JPH1090689A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible keeping a gap size uniform and improving appearance by providing an organic film with thickness nearly equal to a gap size and for uniformly controlling a gap on a non-display part of an external side of a seal and constituting so that a spacer isn't provided on a display part of an inner side of the seal. SOLUTION: This panel is constituted so that the organic films 17 with the thickness nearly equal to the gap size of a liquid crystal display panel are provided uniformly on the non-display part of the outside of the seal 20, and further, the spacer isn't provided on the display part of the inside of the seal 20. Then, a first substrate 11 is overlapped a second substrate 12, and the seal 20 is cured in the state that the seal 20 isn't overlapped the organic film 17 provided on the non-display part. Further, the organic films 17 are provided uniformly on the non-display part, and are stuck to the first substrate 11 and second substrate 12 without gap at the thickness nearly equal to the gap size. Thus, when the seal 20 is cured, the gap of the liquid crystal display panel is controlled uniformly even without spacer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a liquid crystal display panel in which a plurality of liquid crystal display panels are obtained after a first substrate and a second substrate are overlaid. More specifically, the gap between the first substrate and the second substrate is kept uniform,
The present invention relates to a structure of a liquid crystal display panel characterized by improving the appearance of the liquid crystal display panel. The present invention is applicable to all liquid crystal display panels regardless of the presence or absence of a color filter and a driving method.

[0002]

2. Description of the Related Art In a conventional liquid crystal display panel, a plurality of liquid crystal display panels are formed on a large substrate in consideration of mass productivity. Hereinafter, the prior art will be described with reference to FIGS. 3 and 4 taking a monochrome liquid crystal display panel as an example. FIG. 3 is a plan view showing a conventional liquid crystal display panel, and FIG. 4 is a sectional view showing a conventional liquid crystal display panel.

As shown in FIGS. 3 and 4, a prior art monochrome liquid crystal display panel comprises a first substrate 11 and a second substrate 12.
A first display electrode 13 made of indium tin oxide (hereinafter, referred to as ITO) and a second display electrode 13 for displaying images;
And the display electrode 14 are provided. In addition, composed of ITO,
First alignment marks 15 and second alignment marks 16 necessary for alignment between the first substrate 11 and the second substrate 12 are provided at four corners of the large substrate.

Further, on the upper surfaces of the first display electrode 13 and the second display electrode 14, there are provided a first alignment film 18 and a second alignment film 19 for aligning the liquid crystal 22. Furthermore, a spacer 21 for maintaining a gap between the first substrate 11 and the second substrate 12 at a predetermined size, a spacer 21 for maintaining the gap at a predetermined size, and the liquid crystal 22 with the first substrate 1
Seal 20 for sealing between first and second substrates 12
And Further, the first substrate 11 and the second substrate 12
And a liquid crystal 22 for display.

[0005] Here, an area formed by the first display electrode 13 and the second display electrode 14 inside the seal 20 is called a display section 23, and an area outside the display section 23 is a non-display section 24. I will call it.

Next, a manufacturing method for obtaining the above structure will be described. Washed first substrate 11 and second substrate 1
2, ITO was sputtered to 200
It is formed with a thickness of nm. After that, an exposure process and a development process are performed using a predetermined photomask, and the first display electrode 13, the second display electrode 14, the first substrate 11, and the second substrate 12 are etched by an etching process. First alignment marks 15 and second alignment marks 16 required for alignment are formed.

After that, the first substrate 11 and the second substrate 12
And the first display electrode 13 inside the seal 20
A first alignment film 18 and a second alignment film 19 made of a polyimide resin are provided on a display portion 23 composed of the first display film 14 and the second display electrode 14.
Is formed by a printing method, and heat treatment is performed using a clean oven. After that, the first substrate 11 and the second substrate 1
The surface of No. 2 is rubbed with a roll wrapped with a cotton cloth by a rubbing method to perform orientation treatment.

Then, a seal 2 is prepared by mixing a thermosetting epoxy resin with a glass fiber corresponding to a predetermined gap.
0 is formed around the display section 23 of the first substrate 11 by a screen printing method.

Further, a spacer 21 is formed by dispersing a solution in which plastic beads matching a predetermined gap size are dispersed in a mixed solution of alcohol and pure water, on the second substrate 12.

[0010] Thereafter, the first substrate 11 and the second substrate 12 are superimposed on each other by using the first alignment mark 15 and the second alignment mark 16 for positioning. Further, fine adjustment of the alignment between the first alignment mark 15 and the second alignment mark 16 is performed using a binocular microscope, and the first substrate 11 and the second substrate 12 are overlapped. At this time, a plurality of points around the superposed first substrate 11 and second substrate 12 are fixed with an ultraviolet curing adhesive.

Thereafter, the first substrate 11 and the second substrate 12 thus superimposed are set on a seal hardening jig,
Heat treatment is performed in a firing furnace while applying pressure at a predetermined pressure to cure the seal 20.

As a result, the first substrate 11 and the second substrate 1
The liquid crystal 22 is not injected into the gap inside the seal 20 with the liquid crystal panel 2, and a plurality of liquid crystal display panels are formed by connecting a plurality of liquid crystal display panels.

Thereafter, the first substrate 11 and the second substrate 12 having the cured seal 20 are subjected to a scribing process and a breaking process to obtain a liquid crystal display panel which is divided into a plurality. Further thereafter, the first substrate 11 and the second substrate 1
The liquid crystal 22 is injected into a gap inside the seal 20 with the liquid crystal 22.
As a result, a monochrome liquid crystal display panel can be formed.

[0014]

The gap between the first substrate 11 and the second substrate 12 of the liquid crystal display panel is as follows.
As described above, control is performed by the seal 20 and the spacer 21. However, gaps often do not become uniform within individual panels or among a plurality of panels due to variations in the distribution of the spacers 21 and pressurizing conditions at the time of curing the seal. Causing quality problems. Particularly in the case of a super-twisted nematic (STN) liquid crystal panel, strict gap accuracy is required because gap unevenness occurs due to a slight gap difference. When a large amount of the spacers 21 are sprayed on the display unit 23 for the purpose of uniform control of the gap, the liquid crystal display panel causes a decrease in contrast, and furthermore, a rough feeling is generated, and the appearance is deteriorated.

An object of the present invention is to solve the above-mentioned problems and to provide a structure of a liquid crystal display panel capable of maintaining a uniform gap size and improving the appearance of the liquid crystal display panel.

[0016]

In order to achieve the above object, a liquid crystal display panel of the present invention employs the following structure.

In the liquid crystal display panel according to the present invention, a non-display portion outside the seal is provided with an organic film for uniformly controlling the gap with a thickness substantially equal to the gap size, and a display portion inside the seal is provided on the non-display portion. In order to improve the appearance of the liquid crystal display panel, no spacer is provided.

In the liquid crystal display panel of the present invention, an organic film having a thickness substantially equal to the gap dimension is evenly provided on the non-display portion outside the seal. For this reason, even if the pressurizing condition at the time of curing the seal is slightly changed, the gap in each panel and between the plurality of liquid crystal display panels can be controlled uniformly. Therefore, partial coloring due to gap unevenness can be prevented.

Further, in the liquid crystal display panel of the present invention, no spacer is provided on the display portion inside the seal. For this reason, it is possible to prevent a decrease in contrast due to the spacer, and furthermore, it is possible to eliminate a rough feeling of the display unit,
A clear display can be obtained and the appearance can be improved.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a liquid crystal display panel according to an embodiment of the present invention. In the following description of the embodiment, a monochrome liquid crystal display panel will be described as an example.

FIG. 1 is a cross-sectional view showing a liquid crystal display panel according to an embodiment of the present invention in which a first substrate and a second substrate are superimposed, and is a cross section taken along line AA in the plan view of FIG. FIG. FIG. 2 is a cross-sectional view showing the liquid crystal display panel according to the embodiment of the present invention in which the display electrodes of the first substrate in the non-display portion outside the seal of FIG. 1 are exposed. Hereinafter, description will be made with reference to FIG. 1, FIG. 2, and FIG. 3 alternately.

The black-and-white liquid crystal display panel of the present invention comprises a first substrate 11 and a second substrate 12 made of ITO, and a first display electrode 13 and a second display electrode 14 for displaying images.
Are provided. Further, the first substrate 11 is made of ITO.
A first alignment mark 15 having a male cross shape and a second alignment mark 16 having a female cross shape are provided, which have a role of performing alignment between the first alignment mark 15 and the second substrate 12.

Further, the organic film 17 having a thickness substantially equal to the gap between the first substrate 11 and the second substrate 12 constituting the liquid crystal display panel is covered with the non-display portion 24 which is an area outside the seal 20. To be provided. The organic film 17 has photosensitivity and is uniformly provided on the non-display portion 24 outside the seal 20 by patterning as shown in FIG. 3, so that a gap between the first substrate 11 and the second substrate 12 is formed. Has the role of keeping dimensions constant. The organic film 17 is required to have at least heat resistance, water resistance, and chemical resistance during the liquid crystal display panel manufacturing process.

Further, a first alignment film 18 and a second alignment film 19 provided on the upper surface of the first display electrode 13 and the second display electrode 14 for aligning the liquid crystal 22 are formed on the first display electrode 13 and the second display electrode 14, respectively. The first substrate 11 and the second substrate 12 are provided.

In addition, the first substrate 11 and the second substrate 1
A seal 20 for keeping the gap between the first and second substrates 2 at a predetermined size and for sealing the liquid crystal 22 between the first substrate 11 and the second substrate 12 is formed outside the display unit 23.

Further, the first substrate 11 and the second substrate 12
And a liquid crystal 22 for performing display between them.

In the present invention, the organic film 17 having a thickness substantially equal to the gap size of the liquid crystal display panel is covered with the seal 20.
Are provided evenly in the non-display section 24 outside the. The organic film 17 needs to have an accuracy that does not overlap with the seal 20 in order to prevent a gap defect. And the first
The substrate 11 and the second substrate 12 are overlapped with each other, and the seal 2
The seal 20 is cured in a state where the 0 and the organic film 17 provided on the non-display section 24 do not overlap.

The organic film 17 is provided evenly on the non-display portion 24 and closely adheres to the first substrate 11 and the second substrate 12 with no gap and a thickness substantially equal to the gap size. For this reason, when the seal 20 is cured, the gap of the liquid crystal display panel can be uniformly controlled without the spacer 21.

Further, in the present invention, since there is no spacer 21 in the display portion 23 inside the seal 20, a decrease in contrast can be prevented, and the display portion 2 caused by the spacer can be prevented.
The rough feeling of No. 3 is eliminated, and a clear display is obtained, which is useful for improving the display quality of the liquid crystal display panel.

In the liquid crystal display panel of the present invention, the organic film 17
Are uniformly provided on the non-display portion 24 outside the seal 20. If it is desired that the first display electrode 13 is exposed for the purpose of mounting, the second liquid after the liquid crystal 22 is injected as shown in FIG. Unnecessary portions of the substrate 12 and the organic film 17 may be removed by scribing and breaking. When it is desired that the second display electrode 14 is exposed, similar processing may be performed on unnecessary portions of the first substrate 11 and the organic film 17.

Next, a manufacturing method for obtaining the above structure will be described with reference to FIGS. 1, 2 and 3 alternately. First, the first substrate 11 and the second
ITO on the substrate 12 by sputtering
Each is formed with a thickness of 00 nm.

Thereafter, a photoresist is formed on the entire surface,
Further, thereafter, an exposure process and a development process are performed using a predetermined photomask, and a photoresist as a photosensitive material is patterned.

Thereafter, ITO is etched from the patterned photoresist using an etching mask. Thus, the first substrate 11 and the second substrate 12 are aligned with the first display electrode 13 and the second display electrode 14, and the first substrate 11 and the second substrate 12 are aligned. The first alignment mark 15 and the second alignment mark 16 are formed simultaneously. Note that this I
The etching of TO is performed by wet etching using a mixed solution of ferric chloride and hydrochloric acid.

Thereafter, a photosensitive resin having an epoxy resin material as a base material is coated on the entire surface of the second substrate 12 by a spinner spin coating method, for example, to a thickness of 6 μm corresponding to the gap size.
It is formed uniformly with a thickness of m. As the organic film 17, V-259PA (trade name) manufactured by Nippon Steel Chemical Co., Ltd. is used.

Here, it is difficult to obtain an organic film 17 having a thickness of 6 μm at a time by the ordinary spinner spin coating method, and the spinner spin coating step and the drying step are repeated two to three times to perform the recoating. An organic film 17 having a thickness of 6 μm is formed.

Further, using a predetermined photomask, exposure processing is performed under exposure conditions corresponding to the film thickness, and further development processing is performed, and the organic film 17 is formed on the non-display portion 24 of the second substrate 12 outside the seal 20. To form This organic film 17
Do not overlap the seal 20.

The development process was carried out using MF-312 (trade name) manufactured by Shipley Co., Ltd. as a developing solution at a temperature of 23 ° C. for 1 minute and then in a clean oven in a nitrogen atmosphere at a temperature of 220 ° C. Heat treatment is performed for 2.5 hours.

Thereafter, the first substrate 11 and the second substrate 12
Is subjected to a washing treatment using a surfactant. After that, the first alignment film 1 made of a polyimide resin is slightly larger than the display portion 23 formed by the first display electrode 13 and the second display electrode 14 and inside the seal 20.
8 and the second alignment film 19 are formed by a printing method.

Here, the first alignment film 18 and the second alignment film 1
9 is formed with a thickness of 70 nm. In addition, as the first alignment film 18 and the second alignment film 19, SE-150 (trade name) manufactured by Nissan Chemical Industries, Ltd. is used. Then the first
The alignment film 18 and the second alignment film 19 are heat-treated in a nitrogen atmosphere using a clean oven at a temperature of 250 ° C. for 1 hour.

After that, the surfaces of the first substrate 11 and the second substrate 12 are coated with a roll of cotton cloth in a direction of aligning the liquid crystal 22 by a rubbing method.
A rubbing process of rubbing once by rotation is performed, and an alignment process of the first alignment film 18 and the second alignment film 19 is performed.

Thereafter, as a thermosetting epoxy resin having a viscosity adjusted to 400 poise, Struct Bond (trade name) manufactured by Mitsui Toatsu Co., Ltd. −
Seal 20 in which 60S (trade name) is mixed at a ratio of 1 part
Is formed on the inside of the organic film 17 of the second substrate 12 by a screen printing method.

After that, the first alignment mark 15 and the second alignment mark 1 are
6, the first substrate 11 and the second substrate 12 are superposed. Further, fine adjustment of the alignment between the first alignment mark 15 and the second alignment mark 16 is performed using a binocular microscope.

Then, the first substrate 1 and the second alignment mark 16 which have been subjected to the fine adjustment of the alignment are aligned so that the first alignment mark 15 and the second alignment mark 16 do not shift.
A plurality of points around the side surfaces of the first and second substrates 12 are bonded with an adhesive that is cured by irradiation with ultraviolet light.

After that, the first substrate 11 and the second substrate 12 which have been superposed are set on a seal hardening jig, and a pressure of 0.3
While pressurizing at a pressure of kg / cm2, a temperature of 150
The seal 20 is cured by performing a heat treatment at a temperature of 3 ° C. for 3 hours.

As a result, a plurality of continuous liquid crystal display panels into which no liquid crystal is injected can be formed. Thereafter, the liquid crystal 22 is injected into a plurality of separated liquid crystal panels obtained from a large substrate by a scribe process and a break process, thereby completing a monochrome liquid crystal display panel.

When it is desired that the first display electrode 13 is exposed for the purpose of mounting, unnecessary portions of the second substrate 12 and the organic film 17 are formed by scribe processing and break processing as shown in FIG. Get rid of.

Although the embodiments of the present invention have been described for a monochrome liquid crystal display panel, the present invention is applicable to all liquid crystal display panels regardless of the presence or absence of a color filter and the driving method.

[0048]

As is apparent from the above description, in the present invention, the organic film is evenly provided on the non-display portion outside the seal of the liquid crystal display panel, and the first substrate and the second substrate have no gap. It is in close contact with a thickness approximately equal to the gap size. For this reason, the gap of the liquid crystal display panel can be uniformly controlled without the spacer at the time of curing the seal.

Further, in the liquid crystal display panel of the present invention, since there is no spacer in the display portion inside the seal, a decrease in contrast can be prevented, and the display portion has no rough feeling and a clear display can be obtained. It contributes to the improvement of display quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 3 is a plan view showing a liquid crystal display panel according to an embodiment of the present invention and a conventional technique.

FIG. 4 is a cross-sectional view showing a structure of a liquid crystal display panel according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st board | substrate 12 2nd board | substrate 15 1st alignment mark 16 2nd alignment mark 17 organic film 20 seal 23 display part 24 non-display part

Claims (2)

[Claims] 1. A non-display portion outside a seal of a liquid crystal display panel having a display electrode, an alignment film, a seal and a liquid crystal has a uniform gap between the first substrate and the second substrate with a thickness substantially equal to the gap dimension. A liquid crystal display panel having an organic film for maintaining the liquid crystal display. 2. The liquid crystal display panel according to claim 1, wherein a display electrode of the first substrate in a non-display portion outside the seal is exposed.