Substrate with built-in capacitor

Abstract

A substrate (1) with a built-in capacitor is provided with: a capacitor element (100); and a wiring substrate (200) in which the capacitor element (100) is built. A capacitor element (100) includes: a capacitor section (10); and a sealing layer (20) provided so as to cover at least one main surface of the capacitor part (10). The capacitor part (10) includes: an anode plate (11) having a porous part (11B) on at least one main surface of a core part (11A); a dielectric layer (13) provided on the surface of the porous part (11B); and a cathode layer (12) provided on the 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 in the thickness direction of the anode plate (11) so as not to pass through the wiring substrate (200) but pass through the capacitor element (100). A capacitor through anode conductor (30A) electrically connected to the end surface of the anode plate (11) is provided inside the first capacitor through hole (35A). A first substrate through-hole (45A) is provided inside the first capacitor through-hole (35A) and a second substrate through-hole (45B) is provided inside the second capacitor through-hole (35B) so as to penetrate the wiring substrate (200) and the capacitor element (100) in the thickness direction of the anode plate (11). A through-substrate anode conductor (40A) electrically connected to the anode plate (11) is provided on the inner wall surface of the first through-substrate hole (45A). A through-substrate cathode conductor (40B) electrically connected to the cathode layer (12) is provided on the inner wall surface of the second through-substrate hole (45B). The substrate through anode conductor (40A) is located inside the capacitor through anode conductor (30A).

Description

Technical Field

[0001] The invention relates to a capacitor built-in substrate. Background Art

[0002] Patent document 1 discloses a module, which includes: a capacitor layer including at least one capacitor part forming a capacitor; a connection terminal; and a through-hole conductor formed in a manner penetrating the capacitor part 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 part in the thickness direction. The first through-hole conductor is electrically connected to the anode of the capacitor part. The capacitor part includes an anode plate made of metal. The first through-hole conductor is connected to the end surface of the anode plate. The module also includes an anode connection layer provided between the first through-hole conductor and the end surface of the anode plate. The first through-hole conductor is connected to the end surface of the anode plate via the anode connection layer. When viewed in a cross-section from a direction orthogonal to the thickness direction, the first through-hole conductor in the portion where the anode connection layer exists protrudes toward the inside of the first through-hole compared to the first through-hole conductor in the portion where the anode connection layer does not exist.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-172255 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] Patent Document 1 describes, as one technical aspect of a module, a capacitor-embedded substrate in which a capacitor element is embedded in a wiring substrate.

[0008] In order to manufacture such a capacitor built-in substrate, the following contents are recorded in Figures 14A and 14B of Patent Document 1: Through holes 263 and 265 are formed in the parts where through-hole conductors 262 and 264 are to be formed by drilling or laser processing, and then the surfaces inside the through holes 263 and 265 are metallized by electroless copper plating or the like to form through-hole conductors 262 and 264.

[0009] At this time, for example, if the through-hole conductor 262 is to be formed in a manner connected to the end surface of the anode plate 231, the anode plate 231 and the conductive portion 220 are simultaneously exposed on the inner surface of the through-hole 263 for the through-hole conductor 262. However, generally speaking, the anode plate 231 is made of a valve-acting metal such as Al (aluminum), while the conductive portion 220 is made of a metal such as Cu (copper), so it is difficult to form the through-hole conductor 262 using a general method such as plating treatment on the surface of the through-hole 263 where the above-mentioned different types of metals are exposed.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a capacitor-embedded substrate in which a capacitor through-anode conductor connected to an end surface of an anode plate can be formed using a general method.

[0011] Solutions for solving problems

[0012] The capacitor built-in substrate of the present invention includes a capacitor element and a wiring substrate in which the capacitor element is built-in. The capacitor element includes a capacitor part and a sealing layer provided in a manner covering at least one main surface of the capacitor part. The capacitor part includes: an anode plate having a porous part on at least one main surface of a core part; a dielectric layer provided on the surface of the porous part; 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 in a manner that does not penetrate the wiring substrate in the thickness direction of the anode plate but penetrates the capacitor element. A capacitor through anode conductor electrically connected to the end surface 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 in a manner that penetrates the wiring substrate and the capacitor element in the thickness direction of the anode plate. A substrate through anode conductor electrically connected to the anode plate is provided on the inner wall surface of the first substrate through hole. A substrate through cathode conductor electrically connected to the cathode layer is provided on the inner wall surface of the second substrate through hole. The substrate through anode conductor is located inside the capacitor through anode conductor.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to provide a capacitor-embedded substrate in which a capacitor through-anode conductor connected to an end surface of an anode plate can be formed using a general method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to the first embodiment of the present invention.

[0016] Figure 2 yes Figure 1A top view of the capacitor built-in substrate along line AA is shown.

[0017] Figure 3 yes Figure 1 A top view of the capacitor-embedded substrate along line BB is shown.

[0018] Figure 4 A~ Figure 4 G is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor element having a capacitor through-anode conductor in a method for manufacturing a capacitor-embedded substrate within the scope of the present invention.

[0019] Figure 5 A~ Figure 5 C is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor-embedded substrate using a capacitor element having a capacitor through-anode conductor.

[0020] Figure 6 A~ Figure 6 D is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor element having no capacitor through-anode conductor in a method for manufacturing a capacitor-embedded substrate outside the scope of the present invention.

[0021] Figure 7 A~ Figure 7 C is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor-embedded substrate using a capacitor element having no capacitor through-anode conductor.

[0022] Figure 8 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a second embodiment of the present invention.

[0023] Fig. 9 yes Figure 8 A top view of the capacitor built-in substrate along line AA is shown.

[0024] Fig.10 yes Figure 8 A top view of the capacitor-embedded substrate along line BB is shown.

[0025] Fig.11 It is a plan view schematically showing an example of a capacitor-embedded substrate according to a third embodiment of the present invention.

[0026] Fig.12 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fourth embodiment of the present invention.

[0027] Fig.13 It 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

[0028] The following is an explanation of the capacitor built-in substrate of the present invention. In addition, the present invention is not limited to the following embodiments, and can also be appropriately changed within the scope of the present invention. In addition, a structure formed by combining multiple preferred structures described in the following embodiments is also the present invention.

[0029] The embodiments shown below are examples, and it is self-evident that parts of the structures shown in different embodiments can be replaced or combined. After the second embodiment, the description of matters common to the first embodiment is omitted, and the differences are mainly described. In particular, the same effects achieved by the same structure are not mentioned one by one in each embodiment.

[0030] In the following description, when the embodiments are not particularly distinguished, they are simply referred to as "capacitor-embedded substrate of the present invention."

[0031] In this specification, terms that express the relationship between elements (such as "vertical", "parallel", "orthogonal", etc.) and terms that express the shape of elements do not express only strict meanings, but express a range of being substantially equal, for example, including a difference of several percentage points. In addition, in this specification, "equal" does not express only completely equal, but expresses substantially equal, for example, including a difference of several percentage points.

[0032] The drawings shown below are schematic diagrams, and their dimensions, aspect ratios, etc. may differ from those of actual products. In the drawings, the same reference numerals are used for the same or equivalent parts. In addition, in each drawing, the same reference numerals are marked for the same elements and repeated descriptions are omitted.

[0033] [First embodiment]

[0034] Figure 1 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to the first embodiment of the present invention. Figure 2 yes Figure 1 A top view of the capacitor built-in substrate along line AA is shown. Figure 3 yes Figure 1 A top view of the capacitor-embedded substrate along line BB is shown.

[0035] Figure 1 The illustrated capacitor built-in substrate 1 includes a capacitor element 100 and a wiring substrate 200 having the capacitor element 100 built therein.

[0036] The capacitor element 100 includes a capacitor unit 10 and a sealing layer 20 provided so as to cover at least one main surface of the capacitor unit 10. Figure 1 In the illustrated example, the sealing layer 20 includes a first sealing layer 21 covering the capacitor portion 10 and a second sealing layer 22 covering the first sealing layer 21 .

[0037] exist Figure 1 In the example shown, one capacitor unit 10 is arranged inside the sealing layer 20. The number of capacitor units 10 arranged inside the sealing layer 20 is not particularly limited, and may be one or more.

[0038] The capacitor unit 10 includes: an anode plate 11 having a porous portion 11B on at least one main surface of a core portion 11A; a dielectric layer 13 provided on the surface of the porous portion 11B; and a cathode layer 12 provided on the surface of the dielectric layer 13. Thus, the capacitor unit 10 constitutes an electrolytic capacitor. Figure 1 In the example shown, the anode plate 11 has the porous portion 11B on both main surfaces of the core portion 11A, but the porous portion 11B may be formed on only one main surface of the core portion 11A.

[0039] Cathode layer 12 includes, for example, a solid electrolyte layer provided on the surface of dielectric layer 13. Preferably, cathode layer 12 further includes a conductor layer provided on the surface of the solid electrolyte layer. When cathode layer 12 includes a solid electrolyte layer, capacitor unit 10 constitutes a solid electrolytic capacitor.

[0040] 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 the respective layers may be the same or different.

[0041] Preferably, if Figure 1 As shown, the sealing layer 20 is provided on two main surfaces facing each other in the thickness direction of the capacitor unit 10. The sealing layer 20 protects the capacitor unit 10.

[0042] In the capacitor built-in substrate 1, the thickness direction of the anode plate 11 (in Figure 1 At least one first capacitor through hole 35A and at least one second capacitor through hole 35B are provided in a manner that does not penetrate the wiring substrate 200 in the vertical direction (in the vertical direction) but penetrates the capacitor element 100. The first capacitor through hole 35A and the second capacitor through hole 35B are arranged separately from each other.

[0043] The planar shape (eg, cross-sectional shape perpendicular to the thickness direction) of the first capacitor through hole 35A is not particularly limited, and is, for example, a circular shape. Similarly, the planar shape of the second capacitor through hole 35B is not particularly limited, and is, for example, a circular shape.

[0044] Preferably, the first capacitor through hole 35A exists in the cathode layer 12 when viewed from the thickness direction of the anode plate 11. Similarly, preferably, the second capacitor through hole 35B exists in the cathode layer 12 when viewed from the thickness direction of the anode plate 11.

[0045] The number of the first capacitor through holes 35A may be the same as the number of the second capacitor through holes 35B, may be smaller than the number of the second capacitor through holes 35B, or may be greater than the number of the second capacitor through holes 35B.

[0046] 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.

[0047] In this specification, the diameter of a through hole refers to a diameter when the planar shape is a circle, and refers to an equivalent circle diameter when the planar shape is other than a circle.

[0048] The diameter of the first capacitor through hole 35A may be constant or different in the thickness direction. Similarly, the diameter of the second capacitor through hole 35B may be constant or different in the thickness direction.

[0049] 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 may be partially or entirely different.

[0050] 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 may be partially or entirely different.

[0051] A capacitor through-anode conductor 30A electrically connected to the end surface of the anode plate 11 is provided inside the first capacitor through-hole 35A.

[0052] In other words, the capacitor through-anode conductor 30A is electrically connected to the anode plate 11 at the inner wall surface of the first capacitor through-hole 35A. Therefore, the insulating material such as the sealing layer 20 is not filled between the capacitor through-anode conductor 30A and the end surface of the anode plate 11.

[0053] Preferably, core 11A and porous portion 11B are exposed to the end surface of anode plate 11 electrically connected to capacitor through-anode conductor 30A. In this case, in addition to core 11A, porous portion 11B is electrically connected to capacitor through-anode conductor 30A.

[0054] Preferably, when viewed from the thickness direction of the anode plate 11, Figure 2 As shown, the capacitor through-anode conductor 30A is electrically connected to the anode plate 11 over the entire circumference of the first capacitor through-hole 35A.

[0055] The capacitor through-anode conductor 30A may be electrically connected to the end surface of the anode plate 11 via the anode connecting layer, or may be directly connected to the end surface of the anode plate 11 .

[0056] When a plurality of first capacitor through holes 35A are provided, some of the first capacitor through holes 35A may not include a capacitor through anode conductor 30A therein, but preferably, all first capacitor through holes 35A include a capacitor through anode conductor 30A therein.

[0057] Furthermore, in capacitor built-in substrate 1 , first substrate through hole 45A is provided inside first capacitor through hole 35A and second substrate through hole 45B is provided inside second capacitor through hole 35B so as to penetrate wiring substrate 200 and capacitor element 100 in the thickness direction of anode plate 11 .

[0058] The planar shape of the first substrate through-hole 45A is not particularly limited, and is, for example, a circular shape. Similarly, the planar shape of the second substrate through-hole 45B is not particularly limited, and is, for example, a circular shape.

[0059] When a plurality of first capacitor through holes 35A are provided, the first capacitor through holes 35A may be included without the first substrate through hole 45A provided inside, but it is preferred that the first substrate through hole 45A be provided inside all the first capacitor through holes 35A. Similarly, when a plurality of second capacitor through holes 35B are provided, the second capacitor through holes 35B may be included without the second substrate through hole 45B provided inside, but it is preferred that the second substrate through hole 45B be provided inside all the second capacitor through holes 35B.

[0060] 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.

[0061] The diameter of the first substrate through-hole 45A may be equal to, smaller than, or larger than the diameter of the second substrate through-hole 45B.

[0062] The diameter of the first substrate through-hole 45A may be constant or different in the thickness direction. Similarly, the diameter of the second substrate through-hole 45B may be constant or different in the thickness direction.

[0063] 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 may be partially or entirely different.

[0064] 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 may be partially or entirely different.

[0065] A substrate through-anode conductor 40A electrically connected to the anode plate 11 is provided on the inner wall surface of the first substrate through-hole 45A. A substrate through-anode conductor 40B electrically connected to the cathode layer 12 is provided on the inner wall surface of the second substrate through-hole 45B.

[0066] like Figure 1 and Figure 2 As shown, the substrate through-anode conductor 40A is located on the inner side of the capacitor through-anode conductor 30A.

[0067] As described later, after the capacitor through-anode conductor 30A is formed in a manner connected to the end surface of the anode plate 11, the substrate through-anode conductor 40A is formed inside the capacitor through-anode conductor 30A, so that the metal constituting the anode plate 11 is not exposed to the inner surface of the first substrate through-hole 45A for forming the substrate through-anode conductor 40A. Therefore, the substrate through-anode conductor 40A can be easily formed using a general method such as plating treatment.

[0068] Furthermore, after forming the capacitor through-anode conductor 30A, when the substrate through-anode conductor 40A is formed at a position different from the capacitor through-anode conductor 30A, the metal constituting the anode plate 11 is not exposed to the inner surface of the first substrate through-hole 45A for forming the substrate through-anode conductor 40A. However, in this case, the area where the function as a capacitor is realized is reduced, the capacitance is reduced, and thus the capacitor performance is reduced. In contrast, by forming the substrate through-anode conductor 40A inside the capacitor through-anode conductor 30A, the area where the function as a capacitor is not realized is reduced, and thus the reduction in capacitor performance can be suppressed.

[0069] Preferably, if Figure 2 As shown, when viewed from the thickness direction of the anode plate 11 , the substrate through-anode conductor 40A is provided over the entire circumference of the inner wall surface of the first substrate through-hole 45A.

[0070] Preferably, if Figure 3 As shown, when viewed from the thickness direction of the anode plate 11 , the substrate through-cathode conductor 40B is provided over the entire circumference of the inner wall surface of the second substrate through-hole 45B.

[0071] Preferably, if Figure 2 and Figure 3 As shown, the diameter of substrate through-anode conductor 40A is equal to the diameter of substrate through-cathode conductor 40B. The diameter of substrate through-anode conductor 40A may be smaller or larger than the diameter of substrate through-cathode conductor 40B.

[0072] In this specification, the diameter of a through conductor refers to a diameter when the planar shape is a circle, and refers to an equivalent circle diameter when the planar shape is other than a circle.

[0073] In particular, it is preferable that the area of ​​the substrate through-anode conductor 40A is equal to the area of ​​the substrate through-cathode conductor 40B when viewed in the thickness direction of the anode plate 11. The area of ​​the substrate through-anode conductor 40A may be smaller than the area of ​​the substrate through-cathode conductor 40B, or may be larger than the area of ​​the substrate through-cathode conductor 40B.

[0074] The material constituting the substrate through-anode conductor 40A may be the same as or different from the material constituting the substrate through-cathode conductor 40B.

[0075] The material constituting the capacitor through-anode conductor 30A may be the same as or different from the material constituting the substrate through-anode conductor 40A.

[0076] Preferably, if Figure 1 As shown in FIG. 1 , an insulating material such as a sealing layer 20 is filled between the substrate through-anode conductor 40A and the capacitor through-anode conductor 30A. Figure 1 In the illustrated example, the second sealing layer 22 is filled between the substrate through-anode conductor 40A and the capacitor through-anode conductor 30A.

[0077] In addition, it is preferable that an insulating material such as a sealing layer 20 is filled between the substrate-penetrating cathode conductor 40B and the end surface of the anode plate 11. Figure 1 In the illustrated example, the first sealing layer 21 is filled between the substrate through-cathode conductor 40B and the end surface of the anode plate 11 .

[0078] It can also be, Figure 1 As shown, capacitor element 100 further includes insulating shielding layer 25 provided around first capacitor through hole 35A on at least one main surface of anode plate 11. Preferably, insulating shielding layer 25 provided around first capacitor through hole 35A is provided between capacitor through anode conductor 30A and cathode layer 12.

[0079] In addition, the capacitor element 100 may further include an insulating shielding layer 25 provided around the second capacitor through hole 35B on at least one main surface of the anode plate 11. Preferably, the insulating shielding layer 25 provided around the second capacitor through hole 35B is provided on the insulating material filled between the substrate through cathode conductor 40B and the capacitor portion 10 (in Figure 1 The middle is between the first sealing layer 21) and the cathode layer 12.

[0080] exist Figure 1 Although not shown in the figure, the capacitor unit 10 may also include an insulating shielding layer 25 provided on at least one main surface of the anode plate 11 so as to surround the cathode layer 12. By surrounding the cathode layer 12 with the insulating shielding layer 25, insulation between the anode plate 11 and the cathode layer 12 is ensured to prevent a short circuit between the two. The insulating shielding layer 25 may be provided in a partial manner surrounding the cathode layer 12, or in a manner surrounding the entire cathode layer 12.

[0081] It can also be, Figure 1 As shown in FIG. 1 , a first resin filling portion 48A filled with a resin material is provided inside the substrate through-anode conductor 40A. In this case, the first resin filling portion 48A is provided in a space surrounded by the substrate through-anode conductor 40A in the first substrate through-hole 45A. If the space in the first substrate through-hole 45A is eliminated by providing the first resin filling portion 48A, the occurrence of delamination of the substrate through-anode conductor 40A is suppressed. In addition, the first resin filling portion 48A may be either a conductor or an insulator.

[0082] In addition, a second resin filling portion 48B filled with a resin material may be provided inside the substrate through cathode conductor 40B. In this case, the second resin filling portion 48B is provided in a space surrounded by the substrate through cathode conductor 40B in the second substrate through hole 45B. If the space in the second substrate through hole 45B is eliminated by providing the second resin filling portion 48B, delamination of the substrate through cathode conductor 40B is suppressed. In addition, the second resin filling portion 48B may be either a conductor or an insulator.

[0083] exist Figure 1 In the illustrated example, the first wiring layers 51A and 51B are provided between the first sealing layer 21 and the second sealing layer 22 , and the second wiring layers 52A and 52B are provided on the surface of the second sealing layer 22 .

[0084] exist Figure 1In the embodiment, 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 side. 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 side.

[0085] The wiring substrate 200 includes, for example, a sealing insulating layer 50. Figure 1 In the example shown, the wiring substrate 200 includes a sealing insulating layer 50 .

[0086] 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.

[0087] Preferably, if Figure 1 As shown in FIG. 1 , the sealing insulating layer 50 is provided on two main surfaces of the capacitor element 100 that are opposite to each other in the thickness direction. Figure 1 As shown, in addition to the two main surfaces of capacitor element 100 , at least a portion of the side surfaces of capacitor element 100 is also covered by sealing insulating layer 50 .

[0088] exist Figure 1 In the illustrated example, third wiring layers 53A and 53B are provided on the surface of the sealing insulating layer 50 .

[0089] exist Figure 1 In the embodiment of the present invention, the third wiring layers 53A and 53B are provided on both the upper side and the lower side of the capacitor element 100 , but may be provided on only one side.

[0090] The first wiring layer 51A is electrically connected to the capacitor through-anode conductor 30A. Figure 1 In the illustrated example, the first wiring layer 51A is connected to the end of the capacitor through-anode conductor 30A.

[0091] The second wiring layer 52A is electrically connected to the first wiring layer 51A. The second wiring layer 52A is connected to the first wiring layer 51A via, for example, an anode via conductor 55A that penetrates the second sealing layer 22 .

[0092] Furthermore, the second wiring layer 52A is electrically connected to the substrate penetrating anode conductor 40A. Figure 1 In the illustrated example, the substrate-penetrating anode conductor 40A is connected to the end of the second wiring layer 52A.

[0093] The third wiring layer 53A is electrically connected to the substrate penetrating anode conductor 40A. Figure 1In the illustrated example, the third wiring layer 53A is connected to the end of the substrate through-hole anode conductor 40A.

[0094] As described above, the third wiring layer 53A is electrically connected to the anode plate 11 via the substrate through-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.

[0095] 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 via, for example, a cathode via conductor 55B that penetrates the first sealing layer 21.

[0096] Furthermore, the first wiring layer 51B is electrically connected to the substrate through cathode conductor 40B. Figure 1 In the illustrated example, the substrate-penetrating cathode conductor 40B is connected to the end of the first wiring layer 51B.

[0097] The second wiring layer 52B is electrically connected to the substrate through cathode conductor 40B. Figure 1 In the example shown, the substrate-penetrating cathode conductor 40B is connected to the end of the second wiring layer 52B. Figure 1 Although not shown in the figure, the second wiring layer 52B may be connected to the first wiring layer 51B via a cathode via conductor penetrating the second sealing layer 22 .

[0098] The third wiring layer 53B is electrically connected to the substrate through cathode conductor 40B. Figure 1 In the illustrated example, the third wiring layer 53B is connected to the end portion of the substrate through-cathode conductor 40B.

[0099] As described above, the third wiring layer 53B is electrically connected to the cathode layer 12 via the substrate-penetrating cathode conductor 40B, the second wiring layer 52B, the first wiring layer 51B, and the cathode via conductor 55B.

[0100] Figure 1 The capacitor-embedded substrate 1 shown is produced, for example, by the following method.

[0101] Figure 4 A~ Figure 4 1 is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor element having a capacitor through-anode conductor in a method for manufacturing a capacitor-embedded substrate within the scope of the present invention.

[0102] exist Figure 4 In A, a capacitor portion 10 is prepared.

[0103] For example, the anode plate 11 having the porous portion 11B on at least one main surface of the core portion 11A is subjected to anodization treatment to form the dielectric layer 13 on the surface of the porous portion 11B.

[0104] Alternatively, a chemically formed foil may be prepared as the anode plate 11 in which the dielectric layer 13 is provided on the surface of the porous portion 11B.

[0105] Next, in the region including the region where the first capacitor through hole 35A is to be formed (see Figure 4 D) and the second capacitor through hole 35B (refer to Figure 4 The insulating shielding layer 25 is formed in the region of the portion B). For example, the insulating shielding layer 25 is formed in a predetermined region by applying an insulating resin to the surface of the dielectric layer 13 by screen printing, dispenser coating, or the like.

[0106] Next, cathode layer 12 is formed in a region of the surface of dielectric layer 13 where insulating shielding layer 25 is not provided. For example, as cathode layer 12, a solid electrolyte layer and a conductor layer are sequentially formed on the surface of dielectric layer 13. Capacitor unit 10 is obtained by the above method.

[0107] exist Figure 4 In B, a second capacitor through hole 35B is formed so as to penetrate the capacitor portion 10 .

[0108] For example, by drilling, laser processing, or the like, the second capacitor through hole 35B is formed so as to penetrate the insulating shielding layer 25 and the anode plate 11 in the thickness direction.

[0109] exist Figure 4 In C, the two main surfaces of the capacitor unit 10 are covered with the first sealing layer 21. Preferably, Figure 4 As shown in FIG. 3C , the second capacitor through hole 35B is filled with the first sealing layer 21 .

[0110] exist Figure 4 In D, a first capacitor through hole 35A is formed so as to penetrate the capacitor portion 10 and the first sealing layer 21 .

[0111] For example, by drilling, laser processing, or the like, the first capacitor through hole 35A is formed so as to penetrate the first sealing layer 21 , the insulating shielding layer 25 , and the anode plate 11 in the thickness direction.

[0112] like Figure 4 As shown in D, metal other than the anode plate 11 is not exposed on the inner surface of the first capacitor through hole 35A.

[0113] exist Figure 4 In E, a capacitor through-anode conductor 30A is formed on the inner wall surface of the first capacitor through-hole 35A.

[0114] For example, the capacitor through-anode conductor 30A is formed by metalizing 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-anode conductor 30A, for example, the inner wall surface of the first capacitor through-hole 35A is metalized by electroless copper plating, electrolytic copper plating, or the like, so that processing becomes easy. In addition, as a method for forming the capacitor through-anode conductor 30A, in addition to the method of metalizing the inner wall surface of the first capacitor through-hole 35A, a method of filling the first capacitor through-hole 35A with a metal, a composite material of a metal and a resin, or the like may be used.

[0115] According to the above method, the capacitor through-anode conductor 30A connected to the end surface of the anode plate 11 is formed.

[0116] exist Figure 4 In F, the cathode via conductor 55B, the first wiring layer 51A, and the first wiring layer 51B are formed in predetermined regions.

[0117] The cathode via conductor 55B is formed, for example, by forming a through hole penetrating 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 the through hole with a conductive paste and then performing a heat treatment.

[0118] The first wiring layer 51A and the first wiring layer 51B are formed by, for example, plating the surface of the first sealing layer 21 .

[0119] exist Figure 4 In G, the sealing layer 20 is formed by covering the first sealing layer 21, the first wiring layer 51A and the first wiring layer 51B with the second sealing layer 22. Preferably, as Figure 4 As shown in G, the first capacitor through hole 35A is filled with the second sealing layer 22. Thereafter, the anode via conductor 55A, the second wiring layer 52A, and the second wiring layer 52B are formed in predetermined regions.

[0120] The anode via conductor 55A is formed, for example, by forming a through hole penetrating 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 the through hole with a conductive paste and then performing a heat treatment.

[0121] The second wiring layer 52A and the second wiring layer 52B are formed by, for example, plating the surface of the second sealing layer 22 .

[0122] According to the above method, capacitor element 100 is manufactured.

[0123] Figure 5 A~ Figure 5C is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor-embedded substrate using a capacitor element having a capacitor through-anode conductor.

[0124] exist Figure 5 In A, capacitor element 100 is covered with sealing insulating layer 50 .

[0125] For example, sealing insulating layer 50 is formed by covering capacitor element 100 with a sealing material having a metal foil such as copper foil on the surface.

[0126] exist Figure 5 In B, the first substrate through hole 45A and the second substrate through hole 45B are formed so as to penetrate the sealing insulating layer 50 , the sealing layer 20 , and the capacitor portion 10 .

[0127] For example, the first substrate through hole 45A is formed by drilling, laser processing, or the like inside the first capacitor through hole 35A. At this time, the diameter of the first substrate through hole 45A is made smaller than the diameter of the first capacitor through hole 35A, so that an insulating material such as the second sealing layer 22 exists between the inner wall surface of the first capacitor through hole 35A and the inner wall surface of the first substrate through hole 45A in the plane direction.

[0128] Similarly, the second substrate through hole 45B is formed by drilling, laser processing, or the like inside the second capacitor through hole 35B. At this time, the diameter of the second substrate through hole 45B is made smaller than the diameter of the second capacitor through hole 35B, so that the insulating material such as the first sealing layer 21 exists between the inner wall surface of the second capacitor through hole 35B and the inner wall surface of the second substrate through hole 45B in the plane direction.

[0129] like Figure 5 As shown in B, the anode plate 11 is not exposed to 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 second wiring layer 52A and other wiring layers is exposed to the inner surface of the first substrate through hole 45A and the inner surface of the second substrate through hole 45B.

[0130] exist Figure 5 In C, a substrate through-anode conductor 40A is formed on the inner wall surface of a first substrate through-hole 45A, and a substrate through-cathode conductor 40B is formed on the inner wall surface of a second substrate through-hole 45B.

[0131] For example, the substrate through-anode conductor 40A is formed by metalizing 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 substrate through-anode conductor 40A, for example, by metalizing the inner wall surface of the first substrate through-hole 45A with a non-electrolytic copper plating process, an electrolytic copper plating process, or the like, processing becomes easy. In addition, as for the method of forming the substrate through-anode conductor 40A, in addition to the method of metalizing the inner wall surface of the first substrate through-hole 45A, a method of filling the first substrate through-hole 45A with a metal, a composite material of a metal and a resin, or the like may be used. The method of forming the substrate through-cathode conductor 40B is the same. The substrate through-anode conductor 40A and the substrate through-cathode conductor 40B may be formed simultaneously or separately.

[0132] Preferably, if Figure 5 As shown in C, the first resin filling portion 48A and the second resin filling portion 48B are formed, and the third wiring layer 53A and the third wiring layer 53B are formed.

[0133] According to the above method, capacitor built-in substrate 1 in which capacitor element 100 is built in wiring substrate 200 is manufactured.

[0134] on the other hand, Figure 6 A~ Figure 6 D is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor element having no capacitor through-anode conductor in a method for manufacturing a capacitor-embedded substrate outside the scope of the present invention.

[0135] exist Figure 6 In A, Figure 4 Similarly, prepare the capacitor unit 10.

[0136] exist Figure 6 In B, Figure 4 Similarly to B, a second capacitor through hole 35B is formed to penetrate the capacitor portion 10 .

[0137] exist Figure 6 In C, with Figure 4 Similarly, the first sealing layer 21 covers both main surfaces of the capacitor unit 10. Preferably, Figure 6 As shown in FIG. C, the second capacitor through hole 35B is filled with the first sealing layer 21. Figure 6 In the example shown in C, the sealing layer 20 is formed from the first sealing layer 21 .

[0138] exist Figure 6 In D, Figure 4 Similarly to F, the cathode via conductor 55B, the first wiring layer 51A, and the first wiring layer 51B are formed in predetermined regions.

[0139] According to the above method, capacitor element 100 a is formed.

[0140] Figure 7 A~ Figure 7 C is a cross-sectional view schematically showing an example of a method for manufacturing a capacitor-embedded substrate using a capacitor element having no capacitor through-anode conductor.

[0141] exist Figure 7 In A, Figure 5 Similarly, capacitor element 100 a is covered with sealing insulating layer 50 .

[0142] exist Figure 7 In B, Figure 5 Similarly to B, the first substrate through hole 45A and the second substrate through hole 45B are formed so as to penetrate the sealing insulating layer 50 , the sealing layer 20 , and the capacitor unit 10 .

[0143] and Figure 5 Different from B, Figure 7 In B, not only the metal constituting the wiring layers such as the first wiring layer 51A but also the anode plate 11 is exposed on the inner surface of the first substrate through-hole 45A.

[0144] exist Figure 7 In C, with Figure 5 Similarly, a substrate through-hole anode conductor 40A is formed on the inner wall surface of the first substrate through-hole 45A, and a substrate through-hole cathode conductor 40B is formed on the inner wall surface of the second substrate through-hole 45B.

[0145] According to the above method, capacitor built-in substrate 1 a in which capacitor element 100 a is built in wiring substrate 200 is manufactured.

[0146] As described above, in the method of manufacturing the built-in capacitor substrate 1 a , a different type of metal is exposed on the inner surface of the first substrate through-hole 45A, so it is difficult to form the substrate through-anode conductor 40A using a general method such as plating.

[0147] In contrast, in the method of manufacturing the capacitor-embedded substrate 1 , the different type of metal is not exposed to the inner surface of the first substrate through-hole 45A, so the substrate through-anode conductor 40A can be easily formed using a common method such as plating.

[0148] [Second embodiment]

[0149] In the capacitor-embedded substrate according to the second embodiment of the present invention, a capacitor through cathode conductor is provided inside the second capacitor through hole.

[0150] Figure 8It 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 yes Figure 8 A top view of the capacitor built-in substrate along line AA is shown. Fig.10 yes Figure 8 A top view of the capacitor-embedded substrate along line BB is shown.

[0151] exist Figure 8 In the illustrated capacitor-embedded substrate 2 , a capacitor through-cathode conductor 30B which 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.

[0152] like Figure 8 and Fig.10 As shown, the substrate through-cathode conductor 40B is located inside the capacitor through-cathode conductor 30B.

[0153] Figure 8 The capacitor built-in substrate 2 shown includes the capacitor through cathode conductor 30B and the Figure 1 The capacitor-embedded substrate 1 shown has a common structure.

[0154] In addition to providing capacitor through-anode conductor 30A inside first capacitor through-hole 35A, capacitor through-cathode conductor 30B is provided inside second capacitor through-hole 35B, thereby further improving the adhesion strength between layers constituting capacitor element 100. As a result, defects such as peeling between layers can be suppressed.

[0155] When a plurality of 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 therein, but preferably, all of the second capacitor through holes 35B have capacitor through cathode conductors 30B provided therein.

[0156] Preferably, if Figure 8 As shown in FIG. 1 , an insulating material such as a sealing layer 20 is filled between the capacitor through cathode conductor 30B and the end surface of the anode plate 11. Figure 8 In the illustrated example, the first sealing layer 21 is filled between the capacitor through-cathode conductor 30B and the end surface of the anode plate 11 .

[0157] In addition, 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 may be filled between the substrate through cathode conductor 40B and the capacitor through cathode conductor 30B, 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.

[0158] Preferably, if Fig.10 As shown, when viewed from the thickness direction of the anode plate 11 , the capacitor through cathode conductor 30B is provided along the entire periphery of the second capacitor through hole 35B.

[0159] Preferably, if Fig. 9 and Fig.10 As shown, the diameter of the capacitor through-anode conductor 30A is equal to the diameter of the capacitor through-cathode conductor 30B. The diameter of the capacitor through-anode conductor 30A may be smaller or larger than the diameter of the capacitor through-cathode conductor 30B.

[0160] In particular, it is preferable that the area of ​​the capacitor through-anode conductor 30A is equal to the area of ​​the capacitor through-cathode conductor 30B when viewed in the thickness direction of the anode plate 11. The area of ​​the capacitor through-anode conductor 30A may be smaller than the area of ​​the capacitor through-cathode conductor 30B, or may be larger than the area of ​​the capacitor through-cathode conductor 30B.

[0161] The material constituting the capacitor through-anode conductor 30A may be the same as or different from the material constituting the capacitor through-cathode conductor 30B.

[0162] 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.

[0163] Preferably, if Figure 8 As shown in FIG. 1 , the capacitor through-cathode conductor 30B is electrically connected to the first wiring layer 51B. Figure 8 In the illustrated example, the first wiring layer 51B is connected to the end of the capacitor through-cathode conductor 30B.

[0164] [Third Embodiment]

[0165] In the capacitor built-in substrate of the third embodiment of the present invention, when looking down from the thickness direction of the anode plate, the center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to the center distance between the first substrate through-anode conductor and the second substrate through-cathode conductor, or the center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to the center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

[0166] In the third embodiment of the present invention, by making the center distances between substrate through-anode conductors and substrate through-cathode conductors uniform, the impedance difference between current paths can be reduced, and the heat generation of the capacitor element can be dispersed to increase the current capacity.

[0167] In this specification, the center of the substrate-through anode conductor or the center of the substrate-through cathode conductor refers to the center of the smallest circle that contains the substrate-through anode conductor or the substrate-through cathode conductor when viewed from the thickness direction of the anode plate. Therefore, the distance between the centers of the substrate-through anode conductor and the substrate-through cathode conductor refers to the length of the line segment connecting the center of the substrate-through anode conductor and the center of the substrate-through cathode conductor obtained by the above method. The same is true for the distance between the centers of the substrate-through anode conductor and the substrate-through anode conductor and the distance between the centers of the substrate-through cathode conductor and the substrate-through cathode conductor.

[0168] In the third embodiment of the present invention, the capacitor through-cathode conductor may not be provided like the first embodiment, or the capacitor through-cathode conductor may be provided like the second embodiment.

[0169] Fig.11 It is a plan view schematically showing an example of a capacitor-embedded substrate according to a third embodiment of the present invention. Fig.11 The top view shown is with Figure 2 and Figure 3 Top view of the same location.

[0170] exist Fig.11 In the capacitor built-in substrate 3 shown, the substrate through-anode conductor 40A and the substrate through-cathode conductor 40B are arranged in a hexagonal shape as a whole. In the hexagonal arrangement, the substrate through-anode conductor 40A or the substrate through-cathode conductor 40B is arranged at each vertex of a regular hexagon and at the center of the regular hexagon. Fig.11 In the example shown, the substrate-penetrating anode conductors 40A and substrate-penetrating cathode conductors 40B are arranged alternately from the left side toward the right side. In addition, when the substrate-penetrating anode conductors 40A and substrate-penetrating cathode conductors 40B are arranged hexagonally as a whole, the arrangement of the substrate-penetrating anode conductors 40A and substrate-penetrating cathode conductors 40B is not particularly limited, and for example, the substrate-penetrating anode conductors 40A and substrate-penetrating cathode conductors 40B may be arranged alternately in pairs from the left side toward the right side.

[0171] Preferably, if Fig.11 As shown, when viewed from the thickness direction of the anode plate 11, the center distance between the first substrate through-anode conductor 40A1 and the first substrate through-cathode conductor 40B1 is ( Fig.11 The length represented by α in the figure) and the distance between the centers of the first substrate through-anode conductor 40A1 and the second substrate through-cathode conductor 40B2 ( Fig.11 The length of β in is equal.

[0172] In addition, it is preferable that the center distance between the first substrate through-anode conductor 40A1 and the first substrate through-cathode conductor 40B1 is ( Fig.11 The length represented by α in the figure) and the center distance between the second substrate through-anode conductor 40A2 and the first substrate through-cathode conductor 40B1 ( Fig.11 The length of γ in is equal.

[0173] It can also be, with Fig.11 Unlike the configuration shown, the substrate-through anode conductor 40A and the substrate-through cathode conductor 40B are arranged as a square as a whole. In the square configuration, the substrate-through anode conductor 40A or the substrate-through cathode conductor 40B is arranged at each vertex of the square shape. For example, the substrate-through anode conductor 40A and the substrate-through cathode conductor 40B are arranged alternately from the upper side to the lower side, and the substrate-through anode conductor 40A and the substrate-through cathode conductor 40B are arranged alternately from the left side to the right side. In addition, in the case where the substrate-through anode conductor 40A and the substrate-through cathode conductor 40B are arranged as a square as a whole, the arrangement of the substrate-through anode conductor 40A and the substrate-through cathode conductor 40B is not particularly limited. For example, two substrate-through anode conductors 40A and substrate-through cathode conductors 40B are arranged alternately from the upper side to the lower side, and two substrate-through anode conductors 40A and substrate-through cathode conductors 40B are arranged alternately from the left side to the right side.

[0174] [Fourth embodiment]

[0175] 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.

[0176] In the fourth embodiment of the present invention, even when 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 substrate. As a result, the rigidity of the capacitor-embedded substrate can be increased.

[0177] Fig.12 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fourth embodiment of the present invention.

[0178] exist Fig.12 In the capacitor built-in substrate 4 shown in FIG. 1 , when the thickness of the capacitor element 100 is set to T 1 , the thickness of the wiring substrate 200 is set to T 2 When the thickness T of the wiring substrate 200 is 2 is the thickness T of the capacitor element 100 1 More than twice.

[0179] Preferably, the thickness T of the wiring substrate 200 is2 is the thickness T of the capacitor element 100 1 More preferably, the thickness T of the wiring substrate 200 is 2.5 times greater than that of the wiring substrate 200. 2 is the thickness T of the capacitor element 100 1 On the other hand, the thickness T of the wiring substrate 200 is 2 For example, the thickness T of the capacitor element 100 1 Less than 5 times.

[0180] The thickness T of the wiring substrate 200 2 There is no particular limitation, but for example, it is not less than 0.6 mm and not more than 2.0 mm.

[0181] exist Fig.12 In the capacitor built-in substrate 4 shown in FIG. 1 , when the thickness of the sealing insulating layer 50 is set to T 3 When the thickness T of the sealing insulating layer 50 provided on one surface of the capacitor element 100 is 3 The thickness T of the sealing insulating layer 50 provided on the other surface of the capacitor element 100 may be 3 The same, or different.

[0182] The other structures are the same as those of the first to third embodiments.

[0183] [Fifth embodiment]

[0184] In the capacitor-embedded substrate according to the fifth embodiment of the present invention, the sealing insulating layer constituting the wiring substrate includes glass cloth. This can improve the rigidity of the capacitor-embedded substrate.

[0185] Fig.13 It is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a fifth embodiment of the present invention.

[0186] exist Fig.13 In the illustrated capacitor built-in substrate 5, the sealing insulating layer 50 constituting the wiring substrate 200 includes a glass cloth 60. The glass cloth 60 is formed by weaving glass yarns in a lattice shape, for example.

[0187] The glass cloth 60 may be included in the entire sealing insulating layer 50 or may be included in a biased manner in a part of the sealing insulating layer 50. Fig.13 In the example shown, a plurality of glass cloths 60 are stacked at intervals in the thickness direction. Each layer of the glass cloth 60 is arranged along the plane direction.

[0188] The sealing insulating layer 50 including the glass cloth 60 is formed using, for example, a prepreg in which the glass cloth is impregnated with an insulating resin in advance.

[0189] The other structures are the same as those of the first to fourth embodiments.

[0190] Hereinafter, the detailed structure of capacitor element 100 will be described.

[0191] Either one capacitor unit 10 or a plurality of capacitor units 10 may be disposed inside the sealing layer 20. When a plurality of capacitor units 10 are disposed inside the sealing layer 20, it is preferred that adjacent capacitor units 10 are spaced apart from each other in the thickness direction (e.g., Figure 1 The through groove that penetrates the capacitor portion 10 in the vertical direction (in the vertical direction) is disconnected. In this case, it is preferable that the through groove is filled with an insulating material such as a sealing layer 20.

[0192] When adjacent capacitor parts 10 are disconnected from each other by through grooves, adjacent capacitor parts 10 can be physically disconnected from each other by through grooves. Therefore, adjacent capacitor parts 10 can be electrically disconnected or electrically connected. The width of the through groove, that is, the interval between adjacent capacitor parts 10, can be constant in the thickness direction or can be reduced in the thickness direction.

[0193] When a plurality of capacitor units 10 are arranged inside the sealing layer 20, the plurality of capacitor units 10 may be arranged in a plane direction orthogonal to the thickness direction, or may be arranged in a stacked manner in the thickness direction, or may be arranged in a combination of the two. The plurality of capacitor units 10 may be arranged regularly or irregularly. The size and shape of the capacitor units 10 may be the same, or may be partially or completely different. Preferably, the structures of the capacitor units 10 are the same, but capacitor units 10 with different structures may also be included.

[0194] As the plane shape of the capacitor part 10 when viewed from the thickness direction, for example, a rectangle (square or rectangular), a quadrilateral other than a rectangle, a triangle, a pentagon, a hexagon or other polygon, a circle, an ellipse, a shape formed by combining these shapes, etc. In addition, the plane shape of the capacitor part 10 may also be an L-shape, a C-shape (Japanese コ-shape), a step shape, etc.

[0195] Preferably, the anode plate 11 is made of a so-called valve metal that exhibits a valve action. Examples of the valve metal include metal monomers such as aluminum, tantalum, niobium, titanium, and zirconium, or alloys containing at least one of these metals. Among them, aluminum or an aluminum alloy is preferred.

[0196] The shape of the anode plate 11 is preferably a flat plate, and more preferably a foil. Thus, in this specification, "plate-like" also includes "foil-like".

[0197] The anode plate 11 may have the porous portion 11B on at least one main surface of the core 11A. That is, the anode plate 11 may have the porous portion 11B on only one main surface of the core 11A, or may have the porous portion 11B on both main surfaces of the core 11A. The porous portion 11B is preferably a porous layer formed on the surface of the core 11A, and more preferably an etching layer.

[0198] The thickness of the anode plate 11 before etching is preferably 60 μm or more and 200 μm or less. The thickness of the core 11A that is not etched after etching is preferably 15 μm or more and 70 μm or less. The thickness of the porous portion 11B is designed to match the required withstand voltage and electrostatic capacity, but preferably, the porous portions 11B on both sides of the core 11A are 10 μm or more and 180 μm or less in total.

[0199] The pore size of the porous portion 11B is preferably 10 nm or more and 600 nm or less. The pore size of the porous portion 11B refers to a median diameter D50 measured by a mercury porosimeter. The pore size of the porous portion 11B can be controlled by adjusting various conditions during etching, for example.

[0200] The dielectric layer 13 provided on the surface of the porous portion 11B is porous reflecting the surface state of the porous portion 11B and has a fine concavoconvex surface shape. Preferably, the dielectric layer 13 is composed of an oxide film of the above-mentioned valve-action metal. For example, when an aluminum foil is used as the anode plate 11, the surface of the aluminum foil is subjected to an anodic oxidation treatment (also called chemical conversion treatment) in an aqueous solution containing ammonium adipate or the like, so that the dielectric layer 13 composed of an oxide film can be formed.

[0201] The thickness of the dielectric layer 13 is designed in accordance with the required withstand voltage and electrostatic capacitance, but is preferably not less than 10 nm and not more than 100 nm.

[0202] In the case where the cathode layer 12 includes a solid electrolyte layer, as a material constituting the solid electrolyte layer, for example, conductive polymers such as polypyrroles, polythiophenes, and polyanilines can be cited. Among them, polythiophenes are preferred, and poly (3,4-ethylenedioxythiophene) called PEDOT is particularly preferred. In addition, the above-mentioned conductive polymer may also contain dopants such as polystyrene sulfonic acid (PSS). In addition, it is preferred that the solid electrolyte layer includes an inner layer filling the pores (recesses) of the dielectric layer 13 and an outer layer covering the dielectric layer 13.

[0203] The thickness of the solid electrolyte layer from the surface of porous portion 11B is preferably 2 μm or more and 20 μm or less.

[0204] 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 solution containing a monomer such as 3,4-ethylenedioxythiophene, or by a method of applying a dispersion of a polymer such as poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 13 and drying it.

[0205] 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 coating, or inkjet printing.

[0206] When the cathode layer 12 includes a conductor layer, the conductor layer includes at least one of a conductive resin layer and a metal layer. The conductor layer may be only a conductive resin layer or only a metal layer. Preferably, the conductor layer covers the entire surface of the solid electrolyte layer.

[0207] Examples of the conductive resin layer include a conductive adhesive layer containing at least one conductive filler selected from the group consisting of a silver filler, a copper filler, a nickel filler, and a carbon filler.

[0208] As the metal layer, for example, metal plating, metal foil, etc. can be cited. Preferably, the metal layer is composed of at least one metal selected from the group consisting of nickel, copper, silver, and alloys containing these metals as main components. In addition, the "main component" refers to the element component with the largest weight ratio.

[0209] The conductor 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.

[0210] The carbon layer is provided to electrically and mechanically connect the solid electrolyte layer to the copper layer. The carbon layer can be formed in a predetermined area by applying carbon paste to the surface of the solid electrolyte layer by sponge transfer, screen printing, dispenser coating, inkjet printing, etc. The thickness of the carbon layer is preferably 2 μm or more and 20 μm or less.

[0211] The copper layer can be formed in a predetermined region by applying a copper paste to the surface of the carbon layer by sponge transfer, screen printing, spray coating, dispenser coating, inkjet printing, etc. The thickness of the copper layer is preferably 2 μm or more and 20 μm or less.

[0212] The sealing layer 20 is made of an insulating material. In this case, it is preferable that the sealing layer 20 contains an insulating resin.

[0213] Examples of the insulating resin contained in the sealing layer 20 include epoxy resin and phenol resin.

[0214] Preferably, the sealing layer 20 further contains a filler such as an inorganic filler.

[0215] Examples of the inorganic filler contained in the sealing layer 20 include silicon oxide particles and aluminum oxide particles.

[0216] A layer such as a stress relaxation layer or a moisture-proof film may be provided between the capacitor unit 10 and the sealing layer 20 .

[0217] The insulating shielding layer 25 is made of an insulating material. In this case, it is preferable that the insulating shielding layer 25 contains an insulating resin.

[0218] Examples of the insulating resin contained in the insulating shielding layer 25 include polyphenylsulfone resin, polyethersulfone resin, cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), polyimide resin, polyamide-imide resin, epoxy resin, and derivatives or precursors thereof.

[0219] The insulating shielding layer 25 may be made of the same resin as the sealing layer 20. If the insulating shielding layer 25 contains an inorganic filler different from the sealing layer 20, it may adversely affect the effective capacitance of the capacitor unit 10. Therefore, the insulating shielding layer 25 is preferably made of a separate type of resin.

[0220] The insulating shielding layer 25 can be formed in a predetermined region by applying a shielding material such as a composition containing an insulating resin to the surface of the porous portion 11B by a method such as sponge transfer, screen printing, dispenser coating, or inkjet printing.

[0221] The insulating shielding layer 25 may be formed in the porous portion 11B before or after the dielectric layer 13 is formed.

[0222] It is preferable that the constituent materials of the first wiring layer 51A and the first wiring layer 51B are the same in at least the type, but they may be different from each other.

[0223] Preferably, the constituent materials of the second wiring layer 52A and the second wiring layer 52B are the same in at least type, but may be different from each other. Preferably, the constituent materials of the second wiring layer 52A and the second wiring layer 52B are the same as the constituent materials of the first wiring layer 51A and the first wiring layer 51B.

[0224] Preferably, the constituent materials of the third wiring layer 53A and the third wiring layer 53B are the same as each other at least in terms of type, but may be different from each other. Preferably, the constituent materials of the third wiring layer 53A and the third wiring layer 53B are 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.

[0225] 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. If the anode connection layer functions as a barrier layer for the anode plate 11, the dissolution of the anode plate 11 that occurs during the treatment of the chemical solution for forming the first wiring layer 51A and other wiring layers is suppressed, and further, the infiltration of the chemical solution into the capacitor portion 10 is suppressed, so that the reliability is easily improved.

[0226] Preferably, the anode connection layer includes a layer containing nickel as a main component. In this case, damage to the metal (for example, aluminum) constituting the anode plate 11 is reduced, so the barrier property of the anode connection layer to the anode plate 11 is easily improved.

[0227] Alternatively, the capacitor through-hole anode conductor 30A may be directly connected to the end surface of the anode plate 11 .

[0228] The built-in capacitor 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 regarding the structure of the capacitor element or wiring substrate, the manufacturing conditions of the built-in capacitor substrate, and the like.

[0229] In addition, the indirect through-conductor technology using the substrate through-conductor of the capacitor built-in substrate of the present invention is not limited to the electrolytic capacitors described so far, and can also be applied to other capacitor elements. For example, in a laminated ceramic capacitor having a first electrode and a second electrode, the effect of the present invention can also be provided in a structure in which the first electrode and the second electrode are buried inside the substrate in a manner opposite to each other in the thickness direction of the substrate.

[0230] The built-in capacitor 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 built-in capacitor substrate of the present invention; and an electronic component electrically connected to the built-in capacitor substrate (for example, an external electrode layer).

[0231] In the composite electronic component, the electronic component electrically connected to the built-in capacitor substrate may be either a passive component or an active component. Both the passive component and the active component may be electrically connected to the built-in capacitor substrate, or either the passive component or the active component may be electrically connected to the built-in capacitor substrate. In addition, a composite of the passive component and the active component may be electrically connected to the built-in capacitor substrate.

[0232] Examples of passive components include inductors, etc. Examples of active components include memories, GPUs (Graphic Processing Units), CPUs (Central Processing Units), MPUs (Micro Processing Units), and PMICs (Power Management ICs).

[0233] The capacitor built-in substrate of the present invention has a sheet-like shape as a whole. Therefore, in the composite electronic component, the capacitor built-in substrate can be treated like a mounting substrate, and the electronic component can be mounted on the capacitor built-in substrate. Moreover, by setting the shape of the electronic component mounted on the capacitor built-in substrate to be sheet-like, the capacitor built-in substrate and the electronic component can be connected in the thickness direction via a through conductor that penetrates each electronic component in the thickness direction. As a result, the active element and the passive element can be configured as a module together.

[0234] 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.

[0235] The following contents are disclosed in this specification.

[0236] <1>

[0237] A capacitor built-in substrate, wherein:

[0238] The capacitor built-in substrate includes:

[0239] capacitor elements; and

[0240] A wiring substrate having the capacitor element built therein,

[0241] 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.

[0242] The capacitor section includes: an anode plate having a porous portion on at least one main surface of a core; a dielectric layer provided on a surface of the porous portion; and a cathode layer provided on a surface of the dielectric layer.

[0243] At least one first capacitor through hole and at least one second capacitor through hole are provided in a manner that does not penetrate the wiring substrate but penetrates the capacitor element in the thickness direction of the anode plate,

[0244] A capacitor through-anode conductor electrically connected to the end surface of the anode plate is provided inside the first capacitor through-hole.

[0245] 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 the thickness direction of the anode plate,

[0246] A substrate-penetrating anode conductor electrically connected to the anode plate is provided on the inner wall surface of the first substrate through-hole.

[0247] A substrate-penetrating cathode conductor electrically connected to the cathode layer is provided on the inner wall surface of the second substrate-penetrating hole.

[0248] The substrate through-anode conductor is located inside the capacitor through-anode conductor.

[0249] <2>

[0250] The capacitor-embedded substrate according to <1>, wherein:

[0251] A capacitor through-cathode conductor which is not electrically connected to the anode plate but is electrically connected to the cathode layer is provided inside the second capacitor through-hole.

[0252] The substrate through-cathode conductor is located inside the capacitor through-cathode conductor.

[0253] <3>

[0254] The capacitor built-in substrate according to <1> or <2>, wherein:

[0255] The substrate through-anode conductor includes a first substrate through-anode conductor.

[0256] The substrate through-cathode conductor includes a first substrate through-cathode conductor and a second substrate through-cathode conductor.

[0257] When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the first substrate through-anode conductor and the second substrate through-cathode conductor.

[0258] <4>

[0259] The capacitor built-in substrate according to <3>, wherein:

[0260] The substrate through-anode conductor further includes a second substrate through-anode conductor.

[0261] When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

[0262] <5>

[0263] The capacitor-embedded substrate according to any one of <1> to <4>, wherein:

[0264] The substrate through-anode conductor includes a first substrate through-anode conductor and a second substrate through-anode conductor.

[0265] The substrate through-cathode conductor includes a first substrate through-cathode conductor.

[0266] When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

[0267] <6>

[0268] The capacitor-embedded substrate according to any one of <1> to <5>, wherein:

[0269] The thickness of the wiring substrate is at least twice the thickness of the capacitor element.

[0270] <7>

[0271] The capacitor-embedded substrate according to any one of <1> to <6>, wherein:

[0272] The sealing insulating layer constituting the wiring substrate includes glass cloth.

[0273] Description of Reference Numerals

[0274] 1, 1a, 2, 3, 4, 5, capacitor built-in substrate; 10, capacitor part; 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 shielding layer; 30A, capacitor through-anode conductor; 30B, capacitor through-cathode conductor; 35A, first capacitor through-hole; 35B, second capacitor through-hole; 40A, substrate through-anode conductor; 40A1, first substrate through-anode conductor; 40A2, second substrate through-anode conductor ; 40B, substrate through cathode conductor; 40B1, first substrate through cathode conductor; 40B2, second substrate through cathode conductor; 45A, first substrate through hole; 45B, second substrate through hole; 48A, first resin filling portion; 48B, second resin filling portion; 50, sealing insulating layer; 51A, 51B, first wiring layer; 52A, 52B, second wiring layer; 53A, 53B, third wiring layer; 55A, anode path conductor; 55B, cathode path conductor; 60, glass cloth; 100, 100a, capacitor element; 200, wiring substrate; T 1 , the thickness of the capacitor element; T 2 , the thickness of the wiring substrate; T 3 , the thickness of the sealing insulating layer; α, the center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor; β, the center-to-center distance between the first substrate through-anode conductor and the second substrate through-cathode conductor; γ, the center-to-center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

Claims

1. A capacitor built-in substrate, wherein: The capacitor built-in substrate includes: capacitor elements; and a wiring substrate having the capacitor element built therein, 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; 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 in a manner that does not penetrate the wiring substrate in the thickness direction of the anode plate but penetrates the capacitor element, A capacitor through-anode conductor electrically connected to the end surface 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 substrate and the capacitor element in the thickness direction of the anode plate, A substrate-penetrating anode conductor electrically connected to the anode plate is provided on the inner wall surface of the first substrate through-hole. A substrate-penetrating cathode conductor electrically connected to the cathode layer is provided on the inner wall surface of the second substrate through-hole. The substrate through-anode conductor is located inside the capacitor through-anode conductor.

2. The capacitor built-in substrate according to claim 1, wherein: A capacitor through-cathode conductor which is not electrically connected to the anode plate but is electrically connected to the cathode layer is provided inside the second capacitor through-hole. The substrate through-cathode conductor is located inside the capacitor through-cathode conductor.

3. The built-in capacitor substrate according to claim 1 or 2, wherein: The substrate through-anode conductor includes a first substrate through-anode conductor, The substrate through-cathode conductor includes a first substrate through-cathode conductor and a second substrate through-cathode conductor. When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the first substrate through-anode conductor and the second substrate through-cathode conductor.

4. The capacitor built-in substrate according to claim 3, wherein: The substrate through-anode conductor further includes a second substrate through-anode conductor, When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

5. The built-in capacitor substrate according to any one of claims 1 to 4, wherein The substrate through-anode conductor includes a first substrate through-anode conductor and a second substrate through-anode conductor. The substrate through-cathode conductor includes a first substrate through-cathode conductor, When viewed in plan from the thickness direction of the anode plate, a center-to-center distance between the first substrate through-anode conductor and the first substrate through-cathode conductor is equal to a center-to-center distance between the second substrate through-anode conductor and the first substrate through-cathode conductor.

6. The built-in capacitor substrate according to any one of claims 1 to 5, wherein: The thickness of the wiring substrate is at least twice the thickness of the capacitor element.

7. The built-in capacitor substrate according to any one of claims 1 to 6, wherein: The sealing insulating layer constituting the wiring substrate includes glass cloth.

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