JP2009086280A - Photosensitive silver paste, method for producing electrode pattern, electrode pattern, and plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode pattern acquiring good chemical resistance and sufficient conductivity and reliability with high mass productivity. <P>SOLUTION: A silver paste pattern is formed using a photosensitive silver paste containing 100 parts by mass of a carboxyl group-containing organic binder (A), 400-800 parts by mass of silver powder (B), 0.1-70 parts by mass of glass frit (C), 0.1-10 parts by mass of an inorganic oxide (D) having an average particle diameter of 0.1-2 μm, 20-100 parts by mass of a photopolymerizable monomer (E), and 1-30 parts by mass of a photopolymerization initiator (F), a conductive paste pattern is formed so as to cover a part of the silver paste pattern, and the patterns are fired at the same time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrode pattern used for, for example, a plasma display and a manufacturing method thereof, and relates to a photosensitive silver paste used for forming an electrode pattern, an electrode pattern manufacturing method, an electrode pattern, and a plasma display panel.

  A plasma display panel (hereinafter abbreviated as PDP) is a flat display that displays images and information using light emission by plasma discharge, and is classified into a DC type and an AC type depending on the panel structure and driving method. The principle of color display by PDP is that plasma discharge is generated in a cell space (discharge space) between opposing electrodes formed on the front glass substrate and the rear glass substrate separated by ribs (partition walls) 8, and each cell The phosphor formed on the inner surface of the rear glass substrate is excited by ultraviolet rays generated by the discharge of a gas such as He or Xe enclosed in the space to generate visible light of the three primary colors. Each cell space is defined by grid-like ribs in the DC type PDP, and is defined by ribs arranged in parallel to the substrate surface in the AC type PDP. Made by ribs.

  FIG. 1 partially shows a structural example of a surface discharge type PDP having a three-electrode structure for full color display. On the lower surface of the front glass substrate 1, a pair of display electrodes 2a and 2b each comprising a transparent electrode 3a or 3b for discharging and a bus electrode 4a or 4b for lowering the line resistance of the transparent electrode are provided at a predetermined pitch. There are many rows. On these display electrodes 2a and 2b, a transparent dielectric layer 5 (low melting point glass) for accumulating charges is formed by printing and baking, and a protective layer (MgO) 6 is deposited thereon. . The protective layer 6 has a role of protecting the display electrode, maintaining a discharge state, and the like.

  On the other hand, on the rear glass substrate 7, striped ribs (partitions) 8 partitioning the discharge space and a large number of address electrodes (data electrodes) 9 arranged in each discharge space are arranged at a predetermined pitch. Yes. Further, phosphor films of three colors of red (10a), blue (10b), and green (10c) are regularly arranged on the inner surface of each discharge space. In full color display, red, blue, and green 3 The primary color phosphor films 10a, 10b, and 10c constitute one pixel. Further, on both sides of the pair of display electrodes 2a and 2b forming the discharge space, a striped black pattern is similarly formed in order to further increase the contrast of the image.

  Note that the PDP having such a structure is called a “surface discharge method” because an alternating pulse voltage is applied between the pair of display electrodes 2a and 2b to cause discharge between electrodes on the same substrate. The ultraviolet rays generated by the discharge excite the phosphor films 10a, 10b, and 10c of the rear glass substrate 7, and the generated visible light passes through the transparent electrodes 3a and 3b of the front substrate 1, thereby forming an image. .

Conventionally, silver electrodes have been used for the bus electrodes 4a and 4b and the address electrode 9 in the PDP having such a structure. However, the silver electrode has a drawback that sufficient chemical resistance cannot be obtained when chemical treatment such as nitric acid is performed in the production process of PDP. Thus, for example, Patent Document 1 discloses that chemical resistance is improved by forming a gold electrode on a silver electrode at a site where chemical treatment is performed.
JP 2003-031133 A

  Usually, a silver electrode and a gold electrode are formed by forming a pattern using a photosensitive silver paste and a gold paste, respectively, and baking. At this time, in order to reduce process cost and lead time and improve mass productivity, when a gold paste is applied onto a photosensitive silver paste and fired at the same time, a phenomenon such as swelling or breakage of the electrode joint portion occurs. Such a phenomenon becomes a defect of the electrode, causes a decrease in conductivity and reliability, and causes a decrease in performance and yield in the PDP.

  In recent years, high-definition full-spec high-definition is becoming mainstream in PDPs, and miniaturization of electrode patterns is required. In addition, there is a problem that the electrode pattern is more easily affected by electrode defects due to miniaturization of the electrode pattern.

  The present invention is a photosensitive silver for forming an electrode pattern capable of obtaining sufficient conductivity and reliability as well as good chemical resistance by mass firing with a conductive paste including a gold paste. The purpose is to provide a paste.

  Another object of the present invention is to provide a method for producing an electrode pattern that is highly mass-productive and that can obtain sufficient conductivity and reliability as well as good chemical resistance.

  Another object of the present invention is to provide an electrode pattern that can be miniaturized by having high mass productivity, good chemical resistance, and good electrical conductivity and reliability. .

  Furthermore, an object of the present invention is to provide a plasma display panel that is highly mass-productive, has good performance, and can cope with high definition.

  Usually, a photosensitive silver paste for forming a silver electrode contains a predetermined amount of glass frit to give adhesion to the base substrate, and is applied to the upper layer to form a gold electrode. The gold paste also contains glass frit in order to give adhesion to the base electrode (silver electrode). When the inventors laminated a photosensitive silver paste and a so-called conductive paste containing a gold paste and baked, the glass frit contained in the photosensitive silver paste and the glass frit contained in the conductive paste are mixed. As a result, the inventors have found that bubbles are generated inside the electrode and the electrode swells. Then, by adding amorphous silica having a predetermined particle diameter, it was found that mixing of the glass frit contained in the photosensitive silver paste and the glass frit contained in the conductive paste was suppressed, and the present invention was completed. It is.

  That is, according to one aspect of the present invention, silver powder (B) 400 to 800 parts by mass and glass frit (C) 0.1 to 70 parts by mass with respect to 100 parts by mass of the organic binder (A) containing a carboxyl group. And 0.1 to 10 parts by mass of an inorganic oxide (D) having an average particle size of 0.1 to 2 μm and selected from at least one of silica, titanium oxide, alumina, magnesium oxide and calcium oxide, a photopolymerizable monomer (E) The photosensitive silver paste characterized by containing 20-100 mass parts and 1-30 mass parts of photoinitiators (F) is provided.

  Moreover, in 1 aspect of this invention, silver powder (B) 400-800 mass parts, glass frit (C) 0.1-70 mass parts, average grain with respect to 100 mass parts of organic binders (A) containing a carboxyl group 0.1 to 10 parts by mass of inorganic oxide (D) having a diameter of 0.1 to 2 μm and selected from at least one of silica, titanium oxide, alumina, magnesium oxide and calcium oxide, photopolymerizable monomer (E) A photosensitive silver paste containing 20 to 100 parts by mass and 1 to 30 parts by mass of a photopolymerization initiator (F) is applied onto a substrate, and the applied photosensitive silver paste is dried, exposed and developed to produce silver. A paste pattern is formed, and a conductive paste is applied so as to cover a part of the silver paste pattern and dried to form a conductive paste pattern. Electrode pattern method for producing and firing bets pattern.

  In one embodiment of the present invention, there is provided a plasma display panel comprising the photosensitive silver paste and an electrode pattern formed using the electrode pattern manufacturing method.

  According to one embodiment of the present invention, the inorganic oxide is formed on the substrate and has an average particle diameter of 0.1 to 2.0 μm, and is selected from at least one of silica, titanium oxide, alumina, magnesium oxide, and calcium oxide. A glass component containing a product, a first electrode layer containing silver powder, and a second electrode layer containing a glass component and a conductive powder are formed to cover a part of the first electrode layer. There are provided an electrode pattern and a plasma display panel using the electrode pattern.

  According to the photosensitive silver paste of one aspect of the present invention, an electrode pattern capable of obtaining sufficient conductivity and reliability as well as good chemical resistance is formed with high productivity by co-firing with the conductive paste. It becomes possible to do.

  In addition, according to the method for manufacturing an electrode pattern of one embodiment of the present invention, it is possible to obtain sufficient conductivity and reliability as well as high chemical productivity and good chemical resistance.

  Further, according to the electrode pattern of one embodiment of the present invention, it is possible to miniaturize by having high mass productivity, good chemical resistance, and good conductivity and reliability.

  Furthermore, according to the plasma display panel of one embodiment of the present invention, it is possible to cope with high definition with high mass productivity and favorable performance.

  Hereinafter, embodiments of the present invention will be described.

  In this embodiment, the photosensitive silver paste is 400 to 800 parts by mass of silver powder (B) and 0.1 to 70 parts by mass of glass frit (C) with respect to 100 parts by mass of the organic binder (A) containing a carboxyl group. And 0.1 to 10 parts by mass of an inorganic oxide (D) having an average particle size of 0.1 to 2 μm and selected from at least one of silica, titanium oxide, alumina, magnesium oxide and calcium oxide, a photopolymerizable monomer (E) 20-100 mass parts and 1-30 mass parts of photoinitiators (F) are contained.

  Here, as the organic binder (A), a resin having a carboxyl group as an alkali-soluble resin, specifically, a carboxyl group-containing photosensitive resin itself having an ethylenically unsaturated double bond and an ethylenically unsaturated diester. Any of the carboxyl group-containing resins having no heavy bond can be used. Specific examples include the following.

(1) a carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and a compound having an unsaturated double bond such as methyl (meth) acrylate,
(2) A copolymer of an unsaturated carboxylic acid such as (meth) acrylic acid and a compound having an unsaturated double bond such as methyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid chloride, etc. A carboxyl group-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant,
(3) A copolymer of an epoxy group such as glycidyl (meth) acrylate and an unsaturated double bond and a compound having an unsaturated double bond such as methyl (meth) acrylate, (meth) acrylic acid, etc. A carboxyl group-containing photosensitive resin obtained by reacting an unsaturated carboxylic acid of the product, and reacting a polybasic acid anhydride such as tetrahydrophthalic acid anhydride with the generated secondary hydroxyl group,
(4) To a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and a compound having an unsaturated double bond such as styrene, a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and A carboxyl group-containing photosensitive resin obtained by reacting a compound having a saturated double bond;
(5) A carboxyl obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid such as (meth) acrylic acid, and reacting the resulting secondary hydroxyl group with a polybasic acid anhydride such as tetrahydrophthalic anhydride. Group-containing photosensitive resin,
(6) An epoxy group of a copolymer of an unsaturated double bond such as methyl (meth) acrylate and a glycidyl (meth) acrylate has one carboxyl group in one molecule, and an ethylenically unsaturated bond A carboxyl group-containing resin obtained by reacting an organic acid not having a hydrogen atom, and reacting a polybasic acid anhydride with the generated secondary hydroxyl group,
(7) a carboxyl group-containing resin obtained by reacting a polybasic acid anhydride with a hydroxyl group-containing polymer such as polyvinyl alcohol, and (8) a hydroxyl group-containing polymer such as polyvinyl alcohol with a polytetrahydrophthalic anhydride or the like. Examples include carboxyl group-containing photosensitive resins obtained by further reacting a carboxyl group-containing resin obtained by reacting a basic acid anhydride with a compound having an unsaturated double bond with an epoxy group such as glycidyl (meth) acrylate. In particular, the resins (1), (2), (3), and (6) are preferably used.

  In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

  These carboxyl group-containing resins and carboxyl group-containing photosensitive resins may be used alone or in combination, but in any case, they may be blended in a proportion of 10 to 80% by mass of the total amount of the composition. preferable. When the blending amount of these polymers is less than the above range, the distribution of the resin in the film to be formed tends to be non-uniform, and it is difficult to obtain sufficient photocurability and photocuring depth, and selective exposure and development. Makes patterning difficult. On the other hand, if it is more than the above range, it is not preferable because the pattern during baking and the line width shrinkage are likely to occur.

  The carboxyl group-containing resin and the carboxyl group-containing photosensitive resin each have a weight average molecular weight of 1,000 to 100,000, preferably 5,000 to 70,000, and an acid value of 50 to 250 mgKOH / g, and carboxyl In the case of a group-containing photosensitive resin, those having a double bond equivalent of 350 to 2,000, preferably 400 to 1,500 can be suitably used. If the molecular weight of the resin is lower than 1,000, the adhesion of the film during development is adversely affected. On the other hand, if the molecular weight is higher than 100,000, poor development is likely to occur. On the other hand, when the acid value is lower than 50 mgKOH / g, the solubility in an alkaline aqueous solution is insufficient and development failure tends to occur. On the other hand, when the acid value is higher than 250 mgKOH / g, the adhesion of the film is deteriorated during development and the photocured part (exposure Part) will be dissolved. Further, in the case of a carboxyl group-containing photosensitive resin, if the double bond equivalent of the photosensitive resin is less than 350, a residue is likely to remain at the time of baking, whereas if it is greater than 2,000, a work margin at the time of development. Narrow, and a high exposure amount is required at the time of photocuring.

  The photopolymerizable monomer (E) is used for promoting photocurability and improving developability of the composition. For example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polyurethane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, tri Methylolpropane ethylene oxide modified triacrylate, trimethylolpropane propylene oxide modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and each methacrylate corresponding to the above acrylate; phthalic acid, adipic acid, maleic acid, itaconic acid, Succinic acid, trimellitic acid, Examples include mono-, di-, tri- or higher polyesters of polybasic acids such as phthalic acid and hydroxyalkyl (meth) acrylates, but are not limited to specific ones. Or two or more types can be used in combination. Among these photopolymerizable monomers, polyfunctional monomers having two or more acryloyl groups or methacryloyl groups in one molecule are preferable.

  The amount of such photopolymerizable monomer (E) is suitably 20 to 100 parts by mass per 100 parts by mass of the organic binder (carboxyl group-containing photosensitive resin and / or carboxyl group-containing resin) (A). When the blending amount of the photopolymerizable monomer (E) is less than the above range, it is difficult to obtain sufficient photocurability of the composition. On the other hand, when the amount exceeds the above range, the surface is larger than the deep part of the film. Since the photo-curing of the part is accelerated, uneven curing is likely to occur.

  Specific examples of the photopolymerization initiator (F) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone. Acetophenones such as 2,2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl Aminoacetophenones such as 1-butanone; 2- Anthraquinones such as tilanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc. Thioxanthones; ketones such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4 , 6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphine Phosphine oxide such as Fineito; various peroxides and the like can be used alone or in combination of two or more of these conventionally known photopolymerization initiator.

  The blending ratio of these photopolymerization initiators (F) is suitably 1 to 30 parts by mass per 100 parts by mass of the organic binder (carboxyl group-containing photosensitive resin and / or carboxyl group-containing resin), preferably Is 5 to 20 parts by mass.

  The photopolymerization initiator (F) is composed of N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine. It can be used in combination with one or more photosensitizers such as tertiary amines.

  Furthermore, when a deeper photocuring depth is required, a titanocene photopolymerization initiator such as Irgacure 784 manufactured by Ciba Specialty Chemicals, which starts radical polymerization in the visible region, and leuco dyes are cured as necessary. It can be used in combination as an auxiliary agent.

  Further, as the silver powder (B), a spherical shape, a flake shape, and a resin shape can be used, but it is preferable to use a spherical shape in consideration of optical characteristics and dispersibility. The average particle diameter is preferably 0.5 to 3.0 μm from the viewpoint of resolution. Then, in order to prevent oxidation of these silver powders, to improve dispersibility in the composition, and to stabilize developability, it is preferable to perform treatment with a fatty acid. Examples of the fatty acid include oleic acid, linoleic acid, linolenic acid, stearic acid, and the like.

  As a compounding quantity of such silver powder (B), it can be set as 400-800 mass parts with respect to 100 mass parts of organic binders (A) containing a carboxyl group. If the amount is less than 400 parts by mass, sufficient conductivity of the conductor pattern obtained from the paste cannot be obtained. On the other hand, if the amount exceeds 800 parts by mass, the light transmittance is reduced, and the composition has sufficient light. This is because it becomes difficult to obtain curability.

  The glass frit (C) having a softening point (SP) of 400 ° C. to 600 ° C. and a glass transition temperature of 300 to 500 ° C. can be used. From the viewpoint of resolution, the average particle diameter is preferably 10 μm or less, and preferably 3 μm or less.

  And the compounding quantity of such a glass frit (C) can be 0.1-70 mass parts with respect to 100 mass parts of organic binders (A) containing a carboxyl group. Furthermore, in order to improve adhesiveness with a board | substrate, it is preferable to set it as 6-8 mass% with respect to the photosensitive silver paste total amount. When the amount is less than 6% by mass, sufficient adhesion cannot be obtained after firing. On the other hand, when the amount exceeds 8% by mass, the resistance value increases and the conductivity decreases.

  Furthermore, as an inorganic oxide (D), an average particle diameter of 0.1-2 micrometers can be used. Further, in terms of resolution, it is preferably 0.1 to 1 μm. Moreover, in order to suppress the bubble generation at the time of baking, it is preferable to use a nonporous thing. This is because the glass frit can be effectively prevented from being mixed by using a spherical one. In addition, the spherical shape as used in the field of this invention means what measured the long side and short side of arbitrary 10 points from the projection image by SEM, and the average of the ratio is 0.9-1.1.

  The compounding quantity of such an inorganic oxide (D) can be 0.1-10 mass parts with respect to 100 mass parts of organic binders (A) containing a carboxyl group. This is because if the amount is less than 0.1 parts by mass, there is no sufficient reduction effect against swelling, and if the amount exceeds 10 parts by mass, the resistance value of the electrode increases.

  As such an inorganic oxide, silica, titanium oxide, alumina, magnesium oxide, calcium oxide, or the like can be used. These inorganic oxide films are preferably amorphous.

  Furthermore, an appropriate amount of an organic solvent can be blended as the solvent. Specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, di Glycol ethers such as propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, 2, 2 Esters such as 1,4-trimethyl-1,3-pentanediol monoisobutyrate; ethanol, propanol Alcohols such as ethylene glycol, propylene glycol and terpineol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha, 2,2,4-trimethyl-1 , 3-pentanediol monoisobutyrate and the like, and these can be used alone or in combination of two or more.

  Moreover, when a large amount of inorganic powder is blended with the photocurable resin composition, the storage stability of the resulting composition is poor, and the coating workability tends to be deteriorated due to gelation and fluidity deterioration. Therefore, in order to improve the storage stability of the composition, a compound having an effect such as complexing or salt formation with a metal or oxide powder which is a component of the inorganic powder can be added as a stabilizer. Examples of the stabilizer include acids such as malonic acid, adipic acid, formic acid, acetic acid, acetoacetic acid, citric acid, stearic acid, maleic acid, fumaric acid, phthalic acid, and the like, either alone or in combination of two or more. Can be used in combination.

  Furthermore, additives such as silicone-based and acrylic-based antifoaming / leveling agents and silane coupling agents for improving the adhesion of the film can be blended as necessary.

  Further, if necessary, a known and conventional antioxidant, a thermal polymerization inhibitor for improving thermal stability during storage, a metal oxide as a binding component with the substrate during firing, silicon oxide, Fine particles such as boron oxide can also be added.

  The photosensitive silver paste thus configured is applied onto a substrate, the applied photosensitive silver paste is dried, exposed and developed to form a silver paste pattern, and a part of the silver paste pattern is covered As described above, the conductive paste is applied and dried to form a conductive paste pattern, and the silver paste pattern and the conductive paste pattern are baked to form the electrode pattern.

  Here, as the conductive paste, for example, a paste containing conductive powder containing Au, Ag, Cu, Pd, Pt, Al, Ni, W, glass frit, resin, or the like can be used.

  The average particle diameter of the conductive powder used for such a conductive paste is preferably 0.01 to 5 μm. If it is less than 0.01 μm, it is difficult to produce and the cost is high, and if it exceeds 5 μm, the denseness is poor and the resistance value is high. More preferably, it is 0.05-1 micrometer.

  The conductive powder constituting the conductive paste may have any shape such as a spherical shape, an indeterminate shape, a lump shape, a scale shape, a needle shape, or a rod shape.

  The conductive powder preferably contains Au. In addition, when noble metal powder other than Au is added thereto, it is sufficient if it has sinterability. For example, each powder such as Ag, Cu, Pd, Pt, Al, Ni, and W, or a mixed powder or alloy powder of two or more of these can be used. Silver powder is particularly preferable. And it is preferable that the compounding quantity is 1-80 weight part with respect to 100 weight part of gold powder. This is because if the amount is less than 1 part by weight, the printability is deteriorated, and if it exceeds 80 parts by weight, sufficient chemical resistance cannot be obtained. More preferably, it is 5-30 weight part.

  At this time, the average particle size of the silver powder is desirably 0.01 to 5 μm, and preferably 0.05 to 5 μm. If it is less than 0.01 μm, it is difficult to produce and the cost is high, and if it exceeds 5 μm, the denseness of the electrode part formed using such a conductive paste is poor and the resistance value is high, and the printability is also poor. It is to become.

As the glass frit, for example, a glass frit having a softening point of 400 to 600 ° C., a thermal expansion coefficient α ₃₀₀ of 35 × 10 ^{−7 to} 350 × 10 ⁻⁷ / ° C., and a glass transition temperature of 300 to 500 ° C. is used. It is desirable to use a glass frit that does not contain an alkali oxide, such as a ZnO-based glass or a B ₂ O ₃ -alkaline earth metal oxide-based glass.

  When the softening point of the glass frit exceeds 600 ° C., it is necessary to increase the firing temperature. For example, when the heat resistance of the electrode pattern formed body such as a substrate is low, thermal deformation occurs in the firing stage. If the temperature is less than 400 ° C., the glass frit is fused before the organic components are completely decomposed, volatilized and removed by firing, and voids are likely to be formed in the formed electrode pattern.

Further, when the thermal expansion coefficient α ₃₀₀ O of the glass frit is less than 35 × 10 ⁻⁷ / ° C. or exceeds 350 × 10 ⁻⁷ / ° C., the difference from the thermal expansion coefficient of the electrode pattern formed body. May become too large, resulting in distortion. The particle size (D50) of the glass frit is in the range of 0.1 to 5 μm, preferably 0.5 to 4 μm.

  And it is preferable that the compounding quantity of a glass frit is 1-20 weight part of glass frit with respect to 100 weight part of gold powder. This is because if the amount is less than 1 part by weight, the adhesion to the glass substrate is deteriorated, and if it exceeds 20 parts by weight, the resistance value is increased.

  Furthermore, an inorganic filler and an inorganic pigment can be used as an inorganic component other than the conductive powder and glass frit as necessary.

  In addition, as the resin, cellulose derivatives such as ethyl cellulose, hydroxypropyl cellulose, methyl cellulose, nitrocellulose, polyester resins such as polyacrylic ester and alkyd resin, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid , Vinyl acetate, methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, 2-hexyl acrylate, lauryl methacrylate, stearyl methacrylate, stearyl Acrylate, dodecyl methacrylate, dodecyl acrylate, hexyl methacrylate, octi Methacrylate, octyl acrylate, cetyl methacrylate, cetyl acrylate, nonyl acrylate, decyl methacrylate, decyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, 2 (2-ethoxyethoxy) ethyl acrylate, 2-hydroxyethyl methacrylate, diacetone acrylamide, N, N-diethylacrylamide, N, N-dimethylaminopropylacrylamide, isopropylacrylamide, diethylaminoethyl methacrylate, t-butyl methacrylate, N, N-dimethylacrylamide, α-methylstyrene, Styrene, vinyl toluene, N-vinyl Use a copolymer made of a monomer such as 2-pyrrolidone, an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, an polyolefin resin such as an ethylene-vinyl acetate copolymer, polyvinyl formal, polyvinyl butyral, etc. Can do. And it is preferable that the compounding quantity of resin is 2-10 weight part with respect to 100 weight part of gold powder.

  Furthermore, as solvents, terpenes such as α-, β-, and γ-terpineol, ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetate , Ethylene glycol dialkyl ether acetates, diethylene glycol dialkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol dialkyl ether acetates, methanol, ethanol, isopropanol, 2 -Ethylhexanol, 1-butoxy-2-propyl Examples include alcohols such as ropanol, fatty acid esters of mono- or polyalcohols, and these may be used alone or in combination of two or more.

  Furthermore, a plasticizer, an anti-settling agent, a dispersant, an antifoaming agent, a dye, a silane coupling agent, a thickener, and a leveling agent can be appropriately used as necessary.

  Then, using such a photosensitive silver paste and a gold paste, an electrode pattern is formed as follows.

  First, for example, a photosensitive silver paste is applied on a glass substrate that is a back glass substrate of a PDP. At this time, as a coating method, a patterning method such as a screen printing method or an offset printing method can be used.

  Next, the applied photosensitive silver paste is dried. At this time, by using a hot air circulation drying furnace, a far-infrared drying furnace or the like, for example, by drying at 60 to 120 ° C. for about 5 to 40 minutes, the organic solvent is evaporated and a tack-free coating film is obtained.

Then, the dried photosensitive silver paste coating film is selectively exposed. At this time, contact exposure and non-contact exposure using a negative mask having a predetermined exposure pattern can be used. As the exposure light source, a halogen lamp, a high-pressure mercury lamp, a laser beam, a metal halide lamp, an electrodeless lamp, or the like is used. The exposure amount is preferably about 50 to 1000 mJ / cm ² .

  And a predetermined silver paste pattern is formed by developing the coating film of the exposed photosensitive silver paste. At this time, a spray method, a dipping method or the like is used as a developing method. Developers include aqueous alkali metal solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium silicate, and aqueous amine solutions such as monoethanolamine, diethanolamine and triethanolamine, especially about 1.5% by mass or less. A dilute alkaline aqueous solution having a concentration of 5 is preferably used. In addition, it is not limited to these developing solutions, What is necessary is just to saponify the carboxyl group of carboxyl group-containing resin in a composition, and to remove an unhardened part (unexposed part). Moreover, it is preferable to carry out water washing and acid neutralization after the development in order to remove an unnecessary developer.

  A conductive paste containing a conductive powder such as Au is applied so as to cover a part of the silver paste pattern thus formed, thereby forming a conductive paste pattern. The conductive paste is applied by screen printing or the like, similar to the photosensitive silver paste, and dried in the same manner as the photosensitive silver paste.

  In this way, the substrate on which the silver paste pattern and the conductive paste pattern covering a part thereof are formed is heat-treated at 580 to 600 ° C. for 5 to 30 minutes in the air or in a nitrogen atmosphere. The paste pattern and the conductive paste pattern are fired simultaneously. The temperature increase rate in that case shall be 5-30 degreeC / min, for example.

  By baking, the organic component contained in the silver paste pattern and the conductive paste pattern is burned out, a glass component containing amorphous silica having an average particle size of 0.1 to 2.0 μm, an electrode layer containing silver powder, and this silver powder An electrode pattern having a glass component and an electrode layer containing a conductive powder such as Au is formed so as to cover a part of the electrode layer containing.

  2 is a top view of the electrode pattern formed on the back glass substrate, and FIG. 3 is a cross-sectional view taken along the line CC ′ of FIG. In FIG. 2, only the display area of the address electrode and the terminal portion are shown in a plan view. As shown in the figure, a part (end) of the electrode layer 11 containing silver powder in the terminal portion is covered with an electrode layer 12 containing conductive powder such as Au.

  The electrode pattern thus formed is used as the bus electrodes 4a and 4b and the address electrode 9 shown in FIG.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, it cannot be overemphasized that this invention is not limited to the following Example. In the following, “parts” are all parts by mass unless otherwise specified.

The glass frit in Table 1 is a bismuth oxide (Bi ₂ O ₃ ) glass frit.

  A flask equipped with a thermometer, stirrer, dropping funnel, and reflux condenser is charged with methyl methacrylate and methacrylic acid at a molar ratio of 0.87: 0.13, diethylene glycol monomethyl ether acetate as a solvent, and azobisisobutyrate as a catalyst. Ronitrile was added and stirred at 80 ° C. for 2 to 6 hours under a nitrogen atmosphere to obtain a resin solution. This resin solution was cooled, and methylhydroquinone as a polymerization inhibitor and tetrabutylphosphonium bromide as a catalyst were taken out after cooling to produce an organic binder (A1). This organic binder (A) had a weight average molecular weight of about 10,000 and an acid value of 95 mgKOH / g.

  In addition, the measurement of the weight average molecular weight of the obtained copolymer resin is Shimadzu Corporation pump LC-6AD, Showa Denko Co., Ltd. column Shodex (trademark) KF-804, KF-803, KF-802. Was measured by high performance liquid chromatography.

As the glass frit, a lead-free glass frit composed of Bi ₂ O ₃ , B ₂ O ₃ , ZnO, SiO ₂ and BaO was crushed to an average particle diameter of 1.6 μm was used. Glass frit A having a softening point of 583 ° C. and glass frit B having a softening point of 542 ° C. and glass frit C having a softening point of 542 ° C. were used. The softening point of the glass frit was determined by differential thermal analysis, using alumina powder as a standard substance, raising the temperature from room temperature to 800 ° C. at a rate of temperature increase of 10 ° C./min. did.

  As the inorganic oxide, amorphous silica was used, amorphous silica A having an average particle diameter of 0.5 μm and amorphous silica B having an average particle diameter of 7 nm.

The mixture was blended at the composition ratio shown in Table 2, and after stirring with a stirrer, the mixture was kneaded with a three-roll mill to form a paste.

About each photosensitive silver paste of Table 2, after apply | coating on a glass substrate using a 300 mesh polyester screen, it dried for 20 minutes at 90 degreeC in the far-infrared drying furnace, and formed the tack-free coating film. Thereafter, a metal halide lamp was used as the light source, and exposure was performed using a striped negative mask having a line width of 80 μm and a space width of 100 μm so that the integrated light amount on the coating film was 300 mJ / cm ² . Development was performed for 20 seconds using a 4 wt% Na ₂ CO ₃ aqueous solution, followed by washing with water and drying by air blow to prepare a silver paste pattern.

  About the produced silver paste pattern, the connection part electrode swelling was evaluated with the following method.

  A conductive paste made of the composition shown in Table 1 is printed on the connection part of the silver paste pattern after development, and the pattern is printed on the connection part using a 325-mesh SUS screen. Dried to form a tack-free coating.

  Next, baking was performed at a temperature rising rate of 20 ° C./min and 600 ° C. for 10 minutes, and the presence or absence of swelling of the connection electrode was observed with a microscope.

  The presence or absence of swelling of the connection part electrode was evaluated by ○ and ×.

○: No swelling ×: With swelling As is clear from the results shown in Table 2, the photosensitive silver paste according to this example produced a high-definition electrode pattern with a line width of 80 μm and a space width of 100 μm, and a silver paste pattern and conductivity. It could be produced by simultaneous firing of the paste pattern. In addition, the electrode pattern manufacturing method according to the present embodiment enables the electrode pattern to be formed without swelling at the connection portion even when the silver paste pattern and the conductive paste pattern are overlapped at least partially in the same state. there were.

  The electrode pattern according to the present embodiment thus formed has sufficient conductivity, and the electrode layer containing conductive powder is formed so as to cover the electrode layer containing silver powder. Good chemical resistance could be obtained.

The partial exploded perspective view of a surface discharge type AC type PDP. The top view of the pattern of the electrode formed on the back glass substrate. Sectional drawing of C-C 'of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front glass substrate 2a, 2b Display electrode 3a, 3b Transparent electrode 4a, 4b Bus electrode 5 Transparent dielectric layer 6 Protective layer 7 Back glass substrate 8 Rib 9 Address electrode 10a, 10b, 10c Phosphor film 11 Electrode layer containing silver powder 12 Electrode layer containing conductive powder

Claims (13)

  Silver powder (B) 400-800 parts by mass, glass frit (C) 0.1-70 parts by mass, and average particle size 0.1-2 μm with respect to 100 parts by mass of the organic binder (A) containing a carboxyl group. Inorganic oxide (D) selected from at least one selected from silica, titanium oxide, alumina, magnesium oxide and calcium oxide, 0.1 to 10 parts by weight, photopolymerizable monomer (E) 20 to 100 parts by weight, photopolymerization A photosensitive silver paste comprising 1 to 30 parts by mass of an initiator (F).   The photosensitive silver paste according to claim 1, wherein the inorganic oxide (D) is spherical.   The photosensitive silver paste according to claim 2, wherein the inorganic oxide (D) is amorphous.   The photosensitive silver paste according to any one of claims 1 to 3, wherein the glass frit (C) is contained in an amount of 6 to 8% by mass based on the total amount of the photosensitive silver paste. The photosensitive silver paste according to any one of claims 1 to 4 is applied on a substrate,
The coated photosensitive silver paste is dried, exposed and developed to form a silver paste pattern,
A conductive paste is applied so as to cover a part of the silver paste pattern, and dried to form a conductive paste pattern.
A method for producing an electrode pattern, comprising firing the silver paste pattern and the conductive paste pattern.   6. The method of manufacturing an electrode pattern according to claim 5, wherein the conductive paste includes conductive particles containing at least Au, Ag, Cu, Pd, Pt, Al, Ni, and W. A glass component formed on a substrate and containing an inorganic oxide having an average particle size of 0.1 to 2.0 μm, a first electrode layer containing silver powder,
An electrode pattern comprising a second electrode layer formed so as to cover a part of the silver electrode layer and containing a glass component and conductive particles.   The electrode pattern according to claim 7, wherein the inorganic oxide is silica, titanium oxide, alumina, magnesium oxide, or calcium oxide.   The electrode pattern according to claim 7 or 8, wherein the inorganic oxide is amorphous.   The electrode pattern according to any one of claims 7 to 9, wherein the conductive particles include at least Au, Ag, Cu, Pd, Pt, Al, Ni, and W.   A plasma display panel comprising an electrode pattern formed using the photosensitive silver paste according to any one of claims 1 to 4.   A plasma display panel comprising an electrode pattern formed by using the electrode pattern manufacturing method according to claim 5.   A plasma display panel comprising the electrode pattern according to any one of claims 7 to 10.

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