JP3105452B2 - Liquid crystal display device and method of manufacturing the same - Google Patents

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 device which can be used for a liquid crystal display cell used in an information processing terminal or a video device, and a method for manufacturing the same, and more particularly to a method for bonding substrates.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device and a method for manufacturing the same have been disclosed in Japanese Patent Application Laid-Open No. 6-214204. FIG. 4 shows a conventional liquid crystal display device and a method of manufacturing the same. Reference numeral 21 denotes a lower substrate having a lower electrode 22 and a lower alignment mark 26, 23 denotes an alignment film, and 25 denotes an upper electrode having an upper electrode 24 and an upper alignment mark 27. A substrate, 28 is a sealing material, and 29 is a liquid crystal.

First, after forming a lower electrode 22 and a lower alignment mark 26 on a lower substrate 21, an alignment film 23 is formed. Similarly, after forming the upper electrode 24 and the upper alignment mark 27 on the upper substrate 25, the alignment film 23 is formed. Next, alignment is performed using the lower alignment mark 26 and the upper alignment mark 27,
Then, the lower substrate 21 and the upper substrate 25 are bonded together. Thereafter, the liquid crystal 29 is injected to obtain a liquid crystal display device.

As described above, the lower alignment marks 2 formed on the lower substrate 21 and the upper substrate 25, respectively.
6 and the upper alignment mark 27 are used, so that accurate bonding of the lower substrate 21 and the upper substrate 25 is expected.

[0005]

However, in the conventional liquid crystal display device and its manufacturing method, alignment marks 26 and 27 are required on both the lower substrate 21 and the upper substrate 25 to be bonded. For this reason, a step of forming both the lower alignment mark 26 and the upper alignment mark 27 occurs, which increases the manufacturing cost which is required to be reduced.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a liquid crystal display device capable of performing accurate bonding between substrates and reducing the manufacturing cost, and a method of manufacturing the same.

[0007]

According to a first aspect of the present invention, there is provided a liquid crystal display device in which a liquid crystal is sealed between a first substrate and a second substrate which are aligned to face each other. An alignment mark is formed on the first substrate so as to align with the external shape of the second substrate.

According to the liquid crystal display device of the first aspect, since the alignment mark of the first substrate and the external shape of the second substrate are aligned, the alignment mark on the second substrate becomes unnecessary. A liquid crystal display device according to claim 2, wherein a liquid crystal is sealed between a first substrate and a second substrate which are positioned so as to face each other, wherein the second substrate is provided on the first substrate. An alignment mark for aligning with the external shape of the substrate and a display-related portion are formed of the same material.

The liquid crystal display device according to the third aspect is the second aspect.
Wherein the display-related portion is an electrode, a wiring, or a non-linear element on the first substrate. According to the liquid crystal display device of the present invention, since the alignment mark of the first substrate is aligned with the external shape of the second substrate, no alignment mark is required on the second substrate. . Further, since the alignment mark and the display-related portion made of the same material are formed on the first substrate, the alignment mark can be formed in the same process as the display-related portion.

The liquid crystal display device according to the fourth aspect is the first aspect.
Alternatively, in claim 2 or claim 3, the second substrate is a transparent film substrate. According to the liquid crystal display device of the fourth aspect, in addition to the function of the first, second or third aspect, since the second substrate is formed of a transparent film substrate, the external shape of the second substrate is free. As well as the weight of the liquid crystal display device.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: positioning a first substrate and a second substrate so as to face each other, and sealing a liquid crystal therebetween. Forming an alignment mark on the first substrate,
This is for positioning the external shape of the second substrate and the alignment mark. According to the method of manufacturing a liquid crystal display device according to claim 5, the alignment mark of the first substrate;
Since the external shape of the second substrate is aligned, no alignment mark is required on the second substrate.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device in which a first substrate and a second substrate are opposed to each other and aligned, and a liquid crystal is sealed therebetween. An alignment mark and a display-related portion are simultaneously formed on the first substrate, and the external shape of the second substrate is aligned with the alignment mark. According to a seventh aspect of the present invention, in the method for manufacturing a liquid crystal display device according to the sixth aspect, the display-related portion is an electrode, a wiring, or a non-linear element on the first substrate.

According to the method of manufacturing a liquid crystal display device of the present invention, the alignment mark of the first substrate is aligned with the external shape of the second substrate.
No alignment mark is required on the second substrate. Further, since the alignment mark and the display-related portion are simultaneously formed on the first substrate, the number of steps can be reduced. According to a eighth aspect of the present invention, in the method for manufacturing a liquid crystal display device according to the fifth or sixth or seventh aspect, the second substrate is a transparent film substrate.

According to the method of manufacturing a liquid crystal display device of the present invention, the second substrate is formed of a transparent film substrate in addition to the function of the fifth, sixth or seventh embodiment. The appearance of the substrate can be freely selected, and the weight of the liquid crystal display device can be reduced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a structural section of a liquid crystal display device, and FIGS. 2A, 2B, and 2C show structural sections of respective steps in a method of manufacturing the liquid crystal display device. 3 (a), 3 (b) and 3 (c) show a planar structure of a positioning portion of the liquid crystal display device.

In FIG. 1, 1 is a transparent first substrate made of glass, 2 is a pixel electrode made of indium tin oxide (hereinafter abbreviated as ITO), 3 is an element pattern having a laminated structure of Al / Ti, and 4 is Alignment marks formed at the same time as the element pattern 3, 5 is a second substrate having a counter electrode 6 made of ITO, 7 is an edge of an external shape serving as a positioning reference of the second substrate 5, and 8 and 9 are each a first edge. A first alignment film and a second alignment film formed on the first substrate 1 and the second substrate 5 are a sealant, and 11 is a liquid crystal.

Next, a manufacturing process of the liquid crystal display device will be described with reference to FIGS. First, in FIG. 2A, a thin film transistor (hereinafter abbreviated as TFT) serving as a switching element of a liquid crystal display device is formed on a first substrate 1 made of glass (# 1737 glass manufactured by Corning Incorporated). Next, after a 100 nm-thick ITO film is deposited by sputtering on the entire surface, the pixel electrode 2 is formed by etching using a photoresist as a mask. Then, Al
And Ti are deposited to a thickness of 300 nm and 100 nm, respectively, and then, by etching using a photoresist as a mask, an element pattern 3 in which the pixel electrode 2 and the TFT are wired and an alignment mark 4 are formed in the same step.

Next, in FIG. 2B, the first alignment film 8 is formed by printing and the sealing material 10 is formed by coating by alignment using the alignment marks 4.
In FIG. 2C, on the second substrate 5 made of a transparent plastic film (Amorix manufactured by Fujimori Industries Co., Ltd.) on which the counter electrode 6 made of ITO is laminated, the edge 7 of the external shape of the second substrate 5 is formed. Is formed, the second alignment film 9 is formed by the printing method.

Next, the first substrate 1 and the second substrate 5 are opposed to each other, alignment is performed using the alignment mark 4 and the edge 7, and the first substrate 1 and the second Is bonded to the substrate 5. Thereafter, the liquid crystal 11 is injected to obtain the liquid crystal display device shown in FIG. Here, the positional relationship between the alignment mark 4 and the edge 7 in a plane is shown in FIG.
(A). In FIG. 3A, the edge 7 for positioning is a corner of the second substrate 5. In addition,
The edge 7 is not limited to the corner portion of the second substrate 5 as shown in FIG. 3A, but may be an uneven portion of the second substrate 5 as shown in FIG. It may be a hole or the like of the second substrate 5 as shown in c).

According to the liquid crystal display device and the method of manufacturing the same, the alignment mark 4 of the first substrate 1 and the edge 7 of the second substrate 5 are aligned with each other. No alignment mark is required on top. Therefore, accurate bonding of the substrates 1 and 5 can be performed, and reduction in manufacturing cost and weight can be achieved. Further, since the alignment mark 4 and the display pattern 3 are formed of the same material on the first substrate 1, the alignment mark 4 can be formed in the same step as the display pattern 3, thereby reducing the number of steps and the manufacturing cost. Can be reduced.

Further, since the second substrate 5 is formed of a transparent plastic film, the edge 7 of the second substrate 5
3 can be freely selected, and various shapes including the shape shown in FIG. 3 can be adopted. In addition, the weight of the liquid crystal display device can be reduced. In the above-described embodiment, the element pattern 3 and the alignment mark 4 have a laminated structure of Al / Ti. However, if the alignment mark 4 can be recognized and can be formed in the same step as the element pattern 3, the Al / Ti can be formed.
However, the present invention is not limited to the laminated structure described above, and for example, the present invention can be similarly applied to Al and Ta in the gate forming step and amorphous Si, polycrystalline Si and poly Si in the TFT forming step. Further, the display-related portion formed simultaneously with the alignment mark 4 may be an electrode, a wiring, a non-linear element, or the like on the first substrate 1, and the alignment mark 4 and the display-related portion are made of different materials. It may be formed in a process.

Further, the second substrate 5 is not limited to a transparent film substrate, but may be, for example, a glass substrate. Further, although the relationship between the alignment mark 4 and the edge 7 is shown in FIGS. 3A, 3B, and 3C, any alignment mark 4 and the edge 7 can be used as long as they can be aligned. Shape may be sufficient.

[0023]

According to the liquid crystal display device of the first aspect,
Since the alignment mark of the first substrate and the external shape of the second substrate are aligned, accurate bonding between the substrates can be performed, and no alignment mark is required on the second substrate, thereby reducing the manufacturing cost. In addition, the effect of reducing the weight can be obtained.

According to the liquid crystal display device of the second or third aspect, the alignment mark of the first substrate and the second substrate are aligned with each other.
Since the external shape of the substrate is aligned, the alignment mark on the second substrate becomes unnecessary. Therefore, accurate bonding between the substrates can be performed, and the manufacturing cost can be reduced and the weight can be reduced. Further, since the alignment mark and the display-related portion made of the same material are formed on the first substrate, the alignment mark can be formed in the same step as the display-related portion, and the number of steps can be reduced, and the manufacturing cost can be reduced. The effect of being able to achieve is obtained.

According to the liquid crystal display device of the fourth aspect, in addition to the function of the first, second, or third aspect, since the second substrate is formed of a transparent film substrate, the appearance of the second substrate is improved. The effect is obtained that the range of application of the substrate whose shape can be freely selected and positioned can be widened and that the weight of the liquid crystal display device can be reduced. According to the method of manufacturing a liquid crystal display device according to the fifth aspect, the alignment mark of the first substrate and the external shape of the second substrate are aligned, so that accurate bonding between the substrates can be performed, and This eliminates the need for an alignment mark on the substrate, thereby achieving an effect of reducing manufacturing cost and weight.

According to the method of manufacturing a liquid crystal display device of the present invention, the alignment mark of the first substrate is aligned with the external shape of the second substrate.
No alignment mark is required on the second substrate. Therefore, accurate bonding between the substrates can be performed, and the manufacturing cost can be reduced and the weight can be reduced. In addition, since the alignment mark and the display-related portion are formed at the same time on the first substrate, the number of steps can be reduced, and the production cost can be reduced.

According to the manufacturing method of the liquid crystal display device of the eighth aspect, in addition to the function of the fifth, sixth or seventh aspect, the second substrate is formed of a transparent film substrate. The outer shape of the substrate can be freely selected, the application range of the substrate that can be aligned is widened, and the effect of reducing the weight of the liquid crystal display device is obtained.

[Brief description of the drawings]

FIG. 1 is a structural sectional view showing a liquid crystal display device and a method for manufacturing the same according to an embodiment of the present invention.

FIG. 2 is a structural cross-sectional view showing a liquid crystal display device and a method of manufacturing the same according to an embodiment of the present invention for each step.

FIG. 3 is a plan view showing an alignment portion of the liquid crystal display device and the method of manufacturing the same according to an embodiment of the present invention.

FIG. 4 is a structural sectional view showing a conventional liquid crystal display device and a method for manufacturing the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 pixel electrode 3 element pattern (display relevant part) 4 alignment mark 5 2nd board | substrate 6 counter electrode 7 edge 8 1st alignment film 9 2nd alignment film 10 sealing material 11 liquid crystal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-194637 (JP, A) JP-A-6-186515 (JP, A) JP-A-2-29682 (JP, A) JP-A-60-1985 26320 (JP, A) JP-A-60-8827 (JP, A) JP-A-1-92721 (JP, A) JP-A-6-214204 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) G02F 1/13 101 G02F 1/1333 500 G02F 1/1339 505

Claims (8)

(57) [Claims] 1. A liquid crystal display device in which a liquid crystal is sealed between a first substrate and a second substrate which are positioned so as to face each other, and an appearance of the second substrate is provided on the first substrate. A liquid crystal display device comprising an alignment mark for aligning with a shape. 2. A liquid crystal display device in which liquid crystal is sealed between a first substrate and a second substrate, which are positioned so as to face each other, wherein an appearance of the second substrate is provided on the first substrate. A liquid crystal display device wherein an alignment mark for aligning with a shape and a display-related portion are formed of the same material. 3. The liquid crystal display device according to claim 2, wherein the display-related part is an electrode, a wiring, or a non-linear element on the first substrate. 4. The liquid crystal display device according to claim 1, wherein the second substrate is a transparent film substrate. 5. A method for manufacturing a liquid crystal display device in which a first substrate and a second substrate are positioned so as to face each other, and a liquid crystal is sealed therebetween, wherein an alignment mark is formed on the first substrate. And a step of aligning the external shape of the second substrate with the alignment mark. 6. A method of manufacturing a liquid crystal display device in which a first substrate and a second substrate are positioned so as to face each other and a liquid crystal is sealed between the first substrate and the second substrate, wherein an alignment mark and a display are provided on the first substrate. Forming a related portion at the same time;
A step of aligning the external shape of the substrate with the alignment mark. 7. The method according to claim 6, wherein the display-related portion is an electrode, a wiring, or a non-linear element on the first substrate. 8. The method for manufacturing a liquid crystal display device according to claim 5, wherein the second substrate is a transparent film substrate.