JP2002124146A - Forming method of electrode and plasma display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming method of an electrode which does not discolor the electrode to yellow, and to aim at a high picture quality of a plasma display. SOLUTION: A plasma display panel with high picture quality is obtained by simultaneously sintering an electrode 122 containing silver as a main component, and a dielectric substance 123 covering the electrode 122 which are formed on a substrate by the float method, while preventing a glass from discoloring to yellow caused by the silver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an electrode using a thick film material, and more particularly to a method for forming an electrode of a plasma display device used for a display device or the like.

[0002]

2. Description of the Related Art At present, there are many display panels using a thick film typified by a plasma display, a field emission display, an electroluminescence display, etc., some of which are commercially available, and some of which are under development. Among them, an AC type plasma display panel (hereinafter, referred to as “PDP”) is expected as a large-sized display which can realize a size of 40 inches or more.

This PDP has a front panel 116 and a rear panel 106 as shown in FIG.
Is formed by forming a display electrode 103 and a black stripe 114 on a front glass substrate 102 and covering the display electrode 103 with a dielectric glass layer 104 and a dielectric protection layer 105 made of magnesium oxide (MgO). .

[0004] The rear panel 106 is formed by providing an address electrode 108, a partition 110, and a phosphor layer 111 on a rear glass substrate 107. Then, such a front panel 116 and a rear panel 106
Are bonded by a peripheral sealing material (not shown),
The discharge space 112 is formed by filling the discharge gas into the space partitioned by the partition 110 through the exhaust pipe 113.
For color display, the phosphor layer is usually red, green,
Three colors of blue are arranged in order.

[0005] In the discharge space 112, a discharge gas obtained by mixing, for example, neon and xenon is usually 65 kPa.
(500 Torr).

The discharge gas irradiates ultraviolet rays by discharge with a periodic voltage usually applied to an address electrode, a display electrode, etc., and the ultraviolet light is converted into visible light by a fluorescent material to display an image.

As the PDP glass substrate, the float method is frequently used because its size can be relatively easily increased. In the float method, a glass material melted in a melting furnace is poured onto tin melted at a high temperature, and cooled to obtain a flat plate.

Further, thick-film silver is frequently used for the address electrode and the display electrode. Examples of the method for producing an electrode using this thick film silver include a method using a silver paste containing silver, a resin and a solvent as in a screen printing method, and a method using a film containing silver and a resin as a dry film method. There is. In any case, it is necessary to perform a baking treatment in the step of removing the resin and the like.

[0009]

In the baking step of silver, silver is contained in a substrate glass prepared by a float method or
It diffuses into the dielectric in the form of silver ions. Then, the diffused silver ions are reduced to tin ions or the like in the substrate glass (in the float glass), and colloidal silver particles are deposited.
Since this silver colloid has a property of absorbing light in the vicinity of 400 nm, there is a problem that coloring of the glass occurs and the image quality of the panel is remarkably deteriorated (for example, JE.
SHELBY and J.M. VITKO. Jr Jo
urnalof Non Crystalline S
oids Vol50 (1982) 107-11
7).

[0010] Such a phenomenon is not a phenomenon peculiar to the glass produced by the float method, but generally occurs also on the glass surface containing a reducing substance other than tin.

A first object of the present invention is to provide a method for forming an electrode which can reduce the coloring of a substrate which occurs when silver is used for an electrode, even on glass containing such a reducing substance.

A second object of the present invention is to provide a plasma display panel having electrodes formed by the above method, and
An object of the present invention is to provide a plasma display panel display device including the plasma display panel.

[0013]

According to the present invention, in order to attain the first object, a substrate containing a reducing substance is provided.
An electrode precursor forming step of forming an electrode precursor containing at least silver, a dielectric precursor forming step of coating and forming at least a part of the electrode with a dielectric precursor containing a low-melting glass, and an electrode precursor And a baking step of baking the dielectric precursor at the same time.

In order to achieve the first object, the present invention provides an electrode precursor forming step of forming an electrode precursor containing at least silver and a resin on a substrate containing a reducing substance; A resin decomposition step in the electrode precursor, a dielectric precursor formation step of forming at least a part of the electrode by coating with a dielectric precursor containing a low-melting glass, and simultaneously firing the electrode precursor and the dielectric precursor The present invention provides an electrode forming method characterized by including a firing step.

Further, in order to achieve the first object, the present invention provides an electrode precursor forming step of forming an electrode precursor containing at least silver on a substrate containing a reducing substance; A coating layer forming step, a dielectric precursor forming step of coating and forming at least a part of the electrode with a dielectric precursor containing low-melting glass, and a firing step of simultaneously firing the electrode precursor and the dielectric precursor. The present invention provides a method for forming an electrode, comprising:

According to a second aspect of the present invention, there is provided a plasma display panel manufactured by the above-described electrode forming method, and the plasma display panel is provided. It is intended to provide a plasma display device.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a process chart for explaining an embodiment of the electrode forming method of the present invention.

(First Step-Electrode Precursor Forming Step) An electrode precursor 120 is formed on the front glass substrate 102 manufactured by the float method. As the electrode precursor, an electrode paste containing silver powder and an organic binder as an essential component of an organic solvent, or an electrode film obtained by processing the above essential components into a film is used. As the organic binder, a cellulose compound such as ethyl cellulose, an acrylic polymer such as methyl methacrylate, and the like are preferable, but not limited thereto.

As a forming method, a paste obtained by adding a solvent to the above essential components is applied by using a screen printing method, a die coating method, or the like. As a method of processing into an electrode shape, a pattern necessary for a screen used at the time of screen printing may be formed, or after coating in a solid shape, patterning may be performed by a photo method (FIG. 1).
(A)).

(Second Step-Dielectric Precursor Forming Step) The electrode precursor 120 processed in the pattern shape in the above is
Coated with dielectric precursor 102. At this time, as a dielectric precursor to be used, glass and an organic binder are essential components, and a dielectric paste to which a solvent is added,
It is performed by applying and drying using a screen printing method or a die coating method. Also, this is performed by sticking a dielectric film obtained by processing the above essential components into a film by a laminating method (FIG. 1).
(B)).

(Third Step-Resin Decomposition Step)
Temperature to the temperature at which the resin contained in the electrode protection layer decomposes,
More preferably, the resin in the electrode protective layer is completely decomposed by lowering the temperature raising rate or stopping the temperature raising above the resin decomposition start temperature. In this step, if necessary, supply oxidizing gas such as oxygen for the purpose of performing more complete oxidation, reducing gas such as hydrogen for the purpose of preventing the oxidation of metals, and dry air for the purpose of assisting the oxidation at a lower cost. And
The heating atmosphere may be depressurized for the purpose of quickly removing the generated gas out of the system (FIG. 1C).

(Fourth Step-Firing Step) After the heat treatment step, the temperature is further raised to soften and fire the glass component contained in the electrode precursor 120 and the glass component contained in the dielectric precursor 102. . That is, it is left for several minutes to several tens of minutes at a temperature equal to or higher than the softening point. By this operation, the electrode precursor changes to the electrode 122, and the dielectric precursor changes to the dielectric 123.

After completion of the firing step, the temperature is lowered to complete the electrode forming step (FIG. 1D).

As described above, the simultaneous firing of the electrode precursor and the dielectric precursor has the following effects. Conventionally, at the time of firing the electrode precursor, the diffusion of silver ions has occurred only on the glass substrate because the dielectric precursor is not coated. Since a reducing substance such as tin is present on the glass substrate, reduction of silver ions to silver occurs as described above, and thus coloring by silver colloid occurs. On the other hand, according to the present invention, the silver ions are diffused not only in the glass substrate but also in the dielectric precursor because the coating with the dielectric precursor has already been performed at the time of firing the precursor. In the dielectric precursor, the reduction of silver ions to silver is significantly reduced compared to the case without the dielectric precursor coating because there are fewer reducing substances compared to on the glass substrate. . Thus, the yellowing of silver is mitigated.

[0026]

【Example】

[0027]

[Table 1]

Sample No. shown in Table 1 1 to No. Twelve PDPs have electrodes and dielectrics formed based on the above embodiment.

As an electrode, an organic vehicle containing ethyl cellulose, butyl carbitol acetate and terpineol as main components, and a glass frit containing Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ as a main component are kneaded at a predetermined weight ratio. Then, a stripe-shaped electrode pattern having a width of 100 μm is formed by a screen printing method.

As the dielectric, PbO—B ₂ O ₃ —SiO
_A glass paste for a dielectric mainly composed of _2- CaO-based glass is coated with the above-mentioned electrode pattern by a printing method to form a paste of about 3%.
It is formed with a thickness of 0 μm.

According to the conditions shown in Table 1, the electrode and the dielectric were heated and fired to obtain a front plate, thereby completing a PDP. The cell size of the PDP is 0.15 m, and the height of the partition wall 110 is 0.15 m in accordance with the display for 42 inch VGA.
m, the interval (cell pitch) between the partition walls 110 is set to 0.36 mm, and the distance d between the discharge electrodes 114 is 0.10 mm.
Set to.

As for the method of forming the MgO protective layer 105, the protective layer was formed by a sputtering method.

(Experiment) Sample N prepared as described above
o. For the PDPs 1 to 12, the degree of coloring of the glass is shown using a color difference meter (Nippon Denshoku Industries Co., Ltd., part number NF777) for the glass substrate, particularly including the dielectric layer on the electrode that is important for the image quality of the panel. * Value, b * value (JIS Z
8730 color difference display method). As the a * value increases in the + direction, red increases, the green increases in the − direction, yellow increases as the b * value increases in the + direction, and blue increases as the b * value increases in the − direction. a * value is -5 to +5
If the b * value is in the range of -5 to +5, the coloring (yellowing) of the glass substrate is hardly visible. Especially b * value is 1
Above 0, yellowing becomes noticeable. The color temperature when the panel screen is completely white is measured using a multi-channel spectrometer (Otsuka Electronics Co., Ltd.
(CPD-7000).

Sample No. According to the measurement results of the a * value and the b * value of the panels 1 to 15 (front glass substrate) and the measurement results of the color temperature of the panel (Table 1), the conventional panel (sample N
o. 13 to 15) have a b * value (degree of yellowing) of 10
Whereas the present application has a b * value of 0.1.
The value is as low as 5 to +8.5 (there is almost no yellowing), indicating that the panel is an excellent panel with little discoloration. The color temperature of the conventional panel is 7100K or less, whereas the color temperature of the panel of the present invention is 8900 to
9600K indicates that the panel has a high color temperature, good color reproducibility, and a bright screen.

The heating after the formation of the electrode is not always necessary for suppressing yellowing, but it is more preferable to perform the heating in order to completely remove the solvent or the resin remaining in the electrode precursor. However, when the heating temperature is increased, yellowing occurs depending on the heating temperature. Sample No. From the results of the panels 10 to 12, the temperature is preferably 380 ° C or lower.

[0036]

As described above, according to the electrode forming method of the present invention, yellowing and discoloration can be suppressed in the electrode provided with the electrode and the dielectric glass layer covering the electrode. Furthermore, according to the plasma display device of the present invention,
A panel with a high color temperature can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a method for forming an electrode according to an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of a conventional AC type plasma display panel.

[Explanation of symbols]

 Reference Signs List 120 electrode precursor 102 dielectric precursor 122 electrode 123 dielectric

Continued on the front page (72) Inventor Keisuke Sumita 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 5C027 AA01 AA05 5C040 FA01 FA04 GC18 GC19 GD07 GD09 JA02 JA12 JA13 JA22 KA01 KA08 KA14 KB11 KB17 KB19 LA17 MA10 MA23 5G323 AA03

Claims (15)

[Claims] An electrode precursor forming step of forming an electrode precursor containing at least silver on a substrate containing a reducing substance, and at least a part of the electrode by a dielectric precursor containing a low melting point glass. And a firing step of firing the electrode precursor and the dielectric precursor at the same time. 2. An electrode precursor forming step of forming an electrode precursor containing at least silver and a resin on a substrate containing a reducing substance; a resin decomposing step in the electrode precursor; An electrode forming method, comprising: a dielectric precursor forming step of forming at least a part of the electrode with a contained dielectric precursor; and a firing step of simultaneously firing the electrode precursor and the dielectric precursor. 3. The electrode forming method according to claim 2, wherein the resin decomposition step is performed by heating. 4. The method according to claim 3, wherein the heating temperature is 380 ° C. or less. 5. An electrode precursor forming step of forming at least a silver-containing electrode precursor on a substrate containing a reducing substance, a coating layer forming step of coating the electrode, and a low-melting glass. An electrode forming method, comprising: a dielectric precursor forming step of forming at least a part of the electrode with a dielectric precursor; and a firing step of simultaneously firing the electrode precursor and the dielectric precursor. 6. The method according to claim 3, wherein the coating layer is a layer that blocks oxygen. 7. The electrode forming method according to claim 1, wherein the substrate is a glass substrate. 8. The electrode forming method according to claim 1, wherein a firing temperature in the electrode firing step is lower than a firing temperature in the dielectric firing step. 9. The electrode forming method according to claim 1, wherein said substrate is a front cover plate. 10. The method according to claim 1, wherein the reducing substance is tin or tin ions. 11. The method according to claim 8, wherein the glass substrate is formed by a float method. 12. The firing temperature in the electrode firing step is 560.
The method for forming an electrode according to any one of claims 1 to 11, wherein the temperature is lower than or equal to ° C. 13. The electrode forming method according to claim 1, wherein a temperature difference between the softening point of the low melting point glass and the temperature of the electrode forming step is 90 ° C. or less. 14. A plasma display panel manufactured by the electrode forming method according to any one of claims 1 to 13. 15. A plasma display device comprising the plasma display panel manufactured according to claim 14.