KR20150026359A

KR20150026359A - Method for manufacturing conductor coated with a carbon atomic-layered film

Info

Publication number: KR20150026359A
Application number: KR20130105089A
Authority: KR
Inventors: 소순주
Original assignee: 소순주
Priority date: 2013-09-02
Filing date: 2013-09-02
Publication date: 2015-03-11

Abstract

Suggested in the present invention is a manufacturing method for a conductor coated with graphene, which can effectively and easily perform synthesis and evaporation of graphene on the surface of a wire. The manufacturing method for a conductor comprises: a step of preparing a conductor with a surface composed of catalyst metal with a biaxial structure in single orientation; and a step of coating by synthesizing graphene on the surface of the conductor using a chemical vapor deposition (CVD) method.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a conductive layer coated with a graphene coating,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a conductor having a high conductivity, and more particularly, to a method of manufacturing a conductor in which a graphene coating layer is formed.

It is widely known that a carbon monoclonal structure of a two dimensional planar structure called graphene has very good electrical properties, for example, very high conductivity.

The reason why the conductivity is improved when the graphene is coated on the conductor is because the carbon single-layer film itself has a high conductivity of 200,000 cm ² / V · sec up to 200,000 cm ² / V · sec, This is also due to the edge conduction effect. This is a phenomenon in which electrons move through a surface in a semiconductor whose conduction is dominated by an edge channel. This is evidenced by an experiment in which a voltage is generated at a temperature difference when one side of a semiconductor circuit is heated.

As described above, graphene is a two-dimensional planar body of a monolayer, originally having an energy gap in a two-dimensional plane, and charges can not flow in a two-dimensional plane. However, a conduction channel may be formed at the boundary of the two-dimensional plane, even in a quantum hall state where the hole voltage is quantized in the two-dimensional plane. This is because the periphery (for example, vacuum), which is in contact with the two-dimensional plane, acts as a potential well and the Landau levels are bent so that the Landau levels existing under the Fermi energy in the plane This is because the Fermi energy is raised at the boundary of the plane. That is, states are created that allow conduction along the boundary of the plane. The current flowing in the state of the edge of the quantum hole (hereinafter referred to as the edge state) does not dissipate and always travels only in one direction along the boundary of the sample. For this reason, when the Hall voltage is quantized, the longitudinal resistance becomes zero. Here, the filling factor ν corresponding to the Hall voltage is the number of conduction channels present in a given edge state and is a function of the charge density. The conduction direction of the edge state depends on the direction of the magnetic field and the type of charge Lt; / RTI > It has recently been experimentally proven that edge states are present in graphene and edge states are similar to those in conventional two-dimensional electromagnetic fields when degeneracy is not yet broken at relatively low magnetic fields.

Here, the edge state is n = 0 and corresponds to the right edge. This Landau level is filled with electrons and holes by half, so that the closer to the edge of the sample, the higher the level is divided into the electron-filled part and the pore-filled part. At this time, the edge effect of graphene breaks the K and K 'valley symmetry, and electrons and holes are filled in different valleys at graphene edges. Therefore, if the actual spin degeneracy is broken first, there is an edge state flowing in opposite directions near n = 0, and each edge state becomes 100% spin polarization. At this time, the measured longitudinal resistance at n = 0 becomes metallic, which is called a quantum-Hall ferromagnet state. For this reason, graphene shows the same conductivity as metal, despite being a carbon compound.

In order to apply this graphene to a conductor, various researches on a coating method for a conductor are required, and studies on construction of a system for cheap mass production for industrial use are needed.

KR 10-2013-0051418 A

Electron transport properties of graphene, Physics and high technology, July / August 2009, pp. 11-13 Seo, Soon Ae, Attractiveness of Graphene: Report of New Physics, Physics and Advanced Technology, December 2010, pp. 9-10

The present invention provides a method of coating a conductor with graphene.

The present invention is suitable for mass production of conductors, and suggests a method for effectively synthesizing / coating graphene on a conductor.

A method for producing a conductor according to the present invention comprises:

Preparing a conductor having a catalytic metal surface of bi-axial structure of single orientation; And

And synthesizing graphene on the surface of the conductor by chemical vapor deposition (CVD).

According to the present invention, in the step of preparing the conductor, the bi-axial structure can be formed by drawing out the conductor.

According to a specific embodiment of the present invention, the conductor may be a wire, and the bi-axial structure may be formed by drawing the wire.

According to a specific embodiment of the present invention, the wire is a copper wire, and the drawing applies a volume reduction rate of 95% or more.

According to a specific embodiment of the present invention, the draw of the conductor is a cold draw, and after the draw, the conductor may be annealed.

According to a specific embodiment of the present invention, the wire rod may have a multi-layer structure having at least one coating layer covering an extension line and an extension line. The extension line and the coating layer may be formed of the same or different materials. The outer cover is formed of catalytic metal.

According to a specific embodiment of the present invention, the coating and deposition of graphene on the wire can be accomplished by disposing a first roller and a second roller across the graphene synthesis chamber, It is possible to perform a roll-to-roll process in which graphene synthesis is performed on the wire while supplying and recovering the graphene composite chamber.

According to a specific embodiment of the present invention, a pretreatment process including any one of cleaning and preheating may be performed before coating the graphene on the wire.

According to a specific embodiment of the present invention, the feeding of the wire can be made in the horizontal direction or the vertical direction, whereby the positions of the first and second rollers on the graphene synthesis chamber and both sides thereof are determined.

The present invention provides a method for effectively and easily synthesizing and depositing graphene on a wire rod. Since the graphene-formed wire has a very low resistance, it is suitable for manufacturing of electric / electronic parts requiring low resistance and resistance to direct current, and for manufacturing large power lines. The present invention can produce a graphene coated wire with high efficiency at a low cost.

FIG. 1 (a) is a cross-sectional view of a conductor coated with a graphene layer on a single core wire according to an embodiment of the present invention.
FIG. 1 (b) is a cross-sectional view of a conductor coated with a grappling layer on a core wire coated with a coating layer according to another embodiment of the present invention.
2 is an overall process flow diagram of one embodiment of a method for manufacturing a conductor according to the present invention.
FIG. 3A is an optical microscope photograph showing a polycrystalline structure of a surface annealing a drawn wire before coating graphene.
FIG. 3B is an image obtained by electron back-scattered diffraction (EBSD) after annealing a drawn copper wire according to the manufacturing method of the present invention.
Figure 4 is a schematic block diagram of a horizontal roll-to-roll graphene deposition system in accordance with one embodiment of the present invention.
Figure 5 is a schematic block diagram of a vertical roll to roll graphene deposition system in accordance with another embodiment of the present invention.

Hereinafter, a method of manufacturing a conductor according to the present invention will be described with reference to the accompanying drawings.

The conductor according to the present invention is an object having electrical conductivity and is provided with a catalyst metal surface having a biaxial structure in which crystal grains are arranged in the (001) direction on the surface thereof, that is, a single orientation in one direction Means an electrical material. As a representative example of such a conductor, a wire of a single body, or a wire of a multi-layer structure in which at least one coating layer of a core is covered.

1 shows a cross-sectional structure of a wire rod 10 which can be produced by the manufacturing method of the present invention.

1A is a cross-sectional view of a conductor 10a coated with a graphene layer 12 on a single core wire 11 and FIG. 1B is a cross-sectional view of a conductor wire 10a coated with a coating layer 13 on the core wire 11. FIG. (10b) coated with a grappling layer (12).

1, the surface of the wire rod, that is, the surface where the graphene is synthesized, is made of a catalytic metal such as copper, and the surface thereof has a biaxial structure in which crystal grains are oriented in one direction.

Such a biaraxial structure can be formed by drawing a wire rod, and particularly, a cold drawing is preferable. When the pre-pellet used in the manufacturing method of the present invention, for example, a copper wire is cold-drawn at a large sectional reduction rate of 95% or more, dislocation or displacement, which is a crystal structure defect of the material, It is necessary to reduce the crystal structure defects. Then, when the heating is continued at a high temperature, the surface texture of the copper wire becomes a bi-axial aggregate state in which the atomic arrangements are all in the same orientation, with the energy of defects in the crystal being the driving force. The polycrystalline material originally has a different orientation depending on the crystal grains, and its boundary becomes a crystal grain boundary. In the bi-axial group structure, there is a small angle difference in the orientation between crystal grains. This can be confirmed by EBSD (Electron Backscattering Diffraction Technique) attached to a scanning electron microscope. According to one embodiment of the present invention, a drawing method is applied as a method for forming a texture having a one-directional orientation on the surface of a wire rod. However, other surface treatment methods may also provide orientation to the surface of the wire rod, and thus the present invention is not limited by any particular method of forming surface texture to have orientation in one direction.

FIG. 3A shows an optical microscopic structure of a surface annealing copper wire having a thickness of 50 microns. It can be seen that the drawn copper wire before annealing has a polycrystalline structure.

Fig. 3B is a result obtained after heating at 1000 DEG C for 20 minutes in an atmosphere containing 10 sccm of hydrogen in a vacuum chamber as an image obtained by EBSD. It can be seen that the orientation of copper is all (001) converted into a single direction bi-axial structure.

Coating of the graphene layer on the wire is performed by synthesis of graphene on the surface of the wire. At this time, the surface of the wire or the skin layer is coated with a known catalyst metal such as Ni, Co, Fe, Pt, Au Cu, Al, Cr, Cu, Mg, Mn, Rh, Si, Ta, Ti, W, U, V and Zr. In one embodiment of the present invention, Cu is used. In the multilayered wire, the core wire is a metal such as aluminum, iron, or stainless steel. Such a wire rod may include a core material or an intermediate coating layer made of an insulating material inside thereof except for the outermost coating layer made of catalytic metal.

A preferred material for the wire, particularly the outermost coating layer or surface is a catalytic metal for graphene synthesis, preferably copper (Cu). As is well known, graphene is formed as a single layer because of its low carbon solubility.

The synthesis or coating of graphene on the wire surface is performed by a chemical vapor deposition method, in which a carbon-based gas and a hydrogen gas are used as a source gas, and a hydrocarbon gas, more specifically, methane gas, is used as a carbon-based gas.

The chemical vapor deposition method applied to the manufacturing method and system of the present invention can be classified into a thermal chemical vapor deposition (T-CVD), a rapid thermal chemical vapor deposition (RTCVD), a plasma chemical vapor deposition (PECVD), inductively coupled plasma enhanced chemical vapor deposition (ICPCVD), metal organic chemical vapor deposition (MOCVD), and low pressure chemical vapor deposition low pressure chemical vapor deposition (LPCVD), and atmospheric pressure chemical vapor deposition (APCVD). On the other hand, a laser heating method can be applied for the synthesis of graphene. The present invention is not limited by a specific method of synthesizing graphene on the surface of the wire rod.

2 is an overall process flow diagram of one embodiment of a method for manufacturing a conductor according to the present invention.

Step 1: First, a base material for forming a wire material is prepared (S1), and a base material is pulled out to obtain a wire material having a desired orientation in one direction (S2). Cold drawing is preferably used for drawing the base material. Such drawing may be performed by a separate wire manufacturing process, and may be supplied to the graphene synthesis or coating line by wrapping the wire rods in a drawn state so as not to touch the air.

2. Move to the step of preprocessing the drawn wire (S3).

3. In the pre-treatment step (S3), the wire is annealed to align the grain of the wire in one direction to form a bi-axial structure having grain orientations in one direction in the wire (S31).

4. In the preprocessing step (S3), as a pretreatment step before the annealing of the wire rod, cleaning is carried out in order to remove foreign substances adhering to the surface of the wire rod (S32). The cleaning of the wire includes plasma treatment or plasma annealing or laser treatment or annealing.

According to this process, the annealing and the cleaning can be performed at the same time. That is, when annealing the wire, high-temperature energy is applied to the wire, at which time the impurities are thermally decomposed and removed from the surface of the wire.

5. In the pre-treatment step (S3), after the wire material is cleaned, the wire material is preheated for effective synthesis of graphene (S33). The annealing, cleaning, and preheating processes in the preprocessing step S3 may be performed independently of each other, and the annealing and cleaning may be performed simultaneously with the plasma treatment or the laser treatment.

Preheating or annealing may be preheated to a temperature equal to or lower than the temperature at which chemical vapor deposition can easily occur on the wire. This preheat temperature is, for example, from about 400 ° C to about 1200 ° C, or from about 500 ° C to about 1060 ° C, or from about 600 ° C to about 1000 ° C, at which the hydrocarbon gas can decompose. In the preheating, when the pre-treatment by inductively coupled plasma, RF plasma, or the like, especially the preheating, decomposes the hydrocarbon gas from low temperature to high energy, it is suitable for the case where graphene is synthesized at 660 ° C. or less. According to the above-described heat treatment method, there is no need to prevent the oxidation of the catalyst metal, which has been applied in the conventional graphene synthesis.

5. The wire rod is introduced into a graphene synthesis chamber where a source gas is injected at a high temperature to synthesize or grow graphene on the surface of the wire rod as a catalyst to obtain a desired graphene coated wire rod or conductor (S4). In the present invention, preferably, the surface of the wire material on which graphene synthesis takes place is copper (Cu), and has a bi-axial structure as described above.

The reaction gas used in graphene synthesis may be hydrocarbon alone or may contain an inert gas such as helium, argon, or the like. The reaction gas may contain hydrogen as a reducing agent. The hydrogen can be used to keep the surface of the substrate clean and to control the gas phase reaction, and the supply amount is 1 to 100 sccm. It is difficult to expect reduction effect and impurity removal effect at a supply amount of less than 1 sccm because it requires pretreatment of the same effect. If it is more than 100 sccm, the etching effect is excessive and the metal member of the graphene deposition equipment is eroded.

When the graphene is synthesized, the hydrogen regulates the growth rate of the graphenes. Therefore, the amount of hydrogen is determined depending on the kind of the hydrocarbon. The hydrogen in the reaction gas can be used in an amount of 1 to 50% by volume, 40% by volume, more preferably 10 to 30% by volume.

The hydrocarbons that can be used in graphene synthesis include carbon monoxide, carbon dioxide, methane, ethane, ethylene, ethanol, methanol, acetylene, propane, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene, And the technical scope of the present invention is not limited by a specific reaction gas.

If the internal temperature is controlled within a certain range while supplying the reaction gas to the graphene synthesis chamber in the graphene synthesis chamber, the hydrocarbons in the reaction gas are physically adsorbed on the surface of the wire material having a biaxial texture, And the carbon components generated at this time are bonded at the surface of the wire to form a hexagonal carbon monolayer having a two-dimensional structure, that is, a graphene layer, as a single layer or multiple layers. The suitable temperature range for decomposing hydrocarbons during the catalytic reaction is about 400 ° C to 1200 ° C.

The graphene synthesis or coating process as described above can be continuously performed on a wire rod to be fed and recovered in a so-called roll-to-roll manner in a process chamber.

All elements included in the roll-to-roll type graphene synthesis system according to the present invention are located in one process chamber and include an annealing chamber as a pretreatment system for plasma or laser processing to perform the pretreatment steps described above in the process chamber, A graphene synthesis or deposition chamber is prepared by a CVD method in which graphene synthesis is performed.

FIG. 4 is a conceptual diagram of a horizontal roll-to-roll graphene deposition (coating) system 100 according to one embodiment of the present invention, and FIG. 5 is a conceptual diagram of a vertical graphene coating system.

4, an annealing chamber 102 for pretreating the wire 10 in the process chamber 101 and a deposition chamber 103 for graphening and coating the surface of the pretreated wire 10 are provided. The annealing chamber 102 and the deposition chamber 103 are in the form of a tube and subjected to a desired heat treatment and deposition, respectively. Here, when the preheating process of the wire rod 10 is performed by the annealing chamber 102, the temperature of the annealing chamber 102 may be equal to or lower than the temperature of the deposition chamber 103.

The wire 10 is supplied from the first roller 104 provided on one side (right side in the figure) of the annealing chamber 102 and the deposition chamber 103 and is supplied to the annealing chamber 102 and the deposition chamber 103 The passed wire 10 is wound on the second roller 105 provided on the other side (left side in the drawing). The first roller 104 and the second roller 105 can be rotated in one or both directions mutually as a winding element of the wire 10 so that the two rollers can wind or unwind the wire. For example, when the wire 10 fed from the first roller 104 is totally or partially heat-treated and graphene deposition is completed, the first roller 104 and the second roller 105 are rotated in the opposite direction Performing pin deposition or forming a protective layer or an insulating layer on the first deposited graphene layer, and repeating this process one or more times. A stable wire rod 10 protection and guiding means is required inside the process chamber 101 for maintaining atmospheric pressure or vacuum in order to damage or scratch the surface of the wire rod and the graphene layer synthesized on the surface of the wire rod. For example, between the first roller 104 and the second roller 105, surface damage of the wire rod 10 is prevented and the wire rod 10 is supported to prevent warping or deformation of the wire rod 10, One or more guide rollers 106 and 107 for minimizing the thermal gradient of the wire rod 10 may be provided at arbitrary positions. In addition, a jig for guiding the stable feeding of the wire 10 may be provided. Among the guide rollers 106 and 107, the guide roller 106 provided at the outlet side of the deposition chamber 103 may have a wire cooling structure for cooling the wire. It is possible to eliminate a separate cooling device for cooling the wire rod wound on the second roller 105. The deposition system 100 according to the present invention is characterized in that the supply of the wire 10, the heat treatment (pre-treatment), the deposition of the graphene, the cooling and the recovery of the wire 10 are performed in one process chamber 101, It is possible to prevent contact with oxygen or nitrogen and to eliminate the problems caused thereby. A heating device or heating jackets 105a and 105b are provided on the body of the annealing chamber 102 and the deposition chamber 103 for example to control the temperature within each chamber 103 and 104 within a certain range . On the other hand, on the outlet side of the deposition chamber 103, a quenching device, for example, a coolant supply device or a conduction device of the wire roughened with graphene can be selectively provided. In the case of the conduction device, 106). As a result, the guide roller 106 reduces the temperature of the wire rod 10 by cooling the wire rod 10 at a properly controlled cooling rate. By doing so, it becomes advantageous to suppress or prevent degeneration or decomposition of the graphene coated on the wire rod 10.

The vertical roll-to-roll graphene deposition system 100 shown in FIG. 5 will now be described. In the longitudinal roll-to-roll graphene deposition system 100 of FIG. 5, the wire rod is vertically fed, and correspondingly, the first and second rollers 104 and 105 are arranged vertically and the annealing chamber 102, and a deposition chamber 103. As shown in Fig. The movement of the wire 10 can be made from the bottom up as shown in the figure and according to another embodiment it can be moved from top to bottom or from bottom to top and from top to bottom according to another embodiment, A protective layer or an insulating layer may be formed on the once-deposited graphene layer by supplying a different composition gas to the CVD apparatus.

In the graphen deposition system 100 shown in FIGS. 4 and 5 described above, the interior of the process chamber 101 or the deposition chamber 103 is movable based on vacuum and pressure, and when the system 100 is enlarged, The process chamber 101 maintains atmospheric pressure and maintains a vacuum atmosphere in the annealing chamber 102 and the deposition chamber 103. A reducing gas or a hydrocarbon gas necessary for graphen deposition (synthesis) Is supplied through the gas introducing portion.

A gas introduction part (not shown) may be provided in the deposition chamber 103 and the annealing chamber 102 as in a general structure. On the other hand, a heat-resistant barrier may be provided at an outlet or an end of the annealing chamber 102. Examples of the material include a ceramic having excellent heat resistance such as alumina, magnesia, zirconia, silicon carbide, graphite, sapphire glass, quartz, Boron nitride, and gold mica. The annealing chamber 102 may be provided with a gas inlet (not shown) for supplying hydrogen gas.

Further, a gas exhaust unit (not shown) may be provided to exhaust the gas supplied to the annealing chamber 102 or the deposition chamber 103 after the reaction is completed, The gas concentration can be kept uniform. And can be designed to be communicated with the flexible connecting member inside.

The number of the gas nozzles for supplying the reaction gas to the deposition chamber 103 may be one or more, and accordingly, a plurality of the gas nozzles are installed in the deposition chamber 103 as necessary. If several nozzles are installed, it is possible to improve graphene synthesis or uniformity of deposition on the surface of the wire rod. Such a gas nozzle is preferably arranged in the deposition chamber so that graphene can be uniformly synthesized on all the surfaces of the wire, for example, nozzles are arranged on both sides of the wire in the deposition chamber.

According to an embodiment of the present invention, a gas introducing portion (not shown) for introducing the above-described reducing gas formed between the first roller 104 and the annealing chamber 102 can be provided. The reducing gas injected through the first gas introducing portion is, for example, a hydrogen gas as described above, and is not limited thereto. In the graphene deposition system according to the present invention as described above, various gas introduction units are provided, including a reducing gas, a source gas for graphene synthesis, hydrogen, argon, nitrogen and helium gas for purifying the process chamber A purge gas introduction pipe and a gas discharge pipe such as a mixture gas thereof are installed at a given position according to a given purpose, and the specific arrangement structure of these elements does not limit the technical scope of the present invention.

&Lt; Example 1 >

In this embodiment, a copper wire was used as the wire, which was 210 ppm of oxygen, 5 ppm of Bi, 10 ppm of Sn, and the remaining Cu, which was cold drawn to give a bi-axial structure in the (001) direction. The drawn copper wire was annealed in an atmosphere of hydrogen at 10 sccm for 5 minutes in a vacuum process chamber heated to 1000 ° C, and then maintained in an atmosphere of 30 sccm of methane and 10 sccm of hydrogen for 15 minutes. As a result of this process, a multi-layered graphene layer was synthesized on the copper wire surface.

&Lt; Example 2 >

The copper wire used in Example 1 was annealed in an atmosphere of 10 sccm of argon and 10 sccm of hydrogen in a vacuum process chamber heated at 1000 캜 for 5 minutes and induced graphene synthesis for 30 minutes in a mixed atmosphere of 30 sccm of methane and 15 sccm of hydrogen for 30 minutes. As a result, a graphene layer with a 2D / G ratio close to 1 was synthesized on the copper wire surface in the Raman spectrum graph.

&Lt; Example 3 >

The copper wire used in Example 1 was annealed in an atmosphere of 5 sccm of hydrogen in a vacuum process chamber heated to 1000 캜 for 30 minutes and induced graphene synthesis in an atmosphere of 15 sccm of methane and 15 sccm of hydrogen for 30 minutes. As a result, a Raman spectrum as shown in FIG. 5 was obtained. 6 shows a Raman spectrum graph on a scanning electron microscope photograph of graphene synthesized on copper lines. As a result of comparison of the Raman peaks, it can be seen that graphenes of the sp2 structure are formed when the peak is clearly observed at the G peak of 1580 cm -1 and the 2D peak of 2700 cm -1. The electric wire thus obtained has a conductivity of 100% or more based on the standard interconnection established by the International Electrical Association.

The wire rod produced by the method as described above can be used as a wiring material in various fields requiring low resistance and high current density. For example, a transformer, an inductor, a high-voltage power line, and the like.

The wire rod manufactured by the present invention can be applied as a coil wire for a transformer. The transformer consists of a primary winding, a secondary winding, and a coil composed of two windings of different windings. When electricity is supplied to one of the windings by the electromagnetic induction action, the magnetic flux proportional to the current Occurs. The magnetic flux is proportional to the material of the conductor, the thickness, and the number of turns of the wire. Therefore, as the conductivity of the transformer wires increases, the strength of the magnetic flux increases as more turns can be obtained from the same volume by using thinner wires.

The coil has a proportional relationship between the voltage value of the input voltage applied to the primary winding and the product of the magnetic flux density induced in the core and the effective cross sectional area of the magnetic flux of the core due to the input voltage, The product of the density and the effective sectional area of the magnetic flux of the core is proportional to the voltage value of the output voltage induced in the secondary coil.

However, if the cross-sectional area of the wire is large, the length of the winding is shortened and the magnetic flux passing through the core becomes small. Therefore, the above- The voltage that can be input and output is limited.

Therefore, when it is desired to reduce the thickness of the transformer while maintaining the effective cross-sectional area of the magnetic flux of the core, it is necessary to use a coil having a minimized DC resistance. As the wire becomes thinner, the resistance becomes larger, which means an increase in copper loss. Heat generation and heat accumulation due to copper loss hinders the stability of the transformer, and countermeasures against it are a challenge in the research of transformers.

The wire rod produced in accordance with the present invention has an extremely low DC resistance and is therefore suitable for application in miniaturized transformers. The wire rod manufactured according to the present invention is suitable not only for a power transformer but also a power line used for long-distance transmission and a communication cable for signal transmission.

The power line applicable to the present invention may be a single copper wire or a multi-layer wire drawn and drawn with aluminum coating on a wire to enhance the stiffness or a multi-layer wire drawn with a copper coating on an aluminum coating.

The surface of such a wire is a surface of a catalytic metal capable of vapor deposition or synthesis of graphene, and this surface has a bi-axial structure having orientation in one direction according to the present invention. The surface treated wire rod is coated with graphene by the above-described method, in particular, a roll-to-roll method.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of claim of the present invention is not limited within the scope of the detailed description, but will be defined by the following claims and technical ideas thereof.

10: wire rod
100: Grain deposition system
101: Process chamber
102: Pretreatment (annealing) chamber
103: Deposition chamber
104: first roller
105: second roller
106, 107: guide rollers

Claims

Preparing a conductor having a catalytic metal surface of bi-axial structure of single orientation; And
Coating a graphene on the surface of the conductor using chemical vapor deposition (CVD), and coating the graphene on the surface of the conductor.

The method according to claim 1,
Characterized in that in the step of preparing the conductor, the bi-axial structure is formed by drawing of the conductor.

The method according to claim 1,
Wherein the conductor is a wire and the biaraxial structure is formed by drawing of the wire material.

The method according to claim 1,
Wherein the conductor has a single body or a multilayer structure having extensions and coatings and the surface on which the graphene is synthesized is a catalytic metal.

The method according to claim 1,
Wherein the catalyst is copper. &Lt; RTI ID = 0.0 > 8. < / RTI >

4. The method according to any one of claims 1 to 3,
The graphene coating on the conductor is performed by a roll-to-roll process, which is supplied and recovered by first and second rollers provided in the process chamber, wherein the process chamber includes a deposition &Lt; / RTI > wherein a chamber is provided.

The method according to claim 6,
Characterized in that an annealing chamber is provided in the process chamber for pre-treating the conductor.

Wherein at least one of annealing, cleaning, and preheating the conductor is performed in the annealing chamber.