JP4139053B2 - Method for manufacturing front plate for plasma display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a front panel for a plasma display panel, and more particularly to a front panel that enables a plasma display panel with high display contrast.
[0002]
[Prior art]
In recent years, a plasma display panel (PDP) has been developed as one of flat displays. For example, in an AC type PDP, a composite electrode composed of a transparent electrode (sustain electrode) and a bus electrode is usually formed in parallel to each other, and a front plate on which a dielectric layer is formed so as to cover the composite electrode, and orthogonal to the composite electrode Thus, a back plate having address electrodes formed in parallel to each other is disposed to face the back plate. A dielectric layer is formed on the front side of the back plate so as to cover the address electrodes, and a barrier is formed at a position between the address electrodes on the dielectric layer. A phosphor layer is provided so as to cover the dielectric layer. Thus, a space defined by the front plate, the back plate, and the barrier and intersecting the composite electrode and the address electrode becomes a cell as a display element. In such an AC type PDP, a predetermined voltage is applied from an AC power source between the composite electrodes on the front plate to form an electric field, whereby discharge is performed in the cell, and the phosphor layer is formed by ultraviolet rays generated by this discharge. It emits light.
[0003]
[Problems to be solved by the invention]
However, the conventional PDP has a problem in that external light reflection occurs at the bus electrodes on the front plate, making it difficult to display a high-contrast image.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a front plate for a plasma display panel that enables a plasma display panel with high display contrast.
[0004]
  In order to achieve such an object, the present invention comprises a substrate, a composite electrode formed on the substrate, and a dielectric layer formed so as to cover the composite electrode. The bus electrode has a two-layer structure in which a black electrode and a bus main electrode are sequentially laminated from the transparent electrode side.In the manufacturing method of the front plate for a plasma display panel, the black electrode and the bus main electrode are printed by overlapping the black conductor ink in an undried state by an offset printing method to form a black electrode pattern, On the black electrode pattern in an undried state, a conductor ink is printed in an undried state multiple times by an offset printing method to form a bus main electrode pattern, and the black electrode pattern and the bus main electrode pattern are simultaneously formed. Firing and formingThe configuration is as follows.
[0005]
  The present invention also provides:The black conductive ink contains at least a conductive powder, a black inorganic oxide, glass frit, and an organic component that can be removed by baking. The conductive ink can be removed by baking with conductive powder, glass frit, and the like. The composition is such that it contains at least an organic component..
  The present invention also provides:The conductive powder, the black inorganic oxide, and the glass frit content in the black conductor ink, the formed black electrode is 60 to 98% by weight of the conductive powder, 1 to 30% by weight of the black inorganic oxide, The glass frit is set so as to contain in the range of 1 to 10% by weight, the content of the conductive powder and the glass frit in the conductive ink, the formed bus main electrode is 90 to 99% of the conductive powder. %, Glass frit is set so as to contain in the range of 1 to 10% by weight.The configuration is as follows.
[0006]
  The present invention also provides:The printing plate used in the offset printing method is an intaglio plate having a plate depth in the range of 1 to 8 μm.The configuration is as follows.
[0007]
  The present invention also provides a dielectric layer covering the black electrode pattern and the bus main electrode pattern by using a dielectric forming paste containing at least an inorganic component containing glass frit and an organic component that can be removed by baking. Forming a pattern, and simultaneously firing the dielectric layer pattern, the black electrode pattern, and the bus main electrode pattern to form the black electrode, the bus main electrode, and the dielectric layer..
  Furthermore, the present invention providesPrior to forming the dielectric layer pattern, the black electrode pattern and the bus main electrode pattern are subjected to heat curing treatment or ionizing radiation curing treatment.The configuration is as follows.
[0008]
In the present invention as described above, the black electrode of the bus electrode having a two-layer structure functions to prevent external light reflection at the bus main electrode, and the bus main electrode functions to reduce the resistance of the bus electrode.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 1 is a schematic sectional view showing an embodiment of a front plate for a plasma display panel of the present invention, and FIG. 2 is a schematic configuration diagram showing an AC type plasma display panel (PDP) using the front plate of the present invention. The front plate and the back plate are separated from each other). 1 and 2, the PDP 1 has a front plate 11 and a back plate 21 arranged in parallel and facing each other, and a barrier 26 is formed on the front side of the back plate 21 so as to stand upright. The front plate 11 and the back plate 21 are held at a constant interval by the barrier 26.
[0010]
The front plate 11 of the present invention has a front glass substrate 12, and a composite electrode composed of a transparent electrode 13 and a bus electrode 14 as sustain electrodes is formed on one side of the front glass substrate 12 in parallel with each other so as to cover it. Is provided with a dielectric layer 15. The bus electrode 14 has a two-layer structure in which the black electrode 14a and the bus main electrode 14b are laminated from the transparent electrode 13 side. In the AC type PDP shown in FIG. 2, the MgO layer 16 is provided on the dielectric layer 15.
[0011]
Further, the back plate 21 has a back glass substrate 22, and on the front side of the back glass substrate 22, an address electrode 24 is positioned between the barriers 26 so as to be orthogonal to the composite electrode via a base layer 23. Are formed in parallel to each other, and a dielectric layer 25 is formed so as to cover this, and a phosphor layer 27 is provided so as to cover the wall surface of the barrier 26 and the bottom surface of the cell.
[0012]
In this AC type PDP 1, a predetermined voltage is applied from an AC power source between the composite electrodes on the front glass substrate 12 to form an electric field, so that the front glass substrate 12, the rear glass substrate 22, and the barrier 26 are partitioned. Discharge is performed in each cell as a display element. The phosphor layer 27 emits light due to the ultraviolet rays generated by the discharge, and the observer visually recognizes the light transmitted through the front glass substrate 12.
[0013]
Examples of the front glass substrate 12 used for the front plate 11 of the present invention include quartz glass, soda glass, high strain point glass, pyrex glass, and synthetic quartz plate.
[0014]
The transparent electrode 13 of the front plate 11 is made of indium tin oxide (ITO), tin oxide (SnO₂), Antimony-doped SnO₂, ITO or antimony doped titanium oxide (TiO₂), Ruthenium oxide (RuO)₂), ITO or antimony doped zirconium oxide (ZrO)₂) And the like, and the thickness is about 0.02 to 2 μm.
[0015]
The black electrode 14a constituting the bus electrode 14 contains 60 to 98% by weight of conductive powder, 1 to 30% by weight of black inorganic oxide, and 1 to 10% by weight of glass frit. When the content of the conductive powder is less than 60% by weight, the conductivity of the bus electrode 14 is adversely affected. Further, when the content of the black inorganic oxide is less than 1% by weight, the effect of preventing the external light reflection of the bus main electrode 14b by the black electrode 14a cannot be sufficiently obtained. The thickness of the black electrode 14a is preferably about 1 to 10 μm.
[0016]
The bus main electrode 14b constituting the bus electrode 14 contains 90 to 99% by weight of conductive powder and 1 to 10% by weight of glass frit. When the content of the conductive powder is less than 90% by weight, it is difficult for the bus electrode 14 to have necessary conductivity. The thickness of the bus main electrode 14b is preferably about 1 to 10 μm.
[0017]
The black electrode 14a may be formed by printing and baking by an offset printing method using a black conductor ink containing at least a conductive powder, a black inorganic oxide, a glass frit, and an organic component that can be removed by baking. it can. The bus main electrode 14b can be formed by printing and baking by an offset printing method using a conductive ink containing at least conductive powder, glass frit, and an organic component that can be removed by baking. In the present invention, it is preferable to form the black electrode and the bus main electrode by simultaneous firing. In this case, the black electrode pattern is printed by the offset printing method, the bus main electrode pattern is printed on the black electrode pattern by the offset printing method (wet on wet), and the black electrode pattern and the bus main electrode pattern are simultaneously fired. Can do.
[0018]
Examples of the conductive powder contained in the above black conductor ink and conductor ink include gold, silver, copper, aluminum, platinum, nickel, palladium, alloys thereof, and the like, alone or in combination. Can be used. The shape of the conductive powder may be any of an indeterminate shape, a lump shape, a scale shape, a microcrystalline shape, a spherical shape, a flake shape, and the like. In particular, the tap density is 2.5 to 5 g / cm.^ThreeThe average particle size is 0.02 to 1 μm, preferably 0.1 to 0.5 μm, and the specific surface area is 0.5 to 3 m.²The use of conductive powder in the range of / g is desirable.
[0019]
Examples of the black inorganic oxide contained in the black conductive ink include Cr—Co—Mn—Fe, Cr—Cu, Cr—Cu—Mn, Mn—Fe—Cu, Cr—Co—Fe, and Co—Mn—. Complex oxides such as Fe and Co-Ni-Cr-Fe, manganese oxide (MnO₂), Molybdenum oxide (MoO)₂), Chromium oxide (Cr₂O_Three), Copper oxide (CuO), palladium oxide (PdO), ruthenium oxide (RuO)₂And the like, and can be used alone or in combination. The average particle size of such a black inorganic oxide is preferably about 0.02 to 1 μm. If the average particle size of the black inorganic oxide is less than 0.02, secondary aggregates are easily formed and dispersion is difficult, and if it exceeds 1 μm, the denseness and smoothness after firing are inferior, which is not preferable. .
[0020]
Examples of the glass frit contained in the black conductor ink and the conductor ink include, for example, a softening temperature of 400 to 600 ° C. and a thermal expansion coefficient α.₃₀₀ Is 70 × 10^-7~ 95x10^-7Glass frit with a glass transition temperature of 400-500 ° C./° C. can be used, and PbO / SiO₂/ B₂O_ThreeGlass, Bi₂O_Three/ SiO₂/ B₂O_ThreeGlass, Bi₂O_Three/ ZnO / B₂O_ThreeGlass, ZnO / B₂O_Three/ It is preferable to use a glass frit that does not contain an alkali oxide such as an alkaline earth metal oxide glass. If the softening temperature of the glass frit exceeds 600 ° C., it is necessary to increase the firing temperature. For example, if the heat resistance of the back glass substrate is low, thermal deformation occurs in the firing stage, which is not preferable. Further, when the softening temperature of the glass frit is less than 400 ° C., the glass frit is fused before the organic components are completely decomposed, volatilized and removed by firing, and therefore, voids are easily generated, which is not preferable. Furthermore, the thermal expansion coefficient α of the glass frit₃₀₀ Is 70 × 10^-7/ ° C or 95 x 10^-7If it exceeds / ° C., the difference from the coefficient of thermal expansion of the electrode formed body may be too large, which may cause distortion and the like. The average particle size (D₅₀) Is in the range of 0.1 to 2 μm.
[0021]
The black conductor ink and the organic component contained in the conductor ink are those that volatilize and decompose by firing and do not leave carbides in the fired film. For example, alkyd resins, modified alkyd resins , Modified epoxy resin, urethanized oil, urethane resin, rosin resin, rosinized oil, maleic acid resin, maleated oil, polybutene resin, diallyl phthalate resin, polyester resin, polyester oligomer, mineral oil, vegetable oil, urethane oligomer, (meta ) A copolymer of allyl ether and maleic anhydride (this copolymer may contain other monomers (for example, styrene etc.) as a copolymerization component) or the like, or a combination of two or more Can be used. In addition, in the conductor ink, as an additive, polymerization accelerator, dispersant, wetting agent, thickener, leveling agent, antifouling agent, gelling agent, silicone oil, silicone resin, antifoaming agent, plasticizer, A drying accelerator or the like may be appropriately selected and added.
[0022]
Furthermore, when making black conductor ink and conductor ink into an oxidation polymerization type, an oxidation polymerization catalyst, an oxidation polymerization inhibitor, a polymerization inhibitor, etc. can be added suitably. Moreover, when making a conductor ink into an ultraviolet curable type, a polymerization initiator, a polymerization inhibitor, a reactive monomer, etc. can be added suitably.
[0023]
In addition, a metal chelate compound, a carboxylic acid metal compound, a metal acetate, a metal alkoxide compound, or the like may be appropriately selected and added to the black conductor ink or the conductor ink for the purpose of imparting gel elasticity. Typical examples of the metal chelate compound include aluminum chelate, and examples of the carboxylic acid metal compound include aluminum octylate and aluminum stearate.
[0024]
When using a solvent for black conductor ink or conductor ink, it is preferable to use a solvent having a boiling point of 350 ° C. or less. Solvents that are easily absorbed by the blanket change the characteristics of the black conductor ink and the conductor ink, and are unfavorable because the blanket swells and print dimensional accuracy decreases. The solvent to be used is preferably a petroleum solvent such as normal paraffin, isoparaffin, naphthene, alkylbenzene aromatics, or a mixed solvent combining these. When using a mixed solvent, it is preferable to select in consideration of printability such as scumming resistance.
[0025]
Moreover, a conventionally well-known blanket can be used as a blanket used for offset printing. For example, the layer structure is composed of a surface rubber layer / base fabric / cushion layer / base fabric / adhesive layer / base fabric, the surface rubber layer / adhesive layer / film (polyethylene terephthalate, polyethylene naphthalate, polyimide, etc.), etc. Can be used. The surface rubber layer can be formed of one kind of nitrile butadiene rubber, butyl rubber, silicon rubber, urethane rubber, ethylene propylene rubber, fluorine rubber, chloroprene rubber, or a mixture of two or more kinds. Further, the surface rubber layer can have a surface glossiness of 1 to 90 °, a surface rubber layer thickness of 0.2 to 1 mm, a surface rubber layer hardness of 40 to 80 °, The blanket hardness can be in the range of 70-90 °. Also, the surface rubber layer is made of SiO for the purposes of hardness adjustment, antistatic, etc.₂, Al₂O_ThreeTiO₂, ZrO₂, CaO, MgO, BaO, carbon, SnO₂In addition, powder such as ITO (indium tin oxide) may be contained.
[0026]
Furthermore, as a printing plate (flat plate, intaglio) used for offset printing, a silicon plate, a waterless plate, a resin plate, a metal plate, a glass plate, etc. can be used, and a release treatment is applied to each of the above printing plates. You may use what gave (silicon coat, fluorine coat, etc.). In particular, the plate depth is 1 to 8 μm, and the cross-sectional space shape of the recess corresponding to the plate depth is square or inverted trapezoid (the length on the plate base side is 70 to 100% of the length on the open side) A printing plate having a trapezoidal shape is preferred.
[0027]
The dielectric layer 15 of the front plate 11 is formed by using a dielectric forming paste, for example, directly by screen printing, or by patterning the dielectric forming paste layer formed by film transfer or coating. It can be formed by forming a dielectric layer pattern and firing it.
[0028]
The dielectric forming paste contains at least an inorganic component containing glass frit and an organic component that can be removed by firing. When forming and patterning a dielectric formation paste layer by said film transfer, the dielectric formation paste containing the photosensitive resin composition as an organic component mentioned later is used. This dielectric forming paste is applied onto a transfer substrate to form a dielectric forming paste layer, and this dielectric forming paste layer is transferred onto the front glass substrate 12 so as to cover the black electrode pattern and the bus main electrode pattern. Thus, a dielectric layer pattern is formed. The dielectric layer pattern, the black electrode pattern, and the bus main electrode pattern are preferably fired simultaneously to form each layer. In this case, before the dielectric layer pattern is formed, the black electrode pattern and the bus main electrode pattern may be subjected to a heat curing process or an ionizing radiation curing process. Which curing treatment is performed can be appropriately selected according to the conductor ink to be used. In the case of thermosetting treatment, the heating conditions can be set within a range of about 100 to 250 ° C. and about 1 to 30 minutes. In the case of ionizing radiation curing treatment, the irradiation dose is 100 to 2000 mJ / cm.²It can be set within a range.
[0029]
As said glass frit, the glass frit mentioned by the above-mentioned conductor ink can be used, for example, The average particle diameter (D of glass frit)₅₀) Is in the range of 0.1 to 10 μm, preferably 0.5 to 5 μm. Other inorganic components include aluminum oxide, boron oxide, silica, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, ruthenium oxide, barium oxide, tin oxide, indium tin oxide, silicate, steatite, zircon, forsterite, An inorganic powder such as beryllia can be contained in the range of 10 to 500 parts by weight with respect to 100 parts by weight of the glass frit. The shape of the inorganic powder may be any of a spherical shape, an indeterminate shape, a block shape, a needle shape, a rod shape, and the like. Such an inorganic powder preferably has an average particle size in the range of 0.1 to 20 μm, serves as an aggregate to prevent pattern casting during firing, and to control reflectance and dielectric constant. Is.
[0030]
As an organic component contained in the dielectric forming paste, a thermoplastic resin can be used. For example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, Isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxy Polymers or copolymers consisting of one or more propyl methacrylates, ethyl cellulose and the like are preferred.
Moreover, at least a polymer, a monomer, and an initiator can be used as the organic component that can be removed by baking.
[0031]
The content of the thermoplastic resin or the photosensitive resin composition in the dielectric forming paste is set in the range of 1 to 50 parts by weight, preferably 5 to 35 parts by weight with respect to 100 parts by weight of the inorganic component. be able to.
Furthermore, in the dielectric forming paste, as additives, sensitizers, polymerization terminators, chain transfer agents, leveling agents, dispersants, transferability imparting agents, stabilizers, antifoaming agents, thickeners, precipitation inhibitors A release agent or the like can be contained as necessary.
[0032]
【Example】
Next, an Example is shown and this invention is demonstrated further in detail.
(Example)
First, black conductor ink and conductor ink having the following composition were prepared.
[0033]
Composition of black conductor ink
・ Silver powder: 70 parts by weight
(Tap density 4.5g / cm^Three, Average particle size 0.3 μm)
・ Black inorganic oxide (RuO₂) 7 parts by weight
・ Glass frit: 3 parts by weight
(Bi₂O_Three/ SiO₂/ B₂O_Three/ Alkaline earth metal oxides
(No alkali), thermal expansion coefficient 80 × 10^-7/ ℃, glass transition
(Temperature 460 ° C, softening point 520 ° C, average particle size 0.9μm)
・ Resin (Marialim AAB-0851 manufactured by NOF Corporation) 20 parts by weight
(Allyl ether, maleic anhydride, styrene copolymer)
[0034]
Conductor ink composition
・ Silver powder: 77.5 parts by weight
(Tap density 4.5g / cm^Three, Average particle size 0.3 μm)
・ Glass frit: 2.5 parts by weight
(Bi₂O_Three/ SiO₂/ B₂O_Three/ Alkaline earth metal oxides
(No alkali), thermal expansion coefficient 81 × 10^-7/ ℃, glass transition
(Temperature 460 ° C, softening point 525 ° C, average particle size 0.9 µm)
・ Resin (Marialim AAB-0851 manufactured by NOF Corporation) 20 parts by weight
(Allyl ether, maleic anhydride, styrene copolymer)
[0035]
Next, an offset printing machine (Ector LCD printing machine manufactured by Kousyo Co., Ltd.) as shown in FIGS. 3 and 4 was prepared. FIG. 3 is a plan view showing a schematic structure of the offset printing machine used, and FIG. 4 is a side view of the offset printing machine shown in FIG. 3 and 4, an offset printing machine 31 includes a base 32 in which a printing surface plate 33 and a printing platen 34 are arranged at a predetermined interval, and two guide rails 35 and 35 are laid in parallel. And a print head 36 that can freely move on the guide rails 35 and 35 by a moving mechanism that does not. The print head 36 is provided with a blanket roll 37 that can be moved up and down, and a first inking roll group 38. The base 32 is provided with a second inking roll group 39 and an ink blade 40 for storing conductive ink.
[0036]
A glass substrate (soda glass, 350 mm × 450 mm, thickness 2.1 mm) is placed on the printing surface plate 33 of the offset printing machine 31 (the part indicated by the one-dot chain line in FIG. 3), and the printing platen 34 ( A printing plate (a waterless plate (DG-2) manufactured by Toray Industries, Inc., width of 50 μm) is attached to a portion indicated by a one-dot chain line in FIG. 3 and a black conductor ink is used under the following conditions. Pattern printing was performed to form a black electrode pattern. The formed black electrode pattern was inspected by image comparison, and the defective portion was corrected.
[0037]
Printing conditions
Printing speed: 600mm / sec
Printing pressure: 0.2 mm (both on the printing plate and on the substrate)
Number of prints: 2 times
Blanket: NBR Blanket
[0038]
Next, a bus main electrode pattern was formed on the black electrode pattern (in an undried state) by the above-described offset printer 31 using a conductor ink. In this case, the printing plate had an image line width of 50 μm, and pattern printing was performed under the following conditions. The formed bus main electrode pattern was inspected by image comparison, and the defective portion was corrected.
[0039]
Printing conditions
Printing speed: 600mm / sec
Printing pressure: 0.2 mm (both on the printing plate and on the substrate)
Number of prints: 2 times
Blanket: NBR Blanket
[0040]
Next, a dielectric forming paste having the following composition was prepared.
Composition of dielectric forming paste
・ Glass frit: 60 parts by weight
(PbO / SiO₂/ B₂O_ThreeGlass (no alkali),
Thermal expansion coefficient 75 × 10^-7/ ° C, glass transition temperature 470 ° C,
(Softening point 570 ° C, average particle size 1 µm)
・ Titanium oxide: 25 parts by weight
・ Ethylcellulose: 5 parts by weight
・ Turpineol: 10 parts by weight
・ Butyl carbitol acetate: 10 parts by weight
[0041]
Next, the black electrode pattern and the bus main electrode pattern are subjected to thermosetting treatment (180 ° C., heating condition for 15 minutes), and then the dielectric forming paste is applied to the black electrode pattern and the bus main electrode pattern. A dielectric layer pattern (thickness: 20 μm) was formed by coating the entire surface of the substrate (but not covering the electrode terminal portion) by a screen printing method so as to cover the laminated pattern made of and drying.
[0042]
Next, the glass substrate on which the black electrode pattern, the bus main electrode pattern, and the dielectric pattern are formed as described above is fired at 600 ° C. to obtain the bus electrode (two-layer structure of the black electrode and the bus main electrode). A front surface plate of the present invention was obtained by forming a dielectric layer.
[0043]
The formed black electrode contains 87.5% by weight of silver powder, 8.8% by weight of black inorganic oxide, and 3.8% by weight of glass frit, and has a line width of 50 ± 5 μm and a film thickness. The swell was 1 μm or less, and the film thickness was 2 μm. The bus main electrode contains 96.9% by weight of silver powder and 3.1% by weight of glass frit, has a line width of 50 ± 5 μm, a film thickness of 1 μm or less, and a film thickness of 2 μm. Secured. Furthermore, the specific resistance of the bus electrode having a two-layer structure of the black electrode and the bus main electrode was about 3.0 μΩ · cm, which was a good electrode pattern. Further, the dielectric layer had a thickness of 10 μm, and the surface state was smooth and good. As a result of the following external light reflection test, it was confirmed that the external light reflectance of light incident from the glass substrate side was 1% or less, and the external light reflection was at a very low level.
[0044]
External light reflection test
The front plate was irradiated with light having a wavelength range of 450 to 750 nm from the glass substrate side, and the reflectance from the glass substrate side was measured with a spectrophotometer.
[0045]
(Comparative Example 1)
A front plate (Comparative Example 1) was produced in the same manner as in the example except that the bus electrode was formed using only the above conductor ink. The printing plate used had an image line width of 50 μm, and pattern printing was performed under the following conditions.
Printing conditions
Printing speed: 600mm / sec
Printing pressure: 0.2 mm (both on the printing plate and on the substrate)
Number of prints: 2 times
Blanket: NBR Blanket
[0046]
The formed bus electrode contains 77.5% by weight of silver powder and 2.5% by weight of glass frit, has a line width of 50 ± 5 μm, a film thickness of 1 μm or less, and a film thickness of 2 μm. The specific resistance was about 3.0 μΩ · cm, which was a good electrode pattern. Further, the dielectric layer had a thickness of 10 μm, and the surface state was smooth and good. However, as a result of performing the same external light reflection test as described above, the external light reflectance of the light incident from the glass substrate side exceeded 10%, and this front plate (Comparative Example 1) has a large external light reflection and is thus applied to the plasma display panel. It was confirmed that was not available.
[0047]
(Comparative Example 2)
A front plate (Comparative Example 2) was produced in the same manner as in the Example except that the black bus electrode was formed using only the following black conductor ink.
Composition of black conductor ink
・ Silver powder: 50 parts by weight
(Tap density 4.5g / cm^Three, Average particle size 0.3 μm)
・ Black inorganic oxide (RuO₂) 27 parts by weight
・ Glass frit: 3 parts by weight
(Bi₂O_Three/ SiO₂/ B₂O_Three/ Alkaline earth metal oxides
(No alkali), thermal expansion coefficient 80 × 10^-7/ ℃, glass transition
(Temperature 460 ° C, softening point 520 ° C, average particle size 0.9μm)
・ Resin (Marialim AAB-0851 manufactured by NOF Corporation) 20 parts by weight
(Allyl ether, maleic anhydride, styrene copolymer)
[0048]
The formed black bus electrode contains 62.4% by weight of silver powder, 33.8% by weight of black inorganic oxide, and 3.8% by weight of glass frit, and has a line width of 50 ± 5 μm, As a result of conducting the same external light reflection test as described above, the undulation of the film thickness is 1 μm or less and the film thickness is 2 μm. As a result, the external light reflectance of the light incident from the glass substrate side is 1% or less, and the external light reflection Was found to be at a very low level. However, the content of the black inorganic oxide is large, the specific resistance of the bus electrode is about 10 μΩ · cm, and it was confirmed that this front plate (Comparative Example 2) cannot be used for a plasma display panel.
[0049]
【The invention's effect】
As described above in detail, according to the present invention, by the black electrode containing 60 to 98% by weight of conductive powder, 1 to 30% by weight of black inorganic oxide, and 1 to 10% by weight of glass frit. External light reflection at the bus main electrode is prevented, and sufficient conductivity is imparted to the bus electrode by the bus main electrode containing conductive powder in the range of 90 to 99% by weight and glass frit in the range of 1 to 10% by weight. In addition, by using the front plate of the present invention, a plasma display panel capable of obtaining a high-contrast image display becomes possible. Further, by forming the black electrode and the bus main electrode by overprinting of offset printing, the productivity of the bus electrode that exhibits the above-described effect is increased.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a front plate for a plasma display panel according to the present invention.
FIG. 2 is a schematic configuration diagram showing an AC type plasma display panel using the front plate of the present invention (showing a state where the front plate and the back plate are separated);
FIG. 3 is a plan view showing a schematic structure of an offset printing machine used in Examples.
4 is a side view of the offset printing machine shown in FIG. 3. FIG.
[Explanation of symbols]
1 ... Plasma display panel
11 ... Front plate
12 ... Front glass substrate
13 ... Transparent electrode
14 ... Bus electrode
14a ... Black electrode
14b ... Bus main electrode
15. Dielectric layer
21 ... Back plate
22 ... Back glass substrate
23 ... Underlayer
24 ... Electrode
25. Dielectric layer
26 ... Barrier

Claims (6)

A substrate, a composite electrode composed of a transparent electrode and a bus electrode formed on the substrate, and a dielectric layer formed so as to cover the composite electrode, and the bus electrode includes a black electrode from the transparent electrode side. the method of manufacturing a front plate of the bus main electrode is for to a plasma display panel, such a two-layer structure, which are sequentially stacked,
The black electrode and the bus main electrode are formed by printing a black conductive ink on the black electrode pattern in an undried state by printing a plurality of times in a non-dried state using a black conductive ink to form a black electrode pattern. A plurality of times in an undried state by an offset printing method to form a bus main electrode pattern, and the black electrode pattern and the bus main electrode pattern are simultaneously fired to form a plasma display panel. Method for manufacturing a front plate for use . The black conductive ink contains at least a conductive powder, a black inorganic oxide, glass frit, and an organic component that can be removed by baking. The conductive ink can be removed by baking with conductive powder, glass frit, and the like. The method for producing a front plate for a plasma display panel according to claim 1, comprising at least an organic component . The conductive powder, the black inorganic oxide, and the glass frit content in the black conductor ink, the formed black electrode is 60 to 98% by weight of the conductive powder, 1 to 30% by weight of the black inorganic oxide, The glass frit is set so as to contain in the range of 1 to 10% by weight, the content of the conductive powder and the glass frit in the conductive ink, the formed bus main electrode is 90 to 99% of the conductive powder. 3. The method for producing a front plate for a plasma display panel according to claim 2, wherein the glass frit is contained in a range of 1 to 10% by weight . 4. The front plate for a plasma display panel according to claim 1, wherein the printing plate used in the offset printing method is an intaglio plate having a plate depth in the range of 1 to 8 μm. 5. manufacturing method. Using a dielectric forming paste containing at least an inorganic component containing glass frit and an organic component that can be removed by firing, a pattern for a dielectric layer is formed so as to cover the black electrode pattern and the bus main electrode pattern, 5. The dielectric layer pattern, the black electrode pattern, and the bus main electrode pattern are simultaneously fired to form the black electrode, the bus main electrode, and the dielectric layer. The manufacturing method of the front plate for plasma display panels in any one . 6. The plasma display panel front panel according to claim 5, wherein the black electrode pattern and the bus main electrode pattern are subjected to a thermal curing process or an ionizing radiation curing process before forming the dielectric layer pattern. Manufacturing method of face plate .

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