CN117917487A

CN117917487A - Film forming device for metal film

Info

Publication number: CN117917487A
Application number: CN202311340404.0A
Authority: CN
Inventors: 近藤春树; 黑田圭儿; 稻垣功二; 冈本和昭; 柳本博
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2022-10-20
Filing date: 2023-10-17
Publication date: 2024-04-23
Also published as: US20240133070A1; JP2024061035A

Abstract

Provided is a film forming device for a metal film, which can inhibit the penetration of effusion between a screen mask and a substrate during film forming. The mask structure (60) is provided with a screen mask (62) having a penetration portion (68) formed with a predetermined pattern (P). A screen mask (62) is provided with: a mesh portion (64) having openings (64 c) formed in a lattice shape, and a mask portion (65) fixed to the mesh portion (64) on the side of the base material (B) and having a through portion (68) formed therein. The mask portion (65) has: a core portion (65 a) which holds the shape of the mask portion (65), and a sealing portion (65B) which is made of an elastic material softer than the core portion (65 a) and is in contact with the base material (B).

Description

Film forming device for metal film

Technical Field

The present invention relates to a film forming apparatus for forming a metal film on a surface of a substrate in a predetermined pattern.

Background

Conventionally, a film forming apparatus has been proposed in which a metal film is formed by depositing a metal on a substrate surface (for example, patent document 1). In patent document 1, a film forming apparatus includes a housing for housing a plating solution. An opening is formed in the housing, and the opening is sealed with the electrolyte membrane. The film forming apparatus further includes a pressing mechanism that presses the base material through the electrolyte membrane for hydraulic pressure of the plating solution.

Here, in the case where a metal base layer having a predetermined pattern is formed on the surface of the substrate, a voltage is applied between the anode and the substrate in a state where the substrate is pressed by the hydraulic pressure of the electrolyte membrane. Thus, a metal coating film having a predetermined pattern can be formed on the base layer. However, when a base layer having a predetermined pattern is not formed on a substrate, it is also conceivable to use a mask material shown in patent document 2, for example.

Prior art literature

Patent document 1: japanese patent laid-open publication 2016-125087

Patent document 2: japanese patent laid-open publication 2016-108586

Disclosure of Invention

Here, in the case of film formation using a mask structure having a screen mask as a mask material, the mask structure is sandwiched between a base material and an electrolyte membrane. In this state, in order to ensure adhesion between the base material and the screen mask, the mask structure is pressed by the electrolyte membrane that is used as a hydraulic pressure of the plating solution. However, if the screen mask is not sufficiently adhered to the substrate, a metal film of a desired pattern cannot be formed.

Specifically, the screen mask is formed with through portions corresponding to a predetermined pattern. In the film formation, the penetrating portion is filled with a plating solution (permeate) that seeps out from the electrolyte membrane, and the permeate is pressurized by pressing the electrolyte membrane. As a result, the exudates may enter between the screen mask and the substrate, and a metal coating having a desired pattern may not be formed.

The present invention has been made in view of the above-described problems, and provides a film forming apparatus for a metal film, which can prevent exudates from entering between a screen mask and a substrate during film forming.

In view of the above problems, the metal film forming apparatus of the present invention is a metal film forming apparatus for forming a metal film having a predetermined pattern on a substrate by electrolytic plating in a state in which a mask structure is sandwiched between an electrolyte membrane and the substrate. The film forming apparatus includes a pressing mechanism that presses the mask structure with the electrolyte membrane by hydraulic pressure of the plating solution. The mask structure includes a screen mask having a through portion of the predetermined pattern formed therein. The screen mask includes a mesh portion in which openings are formed in a lattice shape, and a mask portion fixed to the mesh portion on the substrate side and in which the through portions are formed. The mask portion has a core portion that maintains the shape of the mask portion and a seal portion that is composed of an elastic material softer than the core portion and is in contact with the base material.

According to the present invention, first, the mask structure is sandwiched between the electrolyte membrane and the base material, and the mask structure is pressed by the pressing mechanism using the electrolyte membrane in which the hydraulic pressure of the plating solution acts. By this pressing, the sealing portion of the mask portion is brought into contact with the surface of the base material in an elastically deformed state. As a result, the screen mask can be brought into close contact with the substrate.

On the other hand, by pressing the electrolyte membrane, an exudate (plating solution) oozing from the electrolyte membrane swelled by the plating solution is filled into the through portions of the screen mask. The filled permeate is pressurized by the pressing of the electrolyte membrane. As described above, the sealing portion of the mask portion is in contact with the surface of the base material in an elastically deformed state. Further, the core portion is fixed to the mesh portion, and rigidity is higher than that of the seal portion. Therefore, even if there is a pressing of the electrolyte membrane, the shape of the through portion can be maintained. Since the through portion has a shape corresponding to the predetermined pattern, a metal film of the predetermined pattern can be formed on the surface of the base material by electrolytic plating.

For example, the sealing portion may extend along a side wall surface forming the through portion.

According to this example, the seal portion extends along the side wall surface forming the through portion, so the core portion is covered with the seal portion. Therefore, at the time of film formation, the core portion can be suppressed from coming into contact with the exudates filled in the through portion. As a result, deterioration and damage of the core portion can be suppressed, and rigidity of the mask portion can be maintained.

For example, it is preferable that the core portion has: an opposing face opposing the base material, and a side wall face forming the through portion, the sealing portion being formed along a ridge line formed by the opposing face and the side wall face.

According to this example, the seal portion is formed along the ridge line of the core portion, so the compression deformability of the seal portion can be improved by pressing the electrolyte membrane. As a result, a metal film having a pattern with higher accuracy can be formed.

For example, it is preferable that the hardness of the mask portion gradually becomes larger as it progresses from the seal portion toward the core portion.

In the case of repeatedly using the mask structure, the seal portion is repeatedly elastically deformed. Thereby, the sealing portion and the core portion are easily separated at their interface. However, according to this example, it is possible to suppress the hardness difference between the hardness of the seal portion and the hardness of the core portion from locally increasing. As a result, separation of the core portion and the seal portion can be prevented.

According to the present invention, the penetration of the exudates between the screen mask and the substrate can be suppressed during film formation.

Drawings

FIG. 1 is a schematic cross-sectional view showing an example of a metal film forming apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic perspective view of a mask structure of the film forming apparatus shown in fig. 1 and a schematic perspective view of a substrate on which a metal coating is formed.

Fig. 3A is an enlarged partial cross-sectional view taken along line A-A of fig. 2.

Fig. 3B is an enlarged sectional view of the portion C of fig. 3A.

Fig. 4 is a schematic cross-sectional view for explaining film formation by the film forming apparatus shown in fig. 1.

Fig. 5 is a main part sectional view of fig. 4.

Fig. 6 is a flowchart illustrating an example of a method for forming a metal film using the film forming apparatus according to the embodiment of the present invention.

Fig. 7A is a partial cross-sectional view of a mask structure of the film forming apparatus of modification 1.

Fig. 7B is a partial cross-sectional view of a mask structure of the film forming apparatus of modification 2.

Fig. 7C is a partial cross-sectional view of a mask structure of the film forming apparatus of modification 3.

Fig. 7D is a partial cross-sectional view of a mask structure of the film forming apparatus according to modification 4.

Fig. 8A is a schematic diagram for explaining a method of manufacturing a mask portion of the mask structure body of fig. 7B.

Fig. 8B is a schematic diagram for explaining a method of manufacturing a mask portion of the mask structure of fig. 7C.

Fig. 8C is a schematic diagram for explaining a method of manufacturing a mask portion of the mask structure of fig. 7D.

Fig. 9A is a partial cross-sectional view of a mask structure of the film forming apparatus of modification 5.

Fig. 9B is a partial cross-sectional view of a mask structure of the film forming apparatus of modification 6.

Description of the reference numerals

1: Film forming apparatus, 13: electrolyte membrane, 40: mounting table, 41: 1 st recess, 42: recess 2, 42b: opening edge, 60: mask structure, 61: frame body, 62: screen mask, 64: mesh portion, 65: mask portion, 65a: core portion, 65b: sealing portion, 68: penetration part, B: base material, L: plating solution

Detailed Description

First, a metal film forming apparatus 1 according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of a metal film forming apparatus according to an embodiment of the present invention.

As shown in fig. 1, the film forming apparatus 1 is a film forming apparatus for forming a metal film F of a predetermined pattern P on a substrate B by electrolytic plating in a state in which a mask structure 60 is sandwiched between an electrolyte membrane 13 and the substrate B. Specifically, the film forming apparatus 1 includes an anode 11, an electrolyte membrane 13, and a power supply 14 for applying a voltage between the anode 11 and the substrate B.

The film forming apparatus 1 includes a housing 15 housing the anode 11 and the plating liquid L, a stage 40 for placing the substrate B thereon, and a mask structure 60. At the time of film formation, the mask structure 60 is placed on the stage 40 together with the substrate B. The electrolyte membrane 13 is disposed between the mask structure 60 and the anode 11.

The film forming apparatus 1 includes a linear actuator 70 for elevating and lowering the storage body 15. In the present embodiment, for convenience of explanation, it is assumed that the electrolyte membrane 13 is disposed below the anode 11, and the mask structure 60 and the base material B are disposed below the electrolyte membrane. However, the positional relationship is not limited as long as the metal film F can be formed on the surface of the base material B.

The substrate B functions as a cathode. The material of the base material B is not particularly limited as long as it functions as a cathode (i.e., a surface having conductivity). The base material B may be made of a metal material such as aluminum or copper, for example. When the wiring pattern is formed by the metal film F, a base material in which a base layer such as copper is formed on the surface of an insulating substrate such as a resin is used as the base material B. In this case, after the formation of the metal film F, the underlayer other than the portion where the metal film F is formed is removed by etching or the like. Thus, the wiring pattern of the metal film F can be formed on the surface of the insulating substrate.

As an example, the anode 11 is a non-porous (e.g., non-porous) anode made of the same metal as that of the metal film. The anode 11 has a block or flat plate shape. Examples of the material of the anode 11 include copper. Anode 11 is dissolved by applying a voltage from power supply 14. However, in the case of film formation using only the metal ions of the plating solution L, the anode 11 is an anode insoluble in the plating solution L. Anode 11 is electrically connected to the positive electrode of power supply 14. The negative electrode of the power source 14 is electrically connected to the substrate B via the mounting table 40.

The plating liquid L is a liquid containing a metal of a metal coating film to be formed in an ionic state. Examples of the metal include copper, nickel, gold, silver, iron, and the like. The plating solution L is a solution in which these metals are dissolved (ionized) with an acid such as nitric acid, phosphoric acid, succinic acid, sulfuric acid, or pyrophosphoric acid. Examples of the solvent of the solution include water and ethanol. For example, when the metal is copper, the plating solution L may be an aqueous solution containing copper sulfate, copper pyrophosphate, or the like.

The electrolyte membrane 13 is a membrane that can be impregnated (containing) metal ions inside together with the plating solution L by contact with the plating solution L. The electrolyte membrane 13 is a membrane having flexibility. The material of the electrolyte membrane 13 is not particularly limited as long as the metal ions of the plating liquid L can move to the substrate B side when a voltage is applied from the power source 14. Examples of the material of the electrolyte membrane 13 include resins having an ion exchange function such as fluorine resins such as Nafion (registered trademark) manufactured by dupont. The film thickness of the electrolyte membrane is preferably in the range of 20 μm to 200 μm. More preferably, the film thickness is in the range of 20 μm to 60. Mu.m.

The housing 15 is made of a material insoluble in the plating liquid L. A housing space 15a for housing the plating solution is formed in the housing body 15. The anode 11 is disposed in the housing space 15a of the housing body 15. An opening 15d is formed in the storage space 15a on the substrate B side. The opening 15d of the housing 15 is covered with the electrolyte membrane 13. Specifically, the peripheral edge of the electrolyte membrane 13 is sandwiched between the housing 15 and the frame 17. This makes it possible to seal the plating liquid L in the housing space 15a with the electrolyte membrane 13.

As shown in fig. 1 and 4, the linear actuator 70 moves up and down the housing 15 so that the electrolyte membrane 13 and the mask structure 60 can be freely contacted and separated. In the present embodiment, the mounting table 40 is fixed, and the storage body 15 is lifted and lowered by the linear actuator 70. The linear actuator 70 is an electric actuator, and converts a rotational motion of a motor into a linear motion by a ball screw or the like (not shown). However, instead of an electric drive, a hydraulic or pneumatic drive may also be used.

The housing body 15 is formed with a supply channel 15b for supplying the plating liquid L to the housing space 15 a. A discharge channel 15c for discharging the plating liquid L from the storage space 15a is formed in the storage body 15. The supply channel 15b and the discharge channel 15c are holes communicating with the storage space 15 a. The supply channel 15b and the discharge channel 15c are formed so as to sandwich the storage space 15 a. The supply channel 15b is connected to the liquid supply pipe 50. The discharge flow path 15c is fluidly connected to the liquid discharge tube 52.

The film forming apparatus 1 further includes a liquid tank 90, a liquid supply pipe 50, a liquid discharge pipe 52, and a pump 80. As shown in fig. 1, a plating solution L is stored in a tank 90. The liquid supply pipe 50 connects the liquid tank 90 with the storage body 15. The liquid supply pipe 50 is provided with a pump 80. The pump 80 supplies the plating liquid 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 with a pressure regulating valve 54. The pressure adjustment valve 54 adjusts the pressure (hydraulic pressure) of the plating liquid L in the storage space 15a to a predetermined pressure.

In the present embodiment, the plating solution L is sucked from the liquid tank 90 into the liquid supply pipe 50 by driving the pump 80. The sucked plating liquid L is pumped from the supply channel 15b to the receiving space 15a. The plating solution L in the storage space 15a returns to the tank 90 through the discharge channel 15 c. Thus, the plating liquid L circulates in the film forming apparatus 1.

Further, by continuously driving the pump 80, the hydraulic pressure of the plating liquid L in the storage space 15a can be maintained at a predetermined pressure by the pressure adjusting valve 54. The pump 80 presses the mask structure 60 with the electrolyte membrane 13, which acts as a hydraulic pressure of the plating liquid L. Therefore, the pump 80 corresponds to a "pressing mechanism" in the present invention. However, the pressing mechanism is not particularly limited as long as the mask structure 60 can be pressed by the electrolyte membrane 13. An injection mechanism comprising a piston and a cylinder for injecting the plating solution may be used instead of the pump 80.

For example, the mounting table 40 is formed of a conductive material (for example, metal). The placement table 40 is formed with a1 st recess 41 and a 2 nd recess 42. The 1 st recess 41 is a recess for accommodating the base material B. The 2 nd recess is a recess for accommodating the mask structure 60 in a state in which the substrate B is accommodated in the 1 st recess 41.

Fig. 2 is a schematic perspective view of the mask structure 60 of the film forming apparatus 1 shown in fig. 1 and a schematic perspective view of the substrate B on which the metal film F is formed. Fig. 3A is a partially enlarged sectional view taken along the line A-A shown in fig. 2, and fig. 3B is an enlarged sectional view of the portion C of fig. 3A.

The mask structure 60 includes a frame 61 and a screen mask 62. The screen mask 62 is formed with through portions 68 corresponding to the predetermined pattern P of the metal film F. The screen mask 62 has a mesh portion 64 and a mask portion 65.

The frame 61 supports the peripheral edge 62a of the screen mask 62 on the side of the base material B (the side of the mounting table 40) with respect to the frame 61. Specifically, the peripheral edge 62a of the screen mask 62 is fixed to the frame 61. In the present embodiment, the screen mask 62 has a rectangular outer shape. Therefore, the frame 61 has a rectangular rim-like shape. The material of the frame 61 is not particularly limited as long as the shape of the mask structure 60 can be maintained. For example, the material of the housing 61 may be a metal material such as stainless steel or a resin material such as thermoplastic resin. The frame 61 is formed by punching a metal plate, for example, and has a thickness of about 1mm to 3 mm. In fig. 3A and the like, for convenience of explanation, the thickness of the frame 61 is drawn thicker than the actual thickness.

The mesh portion 64 has a plurality of openings 64c, … formed in a lattice shape. Specifically, as shown in fig. 3B, the mesh portion 64 is a mesh-like portion into which a plurality of oriented wires 64a, 64B are woven in a crossing manner. The plurality of wires 64a, 64a are arranged at intervals from each other, and the plurality of wires 64b, 64b intersecting them are arranged at intervals from each other. Thus, a plurality of openings 64c, … are formed in the mesh portion 64 in a lattice shape. The material of the wires 64a and 64b is not particularly limited as long as it has corrosion resistance to the plating solution L. Examples of the material of the wires 64a and 64b include a metal material such as stainless steel, a resin material such as polyester, and the like.

The mask portion 65 is fixed to the mesh portion 64 on the substrate B side with respect to the mesh portion 64. A penetrating portion 68 corresponding to the predetermined pattern P is formed at the mask portion 65. The mask portion 65 is a portion that adheres to the base material B at the time of film formation by pressing from the electrolyte membrane 13. The mask portion 65 has a core portion 65a that holds the shape of the mask portion 65, and a seal portion 65B that is made of an elastic material softer than the core portion and is in contact with the base material B.

As shown in fig. 3B, the core portion 65a is fixed to the mesh portion 64. A sealing portion 65B is formed on a surface (opposing surface 65 c) opposing the base material B among the surfaces of the core portion 65 a. The seal portion 65b is formed on the entire opposite face 65c of the core portion 65 a. The thickness of the sealing portion 65b is thinner than the thickness of the core portion 65 a. The thickness of the seal portion 65b is preferably in the range of about 1/5 to 1/10 with respect to the thickness of the core portion 65 a.

The core portion 65a may be made of a resin material such as an acrylic resin, a vinyl acetate resin, a polyethylene resin, a polyimide resin, or a polyester resin. The core portion 65a having the predetermined pattern P may be manufactured by a manufacturing technique of general screen printing using an emulsion. Therefore, a detailed description of the manufacturing method of the screen mask 62 is omitted.

In addition, the material of the core portion 65a may be a metal material such as stainless steel. In this case, the core portion 65a can be formed by attaching a metal sheet formed with the through portion 68 to the mesh portion 64. Further, the core portion 65a may have a laminated structure in which a resin layer and a metal layer are laminated.

The material of the sealing portion 65b is an elastic material softer than the material of the core portion 65 a. Specifically, as a material of the sealing portion 65b, a rubber material such as silicone rubber (PDMS) or Ethylene Propylene Diene Monomer (EPDM) is mentioned. However, the material of the seal portion 65b is not particularly limited as long as elastic deformation occurs when the electrolyte membrane 13 is pressed.

Thus, for example, the core portion 65a and the seal portion 65b may also be composed of a thermosetting resin or a rubber material. For example, the hardness of the sealing portion 65b and the hardness of the core portion 65a may be adjusted by changing the kind or the addition ratio of the curing agent of these materials. In addition, in the production of the screen mask, the hardness of the screen mask may be adjusted by setting the temperature conditions or the like under which the crosslinking reaction or the polymerization reaction occurs.

The hardness of the core portion 65a is preferably HS150 or more, more preferably HS200 or more in terms of shore a durometer. On the other hand, the hardness of the seal portion 65b is preferably HS90 or less, more preferably HS50 or less in terms of shore a durometer. In the case where the core portion 65a and the seal portion 65b are composed of a rubber material, a commercially available prescribed rubber durometer may be used to determine their hardness relationship.

A film forming method using the film forming apparatus 1 will be described with reference to fig. 4 to 6. First, as shown in fig. 6, the arrangement step S1 is performed. In this step, the substrate B and the mask structure 60 are placed on the stage 40. Specifically, the substrate B is accommodated in the 1 st recess 41 of the mounting table 40, and then the mask structure 60 is accommodated in the 2 nd recess 42. At this time, the alignment of the substrate B with respect to the anode 11 mounted on the housing 15 may be adjusted, and the temperature of the substrate B may be adjusted.

Next, a pressing step S2 is performed. In this step, first, the linear actuator 70 is driven to lower the storage body 15 from the state shown in fig. 1 to the state shown in fig. 4 toward the mask structure 60. Next, the pump 80 is driven. Thereby, the plating liquid L is supplied to the housing space 15a of the housing body 15. Since the pressure adjusting valve 54 is provided in the liquid discharge pipe 52, the liquid pressure of the plating liquid L in the storage space 15a is maintained at a predetermined pressure. As a result, as shown in fig. 4, the electrolyte membrane 13 is deformed by the hydraulic pressure into the internal space 69 of the frame body 61, and the mask structure 60 can be sandwiched between the electrolyte membrane 13 and the base material B. Further, the mask structure 60 may be pressed by the electrolyte membrane 13 to which the hydraulic pressure of the plating liquid L acts. By this pressing, the sealing portion 65B of the mask portion 65 is brought into contact with the surface of the base material B in an elastically deformed state. As a result, the screen mask 62 can be brought into close contact with the substrate B.

On the other hand, by the pressing of the electrolyte membrane 13, the permeate (plating solution) La oozed out from the electrolyte membrane 13 swelled by the plating solution L is filled into the through portions 68 of the screen mask 62. By the pressing of the electrolyte membrane 13, the filled permeate La is pressurized. As described above, the sealing portion 65B of the mask portion 65 is in contact with the surface of the base material B in an elastically deformed state. Further, the core portion 65a is fixed to the mesh portion 64 with higher rigidity than the seal portion 65 b. Therefore, the shape of the through portion 68 can be maintained regardless of the pressing of the electrolyte membrane 13. Since the penetrating portion 68 has a shape corresponding to the predetermined pattern P, the metal coating film F of the predetermined pattern can be formed on the surface of the base material B by electrolytic plating.

Next, a film forming step S3 is performed. In this step, the metal film F is formed while maintaining the pressed state of the electrolyte membrane 13 in the pressing step S2. Specifically, a voltage is applied between the anode 11 and the substrate B. As a result, the metal ions contained in the electrolyte membrane 13 move to the surface of the substrate B through the permeate La, and the metal ions are reduced on the surface of the substrate B. Since the permeate La filled in the through portion 68 is sealed inside the through portion 68 by the electrolyte membrane 13, a metal coating film F (see fig. 2) of a predetermined pattern can be formed on the surface of the base material B. Further, by pressing the electrolyte membrane 13, the permeate La is uniformly pressurized, and therefore, a uniform metal film F can be formed. In the case of manufacturing a wiring by the metal film F, the conductive underlayer formed on the surface of the insulating substrate B may be etched.

< Modification >

Fig. 7A to 7D are partial cross-sectional views of mask structures of film forming apparatuses according to modifications 1 to 4. These modifications differ from the embodiment shown in fig. 3A in the form of the mask portion. Therefore, the differences from the above embodiments will be described, and the detailed description thereof will be omitted.

For example, as shown in fig. 7A, in modification 1, the seal portion 65b may extend along a side wall surface 65e of the core portion 65a forming the through portion 68. Thereby, the core portion 65a is covered with the seal portion 65 b. Therefore, at the time of film formation, the core portion 65a can be restrained from coming into contact with the exudate La filled into the through portion 68. As a result, deterioration and damage of the core portion 65a can be suppressed, and rigidity of the mask portion 65 can be maintained. Further, the corner portions of the ridge lines 65f including the core portion 65a can be protected with the seal portion 65 b. For example, the sealing portion 65B is formed by impregnating the core portion 65a in a material having fluidity (for example, a material 6B of fig. 8B) which becomes the sealing portion 65B, and curing the material.

As shown in fig. 7B to 7D, in modification examples 2 to 4, the core portion 65a has an opposing surface 65c opposing the base material B and a side wall surface 65e forming the through portion 68. The seal portion 65b is formed along a ridge line 65f formed by the opposing face 65c and the side wall face 65e. In these figures, the ridge 65f extends in a direction perpendicular to the paper surface. Here, the ridge line 65f is an opening edge of the penetration portion 68 formed by the core portion 65 a. The opening edge is the opening edge on the opposite side of the substrate B side (mesh portion 64).

According to these modifications, the seal portion 65b is formed locally along the ridge line 65f of the core portion 65 a. That is, the opposite face 65c of the core portion 65a is exposed from the seal portion 65 b. By pressing the electrolyte membrane 13, the compression deformability of the seal portion 65b can be improved. As a result, the metal film F can be formed in a pattern with higher accuracy.

Here, in modification 2 shown in fig. 7B, the seal portion 65B is formed in an edge region along the ridge line 65f among the opposing faces 65c of the core portion 65 a. In the central region of the other facing surface 65c, the facing surface 65c is exposed from the seal portion 65 b. By providing the seal portion 65b locally on the opposing surface 65c, the compression deformability of the seal portion 65b can be improved.

The sealing portion 65B shown in fig. 7B may be manufactured as shown in fig. 8A. The sheet 6A corresponding to the seal portion 65b is brought into contact with the opposite face 65c of the core portion 65a (refer to the upper view of fig. 8A). In this state, the sheet 6A is irradiated with the laser beam G1 along the edge region of the ridge line 65f of the core portion 65a, and the sheet 6A and the core portion 65a are partially welded (see the central view of fig. 8A). Then, when the sheet 6A is removed, a seal portion 65B shown in fig. 7B can be obtained (see fig. 8A lower view).

In modification 3 shown in fig. 7C, a concave portion 65g is formed along an edge region of the ridge line 65f in the opposing surface 65C of the core portion 65 a. The seal portion 65B enters the recess 65g and protrudes toward the base material B side than the exposed facing surface 65 c. In modification 3, the compression deformability of the seal portion 65B can be further improved by increasing the thickness of the seal portion 65B as compared with fig. 7B. In addition, the sealing portion 65b is fitted with the core portion 65a by the sealing portion 65b entering the recess portion 65g. Thereby, the sealing portion 65b can be mechanically restrained on the core portion 65 a.

The sealing portion 65B shown in fig. 7C may be manufactured as shown in fig. 8B. The melted rubber or resin material 6B corresponding to the seal portion 65B is brought into contact with the opposite face 65c of the core portion 65a (see fig. 8B upper view). Specifically, the core portion 65a is brought into contact with the material 6B until the material 6B enters the position of the recess 65 g. Then, the core portion 65a is lifted from the material 6B, and the material 6B is cured to form a portion 6C including the seal portion 65B (refer to a central view of fig. 8B). The laser beam G2 is irradiated to the region other than the edge region along the ridge line 65f of the core portion 65a, and the resin is removed. Thereby, the sealing portion 65B shown in fig. 7C (see the lower view of fig. 8B) can be obtained.

In modification 4 shown in fig. 7D, a seal portion 65b is formed in an edge region along a ridge line 65f among the opposing faces 65c of the core portion 65 a. In the central region of the other facing surface 65c, the facing surface 65c is exposed from the seal portion 65 b. Further, the seal portion 65b also extends to a side wall face 65e of the core portion 65 a. By providing the seal portion 65b locally on the opposing surface 65c, the compression deformability of the seal portion 65b can be improved. Further, the corner portions of the ridge lines 65f including the core portion 65a can be protected with the seal portion 65 b.

The sealing portion 65b shown in fig. 7D may be manufactured as shown in fig. 8C. The melted rubber or resin material 6B corresponding to the seal portion 65B is brought into contact with the opposite face 65C of the core portion 65a (see fig. 8C upper view). Then, the core portion 65a is lifted from the material 6B, and the material 6B is cured to form a portion 6D including the seal portion 65B (refer to a central view of fig. 8C). The laser beam G2 is irradiated to the region other than the edge region along the ridge line 65f of the core portion 65a, and the resin is removed. Thereby, the sealing portion 65b shown in fig. 7D (see fig. 8C lower view) can be obtained.

Fig. 9A and 9B are partial cross-sectional views of mask structures of film forming apparatuses according to modification 5 and modification 6. These modifications are different from the embodiment shown in fig. 3A in the form of mask portions. Therefore, the differences from the above embodiments will be described, and the detailed description thereof will be omitted.

In modification 5 and modification 6, the hardness of the mask portion 65 gradually increases as it progresses from the seal portion 65b toward the core portion 65 a. In the case of repeatedly using the mask structure 60, the seal portion 65b is repeatedly elastically deformed. Thereby, the sealing portion 65b and the core portion 65a are easily separated at their interfaces. However, according to these examples, the hardness difference between the hardness of the seal portion 65b and the hardness of the core portion 65a is suppressed from locally becoming large. As a result, separation of the core portion 65a and the seal portion 65b can be prevented.

In modification 5 shown in fig. 9A, a seal portion 65B is formed only on the side in contact with the base material B, and the hardness of the mask portion 65 gradually varies along the thickness direction of the mask portion 65. Specifically, the mask portion 65 gradually becomes larger as advancing from the sealing portion 65b side toward the core portion 65a on the mesh portion 64 side. In modification 5, a portion of the mask portion 65 that is compressively and elastically deformed by the pressing of the electrolyte membrane 13 is a seal portion 65b. The other part is the core part 65a. The hardness of the mask portion 65 may be changed as follows. Specifically, in manufacturing the mask portion 65, a heater is used, and the degree of the crosslinking reaction or the polymerization reaction of the resin material or the rubber material is changed by heating to impart a temperature gradient in the thickness direction.

In modification 6 shown in fig. 9B, a seal portion 65B is formed so as to surround the core portion 65 a. That is, in modification 6, unlike modification 5, the seal portion 65b extends to the side wall surface 65e forming the through portion 68. Thereby, the exposure of the core portion 65a can be suppressed. The hardness of the mask portion 65 may be changed as follows. Specifically, when the mask portion 65 is manufactured, the degree of the crosslinking reaction or the polymerization reaction of the resin material or the rubber material is changed by heating by applying a temperature gradient from the center to the periphery using microwaves.

Examples

The invention is illustrated by the following examples.

Examples (example)

As a base material for film formation, a glass epoxy substrate in which a member formed by overlapping glass fiber cloths is impregnated with an epoxy resin is prepared. A copper foil is formed on the surface of the glass epoxy substrate. Next, a copper film was formed using the film forming apparatus of the embodiment shown in fig. 1. Mask structure a mask structure shown in fig. 9B was prepared. Specifically, the a-type shore hardness of the seal portion is adjusted to HS40 by swelling the surface of the mask portion. Further, the A-Shore hardness of the core portion was HS600. As a plating solution, an aqueous copper sulfate solution (Cu-BRITE-SED) manufactured by JCU, inc. was used, and a Cu plate was used as an anode. The electrolyte membrane used was Nafion (registered trademark) from dupont. As a film forming condition, a copper film was formed at a temperature of 42℃in the plating solution, a hydraulic pressure of the electrolyte solution of 1MPa, a current density of 7A/dm ² and a film forming time of 500 seconds.

Comparative example 1

A copper film was formed in the same manner as in example. The difference from the examples is that polyethylene terephthalate (PET) having a thickness of 100 μm was used for the mask portion of the mask structure.

Comparative example 2

A copper film was formed in the same manner as in example. The difference from the examples is that a 100 μm thick silicone rubber of the Shore A hardness HS50 was used for the mask portion of the mask structure.

In examples after film formation and comparative examples 1 and 2, the shape of the metal film after film formation was confirmed. In comparative example 1, it was confirmed that the plating solution (effusion) intruded between the mask portion and the substrate. In examples and comparative example 2, there was no such phenomenon. This is because the mask portion of comparative example 1 is hard, and the adhesion between the mask portion and the substrate is insufficient.

On the other hand, the pressed structure analysis of the electrolyte membrane was performed for the mask portions of examples and comparative examples 1 and 2. It is found that the mask portion of comparative example 2 was greatly deformed, and the cross-sectional area of the through portion was reduced by about 5% after pressing. Furthermore, the samples of example and comparative example 1 were hardly changed before and after pressing.

From these results, it can be said that a metal film having a desired pattern and a desired cross-sectional shape can be formed by providing a core portion in the mask portion and providing a seal portion which is made of an elastic material softer than the core portion and is in contact with the base material.

While the preferred embodiments of the present invention have been described above, the present invention is not limited to the film forming apparatus of the above embodiments, and includes all aspects included in the concept of the present invention and the scope of patent claims. In order to achieve the above-described problems and effects, the respective structures may be appropriately selected and combined. For example, the shape, material, arrangement, size, and the like of each constituent element in the above embodiment may be appropriately changed according to the specific embodiment of the present invention.

Claims

1. A metal film forming apparatus for forming a metal film of a predetermined pattern on a substrate by electrolytic plating in a state in which a mask structure is sandwiched between an electrolyte membrane and the substrate,

The film forming apparatus includes a pressing mechanism that presses the mask structure with the electrolyte membrane by a hydraulic pressure of a plating solution,

The mask structure is provided with a screen mask formed with through portions of the predetermined pattern,

The screen mask includes a mesh portion having openings formed in a lattice shape and a mask portion fixed to the mesh portion on the substrate side and having the through portions formed,

The mask portion has a core portion that maintains the shape of the mask portion and a seal portion that is composed of an elastic material softer than the core portion and is in contact with the base material.

2. The apparatus for forming a metal film according to claim 1,

The seal portion extends along a side wall surface forming the through portion.

3. The apparatus for forming a metal film according to claim 1,

The core portion has: an opposing surface opposing the base material, and a side wall surface forming the through portion,

The seal portion is formed along a ridge line formed by the opposite face and the side wall face.

4. The apparatus for forming a metal film according to claim 1,

The hardness of the mask portion gradually becomes larger as it progresses from the sealing portion toward the core portion.