KR100495020B1 - A transfer film for preparing dielectric substance layer of the plasma display panel - Google Patents

Abstract

The present invention provides a method of manufacturing a plasma display panel including a novel forming process capable of efficiently forming a dielectric layer having a large film thickness.

And forming a dielectric layer on the surface of the glass substrate by transferring the film forming material layer formed on the support film to the surface of the glass substrate on which the electrode is fixed and firing the transferred film forming material layer. do.

Description

A Transfer Film For Preparing Dielectric Substance Layer of The Plasma Display Panel}

The present invention relates to a method for manufacturing a plasma display panel, and more particularly, to a method for manufacturing a plasma display panel including a novel process for forming a dielectric layer on a glass substrate.

Recently, plasma displays have attracted attention as flat fluorescent displays. 1 is a schematic diagram showing a cross-sectional shape of an AC plasma display panel (hereinafter also referred to as "PDP"). In this figure, symbols (1) and (2) are oppositely arranged glass substrates, (3) are partition walls, and cells are partitioned by these glass substrates (1), glass substrates (2) and partition walls (3). It is. Symbol (4) is a bus electrode fixed to the glass substrate 1, (5) is an address electrode fixed to the organic substrate 2, (6) is a fluorescent substance retained in the cell, and (7) is a bus It is a dielectric layer formed on the surface of the glass substrate 1 so that the electrode 4 may be covered, and (8) is a protective layer which consists of magnesium oxide, for example. The dielectric layer 7 is formed by a glass sintered body, and the film thickness is 20-50 micrometers, for example.

As the method for forming the dielectric layer 7, a paste-like composition containing glass powder is produced, and the film-forming material layer is formed by applying the paste-like composition to the surface of the glass substrate 1 by screen printing and drying. Subsequently, the method of removing an organic substance and baking a glass powder by baking this film forming material layer is known.

Here, the thickness of the film forming material layer formed on the glass substrate 1 is 1.3 to the film thickness of the dielectric layer 7 to be formed in consideration of the eye loss of the film thickness due to the removal of the organic material in the firing step. It is necessary to set it to about 1.5 times. For example, in order to make the film thickness of the dielectric layer 7 into 20-50 micrometers, it is necessary to form the film forming material layer about 30-70 micrometers thick.

On the other hand, when apply | coating the paste composition containing the said glass powder by the screen printing method, the coating film thickness formed by one coating process is about 15-25 micrometers.

For this reason, in order to make a film forming material layer into a predetermined thickness, it is necessary to apply | coat repeatedly the said pasty composition with respect to the surface of a glass substrate several times (for example, 2 to 5 times).

(1) The operation (multi-printing) of repeatedly applying the paste composition by the screen printing method a plurality of times is complicated and inferior in workability. Moreover, it is necessary to confirm the dispersion state of a component every time apply | coating a pasty composition, and when dispersion defects, such as precipitation of a glass powder, arise, redispersion process must be performed. Therefore, the conventional method of forming the dielectric layer through such a complicated coating process is problematic in view of the production efficiency of the PDP, and becomes a particularly significant problem in accordance with the enlargement of the display panel.

(2) When the film forming material layer is formed by multiple printing using the screen printing method, the dielectric layer formed by firing the film forming material layer does not have a uniform film thickness (for example, within a tolerance of ± 5%). do. This is because it is difficult to uniformly apply the paste composition to the surface of the glass substrate in multiple printing by the screen printing method. The larger the coating area (panel size) and the higher the number of coatings, the more uniform the film thickness in the dielectric layer. The degree increases. Therefore, in the panel material (glass substrate having the dielectric layer) obtained through the coating process by multiple printing, nonuniformity occurs in the dielectric properties due to the nonuniformity of the film thickness in the plane, and the nonuniformity of the dielectric properties causes the display defect ( Brightness unevenness).

(3) In the screen printing method, a small amount of air may be rolled up by the paste composition passing through the screen, and may remain as bubbles in the film forming material layer. Thus, when the film-forming material layer containing bubbles is fired, pinholes or cracks are generated in the formed dielectric layer. When the (n + 1) th layer is formed again, the nth layer is susceptible to damage by squeegee, which may cause cracks in the dielectric layer. Therefore, the dielectric layer whose insulation is broken by pinholes or cracks cannot exhibit desired dielectric properties.

(4) In the screen printing method, the mesh shape of the screen plate can be transferred to the surface of the film forming material layer, and the dielectric layer formed by firing the film forming material layer is inferior in surface smoothness.

The present invention is based on the above circumstances, and a first object of the present invention is to provide a method for producing a PDP comprising a novel forming step capable of efficiently forming a dielectric layer having a large film thickness. It is a second object of the present invention to provide a method for producing a PDP comprising a novel forming process capable of efficiently forming a dielectric layer required for a large panel. It is a third object of the present invention to provide a method for producing a PDP having a dielectric layer having excellent uniformity in film thickness. A fourth object of the present invention is to provide a method for producing a PDP having a highly reliable dielectric layer free from defects such as pinholes and cracks. A fifth object of the present invention is to provide a method for producing a PDP having a dielectric layer having excellent surface smoothness.

In the method for producing a PDP of the present invention, a dielectric layer is formed on the surface of the glass substrate by transferring the film forming material layer formed on the support film to the surface of the glass substrate on which the electrode is fixed and firing the transferred film forming material layer. It characterized by including a process.

In addition, in the method for producing a PDP of the present invention, a paste-like composition containing glass powder, a binder resin and a solvent is applied onto a support film to form a film forming material layer, and the electrode is formed on the support film. And a step of forming a dielectric layer on the surface of the glass substrate by transferring the surface of the fixed glass substrate and firing the transferred film-forming material layer.

In the manufacturing method of the PDP of this invention, it is preferable to apply | coat a paste composition with a roll coater, and to form a film forming material layer on a support film. Moreover, it is preferable that the thickness of a film forming material layer is 10-200 micrometers. In addition, it is preferable that the glass powder contained in a film forming material layer is a mixture of 60-90 weight% of zinc oxide, 5-20 weight% of boron oxide, and 5-20 weight% of silicon oxide.

In the manufacturing method of this invention, the film forming material layer used as a dielectric layer by baking is not formed by directly apply | coating the paste composition containing glass powder on a rigid glass substrate, but is a support film which has flexibility It is formed by apply | coating on. For this reason, as a coating method of the said paste composition, the coating method by a roll coater etc. can be employ | adopted, and by this, a film forming material layer with large film thickness and excellent uniformity of film thickness (for example, 100 micrometers +/- 5micrometer) ) Can be formed on the support film. And the film formation material layer can be reliably formed on a glass substrate by the simple operation which collectively transfers the film formation material layer thus formed with respect to the surface of a glass substrate. Therefore, according to the manufacturing method of the present invention, process improvement (high efficiency) can be achieved in the dielectric layer forming step, and quality improvement (expression of stable dielectric properties) of the dielectric layer formed at the same time can be achieved.

Hereinafter, the manufacturing method of this invention is demonstrated in detail. In the manufacturing method of this invention, a dielectric layer is formed in the surface of a glass substrate by the transfer process of a film forming material layer by using a transfer film, and the baking process of a film forming material layer.

(1) transfer film

The transfer film used for the manufacturing method of this invention is comprised from a support film and the film formation material layer formed on this support film.

It is preferable that the support film which comprises a transfer film is a resin film which has heat resistance and solvent resistance, and has flexibility. Since the support film has flexibility, the paste-like composition can be applied by a roll coater, and the film-forming material layer can be stored and supplied only in a roll state. Examples of the resin forming the support film include fluorine-containing resins such as polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, polyfluoroethylene, nylon, cellulose, and the like. Can be mentioned. The thickness of a support film is 20-100 micrometers, for example.

The film forming material layer constituting the transfer film can be formed by applying a paste-like composition containing glass powder, a binder resin, and a solvent as essential components on the support film, and drying the coating film to remove some or all of the solvent. have.

Glass powders that are essential components of the pasty composition include (1) a mixture of zinc oxide, boron oxide, and silicon oxide (ZnO-B ₂ O ₃ -SiO ₂ based), (2) lead oxide, boron oxide, and silicon oxide (PbO-B ₂ O ₃ -SiO _{2 type} ), ③ lead oxide, boron oxide, silicon oxide, a mixture of aluminum oxide (PbO-B ₂ O ₃ -SiO ₂ -Al ₂ O _{3 type} ), ④ lead oxide, zinc oxide, boron oxide, And a mixture of silicon oxide (PbO-ZnO-B ₂ O ₃ -SiO _{2 type} ). Among them, a paste-like composition containing a mixture of ZnO-B ₂ O ₃ -SiO ₂ system containing zinc oxide as a main component is preferable in that it can be calcined under relatively low temperature conditions (500 ° C. or lower).

The binder resin, which is an essential component of the paste composition, can have a suitable adhesiveness and bind the glass powder, and is not particularly limited as long as the binder resin can be completely oxidized and removed by baking (400 ° C to 500 ° C) of the film forming material layer. Acrylic ester resins such as polymethyl methacrylate and polybutyl methacrylate; Cellulose resins, such as ethyl cellulose and nitrocellulose, can be illustrated.

As a solvent which is an essential component of the pasty composition, it is preferable to impart an appropriate viscosity (for example, 500 to 10,000 cp) to the pasty composition, and be easily evaporated and removed from the pasty composition by a drying treatment. For example, terebin oil, cellosolve (ethyl cellosolve), methyl cellosolve, terpineol, butyl carbitol acetate, butyl carbitol, benzyl alcohol, methyl lactate, ethyl lactate and the like can be suitably used.

In addition to the above essential components, the paste composition may include various additives such as dispersants, tackifiers, plasticizers, surface tension regulators, stabilizers, antifoaming agents, and the like as optional components.

As an example of a preferred paste-like composition, 100 parts by weight of a mixture consisting of 60 to 90% by weight of zinc oxide, 5 to 20% by weight of boron oxide, and 5 to 20% by weight of silicon oxide as a glass powder, and polymethylmethacrylate (binder Resin) 2-10 weight part and 10-50 weight part of terpineol (solvents) as an essential component.

As a method of apply | coating a paste composition on a support film, it is necessary to be able to form a coating film with a large film thickness (for example, 30 micrometers or more) excellent in the uniformity of film thickness efficiently, specifically, to a roll coater. The coating method by, the coating method by a doctor blade, the coating method by a curtain coater, the coating method by a wire coater, etc. are mentioned as a preferable thing.

Moreover, it is preferable that the mold release process is given to the surface of the support film to which a paste composition is apply | coated. Thereby, peeling operation of a support film can be performed easily in the transfer process mentioned later.

As drying conditions of a coating film, it dries for 0.5 to 30 minutes at 50-150 degreeC, for example, and the residual ratio (content rate in a film forming material layer) of a solvent after drying becomes within 10 weight% normally.

Although the thickness of the film formation material layer formed as mentioned above changes with content rate of a glass powder and the kind and size of a panel, it is 10-200 micrometers, Preferably it is 30-100 micrometers. If the thickness is less than 10 m, the film thickness of the finally formed dielectric layer is too small to ensure desired dielectric properties. Usually, when this thickness is 30-100 micrometers, the film thickness of the dielectric layer calculated | required for a large panel can fully be ensured.

In addition, a protective film layer may be provided on the surface of the film forming material layer in the transfer film. As such a protective film layer, a polyethylene film, a polyvinyl alcohol-type film, etc. are mentioned.

(2) Transfer process of film forming material layer

The production method of the present invention is characterized by transferring the film-forming material layer constituting the transfer film to the surface of the glass substrate on which the electrode is fixed, using the transfer film produced as described above.

An example of the transfer process is as follows. After peeling the protective film layer of the transfer film used as needed, the transfer film is superimposed so that the surface of a film formation material layer may contact the surface (electrode fixing surface) of a glass substrate, and heat this transfer film with a heating roller etc. After pressing, the support film is peeled off from the film forming material layer. In this way, the film forming material layer is transferred to and adhered to the surface of the glass substrate. Here, as transfer conditions, the surface temperature of a heating roller is 80-100 degreeC, the roll pressure by a heating roller is 1-5 kg / cm <2>, and the moving speed of a heating roller is 0.5-10.0 m / min, for example. In addition, the glass substrate may be preheated, and the preheating temperature can be 40-60 degreeC, for example.

(3) Firing Process of Film Forming Material Layer

The film forming material layer transferred to the surface of the glass substrate is fired. Specifically, by arranging the glass substrate on which the film forming material layer is formed under a high temperature atmosphere, organic substances (eg, binder resins, remaining solvents, various additives) contained in the film forming material layer are removed by decomposition or the like, and the inorganic material. Phosphorus glass powder melts and sinters. In this way, a dielectric layer made of a glass sintered body is formed on the glass substrate. Here, the firing temperature varies depending on the constituent materials in the film forming material layer, but is, for example, 400 to 500 ° C.

<Example>

Hereinafter, although the Example of this invention is described, this invention is not limited to these. In addition, "part" shows a "weight part" below.

<Production process of transfer film>

100 parts of a ZnO-B ₂ O ₃ -SiO ₂ based mixture having a composition of 80 wt% zinc oxide, 10 wt% boron oxide, and 10 wt% silicon oxide as a glass powder, methacrylic acid (10 wt%) and methacrylic acid By kneading 30 parts of a copolymer with methyl (90% by weight) (weight average molecular weight: 100,000) (binder resin), 30 parts of ethylene glycol diacrylate (adhesive agent) and 60 parts of methyl cellosolve (solvent), A paste composition having a viscosity of 5,000 cp was prepared.

Subsequently, the prepared paste-like composition was applied onto a support film (200 mm wide, 30 m long, 38 μm thick) made of a polyethylene terephthalate (PET) film previously released by using a roll coater to form a coating film. It was. The solvent was completely removed by drying the formed coating film at 110 degreeC for 2 minutes, and the transfer film in which the 50-micrometer-thick film formation material layer was formed on the support film was produced.

<Transfer process of film forming material layer>

The transfer film was overlaid so that the surface of the film formation material layer might contact the surface (fixed surface of the bus electrode) of the glass substrate for 15 cm (6 inch) panels, and this transfer film was thermocompression-bonded with the heating roller. Here, crimping | compression-bonding conditions made the surface temperature of a heating roller 120 degreeC, the roll pressure 4 kg / cm <2>, and the moving speed of a heating roller 1 m / min. After the thermocompression bonding was completed, the supporting film was peeled off from the film forming material layer. As a result, the film-forming material layer was transferred to and adhered to the surface of the glass substrate. The film thickness of the film-forming material layer was measured and found to be in the range of 50 µm ± 2 µm.

<Firing Process of Film Forming Material Layer>

The transferred film-forming material layer was heated to 450 ° C. at a temperature increase rate of 10 ° C./min at room temperature, and calcined for 30 minutes in a temperature atmosphere of 450 ° C. to form a dielectric layer made of glass sintered body on the surface of the glass substrate. As a result of measuring the film thickness of this dielectric layer, it was in the range of 35 µm ± 1.5 µm, and the film thickness was excellent in uniformity.

<Evaluation of Dielectric Layer>

In this way, five panel materials which consist of the glass substrate which has a dielectric layer were produced. As a result of observing the cross-section and surface of the formed dielectric layer with a scanning electron microscope, no film defects such as pinholes or cracks were found in the dielectric layers formed from all panel materials.

Comparative Example

A paste-like composition having the same composition as in the above-described embodiment was prepared, and a glass paste was applied on a glass substrate (the same substrate used in the example) by a multiple printing method using a screen printing method to form a film forming material layer. Here, the dry film thickness by single coating is about 15-17 micrometers, and the application | coating frequency | count was made three times. The film thickness of the obtained film forming material layer was in the range of 50 µm ± 5 µm. Next, the baking process was performed similarly to the said Example, and the dielectric layer was formed in the surface of a glass substrate. As a result of measuring the film thickness of this dielectric layer, it was in the range of 35 µm ± 4 µm, and the uniformity of the film thickness was inferior. In this way, five panel materials which consist of the glass substrate which has a dielectric layer were produced. As a result of observing the cross-section and the surface of the formed dielectric layer with a scanning electron microscope, film defects such as pinholes and cracks were confirmed for 60% (three units) of panel material.

According to the method of the present invention, even a dielectric layer having a large film thickness can be efficiently formed by a simple method including a transfer process of the film forming material layer, the process can be improved in the process of forming the dielectric layer, and the production efficiency of the PDP can be improved. Can be improved.

In addition, according to the method of the present invention, a dielectric layer having a large film thickness can be formed while maintaining uniformity of the film thickness (within the film thickness tolerance within 5%), and the dielectric layer required for a large panel can be efficiently formed.

In addition, according to the method of the present invention, it is possible to form a dielectric layer having excellent film thickness uniformity and surface smoothness and free of defects such as pinholes and cracks. Therefore, stable dielectric properties are exhibited by such highly reliable dielectric layers, and as a result, display defects such as luminance unevenness do not occur in the PDP produced by the method of the present invention.

1 is a schematic diagram showing a cross-sectional shape of an AC plasma display panel.

<Explanation of symbols for the main parts of the drawings>

1: glass substrate 2: glass substrate

3: bulkhead 4: bus electrode

5 address electrode 6 fluorescent material

7 dielectric layer 8 protective layer

Claims (4)

(i) A paste-like composition having a viscosity of 500 to 10,000 cp containing a glass powder, an acrylic acid ester resin and a solvent is applied onto a support film made of a polyethylene terephthalate film having a mold release treatment on the surface thereof and having flexibility, A transfer film having a film forming material layer having a film thickness of 30 to 200 μm, (ii) As for the film formation material layer formed on the said support film, the surface temperature of a heating roller is 80-100 degreeC, and the roll pressure by a heating roller is 1-5 kg / cm <^2> , on the surface of the glass substrate with which the electrode was fixed; The transfer speed of the heating roller is for transferring to the condition of 0.5 to 10.0 m / min, (iii) the transferred film forming material layer is baked, and a dielectric layer made of a glass sintered body in which the organic substance contained in the film forming material layer is decomposed and removed is formed on the surface of the glass substrate, The film thickness tolerance of the dielectric layer formed on the plasma display panel formed using the transfer film is within ± 5%, the transfer film for forming a dielectric layer of the plasma display panel. 2. The transfer film for forming a dielectric layer of a plasma display panel according to claim 1, wherein the film forming material layer has a thickness of 30 to 100 m. The plasma display panel according to claim 1, wherein the glass powder contained in the film forming material layer is a mixture of 60 to 90 wt% zinc oxide, 5 to 20 wt% boron oxide, and 5 to 20 wt% silicon oxide. Transfer film for dielectric layer formation. The plasma display panel according to claim 2, wherein the glass powder contained in the film forming material layer is a mixture of 60 to 90 wt% zinc oxide, 5 to 20 wt% boron oxide, and 5 to 20 wt% silicon oxide. Transfer film for dielectric layer formation.