JPH11339665A - Ac plasma display panel, substrate for it and protective film material for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a secondary electron discharging rate of a protective film on an AC(alternate current) PDP(plasma display panel), and to suppress and eliminate flicker and failed discharge lighting. SOLUTION: In this substrate for an AC PDP, an X-electrode 10 and a Y- electrode in parallel each other are extendedly formed on the surface of a glass substrate 1, a dielectric layer 2 to entirely cover the surface of these electrodes and the glass substrate 1 is formed, and a protective film 3 to entirely cover the surface of the dielectric layer 2 is formed. The protective film 3 is formed by using a pellet formed by baking it for 30 minutes at 1400 deg.C in the atmosphere as a vapor deposition source in an electron beam vapor deposition method after powder of basic magnesium carbonate penta-hydrate and powder of iron oxide are mixed at a designated rate and pressurized for molding in a die. The protective film 3 is heated at 350 deg.C-500 deg.C in a vacuum or a reductive atmosphere after it is formed. The protective film 3 comprises solution of magnesium oxide and iron oxide, and concentration of the iron oxide is 0.1 mol.% to 20 mol.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC type plasma display panel (hereinafter, referred to as "PDP"), and more particularly, to improving the secondary electron emission effect of a protective film of an AC type PDP and stabilizing discharge. Technology to become

[0002]

2. Description of the Related Art Due to its electrode structure, a PDP, which is a display utilizing a discharge light emission phenomenon, has a direct current type (DC type) in which a metal electrode is exposed in a discharge space and a metal electrode covered with a dielectric. It is roughly divided into AC type (AC type). Particularly, in the AC type PDP, a magnesium oxide (MgO) film is formed on the dielectric as a protective film of the dielectric.

The MgO film (protective film) functions as a protective film for preventing (a) the dielectric layer and the electrodes from being directly exposed to plasma and being damaged by ion bombardment. (B) a function of emitting secondary electrons for gas discharge when a discharge voltage is applied between predetermined electrodes (secondary electron emission effect), and (c) an MgO film by accumulating wall charges. Has a function of emitting electrons at a lower voltage than in the case where it does not have, that is, a function of reducing a discharge voltage.

As a method for forming the MgO protective film, an electron beam evaporation method is generally widely used.
(I) The reason that such a film forming method among MgO film forming methods can form a thin film having good crystallinity (crystal orientation is easily aligned) at the fastest speed, and (ii) forming by such a film forming method This is because the MgO film to be used is excellent in various performances (discussed above (a) to (c)) for the discharge in the AC type PDP.

[0005]

SUMMARY OF THE INVENTION However, PDP
When a small amount of impurity gas, for example, moisture or carbon dioxide gas is contained in the discharge gas, the discharge start delay caused by this causes problems such as flickering of the discharge and non-lighting when the discharge voltage is applied.

In order to solve such a problem, a PDP
Of course, the above problem can be solved by increasing the secondary electron emission rate of the protective film as well as removing the above-mentioned impurity gas as much as possible.

On the other hand, if the margin of the applied voltage is large,
Since a voltage large enough to cause a discharge can be stably applied, a stable discharge free of flicker and non-lighting can be generated regardless of the presence or absence of the impurity gas. Since the increase in the margin of the applied voltage can be achieved by reducing the firing voltage, the reduction of the firing voltage can be one of the solutions to the above problem.

Here, through consideration of the mechanism of secondary electron emission, a means for improving and improving the secondary electron emission rate will be searched.

The mechanism of secondary electron emission from a magnesium oxide (MgO) film, which is frequently used as a protective film of a conventional AC type PDP, is described by an Auger neutralization mechanism as is well known. That is, when the gas ions in the plasma approach the surface of the MgO film, the electrons present in the valence band of magnesium oxide fall to the ground state of the ions, and the valence band of magnesium oxide, which receives the energy generated at this time, Other electrons jump out of the MgO film to a vacuum level as secondary electrons. At this time, the energy gap of magnesium oxide is about 7
Since the energy is eV, the energy for secondary electron emission needs a large energy larger than the above value.

Therefore, in order to obtain a protective film having a higher secondary electron emission rate than conventional magnesium oxide based on the above-mentioned secondary electron emission mechanism, it is necessary to add an impurity element to magnesium oxide to obtain magnesium oxide. It is conceivable to increase the secondary electron emission rate by forming an impurity level in the energy gap of.

With respect to this point of view, a technique of adding an impurity element to a protective film of an AC type PDP is disclosed in Japanese Patent Application Laid-Open No. 56-61739 or Japanese Patent Application Laid-Open No. 8-23602.
No. 8 discloses this.

However, the prior art is a technique for improving the hygroscopicity of a magnesium oxide film by adding titanium dioxide (TiO2) or the like to the magnesium oxide film as a protective film. It does not give any suggestions or suggestions for improving or improving the rate.

On the other hand, in the prior art, in order to reduce the discharge starting voltage of a PDP and increase the discharge margin voltage, a part of magnesium in magnesium oxide as a protective film is changed to iron (Fe), chromium ( Although a technique of substituting with Cr) or vanadium (V) has been proposed, the prior art does not suggest any specific means for such substitution and no specific amount of the metal. .

Accordingly, the present invention has been made to solve the above problems, and has a more effective method for obtaining a protective film having a high secondary electron emission rate and capable of reducing a discharge starting voltage. A first object is to search for and provide means and conditions.

By providing a protective film capable of realizing the first object, flickering and non-lighting of discharge are suppressed and eliminated as compared with an AC PDP having a conventional protective film (MgO film). A second object is to provide an AC-type PDP and an AC-type PDP substrate capable of suppressing and removing the instability of the discharge.

In addition, a third object of the present invention is to provide a protective film material for an AC type PDP which can realize the first and second objects.

[0017]

According to a first aspect of the present invention, there is provided an AC type plasma display panel including an AC type plasma display panel facing a discharge space and having a protective film formed on a dielectric covering an electrode. The display panel, wherein the protective film has a valence of three in an oxidation state with magnesium oxide;
It is characterized by being formed as a solid solution with an oxide of a tetravalent or pentavalent metal element, and the concentration of the metal oxide is within a range of 0.1 mol% to 20 mol%. .

(2) The AC plasma display panel according to the invention of claim 2 is the AC plasma display panel according to claim 1, wherein the protective film is formed on a substrate of the AC plasma display panel. After formation, at least 30 ° C. in a vacuum or reducing atmosphere at a temperature in the temperature range of 350 ° C. to 500 ° C.
Characterized by being subjected to a heat treatment for one minute.

(3) An AC-type plasma display panel according to claim 3 is the AC-type plasma display panel according to claim 1 or 2, wherein the metal oxide is aluminum, zirconium, hafnium, vanadium. , Niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, cerium, neodymium, samarium, europium, gadolinium, or dysprosium.

(4) The substrate for an AC type plasma display panel according to the invention of claim 4 comprises an electrode,
In an AC plasma display panel substrate on which a dielectric and a protective film are sequentially formed, the protective film is made of magnesium oxide and a metal element whose valence in an oxidation state is trivalent, tetravalent or pentavalent. The oxide is formed as a solid solution, and the concentration of the metal oxide is within a range of 0.1 mol% to 20 mol%.

(5) The protective film material for an AC type plasma display panel according to the invention of claim 5 is a protective film material for an AC type plasma display panel, wherein the compound of magnesium and the valence of the oxidation state are trivalent, After being mixed with a compound of a tetravalent or pentavalent metal element at a predetermined ratio and press-molded, the mixture is heated at 1400 ° C. to 1
It is formed by heating at a temperature within a temperature range of 600 ° C.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 (Structure of AC PDP) FIG. 1 shows one light emitting cell 2 which is a basic unit of a pixel of an AC PDP according to Embodiment 1.
FIG. 2 is a longitudinal sectional view illustrating the structure of the extracted 0.

As shown in FIG. 1, in the PDP, a front panel 21 (display side) and a rear panel 22 face each other while maintaining a predetermined distance. A pair of electrodes composed of an X electrode 10 and a Y electrode (not shown), which are parallel to each other, are formed in stripes on the surface of the glass substrate 1 constituting the front panel 21 on the side of the rear panel 22. However, in FIG. 1, only the X electrode 10 of the pair of electrodes is illustrated due to the relationship in the illustrated direction. The dielectric layer 2 is formed so as to cover the entire surface of the pair of electrodes and the glass substrate 1. Further, a protective film 3 which is a feature of the present AC PDP is formed so as to cover the entire surface of the dielectric layer 2. This protective film 3 is formed as follows.

First, basic magnesium carbonate pentahydrate ((MgCO ₃ ) ₄ Mg (OH) ₂ .5H ₂ as a starting material
O) powder and iron oxide (Fe ₂ O ₃ ) powder are mixed at a predetermined ratio, put into a mold, and press-molded.
A pellet formed by baking for 30 minutes at a temperature of 400 ° C. or in the vicinity thereof is prepared. The heating temperature can be up to 1600 ° C. Then, after the pellets are pulverized into small blocks, the pellets are put into a vapor deposition crucible of an electron beam vapor deposition apparatus and used as a vapor deposition source of the protective film, thereby forming a protective film 3 having a thickness of about 7000 Å. In particular, in the present AC PDP, a predetermined heat treatment described later is performed after the formation of the protective film 3.

As described above, the protective film 3 contains iron oxide or iron element in magnesium oxide as a base material. In particular, in the protective film 3 according to the first embodiment, the concentration of the iron oxide is specified to be in the range of 0.1 mol% to 20 mol%, but the basis of the concentration range will be described later. Clarify in the description.

On the other hand, regarding the rear panel 22, the X electrodes 10 and the Y electrodes 10 are formed on the surface of the glass substrate 9 on the front panel 21 side.
An address electrode 8 is formed in a stripe shape in a direction perpendicular to the electrode, and a base layer 7 made of a dielectric (hereinafter, also referred to as a “dielectric layer 7”) covers the entire surface of the address electrode 8 and the glass substrate 9. Call) is formed. Further, as shown in FIG. 1, a stripe-shaped partition 6 for separating the emission color of the PDP is formed on the base layer 7 in parallel with the address electrode 8. Phosphor layer 5 is formed so as to cover the side wall surface and the surface of base layer 7. In case of AC type PDP with full color display,
As the phosphor layer 5, phosphors for red light emission, green light emission, and blue light emission are used.

The front panel 21 and the rear panel 22
Is arranged so that the top of the partition 6 is in contact with the protective film 3 of the front panel 21 in a parallel manner, and a sealing material (not shown) such as a low-melting glass is provided at the peripheral portions (not shown) of both panels. ). These front panels 2
1, a discharge space 23 formed by the back panel 22 and the sealing material is filled with, for example, a mixed gas of xenon and neon as the discharge gas 4.

The image display of the AC type PDP is performed by driving as follows.

First, a write discharge pulse is selectively applied only between the address electrode 8 and the X electrode 10 of the light emitting cell 20 to be displayed to generate a discharge. Due to this discharge, charges (wall charges) are accumulated on the protective film 3 in the light emitting cell 20 to be displayed. Next, when a sustain discharge pulse is applied between the X electrode 10 and the Y electrode, a discharge occurs between the X and Y electrodes in the light emitting cell having wall charges, and the ultraviolet light generated by the discharge excites the phosphor 5. Then, the light emitting cell 20 emits light. On the other hand, in the light emitting cell 20 where no wall charge is formed, even when the above-described sustain discharge pulse is applied, the light emitting cell 20 or the discharge space 23 is not used.
Does not exceed the substantial firing voltage, no discharge occurs and therefore no light emission occurs.

(Protective film material)
In selecting and evaluating the material (see FIG. 1), an evaluation AC-type PDP (hereinafter also referred to as “evaluation PDP”) having the structure of the light emitting cell 20 shown in FIG. 1 was produced.

The front panel 21 of this evaluation PDP is formed of a transparent conductive film on the above-mentioned surface of the glass substrate 1 having a length of 8 cm and a width of 10 cm, each having a width of 300 μm and a gap interval (between the X electrode 10 and the Y electrode). It has 24 pairs of X electrodes 10 and Y electrodes (a pair of electrodes) each having a gap of 70 μm. After forming a low-melting glass having a thickness of about 30 μm as the dielectric layer 2 covering the entire surface of the X electrode 10 and the Y electrode, a protective film 3 is formed on the dielectric layer 2 by the above-described film forming method. Formed. In particular, as the PDP for this evaluation, the concentration of iron oxide in magnesium oxide (which may be regarded as the amount of addition) is 0%.
P having a protective film (see protective film materials (a) to (h) in FIG. 2 described later) changed within a range of 25 mol% to 25 mol%.
Eight DPs were produced.

On the other hand, the back panel 22 has a length of 8 cm and a width of 1 cm.
Address electrodes 8 made of silver on a glass substrate 9 of 0 cm
Was formed, and an underlayer (dielectric layer) 7 was formed thereon.
On the underlayer 7, a width of 60 μm, a height of 130 μm, and a pitch of 4
A barrier 6 having a thickness of 00 μm was formed, and phosphors for red light emission, green light emission, and blue light emission were separately applied as phosphor layers 5 on the side wall surface of the partition 6 in the light emitting cell 20 and on the surface of the base layer 7.

The front panel 21 and the rear panel 22
Are sealed at the periphery thereof, and the inner space (discharge space 2)
3) After evacuating the inside, neon gas mixed with 5% xenon was sealed at 500 Torr. The display area of this panel is 3 cm long and 5 cm wide.

FIG. 2 shows the above-described eight types of evaluation PDPs having protective films (a) to (h) with different concentrations of iron oxide.
Firing voltage Vf and discharge sustaining voltage V measured for
It is a figure showing a result of sm. The measurement of the discharge starting voltage Vf and the discharge sustaining voltage Vsm is performed by using the X electrode 10 of the evaluation PDP,
5.2 kHz frequency, 64 μs pulse width between Y electrodes
The measurement was performed by applying the pulse voltage of c while changing the voltage value. Further, the values of the discharge start voltage Vf and the discharge sustaining voltage Vsm in FIG. 2 indicate average values in all the light emitting cells. Since the protective film (a) is a conventional protective film for comparison with the protective films (b) to (h), it is also referred to as “conventional protective film (a)” below.

As shown in FIG. 2, eight types of evaluation PDPs
Each of the evaluation PDPs having the protective films (c) to (g) has a lower discharge start voltage Vf and a lower discharge sustaining voltage Vsm as compared with the conventional evaluation PDP having the protective film (a). Has been reduced. This is due to the result that the secondary electron emission rate of the protective films (c) to (g) was improved and improved as compared with the conventional protective film (a). Here, such an effect will be described.

In the protective films (c) to (g), part of magnesium ions in magnesium oxide, which is an ionic crystal, is replaced with iron ions. Since the number of valence electrons in this iron ion is greater than that in magnesium, such extra electrons are free to move through the crystal. In other words, iron ions (elements of iron) in magnesium oxide act as donors,
A donor level is formed between energy gaps of magnesium oxide.

Therefore, in these protective films (c) to (g), when the gas ions in the plasma approach the surface of the protective film, the electrons existing in the donor level or the electrons in the valence band become the electrons. The ions fall to the ground state, and the energy generated at this time is transferred to the vacuum level by receiving (other) electrons at the donor level, whereby secondary electrons are emitted from the protective film. Therefore, the protective film (c) to
According to (g), emission of secondary electrons becomes easier as compared with the conventional protective film (a), that is, a high secondary electron emission rate can be obtained. At the same time, due to the high secondary electron emission rate, the above-described discharge starting voltage Vf and discharge sustaining voltage Vsm of the evaluation PDP having the protective films (c) to (g) are reduced.

On the other hand, as shown in FIG. 2, in the protective film (b) in which the concentration of iron oxide is 0.05 mol% and the protective film (h) in which the concentration is 25 mol%, the discharge starting voltage Vf or the discharge sustaining voltage Vsm is not reduced or small. The reason for this is that when the concentration of iron oxide is less than 0.1 mol%, the disturbance of the iron oxide on the crystal lattice of magnesium oxide is small, so that the secondary electron emission rate cannot be sufficiently improved. It is thought that it is not done. On the other hand, when the concentration of iron oxide is in a concentration range exceeding 20 mol%, the crystal lattice of magnesium oxide is excessively deformed.
It is considered that the movement of free valence electrons caused by the iron element is hindered, so that the amount of secondary electron emission decreases.

Therefore, from the measurement results shown in FIG. 2 and the above considerations, the concentration of iron oxide in magnesium oxide was 0.1% as the protective film 3 (see FIG. 1) of the AC PDP according to the first embodiment. It is concluded that a concentration in the range of mol% to 20 mol% is optimal.

Further, when the crystal states of the protective films (a) to (h) were evaluated by an X-ray diffraction method, it was found that the concentration of iron oxide was 0.1%.
Protective film (c) in a concentration range of 1 mol% to 20 mol%
In (g), the crystal orientation of a plane parallel to the glass substrate 1 (see FIG. 1) of each protective film is mainly a (111) plane, and the lattice spacing of magnesium oxide crystals in the protective film is iron oxide. It was found to change depending on the concentration. At this time, since the lattice spacing of the magnesium oxide crystal changes depending on the iron oxide concentration, it can be confirmed that the iron oxide is dissolved in the magnesium oxide. On the other hand, the above-mentioned effects cannot be obtained with iron oxide simply mixed in magnesium oxide without being dissolved in magnesium oxide. Therefore, in order to achieve a high secondary electron emission rate or reduce the firing voltage Vf or the sustaining voltage Vsm, magnesium ions (elements) in the crystal lattice of magnesium oxide must be replaced with iron ions (elements). That is, it is necessary that magnesium oxide and iron oxide are in a solid solution.

In this regard, the above-mentioned pellets, which are the material of the protective film 3, are formed by pressure molding of basic magnesium carbonate pentahydrate and iron oxide, and then fired at a temperature of 1400 ° C. in the atmosphere. Therefore, in such pellets, magnesium oxide and iron oxide are in a state of solid solution in advance. Therefore, by using this pellet as an evaporation source in the electron beam evaporation method, the protective film 3 (see FIG. 1) in a state where magnesium oxide and iron oxide in the film are dissolved can be formed. The disturbance caused by the metal element added in the film 3 can be made uniform.

Here, as a technique for adding a metal oxide to the protective film of an AC type PDP, Japanese Patent Application Laid-Open No. 52-11606 discloses a technique.
There is a prior art disclosed in Japanese Unexamined Patent Publication No. 7-107. According to the prior art, a technique of adding an alkaline earth element or a rare earth element into a protective film has been proposed in order to reduce the operating voltage of a PDP, but strontium (S) is used as a base material.
r) is different from the protective film 3 according to the first embodiment in that a compound is used.

In particular, the protective film 3 according to the first embodiment
By performing a heat treatment at 350 ° C. to 500 ° C. in a vacuum (about 10 ⁻³ to 10 ⁻⁶ Torr) or in a reducing atmosphere after the film formation, the secondary electron emission rate can be further improved and improved. I'm trying. Although the change in the microstructure of the surface of the protective film 3 due to this heat treatment is not clear, it is considered that such an effect is caused by the so-called activation effect due to rearrangement of the surface atoms after film formation.

As described above, according to the AC type PDP according to the first embodiment, since the protective film 3 having a high secondary electron emission rate is provided, flickering and non-lighting of discharge are suppressed / removed, and stable discharge is achieved. Can be obtained. Further, since the discharge starting voltage Vf or the discharge sustaining voltage Vsm is reduced, the margin of the applied voltage can be increased, and from this point, a stable discharge without flickering or non-lighting of the discharge can be caused. The effect that it can be obtained is obtained.

Although the basic magnesium carbonate pentahydrate and the iron oxide were selected as the raw materials (starting materials) of the protective film material, they are not limited to these substances. For example, instead of basic magnesium carbonate pentahydrate, magnesium oxide, magnesium hydroxide, magnesium oxalate, or the like may be used, and heat treatment (1400 ° C. to 1600 ° C. in the air) during pellet firing. Any material can be used as long as it can be changed into magnesium oxide. Further, iron oxalate or the like may be used instead of iron oxide.

As long as the concentration of iron oxide in the magnesium oxide is in the range of 0.1 mol% to 20 mol% and the protective film 3 can be in a solid solution state, electron beam evaporation is performed. In the method, the protective film 3 may be formed using different evaporation sources, or the protective film 3 may be formed by a film forming method other than the electron beam evaporation method.

In the above description, the surface discharge type A shown in FIG.
Although the C-type PDP has been described, the technical idea according to the first embodiment is that a PDP having a protective film facing a discharge space and formed on a dielectric covering an electrode is, for example, a counter discharge type. The present invention is also applicable to an AC type PDP. Further, for example, in consideration of the function of the protective film 3 in the AC type PDP having the structure shown in FIG.

In the above description, a case has been described in which the protective film 3 is made of magnesium oxide in which iron oxide is dissolved as a solid solution. Instead of iron oxide, a metal oxide whose valence in the oxidation state is trivalent, tetravalent, or pentavalent can also be used, and the above-described effects can be obtained. Specifically, cerium, aluminum, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, cobalt, nickel, neodymium, samarium,
Any oxide of europium, gadolinium or dysprosium is applicable.

FIG. 3 shows an AC type PD having magnesium oxide as a base material and a protective film in which these metal oxides are dissolved.
It is a figure showing the measurement result of discharge starting voltage Vf and discharge sustaining voltage Vsm of P. According to FIG. 3, both the voltages Vf and Vsm can be reduced as compared with the conventional protective film (a) (see FIG. 2) regardless of which metal oxide is added. The secondary electron emission rate can be improved and improved. At this time, the metal element (ion) forms a donor level in the band gap of magnesium oxide.
As in the case of iron oxide, a concentration range of 0.1 mol% to 20 mol% is optimal.

It is needless to say that the above effects can be exhibited by including at least one kind of the above metal oxides including iron oxide.

[0051]

(1) According to the first aspect of the present invention, A
Since the protective film of the C-type PDP is formed by solid solution of magnesium oxide and an oxide of a metal element whose valence in the oxidation state is trivalent, tetravalent or pentavalent, the magnesium element in the magnesium oxide ( Ion) is replaced with the above-mentioned metal element (ion). In addition, such a metal element has a valence of one of trivalent, tetravalent, and pentavalent in the oxidation state, and the number of valence electrons is larger than that of the magnesium element. Acting as a donor in magnesium, this extra electron forms a donor level in the energy gap of magnesium oxide. Since electrons in the donor level are more likely to be emitted to the vacuum level than electrons in the valence band, the secondary electron emission of the protective film is reduced by the number of electrons in the donor level. More than a protective film made of only magnesium oxide. Therefore, the AC type P according to the present invention
Since the DP includes a protective film having a high secondary electron emission rate, flickering and non-lighting of discharge can be suppressed or eliminated, and a stable discharge can be obtained.

Further, according to the present invention, the concentration of the above-mentioned metal oxide in the magnesium oxide is within the range of 0.1 mol% to 20 mol%. Voltage can be reduced. Therefore, since the margin of the applied voltage can be increased, a stable discharge without flickering or non-lighting of the discharge can be generated.

(2) According to the second aspect of the present invention, after the protective film is formed on the substrate of the AC type PDP, the protective film is formed at 350 ° C. to 500 ° C. in a vacuum or in a reducing atmosphere.
The heat treatment is performed at a temperature within the above temperature range for at least 30 minutes, so that the surface is reconstructed. Therefore, the secondary electron emission rate of the protective film is further increased, and an AC-type PDP capable of reliably exhibiting the effect (1) can be obtained.

(3) According to the third aspect of the invention, the same effect as the above (1) or (2) can be obtained.

(4) According to the invention of claim 4, AC
An electrode, a dielectric, and a protective film are sequentially formed on the surface of the type PDP substrate, and the protective film has a valence of trivalent, tetravalent, or pentavalent with magnesium oxide. Since the oxide of the metal element is formed as a solid solution and the concentration of the metal oxide is within the range of 0.1 mol% to 20 mol%, the above-mentioned (1) is provided by providing the AC type PDP substrate. ), An AC-type PDP exhibiting the same effects as in (1) can be obtained.

(5) According to the fifth aspect of the present invention, AC
The protective film material of the type PDP is obtained by mixing a magnesium compound and a metal element compound whose valence in the oxidation state is one of trivalent, tetravalent or pentavalent at a predetermined ratio and then pressing and molding the mixture. Since it is formed by heating at a temperature within the temperature range of 1400 ° C. to 1600 ° C. in the atmosphere, the metal element (or its oxide) in the added metal compound is dissolved in magnesium oxide. Therefore, by using the protective film material as an evaporation source, it is possible to form a solid solution and a protective film of uniform film quality, and furthermore, it is possible to make the disturbance by the metal element in the protective film uniform.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a structure of a light emitting cell of an AC PDP according to a first embodiment.

FIG. 2 shows the type of the protective film of the AC type PDP according to the first embodiment, the discharge starting voltage (Vf), and the discharge sustaining voltage (Vs).
FIG. 7 is a diagram showing a relationship with m).

FIG. 3 shows the type of the protective film of the AC PDP according to the first embodiment, the discharge starting voltage (Vf), and the discharge sustaining voltage (Vs).
FIG. 7 is a diagram showing a relationship with m).

[Explanation of symbols]

Reference Signs List 1 glass substrate, 2 dielectric layer, 3 protective film, 4 discharge gas, 5 phosphor, 6 partition, 7 underlayer (dielectric layer), 8
Address electrode, 9 glass substrate, 10 X electrode, 20
Light emitting cell, 21 front panel, 22 rear panel, 2
3 Discharge space.

(72) Inventor Takao Sawada 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (5)

[Claims] 1. An alternating-current plasma display panel comprising a protective film facing a discharge space and formed on a dielectric covering an electrode, wherein the protective film has a valence of 3 with magnesium oxide.
And a solid solution of an oxide of a metal element which is monovalent, tetravalent or pentavalent, and the concentration of the metal oxide is within a range of 0.1 mol% to 20 mol%. An AC type plasma display panel. 2. The AC plasma display panel according to claim 1, wherein the protective film is formed on a substrate of the AC plasma display panel, and then formed in a vacuum or a reducing atmosphere. An AC-type plasma display panel, wherein a heat treatment is performed at a temperature within a temperature range of 350 ° C. to 500 ° C. for at least 30 minutes. 3. The AC plasma display panel according to claim 1, wherein the metal oxide is aluminum, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, An AC-type plasma display panel comprising at least one of oxides of cobalt, nickel, cerium, neodymium, samarium, europium, gadolinium and dysprosium. 4. An AC plasma display panel substrate in which an electrode, a dielectric, and a protective film are sequentially formed on a surface of the substrate, wherein the protective film has magnesium oxide and a valence of 3 in an oxidized state.
And a solid solution of an oxide of a metal element which is monovalent, tetravalent or pentavalent, and the concentration of the metal oxide is within a range of 0.1 mol% to 20 mol%. Substrate for an AC type plasma display panel. 5. A protective film material for an AC type plasma display panel, wherein a magnesium compound and a metal element compound having a valence of 3, 4, or 5 in an oxidation state are present in a predetermined ratio. , And press-molded.
A protective film material for an AC type plasma display panel, which is formed by being heated at a temperature in a temperature range of ゜ C to 1600 ° C.