JPH0378728A - Production of liquid crystal panel - Google Patents

Abstract

PURPOSE:To obtain a gap uniform over the entire part of the panel by forming a liquid crystal into fine particles, spraying the fine particles to a substrate to previously uniformly disperse the particles, thereby preventing the movement of spacers at the time of sticking of the substrates. CONSTITUTION:A sealing material 2 is provided in the peripheral edge part of at least one substrate of two sheets of the substrates 1, 6 provided with transparent electrodes and the liquid crystal 3 is sprayed in the form of the fine particles to at least one substrate. Two sheets of the substrates 1, 6 are then stuck to each other in a vacuum by disposing the surfaces provided with the transparent electrodes to face each other. The sealing material 2 is thereafter cured to seal the liquid crystal. Namely, the liquid crystal 3 is uniformly dispersed and the movement of the spacers 11 when the substrates are stuck to each other is prevented by spraying the liquid crystal 3 in the form of the fine particles to the substrate. The gap uniform over the entire part of the liquid crystal panel is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a liquid crystal panel used in liquid crystal display devices such as calculators and word processors.

Conventional technology Liquid crystal display devices are used in watches, calculators, word processors, etc. due to their characteristics such as thinness, light weight, and low power consumption.Moreover, with the recent development of information-related equipment, displays with large display capacity and large display area are becoming popular. Demand is increasing.

The liquid crystal panel used in this liquid crystal display device has a structure as shown in FIG. 3, and includes substrates 1 and 6 on which transparent electrodes are formed.
A liquid crystal 3 is sealed with a sealing material 2 between the two. These substrates 1 and 6 are kept at a constant interval (hereinafter referred to as a gap) by a spacer 11, and generally 5 to 1
It is 0 μm.

The manufacturing method is as follows: - Vacuum injection in which the liquid crystal 3 is brought into contact with an injection port provided in a part of the sealing material 2 of the panel in a vacuum chamber, and then the chamber is returned to the atmosphere and the panel is filled with the liquid crystal 3. There are two methods: (1) a method in which the substrate 1 on which the sealing material 2 and spacer 11 have been formed in advance and the substrate 6 on which the liquid crystal 3 has been dropped are bonded together in a vacuum (shown in FIGS. 4a and 4b). (No. 60-229104).

Problems to be Solved by the Invention However, such a manufacturing method has the following problems.

In the conventional manufacturing method (2), as the display area of the liquid crystal panel increases, it takes a long time to fill the liquid crystal (for example, 30 minutes or more for a 12-inch liquid crystal panel).

On the other hand, when the conventional manufacturing method (2) is adopted, the liquid crystal 3 can be filled at the same time as the substrates 1.6 are bonded together, so that the liquid crystal 3 can be filled in a shorter time than the manufacturing method (2). However, when they are bonded together, the spacer 11 also moves at the same time as the liquid crystal 3 spreads from the dropping point as shown in Figure 4.
1 is not evenly distributed on the panel. As a result, LCD 3
A difference of about 0.5 μm occurs in the gap between the dropping point and the non-dropping point. With conventional twisted nematic type liquid crystal panels, the gap accuracy was only around ±0.5 μm, so this was not much of a problem, but with super twisted nematic type liquid crystal panels, which are in high demand these days, the requirement for gap accuracy is ±0.1 μm. Due to the harshness, gap unevenness is likely to occur.

In order to prevent the spacer movement phenomenon described above, it is sufficient to increase the number of drops and to make the interval between the dropping points very small. However, it takes time to drop a large number of drops, and since the amount of each drop is small, it is very difficult to control the amount of drops.

The present invention aims to solve these problems and provide a uniform gap over the entire liquid crystal panel.

Means for Solving the Problems To achieve this object, the present invention provides a sealing material on the peripheral edge of at least one of two substrates provided with transparent electrodes, and a sealing material on at least one of the substrates. After spraying liquid crystal in the form of fine particles, the two substrates are bonded together in a vacuum with their transparent electrode facing surfaces facing each other, and then the sealing material is cured to seal the liquid crystal.

Effect According to the present invention, since the liquid crystal is sprayed onto the substrate in the form of fine particles, the liquid crystal is uniformly dispersed, there is no movement of the spacer when the panels are bonded together, and a uniform gap can be obtained over the entire panel.

Further, in this method, a spacer is mixed into the liquid crystal in advance (thereby, the spacer dispersion step can be reduced).

EXAMPLE Hereinafter, a method for manufacturing a liquid crystal panel according to an example of the present invention will be explained with reference to the drawings.

(Example 1) Polyimide resin is printed as an alignment film on the transparent electrodes of a pair of glass substrates 1 and 6 on which transparent electrodes are formed as shown in FIG. omission). Thereafter, an ultraviolet curable resin is printed on the periphery of one glass substrate 1 as a sealing material 2, and glass beads having a particle size of 6 μm are sprinkled as spacers 11 on the other glass substrate 6. Next, as shown in Fig. 1, liquid crystal 3 is sprayed onto the glass substrate 1 at intervals of 10111111 using a liquid crystal sprayer, and then the pair of glass substrates 1 and 6 are placed on the transparent electrode surface in vacuum as shown in Fig. 2. Paste them together so that they are facing each other. Thereafter, the sealing material 2 is cured by irradiating ultraviolet rays to form a liquid crystal panel.

Here, the liquid crystal sprayer used in this example has a structure as shown in FIG.
It is sprayed in the form of fine particles using the nitrogen gas ejected in step d.

Further, the distance between the nozzle 5 of this liquid crystal sprayer and the glass substrate 1 was set to 2 am.

When liquid crystal is dropped as in the conventional method, spacers gather between the dropping points, causing gap unevenness. However, in the liquid crystal panel manufactured according to this example, the liquid crystal is uniformly dispersed as shown in Figure 2, so the spacer does not move as the liquid crystal spreads, and the gap accuracy is ±0.1 μm or less over the entire panel. Yes, and no gap unevenness was observed.

(Example 2) Descriptions of steps similar to those in the first embodiment will be omitted.

The spacer spraying step was omitted, glass beads with a particle size of 6 μm were mixed with 0.2 wt% liquid crystal as the spacer 11, and the mixture was sprayed at 10+nm intervals using a liquid crystal sprayer as shown in Fig. 1, and the rest was the same as in the first embodiment. A liquid crystal panel is produced in the same manner.

Also in the liquid crystal panel manufactured according to this example, the gap accuracy was ±0.1 μm or less, and no gap unevenness was observed.

In addition, in the liquid crystal sprayer, the pressure of high-pressure scum is 2 kg /
The distance between the liquid crystal sprayer and the glass substrate 1 should be cl. 2 cm, and the spraying interval is 10 mm, but it is not limited to these, and it is desirable to set appropriately depending on the shape, size, gap accuracy, and liquid crystal material of the liquid crystal panel to be manufactured.

Further, in this embodiment, the liquid crystal is sprayed at intervals, but it may be sprayed continuously.

Effects of the Invention As described above, according to the present invention, by spraying the liquid crystal into fine particles onto the substrates and uniformly dispersing them in advance, it is possible to move the spacer when bonding the substrates together. A uniform gap can be obtained throughout.

Furthermore, by mixing spacers into the liquid crystal in advance, the spacer dispersion process can be reduced.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the liquid crystal spraying process in an embodiment of the present invention, Figures 2a and b are explanatory diagrams of the substrate bonding process in an embodiment of the invention, and Figure 3 is an explanatory diagram of the liquid crystal panel The cross-sectional views and FIGS. 4a and 4b are explanatory diagrams showing the substrate bonding step in the conventional manufacturing method (2). 1.6...Glass substrate, 2...Sealing material, 3...Liquid crystal, 4...Syringe, 5
... Air nozzle, 7.8 ... Transparent electrode, 9,10 ... Alignment film, 11 ... Spacer

Claims (2)

[Claims] (1) A sealing material is provided on the periphery of at least one of the two substrates provided with transparent electrodes, and after spraying liquid crystal in the form of fine particles onto at least one substrate, the transparent electrodes of the two substrates are A method for manufacturing a liquid crystal panel, which comprises bonding surfaces facing each other in a vacuum, and then hardening the sealing material to seal the liquid crystal. (2) The method for manufacturing a liquid crystal panel according to claim 1, wherein a spacer having a function of maintaining the distance between the two substrates is mixed into the liquid crystal.