JP7807063B2 - Plated wire manufacturing method and electroplating apparatus - Google Patents

Description

This specification discloses a method for manufacturing plated wire and an electroplating apparatus used in this manufacturing method.

In electroplating, where a soluble electrode is the anode, this electrode is consumed as the plating progresses. When the electrode is consumed, it is removed from the equipment and a new electrode is installed. This type of electroplating equipment is not suitable for continuous operation.

Electroplating, which uses a non-soluble electrode as the anode, offers excellent continuity. This type of electroplating is suitable for plating metal wire. Pipe-shaped electrodes are particularly suitable for metal wire. An example of a pipe electrode is disclosed in Japanese Patent Application Laid-Open No. 4-94832.

Japanese Unexamined Patent Publication No. 4-94832

In electroplating using pipe electrodes, plating liquid is stored in a tank and the pipe electrode is immersed in this plating liquid. This type of electroplating requires a large amount of plating liquid. In order to form a uniform plating layer, this plating liquid is made to flow. Therefore, a large-scale flow device is required. This type of electroplating is expensive. Moreover, smooth flow is not easy to achieve, so it is difficult to obtain a uniform plating layer.

The applicant's objective is to provide an electroplating apparatus suitable for the low-cost production of plated wire with a uniform plating layer.

The electroplating apparatus disclosed in this specification has a pipe electrode through which a metal wire can travel. The pipe electrode has one or more inlets for allowing plating solution to flow into the pipe electrode and one or more outlets for allowing plating solution to flow out of the pipe electrode. Plated wire can be produced using this electroplating apparatus.

In this electroplating device, the plating liquid flows from the inlet to the outlet. This device makes it easy to form a uniform plating layer on the surface of the metal wire.

FIG. 1 is a schematic cross-sectional view of an electroplating apparatus according to an embodiment, shown together with a metal wire. FIG. 2 is an enlarged cross-sectional view showing the main part of the electroplating apparatus of FIG. 1 together with the metal wire. FIG. 3 is an enlarged cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged cross-sectional view showing the main part of the pipe electrode of FIG. 2 together with the metal wire. FIG. 5 is an enlarged exploded cross-sectional view taken along line VV of FIG. FIG. 6 is an enlarged, partially cutaway view of the first supply of the electroplating apparatus of FIG. FIG. 7 is an enlarged cross-sectional view of the blower of the electroplating apparatus of FIG. 1, shown together with a metal wire. FIG. 8 is an enlarged cross-sectional view showing a plated wire manufactured by the electroplating apparatus of FIG.

A preferred embodiment will be described in detail below, with appropriate reference to the drawings.

The electroplating apparatus 2 shown in Figure 1 has a main section 4, a first power supply 6, a second power supply 8, a blower 10, a tank 12, and a pump 14. Figure 1 also shows a metal wire 16. This metal wire 16 runs in the direction indicated by arrow A1 (from left to right in Figure 1). Examples of materials for the metal wire 16 include carbon steel and alloy steel. A typical alloy steel is stainless steel.

Figures 2 and 3 show the main section 4. This main section 4 includes a tank 18, an outer pipe 20, a pipe electrode 22, two orifices 24, two supply pipes 26, a discharge pipe 28, and two terminals 30. The tank 18 includes a body 32, an inlet gate 34, and an outlet gate 36. The metal wire 16 enters the tank 18 through the inlet gate 34. The metal wire 16 exits the tank 18 through the outlet gate 36.

The tank 18 houses an outer pipe 20. The outer pipe 20 houses a pipe electrode 22. The pipe electrode 22 is therefore housed in the tank 18 via the outer pipe 20. The outer pipe 20 has two inlets 38 and two outlets 40. Each supply pipe 26 is connected to the tank 18. This supply pipe 26 communicates with the inlet 38 of the outer pipe 20. The discharge pipe 28 is also connected to the tank 18.

As shown in Figure 3, a filler 42 is partially filled between the inner surface of the outer pipe 20 and the outer surface of the pipe electrode 22. The filler 42 is made of a synthetic resin composition. Each terminal 30 penetrates the outer pipe 20. The terminals 30 are fixed to the pipe electrode 22. A cable 44 is connected to the terminals 30.

The pipe electrode 22 is shown in Figures 4 and 5. The pipe electrode 22 has a side wall 46, a front opening 48, and a rear opening 50. The pipe electrode 22 has multiple inlets 52. In this embodiment, the pipe electrode 22 has seven inlets 52. Each inlet 52 penetrates the side wall 46. This inlet 52 penetrates the side wall 46 at the lowest position in Figure 4. These inlets 52 are lined up in the axial direction (left-right direction in Figure 4). In other words, each inlet 52 is spaced apart from adjacent inlets 52 in the axial direction. The inner diameter of the inlets 52 is approximately 1.0 mm to 5.0 mm.

This pipe electrode 22 has two lower outlets 54a and two upper outlets 54b. Each lower outlet 54a penetrates the side wall 46. This lower outlet 54a penetrates the side wall 46 at the lowest position in Figure 4. Each upper outlet 54b penetrates the side wall 46. This upper outlet 54b penetrates the side wall 46 at the highest position in Figure 4. In this pipe electrode 22, each inlet 52 is located between two lower outlets 54a in the axial direction.

Figure 4 also shows the metal wire 16. This metal wire 16 runs in the direction indicated by arrow A1 (from left to right in Figure 4). In other words, the metal wire 16 runs inside the pipe electrode 22.

As shown in FIG. 5, the pipe electrode 22 has an upper half 56 and a lower half 58. The cross-sectional shape of the upper half 56 is semicircular. The cross-sectional shape of the lower half 58 is also semicircular. The upper half 56 has an outer layer 60 and an inner layer 62. The lower half 58 also has an outer layer 60 and an inner layer 62.

As shown in Figures 2 and 3, a first space S1 exists inside the pipe electrode 22. A second space S2 exists between the outer peripheral surface of the pipe electrode 22 and the inner peripheral surface of the outer pipe 20. A third space S3 exists between the outer peripheral surface of the outer pipe 20 and the tank 18. The inlet 52 of the pipe electrode 22 connects the first space S1 and the second space S2. Meanwhile, the lower outlet 54a of the pipe electrode 22 is connected to the outlet 40 of the outer pipe 20. The lower outlet 54a and the outlet 40 connect the first space S1 and the third space S3.

Figure 6 is a partially cutaway view showing the first power supply 6. This first power supply 6 has a frame 64, an upper roller 66a (first roller), a lower roller 66b (second roller), an upper bolt 68a, a lower bolt 68b, an upper compression spring 70a, a lower compression spring 70b, an upper bus bar 72a, a lower bus bar 72b, an upper socket 74a, a lower socket 74b, and a tension spring 76. Figure 6 also shows the metal wire 16. This metal wire 16 passes between the upper roller 66a and the lower roller 66b.

The upper roller 66a has a shaft 78a. This shaft 78a attaches the upper roller 66a to the frame 64. The upper roller 66a is rotatable relative to the frame 64. The upper roller 66a can also move up and down relative to the frame 64. The upper bolt 68a passes through the upper compression spring 70a, the upper bus bar 72a, and the upper socket 74a. The upper bolt 68a is fixed to the upper socket 74a, which is fixed to the frame 64. In other words, the upper bolt 68a is fixed to the frame 64 via the upper socket 74a. The upper bolt 68a cannot move relative to the frame 64. The upper bus bar 72a is not fixed to the upper bolt 68a. The upper bus bar 72a can move relative to the upper bolt 68a. The movement direction of the upper bus bar 72a is the up and down direction in Figure 6. The upper bus bar 72a has a terminal 80a. Cable 82a is connected to this terminal 80a.

The upper compression spring 70a pushes the upper bus bar 72a downward. Therefore, the upper bus bar 72a is pressed against the upper roller 66a. In other words, the upper compression spring 70a urges the upper bus bar 72a toward the upper roller 66a.

The lower roller 66b has an axle 78b. The axle 78b attaches the lower roller 66b to the frame 64. The lower roller 66b is rotatable relative to the frame 64. The lower roller 66b may also be movable up and down relative to the frame 64. The lower bolt 68b passes through the lower compression spring 70b, the lower socket 74b, and the lower bus bar 72b. The lower bolt 68b is not fixed to the lower socket 74b. The lower bolt 68b is movable relative to the frame 64. The movement direction of the lower bolt 68b is the up and down direction in FIG. 6. The lower bus bar 72b is fixed to the lower bolt 68b. The lower bus bar 72b moves following the movement of the lower bolt 68b. The movement direction of the lower bus bar 72b is the up and down direction in FIG. 6. The lower bus bar 72b has a terminal 80b. A cable 82b is connected to this terminal 80b.

The lower compression spring 70b pulls the lower bus bar 72b upward via the lower bolt 68b. Therefore, the lower bus bar 72b is pressed against the lower roller 66b. In other words, the lower compression spring 70b urges the lower bus bar 72b toward the lower roller 66b.

The tension spring 76 has a coil 84, an upper hook 86a, and a lower hook 86b. The upper hook 86a is hooked onto the shaft 78a of the upper roller 66a. The lower hook 86b is hooked onto the shaft 78b of the lower roller 66b. The tension spring 76 is suspended between the shafts 78a and 78b. The tension spring 76 urges the upper roller 66a relatively toward the lower roller 66b.

The action of the upper compression spring 70a ensures that the upper bus bar 72a contacts the upper roller 66a. The action of the lower compression spring 70b ensures that the lower bus bar 72b contacts the lower roller 66b. The actions of the upper compression spring 70a, lower compression spring 70b, and tension spring 76 ensure that the metal wire 16 contacts the upper roller 66a and lower roller 66b.

The upper roller 66a and upper bus bar 72a are conductive. Therefore, electricity can flow from the cable 82a to the upper roller 66a. The lower roller 66b and lower bus bar 72b are conductive. Therefore, electricity can flow from the cable 82b to the lower roller 66b.

As is clear from FIG. 1, the first power supply 6 is located on the left side (i.e., upstream side) of the main section 4. As mentioned above, the electroplating apparatus 2 also has a second power supply 8. This second power supply 8 is located on the right side (i.e., downstream side) of the main section 4. Although a detailed description will be omitted, the structure of this second power supply 8 is generally equivalent to the structure of the first power supply 6.

Figure 7 shows the blower 10. The blower 10 includes a block 88 and a tube 90. The block 88 includes a through-hole 92. The through-hole 92 includes gates G1 and G2. A metal wire 16 (or a plated wire, which will be described in detail later) passes through the through-hole 92. The block 88 also includes a first channel 94 and a second channel 96. The first channel 94 includes gates G3 and G4. The first channel 94 intersects with the through-hole 92. The second channel 96 includes gate G5. The second channel 96 extends from gate G5 to the through-hole 92. The tube 90 connects the first channel 94 and the second channel 96. Specifically, the tube 90 connects gate G4 of the first channel 94 to gate G5 of the second channel 96. The tube 90 is also referred to as an intermediate channel.

In this blower 10, a blower (not shown) delivers gas (typically air) from gate G3 into the first channel 94. The air travels in the direction indicated by arrow A2 and collides with the metal wire 16. This air separates the plating liquid (described in detail later) adhering to the metal wire 16 from the metal wire 16. The air exits the first channel 94 through gate G4, as indicated by arrow A3, and flows into the intermediate channel 90. The air travels through the intermediate channel 90, as indicated by arrow A4. The air flows into the second channel 96 through gate G5, as indicated by arrow A5, and also collides with the metal wire 16 in this second channel 96. This air separates the plating liquid (described in detail later) adhering to the metal wire 16 from the metal wire 16. The air travels through the through-hole 92, as indicated by arrow A6. The air passes through gate G1 and then through the exit gate 36 (see Figure 2) of the tank 18, flowing into the interior of the tank 18. As the air flows in, the plating liquid separated from the metal wire 16 is also carried into the interior of the tank 18 and flows into the third space S3. In this electroplating apparatus 2, air collides with the metal wire 16 twice in one blower 10. Multiple collisions promote separation of the metal wire 16 from the plating liquid. This blower 10 is highly efficient. The number of collisions may be three or more.

A plating solution is stored in the tank 12 (see Figure 1). The plating solution contains metal cations. The components of the plating solution are adjusted to obtain the intended material of the plating layer. For example, if the plating layer is made of copper, a preferred plating solution is an aqueous solution of copper pyrophosphate or copper sulfate. If the plating layer is made of zinc, a preferred plating solution is an aqueous solution of zinc sulfate. A pump 14 is connected to the tank 12. This pump 14 can send the plating solution in the tank 12 to the supply pipe 26. The pump 14 circulates the plating solution. The electroplating apparatus 2 may also have circulation means other than the pump 14.

A method for producing plated wire using this electroplating apparatus 2 is described below. In this method, the plating liquid in the tank 12 (see Figure 1) can be sent to the supply pipe 26 by the pump 14. As shown by arrow A7 in Figures 2 and 3, the plating liquid passes through the inlet 38 of the outer pipe 20 and flows into the second space S2. Movement of the plating liquid above the second space S2 is prevented by the filler material 42 (see Figure 3).

When the second space S2 is filled with plating liquid, the plating liquid flows through the inlet 52 of the pipe electrode 22 and into the first space S1, as shown by arrow A8 in Figures 3 and 4. The plating liquid then flows along the axial direction of the pipe electrode 22, as shown by arrow A9 in Figure 4. In other words, the plating liquid flows from the inlet 52 toward the outlet 54. As the plating liquid continues to flow in, the first space S1 is filled with plating liquid.

As the plating liquid continues to flow into the first space S1, excess plating liquid passes through the outlet 54a of the pipe electrode 22 and the outlet 40 of the outer pipe 20, as shown by arrow A10 in Figure 2, and flows out into the third space S3. This plating liquid then flows to the discharge pipe 28, as shown by arrow A11 in Figure 2. After passing through this discharge pipe 28, the plating liquid returns to the tank 12 (see Figure 1).

As mentioned above, plating liquid that has passed through the blower 10 also flows into the third space S3. This plating liquid also flows into the discharge pipe 28, as shown by arrow A11. A portion of the plating liquid in the pipe electrode 22 also flows out of the orifice 24 and into the third space S3. This plating liquid also flows into the discharge pipe 28, as shown by arrow A11. With this electroplating apparatus 2, there is no leakage of plating liquid from the tank 18. Plating using this electroplating apparatus 2 has little adverse impact on the environment.

While the plating solution is circulating, negative power is supplied to the pipe electrode 22 via the cable 44 and terminal 30 shown in FIG. 3. Meanwhile, positive power is supplied to the metal wire 16 via the cable 82, terminal 80, bus bar 72, and roller 66 shown in FIG. 6. The pipe electrode 22 is the anode, and the metal wire 16 is the cathode. Metal ions in the plating solution migrate toward the metal wire 16 and are reduced on its surface. The metal deposited by this reduction adheres to the surface of the metal wire 16. This adhesion continues within the pipe electrode 22. This results in a plated wire with a plating layer. Because the metal wire 16 continuously moves through the pipe electrode 22, plated wire can be produced continuously.

Figure 8 shows a plated wire 98. This plated wire 98 has a metal wire 16 and a plating layer 100. The plating layer 100 is attached to the metal wire 16. The plating layer 100 covers the metal wire 16. In Figure 8, the arrow Dw indicates the wire diameter of the metal wire 16.

As mentioned above, the pipe electrode 22 has an inner layer 62. The material of this inner layer 62 is insoluble in the plating solution. Therefore, even when plated wire 98 is continuously produced, the pipe electrode 22 does not wear out. Examples of materials for the inner layer 62 include iridium oxide, ruthenium oxide, platinum, and platinum-iridium. The inner layer 62 can be formed by coating the outer layer 60 made of a titanium alloy, platinum, or other material. From the standpoints of cost and durability, a pipe electrode 22 in which the outer layer 60 is made of a titanium alloy and the inner layer 62 is made of iridium oxide is preferred. Iridium oxide is particularly suitable for electroplating using zinc sulfate as the plating solution.

The pipe electrode 22, which is insoluble, does not replenish metal ions to the plating solution. In this embodiment, metal ions can be replenished to the plating solution in the tank 12. Plating solution with adjusted composition is continuously supplied to the pipe electrode 22, allowing a uniform plating layer 100 to be formed. The plating solution enters the pipe electrode 22 from the inlet 52 and flows vigorously within the pipe electrode 22. This flow homogenizes the concentration of metal ions in the plating solution near the metal wire 16. This flow can also contribute to the uniformity of the plating layer 100.

The volume of the pipe electrode 22 is small. This electroplating device 2 requires only a small amount of plating liquid to flow. This electroplating device 2 is compact and consumes only a small amount of energy. Furthermore, this electroplating device 2 has excellent current efficiency because the distance between the anode and cathode is short.

As mentioned above, in the first power feeder 6 and the second power feeder 8, springs bias the rollers 66. Therefore, even if the surface of the metal wire 16 is slightly uneven, the rollers 66 reliably contact the metal wire 16. This electroplating device 2 can suppress sparks. Suppressing sparks can contribute to the uniformity of the plating layer 100.

From the viewpoint of a uniform plating layer 100, the number of inlets 52 in the pipe electrode 22 is preferably four or more, and particularly preferably six or more. This number is preferably 20 or less.

As mentioned above, two terminals 30 are fixed to the pipe electrode 22. In an electroplating apparatus 2 in which multiple terminals 30 are fixed to the pipe electrode 22, a uniform plating layer 100 can be formed. The number of terminals 30 may be three or more.

In Figure 4, the arrow Di represents the inner diameter of the pipe electrode 22. The ratio (Di/Dw) of this inner diameter Di to the wire diameter Dw of the metal wire 16 (see Figure 8) is preferably 5 or greater and 15 or less. In an electroplating apparatus 2 with a ratio (Di/Dw) of 5 or greater, sparks caused by contact between the metal wire 16 and the pipe electrode 22 can be suppressed. From this perspective, it is particularly preferable that this ratio (Di/Dw) be 8 or greater. An electroplating apparatus 2 with a ratio (Di/Dw) of 15 or less has excellent current efficiency. From this perspective, it is particularly preferable that this ratio (Di/Dw) be 12 or less.

As shown by arrows A2 and A5 in Figure 7, the air travel direction is inclined relative to the metal wire 16. The air travel direction includes a component in the opposite direction to the travel direction of the metal wire 16. This air thoroughly blows away the plating liquid.

In the embodiment shown in FIG. 1, the blower 10 is located on the right side of the main section 4. In addition to the blower 10, the electroplating apparatus 2 may also have another blower located on the left side of the main section 4. In an electroplating apparatus 2 with two blowers, the metal wire 16 may run from left to right and from right to left.

[Disclosure items]
Each of the following sections discloses a preferred embodiment.

[Item 1]
It has a pipe electrode through which a metal wire can run,
An electroplating apparatus for plating wire, wherein the pipe electrode has one or more inlets for allowing plating solution to flow into the pipe electrode and one or more outlets for allowing the plating solution to flow out of the pipe electrode.

[Item 2]
Item 1. The electroplating apparatus according to item 1, wherein each inlet penetrates a side wall of the pipe electrode.

[Item 3]
3. The electroplating apparatus according to claim 2, having one inlet and another inlet located away from the inlet in the axial direction of the pipe electrode.

[Item 4]
4. The electroplating apparatus according to any one of items 1 to 3, wherein the number of the inlets in the pipe electrode is 4 or more and 20 or less.

[Item 5]
5. The electroplating apparatus according to any one of items 1 to 4, wherein each outlet passes through a side wall of the pipe electrode.

[Item 6]
6. The electroplating apparatus according to any one of items 1 to 5, wherein the pipe electrode has two or more outlets, and each inlet is located between two outlets in the axial direction of the pipe electrode.

[Item 7]
7. The electroplating apparatus according to any one of items 1 to 6, wherein the pipe electrode is insoluble in the plating solution.

[Item 8]
The device further includes an outer pipe that houses the pipe electrode,
8. The electroplating apparatus according to any one of items 1 to 7, wherein the inlet connects a space sandwiched between the outer peripheral surface of the pipe electrode and the inner peripheral surface of the outer pipe to a space inside the pipe electrode.

[Item 9]
The apparatus includes a tank that accommodates the pipe electrode and a blower,
the tank has an exit gate for the metal wire;
9. The electroplating apparatus according to any one of items 1 to 8, wherein the blower blows gas onto the metal wire to send the plating solution adhering to the metal wire into the tank through the exit gate.

[Item 10]
The blower is
a through hole through which the metal wire can pass;
a first channel intersecting the through hole and directing the gas toward the metal wire within the through hole;
a second channel leading to the through hole and directing the gas toward the metal wire within the through hole;
Item 10. The electroplating apparatus according to item 9, further comprising an intermediate channel connecting the downstream of the first channel and the upstream of the second channel.

[Item 11]
It further includes a power supply,
11. The electroplating apparatus according to any one of items 1 to 10, wherein the power supply has a first roller and a second roller for sandwiching the metal wire to make the metal wire a cathode.

[Item 12]
Item 12. The electroplating apparatus according to item 11, wherein the power supply further includes a spring that biases the first roller relatively toward the second roller.

[Item 13]
13. The electroplating apparatus according to any one of items 1 to 12, further comprising a tank capable of storing the plating liquid, and a pump capable of circulating the plating liquid between the tank and the pipe electrode.

[Item 14]
(1) a step of flowing a plating solution through a pipe electrode having an inlet and an outlet from the inlet to the outlet;
and (2) a method for manufacturing a plated wire, the method including the steps of running a metal wire as a cathode inside the pipe electrode, reducing metal ions contained in the plating solution to deposit metal, and attaching the metal to the metal wire.

[Item 15]
Item 15. The manufacturing method according to item 14, wherein in the step (2), the metal wire is made to run having a wire diameter Dw such that the ratio (Di/Dw) of the metal wire to the inner diameter Di of the pipe electrode is 5 or more and 15 or less.

[Item 16]
a through hole through which the metal wire can pass;
a first channel intersecting the through hole and directing the gas toward the metal wire within the through hole;
a second channel leading to the through hole and directing the gas toward the metal wire within the through hole;
and a blower for an electroplating apparatus, comprising an intermediate channel connecting the downstream of the first channel and the upstream of the second channel.

[Item 17]
a first roller and a second roller for sandwiching the metal wire and using the metal wire as a cathode;
and a power supply for an electroplating apparatus, the power supply including a spring for relatively biasing the first roller toward the second roller.

The electroplating apparatus described above is suitable for producing plated wires of various materials. This electroplating apparatus is also suitable for producing plated wires of various sizes.

2: Electroplating apparatus 4: Main part 6: First power supply 8: Second power supply 10: Blow device 12: Tank 14: Pump 16: Metal wire 18: Tank 20: Outer pipe 22: Pipe electrode 26: Supply pipe 28: Discharge pipe 38: Inlet 40: Outlet 46: Side wall 52: Inlet 54a: Lower outlet 54b: Upper outlet 60: Outer layer 62: Inner layer 66: Roller 70: Compression spring 72: Bus bar 76: Tension spring 90: Tube (middle channel)
94: First channel 96: Second channel 98: Plated wire 100: Plated layer S1: First space S2: Second space S3: Third space

Claims (11)

It has a pipe electrode through which a metal wire can run,
the pipe electrode has two or more inlets for allowing the plating solution to flow into the pipe electrode and one or more outlets for allowing the plating solution to flow out of the pipe electrode ;
each inlet penetrates a sidewall of the pipe electrode;
The electroplating apparatus for plated wires , wherein the inlets have one inlet and another inlet located away from the inlet in the axial direction of the pipe electrode . 2. The electroplating apparatus according to claim 1 , wherein the number of the inlets in the pipe electrode is 4 or more and 20 or less. 3. The electroplating apparatus according to claim 1 , wherein the outlet penetrates the side wall of the pipe electrode. 3. The electroplating apparatus according to claim 1 , wherein the pipe electrode has two or more outlets, and each inlet is located between two outlets in the axial direction of the pipe electrode. 3. The electroplating apparatus according to claim 1, wherein said pipe electrode is insoluble in said plating solution. The device further includes an outer pipe that houses the pipe electrode,
3. The electroplating apparatus according to claim 1 , wherein the inlet connects a space sandwiched between the outer peripheral surface of the pipe electrode and the inner peripheral surface of the outer pipe to a space inside the pipe electrode. The apparatus includes a tank that accommodates the pipe electrode and a blower,
the tank has an exit gate for the metal wire;
3. The electroplating apparatus according to claim 1 , wherein the blower blows gas onto the metal wire to send the plating solution adhering to the metal wire into the tank through the exit gate. The blower is
a through hole through which the metal wire can pass;
a first channel intersecting the through hole and directing the gas toward the metal wire within the through hole;
a second channel leading to the through hole and directing the gas toward the metal wire within the through hole;
8. The electroplating apparatus according to claim 7 , further comprising an intermediate channel connecting the downstream of the first channel and the upstream of the second channel. It further includes a power supply,
3. The electroplating apparatus according to claim 1 , wherein the power supply has a first roller and a second roller for sandwiching the metal wire to make the metal wire a cathode. 10. The electroplating apparatus of claim 9 , wherein the power supply further comprises a spring for biasing the first roller relatively toward the second roller. 3. The electroplating apparatus according to claim 1 , further comprising a tank capable of storing said plating liquid, and a pump capable of circulating said plating liquid between said tank and said pipe electrode.