JPH10268326A - Substrate for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the substrate for a liquid crystal display device which is free of mixture of a liquid crystal layer with impurities and a decrease in the retaining force of liquid crystal due to a difficiency in the setting of a photosetting sealing material. SOLUTION: Many gaps 29 of small area for light transmission are arranged and formed almost uniformly at an overlap of the sealing material 24 with a light-shielding conductive pattern 28. Thus, the gaps 29 are provided to secure light irradiation area at the overlap of the sealing material 24 with the conductive pattern 28. Even if the light-shielding conductive pattern 28 overlaps with the photosetting sealing material 24, the sealing material 24 has no insufficiently set part and is able to securely set entirely. When the shape and array of the gaps 29 are so set that light creeps by diffraction, the sealing material 24 at non-gap parts can be set with light which is made incident on the gaps 29 and creeps, thereby securing the setting of the sealing material at the overlap part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a liquid crystal display device in which an opposing substrate is bonded to sandwich a liquid crystal layer.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been widely used as display devices for personal computers and the like, taking advantage of their thin, lightweight, and low power consumption advantages. In particular, a thin film transistor (Thin Film Tran
Active matrix type liquid crystal display devices having switching elements such as sistors are being actively developed because they can display high definition and high image quality.

This active matrix type liquid crystal display device includes an array substrate on which a thin film transistor and a plurality of linear patterns of signal lines and scanning lines connected to the thin film transistor and arranged at right angles to each other are formed; And a counter substrate on which a transparent conductive film is formed. In a state where the liquid crystal layer is sandwiched between the array substrate and the counter substrate, the liquid crystal layer is integrally formed around the liquid crystal layer via a sealing material.

Here, the liquid crystal display device performs a predetermined display operation in response to a signal supplied from an external drive circuit, but terminals for connection to the external drive circuit are provided only on the array substrate. The pixel electrodes on the array substrate are directly supplied with power from the wiring patterns of the signal lines and the scanning lines connected to the connection terminals via the corresponding thin film transistors.

On the other hand, the transparent conductive film formed on the opposite substrate is not directly connected to an external circuit.
For this reason, a transfer electrode is provided on the array substrate to supply power to the counter substrate, and the transfer electrode and an external connection terminal are electrically connected by a conductive pattern. The power is supplied to the transparent conductive film on the counter electrode side via the conductive pattern and the transfer electrode. Note that a conductive metal paste is used for the transfer electrode.

Here, the manufacturing process of the array substrate will be described.

First, molybdenum-tungsten (M) is deposited on an insulating transparent substrate such as glass by sputtering.
oW) A film is formed to a thickness of 3000 Å. Then, a scanning line, a conductive pattern for supplying power to the opposing substrate, and the like are formed in a predetermined shape by a photo-etching method.

Next, a gate insulating film such as silicon oxide (SiO _x ) or silicon nitride (SiN _x ) is
An amorphous silicon (a-Si) film serving as a channel region of a thin film transistor is formed to a thickness of 500 angstroms by a CVD method to have a thickness of 00 angstroms and 500 angstroms. After forming an etching protection film of silicon nitride to a thickness of 3100 angstroms by the CVD method, only this protection film is photo-etched.
It is formed into a predetermined shape by an etching method.

Further, an n ⁺ -type amorphous silicon film is formed to a thickness of 500 angstroms by the CVD method. Thereafter, the amorphous silicon film is formed into a predetermined shape together with the n ⁺ -type amorphous silicon film, and an ITO (Indium Tin Oxide) film is formed as a pixel electrode to a thickness of 400 Å by sputtering. It is formed into a predetermined shape by an etching method.

Next, the scanning line connection terminals and the like are photo-
It is formed into a predetermined shape by an etching method. In addition, aluminum (Al) is 450
A film having a thickness of 0 Å is formed and formed into a predetermined shape by a photo-etching method.

Finally, a protective film of silicon nitride (SiN _x ) is formed to a thickness of 2000 angstroms by a CVD method, and is formed by a photo-etching method to complete an array substrate.

In such an array substrate, a sealing material for sandwiching a liquid crystal layer between the display region and a counter substrate is provided around the display region in which a large number of pixel electrodes are arranged in a matrix. Is provided so as to surround the. In addition, a transfer electrode used for electrical connection with the opposing substrate and a conductive pattern for electrically connecting the transfer electrode to a terminal for external connection are provided.

In recent years, there has been a great demand for liquid crystal display devices to have a higher aperture ratio, so-called lower power consumption, lower cost, and a larger screen. As means for satisfying these requirements, it has been proposed to use a photocurable sealing material instead of a conventional thermosetting sealing material as the sealing material.

The photo-curable sealing material is effective in improving the assembling accuracy of the array substrate and the counter substrate for increasing the aperture ratio, and is also effective in reducing the number of steps for reducing the cost. Is effective because the number of images is reduced, but there are the following problems with the enlargement of the screen.

That is, when the display area is enlarged to enlarge the screen, the so-called frame portion around the area becomes narrower, and the light-shielding conductive pattern to the transfer electrode overlaps with the sealing material. , The overlap increases.

In this case, there is no problem with the conventional thermosetting sealing material. However, in the case of the photocuring sealing material, light is not irradiated to a portion overlapping with the conductive pattern. The curing of the sealing material becomes insufficient. When the photocurable sealing material is not sufficiently cured in this manner, impurities such as ions are mixed into the liquid crystal from the sealing material and the outside of the sealing material, and the retention rate of the liquid crystal is reduced. For this reason, display quality is deteriorated, and the yield is reduced.

As shown in FIGS. 7 and 8, the array substrate 11 is provided with a thermosetting sealing material 12 at a peripheral portion so as to surround a display area (not shown).
Are bonded together. A liquid crystal layer (not shown) is sealed in the interior surrounded by the sealing material 12, and the liquid crystal layer is sandwiched between the array substrate 11 and the counter substrate 13.

At the periphery of the array substrate 11, in addition to the sealing material 12, a transfer electrode 15 is provided for supplying power to the transparent conductive film 14 on the counter substrate 13. A light-shielding conductive pattern 16 is formed to connect to an external connection terminal (not shown). At least one of the transfer electrodes 15, 15a and the conductive patterns 16, 16a overlaps the sealing material 12 due to the enlargement of the screen of the liquid crystal display device. Then, both the transfer electrode 15a and the conductive pattern 16a overlap with the sealing material.

Here, as shown in FIG. 8, the photo-curable sealing material 12 is cured by light L radiated from the back side of the array substrate 11, and is cured at a portion where the transfer electrode 15a and the conductive pattern 16a overlap. Is insufficiently cured because it is not irradiated with light. In particular, the area of the transfer electrode 15a and the conductive pattern 16a in the overlapped area is smaller than the specific area, the area of the area determined from the overlap dimension x of the transfer electrode 15 along the length direction of the sealing material 12 and the width dimension y of the sealing material. If the occupying ratio is large, the sealing material 12 is insufficiently cured,
Problems such as the incorporation of impurities such as ions into the liquid crystal layer and a decrease in the holding power of the liquid crystal occur.

[0020]

As described above, in the array substrate for a liquid crystal display device having a large screen, the peripheral portion of the display area becomes narrow, so that the overlapping portion between the sealing material and the light-shielding pattern is formed. And there is a problem that an insufficiently cured portion is generated in the photocurable sealing material.

The present invention has been made in view of the above problems. Even if a light-curing sealing material overlaps with a light-shielding pattern, impurities may not be mixed into the liquid crystal layer due to insufficient curing or the liquid crystal may be mixed. It is an object of the present invention to provide a liquid crystal display device substrate that does not cause a problem such as a decrease in holding power.

[0022]

A substrate for a liquid crystal display device according to the present invention comprises a pixel electrode arranged in a matrix on an insulative transparent substrate, and a counter substrate with a liquid crystal layer sandwiched therebetween. The formed photocurable sealing material, at least a part of the photocurable sealing material overlaps, a gap for light transmission is formed in the overlapping portion of the conductive pattern, on the transparent substrate And a light-shielding conductive pattern formed. And, since a gap for light transmission is formed at the overlapping portion of the conductive pattern with the photocurable sealing material, light transmitted through this gap is irradiated on the photocurable seal, preventing insufficient curing. I do.

The conductive pattern has a shape capable of curing a photo-curable sealing material that does not overlap with the gap due to the sneak of light incident from the gap. Light is applied to the conductive pattern to cure the photocurable sealing material.

Further, according to the present invention, the light-transmitting conductive material is provided at the overlapping portion of the conductive pattern, so that the light-transmitting conductive material does not block light to the photocurable sealing material. Insufficient curing of the photocurable sealing material due to insufficient irradiation is prevented.

Further, at least a part of the photocurable sealing material overlaps at least a part thereof, and the overlap dimension of the transfer electrode and the width of the photocurable sealing material along the length direction of the photocurable sealing material. The conductive pattern is arranged so that the area occupied by the overlapping part of the conductive pattern is less than the set value with respect to the area determined by the dimensions, and the conductive part is placed so that the overlapping part of the conductive pattern does not concentrate in a limited area near the transfer electrode Since the overlapping part of the pattern is arranged, this overlapping part will be dispersed over a relatively wide range,
Insufficient curing of the photocurable sealing material due to concentration of the light-shielding portion is prevented.

The conductive pattern is a plurality of patterns in which overlapping portions are formed with an interval therebetween, and the interval is at least 100 μm and the overlapping portion has a formation density of less than 50%. Things.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the substrate for a liquid crystal display device of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the array substrate
21 has a transparent substrate 22 having an insulating property such as glass,
On the upper surface of the transparent substrate 22, a display region 23 in which pixel electrodes (not shown) are arranged in a matrix is formed. In addition, a photo-curable sealing material 24 is
Are disposed, and a liquid crystal layer (not shown) is held inside the photocurable sealing material 24. Further, the transparent substrate 22 is provided with a photo-curable sealing material together with a counter substrate (not shown) bonded through a photo-curing sealing material 24.
The liquid crystal layer held inside 24 is sandwiched.

Further, on the periphery of the transparent substrate 22, a terminal 26 for external connection and a transfer electrode 27 for power supply are provided. The external connection terminals 26 are connected to a plurality of linear patterns (not shown) which are arranged orthogonally to each other via an insulating layer on the transparent substrate 22. Pixel electrodes arranged in a matrix are connected to respective intersections in the display area 23 of these linear patterns via thin film transistors (Thin Film Transistors) not shown. The external connection terminal 26 is connected to an external drive circuit (not shown), and each pixel electrode is connected to the corresponding thin film transistor via the external connection terminal 26 and the orthogonally arranged linear pattern from the external drive circuit. To perform a predetermined display operation.

The transfer electrode 27 is used to supply power to a counter substrate (not shown). The transfer electrode 27 is connected to a terminal 26 for external connection by a light-shielding conductive pattern 28. Therefore, the transparent conductive film provided on the counter substrate is supplied with power from an external drive circuit via the external connection terminal 26, the light-shielding conductive pattern 28, and the transfer electrode 27 provided on the array substrate 21 side.

Here, with the enlargement of the screen of the liquid crystal display device,
Since the peripheral portion of the array substrate 21, that is, the width outside the display region 23 is narrow, a part of the photocurable sealing material 24 overlaps a part of the light-shielding conductive pattern 28.
Normally, light for curing the photocurable sealing material 24 is irradiated from the back side of the transparent substrate 22.However, the light-shielding conductive pattern 28 blocks light irradiated from this back side. Light is not applied to the portion of the photocurable sealing material 24 overlapping the light-shielding conductive pattern 28,
Insufficient curing occurs.

In view of this, a large number of small-area gaps 29 for light transmission are formed almost uniformly at the overlapping portion of the light-shielding conductive pattern 28 with the photocurable sealing material 24. These gaps
By providing the light-transmitting member 29, a certain light irradiation area can be ensured even in the overlapping portion of the light-curable sealing material 24 with the light-shielding conductive pattern. That is, the area and the number of the gaps 29 are set so that at least the minimum amount of light irradiation necessary for curing the photocurable sealant 24 can be secured over the entire overlapping portion. Although a square is illustrated as the shape of the gap 29, it is needless to say that a shape other than a square may be used.

With such a configuration, even if the light-curing sealing material 24 overlaps with the light-shielding conductive pattern 28, the sealing material has insufficient curing as in the related art. Without curing, the entire photocurable sealing material 24 can be surely cured, and problems caused by insufficient curing can be solved.

When the shape and arrangement of the gaps 29 are set so as to cause wraparound such as light diffraction, the gaps are set when the light-curable sealing material 24 is cured by light irradiation.
The light-curing sealing material 24 in the non-gap portion can be cured by the sneaking of the light incident on the light 29, and the curing of the photocuring sealing material 24 in the overlapping portion can be reliably performed.

Further, if the light-transmitting conductive material is used only in the overlapping portion of the light-shielding conductive pattern 28 with the light-curable sealing material 24, the cost of the light-curing sealing material 24 can be reduced without a significant increase in cost. Photocuring can be more reliably performed.

Another embodiment will be described with reference to FIGS.

In the embodiment shown in FIGS. 3 and 4, the transfer electrode 2
Although the light-shielding conductive patterns 28 and 28a overlap with the light-shielding conductive patterns 7, 27a, the overlapping portion of the transfer electrode 27 and the light-shielding conductive pattern 28 is not concentrated in a specific area of the photocurable sealing material 24. As a result, the insufficient photocuring of the photocurable sealing material 24 is eliminated.

Here, the specific region is an overlapping portion of the transfer electrode 27 along the length direction of the photocurable sealing material 24.
The area is determined by the size of 27a and the width of the photocurable sealing material 24. The light-shielding conductive pattern 28a in which the light-shielding conductive pattern 28 overlaps the area
The overlapping light-shielding conductive patterns 28a are arranged such that the ratio of the area occupied by the light-shielding portion is equal to or less than a set value.
Specifically, as shown in FIG. 3, the overlapping light-shielding conductive patterns 28a are arranged so as to bypass the outside of the above-described specific region. In addition, the opposing substrate 13 is arranged to face, and a transparent conductive film 14 is formed on the opposing substrate 13.

With this configuration, the light-shielding overlapping portion 27a is not concentrated in the above-described specific region of the light-curable sealing material 24, so that the light-curing sealing material 24 is partially insufficiently light-cured. Can be eliminated.

In this case, the light-shielding conductive pattern 28a overlapping the photocurable sealing material 24 is
This is a multiple pattern formed while maintaining 31
By setting 31 to be not less than 100 microns or less than 50% of the formed density, a photo-curable sealing material can be more reliably achieved.
24 partial light curing deficiencies can be eliminated.

Further, another embodiment will be described with reference to FIGS.

The embodiment shown in FIGS. 5 and 6 differs from the embodiment shown in FIGS. 3 and 4 in that the planar shape of the transfer electrode 27 is substantially trapezoidal and that the transfer electrode 27 overlaps the photocurable sealing material 24. The area of 27a has been reduced. Further, an insulating film 32 is provided so as to cover the transfer electrode 27 and the light-shielding conductive pattern 28 on the transparent substrate 22.

[0043]

According to the liquid crystal display device substrate of the present invention, a gap for light transmission is formed at a portion where the conductive pattern overlaps with the photocurable sealing material. Irradiation to the seal can prevent insufficient curing.

The conductive pattern has a shape capable of curing a light-curable sealing material that does not overlap with the gap due to the sneak of light incident from the gap. Light can be applied to the conductive pattern to cure the photo-curable sealing material.

Furthermore, since the light-transmitting conductive material is provided at the overlapping portion of the conductive pattern, the light-transmitting conductive material does not block light to the photocurable sealing material.
Insufficient curing of the photocurable sealing material due to insufficient light irradiation can be prevented.

Further, at least a part of the photocurable sealing material overlaps at least a part thereof, and the overlap dimension of the transfer electrode and the width of the photocurable sealing material along the length direction of the photocurable sealing material. The conductive pattern is arranged so that the area occupied by the overlapping part of the conductive pattern is less than the set value with respect to the area determined by the dimensions, and the conductive part is placed so that the overlapping part of the conductive pattern does not concentrate in a limited area near the transfer electrode Since the overlapping part of the pattern is arranged, this overlapping part will be dispersed over a relatively wide range,
Insufficient curing of the light-curable sealing material due to concentration of the light-shielding portion can be prevented.

The conductive pattern is a plurality of patterns in which overlapping portions are formed with an interval therebetween, and the interval is at least 100 microns or more, and the overlapping portion has a formation density of less than 50%. By doing
Insufficient curing of the sealing material is reliably prevented.

[Brief description of the drawings]

FIG. 1 is an enlarged plan view showing one embodiment of a substrate for a liquid crystal display device of the present invention.

FIG. 2 is a plan view showing the whole of the same.

FIG. 3 is a plan view showing another embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a plan view showing another embodiment of the above.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a plan view showing a conventional example.

FIG. 8 is a sectional view taken along the line CC in FIG. 7;

[Explanation of symbols]

 13 Opposite substrate 22 Transparent substrate 24 Seal material 27 Transfer electrode 28 Conductive pattern 29 Gap

Claims (5)

[Claims] 1. A photo-curable sealing material formed around a pixel electrode arranged in a matrix on an insulative transparent substrate, an opposing substrate stuck with a liquid crystal layer sandwiched between the pixel electrodes, At least a part of the conductive sealing material overlaps, and a light-shielding conductive pattern formed on the transparent substrate in which a gap for light transmission is formed in the overlapping portion of the conductive pattern. Characteristic liquid crystal display substrate. 2. The conductive pattern according to claim 1, wherein the conductive pattern has a shape capable of curing a light-curable sealing material that does not overlap with the gap due to the sneak of light incident from the gap. Substrate for liquid crystal display. 3. A photo-curable sealing material formed around a pixel electrode arranged in a matrix on an insulating transparent substrate, a counter substrate adhered to a liquid crystal layer sandwiched therebetween, And a light-shielding conductive pattern formed on the transparent substrate and having a light-transmissive conductive material in an overlapping portion of the conductive pattern and at least a part of the conductive sealing material. A substrate for a liquid crystal display device, comprising: 4. A photo-curable sealing material formed around a pixel electrode arranged in a matrix on an insulative transparent substrate, a liquid crystal layer sandwiched therebetween, and an opposing substrate bonded thereto. At least a portion of the sealing material overlaps at least a part, and the area determined by the overlapping dimension of the transfer electrode and the width dimension of the photocurable sealing material along the length direction of the photocurable sealing material, A substrate for a liquid crystal display device, comprising: a light-shielding conductive pattern having a transfer electrode which is arranged so that an area occupied by the overlapping portion of the conductive pattern is equal to or less than a set value and supplies power to an opposite substrate. 5. The conductive pattern is a plurality of patterns in which overlapping portions are formed with an interval, and the interval is one.
00 micron or more, and the overlapping portion has a formation density of 5
The liquid crystal display device substrate according to claim 4, wherein the content is at least one of less than 0%.