JPS62195623A - Sticking method for spacer material - Google Patents

Abstract

PURPOSE:To manage the sticking of a spacer material with uniform spraying density without leaving dirt on a board by irradiating ultrasonic waves to the mixed solution of the spacer material, boiling the mixed solution and dipping the board into the mixed solution. CONSTITUTION:An electrode is formed on the board 15 and an orientation film is formed on the electrode to obtain a dispersion tank 11 for forming a liquid crystal cell. Then, the spacer material is mixed to obtain the mixed solution 13 and the solution 13 is agitated and irradiated by ultrasonic waves so that the spacer material is uniformly dispersed in the mixed solution 13. Subsequently, the mixed solution 13 stored in the dispersion tank 11 is boiled by a heater 21 to maintain the uniform dispersion status of the spacer material. Then, the board 15 is dipped into the boiled mixed solution 13 by a lift 19 through a suspending means 17 so that the spacer material spraying surface is vertical to the liquid surface of the mixed solution 13. After the temperature of the board 11 has reached the boiling temperature of the mixed solution 13, the board 15 is lifted up from the mixed solution by the lift 19. At that time, only the spacer material is left on the surface of the board 11 and uniformly dispersed and stuck to the surface of the board 11 and isopropyl alcohol prevents the board 11 being dirtied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of attaching a spacer material to a substrate, which is used to maintain a constant distance between the substrates of a single-function device, particularly a liquid crystal cell.

(Prior Art) There are various functional elements that are constructed by arranging two substrates facing each other with a constant distance of I'l+. - For example, there is a liquid crystal cell constructed by placing a liquid crystal between two substrates placed opposite each other. The spacing between the substrates of this liquid crystal cell is closely related to vE in its display characteristics, and uneven substrate spacing can cause variations in response speed, contrast, and other characteristics between pixels of the liquid crystal cell, and may cause variations in light This may cause interference drafts to occur. Therefore, in order to obtain good display characteristics, it is necessary to keep the spacing between the substrates of the liquid crystal cell accurate and uniform.

For this reason, we have developed a structure in which spacer materials of fixed dimensions, such as spherical particles made of mechanical or organic materials and glass fibers having a cylindrical shape, are scattered between the substrates to maintain a constant substrate spacing. Liquid crystal cells have been proposed.

Conventionally, various methods have been proposed for manufacturing this type of liquid crystal cell in order to evenly spread and adhere the spacer material. The first method is to spray a liquid in which spacers are dispersed onto the substrate, thereby dispersing and adhering the spacer material (for example, JP-A-58-194015). As a method, the substrate is placed in an atmosphere in which a dispersion liquid containing spacers is vaporized or in a gas in which spacers are uniformly dispersed, and unlike the first method, only the spacer material is sprinkled onto the substrate. (e.g., JP-A-54-85580, JP-A-58-156,920), or as a third method, spacer materials with the same electrical polarity are electrically attracted to a charged substrate. A method of dispersion and adhesion using electrical repulsion between materials (for example, JP-A-59-172628)
There is.

(Problem to be solved by the invention) However, in general, spacer materials tend to aggregate due to the influence of surface energy, and especially spacer materials such as Microvar (trade name) made of organic materials have extremely high cohesiveness. It was difficult to obtain a uniform distribution density without IM gathering the spacer material.

In the first method, by using a liquid in which spacers are dispersed in an organic solvent, the spacer material aggregates when the organic solvent evaporates from the substrate surface, resulting in uniform dispersion. This is thought to be the cause of poor orientation.

Further, if Freon is used instead of the organic solvent, these drawbacks can be eliminated, but Freon is expensive, and furthermore, the effects of Freon on the working environment and the human body cannot be overlooked.

In addition, in the first and second methods, temperature and humidity '! #
Due to the impact, it was difficult to manage the dispersed mobara.

In the third method, a high voltage is applied to the charged electrode when the charged electrode is brought into contact with the substrate to adsorb the spacer material, which makes it easy to attract not only the spacer material but also dust. The distribution density tends to be uneven due to the influence of environmental conditions.

Generally speaking, the first, second and third methods all had the problem of large losses in packaging and increased equipment costs.

In view of the problems of the conventional method mentioned above, the purpose of this invention is to
A spacer material that does not leave any dirt on the substrate, allows for easy control of uniform distribution density, and allows for the deposition of spacer materials using a simple method without the need for costly equipment as in the past. The object of the present invention is to provide a method for applying the same.

(Means for Solving the Problems) In order to achieve this object, the method for adhering a spacer material of the present invention includes a step of irradiating ultrasonic waves to a liquid mixed with a spacer material, and a step of irradiating this mixed liquid with boiling water. a step of immersing a substrate for forming an Ia, an active element, such as a liquid crystal cell, into the mixed liquid, and a step of lifting the substrate from the mixed liquid after the temperature of the substrate reaches the temperature of the mixed liquid. It is characterized by

When selecting a liquid to mix the spacer material, it is important that the liquid has the property of easily dispersing the spacer material, and in the case of a liquid crystal cell, the boiling point (or volatilization temperature) of the liquid crystal orientation of the alignment film provided on the substrate ( The temperature should not impair the property of controlling the alignment of liquid crystal molecules; the specific gravity should be equal to or slightly lower than that of the spacer material; the wettability with the alignment film should be high and the material should not be repelled by the alignment film; and the substrate surface. It is best to determine this by taking into account that it has a substitution effect that replaces the moisture that adheres to the top.

Considering these points, alcohol-based liquid is preferable as the liquid to be mixed with the spacer material.

(Function) According to such a configuration, since the liquid mixed with the spacer material is irradiated with ultrasonic waves, the liquid mixed with the spacer material is agitated and the spacer material is uniformly dispersed in the liquid mixed with the spacer material. By elevating this mixed liquid, a uniformly dispersed state of the spacers is maintained. Next, the substrate is immersed in the mixed liquid, and after the substrate temperature reaches the boiling point of the mixed liquid, the substrate is pulled up, so that the substrate surface wet with the mixed liquid and the spacer material is evenly dispersed. The spacer material is uniformly distributed and adhered to. At the same time, since the temperature of the liquid mixed with the spacer material and the substrate have reached the boiling point of the mixed liquid, the liquid evaporates from the substrate without leaving, for example, stain-like dirt on the alignment film, which may cause poor alignment.

As a result, the spacer material is uniformly dispersed and sprayed on the substrate surface without being affected by temperature or humidity (uniform 1-patterning density is obtained), and no stains are left on the alignment film. It spreads and adheres without any problem.

- The density of spacer dispersion is determined by the mixing ratio of spacers and liquid and the pulling speed of the substrate. Regarding the pulling speed of the substrate, the higher the pulling speed of the substrate, the higher the density of spacer scattering becomes, and the slower the pulling speed of the substrate, the lower the spreading density of spacers becomes.

(Example) Hereinafter, an example in which the present invention is applied to a liquid crystal cell will be described with reference to the drawings. It should be noted that Figure 1 only schematically shows each component to the extent that this invention can be understood.
The dimensions, shapes, and arrangement relationships of each component are not limited to the illustrated example.

FIG. 1 is an explanatory diagram of a method for applying a spacer material according to this embodiment.

In FIG. 1, reference numeral 11 indicates a dispersion tank (for example, a glass beaker) in which a liquid 13 containing a spacer material is stored, and the liquid 13 is made of an aqueous medium such as isopropyl alcohol mixed with a spacer material at a predetermined mixing ratio. .

15 indicates a substrate for forming a liquid crystal cell which is immersed in isopropyl alcohol, and this substrate 11 has transparent IjlJt.
Orientation treatment has been applied to the polar ox.

! Reference numeral 7 indicates a means for hanging the substrate 11, and the substrate 11 is locked at an end of the hanging means 17.

Reference numeral 19 denotes a substrate elevator, and the substrate 11 is immersed in the mixed liquid 13 by the elevator 19 via the hanging means 17, and is lifted out of the mixed liquid 13.

In addition, 21 is a heating 8f for heating and boiling the mixed liquid.
One stage shows, for example, a heater.

First, an ITO electrode is provided on a glass substrate, and an alignment film (HL-1100 manufactured by Hitachi Chemical) is formed on this electrode and rubbed to obtain a substrate 11 for forming a liquid crystal cell.

Next, 20 ml of a spacer material (product name: Microbar, manufactured by Mitsui Toatsu) is mixed into 1 fL of isopropyl alcohol to obtain mixed liquid 13.

Next, the mixed liquid 13 is stirred and irradiated with ultrasonic waves to uniformly disperse the spacer material in the mixed liquid 13. This ultrasonic irradiation is necessary to effectively and uniformly disperse highly cohesive spacers.

Next, the mixed liquid 13 stored in the dispersion tank 11 is boiled by the heater 21. This boiling makes it possible to maintain uniform dispersion of the spacer material.

Next, the substrate is immersed in the mixed liquid 13 boiled by the elevator 19 via the hanging means 17 in such a manner that the surface on which the spacer material is spread is perpendicular to the liquid level of the mixed liquid 13. After the temperature of the substrate 11 reaches the boiling point of the mixed liquid 13, the substrate is lifted from the mixed liquid 13 by an elevator 18 at a constant speed of 2 cm/cm.
Raise it in Sec. At this time, the isopropyl alcohol and the spacer material adhere to the surface of the substrate 11, but the isopropyl alcohol immediately evaporates, leaving only the spacer material on the surface of the substrate 11. The spacer material is uniformly dispersed and adhered to the surface of the substrate 11, and the isopropyl alcohol does not leave stains in the form of stains on the alignment film of the substrate 11.

After this, the liquid crystal cell is manufactured as usual, but the substrate 11
The spacer material adhered to the entire surface of the liquid crystal cell does not interfere with subsequent processes, and the adhered spacer material can be easily removed by washing with water after the liquid crystal cell is completed.

In this example, the spacer material could be uniformly dispersed at a scattering density of approximately 30 particles/ml without causing any visible agglomeration of the spacer material, and the appearance of stains, which may be the cause of poor orientation, was achieved. No dirt was left on the substrate 11.

Although the embodiments described above are explained using specific numerical conditions and materials, the present invention is not limited thereto, and the numerical conditions can be arbitrarily set according to the desired dispersion density. In addition, the mixed liquid for the spacer material is not limited to inpropyl alcohol, but also alcohol-based liquids and other liquids.The spacer material is not limited to Microvar (product name W1), but may also be glass fiber, inorganic materials, or organic materials. A spacer material comprising particles of or other suitable material may be used.

(Effects of the Invention) J: As is clear from the above explanation, according to the method of applying spacer material of the present invention, the spacer material can be spread without leaving any dirt on the substrate surface E, for example, in the case of a liquid crystal cell. This does not result in poor orientation.

In addition, the spacer material distribution density can be controlled more easily than before without being affected by temperature and humidity, and the spacer material distribution density can be more uniform than before.

As a result, there is no longer a need for expensive equipment as in the past, and the installation cost can be reduced compared to the past.

In addition, the method of this invention pulls the substrate immersed in the mixed liquid.
This is a very simple method that is carried out by hanging the substrates, and by using a jig such as a cartridge for suspending the substrates, the spacer material can be easily distributed to a large number of substrates in a batch process.

Furthermore, the present invention is particularly effective when applied to spacer materials with high cohesiveness, such as Microvar (trade name).

[Brief explanation of drawings]

FIG. 1 is a detailed explanatory diagram of the present invention. DESCRIPTION OF SYMBOLS 11... Dispersion tank, 13... Spacer material mixed liquid 15... Substrate, 17... Hanging means 19... Substrate lifting device, 21... Heating means. /f'亦'' sheet weight 13: Mataha ξ-゛su'oogP> 5kon, λ婢L1
5: Base 17: Suspension 1,100゛乎tχ tq'yl - ice

Claims (1)

[Claims] (1) When attaching a spacer material to the substrate of a functional element formed by facing each other with a spacer material interposed between the substrates, a step of irradiating the spacer material mixed liquid with ultrasonic waves and boiling the mixed liquid A method for depositing a spacer material, the method comprising the steps of: immersing a substrate in a boiling mixed liquid; and lifting the substrate from the mixed liquid after the substrate temperature reaches the temperature of the mixed liquid. .