Electrolytic capacitor

Abstract

An electrolytic capacitor having a bottom surface and an upper surface, comprising: a capacitor element including an anode lead, a cathode lead terminal, and an overmold resin. The cathode lead terminal includes: a cathode terminal portion having an exposed surface exposed at the bottom surface; and two cathode anchor portions extending from the cathode terminal portion and embedded in the overmold resin. The cathode terminal portion has two end edges along a long edge direction of the anode lead, and the two cathode anchor portions each include: a cathode upright portion standing up from an end edge of the cathode terminal portion toward the upper surface; a first extension portion extending from the cathode upright portion; and a second extension portion extending from the first extension 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 consists of anode and cathode leads that are electrically connected to the capacitor element, and an outer resin casing that covers the capacitor element.

[0003] Patent documents 1 and 2 disclose cathode lead terminals that facilitate the positioning of capacitor elements. Specifically, patent document 1 discloses a cathode lead terminal with both sides bent upwards to form an insert portion, and a capacitor element disposed in the insert portion. Patent document 2 discloses a cathode lead frame with a pair of opposing side portions, and a capacitor element disposed between the pair of side portions.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-068576

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-141208 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The lead terminal includes a terminal portion having an exposed surface that protrudes from the bottom surface of the electrolytic capacitor, which can serve as a bonding surface with a printed circuit board or the like. However, due to expansion of the lead terminal during reflow soldering, the terminal portion sometimes separates from the bottom surface of the electrolytic capacitor (the exposed surface of the terminal portion floats up from the bottom surface of the electrolytic capacitor), requiring improved terminal strength.

[0010] Methods for solving problems

[0011] One aspect of this disclosure relates to an electrolytic capacitor having a bottom surface and an upper surface opposite to the bottom surface. The electrolytic capacitor 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. The cathode lead terminal includes: a cathode terminal portion having an exposed surface exposed on the bottom surface; and two cathode anchor portions extending from the cathode terminal portion and embedded in the outer packaging resin. The cathode terminal portion has two end edges along the long side of the anode lead. The two cathode anchor portions each include: a cathode upright portion erected from the end edge of the cathode terminal portion toward the upper surface; a first extension portion extending from the cathode upright portion; and a second extension portion extending from the first extension portion. The first extension portion is bent from the upper end of the cathode upright portion, and the second extension portion erects toward the upper surface. The first extension of one of the two cathode anchor portions and the first extension of the other of the two cathode anchor portions extend in a direction that moves away from each other. The second extension of one of the two cathode anchor portions and the second extension of the other of the two cathode anchor portions are configured to clamp the capacitor element in a direction perpendicular to the long side direction of the anode lead.

[0012] Invention Effects

[0013] According to this disclosure, in an electrolytic capacitor, it is possible to suppress positional deviation of capacitor elements and improve terminal strength. Attached Figure Description

[0014] Figure 1 This is a perspective view schematically illustrating the structure of an example of the electrolytic capacitor of this disclosure.

[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 The cross-sectional view of the electrolytic capacitor shown. Detailed Implementation

[0020] The following description illustrates embodiments of the present disclosure using examples, but the present disclosure is not limited to these examples. In the following description, specific values ​​and materials are sometimes illustrated, but other values ​​and materials can be applied as long as the effects of the present disclosure are achieved. Furthermore, known components of electrolytic capacitors can be used for components other than those characteristic of the present disclosure.

[0021] (Electrolytic capacitor)

[0022] 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 comprising 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.

[0023] The cathode lead terminal includes a cathode terminal portion having an exposed surface exposed on the bottom surface (B), and two cathode anchor portions extending from the cathode terminal portion and embedded in the outer packaging resin. Hereinafter, the cathode lead terminal including the two cathode anchor portions is sometimes referred to as a "lead terminal (L)". The cathode terminal portion has two end edges extending along the direction D1 (long side direction of the anode lead) of the anode lead. The two cathode anchor portions each include a cathode upright portion that stands upright from the end edge of the cathode terminal portion toward the upper surface (T), and a first extension portion that bends and extends from the upper end of the cathode upright portion.

[0024] As described above, the cathode anchoring portion (cathode upright portion and cathode 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 cathode terminal portion and the cathode upright portion, and the boundary between the cathode upright portion and the first extension portion. According to this structure, the directions of extension of the cathode upright portion and the first extension portion are different.

[0025] Furthermore, the two cathode anchoring portions are bent in different directions (reverse rotation direction) at the boundaries between the cathode terminal portion and the cathode upright portion, and at the boundaries between the cathode upright portion and the first extension portion, respectively. Here, bending in different directions means that the metal sheet constituting the lead terminal (L) is bent such that one side of the metal sheet (the side facing the upper surface (T)) forms a valley at the boundary between the cathode terminal portion and the cathode upright portion, and bent such that one side forms a mountain at the boundary between the cathode upright portion and the first extension portion. More specifically, the first extension portions of the two cathode anchoring portions are bent from the upper end of the cathode upright portion and extend in mutually distancing directions. That is, the first extension portions of the two cathode anchoring portions are bent from the upper end of the cathode upright portion and extend in mutually distancing directions in a direction D2 perpendicular to the direction D1 of the anode lead extension.

[0026] It achieves a higher anchoring effect than two cathode anchoring portions (cathode upright portion and first extension portion), thus improving terminal strength. In particular, since the entire surface of the cathode upright portion is covered by the outer packaging resin, it can prevent the cathode terminal portion from separating from the outer packaging resin (bottom surface of the electrolytic capacitor).

[0027] Ideally, the area opposite the exposed surface of the cathode terminal should be in contact with the outer packaging resin. In this case, the outer packaging resin enters between the capacitor element and the cathode terminal, allowing the capacitor element to be more stably fixed by the outer packaging resin, and further suppressing the separation of the cathode terminal from the outer packaging resin, thus enhancing the anchoring effect.

[0028] The two cathode anchoring portions also include a second extension extending from the first extension. Hereinafter, the first and second extensions will sometimes be referred to together as cathode extensions. The second extensions of the two cathode anchoring portions each stand upright towards the upper surface (B). The second extension bends from the outer end of the first extension (the end opposite to the cathode upright portion) and extends towards the upper surface (B), with the directions of extension of the first and second extensions being different. Therefore, by further providing the second extension together with the first extension, the anchoring effect provided by the cathode anchoring portions can be further improved.

[0029] The second extensions of the two cathode anchoring portions are respectively positioned facing upwards towards the upper surface (B), and clamp the capacitor element in a direction D2 perpendicular to the direction D1 of the anode lead extension. The second extensions can suppress positional deviation of the capacitor element. Because of this, the two cathode anchoring portions can simultaneously serve the functions of positioning the capacitor element and preventing the cathode terminals from separating from the outer packaging resin.

[0030] There are no particular limitations on the size of the cathode anchoring portion, as long as it is a size that can achieve the anchoring effect. The two cathode anchoring portions included in one cathode lead terminal (L) are usually symmetrical in shape with respect to the plane that is perpendicular to the bottom surface (B) and passes through the central axis of the anode lead, but they may not be symmetrical.

[0031] In the electrolytic capacitor disclosed herein, the cathode lead terminal may also include a cathode connection portion extending from the cathode terminal portion and embedded in the outer packaging resin. The cathode connection portion is electrically connected to the cathode portion of the capacitor element. In this case, the cathode connection portion may be connected to the bottom surface of the capacitor element via a conductive adhesive layer, and the second extension portion may be connected to the side surface of the capacitor element via a conductive adhesive layer. In this case, the contact area between the capacitor element and the cathode lead terminal is increased, which is beneficial for reducing the equivalent series resistance (ESR). Furthermore, from the viewpoint of simplifying the manufacturing process and designing tolerances, the conductive adhesive layer may not be provided, and the second extension portion may be directly connected to the side surface of the capacitor element, or the second extension portion may be connected to the side surface of the capacitor element via the outer packaging resin.

[0032] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the cathode extension (except for the area in contact with the conductive adhesive layer, when the second extension is in contact with the side of the capacitor element via the conductive adhesive layer) is in contact with the outer packaging resin. In another viewpoint, in the electrolytic capacitor of this disclosure, it is preferable that the cathode anchoring portion is not in contact with the capacitor element. In this case, a high anchoring effect is easily obtained for the cathode lead terminals.

[0033] In the electrolytic capacitor of this disclosure, the anode lead terminal may also include an anode terminal portion having an exposed surface exposed on the bottom surface (B). Preferably, the anode lead terminal includes an anode connection portion extending from the anode terminal portion and embedded in the outer packaging resin, the anode connection portion being electrically connected to the anode lead. Preferably, the anode connection portion stands upright from the anode terminal portion toward the upper surface and has a groove at its upper end for receiving the front end of the anode lead. In this case, the groove of the anode connection portion can be used in conjunction with the second extension portions of the two cathode anchor portions to position the capacitor element. That is, the capacitor element can be positioned at two points: one point at the front end of the anode lead and two points on both sides of the capacitor element (two sides perpendicular to the bottom surface (B) and sandwiched in a direction D2 perpendicular to the direction D1 of the anode lead extension). The two sides of the capacitor element are sandwiched by the two second extension portions in the region at the end of the cathode anchor portion on the opposite side of the front end of the anode lead (above the cathode terminal portion), thereby effectively performing the above-mentioned positioning based on three points. This significantly improves the positioning accuracy of capacitor elements and effectively suppresses positional deviations of capacitor elements.

[0034] Without a cathode anchoring portion, if positioning sidewalls (sidewalls erected from both sides of the cathode connection portion) are provided on both sides of the cathode connection portion (described later), the anchoring effect is not as good as that of the cathode anchoring portion, and the separation of the cathode terminal portion from the outer packaging resin cannot be prevented. Compared to the aforementioned sidewalls, the second extension portion is located further from the front end of the anode lead, making it easier and more effective to position the capacitor element based on the three points described above.

[0035] In the electrolytic capacitor of this disclosure, the anode lead terminal may also include two anode anchoring portions. That is, the anode lead terminal may include an anode terminal portion having an exposed surface exposed on the bottom surface (B), and may also include two anode anchoring portions extending from the anode terminal portion and embedded in the outer packaging resin. The anode terminal portion has two end edges along the direction of extension of the anode lead, and the two anode anchoring portions may each include an anode upright portion rising from the end edge of the anode terminal portion toward the upper surface (T), and an anode extension portion extending from the upper end of the anode upright portion. A high anchoring effect can be obtained through the anode anchoring portions, and separation of the anode terminal portion from the outer packaging resin can be suppressed.

[0036] The two anode anchoring portions can also be bent in different directions (counter-rotation direction) at the boundaries of the anode terminal portion and the anode upright portion, and at the boundaries of the anode upright portion and the anode extension portion, respectively. Here, bending in different directions means that the metal sheet constituting the anode lead terminal is bent such that one side of the metal sheet (the side facing the upper surface (T)) forms a valley at the boundary between the anode terminal portion and the anode upright portion, and bent such that one side forms a mountain at the boundary between the anode upright portion and the anode extension portion. More specifically, the anode extension portions of the two anode anchoring portions can also be bent from the upper end of the anode upright portion and extend in directions away from each other. That is, the anode extension portions of the two anode anchoring portions can also be bent from the upper end of the anode upright portion and extend in directions away from each other in a direction perpendicular to the direction of anode lead extension. The formation of the anchoring portions with this structure is simple. Furthermore, when using anchoring portions with this structure, the material for filling the outer packaging resin (molding resin, etc.) is easier to obtain. In addition, the two anode anchoring parts can also be bent in the same direction (same rotation direction) at the boundary between the anode terminal part and the anode upright part and the boundary between the anode upright part and the anode extension part, respectively.

[0037] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the anode extension is in contact with the outer packaging resin. In this case, a high anchoring effect is easily obtained for the anode lead terminal. There is no particular limitation on the size of the anode anchoring portion, as long as it is a size that achieves the anchoring effect. The two anode anchoring portions included in one anode lead terminal are generally 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.

[0038] The following describes one example of the constituent elements of the electrolytic capacitor of this disclosure.

[0039] (Anode lead terminal)

[0040] 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, 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.). Nickel plating, gold plating, or other plating processes 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).

[0041] As described above, the anode lead terminal may also include an anode terminal portion exposed on the bottom surface (B) and an anode connection portion (hereinafter also referred to as a wire connection portion) rising 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 approximately 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 easy and reliable connection of the wire connection portion and the anode lead.

[0042] (Cathode lead terminal)

[0043] 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 material in an electrolytic capacitor. For example, a known material for cathode leads in electrolytic capacitors can be used. The cathode lead terminal can also be formed using a metal sheet exemplified as the material for the anode lead terminal.

[0044] (Capacitor element)

[0045] 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.

[0046] 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.

[0047] (Anode)

[0048] 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.

[0049] 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.

[0050] 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 immersing the anode body in a forming solution to anodize the surface of the anode body. Alternatively, the dielectric layer can be formed by heating the anode body in an oxygen-containing environment to oxidize the surface of the anode body.

[0051] (Anode lead)

[0052] 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.

[0053] (Electrolyte layer)

[0054] There are no particular limitations on the electrolyte layer; any electrolyte layer known to be used in solid electrolytic capacitors can be used. Alternatively, 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.

[0055] 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).

[0056] 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).

[0057] 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.

[0058] (Cathode layer)

[0059] 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.

[0060] 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.

[0061] (Outer packaging resin)

[0062] 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.).

[0063] Hereinafter, an example of an electrolytic capacitor of the present disclosure will be specifically described with reference to the accompanying drawings. The aforementioned constituent elements 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 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.

[0064] exist Figure 1 A perspective view of an electrolytic capacitor 100 is schematically shown in the figure. 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 this diagram, for ease of understanding, 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 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. Further, in... Figure 6 schematically shown Figure 1 A cross-sectional view of the electrolytic capacitor 100 shown. Figure 6 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 text, the outer packaging resin 101 is represented only by an outline indicated by dashed lines.

[0065] 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. The anode lead terminal 120 and the cathode lead terminal 130 are made of metal sheets.

[0066] Reference Figure 2 , Figure 3 , Figure 5 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 anode terminal portion 121 in the thickness direction is exposed on the bottom surface 100b, and the anode terminal portion 121 has a first main surface SP1 (exposed surface) exposed on the bottom surface 100b. The second main surface SP2 of the anode terminal portion 121, opposite to the first main surface SP1, is in contact with the outer packaging resin 101.

[0067] The wire connection portion 122 extends from the anode terminal portion 121 toward the upper surface 100t. The groove of the wire connection portion 122, which is used to receive 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, welding, etc.

[0068] Reference Figure 1 , Figure 2 Two anode 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.

[0069] Reference Figure 1 , Figure 3The two anode anchoring portions 123 each include an upright portion 123a rising from the end edge 121e toward the upper surface 100t and an extension portion 123b extending from the upper end of the upright portion 123a in a bent manner. The two anode 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°.

[0070] Reference Figure 2 , Figure 4 , Figure 5 The cathode lead terminal 130 includes a cathode terminal portion 131, a cathode connection portion 132, and two cathode anchor portions 133. A portion of the cathode terminal portion 131 in the thickness direction is exposed on the bottom surface 100b, and the cathode terminal portion 131 has a first main surface SN1 (exposed surface) exposed on the bottom surface 100b. The first main surface SN1 and the second main surface SN2 on the opposite side of the cathode terminal portion 131 are in contact with the outer packaging resin 101.

[0071] Reference Figure 2 , Figure 5 , Figure 6 The cathode connection portion 132 is provided with a cathode terminal portion 131 and a step, and is located slightly closer to the upper surface 100t from the cathode terminal portion 131. The bottom surface 100b is covered by an outer packaging resin 101. The cathode connection portion 132 is provided along the bottom surface 100b from one end edge of the cathode terminal portion 131 (the end edge that connects to the two end edges 131e described later) in a direction (D2) perpendicular to the direction (D1) extending from the anode lead 112.

[0072] The cathode connection portion 132 is electrically connected to the cathode portion 115 (cathode layer 117) described later via a conductive member 141 (conductive adhesive layer). That is, the cathode terminal portion 131 is electrically connected to the capacitor element 110 via the cathode connection portion 132 and the conductive member 141. The conductive member 141 is not particularly limited, and any known conductive member may be used. For example, the conductive member 141 may be formed from metal paste or the like.

[0073] Two cathode anchor 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.

[0074] Reference Figure 1 , Figure 4 The two cathode anchoring portions 133 each include an upright portion 133a that rises from the end edge 131e toward the upper surface 100t, a first extension portion 133b extending from the upright portion 133a, and a second extension portion 133c extending from the first extension portion 133b.

[0075] The first extensions 133b of the two cathode anchoring portions 133 are bent from the upper ends of the upright portion 133a and extend in opposite directions. The two cathode anchoring portions 133 are bent in different directions at the boundaries between the cathode terminal portion 131 and the upright portion 133a, and between the upright portion 133a and the first extension 133b. That is, the first extensions 133b of the two cathode anchoring portions 133 are bent from the upper ends of the upright portion 133a 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 first extension 133b extends may be approximately parallel to the bottom surface 100b, for example, the angle between them being in the range of -20° to 20°.

[0076] Reference Figure 1 , Figure 2 , Figure 4 as well as Figure 5 The second extensions 133c of the two cathode anchoring portions 133 are respectively positioned facing the upper surface 100t and clamp the capacitor element 110 in a direction (D2) perpendicular to the direction (D1) extending from the anode lead 112. The two sides 110a of the capacitor element 110 are clamped above the cathode terminal portion 131 by the two second extensions 133c. Alternatively, the direction in which the second extensions 133c extend may be approximately parallel to the direction perpendicular to the bottom surface 100b, for example, the angle between them being in the range of -20° to 20°. The second extensions 133c may be configured such that their upper ends reach a height equivalent to 10% to 60% of the height of the capacitor element 110. The width of the second extensions 133c may be, for example, 5% to 20% of the height of the capacitor element 110.

[0077] Reference Figure 3The 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 at a position lower than the lower surface of the capacitor element 110, but 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.

[0078] Reference Figure 4 The distance L3 from the surface of the cathode terminal portion 131 to the lower surface of the first 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 first 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 L3 and L4 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 first extension portion 133b with the outer packaging resin 101.

[0079] Reference Figure 4 The distance L2 between the second extension portion 133c and the side surface 110a of the capacitor element can be, for example, 80 μm or more, or within the range of 80 μm to 350 μm. When the distance L2 is within the above range, it is easy to suppress the positional deviation of the capacitor element and to easily arrange the capacitor element between the two second extension portions. Furthermore, when the second extension portion and the capacitor element are electrically connected via a conductive adhesive layer, it is easy to provide the conductive adhesive layer.

[0080] The horizontal distance W1 (distance along direction D2) from the end edge 121e to the front end of the extension 123b can also 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 distance W1 can also be set to 200 μm or more. The horizontal distance from the end edge 131e of the first extension 133b to the end on the side of the second extension 133c can also be greater than the horizontal distance W1.

[0081] 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, the anode lead terminal 120 may not include the anchoring portion. In addition, the connection portion of the cathode lead terminal 130 may not be in the position shown in the figure, or may not be the shape shown in the figure, as long as it is electrically connected to the cathode portion 115 (cathode layer 117). The second extension portion 133c may also be electrically connected to the cathode portion 115 (cathode layer 117) described later. The second extension portion 133c may also be connected to the side surface 110a of the capacitor element 110 via a conductive adhesive layer.

[0082] Reference Figure 6 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.

[0083] As described above, the anode portion 111 of capacitor element 110 is electrically connected to the anode lead terminal 120, and the cathode portion 115 of 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.

[0084] 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.

[0085] 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 cathode 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 cathode 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. Furthermore, the metal paste can also be used to bond the second extension portion 133c and the side surface 110a of the capacitor element.

[0086] 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 of this disclosure can also be manufactured using the same method.

[0087] Industrial availability

[0088] This disclosure can be used for electrolytic capacitors that require high reliability.

[0089] Explanation of reference numerals in the attached figures

[0090] 100: Electrolytic capacitor

[0091] 100b: Bottom surface

[0092] 100t: Upper surface

[0093] 101: Outer Packaging Resin

[0094] 110: Capacitor Components

[0095] 1 10a: Side view

[0096] 112: Anode lead

[0097] 120: Anode lead terminal

[0098] 121: Anode terminal section

[0099] 121e: End edge

[0100] 122: Wire connection part

[0101] 123: Anchorage section

[0102] 123a: Erect part

[0103] 123b: Extension Section

[0104] 130: Cathode lead terminal

[0105] 131: Cathode terminal section

[0106] 131e: End edge

[0107] 132: Cathode connection part

[0108] 133: Anchorage section

[0109] 133a: Erect part

[0110] 133b: First Extension

[0111] 133c: Second Extension

[0112] 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; as well as The outer packaging resin is disposed around the capacitor element. The cathode lead terminal includes: a cathode terminal portion having an exposed surface visible on the bottom surface; and two cathode anchor portions extending from the cathode terminal portion and embedded in the outer packaging resin. The cathode terminal portion has two end edges along the long side of the anode lead. The two cathode anchoring portions each include: a cathode upright portion, rising from the end edge of the cathode terminal portion toward the upper surface; a first extension portion, extending from the cathode upright portion; and a second extension portion, extending from the first extension portion. The first extension portion bends from the upper end of the cathode upright portion. The second extension stands upright toward the upper surface. The first extension portion of one of the two cathode anchor portions and the first extension portion of the other of the two cathode anchor portions extend in directions that are far apart from each other. The second extension of one of the two cathode anchors and the second extension of the other of the two cathode anchors are configured to clamp the capacitor element in a direction perpendicular to the long side direction of the anode lead.

2. The electrolytic capacitor according to claim 1, wherein, The entire surface of the first extension portion is in contact with the outer packaging resin.

3. The electrolytic capacitor according to claim 1 or 2, wherein, The area opposite to the exposed surface of the cathode terminal portion is in contact with the outer packaging resin.

4. The electrolytic capacitor according to claim 1 or 2, wherein, The cathode lead terminal also includes a cathode connection portion extending from the cathode terminal portion and embedded in the outer packaging resin. The cathode connection portion is connected to the bottom surface of the capacitor element via a conductive adhesive layer. The second extension is connected to the side of the capacitor element via a conductive adhesive layer.

5. The electrolytic capacitor according to claim 4, wherein, The surface of the second extension is in contact with the outer packaging resin in all areas except the area in contact with the conductive adhesive layer.

6. The electrolytic capacitor according to claim 1, wherein, The anode lead terminal includes: an anode terminal portion having an exposed surface exposed on the bottom surface; and an anode connection portion extending from the anode terminal portion and embedded in the outer packaging resin. The anode connection is electrically connected to the anode lead.

7. The electrolytic capacitor according to claim 6, wherein, The anode connection portion rises from the anode terminal portion toward the upper surface and has a groove at its upper end for receiving the front end of the anode lead.

8. The electrolytic capacitor according to claim 6 or 7, wherein, The anode terminal portion also includes two anode anchor portions extending from the anode terminal portion and embedded in the outer packaging resin. The anode terminal portion has two end edges along the long side of the anode lead. The two anode anchoring portions each include: an anode upright portion, which stands upright from the end edge of the anode terminal portion toward the upper surface; and an anode extension portion, which extends bently from the upper end of the anode upright portion.

9. The electrolytic capacitor according to claim 8, wherein, The entire surface of the anode extension is in contact with the outer packaging resin.

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