Solid electrolytic capacitor

Abstract

A solid electrolytic capacitor according to the present invention comprises: a capacitor element that has a positive electrode body that extends in a first direction and a negative electrode part that is formed on the surface of the positive electrode body with a dielectric layer therebetween; a first positive electrode terminal and a second positive electrode terminal that are electrically connected to respective ends in the first direction of the positive electrode body; and a negative electrode terminal that is electrically connected to the negative electrode part. The negative electrode part has a first negative electrode part and a second negative electrode part that are formed so as to be separated in the first direction. The positive electrode body has a first positive electrode part that is opposite the first negative electrode part, a second positive electrode part that is opposite the second negative electrode part, and a separation part that is between the first positive electrode part and the second positive electrode part and is not opposite the negative electrode part. The negative electrode terminal has a bottom surface part, and the first negative electrode part and the second negative electrode part are each electrically connected to the bottom surface part.

Description

Solid electrolytic capacitors

[0001] This disclosure relates to solid electrolytic capacitors.

[0002] Conventionally, surface-mount capacitors have been developed that combine the characteristics of both capacitors and filter circuits, with capacitances ranging from tens to hundreds of μF and impedances of approximately 5 mΩ or less in the 100 MHz frequency band, and are referred to as transmission line type elements or transmission line type noise filters.

[0003] As an example of a surface-mount capacitor used in a noise filter, the surface-mount capacitor described in Patent Document 1 comprises a box-shaped resin molded case base, a plurality of capacitor elements stacked with anodes at both ends and a cathode in the center, and a box-shaped case lid. If necessary, it further comprises a metal plate that is locked to the inside of the case lid to supplement the conductivity of the cathodes of the capacitor elements.

[0004] As an example of the configuration of a solid electrolytic capacitor used in a noise filter, Patent Document 2 proposes "a low-impedance solid electrolytic capacitor comprising a capacitor section having a dielectric oxide film formed on the surface of a metal substrate having a dielectric oxide film formed on its surface, wherein two capacitor sections are provided on the surface of the metal substrate at a predetermined distance apart, anode external terminal mounting sections are provided at both ends of the metal substrate, cathode external terminal mounting sections are provided on the two capacitor sections, ferrite is provided on the outer circumference of the metal substrate between the two capacitor sections, an anode external electrode terminal is attached to the anode external terminal mounting section, and a cathode external electrode terminal is attached to the cathode external terminal mounting section."

[0005] JP 2009-076651 JP 6-333790

[0006] Further improvements in noise filtering characteristics are desired for surface-mount capacitors.

[0007] Patent Document 2 describes a method for removing noise in the high-frequency range by winding and mounting a ferrite core between two capacitor sections. However, this increases the manufacturing process required to mount the ferrite core, leading to higher manufacturing costs. Furthermore, the increased inductance component due to the ferrite core can easily degrade the load characteristics.

[0008] In this context, one of the objectives of this disclosure is to realize a solid electrolytic capacitor that achieves a high level of compatibility between load characteristics and noise filter characteristics.

[0009] One aspect of the present disclosure relates to a solid electrolytic capacitor. The solid electrolytic capacitor comprises a capacitor element having an anode body extending in a first direction and a cathode portion formed on the surface of the anode body via a dielectric layer, a first anode terminal and a second anode terminal that are independent of each other and electrically connected to each of the two ends of the anode body in the first direction, a cathode terminal electrically connected to the cathode portion, and an outer resin covering the capacitor element, wherein the cathode portion has a first cathode portion and a second cathode portion that are separated and formed in the first direction, the anode body has a first anode portion facing the first cathode portion, a second anode portion facing the second cathode portion, and a separation portion located between the first anode portion and the second anode portion and not facing the cathode portion, and the cathode terminal has a bottom surface portion, and the first cathode portion and the second cathode portion are electrically connected to the bottom surface portion.

[0010] According to this disclosure, it is possible to improve noise filter characteristics while suppressing a decrease in load characteristics, thereby realizing a solid electrolytic capacitor that achieves a high level of compatibility between load characteristics and noise filter characteristics.

[0011] While novel features of the present invention are described in the appended claims, the present invention, both in terms of its structure and content, will be better understood by the following detailed description in conjunction with the drawings, along with other objects and features of the present invention.

[0012] This is a schematic side perspective view of the solid electrolytic capacitor of Embodiment 1. This is a schematic side cross-sectional view of the capacitor element. This is a schematic perspective view of the capacitor element. This is a schematic side perspective view of the solid electrolytic capacitor of Embodiment 2. This is a schematic side perspective view of the solid electrolytic capacitor of Embodiment 3. This is a schematic side perspective view of the solid electrolytic capacitor of Embodiment 4. This is a circuit diagram showing the equivalent circuit of the transmission line. This is a graph showing the pass characteristics of the solid electrolytic capacitor of Embodiment 1. This is a graph showing the pass characteristics of the solid electrolytic capacitor of Embodiment 2. This is a graph showing the pass characteristics of the solid electrolytic capacitor of Embodiment 3. This is a graph showing the pass characteristics of the solid electrolytic capacitor of Embodiment 4.

[0013] Embodiments of solid electrolytic capacitors relating to this disclosure will be described below with examples. However, this 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 this disclosure are obtained. In this specification, the description "numerical value A to numerical value B" includes numerical value A and numerical value B, and can be read as "greater than or equal to numerical value A and less than or equal to numerical value B". In the following description, when lower and upper limits of numerical values ​​relating to specific physical properties or conditions are given as examples, either the given lower limit and either the given upper limit may be arbitrarily combined as long as the lower limit does not exceed the upper limit. In the following description, when examples of components or methods are listed, unless otherwise specified, only one of the listed examples may be used, or multiple of the listed examples may be used in combination.

[0014] Furthermore, this disclosure encompasses any combination of matters described in two or more claims, which may be arbitrarily selected from the multiple claims set forth in the attached claims. In other words, any combination of matters described in two or more claims, which may be arbitrarily selected from the multiple claims set forth in the attached claims, is possible, provided that no technical inconsistency arises.

[0015] In the following explanation, the term "contains (or includes)" encompasses the expressions "contains (or includes)," "substantially consists of," and "consists of."

[0016] A solid electrolytic capacitor according to an embodiment of the present disclosure (hereinafter referred to as "the solid electrolytic capacitor according to this embodiment") has a noise filtering function and can be used as, for example, a three-terminal transmission line component. The solid electrolytic capacitor according to the present disclosure includes a capacitor element, two anode terminals, a cathode terminal, and an exterior resin. Note that two or more anode terminals may be provided, and one or more cathode terminals may be provided.

[0017] In a transmission line type solid electrolytic capacitor, an anode portion connecting between two anode terminals extends in one direction (here, referred to as the first direction) and forms one side of the transmission line. The cathode terminal, together with the wiring layer of the substrate electrically connected to the cathode terminal, forms the other side of the transmission line. There is a capacitive coupling between the anode portion and the cathode terminal. Note that the cathode terminal may extend in the first direction from one side to the other side of the two anode terminals, similar to the anode portion, or may be divided into a plurality of parts in the middle between the two anode terminals. Since the cathode terminal is usually connected to a ground power supply with a sufficiently low output impedance, it is equivalent to the case where the cathode terminal extends in the first direction.

[0018] Generally, a transmission line having two capacitively coupled signal lines is represented by an equivalent circuit shown in FIG. 7, and its characteristic impedance Z0 is given by the following formula 1, where L is the inductance per unit line length and C is the capacitance per unit line length. [Formula 1] Z0 = √(L / C) １／２

[0019] For the purpose of signal transmission, the characteristic impedance Z0 is set such that the combined impedance of the transmission line and the load (signal receiving side) is substantially equal to the impedance of the signal transmitting side. That is, the characteristic impedance Z0 has a function of matching the impedance of the signal transmitting side with the impedance of the signal receiving side. For the purpose of signal transmission, the L and C in the above formula 1 can be set such that the characteristic impedance Z0 usually becomes a specified value (for example, 50 Ω).

[0020] In contrast, in the present disclosure, the purpose is not signal transmission but noise removal, and rather, the purpose is to block the transmission of noise as an unnecessary signal. In this case, the characteristic impedance Z0 may be set to a value that does not match the impedance on the load side. By providing a location in the transmission line where the impedance is intentionally mismatched, the transmission line circuit can be modified to be used as a noise removal filter. The present invention has been made based on the above concept.

[0021] As a method of setting the characteristic impedance Z0 to a value that does not match the impedance on the load side, in the above formula 1, a method of making L small and / or making C large to bring the characteristic impedance Z0 closer to 0 (Z0≒0), and a method of making L large and / or making C small to make the characteristic impedance Z0 greater than 50Ω can be considered. However, if L is made too large, the load characteristics will deteriorate. In the solid electrolytic capacitor according to the present embodiment, by making L small (or suppressing an excessive increase in L that causes a deterioration in load characteristics even if a slight increase in L is allowed), and on the other hand, making C large, it is possible to achieve both high load characteristics and high noise filter characteristics.

[0022] In the solid electrolytic capacitor according to the present embodiment, the capacitor element has an anode body extending in a first direction and a cathode portion formed on the surface of the anode body via a dielectric layer. Both ends of the anode body in the first direction protrude from the cathode portion, and the protruding portions are electrically connected to the anode terminals. One of both ends of the anode body in the first direction is electrically connected to the first anode terminal, and the other is electrically connected to the second anode terminal. The first anode terminal and the second anode terminal constitute two independent terminals. The cathode portion is electrically connected to the cathode terminal. The capacitor element may further have an insulating portion provided between the anode body and the cathode portion and electrically insulating the two. The insulating portion may be composed of, for example, an insulating tape or an insulating resin.

[0023] The outer resin covers the capacitor element. The outer resin may cover the first anode terminal, the second anode terminal, and the cathode terminal so that a portion of each of the anode terminals (first and second anode terminals) and the cathode terminal is exposed. The exposed portions of the anode and cathode terminals function as external terminals of the solid electrolytic capacitor. The outer resin may be made of an insulating resin material. The outer resin may be a cured product of a thermosetting resin, such as epoxy resin, and may contain fillers as needed.

[0024] The cathode portion has a first cathode portion and a second cathode portion that are separated in a first direction. Corresponding to the first cathode portion and the second cathode portion, the anode body has a first anode portion facing the first cathode portion and a second anode portion facing the second cathode portion. A separation portion that does not face the cathode portion is provided between the first anode portion and the second anode portion of the anode body. The cathode terminal has a bottom surface, and the first cathode portion and the second cathode portion are electrically connected to the bottom surface.

[0025] The anode body has a first end continuous with the first anode portion and protruding from the first cathode portion, and a second end continuous with the second anode portion and protruding from the second cathode portion. The first end can be electrically connected to the first anode terminal, and the second end can be electrically connected to the second anode terminal.

[0026] The anode body extends in the first direction from the first end to the second end and constitutes one of the signal lines that make up the transmission line. The anode body is capacitively coupled to the cathode terminal (bottom surface), which is the other signal line that makes up the transmission line, via the cathode portion. However, since the isolation portion of the anode body does not face the cathode portion, there is no capacitive coupling with the cathode portion, and only inductive coupling exists with the first anode portion and the second anode portion. The equivalent circuit in this case corresponds to the equivalent circuit of the transmission line shown in Figure 7 with the capacitor in region X removed. The isolation portion is the part that causes the impedance mismatch described above (impedance mismatch portion).

[0027] By arranging a separation section (impedance mismatch section), noise rejection performance (pass-through characteristics) is improved, especially in the high-frequency range (100 MHz and above). Furthermore, by placing a capacitor element on the cathode terminal having a bottom surface, a solid electrolytic capacitor can be easily manufactured, and since no separate inductor component such as a ferrite core is provided to cover the separation section, a decrease in load characteristics is avoided. Therefore, the solid electrolytic capacitor according to this embodiment makes it possible to achieve both high load characteristics and high noise filtering characteristics without complicating the manufacturing process.

[0028] The bottom portion has at least a plate-like portion extending in a first direction, and the first cathode portion and the second cathode portion may each be electrically connected to the plate-like portion. The main surface of the plate-like portion may be parallel to the mounting surface of the solid electrolytic capacitor. The plate-like portion has a portion facing the first cathode portion and a portion facing the second cathode portion. The portion of the plate-like portion facing the first cathode portion and the portion facing the second cathode portion may be separated. That is, the bottom portion may have two spaced-apart plate-like portions, each having a portion facing the first cathode portion and a portion facing the second cathode portion. However, in terms of ease of manufacturing, it is preferable that the bottom portion has a single plate-like portion in which the portion facing the first cathode portion and the portion facing the second cathode portion are continuous.

[0029] Preferably, the bottom portion has a plate-like portion that extends continuously in the first direction from the portion facing the first cathode portion toward the portion facing the second cathode portion, so as to face the entirety of the first cathode portion and the second cathode portion in the first direction. In this case, a solid electrolytic capacitor can be easily manufactured by placing a capacitor element on the plate-like portion. Therefore, a solid electrolytic capacitor that achieves both high load characteristics and high noise filter characteristics can be realized without complicating the manufacturing process.

[0030] Multiple capacitor elements may be present. In this case, it is preferable that the multiple capacitor elements are stacked in a second direction perpendicular to the first direction such that the first cathode portions overlap and the second cathode portions overlap. This connects the multiple capacitor elements in parallel, increasing the capacitance of the solid electrolytic capacitor. As a result, the capacitance C of the transmission line in Equation 1 increases, improving the noise filter characteristics. In particular, the noise rejection performance (pass-through characteristics) in the low-frequency range (below 100 MHz) is improved.

[0031] The second direction (the stacking direction of the capacitor elements) may be perpendicular to the mounting surface of the solid electrolytic capacitor. The second direction may also be the height direction of the solid electrolytic capacitor.

[0032] The cathode terminal may have a first sidewall portion electrically connected to the side surface of the first cathode portion, and a second sidewall portion electrically connected to the side surface of the second cathode portion. Each of the first and second sidewall portions is connected to the bottom surface. Each of the first and second sidewall portions may be electrically connected to the sides of the first and second cathode portions via a conductive adhesive.

[0033] The first and second sidewalls reduce the impedance originating from the resistance and inductance components of the cathode terminal, thereby improving the noise filtering characteristics of the solid electrolytic capacitor. The first and second sidewalls also facilitate the positioning of the capacitor element on the bottom surface when placing the capacitor element on the bottom surface of the cathode terminal on which each sidewall is provided.

[0034] Two first sidewalls may be provided, corresponding to each of the opposing sides of the first cathode portion, so as to be electrically connected to each of the opposing sides of the first cathode portion. Similarly, two second sidewalls may be provided, corresponding to each of the opposing sides of the second cathode portion, so as to be electrically connected to each of the opposing sides of the second cathode portion. In this case, the capacitor element can be placed so as to be sandwiched between the two first sidewalls and the second cathode portion sandwiched between the two second sidewalls, making it easy to position the capacitor element on the bottom surface and easy to fix the capacitor element.

[0035] In the solid electrolytic capacitor according to this embodiment, when a plurality of capacitor elements are stacked, the first side wall portion may be arranged to be electrically connected to each of the first cathode portions of the plurality of capacitor elements. Similarly, the second side wall portion may be arranged to be electrically connected to each of the second cathode portions of the plurality of capacitor elements. In this case, if N is the number of stacked capacitor elements and h is the height of the capacitor element in the second direction, the protrusion height H of the first side wall portion and the second side wall portion from the bottom surface should be set to a height greater than (N-1)h, and the height should be set so that the first side wall portion and the second side wall portion do not protrude from the outer resin.

[0036] The anode body may be composed of a valve metal. Examples of valve metals that constitute the anode body include aluminum, tantalum, niobium, and titanium. The anode body may be a foil of the valve metal or a sintered body of valve metal particles. Adjacent anode bodies in the stacking direction may be electrically connected to each other.

[0037] The dielectric layer covers at least a portion of the surface of the anode. The dielectric layer may be composed of an oxide (e.g., aluminum oxide) formed on the surface of the anode by a liquid-phase method such as anodizing, or a vapor-phase method such as vapor deposition or atomic layer deposition. The dielectric layer is formed to interpose at least between the anode and the cathode.

[0038] The cathode portion (first cathode portion and second cathode portion) may have a solid electrolyte layer covering at least a portion of the surface of the dielectric layer and a cathode layer covering at least a portion of the surface of the solid electrolyte layer. Adjacent cathode portions in the stacking direction may be electrically connected to each other. The solid electrolyte layer may contain a conductive polymer. The solid electrolyte layer may further contain a dopant as needed.

[0039] As conductive polymers, known ones used in solid electrolytic capacitors, such as π-conjugated conductive polymers, can be used. Examples of conductive polymers include polymers with polypyrrole, polythiophene, polyaniline, polyfuran, polyacetylene, polyphenylene, polyphenylenevinylene, polyacene, and polythiophenevinylene as the basic skeleton. Of these, polymers with polypyrrole, polythiophene, or polyaniline as the basic skeleton are preferred. The above polymers also include homopolymers, copolymers of two or more monomers, and derivatives thereof (such as substituted products having substituents). For example, polythiophene includes poly(3,4-ethylenedioxythiophene). Conductive polymers may be used individually or in combination of two or more.

[0040] As the dopant, at least one selected from the group consisting of low molecular weight anions and polyanions is used. Examples of low molecular weight anions include sulfate ions, nitrate ions, phosphate ions, borate ions, organic sulfonate ions, and carboxylate ions, but are not particularly limited. Examples of dopants that generate organic sulfonate ions include benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. Examples of polyanions include high molecular weight polysulfonic acid and high molecular weight polycarboxylic acid. Examples of high molecular weight polysulfonic acid include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylic sulfonic acid, and polymethacrylatesulfonic acid. Examples of high molecular weight polycarboxylic acid include polyacrylic acid and polymethacrylate. Polyanions also include polyestersulfonic acid and phenolsulfonic acid novolac resins. However, polyanions are not limited to these.

[0041] The solid electrolyte layer may optionally further contain known additives and known conductive materials other than conductive polymers. Examples of such conductive materials include at least one selected from the group consisting of conductive inorganic materials such as manganese dioxide and TCNQ complex salts.

[0042] The cathode layer may consist of a carbon layer formed on the surface of the solid electrolyte layer and a conductive layer formed on the surface of the carbon layer. The conductive layer may consist of silver paste. As the silver paste, for example, a composition containing silver particles and a resin component (binder resin) can be used. As the resin component, a thermoplastic resin can be used, but it is preferable to use a thermosetting resin such as an imide resin or an epoxy resin.

[0043] The impedance in the isolation section (impedance mismatch section) can be adjusted to a desired value. To increase the impedance value of the isolation section, the width in the third direction perpendicular to the first direction in the isolation section of the anode body may be made smaller than the width in the third direction in the first anode section (and second anode section) of the anode body. The third direction may be parallel to the second direction (the stacking direction of the capacitor elements), or it may be intersecting the second direction. The third direction may be perpendicular to the first direction and intersecting the mounting surface of the solid electrolytic capacitor, or it may be perpendicular to the first direction and parallel to the mounting surface of the solid electrolytic capacitor.

[0044] For example, as mentioned above, when the anode body is composed of a foil of valve-acting metal (anode foil), the anode foil has a main surface parallel to at least the first direction. The width of the separation portion of the anode foil in the direction parallel to the main surface and perpendicular to the first direction may be smaller than the width of the first anode portion (and second anode portion) of the anode foil in the direction perpendicular to the first direction. In this case, the third direction may be parallel to the main surface of the anode foil and perpendicular to the second direction. Also, the thickness of the separation portion of the anode foil may be smaller than the thickness of the first anode portion (and second anode portion) of the anode foil. In this case, the third direction is the thickness direction of the anode foil, and may be perpendicular to the main surface of the anode foil and parallel to the second direction.

[0045] However, if the width in the third direction of the separation portion of the anode body is made too small compared to the width in the third direction of the first anode portion (and second anode portion) of the anode body, the load characteristics will deteriorate significantly. In order to improve noise filter characteristics while maintaining high load characteristics, it is preferable that the width in the third direction of the separation portion of the anode body be 50% or more and 100% or less of the width in the third direction of the first anode portion (and second anode portion) of the anode foil. When the anode body is an anode foil, it is preferable that the width in the separation portion of the anode foil be 50% or more and 100% or less of the width of the first anode portion (and second anode portion), and the thickness in the separation portion of the anode foil be 50% or more and 100% or less of the thickness of the first anode portion (and second anode portion).

[0046] Similarly, in order to increase the impedance value of the separation section (impedance mismatch section), the length in the first direction of the separation section of the anode body may be made longer than the length in the first direction of the first anode section (and second anode section) of the anode body. However, if the length in the first direction of the separation section of the anode body is made too long compared to the length in the first direction of the first anode section (and second anode section) of the anode body, the load characteristics will deteriorate significantly. In order to improve noise filter characteristics while maintaining high load characteristics, it is preferable that the length in the first direction of the separation section of the anode body is 200% or less of the length in the first direction of the first anode section (and second anode section) of the anode body.

[0047] The cathode terminal may have multiple protrusions projecting in the opposite direction to the anode. Each protrusion is electrically connected to the bottom surface, and at least a portion of the protruding surface of each protrusion is exposed from the exterior resin. Each of the multiple protrusions can be electrically connected in parallel to an external electrode terminal provided on the substrate. Therefore, if the number of protrusions is N, the inductance component due to the multiple protrusions is 1 / N of the inductance component due to a single protrusion, thereby reducing the contribution of the inductance originating from the cathode terminal in the solid electrolytic capacitor. As a result, the overall impedance of the solid electrolytic capacitor is reduced, and the noise filter characteristics of the solid electrolytic capacitor can be improved.

[0048] The protrusion may be formed by bending a plate-shaped cathode terminal. Multiple conductive members may also be attached to the side of the cathode terminal opposite to the side on which the capacitor element is mounted, forming the protrusion.

[0049] The two anode terminals are electrically connected to the two protrusions of the anode body, respectively. In other words, one anode terminal (first anode terminal) is electrically connected to the end of the anode body protruding from the first cathode portion, and the other anode terminal (second anode terminal) is electrically connected to the end of the anode body protruding from the second cathode portion. In each capacitor element, the two ends of the anode body are electrically conductive to each other. The anode terminals may be made of copper, a copper alloy, aluminum, or an aluminum alloy, and may be plated.

[0050] The first and second anode terminals may be electrically connected to the two ends of each anode body of a plurality of capacitor elements. The anode terminals may be electrically connected to the ends by crimping or by welding (e.g., laser welding or resistance welding).

[0051] The first sidewall may be positioned closer to the first anode terminal in the first direction. By positioning the first sidewall closer to the first anode terminal, noise rejection performance in the high-frequency range is improved. Specifically, in the first direction, the first sidewall may be positioned off-center towards the first anode terminal than the center of the first cathode. The position of the boundary of the first sidewall on the first anode terminal side in the first direction should be brought closer to the first anode terminal. For example, in the first direction, the boundary of the first sidewall on the first anode terminal side may have a width of R in the first direction of the first cathode. １ As such, 0.4R from the boundary on the first anode terminal side of the first cathode section. １ It may be located closer to the first anode terminal than to the second anode terminal. However, if the first sidewall is brought too close to the first anode terminal, the first sidewall is more likely to come into contact with the first anode portion or the first anode terminal, potentially causing a short circuit. Therefore, the boundary of the first sidewall on the first anode terminal side should be 0.08R from the boundary of the first cathode portion on the first anode terminal side. １It is preferably on the second anode terminal side rather than just the position on the second anode terminal side. That is, the boundary on the first anode terminal side of the first side wall portion is 0.08R from the boundary on the first anode terminal side of the first cathode portion in the first direction. １ It is preferably located between just the position on the second anode terminal side and 0.4R from the boundary on the first anode terminal side of the first cathode portion. １ It is preferably located between just the position on the second anode terminal side and the above.

[0052] Similarly, the second side wall portion may be arranged closer to the second anode terminal in the first direction. By arranging the second side wall portion closer to the second anode terminal, the noise removal performance (pass characteristics) in the high-frequency region is improved. Specifically, in the first direction, the second side wall portion may be offset toward the second anode terminal side from the center of the second cathode portion. The position of the boundary on the second anode terminal side of the second side wall portion in the first direction may be made closer to the second anode terminal. For example, in the first direction, the boundary on the second anode terminal side of the second side wall portion is 0.4R from the boundary on the second anode terminal side of the second cathode portion with the width of the second cathode portion in the first direction being R. ２ It may be on the second anode terminal side rather than just the position on the first anode terminal side. However, if the second side wall portion is too close to the second anode terminal, the second side wall portion is likely to contact the second anode portion or the second anode terminal, resulting in a risk of short circuit. Therefore, the boundary on the second anode terminal side of the second side wall portion is preferably on the second anode terminal side rather than just the position on the first anode terminal side. That is, the boundary on the second anode terminal side of the second side wall portion is 0.08R from the boundary on the second anode terminal side of the second cathode portion in the first direction. ２ It is preferably located between just the position on the first anode terminal side and 0.4R from the boundary on the second anode terminal side of the second cathode portion. ２ It is preferably on the second anode terminal side rather than just the position on the first anode terminal side. That is, the boundary on the second anode terminal side of the second side wall portion is 0.08R from the boundary on the second anode terminal side of the second cathode portion in the first direction. ２ It is preferably located between just the position on the first anode terminal side and 0.4R from the boundary on the second anode terminal side of the second cathode portion. ２ It is preferably located between just the position on the first anode terminal side and the above.

[0053] The shapes of the first side wall portion and the second side wall portion of the cathode terminal are not limited. For example, they may be composed of a plurality of columnar portions.

[0054] The cathode terminal may be electrically connected to the cathode section (first cathode section and second cathode section) via a conductive adhesive. The cathode terminal may be made of copper, copper alloy, aluminum, or aluminum alloy, and may be plated. The constituent material of the cathode terminal may be the same as or different from the constituent material of the anode terminal. The cathode terminal may be divided into two or more sections.

[0055] In a capacitor element, the first cathode portion and the second cathode portion may have the same shape.

[0056] In the solid electrolytic capacitor according to this embodiment, the capacitor element can be said to have a configuration in which a first element section having a first cathode section and a first anode section and a second element section having a second cathode section and a second anode section are connected by connecting the first anode section and the second anode section via a separation section (impedance mismatch section). The first element section and the second element section may have the same structure. That is, the capacitor element may be formed by connecting the anode sections of the first element section and the second element section having the same element structure. By using transmission line type capacitor elements with the same configuration in the first element section and the second element section, manufacturing costs can be reduced.

[0057] The first anode portion, the separation portion, and the second anode portion of the anode body may be integrally formed. In the fabrication of the capacitor element, there is no need to connect the anode portions of the first element portion and the second element portion, thus simplifying the manufacture of solid electrolytic capacitors.

[0058] One or more element sections may be connected between the first element section and the second element section, with multiple isolation sections in between. That is, the cathode section has a third cathode section formed separately from the first and second cathode sections, and the anode body has a third anode section facing the third cathode section. Isolation sections that do not face the cathode section may be interposed between the first and third anode sections and between the third and second anode sections. In the solid electrolytic capacitor according to this embodiment, the number of element sections or the number of isolation sections (impedance mismatch sections) is not particularly limited.

[0059] Hereinafter, an example of a solid electrolytic capacitor according to this disclosure will be specifically described with reference to the drawings. The components of the example solid electrolytic capacitor described below can be the components described above. The components of the example solid electrolytic capacitor described below can be modified based on the above description. Furthermore, the matters described below may be applied to the above embodiments. Among the components of the example solid electrolytic capacitor described below, components that are not essential to the solid electrolytic capacitor according to this disclosure may be omitted. Note that the figures shown below are schematic and do not accurately reflect the actual shape and number of components.

[0060] Embodiment 1 of the present disclosure will now be described. The solid electrolytic capacitor 10 of this embodiment comprises a capacitor element 11, two anode terminals 17a and 17b, a cathode terminal 18, and an outer resin 19, as shown in Figures 1 to 3. In Figure 1, the first side wall portion 18b and the second side wall portion 18c, which will be described later, are shown by dashed lines.

[0061] The capacitor element 11 has an anode body 12 and a cathode portion 13 formed on the surface of the anode body 12 via a dielectric layer 14. The cathode portion 13 has a first cathode portion 13a and a second cathode portion 13b, and the first cathode portion 13a and the second cathode portion 13b are separated by a separation portion 12c of the anode body 12.

[0062] The anode body 12 has a first anode portion 12a, a second anode portion 12b, a separation portion 12c, a first end portion 12d, and a second end portion 12e. The first anode portion 12a faces the first cathode portion 13a via a dielectric layer 14. The second anode portion 12b faces the second cathode portion 13b via a dielectric layer 14. The separation portion 12c is the portion sandwiched between the first anode portion 12a and the second anode portion 12b. The first end portion 12d is the portion of the anode body 12 that protrudes from the first cathode portion 13a on the opposite side of the separation portion 12c. The second end portion 12e is the portion of the anode body 12 that protrudes from the second cathode portion 13b on the opposite side of the separation portion 12c.

[0063] The anode body 12 extends in a first direction (left-right direction in Figure 1) from the first end 12d to the second end 12e, via the first anode portion 12a, the separation portion 12c, and the second anode portion 12b. The anode body 12 is composed of a foil of a valve-acting metal (aluminum in this example), but is not limited to this.

[0064] The dielectric layer 14 covers at least a portion of the surface of the anode 12. The dielectric layer 14 is composed of an oxide (aluminum oxide in this example) formed on the surface of the anode 12 that has undergone a roughening treatment, but is not limited to this.

[0065] The cathode portion 13 (first cathode portion 13a and second cathode portion 13b) has a solid electrolyte layer covering at least a portion of the dielectric layer 14 and a cathode layer covering at least a portion of the surface of the solid electrolyte layer. The solid electrolyte layer contains a conductive polymer and a dopant.

[0066] The cathode layer consists of a carbon layer formed on the surface of the solid electrolyte layer and a conductive layer formed on the surface of the carbon layer. The conductive layer may be made of silver paste.

[0067] An insulating portion 15 may be provided between the first cathode portion 13a and the first end portion 12d and the separation portion 12c of the anode body, and between the second cathode portion 13b and the second end portion 12e and the separation portion 12c of the anode body, for electrically insulating the two.

[0068] In the capacitor element 11, a first element section (first capacitance element section) is formed by a first anode section 12a and a first cathode section 13a. A second element section (second capacitance element section) is formed by a second anode section 12b and a second cathode section 13b. The anode sections of the first element section and the second element section are connected via a separator section 12c having an inductor component, and together they constitute a single capacitor element 11.

[0069] The anode terminals 17a and 17b are electrically connected to the first end 12d and the second end 12e of the anode body 12, respectively. The anode terminals 17a and 17b are made of a copper alloy, but are not limited to this. The anode terminal 17a may be electrically connected to the first end 12d by crimping, and the anode terminal 17b may be electrically connected to the second end 12e by crimping. Alternatively, or in addition to crimping, the anode terminal 17a may be welded to the first end 12d, and the anode terminal 17b may be welded to the second end 12e.

[0070] The cathode terminal 18 is electrically connected to the first cathode portion 13a and the second cathode portion 13b, respectively, for example, via a conductive adhesive. The cathode terminal 18 is made of a copper alloy, but is not limited to this. The constituent material of the cathode terminal 18 may be the same as the constituent material of the anode terminal 17.

[0071] The cathode terminal 18 has a bottom surface 18a, a first side wall 18b, and a second side wall 18c. The first side wall 18b rises continuously from the bottom surface 18a and is connected to the side surface of the first cathode portion 13a. The second side wall 18c rises continuously from the bottom surface 18a and is connected to the side surface of the second cathode portion 13b. The top surface of the bottom surface 18a is electrically connected to the first cathode portion 13a and the second cathode portion 13b of the capacitor element 11, while at least a portion of its bottom surface is exposed from the exterior resin 19.

[0072] The first sidewall portion 18b may be electrically connected to the side surface of the first cathode portion 13a via a conductive adhesive (not shown). The second sidewall portion 18c may be electrically connected to the side surface of the second cathode portion 13b via a conductive adhesive (not shown). The first sidewall portion 18b may be provided on both sides of the side surface of the first cathode portion 13a. The second sidewall portion 18c may be provided on both sides of the side surface of the second cathode portion 13b.

[0073] The outer resin 19 covers the capacitor element 11, the anode terminals 17a and 17b, and the cathode terminal 18, such that a portion of each of the anode terminals 17a and 17b and the cathode terminal 18 is exposed. The exposed portions of each of the anode terminals 17a and 17b and the cathode terminal 18 function as external terminals of the solid electrolytic capacitor 10. The outer resin 19 is made of an insulating resin material containing filler.

[0074] As shown in Figure 3, the separation portion 12c of the anode body 12 is not covered by the cathode portion, but is covered by the outer resin 19. The separation portion 12c has an inductive component. The length of the separation portion 12c in the first direction (length in the left-right direction in Figure 1) L １ The width of the separation section 12c (length in the direction perpendicular to the plane of the paper in Figure 1) W １ , and / or the thickness of the separation portion 12c (length in the vertical direction in Figure 1) D １ By changing this, the magnitude of the inductor component can be controlled. In terms of improving noise filter characteristics while maintaining high load characteristics, the width W of the separation section 12c １ and thickness D １ The width W of the first anode portion 12a and / or the second anode portion 12b is, respectively. ２ And the amount may be 50% or more and 100% or less of the thickness.

[0075] Similarly, in terms of improving noise filter characteristics while maintaining high load characteristics, the length L in the first direction of the separation section 12c is important. １ This may be 100% or more and 200% or less of the length of the first anode portion 12a and / or the second anode portion 12b in the first direction.

[0076] Embodiment 2 Embodiment 2 of the present disclosure will now be described. The solid electrolytic capacitor 10A of this embodiment comprises a laminate in which a plurality of capacitor elements are stacked. The differences from Embodiment 1 described above will be explained below.

[0077] As shown in Figure 4, the solid electrolytic capacitor 10A comprises a plurality of capacitor elements 11A to 11C, and the plurality of capacitor elements 11A to 11C are stacked in a second direction (up and down direction in Figure 4) perpendicular to the first direction. In the example of Figure 4, the second direction is perpendicular to the mounting surface of the solid electrolytic capacitor and perpendicular to the bottom surface 18a, but is not limited to this.

[0078] Capacitor elements 11A to 11C have the same configuration as capacitor element 11 of Embodiment 1 described above. Capacitor elements 11A to 11C are stacked in a second direction such that the first cathode portions 13a of capacitor elements 11A to 11C overlap with each other and the second cathode portions 13b of capacitor elements 11A to 11C overlap with each other, thereby forming a laminate.

[0079] In the stacking direction, adjacent first cathode portions 13a are electrically connected to each other via the conductive paste 16. Similarly, adjacent second cathode portions 13b in the stacking direction are electrically connected to each other via the conductive paste 16. Therefore, all first cathode portions 13a are electrically connected to each other, and all second cathode portions 13b are electrically connected to each other. The first cathode portions 13a and second cathode portions 13b of the capacitor element 11A, which is stacked in the lowest layer of the laminate, are electrically connected to the bottom surface portion 18a.

[0080] In the stacking direction, adjacent anode bodies 12 are electrically connected to each other by the first end 12d of each capacitor element being electrically connected to the anode terminal 17a, and the second end 12e of each capacitor element being electrically connected to the anode terminal 17b. Thus, all anode bodies 12 are electrically connected to each other.

[0081] The first sidewall portion 18b covers at least a portion of the side surface of the first cathode portion 13a of the capacitor element 11A, which is stacked in the uppermost layer of the laminate. The second sidewall portion 18c covers at least a portion of the side surface of the second cathode portion 13b of the capacitor element 11A, which is stacked in the uppermost layer of the laminate. As a result, the first sidewall portion 18b is electrically connected to the side surface of the first cathode portion 13a of all capacitor elements 11A to 11C. The second sidewall portion 18c is electrically connected to the side surface of the second cathode portion 13b of all capacitor elements 11A to 11C.

[0082] In the above example, three capacitor elements 11A to 11C are stacked in the laminate, but the number of stacked capacitor elements is not limited to this.

[0083] Embodiment 3 Embodiment 3 of the present disclosure will now be described. The solid electrolytic capacitor 10B of this embodiment differs from that of Embodiment 1 in the configuration of the cathode terminal 18. The differences from Embodiment 1 will be mainly described below.

[0084] In the solid electrolytic capacitor 10B shown in Figure 5, the cathode terminal 18 has a plurality of protrusions 18d. Each of the plurality of protrusions 18d is electrically connected to the bottom surface 18a and protrudes in the direction opposite to the anode body 12. At least a portion of the protruding surfaces of the plurality of protrusions 18d are exposed from the outer resin 19 and constitute the external cathode terminal of the solid electrolytic capacitor 10B.

[0085] The projection 18d is formed by bending the end of the cathode terminal 18 in the first direction away from the anode body 12 relative to the bottom surface 18a, and exposing a part of the end from the outer resin. The projection 18d is continuous with the bottom surface 18a. However, it is not limited to this, and a projection member separate from the bottom surface 18a may be attached to the main surface of the bottom surface 18a opposite to the anode body and constitute the projection 18d. There may be multiple projections 18d, and there is no particular limit to the number of projections 18d.

[0086] The multiple protrusions 18d may be arranged in a line in the first direction.

[0087] A configuration in which the capacitor elements of Embodiment 2 are stacked on the solid electrolytic capacitor 10B of Embodiment 3 may also be used.

[0088] Embodiment 4 Embodiment 4 of the present disclosure will now be described. The solid electrolytic capacitor 10C of this embodiment differs from Embodiment 1 in the configuration of the first side wall portion 18b and the second side wall portion 18c. The differences from Embodiment 1 will be mainly described below.

[0089] As shown in Figure 6, compared to the solid electrolytic capacitor 10 of Embodiment 1 (see Figure 1), the solid electrolytic capacitor 10C has its first sidewall portion 18b closer to the first anode terminal 17a and positioned off-center towards the first anode terminal 17a rather than the center of the first cathode portion 13a in the first direction, and its second sidewall portion 18c closer to the second anode terminal 17b and positioned off-center towards the second anode terminal 17b rather than the center of the second cathode portion 13b in the first direction. As a result, the current path flowing from the anode terminal to the cathode is shortened, and the noise rejection performance in the high-frequency range can be improved.

[0090] In Figure 5, position Q in the first direction of the boundary of the first side wall portion 18b on the side of the first anode terminal 17a. １ The center of the first cathode portion 13a (the width of the first cathode portion 13a in the first direction is R) １ For example, position P in the first direction of the boundary on the first anode terminal 17a side of the first cathode portion 13a. １ From R １ / 2 is located closer to the first anode terminal 17a than the position on the second anode terminal 17b side. Position Q １ is at position P １ From 0.4R １ Preferably, the position P is located closer to the first anode terminal 17a than to the second anode terminal 17b. １ From 0.25R １ It is more preferable that the position is closer to the first anode terminal 17a than to the second anode terminal 17b. However, the boundary position Q of the first side wall portion 18b １ If the first anode terminal 17a is brought too close, the first side wall portion 18b is likely to come into contact with the first anode portion or the first anode terminal, which could cause a short circuit. For this reason, position Q １ is at position P １ From 0.08R １ It is preferable that the position be closer to the second anode terminal than the position on the second anode terminal 17b side. That is, position Q １ In the first direction, position P １ From 0.08R １ Only the position on the second anode terminal 17b side and position P １ From 0.4R １ It is preferable that it be located between the position on the second anode terminal 17b side and the other position.

[0091] Similarly, position Q in the first direction of the boundary of the second side wall portion 18c on the second anode terminal 17b side ２ The center of the second cathode portion 13b (the width of the second cathode portion 13b in the first direction is R) ２ For example, position P in the first direction of the boundary on the second anode terminal 17b side of the second cathode portion 13b. ２ From R １ / 2 is located closer to the second anode terminal 17b than the position on the first anode terminal 17a side. Position Q ２ is at position P ２ From 0.4R ２ Preferably, the position P is located closer to the second anode terminal 17b than to the first anode terminal 17a. ２ From 0.25R ２ It is more preferable that the position is closer to the second anode terminal 17b than to the first anode terminal 17a. However, the boundary position Q of the second side wall portion 18c ２ If the second anode terminal 17b is brought too close, the second side wall portion 18c is likely to come into contact with the second anode portion or the second anode terminal, which could cause a short circuit. For this reason, position Q ２ is at position P ２ From 0.08R ２ It is preferable that the position is closer to the first anode terminal than the position on the first anode terminal 17a side. That is, position Q ２ In the first direction, position P ２ From 0.08R １ Only the position on the first anode terminal 17a side and position P ２ From 0.4R ２ It is preferable that it be located between the position on the first anode terminal 17a side and the other position.

[0092] The solid electrolytic capacitor 10C of Embodiment 4 may be combined with the capacitor element of Embodiment 2, and / or the cathode terminal having a protrusion.

[0093] 《Note》 The above description of embodiments discloses the following technology. (Technology 1) A capacitor element comprising: an anode body extending in a first direction and a cathode portion formed on the surface of the anode body via a dielectric layer; a first anode terminal and a second anode terminal, which are independent of each other and electrically connected to each of the two ends of the anode body in the first direction; a cathode terminal electrically connected to the cathode portion; and an outer resin covering the capacitor element, wherein the cathode portion has a first cathode portion and a second cathode portion that are separated and formed in the first direction; the anode body has a first anode portion facing the first cathode portion, a second anode portion facing the second cathode portion, and a separation portion located between the first anode portion and the second anode portion and not facing the cathode portion; and the cathode terminal has a bottom surface portion, with the first cathode portion and the second cathode portion each electrically connected to the bottom surface portion. (Technology 2) The solid electrolytic capacitor according to Technology 1, wherein the cathode terminal has a first sidewall portion electrically connected to the side surface of the first cathode portion and a second sidewall portion electrically connected to the side surface of the second cathode portion, and each of the first sidewall portion and the second sidewall portion is connected to the bottom portion. (Technology 3) The solid electrolytic capacitor according to Technology 1, wherein the capacitor has a plurality of capacitor elements, and the plurality of capacitor elements are stacked in a second direction perpendicular to the first direction such that the first cathode portions overlap each other and the second cathode portions overlap each other, and the cathode terminal has a first sidewall portion electrically connected to the side surface of the first cathode portion and a second sidewall portion electrically connected to the side surface of the second cathode portion, the first sidewall portion is electrically connected to each of the first cathode portions of the plurality of capacitor elements and the second sidewall portion is electrically connected to each of the second cathode portions of the plurality of capacitor elements. (Technical 4) The solid electrolytic capacitor according to any one of Technical 1 to 3, wherein the width in the third direction perpendicular to the first direction in the separation portion of the anode body is smaller than the width in the third direction in the first anode portion of the anode body.(Technical 5) The anode body is an anode foil having main surfaces parallel to the first and third directions, and the width in the third direction at the separation portion of the anode foil is smaller than the width in the third direction at the first anode portion of the anode foil, as described in Technical 4. (Technical 6) The anode body is an anode foil having main surfaces parallel to the first direction and perpendicular to the third direction, and the thickness in the separation portion of the anode foil is smaller than the thickness at the first anode portion of the anode foil, as described in Technical 4 or 5. (Technical 7) The length in the first direction at the separation portion of the anode body is longer than the length in the first direction at the first anode portion of the anode body, as described in any one of Technical 1 to 6. (Technical 8) The cathode terminal has a plurality of protrusions, each electrically connected to the bottom surface portion and protruding in the direction opposite to the anode body, and at least a part of the protruding surface of the protrusions is exposed from the exterior resin, as described in any one of Technical 1 to 7. (Technical 9) The first anode terminal is electrically connected to the end of the anode body protruding from the first cathode portion, and in the first direction, the first side wall portion is positioned off-center towards the first anode terminal than the center of the first cathode portion, as described in Technical 2 or 3, a solid electrolytic capacitor. (Technical 10) The first anode terminal is electrically connected to the end of the anode body protruding from the first cathode portion, and in the first direction, the boundary of the first side wall portion on the first anode terminal side is R, where R is the width of the first cathode portion in the first direction. １ As such, 0.4R from the boundary on the first anode terminal side of the first cathode portion. １A solid electrolytic capacitor according to Technology 2 or 3, wherein the position of the first anode terminal is closer to the first anode terminal than the position of the second anode terminal. (Technology 11) A solid electrolytic capacitor according to any one of Technology 1 to 10, wherein the bottom portion has a plate-like portion that extends continuously in the first direction from the portion facing the first cathode portion toward the portion facing the second cathode portion, so as to face the entirety of the first cathode portion and the second cathode portion in the first direction. (Technology 12) A solid electrolytic capacitor according to any one of Technology 1 to 11, wherein the first cathode portion and the second cathode portion have the same shape, and the capacitor element is configured such that a first element portion having the first cathode portion and the first anode portion and a second element portion having the second cathode portion and the second anode portion are connected by connecting the separation portion, and the first element portion and the second element portion have the same structure. (Technical 13) A solid electrolytic capacitor according to any one of Technical 1 to 12, wherein the first anode portion, the separation portion, and the second anode portion of the anode body are integrally formed. (Technical 14) A solid electrolytic capacitor according to any one of Technical 1 to 13, which does not have an inductor member covering the separation portion.

[0094] The following shows the results of characteristic evaluations performed on the solid electrolytic capacitors of the examples and comparative examples shown below.

[0095] <Example 1> A solid electrolytic capacitor 10 of the type shown in Embodiment 1 above was designed and a circuit simulation was performed. A capacitor element was constructed comprising a first anode portion 12a, a second anode portion 12b having a predetermined length in a first direction, and a separation portion 12c between the first anode portion 12a and the second anode portion 12b. The first sidewall portion 18b and the second sidewall portion 18c were positioned at the center of the first cathode portion 13a and the second cathode portion 13b in the first direction, respectively. The pass-through characteristics of the electrolytic capacitor were calculated for the solid electrolytic capacitor A1 with this configuration.

[0096] 《Comparative Example 1》 A solid electrolytic capacitor having a configuration similar to the solid electrolytic capacitor described in Patent Document 2 was designed and a circuit simulation was performed. Two cathode portions (capacitor portions) were formed spaced apart in a first direction so as to cover the anode portion. The lengths of the two capacitor portions in the first direction were the same as the lengths of the first anode portion 12a and the second anode portion 12b in the first direction in Example 1, and the spacing distance between the two capacitor portions was the same as the length of the separation portion 12c in Example 1. A ferrite core was placed in the spaced region between the capacitor portions. The two capacitor portions were electrically connected to a common cathode terminal via cathode leads. The pass-through characteristics of the electrolytic capacitor were calculated for the solid electrolytic capacitor B1 with this configuration.

[0097] Figure 8 shows the pass characteristics of solid electrolytic capacitors A1 and B1. Compared to solid electrolytic capacitor B1, solid electrolytic capacitor A1 shows improved noise reduction performance in the high-frequency range (above 100 MHz).

[0098] <Example 2> A solid electrolytic capacitor 10A of the type shown in Embodiment 2 above was designed and a circuit simulation was performed. The number of capacitor elements in the laminate was set to three, and the configuration of the capacitor elements was the same as in Embodiment 1. The pass characteristics of the electrolytic capacitor were calculated for the solid electrolytic capacitor A2 with this configuration.

[0099] Figure 9 shows the pass characteristics of solid electrolytic capacitor A2, along with those of solid electrolytic capacitor B1. Compared to solid electrolytic capacitor B1, solid electrolytic capacitor A2 exhibits improved noise reduction performance in the low-frequency range (below 100 MHz).

[0100] <Example 3> A solid electrolytic capacitor 10B of the type shown in Embodiment 3 above was designed and a circuit simulation was performed. By bending both ends of the cathode terminal 18 in the first direction, two protrusions 18d protruding from the bottom surface 18a were formed. The rest was the same as in Embodiment 1. The pass characteristics of the electrolytic capacitor were calculated for the solid electrolytic capacitor A3 with this configuration.

[0101] Figure 10 shows the pass characteristics of solid electrolytic capacitor A3, along with those of solid electrolytic capacitor A1. Solid electrolytic capacitor A3 exhibits improved noise reduction performance in the high-frequency range (above 100 MHz) compared to solid electrolytic capacitor A1.

[0102] <Example 4> A solid electrolytic capacitor 10C of the type shown in Embodiment 4 above was designed and a circuit simulation was performed. In Embodiment 1, the first side wall portion 18b was positioned off-center towards the first anode terminal 17a, and the second side wall portion 18c was positioned off-center towards the second anode terminal 17b. The rest was the same as in Embodiment 1. The pass characteristics of the electrolytic capacitor were calculated for the solid electrolytic capacitor A4 with this configuration.

[0103] Figure 11 shows the pass-through characteristics of solid electrolytic capacitor A4, along with those of solid electrolytic capacitor A1. Solid electrolytic capacitor A4 exhibits improved noise reduction performance in the high-frequency range (above 100 MHz) compared to solid electrolytic capacitor A1.

[0104] This disclosure can be used in solid electrolytic capacitors.

[0105] Although the present invention has been described in relation to preferred embodiments at present, such disclosure should not be interpreted restrictively. Various modifications and alterations will undoubtedly become apparent to those skilled in the art in the field to which the invention pertains by reading the above disclosure. Accordingly, the appended claims should be interpreted as encompassing all modifications and alterations without departing from the true spirit and scope of the invention.

[0106] 10: Solid electrolytic capacitor 11: Capacitor element 12: Anode body 12a: First anode part 12b: Second anode part 12c: Separation part 12d: First end part 12e: Second end part 13: Cathode part 13a: First cathode part 13b: Second cathode part 14: Dielectric layer 15: Insulating part 16: Conductive paste 17: Anode terminal 18: Cathode terminal 18a: Bottom part 18b: First side wall part 18c: Second side wall part 18d: Protrusion part 19: Outer resin

Claims

1. A solid electrolytic capacitor comprising: an anode body extending in a first direction and a cathode portion formed on the surface of the anode body via a dielectric layer; a first anode terminal and a second anode terminal, which are independent of each other and electrically connected to each of the two ends of the anode body in the first direction; a cathode terminal electrically connected to the cathode portion; and an outer resin covering the capacitor element, wherein the cathode portion has a first cathode portion and a second cathode portion that are separated and formed in the first direction; the anode body has a first anode portion facing the first cathode portion, a second anode portion facing the second cathode portion, and a separation portion located between the first anode portion and the second anode portion and not facing the cathode portion; and the cathode terminal has a bottom surface portion, with the first cathode portion and the second cathode portion each electrically connected to the bottom surface portion.

2. The solid electrolytic capacitor according to claim 1, wherein the cathode terminal has a first sidewall portion electrically connected to the side surface of the first cathode portion and a second sidewall portion electrically connected to the side surface of the second cathode portion, and each of the first sidewall portion and the second sidewall portion is connected to the bottom portion.

3. The solid electrolytic capacitor according to claim 1, comprising a plurality of capacitor elements, wherein the plurality of capacitor elements are stacked in a second direction perpendicular to the first direction such that the first cathode portions overlap each other and the second cathode portions overlap each other, and the cathode terminal has a first sidewall portion electrically connected to the side surface of the first cathode portion and a second sidewall portion electrically connected to the side surface of the second cathode portion, wherein the first sidewall portion is electrically connected to each of the first cathode portions of the plurality of capacitor elements, and the second sidewall portion is electrically connected to each of the second cathode portions of the plurality of capacitor elements.

4. The solid electrolytic capacitor according to claim 1, wherein the width in the third direction perpendicular to the first direction at the separation portion of the anode body is smaller than the width in the third direction at the first anode portion of the anode body.

5. The solid electrolytic capacitor according to claim 4, wherein the anode body is an anode foil having main surfaces parallel to the first and third directions, and the width in the third direction at the separation portion of the anode foil is smaller than the width in the third direction at the first anode portion of the anode foil.

6. The solid electrolytic capacitor according to claim 4, wherein the anode body is an anode foil having a main surface parallel to the first direction and perpendicular to the third direction, and the thickness of the separation portion of the anode foil is smaller than the thickness of the first anode portion of the anode foil.

7. The solid electrolytic capacitor according to claim 1, wherein the length in the first direction of the separation portion of the anode body is longer than the length in the first direction of the first anode portion of the anode body.

8. The solid electrolytic capacitor according to claim 1, wherein each cathode terminal is electrically connected to the bottom surface and has a plurality of protrusions that protrude in the opposite direction to the anode body, and at least a portion of the protruding surfaces of the protrusions is exposed from the outer resin.

9. The solid electrolytic capacitor according to claim 2 or 3, wherein the first anode terminal is electrically connected to the end of the anode body protruding from the first cathode portion, and in the first direction, the first side wall portion is positioned off-center towards the first anode terminal than the center of the first cathode portion.

10. The first anode terminal is electrically connected to the end of the anode body protruding from the first cathode portion, and in the first direction, the boundary of the first side wall portion on the first anode terminal side is R, which is the width of the first cathode portion in the first direction. １ As such, 0.4R from the boundary on the first anode terminal side of the first cathode portion. １ The solid electrolytic capacitor according to claim 2 or 3, wherein the position is on the first anode terminal side rather than on the second anode terminal side.

11. The solid electrolytic capacitor according to claim 1, wherein the bottom portion has a plate-like portion that extends continuously in the first direction from the portion facing the first cathode portion toward the portion facing the second cathode portion, so as to face the entirety of the first cathode portion and the second cathode portion in the first direction.

12. The solid electrolytic capacitor according to claim 1, wherein the first cathode portion and the second cathode portion have the same shape, the capacitor element is configured such that a first element portion having the first cathode portion and the first anode portion and a second element portion having the second cathode portion and the second anode portion are connected via the separation portion, and the first element portion and the second element portion have the same structure.

13. The solid electrolytic capacitor according to claim 1, wherein the first anode portion, the separation portion, and the second anode portion of the anode body are integrally formed.

14. The solid electrolytic capacitor according to claim 1, which does not have an inductor member covering the separation portion.

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