Manufacturing method for solid electrolytic capacitors

Abstract

A solid electrolytic capacitor according to the present invention is provided with: a sheet laminate formed by alternately laminating a plurality of flat cathode electrode foils and a plurality of flat capacitor elements, in which dielectric layers and solid electrolyte layers are sequentially formed on surfaces of flat anode electrode foils, with a conductive adhesion layer interposed therebetween; and an insulating resin which seals the sheet laminate. The distance between foils when the anode electrode foils and the cathode electrode foils are laminated is such that the interior of the region enclosed by edges of the sheet laminate is shorter than the edges, which are an outer peripheral section of the sheet laminate.

Description

[Technical Field]

[0001] The present invention relates to a solid electrolytic capacitor having a structure in which a laminate of a plurality of capacitor elements is molded with an insulating resin. [Background technology]

[0002] Patent Document 1 describes a method for manufacturing a solid electrolytic capacitor and a solid electrolytic capacitor. The solid electrolytic capacitor described in Patent Document 1 includes a plurality of flat-film capacitor elements and a plurality of metal foils (cathodes). The flat-film capacitor elements include a foil-like valve metal substrate, a porous portion of the valve metal substrate and a dielectric layer formed on the surface thereof, and a solid electrolyte layer formed on the surface of the dielectric layer.

[0003] The flat film capacitor elements and the metal foils are alternately stacked to form an element stack, which is then sealed with an insulating resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-79866 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the solid electrolytic capacitor shown in Patent Document 1, through-holes for cutting into individual pieces are formed in the metal foil. When forming such through-holes, burrs are generated at the edges of the metal foil (where the through-holes are formed). Furthermore, in the solid electrolytic capacitor shown in Patent Document 1, heat and pressure are applied in the process of forming the element stack. Furthermore, in order to improve the characteristics (low resistance and conductivity) of the solid electrolytic capacitor, it is necessary to shorten the distance between the flat film capacitor element and the metal foil.

[0006] When the above-mentioned heating and pressurizing is performed, the elements constituting the solid electrolytic capacitor undergo expansion and deformation, which may cause burrs on the edge of the metal foil (cathode) to short-circuit to the valve metal base (anode).

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a solid electrolytic capacitor that can suppress short circuits between the anode and cathode and achieve high reliability. [Means for solving the problem]

[0008] The solid electrolytic capacitor of the present invention comprises a plurality of flat-film capacitor elements each having a flat-film anode electrode foil on the surface of which a dielectric layer and a solid electrolyte layer are sequentially formed, a sheet laminate formed by alternately stacking a plurality of flat-film cathode electrode foils with a conductive adhesive layer interposed therebetween, and an insulating resin sealing the sheet laminate. When the anode electrode foil and the cathode electrode foil are stacked, the distance between the foils is shorter inside the area surrounded by the edges of the sheet laminate than at the edges, which are the outer periphery of the sheet laminate.

[0009] This configuration ensures that the anode foil and cathode foil are closer to each other at the inner portion than at the outer periphery. This ensures a sufficient distance between the anode foil and cathode foil at the outer periphery where burrs are likely to occur. This prevents contact between the anode and cathode, reducing defects due to short circuits.

[0010] The method for manufacturing a solid electrolytic capacitor of the present invention includes the steps of: forming a plurality of flat-film capacitor elements by sequentially forming a dielectric layer and a solid electrolyte layer on the surface of a flat-film anode electrode foil; forming a plurality of flat-film cathode electrode foils; alternately stacking the plurality of flat-film capacitor elements and the plurality of flat-film cathode electrode foils with a conductive adhesive layer interposed therebetween to form a sheet laminate; and sealing the sheet laminate with an insulating resin. The sheet laminate forming step involves sandwiching an elastic body between the sheet laminate and a press plate, and applying heat and pressure.

[0011] This method allows the manufacture of a solid electrolytic capacitor in which the anode electrode foil and the cathode electrode foil are spaced apart at the edges where burrs are likely to occur. This solid electrolytic capacitor can suppress contact between the anode and cathode, thereby reducing defects due to short circuits.

[0012] The method for manufacturing a solid electrolytic capacitor of the present invention includes the steps of forming a plurality of flat-film capacitor elements by sequentially forming a dielectric layer, an inner solid electrolyte layer, and an outer solid electrolyte layer on the surface of a flat-film anode electrode foil, forming a plurality of flat-film cathode electrode foils, alternately stacking the flat-film capacitor elements and the flat-film cathode electrode foils with the outer solid electrolyte layers interposed therebetween to form a sheet laminate, and sealing the sheet laminate with an insulating resin. In the sheet laminate forming step, an elastic body is sandwiched between the sheet laminate and a press plate, and heat and pressure are applied.

[0013] This method allows the manufacture of a solid electrolytic capacitor in which the anode electrode foil and the cathode electrode foil are spaced apart at the edges where burrs are likely to occur. This solid electrolytic capacitor can suppress contact between the anode and cathode, thereby reducing defects due to short circuits. [Effects of the Invention]

[0014] According to the present invention, a method for manufacturing a solid electrolytic capacitor that can suppress short circuits between the anode and the cathode and achieve high reliability can be provided. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a side cross-sectional view showing the configuration of the solid electrolytic capacitor according to the first embodiment. [Figure 2] Figure 2(A) is a side cross-sectional view showing the configuration of a set of a capacitor element and a cathode electrode before singulation, Figure 2(B) is a side cross-sectional view showing the configuration of a capacitor element before singulation, and Figure 2(C) is a side cross-sectional view showing the configuration of a set of a capacitor element and a cathode electrode after singulation. [Figure 3]FIG. 3(A) is a diagram schematically illustrating the structure of a capacitor element and a cathode electrode of the present invention, and FIG. 3(B) is a diagram schematically illustrating the structure of a capacitor element and a cathode electrode of a conventional configuration. [Figure 4] FIG. 4(A) is a diagram showing the height difference when a capacitor element of the present invention and a cathode electrode are heated and pressurized, and FIG. 4(B) is a diagram showing the height difference when a capacitor element of a conventional configuration and a cathode electrode are heated and pressurized. [Figure 5] FIG. 5 is a flowchart showing an example of a schematic flow of the method for manufacturing the solid electrolytic capacitor according to this embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of a process for forming a capacitor element sheet. [Figure 7] FIG. 7(A) is an external perspective view showing the shapes of the anode electrode and dielectric layer of the capacitor element before singulation, and FIG. 7(B) is an external perspective view showing the shape of the capacitor element before singulation. [Figure 8] FIG. 8 is an external view of the multi-state device. [Figure 9] FIG. 9 is an external perspective view showing the shape of the cathode electrode before being divided into individual pieces. [Figure 10] FIG. 10 is a flowchart showing an example of a process for forming a sheet stack. [Figure 11] 11(A) and 11(B) are external perspective views showing a state in which second dams are formed on the capacitor element sheet. [Figure 12] 12(A) and 12(B) are external perspective views showing a state in which a second dam and an adhesive are formed on the capacitor element sheet. [Figure 13] 13(A) and 13(B) are exploded perspective views showing the state in which the capacitor element sheet and the cathode electrode sheet are laminated together. [Figure 14] Figure 14(A) is an exploded perspective view showing the stacked state of capacitor element sheets and cathode electrode sheets in a multi-layered state, and Figure 14(B) is an external perspective view showing the stacked state of capacitor element sheets and cathode electrode sheets in a multi-layered state. [Figure 15]FIG. 15 is a diagram showing the configuration when the capacitor element sheet and the cathode electrode sheet are laminated together and heated and pressed. [Figure 16] 16(A) and 16(B) are side cross-sectional views showing the configuration of a set of a capacitor element and a cathode electrode before singulation according to the second embodiment. [Figure 17] 17(A) and 17(B) are external perspective views showing a capacitor element sheet according to the second embodiment. [Figure 18] FIG. 18 is a flowchart showing an example of a process for forming a sheet stack according to the second embodiment. [Figure 19] 19(A) and 19(B) are side cross-sectional views showing the configuration of a set of a capacitor element and a cathode electrode before singulation according to the third embodiment. [Figure 20] 20(A) and 20(B) are external perspective views showing a capacitor element sheet according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] [First embodiment] A solid electrolytic capacitor according to a first embodiment of the present invention and a method for manufacturing the solid electrolytic capacitor will be described with reference to the drawings.

[0017] (Explanation of the Schematic Configuration of Solid Electrolytic Capacitor 1) First, the structure of a solid electrolytic capacitor according to an embodiment of the present invention will be described. Fig. 1 is a side cross-sectional view showing the configuration of a solid electrolytic capacitor according to a first embodiment. In Fig. 1, only the insulating resin and external electrodes are hatched to make the drawing easier to see. Fig. 2(A) is a side cross-sectional view showing the configuration of a set of capacitor elements and cathode electrodes before singulation. Fig. 2(B) is a side cross-sectional view showing the configuration of a set of capacitor elements and cathode electrodes after singulation. Fig. 2(C) is a side cross-sectional view showing the configuration of a set of capacitor elements and cathode electrodes after singulation.

[0018] As shown in FIGS. 1, 2(A), 2(B), and 2(C), the solid electrolytic capacitor 1 includes a capacitor element laminate 100, an insulating resin 50, an external electrode 61, and an external electrode 62. The capacitor element laminate 100 includes a plurality of flat-film capacitor elements 10, a plurality of flat-film cathode electrodes 20, a second dam 30, and an adhesive 40. While FIG. 1 shows four flat-film capacitor elements 10 and four cathode electrodes, the number of such elements is not limited to four. The cathode electrode 20 corresponds to the "cathode electrode foil" of the present invention, and the adhesive 40 corresponds to the "conductive adhesive layer" of the present invention. The side cross-sectional views in FIGS. 1, 2(A), 2(B), and 2(C) are cross-sectional views taken along a plane perpendicular to the top surface 101 and bottom surface 102 of the capacitor element laminate 100 in FIG. 1.

[0019] As shown in FIG. 2(B), the capacitor element 10 includes a flat film-like anode electrode 11, a dielectric layer 12, and a CP layer (solid electrolyte layer) 13.

[0020] Although detailed structural illustrations are omitted in Figures 2(A), 2(B), and 2(C), the anode 11 has numerous pores. In other words, the anode 11 is porous (a porous body). The thickness ratio of the porous portion on one side of the anode 11 to the core metal portion and the porous portion on the other side is approximately 1:1:1. The dielectric layer 12 covers the outer surface of the anode 11. Because detailed structural illustrations of the anode 11 are omitted in Figures 2(A), 2(B), and 2(C), the dielectric layer 12 is illustrated as if it were covering the macroscopic surface of the anode 11. In reality, the dielectric layer 12 covers not only the macroscopic surface of the anode 11 but also the inner surfaces of the numerous pores in the anode 11. The anode 11 corresponds to the "anode electrode foil" in this invention.

[0021] The CP layer 13 covers the surface of the dielectric layer 12. A frame-shaped first dam 14 is formed on the outer periphery of the CP layer 13. The first dam 14 has insulating properties. The first dam 14 limits the area in which the CP layer 13 is formed.

[0022] The CP layer 13 has a laminated structure of an inner layer CP (inner layer solid electrolyte layer) 131 and an outer layer CP (outer layer solid electrolyte layer) 132. The inner layer CP131 is formed on the surface of the dielectric layer 12, and the outer layer CP132 is formed on the surface of the inner layer CP131.

[0023] The plurality of capacitor elements 10 and the plurality of cathode electrodes 20 are alternately stacked so that their flat film surfaces are parallel to each other and overlap each other in plan view.

[0024] A second dam 30 and an adhesive 40 are disposed between adjacent capacitor elements 10 and cathode electrodes 20. Second dam 30 is insulating, while adhesive 40 is conductive.

[0025] Second dam 30 is frame-shaped. Adhesive 40 is disposed inside the frame defined by second dam 30. Adjacent capacitor elements 10 and cathode electrodes 20 are adhered and electrically connected by adhesive 40.

[0026] In this stacked state, the first ends 10E1 (see FIG. 2(C)) of the plurality of capacitor elements 10 are located at approximately the same position in side view. Similarly, the second ends 10E2 (see FIG. 2(C)) of the plurality of capacitor elements 10 are located at approximately the same position in side view. Furthermore, the first ends 20E1 (see FIG. 2(C)) of the plurality of cathode electrodes 20 are located at approximately the same position in side view. Similarly, the second ends 20E2 (see FIG. 2(C)) of the plurality of cathode electrodes 20 are located at approximately the same position in side view.

[0027] The first ends 10E1 of the plurality of capacitor elements 10 and the second ends 20E2 of the plurality of cathode electrodes 20 are arranged on the first end side of the capacitor element stack 100. The first ends 10E1 of the plurality of capacitor elements 10 protrude outward beyond the second ends 20E2 of the plurality of cathode electrodes 20.

[0028] The second ends 10E2 of the plurality of capacitor elements 10 and the first ends 20E1 of the plurality of cathode electrodes 20 are arranged on the second end side of the capacitor element stack 100. The first ends 20E1 of the plurality of cathode electrodes 20 protrude outward beyond the second ends 10E2 of the plurality of capacitor elements 10.

[0029] With this structure, capacitor element stack 100 is realized, which has top surface 101 and bottom surface 102 at both ends in the stacking direction of multiple capacitor elements 10 and multiple cathode electrodes 20.

[0030] The capacitor element stack 100 is sealed with insulating resin 50. More specifically, the insulating resin 50 covers the capacitor element stack 100 except for first ends 10E1 of the plurality of capacitor elements 10 (first ends 10E1 of the anode electrodes 11) and first ends 20E1 of the plurality of cathode electrodes 20.

[0031] The external electrode 61 covers the first end (first end 10E1 of the anode electrode 11) of the insulating resin 50. The external electrode 61 is connected to the first ends 10E1 of the anode electrodes 11 of the plurality of capacitor elements .

[0032] The external electrode 62 covers the second end (the first end 20E1 of the cathode electrode 20) of the insulating resin 50. The external electrode 62 is connected to the first ends 20E1 of the plurality of cathode electrodes 20.

[0033] The solid electrolytic capacitor 1 is realized by the above configuration.

[0034] (Detailed structure of solid electrolytic capacitor 1) Next, the detailed structures of the capacitor element 10 and the cathode electrode 20 that constitute the solid electrolytic capacitor 1 will be described with reference to Figures 3(A) and 3(B). Figure 3(A) is a side cross-sectional view that schematically shows the structure of the capacitor element 10 and the cathode electrode 20, and is an enlarged view of the structure of Figure 2(A) described above. Figure 3(B) is a side cross-sectional view that schematically shows the structure of the capacitor element 10 and the cathode electrode 20 according to a conventional configuration. The side cross-sectional views in Figures 3(A) and 3(B) are cross-sectional views taken along a plane perpendicular to the top surface 101 and the bottom surface 102 of the capacitor element laminate 100 in Figure 1.

[0035] Note that the respective structures are enlarged and exaggerated for ease of understanding. Also, although only one set of capacitor element 10 and cathode electrode 20 is shown in Figures 3(A) and 3(B), solid electrolytic capacitor 1 is formed by stacking multiple such sets.

[0036] First, the configuration of the cathode electrode 20 and the second dam 30 will be defined. (Definition of the Second Dam 30) The second dam 30 will now be described. The second dam 30 is made of a resin with high rigidity. More specifically, the second dam 30 is preferably made of a resin containing silica filler.

[0037] (Definition of the cathode electrode 20) The cathode electrode 20 is made of, for example, aluminum, titanium, copper, silver, etc. It is preferable that the cathode electrode 20 can be brought close to the capacitor element 10. In other words, it is preferable that the cathode electrode 20 has a flexible configuration. This flexibility is defined as the ease of bending as follows.

[0038] Bending ease (kN x m 2 )=Young's modulus×(thickness of cathode electrode 20) 3 The smaller the value of this bendability, the easier it is to bend the cathode electrode 20. In particular, the bendability should be between 0.0085 and 16.25, and more preferably between 0.22 and 2.06.

[0039] Specific values ​​will be explained using aluminum, which has the smallest Young's modulus (the easiest to bend) among the materials for the cathode electrode 20 described above, as an example. The Young's modulus of aluminum is in the range of 68 to 76. For example, if the thickness of the cathode electrode 20 is 15 to 30 μm, the bendability of the cathode electrode 20 is 0.22 to 2.06 kN×m 2 This becomes:

[0040] Next, the configuration of the present invention shown in Fig. 3(A) will be compared with the conventional configuration shown in Fig. 3(B). The configuration of the present invention and the conventional configuration have the following in common.

[0041] (Configuration 1) A second dam 30 having a frame-shaped opening is formed on the first surface of capacitor element 10. (Configuration 2) An adhesive 40 is placed inside the opening of the second dam 30. (Configuration 3) Capacitor element 10 and cathode electrode 20 are bonded together via adhesive 40, and then heated and pressurized.

[0042] However, the configuration of the present invention and the conventional configuration differ in the method of heating and pressing in the above-described configuration 3. These will be described in detail below. Note that the heating and pressing process described below is explained using a configuration of capacitor element 10 and cathode electrode 20, but as described above, it is actually performed on a configuration in a multi-state (a state in which multiple solid electrolytic capacitors 1 are arranged) before the solid electrolytic capacitor 1 is divided into individual pieces.

[0043] (Configuration of the present invention shown in Figure 3(A)) 3(A), in the configuration of the present invention, capacitor element 10 and cathode electrode 20 are bonded together using press plate 310 and elastic body 300. Elastic body 300 may be made of any material that has resilience, such as silicone rubber, silicone sponge, or silicone rubber, and that is resistant to heat when heated and pressurized.

[0044] A cathode electrode 20 is placed on the capacitor element 10 via an adhesive 40. An elastic body 300 is placed on the cathode electrode 20, and heat and pressure are applied from above the elastic body 300 using a press plate 310. According to Pascal's principle, stress is applied to the elastic body 300 equally across the entire contact surface between the second dam 30 and the adhesive 40. Here, the elastic body 300 is easily deformed during heat and pressure application. On the other hand, the second dam 30 is less likely to deform than the adhesive 40 (the adhesive 40 is more easily deformed than the second dam 30). Therefore, by applying heat and pressure using the elastic body 300, the adhesive 40 is more likely to deform and become thinner than the second dam 30. As a result, the portion of the cathode electrode 20 not supported by the second dam 30 (the portion of the adhesive 40) bends toward the capacitor element 10, and the adhesive 40 is forced to spread over the entire surface of the capacitor element 10 within the area surrounded by the second dam 30. As a result, the cathode electrode 20 and the capacitor element 10 (CP layer 13 of the capacitor element 10) are closely bonded together over a wide area by the adhesive 40.

[0045] In this case, the portion overlapping with the second dam 30 and its vicinity, i.e., the portion corresponding to the outer periphery of the capacitor element 10 (sheet laminate), is defined as the end of the capacitor element 10, and the distance between these ends is defined as d1. Furthermore, the area surrounded by the outer periphery of the capacitor element 10 is defined as the interior, and the distance between this interior is defined as d2. Comparing the distance d1 and the distance d2, d1 > d2. In other words, by subjecting the capacitor element 10 and the cathode electrode 20 to a heat and pressure treatment using the elastic body 300, the distance between the capacitor element 10 and the cathode electrode 20 can be made closer inside than at the end of the capacitor element 10.

[0046] It is not necessary that the distance between the capacitor element 10 and the cathode electrode 20 be uniform (distance d2) throughout the entire interior of the capacitor element 10. It is sufficient that the distance d2 is at least partially within the capacitor element 10.

[0047] (Conventional configuration shown in Figure 3(B)) 3(B), in the conventional configuration, the distance between capacitor element 10 and cathode electrode 20 at the end and inside of capacitor element 10 is d3. In other words, when applying heat and pressure using a press plate, the bottom dead center is determined by second dam 30. Therefore, it is difficult to shorten the distance between capacitor element 10 and cathode electrode 20.

[0048] 4(A) and 4(B) are used to compare the height difference when the capacitor element 10 and the cathode electrode 20 are heated and pressurized by the above-mentioned method. Fig. 4(A) is a diagram showing the height difference when the capacitor element of the present invention and the cathode electrode are heated and pressurized, and Fig. 4(B) is a diagram showing the height difference when the capacitor element and the cathode electrode of a conventional configuration are heated and pressurized.

[0049] Compare Figure 4(A) with Figure 4(B). In each figure, except for the area where the through-hole is formed, darker areas indicate a higher elevation difference, and lighter areas indicate a lower elevation difference. Details of the through-hole will be described later.

[0050] 4(A) shows that the difference in height between the inside and the edge of capacitor element 10 is greater than that in FIG. 4(B). That is, by applying heat and pressure using elastic body 300, it is possible to shorten distance d2 between cathode electrode 20 and the inside of capacitor element 10, and to lengthen (increase) distance d1 between cathode electrode 20 and the outer periphery of capacitor element 10.

[0051] Here, the structure in FIG. 3(A) and the structure in FIG. 3(B) will be compared. (1) Contact area of ​​adhesive 40 In the configuration of the present invention, heating and pressure are applied using elastic body 300, so that cathode electrode 20 is bonded over a wider area to capacitor element 10 so as to conform to the movable region. That is, cathode electrode 20 and outer layer CP132 of capacitor element 10 are bonded over a wider area. This prevents peeling between outer layer CP132 of capacitor element 10 and cathode electrode 20.

[0052] On the other hand, a comparison is made with a conventional configuration in which heating and pressurizing treatment is performed without using elastic body 300. Because second dam 30 is made of a highly rigid resin, the bottom dead center is determined by the height of second dam 30. Therefore, the distance between cathode electrode 20 and capacitor element 10 is approximately the same as the height of second dam 30.

[0053] That is, when comparing the configuration of the present invention with the conventional configuration, the configuration of the present invention can reduce the distance between the cathode electrode 20 and the outer layer CP132 of the capacitor element, thereby increasing the contact area, thereby suppressing peeling between the capacitor element 10 and the cathode electrode 20.

[0054] Furthermore, at the end where the burrs are generated, the distance between the cathode electrode 20 and the anode electrode 11 of the capacitor element 10 is large. Therefore, the burrs of the cathode electrode 20 can be prevented from short-circuiting to the anode electrode 11.

[0055] (2) Thickness of adhesive 40 In the configuration of the present invention, heat and pressure are applied using elastic body 300, so adhesive 40 spreads over a wider area against capacitor element 10. This makes adhesive 40 thinner and wider, and shortens the distance between cathode electrode 20 and outer layer CP132 of capacitor element 10. In other words, equivalent series resistance ESR decreases, and conductivity increases.

[0056] On the other hand, in the conventional configuration, the bottom dead center of the cathode electrode 20 is determined by the second dam 30. That is, compared to the configuration of the present invention, the adhesive 40 is less likely to become thinner than the thickness of the second dam 30. Also, compared to the configuration of the present invention, the adhesive 40 is less likely to spread. Therefore, the equivalent series resistance ESR is less likely to decrease.

[0057] In other words, in the configuration of the present invention, the distance (d2) between the capacitor element 10 and the cathode electrode 20 at a position inside the capacitor element 10 is shorter than the distance (d1) at the end of the capacitor element 10. This reduces the equivalent series resistance ESR and increases the conductivity.

[0058] On the other hand, in the conventional configuration, the distance between capacitor element 10 and cathode electrode 20 is d3. That is, the distance between capacitor element 10 and cathode electrode 20 is longer than in the present invention. Therefore, the conventional configuration has a larger equivalent series resistance ESR than in the present invention.

[0059] That is, as in the configuration of the present invention, the second dam 30 is less likely to deform than the adhesive 40, and the capacitor element 10 and the cathode electrode 20 are heated and pressurized using the elastic body 300, thereby realizing a solid electrolytic capacitor 1 with better characteristics. Furthermore, short circuits due to burrs can be suppressed, and a decrease in the reliability of the solid electrolytic capacitor 1 and the occurrence of defective products can be suppressed.

[0060] (Method of manufacturing solid electrolytic capacitor 1) The solid electrolytic capacitor 1 having the above-described configuration is manufactured, for example, as follows: Fig. 5 is a flowchart showing an example of a schematic flow of the method for manufacturing the solid electrolytic capacitor according to this embodiment.

[0061] A capacitor element sheet is formed (FIG. 5: S11). A plurality of capacitor elements 10, each forming a different solid electrolytic capacitor 1, are formed in an array on the capacitor element sheet.

[0062] Next, the capacitor element sheet and the cathode electrode sheet are laminated to form a sheet laminate (FIG. 5: S12). The cathode electrode sheet has a plurality of cathode electrodes 20 formed in an array, each forming a different solid electrolytic capacitor 1. This forms a structure in which a plurality of capacitor element laminates 100 are arranged in a plane. In other words, the sheet laminate is a structure in which a plurality of capacitor element laminates 100 are arranged in a plane.

[0063] Next, the sheet stack is sealed with insulating resin 50 (FIG. 5: S13). As will be described in detail later, at this time, through holes that penetrate from the top surface to the bottom surface of the sheet stack are provided in the sheet stack, and resin sealing is performed by compression molding.

[0064] The process up to this sealing with insulating resin 50 is carried out in a multi-state (state in which a plurality of what will become solid electrolytic capacitors 1 are arranged) before the solid electrolytic capacitor 1 is divided into individual pieces.

[0065] Next, the sheet laminate sealed with insulating resin 50 is cut into individual pieces (FIG. 5: S14). Specifically, cutting is performed along cutting lines E11, E12, S11, and S12 shown in FIG. 13(B), which will be described later. This results in multiple solid electrolytic capacitors 1 (referred to as "solid electrolytic capacitor 1 bodies") without external electrodes formed thereon. Thereafter, the solid electrolytic capacitor 1 bodies are secondary sealed with insulating resin 50. More specifically, the side surfaces of the solid electrolytic capacitor 1 bodies (surfaces cut along cutting lines S11 and S12 (top surface, bottom surface, and side surfaces other than the end surfaces where the anode electrode 11 and cathode electrode 20 are exposed)) are covered with the secondary sealing of insulating resin 50. This allows the anode electrode 11 and cathode electrode 20, which would otherwise be unnecessarily exposed during singulation, to be covered with insulating resin 50.

[0066] Next, external electrodes 61 and 62 are formed on the end faces of the element body of solid electrolytic capacitor 1 (FIG. 5: S15).

[0067] Next, each step will be described in more detail.

[0068] (Capacitor element sheet forming process) Fig. 6 is a flowchart showing an example of a process for forming a capacitor element sheet. Fig. 7(A) is an external perspective view showing the shapes of the anode electrode and dielectric layer of the capacitor element before singulation, and Fig. 7(B) is an external perspective view showing the shape of the capacitor element before singulation. Fig. 8 is an external view in a multi-layer state.

[0069] Anode 11 is subjected to chemical conversion treatment to form dielectric layer 12 (FIG. 6: S111). At this time, a large number of holes are formed on the surface of anode 11 by etching, and the area near the surface of anode 11 is porous. Dielectric layer 12 covers the surface of anode 11, including the inner surfaces of the holes.

[0070] Next, anode through holes are formed in the anode electrode 11 (FIG. 6: S112). More specifically, as shown in FIG. 7(A), a plurality of cylindrical anode through holes 19C and groove-shaped anode through holes 19L are formed in the anode electrode 11. The cylindrical anode through holes 19C and the groove-shaped anode through holes 19L are alternately arranged along the direction in which the portions that will become the anode electrodes 11 are arranged. The cylindrical anode through holes 19C are formed at positions that will form first ends 10E1 of the anode electrodes 11, and the groove-shaped anode through holes 19L are formed at positions that straddle the portions that will become adjacent anode electrodes 11 and at positions that will form second ends 10E2 of the adjacent anode electrodes 11.

[0071] These anode through holes 19C and 19L are formed by punching, which results in the generation of a considerable amount of burrs. Note that anode through holes 19C and 19L can also be formed by laser processing, but in this case, dross may remain as with the burrs generated by punching.

[0072] Next, a CP layer (solid electrolyte layer) 13 is formed on the surface of the dielectric layer 12 (FIG. 6: S113). More specifically, as shown in FIG. 7(B), a first dam 14 having a frame-shaped opening is formed. Then, the CP layer 13 (a laminated structure of an inner layer CP131 and an outer layer CP132) is formed within the opening of the first dam 14.

[0073] As shown in FIG. 8, this structure is implemented in a multi-state in which a plurality of capacitor elements 10 (a structure consisting of an anode electrode 11, a dielectric layer 12, a CP layer 13, and a first dam 14) are arranged two-dimensionally.

[0074] (Cathode electrode sheet forming process) FIG. 9 is an external perspective view showing the shape of the cathode electrode before being divided into individual pieces.

[0075] 9 , a plurality of cylindrical cathode through holes 29C and groove-shaped cathode through holes 29L are formed in the cathode electrode 20. The cylindrical cathode through holes 29C and the groove-shaped cathode through holes 29L are alternately arranged along the direction in which the portions that will become the cathode electrodes 20 are arranged. The cylindrical cathode through holes 29C are formed at positions that will form first ends 20E1 of the cathode electrodes 20, and the groove-shaped cathode through holes 29L are formed at positions that straddle the portions that will become adjacent cathode electrodes 20 and at positions that will form second ends 20E2 of the adjacent cathode electrodes 20.

[0076] Cathode through hole 29C and cathode through hole 29L are also formed by punching. This results in the generation of a fair amount of burrs. Cathode through hole 29C and cathode through hole 29L can also be formed by laser processing, but in this case too, dross may remain, similar to the burrs caused by punching.

[0077] (Sheet stack formation process) Fig. 10 is a flowchart showing an example of a process for forming a sheet laminate. Figs. 11(A) and 11(B) are external perspective views showing a state in which second dams have been formed on capacitor element sheets. Fig. 11(A) shows the multi-layer structure, and Fig. 11(B) shows the portion of one capacitor element. Figs. 12(A) and 12(B) are external perspective views showing a state in which second dams and adhesive have been formed on capacitor element sheets. Fig. 12(A) shows the multi-layer structure, and Fig. 12(B) shows the portion of one capacitor element. Figs. 13(A) and 13(B) are exploded perspective views showing the state in which capacitor element sheets and cathode electrode sheets are laminated, showing the portion corresponding to one solid electrolytic capacitor. Fig. 14(A) is an exploded perspective view showing the laminated state of capacitor element sheets and cathode electrode sheets in the multi-layer structure, and Fig. 14(B) is an external perspective view showing the laminated state of capacitor element sheets and cathode electrode sheets in the multi-layer structure. FIG. 15 is a diagram showing the configuration when the capacitor element sheet and the cathode electrode sheet are laminated together and heated and pressed.

[0078] A second dam 30 is formed on the sheet laminate (FIG. 10: S121). More specifically, as shown in FIGS. 11(A) and 11(B), the second dam 30 has a frame-shaped opening. The second dam 30 is formed at a position overlapping the first dam 14.

[0079] Next, as shown in FIGS. 12(A) and 12(B), adhesive 40 is placed inside the opening of the second dam 30 (FIG. 10: S122).

[0080] Next, as shown in Figures 13(A), 13(B), 14(A), and 14(B), capacitor element sheets and cathode electrode sheets are alternately stacked (Figure 10: S123). More specifically, the capacitor element sheets and cathode electrode sheets are stacked so as to satisfy the following conditions:

[0081] When viewed in the stacking direction, the plurality of cylindrical anode through holes 19C in the capacitor element sheet and the groove-shaped cathode through holes 29L in the cathode electrode sheet overlap each other. When viewed in the stacking direction, the groove-shaped anode through-holes 19L in the capacitor element sheet and the plurality of cylindrical cathode through-holes 29C in the cathode electrode sheet overlap with each other. When viewed in the stacking direction, the groove-shaped anode through-hole 19L in the capacitor element sheet and the groove-shaped cathode through-hole 29L in the cathode electrode sheet overlap each other. The number of these through holes formed corresponds to the number of capacitor elements arranged in the sheet laminate, and therefore the sheet laminate is provided with a plurality of through holes that penetrate from the top surface to the bottom surface of the sheet laminate.

[0082] Next, the sheet laminate is heated and pressurized (FIG. 10: S124). As a result, the capacitor element sheets and the cathode electrode sheets are bonded together by the adhesive 40, forming a sheet laminate. During this heating and pressurizing, as shown in FIG. 15, an elastic body 300 is sandwiched between the sheet laminate and a press plate 310. The press plate 310 heats and presses the sheet laminate via this elastic body 300. As a result, as shown in FIG. 3(A), each capacitor element 10 and each cathode electrode 20 are bonded together. In this way, by using the elastic body 300, the outer periphery (mainly the area of ​​the second dam 30) can be made thicker than the inside (mainly the area of ​​the adhesive 40), which solves the problems of poor conductivity and burrs described above.

[0083] [Second embodiment] A solid electrolytic capacitor according to a second embodiment of the present invention and a method for manufacturing the solid electrolytic capacitor will be described with reference to the drawings. Figures 16(A) and 16(B) are side cross-sectional views showing the configuration of a set of capacitor elements and cathode electrodes before singulation according to the second embodiment. Figures 17(A) and 17(B) are external perspective views showing a capacitor element sheet according to the second embodiment.

[0084] The solid electrolytic capacitor 1A according to the second embodiment differs from the solid electrolytic capacitor 1 according to the first embodiment in that it does not include the adhesive 40. The other configuration of the solid electrolytic capacitor 1A is the same as that of the solid electrolytic capacitor 1, and a description of similar parts will be omitted.

[0085] As shown in Figures 16(A) and 17(B), the second dam 30 is frame-shaped. The outer layer CP (outer layer solid electrolyte layer) 132A is disposed inside the frame defined by the second dam 30. In other words, the inner layer CP131 is formed inside the frame defined by the first dam 14, and the outer layer CP132A is formed on the surface of the inner layer CP. Furthermore, the outer layer CP132A is also formed inside the frame defined by the second dam 30.

[0086] Even in this configuration, adjacent capacitor elements 10A and cathode electrodes 20 are bonded and electrically connected by outer layer CP (outer layer solid electrolyte layer) 132A formed inside second dam 30.

[0087] 16(B), an elastic body 300 is placed on the cathode electrode 20, and heat and pressure are applied from above the elastic body 300 using a press plate 310. The pressure from the press plate 310 is transmitted via the elastic body 300 and the cathode electrode 20 to the entire contact surface between the cathode electrode 20 and the second dam 30 and the outer layer CP132A.

[0088] During heating and pressurization, the outer layer CP132A is more easily deformed than the second dam 30. Furthermore, the elastic body 300 deforms in accordance with the deformation of the object to be pressurized, thereby continuously transmitting pressure to the easily deformed portion of the object to be pressurized. Therefore, by applying pressure and heat using the elastic body 300, the easily deformed outer layer CP132A is deformed more than the second dam 30, which is less likely to deform. As a result, the outer layer CP132A is more easily deformed and thinner than the second dam 30.

[0089] 16(A) and 16(B), the portion of the cathode electrode 20 not supported by the second dam 30 (the portion of the outer layer CP132A) bends toward the capacitor element 10A, and the outer layer CP132A spreads over the entire surface of the capacitor element 10A within the area surrounded by the second dam 30. As a result, the cathode electrode 20 and the capacitor element 10A are closely bonded over a wide area by the outer layer CP132A.

[0090] FIG. 18 is a flowchart showing an example of a process for forming a sheet stack.

[0091] A second dam 30 is formed on the sheet laminate (FIG. 18: S121). More specifically, as shown in FIG. 16(A), the second dam 30 having a frame-shaped opening is formed. The second dam 30 is formed at a position overlapping the first dam 14.

[0092] Next, as shown in FIGS. 17(A) and 17(B), the outer layer CP132A is disposed inside the opening of the second dam 30 (FIG. 10: S221).

[0093] Next, as shown in Figures 13(A), 13(B), 14(A), and 14(B) shown in the first embodiment, capacitor element sheets and cathode electrode sheets are alternately stacked (Figure 18: S123). More specifically, the capacitor element sheets and cathode electrode sheets are stacked so as to satisfy the same conditions as in the first embodiment.

[0094] Next, the sheet laminate is heated and pressurized (FIG. 18: S124). As a result, the capacitor element sheet (more specifically, the capacitor element sheet here corresponds to the sheet formed up to the inner layer CP131) and the cathode electrode sheet are bonded by the outer layer CP132A, forming a sheet laminate. During this heating and pressurizing, as shown in FIG. 16(B), an elastic body 300 is sandwiched between the sheet laminate and a press plate 310. The press plate 310 heats and presses the sheet laminate via this elastic body 300.

[0095] 16(B), each capacitor element 10A is bonded to each cathode electrode 20. In this way, by using the elastic body 300, the outer periphery (mainly the area of ​​the second dam 30) can be made thicker than the inside (mainly the area of ​​the outer layer CP132A), which solves the problems of conductive properties and burrs.

[0096] That is, even with this configuration, the second dam 30 is less likely to deform than the adhesive 40, and a solid electrolytic capacitor 1A with better characteristics can be realized by applying heat and pressure to the capacitor element 10A and the cathode electrode 20 using the elastic body 300. Furthermore, short circuits due to burrs can be suppressed, and a decrease in the reliability of the solid electrolytic capacitor 1A and the occurrence of defective products can be suppressed.

[0097] [Third embodiment] A solid electrolytic capacitor according to a third embodiment of the present invention will be described with reference to the drawings. Figures 19(A) and 19(B) are side cross-sectional views showing the configuration of a set of capacitor elements and cathode electrodes before singulation according to the third embodiment. Figures 20(A) and 20(B) are external perspective views showing a capacitor element sheet according to the third embodiment.

[0098] 19(A), 19(B), and 20(B), the solid electrolytic capacitor 1B according to the third embodiment differs from the solid electrolytic capacitor 1 according to the first embodiment in that it does not include the second dam 30 and the adhesive 40, and in the structure of the first dam 14B. The other configuration of the solid electrolytic capacitor 1B is the same as that of the solid electrolytic capacitor 1, and a description of similar parts will be omitted.

[0099] As shown in Figures 19(A), 19(B), 20(A), and 20(B), the first dam 14B is frame-shaped. The outer layer CP (outer layer solid electrolyte layer) 132B is disposed inside the frame defined by the first dam 14B. In other words, the inner layer CP131 and the outer layer CP132B are formed inside the frame defined by the first dam 14B. The outer layer CP132B is formed on the surface of the inner layer CP131.

[0100] Even with this configuration, adjacent capacitor elements 10B and cathode electrodes 20 are bonded and electrically connected by outer layer CP (outer solid electrolyte layer) 132B formed inside first dam 14B.

[0101] The first dam 14B has a predetermined rigidity on the surface that contacts the cathode electrode 20. More specifically, a portion of the first dam 14B is made of a resin with high rigidity, similar to the second dam 30 in the first embodiment. More specifically, the first dam 14B includes the surface that contacts the cathode electrode 20, and at least a portion of the first dam 14B in the thickness direction (hereinafter, the contact portion of the first dam 14B) is preferably made of a resin containing silica filler.

[0102] 19(B), the elastic body 300 is placed on the cathode electrode 20, and heat and pressure are applied from above the elastic body 300 using a press plate 310. Stress is applied to the elastic body 300 equally across the entire contact surface between the first dam 14B and the outer layer CP132B.

[0103] When heated and pressurized, the elastic body 300 is easily deformed. On the other hand, at the contact portion of the first dam 14B, the first dam 14B is less likely to deform than the outer layer CP132B (the outer layer CP132B is more easily deformed than the first dam 14B). Therefore, by heating and pressurizing using the elastic body 300, the outer layer CP132B is more likely to deform and become thinner than the first dam 14B.

[0104] As a result, the portion of the cathode electrode 20 not supported by the second dam 30 (the portion of the outer layer CP132B) bends toward the capacitor element 10, and the outer layer CP132B spreads over the entire surface of the capacitor element 10 within the area surrounded by the first dam 14B. As a result, the cathode electrode 20 and the capacitor element 10 are closely bonded over a wide area by the outer layer CP132B.

[0105] The contact portion of the first dam 14B preferably has a shape and thickness that is more rigid than the outer layer CP132B when heated and pressurized using the elastic body 300 in the thickness direction of the solid electrolytic capacitor 1B.

[0106] 19(B), each capacitor element 10B is bonded to each cathode electrode 20. In this way, by using the elastic body 300, the outer periphery (mainly the area of ​​the second dam 30) can be made thicker than the inside (mainly the area of ​​the outer layer CP132B), which solves the problems of conductive properties and burrs.

[0107] That is, even with this configuration, the first dam 14B is less likely to deform than the outer layer CP132B, and a solid electrolytic capacitor 1B with better characteristics can be realized by applying heat and pressure to the capacitor element 10B and the cathode electrode 20 using the elastic body 300. Furthermore, short circuits due to burrs can be suppressed, and a decrease in the reliability of the solid electrolytic capacitor 1B and the occurrence of defective products can be suppressed.

[0108] (Explanation of an example of specific materials of each component of the solid electrolytic capacitor 1) (Capacitor element 10) The capacitor element 10 is realized, for example, using the following materials and thicknesses.

[0109] The anode electrode 11 is made of, for example, a metal such as aluminum, tantalum, niobium, titanium, zirconium, or magnesium, or an alloy containing these metals. The anode electrode 11 is preferably made of aluminum or an aluminum alloy. The anode electrode 11 may be made of any valve metal that exhibits so-called valve action.

[0110] The anode electrode 11 is preferably flat, and the thickness of the core portion (the center portion not reached by the pores of the porous body) of the anode electrode 11 is preferably 5 μm or more and 100 μm or less. The thickness (thickness of one side) of the porous portion (the portion where the pores of the porous body are formed) is preferably 5 μm or more and 200 μm or less.

[0111] The dielectric layer 12 is preferably made of an oxide film of the anode electrode 11. For example, when an aluminum foil is used for the anode electrode 11, the dielectric layer 12 is formed by oxidizing the aluminum foil in an aqueous solution containing boric acid, phosphoric acid, adipic acid, or their sodium salts or ammonium salts. The thickness of the dielectric layer 12 is preferably 1 nm or more and 100 nm or less.

[0112] The inner layer CP131 may be a PEDOT:PSS layer realized by, for example, a conductive polymer having a skeleton of pyrroles, thiophenes, anilines, or the like, or a conductive polymer having a skeleton of thiophenes such as PEDOT [poly(3,4-ethylenedioxythiophene)], and composited with polystyrene sulfonate (PSS) as a dopant. The inner layer CP131 may be formed, for example, by a method of forming a polymer film of poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 12 using a treatment liquid containing a monomer such as 3,4-ethylenedioxythiophene, or by a method of applying a dispersion of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric portion and drying it.

[0113] The thickness of the outer layer CP132 is preferably 2 μm or more and 20 μm or less The material of the outer layer CP132 is the same as the material of the inner layer CP131.

[0114] The adhesive 40 may be a mixture of insulating resin such as epoxy resin or phenolic resin and conductive particles such as carbon or silver.

[0115] The cathode electrode 20 is made of, for example, aluminum, titanium, copper, silver, etc. In terms of ease of bending, the cathode electrode 20 is preferably made of aluminum or an aluminum alloy. The thickness of the cathode electrode 20 is, for example, approximately the same as the thickness of the anode electrode 11.

[0116] The insulating resin 50 may contain a filler. Examples of suitable resins include epoxy resin, phenol resin, polyimide resin, silicone resin, polyamide resin, and liquid crystal polymer. Examples of suitable fillers include insulating oxide particles such as silica particles, alumina particles, titania particles, and zirconia particles. The maximum diameter of the filler is preferably 30 μm or more and 40 μm or less. For example, a material containing silica particles in a solid epoxy resin is more preferable.

[0117] The correspondence between the configuration according to the present invention and the above-mentioned configuration will be described below. [Note] <1> a sheet laminate formed by alternately laminating a plurality of flat film capacitor elements, each having a dielectric layer and a solid electrolyte layer formed in that order on the surface of a flat film anode electrode foil, and a plurality of flat film cathode electrode foils via a conductive adhesive layer; an insulating resin that seals the sheet laminate; Equipped with a solid electrolytic capacitor, wherein when the anode electrode foil and the cathode electrode foil are laminated, the distance between the foils is shorter inside a region surrounded by the ends of the sheet laminate than at the ends, which are the outer periphery of the sheet laminate.

[0118] <2> The end portion is thicker than the interior portion. <1> The solid electrolytic capacitor according to claim 1.

[0119] <3> The bendability of the anode electrode foil and the cathode electrode foil is as follows: is calculated by multiplying the Young's modulus of the anode electrode foil and the cathode electrode foil by the cube of the thickness of the anode electrode foil and the cathode electrode foil, The bendability is 0.0085 to 16.25. <1> or <2> The solid electrolytic capacitor according to claim 1.

[0120] <4> The anode electrode foil and the cathode electrode foil are made of aluminum. <1> ~ <3> 10. The solid electrolytic capacitor according to claim 9, wherein

[0121] <5> a step of sequentially forming a dielectric layer and a solid electrolyte layer on the surface of a flat film-shaped anode electrode foil to form a plurality of flat film-shaped capacitor elements; forming a plurality of flat film-shaped cathode electrode foils; a step of alternately stacking the plurality of flat film capacitor elements and the plurality of flat film cathode electrode foils via a conductive adhesive layer to form a sheet laminate; a step of sealing the sheet laminate with an insulating resin; and The step of forming the sheet laminate includes: An elastic body is sandwiched between the sheet laminate and a press plate, and heated and pressurized. A method for manufacturing a solid electrolytic capacitor.

[0122] <6> In the step of forming the sheet laminate, a frame-shaped insulating second dam is formed between the capacitor element and the cathode electrode foil, and a conductive adhesive is disposed within the frame of the second dam; the second dam is less likely to deform than the adhesive during the heating and pressurizing process; <5> 10. A method for producing the solid electrolytic capacitor according to claim 9.

[0123] <7> forming a plurality of flat-film capacitor elements by sequentially forming a dielectric layer, an inner solid electrolyte layer, and an outer solid electrolyte layer on the surface of a flat-film anode electrode foil; forming a plurality of flat film-shaped cathode electrode foils; a step of alternately stacking the plurality of flat film capacitor elements and the plurality of flat film cathode electrode foils with the outer solid electrolyte layers interposed therebetween to form a sheet laminate; a step of sealing the sheet laminate with an insulating resin; and The step of forming the sheet laminate includes: An elastic body is sandwiched between the sheet laminate and a press plate, and heated and pressurized. A method for manufacturing a solid electrolytic capacitor.

[0124] <8> In the step of forming the sheet laminate, a frame-shaped insulating second dam is disposed between the capacitor element and the cathode electrode foil, and the outer solid electrolyte layer is disposed within the frame of the second dam; During the heating and pressurizing process, the second dam is less likely to deform than the outer solid electrolyte layer. <7> 10. A method for producing the solid electrolytic capacitor according to claim 9. [Explanation of symbols]

[0125] d1...distance d2…distance 1, 1A, 1B...Solid electrolytic capacitor 10...Capacitor element 10E1…1st end 10E2…2nd end 11...Anode electrode 12...Dielectric layer 13,13A,13B…CP layer 14,14B...First Dam 19C...Through hole for anode 19L...Through hole for anode 20...Cathode electrode 20E1…1st end 20E2…2nd end 29C…Cathode through hole 29L…Cathode through hole 30...Second Dam 40...Adhesive 50...Insulating resin 61...External electrode 62...External electrode 100... Capacitor element laminate 101...Top 102...Bottom 131...Inner CP 132,132A,132B…Outer layer CP 300...Elastic body 310...Press plate

Claims

1. forming a plurality of flat film capacitor elements by sequentially forming a dielectric layer and a solid electrolyte layer on the surface of a flat film anode electrode foil; forming a plurality of flat film-shaped cathode electrode foils; a step of alternately stacking the plurality of flat film capacitor elements and the plurality of flat film cathode electrode foils via a conductive adhesive layer to form a sheet laminate; a step of sealing the sheet laminate with an insulating resin; and The step of forming the sheet laminate includes: An elastic body is sandwiched between the sheet laminate and a press plate, and heated and pressurized. a frame-shaped insulating second dam is formed between the capacitor element and the cathode electrode foil, and a conductive adhesive is disposed within the frame of the second dam; the second dam is less likely to deform than the adhesive when heated and pressurized; A method for manufacturing a solid electrolytic capacitor.

2. forming a plurality of flat-film capacitor elements by sequentially forming a dielectric layer, an inner solid electrolyte layer, and an outer solid electrolyte layer on the surface of a flat-film anode electrode foil; forming a plurality of flat film-shaped cathode electrode foils; a step of alternately stacking the plurality of flat membrane capacitor elements and the plurality of flat membrane cathode electrode foils with the outer solid electrolyte layers interposed therebetween to form a sheet laminate; a step of sealing the sheet laminate with an insulating resin; and The step of forming the sheet laminate includes: An elastic body is sandwiched between the sheet laminate and a press plate, and heated and pressurized. a frame-shaped insulating second dam is disposed between the capacitor element and the cathode electrode foil, and the outer solid electrolyte layer is disposed within the frame of the second dam; the second dam is less likely to deform than the outer solid electrolyte layer during the heating and pressurizing process; A method for manufacturing a solid electrolytic capacitor.

3. When the anode electrode foil and the cathode electrode foil are laminated, the foil-to-foil distance is: the inside of the region surrounded by the end of the sheet stack is shorter than the end, which is the outer periphery of the sheet stack; The method for manufacturing the solid electrolytic capacitor according to claim 1 or 2.

4. A method for manufacturing a solid electrolytic capacitor as described in claim 3, wherein the thickness of the end is greater than the thickness of the interior.

5. The bendability of the anode electrode foil and the cathode electrode foil is is calculated by multiplying the Young's modulus of the anode electrode foil and the cathode electrode foil by the cube of the thickness of the anode electrode foil and the cathode electrode foil, The bendability is 0.0085 to 16.

25. The method for manufacturing the solid electrolytic capacitor according to claim 1 or 2.

6. The anode electrode foil and the cathode electrode foil are made of aluminum. The method for manufacturing the solid electrolytic capacitor according to claim 1 or 2.

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