Capacitor

Abstract

A capacitor (1A) is provided with an insulating substrate (10), a capacitance forming section (20), and first and second external connection wires. The insulating substrate (10) has a first main surface (10a) and a second main surface (10b) located on the opposite side from the first main surface (10a), and the capacitance forming section (20) is provided so as to face the first main surface (10a). The first external connection wiring and the second external connection wiring are connected to the capacitance forming section (20). The capacitance forming part (20) includes a conductive metal porous body (21), a dielectric film (22) covering the surface of the metal porous body (21), and a conductive film (23) covering the dielectric film (22). The conductive film (23) includes a first conductive film (23A) and second conductive films (23B-23E) that are discontinuous with each other, and the capacitance-forming section (20) includes a first capacitance-forming section (20A) and second capacitance-forming sections (20B-20E). The first capacitance forming part (20A) is defined by a first conductive film (23A), a first dielectric film (22A) which is a dielectric film (22) in a portion corresponding to the first conductive film (23A), and a first metal porous body (21A) which is a metal porous body (21) in a portion corresponding to the first dielectric film (22A). Second capacitance-forming sections (20B-20E) are defined by second conductive films (23B-23E), second dielectric films (22B-22E), which are the dielectric film (22) that correspond to the second conductive films (23B-23E), and second metal porous bodies (21B-21E), which are the metal porous bodies (21) that correspond to the second dielectric films (22B-22E). When viewed from the first capacitance forming unit (20A), the second capacitance forming units (20B-20E) are located on the opposite side from the first external connection wiring side. The second capacitance forming sections (20B-20E) are electrically connected to the first external connection wiring via the first capacitance forming section (20A), and the first capacitance forming section (20A) is electrically connected to the second external connection wiring via the second capacitance forming sections (20B-20E), whereby at least the first capacitance forming section (20A) and the second capacitance forming sections (20B-20E) are electrically connected in series between the first external connection wiring and the second external connection wiring.

Description

Technical Field

[0001] The present invention relates to a capacitor including a capacitance-forming portion including a porous metal body, a dielectric film, and a conductive film. Background Art

[0002] For example, U.S. Patent Publication No. 2018 / 0277306 (Patent Document 1) discloses a capacitor comprising 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 porous metal body is composed of a sintered body of metal particles, and both the dielectric layer and the conductive film are formed using atomic layer deposition (ALD).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: U.S. Patent Publication No. 2018 / 0277306 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Here, the capacitor disclosed in the above publication includes a single capacitance forming portion. Therefore, there is a problem that, when electric field concentration occurs in the single capacitance forming portion, the capacitor function is immediately impaired due to a short circuit.

[0008] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the reliability after mounting in a capacitor including a capacitance-forming portion including a porous metal body, a dielectric film, and a conductive film.

[0009] Technical solutions to solve problems

[0010] The capacitor according to the present invention comprises an insulating substrate, a capacitance forming portion, and first and second external connection wirings. The insulating substrate has a first main surface and a second main surface located opposite to the first main surface, and the capacitance forming portion is arranged to face the first main surface. The first and second external connection wirings are connected to the capacitance forming portion. The capacitance forming portion comprises a conductive porous metal body, a dielectric film covering the surface of the porous metal body, and a conductive film covering the dielectric film. Since the conductive film includes a first conductive film and a second conductive film that are discontinuous with each other, the capacitance-forming portion includes a first capacitance-forming portion and a second capacitance-forming portion. The first capacitance-forming portion is defined by the first conductive film, the first dielectric film as a portion of the dielectric film corresponding to the first conductive film, and the first porous metal body as a portion of the porous metal body corresponding to the first dielectric film. The second capacitance-forming portion is defined by the second conductive film, the second dielectric film as a portion of the dielectric film corresponding to the second conductive film, and the second porous metal body as a portion of the porous metal body corresponding to the second dielectric film. The second capacitance-forming portion is located on the side opposite to the first external connection wiring side when viewed from the first capacitance-forming portion. In the above-mentioned capacitor based on the present invention, the above-mentioned second capacitor forming part is electrically connected to the above-mentioned first external connection wiring via the above-mentioned first capacitor forming part, and the above-mentioned first capacitor forming part is electrically connected to the above-mentioned second external connection wiring via the above-mentioned second capacitor forming part, thereby at least the above-mentioned first capacitor forming part and the above-mentioned second capacitor forming part are electrically connected in series between the above-mentioned first external connection wiring and the above-mentioned second external connection wiring.

[0011] Effects of the Invention

[0012] 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, it is possible to achieve improved reliability after mounting. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 and 2 are a schematic front view and a schematic top view of the capacitor according to the first embodiment.

[0014] Figure 2 yes Figure 1 A schematic cross-sectional view of a capacitor is shown.

[0015] Figure 3 It will Figure 2 FIG. 2 is an enlarged schematic cross-sectional view of the vicinity of the first main surface of the insulating substrate.

[0016] Figure 4 yes Figure 2 An enlarged cross-sectional view of a main portion of region IIII is shown.

[0017] Figure 5 yes Figure 2 An enlarged cross-sectional view of a main portion of region V is shown.

[0018] Figure 6 This is a flowchart showing the method for manufacturing the capacitor according to the first embodiment.

[0019] Figure 7 It shows Figure 6 Schematic cross-sectional view of the state after step S4 of the manufacturing process is completed.

[0020] Figure 8 Is used to illustrate Figure 6 Schematic cross-sectional view of step S5 of the manufacturing process is shown.

[0021] Figure 9 Is used to illustrate Figure 6 Schematic cross-sectional view of step S6 of the manufacturing process is shown.

[0022] Figure 10 Is used to illustrate Figure 6 Schematic cross-sectional view of step S7 of the manufacturing process is shown.

[0023] Figure 11 Is used to illustrate Figure 6 Schematic cross-sectional view of step S8 of the manufacturing process is shown.

[0024] Figure 12 Is used to illustrate Figure 6 Schematic cross-sectional view of step S9 of the manufacturing process is shown.

[0025] Figure 13 Is used to illustrate Figure 6 Schematic cross-sectional view of step S10 of the manufacturing process is shown.

[0026] Figure 14 Is used to illustrate Figure 6 Schematic cross-sectional view of step S11 of the manufacturing process is shown.

[0027] Figure 15 Is used to illustrate Figure 6 Schematic cross-sectional view of step S12 of the manufacturing process shown.

[0028] Figure 16 Is used to illustrate Figure 6 Schematic cross-sectional view of step S13 of the manufacturing process shown.

[0029] Figure 17 Is used to illustrate Figure 6 Schematic cross-sectional view of step S14 of the manufacturing process shown.

[0030] Figure 18Is used to illustrate Figure 6 Schematic cross-sectional view of step S15 of the manufacturing process is shown.

[0031] Figure 19 Is used to illustrate Figure 6 Schematic cross-sectional view of step S16 of the manufacturing process shown.

[0032] Figure 20 Is used to illustrate Figure 6 Schematic cross-sectional view of step S17 of the manufacturing process shown.

[0033] Figure 21 Is used to illustrate Figure 6 Schematic cross-sectional view of step S18 of the manufacturing process shown.

[0034] Figure 22 Is used to illustrate Figure 6 Schematic cross-sectional view of step S19 of the manufacturing process shown.

[0035] Figure 23 Is used to illustrate Figure 6 FIG. 1 is a schematic cross-sectional view of step S20 of the manufacturing process shown.

[0036] Figure 24 This is a schematic cross-sectional view of a capacitor according to Embodiment 2.

[0037] Figure 25 This is a schematic cross-sectional view of a capacitor according to a third embodiment.

[0038] Figure 26 Graph showing the results of verification test 1.

[0039] Figure 27 Graph showing the results of verification test 2. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the embodiments shown below, identical or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated. Furthermore, in the embodiments shown below, the terms "anode" and "cathode" are used for ease of description. However, the electrical polarity of the capacitor in the embodiments shown below is not solely determined by these terms, and its electrical polarity can be appropriately determined in accordance with the environment in which the capacitor is used.

[0041] (Implementation Method 1)

[0042] Figure 1 (A) is a schematic front view of the capacitor according to the first embodiment. Figure 1 (B) is from Figure 1(A) is a schematic top view of the capacitor viewed in the direction of arrow IB. Figure 2 It is along Figure 1 (B) is a schematic cross-sectional view of a II-II line capacitor shown. Figure 3 It will Figure 2 FIG. 2 is an enlarged schematic cross-sectional view of the vicinity of the first main surface of the insulating substrate. Figure 4 yes Figure 2 An enlarged cross-sectional view of a main portion of region IIII is shown. Figure 5 yes Figure 2 The main part of the region V is shown in an enlarged cross-sectional view. Figures 1 to 5 , the structure of capacitor 1A according to this embodiment will be described.

[0043] like Figure 1 as well as Figure 2 As shown, capacitor 1A has a flat, roughly rectangular shape and is a so-called surface-mounted electronic component whose bottom surface is configured as a mounting surface for a wiring substrate or the like. Capacitor 1A mainly includes an insulating substrate 10, a capacitor forming portion 20, and a sealing portion 30. Among them, the capacitor forming portion 20 is arranged to be opposite to the insulating substrate 10. The capacitor forming portion 20 is located inside the capacitor 1A by being sealed by the insulating substrate 10 and the sealing portion 30 provided on the insulating substrate 10.

[0044] Insulating substrate 10 is provided with first and second via-hole conductors 13 and 14, a plurality of metal wall portions 15, a first bump 16 and a second bump 17, and a plurality of partition walls 18. First and second via-hole conductors 13 and 14, first and second bumps 16 and 17 form a pair of external connection wirings, which serve as lead-out wirings for electrically connecting capacitance-forming portion 20 within capacitor 1A to an external circuit. 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.

[0045] The insulating substrate 10 comprises a flat plate-shaped member having a first main surface 10a and a second main surface 10b located opposite the first main surface 10a. An electrically insulating substrate 10 is preferably used, and a substrate primarily composed of an inorganic material is preferably used. More specifically, the insulating substrate 10 may be a substrate primarily composed of, for example, Si, Al2O3, ZrO2, BN, Si3N4, AlN, MgO, Mg2SiO4, BaTiO3, SrTiO3, or CaTiO3.

[0046] The thickness and size of the insulating substrate 10 are not particularly limited, but an alumina substrate having a thickness of 5 μm to 75 μm inclusive and a side length of 500 μm to 2000 μm inclusive in a plan view is preferably used.

[0047] The insulating substrate 10 is provided with a first through hole 11 extending 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 first via-hole conductor 13 has a substantially cylindrical shape, for example.

[0048] The insulating substrate 10 is provided with a second through hole 12 extending from the first main surface 10a to the second main surface 10b. The second through hole 12 is filled with a second via conductor 14. The second via conductor 14 is, for example, substantially cylindrical in shape.

[0049] The first via-hole conductor 13 forms part of the first external connection wiring described above. The second via-hole conductor 14 forms part of the second external connection wiring described above. Specifically, the first via-hole conductor 13 and the second via-hole conductor 14 form the first external connection wiring and the second external connection wiring, respectively, of different polarities.

[0050] The first via-hole conductor 13 and the second via-hole conductor 14 are both provided in the 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 .

[0051] The first and second via-hole conductors 13 and 14 can be formed from a variety of wiring materials, but are particularly preferably formed from a metal material with high electrical conductivity. The material of the first and second via-hole conductors 13 and 14 can be a metal material primarily composed of, for example, Ni, Ag, Cu, Au, Pt, Mo, or W. The material of the first and second via-hole conductors 13 and 14 can be appropriately modified to suit the installation environment of the capacitor 1A according to this embodiment. Furthermore, the material of the first and second via-hole conductors 13 and 14 does not necessarily need to be the same. In this embodiment, a material containing Ni is used for the first and second via-hole conductors 13 and 14.

[0052] The axial length and size of the first and second via-hole conductors 13 and 14 are not particularly limited and can be appropriately set according to the thickness and size of the insulating substrate 10. The axial lengths of the first and second via-hole conductors 13 and 14 are preferably set, for example, to be between 5 μm and 75 μm, and their diameters are preferably set, for example, to be between 15 μm and 150 μm. In this embodiment, a conductor containing Ni with an axial length of 75 μm and a diameter of 150 μm is used as the first and second via-hole conductors 13 and 14. Furthermore, the distance between the first and second via-hole conductors 13 and 14 is 150 μm.

[0053] A first bump 16 is provided on the second main surface 10b of the insulating substrate 10 so as to cover the first via-hole conductor 13. The first bump 16 serves as a bonding member for mounting the capacitor 1A, a surface-mount electronic component, on a wiring substrate or the like and electrically connecting the capacitance-forming portion 20 of the capacitor 1A to an external circuit. The first bump 16 is provided so as to protrude from the second main surface 10b of the insulating substrate 10. The first bump 16 has a substantially hemispherical shape.

[0054] A second bump 17 is provided on the second main surface 10b of the insulating substrate 10 so as to cover the second via-hole conductor 14. The second bump 17 serves as a bonding member for mounting the capacitor 1A, a surface-mount electronic component, on a wiring substrate or the like and electrically connecting the capacitance-forming portion 20 of the capacitor 1A to an external circuit. The second bump 17 is provided so as to protrude from the second main surface 10b of the insulating substrate 10. The second bump 17 has a substantially hemispherical shape.

[0055] The first bumps 16 constitute part of the first external connection wiring. The second bumps 17 constitute part of the second external connection wiring. That is, the first bumps 16 and the second bumps 17 constitute the first external connection wiring and the second external connection wiring, respectively, of different polarities.

[0056] The first bumps 16 and the second bumps 17 can be formed of various wiring materials, but are preferably formed of a metal material with high electrical conductivity. The material of the first bumps 16 and the material of the second bumps 17 can be a metal material mainly composed of, for example, Ni, Ag, Cu, Au, and Sn. In this embodiment, a material containing Au is used as the first bumps 16 and the second bumps 17.

[0057] The sizes of the first bumps 16 and the second bumps 17 are not particularly limited and can be appropriately set according to the sizes of the first via-hole conductors 13 and the second via-hole conductors 14 .

[0058] As described above, the first external connection wiring serving as the anode of the pair of external connection wirings is constituted by the first via-hole conductor 13 and the first bump 16 , and the second external connection wiring serving as the cathode of the pair of external connection wirings is constituted by the second via-hole conductor 14 and the second bump 17 .

[0059] The insulating substrate 10 is provided with a plurality of metal walls 15 extending from the first main surface 10a toward the capacitor forming portion 20. When viewed along the normal direction of the first main surface 10a, the plurality of metal walls 15 are located between the first and second external connection wirings.

[0060] Here, below, will Figure 2 The left and right directions in the equation are called the first direction. Figure 2 The up and down direction in the image is called the second direction, which is perpendicular to both the first and second directions and Figure 2 In this embodiment, the first direction coincides with the direction connecting the first external connection wiring and the second external connection wiring, and the second direction coincides with the direction parallel to the normal direction of the first main surface 10a.

[0061] The plurality of metal wall portions 15 extend along both the second direction and the third direction. In the present embodiment, the two metal wall portions 15 extend linearly along both the second direction and the third direction.

[0062] In addition, the metal wall portion 15 does not necessarily need to extend in a straight line along the second direction. That is, the metal wall portion 15 may also be erected from the first main surface 10a in a direction that is inclined to a considerable extent relative to the second direction. In addition, the metal wall portion 15 does not necessarily need to extend in a straight line along the third direction. That is, as long as the capacitor forming portion 20 can be divided into a portion located on the first external connection wiring side and a portion located closer to the second external connection wiring side than the portion, the metal wall portion 15 may also extend in a bent or curved shape, for example.

[0063] The dimension (thickness) of the metal wall portion 15 in the first direction is preferably 5 μm to 150 μm, more preferably 5 μm to 75 μm, for example. This effectively suppresses warping that may occur in the insulating substrate 10 described later.

[0064] Furthermore, the dimension (height) of the metal wall portion 15 in the second direction is preferably greater than the dimension (height) of the capacitance-forming portion 20 in the same direction, and the dimension (width) of the metal wall portion 15 in the third direction is preferably greater than the dimension (width) of the capacitance-forming portion 20 in the same direction. This also effectively suppresses possible warping of the insulating substrate 10.

[0065] The metal wall portion 15 can be made of a metal material primarily composed of, for example, Ni, Cu, Ru, Al, W, Ti, Ag, Au, Ta, and Nb. Alternatively, the metal wall portion 15 may be made of an alloy material primarily composed of two or more selected from these metal materials. In this embodiment, a material containing Cu is used as the metal wall portion 15.

[0066] The insulating substrate 10 is further provided with a plurality of partition walls 18 extending from the first main surface 10a toward the capacitance forming portion 20. When viewed along the normal direction of the first main surface 10a, the plurality of partition walls 18 are located between the first external connection wiring and the second external connection wiring.

[0067] The plurality of partition walls 18 extend along both the second direction and the third direction. In the present embodiment, the two partition walls 18 extend linearly along both the second direction and the third direction.

[0068] By dividing the capacitor forming portion 20 with the partition portion 18 constructed in this way, the capacitor forming portion 20 includes a portion located on the first external connection wiring side and a portion located closer to the second external connection wiring side than the portion, thereby achieving an improvement in the withstand voltage of the capacitor 1A, details of which will be described later.

[0069] In addition, the partition wall 18 does not necessarily need to extend in a straight line along the second direction. That is, the partition wall 18 may also be erected from the first main surface 10a in a direction that is inclined to a considerable extent relative to the second direction. In addition, the partition wall 18 does not necessarily need to extend in a straight line along the third direction. That is, as long as the capacitor forming portion 20 can be divided into a portion located on the first external connection wiring side and a portion located closer to the second external connection wiring side than the portion, the partition wall 18 may also extend in a bent or curved shape, for example.

[0070] The dimension (thickness) of the partition wall portion 18 in the first direction is preferably set to, for example, 5 μm or more and 150 μm or less, more preferably 5 μm or more and 75 μm or less. This not only reliably prevents the conductive films 23 of the pair of capacitor-forming portions divided by the partition wall portion 18 from being unintentionally formed continuously, but also effectively suppresses possible warping of the insulating substrate 10.

[0071] Furthermore, the dimension (height) of the partition wall portion 18 in the second direction is preferably greater than the dimension (height) of the capacitance-forming portion 20 in the same direction, and the dimension (width) of the partition wall portion 18 in the third direction is preferably greater than the dimension (width) of the capacitance-forming portion 20 in the same direction. This not only reliably prevents the conductive films 23 of the pair of capacitance-forming portions divided by the partition wall portion 18 from being unintentionally formed continuously, but also effectively suppresses any warping that may occur in the insulating substrate 10.

[0072] The partition wall 18 is preferably formed of a material that is the same as at least a portion of the material contained in the metal porous body 21 described later. The material of the partition wall 18 can be a metal material with any one of Ni, Cu, Ru, Al, W, Ti, Ag, Au, Ta, and Nb as a main material. Alternatively, the partition wall 18 can be formed of an alloy material with two or more selected from these metal materials as main components. In this embodiment, a material containing Ni is used as the partition wall 18.

[0073] As described above, capacitor 1A according to this embodiment includes two metal walls 15 and two partition walls 18. Hereinafter, the metal wall portion located on the first external connection wiring side of the two metal walls 15 will be referred to as metal wall 15A, and the metal wall portion located closer to the second external connection wiring side than metal wall 15A will be referred to as metal wall 15B. Similarly, the partition wall portion located on the first external connection wiring side of the two partition walls 18 will be referred to as partition wall 18A, and the partition wall portion located closer to the second external connection wiring side than partition wall 18A will be referred to as partition wall 18B.

[0074] The two metal wall portions 15 and the two partition wall portions 18 extend from the first external connection wiring side toward the second external connection wiring side (i.e., from Figure 2 The metal wall portion 15A, the partition portion 18A, the metal wall portion 15B, and the partition portion 18B are arranged in this order (from the right side to the left side in FIG). By configuring in this way, the capacitance forming portion 20 can be divided into a plurality of capacitance forming portions, which will be described in detail later.

[0075] like Figure 2 As shown, the capacitor forming portion 20 is arranged to be opposite to the first main surface 10a of the insulating substrate 10, and includes a conductive metal porous body 21 having a plurality of fine pores inside, 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.

[0076] In addition, although the capacitor forming portion 20 is arranged to be opposite to the insulating substrate 10, it is not actually directly bonded to the insulating substrate 10, or even if it is directly bonded, it is only slightly bonded. Here, the so-called state in which the capacitor forming portion 20 is only slightly bonded to the insulating substrate 10 means a state in which a portion of the capacitor forming portion 20 is bonded to the insulating substrate 10 at a given ratio or less. That is, the so-called state in which the capacitor forming portion 20 is only slightly bonded to the insulating substrate 10 means that Figure 3 As shown, in a cross section perpendicular to the extending direction of the first main surface 10a of the insulating substrate 10, when observing an arbitrary region on the first main surface 10a of the insulating substrate 10, in the arbitrary region, the total length of the line segment parallel to the first main surface 10a of the portion where the porous metal body 21 is bonded to the insulating substrate 10 directly or indirectly via the dielectric film 22 or the conductive film 23 (i.e., in Figure 3 In the example shown, the line segment length is b1+b2), which is the total line segment length in the arbitrary region of the first main surface 10a (i.e., Figure 3 In the example shown, it is less than 30% of the line segment length a).

[0077] In the porous metal body 21, at least a portion of the plurality of fine pores provided therein is not closed by the porous metal body itself. Preferably, most or all of the plurality of fine pores provided therein are not closed by the porous metal body itself. Such a porous metal body is composed of, for example, a sintered body of metal particles.

[0078] The porous metal body 21 can be made of various conductive metal materials, but is preferably made of a metal material primarily composed of any one of Ni, Mo, W, Al, Ti, Ta, Nb, Cu, Pt, Au, and Ag. Alternatively, the porous metal body 21 may be made of an alloy material primarily composed of two or more of these metal materials. In this embodiment, a material containing Ni is used as the porous metal body 21.

[0079] The thickness and size of the porous metal body 21 are not particularly limited, and in particular, the size can be appropriately set according to the size of the insulating substrate 10. In this embodiment, as described later, the porous metal body 21 is a 1000 μm square and 200 μm thick metal body before the capacitor forming portion 20 is divided.

[0080] Here, as described above, the porous metal body 21 is preferably formed 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.

[0081] Here, as Figure 2 As shown, a portion of the porous metal body 21 is bonded to the second via-hole conductor 14 . Therefore, the second external connection wiring serving as the cathode is connected to the capacitance forming portion 20 via the second via-hole conductor 14 .

[0082] 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 fine pores not enclosed by the porous metal body itself. Furthermore, the dielectric film 22 also covers the surface of the partition wall 18 in the portion not bonded to the porous metal body 21.

[0083] The dielectric film 22 can be formed of various insulating materials, for example, AlO x 、SiO x , HfO x 、TiO x 、TaO x 、ZrO x 、SiAlO x 、HfAlO x 、ZrAlO x 、AlTiO x 、SrTiO x 、HfSiO x 、ZrSiO x 、TiZrO x 、TiZrO x 、TiZrWO x 、SrTiO 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 Ny , HfO x N y 、SiC x O y N z The dielectric film 22 is formed of metal nitrides 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 can be formed using any of the following materials. The above chemical formula merely illustrates the material composition and does not limit the composition. Specifically, x, y, and z added to O and N can be any value greater than 0, and the ratio of the elements, including metal elements, can be arbitrary. Furthermore, the dielectric film 22 can be formed using a laminated film comprising multiple dielectric layers made of different materials. In this embodiment, a material comprising AlSiO is used as the dielectric film 22.

[0084] The dielectric film 22 can be preferably 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.

[0085] The thickness of dielectric film 22 is not particularly limited, but is preferably 3 nm to 100 nm, more preferably 5 nm to 50 nm. A thickness of dielectric film 22 of 3 nm or greater can improve the withstand voltage of capacitor 1A.

[0086] As described above, conductive film 23 covers the surface of dielectric film 22. More specifically, conductive film 23 covers not only the surface of dielectric film 22 located on the outermost side of capacitance forming portion 20 but also the surface of dielectric film 22 located inside capacitance forming portion 20.

[0087] Here, the conductive film 23 does not cover the portion of the surface of the dielectric film 22 that covers the partition wall 18 or the portion thereof located near the partition wall 18. Consequently, the portion of the conductive film 23 on the first external connection wiring side when viewed from the partition wall 18 and the portion of the conductive film 23 on the second external connection wiring side when viewed from the partition wall 18 are discontinuous with each other. This configuration improves the withstand voltage of the capacitor 1A, as will be described in detail later.

[0088] The conductive film 23 can be formed of various conductive materials, including a metal material primarily composed of any 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. Among these, the conductive film 23 is preferably formed of TiN or TiON, or an oxide semiconductor such as ZnO or RuO. In this embodiment, a material containing TiN is used as the conductive film 23.

[0089] 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, with ALD being particularly suitable. Alternatively, the conductive film 23 may be formed as a laminated film comprising multiple conductive layers made of different materials. In this case, film formation can be performed using other methods after film formation using ALD.

[0090] The thickness of the conductive film 23 is not particularly limited, but is preferably 3 nm or more, and more preferably 10 nm or more.

[0091] Here, the dielectric film 22 and the conductive film 23 not only cover the surface of the porous metal body 21, but also cover a predetermined portion of the first main surface 10a side of the insulating substrate 10. Figure 4 As shown, the dielectric film 22 and the conductive film 23 also cover the portion of the surface of the insulating substrate 10 defining the first through-hole 11 provided in the insulating substrate 10. More specifically, at the boundary between the first via-hole conductor 13 and the base material of the insulating substrate 10, the base material of the insulating substrate 10 is covered by the dielectric film 22, the dielectric film 22 is covered by the conductive film 23, and the conductive film 23 is further covered by the first via-hole conductor 13. Furthermore, the end of the first via-hole conductor 13 on the first principal surface 10a side is covered by the capacitance-forming portion 20.

[0092] As a result, the conductive film 23 is bonded to the first via-hole conductor 13 . Therefore, the first external connection wiring serving as the anode is connected to the capacitance forming portion 20 via the first via-hole conductor 13 .

[0093] like Figure 2 As shown, the sealing portion 30 is provided on the first main surface 10a of the insulating substrate 10, and seals the capacitance-forming portion 20 together with the insulating substrate 10, and defines an outer surface 30a located on the side opposite to the insulating substrate 10 side when viewed from the capacitance-forming portion 20. More specifically, the sealing portion 30 is configured to cover the upper, lateral, and lower sides of the capacitance-forming portion 20 disposed opposite the first main surface 10a of the insulating substrate 10, and is further configured to fill the hole provided inside the capacitance-forming portion 20.

[0094] The sealing portion 30 can be made of various insulating materials, but it is particularly preferred to use an insulating material with excellent weather resistance to form the sealing portion 30. The material of the sealing portion 30 can be, for example, a resin material such as polyimide resin, polybenzoxazole resin, polyethylene terephthalate resin, benzocyclobutene resin, or epoxy resin. In addition, the resin material can contain various additives, for example, SiO2 filler, Al2O3 filler, etc., in order to adjust the thermal expansion coefficient. In this embodiment, a material containing epoxy resin is used as the sealing portion 30.

[0095] In addition, when it is difficult to ensure moisture resistance only by the sealing portion 30, a moisture-resistant protective film can also be formed between the capacitor forming portion 20 and the sealing portion 30. The moisture-resistant protective film can be formed by, for example, before forming the sealing portion 30, utilizing a CVD method, an ALD method, etc. to set an inorganic insulator comprising SiN, SiO2, Al2O3, HfO2, ZrO2, etc. to cover the capacitor forming portion 20, or to set a hydrophobic organic insulator such as a fluorine-based resin or a silane coupling agent resin to cover the capacitor forming portion 20. Here, the moisture-resistant protective film does not necessarily need to be formed to the inside of the capacitor forming portion 20, and it is sufficient as long as it is formed to cover only the outer surface.

[0096] The sealing portion 30 can be formed by various coating methods, for example, a method using a vacuum laminator, a method using an air dispenser, a method using a jet dispenser, screen printing, vacuum printing, electrostatic coating, inkjet, photolithography, etc.

[0097] The thickness and size of the sealing portion 30 are not particularly limited, and the size can be appropriately set according to the size of the insulating substrate 10. Here, the thickness of the sealing portion 30 is preferably set to, for example, 5 μm or more and 50 μm or less, and the size is preferably such that the entire first main surface 10 a of the insulating substrate 10 is covered.

[0098] The thickness of the sealing portion 30 is measured by, for example, observing a cross section perpendicular to the extending direction of the first main surface 10 a of the insulating substrate 10 using an optical microscope.

[0099] Specifically, when viewing capacitor 1A from above, with its longitudinal direction Lx, its transverse direction Ly, and its thickness direction (i.e., the normal direction to first principal surface 10a) Lz, capacitor 1A is first polished to expose the Lx-Lz cross section of capacitor 1A at the center portion in the Ly direction. Polishing is performed so that the exposed cross section lies within an error range of ±100 μm in the Ly direction relative to the center position.

[0100] Next, the portion near the outer surface 30a in the exposed cross section was observed using an optical microscope at a magnification of 1000. The observation range in the Lx direction of the cross section was a range of ±50 μm relative to the center position of the cross section in the Lx direction, and was a range where neither the metal wall portion 15 nor the partition wall portion 18 was provided.

[0101] Next, within the observation range of the cross section, the thickness of the sealing portion 30 in the Lz direction is measured at 10 locations at equal intervals in the Lx direction, and the average value thereof is calculated. The average value calculated in this way becomes the thickness of the sealing portion 30. Figure 5 In FIG. 1 , three of the thicknesses in the Lz direction of the sealing portion 30 measured at these ten locations are exemplified as line segment lengths e1 , e2 , and e3 .

[0102] By having the above structure, in the capacitor 1A involved in this embodiment, the capacitor forming part 20 including the metal porous body 21, the dielectric film 22 and the conductive film 23 is sealed by the insulating substrate 10 and the sealing part 30, and the electrical lead-out of the capacitor forming part 20 is achieved through a pair of external connection wirings.

[0103] Here, as Figure 2 As shown, in the capacitor 1A according to the present embodiment, the capacitance forming portion 20 is divided into a plurality of capacitance forming portions by a plurality of metal wall portions 15 and a plurality of partition walls 18. These plurality of capacitance forming portions extend from the first external connection wiring side toward the second external connection wiring side (i.e., from the first external connection wiring side to the second external connection wiring side). Figure 2 right side facing left side).

[0104] The capacitor forming portion 20 in this embodiment is divided into five. For the sake of convenience, these five capacitor forming portions are referred to as capacitor forming portion 20A, capacitor forming portion 20B, capacitor forming portion 20C, capacitor forming portion 20D and capacitor forming portion 20E, starting from the capacitor forming portion closest to the first external connection wiring.

[0105] In the present embodiment, the porous metal body 21 , the dielectric film 22 , and the conductive film 23 defining the capacitance forming portion 20A are referred to as the porous metal body 21A, the dielectric film 22A, and the conductive film 23A, respectively. Similarly, the metal porous body 21, dielectric film 22 and conductive film 23 that define the capacitor forming portion 20B are referred to as the metal porous body 21B, dielectric film 22B and conductive film 23B, respectively; the metal porous body 21, dielectric film 22 and conductive film 23 that define the capacitor forming portion 20C are referred to as the metal porous body 21C, dielectric film 22C and conductive film 23C, respectively; the metal porous body 21, dielectric film 22 and conductive film 23 that define the capacitor forming portion 20D are referred to as the metal porous body 21D, dielectric film 22D and conductive film 23D, respectively; and the metal porous body 21, dielectric film 22 and conductive film 23 that define the capacitor forming portion 20E are referred to as the metal porous body 21E, dielectric film 22E and conductive film 23E, respectively.

[0106] In this embodiment, the capacitance-forming portion 20A corresponds to the first capacitance-forming portion, and the capacitance-forming portions 20B to 20E correspond to the second capacitance-forming portion. Therefore, the porous metal body 21A corresponds to the first porous metal body, the dielectric film 22A corresponds to the first dielectric film, the conductive film 23A corresponds to the first conductive film, the porous metal bodies 21B to 21E correspond to the second porous metal body, the dielectric films 22B to 22E correspond to the second dielectric film, and the conductive films 23B to 23E correspond to the second conductive film.

[0107] In this embodiment, the capacitance-forming portion 20B corresponds to the third capacitance-forming portion, and the capacitance-forming portions 20C to 20E correspond to the fourth capacitance-forming portion. Therefore, the porous metal body 21B corresponds to the third porous metal body, the dielectric film 22B corresponds to the third dielectric film, the conductive film 23B corresponds to the third conductive film, the porous metal bodies 21C to 21E correspond to the fourth porous metal body, the dielectric films 22C to 22E correspond to the fourth dielectric film, and the conductive films 23C to 23E correspond to the fourth conductive film.

[0108] Furthermore, in this embodiment, the capacitance-forming portion 20C corresponds to the fifth capacitance-forming portion, and the capacitance-forming portions 20D and 20E correspond to the sixth capacitance-forming portion. Therefore, the porous metal body 21C corresponds to the fifth porous metal body, the dielectric film 22C corresponds to the fifth dielectric film, the conductive film 23C corresponds to the fifth conductive film, the porous metal bodies 21D and 21E correspond to the sixth porous metal body, the dielectric films 22D and 22E correspond to the sixth dielectric film, and the conductive films 23D and 23E correspond to the sixth conductive film.

[0109] In this embodiment, the capacitance-forming portion 20D corresponds to the seventh capacitance-forming portion, and the capacitance-forming portion 20E corresponds to the eighth capacitance-forming portion. Therefore, the porous metal body 21D corresponds to the seventh porous metal body, the dielectric film 22D corresponds to the seventh dielectric film, the conductive film 23D corresponds to the seventh conductive film, the porous metal body 21E corresponds to the eighth porous metal body, the dielectric film 22E corresponds to the eighth dielectric film, and the conductive film 23E corresponds to the eighth conductive film.

[0110] Furthermore, in the present embodiment, the metal wall portion 15A and the metal wall portion 15B correspond to the first metal wall portion and the second metal wall portion, respectively, and the partition wall portion 18A and the partition wall portion 18B correspond to the first partition wall portion and the second partition wall portion, respectively.

[0111] Hereinafter, the structure of the plurality of capacitance forming portions 20A to 20E and the relationship between the plurality of capacitance forming portions 20A to 20E, the metal wall portion 15 , and the partition portion 18 will be described in detail.

[0112] In the capacitor 1A according to this embodiment, as Figure 2 as well as Figure 5 As shown, the conductive film 23 of the capacitor forming portion 20 is configured to be discontinuous with the partition portion 18A and its vicinity as the boundary. More specifically, the conductive film 23A of the capacitor forming portion 20A, which is the portion on the first external connection wiring side when viewed from the partition portion 18A, and the conductive film 23B of the capacitor forming portion 20B, which is the portion on the second external connection wiring side when viewed from the partition portion 18A and is adjacent to the partition portion 18A, are configured to be discontinuous with each other. In other words, since the conductive film 23 includes the mutually discontinuous conductive film 23A and the conductive film 23B, the capacitor forming portion 20 includes the capacitor forming portion 20A defined by the conductive film 23A, the dielectric film 22A of the dielectric film 22 as the portion corresponding to the conductive film 23A, and the metal porous body 21A of the metal porous body 21 as the portion corresponding to the dielectric film 22A, and the capacitor forming portion 20B defined by the conductive film 23B, the dielectric film 22B of the dielectric film 22 as the portion corresponding to the conductive film 23B, and the metal porous body 21B of the metal porous body 21 as the portion corresponding to the dielectric film 22B.

[0113] The conductive film 23A of the capacitance forming portion 20A is bonded to the first via-hole conductor 13 , and the porous metal body 21E of the capacitance forming portion 20E is bonded to the second via-hole conductor 14 .

[0114] The partition wall 18A divides the metal porous bodies 21A to 21E into the metal porous body 21A and the metal porous bodies 21B to 21E, divides the dielectric films 22A to 22E into the dielectric film 22A and the dielectric films 22B to 22E, and further divides the conductive films 23A to 23E into the conductive film 23A and the conductive films 23B to 23E.

[0115] Furthermore, partition wall 18A is not bonded to conductive film 23A or conductive film 23B. On the other hand, partition wall 18A is bonded to porous metal body 21A of capacitor-forming portion 20A on the side facing the first external connection wiring, and is bonded to porous metal body 21B of capacitor-forming portion 20B on the side facing the second external connection wiring.

[0116] With this configuration, capacitance-forming portions 20B to 20E are electrically connected to the first external connection wiring via capacitance-forming portion 20A, and capacitance-forming portion 20A is electrically connected to the second external connection wiring via capacitance-forming portions 20B to 20E. As a result, capacitance-forming portion 20A and capacitance-forming portions 20B to 20E are electrically connected in series between the first external connection wiring and the second external connection wiring via partition portion 18A.

[0117] Furthermore, in capacitor 1A, metal wall portion 15A is provided on insulating substrate 10, thereby dividing capacitance-forming portion 20B to 20E within capacitance-forming portion 20 into capacitance-forming portion 20B and remaining capacitance-forming portions 20C to 20E. Capacitance-forming portion 20B is located on the first external connection wiring side, while capacitance-forming portions 20C to 20E are located closer to the second external connection wiring side than capacitance-forming portion 20B.

[0118] Here, in capacitor 1A, metal wall portion 15A is bonded to conductive film 23B of capacitance-forming portion 20B, but is not bonded to porous metal body 21B or dielectric film 22B. Furthermore, metal wall portion 15A is bonded to conductive film 23C of capacitance-forming portion 20C, which is adjacent to metal wall portion 15A among capacitance-forming portions 20C to 20E, but is not bonded to porous metal body 21C or dielectric film 22C.

[0119] With this configuration, capacitance-forming portions 20C to 20E are electrically connected to the first external connection wiring via capacitance-forming portion 20B, and capacitance-forming portion 20B is electrically connected to the second external connection wiring via capacitance-forming portions 20C to 20E. As a result, capacitance-forming portion 20B and capacitance-forming portions 20C to 20E are electrically connected in series between the first external connection wiring and the second external connection wiring.

[0120] Furthermore, in capacitor 1A, the conductive film 23 of the portion corresponding to capacitance-forming portions 20C to 20E of capacitance-forming portion 20 is discontinuous with partition 18B and its vicinity serving as a boundary. More specifically, conductive film 23C of capacitance-forming portion 20C, which is the portion on the first external connection wiring side when viewed from partition 18B, and conductive film 23D of capacitance-forming portion 20D, which is the portion on the second external connection wiring side when viewed from partition 18B, are discontinuous with each other. In other words, since the conductive film 23 includes a conductive film 23C and a conductive film 23D that are discontinuous with each other, the capacitor forming portion 20 includes a capacitor forming portion 20C defined by the conductive film 23C, the dielectric film 22C of the dielectric film 22 as a portion corresponding to the conductive film 23C, and the metal porous body 21C of the metal porous body 21 as a portion corresponding to the dielectric film 22C, and a capacitor forming portion 20D defined by the conductive film 23D, the dielectric film 22D of the dielectric film 22 as a portion corresponding to the conductive film 23D, and the metal porous body 21D of the metal porous body 21 as a portion corresponding to the dielectric film 22D.

[0121] Partition wall 18B divides porous metal bodies 21C to 21E into porous metal body 21C and porous metal bodies 21D and 21E, divides dielectric films 22C to 22E into dielectric film 22C and dielectric films 22D and 22E, and further divides conductive films 23C to 23E into conductive film 23C and conductive films 23D and 23E.

[0122] Furthermore, partition wall 18B is not bonded to conductive film 23C or conductive film 23D. On the other hand, partition wall 18B is bonded to porous metal body 21C of capacitor-forming portion 20C on the side facing the first external connection wiring, and is bonded to porous metal body 21D of capacitor-forming portion 20D on the side facing the second external connection wiring.

[0123] With this configuration, capacitance-forming portions 20D and 20E are electrically connected to the first external connection wiring via capacitance-forming portion 20C, and capacitance-forming portion 20C is electrically connected to the second external connection wiring via capacitance-forming portions 20D and 20E. As a result, capacitance-forming portion 20C and capacitance-forming portions 20D and 20E are electrically connected in series between the first external connection wiring and the second external connection wiring via partition portion 18B.

[0124] Furthermore, in capacitor 1A, metal wall portion 15B is provided on insulating substrate 10, thereby dividing capacitance-forming portion 20D and capacitance-forming portion 20E within capacitance-forming portion 20 into capacitance-forming portion 20D and capacitance-forming portion 20E. Capacitance-forming portion 20D is located on the first external connection wiring side, while capacitance-forming portion 20E is located closer to the second external connection wiring side than capacitance-forming portion 20D.

[0125] Here, in capacitor 1A, metal wall portion 15B is bonded to conductive film 23D of capacitance-forming portion 20D, but is not bonded to porous metal body 21D or dielectric film 22D. Furthermore, metal wall portion 15B is bonded to conductive film 23E of capacitance-forming portion 20E, but is not bonded to porous metal body 21E or dielectric film 22E.

[0126] With this configuration, capacitance-forming portion 20E is electrically connected to the first external connection wiring via capacitance-forming portion 20D, and capacitance-forming portion 20D is electrically connected to the second external connection wiring via capacitance-forming portion 20E. As a result, capacitance-forming portion 20D and capacitance-forming portion 20E are electrically connected in series between the first external connection wiring and the second external connection wiring.

[0127] By having the above structure, in the capacitor 1A involved in this embodiment, the capacitance forming part 20A, the capacitance forming part 20B, the capacitance forming part 20C, the capacitance forming part 20D and the capacitance forming part 20E are electrically connected in series between the first external connection wiring and the second external connection wiring.

[0128] In addition, in the present embodiment, as described above, the case where five capacitor forming portions 20A to 20E are connected in series is exemplified, but the number of capacitor forming portions connected in series (i.e., the number of divisions of the capacitor forming portion 20) can be multiple, and is not particularly limited to 5. It can also be more than 2 and less than 4, or more than 6. In the case of changing the number of capacitor forming portions connected in series, it is sufficient to appropriately change the number of other portions where the conductive film 23 is discontinuously formed and the number of metal wall portions 15 added to the capacitor having a portion where one conductive film 23 is discontinuously formed. In this case, it is necessary that the portion where the conductive film 23 is discontinuously formed and the metal wall portion 15 are alternately arranged from the first external connection wiring side toward the second external connection line side.

[0129] In addition, in the capacitor 1A that the present embodiment relates to above-mentioned, conductive film 23A and conductive film 23B are formed as mutually discontinuous, and, metal porous body 21A and metal porous body 21B are engaged with the partition wall 18A that is arranged between capacitor forming part 20A and capacitor forming part 20B, thus realized that capacitor forming part 20A and capacitor forming part 20B are divided mutually and they are electrically connected in series, but in capacitor 1A, it is not necessary to set partition wall 18A. That is, even when partition wall 18A is not set and metal porous body 21A and metal porous body 21B are engaged with each other, as long as conductive film 23A and conductive film 23B are formed as mutually discontinuous, then it is also possible to realize that capacitor forming part 20A and capacitor forming part 20B are divided mutually and they are electrically connected in series as described above. This is also the same for the relationship between partition wall 18B and capacitor forming part 20C and capacitor forming part 20D.

[0130] Figure 6 1 is a flowchart illustrating a method for manufacturing a capacitor according to this embodiment. Figures 7 to 23 They are used to illustrate Figure 6 Schematic cross-sectional views of the various steps of the manufacturing process shown. Figures 6 to 23 An example of a specific manufacturing method for manufacturing the capacitor 1A according to the present embodiment described above will be described.

[0131] The manufacturing method of capacitor 1A shown below is a method of producing a collection of capacitors in the process of being processed by processing them together until the mid-stage of the manufacturing process, then dividing the collection into pieces, and further processing the semi-finished products after being monolithic to produce a large number of capacitors 1A at the same time.

[0132] First, if Figure 6 As shown, in step S1, a green sheet is produced. Specifically, Al2O3 powder and glass powder are weighed, mixed with these Al2O3 powder and glass powder, 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. After the green sheet is produced, it is cut to prepare multiple green sheets.

[0133] Next, if Figure 6 As shown, in step S2, first and second through-holes are formed in a portion of the plurality of green sheets. Specifically, a first through-hole 11, which will later be filled with a first via-hole conductor serving as a portion of the anode, is provided at a predetermined position on the green sheet, and a second through-hole 12, which will later be filled with a second via-hole conductor serving as a portion of the cathode, is provided.

[0134] Here, there is no particular limitation on the method for forming the first through-holes 11 and the second through-holes 12. For example, the first through-holes 11 and the second through-holes 12 can be formed by irradiating the green sheet with a laser. Alternatively, the first through-holes 11 and the second through-holes 12 can be formed by machining using a mechanical punch or sandblasting.

[0135] Next, if Figure 6 As shown, in step S3, a second via conductor is formed on the green sheet in which the first and second through holes are formed. Specifically, a conductive paste is applied to the green sheet to fill the second through hole 12. At this time, the first through hole 11 is not filled with the conductive paste.

[0136] Here, the method for applying the conductive paste is not particularly limited, but for example, a screen printing method can be used.

[0137] Next, if Figure 6 As shown, in step S4, the green sheets are fired. Specifically, the green sheet without the first and second through-holes is overlapped with the green sheet coated with the conductive paste in step S3, and these overlapped green sheets are pressure-bonded. The pressure-bonded green sheet stack is then degreased, and the degreased green sheet stack is then fired.

[0138] When stacking the green sheets, a green sheet without the first through-holes 11 and second through-holes 12 is stacked on the other main surface of the green sheet coated with the conductive paste, which is opposite the one main surface. Furthermore, a uniaxial press can be used, for example, to press-bond the green sheets. Furthermore, the green sheets are fired, for example, at a temperature of 700°C to 1000°C in an air atmosphere.

[0139] By going through the steps S1 to S4 described above, the following can be obtained: Figure 7 Here, the insulating substrate is a so-called multi-piece substrate that is ultimately included in the insulating substrates of the plurality of capacitors and is connected in a matrix. Figure 7 In FIG. 1 , only one insulating substrate 10 is focused on, and its surroundings are omitted by using dotted lines.

[0140] Furthermore, in the above description, the first through hole and the second through hole are formed in step S2 and then the second via conductor is provided in step S3. However, only the second through hole may be formed first, and the first through hole may be formed after the second via conductor is formed.

[0141] In addition, while the above description illustrates the case where the green sheet and the conductive paste are fired simultaneously, the second via conductor 14 and the first through-hole 11 can also be provided after firing an insulating substrate without through-holes. In this case, the first through-hole 11 and the second through-hole 12 can be provided on the fired insulating substrate by, for example, sandblasting, wet etching, dry etching, etc., and then the conductive paste can be applied and fired. Alternatively, the second via conductor 14 can be formed by sputtering, vapor deposition, plating, etc.

[0142] Next, if Figure 6 As shown, in step S5 , a conductive paste for forming the porous metal body 21 constituting the capacitor forming portion 20 is applied.

[0143] In more detail, Figure 8 As shown, a conductive paste 21p, used to form the porous metal body 21 described later, is applied to the first main surface 10a of the insulating substrate 10. The conductive paste 21p is prepared by weighing and mixing conductive metal particles 21a and a binder 21b, which is a varnish containing an organic solvent such as terpineol and ethyl cellulose, using a roller. The thus prepared conductive paste 21p is applied to the first main surface 10a of the insulating substrate 10 and dried to form a rectangular pattern as a whole when viewed from above.

[0144] At this time, the conductive paste 21p is applied in multiple layers, overlapping each other, to form a layer having a predetermined thickness on the first main surface 10a. The conductive paste 21p applied to the first main surface 10a undergoes a firing step described below to become the aforementioned porous metal body 21. In this embodiment, the conductive paste 21p containing metal particles 21a containing Ni is used.

[0145] Here, before applying the conductive paste 21p, it is preferable to apply an epoxy resin (not shown) or the like to the first through-hole 11 provided in the insulating substrate 10, thereby providing a blocking portion that blocks the first through-hole 11. This prevents the conductive paste 21p from intruding into the first through-hole 11.

[0146] Next, if Figure 6 As shown in FIG. 1 , in step S6, a partition wall groove is formed. Figure 9 As shown, the conductive paste 21p located between the first through hole 11 and the second via conductor 14 when viewed along the normal direction of the first main surface 10a is formed in a direction intersecting with the direction connecting the first through hole 11 and the second via conductor 14 (i.e., Figure 9Conductive paste 21p is divided into a plurality of sections by a plurality of partition wall grooves 18h extending in a direction perpendicular to the paper plane. These plurality of partition wall grooves 18h are filled with partition walls in a partition wall forming step described later.

[0147] In this embodiment, the two partition wall grooves 18h are formed from the first through hole 11 side toward the second via-hole conductor 14 side (ie, from Figure 9 Thus, the conductive paste 21p is divided into a portion corresponding to the porous metal body 21A, a portion corresponding to the porous metal body 21B and the porous metal body 21C, and a portion corresponding to the porous metal body 21D and the porous metal body 21E.

[0148] Here, there is no particular limitation on the method for forming the partition wall grooves 18h. For example, the partition wall grooves 18h can be formed by irradiating the conductive paste 21p with a laser. Alternatively, the partition wall grooves 18h can be formed by machining using a mechanical punch or sandblasting.

[0149] Next, if Figure 6 As shown in FIG. 1 , in step S7, a partition wall portion is formed. Figure 10 As shown, conductive paste is filled into the plurality of partition wall grooves 18h so as to fill the partition wall grooves 18h. The two partition wall portions 18 formed in this manner are arranged upright from the first main surface 10a toward the conductive paste 21p. Furthermore, the partition wall portion located on the first external connection wiring side of these two partition wall portions 18 corresponds to the aforementioned partition wall portion 18A, and the partition wall portion located closer to the second external connection wiring side than the partition wall portion 18A corresponds to the partition wall portion 18B.

[0150] In this embodiment, Ni paste is used as the conductive paste filled in the partition wall grooves 18h. With this configuration, the metal wall portions 15 can be formed from the same material as that contained in the metal particles 21a (i.e., the material contained in the porous metal body 21). As a result, the partition wall portions 18 and the porous metal body 21 are firmly metallically bonded after the firing step described below.

[0151] Here, the method for applying the conductive paste to fill the partition wall grooves 18h is not particularly limited, but an inkjet method can be used, for example.

[0152] Then, if Figure 6 As shown in FIG. 1 , in step S8, a groove for a metal wall portion is formed. Figure 11As shown, the conductive paste 21p of the portion located between the partition portion 18A and the partition portion 18B when viewed along the normal direction of the first main surface 10a (i.e., the conductive paste 21p of the portion corresponding to the metal porous body 21B and the metal porous body 21C) forms a groove 15h for the metal wall portion extending in a direction intersecting with the direction connecting the first through hole 11 and the second via conductor 14, thereby dividing the conductive paste 21p of the above-mentioned portion into a portion corresponding to the metal porous body 21B and a portion corresponding to the metal porous body 21C. Similarly, the conductive paste 21p located between the partition portion 18A and the second via conductor 14 when viewed along the normal direction of the first main surface 10a (i.e., the conductive paste 21p corresponding to the metal porous body 21D and the metal porous body 21E) forms a groove 15h for the metal wall portion extending in a direction intersecting with the direction connecting the first through hole 11 and the second via conductor 14, thereby dividing the conductive paste 21p in the above-mentioned portion into a portion corresponding to the metal porous body 21D and a portion corresponding to the metal porous body 21E.

[0153] Note that these two metal wall grooves 15h are filled with the metal wall in a metal wall forming step described later.

[0154] The method for forming the metal wall groove 15h is not particularly limited, but the metal wall groove 15h can be formed by, for example, irradiating the conductive paste 21p with a laser. Alternatively, the metal wall groove 15h can be formed by machining using a mechanical punch or sandblasting.

[0155] Next, if Figure 6 As shown in FIG. 1 , in step S9, the conductive paste and the partition wall are fired. Figure 12 As shown, conductive paste 21p and partition wall 18 are fired, thereby sintering adjacent metal particles 21a contained in conductive paste 21p to form metallic bonds, and partition wall 18 is bonded to adjacent metal particles 21a. Furthermore, this firing also bonds second via-hole conductor 14 to adjacent metal particles 21a.

[0156] As a result, in this embodiment, partition wall 18A is bonded to adjacent porous metal bodies 21A and 21B, partition wall 18B is bonded to adjacent porous metal bodies 21C and 21D, and second via conductor 14 is bonded to adjacent porous metal body 21E.

[0157] Furthermore, during the above-mentioned firing, the blocking portion made of epoxy resin or the like that blocks the first through hole 11 is also burned by the heat.

[0158] Before the firing, insulating substrate 10 is degreased, and then conductive paste 21p and barrier ribs 18 are fired at 400°C to 900°C in a reducing atmosphere of nitrogen and hydrogen.

[0159] The atmosphere during firing is preferably a reducing atmosphere as described above, but can be set to an atmosphere having an equilibrium oxygen partial pressure or lower of the metal selected as the main component of the metal particles 21 a .

[0160] Here, as described above, the partition wall 18 is composed of Ni, which is the same material as the material contained in the metal particles 21a in the conductive paste 21p. In this configuration, the metal particles 21a and the partition wall 18 are sintered by the above-mentioned firing to form a metallic bond, thereby improving the mechanical strength of the bond between the metal particles 21a and the partition wall 18.

[0161] Next, if Figure 6 As shown, in step S10, a dielectric film is formed. In more detail, as Figure 13 As shown, the dielectric film 22 is formed so as to cover the first main surface 10a, the metal porous body 21, and the surface of the partition portion 18 that is not bonded to the metal porous body 21, and to cover the surface of the insulating substrate 10 that defines the first through hole 11 provided in the insulating substrate 10.

[0162] The method for forming the dielectric film 22 is not particularly limited, but the ALD method is preferably used. The ALD method allows the raw material for the dielectric film 22 to be supplied by gas, enabling the selection of materials and adjustment of the film thickness at the atomic level. Therefore, even when the micropores provided within the porous metal body 21 are extremely small, a homogeneous and dense dielectric film 22 can be formed. Furthermore, the ALD method makes it easy to cover the surface of the insulating substrate 10, which defines the first through-hole 11 provided in the insulating substrate 10, with the dielectric film 22.

[0163] When the dielectric film 22 is formed using the ALD method, it is preferable to use a gas having high vapor pressure, easy gasification, high thermal stability, and high reactivity as the raw material gas so that the raw material gas can spread throughout the fine pores provided in the porous metal body 21 and the first through-holes 11 provided in the insulating substrate 10. 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 (tris(dimethylamino)silane) is preferably used as a raw material. In this embodiment, the dielectric film 22 is formed using the ALD method.

[0164] The dielectric film 22 is formed under a temperature condition of, for example, 150° C. or higher and 400° C. or lower, although this varies depending on the film forming method and the film forming material.

[0165] Next, if Figure 6 As shown in FIG. 1 , in step S11, a first resist film is formed. Figure 14 As shown, the first resist film 24 is formed so as to cover the portion of the dielectric film 22 formed in step S10 that covers the surface of the partition wall portion 18 and the vicinity thereof.

[0166] The method for forming the first resist film 24 is not particularly limited. In this embodiment, a photosensitive liquid resist is uniformly applied to a predetermined surface of the dielectric film 22 by spin coating, and partially exposed using a photomask. The first resist film 24 is then formed by immersing the film in a developer to remove unnecessary photosensitive liquid resist, and then drying the remaining photosensitive liquid resist in an oven or the like.

[0167] Next, if Figure 6 As shown, in step S12, a conductive film is formed. In more detail, as Figure 15 As shown, the conductive film 23 is formed so as to cover the dielectric film 22 formed in step S10 and the first resist film 24 formed in step S11 .

[0168] Here, the method for forming the conductive film 23 is not particularly limited as described above, but it is preferable to use the ALD method. If the ALD method is used, the raw material of the conductive film 23 can be supplied by gas, so the material can be selected and the film thickness can be adjusted at the atomic layer level. Therefore, even when the fine pores provided inside the metal porous body 21 are extremely small, a homogeneous and dense conductive film 23 can be formed. In addition, if the ALD method is used, the dielectric film 22 provided inside the first through hole 11 of the insulating substrate 10 can also be easily covered with the conductive film 23. In addition, although the formation of the conductive film 23 varies depending on the film forming method and the film forming material, it is carried out, for example, under temperature conditions of not less than 200°C and not more than 600°C.

[0169] Next, if Figure 6 As shown in FIG. 1 , in step S13, the first resist film is peeled off. Figure 16 As shown, the first resist film 24 and the conductive film 23 formed on the surface of the first resist film 24 are peeled off using a stripping liquid or the like. By peeling off a portion of the conductive film 23 in this manner, a discontinuous portion is formed in the conductive film 23 at that portion.

[0170] Next, if Figure 6 As shown in FIG. 1 , in step S14, a second resist film is formed. Figure 17 As shown, the second resist film 25 is formed so as to cover the portion of the dielectric film 22 exposed to the outside by peeling off the first resist film 24, and the portion of the conductive film 23 other than the portion formed at the position corresponding to the plurality of metal wall grooves 15h. The method for forming the second resist film 25 is the same as the method for forming the first resist film 24 described above.

[0171] By forming the second resist film 25 in this manner, it is possible to prevent the base material constituting the metal wall portion from being unintentionally formed in portions other than the metal wall portion groove 15 h in the metal wall portion forming step described later.

[0172] Next, if Figure 6 As shown, in step S15, a metal wall portion is formed. In more detail, as Figure 18 As shown, two metal wall portions 15 are formed so as to fill the two metal wall grooves 15h. The two metal wall portions 15 are provided upright from the first main surface 10a toward the capacitor forming portion 20. Furthermore, the metal wall portion located on the first external connection wiring side of these two metal wall portions 15 corresponds to the aforementioned metal wall portion 15A, and the metal wall portion located closer to the second external connection wiring side than the metal wall portion 15A corresponds to the metal wall portion 15B.

[0173] The metal wall portion 15 formed in this manner is bonded to the portion of the conductive film 23 formed at the position corresponding to the metal wall portion groove 15h. As a result, in this embodiment, the metal wall portion 15A is bonded to the adjacent conductive films 23B and 23C, and the metal wall portion 15B is bonded to the adjacent conductive films 23D and 23E.

[0174] Here, the metal wall portion 15 can be formed by a thick film forming method such as electrolytic plating or screen printing. In this embodiment, the metal wall portion 15 containing Cu is formed by electrolytic plating.

[0175] Next, if Figure 6 As shown in FIG. 1 , in step S16, the second resist film is peeled off. Figure 19 As shown, the second resist film 25 is peeled off by using a peeling liquid or the like.

[0176] Next, if Figure 6 As shown, in step S17, a sealing portion is formed. In more detail, as Figure 20 As shown, a sealing portion 30 is provided on the first main surface 10 a of the insulating substrate 10 on which the capacitance forming portion 20 is provided so as to cover the capacitance forming portion 20 .

[0177] The sealing portion 30 is formed, for example, by so-called compression molding. More specifically, a resin sheet is coated on the first main surface 10a of the insulating substrate 10, and in this state, a vacuum is drawn using a vacuum laminator to bring the resin sheet into close contact with the first main surface 10a of the insulating substrate 10. Then, in this state, the capacitor forming portion 20 is laminated by heating the resin sheet at 50°C to 100°C, and then, the resin sheet is heated to 100°C to 200°C for formal curing, thereby forming the sealing portion 30. In addition, the method for forming the sealing portion 30 is not limited to the above-mentioned compression molding, and can also be performed by so-called transfer molding.

[0178] Thus, the capacitor forming portion 20 is sealed by the insulating substrate 10 and the sealing portion 30, which can prevent the intrusion of moisture from the outside to the capacitor forming portion 20 and ensure moisture resistance. In addition, the capacitor forming portion 20 is covered by the sealing portion 30, and the capacitor forming portion 20 is also physically protected by the sealing portion 30. In addition, the curing conditions shown in the above are only an example and can be variously changed.

[0179] Next, if Figure 6 As shown in FIG. 1 , in step S18, the insulating substrate is subjected to a grinding process. Figure 21 As shown, the planar cutting is performed on the second main surface 10 b side of the insulating substrate 10 located on the side opposite to the side where the capacitance forming portion 20 is provided.

[0180] During the grinding process, a grinding tape (not shown) is attached to the capacitor forming portion 20, and the portion of the insulating substrate 10 that blocks the second via-hole conductor 14 and the first through-hole 11 is removed by planar grinding. As a result, the end of the second via-hole conductor 14 is exposed on the second main surface 10b.

[0181] Next, if Figure 6 As shown, in step S19, the insulating substrate is singulated. Figure 22 As shown, by dividing the insulating substrate 10 , a plurality of capacitors 1A connected to each other are separated into individual pieces.

[0182] Here, during singulation, a groove is formed in at least one of the insulating substrate 10 and the sealing portion 30, and a force is applied to the insulating substrate 10 and the sealing portion 30 to bend them starting from the groove, thereby breaking the insulating substrate 10 and the sealing portion 30. The grooves can be formed using diamond scribing, laser scribing, or cutting. Alternatively, singulation can be performed by directly cutting the insulating substrate 10 and the sealing portion 30 by scribing or cutting.

[0183] Next, if Figure 6 As shown in FIG. 1 , in step S20, a first via conductor is formed on the insulating substrate. Figure 23 As shown, the first via-hole conductor 13 is formed so as to fill the first through-hole 11 provided in the insulating substrate 10 .

[0184] The first via-hole conductor 13 can be formed, for example, by electroplating. In this case, the portion other than the first through-hole 11 is covered with a UV-curable resin film (not shown) as a mask. By performing electroplating in this state, only the interior of the first through-hole 11 can be covered with the plated film. After the electroplating is completed, the UV-curable resin film serving as a mask is removed.

[0185] The first via-hole conductor 13 formed in this manner is bonded to the conductive film 23 at its side surface and at the end surface of the first via-hole conductor 13 on the side of the capacitance forming portion 20 (see FIG. Figure 4 ). Thus, the first via-hole conductor 13 is connected to the capacitance forming portion 20 via the conductive film 23 covering the first via-hole conductor 13 .

[0186] Next, if Figure 6 As shown in FIG. 2 , in step S21, a first bump and a second bump are formed on the insulating substrate. Figure 2 As shown, the first bumps 16 and the second bumps 17 are formed on the second main surface 10 b of the insulating substrate 10 so as to cover the first via-hole conductors 13 and the second via-hole conductors 14 provided on the insulating substrate 10 .

[0187] The first bumps 16 and the second bumps 17 can be formed simultaneously by, for example, electroplating. In this case, a UV-curable resin film (not shown) is used as a mask to cover the portions of the first and second via-hole conductors 13 and 14 except for the exposed portions. Electroplating is then performed in this state, thereby allowing the first and second bumps 16 and 17 to protrude from the second main surface 10b. After the electroplating is completed, the UV-curable resin film is removed as a mask.

[0188] Furthermore, the second via conductor 14, first bump 16, and second bump 17 can be formed not only by the aforementioned electrolytic plating method but also by a combination of a screen printing method, an inkjet method, a dispenser method, or the like using a conductive paste and firing. In this case, it is preferable that the conductive paste contain a metal that can be fired at a low temperature and a sintering aid so that firing can be performed at a temperature that does not affect the resin constituting the sealing portion 30.

[0189] By going through the process of steps S1 to S21 described above, the capacitor 1A involved in the above-mentioned embodiment 1 is manufactured, that is, the capacitor in which the capacitance forming part 20A, the capacitance forming part 20B, the capacitance forming part 20C, the capacitance forming part 20D and the capacitance forming part 20E are electrically connected in series in sequence.

[0190] In the above-described method of manufacturing capacitor 1A according to the present embodiment, the case where the polishing process is performed after the sealing portion is formed is exemplified, but the sealing portion may be formed after the polishing process is performed. Furthermore, the polishing process may be performed after the individual pieces are formed.

[0191] Here, in the capacitor 1A according to the present embodiment, as described above, the conductive film 23 includes the mutually discontinuous conductive film 23A and the conductive film 23B, so that the capacitance-forming portion 20 is configured to include the capacitance-forming portion 20A defined by the conductive film 23A, the dielectric film 22A, and the porous metal body 21A, and the capacitance-forming portion 20B defined by the conductive film 23B, the dielectric film 22B, and the porous metal body 21B. Furthermore, the capacitance-forming portions 20B to 20E are electrically connected to the first external connection wiring via the capacitance-forming portion 20A, and the capacitance-forming portion 20A is electrically connected to the second external connection wiring via the capacitance-forming portion 20B to 20E. As a result, the capacitance-forming portion 20A and the capacitance-forming portions 20B to 20E are electrically connected in series between the first external connection wiring and the second external connection wiring via the partition portion 18A.

[0192] By providing portions where the conductive film 23 is discontinuously formed in this manner, the capacitance forming portion 20 is divided into a plurality of portions, and these divided capacitance forming portions are electrically connected in series, thereby improving the withstand voltage of the capacitor 1A.

[0193] That is, when a voltage is applied to a capacitor having a single capacitance forming portion and an electric field concentration occurs in the single capacitance forming portion, the capacitor function is immediately impaired due to a short circuit.

[0194] In this regard, in the capacitor 1A of this embodiment, the capacitance forming portion 20 is divided into a plurality of portions, and these divided capacitance forming portions are electrically connected in series. This configuration allows the electric field generated when a voltage is applied to the capacitor 1A to be concentrated and dispersed to each of the divided capacitance forming portions, thereby improving the withstand voltage of the capacitor 1A. Consequently, the reliability of the capacitor 1A after installation can be improved.

[0195] Furthermore, by dividing capacitance-forming portion 20 into a plurality of parts and electrically connecting them in series as described above, even if electric field concentration occurs in a portion of capacitance-forming portion 20 and the part short-circuits (i.e., if the voltage is damaged), an amount of electrostatic capacitance corresponding to the remaining capacitance-forming portion 20 can be maintained as the electrostatic capacitance of capacitor 1A. Therefore, capacitor 1A can maintain a certain electrostatic capacitance even after voltage damage, achieving improved reliability after mounting.

[0196] Therefore, by using capacitor 1A according to this embodiment, it is possible to improve reliability after mounting in a capacitor including capacitance-forming portion 20 including porous metal body 21 , dielectric film 22 , and conductive film 23 .

[0197] The effect of improving the withstand voltage of the capacitor 1A described above can be confirmed by a verification test 1 described later.

[0198] Furthermore, in capacitor 1A according to this embodiment, the volume of the porous metal body of any one of capacitance-forming portions 20A to 20E may be smaller than the volume of the porous metal bodies of the other adjacent capacitance-forming portions, and the thickness of the dielectric film of that capacitance-forming portion may be thinner than the thickness of the dielectric films of the other capacitance-forming portions. In this case, electric field concentration can be intentionally facilitated in the capacitance-forming portion where the capacitance is reduced by reducing the volume of the porous metal body, thereby maximizing the capacitance of capacitor 1A after voltage damage.

[0199] Furthermore, when manufacturing a plurality of capacitors 1A in which the thickness of the dielectric film 22 varies among the capacitance-forming portions as described above, a resist film may be formed between step S10 (i.e., formation of the dielectric film) and step S11 (i.e., formation of the first resist film) so as to cover the dielectric film 22 except for the thickened portion. In this state, the dielectric film 22 may be formed again, and then the resist film may be peeled off.

[0200] Furthermore, in capacitor 1A according to the present embodiment, as described above, partition wall portion 18 is bonded to a portion of porous metal body 21 of capacitance-forming portion 20 while standing from first main surface 10 a toward capacitance-forming portion 20 .

[0201] With this configuration, if stress resulting from the difference in thermal expansion coefficients between insulating substrate 10 and capacitance-forming portion 20 causes warping in insulating substrate 10 during the manufacturing process involving heat treatment of capacitor 1A (i.e., the firing process, the dielectric film formation process, and the conductive film formation process), the so-called anchoring effect achieved by partition wall portion 18 can suppress the warping of insulating substrate 10 and effectively prevent the dielectric film 22 and conductive film 23 from peeling off from insulating substrate 10 due to the warping. This improves the mounting stability and post-mount reliability of capacitor 1A.

[0202] Furthermore, in capacitor 1A according to this embodiment, a plurality of partition walls 18 are provided. This further suppresses warping of insulating substrate 10. The effect of providing partition walls 18 on suppressing warping of insulating substrate 10 was confirmed in Verification Test 2, described below.

[0203] Furthermore, in capacitor 1A according to this embodiment, as described above, capacitance-forming portion 20 is not substantially directly bonded to insulating substrate 10 , or even if directly bonded, is only slightly bonded to insulating substrate 10 . This also suppresses warping of insulating substrate 10 .

[0204] Furthermore, in the capacitor 1A according to the present embodiment, as described above, the plurality of metal walls 15 are bonded to a portion of the conductive film 23 of the capacitance-forming portion 20 while being arranged upright from the first main surface 10a toward the capacitance-forming portion 20. These plurality of metal walls 15 provide an anchoring effect, similar to that of the partition walls 18, thereby suppressing warpage in the insulating substrate 10 described above. The effect of suppressing warpage in the insulating substrate 10 by providing the metal walls 15 was confirmed by Verification Test 2, described later.

[0205] Furthermore, in capacitor 1A according to this embodiment, the distance between partition wall 18A and first via-hole conductor 13 is configured to be shorter than the distance between partition wall 18A and metal wall 15A, thereby separating partition wall 18A and metal wall 15A by a considerable distance. This further suppresses warping of insulating substrate 10. Similarly, the distance between metal wall 15B and second via-hole conductor 14 is configured to be shorter than the distance between metal wall 15B and partition wall 18B, thereby separating metal wall 15B and partition wall 18B by a considerable distance. This further suppresses warping of insulating substrate 10.

[0206] Furthermore, in the capacitor 1A according to the present embodiment, as described above, both the first via-hole conductor 13 and the second via-hole conductor 14 are provided in the 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 .

[0207] In this configuration, neither the first external connection wiring nor the second external connection wiring is disposed to the side of the capacitance forming portion 20. Therefore, the portion of the sealing portion 30 located to the side of the capacitance forming portion 20 can be minimized. Consequently, not only can the capacitor 1A be made smaller than conventional capacitors, but the volume occupied by portions of the capacitor 1A other than the capacitance forming portion 20 is also reduced, thereby achieving higher capacitance.

[0208] Furthermore, in the above-described configuration, the first and second via-hole conductors 13 and 14 are arranged to penetrate the insulating substrate 10 in its thickness direction. Therefore, these via-hole conductors of different polarities are positioned close together, with their current paths oriented in opposite directions. Consequently, the magnetic fields generated in these via-hole conductors by the flow of current cancel each other out, thereby reducing the so-called ESL (equivalent series inductance).

[0209] Furthermore, in the capacitor 1A according to the present embodiment, as described above, at the boundary between the first via-hole conductor 13 and the base material of the insulating substrate 10 , the base material of the insulating substrate 10 is covered with the dielectric film 22 , the dielectric film 22 is covered with the conductive film 23 , and the conductive film 23 is further covered with the first via-hole conductor 13 .

[0210] This configuration improves the adhesion between the base material of the insulating substrate 10 and the first via-hole conductor 13 compared to a case where the base material of the insulating substrate 10 and the first via-hole conductor 13 are directly bonded, thereby suppressing the intrusion of moisture through this portion. Consequently, a capacitor with excellent moisture resistance can be achieved.

[0211] Furthermore, in capacitor 1A according to this embodiment, as described above, porous metal body 21 is formed from a sintered body of metal particles. With this configuration, the mechanical strength of capacitance-forming portion 20 is improved by metallic bonding between the metal particles. Furthermore, the bonding area between the metal particles is increased, thereby achieving a so-called low ESR (equivalent series resistance). Furthermore, this also makes it relatively easy to form a porous metal body having open pores.

[0212] Here, in the capacitor 1A involved in this embodiment, it is also possible to configure such that, when the electrostatic capacitance of any one of the capacitance forming sections 20A to 20E is compared with the electrostatic capacitance of the remaining capacitance forming sections, the electrostatic capacitance of the capacitance forming section is 5% or more and 50% or less of the electrostatic capacitance of the remaining capacitance forming sections. In other words, in the capacitor 1A, the capacitance forming section 20 can be divided so that the electrostatic capacitance of these five capacitance forming sections 20A to 20E is substantially equal. In this case, even if a short circuit occurs in any of the capacitance forming sections, the change in the electrostatic capacitance of the capacitor 1A before and after the short circuit can be made to be the same.

[0213] Furthermore, in capacitor 1A according to this embodiment, the thickness of the dielectric film of any one of capacitance-forming portions 20A to 20E may be at least twice the thickness of the dielectric film of the other adjacent capacitance-forming portions. With this configuration, electric field concentration is less likely to occur in the capacitance-forming portion having a thicker dielectric film.

[0214] (Implementation Method 2)

[0215] Figure 24 Schematic cross-sectional view of the capacitor according to Embodiment 2. Figure 24 , capacitor 1B according to this embodiment will be described.

[0216] like Figure 24 As shown, capacitor 1B according to the present embodiment differs from capacitor 1A according to the first embodiment in that metal wall portion 15 is single and the number of divisions of capacitance forming portion 20 is different.

[0217] More specifically, in the capacitor 1B according to the present embodiment, the first external connection wiring side is directed toward the second external connection wiring side (ie, from the Figure 24 The partition wall portion 18C, the metal wall portion 15C, and the partition wall portion 18D are arranged in this order (from the right side to the left side).

[0218] Thus, in the present embodiment, the capacitor forming portion 20 is divided into four. For the sake of convenience, starting from the capacitor forming portion closest to the first external connection wiring, these four capacitor forming portions are referred to as the capacitor forming portion 20F, the capacitor forming portion 20G, the capacitor forming portion 20H, and the capacitor forming portion 20I in sequence. In addition, in the present embodiment, the capacitor forming portion 20F corresponds to the first capacitor forming portion, and the capacitor forming portions 20G to 20I correspond to the second capacitor forming portion. In addition, the capacitor forming portion 20G corresponds to the third capacitor forming portion, and the capacitor forming portions 20H and 20I correspond to the fourth capacitor forming portion. Furthermore, the capacitor forming portion 20H corresponds to the fifth capacitor forming portion, and the capacitor forming portion 20I corresponds to the sixth capacitor forming portion.

[0219] In the present embodiment, the partition wall portion 18C and the partition wall portion 18D correspond to the first partition wall portion and the second partition wall portion, respectively, and the metal wall portion 15C corresponds to the first metal wall portion.

[0220] Here, the relationship between the partition wall portion 18C and the capacitance forming portion 20F and the capacitance forming portion 20G is the same as the relationship between the partition wall portion 18A and the capacitance forming portion 20A and the capacitance forming portion 20B in the above-mentioned embodiment 1. In addition, the relationship between the metal wall portion 15C and the capacitance forming portion 20G and the capacitance forming portion 20H is the same as the relationship between the metal wall portion 15A and the capacitance forming portion 20B and the capacitance forming portion 20C in the above-mentioned embodiment 1. Furthermore, the relationship between the partition wall portion 18D and the capacitance forming portion 20H and the capacitance forming portion 20I is the same as the relationship between the partition wall portion 18B and the capacitance forming portion 20C and the capacitance forming portion 20D in the above-mentioned embodiment 1.

[0221] In the capacitor 1B, the second via-hole conductor 14 is bonded to the conductive film 23 of the capacitance forming portion 20. More specifically, the second via-hole conductor 14 is bonded to the conductive film 23I of the capacitance forming portion 20I.

[0222] With the above configuration, in capacitor 1B according to the present embodiment, capacitance forming portion 20F, capacitance forming portion 20G, capacitance forming portion 20H, and capacitance forming portion 20I are electrically connected in series in this order between the first external connection wiring and the second external connection wiring.

[0223] Even with such a configuration, the same effects as those described in the first embodiment can be obtained, and in the capacitor having the capacitance forming portion 20 including the porous metal body 21 , the dielectric film 22 , and the conductive film 23 , improved reliability after mounting can be achieved.

[0224] Note that capacitor 1B according to this embodiment can be manufactured by a method according to the method for manufacturing capacitor 1A according to the first embodiment described above.

[0225] (Implementation Method 3)

[0226] Figure 25 Schematic cross-sectional view of a capacitor according to Embodiment 3. Figure 25 , the capacitor 1C involved in this embodiment is described.

[0227] like Figure 25 As shown, capacitor 1C according to the present embodiment differs from capacitor 1A according to the first embodiment in that a single partition wall 18 is provided and metal wall 15 is not provided, thereby making the number of divisions of capacitance forming portion 20 different.

[0228] In more detail, in the capacitor 1C involved in this embodiment, when observed along the normal direction of the first main surface 10a, one partition wall portion 18E is located between the first external connection wiring and the second external connection wiring. Thus, in the capacitor 1C, the capacitor forming portion 20 is divided into two. For ease of explanation, starting from the capacitor forming portion closest to the first external connection wiring, these two capacitor forming portions are referred to as capacitor forming portion 20J and capacitor forming portion 20K in sequence. In addition, in this embodiment, the capacitor forming portion 20J corresponds to the first capacitor forming portion, and the capacitor forming portion 20K corresponds to the second capacitor forming portion. In addition, the partition wall portion 18E corresponds to the first partition wall portion.

[0229] Here, the relationship between the partition wall portion 18E and the capacitance forming portion 20J and the capacitance forming portion 20K is the same as the relationship between the partition wall portion 18A and the capacitance forming portion 20A and the capacitance forming portion 20B in the first embodiment described above.

[0230] Furthermore, in the capacitor 1C, the second via-hole conductor 14 is bonded to the conductive film 23 of the capacitance forming portion 20. More specifically, the second via-hole conductor 14 is bonded to the conductive film 23K of the capacitance forming portion 20K.

[0231] With the above configuration, in the capacitor 1C according to the present embodiment, the capacitance forming portion 20J and the capacitance forming portion 20K are electrically connected in series between the first external connection wiring and the second external connection wiring in this order.

[0232] Even with such a configuration, the same effects as those described in the first embodiment can be obtained, and in the capacitor having the capacitance forming portion 20 including the porous metal body 21 , the dielectric film 22 , and the conductive film 23 , improved reliability after mounting can be achieved.

[0233] Furthermore, the capacitor 1C according to this embodiment can be manufactured by removing the steps related to the metal wall portion (ie, Figure 6The method is used to manufacture the product according to steps S8, S14 to S16 in the manufacturing process.

[0234] (Verification Test 1)

[0235] In verification test 1, multiple capacitors with different numbers of metal walls and partitions (i.e., the number of divisions of the capacitor forming part) were prepared. By measuring the withstand voltage when voltage was applied to these capacitors, the effect of dividing the capacitor forming part and connecting them in series on the withstand voltage of the capacitor was verified.

[0236] In the verification test 1, a capacitor having a capacitor forming part divided into two by providing one metal wall (hereinafter referred to as a 2-continuous type for the sake of convenience), a capacitor having a capacitor forming part divided into four by providing two metal walls and one partition wall (a 4-continuous type), a capacitor having a capacitor forming part divided into six by providing three metal walls and two partition walls (a 6-continuous type), and a capacitor having a capacitor forming part divided into eight by providing four metal walls and three partition walls (an 8-continuous type), were prepared. In addition, as a comparative example, a capacitor having no capacitor forming part divided (i.e., no metal wall or partition wall was provided) was prepared. In addition, the above-mentioned 4-continuous type capacitor has the same characteristics as the capacitor 1B involved in the above-mentioned embodiment 2 (see Figure 24 In addition, in the above-mentioned 6-continuous type and 8-continuous type capacitors, the metal wall portions and the partition portions are alternately arranged from the first external connection wiring side toward the second external connection wiring side.

[0237] The insulating substrate of the capacitor prepared in Verification Test 1 contains Al2O3 and is an insulating substrate with a size of 1000 μm square and a thickness of 75 μm. The first via conductor and the second via conductor contain Ni and are cylindrical via conductors with a diameter of 150 μm and an axial length of 75 μm. The distance between the first via conductor 13 and the second via conductor 14 is 150 μm. The first bump 16 and the second bump 17 contain Au. The metal porous body contains Ni and is a metal porous body with a size of 1000 μm square and a thickness of 200 μm before the capacitor forming portion is divided. The dielectric film uses a dielectric film containing AlSiO, and the conductive film uses a conductive film containing TiN.

[0238] In addition, the metal wall prepared in the verification test 1 contains Cu and is of height ( Figure 2 The vertical dimension in the middle is 200 μm, the thickness is ( Figure 2 The left and right dimensions are 70 μm, the width ( Figure 2The metal wall portion (dimension in a direction perpendicular to the paper surface) is 1000 μm. The partition wall portion is made of Ni and has a height of 200 μm, a thickness of 70 μm, and a width of 1000 μm.

[0239] The effect of dividing the capacitance forming portion and connecting them in series on the withstand voltage of the capacitor was verified using a withstand voltage tester (B1500A, manufactured by Keysight) using the method described below. Five samples of the various capacitors described above were used in this verification.

[0240] First, connect the capacitor's terminals to the terminals of a withstand voltage tester. Next, apply voltage to the capacitor at a current of 0.05A and a voltage ramp rate of 0.67mV / second. The voltage at which the current falls below 0.05A is measured as the withstand voltage.

[0241] Figure 26 1 is a graph showing the result of the verification test 1 performed by the above-mentioned method. The withstand voltage of various capacitors is shown in the graph. The result of the verification test 1 is that, by arranging the partition wall portion to divide the capacitance forming portion and connect them in series, the withstand voltage of the capacitor is improved compared with the single case (that is, the case of the comparative example) in which the capacitance forming portion is not divided. Furthermore, it is known that by increasing the number of metal wall portions and partition wall portions so as to increase the number of capacitance forming portions electrically connected in series (that is, the number of divisions of the capacitance forming portion), the effect of improving the withstand voltage of the capacitor becomes more significant. According to the above, it is known that by dividing the capacitance forming portion and connecting them in series, the withstand voltage of the capacitor is improved.

[0242] (Verification Test 2)

[0243] In Verification Test 2, various capacitors with varying numbers of metal walls and partitions (i.e., the number of divisions in the capacitance-forming portion) were prepared. The deflection of the insulating substrate when a load was applied to these capacitors was determined, thereby verifying the effect of the metal walls and partitions on the flexural strength (mechanical strength) of the capacitors. The types of capacitors prepared in Verification Test 2 were the same as those used in Verification Test 1.

[0244] The effects of the metal walls and partitions on the flexural strength of the capacitors were verified using a flexure tester (DFT-30, manufactured by Hikari Denki Co., Ltd.) using the following method. Five samples of the various capacitors described above were used for this verification.

[0245] First, a glass epoxy substrate with a long side length of 100 mm, a short side length of 40 mm, and a thickness of 1.6 mm was prepared. Next, a 10 μm thick solder paste was printed on the lands of the glass epoxy substrate using a metal mask. Capacitors were then mounted on the lands with the printed solder paste and heat-treated at 250°C for 15 minutes.

[0246] Next, place the epoxy glass substrate with the capacitor mounted on it on the loading platform of the flexure test device. Next, make the terminal for measuring the capacitance of the capacitor contact the connection pad of the epoxy glass substrate. The measurement frequency of the capacitor capacitance is set to 1kHz. Next, pressurize the epoxy glass substrate by placing a pressurizing fixture against the main surface of the pair of main surfaces of the epoxy glass substrate on the side where the capacitor is not mounted. Under the pressurizing conditions, the lifting speed of the pressurizing fixture is set to 0.1mm / second and the load is set to 0.003N.

[0247] Next, by applying pressure, the deflection of the capacitor was measured when the capacitance of the capacitor became less than 10% of the capacitance before the pressure application (i.e., when the capacitor was short-circuited). The deflection means the displacement of the central portion of the insulating substrate from the initial position along the normal direction of the first main surface of the insulating substrate when viewed from above (i.e., the displacement along the normal direction of the first main surface of the insulating substrate). Figure 2 displacement in the up and down directions).

[0248] Figure 27 : is a coordinate graph showing the results of verification test 2 performed by the above-mentioned method. In this coordinate graph, the deflection of various capacitors is shown. The result of verification test 2 shows that by providing the partition wall portion on the insulating substrate, the deflection of the insulating substrate is increased compared to the case where the metal wall portion is not provided (i.e., the case of the comparative example). Furthermore, it can be seen that by increasing the number of metal walls and partition walls, the effect of increasing the deflection becomes more significant. As shown in this way, from the fact that the deflection increases when a short circuit occurs due to the application of external force to the capacitor, it can be seen that the bending strength of the capacitor is improved by providing the metal wall portion and the partition wall portion.

[0249] (Note)

[0250] The characteristic structures of the capacitors disclosed in the above-described embodiments can be summarized as follows.

[0251] [Note 1]

[0252] A capacitor comprising:

[0253] an insulating substrate having a first main surface and a second main surface located on a side opposite to the first main surface;

[0254] a capacitor forming portion disposed opposite to the first main surface; and

[0255] The first external connection wiring and the second external connection wiring are connected to the capacitor forming portion.

[0256] The capacitor forming portion includes a conductive porous metal body, a dielectric film covering a surface of the porous metal body, and a conductive film covering the dielectric film.

[0257] Since the conductive film includes a first conductive film and a second conductive film that are discontinuous with each other, the capacitance forming portion includes a first capacitance forming portion and a second capacitance forming portion. The first capacitance forming portion is defined by the first conductive film, the first dielectric film as a portion of the dielectric film corresponding to the first conductive film, and the first porous metal body as a portion of the porous metal body corresponding to the first dielectric film. The second capacitance forming portion is defined by the second conductive film, the second dielectric film as a portion of the dielectric film corresponding to the second conductive film, and the second porous metal body as a portion of the porous metal body corresponding to the second dielectric film.

[0258] The second capacitance forming portion is located on the side opposite to the first external connection wiring side when viewed from the first capacitance forming portion.

[0259] The second capacitor forming portion is electrically connected to the first external connection wiring via the first capacitor forming portion, and the first capacitor forming portion is electrically connected to the second external connection wiring via the second capacitor forming portion, so that at least the first capacitor forming portion and the second capacitor forming portion are electrically connected in series between the first external connection wiring and the second external connection wiring.

[0260] [Note 2]

[0261] The capacitor according to Supplementary Note 1, wherein:

[0262] further comprising: a first partition wall portion made of metal, dividing the metal porous body into the first metal porous body and the second metal porous body, dividing the dielectric film into the first dielectric film and the second dielectric film, and further dividing the conductive film into the first conductive film and the second conductive film,

[0263] The above-mentioned first partition wall portion is bonded to the above-mentioned first metal porous body and the above-mentioned second metal porous body, and is not bonded to the above-mentioned first conductive film and the above-mentioned second conductive film, thereby at least the above-mentioned first capacitor forming portion and the above-mentioned second capacitor forming portion are electrically connected in series between the above-mentioned first external connection wiring and the above-mentioned second external connection wiring via the above-mentioned first partition wall portion.

[0264] [Note 3]

[0265] The capacitor according to Supplementary Note 2, wherein:

[0266] The first partition wall portion is provided upright from the first main surface.

[0267] [Note 4]

[0268] The capacitor according to Supplementary Note 2 or 3, wherein:

[0269] The thickness of the first partition wall portion is 5 μm or more.

[0270] [Note 5]

[0271] The capacitor according to Supplementary Note 4, wherein:

[0272] The thickness of the first partition wall portion is 75 μm or less.

[0273] [Note 6]

[0274] The capacitor according to any one of Supplementary Notes 2 to 5, wherein

[0275] A height of the first partition wall portion in a direction parallel to a normal direction of the first main surface is greater than a height of the capacitance forming portion in a direction parallel to the normal direction of the first main surface.

[0276] [Note 7]

[0277] The capacitor according to any one of Supplementary Notes 2 to 6, wherein

[0278] The width of the first partition wall portion in a direction intersecting both the thickness direction and the height direction of the first partition wall portion is larger than the width of the capacitance forming portion in a direction intersecting both the thickness direction and the height direction of the first partition wall portion.

[0279] [Note 8]

[0280] The capacitor according to any one of Supplementary Notes 1 to 7, wherein:

[0281] The thickness of the first dielectric film is at least twice the thickness of the second dielectric film, or the thickness of the second dielectric film is at least twice the thickness of the first dielectric film.

[0282] [Note 9]

[0283] The capacitor according to any one of Supplementary Notes 1 to 7, wherein:

[0284] The electrostatic capacitance of the first capacitance forming portion is not less than 5% and not more than 50% of the electrostatic capacitance of the second capacitance forming portion.

[0285] [Note 10]

[0286] The capacitor according to any one of Supplementary Notes 1 to 9, wherein:

[0287] The first external connection wiring has a first via conductor that penetrates the insulating substrate so as to reach from the first main surface to the second main surface.

[0288] The second external connection wiring has a second via conductor that penetrates the insulating substrate so as to reach from the first main surface to the second main surface.

[0289] When viewed along a normal direction of the first main surface, the first via-hole conductor is provided in a region where the first capacitance forming portion is arranged.

[0290] The second via-hole conductor is provided in a region where the second capacitance forming portion is arranged when viewed along a normal direction of the first main surface.

[0291] [Note 11]

[0292] The capacitor according to any one of Supplementary Notes 1 to 10, wherein

[0293] further comprising: a first metal wall portion that divides the second capacitor forming portion so that the second capacitor forming portion includes a third capacitor forming portion located on the first external connection wiring side and a fourth capacitor forming portion located closer to the second external connection wiring side than the third capacitor forming portion;

[0294] The third capacitance forming portion includes a third metal porous body as a portion of the second metal porous body defining the third capacitance forming portion, a third dielectric film as a portion of the second dielectric film corresponding to the third metal porous body, and a third conductive film as a portion of the second conductive film corresponding to the third dielectric film.

[0295] The fourth capacitance forming portion includes a fourth metal porous body as a portion of the second metal porous body defining the fourth capacitance forming portion, a fourth dielectric film as a portion of the second dielectric film corresponding to the fourth metal porous body, and a fourth conductive film as a portion of the second conductive film corresponding to the fourth dielectric film.

[0296] The above-mentioned first metal wall portion is joined to the above-mentioned third conductive film and the above-mentioned fourth conductive film, so that the above-mentioned fourth capacitor forming portion is electrically connected to the above-mentioned first external connection wiring via the above-mentioned third capacitor forming portion, and the above-mentioned third capacitor forming portion is electrically connected to the above-mentioned second external connection wiring via the above-mentioned fourth capacitor forming portion, thereby at least the above-mentioned third capacitor forming portion and the above-mentioned fourth capacitor forming portion are electrically connected in series between the above-mentioned first external connection wiring and the above-mentioned second external connection wiring.

[0297] [Note 12]

[0298] The capacitor according to Supplementary Note 11, wherein:

[0299] Since the fourth conductive film includes a fifth conductive film and a sixth conductive film that are discontinuous with each other, the fourth capacitance-forming portion includes a fifth capacitance-forming portion and a sixth capacitance-forming portion. The fifth capacitance-forming portion is defined by the fifth conductive film, the fifth dielectric film serving as a portion of the fourth dielectric film corresponding to the fifth conductive film, and the fifth porous metal body serving as a portion of the fourth porous metal body corresponding to the fifth dielectric film. The sixth capacitance-forming portion is defined by the sixth conductive film, the sixth dielectric film serving as a portion of the fourth dielectric film corresponding to the sixth conductive film, and the sixth porous metal body serving as a portion of the fourth porous metal body corresponding to the sixth dielectric film.

[0300] The sixth capacitance forming portion is located on the side opposite to the first external connection wiring side when viewed from the fifth capacitance forming portion.

[0301] The above-mentioned 6th capacitor forming part is electrically connected to the above-mentioned 1st external connection wiring via the above-mentioned 5th capacitor forming part, and the above-mentioned 5th capacitor forming part is electrically connected to the above-mentioned 2nd external connection wiring via the above-mentioned 6th capacitor forming part, thereby at least the above-mentioned 5th capacitor forming part and the above-mentioned 6th capacitor forming part are electrically connected in series between the above-mentioned 1st external connection wiring and the above-mentioned 2nd external connection wiring.

[0302] [Note 13]

[0303] The capacitor according to Supplementary Note 12, wherein:

[0304] further comprising: a second partition wall portion made of metal, which divides the fourth metal porous body into the fifth metal porous body and the sixth metal porous body, and divides the fourth dielectric film into the fifth dielectric film and the sixth dielectric film, and further divides the fourth conductive film into the fifth conductive film and the sixth conductive film,

[0305] The above-mentioned second partition portion is bonded to the above-mentioned fifth metal porous body and the above-mentioned sixth metal porous body, and is not bonded to the above-mentioned fifth conductive film and the above-mentioned sixth conductive film, thereby at least the above-mentioned fifth capacitor forming portion and the above-mentioned sixth capacitor forming portion are electrically connected in series between the above-mentioned first external connection wiring and the above-mentioned second external connection wiring via the above-mentioned second partition portion.

[0306] [Note 14]

[0307] The capacitor according to Supplementary Note 12 or 13, wherein:

[0308] further comprising: a second metal wall portion that divides the sixth capacitor forming portion so that the sixth capacitor forming portion includes a seventh capacitor forming portion located on the first external connection wiring side and an eighth capacitor forming portion located closer to the second external connection wiring side than the seventh capacitor forming portion;

[0309] The seventh capacitance forming portion includes a seventh metal porous body as a portion of the sixth metal porous body defining the seventh capacitance forming portion, a seventh dielectric film as a portion of the sixth dielectric film corresponding to the seventh metal porous body, and a seventh conductive film as a portion of the sixth conductive film corresponding to the seventh dielectric film.

[0310] The eighth capacitance forming portion includes an eighth metal porous body as a portion of the sixth metal porous body defining the eighth capacitance forming portion, an eighth dielectric film as a portion of the sixth dielectric film corresponding to the eighth metal porous body, and an eighth conductive film as a portion of the sixth conductive film corresponding to the eighth dielectric film.

[0311] The above-mentioned second metal wall portion is joined to the above-mentioned seventh conductive film and the above-mentioned eighth conductive film, so that the above-mentioned eighth capacitor forming portion is electrically connected to the above-mentioned first external connection wiring via the above-mentioned seventh capacitor forming portion, and the above-mentioned seventh capacitor forming portion is electrically connected to the above-mentioned second external connection wiring via the above-mentioned eighth capacitor forming portion, thereby at least the above-mentioned seventh capacitor forming portion and the above-mentioned eighth capacitor forming portion are electrically connected in series between the above-mentioned first external connection wiring and the above-mentioned second external connection wiring.

[0312] (Other methods, etc.)

[0313] The shape, structure, size, number, material, etc. of each component shown in the above-mentioned embodiment of the present invention can be variously modified without departing from the gist of the present invention.

[0314] Furthermore, the characteristic structures shown in the above-mentioned embodiments of the present invention can of course be combined with each other within the scope permitted by the gist of the present invention.

[0315] As described above, the embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are encompassed.

[0316] Description of Reference Numerals

[0317] 1A to 1C capacitor, 10 insulating substrate, 10a first main surface, 10b second main surface, 11 first through-hole, 12 second through-hole, 13 first via conductor, 14 second via conductor, 15, 15A to 15C metal wall portion, 15h groove for metal wall portion, 16 first bump, 17 second bump, 18, 18A to 18E partition wall portion, 18h groove for partition wall portion, 20, 20A to 20K capacitor forming portion, 21, 21A to 21K porous metal body, 21a metal particles, 21b adhesive, 21p conductive paste, 22, 22A to 22K dielectric film, 23, 23A to 23K conductive film, 24 first resist film, 25 second resist film, 30 sealing portion, 30a outer surface.

Claims

1. A capacitor comprising: an insulating substrate having a first main surface and a second main surface located on a side opposite to the first main surface; a capacitance forming portion disposed opposite to the first main surface; and The first external connection wiring and the second external connection wiring are connected to the capacitance forming portion. The capacitance forming portion includes a conductive porous metal body, a dielectric film covering a surface of the porous metal body, and a conductive film covering the dielectric film. Since the conductive film includes a first conductive film and a second conductive film that are discontinuous with each other, the capacitance forming portion includes a first capacitance forming portion and a second capacitance forming portion, the first capacitance forming portion is defined by the first conductive film, the first dielectric film as a portion of the dielectric film corresponding to the first conductive film, and the first porous metal body as a portion of the porous metal body corresponding to the first dielectric film, and the second capacitance forming portion is defined by the second conductive film, the second dielectric film as a portion of the dielectric film corresponding to the second conductive film, and the second porous metal body as a portion of the porous metal body corresponding to the second dielectric film. The second capacitance forming portion is located on the side opposite to the first external connection wiring side when viewed from the first capacitance forming portion. The second capacitor forming portion is electrically connected to the first external connection wiring via the first capacitor forming portion, and the first capacitor forming portion is electrically connected to the second external connection wiring via the second capacitor forming portion, whereby at least the first capacitor forming portion and the second capacitor forming portion are electrically connected in series between the first external connection wiring and the second external connection wiring.

2. The capacitor according to claim 1, wherein further comprising: a metal partition wall portion that divides the metal porous body into the first metal porous body and the second metal porous body, divides the dielectric film into the first dielectric film and the second dielectric film, and further divides the conductive film into the first conductive film and the second conductive film, The partition portion is bonded to the first metal porous body and the second metal porous body, and is not bonded to the first conductive film and the second conductive film, whereby at least the first capacitor forming portion and the second capacitor forming portion are electrically connected in series between the first external connection wiring and the second external connection wiring via the partition portion.

3. The capacitor according to claim 2, wherein The partition wall portion is provided upright from the first main surface.

4. The capacitor according to claim 2 or 3, wherein: The thickness of the partition wall portion is 5 μm or more.

5. The capacitor according to claim 4, wherein The thickness of the partition wall portion is 75 μm or less.

6. The capacitor according to any one of claims 2 to 5, wherein A height of the partition portion in a direction parallel to a normal direction of the first main surface is greater than a height of the capacitance forming portion in a direction parallel to the normal direction of the first main surface.

7. The capacitor according to any one of claims 2 to 6, wherein: The width of the partition wall portion in a direction intersecting both the thickness direction and the height direction of the partition wall portion is greater than the width of the capacitance forming portion in a direction intersecting both the thickness direction and the height direction of the partition wall portion.

8. The capacitor according to any one of claims 1 to 7, wherein The thickness of the first dielectric film is at least twice the thickness of the second dielectric film, or the thickness of the second dielectric film is at least twice the thickness of the first dielectric film.

9. The capacitor according to any one of claims 1 to 7, wherein The electrostatic capacitance of the first capacitance forming portion is not less than 5% and not more than 50% of the electrostatic capacitance of the second capacitance forming portion.

10. The capacitor according to any one of claims 1 to 9, wherein The first external connection wiring has a first via conductor that penetrates the insulating substrate so as to reach from the first main surface to the second main surface. The second external connection wiring has a second via conductor that penetrates the insulating substrate so as to reach from the first main surface to the second main surface. When viewed along the normal direction of the first main surface, the first via-hole conductor is provided in a region where the first capacitance forming portion is arranged. When viewed along a normal direction of the first main surface, the second via-hole conductor is provided in a region where the second capacitance forming portion is arranged.

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