KR100819904B1 - Metallic ink, and method for forming of electrode using the same and substrate - Google Patents

Abstract

A metallic ink is provided to realize improved conductivity and adhesion to a substrate after ink jet patterning, and to prevent evaporation upon heat treatment at high temperature. A metallic ink comprises: metal oxide nanoparticles having a size of 1-100 nanometers; metal nanoparticles having a size of 1-100 nanometers; and partially polycondensed metal oxide nanoparticles having a size of 1-100 nanometers, wherein each type of nanoparticles are dispersed independently in a solvent. The partially polycondensed metal oxide nanoparticles is at least one selected from a metal alkoxide represented by the formula of Ma(OR)b (wherein M is a metal, R is H or a hydrocarbyl, and each of a and b is an integer or decimal greater than 0), an inorganic polycondensed polymer represented by the formula of MxOy(OR)z (wherein M is a metal, R is H or a hydrocarbyl, and each of x, y and z is an integer or decimal greater than 0), and a complex of a metal with a beta-diketone represented by the following formula 3, wherein each of R and R' represents H or a hydrocarbyl. The metal oxide nanoparticles are used in an amount of 0.01-30 wt% on the solid content basis.

Description

Metallic ink, electrode formation method and substrate using same {METALLIC INK, AND METHOD FOR FORMING OF ELECTRODE USING THE SAME AND SUBSTRATE}

1 is a graph of particle size distribution of Ag / Pd nanoparticle dispersions.

2 is a TEM photograph of an Ag / Pd nanoparticle dispersion.

3 is a photograph of Ag / Pd metal wiring formed through inkjet patterning.

4 is a SEM photograph of a metal wiring heat treated at 250 ° C.

5 is a SEM photograph of a metal wiring heat treated at 560 ° C.

The present invention relates to a metallic ink, and to an electrode forming method and a substrate using the ink. More particularly, the present invention relates to a metal oxide and / or a metal partial axis in forming a metallic ink in which nano-sized ultrafine metal particles are dispersed. By dispersing and containing the polymerized oxide in an independent form together with the ultrafine metal particles, a metallic ink capable of patterning by an inkjet printer, in particular, having excellent adhesion to a substrate, and an electrode forming method for patterning the ink with an inkjet printer and in the method The present invention relates to a substrate on which electrodes are formed.

With the development of the electronics industry, the metals are being used more and more. In particular, finely powdered metals are used for the purpose of expressing metallic texture or forming conductive wiring.

For example, various plastic electronic products such as mobile communication terminals and home appliances have been widely recognized as having a metallic color suitable for the appearance of the product, and thus metal powder is contained and coated in the paint. In particular, silver metallic color gives the product a refined and neat impression, and silver (Ag) is used a lot as it expresses a luxurious appearance.

In addition, since metal has excellent conductivity, it is used for the production of various electrode substrates printed on substrates such as plastics or glass substrates for conductive wiring and applied to PDPs (plasma display panels). In this case, the metal is powdered to a size of several micrometers to several tens of micrometers (μm) or more and used. Such a metal powder is mixed with an organic binder such as a photosensitive epoxy resin, pasted, and then printed on a substrate through a silk screen method, a lithography method, or the like. For example, the printing process may be described by first screen printing a metal paste composition on a surface of a glass substrate (substrate) to form a film. The formed film is finely patterned through a lithography process to form fine conductive wiring on the substrate. Next, the organic substrate is burned and removed at a high temperature of 500 ° C. to manufacture a substrate for electrodes having conductive wiring patterned thereon.

However, the above method has been attempted by a printing method using an ink jet printer in recent years due to the large device and complicated process. The inkjet printing technique has a high printing speed, a relatively simple apparatus, and is independent of the type of pattern to be printed. In addition, the thickness of the printed line can be freely implemented from fine lines to thick lines, and the process is simple, thereby reducing manufacturing cost and innovating the manufacturing process. Because of these advantages, inkjet printing is expected to replace screen printing or lithography.

At this time, the metallic ink used in the ink jet printer should satisfy the ink characteristics of the ink jet so that the nozzle is not clogged. Specifically, the metal should be excellent in dispersibility so that the nanoparticles are made into nano particles and have no agglomeration phenomenon.

Recently, as part of the introduction of a printing technique through inkjet technology, a solution in which silver particles of less than 100 nanometers are dispersed has been developed and applied to the production of PDP. Research on the preparation of ultrafine metal particles having excellent dispersibility has been carried out since the 1980s Langmuir, 1996, 12, 4723; Chem. Rev. 2004, 104, 3893; J. Phys. Chem. B., 1988, 102, 8378; J. Am. Chem. Soc. 1999, 121, 882; J. Phys. Chem. B., 1999, 103, 5488, and many publications and patents, such as Korean Patent Publication No. 10-2002-7007534. The production method can be largely divided into a chemical reduction method using a reducing agent and a gas evaporation method obtained by condensation after evaporating the metal in the gas phase. The ultrafine metal particles thus prepared are stirred with a solvent, a resin, a dispersant, and the like, and then applied with ultrasonic waves, dispersed and processed by a ball mill, a sand mill, or the like, to prepare a ultrafine metal dispersion.

Among the high concentration and low viscosity metallic inks (metal ultrafine particle dispersions) obtained as described above, silver (Ag) inks are most usefully used for forming electrodes through inkjet patterning of PDPs or other displays because of their excellent conductivity.

In addition, Korean Patent Laid-Open No. 10-2002-0074167 discloses an ink made of ultrafine metal dispersion liquid and a method for manufacturing the same as satisfying ink characteristics for inkjet. In addition, Korean Patent Laid-Open Publication No. 10-2002-0080393 discloses a method of forming an electrode of a flat panel display using the ink disclosed in the above-described patent and forming an inkjet printer.

However, the ultrafine metal dispersion (metallic ink) according to the prior art has a problem that the adhesion to the substrate is significantly lowered. The surface of metal nano-sized particles is chemically unstable and easily denatures in air. As a result, the patterned conductive wiring changes color with time, and in particular, shows a sudden drop in adhesion. As such, when the adhesive force is lowered, desorption of the metal conductive wiring occurs, which causes a fatal defect as an electrode, which becomes a factor that makes it impossible to apply the metallic ink to the PDP process.

In addition, in general, the metallic ink is improved in adhesion and conductivity at the same time when the heat treatment at a high temperature, the metallic ink according to the prior art has a problem that the evaporation phenomenon occurs during high temperature treatment.

Therefore, it is possible to print with an inkjet printer which is advantageous for cost reduction and productivity improvement. Although a metallic ink in which nano-sized metals are dispersed has been developed, it is impossible to be practically applied without improving the adhesion problem after inkjet patterning. There is an urgent need for metallic inks.

The present invention has been invented to solve the problems of the prior art as described above, and has an object to provide a metallic ink having improved adhesion, and an electrode forming method and a substrate using the same by providing a means for improving adhesion between the substrate and the substrate. have.

In addition, another object of the present invention is to provide a metallic ink which has no evaporation during heat treatment at high temperature and has improved adhesion and conductivity, and an electrode forming method and a substrate using the same.

In order to achieve the above object, the present invention, at least one oxide selected from metal oxide nanoparticles of 100 nanometers or less size and metal partial polycondensation oxide, and metal nanoparticles of 100 nanometers or less dispersed in an independent form in a solvent To provide a metallic ink.

The present invention also provides a metallic ink in which at least one oxide selected from metal oxide nanoparticles having a size of 100 nanometers or less and metal partial polycondensation oxide and metal nanoparticles having a size of 100 nanometers or less are dispersed in a solvent in an independent form. Making a step;

Patterning the metallic ink on a substrate with an ink jet printer;

And heat-treating the patterned metallic ink.

In this case, the metal nano-particles are alloys composed of a first metal having a higher conductivity than the second metal and a second metal that forms an alloy with the first metal to impart thermal stability, or the first metal and the second metal particles Preference is given to mixing.

In addition, the heat treatment step is preferably carried out at 60 ℃ or more, more preferably to heat treatment at a high temperature of more than 450 ℃ to obtain excellent conductivity and adhesion and strength.

In addition, the present invention provides a substrate on which an electrode is formed by the above electrode forming method.

According to the present invention, the adhesion to the substrate is increased by the metal oxide and / or the metal partial polycondensation oxide. In addition, when the metal nanoparticles are composed of an alloy (or mixed), the evaporation phenomenon is improved to allow heat treatment at a high temperature, thereby improving adhesion and conductivity.

Hereinafter, the present invention will be described in more detail.

The present inventors have been continually researching to solve the problem of deterioration in adhesion force of the conventional metallic ink and the problem of causing fatal defects in the patterned metal wiring by evaporation of the metal during high temperature heat treatment. In this process, when the metal nanoparticles were dispersed independently, it was found that they do not generate agglomeration, maintain fluidity necessary for inkjet, and have excellent ink properties. As the nanoparticles, metal oxides and / or metal partial polycondensation oxides ( That is, when the partial condensate of the metal oxide) is independently dispersed together with the metal nanoparticles, it has been found that the adhesion force after the patterning is dramatically increased and the present invention has been completed. In addition, a metal of the metal nanoparticles is composed of an alloy, but a first metal capable of satisfying the conductivity and a second metal which is less conductive than the first metal but forms an alloy with the first metal to impart thermal stability. In the case of high temperature treatment, the evaporation phenomenon was solved, and when the high temperature treatment was performed, it was found that the conductivity and adhesion were improved.

The metallic ink according to the present invention is a form in which one or two or more oxides selected from metal oxide nanoparticles and metal partial polycondensation oxides, and metal nanoparticles are independently dispersed in a solvent, A) metal oxide nanoparticles and / or B A) metal partial polycondensation oxide, C) metal nano fine particles, and D) dispersion.

According to a preferred embodiment of the present invention, the metal nano-particles (C) is an alloy or a mixture of single metals, the first metal having a high conductivity, and the second metal forming an alloy with the first metal to impart thermal stability. Or a mixture of the first metal and the second metal fine particles.

The metal oxide nanoparticles (A) has a size of 100 nm (nanometer) or less, specifically 1 nm to 100 nm. Preferably, the ink jet ejection has a size of 50 nm or less as a size that can be performed smoothly. At this time, when the size of the metal oxide nanoparticles (A) is too large exceeding 100 nm, the nozzle of the inkjet printer may be clogged, which is not preferable.

The metal elements constituting the metal oxide nanoparticles (A) as described above are group 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B, transition metal, lanthanide And actinium groups, and the like (metals and semimetals) included in the present invention, for example, Group 1A (alkali metal) such as Li, Na, K, Rb, Cs, Fr; 1B group, such as Cu, Ag, Au; Group 2A (alkaline earth metals) such as Be, Mg, Ca, Sr, Ba, and Ra; 2B group, such as Zn and Cd; Group 3A, such as Sc and Y; 3B group, such as Al, Ga, In; 4A group, such as Ti, Zr, and Hf; 4B group, such as Si, Ge, Sn, and Pb; Group 5A, such as V, Nb, and Ta; Group 5B such as Sb and Bi; Transition metals such as Mn, Ni, Fe, Cr, Co, Cu, Mo, W, Te, Re, Ru, Os, Rh, Ir, Pd, Pt; Lanthanides such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; Actinium group metal elements, such as Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, etc. are mentioned. Preferably, the metal oxide nanoparticles (A) have good adhesion to the substrate, and the metal oxide nanoparticles (A) include silicon (Si), bismuth (Bi), magnesium (Mg), yttrium (Y), cerium (Ce), and titanium (Ti). ), Zirconium (Zr), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), neodymium (Nd), copper (Cu), At least one selected from the group consisting of oxides such as silver (Ag), zinc (Zn), aluminum (Al), gallium (Ga), indium (In), tin (Sn), and antimony (Sb) It can be mixed and used. Specific examples include silicon oxide (SiO ₂ , silica), bismuth oxide (BiO, Bi ₂ O 3, Bi ₂ O ₅ ), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), titanium oxide (TiO ₂ ), One or a mixture of two or more selected from the group consisting of zinc oxide (ZnO ₂ ), antimony oxide (Sb ₂ O ₃ ), magnesium oxide (MgO), calcium oxide (CaO), iron oxide (FeO ₂ ), and the like may be used. . And it is used in the form of dispersed in the solvent to the size of less than 100 nanometers.

The metal partial polycondensation oxide (B) can be used as long as it can give adhesion to the substrate, and for example, one or two or more selected from metal alkoxides represented by the following formula (1) or the like, or the metal One or two or more selected from alkoxides can be used a condensation product obtained by carrying out a hydrolysis and condensation reaction.

[Formula 1]

M _a (OR) _b

(In the above formula, M is a metal, R is hydrogen or a hydrocarbon (alkyl group, aryl group, etc.) with various functional groups in the chain, and a and b are integers or decimals greater than 0.)

In addition, the metal partial condensation polymerization oxide (B) may be usefully used an inorganic condensation polymerization polymer represented by the following formula (2).

[Formula 2]

M _x O _y (OR) _z

(Wherein, M is a metal, R is hydrogen or a hydrocarbon (alkyl group, aryl group, etc.) with various functional groups in the chain, x, y, z is an integer or prime number greater than zero.)

In addition, the metal partial condensation polymerization oxide (B) may be usefully used as a complex of the metal (M) and beta diketones represented by the formula (3) below.

[Formula 3]

(Wherein R and R 'are hydrogen or hydrocarbons having various functional groups in the chain (alkyl groups, aryl groups, etc.))

In the present invention, the metal partial polycondensation oxide (B) is a metal alkoxide of the formula (1); Inorganic condensation polymer of Formula 2; And a metal (M) and a complex of Formula 3; may be usefully used, and two or more thereof may be mixed. In other words, a mixture of a metal alkoxide and an inorganic condensation polymer, a mixture of a metal alkoxide (or an inorganic condensation polymer) and a complex, or a mixture of these three kinds can be used. The metal (M) constituting the metal partial polycondensation oxide (B) is a group 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B, or transition metal. And metal elements such as lanthanide and actinium, preferably Si, Ti, Bi, Mg, Y, Ce, Zr, V, Cr, Mn, Fe, Co, Ni, Nd, Cu, Ag, Zn , Al, Ga, In, Sn and Sb is any one selected.

In the metallic ink according to the present invention, the metal oxide nanoparticles (A) and / or the metal partial condensation polymerization oxide (B) described above may be contained in an amount of 0.01% to 30% based on the total weight of the solid content. Specifically, in the total solids (A + B + C, A + C or B + C) including the metal oxide nano fine particles (A) A and / or B (A, B, or A + B) is 0.01% by weight to It is preferable to be composed of 30% by weight. Preferably 0.1% to 10% is good. At this time, if the weight ratio of the metal oxide nanoparticles (A) and / or the metal partial polycondensation oxide (B) to the metal nanoparticles (C) is too high, the adhesion is increased, but the conductivity of the inkjet patterned conductive wiring is reduced, and if it is too small, It is difficult to achieve good adhesion.

The metal nanoparticles (C) have a size of 100 nm (nanometer) or less, specifically 1 nm to 100 nm. As the metal nanoparticles (C), for example, silver (Ag), gold (Au), platinum (Pt), copper (Cu), palladium (Pd), nickel (Ni) and the like may be used. It may be, preferably an alloy composed of two or more metals, or a mixture of two or more metals.

In this case, when the metal nanoparticles (C) is an alloy, a metal (first metal) having a relatively higher conductivity than other metals among various kinds of metals, and having a lower conductivity than the first metal, the first metal It is preferred to be composed of a metal (second metal) which forms an alloy with and gives thermal stability. In addition, even in the case of mixing two or more kinds, it is preferable that a mixture of the first metal having a relatively higher conductivity than other metals and a second metal forming an alloy with the first metal to impart thermal stability. In this case, the first metal may be any one selected from silver (Ag), gold (Au), platinum (Pt), copper (Cu), and the like. The second metal may include palladium (Pd) and nickel (Ni). Any one selected from the like can be used. In addition, the second metal is more preferably a metal without evaporation even at a temperature of 450 ℃ or more.

According to a preferred embodiment of the present invention, the metal nano fine particles (C) may be usefully used as an alloy including at least silver (Ag) having excellent conductivity and advantageous properties in terms of price, and more preferably silver (Ag). ) And an alloy composed of palladium (Pd) (Ag / Pd alloy) is recommended. As such, when the metal nanoparticles (C) are made of an alloy, the metal nanoparticles (C) are directly made of nano-sized alloy particles and then dispersed in the ink. In addition, when each single metal nanoparticle is mixed and dispersed in the ink at an appropriate ratio, the ink in which each single metal nanoparticle is mixed and dispersed is converted into an alloy in the heat treatment process after inkjet patterning.

When the metal nano-particles (C) is composed of an alloy (or mixed) as described above, the first metal having a high conductivity, and the second metal formed of an alloy with the first metal to impart thermal stability, the first The metal satisfies the basic conductivity required in the conductive wiring, and the second metal enables heat treatment without evaporation even at a high temperature of 450 ° C or higher, specifically 450 ° C to 650 ° C. That is, the second metal prevents the evaporation phenomenon generated during the high temperature treatment to enable a high temperature treatment, and the adhesion to the substrate is increased by the high temperature treatment. In addition, the high temperature treatment allows further improved conductivity.

For example, when the metal nanoparticles (C) are Ag / Pd alloy nanoparticles, the content of Pd (second metal) is 0.05% to 50% based on the total weight of the metal (Ag + Pd). Preferably 0.1% -50% is good. If the content of Pd is less than 0.1%, an evaporation phenomenon may occur when the conductive wire is heat-treated at 450 ° C. or higher, and the adhesion and the conductivity of the wire may be significantly reduced. When the Pd content is 0.1% or more, evaporation is eliminated and as palladium increases, thermal stability of the conductive wiring and adhesion to the substrate are remarkably improved. In addition, when the content of Pd exceeds 50%, the conductivity of the silver wiring may be significantly reduced due to the low conductivity of Pd. Therefore, at a high temperature of 450 ° C. or higher, it is preferable to contain 0.1% to 50% of Pd in terms of thermal stability and conductivity.

In addition, according to the present invention, as described above, the content of Pd, that is, the content of the second metal, may be adjusted within an appropriate range to adjust conductivity and thermal stability required for the applied product. That is, in the case of products requiring more thermal stability than conductivity, the content of Pd may be increased.

The dispersion (D) is to allow the metal oxide nanoparticles (A), the metal partial polycondensation oxide (B), and the metal nanoparticles (C) described above to be independently dispersed in a solvent. Is done.

As a dispersing agent of the said dispersion (D), it is selected from the organic substance which has a functional group which can form a complex on a metal surface, For example, alkyl amine, carboxylic acid amide, amino carboxylate, sodium citrate salt, etc. Can be used. At this time, the alkyl group of the alkyl amine has 4 to 20, preferably 4 to 12 carbon atoms to sufficiently disperse the metal nanoparticles (C) in a nonpolar solvent. In addition, polyvinylpyrrolidone (PVP) having a molecular weight (Mw) of 1,000 to 40,000, preferably 10,000 to 20,000, or polyvinyl alcohol having a molecular weight (Mw) of 1,000 to 40,000, preferably 10,000 to 20,000 may be used. Can be. As a commercial product, dispersants such as BYK-108, BYK-1000 or BYK-antiterra-U of BYK of Germany may be used alone or in combination of two or more thereof.

The solvent of the dispersion (D) is at least selected from solvents such as C6-C20 nonpolar hydrocarbons, water and cellosolves or polar alcohols, depending on the characteristics of the surface-modified surfactant of the metal nanoparticles (C). One kind can be used.

The metallic ink of the present invention may be prepared by first preparing a metal nanoparticle dispersion and then mixing and dispersing a powder of the metal oxide nanoparticles (A) and / or a metal partial polycondensation oxide (B) or a dispersion thereof. In addition, the preparation of the metal nanoparticle dispersion may be prepared using a known method. Preferably it is prepared using a liquid phase reduction method. At this time, in the manufacturing process, the viscosity is 1 to 100 mPa · s, preferably 1 to 50 mPa · s, and the surface tension is 25 to 80 mN / m, preferably 30 to 60 mN / m, so that the solid content is the total weight of the ink. It is prepared to be 1 to 70%, preferably 10 to 55% as a standard. Thereby, the ink characteristic which can be patterned by an inkjet printer is satisfied.

The metallic ink of the present invention described above can be usefully used in the electronic industry. In particular, the substrate may be used for conductive wiring or metallic texture by various printing techniques on substrates for manufacturing electrodes (plastic or glass) of various panels such as PDPs, as well as cases constituting various plastic electronic products such as mobile communication terminals and home appliances. Can be.

On the other hand, the electrode forming method according to the present invention has a process in which the conductive ink is formed by printing at least one or more times of the metallic inks described above on the surface (either one or both sides of the substrate) of a substrate selected from a plastic or a glass substrate. . At this time, the conductive wiring is patterned by an inkjet printing method, and then heat is irradiated and heat treated. The heat treatment process may be carried out at a temperature of 60 ℃ or more. Preferably, the heat treatment is performed at a temperature of 120 ° C. or higher, specifically 120 ° C. to 650 ° C., and more preferably at a high temperature of 450 ° C. or higher, specifically at a high temperature of 450 ° C. to 650 ° C. As described above, when heat treated at high temperature, the adhesion as well as the conductivity are improved.

In addition, the substrate according to the present invention has an electrode (conductive wiring) formed on the substrate by the electrode forming method, which is usefully used as an electrode of various electronic products such as a PDP and a semiconductor element.

Hereinafter, specific test examples and comparative examples of the present invention will be described. The following examples are merely provided to explain the present invention in more detail, whereby the technical scope of the present invention is not limited.

Example 1

(1) Preparation of Ag Nanoparticle Dispersion

An aqueous metal compound solution was prepared by dissolving 236.247 g of AgNO _{3 in} tertiary distilled water such that the metal concentration was 30% (the weight ratio of the metal in the solution). Next, polyvinylpyrrolidone (PVP, Mw = 40,000) was added to 10% of the metal weight (Ag: PVP = 0.1: 1) under nitrogen atmosphere and stirred until completely dissolved, and then the temperature of the solution was increased. It was kept at 60 ° C. 4L of a mixed solution of ethanol and decane (2: 8 ratio) was added to the solution thus prepared, followed by adding 2 mole of potassium borohydride as a reducing agent to proceed with a metal reduction reaction to prepare an Ag ultrafine dispersion. In addition, BYK-108 (by BYK, Germany) and PVP were added to this dispersion. Thus, the dispersion formed after the reduction reaction was about 6L to maintain a uniform dispersion of Ag nanoparticles. Next, in order to separate the Ag nanoparticle powder from the dispersion, ethanol was added to change the polarity to separate. And impurities were removed by washing several times with distilled water and acetone. The fine particles recovered through the washing process were dispersed using a mixed solvent of hexane, decane, and toluene of hydrocarbon series. At this time, the Ag nanoparticles have a particle size of about 3 ~ 7nm, uniformly dispersed in a solvent in a completely isolated state of the particles. The dispersion contained 53.4% by weight of Ag nanoparticles based on the total weight of the dispersion, and had a viscosity of 8.7 mPa · S capable of inkjet patterning at 25 ° C. In addition, it was confirmed that the Ag ultra-fine particle dispersion prepared as described above was stable even after 30 days at room temperature without precipitation phenomenon.

(2) Preparation of Pd Nano Particulate Dispersion

Using Pd (NO ₃ ), the Pd ultra-fine particle dispersion was prepared in the same manner as the preparation method of Ag nanoparticle dispersion described above. Pd ultrafine particles have a particle size of about 5 ~ 10nm, uniformly dispersed in a solvent in a completely isolated state of the particles. This dispersion had 45 wt% of the Pd nanoparticles based on the total weight of the dispersion, and had a viscosity of 13.4 mPa · S at 25 ° C. In addition, it was confirmed that the prepared Ag ultra-fine particle dispersion shows a stable state without precipitation phenomenon even after 30 days at room temperature.

(3) ink manufacturing

The Ag nanoparticle dispersion and Pd nanoparticle dispersion prepared above were mixed, but were mixed so that Pd was 0.3% based on the weight of metal (sum of Ag + Pd). FIG. 1 is a particle size distribution graph of the Ag / Pd nanoparticle dispersions thus mixed using a particle size analyzer (Japanese microtrek product, model UPA-150), and FIG. 2 is a TEM image of the Ag / Pd nanoparticle dispersions. . As shown in Figures 1 and 2, it was found that the metal particles are uniformly dispersed in a completely isolated state without agglomeration with each other.

Next, an inkjet was added to the mixed solution so that a silica sol (Japan, Nissan Chemicals, trade name: Snowtex) mixed with silica having a diameter of less than 50 nm was added to 3% of the weight of solid Ag and Pd metal (sum of Ag + Pd). Ink for ink was prepared.

(4) specimen manufacture

The prepared ink was patterned on a glass substrate for PDP by mounting a spectra SE head of Spectra of USA in an inkjet model 70 system of Litrex in USA. In forming the wiring through inkjet patterning, two overlap printings were performed to obtain a constant thickness within a total length of 1160 mm and a thickness of 70 to 90 μm. It can be seen that the ink is effectively ejected and patterned without clogging the nozzle. The photo of the Ag / Pd metal wiring formed through the inkjet patterning as shown above is shown in FIG. 3.

Next, the specimens according to the present embodiment were completed by heat treatment at 250 ° C. and 560 ° C. with respect to the patterned metal wires. At this time, the heat was irradiated for 30 minutes at 250 ℃, the heat was irradiated for 20 minutes at 560 ℃. FIG. 4 is a SEM photograph of the metal interconnection heat-treated at 250 ° C., and FIG. 5 is a SEM photograph of the metal interconnection heat-treated at 560 ° C.

(5) Evaluation of adhesion, conductivity, thermal stability

The adhesion, conductivity and chemical stability of the specimens prepared as described above were evaluated. Adhesion was determined by attaching 3M tape (presure sensitive tape, manufactured by 3M, USA) to metal wires formed after patterning / heat treatment, and then visually observing the damage of the wires when peeled off. Measurement was performed using a probe tester (Loresta MP MCP-T350). And thermal stability was evaluated by measuring and comparing the light transmittance of the specimen after patterning / heat treatment, and whether the metal evaporation phenomenon occurs at high temperature.

The above results are shown in the following [Table 1] and [Table 2].

[Examples 2 to 5]

Pd content of 1% (Example 2), 5% (Example 3), 10% (Example 4), 30% (Example 5) in mixing Ag nanoparticle dispersions and Pd nanoparticle dispersions during ink preparation Was carried out in the same manner as in Example 1 except that it was The results are shown in the following [Table 1] and [Table 2].

Example 6

The same process as in Example 1 was carried out except that the Pd nano fine particle dispersion was not mixed during ink preparation. The ink of the present embodiments was made of a mixture of Ag nano-particle dispersion and a silica sol, it can be seen that in the inkjet patterning to form a metal wiring by effectively ejecting without clogging the nozzle. However, the evaporation phenomenon of the metal particles occurred during the heat treatment at a high temperature of 560 ℃, in this case, the conductivity was not realized, it was found that the high temperature heat treatment is difficult to apply. The results are shown in the following [Table 1] and [Table 2].

[Examples 7 to 9]

The same process as in Example 1 was carried out except that silica sol was not mixed during ink preparation. That is, the ink of the present embodiments is composed of a mixture of Ag nanoparticle dispersion and Pd nanoparticle dispersion. At this time, the ink was prepared by changing the content of Pd in the metal (Ag + Pd) to 0.3% (Example 7), 5% (Example 8), 30% (Example 9). It was found that the prepared ink was effectively discharged without ink clogging in inkjet patterning to form metal wiring. And it can be seen that there is no evaporation phenomenon even in the heat treatment of 560 ℃ as well as 250 ℃. The results are shown in the following [Table 1] and [Table 2].

Example 10

First, Ag nanoparticles were prepared as in Example 1.

And terraethoxysilanes [TEOS; To 20 g of Teraethoxysilane (Japan, Toshiba Chemical, trade name: TSL8124)] 20 g of Hexyltrimethoxysilane (Japan, Toshiba Chemical, trade name: TSL8241)] was added and stirred, and 20 g of dodecane was further added. 10 g (20 wt% aqueous solution) was added thereto, and a silica partial condensate was prepared through ball milling at room temperature. After removing the water layer, the silica partial condensate present in the organic layer was concentrated to a dry weight of 30% by weight. It was found that the prepared silica partial condensate was uniformly dispersed in the solvent.

Next, 3% of the silica partial condensate was added to the Ag ultra-fine particle powder relative to the metal, and then stirred and dispersed using a tetradecane solvent. The dispersed solution contained 52.3 wt% Ag metal and had a viscosity of 11.4 mPa · S at 25 ° C. The dispersed solution was inkjet patterned in the same manner as in Example 1, and then heat-treated at 250 ° C and 560 ° C to form metal wirings. At this time, the evaporation phenomenon of the metal particles occurred during the heat treatment at a high temperature of 560 ℃, in this case, it was found that the application of high temperature heat treatment is difficult because the conductivity is not implemented. The results are shown in the following [Table 1] and [Table 2].

Example 11

After preparing the silica partial condensate in the same manner as in Example 10, and added to the Ag nanoparticle powder and Pd nanoparticle powder prepared in the same manner as in Example 1 to 3% by weight, dispersing solvent It was stirred and dispersed using tetra decane as a. The Ag / Pd metal of the dispersed solution contained 51.8 wt%, and the viscosity was 13.4 mPa · S at 25 ° C. And Pd was included in 0.5% by weight of the total metal. The dispersed solution was inkjet patterned in the same manner as in Example 1, and then heat-treated at 250 ° C and 560 ° C to form metal wirings. The results are shown in the following [Table 1] and [Table 2].

[Examples 12 and 13]

First, Ag nano fine particles and Pd nano fine particle dispersions were prepared as in Example 1.

6-methyl-2,4-heptanedione and titanium isopropoxide were mixed in a 4: 1 equivalent ratio in a round bottom flask of 500 ml. . Next, a mixed solvent of ethanol / hexane / tetradecane (10/15/75) was added thereto, followed by heating and stirring with reflux for 20 hours under a nitrogen atmosphere at 70 ° C. Thereafter, the mixture was heated and stirred for an additional 2 hours without using Reflux to substantially remove the alcohol and hexane present in the mixed solvent. The obtained complex solution of Titanium and 6-Methyl-2,4-heptanedione (Titanium heptanoate solution) was maintained in a non-polar solvent, was converted to Titanium oxide through heat treatment at 250 ℃, the content was confirmed to be 13.5%.

Next, the Ag nanoparticle dispersion and Pd nanoparticle dispersion were mixed at a ratio of 99.7: 0.3, and then a complex solution of Titanium and 6-Methyl-2,4-heptanedione dispersed in the nonpolar solvent was added to Ag / 1% (Example 12) and 3% (Example 13) were added to Pd nanoparticles by weight and mixed and stirred. The Ag / Pd metal in this mixed dispersion solution (ink) contained 53.5 wt% and 52.9 wt%, respectively. Moreover, the viscosity showed 9.85 mPa.s and 10.4 mPa * s, respectively, and the viscosity suitable as an inkjet ink. As a result of performing inkjet patterning on the dispersion solution thus prepared in the same manner as in Example 1, uniform metal wiring was effectively formed on the glass substrate without nozzle clogging. And it can be seen that there is no evaporation phenomenon in the high temperature heat treatment of 250 ℃ and 560 ℃, and the physical properties such as adhesion. The results are shown in the following [Table 1] and [Table 2].

Comparative Example 1

Ag ultrafine powder was prepared in the same manner as in Example 1, and then uniformly stirred and dispersed in a tetradecane solvent to prepare Ag metal ink. The prepared Ag ink contained 54 wt% and exhibited a viscosity of 9.3 mPa · S at 25 ° C. After inkjet patterning of the ink in the same manner as in Example 1, heat treatment was performed at 250 ° C and 560 ° C to form a metal wiring, and then the physical properties were compared with those of the examples.

Although the specimen according to this comparative example formed a uniform metal wire on the glass substrate without clogging the nozzle during patterning, the conductivity was not realized due to evaporation during heat treatment at a high temperature of 560 ° C. It can be seen that the detached. The results are shown in the following [Table 1] and [Table 2].

        <Evaluation result of adhesion and conductivity of metal wiring>  division  metal ratio 250 ℃ * 30min 560 ℃ * 20min Specific resistance (1 × 10 ^-6 Ωcm) Adhesion Specific resistance (1 × 10 ^-6 Ωcm) Adhesion Example 1 Ag / Pd (99.7 / 0.3) S 8.98 △ 3.54 ◎ Example 2 Ag / Pd (99/1) S 10.4 ○ 3.87 ◎ Example 3 Ag / Pd (95/5) S 17.6 ○ 5.08 ◎ Example 4 Ag / Pd (90/10) S 28.6 ○ 8.5 ◎ Example 5 Ag / Pd (70/30) S 86.5 ○ 40.3 ◎ Example 6 Ag 100% S 4.85 ○ Not measurable X Example 7 Ag / Pd (99.7 / 0.3) 4.98 X 3.64 △ Example 8 Ag / Pd (95/5) 9.75 X 4.97 △ Example 9 Ag / Pd (70/30) 60.3 X 42.5 ◎ Example 10 Ag 100% Axis S 4.9 △ Not measurable ◎ Example 11 Ag / Pd (99.5 / 0.5) Shaft S 5.56 △ 4.01 ◎ Example 12 Ag / Pd (99.7 / 0.3) T 7.34 ○ 3.57 ◎ Example 13 Ag / Pd (99.7 / 0.3) T 8.91 ○ 4.09 ◎ Comparative Example 1 Ag 100% 4.5 X Not measurable X

In the adhesion evaluation of the above [Table 1], the desorption of more than 80% X, 10 ~ 20% desorption is △, less than 10% desorption is ○, non-desorption is represented by ◎.

      <Evaluation of Transmittance and Thermal Stability of Metal Wiring>  division  metal ratio 250 ℃ * 30min 560 ℃ * 20min Transmittance (%) Thermal stability Transmittance (%) Thermal stability Example 1 Ag / Pd (99.7 / 0.3) S 9.5 Good 11.8 Good Example 2 Ag / Pd (99/1) S 9.3 Good 11.7 Good Example 3 Ag / Pd (95/5) S 8.5 Good 11.4 Good Example 4 Ag / Pd (90/10) S 8.6 Good 10.8 Good Example 5 Ag / Pd (70/30) S 7.9 Good 9.7 Good Example 6 Ag 100% S 9.6 Good 44.5 Evaporation occurs Example 7 Ag / Pd (99.7 / 0.3) 9.4 Good 11.5 Good Example 8 Ag / Pd (95/5) 8.7 Good 11.3 Good Example 9 Ag / Pd (70/30) 7.6 Good 9.6 Good Example 10 Ag 100% Axis S 9.4 Good 45.4 Evaporation occurs Example 11 Ag / Pd (99.5 / 0.5) Shaft S 9.4 Good 11.3 Good Example 12 Ag / Pd (99.7 / 0.3) T 8.2 Good 10.9 Good Example 13 Ag / Pd (99.7 / 0.3) T 7.8 Good 10.7 Good Comparative Example 1 Ag 100% 9.3 Good 50.2 Evaporation occurs

In Tables 1 and 2 above, "S" is silica (SiO ₂ ), and "axis S" is partially condensed silica (SiO ₂ ). And "T" is a complex of titanium and 6-methyl-2,4-heptanedione.

As shown in Table 1, it can be seen that the embodiments of the present invention significantly increased the adhesive force than the conventional comparative example. And compared with the case where the metal oxide nanoparticles or the metal partial condensation oxide were added (Examples 1-5) without the addition (Examples 7-9) from the comparison result of Examples 1-5 and Examples 7-9. It can be seen that improved adhesion even at a low temperature of 250 ℃. In addition, it can be seen from the results of Examples 1 to 5 that the adhesion and conductivity are simultaneously improved when heat treated at a high temperature. In addition, even when the metal oxide nanoparticles or the metal partial condensation oxide were not added from the comparison results of Example 9 and Comparative Example 1, as shown in Example 9, when Pd is contained at a high rate and heat-treated at high temperature, it has excellent adhesion. Able to know.

In addition, as shown in Table 2 above, when the metal nanoparticles are made of an alloy (Ag / Pd) (Examples 1 to 5, Examples 7 to 9, and Example 11) of a single metal (implementation It can be seen that evaporation does not occur at a high temperature of 560 ° C. due to excellent thermal stability compared to Example 6, Example 10, and Comparative Example 1).

In addition, in Examples 12 and 13 to which the complex is applied, it can be seen that even when a small amount of Pd is contained, it has excellent adhesion even by heat treatment at 250 ° C.

As described above, the present invention has the effect of increasing the adhesion to the substrate by the metal oxide nanoparticles and the metal partial polycondensation oxide while being patterned by the inkjet printer. In addition, the present invention is improved the evaporation phenomenon is possible to heat treatment at a high temperature, thereby has the effect of further improving the adhesion and conductivity.

Claims (11)

1 to 100 nanometers of metal oxide nanoparticles, 1 to 100 nanometers of metal nanoparticles, and 1 to 100 nanometers of metal partial polycondensation oxide are dispersed in a solvent in an independent form, The metal partial polycondensation oxide is a metal alkoxide represented by the following formula (1); Inorganic condensation polymer represented by Formula 2 below; And a complex of a metal and betadiketones represented by Formula 3 below; The metal oxide nano fine particles have a content of 0.01% to 30% based on the weight of solids. [Formula 1] M _a (OR) _b (Wherein M is a metal, R is hydrogen or a hydrocarbon, and a and b are integers or decimals greater than zero) [Formula 2] M _x O _y (OR) _z (Wherein M is a metal, R is hydrogen or a hydrocarbon and x, y, z are integers or decimals greater than zero). [Formula 3]

(Wherein R and R 'are hydrogen or a hydrocarbon) The method of claim 1, The metal elements of the metal oxide nanoparticles may be selected from Group 1A, 1B, 2A, 2B, 3A, 3B, 4A, 4B, 5A, 5B, transition metals, lanthanides and actinides. Characteristic metallic ink. delete delete The method of claim 1, The metal nanoparticles are made of an alloy composed of a first metal and a second metal, or a mixture of the first metal and the second metal, The first metal is any one selected from silver (Ag), gold (Au), platinum (Pt) and copper (Cu), and the second metal is any one selected from palladium (Pd) and nickel (Ni). Characteristic metallic ink. Metal partial polycondensation oxide of 1 to 100 nanometers and metal nanoparticles of 1 to 100 nanometers in size are dispersed in a solvent, The metal partial polycondensation oxide is a metal alkoxide represented by the following formula (1); Inorganic condensation polymer represented by Formula 2 below; And a complex of a metal and betadiketones represented by Formula 3 below; The metal partial polycondensation oxide content of the metallic ink, characterized in that 0.01% to 30% by weight of solids. [Formula 1] M _a (OR) _b (Wherein M is a metal, R is hydrogen or a hydrocarbon, and a and b are integers or decimals greater than zero) [Formula 2] M _x O _y (OR) _z (Wherein M is a metal, R is hydrogen or a hydrocarbon and x, y, z are integers or decimals greater than zero). [Formula 3]

(Wherein R and R 'are hydrogen or a hydrocarbon) delete The method of claim 6, The metal nanoparticles are made of an alloy composed of a first metal and a second metal, or a mixture of the first metal and the second metal, The first metal is any one selected from silver (Ag), gold (Au), platinum (Pt) and copper (Cu), and the second metal is any one selected from palladium (Pd) and nickel (Ni). Characteristic metallic ink. In the electrode forming method, Preparing the metallic ink according to any one of claims 1, 2, 5, 6 and 8; Patterning the metallic ink on a substrate with an ink jet printer; And heat-treating the patterned metallic ink. The method of claim 9, In the heat treatment step, the electrode forming method, characterized in that the heat treatment at a temperature of 60 ℃ ~ 650 ℃. In the substrate on which the electrode is formed, The said electrode was formed by the electrode formation method of Claim 9. The board | substrate characterized by the above-mentioned.

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