JPH08115656A - Method for forming electrode on gas-discharge display panel - Google Patents

Abstract

PURPOSE: To enhance the accuracy of the effective size of resistance elements to which the bus bars and terminals of elements placed on the substrate of a resistance-equipped gas-discharge display panel are connected by providing electrodes which are positioned in a good relation and have good dimensional accuracy. CONSTITUTION: A conductive paste is thickly applied to the upper, front surface of a substrate 2 to form a conductive film 22, and after a layer of a photosensitive resin 23 is formed over the conductive film 22 the photosensitive resin 23 is exposed to light and developed via a light shielding mask 24 on which an electrode pattern is placed, and then the conducting film 22 is chemically etched with the patterned photosensitive resin 23 as a mask, and the patterned photosensitive resin 23 is peeled. High-definition electrode machining is made possible. Since the accuracy of the electrode machining is directly related to the effective size of resistance elements, variations in resistance value can be reduced.

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 electrodes arranged on two substrates constituting a gas discharge display panel.

[0002]

2. Description of the Related Art There are various types of gas discharge display panels, which are being developed with the aim of increasing their size, increasing their efficiency and increasing their definition. The most representative of these is 2
A panel of a system in which a cathode group and an anode group are respectively arranged on a sheet of transparent insulating substrate, these two substrates are sealed at a constant interval, and gas discharge is generated in the gap to emit light is provided. Are known. Furthermore, a panel in which a resistance element is installed in each discharge cell in order to control the discharge current has been proposed. As an example of this, Takano et al. “Pulse memory drive of discharge display panel with resistance” (1990, Television The annual conference, p 77-78).

FIG. 1 shows a schematic view of the structure of the gas discharge display panel shown in this document, (a) is a perspective view from the front of the panel, and (b) is a transverse sectional view of the panel.

This gas discharge display panel is composed of two substrates, a front plate 1 and a back plate 2. A cathode 3 installed on the front plate 1, an anode bus bar 4 and an auxiliary anode 5 installed on the back plate 2.
Are formed so as to be orthogonal to each other. Discharge cell 6
Is defined by a barrier 7, an anode terminal 8 is included in each discharge cell 6, and a cathode 3 crosses the vicinity of the center of each discharge cell 6. Further, the anode terminal 8 is electrically connected to the anode bus 4 via the resistance element 9. Then, when a predetermined voltage is applied between the cathode 3 and the anode bus bar 4, a current flows through the resistance element 9 to the anode terminal 8 to generate a discharge in the discharge cell 6, and the ultraviolet rays generated by this discharge are generated. The phosphors 10 of RGB three colors are adapted to emit light. This light emission is radiated to the outside through the front plate 1 to display a full-color image. In this case, the auxiliary anode 5 has a role of supplying charged particles serving as a pilot fire of discharge to the discharge cell 6 through the priming slit 11. Reference numeral 12 is a white back layer, which is intended to make color display clear. In this type of gas discharge display panel, the current is controlled by the function of the resistance element 9, so that there is an advantage that the current efficiency is improved and further the deterioration of the brightness due to the sputtering of the cathode 3 can be prevented and the panel life can be lengthened.

[0005]

By the way, in a large-sized gas discharge display panel, the components on the front plate and the back plate are formed by a thick film printing method typified by a screen printing method. The method has a drawback that the dimensions and thicknesses of the respective constituent elements vary depending on the manufacturing precision. In particular, in the display panel with resistance as described above,
The resistance value of each display cell greatly fluctuated due to inaccuracy in the positional relationship and size of the electrodes and the size and thickness of the resistance element. The variation in the resistance value directly leads to the variation in the discharge current of each discharge cell, that is, the variation in the light emission intensity, and there is a problem in that the brightness unevenness occurs on the display screen.

Therefore, an object of the present invention is to suppress the above-mentioned variation in resistance value. In particular,
(EN) A method for forming an electrode having good positional relationship and dimensional accuracy in order to improve the accuracy of the effective dimension (distance between an anode bus bar and an anode terminal) of a resistance element.

[0007]

In order to achieve the above-mentioned object, the present invention provides a front plate and a back plate on opposing plate surfaces such that a plurality of cathode groups and a plurality of anode groups are orthogonal to each other. The cathode group and / or the anode group, or one of them is composed of a bus bar and a terminal, and the bus bar and the terminal are electrically connected through a resistance element to the anode in the gas discharge display panel. A method of forming a group and / or a group of cathodes, comprising: (1) forming a conductive film on a substrate by applying a thick film of the conductive paste on the substrate and then drying and baking the conductive paste. First step (2) Second step of forming a photosensitive resin layer on the conductive film (3) After exposing the photosensitive resin layer through a light-shielding mask having an electrode pattern, The pattern of the photosensitive resin layer (4) Fourth step of chemically etching the conductive film using the patterned photosensitive resin as a mask (5) Each step of the fifth step of peeling the patterned photosensitive resin Is included at least.

[0008]

According to the electrode forming method of the present invention having the above-mentioned structure, the advantages of the electrode processing method in which the thick film and the photosensitive resin are combined are utilized to improve the dimensional accuracy, increase the area, and mass-produce. If possible, we will respond. Generally, the photosensitive resin is mainly used in a thin film process, and is suitable for high-precision processing on the order of submicrons. However, in the thin film formation by this, not only is the cost of the apparatus main body and its maintenance high, but it is also difficult to cope with a large area.
Therefore, in the present invention, the thin film forming step is performed by a thick film forming method suitable for mass production, and the pattern formation uses a photosensitive resin suitable for high-definition processing, thereby improving dimensional accuracy, increasing the area, and mass producing. It will be realized at the same time.

[0009]

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

FIG. 2 shows a constitutional example of a gas discharge display panel having electrodes formed according to the present invention.
Is a perspective view from the front surface of the panel, and (b) is a cross-sectional view of the panel.

As shown in the figure, the gas discharge display panel of this embodiment is composed of two substrates, a front plate 1 and a rear plate 2, on which a linear cathode 3 and a back plate are arranged. An anode bus bar 4, an anode terminal 8 and an auxiliary anode 5 are installed on the face plate 2. The anode bus bar 4 is composed of a linear anode 4a and an anode branch portion 4b extending from the linear anode 4a in the vertical and horizontal directions. The auxiliary anode 5 is located between two adjacent anode buses 4. The discharge cells 6 are defined by barriers 7, and each discharge cell 6
The anode terminal 8 is installed at the center of the. This anode terminal 8
And the anode branch portion 4b are electrically connected by a resistance element 9.

Comparing the panel of this embodiment having the above-mentioned structure with the panel described in the prior art, although the shapes of the anode bus bar 4, the anode terminal 8 and the resistance element 9 are different, the respective constituent elements are different from those in the prior art. Since the function of the panel is the same as that of the panel and the operation is the same as that of the panel, the description thereof will be omitted. A method of forming an electrode according to the present invention and a material used therefor will be described with reference to the process chart shown in FIG.

In FIG. 3, the substrate on which the electrodes are formed is the back plate 2. The back plate 2 may be a flat or curved surface and is chemically stable, and a glass substrate, a resin substrate, or the like may be used. In this embodiment, a glass substrate is used, and cleaning and annealing treatment is performed before use. did. Further, for the purpose of improving the printing quality, as shown in FIG. 3 (a), a glass substrate is coated with a glass paste as a base layer 21 by a screen printing method, dried, and then fired to form a back plate. Used as 2.

First, a conductive paste is thick-film printed on the entire surface of the back plate 2 by a screen printing method, and after the paste is dried, the paste is baked to form a conductive film 22 as shown in FIG. 3B. It was formed (note that the underlying layer 21 is omitted in FIG. 3B and subsequent figures). This conductive film 22
Is patterned by the etching process in a later step to become the anode bus bar 4, the anode terminal 8 and the auxiliary anode 5. As the material of the conductive paste, Au, Ag, P
In addition to metals such as d, Al, Ni and Cu or alloys thereof, conductive oxides such as ITO, which are paste-like conductors for thick film printing, and which can be chemically etched. Any of them may be used. In this example, Au and Ag were good.

In the case of Au as an example, after the Au printing paste for etching is thick-film printed by the screen printing method, 17
Dry at 0 ° C for 30 minutes, then at 580 ° C for 8 minutes A
By firing the u paste, the conductive film 22 having a thickness of about 1 μm could be formed. In some cases, the thick film printing and drying of the conductive paste may be repeated several times to increase the thickness of the conductive film 22. In this case, the film thickness increases in proportion to the number of prints.

When the conductive paste is Ag, one screen printing is performed, followed by drying at 170 ° C. for 30 minutes,
By baking the Ag paste at 580 ° C. for 8 minutes, the conductive film 22 having a thickness of about 5 μm could be formed.

Next, as shown in FIG. 3C, a liquid photosensitive resin 23 was applied onto the conductive film 22 and dried. As a coating method, spin coating, roll coating,
Any method may be used as long as it is a method for coating a liquid material such as blade coating, reverse coating, spraying or dipping. Further, the photosensitive resin 23 does not have to be liquid, and a film resist can be used. When a film resist is used, it may be directly attached onto the conductive film 22 using a laminator.

Then, as shown in FIG. 3D, the photosensitive resin 23 was exposed through a light-shielding mask 24 on which the patterns of the anode bus bar 4, the anode terminal 8 and the auxiliary anode 5 were arranged.
When the photosensitive resin 23 is a film resist,
After the exposure, heat treatment is performed at 70 to 90 ° C. for about 5 to 15 minutes,
The pattern resolution was better when the curing of the exposed area was promoted.

Next, as shown in FIG. 3E, pattern development of the layer of the photosensitive resin 23 is performed. Specifically, when the positive type is used as the photosensitive resin 23, the exposed part is chemically dissolved, and when the negative type is used, the unexposed part is chemically dissolved with a dedicated developer. The photosensitive resin 23 is pattern-developed. Then, after finishing the developing process, the photosensitive resin 23 is cured by heat treatment. As a result of this curing treatment, the adhesion between the conductive film 22 and the photosensitive resin 23 is increased, and it is possible to prevent the etching failure that occurs during the etching treatment in the subsequent process. This heat treatment is not always necessary depending on the photosensitive resin.

Subsequently, as shown in FIG. 3 (f), the conductive film 22 is formed by using the patterned photosensitive resin 23 as a mask.
Was chemically etched to simultaneously form the anode bus bar 4, the anode terminal 8 and the auxiliary anode 5. After finishing the etching process, cleaning and drying were performed.

Here, when a paste material containing Au as a main component is used as the conductive film 22, iodine, potassium iodide and water are mixed at a ratio of 1: 2: 5 (wt%), respectively. Was good. Conductive film 2
When the thickness of 2 is 2 μm, the etching treatment time is 90 to
A predetermined electrode pattern could be created in 150 seconds. further,
Alcohol, glycol, glycerin,
The use of a mixed solution containing at least one organic solvent selected from ethers, ketones and esters was the best. The addition of this organic solvent is characterized by suppressing the precipitation of iodine. That is, the iodine /
Iodine is likely to precipitate in an aqueous solution of potassium iodide, and when iodine is deposited on the conductive film 22, etching failure occurs at that portion, but since the solubility of iodine in the organic solvent is larger than that in water, the addition amount is Even if the volume ratio was 10% or less, the precipitation of iodine could be significantly suppressed.

When a paste material containing Ag as a main component is used as the conductive film 22, etching can be performed using either nitric acid or ferric nitrate aqueous solution having a concentration of 25% (wt%) or more. Was the first, especially with nitric acid
The electrode processing accuracy was the best when the second-stage etching was performed with an aqueous ferric nitrate solution after the first-stage etching treatment was performed for 1 minute or less. The reason for this is that
In the etching of the g paste, hydrogen gas is generated, the etching does not proceed in the portion where the generated gas adheres to the conductive film 22, and etching failure easily occurs. Further, in the ferric nitrate aqueous solution, gas is generated. This is because, although not accompanied, the surface stain remaining on the conductive film 22 acts as an etching mask and an etching defect is likely to occur.
Therefore, first, as a first step, the conductive film 22 is formed with nitric acid.
After cleaning the surface stains, the finest processing was possible when the second step was etching with an aqueous ferric nitrate solution.

After etching the conductive film 22, FIG.
As shown in (g), the photosensitive resin 23 was peeled off, and the substrate was washed and dried to form the anode bus bar 4, the anode terminal 8 and the auxiliary anode 5 which were processed into a predetermined pattern.

The following steps are the same as those in the prior art and will be briefly described. However, the resistive element 9, the white back layer 12 having an insulating property, the phosphor 10 are screen-printed, and the barrier 7 is a screen. It was formed by a printing method or a sandblast method. Further, a cathode 3 is formed on the front plate 1 by a screen printing method, and gas (Ne-Xe or He-Xe) is sealed together with the rear plate 2 manufactured in the above process to achieve the objective. A gas discharge display panel was produced.

The embodiment described above is a type in which the resistance element 9 is formed on the anode group side of the discharge cell 6, and the process for processing only the anode group of the back plate 2 by the forming method of the present invention has been described. The resistance element may be installed on the side of the cathode group, so that the anode group in the above description may be entirely replaced by the cathode group. Alternatively, it is possible to install resistance elements on both sides of the anode group and the cathode group, and in that case, both the cathode group and the anode group may be processed by the manufacturing method of the present invention. Further, a structure in which the anode group is on the front plate and the cathode group is on the back plate is also possible.

Further, the present invention is not limited to the gas discharge display panel having the structure shown in FIG. 2. For example, the colored light of the gas discharge using Ne-based gas as the discharge gas is used as it is without utilizing the phosphor emission. It can also be applied to a panel taken out to the outside.

Further, regarding the wiring pattern of the electrodes, not only the structure shown in FIG.
Or without the auxiliary anode 5 in three dimensions,
A structure in which the position, shape and size of the anode bus bar 4, the anode terminal 8 and the resistance element 9 are different is also applicable.

[0028]

Since the present invention is configured as described above, it has the following effects.

According to the prior art, it was very difficult to suppress the variation in the resistance value between the cells when installing the resistance element in each discharge cell of the gas discharge display panel. Since high-precision electrode processing becomes possible, manufacturing becomes easy, and since the accuracy of electrode processing is directly related to the effective dimension of the resistance element, it is possible to suppress variations in resistance value.

The conductive film is etched using the photosensitive resin as a mask to form an electrode pattern. As a result of careful investigation of the etching solution, for the Au conductive film, an aqueous solution of iodine / potassium iodide was added to an organic solvent. With the addition of, it became possible to process electrodes with high precision. Further, for the Ag conductive film, high-precision electrode processing became possible by two-step etching using two solutions of nitric acid and ferric nitrate aqueous solution.

Further, in the present invention, since the conductive film is formed by the thick film printing method, there is a remarkable advantage that it can correspond to a large area and mass production as compared with the case where a thin film process is applied. .

[Brief description of drawings]

FIG. 1 shows a schematic view of the structure of a conventional gas discharge display panel, FIG. 1 (a) is a perspective view from the front surface of the panel, and FIG. 1 (b) is a cross-sectional view of the panel.

2A and 2B show one configuration example of a gas discharge display panel manufactured according to the present invention, FIG. 2A is a perspective view from the front surface of the panel, and FIG. 2B is a transverse sectional view of the panel.

FIG. 3 is an explanatory view showing a manufacturing process of a panel according to the electrode forming method of the present invention.

[Explanation of symbols]

 1 Front Plate 2 Back Plate 3 Cathode 4 Anode Bus 5 Auxiliary Anode 6 Discharge Cell 7 Barrier 8 Anode Terminal 9 Resistive Element 10 Phosphor 11 Priming Slit 12 White Back Layer 21 Underlayer 22 Conductive Film 23 Photosensitive Resin 24 Light-shielding Mask

Claims (3)

[Claims] 1. A plurality of cathode groups and a plurality of anode groups are formed on opposite plate surfaces of a front plate and a back plate so as to be orthogonal to each other, and the cathode group and / or the anode group, or either one of them. Is a bus bar and a terminal, and the bus bar and the terminal are electrically connected via a resistance element, and a method for forming the above-mentioned anode group and / or cathode group in a gas discharge display panel of the type, (1) First step of applying a thick film of conductive paste on a substrate and then drying and baking the conductive paste to form a conductive film on the substrate (2) Photosensitive resin on the conductive film Step (3) of exposing the photosensitive resin layer through a light-shielding mask provided with an electrode pattern, and then performing pattern development of the photosensitive resin layer (4) patterning The photosensitive tree Fourth step of chemically etching the conductive film using the mask as a mask (5) Fifth step of peeling the patterned photosensitive resin Forming method. 2. A paste material containing Au as a main component is used as the conductive paste, and a mixed solution of iodine, potassium iodide and water is used as an etching solution for the conductive film.
Alternatively, a method of forming an electrode in a gas discharge panel according to claim 1, wherein a mixed solution obtained by adding at least one or more of alcohol, glycol, glycerin, ether, ketone and ester to the mixed solution is used. . 3. A paste material containing Ag as a main component is used as the conductive paste, and an aqueous solution of nitric acid or ferric nitrate having a weight ratio of 25% or more is used as an etching solution for the conductive film, or 2. The method of manufacturing a gas discharge panel according to claim 1, wherein the first stage etching is performed with the nitric acid, and then the second stage etching is performed with the iron nitrate aqueous solution.