KR100351230B1 - Conductive paste composition for electrodes - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paste for electrodes, comprising 100 parts by weight of conductive powder in an average particle diameter of 0.8 to 4 μm, 3 to 30 parts by weight of conductive fine particles in an average particle diameter of 0.02 to 0.1 μm, and glass frit 0 to 10. The electrically conductive paste composition of this invention containing a weight part and 3-30 weight part of organic vehicles can provide the microelectrode pattern which is calcinable at low temperature, is good adhesiveness with respect to a base material, and is low resistance.

Description

Conductive paste composition for electrodes {CONDUCTIVE PASTE COMPOSITION FOR ELECTRODES}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive paste composition for electrodes, and more particularly, to a conductor circuit on various electronic devices such as electrode formation of a display substrate, ceramic substrate, thermal head, or integrated circuit. It relates to a conductive paste composition used to form a.

In recent years, there has been an increasing demand for low-temperature firing of conductor circuit patterns, low resistance of conductors, high refinement and high density in displays and circuit boards, and is a light and thin type as an image display device replacing heavy CRTs. Flat display was developed. Liquid crystal displays (LCDs) are being actively developed as flat panel displays, which have problems of dark images and narrow viewing angles.

As an alternative to the liquid crystal display, there is an image display device using a plasma display panel (hereinafter referred to as PDP) or an electron-emitting device that is a self-emitting discharge type display. In addition, the demand is increasing because the viewing angle is wide and the screen meets the demand for large screen and high resolution.

The electron emitting device has a field emission type (FED) represented by a cold cathode electron emitting device, and an image forming apparatus using a cold cathode electron source emits fluorescence by irradiating an electron beam emitted from the electron emitting device to a phosphor. To display an image. In this apparatus, the front glass substrate and the back glass substrate are provided with functions, respectively, and the back glass substrate is designed with matrix wirings for connecting a plurality of electron-emitting devices and electrodes of those devices. Since these wirings intersect at the electrode portion of the electron-emitting device, a dielectric layer for insulating is designed. In addition, a spacer is formed between the substrates as an internal air pressure supporting member.

PDPs are capable of high-speed display and large-sized displays compared to liquid crystal displays, and thus, demand for OA devices and information display devices is increasing. Regarding the PDP, an AC type gas display panel is shown in FIG. As shown in Fig. 1, the PDP has a structure in which a pair of electrodes regularly aligned are placed on two opposing glass substrates, and an inert gas such as neon, helium, and xenon is enclosed between the two substrates. Each cell is made to emit light by displaying a voltage by applying a voltage between the cells and discharging the cells in a small cell around the electrode. On the other hand, the both substrates are composed of a display side substrate 1 (hereinafter referred to as a front substrate) and a back side substrate 2 made of a transparent material such as glass. In general, a discharge holding electrode pair composed of a transparent electrode 3 and a bus electrode 4 and extending in a lateral direction and parallel to each other is disposed on the front substrate. They are covered with a transparent dielectric layer 5, furthermore a transparent protective layer 6. Similarly, a plurality of address electrodes 8 orthogonal to the discharge sustaining electrode pair are located on the back side substrate covered with the dielectric layer 7. The discharge cells are pixelated by the partition wall 9 at the intersections of the discharge sustaining electrode pairs with the address electrodes 8, or in the vicinity thereof, to selectively discharge these discharge cells to emit the phosphors 10. Display is performed.

In the above-described PDP, the electrodes of the front plate and the back plate are formed of, for example, silver paste. In the conventional silver paste, silver powder having an average particle diameter of 1 to 4 µm is used alone. However, in this case, when firing at a low temperature of 400 to 500 ° C., a dense film is not obtained, thereby causing a problem that the resistance of the conductor is also high, and it is difficult to form sharp edges. The reason for this is presumably because the distribution of the particle size of the conductive powder used for the conductive paste is not optimized and the particle size is large, so that when firing at a low temperature, the sintering is not performed and the roughening increases, thereby increasing the pin hole.

It is therefore an object of the present invention to provide a conductive paste composition that is very suitable for providing thin film electrode patterns on ceramic and glass substrates that can be baked at low temperatures and have high adhesion strength to the substrate and low resistance.

1 is a perspective view showing the basic structure of a typical gas discharge display panel.

In order to achieve the above object, in one embodiment of the present invention, 100 parts by weight of conductive powder having an average particle size of 0.8 to 4 μm, 3 to 30 parts by weight of conductive fine particles having an average particle diameter of 0.02 to 0.1 μm, 0 to 10 parts by weight of glass frit, and organic Provided is a conductive paste composition for electrodes (“generic conductive paste”) comprising 3 to 30 parts by weight of a vehicle.

This invention also provides the photosensitive electrically conductive paste composition ("photosensitive electrically conductive paste") for electrodes which contains the photosensitive organic component as an organic vehicle component in the said normal electrically conductive paste.

The electrically conductive paste composition of this invention contains electroconductive fine particles other than a normal electrically conductive powder.

This invention is demonstrated concretely below.

(1) conductive powder

The electroconductive powder used for the electrically conductive paste of this invention is a powder containing 1 or more types chosen from the group which consists of Ag, Cu, Au, Pd, Ni, and Pt. The shape of these powders may be spherical, plate-like, blocky, rod-like, or the like, and spherical powders having low cohesiveness and good dispersibility may be preferably used.

The average particle diameter of the conductive powder is in the range of 0.8 to 4 μm, preferably in the range of 1 to 3 μm. If the particle size is less than 0.8 µm outside of this range, the particles become too fine to increase the shrinkage rate during sintering and easily cause cracks in the film, the particles are agglomerated, it is difficult to obtain a stable dispersion state in the paste, and the printing characteristics are deteriorated. . In addition, when the particle diameter is larger than 4 µm, the surface of the paste coating film becomes rough, it is difficult to obtain a very fine pattern, and the sintering property is lowered, which makes it difficult to obtain a dense thin film, which is not preferable.

In the case of the photosensitive conductive paste, the shape of the conductive powder is preferably spherical and particulate in order to improve the light transmittance at the time of exposure and the dispersibility of the conductive paste, and when the average particle diameter is less than 0.8 µm, the particles are too fine and are exposed at the time of exposure. It is difficult to obtain a predetermined resolution due to light scattering, and when it exceeds 4 µm, edge breakage of the electrode pattern is deteriorated, and the smoothness of the conductor surface is lowered.

The surface area / weight ratio (specific surface area) of the conductive powder used in the present invention is preferably 0.5 to 3.5 m ² / g and the density is in the range of 2.5 to 6 g / cm ³ . If the specific surface area is less than 0.5 m ² / g, the particles become too large and the smoothness of the coated film after firing decreases, which is not preferable. If the specific surface area is larger than 3.5 m ² / g, the particles become too fine, the particles tend to aggregate and the printing characteristics are degraded. If the density is out of the above range, the printing characteristics are poor, which is not preferable. In the case of the photosensitive conductive paste, when the specific surface area of the conductive powder falls within the above-mentioned range, light transmission at the time of exposure is performed smoothly to the lower side, whereby cutting of the electrode pattern edge is good and a rectangular electrode cross-sectional shape is obtained. .

(2) conductive fine particles

The conductive fine particles used in the conductive paste of the present invention may be one or more fine particles selected from the group consisting of Ag, Cu, Au, Pd, Ni, and Pt similarly to the conductive powder.

The average particle size of the conductive fine particles is preferably in the range of 0.02 to 0.1 μm, but if the particle size is less than 0.02 μm, the particle size is too fine, the activity of the conductive fine particles becomes large, causing aggregation and uneven dispersion in the paste. It is not preferable because the secondary particles may grow into secondary particles and the film after sintering may be stained. Moreover, when the particle diameter of electroconductive fine particles exceeds 0.1 micrometer, the effect of low temperature sintering decreases and a dense conductor film is not obtained, which is not preferable. In the case of the photosensitive conductive paste, when the particle diameter of the conductive fine particles is smaller than 0.02 μm, light is scattered at the time of exposure, and a predetermined resolution is not obtained. When the photosensitive conductive paste exceeds 0.1 μm, scattering is affected when dimming, resulting in an extremely fine pattern. This is difficult to obtain.

The average particle diameter of electroconductive fine particles can be measured from the particle size analysis measuring apparatus by a laser diffraction method, or the photograph of the metal fine particle image | photographed by TEM (transmission electron microscope). In the case of TEM, the primary particle diameter of 100 metal fine particles selected at random is measured, and let the primary particle diameter of the other microparticles | fine-particles except five particle from a large side and five particle from a small side be used as a measurement of an average particle diameter.

The specific surface area of the conductive fine particles is in the range of 2 to 50 m ² / g, preferably in the range of 3 to 40 m ² / g, and when the conductive fine particles having a specific surface area in this range are used, A sintering promoting effect, a dense film is obtained, the electrical resistance value is lowered, and a coated film with good precision is obtained. Since the particle shape of the said electroconductive fine particle is spherical, there is little cohesiveness, and it is preferable.

The conductive fine particles are used in an amount of 3 to 30 parts by weight, preferably 5 to 20 parts by weight based on 100 parts by weight of the conductive powder. If the amount of the conductive particles is less than 3 parts by weight, the low-temperature baking effect and the densification effect of the conductor film are used. When the amount is more than 30 parts by weight, the conductive fine particles are excessively agglomerated and the printing characteristics are deteriorated, so that the surface smoothness and film staining of the film are likely to occur, and the plastic shrinkage is large, making it difficult to obtain a high density pattern. In the case of the photosensitive conductive paste, when the conductive fine particles are used at less than 3 parts by weight, low-temperature baking is not sufficient, and when the conductive particles are more than 30 parts by weight, light is scattered by the conductive fine particles during exposure, making it difficult to form an extremely fine pattern. Because it is not desirable.

(3) glass frit

The conductive paste composition of the present invention may optionally contain a glass frit. The glass frit serves as an adhesive that bonds the conductive powder and the conductive fine particles to each other. The glass frit improves the adhesion of the conductive paste to the ceramic or the glass substrate and softens during sintering to aggregate the glass frit to the substrate side. .

It is preferable that the glass frit is not used when the paste composition is used for the internal electrode of the ceramic multilayer substrate, and when the paste composition is used to form the surface electrode of the display substrate or the ceramic substrate, 100 parts by weight of the conductive powder is used. It is used in an amount of 10 parts by weight or less.

As the glass frit, glass frit A and glass frit B can be preferably used. As the glass frit A, it is possible to use bismuth oxide (Bi ₂ O ₃ ), and it is preferable that the composition component and content indicated in the oxide conversion notation contain 90 wt% or more of the composition as shown in Table 1 below, and the glass frit B The containing containing lead oxide (PbO) is used, It is preferable that the composition component and content which are represented by the oxide conversion notation contain 90 weight% or more of a composition as Table 2 below.

Component Content (% by weight) Bi ₂ O ₃ 40 to 90 SiO ₂ 5 to 30 B ₂ O ₃ 5 to 30 BaO 2 to 40

Component Content (% by weight) PbO 40 to 90 SiO ₂ 10 to 40 B ₂ O ₃ 5 to 30 ZnO 0 to 10 Al ₂ O ₃ 0 to 20

By use of the said glass frit, it becomes possible to bake waste yeast at the temperature from which a glass substrate is not stressed.

In the glass frit A composition, when bismuth oxide (Bi ₂ O ₃ ) is used in less than 40% by weight, there is little effect of increasing the adhesive strength when the conductive paste is baked on the glass substrate, and when it exceeds 90% by weight, glass frit It is not preferable because the softening point of is so low that the de-vehicle property of the conductive paste is deteriorated and the adhesive strength with the substrate is lowered. The preferred amount of bismuth oxide is in the range of 50 to 80% by weight.

When the silicon oxide (SiO ₂ ) is less than 5% by weight in the glass frit A composition, the stability of the glass frit is lowered, and when it is more than 30% by weight, the heat resistance temperature rises and it is difficult to be baked on the glass substrate at 570 ° C. or lower. It becomes difficult. Preferably, silicon oxide is used in amounts ranging from 5 to 15% by weight.

In the glass frit A composition, boron oxide (B ₂ O ₃ ) is added to control the baking temperature on the glass substrate so as not to impair the properties of adhesive strength, thermal expansion coefficient and the like. When it exceeds 30 weight%, the stability of a glass frit will fall. Boron oxide is preferably used in an amount in the range of 7 to 20% by weight.

In the glass frit A composition, when the barium oxide (BaO) is used at less than 2% by weight, it is difficult to control the glass baking temperature, and when it exceeds 40% by weight, the stability of the glass layer is lowered. Preferably in an amount in the range from 2 to 30% by weight.

In addition, if the lead oxide (PbO) is less than 40% by weight in the glass frit B composition, the effect of increasing the adhesive strength when baking the conductive paste on the glass substrate is small, and when it exceeds 90% by weight, the softening point of the glass frit is too low. It is not preferable because the vehicle performance of the conductive paste is deteriorated and the adhesive strength with the substrate is lowered. The preferred amount of lead oxide is in the range of 50 to 80% by weight.

When the silicon oxide (SiO ₂ ) is less than 10% by weight in the glass frit B composition, the stability of the glass frit is lowered, and when it is more than 40% by weight, the heat resistance temperature rises and it is difficult to be baked on the glass substrate at 570 ° C. or less. It becomes difficult. Preferably, silicon oxide is used in amounts ranging from 10 to 30% by weight.

When boron oxide (B ₂ O ₃ ) is used in less than 5% by weight in the glass frit B composition, the adhesive strength is lowered, and when used in excess of 30% by weight, the stability of the glass frit is lowered. Boron oxide is preferably used in amounts ranging from 5 to 20% by weight.

When zinc oxide (ZnO) is used in excess of 10% by weight in the glass frit B composition, the stability of the glass layer is lowered, and the preferred amount of use is in the range of 2 to 5% by weight.

In the glass frit B composition, aluminum oxide (Al ₂ O ₃ ) is added to increase the deformation temperature of the composition and to stabilize the glass composition or the conductive paste, and if it exceeds 20% by weight, the heat-resistant temperature of the glass becomes too high to form a glass substrate. It becomes difficult to call Preferred amounts of use range from 2 to 15% by weight.

In addition, according to the present invention, a composite glass frit containing both the glass frit A and the glass frit B may be used as the glass frit, and the components and contents expressed in the oxide conversion notation may be 90 It is preferable to contain by weight or more.

Component Content (% by weight) Bi ₂ O ₃ 40 to 90 PbO 40 to 90 SiO ₂ 5 to 30 B ₂ O ₃ 5 to 30 BaO 2 to 40 ZnO 0 to 10 Al ₂ O ₃ 0 to 20

It is preferable that the said glass frit A, the glass frit B, and the composite glass frit are 0.3-2 micrometers of average particle diameters, and 4 micrometers or less of the largest sizes. More preferably, the average particle diameter is in the range of 0.3 to 1 m, and the maximum size is 3 m or less. When the particle diameter of the glass frit is in the above range, the adhesion strength with the glass substrate at low temperature can be increased, and a dense film of low resistance can be obtained, and even when the thin film is formed, there is an advantage that the peeling of the thin film is unlikely to occur.

The softening point of the glass frit A and the glass frit B is measured by a differential thermal (DSP) method, and the softening point is preferably in the range of 360 to 520 ° C, more preferably in the range of 370 to 460 ° C. If the softening point is lower than 360 ° C., organic components are likely to be contained, and blisters are likely to occur in the coating film of the paste as organic components such as polymers are decomposed. On the other hand, when the softening point is higher than 520 ° C., the adhesive strength to the substrate of the film after firing is lowered.

When glass frit is used for surface electrode formation, it is preferable to be used for the photosensitive electrically conductive paste in the quantity of 1-8 weight part. If the amount of the glass frit is less than 1 part by weight, the conductor film is not sufficiently tightly adhered to the substrate. If the amount of the glass frit is more than 8 parts by weight, the conductive film is scattered during exposure to cause deviation, resulting in an undesirable edge shape of the electrode pattern.

(4) organic vehicle

Organic vehicle components usable in the general conductive paste of the present invention include cellulose derivatives such as ethyl cellulose, methyl cellulose, nitro cellulose and carboxymethyl cellulose, and resins such as acrylic acid esters, methacrylic acid esters, polyvinyl alcohols, and polyvinyl butyral. Ingredients may be used. Among them, acrylic resins and ethyl cellulose can be preferably used in view of the dispersibility of the conductive powder and the conductive fine particles, the coating properties of the paste, and the de-vehicle (degradability) during firing. These resin components are dissolved and used in an organic solvent.

The organic vehicle component, in the paste composition of the present invention, is used in an amount of 3 to 30 parts by weight based on 100 parts by weight of the conductive powder, and if it is not in this range, it cannot be completely evaporated (sintered, de-vehicle) in the firing step. This is undesirable.

(5) photosensitive organic components

The photosensitive organic component used in the photosensitive conductive paste of the present invention is used in an amount of 8 to 30 parts by weight based on 100 parts by weight of the conductive powder. When the amount of the photosensitive organic component used is less than 8 parts by weight, photocuring at the time of exposure is performed at the bottom of the conductor layer. There is a problem that it is difficult to form a predetermined ultrafine pattern until the cross section of the conductor film is poor, and developability is deteriorated. In addition, when the photosensitive organic component exceeds 30 parts by weight, the organic component removed by firing increases, resulting in poor electrode density, high resistance, and electrode disconnection, which is not preferable.

The photosensitive organic component is composed of a photosensitive resin and a photopolymerization initiator. The photosensitive resin may be either a negative type or a posi type, and the negative type is preferably used because it is easy to handle and easy to design. Can be. Examples of the photosensitive resin include linear or branched reactive polymers, monomers and oligomers having photosensitive groups such as acryloyl groups in the molecular structure and forming insoluble polymers by exposure.

Examples of the linear or branched reactive polymer include (meth) in the side chain of the polymer or copolymer of (meth) acrylic acid and / or its ester, or the copolymer of these monomers with a styrene-based compound and / or acrylonitrile. Acrylics such as polymers modified to have acrylic acid groups; Polyesters such as (meth) acrylates of unsaturated polyesters, polyesters and polyester polyols; Polyether (meth) acrylates such as polyethylene glycol (meth) acrylate and polypropylene glycol (meth) acrylate; Epoxy diacrylate type | system | group obtained by reaction of bisphenol-type epoxy resin, novolak-type epoxy resin, or alicyclic epoxy resin and acrylic acid; Urethane (meth) acrylate type | system | group obtained by reaction of a polyether polyol or polyester polyol, diisocyanate, and a hydroxyl-group containing (meth) acrylate; And polymers such as polyimide-based compounds such as a copolymer of biphenyltetracarboxylic anhydride and 2- (meth) acrylamide-diaminodiphenyl ether.

The polymer has a molecular weight of less than 50,000, preferably less than 30,000, and by adjusting in this range, printing properties or pattern formability can be improved.

As the monomer or oligomer, in addition to the oligomer having a low polymerization degree of the polymer, triethylene glycol acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol Or acrylic esters such as tetra-acrylate, dipentaerythritol hexaacrylate; Monomers such as epoxy resins such as bisphenol A-di (meth) acrylate.

Photoinitiators used in the photosensitive organic component of the present invention include radical photoinitiators that generate free radicals when exposed to active light such as ultraviolet light, for example 1-hydroxycyclohexylphenylketone, 2-hydroxy-2. Acetophenones such as -methyl-1-phenylpropan-1-one; Benzophenones such as benzophenone and 3,3'-dimethyl-4-methoxybenzophenone; Thioxanthones, such as thioxanthone and diethyl thioxanthone, can be used. These photoinitiators can be used individually or in mixture of 2 or more types, or in combination with photoinitiators, such as amines.

(6) organic solvent

In addition, an organic solvent may be added to the conductive paste composition of the present invention to adjust the viscosity by dissolving the organic components and dispersing the conductive powder, the conductive fine particles and the glass frit. Organic solvents include texanol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), ethylene glycol (terpene), butyl carbitol, ethyl cellosolve, ethylbenzene, isopropylbenzene Methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, dimethyl sulfoxide, α- or β-terepineol, fine oil, polyvinyl butyral, 3-methoxybutyl acetate, γ-butyrolactone, diethylphthalate and the like. These organic solvents can be used individually or in mixture of 2 or more types.

(7) other additives

In addition, the conductive paste composition of the present invention, in addition to the components described above, in order to impart stability during storage, a polymerization inhibitor such as hydroquinone monomethyl ether; Dispersants such as polyacrylates, cellulose derivatives; Adhesion imparting agents such as a silane coupling agent for improving the adhesion to a substrate; Antifoaming agent to improve coating performance; Plasticizers for improving workability; Additives such as thixotropic imparting agents may be included.

(8) kneading and forming electrodes

The conductive paste composition of the present invention is kneaded with the above components using a kneader such as a roll mill having three rolls, a mixer, a homogenizer and the like. In addition, in order to impart fluidity suitable for application, the viscosity of the conductive paste composition is usually in the range of 10,000 to 150,000 centipoise, preferably in the range of 30,000 to 100,000 centipoise. The viscosity of the coating liquid at the time of printing can be adjusted normally in the range of 10,000-70,000 centipoise, preferably in the range of 20,000-50,000 centipoise.

The general conductive paste of the present invention may form a desired electrode pattern on a substrate such as a glass substrate or a ceramic substrate by a screen printing method, and after drying, bake at a low temperature in the range of 430 to 550 ° C. for 15 to 30 minutes to form an electrode. have.

The photosensitive conductive paste containing the photosensitive organic component can easily form a large area ultra fine conductor circuit pattern by a so-called photolithography method as follows. Specifically, a photosensitive conductive layer is formed on a glass or ceramic substrate by coating or transferring the photosensitive paste composition by a known method such as a screen printing method, a bar coater, a roll coater method, or the like, and usually in an oven. After drying to remove the organic solvent, it is covered with a predetermined photomask, and then patterned portions are exposed to active light sources such as ultraviolet rays, infrared rays, and ion beams and photocured. At this time, the active light source is preferably ultraviolet light because it can be easily irradiated with a relatively simple device. The uncured portion is developed and removed with a developer, and then washed to form a pattern. The developing process may be carried out at a temperature in the range of 20 to 50 ° C. by using an aqueous alkali solution having a concentration in the range of 0.1 to 1.0% by weight as a developer by spraying, dipping, or the like. As the aqueous alkali solution, an inorganic alkali aqueous solution such as an aqueous sodium carbonate solution, an organic alkali aqueous solution such as mono ethanolamine, diethanolamine, or the like can be used, and it is preferable to use an aqueous organic alkali solution because it is easy to remove the alkaline component during firing. . In this manner, the film on which the pattern is formed may be baked on a glass substrate at a temperature in the range of 430 to 550 ° C. for 15 to 30 minutes to form an electrode.

In the photosensitive conductive paste of the present invention, the ultraviolet rays sufficiently reach the lower part at the time of exposure and can form a good pattern without edge curl after the development, and a film having high adhesion to the substrate after firing is obtained.

The present invention will be described in more detail with reference to the following Examples, which are not intended to limit the present invention. In addition, the concentration% is% by weight unless otherwise noted.

Example 1

86 parts by weight of Ag powder with an average particle diameter of 2.3 μm, specific surface area of 0.74 m ² / g and density of 3.9 g / cm ³ , 10 parts by weight of Ag fine particles with an average particle diameter of 0.06 μm and a specific surface area of 9.5 m ² / g, and glass frit A 4 weight 92 parts by weight of the powdered solid content and 8 parts by weight of ethyl cellulose were added to terebinol as an organic solvent to adjust the viscosity, followed by kneading with a triaxial roll to prepare a conductive paste composition according to the present invention. In this case, the glass frit A was composed of 68.9 wt% Bi ₂ O ₃ , 10.0 wt% SiO ₂ , 11.8 wt% B ₂ O ₃ , 6.5 wt% BaO and 2.8 wt% Al ₂ O ₃ , with an average particle diameter of 1.0 μm. It had a maximum size of 3.6 μm, a softening point of 460 ° C., and a thermal expansion coefficient of 90 × 10 ⁻⁷ / K.

The electrically conductive paste obtained as mentioned above was apply | coated to the soda glass substrate of 25 cm x 25 cm size by the screen printing method, and the coating film was formed. The thickness after drying a coating film at 80 degreeC for 30 minutes was 6 micrometers. It baked at the speed | rate of 250 degreeC / hour, hold | maintained at the maximum temperature of 480 degreeC for 15 minutes, and baked.

The obtained electrically conductive film was a defect-free uniform film whose thickness is 3.1 micrometers and whose specific resistance is 2.2 microPa * cm, and the electrically conductive film which has low resistance by low temperature baking was obtained. In addition, the conductive film was firmly adhered to the substrate without the peeling phenomenon.

Example 2

Except for using the Ag particles in Example 1 having an average particle diameter of 0.03 ㎛ and a specific surface area of 3.0 m ² / g in the same manner to prepare a conductive paste composition of the present invention.

By using the above conductive paste, a solid and uniform conductive film having a thickness of 3.3 mu m and a specific resistance of 2.5 mu Pa · cm was obtained.

Example 3

In Example 1, Ag particles were used having an average particle diameter of 0.05 μm and a specific surface area of 3.7 m ² / g, and as a glass frit, 73 wt% PbO, 14 wt% SiO ₂ , 7 wt% B ₂ O ₃ , and ZnO 3 wt% Organic solvent using glass frit B composed of% and Al ₂ O ₃ 3% by weight, average particle diameter of 1.1 μm, maximum size of 3.8 μm, softening point of 435 ° C., and coefficient of thermal expansion of 80 × 10 ⁻⁷ / K The conductive paste composition of the present invention was prepared in the same manner except that polyvinyl butyral was used.

Using the said electrically conductive paste, the firm and uniform electrically conductive film of thickness 3.5micrometer and specific resistance 2.6 microPa * cm was obtained.

Example 4

In Example 1, as the Ag powder, a spherical powder having an average particle diameter of 1.6 μm, a specific surface area of 0.78 m ² / g, and a density of 3.9 g / cm ³ was used, and Ag / Pd (average particle diameter of 0.03 μm, specific surface area of 15 m) was used as conductive fine particles. ² / g) using a mixed powder in a 95/5 weight ratio, 78% by weight Bi ₂ O ₃ , 11% by weight PbO, 3.5% by weight SiO _2, 3.5% by weight B ₂ O ₃ , 2.5% by weight BaO and The same except for using a composite glass frit composed of 1.5 wt% Al ₂ O ₃ , having an average particle diameter of 1.0 μm, a maximum size of 3.6 μm, a softening point of 380 ° C., and a thermal expansion coefficient of 82 × 10 ⁻⁷ / K. The conductive paste composition of the present invention was prepared.

After coating, the mixture was kept at 530 ° C for 15 minutes and fired to obtain a firm and uniform film having a thickness of 3.7 µm and a resistivity of 6.0 µPa · cm.

Example 5

Except for using the mixed powder of Ag / Pd (average particle diameter 1.9 ㎛, specific surface area 4.3 m ² / g and density 3.9 g / cm ³ ) 99.5 / 0.5 weight ratio as the conductive powder in Example 3 The electrically conductive paste composition of this invention was produced.

After coating, the mixture was kept at 520 ° C for 15 minutes and fired to obtain a firm and uniform film having a thickness of 3.7 µm and a resistivity of 3.5 µΩ · cm.

Example 6

Except for using a mixed powder of Ag / Pd (average particle size 3.3 ㎛, specific surface area 1.9 m ² / g and density 4.3 g / cm ³ ) 95/5 weight ratio as the conductive powder in Example 3 The electrically conductive paste composition of this invention was produced.

After coating, the mixture was kept at 530 ° C. for 15 minutes and fired to obtain a firm and uniform film having a thickness of 3.7 μm and a resistivity of 4.5 μm · cm.

Example 7

In Example 1, Ni powder having an average particle diameter of 3.2 μm, a specific surface area of 0.52 m ² / g, and a density of 4.6 g / cm ³ was used as the conductive powder, and Ni particles having an average particle diameter of 0.03 μm and a specific surface area of 12 m ² / g were used. The conductive paste composition of the present invention was prepared in the same manner except that glass frit B (as described in Example 3) was used.

After coating, the mixture was kept at 520 ° C for 15 minutes and fired to obtain a firm and uniform film having a thickness of 3.7 µm and a specific resistance of 8.0 µPa · cm.

Example 8

In Example 1, Au powder having an average particle size of 1.5 μm, a specific surface area of 2.8 m ² / g, and a density of 3.4 g / cm ³ was used as the conductive powder, and Au fine particles having an average particle diameter of 0.09 μm and a specific surface area of 8.5 m ² / g were used. The conductive paste composition of the present invention was prepared in the same manner except that glass frit B (as described in Example 3) was used.

After coating, the mixture was kept at 500 ° C. for 15 minutes and baked to obtain a firm and uniform film having a thickness of 3.4 μm and a resistivity of 4.2 μm · cm.

Example 9

Texanol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate) as an organic solvent: 60 parts by weight of the powder solid as in Example 1 and 40 parts by weight of the photosensitive organic component having the composition shown in Table 4 below The photosensitive conductive paste composition of the present invention was prepared in the same manner as in Example 1 except for dissolution.

Component Usage (part by weight) Polymer: A polymer obtained by adding 10 mol% of glycidyl methacrylate to a copolymer composed of 60 mol% of n-butyl methacrylate, 10 mol% of 2-hydroxypropyl methacrylate and 30 mol% of methacrylic acid (molecular weight 50,000, T _g 50 ° C, acid value 100) 8 Monomer: Pentaerythritol tri / tetraacrylate 4 Photopolymerization initiator: Irgacure 369 of Tiba specialty chemicals 1.6

The photosensitive conductive paste obtained as described above was applied to a soda glass substrate having a size of 100 mm × 100 mm by screen printing to form a coating film. The thickness after drying a coating film at 90 degreeC for 30 minutes was 8 micrometers.

A negative pattern mask (stripe-shaped pattern, a line width of 80 μm, a pitch of 230 μm) was attached to the coating film and exposed to ultraviolet rays (a light source: an ultrahigh pressure mercury lamp) by irradiation (400 mJ / cm ² ). Subsequently, an aqueous solution of 0.5% sodium carbonate at 30 ° C. was sprayed and developed to remove the exposed portion. Thereafter, pure water was sprayed to wash the developer, and then dried at 80 ° C. for 20 minutes. Subsequently, the temperature was raised at a rate of 200 ° C / hour and held at a maximum temperature of 480 ° C for 30 minutes to carry out firing.

The obtained conductive film was a rectangular film having a thickness of 3.3 µm and a resistivity of 2.4 µPa · cm, and was firmly adhered to the substrate without end peeling or edge curl.

The conductive paste according to the present invention can provide a thin film electrode pattern containing conductive fine particles together with conductive powder, which can be fired even at a relatively low temperature, and has high adhesive strength to the substrate and low resistance.

Claims (9)

100 parts by weight of conductive powder having an average particle diameter of 0.8 to 4 μm, 3 to 30 parts by weight of conductive fine particles having an average particle diameter of 0.02 to 0.1 μm, 0 to 10 parts by weight of glass frit, and an organic vehicle. Conductive paste composition for electrodes, comprising 3 to 30 parts by weight. The method of claim 1, A conductive powder or conductive fine particles is a composition, characterized in that at least one selected from the group consisting of Ag, Cu, Au, Pd, Ni and Pt. The method of claim 1, The composition characterized in that the conductive powder has a specific surface area in the range of 0.5 to 3.5 m ² / g. The method of claim 1, The composition characterized in that the conductive fine particles have a specific surface area in the range of 2 to 50 m ² / g. The method of claim 1, The glass frit is characterized in that the average particle diameter ranges from 0.3 to 2 μm and the maximum size is 4 μm or less. The method of claim 1, The glass frit, when expressed in terms of oxide, comprises 40 to 90 wt% of Bi ₂ O ₃ , 5 to 30 wt% of SiO _2, 5 to 30 wt% of B ₂ O _3, and BaO 2 to 40 wt% Composition. The method of claim 1, When the glass frit is expressed in oxide conversion, 40 to 90 wt% of PbO, 10 to 40 wt% of SiO ₂ , 5 to 30 wt% of B ₂ O ₃ , 0 to 10 wt% of ZnO and 0 to 20 of Al ₂ O _3. A composition comprising a weight percent. The method of claim 1, When the glass frit is expressed in terms of oxide, 40 to 90 wt% of Bi ₂ O _3, 40 to 90 wt% of PbO, 5 to 30 wt% of SiO _2, 5 to 30 wt% of B ₂ O ₃ , and ZnO 0 to 10 A composition comprising from 0% to 20% by weight and Al ₂ O ₃ . The method of claim 1, An organic vehicle comprises a photosensitive organic component comprising a photosensitive resin and a photopolymerization initiator.