Method for manufacturing solid electrolytic capacitor, and solid electrolytic capacitor

Abstract

Provided is a method for manufacturing a solid electrolytic capacitor by: laminating a first sheet and a second sheet, the first sheet being provided with a valve-acting metal substrate with a porous portion, a dielectric layer, and a solid electrolyte layer and having formed therein a first through-hole of a width equal to or greater than the width of an element region so as to straddle a first end, and a second through-hole of a width smaller than the width of the element region so as to straddle a second end, the second sheet being provided with a metal foil and having formed therein a third through-hole of a width smaller than the width of the element region so as to straddle the first end, and a fourth through-hole of a width equal to or greater than the width of the element region so as to straddle the second end, and the first and second sheets being laminated in a manner in which the first through-hole and the third through-hole are in communication, and the second through-hole and the fourth through-hole are in communication; filling the first to fourth through-holes with a sealing material; and cutting a first side part and a second side part with a guillotine blade while applying ultrasonic vibrations.

Description

Method for manufacturing a solid electrolytic capacitor and solid electrolytic capacitor

[0001] The present invention relates to a method for manufacturing a solid electrolytic capacitor and a solid electrolytic capacitor.

[0002] Patent Document 1 describes a method for manufacturing a solid electrolytic capacitor and a solid electrolytic capacitor. The method for manufacturing a solid electrolytic capacitor described in Patent Document 1 includes: (A) a step of preparing a first sheet; (B) a step of preparing a second sheet; (C) a step of coating the first sheet with an insulating material; (D) a step of forming a conductor layer on the first sheet; (E) a step of producing a laminated sheet; (F) a step of producing a laminated block body; (G) a step of producing a plurality of element laminate bodies by cutting the laminated block body; and (H) a step of forming a first external electrode and a second external electrode.

[0003] Patent Document 2 describes a technique for cutting a current collector foil of a laminated secondary battery using an ultrasonic cutting device.

[0004] Patent Document 3 describes a solid electrolytic capacitor. The solid electrolytic capacitor described in Patent Document 3 is configured by laminating capacitor elements on a mounting surface of a terminal board. In the capacitor element, a separation portion for separating an anode lead-out portion and a cathode lead-out portion is formed at a boundary between them, and the separation portion is formed by applying an insulating resin after an etching process and allowing it to penetrate into a corresponding portion in the etching layer.

[0005] Japanese Unexamined Patent Application Publication No. 2019-79866, Japanese Unexamined Patent Application Publication No. 2018-094685, Japanese Unexamined Patent Application Publication No. 2012-182291

[0006] In the method for manufacturing a solid electrolytic capacitor formed by printing and lamination as in Patent Document 1, it is desirable that the width of the cut line for individualization be as narrow as possible. The cut portion is unnecessary, and in order to maximize the number and area of elements in one sheet, it is desirable to cut with a "line".

[0007] Therefore, when it comes to the cutting tools and cutting methods used, it is preferable to use something like a guillotine blade to cut in a "line" rather than cutting with a certain thickness, such as the dicing method or the dicing blades used in it.

[0008] Furthermore, dicing and laser processing methods have long cycle times and are inefficient. This is especially true for thicker aluminum sheets that are laminated.

[0009] Regarding the cutting of metal foil using a guillotine blade, Patent Document 2 describes cutting a uniform current-collecting foil of an electrochemical device with a cutting blade, but this cannot be directly applied to cutting a laminate of a solid electrolytic capacitor that has a porous portion.

[0010] In solid electrolytic capacitors, the anode foil is formed with porous parts such as an etched layer. For example, it has a composite structure of a thin etched aluminum material and a cavity. If it is simply cut with a guillotine blade, the aluminum material may not be able to withstand the cutting force, potentially causing collapse or cracking. Furthermore, the fragments of the collapsed porous part are sufficiently large relative to the interlayer distance (e.g., 10 μm or more), bridging the anode and cathode foils and causing a short circuit. Therefore, efficient sheet cutting of "lines" is not possible unless porous parts such as the etched layer are cut without collapse.

[0011] The present invention was made to solve the above problems and aims to provide a method for manufacturing solid electrolytic capacitors that can be efficiently separated into individual pieces while suppressing the collapse of the porous portion. The present invention also aims to provide solid electrolytic capacitors manufactured by the above manufacturing method.

[0012] The method for manufacturing a solid electrolytic capacitor of the present invention comprises the following steps: (A) Step of preparing a first sheet; The first sheet comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer; Furthermore, the first sheet has a plurality of element regions, each element region is partitioned by a first end and a second end opposite to each other in the length direction, and a first side and a second side opposite to each other in the width direction; Furthermore, the first sheet has a first through hole formed so as to straddle the first end of each element region and having a width greater than or equal to the width of the element region, and one or more second through holes formed so as to straddle the second end of each element region and having a width less than the width of the element region; (B) Step of preparing a second sheet; The second sheet is made of metal foil; Furthermore, the second sheet has a plurality of element regions, each element region is demarcated by a first end and a second end facing each other in the length direction, and a first side and a second side facing each other in the width direction, and furthermore, the second sheet has one or more third through holes formed thereon that straddle the first end of each element region and have a width smaller than the width of the element region, and a fourth through hole formed thereon that straddles the second end of each element region and has a width greater than or equal to the width of the element region, (C) Step of manufacturing a laminated sheet; (C) Step is to laminate the first sheet and the second sheet so that the first ends and second ends of each element region face each other, and furthermore, in the laminated sheet, the first through hole and the third through hole, and the second through hole and the fourth through hole are in communication in the lamination direction, (D) Step of manufacturing a laminated block body as necessary; (D) In ​​step (D), a sealing material is filled into the first through hole and the third through hole, and the second through hole and the fourth through hole, respectively, from at least one of the first and second main surfaces of the laminated sheet that are opposite each other in the lamination direction; (E) A step of manufacturing a plurality of element laminates by cutting the laminated sheet or the laminated block;(E) In step (E), the laminated sheet or laminated block is cut at the positions of the first and second ends of each element region, and is also cut along the first and second sides of each element region with a guillotine blade while applying ultrasonic vibration; (F) A step of forming a first external electrode and a second external electrode on the element laminate.

[0013] The solid electrolytic capacitor of the present invention, in a first embodiment, comprises an element stack, a first external electrode, and a second external electrode, wherein the element stack comprises a first layer and a second layer, the first layer comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer, the second layer is made of metal foil, further comprising the element stack, of the first and second end faces facing each other in the longitudinal direction, the metal foil and the first sealing portion are exposed on the first end face, the valve-acting metal substrate and the second sealing portion are exposed on the second end face, the first external electrode is provided on the first end face of the element stack and connected to the metal foil, and the second external electrode is provided on the second end face of the element stack and connected to the valve-acting metal substrate. In the above-described element stack, the first layer has a region in which the porous portion is coined along a first side surface and a second side surface that are opposite to each other in the width direction.

[0014] In a second embodiment, the solid electrolytic capacitor of the present invention comprises an element stack, a first external electrode, and a second external electrode, wherein the element stack consists of a first layer and a second layer, the first layer comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer, the second layer consists of a metal foil, further comprising the first end face and the second end face of the element stack, with the metal foil and the first sealing portion exposed on the first end face and the valve-acting metal substrate and the second sealing portion exposed on the second end face, the first external electrode is provided on the first end face of the element stack and connected to the metal foil, and the second external electrode is provided on the second end face of the element stack and connected to the valve-acting metal substrate. In the above-described element stack, the first layer has a region from which the porous portion has been removed along a first side surface and a second side surface that are opposite to each other in the width direction.

[0015] According to the present invention, it is possible to provide a method for manufacturing solid electrolytic capacitors that can efficiently be separated into individual pieces while suppressing the collapse of the porous portion. Furthermore, according to the present invention, it is possible to provide solid electrolytic capacitors manufactured by the above manufacturing method.

[0016] Figure 1A is a schematic perspective view showing an example of a first sheet, and Figure 1B is a perspective view showing an enlarged portion of Figure 1A. Figure 2A is a schematic perspective view showing an example of a second sheet, and Figure 2B is a perspective view showing an enlarged portion of Figure 2A. Figure 3A is a schematic perspective view showing an example of the state before the first and second sheets are laminated, and Figure 3B is a perspective view showing an example of a laminated sheet. Figure 4A is a schematic perspective view showing an example of a laminated block, and Figure 4B is a perspective view showing an enlarged, exploded portion of Figure 4A. Figure 5A is a schematic plan view showing a valve-acting metal substrate before cutting, and Figure 5B is a schematic plan view showing a valve-acting metal substrate after cutting. Figure 6A is a schematic plan view showing a metal foil before cutting, and Figure 6B is a schematic plan view showing a metal foil after cutting. Figure 7 is a schematic cross-sectional view showing an example of an element laminate. Figures 8A and 8B are schematic perspective views showing an example of an element stack. Figure 9A is a schematic perspective view showing an example of a stacked block after cutting, and Figure 9B is a perspective view showing a part of Figure 9A that has been disassembled and enlarged. Figure 10A is a schematic perspective view showing an example of a stacked block with a fourth sealing portion formed thereon, and Figure 10B is a perspective view showing a part of Figure 10A that has been disassembled and enlarged. Figure 11A is a schematic perspective view showing an example of a fragmented element stack, and Figure 11B is a perspective view showing a part of Figure 11A that has been disassembled and enlarged. Figure 12 is a schematic cross-sectional view showing an example of a solid electrolytic capacitor. Figures 13A and 13B are schematic perspective views showing an example of a solid electrolytic capacitor manufactured by the manufacturing method of a solid electrolytic capacitor according to the first embodiment of the present invention. Figure 14A is a schematic perspective view showing an example of a coined first sheet, and Figure 14B is a perspective view showing a part of Figure 14A that has been enlarged. Figure 15A is a schematic perspective view showing an example of a first sheet in which an insulating resin layer is formed in a coined region, and Figure 15B is an enlarged perspective view of a part of Figure 15A. Figures 16A and 16B are schematic perspective views showing an example of a solid electrolytic capacitor according to the third embodiment of the present invention. Figures 17A and 17B are schematic perspective views showing an example of a solid electrolytic capacitor according to the fourth embodiment of the present invention.Figure 18A is a schematic perspective view showing an example of a laser-processed first sheet, and Figure 18B is an enlarged perspective view of a part of Figure 18A. Figure 19A is a schematic perspective view showing an example of a first sheet in which an insulating resin layer has been formed in the region where the porous portion has been removed by laser, and Figure 19B is an enlarged perspective view of a part of Figure 19A. Figures 20A and 20B are schematic perspective views showing an example of a solid electrolytic capacitor according to the fifth embodiment of the present invention. Figures 21A and 21B are schematic perspective views showing an example of a solid electrolytic capacitor according to the sixth embodiment of the present invention. Figure 22 is a schematic perspective view showing an example of a laminated sheet after cutting. Figure 23 is a schematic perspective view showing an example of the structure of a resin substrate. Figure 24A is a schematic perspective view showing an example of a structure in which strip-shaped laminated sheets are arranged on a resin substrate, and Figure 24B is a cross-sectional view taken along line A-A in Figure 24A. Figure 25 is a schematic cross-sectional view showing an example of a state in which strip-shaped laminated sheets are sealed. Figure 26A is a schematic perspective view showing an example of a strip-shaped laminated sheet sealed with insulating resin, and Figure 26B is a schematic perspective view showing an example of a laminated sheet separated into individual pieces.

[0017] The method for manufacturing a solid electrolytic capacitor and the solid electrolytic capacitor of the present invention will be described below. However, the present invention is not limited to the following configurations and can be modified and applied as appropriate without changing the gist of the invention. Furthermore, a combination of two or more of the individual desirable configurations of the present invention described below also constitutes the present invention.

[0018] The embodiments described below are illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the second and subsequent embodiments, descriptions of matters common to the first embodiment will be omitted, and only the differences will be explained. In particular, similar effects and advantages due to similar configurations will not be mentioned sequentially for each embodiment.

[0019] (First Embodiment) [Method for Manufacturing a Solid Electrolytic Capacitor] An example of a method for manufacturing a solid electrolytic capacitor according to the first embodiment of the present invention will be described step by step below.

[0020] (A) Steps for preparing the first sheet First, the first sheet is prepared. The first sheet comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer. Furthermore, the first sheet has a plurality of element regions. In the first sheet, each element region is demarcated by a first end and a second end that are opposite in the length direction, and a first side and a second side that are opposite in the width direction perpendicular to the length direction. Furthermore, the first sheet has a first through hole formed so as to straddle the first end of each element region and having a width greater than or equal to the width of the element region, and one or more second through holes formed so as to straddle the second end of each element region and having a width less than the width of the element region.

[0021] Figure 1A is a schematic perspective view showing an example of the first sheet, and Figure 1B is a perspective view that is an enlarged portion of Figure 1A. The first sheet 10 shown in Figures 1A and 1B has a plurality of element regions R11 (hereinafter referred to as the first element region) and a plurality of element regions R12 (hereinafter referred to as the second element region).

[0022] As shown in Figure 1B, the first element region R11 is divided by a first end E11 and a second end E12 that are opposite each other in the length direction (L direction), and a first side S11 and a second side S12 that are opposite each other in the width direction (W direction) perpendicular to the length direction. The dimension of the first element region R11 in the length direction (L direction) is greater than the dimension in the width direction (W direction). One first through hole H1 is formed so as to straddle the first end E11 of the first element region R11 in the length direction, and a plurality of second through holes H2 (three in Figure 1B) are formed so as to straddle the second end E12 of the first element region R11 in the length direction. The first through hole H1 consists of one elongated hole with a width greater than or equal to the width of the first element region R11, and the second through holes H2 consist of a plurality of substantially round holes with a width less than the width of the first element region R11.

[0023] On the other hand, the second element region R12 has the same shape as the first element region R11, but the orientation of the first end E11 and the second end E12 is opposite to that of the first element region R11.

[0024] As shown in Figure 1A, in the first sheet 10, first element regions R11 and second element regions R12 are arranged alternately in the longitudinal direction. As shown in Figure 1B, the first element region R11 shares a first end E11 and a first through hole H1 with an adjacent second element region R12, and shares a second end E12 and a second through hole H2 with another adjacent second element region R12.

[0025] Furthermore, as shown in Figure 1A, in the first sheet 10, the first element region R11 and the second element region R12 are arranged alternately in the width direction. As shown in Figure 1B, the first element region R11 shares a first side portion S11 with an adjacent second element region R12, and also shares a second side portion S12 with another adjacent second element region R12.

[0026] As shown in Figure 1B, the first sheet 10 comprises a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion 12, and solid electrolyte layers 13 provided inside each element region on the dielectric layer. In the first sheet 10, the ends and sides of each element region may be covered with an insulating resin layer 14, and the solid electrolyte layer 13 may be provided in the region surrounded by the insulating resin layer 14.

[0027] In the first sheet 10 shown in Figure 1B, the valve-acting metal substrate 11 has porous portions 12 on both sides, with a dielectric layer formed on the surface of each porous portion 12, and a solid electrolyte layer 13 provided on the dielectric layer. However, if the second sheet is not laminated on one side of the first sheet, a solid electrolyte layer does not need to be provided on the surface of the valve-acting metal substrate on the side where the second sheet (metal foil) is not laminated. In this case, a dielectric layer may not be formed on the surface of the valve-acting metal substrate on the side where the second sheet (metal foil) is not laminated, nor may a porous portion be formed. Alternatively, the first sheet 10 may be one in which the valve-acting metal substrate 11 has a porous portion 12 on only one side, with a dielectric layer formed on the surface of the porous portion 12.

[0028] The first sheet is preferably manufactured as follows. First, a valve-acting metal substrate 11 having a porous portion 12 on its surface is prepared, and a dielectric layer is formed on the surface of the porous portion 12. For example, when aluminum foil is used as the valve-acting metal substrate, a dielectric layer consisting of an oxide film can be formed by performing an anodic oxidation treatment (also called a chemical conversion treatment) on the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like.

[0029] The valve-acting metal substrate consists of a valve-acting metal that exhibits so-called valve action. Examples of valve-acting metals include elemental metals such as aluminum, tantalum, niobium, titanium, and zirconium, or alloys containing these metals. Among these, aluminum or aluminum alloys are preferred.

[0030] The shape of the valve metal substrate is preferably flat, and more preferably foil-shaped. The porous portion can be formed by etching the surface of the valve metal substrate, or by printing valve metal powder of the same or different type as the valve metal substrate onto the surface of the valve metal substrate and sintering as necessary. When the valve metal is aluminum or an aluminum alloy, it is preferable to form the porous portion by etching, and when the valve metal is any other, it is preferable to form the porous portion by printing valve metal powder and sintering as necessary.

[0031] The thickness of the valve-acting metal substrate is not particularly limited, but the thickness of the portion excluding the porous part is preferably 5 μm or more and 100 μm or less. Furthermore, the thickness of the porous part (thickness on one side) is preferably 5 μm or more and 200 μm or less.

[0032] The dielectric layer formed on the surface of the porous portion is porous, reflecting the surface state of the porous portion, and has a fine, uneven surface shape. Preferably, the dielectric layer is made of an oxide film of the valve-acting metal.

[0033] Furthermore, from the viewpoint of improving manufacturing efficiency, a chemical conversion foil that has been pre-treated with chemical conversion may be used as the valve-acting metal substrate on which the dielectric layer is formed on the surface.

[0034] Next, an insulating resin layer 14 may be formed by filling the porous portion 12 in the first side portion S11 and the second side portion S12 of each element region with an insulating resin material. At this time, the insulating resin layer 14 may also be formed at the first end portion E11 and the second end portion E12 of each element region by filling them with an insulating resin material.

[0035] The insulating resin layer 14 is formed, for example, by applying an insulating resin material to the surface of the valve-acting metal substrate and solidifying or hardening it by heating or the like. The insulating resin material is preferably applied by screen printing, dispenser application, inkjet printing, or the like.

[0036] The insulating resin material includes at least a resin. Examples of resins in the insulating resin material include polyimide resin and epoxy resin.

[0037] The insulating resin material may or may not contain fillers, or it may contain a very small amount of fillers. The absence of fillers makes it easier to fill the porous portion with the insulating resin material. When a very small amount of filler is included, the insulating resin layer 14 can be reinforced. Examples of fillers included in the insulating resin material include silica particles, alumina particles, and other metal oxide particles.

[0038] Next, a solid electrolyte layer 13 is formed inside each element region on the dielectric layer. In this case, the solid electrolyte layer 13 may be formed in the region surrounded by the insulating resin layer 14. For example, a solid electrolyte layer can be formed in a predetermined region by applying the following processing liquid or dispersion onto the dielectric layer by sponge transfer, screen printing, dispenser, inkjet printing, etc.

[0039] The solid electrolyte layer is formed, for example, by using a treatment solution containing a monomer such as 3,4-ethylenedioxythiophene to form a polymerized film such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer, or by applying a dispersion of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer and drying it. It is preferable to form the solid electrolyte layer by first forming an inner layer that fills the pores (recesses) of the dielectric layer, and then forming an outer layer that covers the dielectric layer.

[0040] Examples of materials constituting the solid electrolyte layer include conductive polymers such as polypyrroles, polythiophenes, and polyanilines. Among these, polythiophenes are preferred, and poly(3,4-ethylenedioxythiophene) called PEDOT is particularly preferred. Furthermore, the conductive polymer may contain dopants such as polystyrene sulfonic acid (PSS).

[0041] Subsequently, a first through-hole H1 is formed so as to straddle the first end E11 of each element region, and a second through-hole H2 is formed so as to straddle the second end E12 of each element region. The first and second through-holes are formed, for example, by laser processing, etching, punching, etc.

[0042] The first through-hole H1 and the second through-hole H2 may be formed before forming the insulating resin layer 14, or before forming the solid electrolyte layer 13.

[0043] The size of the entire first sheet is determined by the size, shape, number, arrangement, production capacity, etc. of the element regions and is not particularly limited. The shape of the element region of the first sheet is not particularly limited, but is preferably rectangular. In this case, the first end portion and the second end portion may be shorter or longer than the first side portion and the second side portion.

[0044] From the viewpoint of manufacturing efficiency, the first sheet has a plurality of element regions. In particular, it is preferable that the first sheet has a first element region and a second element region, and the first element region and the second element region are alternately arranged in the length direction, and it is more preferable that the first element region and the second element region are alternately arranged in the width direction. When the first element region and the second element region are alternately arranged, the first through holes do not tend to be unevenly distributed in the width direction of the first sheet, so the strength of the sheet is less likely to decrease.

[0045] In the first sheet, when the first element region and the second element region are alternately arranged in the length direction, the first element region preferably shares the first end portion and the first through hole with the adjacent second element region, and also shares the second end portion and the second through hole with another adjacent second element region. In this case, the number of cutting times for dividing the element region and the portion to be discarded can be reduced.

[0046] However, when the first sheet has a first element region and a second element region, the first element region and the second element region may not be alternately arranged in the length direction, nor may they be alternately arranged in the width direction. Also, when the first element region and the second element region are alternately arranged in the length direction, the first element region does not necessarily have to share the first end portion and the first through hole with the adjacent second element region, nor does it have to share the second end portion and the second through hole with another adjacent second element region. Further, when the first element region and the second element region are alternately arranged in the width direction, the first element region does not necessarily have to share the first side portion with the adjacent second element region, nor does it have to share the second side portion with another adjacent second element region.

[0047] The shape of the first through-hole is not particularly limited as long as it has a width equal to or greater than the width of the element region.

[0048] The shape, number, arrangement, etc. of the second through-holes are not particularly limited as long as they have a width smaller than the width of the element region. However, in each element region, it is preferable that two or more are formed in the width direction. When two or more second through-holes are formed, it is preferable that these through-holes are formed at equal intervals. In addition, if the width of each second through-hole is too small, it becomes difficult to fill the sealing material in the process described later. On the other hand, if the ratio of the total width of the second through-holes to the width of the element region is too large, the ratio of the valve action metal substrate exposed on the end face of the solid electrolytic capacitor becomes small, so the ESR tends to increase.

[0049] (B) Step of preparing the second sheet Separately, prepare the second sheet. The second sheet is made of a metal foil. Further, the second sheet has a plurality of element regions. In the second sheet, each element region is defined by a first end portion and a second end portion opposing in the length direction, and a first side portion and a second side portion opposing in the width direction orthogonal to the length direction. Further, in the second sheet, one or more third through-holes having a width smaller than the width of the element region are formed so as to straddle the first end portion of each element region, and a fourth through-hole having a width equal to or greater than the width of the element region is formed so as to straddle the second end portion of each element region.

[0050] FIG. 2A is a perspective view schematically showing an example of the second sheet, and FIG. 2B is an enlarged perspective view of a part of FIG. 2A. The second sheet 20 shown in FIGS. 2A and 2B has a plurality of element regions R21 (hereinafter referred to as first element regions) and a plurality of element regions R22 (hereinafter referred to as second element regions).

[0051] As shown in Figure 2B, the first element region R21 is divided by a first end E21 and a second end E22 that are opposite to each other in the length direction (L direction), and a first side S21 and a second side S22 that are opposite to each other in the width direction (W direction) perpendicular to the length direction. Multiple third through holes H3 (three in Figure 2B) are formed so as to straddle the first end E21 of the first element region R21 in the length direction, and one fourth through hole H4 is formed so as to straddle the second end E22 of the first element region R21 in the length direction. The third through holes H3 consist of multiple substantially round holes with a width smaller than the width of the first element region R21, and the fourth through hole H4 consists of one elongated hole with a width greater than or equal to the width of the first element region R21.

[0052] On the other hand, the second element region R22 has the same shape as the first element region R21, but the orientation of the first end E21 and the second end E22 is opposite to that of the first element region R21.

[0053] As shown in Figure 2A, in the second sheet 20, the first element region R21 and the second element region R22 are arranged alternately in the longitudinal direction. As shown in Figure 2B, the first element region R21 shares a first end E21 and a third through hole H3 with the adjacent second element region R22, and shares a second end E22 and a fourth through hole H4 with another adjacent second element region R22.

[0054] Furthermore, as shown in Figure 2A, in the second sheet 20, the first element region R21 and the second element region R22 are arranged alternately in the width direction. As shown in Figure 2B, the first element region R21 shares a first side portion S21 with an adjacent second element region R22, and also shares a second side portion S22 with another adjacent second element region R22.

[0055] As shown in Figure 2B, the second sheet 20 is made of metal foil 21.

[0056] The second sheet is preferably prepared as follows. First, a metal foil 21 is prepared.

[0057] The metal foil is preferably made of at least one metal selected from the group consisting of aluminum, copper, silver, and alloys mainly composed of these metals. When the metal foil is made of the above metals, the resistance value of the metal foil can be reduced, and the ESR can be reduced.

[0058] Furthermore, metal foils with a carbon coating or titanium coating applied to the surface by film deposition methods such as sputtering or vapor deposition may also be used.

[0059] The thickness of the metal foil is not particularly limited, but from the viewpoint of reducing ESR, it is preferable that it be between 5 μm and 100 μm.

[0060] It is preferable that a roughened surface is formed on the surface of the metal foil. When a roughened surface is formed on the surface of the metal foil, the adhesion between the metal foil and the solid electrolyte layer, or between the metal foil and other conductive layers, is improved, and the contact area is increased, thereby reducing ESR. The method for forming the roughened surface is not particularly limited, and it may be formed by etching or the like. In particular when using aluminum, it is preferable to apply a carbon coating or titanium coating to a surface that has been roughened (etched) in order to reduce resistance.

[0061] Furthermore, a coating layer made of an anchor coating agent may be formed on the surface of the metal foil. When a coating layer made of an anchor coating agent is formed on the surface of the metal foil, the adhesion between the metal foil and the solid electrolyte layer, or the adhesion between the metal foil and other conductive layers, is improved, thereby reducing ESR.

[0062] Next, a third through-hole H3 is formed so as to straddle the first end E21 of each element region, and a fourth through-hole H4 is formed so as to straddle the second end E22 of each element region. The third and fourth through-holes are formed, for example, by laser processing, etching, punching, etc.

[0063] The overall size of the second sheet is not particularly limited, but it is preferable that it be the same as the overall size of the first sheet. The shape, number, and arrangement of the element regions of the second sheet are preferably the same as the shape, number, and arrangement of the element regions of the opposing first sheet.

[0064] The second sheet has multiple element regions from the viewpoint of manufacturing efficiency. In particular, it is preferable that the second sheet has a first element region and a second element region, with the first and second element regions being alternately arranged in the length direction, and it is even more preferable that the first and second element regions are also alternately arranged in the width direction. When the first and second element regions are alternately arranged, the fourth through-holes are not unevenly distributed in the width direction of the second sheet, so the strength of the sheet is less likely to decrease.

[0065] In the second sheet, when the first element regions and the second element regions are arranged alternately in the longitudinal direction, it is preferable that the first element region shares a first end and a third through-hole with an adjacent second element region, and also shares a second end and a fourth through-hole with another adjacent second element region. In this case, the number of cuts required to divide the element region and the amount of material to be discarded can be reduced.

[0066] However, if the second sheet has a first element region and a second element region, the first element region and the second element region do not have to be alternately arranged in the length direction, nor do they have to be alternately arranged in the width direction. Also, if the first element region and the second element region are alternately arranged in the length direction, the first element region does not have to share a first end and a third through hole with an adjacent second element region, nor does it have to share a second end and a fourth through hole with another adjacent second element region. Furthermore, if the first element region and the second element region are alternately arranged in the width direction, the first element region does not have to share a first side with an adjacent second element region, nor does it have to share a second side with another adjacent second element region.

[0067] The shape, number, and arrangement of the third through-holes are not particularly limited, as long as they have a width smaller than the width of the element region, but it is preferable that two or more are formed in the width direction within each element region. When two or more third through-holes are formed, it is preferable that these through-holes are formed at equal intervals. If the width of each third through-hole is too small, it becomes difficult to fill with sealing material in the process described later, while if the ratio of the total width of the third through-holes to the width of the element region is too large, the proportion of metal foil exposed on the end face of the solid electrolytic capacitor decreases, which tends to increase the ESR.

[0068] The shape of the fourth through-hole is not particularly limited, as long as it has a width greater than or equal to the width of the element region.

[0069] (C) Process for manufacturing a laminated sheet A laminated sheet is manufactured by stacking a first sheet and a second sheet such that the first ends and second ends of each element region face each other. In the resulting laminated sheet, the first through hole and the third through hole, and the second through hole and the fourth through hole are in communication in the stacking direction.

[0070] Preferably, the second and third through holes are linearly connected from the first main surface of the laminated sheet toward the second main surface.

[0071] When laminating the first sheet and the second sheet, the valve-acting metal substrate and the metal foil are connected without interposing other conductive layers of the solid electrolyte layer. In this way, by laminating the first sheet and the second sheet without using adhesive, the thickness of the solid electrolytic capacitor can be reduced. However, if the adhesive does not affect the thickness of the solid electrolytic capacitor, the first sheet and the second sheet may be bonded together using an adhesive.

[0072] When laminating the first sheet and the second sheet, it is preferable to place the metal foil on the layer located beneath it while it is still viscous. The solid electrolyte layer is viscous before drying, making it suitable for direct placement of the metal foil. On the other hand, if the solid electrolyte layer located beneath the metal foil is dried, it becomes difficult to adhere the metal foil, so it is preferable to place a conductive adhesive layer (for example, a solid electrolyte layer containing a binder) before placing the metal foil.

[0073] Figure 3A is a schematic perspective view showing an example of the state before the first sheet and the second sheet are laminated, and Figure 3B is a schematic perspective view showing an example of a laminated sheet. As shown in Figure 3A, the laminated sheet 30 shown in Figure 3B is obtained by alternately laminating the first sheet 10 and the second sheet 20. The laminated sheet 30 has a first main surface M31 and a second main surface M32 that are opposite each other in the lamination direction (T direction).

[0074] Figures 3A and 3B show an example in which five sheets each of the first sheet 10 and the second sheet 20 are laminated, with the second sheet 20 placed on the first main surface M31 and the first sheet 10 on the second main surface M32 of the laminated sheet 30. However, the number of first and second sheets to be laminated is not particularly limited. The number of first sheets and second sheets may be the same or different. Therefore, either the first sheet or the second sheet may be placed on the main surface of the laminated sheet. Furthermore, when manufacturing the laminated sheet, the first and second sheets may be laminated on a substrate made of glass epoxy resin or the like.

[0075] (D) Steps for manufacturing a laminated block A laminated block is manufactured by filling the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole, from at least one main surface side of the obtained laminated sheet with sealing material.

[0076] As described above, in the laminated sheet, the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole are in communication in the lamination direction, so that sealing material can be filled into each through-hole from the main surface side of the laminated sheet. As a result, in the resulting laminated block, a first sealing portion is formed that fills the first through-hole and the third through-hole, and a second sealing portion is formed that fills the second through-hole and the fourth through-hole.

[0077] The sealing material can be filled by, for example, a molding resin molding method. In this case, in addition to the first sealing portion and the second sealing portion, a third sealing portion that covers at least one main surface of the laminated sheet can be formed at the same time. Thus, in the step of manufacturing the laminated block (D), it is preferable to simultaneously perform the step of covering at least one main surface of the laminated sheet with the sealing material.

[0078] Figure 4A is a schematic perspective view showing an example of a laminated block body, and Figure 4B is an enlarged perspective view of a part of Figure 4A that has been disassembled. In the laminated block body 40 shown in Figure 4A, by filling the first through hole and the third through hole, and the second through hole and the fourth through hole with sealing material, a first sealing portion 131 that fills the first through hole H1 and the third through hole H3, and a second sealing portion 132 that fills the second through hole H2 and the fourth through hole H4 are formed, as shown in Figure 4B. Furthermore, as shown in Figure 4A, the laminated block body 40 also includes a third sealing portion 133 that covers each main surface.

[0079] The encapsulant comprises at least a resin, preferably a resin and a filler. Examples of resins included in the encapsulant include epoxy resins and phenolic resins. Examples of fillers included in the encapsulant include metal oxide particles such as silica particles and alumina particles.

[0080] When the sealing material includes resin and filler, it is preferable that the maximum diameter of the filler be smaller than the minimum diameter of the second and third through holes, from the viewpoint of ensuring the sealing material's filling capacity. The diameter of the through hole refers to the diameter if the cross-sectional shape is circular, or the maximum length passing through the center of the cross-section if the cross-sectional shape is not circular.

[0081] Furthermore, when the sealing material includes resin and filler, it is preferable that the maximum diameter of the filler be smaller than the minimum thickness of the metal foil, from the viewpoint of ensuring the sealing material's filling properties.

[0082] The maximum diameter of the filler contained in the sealing material is preferably in the range of, for example, 30 μm or more and 40 μm or less.

[0083] However, the step of (D) manufacturing the laminated block is optional. That is, in the first embodiment, the laminated block is manufactured as needed.

[0084] (E) Process for producing multiple element stacks by cutting a stacked block: A stacked block is cut at the positions of the first end and the second end of each element region, and also at the positions of the first side and the second side of each element region, thereby producing multiple element stacks.

[0085] Figure 5A is a schematic plan view showing the valve-acting metal substrate before cutting, and Figure 5B is a schematic plan view showing the valve-acting metal substrate after cutting. As shown in Figure 5A, the valve-acting metal substrate 11 constituting the first sheet included in the laminated block has a first sealing portion 131 that fills a first through hole H1 spanning the first end E11 of each element region, and a second sealing portion 132 that fills a second through hole H2 spanning the second end E12 of each element region.

[0086] Therefore, when the valve-acting metal substrate 11 is cut at the positions of the first end E11 and the second end E12 of each element region so as to separate the first sealing portion 131 and the second sealing portion 132 on both sides, as shown in Figure 5B, the first sealing portion 131 is exposed at the first end face E101, which is the cut surface on the first end E11 side, and the valve-acting metal substrate 11 is not exposed. On the other hand, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102, which is the cut surface on the second end E12 side.

[0087] Furthermore, when the valve-acting metal substrate 11 is cut at the positions of the first side portion S11 and the second side portion S12 of each element region, the valve-acting metal substrate 11 is exposed on both cut surfaces, as shown in Figure 5B.

[0088] Figure 6A is a schematic plan view showing the metal foil before cutting, and Figure 6B is a schematic plan view showing the metal foil after cutting. As shown in Figure 6A, the metal foil 21 constituting the second sheet included in the laminated block has a first sealing portion 131 that fills a third through hole H3 spanning the first end E21 of each element region, and a second sealing portion 132 that fills a fourth through hole H4 spanning the second end E22 of each element region.

[0089] Therefore, when the metal foil 21 is cut at the positions of the first end E21 and the second end E22 of each element region so as to separate the first sealing portion 131 and the second sealing portion 132 on both sides, as shown in Figure 6B, the metal foil 21 and the first sealing portion 131 are exposed at the first end face E101, which is the cut surface on the first end E21 side. On the other hand, the second sealing portion 132 is exposed at the second end face E102, which is the cut surface on the second end E22 side, and the metal foil 21 is not exposed.

[0090] Furthermore, when the metal foil 21 is cut at the positions of the first side portion S21 and the second side portion S22 of each element region, the metal foil 21 is exposed on both cut surfaces, as shown in Figure 6B.

[0091] As described above, by cutting the laminated block at the positions of the first and second ends of each element region, the metal foil and the first sealing portion can be exposed on the first end face of the resulting element laminate, and the valve-acting metal substrate and the second sealing portion can be exposed on the second end face.

[0092] Here, the laminated block is cut along the first and second sides of each element region with a guillotine blade while applying ultrasonic vibration. This allows the laminated block to be cut efficiently in a "line" while suppressing the collapse of the porous portion of the valve-acting metal substrate. Furthermore, since the collapse of the porous portion is suppressed, short circuits in the chip product can also be reduced.

[0093] Furthermore, when an insulating resin layer is formed by filling the porous portions in the first and second sides of each element region with an insulating resin material, the voids in the porous portions of the first and second sides are reduced or substantially eliminated. In addition, the insulating resin material reinforces the porous portions, and the resins within the original voids are also bonded together. Therefore, the collapse of the porous portions can be reduced more effectively.

[0094] Furthermore, even when an insulating resin layer is provided in this way, since the cutting is performed by applying ultrasonic vibrations, the frictional heat generated by the friction of the ultrasonic vibrations during cutting softens the resin, thereby reducing the cutting load.

[0095] Furthermore, since the cut surface can be coated with resin softened by frictional heat, the possibility of short circuits can be further reduced.

[0096] Furthermore, since both the metal foil and the valve-acting metal substrate are exposed at the cut surfaces obtained by cutting the laminated block at the positions of the first and second sides of each element region, it is preferable to form a fourth sealing portion that covers each side surface of the element laminate.

[0097] Furthermore, the method for cutting the laminated block at the first and second ends of each element region is not particularly limited. This is because, since either the metal foil or the valve-acting metal substrate is exposed at the cut surface obtained by cutting the laminated block at the first and second ends of each element region, even if the porous portion of the valve-acting metal substrate collapses, it will not lead to a short-circuit malfunction.

[0098] Figure 7 is a schematic cross-sectional view showing an example of an element stack. Figures 8A and 8B are schematic perspective views showing an example of an element stack. Note that Figure 7 is a cross-sectional view taken along line A-A of the element stack shown in Figure 8A.

[0099] In the element laminate 100 shown in Figures 7, 8A, and 8B, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, is laminated with a second layer 120 made of metal foil 21. The first layer 110 and the second layer 120 are laminated alternately along the lamination direction (T direction), but considering weather resistance such as moisture resistance and heat resistance, it is preferable that the second layer 120, which is metal foil, is located at the outermost layers (excluding the third sealing portion 133) opposite each other in the lamination direction, as shown in Figure 7. Note that the insulating resin layer 14 is omitted in Figures 7, 8A, and 8B.

[0100] As shown in Figures 7, 8A, and 8B, the element stack 100 has a first main surface M101 and a second main surface M102 that are opposite each other in the stacking direction (T direction), a first end surface E101 and a second end surface E102 that are opposite each other in the length direction (L direction) perpendicular to the stacking direction, and a first side surface S101 and a second side surface S102 that are opposite each other in the width direction (W direction) perpendicular to the stacking direction and the length direction.

[0101] As shown in Figures 7 and 8A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100. On the other hand, as shown in Figures 7 and 8B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed on the second end face E102 of the element stack 100. Although the dielectric layer is also exposed on the second end face E102 of the element stack 100, in the following description it will simply be stated as "the valve-acting metal substrate 11 and the second sealing portion 132 are exposed."

[0102] Furthermore, the element stack 100 includes a third sealing portion 133 that covers each main surface, and a fourth sealing portion 134 that covers each side surface.

[0103] The element stack is fabricated, for example, as follows:

[0104] First, the laminated block is cut along the first and second sides of each element region using a guillotine blade while applying ultrasonic vibrations.

[0105] Figure 9A is a schematic perspective view showing an example of a laminated block after cutting, and Figure 9B is an enlarged perspective view of a part of Figure 9A that has been disassembled. For example, as shown in Figures 9A and 9B, the laminated block 40 shown in Figure 4A is cut along the first and second sides of each element region with a guillotine blade 50 while applying ultrasonic vibration, thereby producing a laminated block 40a with a gap G formed along the first and second sides. The frequency of the ultrasonic vibration applied to the guillotine blade 50 is preferably 20 kHz or more and 40 kHz or less, and more preferably 25 kHz or more and 35 kHz or less. The blade length of the guillotine blade 50 is longer than the distance from one end to the other in the longitudinal direction (L direction) of the laminated block 40a, and the guillotine blade 50 cuts the laminated block 40a from one end to the other in the longitudinal direction (L direction) in one piece. In the laminated block 40a, as shown in Figure 9B, the metal foil 21 and the valve-acting metal substrate 11 are exposed on the cut surface revealed by the cutting. Furthermore, if an insulating resin layer 14 is provided, as shown in Figure 9B, the insulating resin layer 14 filled in the porous portion 12 of the valve-acting metal substrate 11 is exposed on the cut surface.

[0106] Although not shown in the figures, the thickness of the exposed portion of the metal foil 21 and the valve-acting metal substrate 11 (thickness in the T direction) is greater than the thickness of the unexposed portion of the metal foil 21 and valve-acting metal substrate 11, and may widen in a tapered shape both vertically and horizontally in the thickness direction.

[0107] Next, a sealing material is filled into the gaps formed in the laminated block. This forms a fourth sealing portion that fills the gaps. As the sealing material, for example, the sealing material used to form the first sealing portion and the second sealing portion can be used.

[0108] Figure 10A is a schematic perspective view showing an example of a laminated block body in which a fourth sealing portion is formed, and Figure 10B is a perspective view obtained by disassembling and enlarging a part of Figure 10A. By filling the gap G of the laminated block body 40a shown in Figure 9A with a sealing material, a laminated block body 40b is produced in which a fourth sealing portion 134 that fills the gap G is formed, as shown in Figures 10A and 10B.

[0109] Subsequently, the laminated block is cut at the positions of the first and second ends of each element region so as to separate the first sealing portion 131 and the second sealing portion 132 on both sides, and at the positions of the first and second sides of each element region so as to separate the fourth sealing portion 134 on both sides. This allows the element laminate to be separated into individual pieces, with the first and second sides insulated by the sealing portions. For cutting the laminated block at this time, methods such as dicing using a dicing blade, a guillotine blade without ultrasonic vibration, laser processing, or scribing can be applied, in addition to a guillotine blade with ultrasonic vibration. When laminating the first and second sheets on a substrate made of glass epoxy resin or the like, it is preferable to cut the substrate to a half-cut position in order to reliably cut the second sheet, which is a metal foil. By half-cutting, a stepped shape is created from the first and second sides of each element region to the substrate, and this stepped shape is filled with a part of the fourth sealing portion 134.

[0110] Figure 11A is a schematic perspective view showing an example of a fragmented element stack, and Figure 11B is a perspective view showing a part of Figure 11A disassembled and enlarged. The element stack 100 shown in Figure 11A is obtained by cutting the stacked block 40b shown in Figure 10A at the positions of the first end and the second end of each element region, and also at the positions of the first side and the second side of each element region. In this case, as shown in Figures 11A and 11B, the stacked block 40b is cut such that the cut surfaces that appear when cut at the positions of the first side and the second side constitute the fourth sealing portion 134.

[0111] (F) Step of forming the first and second external electrodes The first and second external electrodes are formed on the obtained element stack. In the first embodiment, the first external electrode is formed on the first end face and the second external electrode is formed on the second end face. A solid electrolytic capacitor is obtained by doing the above.

[0112] Figure 12 is a schematic cross-sectional view showing an example of a solid electrolytic capacitor. The solid electrolytic capacitor 1 shown in Figure 12 comprises an element stack 100 as shown in Figure 7, a first external electrode 141 provided on the first end face E101 of the element stack 100, and a second external electrode 142 provided on the second end face E102 of the element stack 100. The first external electrode 141 is connected to a metal foil 21 exposed on the first end face E101, and the second external electrode 142 is connected to a valve-acting metal substrate 11 exposed on the second end face E102.

[0113] The first and second external electrodes can be formed, for example, by plating, sputtering, immersion coating, printing, etc. In the case of plating, the plating layers can be a Zn-Ag-Ni layer, an Ag-Ni layer, a Ni layer, a Zn-Ni-Au layer, a Ni-Au layer, a Zn-Ni-Cu layer, a Ni-Cu layer, etc. It is preferable to further form plating layers on these plating layers in the order of, for example, a Cu plating layer, a Ni plating layer, and a Sn plating layer (or with some exceptions).

[0114] In the method for manufacturing a solid electrolytic capacitor according to the first embodiment of the present invention, when cutting the laminated block along the first and second sides of each element region, the laminated block can be cut in an efficient "line" while suppressing the collapse of the porous portion of the valve-acting metal substrate. Therefore, it is possible to efficiently separate the components while suppressing the collapse of the porous portion.

[0115] [Solid Electrolytic Capacitors] Next, we will describe the solid electrolytic capacitors obtained by the manufacturing method described above.

[0116] Figures 13A and 13B are schematic perspective views showing an example of a solid electrolytic capacitor manufactured by the manufacturing method of a solid electrolytic capacitor according to the first embodiment of the present invention. Figure 12 is a cross-sectional view taken along line A-A of the solid electrolytic capacitor shown in Figure 13A. The solid electrolytic capacitor 1 shown in Figures 13A and 13B comprises an element laminate 100, a first external electrode 141, and a second external electrode 142. In Figures 13A and 13B, a part of the element laminate 100, the first external electrode 141, and the second external electrode 142 are shown with dashed lines. Also, as in Figures 8A and 8B, the insulating resin layer 14 is omitted.

[0117] In the element laminate 100, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, is laminated with a second layer 120 made of metal foil 21.

[0118] As shown in Figure 13A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100.

[0119] On the other hand, as shown in Figure 13B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102 of the element stack 100.

[0120] (Second Embodiment) [Method for Manufacturing Solid Electrolytic Capacitors] In the method for manufacturing solid electrolytic capacitors according to the second embodiment of the present invention, the step of manufacturing the laminated block body (D) described in the first embodiment is omitted.

[0121] Therefore, in the second embodiment, in step (E), multiple element stacks are produced by cutting the laminated sheet. More specifically, multiple element stacks are produced by cutting the laminated sheet at the positions of the first and second ends of each element region, and by cutting the first and second sides of each element region with a guillotine blade while applying ultrasonic vibration.

[0122] In the second embodiment, after cutting the laminated sheet, a sealing material can be applied to the necessary locations on the end face of the element laminate.

[0123] In the first embodiment, the element laminate with the fourth sealing portion is manufactured in one piece by cutting the laminated block twice along the first and second sides of each element region. In contrast, in the second embodiment, the element laminate with the fourth sealing portion may be manufactured in one piece by cutting the laminated sheet twice along the first and second sides of each element region, or the fourth sealing portion may be formed by cutting the laminated sheet at the positions of the first and second sides of each element region and then applying a sealing material to each cut surface.

[0124] In the second embodiment, the method for forming the first external electrode and the second external electrode on the element stack in step (F) is not limited to the method described in the first embodiment. For example, resin electrodes containing Ag or Cu may be used as the first and second external electrodes. Lead terminals may also be connected to the first and second external electrodes.

[0125] As described above, a solid electrolytic capacitor can be obtained. In the method for manufacturing a solid electrolytic capacitor according to the second embodiment of the present invention, similar to the first embodiment, it is possible to efficiently create individual pieces while suppressing the collapse of the porous portion.

[0126] The solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0127] (Third Embodiment) In the method for manufacturing a solid electrolytic capacitor according to the third embodiment of the present invention, (A) the step of preparing a first sheet comprises the step of coining the first side and the second side of each element region.

[0128] Here, coining refers to a processing treatment in which a portion of the porous part of the valve-acting metal substrate is pressed and crushed, thereby reducing the volume of the porous cavity. Therefore, by coining the first and second sides of each element region, the voids in the porous parts of the first and second sides are crushed, resulting in the formation of a recess overall. However, the density of the crushed original porous parts increases, preventing collapse due to cutting in the first place.

[0129] Figure 14A is a schematic perspective view showing an example of a coined first sheet, and Figure 14B is an enlarged perspective view of a part of Figure 14A. In the first sheet 10A shown in Figures 1A and 1B, unlike the first sheet 10 shown in Figures 1A and 1B, the first side portion S11 and the second side portion S12 of each element region are coined. As a result, the porous portion 12 of the valve-acting metal substrate 11 is compressed in the thickness direction in a straight line along the first side portion S11 and the second side portion S12. Coined regions (recesses) 15 are provided in a stripe pattern in the length direction (L direction) across the entire first sheet 10A. Here, the porous portion 12 is provided on both sides of the valve-acting metal substrate 11, and the porous portion 12 on both sides is coined.

[0130] In addition, the extent to which the porous portion 12 is compressed in the coined region 15 is not particularly limited and can be set as appropriate. However, the thickness of the porous portion 12 (original porous portion) in the coined region 15 is preferably 5% or more and 90% or less, and more preferably 5% or more and 30% or less, compared to the thickness of the porous portion 12 in the non-coined region.

[0131] In the third embodiment, (A) the step of preparing the first sheet further comprises the step of forming an insulating resin layer by applying an insulating resin material to the coined region. Here, applying an insulating resin material to the coined region means covering the recesses formed by coining with the insulating resin material, and at the same time filling the remaining cavities in the original porous portion that was crushed by coining with the insulating resin material. This further suppresses collapse.

[0132] Figure 15A is a schematic perspective view showing an example of a first sheet in which an insulating resin layer is formed in a coined region, and Figure 15B is an enlarged perspective view of a part of Figure 15A. In the first sheet 10A shown in Figures 15A and 15B, an insulating resin layer 14 is formed by applying an insulating resin material to the coined region 15. The insulating resin layer 14 is filled into the remaining cavities of the original porous portion crushed by coining, and is also formed in the recesses formed by coining. As a result, the recesses formed by coining are covered with the insulating resin layer 14. The insulating resin layer 14 is provided in a stripe pattern in the length direction (L direction) across the entire first sheet 10A. The insulating resin layer 14 is also provided in the coined region 15 on both sides of the valve-acting metal substrate 11.

[0133] The method and material for forming the insulating resin layer 14 are the same as those described in the first embodiment, so a detailed explanation will be omitted.

[0134] In the third embodiment, (C) in the step of producing a laminated sheet, a laminated sheet is produced by laminating a first sheet and a second sheet, each having an insulating resin layer formed in the coined region.

[0135] The subsequent steps are the same as those of the first embodiment, the second embodiment, or the seventh embodiment described later. A solid electrolytic capacitor is obtained as a result.

[0136] According to the method for manufacturing a solid electrolytic capacitor as embodied in the third embodiment of the present invention, it is possible to efficiently create individual pieces while very effectively suppressing the collapse of the porous portion.

[0137] [Solid electrolytic capacitor] A solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0138] The solid electrolytic capacitor of the present invention comprises an element laminate in which a first layer and a second layer are stacked, a first external electrode provided on a first end face of the element laminate, and a second external electrode provided on a second end face of the element laminate.

[0139] The first layer of the element stack comprises a valve-acting metal substrate having a porous surface, a dielectric layer formed on the surface of the porous surface, and a solid electrolyte layer provided on the dielectric layer. The second layer consists of a metal foil. The metal foil and the first sealing portion are exposed at the first end face of the element stack, and the valve-acting metal substrate and the second sealing portion are exposed at the second end face. The first external electrode is connected to the metal foil exposed at the first end face, and the second external electrode is connected to the valve-acting metal substrate exposed at the second end face.

[0140] The basic configuration of the element stack, the first external electrode, and the second external electrode is as described in the [Method for Manufacturing a Solid Electrolytic Capacitor] of Embodiment 1 and Embodiment 3, so a detailed explanation will be omitted.

[0141] In the solid electrolytic capacitor according to the third embodiment of the present invention, the first layer of the element laminate is characterized in that, along the first and second sides facing each other in the width direction, the porous portion is coined.

[0142] Figures 16A and 16B are schematic perspective views showing an example of a solid electrolytic capacitor according to a third embodiment of the present invention. The solid electrolytic capacitor 1A shown in Figures 16A and 16B comprises an element stack 100A, a first external electrode 141, and a second external electrode 142. In Figures 16A and 16B, a portion of the element stack 100A, the first external electrode 141, and the second external electrode 142 are shown with dashed lines.

[0143] In the element laminate 100A, as in the first embodiment, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, is laminated with a second layer 120 made of metal foil 21.

[0144] As shown in Figure 16A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100A.

[0145] On the other hand, as shown in Figure 16B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102 of the element stack 100A.

[0146] As shown in Figure 16B, along the first side surface S101 and the second side surface S102 which are opposite in the width direction, the first layer 110 has a region 15 in which the porous portion 12 of the valve-acting metal substrate 11 is coined, and an insulating resin layer 14 is formed in the coined region 15.

[0147] Therefore, according to the solid electrolytic capacitor of the third embodiment of the present invention, short circuits caused by the collapse of the porous portion can be suppressed very effectively.

[0148] (Fourth Embodiment) In the method for manufacturing a solid electrolytic capacitor according to the fourth embodiment of the present invention, (A) the step of preparing the first sheet is the same as in the third embodiment in that it includes a step of coining the first side and the second side of each element region, but the step of applying an insulating resin material to the coined region is not performed. Even in this case, the density of the original porous portion that has been crushed by coining is increased, so it is possible to prevent collapse due to cutting in the first place.

[0149] In the fourth embodiment, (C) in the step of producing a laminated sheet, a laminated sheet is produced by laminating a first sheet and a second sheet, neither of which has an insulating resin material applied to the coined region.

[0150] The subsequent steps are the same as those of the first embodiment, the second embodiment, or the seventh embodiment described later. A solid electrolytic capacitor is obtained as a result.

[0151] According to the method for manufacturing a solid electrolytic capacitor as embodied in the fourth embodiment of the present invention, it is possible to efficiently separate the capacitor into individual pieces while effectively suppressing the collapse of the porous portion.

[0152] [Solid electrolytic capacitor] A solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0153] The solid electrolytic capacitor according to the fourth embodiment of the present invention is similar to the third embodiment in that, in the element stack, the first layer has a region in which the porous portion is coined along the first and second sides facing each other in the width direction, but an insulating resin material is not applied to the coined region.

[0154] Figures 17A and 17B are schematic perspective views showing an example of a solid electrolytic capacitor according to a fourth embodiment of the present invention. The solid electrolytic capacitor 1B shown in Figures 17A and 17B comprises an element stack 100B, a first external electrode 141, and a second external electrode 142. In Figures 17A and 17B, a portion of the element stack 100B, the first external electrode 141, and the second external electrode 142 are shown with dashed lines.

[0155] In the element laminate 100B, as in the first and third embodiments, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, is laminated with a second layer 120 made of metal foil 21.

[0156] As shown in Figure 17A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100B.

[0157] On the other hand, as shown in Figure 17B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102 of the element stack 100B.

[0158] As shown in Figure 17B, along the first side surface S101 and the second side surface S102, which are opposite each other in the width direction, the first layer 110 has a region 15 in which the porous portion 12 of the valve-acting metal substrate 11 is coined, but the coined region 15 is not coated with an insulating resin material. The coined region 15 is covered by a fourth sealing portion 134.

[0159] According to the solid electrolytic capacitor of the fourth embodiment of the present invention, short circuits caused by the collapse of the porous portion can be effectively suppressed.

[0160] (Fifth Embodiment) In the method for manufacturing a solid electrolytic capacitor according to the fifth embodiment of the present invention, (A) the step of preparing a first sheet includes the step of removing porous portions from the first and second sides of each element region using a laser. As a result, the amount of collapsing porous portions is reduced, thereby reducing problems caused by collapse.

[0161] Figure 18A is a schematic perspective view showing an example of a laser-processed first sheet, and Figure 18B is an enlarged perspective view of a part of Figure 18A. In the first sheet 10B shown in Figures 1A and 1B, unlike the first sheet 10 shown in Figures 1A and 1B, the porous portion 12 is removed by laser at the first side S11 and second side S12 of each element region. As a result, the porous portion 12 of the valve-acting metal substrate 11 is partially removed in a linear manner along the first side S11 and second side S12. In the entire first sheet 10B, regions (recesses) 16 from which the porous portion 12 has been removed by laser are provided in a stripe-like pattern in the length direction (L direction). Here, the porous portion 12 is provided on both sides of the valve-acting metal substrate 11, and the porous portion 12 on both sides is removed by laser.

[0162] In the region 16 where the porous portion 12 has been removed by the laser, the extent to which the porous portion 12 is removed is not particularly limited and can be set as appropriate. However, the thickness of the remaining porous portion 12 in the region 16 where the porous portion 12 has been removed by the laser is preferably 5% or more and 90% or less, and more preferably 5% or more and 30% or less, compared to the thickness of the porous portion 12 in the region where the porous portion 12 has not been removed by the laser.

[0163] In the fifth embodiment, (A) the step of preparing the first sheet further comprises the step of forming an insulating resin layer by applying an insulating resin material to the region where the porous portion has been removed by the laser. Here, applying an insulating resin material to the region where the porous portion has been removed by the laser means covering the recesses formed by the laser with the insulating resin material, and in doing so, filling the voids of the porous portion that remain even after laser removal with the insulating resin material. This further suppresses collapse.

[0164] Figure 19A is a schematic perspective view showing an example of a first sheet in which an insulating resin layer is formed in a region where the porous portion has been removed by a laser, and Figure 19B is an enlarged perspective view of a part of Figure 19A. In the first sheet 10B shown in Figures 19A and 19B, an insulating resin layer 14 is formed by applying an insulating resin material to the region 16 in which the porous portion 12 has been removed by a laser. The insulating resin layer 14 fills the cavities of the porous portion 12 that remain after laser removal and is also formed in the recesses formed by the laser. As a result, the recesses formed by the laser are covered with the insulating resin layer 14. The insulating resin layer 14 is provided in a stripe pattern in the length direction (L direction) across the entire first sheet 10B. The insulating resin layer 14 is also provided on both sides of the valve-acting metal substrate 11 in the region 16 in which the porous portion 12 has been removed by a laser.

[0165] The method and material for forming the insulating resin layer 14 are the same as those described in the first embodiment, so a detailed explanation will be omitted.

[0166] In the fifth embodiment, (C) in the step of producing a laminated sheet, a laminated sheet is produced by laminating a first sheet and a second sheet, each having an insulating resin layer formed in the region where the porous portion has been removed by a laser.

[0167] The subsequent steps are the same as those of the first embodiment, the second embodiment, or the seventh embodiment described later. A solid electrolytic capacitor is obtained as a result.

[0168] According to the manufacturing method for solid electrolytic capacitors of the fifth embodiment of the present invention, the collapse of the porous portion can be suppressed very effectively while efficiently forming individual pieces.

[0169] [Solid electrolytic capacitor] A solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0170] The solid electrolytic capacitor according to the fifth embodiment of the present invention differs from the third and fourth embodiments in that, in the element stack, the first layer has a region from which the porous portion has been removed along the first and second sides facing each other in the width direction.

[0171] Figures 20A and 20B are schematic perspective views showing an example of a solid electrolytic capacitor according to the fifth embodiment of the present invention. The solid electrolytic capacitor 1C shown in Figures 20A and 20B comprises an element stack 100C, a first external electrode 141, and a second external electrode 142. In Figures 20A and 20B, a portion of the element stack 100C, the first external electrode 141, and the second external electrode 142 are shown with dashed lines.

[0172] In the element stack 100C, as in the first and third embodiments, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, and a second layer 120 made of metal foil 21 are stacked.

[0173] As shown in Figure 20A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100C.

[0174] On the other hand, as shown in Figure 20B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102 of the element stack 100C.

[0175] As shown in Figure 20B, along the first side surface S101 and the second side surface S102 that are opposite in the width direction, the first layer 110 has a region 16 in which the porous portion 12 of the valve-acting metal substrate 11 has been removed by a laser, and an insulating resin layer 14 is formed in the region 16 in which the porous portion 12 has been removed.

[0176] Therefore, according to the solid electrolytic capacitor of the fifth embodiment of the present invention, short circuits caused by the collapse of the porous portion can be suppressed very effectively.

[0177] (Sixth Embodiment) In the method for manufacturing a solid electrolytic capacitor according to the sixth embodiment of the present invention, (A) the step of preparing the first sheet is the same as in the fifth embodiment in that it includes a step of removing porous portions from the first and second sides of each element region using a laser, but the step of applying an insulating resin material to the region from which the porous portion has been removed by the laser is not performed. Even in this case, the amount of porous portion that collapses is reduced, so problems due to collapse are reduced.

[0178] In the sixth embodiment, (C) in the step of manufacturing a laminated sheet, a laminated sheet is manufactured by laminating a first sheet and a second sheet, in which an insulating resin material has not been applied to the region where the porous portion has been removed by a laser.

[0179] The subsequent steps are the same as those of the first embodiment, the second embodiment, or the seventh embodiment described later. A solid electrolytic capacitor is obtained as a result.

[0180] According to the manufacturing method for solid electrolytic capacitors as embodied in the sixth embodiment of the present invention, it is possible to efficiently separate the capacitor into individual pieces while effectively suppressing the collapse of the porous portion.

[0181] [Solid electrolytic capacitor] A solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0182] The solid electrolytic capacitor according to the sixth embodiment of the present invention is similar to the fifth embodiment in that, in the element stack, the first layer has a region where the porous portion has been removed along the first and second sides facing each other in the width direction, but an insulating resin material is not applied to the region where the porous portion has been removed.

[0183] Figures 21A and 21B are schematic perspective views showing an example of a solid electrolytic capacitor according to the sixth embodiment of the present invention. The solid electrolytic capacitor 1D shown in Figures 21A and 21B comprises an element stack 100D, a first external electrode 141, and a second external electrode 142. In Figures 21A and 21B, a portion of the element stack 100D, the first external electrode 141, and the second external electrode 142 are shown with dashed lines.

[0184] In the element laminate 100D, as in the first and third embodiments, as shown in Figure 7, a first layer 110 comprising a valve-acting metal substrate 11 having a porous portion 12 on its surface, a dielectric layer (not shown) formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer, is laminated with a second layer 120 made of metal foil 21.

[0185] As shown in Figure 21A, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element stack 100D.

[0186] On the other hand, as shown in Figure 21B, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102 of the element stack 100D.

[0187] As shown in Figure 21B, along the first side surface S101 and the second side surface S102, which are opposite in the width direction, the first layer 110 has a region 16 where the porous portion 12 of the valve-acting metal substrate 11 has been removed by a laser, but no insulating resin material is applied to the region 16 where the porous portion 12 has been removed. The region 16 where the porous portion 12 has been removed is covered by a fourth sealing portion 134.

[0188] According to the solid electrolytic capacitor of the sixth embodiment of the present invention, short circuits caused by the collapse of the porous portion can be effectively suppressed.

[0189] (Seventh Embodiment) [Method for Manufacturing Solid Electrolytic Capacitors] In the method for manufacturing solid electrolytic capacitors according to the seventh embodiment of the present invention, the step of manufacturing the laminated block body (D) described in the first embodiment is omitted.

[0190] Therefore, in the seventh embodiment, in step (E), multiple element stacks are manufactured by cutting the laminated sheet. More specifically, in the seventh embodiment, the element stacks are manufactured as follows.

[0191] First, the laminated sheet is cut along the first and second sides of each element region using a guillotine blade while applying ultrasonic vibrations, thereby forming multiple strip-shaped laminated sheets.

[0192] Figure 22 is a schematic perspective view showing an example of a laminated sheet after cutting. For example, the laminated sheet 30 shown in Figure 3B is cut along the first and second sides (cutting lines S111) of each element region with a guillotine blade while applying ultrasonic vibration, as shown in Figure 22. As a result, the laminated sheet 30 is divided into a plurality of strip-shaped laminated sheets 220.

[0193] Next, multiple strip-shaped laminated sheets are placed on a resin substrate made of a first resin having insulating properties.

[0194] Figure 23 is a schematic perspective view showing an example of the structure of a resin substrate. Figure 24A is a schematic perspective view showing an example of a structure in which strip-shaped laminated sheets are arranged on a resin substrate, and Figure 24B is a cross-sectional view taken along line A-A in Figure 24A.

[0195] As shown in Figures 23, 24A, and 24B, the laminated sheets 220, cut into strips, are placed on the resin substrate 510. More specifically, the multiple laminated sheets 220 are placed in the multiple grooves 516 formed in the resin substrate 510, for example, by pick and place. In this case, the laminated sheets 220 are placed in a state in which they can stand upright in the grooves 516. The state in which the laminated sheets 220 can stand upright means that the stacking direction of the first sheet and the second sheet of the laminated sheet 220 is substantially parallel to the depth direction of the groove 516.

[0196] Note that the arrangement method is not limited to pick and place. For example, the following method can also be used. Multiple laminated sheets 220 are placed on a stretchable sheet and stretched to match the shape of multiple grooves 516 of the resin substrate 510. In this way, the multiple laminated sheets 220 are arranged at predetermined intervals. While maintaining this state, the multiple laminated sheets 220 are stacked so that they are accommodated in the multiple grooves 516. In this way, the multiple laminated sheets 220 can be easily arranged in relation to the grooves 516.

[0197] The structure of the resin substrate 510 described above will now be explained in more detail. The resin substrate 510 is made of an insulating resin. As shown in Figure 23, the resin substrate 510 has a bottom surface 511, side surfaces 512, 513, 514, 515, a plurality of grooves 516, and a plurality of partitions 517. Side surfaces 512 and 514 are parallel, and side surfaces 513 and 515 are parallel. Side surfaces 512, 514 and side surfaces 513, 515 are perpendicular. The plurality of grooves 516 are formed by the bottom surface 511, side surfaces 512, 513, 514, 515, and the plurality of partitions 517.

[0198] In the example shown in Figure 23, the multiple grooves 516 are formed parallel to the side portions 512 and 514 and at predetermined intervals. In other words, the multiple grooves 516 are formed at predetermined intervals by the side portions 512, 513, 514, and 515, each having a predetermined thickness, and the multiple partition portions 517. This predetermined interval corresponds to the width of the partition portions 517. In this case, it is preferable that the multiple grooves 516 are formed at approximately equal intervals. This approximately equal arrangement includes configurations that are not unintentionally equal due to manufacturing tolerances, and does not need to be perfectly equal.

[0199] Multiple laminated sheets 220 are placed in each of the multiple grooves 516 formed in this manner. At this time, the bottom surfaces of the multiple laminated sheets 220 are positioned to abut against the bottom surfaces of the multiple grooves 516.

[0200] A more specific structure for arranging the laminated sheet 220 on the resin substrate 510 will be described using Figures 24A and 24B. Note that the line A-A in Figure 24A is perpendicular to the direction of the long side of the groove 516 formed in the resin substrate 510.

[0201] As shown in Figures 24A and 24B, the multiple laminated sheets 220 are arranged in the multiple grooves 516. As shown in Figure 24B, it is preferable that the laminated sheets 220 are arranged approximately in the center of the grooves 516 along a direction perpendicular to the line A-A in Figure 24A.

[0202] Next, based on the structure in which the laminated sheets are arranged in Figures 24A and 24B, a more preferable structure for the resin substrate 510 will be described.

[0203] As shown in Figure 24B, the width D1 of the multiple grooves 516 parallel to the A-A line of the resin substrate 510 is greater than the width 220D of the laminated sheet 220. In other words, it is preferable to allow some play so that the width D1 of the grooves 516 is greater than the width 220D of the laminated sheet 220. With such a configuration, it becomes possible to arrange the laminated sheet 220 more efficiently in the grooves 516 than if the width D1 of the grooves 516 and the width 220D of the laminated sheet 220 were approximately the same. In this case, by bringing the width D1 of the grooves 516 closer to the width 220D of the laminated sheet, it becomes possible to arrange the laminated sheet 220 with greater precision in the grooves 516.

[0204] Furthermore, the height (depth) H of the groove 516 in the resin substrate 510 can be determined arbitrarily. In this case, the height H of the groove 516 should be such that it prevents the laminated sheet 220 from tipping over when it is placed in the groove 516. Note that this height H may be the same as the height of the side portions 512, 513, 514, and 515, or it may be smaller than the height of the side portions 512, 513, 514, and 515.

[0205] Furthermore, adjacent grooves 516 are formed with a gap D2 between them by a partition 517. The width (gap D2) of this partition 517 should be determined according to the size of the solid electrolytic capacitor.

[0206] Next, the first and second sides of the strip-shaped laminated sheet are covered with a second insulating resin, and the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole are filled with the second resin, thereby sealing the strip-shaped laminated sheet.

[0207] Figure 25 is a schematic cross-sectional view showing an example of a sealed state of a strip-shaped laminated sheet. Note that, similar to Figure 24B, Figure 25 is a cross-sectional view taken along the line A-A in Figure 24A.

[0208] As shown in Figure 25, the strip-shaped laminated sheet 220 placed on the resin substrate 510 is sealed with insulating resin 520 so as to cover it. In this way, the top and sides of the laminated sheet 220 are sealed with insulating resin 520.

[0209] Then, the strip-shaped laminated sheet sealed with the first resin and the second resin is cut at the first and second ends of each element region, and also at the first and second sides of each element region, thereby obtaining an element laminate.

[0210] Figure 26A is a schematic perspective view showing an example of a strip-shaped laminated sheet sealed with insulating resin, and Figure 26B is a schematic perspective view showing an example of a laminated sheet separated into individual pieces.

[0211] As shown in Figure 26A, the strip-shaped laminated sheet 220 is sealed with an insulating resin 530 (resin substrate 510 and insulating resin 520).

[0212] The laminated sheet 220, sealed with insulating resin 530, is divided into individual pieces along cutting lines S121 and E121 using a dicing blade (see Figure 26B). This yields the element laminate 100 shown in Figure 11A. In this case, if cutting line E121 is parallel to line A-A in Figure 24A, cutting line S121 is defined between adjacent grooves 516 of the resin substrate 510, in other words, on the partition 517. More specifically, it is preferable that cutting line S121 is defined at approximately the center of the partition 517.

[0213] The laminated sheet, filled with insulating resin in this manner, is separated into individual pieces in a single process.

[0214] The subsequent steps are the same as in the first or second embodiment. A solid electrolytic capacitor is obtained as a result. In the method for manufacturing a solid electrolytic capacitor according to the seventh embodiment of the present invention, similar to the first embodiment, the porous portion can be efficiently separated into individual pieces while suppressing collapse.

[0215] The solid electrolytic capacitor obtained by the manufacturing method described above is also one of the present inventions.

[0216] (Other Embodiments) The method for manufacturing a solid electrolytic capacitor and the solid electrolytic capacitor of the present invention are not limited to the embodiments described above, and various applications and modifications can be made within the scope of the present invention with respect to the configuration, manufacturing conditions, etc., of the solid electrolytic capacitor.

[0217] For example, in the method for manufacturing a solid electrolytic capacitor of the present invention, both the step of coining the first and second sides of each element region and the step of removing the porous portion in the first and second sides of each element region using a laser may be performed. More specifically, for example, after coining the first and second sides of each element region, the coined porous portion may be removed using a laser. Alternatively, the first sheet may separately contain regions where the first and second sides have been coined and regions where the porous portion in the first and second sides has been removed using a laser.

[0218] Similarly, the solid electrolytic capacitor of the present invention may have a first layer along a first side and a second side, comprising a region where the porous portion is coined and a region where the porous portion is removed. More specifically, for example, the first layer may have a region along a first side and a second side where the porous portion is both coined and removed. Alternatively, the first layer may have a region along a first side where the porous portion is coined and a region along a second side where the porous portion is removed.

[0219] 1, 1A, 1B, 1C, 1D Solid electrolytic capacitor 10, 10A, 10B First sheet 11 Valve-acting metal substrate 12 Porous portion 13 Solid electrolyte layer 14 Insulating resin layer 15 Coined region 16 Region where the porous portion has been removed by laser 20 Second sheet 21 Metal foil 30 Laminated sheet 40, 40a, 40b Laminated block 50 Guillotine blade 100, 100A, 100B, 100C, 100D Element laminate 110 First layer 120 Second layer 131 First sealing portion 132 Second sealing portion 133 Third sealing portion 134 Fourth sealing portion 141 First external electrode 142 Second external electrode R11 First element region of the first sheet R12 R21 Second element region of the first sheet R22 Second element region of the second sheet E11 First end of the element region of the first sheet E12 Second end of the element region of the first sheet E21 First end of the element region of the second sheet E22 Second end of the element region of the second sheet E101 First end face of the element stack E102 Second end face of the element stack S11 First side of the element region of the first sheet S12 Second side of the element region of the first sheet S21 First side of the element region of the second sheet S22 Second side of the element region of the second sheet S101 First side surface of the element stack S102 Second side surface of the element stack M31 First main surface of the stacked sheet M32 Second main surface of the stacked sheet M101 First main surface of the element stack M102 Second main surface of the element stack H1 First through hole H2 Second through hole H3 Third through hole H4 Fourth through hole G Gap in the stacked block

Claims

1. A method for manufacturing a solid electrolytic capacitor comprising the following steps: (A) Step of preparing a first sheet; The first sheet comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer, and further, the first sheet has a plurality of element regions, each element region being demarcated by a first end and a second end opposite to each other in the length direction, and a first side and a second side opposite to each other in the width direction, and further, the first sheet has a first through hole formed so as to straddle the first end of each element region and having a width greater than or equal to the width of the element region, and one or more second through holes formed so as to straddle the second end of each element region and having a width less than the width of the element region, (B) Step of preparing a second sheet; The second sheet is made of metal foil, Furthermore, the second sheet has a plurality of element regions, each element region is demarcated by a first end and a second end facing each other in the length direction, and a first side and a second side facing each other in the width direction, and furthermore, the second sheet has one or more third through holes formed thereon that straddle the first end of each element region and have a width smaller than the width of the element region, and a fourth through hole formed thereon that straddles the second end of each element region and has a width greater than or equal to the width of the element region, (C) Step of manufacturing a laminated sheet; (C) Step in which the first sheet and the second sheet are laminated such that the first ends of each element region and the second ends of each element region face each other, and furthermore, in the laminated sheet, the first through hole and the third through hole, and the second through hole and the fourth through hole are in communication in the lamination direction, (D) Step of manufacturing a laminated block body as necessary; (D) In ​​step (D), a sealing material is filled into the first through hole and the third through hole, and the second through hole and the fourth through hole, respectively, from at least one of the first and second main surfaces of the laminated sheet that are opposite each other in the lamination direction; (E) A step of manufacturing a plurality of element laminates by cutting the laminated sheet or the laminated block;(E) In step (E), the laminated sheet or the laminated block is cut at the positions of the first and second ends of each element region, and is cut along the first and second sides of each element region with a guillotine blade while applying ultrasonic vibration; (F) A step of forming a first external electrode and a second external electrode on the element laminate.

2. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein (A) the step of preparing a first sheet comprises filling the porous portion with an insulating resin material in the first and second sides of each element region to form an insulating resin layer, and (C) the step of manufacturing a laminated sheet comprises laminating the first sheet and the second sheet on which the insulating resin layer is formed.

3. (A) The method for manufacturing a solid electrolytic capacitor according to claim 1 or 2, comprising the step of preparing a first sheet, wherein the first side and the second side of each element region are coined.

4. The method for manufacturing a solid electrolytic capacitor according to claim 3, wherein (A) the step of preparing a first sheet comprises the step of forming an insulating resin layer by applying an insulating resin material to a coined region, and (C) the step of manufacturing a laminated sheet comprises laminating the first sheet, on which the insulating resin layer is formed in the coined region, and the second sheet.

5. (C) The method for manufacturing a solid electrolytic capacitor according to claim 3, wherein in the step of manufacturing a laminated sheet, the first sheet and the second sheet, which do not have insulating resin material applied to the coined region, are laminated together.

6. (A) A method for manufacturing a solid electrolytic capacitor according to any one of claims 1 to 5, comprising the step of preparing a first sheet, wherein the porous portion is removed by laser from the first side and the second side of each element region.

7. The method for manufacturing a solid electrolytic capacitor according to claim 6, wherein (A) the step of preparing a first sheet comprises the step of forming an insulating resin layer by applying an insulating resin material to the region from which the porous portion has been removed by a laser, and (C) the step of manufacturing a laminated sheet comprises laminating the first sheet, from which the insulating resin layer has been formed in the region from which the porous portion has been removed by a laser, with the second sheet.

8. (C) The method for manufacturing a solid electrolytic capacitor according to claim 6, wherein in the step of manufacturing a laminated sheet, the first sheet and the second sheet are laminated, wherein the region from which the porous portion has been removed by a laser is not coated with insulating resin material.

9. A solid electrolytic capacitor comprising an element stack, a first external electrode, and a second external electrode, wherein the element stack comprises a first layer and a second layer, the first layer comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer, the second layer comprises a metal foil, further comprising the first end face and the second end face of the element stack, with the metal foil and the first sealing portion exposed at the first end face and the valve-acting metal substrate and the second sealing portion exposed at the second end face, the first external electrode provided at the first end face of the element stack and connected to the metal foil, and the second external electrode provided at the second end face of the element stack and connected to the valve-acting metal substrate. In the aforementioned element stack, the first layer has a region in which the porous portion is coined along a first side surface and a second side surface that are opposite to each other in the width direction, thereby forming a solid electrolytic capacitor.

10. The solid electrolytic capacitor according to claim 9, wherein the first layer comprises an insulating resin layer formed in the coined region.

11. The solid electrolytic capacitor according to claim 9, wherein the first layer is not coated with an insulating resin material in the coined region.

12. A solid electrolytic capacitor comprising an element stack, a first external electrode, and a second external electrode, wherein the element stack comprises a first layer and a second layer, the first layer comprises a valve-acting metal substrate having a porous portion on its surface, a dielectric layer formed on the surface of the porous portion, and a solid electrolyte layer provided on the dielectric layer, the second layer is made of metal foil, further comprising the first end face and the second end face of the element stack, the metal foil and the first sealing portion being exposed on the first end face and the valve-acting metal substrate and the second sealing portion being exposed on the second end face, the first external electrode being provided on the first end face of the element stack and connected to the metal foil, and the second external electrode being provided on the second end face of the element stack and connected to the valve-acting metal substrate. In the aforementioned element stack, the first layer has a region where the porous portion has been removed along a first side surface and a second side surface that are opposite to each other in the width direction, thereby forming a solid electrolytic capacitor.

13. The solid electrolytic capacitor according to claim 12, wherein the first layer comprises an insulating resin layer formed in the region from which the porous portion has been removed.

14. The solid electrolytic capacitor according to claim 12, wherein the first layer is not coated with an insulating resin material in the region from which the porous portion has been removed.

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