JPH0785800A - Gas discharge display panel cathode and method for forming it - Google Patents

Abstract

PURPOSE:To prevent the damage to a cathode by spattering without using mercury in a DC type gas discharge display panel. CONSTITUTION:A cathode 10 is formed of a cathode body 12 and an insulating material 14 provided dispersively on the cathode body 12. The insulating material 14 is dispersed in island form in such a manner that the cathode body 12 is partially exposed in the plane view. The exposed area of the cathode body 12 is minimized, whereby discharge current is reduced. As the insulating material 14, an insulating material having a large secondary electron emitting coefficient, for example, MgO or Y2O3, is used, whereby the discharge starting voltage is reduced. Thus, by lowering the discharge current and discharge starting voltage, sputtering energy 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 cathode of a DC type gas discharge display panel and a method of manufacturing the same.

[0002]

Conventionally, the gas discharge display panel of various structures (PDP: P lasma D isplay P anel) have been proposed, the structure is classified roughly into a direct type and an AC type. In an AC PDP, a cathode and an anode coated with a dielectric are provided in the discharge space, whereas in a DC PDP, the exposed cathode and anode are provided in the discharge space.

Therefore, in the DC type, the cathode is sputtered by the gas discharge. PD by this spatter
Since the display quality of P is deteriorated and the life thereof is shortened, Hg is generally sealed in the discharge space to prevent sputtering of the cathode.

[0004]

However, encapsulating Hg may impair the health of the operator during the encapsulation work and may cause environmental pollution when the PDP is discarded.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cathode of a DC PDP capable of preventing spatter without enclosing Hg in the DC PDP, and a method of producing the same, in order to solve the above-mentioned conventional problems.

[0006]

In order to achieve this object, the cathode of the direct current PDP of the first invention is provided with a cathode body and a cathode body on which the cathode body is dispersed so as to partially expose the cathode body. It is characterized by comprising a plurality of island-shaped insulators.

The method for producing a cathode of a direct current type PDP of the second invention is one of the methods suitable for producing the cathode of the first invention, which comprises a step of forming an electrode body from an electrode material, and a step after or before the formation of the electrode body. And a step of forming a plurality of island-shaped insulators by cracking the deposited insulator by heating and cooling, and forming a plurality of island-shaped insulators on the electrode material. It is characterized by including.

The method for producing a cathode of a direct current type PDP of the third invention is one of the methods suitable for producing the cathode of the first invention, which comprises a step of forming an electrode body from an electrode material, and a step of forming or after forming the electrode body. A step of depositing a granular insulating material on the previous electrode material by plasma spraying to form a plurality of island-shaped insulating materials.

[0009]

According to the first aspect of the present invention, since the island-shaped insulator is provided in a dispersed manner and the cathode body is partially covered with the island-shaped insulator, the exposed area of the cathode body is reduced. As a result, the discharge current amount of the gas discharge is reduced, so that the sputtering energy can be reduced.

According to the second invention, the coefficient of thermal expansion of the insulator is different from the coefficient of thermal expansion of the electrode material. Therefore, if the electrode material and the insulator are heated and cooled while the insulator is deposited on the electrode material. , Cracks occur in the insulator. The crack can be divided into a plurality of island-shaped insulators by the gap A formed by the cracks or the insulators being partially peeled off during heating and cooling. Further, the electrode material can be exposed through the crack or the gap A.

According to the third aspect of the present invention, the granular insulating material is melted and sprayed and fixed onto the electrode material by plasma spraying, and the fixed insulating material forms the island-shaped insulating material. At this time, since the granular insulator can be fixed discretely, the electrode material can be partially covered with the island-shaped insulator, so that the exposed area of the electrode material can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the drawings are merely schematic representations so that the invention can be understood, and therefore the invention is not limited to the illustrated examples.

FIGS. 1A and 1B are a plan view and an end view conceptually showing the structure of the embodiment of the first invention. Figure 1
In (A), the cathode main body of the exposed portion when viewed in plan is shown in black, and in FIG. 1 (B), a cross section taken along line I-I in FIG. 1 (A). Shows the end face of.

The cathode 10 of this embodiment comprises a cathode body 12
And a plurality of island-shaped insulators 14 dispersedly provided on the cathode body 12 so as to partially expose the cathode body 12.

In this embodiment, the cathode body 12 is a ribbon-shaped or linear member. Preferably, the cathode body 12 is
It is formed of a conductive material, for example, 42-6 alloy, which has a thermal expansion coefficient almost equal to that of the substrate used for forming the DP.
The 42-6 alloy is an alloy consisting of 42 wt% Ni, 6 wt% Cr and 52 wt% Fe.

Further, the island-shaped insulator 14 is replaced with MgO or Y ₂ O ₃
The island-shaped insulator 14 is provided on the upper surface of the cathode body 12 and the side surfaces on both sides thereof over the entire length of the cathode body 12. Further, the island-shaped insulator 14 is provided on the cathode body 12 as a single layer. At this time, the island-shaped insulator 14 is dispersed so as to partially expose the cathode body 12 when viewed in plan.
By providing the island-shaped insulator 14, the exposed area of the cathode body 12 can be reduced.

Since the island-shaped insulator 14 is an insulator, if the exposed area of the cathode body 12 is made small when the PDP is constructed by using the cathode 10, the amount of discharge current flowing between the cathode and the anode of the PDP. Can be made smaller. If the amount of discharge current is reduced, the energy of sputtering due to gas discharge is reduced.

Therefore, the island-shaped insulator 14 may be an insulator, but in order to reduce the sputtering energy more effectively, the island-shaped insulator 14 should be an insulator having a high secondary electron emission coefficient. It is suitable. PD using cathode 10
2 is emitted from the island-shaped insulator 14 when P is formed.
The larger the amount of secondary electrons, the lower the discharge start voltage of gas discharge, and thus the sputtering energy decreases. Two
The higher the secondary electron emission coefficient is, the more secondary electrons are emitted.

Further, in order to continue the reduction of the sputtering energy by the island-shaped insulator 14, it is preferable to use an insulator having a sputtering resistance.

Therefore, the island-shaped insulator 14 is preferably an insulator having a high secondary electron emission coefficient, more preferably an insulator having a sputter resistance in addition to this. MgO and Y ₂ O ₃ have a high secondary electron emission coefficient and resistance to sputtering, and are therefore suitable as a material for forming the island-shaped insulator 14.

Next, a method of making the above-described embodiment of the first invention will be described as an embodiment of the second invention. This embodiment is an example in which cracks are generated in the insulating material deposited as a layer by heat treatment and the island-shaped insulating material 14 is formed from the individual insulating materials thus divided.

FIG. 2 and FIG. 3 are a plan view and an end view for explaining the production process of the embodiment of the second invention. FIG. 3 shows FIG.
The end face corresponding to (B) is shown.

First, the electrode body 12 is formed from the electrode material 16. Therefore, a conductive sheet-like member is prepared as the electrode material 16 (FIG. 2A). The sheet-shaped member is made of 42-6 alloy, for example. Then, by an etching technique or any other suitable technique, the electrode material 1
Process 6. By this processing, the electrode material 16 in which the plurality of electrode bodies 12 are integrated via the connecting portions 18 and 20
a is obtained (FIG. 2 (B)). In this electrode material 16a, a plurality of electrode bodies 12 are formed in a ribbon shape or a linear shape, respectively, and are arranged in parallel at a predetermined interval. Then, one end of the electrode body 12 or a portion in the vicinity thereof is connected to each other by the connecting portion 18, and the other end or a portion in the vicinity thereof is connected to each other by a connecting portion 20. Connecting part 18
It is also possible to connect the electrode bodies 12 to each other using only one of the electrodes 20 and 20.

Next, an insulator (island-shaped insulator forming material) 22 having a coefficient of thermal expansion different from that of the material is deposited on the electrode material 16a after the electrode body is formed. Therefore, the electrode material 16a
Is mounted on a fixing jig (not shown) and placed in the film forming chamber 24 of the film forming apparatus, for example, the electron beam evaporation apparatus (see FIG. 3).
(A)). Then, on the electrode body 12 of the electrode material 16a,
MgO or Y ₂ O ₃ is deposited as the insulator 22 (FIG. 3B). The insulator 22 is deposited on the upper surface and side surfaces of both sides of the cathode body 22 over the entire length of the cathode body 12.

Next, cracks are generated in the deposited insulator 22 by heating and cooling, and a plurality of island-shaped insulators 14 are formed.
To form. Therefore, the electrode material 16a is treated by the heat treatment device 2
Attach to 6. After that, the electrode material 16a is heated at 500 ° C. for 10 minutes while being kept in the atmosphere or an inert gas. Next, the electrode material 16a is cooled to room temperature. Due to the difference in thermal expansion between the insulator 22 and the cathode body 12, fine cracks are generated or the insulator 22 is partially peeled off due to the heating and cooling. The island-shaped insulator 14 is divided. As a result, a plurality of integrated cathodes 10 is completed. The cathode body 10 and the connecting portions 18 and 20 may be separated when the PDP is manufactured.

When viewed in plan, the display cell of the PDP is a rectangular area having a vertical width of 700 μm and a horizontal width of 700 μm, and the width of the cathode main body 12 is 100 μm, the area of the cathode main body 12 per display cell is It is 700 × 100 μm ² . In this case, the area per cell is 10
It is preferable to expose -50% and cover the rest with the island-shaped insulator 14. For example, the area where the cathode main body 12 is exposed can be adjusted by the deposition thickness of the insulator 22.

Next, a case of producing a PDP using the plurality of cathodes 10 integrated as described above will be described by way of an example. 4 to 5 are sectional views schematically showing the manufacturing process of the PDP. In these figures, display cell 1
The cross section of the region corresponding to the individual pieces is shown.

First, the anode 30 and an anode terminal (not shown) are formed on the back plate 28, for example, the substrate surface 28a of a glass substrate, by a thick film printing method (FIG. 4A). Here, the anode shape is a stripe shape extending in the X direction, and a plurality of anodes 30 are arranged in parallel.

The thick film paste for forming the anode is Electro Scienc
A Ni paste # 2554 manufactured by e Laboratries, which is screen-printed in a desired shape to form an anode pattern made of this paste. Then, the anode pattern is heated at 150 ° C. for 10 minutes to be dried. After that, the anode pattern is heated and baked at 580 ° C. for 10 minutes to complete the anode 30. An anode terminal is formed after or before forming the anode 30.

Next, a phosphor layer 32 is formed by a thick film printing method in a region corresponding to each display cell of the PDP (FIG. 4).
(B)). Here, the anode 30 in a region that should face the cathode
The phosphor layer 32 having a window 32a exposing the anode 30
Form on top.

A thick film paste for forming a phosphor layer is prepared by mixing phosphor particles and a resin vehicle. The mixing amount of these particles and the vehicle is adjusted to facilitate printing. Further, as the phosphor particles of the phosphor layer 32 that emits red, blue, and green fluorescence, red phosphor particles KX504A, blue phosphor particles KX501A, and green phosphor particles P1G1 manufactured by Kasei Optonix Inc. are used, respectively. As a resin vehicle, screen oil # 6009 manufactured by Okuno Pharmaceutical Co., Ltd. is used. After the paste is prepared, a red phosphor forming paste is screen-printed so as to have a predetermined shape, and a red phosphor pattern made of this paste is formed. Then, the red phosphor pattern is heated at 150 ° C. for 10 minutes to be dried. Similarly, blue and green phosphor patterns are formed and dried.

Next, the partition wall 34 is formed on the substrate surface 28a of the back plate 28 by the thick film printing method (FIG. 5A).
The partition wall 34 is for preventing erroneous discharge of the PDP. Here, the Y direction is defined as a direction intersecting with the X direction so as to be substantially orthogonal to the X direction, and the stripe-shaped partition walls 34 extend in the X direction and the Y direction. Then, the partition walls 34 in the X and Y directions are arranged between the display cells adjacent to each other in the X and Y directions. The partition wall 34 in the X direction is provided with a positioning portion 34a for the cathode, for example, a notch at the upper end thereof,
It is located between the adjacent anodes 30. The partition wall 3 in the Y direction
4 does not need to be formed.

The thick film paste for forming partition walls is made by Okuno Pharmaceutical Co., Ltd.
This is a dielectric paste ELD1380, and this paste is screen-printed in a desired shape to form a partition pattern made of this paste. After that, the partition pattern is 1
Heat at 50 ° C. for 10 minutes to dry. By repeating these printing and drying, a partition wall pattern having a stacking height of about 200 to 250 μm is formed. Next, the partition pattern and the phosphor pattern are heated and baked at 530 ° C. for 10 minutes to complete the partition 34 and the phosphor 32.

Next, the plurality of integrated cathodes 10 are divided into the partition walls 3
4 is attached to the positioning portion 34a. As a result, each cathode 10 is positioned at a position facing the anode 30 in the region corresponding to the window 32a, and the cathode 10 and the anode 30 are opposed to each other via the discharge space (FIG. 5 (B)). Since the positioning portion 34a is a notch here, the cathode 10 can be positioned by fitting it into the notch. After positioning, one and the other ends of the cathode 10 are fixed to the back plate 28, respectively, and then the connecting portions 18 and 20 of the electrode material 16a are cut off to separate the cathode body 10 individually. . Here, the end of the fixed cathode 10 is used as a cathode terminal, but the cathode terminal is formed on the back plate 28 before the partition wall is formed, and the individually separated cathode 10 is connected to the cathode terminal. Is also good.

Next, although not shown, a front plate, for example, a glass substrate is opposed to the rear plate 28 with the partition wall 34 interposed therebetween. Then, the front plate and the back plate 28 are sealed with an insulating sealing material. After that, discharge gas is filled between the front plate and the back plate 28 to complete the PDP.

FIGS. 6A and 6B are a plan view and an end view conceptually showing the structure of another embodiment of the first invention. In FIG. 6 (A), a portion of the cathode main body that is exposed when viewed two-dimensionally is shown in black, and in FIG. 6 (B), it is taken along the line I-I in FIG. 6 (A). The end face of the cross section is shown.

In this embodiment, the island-shaped insulator 14 is provided on the upper surface of the cathode body 12 over the entire length of the cathode body 12. The island-shaped insulator 14 is provided on the cathode body 12 so as to be laminated in a single layer or a plurality of layers. On this occasion,
A plurality of island-shaped insulators 14 are dispersed so as to partially expose the cathode main body 12 when seen in a plan view. Otherwise, the configuration is similar to that of the embodiment of FIG.

If the island-shaped insulator 14 can be laminated in a single layer or a plurality of layers to form a porous structure having a gap serving as a discharge current path between the adjacent island-shaped insulators 14. It is also possible to form or not to form a gap through which the cathode body 12 can be seen when seen in a plan view.

Next, a method of making another embodiment of the first invention described above as an embodiment of the third invention will be described. FIG. 7 is an end view used for explaining the producing process of the third embodiment of the invention, and shows the end face corresponding to FIG. 6 (B).

In this embodiment, first, similarly to the embodiment of the second invention, the sheet-shaped electrode material 16 is processed to form the electrode material 16a integrally formed with the plurality of cathode bodies 12 (see FIG. 2 ( A) to FIG. 2B).

Next, a plurality of island-shaped insulators 14 are formed by depositing a granular insulator 36 on the electrode material 16a after the electrode body is formed by plasma spraying. Therefore, the electrode material 16a is attached to a fixing jig (not shown) and attached to the plasma spraying device 38 (FIG. 7 (A)). Then, a granular insulator 36 is deposited on the electrode body 12 of the electrode material 16a by plasma spraying. The granular insulator 36 is deposited on the upper surface of the cathode body 12 over the entire length of the cathode body 12 to form the island-shaped insulator 14. As a result, a plurality of integrated cathodes 10 is completed (FIG. 7 (B)).

The particle shape of the granular insulator 36 may be spherical, columnar or any other shape, and the shape is not limited, but here, spherical MgO particles having a particle diameter of about 5 to ₂₀ μm or Y _{2 are used.}
The O ₃ particles are used as the granular insulator 36. According to the plasma spraying, the granular insulator 36 is fixed onto the cathode body 12 while melting at least the surface layer of the insulator 36 to form the island-shaped insulator 14. Therefore, the island-shaped insulator 14
The shape of is a shape obtained by deforming the particle shape of the insulator 36 before fixation, but in some cases is almost the same as the particle shape of the insulator 36 before fixation.

Further, according to the plasma spraying, the plurality of island-shaped insulators 1 are exposed so that the cathode body 12 is exposed in plan view.
4 can be formed in a dispersed manner, and thus a plurality of island-shaped insulators 14 can form an extremely porous structure. Cathode body 1 when viewed two-dimensionally after the island-shaped insulator 14 is formed
The exposed area of 2 is, for example, the size of the granular insulator 36 (this size is represented by, for example, the particle size) or the granular insulator 36.
Can be adjusted by the supply amount of the granular insulating material 36 per unit time in the case of depositing the particles, and the length of the period from the start to the end of the deposition of the granular insulating material 36.

The present invention is not limited to the above-mentioned embodiments, and therefore, the shape, size, arrangement position, arrangement number, forming material, process sequence, numerical condition and other conditions of each constituent are arbitrary. It can be changed appropriately. For example, it can be changed as described below.

(Regarding the first invention) The cathode of the first invention is
The invention is not limited to those created by the second and third inventions.

(Regarding the second invention) Heat treatment conditions for heating and cooling performed for generating cracks, for example, heating rate and temperature, cooling rate and temperature, heating time, and heat treatment atmosphere are within a range capable of generating cracks. It can be changed arbitrarily.

As a method of generating cracks, an insulator is deposited while heating the electrode material at a temperature suitable for generating cracks, for example, about 500 ° C., and thereafter,
The electrode material and the insulator may be cooled.

Further, the heating and cooling may be carried out not only once but also repeatedly plural times.

(Regarding the second and third inventions) It is better to handle a plurality of electrode bodies connected to each other, for example, when depositing an insulator on the electrode material or when positioning and fixing the insulator at a predetermined position of the PDP. It's easy. In particular, when positioning and fixing at a predetermined position of the PDP, it is convenient to make the arrangement interval P1 of the electrode bodies coincide with the arrangement interval P2 of the cathodes in the PDP because the positioning and fixing can be collectively performed. .

It is easier to form a PDP by forming a plurality of integrated cathodes and using them to make a PDP. However, the PDPs are individually separated from each other without being integrated. You may make it prepare a cathode.

[0051]

As is apparent from the above description, according to the cathode of the direct current type gas discharge display panel of the first invention, the exposed area of the cathode main body is reduced by providing the island-shaped insulator. The energy of the sputter can be reduced. Therefore, the panel life of the DC type gas discharge display panel can be extended without using mercury.

Further, according to the method for producing a cathode of a DC type gas discharge display panel of the second invention, after the insulator is deposited on the electrode material, the electrode material and the insulator are heated and cooled. A cathode of one invention can be made.

According to the method for producing a cathode of a DC type gas discharge display panel of the third invention, the first invention is a simple method of spraying and fixing the granular insulating material on the electrode material while melting it by plasma spraying. The cathode of can be created.

[Brief description of drawings]

1A and 1B are a plan view and an end view conceptually showing the structure of an embodiment of the first invention.

2A and 2B are plan views showing a manufacturing process of an embodiment of the first invention for explaining an embodiment of the second invention.

3 (A) to 3 (C) are end views showing a manufacturing process of an embodiment of the first invention for explaining an embodiment of the second invention.

FIGS. 4A and 4B are cross-sectional views showing an example of a method for producing a DC gas discharge display panel using the cathode of the first embodiment of the invention.

5A and 5B are cross-sectional views showing an example of a method for producing a direct current gas discharge display panel using the cathode of the first embodiment of the invention.

6A and 6B are a plan view and an end view conceptually showing the structure of another embodiment of the first invention.

7 (A) and 7 (B) are end views showing a manufacturing process of another embodiment of the first invention for explaining the embodiment of the third invention.

[Explanation of symbols]

 10: cathode 12: cathode main body 14: island-shaped insulator

(72) Inventor Hideo Sawai 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Ichiro Koiwa 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. In the company

Claims (6)

[Claims] 1. A cathode provided opposite to an anode in a discharge space of a DC type gas discharge display panel, wherein a cathode main body and a cathode main body are provided so as to be partially exposed on the cathode main body. A cathode of a gas discharge display panel, comprising a plurality of island-shaped insulators. 2. The cathode of a gas discharge display panel according to claim 1, wherein the island-shaped insulator is an insulator having a high secondary electron emission coefficient. 3. The cathode of a gas discharge display panel according to claim 1, wherein the island-shaped insulator is an insulator having spatter resistance. 4. A step of forming an electrode body from an electrode material in forming a cathode of the gas discharge display panel according to claim 1, and a thermal expansion of the material on the electrode material after or before the formation of the electrode body. A gas discharge display comprising: a step of depositing insulators having different coefficients; and a step of forming cracks in the deposited insulator by heating and cooling to form a plurality of island-shaped insulators. How to make a panel cathode. 5. A step of forming an electrode body from an electrode material in forming a cathode of the gas discharge display panel according to claim 1, and a step of forming a particle by plasma spraying on the electrode material after or before the formation of the electrode body. And a step of forming a plurality of island-shaped insulators by depositing the above-mentioned insulators, the method for producing a cathode of a gas discharge display panel. 6. The method for producing a cathode of a gas discharge display panel according to claim 4 or 5, wherein a plurality of electrode bodies are formed, the end portions of which are connected to each other and arranged in parallel at predetermined intervals, and the shape of each electrode body is formed. A method for producing a cathode for a gas discharge display panel, characterized in that the cathode is formed into a ribbon shape or a linear shape.