JP2001093429A - Electrode structure for gas discharge display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease deterioration of a cathode caused by spatter, to improve deterioration of the cathode and inhomogeneous discharge caused by arc discharge, to realize a safe and low-voltage discharge on the whole area of a panel, and to provide a gas discharge display panel having a long span of life. SOLUTION: In a gas discharge display panel, anodes 11 and cathodes 12 which are exposed in a discharge space 10 are faced with each other and spaced away from each other by the discharge space 10. The anodes 11 and the cathodes 12 are sealed in an air-tight container together with a gas that can be ionized so as to make the gas discharge display panel. The cathode 12 is made of mixtures of at least conductive particles which are excellent in high secondary electron discharge and spatter-resistive characteristics, and insulation particles which are excellent in low secondary electron discharge and spatter- resistive characteristics. The cathode is formed of at least two layers, one is a coating electrode 14 which has such a mixing ratio of the mixtures that the number of the conductive particles decreases toward the discharge space 10 in a distribution in the direction of a film thickness of the cathode 12, while the other is a bas electrode 13 which is arranged on an inner layer of the cathode 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure of a gas discharge display panel of a DC drive type and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a DC-driven gas discharge display panel uses a conductive material such as Ni or Al as a cathode.
Recently, a cathode structure (Japanese Patent Application Laid-Open No. 7-230770) has been proposed in which the surface of a cathode base made of a conductive material is coated with a substance obtained by mixing LaB ₆ and BaAl ₂ O ₄ as an insulator.

FIGS. 3A and 3B are schematic views showing the structure of the conventional gas discharge display panel. This gas discharge display panel is a plasma addressed display device (Japanese Patent Laid-Open No. 1-21).
No. 7396) to which the electrode structure of JP-A-7-230770 is applied. This gas discharge display panel has a display cell 1 and a discharge cell 2 and a thickness 5 between them.
It has a flat panel structure in which a common thin glass 3 made of a glass sheet of 0 μm is laminated.

The display cell 1 has a front plate 4 made of transparent glass.
A front plate 4 in which a color filter and a signal electrode 7 (not shown) are sequentially laminated on one surface;
The thin glass 3 provided on one side of the front plate 4 is adhered at predetermined intervals via spacers 17, and the gap is filled with the liquid crystal layer 6. The signal electrode 7 is formed by disposing an ITO electrode material made of, for example, indium oxide / tin oxide, in a direction orthogonal to the partition walls 8 of the discharge cell, immediately above each dye row of the color filter, and substantially equivalent to each dye row (color filter). After being formed on the color filter by, for example, a vapor deposition method or a sputtering method so as to have the same dimensions, it is patterned by photolithography.

The discharge cells 2 are made of a back plate 5 made of transparent glass.
The anode 11 and the cathode 12 are formed on the back plate 5 so as to be exposed in the discharge space 10. The cathode 12 comprises a bus electrode 13 and a coating electrode 14, as shown in FIG. 3b. The bus electrode 13 and the anode 11 are made of Ag, and the coating electrode 14 is made of a mixture of LaB ₆ and BaAl ₂ O ₄ . The partition 8 is formed along the anode 11. Further, one surface of the front plate 4 and one surface of the back plate 5 face each other at the periphery, and the thin glass 3 is hermetically sealed using a back plate 5 having a plurality of partitions, anodes, and cathodes formed on one surface, and a sealing material 9. Joined.

On the other side of the front plate 4 and the back plate 5 opposite to the one surface, polarizing plates (not shown) orthogonal to each other are arranged.

As described above, in the gas discharge display panel, the back plate 5 and the front plate 4 are connected to each other via the thin glass 3, and a plurality of discharge spaces formed by the thin glass 3, the back plate 5, and the plurality of partition walls 8. It is manufactured by encapsulating an ionizable gas in 10. Here, for example, helium, neon, argon, xenon, and a mixed gas thereof are sealed as ionizable gas species.

In the above configuration, for example, the discharge space 1
When a predetermined voltage is applied between the anode 11 and the cathode 12 corresponding to 0, the anode 11 and the cathode 12 act as an anode and a cathode, respectively, and the gas in the portion of the discharge space 10 is selectively ionized and the plasma discharge is performed. Is generated, and the inside thereof is maintained at substantially the anode potential. When a data voltage is applied to the signal electrode 7 in this state, the data voltage is written to the liquid crystal layer 6 of the pixel corresponding to the discharge space 10 via the thin glass 3. When the plasma discharge ends, the discharge space 10 becomes a floating potential, and the voltage written to the liquid crystal layer 6 of the corresponding pixel is held until the next writing period (for example, after one frame). At this time, the discharge space 10 functions as a sampling switch, and the liquid crystal layer 6 of each pixel functions as a sampling capacitor. Since the liquid crystal operates with the data voltage written from the signal electrode 7 to the liquid crystal layer 6 of each pixel, display is performed in pixel units. Accordingly, a two-dimensional image can be displayed by sequentially scanning a pair of discharge spaces in which data voltages are written to the liquid crystal layers 6 of a plurality of pixels arranged in the column direction by generating a plasma discharge in the row direction. .

FIG. 4 is a schematic diagram showing the structure of the above-mentioned conventional gas discharge display panel. This gas discharge display panel is D
C-drive type plasma display panel (JP-A-8-3
No. 35439, hereinafter referred to as DC-PDP), in which Ag is used as a cathode material and Al is used as an outer layer.
2 shows an example of a layer structure. In this gas discharge display panel, a flat back plate 5 and a front plate 4 made of glass are disposed parallel to and opposed to each other, and the substrates 4 and 5 are separated at a predetermined interval by a partition wall 8 provided therebetween. Is held.
Further, a cathode 12 is provided on the back side of the front plate 4, and the cathode is a bus electrode 13 and a coating electrode 14.
It has a layered structure. An anode 11 is provided on the front side of the back plate 5 so as to be orthogonal to the cathode 12. Further, phosphors 18 corresponding to the respective emission colors are formed on the wall surfaces of the back plate 5 and the partition walls 8. Therefore, front panel 4
, A discharge space 10 surrounded by the back plate 5 and the partition 8, and an ionizable gas is sealed in the discharge space 10.
Further, for example, helium, neon, argon, xenon, and a mixed gas thereof are sealed as ionizable gas species.

In this DC-PDP, a discharge is performed by applying a predetermined voltage from a DC power supply (not shown) between a cathode and an anode. Then, the phosphor 18 is excited by ultraviolet rays generated by the discharge, and light having an emission color corresponding to the type of the phosphor is transmitted through the front plate 4 and emitted to the outside. As a result, a two-dimensional image is displayed on the front panel 4 as a display surface.

[0011]

DISCLOSURE OF THE INVENTION A discharge cell structure of a conventional DC-driven gas discharge display panel (JP-A-7-23077).
No. 0) has the following problems.

In Japanese Patent Application Laid-Open No. 7-230770,
LaB with excellent sputter resistance on the coated electrode₆And BaAl_TwoO_Four
An electrode structure using a material in which is mixed is disclosed. Departure
As a result of various studies based on the above invention, the
LaB in the electricity process₆Actively contributes to the discharge, and Ba
Al_TwoO_FourMake little contribution to the discharge
Was. That is, LaB₆Compared to coated electrode consisting only of
And LaB₆And BaAl _TwoO_FourUsing a material mixed with
The pole structure contributes to the discharge of the coated electrode surface exposed in the discharge space
Territory (LaB with excellent secondary electron emission)₆Occupancy) is narrow
Discharge current decreases, which is effective in suppressing cathode deterioration.
We have found something new.

However, in the above invention, as the mixing ratio of BaAl ₂ O ₄ as a dielectric is increased and the discharge current is limited, the chain of the conductive particles connecting the discharge space and the bus electrode is more likely to be broken, and the conduction path is secured. hard. As a result, a potential difference occurs inside the cathode film, and an arc discharge occurs. Particularly during the step of activating the cathode (initial aging), the deterioration of the cathode is promoted at the place where the arc discharge occurs. After initial aging, the discharge characteristics are different between the part of the cathode that has deteriorated due to the arc discharge at the time of initial aging and the part that has been properly initialized, so the uniformity of discharge is lacking and the entire coated electrode is normally activated. Deterioration of the cathode is faster.

Therefore, as shown in Japanese Patent Application Laid-Open No. 7-230770, even if the current is limited to reduce the sputtering energy and reduce the deterioration of the cathode,
The deterioration of the cathode due to the arc discharge is promoted, and it is difficult to greatly improve the panel life. Furthermore, uniformity of discharge is impaired, and it is difficult to obtain stable display quality.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a coated electrode made of a mixture of conductive particles and insulating particles by limiting a discharge current to a cathode formed by sputtering. A discharge layer that reduces the deterioration of
With a conductive layer that suppresses arc discharge and reduces cathode deterioration by securing electrical conduction between the discharge layer and the bus electrode, the discharge current is limited and the cathode deterioration is suppressed,
Provide a gas discharge display panel that secures a conductive path between a bus electrode and a discharge space, improves deterioration of a cathode due to arc discharge and non-uniformity of discharge, discharges the entire screen stably at a low voltage, and has a long life. The purpose is to:

[0016]

In a gas discharge display panel in which an anode and a cathode exposed in a discharge space are opposed to each other with a discharge interval therebetween and sealed with an ionizable gas in an airtight container, Is composed of a mixture of conductive particles having at least high secondary electron emission and excellent sputter resistance, and insulating particles having low secondary electron emission and excellent sputter resistance, and the mixing ratio of both mixtures in the thickness direction distribution of the cathode. It is composed of at least two layers of a coating electrode and a bus electrode in which the ratio of the conductive particles decreases toward the discharge space. In addition, 1
In one embodiment, part or all of the coated electrode is
And the mixing ratio of the conductive particles and the insulating particles in each layer is 20% or more and less than 50% of the total volume of both particles in the discharge layer. 50% of the volume of conductive particles is based on the total volume of both particles in the layer
More than and less than 100%. In one embodiment, the conductive particles and the insulating particles are the same material in the discharge layer and the conduction layer, respectively. In one embodiment, the chain of the conductive particles constituting the discharge layer has a thickness equivalent to 2 to 10 chains in the film thickness direction of the discharge layer. In one embodiment, the conductive particles are either hexaboride or tetraboride of the rare earth elements La, Gd, Y, Nd, Ce, and the insulating particles are BaAl ₂ O ₃ or Al ₂ O ₃ or La. _It consists of any of ₂ O ₃ . In one embodiment, the gas discharge display panel is a plasma addressed display having a liquid crystal layer.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas discharge display panel according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the dimensional ratio of each part in the drawings is not always accurate.

FIGS. 1A and 1B show a first embodiment in which the present invention is applied to a plasma addressed display device. A discharge cell of a discharge display panel according to the present invention and a method for forming the same will be described. Although the display cell 1 actually exists on the thin glass 3, the display cell 1 is omitted in FIG. 1A.

A method for forming the discharge cells 2 of the gas discharge display panel shown in FIG. 1A will be described. First, a photosensitive electrode paste containing Ag as a main component (DC206 manufactured by DuPont) is used on the back plate 5 that has been washed and annealed.
After printing one solid layer by the screen printing method, it is dried at 140 ° C. for 10 minutes in a belt type drying furnace. afterwards,
After patterning by exposure, development and drying under predetermined conditions, baking is performed to form the anode 11 and the bus electrode 13. In this embodiment, the bus electrode 13 has a width of 10 after firing.
0 μm, thickness 5 μm, anode 11 has a width of 400 μm, thickness 5
μm was obtained. Although Ag is used as the material, a conventional conductive material such as aluminum, nickel, and silver-palladium can also be used. The bus electrode 13
The anode 11 may be formed by forming a thin film by a vapor deposition method, a sputtering method, or the like, and then patterning by photoetching, a sand blast method, a pattern printing method by a screen printing method, or the like.

The coated electrode 14 has a discharge layer 15 for suppressing a discharge current by reducing an area contributing to discharge on the electrode surface exposed to the discharge space, and an electrical connection between the discharge layer 15 and the bus electrode 13 is ensured. And two conductive layers 16.

Both the discharge layer 15 and the conductive layer 16 are made of conductive particles having high secondary electron emission efficiency and excellent sputter resistance.
It is made of a mixed material of insulating particles having excellent low secondary electron emission efficiency and spatter resistance, and the mixing ratio differs depending on each layer.

In particular, as the discharge time elapses, the coated electrode 1
In order to prevent a rapid change in the discharge characteristics even when the discharge layer 15 is deteriorated and the conductive layer 16 is exposed, it is preferable to use the same kind and kind of conductive particles and insulating particles in the two layers. Is desirable. Here, the formation method by the sandblast method in which the formation of the coated electrode is easy was performed by the following method.

After forming the anode 11 and the bus electrode 13, one layer is printed by a screen printing method using the following paste for forming the coating electrode 14 (conductive layer 16), and the belt-type drying furnace is used. Hold at 140 ° C. for 10 minutes and dry.

Hereinafter, the paste composition when the coated electrode 14 (conductive layer 16) is formed by the sandblast method will be described. The paste is composed of a mixture of particles as a main component, an organic metal or a glass frit which becomes an insulating metal oxide by firing which functions as a binder, a solvent, and an organic additive of a resin.

As the particle component, a mixed material composed of conductive particles having high secondary electron emission efficiency and excellent spatter resistance and insulating particles having low secondary electron emission efficiency and excellent sputter resistance is used. The mixing ratio of the particles in the conductive layer 16 includes a large amount of conductive particles with respect to the insulating particles in order to improve the electrical conduction between the discharge layer 15 and the bus electrode 13, and specifically, with respect to the total volume of both particles. And the volume ratio of the conductive particles is 5
It is preferably 0% or more and less than 100%. More preferably, the ratio of the volume of the conductive particles to the total volume of both particles is 50% or more and 99% or less. More preferably, the ratio of the volume of the conductive particles to the total volume of both particles is 50% or more and 80% or less.

In this embodiment, a mixture of GdB ₆ as conductive particles and BaAl ₂ O ₄ as insulating particles at a volume ratio of 2: 1 is used.

The above-mentioned particles are not particularly limited as long as the conductive particles have at least high secondary electron emission efficiency and excellent spatter resistance. For example, in addition to GdB ₆ , LaB ₆ and YB ₄
Etc. may be used. Further, the insulating particles only need to have at least low secondary electron emission efficiency and spatter resistance.
In addition to Al ₂ O ₄ , Al ₂ O ₃ , La ₂ O ₃ or the like may be used.

The content of the mixture of the particles with respect to the paste may be within a range that functions as a cathode.

As the organic metal, an alkoxide or a carboxylate of an alkaline earth metal element, an alkali metal element, or a rare earth element can be selected. An insulating metal oxide formed by firing the organic metal is used as a binder. In addition to the function described above, it may also serve as a cathode.

The above glass frit is made of various glasses such as lead borosilicate glass or bismuth borosilicate glass containing borate and silicate as main components and containing at least one kind of lead, sulfur, selenium, bismuth and the like. Can be used. Incidentally, the particle size of these particles or glass frit,
Those having a size of several tens of microns to submicron can be suitably used.

Since the organic metal exists in a liquid state in the paste, the dispersibility of the particles is superior to that in which glass frit is mixed. The content of the above-mentioned organic metal and glass frit depends on the particle size of the particles. However, if the metal oxide formed from the glass frit or the organic metal through a heating step is 1% by weight or less with respect to the particle components, the content after firing is reduced. The adhesion between the particles or between the particles and the back plate is impaired,
If the content is 30% by weight or more, the conductivity is lowered and the characteristics as a cathode are impaired.

Further, the organic additives to be added to the above-mentioned paste include cellulose resin, urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester, alkyd resin, urethane resin, ebonite, polysiloxy silicate and the like. No. In order to maintain the fluidity and moldability of the mixture with the glass or the particles, the content of the organic additive must be such that the viscosity does not increase. It is desirable to have shape. From such a point, the content of the organic additive is desirably 0.5% by weight or more and 10% by weight or less based on the particle component.

The solvent to be added to the paste is not particularly limited as long as it is compatible with the organic additive. For example, α-terpineol, toluene, xylene, benzene, phthalate And higher alcohols such as hexanol, octanol, decanol and oxyalcohol, and esters such as diethylene glycol monobutyl ether acetate, acetate and glyceride. Furthermore, in order to volatilize the solvent slowly, it is also possible to use two or more of the above solvents in combination. The content of the solvent varies depending on the type and amount of the organic additive, but it is desirable to lower the viscosity to some extent in order to maintain printability.

As described above, in one embodiment, the composition of the above-mentioned paste is such that the mixing ratio of GdB ₆ and BaAl ₂ O ₄ as a component to the above-mentioned paste is 2: 1 by an average particle size. 42% by weight of 3 μm GdB ₆ powder, 18% by weight of BaAl ₂ O ₄ powder having an average particle size of 2 μm, and 6% of lead borosilicate glass having an average particle size of 2 μm as a glass frit.
%, Α-terpineol, diethylene glycol monobutyl ether acetate, each containing 14% by weight, and an ethylcellulose resin containing 6% by weight.

Further, in order to form the discharge layer 15 on the coated electrode 14, the following paste was used, and a single layer was printed by a screen printing method.
Hold at 0 ° C. for 10 minutes and dry.

The paste composition when forming the discharge layer 15 by sand blast will be described below. The past is
It is composed of a mixture of particles that are the main components, an organic metal or glass frit that becomes an insulating metal oxide by firing that functions as a binder, a solvent, and an organic additive of a resin.

As the particle component, a mixed material composed of conductive particles having high secondary electron emission efficiency and excellent spatter resistance and insulating particles having low secondary electron emission efficiency and excellent sputter resistance is used. The mixing ratio of the above particles is reduced by reducing the discharge current by narrowing the region contributing to the discharge (occupied by the conductive particles having excellent secondary electron emission efficiency) on the electrode surface exposed to the discharge space. More particles are contained in the conductive particles, and more specifically, the ratio of the volume of the conductive particles to the total volume of both particles is preferably 20% or more and less than 50%.

In this embodiment, a mixture of GdB ₆ as conductive particles and BaAl ₂ O ₄ as insulating particles at a volume ratio of 1: 2 is used.

The particles are not particularly limited as long as the conductive particles have at least high secondary electron emission efficiency and excellent spatter resistance. For example, in addition to GdB ₆ , LaB ₆ and YB ₄
Etc. may be used. Furthermore, the insulating particles only need to have at least a low secondary electron emission efficiency. For example, in addition to BaAl ₂ O ₄ ,
Al ₂ O ₃ , La ₂ O ₃ or the like may be used.

The content of the mixture of the particles with respect to the paste may be within a range that functions as a cathode.

As the organic metal, an alkoxide or a carboxylate of an alkaline earth metal element, an alkali metal element, or a rare earth element can be selected, and an insulating metal oxide produced by firing the organic metal is used as a binder. In addition to the function described above, it may also serve as a cathode.

The above glass frit is made of various glasses such as lead borosilicate glass or bismuth borosilicate glass containing borate and silicate as main components and containing at least one kind of lead, sulfur, selenium, bismuth and the like. Can be used. Incidentally, the particle size of these particles or glass frit,
Those having a size of several tens of microns to submicron can be suitably used.

Since the organic metal exists in a liquid state in the paste, the dispersibility of the particles is superior to that in which glass frit is mixed. The content of the organic metal and the glass frit depends on the particle size of the particles. However, if the metal oxide formed from the glass frit or the organic metal through a heating step is 1% by weight or less based on the particle components, the content after firing is reduced. The adhesion between the particles or between the particles and the back plate is impaired, and if it is 30% by weight or more, the conductivity is lowered and the characteristics as a cathode are impaired.

Further, the organic additives to be added to the above-mentioned paste include cellulose resin, urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester, alkyd resin, urethane resin, ebonite, polysiloxy silicate and the like. No. In order to maintain the fluidity and moldability of the mixture with the glass or the particles, the content of the organic additive must be such that the viscosity does not increase. It is desirable to have shape. From such a point, the content of the organic additive is desirably 0.5% by weight or more and 10% by weight or less based on the particle component.

The solvent to be added to the paste is not particularly limited as long as it is compatible with the organic additive. For example, α-terpineol, toluene, xylene, benzene, phthalate And higher alcohols such as hexanol, octanol, decanol and oxyalcohol, and esters such as diethylene glycol monobutyl ether acetate, acetate and glyceride. Furthermore, in order to volatilize the solvent slowly, it is also possible to use two or more of the above solvents in combination. The content of the solvent varies depending on the type and amount of the organic additive, but it is desirable to lower the viscosity to some extent in order to maintain printability.

As described above, in one embodiment, the composition of the above-mentioned paste is an average so that the mixing ratio of GdB ₆ and BaAl ₂ O ₄ as a particle component to the above-mentioned paste is 1: 2. 22% by weight of GdB ₆ powder having a particle diameter of 3 μm, 38% by weight of BaAl ₂ O ₄ powder having an average particle diameter of 2 μm,
6% by weight of lead borosilicate glass having an average particle size of 2 μm as a glass frit, 14% by weight each of α-terpineol and diethylene glycol monobutyl ether acetate,
A resin containing 6% by weight of an ethylcellulose resin is used.

Thereafter, after laminating, exposing, developing and sandblasting the dry film resist under predetermined conditions and patterning, the dry film resist is peeled off to form the coated electrode 14.

In this embodiment, the film thickness is 20 μm (discharge layer 10
μm, conductive layer 10 μm) and width 150 μm. Especially for the discharge layer 15, in order to secure a certain conduction path,
In this embodiment, it is desirable that the chain of the conductive particles constituting the film has a thickness of about 2 to 10, although it depends on the mixing ratio of the conductive particles and the insulating particles.

In the method of forming the coated electrode 14, the present embodiment does not require an expensive and complicated apparatus and can be formed by a simple process, but is formed by a sand blast method. It is not limited to
In addition to sandblasting, screen printing, vapor deposition,
A forming method such as an electrodeposition method, a sputtering method, and a thermal spraying method may be used. In this embodiment, the cathode 12 is composed of the bus electrode 13 and the coating electrode 14, but the anode 11 may have the same structure.

Next, the partition wall 8 is made of a thick film insulating paste containing low melting glass and a suitable filler (Okuno Pharmaceutical Co., Ltd. G3-21).
25), and after forming by screen printing method,
It is dried by holding at 140 ° C. for 10 minutes in a belt type drying furnace. In this embodiment, 11-layer printing is performed, and the film thickness is 200 μm.
I got The partition 8 may be formed by a sand blast method or the like.

Thereafter, the rear plate 5 is baked at a predetermined temperature in a range that does not cause thermal deformation, here 585 ° C., thereby forming the partition wall 8, the anode 11 and the cathode 12. However, the arrangement, the film thickness, and the dimensions of the anode 11, the cathode 12, and the partition 8 are not limited to these, and may be the same as the shape of a conventional discharge cell having various structures. Although the firing is performed simultaneously after forming the cathode 12, the anode 11, and the partition 8, which are the discharge cell components, the firing may be performed individually each time each discharge cell component is formed.

Thereafter, the thin glass 3 which has been washed and annealed is overlaid, and the periphery thereof is sealed with a sealing material 9 such as a low melting point glass.
And airtightly joined. Further, an ionizable gas is sealed in the discharge space 10 to complete the discharge cell 2. In this embodiment, xenon is used as the ionizable gas, but helium, neon, argon, krypton, or a mixed gas thereof may be filled. This discharge cell
Although it is a DC-driven plasma addressed display device, it is manufactured in the same manner as the prior art except for the cathode structure and manufacturing method for the discharge cell described above.

As a second embodiment, an example in which the present invention is applied to a DC-PDP will be described. A method for manufacturing the gas discharge display panel shown in FIGS. 2A and 2B will be described below. After the bus plate 13 is formed on the front plate 4 which has been washed and annealed, using an electrode paste containing Ag as a main component (NFP XFP5392) by a screen printing method.
It is dried by holding at 140 ° C. for 10 minutes in a belt type drying furnace. In this embodiment, two-layer printing was performed to obtain a width of 100 μm and a film thickness of 5 μm. As the other bus electrode material, for example, a conventional conductive material such as aluminum, nickel, silver, and silver-palladium can be used. The bus electrode 13 may be formed by forming a thin film by a vapor deposition method, a sputtering method, or the like, and then using a patterning method by photoetching or a forming method such as a sandblast method.

The covering electrode 14 has a discharge layer 15 that suppresses a discharge current by reducing an area contributing to discharge on the electrode surface exposed to the discharge space, and secures electrical continuity between the discharge layer 15 and the bus electrode 13. And two conductive layers 16.

Both the discharge layer 15 and the conduction layer 16 are made of conductive particles having high secondary electron emission efficiency and excellent spatter resistance.
It is made of a mixed material of insulating particles having excellent low secondary electron emission efficiency and spatter resistance, and the mixing ratio differs depending on each layer.

In particular, as the discharge time elapses, the discharge layer 15
When the conductive layer 16 is deteriorated and the conductive layer 16 is exposed, it is desirable to use the same type of conductive particles and insulating particles in each of the two layers in order to reduce a sudden change in the discharge characteristics. Here, the formation method by the screen printing method in which the formation of the coated electrode 14 is easy was performed by the following method.

After forming the bus electrode 13, the coated electrode 1
To form the conductive layer 16 of 4, the following paste is used to perform one-layer pattern printing by a screen printing method, and dried at 140 ° C. for 10 minutes in a belt-type drying furnace.
In this example, a film thickness of 10 μm and a width of 120 μm were obtained.

Hereinafter, a paste composition when the conductive layer 16 is formed by the screen printing method will be described. The paste is composed of a mixture of particles as a main component, an organic metal or a glass frit which becomes an insulating metal oxide by firing which functions as a binder, a solvent, and an organic additive of a resin.

As the particle component, a mixed material composed of conductive particles having high secondary electron emission efficiency and excellent spatter resistance and insulating particles having low secondary electron emission efficiency and excellent sputter resistance is used. The mixing ratio of the particles in the conductive layer 16 is such that the electrical contact between the discharge layer 15 and the bus electrode 13 is good, so that the conductive particles contain a large amount of conductive particles with respect to the insulating particles. Therefore, the volume of the conductive particles is preferably 50% or more and less than 100%. More preferably, the ratio of the volume of the conductive particles to the total volume of both particles is 50% or more and 99% or less. More preferably, the ratio of the volume of the conductive particles to the total volume of both particles is 50.
% Or more and 80% or less.

In this embodiment, La is used as the conductive particles.
B ₆ and insulating particles that are not mixed are used.

The metal particles are not particularly limited as long as the conductive particles have at least high secondary electron emission efficiency and excellent spatter resistance. For example, in addition to LaB ₆ , GdB ₆ , Y
B ₄ or the like may be used.

The content of the mixture of the particles with respect to the paste may be within a range that functions as a cathode.

As the organic metal, an alkoxide or a carboxylate of an alkaline earth metal element, an alkali metal element, or a rare earth element can be selected. An insulating metal oxide produced by firing the organic metal is used as a binder. In addition to the function described above, it may also serve as a cathode.

The above-mentioned glass frit is made of various glasses such as lead borosilicate glass or bismuth borosilicate glass containing borate and silicate as main components and containing at least one kind of lead, sulfur, selenium and bismuth. Can be used. Incidentally, the particle size of these particles or glass frit,
Those having a size of several tens of microns to submicron can be suitably used.

Since the organic metal is present in a liquid state in the paste, the dispersibility of the particles is superior to that in which glass frit is mixed. The content of the above-mentioned organic metal and glass frit depends on the particle size of the particles. However, if the metal oxide formed from the glass frit or the organic metal through a heating step is 1% by weight or less with respect to the particle components, the content after firing is reduced. The adhesion between the particles or between the particles and the back plate is impaired,
If the content is 30% by weight or more, the conductivity is lowered and the characteristics as a cathode are impaired.

Further, the organic additives to be added to the above-mentioned paste include cellulose resin, urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester, alkyd resin, urethane resin, ebonite, polysiloxy silicate and the like. No. In order to maintain the fluidity and moldability of the mixture with the glass or the particles, the content of the organic additive must be such that the viscosity does not increase. It is desirable to have shape. From such a point, the content of the organic additive is desirably 0.5% by weight or more and 10% by weight or less based on the particle component.

The solvent to be added to the paste is not particularly limited as long as it is compatible with the organic additive. For example, α-terpineol, toluene, xylene, benzene, phthalate And higher alcohols such as hexanol, octanol, decanol and oxyalcohol, and esters such as diethylene glycol monobutyl ether acetate, acetate and glyceride. Furthermore, in order to volatilize the solvent slowly, it is also possible to use two or more of the above solvents in combination. The content of the solvent varies depending on the type and amount of the organic additive, but it is desirable to lower the viscosity to some extent in order to maintain printability.

As described above, in one embodiment, the composition of the paste is 60% by weight of LaB ₆ powder having an average particle size of 3 μm as a particle component, and lead borosilicate glass having an average particle size of 2 μm as a glass frit. 6
%, Α-terpineol, diethylene glycol monobutyl ether acetate, each containing 14% by weight, and an ethylcellulose resin containing 6% by weight.

Further, in order to form the discharge layer 15 on the coated electrode 14, the following paste was used, and a one-layer pattern was printed by a screen printing method.
Hold at 40 ° C. for 10 minutes and dry. In this example, a film thickness of 20 μm and a width of 140 μm were obtained.

The paste composition when forming the covering electrode 14 (discharge layer 15) by screen printing will be described below. The paste is composed of a mixture of particles as a main component, an organic metal or glass frit which becomes an insulating metal oxide by baking functioning as a binder, a solvent, and an organic additive of a resin.

As the particle component, a mixed material composed of conductive particles having high secondary electron emission efficiency and excellent spatter resistance and insulating particles having low secondary electron emission efficiency and excellent sputter resistance is used. The mixing ratio of the above particles is reduced by reducing the discharge current by narrowing the region contributing to the discharge (occupied by the conductive particles having excellent secondary electron emission efficiency) on the electrode surface exposed to the discharge space. More particles are contained in the conductive particles, and specifically, the volume ratio of the conductive particles to the total volume of both particles is preferably 20% or more and less than 50%.

In this embodiment, a mixture of LaB ₆ as conductive particles and La ₂ O ₃ as insulating particles at a ratio of 1: 2 is used.

The particles are not particularly limited as long as the conductive particles have at least high secondary electron emission efficiency and excellent spatter resistance. For example, in addition to LaB ₆ , GdB ₆ , YB ₄
Etc. may be used. Furthermore, the insulating particles need only have at least a low secondary electron emission efficiency. For example, in addition to La ₂ O ₃ ,
₂ O ₃ , BaAl ₂ O ₄ or the like may be used.

[0074] The content of the mixture of the particles with respect to the paste may be within a range that functions as a cathode.

As the organic metal, an alkoxide or carboxylate of an alkaline earth metal element, an alkali metal element, or a rare earth element can be selected, and an insulating metal oxide produced by firing the organic metal is used as a binder. In addition to the function described above, it may also serve as a cathode.

The above-mentioned glass frit is made of various glasses such as lead borosilicate glass or bismuth borosilicate glass containing, as main components, borates and silicates and containing at least one of lead, sulfur, selenium, bismuth and the like. Can be used. Incidentally, the particle size of these particles or glass frit,
Those having a size of several tens of microns to submicron can be suitably used.

Since the organic metal is present in a liquid state in the paste, the dispersibility of the particles is superior to that in which glass frit is mixed. The content of the organic metal and the glass frit depends on the particle size of the particles. However, if the metal oxide formed from the glass frit or the organic metal through a heating step is 1% by weight or less based on the particle components, the content after firing is reduced. The adhesion between the particles or between the particles and the back plate is impaired, and if it is 30% by weight or more, the conductivity is lowered and the characteristics as a cathode are impaired.

Further, examples of the organic additives to be added to the above paste include cellulose resin, urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester, alkyd resin, urethane resin, ebonite, polysiloxane silicate and the like. Can be In order to maintain the fluidity and moldability of the mixture with the glass or the particles, the content of the organic additive must be such that the viscosity does not increase. It is desirable to have shape. From such a point, the content of the organic additive is 0.5% by weight with respect to the metal particle component.
The content is desirably at least 10% by weight.

The solvent added to the paste is not particularly limited as long as it is compatible with the organic additive. Examples of the solvent include α-terpineol, toluene, xylene, benzene / phthalate, and the like. And higher alcohols such as hexanol, octanol, decanol and oxyalcohol, or esters such as diethylene glycol monobutyl ether acetate, acetate and glyceride. Furthermore, in order to volatilize the solvent slowly, it is also possible to use two or more of the above solvents in combination. The content of the solvent varies depending on the type and amount of the organic additive, but it is desirable to lower the viscosity to some extent in order to maintain printability.

From the above, the composition of the above paste was LaB ₆ and La ₂ as a particle component with respect to the paste in a volume ratio.
20 wt% of LaB ₆ powder having an average particle size of 3 μm and La ₂ O _{3 having} an average particle size of 2 μm so that the mixing ratio of O ₃ becomes 1: 2.
40% by weight of powder, average particle size 2μ as glass frit
6% by weight of lead borosilicate glass, 14% by weight each of α-terpineol and diethylene glycol monobutyl ether acetate, and 6% by weight of ethyl cellulose resin
Use what it contains.

In this embodiment, the film thickness is 20 μm (discharge layer 10
μm, conductive layer 10 μm) and width 150 μm. Especially for the discharge layer 15, in order to secure a certain conduction path,
Although it depends on the mixing ratio of the conductive particles and the insulating particles, in this embodiment, it is desirable that the chain of the conductive particles constituting the film has a thickness of 2 to 10 or more.

In the method of forming the coated electrode 14, the present embodiment does not require an expensive and complicated apparatus and can be formed by a simple process. Therefore, the coated electrode 14 is formed by a screen printing method. It is not limited to this,
In addition to screen printing, sandblasting, vapor deposition,
Conventional forming methods such as an electrodeposition method, a sputtering method, and a thermal spraying method may be used. In this embodiment, the cathode 12 is used as the bus electrode 1.
3 and the coated electrode 14, the anode 11 may have a similar structure.

An anode 11 is formed on the back plate 5 which has been cleaned and annealed, in a direction perpendicular to the cathode 12 of the front plate 4. The anode 11 is made of an electrode paste containing Ag as a main component by a screen printing method (NFP XFP5392).
After forming using a belt-type drying furnace, 140 ° C.
Hold for 0 minutes and dry. In this embodiment, one-layer printing was performed to obtain a width of 100 μm and a film thickness of 10 μm. Other conductive materials such as aluminum, nickel, silver, and silver-palladium can be used as other anode materials.
The anode may be formed into a thin film by an evaporation method, a sputtering method, or the like, and then may be formed by a conventional forming method such as patterning by photoetching or sandblasting.

Next, the partition walls 8 are formed on the back plate 5 between the anodes 11 by screen printing using a thick film insulating paste (Okuno Pharmaceutical Co., Ltd. G3-2125) containing low melting point glass and a suitable filler. After forming, 14
Hold at 0 ° C. for 10 minutes and dry. In this embodiment, 10-layer printing was performed to obtain a width of 150 μm and a film thickness of 200 μm.
The partition 8 may be formed by a conventional method such as a sand blast method. Next, phosphors 18 corresponding to the respective display colors are applied to the side surfaces of the back plate 5 and the partition walls 8 by screen printing.

Then, the partition 8, the anode 11, and the cathode 12 are formed by firing at a predetermined temperature in a range where the front plate 4 and the rear plate 5 do not undergo thermal deformation, here 585 ° C. However, the arrangement, the film thickness, and the dimensions of the anode 11, the cathode 12, and the partition 8 are not limited to these, and may be the same as the shape of a conventional discharge cell having various structures. In addition, here, the firing is performed all at once after forming the cathode 12, the anode 11, the partition 8, and the phosphor 18, which are the discharge cell components, but the firing is performed individually each time each discharge cell component is formed. You may.

Then, the cathode 12 on the front plate 4 and the back plate 5
The front plate 4 and the back plate 5 are overlapped so that the upper anodes 11 face each other, and the periphery is hermetically bonded with a sealing material 9 such as low-melting glass. Further, an ionizable gas is sealed in the discharge space 10 to complete the gas discharge display panel in this embodiment. In this embodiment, Xe is used as an ionizable gas type.
However, helium, neon, argon, krypton, and a mixed gas thereof may be filled.

As a third embodiment, the covering electrode 14 (conduction layer 16 and discharge layer 15) in the first embodiment
This is an example in which an organic metal which becomes an insulating metal oxide by a heat process is applied to the binder constituting the above. The paste used when forming the coated electrode 14 is shown below.

The composition of the paste used to form the coated electrode 14 (conductive layer 16) is such that the mixing ratio of GdB ₆ and BaAl ₂ O ₄ as a particle component to the paste is 2: 1. 38% by weight of GdB ₆ powder having an average particle size of 3 μm and 22% of BaAl ₂ O ₄ powder having an average particle size of 2 μm.
%, 25% by weight of organic aluminum, 5% by weight of α-terpineol, 5% by weight of diethylene glycol monobutyl ether acetate, and 5% by weight of an ethylcellulose resin.

The composition of the paste used to form the coated electrode 14 (discharge layer 15) is such that the mixing ratio of GdB ₆ and BaAl ₂ O ₄ as a particle component to the paste is 1: 2. 22% by weight of GdB ₆ powder having an average particle size of 3 μm and 38% of BaAl ₂ O ₄ powder having an average particle size of 2 μm.
%, 25% by weight of organic aluminum, 5% by weight of α-terpineol, 5% by weight of diethylene glycol monobutyl ether acetate, and 5% by weight of an ethylcellulose resin.

The material, structure, forming method, etc., other than the paste composition used when forming the coated electrode 14 are the same as in the first embodiment, and will not be described here.

[0091]

According to the present invention, arc discharge is achieved by providing a coated electrode with a discharge layer which limits discharge current and reduces deterioration of the cathode due to sputtering, and ensures electrical conduction between the discharge layer and the bus electrode. A conductive layer having a high secondary electron emission efficiency and excellent sputter resistance constituting the discharge layer and the conductive layer; and a low secondary electron emission efficiency and sputter resistance. The ratio of the volume of the conductive particles to the total volume of both particles in the discharge layer is 20% or more and less than 50%, and the ratio of the conductive particles to the total volume of both particles in the conductive layer The following effects can be obtained by configuring the mixing ratio of 50% or more and less than 100% by volume.

The conduction path between the coated electrode surface (discharge layer) exposed in the discharge space and the bus electrode was improved, and arc discharge was reduced. In particular, arc discharge which occurs frequently during initial aging is significantly reduced, and initial aging is facilitated.

Therefore, local deterioration of the cathode due to arc discharge at the time of initial aging is suppressed, and the uniformity of discharge after initial aging is improved.

Further, since the surface of the electrode after the initial aging became uniform, the deterioration of the cathode with the passage of discharge time was reduced. As a result, the transmittance is prevented from deteriorating due to the attachment of the spattered substances, and the panel life is improved.

The discharge current is reduced by reducing the area contributing to the discharge (the occupation ratio of the conductive particles having excellent secondary electron emission efficiency) on the surface of the coated electrode exposed to the discharge space, thereby reducing the discharge current and increasing the discharge time. Cathode degradation was reduced. As a result, the transmittance is prevented from deteriorating due to the attachment of the spattered substances, and the panel life is improved.

By interposing a conductive layer having a composition similar to that of the discharge layer between the discharge layer and the bus electrode, the discharge layer deteriorates with the lapse of discharge time. Is similar to that of the discharge layer, so that the change over time in the discharge characteristics is small.

Therefore, when the discharge current is suppressed by increasing the dielectric ratio of the discharge layer, the thickness of the discharge layer is reduced by reducing the thickness of the discharge layer in order to reduce arc discharge due to the non-uniformity of the conduction path of the discharge layer. It is possible to secure.

As described above, according to the present invention, it is possible to provide a gas discharge display panel in which the entire screen is discharged stably at a low voltage and has a long life.

[Brief description of the drawings]

FIG. 1a is a schematic cross-sectional view for explaining a method of manufacturing a plasma addressed display device according to a first embodiment of the present invention.

FIG. 1b is a schematic sectional view showing a detailed structure of the coated electrode of FIG. 1a.

FIG. 2a is a schematic cross-sectional view for explaining a method of manufacturing a DC-driven plasma display panel according to a second embodiment of the present invention.

FIG. 2b is a schematic sectional view showing a detailed structure of the coated electrode of FIG. 2a.

FIG. 3a is a schematic sectional view showing a structure of a conventional plasma addressed display device.

FIG. 3b is a schematic sectional view showing a detailed structure of the coated electrode of FIG. 3a.

FIG. 4 is a schematic sectional view showing the structure of a conventional DC-driven plasma display panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Discharge space 11 Anode 12 Cathode 13 Bus electrode 14 Coated electrode 15 Coated electrode discharge layer 16 Coated electrode conduction layer

Continuing on the front page (72) Inventor Satoshi Hashimoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Hiroki Ishiji 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (72) Inventor Yoshihiko Minamiyama 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka F-term (reference) 5C040 FA02 FA09 GB08 GC03 GC05 GC18 KA02 KA04 KB03 KB17 KB19 KB28 MA10 MA17

Claims (6)

[Claims] 1. A gas discharge display panel comprising an anode and a cathode which are exposed in a discharge space and opposed to each other on a substrate with a discharge interval therebetween, and the anode and the cathode are sealed in an airtight container together with an ionizable gas. Wherein the cathode is at least two of a bus electrode provided on the substrate and a coating electrode provided on the discharge space side of the bus electrode.
The coated electrode contains conductive particles and insulating particles, and the ratio of the conductive particles contained in the coated electrode decreases toward the discharge space in the distribution of the coated electrode in the thickness direction. A gas discharge display panel comprising: 2. The conductive particles and the insulating particles, wherein a part or the whole of the covering electrode is composed of a discharge layer which is a layer near the discharge space and a conductive layer which is a layer near the bus electrode. Is less than or equal to 20% and less than 50% of the total volume of both particles in the discharge layer, and the conductive particles are more than 50% of the total volume of both particles in the conductive layer. The gas discharge display panel according to claim 1, wherein a volume of the gas discharge display panel is 50% or more and less than 100%. 3. The gas discharge display panel according to claim 2, wherein the conductive particles and the insulating particles are made of the same material in the discharge layer and the conductive layer, respectively. 4. In the discharge layer, a chain of the conductive particles constituting the discharge layer is 2 to 1 in a thickness direction of the discharge layer.
3. The gas discharge display panel according to claim 2, wherein the gas discharge display panel has a thickness equivalent to zero chains. 5. The method according to claim 1, wherein the conductive particles are rare earth elements La and G.
d, Y, Nd, Ce hexaboride or tetraboride, wherein the insulating particles are BaAl ₂ O ₃ , Al ₂ O ₃ or L
5. The semiconductor device according to claim 1, comprising a ₂ O _3.
A gas discharge display panel according to any one of the preceding claims. 6. The gas discharge display panel according to claim 1, wherein the gas discharge display panel is a plasma addressed display device having a liquid crystal layer.