JPH0682772A - Matrix type liquid crystal display device and its manufacture - Google Patents

Abstract

PURPOSE:To provide a matrix type liquid crystal device easily conformable to the machine kind change of superposing machine, and allowing the re- superposition after cutting an opposed base. CONSTITUTION:In a method for manufacturing a matrix type liquid crystal display device in which a circuit bard 1 having a signal line formed thereon is positioned and adhered to an opposed base 2 having a light shielding film 4 formed thereon, the positioning is performed by fitting an alignment mark 5 formed on the light shielding film 4 of the opposed base 2 by laser irradiation to the alignment mark 5 formed on the circuit board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type liquid crystal display device and a method of manufacturing the same, and more particularly to a matrix type liquid crystal display device in which formation of alignment marks for aligning a circuit board and a counter substrate is improved. Regarding the manufacturing method.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view showing a circuit board and a counter substrate which are the main parts of a conventional matrix type liquid crystal display device. In the figure, 1 is a circuit board on which a liquid crystal driving circuit and a signal line are formed, 2 is a counter substrate on which a counter electrode is formed, 3 is a display region which is an assembly of a plurality of display pixels formed therein, 4 is a light-shielding film formed so as to surround the periphery of the display region 3, 6 is a signal line formed on the circuit board 1, and 9a and 9b are for strictly aligning the circuit board 1 and the counter substrate 2 with each other. Alignment mark provided, 7
Is a region of the counter substrate (hereinafter referred to as a use region) that remains as a product after cutting after stacking, and 8 is a bent portion provided in a part of the signal line 6.

Next, a method of manufacturing the liquid crystal display device will be described. In the liquid crystal display device, the circuit board 1 and the counter substrate 2 are aligned with each other by using the alignment marks 9a and 9b.
Is manufactured by cutting so as to become the use area 7.

The alignment marks 9a and 9b used for the above purpose are usually formed of Cr or the like in the step of forming a signal line and a counter electrode.

Positioning when superimposing is performed on both substrates 1 within the visual field of the alignment mark monitor camera.
The alignment marks 9a and 9b on 2 are aligned.

Japanese Unexamined Patent Publication No. 1-40492 discloses a method of aligning an object such as a wafer having a plurality of patterns formed by a step-and-repeat method with a processing apparatus, and is particularly suitable for a step-and-repeat exposure apparatus. However, in the present invention, the alignment can be performed using the above method.

[0007]

Since the conventional alignment marks 9a and 9b are formed by the method as described above, a new mask for the film formation and patterning process is prepared in order to change the formation position. Necessary and costly. Therefore, there is a problem that it is not possible to easily cope with changes in the model of the superposing machine.

Further, since the quality judgment test of the matrix type liquid crystal display device is carried out after the counter substrate 2 is cut into the use area 7, the alignment marks 9a and 9b have already been formed on the counter substrate when the judgment test shows that the defect is bad. Separated from 2. Therefore, in the liquid crystal display device having the alignment marks 9a and 9b formed by the conventional method, the liquid crystal display device determined to be defective is again separated into the circuit board 1 and the counter substrate 2 and subjected to a predetermined process. After that, it is impossible to carry out the overlay again, and there is a problem that the defect repair of the matrix type liquid crystal display device is impossible.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to easily cope with a change in the model of the stacking machine, and even after the counter substrate 2 is cut into the use area 7, the stacking is performed again. It is an object of the present invention to provide a matrix type liquid crystal display device which can be adjusted and a manufacturing method thereof.

[0010]

A matrix type liquid crystal display device of the present invention comprises a circuit board having a liquid crystal drive circuit and signal lines, a counter electrode for driving liquid crystal, and a display area which is an assembly of pixels. A matrix type liquid crystal display device comprising a counter substrate having a light shielding film formed on the periphery thereof and a liquid crystal layer filled between the both substrates, wherein an alignment mark is formed on the light shielding film of the counter substrate. It is a feature.

Further, according to the method of manufacturing the matrix type liquid crystal display device of the present invention, the circuit board on which the liquid crystal driving circuit and the signal line are formed, the counter electrode for driving the liquid crystal, and the display area which is an assembly of each pixel are surrounded. A method of manufacturing a matrix type liquid crystal display device in which a counter substrate on which a light shielding film is formed is aligned and bonded, and a liquid crystal material is filled between the both substrates, wherein the alignment is performed on the light shielding film of the counter substrate. It is characterized by aligning the alignment mark formed by laser light irradiation with the signal line formed on the circuit board or the alignment mark formed by laser light irradiation on the circuit board.

[0012]

In the present invention, since the alignment mark of the counter substrate is formed on the light shielding film portion formed around the display area by laser light irradiation, the alignment mark can be arbitrarily changed in the light shielding film around the display area. Even if the model of the superposing machine is changed, it can be freely changed without changing the pattern forming mask such as the signal line. Further, the display performance of the display area is not impaired.

On the circuit board on the opposite side, a part of the signal line can be used as an alignment mark, or a mark formed by laser light irradiation or the like where the signal line is not formed can be used as an alignment mark to align the two boards. Accurate alignment can be performed by an ordinary overlay machine using an ordinary alignment method.

Further, according to the present invention, since the alignment mark is formed in the light-shielding film portion around the display area, the alignment mark portion is not removed even after the outer end portion of the circuit board is cut and removed to form the display panel. After that, the substrate can be peeled off and the alignment can be performed again.

[0015]

EXAMPLE An example of the present invention will be described below with reference to FIG. In the figure, 1 is a circuit board on which a liquid crystal driving circuit and signal lines are formed, 2 is a counter substrate on which counter electrodes are formed, and 3 is a display area which is an assembly of a plurality of display pixels formed therein. Reference numeral 4 is a light-shielding film formed so as to surround the periphery of the display region 3, 5 is an alignment mark formed on the light-shielding film 4 by laser irradiation, 6 is a signal line formed on the circuit board 1, and 7 is a matrix. This is a region (use region) of the type liquid crystal display device.

On the circuit board 1, for example, a thin film transistor (hereinafter referred to as TFT) for driving each pixel is formed for each pixel, and the TFTs of each pixel are horizontally and vertically connected by a conductive film to form a signal line 6. It is led out to the end of the circuit board 1. In addition, a counter electrode is formed on the entire surface of the display region 3 on the counter substrate 2 by driving a TFT through a signal line 6 of the substrate 1 to generate a voltage between each pixel and the counter electrode. It is configured to be applied. Both substrates are adhered at regular intervals by a sealing material around the display area of each pixel assembly, the gap is filled with a liquid crystal material, and only the liquid crystal layer of a pixel is displayed depending on the voltage applied between both substrates. It is configured to be. In order to improve the display performance, such as preventing leakage of light to the outside of the display area at the part that is bonded with this sealing material or inside it, a light-shielding film with chromium, aluminum, etc. attached to the counter substrate around the display area that corresponds to the bonded part 4 are formed.

The present invention is characterized in that the light shielding film 4 is irradiated with laser light such as YAG or Xe to form an alignment mark. This alignment mark
As described above, when the circuit board 1 and the counter substrate 2 are overlapped and adhered to each other, the two substrates are aligned so that pixel shift does not occur. For example, a certain signal line of the alignment mark 5 and the circuit substrate 1 is provided. This is performed by aligning the bent portion 8 of the. A part of the signal line may be used on the side of the circuit board, or an alignment mark may be separately formed on the part where the signal line is not present by laser light or the like.

Next, a method of manufacturing the liquid crystal display device will be described.

First, on the circuit board 1, the liquid crystal drive circuit such as a thin film transistor and the signal line 6 are formed by a metal film such as Cr by a usual method. The signal line 6 usually has a width of, for example, 10 to 20 μm, and has a bent portion 8 as shown in FIG. 1, for example, outside the display area.

On the other hand, on the counter substrate 2, a counter electrode for driving a liquid crystal is similarly formed by a transparent conductive film, and a sealing material portion around the display area 3 or the inside thereof is provided with a light shielding film or the like in order to improve display performance. To form. The light-shielding film usually has a width of, for example, 2 to 3 mm and is formed of a thin film of a metal such as chromium.

YAG, Xe are formed on the light-shielding film 4 of the counter substrate 2.
By irradiating a laser beam (not shown) such as the above, a part of the metal film is evaporated to make it transparent to form the alignment mark 5.

As a place where the alignment mark is formed, a place corresponding to the mark on the circuit board 1 is set in advance.

Since the alignment mark 5 on the counter substrate 2 side thus formed is formed in the light-shielding film 4, it does not impair the display performance of the matrix type liquid crystal display device.

After forming the alignment mark 5 on the light-shielding film as described above, both substrates are laminated together with the alignment film which has been subjected to the rubbing treatment by printing a sealing material or the like.

The alignment mark 5 may be formed on the light-shielding film at any point in the above-mentioned step before the superposition.

For the superposition, a superposition machine of the type in which the substrate positions are adjusted by the alignment marks existing on both the substrates is used.

In this embodiment, the pattern of the signal line 6 is used as the alignment mark 5 on the circuit board 1 side, as opposed to the alignment mark formed on the light shielding film of the counter substrate. The alignment is performed by transmitting the signal line 6 from the alignment mark 5 side in the visual field of the monitor camera of the overlay machine. The alignment in the long side direction of the substrate can be performed by aligning the bent portion 8 provided in a part of the signal line 6 with the outer periphery of the light shielding film 4. Furthermore, because of the presence of the bent portion 8, the signal line 6 to be the alignment mark 5 on the circuit board 1 side can be easily discriminated from the signal lines 6.

A matrix type liquid crystal display device is manufactured through the steps of aligning and adhering by such a method, filling a liquid crystal between the both substrates, and adhering a polarizing plate and a light reflecting plate.

Even if the liquid crystal display device is found to be defective after the superposing and pasting (adhesion) of the both substrates 1 and 2, the alignment marks 5 are inside the use area 7 of the counter substrate 2 so that the both substrates are not damaged. After separating 1 and 2 again and subjecting them to a predetermined treatment, it is possible to re-superimpose them. The position, size, etc. of the alignment mark 5 on the counter substrate 2 are not limited to those shown in FIG. 1, but may be freely adjusted according to the specifications of the superposing machine and the pattern of the signal line 6 on the circuit board 2. You can choose.

Although the signal line 6 is used as the alignment mark on the side of the circuit board 1 in the above-described embodiment, a new pattern is provided on the circuit board 1 and the alignment mark is formed by irradiating the pattern with a laser. You may.

[0031]

As described above, according to the present invention, since the formation position and shape of the alignment mark can be arbitrarily formed, it is possible to easily cope with the change of the model of the overlaying machine. Also, when a defect occurs in the matrix type liquid crystal display device, it is possible to repair the defect because the alignment mark can be re-formed and re-registered after separating the circuit board and the counter substrate. You can achieve significant cost reduction.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a substrate portion which is a main part of a matrix type liquid crystal display device of the present invention.

FIG. 2 is an explanatory view showing a substrate portion which is a main part of a conventional matrix type liquid crystal display device.

[Explanation of symbols]

 1 circuit board 2 counter substrate 3 display area 4 light-shielding film 5 alignment mark 6 signal line 8 bent portion

Claims (2)

[Claims] 1. A circuit board on which a liquid crystal drive circuit and signal lines are formed, a counter electrode for driving liquid crystal, and a counter substrate on which a light-shielding film is formed around a display area which is an assembly of each pixel; A matrix type liquid crystal display device having a liquid crystal layer filled between substrates, wherein an alignment mark is formed on a light shielding film of the counter substrate. 2. A liquid crystal drive circuit and a circuit board on which a signal line is formed, and a counter substrate on which a light-shielding film is formed around a display electrode which is a liquid crystal drive counter electrode and an assembly of each pixel are aligned. A method of manufacturing a matrix type liquid crystal display device in which a liquid crystal material is filled between both substrates by adhering to each other, the alignment mark formed on a light shielding film of the counter substrate by laser light irradiation, and the circuit board. A method of manufacturing a matrix type liquid crystal display device, which is performed by aligning a signal line formed on the above or an alignment mark formed by laser light irradiation on the circuit board.