JP7764838B2 - Film forming equipment - Google Patents

Description

The present invention relates to a film formation device, and in particular to a film formation device suitable for solid-phase electrodeposition.

A known film-forming device suitable for solid-phase electrodeposition, as described in Patent Document 1 below, includes an electrolyte membrane placed between an anode and a substrate (which serves as a cathode), a container that houses the anode and plating solution and has an opening facing the substrate covered with the electrolyte membrane, and a power supply unit that applies a voltage between the anode and the substrate; the application of voltage forms a metal film derived from metal ions in the plating solution on the surface of the substrate.

JP 2016-169399 A

However, with the above-mentioned membrane formation device, if the area of the electrolyte membrane is constant, it is not possible to simultaneously form membranes on multiple substrates, making it difficult to improve productivity. On the other hand, if the area of the electrolyte membrane is increased, a new problem arises: it becomes difficult to ensure uniform contact between the electrolyte membrane and the substrate during membrane formation. In other words, there are limitations to expanding the area of the electrolyte membrane.

The present invention was made to solve these technical problems, and aims to provide a film formation apparatus that can improve productivity.

The film formation device of the present invention comprises a plate-shaped anode, an electrolyte membrane disposed between the anode and a substrate serving as a cathode, a container for containing a plating solution, and a power supply unit for applying a voltage between the anode and the substrate. With the electrolyte membrane in contact with the substrate, the voltage is applied to form a metal film derived from metal ions in the plating solution on the surface of the substrate. The film formation device is characterized by having at least one first unit consisting of the anode and a pair of electrolyte membranes disposed on either side of the anode so as to sandwich the anode.

The film formation apparatus of the present invention has at least one first unit consisting of an anode and a pair of electrolyte membranes arranged on either side of the anode, sandwiching the anode. This allows two substrates to be placed on either side of the first unit, sandwiching the anode. This makes it possible to utilize both sides of the anode and simultaneously perform single-sided film formation on two substrates. As a result, production volume per unit time can be doubled, enabling improved productivity.

In the film forming apparatus according to the present invention, a second unit consisting of the anode and the electrolyte membrane disposed on one side of the anode is preferably provided on each side of the first unit, and the second unit is preferably disposed opposite the first unit so that its electrolyte membrane is adjacent to the electrolyte membrane of the first unit. In this way, a substrate can be disposed between the electrolyte membrane of the second unit and the electrolyte membrane of the first unit, i.e., electrolyte membranes can be disposed on both sides of the substrate. As a result, it becomes possible to simultaneously form films on both sides of multiple substrates, further improving productivity.

In the film forming apparatus according to the present invention, it is preferable that there are multiple first units, stacked between a pair of the second units. In this way, a substrate can be placed between the electrolyte membranes of adjacent first units, i.e., electrolyte membranes can be placed on both sides of the substrate. This further increases the number of substrates that can be simultaneously subjected to double-sided film formation, which is expected to significantly improve productivity.

This invention can improve productivity.

1 is a schematic cross-sectional view showing a film forming apparatus according to a first embodiment. FIG. 2 is a schematic cross-sectional view showing the container in an open state. FIG. 10 is a schematic cross-sectional view showing a film forming apparatus according to a second embodiment. FIG. 2 is a schematic cross-sectional view showing the container in an open state. FIG. 10 is a schematic cross-sectional view showing how a substrate is placed by a conveying fork. FIG. 2 is a schematic cross-sectional view showing a state in which a substrate is arranged. FIG. 2 is a schematic cross-sectional view showing a state in which the container is closed.

Embodiments of a film deposition apparatus according to the present invention will be described below with reference to the drawings. In the description of the drawings, identical elements will be assigned the same reference numerals, and duplicate explanations will be omitted. Furthermore, in the following description, the up/down and left/right directions are merely directions for convenience that correspond to the state shown in the drawings, and do not limit the position or arrangement of the film deposition apparatus.

[First embodiment]
1 , the film formation apparatus 1 of this embodiment is a plating apparatus for forming (in other words, coating) a metal film on the surface of a substrate 12 by using a solid-phase electrodeposition method. The film formation apparatus 1 includes a plate-shaped anode 11, an electrolyte membrane 13 disposed between the anode 11 and the substrate 12, a container 14 for containing the substrate 12 and a plating solution S, etc., and a power supply unit 15 for applying a voltage between the anode 11 and the substrate 12.

The anode 11 is formed into a flat plate from a metal material and is installed inside the container 14 so that both its upper and lower surfaces can come into contact with the plating solution S filled inside the container 14. More specifically, the anode 11 is installed horizontally across the center of the container 14 via an electrode support 16 so that both its upper and lower surfaces can come into contact with the plating solution S filled inside the container 14. The electrode support 16 is formed from a metal material that is insoluble in the plating solution S and has a conductive property, and has a fixed end that is fixed to the peripheral wall of the container 14 and a holding end that holds the peripheral edge of the electrolyte membrane 13. The electrode support 16 is also formed in a mesh shape or with multiple through holes to allow the plating solution S filled inside the container 14 to move up and down.

The electrode support 16 is electrically connected to the positive electrode of the power supply unit 15 via a conductor. Therefore, the anode 11 supported by the electrode support 16 is electrically connected to the positive electrode of the power supply unit 15 via the electrode support 16 and the conductor. The anode 11 may be either a soluble anode made of the same material (e.g., copper) as the metal coating formed on the substrate 12, or an anode made of a material (e.g., titanium) that is insoluble in the plating solution S.

The electrolyte membrane 13 is a so-called solid electrolyte membrane and has a certain degree of flexibility. When the electrolyte membrane 13 comes into contact with the plating solution S contained in the container 14, it becomes impregnated (contains) the metal ions contained in the plating solution S. When a voltage is applied, metal derived from the metal ions is deposited on the surface of the cathode (substrate 12) in contact with the electrolyte membrane 13.

The thickness of the electrolyte membrane 13 is, for example, 5 to 200 μm. Examples of materials for the electrolyte membrane 13 include fluorine-based resins such as DuPont's Nafion (registered trademark), hydrocarbon-based resins, polyamic acid resins, and resins with ion exchange properties such as AGC's Selemion (CMV, CMD, CMF series).

As shown in FIG. 1, this embodiment uses two electrolyte membranes 13. These two electrolyte membranes 13 are arranged above and below the anode 11, sandwiching the anode 11 therebetween. More specifically, of the two electrolyte membranes 13, the upper electrolyte membrane 13 arranged above the anode 11 is attached to the container 14 facing the anode 11 so as to form a space between the anode 11 and the upper electrolyte membrane 13 for containing the plating solution S. Similarly, the lower electrolyte membrane 13 arranged below the anode 11 is attached to the container 14 facing the anode 11 so as to form a space between the anode 11 and the lower electrolyte membrane 13 for containing the plating solution S.

The anode 11 and a pair of electrolyte membranes 13 (i.e., the upper electrolyte membrane 13 and the lower electrolyte membrane 13) arranged on either side of the anode 11 constitute a first unit 10. The film forming apparatus 1 of this embodiment has one such first unit 10.

The substrate 12 is, for example, a plate-shaped member. The substrate 12 may be made of a metal material such as copper, silver, gold, nickel, aluminum, or iron, or may be made of a resin, ceramic, or the like, whose surface is coated with a metal layer made of one of the above metals. In this embodiment, there are two substrates 12. One of them (the upper substrate 12) is positioned above the upper electrolyte membrane 13 in contact with the upper electrolyte membrane 13, and the other (the lower substrate 12) is positioned below the lower electrolyte membrane 13 in contact with the lower electrolyte membrane 13.

The upper substrate 12 is held by a substrate holder 17 attached to the top plate of the housing 14. More specifically, the upper substrate 12 is fixed to the substrate holder 17 by, for example, vacuum suction, and is electrically connected to the negative electrode of the power supply unit 15 via the substrate holder 17 and a conductor. The lower substrate 12 is held by a substrate holder 17 attached to the bottom plate of the housing 14. More specifically, the lower substrate 12 is fixed to the substrate holder 17 by, for example, vacuum suction, and is electrically connected to the negative electrode of the power supply unit 15 via the substrate holder 17 and a conductor.

The substrate holder 17 is formed, for example, in the shape of a flat plate made of a conductive material. Methods for holding the substrate 12 with the substrate holder 17 include the aforementioned vacuum suction, as well as a method in which the peripheral edge of the substrate 12 is clamped using two frames that can be separated vertically. The substrate holder 17 attached to the top plate of the housing 14 and the substrate holder 17 attached to the bottom plate of the housing 14 are connected in parallel to the power supply unit 15 via electrical leads.

The container 14 is made of a material insoluble in the plating solution and includes a lower container 141, an intermediate container 142, and an upper container 143. As shown in FIG. 2, the lower container 141 is, for example, a cylindrical container with a bottom, and contains a substrate holder 17 attached to the bottom plate of the container 14 and a lower substrate 12 held by the substrate holder 17. The upper container 143 is, for example, a cylindrical container with a top, and contains a substrate holder 17 attached to the top plate of the container 14 and an upper substrate 12 held by the substrate holder 17.

The intermediate container 142 is positioned between the lower container 141 and the upper container 143, is cylindrical, and contains the anode 11, two electrolyte membranes 13, and plating solution S. The anode 11 is horizontally supported in the center of the intermediate container 142 via an electrode support 16. The upper electrolyte membrane 13 is attached to the upper end of the intermediate container 142 so as to close the upper opening of the intermediate container 142. The lower electrolyte membrane 13 is attached to the lower end of the intermediate container 142 so as to close the lower opening of the intermediate container 142.

The intermediate container 142 is also provided with a supply port 142a through which the plating solution S is supplied and a discharge port 142b through which the plating solution S is discharged. In the vertical direction, the supply port 142a is located below the anode 11 disposed in the intermediate container 142, and the discharge port 142b is located above the anode 11. The supply port 142a and the discharge port 142b are connected to a tank (not shown) via piping. The plating solution S delivered from the tank by a liquid supply pump (not shown) flows into the container 14 through the supply port 142a, passes through the electrode support 16 having a mesh or multiple through-holes, is discharged through the discharge port 142b, and returns to the tank. A pressure adjustment valve (not shown) is preferably further provided downstream of the discharge port 142b. This allows the plating solution S in the container 14 to be pressurized to a predetermined pressure using the pressure adjustment valve and the liquid supply pump.

The lower housing 141, intermediate housing 142, and upper housing 143 are each configured so that they can be raised and lowered by an elevator device. The elevator device may be any device that can raise and lower the lower housing 141, intermediate housing 142, and upper housing 143, and may be configured, for example, with a hydraulic or pneumatic cylinder, an electric actuator, a linear guide and motor, an extendable structure, etc.

In this embodiment, the lifting device is a linear guide having, for example, a pair of guide rails 18 erected on both the left and right sides of the housing body 14, and multiple slide blocks 19 through which the guide rails 18 are inserted and which are slidable along the guide rails 18. The slide blocks 19 are arranged on the left and right sides of the lower housing body 141, the intermediate housing body 142, and the upper housing body 143, respectively, and are fixed to the outer walls of the lower housing body 141, the intermediate housing body 142, and the upper housing body 143.

By using a linear guide with this structure, the lower container 141, the intermediate container 142, and the upper container 143 can each be raised and lowered. For example, after a film has been formed and the plating solution S has been discharged from the container 14, the upper container 143 and the intermediate container 142 can be raised and lowered in sequence to separate the lower container 141, the intermediate container 142, and the upper container 143, respectively, and open the container 14 (see Figure 2). Therefore, the substrates 12 on which the film has been formed can each be removed, and new substrates 12 (i.e., the substrates 12 on which the film is to be formed) can be installed.

When opening the housing 14, the lower housing 141, intermediate housing 142, and upper housing 143 can be separated by, for example, lowering the lower housing 141 and raising the upper housing 143 without moving the intermediate housing 142. Furthermore, the lower housing 141, intermediate housing 142, and upper housing 143 can be separated by sequentially lowering the lower housing 141 and intermediate housing 142 without moving the upper housing 143.

The film forming apparatus 1 of this embodiment has a first unit 10 consisting of an anode 11 and a pair of electrolyte membranes 13 arranged on either side of the anode 11, sandwiching the anode 11. By placing two substrates 12 on the top and bottom of the first unit 10, sandwiching the first unit 10, it is possible to utilize both sides of the anode 11 and simultaneously form a film on one side of the two substrates 12. This doubles the production volume per unit time, thereby improving productivity.

The following briefly describes the film formation method using the film formation apparatus 1 of this embodiment.

First, the lower housing 141, intermediate housing 142, and upper housing 143 are separated from each other using a lifting device having guide rails 18 and slide blocks 19, thereby opening the housing 14. Next, the substrate 12 is fixed to the substrate holder 17 of the lower housing 141 and the substrate holder 17 of the upper housing 143, respectively. Next, the lower housing 141, intermediate housing 142, and upper housing 143 are brought closer together using a lifting device having guide rails 18 and slide blocks 19, thereby closing the housing 14. When the housing 14 is closed, the upper electrolyte membrane 13 comes into contact with the lower surface of the upper substrate 12, and the lower electrolyte membrane 13 comes into contact with the upper surface of the lower substrate 12.

Then, the liquid feed pump is driven to send the plating solution S stored in the tank to the container 14. As a result, the plating solution S stored in the tank flows into the intermediate container 142 through the supply port 142a of the intermediate container 142. Then, under the liquid pressure of the plating solution S, the upper electrolyte membrane 13 presses against the upper substrate 12, and the lower electrolyte membrane 13 presses against the lower substrate 12.

Next, a voltage is applied between the anode 11 and the cathode substrate 12 using the power supply unit 15. When the voltage is applied, metal derived from metal ions precipitates from the electrolyte membrane 13, and a metal film is formed on the lower surface of the upper substrate 12 and the upper surface of the lower substrate 12. When a metal film of the desired thickness has been formed, the voltage application is terminated, compressed air is supplied into the intermediate container 142 through the outlet 142b, and the plating solution S contained in the intermediate container 142 is discharged through the supply port 142a.

Next, the container 14 is opened as described above, and the substrate 12 after film formation is removed. If double-sided film formation is required, the removed substrate 12 is inverted and fixed to the substrate holder 17; if double-sided film formation is not required, a new substrate 12 is fixed to the substrate holder 17. The above procedure is then repeated.

Second Embodiment
A second embodiment of the film forming apparatus will be described below with reference to Figures 3 to 7. The film forming apparatus 1A of this embodiment differs from the first embodiment described above in that a plurality of (three) first units 10 are stacked, and that second units 20 are further disposed on both sides of the stacked plurality of first units 10. Only these differences will be described below.

As shown in FIG. 3, the film forming apparatus 1A of this embodiment includes three first units 10 stacked vertically, and second units 20 arranged above and below each of the three stacked first units 10. The second units 20 each include an anode 11 and an electrolyte membrane 13 arranged on one side of the anode 11.

More specifically, the housing 14A of the film forming apparatus 1A has three intermediate housings 142 stacked vertically, a lower housing 144 arranged below the three intermediate housings 142, and an upper housing 145 arranged above the three intermediate housings 142. As shown in FIG. 4 , the lower housing 144 is, for example, cylindrical and contains the anode 11, electrolyte membrane 13, and plating solution S. The anode 11 is suspended horizontally from the center of the lower housing 144 via an electrode support 16. The electrolyte membrane 13 is arranged above the anode 11 and is attached to the upper end of the lower housing 144 so as to close the opening of the lower housing 144.

The anode 11 and electrolyte membrane 13 constitute the second unit 20. Here, the second unit 20 is positioned opposite the first unit 10 so that the electrolyte membrane 13 constituting the second unit 20 is adjacent to the electrolyte membrane 13 of the first unit 10.

The lower container 144 is also provided with a supply port 144a through which the plating solution S is supplied and a discharge port 144b through which the plating solution S is discharged. In the vertical direction, the supply port 144a is located below the anode 11 disposed in the lower container 144, and the discharge port 144b is located above the anode 11. The supply port 144a and the discharge port 144b are connected to the tank described above via piping.

The upper housing 145 is, for example, cylindrical and contains the anode 11, electrolyte membrane 13, and plating solution S. The anode 11 is suspended across the center of the upper housing 145 via an electrode support 16. The electrolyte membrane 13 is disposed below the anode 11 and is attached to the lower end of the upper housing 145 so as to cover the opening of the upper housing 145. Similarly, the anode 11 and electrolyte membrane 13 constitute the second unit 20. The second unit 20 is disposed opposite the first unit 10 so that the electrolyte membrane 13 constituting the second unit 20 is adjacent to the electrolyte membrane 13 of the first unit 10.

The upper container 145 is also provided with a supply port 145a through which the plating solution S is supplied and a discharge port 145b through which the plating solution S is discharged. In the vertical direction, the supply port 145a is located below the anode 11 arranged in the upper container 145, and the discharge port 145b is located above the anode 11. The supply port 145a and the discharge port 145b are connected to the tank described above via piping.

In this embodiment, the tank and liquid supply pump may be integrated into one unit, or one may be provided for each of the intermediate container 142, the lower container 144, and the upper container 145.

In addition, in this embodiment, each of the intermediate storage units 142, lower storage unit 144, and upper storage unit 145 is configured so that it can be raised and lowered by a lifting device having a guide rail 18 and a slide block 19.

In the film forming apparatus 1A of this embodiment, from top to bottom, a second unit 20, three stacked first units 10, and another second unit 20 are arranged in this order. That is, three first units 10 are stacked between a pair of second units 20. Furthermore, each second unit 20 is arranged facing the first unit 10 so that the electrolyte membrane 13 constituting that unit is adjacent to the electrolyte membrane 13 of the first unit 10. Therefore, substrates 12 can be arranged between the electrolyte membrane 13 of the second unit 20 and the electrolyte membrane 13 of the first unit 10, and between the electrolyte membranes 13 of adjacent first units 10. In other words, electrolyte membranes 13 can be arranged on both the top and bottom surfaces of the substrate 12. This allows simultaneous double-sided film formation on multiple (here, four) substrates 12, further significantly improving productivity.

As shown in FIG. 3, in the film forming apparatus 1A of this embodiment, the five anodes 11 are connected in parallel to the positive pole of the power supply unit 15 via their respective electrode supports 16 and conductors, and the four substrates 12 are connected in parallel to the negative pole of the power supply unit 15 via conductors.

The following briefly describes the film formation method using the film formation apparatus 1A of this embodiment.

First, the upper storage unit 145, the intermediate storage units 142, and the lower storage unit 144 are separated from each other using a lifting device having guide rails 18 and slide blocks 19, thereby opening the storage unit 14A (see Figure 4).

Next, as shown in FIG. 5, the substrate 12 is removed from the substrate storage rack (not shown) using a transport fork 30 and transported to the film formation apparatus 1A. The transport fork 30 has multiple (four in this case) arms 31 extending in the same direction. Methods for removing the substrate 12 from the substrate storage rack include, for example, contact and non-contact methods of lifting the substrate 12. In the case of a contact method, for example, a vacuum pad is attached to the tip of the arm 31, and the substrate 12 is lifted by the vacuum pad. In the case of a non-contact method, for example, a Bernoulli chuck is attached to the tip of the arm 31, and the substrate 12 is lifted by the Bernoulli chuck.

As shown in FIG. 6, the substrate 12 transported by the transport fork 30 is placed on the upper surface of the upper electrolyte membrane 13 of each first unit 10 and on the upper surface of the electrolyte membrane 13 housed in the lower housing 144 so that both the upper and lower surfaces of the substrate 12 come into contact with the electrolyte membrane 13 when the housing 14A is closed. Next, an elevator device having guide rails 18 and slide blocks 19 is used to bring the lower housing 144, each intermediate housing 142, and the upper housing 145 closer together to close the housing 14A. When the housing 14A is closed, both the upper and lower surfaces of each substrate 12 come into contact with the electrolyte membrane 13 (see FIG. 7).

Then, the liquid supply pump is driven to send the plating solution S stored in the tank to the container 14A. As a result, the plating solution S stored in the tank flows into the intermediate container 142, the lower container 144, and the upper container 145 through the supply ports 142a, 144a, and 145a. Then, under the liquid pressure of the plating solution S, each electrolyte membrane 13 presses against the substrate 12.

Next, a voltage is applied between the anode 11 and the substrate 12, which serves as the cathode, using the power supply 15. When the voltage is applied, metal derived from the metal ions precipitates from the electrolyte membrane 13, forming a metal coating on the surface of the substrate 12. At this time, the top and bottom surfaces of the substrate 12 are in contact with the electrolyte membrane 13, so metal coatings are simultaneously formed on the top and bottom surfaces of the substrate 12.

When a metal film of the desired thickness has been formed, the voltage application is terminated. Next, compressed air is supplied from outlets 142b, 144b, and 145b into the intermediate container 142, lower container 144, and upper container 145, and the plating solution S contained in the intermediate container 142, lower container 144, and upper container 145 is discharged from supply ports 142a, 144a, and 145a.

Next, the container 14A is opened as described above, the substrate 12 with the film formed on both sides is removed, and a new substrate 12 is transported and placed using the transport fork 30. The above procedure is then repeated.

In this embodiment, an example has been described in which three first units 10 are stacked between a pair of second units 20, but this is not limiting and the number of first units 10 may be increased or decreased as appropriate. Furthermore, if the number of stacked first units 10 is increased, the number of substrates 12 that can be simultaneously subjected to double-sided film formation can be further increased, which is expected to significantly improve productivity.

In addition, in the above-described first and second embodiments, examples have been described in which the anode 11 and the electrolyte membrane 13 are arranged to face each other in the vertical direction (i.e., a vertical arrangement), but the present invention also applies to examples in which the anode 11 and the electrolyte membrane 13 are arranged to face each other in the left-right direction (i.e., a horizontal arrangement). For example, multiple first units 10 may be stacked in the left-right direction, and second units 20 may be further arranged on both the left and right sides of the stacked multiple first units 10.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims.

1, 1A: Film forming apparatus, 10: First unit, 11: Anode, 12: Substrate, 13: Electrolyte membrane, 14, 14A: Housing, 15: Power supply unit, 16: Electrode support, 17: Substrate holder, 18: Guide rail, 19: Slide block, 20: Second unit, 30: Conveyor fork, 31: Arm, 141, 144: Lower housing, 142: Intermediate housing, 142a, 144a, 145a: Supply port, 142b, 144b, 145b: Discharge port, 143, 145: Upper housing

Claims (3)

A film formation device comprising: a plate-shaped anode; an electrolyte membrane disposed between the anode and a substrate serving as a cathode; a container for accommodating a plating solution; and a power supply unit for applying a voltage between the anode and the substrate, wherein, with the electrolyte membrane in contact with the substrate, a metal coating derived from metal ions in the plating solution is formed on a surface of the substrate by applying the voltage;
A film forming apparatus comprising at least one first unit including the anode and a pair of the electrolyte membranes disposed on either side of the anode so as to sandwich the anode. a second unit including the anode and the electrolyte membrane disposed on one side of the anode is provided on each side of the first unit;
2. The film forming apparatus according to claim 1, wherein the second unit is disposed opposite the first unit so that the electrolyte membrane of the second unit is adjacent to the electrolyte membrane of the first unit. The film forming apparatus of claim 2, wherein the first units are multiple and stacked between a pair of the second units.