Capacitor element

Abstract

This capacitor element 1 comprises: a capacitor part 10 which comprises a positive electrode plate 11 that has a porous part 11B on at least one main surface of a core part 11A, a dielectric layer 13 that is provided on the surface of the porous part 11B, and a negative electrode layer 12 that is provided on the surface of the dielectric layer 13; a sealing layer 20 which is provided so as to cover the capacitor part 10; a first through-hole conductor 41 which is provided so as to penetrate through the capacitor part 10 and the sealing layer 20 in the thickness direction so as to be electrically directly connected to the positive electrode plate 11, and has both end parts led out to the surface of the sealing layer 20; a second through-hole conductor 42 which is provided so as to penetrate through the capacitor part 10 and the sealing layer 20 in the thickness direction so as to be electrically directly connected to the negative electrode layer 12, and has both end parts led out to the surface of the sealing layer 20; a first external electrode layer 31 which is 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 which is provided on the surface of the sealing layer 20 so as to be electrically connected to the second through-hole conductor 42. At least a part of the first external electrode layer 31 overlaps with the negative electrode layer 12 in the thickness direction.

Description

Capacitor element

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

[0002] Patent Document 1 describes a solid electrolytic capacitor including: a foil-shaped anode having a porous portion on at least one surface thereof 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 through-hole electrodes that penetrate the insulating layer and the anode to electrically connect the electrode and the anode and / or penetrate the insulating layer and the cathode to electrically connect the electrode and the cathode, wherein at least one of the through-hole electrodes has an elongated hole shape.

[0003] Japanese Patent Application Laid-Open No. 2007-281111

[0004] In recent years, the miniaturization and increased power output of electronic devices have led to a demand for higher component density. To address this demand, embedding capacitor elements in substrates directly below the power supply, such as GPU (Graphical Processing Unit) substrates, has been considered. While large currents flow in these applications, conventional capacitor element structures lack sufficient heat dissipation capabilities, potentially resulting in heat generation due to the internal resistance of the capacitor element. Such heat generation from various components can adversely affect the safety, reliability, performance, and lifespan of electronic devices.

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

[0006] The present invention has been made to solve the above problems, and an object of the present invention is to provide a capacitor element that can improve heat dissipation properties.

[0007] a first through-hole conductor that is 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 that is 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 second through-hole conductor being extended to the surface of the sealing layer; a first external electrode layer that is 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 that is 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.

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

[0009] FIG. 1 is a cross-sectional view schematically illustrating an example of a capacitor element according to a first embodiment of the present invention. FIG. 2 is a plan view of the capacitor element shown in FIG. 1 taken along line A-A. FIG. 3 is a plan view of the capacitor element shown in FIG. 1 taken along line B-B. FIG. 4 is a plan view of the capacitor element shown in FIG. 1 taken along line C-C. FIG. 5 is a cross-sectional view schematically illustrating another example of a capacitor element according to the first embodiment of the present invention. FIG. 6-1 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of preparing an anode plate. FIG. 6-2 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a dielectric layer. FIG. 6-3 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming an insulating mask layer. FIG. 6-4 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a solid electrolyte layer. FIG. 6-5 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a first conductor layer. FIG. 6-6 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a through hole. FIG. 6-7 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming an insulating material. FIG. 6-8 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of polishing the insulating material. FIG. 6-9 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a second conductor layer. FIG. 6-10 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a sealing layer. FIG. 6-11 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1, showing the step of forming a first through hole and a second through hole. FIG. 6-12 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a through-hole conductor and an external electrode layer. FIG. 7-1 is a cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the state after forming the through hole. FIG. 7B is a cross-sectional view illustrating another example of the method for manufacturing the capacitor element shown in FIG. 1, showing a step of forming an insulating material.FIG. 7-3 is a cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a second conductive layer. FIG. 7-4 is a cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a sealing layer. FIG. 7-5 is a cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a first through hole and a second through hole. FIG. 7-6 is a cross-sectional view illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1 , showing the step of forming a through-hole conductor and an external electrode layer. FIG. 8 is a plan view schematically illustrating an example of a capacitor element according to a second embodiment of the present invention. FIG. 9-1 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing the step of preparing an anode plate. FIG. 9-2 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing the step of forming a dielectric layer. FIG. 9-3 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing the step of forming an insulating mask layer. FIG. 9-4 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a solid electrolyte layer. FIG. 9-5 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a first conductor layer. FIG. 9-6 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a through-hole. FIG. 9-7 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming an insulating material. FIG. 9-8 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of polishing the insulating material. FIG. 9-9 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a second conductor layer. FIG. 9-10 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a sealing layer. FIG. 9-11 is a cross-sectional view illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8 , showing the step of forming a first through-hole and a second through-hole. 9 to 12 are cross-sectional views illustrating an example of a method for manufacturing the capacitor element shown in FIG. 8, showing steps for forming through-hole conductors and external electrode layers.

[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 substitution or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and differences will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned one after the other for each embodiment.

[0012] In the following description, when no particular distinction is made between the embodiments, they will simply be referred to as "the capacitor element of the present invention."

[0013] In this specification, terms indicating the relationship between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms indicating the shape of elements are not expressions that only express a strict meaning, but are expressions that also include a range of substantial equivalence, for example, a difference of about a few percent.

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

[0015] [First embodiment] Fig. 1 is a cross-sectional view schematically showing an example of a capacitor element according to a first embodiment of the present invention. Fig. 2 is a plan view of the capacitor element shown in Fig. 1 taken along line A-A. Fig. 3 is a plan view of the capacitor element shown in Fig. 1 taken along line B-B. Fig. 4 is a plan view of the capacitor element shown in Fig. 1 taken along line CC. Note that Fig. 1 is a cross-sectional view of the capacitor element shown in Figs. 2 to 4 taken along line D-D.

[0016] The capacitor element 1 shown in Figures 1 to 4 comprises a capacitor section 10, a sealing layer 20 provided to cover the capacitor section 10, a through-hole conductor 40 provided to penetrate the capacitor section 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 section 10 is disposed inside sealing layer 20. The number of capacitor sections 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 makes up an electrolytic capacitor. In the example shown in Fig. 1, the anode plate 11 has the porous portion 11B on both main surfaces of the core portion 11A, but the porous portion 11B may be provided on only one main surface of the core portion 11A.

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

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

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

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

[0023] 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] The first through-hole conductor 41 may be provided on at least the inner wall surface of the first through hole 51 that penetrates the capacitor section 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 inside the cathode layer 12.

[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 section 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 be 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 inside the cathode layer 12.

[0029] Although not shown in FIGS. 1 to 4, the through-hole conductors 40 may include a third through-hole conductor that is not electrically connected to the anode plate 11 and the 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 or more first external electrode layers 31 may be provided for one capacitor section 10. Similarly, one or more second external electrode layers 32 may be provided for one capacitor section 10. The number of first external electrode layers 31 for one capacitor section 10 may be the same as or different from the number of second external electrode layers 32.

[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. Furthermore, the planar shape of the external electrode layer 30 may be an L-shape, a C-shape, a stepped 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 led out through an internal via conductor, as in the example shown in FIG. 5 (described later). However, 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 led out through the second through-hole conductor 42. By electrically connecting the second through-hole conductor 42 directly to the cathode layer 12 in this manner, the heat dissipation path, i.e., the heat dissipation area, can be increased compared to when the cathode layer 12 is led out only through the internal via conductor. Furthermore, in the example shown in FIG. 1 , at least a portion 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 performance of the capacitor element 1 can be improved. As a result, the temperature rise due to heat generation in the capacitor element 1 can be suppressed.

[0035] Furthermore, by electrically connecting the second through-hole conductor 42 directly to the cathode layer 12, the second through-hole conductor 42 and the cathode layer 12 are in direct contact without being connected through a resin portion, which is a different material, thereby improving the rigidity of the capacitor element 1. Similarly, by overlapping at least a portion of the first external electrode layer 31 with the cathode layer 12 in the thickness direction, the area of ​​the first external electrode layer 31 can be increased, thereby improving the rigidity of the capacitor element 1. If the cathode layer 12 is not extended using an internal via conductor as in the example shown in Figure 1, the capacitor element 1 can be made thinner, but warping of the capacitor element 1 may occur. However, by overlapping the first external electrode layer 31 with the cathode layer 12, the rigidity of the capacitor element 1 is improved and such warping can 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 phrase "a through-hole conductor is electrically connected directly to a conductive layer such as a cathode layer or an anode plate" excludes cases 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, i.e., the side wall portion of the through-hole conductor is electrically connected to the conductive layer. In the example shown in Figure 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 electrically connected directly 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] 1, the first external electrode layer 31 may only partially overlap 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 entire area of ​​the first external electrode layer 31 is not particularly limited, but is preferably 50% to 90%, and more preferably 60% to 80%.

[0040] 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, where 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 that d1≧d2 and d1≧d3 be satisfied. This can suppress current concentration in the cathode layer 12 and suppress heat generation. Furthermore, increasing the volume of the copper layer 12Cu of the cathode layer 12 can promote thermal diffusion and suppress damage to the capacitor section 10.

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

[0042] In the example shown in FIG. 1, the copper layer 12Cu is the second conductive 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] Furthermore, when the cathode layer 12 is composed of multiple layers including the copper layer 12Cu, it is preferable that the copper layer 12Cu be one or more layers that are closest to the first external electrode layer 31 and the second external electrode layer 32 among the multiple layers that constitute 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 that constitute 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 the capacitor element 1. Therefore, based on a comparison between the volume of the anode plate 11 and the volume of the cathode layer 12, a preferred area ratio between the first external electrode layer 31 and the second external electrode layer 32 will be described.

[0046] The thickness of the core 11A of the anode plate 11 is set to, 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 taken along line A-A in Fig. 1 and shown in Fig. 2. Furthermore, the thickness of the copper layer 12Cu of each cathode layer 12 on both main surfaces of the anode plate 11 is set to, for example, approximately 30 μm, and the area of ​​the copper layer 12Cu is assumed to be approximately 100% in the plane taken along line B-B in Fig. 1 and 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. As described above, the area of ​​the core 11A of the anode plate 11 is approximately the same as the area of ​​the copper layer 12Cu of each cathode layer 12 on both sides of the core 11A. Therefore, if the total thickness of the copper layer 12Cu of the cathode layers 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 better thermal conductivity (heat dissipation) than the anode. Furthermore, when an internal via conductor is connected to the cathode layer 12, as in the second embodiment described below, the cathode has even 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 this specification, when simply referring to "area," it means the area in a plan view from the thickness direction.

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

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

[0052] Comparisons such as S1>S2 and S1 / S2 are 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 of the capacitor section 10.

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

[0054] 1, similar elements (members) are arranged on both main surfaces of the core portion 11A of the anode plate 11. This also serves to prevent warping of the capacitor element 1. It also serves to improve the capacitance of the capacitor portion 10.

[0055] Furthermore, 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 allows the heat dissipation properties of the capacitor element 1 to be uniform.

[0056] Furthermore, it is preferable that the through-hole conductors 40 (i.e., the first through-hole conductors 41 and the second through-hole conductors 42 are not distinguished from each other) provided in the capacitor element 1 be arranged at equal pitches. This also makes it possible to uniformize the heat dissipation properties of the capacitor element 1. It is also possible to prevent the occurrence of 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 main surface of the anode plate 11 .

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

[0059] The capacitor unit 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 short-circuiting between them is prevented. The insulating mask layer 25 may be provided so as to surround a portion of the periphery of the cathode layer 12, but is preferably provided so as to surround the entire periphery of the cathode layer 12.

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

[0061] 5 further includes an internal via conductor 60 that penetrates 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, heat dissipation can be further improved. In addition, adhesion between layers can be improved, and delamination can be suppressed.

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

[0063] Furthermore, the internal via conductor 60 is electrically connected to the cathode layer 12. This allows the cathode layer 12 to be electrically led out of the sealing layer 20 via the internal via conductor 60 and the second through-hole conductor 42, and to 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 from 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 stepped shape, etc.

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

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

[0071] The pore diameter of the porous portion 11B is preferably 10 nm or more and 600 nm or less. The pore diameter of the porous portion 11B refers to the median diameter D50 measured with a mercury porosimeter. The pore diameter of the porous portion 11B can be controlled, for example, by adjusting various etching conditions.

[0072] The dielectric layer 13 provided on the surface of the porous portion 11B is porous, reflecting the surface condition of the porous portion 11B, and has a finely uneven surface shape. The dielectric layer 13 is preferably made of an oxide film of the valve metal. For example, when 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 a solid electrolyte layer 12A, examples of materials constituting the solid electrolyte layer 12A include conductive polymers such as polypyrroles, polythiophenes, and polyanilines. Among these, polythiophenes are preferred, and poly(3,4-ethylenedioxythiophene), also known as PEDOT, is particularly preferred. The conductive polymer may also contain a dopant such as polystyrene sulfonate (PSS). The solid electrolyte layer 12A preferably includes an inner layer that fills the pores (recesses) of the dielectric layer 13 and an outer layer that covers the dielectric layer 13.

[0075] The thickness of the solid electrolyte layer 12A from the surface of the porous portion 11B is preferably 2 μm or more and 20 μm or less.

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

[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 composed of only a conductive resin layer or only a metal layer, but the first conductive layer 12B is preferably composed of only a conductive resin layer, and the second conductive layer 12C is preferably composed of only a metal layer. The first conductive layer 12B preferably covers the entire surface of the solid electrolyte layer 12A.

[0079] Examples of the conductive resin layer include a conductive adhesive layer (conductive paste layer) containing at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and 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 the main component. The term "main component" refers to the elemental component with the largest weight percentage.

[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] In addition, when the first conductor layer 12B includes a copper paste layer, the thickness d1 of the copper layer 12Cu of the above-mentioned cathode layer 12 is the combined thickness of the copper layer 12Cu of the second conductor layer 12C and the copper paste layer of the first conductor layer 12B.

[0084] The carbon paste layer of the first conductor layer 12B is provided to electrically and mechanically connect the solid electrolyte layer 12A and the copper paste layer of the first conductor 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 sponge transfer, screen printing, dispenser application, inkjet printing, or other methods. Note that the carbon paste layer is preferably laminated with the copper paste layer in the subsequent process while it is still viscous 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 coating, dispenser coating, 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 by 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, and in this case, the sealing layer 20 is preferably made of an insulating resin.

[0089] Examples of insulating resins that form the sealing layer 20 include epoxy resins and phenolic resins.

[0090] Preferably, the sealing layer 20 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 the like 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 constitute the insulating mask layer 25 include polyphenylsulfone resin, polyethersulfone resin, cyanate ester resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), polyimide resin, polyamideimide resin, epoxy resin, and derivatives or precursors thereof.

[0095] The insulating mask layer 25 may be made of the same resin as the sealing layer 20. Unlike the sealing layer 20, if the insulating mask layer 25 contains an inorganic filler, it may adversely affect the effective capacitance portion of the capacitor section 10. Therefore, it is preferable that the insulating mask layer 25 be 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, or inkjet printing.

[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 for 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 materials constituting 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 surfaces of the first through-hole conductors 41.

[0100] In order to improve the adhesion between the first external electrode layer 31 and other components, in this case, the adhesion 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 the 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 conductor layer 12B and the copper plating layer and copper foil layer of the second conductor 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 materials constituting 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, the adhesion 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 the 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 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 also be provided on only one main surface 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 that faces the inner wall surface of the first through hole 51 in the planar direction. This allows the anode plate 11 to be 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 surface 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, it is preferable that the first through-hole conductor 41 is electrically connected to the anode plate 11 along the entire periphery 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 tends to decrease, which tends to decrease the equivalent series resistance (ESR).

[0112] The first through-hole conductors 41 are formed, for example, as follows. First, first through holes 51 are formed by drilling, laser processing, or the like, penetrating the capacitor section 10 and the sealing layer 20 in the thickness direction. Then, the inner wall surfaces of the first through holes 51 are metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the first through-hole conductors 41. When forming the first through-hole conductors 41, for example, metallizing the inner wall surfaces of the first through holes 51 with an electroless copper plating process, an electrolytic copper plating process, or the like facilitates processing. Regarding the method of forming the first through-hole conductors 41, in addition to the method of metallizing the inner wall surfaces of the first through holes 51, a method of filling the first through holes 51 with a metal material, a composite material of metal and resin, or the like may also be used.

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

[0114] The anode connection layer is provided between the anode plate 11 and the first through-hole conductor 41 in the surface direction, and therefore 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 to form the external electrode layer 30 (e.g., the first external electrode layer 31) is suppressed, and therefore penetration 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 containing nickel as a main component, which reduces damage to the metal (e.g., aluminum) constituting the anode plate 11, and therefore improves the barrier properties of the anode connecting layer against the anode plate 11.

[0116] 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 filling portion 91 filled with a resin material. The resin filling portion 91 is provided in the space surrounded by the first through-hole conductor 41 inside the first through hole 51. When the space inside the first through hole 51 is eliminated by providing the resin filling portion 91, the occurrence of delamination of the first through-hole conductor 41 is suppressed. The resin filling portion 91 may be a conductor or an insulator.

[0118] 1 , the second through-hole conductor 42 is electrically connected to the cathode layer 12, particularly to the second conductive layer 12C, on the inner wall surface of the second through hole 52. More specifically, the second through-hole conductor 42 is preferably electrically connected to the end surface of the second conductive layer 12C that faces the inner wall surface of the second through hole 52 in the planar direction. This allows the cathode layer 12 to be electrically led out via the second through-hole conductor 42.

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

[0120] The second through-hole conductor 42 is formed, for example, as follows. First, a through hole 53 is formed by drilling, laser processing, or the like, penetrating the capacitor unit 10 in the thickness direction. Next, the through hole 53 is filled with the insulating material 22. The portion filled with the insulating material 22 is then 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 in the planar direction between the inner wall surface of the previously formed through hole 53 and the inner wall surface of the second through hole 52. Then, 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, thereby forming the second through-hole conductor 42. When forming the second through-hole conductor 42, for example, metallizing the inner wall surface of the second through hole 52 by electroless copper plating, electrolytic copper plating, or the like can facilitate processing. In addition, as a method for 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 that makes up the insulating material 22 include epoxy resin and phenolic 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 made 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 between the cathode layer 12, particularly the second conductive layer 12C, and the second through-hole conductor 42. In the latter case, the second through-hole conductor 42 may be directly connected to the end surface 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 filling portion 92 filled with a resin material. The resin filling portion 92 is provided in the space surrounded by the second through-hole conductor 42 inside the second through hole 52. When the space inside the second through hole 52 is eliminated by providing the resin filling portion 92, the occurrence of delamination of the second through-hole conductor 42 is suppressed. The resin filling 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 containing 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] FIGS. 6-1 to 6-12 are cross-sectional schematic views illustrating 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 conductor 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 conductor 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] The capacitor element 1 shown in FIG. 1 is formed, for example, as follows.

[0129] First, as shown in FIG. 6A, 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. 6B, the dielectric layer 13 is formed on the porous portion 11B.

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

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

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

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

[0135] Next, as shown in FIGS. 6-7, an insulating material 22 is laminated 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 FIGS. 6-8, the insulating material 22 is polished and thinned until the first conductive layer 12B is exposed.

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

[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 that penetrates 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 that penetrates the sealing layer 20, the second conductor 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 cross-sectional schematic views illustrating another example of a method for manufacturing the capacitor element shown in FIG. 1. FIG. 7-1 shows the state after the through holes have been formed. FIG. 7-2 shows the step of forming an insulating material. FIG. 7-3 shows the step of forming a second conductive layer. FIG. 7-4 shows the step of forming a sealing layer. FIG. 7-5 shows the step of forming a first through hole and a second through hole. FIG. 7-6 shows the step of forming a through-hole conductor and an external electrode layer.

[0142] The 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 is formed through the insulating mask layer 25, the dielectric layer 13 and the anode plate 11 in the same manner as shown in FIGS. 6-1 to 6-6.

[0144] Next, as shown in FIG. 7B, 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 cases shown in Figures 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 schematically showing 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 on the side where the capacitor section 10 etc. is not provided.

[0149] 9-1 to 9-12 are cross-sectional schematic views illustrating 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 conductor 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 conductor 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] The capacitor element 3 shown in FIG. 8 may be formed, for example, as follows.

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

[0152] Next, as shown in FIGS. 9-2 to 9-5, the dielectric layer 13, the insulating mask layer 25, the solid electrolyte layer 12A, and the first conductor 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 Figures 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, etc. 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 multiple capacitor units are disposed inside the sealing layer, adjacent capacitor units only need to be physically separated. Therefore, adjacent capacitor units may be electrically separated or electrically connected. The portion where adjacent capacitor units are separated is preferably filled with an insulating material such as a sealing layer. The distance between adjacent capacitor units may be constant in the thickness direction or may decrease in the thickness direction.

[0158] In the capacitor element of the present invention, when multiple capacitor sections are arranged inside the sealing layer, the multiple capacitor sections may be arranged so as to be lined up in the surface direction, so as to be stacked in the thickness direction, or a combination of both. The multiple capacitor sections may be arranged regularly or irregularly. The size, shape, etc. of the capacitor elements may be the same, or some or all of them may be different. The capacitor elements preferably have the same configuration, but capacitor elements with different configurations may be included.

[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, external electrode layers provided on the surface of the sealing layer of the capacitor element and electrically connected to the anode plate and cathode layer of the capacitor element, respectively, and an electronic component connected to the external electrode layers.

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

[0161] Examples of passive elements include inductors, etc. Examples of active elements include memories, GPUs (Graphical Processing Units), CPUs (Central Processing Units), MPUs (Micro Processing Units), and PMICs (Power Management ICs).

[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 substrate, and electronic components can be mounted on the capacitor element. Furthermore, by making the electronic components mounted on the capacitor element sheet-like, it is also possible to connect the capacitor element and the electronic components in the thickness direction via through-hole conductors that penetrate each electronic component in the thickness direction. As a result, active elements and passive elements can be configured like a single module.

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

[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 element comprising: 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 to be electrically connected directly to the anode plate, the first through-hole conductor having both ends 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 to be electrically connected directly to the cathode layer, the second through-hole conductor having both ends extended to the surface of the sealing layer; a first external electrode layer provided on the surface of the sealing layer to be electrically connected to the first through-hole conductor; and a second external electrode layer provided on the surface of the sealing layer 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.

[0169] <2> The capacitor element according to <1>, wherein the cathode layer, the first external electrode layer, and the second external electrode layer each include a copper layer, and 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.

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

[0171] <4> The capacitor element according to any one of <1> to <3>, further comprising an internal via conductor that is provided so as 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.

[0172] <5> The capacitor element according to any one of <1> to <4>, 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 electrically connected directly to the second through-hole conductor.

[0173] 1, 2, 3 Capacitor element 10 Capacitor portion 11 Anode plate 11A Core portion 11B Porous portion 12 Cathode layer 12A Solid electrolyte layer 12B First conductor layer 12C Second conductor layer 12Cu Copper layer of cathode layer 13 Dielectric layer 20 Sealing layer 22 Insulating material 25 Insulating mask layer 30 External electrode layer 31 First external electrode layer 31Cu Copper layer of first external electrode layer 32 Second external electrode layer 32Cu Copper layer of 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-filled portion

Claims

1. A capacitor element comprising: 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 the 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 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.

2. The capacitor element according to claim 1, wherein the cathode layer, the first external electrode layer and the second external electrode layer each include a copper layer, and 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.

3. A capacitor element according to claim 1 or 2, wherein when the area of ​​the first external electrode layer is S1 and the area of ​​the second external electrode layer is S2, the relationship S1>S2 is satisfied.

4. A capacitor element as described in any one of claims 1 to 3, further comprising an internal via conductor that is 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.

5. A capacitor element described in any one of claims 1 to 4, wherein 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.

Images