Apparatus and method for manufacturing electrode foil for electrolytic capacitor

Abstract

The manufacturing device is a device for manufacturing an electrode foil for an electrolytic capacitor. This manufacturing device is provided with: a conveyance mechanism for conveying a strip-shaped metal foil having a porous part on the surface thereof; a head part for supplying and removing a raw material gas to form a dielectric layer on the porous part by an atomic layer deposition method; and a support tape that supports the metal foil from a side opposite to the head portion with the metal foil interposed therebetween in a film formation region where the dielectric layer is formed by the head portion. A dielectric layer is formed in a state in which the metal foil is conveyed. A contact portion of the support tape, which is in contact with the metal foil in the film formation region, moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film formation region.

Description

Technical Field

[0001] The present disclosure relates to a manufacturing apparatus and a manufacturing method for an electrode foil for an electrolytic capacitor. Background Art

[0002] An electrode foil for an electrolytic capacitor includes an etched foil (metal foil) whose surface has been roughened by etching and a dielectric layer covering the surface of the etched foil. The dielectric layer is usually formed by subjecting the etched foil to a chemical conversion treatment (anodic oxidation). On the other hand, a method of forming a dielectric layer by atomic layer deposition has also been proposed.

[0003] Patent Document 1 (U.S. Patent Application Publication No. 2013 / 0064977) discloses a method of forming atomic layers on a substrate using a drum including a deposition head (Japanese: film forming head). In this method, the substrate is conveyed in a manner that moves around the drum.

[0004] Patent Document 2 (U.S. Patent Application Publication No. 2012 / 0196050) discloses an apparatus that disposes heads on both sides of a substrate and deposits atomic layers on both sides of the substrate at the same time. This apparatus maintains a constant distance between the heads and the substrate by a gas bearing.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: U.S. Patent Application Publication No. 2013 / 0064977

[0008] Patent Document 2: U.S. Patent Application Publication No. 2012 / 0196050 Summary of the Invention

[0009] One aspect of the present disclosure relates to a manufacturing apparatus for an electrode foil for an electrolytic capacitor. The manufacturing apparatus includes: a conveying mechanism that conveys a strip-shaped metal foil having a porous portion on its surface; a head that supplies and removes a source gas to form a dielectric layer on the porous portion by atomic layer deposition; and a support belt that supports the metal foil from a side opposite to the head with the metal foil interposed therebetween in a film forming region where the dielectric layer is formed by the head. The dielectric layer is formed in a state where the metal foil is being conveyed, and a contact portion of the support belt that contacts the metal foil in the film forming region moves in a direction the same as the moving direction of the metal foil in a state of supporting the moving metal foil in the film forming region.

[0010] Another aspect of the present disclosure relates to a method for manufacturing an electrode foil for an electrolytic capacitor. The manufacturing method includes: a preparation step of disposing a strip-shaped metal foil having a porous portion on its surface on a conveying mechanism; and a layer formation step of forming a dielectric layer on the porous portion by atomic layer deposition while conveying the metal foil. The formation of the dielectric layer is performed using a head that supplies and removes a source gas to form the dielectric layer. The layer formation step is performed in a state where the metal foil is supported by a support belt from the side opposite to the head across the metal foil in a film formation region where the dielectric layer is formed using the head. In the layer formation step, a contact portion of the support belt that contacts the metal foil in the film formation region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film formation region.

[0011] According to the present disclosure, it is possible to manufacture an electrode foil (electrode foil for an electrolytic capacitor) having a dielectric layer with high uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a diagram schematically showing a configuration example of a manufacturing apparatus according to Embodiment 1.

[0013] Figure 2 is schematically showing Figure 1 a configuration example of a part of the manufacturing apparatus shown.

[0014] Figure 3 is schematically showing Figure 1 a top view showing an example of the arrangement of the metal foil and the support belt in the manufacturing apparatus shown.

[0015] Figure 4 is a diagram schematically showing a configuration example of another manufacturing apparatus according to Embodiment 1.

[0016] Figure 5 is a diagram schematically showing a configuration example of a manufacturing apparatus according to Embodiment 2. DETAILED DESCRIPTION

[0017] In the method of Patent Document 1, when using an etched foil with a large surface area as a substrate, a very long purge time is required, so the number of nozzles (ALD cycles) that can be provided on the drum is limited. As a result, in order to ensure the required number of cycles, it is necessary to make the conveying speed of the substrate very slow or make the drum diameter very large. However, in mass production, neither method is feasible.

[0018] In the method of Patent Document 2, the gap between the substrate and the nozzle is maintained constant by bearing gas. However, in the case of using a wide and thin substrate such as an etched foil, it is difficult to maintain the gap constant and it is difficult to form a film uniformly.

[0019] Under such circumstances, the present disclosure provides an apparatus and a method for manufacturing an electrode foil (electrode foil for electrolytic capacitor) having a dielectric layer with high uniformity.

[0020] Hereinafter, embodiments of the present disclosure will be exemplified, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials are sometimes exemplified, but other numerical values and other materials can also be applied as long as the effects of the present disclosure can be obtained. In this specification, the description "numerical value A to numerical value B" includes numerical value A and numerical value B, and can be replaced with "numerical value A or more and numerical value B or less". In the following description, when the lower limit and the upper limit of a numerical value related to a specific physical property, condition, etc. are exemplified, any one of the exemplified lower limits can be arbitrarily combined with any one of the exemplified upper limits as long as the lower limit is not more than the upper limit. In the following description, when examples of constituent elements and examples of methods are listed, unless otherwise specified, only one of the listed examples can be used, or a plurality of the listed examples can be used in combination.

[0021] (Apparatus for manufacturing an electrode foil for electrolytic capacitor)

[0022] The apparatus of the present embodiment is an apparatus for manufacturing an electrode foil for electrolytic capacitor. Hereinafter, this manufacturing apparatus may sometimes be referred to as "manufacturing apparatus (D)".

[0023] The manufacturing apparatus (D) includes a metal foil having a porous portion on the surface and a dielectric layer formed on the porous portion. The manufacturing apparatus (D) includes: a conveying mechanism that conveys a belt-shaped metal foil having a porous portion on the surface; a head that supplies and removes a raw material gas to form a dielectric layer on the porous portion by atomic layer deposition (ALD method); and a support belt that supports the metal foil from the side opposite to the head across the metal foil in the film formation region where the dielectric layer is formed. The dielectric layer is formed in a state where the metal foil is conveyed. The contact portion of the support belt that contacts the metal foil in the film formation region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film formation region.

[0024] In the manufacturing apparatus (D), since the dielectric layer is formed by the atomic layer deposition method, the dielectric layer can be formed with good uniformity up to a deeper part of the porous portion. According to the manufacturing apparatus (D), the dielectric layer can be continuously formed on the long strip metal foil with good productivity. In the manufacturing apparatus (D), in the film-forming region, the metal foil is supported by the support belt. Therefore, the distance between the head and the metal foil can be made constant, and a dielectric layer with high uniformity can be stably formed. In particular, even when the width of the metal foil is wide, it is easy to make the distance between the head and the metal foil constant. In addition, in the manufacturing apparatus (D), the above contact portion moves in the same direction as the moving direction of the metal foil. Therefore, deterioration of the metal foil due to friction between the metal foil and the support table can be suppressed.

[0025] The metal foil is not particularly limited as long as it is a metal foil that can be used for manufacturing the electrode foil in the manufacturing apparatus (D). In the manufacturing apparatus (D), the dielectric layer can be formed on a wide and long metal foil. The width of the metal foil is not limited and can be 5 cm or more (for example, 15 cm or more), or can be 100 cm or less. The length of the metal foil is not limited and can be 10 m or more (for example, 30 m or more), or can be 2000 m or less. The porous portion on the surface of the metal foil can be formed by a known method. For example, the porous portion can also be formed by etching a normal metal foil with a flat surface. Since the metal foil with a porous portion formed on the surface is available, they can also be used.

[0026] The metal foil generally includes a non-porous core portion and a porous portion formed on the outer side of the core portion. The porous portion is generally formed on both sides (two main surfaces) of the metal foil. However, when only one side of the metal foil is used, the porous portion can also be formed only on one side (one main surface) of the metal foil. The thickness of the porous portion is not particularly limited and can be selected according to the use of the electrolytic capacitor and the required characteristics.

[0027] The thickness of the porous portion on one side of the metal foil can be 5 μm or more, 10 μm or more, 15 μm or more, or 50 μm or more, and can be 200 μm or less, 150 μm or less, 100 μm or less, or 80 μm or less. When the metal foil is used as the anode of the electrolytic capacitor, from the viewpoint of capacitance, the thickness of the porous portion is preferably 5 μm or more, more preferably 15 μm or more. In addition, from the viewpoint of the strength of the metal foil, the thickness of the porous portion is preferably 100 μm or less, more preferably 80 μm or less. The thickness of the porous portion refers to the thickness formed on one main surface of the metal foil. The thickness of the porous portion can be measured by cutting the electrode foil (or metal foil) and taking an electron microscope photograph of the cross section.

[0028] The metal foil may be formed of a metal (first metal). The type of the first metal constituting the metal foil is not particularly limited, and the metal of the metal foil used in the electrode foil of the electrolytic capacitor may be used. Examples of the first metal include valve metals and alloys containing valve metals. Examples of valve metals include aluminum (Al), tantalum (Ta), niobium (Nb), and the like.

[0029] The dielectric layer is a dielectric layer that can be used for an electrode foil for an electrolytic capacitor. The thickness of the dielectric layer is not particularly limited, and is selected in consideration of the use and characteristics of the electrolytic capacitor. The thickness of the dielectric layer can be 1 nm or more, or 5 nm or more, or 300 nm or less, or 200 nm or less.

[0030] The dielectric layer may contain an oxide of a metal (second metal) or may be an oxide of a metal. The second metal contained in the dielectric layer may be the same as or different from the first metal. The second metal may be composed of the first metal and a metal other than the first metal.

[0031] Examples of the second metal include Al, Ta, Nb, silicon (Si), titanium (Ti), zirconium (Zr), hafnium (Hf), etc. The second metal may contain one metal element or two or more metal elements. The dielectric layer may contain at least one oxide selected from Al2O3, Ta2O5, Nb2O5, SiO2, TiO2, ZrO2 and HfO2. The dielectric layer may also be formed of two or more layers having different compositions. When the dielectric layer contains two or more oxides of the second metal, the two or more oxides may be mixed or may be configured in layers.

[0032] When the first metal and the second metal are different, from the viewpoint of increasing the capacitance of the electrolytic capacitor, the relative dielectric constant of the oxide of the second metal is preferably higher than the relative dielectric constant of the oxide of the first metal. In an example of a metal foil, the first metal is Al, and the second metal includes at least one selected from Ti, Si, Hf, Ta, and Nb. The second metal may also include Al and a metal other than Al.

[0033] The electrode foil manufactured by the manufacturing apparatus (D) may be used as an anode body having a dielectric layer formed thereon, or may be used as an electrode other than this.

[0034] The conveying mechanism is not particularly limited, and the same conveying mechanism as that used in the manufacturing method called roll-to-roll (Japanese: roll-to-roll) can be used. It should be noted that in this specification, the support belt is not included in the conveying mechanism. The conveying mechanism generally includes an unwinding roller (Japanese: 巻き出しロール) for delivering the wound metal foil and a winding roller (Japanese: 巻き取りロール) for winding the delivered metal foil. The dielectric layer is formed on the way from the unwinding roller to the winding roller.

[0035] The ratio Vm / Vb of the moving speed Vm of the metal foil in the film formation region to the moving speed Vb of the above contact portion in the film formation region can be in the range of 0.8 to 1.2 (for example, in the range of 0.9 to 1.1). By making their speeds substantially the same or the same, damage to the metal foil can be suppressed. In addition, it is easy to stably support the metal foil.

[0036] The manufacturing apparatus (D) may further include a heating device for heating the support belt. By heating the support belt, film formation can be performed while heating the metal foil with the support belt. According to this configuration, a dielectric layer with higher uniformity can be formed with good stability. The support belt only needs to be heated in such a way that at least the contact portion is heated. The method of heating the support belt is not particularly limited, and known heating methods can be used. For example, methods such as resistance heating, infrared heating, and induction heating can be used.

[0037] The manufacturing apparatus (D) may further include a chamber that surrounds the head, the metal foil passing through the film formation region, and the support belt passing through the film formation region. The film forming apparatus (D) may further include a heating device for heating the inside of the chamber. By heating the inside of the chamber, a dielectric layer with higher uniformity can be formed with good stability.

[0038] The method of heating the inside of the chamber is not particularly limited, and known heating methods can be used. For example, methods such as resistance heating, infrared heating, and induction heating can be used. The heating inside the chamber can be performed from the inside of the chamber or from the outside. Usually, the unwinding roller and the winding roller are arranged outside the chamber. In this case, the metal foil passes through the slit formed in the chamber and passes through the inside of the chamber. The inside of the chamber can be decompressed or not decompressed. They are selected according to the film formation conditions using the atomic layer deposition method.

[0039] The manufacturing apparatus (D) may further include an adsorption mechanism for adsorbing the metal foil to the support belt in the film formation region. According to this structure, the distance between the metal foil and the head can be made particularly constant, so a dielectric layer with higher uniformity can be formed. In this case, it is preferable that the moving speed Vm of the metal foil in the film formation region is the same as the moving speed Vb of the above contact portion in the film formation region.

[0040] In the manufacturing apparatus (D), a dielectric layer can be formed on only one side (one main surface) of the metal foil, or a dielectric layer can be formed on both sides (two main surfaces) of the metal foil. In the case of forming a dielectric layer on both sides of the metal foil, the porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil.

[0041] When dielectric layers are formed on both sides of a metal foil, the thickness and composition of the dielectric layer (the first dielectric layer) formed on one side are usually substantially the same as those of the dielectric layer (the second dielectric layer) formed on the other side. However, since the dielectric layers are formed by the ALD method, the first and second dielectric layers can also be formed with different thicknesses and / or compositions.

[0042] In the first example of the case where dielectric layers are formed on both sides of a metal foil, first, a metal foil with a dielectric layer formed on one side is wound around a take-up roll. Next, the wound metal foil is unwound, and in the film-forming region, a dielectric layer is formed on the other side of the metal foil. In this way, dielectric layers can be formed on both sides of the metal foil.

[0043] Hereinafter, a second example of the case where dielectric layers are formed on both sides of a metal foil will be described. In this case, as described above, the porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil. The head includes a first head for forming a dielectric layer on the first porous portion and a second head for forming a dielectric layer on the second porous portion. The film-forming region includes a first film-forming region and a second film-forming region. The support belt includes a first support belt for supporting the metal foil in the first film-forming region where the dielectric layer is formed by the first head, and a second support belt for supporting the metal foil in the second film-forming region where the dielectric layer is formed by the second head.

[0044] In the second example, the metal foil unwound from the unwind roll passes through the first film-forming region and the second film-forming region and is wound around the take-up roll. The first head and the second head form dielectric layers on different surfaces of the metal foil. That is, the first head forms a dielectric layer on the first porous portion, and the second head forms a dielectric layer on the second porous portion. In this case, the manufacturing apparatus (D) may also include a mechanism for inverting the upper and lower surfaces of the metal foil. For example, the manufacturing apparatus (D) may include a roll for inverting the metal foil. Examples of the specific configuration of the manufacturing apparatus (D) in this case will be described in Embodiment 2 below.

[0045] (Manufacturing method of electrode foil for electrolytic capacitor)

[0046] The manufacturing method of the present embodiment is a manufacturing method of an electrode foil for an electrolytic capacitor. Hereinafter, this manufacturing method may sometimes be referred to as "manufacturing method (M)". The manufacturing method (M) can be implemented using the manufacturing apparatus (D). Matters described for the manufacturing method (D) can be applied to the manufacturing method (M), so repeated descriptions may sometimes be omitted. Matters described for the manufacturing method (M) can also be applied to the manufacturing apparatus (D). According to the manufacturing method (M), the effects described in the manufacturing apparatus (D) can be obtained.

[0047] The manufacturing method (M) includes: a preparation process of disposing a strip-shaped metal foil having a porous portion on its surface on a conveying mechanism; and a layer formation process of forming a dielectric layer on the porous portion by atomic layer deposition while the metal foil is being conveyed. The formation of the dielectric layer is performed using a head that supplies and removes a source gas to form the dielectric layer. The layer formation process is performed in a state where a support belt supports the metal foil from the side opposite to the head across the metal foil in a film formation region where the dielectric layer is formed by the head. In the layer formation process, a contact portion of the support belt that contacts the metal foil in the film formation region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film formation region.

[0048] In the preparation process, for example, an unwinding roller around which the metal foil is wound is disposed on the conveying mechanism. Examples of the layer formation process will be described later. It should be noted that the manufacturing method (M) may include processes other than the preparation process and the layer formation process.

[0049] Regarding the manufacturing method (M), in the layer formation process, the ratio Vm / Vb of the moving speed Vm of the metal foil in the film formation region to the moving speed Vb of the above contact portion in the film formation region may be in the range of 0.8 to 1.2 (for example, in the range of 0.9 to 1.1).

[0050] Regarding the manufacturing method (M), in the layer formation process, the support belt may be heated. Regarding the manufacturing method (M), the head, the metal foil passing through the film formation region, and the support belt passing through the film formation region are surrounded by a chamber. And, in the layer formation process, the inside of the chamber may be heated.

[0051] Regarding the manufacturing method (M), the layer formation process may also be performed in the film formation region in a state where the metal foil is adsorbed on the support belt.

[0052] As described in the manufacturing apparatus (D), regarding the manufacturing method (M), a dielectric layer may be formed only on one side of the metal foil, or a dielectric layer may be formed on both sides of the metal foil. In this case, the dielectric layer may also be formed as described in the first and second examples above.

[0053] Hereinafter, an example of forming a dielectric layer as described in the second example will be described. In this case, the porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil. The head includes a first head for forming a dielectric layer on the first porous portion and a second head for forming a dielectric layer on the second porous portion. The film formation region includes a first film formation region and a second film formation region. The support belt includes a first support belt for supporting the metal foil in the first film formation region where the dielectric layer is formed by the first head and a second support belt for supporting the metal foil in the second film formation region where the dielectric layer is formed by the second head.

[0054] Hereinafter, a configuration example of the manufacturing apparatus (D) and the manufacturing method (M) will be described. However, the manufacturing apparatus (D) and the manufacturing method (M) are not limited to the examples described below. Regarding the configurations other than the characteristic configurations in the present disclosure, known configurations regarding the atomic layer deposition method and the apparatus used thereof can also be applied.

[0055] (Transport mechanism)

[0056] The transport mechanism for transporting the metal foil is not particularly limited, and a known transport mechanism can be used. The transport mechanism may include an unwinding roller and a winding roller. The transport mechanism may include, as needed, rollers for adjusting or changing the transport position and transport direction of the metal foil, a mechanism for adjusting the tension of the metal foil, and the like.

[0057] (Head)

[0058] The head includes a plurality of heads for supplying gases required for film formation and an exhaust path for removing (recovering) the supplied gases and the like. Specifically, the head may include a first head for supplying a gas (source gas) of a precursor, a second head for supplying an oxidant, a third head for supplying an inert gas for purging the precursor and the oxidant, etc., and a plurality of exhaust paths for removing the supplied gases and the like. The third head may be disposed so as to sandwich each of the first head and the second head. The exhaust paths may be disposed so as to sandwich each of the first head to the third head. One head group may include the first head, the second head, the third head, and the exhaust path. By one head group, a dielectric layer is formed in atomic layer units. In order to uniformly form a dielectric layer in the width direction of the metal foil, each head and the exhaust path extend in the width direction of the metal foil.

[0059] One head includes at least one head group, and usually includes a plurality of head groups. The plurality of head groups are arranged from the upstream side to the downstream side of the conveyance path of the metal foil. The manufacturing apparatus (D) may also include a plurality of heads arranged from the upstream side to the downstream side of the conveyance path of the metal foil. By increasing the number of heads and / or the number of head groups, the dielectric layer can be thickened. The number of head groups included in one head may be in the range of 1 to 700 (for example, in the range of 1 to 200).

[0060] The first head and the second head are connected to a device for supplying the supplied substance. For example, the first head portion may be connected to a storage cylinder of a precursor or the like via a mass flow controller. Each head includes a flow path for supplying a precursor or an oxidant. These flow paths may also be nozzle-shaped. Alternatively, the flow path may be a through hole formed in a plate-like member. In order to form a dielectric layer with good uniformity in the entire width direction of the metal foil, these flow paths are preferably formed uniformly in the width direction. For example, the flow path may be one through hole extending in the width direction. Alternatively, the flow path may be a plurality of through holes arranged at regular intervals in the width direction. The exhaust path is connected to an exhaust device. These devices are not particularly limited, and known devices can be used.

[0061] The manufacturing apparatus (D) may include a moving mechanism that moves the head in a reciprocating manner along the conveyance direction of the metal foil. Further, the head may be moved to form a dielectric layer. According to this configuration, a thicker dielectric layer can be formed with a smaller number of head groups, and miniaturization of the apparatus can be achieved.

[0062] (Support belt)

[0063] The support belt preferably supports substantially the entire metal foil in the film formation region. Specifically, it preferably supports 80% or more (for example, 90% or more) of the area of the metal foil in the film formation region, and may also support the entire metal foil. In a preferred example, the width of the support belt is wider than the width of the metal foil, and supports the entire lower surface of the metal foil in the film formation region.

[0064] The material of the support belt is not particularly limited, and from the viewpoint of heating the metal foil, the support belt is preferably mainly made of metal. An annular belt can be used for the support belt. The support belt may also be a single annular metal sheet. Alternatively, the support belt may be formed by arranging and connecting a plurality of elongated sheets along the circumferential direction of the belt.

[0065] Generally, the support belt is disposed below the metal foil, and the head is disposed above the metal foil. Thus, the metal foil can be supported by the support belt without using an adsorption mechanism or the like. As described above, the support belt can also adsorb the metal foil in the film formation region. In this case, the support belt includes an adsorption mechanism. The adsorption mechanism is not particularly limited, and a known method for adsorbing an article conveyed by a conveyor belt or the like can be used. In an example of the adsorption mechanism, a support belt formed with a plurality of fine through-holes is used, and the adsorption mechanism includes a decompression mechanism for decompressing the through-holes at the contact portion. According to this structure, the metal foil in contact with the contact portion is adsorbed. Alternatively, the adsorption mechanism can also be a mechanism that adsorbs the metal foil by static electricity. That is, the adsorption mechanism can adsorb the metal foil by decompression and / or static electricity.

[0066] The manufacturing apparatus (D) includes at least one film formation region. The manufacturing apparatus (D) includes at least one head and at least one support belt. In the case where the manufacturing apparatus (D) includes a plurality of film formation regions, the manufacturing apparatus (D) includes a plurality of heads. In this case, the manufacturing apparatus (D) can also include a plurality of support belts. Alternatively, the manufacturing apparatus (D) can also include one support belt extending in a plurality of film formation regions.

[0067] (Film formation process)

[0068] The dielectric layer is formed so as to cover at least a part of the porous portion. Typically, the dielectric layer is formed so as to cover the entire porous portion on one or both sides of the metal foil present in the portion used as an electrode.

[0069] In the case where the dielectric layer is formed by chemical conversion treatment, the metal contained in the dielectric layer becomes the metal constituting the metal foil. On the other hand, in the manufacturing apparatus (D) and the manufacturing method (M), since the dielectric layer is formed by atomic layer deposition, an oxide of a metal different from the metal of the metal foil can be used for the dielectric layer. Therefore, the selection range of the second metal is expanded, and various properties can be imparted to the dielectric layer.

[0070] Hereinafter, an example of the film formation process by the ALD method will be described. The formation of the dielectric layer is performed in a state where the metal foil is conveyed in the film formation region. It should be noted that the metal foil conveyed in the film formation region can also be heated to a predetermined temperature as needed. The metal foil can be heated to a range of 80°C to 550°C (for example, a range of 90°C to 400°C) as needed. The film formation region can be decompressed or can be at atmospheric pressure.

[0071] In the layer formation process, first, a gas (source gas) of a precursor is supplied from the first head to the surface (porous part) of the metal foil. The precursor is deposited in atomic layer units. Next, unnecessary precursors, etc. are removed (purged). Next, an oxidant is supplied from the second head to the surface of the metal foil. Next, unnecessary oxidants, substances generated by the reaction, etc. are removed (purged). The supply of the precursor → purge → supply of the oxidant → purge is defined as one cycle, and an extremely thin dielectric layer is formed in this one cycle. To correspond to this one cycle, one head group includes a first head for supplying the precursor, a second head for supplying the oxidant, a third head for supplying an inert gas for purging, and a plurality of exhaust paths for discharging the supplied gases, etc. By increasing the number of head groups contained in one head, the thickness of the dielectric layer formed by one head can be increased. In addition, by increasing the number of heads, the thickness of the formed dielectric layer can be increased.

[0072] The precursor is selected according to the composition of the dielectric layer. As the precursor, an organic compound containing a second metal contained in the dielectric layer can be used. The organic compound is not particularly limited, and an organic compound that has been conventionally used in the ALD method can be used.

[0073] Examples of the precursor containing Al include trimethylaluminum ((CH3)3Al), etc. Examples of the precursor containing Ta include (tert-butylimino)tris(methylethylamino)tantalum(V) (C 13 H 33 N4Ta, TBTEMT), tantalum(V) pentaethoxide (Ta(OC2H5)5), etc.

[0074] Examples of the precursor containing Nb include niobium(V) ethoxide (Nb(OCH2CH3)5, tris(diethylamino)(tert-butylimino)niobium(V) (C 16 H 39 N4Nb), etc. Examples of the precursor containing Si include N-sec-butyl(trimethylsilyl)amine (C7H 19 NSi), tetraethylsilane (Si(C2H5)4), tetraethoxysilane (Si(OC2H5)4), silicon tetrachloride (SiCl4), etc.

[0075] Examples of the precursor containing Ti include tetrakis(dimethylamino)titanium(IV) ([(CH3)2N]4Ti, TDMAT), titanium tetrachloride (TiCl4), titanium(IV) ethoxide (Ti[O(C2H5)]4), etc. Examples of the precursor containing Zr include tetrakis(methylethylamino)zirconium(IV) (Zr(NCH3C2H5)4), zirconium(IV) tert-butoxide (Zr[OC(CH3)3]4), etc.

[0076] Examples of the Hf-containing precursor include hafnium tetrachloride (HfCl4), hafnium tetrakis(dimethylamino) (Hf[N(CH3)2]4), hafnium tert-butoxide (Hf[OC(CH3)3]4), and the like.

[0077] Examples of the oxidizing agent include water, oxygen, ozone, and the like. The oxidizing agent can be supplied to the surface of the metal foil as a plasma using the oxidizing agent as a raw material. The inert gas for purging is not particularly limited, and a known inert gas (such as nitrogen gas) can be used.

[0078] Hereinafter, an example of the manufacturing apparatus (D) and an example of the manufacturing method (M) using the manufacturing apparatus (D) will be specifically described with reference to the drawings. The examples described below can be changed based on the above description. In addition, the matters described below can also be applied to the above-described embodiments.

[0079] (Embodiment 1)

[0080] In Embodiment 1, an example of the manufacturing apparatus (D) will be described. The configuration of the manufacturing apparatus 100 of Embodiment 1 is schematically shown in Figure 1 ... The manufacturing apparatus 100 includes a conveying mechanism 110, a head 120, and a support belt 130. It should be noted that the manufacturing apparatus 100 may also include a chamber (the same applies to the following manufacturing apparatuses). The chamber can be configured to surround at least a part of the conveying mechanism 110, the head 120, and the support belt 130, or can be configured to surround all of them.

[0081] The conveying mechanism 110 includes an unwinding roller 111, a position adjusting roller 112, and a winding roller 113. The metal foil is wound by the winding roller 113, and accordingly, the metal foil is unwound by the unwinding roller 111, thereby conveying the metal foil in the direction of arrow A.

[0082] An enlarged view schematically showing the configuration of the head 120 is shown in Figure 2 ... In Figure 2 ..., the conveying direction of the metal foil is indicated by arrow A. In one example shown in Figure 2 ..., the head 120 includes two head groups 121 arranged along the conveying direction of the metal foil, but may include more head groups. Each head group 121 includes a first head 121a, a second head 121b, a plurality of third heads 121c, and a plurality of exhaust paths 121d. The arrows in each head and the exhaust path indicate the gas flow. It should be noted that in Figure 2In the head 120 of an example shown, in the region between the second head 121b of the upstream-side head group 121 and the first head 121a of the downstream-side head group 121 among two adjacent head groups 121, the third head 121c and the exhaust passage 121d are shared. However, the two adjacent head groups 121 may not share them in the above region but may respectively include the third head 121c and the exhaust passage 121d. The first head 121a and the second head 121b are arranged in sequence from the upstream side to the downstream side in the conveying direction of the metal foil. As described above, the first head 121a is a head for supplying a precursor, the second head 121b is a head for supplying an oxidant, and the third head 121c is a head for supplying a purging gas. It should be noted that the positions of the respective heads and the exhaust passage are changed according to film-forming conditions and the like. For example, in the case of forming a film while moving the head 120 along the conveying direction of the metal foil, in one head group, the first head 121a may be arranged on the upstream side of the second head 121b or may be arranged on the downstream side.

[0083] In the case of forming a dielectric layer, first, a strip-shaped metal foil 1 having a porous portion on its surface is provided on a conveying mechanism. Specifically, an unwinding roller 111 around which the metal foil 1 is wound is provided at a prescribed position. The metal foil 1 is unwound from the unwinding roller 111, and when passing through the film-forming region 120x, a dielectric layer is formed on one main surface 1a (the surface on the head 120 side) of the metal foil. It should be noted that the film-forming region 120x is a region below the head 120 (the region between the head 120 and the metal foil 1). The metal foil 1x (electrode foil) on which the dielectric layer is formed is wound around a winding roller 113. An electrode foil for an electrolytic capacitor is manufactured in this way.

[0084] In the state of conveying the metal foil 1, a dielectric layer is formed by atomic layer deposition (layer-forming step). In the film-forming region 120x where the dielectric layer is formed using the head 120, the layer-forming step is performed in a state where the metal foil 1 is supported by a support belt 130 from the side opposite to the head 120 with the metal foil 1 interposed therebetween. Specifically, the metal foil 1 is supported from below by the support belt 130. The head 120 is arranged above the metal foil 1.

[0085] The support belt 130 is an endless belt and rotates in the direction of arrow B by rotating rollers 131 arranged at both ends. That is, with respect to the contact portion of the support belt 130 that contacts the metal foil 1 in the film-forming region 120x, when forming the dielectric layer, in the film-forming region 120x, it moves in the same direction as the moving direction of the metal foil 1 in a state of supporting the metal foil 1. It should be noted that rollers (rollers other than the roller 131) for supporting the support belt 130 may be arranged inside the support belt 130.

[0086] The plan view of observing the metal foil 1 and the support belt 130 in the film forming area 120x from the side of the head 120 is schematically shown in Figure 3 . In Figure 3 , the width direction WD and the length direction LD of the metal foil 1 are shown. The width of the support belt 130 is wider than the width of the metal foil 1, and in the film forming area 120x, the entire lower surface of the metal foil 1 is supported.

[0087] In the case where the dielectric layer is also formed on the other surface of the metal foil 1x, the wound metal foil 1x is conveyed to the film forming area 120x with the other main surface 1b of the metal foil 1x facing the head 120 side. In the film forming area 120x, the dielectric layer can be formed on the main surface 1b.

[0088] As described above, the manufacturing apparatus 100 may include a plurality of heads 120. A configuration of an example of the manufacturing apparatus 100 including two heads 120 is schematically shown in Figure 4 . Figure 4 The manufacturing apparatus 100 of

[0089] (Embodiment 2)

[0090] In Embodiment 2, a method of forming a dielectric layer on both surfaces of the metal foil 1 conveyed from the unwinding roller 111 and winding the metal foil 1y (electrode foil) having the dielectric layer formed on both surfaces with the winding roller 113 will be described.

[0091] A configuration of an example of the manufacturing apparatus used in Embodiment 2 is schematically shown in Figure 5 . Figure 5 The manufacturing apparatus 100a of Figure 1 and Figure 4 shown is different only in that the metal foil 1x is reversed to form the dielectric layer, so repeated descriptions may be omitted.

[0092] The manufacturing apparatus 100a includes a conveying mechanism 110, two heads (the first head and the second head) 120, and two support belts 130. The manufacturing apparatus 100a has two film forming areas 120x. The conveying mechanism includes an unwinding roller 111, a position adjusting roller 112, a winding roller 113, and a reversing roller 114. The reversing roller 114 is a roller for reversing the lower surface and the upper surface of the metal foil.

[0093] In the formation of the dielectric layer, first, as shown in Figure 1As described above, the unwinding roller 111 around which the strip-shaped metal foil 1 having a porous portion on the surface is wound is disposed at a predetermined position. Next, the metal foil 1 is unwound from the unwinding roller 111. In the first film-forming region 120x where the metal foil 1 first passes, a dielectric layer is formed on one surface (upper surface) of the metal foil 1. Next, the metal foil 1x having the dielectric layer formed thereon is reversed by the reversing roller 114. As a result, the surface on which the dielectric layer is not formed becomes the upper surface of the metal foil 1x. In the second film-forming region 120x where the metal foil 1x next passes, a dielectric layer is formed on the other surface (upper surface) of the metal foil 1. In this way, the metal foil 1y having dielectric layers formed on both surfaces is obtained. The metal foil 1y is wound by the winding roller 113. The electrode foil for an electrolytic capacitor is manufactured in this way. It should be noted that the manufacturing apparatus 100a may include a plurality of heads 120 for forming a dielectric layer on one surface of the metal foil 1, or may include a plurality of heads 120 for forming a dielectric layer on the other surface of the metal foil 1.

[0094] (Supplementary Note)

[0095] Through the above description, the following technology is disclosed.

[0096] (Technology 1)

[0097] A manufacturing apparatus for an electrode foil for an electrolytic capacitor, comprising:

[0098] A conveying mechanism that conveys a strip-shaped metal foil having a porous portion on the surface;

[0099] A head that supplies and removes a source gas to form a dielectric layer on the porous portion by atomic layer deposition; and

[0100] A support belt that supports the metal foil from the side opposite to the head across the metal foil in a film-forming region where the dielectric layer is formed by the head,

[0101] The dielectric layer is formed in a state where the metal foil is being conveyed,

[0102] A contact portion of the support belt that contacts the metal foil in the film-forming region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film-forming region.

[0103] (Technology 2)

[0104] According to the manufacturing apparatus described in Technology 1, wherein a ratio Vm / Vb of a moving speed Vm of the metal foil in the film-forming region to a moving speed Vb of the contact portion in the film-forming region is in a range of 0.9 to 1.1.

[0105] (Technology 3)

[0106] According to the manufacturing apparatus described in Technology 1 or 2, it further includes a heating device for heating the above-mentioned support belt.

[0107] (Technology 4)

[0108] According to the manufacturing apparatus described in any one of Technologies 1 to 3, it further includes:

[0109] A chamber that surrounds the above-mentioned head, the above-mentioned metal foil passing through the above-mentioned film-forming region, and the above-mentioned support belt passing through the above-mentioned film-forming region; and

[0110] A heating device for heating the interior of the above-mentioned chamber.

[0111] (Technology 5)

[0112] According to the manufacturing apparatus described in any one of Technologies 1 to 4, it further includes an adsorption mechanism for adsorbing the above-mentioned metal foil to the above-mentioned support belt in the above-mentioned film-forming region.

[0113] (Technology 6)

[0114] According to the manufacturing apparatus described in any one of Technologies 1 to 5, wherein the above-mentioned porous portion includes a first porous portion disposed on one main surface of the above-mentioned metal foil and a second porous portion disposed on the other main surface of the above-mentioned metal foil,

[0115] The above-mentioned head includes a first head for forming the above-mentioned dielectric layer on the above-mentioned first porous portion and a second head for forming the above-mentioned dielectric layer on the above-mentioned second porous portion,

[0116] The above-mentioned film-forming region includes a first film-forming region and a second film-forming region,

[0117] The above-mentioned support belt includes a first support belt for supporting the above-mentioned metal foil in the above-mentioned first film-forming region where the above-mentioned dielectric layer is formed using the above-mentioned first head and a second support belt for supporting the above-mentioned metal foil in the above-mentioned second film-forming region where the above-mentioned dielectric layer is formed using the above-mentioned second head.

[0118] (Technology 7)

[0119] A method for manufacturing an electrode foil for an electrolytic capacitor, which includes:

[0120] A preparation step of disposing a strip-shaped metal foil having a porous portion on its surface on a conveying mechanism; and

[0121] A layer formation step of forming a dielectric layer on the above-mentioned porous portion by atomic layer deposition while conveying the above-mentioned metal foil.

[0122] The formation of the dielectric layer is carried out by supplying and removing a source gas to form a head for forming the dielectric layer.

[0123] The above-described layer formation step is carried out in a state where a support belt supports the metal foil from the side opposite to the head across the metal foil in a film formation region where the dielectric layer is formed using the head, and the support belt and the head sandwich the metal foil.

[0124] In the above-described layer formation step, a contact portion of the support belt that contacts the metal foil in the film formation region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film formation region.

[0125] (Technology 8)

[0126] According to the manufacturing method described in Technology 7, wherein, in the above-described layer formation step, the ratio Vm / Vb of the moving speed Vm of the metal foil in the film formation region to the moving speed Vb of the contact portion in the film formation region is in the range of 0.9 to 1.1.

[0127] (Technology 9)

[0128] According to the manufacturing method described in Technology 7 or 8, wherein, in the above-described layer formation step, the support belt is heated.

[0129] (Technology 10)

[0130] According to the manufacturing method described in any one of Technologies 7 to 9, wherein the head, the metal foil passing through the film formation region, and the support belt passing through the film formation region are surrounded by a chamber.

[0131] In the above-described layer formation step, the inside of the chamber is heated.

[0132] (Technology 11)

[0133] According to the manufacturing method described in any one of Technologies 7 to 10, wherein, in the film formation region, the layer formation step is carried out in a state where the metal foil is adsorbed to the support belt.

[0134] (Technology 12)

[0135] According to the manufacturing method described in any one of Technologies 7 to 11, wherein the porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil.

[0136] The head includes a first head for forming the dielectric layer on the first porous portion and a second head for forming the dielectric layer on the second porous portion.

[0137] The above-mentioned film-forming region includes a first film-forming region and a second film-forming region.

[0138] The above-mentioned support belt includes a first support belt that supports the above-mentioned metal foil in the above-mentioned first film-forming region where the above-mentioned dielectric layer is formed using the above-mentioned first head, and a second support belt that supports the above-mentioned metal foil in the above-mentioned second film-forming region where the above-mentioned dielectric layer is formed using the above-mentioned second head.

[0139] Industrial applicability

[0140] The present disclosure can be used in a manufacturing apparatus and a manufacturing method for an electrode foil for an electrolytic capacitor.

[0141] Explanation of reference numerals

[0142] 1: Metal foil

[0143] 1x, 1y: Metal foil (electrode foil)

[0144] 100, 100a: Manufacturing apparatus

[0145] 110: Conveying mechanism

[0146] 120: Head

[0147] 120x: Film-forming region

[0148] 121a: First head

[0149] 121c: Second head

[0150] 130: Support belt

Claims

1. A manufacturing apparatus for an electrode foil for an electrolytic capacitor, comprising: A conveying mechanism that conveys a strip-shaped metal foil having a porous portion on its surface; A head that supplies and removes a source gas to form a dielectric layer on the porous portion by atomic layer deposition; And A support belt that supports the metal foil from the side opposite to the head across the metal foil in a film-forming region where the dielectric layer is formed by the head, The dielectric layer is formed in a state where the metal foil is being conveyed, A contact portion of the support belt that contacts the metal foil in the film-forming region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film-forming region.

2. The manufacturing apparatus according to claim 1, wherein, The ratio Vm / Vb of the moving speed Vm of the metal foil in the film-forming region to the moving speed Vb of the contact portion in the film-forming region is in the range of 0.9 to 1.

1.

3. The manufacturing apparatus according to claim 1 or 2, further comprising a heating device for heating the support belt.

4. The manufacturing apparatus according to claim 1 or 2, further comprising: A chamber that surrounds the head, the metal foil passing through the film-forming region, and the support belt passing through the film-forming region; And A heating device for heating the inside of the chamber.

5. The manufacturing apparatus according to claim 1 or 2, further comprising an adsorption mechanism for adsorbing the metal foil to the support belt in the film-forming region.

6. The manufacturing apparatus according to claim 1 or 2, wherein, The porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil, The head includes a first head that forms the dielectric layer on the first porous portion and a second head that forms the dielectric layer on the second porous portion, The film-forming region includes a first film-forming region and a second film-forming region, The support belt includes a first support belt that supports the metal foil in the first film-forming region where the dielectric layer is formed by the first head and a second support belt that supports the metal foil in the second film-forming region where the dielectric layer is formed by the second head.

7. A manufacturing method for an electrode foil for an electrolytic capacitor, comprising: A preparation step of disposing a strip-shaped metal foil having a porous portion on its surface on a conveying mechanism; And A layer formation step of forming a dielectric layer on the porous portion by atomic layer deposition in a state where the metal foil is being conveyed, The formation of the dielectric layer is performed using a head that supplies and removes a source gas to form the dielectric layer, The layer formation step is performed in a state where the metal foil is supported from the side opposite to the head across the metal foil by a support belt in a film-forming region where the dielectric layer is formed by the head, In the layer formation step, a contact portion of the support belt that contacts the metal foil in the film-forming region moves in the same direction as the moving direction of the metal foil in a state of supporting the moving metal foil in the film-forming region.

8. The manufacturing method according to claim 7, wherein, In the layer formation process, the ratio Vm / Vb of the moving speed Vm of the metal foil in the film formation region to the moving speed Vb of the contact portion in the film formation region is in the range of 0.9 to 1.

1.

9. The manufacturing method according to claim 7 or 8, wherein In the layer formation process, the support belt is heated.

10. The manufacturing method according to claim 7 or 8, wherein The head, the metal foil passing through the film formation region, and the support belt passing through the film formation region are surrounded by a chamber. In the layer formation process, the inside of the chamber is heated.

11. The manufacturing method according to claim 7 or 8, wherein, In the film formation region, the layer formation process is performed in a state where the metal foil is adsorbed to the support belt.

12. The manufacturing method according to claim 7 or 8, wherein The porous portion includes a first porous portion disposed on one main surface of the metal foil and a second porous portion disposed on the other main surface of the metal foil. The head includes a first head that forms the dielectric layer on the first porous portion and a second head that forms the dielectric layer on the second porous portion. The film formation region includes a first film formation region and a second film formation region. The support belt includes a first support belt that supports the metal foil in the first film formation region where the dielectric layer is formed by the first head, and a second support belt that supports the metal foil in the second film formation region where the dielectric layer is formed by the second head.

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