JP2008293803A - Plasma display panel and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PDP capable of reducing the used amount of a priming particle emitting powder. <P>SOLUTION: The PDP is provided with a pair of substrates arranged opposing each other via a discharge space, a plurality of display electrodes on one substrate and a dielectric layer covering the display electrodes, a priming particle emitting layer on a surface of the dielectric layer contacted with the discharge space, and further a plurality of address electrodes crossing the display electrodes. The priming particle emitting layer is made of a priming particle emitting powder, with the maximum particle size of aggregates being 20 μm or smaller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plasma display panel (hereinafter referred to as “PDP”) and a method for manufacturing the same.

  FIG. 11 is a perspective view showing a configuration of a conventional PDP. The PDP has a structure in which a front substrate assembly 1 and a back substrate assembly 2 are bonded together. In the front substrate assembly 1, a display electrode 3 made of a transparent electrode 3 a and a metal electrode 3 b is disposed on a front substrate 1 a made of a glass substrate, and the display electrode 3 is covered with a dielectric layer 4. A protective layer 5 made of a magnesium oxide layer having a higher secondary electron emission coefficient is formed on the dielectric layer 4. A plurality of address electrodes 6 are arranged on the back side substrate structure 2 on a back side substrate 2a made of a glass substrate so as to be orthogonal to the display electrodes, and a light emitting region is defined between the address electrodes 6 A partition wall 7 is provided, and red, green, and blue phosphor layers 8 are formed in regions separated by the partition wall 7 on the address electrode 6. A discharge gas made of Ne—Xe gas is sealed in an airtight discharge space formed inside the bonded front-side substrate structure 1 and back-side substrate structure 2. Although not shown, the address electrode 6 is covered with a dielectric layer, and the partition wall 7 and the phosphor layer 8 are provided on the dielectric layer. The address electrode 6 may be disposed in the dielectric layer of the front substrate structure so as to intersect the display electrode.

  In such a PDP, a voltage is applied between the address electrode 6 and the display electrode 3 also serving as a scan electrode, thereby generating an address discharge and applying a voltage between the two display electrodes 3 forming a pair. As a result, reset discharge and sustain discharge for display are generated.

  PDP has been put into practical use as a large-sized thin television, and in recent years, high definition has been advanced. As the resolution is increased, the number of pixels increases, and the address operation time for deciding whether to turn on or off the cell increases. In order to suppress an increase in the address operation time, it is necessary to reduce the pulse width of the address discharge voltage (also referred to as an address voltage). However, since the time (discharge delay) from when the voltage is applied to when the discharge occurs varies, the discharge may not occur if the pulse width of the address voltage is too small. In that case, there is a problem in that the cell is not properly lit during the display period, thereby degrading the image quality.

As means for improving the discharge delay of the PDP, there is a method of providing a magnesium oxide (hereinafter referred to as “MgO”) crystal layer on a front substrate (Patent Document 1). As a means for improving the performance of this MgO crystal layer, a means has been proposed in which MgO crystal powder having a grain size of a certain size or larger is used (Patent Document 2).
JP 2006-59780 A JP 2006-147417 A

In general, in MgO crystal powder, (1) since the powder is manufactured at a high temperature, primary particles may sinter in part, or (2) in contact portions between primary particles in air. Aggregates (referred to as secondary particles) are generated due to liquid cross-linking caused by moisture aggregated by capillary action. For example, even with MgO crystal powder having an average particle diameter of 2000 mm, the particle diameter exceeds 20 μm. Aggregates are considered to be generated.
Patent Documents 1 and 2 describe the significance of removing particles having a small particle size contained in MgO crystal powder, but the problems in the case where aggregates having a large particle size are included are examined. It has not been.

  By the way, priming particle emission powder such as MgO crystal powder is generally expensive, and a technique capable of reducing the amount of priming particle emission powder used as much as possible is desired from the viewpoint of cost reduction.

  This invention is made | formed in view of such a situation, and provides PDP which can reduce the usage-amount of priming particle | grain discharge | release powder.

  The PDP according to the present invention is in contact with a pair of substrates opposed to each other through a discharge space, a plurality of display electrodes on one substrate, a dielectric layer covering the display electrodes, and a discharge space on the dielectric layer. A PDP comprising a priming particle emitting layer on a surface and a plurality of address electrodes intersecting with the display electrode, wherein the priming particle emitting layer has a maximum particle size of aggregate of 20 μm or less. It consists of powder.

  The present inventors have intensively studied the problem in the case where a priming particle (hereinafter referred to as “P particle”) discharge powder contains an aggregate having a large particle size, and the aggregate of the P particle discharge powder. It has been found experimentally that the effect of shortening the discharge delay is increased and the probability of electron emission is increased by making the maximum particle size of 20 μm or less. According to the present invention, since the probability of electron emission from the P particle emission powder is increased, a high discharge delay improvement effect can be obtained with a relatively small amount of the P particle emission powder. Can be reduced. In addition, the amount of the dispersion medium used when the P particle release layer is formed by applying or dispersing the P particle release powder in a state dispersed in the dispersion medium can be reduced.

Further, if large aggregates are present on the protective film surface, the discharge characteristics and the like may be adversely affected. This is thought to be due to electric field disturbance, residual gas, etc., but details are unknown.
Hereinafter, various embodiments of the present invention will be exemplified.

  The P particle emission powder may have a maximum particle size of the aggregate of 10 μm or less. In this case, the usage amount of the P particle emission powder can be further reduced.

  A protective layer made of magnesium oxide may be provided on the dielectric layer, and the P particle emission layer may be provided on the protective layer. In this case, the dielectric layer can be more reliably protected.

  The P particle emission powder may be made of magnesium oxide crystal powder (hereinafter referred to as “MgO crystal powder”). In this case, the effect of improving the discharge delay is great.

  The P particle emission powder may be made of MgO crystal powder to which 1 to 10,000 ppm of a halogen element is added. In this case, the effect of improving the discharge delay lasts for a long time. The reason why the improvement effect of the discharge delay lasts for a long time is not necessarily clear, but the added halogen element is replaced with oxygen in the MgO crystal powder, which becomes an electron trap and the electron emission characteristics are improved. Guessed. In addition, since the effect of improving the discharge delay lasts for a long time, the discharge delay when the rest period is long can be effectively suppressed even if the amount is relatively small, leading to cost reduction.

Further, in the present invention, the P particle release layer of the PDP described above is formed by applying or spraying P particle release powder on the surface of the dielectric layer or the surface of the protective layer. The method for producing a PDP is characterized in that it is produced by crushing the agglomerates in the raw material powder of the priming particle emitting powder so that the maximum particle size of the agglomerates is 20 μm or less. Also provide.
As a method of setting the maximum particle size of the aggregates to 20 μm or less, in addition to the pulverization treatment, a classification treatment and a filter treatment method can be considered. There is an advantage that the maintenance cycle becomes relatively long.

The crushing process may be performed by a turbulent impact method. In this case, crushing can be performed quickly and reliably.
The various embodiments shown here can be combined with each other.

  Hereinafter, various embodiments of the present invention will be described with reference to the drawings. The configurations shown in the drawings and the following description are merely examples, and the scope of the present invention is not limited to those shown in the drawings and the following description. In the following embodiments, the description will be given taking a three-electrode surface discharge type PDP as an example.

1. PDP
1A to 1C show the structure of a PDP according to an embodiment of the present invention, FIG. 1A is a front view, and FIGS. 1B and 1C are diagrams respectively. It is II and II-II sectional drawing in 1 (a).
The PDP according to the present embodiment includes a front side substrate assembly 1 and a back side substrate assembly 2 which are disposed to face each other via a discharge space. The front substrate assembly 1 includes a plurality of display electrodes 3 on the front substrate 1a, a dielectric layer 4 covering the display electrodes 3, and a P particle emission layer 15 on a surface in contact with the discharge space on the dielectric layer 4. Is provided. The P particle releasing layer 15 is made of a priming particle emitting powder in which the maximum particle size of the aggregate is 20 μm or less. A protective layer 5 made of magnesium oxide is provided on the dielectric layer 4, and a P particle emission layer 15 is disposed on the protective layer 5.
The back side substrate structure 2 includes a plurality of address electrodes 6 intersecting (preferably orthogonal) to the display electrodes 3 on the back side substrate 1b, a dielectric layer 9 covering the plurality of address electrodes 6, and a dielectric layer 9 Have a partition wall 7 and a phosphor layer 8.
The front side substrate structure 1 and the back side substrate structure 2 are bonded to each other with a sealing material, and a discharge gas (in the airtight discharge space between the front side substrate structure 1 and the back side substrate structure 2 is formed. For example, neon mixed with several percent of xenon) is enclosed.
Hereinafter, each component will be described in detail.

1-1. Substrate, display electrode, dielectric layer, protective layer (front side substrate structure)
The substrate 1a on the front side is not particularly limited, and any substrate known in the art can be used. Specifically, transparent substrates, such as a glass substrate and a plastic substrate, are mentioned.

The display electrode 3 includes, for example, a wide transparent electrode 3a such as ITO or SnO _2, and, for example, Ag, Au, Al, Cu, Cr, and a laminate thereof (for example, Cr / Cu / Cu) for reducing the resistance of the electrode. And a narrow metal electrode 3b made of a Cr laminated structure. The shapes of the transparent electrode 3a and the metal electrode 3b are not particularly limited, and may be a T shape or a ladder shape. The shapes of the transparent electrode 3a and the metal electrode 3b may be the same or different from each other. For example, the transparent electrode 3a may be T-shaped or ladder-shaped, and the metal electrode 3b may be straight. Moreover, the transparent electrode 3a can also be abbreviate | omitted and the display electrode 3 consists only of the metal electrode 3b in this case.

Each of the plurality of display electrodes 3 is paired to form a display line. As an electrode arrangement form, an arrangement in which a non-discharge region (also referred to as a reverse slit) is provided between electrode pairs, and electrodes are arranged at equal intervals Thus, the adjacent electrodes are all arranged in any of the ALIS type arrangements in which the discharge region is formed. The pair includes a scan electrode 3Y used for address discharge with the address electrode and a sustain electrode 3X used for sustain discharge with the scan electrode 3Y.
The dielectric layer 4 can be formed, for example, by applying a low-melting-point glass paste obtained by adding a binder and a solvent to a low-melting-point glass frit on the substrate after the display electrode 3 is formed and baking it. . The dielectric layer 4 may be formed by depositing silicon oxide by CVD or the like on the substrate after the display electrode 3 is formed.
The protective layer 5 is made of a metal (more specifically, divalent metal) oxide such as magnesium oxide, calcium oxide, strontium oxide, or barium oxide, and is preferably made of magnesium oxide. The protective layer 5 is formed by vapor deposition, sputtering, coating, or the like.

1-2. Substrate, address electrode, dielectric layer, barrier rib, phosphor layer (back side substrate structure)
The substrate 2a on the back side is not particularly limited, and any substrate known in the art can be used. Specifically, transparent substrates, such as a glass substrate and a plastic substrate, are mentioned.
The address electrode 6 can be composed of, for example, Ag, Au, Al, Cu, Cr, and a laminated body thereof (for example, a laminated structure of Cr / Cu / Cr).
The dielectric layer 9 can be formed by the same material and method as the dielectric layer 4.
The partition wall 7 can be formed by forming a partition material layer such as a low-melting glass paste on the dielectric layer 9, patterning the partition material layer by sandblasting or the like, and baking it. The partition wall 7 may be formed by other methods. The shape of the partition wall 7 is not limited, and can be, for example, a stripe shape, a meander shape, a lattice shape, or a ladder shape.
For example, the phosphor layer 8 is coated with a phosphor paste containing phosphor powder and a binder in a groove between the adjacent barrier ribs 7 by screen printing or a method using a dispenser, and this is applied to each color (R, G , B) can be repeated and then fired.

1-3. Priming Particle (P Particle) Release Layer The P particle release layer 15 is made of a P particle release powder having a maximum aggregate particle size of 20 μm or less. Hereinafter, the configuration of the P particle emission powder, the production method of the P particle emission powder, and the method of forming the P particle emission layer 15 will be described in detail.

1-3-1. Configuration of P Particle Emission Powder P particle emission powder is a powder that is excited by a past discharge and emits P particles (charged particles such as electrons) for starting discharge, and the type is not particularly limited. . The P particle emission powder usually contains a large number of aggregates, and in this embodiment, the maximum particle size of these aggregates is 20 μm or less (preferably 10 μm or less). In this case, as will be described later, it has been experimentally verified that the effect of shortening the discharge delay is increased and the probability of electron emission is increased. The particle size of the aggregate can be determined by laser diffraction particle size analysis.

  The P particle emission powder is, for example, a metal (more specifically, a divalent metal) oxide crystal powder (for example, MgO crystal powder, calcium oxide crystal powder, oxidation) formed by a vapor phase method described later. Strontium crystal powder or barium oxide crystal powder) or a halogen element added to such crystal powder. Since the metal oxide crystal powder is similar in structure to the MgO crystal powder, it is considered that the same effect can be obtained.

Hereinafter, a case where the P particle emission powder is made of MgO crystal powder will be described.
MgO crystal powder has a characteristic of performing cathodoluminescence emission having a peak in a wavelength range of 200 to 300 nm by irradiation with an electron beam. The MgO crystal powder is preferably in a powder form, and the size and shape are not particularly limited, but the average particle diameter is preferably 0.05 to 10 μm. This is because if the average particle size is too small, the effect of improving the discharge delay is small, and if the average particle size is too large, the P particle emission layer 15 is difficult to be formed uniformly.

The average particle diameter of the MgO crystal powder can be determined according to Equation 1.
Formula 1: Average particle diameter = a / (S × ρ)
(Where a is a shape factor of 6, S is a BET specific surface area determined by a nitrogen adsorption method, and ρ is a true density of magnesium oxide.)
Specifically, the average particle diameter of the MgO crystal powder is, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0 .8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm. The range of the average particle diameter of the MgO crystal powder may be between any two of the numerical values exemplified as the specific average particle diameter.

  Next, the case where the P particle emission powder is made of MgO crystal powder added with a halogen element (hereinafter referred to as “halogen-added MgO crystal powder”) will be described.

  The kind of halogen element added to the halogen-added MgO crystal powder is not particularly limited. The halogen element is composed of one or more of fluorine, chlorine, bromine and iodine, for example. Although it has been confirmed that the effect of improving the discharge delay lasts for a long time in the case of fluorine, it is considered that the same effect can be obtained when halogen other than fluorine is added due to the similarity of the electronic state.

The addition amount of the halogen element is not particularly limited. The addition amount of the halogen element is, for example, 1 to 10000 ppm. As used herein, “ppm” is a weight concentration.
In the reference experiment, it has been confirmed that the same effect can be obtained even if the addition amount of the halogen element is changed in the range of 24 to 440 ppm. Therefore, the effect of the addition amount of the halogen element is not significant. If the amount of addition is in the range of about 1 to 10,000 ppm, it is considered that the effect of improving the discharge delay lasts for a long time. The added amount of the halogen element is, for example, 1, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 250, 300, 350. , 400, 450, 500, 600, 700, 800, 900, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 or 10,000 ppm. The addition amount of the halogen element may be within a range between any two numerical values exemplified here. The addition amount of the halogen element can be measured by combustion-ion chromatography analysis.

  The halogen-added MgO crystal powder preferably has an average particle size of 0.05 to 10 μm. This is because if the average particle size is too small, the effect of improving the discharge delay is small, and if the average particle size is too large, the P particle emission layer 15 is difficult to be formed uniformly.

The average particle diameter of the halogen-added MgO crystal powder can be determined according to the following formula.
Formula: Average particle size = a / (S × ρ)
(Where a is a shape factor of 6, S is a BET specific surface area determined by a nitrogen adsorption method, and ρ is a true density of the halogen-added MgO crystal powder.)
Specifically, the average particle diameter of the halogen-added MgO crystal powder is, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 μm. The range of the average particle diameter of the halogen-added MgO crystal powder may be between any two of the numerical values exemplified as the specific average particle diameter.

1-3-2. Next, a method for producing a P particle emission powder in which the maximum particle size of the aggregate is 20 μm or less will be described.
A method for producing a P particle emitting powder having a maximum particle size of 20 μm or less is not particularly limited. In one example, the P particle emitting powder is an agglomerate in the raw material powder of the P particle emitting powder. The maximum particle size of the agglomerates can be made 20 μm or less (preferably 10 μm or less). In other words, the raw material powder is a P particle emission powder in a state before the crushing treatment. The raw material powder usually contains aggregates having a particle size of more than 20 μm.
In addition to the crushing treatment, a method of reducing the maximum particle size of the aggregate by classification treatment or filter treatment is also conceivable, but according to the crushing treatment, the use efficiency of the raw material powder is increased and the maintenance cycle is relatively long. The advantage of becoming is obtained.

  The crushing treatment can be performed by various methods such as ultrasonic wave, jet mill, bead mill, ball mill or turbulent impact. The turbulent impact method is a method in which high pressure is applied to the liquid to perform crushing treatment. Medialess fine particles such as Nanomizer from Yoshida Kikai Kogyo Co., Ltd. and Ultimateizer from Sugino Machine Co., Ltd. It is possible to implement using an apparatus or the like. When the P particle release layer 15 is formed by dispersing the powder in a dispersion medium, use of a turbulent impact method is optimal. This is because, according to this method, the aggregate can be crushed by passing the liquid once through the apparatus under appropriate conditions, and damage to the primary particles can be minimized. In addition, when the P particle release layer 15 is formed by spraying powder as it is as in the electrostatic coating method, a jet mill is optimal from the viewpoint of contamination and the like.

Hereinafter, a case where the P particle emission powder is made of MgO crystal powder will be described.
The manufacturing method of the MgO crystal powder having the maximum particle size of the aggregate of 20 μm or less is not particularly limited, but in one example, the above-described crushing treatment is performed on the aggregate in the raw material powder manufactured by the following method. It can be manufactured by applying.

  The method for producing the raw material powder of the MgO crystal powder is not particularly limited, but it is preferably produced by a gas phase method in which magnesium vapor and oxygen are reacted. For example, a method described in JP-A No. 2004-182521 Alternatively, it can be produced by the method described in “Materials” November 1987, Vol. 36, No. 410, pages 1157 to 1161, “Synthesis and Properties of Magnesia Powder by Gas Phase Method”. The raw material powder for MgO crystal powder may be purchased from Ube Materials Corporation. The production by the vapor phase method is preferable because a single crystal powder having high purity can be obtained when the raw material powder of the MgO crystal powder is produced by the vapor phase method.

  In the raw material powder produced by the above vapor phase method, (1) the production temperature of the powder is high, so that the primary particles are partially sintered, or (2) the primary particles in the air Aggregates are generated when liquid cross-linking occurs due to moisture aggregated by capillary action at the contact portion of the material, and, for example, even with MgO having an average particle size of 2000 mm, aggregates having a particle size exceeding 20 μm are generated. It is thought that. Therefore, by performing the above-described crushing treatment on the aggregates in the raw material powder, an MgO crystal powder having a maximum particle size of 20 μm or less can be obtained.

Next, the case where the P particle emission powder is made of a halogen-added MgO crystal powder will be described.
The method for producing a halogen-added MgO crystal powder having a maximum particle size of 20 μm or less is not particularly limited, but in one example, the MgO crystal powder and a halogen-containing substance are mixed and fired, and the resulting bulky product is obtained. It can be manufactured by pulverizing the fired product to obtain a raw material powder, and then subjecting the aggregates in the raw material powder to the above-described crushing treatment. MgO crystal powder can be produced by the above gas phase method. Before mixing the MgO crystal powder and the halogen-containing substance, the aggregates in the MgO crystal powder may or may not be crushed. Examples of the halogen-containing substance include magnesium halides (magnesium fluoride and the like) and Al, Li, Mn, Zn, Ca, Ce halides. Firing is preferably performed at 1000 to 1700 ° C. The firing temperature is, for example, 1000, 1100, 1200, 1300, 1400, 1500, 1600 or 1700 ° C. The firing temperature may be within a range between any two values exemplified here. Although the method of pulverizing the fired product is not particularly limited, for example, a method of putting the fired product in a mortar and grinding it with a pestle to form a powder. By this method, a massive baked product becomes powdery, and this powder usually contains aggregates having a particle size of more than 20 μm, and the aggregates are subjected to the above-mentioned crushing treatment. Thus, a halogen-added MgO crystal powder having an aggregate maximum particle size of 20 μm or less can be obtained.

1-3-3. Next, a method for forming the P particle emission layer 15 will be described.
The P particle emission layer 15 can be formed by applying or dispersing P particle emission powder on the surface of the dielectric layer 4 that is in contact with the discharge space. The P particle emitting layer 15 may be formed on the protective layer 5, or may be formed on the dielectric layer 4 by omitting the protective layer 5 or providing an opening in the protective layer 5.

  The thickness and shape of the P particle release layer 15 are not particularly limited. The P particle emission layer 15 may be formed on the entire surface of the display region or only on a part thereof. For example, it may be formed only in a region overlapping the display electrode 3 in a front view or only in a region overlapping the scan electrode 3Y. In this case, it is possible to reduce the usage amount of the P particle emission powder without significantly reducing the effect of improving the discharge delay. Alternatively, it may be formed only in a region overlapping with the metal electrode 3b, or may be formed only in a region overlapping with a non-discharge line (reverse slit) between display electrode pairs where surface discharge does not occur. In this case, a decrease in luminance due to the formation of the P particle emission layer 15 can be suppressed. The P particle emission layer 15 may be formed in a straight shape, or may be formed in an island shape separated for each discharge cell.

  The method for forming the P particle release layer 15 is not particularly limited. The P particle release layer 15 can be formed, for example, by spraying the P particle release powder as it is or in a state dispersed in a dispersion medium toward a surface in contact with the discharge space on the dielectric layer 4. Further, the P particle emission layer 15 may be formed by applying P particle emission powder on the dielectric layer 4 or the protective layer 5 by screen printing. Alternatively, the P particle release layer 15 may be formed by applying a paste or suspension containing the P particle release powder to a portion where the P particle release layer 15 is formed using a dispenser or an inkjet device.

2. Effect verification experiment When the P particle emission layer 15 is formed using a P particle emission powder having a maximum aggregate particle size of 20 μm or less by the following method, the effect of shortening the discharge delay is enhanced and the electron emission is increased. The effect demonstration experiment which shows that a probability becomes high is demonstrated. In this effect demonstration experiment, F-added MgO crystal powder was used as the P particle emission powder.

2-1. Preparation of slurry containing F-added MgO crystal powder First, MgO crystal powder (manufactured by Ube Materials Co., Ltd., trade name: high-purity ultrafine powder magnesia (2000A)) and MgF ₂ (manufactured by Furuuchi Chemical Co., Ltd.) , Purity: 99.99%) were each pulverized and pulverized into powder by using a mortar and pestle.
Next, the aggregated and crushed MgO crystal powder and MgF ₂ were weighed and mixed with a tumbler mixer. At this time, the mixing amount of MgF ₂ was set to 0.1 mol%.
Next, the mixture was fired in the atmosphere at 1450 ° C. for 1 hour.
Next, the obtained fired product was pulverized to obtain a raw material powder of F-added MgO crystal powder.

  Next, the raw material powder of F-added MgO crystal powder is mixed at a rate of 2 g with respect to 1 L of IPA (manufactured by Kanto Chemical Co., Inc., for electronics industry), and crushed with respect to the aggregate in the raw material powder Treatment was performed to prepare a slurry. For the crushing treatment, a nanomizer manufactured by Yoshida Machine Industry Co., Ltd. was used. The pressure applied during the crushing treatment was 50 MPa and 100 MPa. Those subjected to crushing treatment at 50 MPa and 100 MPa are called 50 MPa sample and 100 MPa sample, respectively.

Next, laser diffraction particle size analysis was performed on a sample that has not been crushed (referred to as “comparative sample”), a 50 MPa sample, and a 100 MPa sample. Laser diffraction particle size analysis was performed using a laser diffraction particle size analyzer (model: LS 13 320, manufactured by BECKMAN COULTER). The result of this analysis is shown in the particle size distribution diagram of FIG.
According to FIG. 2, in the comparative sample, the number of particles (aggregates) having a particle diameter of 20 μm is the largest, and the particles exist up to a size of 50 μm. On the other hand, in the 50 MPa sample and the 100 MPa sample, the mode particle size was 1-2 μm and the maximum particle size was 10 μm or less.
According to FIG. 2, it can be seen that a slurry containing F-added MgO crystal powder having a maximum particle size of aggregates of 20 μm or less was obtained by crushing using a nanomizer at a pressure of 50 MPa or 100 MPa.

The specific surface areas of the comparative sample, the 50 MPa sample, and the 100 MPa sample are estimated to be 0.43, 5.79, and 6.98 m ² / g, respectively, assuming that the form factor is 6, It can be seen that an effective surface area increase of 10 times or more was realized. The specific surface area was estimated by calculation from the particle size distribution.
Moreover, when comparing the intensity of ultraviolet light emission of 200-300 nm with vacuum ultraviolet light having a wavelength of 147 nm for the comparative sample, 50 MPa sample, and 100 MPa sample, the intensity reduction due to the crushing treatment is suppressed to about 10-20% at the worst. It was done.

2-2. Next, the PDP having the structure shown in FIGS. 1A to 1C having the P particle release layer 15 was manufactured by the following method using the slurry prepared in the above step.

2-2-1. 1. Overview As shown in FIGS. 1A to 1C, a front-side substrate assembly 1 is manufactured by forming a display electrode 3, a dielectric layer 4, a protective layer 5, and a P particle emission layer 15 on a glass substrate 1a. . Further, the back-side substrate assembly 2 was fabricated by forming the address electrode 6, the dielectric layer 9, the partition wall 7, and the phosphor layer 8 on the glass substrate 2a. Next, the front side substrate structure 1 and the back side substrate structure 2 were overlapped and the peripheral edge portion was sealed with a sealing material to produce a panel having an airtight discharge space inside. Next, after exhausting the inside of the discharge space, a discharge gas was enclosed to complete the PDP.

2-2-2. Method for Forming P Particle Release Layer The P particle release layer 15 was formed in detail by the following method.
First, the slurry produced at the said process was spray-sprayed on the protective layer 5 using the spray gun for coating, and the P particle discharge | release layer 15 was formed by repeating the process dried by spraying dry air several times after that. The P particle release layer 15 was formed so that the weight of the F-added MgO crystal powder was 0.15 mg / cm ² .

2-2-3. Other Other conditions are as follows.

Front side substrate structure 1:
Display electrode 3a width: 270 μm
Metal electrode 3b width: 95 μm
Discharge gap width: 100 μm
Dielectric layer 4: formed by coating and baking low melting point glass paste, thickness: 30 μm
Protective layer 5: MgO layer by electron beam evaporation, thickness: 7500 mm

Back side substrate structure 2:
Address electrode 6 width: 70 μm
Dielectric layer 9: formed by coating and firing a low melting glass paste, thickness: 10 μm
Thickness of the phosphor layer 8 directly above the address electrode 6: 20 μm
Material of phosphor layer 8: Zn ₂ SiO ₄ : Mn (green phosphor)
Partition 7 height: 140 μm Top width: 50 μm
The pitch of the partition walls 7 (dimension A in FIG. 1A): 360 μm
Discharge gas: Ne96% -Xe4%, 500 Torr

2-3. Observation of Appearance of P Particle Emission Layer Optical micrographs of the surface on which the F-added MgO crystal powder of PDP produced in the above process was dispersed are shown in FIGS. 3A to 3C are photographs corresponding to the comparative sample, the 50 MPa sample, and the 100 MPa sample, respectively. According to FIGS. 3A to 3C, it can be seen that in the 50 MPa sample and the 100 MPa sample, the F-added MgO crystal powder is more uniformly dispersed than in the comparative sample.

  4A and 4B show scanning electron micrographs of the surface on which the F-added MgO crystal powder of PDP produced in the above process was dispersed. FIGS. 4A and 4B are photographs corresponding to the comparative sample and the 100 MPa sample, respectively. According to FIGS. 4 (a) and 4 (b), it can be seen that large aggregates exceeding 20 μm are present in the comparative sample, whereas aggregates exceeding 20 μm were not observed in the 100 MPa sample.

2-4. Discharge delay test and electron emission probability evaluation test Next, a discharge delay test was performed on each manufactured PDP. The discharge delay test was performed using the voltage waveform for measurement shown in FIG. In the reset discharge period, a reset discharge is caused between the sustain electrode 3X and the scan electrode 3Y to reset the charge state of the dielectric layer, thereby removing the influence of the previous discharge. In the preliminary discharge period, after a specific cell was selected, a discharge was caused between the sustain electrode 3X and the scan electrode 3Y to excite the P particle emitting material. Thereafter, after a pause period of 10 μs to 50 ms, a voltage was applied to the address electrode 6 during the address discharge period, and the time from when this voltage was applied until when the discharge was actually started was measured.

  The results of measuring the discharge delay are shown in FIGS. 6 and 7, the horizontal axis represents the discharge pause period from when the discharge is performed until the discharge delay is measured. In FIG. 6, the vertical axis plots the time when the cumulative discharge probability is 90% when the discharge is performed 1000 times as the discharge delay. FIG. 7 plots the reciprocal of the relaxation time (TL) of the exponential function component on the Laue plot on the vertical axis, which is an amount reflecting the electron emission probability.

  According to FIG. 6, it can be seen that the discharge delay was shorter in the 50 MPa sample and the 100 MPa sample than in the comparative sample. Further, according to FIG. 7, it can be seen that the electron emission probability increased about 2 to 4 times in the 50 MPa sample and the 100 MPa sample as compared with the comparative sample.

  These results show that when the P particle emission layer 15 is formed using F-added MgO crystal powder having a maximum aggregate particle size of 20 μm or less, the effect of shortening the discharge delay is increased and the electron emission probability is increased. It shows that it has become higher.

3. Reference experiment showing effect of improving discharge delay by halogen-added MgO crystal powder Hereinafter, a reference experiment showing effect of improving discharge delay by halogen-added MgO crystal powder is shown.
In the following experimental example, the discharge delay improvement effect by arranging the MgO crystal powder to which fluorine was added (hereinafter referred to as “F-added MgO crystal powder”) so as to be in contact with the discharge space was examined. Moreover, it compared with the case where the normal MgO crystal powder to which fluorine is not added is arranged so as to be in contact with the discharge space.

3-1. Preparation Method of Slurry Containing F-Added MgO Crystal Powder Five types of F-added MgO crystal powders (referred to as samples A to E) having different F addition amounts were prepared by the following method.

First, MgO crystal powder (product name: high-purity ultrafine powder magnesia (2000A) manufactured by Ube Materials Co., Ltd.) and MgF ₂ (manufactured by Furuuchi Chemical Co., Ltd., purity: 99.99%) are each mortar. And pulverized using a pestle and powdered.
Next, the aggregated and crushed MgO crystal powder and MgF ₂ were weighed so as to have the mixing amount shown in Table 1, and mixed with a tumbler mixer.
Next, the mixture was fired in the atmosphere at 1450 ° C. for 1 hour.
Next, the fired powder was agglomerated and pulverized to obtain powder, and F-added MgO crystal powders of Samples A to E were obtained.

  Next, F addition amounts of Samples A and C were measured by combustion ion chromatographic analysis. The results are shown in Table 1. Moreover, the estimated value of F addition amount of sample B, D, E estimated from the measured value of F addition amount of sample A and C was calculated | required according to the graph of FIG. In Table 1, the estimated value of the amount of F added is displayed in parentheses.

  Next, the F-added MgO crystal powder was mixed at a ratio of 2 g to 1 L of IPA (manufactured by Kanto Chemical Co., Ltd., for electronic industry), dispersed with an ultrasonic disperser, and agglomerated and disintegrated to prepare a slurry . In addition, a slurry was prepared by the same method using additive-free MgO crystal powder (manufacturer, trade name is the same as above).

3-2. PDP Manufacturing Method Next, a PDP was manufactured by the same method as “2-2. PDP manufacturing method”. However, the P particle release layer 15 was formed so that the weight of the F-added MgO crystal powder was 0.2 mg / cm ² .

3-3. Discharge delay test Next, a discharge delay test was performed by the method shown in "2-4. Discharge delay test and electron emission probability evaluation test".

  The obtained results are shown in Table 2, FIG. 9 and FIG. FIG. 9 is a graph showing the relationship between the rest period and the discharge delay for a PDP manufactured using Sample C and a PDP manufactured using an additive-free MgO crystal powder. FIG. 10 is a plot of Table 2.

  As can be seen from FIG. 9, the PDP manufactured using the sample C has a shorter discharge delay even in the longer rest period compared to the PDP manufactured using the additive-free MgO crystal powder. This means that the F-added MgO crystal powder, such as Sample C, lasts longer in the effect of suppressing the discharge delay than the additive-free MgO crystal powder. The reason why the effect of improving the discharge delay lasts for a long time in the F-added MgO crystal powder is not necessarily clear, but the added halogen element is replaced with oxygen in the MgO crystal powder, which becomes an electron trap and emits electrons. This is presumed to be due to improved characteristics.

  Further, as apparent from Table 2 and FIG. 10, it can be seen that the change in the discharge delay is small when the F addition amount is in the range of 24 to 440 ppm. This indicates that the addition amount of the F element does not significantly affect the discharge delay improvement effect. If the addition amount is in the range of about 1 to 10,000 ppm, the discharge delay improvement effect lasts for a long time. This is thought to suggest.

(A)-(c) shows the structure of PDP of one Embodiment of this invention, (a) is a front view, (b) and (c) are II in (a), respectively. It is sectional drawing and II-II sectional drawing. The particle size distribution figure about a comparative example sample, a 50MPa sample, and a 100MPa sample in the effect verification experiment of this invention is shown. (A)-(c) shows the scanning electron micrograph of the surface which sprinkled F addition MgO crystal powder of PDP. (A)-(c) respond | corresponds to a comparative example sample, a 50 MPa sample, and a 100 MPa sample, respectively. (A) And (b) shows the scanning electron micrograph of the surface which sprinkled F addition MgO crystal powder of PDP. (A) and (b) correspond to a comparative example sample and a 100 MPa sample, respectively. The waveform used for the measurement of the discharge delay in the effect verification experiment and reference experiment of this invention is shown. It is a graph which shows the relationship between an idle period and a discharge delay about a comparative example sample, a 50MPa sample, and a 100MPa sample in an effect verification experiment of the present invention. It is a graph which shows the relationship between a rest period and 1 / _TL about a comparative example sample, a 50MPa sample, and a 100MPa sample in an effect verification experiment of the present invention. It is a graph for calculating | requiring the estimated value of F addition amount of Example sample B, D, and E in a reference experiment. It is a graph which shows the relationship between an idle period and a discharge delay about PDP manufactured using the sample C concerning a reference experiment, and PDP manufactured using the additive-free MgO crystal. It is a graph which shows the relationship between the measured value or estimated value of F addition amount concerning a reference experiment, and discharge delay. It is a perspective view which shows the structure of the conventional PDP.

Explanation of symbols

1: Front side substrate structure 1a: Front side substrate 2: Back side substrate structure 2a: Back side substrate 3: Display electrode 3a: Transparent electrode 3b: Metal electrode 3X: Sustain electrode 3Y: Scan electrode 4: Dielectric layer 5: Protection Layer 6: Address electrode 7: Partition 8: Phosphor layer 9: Dielectric layer 15: P particle emission layer

Claims (9)

A pair of substrates opposed to each other through a discharge space, a plurality of display electrodes on one substrate, a dielectric layer covering the display electrodes, and a priming particle emitting layer on a surface of the dielectric layer in contact with the discharge space And further comprising a plurality of address electrodes intersecting the display electrodes,
The plasma display panel according to claim 1, wherein the priming particle emitting layer is made of a priming particle emitting powder having a maximum aggregate particle size of 20 μm or less. The plasma display panel according to claim 1, wherein the priming particle emitting powder has a maximum particle size of the aggregate of 10 µm or less. The plasma display panel according to claim 1, wherein a protective layer made of magnesium oxide is provided on the dielectric layer, and the priming particle emitting layer is provided on the protective layer. The plasma display panel according to claim 1, wherein the priming particle emitting powder is made of magnesium oxide crystal powder. The plasma display panel according to any one of claims 1 to 3, wherein the priming particle emission powder is made of magnesium oxide crystal powder to which 1 to 10,000 ppm of a halogen element is added. The plasma display panel according to claim 5, wherein the halogen element is fluorine. The plasma display panel according to claim 6, wherein the amount of fluorine added is 5 to 1000 ppm. The priming particle emitting layer according to claim 1 or 3 is formed by applying or dispersing a priming particle emitting powder on the surface of the dielectric layer or the surface of the protective layer,
The priming particle emitting powder is produced by crushing the aggregate in the raw material powder of the priming particle emitting powder so that the maximum particle size of the aggregate is 20 μm or less. A method for manufacturing a plasma display panel. The method for manufacturing a plasma display panel according to claim 8, wherein the crushing treatment is performed by a turbulent impact method.