JPH10228865A - Manufacture of rear plate of plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PDP rear plate the production process of which is simplified and which comprises a uniform phosphor layer closely adhering to cell surfaces and sufficient cell spaces. SOLUTION: This manufacturing method comprises a process to pressure- insert a photosensitive phosphor body-containing dry film 3 into gaps between neighboring barrier ribs 2 of a plurality of barrier ribs formed on a substrate 1, a process to carry out exposure through a photomask 7 having a desired pattern, a process to develop and remove the regions which are not exposed, and a process to fire the pressure-inserted dry film 3. In this case, the dry film 3 is made thinner than the depth of the barrier ribs 3 and after the dry film 3 is pressure-inserted as to leave a void between the dry film 3 and the substrate 1, the pressure-inserted dry film 3 is further pressure-inserted to the substrate surface and then fired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a fluorescent display such as a plasma display panel (PDP).

[0002]

2. Description of the Related Art In general, a PDP has a structure in which a pair of electrodes arranged regularly on two opposing glass substrates are provided, and a gas mainly composed of Ne or the like is sealed between them. Then, a voltage is applied between these electrodes, and a discharge is generated in minute cells around the electrodes, so that each cell emits light to perform display. In order to display information, regularly arranged cells are selectively caused to emit light. This PDP has a direct current type (DC type) in which electrodes are exposed to the discharge space and an alternating current type (A) in which electrodes are covered with an insulating layer.
C type), and both types are further classified into a refresh driving method and a memory driving method according to differences in display functions and driving methods.

FIG. 3 shows an example of the configuration of an AC type PDP. In this figure, the front plate 31 and the back plate 32 are shown separated from each other. As shown, the front plate 31 and the back plate 32 made of glass are arranged in parallel and opposed to each other. On the front side of the face plate 32, a barrier rib 33 standing upright is fixed, and the barrier rib 33 holds the front plate 31 and the back plate 32 at a constant interval. On the back side of the front plate 31, a composite electrode composed of a sustain electrode 34 which is a transparent electrode and a bus electrode 35 which is a metal electrode is formed in parallel with each other, and a dielectric layer 36 is formed so as to cover the composite electrode. , And a protective layer 37 (M
gO layer).

On the front side of the back plate 32, address electrodes 38 are formed between the barrier ribs 33 so as to be orthogonal to the composite electrodes, and are formed in parallel with each other. A phosphor 39 is provided to cover. In this AC type PDP, by applying a predetermined voltage from an AC power supply between the composite electrodes on the front plate 1 to form an electric field, the display device is partitioned by the front plate 31, the back plate 32 and the barrier rib 33. Discharge is performed in each cell. The fluorescent substance 39 emits light by the ultraviolet light generated by the discharge, and the light transmitted through the front plate 31 is visually recognized by the observer. As a method of applying the phosphor, there has been proposed a method of using a photoresist film made of a photosensitive resin composition containing the phosphor (for example, JP-A-6-27392).
No. 5, JP-A-8-95239, JP-A-8-9
No. 5250).

[0005]

According to the above-mentioned proposed method, a dry film made of a photosensitive composition is pressed into a cell formed on a back plate of a PDP, baked after exposure and development, and baked. This method burns off organic matter in the film and forms a phosphor layer on the cell surface.However, since it is necessary to secure a sufficient discharge space in the fired cell, the photosensitive resin composition contains It is essential to increase the content of the organic substance, that is, to reduce the content of the phosphor. Under such circumstances, there is a problem that not only a large amount of heat energy is required for firing, but also a large amount of decomposition gas is generated during firing, so that the management of the firing furnace is complicated.

As a more serious problem, since the dry film impressed into the cell contains a large amount of organic substances, the dry film shrinks with the elapse of the firing time, and the fluorescent light to be finally formed is reduced. There is a problem that the body layer rises from the cell surface and the phosphor layer does not adhere to the cell surface. In order to solve such a problem, when the content of the phosphor in the dry film is increased, that is, when the content of the organic substance is reduced, the amount of the phosphor after firing increases, and a sufficient cell space is obtained. Can not secure.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide a PDP back plate which is simple in process and can form a uniform phosphor layer in close contact with a cell surface.

[0007]

The above object is achieved by the present invention described below. That is, the present invention provides a step of press-fitting a photosensitive phosphor dry film between a plurality of barrier ribs formed on a substrate, a step of exposing through a photomask having a desired pattern, and a step of developing and removing a non-exposed area. , Including the step of firing the press-fitted dry film
In the method for manufacturing a rear plate of DP, after making the thickness of the dry film less than the depth of the barrier rib, press-fit the dry film so as to leave a gap between the press-fit dry film and the substrate, and then remove the pressed dry film. This is a method for manufacturing a back plate of a PDP, which is press-fitted to a substrate surface.

According to the present invention, the dry film used in the present invention is thinner than the depth of the cell and is pressed into the cell, so that a sufficient discharge space is formed in the back plate, and thereafter, firing is performed. By doing so, the amount of organic matter to be burned is small, so that the time and heat energy used for burning off the organic matter are small, and the gas generated by baking is small, so that the baking furnace can be easily managed. The greatest advantage is that a sufficient discharge space is formed in the cell, and the phosphor layer finally formed in the cell is sufficiently adhered to the surface of the cell. Floating, peeling, etc. do not occur.

[0009]

Next, the present invention will be described in more detail with reference to preferred embodiments. A feature of the present invention lies in a method of forming a phosphor layer on a back plate of a PDP shown in FIG. Substrate 1 and rib 2 constituting back plate in the present invention
Are formed from conventionally known materials by a conventionally known method, and there is no special point in their shapes. The phosphor-containing dry film used in the present invention is disclosed in, for example,
No. 273925, JP-A-8-95239, JP-A-8-95250, and the like, or a dry film that has been previously proposed by the present applicant (Japanese Patent Application No. 8-316871). Specification).

Please refer to FIGS. 1 and 2 which schematically show the method of the present invention. FIGS. 1A and 1B show a state in which a phosphor-containing dry film 3 is press-fitted between a number of barrier ribs 2 formed on a substrate 1. The dry film 3 is obtained by laminating a soft photosensitive resin composition layer 3 composed of at least a phosphor and a photosensitive resin on a base film 4. In the present invention, the thickness a of the barrier film 2 is equal to the height of the barrier rib 2. h (cell depth). The dry film used here is, for example, as shown schematically in FIG. 4, a base film 41 of polyethylene terephthalate, polyethylene, polypropylene or the like, and a phosphor-containing photosensitive resin composition is formed on the base film. The photosensitive resin layer 42 is formed by applying and drying a coating liquid made of a material so as to have an appropriate dry thickness. As a preferred embodiment, the photosensitive resin layer 42 is provided between the base film 41 and the resin layer 42. By providing the release layer 43, the resin layer 42 can be easily separated.

In order to facilitate the transfer of the resin layer to the PDP back substrate, an adhesive layer 44 is provided on the surface of the resin layer 42.
Can be provided. Furthermore, in order to improve the preservability of these dry films, the resin layer 42 or the pressure-sensitive adhesive layer 44
A film similar to the above-mentioned base film may be adhered to the surface of the substrate to form the protective layer 45. In use, the protective layer 45 is peeled off, and the resin layer 42 is transferred to the surface of the PDP rear substrate. Such a dry film 3 is pressed into the upper part of the cell 6 by applying a pressure 5 using a pair of rubber rolls or the like, and when the base film 4 is peeled off, a space 6 is formed between the pressed film 3 and the substrate 1. Is formed (FIG. 1).
B). In the above description, the thickness a of the dry film is preferably about 2/3 to 1/3 of the height h of the rib.

Next, the dry film 3 press-fitted above the cell 6 is further press-fitted (second press-fitting) until it reaches the bottom of the cell. This second press-fitting is preferably performed using a soft cushion material such as air pressure, water pressure or sponge so as not to damage the rib 3,
In addition, it is preferable that the temperature during the operation is increased to about 80 to 120 ° C. so that the dry film is sufficiently softened. For example, when the second press-fitting of the dry film is performed by using air pressure, a “non-contact gap forming and curing apparatus (LOPSKY)” manufactured by LOPCO Corporation can be used. This device is a method of applying pressure to the dry film filled in the upper part of the cell with a film of air and forcing the dry film into the cell, injecting air from countless holes in the upper and lower gas film generators, By applying pressure from above and below while the slope is floating, the dry film can be pushed into the bottom of the cell. At this time, by setting the air injected from the device to an appropriate temperature,
The dry film is softened, and the press-fit of the dry film can be easily and uniformly performed.

The press-fitting of the dry film can be carried out by a water pressure instead of the air pressure, for example, by using a "Water jet resin deburring device (AX series)" manufactured by RIX Corporation. This device is capable of applying pressure to the dry film filled in the top of the cell with high-pressure water and press-fitting the dry film to the bottom of the cell. By doing so, it is possible to jet a water stream of a certain width, and by further vibrating, it is possible to apply pressure to the entire surface of the back plate substrate into which the dry film is pressed, and press the dry film into the bottom of the cell. In addition, since a continuous discharge plunger pump having a maximum discharge pressure of 1500 kgf / cm ² is used as a pressure generating device instead of a conventionally used high-pressure booster, operation reliability is high. Also, by setting the water jetted from this device to an appropriate temperature, the dry film is softened,
Drift film can be easily and uniformly pressed into the cell bottom.

FIG. 1C shows a state where the dry film is pressed into the bottom of the cell by the above method. After the dry film is pressed into the cell bottom in this manner, as shown in FIG. 1D, the exposed portion is cured by exposing it to light 8 having an appropriate wavelength through a photomask 7, and the exposed portion is cured into a developing solution. 2A, the dry film can be left only in a predetermined cell as shown in FIG. 2A. It is assumed that the dry film shown in FIG. 2A includes a phosphor that emits red light.
Next, FIG. 1A is used using a green light-emitting phosphor-containing dry film.
2A can be filled in a predetermined cell with the green dry film 9 (FIG. 2).
B). Further, the same operation is performed using the blue light-emitting phosphor-containing dry film 10, whereby the three colors of RGB dry film are respectively pressed into predetermined portions of the cell as shown in FIG. 2C.

By firing the state shown in FIG. 2C at an appropriate temperature, the organic matter in the dry film is burned off, and the three color RGB phosphor layers 3, 9, 1 are formed on the inner surface of the cell.
0 are respectively formed. Since the phosphor-containing dry film used in the present invention is not thick enough to completely fill the cell space as described above, the content of the phosphor in the dry film is reduced to the same value as that of the conventional dry film. It can be higher than the body content; for example, a preferred phosphor content is about 60-90% by weight in the dry film.

In the dry film, in addition to the phosphor and the photosensitive resin, dyes (coloring and coloring), adhesion promoters, antioxidants, thermal polymerization inhibitors, solvents, surface tension modifiers, stabilizers ,
Additives such as a chain transfer agent, an antifoaming agent, and a flame retardant can be appropriately added. In particular, by incorporating a silane-based, aluminum-based or titanate-based coupling agent, the adhesion of the phosphor layer finally formed in the cells of the PDP back plate to the cell surface can be improved. In addition, these coupling agents may be applied in advance to the cell surface of the back plate of the PDP.

When the photosensitive resin composition of the dry film used in the present invention is of a dilute alkali developing type, development after exposure is carried out with an alkali 1 such as sodium carbonate or potassium carbonate.
This is performed using a dilute aqueous solution of about 2% by weight. After the development processing, the cell forming substrate is baked at 500 to 550 ° C. to fix the phosphor inside the cell. In this way, the phosphor can be fixed on the glass substrate. Full color P
In order to form the DP, the above-described transfer step, exposure step, and baking step are repeatedly performed using a photoresist film containing each of red, blue, and green phosphors.

[0018]

Next, the present invention will be described more specifically with reference to examples. In the examples, “%” or “parts” is based on weight unless otherwise specified. Example 1 Preparation of photosensitive resin composition 23 parts of the following base polymer, 27 parts of the following ethylenically unsaturated compound, 4 parts of a photopolymerization initiator having the following formulation, 128 parts of the following phosphor and 20 parts of a volatile organic material The mixture was mixed to prepare a photosensitive resin composition. (Base polymer) The copolymerization ratio of methyl methacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate / methacrylic acid is 55/8/15 on a weight basis.
/ 22 copolymer (acid value 143.3, glass transition point 66.3 ° C, weight average molecular weight 80,000)

(Ethylenically unsaturated compound) A mixture of trimethylolpropane triacrylate / polyethylene glycol (600) dimethacrylate / ethylene oxide-modified phthalic acrylate (manufactured by Kyoeisha Yushi Kogyo Co., Ltd.) in a weight ratio of 20/10/6 (light Polymerization initiator) benzophenone / p, p'-diethylaminobenzophenone / 2,2-bis (o-chlorophenyl) 4,5,4 ', 5'-tetraphenyl-1,2'
A mixture of biimidazole in a weight ratio of 8 / 0.15 / 1

(Phosphor) Blue light-emitting phosphor: BaMgAl ₁₀ O ₁₇ : Eu (trade name:
KX-501A, manufactured by Kasei Optonics Co., Ltd. Red light-emitting phosphor: Y ₂ O ₃ : Eu (trade name: LP-RE)
I, manufactured by Kasei Optonics Co., Ltd.) Green-emitting phosphor: Zn ₂ SiO ₄ : Mn (trade name: P1-
G1S, manufactured by Kasei Optonics)

(Volatile organic substance) dioctyl phthalate (boiling point 390 ° C. at 760 mmHg, 225 to 2
30 ° C at 4mmHg)

Preparation of Dry Film The above photosensitive composition was coated on a polyester film having a thickness of 20 μm by using a blade coater.
After leaving for 30 minutes, the film was dried in an oven at 90 ° C. for 30 minutes to obtain a dry film of the present invention having a photosensitive composition having a film thickness of 30 μm (however, no protective film was provided).

Lamination on a glass substrate This dry film was preheated in an oven to 60 ° C. on a glass substrate [a conductive circuit and a barrier rib (height: 150 μm,
A phosphor screen forming substrate having a width of 50 μm and a pitch of 200 μm]], a laminating roll temperature of 100 ° C., a roll pressure of 3 kg / cm ² , and a laminating speed of 1.5 m / m.
The laminate was made in. Thereafter, the laminated film was subjected to an air press at a pressure of 0.1 kg / cm ² and a temperature of 100 ° C. for 5 minutes.

After exposure and development air press, the phosphor screen pattern shape (line width opening 110
μm, pitch 200 μm), and a pattern mask is superimposed on the laminate film surface so that an exposed portion is formed.
3kw with the exposure machine MAP-200 made by Dainippon Screen
Exposure was performed at 400 mJ / cm ^{2 with} an ultra-high pressure mercury lamp. After a hold time of 15 minutes after exposure, the polyester film was peeled off and developed at 20 ° C. using a 1% aqueous sodium carbonate solution for 1.5 times the minimum development time. Next, post-baking (water-drying) was performed at 160 ° C. for 30 minutes. The above steps were performed for each of the dry films including the phosphors of three colors.

Drying After the above development, the whole was dried in a drying furnace at 250 ° C. and 4 mmHg for 10 minutes, and dioctyl phthalate contained in the photosensitive composition film was evaporated and dried.

Firing Next, the glass substrate filled with each of the three color phosphor compositions is raised from room temperature to 550 ° C. in a firing furnace in one hour, and the resin component in the phosphor composition film is burned off. Then, a phosphor layer was formed to obtain a PDP back plate. This phosphor layer was sufficiently adhered to the substrate, there was no lifting of the phosphor layer, and a sufficient discharge space was secured.

Examples 2 to 4 As shown in Table 1 below, a photosensitive resin composition was obtained in the same manner as in Example 1 except that the composition of the photosensitive composition of Example 1 was changed. A dry film was obtained in the same manner as in Example 1. In addition, in Example 2, the drying process was not performed.

[Table 1]

A back plate of a PDP was manufactured using these dry films. The ribs on the rear substrate of the PDP have a height of 150 μm, the interval between the ribs is 200 μm, and the rib width is 50 μm, so that the depth of the groove-shaped cell is 150 μm and the groove width is 150 μm. .
The photosensitive resin layer of the dry film is superposed on the cell surface, and the laminated film is passed between rubber rolls for lamination. After the photosensitive resin layer is pressed into the cell, the polyester film is peeled off. Then, an air press was performed in the same manner as in Example 1. After the air press, exposure and development were performed in the same manner as in Example 1 through a photomask having a pixel pattern of the same color as the color light of the cell and the phosphor.
Thereafter, drying and baking were performed in the same manner as in Example 1 to form a phosphor layer, and a PDP back plate (only one color) was obtained.
This phosphor layer was sufficiently adhered to the substrate, there was no lifting of the phosphor layer, and a sufficient discharge space was secured.

Example 5 The press-fitting of a dry film in Example 1 was carried out using a “water jet resin deburring device (AX
Series) ”, water temperature 80 ° C, water pressure 5kgf / cm
A back plate of a PDP was formed in the same manner as in Example 1 except that Step ² was performed. The phosphor layer of the back plate was sufficiently adhered to the substrate, there was no lifting of the phosphor layer, and a sufficient discharge space was secured.

Comparative Example 1 A dry film was prepared in the same manner as in Example 1, except that the thickness of the photosensitive composition layer was 160 μm. Using this dry film, a cell was filled only with a laminate without using an air press, and a back plate of a PDP was produced in the same manner as in Example 1 except for the above. As a result, the discharge space was reduced in the final shape of the fired cell.

COMPARATIVE EXAMPLE 2 A phosphor layer having a thickness of 160 μm was formed by changing the phosphor of the composition of the photosensitive resin composition of Example 1 to 17 parts without using an air press. The back plate of the PDP was manufactured in the same manner as in Example 1 except that the cell was filled only with the laminate. In Comparative Example 2, since the absolute amount of the phosphor is calculated to be the same as that of Example 1, the discharge space becomes the same as that of Example 1 in the final shape of the fired cell. Due to the large amount of resin inside, peeling of the phosphor layer occurred during firing.

[0032]

According to the present invention, since the dry film used in the present invention is thinner than the depth of the cell and is pressed into the cell, a sufficient discharge space is formed in the back plate, and By baking, the amount of organic matter to be burned is small, so that the time and heat energy used for burning off the organic matter are small, and the gas generated by baking is small, so that the baking furnace can be easily managed. .
The greatest advantage is that a sufficient discharge space is formed in the cell, and the phosphor layer finally formed in the cell is
Since the phosphor is sufficiently adhered to the surface of the cell, the phosphor does not float or peel off as in the prior art.

[Brief description of the drawings]

FIG. 1 illustrates a method of the present invention.

FIG. 2 illustrates a method of the present invention.

FIG. 3 is a diagram illustrating the configuration of a PDP.

FIG. 4 is a configuration diagram of a dry film.

[Explanation of symbols]

 1: Substrate 2: Barrier rib 3: Drift film (red) 4: Base film 5: Pressure 6: Cell (space) 7: Photomask 8: Light 9: Drift film (green) 10: Drift film (blue) 31: Front Face plate 32: Back plate 33: Barrier rib 34: Sustain electrode 35: Bus electrode 36: Dielectric layer 37: Protective layer 38: Address electrode 39: Phosphor layer 41: Base film 42: Photosensitive resin layer 43: Release layer 44: adhesive layer 45: protective layer

Claims (6)

[Claims] A step of press-fitting a photosensitive phosphor dry film between a plurality of barrier ribs formed on a substrate; a step of exposing through a photomask having a desired pattern; a step of developing and removing a non-exposed area; In the method for manufacturing a back plate of a plasma display panel including a step of firing a press-fitted dry film, a thickness of the dry film is set to be less than a depth of a barrier rib, and a dry process is performed so as to leave a gap between the press-fitted dry film and the substrate. A method for manufacturing a rear plate of a plasma display panel, comprising: after press-fitting a film, press-fitting the press-fitted dry film onto a substrate surface. 2. The method for manufacturing a back plate of a plasma display panel according to claim 1, wherein the press-fitted dry film is pressed into the substrate surface by an air press. 3. The method for manufacturing a back plate of a plasma display panel according to claim 1, wherein the press-fitted dry film is pressed into the substrate surface by a water jet. 4. The method for manufacturing a back plate of a plasma display panel according to claim 1, wherein the press-fitted dry film is pressed into the substrate surface by a cushion material. 5. A dry film having three colors of red, green and blue.
3. The method for manufacturing a back plate of a plasma display panel according to claim 1, wherein the three types of films include phosphors that emit light of different colors, and the dry film according to claim 1 is pressed into each of the films. 6. The method for manufacturing a back plate of a plasma display panel according to claim 1, wherein the dry film is formed by laminating a photosensitive resin composition layer comprising at least a phosphor and a photosensitive resin on a base film.