JPH05173150A - Manufacture of liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the manufacture of the liquid crystal display element which shorten the manufacture time of the liquid crystal display element while avoiding defects such as plural liquid crystal injection openings of a cell, a decrease in the sealing strength due to a large diameter, and an irregularity in substrate-to-substrate distance. CONSTITUTION:This manufacture of the liquid crystal display element is equipped with a liquid crystal cell assembling process wherein a liquid crystal cell consisting of two opposite arranged electrode substrates, an inside seal 3 having plural holes 4 and 5 for injecting liquid crystal into the substrates, and an outside seal 1 which is positioned between the substrates and outside the inside seal 3 and has a single hole 2 for injecting the liquid crystal is assembled, a liquid crystal injecting process wherein the liquid crystal is injected into the cell through the single hole 2 of the outside seal of the cell and the holes 4 and 5 of the inside seal 3, and a cell unnecessary part removing process wherein the outer peripheral part from the position of the inside seal 3 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a plasma display device, an LED display device, a CRT device, a liquid crystal display device and the like have been used as a display device, but recently, a laptop computer has been utilized by taking advantage of low power consumption and thin and light weight. It has become popular to be installed. As a display device for such computer equipment, a large display area has been demanded, and a large-area liquid crystal display device of about 10 inches has been commercialized at present.

A plan view and a sectional view of such an existing liquid crystal display cell are shown in FIG. 4 and FIG. 5, respectively. A conventional method for manufacturing a liquid crystal display element will be described with reference to these drawings.

A lower transparent electrode (18) is formed on a lower glass substrate (16), a lower alignment film (19) is applied and dried on the lower transparent electrode (18), and an adhesive containing a spacer having a small diameter (several μm) is used. , A seal part (17) having an injection port (22) for injecting liquid crystal is formed. On the other hand, on the upper substrate (15),
The upper transparent electrode (20) is formed in advance, the upper alignment film (21) is applied and dried on the upper transparent electrode (20), and this is bonded to the lower substrate having the seal portion formed thereon.

Next, a liquid crystal is vacuum-injected into the cell. That is, the cell and the liquid crystal reservoir containing the liquid crystal are put in a decompression tank, and the decompression tank is decompressed by using a vacuum pump, and the injection port (22) of this cell is set to the liquid crystal in the liquid crystal reservoir also put in the decompression tank. The liquid crystal is injected into this cell by returning the pressure reducing tank to the atmospheric pressure in the immersed state.

After that, the injection port (22) is sealed with an adhesive or the like.

In such a liquid crystal display cell, it is general that one injection port for injecting liquid crystal is provided. However, with the increase in size of the cell, there is a disadvantage that the time required to inject the liquid crystal is long at one location.
That is, in such a conventional liquid crystal display cell, for example, 10
In the case of a large-area panel of about inch, the time required for vacuum injection takes about 4 hours, resulting in a very low manufacturing yield.

Therefore, in order to improve such a reduction in manufacturing yield, it has been conventionally proposed to increase the number of injection ports provided in the seal portion of the liquid crystal cell or to increase the diameter of the injection ports. Has been done, but in this case,
There is a concern that the seal may be peeled off due to the decrease in the strength of the seal due to the increase in the opening area of the injection port, or the distance between the two substrates may become non-uniform and the display quality may deteriorate.

[0009]

SUMMARY OF THE INVENTION According to the present invention, it is possible to shorten the time required for manufacturing a liquid crystal display device while avoiding the above-mentioned drawbacks due to a plurality of liquid crystal injection ports of a cell and an increase in diameter. A display element manufacturing method is provided.

[0010]

[Means for Solving the Problems] Two electrode substrates arranged to face each other, an inner seal having a plurality of holes for injecting liquid crystal into the substrate, and an outer seal of the inner seal, which is between the substrates. A liquid crystal cell assembling process, wherein the liquid crystal cell is composed of an outer seal having a single hole for injecting liquid crystal, and a single hole of the outer seal of the cell through a plurality of holes of the inner seal. A method for manufacturing a liquid crystal display element, comprising a liquid crystal injecting step of filling a liquid crystal into the cell and a cell unnecessary portion removing step of removing an outer peripheral portion from the inner sealing position of the cell.

[0011]

According to the present invention, by adopting the double seal of the outer seal having the large-diameter inlet and the inner seal having the large number of inlets, the strength is increased and the distance between the two substrates is increased. The liquid crystal injection time can be shortened while maintaining the uniformity.

[0012]

1 is a plan view of an embodiment of a cell structure used in a method of manufacturing a liquid crystal display device according to the present invention, and FIG.
3 is a sectional view of the cell structure of FIG. 3, and FIG. 3 is a conceptual diagram showing a liquid crystal injection step in the present invention.

In these figures, (9) and (12)
Shows the lower glass substrate and the upper glass substrate, respectively, similar to the glass substrates (16) and (15) of the conventional apparatus of FIGS. 4 and 5. This lower glass substrate (9) is laminated with a lower transparent electrode (10) made of aluminum and a lower alignment film (11) made of polyimide.
Similarly, the upper transparent electrode (13) made of aluminum and the upper alignment film (14) made of polyimide are laminated on one of the upper glass substrates (12).

The liquid crystal display cell of the present invention is different from the conventional cell in the seal structure during the liquid crystal injection process. This seal structure will be described below.

In these figures, (1) is an outer seal portion sandwiched between the two substrates (9) and (12), for example, an adhesive such as an epoxy resin mixed with a spacer having a particle diameter of 5 μm. Is used. (2) is an outer injection port provided at a corner of the outer seal portion (1). (3) is the same as the outer seal portion (1), and both substrates (9) (1
2) The inner seal part sandwiched between the inner seal part and the inner seal part, which is located inside the outer seal part (1), and the same spacer mixed adhesive can be used. (4) and (5) are two inner injection ports, one on each side of the inner seal portion (3) facing each other, that is, two in total.

Further, FIG. 1 (6) shows a display area surrounded by the inner seal portion (3), and liquid crystal display is performed in this area (6).

The manufacturing method of the present invention using the cell having the above-described seal structure will be described below in the order of steps.

(I) Cell assembly step [see FIGS. 1 and 2]: A lower transparent electrode (10) is formed on a lower glass substrate (9), and a lower alignment film (11) is applied and dried thereon. To do.
Next, the inner seal portion (3) and the outer seal portion (1) are formed by printing on the substrate (9). At this time, the two independent portions of the inner seal portion (3) lacking the print pattern become the inner inlets (4) and (5), and the outer seal portion (1).
One portion lacking the printed pattern of is the outer inlet (2). The outer seal portion (1) thus formed
The opening area of the single outer injection port (2) is set to several times that of the conventional cell as shown in FIG. The opening area of each of the inner injection ports (4) and (5) of one inner seal portion (3) is set to the same level as that of the conventional cell as shown in FIG. The decrease in strength is extremely small.
Moreover, since the strength decrease due to the inner seal portion (3) itself is compensated to a large extent by the presence of the other outer seal portion (1), the cooperation of both seal portions (1) and (3) causes The cell strength is significantly improved compared to the single seal structure of.

On the other hand, the upper glass substrate (12) is also similarly
An upper transparent electrode (13) and an upper alignment film (14) are sequentially formed.

Two such glass substrates (9) (1
2) are attached so that the respective electrode installation sides are on the inside. At this time, both substrates (9) and (12) are bonded and fixed by the seal portions (1) and (3) interposed between these substrates,
The liquid crystal display cell is completed.

(Ii) Liquid crystal injecting step [see FIG. 3]: The liquid crystal display cell of FIG. 1 and FIG. 2 as described above is placed in the decompression tank (24) together with the liquid crystal reservoir (23) in which liquid crystal is stored. In this state, the decompression tank (24) is decompressed to 0.1 Toor using a vacuum pump (not shown). As a result, the air in the liquid crystal display cell is exhausted from the inlet (4) (5) of the inner seal and the inlet (2) of the outer seal.

The outer inlet (2) of the liquid crystal display cell whose air has been exhausted in this way is immersed in the liquid crystal in the liquid crystal reservoir (23), and in this state, the pressure in the pressure reducing tank (24) is brought to atmospheric pressure. Restore. As a result, the liquid crystal is rapidly injected into the cell from the outer injection port (2) of the cell having a large opening area, and the liquid crystal is diverted to the two inner injection ports (4) and (5) of the inner seal to divide the cell. It is even introduced inside.

As described above, when the opening area of the outer injection port (2) is made sufficiently large, it can be considered that the injection speed of the liquid crystal becomes substantially equal to that when the outer seal portion (1) is not provided. Therefore, in this embodiment, since the number of the inner injection ports (4) and (5) is set to two, the injection speed of the liquid crystal becomes twice that of the conventional cell, and the time spent in the liquid crystal injection process can be halved.

(Iii) Unnecessary part removing process [see FIGS. 1 and 2]: After the liquid crystal is injected into the entire cell in the above liquid crystal injecting process, the upper glass substrate cutting line is cut on the upper glass substrate (12) by the scriber. (7) is drawn, and similarly, a lower substrate cutting line (8) is drawn on the lower glass substrate (9). Next, the upper glass substrate (12) is cut along the upper glass substrate cutting line (7), and the lower glass substrate (9) is cut along the lower substrate cutting line (8) by a break machine. Then
Remove the outside.

The lower substrate (9) exposed by the process
The upper transparent electrode (10) forms an external terminal region (hatched portion in FIGS. 1 and 2), and a signal line for liquid crystal drive signal input is formed by connecting means such as a zebra connector or a conductive adhesive. Be combined.

(Iv) Sealing step [see FIGS. 1 and 2]: injection port (4) for the inner seal exposed by the unnecessary portion removing step
(5) is sealed with an epoxy adhesive or the like made of the same material as the seal parts (1) and (3) to complete the cell.

[0027]

According to the present invention, by adopting the double seal of the outer seal having the large-diameter inlet and the inner seal having the large number of inlets, the strength of the cell is increased and the reliability is increased. At the same time, the liquid crystal injection time is shortened and the yield is improved.

[Brief description of drawings]

FIG. 1 is a cell plan view showing an embodiment of the present invention.

FIG. 2 is a cell cross-sectional view showing an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a liquid crystal injection process of the present invention.

FIG. 4 is a cell plan view showing a conventional technique.

FIG. 5 is a cell cross-sectional view showing a conventional technique.

[Explanation of symbols]

1: Outer seal part 13: Upper transparent electrode 2: Outer injection port 14: Upper orientation film 3: Inner seal part 15: Conventional cell upper substrate 4: Inner injection port 16: Conventional cell lower substrate 5: Inner injection port 17 : Conventional cell seal part 6: Display area 18: Conventional cell injection port 7: Upper substrate cutting line (solid line in FIG. 1) 19: Conventional cell lower alignment film 8: Lower substrate cutting line (broken line in FIG. 1) ) 20: upper transparent electrode of conventional cell 9: lower glass substrate 21: upper alignment film of conventional cell 10: lower transparent electrode 22: injection port of conventional cell 11: lower alignment film 23: liquid crystal reservoir 12: upper glass Substrate 24: Decompression layer

Claims (1)

[Claims] 1. A pair of electrode substrates arranged to face each other, an inner seal having a plurality of holes for injecting liquid crystal into the substrate, and a space between the substrates and located outside the inner seal, A liquid crystal cell assembling step of assembling a liquid crystal cell comprising an outer seal having a single hole for injecting liquid crystal, the inside of the cell from a single hole of the outer seal of the cell through a plurality of holes of the inner seal A method of manufacturing a liquid crystal display device, comprising: a liquid crystal injection step of filling liquid crystal into the cell; and a cell unnecessary portion removal step of removing an outer peripheral portion from the inner sealing position of the cell.