JP2002358894A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve luminance and reliability of a plasma display panel. SOLUTION: A plasma display panel of high luminance and clear image can be obtained by forming a dielectric layer of a double-layer structure (a dielectric glass lower layer (of high-softening-point glass) 13a and a dielectric glass upper layer (of low-softening-point glass) 13b) by baking glass powder with average particle size of 0.1 μm to 1.5 μm and maximum particle size within 3 times the average on the surface of a display electrode 12 hitherto formed on a glass substrate at temperature within 20 deg.C of its softening point, and then, baking glass with softening point lower than the above glass by about 100 deg.C at temperature higher than its softening point by 50 deg.C to 100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel used for a display device and the like, and more particularly to an improvement in a dielectric layer of a plasma display panel and an improvement in a material of a dielectric glass layer.

[0002]

2. Description of the Related Art In recent years, expectations for high-definition and large-screen televisions including high-definition televisions have been increasing. CRTs are superior to plasma displays and liquid crystals in terms of resolution and image quality, but are not suitable for large screens of 40 inches or more in terms of depth and weight. On the other hand, liquid crystal has excellent performance of low power consumption and low driving voltage,
There are limitations on screen size and viewing angle. On the other hand, the plasma display can realize a large screen, and a 40-inch class product has already been developed.

FIG. 4 is a perspective view of a main part of a conventional AC type plasma display panel. In FIG. 4, reference numeral 51 denotes a front glass substrate (front cover plate) made of a sodium borosilicate glass by a float method.
There is a display electrode 50 composed of O and silver electrodes, on which a dielectric glass layer 5 having a two-layer structure formed using glass powder having an average particle diameter of 2 μm to 15 μm serving as a capacitor.
2,53 and magnesium oxide (MgO) dielectric protective layer 5
4 is covering. Reference numeral 55 denotes a back glass substrate (back plate), on which an address electrode (ITO and silver electrode) 56 and a dielectric glass layer 60 are provided, on which a partition wall 58 and a phosphor layer 59 are provided. The space between the partition walls 58 is a discharge space 59 in which a discharge gas is sealed.

[0004]

The pixel level of a full-spec high-definition television which is expected in recent years is 1920 × 1125 pixels, the dot pitch is 42 inches, and 0.15 mm × 0.48 mm per cell. Has an area of 0.072 mm2.

When a high-definition television is manufactured in the same size of 42 inches, the conventional NTSC is used in an area of one pixel.
(640 x 480 pixels, dot pitch 0.43mm
× 1.29 mm, the area of one cell is 0.55 mm 2). Therefore, the brightness of the panel is reduced.

Further, not only the distance between the first discharge electrodes (display electrodes) is shortened, but also the discharge space is narrowed. In particular, the dielectric glass layer on the first electrode is used as a capacitor because the cell area is reduced. If you try to secure the same capacity of
It is necessary to make the film thickness thinner than before.

There are three conventional methods for forming a dielectric layer. In the first method, the average particle size of the glass powder is 5 to 6 μm and the softening point of the glass is 550 ° C. to 600 ° C.
(Lead oxide-based glass or bismuth oxide-based glass) using a glass having a softening point near the glass (550 ° C. to 600 ° C.).
C.) to form a dielectric layer. The feature of this method is that since the glass is in the inactive state where the glass does not flow much because of the calcination near the softening point, the electrodes Ag (ITO, Cr-Cu) having a glass viscosity of 10 7 poises are used.
Hardly reacts with etc. Therefore, the resistance value of the electrode does not increase, the electrode component does not diffuse into the glass to be colored, and the dielectric layer can be formed by one firing.

However, the problem with this method is that the glass powder has an average particle size of 5 μm to 6 μm and is fired near the softening point of the glass, so that the fluidity of the glass is poor and the surface is 4 μm.
The surface becomes a rough surface of about 6 μm, and the visible light is scattered to form a ground glass, and the transmittance of the dielectric glass layer to visible light is reduced. Therefore, the sharpness of the image is reduced, and bubbles and pinholes are generated in the dielectric, and the withstand voltage of the dielectric layer is reduced.

In the second method, low melting point lead glass powder (PbO is about 75%) having an average particle size of 5 μm to 6 μm and a softening point of about 450 to 500 ° C. There is a method of firing at 550 to 600 ° C., which is about 100 ° C. higher. The feature of this method is that the firing temperature of the glass is sufficiently higher than the softening point, so that the fluidity of the glass is good,
A glass layer having a flat surface (surface roughness of about 2 μm) can be obtained, and a dielectric layer can be formed by one firing.

However, the problem with this method is that Ag, ITO,
This means that a reaction occurs with an electrode such as Cr-Cu-Cr to increase the resistance value, the dielectric layer is colored, and that large bubbles are easily generated by the reaction with the electrode.

The third method is a method that combines the first method and the second method, and has been realized and put into practical use (for example, Japanese Patent Application Laid-Open Nos. 7-105855 and 9-105).
No. 50769). That is, the average particle size of the glass is 5 μm to 6 μm on the electrode (the particle size distribution is 0.1 μm to 15 μm).
After firing near the softening point using glass powder having a glass softening point of 550 ° C. to 600 ° C., the dielectric layer also has an average particle size of 5 μm to 6 μm and a glass softening point of 4 μm.
50 ° C. to 50 ° C. using a glass powder from the softening point to 50 ° C.
This is a method of firing at 550 ° C to 600 ° C, which is higher by 100 ° C to 100 ° C, to form a dielectric layer. The feature of this method is that by adopting such a two-layer structure, it is possible to suppress the reaction between the electrode and the glass, flatten the glass surface, and improve the transmittance of visible light and the withstand voltage.

However, even in this method, the average particle size on the electrode is
Since a dielectric fired with a glass powder of 5 μm to 6 μm is present as a lower layer of the electrode, bubbles are also generated in the glass layer and at the interface with the electrode. There is a problem that the transmittance is lowered due to the scattering of light at the interface, and the image is blurred due to the scattering.

It is an object of the present invention to provide a plasma display panel having high luminance and high reliability even in the case of a fine cell structure by overcoming such problems.

[0014]

In order to achieve the above object, a plasma display panel according to the present invention is characterized in that a dielectric glass layer on a first electrode is in contact with a lower layer in contact with the first electrode and is not in contact with the first electrode. A glass layer having a two-layer structure consisting of an upper layer, wherein the lower layer is made of a glass powder having an average particle size of 0.1 μm to 1.5 μm, and is heated to 20 ° C. from the softening point of the glass.
The upper layer is a glass having a softening point of 100 ° C. lower than the softening point of the glass of the lower layer, and is fired at a temperature of 50 ° C. to 100 ° C. higher than the softening point of the glass. It is a dielectric layer.

Further, the dielectric glass layer on the first electrode has a glass layer having a multilayer structure including a lower layer in contact with the transparent electrode and a bus electrode thereabove and an upper layer covering only the vicinity of the bus electrode. The lower layer has an average particle size of 0.1 μm to 1.5 μm.
μm glass powder, baked at a temperature within 20 ° C. from the softening point of the glass, and then the upper layer is coated only near the bus electrode on the lower layer, wherein the upper layer is the lower layer 50 ° C ~ from the softening point of glass
It is a dielectric layer fired at a temperature higher by 100 ° C.

Further, in the method of manufacturing a plasma display panel according to the present invention, the dielectric layer on the first electrode preferably has a multi-layered structure including a lower layer in contact with the first electrode and an upper layer not in contact with the first electrode. A lower layer having an average particle size of 0.1 μm to 1.5 μm and a glass softening point of 550 ° C.
A paste of 575 ° C. and a binder component composed of a solvent containing a glass powder component and a resin, a plasticizer, and a dispersant is applied on the first electrode by a die coating method or a screen printing method. Baked at 440C, and then a paste comprising a glass powder component having a glass softening point of 440C to 475C and a component comprising a solvent, a plasticizer, and a dispersant containing a resin component is die-coated or screen-printed. Is applied on the lower layer of the first electrode by the method
It is characterized by being obtained by firing at 0 ° C to 590 ° C.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front cover plate having a transparent electrode, a first electrode comprising a bus electrode provided thereon, and a dielectric glass layer covering the first electrode;
In a plasma display panel in which a second electrode is opposed to a back plate on which a dielectric layer and a phosphor layer are arranged, the lower dielectric glass powder in contact with the first electrode has an average particle size of 0.1. A glass powder of 1 μm to 1.5 μm with a softening point of 550 ° C. to 575 ° C., such as lead oxide or bis oxide, zinc oxide, phosphorus oxide, etc. Is applied, dried and fired at a temperature within 20 ° C. from the softening point of the glass to form a lower dielectric glass layer of the first electrode, and then softens the glass only on the lower layer or in the vicinity of the bus electrode. A glass having a temperature of 440 ° C. to 475 ° C.
By forming a multi-layer structure in which the upper layer is formed by baking and bleeding at a high temperature of 100 ° C to 100 ° C, there are no bubbles or pinholes in the dielectric without reaction with the electrodes, and the surface is smooth and high in transmittance. A dielectric glass layer can be formed.

Further, such a fine glass powder having an average particle size (a glass powder having an average particle size of 0.1 μm to 1.5 μm and a uniform particle size distribution, ie, a particle size distribution of 0.03 μm to
By using (4.5 μm) as the lower layer of the first electrode, it is possible to improve the visible light and the transmittance of the dielectric having the conventional two-layer structure (for example, JP-A-9-50769) and to reduce the light scattering rate. It is possible to obtain a panel with good dielectric strength and high luminance and efficiency even when the dielectric glass layer is 15 μm or less.

That is, the sinterability of the glass particles is enhanced by reducing the particle size of the lower layer glass powder and making the particle size distribution uniform, and the surface of the lower layer is smooth (surface roughness of 2 μm or less) and bubbles existing in the glass are reduced. A uniformly distributed state is obtained at 0.5 μm or less.

In addition, glass powder having a softening point lower than that of the lower layer by an average of 100 ° C. is used for the upper layer, and calcined at a temperature higher than the softening point by 50 ° C. to 100 ° C. to sufficiently remove bubbles in the glass. In order to create a cell, the dielectric layer as a whole
Even if a dielectric glass layer having a thickness of 0 μm or less is formed, a highly reliable dielectric layer that is not easily broken down can be formed. Therefore, it is possible to reduce the discharge voltage and at the same time to improve the dielectric strength of the dielectric.

Further, by reducing the thickness of the dielectric layer, the luminance of the panel can be improved. However, if the average particle size of the glass is too small (the average particle size is 0.1 μm
This is not preferable because the components of the organic binder are confined in the dielectric glass layer during firing.
The particle size of the upper glass is 50 ° C to 100 ° C from the softening point.
Since the firing is performed at a high temperature, the fluidity of the glass is improved.

[Introduction] First, the present invention will be outlined. First, in FIG. 4, the area of the display electrode 50 is S,
Assuming that the thickness of the dielectric glass layer on the display electrode is d, the dielectric constant of the dielectric glass layer is ε, and the charge on the dielectric glass layer is Q, the capacitance C between the display electrode 50 and the address electrode 56 is
Is represented by the following equation 1.

C = εS / d (Equation 1) Further, assuming that a voltage applied between the display electrode 52 and the address electrode 56 is V, and a charge amount accumulated on the dielectric glass layer on the display electrode 50 is Q. , V and Q have the relationship of the following equation 2.

V = dQ / εS (Equation 2) (However, the discharge space becomes a conductor because it is in a plasma state during the discharge.) In the above-described Equations 1 and 2, when d is reduced, the capacitance C as a capacitor becomes larger. And the discharge voltage V at the time of addressing or display is reduced.

That is, by reducing the thickness of the dielectric glass layer, a large amount of electric charge is accumulated even when the same voltage is applied, so that a higher capacity and a lower discharge voltage can be achieved.

However, if the thickness of the dielectric glass layer is simply reduced, the dielectric strength is reduced, and the dielectric layer is easily broken down when an address pulse or a display pulse is applied.

Therefore, the present inventors made the average particle size of the glass powder used in the lower dielectric layer constituting the first electrode as small as 0.1 μm to 1.5 μm, and preferably the maximum particle size thereof. Using a glass powder within 3 times the average particle size,
The glass is baked at a temperature within 20 ° C. from the softening point of the glass.
By firing a low glass at a temperature 50 ° C. to 100 ° C. higher than its softening point, the dielectric strength is improved by a thinner dielectric layer while maintaining a discharge voltage and cell capacitance equal to or lower than that of the conventional NTSC. Further, the transmittance of visible light was improved and the light scattering rate was reduced.

The upper layer is formed on the entire surface of the lower layer and the upper layer is formed only in the vicinity of the bus electrode. There are two cases where the upper layer is formed on the entire surface. If the thickness is 10 μm or less, the withstand voltage between the data electrode and the bus electrode during address discharge becomes insufficient, and the dielectric strength cannot be maintained. Also, at the time of address discharge, a voltage is almost intensively applied between the bus electrode and the data electrode,
A voltage is hardly applied between the transparent electrode and the data electrode. Therefore, if a dielectric is formed in a two-layer structure only in the vicinity of the bus electrode and the transparent electrode is left as a single layer, the upper layer needs to be patterned. The voltage can be reduced. Therefore, the withstand voltage and the sustaining voltage at the time of address discharge can be reduced at the same time, and the transparency of visible light can be improved.

Embodiment FIG. 1 shows an AC surface discharge type plasma display panel (hereinafter, referred to as an embodiment) according to the present embodiment.
FIG. 2 is a cross-sectional view of a main part of “PDP”, in which a dielectric on a first electrode is a lamination of two lath layers. FIG. 2 is also a cross-sectional view of the PDP according to the present embodiment, in which only the vicinity of the bus electrode has a two-layer laminated structure.
Although only three cells are shown in these figures for convenience, a PDP is formed by arranging a large number of cells emitting red (R), green (G), and blue (B) in actuality. ing.
In addition, the first electrode and the second electrode are illustrated to be orthogonal to each other, but to be parallel for explanation.

In this PDP, as shown in FIGS. 1 and 2, a front glass substrate (front cover plate) 11 has a discharge electrode (display electrode) 12 as a first electrode, and the display electrode 12 is made of a transparent material such as ITO or SnO2. Ag or Cr-Cu-Cr electrodes (12a) were used as bus lines on the electrodes (12a).
b) is provided. This display electrode 12
A glass powder having an average particle size of 0.1 μm to 1.5 μm (preferably, a glass powder having a maximum particle size within 3 times the average particle size) within 20 ° C. from the softening point of the glass. A dielectric glass lower layer 13a fired at a temperature is provided, and a glass having a softening point on average of 100 ° C. lower than the softening point of the lower dielectric glass is 50 ° C. to 100 ° C. higher than the softening point of the glass. A front panel 10 on which a dielectric glass upper layer 13b fired at a temperature is disposed, and an address electrode 18 on a rear glass substrate (back plate) 19
A dielectric glass layer 17 (glass composition is the same as that of the lower dielectric on the first electrode) made of a glass powder containing titanium oxide (TiO2) that reflects light emitted from the phosphor, A discharge space 30 formed between the front panel 10 and the rear panel 20 is bonded to a rear panel 20 on which phosphor layers 16 of R, G, and B are disposed.
It has a configuration in which a discharge gas is sealed therein, and is manufactured as described below.

Creation of Front Panel 10: Front Panel 10
In the first embodiment, a discharge electrode (display electrode) 12 is formed on a front glass substrate 11, and an average particle size of 0.1
glass having a maximum particle size of less than 3 times the average particle size and a softening point of 600 ° C. or less, preferably 5 μm to 1.5 μm.
Using a glass powder of 50 ° C. to 575 ° C., covering with a dielectric glass lower layer 13a formed by firing at a temperature within 20 ° C. from the softening point, and then 100 ° C. on average from the softening point of the lower dielectric glass A low softening point is desirable;
Using glass powder of 75 ° C, 50 ° C to 10 ° C from the softening point
It is manufactured by covering with a dielectric glass upper layer 13b fired at a temperature higher by 0 ° C. and forming a protective layer 14 made of MgO (magnesium oxide) on the surface.

(Regarding Preparation of Discharge Electrode) The discharge electrode (discharge sustaining electrode) 12 is formed on the front glass substrate 11 as follows. This will be described with reference to FIG.

First, on the front glass substrate 11, a thickness of 0.1
After forming 2 μm of ITO (a transparent conductor made of indium oxide and tin oxide) on the entire surface by sputtering, a 150 μm-wide striped electrode is formed by photolithography (distance between the electrodes is 0.05 mm) and then exposed to light. Silver paste is formed on the entire surface, and then the photolithographic method is used to form a silver paste having a width of 30 mm.
μm Ag bus line is formed on ITO, and then Ag
Is fired at 550 ° C. to form a discharge electrode 12 as a first electrode.

(Preparation of Dielectric Glass Lower Layer) The dielectric glass layer 13 is formed on the front glass substrate 1 as follows.
1 and the discharge electrode 12.

First, a lower dielectric glass (for example, PbO-B2O3-SiO2-M having a softening point of 550 ° C. to 575 ° C.)
gO-based glass) with an average particle size of 0.1 by a wet jet mill.
The crushing conditions are set such that the crushed glass is crushed to a size of from μm to 1.5 μm, and the maximum particle size of the crushed glass is within three times the average particle size. Next, 55% to 70% by weight of this glass powder and 1% to 2% by weight of ethyl cellulose or acrylic resin.
30% by weight to 4% by weight of a binder component comprising terpineol or butyl carbitol acetate containing 0% by weight.
5% by weight is well kneaded with a three-roll mill to prepare a die coating or printing paste. If necessary, a plasticizer such as dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, tributyl phosphate, a dispersant, glycerol monooleate, sorbitan sesquioleate,
The printability may be improved by adding 0.1 to 0.4% by weight of a homogenol (a product name of Kao Corporation) a phosphoric acid ester of an alkyl allyl group.

Next, a glass substrate 1 was prepared using this paste.
1, printed on the electrode 12 by a die coating method or a screen printing method, and after drying, 560 ° C. slightly higher than the softening point of the glass
Bake at 590 ° C.

(Regarding Preparation of Dielectric Glass Upper Layer) Next, an upper dielectric glass, for example, having a softening point of 440 ° C. to 4 ° C.
A PbO-B2O3-SiO2-CaO-based glass at 75 [deg.] C. is pulverized by a ball mill to an average particle size of 2.5 [mu] m, and then 55% to 70% by weight of this glass powder and 1% by weight of ethyl cellulose or acrylic resin. 30% to 45% by weight of a binder component consisting of terpineol or butyl carbitol acetate containing 20% by weight,
Knead well with three rolls to make a printing paste or a die coating paste.

If necessary, a plasticizer such as dioctyl phthalate, cybutyl phthalate, triphenyl phosphate,
Dispersants such as tributyl phosphate, glycerol monooleate, sorbitan sesquiolate, homogenol (KaO
Printability may be improved by adding 0.1 to 0.4% by weight of a phosphoric acid ester of an alkyl allyl group or the like (product name of Corporation).

Next, using this paste, the dielectric lower layer 13 is formed.
Print on electrode a by an electrode screen printing method or a die coating method, and after drying, fire at 520 ° C. to 590 ° C., which is 50 ° C. to 100 ° C. higher than the softening point of the glass.

When an upper layer is formed only in the vicinity of the bus electrode 12b, it is patterned by a screen printing method, and printing is performed only on a necessary portion.
Bake at 520 ° C to 590 ° C, which is higher by 100 ° C to 100 ° C.

(Formation of Protective Layer by CVD Method)
FIG. 3 is a schematic view of a CVD apparatus used when forming the protective layer 14.

This CVD apparatus is capable of performing both thermal CVD and plasma CVD.
A heater unit 46 for heating a glass substrate 47 (the front glass substrate 11 on which the discharge electrode 12 and the dielectric layer 13 are formed in FIG. 1) is provided in the D device main body 45.
The inside of the VD device main body 45 can be reduced in pressure by an exhaust device 49. A high-frequency power supply 48 for generating plasma is provided in the CVD apparatus main body 45.

The Ar gas cylinders 41a and 41b convert argon [Ar] gas as a carrier into a vaporizer (bubbler).
This is supplied to the CVD apparatus main body 45 via 42 and 43. The vaporizer 42 heats and stores the metal chelate serving as the raw material (source) of MgO, and stores it in the Ar gas cylinder 41a.
This metal chelate can be evaporated and blown into the main body 45 of the CVD apparatus by blowing Ar gas from.

Specific examples of the chelate include magnesium acetylacetone [Mg (C5H7O2) 2] and magnesium dipivabroylmethane [Mg (C11H19O2) 2].

The oxygen cylinder 44 supplies oxygen [O 2] as a reaction gas to the main body 45 of the CVD apparatus.

(1) When performing thermal CVD using this CVD apparatus, a glass substrate 47 is placed on the heater section 46 with the dielectric layer facing upward and heated to a predetermined temperature (250 ° C.). The pressure inside the reaction vessel is reduced by the exhaust device 49 (about several tens Torr).

When forming MgO from magnesium acetylacetone, the vaporizer 42 is used. When forming the MgO protective layer 14 using magnesium dipivabroylmethane, the vaporizer 43 is used to convert the chelate as a source to a predetermined vaporization temperature. While heating, Ar gas is fed from the Ar gas cylinder 41a or 41b. At the same time, oxygen is supplied from the oxygen cylinder 44.

As a result, the chelate compound fed into the CVD apparatus main body 45 reacts with oxygen to form an MgO protective film on the electrode of the glass substrate 47.

Using the above-structured CVD apparatus, the plasma C
The VD is performed in substantially the same manner as the thermal CVD, except that the heating temperature of the glass
The temperature is set to about 50 ° C., the pressure inside the reaction vessel is reduced to about 10 Torr by using the exhaust device 49, and the high-frequency power supply 48 is driven to apply a high-frequency electric field of 13.56 MHz, so that plasma is generated in the CVD apparatus main body 45. While generating, a metal oxide layer or a protective layer made of MgO is formed.

As described above, the thermal CVD method or the plasma CV
If a protective layer is formed by Method D, a dense protective layer can be formed.

Since the effect of improving the panel brightness and reducing the discharge voltage becomes remarkable as the thickness of the dielectric glass layer becomes thinner, it is desirable to set as thin as possible as long as the dielectric breakdown voltage is not reduced.

Therefore, in the present embodiment, the thickness of the dielectric glass layer 13 is set to the conventional thickness of 15 μm to 30 μm. That is, the lower layer is 5 μm to 15 μm, and the upper layer is 10 μm.
m to 15 μm.

Next, a protective layer 14 made of MgO is formed on the dielectric glass layer 13. In this embodiment, CVD
Method (thermal CVD method or plasma CVD method)
A protective layer made of magnesium oxide (MgO) having a (100) plane or a (110) plane orientation is formed. The protective layer 14 is formed by the CVD method in the same manner as the metal oxide. In the present embodiment, it is formed to a thickness of 1.0 μm by a plasma CVD method.

Preparation of back panel 20: First, a concave portion of a resist is formed on a rear glass substrate 19 by a photoresist method, and an address electrode 18 as a second electrode is formed in this concave portion in the same manner as the discharge electrode 12 ( Lift-off method),
Further, titanium oxide TiO2 having an average particle diameter of 0.1 μm to 0.5 μm is also added to glass powder having the same type of average particle diameter (0.1 μm to 3.5 μm) and particle size distribution as the front panel 10. The added white dielectric glass layer 17 is formed. The method for forming the white dielectric glass layer and the method for preparing the dielectric ink paste are the same as those for the dielectric glass of the front panel. The firing temperature of the white dielectric glass layer is
540 ° C to 580 ° C.

Then, the partition walls 15 formed by a screen printing method or a plasma spraying method are fixed at a predetermined pitch. Then, a phosphor layer 16 is formed by disposing one of a red (R) phosphor, a green (G) phosphor, and a blue (B) phosphor in each space sandwiched by the partition walls 15. I do. As a phosphor of each color R, G, B, PDP is generally used.
The following phosphors are used here.

“Red phosphor”: Y 2 O 3: Eu 3+ “Green phosphor”: Zn 2 SiO 4: Mn “Blue phosphor”: BaMgAl 10 O 17: Eu 2+ State. First, in the server 71, 50% by weight of a Y2O3: Eu3 + powder as a red phosphor having an average particle size of 2.0 .mu.m, 1.0% by weight of ethyl cellulose, and a solvent (.alpha.)
-Terpineol) was mixed and stirred in a sand mill with a phosphor mixture consisting of 49% by weight and 15 centipoise (CP).
The liquid for forming a red phosphor is ejected from the nozzle portion 73 (nozzle diameter 60 μm) of the ejecting device into the stripe-shaped partition wall by the pressure of the pump 72 at the same time as the pressure of the pump 72, and the substrate is moved linearly. A red phosphor line is formed. Similarly, red (BaMgAl10O17: Eu2)
+), Green (Zn2SiO: Mn) lines are formed and then baked at 500 ° C. for 10 minutes to form a phosphor layer 16.

Production of PDP by Laminating Front Panel 10 and Rear Panel 20: Next, the front panel 10 and the rear panel 20 produced as described above are laminated by using sealing glass, and separated by partition walls 15. After the interior of the discharge space 30 is evacuated to a high vacuum (8.times.10@-7 Torr), a discharge gas having a predetermined composition is sealed at a predetermined pressure to produce a PDP.

The PDP manufactured in this manner has a structure in which each electrode (discharge electrode and address electrode) is densely bonded to the lower layer of the dielectric glass, and has very few bubbles.

Further, since the upper layer of the dielectric glass is fired at a temperature higher by 50 ° C. to 100 ° C. than the softening point of the glass, the air bubbles completely escape from the glass. Therefore, if the thickness of the dielectric is the same, the transmittance of the lower layer and the upper layer two-layer structure is higher.

In this embodiment, the cell size of the PDP is set to 0.2 mm or less and the distance d between the discharge electrodes 12 is set to 0.1 mm or less so that the PDP is suitable for a 40-inch high-definition television. .

The composition of the discharge gas to be filled is a conventionally used Ne—Xe system, but the content of Xe is 5% by volume or more and the filling pressure is 500 to 760 Torr.
By setting to, the light emission luminance of the cell is improved.

As described above, the PDP of the present embodiment can reduce the discharge voltage, so that the load applied to each component of the panel during operation is reduced. In addition, since the withstand voltage has been improved, for example, for long-term repeated use,
Excellent initial performance such as high panel luminance and low discharge voltage can be maintained, and the reliability is excellent.

In the present invention, the rear panel 20
Since the dielectric glass layer 13 on the front panel 10 has a greater effect on the brightness and the discharge voltage than the dielectric glass layer 17 on the side, if the dielectric glass layer on the front panel 10 is made thinner, The effect of improving brightness and the effect of reducing discharge voltage can be obtained.

[0064]

[Examples] [Examples 1 to 6, 9 to 14 and 17 to 2
0, Comparative Examples 7, 8, 15, 16, 21, 22]

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

[Table 4]

[0069]

[Table 5]

[0070]

[Table 6]

[0071]

[Table 7]

[0072]

[Table 8]

[0073]

[Table 9]

(Table 1) to (Table 6), (Table 7) to (Table 9)
Sample No. shown in FIG. 1-6 and 9-14,17-20
The PDP according to the above embodiment has a glass having a softening point of 550 ° C. to 575 ° C. and an average particle size of 0.1 to 1.5 on a first electrode comprising a transparent electrode and a bus electrode thereon.
A dielectric glass layer fired at 560 ° C. to 590 ° C. using glass powder having a maximum particle diameter of 3 μm or less and having a maximum particle diameter of 3 μm is covered with a dielectric lower layer having a thickness of 5 μm to 15 μm.

A dielectric (upper layer) fired at 520 ° C. to 590 ° C. using glass powder having a softening point of 440 ° C. to 475 ° C. has a thickness of 5 μm to 15 μm over the entire lower layer or over the vicinity of the bus electrode. A composite dielectric is formed by stacking as described above, and the cell size of the PDP is 42
The height of the partition wall 15 is set to 0.15 mm, the interval between the partition walls 24 (cell pitch) is set to 0.15 mm, and the discharge electrode 12 is adjusted to fit an inch display for a high-definition television.
Was set to 0.05 mm between electrodes.

Then, when the content of Xe is 5% by volume of Ne-
An Xe-based mixed gas was sealed at a sealing pressure of 600 Torr.

The method for forming the MgO protective layer 14 is as follows.
The protective layer was formed by a plasma CVD method. In the plasma CVD method, Magnesium Acetylacetone [M
g (C5H7O2) 2] or Magnesium Dipivaloyl Met
hane [Mg (C11H19O2) 2] was used as a source.

As other conditions, in the plasma CVD method, the vaporizer temperature is 125 ° C., the heating temperature of the glass substrate 47 is 250 ° C., the Ar gas is 1 L / min, and the oxygen is 2 L / min for 1 minute on the glass substrate 47. Then, the pressure was reduced to 10 Torr, and a high frequency electric field of 300 W was applied from the high frequency power source 48 at 13.56 MHz for 20 seconds to form an MgO protective layer having a thickness of 1.0 μm (film formation speed: 1.0 μm / min).

The MgO protective layer thus formed is
When the crystal plane was examined by X-ray analysis, Mg (C5H7O2) 2,
All the samples of Mg (C11H19O2) 2 had crystals oriented in the (100) plane in all samples.

Sample No. The PDPs Nos. 1 to 8 are composed of PbO-B2O3-SiO2-
Using MgO-Al2O3 glass, samples Nos. 9 to 16
Used ZnO-B2O3-SiO2-Al2O3-CaO-based dielectric glass, and samples Nos. 17 to 22 used Nb2O
A 3-ZnO-B2O3-SiO2-CaO system was used.

Regarding the dielectric glass upper layer of the front panel, samples No. 1 to 8 were PbO—B 2 O 3 —SiO 2 —
Samples Nos. 9 to 16 were made of P2O5-
Sample No.1 using ZnO-Al2O3-CaO-based glass
7 to 22 are Bi2O3-ZnO-B2O3-SiO2-Ca
O-based glass was used.

The dielectric glass layer of the rear panel is made of titanium oxide (TiO 2) with the same glass composition as the lower layer of the front panel.
Was used.

As the discharge gas, a mixed gas of Ne—Xe (5% by volume) was used. The formation of the MgO protective layer was all performed by the plasma CVD method. The raw material gas of MgO used in the plasma CVD method hardly differed in characteristics depending on the difference between magnesium acecelacetone and magnesium dipivabroylmethane.

Sample No. 7,8,13,14,21,2
The PDPs 2, 29, 30, 35, and 36 are comparative examples, in which the average particle diameter of the powder of the lower dielectric glass used when forming the dielectric glass layer is 3 μm and the maximum particle diameter of No. 7 is 3 μm. No. 8 has an average particle size of 1.5 μm and a maximum particle size of 6 μm (four times the average particle size), and No. 15 has an average particle size of 3 μm.
m, the maximum particle size is 6 μm, and No16 has an average particle size of 1.5 μm.
m, the maximum particle size is 6.0 μm (four times the average particle size), No2
No. 1 is a result using an average particle diameter of 3 μm, a maximum particle diameter is 9 μm, and No. 22 is a result using an average particle diameter of 1.5 μm and a maximum particle diameter is 6.0 μm (four times the average particle diameter). ~
The settings are the same as those of the PDPs 6, 9, 14 and 17 to 20.

[Experiment] (Table 7) to (Table 9) Experiment 1; 1-22
Regarding the PDP, the size of the bubbles of the dielectric glass on the first electrode was observed by an electron microscope, and the average value was obtained.

Experiment 2: The transmittance and the light scattering rate (haze value) of the dielectric were measured with a spectrometer.

Experiment 3: The withstand voltage test of the dielectric glass layer
Before sealing the panel, pull out the front panel, make the discharge electrode positive, print the silver paste on the dielectric glass layer, make it negative after drying, apply the voltage, and withstand the voltage that causes dielectric breakdown And The panel luminance is a discharge sustaining voltage of 1 which is a condition that dielectric breakdown is difficult in each prototype PDP.
This is a measured value when discharging at about 50 V and a frequency of about 30 KHz. The results are also shown in Tables 7 to 9 above.

Experiment 4: Sample No. 1 to 22 PD
Twenty sheets of the same material as P were produced, and these were subjected to an accelerated life.

The accelerated life test was performed under severer conditions than normal use conditions.
V. The battery was discharged continuously at a frequency of 50 KHz for 4 hours. Thereafter, the state of breakdown of the dielectric glass layer and the like in the panel (insulation withstand voltage defect of the panel) was examined. The results are also shown in Tables 7 to 9.

Consideration: Sample No. 1-6, 9-14, 17
According to the measurement results of the luminances of Tables 1 to 20 (Tables 7 to 9), the panel luminance of the conventional PDP is about 400 cd / m 2 (“Flat Panel Display”, p. 198, 1997 (FLA)).
T-PANEL DISPLAY1997, PP19
8)), the panel brightness is excellent.

From this, it can be seen that the panel brightness can be improved by forming the entire dielectric glass layer thin and using the lower dielectric layer as a glass layer with few bubbles. In addition, the image is less liable to be blurred and distorted due to less scattering of light.

From the results of the observation of the state of bubbles, the dielectric withstand voltage test, and the accelerated life test of the panel, the average particle size of the glass was set to 0.1 μm to 1.5 μm, and the maximum particle size was 3 μm. Sample No. in which a dielectric glass layer was formed using a glass having a size of up to twice that of the sample No. In PDPs 1 to 6, 9 to 14, and 17 to 20, glass having an average particle size of glass of 1.5 μm or more, or glass having a maximum particle size that is three times or more than 1.5 μm is used. N on which a dielectric glass layer was formed
o. It is apparent that the PDPs of 7, 15, 16, 21, and 22 are superior in the withstand voltage and the surface smoothness.

From these results, it was found that the electrode was coated with a dielectric lower layer made of glass powder having an average particle size of glass of 0.1 μm to 1.5 μm and a maximum particle size of not more than three times the average particle size. And 50 ° C. to 100 ° C. above the softening point of the glass.
It can be seen that by forming the dielectric glass upper layer fired at a high temperature of ° C., it is possible to improve the luminance and the sharpness of the image as compared with the conventional case, and also to improve the withstand voltage.

The sample No. 7,15,21 PDP
The glass having an average particle diameter of 3 μm or more, and N
o. The average particle size of the glass in the PDPs of 8, 16 and 22 was 1.
5 μm, but the maximum particle size is 6 μm (four times the average particle size)
In the case of the dielectric lower layer formed by the sample No. 2, the thickness of the dielectric glass layer on the Ag electrode is equal to that of the sample No. 1-6, 9-14, 17-
It can be seen that the dielectric breakdown easily occurs, the luminance is low, and the light scattering rate is high even though it is the same as that of No. 20.

[0095]

As described above, according to the plasma display panel of the present invention, the first electrode and the first electrode
In a plasma display panel in which a front cover plate provided with a dielectric glass layer covering the electrodes and a back plate provided with a second electrode and a phosphor layer are opposed to each other, the dielectric on the first electrodes is A body layer including a lower layer in contact with the first electrode and an upper layer not in contact with the first electrode;
A glass layer having a layer structure, wherein the lower layer has an average particle size of 0.1.
A glass having a softening point of 100 ° C. lower than the softening point of the glass of the lower layer, wherein the glass is fired at a temperature within 20 ° C. from the softening point of the glass using a glass powder having a size of μm to 1.5 μm. From the softening point of this glass
By providing a dielectric glass layer by firing at a high temperature of 0 ° C. to 100 ° C., a plasma display panel having high luminance at a low discharge voltage, little image blur, and high reliability in addressing and durability can be obtained. Can be

When the back plate is provided with a second dielectric glass layer covering the second electrode, the same glass powder as the lower layer of the first electrode is formed on the second electrode. By adding TiO2 to the dielectric glass using, the visible light emitted by the vacuum ultraviolet light is efficiently reflected, and the reliability and the luminance can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a plasma display panel according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the plasma display panel according to the embodiment of the present invention.

FIG. 3 is a schematic diagram of a CVD apparatus used for manufacturing a plasma display panel according to an embodiment of the present invention.

FIG. 4 is a perspective view of a main part of a conventional AC type plasma display panel.

FIG. 5 is a schematic configuration diagram of an ink coating device 70 used when forming a phosphor layer 18;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Front panel 11 Front glass substrate 12 Discharge electrode (display electrode) 12a Transparent electrode (ITO, SnO2) 12b Bus electrode (Ag, Cr / Cu / Cr) 13 Dielectric glass layer 13a Dielectric glass lower layer (high softening point glass) 13b Upper layer of dielectric glass (low softening point glass) 14 Protective film (MgO) 15 Partition wall 16 Phosphor 17 Dielectric glass layer 18 Address electrode 19 Rear glass substrate 20 Rear panel 30 Discharge space 40 CVD apparatus 41a Argon gas cylinder 41b Argon gas cylinder 42 Vaporizer 43 Vaporizer 44 Oxygen gas cylinder 45 CVD apparatus main body 46 Substrate heater 47 Front glass substrate on which dielectric glass layer is formed 48 High frequency power supply 49 Exhaust device 70 Ink coating device 71 Server 72 Pressure pump 73 Header (nozzle part) 74 Ink flow

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C040 FA01 FA04 GB03 GB14 GD02 GD07 JA02 JA12 JA22 KA08 KB19 MA02 MA05 MA17

Claims (1)

[Claims] 1. A plasma display panel having a front glass substrate on which a first electrode including a transparent electrode and a bus electrode and a dielectric glass layer are formed, and a rear glass substrate on which a second electrode is formed. The dielectric glass layer has a laminated structure of a lower layer formed on the first electrode by firing a high softening point glass and an upper layer formed near the bus electrode by firing a low softening point glass. Wherein the thickness of the dielectric glass layer near the bus electrode is larger than that between the transparent electrodes.