Solid electrolytic capacitor

Abstract

This solid electrolytic capacitor comprises a laminate in which a plurality of capacitor elements are stacked in a second direction perpendicular to a first direction, each capacitor element having an anode body extending in a first direction and a cathode portion formed on the surface of the anode body with a dielectric layer interposed therebetween. The anode body has a cathode formation portion covered with the cathode portion, and a first anode lead-out portion and a second anode lead-out portion that are not covered with the cathode portion. The cathode formation portion is electrically connected to a first anode terminal via the first anode lead-out portion and to a second anode terminal via the second anode lead-out portion. When the number of stacked capacitor elements is N, the total width, in a direction perpendicular to the first direction, of the first anode lead-out portions of n1 capacitor elements (1 ≤ n1 ≤ N-1) from the side closer to a mounting portion in the laminate is shorter than the total width of the first anode lead-out portion of the capacitor element farthest from the mounting portion in the laminate.

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 a 100 MHz frequency band. These are known 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] Patent Document 1 proposes a surface-mount capacitor case characterized in that a single plate-shaped capacitor element having anodes at both ends and a cathode in the center, or a capacitor element stack formed by stacking multiple such capacitor elements, is inserted into a box-shaped molded resin case base formed on a lead frame on which terminals are formed by an insert molding method and which is open at the top, and a box-shaped case lid which is open at the bottom is enclosed, wherein a metal plate for supplementing the conductivity of the capacitor element cathode is locked to the inside of the case lid (Claim 2).

[0005] Patent Document 2 describes a capacitor element comprising a single capacitor element and a substrate on which the single capacitor element is mounted on one surface and for mounting on an electronic circuit board with two terminals, wherein the capacitor element has at least three anode portions formed in a part region of a valve metal substrate and a cathode portion formed by laminating a solid electrolyte layer and a conductive layer on the surface of the region of the valve metal substrate excluding each of the anode portions, the anode portions are formed on both sides of the cathode portion so as to sandwich it, and the one surface of the substrate has an anode wiring pattern having two anode fixing portions that extend parallel from one side to the other side of the substrate and are connected to the anode portions of the capacitor element, and a region sandwiched between the two anode fixing portions, and the A solid electrolytic capacitor is provided, characterized in that a cathode wiring pattern connected to the cathode portion of the electrolytic element is provided, and on the other side of the substrate, an anode terminal pattern connected to the anode wiring pattern via an anode through-hole penetrating the substrate and a cathode terminal pattern connected to the cathode wiring pattern via a cathode through-hole penetrating the substrate are provided, the anode wiring pattern further has a wiring connection portion connecting the two anode fixing portions, the anode through-hole is formed in the region of the anode wiring pattern including the wiring connection portion, and one anode terminal pattern and one cathode terminal pattern are provided on the other side of the substrate (Claim 1).

[0006] Patent No. 4889039 Specification Patent No. 4854945 Specification

[0007] Further improvements in noise filtering characteristics are desired for surface-mount capacitors.

[0008] Patent Document 1 describes a three-terminal solid electrolytic capacitor in which multiple capacitor elements, each having an anode lead portion with a width approximately equal to the width of the cathode portion, are stacked. However, it has been found that, depending on the configuration of the electrolytic capacitor, the advantages of stacking multiple capacitor elements may not be realized, especially in the high-frequency range, and the noise filter characteristics may deteriorate.

[0009] Patent Document 2 describes a configuration in which an anode terminal pattern and a cathode terminal pattern are provided on a substrate, and the anode portion (anode lead-out portion) is electrically connected to the anode terminal pattern. This configuration aims to reduce the equivalent series inductance while making it possible to apply the multi-terminal capacitor element to a different terminal type structure. However, the noise filter characteristics are not mentioned.

[0010] In this context, the present disclosure aims to improve the noise filter characteristics of a solid electrolytic capacitor in which multiple capacitor elements are stacked.

[0011] In view of the above, 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 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 which is electrically connected to the cathode portion, and an outer resin which covers the capacitor element, wherein the anode body has a cathode forming portion whose surface is covered with the cathode portion, a first anode extraction portion and a second anode extraction portion which are not covered with the cathode portion, and the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion. The laminate has a plurality of capacitor elements stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminals have a flat mounting portion that extends at least along the first direction and perpendicular to the second direction, the laminate is electrically connected to the mounting portion, and when the number of capacitor elements in the laminate is N, the total width or area of ​​the first anode lead portion in the direction perpendicular to the first direction of the n1 capacitor elements (1 ≤ n1 ≤ N-1) from the side closest to the mounting portion in the laminate is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion (n1+1) in the laminate.

[0012] In view of the above, another aspect of the present disclosure is 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 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 which is electrically connected to the cathode portion, and an outer resin which covers the capacitor element, wherein the anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion which are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, The present invention relates to a solid electrolytic capacitor having a laminate in which a plurality of capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminals have a flat mounting portion that extends at least along the first direction and perpendicular to the second direction, the laminate is electrically connected to the mounting portion, and when the number of capacitor elements in the laminate is N, the area of ​​the overlapping portion between the first anode lead portion of one of two adjacent capacitor elements (2 ≤ n2 ≤ N) in the laminate and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements.

[0013] In view of the foregoing, yet another aspect of the present disclosure 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 electrically connected to each other's independent 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 anode body has a cathode forming portion whose surface is covered by the cathode portion and a first anode extraction portion and a second anode extraction portion that are not covered by the cathode portion. The present invention relates to a solid electrolytic capacitor in which the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of capacitor elements are stacked in a laminate in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion extending along the first and second directions, and the sides of the laminate along the first and second directions are electrically connected to the mounting portion.

[0014] In view of the foregoing, yet another aspect of the present disclosure 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 anode body has a cathode forming portion whose surface is covered by the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered by the cathode portion, and the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion. The present invention relates to a solid electrolytic capacitor, wherein the capacitor is connected to a second anode and electrically connected to the second anode terminal via the second anode lead portion, and the plurality of capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction, the stack is electrically connected to the mounting portion, the length L of the cathode forming portion in the first direction is greater than twice the width W in the direction perpendicular to the first and second directions, and the plurality of stacks are arranged in a third direction that intersects the first direction and is perpendicular to the second direction.

[0015] According to this disclosure, the noise filter characteristics of a solid electrolytic capacitor having a laminate in which multiple capacitor elements are stacked can be improved.

[0016] Novel features of the present invention are described in the appended claims, but the present invention, both in terms of structure and content, and in conjunction with other objects and features of the present invention, will be better understood by the following detailed description in conjunction with the drawings.

[0017] A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 1, showing a cross-section along the line IA-IA in Figure 1C. A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 1, showing a cross-section along the line IB-IB in Figure 1C. A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 1, showing a cross-section along the line IIA-IIA or IIB-IIB in Figures 1A and 1B. A schematic side cross-sectional view of the capacitor element. A schematic perspective view of the laminate and cathode terminal of the capacitor element of Embodiment 1. A circuit diagram showing the equivalent circuit of the solid electrolytic capacitor of Embodiment 1. A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 2, showing a cross-section along the line IA-IA in Figures 5C and 5D. A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 2, showing a cross-section along the line IB-IB in Figures 5C and 5D. A schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 2, showing a cross-section along the line IIA-IIA in Figures 5A and 5B. This is a schematic cross-sectional view of the solid electrolytic capacitor of Embodiment 2, showing a cross-section along the line IIB-IIB in Figures 5A and 5B. This is a schematic perspective view of the laminate of capacitor elements and the cathode terminal in the solid electrolytic capacitor of Embodiment 3. This is a schematic perspective view of the laminate of capacitor elements and the cathode terminal in the solid electrolytic capacitor of Embodiment 4. This is a schematic perspective view of the laminate of capacitor elements and the cathode terminal in the solid electrolytic capacitor of Embodiment 5. This is a schematic perspective view of the laminate of capacitor elements and the cathode terminal in the solid electrolytic capacitor of Embodiment 5. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor. This is a graph showing the evaluation results of the pass characteristics of the solid electrolytic capacitor.

[0018] 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.

[0019] 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.

[0020] In the following explanation, the term "contains (or includes)" encompasses the expressions "contains (or includes)," "substantially consists of," and "consists of."

[0021] A solid electrolytic capacitor according to one embodiment of the present disclosure (hereinafter referred to as "the solid electrolytic capacitor according to this embodiment") can be used as a transmission line component, for example, a three-terminal type, which has a noise filter function. The solid electrolytic capacitor according to the present disclosure comprises a capacitor element, two anode terminals (a first anode terminal and a second anode terminal), a cathode terminal, and an outer resin. Note that there may be two or more anode terminals and one or more cathode terminals.

[0022] 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 ends are electrically connected to the anode terminals. One end of the anode body in the first direction is electrically connected to a first anode terminal, and the other end is electrically connected to a second anode terminal. The first and second anode terminals constitute two independent terminals. The cathode portion is electrically connected to the cathode terminals. The capacitor element may further have an insulating portion provided between the anode body and the cathode portion to electrically insulate them from each other. The insulating portion may be made of, for example, insulating tape or insulating resin.

[0023] The outer resin covers the capacitor element. 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 anode body has a cathode forming portion, the surface of which is covered by the cathode portion. In other words, the portion of the anode body facing the cathode portion is the cathode forming portion. The anode body further has a first anode extraction portion and a second anode extraction portion that are not covered by the cathode portion, and each of the first anode extraction portion and the second anode extraction portion protrudes from the cathode portion. The first anode extraction portion is continuous with the cathode forming portion and electrically connects the cathode forming portion and the first anode terminal. The second anode extraction portion is continuous with the cathode forming portion and electrically connects the cathode forming portion and the second anode terminal.

[0025] The solid electrolytic capacitor according to this embodiment comprises a plurality of capacitor elements. The plurality of capacitor elements are stacked in a second direction perpendicular to the first direction such that their cathode portions overlap, forming a laminate. As a result, the plurality of capacitor elements are connected in parallel, increasing the capacitance of the solid electrolytic capacitor and improving the noise filter characteristics. In particular, the noise rejection performance (pass characteristics) in the low frequency range (below 100 MHz) is improved.

[0026] The cathode terminal has a flat mounting portion extending along at least a first direction. The laminate is electrically connected to the main surface of the mounting portion. Electrical connection between the capacitor element and an external terminal of the solid electrolytic capacitor (that is, an exposed portion of the cathode terminal exposed from the exterior resin) is established via the mounting portion. The exposed portion of the cathode terminal that constitutes the external terminal may be formed continuously with the mounting portion, or may be formed as a separate member from the mounting portion. Normally, the main surface of the mounting portion is substantially parallel to the main surface (mounting surface) of an external substrate on which the solid electrolytic capacitor is mounted.

[0027] When the main surface of the mounting portion is perpendicular to the second direction, that is, when a plurality of capacitor elements are laminated in a direction perpendicular to the main surface of the mounting portion in the laminate, a difference occurs in the path length of a current path flowing between the capacitor elements from the anode terminal through the anode lead portion, through each individual capacitor element, to the cathode terminal. The path length passing through a capacitor element disposed close to the mounting portion inside the laminate is short, while the path length passing through a capacitor element disposed far from the mounting portion inside the laminate is long. As a result, the inductance component in the current path passing through the capacitor element disposed far from the mounting portion inside the laminate becomes larger than the inductance component in the current path passing through the capacitor element disposed close to the mounting portion inside the laminate.

[0028] As a result, a large amount of current preferentially flows through the capacitor elements disposed on the side of the mounting portion inside the laminate, and the current flowing through the capacitor elements disposed far from the mounting portion inside the laminate decreases. Consequently, particularly in a high-frequency region, the expected improvement effect of noise filter characteristics corresponding to an increase in the number of laminated capacitor elements cannot be obtained, and the effect of improving characteristics obtained by laminating a plurality of capacitor elements may be reduced.

[0029] In one embodiment, the solid electrolytic capacitor according to the present embodiment includes the following configuration 1. With configuration 1, the effect of improving characteristics achieved by increasing the number of laminated capacitor elements can be obtained efficiently, and noise filter characteristics are improved. Here, let N be the number of capacitor elements in the laminate (N≧2).

[0030] (Configuration 1) In n1 capacitor elements (1≦n1≦N−1) from the side closer to the mounting portion in the laminated body, the total width or area of the first anode lead portion in a direction perpendicular to the first direction is smaller than the total width or area of the first anode lead portion in the (n1+1)-th capacitor element from the mounting portion in the laminated body.

[0031] By reducing the total width of the first anode lead portion, or by reducing the area of the first anode lead portion, the inductance component of the first anode lead portion increases, and the inductance component in the current path passing through the capacitor element via the first anode lead portion and reaching the cathode terminal increases. Accordingly, the inductance component in the current path passing through the n1 capacitor elements on the side closer to the mounting portion increases, and the difference between the inductance component and the inductance component in the current path passing through the capacitor element located on the opposite side to the mounting portion in the laminated body decreases. As a result, current easily flows also to the (N−n1) capacitor elements on the side farther from the mounting portion, and current easily flows uniformly to all capacitor elements. Therefore, for all capacitor elements in the laminated body, the function as a noise filter can be effectively exhibited, and noise filter characteristics are improved.

[0032] It should be noted that cases are also conceivable, for example, where a plurality of first anode lead portions protrude from the cathode portion, or where the first anode lead portion protruding from the cathode portion branches and extends into a plurality of portions toward the first anode terminal and is electrically connected to the first anode terminal at a plurality of connection positions. In such a case, the total width of the first anode lead portions is the sum of the widths of the plurality of first anode lead portions at the location electrically connected to the first anode terminal.

[0033] The width or total width of the first anode lead portion may be the width or total width in a direction perpendicular to the first direction and intersecting the second direction, or may be the width or total width in a direction perpendicular to the first direction and parallel to the second direction.

[0034] If the anode body has a shape such as foil or plate material, which has two main surfaces and the dimension between the two main surfaces is sufficiently small compared to other dimensions, the width of the first anode lead-out in the direction parallel to the main surfaces and perpendicular to the first direction may be shortened, or the thickness between the main surfaces of the first anode lead-out may be made thin, in order to increase the inductance component of the first anode lead-out.

[0035] The area of ​​the first anode extraction portion refers to the projected area when the first anode extraction portion is projected onto a plane perpendicular to the stacking direction of the laminate. If multiple first anode extraction portions protrude or branch from the cathode portion, the area of ​​the first anode extraction portion is the sum of the projected areas of each individual first anode extraction portion.

[0036] In the above n1 capacitor elements, it is preferable that the total width or area of ​​the first anode lead portion in the direction perpendicular to the first direction is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion within the laminate.

[0037] When the laminate contains three or more capacitor elements (N≧3), it is preferable that the total width or area of ​​the first anode lead portion of the capacitor element closest to the mounting area within the laminate, and the first anode lead portion of the capacitor element second closest to the mounting area, is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting area within the laminate. In other words, it is preferable that the above configuration 1 is satisfied when N≧3 and at least n1=2. In this case, a sufficient improvement in noise filter characteristics can be obtained.

[0038] In the laminate, for n1 capacitor elements from the side closest to the mounting portion, the total width or area of ​​the first anode extraction portion in a direction perpendicular to the first direction may be smaller than the total width or area of ​​the first anode extraction portions in the remaining (N-n1) capacitor elements.

[0039] In one embodiment, the solid electrolytic capacitor according to this embodiment may include the following configuration 2. Configuration 2 also efficiently provides the effect of improving characteristics by increasing the number of stacked capacitor elements, thereby improving the noise filter characteristics.

[0040] (Configuration 2) Within a stack of n2 adjacent capacitor elements (2 ≤ n2 ≤ N), the area of ​​the overlap between the first anode lead of one of two adjacent capacitor elements in the stacking direction and the first anode lead of the other capacitor element, as viewed from the stacking direction, is 50% or less of the area of ​​the first anode lead of one of the capacitor elements.

[0041] By reducing the overlap in the stacking direction of the first anode leads between two adjacent capacitor elements within the laminate, the electromagnetic interaction between the first anode leads is reduced, and the inductance component of the first anode leads increases. As a result, the inductance component in the current path through the two adjacent capacitor elements increases, and the difference in inductance components in the current path through each capacitor element within the laminate becomes smaller. Consequently, all capacitor elements within the laminate can more effectively perform their function as noise filters, improving the noise filter characteristics.

[0042] In addition, the increase in inductance component makes it easier for current to flow evenly through all the capacitor elements within the laminate, thus reducing the ESR variation of a solid electrolytic capacitor with N capacitor elements connected in parallel to 1 / N.

[0043] The ratio of the overlapping area should be 50% or less, preferably 30% or less, 25% or less, 20% or less, or 10% or less, and it is most preferable that there is no overlapping area (area of ​​0%).

[0044] When two capacitor elements are arbitrarily selected from n2 adjacent capacitor elements (2 ≤ n2 ≤ N) within a laminate, the area of ​​the overlap between the first anode lead of one selected capacitor element and the first anode lead of the other selected capacitor element, as viewed from the lamination direction, may be 50% or less of the area of ​​the first anode lead of one selected capacitor element.

[0045] The above configuration 2 may be satisfied by a number of capacitor elements (N-1 or less) adjacent to each other within the laminate. That is, n2 ≤ N-1 is also acceptable.

[0046] The first anode lead-out portion of the capacitor element furthest from the mounting portion in the laminate may have an area overlap of more than 50% with the first anode lead-out portion of at least one capacitor element among the (N-1) capacitor elements in the laminate excluding the capacitor element furthest from the mounting portion.

[0047] In configuration 2, it is preferable that capacitor elements whose overlapping area is 50% or less are located on the side closer to the mounting area. That is, it is preferable that the solid electrolytic capacitor according to this embodiment satisfies the following configuration 2-1.

[0048] (Configuration 2-1) In n2 capacitor elements, starting from the side closest to the mounting section, the area of ​​the overlap between the first anode lead of one of two adjacent capacitor elements in the stacking direction and the first anode lead of the other capacitor element, as viewed from the stacking direction, is 50% or less of the area of ​​the first anode lead of one of the capacitor elements.

[0049] Configuration 2-1 also means that, conversely, among the (N-n2) capacitor elements from the side furthest from the mounting area, there may be a pair of adjacent capacitor elements where the overlap area with the first anode lead-out section, as viewed from the stacking direction, exceeds 50%. In this case, for the (N-n2) capacitor elements from the side furthest from the mounting area, the large overlap area reduces the inductance component of the first anode lead-out section. The inductance component in the current path passing through the (N-n2) capacitor elements on the side furthest from the mounting area decreases, and the difference between this and the inductance component in the current path passing through the n2 capacitor elements located on the mounting side becomes smaller. As a result, current flows more easily and evenly through all the capacitor elements, allowing all the capacitor elements in the stack to effectively perform their function as noise filters, and improving the noise filter characteristics.

[0050] When configuration 2-1 is satisfied, the area of ​​the overlap between the first anode extraction portion of the capacitor element closest to the mounting portion within the laminate and the first anode extraction portion of the capacitor element second closest to the mounting portion is 50% or less of the area of ​​the first anode extraction portion of the capacitor element closest to the mounting portion. Furthermore, it is preferable that the area of ​​the overlap between the first anode extraction portion of the capacitor element furthest from the mounting portion within the laminate and the first anode extraction portion of the capacitor element second furthest from the mounting portion is more than 50% of the area of ​​the first anode extraction portion of the capacitor element furthest from the mounting portion.

[0051] The solid electrolytic capacitor according to this embodiment may satisfy both configuration 1 and configuration 2 described above. In this case, the effect of improving the noise filter characteristics is significant.

[0052] In one embodiment, the solid electrolytic capacitor according to this embodiment may include the following configuration 3. Configuration 3 also efficiently provides the characteristic improvement effect of increasing the number of stacked capacitor elements, thereby improving the noise filter characteristics.

[0053] (Configuration 3) The cathode terminal has a flat mounting portion that extends in a first direction and in a second direction which is the stacking direction of the laminate, and the sides of the laminate along the first and second directions are electrically connected to the mounting portion. The above-mentioned sides of the laminate are substantially parallel to the mounting surface of the solid electrolytic capacitor to the external substrate.

[0054] In configuration 3, by electrically connecting the side of the laminate to the mounting section, the inductance component in the current path passing through each capacitor element within the laminate can be made approximately equal. As a result, current flows equally through all capacitor elements, allowing all capacitor elements within the laminate to effectively perform their function as noise filters, thereby improving the noise filter characteristics.

[0055] The solid electrolytic capacitor according to this embodiment may satisfy both configuration 2 and configuration 3 described above. In this case, the effect of improving the noise filter characteristics is significant.

[0056] In other words, in configuration 3, in two capacitor elements adjacent to each other in the stacking direction within the laminate, the area of ​​the overlapping portion between the first anode lead portion of one capacitor element and the first anode lead portion of the other capacitor element may be 50% or less of the area of ​​the first anode lead portion of one capacitor element. The area of ​​the overlapping portion is preferably 30% or less, 25% or less, 20% or less, or 10% or less, and it is most preferable that there is no overlapping portion (area is 0%).

[0057] The solid electrolytic capacitor according to this embodiment may include a first capacitor element and a second capacitor element, each having a different leading position of the first anode leading portion. In the first capacitor element, the first anode leading portion protrudes from the cathode forming portion toward the first anode terminal at a first position in a third direction that intersects the first direction and is perpendicular to the second direction. In the second capacitor element, the first anode leading portion protrudes from the cathode forming portion toward the first anode terminal at a second position different from the first position in the third direction.

[0058] By alternately stacking the first and second capacitor elements to form a laminate, the overlapping area between adjacent capacitor elements in the stacking direction can be reduced, making it easier to satisfy configuration 2. Furthermore, during the manufacturing of solid electrolytic capacitors, the fluidity of the outer resin is improved, making it easier to fill the spaces between the first and second anode leads with the outer resin, improving the airtightness of the package and enhancing reliability.

[0059] In this case, in the first capacitor element, the second anode lead portion may protrude from the cathode forming portion toward the second anode terminal at a second position in the third direction, and in the second capacitor element, the second anode lead portion may protrude from the cathode forming portion toward the second anode terminal at a first position in the third direction. In this case, the second capacitor element can be obtained by flipping the first capacitor element over in the stacking direction or rotating it by 180°, so there is no need to prepare the first capacitor element and the second capacitor element separately when manufacturing a solid electrolytic capacitor, and it becomes easier to manufacture a solid electrolytic capacitor with excellent noise filter characteristics.

[0060] The inductance component of the current path that flows from the anode terminal, through the anode lead-out portion, through each capacitor element in the multilayer body, and to the cathode terminal also depends on the inductance component of the capacitor element (that is, the inductance component of the cathode formation portion). When the inductance component of the capacitor element increases, a difference occurs in the path length of the current paths passing through the individual capacitor elements in the multilayer body (for example, depending on the distance between the mounting portion and the capacitor element), and even when a difference occurs in the inductance component resulting from the path length, the influence of this difference on noise filter characteristics can be reduced.

[0061] Let L be the inductance component of the path length passing through one capacitor element in the multilayer body Ａ and let L be the inductance component of the path length passing through another capacitor element in the multilayer body Ｂ . When L Ａ < L Ｂ , as described above, a larger amount of current preferentially flows through the capacitor element located in the path having the smaller inductance component L Ａ , and the current flowing through the capacitor element located in the path having the larger inductance component L Ｂ decreases. However, the difference in current flowing between capacitor elements caused by such a difference between L Ａ and L Ｂ depends on the ratio of the inductance components (L Ｂ / L Ａ ) rather than the difference between the inductance components (L Ｂ - L Ａ ). Therefore, by appropriately increasing the inductance component of the capacitor elements in the multilayer body, current can easily flow also to capacitor elements located in paths having a large inductance component L Ｂ , current can easily flow evenly to all capacitor elements, and all capacitor elements in the multilayer body can exhibit their function as noise filters.

[0062] In this regard, in order to appropriately increase the inductance component of the capacitor element, it is preferable that the length L in the first direction of the cathode formation portion of the capacitor element constituting the laminate is greater than twice the width W in the direction perpendicular to the first and second directions (L > 2W). Any of the above configurations 1, 2, and 3 may be combined with a capacitor element whose length L and width W satisfy the above relationship. Considering application to solid electrolytic capacitors with a size of several millimeters, from a manufacturing standpoint, it is preferable that the length L is 5 times or less the width W (L < 5W).

[0063] When capacitor elements whose length L and width W satisfy the above relationship are combined with the above configuration 1 (or configuration 2), which has a laminate in which capacitor elements are stacked in a direction perpendicular to the mounting portion, the shape of the laminate becomes elongated due to the small width W, and consequently the outer shape of the solid electrolytic capacitor also becomes elongated. A solid electrolytic capacitor may also be obtained by arranging multiple laminates in a third direction that intersects the first direction and is perpendicular to the second direction.

[0064] On the other hand, when a capacitor element whose length L and width W satisfy the above relationship is combined with the above configuration 3, the width W corresponds to the length of the laminate in the direction perpendicular to the mounting portion and defines the height of the solid electrolytic capacitor from the mounting surface. The height of the laminate in the stacking direction defines the width of the solid electrolytic capacitor when mounted. The stacking height H of the laminate may be made larger than the width W.

[0065] 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.

[0066] 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.

[0067] The 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, if necessary.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] The cathode terminal may have multiple protrusions projecting in the opposite direction to the anode. Each protrusion is electrically connected to the mounting portion, and at least a portion of the protruding surface of each protrusion is exposed from the outer resin. The multiple protrusions can each be electrically connected in parallel to external electrode terminals provided on the substrate. The protrusions may be formed by bending a plate-shaped cathode terminal. Multiple conductive members may be attached to the side of the cathode terminal opposite to the side on which the capacitor element is mounted, and these can also be used as protrusions.

[0073] The two anode terminals are electrically connected to the two leads of the anode body, respectively. In other words, one anode terminal (first anode terminal) is electrically connected to the end of the first anode lead, and the other anode terminal (second anode terminal) is electrically connected to the end of the second anode lead. In each capacitor element, the first anode lead and the second anode lead 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.

[0074] The first anode terminal and the second anode terminal are electrically connected to the first anode lead portion and the second anode lead portion of each of the plurality of capacitor elements. The anode terminals may be electrically connected to the ends of the anode lead portions by crimping or by welding (e.g., laser welding or resistance welding). The ends of the anode lead portions may be exposed from the outer resin and the exposed end faces of the anode lead portions may be electrically connected to the anode terminals.

[0075] The cathode terminal may be electrically connected to the cathode 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 parts.

[0076] In the solid electrolytic capacitor according to this disclosure, by connecting the first anode terminal to the high-frequency noise source side of the circuit board, a noise-free signal is output from the second anode terminal. In the solid electrolytic capacitor according to this disclosure, in configurations 1 and 2, the shape or arrangement of the first anode lead portion satisfies the above-mentioned conditions, but similarly, the shape or arrangement of the second anode lead portion may satisfy the above-mentioned conditions by replacing the first anode lead portion with the second anode lead portion. In that case, by connecting the second anode terminal to the high-frequency noise source side of the circuit board, a noise-free output is obtained from the first anode terminal.

[0077] Furthermore, when a standard two-terminal capacitor is connected between the signal line and ground (so-called shunt-through connection), the equivalent series inductance of the capacitor is sufficiently large, and the degradation of noise filter characteristics due to stacking in the high-frequency band, as described in this disclosure, is not a problem in the first place. Moreover, if the inductance component is increased using a structure similar to that of the present invention for the anode lead-out of a two-terminal capacitor, it leads to an increase in the equivalent series inductance of the entire capacitor, and the noise filter characteristics will actually worsen. As described above, this structure has special effects in three-terminal capacitors.

[0078] 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.

[0079] Embodiment 1 of the present disclosure will now be described. The solid electrolytic capacitor 10 of this embodiment comprises six capacitor elements 11 (11A to 11F), two anode terminals 17a and 17b, a cathode terminal 18, and an outer resin 19, as shown in Figures 1A to 3. In Figure 1, the side wall portion 18b, which will be described later, is shown by a dashed line.

[0080] Each capacitor element 11 (11A to 11F) has an anode 12 and a cathode 13 formed on the surface of the anode 12 via a dielectric layer 14.

[0081] The anode body 12 has a first anode extraction portion 12a, a cathode forming portion 12b, and a second anode extraction portion 12c. The cathode forming portion 12b is the portion of the anode body 12 that faces the cathode portion 13 via the dielectric layer 14. The first anode extraction portion 12a is the portion of the anode body 12 that protrudes from the cathode portion 13 in one direction of the first direction (left in Figure 1). The second anode extraction portion 12c is the portion of the anode body 12 that protrudes from the cathode portion 13 in the other direction of the first direction (right in Figure 1).

[0082] The anode body 12 extends in a first direction (left-right direction in Figure 1) from the first anode extraction section 12a, through the cathode forming section 12b, to the second anode extraction section 12c. The anode body 12 is composed of foil made of a valve-acting metal (aluminum in this example), but is not limited to this.

[0083] 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.

[0084] The cathode portion 13 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.

[0085] 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.

[0086] Insulating portions 15 may be provided between the cathode portion 13 and the first anode lead portion 12a, and between the cathode portion 13 and the second anode lead portion 12c, to electrically insulate them from each other.

[0087] The anode terminals 17a and 17b are electrically connected to the first anode lead-out portion 12a and the second anode lead-out portion 12c 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 anode lead-out portion 12a by crimping, and the anode terminal 17b may be electrically connected to the second anode lead-out portion 12c by crimping. Alternatively, or in addition to crimping, the anode terminal 17a may be welded to the first anode lead-out portion 12a, and the anode terminal 17b may be welded to the second anode lead-out portion 12c. Instead of crimping, the end faces of the first anode lead-out portion 12a and the second anode lead-out portion 12c may be exposed from the outer resin 19, and anode terminals 17a and 17b may be formed to cover the outer surface of the outer resin 19, including the exposed end faces.

[0088] The cathode terminal 18 is electrically connected to the cathode portion 13, 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.

[0089] The cathode terminal 18 has a mounting portion 18a and a side wall portion 18b. The side wall portion 18b rises continuously from the mounting portion 18a and is electrically connected to the sides of the cathode portions 13 of each capacitor element 11 (11A to 11F). The mounting portion 18a is electrically connected to the cathode portion of capacitor element 11A on its upper surface, while at least a portion of its lower surface is exposed from the exterior resin 19. The side wall portion 18b may be electrically connected to the sides of the cathode portion 13 via a conductive adhesive (not shown). The first side wall portion 18b may be provided on both sides of the side surface of the cathode portion 13a.

[0090] 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.

[0091] In the solid electrolytic capacitor 10, multiple capacitor elements 11A to 11F are stacked in a second direction perpendicular to the first direction (the vertical direction in Figures 1A and 1B) to form a laminate. In the example of Figures 1A and 1B, the second direction is perpendicular to the mounting surface of the solid electrolytic capacitor and perpendicular to the mounting portion 18a, but it is not limited to this. The number of capacitor elements stacked in the laminate is also not particularly limited.

[0092] As described below, the capacitor elements 11A to 11F differ in shape and arrangement when viewed from the stacking direction of the first anode lead portion 12a and the second anode lead portion 12c. Other configurations are common to the capacitor elements 11A to 11F. The capacitor elements 11A to 11F are stacked in the second direction such that their cathode portions 13 overlap, forming a laminate.

[0093] In the stacking direction, adjacent cathode portions 13 are electrically connected to each other via the conductive paste 16. Therefore, all cathode portions 13 are electrically connected to each other. The cathode portion 13 of the capacitor element 11A, which is stacked in the lowest layer of the stack, is electrically connected to the mounting portion 18a.

[0094] In the stacking direction, adjacent anode bodies 12 are electrically connected to each other by the first anode lead portion 12a of each capacitor element being electrically connected to the anode terminal 17a, and the second anode lead portion 12c of each capacitor element being electrically connected to the anode terminal 17b. Thus, all anode bodies 12 are electrically connected to each other.

[0095] In the capacitor elements 11E and 11F, which are located far above the mounting section 18a, the width of the first anode lead-out section 12a and the second anode lead-out section 12c (the width in the third direction perpendicular to the first and second directions) is about the same width as the width of the outer resin. In contrast, in the capacitor elements 11A to 11D, which are located closer to the mounting section 18a, the width of the first anode lead-out section 12a and the second anode lead-out section 12c is narrower than that of the capacitor elements 11E and 11F.

[0096] In capacitor elements 11A and 11C, two first anode leads 12a and two second anode leads 12c are provided at both ends in the third direction. In contrast, in capacitor elements 11B and 11D, one first anode lead 12a and one second anode lead 12c are provided at the center in the third direction. In capacitor elements 11A and 11C, the total width obtained by summing the widths of the two first anode leads 12a in the third direction is approximately the same as the width (total width) of the first anode lead 12a in the third direction in capacitor elements 11B and 11D.

[0097] Capacitor elements 11A and 11C are identical capacitor elements (first capacitor elements). Capacitor elements 11B and 11D are identical capacitor elements (second capacitor elements). Capacitor elements 11B and 11D differ from capacitor elements 11A and 11C in the position of the first anode lead portion 12a and the second anode lead portion 12c protruding from the cathode portion in the third direction. In the lower capacitor elements 11A to 11D, the first capacitor elements and the second capacitor elements are stacked alternately.

[0098] In capacitor elements 11A to 11D, the total width of the first anode lead portion 12a in the third direction perpendicular to the first direction is shorter than the total width of the first anode lead portion 12a in capacitor elements 11E and 11F, satisfying configuration 1 when n1 ≤ 4. Also, in capacitor elements 11A to 11D, the area of ​​the overlapping portion of the first anode lead portion 12a between two adjacent capacitor elements is 50% or less of the area of ​​one of the first anode lead portions 12a, and there is no overlapping portion, satisfying configuration 2 when n2 ≤ 4.

[0099] The equivalent circuit of the solid electrolytic capacitor 10 is shown in Figure 4. In Figure 4, the inductance generated by the first anode lead portion 12a is L. １１ ~L １６ Then, the inductance generated by the second anode extraction section 12c is L ２１ ~L ２６ This is shown by L. ４ L is the inductance generated by the mounting portion 18a. １１ ~L １６ , L ２１ ~L ２６ This partially includes an inductance component due to the capacitor elements 11A to 11F.

[0100] We compare the current path R1, which flows from the anode terminal 17a to the anode terminal 17b via the lowest layer capacitor element 11A, and the current path R2, which flows from the anode terminal 17a to the anode terminal 17b via the uppermost layer capacitor element 11F. １１ ~L １６ Assuming they are the same, the inductance in the current path R2 is the inductance L due to the side wall portion 18b and the cathode portion 13. ３１ ~L ３５ This amount makes the inductance greater than that in the current path R1. Also, since the current flows over a longer distance within the anode terminals 17a and 17b in the current path R2, the inductance component due to the anode terminals 17a and 17b is greater than that in the current path R1, and the inductance in the current path R2 is greater than that in the current path R1. As a result, the current flowing through the uppermost capacitor element 11F decreases, while the current flowing through the lowermost capacitor element 11A increases, and it is possible that the higher up the capacitor element is located, the smaller its contribution to noise reduction becomes.

[0101] In contrast, in the solid electrolytic capacitor 10, by shortening the total width in the third direction perpendicular to the first direction of the first anode lead portion 12a in the capacitor elements 11A to 11D, and by reducing the overlap of the first anode lead portions 12a between adjacent capacitor elements, L １１ ~L １４ However, L １５ , L １６It has become larger than this. As a result, L in the current path R2 ３１ ~L ３５ The increase in inductance due to this is reflected in the current path R1. １１ to L １６ By making it larger, the difference in inductance between the current paths R1 and R2 is reduced, making it easier for current to flow to the uppermost capacitor element 11F. As a result, not only the capacitor elements located in the lower layers but also the capacitor elements located in the upper layers can effectively perform their function as noise filters, improving the noise filter characteristics.

[0102] <Embodiment 2> Embodiment 2 of the present disclosure will now be described. The solid electrolytic capacitor 10A of this embodiment differs from Embodiment 1 in the configuration of the first anode lead portion 12a and the second anode lead portion 12c in the capacitor elements 11A to 11D. The differences from Embodiment 1 will be mainly described below. As shown in Figures 5A to 5D, the solid electrolytic capacitor 10A comprises six capacitor elements 11 (11A to 11F), two anode terminals 17a and 17b, a cathode terminal 18, and an outer resin 19.

[0103] In capacitor elements 11A and 11C, two first anode leads 12a are provided at both ends in the third direction. In contrast, in capacitor elements 11B and 11D, one first anode lead 12a is provided at the center in the third direction. In capacitor elements 11A and 11C, the total width obtained by summing the widths of the two first anode leads 12a in the third direction is approximately the same as the width (total width) of the first anode lead 12a in the third direction in capacitor elements 11B and 11D.

[0104] In capacitor elements 11B and 11D, two second anode leads 12c are provided at both ends in the third direction. In contrast, in capacitor elements 11A and 11C, one second anode lead 12c is provided at the center in the third direction. In capacitor elements 11B and 11D, the total width obtained by summing the widths of the two second anode leads 12c in the third direction is approximately the same as the width (total width) of the second anode lead 12c in the third direction in capacitor elements 11A and 11C.

[0105] In other words, capacitor elements 11A and 11C are identical capacitor elements (first capacitor elements). Capacitor elements 11B and 11D are identical capacitor elements (second capacitor elements). Capacitor elements 11B and 11D are obtained by rotating capacitor elements 11A and 11C by 180° around the stacking direction (second direction) or by flipping them over (rotating them by 180° around the direction perpendicular to the plane of the paper in Figure 1A). In the lower layer capacitor elements 11A to 11D, the first capacitor elements and the second capacitor elements are stacked alternately.

[0106] Similar to Embodiment 1, in capacitor elements 11A to 11D, the total width of the first anode lead portion 12a in the third direction perpendicular to the first direction is shorter than the total width of the first anode lead portion 12a in capacitor elements 11E and 11F, satisfying Configuration 1 when n1 ≤ 4. Furthermore, in capacitor elements 11A to 11D, the area of ​​the overlapping portion of the first anode lead portion 12a between two adjacent capacitor elements is 50% or less of the area of ​​one of the first anode lead portions 12a, and there is no overlapping portion, satisfying Configuration 2 when n2 ≤ 4.

[0107] <Embodiment 3> Embodiment 2 of the present disclosure will now be described. The solid electrolytic capacitor 10B of this embodiment differs from Embodiment 1 in the configuration of the first anode lead portion 12a and the second anode lead portion 12c in the capacitor elements 11A to 11D. The differences from Embodiment 1 will be mainly described below.

[0108] In the solid electrolytic capacitor 10B shown in Figure 6, the first anode leads 12a of the capacitor elements 11A to 11D are arranged so that they do not overlap with each other when viewed from the stacking direction, and protrude toward the anode terminal 17a. The second anode leads 12c of the capacitor elements 11A to 11D each protrude toward the anode terminal 17b at the same third-direction position as the corresponding first anode leads 12a.

[0109] The solid electrolytic capacitor 10B satisfies configuration 1 above when n1 ≤ 4. It also satisfies configuration 2 above when n2 ≤ 4. Furthermore, when two capacitor elements are arbitrarily selected from capacitor elements 11A to 11D, there is no overlapping portion between the first anode lead portion 12a of one selected capacitor element and the first anode lead portion 12a of the other selected capacitor element, and the area ratio of the overlapping portion is 50% or less.

[0110] Embodiment 4 Embodiment 4 of the present disclosure will now be described. The solid electrolytic capacitor 10C of this embodiment differs in the method of mounting it on the mounting portion 18a of the laminated body in which the capacitor elements are stacked. The differences from Embodiment 1 described above will be explained below.

[0111] In the solid electrolytic capacitor 10C shown in Figure 7, the mounting portion 18a extends along a first direction and also along a second direction, which is the stacking direction of the laminate. The side surface perpendicular to the stacking direction of the laminate is electrically connected to the mounting portion 18a. The mounting surface on the mounting portion 18a of the laminate is substantially parallel to the mounting surface on which the solid electrolytic capacitor 10C is mounted on the external substrate. Note that the conductive paste 16 is omitted from Figure 7 (and Figures 8A and 8B described later).

[0112] In the laminate, capacitor elements 11G and 11H are stacked alternately. Capacitor element 11G has the same configuration as capacitor element 11A in Embodiment 1. Capacitor element 11H has the same configuration as capacitor element 11B in Embodiment 1. For all capacitor elements in the laminate, the area of ​​the overlapping portion, as viewed from the stacking direction, between the first anode lead portion 12a of one of two adjacent capacitor elements in the stacking direction (capacitor element 11G) and the first anode lead portion 12a of the other capacitor element (capacitor element 11H) is 50% or less of the area of ​​the first anode lead portion 12a of one of the capacitor elements.

[0113] In the capacitor elements 11G and 11H, the length L of the cathode forming portion 12b (or cathode portion 13) in the first direction is greater than twice the width W in the direction perpendicular to the first and second directions (L > 2W). The width W corresponds to the length of the stack in the direction perpendicular to the mounting portion. The length of the stack in the stacking direction (stack height H) defines the width of the solid electrolytic capacitor when mounted. The stack height H may be greater than the width W (H > W).

[0114] Embodiment 5 Embodiment 5 of the present disclosure will now be described. The solid electrolytic capacitor 10D of this embodiment comprises a laminate of multiple capacitor elements. The differences from Embodiment 1 described above will be explained below.

[0115] In the solid electrolytic capacitor 10D shown in Figure 8A, multiple capacitor elements 11I are stacked in a second direction perpendicular to the first direction (the up and down direction in Figure 8A), forming a laminate. Multiple (two in the illustrated example) laminates are arranged in a third direction that intersects the first direction and is perpendicular to the second direction, and are placed on the mounting section 18a.

[0116] In the capacitor element 11I, the length L of the cathode forming portion 12b (or cathode portion 13) in the first direction is greater than twice the width W in the direction perpendicular to the first and second directions (L > 2W).

[0117] As shown in Figure 8B, the solid electrolytic capacitor 10E, in Figure 8A, capacitor elements 11J and 11K with different arrangements of the first anode lead portion 12a and the second anode lead portion 12c may be stacked alternately to form a laminate. In capacitor elements 11J and 11K adjacent to each other in the stacking direction, the area of ​​the overlapping portion of the first anode lead portion 12a as viewed from the stacking direction is 50% or less of the area of ​​the first anode lead portion 12a of capacitor element 11J or capacitor element 11K, and there is no overlapping portion.

[0118] [Note] The above description of embodiments discloses the following technologies. (Technical 1) 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, 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 anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction and is perpendicular to the second direction, and the stack is electrically connected to the mounting portion. A solid electrolytic capacitor in which, when the number of capacitor elements in the laminate is N, the total width or area of ​​the first anode lead portion in the direction perpendicular to the first direction of the n1 capacitor elements (1 ≤ n1 ≤ N-1) from the side closest to the mounting portion in the laminate is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion (n1+1) in the laminate. (Technical 2) The solid electrolytic capacitor according to Technical 1, wherein, in the n1 capacitor elements, the total width or area of ​​the first anode lead portion in the direction perpendicular to the first direction is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion in the laminate.(Technology 3) A solid electrolytic capacitor according to Technology 1 or 2, wherein the laminate has three or more capacitor elements, and the total width or area of ​​the first anode lead portion of the capacitor element closest to the mounting portion within the laminate, and the first anode lead portion of the capacitor element second closest to the mounting portion are smaller than the total width or area of ​​the first anode lead portion of the capacitor element third closest to the mounting portion within the laminate. (Technology 4) A solid electrolytic capacitor according to any one of Technology 1 to 3, wherein, within the n2 capacitor elements (2 ≤ n2 ≤ N) from the side closest to the mounting portion within the laminate, the area of ​​the overlapping portion between the first anode lead portion of one of two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements.(Technical 5) 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, 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 anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction and is perpendicular to the second direction, and the stack is electrically connected to the mounting portion. A solid electrolytic capacitor in which, when the number of capacitor elements in the laminate is N, the area of ​​the overlap between the first anode lead portion of one of two adjacent capacitor elements (2 ≤ n2 ≤ N) in the laminate and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements. (Technical 6) The solid electrolytic capacitor according to Technical 5, wherein n2 ≤ N-1. (Technical 7) The solid electrolytic capacitor according to Technical 5 or 6, wherein the first anode lead portion of the capacitor element furthest from the mounting portion in the laminate has an area overlap of more than 50% with the first anode lead portion of at least one of the (N-1) capacitor elements in the laminate excluding the capacitor element furthest from the mounting portion.(Technical 8) A solid electrolytic capacitor according to any one of Technical 5 to 7, wherein the plurality of capacitor elements comprises a first capacitor element and a second capacitor element, and in the first capacitor element, the first anode lead portion protrudes from the cathode forming portion toward the first anode terminal at a first position in a third direction intersecting the first direction and perpendicular to the second direction, the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at a second position different from the first position in the third direction, and in the second capacitor element, the first anode lead portion protrudes from the cathode forming portion toward the first anode terminal at a second position in the third direction, and the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at a first position in the third direction, and the first capacitor elements and the second capacitor elements are alternately stacked in the laminate. (Technology 9) A solid electrolytic capacitor according to any one of Techniques 4 to 7, wherein, within the n2 capacitor elements, there is no overlapping portion between the first anode lead portion of one of two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element. (Technology 10) A solid electrolytic capacitor according to any one of Techniques 4 to 7, wherein, within the n2 stacked bodies, starting from the side closest to the mounting portion, the area of ​​the overlapping portion between the first anode lead portion of one of two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements. (Technology 11) A solid electrolytic capacitor according to Technique 10, wherein, within the n2 capacitor elements, there is no overlapping portion between the first anode lead portion of one of two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element.(Technical 12) 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, 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 anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other. A solid electrolytic capacitor wherein the cathode terminal has a flat mounting portion extending along the first and second directions, and the sides of the laminate along the first and second directions are electrically connected to the mounting portion. (Technical 13) A solid electrolytic capacitor according to Technical 12, wherein in two capacitor elements adjacent to each other in the stacking direction within the laminate, the area of ​​the overlapping portion between the first anode lead portion of one of the capacitor elements and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements. (Technical 14) A solid electrolytic capacitor according to any one of Technical 1 to 13, wherein the plurality of capacitor elements comprises a first capacitor element and a second capacitor element, the first anode lead portion of the first capacitor element protrudes from the cathode forming portion toward the first anode terminal at a first position in a third direction intersecting the first direction and perpendicular to the second direction, the second capacitor element protrudes from the cathode forming portion toward the first anode terminal at a second position different from the first position in the third direction, and the first capacitor elements and the second capacitor elements are alternately stacked in the laminate.(Technical 15) The solid electrolytic capacitor according to Technical 14, wherein in the first capacitor element, the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at the second position in the third direction, and in the second capacitor element, the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at the first position in the third direction. (Technical 16) The solid electrolytic capacitor according to any one of Technical 1 to 11, wherein in the capacitor element constituting the laminate, the length L of the cathode forming portion in the first direction is greater than twice the width W in the direction perpendicular to the first and second directions. (Technical 17) The solid electrolytic capacitor according to Technical 16, wherein a plurality of the laminates are arranged in a third direction that intersects the first direction and is perpendicular to the second direction. (Technical 18) The solid electrolytic capacitor according to Technical 12 or 13, wherein the capacitor element constituting the laminate is wherein the length L in the first direction of the cathode forming portion is greater than twice the width W in the direction perpendicular to the first and second directions. (Technical 19) The solid electrolytic capacitor according to Technical 18, wherein the stacking height of the laminate is greater than the width W.(Technical 20) 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, 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 anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction, and the stack is electrically connected to the mounting portion. A solid electrolytic capacitor in which the length L in the first direction of the cathode forming portion is greater than twice the width W in the direction perpendicular to the first and second directions, and a plurality of the laminates are arranged in a third direction that intersects the first direction and is perpendicular to the second direction.

[0119] The following shows the results of characteristic evaluations performed on the solid electrolytic capacitors listed below.

[0120] 《Evaluation Example 1》 Solid electrolytic capacitors Z1 to Z3 were designed by stacking the capacitor element 11F shown in Figures 1A to 1C and Figure 3 in one, three, or six layers, while the rest of the solid electrolytic capacitors Z1 to Z3 were the same as the solid electrolytic capacitor 10 of Embodiment 1. The dimensions of the cathode formation portion of the capacitor element were set to a width of 4.4 mm in the first direction and a width of 3.7 mm in the third direction. The transmission characteristics of solid electrolytic capacitors Z1 to Z3 were evaluated by electromagnetic field analysis based on the physical shape and material parameters of the capacitors. The transmission characteristics refer to the S21 characteristics of the S-parameter characteristics in a 50Ω characteristic impedance system with anode terminals 17a and 17b as input and output, respectively.

[0121] The evaluation results are shown in Figure 9. As shown in the figure, in the frequency range of 5 to 100 MHz, increasing the number of layers from 3 to 6 did not improve noise reduction performance; in fact, it was found that the noise reduction performance deteriorated. The reason for this is thought to be that, due to the difference in the magnitude of the inductance component in the current path through each capacitor element, current does not easily flow to the capacitor elements located in the upper layers of the laminate, and the capacitor elements located in the upper layers are unable to perform their noise filtering function.

[0122] <Evaluation Example 2> A solid electrolytic capacitor Y1 was designed by stacking four layers of the capacitor element 11F shown in Figures 1A to 1C and Figure 3, and otherwise being the same as the solid electrolytic capacitor 10 of Embodiment 1.

[0123] A solid electrolytic capacitor X1 was designed using a laminate in which three layers of capacitor elements 11F are stacked on top of the capacitor element 11A shown in Figures 1A to 1C and Figure 3, and otherwise the same as the solid electrolytic capacitor 10 of Embodiment 1.

[0124] Furthermore, a laminate was constructed by sequentially stacking the capacitor elements 11A and 11B shown in Figures 1A to 1C and Figure 3, and then stacking two layers of capacitor element 11F on top of them. Using this laminate, a solid electrolytic capacitor X2 was designed, which is otherwise the same as the solid electrolytic capacitor 10 of Embodiment 1. The solid electrolytic capacitor X1 satisfies the above configuration 1 (n1=1). The solid electrolytic capacitor X2 satisfies the above configurations 1 and 2 (n1=2, n2=2).

[0125] The pass-through characteristics of solid electrolytic capacitors Y1, X1, and X2 were evaluated by electromagnetic field analysis. The evaluation results are shown in Figure 10. As shown in Figure 10, solid electrolytic capacitors X1 and X2 showed improved noise reduction performance compared to solid electrolytic capacitor Y1 in the frequency range of 10 to 200 MHz.

[0126] <Evaluation Example 3> As shown in Figures 1A to 1C and Figure 3, a laminate was constructed by alternately stacking capacitor elements 11A, which have first anode lead sections and second anode lead sections at both ends in the third direction, and capacitor elements 11B, which have first anode lead sections and second anode lead sections at the center in the third direction. The number of layers of capacitor elements in the laminate was 6.

[0127] By changing the width of the first and second anode lead sections in the third direction, the area of ​​the overlapping portion of the first anode lead section between adjacent capacitor elements and the area of ​​the overlapping portion of the second anode lead section between adjacent capacitor elements were changed. Solid electrolytic capacitors Y2 to Y6 were designed with overlapping area ratios of 0%, 25%, 50%, 75%, and 100%, respectively.

[0128] The transmission characteristics of solid electrolytic capacitors Y2 to Y6 were evaluated by electromagnetic field analysis. The evaluation results are shown in Figure 11.

[0129] <Evaluation Example 4> Solid electrolytic capacitors X3 and X4 similar to the solid electrolytic capacitor 10C shown in Figure 7 were designed and compared with the solid electrolytic capacitor Z3 in which six layers of capacitor elements 11F are stacked. In solid electrolytic capacitors X3 and X4, there are no overlapping portions between the first anode leads of adjacent capacitor elements, and between the second anode leads of adjacent capacitor elements.

[0130] In solid electrolytic capacitor X3, the length L in the first direction of the cathode formation portion 12b was set to 4.4 mm and the width W to 3.3 mm (L / W = 1.33), and six layers of capacitor elements were stacked. The stacking height H was set to 1.2 mm. In solid electrolytic capacitor X4, the length L in the first direction of the cathode formation portion 12b was set to 4.4 mm and the width W to 1.1 mm (L / W = 4), and eighteen layers of capacitor elements were stacked. The stacking height H was set to 3.6 mm. The evaluation results from electromagnetic field analysis are shown in Figure 12. Compared with Z3 using conventional technology, X3 with a structure satisfying configuration 3 showed improved noise reduction performance in the frequency range of 10 to 1000 MHz. Similar improvements were also observed in X4, which has approximately the same external shape as Z3 and satisfies configuration 3.

[0131] <Evaluation Example 5> The capacitor element 11F shown in Figures 1A to 1C and Figure 3 was stacked in one, three, or six layers, and the solid electrolytic capacitors Z4 to Z6 were otherwise configured in the same way as the solid electrolytic capacitor 10 of Embodiment 1. The length L of the cathode formation portion 12b in the first direction was set to 2.5 mm and the width W to 10 mm (L / W = 0.25). The transmission characteristics of the solid electrolytic capacitors Z4 to Z6 were evaluated by electromagnetic field analysis.

[0132] Similarly, the length L of the cathode forming portion 12b in the first direction was changed to 5 mm and the width W to 5 mm (L / W = 1.0), and the capacitor element 11F was stacked in one layer, three layers, or six layers, while the solid electrolytic capacitors Z7 to Z9 were otherwise configured in the same way as the solid electrolytic capacitor 10 of Embodiment 1. The transmission characteristics of the solid electrolytic capacitors Z7 to Z10 were evaluated by electromagnetic field analysis.

[0133] Similarly, the length L of the cathode forming portion 12b in the first direction was changed to 7 mm and the width W to 3.5 mm (L / W = 2.0), and the capacitor element 11F was stacked in one layer, three layers, or six layers, while the solid electrolytic capacitors Z10 to Z12 were otherwise configured in the same way as the solid electrolytic capacitor 10 of Embodiment 1. The transmission characteristics of the solid electrolytic capacitors Z10 to Z12 were evaluated by electromagnetic field analysis.

[0134] Similarly, the length L of the cathode forming portion 12b in the first direction was changed to 10 mm and the width W to 2.5 mm (L / W = 4.0), and the capacitor element 11F was stacked in one layer, three layers, or six layers, while the solid electrolytic capacitors Z13 to Z15 were otherwise configured in the same way as the solid electrolytic capacitor 10 of Embodiment 1. The transmission characteristics of the solid electrolytic capacitors Z13 to Z15 were evaluated by electromagnetic field analysis.

[0135] The evaluation results are shown in Figures 13A to 13D. The larger the L / W ratio, the better the attenuation characteristics in the high-frequency range, and the less the performance degradation during lamination. By setting L / W to 2 or higher, the attenuation characteristics in the high-frequency range can be improved, and the performance degradation during lamination in the 10-100 MHz range (especially near 100 MHz) can be reduced.

[0136] This disclosure can be used in solid electrolytic capacitors.

[0137] 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.

[0138] 10: Solid electrolytic capacitor 11: Capacitor element 12: Anode body 12a: First anode lead-out section 12c: Second anode lead-out section 12b: Cathode forming section 13: Cathode section 14: Dielectric layer 15: Insulating section 16: Conductive paste 17: Anode terminal 18: Cathode terminal 18a: Mounting section 18b: Side wall section 19: Outer resin

Claims

1. 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, 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 anode body has a cathode forming portion whose surface is covered with the cathode portion, and a first anode extraction portion and a second anode extraction portion that are not covered with the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a laminate in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction and perpendicular to the second direction, and the laminate is electrically connected to the mounting portion. A solid electrolytic capacitor in which, when the number of capacitor elements in the laminate is N, the total width or area of ​​the first anode lead portion in the n1 capacitor elements (1 ≤ n1 ≤ N-1) from the side closest to the mounting portion in the laminate is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion (n1+1) in the laminate.

2. The solid electrolytic capacitor according to claim 1, wherein in the n1 capacitor elements, the total width or area of ​​the first anode lead portion in a direction perpendicular to the first direction is smaller than the total width or area of ​​the first anode lead portion of the capacitor element furthest from the mounting portion within the laminate.

3. The solid electrolytic capacitor according to claim 1, wherein the laminate has three or more capacitor elements, and the total width or area of ​​the first anode lead portion of the capacitor element closest to the mounting portion within the laminate, and the first anode lead portion of the capacitor element second closest to the mounting portion, is smaller than the total width or area of ​​the first anode lead portion of the capacitor element third closest to the mounting portion within the laminate.

4. In the laminate, among n2 capacitor elements (2 ≤ n2 ≤ N) from the side closest to the mounting portion, the area of ​​the overlapping portion between the first anode lead portion of one of two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements, according to claim 1.

5. 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, each 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 anode body has a cathode forming portion whose surface is covered by the cathode portion, and a first anode extraction portion and a second anode extraction portion not covered by the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion that extends at least along the first direction and perpendicular to the second direction, and the stack is electrically connected to the mounting portion. A solid electrolytic capacitor in which, when the number of capacitor elements in the laminate is N, the area of ​​the overlapping portion between the first anode lead portion of one of two adjacent capacitor elements (2 ≤ n2 ≤ N) in the laminate and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements.

6. The solid electrolytic capacitor according to claim 5, wherein n² ≤ N-1.

7. The solid electrolytic capacitor according to claim 5, wherein the first anode lead of the capacitor element furthest from the mounting portion in the laminate has an area overlap of more than 50% with the first anode lead of at least one of the (N-1) capacitor elements in the laminate, excluding the capacitor element furthest from the mounting portion.

8. The solid electrolytic capacitor according to claim 5, wherein the plurality of capacitor elements comprises a first capacitor element and a second capacitor element, and in the first capacitor element, the first anode lead portion protrudes from the cathode forming portion toward the first anode terminal at a first position in a third direction intersecting the first direction and perpendicular to the second direction, the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at a second position different from the first position in the third direction, and in the second capacitor element, the first anode lead portion protrudes from the cathode forming portion toward the first anode terminal at a second position in the third direction, and the second anode lead portion protrudes from the cathode forming portion toward the second anode terminal at a first position in the third direction, and the first capacitor elements and the second capacitor elements are alternately stacked in the laminate.

9. A solid electrolytic capacitor according to any one of claims 4 to 7, wherein, among the n2 capacitor elements, there is no overlapping portion between the first anode lead portion of one of the two capacitor elements adjacent in the stacking direction and the first anode lead portion of the other capacitor element.

10. A solid electrolytic capacitor according to any one of claims 4 to 7, wherein, within the n2 capacitor elements, from the side closest to the mounting portion, the area of ​​the overlapping portion between the first anode lead portion of one of the two adjacent capacitor elements in the stacking direction and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one of the capacitor elements.

11. The solid electrolytic capacitor according to claim 10, wherein, among the n2 capacitor elements, there is no overlapping portion between the first anode lead portion of one of the two capacitor elements adjacent in the stacking direction and the first anode lead portion of the other capacitor element.

12. 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, each 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 anode body has a cathode forming portion whose surface is covered by the cathode portion, and a first anode extraction portion and a second anode extraction portion not covered by the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion and to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other. The cathode terminal has a flat mounting portion extending along the first and second directions, and the sides of the laminate along the first and second directions are electrically connected to the mounting portion, in a solid electrolytic capacitor.

13. The solid electrolytic capacitor according to claim 12, wherein, in two capacitor elements adjacent to each other in the stacking direction within the stacked body, the area of ​​the overlapping portion between the first anode lead portion of one capacitor element and the first anode lead portion of the other capacitor element is 50% or less of the area of ​​the first anode lead portion of one capacitor element.

14. A solid electrolytic capacitor according to any one of claims 1, 5, and 12, wherein the plurality of capacitor elements comprises a first capacitor element and a second capacitor element, the first capacitor element having a first anode lead-out portion that protrudes from the cathode forming portion toward the first anode terminal at a first position in a third direction intersecting the first direction and perpendicular to the second direction, the second capacitor element having a first anode lead-out portion that protrudes from the cathode forming portion toward the first anode terminal at a second position different from the first position in the third direction, and the laminate having the first capacitor elements and the second capacitor elements stacked alternately.

15. The solid electrolytic capacitor according to claim 14, wherein in the first capacitor element, the second anode lead portion protrudes toward the second anode terminal from the cathode forming portion at the second position in the third direction, and in the second capacitor element, the second anode lead portion protrudes toward the second anode terminal from the cathode forming portion at the first position in the third direction.

16. The solid electrolytic capacitor according to claim 1 or 5, wherein the capacitor element constituting the laminate has a length L in the first direction of the cathode forming portion that is greater than twice the width W in the direction perpendicular to the first and second directions.

17. The solid electrolytic capacitor according to claim 16, wherein a plurality of the laminates are arranged in a third direction that intersects the first direction and is perpendicular to the second direction.

18. The solid electrolytic capacitor according to claim 12 or 13, wherein the capacitor element constituting the laminate is such that the length L in the first direction of the cathode forming portion is greater than twice the width W in the direction perpendicular to the first and second directions.

19. The solid electrolytic capacitor according to claim 18, wherein the stacking height of the laminate is greater than the width W.

20. 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, each 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 anode body has a cathode forming portion whose surface is covered by the cathode portion, and a first anode extraction portion and a second anode extraction portion not covered by the cathode portion, the cathode forming portion is electrically connected to the first anode terminal via the first anode extraction portion, and is electrically connected to the second anode terminal via the second anode extraction portion, and a plurality of the capacitor elements are stacked in a second direction perpendicular to the first direction such that the cathode portions overlap each other, the cathode terminal has a flat mounting portion extending at least along the first direction, and the stack is electrically connected to the mounting portion. A solid electrolytic capacitor in which the length L in the first direction of the cathode forming portion is greater than twice the width W in the direction perpendicular to the first and second directions, and a plurality of the laminates are arranged in a third direction that intersects the first direction and is perpendicular to the second direction.

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