JPH0961849A - Liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element which prevents the oozing of a sealing material and with which an improvement in productivity is made possible. SOLUTION: This liquid crystal display element includes a first electrode substrate 11 on which thin-film transistors(TFTs) and passivation layers 13 covering these TFTs are formed, a second electrode substrate 21 which is arranged to face this first electrode substrate 11 apart a prescribed spacing and is formed with color filters 23 on the surface opposite to the TFTs, spacers which are interposed between the first and second substrates 11, 21 and maintain a spacing, an adhesive layer 15 which is interposed between the first and second substrates 11 and 12 so as not to overlap on the passivation layers 13 and seal the circumference of the spacing and a liquid crystal layer which is housed in the spacing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display element, and more particularly to a structure of a liquid crystal display element capable of improving productivity.

[0002]

2. Description of the Related Art Liquid crystal display elements have the great features of thinness, light weight and low power consumption.
It is widely used as a display device for OA devices such as Japanese word processors and desktop personal computers, projection televisions, and small televisions.

Among such liquid crystal display elements, a liquid crystal display element for performing color display using a CF (color filter), and in particular, a TFT (Thin Film T) on a substrate.
There is an increasing demand for a liquid crystal display element using a so-called active matrix type in which a switching element array such as a transistor is arranged. Therefore, as a method of manufacturing a liquid crystal cell for increasing the number of products, the CF substrate 1
A method of combining substrates has been performed in which one pattern is formed on one sheet and one pattern is formed on one TFT substrate.

[0004]

However, in order to increase the number of liquid crystal cells produced, it is necessary to shorten the processing time of each process or increase the number of manufacturing facilities. However, shortening the processing time may result in defective products,
Since increasing the manufacturing equipment will increase the cost,
Not preferred.

For these reasons, it is desired that both the CF substrate and the TFT substrate are formed of large-sized substrates so that display elements can be arranged in multiple planes. However, the ratio of non-defective products for large-sized substrates with multi-faceted display elements is about 80%.
Since it is low, there is a high possibility that defective and non-defective CF substrates and TFT substrates will be combined. Even if a large-sized substrate is used, the number of products does not necessarily increase.

Therefore, under the present circumstances, it is considered preferable to manufacture a liquid crystal cell by combining a large-sized TFT substrate having a high yield rate with a CF substrate arranged on one side or two sides.

In the production of such a liquid crystal cell, after washing, alignment film formation and alignment treatment are carried out in the usual steps,
As an assembly process, spacers are formed on the CF substrate and TF
It is preferable to apply a seal to the T substrate. However, when the seal coating is applied to the TFT substrate side and dried, the seal material oozes out into the display pixel area along the wiring.

As described above, if the sealing material leaks out into the display pixel area, the orientation becomes defective, and the impurities are mixed into the TFT, so that the TFT becomes defective or destroyed. The present invention has been made to solve such problems, and an object of the present invention is to provide a liquid crystal display device capable of preventing exudation of a seal material and improving productivity.

[0009]

According to the present invention, a thin film transistor and a first electrode substrate on which a passivation layer covering the thin film transistor is formed, and a first electrode substrate are arranged to face each other with a predetermined gap. A second electrode substrate having a color filter formed on a surface facing the thin film transistor, a spacer interposed between the first and second substrates and holding the gap, and the spacer does not overlap the passivation layer. Thus, there is provided a liquid crystal display device comprising an adhesive layer interposed between the first and second substrates and sealing the periphery of the gap, and a liquid crystal layer housed in the gap.

As the adhesive, a thermosetting adhesive, an ultraviolet curable adhesive or the like can be used. In the liquid crystal display element of the present invention, an adhesive layer (sealing material) is applied so as not to overlap the passivation layer. The adhesive layer only needs to be provided so as not to overlap the passivation layer, and therefore the adhesive layer and the passivation layer may be separated from each other. However, if the separation distance is too large, the pixel area becomes small, so the separation distance between the adhesive layer and the passivation layer is preferably 1 to 300 μm.

The viscosity of the sealing material is preferably 100 to 700 poise. Below 100 poise, the viscosity is low and it is difficult to apply the seal. In addition, seal bleeding is likely to occur along the wiring. On the other hand, when it is 700 poises or more, the viscosity is high and it is difficult to apply the sealing material, and at the same time, it becomes difficult to control the thickness of the liquid crystal cell.

The passivation film (SiNx) provided in the general TFT structure is formed in a portion other than the pixel portion and the lead line of the signal line and the scanning line. Therefore, conventional TF
In the T structure, the sealing material is applied on the aluminum film and the SiNx film. In such a structure, the sealing material is Si
The display pixel region is infiltrated along the Nx film. The degree of penetration depends on the viscosity of the sealant used or the low molecular weight substance in the sealant.

According to the liquid crystal display element of the present invention, since the seal coating portion of the TFT substrate does not have the SiNx film, the sealing material does not exude along the signal line or scanning line electrode. Alignment failure or T due to exudation
It is possible to provide a liquid crystal display element having no FT defect.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A liquid crystal display device according to an embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an extracted planar structure of the upper left one surface of a six-sided TFT substrate in a liquid crystal display element according to an embodiment of the present invention.

In FIG. 1, a passivation film 2 is formed around the pixel region 1, and a seal material 3 is applied around the passivation film 2. Note that reference numerals 4 and 5 indicate a signal line and a scanning line, respectively.

When a liquid crystal display device is manufactured by using the TFT substrate shown in FIG. 1 and combining it with the one-sided color filter substrate, first, the TFT substrate and the color filter substrate are washed and then An alignment film is formed and alignment treatment is performed. Next, a spacer is formed on the color filter substrate, and on the other hand, a seal material made of an acrylic modified epoxy resin, which is a thermosetting adhesive, is formed around each of the six pixel areas of the TFT substrate. Apply and dry. in this case,
The seal material 3 is applied so as not to overlap the passivation film 2.

Next, the TFT substrate and the six color filter substrates are aligned and opposed to each other, and sealed with a spacer at a predetermined gap, and the liquid crystal is further placed in the gap. Six liquid crystal cells are formed by injecting the composition and sealing the injection port.

FIG. 2 is a diagram showing an outline of the sectional structure of the peripheral portion of the liquid crystal cell thus obtained. That is, TF
A signal line 12 is formed on the glass substrate 11 on the T substrate side, a passivation film 13 is formed on the signal line 12, and an alignment film 14 is further provided thereon. A sealant layer 15 is applied to the peripheral edge of the glass substrate 11 so as not to overlap the passivation film 13.

On the other hand, the glass substrate 2 on the color filter side
A black matrix 22 and a color filter 23 are provided on the protective film 2 and
Covered by 4. In addition, ITO is formed on the protective film 24.
Is formed of a transparent electrode 25, and an alignment film 26 is provided on the transparent electrode 25.

A liquid crystal display element in which the TFT substrate 1 and the color filter substrate 2 shown in FIG. 1 are combined is manufactured as follows. That is, 6-sided TFT substrate 11 and 1
The impositioned color filter substrate 21 is washed, an alignment film is formed, and an alignment treatment is performed. Next, a spacer is formed on the color filter substrate 21, a sealant is applied to the peripheral portion of the TFT substrate 11 and dried. After that, the TFT substrate 1
1 and the color filter substrate 21 are aligned and sealed to obtain a liquid crystal container. After injecting the liquid crystal composition into the liquid crystal container through the injection port, the injection port is closed to obtain a liquid crystal display element.

In the liquid crystal display device manufactured as described above, the seal material is applied so as not to overlap the passivation film. Therefore, the sealing material does not seep out along the signal lines and the scanning lines of the TFT substrate.
Furthermore, in the manufacturing process described above, the TFT is mounted on a large-sized substrate.
Since 6 are arranged, the productivity could be improved. In the above examples, the thermosetting adhesive was used as the sealing material, but the same result was obtained even when the ultraviolet curing epoxy resin was used.

[0022]

As described above, according to the present invention,
Since the seal application part of the TFT substrate does not overlap the passivation film, the seal material does not exude along the signal line or scanning line electrode, and therefore, the alignment defect or the TFT defect due to the exudation of the seal material occurs. It is possible to provide a liquid crystal display element that does not have the above.

[Brief description of drawings]

FIG. 1 is a diagram in which a planar structure of an upper left one surface of a six-sided TFT substrate in a liquid crystal display element according to an embodiment of the present invention is extracted and shown.

FIG. 2 is a diagram showing a sectional structure of a peripheral portion of a liquid crystal display element according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pixel area 2, 13 ... Passivation film 3, 15 ... Seal material 4, 12 ... Signal line 5 ... Scan line 11 ... TFT substrate 14, 26 ... Alignment film 21 ... Color filter-substrate 22 ... Black Matrix 23 ... Color filter 24 ... Protective film 25 ... Transparent electrode

Claims (1)

[Claims] 1. A first electrode substrate having a thin film transistor and a passivation layer covering the thin film transistor, and a first electrode substrate facing the first electrode substrate with a predetermined gap therebetween. A second electrode substrate having a color filter formed thereon, and the first electrode substrate
And a spacer that is inserted in the gap between the first substrate and the second substrate and that holds the gap and the spacer between the first and second substrates around the pixel region so as not to overlap the passivation layer. A liquid crystal display device comprising: an adhesive layer that is inserted and seals the periphery of the pixel region; and a liquid crystal layer that is housed in the gap.