JPS601608B2 - Display element manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a display element filled with a liquid substance, such as a liquid crystal display element or an electrochromic element used in display devices such as electronic watches, calculators, electronic measuring instruments, and level meters. In particular, it relates to a sealing method.

Conventionally, there have been two methods for sealing an injection port for a liquid crystal substance in a liquid crystal display element: (1) using a low melting point metal, and (2) using an organic adhesive.

Among these, the method (2) of sealing the injection port using solder, which is a method using a low melting point metal, has advantages such as long life and high reliability.

However, in this method, in order to improve the adhesion strength between the solder and the glass, it is necessary to form a two-layer thin film such as a Cr--Au film on the glass substrate, which increases the cost. Furthermore, since a glass paste for sealing is used as the substrate, there is a drawback that high temperature treatment is performed (resulting in a decrease in the orientation of the substrate in the vicinity of the substrate). In view of the above-mentioned disadvantages of (1), methods (2) using organic adhesives have also been widely implemented.

This method uses silicone resin, epoxy resin, fluororesin, acrylic ester resin, etc. as an organic adhesive, and the application is performed using a coating tool such as a microdispenser. However, when this coating method using a microdispenser is used, the coating process takes a long time when producing many liquid crystal display elements. Furthermore, a bulge of the organic resin material is formed on the end face of the glass, resulting in a narrowing of the effective display area and an unsatisfactory appearance. The present invention has been made to solve the above-mentioned conventional drawbacks, and it shortens the coating process time even though an organic adhesive is used to seal the injection port, and makes the height of the resin material at the injection port uniform. The purpose is to

Hereinafter, one embodiment of the present invention will be described in detail using the drawings. FIG. 1 is a plan view of a liquid crystal display element with an injection port on the side, and FIG. 2 is a sectional view of the same side.

In the figure, 1 is two glass substrates, 2 is a liquid crystal, 3 is a seal and a spacer, and 4 is an organic adhesive. Next, a method of sealing the liquid crystal injection port of the display element shown in the figure will be described. Third
The figure is an external perspective view showing the printing state for the injection port, and FIG. 4 is a side view of the same.

I will explain step by step.

{1) Two glass substrates having patterned transparent electrodes are subjected to orientation treatment such as oblique vapor deposition or rubbing.

■ The upper and lower substrates are arranged in a twisted orientation, and the periphery of the two substrates is sealed with an organic adhesive.

At this time, the part that will become the injection port is not sealed. Also, at this time, a comoso transfer process is performed. {3} Inject positive nematic liquid crystal from the injection port, and blow off the excess liquid crystal that protrudes from the injection port with an N2 gun.

(2) A large number of display elements 6 injected with liquid crystal are fixed to a printing table of a screen printing device using a jig.

At this time, all end faces with injection ports of each element are screened 6.
Fix it so that it is facing to the side and on the same plane. This is because if the gap between the end face having the injection port and the screen is not uniform, the printing thickness of the resin will be different. The screen 6 used for printing is made of wear-resistant nylon 66 material with a plain weave opening of 95 mm and stretched on a bias on an aluminum frame.

A diazo-based emulsion is used as the photosensitive emulsion of the plate, and the emulsion thickness is 15 peaks. The plate patterns the portion of the filler that requires sealing. Epoxy resin is used as the printing ink 7. {5' The distance between the inlet end face and the screen 6 is 2
The squeegee 8 used has a shower hardness of 60, and the printing pressure is weakened to print an epoxy resin layer with a hardness of 30.

9 is an ink returner.

A semi-automatic flat screen printing machine is used as the printing machine, which can move the printing table up and down greatly depending on the size of the element.
Before printing, the plate descends while rotating in the direction a, and after printing, the plate rises in the direction b, and the printed matter and the plate are separated. Here is the hole of Ichikawa pattern. {6) After printing, the resin is thermally cured by heating.

FIG. 5 is a plan view of a liquid crystal display element in which the injection port is located on the front substrate (or the rear substrate), and FIG. 6 is a side sectional view of the same.
In this figure, the same parts as in FIGS. 1 and 2 are designated by the same reference numerals. 7th
The figure shows the injection port on the front (back) as shown in Figures 5 and 6.
FIG. 8 is an external perspective view of a state in which a large number of liquid crystal display elements on the substrate surface are fixed to the printing table 11, and FIG. 8 is an external perspective view showing a state in which the injection port is sealed on the substrate.

The method of sealing the injection port of the substrate shown in the same figure is the same as that shown in FIGS. 3 and 4, except that ultraviolet curing epoxy resin is applied to the injection port using a screen using a Svechamatic semi-automatic printing machine. It is covered with printing.

The printing resin is cured using a mercury lamp. Other conditions are the same as in the sealing method described above. In the above embodiments, as the display element other than the liquid crystal display element, it can be applied to ECD, and as the organic adhesion agent used for sealing, epoxy resin, fluororesin, acrylic ester resin, and silicone resin can be used. .

Note that as the type of resin, a thermosetting type and an ultraviolet curing type can be used, but an ultraviolet curing type resin having a long pot life is superior for screen printing. As explained above, according to the present invention, the liquid crystal injection port is sealed using a screen printing method using an organic adhesive, so the adhesive application time is extremely short, and the injection port sealing resin is The height can be made uniform.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the liquid crystal display element, FIG. 2 is a sectional view from the same side, FIG. 3 is an external perspective view showing the printed state of an embodiment of the present invention, and FIG. 4 is a side view of the same side. FIG. 5 is a plan view of the liquid crystal display element, FIG. 6 is a side sectional view of the same, FIG. 7 is an external perspective view of a state in which a large number of cells are fixed, and FIG. 8 is a printing screen of another embodiment of the present invention. It is an external perspective view showing a state. In the figure, 4: organic adhesive, 5: cell, 6: screen, 7
:Printing ink, 8: Squeegee, 9: Ink returner. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. A method for manufacturing a display element in which a liquid substance is sealed between at least two substrates, the step of injecting the liquid substance between the two substrates through an injection port, and the injection port is bonded with an organic adhesive. A method for manufacturing a display element, comprising: a step of coating the organic adhesive using a screen printing method; and a step of curing the organic adhesive.