Capacitor element

Abstract

A capacitor element 1 comprises a capacitor part 10, a first through conductor 20A, and a second through conductor 20B. The capacitor part 10 includes a first electrode layer 11, a second electrode layer 12, a dielectric layer 13, and a collector foil 14. The first electrode layer 11 and the second electrode layer 12 are opposite in the thickness direction with the dielectric layer 13 therebetween. The collector foil 14 is provided on the surface of the second electrode layer 12 on the reverse side from the dielectric layer 13 so as to be electrically connected to the second electrode layer 12. The first through conductor 20A: is provided at least at an inner wall surface of a first through hole 50A that passes through the capacitor part 10 in the thickness direction; and is electrically connected to the first electrode layer 11. The second through conductor 20B: is provided at least at an inner wall surface of a second through hole 50B that passes through the capacitor part 10 in the thickness direction; and is electrically connected to the second electrode layer 12. When the thickness of the collector foil 14 is Y and the center-to-center distance between the first through conductor 20A and the second through conductor 20B is P, Y / P is 0.005–0.25.

Description

Capacitor element

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

[0002] Patent Document 1 discloses an electrode foil for a solid electrolytic capacitor, which includes a metal foil having a first portion where a solid electrolyte layer is formed and a second portion where the solid electrolyte layer is not formed, wherein the metal foil has, at least in the first portion, a porous portion and a core portion continuous with the porous portion, and the area ratio of the core portion in a cross section parallel to the thickness direction of the first portion is 40% or more.

[0003] Furthermore, Patent Document 1 discloses a solid electrolytic capacitor element including the above-mentioned electrode foil for a solid electrolytic capacitor as an anode foil, a dielectric layer formed on at least a part of the surface of the anode foil, and a cathode part covering at least a part of the dielectric layer, wherein the cathode part includes at least the solid electrolyte layer covering at least a part of the dielectric layer in the first part.

[0004] Patent Document 2 discloses a capacitor array including multiple solid electrolytic capacitor elements formed by dividing a single solid electrolytic capacitor sheet, a sheet-like first sealing layer, and a sheet-like second sealing layer. The solid electrolytic capacitor sheet includes an anode plate made of a valve metal, a porous layer provided on at least one main surface of the anode plate, a dielectric layer provided on the surface of the porous layer, and a cathode layer including a solid electrolyte layer provided on the surface of the dielectric layer, and has first and second main surfaces opposing each other in the thickness direction. The first main surface side of each of the multiple solid electrolytic capacitor elements is disposed on the first sealing layer. The second sealing layer is disposed so as to cover the multiple solid electrolytic capacitor elements on the first sealing layer from the second main surface side. The solid electrolytic capacitor elements are separated by slit-shaped sheet removal portions.

[0005] International Publication No. 2023 / 032603 Japanese Patent Application Laid-Open No. 2020-167361

[0006] Patent Document 1 describes that the equivalent series resistance (ESR) of a solid electrolytic capacitor can be reduced by making the area ratio of the core in the cross section of the metal foil that constitutes the electrode foil for a solid electrolytic capacitor 40% or more.

[0007] On the other hand, Patent Document 2 describes that it is preferable to provide a through electrode that penetrates the first sealing layer or the second sealing layer in the thickness direction, and that the anode plate or the cathode layer is connected to an external electrode via the through electrode. Patent Document 2 also describes that a metal foil (hereinafter referred to as a current collecting foil) may be used as the cathode layer.

[0008] In a solid electrolytic capacitor element such as that described in Patent Document 2, when considering the path along which current flows from the through electrode connected to the anode plate through the inside of the capacitor element to the through electrode connected to the current collecting foil, for example, the interface resistance between the through electrode and the current collecting foil and the volume resistance of the current collecting foil are essentially expressed as path resistance.

[0009] For example, by increasing the number of through electrodes (hereinafter referred to as through conductors) connected to the same capacitor element, the resistance between the through conductors can be reduced by the parallel effect. However, from the perspective of reducing the resistance in the portion passing from the through conductor through the current collecting foil, there is still room for improvement.

[0010] The above problem is not limited to solid electrolytic capacitor elements including anode plates, but is a problem common to all capacitor elements.

[0011] The present invention has been made to solve the above problems, and has an object to provide a capacitor element that can reduce the resistance in the portion from the through conductor through the current collecting foil.

[0012] The capacitor element of the present invention includes a capacitor unit, a first through conductor, and a second through conductor. The capacitor unit includes a first electrode layer, a second electrode layer, a dielectric layer, and a current collecting foil. The first electrode layer and the second electrode layer face each other in the thickness direction via the dielectric layer. The current collecting foil is provided on a surface of the second electrode layer opposite the dielectric layer so as to be electrically connected to the second electrode layer. The first through conductor is provided on at least an inner wall surface of a first through hole that penetrates the capacitor unit in the thickness direction and is electrically connected to the first electrode layer. The second through conductor is provided on at least an inner wall surface of a second through hole that penetrates the capacitor unit in the thickness direction and is electrically connected to the second electrode layer. When the thickness of the current collecting foil is Y and the center-to-center distance between the first through conductor and the second through conductor is P, a ratio Y / P is 0.005 to 0.25.

[0013] According to the present invention, it is possible to provide a capacitor element that can reduce the resistance of the portion that runs from the through conductor through the current collecting foil.

[0014] FIG. 1 is a plan view schematically showing an example of a capacitor element of the present invention. FIG. 2 is an enlarged plan view of a portion indicated by II in the capacitor element shown in FIG. 1. FIG. 3 is an example of a cross-sectional view taken along line III-III of the capacitor element shown in FIG. 2. FIG. 4 is an example of a plan view taken along line IV-IV of the capacitor element shown in FIG. 3. FIG. 5 is an example of a graph showing the relationship between the center-to-center distance P of the through conductors and the resistance between the through conductors for each thickness Y of the current collecting foil. FIG. 6 is an example of a graph showing the relationship between the ratio Y / P and the resistance between the through conductors. FIG. 7 is an example of a graph showing the capacitance C per unit versus the center-to-center distance p between the first through conductor and the second through conductor. ｕｎｉｔ11 is a plan view illustrating an example of the arrangement of the first through conductors and the second through conductors. FIG. 9 is a plan view illustrating an example of the arrangement shown in FIG. 8. FIG. 10 is a plan view illustrating another example of the arrangement shown in FIG. 8. FIG. 11 is a plan view illustrating another example of the arrangement of the first through conductors and the second through conductors. FIG. 12 is a plan view illustrating an example of the arrangement shown in FIG. 11. FIG. 13 is a plan view illustrating another example of the arrangement shown in FIG. 11. FIG. 14 is a plan view illustrating an example of a capacitor unit in the arrangement shown in FIG. 8. FIG. 15 is a plan view illustrating an example of a capacitor unit in the arrangement shown in FIG. 11.

[0015] The capacitor element of the present invention will be described below. Note that the present invention is not limited to the following embodiments and may be modified as appropriate within the scope of the present invention. Furthermore, a combination of multiple individual preferred configurations described in the following embodiments also constitutes the present invention.

[0016] In this specification, terms indicating the relationship between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms indicating the shapes of elements are not expressions that only express a strict meaning, but are expressions that mean that a range of substantial equivalence, for example, a difference of about a few percent, is also included. Furthermore, in this specification, "equivalent" or "constant" is not an expression that means only completely equivalent or constant, but is an expression that means that a range of substantial equivalence or constant, for example, a difference of about a few percent, is included.

[0017] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0018] Fig. 1 is a plan view schematically showing an example of a capacitor element of the present invention, and Fig. 2 is an enlarged plan view of a portion indicated by II in the capacitor element shown in Fig. 1.

[0019] The capacitor element 1 shown in FIGS. 1 and 2 includes a capacitor section 10, a first through conductor 20A, and a second through conductor 20B.

[0020] Fig. 3 is an example of a cross-sectional view taken along line III-III of the capacitor element shown in Fig. 2. Fig. 1 is an example of a plan view taken along line II of the capacitor element shown in Fig. 3. Fig. 4 is an example of a plan view taken along line IV-IV of the capacitor element shown in Fig. 3.

[0021] In the example shown in Figure 3, the capacitor element 1 further includes a sealing layer 30, a first conductor wiring layer 40A, and a second conductor wiring layer 40B in addition to the capacitor section 10, the first through conductor 20A, and the second through conductor 20B.

[0022] The capacitor unit 10 includes a first electrode layer 11, a second electrode layer 12, a dielectric layer 13, and a current collecting foil 14. The first electrode layer 11 and the second electrode layer 12 face each other in the thickness direction (the vertical direction in FIG. 3 ) with the dielectric layer 13 interposed therebetween. For example, when the first electrode layer 11 is an anode plate and the second electrode layer 12 is a cathode layer, the capacitor unit 10 constitutes an electrolytic capacitor.

[0023] The first electrode layer 11 has, for example, a metal substrate 11A. The metal substrate 11A of the first electrode layer 11 is, for example, the core of an anode plate. As shown in FIG. 3 , the first electrode layer 11 preferably further has a porous portion 11B provided on at least one main surface of the metal substrate 11A. In the example shown in FIG. 3 , the porous portion 11B is provided on both main surfaces of the metal substrate 11A, but the porous portion 11B may be provided on only one of the main surfaces of the metal substrate 11A. A dielectric layer 13 is provided on the surface of the porous portion 11B, and a second electrode layer 12 is provided on the surface of the dielectric layer 13.

[0024] The second electrode layer 12 includes, for example, a solid electrolyte layer provided on the surface of the dielectric layer 13. In this case, it is preferable that a current collecting foil 14 is provided on at least a portion of the surface of the solid electrolyte layer constituting the second electrode layer 12. When the second electrode layer 12 includes a solid electrolyte layer, the capacitor unit 10 constitutes a solid electrolytic capacitor.

[0025] The current collecting foil 14 is provided on the surface of the second electrode layer 12 opposite to the dielectric layer 13 so as to be electrically connected to the second electrode layer 12. As shown in Fig. 3, the current collecting foil 14 preferably extends from the surface of the second electrode layer 12 to the outside of the second electrode layer 12.

[0026] The current collector foil 14 preferably contains a metal. For example, the current collector foil 14 may be a metal foil or a metallized film in which a metal layer is provided on the surface of a film.

[0027] Examples of metals that can be used to form the current collector foil 14 include copper, aluminum, gold, platinum, silver, titanium, nickel, and alloys containing at least one of these metals. Among these, the metal that can be used to form the current collector foil 14 is preferably copper or aluminum.

[0028] As shown in FIG. 3 , the first through conductor 20A is provided on at least the inner wall surface of the first through hole 50A that penetrates the capacitor unit 10 in the thickness direction. That is, the first through conductor 20A may be provided only on the inner wall surface of the first through hole 50A, or may be provided throughout the entire interior of the first through hole 50A. When the first through conductor 20A is provided only on the inner wall surface of the first through hole 50A, the space surrounded by the first through conductor 20A within the first through hole 50A may be filled with a material containing resin. That is, a first resin filling portion 25A may be provided inside the first through conductor 20A. In the example shown in FIG. 3 , the first through conductor 20A is provided on the inner wall surface of the first through hole 50A that penetrates the sealing layer 30 and the capacitor unit 10 in the thickness direction.

[0029] As shown in FIGS. 1 and 2, the first through conductor 20A preferably exists within the second electrode layer 12 when viewed in plan in the thickness direction of the capacitor element 1.

[0030] 3, the first through conductor 20A is electrically connected to the first electrode layer 11. In the example shown in FIG. 3, the first through conductor 20A is connected at its end to a first conductor wiring layer 40A provided on the surface of the sealing layer 30.

[0031] 3, the first through conductor 20A is preferably electrically connected to the first electrode layer 11 on the inner wall surface of the first through hole 50A. More specifically, the first through conductor 20A is preferably electrically connected to the end surface of the first electrode layer 11 that faces the inner wall surface of the first through hole 50A in a planar direction perpendicular to the thickness direction (the left-right direction in FIG. 3). In this case, no insulating material such as the sealing layer 30 is filled between the end surface of the first electrode layer 11 and the first through conductor 20A.

[0032] 3, the metal base 11A and the porous portion 11B are preferably exposed at the end face of the first electrode layer 11 electrically connected to the first through conductor 20A. In this case, the porous portion 11B as well as the metal base 11A are electrically connected to the first through conductor 20A.

[0033] The first through conductor 20A may be electrically connected to the end surface of the first electrode layer 11 via an anode connection layer, or may be directly connected to the end surface of the first electrode layer 11 .

[0034] When viewed in the thickness direction of the capacitor element 1, the first through conductor 20A is preferably provided around the entire periphery of the first through hole 50A as shown in Fig. 4. In particular, when viewed in the thickness direction of the capacitor element 1, the first through conductor 20A is preferably electrically connected to the first electrode layer 11 around the entire periphery of the first through hole 50A.

[0035] As shown in FIG. 3 , the second through conductor 20B is provided on at least the inner wall surface of the second through hole 50B that penetrates the capacitor unit 10 in the thickness direction. That is, the second through conductor 20B may be provided only on the inner wall surface of the second through hole 50B, or may be provided throughout the entire interior of the second through hole 50B. When the second through conductor 20B is provided only on the inner wall surface of the second through hole 50B, the space surrounded by the second through conductor 20B within the second through hole 50B may be filled with a material containing resin. That is, a second resin filling portion 25B may be provided inside the second through conductor 20B. In the example shown in FIG. 3 , the second through conductor 20B is provided on the inner wall surface of the second through hole 50B that penetrates the sealing layer 30 and the capacitor unit 10 in the thickness direction.

[0036] As shown in FIGS. 1 and 2, the second through conductor 20B preferably exists within the second electrode layer 12 when viewed in plan in the thickness direction of the capacitor element 1.

[0037] 3, the second through conductor 20B is electrically connected to the second electrode layer 12. In the example shown in FIG. 3, the second through conductor 20B is connected at its end to a second conductor wiring layer 40B provided on the surface of the sealing layer 30.

[0038] 3, the second through conductor 20B is preferably electrically connected to the inner wall surface of the second through hole 50B of the current collector foil 14. More specifically, the second through conductor 20B is preferably electrically connected to the end surface of the current collector foil 14 that faces the inner wall surface of the second through hole 50B in a planar direction perpendicular to the thickness direction (the left-right direction in FIG. 3).

[0039] On the other hand, it is preferable that an insulating material such as a sealing layer 30 is filled between the end face of the first electrode layer 11 and the second through conductor 20B.

[0040] When viewed in the thickness direction of the capacitor element 1, the second penetrating conductor 20B is preferably provided around the entire periphery of the second through hole 50B as shown in Fig. 4. In particular, when viewed in the thickness direction of the capacitor element 1, the second penetrating conductor 20B is preferably electrically connected to the current collecting foil 14 around the entire periphery of the second through hole 50B.

[0041] 3, a fragment of the current collector foil 14 electrically insulated from the second electrode layer 12 may be present around the first through conductor 20A. Note that the current collector foil 14 electrically insulated from the second electrode layer 12 does not necessarily have to be present around the first through conductor 20A.

[0042] The sealing layer 30 is provided so as to cover the capacitor section 10. The sealing layer 30 protects the capacitor section 10.

[0043] As shown in FIG. 3, the sealing layer 30 is preferably provided on both main surfaces of the capacitor section 10 that face each other in the thickness direction.

[0044] As shown in FIGS. 2 and 3, the capacitor section 10 may further include an insulating layer 35 provided on at least one main surface of the first electrode layer 11 around the first through conductor 20A or the second through conductor 20B.

[0045] The insulating layer 35 provided around the first through conductor 20A or the second through conductor 20B may be composed of only one layer, or may be composed of two or more layers. When the insulating layer 35 is composed of two or more layers, the materials constituting each layer may be the same or different.

[0046] As shown in FIG. 2 , the capacitor section 10 may further include an insulating layer 35 provided on at least one main surface of the first electrode layer 11 so as to surround the periphery of the second electrode layer 12 .

[0047] The insulating layer 35 provided to surround the periphery of the second electrode layer 12 may be composed of only one layer, or may be composed of two or more layers. When the insulating layer 35 is composed of two or more layers, the materials constituting each layer may be the same or different. The number of insulating layers 35 provided to surround the periphery of the second electrode layer 12 may be the same as or different from the number of insulating layers 35 provided around the first through conductor 20A or the second through conductor 20B.

[0048] For example, an insulating adhesive layer may be provided between the insulating layer 35 and the current collector foil 14. Furthermore, when an insulating material is filled between the end face of the first electrode layer 11 and the second through conductor 20B, an insulating adhesive layer may also be provided between the insulating material and the current collector foil 14.

[0049] The insulating adhesive layer is made of an insulating material. In this case, the insulating adhesive layer preferably contains an insulating resin. For example, a B-stage adhesive is used as the insulating adhesive layer.

[0050] The first conductor wiring layer 40A is provided on the surface of the sealing layer 30 and is electrically connected to the first through conductor 20A. In the example shown in Fig. 3, the first conductor wiring layer 40A is provided on the surface of the first through conductor 20A and functions as a connection terminal of the capacitor section 10.

[0051] Specifically, in the example shown in FIG. 3, the first conductor wiring layer 40A is electrically connected to the first electrode layer 11 via the first through conductor 20A and functions as a connection terminal for the first electrode layer 11.

[0052] The second conductor wiring layer 40B is provided on the surface of the sealing layer 30 and is electrically connected to the second through conductor 20B. In the example shown in Fig. 3, the second conductor wiring layer 40B is provided on the surface of the second through conductor 20B and functions as a connection terminal of the capacitor section 10.

[0053] Specifically, in the example shown in Figure 3, the second conductor wiring layer 40B is electrically connected to the second electrode layer 12 via the second through conductor 20B and the current collecting foil 14, and functions as a connection terminal for the second electrode layer 12.

[0054] As shown in Figure 3, the capacitor element 1 is characterized in that when the thickness of the collecting foil 14 is Y and the center-to-center distance between the first through conductor 20A and the second through conductor 20B is P, the ratio Y / P is 0.005 or more and 0.25 or less.

[0055] Fig. 5 is an example of a graph showing the relationship between the center-to-center distance P of the through conductors and the resistance between the through conductors for each thickness Y of the current collecting foil. Fig. 6 is an example of a graph showing the relationship between the Y / P ratio and the resistance between the through conductors. The vertical axes of Fig. 5 and Fig. 6 show the DC resistance (Rdc) between the through conductors after all the parallel connections.

[0056] From Figure 5, it can be seen that the resistance between the through conductors, i.e., the resistance between the first through conductor and the second through conductor, increases as the thickness Y of the collecting foil decreases, and also tends to increase within a certain range of the center-to-center distance P between the first through conductor and the second through conductor.

[0057] Therefore, in an arrangement in which the center-to-center distance P between the first and second penetrating conductors is within a specific range, or in a configuration in which the thickness Y of the current collecting foil is within a specific range, the resistance between the penetrating conductors can be reduced by setting the ratio Y / P to be 0.005 or more and 0.25 or less, as shown in Figure 6. As a result, it is thought that the resistance in the portion passing from the penetrating conductor through the current collecting foil can be reduced.

[0058] When a target value for the resistance between the through conductors is set in the capacitor element 1, it appears that the options available for lowering the resistance between the through conductors are (a) increasing the thickness Y of the current collecting foil, or (b) increasing the center-to-center distance P of the through conductors. However, in reality, increasing the center-to-center distance P of the through conductors reduces the overall capacitance of the capacitor element 1, as shown in Figure 7 below. Therefore, controlling the resistance between the through conductors by the thickness Y of the current collecting foil is appropriate for the overall design. On the other hand, when the thickness Y of the current collecting foil is increased, it is necessary to consider the design of the overall thickness of the capacitor element 1 and the changes in the thermal properties (especially elongation) that occur due to a relative increase in the volume proportion occupied by metal.

[0059] From the above, when consideration is given to the capacitance design, resistance design, thermal design, etc. of the entire capacitor element 1, a more advantageous design can be achieved by setting the relationship between the center-to-center distance P of the through conductors and the thickness Y of the current collecting foil, i.e., the ratio Y / P, within a specific range, as shown in Figure 6.

[0060] When the thickness of the current collecting foil 14 is Y and the center-to-center distance between the first through conductor 20A and the second through conductor 20B is P, it is preferable that the ratio Y / P is 0.005 or more and 0.20 or less.

[0061] In this specification, the center of a through conductor refers to the center of the smallest circle that contains the through conductor when viewed from above in the thickness direction of the capacitor element. Therefore, the center-to-center distance between a first through conductor and a second through conductor refers to the length of a line segment connecting the centers of the first through conductor and the second through conductor, as determined by the above method. The same applies to the center-to-center distance between the first through conductor and the first through conductor, and the center-to-center distance between the second through conductor and the second through conductor, which will be described later.

[0062] The thickness Y of the current collector foil 14 is preferably 0.005 mm or more and 0.1 mm or less, and more preferably 0.01 mm or more and 0.05 mm or less.

[0063] As shown in FIG. 3, when the thickness of the metal substrate 11A is X, the thickness X of the metal substrate 11A is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 60 μm or less.

[0064] In the capacitor element 1 shown in Fig. 1 etc., it is preferable that a plurality of capacitor units 1U are arranged in a planar direction perpendicular to the thickness direction (a direction parallel to the paper surface in Fig. 2) as shown in Fig. 2. In this case, the number of capacitor units 1U included in the capacitor element 1 is not particularly limited as long as it is two or more.

[0065] As shown in FIG. 2, each of the capacitor units 1U includes a capacitor section 10, a first through conductor 20A, and a second through conductor 20B.

[0066] When the capacitor element 1 includes a plurality of capacitor units 1U, it is preferable that the configuration of the capacitor section 10 be the same among the capacitor units 1U.

[0067] Adjacent capacitor sections 10 between capacitor units 1U may or may not be separated by a through groove. When adjacent capacitor sections 10 between capacitor units 1U are separated by a through groove, the adjacent capacitor sections 10 only need to be physically separated. Therefore, adjacent capacitor sections 10 may be electrically separated or electrically connected. For example, a combination of electrically separated capacitor sections 10 and electrically connected capacitor sections 10 may be present.

[0068] As shown in FIG. 4, in a plan view from the thickness direction of the capacitor element 1, the area of ​​the capacitor unit 1U, the diameter of the first through hole 50A (D ＴＨ１ the length indicated by D in FIG. 4 ), the area of ​​the first through conductor 20A in the first through hole 50A, the diameter of the second through hole 50B (D ＴＨ２ It is preferable that the area of ​​the second through conductor 20B in the second through hole 50B, and the center-to-center distance between the first through conductor 20A and the second through conductor 20B (the length indicated by P in Figure 4) are the same among the capacitor units 1U.

[0069] In this specification, the diameter of a through hole means the diameter when the planar shape is circular, and means the equivalent circle diameter when the planar shape is other than circular.

[0070] It is preferable that the shapes of the capacitor units 1U are the same among the capacitor units 1U when viewed in a plan view from the thickness direction of the capacitor element 1.

[0071] When viewed from above in the thickness direction of the capacitor element 1, the shapes of the first through conductors 20A constituting the capacitor units 1U are preferably the same among the capacitor units 1U.

[0072] In plan view from the thickness direction of the capacitor element 1, the shapes of the second through conductors 20B constituting the capacitor units 1U are preferably the same among the capacitor units 1U.

[0073] In the same capacitor unit 1U, the diameter of the first through hole 50A may be different from the diameter of the second through hole 50B, but is preferably equal to the diameter of the second through hole 50B. Therefore, in all capacitor units 1U, the diameter of the first through hole 50A is preferably equal to the diameter of the second through hole 50B.

[0074] In the same capacitor unit 1U, the area of ​​the first through conductor 20A in the first through hole 50A may be different from the area of ​​the second through conductor 20B in the second through hole 50B, but is preferably equal to the area of ​​the second through conductor 20B in the second through hole 50B. Therefore, in all capacitor units 1U, the area of ​​the first through conductor 20A in the first through hole 50A is preferably equal to the area of ​​the second through conductor 20B in the second through hole 50B.

[0075] In the capacitor element 1, the capacitance C per unit for the center distance p between the first through conductor and the second through conductor is calculated from the virtual unit by the methods shown in (1) and (2) below. ｕｎｉｔ When the correlation is calculated, the capacitance C per unit calculated from the virtual unit is ｕｎｉｔ The center distance P when is at its maximum value ０is different from the center distance P in the capacitor unit 1U, and the center distance P ０ The total number of virtual units n corresponding to the capacitance C per unit ｕｎｉｔ It is preferable that the actual total capacitance, which corresponds to the capacitance of the total area of ​​the capacitor unit 1U out of the capacitance of the entire capacitor element 1, is larger than the virtual total capacitance obtained by multiplying the maximum value of

[0076] (1) In the capacitor unit 1U, the area of ​​the first through conductor 20A in the first through hole 50A is S ＴＨ１ , the area of ​​the second through conductor 20B in the second through hole 50B is S ＴＨ２ When the total number of capacitor units 1U included in capacitor element 1 is N, it is assumed that a virtual unit that satisfies all of the following conditions 1 to 4 is included in capacitor element 1 instead of capacitor unit 1U.

[0077] Condition 1: The total number of virtual units included in capacitor element 1 is n.

[0078] Condition 2: When viewed in a plane from the thickness direction of the capacitor element 1, the area of ​​the virtual unit, the diameter of the first through hole, the area of ​​the first through conductor in the first through hole, the diameter of the second through hole, the area of ​​the second through conductor in the second through hole, and the center-to-center distance between the first through conductor and the second through conductor are the same between the virtual units.

[0079] It is preferable that the shapes of the virtual units are the same among the virtual units when viewed from above in the thickness direction of the capacitor element 1.

[0080] In plan view from the thickness direction of the capacitor element 1, the shapes of the first through conductors constituting the virtual units are preferably the same among the virtual units.

[0081] In plan view from the thickness direction of the capacitor element 1, the shapes of the second through conductors constituting the virtual units are preferably the same among the virtual units.

[0082] In the same virtual unit, the diameter of the first through hole may be different from the diameter of the second through hole, but is preferably equal to the diameter of the second through hole. Therefore, in all virtual units, the diameter of the first through hole is preferably equal to the diameter of the second through hole.

[0083] In the same virtual unit, the area of ​​the first through conductor in the first through hole may be different from the area of ​​the second through conductor in the second through hole, but is preferably equal to the area of ​​the second through conductor in the second through hole. Therefore, in all virtual units, the area of ​​the first through conductor in the first through hole is preferably equal to the area of ​​the second through conductor in the second through hole.

[0084] Condition 3: The area of ​​the first through conductor in the first through hole of the virtual unit is s ＴＨ１ , the area of ​​the second through conductor in the second through hole is s ＴＨ２ is.

[0085] Condition 4: (s ＴＨ１ +s ＴＨ２ ) × n is (S ＴＨ１ +S ＴＨ２ ) × N.

[0086] (2) From the above virtual unit, the capacitance C per unit for the center distance p between the first through conductor and the second through conductor is calculated. ｕｎｉｔ Calculate the correlation.

[0087] Since the occupied area of ​​the capacitor element 1 is constant, in the virtual unit, (s ＴＨ１ +s ＴＨ２ ) × n is (S ＴＨ１ +S ＴＨ２ The area of ​​the virtual unit, the diameter of the first through hole, and the diameter of the second through hole are determined according to the center-to-center distance p between the first through conductor and the second through conductor so that the capacitance C per unit is equal to the value of ｕｎｉｔ is required.

[0088] Furthermore, the total number n of virtual units corresponding to the center distance p is expressed as the capacitance C per unit. ｕｎｉｔ By multiplying this, the virtual total capacity can be calculated.

[0089] FIG. 7 shows the capacitance C per unit versus the center distance p between the first through conductor and the second through conductor. ｕｎｉｔ 10 is an example of a graph showing the correlation of the total capacitance of a capacitor element.

[0090] As shown in FIG. 7, the capacitance C ｕｎｉｔ The center distance P when is at its maximum value ０ is the center distance P when the total capacitance of the capacitor element is at its maximum value. １ It is clear that it does not match.

[0091] As described above, in the capacitor element 1, the capacitance C per unit ｕｎｉｔ The center distance P when is at its maximum value ０ is different from the center distance P in the capacitor unit 1U, and the center distance P ０ The total number of virtual units n corresponding to the capacitance C per unit ｕｎｉｔ It is preferable that the actual total capacitance, which corresponds to the capacitance of the total area of ​​the capacitor unit 1U out of the capacitance of the entire capacitor element 1, is larger than the virtual total capacitance obtained by multiplying the maximum value of

[0092] Here, the capacitance of the entire capacitor element 1 is C ｔｏｔａｌ , the total area of ​​the capacitor unit 1U (i.e., the area of ​​the capacitor unit 1U x N) is S １ , the area of ​​the entire capacitor element 1 is S ２ Then, the actual total capacity C is C = C ｔｏｔａｌ ×S １ / S ２ The total area of ​​the capacitor unit 1U is defined as S １ is the area S of the entire capacitor element 1 ２ In some cases, it is the same as the area S of the entire capacitor element 1. ２ Therefore, the substantial total capacitance of the capacitor element 1 may not coincide with the capacitance of the entire capacitor element 1. For example, in FIG. 13 described below, the capacitance of the portion located outside the first unit 1UA, which is part of the capacitor unit 1U, is not included in the substantial total capacitance.

[0093] In the example shown in FIG. 7, the capacitance C ｕｎｉｔ The center distance P when is at its maximum value ０ The total number of virtual units n corresponding to the capacitance C per unit ｕｎｉｔ The virtual total capacity obtained by multiplying the maximum value of ０ Therefore, in the capacitor element 1, C ０ For example, in the capacitor element 1, the capacitance shown in FIG. １ , C ２ or C ３ It is preferable that the capacitance shown by C is the substantial total capacitance. ４ or C ５ It is preferable that the capacitance indicated by is not substantially the total capacitance.

[0094] In the above case, in the capacitor element 1, the overall capacitance can be increased relative to the amount of conductor of the through conductor required depending on the amount of current.

[0095] The center distance P in the capacitor unit 1U is the center distance P when the substantial overall capacitance is at its maximum value. １ It is more preferable that:

[0096] 8 is a plan view schematically showing an example of the arrangement of the first through conductors and the second through conductors, taken at the same position as in FIG. 4 (the position of line IV-IV in FIG. 3).

[0097] In the capacitor element 1A shown in Fig. 8, the first through conductors 20A and the second through conductors 20B are arranged in a square as a whole. In the square arrangement, the first through conductors 20A or the second through conductors 20B are arranged at each vertex of the square. In the example shown in Fig. 8, the first through conductors 20A and the second through conductors 20B are arranged alternately from top to bottom, and the first through conductors 20A and the second through conductors 20B are arranged alternately from left to right.

[0098] FIG. 9 is a plan view for explaining an example of the arrangement shown in FIG.

[0099] In FIG. 9, the capacitor unit 1U includes a first unit 1UA and a second unit 1UB adjacent to the first unit 1UA.

[0100] As shown in Figure 9, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the center-to-center distance between the first through conductor 20A of the first unit 1UA and the second through conductor 20B of the first unit 1UA is equal to the center-to-center distance between the first through conductor 20A of the first unit 1UA and the second through conductor 20B of the second unit 1UB.

[0101] 9, forming a current path in parallel with the capacitor element 1A can reduce the equivalent series resistance and equivalent series inductance. Furthermore, equalizing the center-to-center distance between the first through conductor 20A and the second through conductor 20B can reduce the impedance difference between the current paths. It can also distribute heat generated by the capacitor element 1A and increase the current capacity.

[0102] As shown in Figure 9, the capacitor unit 1U further includes a third unit 1UC adjacent to the first unit 1UA, and when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB is equal to the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the third unit 1UC.

[0103] 9 , in a plan view from the thickness direction of the capacitor element 1A, the second Through conductor 20B of the third unit 1UC preferably exists on a straight line obtained by rotating a line segment connecting the center of the second Through conductor 20B of the first unit 1UA and the center of the second Through conductor 20B of the second unit 1UB by an angle of 90 degrees or 180 degrees around the center of the second Through conductor 20B of the first unit 1UA. In this case, it is sufficient that the smallest circle that contains the second Through conductor 20B of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the second Through conductor 20B of the first unit 1UA and the center of the second Through conductor 20B of the second unit 1UB by an angle of 90 degrees or 180 degrees around the center of the second Through conductor 20B of the first unit 1UA.

[0104] In the example shown in Figure 9, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the number of second through conductors 20B present within a circle whose radius is the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB and whose center is the center of the first through conductor 20A of the first unit 1UA is the same as the number of second through conductors 20B present within a circle whose radius is the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB and whose center is the center of the first through conductor 20A of the second unit 1UB.

[0105] As shown in FIG. 9, by arranging capacitor units 1U evenly and in parallel on the evenly arranged current paths, the noise removal effect can be improved.

[0106] In particular, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the difference between the total area of ​​the second through conductors 20B that overlap with a circle whose radius is the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB and whose center is the center of the first through conductor 20A of the first unit 1UA, and the total area of ​​the second through conductors 20B that exist within a circle whose radius is the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB and whose center is the center of the first through conductor 20A of the second unit 1UB, is within ±5%.

[0107] FIG. 10 is a plan view for explaining another example of the arrangement shown in FIG.

[0108] In FIG. 10, the capacitor unit 1U includes a first unit 1UA and a second unit 1UB adjacent to the first unit 1UA.

[0109] As shown in Figure 10, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the center-to-center distance between the second through conductor 20B of the first unit 1UA and the first through conductor 20A of the first unit 1UA is equal to the center-to-center distance between the second through conductor 20B of the first unit 1UA and the first through conductor 20A of the second unit 1UB.

[0110] 10, by forming a current path in parallel with the capacitor element 1A, the equivalent series resistance and equivalent series inductance can be reduced. Furthermore, by equalizing the center-to-center distance between the first through conductor 20A and the second through conductor 20B, the impedance difference between the current paths can be reduced. In addition, the heat generated by the capacitor element 1A can be dispersed, and the current capacity can be increased.

[0111] As shown in Figure 10, the capacitor unit 1U further includes a third unit 1UC adjacent to the first unit 1UA, and when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB is equal to the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the third unit 1UC.

[0112] 10 , in a plan view from the thickness direction of the capacitor element 1A, the first Through conductor 20A of the third unit 1UC preferably exists on a straight line obtained by rotating a line segment connecting the center of the first Through conductor 20A of the first unit 1UA and the center of the first Through conductor 20A of the second unit 1UB by an angle of 90 degrees or 180 degrees around the center of the first Through conductor 20A of the first unit 1UA. In this case, it is sufficient that the smallest circle that contains the first Through conductor 20A of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the first Through conductor 20A of the first unit 1UA and the center of the first Through conductor 20A of the second unit 1UB by an angle of 90 degrees or 180 degrees around the center of the first Through conductor 20A of the first unit 1UA.

[0113] In the example shown in Figure 10, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the number of first through conductors 20A present within a circle whose radius is the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB and whose center is the center of the second through conductor 20B of the first unit 1UA is the same as the number of first through conductors 20A present within a circle whose radius is the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB and whose center is the center of the second through conductor 20B of the second unit 1UB.

[0114] As shown in FIG. 10, by arranging capacitor units 1U evenly and in parallel on the evenly arranged current paths, the noise removal effect can be improved.

[0115] In particular, when viewed in a plane from the thickness direction of the capacitor element 1A, it is preferable that the difference between the total area of ​​the first through conductors 20A that overlap with a circle whose radius is the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB and whose center is the center of the second through conductor 20B of the first unit 1UA, and the total area of ​​the first through conductors 20A that exist within a circle whose radius is the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB and whose center is the center of the second through conductor 20B of the second unit 1UB, is within ±5%.

[0116] Fig. 11 is a plan view schematically showing another example of the arrangement of the first through conductors and the second through conductors, taken at the same position as Fig. 4 (the position of line IV-IV in Fig. 3).

[0117] In the capacitor element 1B shown in Fig. 11, the first through conductors 20A and the second through conductors 20B are arranged in a hexagonal pattern as a whole. In the hexagonal pattern, the first through conductors 20A or the second through conductors 20B are arranged at each vertex of a regular hexagon and at the center of the regular hexagon. In the example shown in Fig. 11, the first through conductors 20A and the second through conductors 20B are arranged alternately from top to bottom. Note that when the first through conductors 20A and the second through conductors 20B are arranged in a hexagonal pattern as a whole, for example, the first through conductors 20A and the second through conductors 20B may be arranged alternately by two from top to bottom.

[0118] FIG. 12 is a plan view for explaining an example of the arrangement shown in FIG.

[0119] In FIG. 12, the capacitor unit 1U includes a first unit 1UA and a second unit 1UB adjacent to the first unit 1UA.

[0120] As shown in Figure 12, when viewed in a plane from the thickness direction of the capacitor element 1B, it is preferable that the center-to-center distance between the first through conductor 20A of the first unit 1UA and the second through conductor 20B of the first unit 1UA is equal to the center-to-center distance between the first through conductor 20A of the first unit 1UA and the second through conductor 20B of the second unit 1UB.

[0121] As shown in Figure 12, the capacitor unit 1U further includes a third unit 1UC adjacent to the first unit 1UA, and when viewed in a plane from the thickness direction of the capacitor element 1B, it is preferable that the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the second unit 1UB is equal to the center-to-center distance between the second through conductor 20B of the first unit 1UA and the second through conductor 20B of the third unit 1UC.

[0122] 12 , in a plan view from the thickness direction of the capacitor element 1B, the second Through conductor 20B of the third unit 1UC preferably exists on a straight line obtained by rotating a line segment connecting the center of the second Through conductor 20B of the first unit 1UA and the center of the second Through conductor 20B of the second unit 1UB at an angle of 60 degrees or 120 degrees around the center of the second Through conductor 20B of the first unit 1UA. In this case, it is sufficient that the smallest circle that contains the second Through conductor 20B of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the second Through conductor 20B of the first unit 1UA and the center of the second Through conductor 20B of the second unit 1UB at an angle of 60 degrees or 120 degrees around the center of the second Through conductor 20B of the first unit 1UA.

[0123] FIG. 13 is a plan view for explaining another example of the arrangement shown in FIG.

[0124] In FIG. 13, the capacitor unit 1U includes a first unit 1UA and a second unit 1UB adjacent to the first unit 1UA.

[0125] As shown in Figure 13, when viewed in a plane from the thickness direction of the capacitor element 1B, it is preferable that the center-to-center distance between the second through conductor 20B of the first unit 1UA and the first through conductor 20A of the first unit 1UA is equal to the center-to-center distance between the second through conductor 20B of the first unit 1UA and the first through conductor 20A of the second unit 1UB.

[0126] As shown in Figure 13, the capacitor unit 1U further includes a third unit 1UC adjacent to the first unit 1UA, and when viewed in a plane from the thickness direction of the capacitor element 1B, it is preferable that the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the second unit 1UB is equal to the center-to-center distance between the first through conductor 20A of the first unit 1UA and the first through conductor 20A of the third unit 1UC.

[0127] 13 , in a plan view from the thickness direction of the capacitor element 1B, the first Through conductor 20A of the third unit 1UC preferably exists on a straight line obtained by rotating a line segment connecting the center of the first Through conductor 20A of the first unit 1UA and the center of the first Through conductor 20A of the second unit 1UB at an angle of 60 degrees or 120 degrees around the center of the first Through conductor 20A of the first unit 1UA. In this case, it is sufficient that the smallest circle that contains the first Through conductor 20A of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the first Through conductor 20A of the first unit 1UA and the center of the first Through conductor 20A of the second unit 1UB at an angle of 60 degrees or 120 degrees around the center of the first Through conductor 20A of the first unit 1UA.

[0128] As shown in Figure 9 or Figure 12, when the capacitor unit 1U includes a third unit 1UC, it is preferable that, when viewed in a plane from the thickness direction of the capacitor element 1A or 1B, the second through conductor 20B of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the second through conductor 20B of the first unit 1UA and the center of the second through conductor 20B of the second unit 1UB at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the second through conductor 20B of the first unit 1UA.

[0129] As shown in Figure 10 or Figure 13, when the capacitor unit 1U includes a third unit 1UC, it is preferable that, when viewed in a plane from the thickness direction of the capacitor element 1A or 1B, the first through conductor 20A of the third unit 1UC exists on a straight line obtained by rotating a line segment connecting the center of the first through conductor 20A of the first unit 1UA and the center of the first through conductor 20A of the second unit 1UB at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the first through conductor 20A of the first unit 1UA.

[0130] FIG. 14 is a plan view showing an example of a capacitor unit in the arrangement shown in FIG.

[0131] As shown in Figure 14, when viewed in a plane from the thickness direction of the capacitor element 1A (see Figure 8), when the center-to-center distance between the first through conductor 20A and the second through conductor 20B is P, it is preferable that the area of ​​the capacitor unit 1U be expressed as 2P x P.

[0132] FIG. 15 is a plan view showing an example of a capacitor unit in the arrangement shown in FIG.

[0133] As shown in Figure 15, when viewed in a plane from the thickness direction of the capacitor element 1B (see Figure 11), when the center-to-center distance between the first through conductor 20A and the second through conductor 20B is P, it is preferable that the area of ​​the capacitor unit 1U be expressed as 2P × √3 / 2 × P.

[0134] The detailed configuration of the capacitor element 1, 1A or 1B will be described below.

[0135] Examples of the planar shape of capacitor unit 1U 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. Furthermore, the planar shape of capacitor unit 1U may be an L-shape, a C-shape, a stepped shape, etc.

[0136] The first electrode layer 11 is preferably an anode plate 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.

[0137] When the first electrode layer 11 is an anode plate, the shape of the anode plate is preferably a flat plate, and more preferably a foil. Thus, in this specification, the term "plate-like" includes "foil-like".

[0138] The first electrode layer 11 may have a porous portion 11B on at least one main surface of the metal base 11A. In this case, the first electrode layer 11 may have the porous portion 11B on only one main surface of the metal base 11A, or may have the porous portion 11B on both main surfaces of the metal base 11A. The porous portion 11B is preferably a porous layer formed on the surface of the metal base 11A, and more preferably an etched layer.

[0139] When the dielectric layer 13 is provided on the surface of the porous portion 11B, the dielectric layer 13 is porous, reflecting the surface condition of the porous portion 11B, and has a finely uneven surface shape. The dielectric layer 13 is preferably made of an oxide film of the valve metal. For example, when an aluminum foil is used as the first electrode layer 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).

[0140] 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.

[0141] The second electrode layer 12 is preferably a cathode layer including a solid electrolyte layer. In this case, examples of materials constituting the solid electrolyte layer 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 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.

[0142] The thickness of the solid electrolyte layer from the surface of the porous portion 11B is preferably 2 μm or more and 20 μm or less.

[0143] The solid electrolyte layer 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.

[0144] The solid electrolyte layer 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.

[0145] The first through conductor 20A is formed, for example, as follows. First, a first through hole 50A penetrating the sealing layer 30 and the capacitor unit 10 in the thickness direction is formed by processing such as drilling or laser processing. Then, the inner wall surface of the first through hole 50A is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the first through conductor 20A. When forming the first through conductor 20A, for example, metallizing the inner wall surface of the first through hole 50A by processing such as electroless copper plating or electrolytic copper plating facilitates processing. Note that, as a method for forming the first through conductor 20A, in addition to a method of metallizing the inner wall surface of the first through hole 50A, a method of filling the first through hole 50A with a metal material, a composite material of metal and resin, or the like may also be used.

[0146] The second through conductor 20B is formed, for example, as follows. First, a through hole penetrating the capacitor unit 10 in the thickness direction is formed by drilling, laser processing, or other processing. Next, an insulating material such as a sealing layer 30 is filled into the through hole. The portion filled with the insulating material is then processed by drilling, laser processing, or other processing to form the second through hole 50B. At this time, the diameter of the second through hole 50B is made smaller than the diameter of the through hole filled with the insulating material, so that the insulating material is present between the inner wall surface of the through hole filled with the insulating material and the inner wall surface of the second through hole 50B in the planar direction. Then, the inner wall surface of the second through hole 50B is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the second through conductor 20B. When forming the second through conductor 20B, for example, metallizing the inner wall surface of the second through hole 50B by a process such as electroless copper plating or electrolytic copper plating facilitates processing. In addition, as a method for forming the second through conductor 20B, in addition to the method of metallizing the inner wall surface of the second through hole 50B, a method of filling the second through hole 50B with a metal material, a composite material of metal and resin, etc. may also be used.

[0147] When the first resin filling portion 25A is provided inside the first through conductor 20A, the first resin filling portion 25A may be a conductor or an insulator. The material constituting the first resin filling portion 25A may have a thermal expansion coefficient larger than, smaller than, or the same as that of the material (e.g., copper) constituting the first through conductor 20A.

[0148] When the second resin filling portion 25B is provided inside the second through conductor 20B, the second resin filling portion 25B may be a conductor or an insulator. The material constituting the second resin filling portion 25B may have a thermal expansion coefficient larger than, smaller than, or the same as that of the material constituting the second through conductor 20B (e.g., copper).

[0149] The first through conductor 20A may be electrically connected to the end face of the first electrode layer 11 via an anode connection layer. In this case, the anode connection layer functions as a barrier layer for the first electrode layer 11. When the anode connection layer functions as a barrier layer for the first electrode layer 11, dissolution of the first electrode layer 11 that occurs during chemical treatment for forming a wiring layer (described later) is suppressed, and therefore, penetration of the chemical solution into the capacitor unit 10 is suppressed, which tends to improve reliability.

[0150] The anode connecting layer preferably includes a metal layer containing nickel as a main component, which reduces damage to the metal (e.g., aluminum) constituting the first electrode layer 11, and therefore the barrier properties of the anode connecting layer against the first electrode layer 11 are likely to be improved.

[0151] For example, an anode connecting layer including a metal layer mainly composed of nickel can be formed by performing a zincate treatment on the wall surface of the first electrode layer 11 made of aluminum or an aluminum alloy, followed by electroless nickel plating. The anode connecting layer may include, in order from the first electrode layer 11, a metal layer mainly composed of zinc and a metal layer mainly composed of nickel.

[0152] The first through conductor 20A may be connected directly to the end surface of the first electrode layer 11 without an anode connection layer therebetween.

[0153] The sealing layer 30 is made of an insulating material, and in this case, the sealing layer 30 is preferably made of an insulating resin.

[0154] Examples of insulating resins that form the sealing layer 30 include epoxy resins and phenolic resins.

[0155] Preferably, the sealing layer 30 further contains a filler.

[0156] Examples of the filler contained in the sealing layer 30 include inorganic fillers such as silica particles and alumina particles.

[0157] The sealing layer 30 may be composed of only one layer or two or more layers. When the sealing layer 30 is composed of two or more layers, the materials constituting the respective layers may be the same or different.

[0158] The sealing layer 30 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.

[0159] Between the capacitor section 10 and the sealing layer 30, for example, a stress relaxation layer, a moisture-proof film, or the like may be provided.

[0160] The insulating layer 35 is made of an insulating material, and in this case, the insulating layer 35 is preferably made of an insulating resin.

[0161] Examples of insulating resins that constitute the insulating layer 35 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.

[0162] The insulating layer 35 may be made of the same resin as the sealing layer 30. Unlike the sealing layer 30, if the insulating layer 35 contains an inorganic filler, it may adversely affect the effective capacitive portion of the capacitor section 10. Therefore, it is preferable that the insulating layer 35 be made of a resin alone.

[0163] The insulating layer 35 can be formed in a predetermined area by applying a mask material, such as a composition containing an insulating resin, to the surface of the porous portion 11B by a method such as sponge transfer, screen printing, dispenser application, or inkjet printing.

[0164] The insulating layer 35 may be formed on the porous portion 11B either before or after the dielectric layer 13 is formed.

[0165] Examples of the constituent material of the first conductor wiring layer 40A include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the first conductor wiring layer 40A is formed by, for example, plating the surface of the first through conductor 20A.

[0166] In order to improve the adhesion between the first conductor wiring layer 40A and other components, in this case, the adhesion between the first conductor wiring layer 40A and the first through conductor 20A, a mixed material of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as the constituent material of the first conductor wiring layer 40A.

[0167] Examples of materials constituting the second conductor wiring layer 40B include metal materials containing low-resistance metals such as silver, gold, copper, etc. In this case, the second conductor wiring layer 40B is formed by, for example, plating the surface of the second through conductor 20B.

[0168] In order to improve the adhesion between the second conductor wiring layer 40B and other components, in this case, the adhesion between the second conductor wiring layer 40B and the second through conductor 20B, a mixed material of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as the constituent material of the second conductor wiring layer 40B.

[0169] The constituent materials of the first conductor wiring layer 40A and the second conductor wiring layer 40B are preferably the same at least in terms of type, but may be different from each other.

[0170] When multiple capacitor sections 10 are arranged inside the sealing layer 30, each of the capacitor sections 10 may be provided with a first conductor wiring layer 40A electrically connected to the first electrode layer 11 and a second conductor wiring layer 40B electrically connected to the second electrode layer 12, or at least one of the first conductor wiring layer 40A and the second conductor wiring layer 40B may be provided in common among the multiple capacitor sections 10.

[0171] The capacitor element of the present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the configuration of the capacitor element, manufacturing conditions, and the like.

[0172] 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 electrodes (e.g., a first conductor wiring layer and a second conductor wiring layer) provided outside the sealing layer of the capacitor element and electrically connected to the first electrode layer and the second electrode layer of the capacitor section, respectively, and an electronic component connected to the external electrodes.

[0173] In a composite electronic component, the electronic component connected to the external electrode may be a passive element or an active element. Both the passive element and the active element may be connected to the external electrode, or either the passive element or the active element may be connected to the external electrode. Also, a composite of a passive element and an active element may be connected to the external electrode.

[0174] 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).

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] The present specification discloses the following:

[0181] <1> A capacitor element comprising: a capacitor unit, a first through conductor, and a second through conductor; the capacitor unit includes a first electrode layer, a second electrode layer, a dielectric layer, and a current collecting foil; the first electrode layer and the second electrode layer face each other in a thickness direction via the dielectric layer; the current collecting foil is provided on a surface of the second electrode layer opposite to the dielectric layer so as to be electrically connected to the second electrode layer; the first through conductor is provided on at least an inner wall surface of a first through hole that passes through the capacitor unit in the thickness direction, and is electrically connected to the first electrode layer; the second through conductor is provided on at least an inner wall surface of a second through hole that passes through the capacitor unit in the thickness direction, and is electrically connected to the second electrode layer; and when a thickness of the current collecting foil is Y and a center-to-center distance between the first through conductor and the second through conductor is P, a ratio of Y / P is 0.005 or more and 0.25 or less.

[0182] <2> The capacitor element according to <1>, wherein a plurality of capacitor units are arranged in a planar direction perpendicular to the thickness direction, and each of the capacitor units includes the capacitor portion, the first through conductor, and the second through conductor.

[0183] <3> In a plan view in the thickness direction of the capacitor element, the area of ​​the capacitor unit, the diameter of the first through hole, the area of ​​the first through conductor in the first through hole, the diameter of the second through hole, the area of ​​the second through conductor in the second through hole, and the center-to-center distance between the first through conductor and the second through conductor are all equivalent among the capacitor units, and the area of ​​the first through conductor in the first through hole of the capacitor unit is S ＴＨ１ , the area of ​​the second through conductor in the second through hole is S ＴＨ２ When the total number of the capacitor units included in the capacitor element is N, the capacitance C per unit for the center-to-center distance p between the first through conductor and the second through conductor is calculated from a hypothetical unit that satisfies all of the following conditions 1 to 4: ｕｎｉｔWhen the correlation between the above is obtained, Condition 1: the total number of the virtual units included in the capacitor element is n; Condition 2: in a plan view in the thickness direction of the capacitor element, the area of ​​the virtual unit, the diameter of the first through hole, the area of ​​the first through conductor in the first through hole, the diameter of the second through hole, the area of ​​the second through conductor in the second through hole, and the center-to-center distance between the first through conductor and the second through conductor are equivalent between the virtual units; Condition 3: the area of ​​the first through conductor in the first through hole of the virtual unit is s ＴＨ１ , the area of ​​the second through conductor in the second through hole is s ＴＨ２ Condition 4: (s ＴＨ１ +s ＴＨ２ ) × n is (S ＴＨ１ +S ＴＨ２ ) × N, the capacitance C per unit calculated from the virtual unit ｕｎｉｔ The center distance P when is at its maximum value ０ is different from the center distance P in the capacitor unit, and the center distance P ０ The total number n of the virtual units corresponding to the above is expressed as the capacitance C per unit. ｕｎｉｔ The capacitor element according to <2>, wherein the effective overall capacitance, which corresponds to the capacitance of the total area of ​​the capacitor units out of the capacitance of the entire capacitor element, is larger than the virtual overall capacitance obtained by multiplying the maximum value of

[0184] <4> The center-to-center distance P in the capacitor unit is the center-to-center distance P when the substantial overall capacitance is at its maximum value. １ The capacitor element according to <3>,

[0185] <5> The capacitor element according to any one of <1> to <4>, wherein the second through conductor is electrically connected to the current collector foil on an inner wall surface of the second through hole.

[0186] <6> The capacitor element according to <5>, wherein the second through conductor is electrically connected to the current collecting foil over the entire periphery of the second through hole.

[0187] <7> The capacitor element according to any one of <1> to <6>, wherein the current collecting foil contains a metal.

[0188] <8> The capacitor element according to any one of <1> to <7>, wherein the thickness of the current collector foil is 0.005 mm or more and 0.1 mm or less.

[0189] <9> The capacitor element according to any one of <1> to <8>, wherein the first electrode layer has a metal base and a porous portion provided on at least one main surface of the metal base, the dielectric layer is provided on a surface of the porous portion, and the second electrode layer is provided on a surface of the dielectric layer.

[0190] <10> The capacitor element according to <9>, wherein the second electrode layer includes a solid electrolyte layer provided on a surface of the dielectric layer.

[0191] <11> The capacitor element according to <3> or <4>, wherein the capacitor unit includes a first unit and a second unit adjacent to the first unit, and when viewed in a plane in the thickness direction of the capacitor element, the center-to-center distance between the first through conductor of the first unit and the second through conductor of the first unit is equal to the center-to-center distance between the first through conductor of the first unit and the second through conductor of the second unit.

[0192] <12> The capacitor element according to <11>, wherein the capacitor unit further includes a third unit adjacent to the first unit, and when viewed in a plan view in the thickness direction of the capacitor element, the center-to-center distance between the second through conductor of the first unit and the second through conductor of the second unit is equal to the center-to-center distance between the second through conductor of the first unit and the second through conductor of the third unit.

[0193] <13> The capacitor element according to <12>, wherein, in a planar view of the capacitor element in the thickness direction, the second through conductor of the third unit is located on a straight line obtained by rotating a line segment connecting the center of the second through conductor of the first unit and the center of the second through conductor of the second unit at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the second through conductor of the first unit.

[0194] <14> The capacitor element according to <3>, <4>, <11>, <12> or <13>, wherein the capacitor unit includes a first unit and a second unit adjacent to the first unit, and when viewed in a plan view in the thickness direction of the capacitor element, the center-to-center distance between the second through conductor of the first unit and the first through conductor of the first unit is equal to the center-to-center distance between the second through conductor of the first unit and the first through conductor of the second unit.

[0195] <15> The capacitor element according to <14>, wherein the capacitor unit further includes a third unit adjacent to the first unit, and when viewed in a plan view in the thickness direction of the capacitor element, the center-to-center distance between the first through conductor of the first unit and the first through conductor of the second unit is equal to the center-to-center distance between the first through conductor of the first unit and the first through conductor of the third unit.

[0196] <16> The capacitor element according to <15>, wherein, in a planar view of the capacitor element in the thickness direction, the first through conductor of the third unit is located on a straight line obtained by rotating a line segment connecting a center of the first through conductor of the first unit and a center of the first through conductor of the second unit at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the first through conductor of the first unit.

[0197] <17> The capacitor element according to any one of <11> to <16>, wherein the area of ​​the capacitor unit is expressed as 2P×P or 2P×√3 / 2×P in a plan view in the thickness direction of the capacitor element.

[0198] 1, 1A, 1B Capacitor element 1U Capacitor unit 1UA First unit 1UB Second unit 1UC Third unit 10 Capacitor section 11 First electrode layer 11A Metal base 11B Porous section 12 Second electrode layer 13 Dielectric layer 14 Current collecting foil 20 Through conductor 20A First through conductor 20B Second through conductor 25A First resin filling section 25B Second resin filling section 30 Sealing layer 35 Insulating layer 40A First conductor wiring layer 40B Second conductor wiring layer 50A First through hole 50B Second through hole D ＴＨ１ Diameter of the first through hole D ＴＨ２ Diameter of the second through hole: P; Center-to-center distance between the first through conductor and the second through conductor: X; Thickness of the metal substrate: X Ｔ Thickness of the first electrode layer Y Thickness of the current collecting foil

Claims

1. A capacitor element comprising: a capacitor section, a first through conductor, and a second through conductor; the capacitor section includes a first electrode layer, a second electrode layer, a dielectric layer, and a current collecting foil; the first electrode layer and the second electrode layer face each other in a thickness direction via the dielectric layer; the current collecting foil is provided on a surface of the second electrode layer opposite the dielectric layer so as to be electrically connected to the second electrode layer; the first through conductor is provided on at least the inner wall surface of a first through hole that passes through the capacitor section in the thickness direction, and is electrically connected to the first electrode layer; the second through conductor is provided on at least the inner wall surface of a second through hole that passes through the capacitor section in the thickness direction, and is electrically connected to the second electrode layer; and when the thickness of the current collecting foil is Y and the center-to-center distance between the first through conductor and the second through conductor is P, the ratio Y / P is 0.005 or more and 0.25 or less.

2. A capacitor element according to claim 1, wherein a plurality of capacitor units are arranged in a planar direction perpendicular to the thickness direction, and each of the capacitor units includes the capacitor portion, the first through conductor, and the second through conductor.

3. In a plan view from the thickness direction of the capacitor element, the area of ​​the capacitor unit, the diameter of the first through hole, the area of ​​the first through conductor in the first through hole, the diameter of the second through hole, the area of ​​the second through conductor in the second through hole, and the center-to-center distance between the first through conductor and the second through conductor are equivalent among the capacitor units, and the area of ​​the first through conductor in the first through hole of the capacitor unit is S ＴＨ１ , the area of ​​the second through conductor in the second through hole is S ＴＨ２ When the total number of the capacitor units included in the capacitor element is N, the capacitance C per unit for the center-to-center distance p between the first through conductor and the second through conductor is calculated from a hypothetical unit that satisfies all of the following conditions 1 to 4: ｕｎｉｔ When the correlation between the above is obtained, Condition 1: the total number of the virtual units included in the capacitor element is n; Condition 2: in a plan view in the thickness direction of the capacitor element, the area of ​​the virtual unit, the diameter of the first through hole, the area of ​​the first through conductor in the first through hole, the diameter of the second through hole, the area of ​​the second through conductor in the second through hole, and the center-to-center distance between the first through conductor and the second through conductor are equivalent between the virtual units; Condition 3: the area of ​​the first through conductor in the first through hole of the virtual unit is s ＴＨ１ , the area of ​​the second through conductor in the second through hole is s ＴＨ２ Condition 4: (s ＴＨ１ +s ＴＨ２ ) × n is (S ＴＨ１ +S ＴＨ２ ) × N, ｕｎｉｔ The center distance P when is at its maximum value ０ is different from the center distance P in the capacitor unit, and the center distance P ０ The total number n of the virtual units corresponding to the capacitance C per unit ｕｎｉｔ 3. The capacitor element according to claim 2, wherein an effective overall capacitance, which corresponds to the capacitance of the total area of ​​the capacitor units out of the capacitance of the entire capacitor element, is greater than a virtual overall capacitance obtained by multiplying the maximum value of 4. The center distance P in the capacitor unit is the center distance P when the substantial overall capacitance is at its maximum value. １ The capacitor element according to claim 3 , wherein 5. A capacitor element according to any one of claims 1 to 4, wherein the second through conductor is electrically connected to the current collecting foil on the inner wall surface of the second through hole.

6. The capacitor element according to claim 5, wherein the second through conductor is electrically connected to the current collecting foil around the entire periphery of the second through hole.

7. The capacitor element according to any one of claims 1 to 6, wherein the current collecting foil contains a metal.

8. The capacitor element according to any one of claims 1 to 7, wherein the thickness of the current collecting foil is 0.005 mm or more and 0.1 mm or less.

9. A capacitor element according to any one of claims 1 to 8, wherein the first electrode layer has a metal substrate and a porous portion provided on at least one main surface of the metal substrate, the dielectric layer is provided on the surface of the porous portion, and the second electrode layer is provided on the surface of the dielectric layer.

10. The capacitor element according to claim 9, wherein the second electrode layer includes a solid electrolyte layer provided on the surface of the dielectric layer.

11. A capacitor element as described in claim 3 or 4, wherein the capacitor unit includes a first unit and a second unit adjacent to the first unit, and when viewed in a plane in the thickness direction of the capacitor element, the center-to-center distance between the first through conductor of the first unit and the second through conductor of the first unit is equal to the center-to-center distance between the first through conductor of the first unit and the second through conductor of the second unit.

12. A capacitor element as described in claim 11, wherein the capacitor unit further includes a third unit adjacent to the first unit, and when viewed in a plane in the thickness direction of the capacitor element, the center-to-center distance between the second through conductor of the first unit and the second through conductor of the second unit is equal to the center-to-center distance between the second through conductor of the first unit and the second through conductor of the third unit.

13. A capacitor element according to claim 12, wherein, in a planar view of the capacitor element in the thickness direction, the second through conductor of the third unit is located on a straight line obtained by rotating a line segment connecting the center of the second through conductor of the first unit and the center of the second through conductor of the second unit at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the second through conductor of the first unit.

14. A capacitor element as described in claim 3, 4, 11, 12 or 13, wherein the capacitor unit includes a first unit and a second unit adjacent to the first unit, and when viewed in a plane in the thickness direction of the capacitor element, the center-to-center distance between the second through conductor of the first unit and the first through conductor of the first unit is equal to the center-to-center distance between the second through conductor of the first unit and the first through conductor of the second unit.

15. A capacitor element as described in claim 14, wherein the capacitor unit further includes a third unit adjacent to the first unit, and when viewed in a plane in the thickness direction of the capacitor element, the center-to-center distance between the first through conductor of the first unit and the first through conductor of the second unit is equal to the center-to-center distance between the first through conductor of the first unit and the first through conductor of the third unit.

16. A capacitor element according to claim 15, wherein, in a planar view of the capacitor element in the thickness direction, the first through conductor of the third unit is located on a straight line obtained by rotating a line segment connecting the center of the first through conductor of the first unit and the center of the first through conductor of the second unit at an angle of 60 degrees, 90 degrees, 120 degrees, or 180 degrees with respect to the center of the first through conductor of the first unit.

17. A capacitor element according to any one of claims 11 to 16, wherein the area of ​​the capacitor unit is expressed as 2P x P or 2P x √3 / 2 x P in a plan view in the thickness direction of the capacitor element.

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