JPH05188380A - Production of liquid crystal panel - Google Patents

Abstract

PURPOSE:To lessen the build-up of printing end parts so as to uniformalize a gap when a cell is formed and to prevent the film peeling around TFT elements by printing an oriented film by using a plate having 1st and 2nd printing part for an oriented film printing plate. CONSTITUTION:The printing plate 12 for the oriented film is formed of a polybutadiene resin, etc., and conical recesses are formed of a photoresist, etc., on the surface of this plate. The printing plate 12 is formed to the shape provided with the 1st printing part 13 having an area to cover the entire part of a picture element part and a 2nd printing part 14 on the outer side than an element part for supplying a voltage to element electrodes after the upper and lower substrates are made into the cell. Such printing plate 12 is mounted to the printing cylinder of a printing machine. As a result, the height of the marginal zone at the end of the picture element part is decreased and the film peeling around the substrates is overcoated with the oriented film formed in the outer peripheral part and, therefore, the film peeling is prevented from becoming foreign matter in a later process and the liquid crystal panel having high quality is stably supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a display panel using liquid crystal, and more particularly to forming an alignment film in which liquid crystal is aligned in a certain direction.

[0002]

2. Description of the Related Art Conventionally, an alignment film is formed by offset printing. For example, in a printing machine having a structure shown in FIG. 4, as shown in FIG. 5, an alignment film 1 made of polyimide is formed only in an area corresponding to a pixel portion of a liquid crystal panel. Is being printed. This offset printing includes a doctor roll 2, an anilox roller 3 and a plate cylinder 4, a dispenser 5 or the like is used to drop the alignment film material 1, and each roller is rotated to attach the substrate to a printing plate 6 to a substrate. Print to 7.

[0003]

However, in the alignment film obtained in the above-mentioned conventional example, as shown in FIG. 6, printed end portions (hereinafter referred to as marginal zones) 8a, 8b, 8 are formed.
There is a phenomenon that c and 8d rise, and a gap defect may occur when the upper and lower substrates are bonded together. Therefore, the printing conditions are optimized to adjust the height of the marginal zone. Specifically, adjustment is performed by the amount of pressing of the printing plate 6 and the substrate 7, the printing speed, and the like. But,
When used for a long period of time, it is difficult to stabilize the quality because the height of the marginal zone changes due to rattling or vibration of the device.

In the active matrix type TFT element substrate 10 in which a transistor is formed in each pixel, film formation of SiO 2, Al, Cr, ITO or the like is repeated to expose and etch a predetermined shape. And the like to form the element 11. In that case, all films are formed and accumulated on the outer peripheral portion of the display screen as shown in the figure. Since this outer peripheral portion is particularly around the substrate, film formation, exposure, and etching are not uniform and unstable. Therefore, film peeling occurs due to thermal shock in a post-process such as panel assembly after completion of element formation, and the film peeling becomes foreign matter and deteriorates the quality.

[0005]

In order to solve the above problems, a method of manufacturing a liquid crystal panel according to the present invention is a polyimide organic film in which electrodes are formed on opposite substrates and liquid crystals are aligned on the substrates and the electrodes. A liquid crystal panel is formed having an alignment film made of a material, and the alignment film forming part is provided at a predetermined interval between the pixel part and an outer peripheral part other than the pixel part.

[0006]

According to the above means, the height of the marginal zone at the end of the pixel portion is reduced, and the film peeling around the substrate is overcoated with the alignment film formed on the outer peripheral portion. A high quality liquid crystal panel can be stably supplied without becoming a foreign substance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Printing plate 1 having an alignment film used in this embodiment
The configuration of No. 2 is shown in FIG. The printing plate 12 includes a first printing unit 13
And a second printing unit 14 is provided. Using this printing plate, as shown in FIG. 2, an element substrate 10 and a color filter substrate 15
Then, the alignment film 1 is printed and formed.

First, the printing plate 12 of the alignment film 1 is made of polyputadiene resin or the like, and a conical recess is formed of photoresist or the like on the plate surface. The shape of the printing plate 12 is such that a first printing portion 13 having an area covering the entire pixel portion and a second printing portion 16 are provided outside the terminal portion for converting the upper and lower substrates into cells and supplying a voltage to the element electrodes. It has a curved shape. This printing plate 14 is attached to the plate cylinder 4 of the printing machine shown in FIG.

Next, the alignment film 1 is formed on the anilox roll 3.
Is dropped from the dispenser 5, and each roll is rotated to transfer it onto the printing plate. For the alignment film 1, a polyamic acid solution or the like is used. The alignment film 1 transferred onto the printing plate 14 is sequentially placed on the upper and lower substrates, that is, the TFT element substrate 10 and the color filter substrate 15, and printed on the substrate. The thickness of this alignment film is 400Å to 2000Å. However, the printing plate 14 vibrates when it comes into contact with the substrates 10 and 15.
This vibration is absorbed by the width of the second printing unit 14, and when the first printing unit 13 contacts the substrate, stable printing without vibration can be performed. After that, the alignment film 1 is provisionally cured at 70 ° C., and finally cured at a high temperature of 200 ° C. At this time, the accumulated forming film 16 remaining around the element substrate 10 is peeled off due to thermal stress or the like.
Since it is overcoated with, it prevents peeling. Therefore, the fully cured substrate is made into cells through the sealing material 17 and the spacer material 18 through the rubbing process.

In the second embodiment, when the height of the remaining formed film 16 around the element substrate 10 is high, or when the impact at the time of contact between the printing plate 14 and the substrate is reduced and vibration is further reduced, The effect can be improved by making the height of the second printing portion 14 lower than the height of the first printing portion 13 of the printing plate.

Further, in the third embodiment, the same effect can be obtained by forming the end portion of the second printing portion 14 of the printing plate in a tapered shape as shown in FIG.

[0013]

As described above, according to the present invention, by providing the alignment film printing plate with the first and second printing portions, the film pressure height at the edge of the alignment film can be reduced and the peripheral portion of the element substrate can be reduced. Since the film peeling can be suppressed, it is possible to easily supply a high quality liquid crystal panel with a uniform gap and no foreign matter.

[Brief description of drawings]

FIG. 1A is a front view of a printing plate used in an embodiment of the present invention, and FIG. 1B is a side sectional view of the printing plate.

FIG. 2 is a sectional view of a liquid crystal panel manufactured according to the same example.

FIG. 3A is a front view of another printing plate usable in the embodiment, and FIG. 3B is a cross-sectional view of the lower surface of the printing plate.

FIG. 4 is a block diagram of a printing machine for an alignment film.

FIG. 5A is a front view of a printing plate used in a conventional example, and FIG. 5B is a side sectional view of the printing plate.

6A is a front view of a substrate showing a printed state of an alignment film of a conventional example, FIG. 6B is a side sectional view of the substrate, and FIG. 6C is a sectional view of a lower surface of the same substrate.

[Explanation of symbols]

 1 Alignment Film 2 Doctor Roll 3 Anilox Roll 4 Plate Cylinder 8a, 8b, 8c, 8d Marginal Zone 10 Element Substrate 12 Printing Plate 13 First Printing Section 14 Second Printing Section 15 Color Filter Substrate

Claims (3)

[Claims] 1. An electrode is formed on opposite substrates, and an alignment film made of a polyimide organic material for aligning liquid crystal is provided on the substrate and the electrode, and the alignment film is formed on a pixel portion and an outer periphery other than the pixel portion. A method for manufacturing a liquid crystal panel, characterized in that the parts are formed with a predetermined gap. 2. The method for manufacturing a liquid crystal panel according to claim 1, wherein the alignment film thickness at the outer peripheral portion is lower than that at the pixel portion. 3. The method of manufacturing a liquid crystal panel according to claim 1, wherein a taper is provided at an end portion of the alignment film on the outer peripheral portion.