

[0146] (Technology 11)

[0147] According to any one of the techniques 1 to 10, the electrolytic capacitor wherein,

[0148] The coefficient of thermal expansion of the outer casing at 110°C is less than that of the first lead terminal at 110°C.

[0149] (Technology 12)

[0150] According to any one of the techniques 1 to 11, the electrolytic capacitor wherein,

[0151] The second lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing.

[0152] The exposed portion of the second lead terminal protrudes from the second end face Pe2.

[0153] The second lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces.

[0154] The embedded portion of the second lead terminal includes a protrusion that protrudes from the lead side Ls of the second lead terminal.

[0155] (Technology 13)

[0156] According to the electrolytic capacitor described in Technique 12, wherein,

[0157] The embedded portion of the second lead terminal includes a connection portion that is directly or indirectly connected to the at least one capacitor element and a lead portion that connects the connection portion to the exposed portion.

[0158] The protrusion of the second lead terminal protrudes from the lead side Ls of the lead portion of the second lead terminal.

[0159] (Technology 14)

[0160] According to the electrolytic capacitor described in Technique 12 or 13, wherein,

[0161] The lead side Ls of the second lead terminal includes a first lead side Ls1 and a second lead side Ls2.

[0162] The protrusion of the second lead terminal includes a first protrusion protruding from the side Ls1 of the first lead of the second lead terminal and a second protrusion protruding from the side Ls2 of the second lead of the second lead terminal.

[0163] (Technology 15)

[0164] According to the electrolytic capacitor described in Technique 14, wherein,

[0165] The exposed portion of the second lead terminal includes a terminal portion that connects to an external circuit.

[0166] The outer casing has a first end face Pe1, a second end face Pe2, a bottom surface on which the terminal portion is disposed, a top surface on the opposite side of the bottom surface, and a first side surface Ps1 and a second side surface Ps2 connecting the first end face Pe1 and the second end face Pe2.

[0167] The first protrusion of the second lead terminal protrudes toward the first side surface Ps1.

[0168] The second protrusion of the second lead terminal protrudes toward the second side surface Ps2.

[0169] (Technology 16)

[0170] According to any one of the techniques 12 to 15, the electrolytic capacitor wherein,

[0171] The planar shape of the protrusion of the second lead terminal is triangular.

[0172] (Technology 17)

[0173] According to any one of techniques 12 to 16, the electrolytic capacitor wherein,

[0174] The protrusion of the second lead terminal has two main surfaces and a side surface Xs connecting the two main surfaces.

[0175] The side surface Xs of the second lead terminal has a first side surface Xs1 on the side of the second end face Pe2 and a second side surface Xs2 on the side of the first end face Pe1.

[0176] (Technology 18)

[0177] According to the electrolytic capacitor described in Technique 17, wherein,

[0178] The distance between the first side surface Xs1 of the second lead terminal and the second end face Pe2 increases as the distance moves away from the lead side surface Ls of the second lead terminal adjacent to the protrusion of the second lead terminal.

[0179] (Technology 19)

[0180] According to the electrolytic capacitor described in Technique 17 or 18, wherein,

[0181] The angle α2 formed by the lead side Ls of the second lead terminal adjacent to the protrusion of the second lead terminal and the first side Xs1 of the second lead terminal is 160° or less.

[0182] (Technology 20)

[0183] According to any one of the techniques 17 to 19, the electrolytic capacitor wherein,

[0184] The angle β2 formed by the lead side Ls of the second lead terminal adjacent to the protrusion of the second lead terminal and the second side Xs2 of the second lead terminal is 90° or less.

[0185] (Technology 21)

[0186] According to the electrolytic capacitor described in Technique 20, wherein,

[0187] The angle β2 of the second lead terminal is 60° or more.

[0188] (Technology 22)

[0189] According to any one of the techniques 12 to 21, the electrolytic capacitor wherein,

[0190] The coefficient of thermal expansion of the outer casing at 110°C is less than that of the second lead terminal at 110°C.

[0191] Industrial availability

[0192] This disclosure can be used for electrolytic capacitors.

[0193] Preferred embodiments of the present invention have been described, but such disclosure is not intended to be limiting. Various modifications and alterations will be readily apparent to those skilled in the art upon reading the foregoing disclosure. Therefore, the scope of the appended claims should be interpreted as including all modifications and alterations without departing from the true spirit and scope of the invention.

[0194] Explanation of reference numerals in the attached figures

[0195] 10: Electrolytic capacitors

[0196] 20: First lead terminal

[0197] 20Ls: Lead side

[0198] 20Ls1: Side of the first lead

[0199] 20Ls2: Side of the second lead

[0200] 21: Installation Department

[0201] 21a, 31a: Connecting parts

[0202] 21b, 31b: Lead wire section

[0203] 21X, 31X: Protrusions

[0204] 21X1: First protrusion

[0205] 21X2: Second protrusion

[0206] 21Xs1: First side

[0207] 21Xs2: Second side

[0208] 22, 32: Exposed areas

[0209] 22a, 32a: Terminal section

[0210] 30: Second lead terminal

[0211] 40: Exterior body

[0212] 40Pb: bottom surface

[0213] 40Pe1: First end face

[0214] 40Pe2: Second end face

[0215] 40Ps1: First side view

[0216] 40Ps2: Second side view

[0217] 40Pt: Top surface

[0218] 100: Capacitor element

Claims

1. An electrolytic capacitor comprising: At least one capacitor element; The first lead terminal and the second lead terminal are connected to the at least one capacitor element; and An outer casing that covers a portion of the first lead terminal, a portion of the second lead terminal, and the at least one capacitor element. The first lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing. The first lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces. The outer casing has a first end face Pe1 protruding from the exposed portion of the first lead terminal and a second end face Pe2 on the opposite side of the first end face Pe1. The embedded portion includes a protrusion that protrudes from the side Ls of the lead wire.

2. The electrolytic capacitor according to claim 1, wherein, The embedded portion includes a connection portion that is directly or indirectly connected to the at least one capacitor element and a lead portion that connects the connection portion to the exposed portion. The protrusion protrudes from the lead side Ls of the lead portion.

3. The electrolytic capacitor according to claim 1, wherein, The lead side Ls includes a first lead side Ls1 and a second lead side Ls2. The protrusion includes a first protrusion protruding from the side Ls1 of the first lead and a second protrusion protruding from the side Ls2 of the second lead.

4. The electrolytic capacitor according to claim 3, wherein, The exposed portion includes a terminal portion that connects to external circuitry. The outer casing has a first end face Pe1, a second end face Pe2, a bottom surface on which the terminal portion is disposed, a top surface on the opposite side of the bottom surface, and a first side surface Ps1 and a second side surface Ps2 connecting the first end face Pe1 and the second end face Pe2. The first protrusion protrudes toward the first side surface Ps1. The second protrusion protrudes toward the second side surface Ps2.

5. The electrolytic capacitor according to claim 1, wherein, The planar shape of the protrusion is triangular.

6. The electrolytic capacitor according to any one of claims 1 to 5, wherein, The protrusion has two main surfaces and a side surface Xs connecting the two main surfaces. The side surface Xs has a first side surface Xs1 on the first end face Pe1 side and a second side surface Xs2 on the second end face Pe2 side.

7. The electrolytic capacitor according to claim 6, wherein, The distance between the first side surface Xs1 and the first end face Pe1 increases as the distance moves away from the lead side surface Ls adjacent to the protrusion.

8. The electrolytic capacitor according to claim 7, wherein, The angle α1 between the lead wire side surface Ls adjacent to the protrusion and the first side surface Xs1 is less than 160°.

9. The electrolytic capacitor according to claim 6, wherein, The angle β1 between the lead side Ls adjacent to the protrusion and the second side Xs2 is less than 90°.

10. The electrolytic capacitor according to claim 9, wherein, The angle β1 is 60° or more.

11. The electrolytic capacitor according to any one of claims 1 to 5, wherein, The coefficient of thermal expansion of the outer casing at 110°C is less than that of the first lead terminal at 110°C.

12. The electrolytic capacitor according to claim 1, wherein, The second lead terminal includes an embedded portion embedded in the outer casing and an exposed portion protruding from the outer casing. The exposed portion of the second lead terminal protrudes from the second end face Pe2. The second lead terminal has two main surfaces and a lead side surface Ls connecting the two main surfaces. The embedded portion of the second lead terminal includes a protrusion that protrudes from the lead side Ls of the second lead terminal.

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