Solid electrolytic capacitor and capacitor array

Abstract

A solid electrolytic capacitor (110) is provided with: an anode plate (10) having a core (11), a porous layer (12) provided on at least one main surface of the core (11), and a dielectric layer (13) provided on the surface of the porous layer (12); and a cathode layer (20) provided on the surface of the dielectric layer (13). The cathode layer (20) includes a solid electrolyte layer (21) provided on the surface of the dielectric layer (13). The solid electrolyte layer (21) includes a conductive polymer layer in which a conductive polymer and an insulating material are mixed inside the pores of the dielectric layer (13). The insulating material contains an OH group, a COOH group, a CO group, or an NH2 group in the molecule, has hygroscopicity, and does not have a doping function with respect to the conductive polymer.

Description

Technical Field

[0001] The present invention relates to solid electrolytic capacitors and capacitor arrays. Background Art

[0002] A solid electrolytic capacitor includes, for example, an anode plate having a dielectric layer formed of a valve-acting metal such as aluminum on the surface of a porous layer provided on at least one main surface of a core, and a cathode layer including a solid electrolyte layer provided on the surface of the dielectric layer.

[0003] Patent Document 1 discloses a solid electrolytic capacitor in which a moisture absorbent is disposed near a solid electrolyte provided on a dielectric. Patent Document 1 describes silica gel, calcium oxide, anhydrous calcium chloride, anhydrous sodium sulfate, and anhydrous copper sulfate as examples of the moisture absorbent.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 3-276620 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] According to Patent Document 1, the moisture absorbent disposed near the solid electrolyte effectively absorbs moisture that penetrates the exterior, and thus the characteristics are less degraded under high temperature and high humidity.

[0009] However, in the case of fully covering the moisture ingress path to the solid electrolytic capacitor, it is difficult to arrange the hygroscopic layer around the entire periphery of the solid electrolytic capacitor in the method of arranging a layer of a moisture absorbent (hereinafter referred to as a hygroscopic layer) on the outside of the solid electrolytic capacitor as shown in the figure of Patent Document 1. In particular, in the case of cutting a capacitor sheet into individual solid electrolytic capacitors in order to manufacture a capacitor array having a plurality of solid electrolytic capacitors inside a sealing layer, it is difficult to arrange the hygroscopic layer around the entire periphery of each solid electrolytic capacitor.

[0010] An object of the present invention is to provide a solid electrolytic capacitor capable of suppressing capacitance fluctuations due to moisture absorption. Another object of the present invention is to provide a capacitor array having two or more of the above solid electrolytic capacitors inside a sealing layer.

[0011] Solutions for solving problems

[0012] The solid electrolytic capacitor of the present invention comprises: an anode plate having a core, a porous layer provided on at least one main surface of the core, and a dielectric layer provided on the surface of the porous layer; and a cathode layer provided on the surface of the dielectric layer. The cathode layer comprises a solid electrolyte layer provided on the surface of the dielectric layer. The solid electrolyte layer comprises a conductive polymer layer in which a conductive polymer and an insulating material are mixed inside the pores of the dielectric layer. The insulating material is a material that contains an OH group, a COOH group, a CO group or an NH2 group in the molecule, has hygroscopicity, and has no doping function relative to the conductive polymer.

[0013] The capacitor array of the present invention includes: the solid electrolytic capacitor of the present invention; a sealing layer, which is arranged in a manner covering the above-mentioned solid electrolytic capacitor; a first external electrode and a second external electrode, which are arranged on the outside of the above-mentioned sealing layer; a via conductor, which is arranged inside the above-mentioned sealing layer; and a through-hole conductor, which is arranged in a manner penetrating the above-mentioned sealing layer in the thickness direction. There are more than two of the above-mentioned solid electrolytic capacitors inside the above-mentioned sealing layer. The above-mentioned through-hole conductor is electrically connected to the end face of the anode plate of the above-mentioned solid electrolytic capacitor at its side wall. The above-mentioned first external electrode is electrically connected to the anode plate of the above-mentioned solid electrolytic capacitor via the above-mentioned through-hole conductor. The above-mentioned second external electrode is electrically connected to the cathode layer of the above-mentioned solid electrolytic capacitor via the above-mentioned via conductor.

[0014] Effects of the Invention

[0015] According to the present invention, a solid electrolytic capacitor capable of suppressing capacitance fluctuations due to moisture absorption can be provided. According to the present invention, a capacitor array including two or more solid electrolytic capacitors in a sealing layer can also be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. 1 is a cross-sectional view schematically showing an example of a capacitor array according to the present invention.

[0017] Figure 2 It will be Figure 1 A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged.

[0018] Figure 3 It is schematically indicated Figure 1 A three-dimensional view of the internal structure of the capacitor array shown.

[0019] Figure 4 This is a perspective view schematically showing an example of a process of preparing an anode plate.

[0020] Figure 5 It will be Figure 4The cross-sectional view is an enlarged view of a portion of the anode plate surrounded by a dotted line.

[0021] Figure 6 This is a cross-sectional view schematically showing an example of the process of forming the first conductive polymer layer.

[0022] Figure 7 This is a cross-sectional view schematically showing an example of the process of forming the second conductive polymer layer.

[0023] Figure 8 This is a perspective view schematically showing an example of a step of forming the third conductive polymer layer.

[0024] Fig. 9 It will be Figure 8 The cross-sectional view is an enlarged view of a portion of the anode plate surrounded by a dotted line.

[0025] Fig.10 It is a perspective view schematically showing an example of the process of forming the first conductive layer.

[0026] Fig.11 It is a perspective view schematically showing an example of the process of forming the second conductive layer.

[0027] Fig.12 This is a perspective view schematically showing an example of a process of cutting an anode plate having a cathode layer formed thereon.

[0028] Fig.13 It is a perspective view schematically showing an example of a process of forming the second through hole.

[0029] Fig.14 It is a perspective view schematically showing an example of a step of forming a sealing layer.

[0030] Fig.15 It is a perspective view schematically showing an example of a process of forming a first through hole.

[0031] Fig.16 It is a perspective view schematically showing an example of a process of forming a through-hole conductor.

[0032] Fig.17 It is a perspective view schematically showing an example of a process of forming a via conductor.

[0033] Fig.18 FIG. 1 is a cross-sectional view schematically showing another example of the capacitor array of the present invention.

[0034] Fig.19 It will be Fig.18 A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged.

[0035] Fig. 20 1 is a cross-sectional view schematically showing an example of a capacitor array according to Comparative Example 1.

[0036] Fig.21 It will be Fig. 20 A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged.

[0037] Fig. 22 Graph showing the relationship between humidity and capacity variation rate of the solid electrolytic capacitors of Example 2 and Comparative Example 1. DETAILED DESCRIPTION

[0038] Hereinafter, the solid electrolytic capacitor and the capacitor array of the present invention will be described.

[0039] However, the present invention is not limited to the following configurations, and can be applied with appropriate changes within the scope of the gist of the present invention. In addition, a configuration in which two or more of the preferred configurations of the present invention described below are combined is also the present invention.

[0040] In the examples shown below, the capacitor array of the present invention is described with reference to the accompanying drawings. The solid electrolytic capacitor included in such a capacitor array is also one of the present invention. The solid electrolytic capacitor of the present invention may exist in two or more or only one inside the sealing layer.

[0041] The drawings shown below are schematic diagrams, and their dimensions, aspect ratios, and other aspects may differ from those of actual products.

[0042] Figure 1 FIG. 1 is a cross-sectional view schematically showing an example of a capacitor array according to the present invention. Figure 2 It will be Figure 1 A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged. Figure 3 It is schematically indicated Figure 1 A three-dimensional diagram of the internal structure of the capacitor array is shown. Figure 3 In the embodiment, the first external electrode and the second external electrode are omitted. Figure 1 yes Figure 3 A cross-sectional view of the capacitor array along line AA is shown.

[0043] Figure 1 The capacitor array 100 shown includes a plurality of solid electrolytic capacitors 110 and a sealing layer 120 provided in a manner covering the solid electrolytic capacitors.

[0044] The solid electrolytic capacitor 110 includes an anode plate 10 and a cathode layer 20 .

[0045] The anode plate 10 includes: a core 11; a porous layer 12 provided on at least one main surface of the core 11; and a dielectric layer 13 (see Figure 2 ), which is provided on the surface of the porous layer 12. Figure 1 In the figure, the porous layer 12 of the anode plate 10 is shown separately, but in reality, Figure 2 As shown, a part of the solid electrolyte layer 21 constituting the cathode layer 20 is provided inside the pores (recesses) of the dielectric layer 13. The same is true in the subsequent cross-sectional views.

[0046] The anode plate 10 is formed of a valve metal that exhibits a so-called valve action. Examples of the valve metal include metal monomers such as aluminum, tantalum, niobium, titanium, and zirconium, or alloys containing at least one of these metals. Among them, aluminum or an aluminum alloy is preferred.

[0047] The shape of the anode plate 10 is preferably a flat plate, more preferably a foil. In the anode plate 10, the porous layer 12 can be provided on at least one main surface of the core 11, or the porous layer 12 can be provided on both main surfaces of the core 11. Preferably, the porous layer 12 is an etching layer formed on the surface of the anode plate 10.

[0048] The thickness of the anode plate 10 before etching is preferably 60 μm or more and 200 μm or less. The thickness of the core 11 that is not etched after etching is preferably 15 μm or more and 70 μm or less. The thickness of the porous layer 12 is designed according to the required withstand voltage and electrostatic capacitance, but preferably, the total thickness of the porous layers 12 on both sides of the core 11 is 10 μm or more and 180 μm or less.

[0049] The pore size of the porous layer 12 is preferably 10 nm or more and 600 nm or less. The pore size of the porous layer 12 refers to the median pore size D50 measured by a mercury porosimeter. The pore size of the porous layer 12 can be controlled by adjusting various conditions during etching, for example.

[0050] The dielectric layer 13 is porous reflecting the surface state of the porous layer 12 and has a fine concavoconvex surface shape (see Figure 2 ). Preferably, the dielectric layer 13 is composed of an oxide film of the valve action metal. For example, when aluminum foil is used as the anode plate 10, the dielectric layer 13 composed of an oxide film can be formed by performing an anodic oxidation treatment (also called chemical conversion treatment) on the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like.

[0051] The thickness of the dielectric layer 13 is designed according to the required withstand voltage and electrostatic capacitance, but is preferably not less than 10 nm and not more than 100 nm.

[0052] The cathode layer 20 is provided on the surface of the dielectric layer 13. When the first insulating layer 30 described later is provided on the anode plate 10, it is preferred that the cathode layer 20 is provided on the surface of the dielectric layer 13 in the region (hereinafter also referred to as the element region) surrounded by the first insulating layer 30. In addition, the cathode layer 20 may be provided in a manner extending to the surface of the first insulating layer 30.

[0053] The cathode layer 20 includes a solid electrolyte layer 21 provided on the surface of the dielectric layer 13. Preferably, the cathode layer 20 further includes a conductor layer 22 provided on the surface of the solid electrolyte layer 21. Figure 1 In the figure, the solid electrolyte layer 21 and the porous layer 12 of the anode plate 10 are shown to be completely separated, but in reality, Figure 2 As shown, a part of the solid electrolyte layer 21 is provided inside the pores (concave portions) of the dielectric layer 13 .

[0054] The solid electrolyte layer 21 contains a conductive polymer.

[0055] As the material constituting the solid electrolyte layer 21, for example, conductive polymers such as polypyrrole, polythiophene, and polyaniline can be cited. Among them, polythiophenes are preferred, and poly (3,4-ethylenedioxythiophene) called PEDOT is particularly preferred. In addition, the conductive polymers may also contain dopants such as polystyrene sulfonic acid (PSS).

[0056] The thickness of the solid electrolyte layer 21 from the surface of the anode plate 10 is preferably 2 μm or more and 20 μm or less.

[0057] The thickness of the solid electrolyte layer 21 can be adjusted by Figure 2 The thickness of each layer constituting the solid electrolyte layer 21 described later can be measured by using an electron micrograph of a cross section in the thickness direction of the anode plate 10 as shown.

[0058] The solid electrolyte layer 21 includes a conductive polymer layer in which a conductive polymer and an insulating material are mixed inside the pores of the dielectric layer 13. The insulating material is a material that contains an OH group, a COOH group, a CO group, or an NH2 group in the molecule, has hygroscopicity, and has no doping function with respect to the conductive polymer.

[0059] In solid electrolytic capacitor 110, the portion of solid electrolyte layer 21 provided inside the pores of dielectric layer 13 contains a hygroscopic insulating material. Therefore, the expansion of the insulating material can suppress the change in capacitance caused by moisture absorption of the conductive polymer.

[0060] For example, in the case of manufacturing a solid electrolytic capacitor 110 by cutting a capacitor sheet, and in particular, in the case of cutting a capacitor sheet and dividing it into individual solid electrolytic capacitors 110 in order to manufacture a capacitor array 100 in which a plurality of solid electrolytic capacitors 110 exist inside a sealing layer 120, unlike Patent Document 1, it is not necessary to configure a hygroscopic layer around the entire periphery of the cut solid electrolytic capacitor 110, so that the change in capacity caused by moisture absorption can be easily suppressed.

[0061] In addition, in the capacitor array 100, when the via conductor 50, the through-hole conductor 61 or the through-hole conductor 62 described later are provided, in the case of a method of configuring a hygroscopic layer around the entire periphery of the solid electrolytic capacitor 110, the through hole for forming the via conductor 50 etc. must be formed in the hygroscopic layer, so it is difficult to obtain a sufficient moisture-proof effect. From this point of view, it is also preferable that the insulating material having hygroscopicity is included in the solid electrolyte layer 21. In addition, this is true not only when there are multiple solid electrolytic capacitors 110 inside the sealing layer 120, but also when there is one solid electrolytic capacitor 110 inside the sealing layer 120.

[0062] As described above, the effect achieved by including the hygroscopic insulating material in the solid electrolyte layer 21 is an effect of the capacitor array 100 , and can also be said to be an effect of the solid electrolytic capacitor 110 .

[0063] As the insulating material included in the conductive polymer layer, for example, phenolic materials can be cited. The insulating material included in the conductive polymer layer may also have a function of supplying hydrogen radicals (H·) to free radicals (R·) generated from heat in the molecular chain of the conductive polymer and peroxy radicals (ROO·) generated by the reaction of the free radicals (R·) and oxygen to stabilize them.

[0064] exist Figure 2 In the example shown, the solid electrolyte layer 21 includes a first conductive polymer layer 21A, a second conductive polymer layer 21B, and a third conductive polymer layer 21C. In this example, the first conductive polymer layer 21A and the second conductive polymer layer 21B are provided inside the pores of the dielectric layer 13, and the second conductive polymer layer 21B includes an insulating material. However, only a conductive polymer layer including an insulating material may be provided inside the pores of the dielectric layer 13.

[0065] In addition, it is preferable that the insulating material included in the conductive polymer layer does not have a doping function with respect to the conductive polymer included in the solid electrolyte layer 21. For example, when the solid electrolyte layer 21 includes the first conductive polymer layer 21A containing the first conductive polymer, the second conductive polymer layer 21B containing the second conductive polymer, and the third conductive polymer layer 21C containing the third conductive polymer, it is preferable that the insulating material does not have a doping function with respect to the first conductive polymer, the second conductive polymer, and the third conductive polymer.

[0066] The first conductive polymer layer 21A is provided inside the pores (concave portions) of the dielectric layer 13. The first conductive polymer layer 21A may cover the entire pores of the dielectric layer 13 or may cover a part of the pores of the dielectric layer 13.

[0067] The first conductive polymer layer 21A is a layer containing a first conductive polymer. The first conductive polymer may be one type or two or more types. The first conductive polymer layer 21A may be one layer or two or more layers.

[0068] The first conductive polymer is, for example, a conductive polymer represented by poly(3,4-ethylenedioxythiophene), and is a material soluble in a solvent.

[0069] The first conductive polymer may contain a dopant as necessary.

[0070] The first conductive polymer layer 21A is formed, for example, by applying a liquid containing the first conductive polymer to the surface of the anode plate 10 and drying it. The liquid containing the first conductive polymer is preferably a liquid obtained by dissolving the first conductive polymer. Specifically, the first conductive polymer layer 21A can be formed in a predetermined area by applying the above-mentioned liquid to the surface of the anode plate 10 by a dipping method, sponge transfer, screen printing, dispenser coating, inkjet printing, or the like.

[0071] The second conductive polymer layer 21B is provided inside the pores (recesses) of the dielectric layer 13, and covers the first conductive polymer layer 21A. The second conductive polymer layer 21B may cover the entire first conductive polymer layer 21A, or may cover a part of the first conductive polymer layer 21A. The second conductive polymer layer 21B may also fill the pores (recesses) of the dielectric layer 13.

[0072] The second conductive polymer layer 21B is a layer in which the second conductive polymer and the insulating material are mixed. The second conductive polymer can be only one type or two or more types. Similarly, the insulating material can be only one type or two or more types. The second conductive polymer layer 21B can be one layer or two or more layers.

[0073] The second conductive polymer is preferably a conductive polymer different from the first conductive polymer. The second conductive polymer is, for example, a conductive polymer represented by poly(3,4-ethylenedioxythiophene), which has a larger particle size than the first conductive polymer, is insoluble in solvents, but has high heat resistance.

[0074] The second conductive polymer may contain a dopant as necessary.

[0075] It is preferable that the insulating material is not distributed unevenly inside the second conductive polymer layer 21B, and it is more preferable that the insulating material is uniformly dispersed inside the second conductive polymer layer 21B.

[0076] The thickness of second conductive polymer layer 21B may be the same as the thickness of first conductive polymer layer 21A, may be larger than the thickness of first conductive polymer layer 21A, or may be smaller than the thickness of first conductive polymer layer 21A.

[0077] The second conductive polymer layer 21B is formed, for example, by simultaneously applying a liquid containing the second conductive polymer and a liquid containing an insulating material to the surface of the anode plate 10 formed with the first conductive polymer layer 21A and drying the liquid. The liquid containing the second conductive polymer is preferably a liquid in which the second conductive polymer is dispersed, and the liquid containing the insulating material is preferably a liquid in which the insulating material is dissolved. Specifically, the second conductive polymer layer 21B can be formed in a predetermined area by simultaneously applying the above-mentioned liquids to the surface of the anode plate 10 formed with the first conductive polymer layer 21A by a dipping method, sponge transfer, screen printing, dispenser coating, inkjet printing, or the like.

[0078] Third conductive polymer layer 21C is provided on the surface of anode plate 10 and covers at least second conductive polymer layer 21B. Third conductive polymer layer 21C may cover not only second conductive polymer layer 21B but also first conductive polymer layer 21A.

[0079] The third conductive polymer layer 21C is a layer containing a third conductive polymer. Preferably, the third conductive polymer layer 21C further contains a binder. The third conductive polymer layer 21C may be a single layer or two or more layers.

[0080] The third conductive polymer may be the same conductive polymer as the first conductive polymer or the same conductive polymer as the second conductive polymer. The third conductive polymer may be one type or two or more types. The third conductive polymer may also contain a dopant as required.

[0081] Preferably, the thickness of third conductive polymer layer 21C is greater than the thickness of first conductive polymer layer 21A, and preferably, the thickness of third conductive polymer layer 21C is greater than the thickness of second conductive polymer layer 21B.

[0082] The third conductive polymer layer 21C is formed, for example, by applying a liquid containing the third conductive polymer to the surface of the anode plate 10 formed with the first conductive polymer layer 21A and the second conductive polymer layer 21B and drying it. Specifically, the third conductive polymer layer 21C can be formed in a predetermined area by applying the above-mentioned liquid to the surface of the anode plate 10 formed with the first conductive polymer layer 21A and the second conductive polymer layer 21B by a dipping method, sponge transfer, screen printing, dispenser coating, inkjet printing, etc.

[0083] Alternatively, the third conductive polymer layer 21C may be formed by forming a polymer film of the third conductive polymer on the surface of the anode plate 10 on which the first conductive polymer layer 21A and the second conductive polymer layer 21B are formed, using a liquid containing a monomer such as 3,4-ethylenedioxythiophene. In this case, the third conductive polymer layer 21C may be formed in a predetermined area by applying the above-mentioned liquid to the surface of the anode plate 10 on which the first conductive polymer layer 21A and the second conductive polymer layer 21B are formed, such as by dipping, sponge transfer, screen printing, dispenser coating, inkjet printing, or the like.

[0084] In order to suppress the risk of short circuit due to direct contact between the core 11 of the anode plate 10 and the conductor layer 22, it is preferred that the third conductive polymer layer 21C is formed using a liquid having a higher viscosity than the liquid used to form the first conductive polymer layer 21A and the second conductive polymer layer 21B so that the core 11 of the anode plate 10 is not exposed to the surface.

[0085] The conductor layer 22 includes at least one of a conductive resin layer and a metal layer. The conductor layer 22 may be only a conductive resin layer or only a metal layer. The conductor layer 22 may cover the entire solid electrolyte layer 21 or only a part of the solid electrolyte layer 21.

[0086] Examples of the conductive resin layer include a conductive adhesive layer containing at least one conductive filler selected from the group consisting of a silver filler, a copper filler, a nickel filler, and a carbon filler.

[0087] As the metal layer, for example, metal plating, metal foil, etc. can be cited. Preferably, the metal layer is formed of at least one metal selected from the group consisting of nickel, copper, silver, and alloys containing these metals as main components. In addition, the "main component" refers to the element component with the largest weight ratio.

[0088] The conductor layer 22 includes, for example, a first conductor layer 22A provided on the surface of the solid electrolyte layer 21 and a second conductor layer 22B provided on the surface of the first conductor layer 22A. As described above, the conductor layer 22 preferably includes a plurality of conductor layers.

[0089] The first conductor layer 22A is, for example, a conductive resin layer containing a conductive filler. The conductive filler is preferably at least one selected from the group consisting of a silver filler, a copper filler, a nickel filler, and a carbon filler.

[0090] The second conductor layer 22B is, for example, a conductive resin layer containing a metal filler. The metal filler is preferably at least one selected from the group consisting of a silver filler, a copper filler, and a nickel filler.

[0091] As an example, the conductor layer 22 includes a carbon layer as the first conductor layer 22A and a copper layer as the second conductor layer 22B.

[0092] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer 21 to the copper layer. The carbon layer can be formed in a predetermined area by applying the carbon slurry to the solid electrolyte layer 21 by a dipping method, sponge transfer, screen printing, dispenser coating, inkjet printing, etc. In addition, it is preferred that the carbon layer is laminated with the copper layer of the next process in a sticky state before drying. The thickness of the carbon layer is preferably greater than 2 μm and less than 20 μm.

[0093] The copper layer can be formed by printing a copper paste on the carbon layer by dipping, sponge transfer, screen printing, spray coating, dispenser coating, inkjet printing, etc. The thickness of the copper layer is preferably 2 μm or more and 20 μm or less.

[0094] Preferably, if Figure 1 and Figure 3 As shown, a first insulating layer 30 is provided in a region of the surface of the porous layer 12 where the cathode layer 20 is not formed. The first insulating layer 30 is provided so as to surround the cathode layer 20 when viewed in the thickness direction. The first insulating layer 30 partitions the element region of the solid electrolytic capacitor 110 .

[0095] All of the plurality of solid electrolytic capacitors 110 may be surrounded by the first insulating layer 30, or some solid electrolytic capacitors 110 may not be surrounded by the first insulating layer 30. Among the solid electrolytic capacitors 110 surrounded by the first insulating layer 30, the entire solid electrolytic capacitor 110 may be surrounded by the first insulating layer 30, or only part of the solid electrolytic capacitor 110 may be surrounded by the first insulating layer 30.

[0096] Furthermore, the first insulating layer 31 may be provided in a region of the surface of the porous layer 12 where the cathode layer 20 is not formed. The first insulating layer 31 is provided inside the cathode layer 20 when viewed in the thickness direction. In other words, the first insulating layer 31 is provided in the element region of the solid electrolytic capacitor 110. Preferably, the first insulating layer 31 is provided separately from the first insulating layer 30.

[0097] It is sufficient that at least one first insulating layer 31 is provided in at least one element region among the plurality of element regions. Figure 3 In the example shown, two first insulating layers 31 are provided in each element region.

[0098] Both the first insulating layers 30 and 31 may be provided on the surface of the porous layer 12 , or only one of them may be provided.

[0099] The first insulating layers 30 and 31 may be provided on the surface of the dielectric layer 13 on the porous layer 12. Preferably, the first insulating layers 30 and 31 are provided so as to fill the pores (concave portions) of the porous layer 12 or the dielectric layer 13.

[0100] The first insulating layers 30 and 31 contain an insulating material.

[0101] Preferably, the first insulating layers 30 and 31 are formed of resin. As the resin constituting the first insulating layers 30 and 31, for example, insulating resins such as polyphenylsulfone resin, polyethersulfone resin, cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), polyimide resin, polyamide-imide resin, epoxy resin, and derivatives or precursors thereof can be cited. The first insulating layers 30 and 31 may be composed of the same resin or different resins.

[0102] If first insulating layers 30 and 31 contain an inorganic filler, there is a possibility that an effective portion of solid electrolytic capacitor 110 is adversely affected. Therefore, first insulating layers 30 and 31 are preferably formed of a single type of resin.

[0103] The first insulating layers 30 and 31 can be formed, for example, by applying a masking material such as a composition containing an insulating resin onto the porous layer 12 by a method such as sponge transfer, screen printing, dispenser coating, or inkjet printing.

[0104] The thickness of the first insulating layers 30 and 31 from the surface of the anode plate 10 is preferably 20 μm or less. The thickness of the first insulating layers 30 and 31 from the surface of the anode plate 10 may be 0 μm, but is preferably 2 μm or more. The thicknesses of the first insulating layers 30 and 31 may be the same or different.

[0105] The thickness of the first insulating layers 30 and 31 can be measured using an electron microscope photograph of a cross section of the anode plate 10 in the thickness direction.

[0106] The planar shape of the first insulating layer 31 observed from the thickness direction is not particularly limited, and may be, for example, a polygon such as a quadrilateral, a circle, an ellipse, etc. When two or more first insulating layers 31 are provided in the element region, the size and planar shape of the first insulating layer 31 observed from the thickness direction may be the same, or may be partially or completely different.

[0107] The position where the first insulating layer 31 is provided in the device region is not particularly limited. When two or more first insulating layers 31 are provided in the device region, the positions where the first insulating layers 31 are provided may be the same or partially or completely different.

[0108] Although not shown, part of the first conductive polymer layer 21A and / or part of the second conductive polymer layer 21B may be exposed on the surface of the anode plate 10. In this case, it is preferred that the area of ​​the region where the first conductive polymer layer 21A and the second conductive polymer layer 21B are not present on the surface of the anode plate 10 is larger than the area of ​​the region where the first conductive polymer layer 21A and the second conductive polymer layer 21B are present on the surface of the anode plate 10. In addition, only a portion of the first conductive polymer layer 21A and the second conductive polymer layer 21B may be exposed to the surface of the anode plate 10, or only a portion of the second conductive polymer layer 21B may be exposed to the surface of the anode plate 10, or both a portion of the first conductive polymer layer 21A and a portion of the second conductive polymer layer 21B may be exposed to the surface of the anode plate 10.

[0109] Preferably, the portion of the first conductive polymer layer 21A and / or the second conductive polymer layer 21B exposed on the surface of the anode plate 10 is in contact with the first insulating layer 30. Particularly preferably, a portion of the first conductive polymer layer 21A and / or a portion of the second conductive polymer layer 21B is exposed along the inner edge of the first insulating layer 30. In this case, the portion of the first conductive polymer layer 21A and / or the portion of the second conductive polymer layer 21B may be exposed along the entire inner edge of the first insulating layer 30 or may be exposed along a portion of the inner edge of the first insulating layer 30.

[0110] Alternatively, part of the third conductive polymer layer 21C may enter the pores of the dielectric layer 13. When the third conductive polymer layer 21C covers the pores of the dielectric layer 13 and enters the pores of the dielectric layer 13, the occurrence of delamination between the porous layer 12 and the solid electrolyte layer 21 is easily suppressed due to the anchoring effect of the third conductive polymer layer 21C.

[0111] The depth to which the third conductive polymer layer 21C penetrates is not particularly limited. Figure 2 In the case of the cross section of the anode plate 10 in the thickness direction as shown, part of the third conductive polymer layer 21C only needs to enter the pores of the dielectric layer 13 .

[0112] In the case where a portion of the third conductive polymer layer 21C enters the pores of the dielectric layer 13, the cathode layer 20 may include the conductor layer 22, and the conductor layer 22 may include a conductive resin layer containing a metal filler. For example, in the case where the second conductor layer 22B is a conductive resin layer containing a metal filler, the difference in thermal properties such as the linear expansion coefficient between the solid electrolyte layer 21 and the conductor layer 22 is large, so delamination is likely to occur between the solid electrolyte layer 21 and the conductor layer 22. Even in such a case, by partially entering the pores of the dielectric layer 13, the occurrence of delamination between the solid electrolyte layer 21 and the conductor layer 22 can be suppressed.

[0113] Preferably, sealing layer 120 is provided so as to cover the entire outer periphery of solid electrolytic capacitor 110 , that is, so as to cover top, bottom, left, and right of solid electrolytic capacitor 110 .

[0114] The sealing layer 120 contains an insulating material.

[0115] The sealing layer 120 is preferably formed of a resin. Examples of the resin constituting the sealing layer 120 include epoxy resin and phenol resin. The sealing layer 120 may be formed of the same resin as the resin of the first insulating layer 30 or 31 .

[0116] Preferably, the sealing layer 120 further includes a filler. Examples of the filler included in the sealing layer 120 include inorganic fillers such as silica particles, alumina particles, and metal particles.

[0117] The sealing layer 120 may be composed of only one layer or may be composed of two or more layers. When the sealing layer 120 is composed of two or more layers, the materials constituting the respective layers may be the same or different.

[0118] A layer such as a stress relaxation layer or a moisture-proof film may be provided between the sealing layer 120 and the cathode layer 20 , between the sealing layer 120 and the first insulating layer 30 , or between the sealing layer 120 and the first insulating layer 31 .

[0119] Preferably, the stress relaxation layer is composed of an insulating resin. As the insulating resin constituting the stress relaxation layer, for example, epoxy resin, phenolic resin, silicone resin, etc. can be cited. It is further preferred that the stress relaxation layer contains a filler. As the filler contained in the stress relaxation layer, for example, inorganic fillers such as silica particles, alumina particles, and metal particles can be cited. Preferably, the insulating resin constituting the stress relaxation layer is different from the resin constituting the sealing layer 120.

[0120] The sealing layer 120 is required to have properties such as close adhesion to the external electrode as an outer casing, so it is difficult to generally match the linear expansion coefficient of the sealing layer 120 with the linear expansion coefficient of the solid electrolytic capacitor 110 and select a resin with an arbitrary elastic modulus. In contrast, by providing a stress relaxation layer, the thermal stress design can be adjusted without losing the functions of the solid electrolytic capacitor 110 and the sealing layer 120.

[0121] Preferably, the moisture permeability of the stress relaxation layer is lower than the moisture permeability of the sealing layer 120. In this case, in addition to the adjustment of the stress, it is also possible to reduce the penetration of moisture into the solid electrolytic capacitor 110. The moisture permeability of the stress relaxation layer can be adjusted by the type of insulating resin constituting the stress relaxation layer, the amount of filler contained in the stress relaxation layer, and the like.

[0122] It can also be, Figure 1 As shown in FIG. 1 , the capacitor array 100 further includes a first external electrode 41 and a second external electrode 42 disposed outside the sealing layer 120 . Figure 1 In the illustrated example, the first external electrode 41 and the second external electrode 42 are provided on both principal surface sides of the sealing layer 120 , but may be provided on only one principal surface side.

[0123] The first external electrode 41 is electrically connected to the anode plate 10 of the solid electrolytic capacitor 110. The second external electrode 42 is electrically connected to the cathode layer 20 of the solid electrolytic capacitor 110. The first external electrode 41 and the second external electrode 42 can function as connection terminals of the solid electrolytic capacitor 110.

[0124] As materials constituting the first external electrode 41 and the second external electrode 42, for example, low-resistance metals such as silver, gold, and copper can be cited. The constituent material of the first external electrode 41 may be the same as or different from the material constituting the second external electrode 42. The first external electrode 41 and the second external electrode 42 are formed by, for example, plating treatment or the like.

[0125] In order to improve the close fit between the first external electrode 41 and other components or between the second external electrode 42 and other components, a mixed material of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler and carbon filler and resin can also be used as the material constituting the first external electrode 41 and the second external electrode 42.

[0126] It can also be, Figure 1 and Figure 3 As shown, the capacitor array 100 further includes a via conductor 50 disposed inside the sealing layer 120. Figure 1 In the example shown, via conductor 50 is provided on both principal surface sides of sealing layer 120 , but may be provided on only one principal surface side.

[0127] The via conductor 50 extends from the surface of the sealing layer 120 to the cathode layer 20 in the thickness direction (at Figure 1 In the example shown, the second conductor layer 22B is provided. Thus, the second external electrode 42 is electrically connected to the cathode layer 20 of the solid electrolytic capacitor 110 through the via conductor 50 .

[0128] Examples of the material constituting via conductor 50 include low-resistance metals such as silver, gold, and copper.

[0129] The via conductor 50 is formed, for example, as follows. First, the sealing layer 120 is subjected to drilling, laser processing, or the like, to form a hole that reaches the cathode layer 20 (for example, the second conductor layer 22B) from the surface of the sealing layer 120 in the thickness direction. Then, the inner wall surface of the hole formed in the sealing layer 120 is plated or the hole formed in the sealing layer 120 is filled with a conductive paste and then heat-treated, thereby forming the via conductor 50.

[0130] It can also be, Figure 1 and Figure 3As shown in FIG. 1 , the capacitor array 100 further includes through-hole conductors 61 and 62 provided so as to penetrate the sealing layer 120 in the thickness direction. The through-hole conductors 61 and 62 are provided so as to penetrate the first insulating layer 31 in the thickness direction. Figure 1 and Figure 3 In the illustrated example, both the through-hole conductors 61 and 62 are provided, but only one of them may be provided.

[0131] The through-hole conductor 61 is provided inside a first through hole 71 that penetrates the first insulating layer 31 in the thickness direction. Figure 1 and Figure 3 In the example shown, the through-hole conductor 61 is provided so as to penetrate the solid electrolytic capacitor 110 and the sealing layer 120 in the thickness direction. The first external electrode 41 is electrically connected to the anode plate 10 of the solid electrolytic capacitor 110 via the through-hole conductor 61. Figure 1 As shown, the through-hole conductor 61 is electrically connected to the end surface of the anode plate 10 of the solid electrolytic capacitor 110 at the inner wall of the first through-hole 71 (that is, the side wall of the through-hole conductor 61). Figure 1 and Figure 3 In the example shown, the through-hole conductor 61 is provided in a manner to fill the first through-hole 71, but the through-hole conductor 61 only needs to be provided on at least the inner wall surface of the first through-hole 71. When the through-hole conductor 61 is provided on the inner wall surface of the first through-hole 71, it is preferred that the first through-hole 71 is filled with a resin material. In this case, the resin material filling the first through-hole 71 may have conductivity or may not have conductivity.

[0132] The through-hole conductor 62 is provided inside a second through-hole 72 that penetrates the first insulating layer 31 in the thickness direction. Preferably, the diameter of the second through-hole 72 is larger than the diameter of the first through-hole 71. Figure 1 and Figure 3 In the example shown, the through-hole conductor 62 is provided so as to penetrate the solid electrolytic capacitor 110 and the sealing layer 120 in the thickness direction. The through-hole conductor 62 is electrically connected to the cathode layer 20 of the solid electrolytic capacitor 110 via the second external electrode 42 and the via conductor 50. Figure 1 As shown, the through-hole conductor 62 is electrically insulated from the anode plate 10 of the solid electrolytic capacitor 110 at the inner wall of the second through-hole 72 (that is, the side wall of the through-hole conductor 62). Figure 1 and Figure 3In the example shown, the through-hole conductor 62 is provided in a manner to fill the third through-hole 73 having a smaller hole diameter than the second through-hole 72, but the through-hole conductor 62 only needs to be provided on at least the inner wall surface of the third through-hole 73. The hole diameter of the third through-hole 73 may be the same as the hole diameter of the first through-hole 71, may be larger than the hole diameter of the first through-hole 71, or may be smaller than the hole diameter of the first through-hole 71. In the case where the through-hole conductor 62 is provided on the inner wall surface of the third through-hole 73, it is preferred that the third through-hole 73 is filled with a resin material. In this case, the resin material filling the third through-hole 73 may have conductivity or may not have conductivity.

[0133] The cross-sectional shapes of the first through hole 71, the second through hole 72, and the third through hole 73 observed from the thickness direction are not particularly limited, and for example, polygons such as quadrilaterals, circles, ellipses, etc. can be cited. In addition, when the cross-sectional shape is circular, the aperture refers to the diameter, and when the cross-sectional shape is other than circular, the aperture refers to the maximum length passing through the center of the cross section. These through holes may also have a tapered shape in which the aperture becomes smaller in the thickness direction.

[0134] The through-hole conductors 61 and 62 only need to be formed on at least the inner wall surface of the through-hole. The inner wall surface of the through-hole is metallized with a low-resistance metal such as copper, gold or silver. From the perspective of ease of processing, for example, metallization can be performed by electroless copper plating or electrolytic copper plating. In addition, the metallization of the through-hole conductors 61 and 62 is not limited to metallizing only the inner wall surface of the through-hole, and metal or a composite material of metal and resin can also be filled in the through-hole.

[0135] exist Figure 1 and Figure 3 Although not shown, the capacitor array 100 may further include through-hole conductors other than the through-hole conductors 61 and 62. For example, the capacitor array 100 may further include through-hole conductors that are not electrically connected to the anode plate 10 and the cathode layer 20 of the solid electrolytic capacitor 110.

[0136] In the capacitor array 100, it is sufficient as long as there are more than two solid electrolytic capacitors 110 inside the sealing layer 120. The multiple solid electrolytic capacitors 110 can be arranged in a straight line or in a plane when viewed from the thickness direction. In addition, the multiple solid electrolytic capacitors 110 can be arranged regularly or irregularly when viewed from the thickness direction. The size and plane shape of the solid electrolytic capacitors 110 observed from the thickness direction can be the same, or they can be partially or completely different. It can also include two or more solid electrolytic capacitors 110 with different areas observed from the thickness direction.

[0137] Alternatively, the capacitor array 100 includes solid electrolytic capacitors 110 whose planar shapes observed from the thickness direction are not rectangular. In this specification, "rectangle" refers to a square or a rectangle. Therefore, for example, the capacitor array 100 may include solid electrolytic capacitors 110 whose planar shapes are polygons other than rectangles, such as quadrilaterals, triangles, pentagons, hexagons, shapes including curved portions, circles, ellipses, and the like. In this case, the capacitor array 100 may include two or more solid electrolytic capacitors 110 with different planar shapes. In addition, in addition to the solid electrolytic capacitors 110 whose planar shapes are not rectangular, the capacitor array 100 may also include solid electrolytic capacitors 110 whose planar shapes are rectangular, or may not include solid electrolytic capacitors 110 whose planar shapes are rectangular.

[0138] Preferably, if Figure 1 and Figure 3 As shown, the anode plate 10 is disconnected by a slit between at least one group of adjacent solid electrolytic capacitors 110 among the plurality of solid electrolytic capacitors 110. That is, preferably, the slit between at least one group of adjacent solid electrolytic capacitors 110 passes through the anode plate 10 in the thickness direction. The anode plate 10 only needs to be physically disconnected between adjacent solid electrolytic capacitors 110. Therefore, the anode plate 10 can be electrically disconnected or electrically connected between adjacent solid electrolytic capacitors 110.

[0139] The width of the slit between adjacent solid electrolytic capacitors 110 is not particularly limited, but is preferably 15 μm or more, more preferably 30 μm or more, and even more preferably 50 μm or more. On the other hand, the width of the slit between adjacent solid electrolytic capacitors 110 is preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

[0140] The slits between adjacent solid electrolytic capacitors 110 may have a tapered shape in which the width decreases in the thickness direction. In this case, the tapered shape of the slits between adjacent solid electrolytic capacitors 110 may or may not reach the anode plate 10 .

[0141] Preferably, the space between adjacent solid electrolytic capacitors 110 is filled with the same material as the sealing layer 120. Figure 1 As shown, a sealing layer 120 is filled between adjacent solid electrolytic capacitors 110 .

[0142] Alternatively, the space between adjacent solid electrolytic capacitors 110 may be filled with the same material as the stress relaxation layer. For example, when the capacitor array 100 includes a stress relaxation layer, the space between adjacent solid electrolytic capacitors 110 may be filled with the stress relaxation layer.

[0143] As an example of a method for manufacturing a capacitor array according to the present invention, the following will describe the manufacturing method step by step with reference to the accompanying drawings. Figure 1 An example of a method of manufacturing the capacitor array 100 shown will be described.

[0144] Figure 4 This is a perspective view schematically showing an example of a process of preparing an anode plate. Figure 5 It will be Figure 4 The cross-sectional view is an enlarged view of a portion of the anode plate surrounded by a dotted line.

[0145] For example, an anode plate 10 made of a valve metal is prepared. The anode plate 10 has a core 11 (see Figure 1 ); porous layer 12 (refer to Figure 1 and Figure 5 ), which is provided on at least one main surface of the core 11; and a dielectric layer 13 (refer to Figure 5 ) which is disposed on the surface of the porous layer 12.

[0146] For example, by subjecting the anode plate 10 having the porous layer 12 provided on at least one main surface of the core portion 11 to anodization, the dielectric layer 13 can be formed on the surface of the porous layer 12 .

[0147] Alternatively, a chemically formed foil may be prepared as the anode plate 10 in which the dielectric layer 13 is provided on the surface of the porous layer 12 .

[0148] like Figure 4 As shown, in order to divide the anode plate 10 into a plurality of element regions, a first insulating layer 30 is formed on the surface of the porous layer 12. Alternatively, the first insulating layer 30 is formed on the surface of the dielectric layer 13 on the porous layer 12. Preferably, the first insulating layer 30 is formed in a manner that fills the pores (recesses) of the porous layer 12 or the dielectric layer 13.

[0149] Furthermore, the first insulating layer 31 may be formed on the surface of the porous layer 12 in at least one element region. In this case, it is preferred that the first insulating layer 31 is formed separately from the first insulating layer 30. The first insulating layer 31 may be formed on the surface of the dielectric layer 13 on the porous layer 12. It is preferred that the first insulating layer 31 is formed in a manner that fills the pores (recesses) of the porous layer 12 or the dielectric layer 13.

[0150] Next, the cathode layer 20 is formed on the surface of the dielectric layer 13 in the element region partitioned by the first insulating layer 30. Alternatively, the cathode layer 20 may be formed so as to extend to the surface of the first insulating layer 30.

[0151] The step of forming cathode layer 20 includes the step of forming solid electrolyte layer 21 containing a conductive polymer on the surface of dielectric layer 13 .

[0152] The step of forming solid electrolyte layer 21 includes, for example, a step of forming first conductive polymer layer 21A, a step of forming second conductive polymer layer 21B, and a step of forming third conductive polymer layer 21C.

[0153] Figure 6 This is a cross-sectional view schematically showing an example of the process of forming the first conductive polymer layer.

[0154] like Figure 6 As shown, first conductive polymer layer 21A is formed inside the pores (recesses) of dielectric layer 13. First conductive polymer layer 21A may be formed to cover the entire pores of dielectric layer 13 or may be formed to cover only a portion of the pores of dielectric layer 13.

[0155] In the step of forming first conductive polymer layer 21A, a layer containing the first conductive polymer is formed using a liquid containing the first conductive polymer. Preferably, first conductive polymer layer 21A is formed using a liquid in which the first conductive polymer is dissolved.

[0156] Preferably, the first conductive polymer layer 21A is formed by applying a liquid containing the first conductive polymer. Specifically, the first conductive polymer layer 21A is formed by applying a liquid containing the first conductive polymer to the surface of the anode plate 10 and drying it, and the liquid containing the first conductive polymer is preferably a liquid obtained by dissolving the first conductive polymer. The coating and drying can be repeated any number of times according to the required characteristics, but if the resistance to delamination, the minimization of cost, etc. are considered, it is preferably repeated more than once and less than three times.

[0157] Figure 7 This is a cross-sectional view schematically showing an example of the process of forming the second conductive polymer layer.

[0158] like Figure 7 As shown in FIG. 1 , the second conductive polymer layer 21B covering the first conductive polymer layer 21A is formed inside the pores (concave portions) of the dielectric layer 13. The second conductive polymer layer 21B may be formed so as to cover the entire first conductive polymer layer 21A, or may be formed so as to cover a portion of the first conductive polymer layer 21A. The second conductive polymer layer 21B may also be formed so as to fill the pores (concave portions) of the dielectric layer 13.

[0159] In the step of forming the second conductive polymer layer 21B, a layer in which the second conductive polymer and the insulating material are mixed is formed using a liquid containing the second conductive polymer and a liquid containing an insulating material, wherein the insulating material contains an OH group, a COOH group, a CO group or an NH2 group in the molecule, has hygroscopicity, and has no doping function with respect to the conductive polymer. Preferably, the second conductive polymer layer 21B is formed using a liquid in which the second conductive polymer having a particle size larger than that of the first conductive polymer is dispersed and a liquid in which the insulating material is dissolved.

[0160] The particle size of the conductive polymer can be measured by dynamic light scattering (DLS).

[0161] Preferably, the second conductive polymer layer 21B is formed by simultaneously applying a liquid containing a second conductive polymer and a liquid containing an insulating material. Specifically, the second conductive polymer layer 21B is formed by simultaneously applying a liquid containing a second conductive polymer and a liquid containing an insulating material to the surface of the anode plate 10 formed with the first conductive polymer layer 21A and drying the liquid. The liquid containing the second conductive polymer is preferably a liquid obtained by dispersing the second conductive polymer, and the liquid containing the insulating material is preferably a liquid obtained by dissolving the insulating material. The coating and drying can be repeated any number of times according to the required characteristics, but for example, in the case of forming a cathode layer containing a metal or forming a sealing layer, it is preferably more than one and less than five times from the viewpoint of improving the resistance to delamination.

[0162] Furthermore, the simultaneous application of the liquid containing the second conductive polymer and the liquid containing the insulating material means applying one liquid before drying the other liquid, and the method is not particularly limited.

[0163] In the method of simultaneously applying a liquid containing a second conductive polymer and a liquid containing an insulating material, even in the case of a combination of materials such that the dispersion stability of the second conductive polymer is deteriorated due to the influence of the insulating material, it is possible to promote drying and fixing before the materials coagulate, compared to the method of premixing the materials.

[0164] Figure 8 This is a perspective view schematically showing an example of a step of forming the third conductive polymer layer. Fig. 9 It will be Figure 8 The cross-sectional view is an enlarged view of a portion of the anode plate surrounded by a dotted line.

[0165] like Figure 8 and Fig. 9As shown in FIG. 1 , a third conductive polymer layer 21C is formed on the surface of the anode plate 10 so as to cover at least the second conductive polymer layer 21B. Alternatively, the third conductive polymer layer 21C may be formed so as to cover not only the second conductive polymer layer 21B but also the first conductive polymer layer 21A. By forming the third conductive polymer layer 21C, the solid electrolyte layer 21 is formed. Figure 8 In the illustrated example, the solid electrolyte layer 21 is formed on the surface of the dielectric layer 13 in the element region partitioned by the first insulating layer 30 .

[0166] In the step of forming third conductive polymer layer 21C, a layer containing the third conductive polymer is formed using a liquid containing the third conductive polymer. Preferably, a liquid containing a binder in addition to the third conductive polymer is used.

[0167] The third conductive polymer layer 21C is formed, for example, by applying a liquid containing the third conductive polymer to the surface of the anode plate 10 formed with the first conductive polymer layer 21A and the second conductive polymer layer 21B and drying it. Alternatively, the third conductive polymer layer 21C may be formed by forming a polymer film of the third conductive polymer on the surface of the anode plate 10 formed with the first conductive polymer layer 21A and the second conductive polymer layer 21B using a liquid containing a monomer such as 3,4-ethylenedioxythiophene.

[0168] In a sheet-like capacitor array having many interfaces of different materials and a dimension in the thickness direction smaller than the dimension in the plane direction, delamination due to stress is likely to occur. Therefore, in order to improve the anchoring effect at the pores, it is preferred to minimize the amount of conductive polymer contained in the solid electrolyte layer 21.

[0169] Preferably, the step of forming the cathode layer 20 further includes the step of forming the conductor layer 22 on the surface of the solid electrolyte layer 21 .

[0170] The step of forming the conductor layer 22 includes, for example, a step of forming the first conductor layer 22A on the surface of the solid electrolyte layer 21 and a step of forming the second conductor layer 22B on the surface of the first conductor layer 22A.

[0171] Fig.10 It is a perspective view schematically showing an example of the process of forming the first conductive layer.

[0172] like Fig.10 As shown in FIG. 1 , a first conductor layer 22A is formed on the surface of the solid electrolyte layer 21. The first conductor layer 22A is, for example, a conductive resin layer containing a conductive filler.

[0173] Fig.11It is a perspective view schematically showing an example of the process of forming the second conductive layer.

[0174] like Fig.11 As shown, the second conductive layer 22B is formed on the surface of the first conductive layer 22A. Thus, the conductive layer 22 is formed. The second conductive layer 22B is, for example, a conductive resin layer containing a metal filler. In this way, the process of forming the conductive layer 22 may also include the process of forming the conductive resin layer containing a metal filler.

[0175] As an example, the conductor layer 22 includes a carbon layer as the first conductor layer 22A and a copper layer as the second conductor layer 22B.

[0176] Fig.12 This is a perspective view schematically showing an example of a process of cutting an anode plate having a cathode layer formed thereon.

[0177] like Fig.12 As shown, the anode plate 10 formed with the cathode layer 20 is cut to divide the element region, thereby separating into a plurality of solid electrolytic capacitors 110 .

[0178] Examples of a method for cutting the anode plate 10 on which the cathode layer 20 is formed include laser processing and cutting processing.

[0179] Preferably, if Fig.12 As shown, the anode plate 10 is disconnected between at least one group of adjacent solid electrolytic capacitors 110 among the plurality of solid electrolytic capacitors 110. That is, preferably, the anode plate 10 is disconnected between at least one group of adjacent solid electrolytic capacitors 110 so as to penetrate the anode plate 10 in the thickness direction.

[0180] When forming the first insulating layer 31 , through-hole conductors 61 and 62 may be formed to penetrate the first insulating layer 31 in the thickness direction. For example, the through-hole conductor 61 may be formed inside the first through-hole 71 , and the through-hole conductor 62 may be formed inside the second through-hole 72 .

[0181] Fig.13 It is a perspective view schematically showing an example of a process of forming the second through hole.

[0182] like Fig.13 As shown, a second through hole 72 penetrating the first insulating layer 31 in the thickness direction is formed as necessary.

[0183] As a method of forming the second through hole 72 , for example, laser processing, drilling processing, etc. can be cited.

[0184] Fig.14 It is a perspective view schematically showing an example of a step of forming a sealing layer.

[0185] like Fig.14 As shown, for example, an insulating material is provided by press working or the like, so that the sealing layer 120 is formed in a manner covering the plurality of solid electrolytic capacitors 110. The sealing layer 120 is formed in a manner covering the cathode layer 20, the first insulating layer 30, and the first insulating layer 31. Preferably, the sealing layer 120 is formed in a manner covering the entire periphery of the solid electrolytic capacitor 110, that is, in a manner covering the top, bottom, left, and right sides of the solid electrolytic capacitor 110.

[0186] By forming the sealing layer 120 , the sealing layer 120 may be filled between adjacent solid electrolytic capacitors 110 . The sealing layer 120 can reliably separate the anode plates 10 from each other.

[0187] Furthermore, when forming the second through hole 72 , the second through hole 72 may be filled with the sealing layer 120 .

[0188] Fig.15 It is a perspective view schematically showing an example of a process of forming a first through hole.

[0189] like Fig.15 As shown in FIG. 1 , a first through hole 71 is formed to penetrate the first insulating layer 31 in the thickness direction as necessary. The hole diameter of the first through hole 71 is smaller than the hole diameter of the second through hole 72 .

[0190] As a method of forming the first through hole 71 , for example, laser processing, drilling processing, etc. can be cited.

[0191] It can also be, Fig.15 As shown, a third through hole 73 having a smaller diameter than the second through hole 72 is also formed. The diameter of the third through hole 73 may be the same as the diameter of the first through hole 71, larger than the diameter of the first through hole 71, or smaller than the diameter of the first through hole 71.

[0192] As a method of forming the third through hole 73, for example, laser processing, drilling processing, etc. can be cited.

[0193] Fig.16 It is a perspective view schematically showing an example of a process of forming a through-hole conductor.

[0194] like Fig.16 As shown, the through-hole conductor 61 is formed inside the first through-hole 71 , and the through-hole conductor 62 is formed inside the second through-hole 72 .

[0195] The through-hole conductor 61 is formed to penetrate the solid electrolytic capacitor 110 and the sealing layer 120 in the thickness direction. Preferably, the through-hole conductor 61 is electrically connected to the end surface of the anode plate 10 of the solid electrolytic capacitor 110 at the inner wall of the first through-hole 71 (i.e., the side wall of the through-hole conductor 61). Fig.16 In the illustrated example, the through-hole conductor 61 is formed so as to fill the first through-hole 71 , but the through-hole conductor 61 only needs to be formed on at least the inner wall surface of the first through-hole 71 .

[0196] The through-hole conductor 62 is formed to penetrate the solid electrolytic capacitor 110 and the sealing layer 120 in the thickness direction. Preferably, the through-hole conductor 62 is electrically insulated from the anode plate 10 of the solid electrolytic capacitor 110 at the inner wall of the second through-hole 72 (i.e., the side wall of the through-hole conductor 62). Fig.16 In the illustrated example, the through-hole conductor 62 is formed so as to fill the third through-hole 73 , but the through-hole conductor 62 only needs to be formed on at least the inner wall surface of the third through-hole 73 .

[0197] like Fig.16 As shown, a sealing layer 120 may be filled between the through-hole conductor 62 and the anode plate 10 . The sealing layer 120 reliably insulates the through-hole conductor 62 from the anode plate 10 at the inner wall of the second through hole 72 .

[0198] Fig.17 It is a perspective view schematically showing an example of a process of forming a via conductor.

[0199] It can also be, Fig.17 As shown, via conductor 50 is formed on sealing layer 120 .

[0200] Then, by forming the first external electrode 41 and the second external electrode 42 (not shown), it is possible to manufacture Figure 1 A capacitor array 100 is shown.

[0201] As described above, when manufacturing the capacitor array 100, laser processing, cutting processing, etc. can be cited as a method of disconnecting the anode plate 10 formed with the cathode layer 20. Among them, by using laser processing, the element region can be formed into a free shape. Therefore, it is possible to configure two or more solid electrolytic capacitors 110 with different element regions in one capacitor array 100, configure slits in a manner that is not applied to the entire capacitor array 100, and configure solid electrolytic capacitors 110 whose plane shape of the cathode layer 20 is not rectangular.

[0202] Fig.18 FIG. 1 is a cross-sectional view schematically showing another example of the capacitor array of the present invention. Fig.19 It will be Fig.18A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged.

[0203] Fig.18 The capacitor array 100A shown in the figure further includes a second insulating layer 32 provided inside the pores of the dielectric layer 13 so as to cover a part of the solid electrolyte layer 21. Fig.18 The capacitor array 100A shown has Figure 1 The capacitor array 100 shown has a general structure.

[0204] Preferably, the second insulating layer 32 is provided so as to cover the local part of the solid electrolyte layer 21 located near the first insulating layer 30 or 31. That is, preferably, the second insulating layer 32 is provided so as to cover the end of the solid electrolyte layer 21. In the case where both the first insulating layers 30 and 31 are provided, the second insulating layer 32 may be provided so as to cover both the local part of the solid electrolyte layer 21 located near the first insulating layer 30 and the local part of the solid electrolyte layer 21 located near the first insulating layer 31, or the second insulating layer 32 may be provided so as to cover either the local part of the solid electrolyte layer 21 located near the first insulating layer 30 or the local part of the solid electrolyte layer 21 located near the first insulating layer 31.

[0205] The second insulating layer 32 may extend from the solid electrolyte layer 21 to cover the entire or a part of the first insulating layer 30. Similarly, the second insulating layer 32 may extend from the solid electrolyte layer 21 to cover the entire or a part of the first insulating layer 31.

[0206] Around the first insulating layer 30, the wettability between the solid electrolyte layer 21 and the first insulating layer 30 is poor, so the formation rate of the solid electrolyte layer 21 is easily reduced. The same is true around the first insulating layer 31. Although the conductive polymer exists, the state in which the solid electrolyte layer 21 is not formed is an undesirable state in the mechanism of expansion and capacity change caused by water intrusion. Therefore, by forming the second insulating layer 32 inside the pores of the dielectric layer 13 in a manner that covers a part of the solid electrolyte layer 21, the expansion can be physically suppressed.

[0207] In particular, when a plurality of solid electrolytic capacitors 110 are present inside the sealing layer 120 as in the capacitor array 100A, the surface area ratio of the first insulating layers 30 and 31 increases, and thus the influence of the capacitance variation caused by the reduction in the formation rate of the solid electrolyte layer 21 becomes significant. Therefore, forming the second insulating layer 32 becomes an effective means.

[0208] On the other hand, if the second insulating layer 32 is provided in an excessively large range, the conductive path itself is damaged, thereby increasing resistance. Therefore, it is preferred that the second insulating layer 32 is provided in a range of 1 μm to 100 μm from the end of the first insulating layer 30 or 31 toward the solid electrolyte layer 21.

[0209] The second insulating layer 32 contains an insulating material.

[0210] Preferably, the second insulating layer 32 is formed of a resin. As the resin constituting the second insulating layer 32, for example, insulating resins such as polyphenylsulfone resin, polyethersulfone resin, cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), polyimide resin, polyamide-imide resin, epoxy resin, and derivatives or precursors thereof can be cited. The second insulating layer 32 may be composed of the same resin as the resin of the first insulating layer 30 or 31, or may be composed of a resin different from the resin of the first insulating layer 30 or 31.

[0211] If the second insulating layer 32 contains an inorganic filler, there is a possibility that an effective portion of the solid electrolytic capacitor 110 is adversely affected. Therefore, it is preferable that the second insulating layer 32 is formed of a single type of resin.

[0212] The second insulating layer 32 can be formed, for example, by applying a masking material such as a composition containing an insulating resin so as to partially cover the solid electrolyte layer 21 by a method such as sponge transfer, screen printing, dispenser coating, or inkjet printing.

[0213] Preferably, the second insulating layer 32 fills the inside of the pores of the dielectric layer 13. The second insulating layer 32 may be provided on the surface of the anode plate 10.

[0214] The capacitor array of the present invention can be appropriately used as a constituent material of a composite electronic component. Such a composite electronic component includes, for example: the capacitor array of the present invention; an external electrode disposed outside the capacitor array and connected to the anode plate and cathode layer of the solid electrolytic capacitor, respectively; and an electronic component connected to the external electrode.

[0215] In the composite electronic component, the electronic component connected to the external electrode may be either a passive element or an active element. Both the passive element and the active element may be connected to the external electrode, or either the passive element or the active element may be connected to the external electrode. In addition, a composite of the passive element and the active element may be connected to the external electrode.

[0216] Examples of passive components include inductors, etc. Examples of active components include memories, GPUs (Graphical Processing Units), CPUs (Central Processing Units), MPUs (Micro Processing Units), and PMICs (Power Management ICs).

[0217] The capacitor array of the present invention has a sheet-like shape as a whole. Therefore, in the composite electronic component, the capacitor array can be treated like a mounting substrate, and the electronic components can be mounted on the capacitor array. Moreover, by setting the shape of the electronic components mounted on the capacitor array to be sheet-like, the capacitor array and the electronic components can be connected in the thickness direction via through-hole conductors that penetrate each electronic component in the thickness direction. As a result, active components and passive components can be configured as batch modules.

[0218] For example, the capacitor array of the present invention can be electrically connected between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied, thereby forming a switching regulator.

[0219] In the composite electronic component, a circuit layer may be formed on any surface of a capacitor matrix sheet in which a plurality of capacitors of the present invention are further arranged, and then connected to a passive element or an active element.

[0220] Alternatively, the capacitor array of the present invention may be arranged in a cavity pre-formed in the substrate, embedded in resin, and then a circuit layer may be formed on the resin. Alternatively, other electronic components (passive or active components) may be mounted in other cavities of the substrate.

[0221] Alternatively, the capacitor array of the present invention may be mounted on a smooth carrier such as a wafer or glass, and after the outer layer is formed from resin, a circuit layer is formed, and then connected to passive elements or active elements.

[0222] The following contents are disclosed in this specification.

[0223] <1>

[0224] A solid electrolytic capacitor, wherein:

[0225] The solid electrolytic capacitor includes:

[0226] an anode plate comprising a core, a porous layer provided on at least one main surface of the core, and a dielectric layer provided on a surface of the porous layer; and

[0227] a cathode layer disposed on the surface of the dielectric layer;

[0228] The cathode layer includes a solid electrolyte layer provided on the surface of the dielectric layer.

[0229] The solid electrolyte layer includes a conductive polymer layer in which a conductive polymer and an insulating material are mixed inside the pores of the dielectric layer.

[0230] The insulating material is a material that contains an OH group, a COOH group, a CO group or an NH 2 group in a molecule, has hygroscopicity, and has no doping function with respect to the conductive polymer.

[0231] <2>

[0232] A solid electrolytic capacitor according to <1>, wherein:

[0233] The solid electrolytic capacitor further includes a first insulating layer provided in a region of the surface of the porous layer where the cathode layer is not formed.

[0234] <3>

[0235] A solid electrolytic capacitor according to <2>, wherein:

[0236] The solid electrolytic capacitor further includes a second insulating layer provided inside the pores of the dielectric layer so as to cover a portion of the solid electrolyte layer.

[0237] <4>

[0238] A solid electrolytic capacitor according to <3>, wherein:

[0239] The second insulating layer is provided in a range of 1 μm to 100 μm from an end portion of the first insulating layer toward the solid electrolyte layer.

[0240] <5>

[0241] The solid electrolytic capacitor according to any one of <2> to <4>, wherein

[0242] The first insulating layer is provided so as to surround the cathode layer when viewed in the thickness direction.

[0243] <6>

[0244] The solid electrolytic capacitor according to any one of <2> to <4>, wherein

[0245] The first insulating layer is provided inside the cathode layer when viewed in the thickness direction.

[0246] <7>

[0247] The solid electrolytic capacitor according to any one of <1> to <6>, wherein

[0248] The solid electrolytic capacitor also includes:

[0249] A sealing layer provided in a manner covering the solid electrolytic capacitor;

[0250] A first external electrode and a second external electrode, which are arranged outside the sealing layer;

[0251] a via conductor provided inside the sealing layer; and

[0252] a through-hole conductor provided so as to penetrate the sealing layer in the thickness direction;

[0253] The through-hole conductor is electrically connected to the end surface of the anode plate of the solid electrolytic capacitor at its side wall.

[0254] The first external electrode is electrically connected to the anode plate of the solid electrolytic capacitor via the through-hole conductor.

[0255] The second external electrode is electrically connected to the cathode layer of the solid electrolytic capacitor through the via conductor.

[0256] <8>

[0257] A capacitor array, wherein:

[0258] The capacitor array includes:

[0259] A solid electrolytic capacitor as described in any one of <1> to <6>;

[0260] A sealing layer provided in a manner covering the solid electrolytic capacitor;

[0261] A first external electrode and a second external electrode, which are arranged outside the sealing layer;

[0262] a via conductor provided inside the sealing layer; and

[0263] a through-hole conductor provided so as to penetrate the sealing layer in the thickness direction;

[0264] There are two or more solid electrolytic capacitors in the sealing layer.

[0265] The through-hole conductor is electrically connected to the end surface of the anode plate of the solid electrolytic capacitor at its side wall.

[0266] The first external electrode is electrically connected to the anode plate of the solid electrolytic capacitor via the through-hole conductor.

[0267] The second external electrode is electrically connected to the cathode layer of the solid electrolytic capacitor through the via conductor.

[0268] <9>

[0269] The capacitor array according to <8>, wherein:

[0270] The space between adjacent solid electrolytic capacitors is filled with the same material as the sealing layer.

[0271] Example

[0272] Hereinafter, embodiments of the solid electrolytic capacitor and capacitor array of the present invention will be described in more detail. However, the present invention is not limited to these embodiments.

[0273] (Example 1)

[0274] In Example 1, the Figure 1 A capacitor array 100 is shown.

[0275] An aluminum sheet having a porous layer and an oxide film on both sides is prepared, and an insulating resin is used to form a shielding layer (first insulating layer) surrounding an effective part (element region) that becomes a capacitance part of a solid electrolytic capacitor and an insulating support layer (first insulating layer) for forming a through-hole conductor in the effective part by coating. The first conductive polymer layer is formed on the surface of the dielectric layer by performing the following process multiple times: a conductive polymer ink obtained by dissolving a conductive polymer represented by poly(3,4-ethylenedioxythiophene) and soluble in a solvent as the first conductive polymer is coated on the formed effective part, and then dried.

[0276] Next, the following process is performed multiple times to form a second conductive polymer layer in which an insulating material is mixed and present in a region continuous with the conductive region: a dispersion obtained by dispersing a second conductive polymer different from the first conductive polymer and a solution obtained by dissolving an insulating material are simultaneously applied and then dried, the insulating material being hygroscopic and having no doping function relative to the conductive polymer contained in the solid electrolyte layer. As the second conductive polymer, the following conductive polymer is used: represented by poly(3,4-ethylenedioxythiophene), having a larger particle size than the first conductive polymer, being insoluble in solvents, but having high heat resistance. As the insulating material, a hygroscopic phenolic material is used.

[0277] Next, a third conductive polymer layer is formed by coating the effective portion with a third conductive polymer, thereby forming a solid electrolyte layer. After that, as a conductor layer, a first conductor layer and a second conductor layer are formed by coating them separately. A carbon layer is formed as the first conductor layer, and a copper layer is formed as the second conductor layer. A solid electrolytic capacitor sheet is obtained by the above method.

[0278] Resin sheets are attached to the upper and lower surfaces of the obtained solid electrolytic capacitor sheet, and pressure-bonded at a temperature above the glass transition temperature to obtain a capacitor array sheet with a smooth surface.

[0279] After the capacitor array sheet is cut into individual solid electrolytic capacitors, the resin sheet is again pressed at a temperature equal to or higher than the glass transition temperature to fill the formed grooves (slits).

[0280] A hole is formed from the sealing layer formed of a resin sheet toward the second conductor layer, and the inside of the formed hole is filled with a conductive material to form a via conductor that serves as a lead-out electrode of the cathode.

[0281] Furthermore, through holes were formed in the insulating support layer (first insulating layer), and the formed through holes and the exposed wall surface of the aluminum sheet were plated to form a through-hole conductor that would serve as an extraction electrode of the anode.

[0282] The capacitor array sheet obtained by the above method was cut into individual pieces, thereby obtaining the solid electrolytic capacitor of Example 1.

[0283] In the solid electrolytic capacitor of Example 1, the capacitance fluctuation due to swelling due to moisture absorption can be suppressed by the swelling of the insulating material.

[0284] (Example 2)

[0285] In Example 2, the production Fig.18 Capacitor array 100A is shown.

[0286] An aluminum sheet having a porous layer and an oxide film on both sides is prepared, and an insulating resin is used to form a shielding layer (first insulating layer) surrounding an effective part (element region) that becomes a capacitance part of a solid electrolytic capacitor and an insulating support layer (first insulating layer) for forming a through-hole conductor in the effective part by coating. The first conductive polymer layer is formed on the surface of the dielectric layer by performing the following process multiple times: a conductive polymer ink obtained by dissolving a conductive polymer represented by poly(3,4-ethylenedioxythiophene) and soluble in a solvent as the first conductive polymer is coated on the formed effective part, and then dried.

[0287] Next, the following process is performed multiple times to form a second conductive polymer layer in which an insulating material is mixed and present in a region continuous with the conductive region: a dispersion obtained by dispersing a second conductive polymer different from the first conductive polymer and a solution obtained by dissolving an insulating material are simultaneously applied and then dried, the insulating material being hygroscopic and having no doping function relative to the conductive polymer contained in the solid electrolyte layer. As the second conductive polymer, the following conductive polymer is used: represented by poly(3,4-ethylenedioxythiophene), having a larger particle size than the first conductive polymer, being insoluble in solvents, but having high heat resistance. As the insulating material, a hygroscopic phenolic material is used.

[0288] Next, a third conductive polymer is applied to the effective portion to form a third conductive polymer layer, thereby forming a solid electrolyte layer. When forming the solid electrolyte layer, in order to suppress the risk of short circuit caused by direct contact between the aluminum sheet and the conductor layer described later, a liquid having a higher viscosity than the liquid used to form the first conductive polymer layer and the second conductive polymer layer is used, and the liquid is applied in a manner that the aluminum sheet is not exposed on the surface.

[0289] After forming the solid electrolyte layer, an insulating resin was applied so that the coating area expanded by 50 μm from the shielding layer (first insulating layer) and the insulating support layer (first insulating layer) toward the effective portion, thereby forming a second insulating layer.

[0290] Then, as the conductor layer, the first conductor layer and the second conductor layer are formed by coating each other. A carbon layer is formed as the first conductor layer, and a copper layer is formed as the second conductor layer. By the above method, a solid electrolytic capacitor sheet is obtained.

[0291] Resin sheets are attached to the upper and lower surfaces of the obtained solid electrolytic capacitor sheet, and pressure-bonded at a temperature above the glass transition temperature to obtain a capacitor array sheet with a smooth surface.

[0292] After the capacitor array sheet is cut into individual solid electrolytic capacitors, the resin sheet is again pressed at a temperature equal to or higher than the glass transition temperature to fill the formed grooves (slits).

[0293] A hole is formed from the sealing layer formed of a resin sheet toward the second conductor layer, and the inside of the formed hole is filled with a conductive material to form a via conductor that serves as a lead-out electrode of the cathode.

[0294] Furthermore, through holes were formed in the insulating support layer (first insulating layer), and the formed through holes and the exposed wall surface of the aluminum sheet were plated to form a through-hole conductor that would serve as an extraction electrode of the anode.

[0295] The capacitor array sheet obtained by the above method was cut into individual pieces, thereby obtaining the solid electrolytic capacitor of Example 2.

[0296] In the solid electrolytic capacitor of Example 2, the shielding layer vicinity is filled with insulating resin in addition to Example 1, so that the shielding layer can be physically prevented from swelling. However, if the entire surface is filled, the conductivity decreases, so it is preferred to selectively fill only the shielding layer vicinity.

[0297] (Comparative Example 1)

[0298] In Comparative Example 1, Fig. 20 The capacitor array 100B is shown.

[0299] Fig. 20 1 is a cross-sectional view schematically showing an example of a capacitor array according to Comparative Example 1. Fig.21 It will be Fig. 20 A cross-sectional view of a capacitor array is shown with the portion surrounded by a dotted line enlarged.

[0300] An aluminum sheet having a porous layer and an oxide film on both sides is prepared, and an insulating resin is used to form a shielding layer (first insulating layer) surrounding an effective part (element region) that becomes a capacitance part of a solid electrolytic capacitor and an insulating support layer (first insulating layer) for forming a through-hole conductor in the effective part by coating. The first conductive polymer layer is formed on the surface of the dielectric layer by performing the following process multiple times: a dispersion obtained by dispersing a second conductive polymer is coated on the formed effective part, and then dried.

[0301] Next, a third conductive polymer layer is formed on the effective portion to form a solid electrolyte layer. After that, as a conductor layer, the first conductor layer and the second conductor layer are formed by coating them separately. A carbon layer is formed as the first conductor layer, and a copper layer is formed as the second conductor layer. By the above method, a solid electrolytic capacitor sheet is obtained.

[0302] Resin sheets are attached to the upper and lower surfaces of the obtained solid electrolytic capacitor sheet, and pressure-bonded at a temperature above the glass transition temperature to obtain a capacitor array sheet with a smooth surface.

[0303] After the capacitor array sheet is cut into individual solid electrolytic capacitors, the resin sheet is again pressed at a temperature equal to or higher than the glass transition temperature to fill the formed grooves (slits).

[0304] A hole is formed from the sealing layer formed of a resin sheet toward the second conductor layer, and the inside of the formed hole is filled with a conductive material to form a via conductor that serves as a lead-out electrode of the cathode.

[0305] Furthermore, through holes were formed in the insulating support layer (first insulating layer), and the formed through holes and the exposed wall surface of the aluminum sheet were plated to form a through-hole conductor that would serve as an extraction electrode of the anode.

[0306] The capacitor array sheet obtained by the above method was cut into individual pieces, thereby obtaining the solid electrolytic capacitor of Comparative Example 1.

[0307] The solid electrolytic capacitors of Example 2 and Comparative Example 1 were left in an atmosphere of temperature 22° C. and humidity 60% for 48 hours as a reference, and the capacity change rate (ΔCap) after leaving for 48 hours was measured by changing only the humidity.

[0308] Fig. 22 Graph showing the relationship between humidity and capacity variation rate of the solid electrolytic capacitors of Example 2 and Comparative Example 1.

[0309] according to Fig. 22 It is found that, in the solid electrolytic capacitor of Example 2, the capacitance variation rate under a high humidity environment is suppressed compared with the solid electrolytic capacitor of Comparative Example 1.

[0310] Description of Reference Numerals

[0311] 10. Anode plate; 11. Core; 12. Porous layer; 13. Dielectric layer; 20. Cathode layer; 21. Solid electrolyte layer; 21A. 1st conductive polymer layer; 21B. 2nd conductive polymer layer; 21C. 3rd conductive polymer layer; 22. Conductor layer; 22A. 1st conductive layer; 22B. 2nd conductive layer; 30, 31. 1st insulating layer; 32. 2nd insulating layer; 41. 1st external electrode; 42. 2nd external electrode; 50. Via conductor; 61, 62. Through-hole conductor; 71. 1st through hole; 72. 2nd through hole; 73. 3rd through hole; 100, 100A, 100B. Capacitor array; 110. Solid electrolytic capacitor; 120. Sealing layer.

Claims

1. A solid electrolytic capacitor, wherein: The solid electrolytic capacitor includes: an anode plate comprising a core, a porous layer provided on at least one main surface of the core, and a dielectric layer provided on a surface of the porous layer; and a cathode layer disposed on a surface of the dielectric layer, The cathode layer includes a solid electrolyte layer provided on the surface of the dielectric layer, The solid electrolyte layer includes a conductive polymer layer in which a conductive polymer and an insulating material are mixed inside the pores of the dielectric layer. The insulating material is a material that contains an OH group, a COOH group, a CO group, or an NH 2 group in a molecule, has hygroscopicity, and has no doping function with respect to the conductive polymer.

2. The solid electrolytic capacitor according to claim 1, wherein: The solid electrolytic capacitor further includes a first insulating layer provided in a region of the surface of the porous layer where the cathode layer is not formed.

3. The solid electrolytic capacitor according to claim 2, wherein: The solid electrolytic capacitor further includes a second insulating layer provided inside the pores of the dielectric layer so as to cover a portion of the solid electrolyte layer.

4. The solid electrolytic capacitor according to claim 3, wherein: The second insulating layer is provided in a range of 1 μm to 100 μm from an end of the first insulating layer toward the solid electrolyte layer.

5. The solid electrolytic capacitor according to any one of claims 2 to 4, wherein: The first insulating layer is provided so as to surround the cathode layer when viewed in the thickness direction.

6. The solid electrolytic capacitor according to any one of claims 2 to 4, wherein: The first insulating layer is provided inside the cathode layer when viewed in the thickness direction.

7. The solid electrolytic capacitor according to any one of claims 1 to 6, wherein: The solid electrolytic capacitor also includes: A sealing layer, which is arranged in a manner of covering the solid electrolytic capacitor; a first external electrode and a second external electrode, which are arranged outside the sealing layer; a via conductor disposed inside the sealing layer; and a through-hole conductor provided so as to penetrate the sealing layer in the thickness direction, The through-hole conductor is electrically connected to the end surface of the anode plate of the solid electrolytic capacitor at its side wall. The first external electrode is electrically connected to the anode plate of the solid electrolytic capacitor via the through-hole conductor. The second external electrode is electrically connected to the cathode layer of the solid electrolytic capacitor through the via conductor.

8. A capacitor array, wherein: The capacitor array includes: The solid electrolytic capacitor according to any one of claims 1 to 6; A sealing layer, which is arranged in a manner of covering the solid electrolytic capacitor; a first external electrode and a second external electrode, which are arranged outside the sealing layer; a via conductor disposed inside the sealing layer; and a through-hole conductor provided so as to penetrate the sealing layer in the thickness direction, There are two or more solid electrolytic capacitors inside the sealing layer, The through-hole conductor is electrically connected to the end surface of the anode plate of the solid electrolytic capacitor at its side wall. The first external electrode is electrically connected to the anode plate of the solid electrolytic capacitor via the through-hole conductor. The second external electrode is electrically connected to the cathode layer of the solid electrolytic capacitor through the via conductor.

9. The capacitor array according to claim 8, wherein: The space between adjacent solid electrolytic capacitors is filled with the same material as the sealing layer.

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