Electroplating device and electroplating method

Abstract

The present invention relates to a plating apparatus and a plating method for plating at least one main surface of a rectangular substrate. The plating apparatus of the present invention is provided with: a holding unit for holding a substrate in a horizontal posture in which one main surface faces upward in a processing tank; a cathode electrode in contact with a peripheral edge portion of the one main surface of the substrate held by the holding portion; an anode electrode part disposed above the substrate held by the holding part, the lower surface of the anode electrode part being disposed so as to face the one main surface; and a power supply unit connected to the anode electrode unit and the cathode electrode. The anode electrode portion has a first electrode facing a central portion of the one main surface, and a second electrode further outward than the first electrode and facing the one main surface. The power supply unit has a plurality of current output units capable of independently setting an output current, and the first electrode and the second electrode are connected to the current output units that are different from each other.

Description

Technical Field

[0001] The present invention relates to an electroplating apparatus and an electroplating method for electroplating at least one main surface of a rectangular substrate, such as a printed wiring substrate or a glass substrate. Background Technology

[0002] The technology of forming a metal thin film on the surface of various substrates such as semiconductor substrates, printed wiring substrates, and glass substrates by electroplating is widely used. For example, Patent Document 1 discloses an electroplating apparatus for forming a metal coating on the surface of a semiconductor wafer, which is the substrate to be electroplated. This electroplating apparatus uses a tool provided with a cathode electrode to hold the substrate, and an anode electrode is arranged opposite to the substrate. A voltage is applied between the two electrodes to achieve electrolytic electroplating.

[0003] In this electroplating process, there is a tendency for the film thickness at the periphery to be greater than that at the center of the substrate, mainly due to uneven current distribution. In the aforementioned prior art, a shielding plate is provided in the current path between the anode electrode and the substrate to block the current flowing toward the periphery of the substrate, thereby achieving uniformity of the current density distribution on the substrate surface.

[0004] Existing technical documents: Patent documents Patent Document 1: Japanese Patent Application Publication No. 2013-166999 Summary of the Invention

[0005] The problem the invention aims to solve

[0006] In recent years, substrates have become increasingly larger, with some substrates even exceeding 1 meter in side length. Correspondingly, the shielding plates for such large substrates are also large. Furthermore, in large substrates, the current difference between the central and peripheral areas tends to increase, making the design of shielding plates to achieve uniform current distribution extremely difficult. Moreover, for example, in glass substrates used in display devices, several substrates with slightly different external dimensions are produced, making it practically difficult to prepare optimized shielding plates for each of these substrate sizes.

[0007] Therefore, a technology is required that can correct the current density difference between the central and peripheral portions of a large substrate, thereby achieving uniform current density distribution within the substrate surface. In particular, a technology capable of achieving uniform current density distribution for substrates of different sizes is desired.

[0008] means for solving problems

[0009] The present invention was made in view of the aforementioned problems, and its object is to provide an electroplating apparatus and an electroplating method that can uniformly distribute the current density even on large substrates, thereby obtaining an electroplated film with uniform film thickness.

[0010] One embodiment of the present invention is an electroplating apparatus for electroplating at least one main surface of a rectangular substrate; comprising: a processing tank for storing an electroplating solution; a holding portion for holding the substrate in a horizontal position with the main surface facing upward within the processing tank; a cathode electrode for contacting a peripheral portion of the main surface of the substrate held by the holding portion; an anode electrode portion disposed above the substrate held by the holding portion, with its lower surface facing the main surface; and a power supply portion connected to the anode electrode portion and the cathode electrode.

[0011] Here, the anode electrode section has: at least one first electrode facing a central portion of the main surface that is more inward than the peripheral portion; and at least one second electrode facing a portion of the main surface that is more outward than the central portion. The power supply section has a plurality of current output sections capable of independently setting and changing the output current, and the first electrode and the second electrode are connected to different current output sections.

[0012] Furthermore, another embodiment of the present invention is an electroplating method for electroplating at least one main surface of a rectangular substrate. It includes the following steps: holding the substrate in a horizontal position with the main surface facing upwards by a holding portion in a processing tank storing the electroplating solution; contacting a cathode electrode with a portion of the main surface of the substrate held by the holding portion, while simultaneously disposing an anode electrode portion facing upwards above the substrate; and outputting current from a power supply portion connected between the anode electrode portion and the cathode electrode.

[0013] Here, the anode electrode section has: at least one first electrode facing a central portion of the main surface that is more inward than the peripheral portion; and at least one second electrode facing a portion of the main surface that is more outward than the central portion. The power supply section outputs the current to the first electrode and the second electrode from each of the current output sections that can be independently set and changed and are different from each other.

[0014] In this invention, the anode electrode section has a first electrode facing the center of the substrate and a second electrode facing the substrate further outward than the first electrode. Furthermore, each of the first and second electrodes is connected to an independent current output section, and the output current of each current output section can be set independently.

[0015] This configuration allows for independent adjustment of the current density distribution at the center and the periphery of the substrate. Therefore, for example, if the current density at the periphery tends to be higher than at the center, the input current to the first electrode opposite the center can be increased. Conversely, the input current to the second electrode can be decreased. Thus, the difference in current density between the center and the periphery can be reduced, thereby achieving a more uniform current density distribution.

[0016] Furthermore, even when a predetermined voltage is applied between the first and second electrodes, the desired current distribution may not necessarily occur. To address this, in this invention, the current supplied to the electrodes is set, i.e., the power supply unit outputs a predetermined current, thus enabling direct control of the current distribution in each part of the substrate.

[0017] The effects of the invention

[0018] As described above, according to the present invention, by uniformizing the density distribution of the current flowing from the anode electrode toward the substrate, it is possible to make the thickness of the coating formed on a main surface of the substrate by electroplating uniform.

[0019] The above and other objects and novel features of the present invention will become more fully apparent when referring to the accompanying drawings and reading the following detailed description. However, the drawings are primarily for illustrative purposes and do not limit the scope of the invention. Attached Figure Description

[0020] Figure 1 A diagram showing a schematic configuration of one embodiment of the electroplating apparatus of the present invention.

[0021] Figure 2 A diagram showing the general structure of the electroplating processing section.

[0022] Figure 3A A diagram showing the general structure of the electroplating processing section.

[0023] Figure 3B A diagram showing the general structure of the electroplating processing section.

[0024] Figure 4A A diagram showing the general structure of the chuck mechanism.

[0025] Figure 4B A diagram showing the general structure of the chuck mechanism.

[0026] Figure 5 A diagram schematically showing the composition of the main parts of an anode electrode unit.

[0027] Figure 6A A diagram schematically showing the state of an isolation tank immersed in an electroplating tank.

[0028] Figure 6BA diagram schematically showing the state of an isolation tank immersed in an electroplating tank.

[0029] Figure 7 A perspective view showing the external appearance of the support mechanism for the isolation groove in the anode electrode unit.

[0030] Figure 8A A diagram schematically illustrating the supply and discharge of electroplating solution to the isolation tank.

[0031] Figure 8B A diagram schematically illustrating the supply and discharge of electroplating solution to the isolation tank.

[0032] Figure 9 A diagram illustrating the lifting and lowering motion of the isolation trough in more detail.

[0033] Figure 10 A diagram illustrating the lifting and lowering motion of the isolation trough in more detail.

[0034] Figure 11 A diagram illustrating the lifting and lowering motion of the isolation trough in more detail.

[0035] Figure 12 A diagram showing the lifting and lowering motion of the entire support mechanism.

[0036] Figure 13 A block diagram showing the electrical structure of the electroplating apparatus.

[0037] Figure 14 A flowchart illustrating the electroplating process.

[0038] Figure 15 A diagram that schematically illustrates the actions of each part.

[0039] Figure 16A A diagram showing a modified example of the anode electrode.

[0040] Figure 16B A diagram showing a modified example of the anode electrode.

[0041] Figure 16C A diagram showing a modified example of the anode electrode.

[0042] Figure 17A A diagram schematically illustrating a modified example of the support mechanism for the anode electrode unit.

[0043] Figure 17B A diagram schematically illustrating a modified example of the support mechanism for the anode electrode unit. Detailed Implementation

[0044] Hereinafter, specific embodiments of the electroplating apparatus of the present invention will be described.

[0045] Figure 1This diagram illustrates a schematic configuration of one embodiment of the electroplating apparatus of the present invention. The electroplating apparatus 1 is a device for forming a metal (e.g., gold) coating on at least one main surface of various substrates S (hereinafter simply referred to as "substrate") such as semiconductor substrates, printed wiring substrates, and glass substrates by electrolytic electroplating. For the purposes of the following description, ... Figure 1 The diagram shows the definition of an orthogonal XYZ coordinate system. Figure 1 This is a side view of the electroplating apparatus 1, which is horizontal and parallel to... Figure 1 Let the direction perpendicular to the paper be the X direction, and let the horizontal direction orthogonal to the X direction and along it be the X direction. Figure 1 The orientation of the paper is set to the Y direction. Furthermore, the vertical direction is set to the Z direction. Also, in each drawing, the dashed arrows indicate the direction of movement of each component.

[0046] The electroplating apparatus 1 has a configuration in which the following components are assembled into a housing 10 composed of a plurality of frame members. Furthermore, in Figure 1 In the following figures, to avoid making the drawings too cumbersome, descriptions of certain components are sometimes omitted. Specifically, the holding mechanism for holding the components, the cover for covering the components, the mechanism for mounting them to the housing 10, etc., which contribute relatively little to the establishment of the invention, or whose construction can be carried out by appropriate known techniques and are considered not to require special explanation, are sometimes omitted from the drawings.

[0047] Figure 1 This is a front view of the electroplating apparatus 1. The electroplating apparatus 1 is provided with a transport section 2 that transports a substrate S along the Y direction. The transport section 2 has a plurality of transport rollers 21 arranged along the Y direction. Each transport roller 21 is rotatably supported by a support mechanism (not shown) with the X direction as its axis. By rotating the transport rollers 21 using a drive mechanism (not shown), the transport section 2 transports the substrate S horizontally along the Y direction. The rectangular substrate S is transported with one of its four sides at the front end. Hereinafter, the transport path of the substrate S is indicated by the symbol P, and the transport direction is indicated by the symbol Dt.

[0048] The electroplating apparatus 1 further includes an infeed section 3, an electroplating treatment section 4, a rinsing treatment section 5, an outfeed section 6, a power supply section 7, and a control section 9. The infeed section 3, the electroplating treatment section 4, the rinsing treatment section 5, and the outfeed section 6 are arranged sequentially along the transport direction Dt (Y direction) of the transport section 2 for transporting the substrate. That is, in this electroplating apparatus 1, the substrate S is transported by the transport section 2 along the Y direction and undergoes the required treatment in each of the aforementioned treatment sections.

[0049] The receiving unit 3 receives and temporarily holds the unprocessed substrate S transported from the outside, and supplies the substrate S to the electroplating processing unit 4 at necessary times. The electroplating processing unit 4 is the processing body for performing the electroplating method of the present invention, and immerses the substrate S in an electroplating solution for electroplating processing. The structure and operation of the electroplating processing unit 4 will be described in detail below.

[0050] The rinsing treatment unit 5 includes a rinsing tank 51, a cylinder 52, and a rinsing liquid supply and discharge unit 59. The rinsing tank 51 has an internal space large enough to accommodate the substrate S, and can store the rinsing liquid in this internal space. An opening is provided on the Y-direction side of the rinsing tank 51 at the portion overlapping with the transport path P. Baffles 51a and 51b are provided in this opening and can be opened and closed freely.

[0051] A tank 52 is positioned below the rinsing tank 51 to receive rinsing liquid overflowing from the rinsing tank 51. A rinsing liquid supply and discharge unit 59 supplies rinsing liquid to the rinsing tank 51 as needed and discharges rinsing liquid from the rinsing tank 51. The rinsing treatment unit 5 performs rinsing treatment on the substrate S immersed in the electroplating solution in the electroplating treatment unit 4. Water can be used as the rinsing liquid, for example. The transport unit 6 temporarily holds the substrate S while it is being transported by an external transport device to a post-processing step after rinsing treatment.

[0052] The power supply unit 7 supplies the necessary power to each part of the device. The control unit 9 controls each part of the device configured as described above, causing the electroplating apparatus 1 to perform a predetermined process. The hardware configuration of the control unit 9 can, for example, be the same as that of a general computer device. That is, through the central processing unit (CPU) provided in the control unit 9... Figure 13 By executing a pre-prepared control program, the various processes described below can be achieved. Unless otherwise specified, each part of the device operates based on control commands from the control unit 9.

[0053] The electroplating processing unit 4 includes an electroplating tank 41, cylinders 42 and 44, a clamping head 40, a moving mechanism 43, an anode electrode unit 45, a cleaning mechanism 48, and an electroplating solution supply and discharge unit 49. The electroplating tank 41 can store electroplating solution in an internal space large enough to accommodate a substrate S. The cylinder 42 is disposed below the electroplating tank 41 to receive overflowing electroplating solution. The clamping head 40 is disposed above the electroplating tank 41 to hold the substrate S undergoing electroplating processing. The cylinder 44 is disposed adjacent to the cylinder 42 below the electroplating tank 41 on the (-Y) side. The cleaning mechanism 48 cleans the clamping head 40 using a suitable cleaning solution (e.g., water). For this purpose, the cleaning mechanism 48 includes a cleaning nozzle 481 disposed within the cylinder 44. Figure 2 The cleaning solution supply and discharge section 482 supplies cleaning solution to the cleaning nozzle 481. The electroplating solution supply and discharge section 49 supplies electroplating solution to the electroplating tank 41 as needed and discharges electroplating solution from the electroplating tank 41.

[0054] Figure 2 , Figure 3A and Figure 3B A diagram showing the general structure of the electroplating processing section. More specifically, Figure 2 This is a front view of the main part of the electroplating treatment section 4 viewed in the (-X) direction. Figure 3A and Figure 3B This is equivalent to viewing the side view of the electroplating treatment section 4 in the (+Y) direction. Furthermore, to avoid making the diagram cumbersome, in... Figure 2 and Figure 3A The illustration of the anode electrode unit 45 is omitted.

[0055] like Figure 1 and Figure 2 As shown, openings are provided on the (-Y) and (+Y) sides of the electroplating tank 41, where they overlap with the transport path P. Baffles 41a and 41b, which can be opened and closed freely, are provided at these openings. When the baffles 41a and 41b are open, the substrate S, transported by the transport unit 2 along the transport path P, can pass through the openings on the sides of the electroplating tank 41. Therefore, untreated substrates S can be transported into the electroplating tank 41, and treated substrates S can be transported out of the electroplating tank 41.

[0056] On the other hand, in the closed state, the opening on the side of the electroplating tank 41 is closed. At this time, the transport path P of the substrate S is blocked, but the electroplating solution exceeding the height of the opening can be stored inside the electroplating tank 41. After the substrate S is received in the electroplating tank 41 with the baffle 41a on the (-Y) side in the open state, the baffle 41a is closed, so that the internal space of the electroplating tank 41 is filled with the electroplating solution L. Therefore, the substrate S is immersed in the electroplating solution L for electroplating treatment. Afterwards, when the electroplating solution is discharged and the baffle 41b on the (+Y) side is opened, the liquid level of the electroplating solution L drops below the lower end of the opening, and the electroplated substrate S is moved out to the rinsing section 5. The operation of the baffles 41a and 41b can be opened and closed independently of each other, or they can be opened and closed together.

[0057] like Figure 3A As shown, a rotary motor 23 is connected to the rotation shaft 22 of the conveying roller 21. The rotary motor 23 rotates according to the control command from the control unit 9, thereby rotating the conveying roller 21 and conveying the substrate S along the Y direction. Furthermore, some rollers may also be driven rollers that are not connected to a drive source.

[0058] Moreover, such as Figure 3A As shown, two sets of clamping heads 40 are provided at each end of the substrate S housed in the electroplating tank 41 in the X direction. Figure 1 and Figure 2Only one group on the (+X) side is shown in the figure. The two groups of clamping heads 40 are arranged symmetrically with respect to the YZ plane, but have the same basic structure. That is, each clamping head 40 has at least one clamping mechanism 400, a support frame 430 for supporting the clamping mechanism 400, and a moving mechanism 43 for moving the support frame 430 in the Y direction.

[0059] The support frame 430 is supported by a moving mechanism 43 that allows free movement along the Y direction. The moving mechanism 43 is mounted on the upper frame 11, which is part of the frame members constituting the housing 10. More specifically, the moving mechanism 43 includes: a guide rail 431, which is fixed to the upper frame 11 above the electroplating treatment section 4 and extends along the Y direction; a slider 432, which engages with the guide rail 431; and a drive source (not shown) that moves the slider 432 along the guide rail 431 in the Y direction. As described, a suitable linear motion mechanism can be applied, such as a linear motor, a linear motion guide mechanism, a chain drive mechanism, or a belt drive mechanism. For example, a single-axis robot with such a drive mechanism pre-integrated can preferably be used.

[0060] A support frame 430 is attached to the lower end of the slider 432, and the clamping mechanism 400 is fixed to the support frame 430. Therefore, when the slider 432 moves along the guide rail 431 in the Y direction, the support frame 430 and the clamping mechanism 400 mounted on the support frame 430 move together in the Y direction. That is, the moving mechanism 43 moves the slider 432 according to the control command from the control unit 9, thereby moving the clamping mechanism 400 in the Y direction.

[0061] In this embodiment, three sets of clamping mechanisms 400 are arranged along the Y direction and mounted on a support frame 430. They move integrally in the Y direction as the support frame 430 moves. Therefore, each clamping mechanism 400 can move back and forth in the Y direction between the "electroplating position" P1 located above the electroplating tank 41 and the "washing position" P2 located above the tank 44. Figure 2 In the diagram, the chuck mechanism 400 is shown in solid line at the electroplating position P1, and in dashed line at the cleaning position P2. On the other hand, Figure 1 In the image, the chuck mechanism 400 located at the cleaning position P2 is shown in solid line.

[0062] The chuck mechanism 400 holds the substrate S and stably maintains its position within the electroplating tank 41, and makes the built-in cathode electrode electrically contact one of the main surfaces of the substrate S. Furthermore, by applying a DC voltage between the anode and cathode electrodes described below, a coating is formed on this main surface using electrolytic plating. Here, the coating is formed on the upper surface of the substrate S.

[0063] The chuck mechanism 400 holds the substrate S at both ends in the X direction, that is, at both ends in the width direction orthogonal to the transport direction Dt. Furthermore, by providing a plurality of chuck mechanisms 400 along the Y direction, that is, the transport direction Dt of the substrate S, most of the substrate S is held at both ends in the X direction. The chuck mechanism 400 helps to stably maintain the posture of the substrate S by holding it, and in addition, it can hold the cathode electrode 412 (extending along the Y direction) Figure 4B The electroplating apparatus 1 contacts the substrate S and imparts a uniform potential over a large area. Therefore, the electroplating apparatus 1 is able to form an electroplated film with good uniformity on the substrate S.

[0064] Figure 4A and Figure 4B A diagram showing the basic structure of the chuck mechanism. More specifically, Figure 4A A perspective view schematically illustrating the structure of the chuck mechanism 400. Figure 4B The diagram shows the holding state of the chuck mechanism 400 on the substrate S. Furthermore, in the following description of the structure and function of the chuck mechanism 400, the chuck mechanism 400 holding the (-X) side end of the substrate S will be primarily illustrated. However, by considering reversing the same structure around the Z-axis, the structure and operation of the chuck mechanism holding the (+X) side end of the substrate S can be understood. Moreover, to improve the visual clarity of the diagram, Figure 4A A portion of the components of the chuck mechanism 400 is omitted from the illustration.

[0065] The chuck mechanism 400 uses an upper chuck 411 and a lower chuck 421 that can be raised and lowered independently to hold the X-direction end of the substrate S. Specifically, the upper chuck 411 and the lower chuck 421 are both elongated flat plate members extending in the Y-direction. The lower surface 411b of the upper chuck 411 abuts against the (-X) side end of the upper surface Sa of the substrate S, and the upper surface 421a of the lower chuck 421 abuts against the (-X) side end of the lower surface Sb of the substrate S, thereby holding the substrate S. In fact, a cathode electrode 412 is mounted on the lower surface 411b of the upper chuck 411, and the cathode electrode 412 is in contact with the upper surface Sa of the substrate S.

[0066] The cathode electrode 412 is electrically connected to the power supply unit 7. Furthermore, a sealing member 415, formed in an annular shape using an elastic material, is provided around the cathode electrode 412. When the upper clamp 411 is separated from the substrate S, the lower end of the sealing member 415 extends to a position lower than the lower surface of the cathode electrode 412.

[0067] Therefore, as Figure 4BAs shown, when the cathode electrode 412 contacts the upper surface Sa of the substrate S, the sealing member 415 undergoes elastic deformation to surround the cathode electrode 412 in an airtight state. Therefore, when the substrate S is immersed in the electroplating solution, the cathode electrode 412 does not come into contact with the electroplating solution and remains in a dry state. Thus, corrosion or film formation of the cathode electrode 412 caused by contact with the electroplating solution can be prevented.

[0068] like Figure 4B As shown, the lower clamp 421 serves to define the position of the substrate S in the height direction (Z direction) by abutting against the lower surface Sb of the substrate S from below. Furthermore, when the cathode electrode 412 disposed on the upper clamp 411 comes into contact with the substrate S, the lower clamp 421 also functions as a support member. Therefore, it stably maintains the height direction position of the substrate S and also ensures reliable electrical contact between the cathode electrode 412 and the upper surface Sa of the substrate.

[0069] A shaft member 413 extending in the Z direction is mounted on the upper surface 411a of the upper chuck 411. The shaft member 413 is supported by a lifting mechanism 414 in a freely lifting manner. The upper chuck 411 is fixedly connected to the shaft member 413, for example, using screws, and is freely detachable (i.e., replaceable). The lifting mechanism 414 has a suitable linear motion mechanism such as a solenoid, linear motor, or ball screw mechanism to lift the shaft member 413. Therefore, the upper chuck 411 mounted on the lower end of the shaft member 413 is lifted. Here, the unit that includes the upper chuck 411, the shaft member 413, the lifting mechanism 414, etc., and is integrally formed is called the "upper chuck unit 410".

[0070] Similarly, a shaft member 423 extending in the Z direction is mounted on the upper surface 421a of the lower chuck 421, and the shaft member 423 is supported by a lifting mechanism 424 in a freely lifting manner. The lower chuck 421 is fixedly connected to the shaft member 423, for example, using screws, and is freely detachable. The lifting mechanism 424 has a suitable linear motion mechanism, such as a solenoid, linear motor, or ball screw mechanism, to lift the shaft member 423. Therefore, the lower chuck 421 mounted on the lower end of the shaft member 423 is lifted. Here, the unit that includes the lower chuck 421, the shaft member 423, the lifting mechanism 424, etc., and is integrally formed is called the "lower chuck unit 420".

[0071] The upper chuck unit 410 is fixed to the support member 401. Therefore, the upper chuck 411 can only move up and down relative to the support member 401. On the other hand, the lower chuck unit 420 is mounted to the support member 401 via the advance / retract mechanism 402. Specifically, the support member 403 on which the lower chuck unit 420 is mounted is connected to the movable part of the advance / retract mechanism 402, which has the X-direction as its movable direction. The advance / retract mechanism 402 has, for example, a suitable linear motion mechanism such as a solenoid, cylinder, linear motor, or ball screw mechanism, and its main body is fixed to the support member 401.

[0072] Therefore, through the operation of the forward / reverse mechanism 402, the lower chuck unit 420 can move along the X direction within the movable range defined by the stop (not shown). Thus, the lower chuck 421 can move up and down relative to the support member 401 through the operation of the lifting mechanism 424, and can move forward and backward relative to the support member 401 in the X direction by moving the lifting mechanism 424 through the forward / reverse mechanism 402.

[0073] With the lower chuck 421 in its movable range, moved to the position closest to the (+X) side, as follows: Figure 4B As shown by the solid line, the front end of the lower clamp 421 on the (+X) side is located further towards the (+X) side than the end face of the substrate S, and the upper surface 421a of the lower clamp 421 can support the lower surface Sb of the substrate S. On the other hand, as... Figure 4B As shown by the dashed line, when the lower chuck 421 is retracted to its closest (-X) side within its movable range, the front end of the lower chuck 421 on the (+X) side is retracted to a position closer to the (-X) side than the end face of the substrate S. Therefore, it is possible to prevent the lower chuck 421 from contacting the substrate S during lifting and lowering.

[0074] In the chuck mechanism 400, the upper chuck 411 and the lower chuck 421 work together to hold the substrate S within the electroplating tank 41. Specifically, the upper chuck 411 and the lower chuck 421 descend from the chuck mechanism 400, which is positioned at the electroplating location, into the electroplating tank 41, and hold the end of the substrate S at the same height as the substrate S supported by the transfer roller 21. Therefore, within the electroplating tank 41, the substrate S is maintained in a horizontal position with its upper surface flat. Hereinafter, the Z-direction position of the upper chuck 411 and the lower chuck 421 at this time will be referred to as the "lower position".

[0075] like Figure 1 and Figure 3B As shown, an anode electrode unit 45 is disposed above the transport path P within the electroplating tank 41. The anode electrode unit 45 is divided into a plurality of plate-like structures, each having a plurality of anode electrodes 451 that are electrically connected to the power supply unit 7. Furthermore, the anode electrodes 451 are housed in an open, box-shaped isolation tank 450.

[0076] Figure 5 This is a schematic diagram showing the configuration of the main parts of the anode electrode unit. The anode electrode 451 has a plurality of electrode plates arranged in a horizontal direction. Figure 5 In the example shown, nine electrode plates 451a to 451i arranged in a 3×3 matrix constitute the anode electrode 451. The lower surfaces of each electrode plate 451a to 451i facing the substrate S are located in the same horizontal plane.

[0077] The anode electrode 451 is electrically connected to the power supply unit 7 and receives electrical energy. More specifically, the power supply unit 7 has a plurality of output units 71a to 71i, each capable of independently setting its output current. For example, the plurality of electrode plates are electrically connected to the plurality of output units in a one-to-one correspondence, with output unit 71a connected to electrode plate 451a and output unit 71b connected to electrode plate 451b. Each output unit 71a to 71i may be configured, for example, as a DC constant current source or a DC or pulsed current voltage source capable of setting an upper limit for the output current.

[0078] The output current of each output unit 71a to 71i is determined according to the control command from the control unit 9. Specifically, the power supply unit 7 is provided with a setting storage unit 72, which stores information related to the current value that each output unit 71a to 71i should output. Each output unit 71a to 71i outputs a current with a predetermined current value based on the information stored in the setting storage unit 72. The current values ​​of each output unit 71a to 71i stored in the setting storage unit 72 can be changed according to the control command from the control unit 9 and the user's operation input.

[0079] The isolation tank 450 includes a frame 452 that surrounds the anode electrode 451 from the side, and an electrolytic diaphragm 453 that closes the lower part of the frame 452 to form the bottom of the isolation tank 450. The frame 452 is generally rectangular in plan view and extends vertically, and is formed of a material resistant to corrosion by the electroplating solution L, such as a resin material. Furthermore, the electrolytic diaphragm 453 is formed of a material that blocks non-ionized substances while allowing metal ions to pass through, and is in the form of a plate or sheet. For example, the electrolytic diaphragm 453 can be made of porous resin materials, ion exchange resin materials, etc.

[0080] An electrolytic diaphragm 453 is used to enclose the lower part of the frame 452 to form a bottom surface, thus constituting a rectangular box-shaped isolation groove 450 with an open top. The anode electrode 451 is housed within the internal space 454 of this isolation groove 450, as indicated by the single-point chain arrow. Therefore, the frame 452 constituting the isolation groove 450, when viewed from above, has a rectangular shape whose inner wall is slightly larger than the external dimensions of the anode electrode 451. Furthermore, considering the convenience of replacement operations due to the consumption of electrode material, the anode electrode 451 is preferably easily detachable from the isolation groove 450.

[0081] As described below, the isolation tank 450 containing the anode electrode 451 is immersed in the electroplating solution L stored in the electroplating tank 41.

[0082] Figure 6A and Figure 6B A diagram schematically illustrating the state of an isolation tank immersed in an electroplating bath. (Example) Figure 6A As shown, the isolation tank 450 is configured such that at least the lower surface of the electrolytic diaphragm 453 forming its bottom is in contact with the electroplating solution L stored in the electroplating tank 41. Furthermore, a second electroplating solution L2 is injected into the internal space 454 of the isolation tank 450 to the extent that the anode electrode 451 is immersed in the liquid. There is no particular limitation on the composition of the second electroplating solution L2; for example, it can be the same as the first electroplating solution L stored in the electroplating tank 41. Moreover, the term "same composition" here refers to the composition at the point of supply; the composition may change as the process progresses. Furthermore, it may be substantially the same as the first electroplating solution, such as having the same type of main component, but with different concentrations, or with at least one of the following partially different aspects: the presence, type, or content of additives. Furthermore, a liquid with a different composition from the first electroplating solution can also be used as the second electroplating solution, depending on the purpose.

[0083] Therefore, inside the electroplating tank 41, the substrate S supported by the clamping mechanism 400 (upper clamp 411, lower clamp 421) and the anode electrode 451 are arranged opposite each other through the electroplating solution L (+L2) and the electrolytic diaphragm 453.

[0084] A predetermined gap G1 greater than zero is provided between the lower surface of the anode electrode 451 and the upper surface of the electrolytic separator 453. Furthermore, a predetermined gap G2 greater than zero is provided between the lower surface of the electrolytic separator 453 and the upper surface of the substrate S. Therefore, the gap G between the lower surface of the anode electrode 451 and the upper surface of the substrate S is expressed by the following formula, using the thickness t of the electrolytic separator 453: G = G1 + G2 + t.

[0085] like Figure 5 and Figure 6B As shown, each output section 71a-71i has one output terminal independently connected to each electrode plate 451a-451i, while on the other hand, the other output terminal is uniformly connected to the cathode electrode 412. Furthermore, as... Figure 4B As shown, the cathode electrode 412 is disposed at the lower end of the upper clamp 411 and contacts the upper surface of the substrate S.

[0086] Therefore, when a predetermined output current is output from each of the output sections 71a to 71i of the power supply section 7, such as Figure 6BAs indicated by the arrow, a current is generated from the anode electrode 451 flowing towards the upper surface of the substrate S through the electrolytic membrane 453. The electrochemical reaction caused by this current results in an electroplated film being formed on the upper surface of the substrate S.

[0087] In this electrochemical reaction, the non-uniformity of the current density distribution on the upper surface of the substrate S affects the quality of the electroplated film. Ideally, to obtain a film with uniform composition and thickness, a uniform current density distribution should be achieved within the surface of the substrate S. However, the substrate S is an insulator, i.e., a glass product, and its rectangular shape, with the electrical contact with the cathode electrode 412 limited to its periphery, makes it difficult to maintain a uniform current density. In electrolytic plating techniques, as in this embodiment, where the anode electrode faces one main surface of the substrate and the cathode electrode contacts the periphery of the substrate, current concentration tends to occur at the periphery of the substrate. Therefore, there is a tendency for the film thickness at the periphery to be greater than that at the center. In particular, when aiming to shorten the takt time of the electroplating process, it is necessary to increase the current supplied from the power supply unit 7, but this also leads to a larger current deviation.

[0088] As a solution to this problem, one technique aims to mitigate current concentration by covering the periphery of the substrate with a shielding plate. However, for large substrates, such as glass substrates used in display devices, the shielding plate covering the periphery must also be large. Furthermore, the size of the shielding plate must be optimized according to the substrate size, which increases the device cost. Moreover, there is currently insufficient understanding regarding the size and shape of shielding plates that are effective for rectangular substrates.

[0089] In this embodiment, the anode electrode 451 is divided into a plurality of electrode plates 451a to 451i. Furthermore, each electrode plate 451a to 451i is independently connected to an output section 71a to 71i, the output current of which can be independently set. Therefore, by independently adjusting the amount of current supplied to each electrode plate 451a to 451i, the density distribution of the current flowing from the anode electrode 451 toward the substrate S can be varied. Thus, current deviations can be corrected to achieve a nearly uniform current density distribution, thereby improving the uniformity of the electroplated film.

[0090] As described above, current concentration tends to occur at the periphery in rectangular substrates. In view of this, it is expected that among the electrode plates 451a to 451i, the current is less in the electrode plate 451e facing the center of the substrate S, while the current is greater in the other electrode plates arranged to horizontally surround the electrode plate 451e. Therefore, by setting the electrode plate 451e, which is located in the center, to have a greater current than the other electrode plates, it is expected that the current distribution will become more uniform.

[0091] Furthermore, based on the embodiment in which the cathode electrode 412 is in contact with both ends of the substrate S in the X direction, it can be predicted that the end current in the X direction will be larger than the end current in the Y direction. Therefore, it is considered ideal to impart a larger current to the electrode plates 451b and 451h located at both ends in the Y direction in the electrode plate arrangement than to the electrode plates 451d and 451f located at both ends in the X direction.

[0092] Thus, the current input to each electrode plate 451a-451i can be predetermined based on the shape of the substrate S or the electrode arrangement. To achieve more precise uniformity of current density, the current distribution can be measured through preliminary experiments, and the set value of the current supplied to each electrode plate 451a-451i can be determined for each of the output sections 71a-71i. The deviation of the current distribution can then be corrected based on the results.

[0093] For the purpose of uniformizing the current density near the substrate surface, the current setting value can be optimized, for example, in the following manner. Here, the value obtained by dividing the current value applied to each electrode plate by the area of ​​the lower surface of the electrode plate (the surface facing the substrate S) (hereinafter referred to as the "electrode area") is defined as the "electrode current density". Furthermore, considering that the electrode current density represents the current density of the portion of the upper surface Sa of the substrate facing the electrode plate, the output current value for each electrode plate 451a to 451i can be specified in such a way that the electrode current density is an appropriate current density at each position on the substrate S. In this way, the output current value for each electrode plate 451a to 451i can be appropriately set in any case where the electrode areas of each electrode plate 451a to 451i are equal or different.

[0094] For example, in cases where the current density tends to be higher at the periphery and lower at the center of the substrate S, as described above, a uniform current density distribution can be achieved by setting the electrode current density to be higher in the electrode plate 451e located at the center and lower in the other electrode plates located around it. Furthermore, for electrode plates whose lower surface portion, when viewed from above, is located further outward than the substrate S and does not face the substrate S, the area of ​​the portion facing the substrate S can be considered as the effective electrode area. Moreover, unless the periphery of the electrode plate protrudes significantly outward from the substrate S, the current output from the portion located further outward than the substrate S can actually reach the substrate S and contribute to the electroplating reaction. In this case, the entire electrode plate can be considered as an effective electrode and included in the electrode area.

[0095] The specified settings can be stored as default values ​​in the setting storage unit 72 of the power supply unit 7, and the output units 71a to 71i are activated by reading these settings. The user and the control unit 9 can change these settings as needed. Therefore, it is also possible to handle situations where the current distribution must be changed, such as when the size of the substrate S is changed.

[0096] Furthermore, regarding the isolation tank 450, it is also considered that not only the bottom surface but also the sidewalls are made of a material with ion-permeable properties. However, the movement of ions through the sidewalls can cause current to concentrate at the periphery of the substrate, thereby impairing the uniformity of the electroplated film. By allowing ions to move only through the bottom surface of the isolation tank opposite to the upper surface of the substrate S, this current concentration can be prevented.

[0097] For the same reason, if the cathode electrode 412 is positioned directly below the electrolytic membrane 453 at the bottom of the isolation trench 450, a shorter current path will be formed in that area, resulting in current concentration. To avoid this, the cathode electrode 412 is preferably positioned further outward from the area on the upper surface Sa of the substrate opposite the anode electrode 451 when viewed from above, and preferably further outward from the bottom of the isolation trench 450 when contacting the substrate S.

[0098] In this sense, using a non-ion-permeable material to construct the frame 452, or pre-setting the external dimensions of the isolation trench 450 (more precisely, the external dimensions of the electrolytic membrane 453 forming the bottom) to be smaller than the external dimensions of the substrate S, is also effective. In this configuration, ions can be prevented from moving along paths other than the electrolytic membrane 453; therefore, the isolation trench itself can be considered to perform the same function as a shielding plate in the prior art. Figure 6B As shown, in this embodiment, the conditions are met.

[0099] In the electroplating process performed in this manner, a metal soluble in the electrolyte, i.e., the plating solution L, can be used as the anode electrode 451 to form an electroplated film of the metal on the surface of the substrate S. For example, in order to form a copper plating film on the glass substrate, i.e., the substrate S, an aqueous solution of copper sulfate can preferably be used as the plating solution L (L2), and a copper plate can preferably be used as the anode electrode 451.

[0100] By applying a DC voltage between the anode electrode 451 and the cathode electrode 412, a current is supplied to the anode electrode 451, and a metallic material (e.g., copper) is ionized from the anode electrode 451 and dissolved in the electroplating solution L2. The ionized metal adheres to the upper surface of the substrate S via the electrolytic membrane 453 and the electroplating solution L, forming an electroplated film. That is, the anode electrode 451 in this electroplating reaction is a so-called soluble electrode containing the material consumed to form the electroplated film.

[0101] During this process, the anode electrode 451 gradually dissolves in the electroplating solution L (L2). At this time, insoluble impurities contained in the electrode material are released from the anode electrode 451 into the liquid. The insoluble residue generated in the electroplating solution in this way is sometimes referred to as "anode sludge" or "anode mud".

[0102] In this embodiment, the substrate S is supported in a horizontal position with the electroplated surface facing upwards, and an anode electrode 451 is disposed above it. Therefore, anodic sludge containing impurities freed from the anode electrode 451 settles in the electroplating solution towards the substrate S disposed below. If such impurities adhere to the upper surface of the electroplated surface, i.e., the substrate S, it will lead to poor electroplating, thereby reducing the quality of the electroplated film.

[0103] To address this issue, in this embodiment, an isolation layer 450 is used to isolate the anode electrode 451 from the substrate S. Specifically, an electrolytic separator 453 is disposed between the lower surface of the anode electrode 451 and the upper surface of the substrate S, and the sides of the anode electrode 451 are surrounded by a frame 452. Furthermore, the isolation tank 450 is immersed in the electroplating solution L within the electroplating tank 41, and its internal space 454 is filled with an electroplating solution L2 having the same composition as the electroplating solution L.

[0104] Therefore, for the metal ions participating in the electroplating reaction, a path is ensured from the anode electrode 451 through the electroplating solutions L, L2 and the electrolytic membrane 453 toward the substrate S. On the other hand, for the liquid components and insoluble components in the electroplating solution, the anode electrode 451 and the substrate S are isolated from each other by the isolation tank 450. Therefore, the anode sludge formed by the aggregation of insoluble components is blocked by the electrolytic membrane 453 and does not adhere to the substrate S.

[0105] Furthermore, the upper part of the box-shaped isolation tank 450 is open, thus the area above the anode electrode 451 housed in the isolation tank 450 is open. Therefore, the installation / removal of the anode electrode 451 relative to the isolation tank 450 can be easily performed. The anode electrode 451 is gradually consumed as the reaction proceeds, therefore, it must be replaced periodically. The above-described structure also contributes to improving the convenience of this replacement operation.

[0106] Furthermore, the anode electrode 451 is divided into a plurality of electrode plates 451a to 451i. Therefore, replacement operations can be performed on each electrode plate. This improves workability during replacement and allows for the replacement of only the electrode plates in the anode electrode 451 that need to be replaced, thus achieving efficient resource utilization.

[0107] Regarding the spacing between the electrode plates 451a to 451i in the horizontal direction, it is preferably less than, for example, the distance between the lower surface of each electrode plate 451a to 451i and the substrate S, and thus less than half of that distance. If the spacing between the electrode plates becomes larger, there is a risk that insufficient current may be supplied to areas on the upper surface Sa of the substrate that are not aligned with any of the electrode plates, resulting in uneven current density. It is known that the current flowing from the electrode plates diffuses to some extent from the outer edge of the electrode plates in the liquid. According to the inventors of this application, by setting the spacing as described above, this current unevenness can be suppressed.

[0108] Next, the mechanism for supporting the isolation tank 450 in the anode electrode unit 45 will be described. The bottom surface of the isolation tank 450 is positioned opposite the substrate S, and the isolation tank 450 is immersed in the electroplating solution L stored in the electroplating tank 41. Due to the aforementioned structural limitations, the support mechanism for the isolation tank 450 must be positioned above the isolation tank 450. Furthermore, in order to refresh the electroplating solution L2 and suppress the accumulation of anode sludge on the electrolytic membrane 453, it is ideal to periodically replace the electroplating solution L2 stored in the isolation tank 450. The support mechanism described below corresponds to this requirement.

[0109] Figure 7 This is a perspective view of the isolation groove support mechanism in the anode electrode unit. Furthermore, Figure 7 In order to clearly show the structure of the support mechanism, the description of the anode electrode 451 housed in the internal space 454 of the isolation tank 450 is omitted. In the anode electrode unit 45, the isolation tank 450 is mounted on the housing 10 via the support mechanism 460. The support mechanism 460 supports the isolation tank 450 in a manner that allows it to move freely up and down relative to the electroplating tank 41 fixed to the frame 10.

[0110] The support mechanism 460 includes support frames 461, 462, and 463 arranged along the vertical direction (Z direction). The support frames are arranged as follows: the first support frame 461, located at the bottom, supports the isolation groove 450; the second support frame 462, located above it, supports the first support frame 461; and the third support frame 463, located above it, supports the second support frame 462. The third support frame 463 is fixed to the upper frame 11 of the housing 10. Figure 1 , Figure 3A ).

[0111] Each of the support frames 461 to 463 has a generally rectangular shape and forms a frame-like structure that extends vertically through the central part. The uppermost third support frame 463 is equipped with four sets of lifting guide mechanisms 466 that move vertically. Specifically, linear bushings 466a of the lifting guide mechanisms 466 are provided at the four corners of the support frame 463. The linear bushing 466a is a hollow cylindrical member extending vertically, and a movable rod 466b is inserted into this hollow portion. The movable rod 466b extends downward from the linear bushing 466a, and its lower end is connected to the lower second support frame 462.

[0112] If the lifting mechanism 47 operates according to the control command from the control unit 9, the movable rod 466b moves up and down within a predetermined movable range, and thus the second support frame 462 attached to the lower end of the movable rod 466b rises and falls. At this time, the first support frame 461 supported by the second support frame 462, and the isolation groove 450 supported by the first support frame 461, also rise and fall in the same way.

[0113] Similarly, four sets of lifting guide mechanisms 465 with the up-down direction as the direction of movement are installed on the second support frame 462. Specifically, linear bushings 465a of the lifting guide mechanisms 465 are provided at the four corners of the support frame 462, and movable rods 465b are inserted into the hollow parts of the linear bushings 465a. The movable rods 465b extend downward from the linear bushings 465a, and their lower ends are connected to the first support frame 461 located below.

[0114] If the lifting mechanism 47 operates according to the control command from the control unit 9, the movable rod 465b moves up and down within a predetermined movable range, and thus the first support frame 461, which is attached to the lower end of the movable rod 465b, rises and falls. At the same time, the isolation groove 450 supported on the first support frame 461 also rises and falls in the same way.

[0115] Thus, the lifting guide mechanisms 465 and 466 can work in conjunction with the lifting mechanism 47 to move the isolation groove 450 in the vertical direction. As lifting guide mechanisms 465 and 466, in addition to the aforementioned combination of a cylindrical linear bushing and a movable rod, various other mechanisms can be used. For example, mechanisms that restrict the movement of an object in one direction can be used, such as a linear motion guide mechanism combining a guide rail and a slider. Furthermore, lifting guide mechanisms 465 and 466 can also be equipped with a damper function, similar to the lifting guide mechanism 464 described below.

[0116] On the other hand, the first support frame 461 supports the isolation groove 450 in a manner that allows it to move freely up and down and tilt freely about the X-axis. Specifically, four sets of lifting guide mechanisms 464 are installed on the first support frame 461, and movable rods 464b extend downward from the linear bushings 464a of the lifting guide mechanisms 464. As described below, the lifting guide mechanisms 464 have damper mechanisms, thus mitigating the impact transmitted to the isolation groove 450 during its lifting and lowering.

[0117] Furthermore, a frame 455, composed of plates 455a extending in the X direction and plates 455b extending in the Y direction, is installed on the upper part of the frame 452 constituting the isolation groove 450. Hinges 455c are installed at four locations on the upper part of the frame 455. The lower ends of movable rods 464b extending from the four lifting guide mechanisms 464 respectively engage with the hinges 455c located directly below, and are installed to rotate freely about an axis parallel to the X-axis. In this way, the isolation groove 450 is supported on the support frame 461 by the support mechanism 460.

[0118] Furthermore, a roller member 455f is provided between the two hinge members 455c, 455c on the (-Y) side, which are arranged among the four hinge members 455c. This roller member 455f is pivotally supported and can rotate freely by a suitable support member. The roller member 455f is not connected to the drive mechanism and can rotate freely. The function of the roller member 455f will be explained below.

[0119] Furthermore, a device for supplying and discharging electroplating solution L2 to the isolation tank 450 is arranged around the isolation tank 450. That is, a nozzle 491 is provided above the isolation tank 450 for discharging the electroplating solution supplied from the electroplating solution supply and discharge section 49 toward the internal space 454 of the isolation tank 450. The nozzle 491 is mounted on the frame 455 via a suitable fixing member.

[0120] The electroplating solution supply and discharge section 49 and the nozzle 491 are connected by a pipe 492, forming a supply path for the electroplating solution. A flexible joint 493 is provided in this pipe 492 near the isolation tank 450. The flexible joint is a piping component in which at least a portion of the piping is made of a flexible material such as rubber. By inserting the flexible joint into a part of a piping system that is primarily composed of non-flexible pipe materials, the piping is allowed to flex at the insertion point. Flexible joints are widely used, for example, to absorb relative positional shifts or vibrations at the connection points between pipes.

[0121] As described below, in order to efficiently discharge the electroplating solution, the isolation tank 450 is configured to rotate freely about the X-axis. This rotation is allowed by installing the flexible connector 493 into the piping 492, and a supply path for the electroplating solution can be formed between the electroplating solution supply and discharge section 49 and the nozzle 491.

[0122] Furthermore, the isolation tank 450 is also provided with a pipe for discharging the electroplating solution stored in the internal space 454 to the electroplating solution supply and discharge section 49. Specifically, a through hole 452a is provided on the lower part of the side surface on the (+Y) side of the frame 452 constituting the isolation tank 450, and a discharge pipe 494 is connected here. Similar to the electroplating solution supply pipe 492, a flexible connector 495 is also installed and inserted into the discharge pipe 494.

[0123] Furthermore, a lifting mechanism 47, which is fixed to the frame 11 of the housing 10, is provided above the anode electrode unit 45. Here, for the purpose of explaining the principle, the lifting mechanism 47 is provided as a winch mechanism that raises and lowers the object by winding a metal wire. That is, the metal wire 471 hangs down from the lifting mechanism 47, and the metal wire 471 passes through the opening in the center of each support frame 461 to 463 to reach the position directly above the isolation groove 450. The lower end of the metal wire 471 is installed in the locking part 455d provided in the frame 455. The locking part 455d provided in the frame 455 is located closer to the (-Y) side than the middle position of the two hinge members 455c, 455c arranged in the Y direction.

[0124] The lifting mechanism 47 operates according to control commands from the control unit 9, causing the isolation groove 450 and the frame 455, which is locked in place by the metal wire 471, to move together in the vertical direction. Regarding this vertical movement of the isolation groove 450, in addition to the above, various driving mechanisms can be used. For example, known linear motion mechanisms such as ball screw mechanisms, cylinder mechanisms, or linear motor mechanisms can be preferably used, as well as mechanisms commercially available as zip chain actuators (registered trademark).

[0125] Figure 8A and Figure 8B This diagram schematically illustrates the supply of electroplating solution to the isolation tank. Although in Figure 7 Some simplifications have been made, but as Figure 8A As shown, the lifting guide mechanism 464 includes: a linear bushing (also known as a linear motion bearing, linear bearing, etc.) 464a through which a movable rod 464b extending in the vertical direction (Z direction) is inserted; a base member 464c for mounting the linear bushing 464a; a flat bracket 464d mounted on the upper end of the movable rod 464b; and a damper mechanism 464e disposed between the flat bracket 464d and the base member 464c. For example, a known shock absorber can be used as the damper mechanism 464e.

[0126] The movable rod 464b is freely inserted into the linear bushing 464a, moving up and down freely. If the movable rod 464b moves up and down, the bracket 464d also moves up and down accordingly. When the bracket 464d descends, it abuts against the damper mechanism 464e, limiting further downward movement. That is, the damper mechanism 464e functions to allow the movable rod 464b to move up and down, defines its range of motion, and mitigates the impact when the descent stops.

[0127] In the Y direction, two sets of lifting guide mechanisms 464 are provided at different positions. Moreover, the lower end of the movable rod 464b of each lifting guide mechanism 464 engages with the hinge member 455c of the frame 455 mounted on the isolation groove 450. Therefore, in the normal state, the isolation groove 450 is supported in a generally horizontal position.

[0128] With the isolation groove 450 supported in a roughly horizontal position, such as Figure 8A As indicated by the hollow arrow, electroplating solution L2 is supplied from the electroplating solution supply and discharge unit 49 to the isolation tank 450 via pipe 491. Electroplating solution L2 is discharged from the outlet provided on the lower surface of nozzle 491 toward the internal space 454 of the isolation tank 450, thus supplying electroplating solution L2 to the isolation tank 450. Electroplating is performed while the anode electrode 451 is immersed in electroplating solution L2.

[0129] After the electroplating process is completed, the existing electroplating solution is drained and replenished with new electroplating solution, thus updating the electroplating solution L2 within the internal space 454. However, when the electroplating solution L2 is drained from the isolation tank 450, a drain path cannot be provided below the isolation tank 450. This is because a substrate S is positioned directly below the isolation tank 450.

[0130] Furthermore, it is also considered to allow the electroplating solution L2 to flow from the isolation tank 450 to the electroplating tank 41 and then be discharged from the electroplating tank 41. However, in this case, the anodic sludge contained in the electroplating solution L2 would mix into the electroplating tank 41. Therefore, it is preferable to discharge the electroplating solution L2 using a path independent of the path from the electroplating tank 41.

[0131] For the same reason, in supplying the electroplating solution to the isolation tank 450 and in the following process of tilting the isolation tank 450 to promote drainage, it is also necessary to prevent the electroplating solution L2 from overflowing from the isolation tank 450 and flowing into the electroplating tank 41.

[0132] To meet the aforementioned requirements and facilitate drainage, a drain outlet is provided on the side wall of the isolation tank 450 to discharge the electroplating solution to the side. However, compared to providing a drain outlet on the lower surface, the smoothness of drainage is inevitably compromised. Therefore, in this embodiment, a through hole 452a serving as a drain outlet is provided on the (+Y) side of the isolation tank 450 and connected to a drain pipe 494. When discharging the electroplating solution L2, the isolation tank 450 is raised on the side opposite to the drain outlet, i.e., the (-Y) side, causing the bottom surface to tilt. This facilitates the drainage of the electroplating solution L2 from the internal space 454.

[0133] Specifically, the lifting mechanism 47 winds up the metal wire 471, and as... Figure 8B As indicated by the dashed arrow, the (-Y) side end of the isolation groove 450 can be lifted by pulling the frame 455. This causes the isolation groove 450 to be in an inclined position with its bottom surface tilted relative to the horizontal plane. Therefore, as... Figure 8B As indicated by the hollow arrow, the electroplating solution L2 stored in the internal space 454 flows into the through hole 452a, which serves as the discharge outlet. This facilitates the discharge of the electroplating solution L2. Waste liquid flowing into the piping 494 is recovered by the electroplating solution supply and discharge section 49.

[0134] The support embodiment of the isolation groove 450 via the lifting guide mechanism 464 connected by the freely rotating hinge member 455c allows for the tilting of the isolation groove 450. That is, in each of the pair of lifting guide mechanisms 464, 464 arranged at different positions in the Y direction, the movable rod 464b moves up and down independently, thus enabling the isolation groove 450 to be tilted.

[0135] Furthermore, flexible connectors 493 and 495 are respectively installed and inserted into the electroplating solution supply pipe 492 and discharge pipe 494 connected to the isolation tank 450. Therefore, the isolation tank 450 can be tilted while the pipes are connected.

[0136] Figures 9 to 11 This diagram provides a more detailed explanation of the lifting and lowering action of the isolation groove, and more specifically, it illustrates the function of the roller member 455f. Furthermore, in this diagram, for ease of understanding, parts that are not necessary for the explanation are sometimes omitted or the diagram is simplified. Also, to illustrate the function of the roller member 455f, which is obscured by the hinge member 455c, its position is changed to be further towards the (+Y) side than it actually is.

[0137] like Figure 9As shown, a freely rotatable roller member 455f is provided on the upper part of the isolation groove 450. Furthermore, a tapered member 468, whose lower surface is inclined relative to the horizontal plane, is installed on the lower surface of the support frame 461, directly above the roller member 455f. When the lifting mechanism 47 operates and winds up the wire 471 as indicated by the dashed arrow, the isolation groove 450 is pulled upwards while maintaining its inclined posture, and the roller member 455f and the tapered member 468 gradually approach each other.

[0138] like Figure 10 As shown, the roller member 455f abuts against the lower surface, i.e., the inclined surface, of the conical member 468, thus restricting further upward displacement of the roller member 455f. If the isolation groove 450 is pulled further upward in this state, the rise of the (-Y) side end of the isolation groove 450 is restricted by the roller member 455f and the conical member 468, while there is room for further rise at the (+Y) side end of the isolation groove 450.

[0139] Therefore, the (+Y) side end of the isolation groove 450 is further raised, eventually as follows: Figure 11 As shown, the isolation tank 450 is held in a horizontal position. Thus, during the process of lifting the isolation tank 450 from the electroplating tank 41, the isolation tank 450 is temporarily tilted to allow the electroplating solution L2 to be discharged, but eventually the isolation tank 450 returns to a horizontal position.

[0140] When the isolation tank 450 descends from its retracted, upward position, the operation is the reverse of the above. That is, the isolation tank 450 temporarily changes from a horizontal to an inclined position, but returns to a horizontal position when housed in the electroplating tank 41. This allows for the supply of new electroplating solution L2.

[0141] Figure 12 This diagram illustrates the lifting and lowering motion of the entire support mechanism. The operation of the lifting guide mechanism 464, which raises and lowers the isolation groove 450 relative to the support frame 461, was described above. (See diagram below.) Figure 7 As shown, the support mechanism 460 has the following structure: the support frame 461 is supported by the lifting guide mechanism 465 installed on the support frame 462, and the support frame 462 is supported by the lifting guide mechanism 466 installed on the support frame 463.

[0142] The lifting guide mechanisms 465 and 466 are identical in structure and operation to the lifting guide mechanism 464, except that the damper mechanism is omitted. Therefore, the support frame 461 can be raised and lowered relative to the support frame 462, and consequently, the support frame 462 can be raised and lowered relative to the support frame 463. Thus, in the support mechanism 460, it is possible to... Figure 12 As shown in the diagram above, the support frames 461 and 462 are lowered to their lowest positions relative to their respective support bodies, as shown in the diagram. Figure 12As shown in the figure below, the support frames 461 and 462 transition between their highest positions relative to their respective support bodies. The support frame 463 is fixed to the upper frame 11 that constitutes the device housing 10; therefore, this configuration helps to increase the vertical mobility of the isolation groove 450.

[0143] Figure 13 This is a block diagram showing the electrical structure of the electroplating apparatus. In the electroplating apparatus 1 configured as described above, the control unit 9 controls each part of the device to perform a predetermined process. The hardware configuration of the control unit 9 can be, for example, the same as that of a general computer device. That is, the control unit 9 can be equipped with a central processing unit (CPU) 91, memory 92, storage device 93, input unit 94, display unit 95, interface unit 96, etc.

[0144] Memory 92 temporarily stores various data generated during processing. Storage device 93 permanently stores various data and control programs 931. Input unit 94 and display unit 95 are responsible for user interface functions. Interface unit 96 is responsible for communication with external machines, etc.

[0145] The CPU 91 reads and executes the control program 931 pre-stored in the storage device 93, and performs predetermined actions based on this control device, thus realizing the various actions described below. For this purpose, the CPU 91 implements in software functional modules such as a transport control unit 911 that controls the operation of the transport unit 2, a clamp control unit 912 that controls the operation of the clamp head 40, a supply and discharge control unit 913 that controls the supply sources of various fluids and manages their supply and discharge, a flow control unit 914 that controls valves on the piping to adjust the flow rate of the circulating fluid, and a power supply control unit 915 that controls the power supply unit 7 to supply power to the electrodes. At least some of these functional modules may also be configured as dedicated hardware.

[0146] Furthermore, the applicant of this application previously disclosed in Japanese Patent Application Publication No. 2023-180832 an electroplating apparatus with a basic structure similar to the electroplating apparatus 1 of this embodiment, and also described in detail the structure or function of each part of the apparatus, the operation of the apparatus, etc.

[0147] Next, the operation of the electroplating apparatus 1 configured as described above will be explained. The basic operating flow of the electroplating apparatus 1 is roughly as follows: An untreated substrate S is fed into the loading section 3. The substrate S is transported from the loading section 3 to the electroplating processing section 4. The electroplating processing section 4 performs electrolytic electroplating on the substrate S, forming a metal coating on its surface (upper surface Sa). The substrate S, after being electroplated, undergoes rinsing in the rinsing processing section 5 and is finally transported to the unloading section 6.

[0148] Figure 14This is a flowchart illustrating the electroplating process. Furthermore, Figure 15 It is a diagram that schematically represents the actions of each part. More specifically, Figure 15 The diagram shows the actions performed by each part as time T passes, with the time axis viewed from top to bottom. After the unprocessed substrate S is provided to the loading unit 3 at time T0, each part of the device performs the following actions. The initial state of each part is indicated in parentheses in the diagram. Furthermore, Figure 15 In the diagram, the portion of the vertical line of each processing unit represented by a thick solid line indicates that the substrate S exists in that processing unit.

[0149] Each part of the electroplating apparatus 1 is preset to a predetermined initial state. In the initial state, the chuck mechanism 400 is positioned above the electroplating tank 41 at the electroplating position, and the upper chuck 411 and the lower chuck 421 are positioned at an upper position that does not interfere with the electroplating tank 41. Furthermore, as long as it does not obstruct the transport of the substrate S along the transport path P, the upper chuck 411 and the lower chuck 421 can also be positioned further down.

[0150] The substrate S is temporarily held in the loading section 3. In the electroplating processing section 4, the baffles 41a and 41b of the electroplating tank 41 are opened, allowing the substrate S to be transported along the transport path P. At this time, the electroplating solution supplied from the electroplating solution supply section 49 is stored in the electroplating tank 41 to a height where it does not flow out from the opening. Furthermore, for the anode electrode unit 45, the isolation tank 450 is recessed upwards, and no electroplating solution is stored in its internal space 454. In the rinsing processing section 5, the baffles 51a and 51b of the rinsing tank 51 are also opened, allowing the substrate S to be transported along the transport path P. At the unloading section 6, the substrate S is not present at this point in time.

[0151] At time T1, the conveying unit 2 begins to convey the substrate S. The substrate S is conveyed along the conveying path P in the conveying direction Dt (+Y direction) and is finally conveyed to the electroplating tank 41 (step S101). Figure 15 In the diagram, the dashed arrow indicates the transfer of substrate S by the transfer unit 2.

[0152] When the substrate S is moved into the electroplating tank 41, the baffles 41a and 41b are closed. The upper chuck 411 and lower chuck 421 of the chuck mechanism 400 descend toward the substrate S housed in the electroplating tank 41 to hold the substrate S in place (step S102). Furthermore, for the anode electrode unit 45, the isolation tank 450 descends and is positioned opposite the upper surface of the substrate S held in the electroplating tank 41. Alternatively, the substrate S can be moved into the electroplating tank 41 with the isolation tank 450 pre-descended.

[0153] In this state, electroplating solution L is supplied to the electroplating tank 41 from the electroplating solution supply and discharge unit 49 (step S103). Furthermore, in parallel, electroplating solution L2 is supplied to the isolation tank 450 from the electroplating solution supply and discharge unit 49. Therefore, the following is achieved: Figure 6A The state shown is as follows: the substrate S is immersed in the electroplating solution L in the electroplating tank 41, the anode electrode 451 is immersed in the electroplating solution L2 in the isolation tank 450, and the lower surface of the electrolytic diaphragm 453 on the bottom surface of the isolation tank 450 is in contact with the electroplating solution L in the electroplating tank 41.

[0154] Furthermore, the substrate S is electroplated by outputting a predetermined current from each output section 71a of the power supply section 7 (step S104). By contacting the cathode electrode, which extends longer in the Y direction, with the two ends in the X direction of the upper surface Sa of the substrate S, deviations in the current density in the upper surface Sa of the substrate S can be suppressed, thereby forming an electroplated film with good uniformity.

[0155] At this time, the chuck mechanism 400, in conjunction with the conveying roller 21, causes the substrate S to oscillate within the electroplating tank 41 (step S105), thereby further improving the uniformity of the electroplated film. Specifically, through the operation of the moving mechanism 43, the support frame 430 supporting the chuck mechanism 400 alternately and repeatedly moves in the (+Dt) direction and the (-Dt) direction. Therefore, the chuck mechanism 400, mounted on the support frame 430, moves back and forth integrally in the Y direction, and the substrate S held by the chuck mechanism 400 oscillates in the electroplating solution L in the Y direction.

[0156] At this time, the conveying roller 21 is linked with the support frame 430. That is, when the support frame 430 moves in the (+Y) direction and the chuck mechanism 400 moves the substrate S in the (+Y) direction, the conveying roller 21 rotates in the forward direction, that is, it rotates in the direction of conveying the substrate S along the conveying direction Dt. On the other hand, when the support frame 430 moves in the (-Y) direction and the chuck mechanism 400 moves the substrate S in the (-Y) direction, the conveying roller 21 rotates in the reverse direction, that is, it rotates in the direction (-Dt) opposite to the conveying direction Dt, that is, it rotates in the direction of conveying the substrate S along the direction (-Dt).

[0157] By oscillating the substrate S in the electroplating solution L, the solution is agitated to reduce variations in ion concentration, thereby improving the uniformity of the electroplated film. The oscillation of the substrate S within the electroplating tank 41 is achieved through the linkage between a clamping mechanism 400 holding the end of the substrate S and a conveying roller 21 supporting the central portion of the substrate S from the lower surface side. Therefore, localized stress on the substrate S can be prevented, maintaining a horizontal posture and allowing the substrate S to oscillate.

[0158] The substrate S is immersed in the electroplating solution L, and current is supplied between the electrodes, causing the substrate S to oscillate. After this state is maintained for a predetermined time, the current supply is stopped (step S106), thus stopping the electroplating process. Subsequently, the electroplating solution L is discharged from the electroplating tank 41, and the electroplating solution L2 is discharged from the isolation tank 450 (step S107). The discharge from the isolation tank 450 is achieved by the lifting mechanism 47 operating to lift the (-Y) side end of the isolation tank 450 while the isolation tank 450 is retracted to the top by the support mechanism 460.

[0159] Next, the clamping mechanism 400 releases its grip on the substrate S (step S108), and the baffle 41b is opened. At time T2, the conveying unit 2 transfers the substrate S from the electroplating processing unit 4 to the rinsing processing unit 5 (step S109). By releasing the grip on the substrate S after the electroplating solution L is discharged, contact between the cathode electrode 412 and the electroplating solution can be avoided. Furthermore, this restriction does not exist for the anode electrode 451. Therefore, the discharge from the isolation tank 450 can be performed at any time after the current stops. That is, it does not need to be performed simultaneously with the discharge of the electroplating solution L from the electroplating tank 41.

[0160] In the rinsing process unit 5, when the substrate S is housed in the rinsing tank 51, the baffles 51a and 51b are closed. Rinsing liquid is supplied from the rinsing liquid supply and discharge unit 59 to rinse the substrate S (step S110). After the rinsing process has been carried out for a predetermined time, the supply of rinsing liquid is stopped and the baffle 51b is opened. At time T3, the substrate S is transported to the transfer unit 6 (step S111).

[0161] Furthermore, when discharging the electroplating solution from the electroplating tank 41, it is not necessary to completely drain the liquid from the tank. That is, as long as the liquid is drained to the point where the substrate S supported in the tank is exposed and can be moved, it is not a problem for some liquid to remain in the tank. On the contrary, by leaving some liquid, the amount of liquid required to fill the tank when processing the next substrate S can be reduced. This helps to reduce liquid consumption and reduce environmental impact.

[0162] On the other hand, after the substrate S is released from its gripping position, the clamping mechanism 400 undergoes a cleaning process (step S112) to remove the plating solution adhering to the upper clamp 411 and the lower clamp 421. The cleaning process is arbitrary, for example, as described below. That is, the support mechanism 43 moves the support frame 430 in the (-Y) direction, positioning each clamping mechanism 400 in a cleaning position above the cylinder 44. In this state, the cleaning mechanism 48 cleans the clamping mechanisms 400, more specifically the upper clamp 411 and the lower clamp 421, by supplying appropriate cleaning solution or spraying air.

[0163] Regarding the movement of the chuck mechanism 400 between the electroplating position and the cleaning position, such as Figure 2As shown by the dotted lines, the upper chuck 411 and the lower chuck 421 are positioned upwards by the lifting mechanisms 412 and 422. Therefore, contact between the upper chuck 411 and the lower chuck 421 and the wall of the electroplating tank 41 can be prevented beforehand. Hereinafter, the Z-direction position of the upper chuck 411 and the lower chuck 421 at this position will be referred to as the "upper position".

[0164] The cleaned chuck mechanism 400 returns to the electroplating position (step S113). By cleaning the chuck mechanism 400 in this way, residual plating solution can be prevented from adhering to the substrate S when processing the next substrate S. If there is a substrate S that needs further processing, return to step S101 and repeat the above process.

[0165] As described above, in the electroplating apparatus of this embodiment, the substrate S, which is the object to be electroplated, is supported in the electroplating tank 41 in a horizontal position with one of its main surfaces Sa facing upwards, i.e., in an upward-facing state. The cathode electrode 412 is in contact with the periphery of the substrate S, and the anode electrode 451 is arranged facing the upper surface of the substrate S.

[0166] However, the anode electrode 451 is separated from the substrate S by an electrolytic separator 453. Therefore, for metal ions that form the electroplated coating, a pathway is ensured between the anode electrode 451 and the substrate S; on the other hand, for insoluble and liquid components, the anode electrode 451 is isolated from the substrate S. Thus, anodic sludge generated from free matter from the anode electrode 451 adhering to the substrate S and causing a reduction in the quality of the electroplated coating can be avoided.

[0167] Furthermore, the anode electrode 451 is divided into a plurality of electrode plates 451a to 451i, and each electrode plate is independently connected to a constant current source, i.e., an output section 71a to 71i, of the power supply section 7. Moreover, the output current from each output section 71a to 71i can be set independently. Therefore, even when the substrate S is large, deviations in the in-plane current density distribution of the substrate S can be suppressed, thereby achieving uniformity in the thickness of the electroplated film.

[0168] Furthermore, regarding the replacement of the electroplating solution in the isolation tank 450, since the lower surface of the isolation tank 450 is positioned opposite the substrate S, it is difficult to provide a drainage mechanism below the isolation tank 450. Therefore, in this embodiment, a drain outlet is provided on the side wall of the isolation tank 450. Moreover, to efficiently drain the solution, a mechanism is provided on the side opposite to the side wall where the drain outlet is located to lift the end of the isolation tank 450 and tilt its bottom surface. This facilitates the drainage of the electroplating solution.

[0169] That is, the isolation tank 450 of this embodiment can switch between a horizontal position with its bottom surface level and an inclined position with its bottom surface significantly tilted relative to the horizontal plane. In the horizontal position, the anode electrode 451 can be aligned with the substrate S for electroplating. On the other hand, in the inclined position, the electroplating solution remaining in the internal space 454 of the isolation tank 451 can be drained efficiently. Thereafter, new electroplating solution is received, thus maintaining the electroplating solution stored in the internal space 454 in a fresh state.

[0170] <Variation Example>

[0171] Figures 16A to 16C This diagram illustrates a modified example of the anode electrode. In the above embodiment, the anode electrode 451 is obtained by arranging nine electrode plates 451a to 451i, each having approximately the same shape, in a 3×3 matrix. However, the method of dividing the anode electrode into a plurality of parts is not limited to this, and various methods can be considered. For example, in… Figure 16A In the anode electrode 456 shown, electrode plates of approximately the same shape are arranged in a 5×4 matrix. Thus, the number of electrode plates can be arbitrary and is not limited to the above embodiment.

[0172] Moreover, in Figure 16B In the anode electrode 457 shown, a large-area electrode plate is arranged in the central part where a relatively uniform current density is easily obtained. On the other hand, the area of ​​the electrode plate is made smaller in the peripheral and corner parts where current density deviations are prone to occur. Therefore, it is easy to make fine adjustments to the current density distribution. In this way, the shape and size of each electrode plate can be appropriately specified according to the purpose.

[0173] and, Figure 16C The anode electrode 458 shown has a structure in which a rectangular electrode plate disposed in the center is surrounded by multiple rectangular electrode plates with a central opening. This structure allows for the independent setting of current density between the central and peripheral portions of the substrate S.

[0174] Thus, various segmentation patterns for the anode electrode can be considered. When setting the segmentation pattern and distributing the current to each electrode plate, a method can be used, for example, to actually measure the current density distribution through preliminary experiments and determine the pattern based on the results. Specifically, in areas on the substrate surface where the current density variation is small, there is less need to finely segment the opposing electrode plates. Conversely, in areas where the current density variation is large, fine segmentation of the electrode plates allows for easy adjustment of the current density distribution. Furthermore, by making the current setpoint smaller in areas with higher current density, current density homogenization can be achieved.

[0175] In particular, when using clamps to hold two opposing sides of the four sides of a rectangular substrate, since the cathode electrodes are positioned near these two sides, a significant difference in current distribution is predicted between the vicinity of the two unheld sides and the vicinity of the unheld sides. Even in this case, by adjusting the anode electrode segmentation pattern and the supply current value to each electrode plate, deviations in current density distribution can be suppressed, thereby improving the uniformity of the electroplated coating.

[0176] Figure 17A and Figure 17B This is a schematic diagram illustrating a modified example of the support mechanism in the anode electrode unit. Furthermore, here, common or equivalent configurations to those described in the above embodiment are indicated by common symbols and descriptions are omitted. In the above embodiment, the isolation groove 450 is tilted by the lifting mechanism 47 winding up the wire 471, and the wire 471 is installed in the isolation groove 450 at a position offset in the Y direction from the midpoint of the two hinge members 455c arranged along the Y direction. Alternatively, for example, as... Figure 17A As shown, the isolation groove 450 can be supported by two suspension mechanisms 467a and 467b with significantly different spring constants. That is, the isolation groove 450 is supported by the suspension mechanisms 467a and 467b mounted on the support frame 461 and combined with the frame 455 of the isolation groove 450.

[0177] To maintain the isolation groove 450 in a horizontal position, it is preferable to appropriately provide a stop 469 to restrict the downward displacement of the isolation groove 450. Furthermore, the shape or position of the stop is not limited to that shown in the figure, and is arbitrary as long as it can directly or indirectly restrict the downward displacement of the isolation groove 450.

[0178] like Figure 17B As shown by the dashed arrow, when the support mechanism 460 raises the support frame 461, the isolation groove 450 becomes inclined because the spring constants of the two suspension mechanisms 467a and 467b are different. Figure 17B In the example shown, the spring constant of the support mechanism 467a located on the (-Y) side is greater than the spring constant of the suspension mechanism 467b located on the (+Y) side, thus raising the (-Y) side end of the isolation member 450. Therefore, the same effect as in the above embodiment can be obtained. Furthermore, when the support mechanism 460 itself supports the isolation groove 450 via a structure for tilting the isolation groove 450, the lifting mechanism 47 can also use the midpoint of the two hinge members 455c in the Y direction as the point of action to raise and lower the isolation groove 450.

[0179] <Other>

[0180] As explained above, in the above embodiments, the electroplating apparatus 1 corresponds to the "electroplating apparatus" of the present invention, and the electroplating tank 41, the chuck mechanism 400, the cathode electrode 412, and the anode electrode 451 function as the "processing tank," "holding section," "cathode electrode," and "anode electrode" of the present invention, respectively. Furthermore, the electrode plate 451e, located in the central part of each of the electrode plates 451a to 451i, corresponds to the "first electrode" of the present invention, and the other electrode plates correspond to the "second electrode." Moreover, in... Figures 16A-16C In the variant shown, the outermost electrode plate can also be regarded as the "second electrode", and the electrode plate further inside the outermost electrode plate can be regarded as the "first electrode".

[0181] Furthermore, in the above embodiment, the frame 452 of the isolation groove 450 functions as the "shielding frame" of the present invention. Moreover, the power supply unit 7 functions as the "power supply unit" of the present invention, and each of the output units 71a to 71i functions as the "current output unit" of the present invention. Furthermore, the electroplating solution L and electroplating solution L2 correspond to the "electroplating solution" of the present invention.

[0182] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications other than those described can be made without departing from its spirit. For example, in the above-described embodiment, the clamping mechanism 400 is provided on two opposing sides of the rectangular substrate S. However, it is also possible to use the clamping mechanism to hold all or three of the four sides instead.

[0183] Furthermore, for example, the above-described embodiment is configured such that the chuck mechanism 400 holds the substrate S, which is conveyed to the electroplating tank 41 by the conveying roller 21. However, the conveying means is arbitrary and not limited to rollers. On the other hand, an embodiment in which the substrate is conveyed while being held by the chuck mechanism is also considered. In this case, the conveying means are not a necessary configuration, but in order to stably maintain the posture of the large substrate, it is ideal to provide any support unit that supports the central portion of the substrate S from below.

[0184] Furthermore, the substrate to be processed does not necessarily have to be a geometric rectangle in the strict sense. For example, even if there are some irregularities on one side of the substrate, as long as the envelope shape can be regarded as approximately rectangular, it is acceptable.

[0185] Furthermore, for example, the power supply unit 7 in the above embodiment has a constant current output source that corresponds independently to each of the electrode plates constituting the anode electrode 451. Alternatively, the power supply unit can be configured by, for example, a combination of a single voltage source and a plurality of current limiting components provided corresponding to each electrode plate.

[0186] Furthermore, for example, in the power supply unit 7 of the above embodiment, each electrode plate constituting the anode electrode 451 has its own independent output unit. However, several electrode plates can also be connected in parallel to a common output unit. For example, even if it has Figure 16A The anode electrode 456 in the segmented pattern shown can also achieve a substantially similar configuration by connecting several electrode plates in parallel. Figure 16B The anode electrode 457 shown has the same segmentation pattern. Furthermore, the configuration of the connection between the electrode plates and the power supply can be changed as needed.

[0187] Furthermore, for example, in the above embodiment, the anode electrode 451 is divided into a plurality of electrode plates. However, the effect of preventing anode sludge from adhering to the substrate by isolating the anode electrode from the substrate using an isolation tank can also be obtained in an electroplating apparatus where the anode electrode is composed of a single electrode plate.

[0188] Furthermore, in the above embodiment, the liquid stored in the electroplating tank 41 and the liquid stored in the isolation tank 451 are electroplating solutions with the same or substantially the same composition. However, the above configuration is effective even if the compositions of the liquids are different. That is, each liquid can be supplied and discharged independently, and mixing between the two can be avoided.

[0189] Furthermore, the anode electrode 451 in the above embodiment is a soluble electrode containing a metal (e.g., copper) that forms the electroplating film and is consumed during the electroplating process. However, even with an insoluble electrode where the electrode material does not directly contribute to the electroplating reaction, problems of film thickness or film quality inhomogeneity due to deviations in current density distribution still arise. Therefore, in insoluble electrodes, a segmented structure, as described above, allows for independent adjustment of the current, effectively optimizing the current density distribution and achieving uniform film thickness.

[0190] As illustrated in the specific embodiments above, in the electroplating apparatus of the present invention, for example, the second electrode is configured to surround the first electrode in the horizontal direction. With this configuration, the current density can be adjusted independently between the central portion and the peripheral portion of the substrate.

[0191] Furthermore, for example, the lower surfaces of the first electrode and the second electrode can be configured such that they form a plane parallel to a main surface. With this configuration, the correlation between the current output from each electrode and the current flowing to the vicinity of the substrate surface can be improved, thereby enhancing the controllability of the current density.

[0192] Furthermore, for example, the horizontal distance between the first electrode and the second electrode can be less than the vertical distance between the first electrode and a main surface. If the spacing between the electrodes increases, the area in a main surface of the substrate that is not opposite to the electrode becomes larger, and current density is prone to become uneven. By achieving the distance relationship described above, current unevenness can be suppressed by utilizing current diffusion from the electrodes.

[0193] Furthermore, for example, a shielding frame can be provided that surrounds the sides of both the first and second electrodes to block the flow of ions. In this case, the cathode electrode is preferably positioned further outward than the shielding frame and in contact with a main surface when viewed from above. With this configuration, the shortest path of current from the anode electrode to the cathode electrode is shielded by the shielding frame, thus reducing current that is detrimental to the electroplating process. This not only achieves uniformity in the thickness of the electroplated film but also helps to suppress unnecessary energy consumption.

[0194] Furthermore, for example, at least one of the first electrode and the second electrode may be provided in multiples, and in this case, each of the multiple electrodes may be connected to different current output sections. With this configuration, the current density at each position can be adjusted more precisely, and thus, the current density of the entire substrate can be made closer to a uniform state.

[0195] Furthermore, in the electroplating apparatus and method of the present invention, the first electrode and the second electrode may also contain material consumed for forming an electroplated film on a main surface. Such electrodes are so-called soluble electrodes, where the material dissolves and is consumed as the electroplating process proceeds. In this case, there is concern that the current distribution may change as the electrode is consumed. However, in the present invention, an output current is provided, and the electroplating process is performed under conditions that allow for a uniform film thickness; therefore, the deviation in the degree of electrode consumption is small. Thus, fluctuations in current density that occur during the electroplating process can be reduced. Of course, in the case of insoluble electrodes, dividing the electrodes and configuring them with a structure that allows for independent adjustment of the current is also effective in optimizing the current density distribution and achieving uniform film thickness.

[0196] Furthermore, for example, when defining the area of ​​the surface facing a main face as the electrode area for each of the first and second electrodes, and defining the electrode current density as the value obtained by dividing the input current value by the electrode area, it is preferable to set the output current of each current output unit in the power supply section such that the electrode current density in the first electrode is greater than the electrode current density in the second electrode. By introducing the concept of electrode current density in this way, it is possible to adjust the current value by considering not only the current value but also the electrode area. This allows the current value to be set from the perspective of the current density on the substrate. Moreover, by increasing the electrode current density in the first electrode facing the center of the substrate, it is possible to suppress the phenomenon that the film thickness at the periphery is greater than that at the center, thereby achieving uniform film thickness.

[0197] Furthermore, for example, the output current of each current output unit can be changed by the user. Even if the same current density distribution is achieved, the film thickness of the electroplated coating may become uneven depending on the size or shape of the substrate, but automatic control technology for correcting this situation has not yet been established. By allowing for adjustments based on user operation, conditions for achieving uniform film thickness can be achieved even in such cases.

[0198] The present invention has been described above with reference to specific embodiments, but this description is not intended to be interpreted in a limiting sense. As with other embodiments of the invention, various modifications of the disclosed embodiments will be apparent to those skilled in the art. Therefore, the appended claims are to be considered to include such modifications or embodiments without departing from the true scope of the invention.

[0199] Industrial availability

[0200] This invention relates to a technique for forming a coating by electroplating one main surface of a substrate. It is particularly effective when dealing with large rectangular substrates.

[0201] Explanation of reference numerals in the attached figures

[0202] 1: Electroplating equipment

[0203] 2: Transport Department

[0204] 4: Electroplating Department

[0205] 7: Power Supply Section

[0206] 41: Electroplating tank (treatment tank)

[0207] 71a~71i: Output section (current output section)

[0208] 400: Chuck mechanism (holding part)

[0209] 412: Cathode electrode

[0210] 414, 424: Lifting mechanism

[0211] 450: Isolation tank

[0212] 451: Anode electrode (anode electrode section)

[0213] 451a~451d, 451f~451i: Electrode plates (second electrode)

[0214] 451e: Electrode plate (electrode 1)

[0215] 452: Frame (Shielding Frame)

[0216] 453: Electrolytic diaphragm

[0217] L, L2: Electroplating solution

[0218] S: Substrate

[0219] Sa: (the upper surface of substrate S) (a main surface)

Claims

1. An electroplating apparatus for electroplating at least one main surface of a rectangular substrate, wherein, have: Processing tank for storing electroplating solution; The holding section holds the substrate in a horizontal position with one main surface facing upward within the processing tank; The cathode electrode contacts the peripheral portion of one main surface of the substrate held by the holding portion; The anode electrode portion is disposed above the substrate held by the holding portion, and its lower surface is disposed facing the main surface; and A power supply unit is connected to the anode electrode unit and the cathode electrode; The anode electrode portion has: At least one first electrode is opposed to the central portion of the main surface that is more inward than the peripheral portion; and At least one second electrode is opposite to a portion of the main surface that is further outward than the central portion; The power supply unit has a plurality of current output units that can be independently set and changed in terms of output current, and the first electrode and the second electrode are connected to different current output units.

2. The electroplating apparatus as described in claim 1, wherein, The second electrode is configured to surround the first electrode in the horizontal direction.

3. The electroplating apparatus as described in claim 1, wherein, The lower surface of the first electrode and the lower surface of the second electrode form the same plane parallel to the main surface.

4. The electroplating apparatus as described in claim 1, wherein, The horizontal distance between the first electrode and the second electrode is less than the vertical distance between the first electrode and the main surface.

5. The electroplating apparatus as described in claim 1, wherein, It is equipped with a shielding frame that surrounds the sides of both the first electrode and the second electrode to shield the flow of ions. The cathode electrode, viewed from above, is located further outward than the shielding frame and contacts one of the main surfaces.

6. The electroplating apparatus according to any one of claims 1 to 5, wherein, The first electrode and the second electrode contain materials consumed for forming an electroplated coating on the main surface.

7. The electroplating apparatus according to any one of claims 1 to 5, wherein, The first electrode is provided in a plurality of units, each of which is connected to a different current output unit.

8. The electroplating apparatus according to any one of claims 1 to 5, wherein, The second electrode is provided in a plurality of units, each of which is connected to a different current output unit.

9. The electroplating apparatus according to any one of claims 1 to 5, wherein, For both the first electrode and the second electrode, when the area of ​​the surface facing the main face is defined as the electrode area, and the value obtained by dividing the input current value by the electrode area is defined as the electrode current density, In the power supply section, the output current of each of the current output sections is set such that the electrode current density in the first electrode is greater than the electrode current density in the second electrode.

10. The electroplating apparatus according to any one of claims 1 to 5, wherein, The output current of each of the current output units can be changed by the user.

11. An electroplating method for electroplating at least one main surface of a rectangular substrate, wherein, The following steps are required: The step of holding the substrate in a horizontal position with one main surface facing upwards by a holding part in a treatment tank for storing electroplating solution; The steps include: bringing the cathode electrode into contact with a portion of one main surface of the substrate held by the holding portion, and, on the other hand, arranging the anode electrode portion facing the one main surface above the substrate. and The step of outputting current from the power supply unit connected between the anode electrode and the cathode electrode; The anode electrode portion has: at least one first electrode facing the central portion of the main surface that is more inward than the peripheral portion; and at least one second electrode facing the portion of the main surface that is more outward than the central portion. The power supply unit outputs the current to the first electrode and the second electrode from each of the current output units that can independently set and change the output current and are different from each other.

12. The electroplating method as described in claim 11, wherein, The first electrode and the second electrode contain materials consumed for forming an electroplated coating on the main surface.

13. The electroplating method as described in claim 11 or 12, wherein, For both the first electrode and the second electrode, when the area of ​​the surface facing the main face is defined as the electrode area, and the value obtained by dividing the input current value by the electrode area is defined as the electrode current density, Each of the current output sections outputs current in such a way that the electrode current density in the first electrode is greater than the electrode current density in the second electrode.

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