JPS60142325A - Manufacture of liquid crystal display element - Google Patents

Abstract

PURPOSE:To improve the reproducibility in sealing and to improve the yield by pressing excessive liquid crystal out of a liquid crystal cell and sealing the cell in said state. CONSTITUTION:An adhesive layer 2 having a liquid crystal injection hole 3 at one terminal is formed at the circumferential edge of the liquid crystal cell 1 as a necessary liquid crystal display element. One panel consisting of numbers of liquid crystal cells 1 is supplied and drawn out through upper and lower pressure rollers 4 and 5 for rolling provided to a base and auxiliary rollers 6 and 7 for holding provided at a specific vertical interval to press excessive liquid crystal out of the injection hole 3, which is then sealed with an ultrasonic wave between ultrasonic wave horns 8 and 9. A gap agent used for a flexible film liquid crystal panel only consists of a rod-shaped or spherical high-polymer elastic body. For example, styrene beads, divinyl benzyne copolymer, optical fiber, etc., are usable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a liquid crystal display element having a structure in which a liquid crystal is sandwiched between flexible substrates.

[Prior art]

In liquid crystal display elements with a cell structure in which liquid crystal is sandwiched between flexible substrates such as plastic, the gap between the two substrates (
As a method for controlling the gap thickness (gap thickness), a method has been developed in which after the liquid crystal is filled in, the substrate is squeezed with a jig such as a roller or a flat plate to push out the excess liquid crystal and achieve a predetermined thickness (
(Japanese Patent Application No. 58-133134), when the clamping pressure is released, the board returns to its swollen state due to the elasticity of the plastic, and at this time, air may be sucked in and bubbles may be generated within the panel, resulting in poor display quality. was there.

〔the purpose〕

The purpose of the present invention is to improve the yield during sealing by preventing the inclusion of air bubbles in a manufacturing method that continuously processes the gap control and sealing processes of liquid crystal display elements using flexible film substrates. shall be.

〔composition〕

The liquid crystal cell is formed by sealing the liquid crystal d together with the gap control agent C between the upper and lower substrates a and b, as shown in FIG.
Gear control of liquid crystal cells using plastic substrates is
Unlike conventional glass substrates, the substrate itself has flexibility, so when manufacturing large-area panels, the substrate is simply folded in two directions from above and below.
It is not possible to perform the process satisfactorily by simply holding the plate between two flat plates. For this reason, as mentioned above, a method was developed in which the excess liquid crystal inside the cell was pushed out of the system by squeezing the substrate with rollers, etc. However, although gap control is achieved with this method, it is difficult to remove the pressure after applying pressure. Air flows in from the liquid crystal enclosure 1, causing air bubbles to enter the liquid crystal display, resulting in poor display quality and a decrease in yield.

The present invention eliminates this drawback, and an example of an apparatus for carrying out the method of the present invention will be explained with reference to the drawings. In FIGS. It is a cell, and an adhesive layer 2 is formed on the periphery of the cell, with one end serving as a liquid crystal injection port 3.

This liquid crystal cell 1 is supplied as one panel formed by a large number of them, and includes upper and lower pressing rollers 4, 5 provided on a base that can be rolled down, and an auxiliary roller 6 for holding provided with a predetermined gap between the upper and lower sides. After the liquid crystal is pulled out to the right side of the figure through the space between .
The injection port 3 is ultrasonically sealed between an ultrasonic horn 8 and a die 9, which are also provided on the base.

The operating sequence of the above device will be explained with reference to FIG. 3. Liquid crystal is injected into the liquid crystal cell 1 in advance through the liquid crystal injection port 3 by a well-known method. This injection is carried out, for example, by leaving the liquid crystal cell in a vacuum system to reduce the pressure inside the cell, and then introducing the liquid crystal injection port of the liquid crystal cell into the liquid crystal, bringing the liquid crystal to atmospheric pressure, and the pressure between the liquid crystal pressure and the cell internal pressure. Liquid crystal is injected and filled into the cell by utilizing the difference and capillary action so that a surplus liquid is generated.

(1) This liquid crystal cell 1 is set in the state shown in FIG. 3(A). In this case, the pressure roller 4 is in a raised state and no pressure is applied.

(2) The liquid crystal cell 1 is pulled out in the direction of the arrow, and the extra liquid crystal is pushed out by the pressure auxiliary rollers 4 and 5.

((B) of the same figure) (3) At the same time as the above-mentioned suppression ends, the pressure roller 4 descends and presses the liquid crystal injection port 3 to prevent the liquid crystal from flowing out. In this state, the ultrasonic horn 8 descends. Seal is done. (Figure 1 (C)) After filling the liquid crystal in this way, the entire panel is assembled as shown in Figure 1 (A).
It is cut by mechanical cutting, laser cutting, etc. at the position indicated by the symbol IO, and is divided into individual pieces.

The gap agent used in the flexible film liquid crystal panel of the present invention may be any material as long as it is made of a rod-shaped or spherical polymeric elastic body. For example, styrene beads,
Divinylbenzene copolymer, optical fiber, etc. are used. Also, the size of the gap agent is 6 to 15μ for granular ones.
Particles classified to m ± 0.5 μm, rod-shaped particles with a diameter of 6
Optical fibers with a length of ~15 μm and a maximum length of 200 μm are preferable. Further, it is sufficient that the hardness of the gap agent is such that it does not damage the ITO, for example, 123 Rockwell hardness (JIS K 7202).

If the degree of pressurization is too strong, the gap agent may be destroyed, the ITO may be damaged, or the gap agent may be removed from the system along with the liquid crystal, so 1 to 10 kg/ClJ is appropriate, but it depends on the material and raw material. There is also.

As the substrate, a polymer film 1 made of polyester, polycarbonate, borisulfone, polyethersulfone, modified polyester, etc. can be used.

Furthermore, when carrying out the present invention, gap control can be made more uniform by mixing a gap agent into the sealing part to make the thickness of the sealing part uniform.

〔effect〕

As described above, the present invention pushes out the excess liquid crystal from inside the liquid crystal cell and seals it in that state, thereby preventing air from flowing in and producing a product that is thinner than conventional liquid crystal cells. It is extremely efficient as it eliminates the frequent decrease in yield due to the generation of bubbles during sealing, and improves yield with good reproducibility during sealing.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a liquid crystal cell, FIGS. 2(A) and 2(B) are a plan view and a side view showing an example of an apparatus for carrying out the method of the present invention, and FIGS. 3(A) to (C) are FIG. 2 is a side view showing the operating sequence of the above device. Circular, ■ is a liquid crystal cell, 2 is an adhesive layer, 3 is a liquid crystal injection port,
4 and 5 are pressure rollers, and 8 is an ultrasonic horn. Patent applicant Rico Co., Ltd. − Representative patent attorney Toshiaki Ikeura

Claims (1)

[Claims] (1) When manufacturing a liquid crystal display element with a structure in which a gap agent and liquid crystal are sandwiched between substrates made of flexible films, the above-mentioned After injecting liquid crystal from the liquid crystal injection port,
This liquid crystal cell is passed between pressure rollers to remove excess liquid crystal from the system, and at the same time, the pressure roller presses the liquid crystal injection port to prevent liquid crystal from flowing out, and the liquid crystal injection port is sealed by ultrasonic sealing etc. A method for manufacturing a liquid crystal display element, which comprises sealing the element.