JPH0269717A - Manufacture of liquid crystal display panel - Google Patents

Abstract

PURPOSE:To decrease the man-hours of a manufacture process and to reduce the cost by supporting the surface of an insulating film at 80-90 deg. to a horizontal surface, and performing vapor deposition so that the thickness of a vapor- deposited of silicone monoxide rising vertically from a vapor-deposition source is at least 800Angstrom . CONSTITUTION:A transparent electrode 2 is formed on the transparent substrate 1 of the liquid crystal display panel and when the transparent electrode 2 is coated with the insulating film 12 by an oblique vapor-depositing means, silicon monoxide is vapor-deposited slantingly at a 80-90 deg. vapor-deposition angle until the vapor-deposited film thickness reaches at least 800Angstrom while a transparent substrate 1 is held in a vapor-depositing device so that the vapor-depositing direction (arrow P) of silicon monoxide meets an orienting line direction. Consequently, while the high insulating film with superior step coating property is formed of a soft insulating film like cotton, no rubbing processing is performed, so an insulating film and orienting film 12 which has a required orienting function is obtained, the process is shortened, and the cost is reduced.

Description

[Detailed Description of the Invention] (Summary) This invention relates to a method of manufacturing a liquid crystal display panel, and particularly to a method of insulating a transparent electrode formed on a glass substrate and simultaneously forming an alignment film, which reduces the number of man-hours in the manufacturing process. The purpose of the present invention is to provide a method for manufacturing a liquid crystal display panel that is possible and cost-effective, and in which a transparent electrode is formed on a transparent substrate of a liquid crystal display panel, and an insulating film is coated on the transparent electrode by an oblique evaporation method. After holding the transparent substrate so that the direction of the alignment line to be formed for the electrode coincides with the vertical rising direction in the vapor deposition apparatus, the surface of the insulating film is set at an angle of 80° with respect to the horizontal plane.
Supported at an angle of ~90 degrees, the thickness of the deposited silicon monoxide (SiO) film rising vertically from the deposition source is at least 8
By performing vapor deposition processing so that the thickness of the film becomes 0.00, an insulating film and an alignment film are formed.

[Industrial application field]

The present invention relates to a method of manufacturing a liquid crystal display panel, and more particularly to a method of manufacturing a liquid crystal display panel, in which transparent electrodes formed on a glass substrate are coated with insulation and an alignment film is simultaneously formed.

(Prior Art) FIG. 6 shows a schematic cross-sectional view of a conventional liquid crystal display panel. In the figure, 1 and 10 are transparent substrates facing each other, and transparent glass or the like is used. 2 and 9 are transparent substrates +ff1. Transparent electrodes are formed facing each other on the transparent electrodes 10, each made of indium/tin oxide (ITO film), etc., in the shape of a door.3 and 8 are insulating films for preventing short circuits between the transparent electrodes. The insulating films 3 and 8 are provided so as to cover at least one side of the insulating films 3 and 8. This figure shows an example in which they are provided on both sides.
is usually an insulating film based on a silicon oxide (SiO7) film, and is doped with some impurities (for example, boron, etc.) in order to improve step coverage (coverage of the stepped portion of ff!) with the ITO film. is mixed in, and is formed by sputtering.

Reference numerals 4 and 7 denote alignment films facing each other, which are usually coated with polyimide and whose surfaces are rubbed in a desired alignment direction. Further, film forming methods using plasma polymerization or vapor deposition are also known. 5 indicates the sealed liquid crystal, and 6 indicates a sealant for sealing the liquid crystal.

11 is an enlarged display of liquid crystal molecules constituting the liquid crystal 5. FIG. When a predetermined voltage is applied between the transparent electrodes 2 and 9, the long axis direction of the liquid crystal molecules 11 is aligned with the alignment direction labiled by the alignment films 4 and 7, and is aligned with respect to the alignment film surface. Align to an angle φ in a certain direction. This angle φ is referred to as the tilt orientation angle. Since the tilt alignment angle is accompanied by deviation in value depending on the liquid crystal molecules 11, it is expressed as an average value, and is hereinafter referred to as an average pretilt angle. This average pretilt angle has the property of contributing to the orientation direction.

What kind of liquid crystal molecular alignment is formed is determined by the alignment effect of the interface state between the liquid crystal and the substrate. Therefore, once the liquid crystal to be used is determined, its molecular arrangement is determined by what kind of orientation treatment is applied to the substrate surface.

[Problem to be solved by the invention]

Conventionally, a manufacturing process is required in which the insulating film 3 is formed by sputtering, then the alignment film 4 is applied, and then rubbing is performed, which has the disadvantage that the manufacturing time is too long.

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide a method for manufacturing a liquid crystal display panel that can reduce the number of manufacturing steps and is oriented toward low cost.

[Means to solve the problem]

FIG. 1 shows an explanatory diagram of the manufacturing method of the present invention. When forming a transparent electrode 2 on a transparent substrate 1 of a liquid crystal display panel and coating the transparent electrode 2 with an insulating film 12 by oblique vapor deposition,
After holding the transparent substrate 1 so that the direction of the alignment line to be formed on the transparent electrode 2 coincides with the vertical rising direction in the vapor deposition apparatus, the surface of the insulating film I2 is set at an angle of 80° with respect to the horizontal plane.
The insulating film/alignment film 12 is formed by supporting it at an angle of ~90 degrees and performing a vapor deposition process so that the thickness of silicon monoxide (SiO) vertically rising from the vapor deposition source 14 is at least 800 degrees. Configure.

[For production]

8 while holding the transparent substrate 1 in the vapor deposition apparatus so that the direction of vapor deposition of silicon monoxide (direction of arrow P) matches the direction of the alignment line.
When silicon monoxide is obliquely deposited with a deposition angle (the angle between the horizontal plane and the surface to be deposited) in the range of 0 to 90 degrees, and the thickness of the deposited film is at least 800 degrees, a transparent substrate is formed. There is a large difference in the distribution of the deposited film thickness between the upper and lower regions of l, and the ratio may be about 3 times as much, but when the deposited film thickness exceeds 800 Å, the average pretilt angle φ that contributes to liquid crystal alignment becomes larger than the deposited film thickness. It tends to be saturated without much regard to the temperature, and has the functions of both an insulating film and a uniformly oriented film.

In other words, a highly insulating film with excellent step coverage can be obtained using a cotton-like soft insulating film, and at the same time, an insulating film/alignment film 12 having the required alignment function can be obtained without labiling processing. Effective for shortening.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that, in order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

FIG. 1 shows an explanatory view of the manufacturing method of the present invention, in which only the main points of the posture of the member to be deposited in the vapor deposition apparatus and the thin deposition direction are shown, and the description of the electrodes and other device configurations is omitted. In the figure, 12 is an insulating film/alignment film, and 13 is a substrate mounting surface in the vapor deposition apparatus, which coincides with the horizontal surface. θ is the surface to be evaporated (
14 is a deposition source containing silicon monoxide, and the vaporized silicon monoxide particles rise vertically as shown in the deposition direction P, and This figure shows oblique deposition at a deposition angle θ with respect to the surface.

The orientation line direction of the transparent substrate 1 to be formed with respect to the transparent electrode 2 is set on the substrate mounting surface 13 of a substrate mounting table provided in the vapor deposition apparatus.
After the deposition angle θ is held perpendicular to
Support the surface to be deposited at an angle of 80 to 90 degrees,
- The thickness of the obliquely deposited silicon oxide (SiO) is at least 80 mm.
Vapor deposition processing will be performed so that there will be 0 people.

When oblique evaporation is performed in this manner, the thickness of the evaporated film will naturally be thicker in the region near the bottom of the transparent substrate 1 near the evaporation source 14, and thinner in the region near the top. The film thickness ratio may be about 3 times as much.

FIG. 2 shows a characteristic curve of average pretilt angle/SiO film thickness of the present invention. As can be seen from this characteristic, the thickness of the deposited film is 80 mm.
When the temperature exceeds 0 Å, the average pretilt angle φ that contributes to liquid crystal alignment tends to be saturated around 35 to 40 degrees, regardless of the deposited film thickness.Using this property, the insulating function of the SiQ film itself and the uniform alignment film can be improved. This realizes an insulating film and alignment film that has both functions.

FIG. 3 is a diagram showing differences in transmission intensity/incident angle characteristics of a liquid crystal cell depending on alignment film thickness. The transmission intensity in this characteristic diagram refers to the transmission intensity of red light with a wavelength of 637 nm.
The transmittance when transmitting through a liquid crystal cell of 11.2- is normalized, and the case of zero transmission loss is set to 1.0. The characteristic curves ■ to ■ shown in the figure each have a uniform alignment film thickness of 30
Characteristics of liquid crystal cells for 4 people, 977 people, 2080 people, and 3450 people are shown. When the incident angle is 0 degrees when the incident angle is normal to the panel surface of the liquid crystal cell, when the incident angle is 60 degrees to the left and right, a bimodal transmission intensity characteristic as shown in the figure is obtained, and moreover, when the uniform alignment film thickness is 800 Å or more, It can be seen that the difference in transmission intensity characteristics tends to disappear.

That is, the uniform alignment film thickness covering the transparent electrode is 800 Å.
It can be seen that even the above thickness (usually sheet resistance of 20 Ω/cm 2 or less) does not adversely affect the transmittance.

The fourth data shows the orientation regulating force shown from the film thickness dependence of SiO, and the vertical axis shows the transmission intensity H? in Fig. 3. The value is expressed in % (i8 maximum value) - (minimum value), and the horizontal axis shows the uniform film thickness of SiO per person. According to this data, it has been shown that when the SiO film thickness is 800 Å or more, the transmission intensity becomes stable and it can be used as an alignment film.

- The silicon oxide SiO film is originally a soft film like cotton, so it has good step coverage and overcoats the steps (approximately 2,800) of the transparent electrode.

FIG. 5 shows the average pretilt angle/deposition angle characteristics.

This characteristic curve was actually measured for a liquid crystal panel at a substrate temperature of 200°C and a deposition time of 20 minutes.The horizontal axis represents the deposition angle, and the vertical axis represents the average pretilt angle. The data for the measurement points are marked with △, and the data of the measurement points near the center and the top are plotted with ◯.

This data reveals that it cannot be applied as an alignment film for liquid crystal displays unless the deposition angle is 80 degrees or more.

[Effects of the Invention] As is clear from the above description, according to the present invention, a film having both an insulating film and an alignment film can be manufactured in one step, and for example, a film having a length of 400 dots and a width of 640 dots can be manufactured in one step. 11
This method has a significant industrial effect in that inch-sized panels can be formed with high yield and contributes to lower costs for panel manufacturing.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the manufacturing method of the present invention, Figure 2 is the average pretilt angle/SiO film thickness characteristic curve of the present invention, and Figure 3 is the transmission intensity/incident angle characteristic of the liquid crystal cell depending on the alignment film thickness. Figure 4 shows the difference between (average of maximum values) - (
FIG. 5 is a diagram showing the dependence of SiO film thickness (average of minimum values), FIG. 5 is an average pretilt angle/accumulation angle characteristic, and FIG. 6 is a diagram showing a schematic cross-sectional view of a conventional liquid crystal display panel. In FIG. 1, 1 is a transparent substrate, 2 is a transparent electrode, 12 is an insulating film/alignment film, and 14 is a vapor deposition source. ←SaigentoΔto）上心（〈）

Claims (1)

[Claims] When forming a transparent electrode (2) on a transparent substrate (1) of a liquid crystal display panel and coating the transparent electrode (2) with an insulating film (12) by oblique vapor deposition means, the transparent electrode After holding the transparent substrate (2) so that the direction of the alignment line to be formed with respect to (2) coincides with the vertical rising direction in the vapor deposition apparatus, the surface of the insulating film (12) is 80 degrees with respect to the horizontal plane. The insulating film/alignment film ( 12) A method for manufacturing a liquid crystal display panel.