Capacitor built-in board

Abstract

A substrate 1 with a built-in capacitor comprises: a capacitor element 100; and a wiring board 200 into which the capacitor element 100 is built. The capacitor element 100 includes a capacitor 10, and a sealing layer 20 provided so as to cover at least one main surface of the capacitor 10. The capacitor 10 includes: an anode plate 11 having a porous section 11B on at least one main surface of a core section 11A; a dielectric layer 13 provided on a surface of the porous section 11B; and a cathode layer 12 provided on a surface of the dielectric layer 13. At least one first capacitor through-hole 35A and at least one second capacitor through-hole 35B are provided so as to penetrate the capacitor element 100 without penetrating the wiring board 200 in the thickness direction of the anode plate 11. A capacitor-penetrating anode conductor 30A electrically connected to an end surface of the anode plate 11 is provided inside the first capacitor through hole 35A. A first substrate through hole 45A is provided on the inside of the first capacitor through hole 35A and a second substrate through hole 45B is provided on the inside of the second capacitor through hole 35B so as to penetrate the wiring board 200 and the capacitor element 100 in the thickness direction of the anode plate 11. A substrate-penetrating anode conductor 40A electrically connected to the anode plate 11 is provided on an inner wall surface of the first substrate through hole 45A. A substrate-penetrating cathode conductor 40B electrically connected to the cathode layer 12 is provided on an inner wall surface of the second substrate through hole 45B. The substrate-penetrating anode conductor 40A is positioned on the inside of the capacitor-penetrating anode conductor 30A.

Description

[Technical Field]

[0001] The present invention relates to a substrate with built-in capacitors. [Background technology]

[0002] Patent Document 1 discloses a module including a capacitor layer including at least one capacitor unit forming a capacitor, a connection terminal, and a through-hole conductor formed to penetrate the capacitor unit in the thickness direction of the capacitor layer. The through-hole conductor includes a first through-hole conductor formed on at least the inner wall surface of a first through-hole penetrating the capacitor unit in the thickness direction. The first through-hole conductor is electrically connected to the anode of the capacitor unit. The capacitor unit includes an anode plate made of metal. The first through-hole conductor is connected to an end face of the anode plate. The module further includes an anode connection layer provided between the first through-hole conductor and the end face of the anode plate. The first through-hole conductor is connected to the end face of the anode plate via the anode connection layer. When viewed cross-sectionally from a direction perpendicular to the thickness direction, the first through-hole conductor in a portion where the anode connection layer is present protrudes toward the inside of the first through-hole compared to the first through-hole conductor in a portion where the anode connection layer is not present. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-172255 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes, as one embodiment of a module, a capacitor-embedded substrate in which a capacitor element is embedded in a wiring substrate.

[0005] In order to manufacture such a capacitor-embedded substrate, Figures 14A and 14B of Patent Document 1 describe that through holes 263 and 265 are formed by drilling or laser processing in the areas where through-hole conductors 262 and 264 are to be formed, and then the inner surfaces of through holes 263 and 265 are metallized by electroless Cu plating or the like to form through-hole conductors 262 and 264.

[0006] In this case, for example, when forming through-hole conductor 262 so as to be connected to the end face of anode plate 231, anode plate 231 and conductive portion 220 are simultaneously exposed on the inner surface of through hole 263 for through-hole conductor 262. However, since anode plate 231 is generally made of a valve metal such as Al (aluminum), while conductive portion 220 is made of a metal such as Cu (copper), it is difficult to form through-hole conductor 262 using a general method such as plating on the surface of through hole 263 where these different metals are exposed.

[0007] The present invention has been made to solve the above problems, and aims to provide a capacitor-embedded substrate in which a capacitor through-hole anode conductor connected to the end face of an anode plate can be formed using a conventional method. [Means for solving the problem]

[0008] The capacitor-embedded substrate of the present invention includes a capacitor element and a wiring board incorporating the capacitor element. The capacitor element includes a capacitor portion and a sealing layer provided so as to cover at least one main surface of the capacitor portion. The capacitor portion includes an anode plate having a porous portion on at least one main surface of a core portion, a dielectric layer provided on the surface of the porous portion, and a cathode layer provided on the surface of the dielectric layer. At least one first capacitor through-hole and at least one second capacitor through-hole are provided so as to penetrate the capacitor element in the thickness direction of the anode plate without penetrating the wiring board. A capacitor through-hole anode conductor electrically connected to an end face of the anode plate is provided inside the first capacitor through-hole. A first substrate through-hole is provided inside the first capacitor through-hole, and a second substrate through-hole is provided inside the second capacitor through-hole, so as to penetrate the wiring board and the capacitor element in the thickness direction of the anode plate. A through-substrate anode conductor electrically connected to the anode plate is provided on an inner wall surface of the first through-substrate hole. A through-substrate cathode conductor electrically connected to the cathode layer is provided on an inner wall surface of the second through-substrate hole. The through-substrate anode conductor is located inside the capacitor through-substrate anode conductor. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a capacitor-embedded substrate in which a capacitor through-hole anode conductor connected to an end face of an anode plate can be formed using a common method. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the capacitor-embedded substrate shown in FIG. 1 taken along line AA. [Figure 3] 3 is a plan view of the capacitor-embedded substrate taken along line BB shown in FIG. [Figure 4]4A to 4G are cross-sectional views schematically showing an example of a method for producing a capacitor element having a capacitor-embedded anode conductor, among methods for producing a capacitor-embedded substrate within the scope of the present invention. [Figure 5] 5A to 5C are cross-sectional views schematically showing an example of a method for producing a capacitor-embedded substrate using a capacitor element having a capacitor-penetrating anode conductor. [Figure 6] 6A to 6D are cross-sectional views that schematically show an example of a method for producing a capacitor element that does not have a capacitor through-hole anode conductor, among methods for producing a capacitor-embedded substrate that is outside the scope of the present invention. [Figure 7] 7A to 7C are cross-sectional views schematically showing an example of a method for producing a capacitor-embedded substrate using a capacitor element that does not have a capacitor through-hole anode conductor. [Figure 8] FIG. 8 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a plan view of the capacitor-embedded substrate shown in FIG. 8 taken along line AA. [Figure 10] FIG. 10 is a plan view of the capacitor-embedded substrate shown in FIG. 8 taken along line BB. [Figure 11] FIG. 11 is a plan view schematically showing an example of a capacitor-embedded substrate according to a third embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fourth embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The capacitor-embedded substrate 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.

[0012] 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 due to similar configurations will not be mentioned one after the other for each embodiment.

[0013] In the following description, when there is no need to particularly distinguish between the embodiments, they will simply be referred to as "the capacitor-embedded substrate of the present invention."

[0014] 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 they are substantially equivalent, for example, including a difference of about a few percent. Furthermore, in this specification, "equivalent" is not an expression that means only complete equivalent, but is an expression that means that they are substantially equivalent, for example, including a difference of about a few percent.

[0015] 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.

[0016] [First embodiment] Fig. 1 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a first embodiment of the present invention. Fig. 2 is a plan view taken along line AA of the capacitor-embedded substrate shown in Fig. 1. Fig. 3 is a plan view taken along line BB of the capacitor-embedded substrate shown in Fig. 1.

[0017] The capacitor-embedded substrate 1 shown in FIG. 1 includes a capacitor element 100 and a wiring substrate 200 in which the capacitor element 100 is embedded.

[0018] Capacitor element 100 includes capacitor section 10 and sealing layer 20 provided to cover at least one main surface of capacitor section 10. In the example shown in Fig. 1 , sealing layer 20 includes first sealing layer 21 covering capacitor section 10 and second sealing layer 22 covering first sealing layer 21.

[0019] 1, 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.

[0020] 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 of the main surfaces of the core portion 11A.

[0021] Cathode layer 12 includes, for example, a solid electrolyte layer provided on the surface of dielectric layer 13. Cathode layer 12 preferably further includes a conductor layer provided on the surface of the solid electrolyte layer. When cathode layer 12 includes a solid electrolyte layer, capacitor section 10 constitutes a solid electrolytic capacitor.

[0022] The sealing layer 20 may be composed of only one layer, or may be composed of two or more layers. When the sealing layer 20 is composed of two or more layers, the materials constituting each layer may be the same or different.

[0023] 1, sealing layer 20 is preferably provided on both main surfaces of capacitor section 10 that face each other in the thickness direction. Capacitor section 10 is protected by sealing layer 20.

[0024] The capacitor-built-in substrate 1 is provided with at least one first capacitor through-hole 35A and at least one second capacitor through-hole 35B so as to penetrate the capacitor element 100 without penetrating the wiring board 200 in the thickness direction of the anode plate 11 (the vertical direction in FIG. 1). The first capacitor through-hole 35A and the second capacitor through-hole 35B are arranged apart from each other.

[0025] The planar shape of the first capacitor through-hole 35A (for example, the cross-sectional shape perpendicular to the thickness direction) is not particularly limited and may be, for example, a circular shape.Similarly, the planar shape of the second capacitor through-hole 35B is not particularly limited and may be, for example, a circular shape.

[0026] The first capacitor through-hole 35A is preferably present in the cathode layer 12 when viewed in plan in the thickness direction of the anode plate 11. Similarly, the second capacitor through-hole 35B is preferably present in the cathode layer 12 when viewed in plan in the thickness direction of the anode plate 11.

[0027] The number of first capacitor through holes 35A may be the same as, less than, or more than the number of second capacitor through holes 35B.

[0028] The diameter of the first capacitor through-hole 35A may be equal to the diameter of the second capacitor through-hole 35B, may be smaller than the diameter of the second capacitor through-hole 35B, or may be larger than the diameter of the second capacitor through-hole 35B.

[0029] 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.

[0030] The diameter of the first capacitor through-hole 35A may be constant or may vary in the thickness direction, and similarly, the diameter of the second capacitor through-hole 35B may be constant or may vary in the thickness direction.

[0031] When a plurality of first capacitor through holes 35A are provided, the diameters of the first capacitor through holes 35A may be the same, or some or all of the first capacitor through holes 35A may be different.

[0032] When a plurality of second capacitor through holes 35B are provided, the diameters of the second capacitor through holes 35B may be the same, or some or all of the second capacitor through holes 35B may be different.

[0033] A capacitor through-hole anode conductor 30A electrically connected to the end face of the anode plate 11 is provided inside the first capacitor through-hole 35A.

[0034] In other words, the capacitor through-hole anode conductor 30A is electrically connected to the anode plate 11 on the inner wall surface of the first capacitor through-hole 35A. Therefore, no insulating material such as the sealing layer 20 is filled between the capacitor through-hole anode conductor 30A and the end surface of the anode plate 11.

[0035] 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 capacitor through-hole anode conductor 30A. In this case, the porous portion 11B as well as the core portion 11A are electrically connected to the capacitor through-hole anode conductor 30A.

[0036] When viewed in the thickness direction of the anode plate 11, the capacitor through-hole anode conductor 30A is preferably electrically connected to the anode plate 11 along the entire periphery of the first capacitor through-hole 35A, as shown in FIG.

[0037] The capacitor through-hole anode conductor 30A may be electrically connected to the end surface of the anode plate 11 via an anode connection layer, or may be directly connected to the end surface of the anode plate 11.

[0038] When multiple first capacitor through holes 35A are provided, some of the first capacitor through holes 35A may not have a capacitor through anode conductor 30A provided inside, but it is preferable that all of the first capacitor through holes 35A have a capacitor through anode conductor 30A provided inside.

[0039] Furthermore, the capacitor-embedded substrate 1 has a first substrate through-hole 45A provided inside the first capacitor through-hole 35A so as to penetrate the wiring substrate 200 and the capacitor element 100 in the thickness direction of the anode plate 11, and a second substrate through-hole 45B provided inside the second capacitor through-hole 35B.

[0040] The planar shape of first substrate through-hole 45A is not particularly limited and may be, for example, a circular shape.Similarly, the planar shape of second substrate through-hole 45B is not particularly limited and may be, for example, a circular shape.

[0041] When a plurality of first capacitor through holes 35A are provided, some of the first capacitor through holes 35A may not have a first substrate through hole 45A inside them, but it is preferable that the first substrate through holes 45A be provided inside all of the first capacitor through holes 35A. Similarly, when a plurality of second capacitor through holes 35B are provided, some of the second capacitor through holes 35B may not have a second substrate through hole 45B inside them, but it is preferable that the second substrate through holes 45B be provided inside all of the second capacitor through holes 35B.

[0042] The diameter of the first substrate through-hole 45A is not particularly limited as long as it is smaller than the diameter of the first capacitor through-hole 35A. Similarly, the diameter of the second substrate through-hole 45B is not particularly limited as long as it is smaller than the diameter of the second capacitor through-hole 35B.

[0043] The diameter of first substrate through-hole 45A may be equal to the diameter of second substrate through-hole 45B, may be smaller than the diameter of second substrate through-hole 45B, or may be larger than the diameter of second substrate through-hole 45B.

[0044] The diameter of the first substrate through-hole 45A may be constant or may vary in the thickness direction. Similarly, the diameter of the second substrate through-hole 45B may be constant or may vary in the thickness direction.

[0045] When a plurality of first substrate through holes 45A are provided, the diameters of the first substrate through holes 45A may be the same, or some or all of the first substrate through holes 45A may be different.

[0046] When a plurality of second substrate through holes 45B are provided, the diameters of the second substrate through holes 45B may be the same, or some or all of the second substrate through holes 45B may be different.

[0047] A substrate through-hole 45A has an inner wall surface provided with a substrate through-hole anode conductor 40A electrically connected to anode plate 11. A substrate through-hole cathode conductor 40B electrically connected to cathode layer 12 has an inner wall surface provided with a substrate through-hole 45B.

[0048] As shown in FIGS. 1 and 2, the substrate through-hole anode conductor 40A is located inside the capacitor through-hole anode conductor 30A.

[0049] As will be described later, after forming the capacitor through-hole anode conductor 30A so as to be connected to the end face of the anode plate 11, the through-substrate anode conductor 40A is formed inside the capacitor through-hole anode conductor 30A. This prevents the metal constituting the anode plate 11 from being exposed on the inner surface of the first through-hole 45A for forming the through-substrate anode conductor 40A. Therefore, the through-substrate anode conductor 40A can be easily formed using a common technique such as plating.

[0050] Even if the through-substrate anode conductor 40A is formed at a position different from the capacitor through-substrate anode conductor 30A after the capacitor through-substrate anode conductor 30A is formed, the metal constituting the anode plate 11 is not exposed on the inner surface of the first substrate through hole 45A for forming the through-substrate anode conductor 40A. In this case, however, the area where the capacitor functions is reduced, the capacitance is reduced, and the capacitor performance is reduced. In contrast, by forming the through-substrate anode conductor 40A inside the capacitor through-substrate anode conductor 30A, the area where the capacitor does not function is reduced, thereby preventing a decrease in capacitor performance.

[0051] As shown in FIG. 2, when viewed in the thickness direction of the anode plate 11, the substrate through-hole anode conductor 40A is preferably provided around the entire periphery of the inner wall surface of the first substrate through-hole 45A.

[0052] As shown in FIG. 3, when viewed in the thickness direction of the anode plate 11, the substrate through-hole cathode conductor 40B is preferably provided around the entire periphery of the inner wall surface of the second substrate through-hole 45B.

[0053] 2 and 3, the diameter of the through-substrate anode conductor 40A is preferably equal to the diameter of the through-substrate cathode conductor 40B. The diameter of the through-substrate anode conductor 40A may be smaller or larger than the diameter of the through-substrate cathode conductor 40B.

[0054] In this specification, the diameter of a through conductor means the diameter when the planar shape is circular, and means the equivalent circle diameter when the planar shape is other than circular.

[0055] In particular, it is preferable that the area of ​​the through-substrate anode conductor 40A is equal to the area of ​​the through-substrate cathode conductor 40B when viewed in the thickness direction of the anode plate 11. The area of ​​the through-substrate anode conductor 40A may be smaller or larger than the area of ​​the through-substrate cathode conductor 40B.

[0056] The material constituting the through-substrate anode conductor 40A may be the same as or different from the material constituting the through-substrate cathode conductor 40B.

[0057] The material constituting the capacitor through-hole anode conductor 30A may be the same as or different from the material constituting the substrate through-hole anode conductor 40A.

[0058] 1, it is preferable that an insulating material such as a sealing layer 20 is filled between the substrate through-hole anode conductor 40A and the capacitor through-hole anode conductor 30A. In the example shown in Fig. 1, a second sealing layer 22 is filled between the substrate through-hole anode conductor 40A and the capacitor through-hole anode conductor 30A.

[0059] In addition, it is preferable that an insulating material such as a sealing layer 20 is filled between the through-substrate cathode conductor 40B and the end face of the anode plate 11. In the example shown in FIG. 1, a first sealing layer 21 is filled between the through-substrate cathode conductor 40B and the end face of the anode plate 11.

[0060] 1, the capacitor element 100 may further include an insulating mask layer 25 provided around the first capacitor through-hole 35A on at least one main surface of the anode plate 11. The insulating mask layer 25 provided around the first capacitor through-hole 35A is preferably provided between the capacitor through-hole anode conductor 30A and the cathode layer 12.

[0061] Capacitor element 100 may further include an insulating mask layer 25 provided around second capacitor through-hole 35B on at least one main surface of anode plate 11. Insulating mask layer 25 provided around second capacitor through-hole 35B is preferably provided between cathode layer 12 and an insulating material (first sealing layer 21 in FIG. 1 ) filled between through-substrate cathode conductor 40B and capacitor portion 10.

[0062] 1, the capacitor section 10 may further include an insulating mask layer 25 provided on at least one main surface of the anode plate 11 so as to surround the periphery of the cathode layer 12. 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, or may be provided so as to surround the entire periphery of the cathode layer 12.

[0063] 1, a first resin filling portion 48A filled with a resin material may be provided inside the substrate-penetrating anode conductor 40A. In this case, the first resin filling portion 48A is provided in the space surrounded by the substrate-penetrating anode conductor 40A inside the first substrate-penetrating hole 45A. When the space inside the first substrate-penetrating hole 45A is eliminated by providing the first resin filling portion 48A, delamination of the substrate-penetrating anode conductor 40A is suppressed. The first resin filling portion 48A may be a conductor or an insulator.

[0064] Furthermore, a second resin filling portion 48B filled with a resin material may be provided inside the substrate through-hole cathode conductor 40B. In this case, the second resin filling portion 48B is provided in the space surrounded by the substrate through-hole cathode conductor 40B in the second substrate through-hole 45B. When the space in the second substrate through-hole 45B is eliminated by providing the second resin filling portion 48B, the occurrence of delamination of the substrate through-hole cathode conductor 40B is suppressed. The second resin filling portion 48B may be a conductor or an insulator.

[0065] In the example shown in FIG. 1, first wiring layers 51A and 51B are provided between first sealing layer 21 and second sealing layer 22, and second wiring layers 52A and 52B are provided on the surface of second sealing layer 22.

[0066] 1, the first wiring layers 51A and 51B are provided on both the upper and lower sides of the capacitor element 100, but may be provided on only one of them. Similarly, the second wiring layers 52A and 52B are provided on both the upper and lower sides of the capacitor element 100, but may be provided on only one of them.

[0067] The wiring substrate 200 includes, for example, a sealing and insulating layer 50. In the example shown in FIG.

[0068] The sealing insulating layer 50 may be composed of only one layer, or may be composed of two or more layers. When the sealing insulating layer 50 is composed of two or more layers, the materials constituting each layer may be the same or different. The sealing insulating layer 50 may be composed of the same material as the sealing layer 20, or may be composed of a different material from the sealing layer 20.

[0069] As shown in Fig. 1, the sealing insulating layer 50 is preferably provided on both main surfaces of the capacitor element 100 that face each other in the thickness direction. As shown in Fig. 1, in addition to both main surfaces of the capacitor element 100, it is also preferable that at least a portion of the side surface of the capacitor element 100 is covered with the sealing insulating layer 50.

[0070] In the example shown in FIG. 1, third wiring layers 53A and 53B are provided on the surface of the sealing insulating layer 50.

[0071] In FIG. 1, the third wiring layers 53A and 53B are provided on both the upper and lower sides of the capacitor element 100, but they may be provided on only one side.

[0072] The first wiring layer 51A is electrically connected to the capacitor through anode conductor 30A. In the example shown in Fig. 1, the first wiring layer 51A is connected to an end of the capacitor through anode conductor 30A.

[0073] The second wiring layer 52A is electrically connected to the first wiring layer 51 A. The second wiring layer 52A is connected to the first wiring layer 51 A through an anode via conductor 55A that penetrates the second sealing layer 22, for example.

[0074] Furthermore, the second wiring layer 52A is electrically connected to the through-substrate anode conductor 40A. In the example shown in Fig. 1, the through-substrate anode conductor 40A is connected to the end of the second wiring layer 52A.

[0075] The third wiring layer 53A is electrically connected to the through-substrate anode conductor 40 A. In the example shown in Fig. 1, the third wiring layer 53A is connected to the end of the through-substrate anode conductor 40A.

[0076] As described above, the third wiring layer 53A is electrically connected to the anode plate 11 via the through-substrate anode conductor 40A, the second wiring layer 52A, the anode via conductor 55A, the first wiring layer 51A, and the capacitor through-anode conductor 30A.

[0077] The first wiring layer 51B is electrically connected to the cathode layer 12. The first wiring layer 51B is connected to the cathode layer 12 through a cathode via conductor 55B that penetrates the first sealing layer 21, for example.

[0078] Furthermore, the first wiring layer 51B is electrically connected to the through-substrate cathode conductor 40B. In the example shown in Fig. 1, the through-substrate cathode conductor 40B is connected to an end of the first wiring layer 51B.

[0079] The second wiring layer 52B is electrically connected to the through-substrate cathode conductor 40B. In the example shown in Fig. 1, the through-substrate cathode conductor 40B is connected to an end of the second wiring layer 52B. Although not shown in Fig. 1, the second wiring layer 52B may be connected to the first wiring layer 51B through a cathode via conductor that penetrates the second sealing layer 22.

[0080] The third wiring layer 53B is electrically connected to the through-substrate cathode conductor 40B. In the example shown in Fig. 1, the third wiring layer 53B is connected to an end of the through-substrate cathode conductor 40B.

[0081] As described above, the third wiring layer 53B is electrically connected to the cathode layer 12 via the through-substrate cathode conductor 40B, the second wiring layer 52B, the first wiring layer 51B, and the cathode via conductor 55B.

[0082] The capacitor-embedded substrate 1 shown in FIG. 1 is produced, for example, by the following method.

[0083] 4A to 4G are cross-sectional views schematically showing an example of a method for producing a capacitor element having a capacitor-embedded anode conductor, among methods for producing a capacitor-embedded substrate within the scope of the present invention.

[0084] In FIG. 4A, a capacitor assembly 10 is provided.

[0085] For example, an anode plate 11 having a porous portion 11B on at least one main surface of a core portion 11A is subjected to an anodization treatment to form a dielectric layer 13 on the surface of the porous portion 11B.

[0086] Alternatively, a chemically formed foil may be prepared as the anode plate 11 having the dielectric layer 13 provided on the surface of the porous portion 11B.

[0087] Next, an insulating mask layer 25 is formed in an area including the portion where the first capacitor through-hole 35A (see FIG. 4D) and the second capacitor through-hole 35B (see FIG. 4B) are to be formed. For example, an insulating resin is applied to the surface of the dielectric layer 13 by a method such as screen printing or dispenser application, thereby forming the insulating mask layer 25 in a predetermined area.

[0088] Next, the cathode layer 12 is formed on the surface of the dielectric layer 13 in an area where the insulating mask layer 25 is not provided. For example, the cathode layer 12 is formed by sequentially forming a solid electrolyte layer and a conductor layer on the surface of the dielectric layer 13. In this manner, the capacitor section 10 is obtained.

[0089] In FIG. 4B, a second capacitor through-hole 35B is formed so as to penetrate through the capacitor section 10. In FIG.

[0090] For example, by performing processing such as drilling or laser processing, a second capacitor through-hole 35B is formed that penetrates the insulating mask layer 25 and the anode plate 11 in the thickness direction.

[0091] 4C, both main surfaces of capacitor section 10 are covered with first sealing layer 21. As shown in FIG. 4C, first sealing layer 21 is preferably filled into second capacitor through-hole 35B.

[0092] In FIG. 4D, a first capacitor through-hole 35A is formed so as to penetrate through the capacitor section 10 and the first sealing layer 21. In FIG.

[0093] For example, first capacitor through-holes 35A are formed by drilling, laser processing, or other processing, penetrating first sealing layer 21, insulating mask layer 25, and anode plate 11 in the thickness direction.

[0094] As shown in FIG. 4D, no metal other than anode plate 11 is exposed on the inner surface of first capacitor through-hole 35A.

[0095] In FIG. 4E, a capacitor through-hole anode conductor 30A is formed on the inner wall surface of the first capacitor through-hole 35A.

[0096] For example, the capacitor through-hole anode conductor 30A is formed by metallizing the inner wall surface of the first capacitor through-hole 35A with a low-resistance metal such as copper, gold, or silver. When forming the capacitor through-hole anode conductor 30A, for example, metallizing the inner wall surface of the first capacitor through-hole 35A with electroless copper plating, electrolytic copper plating, or the like facilitates processing. Note that, in addition to the method of metallizing the inner wall surface of the first capacitor through-hole 35A, the capacitor through-hole anode conductor 30A may also be formed by filling the first capacitor through-hole 35A with a metal, a composite material of metal and resin, or the like.

[0097] As a result of the above, the capacitor through-hole anode conductor 30A connected to the end surface of the anode plate 11 is formed.

[0098] In FIG. 4F, cathode via conductor 55B, first wiring layer 51A, and first wiring layer 51B are formed in predetermined regions.

[0099] The cathode via conductor 55B is formed, for example, by forming a through hole that penetrates the first sealing layer 21 in the thickness direction, and then plating the inner wall surface of the through hole with a low-resistance metal such as copper, gold, or silver, or by filling it with a conductive paste and then performing a heat treatment.

[0100] The first wiring layer 51A and the first wiring layer 51B are formed by, for example, performing a plating process on the surface of the first sealing layer 21.

[0101] 4G, first sealing layer 21, first wiring layer 51A, and first wiring layer 51B are covered with second sealing layer 22 to form sealing layer 20. As shown in FIG. 4G, first capacitor through-hole 35A is preferably filled with second sealing layer 22. Thereafter, anode via conductors 55A, second wiring layers 52A, and second wiring layers 52B are formed in predetermined regions.

[0102] The anode via conductor 55A is formed, for example, by forming a through hole that penetrates the second sealing layer 22 in the thickness direction, and then plating the inner wall surface of the through hole with a low-resistance metal such as copper, gold, or silver, or by filling it with a conductive paste and then performing a heat treatment.

[0103] The second wiring layer 52A and the second wiring layer 52B are formed by, for example, performing a plating process on the surface of the second sealing layer 22.

[0104] In this way, the capacitor element 100 is fabricated.

[0105] 5A to 5C are cross-sectional views schematically showing an example of a method for producing a capacitor-embedded substrate using a capacitor element having a capacitor-penetrating anode conductor.

[0106] In FIG. 5A, capacitor element 100 is covered with an encapsulating insulating layer 50. In FIG.

[0107] For example, the sealing insulating layer 50 is formed by covering the capacitor element 100 with a sealing material having a metal foil such as copper foil on the surface.

[0108] In FIG. 5B, a first substrate through-hole 45A and a second substrate through-hole 45B are formed so as to penetrate through the sealing insulating layer 50, the sealing layer 20 and the capacitor section 10. In FIG.

[0109] For example, first substrate through-hole 45A is formed by performing processing such as drilling or laser processing on the inside of first capacitor through-hole 35A. At this time, by making the diameter of first substrate through-hole 45A smaller than the diameter of first capacitor through-hole 35A, an insulating material such as second sealing layer 22 is present between the inner wall surface of first capacitor through-hole 35A and the inner wall surface of first substrate through-hole 45A in the planar direction.

[0110] Similarly, second substrate through-hole 45B is formed inside second capacitor through-hole 35B by drilling, laser processing, or the like. At this time, by making the diameter of second substrate through-hole 45B smaller than the diameter of second capacitor through-hole 35B, an insulating material such as first sealing layer 21 is present between the inner wall surface of second capacitor through-hole 35B and the inner wall surface of second substrate through-hole 45B in the surface direction.

[0111] As shown in FIG. 5B, the anode plate 11 is not exposed on the inner surface of the first substrate through-hole 45A and the inner surface of the second substrate through-hole 45B, and only the metal constituting the wiring layers such as the second wiring layer 52A is exposed.

[0112] In FIG. 5C, a through-substrate anode conductor 40A is formed on the inner wall surface of a first substrate through-hole 45A, and a through-substrate cathode conductor 40B is formed on the inner wall surface of a second substrate through-hole 45B.

[0113] For example, the through-substrate anode conductor 40A is formed by metallizing the inner wall surface of the first substrate through-hole 45A with a low-resistance metal such as copper, gold, or silver. When forming the through-substrate anode conductor 40A, for example, metallizing the inner wall surface of the first substrate through-hole 45A by electroless copper plating, electrolytic copper plating, or the like facilitates processing. The through-substrate anode conductor 40A may be formed by filling the first substrate through-hole 45A with a metal, a composite material of metal and resin, or the like, in addition to metallizing the inner wall surface of the first substrate through-hole 45A. The same applies to the method for forming the through-substrate cathode conductor 40B. The through-substrate anode conductor 40A and the through-substrate cathode conductor 40B may be formed simultaneously or separately.

[0114] As shown in FIG. 5C, it is preferable to form a first resin filling portion 48A and a second resin filling portion 48B, and then form a third wiring layer 53A and a third wiring layer 53B.

[0115] In this manner, a capacitor-embedded substrate 1 in which the capacitor element 100 is embedded in the wiring substrate 200 is fabricated.

[0116] On the other hand, FIGS. 6A to 6D are cross-sectional views that schematically show an example of a method for producing a capacitor element that does not have a capacitor through-hole anode conductor, among methods for producing a capacitor-embedded substrate that is outside the scope of the present invention.

[0117] In FIG. 6A, similarly to FIG. 4A, the capacitor section 10 is prepared.

[0118] In FIG. 6B, a second capacitor through-hole 35B is formed so as to penetrate through the capacitor section 10, similar to FIG. 4B.

[0119] 6C, similar to FIG. 4C, both main surfaces of capacitor section 10 are covered with first sealing layer 21. As shown in FIG. 6C, second capacitor through-hole 35B is preferably filled with first sealing layer 21. In the example shown in FIG. 6C, sealing layer 20 is formed by first sealing layer 21.

[0120] In FIG. 6D, similarly to FIG. 4F, cathode via conductor 55B, first wiring layer 51A and first wiring layer 51B are formed in predetermined regions.

[0121] In this way, the capacitor element 100a is formed.

[0122] 7A to 7C are cross-sectional views schematically showing an example of a method for producing a capacitor-embedded substrate using a capacitor element that does not have a capacitor through-hole anode conductor.

[0123] In FIG. 7A, capacitor element 100a is covered with sealing insulating layer 50, similar to FIG. 5A.

[0124] 7B, a first substrate through-hole 45A and a second substrate through-hole 45B are formed so as to penetrate through the sealing insulating layer 50, the sealing layer 20, and the capacitor section 10, similarly to FIG. 5B.

[0125] Unlike FIG. 5B, in FIG. 7B, not only the metals constituting the wiring layers such as the first wiring layer 51A but also the anode plate 11 are exposed on the inner surface of the first substrate through-hole 45A.

[0126] In FIG. 7C, similar to FIG. 5C, a through-substrate anode conductor 40A is formed on the inner wall surface of a first substrate through-hole 45A, and a through-substrate cathode conductor 40B is formed on the inner wall surface of a second substrate through-hole 45B.

[0127] As a result of the above, a capacitor-embedded substrate 1a in which the capacitor element 100a is embedded in the wiring substrate 200 is fabricated.

[0128] As described above, in the method for manufacturing the capacitor-embedded substrate 1a, a different type of metal is exposed on the inner surface of the first substrate through-hole 45A, making it difficult to form the substrate through-hole anode conductor 40A using a general method such as plating.

[0129] In contrast, in the method for manufacturing the capacitor-embedded substrate 1, no different metal is exposed on the inner surface of the first substrate through-hole 45A, so the substrate through-hole anode conductor 40A can be easily formed using a common technique such as plating.

[0130] [Second embodiment] In the capacitor-embedded substrate according to the second embodiment of the present invention, a capacitor through-hole cathode conductor is provided inside the second capacitor through-hole.

[0131] Fig. 8 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a second embodiment of the present invention. Fig. 9 is a plan view taken along line AA of the capacitor-embedded substrate shown in Fig. 8. Fig. 10 is a plan view taken along line BB of the capacitor-embedded substrate shown in Fig. 8.

[0132] In the capacitor-embedded substrate 2 shown in FIG. 8, a capacitor through-cathode conductor 30B that is not electrically connected to the anode plate 11 but is electrically connected to the cathode layer 12 is provided inside the second capacitor through-hole 35B.

[0133] As shown in FIGS. 8 and 10, the substrate through-cathode conductor 40B is located inside the capacitor through-cathode conductor 30B.

[0134] The capacitor-built-in substrate 2 shown in FIG. 8 has the same configuration as the capacitor-built-in substrate 1 shown in FIG. 1, except for the capacitor through cathode conductor 30B.

[0135] In addition to providing the capacitor through-hole anode conductor 30A inside the first capacitor through-hole 35A, the capacitor through-hole cathode conductor 30B inside the second capacitor through-hole 35B further improves the adhesive strength between the layers constituting the capacitor element 100. As a result, problems such as peeling between layers can be suppressed.

[0136] When multiple second capacitor through holes 35B are provided, some of the second capacitor through holes 35B may not have a capacitor through cathode conductor 30B provided inside, but it is preferable that all of the second capacitor through holes 35B have a capacitor through cathode conductor 30B provided inside.

[0137] 8, it is preferable that an insulating material such as a sealing layer 20 is filled between the capacitor through-type cathode conductor 30B and the end face of the anode plate 11. In the example shown in FIG. 8, a first sealing layer 21 is filled between the capacitor through-type cathode conductor 30B and the end face of the anode plate 11.

[0138] Furthermore, it is preferable that an insulating material such as a sealing layer 20 is filled between the substrate through-cathode conductor 40B and the capacitor through-cathode conductor 30B. For example, the same material as the first sealing layer 21 or the same material as the second sealing layer 22 may be filled between the substrate through-cathode conductor 40B and the capacitor through-cathode conductor 30B.

[0139] As shown in FIG. 10, when viewed in the thickness direction of the anode plate 11, the capacitor through-cathode conductor 30B is preferably provided along the entire periphery of the second capacitor through-hole 35B.

[0140] 9 and 10, the diameter of the capacitor through-hole anode conductor 30A is preferably equal to the diameter of the capacitor through-hole cathode conductor 30B. The diameter of the capacitor through-hole anode conductor 30A may be smaller or larger than the diameter of the capacitor through-hole cathode conductor 30B.

[0141] In particular, it is preferable that the area of ​​the capacitor through-hole anode conductor 30A is equal to the area of ​​the capacitor through-hole cathode conductor 30B when viewed in the thickness direction of the anode plate 11. The area of ​​the capacitor through-hole anode conductor 30A may be smaller or larger than the area of ​​the capacitor through-hole cathode conductor 30B.

[0142] The material constituting the capacitor through-hole anode conductor 30A may be the same as or different from the material constituting the capacitor through-hole cathode conductor 30B.

[0143] The material constituting the capacitor through-cathode conductor 30B may be the same as or different from the material constituting the substrate through-cathode conductor 40B.

[0144] As shown in Fig. 8, the capacitor through-hole cathode conductor 30B is preferably electrically connected to the first wiring layer 51B. In the example shown in Fig. 8, the first wiring layer 51B is connected to an end of the capacitor through-hole cathode conductor 30B.

[0145] [Third embodiment] In the capacitor-embedded substrate according to the third embodiment of the present invention, when viewed from above in the thickness direction of the anode plate, the center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to the center-to-center distance between the first through-substrate anode conductor and the second through-substrate cathode conductor, or the center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to the center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor.

[0146] In the third embodiment of the present invention, the center-to-center distance between the through-substrate anode conductor and the through-substrate cathode conductor is made uniform, thereby reducing the impedance difference between the current paths and dispersing heat generated by the capacitor element, thereby increasing the current capacity.

[0147] In this specification, the center of the through-substrate anode conductor or the center of the through-substrate cathode conductor refers to the center of the smallest circle that contains the through-substrate anode conductor or the through-substrate cathode conductor in a plan view from the thickness direction of the anode plate. Therefore, the center-to-center distance between the through-substrate anode conductor and the through-substrate cathode conductor refers to the length of the line segment connecting the center of the through-substrate anode conductor and the center of the through-substrate cathode conductor, which is determined by the above method. The same applies to the center-to-center distance between the through-substrate anode conductor and the through-substrate anode conductor, and the center-to-center distance between the through-substrate cathode conductor and the through-substrate cathode conductor.

[0148] In the third embodiment of the present invention, a capacitor through cathode conductor may not be provided as in the first embodiment, or a capacitor through cathode conductor may be provided as in the second embodiment.

[0149] 11 is a plan view schematically showing an example of a capacitor-embedded substrate according to a third embodiment of the present invention, taken at the same position as in FIGS.

[0150] In the capacitor-embedded substrate 3 shown in Fig. 11, the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are arranged in a hexagonal pattern as a whole. In the hexagonal pattern, the through-substrate anode conductors 40A or the through-substrate cathode conductors 40B 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 through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are arranged alternately from left to right. Note that when the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are arranged in a hexagonal pattern as a whole, the arrangement of the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B is not particularly limited, and for example, the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B may be arranged alternately two by two from left to right.

[0151] As shown in FIG. 11, in a plan view from the thickness direction of the anode plate 11, it is preferable that the center-to-center distance between the first through-substrate anode conductor 40A1 and the first through-substrate cathode conductor 40B1 (the length indicated by α in FIG. 11) is equal to the center-to-center distance between the first through-substrate anode conductor 40A1 and the second through-substrate cathode conductor 40B2 (the length indicated by β in FIG. 11).

[0152] In addition, when viewed in a plan view from the thickness direction of the anode plate 11, it is preferable that the center-to-center distance between the first through-substrate anode conductor 40A1 and the first through-substrate cathode conductor 40B1 (the length indicated by α in FIG. 11) is equal to the center-to-center distance between the second through-substrate anode conductor 40A2 and the first through-substrate cathode conductor 40B1 (the length indicated by γ in FIG. 11).

[0153] Unlike the arrangement shown in FIG. 11 , the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B may be arranged in a square as a whole. In the square arrangement, the through-substrate anode conductors 40A or the through-substrate cathode conductors 40B are arranged at each vertex of a square. For example, the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are alternately arranged from top to bottom, and the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are alternately arranged from left to right. Note that when the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B are arranged in a square as a whole, the arrangement of the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B is not particularly limited. For example, the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B may be alternately arranged in pairs from top to bottom, and the through-substrate anode conductors 40A and the through-substrate cathode conductors 40B may be alternately arranged in pairs from left to right.

[0154] [Fourth embodiment] In the capacitor-embedded substrate according to the fourth embodiment of the present invention, the thickness of the wiring substrate is at least twice the thickness of the capacitor element.

[0155] In the fourth embodiment of the present invention, even if the capacitor element is thin, the thickness of the capacitor-embedded substrate can be increased easily and at low cost by increasing the thickness of the wiring board, thereby increasing the rigidity of the capacitor-embedded substrate.

[0156] FIG. 12 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fourth embodiment of the present invention.

[0157] In the capacitor-embedded substrate 4 shown in FIG. 12, when the thickness of the capacitor element 100 is T1 and the thickness of the wiring board 200 is T2, the thickness T2 of the wiring board 200 is at least twice the thickness T1 of the capacitor element 100.

[0158] The thickness T2 of the wiring substrate 200 is preferably 2.5 times or more, and more preferably 3 times or more, the thickness T1 of the capacitor element 100. On the other hand, the thickness T2 of the wiring substrate 200 is, for example, 5 times or less the thickness T1 of the capacitor element 100.

[0159] The thickness T2 of the wiring substrate 200 is not particularly limited, but is, for example, 0.6 mm or more and 2.0 mm or less.

[0160] In the capacitor-embedded substrate 4 shown in Figure 12, when the thickness of the sealing insulation layer 50 is T3, the thickness T3 of the sealing insulation layer 50 provided on one side of the capacitor element 100 may be the same as or different from the thickness T3 of the sealing insulation layer 50 provided on the other side of the capacitor element 100.

[0161] The other configurations are the same as those of the first to third embodiments.

[0162] [Fifth embodiment] In the capacitor-embedded substrate according to the fifth embodiment of the present invention, the sealing insulating layer that constitutes the wiring board contains glass cloth, which increases the rigidity of the capacitor-embedded substrate.

[0163] FIG. 13 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fifth embodiment of the present invention.

[0164] 13, the sealing insulating layer 50 constituting the wiring board 200 includes a glass cloth 60. The glass cloth 60 is made by weaving glass yarns into, for example, a lattice pattern.

[0165] The glass cloth 60 may be included in the entire sealing insulation layer 50, or may be included unevenly in a part of the sealing insulation layer 50. In the example shown in Fig. 13, multiple layers of glass cloth 60 are laminated at intervals in the thickness direction. The glass cloth 60 in each layer is arranged along the surface direction.

[0166] The sealing insulating layer 50 including the glass cloth 60 is formed using, for example, a prepreg in which glass cloth is pre-impregnated with an insulating resin.

[0167] The other configurations are the same as those of the first to fourth embodiments.

[0168] The detailed configuration of capacitor element 100 will be described below.

[0169] One or more capacitor sections 10 may be disposed inside sealing layer 20. When more than one capacitor section 10 is disposed inside sealing layer 20, adjacent capacitor sections 10 are preferably separated from each other by a through groove that penetrates capacitor section 10 in the thickness direction (for example, the vertical direction in FIG. 1 ). In this case, the through groove is preferably filled with an insulating material such as sealing layer 20.

[0170] When adjacent capacitor sections 10 are separated by a through groove, the adjacent capacitor sections 10 only need to be physically separated by the through groove. Therefore, adjacent capacitor sections 10 may be electrically separated or electrically connected. The width of the through groove, i.e., the distance between adjacent capacitor sections 10, may be constant in the thickness direction or may decrease in the thickness direction.

[0171] When multiple capacitor sections 10 are arranged inside sealing layer 20, the multiple capacitor sections 10 may be arranged side by side in a plane direction perpendicular to the thickness direction, may be arranged so as to be stacked in the thickness direction, or may be arranged in a combination of both. The multiple capacitor sections 10 may be arranged regularly or irregularly. The size, shape, etc. of the capacitor sections 10 may be the same, or some or all of them may be different. It is preferable that the configuration of each capacitor section 10 is the same, but capacitor sections 10 with different configurations may be included.

[0172] Examples of the planar shape of capacitor section 10 when viewed in the thickness direction include a rectangle (square or oblong), a quadrangle other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, an ellipse, a combination of these, etc. Furthermore, the planar shape of capacitor section 10 may be an L-shape, a C-shape, a stepped shape, etc.

[0173] 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, as well as alloys containing at least one of these metals. Among these, aluminum or an aluminum alloy is preferred.

[0174] 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".

[0175] The anode plate 11 only needs to 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, 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.

[0176] 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 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.

[0177] 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 means the median diameter D50 measured by a mercury porosimeter. The pore diameter of the porous portion 11B can be controlled, for example, by adjusting various etching conditions.

[0178] 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 an aluminum foil is used as the anode plate 11, the dielectric layer 13 made of an oxide film can be formed by anodizing the surface of the aluminum foil in an aqueous solution containing ammonium adipate or the like (also called chemical conversion treatment).

[0179] 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.

[0180] When the cathode layer 12 includes a solid electrolyte layer, 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.

[0181] 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.

[0182] 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 of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer 13 and drying it.

[0183] 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.

[0184] When the cathode layer 12 includes a conductor layer, the conductor layer includes at least one layer selected from a conductive resin layer and a metal layer. The conductor layer may be a conductive resin layer alone or a metal layer alone. The conductor layer preferably covers the entire surface of the solid electrolyte layer.

[0185] The conductive resin layer may be, for example, a conductive adhesive layer containing at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler.

[0186] Examples of the metal layer include a metal plating film and a metal foil. 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 ratio.

[0187] The conductive layer includes, for example, a carbon layer provided on the surface of the solid electrolyte layer and a copper layer provided on the surface of the carbon layer.

[0188] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer and the copper layer. The carbon layer can be formed in a predetermined area by applying a carbon paste to the surface of the solid electrolyte layer by sponge transfer, screen printing, dispenser application, inkjet printing, or other methods. The thickness of the carbon layer is preferably 2 μm or more and 20 μm or less.

[0189] The copper layer can be formed in a predetermined area by applying a copper paste to the surface of the carbon layer by sponge transfer, screen printing, spray coating, dispenser coating, inkjet printing, etc. The thickness of the copper layer is preferably 2 μm or more and 20 μm or less.

[0190] The sealing layer 20 is made of an insulating material. In this case, the sealing layer 20 preferably contains an insulating resin.

[0191] Examples of the insulating resin contained in the sealing layer 20 include epoxy resin and phenol resin.

[0192] Preferably, the sealing layer 20 further contains a filler such as an inorganic filler.

[0193] Examples of the inorganic filler contained in the sealing layer 20 include silica particles and alumina particles.

[0194] Between the capacitor section 10 and the sealing layer 20, for example, a stress relaxation layer, a moisture-proof film, or other layer may be provided.

[0195] The insulating mask layer 25 is made of an insulating material, and in this case, the insulating mask layer 25 preferably contains an insulating resin.

[0196] Examples of insulating resins contained in 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.

[0197] Insulating mask layer 25 may be made of the same resin as sealing layer 20. Unlike sealing layer 20, if insulating mask layer 25 contains an inorganic filler, it may adversely affect the effective capacitance portion of capacitor section 10. Therefore, insulating mask layer 25 is preferably made of a resin alone.

[0198] 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.

[0199] The insulating mask layer 25 may be formed on the porous portion 11B either before or after the dielectric layer 13 is formed.

[0200] The constituent materials of the first wiring layer 51A and the first wiring layer 51B are preferably the same at least in terms of type, but may be different from each other.

[0201] The constituent materials of the second wiring layer 52A and the second wiring layer 52B are preferably the same as each other at least in terms of type, but may be different from each other. The constituent materials of the second wiring layer 52A and the second wiring layer 52B are preferably the same as the constituent materials of the first wiring layer 51A and the first wiring layer 51B.

[0202] The constituent materials of the third wiring layer 53A and the third wiring layer 53B are preferably the same as each other at least in terms of type, but may be different from each other. The constituent materials of the third wiring layer 53A and the third wiring layer 53B are preferably the same as the constituent materials of the first wiring layer 51A, the first wiring layer 51B, the second wiring layer 52A, and the second wiring layer 52B.

[0203] When the capacitor through-hole anode conductor 30A is electrically connected to the end surface of the anode plate 11 via the anode connection layer, the anode connection layer functions as a barrier layer for the anode plate 11, more specifically, as a barrier layer for the core portion 11A and the porous portion 11B. When the anode connection layer functions as a barrier layer for the anode plate 11, dissolution of the anode plate 11 that occurs during chemical treatment for forming wiring layers such as the first wiring layer 51A is suppressed, and therefore penetration of the chemical solution into the capacitor portion 10 is suppressed, which tends to improve reliability.

[0204] 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.

[0205] The capacitor through-hole anode conductor 30A may be directly connected to the end surface of the anode plate 11.

[0206] The capacitor-embedded substrate 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 or wiring substrate, the manufacturing conditions of the capacitor-embedded substrate, etc.

[0207] Furthermore, the technology of the indirect through conductor using the substrate through conductor in the capacitor-embedded substrate of the present invention is not limited to the electrolytic capacitors described above, but can also be applied to other capacitor elements. For example, the effects of the present invention can be provided even in a multilayer ceramic capacitor having a first electrode and a second electrode, in which the first electrode and the second electrode are embedded inside the substrate so as to face each other in the thickness direction of the substrate.

[0208] The capacitor-embedded substrate 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-embedded substrate of the present invention and an electronic component electrically connected to the capacitor-embedded substrate (for example, an external electrode layer).

[0209] In a composite electronic component, the electronic component electrically connected to the capacitor-embedded substrate may be a passive element or an active element. Both the passive element and the active element may be electrically connected to the capacitor-embedded substrate, or either the passive element or the active element may be electrically connected to the capacitor-embedded substrate. Also, a composite of a passive element and an active element may be electrically connected to the capacitor-embedded substrate.

[0210] 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).

[0211] The capacitor-embedded substrate of the present invention has a sheet-like shape as a whole. Therefore, in a composite electronic component, the capacitor-embedded substrate can be treated like a mounting substrate, and electronic components can be mounted on the capacitor-embedded substrate. Furthermore, by making the electronic components mounted on the capacitor-embedded substrate sheet-like, it is also possible to connect the capacitor-embedded substrate and the electronic components in the thickness direction via through 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.

[0212] For example, a switching regulator can be formed by electrically connecting a capacitor element between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied.

[0213] The present specification discloses the following:

[0214] <1> a capacitor element; a wiring board incorporating the capacitor element, the capacitor element includes a capacitor portion and a sealing layer provided so as to cover at least one main surface of the capacitor portion; the capacitor section includes 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; at least one first capacitor through-hole and at least one second capacitor through-hole are provided so as to penetrate the capacitor element without penetrating the wiring substrate in the thickness direction of the anode plate; a capacitor through-hole anode conductor is provided inside the first capacitor through-hole and is electrically connected to an end surface of the anode plate; a first substrate through-hole is provided inside the first capacitor through-hole, and a second substrate through-hole is provided inside the second capacitor through-hole, so as to penetrate through the wiring substrate and the capacitor element in a thickness direction of the anode plate; a substrate-penetrating anode conductor electrically connected to the anode plate is provided on an inner wall surface of the first substrate-penetrating hole; a substrate through-hole cathode conductor electrically connected to the cathode layer is provided on an inner wall surface of the second substrate through-hole; the substrate through-hole anode conductor is located inside the capacitor through-hole anode conductor; Board with built-in capacitor.

[0215] <2> a capacitor through-cathode conductor is provided inside the second capacitor through-hole, the capacitor through-cathode conductor being electrically connected to the cathode layer but not electrically connected to the anode plate; the substrate through-cathode conductor is located inside the capacitor through-cathode conductor; <1> The capacitor-embedded substrate according to claim 1.

[0216] <3> the through-substrate anode conductor includes a first through-substrate anode conductor; the through-substrate cathode conductors include a first through-substrate cathode conductor and a second through-substrate cathode conductor; In a plan view from the thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the first through-substrate anode conductor and the second through-substrate cathode conductor. <1> or <2> The capacitor-embedded substrate according to claim 1.

[0217] <4> the through-substrate anode conductor further includes a second through-substrate anode conductor; In a plan view from the thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor. <3> The capacitor-embedded substrate according to claim 1.

[0218] <5> the through-substrate anode conductors include a first through-substrate anode conductor and a second through-substrate anode conductor; the through-substrate cathode conductor includes a first through-substrate cathode conductor; In a plan view from the thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor. <1> ~ <4> 10. The capacitor-embedded substrate according to claim 9, wherein the capacitor-embedded substrate is a capacitor-embedded substrate.

[0219] <6> The thickness of the wiring board is at least twice the thickness of the capacitor element. <1> ~ <5> 10. The capacitor-embedded substrate according to claim 9, wherein the capacitor-embedded substrate is a capacitor-embedded substrate.

[0220] <7> The sealing insulating layer constituting the wiring board contains glass cloth. <1> ~ <6> 10. The capacitor-embedded substrate according to claim 9, wherein the capacitor-embedded substrate is a capacitor-embedded substrate. [Explanation of symbols]

[0221] 1, 1a, 2, 3, 4, 5 Capacitor built-in board 10 Capacitor section 11 Anode plate 11A core 11B Porous part 12 Cathode layer 13 Dielectric layer 20 Sealing layer 21 First sealing layer 22 Second sealing layer 25 insulating mask layer 30A Capacitor Through Anode Conductor 30B Capacitor through cathode conductor 35A First Capacitor Through Hole 35B Second capacitor through hole 40A through-substrate anode conductor 40A1 First through-substrate anode conductor 40A2 Second through-substrate anode conductor 40B Substrate through cathode conductor 40B1 First through-substrate cathode conductor 40B2 Second through-substrate cathode conductor 45A First PCB Through Hole 45B Second board through hole 48A 1st resin filling section 48B Second resin filling section 50 Sealing insulation layer 51A, 51B 1st wiring layer 52A, 52B 2nd wiring layer 53A, 53B 3rd wiring layer 55A Anode via conductor 55B Cathode via conductor 60 Glass cloth 100, 100a capacitor element 200 wiring board T1 capacitor element thickness T2 wiring board thickness T3 Thickness of the sealing insulation layer α: Center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor β: Center-to-center distance between the first through-substrate anode conductor and the second through-substrate cathode conductor γ: Center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor

Claims

1. a capacitor element; a wiring board incorporating the capacitor element, the capacitor element includes a capacitor portion and a sealing layer provided so as to cover at least one main surface of the capacitor portion; the capacitor section includes 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, at least one first capacitor through-hole and at least one second capacitor through-hole are provided so as to penetrate the capacitor element without penetrating the wiring substrate in the thickness direction of the anode plate; a capacitor through-hole anode conductor is provided inside the first capacitor through-hole and is electrically connected to an end surface of the anode plate; a first substrate through-hole is provided inside the first capacitor through-hole, and a second substrate through-hole is provided inside the second capacitor through-hole, so as to penetrate the wiring substrate and the capacitor element in a thickness direction of the anode plate; a substrate-penetrating anode conductor electrically connected to the anode plate is provided on an inner wall surface of the first substrate-penetrating hole; a substrate through-hole cathode conductor electrically connected to the cathode layer is provided on an inner wall surface of the second substrate through-hole; the substrate through-hole anode conductor is located inside the capacitor through-hole anode conductor; Board with built-in capacitor.

2. a capacitor through-cathode conductor is provided inside the second capacitor through-hole, the capacitor through-cathode conductor being electrically connected to the cathode layer but not electrically connected to the anode plate; the substrate through-cathode conductor is located inside the capacitor through-cathode conductor; The capacitor-embedded substrate according to claim 1 .

3. the through-substrate anode conductors include a first through-substrate anode conductor; the through-substrate cathode conductors include a first through-substrate cathode conductor and a second through-substrate cathode conductor; In a plan view in a thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the first through-substrate anode conductor and the second through-substrate cathode conductor. The capacitor-embedded substrate according to claim 1 or 2.

4. the through-substrate anode conductor further includes a second through-substrate anode conductor; In a plan view in a thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor. The capacitor-embedded substrate according to claim 3 .

5. the through-substrate anode conductors include a first through-substrate anode conductor and a second through-substrate anode conductor; the through-substrate cathode conductor includes a first through-substrate cathode conductor; In a plan view in a thickness direction of the anode plate, a center-to-center distance between the first through-substrate anode conductor and the first through-substrate cathode conductor is equal to a center-to-center distance between the second through-substrate anode conductor and the first through-substrate cathode conductor. The capacitor-embedded substrate according to claim 1 or 2.

6. The thickness of the wiring board is at least twice the thickness of the capacitor element. The capacitor-embedded substrate according to claim 1 or 2.

7. The sealing insulating layer constituting the wiring board contains glass cloth. The capacitor-embedded substrate according to claim 1 or 2.

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