Metal film deposition equipment

Abstract

To provide a deposition apparatus of a metallic film with a simpler configuration.SOLUTION: A deposition apparatus 1 comprises: an anode 11; a solid electrolyte membrane 13; a power supply unit 14; and an insulating container 15 for covering an aperture 15a opening toward the substrate side with the solid electrolyte membrane, for accommodating the anode at a position away from the solid electrolyte membrane so as to be slidable in the direction toward the solid electrolyte membrane, and for accommodating an electrolyte L between the solid electrolyte membrane and the anode. The deposition apparatus 1 also comprises a conductive cap 17 for covering the container from the anode side and an elastic body 18 arranged between the cap and the anode. In a state that the solid electrolyte membrane contacts the substrate, the end part 17a of the cap is assembled so as to be away from the substrate, and by pushing in the cap toward the anode side, the elastic body can be deformed in a compression manner until the edge face 17b of the cap contacts the substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a film forming apparatus for forming a metal film on a surface of a substrate. [Background technology]

[0002] Conventionally, a metal coating has been formed by depositing a metal on the surface of a substrate (for example, Patent Document 1). Patent Document 1 describes a film forming apparatus including a metal anode, a solid electrolyte membrane (hereinafter also referred to as electrolyte membrane) arranged on the surface of the anode, and a power supply unit that applies a voltage between the anode and the substrate, with the substrate being the cathode. In this film forming apparatus, a voltage is applied between the anode and the substrate by using the power supply unit while the electrolyte membrane, which is impregnated with a solution containing metal ions, is in contact with the substrate. As a result, the metal ions impregnated in the electrolyte membrane move to the substrate in contact with the electrolyte membrane and are reduced on the surface of the substrate. As a result, the metal is deposited on the surface of the substrate, and a metal coating is formed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-122377 A Summary of the Invention [Problem to be solved by the invention]

[0004] The positive and negative electrodes of the power supply unit are electrically connected to the substrate as the anode and cathode via conductors, respectively. In this manner, the film forming apparatus requires wiring to form a metal film, which may complicate the configuration of the film forming apparatus.

[0005] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a metal film forming apparatus having a simpler configuration. [Means for solving the problem]

[0006] In consideration of the above problems, a metal coating forming apparatus according to the present invention includes an anode, a solid electrolyte membrane disposed between the anode and a substrate, a power supply unit that applies a voltage between the anode and the substrate using the substrate as a cathode, and an insulating container that covers an opening on the substrate side with the solid electrolyte membrane, contains the anode at a position spaced from the solid electrolyte membrane so as to be slidable in a direction toward the solid electrolyte membrane, and contains an electrolytic solution containing metal ions between the solid electrolyte membrane and the anode, and applies a voltage between the anode and the substrate with the solid electrolyte membrane in contact with the substrate, thereby reducing the metal ions contained inside the solid electrolyte membrane. a metal film forming apparatus for forming a metal film derived from the metal ions on a surface of the substrate, the film forming apparatus comprising: a conductive cap covering the container from the anode side; and an elastic body arranged between the cap and the anode, the positive electrode of the power supply unit being connected to the anode and the negative electrode of the power supply unit being connected to the cap, an end of the cap being formed so as to be spaced apart from the substrate when the solid electrolyte membrane is in contact with the substrate, and the elastic body being compressively deformable by pressing the cap toward the anode side until the end face of the cap comes into contact with the substrate.

[0007] In the film forming apparatus according to the present invention, with the solid electrolyte membrane in contact with the substrate, the end of the cap is spaced from the substrate. In this state, when the cap is pressed toward the anode, the elastic body is compressed and deformed, and the anode is urged by the elastic body in a direction toward the solid electrolyte membrane. This causes the anode to slide within the container in a direction toward the solid electrolyte membrane. As a result, the liquid pressure of the electrolyte solution contained between the anode and the solid electrolyte membrane increases, allowing the solid electrolyte membrane to conform to the surface of the substrate.

[0008] When the cap is further pushed toward the anode, the end face of the cap comes into contact with the substrate. As a result, the substrate is electrically connected to the negative pole of the power supply through the cap, and a voltage is applied between the anode and the substrate. In this manner, in the above-mentioned film forming apparatus, the solid electrolyte film can be made to conform to the surface of the substrate by simply pushing the cap toward the anode, and the formation of the metal film can be started. Effect of the Invention

[0009] According to the present invention, the configuration of the metal film forming apparatus can be simplified. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a metal film forming apparatus according to an embodiment of the present invention, showing a state in which a cap is separated from a substrate. [Diagram 2] This shows the state where the cap is in contact with the substrate in the film forming apparatus of FIG. [Diagram 3] 2 is a flowchart illustrating a method for forming a metal film using the film forming apparatus of FIG. 1. [Figure 4] FIG. 11 is a schematic cross-sectional view of a metal film forming apparatus according to another embodiment of the present invention, showing a state in which the cap is separated from the substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a metal film forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0012] Fig. 1 is a schematic cross-sectional view of a metal coating deposition apparatus 1 according to an embodiment of the present invention, showing a state in which a cap 17 is separated from a substrate B. Fig. 2 shows a state in which the cap 17 is in contact with the substrate B in the deposition apparatus 1 of Fig. 1.

[0013] 1 and 2, the film forming apparatus 1 includes an anode 11, a solid electrolyte membrane (hereinafter also referred to as electrolyte membrane) 13 disposed between the anode 11 and a substrate B, a battery (power supply unit) 14 that applies a voltage between the anode 11 and the substrate B with the substrate B serving as a cathode, and an insulating container 15 that contains an electrolytic solution L containing metal ions. A positive electrode 14a of the battery 14 is connected to the anode 11 via an anode current conductor 19, which will be described later, and a negative electrode 14b of the battery 14 is connected to a cap 17, which will be described later.

[0014] As shown in Fig. 2, the film forming apparatus 1 is an apparatus that applies a voltage between the anode 11 and the substrate B in a state where the electrolyte membrane 13 is in contact with the substrate B, and reduces the metal ions contained inside the electrolyte membrane 13, thereby forming a metal coating derived from the metal ions on the surface B1 of the substrate B. In this embodiment, for convenience of explanation, the positional relationship of the components of the film forming apparatus 1 is specified on the premise that the electrolyte membrane 13 is disposed below the anode 11, and the substrate B is disposed further below that. However, as long as a metal coating (not shown) can be formed on the surface B1 of the substrate B, the positional relationship is not limited to this, and for example, the film forming apparatus 1 in Fig. 1 may be upside down.

[0015] The substrate B may be any material as long as it functions as a cathode (i.e., a surface having electrical conductivity). The substrate B has a surface B1 facing the electrolyte membrane 13. The material of the substrate B is not particularly limited as long as it functions as a cathode (i.e., a surface having electrical conductivity), and may be made of a metal material such as aluminum or iron, or may have a surface of a resin, ceramic, or the like coated with a metal layer such as copper, nickel, silver, or iron.

[0016] The anode 11 has a shape corresponding to the film-forming region of the substrate B. The film-forming region of the substrate B means a portion of the surface B1 of the substrate B facing the anode 11. The anode 11 is made of the same metal as the metal coating. The anode 11 may be non-porous (for example, non-porous) or porous. When a non-porous anode 11 is used, the metal coating formed on the substrate B is less susceptible to the surface condition of the anode 11. The anode 11 may be block-shaped or flat. The anode 11 is soluble in the electrolyte L, and dissolves when a voltage is applied using a battery 14. Examples of materials for the anode 11 include copper, nickel, and silver.

[0017] The film forming apparatus 1 includes an anode current conductor 19 disposed between the anode 11 and the battery 14. The anode current conductor 19 is disposed so as to be in direct contact with the anode 11, and electrically connects the anode 11 and the positive electrode 14a of the battery 14. The anode current conductor 19 may be in the shape of a block or a flat plate, and examples of the material thereof include titanium and stainless steel. The passive film formed on the surface of the anode current conductor 19 can suppress rust from occurring on the anode 11.

[0018] The electrolyte L is a liquid containing the metal of the metal film to be formed in an ionic state, and examples of the metal include copper, nickel, and silver. The electrolyte L is an aqueous solution in which these metals are dissolved (ionized) with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, and pyrophosphoric acid. For example, when the metal is copper, examples of the electrolyte L include an aqueous solution containing copper sulfate, copper pyrophosphate, and the like.

[0019] The electrolyte membrane 13 is a flexible membrane that can be impregnated (contained) with metal ions by contacting it with the electrolytic solution L. The electrolyte membrane 13 is not particularly limited as long as it can reduce metal ions in the substrate B and precipitate metal derived from the metal ions when a voltage is applied from the battery 14. Examples of the material of the electrolyte membrane 13 include fluorine-based resins such as Nafion (registered trademark) manufactured by DuPont, hydrocarbon-based resins, polyamic acid resins, and resins having an ion exchange function such as Selemion (CMV, CMD, CMF series) manufactured by Asahi Glass Co., Ltd.

[0020] The container 15 has a cylindrical shape and is made of an insulating material. The container 15 includes a lower opening (opening) 15a that opens toward the substrate B (i.e., downward) and an upper opening 15b that opens toward the opposite side of the substrate B (i.e., upward). The container 15 covers the lower opening 15a that opens toward the substrate B with the electrolyte membrane 13, and accommodates the anode 11 and the anode current conductor 19 at a position spaced apart from the electrolyte membrane 13. The anode 11 and the anode current conductor 19 are accommodated in the container 15 so as to be slidable in a direction toward the electrolyte membrane 13. The inner wall surface of the container 15, the anode 11, and the electrolyte membrane 13 form a storage space 15c, and the electrolyte solution L is accommodated in the storage space 15c. As shown in FIG. 1, the container 15 is structured so that the electrolyte solution L accommodated in the storage space 15c directly contacts the anode 11 and the electrolyte membrane 13. The container 15 is made of a material that is insoluble in the electrolyte L.

[0021] As shown in FIGS. 1 and 2, the film forming apparatus 1 further includes a cap 17, a spring (elastic body) 18, an attachment member 24, and an insulating cover 20.

[0022] The cap 17 has a bottomed cylindrical shape and is made of a conductive material. The cap 17 includes a substrate-side opening 17c that opens toward the substrate B, a blocking portion 17d that covers the container 15 from the anode 11 side on the opposite side of the substrate-side opening 17c, and a side wall portion 17e that extends from the blocking portion 17d toward the substrate B. The cap 17 has an internal space 17f defined by the inner wall surfaces of the blocking portion 17d and the side wall portion 17e. The cap 17 has an end surface 17b that faces the substrate B at an end portion 17a of the side wall portion 17e on the substrate B side. As shown in FIG. 1, the end portion 17a of the cap 17 is formed so as to be separated from the substrate B with the electrolyte membrane 13 in contact with the substrate B. The cap 17 accommodates the container 15, an elastic body 18 described later, and the battery 14 in the internal space 17f. The battery 14 is accommodated in the internal space 17f of the cap 17 such that the negative electrode 14b of the battery 14 is in contact with the closing portion 17d of the cap 17. The housing 15 is accommodated in the internal space 17f of the cap 17 such that the substrate side opening 17c of the housing 15 is located on the substrate B side.

[0023] The elastic body 18 is disposed between the cap 17 and the anode 11. Specifically, the elastic body 18 is disposed between the positive electrode 14a of the battery 14 and the anode current conductor 19. The elastic body 18 is, for example, a compression spring, and elastically supports the cap 17 from below via the battery 14. The elastic body 18 is freely compressively deformed by pressing the cap 17 toward the anode 11 until the end surface 17b of the cap 17 comes into contact with the substrate B. The material of the elastic body 18 is a conductive material, and the anode 11 and the anode current conductor 19 are electrically connected to the positive electrode 14a of the battery 14 via the elastic body 18.

[0024] The mounting member 24 is made of an insulating material and has a hollow shape, and the electrolyte membrane 13 is attached to its inner wall surface. The mounting member 24 is detachable from the housing 15, and is screwed into the housing 15 with a screw, for example. With the mounting member 24 attached to the housing 15, the electrolyte membrane 13 covers the lower opening 15a of the housing 15 from below.

[0025] The insulating cover 20 covers the outside of the cap 17 and is made of an insulating material. As shown in Fig. 2, the insulating cover 20 is formed so as to be spaced apart from the surface B1 of the base material B when the end face 17b of the cap 17 is in contact with the surface B1 of the base material B.

[0026] As described above, according to the film forming apparatus 1 of the present embodiment, when the cap 17 is pressed downward with the electrolyte membrane 13 in contact with the substrate B, the elastic body 18 is compressed and deformed, and the anode 11 and the anode current conductor 19 are urged downward by the elastic body 18. As a result, the anode 11 and the anode current conductor 19 slide downward toward the electrolyte membrane 13 in the container 15. As a result, the liquid pressure of the electrolyte solution L contained between the anode 11 and the electrolyte membrane 13 increases, and the electrolyte membrane 13 can be made to conform to the surface B1 of the substrate B. When the cap 17 is further pressed downward, the end surface 17b of the cap 17 comes into contact with the surface B1 of the substrate B. As a result, the substrate B is conducted to the negative electrode 14b of the battery 14 through the cap 17, and a voltage is applied between the anode 11 and the substrate B. In this way, the electrolyte membrane 13 can be made to conform to the surface B1 of the substrate B and the formation of the metal film can be started by simply pressing the cap 17 downward.

[0027] In the above embodiment, the electrolytic solution L is directly accommodated in the accommodation space 15c of the accommodation body 15. However, a porous body (not shown) impregnated with the electrolytic solution L may be accommodated in the accommodation space 15c of the accommodation body 15. The material of the porous body may be, for example, a polymer having a water absorption function or a resin having an ion exchange function. The porous body may also be a so-called sponge (plastic foam). The porous body may be made of a material having compressive deformation property and flexibility, or may be made of a metal material having corrosion resistance against the electrolytic solution L.

[0028] When the cap 17 is pressed downward while the porous body made of a material having compressive deformation and flexibility is housed in the housing 15, the elastic body 18 is compressed and deformed, and the anode 11 applies a force to the porous body toward the electrolyte membrane 13. As a result, the porous body is compressed and deformed to conform to the electrolyte membrane 13, so that the electrolyte membrane 13 can be uniformly pressurized by the porous body. As a result, the electrolyte membrane 13 can be made to conform uniformly to the surface B1 of the substrate B. Furthermore, by impregnating the porous body housed in the housing space 15c of the housing 15 with the electrolyte solution L, leakage of the electrolyte solution L can be reduced.

[0029] The porous body may or may not be constrained by the container 15 while being contained in the container 15. When the porous body is constrained by the container 15, the weight of the electrolyte solution L is prevented from being applied to the electrolyte membrane 13 when the film forming apparatus 1 is separated from the substrate B, so that deformation of the electrolyte membrane 13 can be suppressed.

[0030] Next, a film forming method using the film forming apparatus 1 according to this embodiment will be described. Fig. 3 is a flow chart illustrating a film forming method for a metal film using the film forming apparatus 1 of Fig. 1. All steps of this film forming method are performed manually. This flow chart illustrates a case where the electrolyte L is directly (i.e., without using a porous body) contained in the containing space 15c of the containing body 15.

[0031] First, in S100, the various members constituting the film forming apparatus 1 are attached. As an example, the insulating cover 20 is attached to the cap 17, and the anode 11 and the anode current conductor 19 are housed in the container 15. Then, the battery 14, the elastic body 18, and the container 15 are placed in the internal space 17f of the cap 17. Specifically, the negative electrode 14b of the battery 14 is attached to the closing portion 17d of the cap 17, the positive electrode 14a of the battery 14 is attached to one end of the elastic body 18, and the anode current conductor 19 is attached to the other end of the elastic body 18.

[0032] Next, in S200, with the lower opening 15a of the container 15 facing upward, the electrolyte L is replenished into the accommodation space 15c of the container 15 from the side of the lower opening 15a of the container 15.

[0033] Thereafter, in S300, the mounting member 24 to which the electrolyte membrane 13 is attached is screwed into the housing 15. As a result, the lower opening 15a of the housing 15 is covered with the electrolyte membrane 13.

[0034] Next, in S400, a pretreatment is performed on the surface B1 of the substrate B. In this step, foreign matter and a passive film attached to the surface B1 of the substrate B are removed in order to ensure the electrical conductivity of the surface B1 of the substrate B.

[0035] In S500, the substrate B is placed in the membrane forming apparatus 1. Specifically, the surface B1 of the substrate B is brought into contact with the electrolyte membrane 13, as shown in FIG.

[0036] In S600, as shown in FIG. 2, a predetermined force F is applied to the film forming apparatus 1 to press the film forming apparatus 1 against the substrate B. Specifically, in a state in which the electrolyte membrane 13 is in contact with the substrate B, the cap 17 is pressed downward with a predetermined force F. This compresses and deforms the elastic body 18, and the anode 11 is urged downward by the elastic body 18, and the anode 11 slides downward toward the electrolyte membrane 13 in the container 15. As a result, the liquid pressure of the electrolyte solution L contained between the anode 11 and the electrolyte membrane 13 increases, and the electrolyte membrane 13 can be made to conform to the surface B1 of the substrate B. When the cap 17 is further pressed downward, the end surface 17b of the cap 17 comes into contact with the surface B1 of the substrate B, and the substrate B is electrically connected to the negative electrode 14b of the battery 14 through the cap 17. As a result, a voltage is applied between the anode 11 and the substrate B, and the formation of the metal film is started.

[0037] In S700, a force F is continuously applied to the film forming apparatus 1, thereby maintaining the end face 17b of the cap 17 in contact with the surface B1 of the substrate B, and forming a metal film.

[0038] In S800, the force F applied to the film forming apparatus 1 is removed, and the end face 17b of the cap 17 is separated from the surface B1 of the substrate B by the restoring force of the elastic body .

[0039] In S900, residues on the surface B1 of the base material B are removed, for example, by wiping, and the formation of the metal coating is completed.

[0040] Next, a film forming apparatus 1A according to another embodiment will be described. Fig. 4 is a schematic cross-sectional view of a film forming apparatus 1A for a metal film according to another embodiment of the present invention, showing a state in which the cap 17 is separated from the substrate B. The film forming apparatus 1A according to the other embodiment differs from the film forming apparatus 1 according to the above embodiment in the configuration of the power supply unit, the configuration of the anode current conductor 19, the configuration of the cap 17, and the configuration of the insulating cover 20. Hereinafter, configurations having the same or similar functions as those of the film forming apparatus 1 according to the above embodiment will be denoted by the same reference numerals and their description will be omitted, and different parts will be described.

[0041] The film forming apparatus 1A according to this embodiment applies a voltage between the anode 11 and the substrate B using an external power supply (power supply unit) not shown. As an example, the positive electrode of the external power supply is connected to the handle 19b of the anode current conductor 19 via the positive electrode side conductor 14c. The handle 19b of the anode current conductor 19 is a rod-shaped portion extending upward from the anode contact portion 19a that is in direct contact with the anode 11. As an example, the negative electrode of the external power supply is connected to the sheath portion 17g of the cap 17 described later via the negative electrode side conductor 14d.

[0042] The cap 17 has a hollow cylindrical sheath portion 17g extending upward from the closing portion 17d. The inside of the sheath portion 17g and the internal space 17f of the cap 17 are in communication with each other via a through space that vertically passes through the closing portion 17d of the cap 17. A hollow cylindrical insulating sleeve 22 is attached to the inner wall surface that separates the inside of the sheath portion 17g from the through space of the closing portion 17d. The handle portion 19b of the anode current conductor 19 is slidable within the insulating sleeve 22.

[0043] In addition, an insulating sheet 23 is attached to the blocking portion 17d on the side of the internal space 17f of the cap 17, and the elastic body 18 surrounds the handle portion 19b of the anode current conductor 19 and is disposed between the insulating sheet 23 and the anode contact portion 19a.

[0044] As an example, the insulating cover 20 is attached to the outside of the cap 17 so as to be in direct contact with the side wall portion 17e, the closing portion 17d, and the sheath portion 17g of the cap 17. The insulating cover 20 covers the sheath portion 17g and the closing portion 17d of the cap 17 so as not to expose the sheath portion 17g and the closing portion 17d to the outside. The insulating cover 20 is movable in the vertical direction together with the cap 17.

[0045] In the film forming apparatus 1A of this embodiment, a voltage is applied to the anode 11 and the substrate B using an external power supply, so that film formation can be performed with higher output and for a longer period of time compared to the film forming apparatus 1 of the above embodiment.

[0046] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the film forming apparatus 1, 1A according to the above-mentioned embodiments, and includes all aspects included in the concept of the present invention and the scope of the claims. In addition, each configuration may be appropriately and selectively combined to achieve the above-mentioned problems and effects. For example, the shape, material, arrangement, size, etc. of each component in the above-mentioned embodiments may be appropriately changed according to the specific aspects of the present invention. [Explanation of symbols]

[0047] 1, 1A: film forming device, 11: anode, 13: solid electrolyte membrane, 14: battery (power supply unit), 15: container, 15a: lower opening (opening), 17: cap, 17a: end, 17b: end face, 18: elastic body, B: substrate, B1: surface, L: electrolyte

Claims

[Claim 1] An anode; a solid electrolyte membrane disposed between the anode and a substrate; a power supply unit that applies a voltage between the anode and the substrate, the substrate being a cathode; an insulating container that covers an opening on the side of the base material with the solid electrolyte membrane, accommodates the anode at a position spaced from the solid electrolyte membrane so as to be slidable in a direction toward the solid electrolyte membrane, and accommodates an electrolytic solution containing metal ions between the solid electrolyte membrane and the anode, a voltage is applied between the anode and the substrate in a state in which the solid electrolyte membrane is in contact with the substrate, and the metal ions contained inside the solid electrolyte membrane are reduced to form a metal coating derived from the metal ions on a surface of the substrate, the film forming apparatus includes a conductive cap that covers the container from the anode side, and an elastic body that is disposed between the cap and the anode; The positive electrode of the power supply unit is connected to the anode, The negative electrode of the power supply unit is connected to the cap, an end of the cap is formed to be spaced from the substrate when the solid electrolyte membrane is in contact with the substrate, and the elastic body is freely compressively deformed by pressing the cap toward the anode until the end face of the cap comes into contact with the substrate.

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