Film formation method, film formation apparatus, and method for manufacturing electrode foil

Abstract

A method for producing a layer containing a metal oxide, comprising: a heating step of heating a portion of a metal foil containing a first metal by contacting the metal foil with one or more heating elements; a first contact step of contacting both surfaces of the metal foil with a first gas containing a second metal while the metal foil is partially supported; and a second contact step of contacting both surfaces of the metal foil with a second gas containing an oxidizing agent while the metal foil is partially supported.

Description

[Technical Field]

[0001] The present invention relates to a film-forming method, a film-forming apparatus, and a method for manufacturing electrode foil using atomic layer deposition, and more particularly to a method and apparatus for forming a layer containing a metal oxide (dielectric layer) on both sides of a metal foil. [Background technology]

[0002] A layer of metal oxide (dielectric) is formed on the surface of metal foil used as electrode foil in electrolytic capacitors. Patent Document 1 teaches that a dielectric layer is formed on the main surface of the metal foil by atomic layer deposition (ALD) method. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2017-154461 [Overview of the project] [Problems that the invention aims to solve]

[0004] The dielectric layer is typically formed on both main surfaces of the metal foil. From a productivity standpoint, it is desirable to efficiently form the dielectric layer on both main surfaces of the metal foil. [Means for solving the problem]

[0005] A first aspect of the present invention relates to a method for forming a layer containing a metal oxide, comprising: a heating step of heating a portion of a metal foil containing a first metal by bringing it into contact with one or more heating elements; a first contact step of bringing a first gas containing a second metal into contact with both sides of the metal foil while the portion of the metal foil is supported; and a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil while the portion of the metal foil is supported.

[0006] A second aspect of the present invention relates to a film-forming apparatus comprising: at least one chamber; a pressure control unit for controlling the pressure inside the chamber to a reduced pressure atmosphere; a first supply port for supplying a first gas containing a second metal to the chamber; a second supply port for supplying a second gas containing an oxidizing agent to the chamber; a first exhaust port for discharging the first gas from the chamber; a second exhaust port for discharging the second gas from the chamber; and one or more heating elements disposed inside the chamber and in contact with a portion of a metal foil that is to be film-formed, thereby heating the metal foil, wherein the first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

[0007] A third aspect of the present invention is a preparation step of preparing a metal foil containing a first metal; a roughening step of roughening both main surfaces of the metal foil; a heating step of heating the metal foil by bringing a portion of the roughened metal foil into contact with one or more heating elements; and a step of supporting the portion of the metal foil and the metal foil The aforementioned Both Lord of the Way A first contact step involves bringing a first gas containing a second metal into contact with the surface, and with a portion of the metal foil supported, the two surfaces of the metal foil Lord of the Way The present invention relates to a method for manufacturing an electrode foil, comprising a second contact step of contacting the surface with a second gas containing an oxidizing agent to form a dielectric layer.

[0008] A fourth aspect of the present invention relates to a method for forming a layer containing a metal oxide, comprising: a first contact step of bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal; a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil; and a first application step of bringing a portion of the metal foil into contact with one or more first power supply bodies and applying a voltage to the metal foil in the presence of the first gas.

[0009] A fifth aspect of the present invention is a preparation step of preparing a metal foil containing a first metal, a roughening step of roughening both main surfaces of the metal foil, and The aforementioned Metal foil The aforementioned Both Lord of the Way A first contact step in which a first gas containing a second metal is brought into contact with the surface, and the two surfaces of the metal foil Lord of the WayThe present invention relates to a method for manufacturing an electrode foil, comprising: a second contact step of bringing a second gas containing an oxidizing agent into contact with the surface of the metal foil; and a first application step of bringing a portion of the metal foil into contact with one or more first power supply bodies and applying a voltage to the metal foil in the presence of the first gas.

[0010] A sixth aspect of the present invention relates to a method for forming a layer containing a metal oxide, comprising: a first contact step of bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal; a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil; and an application step of bringing a portion of the metal foil into contact with one or more power supply bodies and applying a voltage to the metal foil in the presence of the second gas.

[0011] A seventh aspect of the present invention is a preparation step of preparing a metal foil containing a first metal, a roughening step of roughening both main surfaces of the metal foil, and The aforementioned Metal foil The aforementioned Both Lord of the Way A first contact step in which a first gas containing a second metal is brought into contact with the surface, and the two surfaces of the metal foil Lord of the Way The present invention relates to a method for manufacturing an electrode foil, comprising: a second contact step of bringing a second gas containing an oxidizing agent into contact with the surface of the metal foil; and a second application step of bringing a portion of the metal foil into contact with one or more second power supply bodies and applying a voltage to the metal foil in the presence of the second gas.

[0012] An eighth aspect of the present invention relates to a film-forming apparatus comprising at least one chamber, a pressure control unit for controlling the pressure inside the chamber to a reduced pressure atmosphere, a first supply port for supplying a first gas containing a second metal to the chamber, a second supply port for supplying a second gas containing an oxidizing agent to the chamber, a first exhaust port for discharging the first gas from the chamber, a second exhaust port for discharging the second gas from the chamber, one or more power supply units in contact with a portion of a metal foil that is to be film-formed, and a counter electrode for generating a voltage difference between the metal foil and the power supply units, wherein the first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

[0013] A ninth aspect of the present invention relates to a method for forming a layer containing a metal oxide, comprising: a heating step of heating a metal foil containing a first metal by bringing a part of the metal foil into contact with one or more heating elements; a first contact step of bringing a first gas containing a second metal into contact with both surfaces of the metal foil while a part of the metal foil is supported; a second contact step of bringing a second gas containing an oxidizing agent into contact with both surfaces of the metal foil while a part of the metal foil is supported; and an application step of bringing a part of the metal foil into contact with one or more power supply bodies and applying a voltage to the metal foil in the presence of at least one of the first gas and the second gas.

Effects of the Invention

[0014] According to the present invention, a dielectric layer can be efficiently formed on both main surfaces of a metal foil by using an atomic layer deposition method.

Brief Description of the Drawings

[0015] [Figure 1] It is a flowchart showing a film forming method according to a first aspect of the present invention. [Figure 2] It is a flowchart showing a method for manufacturing an electrode foil according to a first aspect of the present invention. [Figure 3] It is a SEM image (300 times) of a cross section of a roughened metal foil according to an embodiment of the present invention. [Figure 4] It is a side view conceptually showing an example of a film forming apparatus according to a first aspect of the present invention. [Figure 5] It is a side view conceptually showing another example of a film forming apparatus according to a first aspect of the present invention. [Figure 6] It is a side view conceptually showing another example of a film forming apparatus according to a first aspect of the present invention. [Figure 7] It is a side view conceptually showing a main part of another film forming apparatus according to a first aspect of the present invention. [Figure 8] It is a side view conceptually showing another example of a film forming apparatus according to a first aspect of the present invention. [Figure 9] It is a side view conceptually showing another example of a film forming apparatus according to a first aspect of the present invention. [Figure 10]This flowchart shows a film-forming method according to a second aspect of the present invention. [Figure 11] This is a flowchart showing a method for manufacturing an electrode foil according to a second aspect of the present invention. [Figure 12] This is a flowchart showing a film-forming method according to a third aspect of the present invention. [Figure 13] This is a flowchart showing a method for manufacturing an electrode foil according to a third aspect of the present invention. [Figure 14] This flowchart shows the film-forming method according to the second and third aspects of the present invention. [Figure 15] This is a flowchart showing a method for manufacturing electrode foil according to the second and third aspects of the present invention. [Figure 16] This is a conceptual side view showing an example of a film-forming apparatus according to the second and third aspects of the present invention. [Figure 17] This is a conceptual side view illustrating an example of another film-forming apparatus according to the second and third aspects of the present invention. [Figure 18] This is a conceptual side view illustrating an example of yet another film-forming apparatus according to the second and third aspects of the present invention. [Figure 19] This is a conceptual side view illustrating an example of yet another film-forming apparatus according to the second and third aspects of the present invention. [Figure 20] This is a conceptual side view illustrating an example of yet another film-forming apparatus according to the second and third aspects of the present invention. [Figure 21] This is a conceptual side view illustrating an example of yet another film-forming apparatus according to the second and third aspects of the present invention. [Figure 22] This flowchart shows a film-forming method according to a fourth aspect of the present invention. [Figure 23] This is a flowchart showing a method for manufacturing an electrode foil according to a fourth aspect of the present invention. [Figure 24] This is a conceptual side view showing an example of a film-forming apparatus according to the fourth aspect of the present invention. [Modes for carrying out the invention]

[0016] In this embodiment, the object on which the dielectric layer is formed is a metal foil. Compared to resin films and the like, metal foil has higher heat resistance, thermal conductivity, and electrical conductivity, and also possesses a certain degree of rigidity. This embodiment utilizes these properties of metal foil to simultaneously form layers containing metal oxides (dielectric layers) on both main surfaces of the metal foil.

[0017] A film-forming method according to the first embodiment comprises a heating step of heating a metal foil containing a first metal by bringing a portion of the metal foil into contact with one or more heating elements; a first contact step of bringing a first gas containing a second metal into contact with both sides of the metal foil while a portion of the metal foil is supported; and a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil while a portion of the metal foil is supported.

[0018] The film-forming method according to the first embodiment is carried out using the following film-forming apparatus. This embodiment includes this film-forming apparatus. In other words, the film-forming apparatus according to the first embodiment comprises at least one chamber, a pressure control unit for controlling the pressure inside the chamber to a reduced pressure atmosphere, a first supply port for supplying a first gas containing a second metal to the chamber, a second supply port for supplying a second gas containing an oxidizing agent to the chamber, a first exhaust port for discharging the first gas from the chamber, a second exhaust port for discharging the second gas from the chamber, and one or more heating elements disposed inside the chamber and in contact with a portion of the metal foil to be formed to heat the metal foil. The first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

[0019] An electrode foil for an electrolytic capacitor can be manufactured using the film-forming apparatus and / or film-forming method according to the first embodiment. This embodiment includes a method for manufacturing this electrode foil. In other words, the method for manufacturing an electrode foil according to the first embodiment includes a preparation step of preparing a metal foil containing a first metal, a roughening step of roughening both main surfaces of the metal foil, a heating step of heating the metal foil by bringing a part of the roughened metal foil into contact with one or more heating elements, and with a part of the metal foil supported, both sides of the metal foil Lord of the Way A first contact step involves bringing a first gas containing a second metal into contact with the surface, and with a portion of the metal foil supported, both sides of the metal foil... Lord of the Way The method comprises a second contact step of bringing a second gas containing an oxidizing agent into contact with the surface to form a dielectric layer.

[0020] A film-forming method according to the second embodiment comprises: a first contact step of bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal; a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil; and a first application step of bringing a portion of the metal foil into contact with one or more first power supply units and applying a voltage to the metal foil in the presence of the first gas.

[0021] An electrode foil for an electrolytic capacitor can be manufactured using the film-forming method according to the second embodiment. This embodiment includes this method for manufacturing electrode foil. In other words, the method for manufacturing an electrode foil according to the second embodiment includes a preparation step of preparing a metal foil containing a first metal, a roughening step of roughening both main surfaces of the metal foil, and both of the roughened metal foil Lord of the Way A first contact step involves bringing a first gas containing a second metal into contact with the surface, and both metal foils Lord of the Way The device comprises a second contact step of bringing a second gas containing an oxidizing agent into contact with the surface, and a first application step of bringing a portion of the metal foil into contact with one or more first power supply units and applying a voltage to the metal foil in the presence of the first gas.

[0022] A film-forming method according to the third embodiment comprises a first contact step of bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal, a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil, and an application step of bringing a portion of the metal foil into contact with one or more power supply units and applying a voltage to the metal foil in the presence of the second gas.

[0023] An electrode foil for an electrolytic capacitor can be manufactured using the film-forming method according to the third embodiment. This embodiment includes this method for manufacturing electrode foil. In other words, the method for manufacturing an electrode foil according to the third embodiment includes a preparation step of preparing a metal foil containing a first metal, a roughening step of roughening both main surfaces of the metal foil, and both of the roughened metal foil Lord of the Way A first contact step involves bringing a first gas containing a second metal into contact with the surface, and both metal foils Lord of the WayThe device comprises a second contact step of bringing a second gas containing an oxidizing agent into contact with the surface, and a second application step of bringing a portion of the metal foil into contact with one or more second power supply units and applying a voltage to the metal foil in the presence of the second gas.

[0024] The film-forming methods according to the second and third embodiments are carried out using the following film-forming apparatus. This embodiment includes this film-forming apparatus. In other words, the film-forming apparatus according to the second and third embodiments comprises at least one chamber, a pressure control unit for controlling the pressure inside the chamber to a reduced pressure atmosphere, a first supply port for supplying a first gas containing a second metal to the chamber, a second supply port for supplying a second gas containing an oxidizing agent to the chamber, a first exhaust port for discharging the first gas from the chamber, a second exhaust port for discharging the second gas from the chamber, one or more power supply units in contact with a portion of the metal foil that is to be film-formed, and a counter electrode for generating a voltage difference between the metal foil and the power supply units. The first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

[0025] A film-forming method according to the fourth embodiment comprises a heating step of heating a metal foil by bringing a portion of the metal foil containing a first metal into contact with one or more heating elements; a first contact step of bringing a first gas containing a second metal into contact with both sides of the metal foil while the portion of the metal foil is supported; a second contact step of bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil while the portion of the metal foil is supported; and an application step of bringing a portion of the metal foil into contact with one or more power supply elements and applying a voltage to the metal foil in the presence of at least one of the first gas and the second gas.

[0026] I. First aspect In this embodiment, the metal foil is heated. The heat promotes the reaction between the molecules containing the second metal and / or the oxidizing agent and the surface of the metal foil. Thus, a uniform dielectric layer is formed.

[0027] [Film forming method] The film-forming method according to the first embodiment includes a heating step of heating a metal foil. Figure 1 is a flowchart showing the film-forming method according to the first embodiment.

[0028] (Metal foil) The metal foil contains a first metal. The type of the first metal is not particularly limited. The first metal may be a valve metal such as aluminum (Al), tantalum (Ta), or niobium (Nb), or an alloy containing a valve metal, as these facilitate the formation of a dielectric layer. The thickness of the metal foil is not particularly limited, but may be, for example, 10 μm to 300 μm, or 15 μm to 250 μm. The purity of the metal foil is not particularly limited. The purity of the metal foil may be, for example, 99% to 99.99%.

[0029] The surface of the metal foil may be roughened. Furthermore, other dielectric layers may be formed on the surface of the metal foil. For example, the metal foil may have other dielectric layers formed inside pits created by roughening. Other dielectric films may be formed, for example, by anodizing.

[0030] (i) Surface modification process (S111) Before the first contact step, and preferably before the heating step, a surface modification treatment may be performed to modify the surface of the metal foil. The surface modification treatment removes impurities from the surface of the metal foil and modifies the surface condition of the metal foil. This improves the uniformity, adhesion, density, diffusion prevention effect of metal atoms in the metal foil, and insulation properties of the formed film, and further improves characteristics such as leakage current and capacitance. In particular, the effects of the surface modification step are easily obtained when the withstand voltage of the resulting electrode foil is 200V or less, and even 50V or less.

[0031] The surface modification treatment is not particularly limited and includes, for example, plasma treatment and atmospheric pressure plasma treatment. The surface modification treatment may be carried out in air or under reduced pressure. Through surface modification, for example, hydroxyl groups are added to the surface of the metal foil, or impurities such as organic matter are decomposed or vaporized.

[0032] (ii) Heating process (S112) In the heating process, the metal foil is brought into contact with a heating element. Since metal foils generally have high heat resistance, a heating method by contact can be applied. Atomic layer deposition (ALD) is performed in a reduced-pressure atmosphere, so heat transfer by convection cannot be expected to be significant. Therefore, the method of this embodiment, which can heat using thermal conduction, is suitable for the ALD method. A portion of the metal foil comes into contact with the heating element. Because metal foils have high thermal conductivity, the entire metal foil can be heated rapidly by bringing a portion of it into contact with the heating element.

[0033] During heating, the metal foil may be pressed toward the heating element by a pressing member positioned to correspond to the heating element. This brings the metal foil and heating element into closer contact, allowing the metal foil to heat more efficiently. The pressing member, like the heating element, is in contact with a portion of the metal foil. The pressing member may also be a heating element. By bringing the heating element into contact with both main surfaces of the metal foil, the heating efficiency is further improved.

[0034] The heating temperature is not particularly limited and can be set appropriately according to the conditions of the method for forming the dielectric layer (atomic layer deposition). For example, the heating temperature is between 80°C and 550°C.

[0035] When the metal foil contains aluminum, the heating temperature is preferably between 90°C and 525°C. Within this temperature range, the effects of heating are easily obtained, and deformation of the metal foil is easily suppressed. In particular, when conveying metal foil roll-to-roll, the metal foil is subjected to stress from rollers, etc., making it prone to pit deformation and plastic deformation. When the metal foil deforms, conveyance becomes unstable, and the film formation tends to become uneven.

[0036] When the metal foil contains aluminum, the heating temperature is preferably between 90°C and 480°C. Within this heating temperature range, deformation of the pit shape and plastic deformation can be minimized.

[0037] (iii) First contact step (S113) A heated metal foil is brought into contact with a first gas containing a second metal, while a portion of the foil is supported. This allows the first gas to come into contact with both main surfaces (both sides) of the metal foil. Molecules containing the second metal, which were present in the first gas, adhere to both sides of the metal foil.

[0038] Examples of the second metal include Al, Ta, Nb, silicon (Si), titanium (Ti), zirconium (Zr), and hafnium (Hf). These may be used individually or in combination of two or more. That is, the dielectric layer may contain Al2O3, Ta2O5, Nb2O5, SiO2, TiO2, ZrO2, and HfO2 individually or in combination of two or more. When the dielectric layer contains oxides of two or more second metals, the oxides may be mixed together or arranged in layers. In particular, it is preferable that the second metal is a different metal species from the first metal contained in the metal foil. Especially in terms of increasing the capacitance of the resulting electrolytic capacitor, it is preferable that the oxide of the second metal has a higher relative permittivity than the oxide of the first metal. Also, in terms of improving the dielectric strength of the electrolytic capacitor, it is preferable that the oxide of the second metal is Ta2O 5、 SiO 2、 ZrO2 and HfO2 are preferred.

[0039] The first gas contains a precursor containing the second metal in gaseous form. The first gas may contain multiple types of precursors. Different types of precursors may be supplied to the chamber simultaneously or sequentially. Alternatively, the type of precursor contained in the first gas may be changed with each cycle.

[0040] The precursor is an organometallic compound containing a metallodites, which makes the metallodites more readily adsorbed onto the target material. Various organometallic compounds conventionally used in ALD (Advanced Liquid Processing) can be used as precursors.

[0041] Examples of Ti-containing precursors include bis(t-butylcyclopentadienyl)titanium(IV) dichloride (C 18 H 26 Cl2 Examples of titanium-containing precursors include titanium(IV) tetrakis(dimethylamino) ([(CH3)2N]4Ti, TDMAT), titanium(IV) tetrakis(diethylamino) ([(C2H5)2N]4Ti), titanium(IV) tetrakis(ethylmethylamino) (Ti[N(C2H5)(CH3)]4), titanium(IV) diisopropoxide-bis(2,2,6,6-tetramethyl-3,5-heptanedionate) (Ti[OCC(CH3)3CHCOC(CH3)3]2(OC3H7)2), titanium tetrachloride (TiCl4), titanium(IV) isopropoxide (Ti[OCH(CH3)2]4), titanium(IV) ethoxide (Ti[O(C2H5)]4), etc.

[0042] Examples of Al-containing precursors include trimethylaluminum ((CH3)3Al), etc. Examples of Zr-containing precursors include bis(methyl-η5-cyclopentadienyl)methoxymethyld zirconium (Zr(CH3C5H4)2CH3OCH3), zirconium(IV) tetrakis(dimethylamide) ([(CH3)2N]4Zr), zirconium(IV) tetrakis(ethylmethylamide) (Zr(NCH3C2H5)4) 、 zirconium(IV) t-butoxide (Zr[OC(CH3)3]4), etc. Examples of Nb-containing precursors include niobium(V) ethoxide (Nb(OCH2CH3)5, tris(diethylamide)(t-butylimide)niobium(V) (C 16 H 39 N four Nb), etc.

[0043] Examples of Si-containing precursors include N-sec-butyl(trimethylsilyl)amine (C7H 19 NSi), 1,3-diethyl-1,1,3,3-tetramethyldisilazane (C8H 23Examples include NSi2), 2,4,6,8,10-pentamethylcyclopentasiloxane ((CH3SiHO)5), pentamethyldisilane ((CH3)3SiSi(CH3)2H), tris(isopropoxy)silanol ([(H3C)2CHO]3SiOH), chloropentanemethyldisilane ((CH3)3SiSi(CH3)2Cl), dichlorosilane (SiH2Cl2), tridimethylaminosilane (Si[N(CH3)2]4), tetraethylsilane (Si(C2H5)4), tetramethylsilane (Si(CH3)4), tetraethoxysilane (Si(OC2H5)4), dodecamethylcyclohexasilane ((Si(CH3)2)6), silicon tetrachloride (SiCl4), silicon tetrabromide (SiBr4), etc.

[0044] Examples of precursors containing Ta include tris(ethylmethylamide)(t-butylamide)tantalum(V)(C) 13 H 33 Examples include N4Ta), tantalum(V) pentaethoxide (Ta(OC2H5)5), tris(diethylamide)(t-butylimide)tantalum(V)((CH3)3CNTa(N(C2H5)2)3), and pentakis(dimethylamino)tantalum(V)(Ta(N(CH3)2)5).

[0045] Examples of Hf-containing precursors include hafnium tetrachloride (HfCl4), tetrakisdimethylaminohafnium (Hf[N(CH3)2]4), tetrakisethylmethylaminohafnium (Hf[N(C2H5)(CH3)]4), tetrakisdiethylaminohafnium (Hf[N(C2H5)2]4), and hafnium-t-butoxide (Hf[OC(CH3)3]4).

[0046] (iv) Second contact step (S114) After purging the first gas, the second gas is brought into contact with the metal foil. Even at this stage, a portion of the metal foil is supported. Therefore, the second gas can come into contact with both sides of the metal foil. Molecules containing the second metal, adhering to both sides of the metal foil, react with the oxidizing agent in the second gas, generating an oxide of the second metal. As a result, a dielectric layer containing the oxide of the second metal is formed on both sides of the metal foil without the need to reverse its orientation.

[0047] The second gas contains an inert gas and an oxidizing agent. As the inert gas, the inert gas conventionally used in the ALD method can be used. Examples of inert gases include nitrogen and argon.

[0048] As the oxidizing agent, conventional oxidizing agents used in the ALD method can be used. Examples of oxidizing agents include water, oxygen, ozone, hydrogen peroxide, and carbon dioxide. The oxidizing agent may also be supplied to the reaction chamber as a plasma using the oxidizing agent as a raw material.

[0049] The order of each step is not particularly limited. Typically, the first gas is brought into contact with the metal foil, and then the second gas is brought into contact with the metal foil. The first contact step may be performed while heating the metal foil. The second contact step may also be performed while heating the metal foil.

[0050] The first and second contact processes may be repeated multiple times. Specifically, the process of supplying (pulsing) the first gas, purging the first gas, supplying (pulsing) the second gas, and purging the second gas may be repeated within the chamber. The type of first gas and / or second gas may be changed with each cycle. After dielectric layers are formed using the first and second gases, further dielectric layers may be formed using other first and second gases.

[0051] In the ALD method, a self-limiting mechanism is in operation, causing the second metal to deposit on the surface of the object in atomic layers. Therefore, the thickness of the dielectric layer is controlled by the number of cycles, with the first and second contact processes counting as one cycle. The thickness of the dielectric layer is not particularly limited and may be, for example, between 0.5 nm and 200 nm.

[0052] Preferably, the heating step and the first contact step and / or second contact step are performed within the same chamber space. The same chamber does not include, for example, cases where more than 80% of the wall connecting two chambers is physically blocked. This allows the metal foil to come into contact with the first gas quickly after heating, making it easier for molecules containing the second metal and / or oxidizing agents contained in the first gas to adhere to the metal foil, thereby enabling more efficient film formation.

[0053] [Method for manufacturing electrode foil] The method for manufacturing an electrode foil according to the first embodiment includes a heating step of heating a metal foil by bringing a portion of the metal foil into contact with one or more heating elements.

[0054] In the first embodiment of the film-forming method and electrode foil manufacturing method, either a metal foil of a predetermined size or a long metal foil is the object to be film-formed. The electrode foil manufactured by the above method is suitably used as the anode of an electrolytic capacitor.

[0055] The manufacturing method of the electrode foil according to the first embodiment will be described in detail step by step below. Figure 2 is a flowchart of the manufacturing method of the electrode foil according to the first embodiment.

[0056] (1) Preparation process (S11) A metal foil similar to that described in the film-forming method according to the first embodiment is prepared. The metal foil may have other dielectric layers formed inside the pits formed by roughening.

[0057] (2) Surface roughening process (S12) Before heating the metal foil, the surface of the metal foil may be roughened. Roughening creates multiple pits on the surface of the metal foil. In a subsequent process, it is expected that the capacitance will increase as a dielectric layer is formed inside these pits. On the other hand, when the surface of the metal foil is roughened in this way, it is usually difficult to form a dielectric layer inside the pits by methods other than anodizing. By performing a heat treatment as in this embodiment, it becomes easy to form a uniform dielectric layer inside the pits. When forming a dielectric layer containing an oxide of a second metal and then anodizing it to form a third dielectric layer, which will be described later, it is preferable to perform this step. If the third dielectric layer to be formed has a porous structure, this step may be omitted.

[0058] Surface roughening is performed, for example, by etching the metal foil. Etching is preferably carried out by electrolytic etching. Electrolytic etching is performed by passing a direct current or alternating current through the metal foil. Electrolytic etching is performed, for example, in an aqueous hydrochloric acid solution.

[0059] The pore size of the pits formed on the surface of the metal foil is not particularly limited. The pore size is preferably between 50 nm and 2000 nm, as this tends to increase the surface area. From the viewpoint of contact between the metal foil and the heating element or conveyor roll, it is preferable that the pore size is not excessively large. More preferably, the pore size is between 80 nm and 1300 nm. The pore size of the pits is, for example, the most frequent pore size in the pore distribution measured by a mercury porosimeter (the same applies hereinafter).

[0060] The thickness of the etching layer formed by multiple pits is not particularly limited and can be set appropriately according to the thickness of the metal foil. When the metal foil is used as the anode of an electrolytic capacitor, from the viewpoint of capacitance, the thickness of the etching layer is preferably 5 μm or more, and more preferably 15 μm or more. When the thickness of the etching layer is within this range, the effect of heating is easily obtained. From the viewpoint of the strength of the metal foil, the thickness of the etching layer is preferably 100 μm or less, and more preferably 80 μm or less. The thickness of the etching layer is the thickness of the etching layer formed on one main surface of the metal foil. The thickness of the etching layer is the average value of any 10 points in the SEM or TEM image of the cross-section of the metal foil. The thickness of the dielectric layer is calculated in the same manner (the same applies hereinafter).

[0061] Figure 3 is an SEM image (300x magnification) of a cross-section of the roughened metal foil according to this embodiment. In Figure 3, the area shown in light gray in the center is the core, which has lower porosity. The core is the unetched area of ​​the metal foil. The area adjacent to the core, shown in dark gray, is the etching layer. The etching layer is formed on both main surfaces of the metal foil. The area shown in black outside the etching layer is the background.

[0062] (3) Surface modification process (S13) Before the first contact step, preferably before the heating step, a surface modification treatment may be performed to modify the surface of the metal foil. The surface modification step is carried out in the same manner as (i) the surface modification step in the film-forming method according to the first embodiment.

[0063] (4)Heating process (S14) The metal foil is heated in the same manner as in step (ii) of the film-forming method according to the first embodiment. The metal foil is heated by bringing a heating element into contact with a portion of the metal foil. It is preferable that the heating of the metal foil be carried out in a chamber supplied with a first gas. The chamber may be under reduced pressure during heating.

[0064] (5) First contact step (S15) and second contact step (S16) Using the above-described film-forming apparatus, the first gas and the second gas are brought into contact with both sides of the metal foil, respectively. Each contact step is carried out in the same manner as (iii) the first contact step and (iv) the second contact step in the film-forming method according to the first embodiment. As a result, dielectric layers containing the oxide of the second metal are formed on both sides of the metal foil.

[0065] After forming the dielectric layer, the metal foil may be chemically treated. This forms a third dielectric layer between the metal foil and the dielectric layer, containing an oxide of the first metal constituting the metal foil. As a result, the dielectric layer as a whole is more easily formed with a uniform thickness and no pinholes. The method for chemically treating the metal foil is not particularly limited. Chemical treatment can be performed, for example, by immersing the metal foil in a chemical treatment solution and applying a voltage (anodic oxidation).

[0066] [Film forming equipment] The film-forming apparatus according to the first embodiment includes a heating element placed inside a chamber that contacts a portion of the metal foil to be formed and heats the metal foil. The first gas and the second gas are supplied so as to contact both main surfaces of the metal foil.

[0067] (heating element) The heating element heats the metal foil by contacting a portion of the metal foil that is to be film-formed. There may be one or more heating elements, or two or more. The shape of the heating element is not particularly limited as long as it can contact the metal foil over a certain area. The heating element may be, for example, a stage that supports the metal foil, a conveying roll, or a positioning member that positions the metal foil.

[0068] (Chamber) The film deposition apparatus comprises at least one chamber. The film-forming apparatus may include one chamber capable of supplying and exhausting a first gas and a second gas.

[0069] The film-forming apparatus may include multiple chambers capable of supplying and exhausting a first gas and a second gas. In this case, the same type of first gas may be supplied to each of the multiple chambers, and multiple types of first gases containing different second metals may be supplied to each chamber. The same type of second gas may be supplied to each of the multiple chambers, and multiple types of second gases containing different oxidizing agents may be supplied to each chamber. However, the heating element only needs to be placed in at least one of the multiple chambers.

[0070] The film-forming apparatus may include a first chamber capable of supplying and exhausting a first gas, and a second chamber capable of supplying and exhausting a second gas. However, the heating element only needs to be located in at least one of these chambers. Preferably, the heating element is located in the first chamber.

[0071] The film-forming apparatus may comprise a plurality of first chambers and / or second chambers. In this case, the same type of first gas may be supplied to the plurality of first chambers, and a plurality of first gases containing different second metals may be supplied to each chamber. The same type of second gas may be supplied to the plurality of second chambers, and a plurality of second gases containing different oxidizing agents may be supplied to each chamber. However, the heating element only needs to be located in at least one of the plurality of chambers. Preferably, the heating element is located in at least one first chamber.

[0072] From a productivity standpoint, the film deposition apparatus is preferably equipped with at least one chamber capable of supplying and exhausting a first gas and a second gas. This allows the formation of at least one dielectric layer to be completed within a single chamber.

[0073] (Pressure control unit) The chamber includes a pressure control unit. The pressure inside the chamber is controlled by the pressure control unit to create a reduced-pressure atmosphere. The pressure control unit includes, for example, a computer.

[0074] (Supply port and exhaust port) The chamber includes a first supply port for supplying a first gas into the chamber and a first exhaust port for discharging the first gas. The chamber also includes a second supply port for supplying a second gas into the chamber and a second exhaust port for discharging the second gas. The first and second gases may be supplied from the same supply port. The first and second gases may be exhausted from the same exhaust port.

[0075] (Support) In addition to the heating element, the chamber may include a support that contacts a portion of the metal foil and supports it. There may be one or more supports, or two or more. The shape of the support is not particularly limited as long as it can stably support the metal foil. The support may be, for example, a stage that supports the metal foil, a conveying roll, or a positioning member that positions the metal foil.

[0076] (Pressing member) The chamber may further include a pressing member positioned to correspond to the heating element and for pressing the metal foil toward the heating element. This ensures close contact between the metal foil and the heating element, allowing the metal foil to be heated efficiently. The pressing member, like the heating element, is in contact with a portion of the metal foil. The pressing member may also be a heating element. By bringing the heating element into contact with both main surfaces of the metal foil, the heating efficiency is further improved.

[0077] The film-forming method and film-forming apparatus according to the first embodiment can use a metal foil of a predetermined size as the object to be formed, or a long metal foil as the object to be formed. The long metal foil is, for example, transported in a chamber, and a dielectric layer is continuously formed on the transported metal foil.

[0078] The film-forming apparatus according to the first embodiment will be described below, divided into two cases: when the object to be formed is metal foil that has been cut to a predetermined size in advance (hereinafter referred to as the batch method), and when the object to be formed is a long piece of metal foil (hereinafter referred to as the roll-to-roll method).

[0079] A. Batch method In this embodiment, the heating element is, for example, a stage. The metal foil is heated by being placed on the stage in the chamber. The stage is in contact with a portion of the metal foil.

[0080] [Embodiment II] Figure 4 is a conceptual side view showing an example of a film-forming apparatus according to the first embodiment, which is used in a batch system.

[0081] The film-forming apparatus 10A includes a chamber 11 capable of supplying and exhausting a first gas and a second gas. The chamber 11 includes a first supply port 121 for supplying the first gas G1 into the chamber 11 and a second supply port 122 for supplying the second gas G2 into the chamber 11. The chamber 11 further includes an exhaust port 13 for discharging the first gas G1 and the second gas G2. The first gas G1 and the second gas G2 may be exhausted from different exhaust ports.

[0082] The pressure inside the chamber 11 is controlled by the pressure control unit 16. When the first gas G1 and the second gas G2 are supplied into the chamber 11, the pressure control unit 16 controls the chamber 11 to create a reduced pressure atmosphere.

[0083] A stage 14 is positioned inside the chamber 11. The stage 14 has a flat surface that contacts the metal foil 100. The metal foil 100 is placed on the stage 14 such that a portion of it is in contact with it. Because the metal foil 100 has moderate rigidity, it is supported by the stage 14 without excessive sagging or loosening. The stage 14 is a heating element 19. Because the metal foil 100 has good thermal conductivity, the entire foil can be rapidly heated by the stage 14, which is in contact with a portion of it.

[0084] Since the metal foil 100 is supported in a substantially planar manner by the stage 14, the first gas G1 and the second gas G2 supplied into the chamber 11 can come into contact with both main surfaces of the metal foil 100. As a result, at least one dielectric layer is formed on both main surfaces of the metal foil 100 in a single process.

[0085] A pressing member 15 is positioned at the location corresponding to stage 14 to press the metal foil 100 toward stage 14. The pressing member 15 has a flat portion that contacts the metal foil 100. The pressing member 15 may be a heating element 19.

[0086] [Embodiment I-II] Figure 5 is a conceptual side view showing another example of a film-forming apparatus according to the first embodiment. Film-forming apparatus 10B has the same configuration as film-forming apparatus 10A, except that it has multiple stages 14. At least one of the stages 14 is a heating element 19.

[0087] B. Roll-to-roll system In this embodiment, the heating element comes into contact with a portion of the metal foil being transported in the first chamber. The metal foil is heated as it is being transported. The heating element may be a transport roll, a positioning member for positioning the transported metal foil, or a stage for supporting the transported metal foil.

[0088] When supplying and exhausting a first gas and a second gas within a single chamber, the chamber may be divided into multiple sections. For example, the chamber may comprise a first supply zone for supplying the first gas, a second supply zone for supplying the second gas, a first exhaust zone for purging the first gas, and a second exhaust zone for purging the second gas. Each zone may be separated by a wall of, for example, an inert gas (nitrogen, argon, etc.). However, the above multiple zones can be considered as a single space. Furthermore, the parts of the chamber other than the above zones also form a single space together with the above multiple zones. The metal foil may pass through each zone multiple times.

[0089] [Embodiments I-III] Figure 6 is a conceptual side view of an example of a film-forming apparatus according to the first embodiment, which is used in a roll-to-roll manner.

[0090] The film-forming apparatus 20A includes a chamber 21 capable of supplying and exhausting a first gas and a second gas. The chamber 21 comprises a first supply zone SZ1 to which the first gas G1 is supplied, a second supply zone SZ2 to which the second gas G2 is supplied, a first exhaust zone EZ1 for purging the first gas G1, and a second exhaust zone EZ2 for purging the second gas G2. The zones are arranged in this order so as to separate the chamber 21 in a direction intersecting the conveying direction.

[0091] Chamber 21 includes a first supply port 221 for supplying the first gas G1 to the first supply zone SZ1, and a second supply port 222 for supplying the second gas G2 to the second supply zone SZ2. Chamber 21 also includes a first exhaust port 231 for discharging the first gas G1 from the first exhaust zone EZ1, and a second exhaust port 232 for discharging the second gas G2 from the second exhaust zone EZ2.

[0092] Upstream of the chamber 21 is a stage 241 that supports the metal foil 200 being transported. The stage 241 is a heating element 29. The stage 241 has a flat surface that contacts the metal foil 200. The heating element 29 is located upstream of the first supply zone SZ1. The heating element 29 may also be located within the first supply zone SZ1, which is the furthest upstream. The heating element 29 may also be located in at least one of the first exhaust zone EZ1, the second supply zone SZ2, and the second exhaust zone EZ2.

[0093] In the first exhaust zone EZ1, an inert gas G3 (for example, nitrogen gas) is supplied from the third supply port 223. This separates the first supply zone SZ1 from the second supply zone SZ2, and the unreacted first gas G1 is purged from the first exhaust port 231.

[0094] Similarly, inert gas G3 is supplied to the second exhaust zone EZ2 from the third supply port 223. This separates the second supply zone SZ2 from the rest of the chamber 21, and purges unreacted second gas G2 from the second exhaust port 232. The third gas G3 supplied to the first exhaust zone EZ1 and the second exhaust zone EZ2 may be the same or different. Purge from each exhaust port is performed as appropriate. The exhaust ports to be used should be determined as needed. Additional exhaust ports may be added as needed.

[0095] The film deposition apparatus 20A may include multiple combinations of a first supply zone SZ1, a first exhaust zone EZ1, a second supply zone SZ2, and a second exhaust zone EZ2, depending on the desired dielectric layer thickness. The first gas G1 supplied in the multiple first supply zones SZ1 may be of the same type or different types. The second gas G2 supplied in the multiple second supply zones SZ2 may be of the same type or different types.

[0096] The metal foil 200 may pass through the combination of the first supply zone SZ1, the first exhaust zone EZ1, the second supply zone SZ2, and the second exhaust zone EZ2 multiple times, depending on the desired thickness of the dielectric layer.

[0097] The pressure inside the chamber 21 is controlled by the pressure control unit 26 to create a reduced pressure atmosphere. The pressure control unit 26 may also control the pressure in each zone as appropriate.

[0098] The metal foil 200 is wound onto a supply reel 201 that is rotationally driven by a motor, and is supplied upstream within the chamber 21 as it is unwound from the supply reel 201. The metal foil 200 is heated by contacting the stage 241 (heating element 29) upstream within the chamber 21, and then transported downstream.

[0099] A pressing member 25 is positioned at the location corresponding to the stage 241 to press the metal foil 200 toward the stage 241. The pressing member 25 is roll-shaped and supports the transport of the metal foil 200. The pressing member 25 may also be a heating element.

[0100] In another configuration, the stage 241 is not a heating element, while the retaining member 25 is a heating element.

[0101] The heated metal foil 200 is first brought into the first supply zone SZ1. In the first supply zone SZ1, the first gas G1 is supplied to both sides of the metal foil 200 from the first supply port 221, and molecules containing the second metal adhere to both sides of the metal foil 200.

[0102] Next, the metal foil 200 is brought into the first exhaust zone EZ1. In the first exhaust zone EZ1, inert gas G3 is supplied from the third supply port 223, and unreacted first gas G1 is exhausted from the first exhaust port 231.

[0103] Next, the metal foil 200 is brought into the second supply zone SZ2. In the second supply zone SZ2, the second gas G2 is supplied to both sides of the metal foil 200 from the second supply port 222. Molecules containing the second metal attached to both sides of the metal foil 200 react with the oxidizing agent, and a dielectric layer containing the oxide of the second metal is formed. As a result, a dielectric layer containing the oxide of the second metal is formed on both sides of the metal foil 200.

[0104] Finally, the metal foil 200 is brought into the second exhaust zone EZ2. In the second exhaust zone EZ2, inert gas G3 is supplied from the third supply port 223, and unreacted second gas G2 is exhausted from the second exhaust port 232.

[0105] After the metal foil 200 has been deposited with oxide of the desired thickness, it is discharged from the chamber 21 and wound onto a recovery reel 202. The recovery reel 202 is rotationally driven by a motor.

[0106] [Embodiments I-IV] Figure 7 is a conceptual side view showing the main parts of another film-forming apparatus according to the first embodiment. Film-forming apparatus 20B has the same configuration as film-forming apparatus 20A, except for the shape and arrangement of the heating elements.

[0107] In the film-forming apparatus 20B, the metal foil 200 unwound from the supply reel 201 is placed on a conveyor belt 28 and transported upstream to the chamber 21. Positioning members 243 are arranged on the conveyor belt 28 to fix and position the metal foil 200. One or more through holes 200a are formed in the metal foil 200, and the metal foil 200 is positioned by inserting the positioning members 243 into the through holes 200a. The positioning members 243 are heating elements 29. Therefore, the metal foil 200 is heated by contacting the positioning members 243 around the through holes 200a. After that, the metal foil 200 is detached from the conveyor belt 28 and transported to the first supply zone SZ1 by a conveyor roll 27. Thereafter, the metal foil 200 is processed in the same manner as in the film-forming apparatus 20A, and dielectric layers are formed on both sides.

[0108] [VIII Embodiment] Figure 8 is a conceptual side view showing another example of a film-forming apparatus according to the first embodiment. Film-forming apparatus 20C has the same configuration as film-forming apparatus 20A, except for the shape of the heating element.

[0109] In the film-forming apparatus 20C, the metal foil 200 unwound from the supply reel 201 is transported to the first supply zone SZ1 by a transport roll 27. The transport roll 27 is a heating element 29. Therefore, the metal foil 200 is transported and heated by the transport roll 27. A roll-shaped pressing member 25 is positioned at the location corresponding to the transport roll 27. The pressing member 25 may also be a heating element 29. Subsequently, the metal foil 200 is transported to the first supply zone SZ1. Thereafter, the metal foil 200 is processed in the same manner as in the film-forming apparatus 20A, and dielectric layers are formed on both sides.

[0110] [Embodiments I-vi] Figure 9 is a conceptual side view showing another example of a film-forming apparatus according to the first embodiment. The film-forming apparatus 20D includes a chamber 21 capable of supplying and exhausting a first gas and a second gas. The metal foil 200 is conveyed while being folded multiple times within the chamber 21. The number of folds is not particularly limited.

[0111] Chamber 21 comprises a first supply zone SZ1 to which a first gas G1 is supplied, a second supply zone SZ2 to which a second gas G2 is supplied, and an exhaust zone EZ for purging the first gas G1 and the second gas G2. Each zone is arranged to separate the chamber 21 along the conveying direction. The first supply zone SZ1 contains a plurality of first conveying rolls 271. The second supply zone SZ2 contains a plurality of second conveying rolls 272. At least one of the first conveying rolls 271 and the second conveying rolls 272 is a heating element 29. A third conveying roll 273 located in the exhaust zone EZ may also be a heating element 29.

[0112] The metal foil 200 is supplied upstream within the chamber 21 as it is unwound from the supply reel 201. The metal foil 200 is reoriented by the third transport roll 273 and transported into the first supply zone SZ1. In the first supply zone SZ1, the first gas G1 is supplied to both sides of the metal foil 200 from the first supply port 221, causing molecules containing the second metal to adhere to both sides of the metal foil 200.

[0113] The metal foil 200 is folded back on the first conveyor roll 271 and transported to the exhaust zone EZ. In the exhaust zone EZ, an inert gas G3 (e.g., nitrogen gas) is supplied from the third supply port 223, and unreacted first gas G1 is purged from the exhaust port 23. Exhaust ports may be added as needed, for example, to the first supply zone SZ1 and / or the second supply zone SZ2.

[0114] Next, the metal foil 200 is brought into the second supply zone SZ2. In the second supply zone SZ2, the second gas G2 is supplied to both sides of the metal foil 200 from the second supply port 222. Molecules containing the second metal attached to both sides of the metal foil 200 react with the oxidizing agent to produce oxides of the second metal. As a result, dielectric layers containing oxides of the second metal are formed on both sides of the metal foil 200.

[0115] The metal foil 200 is folded back by the second conveyor roll 272 and then transported back into the exhaust zone EZ. In the exhaust zone EZ, the unreacted second gas G2 is also purged from the exhaust port 23.

[0116] The metal foil 200 is then brought back into the first supply zone SZ1. Thereafter, the process of bringing the metal foil 200 into and out of the first supply zone SZ1, exhaust zone EZ, and second supply zone SZ2 is repeated, and an oxide of the desired thickness is deposited on the metal foil 200. Finally, the metal foil 200 is discharged from the chamber 21 and wound onto the recovery reel 202.

[0117] II. Second aspect In this embodiment, a voltage is applied to the metal foil in the presence of the first gas. This electrically attracts molecules containing the second metal to the metal foil, increasing the concentration of the second metal near the metal foil. As a result, the reaction efficiency is improved, and a uniform dielectric layer is formed. In addition, molecules containing the second metal are utilized efficiently. Furthermore, since the second metal is more easily adsorbed onto the metal foil, the density of the formed metal oxide-containing layer is improved.

[0118] [Film forming method] The film-forming method according to the second embodiment includes a first application step (hereinafter simply referred to as the application step) of applying a voltage to a metal foil in the presence of a first gas. Figure 10 is a flowchart of the film-forming method according to the second embodiment.

[0119] The film-forming method according to the second embodiment comprises the same steps as (iii) the first contact step and (iv) the second contact step in the film-forming method according to the first embodiment, except that it includes an application step instead of a heating step. The film-forming method according to the second embodiment may also include the same steps as (i) the surface modification step in the film-forming method according to the first embodiment.

[0120] (i) Surface modification process (S211) The surface of the metal foil may be modified in the same manner as in (i) the surface modification step in the film-forming method according to the first embodiment.

[0121] (ii) First contact step (S212) and application step (S214) In the film-forming method according to the first embodiment, (iii) the metal foil is brought into contact with a first gas containing a second metal, in the same manner as in the first contact step. At this time, a voltage is applied to the metal foil in contact with one or more first power supply units (hereinafter simply referred to as power supply units). The contact of the power supply units with the metal foil may be performed inside or outside the chamber.

[0122] Applying voltage to a metal foil is achieved by creating a potential difference between the electrode foil and the counter electrode. This voltage difference can be generated using a constant voltage, a pulsed voltage, a waveform with superimposed AC current, or other irregular waveforms. The voltage difference is not particularly limited. Preferably, the voltage difference is between 5V and 1000V, and more preferably between 10V and 800V. Within this range, the effects of voltage application are easily obtained, and damage to the metal foil and film-forming equipment is easily suppressed.

[0123] The metal foil may be used as the positive electrode and the voltage may be applied as the negative electrode. The polarity of the metal foil can be set appropriately according to the charge state of the first gas.

[0124] (iii) Second contact step (S213) The metal foil is brought into contact with the second gas in the same manner as in (iv) the second contact step in the film-forming method according to the first embodiment. As a result, a layer containing metal oxide is formed on the surface of the metal foil.

[0125] The order of each step is not particularly limited. Typically, the first gas is brought into contact with the metal foil, and then the second gas is brought into contact with the metal foil. The first and second contact steps may be repeated multiple times.

[0126] [Method for manufacturing electrode foil] A method for manufacturing an electrode foil according to the second embodiment includes an application step of applying a voltage to a metal foil in the presence of a first gas.

[0127] In the film-forming method and electrode foil manufacturing method according to the second embodiment, either a metal foil of a predetermined size or a long metal foil is the object to be film-formed. The electrode foil manufactured by the above method is suitably used as the anode of an electrolytic capacitor.

[0128] The method for manufacturing electrode foil according to the second embodiment will be described in detail step by step below. Figure 11 is a flowchart of the method for manufacturing electrode foil according to the second embodiment.

[0129] (1) Preparation process (S21) A metal foil similar to that described in the film-forming method according to the first embodiment is prepared. The metal foil may have other dielectric layers formed inside the pits formed by roughening.

[0130] (2) Surface roughening process (S22) Before the first contact step, the surface of the metal foil may be roughened. The roughening is carried out in the same manner as in step (2) roughening step in the electrode foil manufacturing method according to the first embodiment. Normally, if the surface of the metal foil is roughened in this manner, it is difficult to form a dielectric layer inside the pits by methods other than anodizing. By applying a voltage as in this embodiment, it becomes easy to form a uniform dielectric layer inside the pits. When forming a dielectric layer containing an oxide of the second metal and then anodizing it to form a third dielectric layer described later, it is preferable to perform this step. If the formed third dielectric layer has a porous structure, this step may be omitted.

[0131] The pore diameter of the pits formed on the surface of the metal foil is not particularly limited. The pore diameter is preferably between 50 nm and 2000 nm, as this tends to increase the surface area. From the viewpoint of contact between the metal foil and the power supply, the pore diameter is preferably not excessively large. The pore diameter is more preferably between 80 nm and 1300 nm. If the pore diameter is within this range, contact between the metal foil and the power supply becomes easier, and the voltage is more easily applied uniformly to the metal foil.

[0132] The thickness of the etching layer is not particularly limited and can be set appropriately according to the thickness of the metal foil. When the metal foil is used as the anode of an electrolytic capacitor, from the viewpoint of capacitance, the thickness of the etching layer is preferably 5 μm or more, and more preferably 15 μm or more. When the thickness of the etching layer is within this range, the effect of voltage application is easily obtained. From the viewpoint of the strength of the metal foil, the thickness of the etching layer is preferably 100 μm or less, and more preferably 80 μm or less.

[0133] (3) Surface modification process (S23) Before the first contact step, a surface modification treatment may be performed to modify the surface of the metal foil. The surface modification step is part of the film-forming method according to the first embodiment. (i) Surface modification work To the extent and It is done in the same manner.

[0134] (4) First contact step (S24) and application step (S26) (ii) The film-forming method according to the second embodiment is carried out in the same manner as the first contact step and the application step.

[0135] (5) Second contact process (S25) This is carried out in the same manner as (iii) the second contact step in the film-forming method according to the second embodiment. As a result, dielectric layers containing the oxide of the second metal are formed on both sides of the metal foil.

[0136] After forming the dielectric layer, the metal foil may be chemically treated. This forms a third dielectric layer between the metal foil and the dielectric layer, containing an oxide of the first metal constituting the metal foil. As a result, the dielectric layer as a whole is more easily formed, having a uniform thickness and no pinholes. The method for chemically treating the metal foil is not particularly limited. Chemical treatment can be carried out, for example, by anodic oxidation.

[0137] III. Third aspect In this embodiment, a voltage is applied to the metal foil in the presence of a second gas. This electrically attracts the oxidizing agent to the metal foil, increasing the oxygen concentration near the metal foil. As a result, the metal foil becomes more susceptible to oxidation, and a uniform dielectric layer is formed. In addition, the oxidizing agent is used efficiently. Furthermore, because the oxidizing agent is more easily adsorbed onto the metal foil, the density of the formed layer containing the metal oxide is improved.

[0138] [Film forming method] The film-forming method according to the third embodiment includes a second application step (hereinafter simply referred to as the application step) in which a voltage is applied to a metal foil in the presence of a second gas. Figure 12 is a flowchart of the film-forming method according to the third embodiment.

[0139] The film-forming method according to the third embodiment comprises the same steps as the film-forming method and electrode foil manufacturing method according to the second embodiment, except that a voltage is applied in the presence of a second gas instead of a first gas.

[0140] (i) Surface modification process (S311) The surface of the metal foil may be modified in the same manner as in (i) the surface modification step in the film-forming method according to the second embodiment.

[0141] (ii) First contact step (S312) (ii) In the film-forming method according to the second embodiment, the metal foil is brought into contact with the first gas containing the second metal in the same manner as in the first contact step.

[0142] (iii) Second contact step (S313) and application step (S314) The metal foil is brought into contact with the second gas in the same manner as in (iii) the second contact step in the film-forming method according to the first embodiment. At this time, a portion of the metal foil is brought into contact with one or more second power supply units (hereinafter simply referred to as power supply units), and a voltage is applied to the metal foil. As a result, a layer containing metal oxide is formed on the surface of the metal foil. The contact of the power supply units with the metal foil may be performed inside or outside the chamber.

[0143] The order of each step is not particularly limited. Typically, the first gas is brought into contact with the metal foil, and then the second gas is brought into contact with the metal foil. The first and second contact steps may be repeated multiple times.

[0144] After forming the dielectric layer, the metal foil may be chemically treated. This forms a third dielectric layer between the metal foil and the dielectric layer, containing an oxide of the first metal constituting the metal foil. As a result, the dielectric layer as a whole is more easily formed, having a uniform thickness and no pinholes. The method for chemically treating the metal foil is not particularly limited. Chemical treatment can be carried out, for example, by anodic oxidation.

[0145] [Method for manufacturing electrode foil] A method for manufacturing an electrode foil according to the third embodiment includes an application step of applying a voltage to a metal foil in the presence of a second gas.

[0146] In the third embodiment of the film-forming method and electrode foil manufacturing method, either a metal foil of a predetermined size or a long metal foil is the object to be film-formed. The electrode foil manufactured by the above method is suitably used as the anode of an electrolytic capacitor.

[0147] The manufacturing method for electrode foil according to the third embodiment will be described in detail step by step below. Figure 13 is a flowchart of the manufacturing method for electrode foil according to the third embodiment.

[0148] (1) Preparation process (S31) A metal foil similar to that described in the film-forming method according to the first embodiment is prepared. The metal foil may have other dielectric layers formed inside the pits formed by roughening.

[0149] (2) Surface roughening process (S32) The surface of the metal foil may be roughened before the first contact step. The roughening is carried out in the same manner as in step (2) roughening step in the method for manufacturing electrode foil according to the first embodiment.

[0150] (3) Surface modification process (S33) Prior to the first contact step, a surface modification treatment may be performed to modify the surface of the metal foil. The surface modification step is carried out in the same manner as (i) the surface modification step in the film-forming method according to the first embodiment.

[0151] (4) First contact step (S34) (ii) The film-forming method according to the third embodiment is carried out in the same manner as the first contact step.

[0152] (5) Second contact step (S35) and second application step (S36) (iii) The second contact step and the second application step are carried out in the same manner as in the film-forming method according to the third embodiment.

[0153] The voltage may be applied to the electrode foil in the presence of both the first gas and the second gas. This allows for the formation of an even more uniform layer. Figure 14 is a flowchart illustrating the film formation method according to this embodiment. Figure 15 is a flowchart illustrating the method for manufacturing the electrode foil according to this embodiment.

[0154] This embodiment differs from the second embodiment in that (iii) a voltage is applied to the metal foil in the second contact step as well, and from the third embodiment in that a voltage is applied to the metal foil in the first contact step as well. Otherwise, this embodiment has the same steps as the second and third embodiments.

[0155] [Film forming equipment] The film-forming apparatus according to the second and third embodiments comprises a power supply that contacts a portion of the metal foil to be film-formed, and a counter electrode that generates a voltage difference between the metal foil and the power supply. The first gas and the second gas are supplied so as to contact both main surfaces of the metal foil.

[0156] (power feeder) The power supply units (first and second power supply units) contact a portion of the metal foil, which is the object to be film-formed, and apply a voltage to the metal foil. There may be one or more power supply units, or two or more. The shape of the power supply units is not particularly limited, as long as they can contact the metal foil over a certain area.

[0157] The power supply may be, for example, a supply reel and / or a recovery reel, a stage supporting the metal foil, a transport roll, or a positioning member for positioning the metal foil. When forming a film by roll-to-roll, the power supply may be located inside or outside the chamber. In terms of minimizing energy loss, it is preferable to place the power supply inside the chamber, particularly near the point of contact between the metal foil and the first and / or second gas. On the other hand, considering ease of maintenance and freedom of equipment design, it is preferable to place the power supply outside the chamber.

[0158] (Opposite poles) The counter electrode is used together with the power supply to generate a voltage difference between the metal foil and the power supply. The placement of the counter electrode is not particularly limited, and it is sufficient as long as it is in a location where voltage is applied to at least both sides of the metal foil. The counter electrode does not have to face the main surface of the metal foil. There may be one or more counter electrodes, or two or more. The shape of the counter electrode is also not particularly limited.

[0159] The distance between the metal foil and the counter electrode is not particularly limited. Preferably, the distance between the metal foil and the counter electrode is 0.5 mm or more and 500 mm or less. When the distance between the metal foil and the counter electrode is within this range, it is easier to maintain a constant distance between the metal foil and the counter electrode when transporting the metal foil. Therefore, it is easier to avoid localized increases in the applied voltage and contact between the metal foil and the counter electrode. Furthermore, it becomes easier to form a uniform layer. More preferably, the distance between the metal foil and the counter electrode is 1 mm or more and 200 mm or less, and particularly preferably 1 mm or more and 130 mm or less. When the distance between the metal foil and the counter electrode is within this range, the equipment can be made smaller and energy loss can be reduced. If there are multiple counter electrodes, the distance between the metal foil and each counter electrode does not have to be the same.

[0160] If there are multiple chambers, the counter pole only needs to be located in at least one of these chambers.

[0161] The film-forming apparatus according to the second and third embodiments includes a chamber, pressure control unit, supply port, and exhaust port, similar to the film-forming apparatus according to the first embodiment, except that it is equipped with a power supply unit instead of a heating element. The film-forming apparatus according to the second and third embodiments may also include a support, a pressing member, etc., as in the film-forming apparatus according to the first embodiment.

[0162] The second embodiment is performed when a voltage is applied to the power supply while the metal foil is in contact with the first gas. The third embodiment is performed when a voltage is applied to the power supply while the metal foil is in contact with the second gas.

[0163] The film-forming method and film-forming apparatus according to the second and third embodiments can use a metal foil of a predetermined size as the object to be film-formed, or a long metal foil as the object to be film-formed. The long metal foil is, for example, transported in a chamber, and a dielectric layer is continuously formed on the transported metal foil.

[0164] Hereinafter, similar to the first embodiment, the film-forming apparatuses according to the second and third embodiments will be described separately for batch-type and roll-to-roll-type systems.

[0165] A. Batch method In this embodiment, the power supply (first and / or second power supply) is, for example, a stage. A counter electrode is placed near the metal foil. By placing the metal foil on the stage in the chamber, it is possible to apply a voltage to the metal foil, thereby generating a potential difference between the metal foil and the counter electrode. The stage is in contact with a portion of the metal foil.

[0166] [Embodiment II-i] Figure 16 is a conceptual side view showing an example of a film-forming apparatus according to the second and third embodiments, which is used in a batch system.

[0167] The film-forming apparatus 30 has the same configuration as the film-forming apparatus 10A shown in Figure 4, except that it includes a stage 34 that also serves as a power supply 39 and a counter electrode 38, instead of a stage that also serves as a heating element.

[0168] In other words, the film-forming apparatus 30 includes a chamber 31. The chamber 31 includes a first supply port 321, a second supply port 322, and an exhaust port 33. The pressure inside the chamber 31 is controlled by a pressure control unit 36. The metal foil 300 is pressed toward the stage 34 by a pressing member 35.

[0169] The film-forming apparatus 30 is further equipped with a voltage regulator 303 and an AC power supply 304. However, these are optional.

[0170] The counter electrode 38 is arranged so that a voltage is applied to both sides of the metal foil with a single electrode. However, the arrangement of the counter electrodes is not limited to this; for example, multiple counter electrodes may be arranged so that they face both main surfaces of the metal foil. When multiple counter electrodes are arranged, it is preferable to arrange them so that they are point-symmetrical or line-symmetrical with respect to the metal foil.

[0171] B. Roll-to-roll system In this embodiment, a voltage is applied to the metal foil being transported. The power supply is located inside or outside the chamber. The power supply may be a supply or recovery reel, a transport roll, a positioning member for positioning the metal foil being transported, or a stage for supporting the metal foil being transported.

[0172] When supplying and exhausting the first and second gases within a single chamber, the chamber may be divided into multiple sections, similar to the first embodiment. The metal foil may pass through each zone multiple times.

[0173] [Embodiment II-ii] Figure 17 is a conceptual side view showing an example of a film-forming apparatus according to the second and third embodiments, which is used in a roll-to-roll manner.

[0174] The film-forming apparatus 40A has the same configuration as the film-forming apparatus 20A shown in Figure 6, except that it includes a third transport roll 473 which also serves as a power supply 49 and a counter electrode 48, instead of a stage which also serves as a heating element.

[0175] In other words, the film-forming apparatus 40A includes a chamber 41. The chamber 41 includes a first supply zone SZ1 to which the first gas G1 is supplied, a second supply zone SZ2 to which the second gas G2 is supplied, a first exhaust zone EZ1 for purging the first gas G1, and a second exhaust zone EZ2 for purging the second gas G2. The zones are arranged in this order so as to separate the chamber 21 in a direction intersecting the conveying direction. Each zone is appropriately provided with a first supply port 421, a second supply port 422, a third supply port 423, a first exhaust port 431, and a second exhaust port 432. Purge from each exhaust port is performed as needed. The exhaust port to be used should be determined as necessary.

[0176] Counter electrodes may be positioned at least once on each of the main surfaces of the metal foil. In this case, variations in the voltage applied to the metal foil are suppressed. The counter electrodes may be positioned within the first supply zone SZ1 and / or the second supply zone SZ2.

[0177] The pressure inside the chamber 41 is controlled by the pressure control unit 46 to create a reduced pressure atmosphere. The pressure control unit 46 may also control the pressure in each zone as appropriate. The metal foil 400 is wound on a supply reel 401 which is rotationally driven by a motor, and is supplied upstream into the chamber 41 as it is unwound from the supply reel 401. After processing, the metal foil 400 is recovered onto a recovery reel 402.

[0178] Upstream of the chamber 21, a third transport roll 473 is positioned to transport the metal foil 400. The third transport roll 473 is a power supply unit 49. The power supply unit 49 is positioned upstream of the first supply zone SZ1 within the chamber 41. The metal foil 400 is transported while being supported by the power supply unit 49 (third transport roll 473). The counter electrode 48 is positioned downstream of the power supply unit 49 and upstream of the first supply zone SZ1.

[0179] The counter electrode may be located in the first supply zone SZ1, which is the most upstream. The counter electrode may also be located in at least one other location within the first exhaust zone EZ1, the second supply zone SZ2, and the second exhaust zone EZ2.

[0180] The film-forming apparatus 40A is equipped with a pressing member 45, although these are optional. The pressing member 45 is roll-shaped and supports the transport of the metal foil 400. The film-forming apparatus 40A is further equipped with a voltage regulator 403 and an AC power supply 404, although these are optional.

[0181] In another configuration, the retaining member 45 is the power supply. In this case, it is preferable that the third conveyor roll 473 is not the power supply. When voltage is applied to adjacent members, a potential difference is created between those members, which may cause the members to corrode.

[0182] [Second-iiith embodiment] Figure 18 is a conceptual side view showing yet another film-forming apparatus according to the second and third embodiments. Film-forming apparatus 40B has the same configuration as film-forming apparatus 40A, except for the arrangement of the power supply, the number and arrangement of the counter electrodes.

[0183] The power supply unit 49 consists of a supply reel 401 and a recovery reel 402, and is located outside the chamber 41. The power supply unit 49 may consist of either the supply reel 401 or the recovery reel 402. Two counter electrodes 48 are located in the first supply zone SZ1 and two in the second supply zone SZ2. In each zone, the two counter electrodes 48 are positioned opposite each other with a metal foil 400 in between.

[0184] [Embodiment II-iv] Figure 19 is a conceptual side view showing yet another film-forming apparatus according to the second and third embodiments. Film-forming apparatus 40C has the same configuration as film-forming apparatus 20D shown in Figure 9, except that the supply reel 401 and the recovery reel 402 also serve as the power supply 49, and that it is equipped with a plurality of counter electrodes 48.

[0185] In other words, the film-forming apparatus 40C is equipped with a chamber 41. The metal foil 400 is transported while being folded multiple times within the chamber 41. The number of folds is not particularly limited.

[0186] Chamber 41 includes a first supply port 421 for supplying the first gas G1 to the first supply zone SZ1, a fourth supply port 424 for supplying the fourth gas G4 (second gas G2 or inert gas G3) to the fourth supply zone SZ4, and a fifth supply port 425 for supplying the fifth gas G5 (first gas G1, inert gas G3 or other first gas G1) to the fifth supply zone SZ5.

[0187] Multiple first conveyor rolls 471 are located in the first supply zone SZ1. Multiple third conveyor rolls 473 are located in the fourth supply zone SZ4. Multiple second conveyor rolls 472 are located in the fifth supply zone SZ5.

[0188] Chamber 41 includes a first exhaust port 431 for discharging the first gas G1 from the first supply zone SZ1, a fourth exhaust port 434 for discharging the fourth gas G4 from the fourth supply zone SZ4, and a fifth exhaust port 435 for discharging the fifth gas G5 from the fifth supply zone SZ5.

[0189] The power supply unit 49 consists of a supply reel 401 and a retrieval reel 402, and is located outside the chamber 41. The power supply unit 49 may be either the supply reel 401 or the retrieval reel 402. At least one of the first conveyor roll 471, the second conveyor roll 472, and the third conveyor roll 473 may also be the power supply unit.

[0190] Two counter electrodes 48 are located in the first supply zone SZ1 and two in the fourth supply zone SZ4. In each zone, the two counter electrodes 48 are positioned opposite each other with the metal foil 400 in between.

[0191] [Embodiment II-v] Figure 20 is a conceptual side view showing yet another film-forming apparatus according to the second and third embodiments. Film-forming apparatus 40D has the same configuration as film-forming apparatus 40C shown in Figure 19, except for the shape and arrangement of the counter electrode 48.

[0192] The three counter electrodes 48 are all long, and their longitudinal direction is arranged so that each supply zone is from the supply reel 401 to the recovery reel 402. The counter electrodes 48 have multiple slits (not shown) through which the metal foil can pass. The inner walls of the slits function as counter electrodes. When the metal foil passes through the slits, a potential difference is created between the inner walls and the metal foil. The counter electrodes 48 only need to be placed in any one of the supply zones.

[0193] The size of the counter electrode 48 is not particularly limited. Considering the degree of freedom in apparatus design and gas flow, it is desirable that the counter electrode 48 be small enough not to divide the chamber 41 into multiple chambers. The size of the counter electrode 48 is, for example, less than 80% of the bottom area of ​​the film deposition apparatus 40D.

[0194] [Embodiments II-vi] Figure 21 is a conceptual side view showing yet another film-forming apparatus according to the second and third embodiments. Film-forming apparatus 40E has the same configuration as film-forming apparatus 40C shown in Figure 19, except that the chamber 41 also serves as the counter electrode 48. The inner wall of the chamber 41 is conductive. An arbitrary point on the inner wall is used as a contact point to create a potential difference between it and the metal foil 400.

[0195] IV. Fourth aspect In this embodiment, the metal foil is heated, and a voltage is applied to the metal foil in the presence of at least one of the first gas and the second gas. This efficiently forms a uniform dielectric layer.

[0196] [Film forming method] The film-forming method according to the fourth embodiment includes a heating step of heating a metal foil and an application step of applying a voltage to the metal foil in the presence of at least one of a first gas and a second gas. Figure 22 is a flowchart of the film-forming method according to the fourth embodiment.

[0197] The heating and voltage application steps are carried out in the same manner as the film-forming methods according to the first, second, and third embodiments. The first contact step may be carried out while heating the metal foil to which the voltage is applied. The second contact step may be carried out while heating the metal foil to which the voltage is applied. The metal foil may be heated by the heat generated by the power supply.

[0198] [Method for manufacturing electrode foil] The method for manufacturing an electrode foil according to the fourth embodiment includes a heating step of heating a metal foil and an application step of applying a voltage to the metal foil in the presence of at least one of a first gas and a second gas. Figure 23 is a flowchart showing the method for manufacturing an electrode foil according to the fourth embodiment. The heating step and the application step are carried out in the same manner as the film-forming method according to the first, second, and third embodiments.

[0199] [Film forming equipment] The film-forming apparatus according to the fourth embodiment comprises a heating element arranged in a chamber and in contact with a portion of the metal foil to be formed, thereby heating the metal foil; a power supply element in contact with a portion of the metal foil; and a counter electrode that generates a voltage difference between the metal foil and the power supply element. The first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

[0200] The film-forming apparatus according to the fourth embodiment includes a chamber, pressure control unit, supply port, and exhaust port, similar to those of the film-forming apparatus according to the first to third embodiments. The film-forming apparatus according to the fourth embodiment further includes a heating element similar to that of the film-forming apparatus according to the first embodiment, and a power supply and counter electrode similar to those of the film-forming apparatus according to the second and third embodiments. The film-forming apparatus according to the fourth embodiment may also include a support, a pressing member, etc., as in the film-forming apparatus according to the first to third embodiments.

[0201] [Embodiment IV] Figure 24 is a conceptual side view showing an example of a film-forming apparatus according to the fourth embodiment. The film-forming apparatus 50 has the same configuration as the film-forming apparatus 20A shown in Figure 6, except that it includes a supply reel 501 which also serves as a power supply 59 and a counter electrode 58, similar to the film-forming apparatus 40B shown in Figure 18.

[0202] In other words, the film-forming apparatus 50 includes a chamber 51. The chamber 51 includes a first supply zone SZ1 to which a first gas G1 is supplied, a second supply zone SZ2 to which a second gas G2 is supplied, a first exhaust zone EZ1 for purging the first gas G1, and a second exhaust zone EZ2 for purging the second gas G2. The zones are arranged in this order so as to separate the chamber 51 in a direction intersecting the conveying direction. Each zone is appropriately provided with a first supply port 521, a second supply port 522, a third supply port 523, a first exhaust port 531, and a second exhaust port 532. Purge from each exhaust port is performed as needed. The exhaust port to be used can be determined as necessary.

[0203] The pressure inside the chamber 51 is controlled by the pressure control unit 56 to create a reduced pressure atmosphere. The pressure control unit 56 may also control the pressure in each zone as appropriate. The metal foil 500 is wound onto a supply reel 501 which is rotationally driven by a motor, and as it is unwound from the supply reel 501, it flows upstream into the chamber 51. side The metal foil 500 is supplied to the supply reel 501 and the recovery reel 502. The supply reel 501 and the recovery reel 502 are powered by the power supply unit 59. 。

[0204] Opposite 58 It is located within the first supply zone SZ1, which is the most upstream. There are Opposite 58 Furthermore, it may be located in at least one place within the first exhaust zone EZ1, the second supply zone SZ2, and the second exhaust zone EZ2. Furthermore, the counter electrode 58 may be located downstream of the power supply unit 59 and upstream of the first supply zone SZ1.

[0205] Upstream of the chamber 51 is a stage 541 that supports the metal foil 500 being transported. The stage 541 is a heating element 60. A pressing member 55 is positioned opposite the stage 541 to press the metal foil 500 toward the stage 541. The pressing member 55 is also a heating element 60. The pressing member 55 is roll-shaped and supports the transport of the metal foil 500.

[0206] The film-forming apparatus 50 is further equipped with a voltage regulator 503 and an AC power supply 504. However, these are optional. [Industrial applicability]

[0207] The electrode foil manufactured by the method according to the present invention can be used in electrolytic capacitors for various applications to improve capacitance and voltage resistance. [Explanation of symbols]

[0208] 10A, 10B: Film forming equipment 11: Chamber 121: 1st supply port 122:Second supply port 13: Exhaust vent 14: Stage 15: Retaining member 16: Pressure Control Unit 19: Heating element 100: Metal foil

[0209] 20A, 20B, 20C, 20D: Film forming equipment 21: Chamber 221: 1st supply port 222:Second supply port 223: 3rd supply port 23: Exhaust vent 231: First exhaust port 232: Second exhaust port 241: Stage 243: Positioning member 25: Retaining member 26: Pressure Control Unit 27: Conveyor Roll 271: First conveyor roll 272: Second conveyor roll 273: Third conveyor roll 28: Conveyor belt 29: Heating element 201: Supply Reel 202: Recovery reel 200: Metal foil 200a: Through hole

[0210] 30: Film forming equipment 31: Chamber 321: 1st supply port 322:Second supply port 33: Exhaust vent 34: Stage 35: Retaining member 36: Pressure Control Unit 38: Opposite 39: Power feeder 303: Voltage Regulator 304: AC power supply 300: Metal foil

[0211] 40A, 40B, 40C, 40D, 40E: Film forming equipment 41: Chamber 421: 1st supply port 422:Second supply port 423: 3rd supply port 424: 4th supply port 425: 5th supply port 431: First exhaust port 432: Second exhaust port 434: Exhaust port #4 435: Fifth exhaust port 45: Retaining member 46: Pressure Control Unit 471: First conveyor roll 472: Second conveyor roll 473: Third conveyor roll 48: Opposite 49: Power feeder 401: Supply Reel 402: Retrieval reel 403: Voltage Regulator 404: AC power supply 400: Metal foil

[0212] 50: Film forming equipment 51: Chamber 521: 1st supply port 522:Second supply port 523: 3rd supply port 531: First exhaust port 532: Second exhaust port 541: Stage 55: Pressing member 56: Pressure control unit 58: Counter electrode 59: Current feeder 60: Heating element 501: Supply reel 502: Take-up reel 503: Voltage regulator 504: AC power supply 500: Metal foil

Claims

1. A heating step in which a portion of a metal foil containing a first metal is brought into contact with one or more heating elements to heat the metal foil, A first contact step involves bringing a first gas containing a second metal into contact with both sides of the metal foil while a portion of the metal foil is supported, The process includes a second contact step in which a second gas containing an oxidizing agent is brought into contact with both sides of the metal foil while a portion of the metal foil is supported, The heating step is performed by pressing the metal foil toward the one or more heating elements with a pressing member positioned at a location corresponding to the one or more heating elements. The aforementioned pressing member is a heating element, and the method for forming a film containing a metal oxide layer.

2. The film-forming method according to claim 1, wherein in the first contact step, a portion of the metal foil is supported by one or more heating elements.

3. The film-forming method according to claim 1 or 2, wherein in the second contact step, a portion of the metal foil is supported by the one or more heating elements.

4. The film-forming method according to any one of claims 1 to 3, wherein the one or more heating elements are conveying rolls.

5. The method for forming a film according to any one of claims 1 to 4, wherein in the heating step, the metal foil is brought into contact with two or more of the one or more heating elements.

6. The film-forming method according to any one of claims 1 to 5, wherein the heating step and the first contact step are performed in the same chamber space.

7. The film-forming method according to any one of claims 1 to 6, further comprising a surface modification step of modifying the surface of the metal foil before the first contact step.

8. At least one chamber, A pressure control unit that controls the pressure inside the chamber to create a reduced pressure atmosphere, The chamber is provided with a first supply port for supplying a first gas containing a second metal, A second supply port for supplying a second gas containing an oxidizing agent to the chamber, A first exhaust port for discharging the first gas from the chamber, A second exhaust port for discharging the second gas from the chamber, One or more heating elements are placed inside the chamber and contact a portion of the metal foil, which is the object to be film-formed, to heat the metal foil. The system includes a pressing member positioned at a location corresponding to the one or more heating elements, for pressing the metal foil toward the one or more heating elements, The aforementioned retaining member is a heating element, A film-forming apparatus in which the first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

9. The film-forming apparatus according to claim 8, wherein the one or more heating elements are conveying rolls.

10. The film-forming apparatus according to claim 8 or 9, comprising two or more of the one or more heating elements.

11. Preparation steps include preparing a metal foil containing a first metal, A roughening step in which both main surfaces of the metal foil are roughened, A heating step in which a portion of the roughened metal foil is brought into contact with one or more heating elements to heat the metal foil, A first contact step involves bringing a first gas containing a second metal into contact with both main surfaces of the metal foil while a portion of the metal foil is supported, The process includes a second contact step of forming a dielectric layer by bringing a second gas containing an oxidizing agent into contact with both main surfaces of the metal foil while a portion of the metal foil is supported, The heating step is performed by pressing the metal foil toward the one or more heating elements with a pressing member positioned at a location corresponding to the one or more heating elements. The aforementioned pressing member is a heating element, and the method is for manufacturing electrode foil.

12. The method for manufacturing an electrode foil according to claim 11, wherein in the first contact step, a portion of the metal foil is supported by one or more heating elements.

13. The method for manufacturing an electrode foil according to claim 11 or 12, wherein in the second contact step, a portion of the metal foil is supported by one or more heating elements.

14. The method for manufacturing an electrode foil according to any one of claims 11 to 13, wherein the one or more heating elements are transport rolls.

15. The method for manufacturing an electrode foil according to any one of claims 11 to 14, wherein in the heating step, the metal foil is brought into contact with two or more of the one or more heating elements.

16. A first contact step involves bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal, A second contact step involves bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil, A method for forming a layer containing a metal oxide, comprising: a first application step of applying a voltage to the metal foil in the presence of a first gas by bringing a portion of the metal foil into contact with one or more first power supply bodies and generating a potential difference between the metal foil and the counter electrode of the first power supply body.

17. The film-forming method according to claim 16, wherein in the first contact step, a portion of the metal foil is supported by the first power supply.

18. The film-forming method according to claim 16 or 17, wherein the first power supply is a conveying roll.

19. The film-forming method according to any one of claims 16 to 18, wherein in the first application step, the metal foil is brought into contact with two or more of the first power supply bodies.

20. A film-forming method according to any one of claims 16 to 19, comprising a second application step of applying a voltage to the metal foil in the presence of the second gas by bringing a portion of the metal foil into contact with one or more second power supply bodies and generating a potential difference between the metal foil and the counter electrode of the second power supply body.

21. The film-forming method according to claim 20, wherein in the second contact step, a portion of the metal foil is supported by the second power supply.

22. The film-forming method according to claim 20 or 21, wherein the second power supply is a conveying roll.

23. The film-forming method according to any one of claims 20 to 22, wherein in the second application step, the metal foil is brought into contact with two or more of the second power supply bodies.

24. The method for forming a film according to any one of claims 16 to 23, wherein both surfaces of the metal foil are roughened.

25. The film-forming method according to any one of claims 16 to 24, further comprising a surface modification step of modifying both sides of the metal foil before the first contact step.

26. Preparation steps include preparing a metal foil containing a first metal, A roughening step in which both main surfaces of the metal foil are roughened, A first contact step involves bringing a first gas containing a second metal into contact with both main surfaces of the roughened metal foil, A second contact step involves bringing a second gas containing an oxidizing agent into contact with both main surfaces of the metal foil, A method for manufacturing an electrode foil, comprising: a first application step of applying a voltage to the metal foil in the presence of a first gas by bringing a portion of the metal foil into contact with one or more first power supply bodies and generating a potential difference between the metal foil and the counter electrode of the first power supply body.

27. The method for manufacturing an electrode foil according to claim 26, wherein in the first contact step, a portion of the metal foil is supported by the first power supply.

28. The method for manufacturing an electrode foil according to claim 26 or 27, wherein the first power supply is a transport roll.

29. A method for manufacturing an electrode foil according to any one of claims 26 to 28, wherein in the first application step, the metal foil is brought into contact with two or more first power supply bodies.

30. A method for manufacturing an electrode foil according to any one of claims 26 to 29, wherein the first application step and the first contact step are performed in the same chamber space.

31. A method for manufacturing an electrode foil according to any one of claims 26 to 30, comprising a second application step of applying a voltage to the metal foil in the presence of a second gas by bringing a portion of the metal foil into contact with one or more second power supply bodies and generating a potential difference between the metal foil and the counter electrode of the second power supply body.

32. The method for manufacturing an electrode foil according to claim 31, wherein in the second contact step, a portion of the metal foil is supported by the second power supply.

33. The method for manufacturing an electrode foil according to claim 31 or 32, wherein the second power supply is a transport roll.

34. The method for manufacturing an electrode foil according to any one of claims 31 to 33, wherein in the second application step, the metal foil is brought into contact with two or more second power supply bodies.

35. A method for manufacturing an electrode foil according to any one of claims 31 to 34, wherein the second application step and the second contact step are performed in the same chamber space.

36. A method for manufacturing an electrode foil according to any one of claims 26 to 35, further comprising a surface modification step of modifying both main surfaces of the metal foil before the first contact step.

37. A first contact step involves bringing a first gas containing a second metal into contact with both sides of a metal foil containing a first metal, A second contact step involves bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil, A method for forming a layer containing a metal oxide, comprising an application step of applying a voltage to the metal foil in the presence of the second gas by bringing a portion of the metal foil into contact with one or more power supply bodies and generating a potential difference between the metal foil and the counter electrode of the power supply body.

38. The film-forming method according to claim 37, wherein in the second contact step, a portion of the metal foil is supported by the power supply.

39. The film-forming method according to claim 37 or 38, wherein the power supply is a conveying roll.

40. The method for forming a film according to any one of claims 37 to 39, wherein both surfaces of the metal foil are roughened.

41. The film-forming method according to any one of claims 37 to 40, wherein the application step involves bringing the metal foil into contact with two or more of the power supply bodies.

42. The film-forming method according to any one of claims 37 to 41, further comprising a surface modification step of modifying both sides of the metal foil before the first contact step.

43. Preparation steps include preparing a metal foil containing a first metal, A roughening step in which both main surfaces of the metal foil are roughened, A first contact step involves bringing a first gas containing a second metal into contact with both main surfaces of the roughened metal foil, A second contact step involves bringing a second gas containing an oxidizing agent into contact with both main surfaces of the metal foil, A method for manufacturing an electrode foil, comprising: a second application step of applying a voltage to the metal foil in the presence of a second gas by bringing a portion of the metal foil into contact with one or more second power supply bodies and generating a potential difference between the metal foil and the counter electrode of the second power supply body.

44. The method for manufacturing an electrode foil according to claim 43, wherein in the second contact step, a portion of the metal foil is supported by the second power supply.

45. The method for manufacturing an electrode foil according to claim 43 or 44, wherein the second power supply is a transport roll.

46. The method for manufacturing an electrode foil according to any one of claims 43 to 45, wherein in the second application step, the metal foil is brought into contact with two or more second power supply bodies.

47. A method for manufacturing an electrode foil according to any one of claims 43 to 46, further comprising a surface modification step of modifying both main surfaces of the metal foil before the first contact step.

48. At least one chamber, A pressure control unit that controls the pressure inside the chamber to create a reduced pressure atmosphere, The chamber is provided with a first supply port for supplying a first gas containing a second metal, A second supply port for supplying a second gas containing an oxidizing agent to the chamber, A first exhaust port for discharging the first gas from the chamber, A second exhaust port for discharging the second gas from the chamber, One or more power supply units that come into contact with a portion of the metal foil that is to be film-formed, It comprises a counter electrode that generates a voltage difference with respect to the metal foil, A film-forming apparatus in which the first gas and the second gas are supplied so as to be in contact with both main surfaces of the metal foil.

49. The film-forming apparatus according to claim 48, wherein the power supply is a conveying roll.

50. The film-forming apparatus according to claim 48 or 49, comprising two or more of the aforementioned power supply units.

51. A heating step in which a portion of a metal foil containing a first metal is brought into contact with one or more heating elements to heat the metal foil, A first contact step involves bringing a first gas containing a second metal into contact with both sides of the metal foil while a portion of the metal foil is supported, A second contact step involves bringing a second gas containing an oxidizing agent into contact with both sides of the metal foil while a portion of the metal foil is supported, A method for forming a layer containing a metal oxide, comprising: an application step of applying a voltage to the metal foil in the presence of at least one of the first gas and the second gas by bringing a portion of the metal foil into contact with one or more power supply bodies and generating a potential difference between the metal foil and the counter electrode of the power supply body.

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