TW201409508A - Solid electrolytic capacitor - Google Patents

Abstract

The present invention provides a solid electrolytic capacitor capable of solving the problem of complicated manufacturing steps, increasing electrostatic capacitance, and restraining the increase of leading resistance. The solid electrolytic capacitor of the present invention comprises: a rectangular element which is formed by flatting the winding element made by rolling up an anode foil, a cathode foil and a separation sheet between the anode foil and the cathode foil to thereby constitute a solid electrolyte; an anode leading terminal; a cathode leading terminal; a packaging body which packages the rectangular element; and a lead frame which is exposed out of the packaging body. Furthermore, the anode leading terminal and the cathode leading terminal are disposed at one side in relation to the roll core of the rectangular element; a second board part is more far from the roll core in comparison to a first board part; a first exposure part is thicker than the first board part and protrudes towards the side of the roll core; a second exposure part is thicker than the second board part and the first board part, and protrudes towards the roll core; and the protrudent height of the second exposure part from the second board part is higher than the protrudent height of the first exposure part from the first board part.

Description

Solid electrolytic capacitor

The present invention relates to a solid electrolytic capacitor.

In recent years, with the high performance and miniaturization of electronic equipment, molded chip parts in consideration of the mounting density of parts have become mainstream. Aluminum electrolytic capacitors are no exception, and surface mount technology (SMT) aluminum electrolytic capacitors are also widely used.

Surface mount technology is a new generation of electronic assembly technology that compresses traditional electronic components to a fraction of the previous volume, enabling high density, high reliability, miniaturization, low cost, and production automation for electronic component mounting. However, in the case of aluminum electrolytic capacitors, the usual surface mounts are vertical (collectively referred to as V-wafers), and there are limitations in electronic devices that require low back.

As a technique for overcoming the above disadvantages, a wound type molded wafer using polyaniline in a solid electrolyte layer has been proposed. However, in order to mold the cylindrical wound element, there is a constraint in the diameter of the wound element, and the package still occupies a relatively large thickness space, making it difficult to meet the problem of lower back requirements. Moreover, as a second problem, there is a molded wafer type solid electrolytic capacitor in which an element can be formed into a thin laminated structure, however, when a polypyrrole as a solid electrolyte layer is formed, a chemical polymerization film is formed in the first layer, so that The second layer is electrolytically polymerized. In this method, electrolytic polymerization takes a long time, and the electrolytic polymerization must be treated in a single layer and welded in an amount corresponding to the number of laminated sheets, which causes a problem of labor.

In view of the above problems, a solid electrolytic capacitor including a rectangular parallelepiped element which is wound by an anode foil, a cathode foil, and a separator interposed between the anode foil and the cathode foil is proposed, and is flattened into a rectangular parallelepiped and borrowed. A solid electrolyte is formed by chemical polymerization; an electrode lead terminal is connected to the element; and a package encapsulating the cuboid element (for example, refer to Patent Document 1).

Fig. 12 (a) is a schematic view showing a conventional solid electrolytic capacitor, and (b) is a schematic view of a rectangular parallelepiped member included in the solid electrolytic capacitor shown in (a).

The solid electrolytic capacitor 101 includes a rectangular parallelepiped element 110 which is wound by an anode foil, a cathode foil, and a separator interposed between the anode foil and the cathode foil, and is further flattened into a rectangular parallelepiped to form a solid electrolyte; an anode lead terminal 121 and a cathode A terminal 122 is connected to the component 110; and a package 130 encapsulating the component 110 of the rectangular parallelepiped. The anode lead terminal 121 is exposed from one end surface 110a of the element 110 and is connected to the lead frame 140. The cathode lead terminal 122 is exposed from the other end surface 110b of the element 110 and is connected to the lead frame 140.

According to the solid electrolytic capacitor described in Patent Document 1, the lower back requirement can be satisfied, and the increase in man-hour can be suppressed. Further, since it is unnecessary to use a noble metal such as silver or tantalum as compared with the conventional tantalum capacitor, cost reduction can be achieved.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Patent Application Publication No. 101527203 of the People's Republic of China

However, in the solid electrolytic capacitor described in Patent Document 1, as shown in FIGS. 12(a) and (b), the anode lead terminal 121 connected to the anode foil and the cathode lead terminal 122 connected to the cathode foil are wound core 110c. Since the (single-point chain line) is disposed on both sides (symmetric) as the center, the position (height) of the anode lead-out terminal 121 and the position (height) of the cathode lead-out terminal 122 are largely different in the thickness direction of the element 110. . However, in the solid electrolytic capacitor 101, when the package body 130 is formed by the resin sealing member 110, it is necessary to make the heights of the lead frames 140 exposed from the package 130 uniform. Therefore, in the solid electrolytic capacitor described in Patent Document 1, the step 140a is provided by bending the lead frame 140, and the height of the lead frame 140 must be adjusted at the connection position between the lead frame 140 and the cathode lead terminal 122. There are problems in that the manufacturing steps are cumbersome.

Further, if the step 140a is provided on the lead frame 140, the step portion must also be sealed by the resin, so that it is necessary to shorten the width of the electrode foil (for example, the anode foil). Therefore, there is a problem that the electrostatic capacitance of the capacitor is limited.

In response to the above problems, the inventors have proposed a solid electrolytic capacitor as shown in FIG.

Fig. 13 (a) is a schematic view showing an example of a solid electrolytic capacitor proposed by the inventors of the present invention, and (b) is a schematic view showing a rectangular parallelepiped element included in the solid electrolytic capacitor shown in (a). In addition, in FIG. 13, the same code|symbol as FIG.

In the solid electrolytic capacitor 101' shown in Fig. 13, and the solid shown in Fig. The bulk electrolytic capacitor 101 differs in that both the anode lead terminal 121 and the cathode lead terminal 122 are disposed on one side (lower side in the drawing) with respect to the winding core 110c of the element 110. Therefore, the height difference between the anode lead terminal 121 and the cathode lead terminal 122 can be reduced without providing the step 140a on the lead frame 140 (FIG. 12). As a result, the bending process of the lead frame 140 can be omitted, so that the cumbersome manufacturing steps can be solved. Moreover, since the step 140a (Fig. 12) of the lead frame 140 can be eliminated, the width (area) of the electrode foil can be enlarged. Therefore, the capacitance value of the capacitor can be increased.

Further, the inventors have found that when both the anode lead terminal 121 and the cathode lead terminal 122 are disposed on one side with respect to the winding core 110c of the element 110 as shown in FIG. 13, the resistance value of the solid electrolytic capacitor 101' is generated. Increased new problems. This problem will be described below.

Fig. 14 is a view showing the positional relationship between the anode foil 111 and the anode lead terminal 121 and the positional relationship between the cathode foil 112 and the cathode lead terminal 122 in the solid electrolytic capacitor 101' shown in Fig. 13.

The solid electrolytic capacitor 101' (Fig. 13) is obtained by winding the anode foil 111, the cathode foil 112, and a separator (not shown). One end 111a in the longitudinal direction of the anode foil 111 and one end 112a in the longitudinal direction of the cathode foil 112 are the end portions on the winding core 110c side of the element 110'. On the other hand, the other end 111b of the anode foil 111 and the other end 112b of the cathode foil 112 are located at the end portion on the outer peripheral side of the element 110'.

As shown in FIG. 13, when both the anode lead terminal 121 and the cathode lead terminal 122 are disposed on one side with respect to the winding core 110c of the element 110, the anode lead terminal 121 is disposed substantially in the longitudinal direction of the anode foil 111. The cathode lead terminal 122 is disposed in the vicinity of the core side end portion 112a of the cathode foil 112.

Thereby, the cathode lead terminal 122 is disposed in the vicinity of the core side end portion 112a of the cathode foil 112, and is far away from the center of the cathode foil 112 in the longitudinal direction. As a result, there is a problem that the resistance value (so-called extraction resistance) increases in the solid electrolytic capacitor 101' shown in FIG.

The present invention has been made in view of the above problems, and an object thereof is to provide a solid electrolytic capacitor which can solve the cumbersome manufacturing steps, increase the electrostatic capacitance, and can suppress an increase in the extraction resistance.

The present invention relates to a solid electrolytic capacitor comprising: a rectangular parallelepiped element which flattens a wound element obtained by winding an anode foil, a cathode foil, and a separator interposed between an anode foil and a cathode foil into a rectangular parallelepiped Forming a solid electrolyte; an anode lead terminal including a first plate-shaped portion connected to the anode foil in the rectangular parallelepiped element; and a first exposed portion exposed from one end surface of the rectangular parallelepiped element; and a cathode lead terminal including a second plate-shaped portion connected to the cathode foil in the rectangular parallelepiped element; and a second exposed portion exposed from the other end surface of the rectangular parallelepiped element; a package enclosing the rectangular parallelepiped element; and a lead frame soldered to the above Each of the first exposed portion and the second exposed portion is exposed from the package.

In the above solid electrolytic capacitor, both of the anode lead terminal and the cathode lead terminal are disposed on one side with respect to the winding core of the rectangular parallelepiped element.

In the above solid electrolytic capacitor, in the thickness direction of the rectangular parallelepiped element, the second plate-shaped portion is apart from the winding core than the first plate-shaped portion, and the first exposed portion is thicker than the first plate-shaped portion and is oriented to the roll The core side protrudes, the second exposed portion is thicker than the second plate portion and protrudes toward the winding core side beyond the first plate portion, and the height of the second exposed portion protruding from the second plate portion is higher than The height of the first exposed portion protruding from the first plate-like portion is high.

In the solid electrolytic capacitor of the present invention, both the anode lead terminal and the cathode lead terminal are disposed on one side with respect to the winding core of the rectangular parallelepiped element, and the second plate-shaped portion is away from the first plate-shaped portion in the thickness direction of the rectangular parallelepiped element. core. Therefore, in the present invention, it is not necessary to arrange the cathode lead terminal in the vicinity of the winding core side end portion of the cathode foil, and the cathode lead terminal can be disposed at a position (for example, substantially at the center) close to the center in the longitudinal direction of the cathode foil. Thereby, an increase in the extraction resistance can be suppressed.

Further, both the anode lead terminal and the cathode lead terminal are disposed on one side with respect to the winding core of the rectangular parallelepiped element, and the first exposed portion is thicker than the first plate-shaped portion and protrudes toward the winding core side in the thickness direction of the rectangular parallelepiped element. The second exposed portion is thicker than the second plate-shaped portion and protrudes toward the winding core side beyond the first plate-shaped portion, and the second exposed portion protrudes from the second plate-shaped portion at a height higher than the first exposed portion from the first plate-shaped portion. High height. Therefore, the step difference between the anode lead terminal and the cathode lead terminal can be reduced without bending the lead frame, so that the cumbersome manufacturing steps can be solved. Moreover, since the bending step of the lead frame can be eliminated, the width (area) of the electrode foil can be enlarged. Therefore, the capacitor can be made The capacitance value increases.

The above described objects, features and advantages of the present invention will become more apparent from the detailed description. In order to facilitate the understanding of the present invention, the details are described in the following description. However, the present invention may be carried out other than the embodiments described below, and is not limited to the following embodiments. Furthermore, the drawings are not to be considered in all respect Further, in the drawings, in order to emphasize the characteristic portions of the present invention, a part of the configuration may be omitted.

A solid electrolytic capacitor according to an embodiment of the present invention will be described.

1(a) is a schematic longitudinal cross-sectional view showing a solid electrolytic capacitor according to an embodiment of the present invention, and (b) is a view schematically showing a rectangular parallelepiped element included in the solid electrolytic capacitor shown in (a). (c) A longitudinal cross-sectional view of the rectangular parallelepiped element shown in (b).

2(a) is a view showing a positional relationship between an anode foil and an anode lead terminal in the solid electrolytic capacitor shown in FIG. 1, and a positional relationship between a cathode foil and a cathode lead terminal, and (b) is for explaining the present invention. A diagram of the distance D between the center of the cathode foil in the longitudinal direction and the second plate-like portion of the cathode lead terminal, and the length L of the cathode foil in the longitudinal direction.

Fig. 3(a) is a cross-sectional view schematically showing an anode foil, and Fig. 3(b) is a cross-sectional view schematically showing a cathode foil.

FIG. 4 is a schematic perspective view showing an exploded structure before solid electrolyte formation of the solid electrolytic capacitor according to the embodiment of the present invention.

As shown in FIG. 4, the solid electrolytic capacitor 1 includes a rectangular parallelepiped element 10 which is a wound component obtained by winding an anode foil 11, a cathode foil 12, and a separator 13 disposed between the anode foil 11 and the cathode foil 12. Flattened into a rectangular parallelepiped to form a solid electrolyte; an anode lead terminal 21 connected to the anode foil 11; a cathode lead terminal 22 connected to the cathode foil 12; and a package body 30 (refer to FIG. 1) which is molded by a resin to a rectangular parallelepiped Element 10 is packaged.

In Fig. 4, the end portion of the sealing tape 14 is free, but actually, the end portion of the sealing tape 14 is attached to the side of the rectangular parallelepiped member 10. Further, there is also a method of attaching with an adhesive without using a sealing tape. As shown in FIG. 4, the anode foil 11 and the cathode foil 12 have a strip shape as a whole. A separator 13 is provided between the anode foil 11 and the cathode foil 12. As the solid electrolyte held by the surface of each of the anode foil and the cathode foil and the separator 13, a conductive polymer is used. Examples of the conductive polymer include poly(3,4-ethylenedioxythiophene).

As shown in FIG. 3(a), the anode foil 11 includes a first valve metal layer 15 and a dielectric oxide film 16 formed on the surface of the first valve metal layer 15. Examples of the valve metal herein include metals such as aluminum, ruthenium, iridium, and titanium. Aluminum is used in the present embodiment. The dielectric oxide film 16 is formed on the surface of the etched first valve metal layer 15 by a chemical conversion treatment. In the present embodiment, the dielectric oxide film is alumina.

As shown in FIG. 3(b), the cathode foil 12 includes a second valve metal layer 17 and a carbide particle layer 18 attached to the surface of the second valve metal layer 17. Examples of the valve metal herein include metals such as aluminum, ruthenium, iridium, and titanium. Aluminum is used in the present embodiment. In addition, in FIGS. 3(a) and 3(b), the anode foil 11 and the cathode foil are shown. Although the laminated structure in the foil of each of 12 is shown in FIG. 3, the laminated structure in each electrode foil is not shown. Further, as shown in FIG. 2, the foil length of the cathode foil 12 (the length of the cathode foil 12 in the longitudinal direction) is longer than the foil length of the anode foil 11 (the length of the anode foil 11 in the longitudinal direction), and as described below, the cathode foil 12 is wound around the outer side of the winding shaft with respect to the anode foil 11.

As shown in FIG. 1, the solid electrolytic capacitor 1 includes an anode lead terminal 21 and a cathode lead terminal 22. The anode lead terminal 21 is connected to the anode foil 11 (refer to FIG. 4). The cathode lead terminal 22 is connected to the cathode foil 12 (refer to FIG. 4).

As shown in FIG. 1, the anode lead terminal 21 includes a first plate-like portion 21b that is connected to the anode foil 11 in the rectangular parallelepiped element 10, and a first exposed portion 21a that is exposed from one end surface 10a of the rectangular parallelepiped element 10. The cathode lead terminal 22 includes a second plate portion 22b that is connected to the cathode foil 12 in the rectangular parallelepiped element 10, and a second exposed portion 22a that is exposed from the other end surface 10b of the rectangular parallelepiped element 10. The end faces 10a and 10b are faces perpendicular to the winding axis (the winding core 10c) of the anode foil 11 and the cathode foil 12 of the rectangular parallelepiped member 10. In other words, it is a surface perpendicular to the width direction of the anode foil 11 and the cathode foil 12. Further, a surface of the rectangular parallelepiped element 10 that is parallel to the winding axis of the anode foil 11 and the cathode foil 12 is a side surface of the rectangular parallelepiped element 10. Further, the winding core 10c includes the spacer 13 located at the innermost circumference, and is subjected to press working on the winding member 19 (Fig. 6), as viewed in the axial direction of the winding core 10c as shown in Fig. 1(c). It extends in the longitudinal direction of the end face 10b.

The first exposed portion 21a of the anode lead terminal 21 and the second exposed portion 22a of the cathode lead terminal 22 include a non-valve metal. The first plate-like portion 21b of the anode lead-out terminal and the second plate-like portion 22b of the cathode lead-out terminal include a valve metal. In addition, the first exposed portion 21a and the cathode lead-out terminal 22 of the anode lead terminal 21 The second exposed portion 22a may also include a valve metal. Both the anode lead terminal 21 and the cathode lead terminal 22 are disposed on one side with respect to the winding core 10c of the rectangular parallelepiped element 10. Thereby, the height difference between the anode lead terminal 21 and the cathode lead terminal 22 outside the rectangular parallelepiped element 10 can be reduced.

Further, in the thickness direction of the rectangular parallelepiped element 10, the second plate-like portion 22b of the cathode lead-out terminal 22 is away from the winding core 10c than the first plate-like portion 21b of the anode lead-out terminal 21. For example, a solid electrolyte layer (a piece of separator 13) and a cathode foil 12 (one piece of cathode foil 12) are disposed between the second plate-like portion 22b and the first plate-like portion 21b. Further, a solid electrolyte layer (a piece of separator 13) and an anode foil 11 (one anode foil 11) may be disposed between the second plate-like portion 22b and the first plate-like portion 21b, or only a solid electrolyte layer may be disposed (a piece of separator) Slice 13). Thereby, the second plate-like portion 22b and the first plate-like portion 21b are disposed at intervals in the thickness direction of the rectangular parallelepiped element 10, and are insulated without being in direct contact.

Further, as shown in FIGS. 1(a) and 1(b), at least a part of the second plate-like portion 22b and the first plate-like portion 21b overlap in the thickness direction of the rectangular parallelepiped element 10. The second plate-like portion 22b may overlap with at least half of the first plate-like portion 21b, or the second plate-like portion 22b may overlap with two-thirds or more of the first plate-like portion 21b. Further, in the present embodiment, the two terminals have the same width. However, when the widths of the two terminals are different, the degree of overlap between the two terminals is calculated based on the terminal having a short width. Further, the winding core 10c overlaps the second plate-like portion 22b and the first plate-like portion 21b in the thickness direction of the rectangular parallelepiped element 10. The width of the first plate-like portion 21b and the second plate-like portion 22b is narrower than the width of the winding core 10c in the longitudinal direction of the end surface 10b (or the end surface 10a).

The first exposed portion 21a is thicker than the first plate-like portion 21b and protrudes toward the winding core 10c side. Further, in the present embodiment, the first exposed portion 21a also protrudes to the opposite side of the winding core 10c. Further, the second exposed portion 22a is thicker than the second plate-like portion 22b and protrudes beyond the first plate-like portion 21b toward the winding core 10c side. Second exposed portion 22a of the second plate portion 22b protruding height H ₂ than the first exposed portion 21b from 21a projecting height H of the first plate-shaped portion from _a high. First exposed portion 21a of the first plate-like portion 21b thicker than the winding core 10c and the protruding side, and therefore is not H ₁ 0. In the present embodiment, as shown in Fig. 1(a), the surface 21c of the first exposed portion 21a on the winding core 10c side (upper side in the drawing) and the winding core 10c side of the second exposed portion 22a (upper side in the drawing) The surface 22c is substantially in the same plane. In other words, the surface 21c and the surface 22c are substantially at the same height in the thickness direction (up and down direction in the drawing) of the rectangular parallelepiped element 10. The lead frame 40 is soldered to each of the surfaces 21c, 22c. Since the surface 21c and the surface 22c are substantially at the same height, the welding of the surfaces 21c, 22c and the lead frame 40 can be performed without providing a step (see FIG. 12) in the lead frame 40. In the present embodiment, the lead frame 40 located in the package 30 has a flat shape. That is, the lead frame 40 located in the package 30 is not subjected to bending processing.

As shown in FIG. 1(a), a lead frame 40 is provided outside the rectangular parallelepiped element 10. The lead frame 40 is embedded in the package body 30. Further, a first exposed portion 21a of the anode lead terminal 21 or a second exposed portion 22a of the cathode lead terminal 22 is connected to each lead frame 40. In this configuration, when the solid electrolytic capacitor 1 is manufactured, a plurality of rectangular parallelepiped elements 10 are connected to one lead frame 40 (see FIGS. 9 and 11).

The lead frame 40 exposed from the inside of the package 30 is bent toward the lower side of FIG. 1 along the surface of the package 30. Moreover, the anode lead terminal 21 and the cathode lead terminal 22 is closer to the lower side of FIG. 1 than the core 10c. That is, the anode lead terminal 21 and the cathode lead terminal 22 are located on one side with respect to the winding core 10c, and the lead frame 40 is bent toward the same side.

In the present embodiment, the first exposed portion 21a and the second exposed portion 22a are flat. When the first exposed portion 21a and the second exposed portion 22a are connected to the lead wires outside the rectangular parallelepiped element 10 (for example, the lead frame 40) as compared with the case where the portion is cylindrical, a larger contact can be obtained. Area to ensure electrical connection. In the present invention, the first exposed portion 21a and the second exposed portion 22a may be thicker than the first plate portion 21b and the second plate portion 22b, and the shapes of the first exposed portion 21a and the second exposed portion 22a are not In this example, for example, a plate shape thicker than the first plate-shaped portion 21b and the second plate-like portion 22b may be used. The surface 21c of the first exposed portion 21a and the surface 22c of the second exposed portion 22a may be flat, curved, or may include a flat surface and a curved surface.

As shown in FIG. 1, the rectangular parallelepiped element 10 and the lead frame 40 connected to the rectangular parallelepiped element 10 are encapsulated (sealed) by the package 30, thereby ensuring insulation from the outside. Examples of the package 30 include an epoxy resin, a liquid crystal polymer, and the like. Moreover, a usual molding process is used when the package body 30 is formed. In the package 30, the lead frame 40 has a flat plate shape and is in surface contact with each of the anode lead terminal 21 and the cathode lead terminal 22. In the package 30, the lead frame 40 is not subjected to bending processing. Specifically, between the end faces 10a and 10b of the rectangular parallelepiped member 10 and the surface of the package body 30 opposed to the end faces 10a and 10b, the lead frame 40 is not subjected to bending processing, and the lead frame 40 is parallel to the axis of the winding core 10c ( The single-dot chain line in Fig. 1 extends in the direction. Therefore, the end faces 10a, 10b of the rectangular parallelepiped member 10 and the seals facing the end faces 10a, 10b can be shortened. The distance between the surfaces of the body 30. As a result, the width of the anode foil 11 can be enlarged, so that the electrostatic capacitance can be increased.

In the present embodiment, by setting the rectangular parallelepiped element 10 to an appropriate thickness (for example, 1.8 mm), it is not restricted by the thickness of the rectangular parallelepiped element during resin molding, and a wafer type solid electrolytic capacitor capable of coping with lower back requirements can be realized. . Therefore, according to the solid electrolytic capacitor 1 of the present embodiment, the space occupied by the thickness is small, and the requirement for low-profile of the electronic device can be satisfied at a higher level.

Further, in the present embodiment, when the anode foil 11 and the cathode foil 12 are not wound, the anode lead terminal 21 is attached to a position overlapping the center C _{1 of the} anode foil 11 in the longitudinal direction. Further, the cathode lead terminal 22 is attached to a position overlapping the center C _{2 of the} cathode foil 12 in the longitudinal direction. Thereby, an increase in the extraction resistance can be suppressed. As a result, an increase in the resistance value of the solid electrolytic capacitor 1 can be suppressed. Further, the attachment of the electrode lead terminals 21 and 22 to the respective electrode foils 11 and 12 is performed, for example, by caulking.

Accordingly, in the present invention, preferably as shown in FIG 2 (a), each electrode lead terminals 21, 22 disposed in the center of the longitudinal direction of each of the electrode foils 11 and 12 C _1, C ₂ nearby. In the present invention, as shown in FIG. 1, the second plate-like portion 22b of the cathode lead terminal 22 is disposed in the thickness direction of the rectangular parallelepiped member 10 than the first plate-like portion 21b of the anode lead-out terminal 21. Since it is away from the position of the winding core 10c, as shown in Fig. 2 (a), the cathode lead terminal 22 can be disposed in the vicinity of the center C _{2 in} the longitudinal direction of the cathode foil 12.

Specifically, as shown in FIG. 2(b), in the case where the cathode foil 12 is not wound, the center C _{2 of the} cathode foil 12 in the longitudinal direction and the second plate-like portion 22b of the cathode lead terminal 22 (foil length direction) The distance D between the center of the upper second plate portion 22b and the length L of the cathode foil 12 in the longitudinal direction preferably satisfy the relationship of 0 ≦ D / L ≦ 0.15. Further, D/L = 0 means that the second plate-like portion 22b is disposed so as to be in contact with or overlap with the center C _{2 of the} cathode foil 12 in the longitudinal direction. The increase in the extraction resistance can be effectively suppressed by satisfying the relationship of 0 ≦ D / L ≦ 0.15. Further, in the present invention, as shown in FIG. 2(a), the cathode lead terminal 22 is preferably disposed so as to overlap the center C _{2 of the} cathode foil 12 in the longitudinal direction. Further, it is preferable that the cathode lead terminal 22 is disposed such that the center of the cathode lead terminal 22 in the width direction substantially coincides with the center C _{2 of the} cathode foil 12 in the longitudinal direction. The increase in the extraction resistance can be more effectively suppressed. The anode foil 11 and the anode lead terminal 21 are also the same.

Next, a method of manufacturing the solid electrolytic capacitor in the present embodiment will be described with reference to Figs. 5 to 11 .

<Step S1>

As shown in Fig. 5, the anode foil 11 and the cathode foil 12 which are cut into a specific width are prepared. Specifically, both the anode foil 11 and the cathode foil 12 are strip-shaped. Since the anode foil 11 and the cathode foil 12 are as described above, the description thereof is omitted here.

<Step S2>

As shown in FIG. 5, each of the electrode lead terminals 21 and 22 is bonded to the anode foil 11 and the cathode foil 12.

Specifically, a step of bonding the anode lead terminal 21 to the anode foil 11 (first bonding step) and a step of bonding the cathode lead terminal 22 to the cathode foil 12 (second bonding step) are performed. Further, the order of the first joining step and the second joining step (sequential) is not particularly limited.

The anode lead terminal 21 includes a first plate-like portion 21b, a first exposed portion 21a, and a first columnar portion 21e in the manufacturing process.

The first plate portion 21b is located at one end of the anode lead terminal 21. The first plate portion 21b is overlapped with the anode foil 11 and bonded to the anode foil 11.

The first exposed portion 21a is continuous with the first plate portion 21b. As shown in FIG. 5, when the first plate-like portion 21b is joined to the anode foil 11, the first exposed portion 21a is more than one side (the lower side in the drawing) in the longitudinal direction (the horizontal direction in the drawing) of the anode foil 11. The outer side (lower side in the drawing) of the anode foil 11 protrudes in the short side direction (lower side in the drawing), and does not overlap the anode foil 11.

The first columnar portion 21e is a portion extending from the opposite side (lower side in the drawing) of the first exposed portion 21a from the continuous side (upper side in the drawing) of the first plate-like portion 21b. Therefore, when the first plate-like portion 21b is joined to the anode foil 11, the first exposed portion 21a and the first columnar portion 21e protrude from one side (the lower side in the drawing) of the anode foil 11 in the longitudinal direction.

The cathode lead terminal 22 includes a second exposed portion 22a, a second plate portion 22b, a connecting portion 22d, and a second columnar portion 22e in the manufacturing process.

The second exposed portion 22a is located at one end of the cathode lead terminal 22. As shown in FIG. 5, when the second plate-like portion 22b is joined to the cathode foil 12, the second exposed portion 22a is more oriented than one side (the upper side in the drawing) in the longitudinal direction (the horizontal direction in the drawing) of the cathode foil 12. The outer side (upper side in the drawing) of the cathode foil 12 in the short-side direction (up-and-down direction in the drawing) protrudes and does not overlap with the cathode foil 12.

The second plate portion 22b is continuous with the second exposed portion 22a. The second plate portion 22b is overlapped with the cathode foil 12 and bonded to the cathode foil 12.

The connecting portion 22d is continuous with the second plate portion 22b. As shown in Figure 5, when the second When the plate-like portion 22b is joined to the cathode foil 12, the connecting portion 22d is more toward the short side of the cathode foil 12 than the other side (the lower side in the drawing) in the longitudinal direction (the horizontal direction in the drawing) of the anode foil 11 (Fig. The outer side (lower side in the middle) of the middle and lower direction protrudes and does not overlap with the cathode foil 12.

The second columnar portion 22e is continuous with the connecting portion 22d. That is, the connecting portion 22d and the second columnar portion 22e are when the second plate-like portion 22b is joined to the cathode foil 12, and the other side of the length of the cathode foil 12 is exceeded from the second plate-like portion 22b (lower in the figure) The side of the side) extends toward the outer side (the lower side in the drawing) of the short side direction of the cathode foil 12.

In step S2, the second plate-like portion 22b is joined to the cathode foil 12, and the other side (the lower side in the drawing) from the second plate-like portion 22b beyond the longitudinal direction of the cathode foil 12 is cut away to the cathode foil. A portion (the connecting portion 22d and the second column portion 22e) extending from the outer side (the lower side in the drawing) of the short side direction of 12 (second cutting step). In the present embodiment, the distance between the anode lead terminal 21 and the cathode lead terminal 22 in the thickness direction of the rectangular parallelepiped element 10 is short, and the first exposed portion 21a of the anode lead terminal 21 is thicker than the first plate portion 21b, so The short circuit between the anode lead terminal 21 and the cathode lead terminal 22 is prevented, and the connection portion 22d of the cathode lead terminal 22 needs to be carefully removed. Therefore, as shown in FIG. 1, in the rectangular parallelepiped element 10, the cathode lead terminal 22 protrudes from the end surface 10b of the rectangular parallelepiped element 10, but does not substantially protrude from the end surface 10a of the rectangular parallelepiped element 10. In the present invention, it is preferable that the cathode lead terminal 22 (second plate portion 22b) does not protrude from the end surface 10a of the rectangular parallelepiped member 10. However, from the viewpoint of preventing a short circuit, it is allowed to protrude a small amount (for example, an unavoidable error at the time of manufacture). In addition, the joining of the electrode lead terminals 21, 22 and the electrode foils 11, 12 is performed by riveting Conducted by ultrasonic welding or the like.

<Step S3>

As shown in FIG. 6, the anode foil 11 and the cathode foil 12, and the separator 13 disposed between the anode foil 11 and the cathode foil 12 are wound and cut to a specific length to form a cylinder, and the sealing tape 14 is formed. Fix the end to the side of the cylinder. Here, the cathode foil 12 is wound around the outer side of the winding shaft with respect to the anode foil 11, and the cathode foil 12 is located at the outermost circumference of the cylinder. According to this configuration, ESR (Equivalent Series Resistance, equivalent) can be obtained by covering the dielectric oxide film 16 formed on the anode foil 11 with the cathode foil having a low electric resistance (the cathode foil 12 is brought close to the dielectric oxide film 16). The series resistance) drops. Further, since the cathode foil 12 is softer than the anode foil 11, the stress of the molding resin against the element can be alleviated by winding the cathode foil 12 around the anode foil 11. Further, as a method of fixing the end portion to the side surface of the cylindrical body, in addition to the method of fixing the end portion to the side surface of the cylindrical body using the sealing tape 14, for example, it is also attached by an adhesive without using a sealing tape. method. Thereby the winding element 19 is formed. At this time, the first plate-like portion 21b of the anode lead terminal 21 and the second plate-like portion 22b of the cathode lead-out terminal 22 are located inside the wound element 19. Further, the first exposed portion 21a and the first columnar portion 21e of the anode lead terminal 21 are exposed from one end of the wound element 19. Further, the second exposed portion 22a of the cathode lead terminal 22 is exposed from the other end of the wound element 19. The separator 13 contains, for example, natural fibers (cellulose) or chemical fibers. The natural fiber or chemical fiber which can be used as the separator 13 is not particularly limited. As the chemical fiber, a synthetic fiber such as a polyamide fiber, an acrylic fiber, a vinylon fiber, a polyimide fiber, or a nylon fiber can be used.

<Step S4>

As shown in FIG. 7, the winding element 19 is deformed into a rectangular parallelepiped element 10. Specifically, the winding element 19 is fixed to a specific jig (not shown), and a load is applied to deform it, thereby forming a rectangular parallelepiped element 10 having a specific size. Next, the rectangular parallelepiped element 10 is fixed to the rod. Further, in the present embodiment, when the first exposed portion 21a has a columnar shape, the cylindrical first exposed portion 21a of the anode lead terminal 21 is pressed and formed into a flat shape.

<Step S5>

The rectangular parallelepiped element 10 is subjected to a chemical conversion treatment and a heat treatment. Specifically, the rectangular parallelepiped element 11 is immersed in a chemical conversion liquid in a chemical conversion container, and the chemical conversion container is used as a cathode, and the anode lead terminal 21 is an anode, and the anode foil 11 is chemically treated. The solute used in the chemical conversion liquid is a solute such as an organic acid salt containing a carboxylic acid group or an inorganic acid salt such as a phosphate. In the present embodiment, ammonium adipate is used as a chemical conversion liquid. This chemical conversion treatment uses a chemical conversion liquid mainly composed of an ammonium adipate concentration of 0.5 wt% to 3 wt%, and is carried out at a voltage close to the withstand voltage of the dielectric oxide film. Next, the rectangular parallelepiped element 10 is taken out from the chemical conversion liquid and heat-treated. The heat treatment is carried out in a temperature range of 200 ° C to 300 ° C for several minutes to several tens of minutes. Repeat the process of chemical conversion and heat treatment. By these processes, an oxide film is formed on the metal exposed on the valve metal exposed in the cross section of the anode foil 11 or the damage due to the connection of the terminals. Thereby, a dielectric oxide film having more excellent heat resistance can be formed.

<Step S6>

Forming a solid between the anode foil 11 and the cathode foil 12 of the above-described rectangular parallelepiped element Electrolyte layer 13. In the present embodiment, the solid electrolyte is a conductive polymer and is formed by chemical polymerization of 3,4-ethylenedioxythiophene as a monomer and iron p-toluenesulfonate as an oxidizing agent. Specifically, first, the monomer solution is diluted, for example, with ethanol to have a concentration of 25 wt%. The rectangular parallelepiped element 10 is immersed in a monomer solution, and then ethanol as a solvent is removed by heating and drying, and only the monomer remains. The temperature for heating and drying is preferably from 40 ° C to 60 ° C, for example, 50 ° C. When the temperature exceeds 60 ° C, the boiling point of ethanol is approached to cause rapid evaporation, and the monomer does not uniformly remain inside the rectangular parallelepiped element 10. Further, if it is 40 ° C or less, evaporation takes time. Although the drying time depends on the volume of the rectangular parallelepiped element 10, it is preferably about 10 minutes to 20 minutes in the rectangular parallelepiped element 10. Next, the oxidizing agent is impregnated into the rectangular parallelepiped element 10 in which the monomer remains to form 3,4-ethylenedioxythiophene. The impregnation of the above oxidizing agent is impregnated into the rectangular parallelepiped element 10 by a reduced pressure impregnation method. As a oxidizing agent, a 55 wt% butanol solution of p-toluenesulfonic acid iron salt was used, and the rectangular parallelepiped element 10 was immersed and impregnated with an oxidizing agent under reduced pressure. Next, the rectangular parallelepiped element 10 is heated stepwise from 30 ° C to 180 ° C to form poly(3,4-ethylenedioxythiophene) as a conductive polymer by chemical polymerization. Further, the conductive polymer formed in the rectangular parallelepiped element can be formed not only by chemical polymerization in a rectangular parallelepiped element, but also by synthesizing a conductive polymer in advance and dispersing it in a solvent, and immersing the rectangular parallelepiped element in the obtained product. The solution is formed by drying and dried, and a well-known conductive polymer such as polyaniline, polypyrrole or polythiophene may be used alone or in combination instead of poly(3,4-ethylenedioxythiophene). Further, in the present embodiment, the thickness of the first exposed portion 21a in the rectangular parallelepiped member 10 is The direction protrudes toward the winding core side and protrudes to the opposite side of the winding core side. Therefore, when the rectangular parallelepiped element 10 is impregnated for forming a solid electrolyte, it is possible to suppress the monomer, the oxidizing agent, and the like from spreading to the first exposed portion 21a.

<Step S7>

As shown in FIG. 8, the first exposed portion 21a of the anode lead terminal 21 is left, and a portion extending from the side opposite to the side of the first exposed portion 21a on the continuous side of the first plate-like portion 21b is cut out (the first columnar portion 21e) ) (first resection step).

Next, as shown in FIG. 9, each electrode lead terminal 21, 22 of the rectangular parallelepiped element 10 is connected to the lead frame 40. The lead frame 40 becomes an external lead terminal. As the connection method, for example, a method by laser welding or electric resistance welding or a method of connecting by silver paste or the like is used. In consideration of the manufacturing cost and the connection resistance, it is preferable to use a connection method of inter-metal bonding such as laser welding or electric resistance welding. In the conventional laminated solid electrolytic capacitor, after the solid electrolyte layer is formed on the anode foil, the silver paste is used, and the silver paste is used in the bonding of the coated rectangular parallelepiped element to the lead frame, thereby increasing the cost. One of the reasons for this is that in the present invention, since it can be joined by inter-metal bonding such as laser welding or electric resistance welding, a noble metal such as silver is not required, so that cost can be suppressed.

In addition, a specific connection method will be described using FIG.

As shown in FIG. 10(a), a needle (not shown) having a tapered tip is inserted through the lead frame 40 to form a projection 40a on the lead frame 40. The protruding portion 40a is formed along the circumference of the needle when the needle passes. The protruding portion 40a is formed to face the anode lead terminal 21 and the cathode lead terminal 22 when the anode lead terminal 21 is connected to the cathode lead terminal 22. The number of the protrusions 40a is not particularly limited. set. The thickness of the second exposed portion 22a is larger than the height of the protruding portion 40a from the surface of the lead frame 40. Further, the thickness of the first exposed portion 21a is larger than the height of the protruding portion 40a from the surface of the lead frame 40. Thereby, welding can be performed stably. Moreover, the welding strength can be increased or the welding resistance can be lowered.

Next, as shown in FIG. 10(b), the rectangular parallelepiped element 10 is placed on the lead frame 40 such that the anode lead terminal 21 and the cathode lead terminal 22 are in contact with the projection 40a of the lead frame 40.

Next, as shown in FIG. 10(c), the anode lead terminal 21 and the cathode lead terminal 22 are joined to the lead frame 40 by a method such as resistance welding. For example, when the anode lead terminal 21 and the cathode lead terminal 22 include aluminum and the lead frame 40 contains copper, the anode lead terminal 21 and the cathode lead terminal 22 are melted during soldering. When the difference in thickness between the anode lead terminal 21 and the cathode lead terminal 22 outside the rectangular parallelepiped element 10 is large, the difference in the degree of melting between the anode lead terminal 21 and the cathode lead terminal 22 becomes large, and it is difficult to accurately mold it. Hey. Therefore, it is preferable that the difference in thickness between the anode lead terminal 21 and the cathode lead terminal 22 outside the rectangular parallelepiped element 10 is as small as possible.

In the present embodiment, the height H _{2 of the} second exposed portion 22a protruding from the second plate-like portion 22b toward the winding core 10c side is higher than the height H of the first exposed portion 21a protruding from the first plate-like portion 21b toward the winding core 10c side. _{1 is} high, but the first exposed portion 21a also protrudes toward the opposite side of the winding core 10c. Thereby, the difference in thickness between the first exposed portion 21a and the second exposed portion 22a is reduced.

<Step S8>

As shown in FIG. 11 and FIG. 1, the package body 30 is formed by molding a rectangular parallelepiped element 10 connected to the lead frame 40, and then the lead frame 40 is formed. The terminal is completed while the wafer type solid electrolytic capacitor 1 is completed.

As described above, the method of manufacturing the solid electrolytic capacitor 10 of the present embodiment includes the first bonding step, the first etching step, the second bonding step, and the second cutting step, and the solid electrolytic capacitor 10 can be manufactured with high precision by a simple method. Further, since the second exposed portion 21a of the cathode lead terminal 22 is thicker than the second plate portion 21b, the positioning of the cathode lead terminal 22 with respect to the cathode foil 12 in the short side direction (width direction) of the cathode foil 12 becomes easy. . Further, since the second exposed portion 22a of the cathode lead terminal 22 is thicker than the second plate portion 22b, the surface 22c of the second exposed portion 22a is less likely to generate liquid during the formation of the solid electrolyte layer 13, and is formed at the second exposure. The thickness of the solid electrolyte on the surface 22c of the portion 22a becomes more uniform, so that the solid electrolyte of the surface 22c of the second exposed portion 22a is easily removed.

The above embodiments are preferred embodiments of the present invention, but are not intended to limit the present invention. The present invention can be variously modified or changed to the same embodiment using the above-described methods and technical contents within the scope of the present invention. Therefore, all changes, equivalents, and modifications of the embodiments of the present invention are also included in the scope of the present invention without departing from the scope of the invention.

<Example>

As an example, the solid electrolytic capacitor 1 (2.5 V, 220 μF) shown in the above embodiment (Fig. 1) was produced. The size of the package of the solid electrolytic capacitor 1 is 7.3 mm × 4.3 mm × 2.8 mm. As the lead frame 40, a copper frame material having a thickness of 100 μm whose surface was subjected to nickel plating treatment was used. Further, at the time of manufacture, the anode lead terminal 21 is bonded to the anode foil 11 such that the first plate-like portion 21b overlaps the center C1 of the anode foil 11 in the longitudinal direction, and the second plate portion 22b and the cathode foil 12 are bonded. The cathode lead terminal 22 is bonded to the cathode foil 12 in such a manner that the center C2 in the longitudinal direction overlaps. Further, before the lead frame 40 and the anode lead terminal 21 (aluminum anode plate) and the cathode lead terminal 22 (aluminum cathode plate) are connected, the needle is passed through the lead frame 40 and the anode lead terminal 21 and the cathode lead terminal 22. The connection position is thereby formed with the projection 40a at the above-described connection position. As a needle, use a tip with a quadrangular pyramid 0.26 mm needle. The height of the protrusion 40a is about 0.3 mm. The lead frame 40 is connected to the anode lead terminal 21 and the cathode lead terminal 22 by a variable frequency resistance welder.

<Comparative example>

A comparative example was carried out in the same manner as in the example except that the solid electrolytic capacitor 101 (2.5 V, 220 μF) shown in Fig. 13 was used instead of the solid electrolytic capacitor 1 in the example. The size of the package of the solid electrolytic capacitor 101 is 7.3 mm × 4.3 mm × 2.8 mm as in the embodiment.

The performance of the solid electrolytic capacitor 1 of the example and the solid electrolytic capacitor 101 of the comparative example was compared. The results are shown in Table 1. In addition, Tan δ represents the tangent of the loss angle. LC (Leakage Current) indicates leakage current. ESR represents the equivalent series resistance.

As shown in Table 1, compared with the solid electrolytic capacitor 101 of the comparative example, in the solid electrolytic capacitor 1 of the example, it was confirmed that the ESR was lowered, thereby The effectiveness of the invention is expressly embodied.

1‧‧‧Solid electrolytic capacitor

10‧‧‧Cuboidal components

10a, 10b‧‧‧ end face

10c‧‧‧core

11‧‧‧Anode foil

12‧‧‧Cathode foil

13‧‧‧Separator (solid electrolyte layer)

14‧‧‧Roll tape

15‧‧‧First valve metal layer

16‧‧‧Dielectric oxide film

17‧‧‧Second valve metal layer

18‧‧‧Carbide particle layer

19‧‧‧Winding components

21‧‧‧Anode lead terminal

21a‧‧‧First Exposed Department

21b‧‧‧ first plate

21c‧‧‧ surface

22‧‧‧Cathode lead terminals

22a‧‧‧Second exposure

22b‧‧‧Second plate

22c‧‧‧ surface

22d‧‧‧Connecting Department

22e‧‧‧Second column

30‧‧‧Package

40‧‧‧ lead frame

40a‧‧‧Protruding

101‧‧‧ solid electrolytic capacitor

101'‧‧‧ Solid electrolytic capacitor

110‧‧‧ components

110'‧‧‧ components

110c‧‧‧core

111‧‧‧Anode foil

111a‧‧‧End

111b‧‧‧The other end

112‧‧‧Cathode foil

112a‧‧‧End

112b‧‧‧The other end

121‧‧‧Anode lead terminal

122‧‧‧Cathode lead terminal

130‧‧‧Package

140‧‧‧ lead frame

140a‧‧ ‧ step

C ₁ ‧‧‧ Center

C ₂ ‧‧‧ Center

D‧‧‧Distance

H ₁ ‧‧‧ Height

H ₂ ‧‧‧ Height

L‧‧‧ length

1(a) is a schematic longitudinal cross-sectional view showing a solid electrolytic capacitor according to an embodiment of the present invention, and (b) is a view schematically showing a rectangular parallelepiped element included in the solid electrolytic capacitor shown in (a). (c) A longitudinal cross-sectional view of the rectangular parallelepiped element shown in (b).

2(a) is a view showing a positional relationship between an anode foil and an anode lead terminal in the solid electrolytic capacitor shown in FIG. 1, and a positional relationship between a cathode foil and a cathode lead terminal, and (b) is for explaining the present invention. A diagram of the distance D between the center of the cathode foil in the longitudinal direction and the second plate-like portion of the cathode lead terminal, and the length L of the cathode foil in the longitudinal direction.

Fig. 3(a) is a cross-sectional view schematically showing an anode foil, and Fig. 3(b) is a cross-sectional view schematically showing a cathode foil.

FIG. 4 is a schematic perspective view showing an exploded structure before solid electrolyte formation of the solid electrolytic capacitor according to the embodiment of the present invention.

Fig. 5 is a view schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Fig. 6 is a view schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Fig. 7 is a view schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Fig. 8 is a view schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Figure 9 is a view schematically showing a solid electrolytic capacitor according to an embodiment of the present invention Diagram of the manufacturing steps of the device.

10(a) to 10(c) are diagrams schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Fig. 11 is a view schematically showing a manufacturing procedure of a solid electrolytic capacitor according to an embodiment of the present invention.

Fig. 12 (a) is a schematic view of a conventional solid electrolytic capacitor, and (b) is a schematic view of a rectangular parallelepiped member included in the solid electrolytic capacitor shown in (a).

Fig. 13 (a) is a schematic view showing an example of a solid electrolytic capacitor proposed by the inventors of the present invention, and (b) is a schematic view showing a rectangular parallelepiped element included in the solid electrolytic capacitor shown in (a).

Fig. 14 is a view showing a positional relationship between an anode foil and an anode lead terminal in the solid electrolytic capacitor shown in Fig. 13 and a positional relationship between a cathode foil and a cathode lead terminal.

1‧‧‧Solid electrolytic capacitor

10‧‧‧Cuboidal components

10a, 10b‧‧‧ end face

10c‧‧‧core

21‧‧‧Anode lead terminal

21a‧‧‧First Exposed Department

21b‧‧‧ first plate

21c‧‧‧ surface

22‧‧‧Cathode lead terminals

22a‧‧‧Second exposure

22b‧‧‧Second plate

22c‧‧‧ surface

30‧‧‧Package

40‧‧‧ lead frame

H ₁ ‧‧‧ Height

H ₂ ‧‧‧ Height

Claims (6)

A solid electrolytic capacitor comprising: a rectangular parallelepiped element which flattens a wound element obtained by winding an anode foil, a cathode foil, and a separator interposed between an anode foil and a cathode foil into a rectangular parallelepiped to form a solid electrolyte; an anode lead terminal comprising: a first plate portion connected to the anode foil in the rectangular parallelepiped element; and a first exposed portion exposed from one end surface of the rectangular parallelepiped element; and a cathode lead terminal included in the rectangular parallelepiped a second plate-shaped portion connected to the cathode foil in the element; and a second exposed portion exposed from the other end surface of the rectangular parallelepiped element; a package enclosing the rectangular parallelepiped element; and a lead frame soldered to the first exposed portion Each of the second exposed portion and the second exposed portion is exposed from the package; and both the anode lead terminal and the cathode lead terminal are disposed on one side with respect to a winding core of the rectangular parallelepiped element; and in a thickness direction of the rectangular parallelepiped member The second plate-shaped portion is away from the winding core than the first plate-shaped portion, and the first exposed portion The first plate-shaped portion is thick and protrudes toward the winding core side, and the second exposed portion is thicker than the second plate-shaped portion and protrudes toward the winding core side beyond the first plate-shaped portion, and the second exposed portion is The height at which the second plate-like portion protrudes is higher than the height at which the first exposed portion protrudes from the first plate-like portion. The solid electrolytic capacitor of claim 1, wherein the lead frame and the second exposed portion are welded to each other a protrusion protruding toward the second exposed portion side; a thickness of the second exposed portion being larger than a height of the protrusion from a surface of the lead frame. The solid electrolytic capacitor according to claim 1 or 2, wherein, in the case where the cathode foil is not wound, a distance D between a center of a length direction of the cathode foil and the second plate portion of the cathode lead terminal, and the cathode The length L of the longitudinal direction of the foil satisfies the relationship of 0 ≦ D / L ≦ 0.15; wherein D / L = 0 means that the second plate-like portion is placed or overlaps with the center of the longitudinal direction of the cathode foil . The solid electrolytic capacitor according to claim 3, wherein the second plate-like portion is disposed to be in contact with or overlap with a center of the cathode foil in the longitudinal direction. The solid electrolytic capacitor according to any one of claims 1 to 4, wherein the first exposed portion protrudes toward the opposite side of the winding core in a thickness direction of the rectangular parallelepiped member. A method of manufacturing a solid electrolytic capacitor according to any one of claims 1 to 5, wherein the method comprises: a first bonding step of arranging the first plate-shaped portion at one end of the anode lead terminal The first plate-shaped portion of the anode lead terminal is bonded to the anode foil in a state in which the exposed portion protrudes toward the outer side in the short-side direction of the anode foil from one side in the longitudinal direction of the anode foil; a step of remaining after the first joining step a first exposed portion that cuts a portion extending from a side opposite to a side of the first exposed portion that is continuous with the first plate-shaped portion; and a second bonding step of the first end of the cathode lead-out terminal The second exposed portion is joined to the cathode foil in a state in which the second exposed portion protrudes outward in the short-side direction of the cathode foil from one side in the longitudinal direction of the cathode foil; and The cutting step is performed by cutting a portion extending from the other side of the second plate-shaped portion beyond the longitudinal direction of the cathode foil to the outside of the short side direction of the cathode foil after the second bonding step.