KR20160010359A - Fabrication Method of Conductive Metal Film with Light Sintering - Google Patents

Abstract

A method for producing a conductive metal thin film according to an embodiment of the present invention comprises the following steps: a) producing a conductive ink composition containing metal nanoparticles capped with a capping layer in which a metal core includes organic acid, a non-aqueous organic binder, and a non-aqueous solvent; b) producing a coating membrane by coating an insulation substrate with the conductive ink composition; and c) producing a conductive metal thin film by irradiating light at a level from strength of light in which a non-aqueous organic binder remains in the coating membrane to maximum light strength or less.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a conductive metal thin film using light sintering,

The present invention relates to a method for manufacturing a conductive metal thin film, and more particularly, to a method for manufacturing a conductive metal thin film having excellent electrical conductivity without damaging a substrate even if the substrate has a low upper limit temperature, To a method of manufacturing a conductive metal thin film having an extremely excellent bonding force with a substrate.

Research on manufacturing electronic components and energy application parts using various printing processes based on inks and pastes containing metal nanoparticles is one of the megatrends of current technology development.

The ink containing the metal nanoparticles can be printed on various substrates through a single printing process such as screen printing, inkjet printing, gravure offset printing and reverse offset printing, without using a complicated process of photolithography Thereby simplifying the process. 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.

The Applicant has noticed that the conductivity of a metal wiring is deteriorated by a surface oxide film existing in metal nanoparticles in a metal nanoparticle-based ink, thereby providing a method of synthesizing metal nanoparticles in which formation of a surface oxide film is completely controlled Korean Patent Publication No. 2013-0111180). However, in Korean Patent Laid-Open Publication No. 2013-0111180 filed by the present applicant, the ink containing the metal oxide nanoparticles controlled by the surface oxide film is applied to thermo-plasticize, and in order to impart bulk characteristics through such thermo-plasticization, Temperature heat treatment at a high temperature of 300 DEG C or higher for a long time of 2 hours. Such a high-temperature heat treatment for a long time makes it difficult to utilize a flexible polymer substrate that is spotlighted as a substrate of a flexible element, and further, it is disadvantageous in a roll-to-roll continuous process having excellent commercial properties.

As a result of intensive research for a long time for a method of producing a conductive metal thin film using a metal nano-particle ink in which the formation of a surface oxide film is controlled, the Applicant has found that the upper limit of the process temperature The present inventors have completed the present invention by developing a method of manufacturing a conductive metal thin film having excellent electrical conductivity comparable to bulk without deteriorating the substrate even at an extremely low temperature of 100 ° C or less and at the same time having a remarkable bonding force with the substrate.

Korea Patent Publication No. 2013-0111180

The present invention can manufacture a conductive metal thin film having excellent electrical conductivity without damaging a substrate even if the substrate has a low upper limit of the process temperature and can be effectively applied to a flexible part because of its extremely excellent bonding force with a substrate, To a process for producing a conductive metal thin film which can be manufactured in a very short time in the atmosphere, can realize a roll-to-roll process and is excellent in commerciality, and can simplify a process and reduce manufacturing cost.

A method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention includes the steps of: a) forming a conductive ink composition containing metal nanoparticles, a non-aqueous organic binder, and a non-aqueous solvent, the metal core being capped with a capping layer containing an organic acid Producing; b) applying a conductive ink composition to an insulating substrate to form a coating film; And c) irradiating the coating film with light so as to satisfy the following relational expression 1 to produce a conductive metal thin film.

(Relational expression 1)

I _LS ? I _c

In the relational expression 1, I _LS is the intensity of the light irradiated to the coating film, and I _c is the maximum intensity of the intensity of light in which the non-aqueous organic binder remains in the conductive metal thin film.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, in step c), light may be irradiated so as to satisfy the following relational expression 1-1.

(Relational expression 1-1)

I _LS & le; 2.6 (J / cm < ² &

In the relation 1-1, the definition of I _LS is the same as the relation 1.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the average diameter of the metal nanoparticles may be 20 to 300 nm.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, light including a wavelength band of 200 to 800 nm may be continuously irradiated in step c).

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, light may be continuously irradiated for 1 to 2 msec in step c).

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the non-aqueous organic binder may include polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), a self-crosslinkable acrylic resin emulsion, A copolymer of C1-C10 alkyl (meth) acrylate and an unsaturated carboxylic acid such as ethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl cellulose, hydroxy cellulose, methyl cellulose, nitrocellulose, ethyl cellulose, styrene butadiene rubber (SBR) Gelatin, thixoton, starch, polystyrene, polyurethane, a resin containing a carboxyl group, a phenolic resin, a mixture of ethylcellulose and a phenolic resin, an ester polymer, a methacrylate polymer, A self-crosslinking (meth) acrylic acid copolymer, a copolymer having an ethylenic unsaturated group, an ethylcellulose-based, acrylate-based, City water may be selected landmark and at least one or more mixtures thereof.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the conductive ink composition may include 0.05 to 5 parts by weight of a non-aqueous organic binder and 20 to 800 parts by weight of a non-aqueous solvent ≪ / RTI >

In the method of manufacturing a photo-sintered conductive metal thin film according to an exemplary embodiment of the present invention, the conductive ink composition may further include one or more selected nanostructures in the conductive nanowire, the conductive nanotube, and the conductive nanorod.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the thermal conductivity of the nanostructure may be 50 W / mK or more.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the aspect ratio of the nanostructure may be 10 to 10000.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the nanostructure may include single-walled carbon nanotubes, double walled carbon nanotubes, thin multi-walled ) Carbon nanotubes and multi-walled carbon nanotubes.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the conductive ink composition may contain 1 to 10 parts by weight of the nanostructure based on 100 parts by weight of the metal nanoparticles.

The present invention includes a conductive metal thin film produced by the above-described manufacturing method.

According to an embodiment of the present invention, there is provided a metal wiring comprising: a metal film formed of a conductor including metal nanoparticles on a substrate and connected to each other to form a continuous body; And an organic binder mixed with the metal nanoparticles and binding the metal film to the substrate.

The metal wiring according to an embodiment of the present invention is manufactured by photo-sintering of an ink containing a metal nanoparticle and a polymeric binder capped with a capping layer containing a metal acid and a polymeric binder, Lt; / RTI >

The metal wiring according to an embodiment of the present invention may contain 0.05 to 0.1 parts by weight of an organic binder based on 100 parts by weight of the metal nanoparticles.

In the metal wiring according to an embodiment of the present invention, the conductor may further include one or more selected nanostructures in the conductive nanowire, the conductive nanotube, and the conductive nanorod.

The metal wiring according to an embodiment of the present invention may include 1 to 10 parts by weight of the nanostructure based on 100 parts by weight of the metal nanoparticles.

In the metal interconnection according to an exemplary embodiment of the present invention, the nanostructure may include a single-walled carbon nanotube, a double walled carbon nanotube, a thin multi-walled carbon nanotube, One or more carbon nanotubes may be selected from multi-walled carbon nanotubes.

In the manufacturing method according to an embodiment of the present invention, metal nanoparticles whose surface oxide film is controlled are sintered, and light is irradiated to the metal thin film at a strength that the polymer binder does not carbonize, There is an advantage that a conductive metal thin film having an extremely excellent electrical conductivity comparable to that of the substrate can be manufactured with excellent bonding strength to the substrate. Further, since the method has excellent thermal stability, it is possible to prevent the substrate from being damaged in the metal thin film forming step even if the substrate has a very low upper limit of the process temperature of 100 ° C or less, There is an advantage that a thin film can be formed.

FIG. 1 is a view showing a reaction device which can be used in the production of metal nanoparticles,
2 is an optical photograph showing the adhesive force test result of the sample prepared in Example 1,
Fig. 3 is an optical photograph showing a full-bend test process of the sample prepared in Example 1 and a light emission after the bending test,
4 is an optical photograph of a sample prepared using the paper as a substrate in Example 2. Fig.

The manufacturing method of the present invention will be described in detail with reference to the accompanying drawings. The following drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the following drawings, but may be embodied in other forms, and the following drawings may be exaggerated in order to clarify the spirit of the present invention. Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

As a result of intensive researches on a method of manufacturing a metal thin film having excellent commercial viability and being suitable for a flexible part, the present applicant has found that when photo-sintering an ink containing metal nanoparticles with controlled oxide film, A metal thin film having an electrical conductivity comparable to that of the metal thin film is produced.

Further, as a result of intensifying the photo-sintering behavior of the ink containing the metal nanoparticles with the oxide film controlled, it was surprisingly found that by using photo-sintering the ink containing the metal nanoparticles whose oxide film was controlled, The present inventors have found that a conductive metal thin film having an adhesion with an extremely excellent substrate which can not be obtained at the time of defects can be produced.

In detail, a method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention comprises the steps of: a) forming a conductive metal thin film containing metal nanoparticles capped with a capping layer containing an organic acid, a non-aqueous organic binder, Preparing an ink composition; b) applying a conductive ink composition to an insulating substrate to form a coating film; And c) irradiating the coating film with light so as to satisfy the following relational expression 1 to produce a conductive metal thin film.

(Relational expression 1)

I _LS ? I _c

In the relational expression 1, I _LS is the intensity of the light irradiated to the coating film, and I _c is the maximum intensity of the intensity of light in which the non-aqueous organic binder remains in the conductive metal thin film.

 Is a characteristic and unique condition that can only be present when the metal core is optically sintered with an ink containing metal nanoparticles capped with a capping layer comprising an organic acid, i.e., an ink containing metal nanoparticles prevented from surface oxide formation by the capping layer.

In particular, the Applicant has conducted long-term studies on various methods of making thin films of ink containing capped metal nanoparticles containing an organic acid as a capping layer. As a result, surprisingly, it has been found that metal nanoparticles It has been found that a metal thin film can be produced in which sintering is performed even at an extremely low light intensity and the binding force by the non-aqueous binder is maintained even after sintering. In detail, it has been found that the non-aqueous organic binder contained in the ink is not carbonized, and the metal thin film having electric conductivity which remains in the thin film while keeping the physical properties of the binder itself is maintained in bulk is obtained.

Such a light sintering condition (the condition of the relational expression 1) is not known in the field of metal wiring manufacturing method using conventional light sintering, and, under unexplored conditions, a metal nanoparticle containing a metal nanoparticle capped with a capping layer containing an organic acid It is a condition that can only exist when photo-sintering the ink.

That is, the manufacturing method according to the present invention may have a characteristic configuration in which the intensity of light sintered so as to have electric conductivity comparable to that of the bulk is lower than the intensity of light that carbonizes the polymeric binder.

The light sintering condition of the relational expression 1 is very surprising to those skilled in the field of optical sintering using metal nanoparticles. In general, sintering (densification) of metal nanoparticles during light sintering is known to be caused by the instantaneous melting of the surface area of metal nanoparticles due to the high energy applied by the light. In order to sinter (densify) these metal nanoparticles , And light having an intensity of substantially 10 J / cm ² or more is irradiated. However, polymer binders that bind metal nanoparticles to each other at a high temperature (instantaneous high temperature) condition such that at least the surface area of the metal nanoparticles is instantaneously melted, lose their properties and become carbonized. Substantially, upon irradiation with light having an intensity of 10 J / cm ² or more, the polymeric binder loses its inherent physical properties and becomes fully carbonized. However, when the densification mechanism of the surface melting of the metal nanoparticles is taken into consideration, the metal nanoparticles controlled in the oxide film, although the polymer binder is not carbonized and remains in the state of retaining the original properties of the polymer binder, The sintering (densification) of the metal nanoparticles can be performed so as to have electrical conductivity comparable to that of the metal nanoparticles.

As described above, in the manufacturing method according to an embodiment of the present invention, by irradiating light according to the relational expression (1), a conductive metal thin film having the electrical conductivity equivalent to that of the bulk and the polymer binder remaining can be manufactured.

Since the manufacturing method according to an embodiment of the present invention is excellent in thermal stability so that the polymer binder mixed with the metal nanoparticles can remain, even a substrate having an extremely high process temperature of 100 ° C or less can be used without damaging the substrate It is possible to manufacture a conductive metal thin film having an excellent electrical conductivity comparable to that of a bulk, and the bonding strength between the metal thin film and the substrate is extremely excellent due to the residual polymer binder, which makes it possible to manufacture a conductive metal thin film suitable for flexible parts. In addition, by using the light sintering process, it is possible to manufacture a large area in a very short time in the atmosphere, which is advantageous in optical resolution, and it is possible to realize a roll-to-roll process, have.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, in step c), light may be irradiated so as to satisfy the following relational expression 1-1.

(Relational expression 1-1)

I _LS & le; 2.6 (J / cm < ² &

In the relation 1-1, the definition of I _LS is the same as the relation 1.

Specifically, when the intensity of the irradiated light exceeds 2.6 J / cm ² , the polymeric binder contained in the ink is carbonized without remaining in the metal thin film, so that the binding effect between the metal thin film and the substrate by the remaining polymeric binder can be obtained I will not.

Specifically, the manufacturing method according to an embodiment of the present invention is to be prepared a conductive metal thin film having a low resistivity of less than several hundred μΩcm, of 2.6 J / cm ² or less light is irradiated a metal thin film made of a polymeric binder residue .

In the manufacturing method according to the embodiment of the present invention, the light sintering step may be performed by continuously irradiating light of a wavelength band of 200 to 800 nm satisfying the above-described Relation 1, specifically Relation 1-1. Light in a wavelength band of 200 to 800 nm is a wavelength band including light in a visible light band. Such light of 200 to 800 nm is irradiated, thereby causing light sintering of metal particles and minimizing thermal damage to the substrate.

More specifically, the light sintering step is carried out by continuously irradiating the light of the wavelength band of 370 to 800 nm, more specifically, the light of the wavelength band of 400 to 800 nm, satisfying the above-mentioned relational expression 1, specifically the relation 1-1. . The irradiation of the light of the wavelength band of 370 to 800 nm, specifically the light of the wavelength band of 400 to 800 nm, means that light is sintered by visible light, not ultraviolet rays having strong energy.

Light sintering by visible light is a constitution possible by capping with a capping layer containing an organic acid to prevent the formation of a surface oxide film and photo-sintering metal nanoparticles whose surface maintains properties of metals other than oxides. As the light sintering is performed by visible light irradiation, the ultraviolet light irradiation substrate can be remarkably free from thermal damage.

The manufacturing method according to the embodiment of the present invention can continuously irradiate light of intensity satisfying the above-mentioned relational expression 1, specifically Relation 1-1, for 1 to 2 msec. That is, according to an embodiment of the present invention, light can be irradiated for an extremely short time of 1 to 2 msec to produce a metal thin film having a low specific resistance and an extremely excellent adhesion to a substrate. In order to prevent damages to the substrate and sintering at a minimum temperature as light of high energy is irradiated for sintering the metal nanoparticles during the light sintering of the ink containing the conventional metal nanoparticles, Light is irradiated in a pulse form.

However, according to the embodiment of the present invention, it is not necessary to design the pulse width, the pulse gap, the pulse number, etc., which should be individually specified for each substrate by the thickness of the metal thin film to be manufactured, Stable light sintering can be achieved by continuously irradiating light (irradiating continuous light).

The time of light irradiation can affect the substantial temperature of the thin film (the film to which the light is irradiated) and the substantial temperature of the substrate during the light sintering process due to the accumulation of heat generated by the light. The irradiation time of the light can be appropriately changed in consideration of the material of the substrate and the like. However, the light satisfying the relational expression 1, specifically the relational expression 1-1, preferably the relational expression 1 described above, specifically the relational expression 1-1 , Light in a wavelength band of 200 to 800 nm, preferably light in a wavelength band of 370 to 800 nm, more preferably light in a wavelength band of 400 to 800 nm, is continuously irradiated in a time of less than 1 msec, heterogeneous light sintering There is a danger that it is difficult to manufacture a large-area metal thin film, and if it is continuously irradiated for a time exceeding 2 msec, there is a risk of damage to the substrate, such as a polyethylene terephthalate substrate, which has poor heat resistance characteristics due to accumulated heat.

It is needless to say that, in the photo-sintering process, the coating film may be dried after the ink is coated on the substrate in a designed pattern so as to form a coating film, and the drying may be performed at room temperature. The substrate on which the coating film is formed can be irradiated with light. Namely, in the entire region of the substrate on which the coating film is formed, light of a wavelength band of 200 to 800 nm, preferably light of a wavelength band of 370 to 800 nm, more preferably 400 to 800 nm, satisfying the above-mentioned relational expression 1, Light of 800 nm wavelength band can be irradiated for preferably 1 to 2 msec.

As described above, the manufacturing method according to an embodiment of the present invention is a method of manufacturing a conductive ink composition containing metal nanoparticles capped with a capping layer containing organic acid, satisfying the condition of the relational expression 1, specifically, the condition of the relational expression 1-1 So that a conductive metal thin film having excellent electrical conductivity and excellent adhesion to a substrate can be produced.

In the manufacturing method according to the embodiment of the present invention, when irradiated with light, light exceeding the intensity at which sintering of the metal nanoparticles occurs can be irradiated. Specifically, when the light intensity to be irradiated is 1.2 J / cm ² or more, light sintering of metal nanoparticles may occur.

The method according to an embodiment of the present invention may further include a step of preparing metal nanoparticles capped with a capping layer containing organic acid (hereinafter referred to as a particle manufacturing step) before the step a).

The particle preparation step may be a batch or continuous process. The step of preparing the capped metal nanoparticles with a capping layer comprising an organic acid in a batch manner can be carried out by referring to Korean Patent Publication No. 2013-0111180 filed by the present applicant, 0.0 > 0111180. ≪ / RTI >

Specifically, in the case of using batch preparation, the particle preparation step comprises heating a precursor solution comprising a metal precursor, an organic acid, an organic amine and a reducing agent to form a metal nanoparticle capped with a capping layer, The method comprising the steps of: At this time, the heating stirring can be carried out in an inert atmosphere.

The metal of the metal precursor may be one or more selected from the group consisting of copper, nickel, cobalt, aluminum and alloys thereof. The metal precursor may be at least one selected from the group consisting of nitrates, sulfates, acetates, phosphates, silicates and hydrochlorides of metals selected from the group consisting of copper, nickel, cobalt, aluminum, tin and alloys thereof.

The organic acid has at least one form of straight chain, branched or cyclic carbon atoms having 6 to 30 carbon atoms, and may be one 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, In the precursor solution, the molar ratio of the metal precursor and the organic acid may be 1 (metal precursor): 0.2 to 4 (acid).

The organic 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 in the precursor solution may be 0.2 mol or more, preferably 1 to 50 mol, more preferably 5 to 50 mol, per mol of the metal precursor. However, since the organic amine can act as a non-aqueous solvent at the upper limit, It does not.

The reducing agent may be one or two or more selected from hydrazine-based reducing agents including 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. In the precursor solution, the reducing agent may include a reducing agent / metal precursor molar ratio of 1 to 100.

In the batch method, the synthesis of the metal nanoparticles is not limited, but may be performed at 100 to 350 ° C, more preferably at 140 to 300 ° C, and more preferably at 150 to 250 ° C in consideration of the reduction efficiency, Lt; / RTI > It goes without saying that the metal nanoparticles can be separated and recovered by a conventional method used for nanoparticle recovery such as centrifugation.

Independently, metal nanoparticles capped with organic acids can be continuously produced in a continuous process based on a Taylor-Quatt reactor (laminar flow shear flow reactor). Such continuous production can mass-produce metal nanoparticles of good quality in a short period of time, and has an advantage of easily controlling the particle size distribution of the produced metal nanoparticles.

In the case of continuous production, the particle preparation step includes a first solution containing organic acid, organic amine and metal precursor and a reducing agent in a reaction space, which is a space between a hollow cylindrical jacket and a rotating cylinder which is concentric with the jacket, And continuously injecting a second solution containing the first solution.

FIG. 1 is a view showing an example of a laminar flow shear flow reaction apparatus which can be used in a manufacturing method according to an embodiment of the present invention. As shown in Fig. 1, the laminar flow front end reaction apparatus is formed in the center of the cylinder and the cylinder, one end of which is connected to the motor to concentrically rotate the stirring rod and the stirring rod for rotating the cylinder, An inlet for injecting the material into the reaction space, which is a space between the jacket and the cylinder, and an outlet for discharging the reacted product. Thus, the cylinder can have a rotation axis coinciding with the longitudinal axis of the jacket.

At this time, as shown in Fig. 1, the inlet may be located at one end or one end of the jacket, and the outlet may be located at the other end or the other end of the jacket. Further, it goes without saying that the laminar flow shear flow reactor may further include a heating unit positioned on the outer side of the jacket to heat the reaction space, and it is a matter of course that the heating unit may be located around the outer side of the jacket.

When the cylinder is rotated in a fixed jacket, the fluid flowing in the reaction space tends to flow out in the direction of the fixed jacket due to the centrifugal force, whereby the fluid becomes unstable, and is regularly rotated along the rotation axis, A quasi-Taylor vortex can be formed, which is a swirl of high-paired arrays.

As Kuett-Taylor vortex only generates vortexes by relative rotation between the inner cylinder and the jacket, the flowability of the vortex can be well defined and little or no fluctuation of the vortex can occur. In addition, each of the vortexes of the rotating high-pair array can form reaction fields independent of each other in the reaction space.

When the metal nanoparticles are prepared by introducing organic acids, organic amines, metal precursors and reducing agents into the micro-reaction fields defined by the vortex and vortex of the high-paired arrays, the metal cores react with the organic acids in a stable and reproducible yield Capped metal nanoparticles can be prepared.

In detail, the laminar flow shear flow continuous reaction technique based on the Taylor-Quet vortex generates a vortex having a well-defined flow only by the rotation of the cylinder, and as each vortex forms an independent fine reaction field, In the course of metal nuclei generated from metal and growing metal nuclei into metal nanoparticles, the organic acid added together with the metal in the precursor state can very stably trap the metal nanoparticles. In addition, capped metal nanoparticles can be prepared with a capping layer comprising an organic acid with a very high yield of 95% or more.

Similarly to the above, the inlet may be formed at one end or one end of the jacket, and a first inlet through which the first solution is injected and a second inlet through which the second solution is injected may be formed. Independently, the first solution and the second solution can be injected through a single inlet by injecting the first solution and the second solution into the inlet and mixing with each other.

That is, the first solution and the second solution are continuously injected into the reaction space through the inlets formed on one or both sides of the jacket, so that the metal nano-particles capped with the capping layer through the outlet formed at the other end of the jacket The reaction products containing the particles are continuously discharged, so that the metal nanoparticles can be continuously produced. At this time, the first solution and the second solution can be simultaneously injected through a single inlet in view of strictly and reproducibly controlling the particle size distribution of the produced metal nanoparticles.

In the manufacturing method according to the embodiment of the present invention, the jacket and the cylinder can satisfy the following relational expression (2).

(Relational expression 2)

0.1? D / r _i ? 0.4

In Equation 2, D is the spacing between the jacket and the cylinder, and r _i is the radius of the cylinder.

(D / ri) of the distance between the jacket and the cylinder (D = r _o (inner radius of the jacket) -r _i ) and the radius of the cylinder (r _i ) is preferably 0.1 to 0.4.

The gap between the jacket and the cylinder can influence the size and distribution of the synthesized particles as it determines the size of the vortex cell, which is the vortex of the high-paired array being formed. If the value of D / ri is less than 0.1, the probability that the particles will fill the gap will increase, which decreases the fairness. If the value of D / ri is larger than 0.4, the vortex cell formed becomes larger in size, It is difficult to do.

Specifically, it is preferable that the distance between the jacket and the cylinder is 1 mm to 2.5 mm, and the width of the reaction space is extremely small. When the width of the reaction space is as small as 1 mm to 2.5 mm, it is advantageous to manufacture a bimodal distribution metal nanoparticle having a better photo-sintering property.

The retention time at which the reactive fluid containing the injected first and second solutions stays in the reaction space can be controlled by the rotational speed of the cylinder and the input amount of the reactive fluid.

The rotational speed of the cylinder is preferably 400 rpm or more in terms of stable Taylor-Kuett vortex formation. In addition, sufficient reactants are present in each vortex cell to produce homogeneous nanoparticles. Accordingly, the rotation speed of the cylinder is preferably 1000 rpm or less.

In terms of producing bimodal distribution metal nanoparticles having better optical sintering characteristics, the rotation speed of the cylinder is preferably 600 to 800 rpm. This rotational speed is due to the reactivity of the reactants present in the vortex cell, resulting in continuous nucleation and growth of the metal, as well as the consumption of fine particles among the grown particles and the growth of coarse particles, The reaction force and the driving force provided by the fine particles on the particle size distribution of the particles remaining in the reaction field at that point of time), inhibiting the growth of other particles, or re-melting the fine nuclei and increasing the fraction of the finer particles Metal nanoparticles can be produced.

In the production method according to an embodiment of the present invention, the reaction temperature is not particularly limited, but it can be reacted in the range of 100 to 350 ° C, preferably 120 to 200 ° C, more preferably 130 to 150 ° C Metal nano-particles having a purity of 95% or more can be produced even at a yield while having resistivity characteristics.

Preferably, the reaction temperature is in the range of 130 to 150 占 폚 so that the bimodal distribution metal nanoparticles having better light sintering characteristics can be produced. The overall nucleation and growth driving power in the vortex cell can affect the rate at which it is consumed and the degree of nucleation. Due to the low temperature of 130-150 DEG C, the particle size difference between the relatively small particles and the relatively large particles can be increased, resulting in an increase in the proportion of relatively small particles and a decrease in the average size of relatively small particles .

In this case, the reaction temperature affects the rate at which the whole driving force of the vortex cell is consumed and the degree of nucleation. As the rotational speed of the cylinder controls the overall driving force of the vortex cell, the reaction temperature and the rotational speed are independently presented Rather than being regulated in the range, it is better to be coordinated. As a specific example, it is preferable that the rotation speed and the reaction temperature are proportional to each other. For example, when the rotation speed increases from 600 rpm to 800 rpm, the reaction temperature is preferably increased from 130 캜 to 150 캜.

The length of the jacket is advantageous for mass production, and it is long enough to stably form a plurality of vortex cells, but it is sufficient that the produced metal nanoparticles do not remain in the jacket for an excessively long time. In a specific, non-limiting example, the length of the jacket (longitudinal axis length of the reaction space) may be 30 to 50D (D = separation distance between the jacket and the cylinder).

In continuous production, the residence time in which the reaction fluid containing the first solution injected through the inlet and the second solution remains in the reaction space is preferably 1 to 4 minutes. Such a residence time can be controlled through the rate of injection of the reactive fluid injected through the inlet at the aforementioned rotational speed and the jacket length described above. That is, the injection rate of the first solution and the second solution may be such that the residence time of the reaction fluid is 1 to 4 minutes.

In the continuous production, a spiral protrusion may be formed on the inner circumferential surface of the jacket along the longitudinal direction in the rotating direction of the cylinder. When such spiral protrusions are formed, the mixing efficiency of the reactants is further increased, and the reduction reaction is completed in a shorter time, so that the metal nanoparticles can be rapidly produced.

In continuous preparation, the first solution may comprise a metal precursor, an organic acid and an organic amine, and the second solution may comprise a reducing agent. The metal precursor, organic acid, organic amine and reducing agent materials are similar or identical to those described above in the batchwise process.

The composition ratio of the first solution is not particularly limited. However, considering the capping efficiency, the acid may be 0.2 to 4 moles, preferably 1 to 4 moles, and the organic amine may be 0.2 or more, preferably 0.2 to 50 moles per mole of the metal precursor. , More preferably from 5 to 20 moles. In the case of organic amines, the upper limit is not particularly limited as it acts as a non-aqueous solvent.

The first solution and the second solution may be injected so that the molar ratio of the reducing agent / metal precursor to the metal precursor is 1 to 100 in the first solution. If the molar ratio (reductant / metal precursor) is less than 1, metal ions of the metal precursor are not completely reduced. If the molar ratio is less than 1, the metal precursor is excessively over 100, which does not affect the reduction rate.

As described above, the metal nanoparticles of step a) may be produced continuously or batchwise, but the present invention is not limited by the method of producing the metal nanoparticles. However, metal nanoparticles can be produced by a continuous method in view of more easily producing metal nanoparticles and controlling the particle size distribution of the metal nanoparticles.

In the manufacturing method according to an embodiment of the present invention, the metal nanoparticles of step a) may be one in which the metal core is capped with a capping layer containing an organic acid. The organic acid can preferentially chemisorb the metal core to form a dense organic acid film, so that the capping layer can be made of an organic acid. That is, the capping layer may be a film of organic acid chemically adsorbed on the metal core. However, it goes without saying that a small amount of amine may be included in the capping layer in the manufacturing process using an organic acid and an organic amine together. As the metal core is capped with a capping layer comprising an organic acid, the formation of a surface oxide film of the metal core can be prevented, and in the case of coarse particles of substantially 100 to several hundred nanometer order, there can be no surface oxide film.

The organic acid of the capping layer has at least one form of straight chain, branched or cyclic having 6 to 30 carbon atoms, and may be one or more selected from saturated or unsaturated organic acids. More specifically, the organic acid may be selected from the group consisting of oleic acid, lysine oleic acid, stearic acid, hyrodoxystearic acid, linoleic acid, aminodecanoic acid, hydroxydecanoic acid, lauric acid, decenoic acid, undecenoic acid, But is not limited to, one or more selected from the group consisting of sildenaconic acid, hydroxamic acid, hydroxymic acid, hydroxymic acid, hydroxydecanoic acid, palmitoleic acid and myristicoic acid.

The thickness of the capping layer capping the metal core may be between 1 and 2 nm. When the capping layer is too thin, the effect of preventing the formation of the oxide film can be reduced. Also, when the thickness of the capping layer is excessively large, excessive energy and time for removing the organic capping layer Can be consumed.

The metal (metal core) of the capsule-shaped metal nanoparticles capped with a capping layer containing an organic acid and inhibited from forming an oxide film may be a metal conventionally used for producing a metal thin film. As a specific example, the metal may be one or more selected from the group consisting of copper, nickel, cobalt, aluminum, tin and alloys thereof, and the like.

In the manufacturing method according to the embodiment of the present invention, in order to have better light sintering characteristics, the metal nanoparticles of step a) have a size distribution of at least bimodal and satisfy the following relational expression 1 .

(Relational expression 3)

0.4? A ₁ / A _t ?

In the equation 3, A ₁ is the area of the first peak having in the size distribution of the metal nanoparticles (size distribution of the number and size of the two-axis), relative to the center of the size of the peak, the smallest center size, A _t Is the total area of the areas of all the peaks forming the size distribution. That is, the relation 1 is the ratio of the number of particles forming the first peak divided by the number of total particles.

In one embodiment, the size distribution of the metal nanoparticles may be measured using Dynamic Light Scattering (DLS), and more specifically, at a temperature of 25 ° C and a sample of 0.01 to 0.1% The target nanoparticle to be analyzed). The size distribution of the metal nanoparticles may be a size distribution as shown by the diameter of the particles and the number of particles having that diameter. The size distribution of at least bimodal may mean that at least two peaks are present in the size distribution of the metal nanoparticles. At this time, the particles (particle diameter) corresponding to the center of the peak are the center sizes, the particles belonging to the first peak having the smallest center size are the first particles, and the particles belonging to the second peak having the largest center size 2 particles.

When the proportion of the relatively small first particles among the relatively small first particles and relatively large second particles of the metal nanoparticles of step a) is remarkably high as shown in the relational expression 3, A metal thin film having remarkably excellent electrical conductivity can be produced even at a very low light intensity.

Further, in order to provide a high sintering driving force, the metal nanoparticles in which the metal core of step a) is capped with a capping layer containing an organic acid may further satisfy the following relational expression (4) and (5).

(Relational expression 4)

30 nm? D ₁ ? 100 nm

In the relation 4, D ₁ is the center size of the first peak, i.e., the average size of the first particles.

(Relational expression 5)

3? D ₂ / D ₁ ? 5

In the relation 5, D ₁ is the center size of the first peak having the smallest center size, and D ₂ is the center size of the peak in the size distribution of the metal nanoparticles, Is the center size of the second peak having the largest center size. That is, in the relationship 5, D ₁ is the average size of the first particles and D ₂ is the average size of the second particles.

By satisfying the condition of the relational expression (3) and satisfying the relational expression (4) and the relational expression (5), extremely active mass transfer occurs from the first grains to the second grains, and excellent optical sintering ability can be obtained.

More preferably, when the first particles are present in a large amount to satisfy the relational expression (3), even if the particle size is very fine and the surface oxidation is slightly small despite the capping layer as in the relational expression (4) Is still capable of maintaining excellent light sintering ability.

The metal nanoparticles satisfying the above-described relational expression 2, preferably the relational expressions 2, 3 and 4, can be produced by more preferable continuous production conditions, but the present invention is not limited thereto. The metal nanoparticles prepared in a batch or continuous manner under various conditions are mixed with each other to prepare the metal nano-particles satisfying the relation 2, preferably the metal nano-particles satisfying the relational expressions 2, 3 and 4 It goes without saying that particles can be obtained.

In the step a), a conductive ink composition containing capped metal nanoparticles, a non-aqueous organic binder, and a non-aqueous solvent may be prepared by capping a capping layer containing the organic acid.

The non-aqueous solvent is not particularly limited, but it may preferably be an alkane, amine, toluene, xylene, chloroform, dichloromethane, tetradecane, octadecene, chlorobenzene, dichlorobenzene, chlorobenzoic acid, and dipropylene Glycol propyl ether, and the like.

The non-aqueous organic binder is not particularly limited, but a non-aqueous organic binder material that is commonly used to improve the physical binding force of a coating film can be used in the production of a conductive ink containing metal particles. Specific, non-limiting examples of non-aqueous organic binder materials include polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), self-crosslinking acrylic resin emulsion, hydroxyethylcellulose, ethylhydroxyethylcellulose, carboxy (SBR), a copolymer of C1-C10 alkyl (meth) acrylate and an unsaturated carboxylic acid, gelatin, tinson (Thixoton), and the like. ), Starch, polystyrene, polyurethane, a resin containing a carboxyl group, a phenolic resin, a mixture of ethylcellulose and a phenolic resin, an ester polymer, a methacrylate polymer, a self-crosslinking (meth) acrylic acid copolymer, Ethylenically unsaturated group-containing copolymers, ethylcellulose series, acrylate series, epoxy resin series and mixtures thereof One or two or more can be selected.

As a more specific example, the non-aqueous organic binder may be a non-aqueous polymeric material having an amine value of 5 to 150 mgKOH / g. Such a non-aqueous polymeric material can simultaneously perform the role of a binder and a dispersant. In particular, the non-aqueous organic binder may be a copolymer of an unsaturated carboxylic acid or a graft polymer thereof, and may be a copolymer of an unsaturated carboxylic acid having an amine value of 5 to 150 mgKOH / g or a graft polymer thereof. Such a non-aqueous organic binder can perform the function of a binder and a dispersant at the same time, but does not interfere with the binding between the metal particles during the photo-sintering, so that a metal thin film having a more dense and more excellent conductivity can be produced. Copolymers of unsaturated carboxylic acids or graft polymers thereof having an amine value of from 5 to 150 mg KOH / g may be copolymerized with a copolymer of a C1-C10 alkyl (meth) acrylate and an unsaturated carboxylic acid, a polyisothiazole with an unsaturated carboxylic acid , Copolymers of polyacrylamide and unsaturated carboxylic acid, copolymers of polyethylene oxide and unsaturated carboxylic acid, copolymers of polyethylene glycol and unsaturated carboxylic acid, or mixtures thereof. When the copolymer is an unsaturated carboxylic acid having an amine value of 5 to 150 mgKOH / g or a graft polymer thereof, its molecular weight (weight average molecular weight) may be 1000 to 50000 g / mol.

As a non-aqueous organic binder, a commercial product containing the above non-aqueous organic binder material may be used. Specific examples thereof include BYK130, BYK140, BYK160, BYK161, BYK162, BYK163, BYK164, BYK165, BYK167, BYK169, BYK170 , BYK171, BYK174 EFKA 4610, EFKA 4644, EFKA 4654, EFKA 4665, EFKA 4620, EFKA 4666, or EFKA 4642, but the present invention is not limited thereto.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the conductive ink composition may include 0.05 to 5 parts by weight of a non-aqueous organic binder and 20 to 800 parts by weight of a non-aqueous solvent ≪ / RTI >

According to one embodiment of the present invention, the non-aqueous organic binder may remain in the conductive metal thin film without impairing its inherent physical properties during light sintering. Accordingly, if the content of the non-aqueous organic binder in the conductive ink composition is too high, densification between the metal nanoparticles may be inhibited by the polymeric binder that binds the metal nanoparticles to the substrate. The non-aqueous organic binder in an amount of 0.05 to 5 parts by weight based on the particles has a physical strength that stably maintains the shape when the applied ink composition is dried without hindering the densification between the metal nanoparticles and forms a coating film having excellent adhesion with the substrate And at the same time, the binding force between the substrate metal thin films can be remarkably improved by the polymer binder remaining in the metal thin film after photo-sintering.

May be somewhat different depending on the application method of the conductive ink composition, but the conductive ink composition may contain a non-aqueous solvent of 20 to 800 parts by weight, so that the conductive ink composition may have a fluidity suitable for coating or printing.

In the method of manufacturing a photo-sintered conductive metal thin film according to an exemplary embodiment of the present invention, the conductive ink composition may further include one or more selected nanostructures in the conductive nanowire, the conductive nanotube, and the conductive nanorod.

The above-described nanostructure plays a role of improving the electrical conductivity of the conductive metal thin film produced under the light sintering condition satisfying the above-mentioned relational expression 1, and in the light sintering satisfying the above-mentioned relational expression 1, The heat transfer medium can be used as a heat transfer medium.

In detail, the conductive nanowires, conductive nanotubes and / or conductive nanorods have a relatively high aspect ratio relative to the particles, thus improving the contact between the conductive materials. That is, when the metal nanoparticles and the nanostructure are uniformly dispersed in the metal thin film (or the coating film of the conductive ink composition), a network is formed between the nanostructures, and contact between the nanostructure and the plurality of metal nanoparticles is formed, The electrical conductivity of the metal thin film can be improved, and the homogeneity of electrical characteristics can be improved even in a metal thin film having a large area.

In addition, as described above, the coating film of the conductive ink composition is photo-sintered at an extremely small energy satisfying the relationship (1). As the thickness of the metal thin film to be manufactured (the thickness of the coating film) becomes thicker depending on the light sintering conditions, the sintering characteristics between the surface region, which is the region where the light is incident, and the lower region, which is the region adjacent to the substrate, may be different. That is, there is a risk that the sintering of the metal nanoparticles may not be sufficient in the lower region of the coating film adjacent to the substrate.

The nanostructure contained in the conductive ink composition can act as a heat transfer medium that effectively transfers phonons generated by the light incident on the surface region to the lower region as the nanostructure has a large aspect ratio. By the faster and more uniform heat transfer by the nanostructure, even a thick coating film can be sintered homogeneously in the thickness direction, and a metal thin film having highly uniform electrical characteristics can be manufactured even if it is a large-area coating film .

The nanostructure acting as a heat transfer medium is more important than the case of using metal nanoparticles capped with a capping layer containing an organic acid as in an embodiment of the present invention. Specifically, by using the metal nanoparticles in which formation of the surface oxide film is prevented, sintering can be performed under the light sintering condition in which the energy is remarkably low. However, the interface between the metal nanoparticles and the void space between the metal nanoparticles act as one of the main factors causing phonon scattering. As the size of the metal nanoparticles becomes smaller, phonon scattering due to these factors becomes more difficult Can be deepened. Accordingly, when the conductive ink composition does not contain a nanostructure, the thickness of the metal thin film to be produced may be restricted. Specifically, the conductive ink composition containing no nanostructure is more suitable for producing a metal thin film having a thickness of 10 占 퐉 or less and more stably 3 占 퐉 or less.

However, by containing the nanostructure in the conductive ink composition, a thin thick film of metal can be produced by transferring and redistributing the phonons generated by the irradiated light quickly and uniformly to the entire area of the coating film including the lower portion of the coating film , A thick-film metal film having a large area having uniform electrical characteristics can be produced.

As a practical example, when the metal thin film to be produced is a thick film having a thickness of 10 탆 or more, the conductive ink composition may contain a nanostructure. That is, in the case where the metal thin film to be produced is 10 μm or less, the conductive ink composition may contain the nanostructure in terms of improving the electrical conductivity of the metal thin film to be produced. In the case of producing a thick metal thin film having a thickness of 10 μm or more, The conductive ink composition preferably contains the nanostructure so that the thin film is photo-sintered substantially homogeneously.

In addition, as described above, light sintering of the metal nanoparticles occurs at a light intensity of 1.2 J / cm ² or more, but when the thickness of the metal thin film to be manufactured is several micro to tens of micro-microns, It is preferable that light having a light intensity of 2.3 J / cm ² or more is irradiated from the viewpoint of producing the thin film reproducibly.

As described above, more uniform sintering can be performed in the plane direction and the thickness direction by the nanostructure, and since the electrical conductivity can be improved by increasing the contact point between the nanostructure network and the nanostructure and the metal nanoparticles, It is a matter of course that the conductive ink composition may contain a nanostructure even if the metal thin film to be fabricated is a thin film having a thickness of several hundred nanometers.

In the manufacturing method according to an embodiment of the present invention, the nanostructure may be a material having a thermal conductivity higher than that of the metal material of the metal nanoparticles. As described above, even if the nanostructure has the same thermal conductivity as that of the metal nanoparticles, the scattering of the phonons is prevented through the nanostructure and the nanostructure network, and heat transfer is possible, and thus the nanostructure can play the role of the heat transfer medium .

However, even in the case of the thick film metal thin film having a thickness of 30 탆 under the light irradiation condition of the relational expression 1, the homogeneous light sintering is carried out, and in order to have excellent and uniform electrical conductivity, the thermal conductivity of the nanostructure is 50 W / mk Specifically, 100 W / mK or more, more specifically 300 to 6000 W / mK.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the nanostructure may include single-walled carbon nanotubes, double walled carbon nanotubes, thin multi-walled ) Carbon nanotubes and multi-walled carbon nanotubes.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the aspect ratio of the nanostructure may be 10 to 10000. By this aspect ratio, even when a metal thin film having a thickness of 3 탆 or more, specifically 10 탆 or more is intended to be produced, the phonon generated by the irradiated light can be transferred and redistributed to the entire area of the coating film including the lower portion of the coating film.

In the method of manufacturing a photo-sintered conductive metal thin film according to an embodiment of the present invention, the conductive ink composition may contain 1 to 10 parts by weight of the nanostructure based on 100 parts by weight of the metal nanoparticles. When the conductive ink composition contains less than 1 part by weight of the nanostructure, there is a risk that the three-dimensional network in which the nanostructures are continuously contacted can not be formed. If the conductive ink composition contains more than 10 parts by weight of the nanostructure, the electrical conductivity may be lowered by interfering with the homogeneous spatial distribution of the metal nanoparticles.

In detail, the conductive ink composition may contain 1 to 10 parts by weight of a nanostructure, 0.05 to 5 parts by weight of a non-aqueous organic binder, and 20 to 800 parts by weight of a non-aqueous solvent, based on 100 parts by weight of the metal nanoparticles.

The application of the conductive ink composition may be carried out by the method of coating or printing in the present invention. As a specific example, the coating may be performed using dip coating, spin coating or casting, and the printing may be carried out by any suitable technique, such as screen printing, inkjet printing, electrostatic hydraulics printing, microcontact printing, imprinting, gravure printing, reverse offset printing, Can be performed using offset printing. The application of the conductive ink composition can be applied to have an appropriate pattern according to the design of the product to be manufactured. Alternatively, after the conductive ink composition is applied to the insulating substrate, Of course, can be carried out.

The insulating substrate to which the conductive ink composition is applied can be any substrate as long as it has an insulating property according to the features of the present invention described above.

For example, the polyethylene terephthalate substrate has good flexibility, high light transmittance, excellent chemical stability to an organic solvent, low water absorption, low cost process, and high commercial value because it can be formed by melt-extrusion . However, since the maximum process temperature of the polyethylene terephthalate substrate is in the range of 80 to 150 占 폚, there is a great difficulty in forming the metal wiring on the substantially polyethylene terephthalate substrate. However, the manufacturing method according to one embodiment of the present invention can produce a conductive metal thin film having a very excellent electric conductivity even on a polyethylene terephthalate substrate requiring an extremely low process temperature, as shown in the following embodiments.

As described above, according to the features of the present invention, the substrate can be any substrate having an insulating property, and a specific and non-limiting example is polyethylene terephthalate, polyethylene naphthalate, polyetherketone, polycarbonate, Organic substrates such as polyarylate, polyethersulfone and polyimide, inorganic substrates such as glass, and paper.

The present invention includes a metal thin film produced by the above-described manufacturing method. In this case, it is needless to mention that the ink may be coated in a predetermined pattern at a predetermined position on the substrate and may be manufactured as a metal thin film by photo-sintering, Of course).

The present invention relates to a metal film on which a metal nanoparticle-based conductor is connected to form a continuum, And an organic binder mixed with the metal nanoparticles and binding the metal film and the substrate.

In detail, the metal film as a continuous film is formed such that one metal nanoparticle is in contact with at least one or more metal nanoparticles of the metal nanoparticles adjacent to the one metal nanoparticle as a grain boundary, and the metal nanoparticles are continuously connected State. ≪ / RTI >

As described in the manufacturing method, the conductor may further include one or more selected nanostructures in the conductive nanowire, the conductive nanotube, and the conductive nanorod.

When the conductor further comprises a nanostructure, the metal film as a continuum is bonded to at least one or more metal nanoparticles of the metal nanoparticles adjacent to the one conductor based on the one conductor (one metal nanoparticle or one conductive nanostructure) It may refer to a state in which conductors are continuously connected to each other in contact with another conductive nanostructure. At this time, the metal film as a continuum may include a network of conductive nanostructures.

The organic binder may be present in combination with the conductor. That is, the organic binder may exist in a certain layer between the metal film and the substrate, or may exist in the metal film inside and on the surface, rather than being present independently of the metal film in a part of the surface of the metal film, . Thus, the organic binder can bond the metal film to the substrate from the inside of the metal film, and the binding force between the metal film and the substrate can be remarkably improved.

Specifically, the metal wiring is produced by photo-sintering an ink containing metal nanoparticles and a polymeric binder or an ink containing metal nanoparticles, a nanostructure and a polymeric binder, and the organic binder may be a polymeric binder contained in the ink . More specifically, the organic binder may be a polymeric binder mixed with a conductor before photo-sintering to bind the conductor and between the conductor and the substrate and remain in the metal film after photo-sintering.

 At this time, the metal nanoparticles may be metal nanoparticles capped with a capping layer containing an organic acid as described above in the method of manufacturing a metal thin film.

At this time, the thermal conductivity of the nanostructure may be 50 W / mk or more, specifically 100 W / mK or more, and specifically 300 to 6000 W / mK. As a specific example, the nanostructure may be a single-walled carbon nanotube, a double walled carbon nanotube, a thin multi-walled carbon nanotube, or a multi-walled carbon nanotube One or more of which may be selected.

The ink may be a conductive ink composition prepared by previously preparing a conductive ink composition containing a metal nanoparticle-containing conductor, a non-aqueous organic binder, and a non-aqueous solvent in the method of manufacturing a metal thin film, The sintering is carried out in the same manner as in the production method of the metal thin film, which satisfies the above-mentioned relational expression 1, specifically the relation 1-1, and the light of the wavelength band of 200 to 800 nm, preferably the light of the wavelength band of 370 to 800 nm, The light in the wavelength band can be irradiated for 1 to 2 msec. In describing the metal wiring, the same as or similar to the above-mentioned contents in the manufacturing method of the metal thin film, such as the size of the metal nanoparticles, the material, the material of the polymer binder, the material of the nanostructure,

The metal wiring according to an embodiment of the present invention may contain 0.05 to 0.1 part by weight of an organic binder based on 100 parts by weight of metal nanoparticles constituting a metal film. The content of such an organic binder is a content capable of having a strong binding force that does not cause peeling between the metal wiring and the substrate after the full bend test, without compromising the inherent electrical conductivity of the metal film.

The metal wiring according to an embodiment of the present invention may have a thickness of 100 nm to 30 μm and a specific resistance of 20 μΩcm or less.

(Production Example 1)

A first solution prepared by mixing 1.41 mol of octyl amine, 0.20 mol of oleic acid and 0.14 mol of copper (II) acetate and a second solution of 1.96 mol of phenyl hydrazine were prepared . A laminar flow shear flow reactor having a cylinder outer diameter of 19 mm and an inner diameter of the jacket of 23 mm and a reaction space between the cylinder and the jacket of 2 mm and a length of 90 mm was heated to 150 캜 using a heating section surrounding the jacket. The injection rate of the first solution and the second solution was adjusted so that the relative injection rate (volume / time) of the first solution and the second solution was 1.6: 1 and the residence time was 1 minute, 2 minutes and 4 minutes Was injected through the inlet of the reactor. At this time, the temperature of the reaction zone was maintained at 150 ° C through the heating part. The first solution and the second solution prepared by using the syringe pump were continuously injected into the laminar flow shear flow continuous reactor while rotating the cylinder at 800 rpm, Nanoparticles were synthesized. The copper nanoparticles obtained through the outlet of the reactor were washed and recovered by centrifugation.

The copper nanoparticles were analyzed by transmission electron microscopy. As a result, it was found that a capping layer having a thickness of about 1 nm was formed on the copper core of the monocrystal. The C 1s and O 1s peaks were analyzed using X-ray photoelectron spectroscopy , It was confirmed that the capping layer was formed by oleic acid having an alkyl chain (CC) and a carboxylate (-COO ^- ) moiety.

The size distribution of the copper nanoparticles prepared by the dynamic light scattering method was measured. As a result, it was confirmed that the particles having bimodal distribution were produced. When the retention time was 2 minutes, A ₁ / A _t = 0.5 and D 1 = 70nm, and D ₂ / D ₁ = 3 which are nanoparticles is manufactured, and the case of one minute of the retention time, a is _{1 / a t = 0.8, D1} = 50nm , and the nanoparticles D ₂ / D ₁ = 4 production, For a retention time of 4 minutes, nanoparticles with A ₁ / A _t = 0.4, D ₁ = 100 nm and D ₂ / D ₁ = 3 were prepared.

(Production Example 2)

In Production Example 1, copper nanoparticles were prepared in the same manner as in Production Example 1, except that the reaction temperature was set to 130 캜, the cylinder rotation speed was set to 600 rpm, and the residence time was fixed to 2 minutes. A ₁ / A _t = 0.6, D ₁ = 100 nm and D ₂ / D ₁ = 100 nm were obtained by measuring the size distribution of the copper nanoparticles prepared using the dynamic light scattering method. As a result, 3.5 phosphor nanoparticles were produced.

(Example 1)

In Production Example 1, 2 g of copper nanoparticles prepared in a retention time of 2 minutes, 8 g of substance toluene as a non-aqueous solvent and 0.02 g of BYK 130 as a polymer binder were mixed and subjected to ball milling and ultrasonic irradiation to form a uniform dispersion phase A conductive ink composition was prepared.

The resulting conductive ink composition was applied to a polyethylene terephthalate substrate using a drop casting method, and then, using a light source (linear B-type for Xenon PLA-2010 sintering system) having a wavelength band of 370-800 nm, time (msec), strength (J / cm ^2)] is [0.5, 0.36], [0.5, 0.47], [0.5, 0.56], [0.5, 0.80], [1.0, 0.80], [1.0, 1.06], [1.0, 1.24], [1.0, 1.73], [1.5, 1.26], [1.5, 1.63], [1.5, 1.90], [1.5, 2.57], [1.5, 1.67] , 2.53] or [1.5, 3.33], thereby preparing a conductive metal thin film on a polyethylene terephthalate substrate. At this time, the thickness of the metal thin film formed by light irradiation was 300 nm.

The resistivity of the prepared conductive metal thin film was measured using a 4-point probe.

A tape based on the ASTM D3359-97 method was used for the adhesion test between the prepared conductive metal film and the substrate. A bending test was conducted to test the interfacial properties and conductivity deterioration of the prepared conductive metal thin film and the substrate. Specifically, the bending test was conducted under a bending radius of 1-10 mm through a two-point bending test.

The sample used in the adhesion test was a conductive metal thin film (thickness of the thin film = 300 nm) of a rectangular pattern having a length x width of 20 mm x 16 mm on a polyethylene terephthalate substrate having a length x width x thickness 20 mm x 20 mm x 0.1 mm . The sample used in the bending test was a conductive metal thin film (thickness of the thin film = 300 nm) of a rectangular pattern having a length x width of 20 mm x 16 mm on a polyethylene terephthalate substrate having a length x width x thickness 20 mm x 20 mm x 0.1 mm .

As a result of measuring the resistivity of the conductive metal thin film prepared in Example 1, when the light was irradiated at a strength of 1.06 J / cm ² or less, the resistance was very high and the light sintering was almost impossible to be used for metal wiring or electrodes . Specifically, when light was irradiated at an intensity of 1.06 J / cm ² or less, the specific resistance was at least 10 ⁵ Ωcm. At this time, it was confirmed that a metal thin film having a very low resistivity of 6.7 to 17.0 mu OMEGA cm was produced when light was irradiated with a light intensity of 1.24 to 2.57 J / cm < ^{2 &} gt ;.

In addition, when the intensity of the irradiation light was 3.33 J / cm ² or more, it was confirmed that the metal thin film separated from the substrate during the adhesion test and had a very low adhesive force. Figure 2 is when the light is irradiated to the sample Similarly, below 2.57 J / cm ² with an optical photograph of the adhesion test results of the light is irradiated to the sample 2.17J / cm ^2, Fig. 2, adhesive strength test when the metal thin film Was not separated from the substrate.

As a result of observing the metal thin film produced by irradiating light between 1.24 and 2.57 J / cm ² with a scanning electron microscope, it was found that the metal particles were stably contacted with each other at an interface with each other, and the densification was effectively performed even in the state where the polymer binder remained. .

The metal thin film prepared in Example 1 was analyzed by X-ray photoelectron spectroscopy (XPS), and the content of the polymer binder remained in the metal thin film was measured according to the intensity of the irradiated light. As a result, In the case of a simple dried sample, it contained about 0.08% by weight of polymer (1% by weight of the total of the metal and the polymer), and in the case of the metal thin film produced by light irradiation at 1.24 to 2.57 J / cm ² , Almost independently about 0.05% by weight of the polymer was contained. In the case of the metal thin film prepared by irradiating light at 3.33 J / cm ² in the examples, it was confirmed that substantially all of the polymer binder was carbonized. In order to confirm these results again, a coating film was formed on a polyethylene terephthalate substrate in the same manner as in Example 1, and a metal thin film was prepared by irradiating light at 4.00 J / cm ² and analyzed by X-ray photoelectron spectroscopy. As a result of the metal thin film produced by irradiation with light of J / cm ² , it was confirmed that substantially all of the polymer binder was carbonized. Thus, when light sintering is performed under the condition satisfying the relational expression 1-1, a metal thin film having an extremely low specific resistance of 6.7 to 17.0 mu OMEGA cm is produced, and at the same time, a metal thin film having a resistivity of 60 It can be seen that the metal thin film having remained in the metal thin film after the light irradiation and having remarkably improved adhesion with the substrate is produced.

FIG. 3 is a photograph showing a metal thin film produced by light irradiation at 1.90 J / cm ² , showing that the electrical conductivity of the metal thin film is maintained after the full bend test and the bending test. A stable current flows through the bulb. After the full bend test, the resistivity was measured and the resistivity increase rate (resistivity before bend test - resistivity before bend test / resistivity before bend test * 100 (%)) was 60% or less based on the resistivity immediately after the bending test Respectively. In addition, as a result of the adhesion test between the substrate and the metal thin film, it was confirmed that the metal thin film was still strongly bonded to the substrate so that the metal thin film was not peeled off by the tape. 1.90J / the light is irradiated similarly to the results of the prepared metal thin film by cm ^2, the light is irradiated in the range of 1.24 to 2.57 J / cm ² both prepared sample, the light emission of the bulb stable both in the bending test of million times The resistivity increase rate was less than 60%, and it was confirmed that the adhesive strength test did not peel off the tape as immediately after the production.

(Example 2)

The procedure of Example 1 was repeated except that a polyimide substrate or a paper substrate was used instead of the polyethylene terephthalate substrate.

As a result of testing the resistivity, adhesion test and bending test of the samples prepared in Example 2, the same or similar results as those of the samples prepared in Example 1 were obtained regardless of the substrate. Figure 4 is an optical photograph of a sample made using paper as a substrate.

(Example 3)

Using the copper nanoparticles prepared in Preparation Example 2, a conductive ink composition was prepared in the same manner as in Example 1. The prepared conductive ink composition was applied on a polyimide plastic substrate to a thickness of 3 占 퐉 using a casting method. The dried coating film was subjected to light irradiation continuously for 1.5 msec at an intensity of 2.5 J / cm ² using the same light source as in Example 1 to conduct light sintering. It was confirmed that the metal thin film having a specific resistance of 9.0μΩ · cm by the optical sintering prepared, in Example 1, 1.24 to 2.57 J / cm ² results bending test is similar to light is irradiated with the light sintered metal thin film and the adhesive force between the test Results were obtained.

(Example 4)

25 g of copper nanoparticles prepared in Preparation Example 1 at a retention time of 2 minutes, 7 g of substance toluene as a non-aqueous solvent, and 0.2 g of BYK 130 as a polymeric binder were mixed and subjected to 3 roll milling to form a conductive paste composition . The prepared paste was applied on a polyimide substrate using a bar coating and dried.

Example 1 Similarly, using a light source having a wavelength band of 370-800 nm, and irradiated with light under the condition of strength and 1.5msec of 2.5J / cm ² in terms of strength and 1.5msec or 3.0J / cm ² conductive A metal thin film (thickness = 5 μm) was prepared. The thickness of the prepared metal thin film was 5 μm, and the resistivity of the metal thin film was 650 μΩcm under the light intensity of 2.5 J / cm ² and 1.5 msec, and it was confirmed that the metal thin film was not peeled off during the adhesion test. However, when the light irradiation intensity was 3.0 J / cm ² , the metal thin film was desorbed during the adhesion test between the substrate and the metal thin film.

(Example 5)

25 g of copper nanoparticles prepared in a retention time of 2 minutes in Production Example 1, 7 g of material toluene as a non-aqueous solvent, 1 g of an Applied Carbon Nano Technology (aspect ratio: ~ 1000) and 1 g of a polymer binder Were mixed and a three-roll milling was carried out to prepare a conductive paste composition having a uniform dispersed phase. The prepared paste was applied on a polyimide substrate using a bar coating and dried.

By irradiating a light under the conditions of the manufacturing coating film, 2.5J / cm ² intensity and conditions of 1.5msec, strength and 1.0msec of 3.0J / cm ² in terms of strength and 1.5msec or 3.0J / cm ² of, A metal thin film having a thickness of 10 탆 was prepared. 2.5J / cm ² of the optical device Students absent the specific resistance of the strength and condition of 1.5msec 9.38μΩcm was confirmed that the metal thin film is prepared was confirmed that the metal thin film when the adhesive strength test and the metal foil and the substrate is not desorbed. However, when the light irradiation intensity was 3.0 J / cm ² , the metal thin film was desorbed during the adhesion test between the substrate and the metal thin film irrespective of the irradiation time.

(Example 6)

20 g of copper nanoparticles prepared in Preparation Example 1 at a retention time of 2 minutes, 80 g of material toluene as a non-aqueous solvent, 1 g of an Applied Carbon Nano Technology (aspect ratio: ~ 1000) and BYK 130 0.2 g were mixed and three roll milling was carried out to prepare a conductive paste composition having a uniform dispersed phase. The prepared paste was applied on a polyimide substrate using a bar coating and dried.

In the prepared coating film, the light was irradiated under the conditions of strength and 1.0msec of 2.5J / cm ² in terms of strength and 1.5msec, the strength of 3.0J / cm ² and 1.5msec or 3.0J / cm ^2. The thickness of the prepared metal thin film was 30 탆, and the area was 25 cm ² .

It was confirmed that a metal thin film having a resistivity of 10.1 mu OMEGA cm was produced by photo-sintering under the conditions of the intensity of 2.5 J / cm < ² > and the duration of 1.5 msec. In addition, it was confirmed that the surface resistance was measured at five different surface areas of the prepared metal thin film, and the variation of the surface resistance was 5% or less. Thus, it was confirmed that the metal thin film having very uniform electrical characteristics was produced. It was confirmed that the metal thin film was not removed during the adhesion test. At this time, when the light irradiation intensity was 3.0 J / cm ² , the metal thin film was desorbed during the adhesion test between the substrate and the metal thin film irrespective of the irradiation time.

As a result of observation of the cross section of the metal thin film produced by light irradiation at ^2.5 J / cm ² in Example 6 with a scanning electron microscope, it was found that even in the case of a very thick thick metal thin film having a thickness of 30 μm, It was confirmed that the light sintering was uniformly performed as a whole in both the central region and the lower region adjacent to the substrate.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Those skilled in the art will recognize that many modifications and variations are possible in light of the above teachings.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (19)

a) preparing a conductive ink composition comprising metal nanoparticles, a non-aqueous organic binder and a non-aqueous solvent, the metal core being capped with a capping layer comprising an organic acid;
b) applying the conductive ink composition to an insulating substrate to form a coating film; And
c) irradiating the coating film with light so as to satisfy the following relational expression 1 to produce a conductive metal thin film;
Lt; RTI ID = 0.0 > 1, < / RTI >
(Relational expression 1)
I _LS ? I _c
(I _LS in the relational expression 1 is the intensity of the light irradiated onto the coating film, and I _c is the maximum intensity of the intensity of the non-aqueous organic binder remaining in the conductive metal thin film) The method according to claim 1,
in step (c), light is irradiated so as to satisfy the following relational expression 1-1.
(Relational expression 1-1)
I _LS & le; 2.6 (J / cm < ² &
(The definition of I _LS in Relation 1-1 is the same as Relation 1) 3. The method of claim 2,
Wherein the average diameter of the metal nanoparticles is 20 to 300 nm. 3. The method of claim 2,
wherein the step (c) comprises continuously irradiating light having a wavelength band of 200 to 800 nm. 5. The method of claim 4,
and the light is continuously irradiated for 1 to 2 msec in step c). The method according to claim 1,
The non-aqueous organic binders may be selected from the group consisting of polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), a self-crosslinkable acrylic resin emulsion, hydroxyethylcellulose, ethylhydroxyethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, methyl Cellulose, nitrocellulose, ethylcellulose, styrene butadiene rubber (SBR), copolymer of C1-C10 alkyl (meth) acrylate and unsaturated carboxylic acid, gelatin, Thixoton, starch, A mixture of ethyl cellulose and a phenolic resin, an ester polymer, a methacrylate polymer, a self-crosslinking (meth) acrylic acid copolymer, a copolymer having an ethylenic unsaturated group, Ethyl cellulose type, acrylate type, epoxy resin type, and mixtures thereof. Method of producing a conductive thin metal film. The method according to claim 6,
Wherein the conductive ink composition comprises 0.05 to 5 parts by weight of a non-aqueous organic binder and 20 to 800 parts by weight of a non-aqueous solvent based on 100 parts by weight of the metal nanoparticles. The method according to claim 1,
Wherein the conductive ink composition further comprises one or more selected nanostructures in the conductive nanowires, the conductive nanotubes, and the conductive nanorods. 9. The method of claim 8,
Wherein the thermal conductivity of the nanostructure is 50 W / mK or more. 9. The method of claim 8,
Wherein the nanostructure has an aspect ratio of 10 to 10000. 9. The method of claim 8,
The nanostructure may be one or more of single-walled carbon nanotubes, double walled carbon nanotubes, thin multi-walled carbon nanotubes, and multi-walled carbon nanotubes. Wherein at least two selected sintered conductive metal thin films are selected. 9. The method of claim 8,
Wherein the conductive ink composition contains 1 to 10 parts by weight of a nanostructure based on 100 parts by weight of the metal nanoparticles. 13. A conductive metal thin film produced by the method of any one of claims 1 to 12. A metal film on which a conductor including metal nanoparticles on a substrate is connected to each other to form a continuous body; And an organic binder mixed with the metal nanoparticles and binding the metal film and the substrate. 15. The method of claim 14,
Wherein the metal wiring is produced by photo-sintering of an ink containing a metal nanoparticle and a polymeric binder capped with a capping layer, the metal core comprising an organic acid, and the organic binder is a polymeric binder contained in the ink. 16. The method of claim 15,
Wherein the metal wiring contains 0.05 to 0.1 parts by weight of an organic binder based on 100 parts by weight of the metal nanoparticles. 15. The method of claim 14,
Wherein the conductor further comprises one or more selected nanostructures in the conductive nanowires, the conductive nanotubes, and the conductive nanorods. 18. The method of claim 17,
Wherein the metal wiring comprises 1 to 10 parts by weight of the nanostructure based on 100 parts by weight of the metal nanoparticles. 18. The method of claim 17,
The nanostructure may be one or more of single-walled carbon nanotubes, double walled carbon nanotubes, thin multi-walled carbon nanotubes, and multi-walled carbon nanotubes. Metal wiring selected more than one.

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