JP4626512B2 - Pattern formation method - Google Patents

Description

  The present invention relates to a display member such as a plasma display or a plasma addressed liquid crystal display used for a wall-mounted television or a large monitor, and a method for manufacturing the display. In particular, the present invention relates to a display manufacturing method that improves yield and production efficiency in display member manufacturing. Regarding the method.

  Plasma display panels (hereinafter referred to as PDP) must be thin, lightweight, and easy to increase in size. In addition, its wide viewing angle and fast response speed compared to liquid crystal panels has made it popular in OA equipment and public information display devices, and has expanded its market especially in the field of high-definition television. The PDP generates a plasma discharge between a counter anode and a cathode electrode in a discharge space provided between a front glass substrate and a rear glass substrate, and generates ultraviolet rays generated from a gas sealed in the discharge space. Is displayed by hitting a phosphor placed in the discharge space. In this case, barrier ribs (also referred to as barriers or ribs) are provided in order to suppress the spread of the discharge to a certain area and perform display in a prescribed cell, while ensuring a uniform discharge space. The shape of this partition wall is approximately 30 to 80 μm in width and 100 to 200 μm in height, and this partition wall is usually coated with a photosensitive glass paste made of glass on a front glass substrate or a back glass substrate, dried, exposed, It is formed through development and baking.

The photosensitive glass paste used here generally uses a polymer or oligomer as a photosensitive component, and these have a property of absorbing moisture, and the moisture absorption amount is sensitive to light and has a pattern forming property ( For example, see Patent Documents 1 and 2).
JP 2000-298352 A JP 2003-5360 A

  For this reason, when the photosensitive glass paste is applied and exposed without being left for a certain period of time after drying, there is a problem that the pattern formability varies depending on the moisture absorption amount of the paste coating film. In order to solve this problem, variations in pattern formability were reduced by providing exposure after providing a standing time (hereinafter referred to as aging time) of a certain time or more until the water absorption amount of the coating film reaches saturation after coating and drying. However, since exposure is performed with an aging time of one day or longer, there is a new problem that the lead time becomes long. Under such circumstances, the present inventor has conducted research to develop a technique for shortening the aging time, and as a result, has found that immediately after the heating and drying process, the weight change of moisture is small and the variation in width is small. However, since this stable region is short, it is difficult to introduce it into the production process. Therefore, the purpose of the present invention is to widen the stable region with small variation in width and to significantly reduce the lead time compared to the conventional method. It came to be completed.

  That is, an object of the present invention is to provide a display member manufacturing method and a display in which variations in pattern formability in the exposure process as described above are suppressed and lead times are shortened.

  In order to solve the above-described problems, a method for manufacturing a plasma display member of the present invention has the following configuration.

  In the pattern forming method in which the following steps (A), (B), (D), and (E) are performed in this order, the step (C) is obtained in the heat drying step between the step (B) and the step (D). A pattern forming method comprising: a dehumidifying step of dehumidifying the obtained coating film in a humidity atmosphere of 25% RH or less.

(A) Coating step of applying a photosensitive paste containing inorganic fine particles, a photosensitive organic component and an organic solvent onto a substrate (B) Heat drying step of heating and drying the coating film obtained in the coating step (D) Exposure step of exposing the coating film obtained in the heat drying step (E) Development step of developing the coating film obtained in the exposure step

  According to the present invention, since the substrate goes through a dry humidity atmosphere in the dehumidifying step, it is possible to suppress the influence of the humidity environment, shorten the lead time, and reduce the variation in pattern formability.

  Next, a method for producing a member for a plasma display (hereinafter abbreviated as PDP) of the present invention will be described.

  The member for PDP as used in the present invention means that a layer made of an inorganic material is formed on a substrate. The layer made of an inorganic material here refers to a layer in which at least one electrode layer, dielectric layer, partition wall layer, phosphor layer, reflection layer, and the like are formed.

Hereinafter, the manufacturing method of the member for PDP of this invention is demonstrated along the manufacturing procedure represented.
As a substrate used in the method for producing a PDP member of the present invention, “PD200” manufactured by Asahi Glass Co., Ltd. and “PP8” manufactured by Nippon Electric Glass Co., Ltd., which are heat-resistant glass for PDP, can be used in addition to soda glass. .

  Next, an electrode layer is formed of a metal such as silver, aluminum, chromium, or nickel as an inorganic material on the glass substrate. As a forming method, a metal paste mainly composed of these metal powders and an organic binder is subjected to pattern printing by screen printing, or a photosensitive metal paste using a photosensitive organic component as an organic binder is screen printed. After coating, a photosensitive paste method can be used in which pattern exposure is performed using a photomask, unnecessary portions are dissolved and removed in a development step, and further, heated and baked at 400 to 600 ° C. to form a metal pattern. .

  1-10 micrometers is preferable and, as for the electrode thickness formed, 2-5 micrometers is more preferable. If the electrode thickness is too thin, the resistance value tends to be large and accurate driving tends to be difficult. If it is too thick, a large amount of material is required, which tends to be disadvantageous in terms of cost. The width of the electrode pattern is preferably 20 to 200 μm, more preferably 30 to 100 μm. If the width of the electrode pattern is too thin, the resistance value tends to be high and accurate driving tends to be difficult, and if it is too thick, the distance between adjacent electrodes tends to be small, so that a short defect tends to occur.

  A dielectric layer is then preferably formed. In the present invention, the dielectric layer uses glass powder as an inorganic material, and a glass paste mixed with an organic binder is applied by screen printing so as to cover the electrode layer, and then fired at 400 to 600 ° C. Can be formed. Glass powder containing at least one of lead oxide, bismuth oxide, zinc oxide and phosphorus oxide as a component of glass powder, which is an inorganic material used for the dielectric layer, and containing 10 to 80% by weight in total. Can be preferably used. By setting it as 10 weight% or more, baking at 600 degrees C or less becomes easy, and setting it as 80 weight% or less prevents crystallization and the fall of the transmittance | permeability. A paste can be prepared by kneading these glass powder and an organic binder. As the organic binder to be used, cellulose compounds typified by ethyl cellulose, methyl cellulose and the like, acrylic compounds such as methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methyl acrylate, ethyl acrylate and isobutyl acrylate can be used. Moreover, you may add additives, such as a solvent and a plasticizer, in glass paste. As the solvent, general-purpose solvents such as terpineol, butyrolactone, toluene and methyl cellosolve can be used. As the plasticizer, dibutyl phthalate, diethyl phthalate, or the like can be used. By adding a filler component in addition to the glass powder, a PDP having a high reflectance and a high luminance can be obtained. As the filler, titanium oxide, aluminum oxide, zirconium oxide and the like are preferable, and it is particularly preferable to use titanium oxide having a particle diameter of 0.05 to 3 μm. The filler content is preferably a glass powder: filler ratio of 1: 1 to 10: 1. The brightness improvement effect can be obtained by setting the filler content to 1/10 or more of the glass powder.

  The thickness of the dielectric layer is preferably 3 to 30 μm, more preferably 3 to 15 μm. If the thickness of the dielectric layer is too thin, pinholes tend to occur frequently, and if it is too thick, the discharge voltage tends to be high and the power consumption tends to increase.

  Furthermore, when the method for manufacturing a PDP member of the present invention is applied to a PDP back plate, barrier ribs for partitioning discharge cells are formed on the dielectric layer.

  The height of the partition wall is suitably 80 μm to 200 μm. By setting the thickness to 80 μm or more, the phosphor and the scan electrode can be prevented from being too close to each other, and the phosphor can be prevented from being deteriorated by discharge. Further, by setting the thickness to 200 μm or less, the distance between the discharge at the scan electrode and the phosphor can be reduced, and sufficient luminance can be obtained. The partition pitch (P) is often 100 μm ≦ P ≦ 500 μm. In the high-definition plasma display, the partition pitch (P) is 100 μm ≦ P ≦ 250 μm. By setting the thickness to 100 μm or more, the discharge space can be widened and sufficient luminance can be obtained, and by setting the thickness to 500 μm or less, a fine image with fine pixels can be displayed. By setting the thickness to 300 μm or less, it is possible to display a beautiful video of HDTV (high definition) level. The line width (L) is preferably 10 μm ≦ L ≦ 50 μm in half width. By setting the thickness to 10 μm or more, strength can be maintained, and damage can be prevented from occurring when the front plate and the back plate are sealed. Further, when the thickness is 50 μm or less, the formation area of the phosphor can be increased and high luminance can be obtained.

  Such partition walls are formed by baking after forming a pattern using a photosensitive paste made of an organic component containing inorganic fine particles and a photosensitive component.

  As the inorganic material of the photosensitive paste in the present invention, glass, ceramic (alumina, cordierite, etc.) and the like can be used. In particular, glass or ceramics containing silicon oxide, boron oxide, or aluminum oxide as an essential component is preferable.

The particle diameter of the inorganic material is selected in consideration of the shape of the pattern to be produced, but the volume average particle diameter (D50) is preferably 1 to 10 μm, and more preferably 1 to 5 μm. By setting D50 to 10 μm or less, it is possible to prevent surface irregularities from occurring. Moreover, the viscosity adjustment of a paste can be made easy by setting it as 1 micrometer or more. Further, it is particularly preferable in the pattern formation to use glass fine particles having a specific surface area of 0.2 to ³ m ² / g.

  Since the partition walls are preferably patterned on a glass substrate having a low heat softening point, it is preferable to use inorganic fine particles containing 60% by weight or more of glass fine particles having a heat softening temperature of 350 ° C. to 600 ° C. as the inorganic fine particles. Further, by adding glass fine particles or ceramic fine particles having a heat softening temperature of 600 ° C. or higher, the shrinkage ratio during firing can be suppressed, but the amount is preferably 40% by weight or less.

As the glass powder to be used, a glass having a linear expansion coefficient of 50 × 10 ^{−7 to} 90 × 10 ⁻⁷ , or 60 × 10 ^{−7 to} 90 × 10 ⁻⁷ in order to prevent warping of the glass substrate during firing. It is preferable to use fine particles.

  As a material for forming the partition wall, a glass material containing an oxide of silicon and / or boron is preferably used.

  Furthermore, by containing at least one of bismuth oxide, lead oxide, and zinc oxide in a total amount of 5 to 50% by weight, a glass paste having temperature characteristics suitable for patterning on a glass substrate can be obtained. it can. In particular, when glass fine particles containing 5 to 50% by weight of bismuth oxide are used, advantages such as a long pot life of the paste can be obtained.

  Moreover, you may use the glass fine particle which contains 3-20 weight% of at least 1 sort (s) among lithium oxide, sodium oxide, and potassium oxide.

  In addition, if glass fine particles containing both metal oxides such as lead oxide, bismuth oxide and zinc oxide and alkali metal oxides such as lithium oxide, sodium oxide and potassium oxide are used, with a lower alkali content, The thermal softening temperature and linear expansion coefficient can be easily controlled.

  The organic component including the photosensitive component preferably contains a photosensitive component selected from at least one of a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer, and, if necessary, photopolymerization. An initiator, a light absorber, a sensitizer, an organic solvent, a sensitization aid, and a polymerization inhibitor are added.

  The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond, and specific examples thereof include monofunctional and polyfunctional (meth) acrylates, vinyl compounds, allyl compounds, and the like. be able to. These can be used alone or in combination of two or more.

As more specific examples of the photosensitive monomer, monofunctional and polyfunctional (meth) acrylates, vinyl compounds, allyl compounds, and the like can be used. These can be used alone or in combination of two or more. As the (meth) acrylate compound, an acrylic compound or a methacrylic compound having an alkyl group represented by the chemical formulas (1), (2), (3), and (4) is preferably used.
CH ₂ = CR ³ COO-R ⁴ (1)
CH ₂ = CR ³ COO-R ⁴ -OCOCHR ¹ = CH ₂ (2)
CH ₂ = CR ³ COO-R ⁵ -OCO-R ⁶ -COO-R ⁵ -OCOCHR ³ = CH ₂ (3)
(CH ₂ = CR ³ COO- (CH ₂ CHR ⁶ O) _m ) _n -R ⁷ (4)
Here, R ³ and R ⁶ are hydrogen, a methyl group or a methylene group, R ⁴ is an alkyl group or alkylene group having 1 to 20 carbon atoms, R ⁵ is a hydroxyalkylene group having 3 or more carbon atoms, and R ⁷ is 1 carbon atom. -20 alkyl group, aryl group, aralkyl group, m is an integer of 0-30, and n is an integer of 3-6. However, the monomer used here is not limited to these.

  As the photosensitive oligomer and photosensitive polymer, an oligomer or polymer obtained by polymerizing at least one of compounds having a carbon-carbon double bond can be used. By copolymerizing an unsaturated acid such as an unsaturated carboxylic acid with a polymer or oligomer, the developability after exposure can be improved.

  Specific examples of the photopolymerization initiator include benzophenone, methyl O-benzoylbenzoate, 4,4-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, 4,4-dichlorobenzophenone, 4- Examples include benzoyl-4-methylphenyl ketone, dibenzyl ketone, fluorenone, 2,3-diethoxyacetophenone, 2,2-dimethoxy-2-phenyl-2-phenylacetophenone, and the like. One or more of these can be used. The photopolymerization initiator is preferably added in the range of 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, based on the photosensitive component. If the amount of the polymerization initiator is too small, the photosensitivity tends to decrease, and if the amount of the photopolymerization initiator is too large, the residual ratio of the exposed portion tends to be too small.

  It is also effective to add a light absorber. By adding a compound having a high absorption effect of ultraviolet light or visible light, a high aspect ratio, high definition, and high resolution can be obtained. As the light absorber, an organic dye is preferably used. Specifically, an azo dye, an aminoketone dye, a xanthene dye, a quinoline dye, an anthraquinone dye, a benzophenone dye, a diphenylcyanoacrylate dye. Dyes, triazine dyes, p-aminobenzoic acid dyes, and the like can be used.

  A sensitizer is added in order to improve sensitivity. Specific examples of the sensitizer include 2,4-diethylthioxanthone, isopropylthioxanthone, 2,3-bis (4-diethylaminobenzal) cyclopentanone, 2,6-bis (4-dimethylaminobenzal) cyclohexanone, and the like. Is mentioned. One or more of these can be used.

Examples of the organic solvent include methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether acetate, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, and γ-butyllactone. , N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid and the like, and one or more of these An organic solvent mixture is used.
The photosensitive paste is usually prepared by mixing the above-mentioned inorganic fine particles and organic components so as to have a predetermined composition, and then uniformly mixing and dispersing them with a three roller or kneader.

  In forming the partition walls, a photosensitive paste is applied on the substrate on which the electrodes are formed or on the dielectric layer. As a coating method, a screen printing method, a bar coder, a roll coater, a direct coater, a blade coater, or the like can be used. The coating thickness can be adjusted by selecting the number of coatings, screen mesh, and paste viscosity. The film thickness is effective when the film thickness is 15 μm or more. When the thickness is 15 μm or more, variation in pattern formability due to aging time increases, and thus the present invention can be used effectively. When the film thickness is less than 15 μm, the variation in the width due to the environment is small, and the effectiveness of the present invention is not noticeable. The present invention is also applied when the coating process, the heat drying process, the dehumidification process, and the exposure process are performed a plurality of times, and is effective when the total coating thickness before each exposure is 15 μm or more. The drying temperature in the heating and drying step after the partition wall application is 60 ° C to 150 ° C, more preferably 90 ° C to 110 ° C. The purpose of this heat-drying process is to remove the solvent. If the drying temperature is too low or too high, the film may be deteriorated due to insufficient drying or over-drying, causing deterioration in pattern formation. It becomes. By setting the drying temperature to 60 ° C. to 150 ° C., it is possible to effectively remove the solvent and obtain good pattern formability.

  Next, the dehumidifying step after the photosensitive paste application step and the heat drying step in the present invention will be described. In the pattern formation method of this invention, after apply | coating the photosensitive paste in an application | coating process, after passing through the heat drying process which heat-drys using a ventilation oven, a hotplate, IR furnace, etc., it progresses to a dehumidification process. Here, the dehumidifying step refers to a step in which the photosensitive paste coated substrate unloaded from the drying furnace after the heating and drying step passes through a dry atmosphere of 25% or less of the environment.

  In the first aspect of the dehumidifying step in the present invention, a photosensitive paste-coated dry substrate that is unloaded from the drying furnace after the heat-drying step and has an installation time in an atmosphere of 25% RH or more within one hour, 25 After the dehumidification process installed in a dry atmosphere of% RH or less, the process proceeds to the exposure process. When installed in an atmosphere of 25% RH or more for 1 hour or longer, it is affected by the surrounding moisture absorption, and there is a large variation in the partition wall width between the exposed and developed substrates depending on the surrounding environment.

  In order to further develop the effects of the present invention, it is preferable to have a dehumidification step immediately after the heat drying step and to have an exposure step immediately after the dehumidification step. The term “immediately” as used herein refers most preferably to the form in which the heating dryer in the heating drying process and the exposure machine in the exposure process are connected by dehumidification in the dehumidification process as shown in FIG. In a state where it can be installed in a dry atmosphere using a transfer device or the like within one hour.

  As the drying atmosphere environment in the dehumidification process where the photosensitive paste coated substrate carried out from the drying furnace after the heating and drying process is installed, it is left in a desiccator filled with dry air or a sealed system space equivalent thereto, or an arbitrary amount All dehumidification and moisture-proof conditions such as leaving in a desiccator with a desiccant such as silica gel are applied. The humidity environment is maintained in a humidity atmosphere of 25% RH or less, more preferably 15% RH or less.

  When the environment is 25% RH or less, the influence of moisture absorption can be reduced, and the partition wall width variation between the substrates can be reduced. Furthermore, when it is 15% RH or less, the variation can be further reduced.

  In FIG. 1, which is the most preferable mode of the present invention, a dehumidification line between a drying furnace used in a heat drying process and an exposure machine is directly connected by a tunnel-shaped sealed space, and dry air is enclosed and circulated in the space. To do. By adopting such a form, it is possible to proceed to the exposure process without being influenced by the outside of the dry atmosphere, and therefore, it is possible to effectively reduce the variation in the partition wall width between the substrates after exposure and development. .

  In the dehumidifying step, the standing time in a dry atmosphere is preferably shorter as the humidity is higher. Within 50 minutes RH or less, within 20 minutes, 25% RH or less within 3 hours, and 15% RH or less within 24 hours. Preferably there is. When the standing time exceeds the above time in the atmosphere, the variation in the partition wall width between the substrates after exposure and development becomes larger than the case where the time is equal to or less than the above time.

  When it is assumed that there is a problem with the transport system and the exposure machine in the apparatus configuration as shown in FIG. 1 and there is a stagnation of the substrate in the dehumidification process, a dry atmosphere buffer space as shown in FIG. 2 is installed in the dehumidification process. Is preferred. By installing the dry atmosphere buffer space, it becomes possible to temporarily hold the stagnated substrate, and if it is within the standing time, it is possible to proceed to the exposure process after the trouble recovery, and to prevent the loss of the substrate. The dry atmosphere buffer space refers to a desiccator-like space that temporarily holds the substrate, and its size and form are preferably those where more substrates can be installed, and the humidity atmosphere is the same as the tunnel-shaped sealed space in the dehumidification process preferable.

  Further, as a second aspect of the dehumidifying step in the present invention, when the substrate installation environment after the heat drying step is 25% RH or more, or after the heat drying step, the substrate installation environment is 25% RH or less. However, if the exposure time has exceeded the above time due to trouble with the exposure apparatus, etc., after dehumidifying by heating at 60-110 ° C. for 20 minutes to 2 hours again using a ventilated oven, hot plate, IR furnace, etc. The exposure in an atmosphere of 25% RH or more is made within one hour, and the process proceeds to the exposure process. By dehumidifying the moisture-absorbed dry coating film by additional drying after the heat-drying step, the same effect as the first aspect of the present invention can be obtained, and the variation in the partition wall width between the substrates can be reduced. It becomes.

  When the heating temperature is lower than 60 ° C., dehumidification is insufficient, and when the heating temperature is higher than 110 ° C., overdrying occurs, resulting in a large variation in partition wall width. Further, when the heating time is shorter than 20 minutes, dehumidification is insufficient, and when the heating time is longer than 2 hours, it is overdried and the variation in the partition wall width becomes large. The drying equipment for heating here may be newly installed separately from the dryer used for the heating and drying process after the substrate coating, or may be installed instead of the dry atmosphere buffer space shown in FIG. .

  By performing exposure through a photomask and subsequent development after a heat drying process and a dehumidification process that satisfy the above conditions, it is possible to form a pattern with a short lead time and small shape variation.

The exposure is performed by mask exposure using a photomask, as is performed by a normal photolithography method. Examples of the active light source used at this time include visible light, near ultraviolet light, ultraviolet light, electron beam, X-ray, and laser light. Among these, ultraviolet rays are most preferable, and as the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, or a germicidal lamp can be used. Among these, an ultrahigh pressure mercury lamp is suitable. Exposure conditions vary depending on the coating thickness, but exposure is performed for 0.1 to 10 minutes using an ultrahigh pressure mercury lamp with an output of 1 to 100 mW / cm ² .

  After exposing the photosensitive paste film, development is performed using the difference in solubility in the developer between the exposed and unexposed areas. Development can be performed by a dipping method, a spray method, a brush method, or the like.

  As the developer, a solution in which an organic component to be dissolved in the photosensitive paste can be dissolved is used. When a compound having an acidic group such as a carboxyl group is present in the photosensitive paste, it can be developed with an alkaline aqueous solution. As the alkaline aqueous solution, sodium hydroxide, sodium carbonate, sodium carbonate aqueous solution, calcium hydroxide aqueous solution or the like can be used. However, it is preferable to use an organic alkaline aqueous solution because an alkaline component can be easily removed during firing. As the organic alkali, a general amine compound can be used. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, and diethanolamine. The concentration of the alkaline aqueous solution is usually 0.01 to 10% by weight, more preferably 0.1 to 5% by weight. If the alkali concentration is too low, the soluble portion tends not to be removed. If the alkali concentration is too high, the pattern portion tends to be peeled off or the insoluble portion tends to be corroded. The development temperature during development is preferably 20 to 50 ° C. in terms of process control.

  In addition to development with a developer, pattern formation by sandblasting is also possible by utilizing the difference in coating film hardness between exposed and unexposed areas. In addition, by utilizing the difference in hardness due to this exposure, the resist film formation used in the current sandblasting method, that is, resist film coating, heat drying, exposure, development, and the resist film peeling process after sandblasting are omitted. Therefore, significant cost reduction is possible.

  Next, baking is performed in a baking furnace. The firing atmosphere and temperature vary depending on the type of paste and substrate, but firing is performed in an atmosphere of air, nitrogen, hydrogen, or the like. As the firing furnace, a batch-type firing furnace or a roller hearth-type continuous firing furnace can be used. The firing temperature is preferably 400 to 800 ° C. In the case where the partition wall is directly formed on the glass substrate, it is preferable to perform baking while maintaining the temperature at 450 to 620 ° C. for 10 to 60 minutes.

  Next, phosphor layers that emit light of RGB colors are formed between predetermined partitions. The phosphor layer can be formed by applying a phosphor paste containing phosphor powder, an organic binder, and an organic solvent as main components between predetermined partitions, drying, and firing as necessary.

  As a method of applying the phosphor paste between predetermined partition walls, a screen printing method in which a pattern is printed using a screen printing plate, a dispenser method in which the phosphor paste is discharged from the tip of a discharge nozzle, or a phosphor paste The phosphor paste of each color can be applied to a predetermined place by the photosensitive paste method using the organic component having photosensitivity as an organic binder.

When the thickness of the R phosphor layer is Tr, the thickness of the G phosphor layer is Tg, and the thickness of the B phosphor layer is Tb,
10 μm ≦ Tr <Tb ≦ 50 μm
10 μm ≦ Tg <Tb ≦ 50 μm
By having such a relationship, the effect of the present invention can be exhibited more. That is, a plasma display having a better color balance (high color temperature) can be produced by making the thickness of blue with low emission luminance thicker than green and red. When the thickness of the phosphor layer is 10 μm or more, sufficient luminance can be obtained. Further, by setting the thickness to 50 μm or less, a wide discharge space can be obtained and high luminance can be obtained. In this case, the thickness of the phosphor layer is measured as a formation thickness at an intermediate point between adjacent barrier ribs. That is, it is measured as the thickness of the phosphor layer formed at the bottom of the discharge space (in the cell).

The member for plasma display of this invention can be produced by baking the apply | coated fluorescent substance layer at 400-550 degreeC as needed.
Using this plasma display member as the back plate, after sealing with the front plate, after enclosing a discharge gas composed of helium, neon, xenon, etc. in the space formed between the front and back substrates, the drive circuit is A plasma display can be manufactured by mounting. The front plate is a member in which a transparent electrode, a bus electrode, a dielectric, and a protective film (MgO) are formed on a substrate in a predetermined pattern. You may form a color filter layer in the part corresponding to the RGB each color phosphor layer formed on the back plate. Further, a black stripe may be formed in order to improve contrast.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to this.
A 42-inch AC (alternating current) type plasma display panel back plate was formed and evaluated. The forming method will be described in order.
(Examples 1 to 23, Comparative Examples 1 to 19)
As a glass substrate, PD-200 (manufactured by Asahi Glass Co., Ltd.) having a size of 590 × 964 × 2.8 mm and 42 inches was used. On this substrate, as a writing electrode, a composition of 70 parts by weight of silver powder having an average particle diameter of 2.0 μm, 69% by weight of bismuth oxide, 24% by weight of silicon oxide, 4% by weight of aluminum oxide, and 3% by weight of boron oxide. 2 parts by weight of glass powder having an average particle size of 2.2 μm, 8 parts by weight of a copolymer of acrylic acid, methyl methacrylate and styrene, 7 parts by weight of trimethylolpropane triacrylate, 3 parts by weight of benzophenone, 7 parts by weight of butyl carbitol acrylate A striped electrode having a pitch of 240 μm, a line width of 100 μm, and a thickness of 3 μm after firing was formed by photolithography using a photosensitive silver paste comprising 3 parts by weight of benzyl alcohol.

  On this substrate, 60% of low melting point glass powder containing 78% by weight of bismuth oxide, 14% by weight of silicon oxide, 3% by weight of aluminum oxide, 3% by weight of zinc oxide, and 2% by weight of boron oxide, and an average particle size of 0%. A dielectric paste having a thickness of 10 μm was formed by applying 10% by weight of a 3 μm titanium oxide powder, 15% ethyl cellulose, and 15% terpineol 15%, followed by baking at 580 ° C.

The photosensitive paste for partition formation used the following composition.
Glass powder: Bi ₂ O ₃ / SiO ₂ / Al ₂ O ₃ / ZnO / B ₂ O ₃ = 82/5/3/5/3/2 Glass powder with an average particle diameter of 2 μm 67 parts by weight Filler: Average Titanium oxide having a particle size of 0.2 μm 3 parts by weight Polymer: “Cyclomer” P (ACA250, manufactured by Daicel Chemical Industries) 10 parts by weight Organic solvent (1): Benzyl alcohol 4 parts by weight Organic solvent (2): Butyl carbitol Acetate 3 parts by weight monomer: Dipentaerythritol hexaacrylate 8 parts by weight Photopolymerization initiator: Benzophenone 3 parts by weight Antioxidant: 1,6-hexanediol-bis [(3,5-di-t-butyl-4-hydroxy Phenyl) propionate] 1 part by weight Organic dye: Basic Blue 26 0.01 part by weight Thixotropic agent: N, N′-12-hydroxy Butylene diamine stearate 0.5 part by weight Surfactant: 0.49 part by weight of polyoxyethylene cetyl ether After applying the above paste to the thickness shown in the table using a die coater, heat in a clean oven under the conditions shown in the table Drying was performed to form a coating film. After drying by heating, a drying process was performed under the conditions shown in the table, and the formed coating film was exposed with a gap of 150 μm from a predetermined photomask. This coating process, heat drying process, dehumidification process, and exposure process are repeated a predetermined number of times. Tables 1 and 2 show the environment of each example and comparative example and the results of shape variation. Table 1 was created under the conditions in the first aspect of the present invention, and the dry humidity environment in each dehumidifying step was adjusted by enclosing dry air of a predetermined humidity in a desiccator. Moreover, in Table 2, it created on the conditions in the 2nd aspect of this invention, and after the heat-drying process, after the photosensitive paste application | coating drying is 1 hour passed in 50% RH, it is the conditions which perform additional drying in drying oven. After going through the dehumidifying step, the one that has gone into the exposure step is shown. The CR environment at this time was 23 ° C. and 50% RH.

  The exposed substrate formed as described above was developed with a 0.5% aqueous ethanolamine solution to form a partition pattern. Each color phosphor paste was applied to the barrier ribs thus formed by screen printing and baked (500 ° C., 30 minutes) to form phosphor layers on the side and bottom of the barrier ribs.

  The plasma display substrate manufactured by the method of the present invention was sealed together with a separately manufactured front glass substrate, and then a discharge gas was sealed and wiring was mounted to obtain a plasma display.

  The width of the partition wall pattern of the substrate, which was created for each of 100 sheets under the conditions of the example and the comparative example, was measured at 35 points in a plane with a microscope, and the variation (3σ) of the width between the substrates was evaluated. The evaluation results are shown in Tables 1 and 2.

  The back plates obtained in Examples 1 to 23 were able to form a good partition pattern with small width variation. The display characteristics of the PDP were also good. About Comparative Examples 1-5 and 8-19, the dispersion | variation in the width | variety was large and favorable display quality was not obtained. In Comparative Examples 6 and 7, since the coating film thickness was thin and the influence of the environment was small, the width variation was small regardless of whether or not the present invention was used.

Schematic view from the side of the heating and drying furnace-dehumidification line-exposure apparatus direct connection apparatus of the present invention Schematic view from the top of the heating and drying furnace-dehumidification line-exposure device direct connection apparatus and dry atmosphere buffer space of the present invention

Explanation of symbols

1: Heating and drying furnace 2: Dehumidification line 3: Exposure machine 4: Dry air inlet 5: Dry air outlet 6: Substrate 7: Conveyor 8: Heating and drying furnace 9: Dehumidification line 10: Exposure machine 11: Drying humidity multistage buffer Space 12: Board 13: Conveyor

Claims (6)

In the pattern forming method in which the following steps (A), (B), (D), and (E) are performed in this order, the step (C) is obtained in the heat drying step between the step (B) and the step (D). A pattern forming method comprising: a dehumidifying step of dehumidifying the obtained coating film in a humidity atmosphere of 25% RH or less.
(A) Coating step of applying a photosensitive paste containing inorganic fine particles, a photosensitive organic component and an organic solvent onto a substrate (B) Heat drying step of heating and drying the coating film obtained in the coating step (D) Exposure step of exposing the coating film obtained in the heat drying step (E) Development step of developing the coating film obtained in the exposure step   The pattern forming method according to claim 1, wherein the step (C) is performed immediately after the step (B).   The pattern forming method according to claim 1 or 2, wherein the film thickness of the coating film obtained in the step (B) is 15 µm or more.   The pattern forming method according to claim 1, wherein the heating temperature in the step (B) is 60 ° C. to 150 ° C. 5.   A method for manufacturing a display substrate, wherein the pattern forming method according to claim 1 is used.   A method for manufacturing a plasma display, wherein the method for manufacturing a display substrate according to claim 5 is used.

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