JP2002304947A - Plasma display panel - Google Patents

Abstract

(57) [Problem] To provide a dielectric glass layer and a MgO protective layer of a plasma display panel with high withstand voltage and high reliability. SOLUTION: PbO-B ₂ O ₃ -which has been conventionally used.
SiO _{2 system, PbO-B 2 O 3 -SiO} 2 -ZnO system, and _{PbO-B 2 O 3 -SiO 2} -Al 2 O 3 based dielectric glass layer, is moreover bubbles disappear lowering the viscosity of the glass By adding an easy metal oxide, the dielectric glass layer 13 having no defect can be formed. Also preferably, M
By forming the gO layer 14 by a CVD method, a layer without defects can be formed. Therefore, a highly reliable plasma display panel with a high yield 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.
In particular, the present invention relates to a dielectric glass layer and a MgO layer of a plasma display panel.

[0002]

2. Description of the Related Art FIG. 3 is a schematic sectional view of a conventional alternating current (AC) type plasma display panel. In FIG. 3, reference numeral 31 denotes a front cover plate (front glass substrate) made of a sodium borosilicate glass formed by a float method. On the front glass substrate 31, an indium-tin-based transparent electrode 32 and a bus electrode thereon are provided. A display electrode 34 composed of a silver electrode 33 is present, and a dielectric glass layer 35 acting as a capacitor and a magnesium oxide (MgO) dielectric protection layer 36 having a crystal orientation plane oriented to the (111) plane are formed thereon. I'm covering. Conventionally, the dielectric glass layer 35 mainly includes lead oxide (PbO), boron oxide (B ₂ O ₃ ), silicon oxide (SiO ₂ ), and zinc oxide (Z
Lead oxide-based glass having a relatively low melting point (melting point: 500 to 600 ° C.) made of nO) or aluminum oxide (Al ₂ O ₃ ) has been used (for example, JP-A-7-105855).

The above MgO dielectric layer 36 is mainly composed of M
It has been formed by a vacuum evaporation method using electron beam heating using gO as a raw material (see, for example, JP-A-5-342991).
No.).

Reference numeral 37 denotes a back glass substrate (back plate), on which an address electrode (silver electrode) 38 and a partition wall 39 are provided, and a phosphor layer 40 is filled with a discharge gas. Discharge space.

[0005]

In recent years, expectations for high-definition, 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 they are 40 and 40 in depth and weight.
Not suitable for large screens larger than inches. Liquid crystals, on the other hand, have excellent performances such as low power consumption and low driving voltage, but have limitations in screen size and viewing angle. On the other hand, the plasma display is capable of realizing a large screen, and a 40-inch class product has already been developed (for example, Functional Materials, February 1996, Vol. 1).
6, no. 27 pages).

However, the pixel level of the current 40 to 42 inch class plasma display is NTSC level (640 × 480 pixels, cell pitch 0.43 mm).
× 1.29 mm, the area of one cell is 0.55 mm ² ) (for example, Functional Materials, February 1996, Vol. 16, N
o. 27 pages).

The pixel level of a full-spec high-definition television which is expected in recent years has a pixel number of 1920 × 11.
25, and the cell pitch is also 42 inch class, 0.1
5mm x 0.48mm and the area of one cell is 0.072mm
² fineness. When a high-definition television is created with the same size of 42 inches, the area of one pixel is 1/7 to 1/8 smaller than that of NTSC. Therefore, not only the distance between the discharge electrodes (display electrodes) is shortened, but also the discharge space becomes small. Therefore, the panel is driven by the same discharge voltage as that of the conventional NTSC, and the dielectric glass is required to secure the brightness and reliability. It is necessary to increase the breakdown voltage, ensure high reliability, and increase the capacity of the layer and the MgO protective layer.

In particular, in order to increase the breakdown voltage and the reliability of the dielectric glass layer and the MgO protective layer, it is necessary to suppress bubbles and defects in these layers, and to increase the capacity (reduce the cell area). Therefore, in order to ensure the same capacitance as a capacitor, it is necessary to reduce the thickness of the dielectric glass (MgO layer).

When a dielectric glass layer or an MgO film is formed thinner than before using a conventional PbO-based dielectric glass or an MgO film formed by a vacuum deposition method, and applied to a plasma display panel for high definition, bubbles and defects in the film are generated. Therefore, there is a problem that a defective rate in a step of aging the panel is increased.

In addition, silver in the silver electrode on the front panel diffuses toward the glass substrate when the dielectric glass is fired, and is reduced to tin ions (Sn ions) in the glass to generate silver colloids, which turn yellow. There was a problem of discoloration,
In particular, when the electrode pitch is narrow like in HDTV,
A yellow filter is applied to the panel, which is a major issue in image quality.

Therefore, the present invention provides a method for producing a dielectric glass layer or MgO layer.
It is an object of the present invention to provide a plasma display panel with high film reliability and no problem in image quality.

[0012]

SUMMARY OF THE INVENTION The present invention has been conventionally used for solving the above problem, PbO-B ₂ O ₃ -SiO
_{2 system, PbO-B 2 O 3 -SiO} 2 -ZnO -based or PbO
_{-B 2 O 3 -SiO 2 -Al 2} O 3 based dielectric glass to reduce the glass viscosity, yet pinholes Ya be thin dielectric glass layer by the bubble extinction is added easy metal oxides Since a glass layer with few defects can be formed, high withstand voltage and high capacity can be achieved. Further, by changing the MgO layer from the conventional vacuum deposition method to the CVD method, the MgO layer also has a small number of defects and a dense film is formed. By taking the above measures, a highly reliable panel can be obtained even for a panel having a small cell pitch or cell area such as a high-definition television.

In addition, a transition metal oxide such as Cu ₂ O, CoO, or Cr is added to a PbO—B ₂ O ₃ —SiO ₂ glass.
_By adding ₂ O ₃ , Fe ₂ O ₃ , NiO, etc. to a small amount of glass, the viscosity of the glass is reduced and at the same time, the glass is colored blue or green, and the yellow color of the Ag colloid can be canceled on the image quality. Improvement can be measured.

[0014]

Embodiment 1 Hereinafter, a plasma display panel according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of an AC surface discharge type plasma display panel according to an embodiment of the present invention. In FIG. 1, a silver electrode 12 as a first electrode obtained by screen printing and firing is formed on a front glass substrate 11, and 80% by weight of lead oxide (PbO), 10 wt.
Wt% boron oxide (B ₂ O ₃ ), 8 wt% silicon oxide (S
A dielectric glass layer 13 made of iO ₂ ), 1% by weight of zinc oxide (ZnO), and 1% by weight of potassium oxide (K ₂ O) was fired after screen printing to form a film having a thickness of about 15 μm.

Next, a method of forming magnesium oxide (MgO) on the dielectric glass layer 13 by a CVD method (chemical vapor deposition) will be described with reference to FIG. The protective layer made of magnesium oxide (MgO) used for the protective film on the dielectric glass layer 13 is formed by CVD (chemical vapor deposition).
By using, the (100) -oriented dielectric protective layer 14 oriented to the (100) plane of magnesium oxide can be obtained.

FIG. 2 is a schematic view of a CVD apparatus (in particular, a thermal CVD method is used in this embodiment) used for forming a protective layer of a plasma display panel.

In FIG. 2, reference numeral 21 denotes an alkaline earth metal chelate or a cyclopentadienyl compound having a CV
Argon (Ar) gas cylinder for transporting into the D apparatus, 22 is a vaporizer (bubbler) for heating and evaporating a metal chelate as a raw material of an alkaline earth oxide (MgO), 23 is an oxidation of the alkaline earth Vaporizer (bubbler) for heating and evaporating a cyclopentadienyl compound as a raw material of a product (MgO), 24 is an oxygen cylinder as a reaction gas, 25 is a CVD apparatus main body, 26 is a heater for heating a substrate, and 27 is a heater for heating a substrate. A glass substrate on which a dielectric glass layer is formed, 2
Reference numeral 8 denotes a high-frequency power supply used when performing plasma CVD, and reference numeral 29 denotes an exhaust device.

First, an organic binder (a meter pinol containing 10% of ethyl cellulose) is contained on a silver electrode, which is prepared by screen printing and firing.
A lead-based dielectric glass layer comprising 80% by weight of PbO, 10% by weight of B ₂ O ₃ , 8% by weight of SiO ₂ , 1% by weight of ZnO and 1% by weight of K ₂ O is formed by a screen printing method. After 55
The glass substrate 27 obtained by baking at 0 ° C. for 10 minutes is subjected to CV
D is placed on the heater section 26 heated to 350 ° C. in the D apparatus 25, and then 1 liter of Ar gas per minute is supplied from the Ar cylinder 21 for 1 liter.
Magnesium dipivabroylmethane [Mg (C ₁₁ H ₁₉ ), an alkaline earth metal chelate, heated to 25 ° C.
O ₂₎ ^2] is entered vaporizer 22 a reaction gas simultaneously from cylinder 24 to flow for 1 minute on a glass substrate 27 is oxygen (O ₂₎ also flows over 20 seconds the glass substrate 27 at a rate per minute 2l a through by Thermal CVD was performed to form a protective layer of magnesium oxide (MgO) of 0.3 μm (film formation speed: 1.0 μm / min).

As a result of X-ray analysis of this MgO film,
This film was found to be oriented in the (100) plane. Next, a method of manufacturing a plasma display panel by laminating a front panel with a protective layer and a back panel will be described with reference to FIG.

In FIG. 1, a silver electrode (address electrode) 16 as a second electrode obtained by firing after screen printing, and a glass partition wall 1 having a height of 0.15 mm.
7 (interval between partition walls 0.15 mm) and a phosphor layer 18 [phosphor is red; (Y _X Gd ₁ -x) BO ₃ : E
u ³⁺ , green; Zn ₂ SiO ₄ : Mn, blue; BaMgAl
₁₀ O ₁₇ : Eu ²⁺ is separated by a partition wall, but only one color is shown in FIG. 1]. A back glass substrate 15 provided with Before filling the discharge gas, the discharge space 19 was 8 × 1
The chamber was evacuated to a vacuum of 0 ^-7 Torr, and helium (He) gas containing 10% xenon (Xe) gas was filled as a discharge gas in the discharge space at 500 Torr to obtain an AC surface discharge plasma display.

Next, 20 panels were prepared by the same manufacturing method, and a discharge sustaining voltage of 250 was used for aging the panels.
After discharging at V and a frequency of 50 KHz for 4 hours, the panel was examined for defects (defects due to breakdown of the dielectric during aging). As a result, 21 panels had defects in 3 panels. The results are shown in sample number 1 in the table below.

[0022]

[Table 1]

Embodiment 2 Next, a plasma display panel according to Embodiment 2 of the present invention will be described with reference to the drawings. In this embodiment,
Embodiment 2 is different from Embodiment 1 in that the panel is formed by a plasma CVD method instead of the thermal CVD method.

FIG. 1 is a schematic sectional view of an AC surface discharge type plasma display panel used for describing the present embodiment. A silver electrode 12 obtained by screen printing and firing is formed on a front glass substrate 11, and 70% by weight of lead oxide (PbO), 13% by weight of boron oxide (B ₂ O ₃ ), Wt% silicon oxide (Si
O _2), 5 wt% of zinc oxide (ZnO), a dielectric glass layer 13 of the lead-based of 2 wt% of lithium oxide (Li ₂ O) when incinerated after screen printing, formed to a thickness of about 20μm did.

Next, a method of forming MgO on the dielectric glass layer by plasma CVD (plasma chemical vapor deposition) will be described with reference to FIG.

FIG. 2 is a schematic view of a CVD apparatus used for forming a protective layer of a plasma display panel.
In FIG. 2, reference numeral 21 denotes an argon (Ar) gas cylinder for transporting an alkaline-earth metal chelate or a cyclopentadienyl compound into a CVD apparatus;
Vaporizer (bubbler) for heating and evaporating a metal chelate as a raw material of alkaline earth oxide (MgO), 23
Is a vaporizer (bubbler) for heating and evaporating a cyclopentadienyl compound as a raw material of an alkaline earth oxide (MgO); 24 is an oxygen cylinder as a reaction gas;
5 is a CVD apparatus main body, 26 is a heater for heating the substrate, 27 is a glass substrate on which a dielectric glass layer is formed,
Reference numeral 28 denotes a high frequency power supply used when performing plasma CVD, 2
9 is an exhaust device.

First, on a silver electrode obtained by firing after screen printing, 70% by weight of an organic binder (meter pinole containing 10% ethyl cellulose) was added.
PbO, 13% by weight B ₂ O ₃ , 10% by weight Si
A lead-based dielectric glass layer composed of O ₂ , 5% by weight of zinc oxide (ZnO), and 2% by weight of lithium oxide (Li ₂ O) is formed by screen printing and then fired at 550 ° C. for 10 minutes. The glass substrate 27 placed on the heater unit 26 of the CVD device 25 heated to 250 ° C.
1 to 1 liter / minute of Ar gas is heated onto a glass substrate 27 through a vaporizer 21 heated to 125 ° C. and containing Mg (C ₅ H ₅ ) ² which is a cyclopentadienyl compound of magnesium. At the same time, oxygen (O ₂ ), which is a reaction gas, is flown from the cylinder 24 at a rate of 2 liters per minute onto the glass substrate 27 for 1 minute, and then an exhaust device 29 is used in the reaction vessel to generate plasma. Then 1
The pressure was reduced to 0 Torr, and 13.56 M
A high frequency electric field of 300 Hz was applied at 300 watts (300 W) for 20 seconds, and plasma CVD was performed to form a 0.3 μm protective layer of magnesium oxide (MgO) (film formation rate: 0.9 μm / min).

As a result of X-ray analysis of this MgO film,
This film was found to be oriented in the (100) plane. Next, a method of manufacturing a plasma display panel by laminating a front panel with a protective layer and a back panel will be described with reference to FIG.

In FIG. 1, a silver electrode 16 obtained by screen printing followed by baking, a glass partition 17 having a height of 0.15 mm (distance between partitions 0.15 mm) and a phosphor layer 18 [fluorescent Body is red; (Y _X Gd
_1-X ) BO ₃ : Eu ³⁺ , green; Zn ₂ SiO ₄ : Mn, blue; BaMgAl ₁₄ O ₂₃ : Eu ²⁺ are separated by partition walls, respectively. FIG. 1 shows only one color. Is attached to the front panel using sealing glass, and the discharge space 19 is evacuated to a vacuum of 8 × 10 ⁻⁷ Torr before filling the discharge gas. Helium (He) gas containing 20% xenon (Xe) gas is filled in the discharge space as 600 Torr as a discharge gas,
An AC surface discharge type plasma display panel was used.

Next, 20 panels were prepared by the same manufacturing method, and a discharge sustaining voltage of 250 was used for aging the panels.
After discharging at V and a frequency of 50 KHz for 4 hours, the panel was examined for defects (defects due to breakdown of the dielectric during aging). As a result, defects were found in two of the 21 panels. This result was compared with the sample number 2 in (Table 1).
Shown in

Hereinafter, the composition of the dielectric glass, M
A front glass panel (front panel) was prepared by changing the film formation conditions of gO, etc., and a back panel (back panel) was laminated to prepare 21 plasma display panels, and maintained at a sustaining voltage of 250 V and a frequency of 50 KHz for 4 hours. The number of defective panels after aging is shown in (Table 1) and sample numbers 3 to 27 in the following table. However, sample number 24 ~
27 is a sample of a comparative example outside the present invention.

[0032]

[Table 2]

As is clear from the results of (Table 1) and (Table 2) described above, by controlling the composition of the dielectric glass layer, a dielectric glass layer having no defect can be formed. Preferably, the MgO layer is formed by a thermal CVD method or a plasma CVD method, whereby a defect-free MgO film can be formed. As a result, the reliability of the plasma display panel itself can be significantly improved.

Specifically, for the dielectric glass layer based on PbO—B ₂ O ₃ —SiO ₂ , 1% by weight to 1% by weight of metal oxide is used.
0% by weight (however, the metal oxide is potassium oxide (K ₂
O), lithium oxide (Li ₂ O), sodium oxide (N
a ₂ O), copper oxide (Cu ₂ O), silver oxide (Ag ₂ O), thallium oxide (Tl ₂ O _3), the addition of any kind) of vanadium oxide (V ₂ O _5), PbO -B ₂ O ₃ -S
iO ₂ -ZnO system or _{PbO-B 2 O 3 -SiO 2} -Al
1% by weight of metal oxide with respect to ₂ O ₃ -based dielectric glass
-10% by weight (however, metal oxides include potassium oxide (K ₂ O), lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), copper oxide (Cu ₂ O), and silver oxide (Ag
₂ O), thallium oxide (Tl ₂ O ₃ ), or vanadium oxide (V ₂ O ₅ ), the viscosity of the glass is reduced, and bubbles are easily eliminated. Even if the body glass layer is thin, a glass layer with few pinholes and defects can be formed, so that a high breakdown voltage and a high capacity can be achieved. Further, by changing the MgO layer from the conventional vacuum deposition method to the CVD method, the MgO layer also has a small number of defects and a dense film is formed. By taking the above means, a highly reliable panel can be obtained even in a panel having a small cell pitch or cell area, such as a high-definition television.

In addition, a transition metal oxide such as Cu ₂ O, CoO, or Cr is added to PbO—B ₂ O ₃ —SiO ₂ glass.
_By adding ₂ O ₃ , Fe ₂ O ₃ , NiO, etc. to a small amount of glass, the viscosity of the glass is reduced and at the same time, the glass is colored blue or green, and the yellow color of the Ag colloid can be canceled on the image quality. You can measure improvement.

In the dielectric glass composition, the range of PbO is limited to 60% by weight to 80% by weight. If it is 60% by weight or less, the melting point of the glass becomes high. This is because the dielectric glass must be fired at a temperature equal to or higher than the softening point of (float glass), which is not preferable because the substrate glass is deformed. Since the thermal expansion coefficient of the dielectric glass is 100 × 10 ⁻⁷ / ° C. or more, the substrate glass (with a thermal expansion coefficient of 83 to
(90 × 10 ⁻⁷ / ° C.), which is not preferable because a problem occurs.

The reason that the range of boron oxide (B ₂ O ₃ ) is limited to 10% by weight to 30% by weight is that if it is less than 10% by weight, the glass has poor fluidity and tends to crystallize. On the other hand, if the content is 30% by weight or more, the melting point becomes high, and the flow temperature of the glass (the temperature at which bubbles are removed) becomes near the softening point of the substrate glass, which is not preferable.

Further, the range of silicon oxide (SiO ₂ ) is limited to 5% by weight to 20% by weight.
It is not preferable because the withstand voltage of the dielectric glass is lowered.
If the content is not less than% by weight, the melting point of the glass becomes too high, which is not preferable.

Zinc oxide (ZnO) or aluminum oxide (Al ₂ O ₃ ) is an additive for stabilizing glass, and is suitably used in an amount of 1 to 10% by weight. Not demonstrated.

Further, metal oxides are additives for improving the flowability of glass and eliminating bubbles and defects.
0% by weight is suitable. If it is 1% or less, the effect is not exhibited, and if it is 10% or more, the pressure resistance is deteriorated and the coloring becomes intense, which is not preferable.

[0041]

As described above, the P according to the present invention is
_{bO-B 2 O 3 -SiO 2} -MO ( metal oxide) based, Pb
_{O-B 2 O 3 -SiO 2} -ZnO-MO ( metal oxide)
Systems, and _{PbO-B 2 O 3 -SiO 2} -Al 2 O 3 -MO
By using a (metal oxide) -based dielectric glass layer and a dielectric protective layer using an MgO layer formed by a CVD method, a plasma display panel with high reliability and a low defect rate can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a schematic diagram of a CVD apparatus used for manufacturing a plasma display panel according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional AC type plasma display panel.

[Description of Signs] 11 Front glass substrate (front cover plate) 12 Silver electrode (display electrode) 13 Dielectric glass layer 14 (100) oriented surface dielectric protection layer 15 Back glass substrate (back plate) 16 Address electrode 17 Partition wall 18 Phosphor 19 Discharge space 21 Argon gas cylinder 22 Vaporizer of metal chelate of alkaline earth (MgO) 23 Vaporizer of cyclopentadienyl compound of alkaline earth (MgO) 24 Oxygen gas cylinder 25 CVD device 26 Substrate heater 27 Dielectric Glass substrate on which glass layer is formed 28 High-frequency power supply for generating plasma 29 Exhaust device 31 Front glass substrate (front cover plate) 32 Transparent electrode 33 Silver electrode 34 Display electrode 35 Dielectric glass layer 36 (111) oriented plane dielectric Body protection layer (MgO layer) 37 Glass substrate (back plate) 38 address electrode (silver electrode) 39 partition wall 40 phosphor layer 41 discharge space

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroyuki Kawamura 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Terms (reference) 5C040 FA01 FA04 GB03 GB14 GD07 GE09 KA07 KA10

Claims (2)

[Claims] A first cover plate on which a first electrode and a dielectric glass layer are formed; and a back plate on which a second electrode and a phosphor layer are formed. The front cover plate and the back plate are arranged so that the two electrodes face each other with a predetermined distance therebetween, and a partition is provided between the front cover plate and the back plate. A plasma display panel comprising a dischargeable gas medium sealed in a space defined by the back plate and the partition walls, wherein the composition of the dielectric glass layer is 60% by weight to 80% by weight of lead oxide, and boron oxide. 10% to 30% by weight, 5% to 20% by weight of silicon oxide, 1% to 5% by weight of zinc oxide, 1% to 10% by weight of metal oxide However, metal oxides are potassium oxide, lithium oxide, sodium oxide, copper oxide, silver oxide,
One of thallium oxide and vanadium oxide)
A plasma display panel, characterized in that: 2. A semiconductor device comprising: a front cover plate on which a first electrode and a dielectric glass layer are formed; and a back plate on which a second electrode and a phosphor layer are formed. The front cover plate and the back plate are arranged so that the two electrodes face each other with a predetermined distance therebetween, and a partition is provided between the front cover plate and the back plate. A plasma display panel comprising a dischargeable gas medium sealed in a space formed by the back plate and the partition walls, wherein a composition of the dielectric glass layer is 60% by weight to 80% by weight of lead oxide, and boron oxide. 10 wt% to 30 wt%, silicon oxide 5 wt% to 20 wt%, aluminum oxide 1 wt% to 10 wt%, metal oxide 1 wt% to 10 Weight% (however, metal oxides are potassium oxide, lithium oxide, sodium oxide, copper oxide,
A plasma display panel comprising any one of silver oxide, thallium oxide, and vanadium oxide).