Substrate with built-in capacitor

Abstract

This substrate with a built-in capacitor 1 comprises: a core substrate 100 provided with an opening 130 in a thickness direction T; a capacitor component 200 provided inside the opening 130 of the core substrate 100; and a sealing material 300 that seals the core substrate 100 and the capacitor component 200. The core substrate 100 has a base 110 provided with the opening 130. The capacitor component 200 has: a capacitor body 210 having an anode layer 220 that has a core 221, a dielectric layer 230, and a cathode layer 240 facing the anode layer 220 with the dielectric layer 230 interposed in the thickness direction T; through conductors 260A (260B) provided on at least the inner wall surface of through holes 261A (261B) penetrating at least the capacitor body 210 in the thickness direction T; and conductor wiring layers 270A (270B) provided on both ends of the through conductors 260A (260B) facing each other in the thickness direction T. The sealing material 300 has: a first sealing part 310 that covers one surface of each of the core substrate 100 and the capacitor component 200 in the thickness direction T; and a second sealing part 320 that covers the other surface of each of the core substrate 100 and the capacitor component 200. In the thickness direction T, the distances T1a (T1b) from surfaces P1a (P1b) on the first sealing part 310 side of conductor wiring layers 270A (270B) to a surface Q1 on the first sealing part 310 side of the sealing material 300 are greater than distances T2a (T2b) from surfaces P2a (P2b) on the second sealing part 320 side of the conductor wiring layers 270A (270B) to a surface Q2 on the second sealing part 320 side of the sealing material 300, and diameters R1a (R1b) of the end parts on the first sealing part 310 side of through holes 261A (261B) are larger than diameters R2a (R2b) of the end parts on the second sealing part 320 side of the through holes 261A (261B).

Description

Capacitor built-in board

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

[0002] Patent Document 1 discloses a wiring board comprising a core substrate made of an insulating material, and a first insulating layer laminated on a first main surface side of the core substrate and a second main surface side opposite the first main surface, wherein a cavity is formed in the core substrate in which a via conductor structure is disposed, the via conductor structure having a second substrate and a first through-hole conductor formed to penetrate the second substrate, and wherein second through-hole conductors penetrating the core substrate and the first insulating layer are formed in areas of the core substrate other than the cavity, and wherein the wiring density of the first through-hole conductors is greater than the wiring density of the second through-hole conductors.

[0003] JP 2014-165218 A

[0004] In the wiring board shown in Figure 1B of Patent Document 1, a via conductor structure having a second substrate and a first through-hole conductor is provided in a cavity of a core substrate and sealed with an insulating layer. While the wiring board shown in Figure 1B of Patent Document 1 shows the insulating layers on both ends of the first through-hole conductor facing each other in the thickness direction as being approximately equal in thickness, it is also possible that the thickness of the insulating layer on one end of the first through-hole conductor is greater than the thickness of the insulating layer on the other end of the first through-hole conductor. In this case, the greater thickness of the insulating layer on one end of the first through-hole conductor increases the stress applied from the insulating layer to the one end of the first through-hole conductor, which may result in damage to the conductor portion of the first through-hole conductor, particularly the conductor portion located at one end of the first through-hole conductor.

[0005] In response to this, in the wiring board described in, for example, FIG. 1B of Patent Document 1, it is conceivable to disperse the stress applied to the first through-hole conductor from the insulating layer by increasing the diameter of the first through-hole conductor. However, in the via conductor structure included in the wiring board described in, for example, FIG. 1B of Patent Document 1, if the diameter of the first through-hole conductor is increased overall, the area of ​​the second substrate will be reduced overall. In this case, if the via conductor structure is a capacitor component, the area of ​​the portion of the second substrate that can exhibit capacitance will be reduced overall, which may result in a decrease in the capacitance of the capacitor component.

[0006] The present invention has been made to solve the above problems, and aims to provide a capacitor-embedded substrate that can suppress both damage to the through conductor and the conductor wiring layer provided on its end, and a decrease in capacitance.

[0007] The capacitor-embedded substrate of the present invention includes a core substrate having an opening in a thickness direction, a capacitor component provided in the opening of the core substrate, and a sealing material that seals the core substrate and the capacitor component, wherein the core substrate has a base material having the opening, and the capacitor component includes a capacitor body having an anode layer having a core, a dielectric layer, and a cathode layer facing the anode layer in the thickness direction with the dielectric layer interposed therebetween, a through conductor provided on at least an inner wall surface of a through hole that penetrates at least the capacitor body in the thickness direction, and a sealing material that seals the capacitor component on both ends of the through conductor that face each other in the thickness direction. the sealing material has, in the thickness direction, a first sealing portion covering one surface of each of the core substrate and the capacitor components, and a second sealing portion covering the other surface of each of the core substrate and the capacitor components, the distance in the thickness direction from the surface of the conductor wiring layer on the first sealing portion side to the surface of the sealing material on the first sealing portion side is larger than the distance from the surface of the conductor wiring layer on the second sealing portion side to the surface of the sealing material on the second sealing portion side, and the diameter of the end of the through hole on the first sealing portion side is larger than the diameter of the end of the through hole on the second sealing portion side.

[0008] According to the present invention, it is possible to provide a capacitor-embedded substrate that can suppress both damage to the through conductors and the conductive wiring layers provided on the ends of the through conductors and a decrease in capacitance.

[0009] Fig. 1 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to embodiment 1 of the present invention. Fig. 2 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to embodiment 2 of the present invention. Fig. 3 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to a modified example of embodiment 2 of the present invention. Fig. 4 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to embodiment 3 of the present invention. Fig. 5 is a cross-sectional view schematically showing an example of a capacitor-embedded substrate according to embodiment 4 of the present invention.

[0010] The capacitor-embedded substrate of the present invention will be described below. Note that the present invention is not limited to the following configuration and may be modified as appropriate without departing from the spirit of the present invention. Furthermore, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0011] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From embodiment 2 onwards, descriptions of matters common to embodiment 1 will be omitted, and differences will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned one after the other for each embodiment.

[0012] In the following description, when 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."

[0013] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0014] In this specification, unless otherwise specified, terms indicating the relationship between elements (e.g., "vertical," "parallel," etc.) and terms indicating the shape of elements not only mean the literal strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0015] The capacitor-embedded substrate of the present invention includes a core substrate having an opening in a thickness direction, a capacitor component provided in the opening of the core substrate, and a sealing material that seals the core substrate and the capacitor component, wherein the core substrate has a base material having the opening, and the capacitor component includes a capacitor body having an anode layer having a core, a dielectric layer, and a cathode layer facing the anode layer in the thickness direction with the dielectric layer interposed therebetween, a through conductor provided on at least an inner wall surface of a through hole that penetrates at least the capacitor body in the thickness direction, and a sealing material that seals the capacitor component on both ends of the through conductor that face each other in the thickness direction. the sealing material has, in the thickness direction, a first sealing portion covering one surface of each of the core substrate and the capacitor components, and a second sealing portion covering the other surface of each of the core substrate and the capacitor components, the distance in the thickness direction from the surface of the conductor wiring layer on the first sealing portion side to the surface of the sealing material on the first sealing portion side is larger than the distance from the surface of the conductor wiring layer on the second sealing portion side to the surface of the sealing material on the second sealing portion side, and the diameter of the end of the through hole on the first sealing portion side is larger than the diameter of the end of the through hole on the second sealing portion side.

[0016] First Embodiment FIG. 1 is a schematic cross-sectional view showing an example of a capacitor-embedded substrate according to a first embodiment of the present invention.

[0017] The capacitor-embedded substrate 1 shown in FIG. 1 includes a core substrate 100 , a capacitor component 200 , and a sealing material 300 .

[0018] The core substrate 100 has a base material 110. In the example shown in FIG.

[0019] The base material 110 has an opening (also called a cavity) 130 formed in the thickness direction T. That is, the core substrate 100 has the opening 130. In the example shown in Fig. 1 , the opening 130 penetrates the core substrate 100, specifically the base material 110, in the thickness direction T.

[0020] The number of openings 130 provided in the core substrate 100 may be one or more.

[0021] The substrate 110 is preferably made of an insulating material, that is, the substrate 110 is preferably an insulating substrate.

[0022] The insulating material constituting the base material 110 may contain insulating resin, prepreg, inorganic material, a mixture thereof, or the like.

[0023] Examples of insulating resins contained in the insulating material constituting the substrate 110 include epoxy resins, polyester resins, bismaleimide triazine resins, polyimide resins, phenolic resins, and allylated phenylene ether resins.

[0024] Examples of prepregs contained in the insulating material that constitutes the base material 110 include resin-impregnated glass fibers (resin-impregnated glass cloth).

[0025] With regard to the prepreg contained in the insulating material that constitutes the base material 110, the diameter of the glass fiber (glass cloth) in the prepreg is preferably 3 μm or more and 15 μm or less.

[0026] With respect to the prepreg contained in the insulating material constituting the base material 110, the resin content in the prepreg is preferably 50% by weight or more and 90% by weight or less.

[0027] Examples of inorganic materials contained in the insulating material that constitutes the base material 110 include glass.

[0028] The thickness of the core substrate 100 is preferably greater than the thickness of the capacitor component 200 .

[0029] The capacitor component 200 is provided in the opening 130 of the core substrate 100 .

[0030] In addition, when multiple openings 130 are provided in the core substrate 100, a capacitor component 200 may be provided in each opening 130, or capacitor components 200 may be provided in some of the openings 130 while electronic components different from the capacitor components 200 are provided in the remaining openings 130.

[0031] The capacitor component 200 includes a capacitor body 210, a through conductor 260A, a through conductor 260B, a conductor wiring layer 270A, and a conductor wiring layer 270B.

[0032] The capacitor body 210 includes an anode layer 220 , a dielectric layer 230 , and a cathode layer 240 .

[0033] The following describes an example in which the capacitor body 210 constitutes an electrolytic capacitor. However, the capacitor body 210 may constitute a capacitor other than an electrolytic capacitor.

[0034] The anode layer 220 has a core portion 221 and a porous portion 222 .

[0035] In this specification, the core of the anode layer means a portion that is substantially free of pores such as a porous portion, and preferably constitutes the central portion in the thickness direction of the anode layer.

[0036] The core 221 is preferably made of a metal, and more preferably made of a valve metal. When the core 221 is made of a valve metal, the anode layer 220 is also called a valve metal substrate.

[0037] Examples of valve metals constituting the core 221 include simple metals such as aluminum, tantalum, niobium, titanium, and zirconium, and alloys containing at least one of these simple metals. Among these, aluminum or an aluminum alloy is preferred.

[0038] The porous portion 222 is provided on at least one of both surfaces of the core portion 221 that face each other in the thickness direction T. In other words, the porous portion 222 may be provided on only one surface of the core portion 221, or on both surfaces of the core portion 221. In this way, the anode layer 220 has the porous portion 222 on at least one of both surfaces that face each other in the thickness direction T. This increases the surface area of ​​the anode layer 220, which makes it easier to improve the capacitance of the capacitor body 210.

[0039] The porous portion 222 is preferably an etching layer formed by etching the surface of the anode layer 220 (core portion 221).

[0040] The anode layer 220 is preferably in the form of a flat plate (anode plate), and more preferably in the form of a foil (anode foil).

[0041] In this specification, the term "plate-like" includes foil-like, sheet-like, film-like, etc., and these are not distinguished by the dimension in the thickness direction.

[0042] The dielectric layer 230 is provided on the surface of the porous portion 222. Specifically, the dielectric layer 230 is provided along the surface (outline) of each pore present in the porous portion 222.

[0043] The dielectric layer 230 is preferably made of an oxide film of the valve metal described above. For example, when the anode layer 220 is an aluminum foil, the oxide film that becomes the dielectric layer 230 is formed by anodizing the aluminum foil in an aqueous solution containing ammonium adipate or the like (also called chemical conversion treatment). Since the dielectric layer 230 is formed along the surface of the porous portion 222, pores (recesses) are provided in the dielectric layer 230.

[0044] The cathode layer 240 faces the anode layer 220 in the thickness direction T with the dielectric layer 230 interposed therebetween.

[0045] The cathode layer 240 is provided on the surface of the dielectric layer 230 .

[0046] Cathode layer 240 preferably has a solid electrolyte layer 241 provided on the surface of dielectric layer 230, and a conductor layer 242 provided on the surface of solid electrolyte layer 241. When cathode layer 240 has solid electrolyte layer 241, capacitor body 210 constitutes a solid electrolytic capacitor.

[0047] Solid electrolyte layer 241 preferably has an inner layer provided inside the pores of dielectric layer 230 and an outer layer covering the inner layer.

[0048] Examples of materials constituting the solid electrolyte layer 241 include conductive polymers such as polypyrroles, polythiophenes, and polyanilines. Among these, polythiophenes are preferred, and poly(3,4-ethylenedioxythiophene) (PEDOT) is particularly preferred. The conductive polymer may also contain a dopant such as polystyrene sulfonate (PSS).

[0049] The solid electrolyte layer 241 is formed in a predetermined region on the surface of the dielectric layer 230 by, for example, a method of applying a dispersion liquid of a conductive polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer 230 and drying it, or a method of forming a polymerized film of poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer 230 using a treatment liquid containing a polymerizable monomer such as 3,4-ethylenedioxythiophene.

[0050] The conductor layer 242 preferably has a conductive resin layer 243 provided on the surface of the solid electrolyte layer 241 and a metal layer 244 provided on the surface of the conductive resin layer 243 .

[0051] The conductive resin layer 243 may be, for example, a conductive adhesive layer containing at least one conductive filler selected from the group consisting of copper filler, silver filler, nickel filler, and carbon filler.

[0052] The metal layer 244 preferably contains a metal filler.

[0053] The metal filler contained in the metal layer 244 is preferably at least one selected from the group consisting of a copper filler, a silver filler, and a nickel filler.

[0054] The metal layer 244 may be, for example, a metal plating film, a metal foil, etc. In this case, the metal layer 244 is preferably made of at least one metal selected from the group consisting of copper, silver, nickel, and alloys containing at least one of these metals as a main component.

[0055] In this specification, the term "major component" means the element component that occupies the largest weight ratio.

[0056] The conductive layer 242 may have, for example, a carbon layer as the conductive resin layer 243 and a copper layer as the metal layer 244 .

[0057] The carbon layer is formed in a predetermined region by, for example, applying a carbon paste containing a carbon filler to the surface of the solid electrolyte layer 241 by a sponge transfer method, a screen printing method, a dispenser coating method, an inkjet printing method, or the like.

[0058] The copper layer is formed in a predetermined region by applying a copper paste containing a copper filler to the surface of the carbon layer by a sponge transfer method, a screen printing method, a spray coating method, a dispenser coating method, an inkjet printing method, or the like.

[0059] The conductor layer 242 may have at least one of a conductive resin layer 243 and a metal layer 244. That is, the conductor layer 242 may have only the conductive resin layer 243, only the metal layer 244, or both the conductive resin layer 243 and the metal layer 244.

[0060] The capacitor body 210 preferably further includes a mask layer 250 provided on the periphery of the porous portion 222 when viewed in the thickness direction T.

[0061] The mask layer 250 is preferably provided on the entire periphery of the porous portion 222 when viewed from the thickness direction T. The mask layer 250 may also be provided on a part of the periphery of the porous portion 222 when viewed from the thickness direction T.

[0062] The mask layer 250 is preferably provided so as to extend inward from at least one of both surfaces of the anode layer 220 in the thickness direction T, and more preferably so as to extend inward from both surfaces of the anode layer 220.

[0063] The mask layer 250 may or may not be in contact with the core portion 221 in the thickness direction T.

[0064] The mask layer 250 may be provided not only inside the porous portion 222 but also outside the porous portion 222. In this case, the mask layer 250 may be provided on the surface of the filled porous portion 222 while filling the inside of the porous portion 222. In other words, the thickness of the mask layer 250 may be greater than the thickness of the porous portion 222.

[0065] When the mask layer 250 is provided outside the porous portion 222, it is preferable that the mask layer 250 be provided in a region surrounding the cathode layer 240 when viewed in the thickness direction T.

[0066] When viewed from the thickness direction T, the mask layer 250 may be partially overlapped with the cathode layer 240 , or may not be entirely overlapped with the cathode layer 240 .

[0067] The mask layer 250 is preferably made of an insulating material, which ensures sufficient insulation between the anode layer 220 and the cathode layer 240 and effectively prevents short circuits between them.

[0068] Examples of insulating materials that can be used to form the mask layer 250 include polyphenylsulfone (PPS), polyethersulfone (PES), cyanate ester resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition consisting of soluble polyimide siloxane and epoxy resin, polyimide resin, polyamide-imide resin, derivatives or precursors of these, etc.

[0069] The mask layer 250 is formed on the periphery of the porous portion 222, for example, by applying the above-mentioned insulating material to a position on both surfaces of the anode layer 220 that overlaps the periphery of the porous portion 222, and allowing the material to penetrate from both surfaces of the anode layer 220 toward the inside.

[0070] The mask layer 250 may be formed on the porous portion 222 either before or after the dielectric layer 230 is formed.

[0071] The planar shape of the capacitor body 210 when viewed from the thickness direction T may be, for example, a rectangle (square or oblong), a quadrangle other than a rectangle, a polygon such as a triangle, a pentagon, or a hexagon, a circle, or an ellipse.

[0072] The number of capacitor bodies 210 in the capacitor component 200 may be one or more.

[0073] When the capacitor component 200 includes a plurality of capacitor bodies 210, the plurality of capacitor bodies 210 are preferably arranged in a plane in a plane direction perpendicular to the thickness direction T. In the example shown in Fig. 1 , the plane direction is a direction that includes a first direction U perpendicular to the thickness direction T and a second direction V perpendicular to the thickness direction T and the first direction U.

[0074] When the plurality of capacitor bodies 210 are arranged in a plane in the planar direction, the plurality of capacitor bodies 210 may be arranged in a plane along a plurality of directions among the planar directions, or along a single direction. Furthermore, the plurality of capacitor bodies 210 may be arranged in a regular or irregular manner.

[0075] As described above, when the capacitor component 200 includes a plurality of capacitor bodies 210, the capacitor component 200 may form a capacitor array in which the plurality of capacitor bodies 210 are arranged in an array in the planar direction.

[0076] The through conductor 260A is provided on at least the inner wall surface of a through hole 261A that penetrates at least the capacitor body 210 in the thickness direction T. In the example shown in Fig. 1 , the through hole 261A penetrates the capacitor body 210 and a sealing layer 290 (described later) in the thickness direction T. In the example shown in Fig. 1 , the through conductor 260A is provided on the inner wall surface of the through hole 261A.

[0077] The through conductor 260A may be provided only on the inner wall surface of the through hole 261A, or may be provided throughout the entire interior of the through hole 261A.

[0078] When the through conductor 260A is provided only on the inner wall surface of the through hole 261A, the space surrounded by the through conductor 260A in the through hole 261A may be filled with a resin material. That is, the capacitor component 200 may further include a resin filling portion 280A provided in the space surrounded by the through conductor 260A in the through hole 261A. When the space in the through hole 261A is eliminated by providing the resin filling portion 280A, the occurrence of delamination of the through conductor 260A is suppressed.

[0079] The thermal expansion coefficient of the resin filling portion 280A is preferably higher than that of the through conductor 260A. Specifically, the thermal expansion coefficient of the constituent material (resin material) of the resin filling portion 280A is preferably higher than that of the constituent material of the through conductor 260A. In this case, the resin filling portion 280A (specifically, the constituent material (resin material) of the resin filling portion 280A) expands in a high-temperature environment, and the through conductor 260A is pressed against the inner wall surface of the through hole 261A from the inside to the outside of the through hole 261A, thereby sufficiently suppressing the occurrence of delamination of the through conductor 260A.

[0080] The thermal expansion coefficient of the resin filling portion 280A may be the same as that of the through conductor 260A, or may be lower than that of the through conductor 260A.

[0081] It is noted that the capacitor component 200 does not necessarily have to have the resin filling portion 280A. In this case, the through conductor 260A is preferably provided in the entire interior of the through hole 261A.

[0082] The via conductor 260A is preferably electrically connected to the anode layer 220.

[0083] It is preferable that the through conductor 260A is electrically connected to the end surface of the anode layer 220 that faces the inner wall surface of the through hole 261A in the planar direction. In the example shown in FIG. 1 , the through conductor 260A is directly connected to the end surface of the anode layer 220.

[0084] It is preferable that the core portion 221 and the porous portion 222 are exposed at the end face of the anode layer 220 that is electrically connected to the through conductor 260A. In this case, the porous portion 222 as well as the core portion 221 are electrically connected to the through conductor 260A.

[0085] When viewed from the thickness direction T, the through conductor 260A is preferably electrically connected to the anode layer 220 over the entire periphery of the through hole 261A. In this case, the connection resistance between the anode layer 220 and the through conductor 260A is likely to decrease, and therefore the equivalent series resistance (ESR) of the capacitor component 200 is likely to decrease.

[0086] The through conductor 260A may be electrically connected to the anode layer 220 via an anode connection layer. In this case, the anode connection layer is preferably provided between the anode layer 220 and the through conductor 260A in the planar direction. In this case, the anode connection layer functions as a barrier layer for the anode layer 220, specifically, as a barrier layer for the core portion 221 and the porous portion 222. When the anode connection layer functions as a barrier layer for the anode layer 220, dissolution of the anode layer 220 that occurs during chemical treatment to form the conductor wiring layer 270A or the like is suppressed, and thus penetration of the chemical solution into the capacitor body 210 is suppressed, which tends to improve the reliability of the capacitor component 200.

[0087] Examples of materials that can be used to form the through conductors 260A include metal materials containing low-resistance metals such as copper, gold, and silver, and composite materials of the above metals and resin.

[0088] Examples of the planar shape of the through-hole 261A when viewed from the thickness direction T include a circle, an ellipse, and a rectangle (square or oblong).

[0089] The through conductor 260A is formed, for example, as follows. First, a through hole 261A is formed by performing laser processing or the like, penetrating at least the capacitor body 210 in the thickness direction T. Then, the inner wall surface of the through hole 261A is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver, thereby forming the through conductor 260A. When forming the through conductor 260A, for example, metallizing the inner wall surface of the through hole 261A with an electroless copper plating process, an electrolytic copper plating process, or the like can facilitate processing. Note that the method of forming the through conductor 260A may include filling the through hole 261A with a metal material, a composite material of metal and resin, or the like, in addition to the method of metallizing the inner wall surface of the through hole 261A.

[0090] The through conductor 260B is provided at a position electrically insulated from the through conductor 260A, at least on the inner wall surface of a through hole 261B that penetrates at least the capacitor body 210 in the thickness direction T. In the example shown in Fig. 1 , the through hole 261B penetrates the capacitor body 210 and a sealing layer 290 (described later) in the thickness direction T, at a position spaced apart from the through hole 261A. In the example shown in Fig. 1 , the through conductor 260B is provided on the inner wall surface of the through hole 261B.

[0091] The through conductor 260B may be provided only on the inner wall surface of the through hole 261B, or may be provided throughout the entire interior of the through hole 261B.

[0092] When the through conductor 260B is provided only on the inner wall surface of the through hole 261B, the space surrounded by the through conductor 260B in the through hole 261B may be filled with a resin material. That is, the capacitor component 200 may further include a resin filling portion 280B provided in the space surrounded by the through conductor 260B in the through hole 261B. When the space in the through hole 261B is eliminated by providing the resin filling portion 280B, the occurrence of delamination of the through conductor 260B is suppressed.

[0093] The thermal expansion coefficient of the resin filling portion 280B is preferably higher than that of the through conductor 260B. Specifically, the thermal expansion coefficient of the constituent material (resin material) of the resin filling portion 280B is preferably higher than that of the constituent material of the through conductor 260B. In this case, the resin filling portion 280B (specifically, the constituent material (resin material) of the resin filling portion 280B) expands in a high-temperature environment, and the through conductor 260B is pressed against the inner wall surface of the through hole 261B from the inside to the outside of the through hole 261B, thereby sufficiently suppressing the occurrence of delamination of the through conductor 260B.

[0094] The thermal expansion coefficient of the resin filling portion 280B may be the same as that of the through conductor 260B, or may be lower than that of the through conductor 260B.

[0095] It is noted that the capacitor component 200 does not necessarily have to have the resin filling portion 280B. In this case, the through conductor 260B is preferably provided in the entire interior of the through hole 261B.

[0096] The through conductor 260B is preferably electrically connected to the cathode layer 240. In the example shown in Fig. 1, the through conductor 260B is electrically connected to the cathode layer 240 via the conductor wiring layer 270B and a via conductor 285 described later.

[0097] It is preferable that an insulating material such as a sealing layer 290 (described later) be filled between the capacitor body 210 and the through conductor 260B in the planar direction, and further between the anode layer 220 and the through conductor 260B in the planar direction. In this case, insulation between the anode layer 220 and the through conductor 260B, and further between the anode layer 220 and the cathode layer 240, is ensured, and short-circuiting between them is prevented.

[0098] Examples of materials constituting the through conductors 260B include metal materials containing low-resistance metals such as copper, gold, and silver, and composite materials of the above metals and resin.

[0099] The constituent materials of the through conductor 260A and the through conductor 260B may be the same as or different from each other.

[0100] The planar shape of the through-hole 261B when viewed from the thickness direction T may be, for example, a circle, an ellipse, a rectangle (square or oblong), or the like.

[0101] The planar shapes of the through-hole 261A and the through-hole 261B may be the same as each other or may be different from each other.

[0102] The through conductor 260B is formed, for example, as follows. First, a through hole penetrating the capacitor body 210 in the thickness direction T is formed by laser processing or the like. Next, the capacitor body 210 is sealed using an insulating material or the like to form a sealing layer (e.g., the sealing layer 290 described later) that fills at least the through hole. Then, the sealing layer is formed by laser processing or the like to the sealing layer. At this time, the diameter of the through hole 261B is made smaller than the diameter of the previously formed through hole, so that the sealing layer is provided between the inner wall surface of the previously formed through hole and the inner wall surface of the through hole 261B in the planar direction. Then, the inner wall surface of the through hole 261B is metallized with a metal material containing a low-resistance metal such as copper, gold, or silver to form the through conductor 260B. When forming the through conductor 260B, for example, metallizing the inner wall surface of the through hole 261B by electroless copper plating, electrolytic copper plating, or the like can facilitate processing. As a method for forming the through conductor 260B, in addition to a method of metallizing the inner wall surface of the through hole 261B, a method of filling the through hole 261B with a metal material, a composite material of metal and resin, or the like may be used.

[0103] The conductor wiring layer 270A is provided on both ends of the through conductor 260A that face each other in the thickness direction T.

[0104] The conductor wiring layer 270A is electrically connected to the through conductor 260A and functions as a connection terminal of the capacitor component 200. In the example shown in Fig. 1 , the conductor wiring layer 270A is electrically connected to the anode layer 220 via the through conductor 260A and functions as a connection terminal for the anode layer 220.

[0105] Examples of materials constituting the conductor wiring layer 270A include metal materials containing low-resistance metals such as copper, gold, silver, etc. In this case, the conductor wiring layer 270A is formed by, for example, plating both ends of the through conductor 260A.

[0106] In order to improve the adhesion between the conductor wiring layer 270A and other components, in this case, the adhesion between the conductor wiring layer 270A and the through conductor 260A, a mixed material of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as the constituent material of the conductor wiring layer 270A.

[0107] The conductor wiring layer 270B is provided on both ends of the through conductor 260B that face each other in the thickness direction T at a position electrically insulated from the conductor wiring layer 270A.

[0108] The conductor wiring layer 270B is electrically connected to the through conductor 260B and functions as a connection terminal of the capacitor component 200. In the example shown in Fig. 1 , the conductor wiring layer 270B is electrically connected to the cathode layer 240 through a via conductor 285 (described later) and functions as a connection terminal for the cathode layer 240.

[0109] Examples of materials constituting the conductor wiring layer 270B include metal materials containing low-resistance metals such as copper, gold, silver, etc. In this case, the conductor wiring layer 270B is formed by, for example, plating both ends of the through conductor 260B.

[0110] In order to improve the adhesion between the conductor wiring layer 270B and other components, in this case, the adhesion between the conductor wiring layer 270B and the through conductor 260B, a mixed material of at least one conductive filler selected from the group consisting of silver filler, copper filler, nickel filler, and carbon filler and resin may be used as the constituent material of the conductor wiring layer 270B.

[0111] The conductor wiring layer 270A and the conductor wiring layer 270B may be made of the same material or different materials.

[0112] The capacitor component 200 preferably further includes a sealing layer 290 that seals the capacitor body 210. In this case, the capacitor body 210 is protected by the sealing layer 290.

[0113] The sealing layer 290 preferably covers at least one of both surfaces of the capacitor body 210 that face each other in the thickness direction T, and more preferably covers both surfaces of the capacitor body 210. In the example shown in FIG. 1 , the sealing layer 290 covers the cathode layer 240 and the mask layer 250 that constitute both surfaces of the capacitor body 210.

[0114] When viewed in the thickness direction T, the sealing layer 290 preferably overlaps the entire capacitor body 210 .

[0115] The sealing layer 290 may penetrate the capacitor body 210 in the thickness direction T. In the example shown in FIG. 1 , the sealing layer 290 penetrates the anode layer 220, the dielectric layer 230, and the mask layer 250 in the thickness direction T.

[0116] The sealing layer 290 is preferably provided between the capacitor body 210 and the through conductor 260B in the planar direction, and further between the anode layer 220 and the through conductor 260B in the planar direction.

[0117] It is preferable that sealing layer 290 contacts both capacitor body 210 and through conductor 260B, and therefore both anode layer 220 and through conductor 260B, in the planar direction. In this case, core portion 221 and porous portion 222 are preferably exposed on the end surface of anode layer 220 that contacts sealing layer 290. This increases the contact area between porous portion 222 and sealing layer 290, improving adhesion between them and making it less likely that problems such as peeling will occur between porous portion 222 and sealing layer 290.

[0118] When the core portion 221 and the porous portion 222 are exposed on the end surface of the anode layer 220 that contacts the sealing layer 290, it is preferable that the mask layer 250 be provided around the through conductor 260B, with the constituent material of the mask layer 250 penetrating the pores of the porous portion 222 and thereby spreading inside the porous portion 222. In this case, insulation between the anode layer 220 and the through conductor 260B, and therefore insulation between the anode layer 220 and the cathode layer 240, is sufficiently ensured, and short-circuiting between them is sufficiently prevented.

[0119] When the core portion 221 and the porous portion 222 are exposed on the end surface of the anode layer 220 that contacts the sealing layer 290, it is preferable that the constituent material of the sealing layer 290 penetrates into the pores of the porous portion 222. In this case, the mechanical strength of the porous portion 222 is improved, and the occurrence of delamination due to the pores of the porous portion 222 is suppressed.

[0120] The thermal expansion coefficient of the sealing layer 290 is preferably higher than that of the through conductors 260B. Specifically, the thermal expansion coefficient of the constituent material of the sealing layer 290 is preferably higher than that of the constituent material of the through conductors 260B. In this case, the sealing layer 290 (specifically, the constituent material of the sealing layer 290) expands in a high-temperature environment, thereby pressing down on the porous portion 222 and the through conductors 260B, thereby sufficiently suppressing the occurrence of delamination.

[0121] The thermal expansion coefficient of the sealing layer 290 may be the same as or lower than the thermal expansion coefficient of the through conductors 260B.

[0122] When the capacitor component 200 includes a plurality of capacitor bodies 210, the sealing layer 290 may be filled between adjacent capacitor bodies 210 so as to separate the plurality of capacitor bodies 210 from each other.

[0123] As described above, it is preferable that sealing layer 290 be provided so as to conform to the surface shape of capacitor body 210 .

[0124] The through hole 261A preferably penetrates not only the capacitor body 210 but also the sealing layer 290 in the thickness direction T. In the example shown in FIG.

[0125] The through hole 261B preferably penetrates not only the capacitor body 210 but also the sealing layer 290 in the thickness direction T. In the example shown in FIG.

[0126] The conductor wiring layer 270A is preferably provided on both ends of the through conductor 260A, as well as on both surfaces of the sealing layer 290 that face each other in the thickness direction T. In the example shown in FIG. 1 , the conductor wiring layer 270A is provided from both ends of the through conductor 260A to both surfaces of the sealing layer 290. Specifically, the conductor wiring layer 270A is provided from one end of the through conductor 260A (the upper end in FIG. 1 ) to one surface of the sealing layer 290 (the upper surface in FIG. 1 ), and is provided from the other end of the through conductor 260A (the lower end in FIG. 1 ) to the other surface of the sealing layer 290 (the lower surface in FIG. 1 ).

[0127] The conductor wiring layer 270B is preferably provided on both ends of the through conductor 260B, as well as on both surfaces of the sealing layer 290 that face each other in the thickness direction T. In the example shown in FIG. 1 , the conductor wiring layer 270B is provided from both ends of the through conductor 260B to both surfaces of the sealing layer 290. Specifically, the conductor wiring layer 270B is provided from one end of the through conductor 260B (the upper end in FIG. 1 ) to one surface of the sealing layer 290 (the upper surface in FIG. 1 ), and is provided from the other end of the through conductor 260B (the lower end in FIG. 1 ) to the other surface of the sealing layer 290 (the lower surface in FIG. 1 ).

[0128] The sealing layer 290 is preferably made of an insulating material.

[0129] The insulating material that forms the sealing layer 290 may contain an insulating resin.

[0130] Examples of insulating resins contained in the insulating material that forms the sealing layer 290 include epoxy resins, phenolic resins, and polyimide resins.

[0131] The insulating material that forms the sealing layer 290 may contain a filler.

[0132] Examples of the filler contained in the insulating material that constitutes the sealing layer 290 include inorganic fillers such as silica filler and alumina filler.

[0133] The sealing layer 290 may be made up of only one layer, or may be made up of multiple layers.

[0134] When the sealing layer 290 is made up of multiple layers, the constituent materials of the multiple layers may be the same as each other, may be different from each other, or may be partially different from each other.

[0135] Sealing layer 290 is formed so as to seal capacitor body 210 by, for example, a method of thermocompressing an insulating resin sheet, or a method of applying an insulating resin paste and then thermally curing it.

[0136] The capacitor component 200 preferably further includes a via conductor 285 that penetrates the sealing layer 290 in the thickness direction T and is connected to the cathode layer 240 and the conductor wiring layer 270B.

[0137] Examples of materials that can be used to form the via conductors 285 include metal materials containing low-resistance metals such as copper, gold, and silver.

[0138] The via conductor 285 is formed, for example, by plating the inner wall surface of a through hole that penetrates the sealing layer 290 in the thickness direction T with the above-mentioned metal material, or by filling it with a conductive paste and then performing a heat treatment.

[0139] The sealing material 300 seals the core substrate 100 and the capacitor component 200 .

[0140] The sealing material 300 has, in the thickness direction T, a first sealing portion 310 and a second sealing portion 320 .

[0141] The first sealing portion 310 covers one surface (the upper surface in FIG. 1 ) of each of the core substrate 100 and the capacitor component 200 in the thickness direction T.

[0142] The second sealing portion 320 covers the other surfaces (lower surfaces in FIG. 1 ) of the core substrate 100 and the capacitor component 200 in the thickness direction T.

[0143] The sealing material 300 is preferably provided between the core substrate 100 and the capacitor component 200 in the planar direction.

[0144] The sealing material 300 may be integrated with the sealing layer 290 so that there is no interface between them, or may not be integrated with the sealing layer 290 so that there is an interface between them.

[0145] The sealing material 300 is preferably made of an insulating material.

[0146] The insulating material constituting the sealing material 300 may contain insulating resin, prepreg, inorganic material, a mixture thereof, or the like.

[0147] Examples of insulating resins contained in the insulating material constituting the sealing material 300 include epoxy resins, phenolic resins, and polyimide resins.

[0148] Examples of prepregs contained in the insulating material that constitutes the sealing material 300 include resin-impregnated glass fibers (resin-impregnated glass cloth).

[0149] With regard to the prepreg contained in the insulating material that constitutes the sealing material 300, it is preferable that the diameter of the glass fiber (glass cloth) in the prepreg is 3 μm or more and 15 μm or less.

[0150] With respect to the prepreg contained in the insulating material constituting the sealing material 300, the resin content in the prepreg is preferably 50% by weight or more and 90% by weight or less.

[0151] Examples of inorganic materials contained in the insulating material that constitutes the sealing material 300 include glass.

[0152] The constituent material of the encapsulant 300 may be the same as or different from the constituent material of the base material 110 .

[0153] When the base material 110 and the sealing material 300 are both made of prepreg, the diameter of the glass fiber (glass cloth) in the prepreg, the density of the glass fiber (glass cloth) in the prepreg, the resin content in the prepreg, etc. may be the same or different between the base material 110 and the sealing material 300.

[0154] The insulating material that constitutes the sealing material 300 may contain a filler.

[0155] Examples of the filler contained in the insulating material that constitutes the sealing material 300 include inorganic fillers such as silica filler and alumina filler.

[0156] The sealing material 300 may be made up of only one layer, or may be made up of multiple layers.

[0157] When the sealing material 300 is made up of multiple layers, the constituent materials of the multiple layers may be the same as each other, may be different from each other, or may be partially different from each other.

[0158] The sealing material 300 is formed to seal the core substrate 100 and the capacitor component 200 by, for example, a method of thermocompressing an insulating resin sheet, or a method of applying an insulating resin paste and then thermally curing it.

[0159] In the capacitor-embedded substrate 1, the distance T1a (hereinafter simply referred to as distance T1a) in the thickness direction T from the surface P1a of the conductor wiring layer 270A on the first sealing portion 310 side to the surface Q1 of the sealing material 300 on the first sealing portion 310 side is greater than the distance T2a (hereinafter simply referred to as distance T2a) in the thickness direction T from the surface P2a of the conductor wiring layer 270A on the second sealing portion 320 side to the surface Q2 of the sealing material 300 on the second sealing portion 320 side.

[0160] In the capacitor-embedded substrate 1, the diameter R1a (hereinafter simply referred to as the diameter R1a) of the end of the through hole 261A on the first sealing portion 310 side is larger than the diameter R2a (hereinafter simply referred to as the diameter R2a) of the end of the through hole 261A on the second sealing portion 320 side.

[0161] In the capacitor-embedded substrate 1, because the distance T1a is greater than the distance T2a as described above, the thickness of the sealing material 300 (first sealing portion 310) present on the conductor wiring layer 270A on the first sealing portion 310 side is greater than the thickness of the sealing material 300 (second sealing portion 320) present on the conductor wiring layer 270A on the second sealing portion 320 side. Therefore, in the capacitor-embedded substrate 1, the sealing material 300 applies a greater stress to the conductor wiring layer 270A on the first sealing portion 310 side than to the conductor wiring layer 270A on the second sealing portion 320 side. In contrast, in the capacitor-embedded substrate 1, because the diameter R1a of the through hole 261A is larger than the diameter R2a as described above, the stress applied from the sealing material 300 to the conductor wiring layer 270A on the first sealing portion 310 side is dispersed, and therefore the conductor wiring layer 270A on the first sealing portion 310 side, and in turn the through conductor 260A on whose end the conductor wiring layer 270A is provided, are less likely to be damaged by cracks, etc. Furthermore, in the capacitor-embedded substrate 1, because the diameter R1a of the through hole 261A is larger than the diameter R2a as described above, that is, the diameter of the through hole 261A does not increase overall from the end on the first sealing portion 310 side to the end on the second sealing portion 320 side, the area of ​​the portion in the capacitor component 200 (capacitor body 210) that can exhibit capacitance does not decrease overall, and as a result, a decrease in the capacitance of the capacitor component 200 (capacitor body 210) is suppressed.

[0162] In the capacitor-embedded substrate 1, the distance T1b (hereinafter simply referred to as distance T1b) in the thickness direction T from the surface P1b of the conductor wiring layer 270B on the first sealing portion 310 side to the surface Q1 of the sealing material 300 on the first sealing portion 310 side is greater than the distance T2b (hereinafter simply referred to as distance T2b) in the thickness direction T from the surface P2b of the conductor wiring layer 270B on the second sealing portion 320 side to the surface Q2 of the sealing material 300 on the second sealing portion 320 side.

[0163] In the capacitor-embedded substrate 1, the diameter R1b (hereinafter simply referred to as diameter R1b) of the end of the through hole 261B on the first sealing portion 310 side is larger than the diameter R2b (hereinafter simply referred to as diameter R2b) of the end of the through hole 261B on the second sealing portion 320 side.

[0164] In the capacitor-embedded substrate 1, because the distance T1b is greater than the distance T2b as described above, the thickness of the sealing material 300 (first sealing portion 310) present on the conductor wiring layer 270B on the first sealing portion 310 side is greater than the thickness of the sealing material 300 (second sealing portion 320) present on the conductor wiring layer 270B on the second sealing portion 320 side. Therefore, in the capacitor-embedded substrate 1, the sealing material 300 applies a greater stress to the conductor wiring layer 270B on the first sealing portion 310 side than to the conductor wiring layer 270B on the second sealing portion 320 side. In contrast, in the capacitor-embedded substrate 1, because the diameter R1b of the through hole 261B is larger than the diameter R2b as described above, the stress applied from the sealing material 300 to the conductor wiring layer 270B on the first sealing portion 310 side is dispersed, and therefore the conductor wiring layer 270B on the first sealing portion 310 side, and in turn the through conductor 260B on whose end the conductor wiring layer 270B is provided, are less likely to be damaged by cracks, etc. Furthermore, in the capacitor-embedded substrate 1, because the diameter R1b of the through hole 261B is larger than the diameter R2b as described above, that is, the diameter of the through hole 261B does not increase overall from the end on the first sealing portion 310 side to the end on the second sealing portion 320 side, the area of ​​the portion in the capacitor component 200 (capacitor body 210) that can exhibit capacitance does not decrease overall, and as a result, a decrease in the capacitance of the capacitor component 200 (capacitor body 210) is suppressed.

[0165] From the above, the capacitor-embedded substrate 1 can realize a capacitor-embedded substrate that can suppress both damage to the through conductors (in FIG. 1, through conductors 260A and 260B) and the conductor wiring layers (in FIG. 1, conductor wiring layers 270A and 270B) provided on the ends thereof, and a decrease in capacitance.

[0166] The distance in the thickness direction from the surface of the conductor wiring layer on the first sealing portion side to the surface of the sealing material on the first sealing portion side is determined as the maximum distance in the thickness direction between the two surfaces.

[0167] The distance in the thickness direction from the surface of the conductor wiring layer on the second sealing portion side to the surface of the sealing material on the second sealing portion side is determined as the maximum distance in the thickness direction between the two surfaces.

[0168] The diameter of the end of the through hole on the first sealing portion side is determined as the equivalent circle diameter converted from the area of ​​the end when viewed in the thickness direction.

[0169] The diameter of the end of the through hole on the second sealing portion side is determined as the equivalent circle diameter converted from the area of ​​the end when viewed in the thickness direction.

[0170] In the capacitor-built-in substrate 1, both relationship A, that is, "the distance T1a is greater than the distance T2a, and the diameter R1a is greater than the diameter R2a," and relationship B, that is, "the distance T1b is greater than the distance T2b, and the diameter R1b is greater than the diameter R2b," are satisfied, but it is sufficient if at least one of relationship A and relationship B is satisfied. In other words, in the capacitor-built-in substrate 1, only relationship A may be satisfied, or only relationship B may be satisfied, or, as a preferred embodiment, both relationship A and relationship B may be satisfied.

[0171] As described above, in the capacitor-embedded substrate of the present invention, when there are multiple combinations of a through conductor provided in a through hole and a conductor wiring layer provided on both ends of the through conductor, it is sufficient that the feature that "in the thickness direction, the distance from the surface of the conductor wiring layer on the first sealing portion side to the surface of the sealing material on the first sealing portion side is greater than the distance from the surface of the conductor wiring layer on the second sealing portion side to the surface of the sealing material on the second sealing portion side, and the diameter of the end of the through hole on the first sealing portion side is greater than the diameter of the end of the through hole on the second sealing portion side" is true for at least one of the multiple combinations, and it is particularly preferable that this feature is true for all combinations.

[0172] The distance T1a and the distance T1b may be the same as each other or may be different from each other.

[0173] The distance T2a and the distance T2b may be the same as each other or may be different from each other.

[0174] The diameter R1a and the diameter R1b may be the same as each other or may be different from each other.

[0175] The diameter R2a and the diameter R2b may be the same as each other or may be different from each other.

[0176] It is preferable that diameter R3a of the portion of through-hole 261A that penetrates capacitor body 210 be smaller than diameter R1a of the end of through-hole 261A on the side of first sealing portion 310. In this case, a reduction in the area of ​​the portion of capacitor component 200 (capacitor body 210) that can exhibit capacitance is sufficiently suppressed, and therefore a decrease in the capacitance of capacitor component 200 (capacitor body 210) is sufficiently suppressed.

[0177] It is preferable that diameter R3b of the portion of through-hole 261B that penetrates capacitor body 210 be smaller than diameter R1b of the end of through-hole 261B on the side of first sealing portion 310. In this case, a reduction in the area of ​​the portion of capacitor component 200 (capacitor body 210) that can exhibit capacitance is sufficiently suppressed, and therefore a decrease in the capacitance of capacitor component 200 (capacitor body 210) is sufficiently suppressed.

[0178] It is preferable that diameter R3a of through hole 261A that penetrates capacitor body 210 be smaller than diameter R1a of the end of through hole 261A on the first sealing portion 310 side and diameter R2a of the end of through hole 261A on the second sealing portion 320 side. In this case, the reduction in the area of ​​the portion of capacitor component 200 (capacitor body 210) that can exhibit capacitance is further suppressed, and therefore, the reduction in the capacitance of capacitor component 200 (capacitor body 210) is further suppressed.

[0179] Note that diameter R3a of the portion of through hole 261A that penetrates capacitor body 210 may be smaller than diameter R1a of the end of through hole 261A on the first sealing portion 310 side, but larger than diameter R2a of the end of through hole 261A on the second sealing portion 320 side. For example, with regard to through hole 261B, in the example shown in FIG. 1 , diameter R3b of the portion of through hole 261B that penetrates capacitor body 210 is smaller than diameter R1b of the end of through hole 261B on the first sealing portion 310 side, but larger than diameter R2b of the end of through hole 261B on the second sealing portion 320 side.

[0180] As long as the diameter R1a of the end of through hole 261A on the first sealing portion 310 side is larger than the diameter R2a of the end of through hole 261A on the second sealing portion 320 side, the cross-sectional shape of through hole 261A along the thickness direction T is not particularly limited. The cross-sectional shape of through hole 261A may be, for example, a constricted shape in which the diameter is extremely small at the portion where through hole 261A penetrates capacitor body 210, or a tapered shape in which the diameter decreases from the end on the first sealing portion 310 side toward the end on the second sealing portion 320 side. In the example shown in FIG. 1 , the cross-sectional shape of through hole 261A is the constricted shape described above, which is a preferred aspect from the viewpoint of suppressing a reduction in the area of ​​the portion of capacitor component 200 (capacitor body 210) that can exhibit capacitance.

[0181] As for through hole 261B, as long as diameter R1b of the end on the first sealing portion 310 side is larger than diameter R2b of the end on the second sealing portion 320 side, its cross-sectional shape along the thickness direction T is not particularly limited. The cross-sectional shape of through hole 261B may be, for example, a constricted shape in which the diameter is extremely small at the portion where it penetrates capacitor body 210, or a tapered shape in which the diameter decreases from the end on the first sealing portion 310 side toward the end on the second sealing portion 320 side. In the example shown in FIG. 1 , the cross-sectional shape of through hole 261B is the tapered shape described above.

[0182] The cross-sectional shapes of the through-hole 261A and the through-hole 261B may be the same as each other or may be different from each other.

[0183] The linear expansion coefficient in the plane direction of the base material 110 is preferably 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material 300. In this case, the stress applied to the capacitor component 200 from the core substrate 100 and the sealing material 300 is likely to be reduced, making the capacitor component 200 less likely to be damaged by the stress. Furthermore, the thermal characteristics of the core substrate 100 and the sealing material 300 are likely to be balanced, making it less likely that the capacitor-embedded substrate 1 will warp due to differences in thermal characteristics.

[0184] When the linear expansion coefficient in the plane direction of the base material 110 is 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material 300, the linear expansion coefficient in the plane direction of the core portion 221 may be greater than 120% of the linear expansion coefficient in the plane direction of the sealing material 300. In this case, during heat treatment or the like of the capacitor-embedded substrate 1, the core substrate 100 and the sealing material 300 play a role in restraining the capacitor component 200, so that thermal expansion and thermal contraction of the capacitor component 200 are sufficiently suppressed, and as a result, damage to the through conductors (through conductors 260A and 260B in FIG. 1 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 1 ) provided on the ends thereof is sufficiently suppressed.

[0185] Note that even when the linear expansion coefficient in the plane direction of the base material 110 is not 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material 300, the linear expansion coefficient in the plane direction of the core portion 221 may be greater than 120% of the linear expansion coefficient in the plane direction of the sealing material 300. Even in this case, the sealing material 300 plays a role in restraining the capacitor component 200 during heat treatment or the like of the capacitor-embedded substrate 1, so that thermal expansion and thermal contraction of the capacitor component 200 are suppressed, and as a result, damage to the through conductors (through conductors 260A and 260B in FIG. 1 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 1 ) provided on the ends thereof is suppressed.

[0186] When the linear expansion coefficient of the base material 110 in the plane direction is 80% or more and 120% or less of the linear expansion coefficient of the sealing material 300 in the plane direction, the linear expansion coefficient of the core portion 221 in the plane direction may be 80% or more and 120% or less of the linear expansion coefficient of the sealing material 300 in the plane direction. In this case, the stress applied to the capacitor component 200 from the core substrate 100 and the sealing material 300 is more likely to be reduced, making it less likely that the capacitor component 200 will be damaged by the stress. Furthermore, the thermal characteristics of the core substrate 100, the capacitor component 200, and the sealing material 300 are more likely to be balanced, making it less likely that the capacitor-embedded substrate 1 will warp due to differences in thermal characteristics.

[0187] Note that even when the linear expansion coefficient in the plane direction of the base material 110 is not 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material 300, the linear expansion coefficient in the plane direction of the core portion 221 may be 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material 300. Even in this case, the stress applied to the capacitor component 200 from the sealing material 300 is likely to be reduced, making the capacitor component 200 less likely to be damaged by the stress. Furthermore, the thermal characteristics of the capacitor component 200 and the sealing material 300 are likely to be balanced, making it less likely that warping of the capacitor-embedded substrate 1 will occur due to differences in thermal characteristics.

[0188] It is preferable that the linear expansion coefficient in the plane direction of the base material 110 is the same as the linear expansion coefficient in the plane direction of the sealing material 300, and that the linear expansion coefficient in the plane direction of the base material 110 and the linear expansion coefficient in the plane direction of the sealing material 300 are smaller than the linear expansion coefficient in the plane direction of the core portion 221. In this case, during heat treatment or the like of the capacitor-embedded substrate 1, the core substrate 100 and the sealing material 300 play a role in restraining the capacitor component 200, so that thermal expansion and thermal contraction of the capacitor component 200 are sufficiently suppressed, and as a result, damage to the through conductors (through conductors 260A and 260B in FIG. 1 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 1 ) provided on the ends thereof is sufficiently suppressed.

[0189] It is preferable that the linear expansion coefficient of the base material 110 in the plane direction is smaller than the linear expansion coefficient of the sealing material 300 in the plane direction, and that the linear expansion coefficient of the sealing material 300 in the plane direction is smaller than the linear expansion coefficient of the core portion 221 in the plane direction. In this case, the curing temperature (e.g., thermosetting temperature) of the sealing material 300, which has a larger linear expansion coefficient in the plane direction than the base material 110, is likely to be lower than the curing temperature (e.g., thermosetting temperature) of the base material 110. Therefore, during heat treatment or the like on the capacitor-embedded substrate 1, the core substrate 100 plays a role in restraining the capacitor component 200, and failure and characteristic degradation of the capacitor component 200 due to heat when curing (e.g., thermosetting) the sealing material 300 are less likely to occur.

[0190] The linear expansion coefficient in the plane direction of the target component (e.g., substrate, core, sealing material, etc.) of the capacitor-embedded substrate may be the linear expansion coefficient in any direction among the plane directions (e.g., the first direction U or the second direction V in Figure 1), and is determined by thermomechanical analysis (TMA) or dynamic mechanical analysis (DMA). Note that if it is difficult to directly remove (extract) the target component from the capacitor-embedded substrate, a measuring component made of the same material as the target component may be separately prepared, and the linear expansion coefficient in the plane direction of the measuring component may be measured using the method described above.

[0191] The capacitor-embedded substrate 1 may further include external electrode layers 400A provided on both surfaces of the sealing material 300 that face each other in the thickness direction T and electrically connected to the conductor wiring layer 270A. In this case, the external electrode layers 400A function as connection terminals of the capacitor-embedded substrate 1. In the example shown in FIG. 1 , the external electrode layers 400A function as connection terminals for the conductor wiring layer 270A, and therefore as connection terminals for the anode layer 220.

[0192] Examples of materials that can be used to form the external electrode layer 400A include metal materials containing low-resistance metals such as copper, gold, and silver.

[0193] The capacitor-embedded substrate 1 may further include via conductors 410A that penetrate the sealing material 300 in the thickness direction T and are connected to the conductor wiring layer 270A and the external electrode layer 400A.

[0194] Examples of materials constituting the via conductor 410A include metal materials containing low-resistance metals such as copper, gold, and silver.

[0195] The via conductor 410A is formed, for example, by plating the inner wall surface of a through hole that penetrates the sealing material 300 in the thickness direction T with the above-mentioned metal material, or by filling it with a conductive paste and then performing a heat treatment.

[0196] The capacitor-embedded substrate 1 may further include external electrode layers 400B provided on both surfaces of the sealing material 300 that face each other in the thickness direction T and electrically connected to the conductor wiring layer 270B. In this case, the external electrode layers 400B function as connection terminals of the capacitor-embedded substrate 1. In the example shown in FIG. 1 , the external electrode layers 400B function as connection terminals for the conductor wiring layer 270B, and therefore as connection terminals for the cathode layer 240.

[0197] Examples of materials that can be used to form the external electrode layer 400B include metal materials containing low-resistance metals such as copper, gold, and silver.

[0198] The constituent materials of the external electrode layer 400A and the external electrode layer 400B may be the same as or different from each other.

[0199] The capacitor-embedded substrate 1 may further include via conductors 410B that penetrate the sealing material 300 in the thickness direction T and are connected to the conductor wiring layer 270B and the external electrode layer 400B.

[0200] Examples of materials constituting the via conductors 410B include metal materials containing low-resistance metals such as copper, gold, and silver.

[0201] The constituent materials of the via conductors 410A and 410B may be the same as or different from each other.

[0202] The via conductor 410B is formed, for example, by plating the inner wall surface of a through hole that penetrates the sealing material 300 in the thickness direction T with the above-mentioned metal material, or by filling it with a conductive paste and then performing a heat treatment.

[0203] In the capacitor-embedded substrate 1, the other surface of the core substrate 100 (the lower surface in FIG. 1 ) and the other surface of the capacitor component 200 (the lower surface in FIG. 1 ) preferably exist on the same plane (on the dashed line in FIG. 1 ). Specifically, the surface of the core substrate 100 facing the second sealing portion 320 and the surface of the capacitor component 200 facing the second sealing portion 320 preferably exist on the same plane. In the example shown in FIG. 1 , the surface of the core substrate 100 facing the second sealing portion 320 corresponds to the surface of the base material 110 facing the second sealing portion 320. In addition, in the example shown in FIG. 1 , the surface of the capacitor component 200 facing the second sealing portion 320 corresponds to the surfaces of the conductor wiring layers 270A and 270B facing the second sealing portion 320 (surfaces P2a and P2b in FIG. 1 ). In other words, in the example shown in Figure 1, it is preferable that the surface of the base material 110 facing the second sealing section 320 and the surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the second sealing section 320 are on the same plane.

[0204] In this specification, "the surface of one component and the surface of the other component are on the same plane" means that the maximum distance in the thickness direction from the surface of one component (e.g., a core substrate) to the surface of the other component (e.g., a capacitor component) is 10 μm or less.

[0205] The capacitor-embedded substrate 1 is manufactured, for example, as follows. First, a core substrate 100 having an opening 130 formed in the thickness direction T and a capacitor component 200 are prepared. Next, the core substrate 100 is attached to a support tape from the other surface (the lower surface in FIG. 1 ) side, thereby fixing the core substrate 100 on the support tape. Next, the capacitor component 200 is placed in the opening 130 of the core substrate 100 and pressed against the support tape exposed in the opening 130 of the core substrate 100, thereby fixing the capacitor component 200 on the support tape. Then, a sealing material including a first sealing portion 310 is formed so as to seal the core substrate 100 and the capacitor component 200 from one surface (the upper surface in FIG. 1 ) side to the support tape side, and the support tape is then removed. Thereafter, a sealing material including a second sealing portion 320 is formed so as to contact the previously formed sealing material while sealing the core substrate 100 and the capacitor component 200 from the other surface (the lower surface in FIG. 1 ), thereby obtaining the sealing material 300. Furthermore, as necessary, external electrode layers 400A, 400B, via conductors 410A, 410B, etc. are formed on the sealing material 300, thereby obtaining the capacitor-embedded substrate 1.

[0206] When the capacitor-embedded substrate 1 is manufactured, for example, as described above, the other surface (the lower surface in FIG. 1 ) of the core substrate 100 and the other surface (the lower surface in FIG. 1 ) of the capacitor component 200 in the capacitor-embedded substrate 1 will be on the same plane (on the dashed line in FIG. 1 ).

[0207] [Embodiment 2] In a capacitor-embedded substrate according to embodiment 2 of the present invention, the capacitor component further includes a protective layer that covers at least a portion of at least one of the surfaces of the conductor wiring layer facing the first sealing portion and the second sealing portion.

[0208] Except for the above points, the capacitor-embedded substrate of the second embodiment of the present invention is similar to the capacitor-embedded substrate of the first embodiment of the present invention.

[0209] FIG. 2 is a cross-sectional view showing an example of a capacitor-embedded substrate according to a second embodiment of the present invention.

[0210] In the capacitor-embedded substrate 2 shown in FIG. 2, the capacitor component 200 further includes a protective layer 295 .

[0211] The protective layer 295 covers at least a portion of at least one of the surfaces P1a of the conductor wiring layer 270A facing the first sealing portion 310 and the surface P2a of the conductor wiring layer 270A facing the second sealing portion 320. In the example shown in Fig. 2, the protective layer 295 covers both the surface P1a of the conductor wiring layer 270A facing the first sealing portion 310 and the surface P2a of the conductor wiring layer 270A facing the second sealing portion 320. In this way, the conductor wiring layer 270A is protected by the protective layer 295.

[0212] The protective layer 295 may be provided on only one of the surface P1a on the first sealing portion 310 side and the surface P2a on the second sealing portion 320 side of the conductor wiring layer 270A.

[0213] The protective layer 295 covers at least a portion of at least one of the surface P1b of the conductor wiring layer 270B on the first sealing portion 310 side and the surface P2b on the second sealing portion 320 side. In the example shown in Fig. 2, the protective layer 295 covers both the surface P1b of the conductor wiring layer 270B on the first sealing portion 310 side and the surface P2b on the second sealing portion 320 side. In this way, the conductor wiring layer 270B is protected by the protective layer 295.

[0214] The protective layer 295 may be provided on only one of the surface P1b on the first sealing portion 310 side and the surface P2b on the second sealing portion 320 side of the conductor wiring layer 270B.

[0215] The protective layer 295 is preferably provided from a surface P1a of the conductor wiring layer 270A facing the first sealing portion 310 to a surface P1b of the conductor wiring layer 270B facing the first sealing portion 310. In other words, the protective layer 295 is preferably provided over the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the first sealing portion 310. Specifically, the protective layer 295 is preferably provided so as to cover the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the first sealing portion 310.

[0216] The protective layer 295 is preferably provided from a surface P2a of the conductor wiring layer 270A facing the second sealing portion 320 to a surface P2b of the conductor wiring layer 270B facing the second sealing portion 320. In other words, the protective layer 295 is preferably provided over the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the second sealing portion 320. Specifically, the protective layer 295 is preferably provided so as to cover the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the second sealing portion 320.

[0217] It is particularly preferable that the protective layer 295 is provided from the surface P1a of the conductor wiring layer 270A facing the first sealing portion 310 to the surface P1b of the conductor wiring layer 270B facing the first sealing portion 310, and from the surface P2a of the conductor wiring layer 270A facing the second sealing portion 320 to the surface P2b of the conductor wiring layer 270B facing the second sealing portion 320. That is, it is particularly preferable that the protective layer 295 is provided over the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the first sealing portion 310 and the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the second sealing portion 320. Specifically, it is particularly preferable that the protective layer 295 is provided so as to cover the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the first sealing portion 310 and the entire surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B facing the second sealing portion 320.

[0218] When viewed in the thickness direction T, the protective layer 295 preferably overlaps the entire capacitor body 210 .

[0219] In the planar direction (first direction U in FIG. 2), both ends of the protective layer 295 are preferably located at the same positions as both ends of the capacitor body 210 .

[0220] The coefficient of linear expansion in the planar direction of the protective layer 295 is preferably 80% or more and 120% or less of the coefficient of linear expansion in the planar direction of the core 221. In this case, the stress applied from the protective layer 295 to the conductor wiring layer (in FIG. 2, the conductor wiring layer 270A and the conductor wiring layer 270B), and further the stress applied from the protective layer 295 to the through conductor (in FIG. 2, the through conductor 260A and the through conductor 260B), is likely to be reduced, making it less likely that the through conductor (in FIG. 2, the through conductor 260A and the through conductor 260B) will be damaged by the above-mentioned stress.

[0221] When the linear expansion coefficient of the protective layer 295 in the plane direction is 80% or more and 120% or less of the linear expansion coefficient of the core portion 221 in the plane direction, the linear expansion coefficient of the protective layer 295 in the plane direction is preferably greater than 120% of the linear expansion coefficient of the sealing material 300 in the plane direction. In this case, during heat treatment or the like of the capacitor-embedded substrate 2, the sealing material 300 plays a role in restraining the capacitor component 200 having the protective layer 295, thereby suppressing thermal expansion and thermal contraction of the capacitor component 200 having the protective layer 295, and as a result, suppressing damage to the through conductors (through conductors 260A and 260B in FIG. 2 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 2 ) provided on the ends thereof.

[0222] When the linear expansion coefficient of the protective layer 295 in the plane direction is 80% or more and 120% or less of the linear expansion coefficient of the core portion 221 in the plane direction, the linear expansion coefficient of the protective layer 295 in the plane direction is preferably greater than 120% of the linear expansion coefficient of the base material 110 in the plane direction. In this case, during heat treatment or the like of the capacitor-embedded substrate 2, the core substrate 100 plays a role in restraining the capacitor component 200 having the protective layer 295, thereby suppressing thermal expansion and thermal contraction of the capacitor component 200 having the protective layer 295, and as a result, suppressing damage to the through conductors (through conductors 260A and 260B in FIG. 2 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 2 ) provided on the ends thereof.

[0223] It is particularly preferable that the linear expansion coefficient of the protective layer 295 in the plane direction is 80% or more and 120% or less of the linear expansion coefficient of the core portion 221 in the plane direction, that the linear expansion coefficient of the protective layer 295 in the plane direction is greater than 120% of the linear expansion coefficient of the sealing material 300 in the plane direction, and that the linear expansion coefficient of the protective layer 295 in the plane direction is greater than 120% of the linear expansion coefficient of the base material 110 in the plane direction. In this case, during heat treatment or the like of the capacitor-embedded substrate 2, the core substrate 100 and the sealing material 300 play a role in restraining the capacitor component 200 having the protective layer 295, so that thermal expansion and thermal contraction of the capacitor component 200 having the protective layer 295 are sufficiently suppressed, and as a result, damage to the through conductors (through conductors 260A and 260B in FIG. 2 ) and the conductor wiring layers (conductor wiring layers 270A and 270B in FIG. 2 ) provided on the ends thereof is sufficiently suppressed.

[0224] When the linear expansion coefficient of the base material 110 in the plane direction is the same as the linear expansion coefficient of the sealing material 300 in the plane direction, and the linear expansion coefficients of the base material 110 in the plane direction and the sealing material 300 in the plane direction are smaller than the linear expansion coefficients of the core portion 221 in the plane direction, it is preferable that the linear expansion coefficient of the protective layer 295 in the plane direction is the same as the linear expansion coefficients of the base material 110 in the plane direction and the sealing material 300 in the plane direction. In other words, it is preferable that the linear expansion coefficients of the base material 110 in the plane direction, the sealing material 300 in the plane direction, and the protective layer 295 in the plane direction are the same, and that the linear expansion coefficients of the base material 110 in the plane direction, the sealing material 300 in the plane direction, and the protective layer 295 in the plane direction are smaller than the linear expansion coefficient of the core portion 221 in the plane direction. In this case, the stress applied to the capacitor component 200 from the core substrate 100 and the sealing material 300 is likely to be reduced, making the capacitor component 200 less likely to be damaged by the stress. Furthermore, the stress applied from the protective layer 295 to the conductor wiring layer (the conductor wiring layer 270A and the conductor wiring layer 270B in FIG. 2 ), and therefore the stress applied from the protective layer 295 to the through conductors (the through conductors 260A and the through conductors 260B in FIG. 2 ), is likely to be reduced, making the through conductors (the through conductors 260A and the through conductors 260B in FIG. 2 ) less likely to be damaged by the stress.

[0225] When the linear expansion coefficient of the base material 110 in the plane direction is the same as the linear expansion coefficient of the encapsulant 300 in the plane direction, and the linear expansion coefficients of the base material 110 in the plane direction and the linear expansion coefficients of the encapsulant 300 in the plane direction are smaller than the linear expansion coefficients of the core portion 221 in the plane direction, it is preferable that the constituent material of the protective layer 295 is the same as the constituent material of the encapsulant 300. In this case, processing, treatment, etc. of the encapsulant 300 and the protective layer 295 are facilitated. For example, when forming the via conductors 410A and 410B, this facilitates laser processing for forming through holes that penetrate the encapsulant 300 and the protective layer 295 in the thickness direction T, desmearing for removing residue generated during the laser processing, plating for plating the inner wall surfaces of the through holes with a metal material, etc.

[0226] When the linear expansion coefficient of the base material 110 in the plane direction is smaller than the linear expansion coefficient of the sealing material 300 in the plane direction and is smaller than the linear expansion coefficient of the sealing material 300 in the plane direction, it is preferable that the linear expansion coefficient of the protective layer 295 in the plane direction is the same as the linear expansion coefficient of the base material 110. In other words, it is preferable that the linear expansion coefficient of the base material 110 in the plane direction and the linear expansion coefficient of the protective layer 295 in the plane direction are the same, and that the linear expansion coefficients of the base material 110 in the plane direction and the linear expansion coefficients of the protective layer 295 in the plane direction are smaller than the linear expansion coefficient of the sealing material 300 in the plane direction, and that the linear expansion coefficient of the sealing material 300 in the plane direction is smaller than the linear expansion coefficient of the core part 221 in the plane direction. In this case, during heat treatment of the capacitor-embedded substrate 1, the core substrate 100 restrains the capacitor component 200, and the protective layer 295 restrains the portions of the capacitor component 200 other than the protective layer 295, so that thermal expansion and thermal contraction of the capacitor component 200 are sufficiently suppressed, and as a result, damage to the through conductors (in Figure 2, through conductors 260A and 260B) and the conductor wiring layers (in Figure 2, conductor wiring layers 270A and conductor wiring layers 270B) provided on the ends thereof is sufficiently suppressed.

[0227] When the linear expansion coefficient of base material 110 in the plane direction is smaller than the linear expansion coefficient of sealing material 300 in the plane direction, and when the linear expansion coefficient of sealing material 300 in the plane direction is smaller than the linear expansion coefficient of core portion 221 in the plane direction, it is preferable that the constituent material of protective layer 295 is the same as the constituent material of sealing material 300. In this case, processing, treatment, etc. of sealing material 300 and protective layer 295 are facilitated. For example, when forming via conductors 410A and 410B, this facilitates laser processing to form through holes that penetrate sealing material 300 and protective layer 295 in the thickness direction T, desmearing to remove residue generated during the laser processing, plating to plate the inner wall surfaces of the through holes with a metal material, etc.

[0228] The protective layer 295 is preferably made of an insulating material.

[0229] The insulating material constituting the protective layer 295 may contain insulating resin, prepreg, inorganic material, a mixture thereof, or the like.

[0230] Examples of insulating resins contained in the insulating material that forms the protective layer 295 include epoxy resin, phenol resin, and polyimide resin.

[0231] Examples of prepreg contained in the insulating material that forms the protective layer 295 include resin-impregnated glass fiber (resin-impregnated glass cloth).

[0232] With regard to the prepreg contained in the insulating material that constitutes the protective layer 295, it is preferable that the diameter of the glass fiber (glass cloth) in the prepreg is 3 μm or more and 15 μm or less.

[0233] With respect to the prepreg contained in the insulating material that constitutes the protective layer 295, the resin content in the prepreg is preferably 50% by weight or more and 90% by weight or less.

[0234] Examples of inorganic materials contained in the insulating material that constitutes the protective layer 295 include glass.

[0235] The material of the protective layer 295 may be the same as or different from the material of the substrate 110 .

[0236] When the base material 110 and the protective layer 295 are both made of prepreg, the diameter of the glass fiber (glass cloth) in the prepreg, the density of the glass fiber (glass cloth) in the prepreg, the resin content in the prepreg, etc. may be the same or different between the base material 110 and the protective layer 295.

[0237] The constituent material of protective layer 295 may be the same as or different from the constituent material of sealing material 300. When sealing material 300 and protective layer 295 are made of the same material, processing, treatment, etc. of sealing material 300 and protective layer 295 are facilitated. For example, when forming via conductors 410A and 410B, it becomes easy to perform laser processing to form through holes that penetrate sealing material 300 and protective layer 295 in thickness direction T, desmearing to remove residues generated during the laser processing, plating to plate the inner wall surfaces of the through holes with a metal material, etc.

[0238] When the sealing material 300 and the protective layer 295 are both made of prepreg, the diameter of the glass fiber (glass cloth) in the prepreg, the density of the glass fiber (glass cloth) in the prepreg, the resin content in the prepreg, etc. may be the same or different between the sealing material 300 and the protective layer 295.

[0239] The same protective layer 295 may be made up of only one layer or multiple layers.

[0240] When the same protective layer 295 is made up of a plurality of layers, the constituent materials of the plurality of layers may be the same as each other, may be different from each other, or may be partially different from each other.

[0241] The protective layer 295 is formed so as to cover at least a portion of at least one of the surfaces P1a on the first sealing portion 310 side and the surface P2a on the second sealing portion 320 side of the conductor wiring layer 270A, for example, by a method of thermocompressing an insulating resin sheet or a method of applying an insulating resin paste and then thermally curing it.

[0242] In the capacitor-embedded substrate 2, similarly to the capacitor-embedded substrate 1, the other surface (the lower surface in FIG. 2 ) of the core substrate 100 and the other surface (the lower surface in FIG. 2 ) of the capacitor component 200 preferably exist on the same plane (on the dashed line in FIG. 2 ). In the example shown in FIG. 2 , the other surface of the core substrate 100, specifically the surface of the core substrate 100 facing the second sealing portion 320, corresponds to the surface of the base material 110 facing the second sealing portion 320. In the example shown in FIG. 2 , the other surface of the capacitor component 200, specifically the surface of the capacitor component 200 facing the second sealing portion 320, corresponds to the surface of the protective layer 295 facing the second sealing portion 320. In the example shown in FIG. 2 , the surface of the base material 110 facing the second sealing portion 320 and the surface of the protective layer 295 facing the second sealing portion 320 preferably exist on the same plane.

[0243] In the capacitor-embedded substrate 2 , the protective layer 295 may have an opening in the thickness direction T, and the opening in the protective layer 295 may be filled with a sealing material 300 .

[0244] FIG. 3 is a schematic cross-sectional view showing an example of a capacitor-embedded substrate according to a modified example of the second embodiment of the present invention.

[0245] In the capacitor-embedded substrate 2′ shown in Fig. 3, the protective layer 295 has an opening 296 formed in the thickness direction T. In the example shown in Fig. 3, the opening 296 penetrates the protective layer 295 in the thickness direction T. That is, in the example shown in Fig. 3, the protective layer 295 has the opening 296 formed in the thickness direction T so that a portion of each of the conductor wiring layer 270A and the conductor wiring layer 270B is exposed.

[0246] The openings 296 of the protective layer 295 are filled with a sealing material 300. In the example shown in Fig. 3, portions of the conductor wiring layers 270A and 270B exposed in the openings 296 of the protective layer 295 are covered with the sealing material 300 filled in the openings 296 of the protective layer 295. This increases the contact area of ​​the sealing material 300 with the capacitor component 200, thereby improving the adhesion of the sealing material 300 to the capacitor component 200.

[0247] The opening 296 does not have to penetrate the protective layer 295 in the thickness direction T. In other words, the conductor wiring layer 270A or the conductor wiring layer 270B does not have to be exposed within the opening 296 of the protective layer 295.

[0248] The opening 296 of the protective layer 295 may be hole-shaped (hole-shaped) or slit-shaped (groove-shaped) when viewed from the thickness direction T.

[0249] The number of openings 296 provided in the same protective layer 295 may be one or more.

[0250] When a plurality of openings 296 are provided in the same protective layer 295, the plurality of openings 296 may be arranged regularly or irregularly when viewed from the thickness direction T.

[0251] Third Embodiment In a capacitor-embedded substrate according to a third embodiment of the present invention, the core substrate further includes an electrode provided on at least one of the surface of the base facing the first sealing portion and the surface facing the second sealing portion.

[0252] Except for the above points, the capacitor-embedded substrate of the third embodiment of the present invention is similar to the capacitor-embedded substrate of the first embodiment of the present invention.

[0253] FIG. 4 is a cross-sectional view showing an example of a capacitor-embedded substrate according to a third embodiment of the present invention.

[0254] In the capacitor-embedded substrate 3 shown in FIG. 4, the core substrate 100 further has an electrode 120 .

[0255] The electrode 120 is provided on at least one of the surface of the base material 110 facing the first sealing unit 310 (the upper surface in FIG. 4 ) and the surface of the base material 110 facing the second sealing unit 320 (the lower surface in FIG. 4 ). In the example shown in FIG. 4 , the electrode 120 is provided on both the surface of the base material 110 facing the first sealing unit 310 and the surface of the base material 110 facing the second sealing unit 320.

[0256] The electrode 120 may be provided on only one of the surfaces of the base material 110 on the first sealing portion 310 side and the surface on the second sealing portion 320 side.

[0257] Examples of materials that can be used to form the electrodes 120 include metal materials containing low-resistance metals such as copper, gold, and silver.

[0258] In the capacitor-embedded substrate 3, similarly to the capacitor-embedded substrate 1, the other surface (the lower surface in FIG. 4 ) of the core substrate 100 and the other surface (the lower surface in FIG. 4 ) of the capacitor component 200 preferably exist on the same plane (on the dashed line in FIG. 4 ). In the example shown in FIG. 4 , the other surface of the core substrate 100, specifically the surface of the core substrate 100 facing the second sealing portion 320, corresponds to the surface of the electrode 120 facing the second sealing portion 320. In the example shown in FIG. 4 , the other surface of the capacitor component 200, specifically the surface of the capacitor component 200 facing the second sealing portion 320, corresponds to the surfaces of the conductor wiring layers 270A and 270B facing the second sealing portion 320 (surfaces P2a and P2b in FIG. 4 ). In the example shown in FIG. 4, it is preferable that the surface of the electrode 120 on the second sealing portion 320 side and the surfaces of the conductor wiring layer 270A and the conductor wiring layer 270B on the second sealing portion 320 side are on the same plane.

[0259] [Embodiment 4] In a capacitor-embedded substrate according to embodiment 4 of the present invention, the capacitor component further has a protective layer that covers at least a portion of at least one of the surfaces of the conductor wiring layer facing the first sealing portion and the second sealing portion, and the core substrate further has an electrode provided on at least one of the surfaces of the base facing the first sealing portion and the second sealing portion.

[0260] Except for the above points, the capacitor-embedded substrate of the fourth embodiment of the present invention is similar to the capacitor-embedded substrate of the first embodiment of the present invention.

[0261] FIG. 5 is a cross-sectional view showing an example of a capacitor-embedded substrate according to a fourth embodiment of the present invention.

[0262] In the capacitor-embedded substrate 4 shown in FIG. 5, the capacitor component 200 further includes a protective layer 295 .

[0263] The configuration of the protective layer 295 in the capacitor-built-in substrate 4 may be the same as the configuration of the protective layer 295 in the capacitor-built-in substrate 2 (see FIG. 2). For example, in the capacitor-built-in substrate 4, the protective layer 295 may have an opening in the thickness direction T, and further, the opening in the protective layer 295 may be filled with a sealing material 300. The configuration of such an opening in the protective layer 295 may be the same as the configuration of the opening 296 in the protective layer 295 in the capacitor-built-in substrate 2′ (see FIG. 3).

[0264] In the capacitor-embedded substrate 4 , the core substrate 100 further has an electrode 120 .

[0265] The form of the electrodes 120 in the capacitor-built-in substrate 4 may be the same as the form of the electrodes 120 in the capacitor-built-in substrate 3 (see FIG. 4).

[0266] In the capacitor-embedded substrate 4, similarly to the capacitor-embedded substrate 1, the other surface (the lower surface in FIG. 5 ) of the core substrate 100 and the other surface (the lower surface in FIG. 5 ) of the capacitor component 200 preferably exist on the same plane (on the dashed line in FIG. 5 ). In the example shown in FIG. 5 , the other surface of the core substrate 100, specifically the surface of the core substrate 100 facing the second sealing portion 320, corresponds to the surface of the electrode 120 facing the second sealing portion 320. In the example shown in FIG. 5 , the other surface of the capacitor component 200, specifically the surface of the capacitor component 200 facing the second sealing portion 320, corresponds to the surface of the protective layer 295 facing the second sealing portion 320. In the example shown in FIG. 5 , the surface of the electrode 120 facing the second sealing portion 320 and the surface of the protective layer 295 facing the second sealing portion 320 preferably exist on the same plane.

[0267] In the capacitor-embedded substrate of the present invention, the capacitor component (capacitor body) is not limited to an electrolytic capacitor including the solid electrolytic capacitor described above. In the capacitor-embedded substrate of the present invention, the capacitor component (capacitor body) may be, for example, a ceramic capacitor using barium titanate, silicon nitride (SiN), silicon dioxide (SiO ２), a thin film capacitor using hydrogen fluoride (HF) or the like, a trench capacitor having an MIM (Metal Insulator Metal) structure, or the like may be configured.

[0268] In the capacitor-embedded substrate of the present invention, from the viewpoint of reducing the thickness and increasing the area of ​​the capacitor component and improving the mechanical properties of the capacitor component, such as rigidity and flexibility, the capacitor component (capacitor body) preferably constitutes a capacitor whose base material is a metal such as aluminum, and more preferably constitutes an electrolytic capacitor whose base material is a metal such as aluminum.

[0269] The capacitor-embedded substrate of the present invention may be used in, for example, 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 of the present invention (for example, an external electrode layer).

[0270] The electronic components used in the composite electronic component may be passive elements, active elements, both passive and active elements, or a composite of passive and active elements.

[0271] An example of a passive element is an inductor.

[0272] Examples of active elements include a memory, a GPU (Graphical Processing Unit), a CPU (Central Processing Unit), an MPU (Micro Processing Unit), and a PMIC (Power Management IC).

[0273] When the capacitor-embedded substrate of the present invention is used in a composite electronic component, the capacitor-embedded substrate of the present invention is used, for example, as a substrate for mounting electronic components. In this case, by forming the capacitor-embedded substrate of the present invention as a whole in a sheet shape and further forming the electronic components to be mounted on the capacitor-embedded substrate of the present invention in a sheet shape, it becomes possible to electrically connect the capacitor-embedded substrate of the present invention and the electronic components in the thickness direction via through conductors that penetrate the electronic components in the thickness direction. As a result, it becomes possible to configure passive elements and active elements as electronic components like a single module.

[0274] For example, a switching regulator can be formed by electrically connecting the capacitor element of the present invention between a voltage regulator including a semiconductor active element and a load to which the converted DC voltage is supplied.

[0275] In the composite electronic component, a circuit layer may be formed on the sealing material of the capacitor-embedded substrate of the present invention, and the circuit layer may then be electrically connected to a passive element or an active element as an electronic component.

[0276] The present specification discloses the following:

[0277] <1> A capacitor comprising: a core substrate having an opening in a thickness direction; a capacitor component provided in the opening of the core substrate; and a sealing material sealing the core substrate and the capacitor component, wherein the core substrate has a base material having the opening; the capacitor component comprising: a capacitor body having an anode layer having a core, a dielectric layer, and a cathode layer facing the anode layer in the thickness direction with the dielectric layer interposed therebetween; a through conductor provided on at least an inner wall surface of a through hole penetrating at least the capacitor body in the thickness direction; and a conductor wiring layer provided on both end portions of the through conductor facing each other in the thickness direction; and the sealing material having a first sealing portion covering one surface of each of the core substrate and the capacitor component in the thickness direction, a distance in the thickness direction from a surface of the conductor wiring layer on the first sealing portion side to a surface of the sealing material on the first sealing portion side is greater than a distance from a surface of the conductor wiring layer on the second sealing portion side to a surface of the sealing material on the second sealing portion side, and a diameter of an end of the through hole on the first sealing portion side is greater than a diameter of an end of the through hole on the second sealing portion side.

[0278] <2> The capacitor-embedded substrate according to <1>, wherein the diameter of the through hole at the portion that penetrates the capacitor body is smaller than the diameter of the end of the through hole on the first sealing portion side.

[0279] <3> The capacitor-embedded substrate according to <2>, wherein the diameter of the portion of the through hole that penetrates the capacitor body is smaller than the diameter of the end of the through hole on the first sealing portion side and the diameter of the end of the through hole on the second sealing portion side.

[0280] <4> The capacitor-embedded substrate according to any one of <1> to <3>, wherein the base has a linear expansion coefficient in a plane direction perpendicular to the thickness direction that is 80% or more and 120% or less of the linear expansion coefficient in the plane direction of the sealing material.

[0281] <5> The capacitor-embedded substrate according to any one of <1> to <4>, wherein the core has a linear expansion coefficient in a plane direction perpendicular to the thickness direction that is greater than 120% of the linear expansion coefficient of the sealing material in the plane direction.

[0282] <6> The capacitor-embedded substrate according to any one of <1> to <4>, wherein the core has a linear expansion coefficient in a plane direction perpendicular to the thickness direction, which is 80% or more and 120% or less of the linear expansion coefficient of the sealing material in the plane direction.

[0283] <7> The capacitor-embedded substrate according to any one of <1> to <6>, wherein the capacitor component further has a protective layer covering at least a part of at least one of a surface of the conductor wiring layer on the first sealing portion side and a surface of the conductor wiring layer on the second sealing portion side.

[0284] <8> The capacitor-embedded substrate according to <7>, wherein the protective layer has a linear expansion coefficient in a plane direction perpendicular to the thickness direction that is 80% or more and 120% or less of the linear expansion coefficient of the core portion in the plane direction.

[0285] <9> The capacitor-embedded substrate according to <8>, wherein the protective layer has a linear expansion coefficient in the plane direction that is greater than 120% of the linear expansion coefficient in the plane direction of the sealing material.

[0286] <10> The capacitor-embedded substrate according to <8> or <9>, wherein the protective layer has a linear expansion coefficient in the plane direction that is greater than 120% of the linear expansion coefficient of the base material in the plane direction.

[0287] <11> The capacitor-embedded substrate according to any one of <7> to <10>, wherein the protective layer has an opening in the thickness direction, and the opening in the protective layer is filled with the sealing material.

[0288] <12> The capacitor-embedded substrate according to any one of <1> to <11>, wherein the core substrate further has an electrode provided on at least one of a surface of the base material facing the first sealing portion and a surface of the base material facing the second sealing portion.

[0289] <13> The capacitor-embedded substrate according to any one of <1> to <12>, wherein the anode layer has the core and a porous portion provided on at least one of both surfaces of the core facing each other in the thickness direction, the dielectric layer is provided on a surface of the porous portion, and the cathode layer is provided on a surface of the dielectric layer.

[0290] DESCRIPTION OF SYMBOLS 1, 2, 2', 3, 4 Capacitor-embedded substrate 100 Core substrate 110 Base material 120 Electrode 130 Opening (cavity) 200 Capacitor component 210 Capacitor body 220 Anode layer 221 Core portion 222 Porous portion 230 Dielectric layer 240 Cathode layer 241 Solid electrolyte layer 242 Conductor layer 243 Conductive resin layer 244 Metal layer 250 Mask layer 260A, 260B Through conductor 261A, 261B Through hole 270A, 270B Conductor wiring layer 280A, 280B Resin-filled portion 285, 410A, 410B Via conductor 290 Sealing layer 295 Protective layer 296 Opening 300 Sealing material 310 First sealing portion 320 Second sealing portion 400A, 400B External electrode layer P1a, P1b Surface of conductor wiring layer on the first sealing portion side P2a, P2b Surface of conductor wiring layer on the second sealing portion side Q1 Surface of sealing material on the first sealing portion side Q2 Surface of sealing material on the second sealing portion side R1a, R1b Diameter of end of through hole on the first sealing portion side R2a, R2b Diameter of end of through hole on the second sealing portion side R3a, R3b Diameter of part of through hole penetrating capacitor body T1a, T1b Distance in thickness direction from surface of conductor wiring layer on the first sealing portion side to surface of sealing material on the first sealing portion side T2a, T2b Distance in thickness direction from surface of conductor wiring layer on the second sealing portion side to surface of sealing material on the second sealing portion side T Thickness direction U First direction V Second direction

Claims

1. a core substrate having an opening in a thickness direction; a capacitor component provided in the opening of the core substrate; a sealing material that seals the core substrate and the capacitor component, the core substrate has a base material in which the opening is provided, the capacitor component comprises: a capacitor body having an anode layer having a core, a dielectric layer, and a cathode layer facing the anode layer with the dielectric layer interposed therebetween in the thickness direction; a through conductor provided on at least an inner wall surface of a through hole penetrating at least the capacitor body in the thickness direction; and a conductor wiring layer provided on both ends of the through conductor facing each other in the thickness direction; the sealing material has, in the thickness direction, a first sealing portion covering one surface of each of the core substrate and the capacitor component, and a second sealing portion covering the other surface of each of the core substrate and the capacitor component, a distance in the thickness direction from a surface of the conductor wiring layer on the first sealing portion side to a surface of the sealing material on the first sealing portion side is larger than a distance from a surface of the conductor wiring layer on the second sealing portion side to a surface of the sealing material on the second sealing portion side, the diameter of the through hole at the end on the first sealing portion side is larger than the diameter of the through hole at the end on the second sealing portion side.

2. The capacitor-embedded substrate according to claim 1 , wherein a diameter of the through hole that passes through the capacitor body is smaller than a diameter of an end of the through hole on the first sealing portion side.

3. 3. The capacitor-embedded substrate according to claim 2, wherein a diameter of the portion of the through hole that penetrates the capacitor body is smaller than a diameter of an end of the through hole on the first sealing portion side and a diameter of an end of the through hole on the second sealing portion side.

4. 4. The capacitor-embedded substrate according to claim 1, wherein the linear expansion coefficient of the base material in a plane direction perpendicular to the thickness direction is 80% or more and 120% or less of the linear expansion coefficient of the sealing material in the plane direction.

5. 4. The capacitor-embedded substrate according to claim 1, wherein a linear expansion coefficient of said core in a plane direction perpendicular to said thickness direction is greater than 120% of a linear expansion coefficient of said sealing material in said plane direction.

6. 4. The capacitor-embedded substrate according to claim 1, wherein the linear expansion coefficient of the core in a surface direction perpendicular to the thickness direction is 80% or more and 120% or less of the linear expansion coefficient of the sealing material in the surface direction.

7. The capacitor-embedded substrate according to any one of claims 1 to 3, wherein the capacitor component further has a protective layer covering at least a portion of at least one of a surface of the conductor wiring layer on the first sealing portion side and a surface on the second sealing portion side.

8. 8. The capacitor-embedded substrate according to claim 7, wherein a linear expansion coefficient of the protective layer in a plane direction perpendicular to the thickness direction is 80% or more and 120% or less of a linear expansion coefficient of the core portion in the plane direction.

9. 9. The capacitor-embedded substrate according to claim 8, wherein a linear expansion coefficient of the protective layer in the planar direction is greater than 120% of a linear expansion coefficient of the sealing material in the planar direction.

10. 9. The capacitor-embedded substrate according to claim 8, wherein a linear expansion coefficient of the protective layer in the planar direction is greater than 120% of a linear expansion coefficient of the base material in the planar direction.

11. The protective layer has an opening in the thickness direction. The capacitor-embedded substrate according to claim 7 , wherein the opening in the protective layer is filled with the sealing material.

12. The capacitor-embedded substrate according to any one of claims 1 to 3, wherein the core substrate further has an electrode provided on at least one of the surfaces of the base material facing the first sealing portion and the surface facing the second sealing portion.

13. the anode layer has the core portion and a porous portion provided on at least one of both surfaces of the core portion facing each other in the thickness direction, the dielectric layer is provided on a surface of the porous portion, 4. The capacitor-embedded substrate according to claim 1, wherein the cathode layer is provided on a surface of the dielectric layer.