KR101344846B1 - Method for fabricating the active devices using electrohydrodynamic-jet printable metal nano-ink - Google Patents

Abstract

The present invention relates to a method for fabricating electronic devices using electrohydrodynamic (EHD) printing, which comprises the steps of: heating and stirring a first solution consisting of a metal precursor, an acid, an ammine, and a reducing agent to synthesize metal nanoparticles of which surface-oxide formation is controlled; making the metal nanoparticles formed in the previous step be dispersed in a non-aqueous solvent to prepare a conductive electrohydrodynamic-jet printable metal nano-ink composite; printing the conductive electrohydrodynamic-jet printable metal nano-ink composite on an insulating substrate; and heat-treating the insulating substrate on which the conductive electrohydrodynamic-jet printable metal nano-ink composite is printed.

Description

Method for Fabricating the Active Devices Using Electrohydrodynamic-jet Printable Metal Nano-ink

The present invention relates to a device fabrication method using metal nano inks for electrohydrodynamic printing (EHD printing).

In particular, the present invention relates to a new EHD printing metal nano ink composition for controlling the surface oxide film formation and to produce finer nano-sized particles, a metal conductive thin film using the same, and a method of manufacturing the device using the same.

The present invention also relates to a method of manufacturing a device using a metal conductive thin film having excellent conductivity.

In addition, the present invention improves the adhesion of the metal nanoparticles on the substrate, and does not affect the physical properties of the conductive high-conductivity EHD printing metal nano ink composition and a metal conductive thin film prepared therefrom and a thin film transistor, tooth panel, solar using the same A method for manufacturing a device such as a cell, a circuit board, and an RFID tag.

The development of metal nano inks for EHD printing containing metal nanoparticles is a very important technology for manufacturing thin film transistors, touch panels, solar cells, circuit boards, RFID tags, etc. containing conductive micro patterns. It is advantageous to simplify the process by printing on various substrates without using the complicated process of photolithography. In addition, the manufacturing cost can be drastically reduced due to the simplification of the process, and the wiring width can be miniaturized, making it possible to manufacture a highly integrated and highly efficient printed circuit.

In particular, in the case of a flexible printed circuit board that prints a circuit on a resin film, the flexible substrate itself is damaged while undergoing a complicated series of processes, such as applying, drying, exposing, etching and removing lithography. There is an urgent need for metal nano inks for EHD printing of monodisperse nanoparticles capable of drawing integrated circuits.

These metal nanoparticles are generally synthesized by a wet reduction method, and the surface oxide film is easily formed on the metal particles during the synthesis, resulting in deterioration of the conductivity in terms of conductivity.

Korean Patent Laid-Open Publication No. 2000-0018196 (Patent Document 1) discloses a method for preparing metal nanoparticles having oxidative stability against a conventional polar solvent, wherein metal ions are reacted with a reducing agent in the presence of a surfactant solution and an antioxidant And a wet reduction method for producing metal nanoparticles by reducing metal ions has been disclosed. In this method, a small nano-sized reactor is prepared by using a surfactant, and the particle size is controlled by a reduction reaction using a reducing agent. The particle size is easily controlled and stable. However, The surfactant and the antioxidant used for ensuring dispersion stability have problems such as a high resistance in wiring and metal film formation, and thus are unsuitable for use as an EHD printing ink.

In addition, the metal oxide film is formed on the surface of the resulting nanoparticles, so there is still room for improvement of the disadvantage that the conductivity of the metal is impaired. Therefore, an excellent EHD printing ink could not be manufactured. Could not get

Further, when the resulting nanoparticles are firmly adhered to the substrate, the use of a binder in the formation of the wiring and the metal film may increase resistance and insufficient conductivity.

Korean Patent Publication No. 2000-0018196

The present invention is to solve the above problems when synthesizing the metal nanoparticles for the solution process for EHD printing, to simplify the process, to synthesize the metal nanoparticles in which the formation of the surface oxide film that causes the characteristic degradation in terms of the expression of conductivity is completely controlled, An object of the present invention is to provide a method for manufacturing an EHD printing device capable of producing a low-cost conductive thin film having excellent conductivity by effectively removing capping molecules introduced to suppress surface oxide film formation.

In addition, another object of the present invention is to provide an ink having an improved stability of an ink, an EHD printing ink having a metal conductive thin film manufactured using the same, and a method of manufacturing an element using the same.

Another object of the present invention is to provide an EHD printing metal nano ink composition and a metal conductive thin film prepared therefrom, wherein the metal nanoparticles are stably fixed onto a substrate without sacrificing conductivity.

In order to achieve the above object, the present invention, the step of synthesizing the metal nanoparticles having controlled surface oxide film formation and more excellent conductivity, the metal nanoparticles for conductive EHD (electrohydrodynamic) printing using the metal nanoparticles It provides a metal nano ink composition for metal nano EHD printing comprising the step of preparing an ink composition.

In another aspect, the present invention, the step of synthesizing the metal nanoparticles of the surface oxide film formation is controlled, the step of preparing a conductive EHD printing metal nano ink composition that can be firmly fixed to the substrate using the metal nanoparticles, the metal nano ink composition for EHD printing It provides a method of manufacturing a device using a metal conductive thin film or pattern comprising the step of printing on an insulating substrate and the heat treatment of the substrate on which the ink composition is printed.

Hereinafter, the production method of the present invention will be described in detail as follows.

First, in the step of producing ink, the present invention is a method for producing a metal nano-ink for EHD printing by preparing a solution containing a metal precursor, an organic acid compound, an organic amine compound and a reducing agent simultaneously by heating and stirring the solution, A preliminary composition can be prepared.

The present invention also provides a means for producing a metal nano ink composition for conductive EHD printing having superior conductivity characteristics by heating the nanoparticles in order to produce nanoparticles in a non-hazardous component in the step of preparing the metal nano ink preform for EHD printing . In the above, the inert atmosphere means an atmosphere of inert gas such as nitrogen or argon, which is generally understood in the field, but is not limited to the above.

In addition, the present invention can produce a metal nano ink composition for conductive metal nano EHD printing by dispersing the prepared metal nano ink pre-composition for EHD printing in a non-aqueous solvent.

The present invention also relates to an ink for imparting a function of tightly adjusting metal nanoparticles on a substrate without impairing conductivity, including a compound of the following structural formula, when preparing the metal nano ink preliminary composition for EHD printing, and a metal conductive thin film prepared therefrom to provide. In addition, when the following compounds are used together, when sprayed from a fine print tip during electrohydrodynamic printing (EHD printing, electrohydrodynamic spraying method), foreign matter does not occur around the tip even with long-term use. It is also very good to be able to further increase the print quality. In the present invention, the following compounds may be added together with the metal precursor, or may be added when the resulting metal nanoparticles described below are dispersed in a nonaqueous solvent.

[Formula 1]

[XR ₁ ] _n [R ₂ ] _4-n Si

(In Formula 1, X is an amine group (-NH ₂₎ or a thiol group (-SH), R ₁ is (C ₀ -C ₁₇₎ alkyl group, R ₂ is (C ₁ -C ₁₇₎ alkyl or (C ₁ -C ₅ ) alkoxy group, and n is an integer of 1 to 3.)

(2)

[R ₁ ] - [R ₂ ] -SH

(In the formula 2, R ₁ is _{CH 3, CF 3, C 6} H 5, C 6 H 4 F, C 6 F 5, R 2 is _{(CH 2) n, (CF} 2) n, (C 6 H ₄ ) _n , and n is an integer from 1 to 17.)

Next, the manufacturing method of the metal conductive thin film using the electrostatic hydrodynamic printing method of the present invention will be described. In the present invention, when the metal conductive thin film is used as a thin film transistor, an electrode may be manufactured by printing.

As an example of device fabrication, when manufacturing a thin film transistor in the present invention, the manufacturing of the device having a graphene channel will be described as an example, but is not limited thereto.

First, graphene is synthesized and transferred as a channel material for fabricating a thin film transistor including a copper micro-conductive pattern as a source / drain electrode. As one example of forming a channel of graphene, graphene But the present invention is not limited thereto. For example, Cu foil is first loaded in a quartz CVD chamber at a degree of vacuum of about 10 to 700 mTorr (for example, 100 mTorr) for synthesis of graphene, and then, in a mixed atmosphere of hydrogen and inert gas (for example, H ₂ (E.g., 500 sccm) / Ar (200 sccm)) at a high temperature (for example, 1000 占 폚) of 300 to 1500 占 and a mixed gas of methane and argon is passed to synthesize graphene. The composition ratio of methane or argon is not limited as long as it is a well-known one. For example, graphene can be grown while flowing CH ₄ (500 sccm) / Ar (200 sccm) for about 5 minutes. A graphene channel can be formed by coating a base film on graphene grown for the transfer of the synthesized graphene film, removing the copper layer by etching and transferring the graphene onto the substrate. Thereafter, the transistor thin film can be manufactured by printing the source / drain electrodes using the metal nano ink for EHD printing and heat-treating the source / drain electrodes. The base film used for transferring the graphene film can be made of various materials such as a polyester, a polyamide, a polysulfone, a poly (methyl methacrylate) (PMMA) layer, and the like. . In the present invention, the substrate for manufacturing the transistor is not limited, but for example, a silicon substrate formed on the surface of SiO ₂ may be exemplified, but is not limited thereto. After the transfer onto the substrate, the device can be manufactured by removing the base film by an appropriate method such as dissolution.

A method of forming a thin film of an electrode or the like includes the steps of printing a metal nano ink composition for conductive EHD printing on an insulating substrate on an insulating substrate formed on an element unit such as an electron channel; And a step of heat treating the substrate on which the metal nano ink composition for conductive EHD printing is printed to form a metal conductive thin film, the device having the metal conductive thin film having excellent conductivity can be manufactured.

In the present invention, the metal precursor may be selected from the group consisting of metals such as copper, nickel, cobalt and aluminum, and alloys thereof, though not particularly limited. Examples of the metal precursor include copper, nickel And inorganic salts composed of nitrates, sulfates, acetates, phosphates, silicates and hydrochlorides of metal components such as cobalt, aluminum and alloys thereof, and the like.

In the present invention, the organic acid compound is not particularly limited, but may be at least one organic acid compound of straight chain, branched or cyclic having 6 to 30 carbon atoms, and may be one or more selected from saturated or unsaturated acids. Examples of the organic acid include oleic acid, lysine oleic acid, stearic acid, hyrodoxystearic acid, linoleic acid, amino decanoic acid, hydroxydecanoic acid, lauric acid, decenoic acid, undecenoic acid, Hydroxycarboxylic acid, hydroxycarboxylic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid,

The content of the organic acid compound according to the present invention is not particularly limited, but the molar ratio of the metal precursor to the organic acid compound is preferably in the range of 1: 0.2 to 4 in terms of the properties required in the present invention.

In the present invention, the organic amine compound has at least one form of straight chain, branched or cyclic having 6 to 30 carbon atoms, and may be one or two or more selected from saturated and unsaturated amines. Examples of the organic amine compound include hexylamine, heptylamine, octylamine, dodecylamine, 2-ethylhexylamine, 1,3-dimethyl-n-butylamine and 1-aminotridecane, but are not limited thereto In the present invention, the content of the organic amine compound is not particularly limited, but if the molar ratio of the organic amine compound to the metal precursor is 1: 0.2 molar ratio or more, there is no problem in the generation of the particle size or the stability of the ink. The organic amine compound may also be used in excess, surprisingly, even when used in excess, it has been found that the organic amine compound acts as a solvent and does not affect particle size control, particle reduction and ink stability. For example, it may be used at a molar ratio of 30 mol or more and 50 mol or more per mol of the metal precursor, but is not limited thereto.

The reducing agent may be one or more selected from a hydrazine-based, hydride-based, borohydride-based, sodium phosphate-based, and ascorbic acid.

More specifically, the reducing agent may be one or more hydrazine-based reducing agents selected from hydrazine, hydrazine anhydride, hydrazine hydrochloride, hydrazine sulfate, hydrazine hydrate and phenylhydrazine.

The reducing agent is not particularly limited as long as it can reduce the metal precursor to metal particles. For example, the reducing agent / metal precursor molar ratio may be in the range of 1 to 100 to obtain the desired effect of the present invention.

The reducing agent may be added to the synthesis solution prior to the heating and stirring steps and may be added after the heating and stirring steps. In the present invention, the heating step is not limited so long as reduction can be smoothly performed. For example, it is preferable to conduct the heating at 100 to 350 ° C., preferably 150 to 300 ° C., to improve the conductivity.

The non-aqueous solvent used for dispersing the metal nano ink pre-composition for EHD printing prepared in the present invention is not particularly limited, but includes, for example, an alkane having 6 to 30 carbon atoms, an amine, a toluene, a xylene, a chloroform, a dichloromethane, , Octadecene, chlorobenzene, dichlorobenzene, chlorobenzoic acid, and dipropylene glycol propyl ether, but is not limited thereto.

The amount of the non-aqueous solvent to be used can be variously adjusted depending on the viscosity of the ink and the application field thereof, so that the present invention is not limited thereto.

Although the reason for the simultaneous introduction of a metal precursor, an organic acid compound, and an organic amine compound is not clear in the present invention, the particle size of the metal precursor is reduced to improve the stability of the ink and to suppress the generation of a metal oxide film, To achieve the unexpected effect of. Although such an effect is not clear, it is considered that when the metal precursor is reduced by simultaneously introducing the acid component and the amine component, the metal precursor acts on the metal surface to protect the surface to inhibit the formation of metal oxides. The effect of decreasing the particle due to the simultaneous introduction is remarkably exhibited in the present invention.

Further, the present invention can achieve an unexpected effect of increasing the conductivity when heating in an oxygen-free atmosphere in the step of preparing metal nanoparticles. In the case of providing the metal nanoparticles in the oxygen-free atmosphere as described above, the metal oxide film is already suppressed in the atmosphere of oxygen or the like using the constitution of the present invention, but even the fine generation of the metal oxide film is controlled, do.

In the present invention, the heating atmosphere at the time of heat treatment of the thin film subjected to EHD printing (electrostatic hydraulics printing) may be at least one selected from the group consisting of atmospheric gas, non-oxygen atmosphere, hydrazine gas, reducing atmosphere, and carboxylic acid having 1 to 20 carbon atoms You can proceed.

The metal nano ink composition for conductive EHD printing in step b) may include 1 to 20 parts by weight of a dispersant based on 100 parts by weight of the metal nanoparticles.

The dispersant may be selected from one or more of an anionic compound, a nonionic compound, a cationic compound, a positive-working compound, a polymeric water-based dispersant, a polymeric non-aqueous dispersant, and a polymeric cationic dispersant.

Also, the metal conductive thin film produced by the manufacturing method according to the present invention is included in the scope of the present invention.

Also included in the scope of the present invention is a flexible circuit board comprising the metal conductive thin film according to the present invention.

The present invention relates to a device manufacturing method using the metal nano ink for EHD printing having excellent electrical properties.

In particular, the present invention can provide a novel EHD printing metal nano ink composition, a metal conductive thin film using the same, and a method of manufacturing a device using the same, wherein surface oxide film formation is controlled and finer nano-sized particles can be produced.

In addition, the present invention improves the adhesion of the metal nanoparticles on the substrate, and does not affect the physical properties of the conductive high-conductivity EHD printing metal nano ink composition and a metal conductive thin film prepared therefrom and a thin film transistor, touch panel, solar using the same A method of manufacturing a device such as a cell, a circuit board, or an RFID tag can be provided.

Further, since the metal conductive thin film using the ink according to the present invention is reduced by a reducing agent by simultaneously introducing a metal precursor, an organic acid, and an organic amine compound, the process is simple and efficient.

By using the ink of the present invention, formation of the metal oxide film on the surface at the time of production of the metal nanoparticles is suppressed, and high conductivity can be obtained. That is, the present invention has excellent electric conductivity because it has not only a process efficiency but also a surface oxide film which causes deterioration in characteristics in terms of conductivity in nanoparticle synthesis.

In addition, since the present invention additionally uses metal nanoparticles prepared with metal nanoparticles in a non-oxygen atmosphere, the device such as a manufactured thin film can provide a device having more excellent conductivity.

1 is a graph showing XRD of the copper nanoparticles prepared in Example 3,
2 is a graph showing XPS of the copper nanoparticles prepared in Example 3,
3 is a graph showing a conductivity of a conductive thin film according to a heat treatment temperature in an inert gas atmosphere prepared in Example 3,
4 is an SEM image of the conductive thin film according to the heat treatment temperature in the inert gas atmosphere prepared in Example 3,
5 is a graph showing the conductivity of a conductive thin film according to a heat treatment temperature in a hydrogen atmosphere prepared in Example 7. FIG.
6 is an SEM image of the conductive thin film according to the heat treatment temperature of the hydrogen atmosphere prepared in Example 7. FIG.
7 is a SEM photograph of the nickel nanoparticles prepared in Example 10
8 is XRD data of the nickel particles prepared in Example 10. Fig.
9 is a structural diagram of a device fabricated in Example 14;
FIG. 10 is an optical micrograph (scale bar: 10 μm) of an EHD printed fine pattern using a carbide nozzle having a diameter of 5 μm prepared in Example 14. FIG.
11 is an AFM photograph of a fine pattern EHD printed using a carbide nozzle having a diameter of 5 ㎛ prepared in Example 14
12 is a Raman spectrum of graphene of Example 14
13 is a transfer electrical characteristic of the thin film transistor prepared in Example 14

Hereinafter, the production method of the present invention will be described in detail.

First, an aspect of the present invention is a method of manufacturing a metal oxide nanoparticle comprising: synthesizing metal nanoparticles whose surface oxide film formation is controlled; Preparing a metal nano ink composition for conductive EHD printing using the metal nanoparticles; And preparing the device by EHD printing using the composition.

According to another aspect of the present invention, there is also provided a method of fabricating a semiconductor device, comprising: synthesizing metal nanoparticles by controlling formation of a surface oxide film and reducing by heating in an inert atmosphere; Preparing a metal nano ink composition for conductive EHD printing using the metal nanoparticles; And preparing the device by EHD printing using the composition.

According to another aspect of the present invention, a metal precursor, an organic acid compound, and an organic amine compound are simultaneously added to reduce the metal precursor with a reducing agent, thereby providing a highly conductive EHD printing metal nano ink composition in which formation of a surface oxide film is suppressed.

According to another aspect of the present invention, when a metal precursor, an organic acid compound, and an organic amine compound are simultaneously added and the metal precursor is heated and reduced by a reducing agent, the metal nano ink composition for printing high conductivity EHD printing is further improved by heating in an inert atmosphere. to provide.

In addition, the present invention is prepared from the ink and the ink to give the function of firmly adjusting the metal nanoparticles on the substrate without damaging the conductivity by respectively or mixing the compounds of the following structural formula in the preparation of the metal nano ink composition for EHD printing metal nano EHD printing By providing a thin metal conductive thin film, the manufactured device has more excellent durability. In addition, there is little generation of aggregates generated at the tip when printing fine EHD ink to provide an ink composition that can be used for a long time. In the present invention, the following compounds may be added together with the metal precursor, or may be added when the resulting metal nanoparticles described below are dispersed in a nonaqueous solvent. In the present invention, the content of the following compounds is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.3 part by weight based on 100 parts by weight of the metal precursor.

[Formula 1]

[XR ₁ ] _n [R ₂ ] _4-n Si

(In Formula 1, X is an amine group (-NH ₂₎ or a thiol group (-SH), R ₁ is (C ₀ -C ₁₇₎ alkyl group, R ₂ is (C ₁ -C ₁₇₎ alkyl or (C ₁ -C ₅ ) alkoxy group, and n is an integer of 1 to 3.)

(2)

[R ₁ ] - [R ₂ ] -SH

(In the formula 2, R ₁ is _{CH 3, CF 3, C 6} H 5, C 6 H 4 F, C 6 F 5, R 2 is _{(CH 2) n, (CF} 2) n, (C 6 H ₄ ) _n , and n is an integer from 1 to 17.)

The present invention relates to a process for preparing a metal nano ink composition for electroconductive nano-EHD printing, which comprises dispersing the synthesized metal nanoparticle solution in a non-aqueous solvent, But also includes more.

In another aspect, the present invention provides a method for producing a metal conductive thin film prepared by printing a non-aqueous solvent dispersed high conductive EHD printing metal nano ink composition on a substrate.

In addition, another aspect of the present invention provides a method for manufacturing a device having a metal conductive thin film comprising the step of heat-treating the substrate after printing the high conductivity EHD printing metal nano ink composition on a substrate.

Specifically, the present invention is a high conductivity EHD printing metal nano ink composition

a) synthesizing metal nanoparticles whose surface oxide film formation is controlled by simultaneously adding a solution containing a metal precursor, an organic acid compound, an organic amine compound and a reducing agent, heating and stirring the mixture;

b) dispersing the metal nanoparticles produced in step a) in a nonaqueous solvent to prepare a metal nano ink composition for conductive EHD printing.

The present invention also encompasses that the step a) is a step of heating in an inert atmosphere.

In addition, the method of manufacturing a device having a metal conductive thin film of the present invention

a) synthesizing metal nanoparticles having controlled surface oxide film formation by heating and stirring a solution containing a metal precursor, an organic acid compound, an organic amine compound and a reducing agent at the same time;

b) dispersing the metal nanoparticles produced in step a) in a non-aqueous solvent to prepare a metal nano ink composition for conductive EHD printing;

c) printing the metal nano ink composition for conductive EHD printing on an insulating substrate; And

d) heat treating the insulating substrate on which the EHD printing metal nano ink composition is printed to form a metal conductive thin film;

The present invention also provides a method for producing a metal conductive thin film including the metal conductive thin film.

Also, the method for producing a metal conductive thin film of the present invention

a) synthesizing metal nanoparticles whose surface oxide film formation is controlled by heating and stirring a solution containing a metal precursor, an organic acid compound, an organic amine compound and a reducing agent in an inert atmosphere;

b) dispersing the metal nanoparticles produced in step a) in a non-aqueous solvent to prepare a metal nano ink composition for conductive EHD printing;

c) printing the metal nano ink composition for conductive EHD printing on an insulating substrate; And

d) heat treating the insulating substrate on which the EHD printing metal nano ink composition is printed to form a metal conductive thin film;

It provides a device manufacturing method having a metal conductive thin film comprising a.

Hereinafter, each step of the method of manufacturing a metal nanoink composition for a high conductivity EHD printing and a method of manufacturing a device according to the formation of a metal conductive thin film according to the present invention will be described in more detail.

The step a) is a step of synthesizing metal nanoparticles, and a step of synthesizing metal nanoparticles whose surface oxide film formation is controlled by heating and stirring a solution containing a metal precursor, an acid, an amine and a reducing agent, Metal ions of the metal precursor are reduced to form metal nanoparticles. In this case, metal nanoparticles in the form of capsules in which acid and amine are capped on the surface of the metal nanoparticles are formed, and the metal nanoparticles can be prevented from being transformed into metal oxides even when they are left in the air.

The present invention enables the reduction reaction at 100 DEG C or higher by adding the reducing agent. In the case where an organic acid compound or an organic amine compound is not contained at the same time as in the present invention, a metal oxide is generated on the surface and the conductivity is inevitably lowered. However, according to the present invention, such a problem can be eliminated.

It has also been found that the present invention can achieve the effect of obtaining metal particles having better conductivity when the metal nano-particles are heated and reduced in an inert atmosphere.

In the step a), the metal precursor may be selected from one or more selected from the group consisting of copper, nickel, cobalt, aluminum and alloys thereof.

More specifically, one or more inorganic salts selected from nitrates, sulfates, acetates, phosphates, silicates and hydrochlorides of metals selected from the group consisting of copper, nickel, cobalt, aluminum and their alloys may be used.

In the step a), the acid has at least one form of straight chain, branched or cyclic having 6 to 30 carbon atoms, and may be one or two or more selected from saturated or unsaturated acids.

More concretely, there can be mentioned oleic acid, lysine oleic acid, stearic acid, hyadroxystearic acid, linoleic acid, aminodecanoic acid, hydroxydecanoic acid, lauric acid, decenoic acid, undecenoic acid, palmitoleic acid, hexyldecano Hydroxycarboxylic acid, hydroxycarboxylic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid, succinic acid,

The metal conductive thin film according to the present invention is characterized in that the molar ratio of the metal precursor to the acid is 1: 0.2-4.

If the molar ratio of the precursor to the acid is less than 0.2, the capping is not completely performed and oxidation occurs on a part of the metal that is not capped. If the molar ratio exceeds 4, the capping material does not react all, It is unable to recover in the form of capped particles.

In step a), the amine has at least one form of straight chain, branched or cyclic having 6 to 30 carbon atoms, and one or more of saturated and unsaturated amines can be selected.

More specifically, it may be selected from hexylamine, heptylamine, octylamine, dodecylamine, 2-ethylhexylamine, 1,3-dimethyl-n-butylamine and 1-aminotridecane. The content of the amine is preferably 0.2 mol or more, preferably 1 to 50 mol, more preferably 5 to 50 mol, per mol of the metal precursor, and in the case of the upper limit, the organic amine compound may act as a non-aqueous solvent and is therefore not limited .

In the step a), the hydrazine-based reducing agent may be one or two or more selected from hydrazine, hydrazine anhydride, hydrazine hydrochloride, hydrazine sulfate, hydrazine hydrate and phenylhydrazine. In addition, other hydrides; Borohydride systems including tetrabutylammonium borohydride, tetramethylammonium borohydride, tetraethylammonium borohydride, and sodium borohydride; Sodium phosphate system; And ascorbic acid; One or more of them can be selected and used. Among them, the hydrazine-based reducing agent is most preferable because of its strong reducing power.

In the step a), the metal nanoparticle synthesis step is not limited but is preferably performed at 100 to 350 ° C, more preferably 140 to 300 ° C, more preferably 150 to 250 ° C, in consideration of the reduction efficiency.

The present invention enables a reduction reaction at 100 ° C or higher.

In addition, since the reduction reaction can be performed at a high temperature of 100 ° C or higher, the production rate and yield of metal nanoparticles can be increased. Also, the hydrazine-based reducing agent is generally better because it has a better reducing power compared to other reducing agents due to its excellent reducing power.

In the synthesis of the metal nanoparticles of step a), the composition ratio of the first solution will be described in detail. The composition ratio is not particularly limited, but when considering the capping efficiency of the metal nanoparticles, the acid is 0.2 to 4 moles, the amine is 0.2 or more, preferably 0.2 to 50, more preferably 5 to 20 moles per mole of the metal precursor ≪ / RTI >

The reducing agent may include a reducing agent / metal precursor molar ratio of 1 to 100. If the molar ratio is less than 1, metal ions of the metal precursor are not completely reduced. If the molar ratio is more than 100, excess metal ions may not be added to the metal precursor and the reduction rate may not be affected.

The metal nanoparticles containing the metal nanoparticles may be obtained only by separation methods such as washing and recovery using a centrifugal separation method.

The metal conductive ink according to the present invention is a simple and simple process in which a metal precursor, an organic acid compound, an organic amine compound and a reducing agent are added at once to perform a reaction. The metal conductive ink is generated by capping the metal oxide nanoparticles or capping only organic acids with metal nanoparticles As a technique for suppressing the generation of an oxide film, it is possible to synthesize metal nanoparticles whose surface oxide film is completely controlled.

At this time, the reducing agent may be partially added in advance in the synthesis of the metal nanoparticles according to the present invention to promote the reduction of the metal ion of the metal precursor. In this case, especially, the hydrazine-based reducing agent is present in the solution before the reaction to remove the oxygen which causes the oxidation of the metal nanoparticles, thereby further suppressing the formation of the surface oxide film.

Further, the present invention can achieve an unexpected effect of increasing conductivity when heating in an incombustible atmosphere in the step a) of producing metal nanoparticles. In the case of providing the metal nanoparticles in the inert atmosphere as described above, it is presumed that the metal oxide film is already suppressed in the oxygen atmosphere using the constitution of the present invention, but even the fine generation of the metal oxide film is controlled to further increase the conductivity.

Next, step b) will be described.

Step b) is a step of preparing a metal nano ink composition for conductive EHD printing using the metal nanoparticles prepared in the step a) and a non-aqueous solvent.

In this case, the nonaqueous solvent is not particularly limited, but is preferably an alkane, amine, toluene, xylene, chloroform, dichloromethane, tetradecane, octadecene, chlorobenzene, dichlorobenzene, chlorobenzoic acid, Propylene glycol propyl ether, and the like. Such a conductive ink composition is not particularly limited, but may be prepared by dispersing by a method such as stirring and milling.

In addition, the metal nano ink composition for conductive EHD printing may use a dispersant if necessary.

The dispersant may be at least one selected from the group consisting of fatty acid salts (soaps), alpha -sulfo fatty acid ester salts (MES), alkylbenzenesulfonic acid salts (ABS), linear (straight chain) alkylbenzenesulfonic acid salts (LAS), alkylsulfuric acid salts Low molecular weight anionic compounds such as salts (AES) and alkylsulfuric triethanol; Low molecular weight non-ionic compounds such as fatty acid ethanol amides, polyoxyalkylene alkyl ethers (AE), polyoxyalkylene alkyl phenyl ethers (APE), sorbitol and sorbitan; Low molecular weight cationic compounds such as alkyltrimethylammonium salts, dialkyldimethylammonium chlorides and alkylpyridinium chlorides; Low molecular weight positive-working compounds such as alkylcarboxybetaine, sulfobetaine and lecithin; Polymeric dispersants such as formalin condensates of naphthalene sulfonic acid salts, polystyrene sulfonic acid salts, polyacrylic acid salts, copolymer salts of vinyl compounds and carboxylic acid monomers, carboxymethylcellulose, and polyvinyl alcohol; Polymeric non-aqueous dispersing agents such as polyacrylic acid partial alkyl esters and polyalkylene polyamines; And polymeric cationic dispersants such as polyethyleneimine and aminoalkyl methacrylate copolymers; and the like.

Specifically, EFKA4008, EFKA4009, EFKA4010, EFKA4015, EFKA4046, EFKA4047, EFKA4060, EFKA4080, EFKA7462, EFKA4020, EFKA4050, EFKA4055, EFKA4400, EFKA4401, EFKA4402, EFKA4403, EFKA4300, EFKA4330, EFKA4340, EFKA6220, EFKA6225, EFKA6700, EFKA6780, EFKA6782, EFKA8503 (EFKA ADDITIVES BV products), TEXAPHOR-UV21, TEXAPHOR-UV61 (Cognis Japan or wrong to manufactured products), DisperBYK101, DisperBYK102, DisperBYK106, DisperBYK108, DisperBYK111, DisperBYK116, DisperBYK130, DisperBYK140, DisperBYK142, DisperBYK145, DisperBYK161, DisperBYK162 , DisperBYK163, DisperBYK164, DisperBYK166, DisperBYK167, DisperBYK168, DisperBYK170, DisperBYK171, DisperBYK174, DisperBYK180, DisperBYK182, DisperBYK192, DisperBYK193, DisperBYK2000, DisperBYK2001, DisperBYK2020, DisperBYK2025, DisperBYK2050, DisperBYK2070, DisperBYK2155, DisperBYK2164, BYK220S, BYK300, BYK306, BYK320, BYK322 , BYK325, BYK330, BYK340, BYK350, BYK377, BYK378, BYK380N, BYK410, BYK425, and BYK430 (manufactured by Big Chemical Japan Co., ), FTX-207S, FTX-212P, FTX-220P, FTX-220S, FTX-228P, FTX-710LL, FTX-750LL, ftergent 212P, 245P, 245P, 245P, 250P, 251, 710FM, 730FM, 730LL, 730L, 730LS, 750MT, 750M, and more. MEGAFACE F-477, Megapack 480SF, and Megapack F-482 (manufactured by DIC Corporation) can be exemplified, but the present invention is not limited thereto.

The dispersant may be used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the metal nanoparticles. When the content of the dispersant is used within the above range, it is possible to prevent a sufficient dispersion effect and a lowering effect of conductivity.

Next, step c) will be described.

Step c) is a step of printing on the substrate the metal nano ink composition for conductive EHD printing prepared in step b).

Though the printing thickness is not limited, it is preferable that the thickness after heat treatment is 0.1 to 50 占 퐉.

In the present invention, the substrate may be an organic or inorganic semiconductor material, an organic or inorganic insulating material, or the like, but is not limited thereto. Examples include, but are not limited to, SiO2, a Si layer, glass, polyimide, polyethylene terephthalate, polysulfone, polyethylene naphthalate, or polycarbonate. In the present invention, when the compound of formula (1) or (2) is used as a compound for firmly fixing to the substrate, the effect of fixing to the substrate is remarkably increased.

Finally, step d) will be described.

The step d) is a step of forming a metal conductive thin film by heat-treating the insulating substrate on which the metal nano ink composition for EHD printing is printed, wherein the metal conductive thin film from which the material capped on the metal nanoparticles is removed is formed according to the heat treatment gas atmosphere and temperature. do.

At this time, the heat treatment temperature is not limited and can be performed within the range of 150 to 350 ° C.

The heat treatment in the step d) may be carried out by any one method selected in an inert gas, a hydrazine gas atmosphere, a hydrogen atmosphere, and a carboxylic acid atmosphere having 1 to 20 carbon atoms. Particularly, the reason why heat treatment is performed in the hydrogen atmosphere is not clear, but it is particularly preferable because a thin film having sufficient conductivity can be obtained in a short time.

The metal conductive thin film produced by the above-described production method described so far is within the scope of the present invention.

In addition, a device including a flexible circuit board including the metal conductive thin film is included in the scope of the present invention.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1

73.63 g of octylamine, 3.52 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 0.2. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. The copper nanoparticles obtained were found to be copper particles free of copper oxides as a result of XRD measurement. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The prepared EHD printing metal nano ink composition was coated on an insulating substrate to have a thickness of 2 μm, and then heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

[Example 2]

73.63 g of octylamine, 17.58 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on an insulating substrate so as to have a thickness of 2 μm (a carbide nozzle having a diameter of 2 μm with a hydrophobic coating was connected to the ink containing chamber and the syringe pump). The ink composition prepared using the EHD printing equipment was printed while applying a voltage.), 250 ° C., and heat-treated in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

[Example 3]

73.63 g of octylamine, 25.1 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1.42. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The copper nanoparticles thus synthesized were washed and recovered by centrifugal separation, and the finally obtained copper nanoparticles of about 80 nm were dispersed in toluene to prepare a metal nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on the insulating substrate as in Example 1 to 2 μm, and heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and shown in Table 1, Fig. 1, Fig. 2 and Fig.

Example 4

73.63 g of octylamine, 70.3 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 4. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on the insulating substrate as in Example 1 to 2 μm, and heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

[Example 5]

73.63 g of octylamine, 3.52 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 0.2. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed to 2 μm on an insulating substrate as in Example 1, and thermally treated at 250 ° C. and 5% H 2 to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 2.

[Example 6]

73.63 g of octylamine, 17.58 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed to 2 μm on an insulating substrate as in Example 1, and thermally treated at 250 ° C. and 5% H 2 to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 2.

[Example 7]

73.63 g of octylamine, 25.1 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1.42. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed to 2 μm on an insulating substrate as in Example 1, and thermally treated at 250 ° C. and 5% H 2 to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 2, FIG. 5, and FIG.

[Example 8]

73.63 g of octylamine, 70.3 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 4. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed to 2 μm on an insulating substrate as in Example 1, and thermally treated at 250 ° C. and 5% H 2 to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 2.

[Example 9]

73.63 g of octylamine, 3.52 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 0.2. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. The copper nanoparticles obtained were found to be copper particles free of copper oxides as a result of XRD measurement. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) and 0.1 part by weight of amino-octyltrimethylsilane were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to obtain a copper conductive EHD A metal nano ink composition for printing was prepared. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on the insulating substrate as in Example 1 to 2 μm, and heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

[Example 10]

71.84 g of oleamine, 4.23 g of oleic acid, 29 g of phenylhydrazine and 5 g of nickel acetoacetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 0.73. After making an inert atmosphere using nitrogen gas, the nanoparticles were synthesized by inducing a reduction reaction of nickel ions by increasing the synthesis temperature to 240 ℃. The synthesized nickel nanoparticles were washed and recovered by centrifugation. As a result, it can be seen that the produced nickel particles are uniform nickel particles as shown in FIG. 7 and are pure nickel metal particles not formed with nickel oxide as shown in FIG.

[Example 11]

71.84 g of oleamine, 8.37 g of oleic acid, 29 g of phenylhydrazine and 5 g of nickel acetoacetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1.42. After the inert atmosphere was made using nitrogen gas, the temperature was raised to 240 ° C., which induces a reduction reaction of nickel ions to synthesize nickel nanoparticles. The synthesized nickel nanoparticles were washed and recovered by centrifugation. As a result, it was confirmed that pure nickel particles having uniform particles were formed as in Example 9.

Comparative Example 1

73.63 g of octylamine, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The copper nanoparticles thus synthesized were washed and recovered by centrifugal separation. Finally, the resulting copper nanoparticles were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. The size of the copper nanoparticles produced was as large as about 180 nm. After adding 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) based on 100 parts by weight of toluene, a metal conductive ink composition for copper conductive EHD printing having a uniform dispersed phase was prepared through ball milling and ultrasonic irradiation. It was. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on the insulating substrate as in Example 1 to 2 μm, and heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

[Comparative Example 2]

70.3 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 4. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered by centrifugal separation, and finally the copper nanoparticles obtained were dispersed in toluene to prepare a metallic nano ink composition for conductive EHD printing. 20 parts by weight of copper nanoparticles and 1 part by weight of a polymer non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper nano ink composition for copper conductive EHD printing having a uniform dispersed phase Respectively. The metal nano ink composition was printed using an EHD printing apparatus, and then printed on the insulating substrate as in Example 1 to 2 μm, and heat-treated at 250 ° C. in an Ar atmosphere to prepare a conductive thin film.

The presence and the conductivity of the thus-prepared conductive thin film were measured and are shown in Table 1.

TABLE 1 Experimental results of Examples 1 to 4 and 9 and Comparative Examples 1 and 2 (heat treatment atmosphere: Ar)

[Table 2] Examples 5 to 8 Test results (heat treatment atmosphere: hydrogen atmosphere)

[Example 12]

The metal conductive thin films were prepared by the same method as in Example 3 except that the heat treatment temperatures were changed to 150 ° C., 200 ° C., 250 ° C., 300 ° C. and 350 ° C., respectively. The conductivity of the thus-prepared metal conductive thin film is shown in FIG.

[Example 13]

The metal conductive thin films were prepared by the same method as in Example 7 except that the heat treatment temperatures were changed to 150 ° C, 200 ° C, 250 ° C, 300 ° C and 350 ° C, respectively. The conductivity of the thus-prepared metal conductive thin film is shown in FIG.

As shown in Table 1, it is possible to synthesize metal nanoparticles whose surface oxide film formation can be controlled by the addition of a reducing agent and simultaneous addition of an acid and an amine at the synthesis of metal nanoparticles. When only an amine not containing an acid is added, it can be confirmed that an oxide film is formed and the conductivity of the conductive thin film is lowered even though a reducing agent is added. An XRD graph of copper nanoparticles prepared according to Example 3 of the present invention is shown in FIG. As a result of XRD analysis, it can be confirmed that no oxide film was formed. However, in the production of a conductive thin film, even a slight amount of oxide film not detected by XRD analysis results in increasing the specific resistance of the conductive thin film.

Therefore, XPS analysis was performed for more accurate analysis, and an XPS graph of copper nanoparticles prepared according to Example 3 is shown in FIG. As a result of the XPS analysis, no peaks due to Cu-O chemical bonding are observed at all, and peaks having symmetry due to Cu-Cu chemical bonding are observed, indicating that the formation of the oxide film is completely controlled. The copper nanoparticles thus prepared have a characteristic of showing conductivity through a heat treatment step.

Example 12 is an experiment measuring the conductivity according to the heat treatment temperature under an Ar gas atmosphere, as confirmed through the conductivity graph of Figure 3 and the SEM image of the temperature of Figure 4, 6 × 10 ³ S / at a temperature of 250 ℃ A conductivity of cm can be obtained, and heat treatment at a temperature of 250 ° C. or higher is required to improve conductivity. In Example 12, the conductivity was measured according to the heat treatment temperature in the atmosphere of 5% hydrogen gas. Through the graph of FIG. 5 and the SEM image of FIG. 6, excellent conductivity can be obtained at a temperature of 200 ° C. or more Respectively. It was confirmed that the hydrogen gas atmosphere at the same temperature was more efficient because the conductivity was higher.

Example 14 Fabrication of Thin Film Transistor

As a channel material, graphene was synthesized and transferred to fabricate a thin film transistor including a copper micro-conductive pattern as a source / drain electrode. For graphene synthesis, the Cu foil was loaded in a quartz CVD chamber at a vacuum of 100 mTorr and then heated to 1000 degrees C in an atmosphere of H ₂ (500 sccm) / Ar (200 sccm). The graphene was grown while flowing CH ₄ (500 sccm) / Ar (200 sccm) for 5 minutes and cooled to room temperature in an Ar atmosphere. A poly (methyl methacrylate) (PMMA) layer was coated to transfer the synthesized graphene film. Since after etching the Cu layer, press in contact with the PMMA layer on the Si substrate is overcorrected ping SiO ₂ formed on the surface So was transferred to a pin overcorrected ping Si substrate is a SiO ₂ of 300 nm thickness formed on the surface. After the transfer, the PMMA layer was removed with acetone, and the patterned mask was masked on the graphene and the graphene of the unmasked portion was removed using oxygen plasma to form a graphene channel layer.

 Copper nanoparticles were synthesized to produce conductive copper ink for source / drain electrodes. 73.63 g of octylamine, 25.1 g of oleic acid, 87.4 g of phenylhydrazine and 10.38 g of copper acetate were added to prepare a synthesis solution. The molar ratio of oleic acid / copper acetate is 1.42. Nitrogen gas was used to make an inert atmosphere, and then the temperature was raised to 150 캜, which is the synthesis temperature, to induce the reduction reaction of copper ions to synthesize copper nanoparticles. The synthesized copper nanoparticles were washed and recovered using a centrifugal method, and finally the copper nanoparticles obtained were dispersed in propylene glycol propyl ether to prepare a conductive ink composition. 4 parts by weight of copper nanoparticles and 1 part by weight of polymeric non-aqueous dispersant (DisperBYK130) were added to 100 parts by weight of toluene, followed by ball milling and ultrasonic irradiation to prepare a copper conductive ink composition having a uniform dispersed phase.

Carbide nozzles having a diameter of 5 μm with a hydrophobic coating were printed using an EHD printing equipment connected to a chamber containing the ink and a syringe pump while applying voltage. The gap between the substrate and the nozzle was maintained at 100 μm, and the printed fine pattern was heat-treated under 300 ° C. and 5% H 2 atmosphere.

9 shows the structure of the manufactured thin film transistor, and FIGS. 10 and 11 show optical micrographs of the copper conductive pattern having a fine line width of 5 μm. In addition, FIG. 12 shows the characteristics of the manufactured graphene having a G-to-2D peak intensity ratio of about 0.5 and a D-to-G peak intensity of less than 0.1 and a half width of about 30 cm ⁻¹ for a 2D band. . Looking at the electrical properties of the manufactured transistor, as shown in Figure 13 it can be seen that it has excellent characteristics showing a hole (electron) mobility of 1,280 (660) cm2 / Vs.

Claims (10)

a) synthesizing metal nanoparticles whose surface oxide film formation is controlled by heating and stirring a first solution containing a metal precursor, an acid, an amine and a reducing agent;
b) dispersing the metal nanoparticles produced in step a) in a solvent to prepare a metal nano ink composition;
c) printing the metal nano ink composition on a patterned substrate with an electrostatic printing apparatus; And
d) heat-treating the printed insulating substrate to form a metal conductive thin film to manufacture a device;
Method for manufacturing an electronic device by electrostatic hydraulic printing comprising a. The method of claim 1,
The metal precursor is one or two or more selected from the group consisting of copper, nickel, cobalt, aluminum and alloys thereof. The method of claim 1,
The acid has a form of at least one of linear, branched and cyclic having 6 to 30 carbon atoms, one or two or more selected from saturated or unsaturated acids, the method of manufacturing an electronic device by electrostatic printing. The method of claim 1,
The molar ratio of the metal precursor and the acid is 1: 0.2 to 4. The manufacturing method of an electronic device by electrostatic printing, characterized in that. The method of claim 1,
The amine has a form of at least one of linear, branched and cyclic having 6 to 30 carbon atoms, one or two or more selected from saturated and unsaturated amines. The method of claim 1,
Wherein the reducing agent is one or more selected from hydrazine-based, hydride-based, borohydride-based, sodium phosphate-based and ascrobic acid electrostatic-hydraulic printing method of manufacturing an electronic device. The method of claim 1,
The metal nanoparticle synthesis step is a method of manufacturing an electronic device by electrostatic printing, characterized in that carried out at 100 ~ 240 ℃. The method of claim 1,
The heat treatment of step d) is a method for manufacturing an electronic device by electrostatic hydrodynamic printing in an inert atmosphere or hydrogen atmosphere. The method of claim 1,
Step a) is a method of manufacturing an electronic device by electrostatic hydraulic printing is heated in an inert atmosphere 10. The compound according to any one of claims 1 to 9,
The conductive EHD printing metal nano ink composition comprises 0.001 to 1 part by weight of one or two or more compounds selected from Formula 1 and Formula 2 with respect to 100 parts by weight of the metal precursor.
[Chemical Formula 1]
[XR ₁ ] _n [R ₂ ] _4-n Si
(In Formula 1, X is an amine group (-NH ₂₎ or a thiol group (-SH), R ₁ is (C ₀ -C ₁₇₎ alkyl group, R ₂ is (C ₁ -C ₁₇₎ alkyl or (C ₁ -C ₅ ) alkoxy group, and n is an integer of 1 to 3.)
(2)
[R ₁ ] - [R ₂ ] -SH
(In the formula 2, R ₁ is _{CH 3, CF 3, C 6} H 5, C 6 H 4 F, C 6 F 5, R 2 is _{(CH 2) n, (CF} 2) n, (C 6 H ₄ ) _n , and n is an integer from 1 to 17.)

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