JPH10268287A - Electrode plate for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain high-level smoothness of a display surface and to eliminate the need to use an expensive glass substrate as a counter substrate by setting a photosetting adhesive layer by irradiation with light from the transparent substrate side of the electrode plate. SOLUTION: On the electrode surface having a thin film transistor and a counter electrode for driving liquid crystal, a multicolor color layer 11 is formed in a display area across the transparent photosetting adhesive layer 10, and a light shield layer 12 is formed in a TFT area and an electrode area. The color filter layer 11 and light shield layer 12 are formed by pressing a transfer sheet consisting basically of a transfer base, a peeling layer, a smoothing layer, the color filter layer 11, and the light shield layer 12 against the electrode plate for the liquid crystal display device which is applied with a photosetting adhesive on it. In the pressed state, the reverse surface, i.e., the side of the transparent substrate 1 is irradiated with active light to set the photosetting adhesive. A heat treatment for completely setting the photosetting adhesive is performed as necessary and the transfer sheet is peeled off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor (hereinafter referred to simply as "T-film") of a planar switching type (In-Plane-Switching; hereinafter simply referred to as IPS).
The present invention relates to an electrode plate for a liquid crystal display device which is used for displaying a color of a drive type liquid crystal display device (hereinafter referred to as FT).

[0002]

2. Description of the Related Art Conventionally, in order to color a display device, three primary colors of red (R), green (G) and blue (B) are finely arranged in a stripe or matrix on a transparent substrate such as glass. Color filters have been used. In the initial stage, a dyeable resin film is provided on a transparent substrate in a pattern, and this is dyed with a dye having a predetermined spectral characteristic to form a color filter layer. (G),
A predetermined number of colors such as blue (B) are repeatedly formed to form a color filter. However, the color filter of the dyeing type has a drawback that the patterning step of the dyeable resin film and the dyeing step are separate steps, and the anti-staining treatment is also required after the dyeing, which makes the steps complicated and difficult to automate. there were.

On the other hand, in recent years, a colorant such as a pigment has been mixed and dispersed in a resin itself to be a filter layer, and the resin itself has also been made into a photosensitive resin, thereby simplifying the process of producing a color filter. succeeded in. In this method, a photosensitive resin in which a colorant is mixed and dispersed is applied to a transparent substrate such as glass to a uniform thickness, pattern-exposed by an exposure device, and the solubility in a solvent between a light-irradiated portion and a non-irradiated portion is determined. Make a difference. Next, a color filter layer having a desired pattern is formed by selective dissolution called development. According to this method, the process is simpler than the dyeing method, and there is an advantage that a color filter can be created on an automated production line. However, this method is still the same as repeatedly forming a predetermined number of colors such as red (R), green (G), and blue ((B)) on a transparent substrate such as glass, and the process is complicated.

[0004] In order to depart from the complicated steps described above, the present inventors have in the past used a transfer sheet using a metal sheet having a thermal expansion coefficient substantially equal to that of a transparent glass substrate used for a color filter as a base. Has proposed a method of manufacturing a color filter that simplifies the manufacturing process. According to this manufacturing method, the step of repeatedly forming a predetermined number of colors such as red (R), green (G), and blue (B) is performed not on a transparent substrate such as glass but on a base of a transfer sheet. Separately. Therefore, a complicated color filter manufacturing process can be performed in a process separate from the manufacturing line of a transparent substrate such as glass, that is, a liquid crystal display device, which is preferable in terms of production efficiency.

On the other hand, recently, a counter electrode is also provided on an electrode plate having a TFT and a drive electrode, which is called an IPS, and by applying an electric field substantially parallel to the liquid crystal molecules, the gradation control of the transmitted light by the liquid crystal is performed. A driving method has been proposed. This IPS
The method overcomes the drawbacks of the conventional liquid crystal display device in that the viewing angle is wide. Furthermore, in the IPS system, since the drive electrode and the counter electrode are on the same substrate,
The opposing substrate has the simplicity that a plate-like object merely forming a liquid crystal display cell may be used.

However, when a liquid crystal display device performs color display, it is necessary to provide a color filter as described above. In that case, it is conceivable to form the color filter on the counter substrate side. However, if a color filter is to be formed on the counter substrate side, the counter substrate must use an expensive glass plate like the drive electrode plate, and in the manufacturing process, the drive electrode plate and the counter substrate require high precision. Must face each other. Furthermore, when a plurality of drive electrode plates are multi-faced on a large glass substrate and a color filter is also multi-faced on a counter substrate, the yield of the color filter synergistically deteriorates the yield of the liquid crystal display device. . Furthermore, in the IPS system, a high degree of smoothness is required on the surface where the sealed liquid crystal and the liquid crystal cell are in contact in order not to distort the alignment of the liquid crystal molecules. When a color filter layer or a light shielding layer is formed, there is a certain difficulty in maintaining a high degree of smoothness on the display surface.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional liquid crystal display device, realizes a high degree of smoothness on the liquid crystal display surface, and uses an expensive glass substrate as the counter substrate. An object of the present invention is to provide a structure of an electrode plate for a liquid crystal display device which does not need to be used, and which is inexpensive and contributes to an improvement in yield.

[0008]

That is, the present invention relates to an electrode plate for a TFT liquid crystal display device of a flat switching system, which is provided in a display area via a photocurable adhesive layer provided on the surface of the electrode plate. A color filter layer of a plurality of colors for color display transferred and peeled from the transfer sheet is formed,
In the TFT region and the wiring region, a light-shielding layer is formed, which is peeled and transferred from the transfer sheet simultaneously with the color filter layer, and the photo-curable adhesive layer is irradiated with light from the transparent substrate side of the electrode plate. An electrode plate for a liquid crystal display device, which is light-cured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing an embodiment of the electrode plate for a liquid crystal display device of the present invention, and there is a layer in which hatching is omitted in consideration of legibility of the drawing. In the figure, a transparent substrate 1 is made of glass, preferably glass having a low coefficient of thermal expansion containing only a small amount or no alkali metal element. Its thickness is, for example, 0.6 to 1.1 mm. Alternatively, although not shown, a thin film transistor may be provided after a chemically stable inorganic barrier layer such as silicon dioxide is formed on the surface of the transparent substrate 1.

A thin film transistor is basically formed by laminating a gate electrode 2, a gate insulating layer 3, and a silicon semiconductor layer 4,
The source electrode 5 and the drain electrode 6 are formed so as to face each other on the silicon semiconductor layer 4. A drive electrode 7 is provided as an extension of the drain electrode 6. The insulating passivation layer 8 is provided to stabilize the characteristics of the thin film transistor. As shown in the drawing, the counter electrode 9 paired with the drive electrode 7 is placed on the same level as the gate electrode 2, which can be said to be a feature of the electrode plate for the liquid crystal display device of the flat switching type.

A color filter layer 11 of a plurality of colors is formed in a display area via a transparent photocurable adhesive layer 10 on the surface of the electrode plate provided with the above-mentioned thin film transistor and a counter electrode for driving a liquid crystal. In the TFT region and the electrode region,
The light shielding layer 12 is formed.

The color filter layer 11 and the light shielding layer 12 in the electrode plate for a liquid crystal display device of the present invention are formed by a transfer method as shown in FIG. That is, in FIG. 2, the transfer sheet 16 basically includes the transfer base 13 and the release layer 1.
4. smoothing layer 15, color filter layer 11, and light shielding layer 1
Consists of two. This transfer sheet 16 is applied to the photocurable adhesive 1
7 is pressed against the upper electrode plate for a liquid crystal display device.

As the pressing means, uniform pressing is performed by an arbitrary method such as a flat plate press and a roll press. In this state, the actinic light 18 is irradiated from the lower surface, that is, the transparent substrate 1 side, to cure the photocurable adhesive 17. If necessary, a heat treatment for completely curing the photocurable adhesive 17 is performed, and the transfer sheet 16 side is peeled off as illustrated. Thus, an electrode plate for a liquid crystal display device having an extremely flat surface reflecting the smooth surface of the release layer 14 can be obtained.

Each layer of the transfer sheet 16 will be described.
The transfer base 13 is made of a continuous metal plate or metal foil.
Thickness is 0.15 mm or less, preferably 0.06 mm
0.09 mm, and the material is the electrode plate
A metal whose thermal expansion coefficient is almost equal to that of the transparent substrate 1 is preferable. L
The glass transparent substrate used for CD has a coefficient of thermal expansion of 40 × 10
^-7/ ° C low expansion coefficient glass
For example, an iron-nickel alloy, for example, a 42 alloy (nickel
42% by weight, balance iron), amber (36% by weight nickel,
Thermal expansion coefficient 10-40 × 10^-7
/ ° C., which is convenient. Iron-nickel alloy
Is suitable in that it hardly rusts in the air and has good storage stability.
You.

The release layer 14 is a polymer film having resistance to an organic solvent. The release layer 14 has an effect of smoothing the surface of the transfer base 13 and an elasticity for maintaining uniform adhesion between the electrode plate and the transfer base 13 during transfer. give. For this purpose, a film thickness of 10
The thickness is preferably from 100 μm to 100 μm. It is preferable that the release layer 14 has flexibility from the viewpoint of transferability. On the other hand, from the original characteristics of the release layer 14, it is desirable that the surface is inert and the film hardness is high.

Specifically, a film obtained by coating and drying casein, polyvinyl alcohol, hydroxyethylcellulose, etc. with a water-soluble resin having organic solvent resistance, and a polyurethane resin and various rubber-based resins as elastic resins may be mentioned. It is not limited to these resins. It is also effective to add a silicone-based or fluorine-based surfactant for the purpose of improving the releasability.
The original function can be realized only when integrated with No. 4.

For the color filter layer 11, a dyeing method, a pigment dispersion method, a printing method and the like can be applied. The dyeing method is to add a dichromate to a dyeable resin such as gelatin, low molecular weight gelatin, glue, casein, etc. to make it a photosensitive resin, pattern-irradiate it with active light, develop it, and then dye it with an anionic dye Then, a red, green and blue color are formed by the same steps as described below. A similar color filter layer 11 can be formed using a dyeable synthetic resin having photosensitivity having a cationic group such as an amide group or an amino group.

In the pigment dispersion method, a color filter layer 11 is formed by repeating the steps of applying, exposing, developing and heating a photosensitive resin in which a pigment having a desired hue is dispersed in advance. The printing method is a method of forming the color filter layer 11 by sequentially printing red, green, and blue inks on a substrate, for example, mainly by lithographic offset or intaglio offset printing.

As shown in FIG. 2, a light-shielding layer 12 is formed between the color filter layers 11. Light shielding layer 12
Are formed at positions where the TFT region and the electrode region can be hidden, and contribute to the improvement of the display contrast of the LCD. The smoothing layer 15 may or may not be provided, but may be provided to impart flatness and chemical stability to the surface of the color filter layer 11.

FIG. 3 shows the electrode plate of the present invention together with the counter substrate 19 as a liquid crystal display cell. It can be seen that the opposing substrate 19 for enclosing the liquid crystal 20 is simply a plate or a film.

[0021]

【Example】

<Example 1> (Step 1) Rolled 42 alloy of 0.11 mm (42% by weight of nickel,
A 90 μm-thick coating film was formed on the (iron) plate in the following manner to obtain a release layer 14. Coating method: Reverse coater Coating liquid: Desmohen 651 (trade name, manufactured by Bayer AG) /
Desmodur N-75 (trade name, manufactured by Bayer AG) was added in a weight ratio of 1.2: 1, and fluorine-based surfactant Florard FC-17 was used.
0.00 (trade name, manufactured by Sumitomo 3M Limited) was added to give a transfer base substrate.

(Step 2) Low-molecular-weight gelatin is dip-coated on the transfer base substrate, pattern-exposed with active light after drying, washed with water, dried at 110 ° C. for 5 minutes, and then dyed with a red acid dye.
They were immersed in a 1% by weight aqueous solution of tannic acid and a 0.5% by weight aqueous tartar solution for 5 minutes at 70 ° C and 5 minutes at 60 ° C, respectively, and then dried at 110 ° C for 5 minutes. Similarly, green, blue and black were subjected to pattern exposure, development and fixing at predetermined positions to form a color filter layer 11 and a light shielding layer 12.

(Step 3) 2 parts by weight of butyl methacrylate, 8 parts by weight of acrylic monomer M-300 (trade name, manufactured by Toagosei Chemical Industry Co., Ltd.), 0.2 of photopolymerization initiator "Ilgaguer 907" (trade name, manufactured by Ciba Geigy) A solution consisting of parts by weight was used as a photo-curing adhesive, which was dropped onto a surface of an electrode plate for a TFT liquid crystal display device of a flat switching type in which a TFT and a counter electrode were formed on a 7059 glass substrate (trade name, manufactured by Corning, USA). And spread over the entire surface.

(Step 4) The transfer sheet 16 formed in the above steps 1 and 2 is pressed against the electrode plate for a liquid crystal display device in which the photo-curable adhesive is spread over the entire surface in the step 3 by two rolls. did. Thereafter, the transfer base 13 was separated by irradiating 100 mJ / cm ² with ultraviolet light from the back surface. The obtained electrode plate for a liquid crystal display device has a smooth color filter surface serving as a display surface,
With the liquid crystal display cell incorporated, distortion of the liquid crystal orientation was small and the screen display was good.

Example 2 (Step 1) A coating film was formed on a 0.08 mm rolled 42 alloy with the following solution and dried at 150 ° C. to obtain a release layer 14 having a thickness of 15 μm. Coating method: Dip coater Coating solution: 12% by weight aqueous solution of polyvinylpyrrolidone (Step 2) A red acrylic pigment-dispersed photosensitive material is applied on the release layer 14 by a reverse coater, dried and then pattern-exposed with active light, and an alkali developer And washed with water and dried at 150 ° C. for 5 minutes. In the same manner, the color filter layer 11 and the light-shielding layer 12 were formed by pattern exposure and development of green, blue and black at predetermined positions. The composition of the acrylic pigment-dispersed photosensitive material is based on the following formulation.

A: 10 parts by weight of pigment The pigment is indicated by a color index (C.I.) number. Breakdown Red: CI red pigment 177 and CI yellow pigment 139 Green: CI green pigment 36 and CI yellow pigment 139 Blue: CI blue pigment 15 Black: CI black pigment 7

B: 10 parts by weight of anionic acrylic copolymer having the following composition 1 part by weight of methacrylic acid 2 parts by weight of methyl methacrylate 2 parts by weight of hydroxyethyl methacrylate 2 parts by weight of butyl methacrylate 3 parts by weight of cyclohexyl acrylate

C: Multifunctional acrylic monomer, Aronix M-300 (trade name, 10 parts by weight, manufactured by Toagosei Chemical Industry Co., Ltd.) D: 0.5 parts by weight of photopolymerization initiator "Irgacure 907" E: 120 parts by weight of organic solvent A photopolymerizable pigment-dispersed photosensitive material obtained by sufficiently mixing and kneading A to E was prepared.

(Step 3) 3 parts by weight of butyl methacrylate, Aronix M-305 (Toagosei Chemical Industry Co., Ltd.)
A solution consisting of 2 parts by weight of Aronix M-400 (trade name of Toagosei Chemical Industry Co., Ltd.) and 0.2 parts by weight of a photopolymerization initiator Irgaguer 907 (trade name of Ciba Geigy Co.) was photocured. Mold adhesive, and use
Nine glass substrates (trade name, manufactured by Corning Incorporated, USA) were dropped on a surface of an electrode plate for a TFT liquid crystal display device of a flat switching type in which a TFT and a counter electrode were formed, and spread over the entire surface.

(Step 4) The same procedure as in step 4 of Example 1 was performed. The obtained electrode plate for a liquid crystal display device had a smooth color filter surface serving as a display surface, and showed good image display with little distortion in the orientation of the liquid crystal when assembled in a liquid crystal display cell.

[0031]

According to the present invention, there is provided an electrode plate for a liquid crystal display device as described above. According to the present invention, the color filter layer and the light-shielding layer formed by the transfer method have the same structure as the release layer of the transfer base. Since the surface is inherited as it is, the surface can realize a high degree of smoothness, and therefore, the quality of the liquid crystal display can be improved. Moreover, since the color filter layer and the light-shielding layer are collectively provided on the side of the TFT electrode plate, an expensive glass substrate need not be used for the opposing substrate, and therefore, the liquid crystal display device is inexpensive and contributes to an improvement in yield. Can be provided.

[0032]

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of an electrode plate for a liquid crystal display device of the present invention.

FIG. 2 is an explanatory diagram showing a process of forming an electrode plate for a liquid crystal display device of the present invention.

FIG. 3 is an explanatory sectional view showing a state in which the electrode plate for a liquid crystal display device of the present invention is incorporated in a liquid crystal display cell.

[Description of Signs] 1 Transparent substrate 2 Gate electrode
3 gate insulating layer 4 silicon semiconductor layer 5 source electrode
6 Drain electrode 7 Drive electrode 8 Passivation layer
9 Counter electrode 10 Photocurable adhesive layer 11 Color filter layer
12 light shielding layer 13 transfer base 14 release layer
15 Smooth layer 16 Transfer sheet 17 Light curable adhesive
18 actinic light 19 counter substrate 20 liquid crystal

Claims (1)

[Claims] 1. A flat switching type electrode plate for a TFT liquid crystal display device, wherein a color transferred by being peeled from a transfer sheet and transferred to a display area via a photocurable adhesive layer provided on the surface of the electrode plate. A color filter layer of a plurality of colors for display is formed, and in the TFT region and the wiring region, a light-shielding layer is formed, which is peeled and transferred from the transfer sheet at the same time as the color filter layer. Is an electrode plate for a liquid crystal display device, which is light-cured by irradiating light from the transparent substrate side of the electrode plate.