JPH0895065A - Manufacture of liquid crystal display cell - Google Patents

Abstract

PURPOSE: To provide manufacturing method of a liquid crystal display cell in which spacers scattered on a transparent substrate are uniformly arranged. CONSTITUTION: A transparent substrate 1 formed with an orientation film is placed on the suceptor 9 of a spacer scattering device 4, water/methyl alcohol/ isopropyl alcohol are mixed in the ratio 16/1/3 in a mixing liquid tank 8, spacers 12 are mixed in this mixed liquid, the mixed liquid containing the spacers 12 is atomized by an atomizer 7, and the spacers 12 are scattered on the transparent base plate 1. By using such mixed liquid, the spacers can be uniformly scattered, and a liquid crystal display cell of favorable display characteristic can be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display cell, and more particularly to a technique for spraying particulate spacers arranged between alignment films provided on opposite surfaces of a pair of transparent substrates. Pertain.

[0002]

2. Description of the Related Art A liquid crystal display device used as a display for electronic equipment includes a liquid crystal display cell in which liquid crystal is sealed between two transparent substrates. In this method of manufacturing a liquid crystal display cell, generally, two substrates each having a transparent electrode and an alignment film formed on a transparent substrate made of glass or resin are prepared, and a large number of spacers ( It is manufactured by spraying spherical particles of glass, resin, etc. with a certain particle size, and then sticking the other substrate through the sealing material and enclosing the liquid crystal between the facing alignment films inside the sealing material. There is. Here, as a method of spraying spacers, a spacer is mixed with a liquid or water of freon and sprayed on the surface of a transparent substrate (alignment film) with an atomizer. At this time, the atmospheric temperature is raised so that the CFCs and water do not adhere to the substrate surface, and the CFCs and water are evaporated so that only the spacers adhere to the substrate surface.

[0003]

However, in the conventional method using CFCs or water as a solvent, the spacers made of a resin-based material have poor dispersibility, and the spacers are lumped on the substrate. Often sprayed on.
Therefore, it is difficult to uniformly dispose the spacers on the substrate, and there is a problem that the space between the substrates cannot be properly maintained and the display characteristics of the liquid crystal display cell are deteriorated. Further, CFC-1 used as a solvent here is CFC-1 which is generally used as a propellant or a refrigerant.
Since these are designated as specific CFCs such as 1, CFC-12, and CFC-114, their use is desired to be avoided. The problem to be solved by the present invention is to take any means to uniformly dispose spacers and obtain a liquid crystal display cell having good display characteristics safely in both the natural environment and the manufacturing process. There is a point.

[0004]

Therefore, according to the invention of claim 1, after spacers are scattered on one transparent substrate of a pair of transparent substrates, the other transparent substrate is placed on the one transparent substrate. In the method of manufacturing a liquid crystal display cell in which the spacers are overlapped with each other via the spacers, the solution is to spray the spacers in a state of being mixed with a mixed liquid of alcohol and water. The invention according to claim 2 is characterized in that a spacer is mixed and sprayed with a liquid in which water and plural kinds of alcohols are mixed. . Further, the invention according to claim 3 is characterized in that the alcohol is selected from the group consisting of methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol and isomers thereof.

[0005]

In the present invention, by mixing the spacer with a mixture of alcohol and water, the alcohol acts as a dispersion medium, so that the dispersibility of the spacer can be enhanced. That is, since alcohol has a hydroxyl group —OH, it has high hydrophilicity, and since it has good wettability with resin spacers, it has the effect of wetting the surfaces of the spacers and preventing the spacers from forming lumps. Also, by mixing with water, it has an action of preventing ignition and explosion of alcohol. In addition, methyl alcohol, ethyl alcohol,
By using a relatively low molecular weight lower alcohol such as propyl alcohol or butyl alcohol, the vapor pressure can be set to a high level, which has the effect of enhancing the dispersibility of the spacer in the sprayed state. By selecting and using a plurality of alcohols and their isomers, the dispersibility of the spacer due to the volatility of the mixed liquid can be adjusted. If a plurality of different alcohols such as methyl alcohol and ethyl alcohol are mixed as water to form a dispersion medium mixture, the use ratio of methyl alcohol harmful to the human body is suppressed without lowering the necessary dispersibility. be able to.

[0006]

EXAMPLES The details of the method for producing a liquid crystal display cell according to the present invention will be described below with reference to examples. First, in this embodiment, as shown in FIG. 2A, a transparent electrode 2 made of ITO or the like is formed on the upper surface of one transparent substrate 1 made of glass or resin.
To form a pattern. Next, the alignment film 3 is formed on the upper surface of the transparent substrate 1 including the transparent electrodes 2. Further, a transparent electrode and an alignment film are formed on the other transparent substrate as in the case of the transparent substrate 1.

Next, the transparent substrate 1 prepared as described above is put into the spacer spraying device 4 shown in FIG.
Spacers are scattered on the alignment film 3 of FIG. The spacer spraying device 4 includes a constant temperature bath 6 having a heater 5 as shown in the figure, and an atomizer 7 disposed above the constant temperature bath 6.
And a liquid mixture tank 8 for supplying a liquid mixture containing a particulate spacer in a solvent to the atomizer 7. A susceptor 9 on which a transparent substrate can be placed and supported is disposed in the constant temperature bath 6 immediately below the nozzle 7A at the bottom of the atomizer 7. In addition, inside the constant temperature bath 6, the mist guide plate 1 that surrounds the nozzle 7A of the atomizer 7 and spreads toward the susceptor 9 side to guide the generated mist to the susceptor side.
0 is formed. The atomizer 7 includes means for applying ultrasonic vibration to the mixed liquid, for example. The atomizer 7 and the mixed liquid tank 8 are connected via a mixed liquid supply pipe 11.

In the present embodiment, the mixed liquid tank 8 described above is
A spacer is mixed with a mixed solution of water, methyl alcohol and isopropyl alcohol. The mixing ratio of the mixed liquid is, for example, water: methyl alcohol: isopropyl alcohol = 16: 1: 3. The spacer used in this embodiment is made of resin, glass, or the like, for example, 10
The particles are spherical particles having a diameter of about μm, and the compounding amount with the above mixed liquid is set according to the number of transparent substrates on which spacers are dispersed at one time and the dispersion density (number of spacers / cm ² ). The boiling points of methyl alcohol and isopropyl alcohol are as low as 64.7 ° C and 82.4 ° C, respectively, and since the alcohol content in the mixed solution accounts for 20% of the mixing ratio, the vapor pressure of the mixed solution is high and the spacer Has the effect of increasing dispersibility. At this time, by operating the heater 5 associated with the spacer spraying device to raise the temperature in the constant temperature bath 6, the atomized mixed liquid can be more easily evaporated, so that the dispersibility of the spacer can be further improved. it can. That is, as shown in FIG. 1, the atomized mixed liquid including the spacers 12 discharged into the constant temperature bath 10 heated to a proper temperature from the nozzle 7A of the atomizer 7 together with the mixed liquid is methyl alcohol, Vaporize in the order of isopropyl alcohol. The alcohol adhering to the periphery of the spacer 12 is vaporized and becomes vapor in this way, so that the spacers are separated from each other. The reason for mixing water here is that it has a function of preventing ignition and explosion of alcohol. By mixing water in this way, it was possible to realize an alcohol mixed solution having a flash point and an explosion point that could withstand use.

Further, since methyl alcohol and ethyl alcohol are mixed at a ratio of 1: 3, the use ratio of methyl alcohol is small and the effect on the human body is almost negligible. In this embodiment, the transparent substrate 1 shown in FIG.
When the spacers 12 drop onto the (alignment film), the spacers 12 are appropriately separated from each other, and the in-plane uniformity of the dispersion density can be secured. FIG. 2B shows
The transparent substrate 1 in which the spacers 12 are uniformly arranged on the alignment film 3 is shown.

Next, a sealant (not shown) is formed by printing on the periphery of the upper surface of the transparent substrate 1 on which the spacers 12 are arranged in this manner except the liquid crystal injection port forming region. Then, the other substrate is attached onto the transparent substrate 1 via a sealing material. As for the other substrate, as shown in FIG. 2C, a transparent electrode 14 made of ITO or the like is formed on the lower surface of the transparent substrate 13.
And the alignment film 15 is formed similarly to the transparent substrate 1. After that, liquid crystal is injected through the liquid crystal injection port, and then the liquid crystal injection port is sealed to complete the manufacture of the liquid crystal display cell.

In the present embodiment, a mixed liquid of water, methyl alcohol and isopropyl alcohol was used as a mixed liquid for mixing the spacers 12, but a group consisting of methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol and their isomers are used. By using one or more kinds of alcohol selected from the group and mixed with water,
It is possible to improve the dispersibility of the spacer. Further, the mixing ratio of these mixed liquids can be appropriately changed in consideration of the dispersibility of the spacer and the volatility of the mixed liquid. Further, the shape and size of the spacer can be appropriately changed according to the standard of the liquid crystal display cell to be manufactured.

[0012]

As is apparent from the above description, according to the present invention, the spacers can be uniformly dispersed on the transparent substrate,
Therefore, the distance (gap) between the substrates can be made uniform, and there is an effect of realizing a liquid crystal display cell with improved display characteristics. In addition, the mixed liquid in which the spacers are mixed does not adversely affect the environment and the human body, and the spacers can be uniformly sprayed even if CFC is not used or the use ratio of methyl alcohol is reduced.

[0013]

[Brief description of drawings]

FIG. 1 is an explanatory view of a spacer spraying device used in an example of a method for manufacturing a liquid crystal display cell of the present invention.

FIG. 2A to FIG. 2C are cross-sectional views of essential parts showing the steps of the embodiment of the present invention.

[Explanation of symbols]

 1 transparent substrate (one substrate) 2 transparent electrode 3 alignment film 4 spacer spraying device 13 transparent substrate (other substrate)

Claims (3)

[Claims] 1. A method of manufacturing a liquid crystal display cell, comprising: spraying spacers on one transparent substrate of a pair of transparent substrates, and then stacking the other transparent substrate on the one transparent substrate via the spacers. A method for manufacturing a liquid crystal display cell, comprising spraying the spacer in a state of being mixed with a mixed liquid of alcohol and water. 2. The method for manufacturing a liquid crystal display cell according to claim 1, wherein the alcohol is a mixture of plural kinds of alcohols. 3. The alcohol is methyl alcohol,
The method for producing a liquid crystal display cell according to claim 1, wherein the method is selected from the group consisting of ethyl alcohol, propyl alcohol, butyl alcohol and isomers thereof.