Solid electrolytic capacitor manufacturing method and solid electrolytic capacitor

Abstract

This solid electrolytic capacitor manufacturing method includes a capacitor element forming step, an anode through-hole forming step, a cathode through-hole forming step, a first sheet laminate forming step, a second sheet laminate forming step, a disposing step, an encapsulating step, and a dicing step. The capacitor element forming step involves forming a dielectric layer and a solid electrolyte layer in succession on the surface of a flat anode electrode foil to form a plurality of flat capacitor elements. The anode through-hole forming step involves forming anode through-holes penetrating through the plurality of flat capacitor elements in the thickness direction. The cathode through-hole forming step involves forming cathode through-holes penetrating through a flat cathode electrode foil in the thickness direction. The first sheet laminate forming step involves forming a first sheet laminate by alternately laminating the plurality of flat capacitor elements and the flat cathode electrode foil with the solid electrolyte layer interposed. The second sheet laminate forming step involves cutting the first sheet laminate along a first cutting line to form a plurality of second sheet laminates. The disposing step involves disposing the plurality of second sheet laminates in a resin substrate formed from a first resin having insulating properties. The encapsulating step involves covering the sides of the second sheet laminates along the first cutting line with a second resin having insulating properties. The encapsulating step further involves encapsulating the second sheet laminates by filling the anode through-holes and the cathode through-holes with the second resin. The dicing step involves cutting the second sheet laminates encapsulated by the first and second resins along a second cutting line and a third cutting line orthogonal to the second cutting line. The resin substrate has a plurality of spaces formed by a bottom section, a first wall section, a second wall section, and two side sections. In the disposing step, the plurality of second sheet laminates are respectively disposed in the plurality of spaces.

Description

Method for manufacturing a solid electrolytic capacitor, and a solid electrolytic capacitor

[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.

[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-shaped 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.

[0004] Patent Document 2 describes a method for manufacturing a solid electrolytic capacitor. The method for manufacturing a solid electrolytic capacitor described in Patent Document 2 includes a step of forming an element assembly, a step of forming a laminate, and a step of singulating the laminate. In the step of forming the element assembly, capacitor elements having a dielectric layer are arranged in a planar manner. In the step of forming the laminate, multiple element assemblies are stacked. In the singulation step, the multiple laminates are singulated into individual laminates.

[0005] JP 2019-79866 A JP 2020-194825 A

[0006] However, the manufacturing methods of solid electrolytic capacitors as exemplified in Patent Documents 1 and 2 include the following multiple steps: (Step 1) forming an element stack; (Step 2) sealing the element stack with an insulating material such as insulating resin; (Step 3) cutting the sealed element stack (primary dicing step); (Step 4) sealing the element stack cut in step 3 with an insulating material such as insulating resin; and (Step 5) singulating the element stack formed in step 4 (secondary dicing step).

[0007] That is, the manufacturing process of the solid electrolytic capacitor in Patent Documents 1 and 2 includes two sealing steps and two dicing steps, which means that the dicing is inefficient and takes a long processing time.

[0008] Therefore, when a solid electrolytic capacitor is formed using the manufacturing methods of Patent Documents 1 and 2, there is a risk that the manufacturing efficiency will decrease and productivity will also decrease in terms of cost.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for efficiently manufacturing a solid electrolytic capacitor, and the solid electrolytic capacitor.

[0010] The method for manufacturing a solid electrolytic capacitor of the present invention includes a capacitor element forming step, an anode through-hole forming step, a cathode through-hole forming step, a first sheet laminate forming step, a second sheet laminate forming step, an arrangement step, a sealing step, and a singulation step. In the capacitor element forming step, a dielectric layer and a solid electrolyte layer are sequentially formed on the surface of a flat-film anode electrode foil to form multiple flat-film capacitor elements. In the anode through-hole forming step, anode through-holes are formed that penetrate the multiple flat-film capacitor elements in the thickness direction. In the cathode through-hole forming step, cathode through-holes are formed that penetrate the flat-film cathode electrode foil in the thickness direction. In the first sheet laminate forming step, multiple flat-film capacitor elements and flat-film cathode electrode foils are alternately stacked with solid electrolyte layers interposed therebetween to form a first sheet laminate. In the second sheet laminate forming step, the first sheet laminate is cut along first cutting lines to form multiple second sheet laminates. In the arrangement process, multiple second sheet laminates are arranged on a resin base made of an insulating first resin. In the sealing process, the side surfaces of the second sheet laminates along the first cutting lines are covered with an insulating second resin. Furthermore, in the sealing process, the second sheet laminates are sealed by filling the anode through holes and the cathode through holes with the second resin. In the singulation process, the second sheet laminate sealed with the first resin and the second resin is singulated along the second cutting lines and third cutting lines perpendicular to the second cutting lines.

[0011] The resin base has a plurality of spaces each consisting of a bottom portion, a first wall portion, a second wall portion, and two side portions. In the arranging step, the plurality of second sheet laminates are arranged in the plurality of spaces, respectively.

[0012] In this manufacturing method, a second sheet laminate obtained by dividing a first sheet laminate is placed on a resin base, thereby filling the side surfaces and the anode and cathode through holes with insulating resin. This sheet laminate is then diced to form individualized sheet laminates. That is, the steps of forming the second sheet laminate, filling the insulating resin, and forming the solid electrolytic capacitor element bodies by dividing each sheet laminate can be performed once each to form the desired individualized sheet laminates. This eliminates the need to perform the step of cutting the insulating resin, which is more difficult to cut than the capacitor laminate, multiple times between other steps, thereby enabling efficient formation of solid electrolytic capacitors.

[0013] The solid electrolytic capacitor of the present invention includes a plurality of flat-film capacitor elements, an anode through-hole, a flat-film cathode electrode foil, a cathode through-hole, a sheet laminate, a first resin layer, and a second resin layer. The flat-film capacitor elements each include a flat-film anode electrode foil with a dielectric layer and a solid electrolyte layer sequentially formed on the surface thereof. The anode through-hole penetrates the plurality of flat-film capacitor elements in the thickness direction. The cathode through-hole penetrates the flat-film cathode electrode foil in the thickness direction. The sheet laminate is formed by alternately stacking the plurality of flat-film capacitor elements and the flat-film cathode electrode foil with the solid electrolyte layer interposed therebetween, and has a top surface, a bottom surface opposite the top surface, and side surfaces connected to the top surface and bottom surface. The first resin layer has a space for accommodating the sheet laminate. The second resin layer, together with the first resin layer, seals the sheet laminate.

[0014] This solid electrolytic capacitor has anode through-holes and cathode through-holes in the sheet laminate, which are filled with insulating resin. The side surfaces of the sheet laminate are covered with a first resin layer and a second resin layer, each of which is made of insulating resin. This sheet laminate can be diced to form individualized sheet laminates. That is, the desired individualized sheet laminates can be formed by performing the steps of forming the second sheet laminate, filling the insulating resin, and forming the solid electrolytic capacitor element by singulating each sheet laminate once. This eliminates the need to perform the step of cutting the insulating resin, which is more difficult to cut than the capacitor laminate, multiple times between other steps, thereby achieving an efficiently formed solid electrolytic capacitor.

[0015] According to the present invention, it is possible to provide a method for efficiently manufacturing a solid electrolytic capacitor, and a solid electrolytic capacitor manufactured by this manufacturing method.

[0016] FIG. 1 is a side cross-sectional view showing the configuration of a solid electrolytic capacitor according to the first embodiment. FIGS. 2A and 2B are side cross-sectional views showing the configuration of a set of capacitor elements and cathode electrodes before singulation. FIG. 3 is a flowchart showing an example of a general flow of a method for manufacturing a solid electrolytic capacitor according to the present embodiment. FIG. 4 is an external perspective view showing a state in which capacitor element sheets and cathode electrode sheets are laminated. FIG. 5 is a flowchart showing an example of a capacitor element sheet forming process. FIGS. 6A, 6B, 6C, and 6D are schematic views showing a process for forming capacitor elements of the solid electrolytic capacitor according to the first embodiment. FIG. 7 is an external view of a multi-layered capacitor element. FIG. 8 is an external perspective view showing the shape of a cathode electrode before singulation. FIG. 9 is an external perspective view of a multi-layered capacitor element showing the shape of a cathode electrode before singulation. FIG. 10 is a flowchart showing an example of a process for forming a first sheet laminate. FIG. 11 is an exploded perspective view showing a state in which capacitor element sheets and cathode electrode sheets are laminated. FIG. 12 is a flowchart showing an example of a process for forming a second sheet laminate. FIG. 13 is a schematic diagram showing the structure of a second sheet laminate. FIG. 14 is a schematic diagram showing the structure of a resin base. FIG. 15(A) is a schematic diagram showing a structure in which a second sheet laminate is disposed on a resin base, and FIG. 15(B) is a cross-sectional view taken along line A-A in FIG. 15(A). FIG. 16 is a cross-sectional view showing a state in which the second sheet laminate is sealed. FIG. 17(A) is a schematic diagram showing a state in which the second sheet laminate is sealed with insulating resin, and FIG. 17(B) is a schematic diagram showing a state in which the second sheet laminate is separated into individual pieces. FIG. 18 is a schematic diagram of a resin base according to a second embodiment. FIG. 19 is a schematic diagram of a resin base according to a third embodiment. FIG. 20 is a schematic diagram of a resin base according to a fourth embodiment. FIGS. 21(A) and 21(B) are schematic diagrams of a resin base according to a fourth embodiment. FIG. 22 is a schematic diagram of a resin base according to a fifth embodiment. FIGS. 23(A) and 23(B) are schematic diagrams of a resin base according to a fifth embodiment. Fig. 24 is a schematic diagram of a resin base according to a sixth embodiment, Fig. 25 is a schematic diagram of a resin base according to a seventh embodiment, and Fig. 26 is a schematic diagram of a resin base according to the seventh embodiment.27(A) and 27(B) are schematic diagrams of a resin base according to a seventh embodiment. Fig. 28 is a schematic diagram of a resin base according to a first modified example. Fig. 29 is a schematic diagram of a resin base according to a second modified example.

[0017] First Embodiment A method for manufacturing a solid electrolytic capacitor according to a first embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0018] (Explanation of Schematic Configuration of Solid Electrolytic Capacitor 1) First, the structure of a solid electrolytic capacitor manufactured by a method for manufacturing 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. Note that in FIG. 1, only the insulating resin and external electrodes are hatched to make the drawing easier to see. FIGS. 2(A) and 2(B) are side cross-sectional views showing the configuration of a set of capacitor elements and cathode electrodes before singulation.

[0019] As shown in FIGS. 1, 2(A), and 2(B), 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 and a plurality of flat-film cathode electrodes 20. Note that the number (number) of flat-film capacitor elements 10 and cathode electrodes 20 in the configuration shown in FIG. 1 is not limited thereto. The side cross-sectional views in FIGS. 1, 2(A), and 2(B) 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. This flat-film cathode electrode 20 corresponds to the "cathode electrode foil" of the present invention. Note that a more detailed structure of the insulating resin 50 will be described later.

[0020] 2(B), capacitor element 10 includes flat film anode electrode 11, dielectric layer 12, and CP layer (solid electrolyte layer) 13. Flat film anode electrode 11 corresponds to the "anode electrode foil" of the present invention.

[0021] Although detailed structural illustrations are omitted in Figures 2(A) and 2(B), the anode electrode 11 has numerous pores. In other words, the anode electrode 11 is porous (a porous body). The thickness ratio of the porous portion on one side of the anode electrode 11 to the core metal portion and the porous portion on the other side is approximately 1:1:1. A dielectric layer 12 covers the outer surface of the anode electrode 11. Because detailed structural illustrations of the anode electrode 11 are omitted in Figures 2(A) and 2(B), the dielectric layer 12 is schematically illustrated as covering the macroscopic surface of the anode electrode 11. In reality, the dielectric layer 12 covers not only the macroscopic surface of the anode electrode 11 but also the inner surfaces of the numerous pores in the anode electrode 11.

[0022] The CP layer 13 covers the surface of the dielectric layer 12. A frame-shaped CP dam 14 is formed on the outer periphery of the CP layer 13. The CP dam 14 has insulating properties. The CP dam 14 limits the area in which the CP layer 13 is formed.

[0023] 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 CP 131 is formed on the surface of the dielectric layer 12, and the outer layer CP 132 is formed on the surface of the inner layer CP 131.

[0024] Multiple capacitor elements 10 and multiple cathode electrodes 20 are alternately stacked so that their flat film surfaces are parallel and overlap in a planar view. In this case, the outer layer CP132 of each capacitor element is directly connected to the cathode electrode 20. In the structure shown in FIG. 2A , the outer layer CP132 of each capacitor element 10 is bonded to the cathode electrode 20 so that it abuts against the cathode electrode 20. This allows adjacent capacitor elements 10 and cathode electrodes 20 to be bonded and electrically connected. By stacking the capacitor elements 10 and cathode electrodes 20 in this manner without using an adhesive, the thickness of the solid electrolytic capacitor 1 can be reduced. Note that, if the adhesive does not affect the thickness of the solid electrolytic capacitor 1, the capacitor elements 10 and cathode electrodes 20 may be bonded using an adhesive. In this case, the adhesive preferably contains carbon.

[0025] In this stacked state, the first ends 10E1 (see FIG. 1) of the plurality of capacitor elements 10 are located at approximately the same position in side view. Similarly, the second ends 10E2 (see FIG. 1) of the plurality of capacitor elements 10 are located at approximately the same position in side view. Furthermore, the first ends 20E1 (see FIG. 1) of the plurality of cathode electrodes 20 are located at approximately the same position in side view. Similarly, the second ends 20E2 (see FIG. 1) of the plurality of cathode electrodes 20 are located at approximately the same position in side view.

[0026] 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 10E1 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.

[0027] 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 10E2 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.

[0028] With this structure, a capacitor element stack 100 having a top surface 101 and a bottom surface 102 at both ends in the stacking direction of the plurality of capacitor elements 10 and the plurality of cathode electrodes 20 is realized.

[0029] The capacitor element laminate 100 is sealed with insulating resin 50. The sealing step will be described in more detail later.

[0030] The external electrode 61 covers a first end of the insulating resin 50 (first ends 10E1 of the anode electrodes 11). The external electrode 61 is connected to the first ends 10E1 of the anode electrodes 11 of the plurality of capacitor elements 10. The external electrode 62 covers a second end of the insulating resin 50 (first ends 20E1 of the cathode electrodes 20). The external electrode 62 is connected to the first ends 20E1 of the plurality of cathode electrodes 20.

[0031] The solid electrolytic capacitor 1 is realized by the above configuration.

[0032] (Method for Manufacturing Solid Electrolytic Capacitor 1) The solid electrolytic capacitor 1 having the above-described configuration is manufactured, for example, as follows. Fig. 3 is a flowchart showing an example of a schematic flow of a method for manufacturing the solid electrolytic capacitor according to this embodiment. Fig. 4 is an external perspective view showing a state in which the capacitor element sheet and the cathode electrode sheet are laminated.

[0033] A capacitor element sheet is formed (FIG. 3: 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 (see FIG. 7 described later).

[0034] Next, as shown in Fig. 4, the capacitor element sheet and the cathode electrode sheet are laminated to form a first sheet laminate 110 (Fig. 3: S12). Note that the cathode electrode sheet has a plurality of cathode electrodes 20 formed thereon, each of which forms a different solid electrolytic capacitor 1. This forms a structure in which a plurality of capacitor element laminates 100 are two-dimensionally arranged in a plane. In other words, the first sheet laminate 110 is a structure in which a plurality of capacitor element laminates 100 are two-dimensionally arranged in a plane.

[0035] Next, as shown in Fig. 4, the first sheet laminate 110 is cut (divided) into strips along cutting lines S11 (Fig. 3: S13). These strip-shaped first sheet laminates 110 become a plurality of second sheet laminates 120 (see Fig. 13 described later). A more specific structure of the second sheet laminate 120 will be described later. These cutting lines S11 correspond to the "first cutting lines" of the present invention. Note that the strip shape refers to a rectangular parallelepiped shape that is rectangular in plan view (in this case, viewed in the direction in which the capacitor elements 10 and the cathode electrodes 20 are stacked), with laminates that will later become individual solid electrolytic capacitors lined up in the longitudinal direction and having a predetermined thickness (length in the stacking direction).

[0036] Next, as shown in Figures 15(A) and 15(B) described later, a plurality of second laminated sheets 120 are arranged on the resin substrate 510 (Figure 3: S14). A more specific structure will be described later.

[0037] Next, the second sheet laminate 120 is sealed with insulating resin 50 ( FIG. 3 : S15). At this time, as shown in FIG. 17(A) described later, through holes that penetrate from the top surface to the bottom surface of the second sheet laminate 120 are provided in the sheet laminate, and resin sealing is performed by compression molding. As a result, the through holes are filled with insulating resin 50. Furthermore, the insulating resin 50 covers each side surface of the plurality of second sheet laminates 120 along the cutting line S11, as well as the top and bottom surfaces of the plurality of second sheet laminates 120.

[0038] 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.

[0039] Next, the sheet laminate sealed with insulating resin 50 is cut into individual pieces ( FIG. 3 : S16). Specifically, cutting is performed along cutting lines S21 and E21 shown in FIG. 17(B) described below. This results in the formation of multiple solid electrolytic capacitors 1 (referred to as "solid electrolytic capacitor 1 element bodies") without external electrodes. In other words, the anode electrodes 11 and cathode electrodes 20 are covered with insulating resin 50, and individual pieces are formed in which the anode electrodes 11 and cathode electrodes 20 are not undesirably exposed to the outside. Cutting line S21 corresponds to the "second cutting line" of the present invention, and cutting line E21 corresponds to the "third cutting line" of the present invention.

[0040] Next, external electrodes 61 and 62 are formed on the end surfaces of the element body of solid electrolytic capacitor 1 (FIG. 3: S17).

[0041] Next, each step will be described in more detail. (Capacitor Element Sheet Forming Step) Fig. 5 is a flowchart showing an example of a capacitor element sheet forming step. Figs. 6(A), 6(B), 6(C), and 6(D) are schematic diagrams showing steps for forming capacitor elements of the solid electrolytic capacitor according to the first embodiment. Fig. 7 is an external view of the capacitor element in a multi-layered state. Note that Figs. 6(A), 6(B), 6(C), and 6(D) show portions of the capacitor element in a multi-layered state.

[0042] As shown in Fig. 6(A), anode 11 is subjected to chemical conversion treatment to form dielectric layer 12 (Fig. 5: S111). At this time, numerous holes are formed in the surface of anode 11 by etching, making the surface of anode 11 porous. Dielectric layer 12 covers the surface of anode 11, including the inner surfaces of the holes.

[0043] Next, a CP layer (solid electrolyte layer) 13 is formed on the surface of the dielectric layer 12 (FIG. 5: S112). More specifically, as shown in FIG. 6B, a CP dam 14 having a frame-shaped opening is formed. Then, as shown in FIG. 6C, a CP layer 13 (a laminated structure of an inner layer CP 131 and an outer layer CP 132) is formed within the opening of the CP dam 14.

[0044] Next, as shown in FIG. 6(D), anode through holes are formed in the anode electrode 11 (FIG. 5: S113). More specifically, as shown in FIG. 6(D), a plurality of cylindrical anode through holes 19C and groove-shaped anode through holes 19L are formed in the anode electrode 11. At this time, the plurality of cylindrical anode through holes 19C and groove-shaped anode through holes 19L penetrate not only the anode electrode 11 but also the CP dam 14. The plurality of cylindrical anode through holes 19C and groove-shaped anode through holes 19L are alternately arranged along the direction of the cutting line along which the portions that will become the plurality of anode electrodes 11 are aligned. The plurality of cylindrical anode through holes 19C are formed at positions that will realize the first ends 10E1 of the anode electrodes 11. 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 realize the second ends 10E2 of the adjacent anode electrodes 11.

[0045] As shown in FIG. 7, 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 CP dam 14) are arranged two-dimensionally.

[0046] In the above configuration, the CP dam 14 is formed in step S112, and then the anode through-hole is formed in the anode electrode 11 in step S113. However, the CP dam 14 may be formed after the anode through-hole is formed in the anode electrode 11 so as not to block the anode through-hole.

[0047] (Cathode Electrode Sheet Forming Process) Fig. 8 is a perspective view showing the shape of the cathode electrode before being divided into individual pieces, and Fig. 9 is a perspective view showing the shape of the cathode electrode in a multi-piece state before being divided into individual pieces.

[0048] 8 and 9 , a plurality of cylindrical cathode through holes 29C and groove-shaped cathode through holes 29L are formed in cathode electrode 20. The plurality of cylindrical cathode through holes 29C and groove-shaped cathode through holes 29L are alternately arranged along the direction of the cutting line along which the portions that will become the plurality of cathode electrodes 20 are aligned.

[0049] The plurality of cylindrical cathode through-holes 29C are formed at positions that will realize first ends 20E1 of the cathode electrodes 20. The groove-shaped cathode through-holes 29L are formed at positions that straddle portions that will become adjacent cathode electrodes 20 and at positions that will realize second ends 20E2 of adjacent cathode electrodes 20.

[0050] (Step of Forming First Sheet Laminate) Fig. 10 is a flowchart showing an example of the step of forming the first sheet laminate, and Fig. 11 is an exploded perspective view showing a structure in which capacitor element sheets and cathode electrodes are laminated.

[0051] As shown in Fig. 11 , capacitor element sheets and cathode electrode sheets are alternately stacked (Fig. 10: S121). More specifically, the capacitor element sheets and cathode electrode sheets are stacked so as to satisfy the following conditions: By stacking the capacitor element sheets and cathode electrode sheets in this manner, a first sheet laminate 110 is formed.

[0052] When viewed in the stacking direction (thickness direction), the plurality of cylindrical anode through holes 19C in the capacitor element sheet overlap with the groove-shaped cathode through holes 29L in the cathode electrode sheet (see FIG. 11 ). When viewed in the stacking direction (thickness direction), the groove-shaped anode through holes 19L in the capacitor element sheet overlap with the plurality of cylindrical cathode through holes 29C in the cathode electrode sheet (see FIG. 11 ). When viewed in the stacking direction (thickness direction), the groove-shaped anode through holes 19L in the capacitor element sheet overlap with the groove-shaped cathode through holes 29C in the cathode electrode sheet (see FIG. 11 ). Therefore, the first sheet laminate 110 is formed with a plurality of through holes that penetrate from the top surface to the bottom surface of the first sheet laminate 110.

[0053] Next, the first sheet laminate 110 is heated and pressed (FIG. 10: S122).

[0054] (Steps of forming and arranging second sheet laminate) Fig. 12 is a flowchart showing an example of a step of forming a second sheet laminate. Fig. 13 is a schematic diagram showing the structure of a second sheet laminate. Fig. 14 is a schematic diagram showing the structure of a resin base. Fig. 15(A) is a schematic diagram showing the structure in which the second sheet laminate is arranged on the resin base, and Fig. 15(B) is a cross-sectional view taken along line A-A in Fig. 15(A).

[0055] First, as shown in Fig. 13, the first sheet stack 110 is cut along cutting lines S11, thereby dividing the first sheet stack 110 into a plurality of rectangular second sheet stacks 120 (Fig. 12: S131).

[0056] The first sheet laminate 110 is cut using, for example, a guillotine blade. By using a guillotine blade, the second sheet laminate 120 can be cut accurately and efficiently. Furthermore, by using this cutting method, undesired dragging of the electrodes on the cut surface can be suppressed, and short-circuiting between the anode electrode 11 and the cathode electrode 20 can be suppressed. The first sheet laminate 110 may also be cut using an ultrasonic cutter.

[0057] Next, as shown in Figures 14, 15(A), and 15(B), the second sheet laminate 120 cut into strips is placed on the resin base 510 (Figure 12: S132). More specifically, the multiple second sheet laminates 120 are placed in multiple spaces 516 formed in the resin base 510, for example, by pick-and-place. At this time, the second sheet laminates 120 are placed in a state in which they can stand upright in the spaces 516. That is, the spaces 516 have a shape similar to that of the second sheet laminate 120. The state in which the second sheet laminate 120 can stand upright means that the stacking direction of the capacitor elements 10 and the cathode electrodes 20 of the second sheet laminate 120 is approximately parallel to the depth direction of the spaces 516.

[0058] The arrangement method is not limited to pick-and-place. For example, the following method can also be used. A plurality of second sheet laminates 120 are arranged on a stretchable sheet, and stretched to fit the shapes of the plurality of spaces 516 in the resin base 510. In this way, the plurality of second sheet laminates 120 are arranged at predetermined intervals. While maintaining this state, the plurality of second sheet laminates 120 are stacked one on top of the other so as to be accommodated in the plurality of spaces 516. Therefore, the plurality of second sheet laminates 120 can be easily arranged in the spaces 516.

[0059] (Structure of Resin Base) The structure of the resin base 510 described above will be described in more detail. The resin base 510 is made of insulating resin. This resin base 510 corresponds to the "first resin layer" and "first resin" in the present invention. As shown in FIG. 14 , the resin base 510 includes a bottom surface 511, wall portions 512, 514, 517, side surface portions 513, 515, and a plurality of spaces 516. The wall portions 512, 514, and 517 are parallel to each other. The side surface portion 513 and 515 are parallel to each other. The wall portions 512, 514, and 517 are perpendicular to the side surface portions 513, 515. The plurality of spaces 516 are formed by the bottom surface 511, the wall portions 512, 514, 517, and the side surface portions 513, 515. The walls 512, 514, and 517 correspond to the "first wall" and "second wall" of the present invention.

[0060] 14 , the multiple spaces 516 are formed parallel to the wall portions 512, 514, and 517 at predetermined intervals. In other words, the multiple spaces 516 are formed at predetermined intervals by the wall portions 512, 514, and 517 and the side portions 513 and 515, each of which has a predetermined thickness. This predetermined interval corresponds to the width of the wall portion 517. In this case, it is preferable that the multiple spaces 516 are formed at approximately equal intervals. This approximately equal arrangement includes a configuration in which the spaces are not intentionally equal due to manufacturing errors, and does not necessarily mean that the spaces are arranged perfectly evenly.

[0061] The plurality of second sheet stacks 120 are respectively disposed in the plurality of spaces 516 formed in this manner. At this time, the bottom surfaces of the plurality of second sheet stacks 120 are disposed so as to abut against the bottom surfaces of the plurality of spaces 516.

[0062] (Specific Arrangement Structure of Second Sheet Laminate) A more specific structure in which the second sheet laminate 120 is arranged on the resin base 510 will be described using Figures 15(A) and 15(B). Figure 15(A) is a schematic diagram showing a structure in which the second sheet laminate is arranged on the resin base 510, and Figure 15(B) is a cross-sectional view taken along line A-A in Figure 15(A). Note that in Figure 15(A), the side surface portions 513 and 515 in Figure 14 are omitted for clarity. Note that line A-A in Figure 15(A) is a direction perpendicular to the long side direction of the space 516 formed in the resin base 510.

[0063] 15(A) and 15(B), the plurality of second sheet laminates 120 are respectively arranged in the plurality of spaces 516. As shown in Fig. 15(B), the second sheet laminate 120 is preferably arranged at approximately the center of the space 516 along a direction perpendicular to the line A-A in Fig. 15(A).

[0064] Next, a more preferable structure of the resin base 510 will be described based on the structure in which the second sheet laminate 120 is arranged in FIGS. 15(A) and 15(B).

[0065] 15(B), the width D1 of the plurality of spaces 516 parallel to line A-A of the resin base 510 is greater than the width 120D of the second sheet laminate 120. In other words, it is preferable to provide some play so that the width D1 of the spaces 516 is greater than the width 120D of the second sheet laminate 120. This configuration allows the second sheet laminate 120 to be positioned in the spaces 516 more efficiently than if the width D1 of the spaces 516 and the width 120D of the second sheet laminate 120 were approximately the same. In this case, by bringing the width D1 of the spaces 516 closer to the width 120D of the second sheet laminate 120, the second sheet laminate 120 can be positioned in the spaces 516 with greater precision.

[0066] The height (depth) H1 of the space 516 in the resin base 510 can be determined arbitrarily. In this case, the height H1 of the space 516 is preferably a height that can prevent the second sheet laminate 120 from tipping over when the second sheet laminate 120 is placed in the space 516. The height H1 may be the same as the heights of the wall portions 512, 514, 517 and the side portions 513, 515, or may be smaller than the heights of the wall portions 512, 514, 517 and the side portions 513, 515.

[0067] Adjacent spaces 516 are formed with a distance D2 between them by wall portions 517. The width of the wall portions 517 (distance D2) may be determined depending on the size of the solid electrolytic capacitor 1 in step S16 of FIG.

[0068] (Sealing step of second sheet laminate) Next, the step of sealing the second sheet laminate 120 will be described with reference to Fig. 16. Fig. 16 is a cross-sectional view showing the state in which the second sheet laminate is sealed. Note that Fig. 16 is a cross-sectional view taken along line A-A in Fig. 15(A) similar to Fig. 15(B).

[0069] 16 , the second sheet laminate 120 disposed on the resin base 510 is sealed with insulating resin 520 so as to cover it. As a result, the top surface and side surfaces of the second sheet laminate 120 are sealed with insulating resin 520. The side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with insulating resin 520. This insulating resin 520 corresponds to the "second resin layer" and "second resin" in the present invention. The resin base 510 and insulating resin 520 correspond to the insulating resin 50 in the solid electrolytic capacitor 1 (see FIG. 1 ).

[0070] 17(A) and 17(B), a description will be given of the process of singulating the second sheet laminate 120. Fig. 17(A) is a schematic diagram showing the second sheet laminate 120 sealed with insulating resin, and Fig. 17(B) is a schematic diagram showing the second sheet laminate 120 singulated.

[0071] As shown in FIG. 17A, the second sheet laminate 120 is sealed with an insulating resin 50 (a resin base 510 and an insulating resin 520).

[0072] 3, the second sheet laminate 120 sealed with the insulating resin is diced along cutting lines S21 and E21 using a dicing blade (see FIG. 17B). At this time, if the cutting line E21 is parallel to line A-A in FIG. 15A, the cutting line S21 is defined between adjacent spaces 516 of the resin base 510, in other words, on the wall portion 517. More specifically, the cutting line S21 is preferably defined at approximately the center of the wall portion 517.

[0073] The sheet stack thus filled with insulating resin is divided into individual pieces in a single process in step S16 in FIG.

[0074] That is, a solid electrolytic capacitor can be formed by performing the sealing process with insulating resin (step S15 in FIG. 3 ) and the process of forming the solid electrolytic capacitor element by singulating it (step S16 in FIG. 3 ) once each. This allows for efficient formation of solid electrolytic capacitors. Furthermore, the process of cutting the insulating resin, which is more difficult to cut than the capacitor laminate, does not need to be performed multiple times between other processes, allowing for efficient formation of solid electrolytic capacitors. Furthermore, the number of times the dicing blade needs to be replaced due to singulation can be reduced, thereby reducing the cost of replacing the dicing blade. This improves the productivity of solid electrolytic capacitors.

[0075] Furthermore, the shapes of the plurality of cylindrical anode through holes 19C, the groove-shaped anode through holes 19L, the plurality of cylindrical cathode through holes 29C, and the groove-shaped cathode through holes 29L are very simple, that is, these through holes can be easily formed.

[0076] Furthermore, since a sufficient flow path for the insulating resin can be ensured, the insulating resin can be easily filled into the through holes.

[0077] The width of the groove-shaped anode through hole 19L and the groove-shaped cathode through hole 29L can be set to any size. More specifically, the width can be determined arbitrarily within a range that can prevent short circuits between adjacent capacitor elements before singulation.

[0078] As shown in the above process, the side surfaces of multiple rectangular second sheet laminates 120 are placed on the resin base 510 and then sealed with insulating resin. Therefore, the spacing between adjacent second sheet laminates 120 can be appropriately adjusted by adjusting the width (spacing D2) of the wall portions 517 that form the spaces 516 in the resin base 510. This ensures that the insulating resin flows around the side surfaces of the second sheet laminates 120. This allows the second sheet laminates 120 to be more reliably sealed with insulating resin. Furthermore, the cutting margins in the singulation process can be appropriately adjusted, preventing undesired exposure of the anode electrodes 11 and cathode electrodes 20 in the lateral direction during singulation.

[0079] It is preferable that the resin base 510 (first resin) and the insulating resin 520 (second resin) are made of the same component. This prevents breakage of the interface between the resin base 510 (first resin) and the insulating resin 520 (second resin) due to external stress or the like, thereby improving the strength of the solid electrolytic capacitor 1. It is also possible for the resin base 510 (first resin) and the insulating resin 520 (second resin) to be made of different components, provided that the strength of the solid electrolytic capacitor 1 is not impaired.

[0080] Second Embodiment A method for manufacturing a solid electrolytic capacitor according to a first modified example of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0081] 18 is a schematic diagram of a resin base 510A according to the second embodiment. As shown in FIG. 18, the solid electrolytic capacitor 1A according to the second embodiment differs from the solid electrolytic capacitor 1 according to the first embodiment in the shape of the space 516A in the resin base 510A. The other configuration of the solid electrolytic capacitor according to the second embodiment is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0082] 18 , the space 516A has a tapered shape. This tapered shape widens from the bottom surface portion 511 toward the direction in which the second sheet laminate 120 is disposed (toward the top surface portion of the resin base 510A). By having the space 516A have such a tapered shape, the second sheet laminate 120 can be easily disposed in the space 516A.

[0083] By using the configuration of the second embodiment, the side surface of the second sheet laminate 120 along the cutting line S11 is covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 of the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 of the first embodiment) can be performed once each. Therefore, the solid electrolytic capacitor can be formed efficiently. Furthermore, the tapered shape of the space 516A allows the solid electrolytic capacitor to be formed even more efficiently.

[0084] Third Embodiment A method for manufacturing a solid electrolytic capacitor according to a third embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0085] 19 is a schematic diagram of a resin base according to the third embodiment. As shown in FIG. 19, solid electrolytic capacitor 1B according to the third embodiment differs from solid electrolytic capacitor 1 according to the first embodiment in that protrusions 516P are provided in spaces 516B of resin base 510B. The other configuration of the solid electrolytic capacitor according to the third embodiment is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0086] As shown in FIG. 19 , the space 516B is provided with a protrusion 516P. The protrusion 516P is formed of an insulating resin. This protrusion 516P serves as an alignment mark and a spacer that allows easy determination of the placement position of the second sheet laminate 120. In other words, the second sheet laminate 120 is positioned approximately in the center of the space 516B by the protrusion 516P. The protrusion 516P may be formed anywhere on the bottom surface portion 511 as long as it is in a position and size that does not interfere with placement of the second sheet laminate 120 in the space 516B.

[0087] By using the configuration of the third embodiment, the side surface of the second sheet laminate 120 along the cutting line S11 is also covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 of the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 of the first embodiment) can be performed only once. Therefore, the solid electrolytic capacitor can be formed efficiently. Furthermore, since the space 516B has the protrusion 516P, the second sheet laminate 120 can be positioned in the space 516B with precision. Therefore, the solid electrolytic capacitor can be formed even more efficiently.

[0088] Fourth Embodiment A method for manufacturing a solid electrolytic capacitor according to a fourth embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0089] Fig. 20 is a schematic diagram of a resin base according to the fourth embodiment, and Fig. 21(A) and Fig. 21(B) are schematic diagrams of a resin base according to the fourth embodiment.

[0090] 20 , the solid electrolytic capacitor 1C according to the fourth embodiment differs from the solid electrolytic capacitor 1 according to the first embodiment in the structures of the walls 512C, 514C, and 517C and in the presence of a gap 518. The other configuration of the solid electrolytic capacitor according to the fourth embodiment is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0091] 20, the side surfaces 513 and 515 are omitted to make the structure of the resin base 510C easier to understand. Similarly, some reference numerals are omitted to make the structure of the resin base 510C clearer.

[0092] As shown in Figure 20, the wall portions 512, 514, and 517 in the first embodiment have a plurality of gaps 518 formed therein. This results in a plurality of wall portions 512C, 514C, and 517C. In other words, the wall portions 512C, 514C, and 517C are arranged at predetermined intervals in the long side direction. These predetermined intervals correspond to the gaps 518. The gaps 518 are preferably formed to have the same length as the height (depth) H1 of the space 516. The formation of these gaps 518 results in the wall portions 512C, 514C, and 517C having a height difference relative to the bottom surface portion 511.

[0093] The second sheet laminate 120 is disposed in the space 516 of the resin base 510C. The second sheet laminate 120 is sealed with insulating resin 520. As a result, the top surface and side surfaces of the second sheet laminate 120 are sealed with the insulating resin 520. That is, the side surfaces of the second sheet laminate 120 along the cutting line S11 (see FIG. 13 ) are covered with the insulating resin 520. Furthermore, as shown in FIGS. 21(A) and 21(B), the insulating resin 520 fills the gaps 518 between the wall portions 512C, 514C, and 517C. Therefore, the side surfaces of the gaps 518 also become contact surfaces between the resin base 510C and the insulating resin 520, increasing the contact area between the resin base 510C and the insulating resin 520.

[0094] By using the configuration of the fourth embodiment, the side surfaces of the second sheet laminate 120 along the cutting line S11 (see FIG. 13) are also covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 in the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 in the first embodiment) can be performed only once. Therefore, the solid electrolytic capacitor can be formed efficiently.

[0095] Furthermore, the multiple wall portions 512C, 514C, and 517C are arranged at predetermined intervals. As a result, the contact area between the insulating resin 520 and the wall portions 512C, 514C, and 517C is larger than that of the wall portions 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interface between the insulating resin 520 and the wall portions 512C, 514C, and 517C. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0096] Note that a plurality of gaps 518 may also be formed in the side surface portions 513 and 515 (not shown). With such a structure, the adhesive strength at the interfaces between the insulating resin 520 and the side surface portions 513 and 515 is further improved.

[0097] In the above-described configuration, a structure in which a plurality of gaps 518 are formed has been shown. However, it is preferable to form at least one gap 518. Furthermore, the plurality of gaps 518 may be formed at equal intervals along the cutting line S11 (see FIG. 13 ) in the second sheet laminate 120, or the plurality of gaps 518 may be formed unevenly.

[0098] Fifth Embodiment A method for manufacturing a solid electrolytic capacitor according to a fifth embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings. Fig. 22 is a schematic diagram of a resin base according to the fifth embodiment. Figs. 23(A) and 23(B) are schematic diagrams of a resin base according to the fifth embodiment. Note that the configurations shown in Fig. 22, 23(A), and 23(B) differ in the number of steps formed.

[0099] The solid electrolytic capacitor 1D according to the fifth embodiment differs from the solid electrolytic capacitor 1C according to the fourth embodiment in that a step portion 518D is provided in the gap 518. The other configuration of the solid electrolytic capacitor according to the fifth embodiment is the same as that of the solid electrolytic capacitor according to the fourth embodiment, and a description of the same parts will be omitted.

[0100] 22, the side surfaces 513 and 515 are omitted to make the structure of the resin base 510D easier to understand. Similarly, some reference numerals are omitted to make the structure of the resin base 510D clearer.

[0101] 22, 23A, and 23B, similar to the structure of the fourth embodiment, multiple gaps 518 are formed in the wall portions 512, 514, and 517. This results in multiple wall portions 512D, 514D, and 517D. More specifically, the multiple wall portions 512D, 514D, and 517D are arranged at equal intervals in the long side direction. Furthermore, at the positions where the gaps 518 are formed, step portions 518D are formed so as to have a difference in height with respect to the bottom surface portion 511.

[0102] The second sheet laminate 120 is placed in the space 516 of the resin base 510D. This second sheet laminate 120 is sealed with insulating resin 520. As a result, the top surface and side surfaces of the second sheet laminate 120 are sealed with the insulating resin 520. The side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with the insulating resin 520. Furthermore, the insulating resin 520 fills the gap 518 formed by the wall portions 512D, 514D, 517D and the step portion 518D. This increases the contact area between the resin base 510D and the insulating resin 520.

[0103] By using the configuration of the fifth embodiment, the side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 of the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 of the first embodiment) can be performed only once. Therefore, the solid electrolytic capacitor can be formed efficiently.

[0104] Furthermore, gaps 518 and step portions 518D are formed in the wall portions 512D, 514D, and 517D. As a result, the contact areas between the insulating resin 520 and the wall portions 512D, 514D, and 517D, the gaps 518, and the step portions 518D are larger than those of the wall portions 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interfaces between the insulating resin 520 and the wall portions 512D, 514D, and 517D, the gaps 518, and the step portions 518D. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0105] 23A and 23B, the step portion 518D may be formed in multiple steps spaced apart at predetermined intervals. By providing multiple step portions 518D in this manner, the adhesive strength at the interfaces between the insulating resin 520 and the walls 512D, 514D, and 517D, the gap 518, and the step portion 518D is further improved.

[0106] Although not shown, a plurality of gaps 518 and step portions 518D may also be formed in the side surface portions 513 and 515. With such a structure, the adhesive strength at the interfaces between the insulating resin 520 and the side surface portions 513 and 515 is further improved.

[0107] Sixth Embodiment A method for manufacturing a solid electrolytic capacitor according to a sixth embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0108] Fig. 24 is a schematic diagram of a resin base according to the sixth embodiment. As shown in Fig. 24, the solid electrolytic capacitor 1E according to the sixth embodiment differs from the solid electrolytic capacitor 1 according to the first embodiment in the structure of wall portions 512E, 514E, and 517E. The other configuration of the solid electrolytic capacitor according to the sixth embodiment is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0109] In FIG. 24, the side surfaces 513 and 515 are omitted to make the structure of the resin base 510E easier to understand.

[0110] 24, the wall portions 512E, 514E, and 517E have a shape with a gentle recess at the height (depth) H1 of the space 516. The shape of this recess may be uniform or non-uniform along the cutting line S11 (see FIG. 13) of the second sheet laminate 120. Note that the recess here refers to a region where the height of the wall portions 512E, 514E, and 517E decreases from the maximum height.

[0111] The second sheet laminate 120 is placed in the space 516 of the resin base 510E. This second sheet laminate 120 is sealed with insulating resin 520. As a result, the top surface and side surfaces of the second sheet laminate 120 are sealed with the insulating resin 520. The side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with the insulating resin 520. Furthermore, the insulating resin 520 fills the recesses of the wall portions 512E, 514E, and 517E. This increases the contact area between the resin base 510E and the insulating resin 520.

[0112] By using the configuration of the sixth embodiment, the side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 in the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 in the first embodiment) can be performed only once. Therefore, the solid electrolytic capacitor can be formed efficiently.

[0113] Furthermore, recesses are formed in the walls 512E, 514E, and 517E. As a result, the contact area between the insulating resin 520 and the walls 512E, 514E, and 517E is larger than that of the walls 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interfaces between the insulating resin 520 and the walls 512E, 514E, and 517E. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0114] Note that a plurality of recesses may also be formed in the side surface portions 513 and 515 (not shown). With such a structure, the adhesive strength at the interfaces between the insulating resin 520 and the side surface portions 513 and 515 is further improved.

[0115] Seventh Embodiment A method for manufacturing a solid electrolytic capacitor according to a seventh embodiment of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0116] Fig. 25 is a schematic diagram of a resin base according to the seventh embodiment. Fig. 26 is a schematic diagram of a resin base according to the seventh embodiment. Figs. 27(A) and 27(B) are schematic diagrams of a resin base according to the seventh embodiment. As shown in Figs. 25, 26, 27(A), and 27(B), the solid electrolytic capacitor 1F according to the seventh embodiment differs from the solid electrolytic capacitor 1C according to the fourth embodiment in the shapes of the wall portions 512F, 514F, and 517F. The other configuration of the solid electrolytic capacitor according to the seventh embodiment is the same as that of the solid electrolytic capacitor according to the fourth embodiment, and a description of similar parts will be omitted.

[0117] 25 and 26, side surface portions 513 and 515 are omitted to make the structure of resin base 510F easier to understand. Similarly, some reference numerals are omitted to make the structure of resin base 510F clearer.

[0118] 25, the plurality of wall portions 512F, 514F, 517F are cylindrical. The plurality of cylindrical wall portions 512F, 514F, 517F are formed at equal intervals along the cutting line S11 (see FIG. 13) of the second sheet laminate 120. In other words, this forms gaps 518. The formation of these gaps 518 results in the plurality of wall portions 512F, 514F, 517F having a height difference with respect to the bottom surface portion 511.

[0119] Similarly, as shown in Fig. 26, the plurality of wall portions 512F, 514F, and 517F are conical in shape. Alternatively, as shown in Fig. 27(A), the plurality of wall portions 512F, 514F, and 517F may be quadrangular pyramid-shaped. Alternatively, as shown in Fig. 27(B), the plurality of wall portions 512F, 514F, and 517F may be truncated conical in shape.

[0120] The second sheet laminate 120 is placed in the space 516 of the resin base 510F. This second sheet laminate 120 is sealed with insulating resin 520. As a result, the top surface and side surfaces of the second sheet laminate 120 are sealed with the insulating resin 520. The side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with the insulating resin 520. Furthermore, the insulating resin 520 fills the gap 518 formed between the wall portions 512F, 514F, 517F and the bottom surface portion 511. This increases the contact area between the resin base 510F and the insulating resin 520.

[0121] By using the configuration of the seventh embodiment, the side surfaces of the second sheet laminate 120 along the cutting line S11 are covered with insulating resin. Furthermore, the sealing process with insulating resin (step S15 in FIG. 3 in the first embodiment) and the process of forming the solid electrolytic capacitor element by dividing it into individual pieces (step S16 in FIG. 3 in the first embodiment) can be performed only once. Therefore, the solid electrolytic capacitor can be formed efficiently.

[0122] With this configuration, the contact area between the insulating resin 520 and the walls 512F, 514F, and 517F is larger than that of the walls 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interfaces between the insulating resin 520 and the walls 512F, 514F, and 517F. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0123] The side surface portions 513 and 515, not shown, may have the same shape as the wall portions 512F, 514F, and 517F. With such a structure, the adhesive strength at the interfaces between the insulating resin 520 and the side surface portions 513 and 515 is further improved.

[0124] [First Modification] A method for manufacturing a solid electrolytic capacitor according to a first modification of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0125] Fig. 28 is a schematic diagram of a resin base according to a first modification. As shown in Fig. 28, solid electrolytic capacitor 1G according to the first modification differs from solid electrolytic capacitor 1 according to the first embodiment in the structure of walls 512G, 514G, and 517G. The other configuration of the solid electrolytic capacitor according to the first modification is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0126] 28, side portions 513 and 515 are omitted to make the structure of resin base 510G easier to understand. Similarly, some reference numerals are omitted to make the structure of resin base 510G clearer.

[0127] As shown in FIG. 28, a resin base 510G according to the modified example has a structure that combines the wall structures of the fourth, fifth, sixth, and seventh embodiments.

[0128] With this configuration, the area of ​​contact between the insulating resin 520 and the wall and side surfaces is larger than that of the wall surfaces 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interface between the insulating resin 520 and the resin base 510G. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0129] The side surface portions 513 and 515, not shown, may have the same shape as the wall portions 512G, 514G, and 517G. With such a structure, the adhesive strength at the interfaces between the insulating resin 520 and the side surface portions 513 and 515 is further improved.

[0130] [Second Modification] A method for manufacturing a solid electrolytic capacitor according to a second modification of the present invention and a solid electrolytic capacitor manufactured by this manufacturing method will be described with reference to the drawings.

[0131] Fig. 29 is a schematic diagram of a resin base according to the second modification. As shown in Fig. 29, solid electrolytic capacitor 1H according to the second modification differs from solid electrolytic capacitor 1 according to the first embodiment in that gap 518H is formed. The other configuration of the solid electrolytic capacitor according to the second modification is the same as that of the solid electrolytic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0132] 29, the side surfaces 513 and 515 are omitted to make the structure of the resin base 510H easier to understand. Similarly, some reference numerals are omitted to make the structure of the resin base 510H clearer.

[0133] As shown in FIG. 29 , a gap 518H is formed in the wall portion 517H. The gap 518H has, for example, a cylindrical or rectangular parallelepiped shape and is formed at any position on the wall portion 517H. The gap 518H is formed at a position facing the side surface along the cutting line S11 when the second sheet laminate 120 is placed in the space 516. The gap 518H has a shape that penetrates the wall portion 517H. In other words, it is preferable that the gap 518H has a shape that communicates with the space 516. Note that the position and number of the gaps 518H are not limited to the structure shown in FIG. 29 . The gap 518H may also be formed in the wall portions 512 and 514.

[0134] With this configuration, the insulating resin 520 fills the gap 518H. As a result, the area of ​​contact between the insulating resin 520 and the wall and side surfaces is larger than that of the wall portions 512, 514, and 517 in the first embodiment. This improves the adhesive strength at the interface between the insulating resin 520 and the resin base 510H. In other words, a highly reliable solid electrolytic capacitor can be realized.

[0135] In each embodiment and each modified example, the surface roughness of the resin base is not specified. However, the resin base may have an uneven shape similar to the surface roughness. In this case, it is more preferable that the unevenness has a structure corresponding to the particle size of the resin and a structure that allows the insulating resin 520 to easily penetrate.

[0136] (Explanation of an example of specific materials, etc., 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 with the following thicknesses.

[0137] The anode 11 is made of a metal such as aluminum, tantalum, niobium, titanium, zirconium, or magnesium, or an alloy containing any of these metals. The anode 11 is preferably made of aluminum or an aluminum alloy. The anode 11 may be made of any valve metal that exhibits a so-called valve action.

[0138] The anode 11 is preferably flat, and the thickness of the core (the center portion not reached by the pores of the porous body) of the anode 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.

[0139] 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.

[0140] 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 sulfonic acid (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.

[0141] The thickness of the outer layer CP 132 is preferably 2 μm or more and 20 μm or less. The material of the outer layer CP 132 is the same as the material of the inner layer CP 131.

[0142] 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.

[0143] The insulating resin 50 (first resin and second resin) may contain a filler. Examples of suitable resins include epoxy resin, phenolic 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.

[0144] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H...Solid electrolytic capacitor 10...Capacitor element 10E1...First end 10E2...Second end 11...Anode electrode 12...Dielectric layer 13...CP layer 14...CP dam 19C, 19L...Anode through hole 20...Cathode electrode 20E1...First end 20E2...Second end 29C, 29L...Cathode through hole 50...Insulating resin 61, 62...External electrode 100...Capacitor element laminate 101...Top surface 102...Bottom surface 110...First sheet laminate 120...Second sheet laminate 510, 510A, 510B, 510C, 510D, 510E, 510F, 510G, 510H...Resin base 511... bottom surface portion 512, 512C, 512D, 512E, 512F, 512G, 514, 514C, 514D, 514E, 514F, 514G, 517, 517C, 517D, 517E, 517F, 517G, 517H... wall portion 513, 515... side portion 516, 516A, 516B... space 516P... protrusion portion 518, 518H... gap 518D... step portion 520... insulating resin 131... inner layer CP 132... outer layer CP E21, S11, S21... cutting line H1... height

Claims

1. A capacitor element forming 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; an anode through-hole forming step of forming an anode through-hole that penetrates the plurality of flat film-shaped capacitor elements in the thickness direction; a cathode through-hole forming step of forming a cathode through-hole that penetrates a flat film-shaped cathode electrode foil in the thickness direction; a first sheet laminate forming step of forming a first sheet laminate by alternately laminating the plurality of flat film-shaped capacitor elements and the flat film-shaped cathode electrode foil via the solid electrolyte layer; a second sheet laminate forming step of cutting the first sheet laminate along a first cutting line to form a plurality of second sheet laminate; an arranging step of arranging the plurality of second sheet laminates in a resin substrate made of a first resin having insulating properties; a sealing step of covering a side surface of the second sheet laminate along the first cutting line with a second resin having insulating properties and filling the anode through-hole and the cathode through-hole with the second resin to seal the second sheet laminate; a singulating step of singulating the second sheet laminate sealed with the first resin and the second resin by a second cutting line and a third cutting line orthogonal to the second cutting line, the resin substrate includes a bottom surface portion, a first wall portion, a second wall portion, and two side surface portions, and has a plurality of spaces, and in the arranging step, the plurality of second sheet laminates are respectively arranged in the plurality of spaces, a method for manufacturing a solid electrolytic capacitor.

2. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the second sheet laminate is formed by cutting the first sheet laminate into strips along the first cutting line.

3. The method for manufacturing a solid electrolytic capacitor according to claim 1 or claim 2, wherein the plurality of spaces are formed at a predetermined interval.

4. The method for manufacturing a solid electrolytic capacitor according to claim 3, wherein the plurality of spaces are arranged at a uniform interval.

5. The method for manufacturing a solid electrolytic capacitor according to claim 3 or claim 4, wherein protrusions are formed in the plurality of spaces.

6. The method for manufacturing a solid electrolytic capacitor according to any one of claims 1 to 5, wherein the first resin and the second resin are made of the same component.

7. The manufacturing method of the solid electrolytic capacitor according to any one of claims 1 to 6, wherein a part of the first wall portion and a part of the second wall portion have a height difference with respect to the bottom surface portion.

8. The manufacturing method of the solid electrolytic capacitor according to any one of claims 1 to 7, wherein the first wall portion and the second wall portion have at least one gap.

9. A solid electrolytic capacitor comprising: a plurality of flat film-shaped capacitor elements in which a dielectric layer and a solid electrolyte layer are sequentially formed on the surface of a flat film-shaped anode electrode foil; an anode through-hole penetrating the plurality of flat film-shaped capacitor elements in the thickness direction; a flat film-shaped cathode electrode foil; a cathode through-hole penetrating the flat film-shaped cathode electrode foil in the thickness direction; a sheet laminate formed by alternately laminating the plurality of flat film-shaped capacitor elements and the flat film-shaped cathode electrode foil via the solid electrolyte layer, the sheet laminate having a top surface, a bottom surface facing the top surface, and side surfaces connecting the top surface and the bottom surface; a first resin layer having a space for accommodating the sheet laminate; and a second resin layer for sealing the sheet laminate together with the first resin layer.

Images