JPH08273536A - Method for forming barrier for plasma display panel and transfer sheet for it - Google Patents

Abstract

PURPOSE: To form a barrier forming layer of uniform thickness only within an effective display area on a glass substrate in forming a barrier on a plasma display panel using sandblasting method. CONSTITUTION: From a transfer sheet S having a barrier forming layer 11 on a base film 10, the barrier forming layer 11 is transferred onto a glass substrate 13, after which a resist pattern is formed while unnecessary portions of the barrier forming material are removed by sandblasting. With the use of unnecessary portions of the base film 10 which are slit, the barrier forming layer 11 which has no undulation at its periphery and is of uniform thickness up to its edges can be formed. A barrier having very few surface irregularities can be formed since the barrier forming material applied is reversed so that its lower side serves as the upper surface of the barrier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing process of a plasma display panel (hereinafter referred to as PDP), and more particularly to a method for forming a barrier of PDP and a transfer sheet used for the method.

[0002]

2. Description of the Related Art A PDP, which is a gas discharge panel, has a large number of cells as minute discharge spaces sandwiched between two substrates such as glass, and discharges or emits light for each cell. The phosphor is made to emit light by ultraviolet rays. A barrier is generally provided between these minute cells in order to prevent interference between the cells and to keep the distance between both substrates constant. Further, in the PDP, in order to make the discharge space as large as possible to obtain high-intensity light emission, a barrier having a narrow wall and a narrow width and a high height is required. Especially for high-definition displays, height 100
A barrier having a high aspect ratio of 30 to 50 μm with respect to μm is desirable.

By the way, a pattern is generally formed by screen printing for forming the barrier. However, in screen printing, the film thickness that can be formed by one printing is several tens of μm at most, and therefore, many printings and dryings are performed. Times, generally 1
The target film thickness was obtained by repeating about 0 times. However, since the coating film formed by screen printing has a concave peripheral portion and a convex shape, when overprinting a large number of times, there is a problem that sagging accumulates and the bottom portion spreads, and a fine pitch barrier is used. There was a limit. Further, in screen printing, there is a limit in pitch accuracy due to distortion of the printing plate, and there is a problem in increasing the size of the panel.

As a method capable of solving such a problem,
A barrier formation method using a subtractive method has been proposed (Electronic Materials, 1938, No. 11, p13).
8). That is, this is a method in which after forming the barrier forming layer, a subtractive resist pattern is formed on the upper surface by printing or photolithography, and the barrier forming material in the resist opening is removed. Among them, what is called a sandblasting method, in which fine particles mixed with a compressed gas are jetted at high speed to physically perform etching, is particularly expected. By using this sandblasting method, it is possible to process the barrier material into a desired shape in which the wall surface is cut vertically and the width is narrow and the height is high. Further, by adopting a photolithography process for patterning the resist, it is possible to increase the pattern accuracy, and it is possible to adapt to a larger panel.

[0005]

In the case of forming a barrier by the above sandblast method, a step of forming a barrier forming layer on a glass substrate is first required. Conventionally, in this step, an ink-formed barrier forming layer is formed. A method of directly applying the material onto a glass substrate by a multi-layer printing by screen printing or a coating method such as blade coating or roll coating is generally used.

However, in the former screen printing, solid printing is performed many times (usually 5 to 10 times) to obtain a predetermined film thickness, and drying is repeated each time, so productivity is poor, and a gauze pattern is obtained. Therefore, there is a problem that unevenness occurs on the surface of the coating film. On the other hand, in the latter coating method, P
Since the soda lime float glass plate that is usually used in DP has a large plate thickness unevenness, the coating film thickness is affected by the plate thickness, and it is difficult to form the barrier forming layer with a uniform film thickness. In addition, since an extremely large film thickness of 150 to 200 μm is obtained after drying, it is difficult to avoid the undulation (framing) of the peripheral edge portion during the drying process in a single application. Further, in order to expose the alignment mark necessary for alignment of resist exposure, it is desirable to form a barrier forming layer leaving a non-coated area at the peripheral edge of the substrate. It is extremely difficult to apply.

The present invention has been made in view of the above problems, and an object thereof is to uniformly form a barrier of PDP by a sandblast method only in an effective display area on a glass substrate. (EN) A barrier forming method capable of forming a barrier forming layer having a uniform film thickness, thereby forming a barrier having a good shape with high production efficiency, and a transfer sheet used therefor.

[0008]

In order to achieve the above object, a first barrier forming method according to the present invention comprises a transfer sheet having a barrier forming layer on a base film, the barrier forming layer being formed on a glass substrate. A first step of transferring to the substrate, a second step of forming a resist pattern on the upper surface of the transferred barrier forming layer,
The method includes a third step of removing the barrier forming material in the opening of the resist pattern by sandblasting, a fourth step of removing the resist remaining on the barrier forming material, and a fifth step of sintering the barrier forming material by firing. It is characterized by that.

The transfer sheet used in the first method is prepared by applying an inked barrier forming material on a base film to form a barrier forming layer. As a coating method, blade coating, comma coating, reverse roll coating, extrusion coating and the like are particularly preferably used. When it is difficult to obtain a predetermined film thickness with one coating, it is possible to repeat coating and drying a plurality of times.

The base film is preferably a film having a high peeling property, and further, a film which is not attacked by the solvent in the ink of the barrier forming material and does not shrink in the heating and drying process. For example, a PET film which has been subjected to a silicon treatment is preferable. It is preferably used. If the base film is thin, wrinkles are likely to occur in the step of applying and drying the barrier forming layer,
It is preferable to use one having a thickness of 70 μm or more.

The barrier-forming material is mainly composed of an inorganic powder such as alumina or zirconia that does not soften during the firing process and a low-melting glass powder that flows and adheres during the firing process. Further, in order to form a coating film of these powders before firing, those containing a small amount of a resin which can be vaporized, burned and decomposed by firing are generally used. In order to facilitate grinding by sandblasting, it is desirable to use a resin having low flexibility and brittleness as the barrier forming material, and to reduce the ratio of resin components as much as possible. However, since such a barrier forming layer lacks flexibility and is weak against bending, there arises a problem that cracks occur when the film is wound or peeled from the base film. In order to solve this problem, a volatile substance is left as a plasticizer in the barrier forming layer formed on the base film, transferred onto a glass substrate to form a resist pattern, and then dried again. The method of removing the plasticizer is preferably applied. By leaving the volatile substance in this way, the barrier forming layer is once formed on the base film,
After drying, it is also possible to peel off the base film containing the volatile substance and to bond only the barrier forming layer onto the glass substrate. In this way, the base film can be reused.

The barrier-forming layer formed on the base film may be directly bonded to the glass substrate by thermocompression bonding in some cases, but in order to ensure the adhesion,
An adhesive layer is preferably provided on the glass substrate or the barrier forming layer. As the adhesive layer, one that is burned at a low temperature in the firing step and hardly causes a carbide to remain is preferably used, and specifically, a cellulose resin and an acrylic resin to which a plasticizer is added are preferable. These adhesives are softened by heating and adhere the barrier forming layer and the glass substrate. A thickness of 2 μm or less is sufficient for the adhesive layer. The same applies when the base film is peeled off and only the barrier forming layer is adhered to the glass substrate.

When forming a resist pattern on the barrier forming layer, it is possible to directly pattern by screen printing, but in the case of performing high-precision processing on a large area, a photoresist is used as a resist material, It is preferably formed by a photolithography method. As the photoresist, either a dry film resist or a liquid resist can be used, and these can be used in combination. Further, both positive type and negative type can be used. Then, in order to prevent the barrier forming material from being damaged during resist development, it is preferable to use a water developing type or alkaline aqueous solution type resist.

Although the resist can be peeled off by burning out at the time of baking, it is preferably carried out by providing a peeling step using a peeling solution. When performing peeling using a peeling liquid, a method of spraying the peeling liquid by spraying is preferable for obtaining stability in mass production.

A second barrier forming method according to the present invention is a first method of laminating a transfer sheet having a photoresist layer and a barrier forming layer on a base film on a glass substrate with the barrier forming layer as an inner surface side. Step, second step of peeling the base film, third step of pattern exposing the photoresist layer, fourth step of developing the photoresist layer to form a resist pattern, and sandblasting the barrier forming material of the opening of the resist pattern The method is characterized by including a fifth step of removing by processing, a sixth step of peeling off the resist remaining on the barrier forming material, and a seventh step of sintering the barrier forming material by firing. The second
The step and the third step may be interchanged.

The transfer sheet used in the second method is prepared by applying an inked barrier forming material on the photoresist layer formed on the base film to form the barrier forming layer. . The barrier forming material and its coating method may be the same as described above. Further, for the same reason as described above, it is desirable to leave the volatile substance in the barrier forming layer. By leaving the volatile substance in this way, a barrier forming layer is formed on the base film on which the photoresist layer is formed, and after drying, the base film is peeled off in a state containing the volatile substance, It is also possible to bond the photoresist layer and the barrier forming layer onto the glass substrate. In this way, the base film can be reused.

The base film has a thickness of 7% in order to prevent wrinkling during the process of applying and drying the barrier forming material.
The thickness is preferably 0 μm or more. As the photoresist, both positive type and negative type can be used.
In order to prevent the resist from being damaged during the coating process of the barrier forming material and the barrier forming material from being damaged at the time of developing the resist, a water developing type or alkaline aqueous solution type resist is also used in the second method. It is preferably used. The resist peeling after sandblasting is performed in the same manner as in the case of the first method.

[0018]

In the first barrier forming method, after the barrier forming layer is transferred from the transfer sheet onto the glass substrate, or the base film is peeled off from the transfer sheet and only the barrier forming layer is adhered onto the glass substrate. After that, a resist pattern is formed on the barrier forming layer, and sandblasting is performed using the resist pattern as a mask to remove unnecessary portions of the barrier forming layer and form a barrier on the glass substrate.

In the second barrier forming method, after the transfer sheet is laminated on the glass substrate with the barrier forming layer as the inner surface side, or after the base film is peeled from the transfer sheet, the barrier forming layer and the photoresist layer are formed. After adhering to the glass substrate, a photoresist layer is pattern-exposed and developed to form a resist pattern, and sandblasting is performed using the resist pattern as a mask to remove unnecessary portions of the barrier formation layer. A barrier is formed on the glass substrate.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show successive process diagrams of a first barrier forming method according to the present invention. Hereinafter, embodiments will be described with reference to these process diagrams.

In this example, a release-treated PET film (Therapyle # 188, Q-1) made by Toyo Metallizing was used as the base film. Then, an ink for forming a barrier is applied to the release-treated surface thereof with an extrusion coater and dried at 80 ° C. for 15 minutes to form a film having a thickness of 16 on the base film 10 as shown in FIG.
A transfer sheet S having the barrier forming layer 11 of 0 μm was formed. The barrier-forming ink used here is the following composition (% by weight) produced by a bead mill using ceramic beads.

[Composition] Glass frit 46.6 Brown alumina 11.4 Black pigment 20.0 Ethyl cellulose 2.0 Ethyl cellosolve 17.98 Butyl carbitol acetate 2.0 Triphenyl phosphate 0.02

After drying, the transfer sheet S was slit so as to have a width for forming a barrier and wound into a roll. By slitting in this way, the portions where the film thickness at both ends of the barrier forming layer 11 was raised were removed.

On the other hand, as shown in FIG. 1B, a glass substrate 13 having a pattern of electrodes 12 on its upper surface and a dielectric layer (not shown) formed thereon in a thick film is prepared.
An adhesive layer 14 having a film thickness of 1.5 μm was formed on No. 3. The adhesive layer 14 was formed by applying an ethyl cellulose solution prepared by adding a small amount of dioctyl phthalate to ethanol with a gravure roll coater.

Then, the transfer sheet S is cut into a predetermined length, superposed so that the barrier forming layer 11 faces the adhesive layer 14 as shown in FIG. 1 (c), and a 120 ° C. heat roll is used. Then, the base film 10 was peeled off and the barrier forming layer 11 was transferred onto the glass substrate 13 as shown in FIG. Then, as shown in FIG. 1E, a negative type dry film resist (NCP225 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is used as the photoresist 15, and this is formed on the barrier forming layer 11 by using a heat roll at 120 ° C.
Laminated on top.

Then, as shown in FIG. 2A, the line width 80
The line pattern mask 16 having a pitch of 220 μm and a position of 220 μm was aligned and exposed with ultraviolet rays. The exposure conditions are an intensity of 200 μW / cm ^{2 at} 364 nm and an irradiation amount of 1
It is 20 mJ / cm ² . After exposure, the dry film resist base film was peeled off, and sodium carbonate lwt
% Aqueous solution at a liquid temperature of 30 ° C. for spray development. As a result, a sandblast resist pattern 17 having a line width of 80 μm and a pitch of 220 μm was obtained as shown in FIG. After forming the resist pattern 17, the resist pattern 17 was dried in an oven at 150 ° C. for 20 minutes for the purpose of removing the volatile substances having a high boiling point remaining in the barrier forming layer 11.

Subsequently, as shown in FIG. 2C, the barrier forming material in the opening of the resist pattern 17 was removed by sandblasting. In this case, brown fused alumina # 1000 was used as the abrasive, the distance between the nozzle and the glass substrate 13 was 7 cm, and the blast treatment was performed at a jet pressure of 3 kg / cm ² .

After the blast treatment is completed, the barrier forming layer 1
The resist on 1 was peeled off. Specifically, a 2.0 wt% aqueous solution of sodium hydroxide is used as a stripping solution,
Spray peeling was performed at ℃. After washing with water, 8
It was dried in an oven at 0 ° C for 15 minutes and finally calcined at a peak temperature of 560 ° C. As a result, as shown in FIG. 2D, the line width at the bottom is 50 μm and the height is 12 μm.
0 μm, very uniform height and flat surface barrier 1
8 was obtained.

3 and 4 show successive process diagrams of the second barrier formation method according to the present invention. Hereinafter, embodiments will be described with reference to these process diagrams.

In this embodiment, a dry film resist (Photec PHF-880AFT-5 manufactured by Hitachi Chemical Co., Ltd.) is used as a base film having a photoresist layer formed thereon.
0) was used. Then, after peeling off the cover film of the dry film resist, as shown in FIG. 3, a barrier forming ink is applied on the photoresist layer 21 on the base film 20 by an extrusion coater, and then at 80 ° C. Dry for 15 minutes at a film thickness of 160 μm
The barrier formation layer 22 of No. 1 was formed. The barrier-forming ink used here is the same as that used in the previous examples. As a result, a transfer sheet S ′ including the photoresist layer 21 and the barrier forming layer 22 on the base film 20 was obtained. After being dried, the transfer sheet S ′ has a width to form a barrier.
Was slit and wound into a roll. By slitting in this way, the portions where the film thickness on both ends of the barrier forming layer 22 is raised were removed.

On the other hand, as in the case of the above embodiment, FIG.
As shown in (b), a glass substrate 2 having a pattern of electrodes 23 on its upper surface and a dielectric layer (not shown) formed thereon as a thick film.
4 was prepared, and an adhesive layer 25 having a film thickness of 1.5 μm was formed on the glass substrate 24. Then, the transfer sheet S ′ is cut into a predetermined length, and the barrier forming layer 23 and the adhesive layer 25 are overlapped so as to face each other as shown in FIG. 3C, and the transfer sheet S ′ is laminated by using a heat roll at 120 ° C. did.

Then, as shown in FIG.
Line pattern mask 26 with a pitch of 0 μm and a pitch of 220 μm
Was aligned and exposed by ultraviolet rays. The exposure conditions are the same as in the previous embodiment. After the exposure, the base film 20 of the dry film resist was peeled off, and a spray phenomenon was performed with a 1 wt% aqueous solution of sodium carbonate at a liquid temperature of 30 ° C. As a result, as shown in FIG.
A sandblast resist pattern 27 having a pitch of 220 μm and a pitch of 220 μm was obtained. After forming the resist pattern 27, it was dried in an oven at 150 ° C. for 20 minutes for the purpose of removing the solvent and the plasticizer remaining in the barrier forming layer 23, as in the previous embodiment.

Subsequently, as shown in FIG. 4C, the barrier forming material in the opening of the resist pattern 27 was removed by sandblasting. The blast conditions are the same as in the previous embodiment.

After the blast treatment was completed, the resist on the barrier forming layer 23 was peeled off in the same manner as in the previous embodiment.
Then, as in the previous example, the sample was washed with water, dried, and then baked at a peak temperature of 560 ° C. As a result, as shown in FIG. 4D, the line width at the bottom is 50 μm.
An extremely uniform and flat surface barrier 28 of m, height 120 μm was obtained.

[0035]

As described above, according to the barrier forming method of the present invention, the following effects and advantages can be obtained.

Since the barrier forming layer is formed by applying the ink-forming barrier forming material on the base film or the base film on which the photoresist layer is laminated, it is necessary to form the barrier forming layer using existing coating equipment. You can Further, since the film can be wound around the backup roll with high accuracy and applied, the barrier forming layer can be formed with a uniform film thickness.

The barrier forming material is applied on the base film or on the base film having a photoresist layer laminated thereon in a width wider than the necessary width, and unnecessary portions of the film are slit to be used, whereby Since there is no undulation, a barrier formation layer with a uniform film thickness can be formed up to the edge, and since the barrier formation layer can be provided only in the necessary area, the alignment mark necessary for aligning the mask during resist exposure can be provided. You can choose not to hide it.

Since the barrier forming layer is formed by applying the ink-formed barrier forming material on the film and transferring it to the glass substrate, the lower surface side of the applied barrier forming material is inverted and becomes the upper surface of the barrier. It is possible to form a barrier with extremely small surface irregularities.

[Brief description of drawings]

FIG. 1 is a first half process diagram showing a first barrier formation method according to the present invention.

FIG. 2 is a process diagram of the latter half of FIG.

FIG. 3 is a first half process chart showing a second barrier formation method according to the present invention.

FIG. 4 is a process chart of the latter half of FIG.

[Explanation of symbols]

 S Transfer sheet 10 Base film 11 Barrier forming layer 12 Electrode 13 Glass substrate 14 Adhesive layer 15 Photoresist 16 Line pattern mask 17 Resist pattern 18 Barrier S ′ Transfer sheet 20 Base film 21 Photoresist layer 22 Barrier forming layer 23 Electrode 24 Glass Substrate 25 Adhesive Layer 26 Line Pattern Mask 27 Resist Pattern 28 Barrier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Shiozaki 1-1-1, Tanikaga-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd.

Claims (9)

[Claims] 1. A first step of transferring a barrier forming layer from a transfer sheet having a barrier forming layer on a base film onto a glass substrate, and a second step of forming a resist pattern on the upper surface of the transferred barrier forming layer. A third step of removing the barrier forming material in the opening of the resist pattern by sandblasting, a fourth step of removing the resist remaining on the barrier forming material, and a fifth step of sintering the barrier forming material by firing. A method of forming a barrier in a plasma display panel, comprising: 2. The method for forming a barrier according to claim 1, wherein
A method of forming a barrier of a plasma display panel, which comprises performing a step of peeling a base film from a transfer sheet and laminating only a barrier forming layer on a glass substrate instead of the first step. 3. A transfer sheet comprising a base film and an ink-forming barrier forming material applied on the base film to form a barrier forming layer. 4. The transfer sheet according to claim 3, wherein a volatile substance remains in the barrier forming layer. 5. A first step of laminating a transfer sheet having a photoresist layer and a barrier forming layer on a base film on a glass substrate with the barrier forming layer as an inner surface side, a second step of peeling the base film, and a photo. Third step of pattern-exposing the resist layer, fourth step of developing the photoresist layer to form a resist pattern, fifth step of removing the barrier forming material at the opening of the resist pattern by sandblasting, on the barrier forming material The sixth step of removing the remaining resist, and the seventh step of sintering the barrier forming material by firing.
A method of forming a barrier in a plasma display panel, comprising: 6. The method for forming a barrier according to claim 5, wherein
A method of forming a barrier of a plasma display panel, wherein the second step and the third step are replaced with each other. 7. The method for forming a barrier according to claim 5, wherein
In place of the first step and the second step, a step of peeling the base film from the transfer sheet and adhering only the barrier forming layer and the photoresist layer onto the glass substrate is performed. Forming method. 8. A transfer sheet comprising a photoresist forming layer formed on a base film and an ink-forming barrier forming material applied on the photoresist layer to form a barrier forming layer. 9. The transfer sheet according to claim 8, wherein a volatile substance remains in the barrier forming layer.