JP2000047230A - Production of liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for production which is capable of suppressing the generation of air bubbles at the migration of liquid crystals under a reduced pressure and lessening the contamination of the device and the loss of the liquid crystals. SOLUTION: This process for production comprises in pouring the liquid crystals 11 onto a hollow groove 10a of a liquid crystal tray 10 in (a), then introducing this liquid crystal tray 10 into a chamber 12 as shown in (b) and completely replacing the atm. air in the chamber 12 with nitrogen. The liquid crystals are rested >=5 minutes, preferably for about 15 minutes in this state. The inside of the chamber 12 is thereafter evacuated to a vacuum state as shown in (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal device, and more particularly, to a liquid crystal injection step.

[0002]

2. Description of the Related Art Conventionally, a manufacturing line of various liquid crystal devices has been provided with a liquid crystal injection step for injecting liquid crystal into a liquid crystal cell. In the liquid crystal injection step, in a normal liquid crystal display panel manufacturing line, a liquid crystal cell (empty cell) and a liquid crystal container containing liquid crystal are put in a chamber, and the pressure is reduced. The liquid crystal is brought into contact with the liquid crystal injection port, and thereafter, the pressure inside the chamber is increased, so that the liquid crystal is introduced into the cell from the liquid crystal injection port using the internal / external pressure difference.

There are various methods for injecting liquid crystal into a liquid crystal cell. For example, a groove 10a is formed on the surface of a liquid crystal tray 10 which is a liquid crystal container made of synthetic resin as shown in FIG.
There is a method in which a liquid crystal is put in the concave groove 10a, put in the chamber 12, decompressed, and the liquid crystal injection port of the liquid crystal cell is immersed in the liquid crystal 11 on the liquid crystal tray 10 in the chamber 12. . A method of dropping liquid crystal using a dispenser near a liquid crystal injection port of a liquid crystal cell in a vacuum chamber is also used.

[0004]

However, in the above-described liquid crystal injecting step, in the process of shifting the liquid crystal from normal pressure to reduced pressure, air contained in the liquid crystal is blown out and bubbles are generated. There are problems that the dispenser for dropping liquid crystal in the apparatus and the peripheral portion of the liquid crystal container are contaminated, and the liquid crystal overflows from the liquid crystal container (such as a liquid crystal tray) to reduce the amount of liquid crystal in the liquid crystal container. For example, when the liquid crystal tray 10 shown in FIG. 2 is used, a large number of bubbles are generated from the liquid crystal 11 filled in the concave groove 10a, and the diameter is 1 to 1.
A bubble 11a of about 2 mm exists on the liquid crystal surface for a while, and when the bubble 11a disappears, the liquid crystal spills out of the tray from the groove 10a or splashes around the liquid crystal tray 10. If the loss of the liquid crystal from the concave groove 10a is too large, the liquid crystal tray 10 may need to be drawn out of the chamber 12 again and refilled with the liquid crystal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a manufacturing method capable of suppressing the generation of bubbles when transferring a liquid crystal under reduced pressure, thereby reducing the contamination of the device and the loss of the liquid crystal. It is to provide a method.

[0006]

In order to solve the above-mentioned problems, the present invention takes a measure of disposing an atmosphere other than the inert gas atmosphere into the liquid crystal after disposing the liquid crystal in the inert gas atmosphere for a predetermined time. A method of manufacturing a liquid crystal device, wherein the pressure around the liquid crystal is reduced, and then the liquid crystal is injected into a liquid crystal cell. According to this means,
The generation of bubbles can be suppressed in the process of reducing the pressure around the liquid crystal, so that contamination of the inside of the device due to the liquid crystal and loss of the liquid crystal can be reduced. Entangling an atmosphere other than the inert gas atmosphere into the liquid crystal means that the liquid crystal is arranged or moved quietly without greatly shaking the liquid crystal or transferring the liquid crystal.

Here, the inert gas is preferably nitrogen.

It is preferable that the time for disposing the liquid crystal in an inert gas atmosphere is 5 minutes or more. By setting the arrangement time to 5 minutes or more, the effect of suppressing the generation of bubbles can be obtained in most cases.

Further, the liquid crystal is put in a predetermined liquid crystal container in a state having an open liquid level, and after the liquid crystal container is placed in an inert gas atmosphere, the liquid crystal is transferred without being transferred from the liquid crystal container. It is preferable that the pressure around the liquid crystal container is reduced, and then the liquid crystal contained in the liquid crystal container is injected into a liquid crystal cell. In this case, it is preferable that the liquid crystal is poured into the liquid crystal container in an inert atmosphere.

[0010] Possible process contents include a step A of pouring the liquid crystal into the liquid crystal container, a step B of placing the liquid crystal container in an inert gas atmosphere for a predetermined time, a step C of reducing the pressure around the liquid crystal container, and a step of discharging the liquid crystal from the liquid crystal container. This is Step D for introducing the liquid crystal cell. At this time, the atmosphere around the liquid crystal and the liquid crystal container may be replaced with an inert gas before step A or before step B. Step B
Therefore, the liquid crystal container may be once taken out of the atmosphere other than the inert gas atmosphere, but it is necessary to prevent the atmosphere from being caught in the liquid crystal by giving a large fluctuation to the liquid crystal or transferring the liquid crystal. Conversely, even after step B, any inert gas may be involved in the liquid crystal. For example, in an inert gas atmosphere, the liquid crystal may be shaken, or the liquid crystal may be transferred to another container or device.

[0011]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings. The inventor of the present application has conducted various experiments in order to solve the above-described problems. As a result, after pouring the liquid crystal onto the concave groove 10a of the liquid crystal tray 10, the liquid crystal was once left under a nitrogen atmosphere for a predetermined time, It has been found that the generation of bubbles from the liquid crystal can be significantly reduced or almost completely eliminated by evacuating and reducing the ambient atmosphere of No. 10.

FIG. 1 shows the flow of the above operation. 1A, a liquid crystal 11 is poured into a concave groove 10a of a liquid crystal tray 10, and then the liquid crystal tray 10 is introduced into a chamber 12 as shown in FIG. Replace completely. In this state, it is left (rested) for 5 minutes or more, preferably for about 15 minutes. It is considered that the time to be left in the nitrogen atmosphere depends on the relationship (ratio) between the open liquid level of the liquid crystal 11 placed in the liquid crystal tray 10 and the liquid crystal volume. In the illustrated concave groove 10a, the groove depth is about 0.5 mm and the groove width is about 6 mm, and the liquid level of the liquid crystal 11 rises due to the surface tension of the liquid crystal. It becomes about 0.0 mm. Under these conditions, the standing time under a nitrogen atmosphere is 5
Minutes or more, and a sufficient effect was obtained in about 15 minutes. Even if left for 15 minutes or more, the result was almost the same. The installation state of the liquid crystal varies depending on the shape of a liquid crystal container such as a liquid crystal tray. In addition, since the open liquid level of the liquid crystal may be adjusted depending on the components of the liquid crystal, the installation state may be set intentionally. For example, in the case of a liquid crystal containing a highly volatile component, the open liquid level is set smaller than the liquid crystal volume in order to minimize the loss of the volatile component, and the liquid crystal is set in a state where volatilization is difficult. Therefore, when the open liquid level becomes smaller with respect to the volume, it is necessary to lengthen the standing time under a nitrogen atmosphere.

After the liquid crystal tray 10 is left in a nitrogen atmosphere by the above-described method, the interior of the chamber 12 is evacuated to a vacuum state as shown in FIG. At this time,
Conventionally, a large number of bubbles were generated from the liquid crystal 11 on the liquid crystal tray 10 and bubbles were formed so as to cover the entire surface of the liquid crystal 11. On the other hand, in the present embodiment, almost no bubbles were generated.
In particular, when allowed to stand for about 15 minutes, generation of air bubbles was not observed at all. The effects of the present embodiment are shown in Table 1 below in comparison with the conventional case where the evacuation of the chamber 12 is started directly from the atmosphere, when the chamber 12 is left after being replaced with dry air, and then left. .

[0014]

[Table 1]

In Table 1, the standing time is a period of time after the liquid is poured into the liquid crystal tray and left standing until the start of evacuation under a predetermined atmosphere (any of air, dry air and nitrogen). In Table 1, X indicates a state where generation of many bubbles was observed, Δ indicates a state where generation of bubbles was suppressed but not completely eliminated, and ○ indicates a state where generation of bubbles was not observed at all. I have. With respect to other conditions, the same liquid crystal tray described above was used, and the amount of liquid crystal poured was the same.

In the above method, the liquid crystal 11 is poured in the air, but the liquid crystal 11 is also poured in a nitrogen atmosphere, so that the standing time in the nitrogen atmosphere can be reduced. However, also in this case, it is necessary to secure a slight standing time (for example, 2 to 3 minutes) in a nitrogen atmosphere.

In the above-described method, the atmosphere is replaced with nitrogen in the chamber 12, and after leaving in the nitrogen for a predetermined time, the gas is evacuated as it is. However, a preliminary leaving chamber other than the chamber 12 is provided. The atmosphere may be replaced with nitrogen, and the gas may be moved into the chamber 12 already replaced with nitrogen before exhausting. In addition, the chamber 12
The inside may be replaced with nitrogen, and the liquid crystal may be poured into the liquid crystal container in the chamber 12 and left as it is for a predetermined time to start evacuation.

In the above method, the air is exhausted as it is after standing, but if a sufficient standing time is secured,
Thereafter, before the start of evacuation, it may be exposed to the atmosphere or the like, for example, when moving to a chamber. Further, even when the gas is exhausted after being moved from the preliminary storage chamber to the chamber as described above, the inside of the chamber may not be replaced with nitrogen and may be open to the atmosphere. That is, after the liquid crystal is allowed to stand for a predetermined time as described above, even if the liquid crystal is once brought out into the atmosphere, a certain effect can be obtained as long as the liquid crystal is not greatly shaken, such as by transferring the liquid crystal. Conversely, if it is in nitrogen or another inert gas, it may be shaken or transferred.

In the above method, the case where nitrogen is used as the inert gas is described. However, in addition to nitrogen, an inert gas such as helium, neon, or argon, or a mixed gas of two or more inert gases is used. May be used.

As a manufacturing apparatus for realizing the various methods described in the present embodiment, it is preferable to provide a preliminary storage chamber for previously holding a liquid crystal container such as a liquid crystal tray in a nitrogen atmosphere. In this case, a preliminary storage chamber is provided at a liquid crystal supply position or a liquid crystal supply line for supplying a liquid crystal container in the chamber, separately from a main line for introducing a liquid crystal panel having an empty liquid crystal cell into the chamber. A liquid crystal panel is introduced into the chamber from the main line, and a liquid crystal container is introduced from the preliminary storage chamber. After the chamber is evacuated, liquid crystal is injected into the chamber.

[0021]

As described above, according to the present invention, it is possible to suppress the generation of bubbles in the process of decompressing the periphery of the liquid crystal, thereby reducing contamination inside the device by the liquid crystal, loss of the liquid crystal, and the like. be able to.

[Brief description of the drawings]

FIGS. 1A to 1C are schematic process explanatory views for explaining a main part of a method for manufacturing a liquid crystal device according to the present invention.

FIGS. 2A and 2B are a schematic explanatory view showing a conventional state of a liquid crystal injection step at the time of manufacturing a liquid crystal device, and a schematic perspective view showing the shape of a liquid crystal tray used in the liquid crystal injection step.

[Explanation of symbols]

 Reference Signs List 10 liquid crystal tray 10a groove 11 liquid crystal 11a foam 12 chamber

Claims (4)

[Claims] After arranging a liquid crystal in an inert gas atmosphere for a predetermined period of time, the pressure around the liquid crystal is reduced without involving an atmosphere other than the inert gas atmosphere in the liquid crystal.
A method for manufacturing a liquid crystal device, comprising injecting the liquid crystal into a liquid crystal cell. 2. The method according to claim 1, wherein the inert gas is nitrogen. 3. The method for manufacturing a liquid crystal device according to claim 1, wherein the time for disposing the liquid crystal in an inert gas atmosphere is 5 minutes or more. 4. One of claims 1 to 3
In the item, the liquid crystal is placed in a state having an open liquid level in a predetermined liquid crystal container, and after disposing the liquid crystal container in an inert gas atmosphere for a predetermined time, without transferring the liquid crystal from the liquid crystal container, Decompress the periphery of the liquid crystal container,
Thereafter, the liquid crystal contained in the liquid crystal container is injected into a liquid crystal cell.