JP4843392B2 - Method for manufacturing plasma display panel - Google Patents

Description

  The present invention relates to a method for manufacturing a plasma display panel used in a high-precision and inexpensive thin large-screen color display device.

  Plasma display panels are broadly classified into AC types and DC types as driving methods, and there are two types of discharge types: surface discharge type and counter discharge type. At present, the mainstream of plasma display panels is a surface discharge type having a three-electrode structure because of high definition, large screen, and ease of manufacture (see, for example, Patent Document 1).

  The structure of a surface discharge type plasma display panel (hereinafter also referred to as PDP) is shown in FIG. This PDP is configured by disposing a glass front substrate 1 and a back substrate 2 so as to form a discharge space therebetween.

  On the front substrate 1, a plurality of scanning electrodes 3 and sustaining electrodes 4 constituting display electrodes are formed in parallel with each other. A dielectric layer 5 is formed so as to cover the scan electrode 3 and the sustain electrode 4, and a protective layer 6 is formed on the dielectric layer 5. Scan electrode 3 and sustain electrode 4 are each composed of transparent electrodes 3a and 4a and bus electrodes 3b and 4b made of a metal material. The front plate unit 7 is configured by providing the above elements on the front substrate 1.

  A plurality of data electrodes 9 covered with an insulator layer 8 are provided on the back substrate 2, and a grid-like partition wall 10 is provided on the insulator layer 8. A phosphor layer 11 is provided on the surface of the insulator layer 8 and on the side surfaces of the partition walls 10. The back plate unit 12 is configured by providing the above elements on the back substrate 2.

The front plate unit 7 and the back plate unit 12 having the above-described configuration are disposed to face each other so that the scan electrode 3, the sustain electrode 4, and the data electrode 9 intersect each other, and a discharge gas formed therebetween has a discharge gas. For example, a mixed gas of neon and xenon is enclosed. For the phosphor layer 11, phosphors that emit red, green, and blue light by discharge are used, and the phosphors are excited by vacuum ultraviolet light having a short wavelength generated by the discharge, respectively from the red, green, and blue discharge cells. Color display is performed by emitting visible light of red, green, and blue.
JP 2003-243328 A

  The PDP currently commercialized is coated in the cell with 147 nm vacuum ultraviolet rays emitted from Xe in discharge, and the luminance is obtained by exciting and emitting red, green and blue ultraviolet excitation phosphors.

  The pixel level of a 42-inch class PDP is 640 × 480 pixels and a cell pitch of 0.43 mm × 1.29 mm. Furthermore, the pixel level of a full-spec high-definition television expected in recent years is 1920 × 1080, and the cell pitch is as small as 0.16 mm × 0.48 mm in the 42 inch class. Therefore, since the cell pitch and the area per cell are smaller than those of conventional NTSC, a highly accurate technology for forming a phosphor layer that aims to improve luminance is desired.

  However, in the phosphor coating by the screen printing method, there is a problem that it is difficult to accurately fill the phosphor ink in the cells due to the fine cells and the enlargement. This is because it is difficult to accurately apply high-viscosity ink through a narrow region. In addition, in the phosphor photo film method and phosphor photo paste method using phosphor and photosensitive resin, it is possible to embed the phosphor in the partition wall with a certain degree of accuracy, but the exposure and development process is performed for three colors. Therefore, there are problems such as a long process time, a problem of material utilization efficiency, and an influence on the post-process by the development residue.

  As a phosphor coating method capable of solving such problems, an inkjet method has been proposed in which phosphor ink is ejected from a pressurized nozzle to draw a desired pattern on a substrate. In the inkjet method, the phosphor ink is continuously ejected from the nozzles, and the phosphor pattern is filled into the partition walls by moving the substrate or the nozzles.

  However, in the ink jet method in which a liquid containing a phosphor and an organic binder is sprayed from a pressurized nozzle to the load electrode space to deposit a desired pattern in the partition wall, the nozzle diameter is small (at intervals of 0.16 mm or less). In order to put ink, it is necessary to make the nozzle diameter 0.16 mm or less), and the nozzles are likely to be clogged with aggregates in the ink, and it is difficult to apply the phosphor continuously for a long time. is there. Further, in the dispersion using a medium such as beads as in the conventional ink dispersion, the phosphor is greatly damaged, and if the phosphor is dispersed excessively in order to improve the dispersion state of the phosphor and the resin, the phosphor particles Is pulverized, interface states are formed on the phosphor surface, excitation light emission is not efficiently performed by ultraviolet rays, and high luminance is difficult to obtain.

  SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide a manufacturing method capable of forming a phosphor layer with high accuracy in a PDP with high definition.

The present invention, in order to achieve the object, the manufacture of plasma display panels have use the phosphor ink, the phosphor layer is formed by discharging the phosphor ink by an inkjet method comprising and a solvent at least phosphor particles In the method, the phosphor ink contains 10 to 50 resin components with respect to the phosphor particles 100 in a volume ratio, and a solid content in the phosphor ink is 10 vol% or less. Before the step of forming the phosphor layer by discharging the phosphor ink by the method, the phosphor particles are passed by applying a pressure of 100 MPa or more through a nozzle having a diameter of 300 μm or less. A step of dispersing the phosphor layer, and the phosphor layer is formed using a phosphor ink that has undergone the step of dispersing the phosphor particles. .

  According to the present invention, by using a phosphor ink containing at least phosphor particles and a solvent, the phosphor ink is continuously ejected from the nozzle to form a phosphor layer, thereby supporting high definition, The phosphor layer can be formed with high accuracy.

  In the method of manufacturing a plasma display panel of the present invention having the above-described configuration, by providing two or more nozzles, allowing the phosphor ink to pass through the two or more nozzles, and colliding the phosphor ink after passing through It is preferable to disperse the phosphor particles.

  Moreover, it is preferable that the center particle diameter of the phosphor particles after film formation is 0.8 μm or less and the maximum particle diameter is 1.5 μm or less.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present embodiment, the structure of the PDP is the same as that shown in FIG. One front panel 7 (see FIG. 4) of the PDP is formed with a discharge electrode and a black stripe (not shown) composed of the scan electrode 3 and the sustain electrode 4 on the front glass substrate 1, and a dielectric glass layer thereon. It is manufactured by covering with a dielectric layer 5 made of and further forming a protective film 6 made of MgO on the surface of the dielectric layer 5.

  In this embodiment, the black stripe is obtained by uniformly applying a black stripe paste containing a photosensitive resin on the front glass substrate by a screen printing method, drying, patterning and baking by exposure / development processing. Form.

  The discharge electrode is a silver electrode. An electrode paste containing a photosensitive resin is uniformly applied on the front glass substrate 1 by a screen printing method, and after drying, a pattern is formed by exposure and development, and a discharge electrode is formed by firing. To do.

  Dielectric glass layer is a paste made by mixing powder of glass composition of lead oxide 65 wt%, boron oxide 15 wt%, silicon oxide 20 wt% with solvent and resin to form a coating film by screen printing method Then, it is formed by baking after drying. The MgO protective layer is formed by depositing magnesium oxide.

  The rear panel 12 has the data electrodes 9 formed on the rear glass substrate 2, the barrier ribs 10 are formed on the data electrodes 9 at a predetermined pitch, and the phosphor layer 11 is formed between the barrier ribs 10 with red, green, and blue phosphors. Produced by forming.

  In this embodiment, the data electrode 9 is a silver electrode, and an electrode paste containing a photosensitive resin is uniformly applied on the front glass substrate 2 by screen printing, and after drying, a pattern is formed by exposure / development processing. The data electrode 9 is formed by firing. The partition wall 10 is formed by forming a partition wall material film by screen printing and then drying, and after patterning by exposure / development processing using a dry film containing a photosensitive resin, it is excavated by sandblasting, peeled off and dried. By forming.

Further, as phosphors, phosphor particles of red [YBO ₃ : Eu ³⁺ ], green [Zn ₂ SiO ₄ : Mn], and blue [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] are used, and phosphor inks are used. Then, the phosphor layer 11 is formed by applying the ink by an ink discharge method.

  After the front panel 7 and the back panel 12 produced as described above are bonded together using sealing glass, the inside of the panel is evacuated, and Ne—Xe gas is sealed at a predetermined pressure to produce a PDP.

Here, the phosphor ink material includes red [YBO ₃ : Eu ³⁺ ], green [Zn ₂ SiO ₄ : Mn], blue [BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ] as a phosphor, and ethyl cellulose as a resin. Was mixed at the composition ratio shown in Table 1 shown in FIG. 3, and the remaining amount was adjusted with α-terpineol as a solvent to prepare a phosphor ink mixture. In Table 1, the phosphor solid content indicates the amount of phosphor particles.

  As an alternative to the resin for the phosphor ink, one or two of cellulose resins such as nitrocellulose and hydroxyethyl cellulose, acrylic resins and copolymers such as polybutyl acrylate and polymethacrylate, polyvinyl alcohol, polyvinyl butyral, etc. Similar results are obtained even when more than one species is used in combination.

  Further, as an alternative to the solvent, terpenes such as β-, γ-terpineol, ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates , Ethylene glycol dialkyl ether acetates, diethylene glycol monoalkyl ether acetates, diethylene glycol dialkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol dialkyl ether acetates, methanol , Ethanol, isop Similar results can be obtained even when one or a mixture of two or more alcohols such as lopanol and 1-butanol is used.

  The present embodiment is characterized by a manufacturing method for forming the phosphor layer 11 using the phosphor ink produced as described above. That is, the above phosphor ink has a step of passing through a nozzle having a diameter of 300 μm or less by applying a pressure of 100 MPa or more to disperse the phosphor layer 11 using the phosphor ink dispersed in the step. Form.

  Then, the dispersed phosphor ink is ejected to the back plate cell by an inkjet device, dried at 100 ° C., and then baked at 500 ° C. to form the phosphor layer 11.

  FIG. 1 shows the configuration of an apparatus for carrying out the step of dispersing phosphor ink in the manufacturing method of the present embodiment. In FIG. 1, 21 is a tank containing phosphor ink, 22 is a circulation pump for circulating the phosphor ink from the tank 21, 23 is a pressure generator, and 24 is a nozzle. The pressure generator 23 and the nozzle 24 constitute a path for dispersing the phosphor ink.

  That is, for the phosphor ink, which is a mixed liquid as described above, a step of applying a pressure of 100 MPa or more through the nozzle 24 having a diameter of 300 μm or less by the pressure generator 23 to disperse is performed.

  FIG. 2 shows the configuration of an apparatus for carrying out another example of the step of dispersing the phosphor ink. In FIG. 2, the same parts as those in FIG.

  In the example shown in FIG. 2, by providing two or more nozzles 24 (two in FIG. 2), two or more paths by the two or more nozzles are provided, and the two or more nozzles 24 are used. The particles are dispersed by passing through the path and colliding the phosphor ink after passing through the path. As in the example shown in FIG. 1, the nozzle 24 has a diameter of φ300 μm or less, and is configured to pass by applying a pressure of 100 MPa or more by the pressure generator 23.

  When changing the nozzle diameter and the pressure generated by the pressure generator in the case of providing the dispersion process by one nozzle system shown in FIG. 1 and the case of providing the dispersion process by two nozzle systems shown in FIG. The phosphor ink was evaluated. The nozzle diameter and pressure in the specific examples are as described in (Table 1).

  In Table 1, as the evaluation after dispersion, the particle size distribution (apparatus: Microtrac HRA) and sedimentation (solid-liquid separation start time) of the phosphor particles were evaluated. That is, as a criterion for ink stability, the particle size distribution is such that the center particle size is 0.8 μm or less, the maximum particle size is 1.5 μm or less, and the sedimentation property is 4 hours or more. ”, Those that were not satisfied were marked with“ x ”.

  As is clear from this (Table 1), according to the present invention, the ink stability of the phosphor ink is good, and as a result, the phosphor layer can be formed with high precision corresponding to high definition.

  As described above, according to the present invention, it is possible to correspond to high definition, and to form a phosphor layer accurately and stably, which is useful for realizing a high definition PDP.

The block diagram which shows an example of the apparatus for enforcing the manufacturing method of the plasma display panel in one embodiment of this invention The block diagram which shows the other example of the apparatus for enforcing the manufacturing method of the plasma display panel in one embodiment of this invention The table | surface which shows the measurement result which evaluates the stability of the phosphor ink obtained by one embodiment of this invention Exploded perspective view showing the configuration of the plasma display panel

Explanation of symbols

21 Tank 22 Circulation pump 23 Pressure generator 24 Nozzle

Claims (2)

There use a phosphor ink containing and a solvent at least phosphor particles, in the manufacturing method of the plasma display panel to form a phosphor layer by discharging the phosphor ink by the ink jet method, the phosphor ink by volume The phosphor particle 100 contains 10 to 50 resin components and the solid content in the phosphor ink is 10 vol% or less, and the phosphor ink is ejected by the inkjet method to phosphor. Before the step of forming the layer, the phosphor ink is passed through a nozzle having a diameter of 300 μm or less under a pressure of 100 MPa or more to disperse the phosphor particles. A method of manufacturing a plasma display panel, wherein the phosphor layer is formed using a phosphor ink that has been dispersed. .   The phosphor particles are dispersed by providing two or more of the nozzles, allowing the phosphor ink to pass through the two or more nozzles, and colliding the phosphor ink after passing through the nozzles. A method for manufacturing a plasma display panel.

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