Capacitor, electric circuit, circuit board, device, capacitor member, and method for manufacturing capacitor

Abstract

This capacitor is provided with: a porous body that comprises a plurality of pores; and a conductor. The porous body comprises: a conductive base material; a first dielectric layer that is disposed on the base material; and a second dielectric layer that is disposed on the base material. The conductor is disposed on the first dielectric layer and the second dielectric layer. The first dielectric layer is disposed, in the porous body, in a first region that includes a boundary between the porous body and the outside of the porous body. The second dielectric layer is disposed in a second region that is located more inward of the porous body than the first region in the porous body.

Description

[Technical Field]

[0001] The present disclosure relates to a capacitor, an electric circuit, a circuit board, a device, a capacitor member, and a method for manufacturing a capacitor. [Background technology]

[0002] 2. Description of the Related Art Conventionally, capacitors have been known that include a dielectric layer formed by a vapor phase method such as atomic deposition.

[0003] For example, Patent Document 1 describes an electrolytic capacitor having a dielectric film formed on the surface of an anode foil facing a separator. This dielectric film is formed by atomic layer deposition.

[0004] Patent Document 2 describes an electrolytic capacitor including a predetermined electrode and at least one of an electrolytic solution and a solid electrolyte impregnated in the porous portion of the electrode. The porous portion of the electrode includes a porous body, a first dielectric layer covering at least a portion of the porous body, and a second dielectric layer covering at least a portion of the first dielectric layer. The porous body is formed integrally with the core portion from a first metal. The second dielectric layer is formed by atomic layer deposition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-43960 [Patent Document 2] International Publication No. 2018 / 180029 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides a capacitor that is advantageous in terms of voltage resistance and high capacitance. [Means for solving the problem]

[0007] The capacitor of the present disclosure comprises: a porous body including a plurality of pores; and a conductor.

[0008] The porous body is a conductive substrate; a first dielectric layer disposed on the substrate; a second dielectric layer disposed on the substrate.

[0009] the conductor is disposed on the first dielectric layer and the second dielectric layer; the first dielectric layer is disposed in a first region of the porous body that includes a boundary between the porous body and an outside of the porous body, The second dielectric layer is disposed in a second region of the porous body that is located more inward than the first region of the porous body. [Effects of the Invention]

[0010] According to the present disclosure, a capacitor is provided that is advantageous in terms of voltage resistance and high capacitance. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a capacitor according to the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the portion enclosed by the rectangle II in FIG. [Figure 3] FIG. 3 is a flowchart showing an example of a method for manufacturing a capacitor according to the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view showing another example of a capacitor according to the present disclosure. [Figure 5] FIG. 5 is a cross-sectional view showing yet another example of a capacitor according to the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view showing yet another example of a capacitor according to the present disclosure. [Figure 7] FIG. 7 is a cross-sectional view of the portion enclosed by rectangle VII in FIG. [Figure 8A]FIG. 8A is a diagram schematically illustrating an example of an electric circuit according to the present disclosure. [Figure 8B] FIG. 8B is a diagram schematically illustrating an example of a circuit board according to the present disclosure. [Figure 8C] FIG. 8C is a diagram schematically illustrating an example of the device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Findings that formed the basis of this disclosure) It is conceivable to obtain a capacitor by forming a dielectric layer on a porous and conductive substrate. According to the inventor's investigations, it has been found that when a dielectric layer is formed using a vapor phase method such as atomic deposition, as in the method for manufacturing an electrolytic capacitor described in Patent Document 1, it is difficult to form a dielectric layer on a substrate in an inner portion of the porous body that is the substrate. In the manufacture of a capacitor, since a conductor may be disposed even in an inner portion of such a porous body, it is thought that it is difficult to ensure the voltage resistance of the capacitor by only forming a dielectric layer using a vapor phase method.

[0013] As described above, the electrolytic capacitor described in Patent Document 2 includes a first dielectric layer that covers at least a portion of the porous body and a second dielectric layer that covers at least a portion of the first dielectric layer. The capacitance of a capacitor is inversely proportional to the thickness of the dielectric layer. Therefore, forming a second dielectric layer to cover the first dielectric layer, as in the electrolytic capacitor described in Patent Document 2, is not advantageous in terms of increasing the capacitance of the capacitor. In addition, there is a possibility that the formation of defect levels at the interface between the first and second dielectric layers may result in a decrease in voltage resistance, and that the dielectric layer may peel off due to internal stress caused by the difference in thermal expansion between the first and second dielectric layers.

[0014] In view of these circumstances, the present inventors have conducted extensive research into the configuration of a capacitor that is advantageous in terms of voltage resistance and high capacitance while including a porous body containing a conductive substrate. As a result, the present inventors have newly discovered that a capacitor can have a configuration that is advantageous in terms of voltage resistance and high capacitance by adjusting the dielectric layers formed on the substrate at different positions of the porous body, and have devised the capacitor of the present disclosure.

[0015] (Embodiment) Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.

[0016] FIG. 1 is a cross-sectional view showing an example of a capacitor according to the present disclosure. As shown in FIG. 1, a capacitor 1a includes a substrate 10, a first dielectric layer 21, a second dielectric layer 22, and a conductor 30. The substrate 10 is conductive. The first dielectric layer 21 and the second dielectric layer 22 are disposed on the substrate 10. The first dielectric layer 21 and the second dielectric layer 22 are in contact with the substrate 10. Note that a native oxide film may be formed on a conductive substrate. The first dielectric layer 21 and the second dielectric layer 22 are dielectric layers different from layers consisting only of a native oxide film. The substrate 10, the first dielectric layer 21, and the second dielectric layer 22 form a porous body 15. The porous body 15 has pores 15p extending inward. The first dielectric layer 21 is disposed in a first region 15a of the porous body 15. The first region 15a is a region including a boundary 16 between the porous body 15 and the outside. The second dielectric layer 22 is disposed in the second region 15b of the porous body 15. The second region 15b is a region of the porous body 15 located more inward than the first region 15a. With this configuration, the first dielectric layer 21 and the second dielectric layer 22 are disposed on the substrate 10 in the first region 15a and the second region 15b, respectively, so that the capacitor 1a is likely to have a desired withstand voltage. In addition, because both the first dielectric layer 21 and the second dielectric layer 22 are disposed on the substrate 10, the thickness of the dielectric layers is unlikely to increase, and the capacitor 1a is likely to have a high capacitance.

[0017] The first dielectric layer 21 is not limited to a specific dielectric layer. The first dielectric layer 21 includes, for example, a vapor deposition film. In this case, the relative permittivity of the material constituting the first dielectric layer 21 tends to be high, and the capacitor 1a tends to have a higher capacitance. In this specification, vapor deposition may include physical vapor deposition and chemical vapor deposition as described in Japanese Industrial Standard JIS H0211-1992. The first dielectric layer 21 may include a natural oxide film as a portion contacting the base material 10. The vapor deposition film may be a film formed by a vapor phase method. The vapor phase method is not limited to a specific vapor phase method. Examples of the vapor phase method are chemical vapor phase methods such as atomic layer deposition (ALD), chemical vapor deposition (CVD), and mist CVD.

[0018] The material of the first dielectric layer 21 is not limited to a specific material. The first dielectric layer 21 includes, for example, a metal compound. The metal compound includes, for example, at least one selected from the group consisting of metal oxides, metal nitrides, and metal oxynitrides. In addition, the metal compound includes at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and zinc. In this case, the capacitor 1a tends to have a desired breakdown voltage property more, and the capacitor 1a tends to have a higher capacitance more.

[0019] Examples of the metal oxide contained in the first dielectric layer 21 are HfO2, ZrO2, Hf 1-x Zr x O2, Al2O3, Ta2O5, TiO2, SiO2, and ZnO. x satisfies the condition of 0 < x < 1. Examples of the metal nitride contained in the first dielectric layer 21 are HfN, ZrN, Hf 1-x Zr x N, AlN, and SiN. Examples of the metal oxynitride contained in the first dielectric layer 21 are HfON, ZrON, HfZrON, AlON, and SiON.

[0020] The first dielectric layer 21 may further include at least one selected from the group consisting of yttrium, cerium, and gallium. In this case, the first dielectric layer 21 tends to have a higher relative permittivity.

[0021] The thickness of the first dielectric layer 21 is not limited to a specific value. The thickness is, for example, 5 nm or more. Thereby, the leakage current is suppressed, and the capacitor 1a is more likely to have a desired withstand voltage property. The thickness of the first dielectric layer 21 is, for example, 500 nm or less. Thereby, the capacitor 1a is more likely to have a high capacitance. The thickness of the first dielectric layer 21 may be 10 nm or more, and may also be 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 50 nm or less, or 20 nm or less.

[0022] The second dielectric layer 22 is not limited to a specific dielectric layer. The second dielectric layer 22 is, for example, a layer containing a dielectric of a type different from that of the first dielectric layer 21. The second dielectric layer 22 includes, for example, an anodic oxide film. In this case, even if the second portion 15b is away from the boundary 16, the second dielectric layer 22 is formed on the base material 10. In addition, the second dielectric layer 22 is likely to be uniformly formed with a desired thickness at the second portion 15b. Therefore, the capacitor 1a is more likely to have a desired withstand voltage property. The second dielectric layer 22 may include an oxide film other than a natural oxide film or an anodic oxide film. For example, the second dielectric layer 22 may include an oxide film formed by heat treatment in an oxidizing atmosphere.

[0023] The material of the second dielectric layer 22 is not limited to a specific material. The second dielectric layer 22 includes, for example, an oxide. The oxide includes, for example, at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and niobium. In this case, the capacitor 1a is more likely to have a desired withstand voltage property, and the capacitor 1a is more likely to have a high capacitance.

[0024] Examples of the oxide included in the second dielectric layer 22 are HfO2, ZrO2, Hf 1-x Zr x O2, Al2O3, Ta2O5, TiO2, SiO2, and Nb2O5. x satisfies the condition of 0 < x < 1. The second dielectric layer 22 preferably includes at least one selected from the group consisting of Al2O3 and Ta2O5. In this case, the capacitor 1a is more likely to have a desired withstand voltage property.

[0025] The thickness of the second dielectric layer 22 is not limited to a specific value. The thickness is, for example, 5 nm or more. This suppresses leakage current, making it easier for the capacitor 1a to have the desired voltage resistance. The thickness of the second dielectric layer 22 is, for example, 500 nm or less. This makes it easier for the capacitor 1a to have a high capacitance. The thickness of the second dielectric layer 22 may be 10 nm or more, or may be 400 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 50 nm or less, or 20 nm or less.

[0026] FIG. 2 is a cross-sectional view of the portion enclosed by rectangle II in FIG. 1. As shown in FIG. 2, the first dielectric layer 21 and the second dielectric layer 22 are in contact at the boundary between the first portion 15a and the second portion 15b. For example, when the first dielectric layer 21 includes a vapor-deposited film and the second dielectric layer 22 includes an anodized film, the edge of the first dielectric layer 21 may overlap the edge of the second dielectric layer 22. In vapor deposition, solid components derived from gaseous components adhere to the substrate to form a film. On the other hand, in anodization, an oxide film is formed by oxidizing a portion of the surface of the anode. Due to these differences in the film formation mechanisms, the edge of the first dielectric layer 21 including the vapor-deposited film may be positioned above the edge of the second dielectric layer 22 including the anodized film, as shown in FIG. 2.

[0027] The relative dielectric constant ε of the first dielectric layer 21 21 and the relative dielectric constant ε of the second dielectric layer 22 22 The relationship between the dielectric constant ε and the dielectric constant ε is not limited to a specific relationship. 21 and relative permittivity ε 22 For example, the relative permittivity ε 21 is the relative permittivity ε 22 In this case, the capacitor 1a is likely to have a higher capacitance than when the second dielectric layer 22 is disposed on the substrate 10 in the first portion 15a and the second portion 15b of the porous body 15.

[0028] 1, the substrate 10 includes, for example, a porous portion 11 and a core portion 12. The porous body 15 includes the porous portion 11. The core portion 12 is a non-porous portion.

[0029] The material of the substrate 10 is not limited to a specific material. The substrate 10 may include, for example, a valve metal. Examples of the valve metal include Al, Ta, Ti, Hf, Zr, Si, and Nb. In this case, the second dielectric layer 22 can be easily formed by a method such as anodization.

[0030] The valve metal contained in the substrate 10 may be aluminum. In this case, the porous portion 11 can be formed, for example, by electrolytic etching of an aluminum foil.

[0031] The substrate 10 may be a sintered metal body. In this case, the substrate 10 is likely to have the desired porosity, and the capacitor 1a is likely to have a high capacitance.

[0032] The metal contained in the metal sintered body is not limited to a specific metal, and the metal sintered body may contain, for example, tantalum.

[0033] The pore diameter of the pores in the porous portion 11 is not limited to a specific value. This pore diameter is, for example, 10 nm or more. This makes it easier for the specific surface area of ​​the porous portion 11 to be large, and the capacitor 1a to have a high capacitance. This pore diameter is, for example, 1 μm or less. This makes it easier to form the first dielectric layer 21, makes it easier for the first portion and the second portion to be arranged in a desired state, and makes it easier for the capacitor 1a to have a high capacitance. The pore diameter of the pores in the porous portion 11 may be 20 nm or more, 30 nm or more, 40 nm or more, or 50 nm or more, or may be 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, or 500 nm or less.

[0034] The dimension (depth) D1 of the first portion 15a in the direction perpendicular to the boundary 16 and the dimension (depth) D2 of the second portion 15b in the direction perpendicular to the boundary 16 are not limited to a specific relationship. The dimension D1 may be equal to or greater than the dimension D2. In this case, the volume of the first portion 15a in the volume of the porous body 15 tends to be large, and therefore the relative dielectric constant ε 21 is the relative permittivity ε 22 The higher it is, the more likely the capacitor 1a will have a high capacitance.

[0035] The dimension D1 may be less than the dimension D2. In this case, the volume of the first portion 15a in the volume of the porous body 15 tends to be small. Therefore, for example, when the first dielectric layer 21 is formed by vapor deposition and the second dielectric layer 22 is formed by anodization or heat treatment in an oxidizing atmosphere, the manufacturing time of the capacitor 1a tends to be shortened. This is because the time required for film formation by anodization or heat treatment in an oxidizing atmosphere is shorter than the time required for film formation by vapor deposition.

[0036] The conductor 30 is not limited to a specific conductor as long as it is conductive. The conductor 30 includes, for example, at least one selected from the group consisting of a conductive polymer, an electrolyte, and manganese oxide. In this case, the capacitor 1a is likely to have high reliability. Examples of conductive polymers include polyaniline and polypyrrole.

[0037] The conductor 30 preferably contains at least one selected from the group consisting of an electrolyte solution and a conductive polymer. In this case, the conductor 30 is likely to exhibit a self-repair function, and the capacitor 1a is likely to have high reliability.

[0038] FIG. 3 is a flowchart showing an example of a method for manufacturing a capacitor according to the present disclosure. Capacitor 1a includes, for example, a conductive and porous substrate 10, a first dielectric layer 21, and a second dielectric layer 22. The method for manufacturing capacitor 1a includes disposing a conductor 30 in a pore 15p of a porous body 15 having inwardly extending pores 15p. The conductor 30 is disposed in the pore 15p so as to contact the first dielectric layer 21 and the second dielectric layer 22. The first dielectric layer 21 is formed in a first region 15a on the substrate 10 by a vapor deposition method. The second dielectric layer 22 is formed in a second region 15b on the substrate 10 by anodization or thermal oxidation. The first region 15a is a region of the porous body 15 that includes a boundary 16 between the porous body 15 and the outside of the porous body 15. The second region 15b is a region of the porous body 15 that is located more inward than the first region 15a.

[0039] As shown in FIG. 3, in step S11, a first dielectric layer 21 is formed on a first portion 15a of the substrate 10 by a vapor deposition method. The vapor deposition method is not limited to a specific vapor deposition method. Examples of the vapor deposition method include chemical vapor deposition methods such as atomic layer deposition (ALD), chemical vapor deposition (CVD), and mist CVD. In this case, the desired portion of the substrate 10 is likely to be covered with the first dielectric layer 21. The vapor deposition method is preferably ALD. In this case, the desired portion of the substrate 10 is likely to be covered with the first dielectric layer 21, and the first dielectric layer 21 is likely to be formed uniformly. The vapor deposition method may be physical vapor deposition such as vacuum deposition.

[0040] Next, in step S12, the second dielectric layer 22 is formed by anodic oxidation or thermal oxidation on the second portion 15b of the substrate 10. In this manner, a capacitor member including the substrate 10, the first dielectric layer 21, and the second dielectric layer 22 is obtained.

[0041] Next, in step S13, conductors 30 are placed in the holes 15p of the porous body 15 of the capacitor member. For example, if the conductors 30 include a conductive polymer, the conductive polymer may be obtained by electrolytic polymerization in a state where a precursor of the conductor 30 is supplied to the holes 15p. In this manner, for example, a capacitor 1a is obtained.

[0042] Fig. 4 is a cross-sectional view showing another example of a capacitor according to the present disclosure. Capacitor 1b shown in Fig. 4 has the same configuration as capacitor 1a, except for portions that will be specifically described. Components of capacitor 1b that are the same as or correspond to those of capacitor 1a are given the same reference numerals, and detailed description thereof will be omitted. The description of capacitor 1a also applies to capacitor 1b, unless technically inconsistent.

[0043] As shown in FIG. 4 , the substrate 10 includes, for example, two porous portions 11 and a core portion 12. The core portion 12 is disposed between the two porous portions 11. Alternatively, the substrate 10 may have a cylindrical surface that defines the boundary 16, and the porous portion 11 may be formed so as to be positioned on the cylindrical surface, with the core portion 12 being surrounded by the porous portion 11. This configuration tends to increase the specific surface area of ​​the substrate 10 in contact with the dielectric layer, making it easier for the capacitor 1a to have a high capacitance. In the two porous portions 11, the dimension (depth) D1 of the first portion 15a in the direction perpendicular to the boundary 16 may be the same or different. In the two porous portions 11, the dimension (depth) D2 of the second portion 15b in the direction perpendicular to the boundary 16 may be the same or different.

[0044] Fig. 5 is a cross-sectional view showing yet another example of a capacitor according to the present disclosure. Capacitor 1c shown in Fig. 5 has the same configuration as capacitor 1a, except for portions that will be specifically described. Components of capacitor 1c that are the same as or correspond to components of capacitor 1a are given the same reference numerals, and detailed descriptions thereof will be omitted. The description of capacitor 1a also applies to capacitor 1c, unless technically inconsistent.

[0045] 5, holes 15p include through-holes in porous body 15. With this configuration, the specific surface area of ​​substrate 10 in contact with the dielectric layer tends to increase, and capacitor 1a tends to have a high capacitance.

[0046] Fig. 6 is a cross-sectional view showing yet another example of a capacitor according to the present disclosure. Capacitor 1d shown in Fig. 6 has the same configuration as capacitor 1a, except for portions that will be specifically described. Components of capacitor 1d that are the same as or correspond to those of capacitor 1a are given the same reference numerals, and detailed description thereof will be omitted. The description of capacitor 1a also applies to capacitor 1d, unless technically inconsistent.

[0047] As shown in FIG. 6, the capacitor 1d further includes a third dielectric layer 23. The third dielectric layer 23 is disposed on the substrate 10. The third dielectric layer 23 is disposed in the first portion 15a of the porous body 15. The third dielectric layer 23 is surrounded by, for example, the first dielectric layer 21. The third dielectric layer 23 includes, for example, an anodic oxide film. The third dielectric layer 23 may include an oxide film formed by heat treatment in an oxidizing atmosphere. The third dielectric layer 23 is a dielectric layer different from a layer consisting only of a natural oxide film.

[0048] As described above, when forming first dielectric layer 21 by vapor deposition, for example, it is possible that a portion of first portion 15a of substrate 10 may be exposed depending on the conditions of the vapor deposition process. However, according to the above-described capacitor manufacturing method, an oxide film such as an anodic oxide film may also be formed on the portion of substrate 10 exposed in first portion 15a during the formation of first dielectric layer 21. As a result, capacitor 1d is obtained that includes third dielectric layer 23. For the material and thickness of third dielectric layer 23, the description of the material and thickness of first dielectric layer 21 can be referenced.

[0049] Fig. 7 is a cross-sectional view of the portion surrounded by rectangle VII in Fig. 6. As shown in Fig. 7, the outer periphery of the third dielectric layer 23 may overlap the first dielectric layer 21. For example, the first dielectric layer 21 may be disposed on the outer periphery of the third dielectric layer 23.

[0050] FIG. 8A is a diagram schematically illustrating an example of an electric circuit according to the present disclosure. The electric circuit 3 includes a capacitor 1a. The electric circuit 3 may be an active circuit or a passive circuit. The electric circuit 3 may be a discharge circuit, a smoothing circuit, a decoupling circuit, or a coupling circuit. Because the electric circuit 3 includes the capacitor 1a, the electric circuit 3 is likely to exhibit the desired performance. For example, noise is likely to be reduced in the electric circuit 3. The electric circuit 3 may also include a capacitor 1b, 1c, or 1d.

[0051] 8B is a diagram schematically illustrating an example of a circuit board according to the present disclosure. As shown in FIG. 8B, the circuit board 5 includes a capacitor 1a. For example, an electric circuit 3 including the capacitor 1a is formed on the circuit board 5. Since the circuit board 5 includes the capacitor 1a, the circuit board 5 is likely to exhibit the desired performance. The circuit board 5 may be an embedded board or a motherboard. The circuit board 5 may include a capacitor 1b, 1c, or 1d.

[0052] FIG. 8C is a diagram schematically illustrating an example of a device according to the present disclosure. As shown in FIG. 8C, device 7 includes capacitor 1a. Device 7 includes, for example, circuit board 5 including capacitor 1a. Because device 7 includes capacitor 1a, device 7 is likely to exhibit desired performance. Device 7 may be an electronic device, a communication device, a signal processing device, or a power supply. Device 7 may be a server, an AC adapter, an accelerator, or a flat panel display such as a liquid crystal display (LCD). Device 7 may be a USB charger, a solid-state drive (SSD), an information terminal such as a PC, a smartphone, or a tablet PC, or an Ethernet switch. Device 7 may also include capacitor 1b, 1c, or 1d.

[0053] (Addendum) From the above description, the following techniques are disclosed.

[0054] (Technology 1) a porous body including a plurality of pores; a conductor; The porous body is a conductive substrate; a first dielectric layer disposed on the substrate; a second dielectric layer disposed on the substrate; the conductor is disposed on the first dielectric layer and the second dielectric layer; the first dielectric layer is disposed in a first region of the porous body that includes a boundary between the porous body and an outside of the porous body, the second dielectric layer is disposed in a second region of the porous body that is located more inward than the first region of the porous body; Capacitor.

[0055] (Technology 2) the first dielectric layer includes a vapor-deposited film; The capacitor according to technique 1.

[0056] (Technology 3) the second dielectric layer includes an anodic oxide film; The capacitor according to any one of the first and second aspects.

[0057] (Technology 4) The dielectric constant of the first dielectric layer is higher than the dielectric constant of the second dielectric layer. The capacitor according to any one of the first to third aspects.

[0058] (Technology 5) the substrate comprises a valve metal; The capacitor according to any one of the first to fourth aspects.

[0059] (Technology 6) The valve metal is aluminum. The capacitor according to technique 5.

[0060] (Technology 7) The substrate is a metal sintered body. The capacitor according to any one of the first to sixth aspects.

[0061] (Technology 8) The metal sintered body contains tantalum. The capacitor according to technique 7.

[0062] (Technology 9) the first dielectric layer comprises a metal compound; the metal compound includes at least one selected from the group consisting of a metal oxide, a metal nitride, and a metal oxynitride; The metal compound contains at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and zinc. The capacitor according to any one of the first to eighth aspects.

[0063] (Technology 10) the second dielectric layer comprises an oxide; The oxide contains at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and niobium. The capacitor according to any one of the first to ninth aspects.

[0064] (Technology 11) the conductor includes at least one selected from the group consisting of a conductive polymer, an electrolyte, and manganese oxide; The capacitor according to any one of the first to tenth aspects.

[0065] (Technology 12) An electric circuit comprising the capacitor according to any one of techniques 1 to 11.

[0066] (Technology 13) A circuit board comprising the capacitor according to any one of techniques 1 to 11.

[0067] (Technology 14) A device comprising the capacitor according to any one of techniques 1 to 11.

[0068] (Technology 15) A porous body including a plurality of pores is provided, The porous body is a conductive substrate; a first dielectric layer disposed on the substrate; a second dielectric layer disposed on the substrate; the first dielectric layer is disposed in a first region of the porous body that includes a boundary between the porous body and an outside of the porous body, the second dielectric layer is disposed in a second region of the porous body that is located more inward than the first region of the porous body; Capacitor components.

[0069] (Technology 16) Preparing a capacitor member according to technique 15; and disposing a conductor in the plurality of pores of the porous body so that the conductor contacts the first dielectric layer and the second dielectric layer. A method for manufacturing a capacitor.

[0070] (Technology 17) In preparing the capacitor member, the first dielectric layer is formed by a vapor phase method, The second dielectric layer is formed by anodic oxidation or thermal oxidation. The method for manufacturing a capacitor according to the technique 16. [Example]

[0071] The present disclosure will be described in more detail below with reference to examples. Note that the following examples are illustrative and the present disclosure is not limited to the following examples.

[0072] Example 1 An Al foil with a thickness of 120 μm was prepared. This Al foil was subjected to AC etching to make the surface porous, resulting in a substrate having a core and a porous portion. Porous portions with a thickness of 40 μm were formed on both sides of the Al foil by etching. The most frequent pore size of the pore distribution in the porous portion measured with a mercury intrusion porosimeter was 100 to 200 nm.

[0073] The ZrO2 layer was formed using an atomic layer deposition (ALD) system, FlexAL, manufactured by Oxford Instruments. The ALD film formation conditions were adjusted as follows. As a result, a ZrO2 layer was formed on the substrate, both on the surface and near the surface of the porous region.

[0074] Temperature: 250℃ Precursor: Tetrakisethylmethylaminozirconium (TEMAZ) Oxidizer: O2 plasma Pressure: 250mTorr Number of cycles: 140 cycles The substrate, on which a ZrO layer was formed on the surface and near the surface of the porous portion, was subjected to anodization, forming an AlO layer on the substrate in the deeper portion of the porous portion. The anodization was performed by immersing the substrate in a 0.3 mol / L aqueous solution of diammonium adipate and applying a voltage of 7 V for 60 minutes using the substrate as the anode. In this way, a sample according to Example 1 was obtained.

[0075] <Comparative Example 1> A sample according to Comparative Example 1 was obtained in the same manner as in Example 1, except that no anodic oxidation was carried out.

[0076] (Cross-sectional structure observation) Samples for cross-sectional observation were prepared from the samples of Example 1 and Comparative Example 1 by resin embedding. Electron micrographs of the samples were obtained using a JEOL JSM7900F scanning electron microscope (SEM) and a JEOL scanning transmission electron microscope (STEM). The electron micrograph of the sample prepared from the sample of Example 1 revealed that a ZrO2 layer was disposed on the Al substrate near the surface of the porous portion of the sample of Example 1, and the Al substrate was well coated. Meanwhile, an Al2O3 layer was disposed on the Al substrate deep within the porous portion of the sample of Example 1, and the Al2O3 layer was well coated. The thicknesses of the ZrO2 layer near the surface of the porous portion and the Al2O3 layer deep within the porous portion, as confirmed in the electron micrograph of the sample prepared from the sample of Example 1, are shown in Table 1.

[0077] Electron micrographs of specimens fabricated from the sample of Comparative Example 1 revealed that a ZrO2 layer was disposed on the Al substrate near the surface of the porous portion of the sample of Comparative Example 1, effectively covering the Al substrate. On the other hand, in the deeper portions of the porous portion of the sample of Comparative Example 1, the thickness of the Al2O3 layer on the Al substrate was 1 nm or less, and this Al2O3 is believed to be derived from a native oxide film. The thicknesses of the ZrO2 layer near the surface of the porous portion and the Al2O3 layer deep within the porous portion, as confirmed in the electron micrographs of the specimen fabricated from the sample of Comparative Example 1, are shown in Table 1. The native oxide film observed deep within the porous portion of the sample of Comparative Example 1 had poor insulating properties, almost identical to the exposed Al. Therefore, it is difficult to form a substantial dielectric layer on the substrate deep within the porous portion using only a vapor-phase process such as ALD. Therefore, the sample of Comparative Example 1 cannot be said to have an advantageous structure in terms of voltage resistance and high capacitance in a capacitor.

[0078] On the other hand, it is understood that the sample according to Example 1 has an advantageous structure in terms of voltage resistance and high capacitance when the pores in the porous portion are filled with a conductor to form a capacitor.

[0079] [Table 1] [Industrial Applicability]

[0080] The capacitor according to the present disclosure can be used, for example, in applications where voltage resistance and high capacitance are required. [Explanation of symbols]

[0081] 1a, 1b, 1c, 1d capacitors 3 Electrical Circuits 5 Circuit Board 7 Equipment 10 Base material 11 Porous part 12 Core 15 Porous materials 15a First part 15b Second part 15p hole 16 boundaries 21 First dielectric layer 22 second dielectric layer 23 Third dielectric layer 30 Conductors

Claims

1. a porous body including a plurality of pores; a conductor; The porous body is a conductive substrate; a first dielectric layer disposed on the substrate; a second dielectric layer disposed on the substrate; the conductor is disposed on the first dielectric layer and the second dielectric layer; the first dielectric layer is disposed in a first region of the porous body that includes a boundary between the porous body and the outside of the porous body; In the porous body, only the second dielectric layer is disposed in a second region located more inwardly than the first region of the porous body, In the first portion, at least a portion of the first dielectric layer is in contact with the substrate and the conductor. Capacitor.

2. the first dielectric layer includes a vapor-deposited film; The capacitor of claim 1 .

3. the second dielectric layer includes an anodic oxide film; The capacitor of claim 1 .

4. The dielectric constant of the first dielectric layer is higher than the dielectric constant of the second dielectric layer. The capacitor of claim 1 .

5. the substrate comprises a valve metal; The capacitor of claim 1 .

6. The valve metal is aluminum. The capacitor according to claim 5 .

7. The substrate is a metal sintered body. The capacitor of claim 1 .

8. The metal sintered body contains tantalum. The capacitor of claim 7.

9. the first dielectric layer comprises a metal compound; the metal compound includes at least one selected from the group consisting of a metal oxide, a metal nitride, and a metal oxynitride; The metal compound contains at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and zinc. The capacitor of claim 1 .

10. the second dielectric layer comprises an oxide; The oxide contains at least one selected from the group consisting of hafnium, zirconium, aluminum, tantalum, titanium, silicon, and niobium. The capacitor of claim 1 .

11. the conductor includes at least one selected from the group consisting of a conductive polymer, an electrolyte, and manganese oxide; The capacitor of claim 1 .

12. A capacitor according to any one of claims 1 to 11, Electrical circuit.

13. A capacitor according to any one of claims 1 to 11, Circuit board.

14. A capacitor according to any one of claims 1 to 11, device.

15. A porous body including a plurality of pores is provided, The porous body is a conductive substrate; a first dielectric layer disposed on the substrate; a second dielectric layer disposed on the substrate; the first dielectric layer is disposed in a first region of the porous body that includes a boundary between the porous body and the outside of the porous body; In the porous body, only the second dielectric layer is disposed in a second region located more inwardly than the first region of the porous body, In the first portion, at least a portion of the first dielectric layer is in contact with the substrate and a conductor different from the substrate that is included in the capacitor. Capacitor components.

16. Preparing a capacitor member according to claim 15; and disposing the conductor in the plurality of pores of the porous body so that the conductor is in contact with the first dielectric layer and the second dielectric layer. A method for manufacturing a capacitor.

17. In preparing the capacitor member, the first dielectric layer is formed by a vapor phase method, The second dielectric layer is formed by anodic oxidation or thermal oxidation. The method for manufacturing a capacitor according to claim 16.

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