JPH10268276A - Liquid crystal display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a substrate end part from chipping when the substrate is positioned and to prevent a defect in manufacture from being caused by making obtuse the angle of intersection between at least one of the top and reverse surfaces of the substrate and the end surface without forming an acute- angle part at the substrate end part. SOLUTION: An end surface part 20c which slants so as to move to inside the substrate 20 as the top surface 20a of the glass substrate 20 is approached and an end surface part 20d which slants so as to move to inside the substrate 20 as the reverse surface 20b is approached are formed. A glass substrate 30 has its end surface part 30c formed almost vertically, and the mutually crossing corner parts of the top surface 30a and reverse surface 30b of the end surface part 30c are cut obliquely to form end surface parts 30d and 30e. Neither of the glass substrates 20 and 30 has acute-angle part formed at the intersection part between the top and reverse surfaces and the end surface and in the end surface, so the glass substrates 20 and 30 never chip even when their end parts are stressed strongly.

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 and a method for manufacturing the same, and more particularly, to an edge shape of a substrate constituting the liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display device, two substrates made of a light-transmitting material such as glass are joined at an interval via a sealing material or the like, and a liquid crystal layer is injected between these substrates. A liquid crystal cell having such a configuration is generally used. When this liquid crystal cell is formed, a wiring layer, a pixel electrode, and the like are formed in advance on the inner surfaces of the two substrates, and an interval of, for example, about 5 μm is obtained between the two substrates via a sealing material. So that they can be attached together.

In the manufacturing process of the liquid crystal display device,
Cut and use a substrate of a size suitable for the above liquid crystal cell from a large original substrate, or cut the original substrate in the middle after performing many of the manufacturing processes with the original substrate, or complete the liquid crystal cell After that, the original substrate may be cut into individual liquid crystal cells by cutting.

Further, one of the two substrates constituting the liquid crystal cell is cut in advance into a size corresponding to the liquid crystal cell, and the other substrate is left as a large original substrate. In some cases, a liquid crystal cell is formed by sequentially attaching a small substrate to the substrate. In this case, as shown in FIG. 5, the small substrate 10 is sucked and held by the suction head 1, carried out from the material supply position, and once placed on the positioning table 2. Here, by positioning the positioning members 3 and 4 against the end face 10a of the substrate 10 and holding the substrate 10,
The substrate 10 is corrected to an accurate position on the positioning table 2, and then the substrate 10 is suction-held by the suction head 1 again, transported onto an original substrate (not shown), and is sealed at a predetermined position on the original substrate via a sealing material. Attach. Such a positioning process is not limited to the substrate attaching process, and may be performed before performing various processes on the substrate 10 in order to define the transport position of the substrate 10.

[0005]

As described above, after the positioning is roughly performed by bringing the positioning members 3 and 4 into contact with the end surface 10a of the substrate 10 shown in FIG.
When various processes are performed on the end surface 10 of the substrate 10,
a is applied to the end of the substrate when a is in contact with the positioning members 3 and 4 or when pressed by the suction head 1 from above while being held between the positioning members 3 and 4 as shown in FIG. End may be chipped.
Such chipping at the edge of the substrate, particularly when the inner surface side where the pattern structure is formed on the substrate is largely chipped, may damage the pattern structure formed on the surface or break the seal when attaching the substrate. Or a defective cell thickness. In addition, there is a risk that a defective display may occur if a chipped chip enters the cell.

Generally, the substrate used in the liquid crystal display device has an angle between the front surface or the back surface of the substrate and the end face 10a of about 90 degrees.
In practice, as shown in FIG. 5, the end surface 10a of the substrate is often slightly inclined with respect to the front and back surfaces of the substrate. Since the intersection between one of the end surfaces and the end face becomes an acute angle, there is a problem that the acute angle portion is particularly easily chipped.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, by preventing chipping of a substrate end portion at the time of positioning of the substrate or the like, thereby causing a manufacturing defect. And to improve the yield of the liquid crystal display device.

[0008]

Means taken by the present invention to solve the above-mentioned problem is a liquid crystal display device in which two substrates are joined at an interval and a liquid crystal layer is sandwiched between the substrates. A liquid crystal display device characterized in that at least one of the substrates has an obtuse angle of intersection between the front and back surfaces and the end surface, and no acute angle portion is formed at the end of the substrate.

According to this means, since the intersection angle between the front and back surfaces of the substrate and the end surface is formed at an obtuse angle, and no acute angle portion is formed at the end portion of the substrate, when positioning is performed by the end surface of the substrate, Since the occurrence of chipping at the ends is suppressed, it is possible to reduce the occurrence of display defects due to defects in the liquid crystal cell due to the chipped portions and fragments generated by chipping.

In addition, two substrates are joined at an interval,
In a method of manufacturing a liquid crystal display device having a liquid crystal layer sandwiched between substrates, the intersection angle between the front and back surfaces and the end surface of at least one of the substrates conveyed during the manufacturing process becomes an obtuse angle,
This is a method for manufacturing a liquid crystal display device, characterized in that the liquid crystal display device is formed in advance so that an acute angle portion is not formed at an end of the substrate.

Here, there is a step of forming one of the substrates by cutting the original substrate, and in this step,
Cutting the original substrate obliquely so that the intersection angle between the front surface and the cut surface is obtuse from the front surface side, and obliquely cutting the original substrate so that the intersection angle between the back surface and the cut surface is obtuse from the back surface side And a step of cutting into pieces.

According to this means, the cut surface is formed obliquely from the front and back to remove the acute angle portion of the substrate end portion or to prevent the sharp angle portion from being formed. can do.

In some cases, the method further comprises a step of positioning the substrate by bringing an end face of the substrate into contact with a positioning member when the substrate is transported.

According to this means, since the positioning is performed by bringing the end face of the substrate into contact with the positioning member, it is particularly effective to reduce the occurrence of chipping by the substrate having the end face without an acute angle portion.

[0015]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. 1A and 1B show the cross-sectional shape of a substrate used in an embodiment of a liquid crystal display device and a method of manufacturing the same according to the present invention.

In the glass substrate 20 shown in FIG. 1A, an end surface portion 20c formed in advance on the side of the surface 20a of the glass substrate 20 and inclined so as to move inside the substrate 20 as approaching the surface 20a. And an end surface portion 20d formed on the side of the back surface 20b and inclined so as to move toward the inside of the substrate 20 as approaching the back surface 20b. Here, the intersection angle between the surface 20a of the substrate 20 and the end surface portion 20c is an obtuse angle,
The intersection angle between the back surface 20b and the end surface portion 20d is also an obtuse angle. Further, the intersection angle between the end face part 20c and the end face part 20d is also an obtuse angle. For this reason, no acute angle portion is formed at the end of the substrate.

The glass substrate 30 shown in FIG. 1 (b) has an end face 30c formed so as to be substantially vertical, as usual, and then makes a corner where the end face 30c intersects with the surface 30a obliquely. Cut to form an inclined end face portion 30d so as to move inward as approaching the surface 30a,
Further, a corner portion where the end surface portion 30c and the back surface 30b intersect is cut obliquely to form an end surface portion 30e which is inclined so as to move inward as approaching the back surface 30b.

In any of the above-described glass substrates 20 and 30, since no sharp corner is formed at the intersection between the front and back surfaces and the end surface or in the end surface, a strong stress is applied to the end portions of the glass substrates 20 and 30. Chipping hardly occurs, and the conventional problem does not occur.

The end surfaces 20c, 20d, 30d, 30e of the glass substrates 20, 30 shown in FIG.
The glass substrate 30 can be formed by cutting the glass substrate obliquely with respect to the front surface 20a, 30a and the back surface 20b, 30b using a rotary blade such as a diamond cutter. Also, a groove-like flaw extending along the cutting line is formed by cutting obliquely on the front surface 20a, 30a or the back surface 20b, 30b, and an oblique fracture surface is formed by applying stress from the opposite side. Thereafter, it can also be formed by forming a similar flaw slightly inside the fractured portion on the surface opposite to the surface on which the flaw was previously formed to form a similar oblique fracture surface. Note that the glass substrate shown in FIG. 1 can also be formed by polishing or dicing the edge of a normal substrate.

FIG. 2 is a schematic process diagram showing a part of the manufacturing process in this embodiment. A large number of glass substrates 20 are arranged in the material supply unit 40, from which the glass substrates 20 are sucked and held one by one using the suction head 1, and are conveyed to the positioning unit 50. The glass substrate 20 placed on the support member 51 of the positioning section 50 is once released from the suction head 1 and its position is corrected by the positioning members 52 and 53. The glass substrate 20 whose position has been corrected is sucked and held by the suction head 1 again, and is conveyed to the substrate sticking section 60.

A transfer plate 62 provided by a transfer roller 61 is movably provided on the substrate sticking section 60. The large glass substrates 21 are arranged on the transfer plate 62 and are sequentially moved. ing. A plurality of liquid crystal display areas are formed on the large glass substrate 21, and a sealant (not shown) is applied by a dispenser or the like so as to surround these liquid crystal display areas. Suction head 1
The glass substrate 20 sucked and held is pressed against the sealing material from above so as to match the liquid crystal display area on the large glass substrate 21, and is adhered to the large glass substrate 21.

When the glass substrate 20 is stuck on each liquid crystal display area on the large glass substrate 21, the large glass substrate 21
Proceeds to a substrate pressing step (not shown).

FIGS. 3 and 4 show the structure of the positioning portion 50. FIG. Four support members 51 supported and fixed to a frame (not shown) are arranged in the positioning portion 50, and inclined surfaces 51a for supporting the glass substrate 20 are formed at the distal ends of these support members, respectively. .

A pair of fixed positioning members 52 and movable positioning members 53, 54, 55 are provided between the supporting members 51. The fixed positioning member 52 is a glass substrate 2
0 apex 52a abutting on the right end face in FIG.
It has. In addition, the movable positioning members 53, 54, 5
5 are tip apexes 53a, 5a respectively contacting the left end surface, the upper end surface, and the lower end surface of the glass substrate 20 in FIG.
4a and 55a are provided, respectively, and are configured so as to be able to protrude and retract with respect to the glass substrate 20, respectively, so that the glass substrate 20 can be pressed at a predetermined pressure by a driving device (not shown).

The above-mentioned support member 51 and fixed positioning member 5
2 and the movable positioning members 53, 54, 55 are all formed by coating a resin such as tetrafluoroethylene on the outer surface of a metal core made of stainless steel or the like.

When the glass substrate 20 is placed on the supporting member 51 by the suction head 1, the movable positioning member 53,
54 and 55 are moved so as to project, respectively, and the respective end surfaces of the glass substrate 20 are respectively apexed portions 53a and 54a.
A predetermined pressure is applied by a and 55a. Then, the glass substrate 20 is sandwiched by the fixed positioning member 52 and the movable positioning members 53, 54, 55, and is positioned on the inclined surface 51 a of the support member 51 in a substantially horizontal posture.

In this state, the suction head 1 descends again from above, and the glass substrate 20 is held by the suction head 1. Next, the movable positioning members 53, 5
4 and 55 are respectively retracted to the rear, and then the suction head 1
Is lifted upward and transported to the substrate attaching section 60.

In the positioning portion 50, the positioning is performed in a state where the glass substrate 20 is mounted on the inclined surface portion 51a of the support member 51, so that the glass substrate 20 moves and is positioned with good followability. And positioning can be performed with high precision.

Further, since the followability of the glass substrate 20 is increased by the support member 51 as described above, sufficiently accurate positioning can be performed even if the pressing force of the fixed or movable positioning member is reduced. Therefore, chipping of the end of the glass substrate 20 can be prevented.

[0030]

As described above, according to the present invention, the following effects can be obtained.

According to the first or second aspect, since the intersection angle between the front and back surfaces of the substrate and the end surface is formed at an obtuse angle and no acute angle portion is formed at the end portion of the substrate, positioning is performed by the end surface of the substrate. In this case, the occurrence of chipping at the end of the substrate is suppressed, so that it is possible to reduce the occurrence of display defects due to defects in the liquid crystal cell due to the chipped portions and fragments caused by chipping.

According to the third aspect, the cut surface is formed obliquely from the front and back sides to remove the acute angle portion of the substrate end portion or not to form the acute angle portion. Can be formed.

According to the fourth aspect, since the positioning is performed by bringing the end face of the substrate into contact with the positioning member, it is particularly effective to reduce the occurrence of chipping by the substrate having the end face having no acute angle portion.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic diagrams showing a cross-sectional shape of a glass substrate in an embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a schematic process diagram showing an outline of a substrate attaching process in an embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 3 is a longitudinal sectional view showing a structure of a positioning mechanism of a positioning unit in a substrate attaching step of the embodiment.

FIG. 4 is a plan view showing a structure of a positioning mechanism of a positioning unit in a substrate attaching step of the embodiment.

FIG. 5 is a longitudinal sectional view showing a structure of a positioning mechanism of a positioning unit in a conventional substrate attaching step.

[Explanation of symbols]

 20, 30 Glass substrate 20a, 30a Front surface 20b, 30b Back surface 20c, 20d, 30c, 30d, 30e End surface portion 50 Positioning portion 51 Support member 51a Inclined surface portion 52 Fixed positioning member 53, 54, 55 Movable positioning member

Claims (4)

[Claims] 1. A liquid crystal display device comprising two substrates joined at an interval and a liquid crystal layer sandwiched between the substrates, wherein at least one of the substrates has an obtuse angle of intersection between the front and back surfaces and an end surface. A liquid crystal display device, wherein an acute angle portion is not formed at an end of the substrate. 2. In a method for manufacturing a liquid crystal display device in which two substrates are joined at an interval and a liquid crystal layer is sandwiched between the substrates, at least one of the front and rear surfaces of at least one of the substrates conveyed during a manufacturing process. A method of forming a liquid crystal display device in advance so that the intersection angle between the substrate and the end face becomes obtuse and an acute angle portion is not formed at the end of the substrate. 3. The method according to claim 2, further comprising the step of forming one of the substrates by cutting the original substrate, wherein the crossing angle between the surface and the cut surface from the front side is obtuse. Cutting the original substrate obliquely, and obliquely cutting the original substrate so that the intersection angle between the back surface and the cut surface becomes an obtuse angle from the back surface side of the liquid crystal display device, Production method. 4. The method for manufacturing a liquid crystal display device according to claim 2, further comprising the step of positioning the substrate by bringing an end face of the substrate into contact with a positioning member when transferring one of the substrates.