Capacitor element

Abstract

This capacitor element 1 comprises: a capacitor unit 10 that includes an anode plate 11 having a porous part 11B on at least one main surface of a core part 11A, a dielectric layer 13 provided on the surface of the porous part 11B, and a cathode layer 12 provided on the surface of the dielectric layer 13; and a sealing layer 30 that seals the capacitor unit 10, where inside the sealing layer 30, an insulation layer 40 having a lower Young's modulus than the sealing layer 30 is provided at a position not in contact with the cathode layer 12.

Description

[Technical Field]

[0001] The present invention relates to a capacitor element. [Background technology]

[0002] Patent Document 1 discloses a capacitor array including multiple solid electrolytic capacitor elements formed by dividing a single solid electrolytic capacitor sheet, a sheet-like first sealing layer, and a sheet-like second sealing layer. The solid electrolytic capacitor sheet includes an anode plate made of a valve metal, a porous layer provided on at least one main surface of the anode plate, a dielectric layer provided on the surface of the porous layer, and a cathode layer including a solid electrolyte layer provided on the surface of the dielectric layer, and has first and second main surfaces opposing each other in the thickness direction. The first main surface side of each of the multiple solid electrolytic capacitor elements is disposed on the first sealing layer. The second sealing layer is disposed so as to cover the multiple solid electrolytic capacitor elements on the first sealing layer from the second main surface side. The solid electrolytic capacitor elements are separated by slit-shaped sheet removal portions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-167361 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes that a stress relaxation layer may be provided between the solid electrolytic capacitor element and the first sealing layer or the second sealing layer. According to Patent Document 1, by providing the stress relaxation layer in the above-mentioned location, it is possible to relieve stress generated between the inside and outside of the capacitor array without impairing the capabilities (resistance, blocking performance, etc.) required for the conductor and insulating parts arranged at the outermost part of the solid electrolytic capacitor element or the capabilities required for the sealing layer (easy adhesion with wiring, easy to form smooth, etc.).

[0005] Cross sections of capacitor arrays including stress relaxation layers are shown in Figures 25, 27, and 29 of Patent Document 1. However, simply providing stress relaxation layers at the locations shown in Figures 25, 27, and 29 of Patent Document 1 may result in peeling at the effective capacitance portion of the solid electrolytic capacitor element, such as peeling of the cathode layer from the anode plate.

[0006] The above problem is not limited to a structure in which a plurality of capacitor units are disposed inside a sealing layer, but also occurs in a structure in which a single capacitor unit is disposed inside a sealing layer.

[0007] The present invention has been made to solve the above problems, and has an object to provide a capacitor element that can suppress peeling in the capacitively effective portion. [Means for solving the problem]

[0008] The capacitor element of the present invention comprises a capacitor section including an anode plate having a porous section on at least one main surface of a core section, a dielectric layer provided on the surface of the porous section, and a cathode layer provided on the surface of the dielectric layer, and a sealing layer that seals the capacitor section, and an insulating layer having a lower Young's modulus than the sealing layer is provided inside the sealing layer in a position not in contact with the cathode layer. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a capacitor element that can suppress peeling in the capacitively effective portion. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of a capacitor element according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the capacitor element shown in FIG. 1 taken along line A. FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an example of a capacitor element according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an example of a capacitor element according to a third embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view schematically showing an example of a capacitor element according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The capacitor element of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0012] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0013] In the following description, when no particular distinction is made between the embodiments, they will simply be referred to as "the capacitor element of the present invention."

[0014] In this specification, terms indicating the relationship between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms indicating the shape of elements are not expressions that only express a strict meaning, but are expressions that also include a range of substantial equivalence, for example, a difference of a few percent.

[0015] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0016] [First embodiment] Fig. 1 is a cross-sectional view schematically showing an example of a capacitor element according to a first embodiment of the present invention, Fig. 2 is a plan view taken along line A of the capacitor element shown in Fig. 1.

[0017] The capacitor element 1 shown in FIGS. 1 and 2 includes a capacitor section 10 and a sealing layer 30 that seals the capacitor section 10.

[0018] 1 and 2, two capacitor sections 10 are arranged inside sealing layer 30. The number of capacitor sections 10 arranged inside sealing layer 30 is not particularly limited, and may be one or more.

[0019] The capacitor section 10 includes an anode plate 11 having a porous portion 11B on at least one main surface of a core portion 11A, a dielectric layer 13 provided on the surface of the porous portion 11B, and a cathode layer 12 provided on the surface of the dielectric layer 13. This makes up an electrolytic capacitor. In the example shown in FIG. 1, the anode plate 11 has the porous portion 11B on both main surfaces of the core portion 11A, but the porous portion 11B may be provided on only one of the main surfaces of the core portion 11A.

[0020] Cathode layer 12 includes, for example, solid electrolyte layer 12A provided on the surface of dielectric layer 13. Cathode layer 12 preferably further includes conductor layer 12B provided on the surface of solid electrolyte layer 12A. When cathode layer 12 includes solid electrolyte layer 12A, capacitor section 10 constitutes a solid electrolytic capacitor.

[0021] 1, sealing layer 30 is preferably provided on both opposing main surfaces in the thickness direction of capacitor section 10. Capacitor section 10 is protected by sealing layer 30.

[0022] Sealing layer 30 is formed so as to seal capacitor section 10 by, for example, a method of thermocompressing an insulating resin sheet, or a method of applying an insulating resin paste and then thermally curing it.

[0023] An insulating layer 40 having a lower Young's modulus than the sealing layer 30 is provided inside the sealing layer 30 at a position not in contact with the cathode layer 12 .

[0024] By providing the insulating layer 40, which is softer than the sealing layer 30, inside the sealing layer 30, stress caused by warping or the like can be alleviated. Furthermore, by providing the insulating layer 40 at a position not in contact with the cathode layer 12, even if delamination occurs, it can be made to occur preferentially near the insulating layer 40 rather than near the cathode layer 12. Therefore, peeling in the capacitively effective portion can be suppressed. As a result, deterioration of the equivalent series resistance (ESR) can be reduced.

[0025] When the cathode layer 12 includes a solid electrolyte layer 12A and a conductor layer 12B, the insulating layer 40 is preferably provided at a position that does not contact the conductor layer 12B.

[0026] The capacitor element 1 may further include an external electrode layer 50 provided on the surface of the sealing layer 30 .

[0027] The external electrode layer 50 includes, for example, a first external electrode layer 51 electrically connected to the anode plate 11 and a second external electrode layer 52 electrically connected to the cathode layer 12 .

[0028] Capacitor element 1 may further include a lead conductor that is provided inside sealing layer 30 and led out to the surface of sealing layer 30.

[0029] Examples of the lead conductor include a through-hole conductor 70 and a via conductor 90.

[0030] The lead conductors include, for example, a first lead conductor electrically connected to the anode plate 11 and a second lead conductor electrically connected to the cathode layer 12.

[0031] An example of the first lead conductor is a first through-hole conductor 71. One first through-hole conductor 71 may be provided inside the cathode layer 12, or two or more first through-hole conductors 71 may be provided inside the cathode layer 12.

[0032] Examples of the second lead conductor include a second through-hole conductor 72 and a via conductor 90. One second through-hole conductor 72 may be provided inside the cathode layer 12, or two or more second through-hole conductors 72 may be provided inside the cathode layer 12. Furthermore, one via conductor 90 may be provided inside the cathode layer 12, or two or more via conductors 90 may be provided inside the cathode layer 12.

[0033] 1, the capacitor element 1 includes a first through-hole conductor 71 as the first lead conductor. In this case, the insulating layer 40 is preferably provided at a position that does not contact the cathode layer 12 and the first through-hole conductor 71. By providing the insulating layer 40 at a position that does not contact the first lead conductor, such as the first through-hole conductor 71, peeling of the first lead conductor can be suppressed. As a result, deterioration of the ESR can be reduced.

[0034] 1, the capacitor element 1 further includes a first external electrode layer 51. In this case, the insulating layer 40 is preferably provided at a position that does not contact the cathode layer 12, the first through-hole conductor 71, or the first external electrode layer 51. By providing the insulating layer 40 at a position that does not contact the first external electrode layer 51, peeling at the first external electrode layer 51 can be suppressed. As a result, deterioration of the ESR can be reduced.

[0035] 1, the capacitor element 1 includes a second through-hole conductor 72 and a via conductor 90 as the second extraction conductor. In this case, the insulating layer 40 is preferably provided at a position that does not contact the cathode layer 12, the second through-hole conductor 72, or the via conductor 90. By providing the insulating layer 40 at a position that does not contact the second extraction conductors such as the second through-hole conductor 72 and the via conductor 90, peeling of the second extraction conductor can be suppressed. As a result, deterioration of the ESR can be reduced.

[0036] 1, the capacitor element 1 further includes a second external electrode layer 52. In this case, the insulating layer 40 is preferably provided at a position that does not contact the cathode layer 12, the second through-hole conductor 72, the via conductor 90, or the second external electrode layer 52. By providing the insulating layer 40 at a position that does not contact the second external electrode layer 52, peeling at the second external electrode layer 52 can be suppressed. As a result, deterioration of the ESR can be reduced.

[0037] In addition, when the insulating layer 40 is located at a position that does not contact the second extraction conductor, the insulating layer 40 may be located at a position that does not contact both the second through-hole conductor 72 and the via conductor 90, or may be located at a position that does not contact only one of the second through-hole conductor 72 and the via conductor 90.

[0038] In plan view from the thickness direction of the cathode layer 12, the insulating layer 40 may be provided on at least a part of the capacitor element 1, but is preferably provided over the entire capacitor element 1.

[0039] In a plan view from the thickness direction of the cathode layer 12, the insulating layer 40 preferably covers 20% or more of the area of ​​the cathode layer 12, more preferably covers 50% or more of the area, and even more preferably covers 80% or more of the area of ​​the cathode layer 12. On the other hand, in a plan view from the thickness direction of the cathode layer 12, the insulating layer 40 may cover 100% of the area of ​​the cathode layer 12, or may cover 80% or less of the area of ​​the cathode layer 12.

[0040] In a plan view from the thickness direction of the cathode layer 12, the insulating layer 40 may be provided at a position overlapping with the cathode layer 12, at a position not overlapping with the cathode layer 12, or at both a position overlapping with the cathode layer 12 and a position not overlapping with the cathode layer 12.

[0041] It is preferable that insulating layer 40 covers the midpoints of at least one pair of adjacent lead conductors in a plan view from the thickness direction of cathode layer 12. For example, it is preferable that insulating layer 40 covers the midpoint between first through-hole conductor 71 and second through-hole conductor 72, the midpoint between first through-hole conductor 71 and via conductor 90, the midpoint between second through-hole conductor 72 and via conductor 90, the midpoint between first through-hole conductor 71 and first through-hole conductor 71, the midpoint between second through-hole conductor 72 and second through-hole conductor 72, the midpoint between via conductors 90, etc.

[0042] The insulating layer 40 is preferably provided in parallel to the capacitor section 10. Specifically, the insulating layer 40 is preferably provided in parallel to at least one of the main surfaces of the capacitor section 10.

[0043] When sealing layers 30 are provided on both main surfaces of the capacitor unit 10, the insulating layer 40 may be provided inside the sealing layer 30 on either one of the main surfaces of the capacitor unit 10, or may be provided inside the sealing layer 30 on both main surfaces of the capacitor unit 10. When insulating layers 40 are provided inside the sealing layer 30 on both main surfaces of the capacitor unit 10, the insulating layer 40 provided inside the sealing layer 30 on one main surface of the capacitor unit 10 may or may not overlap partly or entirely in the thickness direction with the insulating layer 40 provided inside the sealing layer 30 on the other main surface of the capacitor unit 10.

[0044] The method for forming the insulating layer 40 inside the sealing layer 30 is not particularly limited, and examples thereof include a method in which a first insulating resin sheet constituting the sealing layer 30 is thermocompressed, an insulating resin constituting the insulating layer 40 is disposed, and a second insulating resin sheet constituting the sealing layer 30 is further thermocompressed; or a method in which a first insulating resin paste constituting the sealing layer 30 is applied and thermally cured, an insulating resin constituting the insulating layer 40 is disposed, and a second insulating resin paste constituting the sealing layer 30 is applied and thermally cured. The material of the first insulating resin sheet or the first insulating resin paste may be the same as or different from the material of the second insulating resin sheet or the second insulating resin paste.

[0045] The term "Young's modulus" as used herein refers to a value measured in accordance with JIS R 1602: 1995. For example, the Young's modulus may be a value obtained by measurement using a bench-top precision universal testing machine (manufactured by Shimadzu Corporation, model number AGS-5kNX).

[0046] The Young's modulus of the insulating layer 40 is not particularly limited as long as it is lower than the Young's modulus of the sealing layer 30. The Young's modulus of the sealing layer 30 is, for example, 5 GPa or more and 40 GPa or less.

[0047] The thickness of one insulating layer 40 is not particularly limited, but is preferably 80% or less of the thickness of one side of sealing layer 30 (the distance from the surface of sealing layer 30 to the surface of cathode layer 12).

[0048] The insulating layer 40 is made of, for example, an insulating resin. The type of insulating resin that makes up the insulating layer 40 may be the same as the type of insulating resin that makes up the sealing layer 30, or may be different.

[0049] [Second embodiment] In the capacitor element according to the second embodiment of the present invention, the insulating layer is made of a silicone resin or a fluororesin, or alternatively, the insulating layer is made of a resin containing a foaming agent.

[0050] FIG. 3 is a cross-sectional view schematically showing an example of a capacitor element according to a second embodiment of the present invention.

[0051] In capacitor element 2 shown in FIG. 3, insulating layer 40A having a lower Young's modulus than sealing layer 30 is provided inside sealing layer 30 at a position not in contact with cathode layer 12. Insulating layer 40A has a lower Young's modulus than sealing layer 30.

[0052] The insulating layer 40A is made of silicone resin or fluororesin. Silicone resin or fluororesin has a low Young's modulus and low adhesiveness, which makes it easier to obtain the effects described in the first embodiment.

[0053] Alternatively, the insulating layer 40A may be made of a resin containing a foaming agent. The resin containing a foaming agent also has a low Young's modulus and low adhesiveness. Therefore, the effects described in the first embodiment can be more easily achieved.

[0054] The Young's modulus of the insulating layer 40A is not particularly limited as long as it is lower than the Young's modulus of the sealing layer 30. The Young's modulus of the sealing layer 30 is, for example, not less than 5 GPa and not more than 40 GPa.

[0055] The thickness of one insulating layer 40A is not particularly limited, but is preferably 80% or less of the thickness of one side of sealing layer 30 (the distance from the surface of sealing layer 30 to the surface of cathode layer 12).

[0056] [Third embodiment] In the capacitor element according to the third embodiment of the present invention, the insulating layer is provided in a part of the capacitor element when viewed from above in the thickness direction of the cathode layer.

[0057] FIG. 4 is a cross-sectional view schematically showing an example of a capacitor element according to a third embodiment of the present invention.

[0058] 4, in a plan view from the thickness direction of the cathode layer 12, the insulating layer 40 is provided on a part of the capacitor element 3. Instead of the insulating layer 40, an insulating layer 40A may be provided.

[0059] As shown in Fig. 4, the insulating layer 40 may be selectively provided. For example, by providing the insulating layer 40 only in areas where stress is concentrated, it is possible to suppress the occurrence of delamination.

[0060] Alternatively, by locating the insulating layer 40 in the center of the surface when viewed in a plan view from the thickness direction of the cathode layer 12, delamination can be suppressed even when the internal pressure inside the capacitor element 3 increases due to gas generated from the material in a high-temperature atmosphere, causing the capacitor element 3 to bulge convexly.

[0061] As described in the first embodiment, it is preferable that the insulating layer 40 cover the midpoints of at least one pair of adjacent lead conductors in a plan view from the thickness direction of the cathode layer 12. For example, it is preferable that the insulating layer 40 cover the midpoint between the first through-hole conductor 71 and the second through-hole conductor 72, the midpoint between the first through-hole conductor 71 and the via conductor 90, the midpoint between the second through-hole conductor 72 and the via conductor 90, the midpoint between the first through-hole conductor 71 and the first through-hole conductor 71, the midpoint between the second through-hole conductor 72 and the second through-hole conductor 72, and the midpoint between the via conductors 90 and the via conductors 90, etc. in a plan view from the thickness direction of the cathode layer 12.

[0062] [Fourth embodiment] In the capacitor element according to the fourth embodiment of the present invention, two or more insulating layers are provided in the thickness direction.

[0063] FIG. 5 is a cross-sectional view schematically showing an example of a capacitor element according to a fourth embodiment of the present invention.

[0064] In the capacitor element 4 shown in Fig. 5, two insulating layers 40 are provided in the thickness direction. In Fig. 5, three or more insulating layers 40 may be provided in the thickness direction. In place of the insulating layer 40, an insulating layer 40A may be provided. Furthermore, the insulating layer 40 and the insulating layer 40A may be mixed.

[0065] By providing two or more insulating layers 40 in the thickness direction, stress can be prevented from concentrating in one place.

[0066] 5, two insulating layers 40 are provided inside the sealing layer 30 on one main surface side of the capacitor section 10, and two insulating layers 40 are provided inside the sealing layer 30 on the other main surface side of the capacitor section 10, but it is sufficient if two or more insulating layers 40 are provided inside the sealing layer 30 on at least one main surface side. Note that the insulating layers 40 may or may not overlap partly or entirely in the thickness direction.

[0067] The detailed configurations of capacitor elements 1, 2, 3 and 4 will be described below.

[0068] Examples of the planar shape of capacitor section 10 when viewed in the thickness direction include a rectangle (square or oblong), a quadrangle other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, an ellipse, a combination of these, etc. Furthermore, the planar shape of capacitor section 10 may be an L-shape, a C-shape, a stepped shape, etc.

[0069] The anode plate 11 is preferably made of a valve metal that exhibits so-called valve action. Examples of the valve metal include simple metals such as aluminum, tantalum, niobium, titanium, and zirconium, as well as alloys containing at least one of these metals. Among these, aluminum or an aluminum alloy is preferred.

[0070] The shape of the anode plate 11 is preferably a flat plate, and more preferably a foil. Thus, in this specification, the term "plate-like" includes "foil-like".

[0071] The anode plate 11 only needs to have the porous portion 11B on at least one main surface of the core portion 11A. That is, the anode plate 11 may have the porous portion 11B on only one main surface of the core portion 11A, or may have the porous portion 11B on both main surfaces of the core portion 11A. The porous portion 11B is preferably a porous layer formed on the surface of the core portion 11A, and more preferably an etched layer.

[0072] The thickness of the anode plate 11 before etching is preferably 60 μm or more and 200 μm or less. The thickness of the unetched core portion 11A after etching is preferably 15 μm or more and 70 μm or less. The thickness of the porous portion 11B is designed according to the required withstand voltage and capacitance, but the combined thickness of the porous portions 11B on both sides of the core portion 11A is preferably 10 μm or more and 180 μm or less.

[0073] The pore diameter of the porous portion 11B is preferably 10 nm or more and 600 nm or less. The pore diameter of the porous portion 11B means the median diameter D50 measured by a mercury porosimeter. The pore diameter of the porous portion 11B can be controlled, for example, by adjusting various etching conditions.

[0074] The dielectric layer 13 provided on the surface of the porous portion 11B is porous, reflecting the surface condition of the porous portion 11B, and has a finely uneven surface shape. The dielectric layer 13 is preferably made of an oxide film of the valve metal. For example, when an aluminum foil is used as the anode plate 11, the dielectric layer 13 made of an oxide film can be formed by anodizing the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like (also called chemical conversion treatment).

[0075] The thickness of the dielectric layer 13 is designed according to the required withstand voltage and capacitance, but is preferably 10 nm or more and 100 nm or less.

[0076] When the cathode layer 12 includes a solid electrolyte layer 12A, examples of materials constituting the solid electrolyte layer 12A include conductive polymers such as polypyrroles, polythiophenes, and polyanilines. Among these, polythiophenes are preferred, and poly(3,4-ethylenedioxythiophene), also known as PEDOT, is particularly preferred. The conductive polymer may also contain a dopant such as polystyrene sulfonate (PSS). The solid electrolyte layer 12A preferably includes an inner layer that fills the pores (recesses) of the dielectric layer 13 and an outer layer that covers the dielectric layer 13.

[0077] The thickness of the solid electrolyte layer 12A from the surface of the porous portion 11B is preferably 2 μm or more and 20 μm or less.

[0078] The solid electrolyte layer 12A is formed, for example, by a method of forming a polymer film of poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 13 using a treatment liquid containing a monomer such as 3,4-ethylenedioxythiophene, or by a method of applying a dispersion liquid of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer 13 and drying it.

[0079] The solid electrolyte layer 12A can be formed in a predetermined region by applying the above-mentioned treatment liquid or dispersion liquid to the surface of the dielectric layer 13 by a method such as sponge transfer, screen printing, dispenser application, or inkjet printing.

[0080] When the cathode layer 12 includes the conductor layer 12B, the conductor layer 12B includes at least one layer selected from a conductive resin layer and a metal layer. The conductor layer 12B may be composed of only a conductive resin layer or only a metal layer. The conductor layer 12B preferably covers the entire surface of the solid electrolyte layer 12A.

[0081] The conductive resin layer may be, for example, a conductive adhesive layer containing at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler.

[0082] Examples of the metal layer include a metal plating film and a metal foil. The metal layer is preferably made of at least one metal selected from the group consisting of nickel, copper, silver, and alloys containing these metals as the main component. The term "main component" refers to the elemental component with the largest weight ratio.

[0083] The conductor layer 12B includes, for example, a carbon layer provided on the surface of the solid electrolyte layer 12A and a copper layer provided on the surface of the carbon layer.

[0084] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer 12A and the copper layer. The carbon layer can be formed in a predetermined area by applying a carbon paste to the surface of the solid electrolyte layer 12A by sponge transfer, screen printing, dispenser application, inkjet printing, or other methods. Note that the carbon layer is preferably laminated with the copper layer in the next step while it is still viscous before drying. The thickness of the carbon layer is preferably 2 μm or more and 20 μm or less.

[0085] The copper layer can be formed in a predetermined area by applying a copper paste to the surface of the carbon layer by 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.

[0086] The sealing layer 30 is made of an insulating material, and in this case, the sealing layer 30 is preferably made of an insulating resin.

[0087] Examples of insulating resins that form the sealing layer 30 include epoxy resins and phenolic resins.

[0088] Preferably, the sealing layer 30 further contains a filler.

[0089] Examples of the filler contained in the sealing layer 30 include inorganic fillers such as silica particles and alumina particles.

[0090] Between the capacitor section 10 and the sealing layer 30, a layer other than the insulating layer 40, such as a moisture-proof film, may be provided.

[0091] The through-hole conductor 70 preferably includes at least one of a first through-hole conductor 71 electrically connected to the anode plate 11 and a second through-hole conductor 72 electrically connected to the cathode layer 12 .

[0092] The first through-hole conductor 71 penetrates the capacitor section 10 and the sealing layer 30 in the thickness direction.

[0093] The first through-hole conductor 71 may be provided on at least the inner wall surface of the first through hole 81 that penetrates the capacitor section 10 and the sealing layer 30 in the thickness direction. The first through-hole conductor 71 may be provided only on the inner wall surface of the first through hole 81, or may be provided throughout the entire interior of the first through hole 81.

[0094] The first through-hole conductor 71 is preferably electrically connected to the anode plate 11 on the inner wall surface of the first through hole 81. More specifically, the first through-hole conductor 71 is preferably electrically connected to the end surface of the anode plate 11 that faces the inner wall surface of the first through hole 81 in the planar direction. This allows the anode plate 11 to be electrically led out to the outside via the first through-hole conductor 71.

[0095] It is preferable that the core portion 11A and the porous portion 11B are exposed on the end surface of the anode plate 11 that is electrically connected to the first through-hole conductor 71. In this case, the porous portion 11B as well as the core portion 11A are electrically connected to the first through-hole conductor 71.

[0096] When viewed in the thickness direction, it is preferable that the first through-hole conductor 71 is electrically connected to the anode plate 11 around the entire periphery of the first through hole 81. In this case, the connection resistance between the anode plate 11 and the first through-hole conductor 71 is likely to decrease, and therefore the ESR is likely to decrease.

[0097] The first through-hole conductors 71 are formed, for example, as follows. First, first through holes 81 are formed by drilling, laser processing, or the like, penetrating the capacitor section 10 and the sealing layer 30 in the thickness direction. Then, the inner wall surfaces of the first through holes 81 are metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the first through-hole conductors 71. When forming the first through-hole conductors 71, for example, metallizing the inner wall surfaces of the first through holes 81 with electroless copper plating, electrolytic copper plating, or the like makes processing easier. Note that the first through-hole conductors 71 may be formed by filling the first through holes 81 with a metal material, a composite material of metal and resin, or the like, in addition to metallizing the inner wall surfaces of the first through holes 81.

[0098] An anode connection layer may be provided in the planar direction between the anode plate 11 and the first through-hole conductor 71. That is, the anode plate 11 and the first through-hole conductor 71 may be electrically connected via the anode connection layer.

[0099] The anode connection layer is provided between the anode plate 11 and the first through-hole conductor 71 in the surface direction, and therefore functions as a barrier layer for the anode plate 11, more specifically, as a barrier layer for the core portion 11A and the porous portion 11B. When the anode connection layer functions as a barrier layer for the anode plate 11, dissolution of the anode plate 11 that occurs during chemical treatment to form the external electrode layer 50 (e.g., the first external electrode layer 51) is suppressed, and therefore penetration of the chemical solution into the capacitor portion 10 is suppressed, which tends to improve reliability.

[0100] The anode connecting layer preferably includes a layer containing nickel as a main component, which reduces damage to the metal (e.g., aluminum) constituting the anode plate 11, and therefore improves the barrier properties of the anode connecting layer against the anode plate 11.

[0101] In addition, in the surface direction, an anode connecting layer does not have to be provided between the anode plate 11 and the first through-hole conductor 71. In this case, the first through-hole conductor 71 may be directly connected to the end surface of the anode plate 11.

[0102] When first through-hole conductor 71 is provided only on the inner wall surface of first through hole 81, first through hole 81 may be provided with a resin-filled portion filled with a resin material. In this case, the resin-filled portion is provided in the space surrounded by first through-hole conductor 71 inside first through hole 81. When the space inside first through hole 81 is eliminated by providing the resin-filled portion, delamination of first through-hole conductor 71 is suppressed.

[0103] The first external electrode layer 51 is electrically connected to the anode plate 11. In the example shown in Fig. 1, the first external electrode layer 51 is provided on the surface of the first through-hole conductor 71, and functions as a connection terminal for the capacitor section 10. In the example shown in Fig. 1, the first external electrode layer 51 is electrically connected to the anode plate 11 via the first through-hole conductor 71, and functions as a connection terminal for the anode plate 11.

[0104] Examples of materials constituting the first external electrode layer 51 include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the first external electrode layer 51 is formed by, for example, plating the surfaces of the first through-hole conductors 71.

[0105] In order to improve the adhesion between the first external electrode layer 51 and other components, in this case, the adhesion between the first external electrode layer 51 and the first through-hole conductor 71, 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 may be used as the constituent material of the first external electrode layer 51.

[0106] The second through-hole conductor 72 penetrates the capacitor section 10 and the sealing layer 30 in the thickness direction.

[0107] The second through-hole conductor 72 may be provided on at least the inner wall surface of the second through hole 82 that penetrates the capacitor section 10 and the sealing layer 30 in the thickness direction. The second through-hole conductor 72 may be provided only on the inner wall surface of the second through hole 82, or may be provided throughout the entire interior of the second through hole 82.

[0108] The second through-hole conductor 72 is formed, for example, as follows. First, a through-hole penetrating the capacitor section 10 in the thickness direction is formed by drilling, laser processing, or the like. Next, an insulating material is filled into the through-hole. The portion filled with the insulating material is then drilled, laser processing, or the like to form the second through-hole 82. At this time, the diameter of the second through-hole 82 is made smaller than the diameter of the through-hole filled with the insulating material, so that the insulating material is present between the inner wall surface of the previously formed through-hole and the inner wall surface of the second through-hole 82 in the planar direction. Then, the inner wall surface of the second through-hole 82 is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the second through-hole conductor 72. When forming the second through-hole conductor 72, for example, metallizing the inner wall surface of the second through-hole 82 by electroless copper plating, electrolytic copper plating, or the like can facilitate processing. As for the method of forming the second through-hole conductor 72, in addition to the method of metallizing the inner wall surface of the second through hole 82, a method of filling the second through hole 82 with a metal material, a composite material of metal and resin, etc. may also be used.

[0109] When the second through-hole conductor 72 is provided only on the inner wall surface of the second through hole 82, a resin-filled portion filled with a resin material may be provided in the second through hole 82. In this case, the resin-filled portion is provided in the space surrounded by the second through-hole conductor 72 inside the second through hole 82. When the space inside the second through hole 82 is eliminated by providing the resin-filled portion, the occurrence of delamination of the second through-hole conductor 72 is suppressed.

[0110] The second external electrode layer 52 is electrically connected to the cathode layer 12. In the example shown in Figure 1, the second external electrode layer 52 is provided on the surface of the second through-hole conductor 72, and functions as a connection terminal of the capacitor section 10.

[0111] Examples of materials constituting the second external electrode layer 52 include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the second external electrode layer 52 is formed by, for example, plating the surfaces of the second through-hole conductors 72.

[0112] In order to improve the adhesion between the second external electrode layer 52 and other components, in this case, the adhesion between the second external electrode layer 52 and the second through-hole conductor 72, 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 may be used as the constituent material of the second external electrode layer 52.

[0113] The constituent materials of the first external electrode layer 51 and the second external electrode layer 52 are preferably the same at least in terms of type, but may be different from each other.

[0114] In the example shown in FIG. 1, each of the plurality of capacitor sections 10 is provided with a first external electrode layer 51 electrically connected to the anode plate 11 and a second external electrode layer 52 electrically connected to the cathode layer 12, but at least one of the first external electrode layer 51 and the second external electrode layer 52 may be provided in common among the plurality of capacitor sections 10.

[0115] In the example shown in FIG. 1, the first external electrode layer 51 and the second external electrode layer 52 are provided on both main surfaces of the sealing layer 30, but they may also be provided on only one main surface of the sealing layer 30.

[0116] Although not shown in FIG. 1, the through-hole conductors 70 may include a third through-hole conductor that is not electrically connected to the anode plate 11 and the cathode layer 12 .

[0117] The via conductor 90 penetrates the sealing layer 30 in the thickness direction and is connected to the cathode layer 12 and the second external electrode layer 52 .

[0118] Examples of materials that can be used to form the via conductors 90 include metal materials containing low-resistance metals such as silver, gold, and copper.

[0119] The via conductor 90 is formed, for example, by plating the inner wall surface of a through hole that penetrates the sealing layer 30 in the thickness direction with the above-mentioned metal material, or by filling it with a conductive paste and then performing a heat treatment.

[0120] In the example shown in FIG. 1, the second through-hole conductor 72 is electrically connected to the cathode layer 12 via the second external electrode layer 52 and the via conductor 90 .

[0121] In the example shown in FIG. 1, the second external electrode layer 52 is electrically connected to the cathode layer 12 through a via conductor 90 and functions as a connection terminal for the cathode layer 12.

[0122] When the through-hole conductor 70 is provided inside the sealing layer 30 , the capacitor section 10 preferably further includes a mask layer 35 provided around the through-hole conductor 70 on at least one main surface of the anode plate 11 .

[0123] 1 and 2, a mask layer 35 is provided between the first through-hole conductor 71 and the cathode layer 12. In addition, in the example shown in Figures 1 and 2, an insulating material such as a sealing layer 30 is filled between the second through-hole conductor 72 and the capacitor section 10, and a mask layer 35 is provided between this insulating material and the cathode layer 12.

[0124] 1 and 2, the capacitor section 10 may further include a mask layer provided on at least one main surface of the anode plate 11 so as to surround the periphery of the cathode layer 12. By surrounding the periphery of the cathode layer 12 with the mask layer, insulation between the anode plate 11 and the cathode layer 12 is ensured, and short-circuiting between them is prevented. The mask layer may be provided so as to surround a portion of the periphery of the cathode layer 12, but is preferably provided so as to surround the entire periphery of the cathode layer 12.

[0125] The mask layers such as the mask layer 35 are made of an insulating material, and in this case, the mask layers are preferably made of an insulating resin.

[0126] Examples of insulating resins that may be used to form mask layers such as the mask layer 35 include polyphenylsulfone resin, polyethersulfone resin, cyanate ester resin, fluororesin (such as tetrafluoroethylene and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), polyimide resin, polyamideimide resin, epoxy resin, and derivatives or precursors thereof.

[0127] The mask layers such as mask layer 35 may be made of the same resin as sealing layer 30. Unlike sealing layer 30, if the mask layer contains an inorganic filler, it may adversely affect the effective capacitance portion of capacitor section 10. Therefore, it is preferable that the mask layer be made of a resin alone.

[0128] A mask layer such as mask layer 35 can be formed in a predetermined area by applying a mask material such as a composition containing an insulating resin to the surface of porous portion 11B by a method such as sponge transfer, screen printing, dispenser application, or inkjet printing.

[0129] The mask layer such as the mask layer 35 may be formed on the porous portion 11B either before or after the dielectric layer 13 is formed.

[0130] [Other embodiments] The capacitor element of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration of the capacitor element, manufacturing conditions, and the like.

[0131] In the capacitor element of the present invention, one capacitor portion may be disposed inside the sealing layer, or a plurality of capacitor portions may be disposed inside the sealing layer.

[0132] In the capacitor element of the present invention, when multiple capacitor units are disposed inside the sealing layer, adjacent capacitor units only need to be physically separated. Therefore, adjacent capacitor units may be electrically separated or electrically connected. The portion where adjacent capacitor units are separated is preferably filled with an insulating material such as a sealing layer. The distance between adjacent capacitor units may be constant in the thickness direction or may decrease in the thickness direction.

[0133] In the capacitor element of the present invention, when multiple capacitor sections are arranged inside the sealing layer, the multiple capacitor sections may be arranged so as to be lined up in the surface direction, so as to be stacked in the thickness direction, or a combination of both. The multiple capacitor sections may be arranged regularly or irregularly. The size, shape, etc. of the capacitor elements may be the same, or some or all of them may be different. The capacitor elements preferably have the same configuration, but capacitor elements with different configurations may be included.

[0134] The capacitor element of the present invention can be suitably used as a constituent material of a composite electronic component. Such a composite electronic component includes, for example, the capacitor element of the present invention, external electrode layers provided on the surface of the sealing layer of the capacitor element and electrically connected to the anode plate and cathode layer of the capacitor element, respectively, and an electronic component connected to the external electrode layers.

[0135] In a composite electronic component, the electronic component connected to the external electrode layer may be a passive element or an active element. Both a passive element and an active element may be connected to the external electrode layer, or either a passive element or an active element may be connected to the external electrode layer. Also, a composite of a passive element and an active element may be connected to the external electrode layer.

[0136] Examples of passive elements include inductors, etc. Examples of active elements include memories, GPUs (Graphical Processing Units), CPUs (Central Processing Units), MPUs (Micro Processing Units), and PMICs (Power Management ICs).

[0137] The capacitor element of the present invention has a sheet-like shape as a whole. Therefore, in a composite electronic component, the capacitor element can be treated like a mounting substrate, and electronic components can be mounted on the capacitor element. Furthermore, by making the electronic components mounted on the capacitor element sheet-like, it is also possible to connect the capacitor element and the electronic components in the thickness direction via through-hole conductors that penetrate each electronic component in the thickness direction. As a result, active elements and passive elements can be configured like a single module.

[0138] For example, a switching regulator can be formed by electrically connecting the capacitor element of the present invention between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied.

[0139] In a composite electronic component, a circuit layer may be formed on either side of a capacitor matrix sheet on which a plurality of capacitor elements of the present invention are laid out, and the circuit layer may be connected to a passive element or an active element.

[0140] Alternatively, the capacitor element of the present invention may be placed in a cavity provided in a substrate, embedded in resin, and then a circuit layer may be formed on the resin. Another electronic component (a passive element or an active element) may be mounted in another cavity of the same substrate.

[0141] Alternatively, the capacitor element of the present invention may be mounted on a smooth carrier such as a wafer or glass, an outer layer made of resin may be formed, a circuit layer may be formed, and then the capacitor element may be connected to a passive or active element.

[0142] The present specification discloses the following:

[0143] <1> a capacitor section including an anode plate having a porous portion on at least one main surface of a core portion, a dielectric layer provided on the surface of the porous portion, and a cathode layer provided on the surface of the dielectric layer; a sealing layer that seals the capacitor portion, a capacitor element, wherein an insulating layer having a lower Young's modulus than the sealing layer is provided inside the sealing layer at a position not in contact with the cathode layer;

[0144] <2> a first lead conductor provided inside the sealing layer so as to be electrically connected to the anode plate and led out to a surface of the sealing layer; the insulating layer is provided at a position not in contact with the cathode layer and the first extraction conductor. <1> The capacitor element according to claim 1.

[0145] <3> a first external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the anode plate via the first lead conductor; the insulating layer is provided at a position not in contact with the cathode layer, the first lead conductor, and the first external electrode layer; <2> The capacitor element according to claim 1.

[0146] <4> a second lead conductor provided inside the sealing layer so as to be electrically connected to the cathode layer and led out to a surface of the sealing layer; the insulating layer is provided at a position not in contact with the cathode layer and the second lead conductor. <1> ~ <3> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together.

[0147] <5> a second external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the cathode layer via the second lead conductor; the insulating layer is provided at a position not in contact with the cathode layer, the second lead conductor, and the second external electrode layer. <4> The capacitor element according to claim 1.

[0148] <6> The insulating layer is made of a silicone resin or a fluororesin. <1> ~ <5> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together.

[0149] <7> The insulating layer is made of a resin containing a foaming agent. <1> ~ <6> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together.

[0150] <8> the insulating layer covers 20% or more of an area of ​​the cathode layer in a plan view in a thickness direction of the cathode layer. <1> ~ <7> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together.

[0151] <9> The insulating layer is provided in two or more layers in the thickness direction. <1> ~ <8> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together.

[0152] <10> the cathode layer includes a solid electrolyte layer provided on a surface of the dielectric layer; <1> ~ <9> 10. The capacitor element according to claim 9, wherein the first and second capacitor elements are fused together. [Explanation of symbols]

[0153] 1, 2, 3, 4 Capacitor elements 10 Capacitor section 11 Anode plate 11A core 11B Porous part 12 Cathode layer 12A solid electrolyte layer 12B Conductive layer 13 Dielectric layer 30 Sealing layer 35 Mask Layer 40, 40A insulation layer 50 External electrode layer 51 1st external electrode layer 52 Second external electrode layer 70 through-hole conductor 71 First through-hole conductor 72 Second through-hole conductor 81 First through hole 82 Second through hole 90 Via conductor

Claims

1. a capacitor section including an anode plate having a porous portion on at least one main surface of a core portion, a dielectric layer provided on the surface of the porous portion, and a cathode layer provided on the surface of the dielectric layer; a sealing layer that seals the capacitor portion, a capacitor element, wherein an insulating layer having a lower Young's modulus than the sealing layer is provided inside the sealing layer at a position not in contact with the cathode layer;

2. a first lead conductor provided inside the sealing layer so as to be electrically connected to the anode plate and led out to a surface of the sealing layer; The capacitor element according to claim 1 , wherein the insulating layer is provided at a position not in contact with the cathode layer and the first lead conductor.

3. a first external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the anode plate via the first lead conductor; The capacitor element according to claim 2 , wherein the insulating layer is provided at a position not in contact with the cathode layer, the first lead conductor, and the first external electrode layer.

4. a second lead conductor provided inside the sealing layer so as to be electrically connected to the cathode layer and led out to a surface of the sealing layer; 4. The capacitor element according to claim 1, wherein the insulating layer is provided at a position where it does not come into contact with the cathode layer and the second lead conductor.

5. a second external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the cathode layer via the second lead conductor; The capacitor element according to claim 4 , wherein the insulating layer is provided at a position not in contact with the cathode layer, the second lead conductor, and the second external electrode layer.

6. 4. The capacitor element according to claim 1, wherein the insulating layer is made of a silicone resin or a fluororesin.

7. 4. The capacitor element according to claim 1, wherein the insulating layer is made of a resin containing a foaming agent.

8. 4. The capacitor element according to claim 1, wherein, in a plan view from a thickness direction of the cathode layer, the insulating layer covers an area of ​​the cathode layer that is 20% or more of an area of ​​the cathode layer.

9. 4. The capacitor element according to claim 1, wherein the insulating layer comprises two or more layers provided in the thickness direction.

10. 4. The capacitor element according to claim 1, wherein the cathode layer includes a solid electrolyte layer provided on a surface of the dielectric layer.

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