JP2013058433A - Plasma display panel and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel which is low in power consumption and has high luminous efficiency.SOLUTION: The present invention is a method for manufacturing a plasma display panel, in which a front plate comprising a protective layer and a back plate are disposed facing each other with a discharge space formed therebetween and are sealed and the discharge space is evacuated. The protective layer comprises a base film and metal oxide particles. The metal oxide particles are magnesium oxide crystals. The base film contains a carbonate composite material of cesium. After formation of the protective layer, the surface of the protective layer is exposed to a reducing organic gas.

Description

  The present invention relates to a configuration of a plasma display panel.

  Since plasma display panels (hereinafter referred to as PDP) can achieve high definition and large screen, 65-inch class televisions have been commercialized. In recent years, PDP has been applied to high-definition televisions having more than twice the number of scanning lines as compared with the conventional NTSC system, and PDP containing no lead component is required in consideration of environmental problems.

  A PDP basically includes a front plate and a back plate. The front plate is a glass substrate made of sodium borosilicate glass by a float method, a display electrode composed of a striped transparent electrode and a bus electrode formed on one main surface of the glass substrate, and a display electrode A dielectric layer that covers and acts as a capacitor, and a protective layer made of magnesium oxide (MgO) formed on the dielectric layer. On the other hand, the back plate is a glass substrate, stripe-shaped data electrodes formed on one main surface thereof, a base dielectric layer covering the data electrodes, a partition formed on the base dielectric layer, It is comprised with the fluorescent substance layer which light-emits each in red, green, and blue formed between the partition walls (refer patent document 1).

Japanese Unexamined Patent Publication No. 2000-67759

  In recent years, the definition of television has been increased, and the market demands a PDP having high luminance and low power consumption, that is, high luminous efficiency. However, since the PDP emits light by discharge, there is a problem that when the resolution is increased and the discharge cells are reduced, the sustain discharge voltage during the sustain discharge increases. In reducing the sustain discharge voltage of PDP, the protective layer is one of the key materials, and it is known that the sustain discharge voltage during the sustain discharge can be reduced by enhancing the electron emission characteristics from the protective layer. Conventionally, the material constituting the protective layer is required to have characteristics such as a large secondary electron emission coefficient to reduce the sustain discharge start voltage, excellent spatter resistance and long life. Magnesium oxide (MgO) is used.

  In order to meet the demand for a PDP having high luminous efficiency, conventionally, a display device has been proposed in which a single cesium which is an alkali metal is contained in a protective layer or a cesium layer is formed on the protective layer.

  However, cesium alone is not suitable for PDP because it has conductivity and does not have a so-called memory effect of accumulating wall charges. Further, cesium simple substance and cesium complex oxide have not been put into practical use because they have problems as described below.

  First of all, cesium simple substance and complex oxide of cesium are very active and are immediately oxidized in the atmosphere to cesium hydroxide, so that cesium is scattered in the thermal process of the manufacturing process. Has the problem of process resistance.

  Second, a layer formed of cesium alone or a complex oxide of cesium has a problem that it is very easily sputtered.

  The present invention has been made in view of such problems, and an object of the present invention is to realize a high-definition, high-luminance, low-power-consumption PDP by improving the above-described problems and enabling low-voltage driving.

  In order to achieve the above object, a method of manufacturing a PDP according to the present invention includes a front plate having a protective layer and a rear plate, which are disposed opposite to each other in a discharge space and sealed, and the discharge space is exhausted. The protective layer has a base film and metal oxide particles, the metal oxide particles are magnesium oxide crystals, and the base film has a cesium carbonate composite. Including a material, and after forming the protective layer, the surface of the protective layer is exposed to a reducing organic gas.

  According to the present invention, it is possible to realize a high-definition, high-brightness, low-power-consumption PDP by improving the above problem and enabling low-voltage driving.

Partial perspective view of the PDP of the present invention Partial sectional view of the PDP protective layer of the present invention The figure which shows the change of work function with respect to the cesium density | concentration of a protective layer base film The figure which shows the manufacture flow of the PDP front board of this invention The figure which shows the manufacture flow of PDP of this invention The figure which shows the temperature profile example of this invention The figure which shows the temperature profile example of this invention The figure which shows the temperature profile example of this invention

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing the structure of a PDP according to an embodiment of the present invention. The basic structure of the PDP is the same as that of a general AC surface discharge type PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other, and its outer peripheral portion is sealed with a glass frit or the like. The material is hermetically sealed. The discharge space 16 inside the sealed PDP 1 is filled with discharge gas such as Ne and Xe at a predetermined pressure.

  On the front glass substrate 3 of the front plate 2, a pair of strip-like display electrodes 6 made up of scanning electrodes 4 and sustain electrodes 5 and black stripes (light-shielding layers) 7 are arranged in a plurality of rows in parallel with each other. A dielectric layer 8 serving as a capacitor is formed on the front glass substrate 3 so as to cover the display electrode 6 and the light shielding layer 7, and a protective layer 9 made of magnesium oxide (MgO) is formed on the surface. Has been.

Here, the scan electrode 4 and the sustain electrode 5 are each formed by forming a bus electrode made of Ag on a transparent electrode made of a conductive metal oxide such as ITO, SnO ₂ , or ZnO.

  Further, on the rear glass substrate 11 of the rear plate 10, a plurality of data electrodes 12 made of a conductive material mainly composed of Ag parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Are arranged in parallel to each other, and the underlying dielectric layer 13 covers them. Further, a partition wall 14 having a predetermined height is formed on the underlying dielectric layer 13 between the data electrodes 12 to divide the discharge space 16. A phosphor layer 15 that emits red, green, and blue light by ultraviolet rays is sequentially applied to the data electrode 12 in the groove between the barrier ribs 14. A discharge cell is formed at a position where the scan electrode 4 and the sustain electrode 5 intersect with the data electrode 12, and the discharge cell having red, green, and blue phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. Become a pixel.

  In the present invention, the discharge gas sealed in the discharge space 16 is a discharge gas mixed so that the concentration of xenon is 10% or more and 30% or less in the discharge gas.

In particular, the front plate 2 will be described. On the front glass substrate 3 manufactured by the float process or the like, the display electrode 6 and the light shielding layer 7 including the scanning electrode 4 and the sustain electrode 5 are patterned. Scan electrode 4 and sustain electrode 5 are each composed of a transparent electrode made of indium tin oxide (ITO), tin oxide (SnO ₂ ), or the like, and a metal bus electrode formed on the transparent electrode. The metal bus electrode is used for the purpose of imparting conductivity in the longitudinal direction of the transparent electrode, and is formed of a conductive material mainly composed of a silver (Ag) material.

  The dielectric layer 8 is provided so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 formed on the front glass substrate 3, and further a protective layer 9 is formed on the dielectric layer 8. .

  Next, a method for manufacturing a PDP will be described. First, the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 are formed on the front glass substrate 3. The transparent electrodes and the metal bus electrodes of the scan electrode 4 and the sustain electrode 5 are formed by patterning using a photolithography method or the like. The transparent electrode is formed using a thin film process or the like, and the metal bus electrode is solidified by baking a paste containing a silver (Ag) material at a desired temperature. Similarly, the light-shielding layer 7 is formed by screen printing a paste containing a black pigment or by forming a black pigment on the entire surface of the glass substrate, and then patterning and baking using a photolithography method.

  Next, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7, thereby forming a dielectric paste layer (dielectric material layer). After the dielectric paste is applied, the surface of the applied dielectric paste is leveled by leaving it to stand for a predetermined time, so that a flat surface is obtained. Thereafter, the dielectric paste layer is baked and solidified to form the dielectric layer 8 that covers the scan electrode 4, the sustain electrode 5, and the light shielding layer 7. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent. Next, a protective layer 9 made of magnesium oxide (MgO) is formed on the dielectric layer 8 by vacuum deposition or screen printing. Through the above steps, predetermined components (scanning electrode 4, sustaining electrode 5, light shielding layer 7, dielectric layer 8, and protective layer 9) are formed on front glass substrate 3, and front plate 2 is completed.

  On the other hand, the back plate 10 is formed as follows. First, the structure for the data electrode 12 is formed by a method of screen printing a paste containing silver (Ag) material on the rear glass substrate 11 or a method of forming a metal film on the entire surface and then patterning using a photolithography method. A data layer is formed by forming a material layer to be a product and firing it at a desired temperature. Next, a dielectric paste is applied on the back glass substrate 11 on which the data electrodes 12 are formed by a die coating method so as to cover the data electrodes 12 to form a dielectric paste layer. Thereafter, the base dielectric layer 13 is formed by firing the dielectric paste layer. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent.

  Next, a partition wall forming paste including a partition wall material is applied on the base dielectric layer 13 and patterned into a predetermined shape to form a partition wall material layer and then fired to form the partition walls 14. Here, as a method of patterning the partition wall paste applied on the base dielectric layer 13, a photolithography method or a sand blast method can be used. Next, the phosphor layer 15 is formed by applying a phosphor paste containing a phosphor material on the base dielectric layer 13 between the adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14 and baking it. Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

  Thereafter, a glass frit as a sealing member is applied to the outside of the image display area of the back plate 10, and then a frit coating process is performed in which the glass frit is pre-baked at a temperature of about 350 ° C. in order to remove the resin component of the glass frit. . Here, the sealing member is preferably a frit mainly composed of bismuth oxide or vanadium oxide.

  Next, the front plate 2 and the back plate 10 coated with glass frit and baked are arranged so as to face each other so that the scan electrodes 4, the sustain electrodes 5, and the data electrodes 12 are orthogonal to perform sealing. Thereafter, after the gas in the panel is primarily exhausted, a reducing organic gas is introduced into the panel to expose the protective layer 9 of the front plate 2 to the reducing organic gas, and the discharge space 16 includes the reducing organic gas. The PDP 1 is completed by performing a sealing exhaust process of exhausting the internal gas and enclosing a discharge gas containing Ne, Xe, etc. in the discharge space 16 evacuated.

  Next, the structure and manufacturing method of the protective layer, which is a feature of the PDP according to the embodiment of the present invention, will be described with reference to FIG. In the PDP according to the embodiment of the present invention, as shown in FIG. 2, the protective layer 9 forms a base film 91 made of a vapor-deposited MgO film on the dielectric layer 8, and in the base film 91. Contains cesium carbonate.

  Alternatively, a base film 91 made of a crystal particle layer having an average particle diameter of MgO of 10 nm to 100 nm is formed on the dielectric layer 8, and a carbonized composite material of cesium is contained in the base film 91.

The cesium carbonate or carbonated composite material forming the protective layer 9 is Cs ₂ CO ₃ or CsCO _3x (A _y O _z ). Here, A consists of one or more elements selected from Y, Ce, and La.

  Regarding the production method, cesium carbonate is dissolved in a solvent and applied onto the deposited MgO by spraying, slit coating or the like. Alternatively, the carbonized composite material of cesium is mixed and applied to the MgO paste by a screen printing method.

  On the base film 91, MgO crystal particles 92a, which are metal oxides, agglomerated particles 92 in which several crystal particles 92b smaller than the crystal particles 92a are aggregated, and cubic crystals of MgO, which are metal oxides. A plurality of particles 93 are dispersed and adhered so as to be uniformly distributed over the entire surface.

  Further, in the present invention, in the aggregated particles 92 in which several MgO crystal particles 92a and several crystal particles 92b are aggregated, the crystal particles 92a are particles having an average particle size in the range of 0.9 μm to 2 μm. The MgO crystal particles 92b having a small average particle diameter are particles having an average particle diameter in the range of 0.3 μm to 0.9 μm.

  The cubic crystal particles 93 of MgO include particles having a particle size larger than 100 nm and nanoparticles having a particle size of 100 nm or less. When the actually produced panel is observed, the cubic shape of MgO is observed. MgO polyhedral crystal particles 92a or polyhedral crystal particles 92b, or polyhedral crystal particles 92a and 92b aggregated particles 92, and MgO cubic crystal particles. Some had 93 attached. Furthermore, MgO polyhedral crystal particles 92a and 92b are produced by a liquid phase method, and MgO cubic crystal particles 93 are produced by a gas phase method.

  Here, the agglomerated particles 92 are those in which crystal particles 92a and 92b having a predetermined primary particle diameter are agglomerated or necked, and are not bonded with a large binding force as a solid, but are charged with static electricity or van der. A plurality of primary particles form an aggregate body due to the Waals force, etc., and are joined to such a degree that some or all of them become primary particles due to external stimuli such as ultrasonic waves. . The particle diameter of the agglomerated particles 92 is about 1 μm, and the crystal particles 92a and 92b have a polyhedral shape having seven or more faces such as a tetrahedron and a dodecahedron.

  The MgO crystal particles 92a and 92b are prepared by a liquid phase method in which a MgO precursor solution such as magnesium carbonate or magnesium hydroxide is prepared and fired. Crystal particles having a shape can be obtained. The particle size can be controlled by controlling the firing temperature and firing atmosphere by this liquid phase method. Generally, the firing temperature can be selected in the range of about 700 to 1500 degrees, but the primary particle size can be controlled to about 0.3 to 2 μm by setting the firing temperature to a relatively high 1000 degrees or more. . Further, the crystal particles 92a and 92b are obtained by a liquid phase method. By obtaining the MgO precursor by heating, the primary particles are aggregated by a phenomenon called aggregation or necking in the generation process. Particles 92 can be obtained.

  Next, the results of experiments conducted to confirm the effect of the PDP having the protective layer according to the present invention will be described. When the PDP is driven as described above, the protective layer formed of cesium carbonate or a carbonated composite material has a low work function and a higher secondary electron emission coefficient than that formed of MgO. In addition, it stably operates as a protective layer of the PDP, whereby the sustain discharge voltage generated in the discharge space is stably reduced.

  In general, the stronger the ionicity of the crystal, the easier the compound emits electrons, and the secondary electron emission coefficient tends to increase, which correlates with an increase in the electric dipole. In the case of two pairs of simple anions and cations, the dipole is expressed as (difference between two pairs of electronegativity) × (sum of two pairs of ionic radii).

  Cesium is the element with the lowest electronegativity (0.7 Pauling's) among the known elements, has the property of being very easy to emit electrons, and has a relatively large ionic radius and electric dipole. Is advantageous. As an element to be paired, an element having a high electronegativity is preferable, but as an element satisfying this, for example, oxygen (3.5 Pauling's), chlorine (3 Pauling's), fluorine (4 Pauling's), nitrogen (3 Pauling's), carbon (2.5 Pauling's), sulfur (2.5 Pauling's), bromine (2.8 Pauling's), iodine (2.5 Pauling's) and the like. Here, it is known that a layer formed of a crystal containing oxygen stably operates as a protective layer of the PDP.

  However, as mentioned above, Cs-based materials have problems of process resistance and sputtering resistance. Therefore, the inventors have invented a carbonated composite material in which hydroxylation is suppressed for process resistance, and for the spatter resistance, a structure in which cesium carbonate or carbonated composite material is included in the base film. Solved the problem.

  From the above, the protective layer 9 has a structure in which cesium carbonate and cesium carbonate composite material are included in the base film, so that it has stable reduction of sustain discharge voltage, process resistance, and sputtering resistance in the PDP. Is possible.

FIG. 3 shows the electron emission performance of the protective layer formed of the carbonated composite material and MgO invented this time by measuring the work function by ultraviolet photoelectron spectroscopy (UPS). The electron emission performance is a numerical value indicating that the work function is low and the electron emission performance is high as the energy value at which electrons start to be emitted is small, and the sustain discharge voltage decreases. As a result, it was found that if the MgO underlayer contains Cs ₂ O at a concentration of 0.1%, the energy at which electrons start to be emitted is lower than that of MgO, and the electron emission performance is high.

  Therefore, it can be seen that inclusion of Cs of the above concentration or more in the base film contributes to stable reduction of the sustain discharge voltage in the PDP.

  In addition, MgO used in the conventional PDP has a wide band gap and hardly generates electron emission from Xe ions, but cesium oxide generates electron emission from Xe ions. A higher Xe ion concentration is preferred.

  Further, the PDP has a protective layer 9 made of cesium carbonate or cesium carbonate composite material, and its secondary electron emission coefficient is larger than that of a conventional protective layer made of MgO. When the same number of ions are incident as compared with the conventional protective layer formed, the amount of emitted electrons is increased, energy loss is reduced, and luminous efficiency is improved.

  In addition, in the conventional PDP having a protective layer formed of MgO, the luminous efficiency could be improved by increasing the Xe concentration in the discharge gas or setting the discharge gap between the discharge electrodes to be long. In order to improve the luminous efficiency, there is a problem that the discharge voltage increases.

  In the above PDP, since the protective layer 9 is formed of cesium carbonate or cesium carbonate composite material, the discharge voltage is reduced as described above. Therefore, the discharge voltage is reduced and the luminous efficiency is improved. Can be achieved at the same time.

  The protective layer 9 formed by containing cesium carbonate or cesium carbonate composite material in MgO is more stable in the atmosphere and less resistant to hydroxide than cesium simple substance and cesium composite oxide. It has the feature that it is excellent in performance.

  Next, in the PDP according to the present invention, a manufacturing process of a protective layer constituted by containing a cesium carbonate or a carbonated composite material will be described. For the cesium carbonate, as shown in FIG. 4, after performing the dielectric layer forming step A1 for forming the dielectric layer 8, in the next underlayer deposition step A2, a vacuum using a sintered body of MgO as a raw material A base film made of MgO is formed on the dielectric layer 8 by vapor deposition.

After that, on the unfired base film formed in the base film deposition step A2, MgO crystal particles 92a are aggregated particles 92 and metal oxides in which several crystal particles 92b having a particle diameter smaller than the crystal particles 92a are aggregated. A process of adhering certain MgO cubic crystal particles 93 and CsCO ₃ particles 94, which are cesium carbonate, to the base film is performed.

In this step, first, a crystal particle paste in which polyhedral MgO crystal particles 92a and 92b having a predetermined particle size distribution and MgO cubic crystal particles 93 are mixed in a solvent, and CsCO, which is a cesium carbonate. A crystal particle paste prepared by mixing _three particles 94 in a solvent is prepared separately, and then two kinds of crystal particle pastes are mixed together to produce polyhedral MgO crystal particles 92a and 92b, and MgO cubic crystal particles 93. And CsCO ₃ particles 94, which is a carbonate of Cs, are mixed in a solvent, and the mixed crystal particle paste is applied onto the base film in the crystal particle paste application step A3. As a method for applying the crystal particle paste onto the base film, a spray method, a slit coating method, or the like can also be used.

Here, as an example of the solvent used for the preparation of the crystal particle paste, MgO base film 91, MgO crystal particles 92a and 92b, MgO cubic crystal particles 93, and CsCO ₃ particles 94, which are Cs carbonates. And having a relatively high vapor pressure of several tens of Pa at room temperature to facilitate evaporative removal in the subsequent drying step A4, such as methylmethoxybutanol, terpineol, propylene An organic solvent alone such as glycol or benzyl alcohol or a mixed solvent thereof is used. The viscosity of the paste using these solvents is several mPaS to several tens mPaS.

  The substrate on which the mixed crystal particle paste is coated on the base film is immediately transferred to the drying step A4 and dried under reduced pressure. Since the crystal particle paste is rapidly dried within a few tens of seconds in the vacuum chamber, the convection of the crystal particle paste that is noticeable in heat drying does not occur. To be attached. In addition, as a drying method in this drying step A4, a heat drying method may be used according to a solvent or the like used when producing an aggregate / crystal particle paste.

Thereafter, the unfired base film formed in the base film deposition step A2 and the crystal particle paste film formed in the crystal particle paste application step A3 for forming the crystal particle paste film and subjected to the drying step A4 are fired in the protective layer. In step A5, simultaneous baking is performed at a temperature of several hundred degrees to remove the solvent and the resin component remaining in the crystal particle paste film, whereby a plurality of polyhedral MgO crystal particles 92a and 92b are formed on the base film 91. And a protective layer 9 containing MgO cubic crystal particles 93 and CsCO ₃ particles 94, which are cesium carbonate, in the underlayer.

According to this method, it is possible to uniformly contain Cs ₂ CO ₃ , which is a carbon oxide of Cs, over the entire surface of the base film. In addition to such a method, a method of spraying particle groups directly with a gas or the like without using a solvent or the like, or a method of simply spraying using gravity may be used.

  Next, the manufacturing process of the protective layer formed of the carbonized composite material of cesium will be described. A protective layer in which a carbonated composite material of magnesium oxide and cesium is mixed is formed on the dielectric layer. To form the protective layer, first, a paste is prepared by mixing magnesium oxide containing nanocrystalline particles having an average particle diameter of 10 nm to 100 nm with a cesium carbonate composite material. Nanocrystal particles can be produced by a vapor phase generation method. The vapor phase growth method is a method for producing nano-sized fine particles by instantaneously cooling magnesium vapor evaporated under high energy such as plasma or electron beam with a cooling gas containing oxygen gas (for example, argon gas).

  In this embodiment, carbonation of nanocrystal particles having an average particle size of 50 nm and cesium is carried out in a vehicle prepared by mixing 60% by weight of terpineol, 30% by weight of butyl carbitol acetate and 10% by weight of an acrylic resin. The composite material was kneaded to prepare a paste. And the magnesium oxide paste was apply | coated on the dielectric material layer using well-known techniques, such as a screen printing method, and the precursor of the protective layer was formed.

  Thereafter, the front substrate on which the precursor is formed is dried and fired to form a protective layer having a thickness of 1 μm to 5 μm. In the present embodiment, first, a front substrate coated with a paste in which a carbonated composite material of magnesium oxide and cesium was mixed was held at 350 ° C. for 11 minutes and dried. Thereafter, it was baked while being held at 500 ° C. for 12 minutes to form a protective layer having a thickness of about 2 μm.

In the above description, MgO is taken as an example of the protective layer, but the performance required for the base film is to have a high sputtering resistance for protecting the dielectric from ion bombardment, and has a high charge retention. The capacity, that is, the electron emission performance may not be so high. In conventional PDPs, in order to achieve both the electron emission performance above a certain level and the sputter resistance performance, a protective layer mainly composed of MgO has been formed in many cases. Since the composition is controlled predominantly by the material single crystal particles, there is no need to use MgO, and other materials having excellent impact resistance such as Al ₂ O ₃ may be used.

  In the present embodiment, the description has been made using MgO particles as the crystal particles. However, other single crystal particles are also oxides of metals such as Sr, Ca, Ba, Al and the like having high electron emission performance similar to MgO. Since the same effect can be obtained even if crystal grains are used, the particle type is not limited to MgO.

  By forming the protective layer in this way, a panel having electron emission performance, process resistance, and sputtering resistance can be obtained.

  Next, details of the panel assembly process, which is a feature of the PDP according to the embodiment of the present invention, will be described with reference to FIGS. As shown in FIG. 5, after the front plate 2 and the back plate 10 are produced, the gas containing the reducing organic gas is introduced into the discharge space of the panel until the discharge gas is sealed in the discharge space of the panel. After the introduction and exposure of the protective layer 9 of the front plate 2 to the reducing organic gas, a step of discharging the gas containing the reducing organic gas is provided, and then the discharge gas is sealed in the discharge space. It has been found that the sustain discharge voltage can be reduced, and is characterized in that a reducing gas introduction step C2 is provided in addition to the sealing step C1, the exhaust step C3, and the discharge gas supply step C4.

  6-8 is a figure which shows an example of the temperature profile of the sealing process C1, the reducing gas introduction | transduction process C2, the exhaustion process C3, and the discharge gas supply process C4 used for embodiment of this invention. In the figure, the sealing temperature is a temperature at which the front plate 2 and the rear plate 10 are sealed by a frit as a sealing member in the sealing step C1, and the sealing temperature in the present embodiment. Is about 490 ° C., for example. The exhaust temperature is the temperature in the exhaust process C3, and the exhaust temperature in the present embodiment is about 400 ° C., for example.

  In the example shown in FIG. 6, in the sealing step C <b> 1, after the period of ab to be maintained at the sealing temperature, in the period of bc in which the temperature is decreased from the sealing temperature to the exhaust temperature, from the discharge space of the panel. After exhausting the gas and reducing the pressure, the protective layer 9 is reduced by introducing a gas containing a reducing organic gas into the discharge space of the panel during the period cd maintained at the exhaust temperature. The reducing gas introduction process C2 is performed by exposing to a gas containing a reducing organic gas, and then the exhausting process C3 for exhausting the gas from the discharge space of the panel including the reducing organic gas is performed during the period d-e. A discharge gas supply step C4 for supplying a discharge gas into the discharge space is performed in a period after the point e that has dropped to about room temperature.

  In the example shown in FIG. 7, in the sealing step C <b> 1, after elapse of the period ab in which the sealing temperature is maintained, d <b> 1 that is maintained at the exhaust temperature from the point c that is decreased from the sealing temperature to the exhaust temperature. In the period, after exhausting the gas from the discharge space of the panel and reducing the pressure, the gas containing the reducing organic gas in the discharge space of the panel in the period d1-d2 while maintaining the exhaust temperature. Then, a reducing gas introduction step C2 is performed in which the protective layer 9 is exposed to a gas containing a reducing organic gas, and then the gas is exhausted from the discharge space of the panel including the reducing organic gas during the period d2-e. The discharge process C3 is performed, and the discharge gas supply process C4 for supplying the discharge gas into the discharge space is performed in the period after the point e when the temperature drops to about room temperature.

  Further, in the example shown in FIG. 8, in the sealing step C1, the gas is exhausted from the discharge space of the panel during the period b1 during the period of maintaining the sealing temperature from the point a reaching the sealing temperature. In the discharge space of the panel in the period of point c after the period of b2 that has been maintained at the sealing temperature from the point b1 and after the period of b2 is decreased from the sealing temperature to the exhaust temperature. A reducing gas introduction step C2 is performed in which a gas containing a reducing organic gas is introduced to expose the protective layer 9 to a gas containing the reducing organic gas. Thereafter, in the period of c-e, the reducing organic gas is included in the panel. The exhaust process C3 for exhausting the gas from the discharge space is performed, and the discharge gas supply process C4 for supplying the discharge gas into the discharge space is performed in a period after the point e when the temperature is lowered to about room temperature.

  Here, as the reducing organic gas used in the present invention, as shown in Table 1, a CH-based organic gas having a molecular weight of 58 or less and a large reducing power is desirable, and a reducing organic gas selected from these reducing organic gases is used. A reducing organic gas is mixed with a rare gas or nitrogen gas to produce a gas containing a reducing organic gas, and the reducing gas introduction step C2 is performed.

  In Table 1, column C means the number of carbon atoms contained in one molecule of organic gas. The column of H means the number of hydrogen atoms contained in one molecule of the organic gas.

  As shown in Table 1, “A” is given to a gas having a vapor pressure of 100 kPa or higher at 0 ° C. in the vapor pressure column. Furthermore, “C” is given to the gas whose vapor pressure at 0 ° C. is smaller than 100 kPa. In the boiling point column, a gas having a boiling point of 0 ° C. or less at 1 atm is marked with “A”. Furthermore, “C” is attached to a gas having a boiling point of greater than 0 ° C. at 1 atmosphere. In the column for easy decomposition, “A” is given to the gas that is easily decomposed. “B” is attached to a gas that is easily decomposed. In the column of reducing power, “A” is given to the gas having sufficient reducing power.

  In Table 1, “A” means good characteristics. “B” means normal characteristics. “C” means insufficient properties.

  From the viewpoint of easy handling of organic gas in the manufacturing process of PDP, a reducing organic gas that can be supplied in a gas cylinder is desirable. Also, considering the ease of handling in the manufacturing process of PDP, a reducing organic gas having a vapor pressure at 100 ° C. of 100 kPa or higher, a reducing organic gas having a boiling point of 0 ° C. or lower, or a reducing organic gas having a low molecular weight is present. desirable.

  Furthermore, part of the gas containing the reducing organic gas may remain in the discharge space even after the exhaust process C3. Therefore, it is desirable that the reducing organic gas has a characteristic that it is easily decomposed.

  Reducing organic gas is a carbon that does not contain oxygen selected from acetylene, ethylene, methylacetylene, propadiene, propylene and cyclopropane, taking into consideration the ease of handling in the manufacturing process and the property of being easily decomposed. Hydrogen gas is desirable.

  At least one selected from these reducing organic gases may be mixed with a rare gas or nitrogen gas. The lower limit of the mixing ratio of the rare gas or nitrogen gas and the reducing organic gas is determined according to the combustion ratio of the reducing organic gas to be used. The upper limit is about several volume%. If the mixing ratio of the reducing organic gas is too high, the organic component is likely to be polymerized to become a polymer. In this case, the polymer remains in the discharge space and affects the characteristics of the PDP. Therefore, it is preferable to appropriately adjust the mixing ratio according to the component of the reducing organic gas to be used.

  The inventors conducted a similar study using hydrogen gas as another example of the reducing gas, but did not achieve the same effect as the reducing organic gas.

  Note that MgO, CaO, SrO, BaO, and the like are highly reactive with impurity gases such as water, carbon dioxide, and hydrocarbons. In particular, by reacting with water and carbon dioxide, the discharge characteristics are likely to deteriorate, and the discharge characteristics of each discharge cell are likely to vary.

  Therefore, in the sealing step C1, it is preferable to flow an inert gas so that the inside of the discharge space 16 is in a positive pressure state through a through-hole opened in the discharge space 16, and then perform sealing. This is because the reaction between the base film 91 and the impurity gas can be suppressed. Nitrogen, helium, neon, argon, xenon, etc. can be used as the inert gas.

  Moreover, you may flow dry air (dry gas) instead of an inert gas. This is because at least the reaction with water can be suppressed and the production cost can be reduced compared with the inert gas.

  As described above, according to the present invention, the base film 91 is formed on the dielectric layer 8, and the protective film 9 containing cesium carbonate or carbonated composite material is provided in the base film 91. In addition, after the front plate 2 and the back plate 10 are produced and before the discharge gas is sealed in the discharge space of the panel, a gas containing a reducing organic gas is introduced into the discharge space of the panel. After the protective layer 9 of the face plate 2 is exposed to the reducing organic gas, a step of discharging the gas containing the reducing organic gas is provided, and then the discharge gas is enclosed in the discharge space, so that the electron emission performance and the process resistance In addition, it is possible to obtain a PDP having both a high resistance and a sputtering resistance and a reduced sustain discharge voltage.

  In the above description, the protective layer 9 is described as an example in which the aggregated particles 92 in which the MgO crystal particles are aggregated are dispersed and adhered to the base film 91 made of MgO. 91 may be composed of a metal oxide selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO).

  As described above, the present invention is useful for realizing a high-definition, high-brightness, high-image-quality display performance and further realizing a low power consumption PDP.

1 PDP
2 Front plate 3 Front glass substrate 4 Scan electrode 5 Sustain electrode 6 Display electrode 7 Black stripe (light shielding layer)
8 Dielectric layer 9 Protective layer 10 Back plate 11 Back glass substrate 12 Data electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space 91 Base film 92 Aggregated particles 92a, 92b, 93 MgO crystal particles

Claims (5)

A front plate having a display electrode, a dielectric layer, and a protective layer, and a back plate,
The protective layer has a base film and metal oxide particles,
The metal oxide particles are magnesium oxide crystals;
The base film is a layer having a plurality of columnar structures mainly composed of magnesium oxide,
A plasma display panel comprising a carbonized composite material of cesium in a gap between adjacent columnar structures. A method of manufacturing a plasma display panel in which a front plate and a rear plate having a protective layer are formed in a discharge space, and are disposed opposite to each other and sealed, and the discharge space is exhausted.
The protective layer has a base film and metal oxide particles,
The metal oxide particles are magnesium oxide crystals;
The base film is a layer having a plurality of columnar structures mainly composed of magnesium oxide,
Cesium carbonated composite material is included in the gap between adjacent columnar structures;
A method for manufacturing a plasma display panel, wherein a reducing organic gas is exposed to a surface of the protective layer after the protective layer is formed. The cesium carbonated composite material is represented by a general formula CsCO _3x (A _y O _z ), and A is composed of one or more elements selected from at least Y, Ce, and La. The manufacturing method of the plasma display panel of description. The said base film is a manufacturing method of the plasma display panel of Claim 2-3 which has a layer of the magnesium oxide crystal particle with an average particle diameter of 10 nm-100 nm. The method for manufacturing a plasma display panel according to claim 4, wherein the base film has a weight ratio of cesium to magnesium that is greater than 0.1%.

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