Capacitor Element

Abstract

The capacitor element 1 includes a capacitor section 10 including 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, a sealing layer 20 provided to cover the capacitor section 10, a first through-hole conductor 41 provided to penetrate the capacitor section 10 and the sealing layer 20 in the thickness direction so as to be directly electrically connected to the anode plate 11 and both ends of which are extended to the surface of the sealing layer 20, and a cathode layer 12. a second through-hole conductor (42) extending through the capacitor section (10) and the sealing layer (20) in the thickness direction so as to be electrically connected directly to the first through-hole conductor (41), with both ends extended to the surface of the sealing layer (20); a first external electrode layer (31) provided on the surface of the sealing layer (20) so as to be electrically connected to the first through-hole conductor (41); and a second external electrode layer (32) provided on the surface of the sealing layer (20) so as to be electrically connected to the second through-hole conductor (42), wherein at least a portion of the first external electrode layer (31) overlaps the cathode layer (12) in the thickness direction.

Description

[Technical field]

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

[0002] Patent Document 1 describes a solid electrolytic capacitor comprising: a foil-shaped anode having a porous portion on at least one side and through-holes formed at predetermined positions; a dielectric coating formed in the porous portion of the anode; an insulating layer having an opening formed in the dielectric coating; a solid electrolyte layer formed on the dielectric coating at the opening of the insulating layer; a cathode formed on at least a part of the solid electrolyte layer and disposed approximately parallel to the anode; an electrode formed on the insulating layer; and a through-hole electrode that penetrates the insulating layer and the anode to electrically connect the electrode and the anode and / or penetrates the insulating layer and the cathode to electrically connect the electrode and the cathode, at least one of the through-hole electrodes having an elongated hole shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-281111 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the miniaturization and high output of electronic devices, there is a demand for higher density of components. Therefore, embedding capacitor elements in a substrate directly under a power source, such as a GPU (Graphical Processing Unit) substrate, is being considered. In this application, a large current flows, but the heat dissipation of the conventional capacitor element structure is insufficient, and heat may be generated due to the internal resistance of the capacitor element. Such heat generation from various components may have a negative effect on the safety, reliability, performance, life, etc. of the electronic device.

[0005] The solid electrolytic capacitor described in Patent Document 1 also has room for improvement in terms of improving heat dissipation.

[0006] The present invention has been made to solve the above problems, and has an object to provide a capacitor element capable of improving heat dissipation properties. [Means for solving the problem]

[0007] a first through-hole conductor provided to penetrate the capacitor portion and the sealing layer in the thickness direction so as to be electrically connected directly to the anode plate, and both ends of the first through-hole conductor being extended to the surface of the sealing layer; a second through-hole conductor provided to penetrate the capacitor portion and the sealing layer in the thickness direction so as to be electrically connected directly to the cathode layer, and both ends of the first through-hole conductor being extended to the surface of the sealing layer; a first external electrode layer provided on the surface of the sealing layer so as to be electrically connected to the first through-hole conductor; and a second external electrode layer provided on the surface of the sealing layer so as to be electrically connected to the second through-hole conductor, wherein at least a portion of the first external electrode layer overlaps the cathode layer in the thickness direction. Effect of the Invention

[0008] According to the present invention, it is possible to provide a capacitor element capable of improving heat dissipation properties. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a capacitor element according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the capacitor element shown in FIG. 1 taken along line AA. [Diagram 3]FIG. 3 is a plan view of the capacitor element shown in FIG. 1 taken along line BB. [Figure 4] FIG. 4 is a plan view of the capacitor element shown in FIG. 1 taken along line CC. [Diagram 5] FIG. 5 is a cross-sectional view illustrating typically another example of the capacitor element according to the first embodiment of the present invention. [Figure 6-1] FIG. 6-1 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, and shows a step of preparing an anode plate. [Figure 6-2] FIG. 6-2 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming a dielectric layer. [Figure 6-3] FIG. 6-3 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming an insulating mask layer. [Figure 6-4] FIG. 6-4 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming a solid electrolyte layer. [Figure 6-5] FIG. 6-5 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming a first conductive layer. [Figure 6-6] FIG. 6-6 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming a through hole. [Figure 6-7] 6-7 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming an insulating material. [Figure 6-8] 6-8 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of polishing an insulating material. [Figure 6-9] 6-9 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, illustrating a step of forming a second conductive layer. [Figure 6-10] 6-10 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming a sealing layer. [Figure 6-11]6-11 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, illustrating steps of forming the first through hole and the second through hole. [Figure 6-12] 6-12 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, illustrating steps of forming through-hole conductors and external electrode layers. [Figure 7-1] FIG. 7-1 is a schematic cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, and shows a state after the through holes have been formed. [Figure 7-2] FIG. 7-2 is a schematic cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, illustrating a step of forming an insulating material. [Figure 7-3] FIG. 7-3 is a schematic cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, illustrating the step of forming a second conductive layer. [Figure 7-4] FIG. 7-4 is a schematic cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, illustrating a step of forming a sealing layer. [Figure 7-5] FIG. 7-5 is a schematic cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, illustrating a step of forming the first through hole and the second through hole. [Figure 7-6] FIG. 7-6 is a schematic cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1, illustrating the steps of forming through-hole conductors and external electrode layers. [Figure 8] FIG. 8 is a plan view illustrating an example of a capacitor element according to a second embodiment of the present invention. [Figure 9-1] FIG. 9-1 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of preparing an anode plate. [Figure 9-2] FIG. 9-2 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming a dielectric layer. [Figure 9-3] FIG. 9-3 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming an insulating mask layer. [Figure 9-4] FIG. 9-4 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming a solid electrolyte layer. [Figure 9-5] FIG. 9-5 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming a first conductive layer. [Figure 9-6] FIG. 9-6 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing a step of forming a through hole. [Figure 9-7] FIG. 9-7 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming an insulating material. [Figure 9-8] FIG. 9-8 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of polishing an insulating material. [Figure 9-9] FIG. 9-9 is a schematic cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, and shows a step of forming a second conductive layer. [Figure 9-10] 9 and 10 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing a step of forming a sealing layer. [Figure 9-11] 9-11 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, illustrating steps of forming the first through hole and the second through hole. [Figure 9-12] 9-12 are schematic cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, illustrating steps of forming through-hole conductors and external electrode layers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The capacitor element of the present invention will be described below. Note that the present invention is not limited to the following configurations, and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0011] The following embodiments are merely examples, and it goes without saying that partial replacement or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, the description of the matters common to the first embodiment will be omitted, and the differences will be mainly described. In particular, similar effects due to similar configurations will not be mentioned one by one for each embodiment.

[0012] In the following description, unless there is a need to distinguish between the various embodiments, they will simply be referred to as "the capacitor element of the present invention."

[0013] In this specification, terms indicating the relationship between elements (e.g., "vertical," "parallel," "orthogonal," etc.) and terms indicating the shapes of elements are not intended to be used in a strict sense, but are intended to include a range of substantial equivalence, for example, a difference of a few percent.

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and scale may differ from those of the actual product.

[0015] [First embodiment] Fig. 1 is a cross-sectional view diagrammatically illustrating an example of a capacitor element according to a first embodiment of the present invention. Fig. 2 is a plan view taken along line AA of the capacitor element shown in Fig. 1. Fig. 3 is a plan view taken along line BB of the capacitor element shown in Fig. 1. Fig. 4 is a plan view taken along line CC of the capacitor element shown in Fig. 1. Fig. 1 is a cross-sectional view diagrammatically illustrating the capacitor element shown in Figs. 2 to 4, taken along line DD.

[0016] The capacitor element 1 shown in Figures 1 to 4 comprises a capacitor portion 10, a sealing layer 20 provided to cover the capacitor portion 10, a through-hole conductor 40 provided to penetrate the capacitor portion 10 and the sealing layer 20 in the thickness direction and with both ends extended to the surface of the sealing layer 20, and an external electrode layer 30 provided on the surface of the sealing layer 20 so as to be electrically connected to the through-hole conductor 40.

[0017] 1 to 4, one capacitor portion 10 is disposed inside sealing layer 20. The number of capacitor portions 10 disposed inside sealing layer 20 is not particularly limited, and may be one or more.

[0018] The capacitor section 10 includes an anode plate 11 having a porous portion 11B on at least one main surface of a core portion 11A, a dielectric layer 13 provided on the surface of the porous portion 11B, and a cathode layer 12 provided on the surface of the dielectric layer 13. This configures the capacitor section 10 as an electrolytic capacitor. In the example shown in Fig. 1, the anode plate 11 has the porous portion 11B on both main surfaces of the core portion 11A, but the porous portion 11B may be provided on only one of the main surfaces of the core portion 11A.

[0019] Cathode layer 12 includes, for example, solid electrolyte layer 12A provided on the surface of dielectric layer 13. When cathode layer 12 includes solid electrolyte layer 12A, capacitor section 10 constitutes a solid electrolytic capacitor.

[0020] 1, sealing layer 20 is preferably provided on both opposing main surfaces in the thickness direction of capacitor section 10. Capacitor section 10 is protected by sealing layer 20.

[0021] The sealing layer 20 may be composed of only one layer, or may be composed of two or more layers. When the sealing layer 20 is composed of two or more layers, the materials constituting each layer may be the same or different.

[0022] Sealing layer 20 is formed so as to seal capacitor portion 10 by, for example, a method of thermocompression bonding an insulating resin sheet, a method of applying an insulating resin paste and then thermally curing it, or the like.

[0023] In the example shown in FIG. 1, the through-hole conductor 40 includes a first through-hole conductor 41 electrically connected to the anode plate 11 and a second through-hole conductor 42 electrically connected to the cathode layer 12 .

[0024] It is sufficient that the first through-hole conductor 41 is provided on at least the inner wall surface of the first through hole 51 that penetrates the capacitor portion 10 and the sealing layer 20 in the thickness direction. The first through-hole conductor 41 may be provided only on the inner wall surface of the first through hole 51, or may be provided throughout the entire interior of the first through hole 51.

[0025] As shown in FIG. 3, in a plan view from the thickness direction, one first through-hole conductor 41 may be provided inside the cathode layer 12, or two or more first through-hole conductors 41 may be provided.

[0026] The second through-hole conductor 42 may be provided on at least the inner wall surface of the second through hole 52 that penetrates the capacitor portion 10 and the sealing layer 20 in the thickness direction. The second through-hole conductor 42 may be provided only on the inner wall surface of the second through hole 52, or may be provided throughout the entire interior of the second through hole 52.

[0027] As shown in FIG. 1, it is preferable that an insulating material 22 is filled between the second through-hole conductor 42 and the capacitor section 10 (particularly the anode plate 11).

[0028] As shown in FIG. 3, in a plan view from the thickness direction, one second through-hole conductor 42 may be provided inside the cathode layer 12, or two or more second through-hole conductors 42 may be provided.

[0029] Although not shown in FIGS. 1 to 4, through-hole conductors 40 may include a third through-hole conductor that is not electrically connected to anode plate 11 and cathode layer 12.

[0030] The external electrode layer 30 includes a first external electrode layer 31 electrically connected to the first through-hole conductor 41 and the anode plate 11, and a second external electrode layer 32 electrically connected to the second through-hole conductor 42 and the cathode layer 12.

[0031] One first external electrode layer 31 may be provided for one capacitor section 10, or a plurality of first external electrode layers 31 may be provided. Similarly, one second external electrode layer 32 may be provided for one capacitor section 10, or a plurality of second external electrode layers 32 may be provided. The number of first external electrode layers 31 for one capacitor section 10 may be the same as the number of second external electrode layers 32, or may be different.

[0032] The planar shape of the external electrode layer 30 when viewed in the thickness direction is not particularly limited, and examples thereof include a rectangle (square or oblong), a quadrangle other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, an ellipse, a combination of these, etc. The planar shape of the external electrode layer 30 may also be an L-shape, a C-shape, a step shape, etc.

[0033] The planar shape of the first external electrode layer 31 when viewed from the thickness direction may be the same as or different from the planar shape of the second external electrode layer 32 when viewed from the thickness direction.

[0034] The cathode layer 12 may be drawn out by an internal via conductor as in the example shown in FIG. 5 described later, but in the example shown in FIG. 1, the second through-hole conductor 42 is electrically connected directly to the cathode layer 12, and the cathode layer 12 is drawn out by the second through-hole conductor 42. In this way, the second through-hole conductor 42 is electrically connected directly to the cathode layer 12, so that the heat dissipation path, i.e., the heat dissipation area, can be increased compared to the case where the cathode layer 12 is drawn out only by the internal via conductor. In the example shown in FIG. 1, at least a part of the first external electrode layer 31 overlaps the cathode layer 12 in the thickness direction, which also increases the heat dissipation area. As a result, the heat dissipation property of the capacitor element 1 can be improved. As a result, the temperature rise due to heat generation of the capacitor element 1 can be suppressed.

[0035] In addition, since the second through-hole conductor 42 is electrically connected directly to the cathode layer 12, the second through-hole conductor 42 and the cathode layer 12 are in direct contact with each other without going through a resin portion, which is a different material, and therefore the rigidity of the capacitor element 1 can be improved. Similarly, since at least a part of the first external electrode layer 31 overlaps with the cathode layer 12 in the thickness direction, the area of ​​the first external electrode layer 31 can be increased, and therefore the rigidity of the capacitor element 1 can be improved. When the cathode layer 12 is not drawn out by an internal via conductor as in the example shown in FIG. 1, the capacitor element 1 can be made thin, but there is a possibility that the capacitor element 1 may warp. However, since the first external electrode layer 31 overlaps with the cathode layer 12, the rigidity of the capacitor element 1 is improved and the occurrence of such warping can also be suppressed.

[0036] Furthermore, since at least a portion of the first external electrode layer 31 overlaps the cathode layer 12 in the thickness direction, the area of ​​the first external electrode layer 31 can be increased, thereby preventing moisture, oxygen, etc. from entering the capacitor section 10 from the outside.

[0037] In this specification, the through-hole conductor being electrically connected directly to a conductive layer such as a cathode layer or an anode plate means excluding the case where the through-hole conductor only has a structure (connection path) electrically connected to the conductive layer via a via conductor or an external electrode layer. In this case, the through-hole conductor is electrically connected to the conductive layer on the inner wall surface of the through hole, that is, the side wall portion of the through-hole conductor is electrically connected to the conductive layer. In the example shown in FIG. 1, the second through-hole conductor 42 is electrically connected to the cathode layer 12 on the inner wall surface of the second through hole 52.

[0038] In addition, in the example shown in Figure 1, the first through-hole conductor 41 is also directly electrically connected to the anode plate 11, and the first through-hole conductor 41 is electrically connected to the anode plate 11 on the inner wall surface of the first through hole 51.

[0039] As shown in FIG. 1, only a part of the first external electrode layer 31 may overlap with the cathode layer 12 in the thickness direction. The ratio of the area of the portion overlapping with the cathode layer 12 in the thickness direction to the total area of the first external electrode layer 31 is not particularly limited, but is preferably 50% or more and 90% or less, and more preferably 60% or more and 80% or less.

[0040] Also, as shown in FIG. 1, the cathode layer 12 may include a copper layer 12Cu, the first external electrode layer 31 may include a copper layer 31Cu, and the second external electrode layer 32 may include a copper layer 32Cu. In this case, if the thickness of the copper layer 12Cu of the cathode layer 12 is d1, the thickness of the copper layer 31Cu of the first external electrode layer 31 is d2, and the thickness of the copper layer 32Cu of the second external electrode layer 32 is d3, it is preferable to satisfy d1≧d2 and d1≧d3. Thereby, current concentration in the cathode layer 12 can be suppressed, and heat generation can be suppressed. In addition, the volume of the copper layer 12Cu of the cathode layer 12 can be increased to promote heat diffusion, and damage to the capacitor portion 10 can be suppressed.

[0041] The ratio of d1 to d2, that is, d1 / d2, preferably satisfies 1 < d1 / d2 < 3, and more preferably satisfies 1.5 < d1 / d2 < 2.5. The ratio of d1 to d3, that is, d1 / d3, preferably satisfies 1 < d1 / d3 < 3, and more preferably satisfies 1.5 < d1 / d3 < 2.5.

[0042] In the example shown in FIG. 1, the copper layer 12Cu is the second conductor layer 12C of the cathode layer 12 described later, the copper layer 31Cu is the first external electrode layer 31, and the copper layer 32Cu is the second external electrode layer 32.

[0043] When the cathode layer 12 is composed of a plurality of layers including the copper layer 12Cu, the copper layer 12Cu is preferably one or more layers closest to the first external electrode layer 31 and the second external electrode layer 32 among the plurality of layers constituting the cathode layer 12.

[0044] Furthermore, when the first external electrode layer 31 is composed of multiple layers including the copper layer 31Cu, the copper layer 31Cu may be any one of the multiple layers constituting the cathode layer 12. The same applies to the second external electrode layer 32.

[0045] From the viewpoint of heat dissipation, it is preferable to match the volumes of the anode and cathode of capacitor element 1. Therefore, based on a comparison between the volume of anode plate 11 and the volume of cathode layer 12, a preferable area ratio between first external electrode layer 31 and second external electrode layer 32 will be described.

[0046] The thickness of the core 11A of the anode plate 11 is, for example, 40 μm or more and 60 μm or less, and the area of ​​the core 11A of the anode plate 11 is assumed to be approximately 100% in the plane along the line AA in Fig. 1 shown in Fig. 2. Furthermore, on both main surfaces of the anode plate 11, the thickness of the copper layer 12Cu of each cathode layer 12 is, for example, approximately 30 μm, and the area of ​​the copper layer 12Cu is assumed to be approximately 100% in the plane along the line BB in Fig. 1 shown in Fig. 3.

[0047] Here, the thermal conductivity of copper is approximately 1.7 times that of aluminum, which is a suitable material for the anode plate 11, and as described above, the area of ​​the core 11A of the anode plate 11 and the area of ​​the copper layer 12Cu of each cathode layer 12 on both sides of the core 11A are approximately the same. Therefore, when the total thickness of the copper layer 12Cu of the cathode layer 12 on both sides of the core 11A is 60 μm, the thickness required for the core 11A of the anode plate 11 is 60×1.7=102 μm. Therefore, the cathode has a better thermal conductivity (heat dissipation) than the anode. In addition, when an internal via conductor is connected to the cathode layer 12 as in the second embodiment described later, the cathode has a better thermal conductivity (heat dissipation).

[0048] From the above, from the viewpoint of correcting the imbalance in the volumes of the internal anodes and cathodes and further improving heat dissipation, it is preferable to satisfy S1>S2, where S1 is the area of ​​the first external electrode layer 31 electrically connected to the anode plate 11 and S2 is the area of ​​the second external electrode layer 32 electrically connected to the cathode layer 12. Furthermore, by satisfying S1>S2, undulations (waviness) of the substrate on which the capacitor element 1 is mounted can also be suppressed.

[0049] In the present specification, when simply referring to "area", it means the area in a plan view from the thickness direction.

[0050] Also, as shown in FIG. 1, when the first external electrode layer 31 and the second external electrode layer 32 are respectively provided on both main surface sides of the capacitor portion 10, it is more preferable that S1 > S2 is satisfied on each main surface side of the capacitor portion 10, but S1 > S2 may also be satisfied on at least one main surface side of the capacitor portion 10.

[0051] The ratio of S1 to S2, that is, S1 / S2, preferably satisfies 1 < S1 / S2 < 3.5, and more preferably satisfies 1.5 < S1 / S2 < 3.

[0052] Note that the comparison such as S1 > S2 or S1 / S2 is made based on the areas of the first external electrode layer 31 and the second external electrode layer 32 provided on the same main surface side of the capacitor portion 10.

[0053] The cathode layer 12 preferably includes a solid electrolyte layer 12A provided on the surface of the dielectric layer 13, a first conductor layer 12B provided on the surface of the solid electrolyte layer 12A, and a second conductor layer 12C provided on the surface of the first conductor layer 12B so as to be electrically directly connected to the second through-hole conductor 42. Thereby, the second through-hole conductor 42 can be easily electrically directly connected to the cathode layer 12.

[0054] Also, in the example shown in FIG. 1, similar elements (members) are arranged on both main surface sides of the core portion 11A of the anode plate 11. This can also suppress the occurrence of warping of the capacitor element 1. In addition, the capacitance of the capacitor portion 10 can be improved.

[0055] Moreover, it is preferable that the areas of the first through-hole conductors 41 and the second through-hole conductors 42 provided in the capacitor element 1 are the same, and it is more preferable that the numbers of the first through-hole conductors 41 and the second through-hole conductors 42 provided in the capacitor element 1 are the same. This makes it possible to make the heat dissipation properties of the capacitor element 1 uniform.

[0056] Furthermore, it is preferable that the through-hole conductors 40 (i.e., the first through-hole conductor 41 and the second through-hole conductor 42 are not distinguished from each other) provided in the capacitor element 1 are arranged at an equal pitch. This also makes it possible to uniformize the heat dissipation of the capacitor element 1. It is also possible to prevent the occurrence of peeling called delamination, such as peeling of the cathode layer from the anode plate.

[0057] It is preferable that the capacitor section 10 further includes an insulating mask layer 25 provided around the through-hole conductor 40 on at least one of the main surfaces of the anode plate 11 .

[0058] 1, an insulating mask layer 25 is provided between first through-hole conductor 41 and cathode layer 12. Also, in the example shown in Fig. 1, an insulating material 22 is filled between second through-hole conductor 42 and capacitor portion 10 (particularly anode plate 11), and insulating mask layer 25 is provided between insulating material 22 and cathode layer 12 (e.g., solid electrolyte layer 12A).

[0059] The capacitor section 10 may further include an insulating mask layer 25 provided on at least one main surface of the anode plate 11 so as to surround the periphery of the cathode layer 12 (e.g., the solid electrolyte layer 12A; the same applies hereinafter in this paragraph). By surrounding the periphery of the cathode layer 12 with the insulating mask layer 25, insulation between the anode plate 11 and the cathode layer 12 is ensured, and a short circuit between them is prevented. The insulating mask layer 25 may be provided so as to surround a part of the periphery of the cathode layer 12, but is preferably provided so as to surround the entire periphery of the cathode layer 12.

[0060] FIG. 5 is a cross-sectional view illustrating typically another example of the capacitor element according to the first embodiment of the present invention.

[0061] The capacitor element 2 shown in Fig. 5 further includes an internal via conductor 60 that is provided so as to penetrate the sealing layer 20 in the thickness direction, with one end electrically connected to the second external electrode layer 32 and the other end electrically connected to the cathode layer 12. By providing such an internal via conductor 60, it is possible to further improve heat dissipation. In addition, it is possible to improve adhesion between layers and suppress the occurrence of delamination.

[0062] In the example shown in FIG. 5, one end of the internal via conductor 60 is extended to the surface of the sealing layer 20 .

[0063] Furthermore, the internal via conductor 60 is electrically connected to the cathode layer 12. As a result, the cathode layer 12 is electrically led out to the outside of the sealing layer 20 via the internal via conductor 60 and the second through-hole conductor 42, and can be electrically connected to the outside of the sealing layer 20. The number of internal via conductors 60 electrically connected to the cathode layer 12 may be one, or two or more.

[0064] 5, the capacitor element 2 may include an internal via conductor 60 electrically connected to the anode plate 11. In this case, the anode plate 11 is electrically led out to the outside of the sealing layer 20 through the internal via conductor 60, and can be electrically connected to the outside of the sealing layer 20. The number of internal via conductors 60 electrically connected to the anode plate 11 may be one, or two or more.

[0065] The detailed configuration of the capacitor elements 1, 2, etc. will be described below.

[0066] Examples of the planar shape of the capacitor section 10 when viewed in the thickness direction include a rectangle (square or oblong), a quadrangle other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, an ellipse, a combination of these, etc. The planar shape of the capacitor section 10 may also be an L-shape, a C-shape, a step shape, etc.

[0067] The anode plate 11 is preferably made of a valve metal that exhibits a so-called valve action. Examples of the valve metal include simple metals such as aluminum, tantalum, niobium, titanium, and zirconium, and alloys containing at least one of these metals. Among these, aluminum or an aluminum alloy is preferable.

[0068] The shape of the anode plate 11 is preferably a flat plate, and more preferably a foil. Thus, in this specification, the term "plate-like" includes "foil-like".

[0069] The anode plate 11 may have the porous portion 11B on at least one main surface of the core portion 11A. That is, the anode plate 11 may have the porous portion 11B on only one main surface of the core portion 11A as in a second embodiment described later, or may have the porous portion 11B on both main surfaces of the core portion 11A. The porous portion 11B is preferably a porous layer formed on the surface of the core portion 11A, and more preferably an etched layer.

[0070] The thickness of the anode plate 11 before the etching process is preferably 60 μm or more and 200 μm or less. The thickness of the core portion 11A that is not etched after the etching process is preferably 15 μm or more and 70 μm or less. The thickness of the porous portion 11B is designed according to the required withstand voltage and electrostatic capacitance, but it is preferably 10 μm or more and 180 μm or less in total for the porous portions 11B on both sides of the core portion 11A.

[0071] 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 means the median size D50 measured by a mercury porosimeter. The pore size of the porous portion 11B can be controlled by adjusting various conditions in the etching, for example.

[0072] 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 finely uneven surface shape. The dielectric layer 13 is preferably made of an oxide film of the valve metal. For example, when an aluminum foil is used as the anode plate 11, the dielectric layer 13 made of an oxide film can be formed by anodizing the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like (also called chemical conversion treatment).

[0073] The thickness of the dielectric layer 13 is designed according to the required withstand voltage and capacitance, but is preferably 10 nm or more and 100 nm or less.

[0074] When the cathode layer 12 includes the solid electrolyte layer 12A, examples of materials constituting the solid electrolyte layer 12A include conductive polymers such as polypyrroles, polythiophenes, and polyanilines. Among these, polythiophenes are preferred, and poly(3,4-ethylenedioxythiophene), also known as PEDOT, is particularly preferred. The conductive polymer may also include a dopant such as polystyrene sulfonate (PSS). The solid electrolyte layer 12A preferably includes an inner layer that fills the pores (recesses) of the dielectric layer 13, and an outer layer that covers the dielectric layer 13.

[0075] 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.

[0076] The solid electrolyte layer 12A is formed, for example, by a method of forming a polymerized film of poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 13 using a treatment liquid containing a monomer such as 3,4-ethylenedioxythiophene, or a method of applying a dispersion liquid of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer 13 and drying it.

[0077] The solid electrolyte layer 12A can be formed in a predetermined region by applying the above-mentioned treatment liquid or dispersion liquid to the surface of the dielectric layer 13 by a method such as sponge transfer, screen printing, dispenser application, or inkjet printing.

[0078] When the cathode layer 12 includes the first conductive layer 12B and the second conductive layer 12C, the first conductive layer 12B and the second conductive layer 12C each include at least one of a conductive resin layer and a metal layer. The first conductive layer 12B and the second conductive layer 12C may each be only a conductive resin layer or only a metal layer, but the first conductive layer 12B is preferably composed only of a conductive resin layer, and the second conductive layer 12C is preferably composed only of a metal layer. The first conductive layer 12B preferably covers the entire surface of the solid electrolyte layer 12A.

[0079] The conductive resin layer may be, for example, a conductive adhesive layer (conductive paste 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.

[0080] Examples of the metal layer include a metal plating layer and a metal foil layer. The metal layer is preferably made of at least one metal selected from the group consisting of nickel, copper, silver, and alloys containing these metals as main components. The term "main component" refers to the elemental component with the largest weight ratio.

[0081] The first conductive layer 12B includes, for example, a carbon paste layer provided on the surface of the solid electrolyte layer 12A, and a copper paste layer provided on the surface of the carbon paste layer.

[0082] The second conductive layer 12C is made of a copper layer 12Cu, such as a copper plating layer or a copper foil layer.

[0083] When the first conductive layer 12B includes a copper paste layer, the thickness d1 of the copper layer 12Cu of the cathode layer 12 described above is the combined thickness of the copper layer 12Cu of the second conductive layer 12C and the copper paste layer of the first conductive layer 12B.

[0084] The carbon paste layer of the first conductive layer 12B is provided to electrically and mechanically connect the solid electrolyte layer 12A and the copper paste layer of the first conductive layer 12B. The carbon paste layer can be formed in a predetermined area by applying carbon paste to the surface of the solid electrolyte layer 12A by a method such as sponge transfer, screen printing, dispenser application, or inkjet printing. It is preferable that the carbon paste layer is laminated with the copper paste layer in the next process while the carbon paste layer is in a viscous state before drying. The thickness of the carbon paste layer is preferably 2 μm or more and 50 μm or less.

[0085] The copper paste layer of the first conductive layer 12B can be formed in a predetermined region by applying copper paste to the surface of the carbon paste layer by sponge transfer, screen printing, spray application, dispenser application, inkjet printing, etc. The thickness of the copper paste layer is preferably 2 μm or more and 50 μm or less.

[0086] The copper plating layer of the second conductive layer 12C can be formed in a predetermined region by forming a film by electrolytic plating, electroless plating, sputtering, vacuum deposition, etc., and then patterning it by etching (dry or wet). The thickness of the copper plating layer is preferably 2 μm or more and 35 μm or less.

[0087] The copper foil layer of the second conductive layer 12C can be formed in a predetermined region by laminating copper foil that has been previously patterned by etching (dry or wet) in a press, or laminating copper foil in a press and then patterning it by etching (dry or wet). The thickness of the copper foil layer is preferably 3 μm or more and 35 μm or less.

[0088] The sealing layer 20 is made of an insulating material. In this case, the sealing layer 20 is preferably made of an insulating resin.

[0089] Examples of the insulating resin that constitutes the sealing layer 20 include epoxy resin, phenol resin, and the like.

[0090] The sealing layer 20 preferably further contains a filler.

[0091] Examples of the filler contained in the sealing layer 20 include inorganic fillers such as silica particles and alumina particles.

[0092] Between the capacitor section 10 and the sealing layer 20, for example, a stress relaxation layer, a moisture-proof film, or other layer may be provided.

[0093] The insulating mask layer 25 is made of an insulating material, and in this case, the insulating mask layer 25 is preferably made of an insulating resin.

[0094] Examples of insulating resins that form the insulating mask layer 25 include polyphenylsulfone resins, polyethersulfone resins, cyanate ester resins, fluororesins (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymers, etc.), polyimide resins, polyamideimide resins, epoxy resins, and derivatives or precursors thereof.

[0095] Insulating mask layer 25 may be made of the same resin as sealing layer 20. Unlike sealing layer 20, if insulating mask layer 25 contains an inorganic filler, it may adversely affect the effective capacitance portion of capacitor section 10, so insulating mask layer 25 is preferably made of a resin alone.

[0096] The insulating mask layer 25 can be formed in a predetermined area by applying a mask 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 application, inkjet printing, or the like.

[0097] The insulating mask layer 25 may be formed on the porous portion 11B either before or after the dielectric layer 13 is formed.

[0098] The first external electrode layer 31 is electrically connected to the anode plate 11. In the example shown in Fig. 1, the first external electrode layer 31 is provided on the surface of the first through-hole conductor 41, and functions as a connection terminal of the capacitor section 10. In the example shown in Fig. 1, the first external electrode layer 31 is electrically connected to the anode plate 11 via the first through-hole conductor 41, and functions as a connection terminal for the anode plate 11.

[0099] Examples of the constituent material of the first external electrode layer 31 include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the first external electrode layer 31 is formed by, for example, plating the surface of the first through-hole conductor 41.

[0100] In order to improve the adhesion between the first external electrode layer 31 and other components, in this case, between the first external electrode layer 31 and the first through-hole conductor 41, a mixed material (conductive paste material) of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as a constituent material of the first external electrode layer 31.

[0101] The first external electrode layer 31 may include a copper layer 31Cu such as a copper paste layer, a copper plating layer, a copper foil layer, etc. The copper paste layer, copper plating layer, and copper foil layer of the first external electrode layer 31 can be formed in the same manner as the copper paste layer of the first conductive layer 12B, and the copper plating layer and copper foil layer of the second conductive layer 12C.

[0102] The second external electrode layer 32 is electrically connected to the cathode layer 12. In the example shown in Fig. 1, the second external electrode layer 32 is provided on the surface of the second through-hole conductor 42, and functions as a connection terminal for the capacitor section 10. In the example shown in Fig. 1, the second external electrode layer 32 is electrically connected to the cathode layer 12 via the second through-hole conductor 42, and functions as a connection terminal for the cathode layer 12.

[0103] Examples of the constituent material of the second external electrode layer 32 include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the second external electrode layer 32 is formed by, for example, plating the surfaces of the second through-hole conductors 42.

[0104] In order to improve the adhesion between the second external electrode layer 32 and other components, in this case, between the second external electrode layer 32 and the second through-hole conductor 42, a mixed material (conductive paste material) of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as a constituent material of the second external electrode layer 32.

[0105] The second external electrode layer 32 may include a copper layer 32Cu such as a copper paste layer, a copper plating layer, a copper foil layer, etc. The copper paste layer, copper plating layer, and copper foil layer of the second external electrode layer 32 can be formed in the same manner as the copper paste layer of the first conductive layer 12B, and the copper plating layer and copper foil layer of the second conductive layer 12C.

[0106] The constituent materials of the first external electrode layer 31 and the second external electrode layer 32 are preferably the same as each other at least in terms of type, but may be different from each other.

[0107] When multiple capacitor sections 10 are arranged, each of the multiple capacitor sections 10 may be provided with a first external electrode layer 31 electrically connected to the anode plate 11 and a second external electrode layer 32 electrically connected to the cathode layer 12, or at least one of the first external electrode layer 31 and the second external electrode layer 32 may be provided in common among the multiple capacitor sections 10.

[0108] In the example shown in FIG. 1, the first external electrode layer 31 and the second external electrode layer 32 are provided on both main surfaces of the sealing layer 20, but they may be provided on only one of the main surfaces of the sealing layer 20.

[0109] The first through-hole conductor 41 is electrically connected to the anode plate 11 on the inner wall surface of the first through hole 51. More specifically, the first through-hole conductor 41 is preferably electrically connected to the end surface of the anode plate 11 facing the inner wall surface of the first through hole 51 in the planar direction. In this way, the anode plate 11 is electrically led out to the outside via the first through-hole conductor 41.

[0110] It is preferable that the core portion 11A and the porous portion 11B are exposed on the end face of the anode plate 11 that is electrically connected to the first through-hole conductor 41. In this case, the porous portion 11B as well as the core portion 11A are electrically connected to the first through-hole conductor 41.

[0111] 2, when viewed in the thickness direction, the first through-hole conductor 41 is preferably electrically connected to the anode plate 11 over the entire circumference of the first through hole 51. In this case, the number of heat dissipation paths increases, thereby further improving the heat dissipation performance of the capacitor element 1. In addition, the connection resistance between the anode plate 11 and the first through-hole conductor 41 is likely to decrease, which makes it easier to reduce the equivalent series resistance (ESR).

[0112] The first through-hole conductor 41 is formed, for example, as follows. First, a first through hole 51 penetrating the capacitor section 10 and the sealing layer 20 in the thickness direction is formed by performing drilling, laser processing, or the like. Then, the inner wall surface of the first through hole 51 is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, to form the first through-hole conductor 41. When forming the first through-hole conductor 41, for example, the inner wall surface of the first through hole 51 is metallized by electroless copper plating, electrolytic copper plating, or the like, to facilitate processing. Note that the method of forming the first through-hole conductor 41 may be a method of filling the first through hole 51 with a metal material, a composite material of metal and resin, or the like, in addition to a method of metallizing the inner wall surface of the first through hole 51.

[0113] An anode connection layer may be provided between the anode plate 11 and the first through-hole conductor 41 in the planar direction. That is, the anode plate 11 and the first through-hole conductor 41 may be electrically connected via the anode connection layer.

[0114] Since the anode connection layer is provided between the anode plate 11 and the first through-hole conductor 41 in the surface direction, 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. When the anode connection layer functions as a barrier layer for the anode plate 11, dissolution of the anode plate 11 that occurs during chemical treatment for forming the external electrode layer 30 (e.g., the first external electrode layer 31) is suppressed, and thus infiltration of the chemical solution into the capacitor portion 10 is suppressed, which tends to improve reliability.

[0115] The anode connecting layer preferably includes a layer mainly composed of nickel. In this case, damage to the metal (e.g., aluminum) constituting the anode plate 11 is reduced, and the barrier property of the anode connecting layer against the anode plate 11 is easily improved.

[0116] In addition, in the planar direction, an anode connection layer does not have to be provided between the anode plate 11 and the first through-hole conductor 41. In this case, the first through-hole conductor 41 may be directly connected to the end surface of the anode plate 11.

[0117] 1, the first through-hole conductor 41 is provided only on the inner wall surface of the first through hole 51. In this case, the first through hole 51 may be provided with a resin filled portion 91 filled with a resin material. The resin filled portion 91 is provided in the space surrounded by the first through-hole conductor 41 in the first through hole 51. When the space in the first through hole 51 is eliminated by providing the resin filled portion 91, the occurrence of delamination of the first through-hole conductor 41 is suppressed. The resin filled portion 91 may be a conductor or an insulator.

[0118] 1, second through-hole conductor 42 is electrically connected to cathode layer 12, particularly to second conductive layer 12C, on the inner wall surface of second through hole 52. More specifically, second through-hole conductor 42 is preferably electrically connected to an end surface of second conductive layer 12C facing the inner wall surface of second through hole 52 in the planar direction. In this way, cathode layer 12 is electrically led out to the outside via second through-hole conductor 42.

[0119] 3, when viewed in the thickness direction, second through-hole conductor 42 is preferably electrically connected to cathode layer 12, particularly second conductive layer 12C, over the entire circumference of second through hole 52. In this case, the number of heat dissipation paths increases, thereby further improving the heat dissipation performance of capacitor element 1. In addition, the connection resistance between cathode layer 12 and second through-hole conductor 42 is likely to decrease, and therefore the equivalent series resistance (ESR) is likely to decrease.

[0120] The second through-hole conductor 42 is formed, for example, as follows. First, a through hole 53 penetrating the capacitor unit 10 in the thickness direction is formed by drilling, laser processing, or the like. Next, the insulating material 22 is filled into the through hole 53. The portion filled with the insulating material 22 is drilled, laser processing, or the like to form the second through hole 52. At this time, the diameter of the second through hole 52 is made smaller than the diameter of the through hole 53 filled with the insulating material 22, so that the insulating material 22 is present between the inner wall surface of the previously formed through hole 53 and the inner wall surface of the second through hole 52 in the planar direction. Thereafter, the inner wall surface of the second through hole 52 is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, to form the second through-hole conductor 42. When forming the second through-hole conductor 42, for example, the inner wall surface of the second through hole 52 is metallized with electroless copper plating, electrolytic copper plating, or the like to facilitate processing. As for the method of forming the second through-hole conductor 42, in addition to the method of metallizing the inner wall surface of the second through hole 52, a method of filling the second through hole 52 with a metal material, a composite material of metal and resin, etc. may also be used.

[0121] The insulating material 22 is preferably made of an insulating resin. Examples of the insulating resin constituting the insulating material 22 include epoxy resin and phenol resin. Furthermore, the insulating material 22 preferably contains a filler. Examples of the filler contained in the insulating material 22 include inorganic fillers such as silica particles, alumina particles, and metal particles.

[0122] The insulating material 22 may be composed of the same material as the encapsulation layer 20 .

[0123] In the planar direction, a cathode connection layer such as an anode connection layer may be provided between the cathode layer 12, particularly the second conductive layer 12C, and the second through-hole conductor 42, but it is preferable that no cathode connection layer is provided. In the latter case, the second through-hole conductor 42 may be directly connected to the end face of the second conductive layer 12C.

[0124] 1, the second through-hole conductor 42 is provided only on the inner wall surface of the second through hole 52. In this case, the second through hole 52 may be provided with a resin filled portion 92 filled with a resin material. The resin filled portion 92 is provided in the space surrounded by the second through-hole conductor 42 in the second through hole 52. When the space in the second through hole 52 is eliminated by providing the resin filled portion 92, the occurrence of delamination of the second through-hole conductor 42 is suppressed. The resin filled portion 92 may be a conductor or an insulator.

[0125] Examples of materials that can be used to form the internal via conductors 60 include metal materials that contain low-resistance metals such as silver, gold, and copper.

[0126] The internal via conductor 60 is formed, for example, by plating the inner wall surface of a through hole that penetrates the sealing layer 20 in the thickness direction with the above-mentioned metal material, or by filling it with a conductive paste and then performing a heat treatment.

[0127] 6-1 to 6-12 are schematic cross-sectional views for explaining an example of a method for manufacturing the capacitor element shown in FIG. 1. FIG. 6-1 shows a step of preparing an anode plate. FIG. 6-2 shows a step of forming a dielectric layer. FIG. 6-3 shows a step of forming an insulating mask layer. FIG. 6-4 shows a step of forming a solid electrolyte layer. FIG. 6-5 shows a step of forming a first conductive layer. FIG. 6-6 shows a step of forming a through hole. FIG. 6-7 shows a step of forming an insulating material. FIG. 6-8 shows a step of polishing the insulating material. FIG. 6-9 shows a step of forming a second conductive layer. FIG. 6-10 shows a step of forming a sealing layer. FIG. 6-11 shows a step of forming a first through hole and a second through hole. FIG. 6-12 shows a step of forming a through hole conductor and an external electrode layer.

[0128] Capacitor element 1 shown in FIG. 1 is formed, for example, as follows.

[0129] First, as shown in FIG. 6-1, an anode plate 11 having a core portion 11A and porous portions 11B on both main surfaces thereof is prepared.

[0130] Next, as shown in FIG. 6-2, the dielectric layer 13 is formed on the porous portion 11B.

[0131] Next, as shown in FIG. 6-3, an insulating mask layer 25 is formed on the dielectric layer 13.

[0132] Next, solid electrolyte layer 12A is formed on dielectric layer 13 in the region surrounded by insulating mask layer 25, as shown in FIG. 6-4.

[0133] Next, as shown in FIG. 6-5, a first conductive layer 12B is formed on the solid electrolyte layer 12A.

[0134] Next, as shown in FIG. 6-6, a through hole 53 penetrating the insulating mask layer 25, the dielectric layer 13 and the anode plate 11 is formed.

[0135] Next, as shown in FIG. 6-7, an insulating material 22 is laminated so as to cover the insulating mask layer 25 and the first conductive layer 12B, and the through holes 53 are filled with the insulating material 22.

[0136] Next, as shown in FIG. 6-8, the insulating material 22 is polished and thinned until the first conductive layer 12B is exposed.

[0137] Next, a second conductive layer 12C is formed on the first conductive layer 12B and the insulating material 22, as shown in FIG. 6-9.

[0138] Next, as shown in FIG. 6-10, the sealing layer 20 is formed to cover the second conductive layer 12C and the insulating material 22.

[0139] 6-11, a first through hole 51 is formed penetrating the sealing layer 20, the insulating material 22, the insulating mask layer 25, the dielectric layer 13, and the anode plate 11, and a second through hole 52 is formed penetrating the sealing layer 20, the second conductive layer 12C, and the insulating material 22. The second through hole 52 is located inside the region where the through hole 53 was formed.

[0140] 6-12, a first through-hole conductor 41 is formed in the first through-hole 51, and a second through-hole conductor 42 is formed in the second through-hole 52. Resin filling portions 91 and 92 may be formed in the first through-hole conductor 41 and the second through-hole conductor 42, respectively. Finally, a first external electrode layer 31 is formed on the sealing layer 20 so as to cover the first through-hole conductor 41, and a second external electrode layer 32 is formed on the sealing layer 20 so as to cover the second through-hole conductor 42.

[0141] 7-1 to 7-6 are schematic cross-sectional views illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1. FIG. 7-1 shows a state after through holes are formed. FIG. 7-2 shows a step of forming an insulating material. FIG. 7-3 shows a step of forming a second conductive layer. FIG. 7-4 shows a step of forming a sealing layer. FIG. 7-5 shows a step of forming a first through hole and a second through hole. FIG. 7-6 shows a step of forming a through-hole conductor and an external electrode layer.

[0142] Capacitor element 1 shown in FIG. 1 may be formed, for example, as follows.

[0143] First, as shown in FIG. 7-1, a through hole 53 penetrating the insulating mask layer 25, the dielectric layer 13 and the anode plate 11 is formed in the same manner as in the case shown in FIGS. 6-1 to 6-6.

[0144] Next, as shown in FIG. 7-2, the insulating material 22 is formed only in the through-holes 53 by a method such as filling with a resin material, screen printing, dispenser application, or inkjet printing.

[0145] 7-3 to 7-6, in the same manner as in the case shown in Fig. 6-9 to 6-12, the second conductive layer 12C, the sealing layer 20, the first through hole 51, the second through hole 52, the first through-hole conductor 41, the second through-hole conductor 42, the first external electrode layer 31 and the second external electrode layer 32 are formed. Note that resin filling portions 91 and 92 may be formed as necessary.

[0146] [Second embodiment] FIG. 8 is a plan view illustrating an example of a capacitor element according to a second embodiment of the present invention.

[0147] In the capacitor element 3 shown in FIG. 8, the anode plate 11 has a porous portion 11B on only one main surface of the core portion 11A, and components such as the capacitor portion 10 (anode plate 11, dielectric layer 13, and cathode layer 12), sealing layer 20, and external electrode layer 30 (first external electrode layer 31 and second external electrode layer 32) are provided on only one surface of the capacitor element 3.

[0148] In the example shown in Figure 8, one end of the through-hole conductor 40 (first through-hole conductor 41 and second through-hole conductor 42) is electrically connected to the external electrode layer 30, but the other end is exposed to the surface on which the capacitor section 10 etc. are not provided.

[0149] 9-1 to 9-12 are schematic cross-sectional views for explaining an example of a method for manufacturing the capacitor element shown in FIG. 8. FIG. 9-1 shows a step of preparing an anode plate. FIG. 9-2 shows a step of forming a dielectric layer. FIG. 9-3 shows a step of forming an insulating mask layer. FIG. 9-4 shows a step of forming a solid electrolyte layer. FIG. 9-5 shows a step of forming a first conductive layer. FIG. 9-6 shows a step of forming a through hole. FIG. 9-7 shows a step of forming an insulating material. FIG. 9-8 shows a step of polishing the insulating material. FIG. 9-9 shows a step of forming a second conductive layer. FIG. 9-10 shows a step of forming a sealing layer. FIG. 9-11 shows a step of forming a first through hole and a second through hole. FIG. 9-12 shows a step of forming a through hole conductor and an external electrode layer.

[0150] Capacitor element 3 shown in FIG. 8 may be formed, for example, as follows.

[0151] First, as shown in FIG. 9-1, an anode plate 11 having a porous portion 11B only on one main surface of a core portion 11A is prepared.

[0152] Next, as shown in FIGS. 9-2 to 9-5, dielectric layer 13, insulating mask layer 25, solid electrolyte layer 12A and first conductive layer 12B are formed in the same manner as shown in FIGS. 6-2 to 6-5.

[0153] Next, as shown in FIG. 9-6, the capacitor element sheet in which the through holes 53 are formed in the same manner as in the case shown in FIG. 6-6 is placed on a carrier board CB.

[0154] 9-7 to 9-12, in the same manner as in the cases shown in Fig. 6-7 to 6-12, an insulating material 22 is laminated and polished, and then a second conductive layer 12C, a sealing layer 20, a first through hole 51, a second through hole 52, a first through-hole conductor 41, a second through-hole conductor 42, a first external electrode layer 31, and a second external electrode layer 32 are formed. Note that resin filling portions 91 and 92 may be formed as necessary.

[0155] [Other embodiments] The capacitor element of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration, manufacturing conditions, and the like of the capacitor element.

[0156] In the capacitor element of the present invention, one capacitor portion may be disposed inside the sealing layer, or a plurality of capacitor portions may be disposed inside the sealing layer.

[0157] In the capacitor element of the present invention, when a plurality of capacitor parts are arranged inside the sealing layer, adjacent capacitor parts may be physically separated from each other. Therefore, adjacent capacitor parts may be electrically separated from each other or may be electrically connected to each other. It is preferable that an insulating material such as a sealing layer is filled in the part where adjacent capacitor parts are separated from each other. The interval between adjacent capacitor parts may be constant in the thickness direction or may become smaller in the thickness direction.

[0158] In the capacitor element of the present invention, when a plurality of capacitor parts are arranged inside the sealing layer, the plurality of capacitor parts may be arranged so as to be aligned in the planar direction, may be arranged so as to be stacked in the thickness direction, or may be arranged in a combination of both. The plurality of capacitor parts may be arranged regularly or irregularly. The size, shape, etc. of the capacitor elements may be the same, or may be partially or entirely different. The configuration of each of the capacitor elements is preferably the same, but capacitor elements with different configurations may be included.

[0159] The capacitor element of the present invention can be suitably used as a constituent material of a composite electronic component. Such a composite electronic component includes, for example, the capacitor element of the present invention, an external electrode layer provided on the surface of the sealing layer of the capacitor element and electrically connected to the anode plate and cathode layer of the capacitor element, and an electronic component connected to the external electrode layer.

[0160] In the composite electronic component, the electronic component connected to the external electrode layer may be 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. Also, a composite of the passive element and the active element may be connected to the external electrode layer.

[0161] An example of a passive element is an inductor, etc. An example of an active element is a memory, a GPU (Graphical Processing Unit), a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a PMIC (Power Management IC), etc.

[0162] The capacitor element of the present invention has a sheet-like shape as a whole. Therefore, in a composite electronic component, the capacitor element can be treated like a mounting board, and electronic components can be mounted on the capacitor element. Furthermore, by making the electronic components mounted on the capacitor element into a sheet-like shape, it is also possible to connect the capacitor element and the electronic components in the thickness direction via through-hole conductors that penetrate each electronic component in the thickness direction. As a result, the active elements and passive elements can be configured like a single module.

[0163] For example, a switching regulator can be formed by electrically connecting the capacitor element of the present invention between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied.

[0164] In a composite electronic component, a circuit layer may be formed on either side of a capacitor matrix sheet on which a plurality of capacitor elements of the present invention are laid out, and the circuit layer may be connected to a passive element or an active element.

[0165] Alternatively, the capacitor element of the present invention may be placed in a cavity previously provided in a substrate, embedded in resin, and then a circuit layer may be formed on the resin. Another electronic component (passive element or active element) may be mounted in another cavity of the same substrate.

[0166] Alternatively, the capacitor element of the present invention may be mounted on a smooth carrier such as a wafer or glass, an outer layer made of resin may be formed, a circuit layer may be formed, and then the capacitor element may be connected to a passive or active element.

[0167] The present specification discloses the following:

[0168] <1> a capacitor section including an anode plate having a porous portion on at least one main surface of a core portion, a dielectric layer provided on a surface of the porous portion, and a cathode layer provided on a surface of the dielectric layer; a sealing layer provided to cover the capacitor portion; a first through-hole conductor that is provided to penetrate the capacitor portion and the sealing layer in a thickness direction so as to be directly electrically connected to the anode plate, and both ends of the first through-hole conductor are extended to the surface of the sealing layer; a second through-hole conductor provided to penetrate the capacitor portion and the sealing layer in the thickness direction so as to be directly electrically connected to the cathode layer, the second through-hole conductor having both ends extending to the surface of the sealing layer; a first external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the first through-hole conductor; a second external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the second through-hole conductor; At least a portion of the first external electrode layer overlaps the cathode layer in the thickness direction.

[0169] <2> the cathode layer, the first external electrode layer, and the second external electrode layer each include a copper layer; When the thickness of the copper layer of the cathode layer is d1, the thickness of the copper layer of the first external electrode layer is d2, and the thickness of the copper layer of the second external electrode layer is d3, d1 ≧ d2 and d1 ≧ d3 are satisfied. <1> The capacitor element according to claim 1 .

[0170] <3> When the area of ​​the first external electrode layer is S1 and the area of ​​the second external electrode layer is S2, S1>S2 is satisfied. <1> or <2> The capacitor element according to claim 1 .

[0171] <4> an internal via conductor provided to penetrate the sealing layer in the thickness direction, one end of the internal via conductor being electrically connected to the second external electrode layer and the other end of the internal via conductor being electrically connected to the cathode layer; <1> ~ <3> 13. A capacitor element according to claim 12.

[0172] <5> the cathode layer includes a solid electrolyte layer provided on a surface of the dielectric layer, a first conductive layer provided on the surface of the solid electrolyte layer, and a second conductive layer provided on the surface of the first conductive layer so as to be directly electrically connected to the second through-hole conductor; <1> ~ <4> 13. A capacitor element according to claim 12. [Explanation of symbols]

[0173] 1, 2, 3 Capacitor element 10 Capacitor section 11 Anode plate 11A core 11B Porous part 12 Cathode layer 12A solid electrolyte layer 12B First conductive layer 12C 2nd conductor layer 12Cu Cathode layer copper layer 13 Dielectric layer 20 Sealing layer 22 Insulating materials 25 Insulating Mask Layer 30 External electrode layer 31 First external electrode layer 31Cu Copper layer of the first external electrode layer 32 Second external electrode layer 32Cu Copper layer of the second external electrode layer 40 Through-hole conductor 41 First through-hole conductor 42 Second through hole conductor 51 First through hole 52 Second through hole 53 Through hole 60 Internal via conductor 91, 92 Resin filling section

Claims

1. a capacitor section including an anode plate having a porous portion on at least one main surface of a core portion, a dielectric layer provided on a surface of the porous portion, and a cathode layer provided on a surface of the dielectric layer; a sealing layer provided to cover the capacitor portion; a first through-hole conductor provided to penetrate the capacitor portion and the sealing layer in a thickness direction so as to be electrically connected directly to the anode plate, the first through-hole conductor having both ends extending to the surface of the sealing layer; a second through-hole conductor provided to penetrate the capacitor portion and the sealing layer in the thickness direction so as to be electrically connected directly to the cathode layer, the second through-hole conductor having both ends extending to the surface of the sealing layer; a first external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the first through-hole conductor; a second external electrode layer provided on a surface of the sealing layer so as to be electrically connected to the second through-hole conductor; At least a portion of the first external electrode layer overlaps the cathode layer in the thickness direction, the cathode layer, the first external electrode layer, and the second external electrode layer each include a copper layer; When the thickness of the copper layer of the cathode layer is d1, the thickness of the copper layer of the first external electrode layer is d2, and the thickness of the copper layer of the second external electrode layer is d3, A capacitor element satisfying d1≧d2 and d1≧d3.

2. When the area of ​​the first external electrode layer is S1 and the area of ​​the second external electrode layer is S2, The capacitor element according to claim 1 , wherein S1>S2 is satisfied.

3. 3. The capacitor element according to claim 1, further comprising an internal via conductor arranged to penetrate the sealing layer in the thickness direction, one end of which is electrically connected to the second external electrode layer and the other end of which is electrically connected to the cathode layer.

4. 3. The capacitor element according to claim 1, wherein the cathode layer includes: a solid electrolyte layer provided on a surface of the dielectric layer; a first conductor layer provided on the surface of the solid electrolyte layer; and a second conductor layer provided on the surface of the first conductor layer so as to be directly electrically connected to the second through-hole conductor.

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