JP2000122074A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of production steps of a picture frame lightproof layer, besides not to prevent injection of a liquid crystal composition into a liquid crystal cell by the picture frame lightproof layer at a position for a sealant injection port, to prevent light leakage from the injection port and to improve display quality. SOLUTION: A picture frame lightproof layer 31 is formed on a periphery of a display region by laminating colored layers 26, 27, 28 corresponding to three primary colors of a color filter 32. Also the film thickness of a picture frame light shielding layer 31a in the vicinity of an injection port 16a of a sealant 16 is reduced by patterning with decreased exposure using a stripe patterned photomask. A gap 33 for injecting a liquid crystal composition 14 between a counter substrate 13 and the layer 31a is formed thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device having a frame light-shielding layer on an electrode substrate.

[0002]

2. Description of the Related Art In a liquid crystal display device which is thin and light and has low power consumption and is frequently used for a display device of a personal OA device and a video display device such as a television, it is necessary to obtain a high-performance, high-definition and high-quality image. Further, an active matrix type color liquid crystal display device in which pixel electrodes arranged in a matrix are driven by switching elements such as thin film transistors (hereinafter referred to as TFTs) has been developed. Such an active matrix type color liquid crystal display device includes an insulating colored layer of red (R), green (G), and blue (B) and a metal film of chromium (Cr) or the like, and covers the upper part of the TFT. A color filter having a TFT light-shielding layer and a frame light-shielding layer made of chrome (Cr) or the like and covering the periphery of the display area is provided on the counter substrate side to perform color display and TF
The T light-shielding layer and the frame light-shielding layer prevent light from entering the TFT and prevent light leakage from around the display area.

However, when a color filter having a TFT light shielding layer and a frame light shielding layer is provided on the counter substrate side,
The width of the light-shielding layer such as the TFT light-shielding layer and the frame light-shielding layer is designed to be large in consideration of the misalignment between the array substrate on which the TFT and the pixel electrode are formed and the counter substrate, and the margin due to the pitch shift between the TFT light-shielding layer and the TFT. Therefore, there is a problem that the aperture ratio of the liquid crystal display device is reduced, and the display quality of the liquid crystal display device is deteriorated due to a decrease in luminance.

For this reason, in recent years, color filters have been developed to reduce the aperture ratio caused by enlarging the light-shielding layer in consideration of misalignment between the array substrate and the counter substrate and the pitch shift between the TFT light-shielding layer and the TFT. A liquid crystal display device in which is provided on the array substrate side has been developed. However, in this case, TF
As a light-shielding film material such as a T light-shielding layer and a frame light-shielding layer, a conductive material such as a metal cannot be used, and it is necessary to use a material having a high insulating property. Specifically, colored layers of three primary colors of red (R), green (G), and blue (B) made of an organic resin insulating film are formed in a stripe shape, and TF is formed with a black organic resin insulating film.
A color filter is completed by forming a light-shielding film of a T light-shielding layer and a frame light-shielding layer, and thereafter, an insulating columnar spacer and a frame-shaped spacer for uniformly maintaining a gap between liquid crystal cells are further formed on the light-shielding film. I was Further, at the time of forming the light-shielding film, a frame light-shielding layer was not provided at a position adjacent to the injection port of the sealant, because it hindered the injection of the liquid crystal composition between the array substrate and the counter substrate.

[0005]

In a conventional color liquid crystal display device in which a color filter is provided on the array substrate side, three primary colors of red (R), green (G), and blue (B) are formed when the color filter is formed. Since the light-shielding layer had to be formed by using a black insulating resin in addition to the colored layer described above, since the frame-shaped spacer and the column-shaped spacer for holding the gap between the substrates were formed, It takes a long time to form a film and form a pattern, which leads to an increase in manufacturing cost.

[0006] Further, since no frame light-shielding layer is formed in the vicinity of the injection port for the sealant, there is also a problem that the contrast is partially reduced due to light leakage from the injection port and the display quality is lowered. Was.

Accordingly, the present invention has been made to solve the above-mentioned problems, and aims to improve the aperture ratio, reduce the number of manufacturing steps of a substrate having a color filter, reduce the manufacturing time, and reduce the cost. It is an object to provide a liquid crystal display device with high display quality.

[0008]

According to the present invention, as a means for solving the above-mentioned problems, a periphery of two substrates arranged opposite to each other is fixed by a sealing means, and a liquid crystal is filled in a gap surrounded by the sealing means. In a liquid crystal display device enclosing the composition, a frame light-shielding layer provided by laminating at least two or more types of insulating layers provided on the periphery of the display area surrounded by the sealing means on one of the substrates is provided. Things.

With the above structure, the present invention provides a frame light-shielding layer by laminating two or more types of insulating films formed on an insulating substrate without providing a black light-shielding film. It is intended to reduce the manufacturing cost.

According to the present invention, as a means for solving the above-mentioned problems, in the above structure, the sealing means has an inlet, and the frame light-shielding layer near the inlet is thinner than the frame light-shielding layer in other areas. Is formed.

By reducing the thickness of the frame light-shielding layer in the vicinity of the injection port, light leakage from the injection port is prevented without hindering the injection of the liquid crystal composition into the gap between the substrates, thereby improving display quality. is there.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to a first embodiment shown in FIGS. Reference numeral 10 denotes an active matrix type color liquid crystal display device,
A liquid crystal composition 14 is disposed in a predetermined gap in a display area surrounded by a sealant 16 via alignment films 15a and 15b.
Is enclosed.

The array substrate 12 is a glass substrate 17
A semiconductor layer 18 made of polysilicon (p-Si) is patterned and formed in a matrix on the semiconductor layer 18. In a corresponding area, a gate electrode 21 integral with a scanning line (not shown) is pattern-formed. A silicon oxide film (SiOx) 22a covering the gate electrode 21, a silicon nitride film (SiNx)
A drain electrode 23 and a source electrode 24 integral with a signal line (not shown) are pattern-formed on the interlayer insulating film 22 made of 22b, and the gate insulating film 20, the interlayer insulating film 22
Is connected to the source region of the semiconductor layer 18 via a through hole formed in the semiconductor layer 18.

On these, colored layers 26 of three primary colors of red (R), green (G) and blue (B) made of an organic resin insulating film,
27 and 28 are patterned in a stripe pattern. Above the TFT 11 on the colored layers 26, 27 and 28, the other two colored layers 26, 27 and 28 are respectively laminated to shield the TFT 11 from light, and furthermore, the gap between the array substrate 12 and the counter substrate 13 is kept constant. A columnar TFT light-shielding layer 30 also serving as a spacer to be held is formed.
In the frame light-shielding area around the eight edges, the coloring layers 26, 2
A frame-shaped frame light-shielding layer 31 which also serves as a spacer for shielding the periphery of the colored layers 26, 27 and 28 by laminating the layers 7 and 28 and for keeping the gap between the array substrate 12 and the counter substrate 13 constant is provided. , A color filter 32.

However, an inlet 16 formed in the sealant 16
The frame light-shielding layer 31a located in the vicinity of
2 are formed to be thinner than the frame light-shielding layer 31b in the other region, and the three primary color layers 26, 27, and 28 constituting FIG.
A gap 33 for injecting the liquid crystal composition 14 is formed between the liquid crystal composition 14 and the counter substrate 13 as shown in FIG. An indium tin oxide (hereinafter referred to as I) is formed on the color filter 32 thus formed.
Called TO. ) Are formed in a pattern in a matrix, and the pixel electrodes 34 are
Source electrode 2 through through holes formed in 7 and 28
4 is connected.

On the other hand, the counter substrate 13 has a counter electrode 37 made of ITO on a glass substrate 36. The array substrate 12 and the opposing substrate 13 are fixed by a sealant 16, and after injecting the liquid crystal composition 14 into the gap between the substrates 12 and 13 from the injection port 16a, the injection port 16a is sealed. To form When the liquid crystal composition 14 is injected from the injection port 16a, the frame light-shielding layer 3 near the injection port 16a is formed.
A gap 33 is formed between 1a and the opposing substrate 13, and the liquid crystal composition 14 is easily injected into the display area from the gap 33.

The color liquid crystal display device 10 thus constructed
In the array substrate 12, the TFT 11, the gate insulating film 20, the gate electrode 21, the interlayer insulating film 22, the drain electrode 23, and the source electrode 24 are formed on the first insulating substrate 17.
Is formed, a color filter 32 is formed on the array substrate 12 by the following manufacturing method.

That is, the signal line (not shown) and the drain electrode 2
3. UV-curable acrylic resin resist CR-200 in which a red pigment is dispersed above the pattern of the source electrode 24
0 (manufactured by Fuji Hunt Technology Co., Ltd.) using a spinner, and applying a light to a portion of the display area and the frame light-shielding area where red (R) is to be colored through a photomask 38,
Irradiate 100 mJ / cm2 with 365 nm wavelength light, develop with 1% aqueous solution of potassium hydroxide (KOH) for 10 seconds,
A red (R) resist CR-2000 is arranged and baked at 230 ° C. for 1 hour to form a 2.0 μm-thick red colored layer 26.

However, a stripe pattern 38a is formed in a region corresponding to the frame light-shielding layer 31a near the injection port 16a of the sealant 16 of the photomask 38, and the resist CR
Since the irradiation light amount to −2000 is reduced as compared with the irradiation light amount to other regions, the red colored layer 26 of the frame light-shielding layer 31a near the injection port 16a formed after development and baking is formed.
The film thickness of “a” is 0.5 to 1.0 μm, which is smaller than the film thickness in other regions.

Similarly, a UV-curable acrylic resin resist CG-2000 (Fuji Hunt Technology Co., Ltd.) in which a green (G) pigment is dispersed by photolithography
UV-curable acrylic resin resist CB-2000 (manufactured by Fuji Hunt Technology Co., Ltd.) in which pigments of blue and blue (B) are dispersed.
For 1 hour, and each of the colored layers 27 having a thickness of 2.0 μm.
28 are formed. As a result, in the display region, a filter portion in which the three primary color layers 26, 27, and 28 are formed in stripes, respectively, and a TFT light-shielding layer 30 in which the three primary color layers 26, 27, and 28 are stacked are formed. , 3 in the frame area
A frame light-shielding layer 31 on which the primary color layers 26, 27, and 28 are laminated is formed.

However, in the region corresponding to the frame light-shielding layer 31a near the injection port 16a of the sealant 16, the resist CG-color is also used for green (G) and blue (B) as well as red (R). 2000, since the amount of light applied to the resist CB-2000 is reduced as compared to the amount of light applied to other regions, the green (G) and blue colors of the frame light-shielding layer 31a near the injection port 16a formed after development and baking. (B) Colored layer 27
a and 28a each have a thickness of 0.5 to 1.0 μm,
A gap 33 for injecting the liquid crystal composition 14 is formed between the frame light-shielding layer 31a and the counter substrate 13 at a position near the injection port 16a, which is thinner than the film thickness of the other region. .

After the color filter 32 is formed in this way, a through hole reaching the source electrode 24 is formed by a photo-etching method, and a 1500 angstrom film of ITO is formed on the through-hole by a photo-etching method. Pattern the pixel electrode 3
4 is formed. Thereby, the pixel electrode 34 is electrically connected to the source electrode 24 via the through hole. afterwards,
AL-1051 which is a polyimide (Nippon Synthetic Rubber Co., Ltd.)
Is coated on the entire surface to a thickness of 500 angstroms, and a rubbing process is performed to form an alignment film 15a.

Next, in the counter substrate 13, the transparent insulating substrate 36 is sputtered to a thickness of 150
A counter electrode 37 of 0 angstrom is formed on the entire surface, and polyimide AL-1051 (Nippon Synthetic Rubber Co., Ltd.)
Is coated on the entire surface by 500 angstroms, and a rubbing process is performed to form an alignment film 15b.

Thereafter, an injection port 16a is provided along the periphery of the display area of the array substrate 12, a sealant 16 is printed, and an electrode transfer material (not shown) for applying a voltage from the array substrate 12 to the counter electrode 13 is provided. ) Is formed on the electrode transfer electrode (not shown) around the sealing agent 16 and the alignment films 15a and 15b are formed.
The array substrate 12 and the opposing substrate 313 are arranged to face each other so that the rubbing directions of the
Is heat-cured to fix both substrates 12 and 13 to form a liquid crystal cell.

Next, a chiral agent was added to the liquid crystal composition 14 (ZLI-1565 (manufactured by E. Merck)) from the injection port 16a by a vacuum injection method or the like. The one added with lwt% is injected. When the liquid crystal composition 14 is injected, the frame light-shielding layer 31a near the injection port 16a becomes the colored layer 26 during pattern formation.
The liquid crystal composition 14 is smoothly injected from the gap 33 because a, 27a, and 28a are thinly formed and the gap 33 is formed between the liquid crystal composition 14 and the array substrate 12. After the liquid crystal composition 14 is injected, the injection port 16a is sealed with an ultraviolet curable resin 46 to complete the color liquid crystal display device 10. In the color liquid crystal display device 10 thus obtained, there was no light leakage at the injection port 16a, and a uniform and good contrast was obtained over the entire display region.

According to this structure, the TFT light-shielding layer 30 and the frame light-shielding layer 31 which also function as spacers are formed of the stripe-shaped colored layers 26 and 27 of the color filter 32,
Since it can be formed by the same material and the same process as 28,
Unlike the conventional case, there is no need to separately form a black light-shielding layer in addition to the three primary color layers to form the TFT light-shielding layer or the frame light-shielding layer. Further, since the step of dispersing the spacers or the step of manufacturing the columnar spacers becomes unnecessary, the number of manufacturing steps of the array substrate 12 can be reduced as compared with the related art, and the manufacturing time can be shortened. Can be achieved.

The color filter 32 is used for the array substrate 12.
Side, the array substrate 12 and the opposing substrate 1
3 without considering the margin of the TFT light shielding layer 30 due to the misalignment with the TFT 3 or the pitch shift from the TFT 11.
The size of the T light-shielding layer 30 can be reduced to a necessary minimum, the aperture ratio can be improved, and the luminance can be improved. Further, the frame light shielding layer 3
At the time of formation 1, at the position near the injection port 16a, the amount of exposure is reduced using a photomask on which a stripe pattern is formed, and only the colored layers 26, 27, and 28 are pattern-formed. The thickness of the liquid crystal composition 14 can be made smaller than that of the liquid crystal composition 14, and a gap 33 can be formed between the frame light-shielding layer 31a and the counter substrate 12, so that the liquid crystal composition 14 does not hinder the injection operation and leaks light from the injection port 16a. And the display quality can be improved.

The present invention is not limited to the above-described embodiment, and can be changed without departing from the spirit of the present invention. For example, the coloring layer is not limited in material, forming method, layer thickness and the like. Method, a printing method, an electrodeposition method, or the like. In the case where a light-shielding layer formed by laminating a coloring layer is also used as a spacer, its layer thickness is also arbitrary according to the gap between the electrode substrates. . Also, the thickness of the frame light-shielding layer near the injection port is not limited as long as the liquid crystal composition can be injected, and when forming the frame light-shielding layer using photolithography technology, a photomask having a dot pattern or a checkered pattern is used. The thickness may be adjusted. Further, the stacking order of the coloring layer and the pixel electrode is not limited, and a coloring layer may be provided above the pixel electrode.

[0029]

As described above, according to the present invention, by forming a light shielding layer by laminating a plurality of colored layers of different colors used for a color filter, a new layer forming process only for the light shielding layer is performed. Need not be performed, the number of manufacturing steps can be reduced, the manufacturing time can be reduced, and the cost can be reduced.
Also, by using the light shielding layer also as a spacer, the dispersing step or the forming step becomes unnecessary, and the number of manufacturing steps can be further reduced. In addition, by forming a colored layer with a photomask having a gradation and reducing the thickness of the light-shielding layer in the vicinity of the injection port, the injection port can be shielded from light without hindering the injection operation of the liquid crystal composition. The display quality can be improved by making the display uniform.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a color liquid crystal display device according to an embodiment of the present invention as viewed from a plane.

FIG. 2 is a schematic sectional view taken along line AA ′ of FIG. 1 of the color liquid crystal display device according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view taken along line BB ′ of FIG. 1 of the color liquid crystal display device according to the embodiment of the present invention.

FIG. 4 is a schematic plan view showing a photomask according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Color liquid crystal display device 11 ... TFT 12 ... Array substrate 13 ... Opposite substrate 14 ... Liquid crystal composition 16 ... Sealant 16a ... Injection port 17 ... Glass substrate 18 ... Semiconductor layer 21 ... Gate electrode 22 ... Interlayer insulating film 23 ... Drain Electrode 24: Source electrode 26, 27, 28: Colored layer 30: TFT light-shielding layer 31: Frame light-shielding layer 32: Color filter 33: Gap 34: Pixel electrode

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H042 AA06 AA15 AA26 2H089 LA09 LA11 LA13 LA42 NA07 PA05 QA12 QA16 2H091 FA02Y FA34Y LA12 LA13 LA17

Claims (3)

[Claims] 1. A liquid crystal display device comprising: two substrates disposed opposite to each other; and a liquid crystal composition sealed in a gap surrounded by the sealing means.
A liquid crystal display device comprising a frame light-shielding layer provided on one of the substrates around a display area surrounded by the sealing means and formed by laminating at least two or more types of insulating layers. 2. A liquid crystal display device comprising: two substrates arranged opposite to each other; and a liquid crystal composition sealed in a gap surrounded by the sealing means.
A filter layer provided on one of the substrates and comprising a plurality of insulative colored layers, and at least two or more types of the insulative colored layers provided on the same substrate as the filter layer and surrounding the display area surrounded by the sealing means; A liquid crystal display device comprising a frame light-shielding layer formed by stacking layers. 3. The sealing device according to claim 1, wherein the sealing means has an inlet, and the frame light-shielding layer in the vicinity of the inlet is formed thinner than the frame light-shielding layer in other areas. Liquid crystal display device in any of them.