JP3202804B2 - Manufacturing method of liquid crystal display - 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 and a method of manufacturing the same. More specifically, the present invention relates to a liquid crystal display device using a substrate on which a short-circuit wiring is formed in order to prevent electrostatic breakdown, and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 6 is an explanatory view showing a main part of a conventional matrix type liquid crystal display device. In the figure, reference numeral 1 denotes a glass substrate on which signal lines for driving each pixel of the liquid crystal display device are formed, and 2 denotes a color filter substrate which is bonded to the glass substrate 1 to constitute a main part of the matrix type liquid crystal display device. 3a, 3b are signal lines formed on the glass substrate 1, 4 is a signal input terminal located at the end of the signal lines 3a, 3b, 5 is a short-circuit wiring for short-circuiting the signal lines 3a, 3b, 6 Indicates a final cutting position of the glass substrate 1, and the glass substrate 1 is cut along this line before performing various inspections, and the short-circuit wiring 5 is removed.

The reason why the short-circuit wiring is provided on the glass substrate 1 is as follows. When a matrix type liquid crystal display device is manufactured, a process such as rubbing is required to rub a polyimide film applied on a glass substrate with a cloth, but this process generates very large static electricity.
In addition, static electricity generated when the substrate is stored or when the substrate is handled has an adverse effect on circuits formed on the glass substrate 1. When an overvoltage due to static electricity is applied between the signal lines 3a and 3b, for example, in a state where there is no short-circuit wire 5 of the signal line 3, the matrix type liquid crystal display device is destroyed or deteriorated by an insulating film separating each line. Becomes defective. When the short-circuit wiring 5 is provided,
Since all the signal lines 3 are kept at the same potential, the above-described electrostatic breakdown does not occur.

On the other hand, in order to perform various inspections on a glass substrate on which a circuit is formed, it is necessary to apply various signals to the signal lines 3a and 3b. Therefore, in this case, the signal line 3 once short-circuited must be electrically separated again. For this reason, before performing various inspections, the glass substrate 1 is cut at the final cutting position 6 of the glass substrate, and the short-circuit wiring 5 is removed.

[0005]

Since a conventional matrix type liquid crystal display device is manufactured by the above-described processes, after various inspections are performed, a short circuit wiring 5 is formed on a glass substrate.
Does not remain. If a defect occurs in the panel assembly process of bonding the glass substrate 1 and the color filter substrate 2, after the inspection, the panel is disassembled into the glass substrate 1 and the color filter substrate 2, and the panel assembly is performed again to repair these defects. There is a need. However, since the short-circuit wiring is removed from the glass substrate in the panel assembling process, when the panel is assembled again, it is not possible to suppress the electrostatic breakdown of the circuit formed on the glass substrate. Therefore, even if a defect is found in the matrix type liquid crystal display device, there is a problem that it cannot be disassembled, reassembled, and repaired.

To solve the above problem, Japanese Patent Application Laid-Open No. 63-85586 discloses
In Japanese Patent Laid-Open Publication No. H11-209, an active matrix display device is proposed in which a short-circuit wire is provided on an outer peripheral portion of a glass substrate, and an end of each signal line is connected to the short-circuit wire via an impedance element.

In the above device, since the impedance element is interposed between the impedance element and the short-circuit wiring, it does not hinder normal operation. However, the device has a problem in that it takes time until each signal line becomes equipotential due to an increase in a time constant due to the presence of impedance, and there is a possibility that electrostatic breakdown may not be completely prevented.

[0008] The present invention has been made to solve the above problems, board that can reshape any readily wiring shorting signal line after the various inspections, a liquid crystal display in which the substrate is used It is an object to provide an apparatus and a method for manufacturing the same.

[0009]

A substrate for a liquid crystal display device according to the present invention is a liquid crystal display having a signal line for driving each pixel of the liquid crystal display device and a short-circuit line connecting the signal line at an end of the signal line. A substrate for a display device,
A short-circuit conductive film intersecting the signal line via an insulating film is provided inside the short-circuit wiring.

Further, a liquid crystal display device according to the present invention comprises:
A liquid crystal display device in which a liquid crystal layer is sandwiched between two transparent substrates, wherein at least one of the transparent substrates has the short-circuiting conductive material.
A substrate having a film is used, and the other transparent substrate is bonded and filled with a liquid crystal material.

Further, a method of manufacturing a liquid crystal display device according to the present invention is a method of manufacturing a liquid crystal display device, the method comprising the steps of: forming a signal line for driving each pixel of the liquid crystal display device; Irradiating a laser beam to each intersection of the line and the short-circuiting conductive film to connect the signal line, bonding to another substrate, filling the liquid crystal material, and cutting inside the short-circuiting conductive film. It is a feature.

Further, a method of manufacturing a liquid crystal display device according to the present invention is a method of manufacturing a liquid crystal display device, comprising the steps of: forming a signal line for driving each pixel of the liquid crystal display device; The signal line is connected by irradiating a laser beam to each intersection of the line and the short-circuiting conductive film, and after being bonded to another substrate, a liquid crystal material is filled. It is characterized by irradiating a laser beam to insulate between signal lines.

[0013]

The conductive film formed on the substrate for a liquid crystal display device according to the present invention is bonded to another substrate and maintains electrical insulation from signal lines during various inspections performed after the liquid crystal is filled. In addition, various inspections can be performed even when the short-circuit wiring exists in the substrate. In addition, when a defect is detected in the liquid crystal display device in various inspections, the signal lines can be easily short-circuited to each other to form a short-circuit wiring, so that there is no adverse effect of static electricity on another substrate again. After bonding and filling the liquid crystal, the above various inspections are performed by finally cutting the inside of the short-circuiting conductive film or irradiating the short-circuiting conductive film between each signal line with a laser beam to insulate it. be able to.

[0014]

FIG. 1 is an explanatory view showing an embodiment of a substrate for a liquid crystal display device according to the present invention. As shown in FIG. 1, signal lines 3a and 3b for driving each pixel of the liquid crystal display device are provided on a glass substrate 1, which is a substrate for a matrix type liquid crystal display device. When the substrate is, for example, a substrate for an active matrix type liquid crystal display device, a switching element such as a thin film transistor is provided at each intersection of the signal lines 3a and 3b by a photolithography technique or the like. The signal line 3
A signal input terminal 4 used for connection to the outside is provided at a portion corresponding to the end of the substrate which is left when the substrate is cut at the final cutting positions 6a and 3b. Short-circuit wires 5 are provided near the periphery of the glass substrate 1, and the short-circuit wires 5 are connected to the signal lines 3 at the ends.

On the other hand, a short-circuit conductive film 7 is provided inside the short-circuit wire 5. This short-circuiting conductive film 7 is shown in FIG.
As shown in the cross-sectional view of FIG.
Is not short-circuited as it is.

The short-circuiting conductive film 7 is made of, for example, chromium,
It is made of a material such as aluminum and has a thickness of 0.1 to
1 μm, and the width is preferably about several μm .

The insulating film 10 is made of, for example, SiN
_x , made of a material such as SiO ₂ , provided on the short-circuiting conductive film 7, and its thickness is preferably about 0.3 μm.

The short-circuiting conductive film 7 and the insulating film 10 can be formed by a method such as a sputtering method or a CVD method.

In the state shown in FIG. 1, since all the signal lines 3a and 3b of the substrate are short-circuited by the short-circuit wiring 5, the circuit formed on the glass substrate is destroyed by static electricity in a process such as rubbing. Instead, a panel assembling process such as formation of an alignment film and alignment processing, bonding with an opposite substrate, filling of liquid crystal, and the like can be performed. In order to perform an electrical inspection of the matrix type liquid crystal display device, a signal line 3 is required.
The glass substrates 1 need to be electrically insulated from each other, and the glass substrate 1 is cut at the cutting position 8 and the short-circuit wiring 5 is removed. At this time, the short-circuiting conductive film 7 remains in the glass substrate, but as shown in FIG.
Since b and the short-circuiting conductive film 7 are insulated by the insulating film 10, the electrical inspection is not affected.

If the electrical inspection reveals that the matrix type liquid crystal display device is defective, the intersection 9 between the signal lines 3a and 3b and the short-circuiting conductive film 7 is prepared for disassembly and reassembly of the display device. Is irradiated with a laser beam such as YAG or Xe. As shown in FIG. 3, the insulating film 10 is broken by the laser beam irradiation, and the electrical connection between the signal lines 3a and 3b and the short-circuiting conductive film 7 is achieved. In this case, the intensity of the laser beam is preferably about 0.1 MJ / m ^{2 in} order to achieve conduction without damaging the substrate or the like. Signal line 3
If a and 3b are electrically connected to the short-circuiting conductive film 7, all the signal lines 3a and 3b are short-circuited to each other. Panel reassembly can be performed.
After reassembly, the glass substrate 1 is moved to the final cutting position 6 in FIG.
And the short-circuiting conductive film 7 is removed. Since the signal lines 3 are electrically insulated again by the disconnection, various electrical inspections can be performed. After the panel assembling process, a polarizing plate, a reflecting plate and the like are attached to complete the matrix type liquid crystal display device.

If no defect is found in the electrical inspection, the substrate is cut again at the final cutting position 6 and a matrix type liquid crystal display device is completed by attaching a polarizing plate or the like.

FIG. 4 shows another embodiment of the substrate for a matrix type liquid crystal display device of the present invention, in which two short-circuiting conductive films are provided. The number of the short-circuiting conductive films is not limited to two, and may be two or more. By providing a plurality of short-circuiting conductive films on the glass substrate 1, connection between the short-circuiting conductive films 7 a and 7 b and the signal lines 3 by laser light, and
The cutting of the short-circuiting conductive films 7a and 7b from the substrate can be repeated a plurality of times, and the disassembly and reassembly of the matrix-type liquid crystal display device can be performed a plurality of times.

In this case, the thicknesses and widths of the short-circuit wires 7a and 7b and the insulating film may be the same as those in the above-described embodiment.

FIG. 5 shows still another embodiment of the substrate for a matrix type liquid crystal display device according to the present invention, in which a short-circuiting conductive film 7 is provided inside the final cutting position 6 of the glass substrate 1. In this case, the thickness and width of the short-circuiting conductive film 7 and the insulating film may be the same as those in the above-described embodiment. When the intersection of the signal line 3 and the short-circuiting conductive film 7 is once short-circuited by laser light irradiation and the signal line 3 is electrically insulated again for inspection, the short-circuiting conductive The film 7 is cut by irradiating a laser beam. At this time, the intensity of the laser beam is preferably about 1 MJ / m ² . By providing the short-circuiting conductive film inside the final cutting position, the cutting may be performed only once, and the size of the glass substrate 1 does not change between the time of the electrical inspection before the reassembly and the time of the electrical inspection after the reassembly. There is no need to modify the electrical inspection device according to the substrate size.

A panel is assembled using the matrix type liquid crystal display substrate, and if no defect is found by inspection, a polarizing plate or the like is attached as it is to complete the matrix type liquid crystal display. In such a case, the substrate may be cut only once.

The liquid crystal display thus obtained is
In the case of an active matrix liquid crystal display device, a switching element for driving each pixel is formed for each pixel on one transparent substrate, and a switching element of each pixel is connected horizontally and vertically by a conductive film. At the end of the transparent substrate. On the other transparent substrate, a counter electrode is formed using a transparent conductive film over the entire display area, and a voltage is applied between each pixel and the counter electrode by driving a switching element through a signal line. It has a configuration. The two substrates are bonded at regular intervals around the display area of each pixel assembly with a sealant, the gap is filled with a liquid crystal material, and only the liquid crystal layer of a certain pixel is applied according to the voltage applied between the two substrates. It is configured to change optically and display the pixel portion.

In the present invention, a substrate is used in which at least one of the substrates has the short-circuiting conductive film formed thereon, and after the transparent substrate is bonded, a liquid crystal material is filled, and the short-circuiting conductive film is formed. The substrate is cut inside the short-circuiting conductive film, or each signal line is separated by irradiating laser light to the short-circuiting conductive film between each signal line so that each signal line is insulated, Thereafter, a liquid crystal display device is completed by providing a polarizing plate and the like.

Although the present invention has been described with reference to an active matrix liquid crystal display device as an example, other liquid crystal display devices have the same effect.

[0029]

As it is evident from the foregoing description, the liquid crystal display device substrate according to the present invention, since the separate short-circuit conductive film and the short-circuit wiring is provided, and a display defect by the electrical inspection of a liquid crystal display device If found, it can be disassembled and reassembled. Therefore, the yield of the manufacturing process of the liquid crystal display device is improved, and the cost can be significantly reduced.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing an intersection of a short-circuiting conductive film and a signal line of the liquid crystal display device substrate of the present invention.

FIG. 3 is a cross-sectional view showing a state after an intersection of a short-circuiting conductive film and a signal line of a substrate for a liquid crystal display device of the present invention is irradiated with laser light.

FIG. 4 is an explanatory view showing another embodiment of the substrate for a liquid crystal display device of the present invention.

FIG. 5 is an explanatory view showing still another embodiment of the substrate for a liquid crystal display device of the present invention.

FIG. 6 is an explanatory view showing a conventional substrate for a liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Color filter substrate 3, 3a, 3b Signal line 4 Signal input terminal 5 Short circuit wiring 6 Final cutting position 7, 7a, 7b Short conductive film 8, 8a, 8b Cutting position 9, 9a, 9b Intersection 10 Insulating film 12 Laser light

Continuation of front page (56) References JP-A-3-134628 (JP, A) JP-A-6-59281 (JP, A) JP-A-6-59282 (JP, A) JP-A-4-221926 (JP) JP-A-3-209430 (JP, A) JP-A-2-190820 (JP, A) JP-A-3-94223 (JP, A) JP-A-3-249624 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345

Claims (2)

(57) [Claims] 1. A signal line for driving each pixel of a liquid crystal display device and a signal line of a substrate on which a short-circuiting conductive film crossing the signal line via an insulating film is formed at each intersection of the signal line and the short-circuiting conductive film. A method of manufacturing a liquid crystal display device, comprising irradiating a laser beam to connect the signal lines, bonding the signal lines to another substrate, filling a liquid crystal material, and cutting the inside of the short-circuiting conductive film. 2. A signal line for driving each pixel of a liquid crystal display device, and a signal line of a substrate on which a short-circuiting conductive film crossing the signal line via an insulating film is formed at each intersection of the signal line and the short-circuiting conductive film. The signal lines are connected by irradiating a laser beam, and affixed to another substrate, and then filled with a liquid crystal material. A method for manufacturing a liquid crystal display device, characterized by insulating.