Capacitor element

Abstract

A capacitor element (1) is provided with: an anode plate (10) having a porous layer (12) on at least one main surface; a dielectric layer (20) provided on the surface of the porous layer (12); a cathode layer (30) provided on the surface of the dielectric layer (20); and an insulating layer (40) which is provided on the surface of the dielectric layer (20) so as to partially overlap the cathode layer (30), and which satisfies d1 > = 0.2 * d2, where d1 is the layer thickness of a portion (34) where the cathode layer (30) overlaps the insulating layer (40) at an end (40a) of the insulating layer (40) that overlaps the cathode layer (30), and d2 is the layer thickness of the insulating layer.

Description

Technical Field

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

[0002] In Patent Document 1, a capacitor array is described. The capacitor array includes: a plurality of 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 formed of a valve action 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. The solid electrolytic capacitor sheet has a first main surface and a second main surface opposite to each other in the thickness direction. The first main surface sides of the plurality of solid electrolytic capacitor elements are disposed on the first sealing layer, and the second sealing layer is disposed so as to cover the plurality of solid electrolytic capacitor elements on the first sealing layer from the second main surface side. The solid electrolytic capacitor elements are separated from each other by slit-shaped sheet removal portions.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-167361 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] For example, in FIG. 27 of Patent Document 1, if there is a layer thickness difference between the conductive layer portion (cathode layer 24) and the insulating layer portion (stress relaxation layer 13, insulating layer 30) and their switching portions, there is a possibility that the pressure applied to each layer becomes uneven when a resin sheet is pasted to form a sealing layer, and the interfacial adhesion between the thinner layer, i.e., the switching portion, and the sealing layer is reduced. As a result, there is a possibility of occurrence of peeling called delamination, for example, peeling of the sealing layer.

[0008] The present invention has been completed to solve the above problems, and an object thereof is to provide a capacitor element capable of improving the interfacial adhesion between a sealing layer and its substrate and suppressing delamination.

[0009] Means for Solving the Problems

[0010] The capacitor element of the present invention includes: an anode plate having a porous layer on at least one main surface; a dielectric layer provided on the surface of the porous layer; a cathode layer provided on the surface of the dielectric layer; and an insulating layer provided on the surface of the dielectric layer so as to partially overlap with the cathode layer. When the layer thickness of the portion of the cathode layer overlapping with the insulating layer at the end of the insulating layer overlapping with the cathode layer is set as d1 and the layer thickness of the insulating layer is set as d2, d1≥0.2×d2 is satisfied.

[0011] Effect of the Invention

[0012] According to the present invention, it is possible to provide a capacitor element capable of improving the interfacial adhesion between the sealing layer and its substrate and suppressing delamination. Description of the Drawings

[0013] Figure 1 It is a cross-sectional schematic view showing an example of the capacitor element of Embodiment 1 of the present invention.

[0014] Figure 2 It is an enlarged view showing Figure 1 an example of the region surrounded by a dashed line of the capacitor element shown.

[0015] Figure 3 It is an enlarged view showing Figure 1 another example of the region surrounded by a dashed line of the capacitor element shown.

[0016] Figure 4 It is a top view schematic view showing an example of the capacitor array of Embodiment 2 of the present invention.

[0017] Figure 5 It is showing Figure 4 an example of a cross-sectional view along line A-A of the capacitor array shown.

[0018] Figure 6 It is showing Figure 4 an example of a cross-sectional view along line B-B of the capacitor array shown.

[0019] Figure 7 It is a top view schematic view showing an example of the capacitor array of Embodiment 3 of the present invention.

[0020] Figure 8 It is showing Figure 7 an example of a cross-sectional view along line A-A of the capacitor array shown.

[0021] Figure 9 It is showing Figure 7 an example of a cross-sectional view along line B-B of the capacitor array shown. Detailed implementation manners

[0022] Hereinafter, the capacitor element of the present invention will be described. In addition, the present invention is not limited to the following structures, and can also be appropriately changed within the scope of not changing the gist of the present invention. In addition, a structure formed by combining a plurality of each of the preferred structures described below is also the present invention.

[0023] It is self-evident that each of the following embodiments is an illustration, and partial replacement or combination of the structures shown in different embodiments can be performed. After the second embodiment, the description of matters common to the first embodiment will be omitted, and the different points will be mainly described. In particular, the same effects produced by the same structures will not be mentioned successively in each embodiment.

[0024] In the following description, without particularly distinguishing each embodiment, it is simply referred to as "the capacitor element of the present invention".

[0025] In this specification, terms indicating the relationality between elements (such as "vertical", "parallel", "orthogonal", etc.) and terms indicating the shape of elements are not expressions indicating only strict meanings, but also include expressions including substantially equivalent ranges, for example, differences of several percentage points.

[0026] The drawings shown below are schematic diagrams, and there are cases where their dimensions, aspect ratio scales, etc. are different from those of actual products.

[0027] [Embodiment 1]

[0028] Figure 1 It is a cross-sectional schematic diagram showing an example of the capacitor element of Embodiment 1 of the present invention.

[0029] Figure 1 The shown capacitor element 1 has an anode plate 10, a dielectric layer 20, a cathode layer 30, and an insulating layer 40.

[0030] The anode plate 10 has a core part 11 and a porous layer 12.

[0031] In this specification, "plate" also includes "sheet", "foil", "film", etc., and they are not distinguished according to thickness.

[0032] The core part 11 is formed of a metal, and preferably formed of a valve-acting metal. When the core part 11 is formed of a valve-acting metal, the anode plate 10 is also called a valve-acting metal substrate.

[0033] As the valve-acting metal, for example, metal monomers such as aluminum, tantalum, niobium, titanium, zirconium, and alloys containing at least one of these metal monomers can be cited. Among them, aluminum or an aluminum alloy is preferred.

[0034] The porous layer 12 is provided on at least one major surface of the core 11. That is to say, the porous layer 12 can be provided only on one major surface of the core 11, or can be provided on both major surfaces of the core 11 as shown in Figure 1 . In this way, the anode plate 10 has the porous layer 12 on at least one major surface. As a result, the surface area of the anode plate 10 becomes larger, and thus the capacitance of the capacitor element 1 is easily increased.

[0035] Preferably, the porous layer 12 is an etched layer formed by etching the surface of the anode plate 10.

[0036] The shape of the anode plate 10 is preferably flat, and more preferably foil-like. In this specification, "plate-like" also includes "foil-like". In addition, in this specification, "plate-like" also includes "sheet-like", "film-like", etc.

[0037] The dielectric layer 20 is provided on the surface of the porous layer 12. It is schematically shown in the drawings. More specifically, the dielectric layer 20 is provided along the surface (outline) of each pore existing in the porous layer 12.

[0038] Preferably, the dielectric layer 20 is composed of an oxide coating film of the above-mentioned valve-acting metal. For example, when the anode plate 10 is an aluminum foil, an oxide coating film that becomes the dielectric layer 20 is formed by anodizing the anode plate 10 (also called chemical conversion treatment) in an aqueous solution containing ammonium adipate, etc. Since the dielectric layer 20 is formed along the surface of the porous layer 12, pores (recesses) are provided in the dielectric layer 20.

[0039] The cathode layer 30 is provided on the surface of the dielectric layer 20. More specifically, the cathode layer 30 is provided in the region surrounded by the insulating layer 40 on the surface of the dielectric layer 20.

[0040] In Figure 1 , the cathode layer 30 includes a solid electrolyte layer 31 provided on the surface of the dielectric layer 20 and a conductor layer 32 provided on the surface of the solid electrolyte layer 31. When the cathode layer 30 includes the solid electrolyte layer 31, the capacitor element constitutes a solid electrolytic capacitor.

[0041] As a constituent material of the solid electrolyte layer 31, for example, conductive polymers such as polypyrrole-based, polythiophene-based, and polyaniline-based can be cited. Among them, polythiophene-based is preferred, and poly(3,4-ethylenedioxythiophene) (PEDOT) is particularly preferred. In addition, it may be that the conductive polymer contains a dopant such as polystyrene sulfonic acid (PSS).

[0042] The solid electrolyte layer 31 is formed in a predetermined area inside the dielectric layer 20 having pores, for example, by a method of coating a dispersion of a conductive polymer such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer 20 and drying it, or by a method of forming a polymer film such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer 20 using a treatment liquid containing a polymerizable monomer such as 3,4-ethylenedioxythiophene.

[0043] Preferably, the conductor layer 32 includes a metal layer containing a metal filler.

[0044] Preferably, the metal filler is at least one selected from the group consisting of a copper filler, a silver filler, and a nickel filler.

[0045] The metal layer may be, for example, a metal coating film, a metal foil, etc. In this case, preferably, the metal layer is formed of at least one metal selected from the group consisting of copper, silver, nickel, and an alloy mainly composed of at least one of these metals.

[0046] In this specification, the main component means the element component having the largest weight ratio.

[0047] Preferably, in addition to the metal layer, the conductor layer 32 further includes a conductive resin layer.

[0048] Examples of the conductive resin layer include a conductive adhesive layer containing at least one conductive filler selected from the group consisting of a copper filler, a silver filler, a nickel filler, and a carbon filler.

[0049] In addition, the conductor layer 32 may include only the metal layer, may include only the conductive resin layer, or may include both the metal layer and the conductive resin layer.

[0050] In Figure 1 In the example shown, the conductor layer 32 includes a first conductor layer 32A provided on the surface of the solid electrolyte layer 31 and a second conductor layer 32B provided on the surface of the first conductor layer 32A. Thus, preferably, the conductor layer 32 includes a plurality of conductor layers.

[0051] In the solid electrolytic capacitor, since the thickness of the dielectric layer is small, the leakage current tends to be a problem. In contrast, by including a plurality of conductor layers such as the first conductor layer 32A and the second conductor layer 32B in the conductor layer 32, there are a plurality of bulk resistances and interface resistances in the cathode layer 30, so that the leakage current is easily suppressed.

[0052] Preferably, the first conductor layer 32A is a conductive resin layer containing a conductive filler.

[0053] Preferably, the second conductor layer 32B is a metal layer containing a metal filler.

[0054] Alternatively, the conductive layer 32 may include, for example, a carbon layer as the first conductive layer 32A and a copper layer as the second conductive layer 32B.

[0055] The carbon layer is formed in a predetermined area, for example, by applying a carbon paste containing carbon fillers onto the surface of the solid electrolyte layer 31 using a sponge transfer method, a screen printing method, a dispenser coating method, an inkjet printing method, or the like.

[0056] The copper layer is formed in a predetermined area, for example, by applying a copper paste containing copper fillers onto the surface of the carbon layer using a sponge transfer method, a screen printing method, a spray coating method, a dispenser coating method, an inkjet printing method, or the like.

[0057] When viewed from the thickness direction, the planar shape of the outer peripheral edge of each layer of the cathode layer 30 is, for example, a quadrilateral shape (square shape). However, the planar shape of the outer peripheral edge of each layer of the cathode layer 30 may also be a rectangular shape, which is a quadrilateral shape other than the square shape. In addition, it may also be other shapes such as a polygon, a circular shape, or an elliptical shape other than the quadrilateral shape.

[0058] In this specification, the thickness direction refers to the thickness direction of the capacitor element. For example, in Figure 1 it is determined by the up and down direction.

[0059] In the capacitor element 1, a capacitor portion is constituted by the anode plate 10, the dielectric layer 20, and the cathode layer 30.

[0060] The insulating layer 40 is formed of an insulating material.

[0061] Examples of the insulating material constituting the insulating layer 40 include polyphenylene sulfone (PPS), polyethersulfone (PES), cyanate ester resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition composed of soluble polyimide siloxane and epoxy resin, polyimide resin, polyamideimide resin, their derivatives or precursors, and the like.

[0062] The insulating layer 40 is provided on the surface of the dielectric layer 20. The insulating layer 40 is provided so as to partially overlap with the cathode layer 30. In addition, the insulating layer 40 is provided on the peripheral edge of the cathode layer 30.

[0063] In Figure 1 the insulating layer 40 includes: a first insulating layer 40A provided in a region surrounding the solid electrolyte layer 31 on the surface of the dielectric layer 20; and a second insulating layer 40B provided on the surface of the first insulating layer 40A, and the second insulating layer 40B is provided so as to partially overlap with the solid electrolyte layer 31.

[0064] Figure 2 is an enlarged representation ofFigure 1 Schematic diagram of an example of the region of the capacitor element surrounded by a dashed line.

[0065] As Figure 1 and Figure 2 shown, when the layer thickness of the overlapping portion 34 of the cathode layer 30 and the insulating layer 40 at the end 40a of the insulating layer 40 overlapping the cathode layer 30 is set to d1 and the layer thickness of the insulating layer 40 is set to d2, the capacitor element 1 satisfies d1 ≥ 0.2 × d2. Thus, the layer thickness difference between the cathode layer 30 and the insulating layer 40 and their switching portion (overlapping portion 34) can be reduced. Therefore, the pressure applied to each layer when forming the sealing layer 50 by pasting a resin sheet or the like can be made uniform, and the interfacial adhesion between the sealing layer 50 after forming the sealing layer 50 and each layer as its base can be improved. As a result, delamination, such as peeling of the sealing layer 50, can be suppressed.

[0066] Preferably, as Figure 2 shown, the overlapping portion 34 at the end 40a of the insulating layer 40 is composed of at least one of the solid electrolyte layer 31 and the carbon layer as the first conductor layer 32A and the insulating layer 40. In this way, by overlapping at least one of the solid electrolyte layer 31 and the carbon layer as the first conductor layer 32A and the insulating layer 40 on the thinnest portion of the switching portion between the cathode layer 30 and the insulating layer 40, the film thickness of the overlapping portion 34 that is likely to become thinner during molding can be effectively increased. Therefore, the pressure during the formation of the sealing layer 50 can be further made uniform, and the interfacial adhesion between the sealing layer 50 after forming the sealing layer 50 and each layer as its base can be further improved.

[0067] In addition, it may be that, as Figure 2 shown, the overlapping portion 34 at the end 40a of the insulating layer 40 is composed only of the solid electrolyte layer 31 and the insulating layer 40. In this case, the layer thickness d1 corresponds to the layer thickness of the solid electrolyte layer 31 at the end 40a of the insulating layer 40.

[0068] Figure 3 is an enlarged view showing Figure 1 schematic diagram of another example of the region of the capacitor element surrounded by a dashed line.

[0069] It may also be that, as Figure 3 shown, the overlapping portion 34 at the end 40a of the insulating layer 40 is composed only of the solid electrolyte layer 31, the carbon layer as the first conductor layer 32A, and the insulating layer 40. In this case, the layer thickness d1 corresponds to the layer thickness of the layer formed by combining the solid electrolyte layer 31 and the carbon layer (first conductor layer 32A) at the end 40a of the insulating layer 40.

[0070] The end 40a of the insulating layer 40 may be the end of the first insulating layer 40A or, as Figure 2 andFigure 3 is the end of the second insulating layer 40B as shown. In addition, as Figure 2 and Figure 3 shown, the "end of the insulating layer" means the critical location where the insulating layer disappears.

[0071] The capacitor element 1 preferably satisfies d1≥0.2×d2, and more preferably satisfies d1≥0.5×d2.

[0072] The capacitor element 1 preferably satisfies d1≤d2. In the case where d1>d2 conversely, when the capacitor element 1 is sealed with the sealing layer 50, the insulating layer 40 is lower than the cathode layer 30, so the sealing material used as the material of the sealing layer 50 is likely to flow into the later-described breaking portions 61 and 62, and the adhesion between the insulating layer 40 near the breaking portions 61 and 62 and the sealing layer 50 may be reduced. On the other hand, in the case where d1≤d2, the amount of the sealing material flowing into the breaking portions 61 and 62 can be suppressed, and the reduction of the adhesion between the insulating layer 40 near the breaking portions 61 and 62 and the sealing layer 50 can be suppressed. In addition, the number of irregularities caused by the height difference between d1 and d2 can be increased, and the mechanical anchoring effect can also be improved.

[0073] The capacitor element 1 preferably satisfies d1≥2μm, and more preferably satisfies d1≥5μm. By satisfying d1≥2μm, even when the capacitor element 1 is miniaturized, the minimum layer thickness can be ensured by the overlapping portion 34, and the interface adhesion can be guaranteed.

[0074] The capacitor element 1 preferably satisfies d1≤100μm, and more preferably satisfies d1≤40μm. By satisfying d1≤100μm, even when the capacitor element 1 is miniaturized or enlarged, a structure that can guarantee the adhesion between the thinnest portion of the switching portion between the cathode layer 30 and the insulating layer 40 and the sealing layer 50 can be provided.

[0075] From the same viewpoint, the insulating layer 40 preferably satisfies 10μm≤d2≤500μm, and more preferably satisfies 25μm≤d2≤200μm.

[0076] From the same viewpoint, when the layer thickness of the cathode layer 30 is set as d3, the cathode layer 30 preferably satisfies 10μm≤d3≤500μm, and more preferably satisfies 25μm≤d3≤200μm.

[0077] In addition, in the capacitor element of the present invention, the above-described features related to the layer thicknesses d1, d2, and d3 only need to be satisfied at at least one portion in a cross section parallel to the thickness direction, but when there are a plurality of portions in the cross section that can satisfy the above features, it is preferable to satisfy the above features at all portions.

[0078] In addition, in the capacitor element of the present invention, the layer thickness d2 of the insulating layer refers to the layer thickness of the insulating layer itself that constitutes the overlapping portion which is the measurement object of the layer thickness d1 in a cross section parallel to the thickness direction. That is, in this cross section, the portion that is the measurement object of the layer thickness d1 is adjacent to the portion that is the measurement object of the layer thickness d2.

[0079] The insulating layer 40 is formed, for example, by coating an insulating material on the surface of the dielectric layer 20 that overlaps the periphery of the solid electrolyte layer 31 so as to surround the formation region or a predetermined region of the conductor layer 32 at the periphery of the solid electrolyte layer 31.

[0080] Examples of the insulating material constituting the first insulating layer 40A and the second insulating layer 40B include polyphenylsulfone, polyethersulfone, cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition composed of soluble polyimide siloxane and epoxy resin, polyimide resin, polyamideimide resin, their derivatives or precursors, and the like.

[0081] The insulating material constituting the first insulating layer 40A and the insulating material constituting the second insulating layer 40B may be the same or different.

[0082] It is also possible that the first insulating layer 40A is formed of the same resin as the sealing layer 50 described later. If it is different from the sealing layer 50 and the first insulating layer 40A contains an inorganic filler, it may have an adverse effect on the effective part of the capacitor element 1. Therefore, it is preferable that the first insulating layer 40A is formed of a single resin category.

[0083] The thickness of the first insulating layer 40A may be the same as the thickness of the second insulating layer 40B, may be larger than the thickness of the second insulating layer 40B, or may be smaller than the thickness of the second insulating layer 40B.

[0084] The thickness of the first insulating layer 40A may be the same as the thickness of the solid electrolyte layer 31, may be larger than the thickness of the solid electrolyte layer 31, or may be smaller than the thickness of the solid electrolyte layer 31.

[0085] The thickness of the second insulating layer 40B may be the same as the thickness of the conductor layer 32, may be larger than the thickness of the conductor layer 32, or may be smaller than the thickness of the conductor layer 32.

[0086] In Figure 1 In the example shown, the insulating layer 40 includes the first insulating layer 40A and the second insulating layer 40B, but it is also possible that the insulating layer 40 includes other layers in addition to the first insulating layer 40A and the second insulating layer 40B.

[0087] Preferably, the capacitor element 1 further has a sealing layer 50.

[0088] The sealing layer 50 contains a resin material.

[0089] Examples of the resin material contained in the sealing layer 50 include epoxy resin, phenolic resin, polyimide resin, etc.

[0090] Alternatively, the sealing layer 50 may contain inorganic fillers such as silica and alumina in addition to the resin material.

[0091] The sealing layer 50 may be composed of only one layer or two or more layers.

[0092] The sealing layer 50 covers the insulating layer 40 and the cathode layer 30.

[0093] In the capacitor element 1, by providing the sealing layer 50 that covers the insulating layer 40 and the cathode layer 30, deformation caused by external force is suppressed, and accordingly, the occurrence of delamination is further suppressed. By the capacitor element having a sealing layer that contains a resin material and covers the insulating layer and the cathode layer, deformation caused by external force is suppressed, and accordingly, the occurrence of delamination is further suppressed.

[0094] Alternatively, the sealing layer 50 may be provided in such a manner that a part of the anode plate 10, particularly the end face of the core portion 11, is exposed from the sealing layer 50. In this case, even if the sealing layer 50 is provided, the anode plate 10 can be connected to the outside of the sealing layer 50.

[0095] The sealing layer 50 is formed in a predetermined area, for example, by a method of pasting a resin sheet so as to cover the cathode layer 30, a method of coating a resin slurry so as to cover the cathode layer 30, or the like.

[0096] The capacitor element 1 is manufactured, for example, by the following method.

[0097] First, an anode plate 10 having porous layers 12 on two main surfaces of the core portion 11, that is, an anode plate 10 having porous layers 12 on two main surfaces, is prepared. Then, by subjecting the anode plate 10 to an anodization treatment, an oxide coating film that becomes the dielectric layer 20 is formed on the surface of the porous layer 12.

[0098] Next, an insulating material is coated on the surface of the dielectric layer 20, and a first insulating layer 40A is formed so as to surround a predetermined area for forming the solid electrolyte layer 31.

[0099] Then, by repeatedly performing a process of coating a dispersion liquid of a conductive polymer on the surface of the dielectric layer 20 and drying it multiple times on the area surrounded by the first insulating layer 40A, the solid electrolyte layer 31 is formed.

[0100] Next, an insulating material is coated on the surface of the first insulating layer 40A to form a second insulating layer 40B so as to cover the entire end portion of the solid electrolyte layer 31 when viewed from above in the thickness direction.

[0101] Next, a first conductor layer 32A provided on the surface of the solid electrolyte layer 31 is formed by coating a conductive paste containing a conductive filler on the surface of the solid electrolyte layer 31. Thereafter, a second conductor layer 32B provided on the surface of the first conductor layer 32A is formed by coating a metal paste containing a metal filler on the surface of the first conductor layer 32A. In this way, a conductor layer 32 including the first conductor layer 32A and the second conductor layer 32B is formed. Through the above steps, a solid electrolytic capacitor chip is obtained.

[0102] Next, a capacitor element 1 is manufactured by pasting resin sheets on both main surfaces of the solid electrolytic capacitor chip to form a sealing layer 50 that covers the conductor layer 32.

[0103] [Embodiment 2]

[0104] Figure 4 FIG. is a plan view showing an example of a capacitor array according to Embodiment 2 of the present invention. Figure 5 It shows Figure 4 A cross-sectional view showing an example of a cross-section along line A-A of the capacitor array shown.

[0105] Figure 6 It shows Figure 4 A cross-sectional view showing an example of a cross-section along line B-B of the capacitor array shown.

[0106] Figures 4 to 6 The capacitor array 101 shown has a plurality of Figure 1 The capacitor elements 1 shown. In Figures 4 to 6 In the example shown, the capacitor array 101 has four capacitor elements 1.

[0107] In the capacitor array 101 in which a plurality of capacitor elements 1 are arranged in an array, deformation caused by external force is suppressed, and delamination between layers of a plurality of different materials is less likely to occur, particularly delamination between the porous layer 12 and the solid electrolyte layer 31.

[0108] In addition, by arranging a plurality of capacitor elements 1 in an array to form a capacitor array 101, a multi-channel structure capacitor array with optimized capacitance and position can be provided according to market requirements.

[0109] Moreover, by using the capacitor array 101 in which a plurality of capacitor elements 1 are arranged in an array, the plurality of capacitor elements 1 can be efficiently mounted on a substrate.

[0110] The plurality of capacitor elements 1 can be arranged in a planar shape or in a linear shape.

[0111] The plurality of capacitor elements 1 can be arranged regularly or irregularly.

[0112] When viewed from the thickness direction, the areas of the plurality of capacitor elements 1 can be the same as each other, different from each other, or partially different.

[0113] When viewed from the thickness direction, the planar shapes of the plurality of capacitor elements 1 can be the same as each other, different from each other, or partially different.

[0114] Preferably, the capacitor array 101 has a sealing portion 60.

[0115] The sealing portion 60 seals the plurality of capacitor portions from both main surface sides that are opposite to each other in the thickness direction of the plurality of capacitor portions. Thus, the plurality of capacitor portions are protected by the sealing portion 60.

[0116] The sealing portion 60 is made of an insulating material. That is, the sealing portion 60 functions as an insulating portion.

[0117] The sealing portion 60 is formed by laminating a plurality of sealing layers in the thickness direction.

[0118] The plurality of sealing layers constituting the sealing portion 60 include a first sealing layer 60A and a second sealing layer 60B. In Figure 5 In the example shown in etc., the sealing portion 60 is formed by laminating the first sealing layer 60A and the second sealing layer 60B in sequence from the capacitor portion side in the thickness direction. That is, in Figure 5 In the example shown in etc., the second sealing layer 60B is adjacent to the first sealing layer 60A on the side opposite to the capacitor portion with respect to the first sealing layer 60A.

[0119] The sealing portion 60 only needs to include at least the first sealing layer 60A and the second sealing layer 60B, and it may also be that at least one more sealing layer is included between the first sealing layer 60A and the second sealing layer 60B.

[0120] It may also be that the insulating material constituting the first sealing layer 60A contains an insulating resin.

[0121] Examples of the insulating resin contained in the insulating material constituting the first sealing layer 60A include epoxy resin, phenolic resin, polyimide resin, etc.

[0122] It may also be that the insulating material constituting the first sealing layer 60A further contains an inorganic filler.

[0123] Examples of the inorganic filler contained in the insulating material constituting the first sealing layer 60A include silica filler, alumina filler, and the like.

[0124] The first sealing layer 60A is formed, for example, by a method of thermocompression bonding an insulating resin sheet, a method of thermally curing after coating an insulating resin paste, or the like, so as to seal the capacitor portion from both main surface sides of the capacitor portion.

[0125] It is also possible that the insulating material constituting the second sealing layer 60B contains an insulating resin.

[0126] Examples of the insulating resin contained in the insulating material constituting the second sealing layer 60B include epoxy resin, phenolic resin, polyimide resin, and the like.

[0127] Preferably, the insulating materials constituting the first sealing layer 60A and the second sealing layer 60B contain different insulating resins from each other.

[0128] In addition, it is also possible that the insulating materials constituting the first sealing layer 60A and the second sealing layer 60B contain the same insulating resin as each other.

[0129] It is also possible that the insulating material constituting the second sealing layer 60B further contains an inorganic filler.

[0130] Examples of the inorganic filler contained in the insulating material constituting the second sealing layer 60B include silica filler, alumina filler, and the like.

[0131] The inorganic fillers contained in the insulating materials constituting the first sealing layer 60A and the second sealing layer 60B may be the same as or different from each other at least in terms of type.

[0132] In the first sealing layer 60A and the second sealing layer 60B, the ratio of the content of the inorganic filler to the total amount of the insulating material may be the same as or different from each other.

[0133] The second sealing layer 60B is formed, for example, by a method of thermocompression bonding an insulating resin sheet or a method of thermally curing after coating an insulating resin paste after the first sealing layer 60A is formed by the above method, so as to be adjacent to the first sealing layer 60A on the side opposite to the capacitor portion with respect to the first sealing layer 60A. Thus, if the second sealing layer 60B is formed on the first sealing layer 60A by a lamination process, it is not necessary to soften the already formed first sealing layer 60A by the heat treatment during the formation of the second sealing layer 60B. Therefore, when the second sealing layer 60B is formed, the first sealing layer 60A and the second sealing layer 60B do not integrate, and there is an interface between the first sealing layer 60A and the second sealing layer 60B.

[0134] The sealing portion 60 also fills the space between multiple capacitor elements 1. Here, it fills the space between four capacitor elements 1.

[0135] More specifically, the first sealing layer 60A also fills the disconnection portion 61 that disconnects multiple capacitor elements 1 in the Figure 4 longitudinal direction. The first sealing layer 60A also fills the through hole 80 for the via conductor that is electrically connected to the cathode layer 30 described later.

[0136] The second sealing layer 60B also fills the disconnection portion 62 that disconnects multiple capacitor elements 1 in the Figure 4 lateral direction.

[0137] [Embodiment 3]

[0138] Figure 7 It is a top view schematic diagram showing an example of a capacitor array according to Embodiment 3 of the present invention. Figure 8 It shows Figure 7 a cross-sectional schematic diagram showing an example of the cross-section along line A-A of the capacitor array shown.

[0139] Figure 9 It shows Figure 7 a cross-sectional schematic diagram showing an example of the cross-section along line B-B of the capacitor array shown.

[0140] Figures 7 to 9 The shown capacitor array 102 is further provided with a via conductor 70, external electrode layers 71, 72, via conductors 80A, 80B with respect to Figures 4 to 6 the shown capacitor array 101.

[0141] Preferably, as shown in Figure 8 and Figure 9 , the layer thickness d2 is the film thickness of the insulating layer 40 around the via conductor 80A or 80B. The portion where the cathode layer 30 overlaps the insulating layer 40 (layer thickness d1) may exist in the peripheral portion of the via conductors 80A, 80B, and the peripheral portion of the disconnection portions 61, 62. In the peripheral portion of the via conductors 80A, 80B where delamination is more likely to occur, by satisfying d1≥0.2×d2, a higher delamination suppression effect can be obtained.

[0142] The via conductor 70 is arranged to reach the cathode layer 30 from the surface of the sealing portion 60 in the thickness direction. More specifically, it is arranged to reach the second conductor layer 32B from the surface of the sealing portion 60. Thus, the cathode layer 30 is electrically led out to the outside of the sealing portion 60 via the via conductor 70 and can be electrically connected to the outside of the sealing portion 60.

[0143] The via conductor 70 is connected to the external electrode layer 71 provided on the surface of the sealing portion 60.

[0144] As a constituent material of the via conductor 70, low-resistance metals such as silver, gold, and copper can be cited, for example.

[0145] The via conductor 70 is formed, for example, as follows. First, by performing drilling, laser processing, etc. on the sealing portion 60, a hole is provided that reaches the cathode layer 30 in the thickness direction from the surface of the sealing portion 60, and here, a hole that reaches the second conductor layer 32B from the surface of the sealing portion 60. Then, for the hole provided in the sealing layer 50, the via conductor 70 is formed by plating the inner wall surface or performing heat treatment after filling a conductive paste.

[0146] The through-hole conductors 80A and 80B penetrate the sealing portion 60 in the thickness direction. In Figure 8 In the example shown in etc., the through-hole conductors 80A and 80B not only penetrate the sealing portion 60 in the thickness direction but also penetrate the anode plate 10 (core portion 11), the dielectric layer 20, and the insulating layer 40 in the thickness direction.

[0147] By providing a through-hole conductor that penetrates the sealing portion 60 in the thickness direction, an electrical function is imparted to the sealing portion 60.

[0148] Preferably, the through-hole conductor 80A is provided on at least the inner wall surface of the through-hole 81A that penetrates the sealing portion 60 in the thickness direction. In Figure 8 In the example shown in etc., the through-hole conductor 80A is not provided throughout the inside of the through-hole 81A but is provided on the inner wall surface of the through-hole 81A.

[0149] The through-hole conductor 80A is electrically insulated from the anode plate 10. Preferably, as shown in Figure 8 and Figure 9 An insulating material such as the sealing portion 60 is filled between the through-hole conductor 80A and the anode plate 10.

[0150] The through-hole conductor 80A is connected to the external electrode layer 71 provided on the surface of the sealing portion 60. Thus, the through-hole conductor 80A is electrically connected to the cathode layer 30 via the external electrode layer 71 and the via conductor 70.

[0151] Preferably, the through-hole conductor 80B is provided on at least the inner wall surface of the through-hole 81B that penetrates the sealing portion 60 in the thickness direction. In Figure 8 In the example shown in etc., the through-hole conductor 80B is not provided throughout the inside of the through-hole 81B but is provided on the inner wall surface of the through-hole 81B.

[0152] The through-hole conductor 80B is electrically connected to the anode plate 10. Preferably, as shown in Figure 8 and Figure 9As shown, the through-hole conductor 80B is electrically connected to the anode plate 10 at the inner wall surface of the through-hole 81B. More specifically, preferably, the through-hole conductor 80B is electrically connected to the end face of the anode plate 10 that faces the inner wall surface of the through-hole 81B in a direction orthogonal to the thickness direction. In Figure 8 In the examples shown in etc., the through-hole conductor 80B is connected to the end face of the anode plate 10, particularly the end face of the core portion 11. Thereby, the anode plate 10 is electrically led out to the outside via the through-hole conductor 80B. That is, the sealing portion 60 is given an electrical function of electrically leading out the anode plate 10 to the outside. And, the through-hole conductor 80B is connected to the external electrode layer 72 provided on the surface of the sealing portion 60.

[0153] Preferably, when viewed from the thickness direction, the through-hole conductor 80B is electrically connected to the anode plate 10 over the entire circumference of the through-hole 81B. Thereby, the connection resistance between the through-hole conductor 80B and the anode plate 10 is easily reduced, and thus the equivalent series resistance of the capacitor element 1 is easily reduced.

[0154] The through-hole conductor 80A is formed as follows, for example. First, through-hole machining such as drilling or laser machining is performed to provide a through-hole that penetrates the anode plate 10 (core portion 11), the dielectric layer 20, and the insulating layer 40 in the thickness direction. Next, by forming the sealing portion 60, an insulating material is filled into the above-mentioned through-hole. Through-hole machining such as drilling or laser machining is performed on the portion filled with the insulating material to provide a through-hole 81A that penetrates the sealing portion 60 in the thickness direction. At this time, by making the diameter of the through-hole 81A smaller than the diameter of the through-hole filled with the insulating material, a state is provided in which an insulating material exists between the inner wall surface of the through-hole formed earlier in the plane direction and the inner wall surface of the through-hole 81A. Then, the inner wall surface of the through-hole 81A is metallized using a low-resistance metal such as copper, gold, or silver to form the through-hole conductor 80A. When forming the through-hole conductor 80A, for example, the inner wall surface of the through-hole 81A is metallized by electroless copper plating treatment, electrolytic copper plating treatment, etc., and the processing becomes easy. In addition, regarding the method of forming the through-hole conductor 80A, in addition to the method of metallizing the inner wall surface of the through-hole 81A, it may also be a method of filling the through-hole 81A with a metal, a composite material of metal and resin, etc.

[0155] The through-hole conductor 80B is formed as follows, for example. First, a through-hole 81B that penetrates the sealing portion 60, the anode plate 10 (core portion 11), the dielectric layer 20, and the insulating layer 40 in the thickness direction is provided by performing drilling, laser processing, etc. Then, the inner wall surface of the through-hole 81B is metallized using a metal with low resistance such as copper, gold, or silver to form the through-hole conductor 80B. When forming the through-hole conductor 80B, for example, the inner wall surface of the through-hole 81B is metallized by electroless copper plating treatment, electrolytic copper plating treatment, etc., making the processing easier. In addition, regarding the method of forming the through-hole conductor 80B, in addition to the method of metallizing the inner wall surface of the through-hole 81B, it can also be a method of filling the through-hole 81B with a metal, a composite material of metal and resin, etc.

[0156] The external electrode layer 71 is electrically connected to the cathode layer 30. In Figure 8 In the example shown in etc., the external electrode layer 71 is provided on the surface of the through-hole conductor 80A and functions as a connection terminal of the capacitor array 102 (capacitor element 1). In Figure 8 In the example shown in etc., the external electrode layer 71 is electrically connected to the cathode layer 30 via the via conductor 70 and functions as a connection terminal for the cathode layer 30.

[0157] As a constituent material of the external electrode layer 71, for example, a metal material containing a metal with low resistance such as silver, gold, or copper can be cited. In this case, the external electrode layer 71 is formed, for example, by plating the surface of the through-hole conductor 80A.

[0158] In order to improve the adhesion between the external electrode layer 71 and other components, here, in order to improve the adhesion between the external electrode layer 71 and the through-hole conductor 80A, as a constituent material of the external electrode layer 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 can also be used.

[0159] The external electrode layer 72 is electrically connected to the anode plate 10. In Figure 8 In the example shown in etc., the external electrode layer 72 is provided on the surface of the through-hole conductor 80B and functions as a connection terminal of the capacitor array 101 (capacitor element 1). In Figure 8 In the example shown in etc., the external electrode layer 72 is electrically connected to the anode plate 10 via the through-hole conductor 80B and functions as a connection terminal for the anode plate 10.

[0160] As a constituent material of the external electrode layer 72, for example, a metal material containing a metal with low resistance such as silver, gold, or copper can be cited. In this case, the external electrode layer 72 is formed, for example, by plating the surface of the through-hole conductor 80B.

[0161] In order to improve the adhesion between the external electrode layer 72 and other components, here, in order to improve the adhesion between the external electrode layer 72 and the via conductor 80B, as the constituent material of the external electrode layer 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 can also be used.

[0162] The constituent materials of the external electrode layer 71 and the external electrode layer 72 are preferably the same as each other at least in terms of type, but they can also be different from each other.

[0163] In Figures 7 to 9 In the example shown, in each of the plurality of capacitor elements 1, an external electrode layer 71 electrically connected to the cathode layer 30 and an external electrode layer 72 electrically connected to the anode plate 10 are provided, but they can also be provided in such a way that at least one of the external electrode layer 71 and the external electrode layer 72 is shared among the plurality of capacitor elements 1.

[0164] In Figures 7 to 9 In the example shown, the external electrode layer 71 and the external electrode layer 72 are provided on both main surface sides of the sealing portion 60, but they can also be provided only on one main surface side of the sealing portion 60.

[0165] Preferably, the capacitor array 102 further has a resin filling portion 90A formed by filling a resin material into the through hole 81A. In Figure 8 In the example shown, etc., the resin filling portion 90A is provided in a space surrounded by the via conductor 80A on the inner wall surface of the through hole 81A. If the space in the through hole 81A is eliminated by providing the resin filling portion 90A, the occurrence of delamination of the via conductor 80A is suppressed.

[0166] In addition, the capacitor array 102 may not have the resin filling portion 90A. In this case, preferably, the via conductor 80A is provided not only on the inner wall surface of the through hole 81A but also throughout the inside of the through hole 81A.

[0167] Preferably, the capacitor array 102 further has a resin filling portion 90B formed by filling a resin material into the through hole 81B. In Figure 8 In the example shown, etc., the resin filling portion 90B is provided in a space surrounded by the via conductor 80B on the inner wall surface of the through hole 81B. If the space in the through hole 81B is eliminated by providing the resin filling portion 90B, the occurrence of delamination of the via conductor 80B is suppressed.

[0168] In addition, the capacitor array 102 may not have the resin filling portion 90B. In this case, preferably, the via conductor 80B is provided not only on the inner wall surface of the through hole 81B but also throughout the inside of the through hole 81B.

[0169] The capacitor element of the present invention is used, for example, in a composite electronic component. Such a composite electronic component has, for example: the capacitor element of the present invention; an external electrode provided on the outside of the capacitor element of the present invention and electrically connected to the anode plate and the cathode layer respectively; and an electronic component electrically connected to the external electrode.

[0170] In the composite electronic component, the electronic component electrically connected to the external electrode can be either a passive component, an active component, both a passive component and an active component, or a composite of a passive component and an active component.

[0171] Examples of the passive component include an inductor and the like.

[0172] Examples of the active component include a memory, a GPU (Graphics Processing Unit), a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a PMIC (Power Management IC), and the like.

[0173] When the capacitor element of the present invention is used in a composite electronic component, the capacitor element of the present invention is used, for example, as a substrate for mounting an electronic component as described above. Therefore, by making the entire capacitor element of the present invention sheet-shaped and making the electronic component mounted on the capacitor element of the present invention sheet-shaped, the capacitor element of the present invention and the electronic component can be electrically connected in the thickness direction through a via conductor that penetrates the electronic component in the thickness direction. As a result, the passive component and the active component as electronic components can be configured as an integrated module.

[0174] For example, 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, a switching regulator can be formed.

[0175] Alternatively, in the composite electronic component, a circuit layer may be formed on one main surface of a capacitor element sheet on which a plurality of capacitor elements of the present invention are arranged, and on this basis, the circuit layer may be electrically connected to a passive component or an active component as an electronic component.

[0176] In addition, it may be that after the capacitor element of the present invention is disposed in a cavity portion provided in advance on a substrate and embedded with resin, a circuit layer is formed on the resin. It may also be that a passive component or an active component as another electronic component is mounted in other cavity portions of the substrate.

[0177] Alternatively, it is also possible that after the capacitor element of the present invention is mounted on a smooth carrier such as a wafer or glass and an outer resin layer is formed, a circuit layer is formed, and on this basis, the circuit layer is electrically connected to a passive element or an active element as an electronic component.

[0178] In this specification, the following content is disclosed.

[0179] <1>

[0180] A capacitor element, characterized in that

[0181] The capacitor element includes:

[0182] An anode plate having a porous layer on at least one main surface;

[0183] A dielectric layer provided on the surface of the porous layer;

[0184] A cathode layer provided on the surface of the dielectric layer; and

[0185] An insulating layer provided on the surface of the dielectric layer so as to partially overlap with the cathode layer,

[0186] When the layer thickness of the part of the cathode layer overlapping with the insulating layer at the end of the insulating layer overlapping with the cathode layer is set as d1 and the layer thickness of the insulating layer is set as d2,

[0187] d1≥0.2×d2 is satisfied.

[0188] <2>

[0189] The capacitor element according to <1>, wherein

[0190] d1≤d2 is satisfied.

[0191] <3>

[0192] The capacitor element according to <1> or <2>, wherein

[0193] d1≥2μm is satisfied.

[0194] <4>

[0195] The capacitor element according to <3>, wherein

[0196] d1≤100μm is satisfied.

[0197] <5>

[0198] The capacitor element according to any one of <1> to <4>, wherein

[0199] 10μm≤d2≤500μm is satisfied.

[0200] <6>

[0201] The capacitor element according to any one of <1> to <5>, wherein,

[0202] When the layer thickness of the cathode layer is set to d3,

[0203] 10 μm ≤ d3 ≤ 500 μm is satisfied.

[0204] <7>

[0205] The capacitor element according to any one of <1> to <6>, wherein,

[0206] The cathode layer includes a solid electrolyte layer provided on the surface of the dielectric layer and a carbon layer provided on the surface of the solid electrolyte layer,

[0207] The overlapping portion includes at least one of the solid electrolyte layer and the carbon layer and the insulating layer.

[0208] <8>

[0209] The capacitor element according to <7>, wherein,

[0210] The overlapping portion only includes the solid electrolyte layer and the insulating layer.

[0211] <9>

[0212] The capacitor element according to <7>, wherein,

[0213] The overlapping portion only includes the solid electrolyte layer, the carbon layer, and the insulating layer.

[0214] <10>

[0215] The capacitor element according to any one of <1> to <9>, wherein,

[0216] The capacitor element further includes a sealing layer covering the insulating layer and the cathode layer.

[0217] Explanation of reference numerals

[0218] 1. Capacitor element; 10. Anode plate; 11. Core part; 12. Porous layer; 20. Dielectric layer; 30. Cathode layer; 31. Solid electrolyte layer; 32. Conductor layer; 32A. First conductor layer; 32B. Second conductor layer; 34. Portion where the cathode layer overlaps with the insulating layer; 40. Insulating layer; 40a. End of the insulating layer that overlaps with the cathode layer; 40A. First insulating layer; 40B. Second insulating layer; 50. Sealing layer; 60. Sealing part; 60A. First sealing layer; 60B. Second sealing layer; 61, 62. Disconnection part; 70. Path conductor; 71, 72. External electrode layer; 80A, 80B. Through-hole conductor; 81A, 81B. Through-hole; 90A, 90B. Resin filling part; 101, 102. Capacitor array.

Claims

1. A capacitor element, characterized in that, the capacitor element comprises: an anode plate having a porous layer on at least one main surface; a dielectric layer provided on the surface of the porous layer; a cathode layer provided on the surface of the dielectric layer; and an insulating layer provided on the surface of the dielectric layer so as to partially overlap with the cathode layer, when the layer thickness of the portion of the cathode layer overlapping with the insulating layer at the end of the insulating layer overlapping with the cathode layer is set as d1 and the layer thickness of the insulating layer is set as d2, it satisfies d1≥0.2×d2.

2. The capacitor element according to claim 1, wherein, it satisfies d1≤d2.

3. The capacitor element according to claim 1 or 2, wherein, it satisfies d1≥2μm.

4. The capacitor element according to claim 3, wherein, it satisfies d1≤100μm.

5. The capacitor element according to any one of claims 1 to 4, wherein, it satisfies 10μm≤d2≤500μm.

6. The capacitor element according to any one of claims 1 to 5, wherein, when the layer thickness of the cathode layer is set as d3, it satisfies 10μm≤d3≤500μm.

7. The capacitor element according to any one of claims 1 to 6, wherein, the cathode layer includes a solid electrolyte layer provided on the surface of the dielectric layer and a carbon layer provided on the surface of the solid electrolyte layer, the overlapping portion includes at least one of the solid electrolyte layer and the carbon layer and the insulating layer.

8. The capacitor element according to claim 7, wherein, the overlapping portion only includes the solid electrolyte layer and the insulating layer.

9. The capacitor element according to claim 7, wherein, the overlapping portion only includes the solid electrolyte layer, the carbon layer and the insulating layer.

10. The capacitor element according to any one of claims 1 to 9, wherein, the capacitor element further includes a sealing layer covering the insulating layer and the cathode layer.

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