JPH1165481A - Formation of dielectric layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for formation of a dielectric layer capable of forming the dielectric layer which is smooth in surface without generating gaps and dents which are the cause for generation of bubbles by using a dielectric thin-film sheet (green sheet). SOLUTION: In the method for formation of the dielectric layer by forming the dielectric layer 17 so as cover electrodes on a substrate disposed with the electrodes, a liquid or semiliquid dielectric material is adhered onto the substrate disposed with the electrodes and a dielectric thin-film sheet 14 is disposed in lamination on the liquid or semiliquid dielectric material and this laminated liquid or semiliquid dielectric material is solidified and is integrated to the dielectric thin-film sheet 14.

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 a dielectric layer on a substrate in a display device or the like, and more particularly to a method for forming a dielectric layer on a substrate using a dielectric thin film sheet. It relates to a forming method.

[0002]

2. Description of the Related Art Among display devices, a plasma display (PDP) is one that satisfies the requirements for large screen display and large display capacity. This PDP is based on whether the display discharge for displaying the screen is DC (direct current) or AC (alternating current).
Type and AC type. This AC type PD
P provides a pair of display electrodes constituting a discharge cell on at least one of the front and back glass substrates, covers the electrodes with a dielectric layer, and insulates the display electrodes from the discharge space with the dielectric layer. It has a memory function of accumulating wall charges generated by the plasma discharge of the discharge cells.

As a conventional method for forming a dielectric layer on a glass substrate, there are a method of forming the dielectric layer by a screen printing technique and a method of forming a thick film by a thick film coating apparatus called a slot coater. Recently, a dry film method in which a dielectric thin film sheet is attached and formed has been proposed as a new method. In the method using the screen printing technology and the thick film coating device,
In each case, a thick film is formed by printing or applying a glass paste obtained by forming a low contact glass powder into a paste on a glass substrate, and the thick film is fired at a high temperature such as 600 ° C. for a long time to form a dielectric layer. Is formed.

In the case of the electrode substrate on the display surface side, as shown in FIG.
And a bus electrode 12 laminated on a glass substrate 10 to form a display electrode (FIGS. 1A and 1B), and a green sheet in which glass powder is formed into a sheet on the glass substrate 10 on which the electrode is formed. A thin film glass sheet (hereinafter, referred to as a glass sheet) 14 is laminated (FIG. 3C), and the glass sheet 14 is fired at a high temperature such as 600 ° C. for a long time to form a dielectric layer 17. ((D) in the figure). By this long-time firing, the glass sheet 14 is formed.
When melted and solidified in the same manner as the above-mentioned glass paste, the dielectric layer 17 becomes a solid glass body. A protective layer 15 made of MgO is formed on the dielectric layer 17 (FIG. 3E).

[0005]

Since the conventional method for forming a dielectric layer is constituted as described above, when a screen printing technique is used, a thick glass paste film can be simply formed. There is a problem that the thickness of the glass paste to be a layer becomes non-uniform (for example, an uneven surface of 7 to 8 μm), and the surface of the dielectric layer cannot be formed smoothly. Further, when a thick film coating apparatus is used, 1/10 or less of screen printing (for example, 1
It is possible to form a smooth dielectric layer having a roughness of about μm), but the coating operation must be performed by precisely adjusting the thick film coating apparatus, and the coating operation of the glass paste 13 cannot be simplified. Have issues.

In the case of using the dry film method, when a glass sheet 14 is laminated on a glass substrate 10 on which electrodes are provided, a gap is formed near a step at an end of the electrode, and air in the gap is formed. Will remain as bubbles after the glass sheet 14 is melted and solidified to form a dielectric layer. Bubbles in this dielectric layer are
When the glass substrate 10 is a front end substrate, there is a problem in that the transmittance of the discharge light generated in the discharge cells is attenuated to lower the display brightness.

Particularly, as shown in FIG. 7, the bus electrode 12 is made of chromium 12a-copper 12b-chrome 12c (Cr-C
u-Cr) is formed in a three-layer structure. In the process of forming the bus electrode 12 having the three-layer structure, the intermediate copper 12b is etched more than the chromium 12a and 12c, thereby forming a concave groove-shaped depression 12d. In the electrode structure having a concave groove-shaped depression 12d on the side like the bus electrode 12, when the glass sheet 14 is laminated and fired at a high temperature and melted, the glass of the glass sheet is not covered with the concave groove. Bubbles are not filled in the hollows 12d and bubbles are generated. Bubbles generated in the concave grooves 12d of the bus electrode 12 are:
When the glass sheet is fired, it is connected to other bubbles generated in the molten glass to form a through hole communicating with the glass surface, and hot air in a combustion furnace (not shown) melts the copper 12b of the bus electrode 12 through the through hole to break the wire. There is a problem of letting them be killed. After completion of the sealing and assembling of the front and rear substrates (10, 20), the discharge space of the discharge space is gradually inserted into the recessed groove 12d of the bus electrode 12 through the pinhole in the dielectric layer. There is a problem that the discharge gas for display flows into the discharge cell and the discharge gas amount in the discharge cell becomes equal to or less than a specified amount, so that the discharge becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a dielectric layer having a smooth surface without using a dielectric thin film sheet (green sheet) to generate gaps or depressions which cause bubbles. It is an object of the present invention to provide a method for forming a dielectric layer that can form a dielectric layer.

[0009]

According to the present invention, there is provided a method for forming a dielectric layer, wherein an electrode is provided on a substrate, and the dielectric layer is formed so as to overlap the electrode. A liquid or semi-liquid dielectric material is adhered to a substrate on which electrodes are disposed, and a dielectric thin film sheet is disposed by laminating on the liquid or semi-liquid dielectric material. The liquid or semi-liquid dielectric material thus obtained is solidified and integrated with a dielectric thin film sheet.

As described above, according to the present invention, a liquid or semi-liquid dielectric material is interposed between a substrate on which electrodes are disposed and a dielectric thin film sheet laminated on the substrate. However, since the liquid or semi-liquid dielectric material fills the level difference at the end of the electrode and flattens it, the dielectric can be easily formed without generating gaps (bubbles) between the substrate and the dielectric thin film sheet. A body layer can be formed. In particular, when a dielectric layer is formed on a glass substrate of a PDP, since bubbles are not present in the dielectric layer, light generated in the discharge cells is transmitted without attenuating and display is performed with high luminance. Can be performed. Further, since the electrodes provided on the substrate are not oxidized, disconnection of the electrodes can be prevented.

Further, the method for forming a dielectric layer according to the present invention comprises the steps of:
It is desirable to deposit a liquid or semi-liquid dielectric material on the substrate by screen printing. According to this screen printing method, a dielectric material can be simply and quickly attached onto a substrate.

Further, in the dielectric layer forming method according to the present invention, it is desirable that the liquid or semi-liquid dielectric material and the dielectric thin film sheet are formed of the same material or the same refractive index material. By using the same material or a material having the same refractive index as described above, when the substrate is used on the display side, refraction or irregular reflection in the dielectric layer is eliminated, and display light is not reduced and display brightness is improved. Can be done.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment of the Present Invention) An example in which the dielectric layer forming method according to the first embodiment of the present invention is applied to an AC type PDP will be described below with reference to FIGS. FIGS. 1 and 2 are schematic explanatory diagrams of manufacturing steps of a method of forming a dielectric layer according to the present embodiment, and FIGS. 3 and 4 are operation flowcharts of the method of forming a dielectric layer shown in FIGS. .

In each of the drawings, the AC type PDP according to the present embodiment has a display electrode (address electrode 21) composed of a transparent electrode 11 and a bus electrode 12 disposed on a front glass substrate 10 (back glass substrate 20). 1 (A), 1 (B), 2
(A)), the front glass substrate 10 (the rear glass substrate 2).
0) A glass paste 13 (23) in which a glass powder was formed into a paste form was printed thereon by a screen printing method (FIG. 1).
(C), FIG. 2 (B)) and the glass paste 13 (2
3) Dielectric glass sheet (green sheet) 14
(24) are stacked and arranged (FIG. 1 (D), FIG.
(C)), the glass paste 13 (23) and the glass sheet 14 (24) are baked, solidified and integrated to form a dielectric layer 17 (27) (FIGS. 1E and 2D). Thereafter, on the front glass substrate 10, a protective layer 15 made of magnesium oxide (MgO) or the like is formed by vapor deposition on the dielectric layer 17, and on the rear glass substrate 20, the dielectric layer 27 is formed.
A partition wall 25 for partitioning a discharge portion made of a dielectric material on the top
And a phosphor layer 26 is formed in a groove between the partition walls 25 (FIGS. 2E and 2F).

The glass sheet 14 is made of silicon dioxide
(SiO_Two) And boron trioxide (B_TwoO _Three) As the main component
Borosilicate glass or soda lime glass
It can also be constituted by a film-like body. This glass
The plate 14 is mainly made of borosilicate glass or soda lime glass.
If it is composed of a film-like material
The strike 13 is a powder of borosilicate glass or soda lime glass
Is desirably composed of a paste-like semi-liquid. Ma
The glass paste 13 is mainly composed of lead oxide (PbO).
Formed as a paste from low melting glass powder as a component
You can also. In this case, the glass sheet 14
Also uses low-melting glass containing lead oxide (PbO) as the main component.
It is desirable to form it in the shape of a triangle.

The transparent electrode 11 has transparency and conductivity.
For example, indium oxide (In) _TwoO_Three) And tin oxide
(SnO_Two) Semiconductor ITO (Ingium Tin Oxide)
Is done. Bus electrode 1 provided on transparent electrode 11
2 is, for example, chromium / copper / chromium (Cr / Cu / Cr)
And a metal electrode having a three-layer structure.

Next, a description will be given of a process of manufacturing a PDP substrate structure including the method of forming a dielectric layer according to the present embodiment based on the above configuration. First, a thin film of the transparent electrode 11 is formed on the front glass substrate 10 by a sputtering method, and is patterned by lithography (step 1).
A bus electrode 12 having a three-layer structure of chromium, copper, and chromium is formed at an end in the longitudinal direction on the transparent electrode 11 by a sputtering method and a lithography technique (step 2).

A glass paste 13 is formed on the front glass substrate 10 including the display electrodes including the transparent electrodes 11 and the bus electrodes 12 so as to fill the display electrodes by a screen printing technique (step 3). By this step, a step formed at the ends of the transparent electrode 11 and the bus electrode 12 protruding from the front glass substrate 10 and a concave groove 12d in the Cu layer of the bus electrode 12
Is filled with a glass paste to prevent the occurrence of bubbles.

The glass sheet 14 is disposed on the thick film of the glass paste 13 (step 4). By firing the thick film of the glass sheet 14 and the glass paste 13 at a predetermined high temperature in a firing furnace, the glass paste 13 and the glass sheet 14 are integrated to form the dielectric layer 1.
7 is formed (step 5).

In this step, the thick film of the glass paste 13 having a non-uniform film thickness and an uneven surface is smoothed by a glass sheet 14 formed in advance as a uniform and smooth sheet body, which is then fired. Thus, the dielectric layer 17 having a smooth surface can be formed.

On the dielectric layer 17, for example, a thin film of magnesium oxide (MgO) is formed as a protective layer 15 by a vapor deposition method (step 6). Through the above steps, the PDP substrate structure on the front side is completed.

Next, after or in parallel with the processing on front glass substrate 10, processing on rear glass substrate 20 is performed. An address electrode 21 of Cr-Cu-Cr is formed on the rear glass substrate 20 by a sputtering method and a lithography technique (step 11). A thick film of a glass paste 23 is formed on the rear glass substrate 20 on which the address electrodes 21 are formed by a screen printing technique (step 12).

A glass sheet 24 is laminated on the thick film of the glass paste 23 (step 13), and the thick film of the glass paste 23 and the glass sheet 24 are fired at a predetermined high temperature in a firing furnace to form a dielectric layer. 27 are formed (step 14). This dielectric layer 27 is formed on the front glass substrate 10.
As in the case of the dielectric layer 17, no gap (bubble) is generated at the end of the protrudingly disposed address electrode 21.
In addition, a film having a uniform thickness and a smooth surface is formed.

On this dielectric layer 27, a thick film of a dielectric substance is formed by a thick film technique called a slot coater method, and this thick film is cut into a partition pattern by sandblasting to form partition walls (ribs) 25. (Step 15). This partition 25 is screen-printed in addition to sandblasting,
It can also be formed using a known technique such as a dry film method or a photosensitive barrier material method. A phosphor layer 26 is applied and formed in the groove between the partitions 25 (step 16).
The phosphor layer 26 is formed on the partition 2 by screen printing technology.
5 and the surface of the attraction layer, and may be formed by sandblasting.

Thus, the PDP substrate structure on the rear side is completed.

The processed front glass substrate 10 and rear glass substrate 20 are assembled and integrated as shown in FIG. 2G (step 7), and the integrated front glass substrate 10 and rear glass substrate 20 are integrated. Is sealed (step 8), the gas in the space between the sealed front glass substrate 10 and the back glass substrate 20 is exhausted, and a discharge gas is sealed in this space to complete the PDP (step 9).
In the PDP thus manufactured, the dielectric layer 17 is formed without bubbles in the front glass substrate 10,
In addition, since the surface is formed as a smooth surface, it is possible to display with high luminance without attenuating the color light generated in the discharge cells. In addition, each of the front and rear glass substrates 1
Since the dielectric layers 17 and 27 of 0 and 20 are formed without including bubbles between the respective electrodes, no dielectric breakdown occurs and no disconnection of the electrodes occurs.

(Other Embodiments of the Invention) In the above embodiment, the display electrodes (address electrodes 21) are arranged on the front (back) glass substrate 10 (20) so as to protrude. A concave portion 10a (20a) is provided in the front (back) glass substrate 10 (20) (shown in FIG. 5A), and a bus electrode 12 of a display electrode is provided in the concave portion 10a (20a).
A configuration in which the (address electrode 21) is embedded (FIGS. 5B to 5E) may be employed. By forming the bus electrodes 12 (address electrodes 21) without protruding above the front (rear) glass substrate 10 (20), display electrodes (addresses) as shown in FIGS. The dielectric layer 17 (27) can be formed without generating gaps (bubbles) between the dielectric glass sheet 14 (24) laminated on the electrode 21).

In the above-described embodiment, the glass paste 13 (23) and the glass sheet 14 (24) are formed of the same material. However, after being integrated by firing, different refractive indices become the same or similar. It can also be composed of materials.

In the above embodiment, the AC type PDP
Has been described, but the present invention can also be applied to the formation of a white dielectric layer (white back) disposed on the back substrate of a DC PDP for the purpose of reflecting discharge light. In addition, display devices other than PDP, for example, EL (Electro Lumi)
nescence) and the like.

[0030]

As described above, according to the present invention, a liquid or semi-liquid dielectric material is placed between a substrate on which electrodes are provided and a dielectric thin film sheet laminated on the substrate. The dielectric material is solidified and integrated with the dielectric thin film sheet, so that gaps (bubbles) are not generated at the ends of the electrodes on the substrate, and the dielectric has a uniform and smooth surface. A body layer can be formed. In particular, when a dielectric layer is formed on a glass substrate of a PDP, since bubbles are not present in the dielectric layer, light generated in the discharge cells is transmitted without attenuating and display is performed with high luminance. And a dielectric layer having a uniform and smooth surface can generate uniform discharge in all discharge cells. Further, since the electrode formed of copper or the like provided on the substrate of the PDP is not oxidized by the oxygen of the bubbles, there is an effect that disconnection of the electrode can be prevented.

In the present invention, the liquid or semi-liquid dielectric material is deposited on the substrate by the screen printing method, so that the dielectric material can be deposited on the substrate simply and quickly. This has the effect that the dielectric layer can be formed uniformly and smoothly. Further, in the present invention, even if the electrode is formed of a chromium-copper-chromium laminated structure, and when the electrode is formed, the copper portion is etched more than chromium to form a groove-shaped depression. The concave groove-like depression is filled with a liquid or semi-liquid dielectric material, which has an effect that the dielectric layer can be formed without generating bubbles.

Further, according to the present invention, when the dielectric material and the dielectric thin film sheet laminated on the substrate are formed of the same material or the same refractive index material, the substrate can be used in a display device. In addition, refraction or irregular reflection in the dielectric layer is eliminated, and display brightness can be improved by eliminating display light attenuation. This has the effect of producing the effect described above.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a front glass substrate side manufacturing process in a PDP in a dielectric layer forming method according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a back glass substrate side manufacturing process in the PDP in the dielectric layer forming method according to the first embodiment of the present invention.

FIG. 3 is an operation flowchart in the manufacturing process shown in FIG. 1;

FIG. 4 is an operation flowchart in the manufacturing process shown in FIG. 2;

FIG. 5 is an explanatory view of disposing electrodes on a front (rear) glass substrate in a PDP in a method of forming a dielectric layer according to another embodiment of the present invention.

FIG. 6 is an explanatory view of a front glass substrate side manufacturing process in a PDP according to a conventional dielectric layer forming method.

FIG. 7 is an enlarged sectional view of an electrode portion in a PDP according to a conventional dielectric layer forming method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 front glass substrate 10 a, 20 a recess 11 transparent electrode 12 bus electrode 12 a, 12 c chrome 12 b copper 12 d concave recess 13, 23 glass paste 14, 24 glass sheet 15 protective layer 17, 27 dielectric layer 20 back glass substrate 21 Address electrode 25 Partition wall 26 Phosphor layer

Claims (4)

[Claims] 1. A method for forming a dielectric layer on a substrate on which an electrode is provided so as to cover the electrode, wherein a liquid or semi-liquid is formed on the substrate on which the electrode is provided. A dielectric thin film sheet is disposed on the liquid or semi-liquid dielectric material by laminating the dielectric material, and the laminated liquid or semi-liquid dielectric material is solidified. A dielectric layer forming method by integrating the dielectric layer with a dielectric thin film sheet. 2. The method for forming a dielectric layer according to claim 1, wherein the liquid or semi-liquid dielectric material is attached onto a substrate by a screen printing method. Method. 3. The method for forming a dielectric layer according to claim 1, wherein the liquid or semi-liquid dielectric material and the dielectric thin film sheet are formed of the same material or a material having the same refractive index. A method of forming a dielectric layer. 4. A method for forming a dielectric layer of a gas discharge panel, wherein a three-layer electrode in which chromium, copper, and chromium are laminated in that order on the substrate is provided, and the electrode is covered with a dielectric layer made of glass. A step of applying a glass paste on a substrate on which the electrodes are provided to form a first glass layer having a predetermined thickness; and providing a green sheet of glass on the first glass layer. Forming a second glass layer having a predetermined thickness by heating, and simultaneously firing the laminated first glass layer and second glass layer to form an integrated glass dielectric layer. A method for forming a dielectric layer, comprising: