JP2003045322A - Method for manufacturing plasma display panel - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To increase the brightness and reliability of a plasma display panel. SOLUTION: The average particle diameter is 0.1 μm to 1.5 μm on the surface of a display electrode 12 conventionally formed on a glass substrate.
Then, the glass powder is fired at a temperature within 20 ° C. from the glass softening point using a glass powder having a maximum particle size within three times the average particle size, and then a glass having a softening point of about 100 ° C. lower than the softening point of the glass is softened. Dielectric layer (dielectric glass lower layer (high softening point glass)) which is fired at a temperature 50 ° C. to 100 ° C. higher than the temperature
13a and dielectric glass upper layer (low softening point glass) 13b)
By forming, a plasma display panel with high brightness and clear image can be obtained.

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 improvement of a dielectric layer and a material of a dielectric glass layer of the plasma display panel.

[0002]

2. Description of the Related Art In recent years, expectations for high-definition and large-screen televisions such as high-definition television 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 limits to the screen size and viewing angle. On the other hand, the plasma display can realize a large screen, and a product of 40-inch class has already been developed.

FIG. 4 is a perspective view showing 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 sodium borosilicate glass by the float method.
There is a display electrode 50 composed of O and a silver electrode, on which a dielectric glass layer 5 having a two-layer structure formed by using glass powder having an average particle diameter of 2 μm to 15 μm which functions as a capacitor.
2, 53 and magnesium oxide (MgO) dielectric protective layer 5
4 covers. Reference numeral 55 denotes a back glass substrate (back plate). Address electrodes (ITO and silver electrodes) 56 and a dielectric glass layer 60 are provided on the back glass substrate 55, and a partition wall 58 and a phosphor layer 59 are provided thereon. The space between the barrier ribs 58 is a discharge space 59 for enclosing the discharge gas.

[0004]

The pixel level of a full-spec high-definition television, which is expected in recent years, is 1920 × 1125 pixels, and the dot pitch is 42 inch class, 0.15 mm × 0.48 mm, 1 cell. Area is 0.072 mm2.

When a high-definition television having the same size of 42 inches is manufactured, the area of one pixel is larger than that of the conventional NTSC.
(Number of pixels 640 x 480, dot pitch 0.43 mm
When compared with × 1.29 mm, the area of one cell is 0.55 mm 2), the fineness is 1/7 to 1/8. Therefore, the brightness of the panel becomes low.

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 electrodes 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 the dielectric layer. The first method is that the average particle size of the glass powder is 5 to 6 μm and the softening point of the glass is 550 to 600 ° C.
Glass (lead oxide-based glass or bismuth oxide-based glass) is used, and the vicinity of the softening point of the glass (550 ° C. to 600 ° C.) is used.
It is a method of forming a dielectric layer by firing at (° C.). The advantage of this method is that it is in an inactive state in which the glass does not flow so much because it is fired near the softening point. Therefore, the glass (viscosity is 10 7 poise) Ag, ITO, Cr-Cu
It hardly reacts with etc. Therefore, the resistance value of the electrode is not increased, the electrode component is not diffused and colored in the glass, and the dielectric layer can be formed by firing once.

However, the problem with this method is that the average particle size of the glass powder is 5 μm to 6 μm and the glass has poor fluidity because it is fired near the softening point of the glass and the surface is 4 μm.
The surface becomes a rough surface of ˜6 μm, visible light is scattered, and it becomes frosted glass, and the visible light transmittance of the dielectric glass layer decreases. As a result, the sharpness of the image is reduced, and bubbles and pinholes are generated in the dielectric, which lowers the breakdown voltage of the dielectric layer.

The second method is to use a low melting point lead glass powder (PbO of about 75%) having an average particle diameter of 5 μm to 6 μm and a softening point of about 450 to 500 ° C. from the softening point of 50 ° C. There is a method of firing at 550 to 600 ° C, which is about 100 ° C higher. The advantage of this method is that since the firing temperature of glass is sufficiently higher than the softening point, the fluidity of glass is good,
That is, a glass layer having a flat surface (surface roughness of about 2 μm) can be obtained, and a dielectric layer can be formed by firing once.

However, the problem with this method is that since glass is easily flowable and activated, Ag, ITO,
That is, the resistance value is increased by reacting with an electrode such as Cr-Cu-Cr or the dielectric layer is colored, and large bubbles are easily generated by the reaction with the electrode.

The third method is a method in which the first method and the second method are combined and has been realized and put into practical use (for example, Japanese Patent Laid-Open Nos. 7-105855 and 9-9).
No. 50769). That is, the average particle size of the glass on the electrode is 5 μm to 6 μm (the particle size distribution is 0.1 μm to 15 μm).
μm) and the glass having a softening point of 550 ° C. to 600 ° C. and being fired near the softening point, the dielectric layer also has an average particle size of 5 μm to 6 μm and a glass softening point of 4 μm.
50 from the softening point using glass powder of 50 ° C to 500 ° C
It is a method of forming a dielectric layer by firing at 550 ° C. to 600 ° C., which is higher by 100 ° C. to 100 ° C. 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 and flatten the glass surface to improve the transmittance of visible light and the withstand voltage.

However, even with this method, the average particle size on the electrode is
Since a single layer of a dielectric material fired with a glass powder of 5 μm to 6 μm exists as an electrode lower layer, bubbles still occur in the glass layer and at the interface with the electrode, so that the withstand voltage does not improve, and the bubbles and the glass are not formed. There is a problem in that the transmittance is reduced due to the scattering of light at the interface of and the image is blurred due to the scattering.

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

[0014]

In order to achieve the above object, in the plasma display panel of the present invention, the lower layer in which the dielectric glass layer on the first electrode is in contact with the first electrode, and the lower layer is not in contact with the first electrode. 20 ° C. from the softening point of the glass, using a glass powder having a two-layered glass layer composed of an upper layer and the lower layer having an average particle diameter of 0.1 μm to 1.5 μm.
A glass having a softening point lower than the softening point of the glass of the lower layer by an average of 100 ° C. and a temperature of 50 ° C. to 100 ° C. higher than the softening point of the glass. It is characterized by being a dielectric layer.

Further, the dielectric glass layer on the first electrode has a multi-layered glass layer consisting of 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
A glass powder having a diameter of μm is used for firing at a temperature within 20 ° C. from the softening point of the glass, and then the upper layer is formed by coating only the vicinity of the bus electrode on the lower layer, and the upper layer is the lower layer. From the softening point of the glass
It is characterized in that the dielectric layer is fired at a temperature 100 ° C. higher.

In the method for manufacturing a plasma display panel according to the present invention, the dielectric layer on the first electrode has a double-layered structure including a lower layer in contact with the first electrode and an upper layer not in contact with the first electrode. The lower layer has an average particle diameter of 0.1 μm to 1.5 μm and a glass softening point of 550 ° C.
A paste having a binder component composed of a solvent containing a glass powder component and a resin of 575 ° C., a plasticizer, and a dispersant is applied onto the first electrode by a die coating method or a screen printing method, and dried 560 ° C. to 590 ° C. The paste composed of a glass powder component having a softening point of 440 ° C. to 475 ° C. and a component containing a solvent, a plasticizer, and a dispersant including a resin component, which is fired at a temperature of ℃, is die-coated or screen-printed. Coated 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]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a front cover plate having a transparent electrode, a first electrode composed of a bus electrode on the transparent electrode, and a dielectric glass layer covering the first electrode,
In a plasma display panel in which a second electrode and a back plate on which a dielectric layer and a phosphor layer are arranged face each other, the glass powder for a lower dielectric layer in contact with the first electrode has an average particle size of 0. Glass powder with 1 μm to 1.5 μm and a softening point of glass of 550 ° C. to 575 ° C., such as lead oxide type, bismuth oxide type, zinc oxide type, phosphorus oxide type, and the like, with fine and uniform particle size distribution, and an organic binder After the paste is formed and dried, it is 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 the softening of the glass on the lower layer or only near the bus electrode. The glass whose point is 440 ° C to 475 ° C is 50 from this softening point.
By using a multi-layer structure in which the upper layer is formed by firing and removing the cells at a temperature as high as 100 ° C to 100 ° C, there are no bubbles or pinholes in the dielectric without reaction with the electrode, the surface is smooth and the transmittance is high. A dielectric glass layer can be formed.

Further, glass powder having such a small average particle diameter (glass powder having an average particle diameter of 0.1 μm to 1.5 μm and a uniform particle size distribution, that is, 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 and reduce the light scattering rate of the conventional two-layer structure (for example, Japanese Patent Laid-Open No. 9-50769). Even if the dielectric glass layer is 15 μm or less, the dielectric strength is good, and a panel with high brightness and efficiency can be obtained.

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

Moreover, glass powder having an average softening point lower than that of the lower layer by 100 ° C. is used on the lower layer, and the upper layer is fired at a temperature 50 ° C. to 100 ° C. higher than the softening point to sufficiently remove bubbles in the glass. 2 for 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 less likely to undergo dielectric breakdown can be formed. Therefore, it is possible to lower the discharge voltage and at the same time improve the dielectric strength of the dielectric.

Further, the brightness of the panel can be improved by thinning the dielectric layer. However, if the average particle size of the glass is made too small (average particle size 0.1 μm
The following) is not preferable because the component of the organic binder is 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 it is fired at a high temperature, the fluidity of the glass is improved, so that it is 3 μm or less.

[Introduction] First, the present invention will be outlined. First, in FIG. 4, the area of the display electrode 50 is S,
When 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 C.
Is represented by the following formula 1.

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

V = dQ / εS (Equation 2) (However, since the discharge space is in a plasma state during discharge, it becomes a conductor.) In the above Equations 1 and 2, when d is reduced, the electrostatic capacitance C as a capacitor is obtained. In addition, the discharge voltage V becomes large and the discharge voltage V at the time of addressing and displaying decreases.

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

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

Therefore, the inventors have made the average particle diameter of the glass powder used in the lower dielectric layer constituting the first electrode as small as 0.1 μm to 1.5 μm, preferably the maximum particle diameter. Is a glass powder with an average particle size of 3 times or less,
The glass is fired at a temperature within 20 ° C from the softening point of the glass to form a lower layer, and then the softening point is 100 ° C above the lower layer on average.
By firing a low glass at a temperature 50 ° C to 100 ° C higher than its softening point, a discharge voltage and a cell capacitance equivalent to those of a conventional NTSC are secured, and the dielectric strength is improved with a thinner dielectric layer. In addition, the transmittance of visible light was improved and the light scattering rate was reduced.

There are two cases, that is, 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. If it is less than 10 μm, the withstand voltage between the data electrode and the bus electrode becomes insufficient at the time of address discharge, and the withstand voltage cannot be maintained. In addition, during address discharge, a voltage is concentrated between the bus electrode and the data electrode,
Almost no voltage is applied between the transparent electrode and the data electrode. Therefore, if the 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, patterning of the upper layer is necessary. The voltage can be reduced. Therefore, the withstand voltage and the discharge 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 according to the present embodiment (hereinafter, referred to as
FIG. 3 is a cross-sectional view of an essential part of (“PDP”), in which the dielectric on the first electrode is a lamination of two lath layers. Similarly, FIG. 2 is 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 the sake of convenience, a PDP is actually constructed by arranging a large number of cells that emit red (R), green (G), and blue (B) colors. ing.
Further, although the first electrode and the second electrode are originally orthogonal to each other, they are illustrated as being parallel in the description.

As shown in FIGS. 1 and 2, this PDP has a discharge electrode (display electrode) 12 as a first electrode on a front glass substrate (front cover plate) 11, and the display electrode 12 is made of transparent ITO or SnO 2. A bus line on the electrode (12a) is made of Ag or Cr-Cu-Cr (12).
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), and within 20 ° C. from the softening point of the glass. A dielectric glass lower layer 13a fired at a temperature is arranged, and a glass having a softening point which is lower than the softening point of the lower dielectric glass by 100 ° C on average is 50 ° C to 100 ° C higher than the softening point of the glass. An address electrode 18 is provided on a front panel 10 including a dielectric glass upper layer 13b fired at a temperature and a rear glass substrate (back plate) 19.
And a dielectric glass layer 17 (glass composition is the same as that of the lower layer dielectric on the first electrode) formed by using glass powder containing titanium oxide (TiO2) that reflects the emission of the phosphor, and partition walls. A discharge space 30 formed between the front panel 10 and the rear panel 20 is adhered to the rear panel 20 on which the phosphor layers 16 of 15, R, G, and B colors are arranged.
It has a structure in which a discharge gas is enclosed, and is manufactured as shown below.

Preparation of Front Panel 10: Front Panel 10
Forms a discharge electrode (display electrode) 12 on the front glass substrate 11, and the average particle diameter is 0.1
In the glass of μm to 1.5 μm, the maximum particle size is preferably within 3 times the average particle size and the softening point is 600 ° C. or less, preferably 5
It is covered with a dielectric glass lower layer 13a prepared by firing glass powder at 50 ° C. to 575 ° C. at a temperature within 20 ° C. from this softening point, and then an average of 100 ° C. from the softening point of the lower dielectric glass. A low softening point is preferably 440 ° C to 4
Using glass powder at 75 ° C, 50 ° C to 10 ° C from the softening point
It is manufactured by covering with a dielectric glass upper layer 13b baked at a temperature higher by 0 ° C. and forming a protective layer 14 made of MgO (magnesium oxide) on this surface.

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

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

First, a glass for a lower dielectric layer (for example, PbO-B2O3-SiO2-M having a softening point of 550 ° C to 575 ° C) is used.
gO glass) with a wet jet mill having an average particle size of 0.1
The crushing conditions are set so that the maximum particle size of the crushed glass is within 3 times each average particle size. Next, 55 wt% to 70 wt% of this glass powder and 1 wt% to 2 wt% of ethyl cellulose or acrylic resin are added.
Binder component consisting of terpineol containing 0% by weight or butyl carbitol acetate 30% by weight to 4
5% by weight is thoroughly kneaded with a three-roll mill to prepare a paste for die coating or printing. In addition, if necessary, a plasticizer such as dioctyl phthalate, dibutyl phthalate, triphenyl phosphate, tributyl phosphate or the like, a dispersant, glycerol monooleate, sorbitan sesquioleate,
The printability may be improved by adding 0.1 to 0.4% by weight of homogenol (product name of Kao Corporation) alkyl allyl group phosphate.

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

(Regarding Preparation of Upper Layer of Dielectric Glass) Next, the upper layer of dielectric glass, for example, having a softening point of 440 ° C. to 4 °
PbO-B2O3-SiO2-CaO-based glass at 75 ° C was crushed with a ball mill to an average particle size of 2.5 µm, and then 55% by weight to 70% by weight of this glass powder and 1% by weight of ethyl cellulose or acrylic resin were added. 30% to 45% by weight of a binder component consisting of terpineol or butyl carbitol acetate containing 20% by weight,
Knead well with a three-roll to prepare printing paste or die coating paste.

If necessary, a plasticizer such as dioctyl phthalate, cibutyl phthalate, triphenyl phosphate,
Dispersing agents such as tributyl phosphate, glycerol monooleate, sorbitan sesquioleate, homogenol (KaO
The printability may be improved by adding 0.1 to 0.4% by weight of a phosphoric acid ester of an alkylallyl group, etc., manufactured by Corporation.

Next, using this paste, the dielectric lower layer 13
It is printed on a by an electrode screen printing method or a die coating method, dried, and then baked at 520 ° C to 590 ° C which is 50 ° C to 100 ° C higher than the softening point of the glass.

When the upper layer is formed only in the vicinity of the bus electrode 12b, patterning is performed by a screen printing method to print only a necessary portion, and after drying, the softening point of the glass is 50.
Baking at 520 ° C to 590 ° C, which is higher by 100 ° C to 100 ° C.

(Regarding 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 electrode 11 on which the discharge electrode 12 and the dielectric layer 13 are formed in FIG. 1) is provided in the D device body 45, and C
The inside of the VD device body 45 can be depressurized by an exhaust device 49. Further, a high frequency power source 48 for generating plasma is installed in the CVD device body 45.

The Ar gas cylinders 41a and 41b use a vaporizer (bubbler) for the argon [Ar] gas that is a carrier.
It is supplied to the CVD apparatus main body 45 via 42 and 43. The vaporizer 42 heats and stores a metal chelate that is a raw material (source) of MgO, and the Ar gas cylinder 41a.
The metal chelate can be evaporated and sent to the CVD apparatus main body 45 by blowing Ar gas from the inside.

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

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

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

The vaporizer 42 is used to form MgO from magnesium acetylacetone, and the vaporizer 43 is used to form the MgO protective layer 14 from magnesium dipivabroyl methane. Ar gas is sent from the Ar gas cylinder 41a or 41b while heating. At the same time, oxygen is supplied from the oxygen cylinder 44.

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

Plasma C is formed by using the CVD apparatus having the above structure.
The VD is also performed in the same manner as in the thermal CVD, but the heating temperature of the glass substrate 47 by the heater portion 46 is 2
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 source 48 is driven to apply a high frequency electric field of 13.56 MHz to generate plasma in the CVD device 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 method is used.
If the protective layer is formed by the D method, a dense protective layer can be formed.

The thinner the dielectric glass layer, the more remarkable the effect of improving the panel brightness and reducing the discharge voltage becomes. Therefore, it is desirable to set the thickness of the dielectric glass layer as thin as possible within the range where the withstand voltage does not decrease.

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 the present embodiment, the CVD
Method (thermal CVD method or plasma CVD method)
A protective layer made of magnesium oxide (MgO) having a (100) plane orientation 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 this embodiment, it is formed to a thickness of 1.0 μm by the plasma CVD method.

Fabrication of back panel 20: First, a resist recess is formed on the back glass substrate 19 by a photoresist method, and an address electrode 18 as a second electrode is formed in this recess in the same manner as the discharge electrode 12. Lift-off method),
Further, on the glass powder having the same kind of average particle size (0.1 μm to 3.5 μm) and particle size distribution as in the case of the front panel 10, titanium oxide TiO 2 having an average particle size of 0.1 μm to 0.5 μm is also added. The added white dielectric glass layer 17 is formed. The method for forming the white dielectric glass layer and the method for forming 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
The temperature was 540 ° C to 580 ° C.

Then, the partition walls 15 formed by the screen printing method or the plasma spraying method are fixed at a predetermined pitch. Then, one of red (R) phosphor, green (G) phosphor, and blue (B) phosphor is arranged in each space sandwiched by the partition walls 15 to form the phosphor layer 16. To do. Generally, PDP is used as the phosphor of each color R, G, B.
Although the phosphors used in the above can be used, the following phosphors are used here.

“Red phosphor”: Y2O3: Eu3 + “Green phosphor”: Zn2SiO4: Mn “Blue phosphor”: BaMgAl10O17: Eu2 + In the following, referring to FIG. Describe. First, in the server 71, 50% by weight of Y2O3: Eu3 + powder, which is a red phosphor having an average particle size of 2.0 μm, 1.0% by weight of ethyl cellulose, a solvent (α
-Terpineol) A phosphor mixture consisting of 49% by weight is mixed and stirred in a sand mill to obtain 15 centipoise (CP).
The coating liquid is added, and the red phosphor forming liquid is jetted from the nozzle portion 73 (nozzle diameter 60 μm) of the jetting device into the stripe-shaped partition wall by the pressure of the pump 72, and at the same time, the substrate is linearly moved, Form a red phosphor line. Similarly, red (BaMgAl10O17: Eu2
+) And green (Zn2SiO: Mn) lines are formed and then baked at 500 ° C. for 10 minutes to form the phosphor layer 16.

Production of PDP by pasting front panel 10 and back panel 20: Next, the front panel 10 and the back panel 20 produced as described above are pasted together using sealing glass, and are separated by the partition wall 15. The discharge space 30 is evacuated to a high vacuum (8 × 10 -7 Torr), and then a discharge gas having a predetermined composition is filled at a predetermined pressure to produce a PDP.

The PDP thus manufactured has a structure in which each electrode (discharge electrode and address electrode) is closely bonded to the lower layer of the dielectric glass, and the number of bubbles is extremely small.

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

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

The composition of the discharge gas to be sealed is the Ne--Xe system which has been used conventionally, but the content of Xe is 5% by volume or more, and the sealing pressure is 500 to 760 Torr.
By setting to, the emission brightness of the cell is improved.

As described above, since the PDP of this embodiment can reduce the discharge voltage, the load applied to each component of the panel during operation can be reduced. Moreover, since the dielectric strength is improved, for example, for repeated use over a long period,
Excellent initial performance such as high panel brightness and low discharge voltage can be maintained, and reliability is excellent.

In the present invention, the back panel 20 is used.
Since the dielectric glass layer 13 on the front panel 10 side has a greater effect on the luminance and the discharge voltage than the dielectric glass layer 17 on the side, if the dielectric glass layer on the front panel 10 side is made thinner, It is possible to obtain the effect of improving the brightness and the effect of reducing the discharge voltage.

[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. 1-6 and 9-14, 17-20
According to the above-described embodiment, the PDP has a glass softening point of 550 ° C. to 575 ° C. and an average particle size of 0.1 to 1.5 on the first electrode including the transparent electrode and the bus electrode thereon.
A dielectric glass layer fired at 560 ° C. to 590 ° C. using a glass powder having a maximum particle size of 3 μm or less of the average particle size in μm is used as a dielectric lower layer having a film thickness of 5 μm to 15 μm.

The 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 on the entire lower layer or near the bus electrodes. The PDP has a cell size of 42.
The height of the barrier ribs 15 is set to 0.15 mm and the interval (cell pitch) of the barrier ribs 24 is set to 0.15 mm according to the display for an inch high-definition television.
The distance d between the electrodes was set to 0.05 mm.

Then, Ne- containing 5% by volume of Xe was used.
The Xe-based mixed gas was sealed at a sealing pressure of 600 Torr.

Regarding the method of forming the MgO protective layer 14,
The protective layer was formed by the plasma CVD method. Further, in the plasma CVD method, the magnesium acetate acetone [M
g (C5H7O2) 2] or Magnesium Dipivaloyl Met
Hane [Mg (C11H19O2) 2] was used as the source.

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

The MgO protective layer formed in this manner is treated with X
When the crystal plane was examined by line analysis, Mg (C5H7O2) 2,
In all the samples, any source of Mg (C11H19O2) 2 was crystals oriented in the (100) plane.

Sample No. PDPs 1 to 8 are PbO-B2O3-SiO2-on the lower layer of the dielectric glass on the front panel.
Sample No. 9 to 16 using MgO-Al2O3 glass
ZnO-B2O3-SiO2-Al2O3-CaO-based dielectric glass is used for the samples Nos. 17 to 22 are Nb2O.
The 3-ZnO-B2O3-SiO2-CaO system was used respectively.

Regarding the dielectric glass upper layer of the front panel, Sample Nos. 1 to 8 were PbO-B2O3-SiO2-
Using CaO-based glass, sample Nos. 9-16 are P2O5-
Using ZnO-Al2O3-CaO glass, sample No1
7 to 22 are Bi2O3-ZnO-B2O3-SiO2-Ca.
O-based glass was used.

The dielectric glass layer of the rear panel has the same glass composition as that of the lower layer of the front panel and is made of titanium oxide (TiO 2).
A dielectric material to which is added is used.

As the discharge gas, a mixed gas of Ne-Xe (5% by volume) was used. The formation of the protective layer of MgO was all performed by the plasma CVD method. The source gas of MgO used in the plasma CVD method had almost no characteristic difference depending on the difference between magnesium accelacetone and magnesium dipivabroylmethane.

Sample No. 7,8,13,14,21,2
The PDPs 2, 29, 30, 35, and 36 are comparative examples, and the average particle size of the powder of the lower dielectric glass used when forming the dielectric glass layer was No. 7, and the maximum particle size was 3 μm. 6 μm, the average particle size of No 8 is 1.5 μm and the maximum particle size is 6 μm (4 times the average particle size), and the average particle size of No 15 is 3 μm
m has a maximum particle size of 6 μm, and No 16 has an average particle size of 1.5 μm.
m has a maximum particle size of 6.0 μm (4 times the average particle size), No2
No. 1 is the result of using an average particle size of 3 μm and maximum particle size of 9 μm, and No. 22 is an average particle size of 1.5 μm and maximum particle size of 6.0 μm (4 times the average particle size). ~
The settings are the same as those of the PDPs 6, 9, 14 and 17-20.

[Experiment] (Table 7) to (Table 9) Experiment 1; Sample No. manufactured as described above. 1-22
With respect to 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; Dielectric transmittance and light scattering rate (haze value) are values measured by a spectroscope.

Experiment 3; the withstand voltage test of the dielectric glass layer
Before sealing the panel, pull out the front panel and make the discharge electrode positive, print the silver paste on the dielectric glass layer, and after drying, make it negative, and apply a voltage to cause dielectric breakdown and withstand voltage. And The panel brightness is the condition that each prototype PDP is less likely to cause dielectric breakdown. Discharge sustaining voltage 1
It is a measured value when discharged at about 50 V and a frequency of about 30 KHz. The results are shown in Tables 7 to 9 above.

Experiment 4; Next, sample No. 1-22 PD
Twenty sheets of the same type as P were produced and subjected to accelerated life.

This accelerated life test was carried out under much severer conditions than normal use conditions, and the discharge sustaining voltage of 200
V was discharged at a frequency of 50 KHz for 4 hours continuously. Then, the state of destruction of the dielectric glass layer and the like in the panel (insulation breakdown voltage defect of the panel) was examined. The results are also shown in (Table 7) to (Table 9).

Consideration; Sample No. 1-6, 9-14, 17
According to the luminance measurement results of ˜20 (Table 7) to (Table 9), the panel brightness of the conventional PDP is about 400 cd / m 2 (“Flat panel display” 1997, p. 198 (FLA
T-PANEL DISPLAY 1997, PP19
8)), it shows excellent panel brightness.

From this, it is understood that the panel brightness can be improved by forming the entire dielectric glass layer thin and making the lower dielectric layer a glass layer having few bubbles. Also, since there is little light scattering, there is little blurring and distortion of the image.

Also, from the results of the observation of the state of bubbles, the dielectric strength test, and the accelerated life test of the panel, the average particle diameter of glass was set to 0.1 μm to 1.5 μm and the maximum particle diameter was 3 Sample No. in which the dielectric glass layer was formed by using glass within twice the number. In PDPs 1 to 6, 9 to 14, and 17 to 20, glass having an average particle diameter of 1.5 μm or more or glass having a maximum particle diameter of 3 times the average particle diameter of 1.5 μm or less is used. Sample N having a dielectric glass layer formed by
o. It is apparent that the dielectric strength and surface smoothness are superior to those of the PDPs of 7, 15, 16, 21, and 22.

From these results, the electrodes were coated with a dielectric lower layer prepared by using glass powder having an average glass particle size of 0.1 μm to 1.5 μm and having a maximum particle size within 3 times the average particle size. , Above that, the softening point of the glass is 50 ° C to 100
It can be seen that by forming the dielectric glass upper layer that is fired at a high temperature of ° C, it is possible to improve the brightness and the sharpness of the image more than before, and also to improve the dielectric strength voltage.

Sample No. 7,15,21 PDP
Glass having an average particle diameter of 3 μm or more, and N
o. The average particle size of the glass is 1.
5 μm, but maximum particle size is 6 μm (4 times the average particle size)
In the case of the dielectric lower layer prepared in the above step, the thickness of the dielectric glass layer on the Ag electrode is the same as the sample No. 1-6, 9-14, 17-
It can be seen that, even though it is the same as 20, the dielectric breakdown is likely to occur, the luminance is low, and the light scattering rate is high, even though it is the same as 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 having a dielectric glass layer covering the electrodes of the first electrode and a back plate having the second electrodes and the phosphor layer are opposed to each other. The body layer includes a lower layer in contact with the first electrode and an upper layer not in contact with the first electrode 2
A glass layer having a layered structure, wherein the lower layer has an average particle diameter of 0.1.
A glass having a softening point of, on average, 100 ° C. lower than the softening point of the glass of the lower layer by using glass powder having a particle size of μm to 1.5 μm and firing at a temperature within 20 ° C. from the softening point of the glass. Which is 5 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 with high discharge at a low discharge voltage and less blurring of the image, and high reliability in addressing and durability can be obtained. To be

When the back plate has 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 brightness can be improved.

[Brief description of 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 view of a CVD apparatus used when manufacturing the plasma display panel in the 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 application device 70 used when forming a phosphor layer 18.

[Explanation 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 Lower layer of dielectric glass (high softening point glass) 13b Dielectric glass upper layer (low softening point glass) 14 Protective film (MgO) 15 partitions 16 Phosphor 17 Dielectric glass layer 18 address electrodes 19 Rear glass substrate 20 back panel 30 discharge space 40 CVD equipment 41a Argon gas cylinder 41b Argon gas cylinder 42 Vaporizer 43 Vaporizer 44 oxygen gas cylinder 45 CVD equipment main body 46 Substrate heating heater 47 Front glass substrate on which a dielectric glass layer is formed 48 high frequency power supply 49 Exhaust device 70 Ink coating device 71 server 72 Pressurizing pump 73 Header (nozzle part) 74 ink flow

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Claims (11)

[Claims] 1. A method of manufacturing a plasma display panel having a front glass substrate having a transparent electrode, a first electrode composed of a bus electrode and a dielectric glass layer formed thereon, and a back glass substrate having a second electrode formed thereon. And has a softening point of 600 ° C. or lower and an average particle diameter of 0.1 μm to 1.5 μm.
m, a paste containing glass powder is applied on the first electrode formed on the front glass substrate by a die coating method or a screen printing method, and then baked to form a lower layer of the dielectric glass layer; A paste containing glass powder having a softening point lower than the softening point of the dielectric glass by 100 ° C. on average is applied onto the lower layer by a die coating method or a screen printing method,
And a step of forming an upper layer of the dielectric glass layer by firing at a temperature 50 to 100 ° C. higher than the softening point of the glass powder. 2. The method for manufacturing a plasma display panel according to claim 1, wherein an upper layer of the dielectric glass layer is formed only near the bus electrodes. 3. A glass powder having the same particle size and particle size distribution as the lower layer is used, and the average particle size is 0.1 μm to 0.5 μm.
3. The method of manufacturing a plasma display panel according to claim 1, further comprising a step of applying a paste containing titanium oxide TiO _{2 of} m on a second electrode formed on the rear glass substrate and baking the paste. 4. The glass powder used in the lower layer has an average particle size of 0.1 μm to 1.5 μm, and the maximum particle size has a particle size distribution within 3 times the average particle size. 3. A method for manufacturing a plasma display panel according to any one of 3 to 3. 5. The dielectric glass coated on the lower layer,
The method for manufacturing a plasma display panel according to claim 4, wherein the firing is performed at a temperature within 20 ° C. from the softening point. 6. The softening point of the lower dielectric glass is 500 to
The method of manufacturing a plasma display panel according to claim 5, wherein the temperature is 575 ° C. 7. The method of manufacturing a plasma display panel according to claim 3, wherein the dielectric glass coated on the second electrode is fired at 540 to 580 ° C. 8. The lower glass which is in contact with the first electrode has a softening point of 550 ° C. to 575 ° C., and its composition is 45% by weight to 65% by weight of lead oxide, 10% by weight to 30% by weight of boron oxide, and silicon oxide. 8. The plasma display panel according to claim 1, wherein the glass is composed of 10% by weight to 30% by weight, magnesium oxide 1% by weight to 10% by weight, and aluminum oxide 0% by weight to 3% by weight. Manufacturing method. 9. The lower glass in contact with the first electrode has a softening point of 540 ° C. to 570 ° C., and its composition is 44% by weight to 60% by weight of zinc oxide, 19% by weight to 30% by weight of boron oxide, and 1% of silicon oxide. Wt% to 10.5 wt%, aluminum oxide 1
8. The method for manufacturing a plasma display panel according to claim 1, wherein the glass is a zinc oxide-based glass composed of 10% by weight to 10% by weight and 4% to 10% by weight of calcium oxide. 10. The lower glass which is in contact with the first electrode has a softening point of 540 ° C. to 570 ° C., and its composition is 44% by weight to 60% by weight of zinc oxide, 19% by weight to 30% by weight of boron oxide,
10. The method for manufacturing a plasma display panel according to claim 8, wherein the zinc oxide glass is composed of 9 wt% to 19 wt% of niobium oxide and 0 wt% to 5 wt% of calcium oxide. 11. A lead oxide glass composed of lead oxide-boron oxide-silicon oxide-calcium oxide or a phosphorus oxide composed of phosphorus oxide-zinc oxide-aluminum oxide-calcium oxide, wherein the composition of the upper glass on the first electrode is. 10. The plasma display panel according to claim 8, wherein the plasma display panel is any one of a bismuth oxide-based glass composed of bismuth oxide-zinc oxide-boron oxide-silicon oxide-calcium oxide. Production method.