Capacitor

Abstract

A capacitor (1A) is provided with: an insulating substrate (10) having a main surface (10a); a capacitance forming section (20) provided on the main surface (10a); and a first external connection wire and a second external connection wire connected to the capacitance forming unit (20). The capacitance forming portion (20) includes a conductive metal porous body (21) connected to the first external connection wiring, a dielectric film (22) covering a surface of the metal porous body (21), and a conductive film (23) covering the dielectric film (22) and connected to the second external connection wiring. The second external connection wiring includes a conductive plated portion (50) provided on an outer peripheral portion (20a) of the capacitance forming portion (20), and a conductive intervening film (40) interposed between the capacitance forming portion (20) and the plated portion (50). The capacitance forming part (20) is sealed by the insulating substrate (10) and the plated part (50).

Description

Technical Field

[0001] The present invention relates to capacitors. Background Art

[0002] For example, International Publication No. 2018 / 092722 (Patent Document 1) discloses a capacitor having a capacitance-forming portion formed by a porous metal body, a dielectric film covering the surface of the porous metal body, and a conductive film covering the dielectric film. In this capacitor, the capacitance-forming portion is sealed with a conductive plating portion.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 092722 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Here, for the capacitor disclosed in the above-mentioned patent document 1, the plating solution for forming the plating portion sometimes remains in a plurality of fine spaces inside the capacitor forming portion. In this case, due to the heat load applied during the manufacture of the capacitor or after installation, the plating solution expands and generates bubbles, thereby possibly causing cracks in the dielectric film by applying stress to the capacitor forming portion. In addition, the porous metal body may also be dissolved by contact of the residue of the plating solution with the porous metal body.

[0008] When cracks are formed in the dielectric film or the porous metal body is dissolved, a short circuit occurs in the capacitance forming portion, resulting in a decrease in the function of the capacitor.

[0009] Therefore, the present invention is completed to solve the above-mentioned problems, and its purpose is to achieve improved reliability after mounting in a capacitor having a capacitor forming part including a metal porous body, a dielectric film and a conductive film, and a plating part that seals the capacitor forming part.

[0010] Technical solutions to solve problems

[0011] The capacitor according to the present invention comprises: an insulating substrate having a main surface; a capacitor forming portion provided on the main surface; and a first external connection wiring and a second external connection wiring connected to the capacitor forming portion. The capacitor forming portion comprises a conductive metal porous body connected to the first external connection wiring, a dielectric film covering the surface of the metal porous body, and a conductive film covering the dielectric film and connected to the second external connection wiring. The second external connection wiring comprises a conductive plating portion provided on the outer periphery of the capacitor forming portion, and a conductive intervening film between the capacitor forming portion and the plating portion. The capacitor forming portion is sealed by the insulating substrate and the plating portion.

[0012] Effects of the Invention

[0013] According to the present invention, in a capacitor including a capacitance-forming portion including a porous metal body, a dielectric film, and a conductive film, and a plated portion sealing the capacitance-forming portion, it is possible to achieve improved reliability after mounting. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic front view of the capacitor according to the first embodiment.

[0015] Figure 2 yes Figure 1 A schematic bottom view of the capacitor is shown.

[0016] Figure 3 yes Figure 2 A schematic cross-sectional view of a capacitor is shown.

[0017] Figure 4 yes Figure 3 An enlarged cross-sectional view of the main parts of the capacitor is shown.

[0018] Figure 5 This is an enlarged cross-sectional view of a main part for explaining an example of a distance measurement method.

[0019] Figure 6 This is a flowchart showing a method for manufacturing a capacitor according to the first embodiment.

[0020] Figure 7 It shows Figure 6 Schematic cross-sectional view of the state after step S4 of the manufacturing process is completed.

[0021] Figure 8 Is used to illustrate Figure 6 Schematic cross-sectional view of step S5 of the manufacturing process is shown.

[0022] Figure 9 Is used to illustrate Figure 6 Schematic cross-sectional view of step S6 of the manufacturing process is shown.

[0023] Figure 10 Is used to illustrate Figure 6 Schematic cross-sectional view of step S7 of the manufacturing process is shown.

[0024] Figure 11 Is used to illustrate Figure 6 Schematic cross-sectional view of step S8 of the manufacturing process is shown.

[0025] Figure 12 Is used to illustrate Figure 6 Schematic cross-sectional view of step S9 of the manufacturing process is shown.

[0026] Figure 13 is a schematic cross-sectional view of a capacitor according to a first modification.

[0027] Figure 14 is a schematic cross-sectional view of a capacitor according to a second modification.

[0028] Figure 15 This is a schematic cross-sectional view of a capacitor according to the second embodiment.

[0029] Figure 16 yes Figure 15 An enlarged cross-sectional view of the main parts of the capacitor is shown.

[0030] Figure 17 This is a flowchart showing a method for manufacturing a capacitor according to the second embodiment. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present invention in detail with reference to the accompanying drawings. It should be noted that in the embodiments shown below, identical or common parts are denoted by the same reference numerals in the figures, and their descriptions will not be repeated. Furthermore, in the embodiments shown below, the terms "anode" and "cathode" are used for convenience of description. However, the electrical polarity of the capacitors in the embodiments shown below is not solely determined by these terms; rather, the electrical polarity is appropriately determined in accordance with the environment in which the capacitors are used.

[0032] (Implementation Method 1)

[0033] Figure 1 This is a schematic front view of the capacitor according to the first embodiment. Figure 2 It is from Figure 1 Schematic bottom view of the capacitor viewed in the direction of arrow II shown in FIG. Figure 3 It is along Figure 2 A schematic cross-sectional view of a capacitor with III-III lines is shown in FIG. Figure 4 yes Figure 3 An enlarged cross-sectional view of a main portion of region IV in the capacitor is shown. Figure 5This is an enlarged cross-sectional view of a main part for explaining an example of a distance measurement method. Figures 1 to 5 , the structure of the capacitor 1A involved in this embodiment is described. It should be noted that, Figure 5 The area shown is Figure 4 The areas shown are the same.

[0034] like Figures 1 to 4 As shown, capacitor 1A has a flat, generally rectangular parallelepiped shape, with its bottom surface serving as a mounting surface for a wiring substrate, etc. Capacitor 1A primarily comprises an insulating substrate 10, a capacitance-forming portion 20, and a plated portion 50. Capacitor-forming portion 20 is disposed opposite insulating substrate 10. Capacitor-forming portion 20 is located within capacitor 1A by being sealed by insulating substrate 10 and a portion of plated portion 50 disposed on insulating substrate 10.

[0035] Insulating substrate 10 is provided with a first via-hole conductor 13 and a first bump 16. First via-hole conductor 13 and first bump 16 constitute one of a pair of external connection wirings for electrically connecting capacitance-forming portion 20 located within capacitor 1A to an external circuit. More specifically, the pair of external connection wirings includes a first external connection wiring serving as an anode and a second external connection wiring serving as a cathode. The first external connection wiring is comprised of first via-hole conductor 13 and first bump 16. The second external connection wiring is comprised of, for example, plated portion 50, though this will be described in detail later.

[0036] The insulating substrate 10 comprises a flat plate-shaped member having a first principal surface 10a as a main surface and a second principal surface 10b located opposite the first principal surface 10a. The insulating substrate 10 is preferably an electrically insulating substrate, preferably one primarily composed of an inorganic material. More specifically, the insulating substrate 10 may be composed primarily of, for example, Si, Al2O3, ZrO2, BN, Si3N4, AlN, MgO, Mg2SiO4, BaTiO3, SrTiO3, or CaTiO3.

[0037] The thickness and size of the insulating substrate 10 are not particularly limited, but for example, an alumina substrate having a thickness of 5 μm to 75 μm and a side length of 500 μm to 2000 μm in a plan view rectangular shape is preferably used.

[0038] The insulating substrate 10 is provided with a first through hole 11. The first through hole 11 penetrates the insulating substrate 10 from the first main surface 10a to the second main surface 10b. The first through hole 11 is filled with a first via-hole conductor 13. The shape of the first via-hole conductor 13 is, for example, substantially cylindrical.

[0039] The first via-hole conductor 13 constitutes a portion of the first external connection wiring and is provided in a region where the capacitance forming portion 20 is arranged, when viewed along the normal direction of the first main surface 10 a of the insulating substrate 10 .

[0040] The first via-hole conductor 13 can be formed from a variety of wiring materials, but is particularly preferably formed from a metal material with high electrical conductivity. The material of the first via-hole conductor 13 can be, for example, a metal material primarily composed of any of Ni, Ag, Cu, Au, Pt, Mo, and W. The material of the first via-hole conductor 13 can be appropriately modified to suit the installation environment of the capacitor 1A according to this embodiment. In this embodiment, a via-hole conductor made of Ni is used as the first via-hole conductor 13.

[0041] The axial length and size of the first via-hole conductor 13 are not particularly limited and can be appropriately set based on the thickness and size of the insulating substrate 10. The axial length of the first via-hole conductor 13 is preferably, for example, 5 μm to 75 μm, and the diameter is preferably, for example, 15 μm to 150 μm. In this embodiment, a via-hole conductor made of Ni with an axial length of 75 μm and a diameter of 150 μm is used as the first via-hole conductor 13.

[0042] A first protrusion 16 is provided on the second principal surface 10b of the insulating substrate 10 so as to cover the first via-hole conductor 13. First protrusion 16 serves as a bonding material for mounting capacitor 1A on a wiring substrate, etc., and for electrically connecting capacitance-forming portion 20 of capacitor 1A to an external circuit. First protrusion 16 is provided so as to protrude from the second principal surface 10b of the insulating substrate 10. First protrusion 16 is substantially hemispherical in shape. First protrusion 16 constitutes a portion of the aforementioned first external connection wiring.

[0043] The first bumps 16 can be made of various wiring materials, but are particularly preferably made of a metal material with high electrical conductivity. For example, the first bumps 16 can be made of a metal material primarily composed of Ni, Ag, Cu, Au, or Sn. In this embodiment, the first bumps 16 are made of Au.

[0044] The size of the first protrusion 16 is not particularly limited and can be appropriately set according to the size of the first via-hole conductor 13 .

[0045] like Figure 3As shown, the capacitor forming portion 20 is provided on the first main surface 10a of the insulating substrate 10. The capacitor forming portion 20 includes a conductive metal porous body 21 having a plurality of micropores therein, a dielectric film 22 covering the surface of the metal porous body 21, and a conductive film 23 further covering the surface of the dielectric film 22.

[0046] The porous metal body 21 is connected to the first via-hole conductor 13. In the porous metal body 21, at least a portion of the plurality of micropores provided therein is not closed by the porous metal body 21 itself. Preferably, most or all of the plurality of micropores provided therein are not closed by the porous metal body 21 itself. Such a porous metal body 21 is composed of, for example, a sintered body of metal particles.

[0047] The porous metal body 21 can be made of various conductive metal materials, but is preferably made of a metal material containing any one of Ni, Mo, W, Al, Ti, Ta, Nb, Cu, Pt, Au, and Ag as a main component. Alternatively, the porous metal body 21 may be made of an alloy material containing two or more of these metal materials as main components.

[0048] The thickness and size of the porous metal body 21 are not particularly limited, and in particular, the size is appropriately set according to the size of the insulating substrate 10. In this embodiment, the porous metal body 21 is made of Ni and has a thickness of 200 μm.

[0049] The porous metal body 21 is preferably composed of a sintered body of metal particles. In this case, the metal particles can be spherical, ellipsoidal, flat, plate-like, needle-like, or other various shapes. The particle size of the metal particles is not particularly limited, but the average particle size is preferably 600 nm or less, and more preferably 20 nm or more and 500 nm or less.

[0050] As described above, the dielectric film 22 covers the surface of the porous metal body 21. More specifically, the dielectric film 22 covers not only the surface of the porous metal body 21 located on the outermost side of the capacitance-forming portion 20, but also the surface of the porous metal body 21 located within the capacitance-forming portion 20, defined by the aforementioned micropores that are not enclosed by the porous metal body itself. Furthermore, the dielectric film 22 covers the side surfaces of the insulating substrate 10 and the edge of the second principal surface 10b.

[0051] The dielectric film 22 can be made of various insulating materials, but can be made of, for example, AlO. x 、SiO x , HfO x 、TiO x 、TaOx 、ZrO x 、SiAlO x 、HfAlO x 、ZrAlO x 、AlTiO x 、SrTiO x 、HfSiO x 、ZrSiO x 、TiZrO x 、TiZrWO x 、BaTiO x 、PbTiO x 、BaSrTiO x 、BaCaTiO x Other metal oxides, AlN x 、SiN x 、AlScN x Other metal nitrides, AlO x N y 、SiO x N y , HfO x N y 、SiC x O y N z The dielectric film 22 is made of metal oxynitrides such as AlO. x (such as Al2O3), SiO x (such as SiO2), HfO x 、TiO x 、SiAlO x 、HfAlO x 、ZrAlO x 、HfSiO x and ZrSiO x The dielectric film 22 may be formed by any of the following: (a) , (b) , (c) , (d) , (e) , (f) , (g) , (h) , (h) , (h) , (h) , (i) , (j ...

[0052] The dielectric film 22 can preferably be formed by a vapor phase method such as vacuum evaporation, chemical vapor deposition (CVD), sputtering, atomic layer deposition (ALD), pulsed laser deposition (PLD), or a method using a supercritical fluid, and is particularly preferably formed by ALD.

[0053] The thickness of the dielectric film 22 is not particularly limited, but is preferably 3 nm to 100 nm, more preferably 5 nm to 50 nm. In this embodiment, a dielectric film made of AlSiO and having a thickness of approximately 20 nm is used as the dielectric film 22 .

[0054] As described above, the conductive film 23 covers the surface of the dielectric film 22. More specifically, the conductive film 23 covers not only the surface of the dielectric film 22 located at the outermost portion of the capacitance-forming portion 20, but also the surface of the dielectric film 22 located within the capacitance-forming portion 20. Furthermore, the conductive film 23 covers the surface of the dielectric film 22 in the portion that covers the side surface of the insulating substrate 10 and the surface of the dielectric film 22 in the portion that covers the edge of the second main surface 10b.

[0055] The conductive film 23 can be made of various conductive materials, but can be made of a metal material with any one of Ni, Cu, Ru, Al, W, Ti, Ag, Au, Zn, Ta and Nb as the main material, an alloy material with two or more selected from these metal materials as the main components, metal nitrides such as TiN, TiAlN, TiSiN, TaN, NbN, WN, metal oxynitrides such as TiON, TiAlON, PEDOT (poly (3,4-ethylenedioxythiophene)), polypyrrole, polyaniline and other conductive polymers, RuO2, ZnO, (Zn, Al)O, NiO and other conductive oxide films.

[0056] The conductive film 23 can preferably be formed by CVD, ALD, PLD, plating, bias sputtering, sol-gel, a method using conductive polymer filling, or a method using a supercritical fluid, and is particularly preferably formed by ALD. Alternatively, the conductive film 23 may be formed by a laminated film including multiple conductive layers made of different materials. In this case, film formation can be performed by ALD followed by other methods.

[0057] The thickness of the conductive film 23 is not particularly limited, but is preferably 3 nm or more, more preferably 10 nm or more. In this embodiment, a conductive film made of TiN and having a thickness of approximately 25 nm is used as the conductive film 23 .

[0058] like Figure 3 and Figure 4 As shown in FIG. 4 , the outer periphery 20a of the capacitor forming portion 20 is covered by a conductive intervening film 40. More specifically, the intervening film 40 includes an outer portion 41 that does not enter the internal space of the capacitor forming portion 20 and is located between the conductive film 23 and the plated portion 50, which defines the outer periphery 20a of the capacitor forming portion 20. Thus, the intervening film 40 is interposed between the capacitor forming portion 20 and the plated portion 50. Here, the "outer periphery of the capacitor forming portion" refers to the portion surrounding the outer side of the capacitor forming portion, and thus, the shape of the capacitor forming portion is not limited to, for example, a cylindrical shape or a spherical shape.

[0059] The intervening film 40 further includes an inner portion 42 located at a position entering the inner space of the capacitance forming portion 20 .

[0060] By configuring the intervening film 40 in this manner, it is possible to effectively suppress the occurrence of a short circuit in the capacitance forming portion 20 , although details will be described later.

[0061] The distance between the portion of the outer portion 41 of the intervening film 40 that contacts the plated portion 50 and the outer peripheral portion 20a of the capacitor forming portion 20 in the thickness direction of the intervening film 40 (see Figure 4 The distance d1) in the embodiment is preferably 100 nm or more.

[0062] On the other hand, the distance between the portion of the inner portion 42 of the intervening film 40 that most deeply penetrates into the internal space of the capacitance forming portion 20 and the outer peripheral portion 20a of the capacitance forming portion 20 in the thickness direction of the intervening film 40 (see Figure 4 The distance d2 in the figure is preferably 15 μm or less. This is because if the distance is considerably large, the film stress generated in the intervening film 40 increases, and this may cause the capacitance forming portion 20 to peel from the insulating substrate 10 .

[0063] The intervening film 40 can be made of various conductive materials, but can be made of a metal material primarily composed of any one of Ni, Cu, Ru, Al, W, Ti, Ag, Au, Zn, Ta, and Nb; an alloy material primarily composed of two or more selected from these metal materials; metal nitrides such as TiN, TiAlN, TiSiN, TaN, NbN, and WN; metal oxynitrides such as TiON and TiAlON; conductive polymers such as PEDOT (poly(3,4-ethylenedioxythiophene)), polypyrrole, and polyaniline; and conductive oxide films such as RuO2, ZnO, (Zn,Al)O, and NiO. In this embodiment, an intervening film made of Cu is used as the intervening film 40.

[0064] The intervening film 40 can be preferably formed by CVD, ALD, PLD, bias sputtering, sol-gel, a method using conductive polymer filling, or a method using supercritical fluid, and is particularly preferably formed by CVD.

[0065] It should be noted that the distances d1 and d2 are measured by observing a cross section perpendicular to the extending direction of the first main surface 10a of the insulating substrate 10 using a scanning ion microscope (SIM). Figure 5 The method for measuring the distance d1 is described by way of example. It should be noted that the method for measuring the distance d2 can be performed using a method similar to the method for measuring the distance d1.

[0066] When viewing capacitor 1A from above, let the longitudinal direction of capacitor 1A be Lx, the transverse direction be Ly, and the thickness direction of capacitor 1A (i.e., the normal direction of first principal surface 10a) be Lz. First, capacitor 1A is polished to expose the Lx-Lz cross section of capacitor 1A at the center portion in the Ly direction. This polishing is performed so that the exposed cross section is within an error range of ±100 μm in the Ly direction relative to the center position.

[0067] Next, the portion near the outer periphery 20a of the capacitor forming portion 20 in the exposed cross section was observed using SIM at a magnification of 50000. The observation range in the Lz direction of the cross section was ±50 μm with respect to the center position of the cross section in the Lz direction.

[0068] Next, within the cross-sectional observation range, the distance between the portion of the outer portion 41 of the intervening film 40 that contacts the plated portion 50 and the outer peripheral portion 20a of the capacitor-forming portion 20 in the thickness direction of the intervening film 40 was measured at 10 locations at equal intervals in the Lz direction. It should be noted that when measuring these 10 locations, the distance between adjacent measurement locations in the Lz direction was set to be at least 200 nm.

[0069] Next, the average value of the total 6 measurement values ​​excluding the maximum and second largest values ​​and the minimum and second smallest values ​​among the 10 measurement values ​​obtained in this way is calculated. The average value calculated in this way becomes the above-mentioned distance d1. Here, Figure 5 In FIG, three of the distances measured at the ten locations are exemplified as line segment lengths da, db, and dc.

[0070] In addition, although the above-mentioned measurement position is determined based on the SIM image, the length can also be measured based on an image with a magnification of 200,000 times using a transmission electron microscope (TEM).

[0071] like Figures 1 to 3 As shown, the plated portion 50 is arranged on the peripheral portion 20a of the capacitor forming portion 20. Thus, the capacitor forming portion 20 is sealed by the insulating substrate 10 and the plated portion 50. The plated portion 50 specifies an outer surface 50a that is located on the side opposite to the insulating substrate 10 side when viewed from the capacitor forming portion 20. In more detail, the plated portion 50 is located at a position covering the top and side of the capacitor forming portion 20 that is opposite to the first main surface 10a of the insulating substrate 10. It should be noted that, as mentioned above, the intervention film 40 is between the capacitor forming portion 20 and the plated portion 50.

[0072] The plated portion 50 is also provided on the side surface of the insulating substrate 10 and on a portion of the second principal surface 10b. More specifically, the plated portion 50 is provided to cover a majority of the surface of the conductive film 23 located on the side surface of the insulating substrate 10 and on the edge of the second principal surface 10b. In the capacitor 1A according to this embodiment, the capacitor 1A is configured so that electrical extraction of the capacitance-forming portion 20 can be performed from the plated portion 50 formed in an annular shape along the edge of the second principal surface 10b of the insulating substrate 10.

[0073] That is, in this embodiment, the bottom surface of capacitor 1A is defined by first protrusion 16 and plated portion 50 formed as an annular portion along the edge of second main surface 10b of insulating substrate 10, thereby constituting a mounting surface for a wiring board or the like.

[0074] The plated portion 50 can be formed of various conductive materials, but is particularly preferably formed of a metal material with high electrical conductivity. The material of the plated portion 50 can be, for example, a metal material primarily composed of any one of Ni, Ag, Cu, Au, Pt, Mo, and W. In this embodiment, a plated portion composed of Cu is used as the plated portion 50. The plated portion 50 can be formed using various plating methods.

[0075] The thickness and size of the plated portion 50 are not particularly limited and can be appropriately set depending on the size of the insulating substrate 10. The plated portion 50 preferably has a thickness of, for example, 0.5 μm to 50 μm, and a size such that it covers the entire first principal surface 10 a of the insulating substrate 10.

[0076] The second external connection wiring, which is the other of a pair of external connection wirings for electrically connecting the capacitance forming portion 20 to an external circuit, is formed by the above-described interposer film 40 and the plated portion 50 .

[0077] With the above structure, capacitor 1A according to this embodiment electrically extracts capacitance-forming portion 20, which includes conductive porous metal body 21, dielectric film 22, and conductive film 23, via a pair of external connection wiring. More specifically, in capacitor 1A, the first external connection wiring includes first via-hole conductor 13 and first bump 16, connecting porous metal body 21 in capacitance-forming portion 20 to first via-hole conductor 13. Furthermore, in capacitor 1A, the second external connection wiring includes intervening film 40 and plated portion 50, connecting conductive film 23 in capacitance-forming portion 20 to plated portion 50 via intervening film 40.

[0078] Figure 6 1 is a flowchart illustrating a method for manufacturing a capacitor according to this embodiment. Figures 7 to 12 They are used to illustrate Figure 6 Schematic cross-sectional view of each step of the manufacturing process shown. Figures 6 to 12 An example of a specific manufacturing method for manufacturing the capacitor 1A according to the present embodiment described above will be described.

[0079] When manufacturing the capacitor 1A according to this embodiment, first, Figure 6 As shown, in step S1, a green sheet is produced. Specifically, Al2O3 powder and glass powder are weighed and mixed with an organic solvent such as toluene or ethanol, and a binder such as polyvinyl butyral. This mixture is then formed into a sheet, thereby producing a green sheet that will serve as the basis for the insulating substrate.

[0080] Then, if Figure 6As shown, in step S2, a first through hole is formed in the green sheet. Specifically, a first through hole 11, which will be filled with a first via-hole conductor 13, which will later serve as a part of the anode, is provided at a predetermined position in the green sheet.

[0081] Here, the method for forming the first through-holes 11 is not particularly limited, but for example, the first through-holes 11 can be formed by irradiating a green sheet with laser light. Alternatively, the first through-holes 11 can be formed by machining using a mechanical punch or sandblasting.

[0082] Then, if Figure 6 As shown, in step S3 , a first via conductor is formed on the green sheet in which the first through hole is formed. Specifically, a conductive paste is applied to the green sheet so as to fill the first through hole 11 .

[0083] Here, the method of applying the conductive paste is not particularly limited, but for example, a screen printing method can be used.

[0084] Then, if Figure 6 As shown, in step S4, the green sheet coated with the conductive paste is fired. The firing of the green sheet is performed, for example, at a temperature of 700° C. to 1000° C. in an air atmosphere.

[0085] After the above steps S1 to S4, Figure 7 Insulating substrate as shown.

[0086] While the above description illustrates the simultaneous firing of the green sheet and the conductive paste, the first via conductors 13 may be formed after firing the insulating substrate, which does not have the first through-holes or the like. In this case, the first through-holes 11 may be formed in the fired insulating substrate by, for example, sandblasting, wet etching, dry etching, or the like, followed by further application of the conductive paste and firing. Alternatively, the first via conductors 13 may be formed by sputtering, vapor deposition, plating, or the like.

[0087] Then, if Figure 6 and Figure 8 As shown, in step S5, a porous metal body is formed. Figure 8 As shown, a porous metal body 21 is formed on the first main surface 10 a of the insulating substrate 10 .

[0088] More specifically, conductive metal particles, an organic solvent such as terpineol, and a varnish of ethyl cellulose are weighed and mixed. A conductive paste is prepared using this mixture using a roller press. The thus-prepared conductive paste is applied to the first main surface 10a of the insulating substrate 10 and dried.

[0089] At this time, the conductive paste is applied in multiple layers, overlapping each other, to a predetermined thickness on first main surface 10a. The conductive paste is applied in a pattern that has an overall rectangular shape when viewed from above. Each layer of conductive paste applied to first main surface 10a forms the aforementioned porous metal body 21.

[0090] Next, the insulating substrate 10 coated with the conductive paste is degreased, and then the conductive paste is fired at a temperature of 400° C. to 900° C., for example, in a reducing atmosphere containing a mixture of nitrogen and hydrogen. This causes adjacent metal particles contained in the conductive paste to form necks, resulting in the formation of a porous metal body 21.

[0091] The atmosphere during firing is preferably a reducing atmosphere as described above, but can be set to an atmosphere equal to or lower than the equilibrium oxygen partial pressure of the metal selected as the main component of the porous metal body 21 .

[0092] Then, if Figure 6 and Figure 9 As shown in FIG. 5 , in step S6, a dielectric film is formed. Figure 9 As shown, the dielectric film 22 is formed so as to cover the first main surface 10 a , the side surfaces and the edge portion of the second main surface 10 b of the insulating substrate 10 , and the surface of the porous metal body 21 .

[0093] The method for forming the dielectric film 22 is not particularly limited, but the ALD method is preferably used. When the ALD method is used, the raw material of the dielectric film 22 can be supplied in the form of gas, thereby enabling the selection of materials and adjustment of film thickness at the atomic layer level.

[0094] When the dielectric film 22 is formed using the ALD method, it is preferable to use a raw material gas having the following characteristics: high vapor pressure and easy vaporization, high thermal stability, and high reactivity. From this point of view, for example, when forming AlO x In the case of a film, TMA (trimethylaluminum) is preferably used as a raw material. x In the case of a dielectric film, TDMAS (trisdimethylaminosilane) is preferably used as a raw material. In this embodiment, the dielectric film 22 composed of AlSiO is formed using the ALD method.

[0095] The dielectric film 22 is formed under a temperature condition of, for example, 150° C. or higher and 400° C. or lower, although it varies depending on the film forming method and the film forming material.

[0096] Then, if Figure 6 and Figure 10As shown in FIG. 1 , in step S7 , a conductive film is formed. More specifically, the conductive film 23 is formed so as to cover the dielectric film 22 formed in step S6 .

[0097] The method for forming the conductive film 23 is not particularly limited, but the ALD method is preferably used. Using the ALD method allows the raw material for the conductive film 23 to be supplied in the form of a gas, enabling the selection of materials and adjustment of the film thickness at the atomic layer level. It should be noted that while the formation of the conductive film 23 varies depending on the film formation method and film forming material, it is performed, for example, at a temperature of 150°C to 600°C. In this embodiment, the conductive film 23 is formed of TiN using the ALD method.

[0098] After the above steps S5 to S7, Figure 10 As shown, a capacitor forming portion 20 including a conductive porous metal body 21 , a dielectric film 22 , and a conductive film 23 is formed on a first main surface 10 a of an insulating substrate 10 .

[0099] Then, if Figure 6 and Figure 11 Specifically, the intervening film 40 is formed so as to cover the surface of the conductive film 23 defining the outer periphery 20 a of the capacitance forming portion 20 and to be positioned so as to enter the internal space of the capacitance forming portion 20 .

[0100] The method for forming the intervening film 40 is not particularly limited, but CVD is preferably used. In this embodiment, the intervening film 40 made of Cu is formed using CVD.

[0101] Then, in Figure 6 and Figure 12 In step S9, a plated portion is formed. Specifically, a plated portion 50 is formed on the first main surface 10a of the insulating substrate 10 on which the capacitor forming portion 20 is provided, so as to cover the capacitor forming portion 20. In addition, the plated portion 50 is formed to cover the surface of the conductive film 23 located on the side surface of the insulating substrate 10 and the majority of the surface of the conductive film 23 located on the edge of the second main surface 10b. The plated portion 50 is formed by any of various plating methods such as electrolytic plating.

[0102] By forming the plated portion 50 in this manner, the capacitor forming portion 20 is sealed by the insulating substrate 10 and the plated portion 50. As a result, it is possible to prevent moisture from intruding from the outside into the capacitor forming portion 20, thereby ensuring moisture resistance. In addition, the capacitor forming portion 20 is covered by the plated portion 50, and the capacitor forming portion 20 is also physically protected by the plated portion 50.

[0103] Then, if Figure 6As shown, in step S10, a first protrusion is formed on the insulating substrate. Figure 3 As shown, the first protrusion 16 is formed on the second main surface 10 b of the insulating substrate 10 so as to cover the first via-hole conductor 13 provided on the insulating substrate 10 .

[0104] First protrusions 16 can be formed, for example, by electroplating. In this case, a UV-curable resin film (not shown) is used as a mask to cover the portion of first via-hole conductor 13 except for the portion near the exposed portion. Electroplating is then performed in this state, thereby forming first protrusions 16 projecting from second main surface 10b. It should be noted that the UV-curable resin film, which serves as a mask, is removed after the electroplating is completed.

[0105] It should be noted that the first protrusions 16 can be formed not only by the electrolytic plating method described above, but also by a combination of methods such as screen printing, inkjet printing, and dispenser printing using a conductive paste and firing. Furthermore, the first protrusions 16 can be formed, for example, after the green sheet has been fired (step S4).

[0106] Capacitor 1A according to the first embodiment is manufactured through steps S1 to S10 described above.

[0107] Here, in a capacitor including a capacitance-forming portion 20 and a plated portion 50 that seals the capacitance-forming portion 20, as in the capacitor 1A according to the present embodiment, the plating solution used to form the plated portion 50 may remain in the numerous minute spaces provided within the capacitance-forming portion 20. Thus, if the plating solution remains in the spaces within the capacitance-forming portion 20, the function of the capacitor 1A may be impaired.

[0108] In this regard, in the capacitor 1A according to the present embodiment, as described above, the conductive intervening film 40 is interposed between the capacitance forming portion 20 and the plated portion 50 .

[0109] With this configuration, when forming the plated portion 50 in the manufacturing process of the capacitor 1A, the intervening film 40 serves as a physical barrier, thereby effectively suppressing the intrusion of the plating solution into the internal space of the capacitance-forming portion 20 .

[0110] Therefore, it is possible to prevent the plating liquid from remaining in the internal space of the capacitor-forming portion 20, causing the capacitor-forming portion 20 to peel off from the insulating substrate 10, or the porous metal body 21 to melt, thereby causing a short circuit in the capacitor-forming portion 20. As a result, it is possible to achieve capacitor 1A that suppresses the impairment of the capacitor function due to such a short circuit and achieves improved reliability after mounting.

[0111] Therefore, capacitor 1A according to this embodiment achieves improved reliability after mounting in a capacitor including a capacitance-forming portion including a porous metal body, a dielectric film, and a conductive film, and a plated portion sealing the capacitance-forming portion.

[0112] Furthermore, in the capacitor 1A according to the present embodiment, as described above, the intervening film 40 includes not only the outer portion 41 located between the outer peripheral portion 20a of the capacitance-forming portion 20 and the plated portion 50 but also the inner portion 42 located within the interior space of the capacitance-forming portion 20. This makes it possible to more effectively suppress the intrusion of the plating solution into the interior space of the capacitance-forming portion 20.

[0113] Furthermore, in the capacitor 1A according to this embodiment, as described above, the distance between the portion of the outer portion 41 of the intervening film 40 that contacts the plated portion 50 and the outer peripheral portion 20a of the capacitance-forming portion 20 in the thickness direction of the intervening film 40 is preferably 100 nm or greater. This configuration can more reliably prevent the plating solution from invading the internal space of the capacitance-forming portion 20.

[0114] Furthermore, in capacitor 1A according to this embodiment, as described above, the distance between the portion of inner portion 42 of intervening film 40 that most deeply penetrates the internal space of capacitance-forming portion 20 in the thickness direction of intervening film 40 and outer peripheral portion 20a of capacitance-forming portion 20 is preferably 15 μm or less. This configuration further reliably prevents separation of capacitance-forming portion 20 from insulating substrate 10 due to film stress generated in intervening film 40, thereby achieving improved reliability after mounting.

[0115] It should be noted that, in the capacitor 1A involved in the above-mentioned present embodiment, the case where the electrical lead-out of the capacitor forming portion 20 is performed from the plating portion 50 formed as a ring-shaped portion along the edge of the second main surface 10b of the insulating substrate 10 is illustrated, but the electrical lead-out of the capacitor forming portion 20 can also be performed from the outer surface 50a of the plating portion 50, or from the plating portion 50 that defines the side surface of the capacitor 1A.

[0116] Thus, by providing the plated portion 50 that seals the capacitance forming portion 20 as in the capacitor 1A according to the present embodiment, the degree of freedom in setting the direction in which the electricity from the capacitance forming portion 20 is drawn out can be significantly improved.

[0117] (First Modification)

[0118] Figure 13 1 is a schematic cross-sectional view of a capacitor according to a first modification. Figure 13 , a capacitor 1A1 according to a first modified example of the first embodiment described above will be described.

[0119] like Figure 13 As shown, the capacitor 1A1 according to the first modification example differs from the capacitor 1A according to the first embodiment in the structures of the dielectric film 22 , the conductive film 23 , and the plated portion 50 .

[0120] More specifically, in the capacitor 1A1 according to this modification, the dielectric film 22 , the conductive film 23 , and the plated portion 50 are not provided on any of the side surfaces and the second main surface 10 b of the insulating substrate 10 .

[0121] Therefore, for capacitor 1A1, the electrical lead of capacitance-forming portion 20 is made from first protrusion 16 and outer surface 50a of plated portion 50. Alternatively, for capacitor 1A1, the electrical lead of capacitance-forming portion 20 can be made from first protrusion 16 and a portion of plated portion 50 defining the side surface of capacitor 1A1. That is, in capacitor 1A1, the bottom and top surfaces of capacitor 1A1 constitute the mounting surfaces for a wiring substrate, etc., or the bottom and side surfaces of capacitor 1A1 constitute the mounting surfaces for a wiring substrate, etc.

[0122] Even in the case of such a configuration, the same effect as that described in the above-mentioned embodiment 1 is obtained, and in a capacitor having a capacitor-forming portion including a metal porous body, a dielectric film, and a conductive film, and a plating portion that seals the capacitor-forming portion, improved reliability after installation is achieved.

[0123] Note that the method for manufacturing the capacitor 1A1 according to the first modification can basically be manufactured according to the method for manufacturing the capacitor 1A according to the first embodiment described above.

[0124] (Second Modification)

[0125] Figure 14 : is a schematic cross-sectional view of a capacitor according to a second modification. Figure 14 , a capacitor 1A2 according to a second modified example of the first embodiment will be described.

[0126] like Figure 14 As shown, the capacitor 1A2 according to the second modification example differs from the capacitor 1A according to the first embodiment in the configurations of the capacitance forming portion 20 and the second external connection wiring.

[0127] More specifically, in capacitor 1A2 according to this modification, through-hole 20c is provided in capacitance forming portion 20. Through-hole 20c penetrates capacitance forming portion 20 so as to extend from one end to the other end in the height direction of capacitance forming portion 20.

[0128] The through-hole 20c is filled with the plated portion 50. An intervening film 40 is present between the portion of the plated portion 50 filling the through-hole 20c and the portion of the capacitance forming portion 20 defining the through-hole 20c.

[0129] Furthermore, in the capacitor 1A2 according to this modification, the second external connection wiring includes, in addition to the above-described intervening film 40 and plated portion 50 , a second via conductor 14 and a second bump 17 provided on the insulating substrate 10 .

[0130] More specifically, second through-hole 12 is provided in the portion of insulating substrate 10 that overlaps with plated portion 50 filling through-hole 20c when capacitor 1A2 is viewed from above. Second through-hole 12 penetrates insulating substrate 10 from first principal surface 10a to second principal surface 10b.

[0131] The second through hole 12 is filled with a second via-hole conductor 14. The second via-hole conductor 14 is, for example, substantially cylindrical in shape. The material and shape of the second via-hole conductor 14 are, for example, the same as those of the first via-hole conductor 13 described above.

[0132] A second protrusion 17 is provided on the second principal surface 10b of the insulating substrate 10 so as to cover the second via-hole conductor 14. The second protrusion 17 is provided so as to protrude from the second principal surface 10b of the insulating substrate 10. The shape of the second protrusion 17 is substantially hemispherical. The material and shape of the second protrusion 17 are similar to those of the first protrusion 16 described above.

[0133] That is, in this modification, the bottom surface of capacitor 1A2 is defined by first protrusion 16 and second protrusion 17 , so that the bottom surface serves as a mounting surface for a wiring board or the like.

[0134] Even in the case of such a configuration, the same effect as that described in the above-mentioned embodiment 1 is obtained, and in a capacitor having a capacitor-forming portion including a metal porous body, a dielectric film, and a conductive film, and a plating portion that seals the capacitor-forming portion, improved reliability after installation is achieved.

[0135] Note that capacitor 1A2 according to the second modification can basically be manufactured by the manufacturing method of capacitor 1A according to the first embodiment described above.

[0136] As an example, the second through-hole is formed simultaneously with step S2 (forming the first through-hole). Furthermore, the second via-conductor is formed simultaneously with step S3 (forming the first via-conductor). Furthermore, after step S7 and before step S8 (after forming the conductive film and before forming the intervening film), a through-hole is provided in the capacitor-forming portion. Furthermore, in step S8, the intervening film is formed so as to also cover the portion of the capacitor-forming portion defining the through-hole. Furthermore, in step S9, the plated portion 50 is formed so as to also fill the through-hole 20 c.

[0137] By manufacturing the capacitor 1A2 as described above, the intervening film 40 also exists between the plated portion 50 filling the portion of the through-hole 20 c and the capacitance forming portion 20 defining the portion of the through-hole 20 c as described above.

[0138] (Implementation Method 2)

[0139] Figure 15 This is a schematic cross-sectional view of a capacitor according to the second embodiment. Figure 16 yes Figure 15 The main part of the region XVI in the capacitor shown is enlarged and sectional view. Figure 15 and Figure 16 , capacitor 1B according to this embodiment will be described.

[0140] like Figure 15 and Figure 16 As shown, capacitor 1B according to the present embodiment differs from capacitor 1A according to the first embodiment in the structure of capacitance forming portion 20 .

[0141] More specifically, in the capacitor 1B according to this embodiment, the capacitance-forming portion 20 further includes a hydrophobic film 24. As described in detail later, depending on its electrical properties, the hydrophobic film 24 may cover only the portion of the conductive film 23 defining the internal space of the capacitance-forming portion 20, or may also cover the portion of the conductive film 23 defining the outer periphery 20a of the capacitance-forming portion 20. In this embodiment, the insulating hydrophobic film 24 covers only the portion of the conductive film 23 defining the internal space of the capacitance-forming portion 20.

[0142] The hydrophobic film 24 may be made of an insulating material or a conductive material. In the case of an insulating hydrophobic film 24, the hydrophobic film 24 may be made of, for example, a silane coupling agent or an organic fluorine compound. In the case of a conductive hydrophobic film 24, the hydrophobic film 24 may be made of, for example, a fluorinated compound. In this embodiment, an insulating hydrophobic film 24 made of a silane coupling agent is used.

[0143] The method for forming the water-repellent film 24 is not particularly limited, but is preferably formed by an impregnation method. The thickness of the water-repellent film 24 is not particularly limited, but is preferably 10 nm or more and 1 μm or less.

[0144] Thus, when the capacitor forming portion 20 includes the hydrophobic film 24, the distance between the portion of the outer portion 41 of the intervening film 40 that contacts the plated portion 50 and the outer peripheral portion 20a of the capacitor forming portion 20 in the thickness direction (refer to Figure 4 The distance d1) can be made smaller than the distance in the case where the capacitance-forming portion 20 does not include the hydrophobic film 24, as in the capacitor 1A according to the first embodiment. This is because the hydrophobic film 24, like the intervening film 40, has the function of inhibiting the plating solution from invading the internal space of the capacitance-forming portion 20. Therefore, in this embodiment, the distance is preferably 50 nm or greater.

[0145] Figure 17 is a flowchart showing a method for manufacturing a capacitor according to Embodiment 2. Figure 17 An example of a specific manufacturing method for manufacturing the capacitor 1B according to the present embodiment will be described.

[0146] like Figure 17 As shown, most of the manufacturing method of capacitor 1B follows the manufacturing method of capacitor 1A. Therefore, the following description of the steps in the manufacturing method of capacitor 1B that are common to the manufacturing method of capacitor 1A will be omitted, and only the steps that are different from the manufacturing method of capacitor 1A will be described.

[0147] like Figure 17 As shown, after the conductive film is formed in step S8 , a hydrophobic film is formed in step S8B. More specifically, the insulating hydrophobic film 24 is formed to cover only the portion of the conductive film 23 defining the internal space of the capacitor forming portion 20 .

[0148] Here, if the hydrophobic film 24 has insulating properties, it is preferable that the hydrophobic film 24 is formed so as not to cover the portion of the conductive film 23 defining the outer periphery 20a of the capacitance forming portion 20. This is because by sequentially stacking the conductive film 23, the hydrophobic film 24, and the conductive intervening film 40, a so-called MIM (Metal Insulator Metal) structure is formed, thereby preventing the formation of an undesired capacitance forming portion in the capacitor 1B.

[0149] Therefore, in step S8B, for example, it is preferable to form the hydrophobic film 24 after masking the portion of the conductive film 23 defining the outer peripheral portion 20a of the capacitance forming portion 20, or to form the hydrophobic film 24 while controlling the penetration depth of the hydrophobic film 24 to a desired depth. In this way, the insulating hydrophobic film 24 can be formed to cover only the portion of the conductive film 23 defining the internal space of the capacitance forming portion 20.

[0150] In the capacitor 1B involved in this embodiment constructed in this way, the same effect as that described in the above-mentioned embodiment 1 is also obtained, and the reliability after installation is improved in the capacitor having a capacitor forming part including a metal porous body, a dielectric film and a conductive film and a plating part that seals the capacitor forming part.

[0151] Furthermore, in such a configuration, when the plating portion 50 is formed during the manufacturing process of the capacitor 1B, not only can the intervening film 40 serve as a physical barrier to suppress the intrusion of the plating liquid into the internal space of the capacitor forming portion 20, but the hydrophobicity of the hydrophobic film 24 can also be utilized to suppress the infiltration of the plating liquid.

[0152] It should be noted that, in the present embodiment described above, the case where the capacitance forming portion 20 includes the insulating hydrophobic film 24 is described as an example, but as described above, the hydrophobic film 24 may also have conductivity.

[0153] In this case, the hydrophobic film 24 may be formed to cover not only the portion of the conductive film 23 defining the internal space of the capacitance forming portion 20, but also the portion of the conductive film 23 defining the outer peripheral portion 20a of the capacitance forming portion 20. This is because, if the hydrophobic film 24 is conductive, the undesirable capacitance forming portion described above will not be formed in the capacitor 1B.

[0154] (Note)

[0155] The characteristic structures of the capacitors disclosed in the above-described embodiment and its modified examples are summarized as follows.

[0156] [Note 1]

[0157] A capacitor comprising:

[0158] an insulating substrate having a main surface;

[0159] a capacitance forming portion provided on the main surface; and

[0160] The first external connection wiring and the second external connection wiring are connected to the capacitor forming portion.

[0161] The capacitor forming portion includes a conductive metal porous body connected to the first external connection wiring, a dielectric film covering a surface of the metal porous body, and a conductive film covering the dielectric film and connected to the second external connection wiring.

[0162] The second external connection wiring includes a conductive plated portion provided on the periphery of the capacitor forming portion and a conductive intervening film interposed between the capacitor forming portion and the plated portion.

[0163] The capacitance forming portion is sealed by the insulating substrate and the plated portion.

[0164] [Note 2]

[0165] The capacitor according to Supplementary Note 1, wherein:

[0166] The intervening film includes an inner portion located in an inner space of the capacitance forming portion and an outer portion located between the outer peripheral portion of the capacitance forming portion and the plated portion without entering the inner space of the capacitance forming portion.

[0167] [Note 3]

[0168] The capacitor according to Supplementary Note 2, wherein:

[0169] A distance between a portion of the inner portion of the intervening film that most deeply penetrates into the internal space of the capacitance forming portion and the outer periphery of the capacitance forming portion in a thickness direction of the intervening film is 15 μm or less.

[0170] [Note 4]

[0171] The capacitor according to Supplementary Note 2 or 3, wherein:

[0172] A distance between a portion of the outer portion of the intervening film that contacts the plated portion and the outer peripheral portion of the capacitance forming portion in a thickness direction of the intervening film is 100 nm or greater.

[0173] [Note 5]

[0174] The capacitor according to Supplementary Note 2 or 3, wherein:

[0175] The capacitor forming portion further includes an insulating hydrophobic film.

[0176] The water-repellent film covers only a portion of the conductive film defining the internal space of the capacitance forming portion.

[0177] [Note 6]

[0178] The capacitor according to Supplementary Note 2 or 3, wherein:

[0179] The capacitor forming portion further includes a conductive hydrophobic film.

[0180] The hydrophobic film covers at least a portion of the conductive film defining the internal space of the capacitance forming portion.

[0181] [Note 7]

[0182] The capacitor according to Supplementary Note 5 or 6, wherein:

[0183] A distance between a portion of the outer portion of the intervening film that contacts the plated portion and the outer peripheral portion of the capacitance forming portion in a thickness direction of the intervening film is 50 nm or more.

[0184] (Other methods, etc.)

[0185] The shape, structure, size, number, material, etc. of each component shown in the above-mentioned embodiment of the present invention can be variously modified within the scope not departing from the gist of the present invention.

[0186] Furthermore, it is a matter of course that the characteristic structures shown in the above-mentioned embodiments of the present invention can be combined with each other within the scope permitted by the gist of the present invention.

[0187] Thus, the above-mentioned embodiment disclosed this time is illustrative in all aspects and is not restrictive. The technical scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope equivalent to the description of the claims.

[0188] Description of Reference Numerals

[0189] 1A, 1A1, 1A2, 1B capacitor, 10 insulating substrate, 10a first principal surface, 10b second principal surface, 11 first through-hole, 12 second through-hole, 13 first via-hole conductor, 14 second via-hole conductor, 16 first bump, 17 second bump, 20 capacitor forming portion, 20a outer peripheral portion, 20c through-hole, 21 porous metal body, 22 dielectric film, 23 conductive film, 24 hydrophobic film, 40 intervening film, 41 outer portion, 42 inner portion, 50 plated portion, 50a outer surface.

Claims

1. A capacitor comprising: an insulating substrate having a main surface; a capacitance forming portion provided on the main surface; and A first external connection wiring and a second external connection wiring are connected to the capacitor forming portion. The capacitor forming portion includes a conductive porous metal body connected to the first external connection wiring, a dielectric film covering a surface of the porous metal body, and a conductive film covering the dielectric film and connected to the second external connection wiring. The second external connection wiring includes a conductive plated portion provided on the periphery of the capacitance forming portion and a conductive intervening film interposed between the capacitance forming portion and the plated portion. The capacitance forming portion is sealed by the insulating substrate and the plated portion.

2. The capacitor according to claim 1, wherein The intervening film includes an inner portion located at a position entering the inner space of the capacitance forming portion, and an outer portion located between the outer peripheral portion of the capacitance forming portion and the plated portion without entering the inner space of the capacitance forming portion.

3. The capacitor according to claim 2, wherein A distance between a portion of the inner portion of the intervening film that most deeply penetrates into the internal space of the capacitance forming portion and the outer periphery of the capacitance forming portion in the thickness direction of the intervening film is 15 μm or less.

4. The capacitor according to claim 2 or 3, wherein: A distance between a portion of the outer portion of the intervening film that contacts the plated portion and the outer periphery of the capacitance forming portion in a thickness direction of the intervening film is 100 nm or more.

5. The capacitor according to claim 2 or 3, wherein: The capacitor forming portion further includes an insulating hydrophobic film, The water-repellent film covers only a portion of the conductive film defining the internal space of the capacitance forming portion.

6. The capacitor according to claim 2 or 3, wherein: The capacitor forming portion further includes a conductive hydrophobic film, The water-repellent film covers at least a portion of the conductive film defining the internal space of the capacitance forming portion.

7. The capacitor according to claim 5 or 6, wherein: A distance between a portion of the outer portion of the intervening film that contacts the plated portion and the outer peripheral portion of the capacitance forming portion in a thickness direction of the intervening film is 50 nm or greater.

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