Anodizing apparatus and anodizing method using the same

Abstract

This invention provides an anodizing apparatus capable of efficiently forming an anodic oxide film on a substrate surface using an electrolyte membrane, and an anodizing method using the apparatus. The anodizing apparatus 1 is a device for anodizing the surface Ba of a substrate B by applying a voltage between a cathode 11 and a substrate B. The anodizing apparatus 1 includes: a housing 15 covering an opening 15d with an electrolyte membrane 13; a cathode 11 disposed inside the housing 15; a power supply 14 for applying a voltage between the cathode 11 and the substrate B; and a mounting stage 40 for placing the substrate B. The electrolyte membrane 13 has a contact area 13a that contacts the substrate B and a peripheral area 13b that faces the mounting stage 40 in a manner surrounding the contact area 13a. The surface 40a of the mounting stage 40 facing the peripheral area 13b is made of an insulating material.

Description

Technical Field

[0001] This invention relates to an anodizing apparatus and an anodizing method using the anodizing apparatus. Background Technology

[0002] Film-forming apparatuses for forming metal films on substrates have been known for a long time. These apparatuses include a container holding an electroplating solution. The electroplating solution and an anode (electrode) are housed inside the container. An opening is formed in the container opposite the substrate. The opening is covered by an electrolyte membrane. Thus, the electroplating solution is sealed inside the container. During film formation, first, the electrolyte membrane is brought into contact with the substrate. Then, a voltage is applied between the anode and the substrate. This reduces the metal ions contained within the electrolyte membrane. As a result, a metal film is formed on the surface of the substrate.

[0003] Prior art document: Japanese Patent No. 6056987 Summary of the Invention

[0004] The problem that the invention aims to solve

[0005] In addition, techniques for anodizing substrates are generally known. For example, when performing anodizing using the film-forming apparatus shown in Patent Document 1, it is feasible to simply use the electrode housed in the housing as the cathode and the substrate as the anode.

[0006] However, unlike the formation of metal films, in the case of anodizing, the treated surface of the substrate is oxidized to form an oxide film, thus increasing the surface resistance. Therefore, the voltage applied between the electrodes must be higher than that used for metal film formation. During anodizing, since the electrolyte membrane in contact with the electrolyte contains moisture, it is assumed that current will flow through the peripheral region of the electrolyte membrane, which is not in contact with the treated surface of the substrate. As a result, it may be difficult to effectively form an anodic oxide film on the treated surface of the substrate.

[0007] The present invention has been made in view of this, and its object is to provide an anodizing apparatus and an anodizing method thereof capable of efficiently forming an anodic oxide film on the treated surface of a substrate using an electrolyte membrane.

[0008] Means for solving technical problems

[0009] In view of the aforementioned technical problems, the anodizing apparatus of the present invention is a processing apparatus that anodizes the surface of a substrate by applying a voltage between a cathode and a substrate. The processing apparatus includes: a housing having an opening at a position opposite to the substrate, the opening being covered by an electrolyte membrane when containing an electrolyte solution; a cathode disposed inside the housing at a position opposite to the electrolyte membrane; a power source applying a voltage between the cathode and the substrate; and a stage disposed across the electrolyte membrane at a position opposite to the cathode for placing the substrate. The electrolyte membrane has a contact area that contacts the surface of the substrate being processed and a peripheral area that surrounds the contact area and faces the stage. The surface of the stage facing the peripheral area is made of an insulating material.

[0010] In some technical solutions, the mounting stage may be made of the insulating material, and a conductive member may be built into the mounting stage, which makes the contact surface of the substrate that contacts the mounting stage conductive to the positive terminal of the power supply. As another technical solution, the mounting stage may have a receiving recess for accommodating the substrate when it is mounted, and a suction flow path that is continuous with the space formed between the side wall of the receiving recess and the side surface of the substrate, for attracting fluid within the space.

[0011] In another technical solution, the platform may also include: a platform body made of conductive material and connected to the positive terminal of the power supply; and a frame mounted on the platform body, facing the surrounding area, and made of insulating material.

[0012] Furthermore, in the anodizing process using these anodizing apparatuses, firstly, after drying the surface of the substrate to be processed, the substrate is placed on the mounting stage. Next, the contact area of ​​the electrolyte membrane is brought into contact with the surface of the substrate to be processed, and a voltage from the power supply is applied between the substrate and the cathode, thereby forming an anodized film on the surface layer of the substrate containing the processed surface.

[0013] Invention Effects

[0014] According to the present invention, an anodic oxide film can be efficiently formed on the treated surface of a substrate using an electrolyte membrane. Attached Figure Description

[0015] Figure 1 (A) is a schematic diagram of the processing apparatus for performing the anodizing process according to the first embodiment. Figure 1 (B) indicates that the stage and the substrate are relative to each other. Figure 1(A) is a schematic top view of the positional relationship of the electrolyte membranes in the processing device.

[0016] Figure 2 (A) is used to illustrate the use of Figure 1 A schematic diagram of the processing method of the processing apparatus shown in (A). Figure 2 (B) is Figure 2 Enlarged view of part X of (A). Figure 2 (C) is a schematic enlarged perspective view of the substrate after anodizing.

[0017] Figure 3 (A) is a schematic diagram of the processing apparatus for performing the anodizing process according to the second embodiment. Figure 3 (B) indicates that the electrolyte membrane, substrate, and platform body are relative to each other. Figure 3 A schematic top view showing the positional relationship of the frames shown in (A).

[0018] Figure 4 (A) is used to illustrate the use of Figure 3 Figure 4(A) is a schematic diagram of the processing method of the processing apparatus. Figure 4(B) is... Figure 4 Enlarged view of part X of (A).

[0019] Figure 5 (A) was measured in the examples using Figure 1 The result is obtained by considering the relationship between the application time and the applied voltage of the processing device shown in (A) which processes with a constant current. Figure 5 (B) represents the result showing the relationship between the application time and the film thickness in the embodiment where the process is performed with a constant current.

[0020] Figure 6 (A) is a photograph of the processed surface of the substrate of the embodiment. Figure 6 (B) is observed using an electron microscope. Figure 6 The photograph obtained from the treated surface of the substrate (A). Figure 6 (C) is a cross-sectional photograph of the substrate of the embodiment. Figure 6 (D) is observed using an electron microscope. Figure 6 The photograph obtained from the cross section of the substrate (C). Detailed Implementation

[0021] First Implementation Method

[0022] The following is for reference Figure 1 and Figure 2The anodizing apparatus (anodizing apparatus) 1 of the first embodiment will be described. In this embodiment, the apparatus 1 includes a cathode 11, an electrolyte membrane 13, and a power supply 14 for applying voltage between the cathode 11 and the substrate B.

[0023] like Figure 1 (A) and Figure 2 As shown in (A), the processing apparatus 1 further includes a housing 15 for housing the cathode 11 and the electrolyte L, and a stage 40 for mounting the substrate B. The processing apparatus 1 also includes a direct-acting actuator 70 for raising and lowering the housing 15. The direct-acting actuator 70 raises and lowers the housing 15 by directly moving a rod 72, so that the electrolyte membrane 13 can freely contact and separate from the substrate B. The direct-acting actuator 70 has a rod 72 that moves directly relative to the main body 71, and the housing 15 is fixed at the front end of the rod 72.

[0024] The cathode 11 is an insoluble cathode that does not dissolve in the electrolyte L during the anodic oxidation process. Examples of cathodes 11 include gold, platinum, iridium oxide, or carbon. The substrate B is not particularly limited as long as an oxide film can be formed on the treated surface Ba by the anodic oxidation process.

[0025] In this embodiment, the substrate B is, for example, a plate with a rectangular surface Ba. The substrate B has a contact surface Bb that contacts the stage 40. The contact surface Bb is the back side of the substrate B, located opposite the surface Ba. Side surfaces Bs are formed between the surface Ba and the contact surface Bb. Examples of substrate B include metallic materials such as aluminum, titanium, or magnesium. The substrate B can also be a metallic substrate in which these metallic materials are formed into a film on a conductive material. As described later, when at least the surface Ba is made of aluminum, the anodizing process is an anodized aluminum film treatment. The anodized film formed on the surface Ba of the substrate B is an anodized aluminum film.

[0026] The cathode 11 is electrically connected to the negative terminal of the power supply 14. The negative terminal of the power supply 14 is electrically connected to the substrate B via a conductive component 30 built into the mounting stage 40. The electrolyte L is an acidic aqueous solution. Examples of electrolyte L include aqueous solutions of sulfuric acid, oxalic acid, or phosphoric acid.

[0027] Electrolyte membrane 13 is a membrane that can be impregnated (containing) electrolyte L by contacting it. Electrolyte membrane 13 is a flexible membrane. When a voltage is applied through power source 14, the material of electrolyte membrane 13 is not particularly limited, as long as electrons or hydrogen ions reacting on the treated surface Ba of substrate B can move towards cathode 11. Examples of materials for electrolyte membrane 13 include fluorinated resins with ion exchange functions, such as Nafion (registered trademark) manufactured by DuPont. Figure 1As shown in (B), the electrolyte membrane 13 has a contact area 13a that contacts the processed surface Ba of the substrate B and a peripheral area 13b that faces the stage 40 described later in a manner that surrounds the contact area 13a.

[0028] like Figure 1 As shown in (A), a housing space 15a for containing electrolyte L is formed in the housing 15. A cathode 11 is disposed in the housing space 15a of the housing 15. An opening 15d is formed on the substrate B side of the housing space 15a. The opening 15d of the housing 15 is covered by an electrolyte membrane 13, which is detachably fixed to the housing 15 by a frame 17. Thus, when electrolyte L is contained in the housing space 15a, the opening 15d of the housing 15 is sealed by the electrolyte membrane 13. Furthermore, the cathode 11 is disposed inside the housing 15 at a position opposite to the electrolyte membrane 13.

[0029] The housing 15 has a supply port 15b for supplying electrolyte L to the housing space 15a and a discharge port 15c for discharging electrolyte L from the housing space 15a. The supply port 15b and the discharge port 15c are formed across the housing space 15a. The supply port 15b is fluidly connected to the supply pipe 51. The discharge port 15c is fluidly connected to the discharge pipe 52.

[0030] The processing apparatus 1 includes a tank 55 containing electrolyte L and a circulation mechanism 50 for circulating the electrolyte L between the tank 55 and the housing 15. The circulation mechanism 50 includes a supply pipe 51, a discharge pipe 52, a circulation pump 53, and a cooler 54. The supply pipe 51 connects the tank 55 to the housing 15, and the cooler 54 and the circulation pump 53 are installed on the supply pipe 51. The discharge pipe 52 connects the tank 55 to the housing 15. Furthermore, the cooler 54 is a device for cooling the electrolyte L. The cooler 54 can be installed on either the tank 55 or the discharge pipe 52, as long as the electrolyte L can be cooled by the cooler 54.

[0031] like Figure 2 As shown in (A), in this embodiment, the electrolyte L is drawn from the tank 55 into the supply pipe 51 by driving the circulation pump 53, and is then pumped from the supply port 15b into the receiving space 15a. The electrolyte L in the receiving space 15a is returned to the tank 55 via the discharge port 15c. During the anodizing process, heat is generated on the surface of the substrate B, but by circulating the electrolyte L cooled by the cooler 54, the electrolyte L can function as a refrigerant for cooling the substrate B and the processing apparatus 1.

[0032] The mounting stage 40 is used to mount the substrate B. The mounting stage 40 is positioned opposite the cathode 11, separated by the electrolyte membrane 13. The mounting stage 40 is made of an insulating material. Examples of materials for the mounting stage 40 include resin or ceramic, as long as the material has electrical insulating properties; there are no particular limitations.

[0033] Therefore, in this embodiment, as Figure 1 (B) and Figure 2 As shown in (B), the surface 40a of the mounting stage 40 facing the peripheral region 13b of the electrolyte membrane 13 is formed of an insulating material. The mounting stage 40 has a receiving recess 40b for receiving the substrate B when the substrate B is mounted. A receiving space S for receiving the substrate B is formed in the receiving recess 40b. The receiving recess 40b has a bottom wall surface 43 that abuts against the contact surface Bb of the substrate B and a side wall surface 41 that faces the side surface Bs of the substrate B.

[0034] The mounting stage 40 contains a conductive member 30 that enables the contact surface Bb of the substrate B to conduct electricity with the positive terminal of the power supply 14. Examples of materials for the conductive member 30 include stainless steel or titanium alloy; there are no particular limitations on the material as long as it does not dissolve in the electrolyte L and can conduct electricity between the substrate B and the positive terminal of the power supply 14.

[0035] The conductive component 30 has a first conductive portion 31 and a second conductive portion 32. The first conductive portion 31 is connected to the positive terminal of the power supply 14 and is a rod-shaped portion inserted into the interior of the mounting stage 40 from the side. The second conductive portion 32 is a pin-shaped portion inserted into the interior of the mounting stage 40 from the bottom wall surface 43 of the receiving recess 40b and connected to the first conductive portion 31. In this embodiment, there are two second conductive portions 32, but their number is not particularly limited.

[0036] The end face 33 of the second conductive portion 32 becomes part of the bottom wall surface 43 of the receiving recess 40b. The end face 33 of the second conductive portion 32 and the bottom wall surface 43 of the receiving recess 40b are formed in the same plane. Thus, when the substrate B is received in the receiving recess 40b, the contact surface Bb of the substrate B contacts the bottom wall surface 43 of the receiving recess 40b. As a result, the electrolyte L is less likely to enter between the contact surface Bb of the substrate B and the bottom wall surface 43 of the receiving recess 40b, thereby stabilizing the current flow between the substrate B and the cathode 11 and stabilizing the anodizing treatment of the processed surface Ba of the substrate B.

[0037] like Figure 2 As shown in (B), with the substrate B housed in the receiving recess 40b of the mounting stage 40, a space C, which is a small gap, is formed between the side wall surface 41 of the receiving recess 40b and the side surface Bs of the substrate B. A suction flow path 61, continuous with this space C, is provided on the mounting stage 40 to draw fluid (e.g., electrolyte L or air) within the space C. The suction flow path 61 is connected to a suction pump 63 via a suction pipe 62.

[0038] In this embodiment, such as Figure 1As shown in (B), multiple suction ports 61a of the suction flow path 61 are provided along the edge of the bottom wall surface 43 of the receiving recess 40b. Therefore, even if the electrolyte L enters between the side surface Bs of the substrate B and the side wall surface 41 of the receiving recess 40b, it can be discharged. This allows for a stable current flow through the processed surface Ba of the substrate B. Furthermore, the substrate B can be adsorbed onto the bottom wall surface 43 of the mounting stage 40. As a result, the anodizing treatment of the processed surface Ba of the substrate B can be performed stably.

[0039] The following describes an anodizing process using an anodizing apparatus. First, after pretreatment such as cleaning the substrate B, the surface Ba of the substrate B is dried. Specifically, this drying is performed by blowing air. This drying removes moisture from the surface Ba of the substrate B. As a result, during the anodizing process described later, current flow outside the surface Ba due to moisture flow can be prevented. Then, for example, the periphery of the substrate B, including the side surfaces Bs, can be covered with a resin tape or a thin film of rubber.

[0040] Next, substrate B is placed on the mounting stage 40 by accommodating it in the receiving recess 40b of the mounting stage 40. Then, the electrolyte membrane 13 is brought into contact with substrate B. Specifically, the direct-acting actuator 70 is driven to move the receiving body 15, fixed to the front end of the rod 72, toward the mounting stage 40 until the electrolyte membrane 13 abuts against substrate B (see, for example, reference...). Figure 2 (A)). Thus, the contact area 13a of the electrolyte membrane 13 can be brought into contact with the processed surface Ba of the substrate B. Furthermore, the peripheral area 13b of the electrolyte membrane 13 can be brought into contact with the surface 40a of the mounting stage 40 made of insulating material.

[0041] Next, the electrolyte L is contained in the containment body 15. Specifically, by driving the circulation pump 53, the electrolyte L is drawn from the tank 55 into the supply pipe 51 and pressurized from the supply port 15b into the containment space 15a. The electrolyte L in the containment space 15a returns to the tank 55 via the discharge port 15c. In this way, the electrolyte L circulates in the containment body 15. Furthermore, the electrolyte L in the containment body 15 is only subjected to the circulation pressure of the circulation pump 53. Therefore, the substrate B is only subjected to the circulation pressure of the electrolyte L via the electrolyte membrane 13, thus suppressing excessive leakage of the electrolyte L from the electrolyte membrane 13 into the substrate B.

[0042] In this state, the voltage of the power supply 14 is applied between the substrate B and the cathode 11. Simultaneously, the suction pump 63 is activated. Thus, as... Figure 2As shown in (C), an anodic oxide film Bf is formed on the surface layer Bc of the substrate B, which includes the treated surface Ba. Multiple fine pores Bh are formed in the anodic oxide film Bf. Then, electrolyte L is discharged from the receiving space 15a of the housing 15, and the direct-acting actuator 70 is driven to separate the electrolyte membrane 13 from the substrate B, thus removing the substrate B from the stage 40.

[0043] The anodic oxide film Bf formed on the substrate B has a high resistance relative to the base material Bm of the substrate B, making it difficult for the current from the power supply 14 to flow between the processed surface Ba of the substrate B and the cathode 11. Therefore, the current tends to flow to the mounting stage 40 via the peripheral region 13b of the electrolyte membrane 13. However, in this embodiment, the mounting stage 40 is made of an insulating material, and therefore the surface 40a of the mounting stage 40 opposite to the peripheral region 13b is also made of an insulating material. This prevents the current from flowing to the mounting stage 40 via the peripheral region 13b of the electrolyte membrane 13, allowing the current from the power supply 14 to flow efficiently between the processed surface Ba of the substrate B and the cathode 11.

[0044] As a result, an anodic oxide film Bf can be efficiently formed on the treated surface Ba of the substrate B using an electrolyte membrane. Furthermore, by operating the suction pump 63, the water contained in the electrolyte L that seeps out from the electrolyte membrane 13 can be discharged via the suction flow path 61. As a result, the current from the power supply 14 can flow more efficiently between the treated surface Ba of the substrate B and the cathode 11.

[0045] Second Implementation Method

[0046] The following is for reference Figure 3 and Figure 4 The anodizing apparatus (anodizing treatment apparatus) 1 of the second embodiment will be described. The difference between this embodiment and the first embodiment lies in the structure of the mounting stage 40. Therefore, the same components and mechanisms as in the first embodiment are used. Figure 3 as well as Figure 4 The same symbols are marked in the text, and their detailed explanations are omitted.

[0047] like Figure 3 As shown in (A), the stage 40 includes a stage body 45 that is connected to the positive terminal of the power supply 14 and a frame 47 mounted on the stage body 45. The stage body 45 is made of a conductive material such as stainless steel. Therefore, unlike the stage in the first embodiment, no conductive member 30 is provided in the stage body 45. A receiving recess 40b for receiving the substrate B is formed in the stage body 45, similar to that in the stage in the first embodiment. Furthermore, as... Figure 4 (A) and Figure 4As shown in (B), a suction flow path 61 is provided on the main body 45. This suction flow path 61 is continuous with the space C between the side wall surface 41 formed in the receiving recess 40b and the side surface Bs of the substrate B, and is used to suction fluid in the space C. The suction flow path 61 is connected to the suction pump 63 via a suction pipe 62.

[0048] The frame 47 is opposite to the peripheral region 13b of the electrolyte membrane 13. The frame 47 is made of an insulating material such as resin or ceramic. Figure 3 As shown in (A), an opening 47a is formed on the frame 47. With the substrate B housed in the receiving recess 40b of the stage body 45, the processed surface Ba of the substrate B is exposed through the opening 47a of the frame 47. Therefore, the space region surrounded by the opening 47a of the frame 47 faces the contact region 13a of the electrolyte membrane 13, and the frame 47 faces the peripheral region 13b of the electrolyte membrane 13. The surface 40a of the stage 40 facing the peripheral region 13b of the electrolyte membrane 13 is made of an insulating material.

[0049] like Figure 3 As shown in (B), this embodiment is similar to the first embodiment. First, after drying the treated surface Ba of the substrate B, the substrate B is placed on the mounting stage 40. At this time, the frame 47 can also be installed after the substrate B is housed in the receiving recess 40b of the stage body 45. Next, the direct-acting actuator 70 is driven to bring the contact area 13a of the electrolyte membrane 13 into contact with the treated surface Ba of the substrate B. Then, the circulation pump 53 is driven to supply electrolyte L to the housing 15 and circulate the electrolyte L. In this state, the voltage of the power supply 14 is applied between the substrate B and the cathode 11. At the same time, the suction pump 63 is operated. The result is the same as Figure 2 Similarly, as shown in (C), in this embodiment where an anodized film Bf can be formed on the surface layer Bc of the substrate B, which includes the processed surface Ba, the surface 40a that contacts the peripheral region 13b of the electrolyte membrane 13 during the anodizing process is made of an insulating material, thus the same effect as in the first embodiment can be expected.

[0050] Example

[0051] use Figure 1The processing apparatus shown in (A) performs anodizing treatment on the surface Ba of substrate B. Twenty sheets of pure aluminum (A1050) were prepared as substrate B. The surface Ba of substrate B is 50mm × 50mm. The thickness of substrate B is 0.5mm. Next, a 10% by mass aqueous solution of sulfuric acid was prepared as the electrolyte. A DC power supply (model ZX-400LA manufactured by Takasago) was used as the power supply. A mesh electrode coated with iridium oxide was prepared as the cathode. The mesh diameter of the mesh electrode is 50mm. 2L of electrolyte was cooled to below 10°C with ice. Then, while circulating the electrolyte, a voltage was applied between the substrate and the cathode under constant current conditions. The current condition was a current density of 1.0A / dm³. 2 and 3A / dm 2 For each current condition, an anodic oxide film is formed on 10 substrates.

[0052] Figure 5 (A) was measured in the embodiment at a constant current (current density 1 A / dm³). 2 The result is obtained by processing the relationship between the application time and the applied voltage. For example... Figure 5 As shown in (A), the voltage value increases at the beginning of voltage application due to the natural oxide film formed on the treated surface of the substrate. However, as the application time progresses, the applied voltage stabilizes at a roughly constant value (approximately 20V). Furthermore, when forming a metal film using the same constant current with the film-forming apparatus shown in the prior art, the applied voltage is approximately 5V. Therefore, the applied voltage during anodizing is higher than the applied voltage during metal film formation. This is believed to be because, during anodizing, an oxide film forms on the treated surface of the substrate.

[0053] Figure 5 (B) indicates that in the embodiment, a constant current (current density 1 A / dm) is used. 2 and 3A / dm 2 The results show the relationship between the application time and the film thickness during the treatment. It should be noted that... Figure 5 In (B), the results of forming an anodic oxide film on a substrate in a bath containing electrolyte are shown as a reference example using solid lines. From these results, a current density of 1 A / dm³ is achieved. 2 The results are largely the same as those of the reference example. Furthermore, it can be seen that if the applied voltage is the same, the component with the higher current density can form an anodic oxide film to the specified thickness more quickly. This can be attributed to the fact that the surface of the stage facing the peripheral region of the electrolyte membrane is made of an insulating material, thus allowing current to flow efficiently between the cathode and the substrate.

[0054] Furthermore, observations were made at a current density of 3 A / dm². 2The treated surface and cross-section of the substrate subjected to anodizing under the specified conditions are shown in the figure. Figure 6 (A)~(D). Figure 6 (A) is a photograph of the processed surface of the substrate of the embodiment. Figure 6 (B) is observed using an electron microscope. Figure 6 A photograph of the treated surface of the substrate (A). Figure 6 (C) is a cross-sectional photograph of the substrate of the embodiment. Figure 6 (D) is observed using an electron microscope. Figure 6 (C) is a photograph of the cross-section of the substrate.

[0055] like Figure 6 As shown in (C), it can be seen that the surface layer of the substrate, including the treated surface, is an anodized aluminum film (anodized film). Furthermore, as... Figure 6 (B) and Figure 6 As shown in (D), fine pores characteristic of anodized films are formed on the treated surface of the substrate that has undergone anodizing treatment.

[0056] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described therein. Various design changes can be made without departing from the spirit of the present invention as set forth in the claims.

[0057] In the second embodiment, a frame made of insulating material is mounted on a platform body made of conductive material. However, for example, an insulating material such as resin may be coated on the surface of the platform body that is in contact with the peripheral area of ​​the electrolyte membrane.

[0058] Explanation of reference numerals in the attached figures

[0059] 1: Anodizing treatment apparatus (treatment device), 11: Cathode, 13: Electrolyte membrane, 13a: Contact area, 13b: Peripheral area, 14: Power supply, 15: Housing, 40: Stage, 40b: Receiving recess, 61: Suction flow path, 45: Stage body, 47: Frame, B: Substrate, Ba: Treatment surface, Bf: Anodized film, L: Electrolyte.

Claims

1. An anodizing apparatus, which anodizes the surface of a substrate by applying a voltage between a cathode and a substrate, characterized in that, The processing apparatus includes: A housing having an opening at a position opposite to the substrate, and the opening being covered by an electrolyte membrane when containing electrolyte. A cathode is disposed inside the containment at a position opposite to the electrolyte membrane; A power source that applies a voltage between the cathode and the substrate; as well as A stage, positioned opposite the cathode and separated by the electrolyte membrane, is used to hold the substrate. The electrolyte membrane has a contact area that contacts the processed surface of the substrate, and a peripheral area that faces the stage in a manner that surrounds the contact area. The surface of the platform that faces the surrounding area is made of an insulating material.

2. The anodizing apparatus according to claim 1, characterized in that, The mounting platform is made of the insulating material. The mounting stage contains a conductive component that enables the contact surface of the substrate that contacts the mounting stage to be connected to the positive terminal of the power supply.

3. The anodizing apparatus according to claim 2, characterized in that, The mounting stage has a receiving recess for accommodating the substrate when the substrate is mounted, and is provided with an attraction flow path that is continuous with the space formed between the side wall of the receiving recess and the side of the substrate for attracting fluid within the space.

4. The anodizing apparatus as described in claim 1, characterized in that, The mounting stage includes: The main body of the platform is made of conductive material and is connected to the positive terminal of the power supply; and The frame, which is mounted on the main body of the platform and faces the surrounding area, is made of the insulating material.

5. An anodizing treatment method, which is an anodizing treatment method using the anodizing treatment apparatus according to claim 1, characterized in that, After the treated surface of the substrate is dried, the substrate is placed on the mounting stage. The contact area of ​​the electrolyte membrane is brought into contact with the processed surface of the substrate, and the voltage of the power supply is applied between the substrate and the cathode, thereby forming an anodic oxide film on the surface layer of the substrate containing the processed surface.

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