Electrolytic capacitors

Abstract

This electrolytic capacitor comprises a capacitor element having a bottom surface and an upper surface and including an anode lead, an electrode lead terminal, and an exterior resin. The electrode lead terminal is formed of a metal sheet, and includes a terminal portion partly exposed on the bottom surface, and two anchor portions extending from the terminal portion toward the inside of the exterior resin. The terminal portion has a major surface exposed on the bottom surface, and has an end side along the direction of extension of the anode lead. Each of the two anchor portions includes a rise portion rising from the end side of the terminal portion toward the upper surface, and an extending portion extending at an angle from an upper end of the rise portion. The rise portion includes a first region exposed from the bottom surface in the vicinity of a boundary with the end side. The first region has an inclined surface continuous with the major surface of the terminal portion. The inclined surface is inclined to form an obtuse angle with the major surface of the terminal portion.

Description

Technical Field

[0006] , , , , ,

[0005] ,

[0001] The present disclosure relates to an electrolytic capacitor.

Background Art

[0002] The electrolytic capacitor is mounted on various electronic devices. The electrolytic capacitor generally includes a capacitor element having an anode portion and a cathode portion, an anode lead terminal, a cathode lead terminal, and an exterior body covering the capacitor element. The anode lead terminal is electrically connected to the anode portion, and the cathode lead terminal is electrically connected to the cathode portion.

[0003]

[0003] Conventionally, lead terminals of various shapes have been proposed (for example, Patent Document 1). Patent Document 1 discloses a tantalum capacitor including an anode lead frame having an extension portion that serves to strengthen the fixing strength with a molding portion.

Prior Art Documents

Patent Documents

[0004] <​​​​​​​​​​​​An electrolytic capacitor relating to the first aspect of the present disclosure includes 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 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 which is partially exposed on the bottom surface and two anchor portions which extend from the terminal portion toward the interior of the outer resin. The terminal portion has a main surface which is exposed on the bottom surface, and the anode lead Long side It has an end edge aligned in the direction. Each of the two anchor portions includes an upright portion rising from the end edge of the terminal portion toward the upper surface, and an extended portion bending and extending from the upper end of the upright portion. The upright portion is exposed from the bottom surface near the boundary with the end edge. exposure Having an area, the upright portion exposure The region has an inclined surface that is connected to the main surface of the terminal portion, and the inclined surface is inclined at an obtuse angle with the main surface of the terminal portion.

[0007] According to the first aspect of this disclosure, in an electrolytic capacitor, it is possible to increase the strength of the terminals while also increasing the strength of the connection between the terminal portion and the printed circuit board, etc.

[0008] Furthermore, the anode lead frame described in Patent Document 1 includes an anode terminal portion with two support portions (protrusions). When mounting the tantalum capacitor onto a substrate, the anode terminal portion and the substrate are joined by solder. From the viewpoint of solder fillet formation, the tips of the two support portions are slightly exposed from the edge of the bottom surface of the tantalum capacitor.

[0009] However, resin burrs tend to remain between the tips of the two support parts during the formation of the molding. These resin burrs remaining between the tips of the two support parts tend to fall off when the tantalum capacitor is mounted to the substrate, often resulting in mounting defects (such as poor solder height).

[0010] An electrolytic capacitor according to a second aspect of the present disclosure includes 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 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 tip of the anode lead, the first main surface being exposed on the bottom surface. The anode terminal portion has a central first region and second A and second B regions on both sides of the first region. The anode connection portion rises from the first region toward the upper surface. The second A region and the second B region each extend from the first region and include a projection whose tip protrudes from the edge of the bottom surface. The projection of the second A region and the projection of the second B region each have sides connected to the first main surface and the second main surface, respectively. The side surface of the protrusion in the 2A region and the side surface of the protrusion in the 2B region face each other and are inclined in different directions with respect to the first main surface and the second main surface.

[0011] According to the second aspect of this disclosure, mounting defects of electrolytic capacitors can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic perspective view showing the configuration of an example of an electrolytic capacitor according to the first embodiment. [Figure 2] Figure 1 is a schematic perspective view showing some of the components of the electrolytic capacitor shown. [Figure 3] Figure 1 is a schematic cross-sectional view showing the anode lead terminal of the electrolytic capacitor. [Figure 4] Figure 1 is a schematic cross-sectional view showing the cathode lead terminals of the electrolytic capacitor. [Figure 5] This is a schematic bottom view of the electrolytic capacitor shown in Figure 1. [Figure 6]It is a cross-sectional view schematically showing the main part of the electrolytic capacitor shown in FIG. 1. [Figure 7] It is a cross-sectional view of the main part schematically showing the state where the anode terminal part of the electrolytic capacitor shown in FIG. 1 is connected to the substrate by solder. [Figure 8] It is a cross-sectional view schematically showing the electrolytic capacitor shown in FIG. 1. [Figure 9] It is a cross-sectional view schematically showing the main part of the configuration of another example of the electrolytic capacitor of the first embodiment. [Figure 10] It is a perspective view schematically showing an example of the electrolytic capacitor of the second embodiment. [Figure 11] It is a perspective view schematically showing some members of the electrolytic capacitor shown in FIG. 10. [Figure 12] It is a cross-sectional view schematically showing the anode lead terminal of the electrolytic capacitor shown in FIG. 10. [Figure 13] It is a cross-sectional view schematically showing the cathode lead terminal of the electrolytic capacitor shown in FIG. 10. [Figure 14] It is a bottom view schematically showing the electrolytic capacitor shown in FIG. 10. [Figure 15] It is a side view schematically showing the electrolytic capacitor when viewed from the direction (D1) of the electrolytic capacitor (anode terminal part side) shown in FIG. 10. [Figure 16] It is a side view of the main part schematically showing the electrolytic capacitor when viewed from the direction (D2) of the electrolytic capacitor (anode terminal part side) shown in FIG. 10. [Figure 17] It is a cross-sectional view schematically showing the electrolytic capacitor shown in FIG. 10. [Figure 18] It is a side view schematically showing another example of the electrolytic capacitor of the second embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0013] (First Embodiment) Hereinafter, a first embodiment of the present disclosure will be described with examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be exemplified, but other numerical values and materials may be applied as long as the effects of the present disclosure can be obtained. Note that components other than the characteristic parts of the present disclosure may be components of a known electrolytic capacitor.

[0014] (Electrolytic capacitor) The electrolytic capacitor of the present disclosure has a bottom surface and an upper surface opposite to the bottom surface. The bottom surface and the upper surface may hereinafter be referred to as "bottom surface (B)" and "upper surface (T)". The electrolytic capacitor of the present disclosure includes a capacitor element including an anode lead, anode lead terminals and cathode lead terminals electrically connected to the capacitor element, and an exterior resin disposed around the capacitor element.

[0015] At least one of the anode lead terminal and the cathode lead terminal is composed of a metal sheet, and includes a terminal portion partially exposed on the bottom surface (B) and two anchor portions extending from the terminal portion into the interior of the exterior resin. The lead terminal including the two anchor portions may be referred to as "lead terminal (L)". The terminal portion has a main surface exposed on the bottom surface (B). Hereinafter, the main surface may be referred to as "main surface (S1)".

[0016] The terminal portion has two end sides along the direction in which the anode lead extends (Longitudinal direction of the anode lead) Hereinafter, the direction may be referred to as "direction (D1)", and the direction perpendicular to direction (D1) may be referred to as "direction (D2)". Also, the end side may be referred to as "end side (E)". Each of the two anchor portions includes a standing portion rising from the end side (E) toward the upper surface (T) and an extending portion extending by bending from the upper end of the standing portion.

[0017] The upright portion (excluding the exposed area (A) described later) and the extended portion of the anchor are embedded in the outer 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 extended portion. With this configuration, the direction in which the upright portion extends and the direction in which the extended portion extends are different. Therefore, the anchor portion exhibits a high anchoring effect. Accordingly, according to this disclosure, it is possible to suppress the lead terminal (L) from separating from the outer resin. In other words, according to this disclosure, an electrolytic capacitor with high terminal strength and reliability can be obtained.

[0018] The upright portions of the two anchor sections each have a region exposed from the bottom surface (B) near the boundary with the edge (E). Hereinafter, this region may be referred to as the "exposed region (A)". The exposed region (A) can be formed when a portion of the terminal section in the thickness direction is exposed on the bottom surface (B) (the terminal section is positioned so that the main surface (S1) protrudes slightly beyond the outer surface of the exterior resin). The exposed region (A) can also function as a terminal section and, together with the terminal section, can become a solder joint with the substrate.

[0019] The exposed area (A) has an inclined surface that is connected to the main surface (S1). Hereinafter, this inclined surface may be referred to as the "inclined surface (S2)". The inclined surface (S2) is inclined at an obtuse angle to the main surface (S1). By providing the inclined surface (S2), a good solder fillet is more easily formed at the joint between the terminal and the substrate, thereby increasing the connection strength between the terminal and the substrate. The two anchor parts serve to improve the terminal strength through the anchoring effect, as well as to improve the connection strength of the terminal.

[0020] The two inclined surfaces (S2) are each formed along the end edge (E), and the two inclined surfaces (S2) are provided on both sides in the direction (D2) of the terminal portion. Therefore, the connection strength, especially in the direction (D2), can be effectively increased. Such two inclined surfaces (S2) can be formed by utilizing the rise from the end edge (E) of the upright portion of the two anchor portions. The upright portion may rise at approximately a right angle to the terminal portion (e.g., greater than 80° but less than 100°), or it may rise at an obtuse angle to the terminal portion (e.g., greater than 100° but less than 150°).

[0021] The inclination angle θ of the inclined surface (S2) with respect to the main surface (S1) is, for example, 135° to 175°, and may also be 145° to 165°. Here, the inclination angle θ is the angle formed between the main surface (S1) and the inclined surface (S2) in a cross section perpendicular to the direction (D1) of the electrolytic capacitor (a cross section including the terminal portion and the upright portion of the lead terminal (L)), 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 contour of the inclined surface (S2) may be straight or curved, such as a slightly bulging arc. In the case of a curved shape, the inclination angle θ refers to the angle formed between the line segment (chord) connecting the two ends of the curve (arc) and the main surface. 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 point where the upright portion begins to be exposed on the bottom surface (B).

[0022] There are no specific limitations on the size of the anchor section; any size that provides an effective anchoring effect is acceptable. Examples of anchor section sizes are explained below.

[0023] The two anchor portions included in a single lead terminal (L) are usually perpendicular to the bottom surface (B) and symmetrical with respect to a plane passing through the central axis of the anode lead, but they do not have to be symmetrical. If both the anode lead terminal and the cathode lead terminal include anchor portions, the shapes of the anchor portions of the anode lead terminal and the cathode lead terminal may be the same or different.

[0024] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the extended portion is in contact with the outer resin. In another view, it is preferable that the anchor portion is not in contact with the capacitor element in the electrolytic capacitor of this disclosure. With these configurations, a high anchoring effect can be obtained.

[0025] The two anchor portions may be bent in different directions (opposite rotation directions) at the boundary between the terminal portion and the upright portion, and at the boundary between the upright portion and the extended portion. Here, bending in different directions means that the metal sheet constituting the lead terminal (L) is bent such that one surface of the metal sheet (the surface on the upper (T) side) forms a valley at the boundary between the terminal portion and the upright portion, and the same surface forms a peak at the boundary between the upright portion and the extended portion. More specifically, the extended portions of the two anchor portions may each bend from the upper end of the upright portion and extend away from each other. That is, the extended portions of the two anchor portions may each bend from the upper end of the upright portion and extend away from each other in a direction perpendicular to the direction in which the anode lead extends. This configuration of anchor portions is easy to form. Also, when using this configuration of anchor portions, it is easy to fill them with exterior resin material (such as molding resin). Furthermore, the two anchor portions may be bent in the same direction (same rotational direction) at the boundary between the terminal portion and the upright portion, and at the boundary between the upright portion and the extended portion, respectively.

[0026] In the electrolytic capacitor of this disclosure, each of the anode lead terminal and the cathode lead terminal may include two anchor portions. This configuration provides an electrolytic capacitor with particularly high terminal strength and reliability. Alternatively, only the anode lead terminal may include two anchor portions, or only the cathode lead terminal may include two anchor portions.

[0027] The following describes an example of the components of the electrolytic capacitor of this disclosure.

[0028] (Anode lead terminal) The anode lead terminal may be formed by processing a single metal sheet using a known metalworking method. The material of the anode lead terminal can be any material that can be used for the anode lead terminal of an electrolytic capacitor. For example, a known material used for anode lead terminals in electrolytic capacitors may be used. The anode lead terminal may also be formed by processing a metal sheet (including metal plates and metal foils) made of metal (copper, copper alloy, etc.). The surface of the metal sheet may be plated with nickel plating, gold plating, or the like. The thickness of the metal sheet constituting the anode lead terminal may be in the range of 25 μm to 200 μm (for example, in the range of 25 μm to 100 μm).

[0029] The anode lead terminal may include an anode terminal portion exposed on the bottom surface (B) and a wire connection portion rising from the anode terminal portion toward the top surface (T). As described above, two anchor portions may 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 have a wire receiving portion at its tip that is bent to be substantially parallel to the bottom surface (B). The wire receiving portion may be bent toward the front surface of the capacitor element or be bent in the opposite direction. Here, the front surface of the capacitor element is the surface opposite to the end face of the capacitor element from which the wire protrudes. The wire receiving portion allows for reliable and easy connection between the wire connection portion and the anode lead.

[0030] (Cathode lead terminals) The cathode lead terminals may be formed by processing a single metal sheet using a known metalworking method. The material for the cathode lead terminals can be any material that can be used for the cathode lead terminals of an electrolytic capacitor. For example, a known material used for cathode lead terminals in electrolytic capacitors may be used. The cathode lead terminals may also be formed from the metal sheet exemplified as the material for the anode lead terminals.

[0031] The cathode lead terminal may 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 the connection portion. As described above, two anchor portions may extend from the cathode terminal portion.

[0032] (Capacitor element) There are no particular limitations on the capacitor element. Capacitor elements used in known solid electrolytic capacitors or capacitor elements having a similar configuration may be used. Furthermore, the electrolytic capacitor of this disclosure may include multiple capacitor elements. In that case, the anode portions of the multiple capacitors are electrically connected to the anode lead terminals.

[0033] An example capacitor element includes an anode and a cathode. The anode includes an anode body with a dielectric layer formed on its surface and an anode lead, and the cathode includes an electrolyte layer and a cathode layer. The electrolyte layer is disposed between the dielectric layer formed on the surface of the anode body and the cathode layer. These components are not particularly limited, and components used in known solid electrolytic capacitors may be used. Examples of these components are described below.

[0034] (Anode) For the anode, for example, a columnar (e.g., rectangular) porous sintered body obtained by sintering material particles may be used. Examples of the above particles include valve metal particles, alloy particles containing valve metal, and compound particles containing valve metal. These particles may be used individually or in mixtures of two or more types. Examples of valve metals include titanium (Ti), tantalum (Ta), and niobium (Nb). Alternatively, the anode may be formed by roughening the surface of a substrate containing valve metal (such as a foil or plate-shaped substrate) by etching or other means.

[0035] The anode portion may be manufactured by the following method. First, a portion of the anode lead is embedded in metal powder, which is the material for the anode body, and the metal powder is pressure-molded into a columnar shape (for example, a rectangular parallelepiped). Then, the anode body is formed by sintering the metal powder. In this way, an anode portion can be manufactured that includes the anode body and anode leads, some of which are embedded in the anode body.

[0036] There are no particular limitations on the dielectric layer formed on the surface of the anode, and it may be formed by known methods. For example, the dielectric layer may be formed by immersing the anode in a chemical solution and anodic oxidizing the surface of the anode. Alternatively, the dielectric layer may be formed by heating the anode in an oxygen-containing atmosphere and oxidizing the surface of the anode.

[0037] (Anode lead) The anode lead may be a wire made of metal (anode wire). Examples of materials for the anode lead include the valve metals mentioned above, copper, aluminum, and aluminum alloys. Part of the anode lead is embedded in the anode body, and the remaining part protrudes from the anode body. Although the anode lead is usually rod-shaped, it may also be plate-shaped.

[0038] (electrolyte layer) There are no particular limitations on the electrolyte layer, and an electrolyte layer used in known solid electrolytic capacitors may be applied. In this specification, the term "electrolyte layer" may be read as "solid electrolyte layer," and the term "electrolytic capacitor" may be read as "solid electrolytic capacitor." The electrolyte layer may be a laminate of two or more different electrolyte layers.

[0039] The electrolyte layer is positioned to cover at least a portion of the dielectric layer. The electrolyte layer may be formed using manganese compounds or conductive polymers. Examples of conductive polymers include polypyrrole, polythiophene, polyaniline, and their derivatives. These may be used individually or in combination. The conductive polymer may also be a copolymer of two or more monomers. A derivative of a conductive polymer refers to a polymer that uses a conductive polymer as its basic skeleton. For example, an example of a derivative of polythiophene is poly(3,4-ethylenedioxythiophene).

[0040] The conductive polymer may have a dopant added to it. The dopant can be selected depending on the conductive polymer, and known dopants may be used. Examples of dopants include naphthalene sulfonic acid, p-toluenesulfonic acid, polystyrene sulfonic acid, and their salts. One example of an electrolyte layer is formed using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrene sulfonic acid (PSS).

[0041] The electrolyte layer containing the conductive polymer may be formed by polymerizing the raw material monomers on the dielectric layer. Alternatively, it may be formed by coating the dielectric layer with a liquid containing the conductive polymer (and optionally a dopant) and then drying it.

[0042] (Cathode layer) The cathode layer may be a conductive layer formed on the electrolyte layer, for example, a conductive layer formed to cover the electrolyte layer. The cathode layer may include a carbon layer formed on the electrolyte layer and a metal paste layer formed on the carbon layer. The carbon layer may be formed of a conductive carbon material such as graphite and a resin. The metal paste layer may be formed of metal particles (e.g., silver particles) and a resin, for example, a silver paste.

[0043] The cathode layer is electrically connected to the cathode lead terminals. The cathode layer may be electrically connected to the cathode lead terminals via a conductive member. The conductive member may be formed of metal particles (e.g., silver particles) and resin, or it may be formed of silver paste, for example.

[0044] (Exterior resin) The outer resin is placed around the capacitor element so that the capacitor element is not exposed on the surface of the electrolytic capacitor. Furthermore, the outer resin insulates the anode lead terminal and the cathode lead terminal. Known outer resins used for electrolytic capacitors may be used for the outer resin. For example, the outer resin may be formed using an insulating resin material used for sealing capacitor elements. Examples of outer resin materials include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester. The outer resin may also contain substances other than resin (such as inorganic fillers).

[0045] Hereinafter, an example of an electrolytic capacitor according to the first embodiment of this disclosure will be specifically described with reference to the drawings. The components of the example electrolytic capacitor described below can be the components described above. Furthermore, the components of the example electrolytic capacitor described below can be modified based on the above description. In addition, the matters described below may be applied to the above embodiment. Furthermore, in the embodiment described below, components that are not essential to the electrolytic capacitor of this disclosure may be omitted.

[0046] Figure 1 schematically shows a perspective view of the electrolytic capacitor 100 of the first embodiment. Figure 2 schematically shows perspective views of the anode lead terminal 120 and cathode lead terminal 130 of the electrolytic capacitor 100 shown in Figure 1. Figure 3 shows a cross-sectional view of the anchor portion of the anode lead terminal 120. Figure 4 shows a cross-sectional view of the anchor portion of the cathode lead terminal 130. In Figures 3 and 4, for ease of understanding, the position of the capacitor element 110 is shown with a dotted line, and the outline of the outer resin 101 is shown with a solid line. Figures 3 and 4 show a cross-section perpendicular to the direction (D1) of the electrolytic capacitor 100. Figure 5 schematically shows a bottom view of the electrolytic capacitor 100 shown in Figure 1. In Figure 5, the portion embedded in the outer resin 101 is shown with a dotted line.

[0047] Figure 6 shows a cross-sectional view of the main part of the electrolytic capacitor 100 shown in Figure 1, near the boundary between the anode terminal portion 121 and the upright portion 123a. Figure 7 shows a cross-sectional view of the main part of the electrolytic capacitor 100 shown in Figure 1, showing the state in which the anode terminal portion 121 is connected to the substrate 202 by solder 201. Figures 6 and 7 are diagrams showing a cross-section perpendicular to the direction (D1) of the electrolytic capacitor 100. Furthermore, a schematic cross-sectional view of the electrolytic capacitor 100 shown in Figure 1 is shown in Figure 8. The cross-sectional view in Figure 8 is a cross-sectional view passing through the central axis of the anode lead (anode wire) 112. For ease of understanding, in the following diagrams, some components may be shown only by their outlines. For example, in Figure 1, the outer resin 101 is shown only by its outline represented by a dotted line.

[0048] 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 resin 101. The anode lead terminal 120 and the cathode lead terminal 130 are electrically connected to the capacitor element 110, respectively.

[0049] Referring to Figures 2, 5, and 6, the anode lead terminal 120 includes an anode terminal portion 121, a wire connection portion 122, and two anchor portions 123. A portion of the anode terminal portion 121 in the thickness direction (for example, about half the thickness of the anode terminal portion 121) is located on the bottom surface 10 0 It is exposed at b. The anode terminal portion 121 has a main surface 121S that is exposed at the bottom surface 100b. The wire connection portion 122 rises from the anode terminal portion 121 toward the top surface 100t. The groove portion of the wire connection portion 122 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 may be connected by welding, soldering, or the like.

[0050] Referring to Figures 1 and 2, the two anchor portions 123 each extend from two end edges 121e. The two end edges 121e are the ends of the anode terminal portion 121, and are a pair of ends along the direction D1 in which the anode lead 112 extends.

[0051] Referring to Figures 1 and 3, each of the two anchor portions 123 includes an upright portion 123a rising from the end edge 121e toward the upper surface 100t, and an extended portion 123b that bends and extends from the upper end of the upright portion 123a. In one example shown in the first embodiment, the two anchor 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 extended portion 123b. Specifically, one surface of the metal sheet constituting the anode lead terminal 120 (the surface on the upper surface 100t side) is valley-folded at the boundary between the anode terminal portion 121 and the upright portion 123a, and mountain-folded at the boundary between the upright portion 123a and the extended portion 123b. As a result, the extended portion 123b extends from the upper end of the upright portion 123a toward the outside of the electrolytic capacitor 100. In other words, the extended portions 123b of the two anchor portions 123 each bend from the upper end of the upright portion 123a and extend away from each other in a direction (D2) perpendicular to the direction (D1) in which the anode lead 112 extends. The direction in which the extended portions 123b extend is approximately parallel to the bottom surface 100b, and for example, the angle between the two may be in the range of -20° to 20°.

[0052] Referring to Figures 3, 5, and 6, the upright portions 123a of the two anchor portions 123 each have a region 124 exposed at the bottom surface 100b at the boundary with the end edge 121e. The region 124 has an inclined surface 124S that is connected to the main surface 121S, and the inclined surface 124S is inclined at an obtuse angle with the main surface 121S. Referring 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 having the inclined surface 124S makes it easier for the solder 201 to form a fillet, thereby increasing the adhesive strength.

[0053] Referring to Figure 6, the inclination angle θ of the inclined surface 124S with respect to the main surface 121S (θ in Figure 6) is, for example, 135° to 175°, or it may be 145° to 165°. Figure 6 shows a cross-section perpendicular to the direction (D1) of the electrolytic capacitor 100 (a cross-section including the anode terminal portion 121 and the upright portion 123a). The contour of the inclined surface 124S in Figure 6 is curved, and θ (inclination angle θ) in Figure 6 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 this curve, one end is the boundary between the inclined surface 124S and the main surface 121S (end side 121e), and the other end is the point where the upright portion 123a begins to be exposed on the bottom surface 100b.

[0054] The cathode lead terminal 130 includes a cathode terminal portion 131, a connection portion 132, and two anchor portions 133. A portion of the cathode terminal portion 131 in the thickness direction (for example, about half the thickness of the cathode terminal portion 131) is located on the bottom surface 10 0 It is exposed at b. The cathode terminal portion 131 has a main surface 131S that is exposed at the bottom surface 100b. The connecting portion 132 is arranged with a step between it and the cathode terminal portion 131. The connecting portion 132 is electrically connected to the cathode portion 115 (cathode layer 117), which will be 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 may be used. For example, the conductive member 141 may be formed from a metal paste or the like.

[0055] Each of the two anchor portions 133 extends from two end edges 131e. The two end edges 131e are the ends of the cathode terminal portion 131 and are a pair of ends aligned with the direction D1 in which the anode lead 112 extends.

[0056] Referring to Figures 1 and 4, each of the two anchor portions 133 includes an upright portion 133a rising from the end edge 131e toward the upper surface 100t, and an extended portion 133b that bends and extends from the upper end of the upright portion 133a. In one example shown in the first embodiment, the portions bend in different directions at the boundary between the cathode terminal portion 131 and the upright portion 133a, and at the boundary between the upright portion 133a and the extended portion 133b. That is, the extended portions 133b of the two anchor portions 133 each bend from the upper end of the upright portion 133a and extend away from each other in a direction (D2) perpendicular to the direction (D1) in which the anode lead 112 extends. The direction in which the extended portions 133b extend is approximately parallel to the bottom surface 100b, and the angle between them may be in the range of -20° to 20°, for example.

[0057] Referring to Figures 4 and 5, the upright portions 133a of the two anchor portions 133 each have a region 134 exposed at the bottom surface 100b at the boundary with the end edge 131e. Region 134 has an inclined surface 134S that is connected to the main surface 131S, and the inclined surface 134S is inclined at an obtuse angle with the main surface 131S. By providing region 134 having an inclined surface 134S, the same effect as when region 124 having an inclined surface 124S is provided.

[0058] In a cross-section perpendicular to the direction (D1) of the electrolytic capacitor 100 (a cross-section including the cathode terminal portion 131 and the upright portion 133a), the contour of the inclined surface 134S is curved, and the inclination angle θ of the inclined surface 134S with respect to the main surface 131S is shown in the same way as in the case of the inclined surface 124S. The inclination angle θ of the inclined surface 134S is, for example, 135° to 175°, and may also be 145° to 165°.

[0059] Referring to Figure 3, the distance L1 from the surface of the anode terminal portion 121 to the lower surface of the extension portion 123b may be 50 μm or more (for example, 75 μm or more or 100 μm or more). Setting the distance L1 to 50 μm or more (for example, 75 μm or more or 100 μm or more) makes it easier to fill the lower part of the extension portion 123b with the exterior resin 101. In Figure 3, the upper surface of the extension portion 123b is located below the lower surface of the capacitor element 110, but the extension portion 123b may be located at a higher position as long as it does not interfere with the capacitor element 110.

[0060] Referring to Figure 4, the distance L3 from the surface of the cathode terminal portion 131 to the lower surface of the extension portion 133b may be 50 μm or more (for example, 75 μm or more or 100 μm or more), or it may be in the range of 50 μm to 500 μm (for example, in the range of 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 may be 50 μm or more (for example, 75 μm or more or 100 μm or more), or it may be in the range of 50 μm to 500 μm (for example, in the range of 75 μm to 200 μm). By setting distances L1 and L3 to 50 μm or more (for example, 75 μm or more or 100 μm or more), it becomes easier to fill the lower and upper parts of the extension portion 133b with the exterior resin 101.

[0061] The horizontal distance W1 (distance along direction D2) from the end edge 121e to the tip of the extended portion 123b, and the horizontal distance W2 (distance along direction D2) from the end edge 131e to the tip of the extended portion 133b, may each be 50 μm or more (for example, 75 μm or more or 100 μm or more). By setting the horizontal distance W1 within this range, a high anchoring effect can be obtained. Furthermore, from the viewpoint of shape stability and workability, the horizontal distances W1 and W2 may each be 200 μm or more.

[0062] The shapes of the anode lead terminal 120 and cathode lead terminal 130 described above are examples only and are not limited to those shapes. For example, either the anode lead terminal 120 or the cathode lead terminal 130 does not need to include an anchor portion. Also, the connection portion of the cathode lead terminal 130 does not need to be in the position shown in the figure, nor does it need to be in the shape shown in the figure, as long as it is electrically connected to the cathode portion 115 (cathode layer 117).

[0063] The upright portion 123a rises almost perpendicular to the anode terminal portion 121 (for example, more than 80° and less than 100°), but as shown in Figure 9, the upright portion 153a may be inclined to form an obtuse angle with respect to the anode terminal portion 121. The upright portion 153a may rise at an obtuse angle with respect to the anode terminal portion 121, for example, between 100° and 150°. By changing the degree of inclination of the upright portion 153a with respect to the anode terminal portion 121, the degree of inclination of the inclined surface 154S in the region 154 of the upright portion 153a that is exposed at the bottom surface 100b at the boundary with the end edge 121e may be adjusted. That is, the inclination angle θ of the inclined surface 154S with respect to the main surface 121S (in Figure 9, the angle θ formed by the line segment L2 connecting both ends of the curve of the contour of the inclined surface 154S and the main surface 121S) may be adjusted. Similarly, the upright portion of the cathode lead terminal may also be inclined to form an obtuse angle with the cathode terminal portion.

[0064] Referring to 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 on its surface, and an anode lead 112. The cathode portion 115 includes an electrolyte layer 116 arranged 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 a metal paste.

[0065] 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 mounting the electrolytic capacitor 100 on a circuit board or the like of an electronic device, it may be mounted by soldering the anode terminal portion 121 and the cathode terminal portion 131, respectively.

[0066] An example of a manufacturing method for the electrolytic capacitor 100 is described below. First, the capacitor element 110, the anode lead terminal 120, and the cathode lead terminal 130 are prepared. There are no particular limitations on the manufacturing method of the capacitor element 110, and it can be manufactured by known methods. The anode lead terminal 120 and the cathode lead terminal 130 can be formed by known metalworking methods.

[0067] 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 cathode layer 117 and the cathode lead terminal 130 can be connected by, for example, the following method. First, a metal paste that will become 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 metal paste is hardened to become a conductive member 141. In this way, the cathode layer 117 and the cathode lead terminal 130 can be connected.

[0068] Next, the capacitor element is sealed with an outer resin 101 material (e.g., molding resin). The sealing process can be carried out by known methods. In this way, the electrolytic capacitor 100 can be manufactured. Other electrolytic capacitors of this disclosure can also be manufactured by similar manufacturing methods.

[0069] (Second embodiment) The following describes a second embodiment of the present disclosure with examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be given as examples, but other numerical values ​​and materials may be applied as long as the effects of the present disclosure are obtained. In addition, components other than those characteristic of the present disclosure may be replaced with components of known electrolytic capacitors.

[0070] (Electrolytic capacitor) The electrolytic capacitor of this disclosure has a bottom surface and an upper surface opposite to the bottom surface. The bottom surface and upper surface may hereinafter 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 resin disposed around the capacitor element. Hereinafter, the direction in which the anode lead extends (Longitudinal direction of the anode lead) This is sometimes referred to as "direction (D1)". The direction perpendicular to the direction in which the anode lead extends is sometimes referred to as "direction (D2)".

[0071] 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 on the opposite side (back side) of the first main surface, and an anode connection portion electrically connected to the tip of the anode lead. The first main surface is exposed at the bottom surface (B). From the viewpoint of solder fillet formation, a portion of the anode terminal portion in the thickness direction may be exposed at the bottom surface (B).

[0072] The anode terminal section has a central first region and second A and second B regions on either side of the first region. The anode connection section is arranged to rise from the first region toward the top surface (T). The second A and second B regions each extend from the first region and include protrusions whose tips protrude from the edge of the bottom surface (B). The protrusions of the second A region and the second B region usually extend from the first region in direction (D1). From the viewpoint of solder fillet formation, the anode terminal section is arranged such that when the electrolytic capacitor is viewed from the bottom surface (B) side, the tips of the protrusions protrude slightly from the edge of the bottom surface (B). The second main surface is exposed at the tips of the protrusions and in contact with the outer resin in areas other than the tips of the protrusions.

[0073] The protrusions in region 2A and region 2B each have sides that are connected to the first and second main surfaces, respectively. Hereinafter, these sides will be referred to as "sides (S)". The sides (S) of the protrusions in region 2A and region 2B face each other and are inclined in different directions with respect to the first and second main surfaces. That is, the two side surfaces (S) are inclined in different directions from the first 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 during processes after the formation of the outer resin (such as the process of separating each capacitor element or the process of cutting the anode lead terminals), the resin burrs remaining between the tips of the two protrusions (side surfaces (S)) easily fall off. Therefore, the retention of resin burrs and the resulting mounting defects of electrolytic capacitors are suppressed.

[0074] Preferably, the side surfaces (S) of the protrusions in the second A region and the side surfaces (S) of the protrusions in the second B region are inclined at an obtuse angle with respect to the first main surface. In this case, the side surfaces (S) are inclined at an acute angle with respect to the second main surface. In this case, a good solder fillet is easily formed, and the connection strength between the anode terminal and the substrate is increased. In this case, the inclination angle of the side surfaces (S) with respect to the first main surface may 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 mounting defects and improving connection strength.

[0075] The inclination angle of the side surface (S) with respect to the first main surface is the angle formed between the first main surface and the side surface (S) when the electrolytic capacitor (anode terminal side) is viewed from direction (D1). When the electrolytic capacitor (anode terminal side) is viewed from direction (D1), the contour of the side surface (S) may be straight or curved, such as a slightly bulging arc. If the contour of the side surface (S) is curved, the inclination angle refers to the angle formed between the line segment (chord) connecting the two ends of the curve (arc) and the first main surface.

[0076] The side surfaces (S) of the protrusions in the second A region and the second B region may each be inclined to form an acute angle with respect to the first main surface. In this case, the side surfaces (S) are inclined to form an obtuse angle with respect to the second main surface. In this case, it is easier to secure a large bonding area between the anode terminal and the substrate. From the viewpoint of securing a bonding area between the anode terminal and the substrate and suppressing mounting defects, the inclination angle of the side surfaces (S) with respect to the first main surface may be 45° or more and 80° or less, or 45° or more and 70° or less.

[0077] The second A region and the second B region (excluding the protrusions) are usually symmetrical with respect to a plane perpendicular to the bottom surface (B) and passing through the central axis of the anode lead, but they do not have to be symmetrical. The protrusions of the second A region and the second B region are usually symmetrical with respect to a plane perpendicular to the bottom surface (B) and passing through the central axis of the anode lead.

[0078] At least one of the anode lead terminals and cathode lead terminals may include a terminal portion having a main surface exposed on the bottom surface (B), and two anchor portions extending from the terminal portion (in the case of the anode terminal portion, the second A region and the second B region) and embedded in the outer resin. Hereinafter, the lead terminal including the two anchor portions may be referred to as the "lead terminal (L)". The terminal portion (in the case of the anode terminal portion, the second A region and the second B region) may have two end edges along the direction D1 in which the anode lead extends. Each of the two anchor portions may include an upright portion rising from the end edge of the terminal portion (in the case of the anode terminal portion, the second A region and the second B region) toward the top surface (T), and an extended portion bending and extending from the upper end of the upright portion.

[0079] As described above, the anchor portion (upright portion and extended portion) is embedded in the outer 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 extended portion. With this configuration, the direction in which the upright portion extends and the direction in which the extended portion extends are different. Therefore, the anchor portion exhibits a high anchoring effect. Thus, separation of the lead terminal (L) (terminal portion) from the outer resin is suppressed, and the terminal strength is increased.

[0080] There are no specific limitations on the size of the anchor section; any size that provides an effective anchoring effect is acceptable. Examples of anchor section sizes are explained below.

[0081] The two anchor portions included in a single lead terminal (L) are usually perpendicular to the bottom surface (B) and symmetrical with respect to a plane passing through the central axis of the anode lead, but they do not have to be symmetrical. If both the anode lead terminal and the cathode lead terminal include anchor portions, the shapes of the anchor portions of the anode lead terminal and the cathode lead terminal may be the same or different.

[0082] In the electrolytic capacitor of this disclosure, it is preferable that the entire surface of the extended portion is in contact with the outer resin. In another view, it is preferable that the anchor portion is not in contact with the capacitor element in the electrolytic capacitor of this disclosure. With these configurations, a high anchoring effect can be obtained.

[0083] The two anchor portions may be bent in different directions (opposite rotation directions) at the boundary between the terminal portion and the upright portion, and at the boundary between the upright portion and the extended portion. Here, bending in different directions means that the metal sheet constituting the lead terminal (L) is bent such that one surface of the metal sheet (the surface on the upper surface (T) side) forms a valley at the boundary between the terminal portion and the upright portion, and the same surface forms a peak at the boundary between the upright portion and the extended portion. More specifically, the extended portions of the two anchor portions may each bend from the upper end of the upright portion and extend in a direction away from each other. That is, the extended portions of the two anchor portions may each bend from the upper end of the upright portion and extend in a direction away from each other with respect to a direction (D2) perpendicular to the direction (D1) in which the anode lead extends. This configuration of anchor portions is easy to form. Also, when using this configuration of anchor portions, it is easy to fill them with exterior resin material (such as molding resin). Furthermore, the two anchor portions may be bent in the same direction (same rotational direction) at the boundary between the terminal portion and the upright portion, and at the boundary between the upright portion and the extended portion, respectively.

[0084] In the electrolytic capacitor of this disclosure, each of the anode lead terminal and the cathode lead terminal may include two anchor portions. This configuration provides an electrolytic capacitor with particularly high terminal strength and reliability. Alternatively, only the anode lead terminal may include two anchor portions, or only the cathode lead terminal may include two anchor portions.

[0085] The following describes an example of the components of the electrolytic capacitor of this disclosure.

[0086] (Anode lead terminal) The anode lead terminal may be formed by processing a single metal sheet using a known metalworking method. The material of the anode lead terminal can be any material that can be used for the anode lead terminal of an electrolytic capacitor. For example, a known material used for anode lead terminals in electrolytic capacitors may be used. The anode lead terminal may also be formed by processing a metal sheet (including metal plates and metal foils) made of metal (copper, copper alloy, etc.). The surface of the metal sheet may be plated with nickel plating, gold plating, or the like. The thickness of the metal sheet constituting the anode lead terminal may be in the range of 25 μm to 200 μm (for example, in the range of 25 μm to 100 μm).

[0087] The anode lead terminal may include an anode terminal portion exposed on the bottom surface (B) and a wire connection portion (anode connection portion) rising from the anode terminal portion toward the top surface (T). As described above, two anchor portions may extend from the anode terminal portion (second A region and second B region). The anode lead of the capacitor element is connected to the wire connection portion. The wire connection portion may have a wire receiving portion at its tip that is bent to be substantially parallel to the bottom surface (B). The wire receiving portion may be bent toward the front surface of the capacitor element or be bent in the opposite direction. Here, the front surface of the capacitor element is the surface opposite to the end face of the capacitor element from which the wire protrudes. The wire receiving portion allows for reliable and easy connection between the wire connection portion and the anode lead.

[0088] (Cathode lead terminals) The cathode lead terminals may be formed by processing a single metal sheet using a known metalworking method. The material for the cathode lead terminals can be any material that can be used for the cathode lead terminals of an electrolytic capacitor. For example, a known material used for cathode lead terminals in electrolytic capacitors may be used. The cathode lead terminals may also be formed from the metal sheet exemplified as the material for the anode lead terminals.

[0089] The cathode lead terminal may 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 the connection portion. As described above, two anchor portions may extend from the cathode terminal portion.

[0090] (Capacitor element) There are no particular limitations on the capacitor element. Capacitor elements used in known solid electrolytic capacitors or capacitor elements having a similar configuration may be used. Furthermore, the electrolytic capacitor of this disclosure may include multiple capacitor elements. In that case, the anode portions of the multiple capacitors are electrically connected to the anode lead terminals.

[0091] One example of a capacitor element includes an anode and a cathode. The anode includes an anode body with a dielectric layer formed on its surface and an anode lead, and the cathode includes an electrolyte layer and a cathode layer. The electrolyte layer is disposed between the dielectric layer formed on the surface of the anode body and the cathode layer. These components are not particularly limited, and components used in known solid electrolytic capacitors may be used. Examples of these components are the same as those described in the first embodiment, so their description is omitted.

[0092] (Exterior resin) The outer resin is placed around the capacitor element so that the capacitor element is not exposed on the surface of the electrolytic capacitor. Furthermore, the outer resin insulates the anode lead terminal and the cathode lead terminal. Known outer resins used for electrolytic capacitors may be used for the outer resin. For example, the outer resin may be formed using an insulating resin material used for sealing capacitor elements. Examples of outer resin materials include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester. The outer resin may also contain substances other than resin (such as inorganic fillers).

[0093] Hereinafter, an example of an electrolytic capacitor according to a second embodiment of the present disclosure will be specifically described with reference to the drawings. The components of the example electrolytic capacitor described below can be the components described above. Furthermore, the components of the example electrolytic capacitor described below can be modified based on the above description. In addition, the matters described below may be applied to the above embodiments. Furthermore, in the embodiments described below, components that are not essential to the electrolytic capacitor of the present disclosure may be omitted. In the following drawings, components similar to those in the example electrolytic capacitor of the first embodiment are denoted by the same reference numerals.

[0094] Figure 10 schematically shows a perspective view of the electrolytic capacitor 100 of the second embodiment. Figure 11 schematically shows perspective views of the anode lead terminal 120 and cathode lead terminal 130 of the electrolytic capacitor 100 shown in Figure 10. Figure 12 shows a cross-sectional view of the anchor portion of the anode lead terminal 120. Figure 13 shows a cross-sectional view of the anchor portion of the cathode lead terminal 130. In Figures 12 and 13, the position of the capacitor element 110 is indicated by a dotted line. Figure 14 schematically shows a bottom view of the electrolytic capacitor 100 shown in Figure 10. In Figure 14, the portion embedded in the outer resin 101 is indicated by a dotted line. Figure 15 schematically shows a side view of the electrolytic capacitor (anode terminal side) shown in Figure 10 when viewed from direction (D1). Figure 16 schematically shows a side view of the main part of the electrolytic capacitor (anode terminal side) shown in Figure 10 when viewed from direction (D2). Furthermore, a schematic cross-sectional view of the electrolytic capacitor 100 shown in Figure 10 is shown in Figure 17. The cross-sectional view in Figure 17 is a cross-sectional view passing through the central axis of the anode lead (anode wire) 112. For ease of understanding, some components may be shown only by their outlines in the following figures. For example, in Figure 10, the outer resin 101 is shown only by its outline, represented by a dotted line.

[0095] 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 resin 101. The anode lead terminal 120 and the cathode lead terminal 130 are electrically connected to the capacitor element 110, respectively.

[0096] Referring to Figures 11, 14, and 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 anchor portions 123. Anode terminal Department 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 at the bottom surface 100b. A portion of the anode terminal portion 121 in the thickness direction is exposed at the bottom surface 100b. The wire connection portion 122 rises from the anode terminal portion 121 toward the top surface 100t. The groove portion of the wire connection portion 122 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 may be connected by welding, soldering, or other means.

[0097] Referring to Figure 14, the anode terminal portion 121 has a central first region 121a and two second regions 121b (second A region and second B region) on either side of the first region 121a. With respect to the direction (D1) in which the anode lead 112 extends, the two second regions 121b each extend from the first region 121a and include a projection 125 whose tip protrudes from the edge of the bottom surface 100b. Referring to Figure 15, the projections 125 of the two second regions 121b each have a side surface S3 that is connected to the first main surface S1 and the second main surface S2. The side surfaces S3 of the projections 125 of the two second regions 121b face each other and are inclined in different directions with respect to the first main surface S1 and the second main surface S2. In other words, the sides S3 of the two protrusions 125 are inclined in different directions from each other, from the first main surface S1 to the second main surface S2.

[0098] Referring to Figure 15, the side surfaces S3 of the protrusions 125 of the two second regions 121b are inclined at an obtuse angle with respect to the first main surface S1. In this case, the side surface S3 is inclined at an acute angle with respect to the second main surface S2. The inclination angle of the side surface S3 with respect to the first main surface S1 may be 100° or more and 135° or less, or 110° or more and 135° or less. The above inclination angle is the angle formed by the main surface S1 and the side surface S3 when the electrolytic capacitor (anode terminal side) is viewed from direction (D1). The contour of the side surface S3 of the protrusion 125 shown in Figure 15 is straight, but the contour may be a curved shape such as a slightly bulging arc.

[0099] As shown in Figure 16, the tip surfaces 125d of the two protrusions 125 may also be inclined to form an obtuse angle with the first main surface S1. In this case, a good solder fillet is easily formed, and the connection strength between the anode terminal and the substrate is increased. The inclination angle of the tip surface 125d with respect to the first main surface S1 may be 100° or more and 135° or less, or 110° or more and 135° or less.

[0100] Referring to Figures 10 and 11, the two anchor portions 123 each extend from two end edges 121e. The two end edges 121e are the ends of the anode terminal portion 121 (two second regions 121b) and are a pair of ends along the direction D1 in which the anode lead 112 extends.

[0101] Referring to Figures 10 and 12, each of the two anchor portions 123 includes an upright portion 123a rising from the end edge 121e toward the upper surface 100t, and an extended portion 123b that bends and extends from the upper end of the upright portion 123a. In one example shown in the second embodiment, each of the two anchor portions 123 is 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 extended portion 123b. Specifically, one surface of the metal sheet constituting the anode lead terminal 120 (the surface on the upper surface 100t side) is valley-folded at the boundary between the anode terminal portion 121 and the upright portion 123a, and mountain-folded at the boundary between the upright portion 123a and the extended portion 123b. As a result, the extended portion 123b extends from the upper end of the upright portion 123a toward the outside of the electrolytic capacitor 100. In other words, the extended portions 123b of the two anchor portions 123 each bend from the upper end of the upright portion 123a and extend away from each other in a direction (D2) perpendicular to the direction (D1) in which the anode lead 112 extends. The direction in which the extended portions 123b extend is approximately parallel to the bottom surface 100b, and for example, the angle between the two may be in the range of -20° to 20°.

[0102] The cathode lead terminal 130 includes a cathode terminal portion 131, a connecting portion 132, and two anchor portions 133. The cathode terminal portion 131 is exposed on the bottom surface 100b. The connecting portion 132 is positioned with a step between it and the cathode terminal portion 131. The connecting portion 132 is electrically connected to the cathode portion 115 (cathode layer 117), which will be 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 may be used. For example, the conductive member 141 may be formed from a metal paste or the like.

[0103] Each of the two anchor portions 133 extends from two end edges 131e. The two end edges 131e are the ends of the cathode terminal portion 131 and are a pair of ends aligned with the direction D1 in which the anode lead 112 extends.

[0104] Referring to Figures 10 and 13, each of the two anchor portions 133 includes an upright portion 133a rising from the end edge 131e toward the upper surface 100t, and an extended portion 133b that bends and extends from the upper end of the upright portion 133a. In one example shown in the second embodiment, the boundary between the cathode terminal portion 131 and the upright portion 133a, and the boundary between the upright portion 133a and the extended portion 133b are bent in different directions. That is, the extended portions 133b of the two anchor portions 133 each bend from the upper end of the upright portion 133a and extend away from each other in a direction (D2) perpendicular to the direction (D1) in which the anode lead 112 extends. The direction in which the extended portions 133b extend is approximately parallel to the bottom surface 100b, and the angle between them may be in the range of -20° to 20°, for example.

[0105] Referring to Figure 12, the distance L1 from the surface of the anode terminal portion 121 to the lower surface of the extended portion 123b may be 50 μm or more (for example, 75 μm or more or 100 μm or more). Setting the distance L1 to 50 μm or more (for example, 75 μm or more or 100 μm or more) makes it easier to fill the lower part of the extended portion 123b with the exterior resin 101. In Figure 12, the upper surface of the extended portion 123b is located below the lower surface of the capacitor element 110, but the extended portion 123b may be located at a higher position as long as it does not interfere with the capacitor element 110.

[0106] Referring to Figure 13, the distance L3 from the surface of the cathode terminal portion 131 to the lower surface of the extended portion 133b may be 50 μm or more (for example, 75 μm or more or 100 μm or more), or it may be in the range of 50 μm to 500 μm (for example, in the range of 75 μm to 200 μm). The distance L4 from the upper surface of the extended portion 133b to the lower surface of the capacitor element 110 may be 50 μm or more (for example, 75 μm or more or 100 μm or more), or it may be in the range of 50 μm to 500 μm (for example, in the range of 75 μm to 200 μm). By setting distances L1 and L3 to 50 μm or more (for example, 75 μm or more or 100 μm or more), it becomes easier to fill the lower and upper parts of the extended portion 133b with the exterior resin 101.

[0107] The horizontal distance W1 (distance along direction D2) from the end edge 121e to the tip of the extended portion 123b, and the horizontal distance W2 (distance along direction D2) from the end edge 131e to the tip of the extended portion 133b, may each be 50 μm or more (for example, 75 μm or more or 100 μm or more). By setting the horizontal distance W1 within this range, a high anchoring effect can be obtained. Furthermore, from the viewpoint of shape stability and workability, the horizontal distances W1 and W2 may each be 200 μm or more.

[0108] The shapes of the anode lead terminal 120 and cathode lead terminal 130 described above are examples only and are not limited to those shapes. For example, either the anode lead terminal 120 or the cathode lead terminal 130 does not need to include an anchor portion. Also, the connection portion of the cathode lead terminal 130 does not need to be in the position shown in the figure, nor does it need to be in the shape shown in the figure, as long as it is electrically connected to the cathode portion 115 (cathode layer 117).

[0109] Referring to Figure 18, each of the two protrusions 125 may have a side surface S4 instead of a side surface S3, which is inclined to form an acute angle with the first main surface S1. In this case, the side surface S4 is inclined to form an obtuse angle with the second main surface S2. In this case, the inclination angle of the side surface S4 with respect to the first main surface S1 may be 45° or more and 80° or less, or 45° or more and 70° or less. The contour of the side surface S4 shown in Figure 18 is straight, but the contour may be curved, such as a slightly bulging arc.

[0110] Referring to 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 on its surface, and an anode lead 112. The cathode portion 115 includes an electrolyte layer 116 arranged 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 a metal paste.

[0111] 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 mounting the electrolytic capacitor 100 on a circuit board or the like of an electronic device, it may be mounted by soldering the anode terminal portion 121 and the cathode terminal portion 131, respectively.

[0112] An example of a manufacturing method for the electrolytic capacitor 100 is described below. First, the capacitor element 110, the anode lead terminal 120, and the cathode lead terminal 130 are prepared. There are no particular limitations on the manufacturing method of the capacitor element 110, and it can be manufactured by known methods. The anode lead terminal 120 and the cathode lead terminal 130 can be formed by known metalworking methods.

[0113] 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 cathode layer 117 and the cathode lead terminal 130 can be connected by, for example, the following method. First, a metal paste that will become 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 metal paste is hardened to become a conductive member 141. In this way, the cathode layer 117 and the cathode lead terminal 130 can be connected.

[0114] Next, the capacitor element is sealed with an outer resin 101 material (e.g., molding resin). The sealing process can be carried out by known methods. In this way, the electrolytic capacitor 100 can be manufactured. Other electrolytic capacitors of this disclosure can also be manufactured by similar manufacturing methods. [Industrial applicability]

[0115] This disclosure can be used in electrolytic capacitors where high reliability is required. [Explanation of Symbols]

[0116] 100:Electrolytic コンデンサ 100b: Bottom surface 100t: Above 101: Outer Resin 110:Kondor Motoko 112:Anode リード 120:Anode リード terminal 121: Anode terminal section 121a: First Domain 121b: Second Domain 121e, 131e: End of the body 121S, 131S: Main face 123, 133:アンカーBU 124, 134, 154: Domain 124S, 134S, 154S: Inclined surface 123a, 133a, 153a: Standing section 123b, 133b: Extended in the department 125: Protrusion 125d: Tip face 130:Cathode リード terminal 131: Cathode terminal section 131e: End 133a: Standing section 133b: Extended in the Ministry S1: 1st main surface S2: Second Main Face S3, S4: Side view D1, D2: Direction

Claims

1. An electrolytic capacitor having a bottom surface and an upper surface opposite to the bottom surface, A capacitor element including an anode lead, The capacitor element is electrically connected to an anode lead terminal and a cathode lead terminal, The capacitor element includes an outer resin arranged around it, 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 tip of the anode lead. The first main surface is exposed at the bottom surface, The anode terminal portion has a central first region and second A and second B regions on both sides of the first region. The anode connection portion rises from the first region toward the upper surface, The second A region and the second B region each extend from the first region and include a projection whose tip protrudes from the edge of the bottom surface. The protrusions in the second A region and the protrusions in the second B region each have sides that are connected to the first main surface and the second main surface, An electrolytic capacitor in which the side surface of the protrusion in the second A region and the side surface of the protrusion in the second B region face each other and are inclined in different directions with respect 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 the second A region and the side surface of the protrusion in the second B region are each inclined to form an obtuse angle with respect to the first main surface.

3. The electrolytic capacitor according to claim 2, wherein the inclination angles of the side surface of the protrusion in the second A region and the side surface of the protrusion in the second B region with respect to the first main surface are 100° or more and 135° or less.

4. In the anode lead terminal, two anchor portions extend from the second A region and the second B region, respectively, and are embedded in the outer resin. The second A region and the second B region each have an edge along the longitudinal direction of the anode lead, The electrolytic capacitor according to any one of claims 1 to 3, wherein each of the two anchor portions includes an upright portion rising from the end edge toward the upper surface and an extended portion bending and extending from the upper end of the upright portion.

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

6. The electrolytic capacitor according to claim 4 or 5, wherein the extended portion of one of the two anchor portions and the extended portion of the other of the two anchor portions extend in a direction away from each other.

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