Capacitor element

Abstract

A capacitor element (1) is provided with: a capacitor section (10) that includes an anode plate (11) having a porous section (11B) on at least one main surface of a core section (11A), a dielectric layer (13) provided on the surface of the porous section (11B), and a cathode layer (12) provided on the surface of the dielectric layer (13); and a sealing layer (30) that seals the capacitor part (10), and a slit (40) is provided in the surface of the sealing layer (30).

Description

Technical Field

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

[0002] Patent document 1 discloses a capacitor array, which includes: a plurality of solid electrolytic capacitor elements, which are divided from a solid electrolytic capacitor sheet; a sheet-shaped first sealing layer; and a sheet-shaped second sealing layer. The solid electrolytic capacitor sheet includes: an anode plate, which is formed of a valve-acting metal; a porous layer, which is provided on at least one main surface of the anode plate; a dielectric layer, which is provided on the surface of the porous layer; and a cathode layer, which includes a solid electrolyte layer provided on the surface of the dielectric layer, and 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 side of each of the plurality of solid electrolytic capacitor elements is arranged on the first sealing layer. The second sealing layer is arranged in a manner that covers the plurality of solid electrolytic capacitor elements on the first sealing layer from the second main surface side. The solid electrolytic capacitor elements are divided by a slit-shaped sheet removal portion.

[0003] Prior art literature

[0004] Patent Literature

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

[0006] Problem that the invention aims to solve

[0007] Patent Document 1 discloses that a stress relief layer may be provided between a solid electrolytic capacitor element and a first sealing layer or a second sealing layer. According to Patent Document 1, by providing a stress relief layer at the above-mentioned location, the stress generated between the inside and outside of the capacitor array can be relieved without losing the capabilities (resistance, barrier performance, etc.) required by the outermost conductor and insulating portion of the solid electrolytic capacitor element and the capabilities (easy to closely adhere to wiring, easy to form smoothly, etc.) required by the sealing layer.

[0008] FIG. 25, FIG. 27, and FIG. 29 of Patent Document 1 show cross sections of a capacitor array including a stress relaxation layer. However, if the stress relaxation layer is provided only at the locations shown in FIG. 25, FIG. 27, and FIG. 29 of Patent Document 1, peeling of the effective capacitance portion of the solid electrolytic capacitor element may occur, for example, the cathode layer may peel off from the anode plate.

[0009] The above-mentioned problem is not limited to the structure in which a plurality of capacitor units are arranged inside the sealing layer, but is a problem that occurs also in the structure in which a single capacitor unit is arranged inside the sealing layer.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a capacitor element capable of suppressing separation at a capacitance effective portion.

[0011] Solutions for solving problems

[0012] The capacitor element of the present invention comprises: a capacitor portion, which includes an anode plate, a dielectric layer and a cathode layer, wherein the anode plate has a porous portion on at least one main surface of a core portion, the dielectric layer is arranged on the surface of the porous portion, and the cathode layer is arranged on the surface of the dielectric layer; and a sealing layer, which seals the capacitor portion, and a slit is provided on the surface of the sealing layer.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to provide a capacitor element capable of suppressing separation at a capacitance effective portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view schematically showing an example of the capacitor element of the present invention.

[0016] Figure 2A yes Figure 1 A top view of the capacitor element along line A is shown.

[0017] Figure 2B yes Figure 1 A top view of the capacitor element along line B is shown.

[0018] Figure 3 It is a cross-sectional view schematically showing a first modified example of the capacitor element according to the present invention.

[0019] Figure 4 is Figure 3 An enlarged view of the portion indicated by a in FIG.

[0020] Figure 5 It is a cross-sectional view schematically showing a second modified example of the capacitor element of the present invention.

[0021] Figure 6 It is a plan view schematically showing an example of a capacitor element assembly. DETAILED DESCRIPTION

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

[0023] In this specification, terms indicating the relationship between elements (such as "vertical", "parallel", "orthogonal", etc.) and terms indicating the shape of an element do not express only strict meanings, but rather express substantially equivalent ranges, for example, also including differences of several percentages.

[0024] The drawings shown below are schematic diagrams, and their dimensions, aspect ratios, etc. may differ from those of actual products. The same reference numerals are used for the same or equivalent parts in the drawings. In addition, in each figure, the same reference numerals are marked for the same elements and repeated descriptions are omitted.

[0025] Figure 1 It is a cross-sectional view schematically showing an example of the capacitor element of the present invention. Figure 2A yes Figure 1 A top view of the capacitor element along line A is shown. Figure 2B yes Figure 1 A top view of the capacitor element along line B is shown.

[0026] Figure 1 , Figure 2A as well as Figure 2B The capacitor element 1 shown includes a capacitor portion 10 and a sealing layer 30 that seals the capacitor portion 10 .

[0027] exist Figure 1 , Figure 2A as well as Figure 2B In the example shown, two capacitor units 10 are arranged inside the sealing layer 30. The number of capacitor units 10 arranged inside the sealing layer 30 is not particularly limited, and may be one or more.

[0028] The capacitor unit 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. Thus, the capacitor unit 10 constitutes an electrolytic capacitor. Figure 1 In the example shown, 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 formed on only one main surface of the core portion 11A.

[0029] Cathode layer 12 includes, for example, solid electrolyte layer 12A provided on the surface of dielectric layer 13. Preferably, cathode layer 12 further includes conductor layer 12B provided on the surface of solid electrolyte layer 12A. When cathode layer 12 includes solid electrolyte layer 12A, capacitor unit 10 constitutes a solid electrolytic capacitor.

[0030] Preferably, if Figure 1As shown, the sealing layer 30 is provided on two main surfaces facing each other in the thickness direction of the capacitor unit 10. The sealing layer 30 protects the capacitor unit 10.

[0031] The sealing layer 30 may be composed of only one layer or may be composed of two or more layers. When the sealing layer 30 is composed of two or more layers, the materials constituting the respective layers may be the same or different.

[0032] The sealing layer 30 is formed so as to seal the capacitor unit 10 by, for example, a method of thermocompression bonding an insulating resin sheet or a method of applying an insulating resin paste and then thermally curing the paste.

[0033] A slit 40 is provided on the surface of the sealing layer 30. Preferably, Figure 1 and Figure 2B As shown, a plurality of slits 40 are provided on the surface of the sealing layer 30 .

[0034] By providing the slits 40 on the surface of the sealing layer 30 , stress caused by warping or the like can be alleviated. Therefore, peeling at the effective capacitance portion can be suppressed. As a result, degradation of the equivalent series resistance (ESR) can be reduced.

[0035] When the sealing layer 30 is provided on both main surfaces of the capacitor unit 10, the slit 40 may be provided on the surface of only the sealing layer 30 provided on any one main surface, but preferably, the slit 40 is provided on the surface of the sealing layer 30 provided on both main surfaces. When the slit 40 is provided on the surface of the sealing layer 30 provided on both main surfaces of the capacitor unit 10, the position, cross-sectional shape, planar shape, depth, etc. of the slit 40 may be the same on one main surface side and the other main surface side of the capacitor unit 10, or may be partially or completely different.

[0036] Preferably, the slit 40 is provided at a position that does not contact the cathode layer 12. By providing the slit 40 at a position that does not contact the cathode layer 12, even when delamination occurs, delamination can occur preferentially near the slit 40, not near the cathode layer 12. Thus, delamination at the effective portion of the capacity can be suppressed. As a result, degradation of the ESR can be reduced.

[0037] When the cathode layer 12 includes the solid electrolyte layer 12A and the conductor layer 12B, the slit 40 is preferably provided at a position not in contact with the conductor layer 12B. When a plurality of slits 40 are provided on the surface of the sealing layer 30, at least one slit 40 is preferably provided at a position not in contact with the conductor layer 12B.

[0038] Capacitor element 1 may further include external electrode layer 50 provided on the surface of sealing layer 30 .

[0039] 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 .

[0040] Capacitor element 1 may further include a lead conductor provided inside sealing layer 30 and led out to the surface of sealing layer 30 .

[0041] Examples of the lead conductor include a through-hole conductor 70 and a via conductor 90 .

[0042] 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 .

[0043] As the first lead conductor, for example, there can be mentioned a first through-hole conductor 71. Inside the cathode layer 12, one first through-hole conductor 71 may be provided, or two or more first through-hole conductors 71 may be provided.

[0044] As the second lead conductor, for example, there can be cited a second through-hole conductor 72, a via conductor 90, etc. In the cathode layer 12, one second through-hole conductor 72 may be provided, or two or more second through-hole conductors 72 may be provided. In addition, in the cathode layer 12, one via conductor 90 may be provided, or two or more via conductors 90 may be provided.

[0045] exist Figure 1 In the example shown, the capacitor element 1 includes a first through-hole conductor 71 as a first lead conductor. In this case, it is preferable that the slit 40 is provided at a position that does not contact the cathode layer 12 and the first through-hole conductor 71. By providing the slit 40 at a position that does not contact the first lead conductor such as the first through-hole conductor 71, it is possible to suppress peeling at the first lead conductor. As a result, it is possible to reduce degradation of the ESR.

[0046] Moreover, in Figure 1 In the example shown, the capacitor element 1 includes the first external electrode layer 51. In this case, it is preferable that the slit 40 is provided at a position that does not contact the cathode layer 12, the first through-hole conductor 71, and the first external electrode layer 51. By providing the slit 40 at a position that does not contact the first external electrode layer 51, it is possible to suppress peeling at the first external electrode layer 51. As a result, it is possible to reduce degradation of the ESR.

[0047] In addition, Figure 1In the example shown, the capacitor element 1 includes the second through-hole conductor 72 and the via conductor 90 as the second lead conductor. In this case, it is preferable that the slit 40 is provided at a position that does not contact the cathode layer 12, the second through-hole conductor 72, and the via conductor 90. By providing the slit 40 at a position that does not contact the second lead conductor such as the second through-hole conductor 72 and the via conductor 90, it is possible to suppress peeling at the second lead conductor. As a result, it is possible to reduce degradation of the ESR.

[0048] Moreover, in Figure 1 In the example shown, the capacitor element 1 includes the second external electrode layer 52. In this case, it is preferable that the slit 40 is provided at a position that does not contact the cathode layer 12, the second through-hole conductor 72, the via conductor 90, and the second external electrode layer 52. By providing the slit 40 at a position that does not contact the second external electrode layer 52, it is possible to suppress peeling at the second external electrode layer 52. As a result, it is possible to reduce degradation of the ESR.

[0049] When slit 40 is provided at a position not in contact with the second lead conductor, slit 40 may be provided at a position not in contact with both second through-hole conductor 72 and via conductor 90 , or may be provided at a position not in contact with only one of second through-hole conductor 72 and via conductor 90 .

[0050] The method for forming the slit 40 on the surface of the sealing layer 30 is not particularly limited, and for example, laser processing, etching processing and the like can be cited. In the case of simultaneously manufacturing a plurality of capacitor elements 1 using a large sheet containing a plurality of capacitor elements 1, the slit 40 can be formed in a state after being divided into a plurality of capacitor elements 1 (i.e., a monolithic state), or in a state before being divided into a plurality of capacitor elements 1 (i.e., a large sheet state). In the latter case, in addition to the form of the capacitor element 1 as a product, the slit 40 can also be formed according to the tendency of warping, stress, etc.

[0051] The slits 40 may be provided perpendicularly to the surface of the sealing layer 30, may be provided obliquely to the surface of the sealing layer 30, or may be provided curved inside the sealing layer 30. Such slits 40 may be provided in a mixed manner.

[0052] When viewed from above in the thickness direction of the cathode layer 12, the slit 40 may be provided at a position overlapping with the cathode layer 12 or at a position not overlapping with the cathode layer 12. When a plurality of slits 40 are provided on the surface of the sealing layer 30, the slit 40 may be provided at both a position overlapping with the cathode layer 12 and a position not overlapping with the cathode layer 12.

[0053] When viewed from above in the thickness direction of the cathode layer 12, the slit 40 located at a position overlapping with the cathode layer 12 is, for example, provided at a position not overlapping with the external electrode layer 50. For example, in the case where the external electrode layer 50 includes the first external electrode layer 51 and the second external electrode layer 52, when viewed from above in the thickness direction of the cathode layer 12, the slit 40 located at a position overlapping with the cathode layer 12 may also be provided at a position not overlapping with both the first external electrode layer 51 and the second external electrode layer 52.

[0054] Alternatively, when viewed from above in the thickness direction of the cathode layer 12, the slit 40 located at a position overlapping with the cathode layer 12 may be provided at a position overlapping with the external electrode layer 50. For example, in the case where the external electrode layer 50 includes the first external electrode layer 51 and the second external electrode layer 52, when viewed from above in the thickness direction of the cathode layer 12, the slit 40 located at a position overlapping with the cathode layer 12 may be provided at a position overlapping with both the first external electrode layer 51 and the second external electrode layer 52, or at a position overlapping with one of the first external electrode layer 51 and the second external electrode layer 52.

[0055] Figure 3 It is a cross-sectional view schematically showing a first modified example of the capacitor element according to the present invention.

[0056] exist Figure 3 In the capacitor element 1A shown, in the portion indicated by a, the slit 40 located at a position overlapping with the cathode layer 12 is provided at a position overlapping with the external electrode layer 50 (here, the second external electrode layer 52 ).

[0057] Figure 4 is Figure 3 An enlarged view of the portion indicated by a in FIG.

[0058] like Figure 4 As shown, the external electrode layer 50 (here, the second external electrode layer 52) located at a position overlapping the slit 40 may have a step difference. Specifically, the external electrode layer 50 (here, the second external electrode layer 52) located at a position overlapping the slit 40 may be concave. The cross-sectional shape, planar shape, depth, etc. of the concave portion of the external electrode layer 50 are not particularly limited.

[0059] It can also be, as in Figure 3 As shown in the portions indicated by a and b in FIG. 1 , the slits 40 are not provided on the same straight line on the front and back of the capacitor portion 10. Figure 3 In the example shown, the slit 40 located at a position overlapping with the cathode layer 12 in the portion represented by a and the slit 40 located at a position overlapping with the cathode layer 12 in the portion represented by b are not arranged on the same straight line, but the slit 40 located at other positions may also not be arranged on the same straight line on the front and back of the capacitor part 10.

[0060] When a plurality of slits 40 are provided on the surface of the sealing layer 30 , the depths of the slits 40 may be the same, or may be partially or entirely different.

[0061] Figure 5 It is a cross-sectional view schematically showing a second modified example of the capacitor element of the present invention.

[0062] exist Figure 5 In the capacitor element 1B shown, the depth of the slit 40 is different. Figure 5 In the illustrated example, the depths of the two main surface side slits 40 in the capacitor portion 10 are different, but the depth of only one of the main surface side slits 40 may be different.

[0063] Figure 6 It is a plan view schematically showing an example of a capacitor element assembly.

[0064] Figure 6 The capacitor element assembly 100 shown is a large sheet including a plurality of capacitor elements. Figure 6 As shown, the slits 40A, 40B, and 40C can be formed at any position of the capacitor element assembly 100. In addition, the slits 40A, 40B, and 40C may be formed discontinuously, for example, at a necessary position.

[0065] Since capacitor element assembly 100 tends to be susceptible to stress at its corners, it is more likely to deform at the outer edge than at the center of anode plate 11. Therefore, it is preferable to form more slits 40A at the outer edge of anode plate 11.

[0066] Alternatively, the slit 40B may be formed in the lower portion of the external electrode layer 50. Figure 6 In FIG. 5 , the slit 40B formed in the lower portion of the external electrode layer 50 is indicated by a dotted line.

[0067] When capacitor element assembly 100 includes external electrode layers 50 of different areas, more slits 40C are preferably formed in external electrode layer 50 with a larger area. In this case, more slits 40C may be formed in a region that is easily affected by stress within the surface of the effective capacitance portion.

[0068] By cutting such capacitor element assembly 100 , capacitor elements having slits are obtained.

[0069] According to the above, in the capacitor element of the present invention, the slit may also be provided at a position where the distance from the outer edge of the anode plate is closer than the distance from the central portion of the anode plate. When a plurality of slits are provided on the surface of the sealing layer, it is sufficient that at least one slit is provided at a position where the distance from the outer edge of the anode plate is closer than the distance from the central portion of the anode plate. On the other hand, when a slit is provided on the surface of the sealing layer, it is sufficient that the slit is provided at a position where the distance from the outer edge of the anode plate is closer than the distance from the central portion of the anode plate.

[0070] In the capacitor element of the present invention, the slit may also be provided at a position where the distance from the external electrode layer with a relatively large area is closer than the distance from the external electrode layer with a relatively small area. When a plurality of slits are provided on the surface of the sealing layer, it is sufficient that at least one slit is provided at a position where the distance from the external electrode layer with a relatively large area is closer than the distance from the external electrode layer with a relatively small area. On the other hand, when a slit is provided on the surface of the sealing layer, it is sufficient that the slit is provided at a position where the distance from the external electrode layer with a relatively large area is closer than the distance from the external electrode layer with a relatively small area.

[0071] For example, the external electrode layer with a relatively large area can be either the first external electrode layer electrically connected to the anode plate or the second external electrode layer electrically connected to the cathode layer. Similarly, the external electrode layer with a relatively small area can be either the first external electrode layer electrically connected to the anode plate or the second external electrode layer electrically connected to the cathode layer. In this case, the combination of the external electrode layer with a relatively large area and the external electrode layer with a relatively small area is a combination of the first external electrode layer and the first external electrode layer, a combination of the first external electrode layer and the second external electrode layer, a combination of the second external electrode layer and the first external electrode layer, or a combination of the second external electrode layer and the second external electrode layer.

[0072] Hereinafter, the detailed structures of capacitor elements 1 , 1A, and 1B will be described.

[0073] As the plane shape of the capacitor part 10 when viewed from the thickness direction, for example, a rectangle (square or rectangular), a quadrilateral other than a rectangle, a triangle, a pentagon, a hexagon or other polygon, a circle, an ellipse, a shape formed by combining these shapes, etc. In addition, the plane shape of the capacitor part 10 may also be an L-shape, a C-shape (Japanese コ-shape), a step shape, etc.

[0074] Preferably, the anode plate 11 is formed of a so-called valve metal that exhibits a valve action. Examples of the valve metal include metal monomers such as aluminum, tantalum, niobium, titanium, and zirconium, or alloys containing at least one of these metals. Among them, aluminum or an aluminum alloy is preferred.

[0075] The shape of the anode plate 11 is preferably a flat plate, and more preferably a foil. Thus, in this specification, "plate-like" also includes "foil-like".

[0076] The anode plate 11 only needs to have the porous portion 11B on at least one main surface of the core 11A. That is, the anode plate 11 may have the porous portion 11B on only one main surface of the core 11A, or may have the porous portion 11B on both main surfaces of the core 11A. The porous portion 11B is preferably a porous layer formed on the surface of the core 11A, and more preferably an etching layer.

[0077] The thickness of the anode plate 11 before etching is preferably 60 μm or more and 200 μm or less. The thickness of the core 11A that is not etched after etching is preferably 15 μm or more and 70 μm or less. The thickness of the porous portion 11B is designed to match the required withstand voltage and electrostatic capacitance, but preferably, the total thickness of the porous portions 11B on both sides of the core 11A is 10 μm or more and 180 μm or less.

[0078] The pore size of the porous portion 11B is preferably 10 nm or more and 600 nm or less. The pore size of the porous portion 11B refers to the median diameter D50 measured by a mercury porosimeter. The pore size of the porous portion 11B can be controlled by adjusting various conditions during etching, for example.

[0079] The dielectric layer 13 provided on the surface of the porous portion 11B is porous reflecting the surface state of the porous portion 11B and has a fine concavoconvex surface shape. Preferably, the dielectric layer 13 is composed of an oxide film of the above-mentioned valve-acting metal. For example, when an aluminum foil is used as the anode plate 11, the surface of the aluminum foil is subjected to an anodic oxidation treatment (also called chemical conversion treatment) in an aqueous solution containing ammonium adipate or the like, so that the dielectric layer 13 composed of an oxide film can be formed.

[0080] The thickness of the dielectric layer 13 is designed to match the required withstand voltage and electrostatic capacitance, but is preferably not less than 10 nm and not more than 100 nm.

[0081] In the case where the cathode layer 12 includes a solid electrolyte layer 12A, as a material constituting the solid electrolyte layer 12A, for example, conductive polymers such as polypyrroles, polythiophenes, and polyanilines can be cited. Among them, polythiophenes are preferred, and poly (3,4-ethylenedioxythiophene) called PEDOT is particularly preferred. In addition, the above-mentioned conductive polymer may also include a dopant such as polystyrene sulfonic acid (PSS). In addition, it is preferred that the solid electrolyte layer 12A includes an inner layer that fills the pores (recesses) of the dielectric layer 13 and an outer layer that covers the dielectric layer 13.

[0082] The thickness of solid electrolyte layer 12A from the surface of porous portion 11B is preferably 2 μm or more and 20 μm or less.

[0083] 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 solution containing a monomer such as 3,4-ethylenedioxythiophene, or by a method of applying a dispersion of a polymer such as poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 13 and drying it.

[0084] 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 coating, or inkjet printing.

[0085] When cathode layer 12 includes conductor layer 12B, conductor layer 12B includes at least one of a conductive resin layer and a metal layer. Conductor layer 12B may be only a conductive resin layer or only a metal layer. Preferably, conductor layer 12B covers the entire surface of solid electrolyte layer 12A.

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

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

[0088] The conductor layer 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.

[0089] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer 12A to the copper layer. The carbon layer can be formed in a predetermined area by applying carbon paste to the surface of the solid electrolyte layer 12A by sponge transfer, screen printing, dispenser coating, inkjet printing, etc. In addition, it is preferred that the carbon layer is laminated with the copper layer of the next process in a sticky state before drying. The thickness of the carbon layer is preferably 2 μm or more and 20 μm or less.

[0090] The copper layer can be formed in a predetermined region 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.

[0091] The sealing layer 30 is made of an insulating material. In this case, it is preferable that the sealing layer 30 is made of an insulating resin.

[0092] Examples of the insulating resin constituting the sealing layer 30 include epoxy resin and phenol resin.

[0093] Preferably, the sealing layer 30 further contains a filler.

[0094] Examples of the filler contained in the sealing layer 30 include inorganic fillers such as silica particles and alumina particles.

[0095] A layer such as a stress relaxation layer or a moisture-proof film may be provided between the capacitor unit 10 and the sealing layer 30 .

[0096] Preferably, the through-hole conductor 70 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 .

[0097] The first through-hole conductor 71 penetrates the capacitor portion 10 and the sealing layer 30 in the thickness direction.

[0098] The first through-hole conductor 71 only needs to be provided on the inner wall surface of the first through-hole 81 that penetrates the capacitor unit 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 throughout the first through-hole 81.

[0099] Preferably, the first through-hole conductor 71 is electrically connected to the anode plate 11 at the inner wall surface of the first through-hole 81. More specifically, preferably, the first through-hole conductor 71 is electrically connected to the end surface of the anode plate 11 that is opposite to the inner wall surface of the first through-hole 81 in the planar direction. Thus, the anode plate 11 is electrically led out to the outside via the first through-hole conductor 71.

[0100] Preferably, the core 11A and the porous portion 11B are exposed on the end surface of the anode plate 11 and are electrically connected to the first through-hole conductor 71. In this case, the porous portion 11B is electrically connected to the first through-hole conductor 71 in addition to the core 11A.

[0101] Preferably, when viewed in the thickness direction, the first through-hole conductor 71 is electrically connected to the anode plate 11 over the entire circumference 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 easily reduced, so the ESR is easily reduced.

[0102] The first through-hole conductor 71 is formed, for example, as follows. First, a first through-hole 81 is formed that penetrates the capacitor portion 10 and the sealing layer 30 in the thickness direction by drilling, laser processing, etc. Then, the first through-hole conductor 71 is formed by metallizing the inner wall surface of the first through-hole 81 with a metal material containing a low-resistance metal such as copper, gold, or silver. When forming the first through-hole conductor 71, for example, the inner wall surface of the first through-hole 81 is metallized by electroless copper plating, electrolytic copper plating, etc., so that processing becomes easy. In addition, as for the method of forming the first through-hole conductor 71, in addition to the method of metallizing the inner wall surface of the first through-hole 81, a method of filling the first through-hole 81 with a metal material, a composite material of metal and resin, etc. may also be used.

[0103] In the planar direction, an anode connection layer may be provided 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.

[0104] The anode connection layer is provided between the anode plate 11 and the first through-hole conductor 71 in the planar direction, and the anode connection layer 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. If the anode connection layer functions as a barrier layer for the anode plate 11, the dissolution of the anode plate 11 generated during the treatment with a chemical solution for forming the external electrode layer 50 (for example, the first external electrode layer 51) is suppressed, and the penetration of the chemical solution into the capacitor portion 10 is further suppressed, so that the reliability is easily improved.

[0105] Preferably, the anode connection layer includes a layer containing nickel as a main component. In this case, damage to the metal (eg, aluminum) constituting the anode plate 11 is reduced, so the barrier property of the anode connection layer to the anode plate 11 is easily improved.

[0106] Furthermore, in the planar direction, the anode connection layer may not 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 .

[0107] When the first through-hole conductor 71 is provided only on the inner wall surface of the first through-hole 81, a resin-filled portion filled with a resin material may be provided in the first through-hole 81. In this case, the resin-filled portion is provided in the space surrounded by the first through-hole conductor 71 in the first through-hole 81. If the space in the first through-hole 81 is eliminated by providing the resin-filled portion, the occurrence of delamination of the first through-hole conductor 71 is suppressed.

[0108] The first external electrode layer 51 is electrically connected to the anode plate 11. Figure 1In the example shown, the first external electrode layer 51 is provided on the surface of the first through-hole conductor 71 and functions as a connection terminal of the capacitor unit 10. Figure 1 In the illustrated example, 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 .

[0109] Examples of the constituent material of the first external electrode layer 51 include metal materials containing low-resistance metals such as silver, gold, and copper. In this case, the first external electrode layer 51 is formed by plating the surface of the first through-hole conductor 71, for example.

[0110] In order to improve the close fit between the first external electrode layer 51 and other components, here, in order to improve the close fit between the first external electrode layer 51 and the first through-hole conductor 71, as the constituent material of the first external electrode layer 51, 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 be used.

[0111] The second through-hole conductor 72 penetrates the capacitor portion 10 and the sealing layer 30 in the thickness direction.

[0112] Second through-hole conductor 72 may be provided at least on the inner wall surface of second through-hole 82 penetrating capacitor unit 10 and sealing layer 30 in the thickness direction. Second through-hole conductor 72 may be provided only on the inner wall surface of second through-hole 82 or throughout the entire interior of second through-hole 82.

[0113] The second through-hole conductor 72 is formed, for example, as follows. First, a through-hole is formed that penetrates the capacitor portion 10 in the thickness direction by drilling, laser processing, etc. Next, an insulating material is filled into the through-hole. The second through-hole 82 is formed by drilling, laser processing, etc. on the portion filled with the insulating material. 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 exists between the inner wall surface of the through-hole formed previously and the inner wall surface of the second through-hole 82 in the plane direction. Thereafter, the second through-hole conductor 72 is formed by metalizing the inner wall surface of the second through-hole 82 with a metal material containing a low-resistance metal such as copper, gold, and silver. When forming the second through-hole conductor 72, for example, the inner wall surface of the second through-hole 82 is metalized by using a non-electrolytic copper plating process, an electrolytic copper plating process, etc., so that processing becomes easy. In addition, the second through-hole conductor 72 may be formed by filling the second through-hole 82 with a metal material, a composite material of metal and resin, or the like, other than metalizing the inner wall surface of the second through-hole 82 .

[0114] 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 in the second through-hole 82. If the space in the second through-hole 82 is eliminated by providing the resin-filled portion, the delamination of the second through-hole conductor 72 is suppressed.

[0115] The second external electrode layer 52 is electrically connected to the cathode layer 12. Figure 1 In the illustrated example, 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 unit 10 .

[0116] Examples of the constituent material of the second external electrode layer 52 include metal materials containing low-resistance metals such as silver, gold, and copper. In this case, the second external electrode layer 52 is formed by plating the surface of the second through-hole conductor 72, for example.

[0117] In order to improve the close fit between the second external electrode layer 52 and other components, here, in order to improve the close fit between the second external electrode layer 52 and the second through-hole conductor 72, as the constituent material of the second external electrode layer 52, 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 be used.

[0118] It is preferable that the constituent materials of the first external electrode layer 51 and the second external electrode layer 52 are the same in at least the type, but they may be different from each other.

[0119] exist Figure 1 In the example shown, 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 are provided in each of the plurality of capacitor units 10, but at least one of the first external electrode layer 51 and the second external electrode layer 52 may be provided in common in the plurality of capacitor units 10.

[0120] exist Figure 1 In the illustrated example, 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 may be provided on only one main surface of the sealing layer 30 .

[0121] exist Figure 1 Although not shown in the figure, the through-hole conductor 70 may include a third through-hole conductor that is not electrically connected to the anode plate 11 and the cathode layer 12 .

[0122] 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 .

[0123] Examples of the constituent material of via conductor 90 include metal materials containing a low-resistance metal such as silver, gold, or copper.

[0124] Via conductor 90 is formed, for example, by plating the inner wall surface of a through hole penetrating sealing layer 30 in the thickness direction with the above-mentioned metal material or by filling the through hole with a conductive paste and then performing a heat treatment.

[0125] exist Figure 1 In the illustrated example, 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 .

[0126] exist Figure 1 In the illustrated example, the second external electrode layer 52 is electrically connected to the cathode layer 12 through the via conductor 90 , and functions as a connection terminal for the cathode layer 12 .

[0127] When the through-hole conductor 70 is provided inside the sealing layer 30 , the capacitor unit 10 preferably further includes a shielding layer 35 provided around the through-hole conductor 70 on at least one main surface of the anode plate 11 .

[0128] exist Figure 1 and Figure 2A In the example shown, a shielding layer 35 is provided between the first through-hole conductor 71 and the cathode layer 12. Figure 1 and Figure 2A In the illustrated example, an insulating material such as a sealing layer 30 is filled between the second through-hole conductor 72 and the capacitor portion 10 , and a shielding layer 35 is provided between the insulating material and the cathode layer 12 .

[0129] exist Figure 1 and Figure 2A Although not shown in the figure, the capacitor unit 10 may further include a shielding layer provided in at least one main surface of the anode plate 11 so as to surround the cathode layer 12. By surrounding the cathode layer 12 with the shielding layer, insulation between the anode plate 11 and the cathode layer 12 is ensured, and a short circuit between the two is prevented. The shielding layer may be provided in a manner to surround a portion of the cathode layer 12, but is preferably provided in a manner to surround the entire cathode layer 12.

[0130] The shielding layer such as the shielding layer 35 is made of an insulating material. In this case, it is preferable that the shielding layer is made of an insulating resin.

[0131] Examples of insulating resins constituting shielding layers such as the shielding layer 35 include polyphenylsulfone resins, polyethersulfone resins, cyanate resins, fluororesins (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, etc.), polyimide resins, polyamide-imide resins, epoxy resins, and derivatives or precursors thereof.

[0132] The shielding layer 35 or the like may be made of the same resin as the sealing layer 30. If the shielding layer contains an inorganic filler unlike the sealing layer 30, it may adversely affect the effective capacitance of the capacitor unit 10, so the shielding layer is preferably made of a single resin.

[0133] The shielding layer such as the shielding layer 35 can be formed in a predetermined region by applying a shielding material such as a composition containing an insulating resin to the surface of the porous portion 11B by a method such as sponge transfer, screen printing, dispenser coating, or inkjet printing.

[0134] The shielding layer such as the shielding layer 35 may be formed in the porous portion 11B before or after the dielectric layer 13 is formed.

[0135] The capacitor element of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made to the structure, manufacturing conditions, etc. of the capacitor element within the scope of the present invention.

[0136] In the capacitor element of the present invention, one capacitor portion or a plurality of capacitor portions may be disposed inside the sealing layer.

[0137] In the capacitor element of the present invention, when a plurality of capacitor units are arranged inside the sealing layer, the adjacent capacitor units can be physically disconnected from each other. Thus, the adjacent capacitor units can be electrically disconnected or electrically connected to each other. Preferably, the portions where the adjacent capacitor units are disconnected from each other are filled with insulating materials such as a sealing layer. The intervals between adjacent capacitor units can be constant in the thickness direction or can be reduced in the thickness direction.

[0138] In the capacitor element of the present invention, when a plurality of capacitor units are arranged inside the sealing layer, the plurality of capacitor units can be arranged in a planar direction, can be arranged in a stacked manner in the thickness direction, or can be configured in combination. Multiple capacitor units can be arranged regularly or irregularly. The size and shape of the capacitor element can be the same or partially or completely different. The structures of the capacitor elements are preferably the same, but capacitor elements with different structures can also be included.

[0139] The capacitor element of the present invention can be appropriately used as a constituent material of a composite electronic component. Such a composite electronic component includes, for example: the capacitor element of the present invention; an external electrode layer, which is provided on the surface of the sealing layer of the capacitor element and is electrically connected to the anode plate and cathode layer of the capacitor element respectively; and an electronic component, which is connected to the external electrode layer.

[0140] In the composite electronic component, the electronic component connected to the external electrode layer may be either a passive element or an active element. Both the passive element and the active element may be connected to the external electrode layer, or either the passive element or the active element may be connected to the external electrode layer. In addition, a composite of the passive element and the active element may be connected to the external electrode layer.

[0141] Examples of passive components include inductors, etc. Examples of active components include memories, GPUs (Graphical Processing Units), CPUs (Central Processing Units), MPUs (Micro Processing Units), and PMICs (Power Management ICs).

[0142] The capacitor element of the present invention has a sheet-like shape as a whole. Therefore, in the composite electronic component, the capacitor element can be treated like a mounting substrate, and the electronic component can be mounted on the capacitor element. Moreover, by setting the shape of the electronic component mounted on the capacitor element to be sheet-like, the capacitor element and the electronic component can also be connected in the thickness direction via a through-hole conductor that penetrates each electronic component in the thickness direction. As a result, active components and passive components can be configured as batch modules.

[0143] For example, the capacitor element of the present invention can be electrically connected between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied, thereby forming a switching regulator.

[0144] In the composite electronic component, a circuit layer may be formed on any surface of a capacitor matrix sheet in which a plurality of capacitor elements of the present invention are further arranged, and a passive element or an active element may be connected thereto.

[0145] Alternatively, the capacitor element of the present invention may be placed in a cavity previously provided in a substrate, embedded in a resin, and then a circuit layer may be formed on the resin. Alternatively, other electronic components (passive or active) may be mounted in other cavities of the substrate.

[0146] Alternatively, the capacitor element of the present invention may be mounted on a smooth carrier such as a wafer or glass, and a circuit layer may be formed after the outer layer is formed with a resin, and then connected to a passive element or an active element.

[0147] The following contents are disclosed in this specification.

[0148] <1>

[0149] A capacitor element, wherein:

[0150] The capacitor element comprises:

[0151] A capacitor portion comprising an anode plate, a dielectric layer and a cathode layer, wherein the anode plate has a porous portion on at least one main surface of a core portion, the dielectric layer is provided on a surface of the porous portion, and the cathode layer is provided on a surface of the dielectric layer; and

[0152] a sealing layer that seals the capacitor portion,

[0153] The sealing layer has slits on its surface.

[0154] <2>

[0155] The capacitor element according to <1>, wherein:

[0156] The slit is provided at a position not in contact with the cathode layer.

[0157] <3>

[0158] The capacitor element according to <2>, wherein:

[0159] The capacitor element further includes a first lead conductor, which is provided inside the sealing layer and led out to a surface of the sealing layer so as to be electrically connected to the anode plate.

[0160] The slit is provided at a position not in contact with the cathode layer and the first lead conductor.

[0161] <4>

[0162] The capacitor element according to <3>, wherein:

[0163] The capacitor element further includes a first external electrode layer provided on a surface of the sealing layer in a manner electrically connected to the anode plate via the first lead conductor.

[0164] The slit is provided at a position not in contact with the cathode layer, the first lead conductor, and the first external electrode layer.

[0165] <5>

[0166] The capacitor element according to any one of <2> to <4>, wherein

[0167] The capacitor element further includes 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.

[0168] The slit is provided at a position not in contact with the cathode layer and the second lead conductor.

[0169] <6>

[0170] The capacitor element according to <5>, wherein:

[0171] The capacitor element further includes 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.

[0172] The slit is provided at a position not in contact with the cathode layer, the second lead conductor, and the second external electrode layer.

[0173] <7>

[0174] The capacitor element according to any one of <1> to <6>, wherein:

[0175] The slit is provided at a position closer to an outer edge portion of the anode plate than to a center portion of the anode plate.

[0176] <8>

[0177] The capacitor element according to any one of <1> to <7>, wherein:

[0178] The capacitor element further includes an external electrode layer, which is disposed on the surface of the sealing layer in a manner electrically connected to the anode plate or the cathode layer.

[0179] The external electrode layer includes an external electrode layer with a relatively large area and an external electrode layer with a relatively small area when viewed from above in the thickness direction of the cathode layer.

[0180] The slit is provided at a position closer to the external electrode layer having a relatively large area than to the external electrode layer having a relatively small area.

[0181] <9>

[0182] The capacitor element according to any one of <1> to <8>,

[0183] The cathode layer includes a solid electrolyte layer provided on a surface of the dielectric layer.

[0184] Description of Reference Numerals

[0185] 1. 1A, 1B, capacitor element; 10, capacitor part; 11, anode plate; 11A, core part; 11B, porous part; 12, cathode layer; 12A, solid electrolyte layer; 12B, conductor layer; 13, dielectric layer; 30, sealing layer; 35, shielding layer; 40, 40A, 40B, 40C, slit; 50, external electrode layer; 51, first 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; 100, capacitor element assembly.

Claims

1. A capacitor element, wherein: The capacitor element comprises: A capacitor portion comprising an anode plate, a dielectric layer and a cathode layer, wherein the anode plate has a porous portion on at least one main surface of a core portion, the dielectric layer is provided on a surface of the porous portion, and the cathode layer is provided on a surface of the dielectric layer; and a sealing layer that seals the capacitor portion, A slit is provided on the surface of the sealing layer.

2. The capacitor element according to claim 1, wherein The slit is provided at a position not in contact with the cathode layer.

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

4. The capacitor element according to claim 3, wherein: The capacitor element further includes 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 slit is provided at a position that does not contact the cathode layer, the first lead conductor, and the first external electrode layer.

5. The capacitor element according to any one of claims 2 to 4, wherein The capacitor element further includes 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 slit is provided at a position not in contact with the cathode layer and the second lead conductor.

6. The capacitor element according to claim 5, wherein The capacitor element further includes 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 slit is provided at a position not in contact with the cathode layer, the second lead conductor, and the second external electrode layer.

7. The capacitor element according to any one of claims 1 to 6, wherein The slit is provided at a position closer to an outer edge portion of the anode plate than to a center portion of the anode plate.

8. The capacitor element according to any one of claims 1 to 7, wherein The capacitor element further includes an external electrode layer, which is disposed on the surface of the sealing layer in a manner electrically connected to the anode plate or the cathode layer. The external electrode layer includes an external electrode layer with a relatively large area and an external electrode layer with a relatively small area when viewed from above in the thickness direction of the cathode layer. The slit is provided at a position closer to the external electrode layer having a relatively large area than to the external electrode layer having a relatively small area.

9. The capacitor element according to any one of claims 1 to 8, wherein The cathode layer includes a solid electrolyte layer provided on a surface of the dielectric layer.

Images