KR20170028036A - Graphene-covered metal wire and manufacturing method thereof - Google Patents

Abstract

Disclosed are a graphene composite metal wire with improved reliability of high conductive properties by enabling the graphene composite metal wire to be a fine line, to be highly strengthened, and to be light weighted, and a manufacturing method thereof. According to the present invention, the graphene composite metal wire comprises: a metal wire including a copper alloy wire; and a graphene layer formed on the surface of the metal wire.

Description

[0001] Graphene-covered metal wire and manufacturing method [0002]

The present invention relates to a graphene composite metal wire and a method of manufacturing the same, and more particularly, to a graphene composite metal wire having high strength and light weight while improving the reliability of high conductivity.

Generally, metal wires or metal cables are made of metal and are used in a wide variety of fields such as electric power (for transmission and distribution), communication, control, equipment, and transportation.

Although such metal wires or metal cables are made of metal, which is a typical conductor, they are excellent in electrical conductivity. However, in some cases, when it is difficult to exhibit sufficient ability as a conductive material due to reduction in strength, corrosion, have. Therefore, in order to preserve or enhance the electrical and thermal properties of metal wires or metal cables, methods for developing alloy used or surface treatment (coating, etc.) of metal wires / metal cables have been studied.

Among the methods described above, forming a graphene on the metal wire / metal cable surface may be a good alternative. Graphene can transmit about 100 times more current at room temperature than copper per unit area, and its thermal conductivity is twice as high as that of diamond. Moreover, the mechanical strength is 200 times stronger than steel, and the flexibility is excellent, which is advantageous in that the conductivity is not deteriorated even if it is stretched or folded.

On the other hand, the method of synthesizing such graphene may vary, but a method of directly growing graphene using a peeling method (aka Scotch Tape method) or a metal catalyst is generally used. Among them, in the case of exfoliating, graphene and various layers of graphite are easily broken in the process of depositing on a substrate with scotch tape, which is basically expected to happen by chance, and graphene and graphite pieces are mixed disorderly . Therefore, when graphene is to be formed on the surface of the metal wire using the peeling method, graphene can not be uniformly formed.

Further, in the case of a method of directly growing graphene using a metal catalyst, graphene is grown by supplying a reaction source containing a carbon source onto the metal catalyst and heat-treating it at normal pressure. Therefore, there is a problem that a high temperature of 1,000 DEG C or more is required in the graphene manufacturing process.

FIG. 1 is a graph showing the production temperature in the case of the graphene direct forming production method, and FIG. 2 is a graph showing the tensile strength change of copper according to the temperature. Referring to FIG. 1, at the time of graphening, the decomposition temperature varies depending on precursors of hydrocarbons (gas, liquid, and solid), and CH ₄ gas is mainly used as a hydrocarbon precursor for producing high quality graphene. In the case of CH ₄ gas, the decomposition temperature is 900 ° C to 1,000 ° C or more. If the substrate on which graphene is synthesized is a metal, for example, copper, as shown in FIG. 2, the tensile strength of copper is drastically reduced according to the temperature, so that the mechanical strength of the substrate is lowered and the deterioration of physical properties is increased.

Further, since there is a problem in that it is difficult to completely remove contaminants present in the graphene formed on the metal catalyst in the process of removing the metal catalyst after the graphen growth using a method such as etching, There is a problem that it is not.

Therefore, in order to form graphene on the surface of a metal wire, it is required to develop a method capable of uniformly forming graphene at a relatively low temperature.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a graphene composite metal wire having high strength and light weight while improving the reliability of high-conductivity characteristics, and a method of manufacturing the same.

According to one aspect of the present invention, a graphene composite metal wire comprises a metal wire comprising a copper alloy wire; And a graphene layer formed on the surface of the metal wire.

The copper alloy wire may comprise an alloy metal selected from nickel (Ni), cobalt (Co), iron (Fe) and alloys thereof.

If the alloy metal is iron, the iron may be included in an amount of 2.5 wt% to 60 wt% based on the total weight of the copper alloy wire.

The copper alloy wire may include carbon fibers therein.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a metal wire including a copper alloy wire; Forming a carbon source layer including a carbon source on the surface of the metal wire; And forming a graphene layer on the surface of the metal wire by irradiating at least one of a microwave (Variable Frequency Microwave (VFM) or a white light (Intensity Pulse Light, IPL) .

Carbon sources include polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and self-assembled monolayer (SAM) Or the like.

The carbon source layer may comprise at least one of an ionic liquid and a polyionic liquid (PIL).

The graphene layer may be formed from the carbon source layer at a process temperature of 200 캜 to 300 캜.

As described above, according to the embodiments of the present invention, additional functions such as thermal conductivity, heat capacity, electromagnetic wave shielding / absorption, and the like are realized according to the combination of metal alloys of metal wires, .

Further, a multi-layered graphene layer can be formed, and the number of layers of the graphene layer can be easily adjusted, so that a graphene composite metal wire having desired thermal conductivity and thickness can be obtained.

In addition, it is possible to perform a low-temperature process by using microwave and IPL, and additionally, since a graphene layer can be formed at a lower temperature by using an ionic liquid or the like together with a carbon source, properties such as tensile strength of a metal wire including copper Can be excellently maintained, and it is possible to form a graphene composite metal wire which can be formed more finely and can be widely used.

FIG. 1 is a graph showing the production temperature in the case of the graphene direct forming production method, and FIG. 2 is a graph showing the tensile strength change of copper according to the temperature.
3 is a perspective view of a graphene composite metal wire in accordance with an embodiment of the present invention.
4 is a perspective view of a graphene composite metal wire according to another embodiment of the present invention.
5 is a graph showing the current density improvement efficiency of the graphene layer according to the copper diameter.
6 is a graph showing the current density improvement efficiency of the graphene layer depending on the graphene thickness (number of layers).

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention. It should be understood that while the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, The present invention is not limited thereto.

3 is a perspective view of a graphene composite metal wire in accordance with an embodiment of the present invention. The graphene composite metal wire 100 according to the present embodiment includes a metal wire 110 including a copper alloy wire; And a graphene layer 120 formed on the surface of the metal wire 110.

The graphene composite metal wire 100 of the present invention comprises a metal wire 110 comprising a copper alloy wire. The metal wire 110 comprises in particular a copper alloy wire, which may comprise an alloy metal selected from nickel (Ni), cobalt (Co), iron (Fe) and alloys thereof.

Copper alloy wire can be used in combination with other metals other than copper, which has excellent electrical conductivity. In consideration of mechanical strength and elasticity, Cu / Ag, Cu / Pd, Cu / Fe, Cu / / Ni alloy may be used.

When a metal other than copper is used for the copper alloy wire, various property improvements are possible. When Cu / Ag is used in the copper alloy wire, high-quality graphene synthesis can be performed in the synthesis of the graphene layer 120, and the control of the grain orientation of copper is easy and the size is increased. Alternatively, when Cu / Pd is used, the number of layers of the graphene layer 120 can be easily controlled, and chemical resistance and corrosion resistance are excellent. In addition, in the case of Cu / Fe and Cu / Ni, high temperature stability and high mechanical strength can be maintained, and heat dissipation characteristics based on magnetic material characteristics and electromagnetic shielding characteristics are enhanced. In the case of Cu / W, high temperature stability and high mechanical strength can be maintained, and high elasticity can be secured easily.

A graphene layer 120 is synthesized on the metal wire 110. The number of layers of the graphene layer 120 may vary depending on the use of the graphene composite metal wire 100 used. Accordingly, if the number of layers of the graphene layer 120 of the graphene composite metal wire 100 is freely adjusted, a graphene composite metal wire 100 suitable for various applications can be obtained. For example, when the content of copper in the copper alloy wire is low and the content of other alloy metal is high, the content of copper having high conductivity is low, so that the graphene layer 120 is formed in multiple layers to improve the conductivity of the graphene composite metal wire 100 .

Alternatively, when the copper content in the copper alloy wire is high, it is not necessary to improve the thermal conductivity. Therefore, it is preferable that the graphene layer 120 is formed of a layer for preventing metal oxidation and formed in a small number of layers. The number of layers of the graphene layer 120 formed on the metal wire 110 is preferably controlled in various ways. In order to form the multi-layered graphene layer 120, the substrate on which the graphene layer 120 is to be formed, It is preferable that the resin layer 110 contains a component having a high carbon melting property.

When the metal wire 110 contains a component having a high degree of carbon melting, the carbon from the carbon source is melted on the metal wire 110, and the metal wire 110 is adhered to the surface. Thus, multilayer graphene synthesis on the metal wire 110 is easy. Particularly, transition metals such as nickel (Ni), cobalt (Co), and iron (Fe) have a high degree of carbon melting so that the graphene layer 120 can be formed in multiple layers have. In the case of such a transition metal, it is preferable that the metal wire 110 includes a copper alloy wire since the number of layers of the graphene layer 120 to be formed on the surface can be controlled without reducing the electrical conductivity of the copper.

In a copper alloy wire, the alloy metal may be iron (Fe) in particular, and if the copper alloy wire contains iron, the strength is high and high mechanical strength can be maintained even at high temperatures. Therefore, since the mechanical strength of the metal wire 110 is high, it can be manufactured into a fine wire. The metal wire may have a diameter of 10 mu m to 200 mu m.

At this time, iron may be included in the copper alloy wire in consideration of the total strength of the graphene composite metal wire 100. That is, the iron may be contained in an amount of 2.5 wt% to 60 wt% based on the total weight of the copper alloy wire. Preferably, the iron may be included in an amount of 30 wt% to 60 wt% based on the total weight of the metal wire 110.

In addition, since the metal wire 110 having a high iron content shows a high strength even if the diameter thereof is small, the metal wire 110 used is reduced in weight. Therefore, the weight of the metal wire 110 is reduced by about 5% to 30% Effect can be obtained.

In particular, iron can impart electromagnetic wave and magnetic field shielding functions to the graphene composite metal wire 100 as a magnetic body. In addition, iron can also perform heat radiation functions due to its high thermal conductivity. Therefore, when the content of iron is high, the graphene composite metal wire 100 can form a highly reliable product that can be formed into a fine line having high strength, and can realize a function of shielding electromagnetic waves and magnetic fields as well as a heat dissipation function.

On the metal wire 110, a graphene layer 120 is formed. The graphene layer 120 can prevent oxidation of the metal contained in the metal wire 110, improve the electrical conductivity of the graphene composite metal wire 100, and increase the mechanical strength.

The graphene composite metal wire 100 according to the present invention may further include a magnetic material layer (not shown) between the metal wire 110 and the graphene layer 120. The magnetic body layer (not shown) is a magnetic layer and has a function of shielding an electromagnetic wave or a magnetic field. The magnetic layer (not shown) may include at least one of Ni, Fe, Co, M, Zn, Si, Mo, Nb and B.

4 is a perspective view of a graphene composite metal wire according to another embodiment of the present invention. The graphene composite metal wire 200 according to the present invention may further include a carbon fiber 230 inside the metal wire 210. If the carbon fiber 230 is further included in the metal wire 210, since the carbon fiber 230 is lightweight compared to the metal, the strength can be maintained even if the carbon fiber 230 is implemented with a finer diameter, Can be obtained.

5 is a graph showing the current density improvement efficiency of the graphene layer according to the diameter of the copper wire. When the graphene layer is formed on the copper wire, the copper wire formed with the graphene layer has an improved current density because it has the effect of improving the electrical characteristics such as the resistance of the copper wire, the thermal conductivity and the breakdown current density and delaying the oxidation of copper .

The current density of the graphene-coated copper wire can be calculated by the following equation (1).

[Equation 1]

Where J is the current density of the graphene coated copper wire, J 'is the current density of the copper wire, A is the cross-sectional area of the coated graphene, A' is the cross-sectional area of the copper wire, ), And σ 'is the conductivity of copper.

The current density improvement rate of a copper wire coated with a single graphene layer calculated according to Equation 1 is shown in Fig. As the diameter of the copper wire becomes smaller, it is expected that the effect of improving the current density by the single-layer coated graphene layer will be greatly increased.

4, when the carbon fiber 230 is included in the metal wire 210, the carbon fiber 230 has electrical conductivity higher than that of the metal, as compared with the case where only the metal wire 210 having the same diameter is included The overall electrical conductivity is low. However, the carbon fiber 230 exhibits a strength of 10 times or more at a weight of 1/3 to 1/4 of that of a metal such as copper or iron. Therefore, in the case of the graphene composite metal wire 200 including the carbon fibers 230, the weight of the carbon fiber 230 is less than that of the metal wire 110, It contains a metal layer on the outside and its electrical conductivity is complemented to exhibit lightweight high strength properties.

When the metal layer is thin, the metal wire 210 including the carbon fiber 230 inside the carbon fiber 230 is positioned between the carbon fiber 230 and the graphene layer 220. When the metal layer is thin, 230 and the graphene layer 220 is small. Therefore, when the graphene layer 220 is formed, the degree of carbon melting becomes higher due to the carbon fiber layer 230 below the metal layer, and the graphene layer 220 is likely to be formed in multiple layers. 6 is a graph showing the current density improvement efficiency of the graphene layer depending on the graphene thickness (number of layers). FIG. 6 shows the current density improvement efficiency according to the number of graphene layers, that is, the thickness of graphene, with respect to copper wires having diameters of 25 μm, 50 μm and 100 μm, respectively.

Referring to FIG. 6, when the graphene layer is multilayered, the current density of the metal wire is improved. The larger the diameter of the metal wire is, the smaller the effect of improving the current density is. However, the current density tends to increase when the number of graphene layers is increased. Therefore, since the graphene composite metal wire 200 including the carbon fibers 230 can easily form a multi-layered graphene layer 220 while the carbon fiber 230 is lightweight and high in strength, the graphene layer 220 The current density is improved, so that the disadvantage that the carbon fiber 230 has a lower electrical conductivity than the metal is complemented, and the electrical properties are also excellent.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: preparing a metal wire including a copper alloy wire; In order to form the graphene layer in the present invention, a step of forming a carbon source layer including a carbon source on the surface of the metal wire; And forming a graphene layer on the surface of the metal wire by irradiating at least one of a microwave (Variable Frequency Microwave (VFM) or a white light (Intensity Pulse Light, IPL) .

The metal wire includes a copper alloy wire, and may further include a magnetic material layer on the surface of the copper alloy wire. The copper alloy wire may be formed by a vacuum deposition method (eg, sputtering, thermal, e-beam evaporation, etc.), a plating method, an IPL application ink photocrystallization method, etc., and if a magnetic material layer is formed, a magnetic material layer can be formed in the same manner.

When the metal wire is formed, a carbon source layer containing a carbon source is formed on the surface of the metal wire. Examples of the carbon source that can be used in the present invention include polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), acrylonitrile butadiene styrene (ABS) Self-assembled monolayer (SAM), for example, is used as a polymer material. When a certain temperature is reached by heating, some of the chemical structure of the polymer is decomposed and the chemical bonds are rearranged. At this time, . Therefore, as the carbon source, a polymer capable of cyclizing the C-C bond by heating can be used.

The carbon source layer can be formed in such a manner that it is coated on the surface of the metal wire because the carbon source is mostly liquid. The carbon source layer may be formed on the metal wire by spin coating, dip coating, or spray coating of the carbon source. Spin coating is a method of coating the carbon source polymer on a metal wire or a plate material and then rotating the metal wire to coat the entire surface. The dip coating is a method of coating a surface of a metal wire or a plate material by dipping a metal wire or a plate material in the carbon source polymer, Spray coating is a method of spraying the carbon source polymer to coat the surface of the metal wire or plate. The thickness of the coating is not limited as long as graphene is formed, but it is preferably 100 nm or more and 1 占 퐉 or less. When the thickness of the coating is less than 100 nm, the graphene is not sufficiently formed. When the thickness exceeds 1 탆, the carbon source polymer is excessively used, which is not preferable for controlling the number of graphene layer layers.

The carbon source layer may include at least one of an ionic liquid and a polyionic liquid (PIL) in addition to the carbon source. An ionic liquid or a polymeric ionic liquid means a substance in which a cation and an anion exist in a liquid state due to the asymmetry of their size due to their asymmetry. Unlike a common salt, a liquid to be. Examples of cationic silver include Morpholinium, Imidazolium, quaternary ammonium, or quaternary phosphonium. Examples of anions include Br ^- , Cl ^- , NO ₃ ^- , BF ₄ ^- , or PF ₆ ^- Can be prepared by combining a large number of cations and anions. These ionic or polymeric ionic liquids are characterized by volatility, thermal stability, high ionic conductivity, broad electrochemical stability and low vapor pressure. When a carbon source layer is formed by mixing an ionic liquid or a polymeric ionic liquid with a polymer used as a carbon source, the stability of the carbon source layer is enhanced and formation at a lower temperature is possible at the time of forming a graphene layer to be synthesized thereafter.

When the carbon source layer is formed, at least one of a microwave (Variable Frequency Microwave, VFM) or white light (IPL) is irradiated to the metal wire on which the carbon source layer is formed. Irradiation of microwaves or IPL means applying heat to the carbon source layer as light irradiation. When the microwave or IPL is irradiated, the carbon source layer is formed as a graphene layer at a temperature of 600 DEG C or less. In particular, the microwave or IPL can selectively heat only the carbon source layer and does not adversely affect the physical properties of the metal wire therein.

At this time, when the carbon source layer contains an ionic liquid or a polymeric ionic liquid in addition to the carbon source, the temperature at which the graphene layer is synthesized from the carbon source layer may be lowered to 200 to 300 캜. That is, conventionally, in the process of synthesizing a graphene layer, the carbon source layer is formed at a process temperature of 900 to 1,000 ° C. to adversely affect physical properties such as tensile strength of a metal such as copper. However, When a wave or IPL is irradiated, a graphene layer may be formed at about 600 ° C. When the carbon source layer further contains an ionic liquid or a polymeric ionic liquid, the process temperature becomes lower, and a graphene layer is formed even at 300 to 600 ° C. So that the graphene layer can be formed without affecting the physical properties of the metal wire.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100 graphene composite metal wire
110 metal wire
120 graphene layer
130 carbon fiber

Claims (8)

A metal wire comprising a copper alloy wire; And
And a graphene layer formed on a surface of the metal wire.
The method according to claim 1,
The copper alloy wire may include:
Wherein the wire comprises an alloy metal selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), and alloys thereof.
3. The method of claim 2,
The above-
Iron,
Wherein the iron is contained in an amount of 2.5 wt% to 60 wt% based on the total weight of the copper alloy wire.
The method according to claim 1,
Wherein the copper alloy wire further comprises a carbon fiber inside the graphene composite metal wire.
Preparing a metal wire including a copper alloy wire;
Forming a carbon source layer including a carbon source on a surface of the metal wire; And
And forming a graphene layer on the surface of the metal wire by irradiating at least one of a microwave (Variable Frequency Microwave), VFM, and white light (IPL).
6. The method of claim 5,
The carbon source may include,
At least one of polyimide (PI), polymethylmethacrylate (PMMA), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and SAM (self-assembled monolayer) ≪ / RTI >
The method according to claim 6,
Wherein the carbon source layer
A method of making a graphene composite metal wire, the method comprising: at least one of an ionic liquid and a polyionic liquid (PIL).
8. The method of claim 7,
Wherein the graphene layer is formed from the carbon source layer at a processing temperature of 300 ° C to 600 ° C.

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