JP2003162962A - Plasma display panel and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PDP which is capable of displaying images having high brightness and high quality by preventing yellowing of a panel in PDP using silver electrodes with relatively simple techniques. <P>SOLUTION: When a silver electrode of a PDP is formed by means of a thick-film forming method, silver paste containing glass-frits, in which Ag particles and an oxide transition metal (containing more than one of oxide copper (CuO), oxide chromium (Cr<SB>2</SB>O<SB>3</SB>), oxide nickel (NiO), oxide manganese (Mn<SB>2</SB>O<SB>3</SB>), oxide cobalt (Co<SB>2</SB>O<SB>3</SB>), and oxide iron (Fe<SB>2</SB>O<SB>3</SB>) are added, or a silver film is used. As a result, the silver electrode film, of which the silver particles are sintered with a glass which contains the oxide transition metal, is formed. <P>COPYRIGHT: (C)2003,JPO

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 a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in the field of displays, there has been a demand for higher performance such as high-definition display (high-vision etc.) and flattening, and various researches and developments have been made to meet the demand. Typical flat displays include liquid crystal displays (LCD) and plasma display panels (PDP). Among them, PDPs are thin and suitable for large screens, and 50-inch class products have already been developed. Has been done.

PDPs are roughly classified into a direct current type (DC type) and an alternating current type (AC type). At present, the AC type, which is suitable for upsizing, is the mainstream. Generally, PDP is
In an AC surface discharge type PDP having a structure in which light emitting cells of respective colors are arranged in a matrix, for example, Japanese Patent Laid-Open No. 9-356.
As disclosed in Japanese Patent No. 28, the windshield substrate and the back glass substrate are arranged in parallel via a partition wall, and the display electrode pairs (scanning electrodes and sustain electrodes) are arranged in parallel on the windshield substrate. A dielectric layer is formed on the back glass substrate, address electrodes are arranged orthogonal to the scanning electrodes on the back glass substrate, and red and green are provided in the space partitioned by the partition wall between the plates. , A blue phosphor layer is provided, and a discharge gas is filled in to form a panel structure in which each color light emitting cell is formed. Then, when a voltage is applied to each electrode in the drive circuit to discharge, ultraviolet rays are emitted, and phosphor particles (red, green, blue) in the phosphor layer are emitted.
An image is displayed by receiving the ultraviolet rays and exciting and emitting light.

In such a PDP, a glass plate manufactured from a sodium borosilicate glass material by a float method is generally used for the front glass substrate and the back glass substrate, and Cr-is used for display electrodes and address electrodes. Cu-
Cr electrodes are also used, but relatively inexpensive silver electrodes are often used. This silver electrode is generally formed by a thick film method. That is, a silver paste containing silver particles, glass frit, resin, solvent, etc. is applied by patterning by screen printing, or silver particles, glass frit,
A film containing a resin or the like is attached by a laminating method and patterned. In any case, a firing process is performed at 500 ° C. or higher in order to remove the resin and fuse the silver particles together to increase the conductivity.

The dielectric layer is usually formed by coating a paste composed of a powder such as low melting point lead glass and a resin by a screen printing method, a die coat coating method or a laminating method, and heating and firing at 500 ° C. or higher. Formed by.

[0006]

By the way, in the PDP using the silver electrode as described above, Ag diffuses as ions into the glass substrate or the dielectric layer and is reduced in the substrate or the dielectric layer to generate Ag. It is known that yellowing is likely to occur due to the generation of colloids, and this yellowing causes a problem that the color temperature during white display is lowered when the PDP is driven and the image quality of the PDP is deteriorated. There is.

The yellowing of the glass substrate and the dielectric layer in this way causes a decrease in the brightness of the blue cell and a decrease in the color temperature during white display. For such a yellowing problem in the PDP, for example, Japanese Patent Laid-Open No. 10-255669
The publication discloses a technique of removing a surface layer of 1 μm or more and 1000 μm or less by mechanically polishing the surface of a glass substrate to be used.

This technique is considered to be effective in suppressing yellowing of the glass substrate, but it is extremely difficult to uniformly polish a large glass substrate such as that used in a PDP for 1 μm or more in a short time. For example, it takes several tens of minutes or more to polish the surface of a glass substrate by 1 μm with an Oscar type polishing apparatus. In addition, when the polishing is performed at 1 μm or more, variations in the thickness of the glass substrate are likely to occur.

Therefore, in a PDP using a silver electrode,
A new solution for suppressing yellowing is desired. In view of such a problem, the present invention provides a technique for suppressing yellowing of a panel in a PDP using a silver electrode relatively easily, thereby providing a PDP capable of displaying an image with high brightness and high image quality. The purpose is to do.

[0010]

In order to achieve the above object, in the present invention, firstly, when forming a silver electrode, a transition metal (Cu, Cu,
At least one selected from Cr, Co, Ni, Mn, and Fe is included. ).
Alternatively, when forming a silver electrode, silver and a transition metal oxide (CuO, CoO, NiO, Cr ₂ O ₃ , MnO, Fe ₂
Includes one or more of O ₃ . ) Containing glass. Silver and transition metal oxides (CuO,
1 out of CoO, NiO, Cr ₂ O ₃ , MnO, Fe ₂ O ₃
Including more than one species. ) Containing glass.

Secondly, according to the present invention, when a silver electrode is formed, silver is mainly used and metals (Ru, Rh, Ir, Os,
It contains any one or more of Re. ). Alternatively, when forming a silver electrode, silver and a metal oxide (RuO ₂ , RhO, IrO ₂ , OsO ₂ ,
It contains at least one of ReO _{2 and} PdO. ) Containing glass.

Thirdly, according to the present invention, when the silver electrode is formed, the surface of the silver particles is made of metal (Pd, Cu, Cr, Ni,
Ir, Ru, etc.) or metal oxides (SiO ₂ , Al ₂ O)
₃ , NiO, ZrO ₂ , Fe ₂ O ₃ , ZnO, In ₂ O ₃ , C
uO, TiO ₂ , Pr ₆ O _11, etc.) is used. Here, as a method of coating the surface of the silver particles with a metal or a metal oxide, there are the following methods.

On the surface of silver particles, by electroless plating,
Method of coating metal. A method of coating the surface of silver particles with a metal oxide or a metal by the mechanofusion method. In this method, the surface of silver particles is coated with a metal oxide by a sol-gel method. Further, the present invention is fourthly, in a glass substrate used for a PDP, a concentration of a metal ion having a reducing property with respect to Ag ion is 100 in a region from the surface to a depth of 5 μm.
It was decided to regulate it to 0 ppm or less.

Such a glass substrate for PDP is converted into Ag ions by a process of removing metal ions having a reducing property to Ag ions by an etching process or by heating the glass substrate for a normal glass substrate. On the other hand, it can be produced through a process of inactivating the reducibility of a metal ion having reducibility. Since yellowing of the glass substrate and the dielectric layer is suppressed by any of the first to fourth aspects, the brightness of the blue cells of the PDP can be improved and the color temperature during white display can be improved. The conductivity itself of the silver electrode can be sufficiently ensured in any of the first to fourth cases.

Now, the reason why the present invention can prevent yellowing will be described. FIG. 3 is a diagram for explaining a mechanism in which a glass substrate or a dielectric layer causes yellowing in a conventional PDP. As shown in this figure, it is considered that the yellowing of the glass substrate is performed through steps I to IV.

I. Ag in the electrode during the firing step when forming the silver electrode or the firing step when forming the dielectric glass layer
Are ionized. II. Ionized Ag ions diffuse into the surface of the glass substrate and into the dielectric layer. III. The diffused Ag ions are metal ions existing on the surface of the substrate glass or in the dielectric layer (metal ions having a reducing property with respect to Ag ions, and Sn ions mainly on the surface of the substrate glass, Are present in the atmosphere, and Na ions, Pb ions, etc. are present).

IV. The reduced Ag grows as Ag colloidal particles. Since this Ag colloidal particle has an absorption region at a wavelength of 400 nm, the substrate and the dielectric layer turn yellow. For the mechanism of yellowing of glass by silver, see p. Of the Glass Handbook (Asakura Shoten: published July 15, 1977).
166 shows that when Ag ⁺ and Sn ²⁺ coexist in the glass, a thermal reduction reaction of 2Ag ⁺ + Sn ²⁺
→ It is described that 2Ag + Sn ⁴⁺ is generated and that glass is colored by silver colloid. In addition, JE SHELBY and J.
VITKO. Jr Journal of Non Crystalline Solids Vol50
(1982) 107-117.

On the other hand, in the first case, the transition metal or transition metal oxide contained in the silver electrode is Ag.
Since the diffusion of ions is suppressed, the growth of Ag colloid particles is suppressed. Further, these transition metals or transition metal oxides are colored green to blue, but since green to blue have a complementary color relationship with yellow, this also prevents yellowing.

In the second case, the Ag ions in the glass substrate or the dielectric glass during firing are caused by the pinning effect of the platinum group metal (or Re) contained in the silver electrode or the oxide of these metals. Not only is it difficult to diffuse, but also Ag ions are less likely to be reduced. Therefore,
Growth of Ag colloidal particles is suppressed and yellowing is prevented.

In the third case, the metal oxide or metal present on the surface of the silver particles suppresses the diffusion of Ag ions during firing. Therefore, the growth of Ag colloidal particles is suppressed. In the fourth case, since the concentration of metal ions having a reducing property with respect to Ag ions is regulated to 1000 ppm or less in the vicinity of the surface of the PDP substrate, Ag ions diffused from the silver electrode to the substrate surface. However, it is hard to be reduced. Therefore, the growth of Ag colloidal particles is suppressed.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] FIG. 1 is a perspective view of a main part of an AC surface discharge PDP according to an embodiment, showing a part of a PDP display region. This PDP
Includes a front panel plate 10 and a rear panel plate 20 which are arranged in parallel with each other at intervals.

The front panel board 10 is a front glass substrate 11.
The display electrode 12 (scan electrode 12a, sustain electrode 12b) as the first electrode, the transparent dielectric layer 13, and the protective layer 14 are sequentially arranged on the opposing surface of. On the other hand, the back panel plate 20
The address electrode 22, the white dielectric layer 23, and the partition wall 30 as the second electrode are sequentially arranged on the facing surface of the rear glass substrate 21, and the phosphor layer 31 is disposed between the partition walls 30. The phosphor layers 31 are repeatedly arranged in the order of red, green and blue.

As the front glass substrate 11 and the rear glass substrate 21, glass plates manufactured by the float method are used. The space between the front panel plate 10 and the back panel plate 20 is partitioned by the partition walls 30 in stripes to form a discharge space 40, and the discharge space 40 is filled with a discharge gas.

The display electrode 12 and the address electrode 22
Are stripes, and the display electrode 12 is a partition wall 3
The address electrodes 22 are arranged in parallel with the partition walls 30 in a direction orthogonal to 0. A cell structure is formed in which cells for emitting red, green, and blue colors are formed at the intersections of the display electrodes 12 and the address electrodes 22. Figure 2
FIG. 3 is a partial cross-sectional view of an example of the front panel board 10.

On the front panel 10, a display electrode 12 is provided.
Each of a and 12b can be formed only by a silver electrode film as shown in FIG. 2 (a), or as shown in FIG. 2 (b), a conductive metal oxide such as ITO, SnO ₂ or ZnO can be formed. It is also possible to have an electrode configuration in which a thin silver electrode film is laminated as a bus electrode on a wide transparent electrode film made of a material,
Providing a wide transparent electrode for the display electrode is preferable for ensuring a large discharge area in the cell. On the other hand, it is easier to manufacture the display electrodes by using only the silver electrode film. Also,
In the case of a fine cell structure, since it is necessary to set the width of the display electrode to be small, for example, 50 μm or less, it can be said that it is suitable to form only the silver electrode film.

The transparent dielectric layer 13 is the front glass substrate 11
Is a layer made of a dielectric material, which is arranged so as to cover the entire surface on which the display electrode 12 of FIG. 1 is arranged. Lead-based low-melting glass is generally used, but bismuth-based low-melting glass or It may be formed of a laminate of lead low melting glass and bismuth low melting glass. The protective layer 14 is a thin layer made of magnesium oxide (MgO) and covers the entire surface of the transparent dielectric layer 13.

On the other hand, on the rear panel 20, the address electrode 22 is formed of a silver electrode film. The white dielectric layer 23 is similar to the transparent dielectric layer 13, but Ti is also used as a reflective layer that reflects visible light.
O ₂ particles are mixed. The partition wall 30 is made of a glass material and is provided on the surface of the white dielectric layer 23 of the rear panel 20 in a protruding manner.

As the phosphor material forming the phosphor layer 31, here, a blue phosphor: BaMgAl ₁₀ O ₁₇ : Eu green phosphor: Zn ₂ SiO ₄ : Mn red phosphor: (Y, Gd) BO ₃ : Eu will be used.

A drive circuit (not shown) is connected to the display electrodes 12 and the address electrodes 22 of the PDP to form a PDP display device. Then, by applying an address discharge pulse to the scan electrode 12a and the address electrode 22 in the drive circuit, wall charges are accumulated in the cell to be made to emit light, and then the display electrode pair 12a, 1
An image is displayed by repeating the operation of performing sustain discharge in the cells in which the wall charges are accumulated by applying the sustain discharge pulse to 2b.

[Production Method of PDP] A method of producing the PDP having the above structure will be described below. (Production of Front Panel Plate) A display electrode 12 is formed by forming a transparent electrode on the front glass substrate 11 if necessary, applying a silver electrode paste by screen printing, and then baking the paste. The silver paste used here will be described later in detail.

Then, so as to cover the display electrodes 12,
Glass powder having a softening point of 600 ° C. or lower (the composition is, for example, lead oxide [PbO] 70% by weight, boron oxide [B ₂ O ₃ ]
A transparent dielectric layer 13 is formed by applying a paste containing 15% by weight and silicon oxide [SiO ₂ ] 15% by weight) by a die coating method or a screen printing method and baking it.

When the transparent dielectric layer 13 is formed by the die coating method, first, the dielectric glass is pulverized with a jet mill to an average particle size of 1.5 μm. Next, this glass powder 3
5% by weight to 70% by weight and ethyl cellulose 5% by weight to
A binder for 30 wt% to 65 wt% of terpineol, butyl carbitol acetate, or pentanediol containing 15 wt% is well kneaded with a jet mill to prepare a die coat paste. During the paste kneading, an anionic surfactant may be added in an amount of about 0.1 wt% to 3.0 wt% for the purpose of improving the dispersibility of glass powder and the effect of preventing sedimentation.

Then, the paste viscosity is adjusted to 300,000 centipoise or less and applied. Next, after drying, it is fired at a temperature (550 ° C to 590 ° C) slightly higher than the softening point of the glass. On the surface of the transparent dielectric layer 13 thus formed,
For example, the MgO protective layer 14 is formed by the sputtering method.

(Preparation of Rear Panel Plate) Rear glass substrate 2
1, an address electrode 22 was formed by a method of screen-printing a silver electrode paste and then firing it, and TiO ₂ particles (average particle diameter: average particle diameter of 0.1) were formed on the address electrode 22.
μm to 0.5 μm) and dielectric glass particles (average particle diameter:
1.5 μm) is applied by a screen printing method and baked to form the white dielectric layer 23, and the glass paste for the barrier ribs is applied by a screen printing method and then baked, or by sandblasting. The partition 30 is formed by the method.

Then, a phosphor paste (or phosphor ink) for each color of red, green and blue is prepared, and this is used as a partition 3
It is applied to the gap between 0 and baked in air (for example, 500
The phosphor layer 31 of each color is formed by baking at 10 ° C. for 10 minutes.
To form. The phosphor paste is generally applied to the space between the partition walls by a screen printing method. However, when the panel structure is fine, a phosphor ink of about 1.0 Pas (Pascal, sec) is jetted from a nozzle. It is preferable to use a scanning method (ink jet method) because uniform coating can be performed accurately.

For each color phosphor layer 31, a sheet of a photosensitive resin containing a phosphor material of each color is prepared and attached to the surface of the rear glass substrate 21 on the side where the partition wall 30 is arranged, and photolithography is performed. It can also be formed by a method of removing unnecessary portions by patterning and developing with. (Sealing of front panel plate and back panel plate) Either one or both of the front panel plate 10 and the back panel plate 20 thus produced are coated with glass for sealing (glass frit), and calcined to seal. A glass layer is formed, and the display electrodes 12 of the front panel plate 10 and the address electrodes 22 of the rear panel plate 20 are laminated so as to face each other at right angles.
Sealing is performed by heating 0 and 30 to soften the sealing glass layer.

Then, the gas is released from this internal space by firing the panel while exhausting the internal space of the attached panel plate. Then, this internal space is evacuated to a high vacuum (1.1 × 10 ⁻⁴ Pa (8 × 10 ⁻⁷ Torr)), and then a discharge gas is filled in to produce a PDP. (Characteristics of Display Electrode 12 and Address Electrode 22 and Manufacturing Method Thereof) The display electrode 12 is, as described above, an electrode in which a thin silver electrode film is laminated as a bus electrode on a transparent electrode film, or silver. Although it is composed of only an electrode film, this silver electrode film is characterized.

That is, a conventional general silver electrode is generally one in which a mixture of Ag particles and a glass component is fired, but the silver electrode film of the present embodiment has the following (1), (2)
Has any of the characteristics. (1) Mainly composed of Ag, and a transition metal (including at least one of copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), manganese (Mn), and iron (Fe)). It is a silver electrode film formed of an Ag alloy containing.

The silver electrode film made of such an Ag alloy is
It can be formed by a thin film forming method or a thick film forming method. When the thin film is formed by the thin film forming method, it can be formed by forming the Ag alloy by the thin film forming method (sputtering method) and patterning it in a stripe shape by the photolithography method.

FIG. 4 is a diagram for explaining a method of forming a silver electrode film made of this Ag alloy. Front glass substrate 11
An alloy of Ag and a transition metal (for example, Ag-C
u alloy) is used as a target to form a silver electrode film made of Ag alloy by the sputtering method (FIG. 4).
(a), (b)). After that, a photoresist is applied on the entire surface of the silver electrode film (FIG. 4C), and a region where an electrode is to be formed is covered with a pattern mask and exposed (FIG. 4C).
(d)). Then, by developing this, the photoresist in the exposed portion is removed. In this state,
By etching the silver electrode film, a striped silver electrode film is formed on the front glass substrate 11.

As described above, the silver electrode composed of a dense thin film of Ag alloy is formed. Next, FIG. 5 shows a case where the silver electrode film made of Ag alloy is formed by the thick film forming method.
This will be described with reference to FIG. As shown in FIG.
A photosensitive silver paste (or a photosensitive silver film) obtained by mixing particles (for example, Ag-Cu alloy particles) made of an alloy of a transition metal with a glass frit and a photosensitive resin,
The entire surface is coated on the front glass substrate 11 (FIG. 5B), and is patterned into stripes by the photolithography method (or lift-off method) described in (1) above (FIG. 5C). A body is formed (FIG. 5 (d)).
Then, a silver electrode is formed by firing this silver electrode precursor (FIG. 5E).

Alternatively, as shown in FIG. 6, Ag alloy particles and
Screen printing silver paste, including glass frit
It is applied in a stripe pattern by the printing method (Fig. 6).
(B)), An electrode precursor is formed (FIG.6 (c)). That
By firing this silver electrode precursor.
Formed (FIG. 6D). Formed by thick film formation method
As shown in FIG. 7 (a), the formed silver electrode is made of Ag alloy particles.
Is sintered with glass frit
It (2) Silver particles are oxides of transition metals (copper oxide (Cu
O), chromium oxide (Cr₂O₃), Nickel oxide (Ni
O), manganese oxide (Mn₂O₃), Cobalt oxide (Co
₂O₃), Iron oxide (Fe₂O₃). )
It is a silver electrode film obtained by sintering with a glass containing.

For such a silver electrode film, a silver paste or a silver film containing Ag particles and a glass frit added with an oxide of a transition metal is used, and the silver electrode film shown in FIG.
It can be formed by a thick film forming method similar to that described above. Here, as a form of adding the transition metal oxide to the glass frit, the composition of the glass frit may contain the transition metal oxide, or the glass frit powder may be mixed with the transition metal oxide powder. You may add.

In each case, the silver electrode after sintering was as shown in FIG.
As shown in (b), the Ag particles are sintered by a glass frit containing a transition metal oxide. When forming a laminated electrode in which a silver electrode film is laminated on a transparent electrode film, the silver electrode may be formed by any of the above methods after forming the transparent electrode film. When the transparent dielectric layer 13 is formed on the display electrode 12 as described above, the two are closely coupled.

As with the display electrode 12, the address electrode 22 also has the characteristics (1) or (2). (Effect of this embodiment) P with a conventional silver electrode
Compared with DP, the PDP of this embodiment suppresses yellowing of the panel.

The reason is that, in the conventional silver electrode, as shown in FIG. 3 (II), Ag ions diffuse into the glass substrate or the dielectric layer when firing the electrode or the dielectric layer. Although it is easy, as in the present embodiment, Cu, Cr, Co, Ni and M which are transition metals are contained in the silver electrode.
When n, Fe or oxides of these transition metals are contained, these transition metals suppress the diffusion of Ag ions.

Next, these transition metals and transition metal oxides have the property of coloring glass from green to blue, but since this green to blue has a complementary color relationship with yellow, Ag
Ability to counteract yellowing due to colloids (ie L * a * b *
It also has a function of shifting the b value of the color difference due to the color system in the negative direction). The content of the transition metal in the Ag alloy is 5 in order to obtain a sufficient yellowing suppression effect.
The content of the transition metal oxide in the glass frit is preferably 5% by weight or more.

However, if the proportion of the transition metal component in the Ag alloy is too large, the resistance value of the silver electrode tends to be high, and therefore, in order to secure the conductivity of the silver electrode, it can be suppressed to 20% by weight or less. desirable. Further, from the viewpoint that when the proportion of the transition metal component increases, the light transmittance of the panel tends to decrease due to the coloring by the transition metal, it is desirable to suppress it to 20% by weight or less.

On the other hand, when the amount of the transition metal oxide contained in the glass frit is too large, the light transmittance of the panel is apt to decrease due to the coloring by the transition metal, so that it is desirable to keep it to 20% by weight or less. Further, according to the present embodiment, as the transition metal or transition metal oxide to be added, PDP production conditions and materials can be obtained from among the several metals and several transition metal oxides listed above. An appropriate one may be selected in consideration of ease of use. Therefore, also in this respect, the practical value is high.

[Example 1]

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

No. shown in Table 1 The PDPs 1 to 12 have Ag and transition metals (Cu, Co, Ni, C) when forming the display electrode (first electrode) and the address electrode (second electrode).
This is an example in which a silver electrode is formed by a sputtering method and a photolithography method using an Ag alloy containing r, Mn, Fe). No. shown in Table 2 14 to 25, N shown in Table 3
o. Nos. 27 to 38 and Nos. 40-51 PDP
The oxide of the transition metals in the glass frit consisting of _{PbO-B 2 O 3 -SiO 2} (CuO, CoO, NiO, Cr
_This is an example in which a display electrode (first electrode) and an address electrode (second electrode) are formed by using an Ag paste to which ₂ O ₃ , MnO, Fe ₂ O ₃ ) is added.

Among these, No. 2 in Table 2 was used. 14-25 includes a photosensitive silver paste [Ag particles, PbO-B ₂ O ₃ -SiO
_2- MO (where MO is an oxide of a transition metal)
It contains a glass frit and a photosensitive organic component (consisting of a photosensitive monomer, a photosensitive polymer, a photopolymerization initiator, a sensitizer and an organic solvent). ], And the silver electrode was formed by patterning by the photolithography method and baking at 550 degreeC.

Further, in Table 3, No. In 27-38, print
Ag paste [Ag particles and Bi ₂O₃-B₂O₃-Si
O₂-MO (where MO is a transition metal oxide)
Glass frit and organic vehicle (ethyl cellulose
Butyl carbitol acetate and terpineol
Consisting of) and. ] By the screen printing method
Fabricate and fire at 550 ° C to form silver electrodes
It is a thing.

Further, in Table 4, No. In Nos. 40 to 51, an indium oxide-tin oxide (ITO) film was formed by a sputtering method, and then patterned by a photolithography method to form a wide ITO transparent electrode, and a photosensitive ITO was formed on the transparent electrode. Display electrode (first electrode) by applying a conductive silver paste, patterning by photolithography, and baking at 550 ° C. to form a silver electrode
Is formed.

Each of these PDPs was manufactured with the following specifications. The cell size is 42 inches, and the height of the partition wall 30 is 0.15 mm according to the VGA display.
The interval (cell pitch) between the partition walls 30 was set to 0.36 mm. The distance d between the display electrode pairs was set to 0.10 mm, and the width of the silver electrode was set to 100 μm. When forming a transparent electrode, its width was set to 150 μm.

Further, as the discharge gas, the content of Xe is
5% by volume of Ne-Xe mixed gas was introduced at a filling pressure of 80,000.
It was sealed with Pa (600 Torr). Transparent dielectric layer 13
PLS-3244 (PbO manufactured by Nippon Electric Glass Co., Ltd.)
-B ₂O₃-SiO₃-CaO-based glass)
Method or screen printing method
The thickness was 30 μm to 40 μm.

The MgO protective layer 14 was formed by the sputtering method and had a thickness of 1.0 μm. The white dielectric layer 23 on the back panel side was formed by applying the same glass as the transparent dielectric layer 13 to which titanium oxide (TiO ₂ ) was added by the die coating method and baking. No. 13, 2
The PDPs Nos. 6, 39, and 52 are according to the comparative example, and neither transition metal is contained in the Ag particles nor the glass frit.
It is the same as o1-12, 14-25, 27-38, 40-51.

[Experiment 1] The a value and the b value [JIS Z8730 color difference display method] were measured using a color difference meter [Nippon Denshoku Industries Co., Ltd. product number NF777] for the front panel plate 10 in the process of producing PDPs 1 to 52. The a value and the b value serve as indicators of the degree of coloring and the coloring tendency of the front panel 10, and the larger the a value in the + direction, the stronger the red color, and the larger the a value, the stronger the green color. On the other hand, as the b value increases in the + direction, yellow becomes stronger, and as it increases in the − direction, blue becomes stronger.

When the a value is in the range of -5 to +5 and the b value is in the range of -5 to +5, almost no coloring (yellowing) of the glass substrate is seen by the naked eye, but the b value is 10. If it exceeds, yellowing will be noticeable. In addition, the above No. 1 to 52 P
Regarding DP, the color temperature at the time of displaying all white on the screen was measured with a multi-channel spectrometer [MCPD-7000, Otsuka Electronics Co., Ltd.].

Tables 1 to 4 above show the results of these experiments. (Discussion) Sample No. of the comparative example. In Sample Nos. 13, 26, 39, and 52, the b value is +14 to +16.2, which indicates that the yellowing has occurred considerably. 1
-12, 14-25, 27-38, 40-51, b
The value is as low as 0 to +4.5, which shows that it is an excellent PDP with little yellowing.

In the PDP of the comparative example, the color temperature value is 6
290 to 6500 ° K, while the PD of the example
In P, the color temperature is as high as 8300 to 9200 ° K. This indicates that the PDP of the example has better color reproducibility and vivid display than the PDP of the comparative example. For the glass forming the transparent dielectric layer, see P.
Similar results were obtained when Bi2O3 or ZnO dielectric glass was used in addition to bO.

[Embodiment 2] This embodiment is the same as Embodiment 1 above, except that the type of metal added to the silver electrode is different, and platinum group metal or Re or oxidation of these metals is used. Things have been added. That is, in the present embodiment, the silver electrode film used for the display electrode 12 and the address electrode is mainly composed of (1) Ag and contains a metal (ruthenium (Ru), rhodium (Rh), iridium (I).
r), osmium (Os), 1 of rhenium (Re)
Including more than one species. ) Or a silver electrode film formed of an Ag alloy, or (2) Ag particles are metal oxides (ruthenium oxide (RuO ₂ ), rhodium oxide (RhO), iridium oxide (IrO ₂ ), osmium oxide). (OsO ₂ ),
Rhenium oxide (ReO ₂ ) or palladium oxide (P
dO) is included. ) Is a silver electrode film obtained by sintering with a glass containing.

Regarding the method for producing such a silver electrode,
In the case of (1), it can be formed by either a thin film forming method or a thick film forming method, and in the case of (2), it can be formed by a thick film forming method. The details are the same as those described in the first embodiment. In this way, the metal (R
It includes at least one of u, Rh, Ir, Os and Re. ), Or a metal oxide (RuO ₂ , RhO, IrO ₂ ,
At least one of OsO ₂ , ReO ₂ , and PdO is included. ) Is added, the yellowing of the panel is suppressed. The reason is that Ag ions are less likely to diffuse into the glass substrate or the dielectric layer during electrode firing or dielectric layer firing due to the pinning effect of the above-mentioned metals (mainly platinum group) or oxides of these metals. At the same time, Ag ions are less likely to be reduced (that is, the progress of Steps II and III in FIG. 3 is suppressed), which suppresses the growth of Ag colloidal particles and prevents yellowing. .

Metals (Ru, Rh, I in Ag alloy)
The content of r, Os, Re) and the content of the metal oxide in the glass frit are preferably 5% by weight or more and 20% by weight or less for the same reason as in the first embodiment. It is desirable to suppress it. Further, according to the present embodiment, as the metal or metal oxide to be added to Ag, the production conditions and materials of PDP are available from the several metals and the several metal oxides listed above. An appropriate one may be selected in consideration of ease and the like. Therefore,
Also in this respect, the practical value is high.

(Regarding Simultaneous Firing of Silver Electrode Precursor and Dielectric Precursor Layer) When a silver electrode film is formed by a thick film forming method,
As described below, when the silver electrode precursor and the dielectric precursor layer are co-fired, a further yellowing suppression effect can be obtained. FIG. 8 is a process diagram illustrating a simultaneous firing method for a silver electrode precursor and a dielectric precursor layer.

Step 1: Silver electrode precursor forming step Stripe silver electrode precursors 120a, 120b are formed on the front glass substrate 11 by using Ag paste or silver electrode film, as shown in FIG. 8 (a). To form. The organic binder contained in the silver electrode paste to be used is preferably a cellulose compound such as ethyl cellulose or an acrylic polymer such as methyl methacrylate, but is not limited thereto.

When the Ag paste is used, it may be applied to the electrode pattern shape by screen printing and then dried, or it may be solidly applied and dried by screen printing or die coating, followed by photolithography. The patterning may be performed by a method (or lift-off method). On the other hand, the silver electrode film is obtained by processing the same components as the above Ag paste into a film by using, for example, a blade method. When this silver electrode film is used, it may be applied by solid coating and then patterned by a photolithography method (or a lift-off method).

Second Step: Dielectric Precursor Layer Forming Step A dielectric precursor layer 130 is formed so as to cover the silver electrode precursor 120 formed in the electrode pattern shape as described above (FIG. 8B). ). The dielectric precursor layer 130 is formed by applying a solvent and a dielectric paste containing glass and an organic binder as essential components, using a screen printing method or a die coating method, and drying. In addition, a dielectric film obtained by processing the above essential components into a film,
It can also be formed by sticking by a laminating method.

Third Step: Resin Decomposition Step In the baking furnace, the resin contained in the silver electrode precursors 120a and 120b and the dielectric precursor layer 130 is heated to a temperature at which it decomposes to burn off the resin. Preferably, the resin in the dielectric precursor layer 130 is completely decomposed by slowing the temperature rising rate or stopping the temperature rising above the decomposition start temperature of the resin (FIG. 8C).

In this step, an oxidizing gas such as oxygen may be supplied to accelerate the oxidation, or a reducing gas such as hydrogen may be supplied to prevent the oxidation of the metal. In addition, in order to promote oxidation at a lower cost,
By supplying dry air or reducing the pressure of the heating atmosphere, the gas generated by the oxidation of the resin may be promptly removed to the outside of the system.

Fourth Step: Firing Step The glass component contained in the silver electrode precursors 120a and 120b and the glass component contained in the dielectric precursor layer 130 are further heated after the heat treatment step. Soften. Then, the glass component is left to stand for several minutes to several tens of minutes at a temperature equal to or higher than the softening point of the glass component to be sintered.

After the firing process is completed, the temperature is lowered to form the electrodes 12a and 12b and the transparent dielectric layer 13 (FIG. 8 (d)). (Effect of Simultaneous Firing of Silver Electrode Precursor and Dielectric Precursor Layer) Conventionally, when a silver electrode is generally formed on a glass substrate, after the silver electrode precursor is formed on the glass substrate, it is fired. However, in this case, since the silver electrode precursor is baked in a state where it is not coated, Ag ions are likely to diffuse onto the glass substrate.

Since a reducing substance such as tin is present on the glass substrate, the diffused Ag ions are reduced to silver, Ag colloids are easily generated, and yellowing is likely to occur.
On the other hand, if the silver electrode precursor and the dielectric precursor layer are fired at the same time as described above, when the silver electrode precursor is fired, it is in a state of being covered with the dielectric precursor layer, Fewer Ag ions are diffused on the glass substrate.

Here, Ag ions are also diffused in the dielectric precursor layer, but since there are less reducing substances in the dielectric precursor layer than on the glass substrate, the Ag ions are reduced. Hateful. Therefore, if the silver electrode precursor and the dielectric precursor layer are co-fired, the production of Ag colloid is suppressed and yellowing is suppressed as a whole.

[Example 2]

[0080]

[Table 5]

[0081]

[Table 6]

Sample No. shown in Table 5 61-No. 72
The PDP of the present invention is based on the above-described second embodiment, and at least one of Ag and metal (Ru, Rh, Ir, Os, Pd, Re is used.
Including seeds. ) Is used to form the display electrode (first electrode) and the address electrode (second electrode). However, the sample No. 66 is a reference example using Ag-Pd alloy powder.

Sample No. 61-No. The method of manufacturing the front panel plate at 72 is as follows. Ag alloy powder and an organic vehicle containing ethyl cellulose, butyl carbitol acetate and terpineol as main components, Bi
A glass frit containing ₂ O ₃ —B ₂ O ₃ —SiO ₂ as a main component was kneaded at a predetermined weight ratio, and an electrode precursor was patterned by a screen printing method.

Then, a glass paste for a dielectric material (Pb as shown in Table 5) was formed so as to cover the above electrode precursor.
_{O-B 2 O 3 -SiO 2} -CaO -based glass, Bi ₂ O ₃ -Z
nO-SiO ₂ based glass or ZnO-B ₂ O ₃ -SiO ₂
-K ₂ O based glass) was formed by a printing method to a thickness of about 30 μm. Then, the electrode precursor and the dielectric precursor layer are formed into 59 layers.
A front panel plate was produced by heating and firing at 0 ° C.

Sample No. shown in Table 6 74-85 PD
P is a display electrode (first electrode) using a glass frit containing RuO ₂ , ReO ₂ , IrO ₂ , RhO, OsO ₂ or PdO when forming a silver electrode based on the second embodiment. This is an example in which an address electrode (second electrode) is formed. This sample No. In Nos. 74 to 85, a silver electrode was formed by a photolithography method using a photosensitive Ag paste (photo Ag paste). Glass frit in the photosensitive Ag _{paste, PbO-B 2 O 3 -SiO} 2
_{System, Bi 2 O 3 -B 2 O} 3 -SiO 2 system or P ₂ O ₅ -B ₂ O ₃
RuO ₂ , ReO ₂ and Ir are added to —SiO ₂ glass powder.
O _2, RhO, using what OsO _2, PdO was added each 5 wt%, except for it, the sample No.
61-No. A front panel was prepared in the same manner as 72.

Sample No. Nos. 73 and 86 are comparative examples, and Ag particles do not contain Ru, Re, Ir, Rh, and Os, and the glass frit also has RuO ₂ , ReO ₂ , and I.
In this example, rO ₂ , RhO, and OsO ₂ are not included. Table 5,
Sample No. of Table 6 61-No. 86, regarding the cell size of the PDP, the dielectric layer, the protective layer, and the discharge gas,
The settings were made in the same manner as in Example 1 above.

(Experiment 2) With respect to the front panel plate 10 in the process of producing the PDPs No. 61 to 86, the experiment 1
The a value and the b value were measured in the same manner as in. Also, the above N
With respect to the PDPs of o61 to 86, the color temperature was measured when the screen was displayed in all white. The experimental results are shown in Table 6.

(Discussion) Sample No. of the comparative example. In Nos. 73 and 86, the b value is much higher than 10, indicating that the panel is considerably yellowed, whereas the sample Nos. In 61 to 72 and 74 to 85, the b value is 0.
It is a low value of up to +4.0, which shows that it is an excellent PDP with little yellowing.

It can also be seen that the color temperature value of the PDP of the comparative example is 6500 ° K or less, whereas the color temperature of the PDPs of the examples and reference examples is as high as 8300 to 9200 ° K. The sample No. of the reference example. 66 is the sample No. of the comparative example. Although the b value is considerably smaller than that of No. 73, it can be seen that the b value is slightly higher than that of Nos. 61 to 65 and Nos. 67 to 71 of the examples.

[Embodiment 3] This embodiment is the same as the above embodiment.
Of the display electrode 12 and the address electrode.
When forming the pole 22, a metal or metal oxide is formed on the surface.
The point that a silver electrode film is formed using Ag particles coated with
Is different. Here, the preferred metal for surface coating
Then, palladium (Pb), copper (Cu), nickel
(Ni), cobalt (Co), chromium (Cr), lodge
Mu (Rh), Iridium (Ir), Ruthenium (Ru)
As a preferred metal oxide to be surface-coated,
Aluminum oxide (Al₂O₃), Nickel oxide (N
iO), zirconium oxide (ZrO₂), Cobalt oxide
(CoO), iron oxide (Fe₂O ₃), Zinc oxide (Zn
O), indium oxide (In₂O₃), Copper oxide (Cu
O), titanium oxide (TiO₂), Praseodymium oxide
(Pr₆O₁₁), Silicon oxide (SiO ₂) Is mentioned.

A method of forming such a silver electrode film will be described. First, Ag particles are coated with the above metal or metal oxide. As the coating method, there are three types of electroless plating method, mechanofusion method and sol-gel method as described below. Electroless plating method: For example, when Pd is attached to the surface of Ag particles, the Ag particles are put into an aqueous solution of palladium chloride (PbCl ₂ ) and the mixture is agitated, as shown in FIG.
As shown in, Pd particles are attached to the surface of Ag particles.

Cu, Ni, Co, Cr, Rh, Ir, R
In the case of adhering a metal such as u, an aqueous solution of such a chloride is prepared, Ag particles are added, and the mixture is stirred.
These metals can be deposited on Ag particles.
In this case, in order to increase the force of adhesion of metals such as Cu, Ni, Co, Cr, Ir and Ru to the Ag particles, first, Pd particles are attached using an aqueous solution of palladium chloride, and then these metals are attached. It is good to let

Mechanofusion method: A metal oxide or a metal powder is mixed with Ag powder and mechanical energy is applied to cause a mechanochemical reaction on the surface of the Ag particles.
This is a method of adhering onto Ag particles. According to this mechanofusion method, a metal oxide can be deposited on the surface of Ag particles to form a metal oxide layer, or metal particles can be deposited on the surface of Ag particles to form a metal layer. It is possible.

Specifically, Ag particles and the above-mentioned metal oxide powder (for example, SiO ₂ having an average particle diameter of 0.1 μm) are prepared. The Ag particles are preferably spherical. Then, it is processed by a mechanofusion device (for example, mechanofusion device AMS manufactured by Hosokawa Micron Co., Ltd.). As a result, as shown in FIG. 9B, the metal oxide, which is a child particle, fuses with the surface of the Ag particle, which is a mother particle, and the mother particle is covered with the child particle.

Sol-gel method: Ag particles are charged with an alkoxide of a metal oxide in an alcohol solution, and this is hydrolyzed to attach the metal oxide. That is,
Ag powder and metal alkoxide M. (O.R) _n (where M is a metal, O is oxygen, R is an alkoxy group, n is an integer,
For example, Si (OC ₂ H ₅ ) ₄ ) is put into an alcohol solution to hydrolyze the metal alkoxide, and as shown in FIG. 9C, the metal oxide layer ( SiO ₂ layer) is formed.

As described above, a silver electrode is prepared by using Ag particles in which a metal or a metal oxide is coated (attached) on the surface of Ag particles. Here, when the silver electrode is manufactured, a photosensitive silver paste (or a photosensitive silver film) is manufactured and the photolithography method (or lift-off method) is used, as described in FIG. 5 of the first embodiment.
Alternatively, as described in FIG. 6 of the first embodiment, a silver paste for printing may be prepared and a screen printing method may be used.

The silver electrode thus produced is shown in FIG.
As shown in (d), the Ag particles whose surface is coated with a metal or metal oxide layer are sintered with a glass frit. (Effects of this Embodiment) In this embodiment,
Since the surface of the Ag particles used for forming the silver electrode is coated with a metal or a metal oxide, Ag ions are less likely to diffuse from the Ag particles to the surroundings. Therefore, in the step of firing the electrode or the step of firing the dielectric layer, generation of Ag colloid on the surface of the glass substrate or the dielectric layer is suppressed.

Since the above-mentioned metals and metal oxides are the same as the transition metals or transition metal oxides used in the first embodiment or the metals or metal oxides used in the second embodiment, The yellowing suppression effect by the complementary color of the transition metal (transition metal oxide) and the diffusion suppression effect of Ag ions (suppressing the progress of step II in FIG. 3) described in 1 or the metal (metal oxidation described in the second embodiment. Object) has an effect of suppressing reduction of Ag ions (inhibition of progress of step III in FIG. 3). Further, in the present embodiment, since these metals and metal oxides are unevenly distributed on the surface of the Ag particles, they are unevenly distributed on the surface of the Ag particles. Therefore, even if the amount added to Ag is small, a large Ag colloid is obtained. A production suppression effect can be obtained.

Therefore, according to this embodiment, it is possible to suppress the yellowing of the panel while ensuring the conductivity of the silver electrode. Regarding the amount of coating the surface of the Ag particles with a metal or a metal oxide, in order to sufficiently suppress the diffusion of Ag ions, the average thickness of the coating layer (if the particles are attached to the surface, the average thickness of the coating is Thickness when converted to 0.1 μm
It is desirable to set the above. On the other hand, if the thickness of the coating layer is too large, the conductivity becomes low, so it is desirable to set the thickness of the coating layer to 1 μm or less.

In the present embodiment, the metal or metal oxide to be coated is selected from the metals and metal oxides listed above in consideration of the manufacturing conditions of PDP, availability of materials, and the like. You may select an appropriate one. Therefore,
Also in this respect, the practical value is high. [Example 3]

[0101]

[Table 7]

[0102]

[Table 8]

Samples No. 91 to No. 11 shown in Tables 7 and 8
The PDP of No. 2 is a display electrode (first electrode) / address electrode (second electrode) using Ag particles (average particle size 2 μm) coated with metal or metal oxide according to the present embodiment. Was formed. In this example, when the Ag particles were coated with a metal, the average thickness of the metal layer was in the range of 0.1 μm to 1.0 μm, and when the Ag particles were coated with the metal oxide, the average thickness of the metal oxide layer was 0.1 μm to 1.0 μm. The average thickness was set within the range of 0.1 μm to 0.5 μm.

When the photolithography method is used, a powder of Ag particles coated with a metal or a metal oxide,
And PbO-B ₂ O ₃ -SiO ₂ based glass frit, photosensitive binder (binder resin as a main component, a photopolymerization initiator, photosensitive monomer, a solvent and minor subcomponent, dyes, plasticizers, polymerization inhibitors, etc. And a binder contained therein) were kneaded with a triple roll to prepare a photosensitive silver paste. Then, after applying this photosensitive silver paste, patterning was performed by a photolithography method, and baking was performed at 450 ° C. to 600 ° C. to form a silver electrode.

In the case of the screen printing method, a powder of Ag particles coated with a metal or a metal oxide and PbO-B are used.
_{A 2} O ₃ —SiO ₂ -based glass frit and an organic vehicle (containing 5 to 10% by weight of ethyl cellulose, terpineol and a plasticizer) were kneaded with a three-roll to prepare a silver paste for printing. Then, this paste was patterned by a screen printing method and baked at 450 ° C. to 600 ° C. to form a silver electrode.

Sample No. Reference numeral 113 is a comparative example, which is an example using uncoated Ag particles. In Samples No. 91 to No. 113 shown in Tables 7 and 8, the cell size of the PDP, the dielectric layer, the protective layer, and the discharge gas were set in the same manner as in Example 1 above. (Experiment 3) The sample No. The a value and the b value were measured in the same manner as in Experiment 1 for the front panel plate 10 on the way of making PDPs 91 to 113. In addition, the above No.
With respect to the PDPs 91 to 113, the color temperature when the screen was displayed in all white was measured.

The results of this experiment are shown in Tables 7 and 8. (Discussion) Conventional sample No. In 113, the b value is +16.
No. 3, which is considerably yellowed, while the sample No. 3 of the example was used. In 91 to 112, the b value is −
The value is as low as 0.2 to 2.1, which shows that it is an excellent PDP with little yellowing.

Further, in the conventional PDP (No. 113), the color temperature value is 6300 ° K, whereas in the PDP of the embodiment, the color temperature is as high as 8950-9720 ° K. This is because the PDP of the example is the PD of the comparative example.
This shows that the color reproducibility is better than that of P and vivid display is possible. Regarding the glass forming the transparent dielectric layer, similar results were obtained even when Bi ₂ O ₃ based or ZnO based dielectric glass was used in addition to the above PbO based glass.

[Embodiment 4] The PDP of the present embodiment is
The overall structure is the same as that of the first embodiment, but a silver electrode formed of general Ag particles is used as the display electrode, and instead, when the front panel plate 10 is manufactured, first, the front glass is used. Metal ions existing near the surface of the substrate 11 (Ag
The display electrode 12 (silver electrode) is formed after the treatment for reducing the metal ions having a reducing action on the ions).

In a normal glass substrate, particularly in a glass substrate manufactured by the float method, metal ions having a reducing action on silver are present in the vicinity of the surface (in the range from the surface to a depth of 5 μm) as they are.
Here, “metal ion having a reducing action on silver” specifically means tin having a valence of less than 4, silicon having a valence of less than 4, aluminum having a valence of less than 3, aluminum having a valence of less than 1, sodium having a valence of less than 1, Potassium, magnesium less than 2
It refers to calcium less than valence, strontium less than valence 2, barium less than valence 2, zirconium less than valence 4, manganese less than valence 4, indium less than valence 4, iron less than valence 3, and the like.

However, as described above, if the silver electrode is formed after the treatment for reducing the metal ions having a reducing action on Ag ions, the reduction of Ag ions on the surface of the front glass substrate 11 is suppressed. Therefore, generation of Ag colloid is suppressed and yellowing is suppressed. Specific methods of the treatment for reducing the metal ions on the surface of the front glass substrate include (1) a method of etching the surface of the front glass substrate and (2) a method of baking the front glass substrate. Each will be described below.

(1) About Etching Method FIG. 10 is a diagram for explaining a step of performing a treatment for reducing metal ions on the surface of the front glass substrate 11 by etching and then forming the display electrode 12. First step: etching step For the front glass substrate 11,
An etching process is performed. In this etching process, the front glass substrate 11 is placed in an etching tank 101 that stores an etching solution (for example, hydrofluoric acid and sulfuric acid containing hydrofluoric acid and sulfuric acid).
After being dipped, it is washed by the washing device 102 and dried (FIG. 10A).

By this step, metal ions existing near the surface (metal ions having a reducing action on silver) are removed. The depth of the etching process is preferably 5 μm or more. This is because, as will be understood from an experiment described later, the yellowing suppression effect is remarkably exhibited when etching is performed to a depth of 5 μm or more.

On the other hand, the effect of suppressing yellowing does not change much even if the etching is further performed. Also, the time required for etching is
Although it depends on the concentration of hydrofluoric acid, it is almost proportional to the etching depth. Therefore, the smaller etching depth is advantageous in terms of mass productivity. From this point, the etching depth is 15 μm
The following is preferable. Note that the etching liquid may be one other than hydrofluoric sulfuric acid as long as it can etch the glass surface. For example, a fluoride such as calcium fluoride, sodium aluminum fluoride, or ammonium fluoride and sulfuric acid, hydrochloric acid, or the like. It is also possible to use hydrogen fluoride produced by combining acids.

Second Step: Polishing Step Since the etching in the above etching step causes nonuniformity (unevenness in etching) on the surface of the front glass substrate, in this step, the nonuniformity due to etching is caused by polishing the surface. To correct. Since this polishing is for removing the surface residue of the front glass substrate 11 and etching unevenness, polishing for a short time is sufficient. That is, since the polishing amount may be small, the thickness of the glass substrate does not become non-uniform due to this polishing.

This polishing is performed, for example, by using a belt type polishing machine as shown in FIG. The polishing machine is equipped with a polishing sheet 103 and a cylinder 104, and the polishing sheet 103 is pressed against the glass substrate 11 by the cylinder 104.

However, the polishing machine used may be one capable of physically polishing the glass surface, and for example, an Oscar type polishing machine may be used. In addition, this second step,
It is preferable, but not essential, to produce a highly uniform PDP by eliminating the etching unevenness generated in the etching step.

Next, (2) a processing method by baking the substrate will be described. First step: Deactivation step by firing: As shown in FIG.
The manufactured front glass substrate 11 is heated in the heating device 110 at a temperature of 500 ° C. or higher and then cooled. By this step, metal ions (metal ions having a reducing action on silver) existing near the surface of the glass substrate are oxidized and deactivated (the reducing action on silver is lost).

The front glass substrate 11 may be heated in normal air, but as shown in FIG.
If a gas supply pipe 111 and a gas exhaust pipe 112 are provided in the chamber and heating is performed while supplying an oxidizing gas (such as oxygen or air with an increased oxygen partial pressure) from the gas supply pipe 111, surface oxidation treatment can be performed in a shorter time. It can be carried out. Above (1)
Alternatively, the treatment method of (2) can reduce the concentration of metal ions on the surface of the glass substrate 11.

In the vicinity of the surface of the glass substrate (for example, a region from the surface to a depth of 5 μm), the concentration of the metal ion having a reducing property with respect to Ag ion is 1000 p.
It is considered that the reduction to pm or less is a standard for obtaining the yellowing suppression effect. This concentration is SIMS (seco
ndary-ionization mass spectroscopy).

After treating the surface of the front glass substrate 11 as described above, the electrode precursor 120 is formed (FIG. 10).
(C)). This electrode precursor is a silver powder mainly composed of silver,
It is formed by using an electrode paste containing a glass frit and an organic binder or a silver electrode film. Then, the silver electrode (display electrode 12) is formed by firing the electrode precursor 120.

(Explanation of Effects of the Present Embodiment) At the time of firing the silver electrode, A around the silver electrode of the front glass substrate 11
Although g ions diffuse, the growth of Ag colloids is suppressed because the concentration of metal ions that have a reducing property with respect to Ag ions is reduced. Therefore, the front glass substrate 11
Yellowing is suppressed.

Then, on the display electrode 12 (silver electrode), as described in the first embodiment, the transparent dielectric layer 1 is formed.
3. By forming the MgO protective layer 14, the front panel plate 10 with less yellowing can be manufactured. Therefore, by using this front panel plate 10, a PD showing good color temperature characteristics
P can be produced. (Experiment and Consideration on Degree of Substrate Surface Treatment) FIG.
(A) is experimental data showing the relationship between the etching depth of the glass substrate and the coloring chromaticity b when the silver electrode and the dielectric layer are formed, and is measured as follows.

A glass substrate (PD200 manufactured by Asahi Glass) was subjected to HF etching while changing the etching depth. A silver electrode was formed by printing an Ag paste on each of them by screen printing and firing. Furthermore, dielectric glass (# PLS-324
4) is applied and predetermined temperature (520 ℃, 545 ℃, 560 ℃
C., 593.degree. C.) to obtain a thickness of 23
A μm dielectric layer was formed.

Then, the coloring chromaticity b of each glass substrate was measured. From FIG. 12 (a), when the etching depth is 5 μm or more, the coloring chromaticity b shows a lower value than in the range of less than 5 μm, and in the range of 5 μm or more, the coloring chromaticity b
It turns out that does not change much. FIG. 12B shows 1
3 is experimental data showing the relationship between etching time and etching depth when a glass substrate is etched at 225.5 ° C. using a 0% HF aqueous solution.

From FIG. 12B, it is understood that the etching depth is almost proportional to the etching time. [Example 4]

[0127]

[Table 9]

Sample No. shown in Table 9 121-No. 12
The PDP No. 7 is an example in which the surface of the front glass substrate is etched and polished based on the present embodiment. As the front glass substrate, PD200 manufactured by Asahi Glass Co., Ltd. formed by the float method was used, and 5% hydrofluoric acid and 5% were used for etching.
Hydrofluoric acid mixed with% sulfuric acid was used. An Oscar type polishing machine using cerium oxide as a polishing material was used as the polishing device.

The display electrode is an organic vehicle containing Ag particles, ethyl cellulose, butyl carbitol acetate and terpineol as main components, and Bi ₂ O ₃ —B ₂ O ₃ —Si.
A glass frit containing O ₂ as a main component was kneaded to prepare a silver paste, which was printed and fired. Sample No. Reference numerals 128 to 131 are comparative examples, in which the front glass substrate is not or has not been sufficiently treated to reduce the concentration of metal ions having reducing properties for Ag ions.

The sample No. shown in Table 9 was used. 121-N
o. 131, PDP cell size and dielectric layer,
The protective layer and discharge gas were set in the same manner as in Example 1 above. (Experiment 4) The sample No. The a value and the b value of the front panel plate 10 on the way of producing PDPs 121 to 131 were measured in the same manner as in Experiment 1. Also, the above N
o. 121-No. For 131 PDPs, the color temperature was measured when the screen was displayed in all white.

The experimental results are shown in Table 9. In addition, No. of the example. Regarding Nos. 121 to No. 127, in the region of 5 μm from the surface of the front glass substrate, the concentration of tin less than tetravalent, manganese less than tetravalent, iron less than divalent, iron less than divalent, and indium less than divalent was reduced to 1000 ppm or less. (Discussion) Sample No. which is not surface treated. 129, sample No. 129 subjected only to mechanical polishing. In the case of 130, the b value is much higher than 10 and it can be seen that it has turned yellow considerably.

On the other hand, the sample No. of the example in which etching was performed for 5 μm or more and mechanical polishing was performed. 121-No. 1
In No. 25, the b value is as low as 0.5 to +3.8, which means that the PDP has little yellowing. In addition, a comparative example (Sample No. 12) that was fired at 400 ° C.
In Example 8), the b value is as high as 15.0, but in Examples (Sample Nos. 126 and 127) in which firing was performed at 500 ° C or higher,
The b value is as low as 2.5 to 3.8, which shows that it is an excellent PDP with little yellowing.

This indicates that it is preferable to heat at 500 ° C. or higher when the metal ions having a reducing action on silver are deactivated by heating the substrate. In addition, the sample No. of the comparative example. In 128-131,
While the color temperature value is 6900K or less, in the PDP of the embodiment, the color temperature is as high as 8900 to 9600K,
This shows that the panel has a vivid screen with good color reproducibility.

Sample N etched to a depth of 1 μm
o. In 131, the b value greatly exceeds 10. It is considered that this is because the etching depth is as small as 1 μm and the metal ion concentration near the surface is not reduced to 1000 ppm or less. Considering that the yellowing of the front panel plate greatly affects the image quality as compared with the yellowing of the rear panel plate (such as the modified example of the embodiment), the surface of the front glass substrate is the same as in the fourth embodiment. If yellowing is suppressed by treating
Although it has a sufficient effect of improving the image quality such as the color temperature of DP, it is considered to be more effective if the same treatment is applied to the surface of the rear glass substrate, because the yellowing of the rear panel plate can be suppressed.

When the surface treatment of the glass substrate described in the fourth embodiment and the silver electrode described in the first to third embodiments are applied in combination, a more remarkable yellowing suppressing effect can be expected. The simultaneous firing of the silver electrode precursor and the dielectric precursor layer has been described in the second embodiment.
3 can also be applied, and in that case, improvement of the yellowing suppression effect can be expected.

Similarly, in the above-described first to third embodiments, the example in which the silver electrode according to the present invention is used as both the display electrode and the address electrode is shown, but the present invention is applied only to the display electrode on the front panel side. If the silver electrode is applied, the image quality improving effect such as improving the color temperature of the PDP can be obtained. On the other hand, when the silver electrode of the present invention is applied only to the address electrodes, the yellowing suppression effect is inferior, but it is considered that some effect is achieved.

Further, in the above first to fourth embodiments,
Although the AC surface discharge type PDP in which the silver electrode is covered with the dielectric layer has been described as an example, the present invention is also applied to the DC type PDP in which the silver electrode exposed in the discharge space is formed on the glass substrate. By doing so, the effect of suppressing yellowing of the glass substrate is similarly exhibited. Further, it is not limited to a PDP using a silver electrode, and a fluorescent display tube or an E having a silver electrode arranged on a glass substrate.
Also in L and the like, yellowing of the glass substrate can be similarly suppressed by applying the present invention.

[0138]

As described above, according to the present invention, in a PDP using a silver electrode, a technique for suppressing yellowing of a panel is relatively easily provided, thereby providing an image with high brightness and high image quality. A displayable PDP can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing an AC surface discharge PDP according to an embodiment.

FIG. 2 is a partial cross-sectional view of an example of a front panel plate of the PDP.

FIG. 3 is a diagram illustrating a mechanism of yellowing of a panel.

FIG. 4 is a diagram illustrating a method of forming a silver electrode film made of a silver alloy by a sputtering method.

FIG. 5 is a diagram illustrating a method of forming a silver electrode film made of an Ag alloy by a thick film forming method.

FIG. 6 is a diagram illustrating a method of forming a silver electrode film made of an Ag alloy by a thick film forming method.

FIG. 7 is a diagram showing a configuration of a silver electrode formed by a thick film forming method.

FIG. 8 is a process diagram illustrating a simultaneous firing method for a silver electrode precursor and a dielectric precursor layer.

FIG. 9 is a diagram illustrating a silver electrode in which the surface of Ag particles is coated with a metal or a metal oxide.

FIG. 10 is a diagram illustrating a surface etching treatment step of a front glass substrate.

FIG. 11 is a diagram illustrating a deactivation process by firing a front glass substrate.

FIG. 12 is experimental data on the etching depth of a glass substrate.

[Explanation of symbols]

10 Front panel board 11 Front glass substrate 12a, 12b display electrodes 13 Transparent dielectric layer 14 Protective layer 20 Rear panel board 21 Rear glass substrate 22 Address electrode 23 White dielectric layer 30 bulkheads 31 phosphor layer 120 Silver electrode precursor 130 Dielectric precursor layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junichi Hibino             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Keisuke Sumita             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hideki Ashida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Shinya Fujiwara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hideki Marunaka             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Sei Nakagawa             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5C027 AA02 AA06                 5C040 FA01 FA04 GB03 GB14 GC18                       GC19 GD07 HA04 JA02 JA09                       JA12 JA15 JA21 JA22 KA09                       KA10 KB03 KB13 KB28 MA03                       MA05 MA30

Claims (12)

[Claims] 1. A first plate having a first electrode on its surface and a second plate having a second electrode on its surface with the first and second electrodes facing each other, A plasma display panel which is arranged with a gap and in which a gas medium is enclosed, wherein at least a first electrode of the first electrode and the second electrode is a transition layer of silver (Ag) and It has a silver electrode composed of a glass containing a metal oxide, and the transition metal oxide includes copper oxide (CuO), chromium oxide (Cr ₂ O ₃ ), nickel oxide (NiO), manganese oxide (Mn ₂ O). ₃ ), cobalt oxide (Co ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), and at least one selected from the plasma display panels. 2. The plasma display panel according to claim 1, wherein the transition metal oxide is contained in the glass in an amount of 5% by weight or more and 20% by weight or less. 3. The plasma display panel according to claim 1, wherein the glass is a lead oxide (PbO) type, a bismuth oxide (Bi ₂ O ₃ ) type or a zinc oxide (ZnO) type. 4. The plasma display panel according to claim 1, wherein the first electrode is formed by laminating the silver electrode on a transparent electrode film. 5. The plasma display panel according to claim 1, wherein the first electrode is covered with a dielectric layer made of a dielectric glass material. 6. A first plate having a first electrode on the surface thereof and a second plate having a second electrode on the surface thereof, wherein the first and second electrodes are opposed to each other, A plasma display panel which is disposed with a gap and in which a gas medium is enclosed, wherein at least the first electrode of the first electrode and the second electrode is silver (Ag) and a metal. And a silver electrode made of glass containing an oxide, wherein the metal oxide includes ruthenium oxide (RuO ₂ ), rhodium oxide (Rh
O), iridium oxide (IrO ₂ ), osmium oxide (OsO ₂ ), rhenium oxide (ReO ₂ ) and palladium oxide (PdO). 7. The plasma display panel according to claim 6, wherein the glass contains the metal oxide in an amount of 5% by weight or more and 20% by weight or less. 8. The glass comprises: PbO-B₂O₃-SiO₂System, Bi₂O₃-B₂O₃-Si
O₂System or P₂O_Five-B ₂O₃-SiO₂Special system
The plasma display panel according to claim 6, which is a characteristic. 9. The plasma display panel according to claim 6, wherein the first electrode is covered with a dielectric layer made of a dielectric glass material. 10. A first electrode disposing step of disposing a first electrode on a surface of a first plate, a second electrode disposing step of disposing a second electrode on a surface of a second plate, and a first plate. And a step of arranging the second plate with a gap in a state where the first electrode and the second electrode face each other and enclosing a gas medium in the gap, the method for manufacturing a plasma display panel. Of the first electrode disposing step and the second electrode disposing step, at least in the first electrode disposing step, after forming a film in which silver and glass frit containing a transition metal oxide are mixed, a film is formed. The patterned film,
A method of manufacturing a plasma display panel, comprising: a silver electrode forming step of forming a silver electrode by firing. 11. A first electrode disposing step of disposing a first electrode on a surface of a first plate, a second electrode disposing step of disposing a second electrode on a surface of a second plate, and a first plate. And a step of arranging the second plate with a gap in a state where the first electrode and the second electrode face each other, and arranging a gas medium in the gap, the method for manufacturing a plasma display panel. Of the first electrode disposing step and the second electrode disposing step, at least in the first electrode disposing step, silver, ruthenium oxide (RuO ₂ ), rhodium oxide (Rh)
O), iridium oxide (IrO ₂ ), osmium oxide (OsO ₂ ), rhenium oxide (ReO ₂ ) and a glass frit containing one or more metal oxides selected from palladium oxide (PdO). A method of manufacturing a plasma display panel, comprising: forming a silver electrode by patterning the formed film and baking the formed film after forming the silver electrode. 12. A silver electrode precursor forming step of forming a silver electrode precursor made of a material in which silver and glass frit are mixed on the surface of the first plate, and the silver electrode precursor on the surface of the first plate. A dielectric layer precursor forming step of forming a dielectric layer precursor made of a dielectric glass covering the first electrode and the dielectric layer by firing the silver electrode precursor and the dielectric layer precursor together. The forming step, the first plate, and the second plate on which the second electrode is disposed are arranged with a gap in a state where the first electrode and the second electrode are opposed to each other, and the gap is formed. And a disposing step of enclosing a gas medium therein.