JP3646439B2 - Liquid crystal panel and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal panel widely used in a light control device and a display device, and a manufacturing method thereof.
[0002]
[Prior art]
[0003]
The flow of the manufacturing process of the thin film transistor type liquid crystal display device (TFT-LCD), which is the center of the color liquid crystal display device, will be briefly described below.
[0004]
First, alignment films are formed on the TFT substrate and the color filter (CF), respectively. The alignment film is a so-called rubbing process in which after each substrate is washed, a polymer film such as polyimide is usually formed on the substrate by a flexographic printing process and a subsequent curing process, and the film is rubbed in one direction with a cloth such as rayon. This completes the formation.
[0005]
Further, after each substrate is washed, one of the substrates is coated with a sealing material uniformly mixed with a spacer such as glass fiber in a predetermined amount in a predetermined pattern.
[0006]
The sealing material pattern is a rectangle in which a liquid crystal inlet is formed, and a pattern frame having the same width is formed by a screen printing method.
[0007]
Then, the TFT substrate and the color filter substrate are bonded together. The bonding process is a process in which the TFT substrate and the color filter substrate are bonded together with high precision using alignment marks, and then pressure firing is performed to cure the sealing material while maintaining the gap between the substrates. .
[0008]
The subsequent liquid crystal injection step is a step of injecting liquid crystal into the completed empty panel by a vacuum injection method and then sealing the injection port with an adhesive to complete the liquid crystal panel.
[0009]
In the vacuum injection, the injection tank is first brought to a vacuum state of about 10 ⁻³ Torr, and then the empty panel is immersed in the liquid crystal reservoir installed in the tank, and the inside of the tank is gradually leaked to inject the liquid crystal into the empty panel. The principle is the use of capillary action due to pressure difference.
[0010]
Further, the sealing of the injection port is performed by applying a UV curable resin to the injection port and curing the portion by UV irradiation.
[0011]
The above process flow is a TFT-LCD manufacturing process, which is a general manufacturing method of a color liquid crystal display panel.
[0012]
In the process, the bonding via the sealing material is performed by mixing a predetermined amount of a particle spacer made of glass fiber, glass beads or plastic beads having a predetermined particle diameter with the sealing material. By applying and forming on one substrate and pressing and baking the upper and lower substrates, the liquid crystal panel is bonded to have a certain thickness.
[0013]
By the way, when the sealing material in which the particle spacers are dispersed is formed in a predetermined pattern, the particle spacers are relatively expensive, and the commercially available spacers have a limited particle size. It is necessary to design the thickness of the liquid crystal panel in consideration of the particle size, and furthermore, if the spacer is not sufficiently dispersed in the sealing material, the liquid crystal panel cannot secure a uniform thickness and display unevenness, and However, since air is mixed in the dispersion, there is a problem that after the dispersion, it is necessary to leave it for several hours to degas.
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and does not use particle spacers such as expensive glass fibers, and is simple and accurate with a thickness designed within a free range according to the characteristics and driving method of the liquid crystal to be used. An object is to provide an inexpensive and high-quality liquid crystal panel and a method for manufacturing the same.
[0015]
The invention described in claim 1
In the cross-sectional structure of the seal portion around the liquid crystal panel, a sealing material and a resin columnar structure are installed adjacent to each other, and the sealing material connects the resin columnar structure to the liquid crystal layer side and the outside. A method of manufacturing a liquid crystal panel sandwiched from the side,
After the resin columnar structure is formed on the substrate on which the sealing material is not applied and formed and sufficiently cured, it is bonded to the substrate on which the sealing material is applied,
The liquid crystal panel manufacturing method according to claim 1, wherein the resin columnar structure is press-fitted into a sealing material to obtain a seal portion having a cross-sectional structure in which the sealing material sandwiches the resin columnar structure .
[0020]
That is, in the present invention, a columnar structure having a predetermined pattern is formed on one of the upper and lower substrates for a liquid crystal panel and is sufficiently cured to form a spacer, and the sealing material is applied to another substrate in a predetermined pattern. In the cross-sectional structure of the seal portion of the liquid crystal panel by coating and forming the substrates together, the spacer composed of a sealing material and a resin columnar structure is adjacent, and preferably the sealing material is a resin columnar shape. A liquid crystal panel having a structure in which a structure is sandwiched from inside and outside the liquid crystal panel.
[0021]
Further, the resin columnar structure serving as a spacer is a novolac resin or an epoxy acrylate resin that is inactive with respect to the liquid crystal and less likely to lower the insulating property of the liquid crystal due to elution of impurity ions and the like. Such a liquid crystal panel.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
In the case of a liquid crystal panel, a polymer alignment film such as polyimide is provided on each of upper and lower substrates (in the case of a thin film transistor type liquid crystal display device TFT-LCD, an upper substrate: a color filter, and a lower substrate: a TFT substrate) as in the conventional technique. Applying and rubbing it in one direction with a fiber cloth such as rayon, an alignment treatment step, a step of bonding the upper and lower substrates through a sealing material in which particle spacers are dispersed, It is manufactured by injecting liquid crystal into the panel and sealing it.
[0023]
In the case of the present invention, in the bonding step, instead of using a particle-based spacer, a resin columnar structure 10 formed by patterning and curing is used. Control of the thickness of the panel, which has been limited by the type, can be more easily performed.
[0024]
Furthermore, when the resin columnar structure 10 is a photoresist, a columnar structure having a predetermined width can be formed with higher accuracy by a photofabrication process.
[0025]
In addition, the width | variety of the columnar structure 10 is smaller than the width | variety of the sealing material 11, and needs to fully play the role as a spacer, About 0.05-0.1 mm is preferable.
[0026]
Furthermore, the thickness of the columnar structure 10 can be controlled in a free range depending on the coating resin conditions of the photoresist to be used and the coating conditions such as the rotational speed of the spin coating method.
[0027]
In addition, the thickness of the columnar structure 10 is preferably about 1 to 10 μm in consideration of the thickness of a panel for a normal TFT-LCD or a ferroelectric LCD.
[0028]
As described above, according to the present invention, an inexpensive and high-quality color liquid crystal display panel can be realized.
[0029]
The photoresist used for forming the resin structure 10 according to the present invention should have a voltage holding ratio of 99% or more at room temperature without leaching impurity ions or the like to contaminate the liquid crystal layer 6. Suitable as the resin are novolak resins (for example, positive photoresist MP1400 manufactured by Shipley Co., Ltd .; curing temperature 170 ° C.) and epoxy acrylate resins (for example, negative photoresist TLC- manufactured by Okuno Pharmaceutical Co., Ltd.). 2551; curing temperature 220 ° C.).
[0030]
【Example】
Examples of the present invention will be described below.
[0031]
First, a TFT substrate 8 and a color filter substrate (pigment dispersion type) were prepared, and ultrasonically cleaned while being immersed for several minutes in the order of acetone, ethanol, and pure water.
[0032]
Next, a polyimide film (LQ-T120 manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 0.1 μm was formed on the substrates 1 and 8.
[0033]
Subsequently, the alignment films 5 were formed on the respective substrates 1 and 8 by rubbing in predetermined directions.
[0034]
Next, the same cleaning as the previous cleaning is performed, and a sealing material 11 (Struct Bond XN-21-S manufactured by Mitsui Toatsu Chemical Co., Ltd.) is applied on the TFT substrate 8 by a screen printing method using a predetermined plate pattern. On the other hand, a photoresist (TLC-2551 manufactured by Okuno Seiyaku Kogyo Co., Ltd.) is applied on the color filter substrate 1 by a spin coat method, and is exposed and developed using a predetermined mask. By baking and curing, the columnar structure 10 made of a resist resin having the same pattern shape as the pattern of the sealing material 11 and having a width of about 1/3, 0.1 mm, and a thickness of 4.5 μm was formed.
[0035]
Then, the color filter substrate 1 and the TFT substrate 8 were aligned and overlapped, and baked in an oven at 220 ° C. for 1 hour while applying pressure using a predetermined jig.
[0036]
As a result, the resin columnar structure 10 was press-fitted into the sealing material 11 to obtain the seal portion 2 having a cross-sectional structure in which the sealing material is sandwiched between the columnar structures (see FIGS. 1 and 2).
[0037]
Then, after slow cooling, the resulting empty panel was taken out, liquid crystal (ZLI-4792 manufactured by Merck) was vacuum-injected, and then the injection port was sealed with a sealant (DNM-2110 manufactured by Nippon Denki Co., Ltd.). A good color liquid crystal panel which was uniformly controlled at 5 μm and had no display unevenness was completed.
[0038]
【The invention's effect】
As described above, the periphery of the liquid crystal panel can be obtained by bonding together a substrate that forms a columnar structure with a predetermined pattern of resin and is cured to form a spacer and a substrate on which a sealing material is applied and formed in a predetermined pattern. In the seal section cross-sectional structure, a spacer made of a sealing material and a resin columnar structure is installed adjacently, and preferably the sealing material sandwiches the resin columnar structure from the liquid crystal layer side and the outside side in contact with air. By providing a liquid crystal panel having the structure described above, an inexpensive and high-quality liquid crystal panel that can accurately control the thickness of the liquid crystal panel within a simple and free range without using a particulate spacer is provided. I can do it.
In addition, by using a novolac resin or an epoxy acrylate resin as the spacer resin, it is possible to eliminate a decrease in the insulating properties of the liquid crystal layer due to elution of impurity ions and the like.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a surface structure of the present invention.
FIG. 2 is an explanatory view showing a cross-sectional structure of the present invention.
FIG. 3 is an enlarged cross-sectional view of a seal portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Color filter substrate 2 ... Seal part 3 ... Liquid crystal injection port 4 ... Color filter substrate electrode 5 ... Orientation film 6 ... Liquid crystal layer 7 ... TFT substrate electrode 8 ... TFT substrate 10 ... Resin Columnar structure 11 ... Sealing material

Claims (1)

In the cross-sectional structure of the seal portion around the liquid crystal panel, a sealing material and a resin columnar structure are installed adjacent to each other, and the sealing material connects the resin columnar structure to the liquid crystal layer side and the outside. A method of manufacturing a liquid crystal panel sandwiched from the side ,
After the resin columnar structure is formed on the substrate on which the sealing material is not applied and formed and sufficiently cured, it is bonded to the substrate on which the sealing material is applied,
A method for manufacturing a liquid crystal panel, wherein the resin columnar structure is press-fitted into a sealing material to obtain a sealing portion having a cross-sectional structure in which the sealing material sandwiches the resin columnar structure.

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