JPH10283927A - Ac plasma display panel and method for forming its phosphor surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize drive after a phosphor surface is formed into a panel by preventing a phosphor from being left behind at the tops of cell barriers when forming the phosphor surface using photolithography. SOLUTION: To form the phosphor surface of an AC type plasma display panel, having on its front plate combination electrodes each comprising a maintaining electrode and a bus electrode, and having on its back plate address electrodes crossing the combination electrodes at right angles and cell barriers 14 placed upright between the address electrodes, with the phosphor surface formed over the wall and bottom surfaces of the cell barriers 14, the process of forming a phosphor paste layer 16 by coating at least cell spaces with a photosensitive phosphor paste and drying the paste and the process of leaving the phosphor paste layer 16 behind in a predetermined cell space by performing back exposure and development are repeated by the necessary number of colors, and via a subsequent baking process the phosphor surface is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluorescent screen of a plasma display panel (hereinafter, referred to as PDP) which is a self-luminous flat display utilizing gas discharge.

[0002]

2. Description of the Related Art In general, a PDP has a structure in which a pair of electrodes arranged regularly on two opposing glass substrates are provided, and a gas mainly composed of Ne, Xe or the like is sealed between the electrodes. Then, a voltage is applied between these electrodes,
By generating a discharge in a minute cell space around the electrode, each cell emits light to perform display.
In order to display information, regularly arranged cells are selectively caused to emit light. There are two types of PDPs, a direct current type (DC type) in which the electrodes are exposed to the discharge space, and an alternating current type (AC type) in which the electrodes are covered with an insulating layer. And a refresh driving method and a memory driving method.

FIG. 1 shows a configuration example of an AC type PDP. This figure shows the front plate and the back plate separated from each other. As shown in the figure, two glass substrates 1 and 2 are arranged in parallel and opposed to each other, and both become the back plate. The cell barriers 3 provided on the glass substrate 2 in parallel to each other are held at regular intervals. On the back side of the glass substrate 1 serving as a front plate, composite electrodes composed of a transparent electrode serving as a sustain electrode 4 and a metal electrode serving as a bus electrode 5 are formed in parallel with each other, and a dielectric layer 6 is covered thereover. The protective layer 7 (MgO layer) is further formed thereon. On the front side of the glass substrate 2 serving as a back plate, address electrodes 8 are formed between the cell barriers 3 so as to be perpendicular to the composite electrode and parallel to each other. A layer 9 is formed, and the fluorescent material 1 is further covered so as to cover the wall surface of the cell barrier 3 and the cell bottom surface.
0 is provided. The AC type PDP is of a surface discharge type, and has a structure in which an AC voltage is applied between composite electrodes on a front panel to discharge by an electric field leaking into a space. In this case, since the alternating current is applied, the direction of the electric field changes according to the frequency. Then, the phosphor 10 emits light by the ultraviolet light generated by the discharge, so that an observer can visually recognize the light transmitted through the front plate.

[0004]

As a method of forming the reflective phosphor screen as described above, a method of selectively filling a phosphor paste of three colors into a cell space by screen printing and then firing the phosphor paste is known. Is being done. This method
In addition to using less expensive phosphor, the coating step and the patterning step can be performed at the same time, so that the process is simple and there are great advantages in both productivity and cost. However, this screen printing method also has a problem. Especially when forming a large area, high definition phosphor screen,
It is difficult to maintain accuracy due to plate elongation and the like, and if there is only a slight alignment error, the phosphor may easily adhere to the upper part of the cell barrier. The phosphor adhered to the upper part of the cell barrier in this way makes the gap distance between the substrates unstable when panelized, causes color mixing by scattering, and makes the driving voltage unstable by contacting the electrodes. May cause problems. Therefore, in order to prevent a phosphor screen from being formed on the top of the cell barrier, as shown in FIG.
The phosphor paste is filled by screen printing using a screen plate M having an opening smaller than the opening area of the cell space defined by the cell barrier 3 (smaller in the case of a stripe). At this time, the screen version M
Is filled with the paste, so that the paste P adheres to the back side (portion indicated by A) of the protruding portion of the screen plate M as shown in FIG. It is necessary to perform back wiping in a complicated manner. This makes it difficult to respond to automation.

As another method for forming a reflective phosphor screen, there is a photolithography method using a photosensitive phosphor paste. In this method, a step of coating a photosensitive phosphor paste with a solid color from above a cell barrier and drying the same, and a step of performing exposure and development to leave the phosphor paste in a predetermined cell space are performed in a required number of colors. After the repetition, the phosphor screen is completed through a firing step. In this method, exposure is performed via a photomask above the application surface. However, when the substrate size is large, it is difficult to control the size of the photomask to be used, and the phosphor remains above the cell barrier. Problems arise.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide an AC type PDP.
In forming a phosphor screen by a photolithography method in the manufacturing process, while stabilizing the drive after the panelization by preventing the phosphor from remaining on the top of the cell barrier,
An object of the present invention is to provide a method for forming a fluorescent screen of an AC PDP with high production efficiency.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a front panel having a composite electrode comprising a sustain electrode and a bus electrode, and a rear panel having an address electrode orthogonal to the composite electrode. A method of forming a fluorescent screen in an AC-type PDP, comprising: a cell barrier provided between the address electrodes, wherein the fluorescent screen is formed over a wall surface and a bottom surface of the cell barrier. After repeating the step of coating the body paste at least in the cell space and drying, and the step of performing back exposure and development to leave the phosphor paste layer in the predetermined cell space by the required number of colors, through a firing step The feature is to complete the phosphor screen.

At present, Ag is used as the material of the address electrode, and the electrode itself does not transmit light. However, since there is a gap between the cell barrier and the address electrode, light is irradiated from there to perform exposure. To do. Since the phosphor is white and scatters light, there is no problem if the phosphor is overly illuminated. If the address electrode is a transparent electrode, back exposure can be performed reliably. When a dielectric layer is provided to cover the address electrodes on the back plate, the dielectric layer is preferably formed of a material that transmits light as much as possible. Specifically, the dielectric layer is formed of a material having a light transmittance of 70% or more. Is preferably formed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, as shown in FIG. 4A, an address electrode 12 and a dielectric layer 1 covering the address electrode 12 are formed on a glass substrate 11.
3 and a cell barrier 14 is formed thereon. As a method of forming the address electrode 12, Ag is deposited on the substrate by a vacuum evaporation method, a sputtering method, a plating method, a thick film method, or the like.
There is a method of forming a film of an electrode material such as, and patterning the film by a photolithography method, and a method of patterning by screen printing using an Ag paste or the like. Although the dielectric layer 13 is not always necessary, when it is provided, a material having a light transmittance of 70% or more is used, and the entire surface is coated by screen printing or the like so as to cover the address electrodes 12. The cell barrier 14 may be formed by a method in which a barrier material paste is overprinted in a pattern by screen printing and then fired, or a barrier material paste is formed on the barrier formation layer formed by coating or transferring from the barrier material sheet. A method in which a mask having a sandblasting property is formed, and an unnecessary portion of the barrier forming layer is removed by performing sandblasting through the mask, followed by baking, and a barrier material is formed in a female space formed by a resist or the like. A typical method is to fill the paste and remove the female mold before firing. The barrier material paste used in these methods is preferably made of glass frit, filler, white pigment, binder resin, or the like, and has light scattering properties.

When the address electrode 12 is a transparent electrode, ITO, ZnO or SnO ₂ can be used as the material. However, the dielectric layer 13 and the cell barrier 14
There is a sintering step at the time of formation, the film produced by a vacuum deposition method such as vapor deposition or sputtering, there is a risk of disconnection due to the difference in coefficient of thermal expansion at this time, a film produced by a thick film formation method is preferable, for example, binder resin A paste obtained by printing a paste in which a transparent conductive powder is dispersed or formed by a sol-gel method is used, and particularly preferably, a functional group similar to an indium compound having a functional group or site that reacts to light is used. Alternatively, it is desirable to use a composition for forming a transparent conductive film containing a tin compound having a site and a medium as an electrode material, since the composition further has photosensitivity.

Examples of the indium compound having a functional group or site that reacts to light and the tin compound having a similar functional group or site that constitute the composition for forming a transparent conductive film include indium formate, indium acetate, and the like. Indium oxalate, indium nitrate, organic or inorganic salts of indium such as indium chloride, tin formate, tin acetate, tin oxalate, tin nitrate, organic or inorganic salts of tin such as tin chloride, indium methoxide, indium ethoxide, It is obtained by reacting an indium alkoxide such as indium propoxide or indium butoxide, or a tin alkoxide such as tin methoxide, tin ethoxide, tin propoxide or tin butoxide with an organic substance which forms a chelate with these metals.

Examples of the organic compound which forms a chelate with these metals and reacts with light include acetylacetone, benzoyltrifluoroacetone, pivaloyltrifluoroacetone, methyl acetoacetate, ethyl acetoacetate, phenolacetoacetate, benzoic acid , Naphthol, naphthoic acid and the like.

The reaction of the above-mentioned indium compound or tin compound with the above-mentioned chelate-forming compound is carried out, for example, in the case where alkoxide is used as the indium compound and acetylacetone is used as the chelate-forming compound. In (OR) _n + xCH ₃ COCH ₂ COCH ₃ → In
(OR) _nx (OC (CH ₃ ) = CHCOCH ₃ ) _x +
ROH (R is an alkyl group of an alkoxide group, and n is a valence of indium)

As the indium compound and tin compound having a functional group or site that reacts with light, it is sufficient that at least one bond of a metal atom is bonded to a functional group or site that reacts with light. May be in a salt state. Note that a functional group or site that reacts with light means a functional group or site that absorbs light of 450 nm or less.

The indium compound and the tin compound are preferably used in a ratio of indium to tin of 0.01 to 0.20 tin per atom of indium in terms of atomic ratio of indium to tin. If the amount of tin used is insufficient, the carrier density will be low, and the conductivity of the film to be formed will be insufficient, etc., and on the other hand, if the amount of tin used is too large,
It is insufficient in that the carrier mobility is lowered and the conductivity of the formed film is deteriorated.

The composition for forming a transparent conductive film is prepared by dissolving or dispersing the above essential components in a liquid medium. Examples of the liquid medium include water, an organic solvent, and a mixture thereof. Examples of the organic solvent include alcohols such as methanol, ethanol, and isopropyl alcohol, acetates such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone, and diethyl ketone. And ketones such as acetylacetone, ethers such as methoxyethanol and ethoxyethanol, ethers such as dioxane and tetrahydrofuran, and aromatics such as toluene and xylene.

The type and composition of the liquid medium are selected and used according to the types of indium compound and tin compound used. For example, when the indium compound and tin compound having a functional group or site that reacts to light to be used are water-soluble or hydrophilic, such as when they have a partial salt form, water or water is used as a liquid medium. A mixture of water and an organic solvent may be used, and if necessary, the salt may be neutralized to form a hydroxyl group. In addition, when the indium compound and tin compound having a functional group or site that reacts to light used are highly organic and soluble in an organic solvent,
It is preferable to use an organic solvent or a mixture of an organic solvent and water as the liquid medium.

The amount of the liquid medium varies depending on the type of the indium compound, the tin compound and the type of the thermally decomposable resin to be used, if necessary. Preferably, it is used in an amount of up to 20% by weight. If the amount of the liquid medium is insufficient, the coating performance is deteriorated, and the obtained coating film is insufficient in that cloudiness and cracks are generated. The thickness of the ITO film obtained by baking the film is small, and defects in the coating film are liable to occur, and the desired conductivity is not easily obtained.

It is preferable to include a thermally decomposable resin binder for the purpose of imparting coatability to the composition. Examples of such a resin binder include methyl cellulose, ethyl cellulose, acetyl cellulose, acetyl ethyl cellulose, hydroxypropyl cellulose, benzyl cellulose, nitrocellulose, and the like. The amount of the resin binder used is 10 per 10 parts by weight of the total of the indium compound and the tin compound.
It is preferably used in a proportion of up to 1,000 parts by weight. If the amount of the heat-decomposable resin is insufficient, the composition is insufficient in terms of coatability and the like, while if the amount of the heat-decomposable resin is too large, it is obtained by firing after patterning the coating film. ITO
It is not preferable in that the quality of the film is deteriorated and the electrical characteristics become insufficient.

The composition for forming a transparent conductive film can be easily obtained by simply mixing the above components. Further, an additive such as a sensitizer may be included as needed. The composition for forming a transparent conductive film obtained as described above may be prepared in a concentrated state, and may be used after adding a liquid medium immediately before use to impart coating suitability. When storing, it is preferable to store in a cool and dark place.

In order to form an address electrode using the above composition for forming a transparent conductive film, the composition is applied to a glass substrate, dried, exposed to a pattern, and the unexposed portion is developed and removed, followed by heat treatment. I do.

The coating method of the composition may be any of known coating methods such as a screen printing method, a roll coating method, a dip coating method and a spin coating method. Drying conditions after coating are arbitrary, but usually, a temperature that does not adversely affect the thermally decomposable resin, for example, 0.1 to 100 ° C. to 200 ° C.
About 1 hour. The coating formed in this way is opaque and almost insulating.

Next, a negative photomask having a desired pattern is brought into close contact with the film thus formed and exposed. Radiation used for exposure is generally light having a wavelength of about 200 to 500 nm, and for example, a high-pressure mercury lamp or the like can be used as a light source. By this exposure, the indium compound and the tin compound having a functional group or site that reacts to the light in the exposed portion react with the light, causing a change in physical properties of the film, and the film becomes insoluble in the developer. Therefore, the exposed film is coated with a developing solution over the entire surface, or the exposed film is immersed in the developing solution and, if necessary, the surface is rubbed (brushed) to peel off the unexposed portion of the film, A negative image is formed.

Subsequently, the negative image is subjected to a heat treatment. The functional group, site and binder resin (if present) remaining in the coating are decomposed and vaporized by this heat treatment, while the indium compound and the tin compound are converted into a composite oxide (ITO), which is transparent to the patterned coating. Properties and conductivity. Preferred heating conditions for such treatment are from about 400 to 550 ° C for about 0.1 to 1.0 hour. If the heating conditions are too mild, it is insufficient in that thermal decomposition and crystallization do not proceed sufficiently, while if the heating conditions are too severe, the effect on the substrate is large and the oxidation of ITO itself proceeds more than necessary. In addition, it is not preferable in that it is insufficient to secure oxygen deficiency necessary for expressing conductivity.

Referring back to FIG. 4, after forming up to the cell barrier 14 on the glass substrate 11, as shown in FIG. 4B, the photosensitive phosphor paste of the first color (for example, G color) is used. After coating, a phosphor paste layer 16 depressed at the center of the cell space as shown in FIG.
To form In order to coat the phosphor paste with a solid, screen printing (solid printing) may be used,
Alternatively, a coating device of a blade coater or a die coater may be used. Also, rough printing may be performed by screen printing through a screen plate having an opening larger than the desired cell space. This is more effective because the amount of phosphor paste used can be reduced.

Next, as shown in FIG. 5A, back exposure is performed from the back side of the glass substrate 11 via the photomask 17. When the address electrode 12 is a transparent electrode, light passes therethrough, so that there is no problem in exposing the phosphor paste layer 16. Light is radiated from the gap, and the phosphor itself scatters light to expose. Therefore, light is radiated slightly. In this case, FIG.
As shown in (a), if the opening 17a of the photomask 17 matches the width inside the cell barrier 14, there is no problem in exposing the phosphor paste layer 16 in the desired cell space. But,
As shown in FIG. 6B, the opening 17a of the photomask 17 is formed.
Is equal to the outer width of the cell barrier 14, the exposure light can be said to be parallel, but is scattered and exposed to the phosphor paste layer in the adjacent cell space.
a needs to be inside. When the address electrode 12 is a transparent electrode, the opening 17a of the photomask 17 may be reduced to the size of the electrode as shown in FIG. That is, even if the opening 17a is small, the phosphor paste in the desired cell space is exposed by scattering by the phosphor itself and the cell barrier 14. And opening 17a like this
Has the advantage that the alignment of the photomask 17 is facilitated.

After the rear exposure, a phosphor paste layer 16 (G) is left in a predetermined cell space through a developing step as shown in FIG. 5B. The coating process, the exposure process, and the development process of the photosensitive phosphor paste are repeated for a predetermined number of colors (normally, three colors of G, B, and R).
As shown in (c), the phosphor paste layers 16 (G), 16 (B), 16 (R) of each color are distributed in the cell space.
Finally, the organic matter in the phosphor paste layer 16 is burned off in a baking step, and as shown in FIG.
A back plate is obtained in which (G), 17 (B) and 17 (R) are each patterned in a predetermined cell space.

As the photosensitive phosphor paste, one obtained by kneading an organic polymer conjugate, a photopolymerizable monomer, a photopolymerization initiator, a phosphor powder, and an organic solvent is used.

As the organic polymer conjugate, in order to enable water development, it is preferable to select an organic polymer conjugate which shows solubility or dispersibility in water when the composition is formed into a film. As such, hydroxypropylcellulose is excellent in solubility in a solvent and developability. The molecular weight of the organic polymer conjugate is preferably in the range of 10,000 to 2,000,000, and more preferably 30,000 to 100,000.If it is less than 10,000, the adhesion to the substrate is reduced, and 2,000,00
If it exceeds 0, it is not preferable because it becomes difficult to thermally decompose and remove the organic polymer conjugate during firing.

Examples of the photopolymerizable monomer include polyethylene glycol such as diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, and tetraethylene glycol dimethacrylate, and polypropylene glycol. Such as diacrylates or dimethacrylates of polyalkylene glycols, pentaerythritol trimethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 2,2-dimethylpropane diacrylate, 2,2-dimethylpropane dimethacrylate Or the like can be mentioned the door. One or two or more of these can be selected and used by mixing.

As the photopolymerization initiator, 2-benzyl-2
-Dimethylamino-1- (4-morpholinophenyl)-
In addition to using at least 50% by weight of butan-1-one, anthraquinones such as ethylanthraquinone, benzanthraquinone and diaminoanthraquinone; benzophenones such as benzophenone and 4,4-bis (dimethylamino) benzophenone; isobutylbenzoin ether; Benzoin ethers such as benzoin ether, benzoin ethyl ether and benzoin methyl ether, 2,4-diethylthioxanthone,
Thioxanthones such as 2-chlorothioxanthone,
2,2-dimethoxy-2-phenylacetophenone, 1
-Hydroxycyclohexyl phenyl ketone, 1,1-
Dichloroacetophenone can be used in combination.
These can be used alone or in combination of two or more.

As a phosphor powder having a red emission color, Y ₂ O
₃ : Eu, Y ₂ SiO ₅ : Eu, Y ₃ Al ₅ O ₁₂ : E
u, Zn ₃ (PO ₄ ) ₂ : Mn, YBO ₃ : Eu,
(Y, Gd) BO ₃ : Eu, GdBO ₃ : Eu, ScB
O ₃ : Eu, LuBO ₃ : Eu, etc. are exemplified, and the phosphor powder emitting green light is Zn ₂ SiO ₄ : Mn, Ba.
Al ₁₂ O ₁₉ : Mn, SrAl ₁₃ O ₁₉ : Mn, CaAl ₁₂
O ₁₉ : Mn, YBO ₃ : Tb, BaMgAl ₁₄ O ₂₃ : M
n, LuBO ₃ : Tb, GdBO ₃ : Tb, ScB
O ₃ : Tb, Sr ₆ Si ₃ O ₃ Cl ₄ : Eu, etc. are exemplified. As the phosphor powder having a blue emission color, Y ₂ SiO ₅ :
Ce, CaWO ₄ : Pb, BaMgAl ₁₀ O ₁₇ : Eu,
BaMgAl ₁₄ O ₂₃ : Eu is exemplified.

Examples of the organic solvent include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether,
Diethylene glycol monomethyl ether acetate,
Diethylene glycol monoethyl ether acetate,
Ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol,
Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether acetate, 3-methyl-3
-Methoxybutanol, methoxybutyl acetate, terionone and the like. These can be used alone or in combination of two or more. Among these organic solvents, 3-methyl-3-methoxybutanol can be particularly mentioned as one that gives long-term stability of the photosensitive phosphor paste. When a solvent having a high evaporation rate, such as water, is used instead of these organic solvents, the drying rate is high, so that traces of a screen mesh remain on the surface of the applied photosensitive phosphor paste layer with irregularities. Or
It is preferable to select and use an organic solvent having a low evaporation rate because it causes clogging of the screen mesh. Therefore, as an organic solvent used for the photosensitive phosphor paste, the evaporation amount of butyl acetate per unit time is 1
It is desirable that the specific evaporation rate when it is set to 00 is 25 or less.

The mixing ratio of the photosensitive phosphor paste is 3 parts by weight of the photopolymerizable monomer per 100 parts by weight of the organic polymer conjugate.
The photopolymerization initiator must be used in an amount of 0 to 200 parts by weight, preferably 30 to 120 parts by weight, and 0.01 to 25 parts by weight, more preferably 0.1 to 15 parts by weight, based on the total composition. The organic solvent is 250 to 700 parts by weight, preferably 300 to 500 parts by weight, based on 100 parts by weight of the organic polymer conjugate.
The weight of the phosphor powder is 100 to 150 parts by weight based on 100 parts by weight of the total amount of the organic polymer conjugate, the photopolymerizable monomer, the photopolymerization initiator and the organic solvent.

When the amount of the photopolymerizable monomer is less than 30 parts by weight, the photocuring is insufficient, the image portion is eluted during development, and an image cannot be formed, and the light emission characteristics are deteriorated. If the amount exceeds 200 parts by weight, the resolution of a fine image is reduced, and sticking is likely to occur.

When the amount of the photopolymerizable initiator is less than 0.01 part by weight, the photocuring at a normal exposure amount is insufficient, so that the image is eluted during development and an image cannot be formed. When the photopolymerization initiator is used in excess of 25 parts by weight due to low solubility in the solvent, the photopolymerization initiator is in a non-uniformly dispersed state when the composition is used as a film, and a fine image is formed. Not only is it not possible, but it also undesirably reduces light transmittance. The 2-benzyl-2-ditylamino-1- (4-morpholinophenyl) -butane-1
The purpose of the present invention is not achieved unless at least 50% by weight of -one is used in the photopolymerization initiator.

If the amount of the phosphor powder is less than 100 parts by weight, not only sufficient light emission characteristics cannot be obtained, but also sufficient strength cannot be maintained upon firing. If the amount exceeds 150 parts by weight, the UV absorption by the phosphor becomes excessively large, and the action of the photopolymerization initiator is hindered.

When the amount of the organic solvent is less than 250 parts by weight, the viscosity when the photosensitive phosphor paste composition is prepared becomes too high to form a phosphor film. On the other hand, when the amount exceeds 700 parts by weight, the viscosity becomes too low and the phosphor in the photosensitive phosphor paste composition precipitates and separates, which is not preferable.

The viscosity of the photosensitive phosphor paste composition obtained by kneading these components at 25 ° C. is in the range of 50 to 4,000 P, particularly 200 to 2,000 P.
It is preferably in the range of 00P. If it is less than 50P, the phosphor in the photosensitive phosphor paste composition sediments and separates, which is not preferable.
The film cannot be formed because the viscosity is too high.

The photosensitive phosphor paste may further contain, if necessary, a thermal polymerization inhibitor such as hydroquinone, t-butylhydroquinone, benzoquinone, or catechol, a dye or pigment for visualization, and an antifoaming agent. Can also.

[0042]

First, address electrodes were formed on a glass substrate serving as a back plate. Specifically, 10.27 parts by weight of indium nitrate, 0.33 parts by weight of stannous oxalate, and 15 parts by weight of an organic chelating agent (chemical name: acetylacetone)
And 10 parts by weight of a resin binder (chemical name: ethylcellulose, trade name: Dow Chemical Co., Ltd. “Ethocel STD-
100 ") was added to ethyl cellosolve, stirred at room temperature to dissolve, and further filtered to remove insolubles, thereby producing a transparent conductive film forming composition having a solid content of 15%. The material was uniformly applied by a roll coating method, dried at 150 ° C. for 10 minutes, irradiated with ultraviolet rays (wavelength: 300 nm) through a photomask, and then immersed in a hydrochloric acid etching solution for development. After the development step, the patterned substrate was baked at 500 ° C. for 60 minutes in air to form a transparent address electrode made of ITO.

After forming an address electrode on a glass substrate, a dielectric layer having high light transmittance was formed to cover the address electrode.
Specifically, "PLS" made by NEC Glass was added to the glass paste.
-3162S "was used. Then, this paste is applied on a substrate by screen printing, and after printing, leveling is performed at room temperature for 10 minutes to obtain a smooth surface.
Drying was performed at 100 ° C. for 15 minutes. Furthermore, baking was performed at 580 ° C. for 60 minutes in a belt furnace to decompose organic substances contained in the dried coating film. The light transmittance of the dielectric layer thus obtained was 85%.

After forming a dielectric layer covering the address electrodes, a cell barrier was formed on the dielectric layer. here,
A barrier material paste having the following composition is applied with a blade coater to a thickness of 420 μm, and dried at 150 ° C. for 50 minutes to form a barrier formation layer having a thickness of 180 μm. Then, the barrier formation layer is sandblasted to remove unnecessary portions. The removal formed a cell barrier.

<Composition of Barrier Material Paste> Glass powder: 60 parts by weight “MB-008” manufactured by Matsunami Glass Industry Filler: 10 parts by weight “α-alumina RA-40” manufactured by Iwatani Chemical Industry Binder: “Ethocel” manufactured by Dow Corning STD100 "2 parts by weight Pigment: TiO ₂ 10 parts by weight Solvent: terpineol 18 parts by weight

The sand blast treatment of the barrier forming layer was performed as follows. First, the substrate is heated to 80 ° C., and a dry film resist (“NCP225” manufactured by Nippon Synthetic Chemical Industry) is laminated on the barrier forming layer.
Exposure was performed using ultraviolet rays through a line pattern mask having a pitch of 150 μm and a pitch of 150 μm. Exposure conditions are as follows: when measured at 364 nm, intensity 200 μW / cm ² , irradiation amount 120 m
J / cm ² . After exposure, spray development was performed with a 1 wt% aqueous solution of sodium carbonate at a liquid temperature of 30 ° C. to obtain a line width of 50
A sand blast mask having a pitch of 150 μm was formed. Then, unnecessary portions of the barrier forming layer were removed by performing sandblasting through the sandblasting mask. Specifically, alumina # 800 was used as the abrasive, the abrasive injection amount was 100 g / min, the injection pressure was 3 kgf / cm ² , and the distance between the substrate and the nozzle was 100 m.
Sand blasting was performed under the conditions of m and scan speed of 10 mm / sec. After the completion of the sand blasting treatment, the resist was removed by spraying at 30 ° C. using a 2 wt% aqueous solution of sodium hydroxide. Thereafter, baking was performed under the conditions of a peak temperature of 570 ° C. and a holding time of 20 minutes to form a cell barrier.

The above-mentioned barrier forming layer can be formed by transferring from a barrier material sheet instead of applying a barrier material paste. Further, the cell barrier may be formed by a method other than the sandblast method. For example, a method in which a barrier material paste is overprinted in a pattern by screen printing and then fired, a barrier material paste is filled in a female mold space formed by a resist or the like, the female mold is removed, and then fired. Method, and so on.

After the cell barrier is formed on the dielectric layer in this manner, G, B, and R are formed in the cell space defined by the cell barrier.
Phosphor paste layers of each color were selectively formed.

The procedure is as follows. First, a photosensitive phosphor paste containing a phosphor powder having a green emission color is applied over the entire surface with a blade coater, dried in an oven at 80 ° C. for 1 hour, and then dried in the center of the cell space. A phosphor paste layer depressed was formed. The following were used as the photosensitive phosphor paste. That is, 510 parts by weight of a phosphor powder composed of Zn ₂ SiO ₄ : Mn (“PI-G1S” manufactured by Kasei Optonics), 100 parts by weight of hydroxypropyl cellulose having an average molecular weight of 60,000, 100 parts by weight of pentaerythritol triacrylate, 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-
ON 10 parts by weight, methylhydroquinone 0.5 part by weight, 3
A photosensitive phosphor paste prepared by kneading 300 parts by weight of -methyl-3-methoxybutanol with a three-roll mill was used. The viscosity of this composition was 1,200 P at 25 ° C. as measured with a B-type rotational viscometer.

Next, the phosphor paste layer was pattern-exposed from the back side of the substrate through a glass mask. The exposure conditions are an intensity of 200 μW / cm ² and an irradiation amount of 480 mJ / cm ² when measured at 364 nm. Next, spray development was performed using pure water at an injection pressure of 1.5 kgf / cm ² ,
After the green phosphor paste layer was left in the predetermined cell space, it was dried in an oven at 80 ° C. for 10 minutes.

The phosphor paste layers containing the phosphor powders having blue and red emission colors are also formed in the same manner, and the three color phosphors are formed in the cell space in a predetermined arrangement. A body paste layer was formed. BaMgAl ₁₀ O ₁₇ : Eu (“KX-501A” manufactured by Kasei Optonics) is used for the blue phosphor powder, and (Y, Gd) BO ₃ : Eu (“KX” manufactured by Kasei Optonics) is used for the red phosphor powder.
X-504A "), and each photosensitive phosphor paste was prepared in the same manner as in the case of the green phosphor powder.

Subsequently, the baking step at 455 ° C. for 15 minutes was used to burn off the organic components of the phosphor paste layer. As a result, it was possible to obtain a back plate in which phosphors of R, G, and B were patterned in predetermined cell spaces. By combining the rear plate on which the phosphor layer was formed and the front plate separately formed, a surface discharge type AC color PDP in which three primary colors of R, G, and B were visually recognized was produced.

[0053]

As described above, the method for forming a phosphor screen according to the present invention can be applied to the formation of a phosphor screen of an AC type PDP by a photolithography method. Since the back surface exposure is performed from the back surface, the phosphor does not remain on the top of the cell barrier unlike the case where the exposure is performed from the application surface side. Therefore, the driving after paneling is stabilized.

Further, by setting the address electrodes on the back plate to be transparent electrodes, the phosphor paste can be surely exposed by back exposure. Further, when a dielectric layer is provided, by forming the dielectric layer with a material having a high light transmittance, the phosphor paste layer can be efficiently exposed.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing an example of a configuration of an AC type plasma display panel in a state where a front plate and a back plate are separated from each other.

FIG. 2 is an explanatory diagram of a screen used when filling a cell paste with a phosphor paste by screen printing.

FIG. 3 is an explanatory view of the back of a paste during screen printing.

FIG. 4 is a first half process diagram showing a procedure for forming a reflective phosphor screen in a cell barrier by the phosphor screen forming method of the present invention.

FIG. 5 is a process chart of the latter half following FIG. 4;

FIG. 6 is an explanatory diagram of a mask used at the time of back exposure.

[Explanation of symbols]

 1, glass substrate 3 cell barrier 4 sustain electrode 5 bus electrode 6 dielectric layer 7 protective layer (MgO layer) 8 address electrode 9 dielectric layer 10 phosphor 11 glass substrate 12 address electrode 13 dielectric layer 14 cell barrier 15 photosensitive Phosphor paste 16 phosphor paste layer 17 photomask 17a opening 18 phosphor

Claims (5)

[Claims] 1. A cell comprising: a front panel having a composite electrode composed of a sustain electrode and a bus electrode; and a back panel having an address electrode orthogonal to the composite electrode and a cell barrier provided between the address electrodes. A method for forming a fluorescent screen in an AC-type plasma display panel, wherein a fluorescent screen is formed over a wall surface and a bottom surface of a barrier, wherein a photosensitive phosphor paste is coated on at least a cell space and dried. An AC type plasma display characterized by repeating a process of performing a back exposure and a development to leave a phosphor paste layer in a predetermined cell space by a required number of colors, and then completing a phosphor screen through a firing process. A method for forming a fluorescent screen of a panel. 2. The method for forming a phosphor screen of a plasma display panel according to claim 1, wherein the phosphor screen is formed with the address electrodes on the back plate being transparent electrodes. 3. The phosphor screen formation according to claim 1, wherein the phosphor screen is formed after the dielectric layer is formed of a material having a light transmittance of 70% or more covering the address electrodes of the back plate. Method. 4. A cell comprising: a front plate provided with a composite electrode including a sustain electrode and a bus electrode; and a back plate provided with an address electrode orthogonal to the composite electrode and a cell barrier erected between the address electrodes. An AC-type plasma display panel comprising a phosphor screen formed on a wall surface and a bottom surface of a barrier, wherein the address electrode is a transparent electrode. 5. The AC plasma display panel according to claim 4, wherein a dielectric layer is formed of a material having a light transmittance of 70% or more so as to cover the address electrodes on the back plate.