KR100660928B1 - Organic silver ink for direct wiring - Google Patents

Abstract

The present invention relates to an organic silver composition for forming conductive wiring, an ink prepared therefrom, and a method for forming conductive wiring using the ink. More specifically, to prepare an organic silver composition through a single reaction of a salt containing silver under an organic solvent, it is applied to an inkjet printer to provide an ink capable of forming a conductive wiring. In addition, it is to provide a method for forming a conductive wiring on a variety of substrates through heat treatment after printing the prepared ink using an inkjet printer.

The organic silver composition solution of the present invention may be prepared by reacting silver-containing salts with alcohols in a alcoholic solvent with a straight or aromatic compound containing an alcohol group and a straight or aromatic compound containing an amine group, which is suitable for an inkjet printer. In order to secure the characteristics of the ink, such as liquid fluidity, an ink was prepared by adding an organic solvent, a surfactant, and the like.

 The present invention can provide a method for producing a high concentration of organic silver solution and inkjet ink at a low process cost, by heat treatment after inkjet printing, the conductive wiring having a substrate adhesion, printability and high conductivity compared to the prior art It can provide a method of forming.

Organic Silver, Ink, Conductive, Conductive Wiring, Inkjet

Description

Organic silver ink composition for conductive wiring formation. {Organic silver ink for direct wiring}

The present invention relates to an organic silver composition for forming conductive wiring, an ink prepared therefrom, and a method for forming conductive wiring using the ink. More specifically, a salt containing silver is reacted under an organic solvent such as an alcohol and an amine to prepare an organic silver composition, and to provide an ink capable of forming conductive wiring by inkjet spraying through an inkjet printer. It is to provide a method for forming a conductive wiring on a variety of substrates by printing the conductive wiring on the specific substrate by inkjet method using the ink prepared as described above, followed by heat treatment.

Conventional conductive wiring forming methods are mainly used an etching method, a screen printing method and a vacuum deposition method, and various substrates, such as glass, alumina, epoxy, polyimide, silicon wafer, etc. are used as the substrate.

The lithography method using etching includes a conductive film on a substrate, and removes unnecessary portions of the conductive film using a photolithography method to dissolve and remove portions of the conductive film with a corrosion solution, leaving only the necessary conductive wiring. How to form. This method is generally the oldest method of manufacturing PCBs, and has the advantage of obtaining relatively fine lines, but requires complicated facilities and treatment facilities such as wastewater generated during the process, and the process cost is enormous.

Screen printing is a method of forming a conductive wiring by printing a pattern on a substrate using a screen printing method on the substrate with a conductive metal paste. This method has the disadvantage that the difficulty of mask manufacturing, the number of repeated use, and the limitation of the fine line and the loss of expensive raw materials due to the inability to reuse the remaining liquid after making the conductive pattern are disadvantageous.

The vacuum deposition method is a method of forming a conductive wiring by depositing a conductive metal on a substrate having a mask by using a vacuum. This method has the advantage of obtaining sophisticated conductive wiring, but it is difficult to manufacture a mask and a large disadvantage is that the cost is high in production because a high vacuum device and a sputter are required for the actual process.

Although the above methods are widely used at present, they have problems in common, such as complicated processes, long process times, loss of raw materials, low yield, high cost, and environmental problems. In particular, lithography and screen printing methods using etching can cause serious environmental problems since the pollutants are discharged after printing, which requires enormous processing costs for treating them.

On the other hand, as electronic devices become smaller and smaller, circuits are required to be integrated and multifunctional. Recently, passive electronic components, such as resistors and capacitors mounted on a substrate, have been miniaturized or embedded in a substrate, and active PCBs with passive components that can function as passive elements have been actively studied. In this reality, the miniaturization and simplicity of the printing process is required.

As a way to solve this problem, inkjet technology has emerged in the research of electronic materials, and with the development of computers, automation, precision controllability, short-term manufacturing possibilities of various patterns, design errors and hardware during the process Ease of correction and only the desired patterns are formed by spraying ink, which minimizes raw material loss. In recent years, inkjet head technology has been applied to various fields as ink droplets have been miniaturized.In the early stages, however, technologies for making solar cell electrodes, PDP bus electrodes, and antenna wiring for RFID are being actively used in enterprise research institutes and academic or national research institutes. Research is being done. This is described in detail in a paper entitled "Paint Calvert, Inkjet Printing for Materials and Devices, Chemistry of Materials, 13, 3299, 2001".

As described above, the conductive wiring method using the inkjet technology is a method of forming conductive wiring by depositing ink droplets at an accurate position on a substrate through an inkjet head as precisely designed through a computer. The conductive wiring method using the inkjet can be paralleled with the development of computers and inkjet printers, and can be diversified in small quantities according to the needs of various consumers, and the cost can be reduced because only a minimum quantity can be used to use a desired pattern. Since there are few points and waste water generated, it has many advantages as described above in consideration of eco-friendliness. Therefore, it is possible to supply to consumers at low cost when applied to the actual electronics process. It can provide a way to lower the price of.

However, despite the advantages described above, the reason why the method of forming the conductive wiring using the inkjet is not industrially used is in the ink. In practice, conductive inks for lead wiring must have two major requirements. First, it should show excellent conductivity after sintering by outputting a line and should have good adhesion to the substrate. It is necessary to satisfy viscosity, surface tension, and stability, which are required for the second inkjet printing.

In order to satisfy the above requirements, researches have been made in various ways.

U.S. Patent No. 5,114,744 describes a method for forming a conductive circuit. The ink composition used in this method is a metal powder on the adhesive, adhered to the substrate by the adhesive according to the pattern, excess powder metal is removed, and the substrate, pattern, and metal powder are at a temperature sufficient to dissolve the metal powder (at least 600 ° C). Heating to form a circuit pattern. The present invention has a high viscosity of the adhesive that can adhere the metal powder is not suitable for the inkjet method, and the substrate should also be selected from a stable material at a high temperature because it must be treated at a high temperature.

In general, the use of a general-purpose substrate has become more important in the selection of the substrate.

For example, when applying to flexible PCBs such as polyimide and polyester, which are widely used in automation devices and cam coaters, the size of the substrate may be distorted or warped due to deformation of the base material during the firing process. This may occur, and since the physical properties required for the material change due to the decomposition of the base material or the change in the molecular structure, the heat treatment temperature cannot be increased during the manufacturing process, and thus the above method is difficult to apply.

Japanese Patent Laid-Open No. Hei 10-183207 describes an inkjet ink made of a metal ultra-fine particle independent dispersion capable of forming an electrode of a flat panel display (FPD). This method is a method of melting and evaporating a metal under high vacuum, and requires high vacuum equipment for powder production.In order to sinter the metal powder, an electron beam plasma facility and a laser induction heating device are required. There is a disadvantage, and since the dispersant added to maintain a stable metal colloidal phase at high concentration is difficult to remove at low temperatures, there is a limitation in substrate selection. In addition, the solvent that can be selected for stable dispersion is also limited, there is a problem such that the inkjet head is chemically eroded by the solvent, there is a limit to use industrially.

This is pointed out in the article "Dispersion and Stability of Silver Inks" (BY Tat, MJ Edirisinghe, Dispersion and stability of silver inks, Journal of Materials Science, 37, 4653, 2002). Reference is made to the dispersion stability of conductive inks made using three dispersants to disperse the metal powder.

Korean Patent Laid-Open Publication No. 2002-0085168 relates to a method for dispersing metal nanoparticles in the case of a mixture solution of alcohol and water, and the metal powder manufacturing method is similar to the method described in Japanese Patent Laid-Open No. 10-183207. As a vacuum evaporation method, there is a disadvantage in that the production productivity of the metal fine powder is low, and in the context of the patent, it is impossible to output by a single physical property without an additive that matches the properties of the ink, and as a result of adding an additive for ink formation, It was not stable with other additives.

In addition, many methods using metal powder particles are known, but in order to apply inkjet method, ultra-fine nanoparticles should be used to secure long-term storage stability, and low temperature decomposition is difficult to secure dispersion stability due to the chemical activity of nanoparticles. It has a common disadvantage of using polymer organics as a dispersant.

The need for long term storage stability of inkjet inks can be explained as follows. In the early stages of ink manufacture, even though particles are present in the particulate state, the particles are entangled with each other because of the chemical activity of the nanoparticles. To prevent this, dispersants should be used. It is almost impossible to remain stable permanently. Therefore, over time, the dispersant drops off a part of the particle surface, and when these particles come into contact with each other, they stick together. If this process is repeated, the particles are entangled with each other to form large particles. When it is distributed, the phenomenon of clogging the nozzle hole of the head during inkjet ejection occurs, which causes printing failure. The nozzle clogging may be initially recovered by the nozzle cleaning process, but may be permanently unrecoverable, in which case the inkjet head may need to be replaced.

As a method for overcoming the above disadvantages, a method of using an organometallic compound instead of a metal powder has also been attempted. For example, in a paper entitled "Liquid Ink Jet Printing with MOD Inks for Hybrid Microciruits, IEEE Transactions on Components, Hybrids and Manufacturing Technology, CHMT-12, 4, 1987). KF Teng et al. Have tried to form a conductive wiring by the inkjet method as a result of the metal content contained in the ink, the final film thickness after application is very thin, and thus the disadvantage that does not achieve the required level of electrical conductivity have.

In order to overcome this disadvantage, according to the Republic of Korea Patent Application No. 10-2003-0019724 invented by the present inventors, etc., an ink for forming an organic silver complex using silver oxide and forming the conductive wiring in an inkjet method is described. Ongoing research has led the inventors to react with silver-containing salts under organic solvents such as alcohols and amines to produce dissolved organic silver compositions and to invent inks that can form conductive wirings by inkjet spraying through inkjet printers. It is.

In order to overcome the above problems, in the present invention, a high amount of silver and a relatively low viscosity do not require a large amount of diluent. Accordingly, since the silver content is high, the thickness of the final film after printing becomes thick, and thus industrial fields are required to have high electrical conductivity. The present invention provides an organic silver solution for conductive wiring and a method for manufacturing the same, which are easy to apply, and in particular, the storage stability is significantly improved to prevent print defects caused by clogging of the nozzle.

 The present inventors not only overcome the shortcomings of the ultra-fine nanoparticle dispersion method as described above, but also solve the shortcomings of the low electrical conductivity due to the thin film thickness, which is a disadvantage of the organic silver complex, and the long-term storage stability is also good for the inkjet method. As a fully available organic silver has been tried a variety of methods to prepare a composition from which the present invention was made.

In general, silver salts containing most silver except silver nitrate are insoluble in water, and only a very small amount is dissolved in a single solvent, and a small amount is dissolved by an excess of ammonia reagent. have. For this reason, most of the literature uses silver nitrate as an initial material.

In the present invention, a silver-containing salt is used as an initial raw material to make an organic silver solution. When the silver salt, which is not easily dissolved in an amine alone, is stirred under an amine compound and an alcohol solvent, the silver salt is completely dissolved even with a small amount of amine. This high concentration of organic silver solution was able to be prepared, and the addition of a small amount of diluent to the inkjet method allowed the preparation of the ink.

Based on the above contents, the organic silver composition of the present invention is composed of silver-containing silver salts, amine-based compounds and alcohol groups, so that a polar or non-polar organic solvent, A conductive ink was prepared by adding a surfactant and the like.

Hereinafter, the organic of the present invention will be described in order of the composition, and the conductive ink prepared therefrom.

Initially produced organic silver composition solution is 10 to 60% by weight of silver salt containing silver, 20 to 70% by weight of amine compound having 1 to 30 carbon atoms, alcohol based compound having 1 to 30 carbon atoms alone or a mixture thereof 20 to It consists of 70% by weight and uses an alcohol-based organic solvent in the manufacturing process.

The silver salt which can be used as an initial raw material is silver nitrate, silver oxide, silver carbonate, silver lactate, silver carboxylated, etc., but silver oxide and silver carbonate were mainly used in the embodiment of the present invention.

The amine compound used in the reaction is usually a compound containing an amino group, and the linear, alicyclic, heterocyclic, aryl and aralkyl amines having 1 to 30 carbon atoms are collectively referred to as primary, secondary and tertiary amines. do. For example, ammonia, methyl amine, ethyl amine, propyl amine, isopropyl amine, butyl amine, isobutyl amine, amyl amine, hexyl amine, heptyl amine, octyl amine, 2-ethylhexyl amine, nonyl amine, decyl amine, Lauryl amine stearyl amine, oleyl amine, dibutyl amine, diamyl amine, dihexyl amine, diheptyl amine, dioctyl amine, dinonyl amine, didecyl amine, dilauryl amine, dioleyl amine, tripropyl amine , Tributyl amine, triamyl amine, trihexyl amine, triheptyl amine, trioctylamine, trinonyl amine, tridecyl amine, trilauryl amine, cyclohexylamine, pyridine, piperidine, morpholine, aniline, benzyl Amine, 1-naphthyl amine, N-methylbenzyl amine, ethylene diamine, N-dimethylbenzylamine, N-methylethylenediamine, N-propylethylenediamine, N, N-dimethylethylenediamine, N-methyl-1,3 Propanediamine, N-propyl-1,3-prop Diamines, N-isopropyl-1,3-propane diamines, diethylene triamines, N-dimethylethylene diamines, 3-methoxypropyl amines, and the like, as well as various chain lengths and structurally modified amines used for industrial purposes. Mixtures are applicable and can be selected as compounds within the range of identity that can be used by those of ordinary skill in the industry. And it may also be made of a single component or a mixture of two or more of these.

 In this case, the amine-based compound is actually exposed to the atmosphere when ink is discharged to form an image of the conductive wiring, so it is advantageous that it is not easily vaporized in the atmosphere, and it is preferable that the amine compound is easily detached during heat treatment after application to the substrate. -10-200 degreeC is suitable, Preferably it is 10-150 degreeC, More preferably, it is 40-120 degreeC. And primary amines are more preferred than secondary amines, tertiary amines.

Alcohol-based compounds to be used in the reaction include linear or linear side chains having 1 to 30 carbon atoms containing alcohol groups, alicyclic, heterocyclic, aryl and aralkyl and aromatic alcohols. All of these are collectively included, including two or more kinds thereof.

At this time, since the selection of alcohol-based compound has a great effect on the viscosity of the solution when it is actually a silver compound, this should be taken into consideration when selecting the type, and it is preferable that the boiling point is not easily evaporated at room temperature.

In the present invention, the organic silver solution is a silver salt containing silver in an appropriate amount of a single or two or more mixtures of the alcohol-based compound and a single or two or more mixtures of the amine-based compound and using an ultrasonic disperser to increase the dissolution rate. An organic silver composition solution was prepared. The present organic silver composition solution has a solid content of 20 to 40% by weight, which is considerably higher than that obtained by the prior art. Here, solid content means the weight% of silver salt contained in organic silver composition.

The organic silver composition ink was prepared by adding an organic solvent and a surfactant to a high concentration of the organic silver composition prepared by the above method, in order to secure liquid fluidity suitable for an inkjet printer.

The conductive ink composition of the present invention is 10 to 90% by weight of the organic silver composition solution, preferably 30 to 90% by weight, more preferably 50 to 80% by weight, and 9.99 to 85% by weight of the organic solvent having compatibility therewith, preferably Preferably from 9.9 to 70% by weight, more preferably from 19.5 to 50% by weight and from 0.01 to 10% by weight of a nonionic or ionic surfactant, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 5% by weight. Can be to%.

As a solvent for preparing an organic silver solution into an ink, alcohols, acetones, cellosolves, carboxylic acids, carbitols, acetates, and lactates which are generally used may be used. For example, alcohols include methanol, Ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, hexanol, heptanol, octanol, 1,3-propane diol, 1,3-hexanediol, 1,4-octane diol, etc., Acetones include acetone, methyl ethyl ketone, methyl butyl ketone, and other cellosolves such as methyl cellosolve, ethyl cellosolve, propyl cellosolve, and butyl cellosolve. Acetate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, lactate, etc. include lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate, Isobutyl lactate, 2-ethylhexyl lactate, and the like, and acetonitrile, tetrahydrofuran, cyclohexane, benzene, nitrobenzene, toluene, xylene, chloroform, and tapiene, but are not limited thereto. In addition, not only a compound within the same range that can be used by those skilled in the art can be selected, but also one selected from the group consisting of two or more mixtures can be used.

At this time, the boiling point of the solvent may be a polar solvent alone or a mixture of two or more of 50 ~ 300 ℃, preferably 150 ~ 300 ℃, more preferably 200 ~ 250 ℃.

If the boiling point of the solvent is lower than 100 ° C, the solvent may volatilize from the tip of the nozzle to the atmosphere, and clogging of the inkjet head nozzle may occur. After the formation of the conductive film and the conductive wiring, the surface may be cracked due to rapid drying in the drying process. Surface roughness may appear.

In addition, the solvent is further added to adjust the viscosity, which should be adjusted in consideration of the thickness of the coating film, the size of the inkjet head nozzle, and the like. At this time, the viscosity is preferably 2 to 100cps, preferably 2 to 50cps, more preferably 2 to 30cps.

In the case of a surfactant, it is not limited to either an ionic or nonionic surfactant, A single type or a mixture of 2 or more types can be used. It is used to adjust the wetting properties of the ink to the substrate according to the surface energy of the substrate surface, it is usually preferred to adjust the surface tension to 32 ~ 50 dyne / cm. If the surface tension of the ink liquid is lower than 32 dyne / cm, the required resolution cannot be maintained because it is sprayed on the substrate and then spreads out of the substrate too quickly. If the ink is higher than 50 dyne / cm, the amount of ink ejected from the nozzle This is not sprayed as much as necessary so that a sufficient coating film thickness cannot be obtained.

The ink composition of the above composition is excellent in storage stability than the prior art by itself, but may be further added boric acid or 2-pyrrolidone for better storage stability. .

Ink nozzles are divided into piezoelectric method using mechanical pressure and thermal bubble jet method using thermal expansion pressure. In the case of thermal bubble jet method, organic silver existing in liquid phase is directly exposed to the heating plate. Degeneration of the liquid or the formation of large lumps of silver particles can cause clogging of the nozzle.

In the present invention, a piezoelectric nozzle is used to prevent denaturation of ink and to secure liquid stability when the ink is ejected from the nozzle, and more preferably, the frequency is controlled, the temperature of the ink reservoir, the size of the nozzle is controlled, It is a good idea to use inkjet printing equipment that can control temperature.

As described above, the conductive film and the conductive wiring formed by the inkjet injection obtain final conductivity through heat treatment to evaporate the use of the organic silver as a solvent, and the preferable heat treatment temperature is 100 to 300 ° C.

More preferable heat treatment conditions include evaporation of the solvent in a stepwise manner and 3 to 20 minutes at 80 to 150 ° C. to stabilize the organic silver compound formed by evaporation of the solvent on the surface of the substrate, and finally 150 to decompose and silver the organic silver compound. Good film properties can be obtained by treating it for 5 to 20 minutes at ~ 300 ℃. In addition, when not only an atmospheric atmosphere but also a single or mixed gas such as nitrogen, argon, hydrogen, and the like are mixed as the atmosphere during heat treatment, decomposition of organic silver, film properties, adhesion to substrates, and conductivity properties can be improved.

In the present invention, the conductivity of the conductive wiring prepared as described above is about 2 × 10 ⁻⁵ Ω˙cm to 8 × 10 ⁻⁶ Ω˙cm, which is excellent in conductivity and suitable as a conductive wire.

The present invention is described below in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited by the following examples. "%" Means% by weight unless otherwise specified.

Example

Example 1

Preparation of Organo Silver Composition (A)

23% silver oxide and 51% methanol are added to a round bottom flask equipped with a condenser, and ultrasonic dispersion and stirring are maintained at 10 to 25 ° C. 26% of isopropylamine was added dropwise to this solution and concentrated by distillation under reduced pressure at 30 ° C to prepare an organic silver composition having a solid content of 30%.

The addition of isopropylamine initiates the dissolution reaction of silver salts, initially black and finally a clear and clear solution.

Example 2

Preparation of Organo Silver Composition (B)

In Example 1, silver oxide was replaced with 23% silver carbonate, and the organic silver composition having a solid content of 31% was prepared under the same conditions as in Example 1.

Example 3

Preparation of Organo Silver Composition (C)

In Example 1, silver oxide was replaced with 23% silver nitrate, and the organic silver composition having a solid content of 30% was prepared under the same conditions as in Example 1.

Example 4

Preparation of Organo Silver Composition (D)

In Example 1, methanol was replaced with 51% of 2-butanol, and the organic silver composition having a solid content of 28% was prepared under the same conditions as in Example 1.

Example 5

Preparation of Organo Silver Composition (F)

In Example 1, isopropylamine was replaced with 26% of N-butylamine, and the organic silver composition having a solid content of 27% was prepared under the same conditions as in Example 1.

As shown in Examples 1 to 5, it was possible to prepare an organic silver composition having a significantly higher solid content than the conventional organic silver composition.

The organic silver composition can be easily mass-produced at a low cost by a simple process, and can be concentrated to a higher solid content than the composition of the prior art, and thus, various applications of an electroless solution, a screen printing ink, etc. can be considered. In addition, it is quite stable in long-term storage, so that the weakness of precipitation in long-term storage such as nanoparticles can be compensated.

Example 6

Preparation of Ink Composition (A)

In the organic silver composition prepared in Example 1, 4.7% butyric acid and 32.23% methanol were added to 63% of the composition, followed by stirring and adding 0.07% of sulfinol 465 (trade name; manufactured by Airproduces) as a surfactant to prepare an ink composition (A). It was. At this time, the solid content was 19%, the surface tension was 30 dyne / cm, the viscosity was 4.5 cps.

Example 7

Preparation of Ink Composition (B)

The organic composition prepared in Example 2 was added with 7.66% of isopropyl lactate and 31.27% of ethyl cellosolve to 61% of the composition, followed by stirring and adding 0.07% of sulfinol 465 to prepare an ink composition (B). At this time, the solid content was 19%, the surface tension was 33 dyne / cm, the viscosity was 4.3cps.

Example 8

Preparation of Ink Composition (C)

The organic composition prepared in Example 1 was added 36.93% of ethyl cellosolve to 63% of the composition, and then 0.07% of sulfinol 465 was added and stirred to prepare an ink composition (C). At this time, the solid content was 19%, the surface tension was 31 dyne / cm, viscosity was 3.8cps.

Example 9

Preparation of Ink Composition (D)

The organic composition prepared in Example 2 was added 38.93% butylcarbitol to 61% of the composition, and then 0.07% of sulfinol 465, a surfactant, was added and stirred to prepare an ink composition (D). At this time, the solid content was 19%, the surface tension was 32 dyne / cm, the viscosity was 4.3cps.

Example 10-13

Conductive wiring

The ink prepared in Examples 7 to 10 was filled into a polyethylene container, and a borosilicate (base material 1) and polyimide, which were ordinary glass, were used in a flatbed printer equipped with a piezo inkjet printer head F083000 (trade name; manufactured by Epson). Films (trade name: Shimton, manufactured by DuPont) (Substrate 2) were each printed three times, each having a line width of 100 μm, a length of 50 mm, a width of 10 mm, and a length of 10 mm, and subjected to heat treatment to form a final conductive wiring. The heat treatment temperature conditions at this time was treated for 10 minutes at 100 ℃ and then continuously treated for 20 minutes at 250 ℃, the characteristics thereof after treatment is shown in Table 1 below.

Ink used Silver film adhesion after firing ⁽¹⁾ Pattern Line Printability ⁽²⁾ Electrical Conductivity ⁽³⁾ Equipment 1 Equipment 2 Equipment 1 Equipment 2 Equipment 1 Equipment 2 Example 10 Example 6 Good Good usually usually 1.8 × 10 ^-5 Ω˙cm 1.2 × 10 ^-5 cm Example 11 Example 7 Good Good Good Good 8.2 × 10 ^-6 cm 7.9 × 10 ^-6 Ω˙cm Example 12 Example 8 Good Good Good Good 9.3 × 10 ^-6 Ω˙cm 8.1 × 10 ^-6 cm Example 13 Example 9 usually Good Good Good 2.4 × 10 ^-5 Ω˙cm 1.8 × 10 ^-5 Ω˙cm

(1) Adhesion evaluation: The state where the silver film is transferred to the adhesive surface is evaluated by attaching a Scotch tape (trade name: 3M Corporation) to the printing surface and peeling it off.

Good: No transfer on the adhesive side of the tape

Normal: When a small amount of silver film is transferred to the adhesive side of the tape and separated from the base

Poor: When most of the silver film is transferred to the adhesive side of the tape and separated from the base

(2) Printability evaluation: Observe and evaluate the surface bleeding after drying for 10 minutes

Good: If there is no problem on the printed surface and the shape of lines is clear

Normal: Partial application or small drops on the print surface

Poor: The application surface is heavily pushed to one side of the print surface and there is a break in the line.

(3) Electrical conductivity evaluation: Measure the electrical resistance by the two-terminal method and calculate from the width, length, and thickness of the silver film. (The thickness of the silver film is calculated from the photograph of the cross section by electron scanning microscope.

Conductivity = 1 / (resistance),

Specific resistance = (electrical resistance) X [(film thickness) X (film width)] / (film length)

As described above, the conventional nanoparticles are surrounded by a material such as a polymer for stabilizing the surface of the particles in the form of a polymer that is difficult to decompose when the conductivity is measured by printing and heat treatment to obtain conductive wiring. While it is difficult to obtain a close conductivity, the organic silver ink of the present invention has the advantage of obtaining high conductivity because the monomolecular organic substance which contributed to stabilization of silver ions during heat treatment evaporates to vapor and only pure silver ions form a solid silver film. Is there.

The above method is excellent in long-term storage stability, so it is not only industrially easy to use, but also organic silver concentrate having a relatively high absolute content of silver can be obtained, and the silver content is relatively high even in a diluent that can be discharged with an inkjet nozzle. Since the electrical conductivity of the finally obtained silver film is relatively high even at the same number of repeated prints, it is possible to produce an organic silver ink that can be applied to various industrial applications.

  In addition, by using the ink composition, it is possible to provide a conductive film or conductive wiring forming technology having excellent electrical conductivity using an inkjet printing method.

Claims (17)

delete delete delete delete delete In the organic silver composition, 10 to 90% by weight of an organic silver composition comprising at least one compound selected from silver salts containing silver, at least one compound selected from amine compounds, at least one compound selected from alcohol compounds, 9.99 to 85% by weight of an organic solvent selected from one or more of cellosolve compounds, carbitol compounds, acetate compounds or lactate compounds, 0.01 to 10 wt% surfactant; Organic silver ink composition comprising a. delete delete delete The organic silver ink composition according to claim 6, wherein the silver salt is one or more selected from among silver oxide, silver carbonate, silver nitrate, silver carboxylate, and silver lactate, and is used alone or in combination. According to claim 6, The amine-based compound is selected from one or more selected from linear amine, alicyclic amine, heterocyclic amine, aryl amine or aralkyl amine having 1 to 30 carbon atoms, used alone or in combination An organic silver ink composition. The alcohol-based compound according to claim 6, wherein the alcohol-based compound has at least one selected from linear alcohols having 1 to 30 carbon atoms, alcohols containing side chains on linear chains, alicyclic alcohols, heterocyclic alcohols, aryl alcohols, and aralkyl alcohols. Organic silver ink composition, characterized in that used alone or mixed. The organic silver ink composition according to claim 6, wherein the organic silver composition is composed of 10 to 60% by weight of silver salt, 20 to 70% by weight of an amine compound, and 20 to 70% by weight of an alcohol compound. 7. The organic silver ink composition according to claim 6, wherein the cellosolve compound is selected from methyl cellosolve, ethyl cellosolve, propyl cellosolve, and butyl cellosolve. 7. The organic silver ink composition according to claim 6, wherein the carbitol compound is selected from ethyl carbitol, propyl carbitol and butyl carbitol. 7. The organic silver ink composition according to claim 6, wherein the acetate compound is selected from ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate. The organic silver ink composition according to claim 6, wherein the lactate compound is selected from lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate, isobutyl lactate, 2-ethylhexyl lactate. .