Masking material, and apparatus and method for forming a metal film using the same.

Abstract

To provide a masking material using which a metallic film F with a rectangular cross-sectional shape can be deposited.SOLUTION: A masking material 60 is used as a masking material 60 for depositing a metallic film F by electrolytic plating, having a prescribed pattern on the surface of a substrate B in a state that the film is pressed by a polymer electrolyte 13. In the masking material 60, penetration parts 68 are formed according to the prescribed pattern. At least a mask part 65 contacting the substrate B is made of an elastic material among the masking material 60. An expanding part 68a in the penetration part 68 is formed so as to expand outward as coming inside from a part 68c contacting the substrate B along in the thickness direction of the mask part 65, in which the cross-sectional shape of a formation space S in which the metallic film F for the penetration part 68 is rectangular in a state that the mask part 65 is elastically deformed by a pressing force of the polymer electrolyte 13.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a masking material, a film forming apparatus for a metal film using the same, and a film forming method.

Background Art

[0002] Conventionally, metal has been deposited on the surface of a substrate by electrolytic plating to form a metal film (for example, Patent Document 1). Patent Document 1 discloses that a film forming apparatus includes a container for storing a plating solution. An opening is formed in the container, and the opening is sealed with an electrolyte membrane. The film forming apparatus further includes a pressing mechanism that presses the substrate with the electrolyte membrane by the hydraulic pressure of the plating solution.

[0003] Here, when a metal underlayer having a predetermined pattern is formed on the surface of the substrate, a voltage is applied between the anode and the substrate while pressing the substrate with the hydraulic pressure of the electrolyte membrane. Thereby, a metal film having a predetermined pattern can be formed on the underlayer. However, when a predetermined pattern underlayer is not formed on the substrate, for example, it is also assumed to use a masking material shown in Patent Document 2. [[ID=|18]]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In this process, when forming a metal film, the masking material is sandwiched between the substrate and the electrolyte membrane. In this state, to ensure adhesion between the substrate and the masking material, the masking material is pressed by the electrolyte membrane acting on it due to the liquid pressure of the plating solution. However, if an elastic material is used for the masking material to improve its adhesion, the masking material may compress and deform, making it impossible to form a metal film with a rectangular cross-sectional shape.

[0006] The present invention has been made in view of these points, and aims to provide a masking material that can form a metal film with a rectangular cross-sectional shape. [Means for solving the problem]

[0007] In view of the above problems, the masking material according to the present invention is a masking material for forming a metal film of a predetermined pattern on the surface of a substrate by electroplating while being pressed by an electrolyte membrane, wherein the masking material has through portions formed according to the predetermined pattern, and at least the mask portion of the masking material that is in contact with the substrate is made of an elastic material, and the through portions have a widening portion that expands outward as it progresses from the portion in contact with the substrate in the thickness direction of the mask portion, such that when the mask portion is elastically deformed by the pressing force of the electrolyte membrane, the cross-sectional shape of the formation space for forming the metal film in the through portions becomes rectangular.

[0008] According to the present invention, since the mask portion is made of an elastic material, when the substrate is pressed by the electrolyte membrane through the masking material by the liquid pressure of the plating solution in contact with the electrolyte membrane, the mask portion elastically deforms. At this time, the mask portion elastically deforms so that the spread of the through portion narrows, so the cross-sectional shape of the formation space for forming the metal film in the through portion becomes rectangular. By forming a metal film on the surface of the substrate with a masking material that has undergone such elastic deformation, a metal film having a rectangular cross-sectional shape can be formed.

[0009] Here, the shape of the penetration portion of the masking material is not particularly limited, as long as it elastically deforms into a rectangular shape due to the pressing force of the electrolyte membrane. However, in a more preferred embodiment, the widening portion of the penetration portion is a space formed to widen as it proceeds in the thickness direction from the portion in contact with the substrate and the portion in contact with the electrolyte membrane. More preferably, the side wall surface forming the widening portion is a curved concave surface along the thickness direction.

[0010] In this embodiment, when the substrate is pressed with the electrolyte membrane via the masking material, the mask portion undergoes elastic deformation. During film formation, the surface of the portion of the mask that contacts the substrate is constrained in close contact with the substrate, and the surface of the portion that contacts the electrolyte membrane is constrained in close contact with the electrolyte membrane. As a result, the mask portion deforms overall along the thickness direction due to the pressing force of the electrolyte membrane, making it easier for the mask portion to deform so that the wall surface forming the through portion and the surface of the substrate are perpendicular to each other. As a result, the overall cross-sectional shape of the formation space for forming the metal film in the through portion is more easily deformed into a precise rectangular shape. In particular, by making the side wall surface that forms the spreading portion a curved concave surface along the thickness direction, the through portion can be deformed into a more precise rectangular shape.

[0011] In another preferred embodiment, the widening portion of the through-hole is a space formed to widen as it progresses in the thickness direction, from the portion in contact with the substrate to the portion in contact with the electrolyte membrane.

[0012] In this embodiment, when the substrate is pressed with an electrolyte membrane via a masking material, the mask portion undergoes elastic deformation. During film formation, the surface of the portion of the mask that contacts the substrate is constrained in close contact with the substrate, and the surface of the portion that contacts the electrolyte membrane is constrained in close contact with the electrolyte membrane. As a result, the pressing force of the electrolyte membrane deforms the area near the portion in contact with the substrate, making it easier for the mask portion to deform so that the wall surface forming the through portion and the surface of the substrate are perpendicular to each other. As a result, the cross-sectional shape of the formation space where the metal film is formed in the through portion is easily deformed into a rectangular shape. In particular, by making the side wall surface that forms the spreading portion a curved concave surface along the thickness direction, the formation space can be deformed into a more precisely rectangular shape.

[0013] In a more preferred embodiment, the masking material comprises a mesh portion with openings formed in a grid pattern, and the mask portion is fixed to the mesh portion.

[0014] In this embodiment, since the mask portion is fixed to the mesh portion, the mask portion can be uniformly pressed through the mesh portion, and therefore the mask portion can be uniformly elastically deformed by the pressing force from the electrolyte membrane.

[0015] The present invention discloses a metal film deposition apparatus equipped with the masking material described above. The deposition apparatus according to the present invention comprises: a container having an opening formed at a position facing the substrate and containing a plating solution, with the opening covered by the electrolyte membrane; a moving mechanism for moving at least one of the container and the substrate so that the electrolyte membrane and the substrate can move toward and away from each other via the masking material; a pressure increasing mechanism for increasing the liquid pressure of the plating solution contained in the container; an anode disposed inside the container at a position facing the electrolyte membrane; a power supply for applying a voltage between the anode and the substrate; and the masking material disposed between the electrolyte membrane and the substrate.

[0016] According to the present invention, a moving mechanism brings the electrolyte membrane and the substrate into contact via a masking material. In this state, a pressure-boosting mechanism presses the substrate with the electrolyte membrane via the masking material using the liquid pressure of the plating solution in contact with the electrolyte membrane. As a result, the mask portion elastically deforms, changing the cross-sectional shape of the formation space for forming the metal film in the through-hole portion to a rectangular cross-sectional shape, and the plating solution contained in the container seeps out from the electrolyte membrane and fills the through-hole portion. In this state, when a voltage is applied between the anode and the substrate by a power supply, metal ions contained in the plating solution can pass through the electrolyte membrane, and a metal film derived from the metal ions can be formed on the substrate in a predetermined pattern. The cross-sectional shape of the formed metal film is a rectangular cross-sectional shape corresponding to the cross-sectional shape of the through-hole portion.

[0017] The present invention discloses a method for forming a metal film using the masking material described above. The film formation method according to the present invention involves covering a substrate with the masking material, pressing the substrate with the electrolyte membrane through the masking material by the liquid pressure of the plating solution in contact with the electrolyte membrane, and applying a voltage between the anode in contact with the plating solution and the substrate to allow metal ions contained in the plating solution to pass through the electrolyte membrane, thereby forming a metal film derived from the metal ions on the substrate in the predetermined pattern.

[0018] According to the present invention, the substrate is covered with a masking material, and the substrate is pressed by the electrolyte membrane through the masking material by the liquid pressure of the plating solution in contact with the electrolyte membrane. As a result, the mask portion is elastically deformed, and the cross-sectional shape of the formation space for forming the metal film in the through-portion can be changed to a rectangular cross-sectional shape. At the same time, the plating solution contained in the container seeps out from the electrolyte membrane and fills the through-portion. In this state, when a voltage is applied between the anode and the substrate, metal ions contained in the plating solution can pass through the electrolyte membrane, and a metal film derived from the metal ions can be formed on the substrate in a predetermined pattern. The cross-sectional shape of the formed metal film is a rectangular cross-sectional shape corresponding to the cross-sectional shape of the through-portion. [Effects of the Invention]

[0019] According to the present invention, a metal film having a rectangular cross-sectional shape can be formed.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic cross-sectional view showing an example of a film forming apparatus for a metal film according to the first embodiment of the present invention. [Figure 2] It is a schematic perspective view showing the masking material shown in FIG. 1 and the substrate on which the metal film is formed. [Figure 3] It is a view for explaining the masking material using the film forming apparatus shown in FIG. 1, and is an enlarged cross-sectional view taken along the line A-A of FIG. 2. [Figure 4A] It is a schematic cross-sectional view for explaining the manufacturing method of the masking material shown in FIG. 2. [Figure 4B] It is a schematic cross-sectional view for explaining the manufacturing method of the masking material shown in FIG. 2. [Figure 4C] It is a schematic cross-sectional view for explaining the manufacturing method of the masking material shown in FIG. 2. [Figure 4D] It is a schematic cross-sectional view for explaining the manufacturing method of the masking material shown in FIG. 2. [Figure 5] It is a schematic cross-sectional view for explaining the film formation by the film forming apparatus shown in FIG. 1. [Figure 6A] It is a schematic view for explaining the arrangement process using the masking material according to the first embodiment. [Figure 6B] It is a schematic view for explaining the pressing process using the masking material according to the first embodiment. [Figure 6C] It is a schematic view for explaining the film formation process using the masking material according to the first embodiment. [Figure 7A] It is a schematic view for explaining the arrangement process using the masking material according to the second embodiment. [Figure 7B] It is a schematic view for explaining the pressing process using the masking material according to the second embodiment. [Figure 7C]This is a schematic diagram illustrating the film formation process using a masking material according to the second embodiment. [Figure 8A] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 8B] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 8C] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 8D] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 8E] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 8F] Figure 7A is a schematic cross-sectional view illustrating the manufacturing method of the masking material. [Figure 9A] This is a schematic diagram illustrating the placement process using masking material according to the third embodiment. [Figure 9B] This is a schematic diagram illustrating the pressing process using a masking material according to the third embodiment. [Figure 9C] This is a schematic diagram illustrating the film formation process using a masking material according to the third embodiment. [Modes for carrying out the invention]

[0021] First, a film deposition apparatus 1 used in a metal film deposition method according to an embodiment of the present invention will be described. Figure 1 is a schematic cross-sectional view showing an example of a metal film deposition apparatus according to the first embodiment of the present invention.

[0022] As shown in Figure 1, the film deposition apparatus 1 is a film deposition apparatus that deposits a metal film F of a predetermined pattern P onto a substrate B by electroplating, with a masking material 60 sandwiched between the electrolyte membrane 13 and the substrate B. Specifically, the film deposition apparatus 1 comprises an anode 11, an electrolyte membrane 13, and a power supply 14 that applies a voltage between the anode 11 and the substrate B.

[0023] The film deposition apparatus 1 comprises a container 15 containing an anode 11 and a plating solution L, a mounting table 40 on which the substrate B is placed, and a masking material 60. During film deposition, the masking material 60 is placed on the mounting table 40 together with the substrate B. The electrolyte membrane 13 is placed between the masking material 60 and the anode 11.

[0024] The film deposition apparatus 1 is equipped with a linear actuator 70 for raising and lowering the containment 15. The linear actuator 70 corresponds to the "movement mechanism" of the present invention and is a device that moves at least one of the containment 15 and the substrate B so that the electrolyte membrane 13 and the substrate B can move toward and away from each other via the masking material 60 described later. Therefore, the linear actuator 70 may be provided on the mounting table 40. In this embodiment, for the sake of explanation, it is assumed that the electrolyte membrane 13 is placed below the anode 11, and the masking material 60 and substrate B are placed further below it. However, the positional relationship is not limited to this, as long as a metal film F can be deposited on the surface of the substrate B.

[0025] Substrate B functions as a cathode. Substrate B is a plate-shaped substrate. In this embodiment, substrate B is a rectangular substrate. Of the surfaces of substrate B, the surface facing the electrolyte film 13 (screen mask 62) is the film-forming surface that functions as a cathode. The material of substrate B is not particularly limited as long as it functions as a cathode (i.e., a conductive surface). Substrate B may be made of a metallic material such as aluminum or copper.

[0026] In this embodiment, as shown in Figure 2, a wiring pattern is formed from a metal film F. Therefore, as the substrate B, a substrate with an underlayer Bb made of copper or the like formed on the surface of an insulating substrate Ba such as resin is used. In this case, after the metal film F is formed, the underlayer Bb other than the area where the metal film F is formed is removed by etching or the like. This makes it possible to form a pattern (wiring pattern) P made of metal film F on the surface of the insulating substrate Ba.

[0027] The anode 11 is, for example, a non-porous (e.g., non-porous) anode made of the same metal as the metal film. The anode 11 has a block-like or plate-like shape. Examples of materials for the anode 11 include copper. The anode 11 dissolves when a voltage is applied from the power supply 14. However, when forming a film using only metal ions from the plating solution L, the anode 11 is insoluble in the plating solution L. The anode 11 is electrically connected to the positive electrode of the power supply 14. The negative electrode of the power supply 14 is electrically connected to the substrate B via the mounting base 40.

[0028] The plating solution L is a liquid containing the metal to be formed into a metal film in an ionic state. Examples of such metals include copper, nickel, gold, silver, or iron. The plating solution L is a solution obtained by dissolving (ionizing) these metals with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphate. Examples of solvents for this solution include water and alcohol. For example, if the metal is copper, the plating solution L may be an aqueous solution containing copper sulfate, copper pyrophosphate, etc.

[0029] The electrolyte membrane 13 is a membrane that, when brought into contact with the plating solution L, can impregnate (contain) metal ions together with the plating solution L. The electrolyte membrane 13 is a flexible membrane. The material of the electrolyte membrane 13 is not particularly limited as long as the metal ions of the plating solution L can move to the substrate B side when a voltage is applied by the power supply 14. Examples of materials for the electrolyte membrane 13 include ion-exchange resins such as fluoropolymer resins such as Nafion® manufactured by DuPont. The thickness of the electrolyte membrane 13 is preferably in the range of 20 μm to 200 μm. More preferably, the thickness is in the range of 20 μm to 60 μm.

[0030] The container 15 is made of a material insoluble in the plating solution L. The container 15 has a containment space 15a for containing the plating solution L. The anode 11 is placed in the containment space 15a of the container 15. An opening 15d is formed on the substrate B side of the containment space 15a. The opening 15d of the container 15 is covered with an electrolyte membrane 13. Specifically, the periphery of the electrolyte membrane 13 is sandwiched between the container 15 and the frame 17. This allows the plating solution L in the containment space 15a to be sealed with the electrolyte membrane 13.

[0031] As shown in Figures 1 and 3, the linear actuator 70 raises and lowers the housing 15 so that the electrolyte membrane 13 and the masking material 60 can move in and out of contact. In this embodiment, the mounting base 40 is fixed, and the housing 15 is raised and lowered by the linear actuator 70. The linear actuator 70 is an electrically operated actuator that converts the rotational motion of a motor into linear motion using a ball screw or the like (not shown). However, a hydraulic or pneumatic actuator may be used instead of an electrically operated actuator.

[0032] The housing 15 has a supply channel 15b for supplying the plating solution L to the housing space 15a. Furthermore, the housing 15 has a discharge channel 15c for discharging the plating solution L from the housing space 15a. The supply channel 15b and the discharge channel 15c are holes that communicate with the housing space 15a. The supply channel 15b and the discharge channel 15c are formed on either side of the housing space 15a. The supply channel 15b is fluidically connected to the liquid supply pipe 50. The discharge channel 15c is fluidically connected to the liquid discharge pipe 52.

[0033] The film deposition apparatus 1 further comprises a liquid tank 90, a liquid supply pipe 50, a liquid discharge pipe 52, and a pump 80. As shown in Figure 1, the liquid tank 90 contains the plating solution L. The liquid supply pipe 50 connects the liquid tank 90 to the housing 15. The pump 80 is provided on the liquid supply pipe 50. The pump 80 supplies the plating solution L from the liquid tank 90 to the housing 15. The liquid discharge pipe 52 connects the liquid tank 90 to the housing 15. The liquid discharge pipe 52 is provided on the pressure regulating valve 54. The pressure regulating valve 54 adjusts the pressure (liquid pressure) of the plating solution L in the housing space 15a to a predetermined pressure.

[0034] In this embodiment, the plating solution L is drawn from the liquid tank 90 into the liquid supply pipe 50 by driving the pump 80. The drawn-in plating solution L is then pumped from the supply channel 15b to the containment space 15a. The plating solution L in the containment space 15a is returned to the liquid tank 90 via the discharge channel 15c. In this way, the plating solution L circulates within the film deposition apparatus 1.

[0035] Furthermore, by continuously driving the pump 80, the liquid pressure of the plating solution L in the containment space 15a can be maintained at a predetermined pressure by the pressure regulating valve 54. The pump 80 presses the masking material 60 with the electrolyte membrane 13, which is acted upon by the liquid pressure of the plating solution L. The pump 80 increases the liquid pressure of the plating solution L contained in the containment body 15 and corresponds to the "pressure boosting mechanism" of the present invention. However, the pressure boosting mechanism is not particularly limited as long as the electrolyte membrane 13 can press the masking material 60. Instead of the pump 80, an injection mechanism consisting of a piston and cylinder that injects the plating solution L may also be used.

[0036] The mounting base 40 is formed, for example, from a conductive material (e.g., metal). The mounting base 40 has a recess 41. The recess 41 is a portion recessed from the opposing surface 40a of the mounting base 40 in order to accommodate the base material B.

[0037] Figure 2 is a schematic perspective view of the masking material 60 of the film deposition apparatus 1 shown in Figure 1, and a schematic perspective view of the substrate B on which the metal film F has been deposited. Figure 3 is a cross-sectional view showing the main parts of the masking material 60 placed on the substrate B. The masking material 60 comprises a frame 61 and a screen mask 62.

[0038] The frame 61 supports the peripheral edge 62a of the screen mask 62 on the electrolyte membrane 13 side relative to the frame 61. Specifically, the peripheral edge 62a of the screen mask 62 is fixed to the frame 61. In this embodiment, the screen mask 62 has a rectangular outer shape. Therefore, the frame 61 has a rectangular frame-like shape. The material of the frame 61 is not particularly limited as long as it can maintain the shape of the masking material 60. For example, the material of the frame 61 can be a metal material such as stainless steel, or a resin material such as thermoplastic resin. The frame 61 is formed, for example, by punching out a metal plate and has a thickness of about 1 mm to 3 mm.

[0039] The screen mask 62 has through-portions 68 formed according to a predetermined pattern P of the metal film F. The screen mask 62 comprises a mesh portion 64 and a mask portion 65. The screen mask 62 is a mask with a flexibility of approximately 50 μm to 400 μm. The screen mask 62 is supported by the frame 61 on the substrate B side.

[0040] The mesh portion 64 is fixed to the frame 61. The mesh portion 64 is stretched with a predetermined tension so as to cover the opening of the frame 61. The mesh portion 64 has a grid of multiple openings 64c, 64c, ... formed in a grid pattern. Specifically, as shown in Figure 3, the mesh portion 64 is a mesh-like portion in which multiple oriented wires 64a, 64b are woven together so as to intersect. The multiple wires 64a, 64a are arranged with gaps between them, and the multiple intersecting wires 64b, 64b are also arranged with gaps between them. As a result, multiple openings 64c, 64c, ... are formed in a grid pattern in the mesh portion 64. The material of the wires 64a, 64b is not particularly limited as long as it has corrosion resistance to the plating solution L. Examples of materials for the wires 64a, 64b include metal materials such as stainless steel, or resin materials such as polyester.

[0041] The mask portion 65 is fixed to the mesh portion 64. The mesh portion 64 is fixed to the center of the mask portion 65 in the thickness direction. The mask portion 65 has through portions 68 formed according to a predetermined pattern P. The mask portion 65 is the part that adheres to the substrate B during film formation due to pressure from the electrolyte membrane 13. The material of the mask portion 65 is not particularly limited as long as it can adhere to the substrate B. For example, the material of the mask portion 65 can be a resin material such as acrylic resin, vinyl acetate resin, polyvinyl chloride resin, polypropylene resin, polyethylene resin, polyethylene resin, polystyrene resin, polycarbonate resin, polyimide resin, urethane resin, or polyester resin, or a rubber material such as silicone rubber (PMDS) or ethylene propylene diene rubber (EPDM). The hardness of the rubber material is preferably HS100 or less on the Shore A hardness scale, and more preferably HS50 or less.

[0042] The mask portion 65 is made of an elastic material that undergoes compressive elastic deformation upon pressure from the electrolyte membrane 13. To ensure adhesion with the substrate B, the amount of deformation of the mask portion 65 in the thickness direction (pressure direction) due to pressure from the electrolyte membrane 13 may be in the range of 5 to 20% of the thickness of the mask portion before deformation. A screen mask 62 having a predetermined pattern P can be manufactured using general silkscreen manufacturing techniques using emulsions. Therefore, a detailed explanation of the manufacturing method of the screen mask 62 is omitted.

[0043] In this embodiment, as shown in Figure 6B, the mask portion 65 is elastically deformed by the pressing force of the electrolyte membrane 13. In this deformed state, the shape of the through portion 68 before deformation is such that the cross-sectional shape of the formation space S for forming the metal film F in the through portion 68 of the mask portion 65 becomes rectangular. The shape of the through portion 68 of the mask portion 65 can be determined by prior analysis, but it may also be determined, for example, by actually creating a masking material and conducting experiments. The formation space S is the space from the surface of the substrate B to the thickness of the metal film F to be formed.

[0044] In this embodiment, as shown in Figures 3 and 6A, the through portion 68 has a widening portion 68a that expands outward as it progresses from the portion 68c that contacts the substrate B to the thickness direction of the mask portion 65. During film formation, the space other than the formation space S of the through portion 68 is filled with seepage liquid La. More specifically, the widening portion 68a of the through portion 68 is a space formed to expand as it progresses in the thickness direction from the portion 68c that contacts the substrate B and the portion 68d that contacts the electrolyte membrane 13. Here, the side wall surface 68e that forms the widening portion 68c is a curved concave surface along the thickness direction.

[0045] A method for manufacturing such a masking material 60 will now be described. First, a frame 61 to which a screen mask 62 is fixed is prepared. Next, uncured ultraviolet-curable resin 86 is applied to both sides of the screen mask 62 using a roller or brush and placed on a resin plate 81 (see Figure 4A). Next, ultraviolet UV light is irradiated onto the ultraviolet-curable resin (emulsion) 86 according to a predetermined pattern P to form a cured portion 86a according to the predetermined pattern. Next, the uncured portion 86b shown in Figure 4A is washed away to form a molding space 86c for molding the mask portion 65 as shown in Figure 4B.

[0046] Next, as shown in Figure 4C, the hardened portion 86a is swollen. If the resin of the hardened portion 86a is a resin that swells in water, the hardened portion 86a is swollen by exposing it to water vapor or immersing it in water. If the resin of the hardened portion 86a is a resin that swells in an organic solvent, the hardened portion 86a is swollen by immersing it in an organic solvent. This makes it possible to form a molded space 86c that narrows as it moves towards the center in the thickness direction. Finally, as shown in Figure 4D, the resin or rubber that will be the material for the mask portion 65 is poured into this molded space 86c to form the mask portion 65, the hardened portion 86a is removed by etching, and the resin plate 81 is removed from the mask portion 65. This makes it possible to obtain a masking material 60 having the mask portion 65 shown in Figure 3.

[0047] A film deposition method using the film deposition apparatus 1 will be described with reference to Figures 1, 5, and 6A to 6C. First, a placement step is performed as shown in Figures 1 and 6A. In this step, the substrate B is placed on the mounting table 40 as shown in Figure 1. Specifically, the substrate B is housed in the recess 41 of the mounting table 40. In this embodiment, with the substrate B housed in the recess 41, the surface of the substrate B protrudes from the opposing surface 40a of the mounting table 40 (the surface facing the electrolyte membrane 13). This allows the mask portion 65 of the masking material 60 to make uniform contact with the surface of the substrate B. At this time, the alignment of the substrate B with respect to the anode 11 attached to the housing 15 may be adjusted, and the temperature of the substrate B may be adjusted.

[0048] Next, the masking material 60 is placed on the mounting base 40. At this time, the masking material 60 is placed so that the surface of the base material B is contained within the internal space 69 of the frame 61 of the masking material 60. As a result, as shown in Figure 6A, the surface of the base material B (the surface of the underlayer Bb) is covered with the mask portion 65 of the masking material 60.

[0049] Next, the pressing process shown in Figures 5 and 6B is performed. In this process, the electrolyte membrane 13 presses the substrate B with the electrolyte membrane 13 through the screen mask 62 using the liquid pressure of the plating solution L in contact with the electrolyte membrane 13. First, the linear actuator 70 is driven. This lowers the housing 15 toward the masking material 60 from the state shown in Figure 1 to the state shown in Figure 5. If the masking material 60 is integrally attached to the housing 15 at a position facing the electrolyte membrane 13, lowering the housing 15 allows the surface of the substrate B to be covered with the mask portion 65 of the masking material 60.

[0050] Next, the pump 80 is driven. This supplies the plating solution L to the containment space 15a of the containment body 15. Since the liquid discharge pipe 52 is equipped with a pressure regulating valve 54, the liquid pressure of the plating solution L in the containment space 15a is maintained at a predetermined pressure. As a result, as shown in Figure 5, the liquid pressure of the plating solution L causes the electrolyte membrane 13 to deform toward the internal space 69 of the frame 61, allowing the screen mask 62 to be sandwiched between the electrolyte membrane 13 and the substrate B. Furthermore, the liquid pressure of the plating solution L acts on the electrolyte membrane 13, which can press down on the masking material 60.

[0051] As shown in Figure 6B, this pressure allows the screen mask 62 to adhere tightly to the surface of the substrate B. If the mask portion 65 is made of rubber, the liquid pressure of the plating solution L causes the mask portion 65 to compress and elastically deform, improving the adhesion between the mask portion 65 and the substrate B.

[0052] Specifically, the pressing force of the electrolyte membrane 13 during the pressing process causes the mask portion 65 to elastically deform so that the expansion of the widened portion 68a of the through portion 68 narrows. With the mask portion 65 elastically deformed, the cross-sectional shape of the formation space S where the metal film F of the through portion 68 is formed becomes rectangular. In this embodiment, the widened portion 68a of the through portion 68 is a space formed to widen as it proceeds in the thickness direction from the portion 61c that contacts the substrate B and the portion 71d that contacts the electrolyte membrane 13. Therefore, the entire through portion 68 becomes substantially rectangular in shape. In particular, by making the side wall surface 68e that forms the widened portion 68a a curved concave surface along the thickness direction, the through portion 68 can be deformed into a more precisely rectangular shape.

[0053] Furthermore, since the mask portion 65 is fixed to the mesh portion 64, the mask portion 65 can be uniformly pressed through the mesh portion 64. As a result, the pressing force from the electrolyte membrane 13 causes the mask portion 65 to be uniformly elastically deformed, and the shape of each through portion 68 can be deformed into a stable rectangular shape.

[0054] Thus, as shown in Figure 6B, the mask portion 65 deforms so that the side wall surface 68e forming the through portion 68 and the surface (film-forming surface) Bf of the substrate B are substantially perpendicular. In this embodiment of the present invention, the angle θ between the side wall surface 68e and the surface Bf is preferably in the range of 85° to 95°.

[0055] Furthermore, as the pressure on the electrolyte membrane 13 is sustained, as shown in Figure 6B, the seepage solution (plating solution) La that has seeped out from the electrolyte membrane 13 swollen by the plating solution L fills the perforations 68 formed in the screen mask 62.

[0056] Next, as shown in Figures 5 and 6C, a film formation process is carried out. In this process, the pressing state by the electrolyte membrane 13 from the pressing process is maintained, and a metal film F is formed. Specifically, a voltage is applied between the anode 11 and the substrate B. This causes the metal ions contained in the plating solution L to pass through the electrolyte membrane 13. The metal ions that have passed through the electrolyte membrane 13 move to the surface of the substrate B via the seepage solution La, and are reduced on the surface of the substrate B.

[0057] The seepage liquid La filling the through-hole 68 is sealed inside the through-hole 68 by the electrolyte membrane 13, so that a metal film F with a predetermined pattern can be formed on the surface of the substrate B (see Figure 2). The metal film F is a film derived from metal ions. Here, during film formation, the cross-sectional shape of the formation space S in the through-hole 68 where the metal film F is formed is rectangular. Therefore, as shown in Figure 6C, a metal film F having a rectangular cross-sectional shape can be formed.

[0058] In particular, since the through-portion 68 is a space formed to widen as it progresses from the substrate B to the electrolyte membrane 13, the cross-sectional shape of the formation space S in which the metal film F is formed in the through-portion 68 is more easily deformed into a rectangular cross-sectional shape with greater precision.

[0059] Furthermore, because the seepage liquid La is uniformly pressurized by the pressure of the electrolyte membrane 13, a homogeneous metal film F can be formed. Subsequently, the housing 15 is raised by the linear actuator 70 to separate the substrate B from the electrolyte membrane 13, and the substrate B is removed from the mounting table 40. When manufacturing wiring with the metal film F, it is sufficient to etch the conductive underlayer Bb formed on the surface of the insulating substrate Ba of the substrate B, leaving the portion where the metal film F is formed intact.

[0060] As described above, when the masking material 60 is integrally attached to the housing 15, when the linear actuator 70 raises the housing 15 and separates the substrate B from the electrolyte membrane 13, the masking material 60 can support the weight of the plating solution L through the electrolyte membrane 13. This prevents the electrolyte membrane 13 from undergoing plastic deformation due to the weight of the plating solution L.

[0061] Figure 7A is a schematic diagram illustrating the placement process using the masking material according to the second embodiment, Figure 7B is a schematic diagram illustrating the pressing process, and Figure 7C is a schematic diagram illustrating the film formation process. The difference between the second embodiment and the first embodiment shown in Figure 3 is the structure of the mask portion 65 of the masking material 60. Therefore, the differences from the above-described embodiment will be explained, and similar configurations will not be described in detail.

[0062] As shown in Figure 7A, this masking material 60 also has a mesh portion 64 in which openings 64c are formed in a grid pattern. The mask portion 65 is fixed to the mesh portion 64 on the surface of the mesh portion 64 on the base material B side. In this embodiment as well, the through portion 68 has a widened portion 68a such that when the mask portion 65 is elastically deformed, the cross-sectional shape of the forming space S for forming the metal film F of the through portion 68 becomes rectangular.

[0063] The expanding portion 68a is a space that expands outward as it proceeds from the portion 68c in contact with the substrate B to the portion 68d in the thickness direction of the mask portion 65. Specifically, the expanding portion 68a of the through portion 68 is a space formed to expand as it proceeds in the thickness direction from the portion 68c in contact with the substrate B to the portion 68d in contact with the electrolyte membrane 13. Here, if the thickness of the metal film F to be deposited is thin, the inclination angle φ of the side wall surface 68e forming the through portion 68 may be constant. In this embodiment, assuming the shape of this space, the inclination angle φ of the side wall surface 68e forming the through portion 68 increases as it proceeds from the substrate B side to the electrolyte membrane 13 side (as it proceeds in the thickness direction of the mask portion 65). Here, the inclination angle φ is the angle between the side wall surface 68e and the parallel virtual plane f1 of the surface on which the screen mask 62 extends in cross-section.

[0064] In this example, as shown in Figure 7B, when the substrate is pressed by the electrolyte membrane 13 through the masking material 60 by the liquid pressure of the plating solution L in contact with the electrolyte membrane 13, the pressing force acts on the mask portion 65 through the mesh portion 64. Here, as the substrate B moves towards the electrolyte membrane 13, the inclination angle φ of the side wall surface 68e increases, so the deformation of the mask portion 65 increases as the substrate B moves towards the electrolyte membrane 13. This prevents the side wall surface 68e of the through portion 68 from deforming in a way that causes it to bulge. As a result, the cross-sectional shape of the formation space S in which the metal film F is formed in the through portion 68 is more easily deformed into a more precise rectangular cross-sectional shape. Subsequently, in the film formation process, as shown in Figure 7C, a metal film F with a more precise rectangular cross-sectional shape can be formed.

[0065] A method for manufacturing such a masking material 60 will be explained with reference to Figures 8A to 8F. An uncured ultraviolet-curable resin 83 is applied to the surface of a copper sheet material 82 placed on the surface of a resin plate 81 using a roller or brush (see Figure 8A). Next, the ultraviolet-curable resin (emulsion) 83 is irradiated with ultraviolet UV light according to a predetermined pattern P to form a cured portion 83a corresponding to the predetermined pattern. After that, the uncured ultraviolet-curable resin is washed away, and the copper of the sheet material 82 is etched using an acidic aqueous solution. This makes it possible to form a void 82a corresponding to the shape of the through portion 68, as shown in Figure 8B. Therefore, the remaining portion 82b of the sheet material 82 has a shape corresponding to the mask portion 65. After that, as shown in Figure 8C, the cured portion 83a is removed from the remaining portion 82b of the sheet material 82.

[0066] Next, as shown in Figure 8D, uncured UV-curable resin 84 is filled into the voids of the sheet material 82, and as shown in Figure 8E, UV light is irradiated onto the filled UV-curable resin 84 to form a cured portion 84a. Then, as shown in Figure 8F, the copper of the remaining portion 82b is etched using an acidic aqueous solution. Finally, resin or rubber, which will be the material for the mask portion 65, is poured into the molded space 84b from which the remaining portion 82b has been removed to form the mask portion 65, the cured portion 84a is removed by etching, and the resin plate 81 is removed from the mask portion 65. This makes it possible to obtain a masking material 60 having the mask portion 65 shown in Figure 7A.

[0067] Figure 9A is a schematic diagram illustrating the placement process using the masking material according to the third embodiment, Figure 9B is a schematic diagram illustrating the pressing process, and Figure 9C is a schematic diagram illustrating the film formation process. The difference between the third embodiment and the second embodiment shown in Figure 7A is that the masking material 60 does not have a mesh portion 64 and is composed only of a mask portion 65. Therefore, the differences from the above-described embodiments will be explained, and similar configurations will not be described in detail.

[0068] As shown in Figure 9A, the masking material 60 consists only of the mask portion 65 of the embodiment. Therefore, the masking material 60 is easily elastically deformed in the compression direction. A through portion 68 is formed in the mask portion 65. The shape of the through portion 68 is the same as the shape shown in Figure 7A.

[0069] In this example, as shown in Figure 9B, when the substrate B is pressed by the electrolyte membrane 13 through the masking material 60 by the liquid pressure of the plating solution L in contact with the electrolyte membrane 13, the pressing force acts directly on the masking material 60 (mask portion 65). As a result, the cross-sectional shape of the formation space S where the metal film F is formed in the through-portion 68 is deformed into a rectangular cross-sectional shape. Since the through-portion 68 is a space formed to widen as it proceeds from the substrate B to the electrolyte membrane 13, the cross-sectional shape of the formation space S where the metal film F is formed in the through-portion 68 is precisely deformed into a rectangular cross-sectional shape. Subsequently, in the film formation process, as shown in Figure 9C, a metal film F with a precise rectangular cross-sectional shape can be formed.

[0070] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. [Explanation of symbols]

[0071] 1: Film deposition apparatus, 13: Electrolyte membrane, 40: Mounting platform, 41: Recess, 60: Masking material, 61: Frame, 62: Screen mask, 64: Mesh portion, 65: Mask portion, 68: Through portion, B: Substrate, F: Metal film, L: Plating solution

Claims

1. A masking material for forming a metal film with a predetermined pattern on the surface of a substrate by electroplating while it is pressed by an electrolyte membrane, The masking material has through-holes formed in accordance with the predetermined pattern. Of the masking material, at least the mask portion that comes into contact with the substrate is made of an elastic material. A masking material in which, when the mask portion is elastically deformed by the pressing force of the electrolyte membrane, the cross-sectional shape of the forming space for the metal film in the through portion becomes rectangular, and the through portion has a widening portion that extends outward as it progresses from the portion in contact with the substrate in the thickness direction of the mask portion.

2. The masking material according to claim 1, wherein the widened portion of the through-hole is a space formed to widen as it proceeds in the thickness direction from the portion in contact with the substrate and the portion in contact with the electrolyte membrane.

3. The masking material according to claim 2, wherein the side wall surface forming the spreading portion is a curved concave surface along the thickness direction.

4. The masking material according to claim 1, wherein the widened portion of the through-hole is a space formed to widen as it progresses in the thickness direction from the portion in contact with the substrate to the portion in contact with the electrolyte membrane.

5. The masking material comprises a mesh portion with openings formed in a grid pattern, The masking material according to claim 1, wherein the mask portion is fixed to the mesh portion.

6. A metal film deposition apparatus comprising the masking material described in claim 1, A container having an opening formed at a position opposite to the substrate, containing a plating solution, and the opening covered with the electrolyte membrane, A moving mechanism for moving at least one of the containment and the substrate so that the electrolyte membrane and the substrate can move toward and away from each other via the masking material, A pressure-boosting mechanism that increases the liquid pressure of the plating solution contained in the container, Inside the container, an anode is positioned opposite the electrolyte membrane, A power supply that applies a voltage between the anode and the substrate, A metal film deposition apparatus comprising the masking material disposed between the electrolyte membrane and the substrate.

7. A method for forming a metal film using the masking material described in claim 1, The substrate is covered with the aforementioned masking material. The liquid pressure of the plating solution in contact with the electrolyte membrane presses the substrate with the electrolyte membrane through the masking material. A method for forming a metal film, comprising applying a voltage between an anode in contact with the plating solution and the substrate, thereby causing metal ions contained in the plating solution to pass through the electrolyte membrane, and forming a metal film derived from the metal ions on the substrate in a predetermined pattern.

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