Plating system

Abstract

Provided is a plating system capable of appropriately applying partial plating to a target region. A plating system (10) is provided with: an electrolyte circulation structure (31) having an electrolyte circulation path (310); a target object conveyance structure (32) which is provided with a downward extension part (3211) provided with a plurality of openings (321b), and which conveys a target object (P) along a cylindrical surface in accordance with rotation of the cylindrical surface; and flow rate adjustment parts (20, 33). An electrolyte flowing through the electrolyte circulation path is caused to adhere to the target object via the openings.

Description

Plating system

[0001] The present invention relates to a plating system that applies plating only to necessary portions of an object to be plated.

[0002] Conventionally, in electronic components and the like, plating may be applied only to some necessary portions. For example, in electrode terminal components, by applying partial Au plating only to the portions that become contacts, the amount of Au used for plating can be reduced, contributing to cost reduction.

[0003] Patent Document 1 discloses a plating apparatus that applies plating to the inner surface of an object to be plated by ejecting a plating solution onto the object to be plated from a pair of through-holes provided in a disk rotatably attached to a fixed shaft.

[0004] Patent Document 2 discloses a partial plating apparatus that has a slit-shaped window portion opened to the outside in a part of an electrolytic solution circulation path, and applies partial plating to a plating region on one surface of the object to be plated by transporting the object to be plated along the window portion while opposing the plating region on one surface of the object to be plated to the window portion.

[0005] Chinese Utility Model Publication No. 216192790 Japanese Patent Application Laid-Open No. 2021-165423

[0006] In the ejection-type plating apparatus as disclosed in Patent Document 1, the plating solution is forcefully sprayed onto the object to be plated. Therefore, there is a problem that plating metal (for example, Au) is used excessively because plating is applied to unnecessary portions, increasing the cost.

[0007] In the partial plating apparatus disclosed in Patent Document 2, plating can be applied only to one surface of the object to be plated. However, since the electrolytic solution is brought into contact with one surface of the object to be plated through the slit-shaped window portion, plating is applied to a relatively wide area on one surface of the object to be plated. Therefore, when the area to be plated is narrow, there is a possibility that plating is applied to areas outside the target. That is, there is room for improvement from the viewpoint of reducing the plating metal.

[0008] One aspect of the present invention has been made in view of the above-mentioned problems, and its objective is to provide a plating system that can appropriately perform partial plating on a plated area.

[0009] To solve the above problems, a plating system according to one aspect of the present invention is a plating system for plating a portion of an object to be plated, comprising: an electrolyte circulation unit having an electrolyte circulation path through which an electrolyte flows; an object to be plated transport unit having a cylindrical surface with a plurality of openings, which transports the object to be plated along the cylindrical surface as the cylindrical surface rotates; and a flow rate adjustment unit which adjusts the flow rate of the electrolyte flowing through the electrolyte circulation path, wherein the openings communicate the electrolyte circulation path inside the cylindrical surface with the outside of the cylindrical surface and are provided at positions facing the plated area of ​​the object to be plated that is transported along the cylindrical surface, and the electrolyte flowing through the electrolyte circulation path is deposited on the object to be plated through the openings.

[0010] According to one aspect of the present invention, partial plating can be appropriately applied to the area to be plated.

[0011] This is a front view showing the appearance of the electrolyte supply device and partial plating device, which are the main parts of the plating system according to this embodiment. This is a longitudinal cross-sectional view of the electrolyte supply device. This is a perspective view of the partial plating device. This is a longitudinal cross-sectional view of the partial plating device. This is an enlarged cross-sectional view of the partial plating device showing the position of the object to be plated held by the transport body of the partial plating device. This is an enlarged perspective view of the partial plating device showing the position of the object to be plated held by the transport body of the partial plating device. This is a perspective view showing the transport form of the object to be plated in the partial plating device. This is a diagram showing the relationship between the liquid level of the electrolyte at the opening of the partial plating device and the area to be plated. This is a diagram showing the relationship between the liquid level of the electrolyte at the opening of the partial plating device and the area to be plated. This is a diagram showing the relationship between the liquid level of the electrolyte at the opening of the partial plating device and the area to be plated. This is a diagram showing the relationship between the liquid level of the electrolyte at the opening of the partial plating device and the area to be plated. This is a longitudinal cross-sectional view of an ejector used as an electrolyte suction device. This is a schematic diagram showing an example of a plating system.

[0012] [Embodiment 1] Hereinafter, an embodiment relating to one aspect of the present invention (hereinafter also referred to as "this embodiment") will be described based on the drawings. However, this embodiment described below is merely illustrative in all respects of the present invention. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. In other words, when implementing the present invention, specific configurations according to the embodiment may be appropriately adopted.

[0013] §1 Application Examples First, the configuration of the main parts of the plating system 10 (details will be described later) according to this embodiment will be explained. Figure 1 is a front view showing the external appearance of the electrolyte supply device 20 and the partial plating device 30, which are the main parts of the plating system 10.

[0014] The plating system 10 includes an electrolyte supply device 20 (electrolyte supply unit) and a partial plating apparatus 30. The electrolyte supply device 20 is a device that continuously supplies a fixed amount of electrolyte to the partial plating apparatus 30. Furthermore, as will be described in detail later, as shown in Figure 13, the plating system 10 also includes an electrolyte suction device 33.

[0015] The electrolyte supply device 20 is a flow rate adjustment unit that adjusts the flow rate of the electrolyte flowing through the electrolyte circulation path 310 (see Figure 4) of the partial plating apparatus 30 by supplying the electrolyte at a predetermined supply pressure from the upstream side of the electrolyte circulation path 310. The electrolyte suction device 33 is a flow rate adjustment unit that adjusts the flow rate of the electrolyte flowing through the electrolyte circulation path 310 by suctioning the electrolyte at a predetermined suction pressure from the downstream side of the electrolyte circulation path 310.

[0016] The partial plating apparatus 30 has an electrolyte circulation function and a workpiece transport function. Specifically, the partial plating apparatus 30 circulates the electrolyte supplied from the electrolyte supply device 20 along a predetermined electrolyte circulation path 310. Furthermore, the partial plating apparatus 30 performs partial plating on the workpiece P (see Figures 8 to 11) by transporting it while exposing a portion of it (the plating area) to the electrolyte circulation path 310.

[0017] In particular, in this embodiment, the electrolyte flowing through the electrolyte circulation path 310 is deposited onto the plating target area of ​​the object to be plated P through an opening 321b (see Figure 5) provided in the partial plating apparatus 30. Furthermore, the flow rate of the electrolyte flowing through the electrolyte circulation path 310 is adjusted by the electrolyte supply device 20 to control the liquid surface shape of the electrolyte at the opening 321b (see Figures 8 to 11). More specifically, the amount of electrolyte deposited on the object to be plated P through the opening 321b is adjusted by balancing the electrolyte supply pressure from the electrolyte supply device 20 and the electrolyte suction pressure from the electrolyte suction device 33.

[0018] With this configuration, the partial plating apparatus 30 does not allow the electrolyte to adhere to areas of the object P to be plated other than the plating target area away from the opening 321b. Therefore, the partial plating apparatus 30 can appropriately perform partial plating even on localized plating target areas of the object P to be plated. This leads to a reduction in the amount of plating metal (e.g., Au) used in the object P to be plated, and consequently to cost reduction through partial plating.

[0019] The electrolyte supply device 20 and the partial plating device 30 will be described in detail below.

[0020] §2 Configuration Example [Electrolyte Supply Device 20] Figure 2 is a longitudinal cross-sectional view of the electrolyte supply device 20. The electrolyte supply device 20 has an inlet chamber 21, a supply chamber 22 (first chamber), and a discharge chamber 23 (second chamber), each extending in the vertical direction.

[0021] The inlet chamber 21 has a liquid inlet 211 connected to the pump 50 (see Figure 13). That is, the electrolyte supplied by the pump 50 flows into the inlet chamber 21 through the liquid inlet 211. In Figure 2, the liquid inlet 211 is located on the bottom of the inlet chamber 21, but the liquid inlet 211 may also be located on the side of the inlet chamber 21.

[0022] The supply chamber 22 is positioned adjacent to the inlet chamber 21 and the discharge chamber 23 in a plan view. A first partition wall 24 is provided between the supply chamber 22 and the inlet chamber 21, and a second partition wall 25 (flow rate control partition wall) is provided between the supply chamber 22 and the discharge chamber 23. A liquid supply port 221 (electrolyte supply port) for supplying electrolyte to the partial plating apparatus 30 is provided on the bottom surface of the supply chamber 22. A liquid discharge port 231 (electrolyte discharge port) for discharging excess electrolyte supplied to the electrolyte supply device 20 is provided on the bottom surface of the discharge chamber 23. In addition, a lid 26 is placed over the top surface of the electrolyte supply device 20 to prevent evaporation of the electrolyte.

[0023] In the electrolyte supply device 20, the electrolyte sent to the inflow chamber 21 by the pump 50 flows over the first partition wall 24 into the supply chamber 22. At this time, if the flow rate of the electrolyte sent to the inflow chamber 21 by the pump 50 is equal to or greater than a predetermined flow rate, the liquid level in the supply chamber 22 reaches the height of the second partition wall 25, and the excess electrolyte overflows over the second partition wall 25 to the discharge chamber 23. As long as the liquid level in the supply chamber 22 is maintained at the height of the second partition wall 25, the electrolyte supply device 20 can continuously supply a constant amount of electrolyte from the liquid supply port 221. That is, the liquid level height in the supply chamber 22 is h (m), and the flow path area at the liquid supply port 221 is A (m²). ２ When this is the case, the flow rate Q (m) of the electrolyte supplied from the liquid supply port 221 is ３ The acceleration due to gravity (9.8 m / s) is expressed by the following equation (1). In equation (1), g is the acceleration due to gravity (9.8 m / s²). ２ ) and C is a flow coefficient determined by the density and viscosity of the electrolyte.

[0024] In the electrolyte supply device 20, if the flow rate of electrolyte supplied by the pump 50 is greater than the flow rate Q when the liquid level in the supply chamber 22 is maintained at the height of the second partition wall 25, the flow rate Q can be maintained at a constant amount. At this time, any excess electrolyte supplied by the pump 50 overflows from the supply chamber 22 beyond the second partition wall 25 to the discharge chamber 23, so the liquid level in the supply chamber 22 is maintained at the height of the second partition wall 25. The electrolyte that overflows to the discharge chamber 23 is discharged to the outside of the electrolyte supply device 20 from the liquid discharge port 231. The electrolyte discharged from the liquid discharge port 231 can be sent to, for example, a management tank 52 (see Figure 13), and circulated so that it is sent again to the inlet chamber 21 by the pump 50 from the management tank 52.

[0025] Furthermore, in the electrolyte supply device 20, it is preferable that the bottom position of the inlet chamber 21 is sufficiently higher than the bottom position of the supply chamber 22. This is to reduce the volume of the inlet chamber 21 and prevent excessive accumulation of electrolyte in the electrolyte supply device 20. Also, in Figure 2, the bottom position of the discharge chamber 23 is at the same height as the bottom position of the supply chamber 22, but these do not necessarily have to be at the same height.

[0026] As described above, the electrolyte supply device 20 can control the flow rate Q to a constant level by fixing the liquid level h in the supply chamber 22 and the flow path area A of the liquid supply port 221. It is also possible to adjust the flow rate Q by making the liquid level h or the flow path area A variable. The flow path area A can be easily adjusted, for example, by attaching a flow rate adjustment valve to the liquid supply port 221 and changing the opening degree of the flow rate adjustment valve. The liquid level h can be adjusted by changing the height of the second partition wall 25. The height of the second partition wall 25 can be changed, for example, by constructing the second partition wall 25 by stacking multiple partition plates in the height direction and changing the number of partition plates used. Alternatively, a part of the second partition wall 25 can be made into a movable plate that can slide in the height direction, and the height of the second partition wall 25 can be changed by sliding this movable plate.

[0027] The electrolyte flow rate control by the electrolyte supply device 20 does not require feedback control using flow sensors or the like. Therefore, response delays due to feedback control do not occur, and fluctuations in the flow rate Q can be kept to a minimum. In addition, the electrolyte supplied by the pump 50 flows from the inlet chamber 21 over the first partition wall 24 into the supply chamber 22, and is then supplied from the liquid supply port 221 of the supply chamber 22. Therefore, it is possible to prevent pulsation of the liquid pressure caused by the pump 50 in the electrolyte supplied from the liquid supply port 221.

[0028] [Partial Plating Apparatus 30] Figure 3 is a perspective view of the partial plating apparatus 30. Figure 4 is a longitudinal cross-sectional view of the partial plating apparatus 30.

[0029] The partial plating apparatus 30 is broadly composed of an electrolyte circulation structure (electrolyte circulation section) 31 and a workpiece transport structure (workpiece transport section) 32. In Figure 4, the electrolyte circulation structure 31 is shown with upward-sloping hatching, and the workpiece transport structure 32 is shown with downward-sloping hatching.

[0030] (Regarding the electrolyte circulation structure 31) The electrolyte circulation structure 31 has an electrolyte circulation path 310 through which the electrolyte flows. More specifically, the electrolyte circulation structure 31 has an electrolyte inlet 311 and an electrolyte outlet 312, and has an electrolyte circulation path 310 inside that connects the electrolyte inlet 311 and the electrolyte outlet 312. This electrolyte circulation path 310 is composed of an electrolyte introduction path 313, an electrolyte diffusion path 314, an electrolyte contraction path 315, and an electrolyte discharge path 316.

[0031] The electrolyte inlet 311 is located on the upper surface of the partial plating apparatus 30 and is connected to the electrolyte supply port 221 of the electrolyte supply device 20. This ensures that the partial plating apparatus 30 is continuously supplied with a constant amount of electrolyte from the electrolyte supply device 20. The electrolyte outlet 312 is located at the bottom of the partial plating apparatus 30, and the electrolyte that has circulated through the electrolyte circulation path is discharged to the outside of the partial plating apparatus 30 from the electrolyte outlet 312.

[0032] The electrolyte circulation structure 31 is approximately circular in shape when viewed from above. The electrolyte introduction passage 313 introduces the electrolyte supplied from the electrolyte supply device 20 via the electrolyte inlet 311. The electrolyte introduction passage 313 is located in the center of the electrolyte circulation structure 31 and is positioned vertically. The electrolyte introduction passage 313 is coaxial with the central axis of the downward extension 3211 (see Figure 6) of the workpiece transport structure 32.

[0033] The electrolyte diffusion passage 314 guides the electrolyte from the electrolyte introduction passage 313 so that it spreads in a fan shape toward the downward extension portion 3211 (see Figure 6) of the workpiece transport structure 32. The electrolyte diffusion passage 314 is formed to spread radially along the horizontal direction from the lower end of the electrolyte introduction passage 313. That is, in a plan view, the electrolyte diffusion passage 314 is formed to spread in a fan shape with a central angle of approximately 180 degrees toward the outer edge from the center of the electrolyte circulation structure 31. The above central angle may be changed as appropriate depending on the type of partial plating. The above central angle may be 90 degrees or 120 degrees.

[0034] The electrolyte contraction passage 315 guides the electrolyte from the electrolyte diffusion passage 314 to contract toward the center of the electrolyte circulation structure 31. The electrolyte contraction passage 315 contracts the electrolyte circulation passage, which is radially spread by the electrolyte diffusion passage 314, toward the center from the outer edge of the electrolyte circulation structure 31. That is, in a plan view, the electrolyte contraction passage 315 is formed in a fan shape with a central angle of approximately 180 degrees so as to overlap with the electrolyte diffusion passage 314. The above central angle may be changed as appropriate depending on the type of partial plating. The above central angle may be 90 degrees or 120 degrees.

[0035] In Figure 4, an electrolyte diffusion path 314 and an electrolyte contraction path 315 are provided in the right-hand region of the figure.

[0036] The electrolyte discharge passage 316 guides the electrolyte from the electrolyte contraction passage 315 to be discharged to the outside of the partial plating apparatus 30 via the electrolyte outlet 312. The electrolyte discharge passage 316 is connected to the downstream end of the electrolyte contraction passage 315 (the central end of the electrolyte circulation structure 31), extends vertically, then bends horizontally, and has an electrolyte outlet 312 on the side of the electrolyte circulation structure 31.

[0037] The electrolyte diffusion path 314 and the electrolyte contraction path 315 are connected near the outer edge of the electrolyte circulation structure 31. The parts of the electrolyte diffusion path 314 other than the outer end and the parts of the electrolyte contraction path 315 other than the outer end are separated by an electrolyte partition wall 318, which is part of the electrolyte circulation structure 31.

[0038] Furthermore, the electrolyte circulation path 310 has a portion (hereinafter referred to as the curved portion C) that is convex outward in a cross-section parallel to the central axis of the electrolyte introduction path 313, passing through the central axis. In other words, the electrolyte diffusion path 314 and the electrolyte contraction path 315 are connected near the outer edge of the electrolyte circulation structure 31, in a U-shape when viewed from the horizontal, causing the electrolyte circulation path 310 to be reversed. The curved portion C of the electrolyte circulation path 310 is defined by the outer end of the electrolyte partition wall 318. The outer end of the electrolyte partition wall 318 has a curved shape that is convex outward in a cross-section parallel to the central axis of the electrolyte introduction path 313, passing through the central axis. With this configuration, the electrolyte flowing along the curved electrolyte circulation path can be smoothly guided to the opening. The curved portion C may also be arc-shaped.

[0039] A downward extension 3211 of the object to be plated transport structure 32 is provided at a position opposite the outer end of the electrolyte partition 318. As will be described in detail later, the downward extension 3211 has a plurality of openings 321b for adhering the electrolyte to the object to be plated P.

[0040] The electrolyte circulation structure 31 further includes a cylindrical surface contact portion 319 that abuts against the lower end of the downward extension portion 3211. The cylindrical surface contact portion 319 is located below the electrolyte contraction passage 315 and abuts against the inner surface of the lower end of the downward extension portion 3211 at its outer end.

[0041] (Regarding the plated object transport structure 32 and the plated object P) The plated object transport structure 32 is positioned on top of the electrolyte circulation structure 31 (more specifically, on top of the electrolyte diffusion path 314 and the electrolyte contraction path 315). The plated object transport structure 32 is rotatably mounted relative to the electrolyte circulation structure 31 with the central axis of the electrolyte circulation structure 31 as the axis of rotation.

[0042] The plating object conveying structure 32 includes a conveying main body portion 321 located on the outside. The conveying main body portion 321 holds the plating object P and conveys the plating object P by its rotation.

[0043] The conveying main body portion 321 includes a cylindrical downward extending portion 3211 (cylindrical surface) that extends downward at the outer end portion. The downward extending portion 3211 is coaxial with the central axis of the electrolytic solution introduction path 313. The downward extending portion 3211 is preferably a thin member having a thickness of about 0.5 to 3.0 mm. The downward extending portion 3211 is provided at a position facing the outer end portion of the electrolytic solution partition portion 318 in the electrolytic solution circulation structure 31. That is, the curved portion C of the electrolytic solution circulation path 310 is defined by the outer end portion of the electrolytic solution partition portion 318 and the inner surface of the downward extending portion 3211.

[0044] FIG. 5 is an enlarged cross-sectional view of the partial plating apparatus 30 showing the holding position of the plating object P by the conveying main body portion 321. The reference numeral 1051 in FIG. 5 is a cross-sectional view of the partial plating apparatus 30. The reference numeral 1052 in FIG. 5 is an enlarged cross-sectional view of the region A1 in the reference numeral 1051. The reference numeral 1053 in FIG. 5 is an enlarged cross-sectional view of the region A2 in the reference numeral 1052. FIG. 6 is an enlarged perspective view of the partial plating apparatus 30 showing the holding position of the plating object P by the conveying main body portion 321. Hereinafter, the detailed configuration of the conveying main body portion 321 will be described with reference to FIGS. 5 and 6. In FIG. 6, only two plating objects P are illustrated.

[0045] As shown in the reference numeral 1052 in FIG. 5 and FIG. 6, the conveying main body portion 321 has a plurality of groove portions 321a provided along the circumferential direction near the base end portion of the downward extending portion 3211. The groove portions 321a are grooves extending from the outer surface of the conveying main body portion 321 toward the inside. Pins (not shown) are inserted into the groove portions 321a, and each pin is inserted into a hole provided in the plating object P, whereby the plating object is conveyed. The pin fixing by the pins has a function of positioning the opening 321b of the plating target region in the plating object in addition to the conveyance of the plating object.

[0046] Further, as shown by reference numeral 1052 in FIG. 5 and in FIG. 6, the downward extending portion 3211 is provided with a plurality of openings 321b provided along the circumferential direction at a position corresponding to the curved portion C of the electrolytic solution circulation path 310 in the vertical direction. The openings 321b communicate the electrolytic solution circulation path 310 inside the downward extending portion 3211 with the outside of the downward extending portion 3211. Specifically, the openings 321b are provided at the outermost location of the curved portion C. More specifically, the openings 321b are provided at the terminal end portion (outer end portion) of the electrolytic solution diffusion path 314.

[0047] The work piece P to be plated is held so as to contact the outer surface of the downward extending portion 3211. The work piece P has, for example, as shown in FIG. 6, a first portion p1 having a hole and a second portion p2 including a plating target region. The groove portion 321a is provided at a position facing the hole in the first portion p1. The openings 321b are provided at positions facing the plating target region of the work piece P. In other words, the plating target region of the work piece P with the hole in the first portion p1 aligned with the position of the groove portion 321a is disposed at a position facing the openings 321b.

[0048] The work piece conveyance structure 32 conveys the work piece P along the downward extending portion 3211 as the downward extending portion 3211 rotates. Here, the plating target region of the work piece P conveyed by the work piece conveyance structure 32 always faces the openings 321b. Therefore, the partial plating device 30 can attach the electrolytic solution flowing through the electrolytic solution circulation path 310 to the plating target region in the work piece P through the openings 321b.

[0049] According to the above configuration, the partial plating device 30 does not attach the electrolytic solution to regions other than the plating target region away from the openings 321b in the work piece P. Therefore, the partial plating device 30 can appropriately perform partial plating even on a local plating target region (a region having a size corresponding to the openings 321b) in the work piece P. This leads to a reduction in the amount of plating metal (for example, Au) used in the work piece P, and thus cost reduction due to partial plating.

[0050] As shown by reference numeral 1053 in Figure 5, the electrolyte circulation structure 31 has a chamfered corner 321c on the upstream (upper) edge in the electrolyte flow direction at the opening 321b, on the side (inner) that contacts the electrolyte circulation passage 310. With this configuration, the electrolyte flowing near the opening 321b can be drawn towards the object to be plated P by the Coanda effect (the effect of a viscous fluid jet being attracted to a nearby wall) generated at the corner 321c. In this embodiment, the opening 321b has an outer hole with a substantially constant diameter and an inner hole whose diameter gradually widens inward (i.e., is mortar-shaped). The upper surface of the inner hole functions as the chamfered corner 321c. In this embodiment, the cross-section of the chamfered corner 321c is straight, but it is not limited to this, and the cross-section may be curved.

[0051] Furthermore, the outer surface of the opening 321b is circular. This allows the partial plating apparatus 30 to apply plating to a circular area of ​​the object to be plated P. However, the shape of the outer surface of the opening 321b is not limited to this and can be appropriately changed depending on the area to be plated. The outer surface of the opening 321b may also be elliptical, rectangular, or the like.

[0052] Furthermore, the multiple openings 321b are provided at equal intervals along the circumferential direction in the downward extension portion 3211. This allows simultaneous plating to be applied to each equally spaced plating target area of ​​the workpiece P, which is continuously connected in the circumferential direction. The arrangement of the multiple openings 321b can be appropriately changed depending on the transport method of the workpiece P. The multiple openings 321b may also be provided at non-equal intervals along the circumferential direction in the downward extension portion 3211.

[0053] (Transportation method of the object to be plated P) Figure 7 is a perspective view showing the transport method of the object to be plated P in the partial plating apparatus 30. As shown in Figure 7, in the partial plating apparatus 30, the object to be plated P, which is continuously arranged (each first part p1 is continuously connected in the transport direction), is transported around the opening 321b of the downward extension 3211. The object to be plated transport structure 32 transports the object to be plated P by applying a transport force to the continuously arranged object to be plated P through its rotation. The continuously arranged object to be plated P is separated into individual pieces after plating. The transport force to the continuously arranged object to be plated P may be applied directly to the continuously arranged object to be plated P, or it may be applied to the object to be plated P via a transport belt or the like.

[0054] (Regarding the plating method) Figures 8 to 11 show the relationship between the electrolyte level at the opening 321b and the area to be plated. The plating method for the area to be plated using the partial plating apparatus 30 will be described below with reference to Figures 8 to 11.

[0055] As described above, the electrolyte supply device 20 adjusts the flow rate of the electrolyte through the electrolyte circulation path 310. As an example of adjusting the flow rate of the electrolyte, the electrolyte supply device 20 adjusts the flow rate of the electrolyte so that the electrolyte protrudes outward from the outer surface of the opening 321b due to surface tension. The partial plating device 30 then applies the electrolyte protruding from the opening 321b to the plating target area of ​​the object to be plated P.

[0056] Reference numeral 1081 in Figure 8 indicates the electrolyte level S1 at the opening 321b when the electrolyte supply device 20 has a first flow rate X1. The apex of the liquid level S1 (the outermost point) is located slightly outside the outer surface of the opening 321b. Reference numeral 1082 in Figure 8 indicates the object to be plated P, which has been plated in the plating target area a1 by adhering to the liquid level S1 of the electrolyte. The plating target area a1 is a minute area on the surface of the second part p2.

[0057] Reference numeral 1091 in Figure 9 shows the electrolyte level S2 at the opening 321b when the electrolyte supply device 20 sets the electrolyte flow rate to a second flow rate X2, which is greater than the first flow rate X1. The liquid level S2 is located outside the liquid level S1 and protrudes outward from the opening 321b overall. Reference numeral 1092 in Figure 9 shows the object to be plated P, which has been plated in the plating target area a2 by adhering to the electrolyte level S2. The plating target area a2 is a larger area on the surface of the second portion p2 than the plating target area a1. Note that reference numeral 1091 in Figure 9 is a schematic diagram to clarify the position of the electrolyte level S2, and in reality, the electrolyte level S2 does not overlap with the second portion p2 of the object to be plated P.

[0058] Reference numeral 1101 in Figure 10 shows the electrolyte level S3 at the opening 321b when the electrolyte supply device 20 sets the electrolyte flow rate to a third flow rate X3, which is greater than the second flow rate X2. The liquid level S3 protrudes further outward from the opening 321b than the liquid level S2. Reference numeral 1102 in Figure 10 shows the object to be plated P, which has been plated in the plating target area a3 by adhering to the electrolyte level S3. The plating target area a3 is a larger area than the plating target area a2 and extends across the surface and both sides of the second portion p2. Note that reference numeral 1101 in Figure 10 is a schematic diagram to clearly show the position of the electrolyte level S3, and in reality, the electrolyte level S3 does not overlap with the second portion p2 of the object to be plated P.

[0059] As shown in Figures 8 to 10, the size of the plating area to be partially plated can be changed by adjusting the flow rate of the electrolyte through the electrolyte circulation path 310 using the electrolyte supply device 20 and controlling the amount of electrolyte protruding from the opening 321b. In other words, the partial plating apparatus 30 can perform partial plating on plating areas of various sizes by adjusting the flow rate of the electrolyte according to the size of the area to be plated.

[0060] Figure 11 shows the relationship between the electrolyte level and the plating area when plating an object P' that is different from the object P shown in Figures 8 to 10. The object P' has a convex portion p21 on the surface of the second portion p2, and this convex portion p21 is the plating area.

[0061] In other words, as another example of adjusting the flow rate of the electrolyte, the electrolyte supply device 20 may adjust the flow rate of the electrolyte so that the electrolyte does not protrude outward from the outer surface of the opening due to surface tension. The electrolyte supply device 20 may also adjust the flow rate of the electrolyte so that the electrolyte adheres to the plating target area (convex portion p21) of the object to be plated P' that protrudes from the opening 321b toward the electrolyte circulation path 310 side (inward).

[0062] Reference numeral 1111 in Figure 11 indicates the electrolyte level S4 at the opening 321b when the electrolyte supply device 20 sets the electrolyte flow rate to a fourth flow rate X4, which is less than the first flow rate X1. The liquid level S4 is located along the convex portion p21 and is generally located inward from the outer surface of the opening 321b. Reference numeral 1112 in Figure 11 indicates the plated object P', which has been plated on the convex portion p21 by adhering to the electrolyte level S4.

[0063] As shown in Figure 11, the electrolyte supply device 20 adjusts the flow rate of the electrolyte to form an electrolyte level S4 in the opening 321b that corresponds to the surface of the convex portion p21. This allows the partial plating device 30 to plate only the convex portion p21 of the object to be plated P'. In other words, by adjusting the flow rate of the electrolyte, the partial plating device 30 can perform partial plating even on the protruding areas of the object to be plated P'.

[0064] (Regarding the method for adjusting the flow rate of the electrolyte) A positive potential may be applied to the electrolyte partition wall 318, which may serve as the anode electrode. Alternatively, a negative potential may be applied to the object to be plated P, which may serve as the cathode electrode. This allows the object to be plated P to be plated efficiently in a short time by the electroplating method. Furthermore, the distance between the anode and cathode remains constant while the object to be plated P is being transported, enabling the formation of a plating film with a stable thickness on the object to be plated P.

[0065] Furthermore, to suppress unwanted plating on the object P to be plated, it is effective to generate an attractive force for the electrolyte downstream of the opening 321b (i.e., the electrolyte contraction passage 315). By generating an attractive force for the electrolyte in the electrolyte contraction passage 315, it is possible to more effectively suppress the electrolyte from coming into contact with areas of the object P other than the area to be plated.

[0066] In order to generate an electrolyte suction force in the electrolyte contraction passage 315, one possible configuration is to connect an electrolyte suction device (electrolyte suction unit) 33 to the electrolyte outlet 312 of the electrolyte circulation structure 31. Of course, the electrolyte suction device 33 can also be considered as part of the partial plating apparatus 30.

[0067] As described above, the electrolyte suction device 33 is a flow rate adjustment unit that adjusts the flow rate of the electrolyte flowing through the electrolyte circulation path 310 by suctioning the electrolyte from the downstream side of the electrolyte circulation path 310 at a predetermined suction pressure. For example, a general-purpose ejector, as shown in Figure 12, can be used for the electrolyte suction device 33. When the ejector shown in Figure 12 is used for the electrolyte suction device 33, the ejector's port Po2 is connected to the electrolyte outlet 312, and by flowing the electrolyte from port Po1 to port Po3, a negative pressure is generated at port Po2, which can provide an suction force to the electrolyte contraction path 315 via the electrolyte discharge path 316. This suction force can be adjusted by changing the flow rate of the electrolyte flowing from ports Po1 to Po3 (increasing the A-C flow rate increases the suction force). Furthermore, as shown by reference numeral 1053 in Figure 5, the corners on the downstream (lower) edge of the opening 321b in the direction of electrolyte flow are chamfered on the side (inner) that contacts the electrolyte circulation path 310. This allows for the Coanda effect to be generated in the electrolyte that has passed through the opening 321b, assisting in the suction of the electrolyte in the electrolyte contraction path 315.

[0068] In the partial plating apparatus 30, by appropriately adjusting the flow rate of the supplied electrolyte and the suction force of the electrolyte suction device 33, it is possible to perform good partial plating on the object to be plated P.

[0069] [Plating System 10] Figure 13 is a schematic diagram showing an example of a plating system 10 according to this embodiment. In addition to the electrolyte supply device 20, partial plating device 30, and electrolyte suction device 33 described above, the plating system 10 is equipped with pumps 50, 51 and a management tank 52.

[0070] As shown in Figure 13, the liquid inlet 211 of the electrolyte supply device 20 is connected to the control tank 52 via a pump 50. As a result, the electrolyte is supplied to the liquid inlet 211 from the control tank 52 by the pump 50. The liquid outlet 231 of the electrolyte supply device 20 is connected to the control tank 52, and the electrolyte discharged from the liquid outlet 231 is returned to the control tank 52.

[0071] The electrolyte suction device 33 has port Po2 connected to the electrolyte outlet 312, and ports Po1 and Po3 connected to the control tank 52. The pump 51 is positioned between the control tank 52 and port Po1 (or between the control tank 52 and port Po3) and can circulate the electrolyte from port Po1 to port Po3. In other words, in the electrolyte suction device 33, the electrolyte flowing in from ports Po1 and Po2 both flow out from port Po3 and are returned to the control tank 52.

[0072] (Summary) In order to solve the above problems, the plating system according to embodiment 1 of the present invention is a plating system for plating a portion of an object to be plated, comprising: an electrolyte circulation unit having an electrolyte circulation path through which an electrolyte flows inside; an object to be plated transport unit having a cylindrical surface with a plurality of openings, which transports the object to be plated along the cylindrical surface as the cylindrical surface rotates; and a flow rate adjustment unit which adjusts the flow rate of the electrolyte flowing through the electrolyte circulation path, wherein the openings communicate the electrolyte circulation path inside the cylindrical surface with the outside of the cylindrical surface and are provided at positions facing the plated area of ​​the object to be plated that is transported along the cylindrical surface, and the electrolyte flowing through the electrolyte circulation path is deposited on the object to be plated through the openings.

[0073] With the above configuration, the plating system does not allow the electrolyte to adhere to areas of the object to be plated other than the areas to be plated that are away from the openings. Therefore, the plating system can appropriately perform partial plating even on localized areas of the object to be plated. This leads to a reduction in the amount of plating metal (e.g., Au) used in the object to be plated, and consequently to cost reduction through partial plating.

[0074] In the plating system according to embodiment 2 of the present invention, in embodiment 1, the flow rate adjustment unit comprises an electrolyte supply unit that supplies the electrolyte from the upstream side of the electrolyte circulation path at a predetermined supply pressure, and an electrolyte suction unit that sucks the electrolyte from the downstream side of the electrolyte circulation path at a predetermined suction pressure.

[0075] With the above configuration, the plating system can perform good partial plating on the object to be plated by appropriately adjusting the flow rate of the electrolyte supplied by the electrolyte supply unit and the suction force of the electrolyte suction unit.

[0076] In the plating system according to embodiment 3 of the present invention, in embodiment 1 or 2, the flow rate adjustment unit may adjust the flow rate so that the electrolyte protrudes outward from the outer surface of the opening due to surface tension, and the electrolyte protruding from the opening may be attached to the plating target area of ​​the object to be plated.

[0077] With the above configuration, partial plating can be performed on a flat area of ​​the object to be plated. Furthermore, by adjusting the flow rate of the electrolyte flowing through the electrolyte circulation path using the flow rate adjustment unit and controlling the amount of electrolyte protruding from the opening, the size of the area to be partially plated can be changed. In other words, the plating system can perform partial plating on areas of various sizes by adjusting the flow rate of the electrolyte according to the size of the area to be plated.

[0078] In the plating system according to embodiment 4 of the present invention, in embodiment 1 or 2, the flow rate adjustment unit may adjust the flow rate such that the electrolyte does not protrude outward from the outer surface of the opening due to surface tension, and the electrolyte adheres to the plating target area of ​​the object to be plated that protrudes from the opening toward the electrolyte circulation path.

[0079] According to the above configuration, when the area to be plated on an object to be plated is convex, partial plating can be performed on the area to be plated.

[0080] In the plating system according to embodiment 5 of the present invention, in embodiments 1 to 4 above, the electrolyte circulation path has a portion that is convex outward in a cross section that passes through the central axis of the cylindrical surface and is parallel to the central axis, and the opening may be provided at the outermost part of the curved shape.

[0081] According to the above configuration, the electrolyte flowing along the curved electrolyte circulation path can be smoothly guided to the opening.

[0082] In the plating system according to embodiment 6 of the present invention, in embodiments 1 to 5, the electrolyte circulation section may have a chamfered corner on the surface that is in contact with the electrolyte circulation path at the upstream edge in the flow direction of the electrolyte at the opening.

[0083] With the above configuration, the electrolyte flowing near the opening can be drawn towards the object to be plated by the Coanda effect generated at the corners.

[0084] In the plating system according to embodiment 7 of the present invention, in embodiments 1 to 6 above, the electrolyte circulation path includes an electrolyte introduction path coaxial with the central axis of the cylindrical surface for introducing the electrolyte, and an electrolyte diffusion path that guides the electrolyte from the electrolyte introduction path to spread in a fan shape toward the cylindrical surface, and the opening may be provided at the end of the electrolyte diffusion path.

[0085] According to the above configuration, multiple openings can be provided at the end of the fan-shaped electrolyte diffusion path. Therefore, partial plating can be performed simultaneously on each of the plating target areas of multiple objects to be plated.

[0086] In the plating system according to embodiment 8 of the present invention, in embodiment 2, the electrolyte supply unit has a first chamber into which the electrolyte flowing in from the outside via a liquid inlet flows and which has an electrolyte supply port at the bottom, and a second chamber which is arranged adjacent to the first chamber in a plan view and has an electrolyte discharge port at the bottom, a flow rate control partition wall is provided between the first chamber and the second chamber, and the upper parts of the first chamber and the second chamber may be connected by space.

[0087] With the above configuration, the electrolyte supply unit can control the flow rate supplied from the electrolyte supply unit to the outside by fixing the liquid level in the first chamber and the flow path area of ​​the electrolyte supply unit. It is also possible to adjust the flow rate supplied from the electrolyte supply unit to the outside by making the liquid level or flow path area variable. By adjusting the flow rate supplied from the electrolyte supply unit to the outside, the plating system can perform partial plating on plating target areas of various sizes.

[0088] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0089] 10 Plating system 20 Electrolyte supply device (flow rate adjustment unit, electrolyte supply unit) 21 Inlet chamber 22 Supply chamber (first chamber) 23 Discharge chamber (second chamber) 24 First partition wall 25 Second partition wall (partition wall for flow rate control) 211 Liquid inlet 221 Liquid supply port (electrolyte supply port) 231 Liquid discharge port (electrolyte discharge port) 30 Partial plating device 31 Electrolyte circulation structure 310 Electrolyte circulation path 311 Electrolyte inlet 312 Electrolyte outlet 313 Electrolyte introduction path 314 Electrolyte diffusion path 315 Electrolyte contraction path 316 Electrolyte discharge path 32 Workpiece transport structure (workpiece transport section) 321 Transport body 321b Opening 321c Corner 3211 Downward extension section (cylindrical surface) 33 Electrolyte suction device (flow rate adjustment section, electrolyte suction section)

Claims

1. A plating system for plating a portion of an object to be plated, comprising: an electrolyte circulation unit having an electrolyte circulation path through which an electrolyte flows; an object to be plated transport unit having a cylindrical surface with a plurality of openings, which transports the object to be plated along the cylindrical surface as the cylindrical surface rotates; and a flow rate adjustment unit for adjusting the flow rate of the electrolyte flowing through the electrolyte circulation path, wherein the openings communicate the electrolyte circulation path inside the cylindrical surface with the outside of the cylindrical surface and are located opposite the area to be plated of the object to be transported along the cylindrical surface, and the electrolytic solution flowing through the electrolyte circulation path is deposited on the object to be plated through the openings.

2. The plating system according to claim 1, wherein the flow rate adjustment unit comprises: an electrolyte supply unit that supplies the electrolyte from the upstream side of the electrolyte circulation path at a predetermined supply pressure; and an electrolyte suction unit that suctions the electrolyte from the downstream side of the electrolyte circulation path at a predetermined suction pressure.

3. The plating system according to claim 1, wherein the flow rate adjustment unit adjusts the flow rate so that the electrolyte protrudes outward from the outer surface of the opening due to surface tension, and the electrolyte protruding from the opening is attached to the plating target area of ​​the object to be plated.

4. The plating system according to claim 1, wherein the flow rate adjustment unit adjusts the flow rate such that the electrolyte does not protrude outward from the outer surface of the opening due to surface tension, and the electrolyte adheres to the plating target area of ​​the object to be plated that protrudes from the opening toward the electrolyte circulation path.

5. The plating system according to claim 1, wherein the electrolyte circulation path has a portion that is convex outward in a cross-section parallel to the central axis of the cylindrical surface, and the opening is provided at the outermost part of the curved shape.

6. The plating system according to claim 1, wherein the electrolyte circulation section has a chamfered corner on the surface that contacts the electrolyte circulation path at the upstream edge in the direction of electrolyte flow in the opening.

7. The plating system according to claim 1, wherein the electrolyte circulation path includes an electrolyte introduction path coaxial with the central axis of the cylindrical surface for introducing the electrolyte, and an electrolyte diffusion path for guiding the electrolyte from the electrolyte introduction path to spread in a fan shape toward the cylindrical surface, and the opening is provided at the end of the electrolyte diffusion path.

8. The plating system according to claim 2, wherein the electrolyte supply unit has a first chamber into which the electrolyte flowing in from the outside through a liquid inlet flows and which has an electrolyte supply port at its bottom, and a second chamber arranged adjacent to the first chamber in a plan view and which has an electrolyte discharge port at its bottom, a flow control partition wall is provided between the first chamber and the second chamber, and the upper parts of the first chamber and the second chamber are in communication with each other by space.

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