WO2011114662A1

WO2011114662A1 - Plasma display panel

Info

Publication number: WO2011114662A1
Application number: PCT/JP2011/001393
Authority: WO
Inventors: 正範三浦; 卓司辻田; 後藤　真志
Original assignee: パナソニック株式会社
Priority date: 2010-03-17
Filing date: 2011-03-10
Publication date: 2011-09-22

Abstract

Aggregates (92), in which a plurality of magnesium oxide crystal particles (92a) are aggregated, and nanocrystal particles are distributed across the complete surface of an underlayer (91) of a protective layer (9) in a plasma display panel. The nanocrystal particles comprise at least two metal oxides selected from a group comprising magnesium oxide, calcium oxide, strontium oxide and barium oxide. The diffraction angle peak of the nanocrystal particles in X-ray diffraction analysis for a specific orientation plane is in between, among two of the metal oxides contained in the nanocrystal particles, the diffraction angle peak of one of the metal oxides contained in the nanocrystal particles in X-ray diffraction analysis for a specific orientation plane, and the diffraction angle peak of another metal oxide in X-ray diffraction analysis for a specific orientation plane.

Description

Plasma display panel

The present invention relates to a plasma display panel used for a display device or the like.

Plasma display panels (hereinafter referred to as PDPs) are capable of realizing high definition and large screens, so 100-inch class televisions have been commercialized. In recent years, PDP has been applied to high-definition televisions that have more than twice the number of scanning lines compared to the conventional NTSC system. In response to energy problems, efforts to further reduce power consumption and environmental issues There is also a growing demand for PDPs that do not contain lead components in consideration of the above.

The PDP is basically composed of a front plate and a back plate. The front plate is a glass substrate of sodium borosilicate glass produced by the float process, a display electrode composed of a striped transparent electrode and a bus electrode formed on one main surface of the glass substrate, A dielectric layer that covers the display electrode and functions 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 address electrodes formed on one main surface thereof, a base dielectric layer covering the address electrodes, a partition formed on the base dielectric layer, The phosphor layer is formed between the barrier ribs and emits red, green and blue light.

The front plate and the back plate are hermetically sealed with their electrode forming surfaces facing each other, and a discharge gas of neon (Ne) -xenon (Xe) is 400 Torr to 600 Torr (5.3 ×) in a discharge space partitioned by a partition wall. 10 ⁴ Pa to 8.0 × 10 ⁴ Pa). PDP discharges by selectively applying a video signal voltage to the display electrodes, and the ultraviolet rays generated by the discharge excite each color phosphor layer to emit red, green, and blue light, thereby realizing color image display is doing.

In addition, such a PDP driving method includes an initialization period in which wall charges are adjusted so that writing is easy, a writing period in which writing discharge is performed according to an input image signal, and a discharge space in which writing is performed. A driving method having a sustain period in which display is performed by generating a sustain discharge is generally used. A period (subfield) obtained by combining these periods is repeated a plurality of times within a period (one field) corresponding to one frame of an image, thereby performing PDP gradation display.

In such a PDP, the role of the protective layer formed on the dielectric layer of the front plate is to protect the dielectric layer from ion bombardment due to discharge and to emit initial electrons for generating address discharge. Etc. Protecting the dielectric layer from ion bombardment plays an important role in preventing an increase in discharge voltage, and emitting initial electrons for generating an address discharge is an address discharge error that causes image flickering. It is an important role to prevent.

In order to increase the number of initial electrons emitted from the protective layer and reduce image flickering, for example, an example of adding impurities to the magnesium oxide (MgO) protective layer, or magnesium oxide (MgO) particles to magnesium oxide (MgO) ) An example formed on a protective layer is disclosed (for example, see

Patent Documents

1, 2, 3, 4, 5, etc.).

In recent years, the definition of television has been increased, and the market demands a full HD (high definition) (1920 × 1080 pixels: progressive display) PDP with low cost, low power consumption, and high brightness. Since the electron emission characteristics from the protective layer determine the image quality of the PDP, it is very important to control the electron emission characteristics.

That is, in order to display a high-definition image, the number of pixels to be written increases even though the time of one field is constant. Therefore, in the writing period in the subfield, the pulse applied to the address electrode It is necessary to reduce the width. However, since there is a time lag called discharge delay from the rise of the voltage pulse to the occurrence of discharge in the discharge space, if the pulse width is narrowed, the probability that the discharge can be completed within the writing period is lowered. . As a result, lighting failure occurs, and the problem of deterioration in image quality performance such as flickering occurs.

Further, for the purpose of improving the luminous efficiency by discharge for reducing power consumption, the content of xenon (Xe), which is one component of the discharge gas contributing to the light emission of the phosphor, in the entire discharge gas is also increased. As the discharge voltage becomes higher, the discharge delay becomes larger, resulting in a problem that the image quality is deteriorated such as lighting failure.

As described above, in order to advance the high definition and low power consumption of the PDP, it is necessary to simultaneously realize that the discharge voltage is not increased and that the image quality is improved by reducing defective lighting. There was a problem.

Attempts have been made to improve the electron emission characteristics by mixing impurities in the protective layer. However, when the electron emission characteristics are improved by mixing impurities in the protective layer, when the charge is accumulated on the surface of the protective layer and used as a memory function, the attenuation rate at which the charge decreases with time increases. Therefore, it is necessary to take measures such as increasing the applied voltage to suppress this.

On the other hand, in the example in which magnesium oxide (MgO) crystal particles are formed on the magnesium oxide (MgO) protective layer, it is possible to reduce the discharge delay and reduce the lighting failure, but it is not possible to reduce the discharge voltage. There was a problem.

JP 2002-260535 A Japanese Patent Laid-Open No. 11-339665 JP 2006-59779 A JP-A-8-236028 JP-A-10-334809

The PDP of the present invention includes a front plate and a back plate disposed opposite to the front plate. The front plate includes a dielectric layer and a protective layer covering the dielectric layer. A base dielectric layer; a plurality of barrier ribs formed on the base dielectric layer; and a phosphor layer formed on the base dielectric layer and on the side surfaces of the barrier ribs. In this base layer, aggregated particles and nanocrystal particles in which a plurality of crystal particles of magnesium oxide are aggregated are dispersed and arranged over the entire surface, and the nanocrystal particles include magnesium oxide and calcium oxide. , Strontium oxide, and barium oxide, and at least two metal oxides selected from the group consisting of two diffraction angle peaks of X-ray diffraction analysis in a specific orientation plane of the nanocrystalline particles. One of the metal oxides There between the diffraction angle peaks of X-ray diffraction analysis in a particular orientation plane of the metal oxide, between the diffraction angle peaks of X-ray diffraction analysis in a particular orientation plane of the other metal oxides.

According to such a configuration, the discharge start voltage is reduced even when the xenon (Xe) gas partial pressure of the discharge gas is increased in order to improve the secondary electron emission characteristics in the protective layer and increase the luminance. Furthermore, it is possible to realize a PDP with excellent display performance that reduces discharge delay and does not cause defective lighting even in high-definition image display, and can realize high-luminance and low-voltage drive even in high-definition images. Can do.

FIG. 1 is a perspective view showing a structure of a PDP according to an embodiment. FIG. 2 is a cross-sectional view showing the configuration of the front plate of the PDP. FIG. 3 is a sectional view showing another configuration example of the front plate of the PDP. FIG. 4 is a diagram showing an X-ray diffraction result in the underlayer of the PDP. FIG. 5 is a diagram showing an X-ray diffraction result in the base layer having another configuration of the PDP. FIG. 6 is an enlarged view for explaining the aggregated particles of the PDP. FIG. 7 is a diagram showing the relationship between the discharge delay of the PDP and the calcium (Ca) concentration in the protective layer. FIG. 8 is a diagram showing the results of examining the electron emission performance and the lighting voltage of the PDP. FIG. 9 is a characteristic diagram showing the relationship between the particle size of the crystal particles used in the PDP and the electron emission performance.

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

FIG. 1 is a perspective view showing a structure of a PDP in one embodiment. The basic structure of the PDP 1 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. In the discharge space 16 inside the sealed PDP 1, discharge gases such as xenon (Xe) and neon (Ne) are applied at a pressure of 400 Torr to 600 Torr (5.3 × 10 ⁴ Pa to 8.0 × 10 ⁴ Pa). It is enclosed.

On the front glass substrate 3 of the front plate 2, a pair of strip-shaped display electrodes 6 each composed of a scanning electrode 4 and a sustain electrode 5 and a plurality of black stripes (light shielding layers) 7 are arranged in parallel to each other. A dielectric layer 8 is formed on the front glass substrate 3 so as to cover the display electrodes 6 and the light-shielding layer 7 so as to hold charges and function as a capacitor. A protective layer 9 is further formed thereon. .

On the back glass substrate 11 of the back plate 10, a plurality of strip-like address electrodes 12 are arranged in parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Layer 13 is covering. Further, a partition wall 14 having a predetermined height is formed on the base dielectric layer 13 between the address electrodes 12 to divide the discharge space 16. In each groove between the barrier ribs 14, a phosphor layer 15 that emits red, green, and blue light by ultraviolet rays is sequentially applied. A discharge space 16 is formed at a position where the scan electrode 4 and the sustain electrode 5 and the address electrode 12 intersect, and the discharge space 16 having the red, green, and blue phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. It becomes a pixel for.

FIG. 2 is a cross-sectional view showing the configuration of the front plate of the PDP in one embodiment. 2 is shown upside down from FIG. As shown in FIG. 2, a display electrode 6 and a light shielding layer 7 including scanning electrodes 4 and sustain electrodes 5 are formed in a pattern on a front glass substrate 3 manufactured by a float method or the like. Scan electrode 4 and sustain electrode 5 are made of

transparent electrodes

4a and 5a made of indium tin oxide (ITO), tin oxide (SnO ₂ ), etc., and

metal bus electrodes

4b and 5b formed on

transparent electrodes

4a and 5a, respectively. It is comprised by. The

metal bus electrodes

4b and 5b are used for the purpose of imparting conductivity in the longitudinal direction of the

transparent electrodes

4a and 5a, and are formed of a conductive material whose main component is a silver (Ag) material.

The dielectric layer 8 includes a first dielectric layer 81 provided on the front glass substrate 3 so as to cover the

transparent electrodes

4a and 5a, the

metal bus electrodes

4b and 5b, and the light shielding layer 7, and a first dielectric. The second dielectric layer 82 formed on the layer 81 has at least two layers, and the protective layer 9 is formed on the second dielectric layer 82.

The protective layer 9 is a metal composed of at least two oxides selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO) formed on the dielectric layer 8. The base layer 91 is made of oxide nanoparticles, and the aggregated particles 92 are formed by aggregating a plurality of magnesium oxide (MgO) crystal particles 92 a on the base layer 91. The metal oxide nanocrystal particles have an average particle size of 10 nm or more and 100 nm or less, and the average particle size of the aggregated particles 92 made of magnesium oxide is 0.9 μm or more and 2.5 μm or less.

FIG. 2 shows an example in which agglomerated particles 92 in which a plurality of magnesium oxide (MgO) crystal particles 92a are agglomerated are attached to an underlayer 91 made of nanocrystalline particles. As shown in FIG. You may form the particle layer 93 which has the aggregated particle 92 in the layer of the base layer 91 which consists of nanocrystal particles.

Next, a method for manufacturing such a PDP 1 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.

Transparent electrodes

4a and 5a and

metal bus electrodes

4b and 5b constituting scan electrode 4 and sustain electrode 5 are formed by patterning using a photolithography method or the like. The

transparent electrodes

4a and 5a are formed using a thin film process or the like, and the

metal bus electrodes

4b and 5b are solidified by baking a paste containing a silver (Ag) material at a predetermined temperature. Similarly, the light shielding layer 7 is also 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 (dielectric material) layer is formed by applying a dielectric paste on the front glass substrate 3 by a die coating method or the like so as to cover the scanning electrode 4, the sustain electrode 5 and the light shielding layer 7. 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 formed by baking and solidifying the dielectric paste layer to cover 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 base layer 91 is formed on the dielectric layer 8. The underlayer 91 is made of metal oxide nanocrystal particles made of at least two oxides selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). Use the membrane used. By using such particles, there is an accompanying effect that the adsorption of the impurity gas to the deposited film protective layer can be greatly reduced. The metal oxide nanocrystal particles can be obtained, for example, by a gas phase synthesis method. In an atmosphere filled with an inert gas, two or more metal materials selected from magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba) are simultaneously heated and sublimated to increase the temperature. When oxygen gas is introduced so as to form a gas region and wrap around the high-temperature gas region, it is instantaneously cooled at the interface between the high-temperature gas region and the oxygen gas introduction region, and metal oxide particles can be produced.

Next, the agglomerated particles 92 of the magnesium oxide (MgO) crystal particles 92a deposited on the base layer 91 will be described. These crystal particles 92a can be manufactured by any one of the following vapor phase synthesis method or precursor baking method.

In the gas phase synthesis method, a magnesium metal material having a purity of 99.9% or more is heated in an atmosphere filled with an inert gas, and a small amount of oxygen is introduced into the atmosphere to directly oxidize magnesium, thereby oxidizing the material. Magnesium (MgO) crystal particles 92a can be produced.

On the other hand, in the precursor firing method, the crystal particles 92a can be produced by the following method. In the precursor firing method, a magnesium oxide (MgO) precursor is uniformly fired at a high temperature of 700 ° C. or higher, and this is gradually cooled to obtain magnesium oxide (MgO) crystal particles 92a. Examples of the precursor include magnesium alkoxide (Mg (OR) ₂ ), magnesium acetylacetone (Mg (acac) ₂ ), magnesium hydroxide (Mg (OH) ₂ ), magnesium carbonate (MgCO ₂ ), magnesium chloride (MgCl ₂ ). ), Magnesium sulfate (MgSO ₄ ), magnesium nitrate (Mg (NO ₃ ) ₂ ), or magnesium oxalate (MgC ₂ O ₄ ). Depending on the selected compound, it may usually take the form of a hydrate, but such a hydrate may be used.

These compounds are adjusted so that the purity of magnesium oxide (MgO) obtained after firing is 99.95% or more, preferably 99.98% or more. If these compounds contain a certain amount or more of various impurity elements such as alkali metals, B, Si, Fe, and Al, unnecessary interparticle adhesion and sintering occur during heat treatment, and highly crystalline magnesium oxide ( This is because it is difficult to obtain MgO) crystal particles 92a. For this reason, it is necessary to adjust the precursor in advance by removing the impurity element.

Metal oxide nanocrystal particles and magnesium oxide (MgO) crystal particles 92a obtained by any of the above methods are dispersed in a solvent, and the dispersion is sprayed, screen-printed, electrostatically applied, or the like. The surface of the dielectric layer 8 is dispersed and dispersed. Thereafter, the solvent is removed through a drying / firing process, and the metal oxide nanocrystal particles and the magnesium oxide (MgO) crystal particles 92a can be fixed on the surface of the dielectric layer 8. The dispersion of the metal oxide nanocrystal particles and the magnesium oxide (MgO) crystal particles 92a may be performed by dispersing them in the same solvent and applying them simultaneously, or by preparing different dispersions and applying them sequentially. However, either method may be applied.

By such a series of 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 address 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 patterning using a photolithography method after forming a metal film on the entire surface. A material layer to be a material is formed. Thereafter, the address electrode 12 is formed by firing at a predetermined temperature. Next, a dielectric paste is applied on the rear glass substrate 11 on which the address electrodes 12 are formed by a die coating method or the like so as to cover the address 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 barrier rib forming paste containing barrier rib material is applied on the base dielectric layer 13 and dried. Thereafter, an adhesive layer forming paste containing an adhesive layer material is applied onto the dried partition wall forming paste, and patterned into a predetermined shape to form a partition material layer and an adhesive material layer. Then, the partition 14 and the adhesive layer are formed by firing at a predetermined temperature. Here, as a method of patterning the partition wall paste and the adhesive layer forming 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 and baking 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. Further, a glass frit for firmly bonding the front plate 2 and the back plate 10 is formed around the back plate 10. Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

Next, the front plate 2 and the back plate 10 provided with predetermined constituent members are arranged opposite to each other so that the scanning electrodes 4 and the address electrodes 12 are orthogonal to each other and fixed. The fixed front plate 2 and back plate 10 are fired at a temperature not lower than the melting point of the glass frit and the adhesive material layer and not higher than the melting point of the partition wall material layer. Thereby, the front plate 2 and the back plate 10 are bonded to each other with the adhesive layer and the glass frit. Finally, a discharge gas containing xenon (Xe), neon (Ne) and the like is sealed in the discharge space 16 to complete the PDP 1.

Here, the first dielectric layer 81 and the second dielectric layer 82 constituting the dielectric layer 8 of the front plate 2 will be described in detail. The dielectric material of the first dielectric layer 81 is composed of the following material composition. That is, 20% by weight to 40% by weight of bismuth oxide (Bi ₂ O ₃ ), 0.5% by weight to 12% of at least one selected from calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). Contains 0.1% by weight to 7% by weight of at least one selected from molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese dioxide (MnO ₂ ). .

In place of molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), manganese dioxide (MnO ₂ ), copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), cobalt oxide At least one selected from (Co ₂ O ₃ ), vanadium oxide (V ₂ O ₇ ), and antimony oxide (Sb ₂ O ₃ ) may be contained in an amount of 0.1 wt% to 7 wt%.

In addition to the above components, zinc oxide (ZnO) is contained in an amount of 0 to 40% by weight, boron oxide (B ₂ O ₃ ) in an amount of 0 to 35% by weight, and silicon oxide (SiO ₂ ) in an amount of 0 to 4% by weight. A material composition that does not contain a lead component, such as 15 wt% and aluminum oxide (Al ₂ O ₃ ) 0 wt% to 10 wt% may be included.

A dielectric material powder is prepared by pulverizing a dielectric material composed of these composition components with a wet jet mill or a ball mill so that the particle diameter becomes 0.5 μm to 2.5 μm. Next, 55 wt% to 70 wt% of the dielectric material powder and 30 wt% to 45 wt% of the binder component are well kneaded with three rolls to paste for the first dielectric layer 81 for die coating or printing. Is made.

The binder component is ethyl cellulose, terpineol containing 1% to 20% by weight of acrylic resin, or butyl carbitol acetate. In addition, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate and tributyl phosphate are added to the paste as needed, and glycerol monooleate, sorbitan sesquioleate, homogenol (Kao Corporation) as a dispersant. The printing property may be improved as a paste by adding a phosphate ester of an alkyl allyl group, etc.

Next, using this first dielectric layer paste, the front glass substrate 3 is printed by a die coat method or a screen printing method so as to cover the display electrode 6 and dried, and then slightly higher than the softening point of the dielectric material. The first dielectric layer 81 is formed by baking at a temperature of 575 ° C. to 590 ° C.

Next, the second dielectric layer 82 will be described. The dielectric material of the second dielectric layer 82 is composed of the following material composition. That is, bismuth oxide (Bi ₂ O ₃ ) is 11 wt% to 20 wt%, and at least one selected from calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO) is 1.6 wt%. It contains ˜21 wt%, and contains 0.1 wt% ˜7 wt% of at least one selected from molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), and cerium oxide (CeO ₂ ).

In place of molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), and cerium oxide (CeO ₂ ), copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), cobalt oxide (Co ₂ O ₃ ), At least one selected from vanadium oxide (V ₂ O ₇ ), antimony oxide (Sb ₂ O ₃ ), and manganese oxide (MnO ₂ ) may be contained in an amount of 0.1 wt% to 7 wt%.

A dielectric material powder is prepared by pulverizing a dielectric material composed of these composition components with a wet jet mill or a ball mill so that the particle diameter becomes 0.5 μm to 2.5 μm. Next, 55 wt% to 70 wt% of the dielectric material powder and 30 wt% to 45 wt% of the binder component are well kneaded with three rolls to form a second dielectric layer paste for die coating or printing. Make it. The binder component is ethyl cellulose, terpineol containing 1% to 20% by weight of acrylic resin, or butyl carbitol acetate. In the paste, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, and tributyl phosphate are added as plasticizers as needed, and glycerol monooleate, sorbitan sesquioleate, and homogenol (Kao Corporation) as dispersants. The printability may be improved by adding a phosphoric ester of an alkyl allyl group or the like.

Next, using this second dielectric layer paste, printing is performed on the first dielectric layer 81 by screen printing or die coating, followed by drying. Thereafter, a temperature slightly higher than the softening point of the dielectric material is 550 ° C. Bake at 590 ° C.

The film thickness of the dielectric layer 8 is preferably set to 41 μm or less in total of the first dielectric layer 81 and the second dielectric layer 82 in order to ensure visible light transmittance. The first dielectric layer 81 has a bismuth oxide (Bi ₂ O ₃ ) content of the second dielectric layer 82 in order to suppress the reaction of the

metal bus electrodes

4b and 5b with silver (Ag). More than the content of (Bi ₂ O ₃ ), the content is 20 wt% to 40 wt%. Therefore, since the visible light transmittance of the first dielectric layer 81 is lower than the visible light transmittance of the second dielectric layer 82, the film thickness of the first dielectric layer 81 is set to the film thickness of the second dielectric layer 82. It is thinner.

The second dielectric layer 82 is less likely to be colored when the content of bismuth oxide (Bi ₂ O ₃ ) is 11 wt% or less, but bubbles are likely to be generated in the second dielectric layer 82. Therefore, it is not preferable. On the other hand, if the content exceeds 40% by weight, coloration tends to occur, and the transmittance decreases.

Also, as the thickness of the dielectric layer 8 is smaller, the effect of improving the luminance and reducing the discharge voltage becomes more prominent. Therefore, it is desirable to set the thickness as small as possible within the range where the withstand voltage does not decrease. From this point of view, in the present embodiment, the thickness of the dielectric layer 8 is set to 41 μm or less, the first dielectric layer 81 is set to 5 μm to 15 μm, and the second dielectric layer 82 is set to 20 μm to 36 μm.

Next, the material for forming the adhesive layer is described. As a material for forming the adhesive layer, a low melting point material such as frit glass or water glass having a melting point lower than that of the partition wall 14 made of a material having a melting point of 500 ° C. to 600 ° C. is desirable. It is also possible to use a general sealing agent in a UV adhesive or a vacuum apparatus with low hygroscopicity and low outgas.

In the PDP 1 manufactured in this way, even when a silver (Ag) material is used for the display electrode 6, the front glass substrate 3 has little coloring phenomenon (yellowing), and bubbles are generated in the dielectric layer 8. It has been confirmed that the dielectric layer 8 excellent in withstand voltage performance is realized.

Next, in the PDP 1 in the present embodiment, the reason why yellowing and bubble generation are suppressed in the first dielectric layer 81 by these dielectric materials will be considered. That is, by adding molybdenum oxide (MoO ₃ ) or tungsten oxide (WO ₃ ) to dielectric glass containing bismuth oxide (Bi ₂ O ₃ ), Ag ₂ MoO ₄ , Ag ₂ Mo ₂ O ₇ , Ag ₂ are added. It is known that compounds such as Mo ₄ O ₁₃ , Ag ₂ WO ₄ , Ag ₂ W ₂ O ₇ , and Ag ₂ W ₄ O ₁₃ are easily formed at a low temperature of 580 ° C. or lower. In the present embodiment, since the firing temperature of the dielectric layer 8 is 550 ° C. to 590 ° C., silver ions (Ag ⁺ ) diffused into the dielectric layer 8 during firing are the molybdenum oxide in the dielectric layer 8. It reacts with (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), and manganese oxide (MnO ₂ ) to produce a stable compound and stabilize it. That is, since silver ions (Ag ⁺ ) are stabilized without being reduced, they do not aggregate to form a colloid. Accordingly, the stabilization of silver ions (Ag ⁺ ) reduces the generation of oxygen associated with the colloidalization of silver (Ag), thereby reducing the generation of bubbles in the dielectric layer 8.

On the other hand, in order to make these effects effective, in a dielectric glass containing bismuth oxide (Bi ₂ O ₃ ), molybdenum oxide (MoO ₃ ), tungsten oxide (WO ₃ ), cerium oxide (CeO ₂ ), oxidation The content of manganese (MnO ₂ ) is preferably 0.1% by weight or more, more preferably 0.1% by weight or more and 7% by weight or less. In particular, when the amount is less than 0.1% by weight, the effect of suppressing yellowing is small.

That is, the dielectric layer 8 of the PDP 1 in the present embodiment suppresses yellowing and bubble generation in the first dielectric layer 81 in contact with the

metal bus electrodes

4b and 5b made of silver (Ag) material, and the first dielectric High light transmittance is realized by the second dielectric layer 82 provided on the body layer 81. As a result, it is possible to realize a PDP having a high transmittance with very few bubbles and yellowing as the entire dielectric layer 8.

Next, details of the protective layer 9 in the present embodiment will be described.

In PDP 1 according to the present embodiment, as shown in FIG. 2, protective layer 9 is attached to base layer 91 made of metal oxide nanocrystal particles formed on dielectric layer 8 and base layer 91. Aggregated particles 92 are formed by aggregating a plurality of magnesium oxide (MgO) crystal particles 92a. In addition, the metal oxide nanocrystal particle is a metal oxide composed of at least two oxides selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). In the X-ray diffraction analysis, the metal oxide nanocrystal particles have a peak between the minimum diffraction angle and the maximum diffraction angle generated from a single oxide constituting the metal oxide in a specific orientation plane. Like that. That is, the nanocrystal particles include at least two metal oxides selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide, and are subjected to X-ray diffraction analysis in a specific orientation plane of the nanocrystal particles. Among the two metal oxides contained in the nanocrystal particles, the folding angle peak is a diffraction angle peak of X-ray diffraction analysis in a specific orientation plane of one metal oxide, and an X-ray in a specific orientation plane of the other metal oxide. It exists between the diffraction angle peaks of diffraction analysis.

FIG. 4 is a diagram showing an X-ray diffraction result in the PDP underlayer in one embodiment. FIG. 4 also shows the results of X-ray diffraction analysis of magnesium oxide (MgO) alone, calcium oxide (CaO) alone, strontium oxide (SrO) alone, and barium oxide (BaO) alone.

4, the horizontal axis represents the Bragg diffraction angle (2θ), and the vertical axis represents the intensity of the X-ray diffraction wave. The unit of the diffraction angle is shown in degrees when one round is 360 degrees, and the intensity is shown in an arbitrary unit (arbitrary unit). In FIG. 4, the crystal orientation plane, which is a specific orientation plane, is shown in parentheses. As shown in FIG. 4, in the crystal orientation plane (111), the diffraction angle is 32.2 degrees for calcium oxide (CaO) alone, the diffraction angle is 36.9 degrees for magnesium oxide (MgO) alone, and strontium oxide (SrO) alone. Shows a peak at a diffraction angle of 30.0 degrees, and barium oxide (BaO) alone has a peak at a diffraction angle of 27.9 degrees.

In PDP 1 in the present embodiment, at least two oxides selected from magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO) are used as base layer 91 of protective layer 9. It is formed by a layer of metal oxide nanocrystal particles made of a material.

FIG. 4 shows the X-ray diffraction results when the single component constituting the underlayer 91 is two components. That is, the X-ray diffraction result of the base layer 91 formed using magnesium oxide (MgO) and calcium oxide (CaO) alone was formed using point A, magnesium oxide (MgO) and strontium oxide (SrO) alone. The X-ray diffraction result of the underlayer 91 is indicated by point B, and further, the X-ray diffraction result of the underlayer 91 formed using a simple substance of magnesium oxide (MgO) and barium oxide (BaO) is indicated by C point.

That is, the point A is a diffraction angle of 36.9 degrees of the magnesium oxide (MgO) alone, which is the maximum diffraction angle of the single oxide, in the crystal orientation plane (111) as the specific orientation plane, and the oxidation which is the minimum diffraction angle. A peak exists at a diffraction angle of 36.1 degrees, which is between the diffraction angle of 32.2 degrees of calcium (CaO) alone. Similarly, peaks at points B and C exist at 35.7 degrees and 35.4 degrees between the maximum diffraction angle and the minimum diffraction angle, respectively.

Further, FIG. 5 shows the X-ray diffraction result in the case where the single component constituting the base layer 91 is three or more components, as in FIG. That is, FIG. 5 shows the results when magnesium oxide (MgO), calcium oxide (CaO), and strontium oxide (SrO) are used as the single component, point D, magnesium oxide (MgO), calcium oxide (CaO), and oxidation. The results when barium (BaO) is used are indicated by point E, and the results when calcium oxide (CaO), strontium oxide (SrO) and barium oxide (BaO) are used are indicated by point F.

That is, the point D is a crystal orientation plane (111) as a specific orientation plane, and a diffraction angle of 36.9 degrees of magnesium oxide (MgO) as a maximum diffraction angle of a single oxide and an oxidation level as a minimum diffraction angle. A peak exists at a diffraction angle of 33.4 degrees, which is between the diffraction angle of 30.0 degrees of strontium (SrO) alone. Similarly, peaks at points E and F exist at 32.8 degrees and 30.2 degrees between the maximum diffraction angle and the minimum diffraction angle, respectively.

Therefore, the base layer 91 of the PDP 1 in this embodiment has a specific orientation in the X-ray diffraction analysis of the surface of the base layer 91 of the metal oxide constituting the base layer 91, whether it is a two-component or three-component component. A peak exists between the minimum diffraction angle and the maximum diffraction angle of a peak generated from a single oxide constituting the surface metal oxide. That is, the nanocrystal particles include at least two metal oxides selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide, and are subjected to X-ray diffraction analysis in a specific orientation plane of the nanocrystal particles. Among the two metal oxides contained in the nanocrystal particles, the folding angle peak is a diffraction angle peak of X-ray diffraction analysis in a specific orientation plane of one metal oxide, and an X-ray in a specific orientation plane of the other metal oxide. It exists between the diffraction angle peaks of diffraction analysis.

In the above description, (111) has been described as the crystal orientation plane as the specific orientation plane, but the peak position of the metal oxide is the same as described above even when other crystal orientation planes are targeted.

In calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO), electrons exist in a region where the depth from the vacuum level is shallower than that of magnesium oxide (MgO). Therefore, when the PDP 1 is driven, when electrons existing in the energy levels of calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO) transition to the ground state of the xenon (Xe) ion, Auger It is considered that the number of electrons emitted due to the effect increases as compared with the case of transition from the energy level of magnesium oxide (MgO).

In addition, as described above, the base layer 91 in the present embodiment is configured such that a peak exists between the minimum diffraction angle and the maximum diffraction angle of the peak generated from a single oxide constituting the metal oxide. Yes. As a result of the X-ray diffraction analysis, the metal oxide having the characteristics shown in FIGS. 4 and 5 has its energy level between the single oxides constituting them. Therefore, the energy level of the base layer 91 is also present between the single oxides, and the number of electrons emitted by the Auger effect is considered to be larger than that in the case of transition from the energy level of magnesium oxide (MgO). .

As a result, the base layer 91 can exhibit better secondary electron emission characteristics compared to magnesium oxide (MgO) alone, and as a result, the discharge sustaining voltage can be reduced. Therefore, particularly when the partial pressure of xenon (Xe) as the discharge gas is increased in order to increase the luminance, it is possible to reduce the discharge voltage and realize a low-voltage and high-luminance PDP.

Table 1 shows the structure of the base layer 91 as a result of the sustaining voltage when a mixed gas (Xe, 15%) of 450 Torr of xenon (Xe) and neon (Ne) is sealed in the PDP in the present embodiment. The result of PDP when changing is shown.

The discharge sustaining voltage in Table 1 is expressed as a relative value when the comparative example is 100. The base layer 91 of sample A is a metal oxide made of magnesium oxide (MgO) and calcium oxide (CaO). The base layer 91 of sample B is a metal oxide made of magnesium oxide (MgO) and strontium oxide (SrO). The underlayer 91 is a metal oxide made of magnesium oxide (MgO) and barium oxide (BaO). The underlayer 91 of the sample D is a metal oxide made of magnesium oxide (MgO), calcium oxide (CaO), and strontium oxide (SrO). The underlayer 91 of sample E is composed of a metal oxide made of magnesium oxide (MgO), calcium oxide (CaO), and barium oxide (BaO). The comparative example shows a case where the base layer 91 is made of magnesium oxide (MgO) alone by an electron beam evaporation method.

When the partial pressure of the discharge gas xenon (Xe) is increased from 10% to 15%, the luminance increases by about 30%. However, in the comparative example in which the underlying layer 91 is made of magnesium oxide (MgO) alone, the discharge is maintained. The voltage increases about 10%.

On the other hand, in the PDP 1 in the present embodiment, the discharge sustain voltage can be reduced by about 10% to 20% in all of the sample A, the sample B, the sample C, the sample D, and the sample E as compared with the comparative example. Therefore, the discharge start voltage can be set within the normal operation range, and a high-luminance and low-voltage drive PDP can be realized.

Calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO) are highly reactive by themselves, so that they easily react with impurities, and thus have a problem that the electron emission performance is lowered. It was. However, in this embodiment mode, the structure of these metal oxides reduces the reactivity and forms a crystal structure with few impurities and oxygen vacancies. Therefore, excessive emission of electrons during driving of the PDP is suppressed, and in addition to the effect of achieving both low voltage driving and secondary electron emission performance, the effect of moderate electron retention characteristics is also exhibited. This charge retention characteristic is particularly effective for retaining wall charges stored in the initialization period and preventing a write failure in the write period and performing a reliable write discharge.

Next, the agglomerated particles 92 provided on the underlayer 91 in the present embodiment and agglomerated a plurality of magnesium oxide (MgO) crystal particles 92a will be described in detail. Aggregated particles 92 of magnesium oxide (MgO) have been confirmed to have mainly an effect of suppressing the discharge delay in the write discharge and an effect of improving the temperature dependence of the discharge delay. Therefore, in the present embodiment, the aggregated particles 92 are arranged as an initial electron supply unit required at the time of rising of the discharge pulse by utilizing the property that the advanced initial electron emission characteristics are superior to those of the base layer 91.

It is considered that the discharge delay is mainly caused by a shortage of the amount of initial electrons that are triggered from the surface of the underlayer 91 being discharged into the discharge space 16 at the start of discharge. Therefore, in order to contribute to the stable supply of initial electrons to the discharge space 16, the aggregated particles 92 of magnesium oxide (MgO) are dispersedly arranged on the surface of the underlayer 91. As a result, abundant electrons are present in the discharge space 16 at the rise of the discharge pulse, and the discharge delay can be eliminated. Therefore, such initial electron emission characteristics enable high-speed driving with good discharge response even when the PDP 1 has a high definition. In the configuration in which the metal oxide aggregated particles 92 are disposed on the surface of the underlayer 91, in addition to the effect of mainly suppressing the discharge delay in the write discharge, the effect of improving the temperature dependence of the discharge delay is also obtained.

As described above, the PDP 1 according to the present embodiment includes the base layer 91 that achieves both low voltage driving and charge retention, and the magnesium oxide (MgO) agglomerated particles 92 that have the effect of preventing discharge delay. Therefore, as a whole PDP 1, high-definition PDP can be driven at a high speed with a low voltage, and high-quality image display performance with reduced lighting failure can be realized.

In the present embodiment, the aggregated particles 92 in which a plurality of crystal particles 92a are aggregated are discretely dispersed on the base layer 91, and a plurality of particles are adhered so as to be distributed almost uniformly over the entire surface. Yes. FIG. 6 is an enlarged view for explaining the aggregated particles 92.

The agglomerated particles 92 are those in which crystal particles 92a having a predetermined primary particle size are aggregated or necked as shown in FIG. In other words, it is not bonded as a solid with a large bonding force, but a plurality of primary particles form an aggregate body due to static electricity, van der Waals force, etc., and due to external stimuli such as ultrasound , Part or all of them are bonded to such a degree that they become primary particles. The particle size of the agglomerated particles 92 is about 1 μm, and the crystal particles 92a preferably have a polyhedral shape having seven or more surfaces such as a tetrahedron and a dodecahedron.

Further, the particle size of the primary particles of the crystal particles 92a can be controlled by the generation conditions of the crystal particles 92a. For example, when an MgO precursor such as magnesium carbonate or magnesium hydroxide is calcined and produced, the particle size can be controlled by controlling the calcining temperature and the calcining atmosphere. Generally, the firing temperature can be selected in the range of 700 ° C. to 1500 ° C., but by setting the firing temperature to a relatively high 1000 ° C. or higher, the particle size can be controlled to about 0.3 μm to 2 μm. is there. Furthermore, by obtaining the crystal particles 92a by heating the MgO precursor, a plurality of primary particles are bonded to each other by a phenomenon called agglomeration or necking in the production process, whereby the agglomerated particles 92 can be obtained.

FIG. 7 is a diagram showing the relationship between the discharge delay of the PDP and the calcium (Ca) concentration in the protective layer in one embodiment. Specifically, among the PDP 1, the discharge delay and the calcium (Ca) concentration in the protective layer 9 when using the base layer 91 composed of a metal oxide of magnesium oxide (MgO) and calcium oxide (CaO) Shows the relationship. The base layer 91 is composed of a metal oxide composed of magnesium oxide (MgO) and calcium oxide (CaO), and the metal oxide has a peak of magnesium oxide (MgO) in the X-ray diffraction analysis on the surface of the base layer 91. A peak exists between the diffraction angle at which the peak is generated and the diffraction angle at which the peak of calcium oxide (CaO) is generated.

FIG. 7 shows the case where only the underlayer 91 is used as the protective layer 9 and the case where the aggregated particles 92 are arranged on the underlayer 91, and the discharge delay is caused by calcium (Ca) contained in the underlayer 91. The case where it is not done is shown as a standard.

As is clear from FIG. 7, in the case of only the base layer 91 and the case where the aggregated particles 92 are arranged on the base layer 91, the case of only the base layer 91 increases the calcium (Ca) concentration in the base layer 91. Whereas the discharge delay is increased, the discharge delay can be significantly reduced by disposing the agglomerated particles 92 on the underlayer 91, and the discharge delay is increased even if the calcium (Ca) concentration in the underlayer 91 is increased. It can be seen that there is little increase.

Next, the results of experiments conducted to confirm the effect of the protective layer 9 having the aggregated particles 92 in the present embodiment will be described. First, a PDP having an underlayer 91 having a different structure and aggregated particles 92 provided on the underlayer 91 was made as a trial. Prototype 1 is a PDP in which magnesium oxide (MgO) is formed by an electron beam evaporation method, and a protective layer 9 having only a base layer 91 is formed. Prototype 2 is a magnesium oxide (MgO) doped with impurities such as Al and Si. A PDP in which a protective layer 9 of only the base layer 91 is formed, which is formed by electron beam evaporation, and prototype 3 is magnesium oxide (MgO) on the base layer 91 formed by electron beam evaporation of magnesium oxide (MgO). This is a PDP having a protective layer 9 formed by spraying and adhering only the primary particles of the crystal particles 92a.

On the other hand, the prototype 4 is the PDP 1 in the present embodiment, and the above-described sample A is used as the protective layer 9. That is, the protective layer 9 includes a base layer 91 composed of metal oxide nanocrystal particles of magnesium oxide (MgO) and calcium oxide (CaO), and agglomerated particles 92 obtained by aggregating crystal particles 92 a on the base layer 91. Are attached so as to be distributed almost uniformly over the entire surface. In the X-ray diffraction analysis of the surface of the underlayer 91, the underlayer 91 has a peak between the minimum diffraction angle and the maximum diffraction angle of the peak generated from the single oxide constituting the underlayer 91. ing. That is, the minimum diffraction angle in this case is 32.2 degrees for calcium oxide (CaO), the maximum diffraction angle is 36.9 degrees for magnesium oxide (MgO), and the peak of the diffraction angle of the underlayer 91 is 36.1 degrees. To exist.

These PDPs 1 were examined for their electron emission performance and charge retention performance, and the results are shown in FIG. The electron emission performance is a numerical value indicating that the larger the electron emission amount, the greater the amount of electron emission. The initial electron emission amount can be measured by a method of measuring the amount of electron current emitted from the surface by irradiating the surface with ions or an electron beam. However, the evaluation of the surface of the front plate 2 of the PDP 1 can be performed nondestructively. With difficulty. Therefore, the method described in JP 2007-48733 A was used. That is, among the delay times at the time of discharge, a numerical value called a statistical delay time, which is a measure of the likelihood of occurrence of discharge, is measured, and when the reciprocal is integrated, a numerical value corresponding to the initial electron emission amount is obtained.

Therefore, this numerical value is used for evaluation. The delay time at the time of discharge means the time of discharge delay when the discharge is delayed from the rising edge of the pulse, and the discharge delay is the time when the initial electrons that trigger when the discharge is started are discharged from the surface of the protective layer 9 to the discharge space. It is considered as a main factor that it is difficult to be released into the inside.

For the charge retention performance, a voltage value of a voltage (hereinafter referred to as a Vscn lighting voltage) applied to the scan electrode necessary for suppressing the charge emission phenomenon when the PDP 1 was manufactured was used as an index. That is, a lower Vscn lighting voltage indicates a higher charge retention capability. This makes it possible to use components having a low withstand voltage and a small capacity as the power source and each electrical component when designing the PDP 1. In the current product, an element having a withstand voltage of about 150 V is used as a semiconductor switching element such as a MOSFET for sequentially applying a scanning voltage to the panel, and the Vscn lighting voltage is 120 V or less in consideration of variation due to temperature. It is desirable to keep it at a minimum.

FIG. 8 is a diagram showing the results of examining the electron emission performance and the lighting voltage of the PDP in one embodiment. As is apparent from FIG. 8, the prototype 4 in which the aggregated particles 92 obtained by aggregating the crystal particles 92a of magnesium oxide (MgO) are dispersed on the ground layer 91 in the present embodiment and uniformly distributed over the entire surface is as follows. In the evaluation of the charge retention performance, the Vscn lighting voltage can be reduced to 120 V or lower, and the electron emission performance is much better than that of the prototype 1 in the case of a protective layer made only of magnesium oxide (MgO). be able to.

In general, the electron emission capability and the charge retention capability of the protective layer of PDP 1 are contradictory. For example, it is possible to improve the electron emission performance by changing the film forming conditions of the protective layer, or by forming a film by doping impurities such as Al, Si, and Ba in the protective layer. The Vscn lighting voltage also increases.

In the PDP 1 of the prototype 4 in which the protective layer 9 is formed in the present embodiment, the electron emission capability is 8 times or more compared to the prototype 1 using the protective layer 9 made of only magnesium oxide (MgO). It has the characteristics, and the charge holding ability can be obtained with a Vscn lighting voltage of 120 V or less. Therefore, it is useful for the PDP1 with the increased number of scanning lines and the small cell size due to the high definition, satisfying both the electron emission ability and the charge retention ability, and reducing the discharge delay and good image display. Can be realized.

Next, the particle size of the magnesium oxide (MgO) crystal particles 92a used in the protective layer of the PDP according to this embodiment will be described in detail. In the following description, the particle diameter means an average particle diameter, and the average particle diameter means a volume cumulative average diameter (D50).

FIG. 9 is a characteristic diagram showing the relationship between the particle size of the crystal particles used in the PDP and the electron emission performance in one embodiment. Specifically, in the prototype 4 in the present embodiment described with reference to FIG. 8, it is a characteristic diagram showing an experimental result of examining the electron emission performance by changing the particle size of the crystal particle 92 a. In FIG. 9, the particle diameter of the crystal particle 92 a was measured by observing the crystal particle 92 a with an SEM. As shown in FIG. 9, it can be seen that when the particle size is reduced to about 0.3 μm, the electron emission performance is lowered, and when it is approximately 0.9 μm or more, high electron emission performance is obtained.

Incidentally, in order to increase the number of emitted electrons in the discharge cell, it is desirable that the number of crystal particles 92a per unit area on the base layer 91 is large. However, according to the experiment, the crystal particles 92a are present in the portion corresponding to the top of the partition wall 14 of the back plate 10 that is in close contact with the protective layer 9 of the front plate 2, and thus the top of the partition wall 14 is damaged. For example, the material is placed on the phosphor layer 15. As a result, it has been found that a phenomenon occurs in which the corresponding cell does not normally turn on and off. The phenomenon of the partition wall breakage is unlikely to occur unless the crystal particles 92a are present at the portion corresponding to the top of the partition wall 14, and therefore, the probability of breakage of the partition wall 14 increases as the number of attached crystal particles 92a increases. . From this point of view, when the crystal particle diameter is increased to about 2.5 μm, the probability of partition wall breakage increases rapidly, and when the crystal particle diameter is smaller than 2.5 μm, the probability of partition wall breakage is kept relatively small. be able to.

From the above results, in the PDP 1 according to the present embodiment, if the aggregated particles 92 having a particle size in the range of 0.9 μm to 2 μm are used as the aggregated particles 92, the above-described effects of the present embodiment can be stably obtained. I found out that

As described above, according to the PDP 1 according to the present embodiment, the electron emission performance is high, and the charge holding ability can be obtained with a Vscn lighting voltage of 120 V or less.

In the present embodiment, the description has been made using magnesium oxide (MgO) particles as the crystal particles 92a. However, other single crystal particles have high electron emission performance similar to magnesium oxide (MgO). Since the same effect can be obtained even if crystal particles made of metal oxide such as Ba and Al are used, the particle type is not limited to magnesium oxide (MgO).

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

1 PDP
2 Front plate 3 Front glass substrate 4

Scan electrode

4a, 5a

Transparent electrode

4b, 5b Metal bus electrode 5 Sustain electrode 6 Display electrode 7 Black stripe (light shielding layer)
DESCRIPTION OF SYMBOLS 8 Dielectric layer 9 Protective layer 10 Back plate 11 Back glass substrate 12 Address electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space 81 First dielectric layer 82 Second dielectric layer 91 Base layer 92 Aggregated particle 92a Crystal particles

Claims

A front plate,
A back plate disposed opposite to the front plate,
The front plate has a dielectric layer and a protective layer covering the dielectric layer,
The back plate has a base dielectric layer, a plurality of barrier ribs formed on the base dielectric layer, and a phosphor layer formed on the base dielectric layer and on the side surfaces of the barrier ribs,
The protective layer includes an underlayer formed on the dielectric layer,
In the underlayer, agglomerated particles and nanocrystal particles in which a plurality of magnesium oxide crystal particles are aggregated are dispersed and arranged over the entire surface.
The nanocrystal particles include at least two metal oxides selected from the group consisting of magnesium oxide, calcium oxide, strontium oxide, and barium oxide,
The diffraction angle peak of the X-ray diffraction analysis in the specific orientation plane of the nanocrystal particle has an X-ray diffraction analysis in the specific orientation plane of one of the two metal oxides included in the nanocrystal particle. The plasma display panel is between the diffraction angle peak of X and the diffraction angle peak of X-ray diffraction analysis in the specific orientation plane of the other metal oxide.
The plasma display panel according to claim 1, wherein the aggregated particles are attached on a film made of the nanocrystalline particles.
The plasma display panel according to claim 1, wherein the nanocrystal particles have an average particle size of 10 nm to 100 nm.
2. The plasma display panel according to claim 1, wherein an average particle diameter of the aggregated particles made of magnesium oxide is 0.9 μm or more and 2.5 μm or less.