Electrolytic capacitor

Abstract

An electrolytic capacitor includes a capacitor element having a bottom surface and an upper surface, an electrode lead terminal, and an outer packaging resin. The electrode lead terminal includes a terminal portion and two anchor portions. The terminal portion has a main surface exposed at the bottom surface, and has an end edge along a long side direction of the anode lead. The two anchor portions each include a standing portion that stands up from the end edge of the terminal portion toward the upper surface. The standing portion has a first region exposed from the bottom surface in the vicinity of a boundary with the end edge, and the first region has an inclined surface connected to the main surface of the terminal portion, the inclined surface being inclined at an obtuse angle to the main surface of the terminal portion.

Description

Technical Field

[0001] This disclosure relates to electrolytic capacitors. Background Technology

[0002] Electrolytic capacitors are used in various electronic devices. An electrolytic capacitor typically includes a capacitor element with an anode and a cathode, anode leads, cathode leads, and an outer casing covering the capacitor element. The anode leads are electrically connected to the anode, and the cathode leads are electrically connected to the cathode.

[0003] Various shapes of lead terminals have been proposed (e.g., Patent Document 1). Patent Document 1 discloses a tantalum capacitor having an anode lead frame with an expansion portion, the expansion portion serving to strengthen the bonding strength with the cast portion.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-088718 Summary of the Invention

[0007] The lead terminal includes a terminal portion having a main surface that can serve as a mounting surface to a printed circuit board, etc. The main surface of the terminal portion is exposed in the bottom surface of the electrolytic capacitor, and a portion of the terminal portion is embedded in the outer packaging resin. However, due to expansion of the lead terminal during reflow soldering, the terminal portion sometimes separates from the outer packaging resin, requiring improved terminal strength. Furthermore, there is a need to improve the connection strength between the main surface of the terminal portion, achieved by solder, and the printed circuit board, etc. In the anode lead frame described in Patent Document 1, the terminal strength and connection strength are insufficient.

[0008] The first aspect of this disclosure relates to an electrolytic capacitor comprising: a capacitor element having a bottom surface and an upper surface opposite to the bottom surface, and including an anode lead; an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element; and an outer packaging resin disposed around the capacitor element. At least one of the anode lead terminal and the cathode lead terminal is made of a metal sheet and includes a terminal portion partially exposed on the bottom surface and two anchor portions extending from the terminal portion toward the interior of the outer packaging resin. The terminal portion has a main surface exposed on the bottom surface and an end edge along the long side of the anode lead. The two anchor portions each include: an upright portion rising from the end edge of the terminal portion toward the upper surface; and an extension portion extending bently from the upper end of the upright portion. The upright portion has an exposed area near the boundary with the end edge that protrudes from the bottom surface. The exposed area of ​​the upright portion has an inclined surface connected to the main surface of the terminal portion, and the inclined surface is inclined at an obtuse angle to the main surface of the terminal portion.

[0009] According to the first aspect of this disclosure, in an electrolytic capacitor, the terminal strength can be improved, and the connection strength between the terminal portion and the printed circuit board, etc., can be improved.

[0010] Furthermore, the anode lead frame described in Patent Document 1 includes an anode terminal portion comprising two support portions (protrusions). When the tantalum capacitor is mounted to the substrate, the anode terminal portion and the substrate are joined by solder. From the viewpoint of solder fillet formation, the front ends of each of the two support portions protrude slightly from one end of the bottom surface of the tantalum capacitor.

[0011] However, resin burrs can easily remain between the front ends of the two support portions during the casting process. These resin burrs can easily detach during the mounting of the tantalum capacitor to the substrate, resulting in poor mounting (such as poor solder height).

[0012] The second aspect of this disclosure relates to an electrolytic capacitor comprising: a capacitor element having a bottom surface and an upper surface opposite to the bottom surface, and including an anode lead; an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element; and an outer packaging resin disposed around the capacitor element. The anode lead terminal is made of a metal sheet and includes an anode terminal portion having a first main surface and a second main surface opposite to the first main surface, and an anode connection portion electrically connected to the front end of the anode lead, the first main surface being exposed on the bottom surface. The anode terminal portion has a central first region and two lateral regions, 2A and 2B, on either side of the first region. The anode connection portion extends from the first region toward the upper surface. The 2A and 2B regions each include a protrusion extending from the first region, with its front end protruding from the end of the bottom surface. The protrusions in the 2A and 2B regions each have side surfaces connected to the first and second main surfaces, respectively. The side surface of the protrusion in region 2A and the side surface of the protrusion in region 2B are opposite to each other and are inclined in different directions relative to the first main surface and the second main surface.

[0013] According to the second aspect of this disclosure, improper installation of electrolytic capacitors can be suppressed. Attached Figure Description

[0014] Figure 1 This is a perspective view schematically showing the structure of an example of an electrolytic capacitor according to the first embodiment.

[0015] Figure 2 It is shown schematically. Figure 1 A perspective view of a component of an electrolytic capacitor.

[0016] Figure 3 It is shown schematically. Figure 1 A cross-sectional view of the anode lead terminal of the electrolytic capacitor shown.

[0017] Figure 4 It is shown schematically. Figure 1 A cross-sectional view of the cathode lead terminal of the electrolytic capacitor shown.

[0018] Figure 5 It is shown schematically. Figure 1 The electrolytic capacitor shown is a bottom view.

[0019] Figure 6 It is shown schematically. Figure 1 A cross-sectional view of the main parts of the electrolytic capacitor shown.

[0020] Figure 7 It schematically illustrates the process of using solder to... Figure 1 A partial cross-sectional view of the electrolytic capacitor after the anode terminal is connected to the substrate.

[0021] Figure 8 It is shown schematically. Figure 1 The cross-sectional view of the electrolytic capacitor shown.

[0022] Figure 9 This is a cross-sectional view schematically showing the main parts of the structure of another example of the electrolytic capacitor of the first embodiment.

[0023] Figure 10 This is a perspective view schematically showing an example of an electrolytic capacitor according to the second embodiment.

[0024] Figure 11 It is shown schematically. Figure 10 A perspective view of a component of an electrolytic capacitor.

[0025] Figure 12 It is shown schematically. Figure 10 A cross-sectional view of the anode lead terminal of the electrolytic capacitor shown.

[0026] Figure 13 It is shown schematically. Figure 10 A cross-sectional view of the cathode lead terminal of the electrolytic capacitor shown.

[0027] Figure 14 It is shown schematically. Figure 10 The electrolytic capacitor shown.

[0028] Figure 15 It schematically shows the view from direction (D1). Figure 10 A side view of the electrolytic capacitor shown (anode terminal side).

[0029] Figure 16 This schematically shows the view from direction (D2). Figure 10 The electrolytic capacitor shown is a side view of the main part of the electrolytic capacitor (anode terminal side).

[0030] Figure 17 It is shown schematically. Figure 10 The cross-sectional view of the electrolytic capacitor shown.

[0031] Figure 18 This is a side view schematically showing another example of the electrolytic capacitor of the second embodiment. Detailed Implementation

[0032] (First Embodiment)

[0033] Hereinafter, the first embodiment of this disclosure will be described by way of example, but this disclosure is not limited to the examples described below. In the following description, specific values ​​and materials are sometimes shown, but other values ​​and materials may be applied as long as the effects of this disclosure can be obtained. In addition, for the constituent elements other than those characteristic of this disclosure, the constituent elements of a known electrolytic capacitor may also be applied.

[0034] (Electrolytic capacitor)

[0035] The electrolytic capacitor disclosed herein has a bottom surface and an upper surface opposite to the bottom surface. Hereinafter, the bottom surface and the upper surface are sometimes referred to as "bottom surface (B)" and "upper surface (T)". The electrolytic capacitor of this disclosure includes: a capacitor element including an anode lead; anode lead terminals and cathode lead terminals electrically connected to the capacitor element; and an outer packaging resin disposed around the capacitor element.

[0036] At least one of the anode and cathode lead terminals is made of a metal sheet and includes a terminal portion exposed on the bottom surface (B) and two anchoring portions extending from the terminal portion toward the interior of the outer packaging resin. The lead terminal including the two anchoring portions is sometimes referred to as a "lead terminal (L)". The terminal portion has a main surface exposed on the bottom surface (B). Hereinafter, this main surface is sometimes referred to as the "main surface (S1)".

[0037] The terminal portion has two end edges extending along the direction of the anode lead (the direction of the long side of the anode lead). Hereinafter, this direction will sometimes be referred to as "direction (D1)" and sometimes as "direction (D2)" the direction perpendicular to direction (D1). In addition, this end edge will sometimes be referred to as "end edge (E)". The two anchoring parts respectively include an upright portion that rises from the end edge (E) toward the upper surface (T) and an extension portion that extends from the upper end of the upright portion by bending.

[0038] The upright portion of the anchoring part (except for the exposed area (A) described later) and the extension portion are embedded in the outer packaging resin. Furthermore, the metal sheet constituting the lead terminal (L) is bent at two points: the boundary between the terminal portion and the upright portion, and the boundary between the upright portion and the extension portion. According to this structure, the directions of extension of the upright portion and the extension portion are different. Therefore, the anchoring part exhibits a high anchoring effect. Therefore, according to this disclosure, separation of the lead terminal (L) from the outer packaging resin can be suppressed. That is, according to this disclosure, an electrolytic capacitor with high terminal strength and high reliability can be obtained.

[0039] Each of the two anchoring portions has an area exposed from the bottom surface (B) near the boundary with the end edge (E). Hereinafter, this area will sometimes be referred to as the "exposed area (A)". The exposed area (A) is formed by a portion of the terminal portion protruding from the bottom surface (B) in the thickness direction (the terminal portion is positioned on the main surface (S1) and protrudes slightly from the outer surface of the outer packaging resin). The exposed area (A) can also function as a terminal portion and together with the terminal portion can form a solder-based bonding portion with the substrate.

[0040] The exposed area (A) has an inclined surface connected to the main surface (S1). Hereinafter, this inclined surface will sometimes be referred to as "inclined surface (S2)". The inclined surface (S2) is inclined at an obtuse angle to the main surface (S1). By providing the inclined surface (S2), it is easy to form a good solder fillet at the joint between the solder-based terminal and the substrate, thereby improving the connection strength between the terminal and the substrate. The two anchoring portions can, together with the increased terminal strength resulting from the anchoring effect, also contribute to improving the connection strength of the terminal.

[0041] Two inclined surfaces (S2) are formed along the end edge (E) respectively, and the two inclined surfaces (S2) are provided on both sides of the terminal portion in the direction (D2). This effectively improves the connection strength relative to the direction (D2). These two inclined surfaces (S2) can be formed by erecting the upright portions from the end edges (E) of the two anchor portions. The upright portions can be erected approximately at a right angle (e.g., more than 80° and less than 100°) relative to the terminal portion, or they can be erected at an obtuse angle (e.g., more than 100° and less than 150°) relative to the terminal portion.

[0042] The tilt angle θ of the inclined surface (S2) relative to the main surface (S1) is, for example, 135° to 175°, or 145° to 165°. Here, the tilt angle θ refers to the angle formed by the main surface (S1) and the inclined surface (S2) in a cross section perpendicular to the direction (D1) of the electrolytic capacitor (including the terminal portion of the lead terminal (L) and the cross section of the upright portion), or when the electrolytic capacitor is viewed from the direction (D1). In this cross section (or when the electrolytic capacitor is viewed from the direction (D1), the outline of the inclined surface (S2) can be a straight line or a curve such as an arc with a slightly bulging portion. In the case of the curved shape, the tilt angle θ refers to the angle formed by the line segment (chord) connecting the two ends of the curve (arc) and the main surface. In addition, in this curve, one end is the boundary between the inclined surface (S2) and the main surface (S1) (end edge (E)), and the other end is the part where the upright portion begins to protrude from the bottom surface (B).

[0043] There are no particular restrictions on the size of the anchoring part, as long as the anchoring effect is achieved. Examples of anchoring part dimensions are explained below.

[0044] The two anchoring portions included in a single lead terminal (L) are typically symmetrical in shape with respect to a plane perpendicular to the bottom surface (B) and passing through the central axis of the anode lead, but they may not be symmetrical. When both the anode lead terminal and the cathode lead terminal include anchoring portions, the shapes of the anchoring portions of the anode lead terminal and the cathode lead terminal may be the same or different.

[0045] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the extended portion is in contact with the outer packaging resin. Alternatively, in the electrolytic capacitor of this disclosure, it is preferable that the anchoring portion is not in contact with the capacitor element. Based on these structures, a high anchoring effect can be obtained.

[0046] The two anchoring portions can also be bent in different directions (opposite rotation directions) at the boundaries between the terminal portion and the upright portion, and at the boundaries between the upright portion and the extension portion. Here, bending in different directions means that the metal sheet constituting the lead terminal (L) is bent at the boundary between the terminal portion and the upright portion such that one side of the metal sheet (the side facing the upper surface (T)) forms a valley, and at the boundary between the upright portion and the extension portion such that the same side forms a mountain. More specifically, the extension portions of the two anchoring portions can also be bent from the upper end of the upright portion and extend in mutually distancing directions. That is, the extension portions of the two anchoring portions can also be bent from the upper end of the upright portion and extend in mutually distancing directions in a direction perpendicular to the direction of the anode lead extension. The formation of the anchoring portions with this structure is simple. Furthermore, when using anchoring portions with this structure, it is easy to fill with a material such as molding resin. Alternatively, the two anchoring portions can also be bent in the same direction (the same rotation direction) at the boundaries between the terminal portion and the upright portion, and at the boundaries between the upright portion and the extension portion.

[0047] In the electrolytic capacitor disclosed herein, both the anode lead terminal and the cathode lead terminal may each include two anchoring portions. According to this structure, an electrolytic capacitor with particularly high terminal strength and reliability can be obtained. Alternatively, only the anode lead terminal may include two anchoring portions, or only the cathode lead terminal may include two anchoring portions.

[0048] The following describes one example of the constituent elements of the electrolytic capacitor of this disclosure.

[0049] (Anode lead terminal)

[0050] The anode lead terminal can also be formed by processing a metal sheet using known metalworking methods. The material of the anode lead terminal can be any material suitable for use as the anode lead terminal of an electrolytic capacitor. For example, known materials for anode leads of electrolytic capacitors can be used. The anode lead terminal can also be formed by processing a metal sheet (including metal plates and metal foils) made of metal (copper, copper alloys, etc.). The surface of the metal sheet can be plated with nickel, gold, or other plating. The thickness of the metal sheet constituting the anode lead terminal can also be in the range of 25 μm to 200 μm (e.g., 25 μm to 100 μm).

[0051] The anode lead terminal may also include an anode terminal portion exposed on the bottom surface (B) and a wire connection portion extending from the anode terminal portion toward the upper surface (T). As described above, two anchoring portions may also extend from the anode terminal portion. The anode lead of the capacitor element is connected to the wire connection portion. The wire connection portion may also have a wire receiving portion at its front end that is bent in a manner substantially parallel to the bottom surface (B). The wire receiving portion may be bent toward the front surface of the capacitor element or in the opposite direction. Here, the front surface of the capacitor element refers to the surface facing the end face of the capacitor element with the wire protruding. The wire receiving portion allows for a highly reliable and easy connection between the wire connection portion and the anode lead.

[0052] (Cathode lead terminal)

[0053] The cathode lead terminal can also be formed by processing a metal sheet using a known metal processing method. The material of the cathode lead terminal can be any material suitable for use as the cathode lead terminal material in an electrolytic capacitor. For example, a known material for cathode leads in electrolytic capacitors can also be used. The cathode lead terminal can also be formed using a metal sheet exemplified as the material for the anode lead terminal.

[0054] The cathode lead terminal may also include a cathode terminal portion exposed on the bottom surface (B) and a connection portion electrically connected to the cathode portion of the capacitor element. The cathode portion of the capacitor element is electrically connected to the cathode terminal portion via this connection portion. As described above, two anchor portions may also extend from the cathode terminal portion.

[0055] (Capacitor element)

[0056] There are no particular limitations on the capacitor elements. Known capacitor elements for solid electrolytic capacitors or those with the same structure can also be used. Furthermore, the electrolytic capacitor of this disclosure may also comprise multiple capacitor elements. In this case, the anode portions of the multiple capacitors are electrically connected to the anode lead terminals.

[0057] An example capacitor element includes an anode portion and a cathode portion. The anode portion includes an anode body with a dielectric layer formed on its surface and anode leads, and the cathode portion includes an electrolyte layer and a cathode layer. The electrolyte layer is disposed between the dielectric layer and the cathode layer formed on the surface of the anode body. These components are not particularly limited, and known components for solid electrolytic capacitors can also be used. Examples of these components are described below.

[0058] (Anode)

[0059] Alternatively, a porous sintered body in the shape of a column (e.g., cuboid) obtained by sintering the particles that will become the material can be used for the anode body. Examples of the particles mentioned above include particles of a valve-acting metal, particles of an alloy containing a valve-acting metal, and particles of a compound containing a valve-acting metal. Only one type of these particles can be used, or two or more can be mixed. Titanium (Ti), tantalum (Ta), niobium (Nb), etc., can be used as the valve-acting metal. Alternatively, the anode body can also be formed by roughening the surface of a substrate (such as a foil or plate-shaped substrate) containing the valve-acting metal through etching or the like.

[0060] The anode portion can also be manufactured using the following method. First, a portion of the anode lead is embedded in metal powder, which serves as the anode body material, and the metal powder is pressed into a cylindrical shape (e.g., a cuboid). Then, the anode body is formed by sintering the metal powder. In this way, an anode portion comprising the anode body and a portion of the anode lead embedded within the anode body can be manufactured.

[0061] There are no particular limitations on the dielectric layer formed on the surface of the anode body, and it can be formed by known methods. For example, the dielectric layer can be formed by anodic oxidation of the surface of the anode body by immersing it in a forming solution. Alternatively, the dielectric layer can be formed by oxidizing the surface of the anode body by heating it in an oxygen-containing atmospheric atmosphere.

[0062] (Anode lead)

[0063] The anode lead can also be a wire made of metal (anode conductor). Examples of materials for the anode lead include the valve-acting metals mentioned above, copper, aluminum, aluminum alloys, etc. Part of the anode lead is embedded in the anode body, while the remainder protrudes from the anode body. Additionally, the anode lead is typically rod-shaped, but it can also be plate-shaped.

[0064] (Electrolyte layer)

[0065] There are no particular limitations on the electrolyte layer; any electrolyte layer known for solid electrolytic capacitors can be used. Furthermore, in this specification, the electrolyte layer may be read as a solid electrolyte layer, and the electrolytic capacitor may be read as a solid electrolytic capacitor. The electrolyte layer can also be a stack of two or more different electrolyte layers.

[0066] The electrolyte layer is configured to cover at least a portion of the dielectric layer. The electrolyte layer can also be formed using manganese compounds or conductive polymers. Examples of conductive polymers include polypyrrole, polythiophene, polyaniline, and their derivatives. They can be used individually or in combination. Furthermore, the conductive polymer can also be a copolymer of two or more monomers. Additionally, derivatives of conductive polymers refer to polymers with a conductive polymer as their basic backbone. For example, examples of polythiophene derivatives include poly(3,4-ethylenedioxythiophene).

[0067] Dopants can also be added to conductive polymers. The dopants can be selected based on the conductive polymer, and well-known dopants can also be used. Examples of dopants include naphthalenesulfonic acid, p-toluenesulfonic acid, polystyrenesulfonic acid, and their salts. An example electrolyte layer can be formed using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrenesulfonic acid (PSS).

[0068] An electrolyte layer containing a conductive polymer can also be formed by polymerizing raw material monomers on a dielectric layer. Alternatively, it can be formed by coating a liquid containing a conductive polymer (and, if necessary, dopants) onto a dielectric layer and then allowing it to dry.

[0069] (Cathode layer)

[0070] The cathode layer can also be a conductive layer formed on the electrolyte layer, for example, it can be a conductive layer formed to cover the electrolyte layer. The cathode layer can also include a carbon layer formed on the electrolyte layer and a metal paste layer formed on the carbon layer. The carbon layer can also be formed from a conductive carbon material such as graphite and a resin. The metal paste layer can also be formed from metal particles (e.g., silver particles) and a resin, for example, it can also be formed from silver paste.

[0071] The cathode layer is electrically connected to the cathode lead terminals. The cathode layer can also be electrically connected to the cathode lead terminals via a conductive component. The conductive component can be formed from metal particles (e.g., silver particles) and resin, for example, from silver paste.

[0072] (Outer packaging resin)

[0073] The outer packaging resin is disposed around the capacitor element so that the capacitor element is not exposed on the surface of the electrolytic capacitor. Furthermore, the outer packaging resin insulates the anode and cathode leads. Known outer packaging resins for electrolytic capacitors can also be used. For example, the outer packaging resin can also be formed using an insulating resin material used to seal the capacitor element. Examples of materials for the outer packaging resin include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester. The outer packaging resin may also contain substances other than resin (inorganic fillers, etc.).

[0074] Hereinafter, an example of an electrolytic capacitor according to the first embodiment of the present disclosure will be specifically described with reference to the accompanying drawings. The constituent elements described above can be applied to the constituent elements of the electrolytic capacitor of the example described below. Furthermore, the constituent elements of the electrolytic capacitor of the example described below can be modified based on the above description. Additionally, the matters described below can also be applied to the embodiments described above. Furthermore, in the embodiments described below, constituent elements that are not essential to the electrolytic capacitor of the present disclosure may be omitted.

[0075] exist Figure 1 A perspective view of the electrolytic capacitor 100 according to the first embodiment is schematically shown. Figure 2 schematically shown Figure 1 A perspective view of the anode lead terminal 120 and cathode lead terminal 130 of the electrolytic capacitor 100 shown. Figure 3 The image shows a cross-sectional view of the anchoring portion of the anode lead terminal 120. Figure 4 A cross-sectional view of the anchoring portion of the cathode lead terminal 130 is shown. Additionally, in Figure 3 as well as Figure 4 In order to make it easy to understand, the position of the capacitor element 110 is shown with dashed lines and the outline of the outer packaging resin 101 is shown with solid lines. Figure 3 as well as Figure 4 This is a diagram showing a cross-section of the electrolytic capacitor 100 perpendicular to the direction (D1). Figure 5 schematically shown Figure 1 The electrolytic capacitor 100 shown is a bottom view. Figure 5 In the image, the portion embedded in the outer packaging resin 101 is shown by a dashed line.

[0076] exist Figure 6 The text shows the representation. Figure 1 A cross-sectional view of the main portion near the boundary between the anode terminal portion 121 and the upright portion 123a in the electrolytic capacitor 100 shown. Figure 7 The diagram shows that solder 201 will... Figure 1This is a main cross-sectional view of the state in which the anode terminal 121 of the electrolytic capacitor 100 is connected to the substrate 202. Figure 6 as well as Figure 7 This is a diagram showing a cross-section of the electrolytic capacitor 100 perpendicular to the direction (D1). Further, Figure 8 schematically shown Figure 1 A cross-sectional view of the electrolytic capacitor 100 shown. Figure 8 The sectional view is a cross-sectional view passing through the central axis of the anode lead (anode conductor) 112. Additionally, for ease of understanding, in the following figures, sometimes only the outlines of some constituent elements are shown. For example, in... Figure 1 In the image, the outer packaging resin 101 is shown by an outline represented by dashed lines.

[0077] The electrolytic capacitor 100 has a bottom surface 100b and an upper surface 100t opposite to the bottom surface 100b. The electrolytic capacitor 100 includes a capacitor element 110, an anode lead terminal 120, a cathode lead terminal 130, a conductive member 141, and an outer packaging resin 101. The anode lead terminal 120 and the cathode lead terminal 130 are electrically connected to the capacitor element 110, respectively.

[0078] Reference Figure 2 , Figure 5 , Figure 6 The anode lead terminal 120 includes an anode terminal portion 121, a wire connection portion 122, and two anchoring portions 123. A portion of the thickness of the anode terminal portion 121 (e.g., about half the thickness of the anode terminal portion 121) is exposed on the bottom surface 100b. The anode terminal portion 121 has a main surface 121S exposed on the bottom surface 100b. The wire connection portion 122 extends from the anode terminal portion 121 toward the upper surface 100t. The groove portion of the wire connection portion 122 for receiving the front end of the anode lead 112 is formed by resistance welding of the anode lead 112 and the wire connection portion 122. The anode lead 112 and the wire connection portion 122 can also be connected by fusion welding, soldering, or the like.

[0079] Reference Figure 1 , Figure 2 Two anchoring portions 123 extend from two end edges 121e respectively. The two end edges 121e are the end edges of the anode terminal portion 121, and are a pair of end edges extending in the direction D1 along the anode lead 112.

[0080] Reference Figure 1 , Figure 3The two anchoring portions 123 each include an upright portion 123a that rises from the end edge 121e toward the upper surface 100t, and an extension portion 123b that extends bent from the upper end of the upright portion 123a. In an example shown in the first embodiment, the two anchoring portions 123 are bent in different directions at the boundary between the anode terminal portion 121 and the upright portion 123a, and at the boundary between the upright portion 123a and the extension portion 123b. Specifically, one surface of the metal sheet constituting the anode lead terminal 120 (the surface on the upper surface 100t side) is bent in a valley shape at the boundary between the anode terminal portion 121 and the upright portion 123a, and in a mountain shape at the boundary between the upright portion 123a and the extension portion 123b. As a result, the extension portion 123b extends from the upper end of the upright portion 123a toward the outside of the electrolytic capacitor 100. That is, the extensions 123b of the two anchoring portions 123 are bent from the upper end of the upright portion 123a and extend in opposite directions in a direction (D2) perpendicular to the direction (D1) of the anode lead 112. Alternatively, the direction in which the extensions 123b extend may be approximately parallel to the bottom surface 100b, for example, the angle between them may be in the range of -20° to 20°.

[0081] Reference Figure 3 , Figure 5 , Figure 6 Each of the two anchoring portions 123 has an upright portion 123a at its boundary with the end edge 121e, with a region 124 exposed on the bottom surface 100b. The region 124 has an inclined surface 124S connected to the main surface 121S, the inclined surface 124S being inclined at an obtuse angle to the main surface 121S. (Refer to...) Figure 7 When the anode terminal portion 121 of the electrolytic capacitor 100 and the substrate 202 are joined by solder 201, the presence of the region 124 with the inclined surface 124S makes it easy to form a rounded corner at the joint based on the solder 201, thereby improving the bonding strength.

[0082] Reference Figure 6 The tilt angle θ of inclined surface 124S relative to principal surface 121S Figure 6 The θ in the equation can be, for example, 135° to 175°, or 145° to 165°. Figure 6 A cross-section of the electrolytic capacitor 100 perpendicular to the direction (D1) is shown (including the cross-section of the anode terminal portion 121 and the upright portion 123a). Figure 6 The profile of the inclined surface 124S is curved. Figure 6 The angle θ (tilt angle θ) is the angle formed by the line segment L2 connecting the two ends of the curve of the contour of the inclined surface 124S and the main surface 121S. In addition, in this curve, one end is the boundary between the inclined surface 124S and the main surface 121S (end edge 121e), and the other end is the part of the upright part 123a that begins to protrude from the bottom surface 100b.

[0083] The cathode lead terminal 130 includes a cathode terminal portion 131, a connecting portion 132, and two anchoring portions 133. A portion of the thickness of the cathode terminal portion 131 (e.g., about half the thickness of the cathode terminal portion 131) is exposed on the bottom surface 100b. The cathode terminal portion 131 has a main surface 131S exposed on the bottom surface 100b. The connecting portion 132 is provided with the cathode terminal portion 131 and a step. The connecting portion 132 is electrically connected to the cathode portion 115 (cathode layer 117) described later via a conductive member 141. That is, the cathode terminal portion 131 is electrically connected to the capacitor element 110 via the connecting portion 132 and the conductive member 141. The conductive member 141 is not particularly limited, and known conductive members can also be used. For example, the conductive member 141 can also be formed from metal paste or the like.

[0084] Two anchoring portions 133 extend from two end edges 131e respectively. The two end edges 131e are the end edges of the cathode terminal portion 131, and are a pair of end edges extending in the direction D1 along the anode lead 112.

[0085] Reference Figure 1 , Figure 4 Each of the two anchoring portions 133 includes an upright portion 133a rising from the end edge 131e toward the upper surface 100t, and an extension portion 133b extending from the upper end of the upright portion 133a by bending. In an example shown in the first embodiment, the boundaries between the cathode terminal portion 131 and the upright portion 133a, and between the upright portion 133a and the extension portion 133b, are bent in different directions. That is, the extension portions 133b of the two anchoring portions 133 are bent from the upper end of the upright portion 133a and extend in mutually distancing directions in a direction (D2) perpendicular to the direction (D1) of the anode lead 112. Alternatively, the direction in which the extension portion 133b extends may be substantially parallel to the bottom surface 100b, for example, the angle between them being in the range of -20° to 20°.

[0086] Reference Figure 4 , Figure 5 Each of the two anchoring portions 133 has an upright portion 133a at its boundary with the end edge 131e, which is exposed on the bottom surface 100b. The portion 134 has an inclined surface 134S connected to the main surface 131S, and the inclined surface 134S is inclined at an obtuse angle to the main surface 131S. By providing the portion 134 with the inclined surface 134S, the same effect as when providing the portion 124 with the inclined surface 124S can be achieved.

[0087] In a cross-section perpendicular to the direction (D1) of the electrolytic capacitor 100 (including the cross-section of the cathode terminal portion 131 and the upright portion 133a), the profile of the inclined surface 134S is curved, and the inclination angle θ of the inclined surface 134S relative to the main surface 131S is shown in the same way as that of the inclined surface 124S. The inclination angle θ of the inclined surface 134S is, for example, 135° to 175°, or it can be 145° to 165°.

[0088] Reference Figure 3 The distance L1 from the surface of the anode terminal portion 121 to the lower surface of the extension portion 123b can also be 50 μm or more (e.g., 75 μm or more, 100 μm or more). By setting the distance L1 to 50 μm or more (e.g., 75 μm or more, 100 μm or more), it becomes easier to fill the lower part of the extension portion 123b with the outer packaging resin 101. Furthermore, in Figure 3 In the process, the upper surface of the extension portion 123b is located below the lower surface of the capacitor element 110, but as long as the extension portion 123b does not interfere with the capacitor element 110, it can also be located at a higher position than the extension portion 123b.

[0089] Reference Figure 4 The distance L3 from the surface of the cathode terminal portion 131 to the lower surface of the extension portion 133b can be 50 μm or more (e.g., 75 μm or more, 100 μm or more), or it can be in the range of 50 μm to 500 μm (e.g., 75 μm to 200 μm). The distance L4 from the upper surface of the extension portion 133b to the lower surface of the capacitor element 110 can also be 50 μm or more (e.g., 75 μm or more, 100 μm or more), or it can be in the range of 50 μm to 500 μm (e.g., 75 μm to 200 μm). By setting the distances L1 and L3 to 50 μm or more (e.g., 75 μm or more, 100 μm or more), it becomes easier to fill the lower and upper parts of the extension portion 133b with the outer packaging resin 101.

[0090] The horizontal distance W1 (distance along direction D2) from end edge 121e to the front end of extension 123b and the horizontal distance W2 (distance along direction D2) from end edge 131e to the front end of extension 133b can each be 50 μm or more (e.g., 75 μm or more, 100 μm or more). By setting the horizontal distance W1 to this range, a high anchoring effect can be obtained. Furthermore, from the viewpoints of shape stability and processability, the horizontal distances W1 and W2 can also be set to 200 μm or more respectively.

[0091] Furthermore, the shapes of the anode lead terminal 120 and cathode lead terminal 130 described above are merely examples and are not limited to the shapes described herein. For example, either the anode lead terminal 120 or the cathode lead terminal 130 may not include an anchoring portion. Moreover, as long as it is electrically connected to the cathode portion 115 (cathode layer 117), the connection portion of the cathode lead terminal 130 may not be in the position shown in the figure, nor may it have the shape shown in the figure.

[0092] Although the upright portion 123a stands approximately perpendicular (e.g., more than 80° but less than 100°) to the anode terminal portion 121, as Figure 9 As shown, the upright portion 153a can also be inclined at an obtuse angle to the anode terminal portion 121. The upright portion 153a can also be erected at an obtuse angle relative to the anode terminal portion 121, for example, 100° to 150°. The inclination degree of the inclined surface 154S in the region 154 of the upright portion 153a exposed on the bottom surface 100b within the boundary with the end edge 121e can be adjusted by changing the inclination degree of the upright portion 153a relative to the anode terminal portion 121. That is, the inclination angle θ of the inclined surface 154S relative to the main surface 121S can also be adjusted. Figure 9 In this process, the angle θ formed by the line segment L2 connecting the two ends of the curve of the inclined surface 154S and the main surface 121S is adjusted. Similarly, the upright part of the cathode lead terminal can also be inclined at an obtuse angle to the cathode terminal part.

[0093] Reference Figure 8 The capacitor element 110 includes an anode portion 111 and a cathode portion 115. The anode portion 111 includes an anode body 113 on which a dielectric layer 114 is formed, and an anode lead 112. The cathode portion 115 includes an electrolyte layer 116 configured to cover the dielectric layer 114, and a cathode layer 117. The cathode layer 117 includes, for example, a carbon layer formed on the electrolyte layer 116 and a metal particle layer formed on the carbon layer. The metal particle layer is a layer formed using, for example, metal paste.

[0094] As described above, the anode portion 111 of the capacitor element 110 is electrically connected to the anode lead terminal 120, and the cathode portion 115 of the capacitor element 110 is electrically connected to the cathode lead terminal 130. When the electrolytic capacitor 100 is mounted on a substrate of an electronic device, the anode terminal portion 121 and the cathode terminal portion 131 can also be mounted by soldering.

[0095] The following describes an example of a method for manufacturing an electrolytic capacitor 100. First, a capacitor element 110, an anode lead terminal 120, and a cathode lead terminal 130 are prepared. There are no particular limitations on the manufacturing method of the capacitor element 110; it can be manufactured using known methods. The anode lead terminal 120 and the cathode lead terminal 130 can be formed using known metalworking methods.

[0096] Next, the anode lead 112 and the anode lead terminal 120 are connected, and the cathode layer 117 and the cathode lead terminal 130 are connected. The anode lead 112 and the anode lead terminal 120 can be connected by welding (e.g., laser welding). The connection between the cathode layer 117 and the cathode lead terminal 130 can be performed, for example, by the following method: First, a metal paste that serves as a conductive member 141 is applied to the surface of the connection portion 132 of the cathode lead terminal 130 and / or the surface of the cathode layer 117. Next, the cathode layer 117 and the connection portion 132 are bonded together via the metal paste, and the conductive member 141 is formed by curing the metal paste. In this way, the cathode layer 117 and the cathode lead terminal 130 can be connected.

[0097] Next, the capacitor element is sealed using a material of the outer packaging resin 101 (e.g., molding resin). The sealing process can be performed using known methods. Thus, the electrolytic capacitor 100 can be manufactured. Furthermore, other electrolytic capacitors of this disclosure can also be manufactured using the same method.

[0098] (Second Implementation)

[0099] The second embodiment of this disclosure will be described below by way of example, but this disclosure is not limited to the examples described below. In the following description, specific values ​​and materials are sometimes illustrated, but other values ​​and materials may be applied as long as the effects of this disclosure can be obtained. In addition, known components of electrolytic capacitors may be applied to components other than those characteristic of this disclosure.

[0100] (Electrolytic capacitor)

[0101] The electrolytic capacitor disclosed herein has a bottom surface and an upper surface opposite to the bottom surface. Hereinafter, the bottom surface and the upper surface will sometimes be referred to as "bottom surface (B)" and "upper surface (T)". The electrolytic capacitor of this disclosure includes: a capacitor element including an anode lead; an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element; and an outer packaging resin disposed around the capacitor element. Hereinafter, the direction in which the anode lead extends (the direction of the long side of the anode lead) will sometimes be referred to as "direction (D1)". The direction perpendicular to the direction in which the anode lead extends will sometimes be referred to as "direction (D2)".

[0102] The anode lead terminal is made of a metal sheet. The anode lead terminal includes an anode terminal portion having a first main surface and a second main surface opposite to the first main surface (back side), and an anode connection portion electrically connected to the front end of the anode lead. The first main surface is exposed on the bottom surface (B). From the viewpoint of solder fillet formation, a portion of the anode terminal portion in the thickness direction may also be exposed on the bottom surface (B).

[0103] The anode terminal portion has a central first region and two lateral regions, 2A and 2B. The anode connection portion is configured to stand upright from the first region toward the upper surface (T). Regions 2A and 2B each include a protrusion extending from the first region, with its front end protruding from the end of the bottom surface (B). The protrusions in regions 2A and 2B generally extend from the first region in the direction (D1). From the viewpoint of solder fillet formation, the anode terminal portion is configured such that, when the electrolytic capacitor is viewed from the bottom surface (B) side, the front end of the protrusion slightly protrudes from the end of the bottom surface (B). The second main surface is exposed at the front end of the protrusion and is in contact with the outer packaging resin in the area other than the front end of the protrusion.

[0104] The protrusions in region 2A and region 2B each have a side surface connected to the first main surface and the second main surface, respectively. Hereinafter, this side surface will be referred to as "side surface (S)". The side surface (S) of the protrusions in region 2A and region 2B face each other and are inclined in different directions relative to the first and second main surfaces. That is, the two side surfaces (S) are inclined in different directions from the first main surface to the second main surface. When the two side surfaces (S) are inclined as described above, when stress is applied to the anode lead terminals in processes after the outer packaging resin is formed (such as the process of separating each capacitor element, the process of cutting the anode lead terminals, etc.), the resin burrs remaining between the front ends (side surfaces (S)) of the two protrusions are easily removed. Therefore, the residue of resin burrs and the associated poor installation of the electrolytic capacitor are suppressed.

[0105] The side surfaces (S) of the protrusions in region 2A and region 2B are preferably inclined at an obtuse angle to the first main surface. In this case, the side surfaces (S) are inclined at an acute angle to the second main surface. In this case, it is easier to form good solder fillet, which can improve the connection strength between the anode terminal and the substrate. In this case, the inclination angle of the side surfaces (S) relative to the first main surface can also be 100° or more and 135° or less, or 110° or more and 135° or less. When the inclination angle is within the above range, it is easier to obtain the effect of suppressing poor installation and the effect of improving connection strength.

[0106] When viewing the electrolytic capacitor (anode terminal side) from direction (D1), the tilt angle of the side surface (S) relative to the first main surface is the angle formed by the first main surface and the side surface (S). When viewing the electrolytic capacitor (anode terminal side) from direction (D1), the outline of the side surface (S) can be either a straight line or a curve such as an arc with a slight bulge. When the outline of the side surface (S) is curved, the tilt angle refers to the angle formed by the line segment (chord) connecting the two ends of the curve (arc) and the first main surface.

[0107] The sides (S) of the protrusions in regions 2A and 2B can also be inclined at an acute angle to the first main surface. In this case, the sides (S) are inclined at an obtuse angle to the second main surface. In this case, it is easy to ensure a large contact area between the anode terminal and the substrate. From the viewpoint of ensuring the contact area between the anode terminal and the substrate and suppressing poor mounting, the inclination angle of the sides (S) relative to the first main surface can be 45° or more and 80° or less, or 45° or more and 70° or less.

[0108] Regions 2A and 2B (excluding the protrusions) are typically symmetrical in shape with respect to a central axis perpendicular to the bottom surface (B) and passing through the anode lead, but may not be symmetrical. The protrusions in regions 2A and 2B are typically symmetrical in shape with respect to a central axis perpendicular to the bottom surface (B) and passing through the anode lead.

[0109] At least one of the anode lead terminal and the cathode lead terminal may also include a terminal portion having a main surface exposed on the bottom surface (B), and two anchoring portions extending from the terminal portion (in the case of the anode terminal portion, regions 2A and 2B) and embedded in the outer packaging resin. Hereinafter, the lead terminal including the two anchoring portions is sometimes referred to as the "lead terminal (L)". The terminal portion (in the case of the anode terminal portion, regions 2A and 2B) may also have two end edges extending in the direction D1 along the anode lead. The two anchoring portions may also each include an upright portion rising from the end edge of the terminal portion (in the case of the anode terminal portion, regions 2A and 2B) toward the upper surface (T), and an extension portion extending from the upper end of the upright portion by bending.

[0110] As described above, the anchoring portion (the upright portion and the extension portion) is embedded in the outer packaging resin. Furthermore, the metal sheet constituting the lead terminal (L) is bent at two points: the boundary between the terminal portion and the upright portion, and the boundary between the upright portion and the extension portion. Due to this structure, the directions of extension of the upright portion and the extension portion are different. Therefore, the anchoring portion provides a high anchoring effect. This prevents the lead terminal (L) (terminal portion) from separating from the outer packaging resin, thereby improving the terminal strength.

[0111] There are no specific limitations on the dimensions of the anchoring part, as long as they are sufficient to achieve the anchoring effect. The following examples illustrate the dimensions of the anchoring part.

[0112] The two anchoring portions included in a single lead terminal (L) are typically symmetrical in shape with respect to a plane perpendicular to the bottom surface (B) and passing through the central axis of the anode lead, but they may not be symmetrical. When both the anode lead terminal and the cathode lead terminal include anchoring portions, the shapes of the anchoring portions of the anode lead terminal and the cathode lead terminal may be the same or different.

[0113] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the extended portion is in contact with the outer packaging resin. In another viewpoint, in the electrolytic capacitor of this disclosure, it is preferable that the anchoring portion is in contact with the capacitor element. Based on these structures, a high anchoring effect can be obtained.

[0114] The two anchoring portions can also be bent in different directions (opposite rotational directions) at the boundaries between the terminal portion and the upright portion, and at the boundaries between the upright portion and the extension portion, respectively. Here, bending in different directions means that the metal sheet constituting the lead terminal (L) is bent at the boundary between the terminal portion and the upright portion such that one side of the metal sheet (the side facing the upper surface (T)) forms a valley, and at the boundary between the upright portion and the extension portion such that the same side forms a mountain. More specifically, the extension portions of the two anchoring portions can also be bent from the upper end of the upright portion, extending in mutually distancing directions. That is, the extension portions of the two anchoring portions can also be bent from the upper end of the upright portion, extending in mutually distancing directions in a direction (D2) perpendicular to the direction (D1) of the anode lead extension. The formation of the anchoring portions with this structure is simple. Furthermore, when using the anchoring portion with this structure, it is easy to fill it with a material such as molding resin. In addition, the two anchoring parts can be bent in the same direction (the same direction of rotation) at the boundary between the terminal part and the upright part and at the boundary between the upright part and the extension part, respectively.

[0115] In the electrolytic capacitor disclosed herein, both the anode lead terminal and the cathode lead terminal may each include two anchoring portions. According to this structure, an electrolytic capacitor with particularly high terminal strength and reliability can be obtained. Alternatively, only the anode lead terminal may include two anchoring portions, or only the cathode lead terminal may include two anchoring portions.

[0116] The following describes one example of the constituent elements of the electrolytic capacitor of this disclosure.

[0117] (Anode lead terminal)

[0118] The anode lead terminal can also be formed by processing a metal sheet using a known metalworking method. The material of the anode lead terminal can be any material suitable for use as the anode lead terminal of an electrolytic capacitor. For example, a known material for anode leads of electrolytic capacitors can be used. The anode lead terminal can also be formed by processing a metal sheet (including metal plates and metal foils) made of metal (copper, copper alloys, etc.). Nickel plating, gold plating, or other plating can be applied to the surface of the metal sheet. The thickness of the metal sheet constituting the anode lead terminal can also be in the range of 25 μm to 200 μm (e.g., 25 μm to 100 μm).

[0119] The anode lead terminal may also include an anode terminal portion exposed on the bottom surface (B) and a wire connection portion (anode connection portion) extending from the anode terminal portion toward the upper surface (T). As described above, two anchor portions may also extend from the anode terminal portion (regions 2A and 2B). The anode lead of the capacitor element is connected to the wire connection portion. The wire connection portion may also have a wire receiving portion at its front end that is bent in a manner substantially parallel to the bottom surface (B). The wire receiving portion may be bent toward the front surface of the capacitor element or in the opposite direction. Here, the front surface of the capacitor element refers to the surface opposite to the end face of the capacitor element with the wire protruding. The wire receiving portion enables a highly reliable and easy connection between the wire connection portion and the anode lead.

[0120] (Cathode lead terminal)

[0121] The cathode lead terminal can also be formed by processing a metal sheet using a known metalworking method. The material of the cathode lead terminal can be any material suitable for use as the cathode lead terminal of an electrolytic capacitor. For example, a known material for cathode leads of electrolytic capacitors can be used. The cathode lead terminal can also be formed from a metal sheet exemplified as a material for anode leads.

[0122] The cathode lead terminal may also include a cathode terminal portion exposed on the bottom surface (B) and a connection portion electrically connected to the cathode portion of the capacitor element. The cathode portion of the capacitor element is electrically connected to the cathode terminal portion via this connection portion. As described above, two anchoring portions may also extend from the cathode terminal portion.

[0123] (Capacitor element)

[0124] There are no particular limitations on the capacitor elements. Known capacitor elements for solid electrolytic capacitors or those with the same structure can also be used. Furthermore, the electrolytic capacitor of this disclosure may also comprise multiple capacitor elements. In this case, the anode portions of the multiple capacitors are electrically connected to the anode lead terminals.

[0125] An example capacitor element includes an anode portion and a cathode portion. The anode portion includes an anode body with a dielectric layer formed on its surface and anode leads, and the cathode portion includes an electrolyte layer and a cathode layer. The electrolyte layer is disposed between the dielectric layer and the cathode layer formed on the surface of the anode body. These components are not particularly limited, and known components for solid electrolytic capacitors can also be used. Examples of these components are the same as those described in the first embodiment, and therefore descriptions are omitted.

[0126] (Outer packaging resin)

[0127] An outer packaging resin is disposed around the capacitor element so that the capacitor element is not exposed on the surface of the electrolytic capacitor. Furthermore, the outer packaging resin insulates the anode and cathode leads. Known outer packaging resins for electrolytic capacitors can also be used for the outer packaging resin. For example, the outer packaging resin can also be formed using an insulating resin material used for sealing the capacitor element. Examples of materials for the outer packaging resin include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester. The outer packaging resin can also be a substance other than resin (inorganic fillers, etc.).

[0128] Hereinafter, an example of an electrolytic capacitor according to the second embodiment of the present disclosure will be specifically described with reference to the accompanying drawings. The constituent elements of the electrolytic capacitor in the example described below can be applied using the aforementioned constituent elements. Furthermore, the constituent elements of the electrolytic capacitor in the example described below can be modified based on the above description. Additionally, the matters described below can also be applied to the embodiments described above. Furthermore, in the embodiments described below, constituent elements that are not essential to the electrolytic capacitor of the present disclosure may be omitted. In the following drawings, structures identical to those in the example of the electrolytic capacitor of the first embodiment are labeled with the same reference numerals.

[0129] exist Figure 10 A perspective view of the electrolytic capacitor 100 according to the second embodiment is schematically shown. Figure 11 schematically shown Figure 10 A perspective view of the anode lead terminal 120 and cathode lead terminal 130 of the electrolytic capacitor 100 shown. Figure 12 The image shows a cross-sectional view of the anchoring portion of the anode lead terminal 120. Figure 13 A cross-sectional view of the anchoring portion of the cathode lead terminal 130 is shown. Additionally, in Figure 12 as well as Figure 13 In the diagram, the position of capacitor element 110 is indicated by a dashed line. Figure 14 schematically shown Figure 10The electrolytic capacitor 100 shown is a bottom view. Figure 14 In the diagram, the portion embedded in the outer packaging resin 101 is shown by dashed lines. The view from direction (D1) will be schematically shown. Figure 10 A side view of the electrolytic capacitor (anode terminal side) is shown. Figure 15 The diagram will schematically show the view from direction (D2). Figure 10 The main part of the electrolytic capacitor (anode terminal side) is shown in the side view. Figure 16 Furthermore, in Figure 17 schematically shown Figure 10 A cross-sectional view of the electrolytic capacitor 100 shown. Figure 17 The sectional view is a cross-sectional view passing through the central axis of the anode lead (anode conductor) 112. Additionally, for ease of understanding, in the following figures, sometimes only the outline of a portion of the constituent elements is shown. For example, in... Figure 10 In the image, the outer packaging resin 101 is shown only by its outline represented by dashed lines.

[0130] The electrolytic capacitor 100 has a bottom surface 100b and an upper surface 100t opposite to the bottom surface 100b. The electrolytic capacitor 100 includes a capacitor element 110, an anode lead terminal 120, a cathode lead terminal 130, a conductive member 141, and an outer packaging resin 101. The anode lead terminal 120 and the cathode lead terminal 130 are electrically connected to the capacitor element 110.

[0131] Reference Figure 11 , Figure 14 , Figure 15 The anode lead terminal 120 is made of a metal sheet and includes an anode terminal portion 121, a wire connection portion 122, and two anchoring portions 123. The anode terminal portion 121 has a first main surface S1 and a second main surface S2 opposite to the first main surface S1, with the first main surface S1 exposed on the bottom surface 100b. A portion of the anode terminal portion 121 in the thickness direction is exposed on the bottom surface 100b. The wire connection portion 122 extends from the anode terminal portion 121 toward the upper surface 100t. A groove for receiving the tip of the anode lead 112 is formed by resistance welding the anode lead 112 and the wire connection portion 122. The anode lead 112 and the wire connection portion 122 can also be connected by fusion welding, soldering, or the like.

[0132] Reference Figure 14The anode terminal portion 121 has a central first region 121a and two second regions 121b (regions 2A and 2B) on either side of the first region 121a. In the direction (D1) in which the anode lead 112 extends, the two second regions 121b extend from the first region 121a and each includes a protrusion 125 whose front end protrudes from the end of the bottom surface 100b. (See reference...) Figure 15 The two protrusions 125 of the second region 121b each have a side surface S3 connected to the first main surface S1 and the second main surface S2. The side surfaces S3 of the two protrusions 125 of the second region 121b are opposite to each other and are inclined in different directions relative to the first main surface S1 and the second main surface S2. That is, the side surfaces S3 of the two protrusions 125 are inclined in different directions from the first main surface S1 to the second main surface S2.

[0133] Reference Figure 15 The side surfaces S3 of the two protrusions 125 in the second region 121b are inclined at an obtuse angle to the first main surface S1. In this case, the side surfaces S3 are inclined at an acute angle to the second main surface S2. The inclination angle of the side surfaces S3 relative to the first main surface S1 can be 100° or more and 135° or less, or 110° or more and 135° or less. When the electrolytic capacitor (anode terminal side) is viewed from the direction (D1), the above-mentioned inclination angle is the angle formed by the main surface S1 and the side surfaces S3. Figure 15 The outline of the side surface S3 of the protrusion 125 shown is straight, but the outline can also be a curved shape such as an arc with a slight bulge.

[0134] like Figure 16 As shown, the front end faces 125d of the two protrusions 125 can also be inclined at an obtuse angle to the first main surface S1. In this case, it is easy to form a good solder fillet, which can improve the connection strength between the anode terminal and the substrate. The inclination angle of the front end face 125d relative to the first main surface S1 can be 100° or more and 135° or less, or 110° or more and 135° or less.

[0135] Reference Figure 10 , Figure 11 Two anchoring portions 123 extend from two end edges 121e respectively. The two end edges 121e are the end edges of the anode terminal portion 121 (two second regions 121b), and are a pair of end edges extending in the direction D1 along the anode lead 112.

[0136] Reference Figure 10 , Figure 12Each of the two anchoring portions 123 includes an upright portion 123a that rises from the end edge 121e toward the upper surface 100t, and an extension portion 123b that extends from the upper end of the upright portion 123a by bending. In an example shown in the second embodiment, the two anchoring portions 123 are bent in different directions at the boundary between the anode terminal portion 121 and the upright portion 123a, and at the boundary between the upright portion 123a and the extension portion 123b. Specifically, one surface of the metal sheet constituting the anode lead terminal 120 (the surface on the upper surface 100t side) is bent in a valley shape at the boundary between the anode terminal portion 121 and the upright portion 123a, and in a mountain shape at the boundary between the upright portion 123a and the extension portion 123b. As a result, the extension portion 123b extends from the upper end of the upright portion 123a toward the outside of the electrolytic capacitor 100. That is, the extensions 123b of the two anchoring portions 123 are bent from the upper end of the upright portion 123a and extend in opposite directions in a direction (D2) perpendicular to the direction (D1) of the anode lead 112. The direction of extension of the extension 123b can also be approximately parallel to the bottom surface 100b, for example, the angle between the two is in the range of -20° to 20°.

[0137] The cathode lead terminal 130 includes a cathode terminal portion 131, a connecting portion 132, and two anchoring portions 133. The cathode terminal portion 131 is exposed on the bottom surface 100b. The connecting portion 132 is arranged with the cathode terminal portion 131 and a step. The connecting portion 132 is electrically connected to the cathode portion 115 (cathode layer 117) described later via a conductive member 141. That is, the cathode terminal portion 131 is electrically connected to the capacitor element 110 via the connecting portion 132 and the conductive member 141. The conductive member 141 is not particularly limited, and a known conductive member can be used. For example, the conductive member 141 can also be formed of metal paste or the like.

[0138] Two anchoring portions 133 extend from two end edges 131e respectively. The two end edges 131e are the end edges of the cathode terminal portion 131, and are a pair of end edges extending in the direction D1 along the anode lead 112.

[0139] Reference Figure 10 , Figure 13Each of the two anchoring portions 133 includes an upright portion 133a rising from the end edge 131e toward the upper surface 100t, and an extension portion 133b extending from the upper end of the upright portion 133a by bending. In an example shown in the second embodiment, the boundaries between the cathode terminal portion 131 and the upright portion 133a, and between the upright portion 133a and the extension portion 133b, are bent in different directions. That is, the extension portions 133b of the two anchoring portions 133 are bent from the upper end of the upright portion 133a and extend in mutually distancing directions in a direction (D2) perpendicular to the direction (D1) of the anode lead 112. The direction in which the extension portion 133b extends may also be substantially parallel to the bottom surface 100b, for example, the angle between them being in the range of -20° to 20°.

[0140] Reference Figure 12 The distance L1 from the surface of the anode terminal portion 121 to the lower surface of the extension portion 123b can also be 50 μm or more (e.g., 75 μm or more, 100 μm or more). By setting the distance L1 to 50 μm or more (e.g., 75 μm or more, 100 μm or more), it becomes easier to fill the lower part of the extension portion 123b with the outer packaging resin 101. Furthermore, in Figure 12 In the capacitor element 110, the upper surface of the extension portion 123b is located lower than the lower surface of the extension portion 123b. However, as long as the extension portion 123b does not interfere with the capacitor element 110, the extension portion 123b can also be located at a higher position.

[0141] Reference Figure 13 The distance L3 from the surface of the cathode terminal portion 131 to the lower surface of the extension portion 133b can be 50 μm or more (e.g., 75 μm or more, 100 μm or more), or it can be in the range of 50 μm to 500 μm (e.g., 75 μm to 200 μm). The distance L4 from the upper surface of the extension portion 133b to the lower surface of the capacitor element 110 can also be 50 μm or more (e.g., 75 μm or more, 100 μm or more), or it can be in the range of 50 μm to 500 μm (e.g., 75 μm to 200 μm). By setting the distances L1 and L3 to 50 μm or more (e.g., 75 μm or more, 100 μm or more), it becomes easier to fill the lower and upper parts of the extension portion 133b with the outer packaging resin 101.

[0142] The horizontal distance W1 (distance along direction D2) from end edge 121e to the front end of extension 123b and the horizontal distance W2 (distance along direction D2) from end edge 131e to the front end of extension 133b can both be 50 μm or more (e.g., 75 μm or more, 100 μm or more). By setting the horizontal distance W1 to this range, a high anchoring effect can be obtained. Furthermore, from the viewpoint of shape stability, processability, etc., the horizontal distances W1 and W2 can also be set to 200 μm or more.

[0143] Furthermore, the shapes of the anode lead terminal 120 and cathode lead terminal 130 described above are just examples and are not limited to the shapes described above. For example, either the anode lead terminal 120 or the cathode lead terminal 130 may not include the anchoring portion. In addition, as long as the connecting portion of the cathode lead terminal 130 is electrically connected to the cathode portion 115 (cathode layer 117), it may not be in the position shown in the figure, nor may it be in the shape shown in the figure.

[0144] Reference Figure 18 The two protrusions 125 may also replace the side surface S3 and have a side surface S4 that is inclined at an acute angle to the first main surface S1. In this case, the side surface S4 is inclined at an obtuse angle to the second main surface S2. In this case, the inclination angle of the side surface S4 relative to the first main surface S1 may be 45° or more and 80° or less, or 45° or more and 70° or less. Figure 18 The outline of the side surface S4 shown is a straight line, but it can also be a curved shape such as an arc with a slight bulge.

[0145] Reference Figure 17 The capacitor element 110 includes an anode portion 111 and a cathode portion 115. The anode portion 111 includes an anode body 113 on which a dielectric layer 114 is formed, and an anode lead 112. The cathode portion 115 includes an electrolyte layer 116 configured to cover the dielectric layer 114, and a cathode layer 117. The cathode layer 117 includes, for example, a carbon layer formed on the electrolyte layer 116 and a metal particle layer formed on the carbon layer. The metal particle layer is, for example, a layer formed using metal paste.

[0146] As described above, the anode portion 111 of the capacitor element 110 is electrically connected to the anode lead terminal 120, and the cathode portion 115 of the capacitor element 110 is electrically connected to the cathode lead terminal 130. When the electrolytic capacitor 100 is mounted on the substrate of an electronic device, it can also be mounted by soldering the anode terminal portion 121 and the cathode terminal portion 131 separately.

[0147] The following describes an example of a method for manufacturing an electrolytic capacitor 100. First, a capacitor element 110, an anode lead terminal 120, and a cathode lead terminal 130 are prepared. There are no particular limitations on the method for manufacturing the capacitor element 110, and it can be manufactured using known methods. The anode lead terminal 120 and the cathode lead terminal 130 can be formed using known metalworking methods.

[0148] Next, the anode lead 112 and the anode lead terminal 120 are connected, and the cathode layer 117 and the cathode lead terminal 130 are connected. The anode lead 112 and the anode lead terminal 120 can be connected by welding (e.g., laser welding). The connection between the cathode layer 117 and the cathode lead terminal 130 can be performed, for example, by the following method: First, a metal paste that serves as a conductive member 141 is applied to the surface of the connection portion 132 of the cathode lead terminal 130 and / or the surface of the cathode layer 117. Next, the cathode layer 117 and the connection portion 132 are bonded together via the metal paste, and the conductive member 141 is formed by curing the metal paste. In this way, the cathode layer 117 and the cathode lead terminal 130 can be connected.

[0149] Next, the capacitor element is sealed using a material (e.g., molding resin) of the outer packaging resin 101. The sealing process can be performed using known methods. Thus, the electrolytic capacitor 100 can be manufactured. Furthermore, other electrolytic capacitors disclosed herein can also be manufactured using the same method.

[0150] Industrial availability

[0151] This disclosure can be used for electrolytic capacitors that require high reliability.

[0152] Symbol Explanation

[0153] 100: Electrolytic capacitor

[0154] 100b: Bottom surface

[0155] 100t: Upper surface

[0156] 101: Outer Packaging Resin

[0157] 110: Capacitor Components

[0158] 112: Anode lead

[0159] 120: Anode lead terminal

[0160] 121: Anode terminal section

[0161] 121a: Region 1

[0162] 121b: Area 2

[0163] 121e, 131e: End edge

[0164] 121S, 131S: Main face

[0165] 123, 133: Anchorage section

[0166] 124, 134, 154: Area

[0167] 124S, 134S, 154S: Inclined surface

[0168] 123a, 133a, 153a: Erect part

[0169] 123b, 133b: Extension section

[0170] 125: Protrusion

[0171] 125d: Front end face

[0172] 130: Cathode lead terminal

[0173] 131: Cathode terminal section

[0174] 131e: End edge

[0175] 133a: Erect part

[0176] 133b: Extension Section

[0177] S1: 1st main surface

[0178] S2: Second Main Face

[0179] S3, S4: Side view

[0180] D1, D2: Direction.

Claims

1. An electrolytic capacitor having a bottom surface and an upper surface opposite to the bottom surface, the electrolytic capacitor comprising: Capacitor elements, including anode leads; The anode lead terminal and the cathode lead terminal are electrically connected to the capacitor element; and The outer packaging resin is disposed around the capacitor element. The anode lead terminal is made of metal sheet and includes an anode terminal portion having a first main surface and a second main surface opposite to the first main surface, and an anode connection portion electrically connected to the front end of the anode lead. The first main surface is exposed on the bottom surface. The anode terminal portion has a central first region, and two 2A regions and a 2B region on either side of the first region. The anode connection portion rises from the first region toward the upper surface. Region 2A and Region 2B each include a protrusion extending from Region 1, with its front end protruding from the end of the bottom surface. The protrusion in region 2A and the protrusion in region 2B each have a side surface connected to the first main surface and the second main surface, respectively. The side surface of the protrusion in region 2A and the side surface of the protrusion in region 2B are opposite to each other and are inclined in different directions relative to the first main surface and the second main surface.

2. The electrolytic capacitor according to claim 1, wherein, The side surface of the protrusion in region 2A and the side surface of the protrusion in region 2B are respectively inclined at an obtuse angle to the first main surface.

3. The electrolytic capacitor according to claim 2, wherein, The side of the protrusion in region 2A and the side of the protrusion in region 2B are inclined at an angle of more than 100° and less than 135° relative to the first main surface.

4. The electrolytic capacitor according to any one of claims 1 to 3, wherein, In the anode lead terminal, two anchoring portions extend from the 2A region and the 2B region respectively and are embedded in the outer packaging resin. Region 2A and region 2B each have an end edge along the long side of the anode lead. The two anchoring parts each include: an upright part that stands upright from the end edge toward the upper surface; and an extension part that extends bently from the upper end of the upright part.

5. The electrolytic capacitor according to claim 4, wherein, The entire surface of the extended portion is in contact with the outer packaging resin.

6. The electrolytic capacitor according to claim 4, wherein, The extension portion of one of the two anchoring portions and the extension portion of the other of the two anchoring portions extend in mutually distant directions.

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