JPS61267027A - Formation of liquid crystal oriented film - Google Patents

Abstract

PURPOSE:To eliminate entirely the possibility of the discoloration and damage of a liquid crystal oriented film and to reduce the time for treatment by using the dielectric itself as a target and irradiating an ion beam thereon to sputter so that the liquid crystal oriented film exhibiting uniform orientation is obtd. CONSTITUTION:A ZrO2 plate sized 30cmX5cm vertically and horizontally is supported as a dielectric material 3 of a target by a supporting member 5 and an electrode substrate 7 which is laminated with a film 6 consisting of a polyamic film, i.e., the precursor of polyimide, on the electrode side surface and is sized 30cmX30cm vertically and horizontally is supported by a supporting member 8. The inside of a treatment chamber 1 is then set at 1X10<-4>Torr via a vacuum evacuation system 2 and Ar<+> is irradiated on the dielectric material 3 by an ion gun 4 to irradiate the particles of the sputtered material 3 for 10 seconds onto the surface of the film 6 so that the island-shaped discontinuous films consisting of ZrO2 are formed on the surface thereof. More specifically, the film 6 is exposed between the island-shaped ZrO2 films. The substrate 7 is finally taken out of the chamber 1 and is housed into a heating chamber, where the polyamic acid laminated on the substrate 7 is heated and is polymerized to polyimide.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for forming a liquid crystal alignment film laminated on an electrode substrate of a liquid crystal display element.

(Prior Art) Conventionally, as a method for forming this type of liquid crystal alignment film, a method is known in which the surface of an electrically insulating heat-resistant synthetic resin coating such as polyimide is subjected to a rubbing treatment. The coating may peel off, or if dust or the like is attached to the surface of the synthetic resin coating or the cloth used to rub it, the surface of the coating may be scratched. However, since it is difficult to perform a rubbing treatment, it is difficult to form a large-area liquid crystal alignment film.

(Problems to be Solved by the Invention) In order to solve the inconvenience described in ml, the patent application (1) filed at the same time by the applicant of the present application provides an island-like dielectric material on the surface of an electrically insulating heat-resistant synthetic resin coating. We proposed a method for forming a liquid crystal alignment film that consists of forming a discontinuous film by oblique incidence sputtering, but it is difficult to form a liquid crystal alignment film that shows more uniform alignment and can form a liquid crystal alignment film with less deterioration in a short time. Proposals on methods are desired.

(Means for Solving the Problems) The present invention aims to provide a method for forming a liquid crystal alignment film that meets the above-mentioned needs. A method for forming a liquid crystal alignment film comprising forming an island-shaped discontinuous film of a dielectric material by oblique incidence sputtering, characterized in that the dielectric material itself is used as a target and sputtering is performed by irradiating it with an ion beam. do.

Examples of the electrically insulating heat-resistant synthetic resin film that forms the dielectric island-like discontinuous film include polyimide, polyamide, polyurea, etc. Polyimide has extremely excellent high electrical insulation, heat resistance, and electrochemical properties. It is preferable because it has physical stability.

The dielectric material formed on the island-like discontinuous film is l'02, T.
ie□, Cr2O,, CuO, Aj! 20. , Sin,
, etc., and the present invention uses the dielectric itself as a target and irradiates it with an ion beam of Ar'' or the like using an ion gun to sputter onto the film.

The island-shaped discontinuous film can be formed by direct sputtering on an electrically insulating heat-resistant synthetic resin film such as polyimide, or it can be formed on an electrically insulating heat-resistant synthetic resin film such as polyamic acid, which is a precursor of polyimide. It may be formed by sputtering on a synthetic resin precursor coating and then completing the polymerization of the precursor, thereby forming it on the resulting heat-resistant synthetic resin coating.

The coating surface of the electrically insulating heat-resistant synthetic resin or its precursor is positioned relative to the target so that the sputtered particles are obliquely incident on the coating surface at an angle of approximately horizontal to 45°. preferable.

Sputtering is generally performed at a vacuum level of 1 x 104 to 1 x 10"
'5 to 30 minutes using an ion gun under conditions of around Torr.
Do this for about seconds.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

The drawing shows an example of an apparatus for carrying out the method of the present invention, and 1 indicates a processing chamber, and the processing chamber 1 is connected to an external vacuum pump or other evacuation system 2 to adjust the internal vacuum degree. It is free.

In addition, in the processing chamber 1, an ion beam irradiating a plate-shaped dielectric material 3 such as ZrO2 as a target with an ion gun 4 such as a Kaufman type (electron impact type) is applied to the surface thereof.
An electrode is supported by a support member 5 so as to face the ion gun 4 so that the ion gun 4 is incident at an incident angle of 5°, and a coating 6 of an electrically insulating heat-resistant synthetic resin or its precursor is laminated on the electrode side surface. The substrate 7 is supported by a support member 8 so that the particles of the dielectric 3 sputtered onto the surface of the coating 6 are incident at an incident angle of 10° or less. Note that the distance between the dielectric 3 and the coating 6 is set to about 100M.

Here, an example of manufacturing a liquid crystal alignment film using the apparatus is described in Example 1.
and 2.

Example 1 First, the dielectric material 3 of the target is 30C vertically and horizontally.
The IR×scm l'0□ plate is supported by the support member 5, and a polyimide precursor is coated on the electrode side surface by an appropriate method such as brush coating, dipping, spin-coding, spraying, or vacuum evaporation. An electrode substrate 7 measuring 30 cm x 30 cm in length and width, on which a coating 6 of a certain polyamic acid was laminated, was supported by a support member 8 .

Next, the inside of the processing chamber 1 is pumped through the vacuum evacuation system 2 to a
It was set to Torr.

Next, the dielectric material 3 was irradiated with ^r+ using the ion gun 4, and the particles of the sputtered dielectric material 3 were irradiated onto the surface of the film 6 for 10 seconds to form an island-like discontinuous film of ZrO2 on the surface. . That is, the boriamic acid coating 6 was exposed between the island-like coatings of z'02.

Finally, the electrode substrate 7 was taken out from the processing chamber 1 and placed in a heating chamber (not shown), and the polyamic acid laminated on the substrate 7 was heated to 200 to 40 G'C to polymerize into polyimide.

In this way, a large-area liquid crystal alignment film with no peeling, scratches, or discoloration and exhibiting extremely uniform alignment was obtained in a short time.

Example 2 The same process as in Example 1 was performed except that an electrode substrate 7 on which a polyimide film 6 was laminated in place of the polyamic acid film 6 was used, and the final heating polymerization process was not performed. A membrane was obtained.

Again, as in Example 1, a large-area liquid crystal alignment film with no peeling, scratches, or discoloration and exhibiting extremely uniform alignment was obtained in a short time.

In Examples 1 and 2, TiO2, Cr2O, Cu was used instead of ZrO2 as the dielectric material 3 of the target.
O1AJ! Even when 203.5i02 was used, a similarly excellent liquid crystal alignment film was obtained in a short time.

(Effects of the Invention) As described above, according to the present invention, since a dielectric island-shaped discontinuous film is formed on the surface of an electrically insulating heat-resistant synthetic resin film by oblique incidence sputtering, there is no possibility of peeling or scratches. In addition to being able to easily form a large-area liquid crystal alignment film that exhibits extremely uniform alignment, it also uses the dielectric itself as a target and sputters it by irradiating it with an ion beam. Since the pressure during processing is low and the spreading angle of sputtered particles is small, a liquid crystal alignment film exhibiting more uniform alignment can be obtained,
Furthermore, since it is not exposed to plasma, there is no risk of discoloration or damage to the alignment film (and since sputtering is performed by ion beam irradiation, the processing time is extremely short).

[Brief explanation of drawings]

The drawing is a partially cutaway front view of an example of an apparatus for carrying out the method for forming a liquid crystal alignment film of the present invention. 1... Processing chamber 2... Vacuum exhaust system 3... Dielectric material 4... Ion gun 5.8... Support member 6... Electrically insulating heat-resistant synthetic resin or its precursor Coating 7...electrode substrate

Claims (1)

[Claims] In a method for forming a liquid crystal alignment film, which comprises forming an island-like discontinuous film of a dielectric material on the surface of an electrically insulating heat-resistant synthetic resin film by oblique incidence sputtering, the dielectric material itself is used as a target, and the dielectric material itself is used as a target. 1. A method for forming a liquid crystal alignment film, which comprises sputtering by irradiating an ion beam onto a liquid crystal alignment film.