JPS61162025A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To hold precisely the interval of a liquid crystal injection port part, and to shorten a liquid crystal injection time and to improve the reliability of seal by forming spacers fixed on a substrate on the injection port part. CONSTITUTION:A spacer 4 is formed on the liquid crystal injection port part and fixed by an orientation film 2 an a spacer 5 is formed in a sealing material. The interval of the liquid crystal injection port part is held by the spacer 4. Consequently, sealing resin 6 can be entered into the inside of a cell uniformly for a short period, the sealing can be precisely attained and no bubble is generated even after the hardening of the resin 6, so that the reliability of the seal can be improved.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a liquid crystal display element using a flexible substrate such as a plastic film, and in particular, to shortening liquid crystal injection time and improving sealing reliability. <Prior art> In liquid crystal display elements constructed using flexible substrates such as plastic films, maintaining a uniform substrate gap is an important issue, and various methods have been proposed. The most common method that has been devised is to spread spacers between two substrates, but flexible substrates such as plastic films tend to be partially deformed, making it difficult to spread spacers uniformly. If there are no spacers, or even if they are evenly distributed, if the spacers move for some reason and there is a part where the spacers are not properly present, the gap between the two boards will be extremely narrow in that part. or close contact may occur. Such non-uniformity of the gap between the substrates or the close contact between the substrates causes defects and has a negative effect on the display quality. However, if the above-mentioned close contact between the substrates occurs at the liquid crystal injection port, it will cause problems with the liquid crystal injection. Not only does the time required become extremely long, but reliability also decreases because complete penetration of the sealing resin is not achieved.

<Object of the Invention> The present invention has been made in view of the above-mentioned conventional problems, and is directed to flexible substrates such as plastic films! A liquid crystal display element that solves the above-mentioned problems by providing a spacer fixed to a substrate at the liquid crystal injection port to securely maintain the gap in the injection port. It provides:

<Example> Hereinafter, the present invention will be described in detail based on Examples.

This example uses a polyimide-based organic polymer alignment film as an alignment film in a liquid crystal display element using a PET film with a thickness of 100 μm as a substrate, and spherical polymer beads with a diameter of 10 μm as spacers in the precursor solution. and this spacer is added to the precursor solution! At the same time as forming an alignment film, a spacer fixed to the substrate is applied to the inside of the cell and the liquid crystal injection hole of the film substrate using an offset printing machine and baked. ! The spacer distribution at this time was uniform, and the distribution amount was set to be IO spacers/-.

After forming the alignment film, a liquid crystal cell is completed through a rubbing process, a sealing material printing process, a substrate bonding process, etc., and a liquid crystal display element is completed through a liquid crystal injection process, a sealing process, etc.

FIG. 1 fi1 is a plan view of the PET film substrate in this example, l is the PET film substrate, 2 is an alignment film (
3 is a sealing material (thermosetting epoxy sealing material to which the same spacer as the above spacer is added). A liquid crystal cell is completed by stacking the other substrate on this substrate, sandwiching it between 5 m+ glass plates, and press firing.

FIG. 1 (2) is a side view when viewed from the direction of the liquid crystal cell injection port, where l is a PET film substrate, 2 is an alignment film, 3 is a sealing material, and 4 is present in the liquid crystal injection port portion. , a spacer fixed by the alignment film 2, and 5 a spacer present in the sealing material. The spacer 4 maintains a gap at the liquid crystal injection port.

As a comparative example, as shown in FIG. 2 (1), a liquid crystal cell was created using a film substrate in which the alignment film was formed only in the inner part of the cell and no spacer was present in the injection port part.
As shown in FIG. 2 (2), the upper and lower substrates were in close contact with each other at the center of the injection port.

When we measured the liquid crystal injection time in a device with a liquid crystal injection area of 20 m x 60 m, it was 2 minutes in this example, whereas in the comparative example it took 10 minutes for the liquid crystal to completely infiltrate.
I needed a minute.

Furthermore, after injecting the liquid crystal, the sealing material has a viscosity of 5000c.
Modified acrylate UV curing resin of p (at 25℃)!
In this example, as shown in FIG. 3, the sealing resin 6 penetrates into the inside of the cell uniformly and in a short time, and sealing is performed reliably. Even after a reliability test after curing (conditions: 80° C., 95% RH), no bubbles were observed, and the reliability was good. On the other hand, in the comparative example, as shown in FIG. 4, the sealing resin 6 did not penetrate uniformly, the sealing was not reliable, and during the reliability test, air entered from the injection port. , generation of bubbles was observed.

<Effects of the Invention> As is clear from the above explanation, according to the present invention, all of the above-mentioned conventional problems can be solved and the liquid crystal injection time can be reduced. This makes it possible to shorten the time and improve sealing reliability.

[Brief explanation of the drawing]

FIG. 1 fl is a plan view, FIG. 1 (2) is a side view, FIG. 2 fl+ is a plan view, FIG. 2 (2) is a side view, and FIGS. 3 and 4 are plan views. Explanation of symbols 1: PET film substrate, 2: alignment film, 3: sealing material, 4: spacer fixed to liquid crystal injection port by alignment film, 5: spacer present in sealing material, 6: sealing resin . Agent Patent attorney Aihiko Fukushi (and 2 others) Figure 1
(Fig. 3, Fig. 4)

Claims (1)

[Claims] 1. A liquid crystal display element using a flexible substrate, characterized in that a spacer fixed to the substrate is provided at a liquid crystal injection port.