JP2012102352A - Method for producing plated wire rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a plating layer on the surface of a wire rod without coating it with a flux.SOLUTION: The method for producing the plated wire rod 10 comprises softening a wire rod 11 by passing it through an annealing furnace 23 and subsequently forming a plating layer on its surface so as to coat its surface by immersing it in a molten metal M. The method further comprises removing an oxide film from the surface of the wire rod 11 by feeding a reducing gas into the annealing furnace 23 to reduce the surface of the wire rod 11.

Description

  The present invention relates to a plated wire, a manufacturing method thereof, and a manufacturing apparatus.

  In order to facilitate electrical connection, a plated wire provided with a solder plating layer so as to cover the wire is used as a lead wire used in the wiring of an electric / electronic device or the like.

  As a method for producing such a plated wire, Patent Literature 1 discloses a method in which an electrolytic acid is degreased on a wire, an organic acid flux is applied to remove an oxide film, and the resultant is immersed in a molten metal.

  In Patent Document 2, the wire is passed through the flux tank and the flux is attached to the surface thereof to remove the oxide film. Then, the wire is passed through a pretreatment device to remove excess flux attached to the surface, and the wire is further removed. A method for immersing the material in molten metal is disclosed.

  In addition, as a flux-free plating method, Patent Document 3 describes that a wire material that has been subjected to hot-dip plating is immersed in a molten metal that is at least 100 ° C. higher than the melting point without application of flux, A method is disclosed in which a wire is raised vertically without passing through a non-oxidizing atmosphere without using a jig for squeezing molten metal.

JP-A-5-59512 JP 2008-24971 A JP-A-2-129354

  By the way, when plating a wire that has been annealed and extremely softened, when the flux for removing the oxide film is attached to the extremely softened wire, the wire is introduced into the flux and then the turn provided in the liquid. It is wound around a roll and pulled up, and therefore undergoes bending deformation. However, since the extremely softened wire is cured when subjected to bending deformation, it is preferable that the bending history in the manufacturing process is small. In particular, in the case of a flat wire, the demand is strong.

  The subject of this invention is forming a plating layer in the surface, without apply | coating a flux to a wire.

  In the method for producing a plated wire according to the present invention, the wire is softened by passing through an annealing furnace. Then, when the plating layer is formed so as to cover the surface by immersing in the molten metal, By introducing a reducing gas, the surface of the wire is reduced to remove the oxide film.

  The plated wire of the present invention includes a flat wire and a plating layer provided so as to cover the surface of the wire, and does not contain a flux component.

  An apparatus for producing a plated wire rod according to the present invention includes an annealing furnace through which a wire passes, and a plating tank for storing a molten metal into which the wire that has passed through the annealing furnace is immersed. It is comprised so that an exit can be located in the molten metal stored by the said plating tank.

  According to the present invention, when softening the wire through the annealing furnace, the oxide film is removed by reducing the surface of the wire with the reducing gas introduced into the annealing furnace. The surface of the wire can be plated by passing through the molten metal.

(A)-(c) is a perspective view of the plated wire which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the plating wire manufacturing apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the plating wire manufacturing apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the structure of the modification of the plating wire manufacturing apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the structure of another modification of the plating wire manufacturing apparatus which concerns on Embodiment 2. FIG.

  Hereinafter, embodiments will be described in detail based on the drawings.

(Embodiment 1)
1A to 1C show a plated wire 10 according to the first embodiment. The plated wire rod 10 according to the first embodiment is used as an interconnector that subdivides and connects cells in a solar battery, for example.

  The plated wire 10 according to the first embodiment is composed of a flat wire provided with a flat metal wire 11 and a solder plating layer 12 provided so as to cover the surface thereof. And the plating wire 10 which concerns on Embodiment 1 does not contain a flux component. Here, the rectangular wire constituting the plated wire rod 10 is shown in FIG. 1B, which is formed by compressing a round wire from four sides in addition to a rectangular cross section having a corner as shown in FIG. In such a cross section as shown in FIG. 1 (c) formed by compressing the round line from above and below, the upper and lower sides are straight and both sides are arcuate. A track-shaped track with a flat and substantially rectangular cross section is also included. The flat wire 10 is, for example, 1 to 2 mm in width and 0.1 to 0.2 mm in thickness. In addition, the plated wire 10 may be a round wire or a square wire in addition to a flat wire.

  Examples of the metal constituting the wire 11 include oxygen-free copper and tough pitch copper. The wire 11 can be obtained by a known processing method in which wire drawing or a combination of wire drawing and rolling is performed.

  The solder composition for forming the solder plating layer 12 is Sn—Pb alloy having a melting point of about 130 to 300 ° C., Sn— (0.5 to 5 mass%) Ag alloy, Sn— (0.5 to 5 mass%). Ag- (0.3-1.0 mass%) Cu alloy, Sn- (0.3-1.0 mass%) Cu alloy, Sn- (1.0-5.0 mass%) Ag- (5- 8 mass%) In alloy, Sn- (1.0-5.0 mass%) Ag- (40-50 mass%) Bi alloy, Sn- (40-50 mass%) Bi alloy, Sn- (1.0 -5.0 mass%) Ag- (40-50 mass%) Bi- (5-8 mass%) In alloy etc. are mentioned. Since Pb is harmful to the human body and may contaminate the natural environment, Pb-free Sn—Ag alloy, Sn—Ag—Cu alloy, Sn—Cu alloy, Sn—Ag—In alloy are used from the viewpoint of pollution prevention. A solder material such as a Sn-Ag-Bi alloy is preferable, and specifically, a Sn-3.0 mass% Ag-0.5 mass% Cu alloy is preferable. The thickness of the solder plating layer 12 is preferably 5 to 80 μm, and more preferably 10 to 50 μm.

  The plated wire 10 according to the first embodiment is preferably subjected to an ultrasoftening treatment (annealing treatment), so that the 0.2% proof stress is preferably 60 MPa or less, and more preferably 50 MPa or less.

  Examples of the flux component not contained in the plated wire 10 include rosin component materials such as abietic acid, amines and salts thereof, an organic acid having an aliphatic skeleton such as sebacic acid, azelaic acid, and corkic acid. Etc.

  Next, the manufacturing method of the plated wire 10 which concerns on Embodiment 1 is demonstrated.

  FIG. 2 shows a plated wire manufacturing apparatus 20 used in the manufacturing method of the plated wire 10 according to the first embodiment.

  The plated wire manufacturing apparatus 20 according to the first embodiment includes a wire supply part 21, a cleaning tank 22, an annealing furnace 23, a plating tank 24, and a wire recovery part 25.

  The wire supply unit 21 is configured such that a bobbin B around which a round wire 11 is wound is attached, and includes a rolling mill (not shown). In this wire supply part 21, the round wire 11 is drawn from the bobbin B, cold-rolled in the vertical direction by a rolling mill, and sent to the washing tank 22 as a flat wire 11.

  The cleaning tank 22 is formed in a long shape, and cleaning liquid is stored in the tank. In the cleaning tank 22, the wire 11 from the wire supply unit 21 is immersed in the cleaning liquid, passes through the cleaning material, and is cleaned and removed, and then is pulled up and sent to the annealing furnace 23. The immersion length of the wire 11 in the cleaning liquid is, for example, 0.5 to 5 m.

  The annealing furnace 23 has a configuration in which a wire rod insertion tube 23b is inserted in a longitudinal direction through a long box-shaped furnace body 23a and is provided in a penetrating state. The heater is provided inside the furnace body 23a. The annealing furnace 23 is configured to be tiltable between a horizontal position during standby and an inclined position during processing. When the annealing furnace 23 is positioned at the inclined position, the tip of the wire rod insertion tube 23b protruding downstream from the furnace body 23a. The portion is immersed in the molten solder M (molten metal) in the plating tank 24 described later, so that the wire rod outlet at the downstream end of the annealing furnace 23 is positioned in the molten solder M (molten metal) in the plating tank 24. It is configured. In addition, a reducing gas supply pipe 26 is connected to the wire rod insertion pipe 23b protruding to the downstream side of the furnace body 23a so that the reducing gas flows in the annealing path 23 from the downstream side to the upstream side. In this annealing furnace 23, the wire 11 from the cleaning tank 22 is introduced into a high-temperature reducing gas atmosphere, is annealed through it, the surface is reduced by the reducing gas, and the oxide film is removed. It is sent out from the wire rod outlet into the molten solder M in the plating tank 24. The reducing gas supply pipe 26 may be connected to a portion other than the wire rod insertion pipe 23b protruding downstream from the furnace body 23a. However, from the viewpoint of efficiently removing the oxide film with the reducing gas, Thus, it is preferable that the reducing gas supply pipe 26 is connected to the wire rod insertion pipe 23 protruding to the downstream side of the furnace body 23a, and the reducing gas flows from the downstream side to the upstream side. The heating length of the wire 11 in the annealing furnace 23 is, for example, 0.5 to 5 m. The inner diameter of the wire rod insertion tube 23b is, for example, 5 to 30 mm.

  The plating tank 24 stores molten solder M in the tank. In this plating tank 24, the wire 11 from the annealing furnace 23 is immersed in the melted solder M, wound around a turn roll 27 provided in the solder, and then comes out of the melted solder M to reach the plating tank 24. The air-cooling is performed until the wire is wound around a pulling roll 28 provided above, and thereby, the plated wire rod 10 on which the solder plating layer 12 is formed so as to cover the surface is manufactured. A cooler that cools the wire 11 pulled up from the plating tank 24 may be provided above the plating tank 24. Further, a die for adjusting the thickness of the solder plating layer 12 formed on the wire 11 pulled up from the plating tank 24 may be provided. However, since it is difficult to adjust the thickness of the thin solder plating layer 12 such as 20 to 40 μm by the die, the solder attached to the wire 11 falls downward by its own weight, and the thickness of the solder plating layer 12 can be adjusted. Thus, the structure provided with the raising roll 28 so that the wire 11 pulled up from the plating tank 24 may be extended vertically upwards may be sufficient.

  The wire rod recovery unit 25 has a bobbin B attached thereto and is configured to rotate the attached bobbin B. In this wire rod recovery unit 25, the plated wire rod 10 extending from the plating tank 24 via the pulling roll 28 is wound around the bobbin B and collected.

  In the plated wire manufacturing apparatus 20 according to the first embodiment, a guide roll R is provided between the respective parts, and thereby, the wire 11 or the plated wire 10 is guided. In addition, the plated wire manufacturing apparatus 20 according to the first embodiment may be configured to manufacture only a single plated wire 10 at a time, but from the viewpoint of obtaining high productivity, a plurality of plated wires 10 are simultaneously formed. It is preferably configured to manufacture.

  In the manufacturing method of the plated wire rod 10 according to the first embodiment, the above-described plated wire rod manufacturing apparatus 20 according to the first embodiment is used. Rolled and sent out as a rectangular wire 11 and recovered as a plated wire 10 of a product in the wire recovery unit 25. The feed speed of the wire 11 is, for example, 2 to 50 m / min.

  And in the washing tank 22, the oil etc. of the surface of the wire 11 are washed and removed with a washing liquid. Examples of the cleaning liquid include water (warm water), an organic solvent, and the like. When the cleaning liquid is water, the water temperature is, for example, 10 to 60 ° C. The cleaning liquid may contain a detergent.

  In the annealing furnace 23, the wire 11 is annealed in a high-temperature reducing gas atmosphere, and the oxide film is removed by reducing the surface with a reducing gas. At this time, the reducing gas flows in the annealing furnace 23 from the downstream side to the upstream side, whereby the oxide film on the surface of the wire 11 can be effectively removed. The temperature in the furnace is preferably 300 to 900 ° C., more preferably 500 to 800 ° C. from the viewpoint of effectively softening the wire 11. Examples of the reducing gas include hydrogen gas and carbon monoxide gas. Among these, hydrogen gas is preferable from the viewpoint of working environment. Moreover, it is preferable to introduce into the annealing furnace 23 a reducing gas diluted with an inert gas. Examples of the inert gas include nitrogen gas and argon gas. Among these, nitrogen gas is preferable from the viewpoint of versatility. The concentration of the reducing gas contained in the gas introduced into the annealing furnace 23 is preferably 10 to 80% by volume, and more preferably 20 to 50% by volume from an economic viewpoint. The flow rate of the gas supplied into the annealing furnace 23 is, for example, 2 to 3 L / min.

  In the plating tank 24, the molten solder M is attached to the surface of the wire 11, pulled up and air-cooled, and the solder plating layer 12 is formed so as to cover the surface of the wire 11. The temperature of the molten solder M is, for example, 230 to 300 ° C. The temperature of the wire 11 when entering the solder M in the plating tank 24 is preferably 100 to 500 ° C., and preferably 150 to 450 ° C. from the viewpoint of suppressing the thickness of the solder plating layer 12.

  In the wire rod collection unit 25, the plated wire rod 10 is wound around the bobbin B and collected.

  As described above, according to the method of manufacturing the plated wire 10 according to the first embodiment, when the flat wire 11 is softened in the annealing furnace 23, the surface of the wire 11 is reduced by the reducing gas introduced into the annealing furnace 23. Since the oxide film is removed, the wire 11 from which the oxide film has been removed is immersed in the melted solder M following the annealing furnace 23 without being applied with the flux, and is exposed to the surface of the wire 11. The solder plating layer 12 can be formed. Therefore, since no flux is used, it is possible to prevent the plated wire 10 after plating from being deteriorated due to corrosion or the like. Moreover, there is no contamination of the equipment by the flux, and the equipment cost can be kept low.

(Embodiment 2)
FIG. 3 shows an annealing furnace 23 and a plating tank 24 in the plated wire manufacturing apparatus 20 according to the second embodiment. In addition, the part of the same name as Embodiment 1 is shown with the same code | symbol.

  In the plated wire manufacturing apparatus 20 according to the second embodiment, the annealing furnace 23 has an outlet member 23c connected to the downstream end of the wire insertion tube 23b that protrudes downstream of the furnace body 23a. The outlet member 23c is configured by a pipe having an inner diameter larger than that of the wire rod insertion tube 23b, and is provided coaxially after the wire rod insertion tube 23b. Thus, the space through which the wire 11 passes is configured to discontinuously expand from the wire insertion tube 23b to the outlet member 23c. The downstream end of the outlet member 23c is configured as a wire outlet positioned in the solder M. The inner diameter of the outlet member 23c is, for example, 20 to 50 mm.

  From the viewpoint of heating efficiency in the furnace main body 23a, the inner diameter of the wire insertion tube 23b is preferably small. On the other hand, when the downstream end of the wire insertion tube 23b having a small inner diameter is configured as a wire outlet and positioned in the solder M, The wire 11 before and after introduction into the solder M comes into contact with the inner wall of the wire insertion tube 23b due to wire blurring, and the surface of the wire 11 is scratched, or the surface of the plated plating wire 10 is scratched or plated. May peel off. However, since the outlet member 23c having an inner diameter larger than that of the wire insertion tube 23b as described above is connected to the downstream end of the wire insertion tube 23b, the wire 11 before and after introduction into the solder M is wired. Contact with the inner wall of the pipe due to blurring is avoided, and as a result, generation of scratches on the surface of the wire 11 or the plated wire 10 can be suppressed.

(Other embodiments)
In the first and second embodiments, the round wire 11 is immersed in the melted solder M with the flat wire 11 formed by cold rolling using a rolling mill (not shown). Instead of this, a bobbin B around which the wire 11 formed into a rectangular shape by cold rolling in advance in a separate process is attached to the apparatus, and the wire 11 may be plated. The method for forming the round wire 11 into a flat rectangular shape may be any known method such as wire drawing in addition to rolling, and is not particularly limited.

  Moreover, in the said Embodiment 1 and 2, the wire rod exit of the downstream end of the annealing furnace 23 is located in the melt | dissolved solder M in the plating tank 24, and the wire 11 which passed the annealing furnace 23 fuse | melted without touching air | atmosphere. Although it was set as the structure immersed in the solder M, it is not limited to this in particular.

  In the first and second embodiments, the wire 11 is dipped in the molten solder M to form the solder plating layer 12, but the present invention is not limited to this, and the dipped in other molten metal is plated. A layer may be formed.

  In the second embodiment, the outlet member 23c is configured by a pipe having an inner diameter larger than that of the wire rod insertion pipe 23b. However, the present invention is not particularly limited thereto. For example, as illustrated in FIG. It may be configured by a cone-shaped member, and a structure in which the space through which the wire 11 passes continuously expands and changes from the wire insertion tube 23b to the outlet member 23c, and the outlet member 23c faces downward as shown in FIG. You may comprise by the box-shaped cover member opened in.

  A plated wire was manufactured using a plated wire manufacturing apparatus having the same configuration as that of the first embodiment.

(Manufacture of plated wire)
<Production Example 1>
An oxygen-free copper having a width of 2.0 mm and a thickness of 0.2 mm as a wire, water having a water temperature of 40 ° C. as a cleaning liquid, and Sn-3.0% Ag-0.5% Cu as a molten solder Those at 290 ° C. were used. Then, the wire feed rate is set to 10 m / min, 100% by volume of hydrogen gas is supplied from the reducing gas supply pipe at a flow rate of 2 L / min, and the furnace temperature in the annealing furnace is set to 400 ° C. Manufactured.

<Production Example 2>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 50% by volume of hydrogen gas and 50% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature in the annealing furnace was 400 ° C. .

<Production Example 3>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature of the annealing furnace was 400 ° C. .

<Production Example 4>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 5% by volume of hydrogen gas and 95% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature in the annealing furnace was 400 ° C. .

<Production Example 5>
A plated wire was produced under the same conditions as in Production Example 1 except that a mixed gas of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature of the annealing furnace was set to 200 ° C. .

<Production Example 6>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature in the annealing furnace was set to 300 ° C. .

<Production Example 7>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature of the annealing furnace was set to 500 ° C. .

<Production Example 8>
A plated wire was produced under the same conditions as in Production Example 1 except that a mixed gas of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature in the annealing furnace was set to 600 ° C. .

<Production Example 9>
A plated wire was produced under the same conditions as in Production Example 1 except that a gas mixture of 20% by volume of hydrogen gas and 80% by volume of nitrogen gas was supplied from a reducing gas supply pipe and the furnace temperature of the annealing furnace was set to 800 ° C. .

(Evaluation methods)
<Reduction treatment>
The degree of adhesion of the solder plating layer of the plated wire obtained in Production Examples 1 to 9 above is visually confirmed, “◎” indicates that there is no unplated portion, “○” indicates that there is a fine unplated portion, And what was not plated at all was evaluated as "x".

<Extreme softening treatment>
The 0.2% proof stress of the plated wires obtained in the above Production Examples 1 to 9 was measured, and those of 50 MPa or less were “◎”, those of 50 MPa or less and 60 MPa or less were “◯”, and were greater than 60 MPa. Things were rated as “x”.

(Evaluation results)
Table 1 shows the evaluation results.

  Regarding the reduction treatment, Production Example 1 is A, Production Example 2 is A, Production Example 3 is A, Production Example 4 is X, Production Example 5 is X, Production Example 6 is B, Production Example 7 is A, Production Example 8 Was ◎ and Production Example 9 was ◎. From this result, it can be seen that for the reduction treatment, the ratio of the reducing gas is preferably 20% by volume or more, and the in-furnace temperature of the annealing furnace is preferably 300 ° C. or more.

  For the ultra-softening treatment, Production Example 1 is x, Production Example 2 is x, Production Example 3 is x, Production Example 4 is x, Production Example 5 is x, Production Example 6 is x, Production Example 7 is ○, Production Example 8 was ◎, and Production Example 9 was ◎. From this result, it is understood that the furnace temperature of the annealing furnace is preferably 500 ° C. or higher for the extreme softening treatment.

  The present invention is useful for a plated wire, a manufacturing method and a manufacturing apparatus thereof.

DESCRIPTION OF SYMBOLS 10 Plated wire 11 Wire 12 Solder plating layer 20 Plating wire manufacturing apparatus 21 Wire supply part 22 Cleaning tank 23 Annealing furnace 23a Furnace main body 23b Wire material insertion pipe 23c Outlet member 24 Plating tank 25 Wire material collection part 26 Reducing gas supply pipe 27 Turn roll 28 Lifting roll B Bobbin R Guide roll

The present invention relates to method and apparatus for manufacturing a plated wire.

In the method for producing a plated wire according to the present invention, the wire is softened by passing through an annealing furnace. Then, when the plating layer is formed so as to cover the surface by immersing in the molten metal, By introducing the reducing gas so that the reducing gas flows from the downstream side to the upstream side, the surface of the wire is reduced to remove the oxide film, and the wire outlet of the annealing furnace is positioned in the molten metal,
The annealing furnace
A furnace body with a heater inside;
A wire rod insertion tube provided in the furnace body and projecting downstream thereof,
An outlet member connected to the downstream end of the wire rod insertion tube and having an inner diameter larger than the wire rod insertion tube and constituting a wire rod outlet positioned in the molten metal;
To have a.

The plated wire manufacturing apparatus of the present invention is a plated wire manufacturing apparatus comprising an annealing furnace through which a wire passes, and a plating tank storing molten metal into which the wire that has passed through the annealing furnace is immersed,
The wire outlet of the annealing furnace is configured to be positioned in the molten metal stored in the plating tank ,
The annealing furnace
A furnace body with a heater inside;
A wire rod insertion tube provided in the furnace body and projecting downstream thereof,
An outlet member connected to the downstream end of the wire rod insertion tube and having an inner diameter larger than the wire rod insertion tube and constituting a wire rod outlet positioned in the molten metal;
Have
A reducing gas supply pipe is connected to the wire insertion pipe of the annealing furnace so that the reducing gas flows from the downstream side to the upstream side .

The present invention is useful for a method and an apparatus for manufacturing a plated wire.

The present invention relates to the manufacture how plating wire.

The method of manufacturing a plated wire according to the present invention includes a solar cell interconnector in which a copper wire is softened by passing through an annealing furnace, and then a plated layer is formed so as to cover the surface by dipping in a molten metal. A method of manufacturing a plated wire used in
By introducing a mixed gas containing 20 to 80% by volume of hydrogen gas into the annealing furnace so that the mixed gas flows from the downstream side to the upstream side, the surface of the wire is reduced to remove the oxide film. Position the wire exit of the annealing furnace in the molten metal,
The annealing furnace
A furnace body with a heater provided therein and the furnace temperature set to 600 ° C. or higher ;
A wire rod insertion tube provided in the furnace body and projecting downstream thereof,
An outlet member connected to the downstream end of the wire rod insertion tube and having an inner diameter larger than the wire rod insertion tube and constituting a wire rod outlet positioned in the molten metal;
It is a manufacturing method of the plating wire which has 0.2% proof stress which is 50 MPa or less.

The present invention is useful with the production how plating wire.

Claims (8)

A method for producing a plated wire, wherein the wire is softened by passing through an annealing furnace, followed by forming a plating layer so as to cover the surface by immersing in molten metal,
A method for producing a plated wire material, wherein the surface of the wire material is reduced by introducing a reducing gas into the annealing furnace to remove the oxide film. In the manufacturing method of the plated wire according to claim 1,
The manufacturing method of the plating wire which positions the wire exit of the said annealing furnace in molten metal. In the manufacturing method of the plated wire according to claim 2,
The annealing furnace
A furnace body with a heater inside;
A wire rod insertion tube provided in the furnace body and projecting downstream thereof,
An outlet member connected to the downstream end of the wire rod insertion tube and having an inner diameter larger than the wire rod insertion tube and constituting a wire rod outlet positioned in the molten metal;
The manufacturing method of the plated wire which has this. In the manufacturing method of the plated wire according to any one of claims 1 to 3,
A method for producing a plated wire, wherein the reducing gas is introduced into the annealing furnace so that the reducing gas flows from the downstream side to the upstream side.   A plating wire comprising a flat wire and a plating layer provided so as to cover the surface of the wire, and containing no flux component. In the plated wire according to claim 5,
A plated wire used for an interconnector of a solar cell having a 0.2% proof stress of 60 MPa or less. An annealing furnace through which the wire passes, and a plating tank for storing a molten metal in which the wire that has passed through the annealing furnace is immersed,
The plating wire manufacturing apparatus comprised so that the wire exit of the said annealing furnace can be positioned in the molten metal stored by the said plating tank. In the plated wire manufacturing apparatus according to claim 7,
The annealing furnace
A furnace body with a heater inside;
A wire rod insertion tube provided in the furnace body and projecting downstream thereof,
An outlet member connected to the downstream end of the wire rod insertion tube and having an inner diameter larger than the wire rod insertion tube and constituting a wire rod outlet positioned in the molten metal;
An apparatus for manufacturing a plated wire rod.

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