JPS58100122A - Manufacture of liquid crystal cell - Google Patents

Abstract

PURPOSE:To uniformly distribute spacers over the whole display surface without damaging transparent electrodes by scattering the spacers by a spraying method so as to make a cell gap uniform after forming orientation controlling films. CONSTITUTION:Orientation controlling films 4 are formed on the surfacesof upper and lower substrates 1, 2 after forming transparent electrodes 3. A polyimide resin soln. is applied, dried and rubbed with cotton cloth in a certain direction. A glass fiber having a diameer almost equal to a cell gap is cut to 20mum size and used as spacers. It is mixed with an adhesive, and the mixture is applied to the peripheral part of the upper substrate 1 by screen printing. Spacers 8 are distributed on the display area part of the lower substrate 2. A dispersion prepared by dispersing100mg of the same members as the spacers 7 in about 100cc liq. ''Freon '' is applied to the whole surface of the lower substrate 2 by spraying and heated to about 50 deg.C to evaporate the ''Freon '' to dryness. Thus, only the spacers 8 are uiformly scattered over the surface of the substrate 2. Both the substrates 1, 2 are then adhered to each other, and a liq. crystal is injected into the gap to complete a liq. crystal cell.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a liquid crystal cell, and more specifically, in order to keep the gap between the substrates constant, spacer materials are uniformly distributed in the portion that forms the display surface of the liquid crystal cell. Concerning how to do so.

FIG. 1 is a cross-sectional view showing the structure of a conventional liquid crystal cell. 2 is connected to 11 by the adhesive 5. Also, the gap between the two substrates 1 and 2 (hereinafter referred to as the gap)
A spacer 7 having a size substantially equal to the desired cell gap is arranged in the adhesive 5 to keep the cell gap constant.

However, as shown in FIG. 2, this conventional structure tends to have a thin cell gap in the center of the liquid crystal cell. Especially for liquid crystal cells with a relatively large display area and substrate 1.
．． This tendency is remarkable in liquid crystal cells having a thin structure. The uniformity of the cell gap is an extremely important matter for the quality of a liquid crystal cell, and if this is lacking, problems such as response characteristics, Thrennon-Jord characteristics, etc. will vary depending on the cell gap's unevenness. Occur.

Therefore, in the past, the above problem was solved [first, as shown in FIG.
A method has been proposed in which the display area is also placed in the display area.

That is, the spacer material 7 is mixed in advance into a solution of a material constituting the alignment control film 4', such as a polyimide resin, and the solution is applied to the surface of one of the substrates on either side, for example, the upper substrate 1, using a spinner. In this method, the orientation control film 4 is formed by coating the film with a drying agent or the like, drying it, and then rubbing the surface in a certain direction with a cotton cloth or the like. However, the biggest drawback of this method is that in the rubbing operation, not only the spacers 7 scattered on the surface of the upper substrate 1 peel off from the surface of the upper substrate 1 due to the rubbing pressure, but also There is also the problem that the transparent electrode film (not shown) formed on the surface of the substrate 1 is damaged, so it has not been put into practical use.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide a method for uniformly arranging spacers over the entire display surface without damaging the transparent electrode. do.

4 and 5 are partial cross-sectional views showing an embodiment of the present invention. First, after forming the transparent electrode 6 on both the upper substrate 1 and the lower substrate 2, the alignment control film 4 is formed on the surfaces thereof. That is, in this example, a polyimide resin solution is applied using a spinner, dried, and then the surface is rubbed in a certain direction with a cotton cloth.

After that, a glass fiber having a diameter approximately equal to the cell gap is chopped into pieces of about 20 μm in length to be used as a spacer 7, and the spacer 7 is mixed into the adhesive 5, and this is attached to the upper substrate 1. Screen printing is performed around the outer periphery. Then, according to the present invention, spacers 8 are placed in the display area on the lower substrate 2 side. That is, spacers 8 identical to the spacers 7 placed in the adhesive 5 of the upper substrate 1 are placed on the lower substrate 2 side in accordance with the present invention. Approximately 101 parts
Use n9, C! Then, disperse it in about 10cc of Freon liquid, and spray (apply from the second side) the upper surface of the lower substrate 2.

When the substrate 2 is heated to about 50° C. and the Freon liquid is evaporated and dried, only the spacers 8 are uniformly distributed over the entire surface of the lower substrate 2.

Thereafter, the upper substrate 1 and the lower substrate 2 are placed on top of each other, and the sub-substrate 1.2 is bonded. Then, liquid crystal is injected into the gap between the sub-substrates 1.2 and sealed to complete the liquid crystal cell.

In the liquid crystal cell manufactured according to this example, the spacers 8 are uniformly distributed not only in the adhesive 5 but also in the display area, so that the uniformity of the cell gap is improved and the range of the cell gap is ± A liquid crystal cell of 0.5 μm or less was obtained.

In other embodiments, the spacers 7 and 8 may be made of fine alumina powder, plastic balls, etc., and the same effect can be obtained. Further, in the above embodiment, the spacer 8 was dispersed in the Freon liquid, but other dispersion liquids include methyl alcohol, ethyl alcohol, isopropyl alcohol, pure water, etc. It is considered that any liquid that does not dissolve or alter the quality of 4 can be used.

As described above, in order to make the cell gap uniform, the present invention employs a method of dispersing the spacers 8 by spraying after forming the alignment control film 4 as a method of arranging the spacers 8 in the display area of the liquid crystal cell. According to the present invention, it is possible to extremely easily distribute and arrange the spacers 8 evenly in the display area without damaging the transparent electrode 6 as in the conventional example.

[Brief explanation of drawings]

FIGS. 1 to 3 are cross-sectional views showing the structure of a conventional liquid crystal cell, and FIGS. 4 and 5 are partial cross-sectional views showing an embodiment of the manufacturing method of the present invention. 1.2... Substrate 4... Orientation control film 7.8.
・・・・・・・・・Spacer 1st r! A Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] In a method for manufacturing a liquid crystal cell in which a pair of substrates are arranged facing each other, an alignment control film for aligning liquid crystal molecules in a fixed direction is formed on each of the surfaces of the pair of substrates, and then an alignment control film is formed on the surface of at least one of the substrates. A liquid made by dispersing a spacer material such as glass fiber in a dispersion liquid of Freon, methyl alcohol, ethyl alcohol, etc. is spray applied,
A method for manufacturing a liquid crystal cell, which comprises evaporating and drying the dispersion liquid to obtain a state in which the spacer material is scattered on the surface of the substrate.