JPH10130638A - Phosphor paste and method for manufacturing plasma display panel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a phosphor layer with an enough thickness to be formed on the bottom and side of a discharge cell by using a phosphor paste essentially contg. an inorg. phosphor powder and an org. component and having a specified viscosity. SOLUTION: This phosphor paste essentially contains an inorg. phosphor powder and an org. component, has a viscosity of 1-5 P, and pref. has a yield value S0 of 0-500mPa. The org. component pref. contains a photosensitive component. The inorg. phosphor powder is pref. the one represented by [(Y,Gd,Eu,) BO3 ] as red, the one represented by [(Zn,Mn)2 SiO4 ] as green, or the one represented by [(Ba,Eu)MgAl10 O17 ] as blue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a phosphor paste used for forming a phosphor layer of a plasma display panel (PDP) and a method of manufacturing a PDP using the same.

[0002]

2. Description of the Related Art At present, monochrome type PDPs are mainly used.
Even with the reduction in price, colorization of PDPs has been developed, and it is expected to be used by taking advantage of the advantages of high-speed display and easy upsizing.

[0003] With the expansion of applications, color PDPs having fine and large number of display cells corresponding to high-definition televisions have been receiving attention. PDP is structurally known as a counter electrode type and a surface discharge type, and the classification of applied voltage is direct current (DC).
Types and alternating current (AC) types are known. A color PDP is a display that excites a phosphor applied in a cell with ultraviolet light generated by gas discharge to obtain visible light and perform color display. In addition, since phosphors having different emission colors are applied in a stripe shape, it is possible to emit monochromatic light of an arbitrary color by selecting an appropriate phosphor and applying an address voltage.

In a conventional surface discharge type PDP, an address electrode is formed on a glass substrate as a back plate, and a partition layer is formed thereon. The phosphor layer can apply each color of red, green, and blue to a predetermined partition by using a photosensitive phosphor paste. The phosphor paste applied to the inside of the partition by screen printing or the like forms a phosphor layer through the steps of exposure, development, drying, and baking (Japanese Patent Application Laid-Open No. 6-267431).
No.).

[0005]

In a PDP, the shape of a phosphor layer formed in a rib is important in order to improve luminous efficiency with limited energy. In order to increase the emission luminance, it is desirable to apply a phosphor not only on the bottom but also on the side of the partition layer, but it is very difficult to form a phosphor layer on the side of the partition by the screen printing method. It has been applied. Therefore, there is a problem that the luminance is low.

In order for the phosphor layer thus formed to exhibit high brightness, it is necessary that the bottom and side surfaces in the discharge cell have a certain thickness. However, the flow of the paste causes surface tension and gravity to act, so that the phosphor tends to settle at the bottom and the phosphor is not applied to the side surfaces of the partition layer. for that reason,
There has been a problem that the viewing angle becomes narrow and the overall luminance of the display also decreases. Also, if the thickness is too thin, light is transmitted, the reflected light is reduced and the brightness is reduced, and at the same time there is a place where the imbalance of the discharge space cannot be ensured, and at that place, no discharge occurs and no light emission occurs. I have.

The present invention solves the above problems and provides a phosphor paste capable of forming a phosphor layer at a sufficient thickness on the bottom and side surfaces in a discharge cell. Another object of the present invention is to provide a method of manufacturing a plasma display panel that can cope with a larger screen and higher definition in the future.

[0008]

That is, the present invention relates to a phosphor paste comprising an inorganic phosphor powder and an organic component as essential components, wherein the phosphor paste has a viscosity ρ of 1 to 50.
(Poise).

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The phosphor paste of the present invention contains an inorganic phosphor powder and an organic component as essential components.

The phosphor powder used is not particularly limited, and known phosphor powders can be used. For example, in red, Y ₂ O ₃ : Eu, YVO ₄ : Eu, (Y, Gd) B
O ₃ : Eu, Y ₂ O ₃ S: Eu, γ-Zn ₃ (PO ₄ ) ₂ : M
n, (ZnCd) S: Ag + In ₂ O ₃ , Y ₂ SiO ₅ : E
u, Y ₂ Al ₅ O ₁₂ : Eu, Zn ₃ (PO ₄ ) ₂ : Mn, Y
BO ₃ : Eu, (Y, Gd) BO ₃ : Eu, GdBO ₃ :
Eu, ScBO ₃ P: Eu, LuBO ₃ : Eu and the like. In green, Zn ₂ GeO ₂ : Mn, BaAl ₁₂ O ₁₉ :
Mn, Zn ₂ SO ₄ : Mn, LaPO ₄ : Tb, ZnS:
Cu, Al, ZnS: Au, Cu, Al, (ZnC
d) S: Cu, Al, Zn ₂ SiO ₄ : Mn, As, As
Y ₃ Al ₅ O ₁₂ : Ce, CeMgAl ₁₁ O ₁₉ : Tb, Gd
_{There are 2} O ₂ S: Tb, Y ₃ Al ₅ O ₁₂ : Tb, ZnO: Zn and the like. In blue, Y ₂ SiO ₅ : Ce, CaWO ₄ :
Pb, BaMgAl ₁₄ O ₂₃ : Eu, Sr ₅ (PO ₄ ) ₃ C
1: Eu, BaMgAl ₁₆ O ₂₇ : Eu, BaMg ₂ Al
₁₄ O ₂₄ : Eu, ZnS: Ag + pigment (re
d), Y ₂ SiO ₃ : Ce.

Particularly, as the inorganic phosphor powder, [(Y, Gd, Eu) BO ₃ ] as red and [(Zn, M
n) ₂ SiO ₄ ] and blue ([Ba, Eu) MgAl ₁₀
By using the selected phosphor powder of [O ₁₇ ], a phosphor layer having high luminance and long life can be formed. Also,
At least one element selected from the group consisting of thulium (Tm), terbium (Tb), and europium (Eu), and at least one parent constituent selected from yttrium (Y), gadolinium (Gd), and lutetium (Lu) Rare earth tantalate phosphors substituted with rare earth elements can be used. Preferably, the rare earth tantalate phosphor has a composition formula of Y _1-x Eu _x TaO ₄ , wherein x is approximately 0.005.
~ 0.1) Europium-activated yttrium tantalate phosphor. For the red phosphor, europium-activated yttrium tantalate is preferable, and for the green phosphor, a rare earth tantalate phosphor is represented by a composition formula Y _1-x Tb _x
TaO ₄ (where, x is approximately 0.001 to 0.2) terbium-activated yttrium tantalate represented by are preferred. In the blue phosphor, a rare earth tantalate phosphor is Y _1-x Tb _x TaO ₄ (where x is about 0.001 to 0.001).
0.2 is preferred. Thulium-activated yttrium tantalate represented by the formula:

In the green phosphor, Mn contains 0.2% by weight or more based on the amount of zinc silicate (ZnSiO ₄ ).
A manganese-activated zinc phosphor (Zn ₂ SiO ₄ : Mn) having an average particle diameter of 2 to 8 μm activated with less than 0.1% by weight and a general formula of (Zn _2-x M _x ) O · αSiO ₂ (wherein , X and α are values in the range of 0.01 ≦ x ≦ 0.2 and 0.5 <α ≦ 1.5). The manganese-activated zinc silicate phosphor is preferred.

The amount of the phosphor powder is 40 to 85% by weight.
It is preferred that If it is less than 40% by weight, the shrinkage is too large and peeling or cracking occurs. If it exceeds 85% by weight, the shrinkage is too small and the phosphor layer becomes 50 μm or more.

The particle diameter of the phosphor powder used in the present invention is selected in consideration of the line width, width interval (space) and thickness of the phosphor layer pattern to be produced.
Weight% particle size is 1.5 to 15 μm, specific surface area is 0.1 to
It is preferably 2 m ² / G. More preferably, the particle diameter is ^{2 to} 10 μm, and the specific surface area is 0.2 to ¹ m ² / G. When it is in this range, light is sufficiently transmitted during ultraviolet exposure,
A highly accurate pattern shape can be obtained. Further, it is preferable because the luminous efficiency of the phosphor is good and the life is long. If the powder particle size is less than 1.5 μm and the specific surface area exceeds 2 m ² / G, the powder becomes too fine, light is scattered at the time of exposure, and the unexposed portion is light-cured. As a result, a residual film of the pattern (excess phosphor remains in the unexposed portion) occurs during development, and a high-definition pattern cannot be obtained. Further, the luminous efficiency and life of the phosphor are reduced.

As the shape of the phosphor powder, a polyhedral (granular) shape can be used, but a powder without aggregation is preferable. Among them, spherical powder is more preferable because the influence of scattering at the time of exposure can be reduced. Spherical powder has a sphericity of 80% by number
It is preferable to have the above particle shape. More preferably, the sphericity is 90% by number or more. Spherical ratio 80 number%
If it is less than 1, it is difficult to obtain a high-definition pattern due to the influence of the scattering of the phosphor powder during exposure to ultraviolet light. The sphericity was measured by measuring the phosphor powder with an optical microscope at 300 mm.
Photographing is performed at double magnification, and counting is performed by counting the number of particles that can be counted. The ratio of spherical particles is defined as the spherical ratio.

The organic component used in the present invention usually contains additives of an organic binder and a solvent.

Specific examples of the organic binder include polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol, cellulosic polymers (eg, methylcellulose, ethylcellulose, hydroxyethylcellulose, methylhydroxyethylcellulose), polyethylene, and silicone polymers (eg, polymethylsiloxane). , Polymethylphenylsiloxane), polystyrene, butadiene / styrene copolymer, polystyrene,
Polyvinyl pyrrolidone, polyamides, high molecular weight polyethers, copolymers of ethylene oxide and propylene oxide, polyacrylamide and various acrylic polymers (e.g., sodium polyacrylate, poly (lower alkyl acrylate), poly (lower alkyl methacrylate) and various lower alkyl acrylates and methacrylates Copolymers and multipolymers.

Specific examples of the solvent include methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, butyl carbitol acetate, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, and the like, and an organic solvent mixture containing at least one of these are used.

In the present invention, the organic component preferably contains a photosensitive compound so that a fine pattern can be formed. A photosensitive phosphor paste can be obtained by using an organic component containing a photosensitive compound. The organic component containing a photosensitive compound includes a photosensitive component selected from at least one of a photosensitive polymer, a photosensitive monomer, and a photosensitive oligomer, and further includes, if necessary, a photopolymerization initiator and a sensitizer ultraviolet ray. Additives such as light absorbers are also added. The amount of the organic component containing the photosensitive compound used in the present invention is preferably 15 to 60% by weight. If the content is less than 15% by weight, the patterning property deteriorates due to insufficient light exposure,
If the content is more than 10% by weight, the binder removal property at the time of firing is poor and the firing is insufficient.

The photosensitive component includes a photo-insolubilizing type and a photo-solubilizing type.
(A) containing a functional monomer, oligomer, or polymer having at least one unsaturated group in the molecule;
(B) those containing photosensitive compounds such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds;
(C) There is a so-called diazo resin such as a condensate of a diazo-based amine and formaldehyde. Also,
Examples of the photo-soluble type include (D) a complex of a diazo compound with an inorganic salt or an organic acid, a compound containing a quinone diazo compound, and (E) a compound in which a quinone diazo compound is bonded to an appropriate polymer binder, such as phenol or novolak. Examples of the resin include naphthoquinone 1,2-diazide-5-sulfonic acid ester. The photosensitive component used in the present invention,
All of the above can be used. As the photosensitive component which can be easily used as a photosensitive paste by being mixed with inorganic fine particles, (A) is preferred.

The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond, and specific examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, and sec-butyl. Acrylate, sec-
Butyl acrylate, iso-butyl acrylate, te
rt-butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate Heptadecafluorodecyl acrylate, 2-hydroxyethyl acrylate, isobonyl acrylate, 2-hydroxypropyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-
Methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenoxyethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate, 1,3-butylene Glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, methoxide Shi of cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate,
Trimethylolpropane triacrylate, acrylamide, aminoethyl acrylate, phenyl acrylate, phenoxyethyl acrylate, benzyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, bisphenol A diacrylate, diacrylate of bisphenol A-ethylene oxide adduct,
Bisphenol A-propylene oxide adduct diacrylate, thiophenol acrylate, benzyl mercaptan acrylate, and monomers in which 1 to 5 hydrogen atoms of these aromatic rings are substituted with chlorine or bromine atoms, or styrene, p -Methylstyrene,
o-methylstyrene, m-methylstyrene, chlorinated styrene, brominated styrene, α-methylstyrene, chlorinated α
-Methyl styrene, brominated α-methyl styrene, chloromethyl styrene, hydroxymethyl styrene, carboxymethyl styrene, vinyl naphthalene, vinyl anthracene, vinyl carbazole, and part or all of the acrylate in the molecule of the above compound to methacrylate Modified ones include γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone and the like. In the present invention, one or more of these can be used.

In addition to these, the developability after exposure can be improved by adding an unsaturated acid such as an unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

As the binder, polyvinyl alcohol, polyvinyl butyral, methacrylate polymer, acrylate polymer, acrylate ester
Examples include methacrylate copolymers, α-methylstyrene polymers, and butyl methacrylate resins. Further, an oligomer or polymer obtained by polymerizing at least one of the compounds having a carbon-carbon double bond described above can be used. At the time of polymerization, the content of these monomers is 10% by weight or more, more preferably 35% by weight.
It can be copolymerized with another photosensitive monomer so as to be at least% by weight. As a monomer to be copolymerized, the developability after exposure can be improved by copolymerizing an unsaturated acid such as an unsaturated carboxylic acid. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

The acid value of the polymer or oligomer thus obtained is preferably in the range of 50 to 180, more preferably 70 to 140. When the acid value is less than 50, the allowable development width becomes narrow. On the other hand, if the acid value exceeds 180, the solubility of the unexposed portion in the developing solution decreases, so that if the developing solution concentration is increased, peeling occurs up to the exposed portion, making it difficult to obtain a high-definition pattern.

By adding a photoreactive group to the side chain or molecular terminal of the polymer or oligomer described above, it can be used as a photosensitive polymer or oligomer having photosensitivity. Preferred photoreactive groups are those having an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acryl group, and a methacryl group. The method of adding such a side chain to an oligomer or a polymer includes an ethylenically unsaturated compound having a glycidyl group or an isocyanate group, a mercapto group, an amino group, a hydroxyl group, and a carboxyl group in the polymer, acrylic acid chloride, and methacrylic acid. There is a method of making an acid chloride or allyl chloride by an addition reaction. Examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl ether crotonic acid, glycidyl ether isocrotonic acid, and the like. Examples of the ethylenically unsaturated compound having an isocyanate group include (meth) acryloyl isocyanate and (meth) acryloylethyl isocyanate. In addition, ethylenically unsaturated compounds having a glycidyl group or an isocyanate group and acrylic acid chloride, methacrylic acid chloride or allyl chloride is a mercapto group in the polymer, an amino group,
It is preferable to add 0.05 to 1 molar equivalent to a hydroxyl group or a carboxyl group.

As specific examples of the photopolymerization initiator,
Benzophenone, methyl o-benzoylbenzoate, 4,
4-bis (dimethylamine) benzophenone, 4,4-
Bis (diethylamino) benzophenone, 4,4 dichlorobenzophenone, 4-benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2
-Diethoxyacetophenone, 2,2-dimethoxy-2
-Phenyl-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, Pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, benzyl Dimethyl ketanol, benzyl methoxyethyl acetal, benzoin, benzoin methyl ether, benzoin butyl ether, anthraquinone,
-T-butylanthraquinone, 2-amylanthraquinone, β-chloranthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4
-Azidobenzalacetophenone, 2,6-bis (P-
(Azidobenzylidene) cyclohexanone, 2,6-bis (P-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadione-2- (o-
Methoxycarbonyl) oxime, 1-phenyl-propanedione-2- (o-ethoxycarbonyl) oxime,
1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) oxime, Michler's ketone, 2-methyl- [4- (methylthio ) Phenyl] -2-morpholino-1-propanone,
Naphthalenesulfonyl chloride, quinoline sulfonyl chloride, n-phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyl disulfide,
Combination of photoreducing dyes such as benzothiazole disulfide, triphenylphorphine, camphorquinone, carbon tetrabromide, tribromophenylsulfone, benzoin peroxide and eosin, and methylene blue with reducing agents such as ascorbic acid and triethanolamine Is raised. In the present invention, one or more of these can be used.

The photopolymerization initiator is used in an amount of 0.1 to the photosensitive component.
It is added in the range of 1 to 6% by weight, more preferably, 0.1 to 6% by weight.
2 to 5% by weight. If the amount of the polymerization initiator is too small, the sensitivity to light becomes low, and if the amount of the photopolymerization initiator is too large, the residual ratio of the exposed portion may be too small.

Further, a paste characterized in that an organic dye is contained in the phosphor paste in an amount of 0.01 to 1.0% by weight. Becomes possible. Sudan 4 or the like is preferably used as the organic dye.

The photosensitive phosphor paste is usually prepared by mixing various components of a phosphor powder, a photosensitive polymer, a photosensitive monomer, a photopolymerization initiator, and a solvent so as to have a predetermined composition, and then kneading with three rollers or kneading. It is made by mixing and dispersing homogeneously in a machine.

The viscosity of the phosphor paste of the present invention can be appropriately adjusted by the addition ratio of the phosphor powder, the organic solvent, the organic binder and the like. In the phosphor paste, it is important that the viscosity ρ of the phosphor paste is in the range of 1 to 50 (poise). The phosphor layer formed of the phosphor paste having a viscosity of 1 to 50 (poise) can have an appropriate thickness. More preferably, the phosphor layer formed of a phosphor paste of 1 to 15 (poise) can form an ideal thickness of 10 to 50 μm. In particular, when the phosphor layer is formed by the application method of the screen printing method, it is necessary to adjust the viscosity in the range of 1 to 50 (poise) in consideration of printability in the partition. The phosphor paste printed by the screen printing method as described above can form a phosphor layer having a thickness of 10 to 50 μm by performing exposure, development, and drying.

The phosphor paste of the present invention further comprises
It is preferable to show a yield value S ₀ in the range of 500 (millipascal). The yield value of 0 to 500 (millipascal) is S
_The phosphor layer formed of the phosphor paste having ₀ can have an appropriate thickness. More preferably, 0 to
An ideal thickness of 10 to 50 μm can be formed in the phosphor layer having a yield value S ₀ of 200 (millipascal).

In the present invention, the viscosity ρ and the yield value S ₀ are indirectly measured by measuring the shear stress with respect to the shear rate. As a specific measuring method, it can be measured using a parallel cone E-type viscometer.

The method of manufacturing the plasma display panel of the present invention is not particularly limited, but a step of applying a photosensitive phosphor paste to an arbitrary place or the whole surface of a glass substrate on which an electrode layer and a partition layer are formed, and tilting the substrate. It is manufactured by forming a phosphor layer by a step of drying and baking.

The glass substrate is not particularly limited as long as it is a known one, but it is a general soda lime glass, a glass obtained by annealing a soda lime glass, or a glass having a high strain point (for example, “PD- manufactured by Asahi Glass Co., Ltd.”). 200 ") or the like can be used. The size of the glass substrate is not particularly limited, and glass having a thickness of 1 to 5 mm can be used.
On these glass substrates, silver, copper, gold, nickel, tin oxide, ITO, etc. are screen-printed or patterned by photolithography using a photosensitive conductive paste to form an electrode layer. In general, a glass substrate provided with partition walls made of a glass material containing boron oxide as an essential component is used. Further, a glass substrate having a dielectric layer on the electrode layer for stabilizing discharge may be used.

The electrode layer formed on the glass substrate has a pitch of 80 to 500 μm, preferably 80 to 200 μm.
After forming the partition layer, a phosphor paste having an appropriate viscosity and a yield value is applied to an arbitrary place. When a photosensitive phosphor paste is used, it may be applied to an arbitrary place or the whole surface. As a coating method, a known method such as screen printing, a bar coater, a roll coater, a die coater, and an inkjet coating can be used. The coating thickness can be adjusted by selecting the number of coatings, the gap of the coater, the mesh of the screen, and the viscosity of the paste.
It is necessary to have a thickness of 0 to 50 μm, and it is preferable to apply the coating with a thickness of about 20 to 80 μm in consideration of shrinkage due to drying and baking.

In the drying step, the paste is applied so as to obtain an appropriate thickness efficiently, and then dried with the applied surface down in order to uniformly form the phosphor layer on the side and bottom of the partition. The lower surface of the glass substrate means that the inclination of the glass substrate with respect to the horizontal direction is set to an angle of 0 to 30 degrees with the surface on which the electrodes, partition walls, and phosphors are formed on the glass substrate. Drying temperature is usually 5 to 6 at 50 to 150 ° C.
Perform for 0 minutes. Before the drying step, a leveling step of 1 to 15 minutes may be performed.

Although the method of manufacturing the plasma display of the present invention is not particularly limited, it is preferable to manufacture the plasma display by a photosensitive paste method which has few steps and can form a fine pattern. However, the present invention is not limited to this. In this case, as a forming method, a step of applying a photosensitive phosphor paste to an arbitrary place or the whole surface on a glass substrate on which an electrode layer and a partition layer are formed, a step of drying the substrate by inclining, a step of exposing, and a step of developing And firing. When using a photosensitive phosphor paste, the exposure step,
A development step is required.

Exposure is generally performed by a mask exposure using a photomask, as performed by ordinary photolithography. As the mask to be used, either a negative type or a positive type is selected depending on the type of the photosensitive organic component. Alternatively, a method of directly drawing with a laser beam or the like without using a photomask may be used. As the exposure device, a stepper exposure device, a proximity exposure device, or the like can be used. When performing large-area exposure, apply a photosensitive paste on a substrate such as a glass substrate, and then perform exposure while transporting, so that a large effective area is exposed using an exposure machine with a small effective exposure area. Can be. The active light source used at this time includes, for example, visible light, near ultraviolet light, ultraviolet light, electron beam, X-ray, laser light, etc. Among them, ultraviolet light is preferable. Mercury lamps, ultra-high pressure mercury lamps, halogen lamps, germicidal lamps and the like can be used. Among these, an ultra-high pressure mercury lamp is preferred. When a photomask is used, the design of the pattern width is important. Usually, the same width as the width (space) obtained by subtracting the partition wall width from the partition wall pitch is used. However, in consideration of alignment accuracy and light scattering at the time of exposure, a photomask having a pattern narrower than the space by 5 to 30 μm may be used. preferable.

These steps are defined as R (red), G (green), B
This process is performed for each of the colors (blue) to form a phosphor layer that emits light in a stripe shape.

Next, firing is performed in a firing furnace. The firing atmosphere and temperature vary depending on the type of the paste and the substrate, but firing is performed in an atmosphere of air, nitrogen, hydrogen, or the like. The firing temperature is usually 400 to 610 ° C. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used. During the above steps, a heating step at 50 to 300 ° C. may be introduced for the purpose of drying and preliminary reaction. The present invention is a method for manufacturing a plasma display panel, characterized in that the phosphor paste is formed by applying the phosphor paste, drying, exposing and developing if necessary, and then baking to form a phosphor layer. The glass substrate having the phosphor layer obtained by such a process can be used on the back side of the plasma display.

The glass substrate thus formed is sealed together with the front and rear glass substrates, and a rare gas such as helium, neon, or xenon is sealed therein, whereby a panel portion of the plasma display can be manufactured. Furthermore, by mounting a driver IC for driving, a plasma display can be manufactured.

[0042]

Embodiments of the present invention will be described below. However, the present invention is not limited to this.

Example 1 Each of the following organic components was dissolved while heating to 80 ° C. 17.8% by weight of polymer (glycidyl compound adduct of acrylic copolymer having ethylenically unsaturated group), 10.7% by weight of monomer (trimethylolpropane triacrylate (hereinafter referred to as TPA330)), photopolymerization initiator (2-methyl-
[4- (methylthio) phenyl] -2-morpholino-
0.2% by weight of 1-propanone (hereinafter referred to as IC907) and 28.8% by weight of a solvent (γ-butyrolactone).

Next, 42.5% by weight of green phosphor powder (Zn, Mn) ₂ SiO ₄ was added as a green phosphor paste, and the mixture was kneaded by a kneader to produce a green phosphor paste. The viscosity was adjusted by the amount of the solvent. Similarly, a red phosphor powder (Y, G
(d, Eu) BO ₃ and phosphor paste of each color were produced using blue phosphor powder (Ba, Eu) MgAl ₁₀ O ₁₇ as a blue phosphor paste. Next, 2 ml of the phosphor paste of each color was placed in a parallel cone E-type viscometer, and the rotation speed was 0.5, 1.0, 2.5, 5.0, 10.0.
A constant shear was applied for 3 minutes at each rpm, and the subsequent shear stress was measured. The viscosity and the yield value were determined from the measured values. Shear stress S (millipascal) is plotted against shear speed D, which is the reciprocal of each rotation speed, viscosity ρ (poise) is obtained from the slope by the least squares method, and yield value S ₀ (millipascal) is obtained from the y-intercept. ). Table 1 shows the results.

[0045]

[Table 1]

Next, at a pitch of 150 μm and a line width of 50 μm
m, electrode 5 μm thick, line width 30 μm, thickness 150 μm
The red phosphor paste was applied on the entire surface of the glass substrate on which the partition walls were formed by screen printing. Then, it was dried at 80 ° C. for 40 minutes with the coated side down. After drying, cool to room temperature and place a photomask on it. 100mJ / cm
Exposure was carried out with ² , and shower development was carried out with an alkaline aqueous solution. Then, it was placed in an oven at 80 ° C. for 20 minutes so that the moisture was sufficiently dried. The same procedure was applied to the green phosphor paste and the blue phosphor paste to form red, green, and blue striped patterns. A glass substrate on which each phosphor paste was patterned was baked at 500 ° C. for 30 minutes to prepare a PDP. The phosphor thickness was evaluated by observation with a laser microscope. Table 2 shows the results.

[0047]

[Table 2]

Example 2 Example 1 was used as the phosphor powder.
(Red: (Y, Gd, Eu) BO ₃ , green: (Zn,
Mn) ₂ SiO ₄ , blue: (Ba, Eu) MgAl ₁₀ O ₁₇ )
A phosphor paste was prepared in the same manner as in Example 1 except that powders having different particle size distributions were used. First, each of the organic components was dissolved while being heated to 80 ° C. And the polymer 1
7.8% by weight, 10.7% by weight of a monomer (TPA330), 0.2% by weight of a photopolymerization initiator (IC907), and 28.8% by weight of γ-Bl as a solvent were mixed. And
Green phosphor powder (Zn, M) as a green phosphor paste
n) 42.5% by weight of ₂ SiO ₄ was added and kneaded with a kneader to prepare a green phosphor paste. The viscosity can be adjusted by the amount of the solvent. Similarly, a red phosphor powder (Y, Gd, E) is used as a red phosphor paste.
u) Using BO ₃ , pastes of each color were prepared using blue phosphor powder (Ba, Eu) MgAl ₁₀ O ₁₇ as a blue phosphor paste.

Next, 2 ml of the phosphor paste of each color was placed in a parallel cone E-type viscometer, and the rotation speed was 0.5, 1.
A constant shear was applied at 0, 2.5, 5.0, and 10.0 rpm for 3 minutes each, and the subsequent shear stress was measured. The viscosity and the yield value were determined from the measured values. Shear stress S (millipascal) is plotted against shear speed D which is the reciprocal of each rotation speed, and the viscosity ρ
(Poise) was determined, and the yield value S ₀ (millipascal) was determined from the y-intercept. Table 3 shows the results.

[0050]

[Table 3]

The above-mentioned phosphor paste is applied by screen printing on the entire glass substrate on which an electrode having a pitch of 150 μm, a line width of 50 μm and a thickness of 5 μm and a partition having a line width of 30 μm and a thickness of 150 μm are formed. Then, it was dried at 80 ° C. for 40 minutes with the coated side down. After drying, cool to room temperature, put a photomask and expose at 100 mJ / cm ² ,
Furthermore, shower development was performed with an alkaline aqueous solution. Then, it was placed in an oven at 80 ° C. for 20 minutes so that the moisture was sufficiently dried. The same procedure was applied to the green photosensitive phosphor paste and the blue photosensitive phosphor paste to form red, green, and blue striped patterns. The glass substrate on which the phosphor paste was patterned was baked at 500 ° C. for 30 minutes to prepare a PDP. The phosphor thickness was evaluated by observation with a laser microscope. Table 4 shows the results.

[0052]

[Table 4]

Example 3 An inorganic dye powder was treated with an organic dye in order to enhance the effect of absorbing ultraviolet light during exposure. Sudan 4 was used as an organic dye having an ultraviolet absorbing effect.
Sudan 4 in 50 ml of acetone 0.18% of phosphor powder
The weight was added and the mixture was stirred with a stirrer for 5 minutes to prepare a solution in which Sudan 4 was previously dissolved in acetone. Next, each inorganic phosphor powder (red: 1% by weight of a dispersant added to acetone) was added to acetone.
(Y, Gd, Eu) BO ₃ , green: (Zn, Mn) ₂ SiO
₄ , blue: (Ba, Eu) MgAl ₁₀ O ₁₇ ).
The obtained mixed liquid was dried while being stirred for 30 minutes or more in a drafter to prepare a capsule-like powder having a powder surface coated with an organic film. This powder was dried in an oven at 100 ° C. for 2 hours. This phosphor powder was kneaded with other organic components described in Example 1 to prepare a phosphor paste.

[0054]

According to the present invention, a phosphor paste capable of forming a phosphor layer at a sufficient thickness on the bottom and side surfaces in the discharge cell can be provided. by this,
A high-brightness PDP can be easily obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01J 9/227 H01J 9/227 E

Claims (11)

[Claims] 1. A phosphor paste comprising an inorganic phosphor powder and an organic component as essential components, wherein the phosphor paste has a viscosity ρ of 1 to 50 (poise). . 2. The phosphor paste has a yield value S0 of ₀ to 500.
The phosphor paste according to claim 1, wherein the phosphor paste has a range of (millipascal). 3. The phosphor paste according to claim 1, wherein the organic component contains a photosensitive component. 4. The method according to claim 1, wherein the inorganic phosphor powder is [(Y, Gd, Eu) B].
O ₃ ], [(Zn, Mn) ₂ SiO ₄ ] and [(Ba,
Eu) MgAl ₁₀ O ₁₇ ]. 5. A phosphor paste containing an organic dye in an amount of 0.01 to 1;
The phosphor paste according to claim 1, wherein the phosphor paste is contained by weight. 6. A method of manufacturing a plasma display panel, comprising forming an electrode layer and a partition layer on a glass substrate and then forming a phosphor layer through respective steps of applying, drying and firing a phosphor paste. A method for manufacturing a plasma display panel, comprising using the phosphor paste according to any one of the preceding claims. 7. The method according to claim 6, wherein a phosphor layer is formed on a glass substrate on which a partition layer having a pitch of 80 to 200 μm is formed. 8. The method for manufacturing a plasma display panel according to claim 6, wherein in the drying step, a method is used in which the phosphor paste is applied, and then the drying is performed with the applied surface down. 9. The method of manufacturing a plasma display panel according to claim 6, wherein a phosphor layer is formed by firing, after applying, drying, exposing, and developing a phosphor paste. 10. A phosphor layer having a stripe shape of R (red), G
7. The method for manufacturing a plasma display panel according to claim 6, wherein each color of (green) and B (blue) is emitted. 11. A phosphor layer comprising R (red), G (green) and B
10-50 on both the bottom and side of each discharge cell (blue)
7. The method according to claim 6, wherein the plasma display panel is formed with a thickness of μm.