JPS61256322A - Production of liquid crystal display device - Google Patents

Abstract

PURPOSE:To orient uniformly a liquid crystal over a large area without generating defects at all by irradiating the light condensed or magnified by means of an optical system on a liquid crystal display cell from at least the front or rear of thereof during or after the injection of the liquid crystalline material thereby arranging the molecular orientation of the liquid crystalline material. CONSTITUTION:The 1st electrode 21, a composite diode 6 consisting of an NP<->N or NIN semiconductor laminate, the 2nd electrode 16 and further the 3rd electrode 23 consisting of a light transmittable conductive film in tight contact with the 2nd electrode are provided on a glass substrate 20 so as to cover the semiconductor laminate 6 and the org. resin in the side and periphery. Two sheets of the substrates 20, 20' are thereafter adhered and a spacer is inserted therebetween. The periphery is solidified with a resin to form the liquid crystal cell. The cell is put into a vacuum vessel and the liquid crystal is injected thereon. The light processed to a rectangular shape is irradiated on the liquid crystal cell from one side. DOBAMBC is used as the liquid crystal material and an Xe lamp having the output at which the liquid crystal material can be heated up to the isotropic liquid state is used as the light source and is processed to the rectangular shape. The orientation of the liquid crystal with the above-mentioned light is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a liquid crystal display device used in a display section of a microcomputer, word processor, television, or the like.

``Prior Art'' For solid-state display panels, a system in which each picture element is controlled independently is effective for large-area displays. A panel using such active elements has 640 elements in the horizontal direction (640 x 3 = 1920 elements in the case of full color) and 20 elements in the vertical direction.
There is a need for a display device with a large area matrix configuration of 44 format or larger with 0 elements or 526 elements.

Furthermore, with the increase in area size, liquid crystal display devices are being created that exhibit high-speed response using a liquid crystal material having a smectic phase.

"Problems to be Solved by the Invention" When producing these large-area liquid crystal display devices, especially liquid crystal display devices using a smectic phase, a problem is the technique for aligning the liquid crystal material.

As methods for this, the temperature gradient method, spacer edge method, rubbing method, etc. are currently used, but when the area is increased, only the rubbing method is possible.

However, since this method physically "scratches" the surface of the alignment film, it poses major problems such as uniform alignment throughout the large-area cell and memory effects.

1. Means for Solving Problems 1 The present invention is a method for producing a large-area liquid crystal display cell for solving these problems.

That is, after forming electrodes, electrode wiring, active elements, etc. necessary for configuring a circuit on a substrate, after bonding the substrates together to form a liquid crystal cell, a liquid crystal substance is injected into a rectangular or elliptical shape during or after injection. The feature is that the liquid crystal material sealed in the cell is aligned by moving the processed light relative to the liquid crystal cell. "Operation" That is, by moving light processed into a rectangular or elliptical shape relative to the liquid crystal cell, a temperature gradient is artificially created to orient the liquid crystal.

The present invention will be explained below with reference to Examples.

"Example" FIG. 2 shows a circuit diagram using the solid state display device of this example.

In the drawing, the pixel is the electrode (22) of the non-linear element (6).
(second electrode), one electrode (23) of the liquid crystal (7) (
a third electrode). The non-linear elements are connected by first electrodes (21) to address lines (8) and (9) of the X wiring which provide clock signals. On the other hand, the liquid crystal (7
) the fourth electrode (24) of the X wiring data line (10),
(II). The X wiring is connected to another light-transmitting insulating substrate, typically a glass substrate ((20
'))) are provided correspondingly to each side. And this fourth electrode (24) is R (red) (Yl), G (green) (yz
), B (blue) (omitted in the ys drawing) filter (25)
, (25'), and is in full color.

This X wiring is connected to the same insulating substrate, typically a glass substrate (fifth
(20) in Figures (B), (C), and (D))
It is located in J2. As a result, crosstalk (3
3) is difficult to occur, so the resistance of this part should be set to 109 Ω or more.
Preferably, it became possible to set the resistance to 1010Ω or more.

Such picture elements are arranged in a matrix, 2×2 in the drawing.
showed that. However, the present invention does not use a small matrix, but a scaled and amplified display word, for example (100 pixels).
Effective for large matrix panels such as 100x100, 1920x200 or 512).

Examples of the manufacturing process and characteristics of a nonlinear element that is part of a pixel using such a composite diode are shown in Figures 3 and 4.
Shown in the figure.

The manufacturing process shown in FIG. 3 is (30
) is particularly suitable for expanding the manufacturing area.

Figure 3 (8), (B), (C), (D-2)
corresponds to the longitudinal cross-sectional view of FIG. 5 c-c'. Figure 3 (
D-1) corresponds to the vertical cross-sectional view of ^-A'' in FIG. 5, and shows the element structure.

In FIG. 3 (8), Konink 7059 glass (20) was used as the light-transmitting insulating substrate. On this top surface, a conductive film of aluminum (14) and a chromium film (15) on top of it are deposited by sputtering or electron beam evaporation.
Formed to a thickness of ˜0.5 μm and 500-1500 μm, respectively. Chromium (500 to 1500) may be formed under the aluminum to further promote adhesion with glass.

After this, N is applied to the entire surface using plasma gas phase reaction method.
A composite diode made of a non-single crystal semiconductor having an IN (including NP-N, NIPIN, and NIP-do-IN) structure was formed. That is, 13.56MH2 of N-type semiconductor with silane
By performing high frequency glow discharge of 200 to 300
A non-single-crystal semiconductor is formed on the surface of the substrate held at 2°C.

Its electrical conductivity is 10-7 to 10-' (00m).
” with a thickness of 500 to 2,500 people. Next, 10
The vacuum was sufficiently drawn to -6 to 1 O-7 torr. Silane (SimHz□.2 e.g. S+H4 with m=1) and D
Using MS (St (CHa) 3), B and l (6) are added as necessary to form a ■-type non-single crystal semiconductor.
It was formed to a thickness of 0 to 0.5 μm. For example, for a thickness of 0.2μ, DMS/(DMS+SiH,) −1/80. B
2116/5in4. = 7PPM as P-type 5i
XC+-x was formed.

Further, the chamber was sufficiently evacuated to 10-6 to 10-'torr.

Layer an N-type semiconductor on top of it to a thickness of 50 to 500 to form an NP-N junction of 5i-3jxC+-'x (0<X4)
-st heterojunction was formed.

Thereafter, chromium (16) for light shielding was laminated as a second electrode on the upper surface by electron beam evaporation or sputtering.

Furthermore, as shown in FIGS. 3(A) and 3(B), anisotropic plasma etching was performed using the first photomask (17) so that the peripheral part (26) was vertical, and the laminated body (18)
) was configured. Next, heat the entire surface to 200°C, for example.
The semiconductor (6) was subjected to thermal oxidation, and silicon oxide was produced by solid phase-vapor phase oxidation. Next, a photosensitive polyimide resin (29) was formed on the entire surface of these by a coating method to a thickness of about 2 μm. Thus, the F-plane (
16) and the top surface (39) of the polyimide resin (29) become approximately the same plane after curing (the insulator surface and the laminate surface are smoothly continuous), excluding the convex portion of the laminate (18). I made it happen. For example, 40 to 5 depending on development and curing.
When decreasing by 0x, the thickness of the laminate is approximately 1μ, so approximately 2
The thickness was μ. Next, ultraviolet light (40) was exposed from the back side of the glass substrate (20) using a known mask aligner without using a mask. For example, with Cobilt's aligner, the exposure time was about 2 minutes. Its strength is 300-40
For ultraviolet light (10 mW/cm2) with a wavelength of 0 nm, 15 to 30 seconds is sufficient.

Then, as shown in FIG. 3(C), the convex region above the laminate having the side surface of (26), which is in the shadow, is not exposed to light.
Only the area around that side is exposed to light. After further development, the non-photosensitive convex portions were dissolved away using a rinsing solution. Thus the third
Figure (C) was obtained.

Next, do all of this at 180℃ for 30 minutes + 300℃ for 30 minutes +
Cure was performed by heating at 400° C. for 30 minutes in nitrogen. In addition to exposing the second electrode of the non-linear element, which is the upper surface of the laminate, without using a photomask, this upper surface and the surface of the polyimide resin insulator in the periphery are configured to be approximately on the same plane. became possible.

Next, CTF was formed on the entire upper surface of FIG. 3(C) using ITO or tin oxide to a thickness of 0.1 to 0.5 .mu.m. Furthermore, this CTF was selectively etched using a second photomask (3). In addition, this CTF (23) constitutes the electrode of the pixel tube 3 of the liquid crystal (Fig. 2 (23)), and using this CTF as a mask, unnecessary semiconductors between the pixels (31) are removed to (D-1). Removed as shown. In this way, Figures 3 (D-1) and (D-2) were obtained.

Furthermore, after this, for the (31) side of this semiconductor, (
It is effective to fill a portion of the polyimide resin for forming an alignment film on the insulator CTF similar to 29).

That is, in FIG. 3, a first electrode (21) on a glass substrate (20), a composite diode (6) made of an NP-N or NIN semiconductor laminate, and a second electrode (16)
Further, a third electrode (23) made of a light-transmitting conductive film was provided closely to the second electrode so as to cover the semiconductor laminate (6) and the organic resin around the sides.

Thereafter, the two substrates (20) and (20') were pasted together, a spacer of approximately 10 μm was inserted between them, and the periphery was solidified with resin to form a liquid crystal cell. After that, this cell was placed in a vacuum chamber and liquid crystal was injected into it. Thereafter, the liquid crystal cell was irradiated with light processed into a rectangular shape (a Xe lamp was used in this example) from one side. A schematic diagram of this is shown in FIG. 1(A).

In this example, DOBAMBG is used as the liquid crystal substance, and as a light source, an IK-Xe lamp with an output capable of heating the liquid crystal substance to an isotropic liquid state is used.
It was processed into a rectangular shape of m x 200 mm. With respect to this light, the liquid crystal could be aligned in the liquid crystal cell at a speed of 5 mm/min in about 60 minutes. Thereafter, polarizing plates were adhered to both sides of the liquid crystal cell to form a liquid crystal display cell.

Note that it goes without saying that the present invention is not limited only to this example.

In particular, the type and output of the light source can be varied depending on the nature of the liquid crystal material and the type of substrate.

"Effects" □The present invention has made it possible to perform alignment processing that was previously considered to be an effective means of alignment treatment, but was considered unsuitable for industrial applications such as large-area, mass-production, etc., and is suitable for alignment treatment of large-area liquid crystal display cells. It was particularly effective.

In addition, compared to the rubbing method currently used industrially, it does not generate any dust or other debris in the areas where the liquid crystal material comes into direct contact, so the liquid crystal is aligned uniformly over a large area and no defects occur. Uniform alignment of liquid crystals was obtained over a large area.

Furthermore, the present invention makes it possible to utilize the memory effect of the liquid crystal material, which is said to be impossible with the rubbing method, making it possible to create a liquid crystal display cell with a large area and excellent high-speed response.

[Brief explanation of drawings]

FIG. 1 shows a schematic diagram of the method of the invention. FIG. 2 shows a circuit diagram of the liquid crystal display panel of the present invention. FIG. 3 is a longitudinal sectional view showing the manufacturing process of a liquid crystal cell. . FIG. 4 shows the operating characteristics of the nonlinear element of the composite diode used in the present invention. FIG. 5 shows a plan view and a longitudinal sectional view of the display panel of the present invention.

Claims (1)

[Claims] 1. In a liquid crystal display cell in which a liquid crystal substance is sealed in spaces having regular intervals formed on a flat substrate, light is focused or expanded through an optical system during or after injection of the liquid crystal substance. A method for manufacturing a liquid crystal display device, characterized in that the light is irradiated from at least one of the front or back sides of the liquid crystal display cell to adjust the molecular orientation of the liquid crystal substance. 2. The method for manufacturing a liquid crystal display cell according to claim 1, wherein the shape of the condensed or expanded light is rectangular or elliptical.