WO1993001517A1

WO1993001517A1 - Liquid crystal display and method of manufacturing said display

Info

Publication number: WO1993001517A1
Application number: PCT/JP1992/000842
Authority: WO
Inventors: Takatoshi Takemoto; Kazunari Kawashima
Original assignee: Kabushiki Kaisha Ace Denken
Priority date: 1991-07-03
Filing date: 1992-07-03
Publication date: 1993-01-21
Also published as: JPH0527223A; AU2231892A

Abstract

A liquid crystal display and a method of manufacturing said display for improving display accuracy of liquid crystal layers by making the thichnesses of said layers uniform, reducing said thicknesses for better response capability, and setting said layers in more exact arrangement. A transparent electrically conductive film (16a) is formed on one surface of a transparent insulating substrate (21a). Said substrate (21a) is coated for insulation with oxidized film (18a) for spacer. Masks are formed on specified parts of said oxidized film (18a) for spacer. Non-masked parts of said oxidized film (18a) are etched to form spacers (18). Then, the masks (22) are removed. Liquid cyrstal layers (19) are put into spaces in which the spacers (18) are present. The other transparent insulating substrate (21b) is arranged on the spacers (18) and liquid crystal layers (19) with a transparent electrically conductive film (16b) directed inside.

Description

TECHNICAL FIELD The present invention relates to a liquid crystal display device having a liquid crystal layer provided between two transparent insulating substrates and a method for manufacturing the liquid crystal display device. BACKGROUND ART As a conventional liquid crystal display device, for example, there is one as shown in FIG.

That is, the conventional liquid crystal display device 1 is manufactured as follows. First, an alkali elution preventing barrier film 3 is applied to both surfaces of each of two glass substrates 2. Also, a color filter 4 and the like are formed on the alkali elution preventing barrier film 3 on one substrate. On top of this, a transparent conductive film 5 is formed in a vacuum thin film process by sputtering so that the pixels can be turned on and off, and the upper surface is covered with an alignment film 6 to form two substrates. .

On one of the substrates, a spacer 8 made of bead-like plastic or cylindrical glass fiber, etc. of several μπι to several tens yam is randomly arranged so that the liquid crystal layer 7 can maintain uniform dimensions. . The other substrate is pasted thereon so that the alignment film 6 faces each other, and the liquid crystal is injected into the gap maintained by the spacer 8. in this way The polarizing film 9 is formed on both sides of one liquid crystal cell thus formed, and the liquid crystal display device 1 is configured.

However, such conventional techniques have the following three problems.

That is, 1. Since the size of the spacer 8 varies, the thickness of the liquid crystal layer 7 varies according to the size of the spacer 8, and there is a limit in making the thickness of the liquid crystal layer 7 uniform. . 2. Since the spacer 8 has a minimum diameter of 10 to 15 mm, there is a limit in making the liquid crystal layer 7 thinner and improving the responsiveness. 3. Since the spacers 8 are randomly placed and arranged on the alignment film 6, the arrangement of the liquid crystal layers 7 in the gaps maintained by the spacers 8 is also random, and the liquid crystal layers 7 There is a limit in improving the display accuracy of. DISCLOSURE OF THE INVENTION The present invention has been made in view of such problems of the conventional technology, and aims to make the thickness of the liquid crystal layer uniform, and to make the liquid crystal layer thinner to improve the responsiveness. Another object of the present invention is to provide a liquid crystal display device and a method for manufacturing the liquid crystal display device, which can improve the display accuracy of the liquid crystal layer by accurately arranging the liquid crystal layer and improving the display accuracy of the liquid crystal layer. ing.

In order to achieve the above object, according to the present invention, two facing transparent insulating substrates, a transparent conductive film provided on each of the opposing surfaces of the transparent insulating substrates, A spacer for forming a space between the two transparent conductive films, A liquid crystal display device, comprising: a liquid crystal layer filled in a space; and the spacer is formed on at least one of the transparent conductive films. .

Further, according to the present invention, a transparent conductive film is formed on each of the opposing surfaces of the two transparent insulating substrates used to face each other, and the two transparent insulating substrates are faced via a spacer, In a method of manufacturing a liquid crystal display device including a liquid crystal layer present in a space formed by a spacer, a method of forming a transparent conductive film on one surface of one of the two transparent insulating substrates is provided. Step 1, a second step of forming a transparent conductive film on one surface side of the other of the two transparent insulating substrates, and a step of forming the transparent conductive film in the first step. A third step of insulatingly covering the substrate with a spacer oxide film on the transparent conductive film; a fourth step of forming a mask on a predetermined portion of the spacer oxide film; The unmasked portion of the oxide film for the sensor is etched. A fifth step of removing and forming an oxide film spacer; a sixth step of removing the mask; and a seventh step of injecting a liquid crystal layer into a space where the oxide film spacer does not exist. And an eighth step of disposing the transparent insulating substrate, on which the transparent conductive film is formed in the seventh step, on the oxide film spacer and the liquid crystal layer with the transparent conductive film inside. A method for manufacturing a liquid crystal display device, comprising:

Further, according to the present invention, a transparent conductive film is formed on each of the opposing surfaces of the two transparent insulating substrates used to face each other, and the two transparent insulating substrates are opposed to each other via a spacer. Let it be formed in a space A method of manufacturing a liquid crystal display device comprising a liquid crystal layer in a space defined by a first step of forming a transparent conductive film on one of the two transparent insulating substrates on one surface side thereof. A second step of forming a transparent conductive film on one surface side of the other of the two transparent insulating substrates; and a mask on a predetermined portion of the transparent conductive film formed in the first step. A third step of forming an oxide film spacer on a non-mask portion of the transparent conductive film; a fifth step of removing the mask; and a third step of removing the mask. A sixth step of injecting a liquid crystal layer into a space in which no transparent film is present, and the transparent insulating substrate on which the transparent conductive film has been formed in the second step, and And a seventh step of disposing the liquid crystal layer on the liquid crystal layer. A method for manufacturing a liquid crystal display device is provided.

The spacer is sandwiched between a transparent conductive film between two transparent insulating substrates to form a space for a liquid crystal layer. Since the spacer is formed of an oxide film, the thickness of the film can be easily adjusted. The thickness of the liquid crystal layer can be made uniform by adjusting the thickness of the spacer uniformly. Further, since the spacer is formed of an oxide film, a thin film having a thickness of, for example, about 6 μπι can be manufactured. As a result, the liquid crystal layer can be made thinner, and the response can be improved.

Further, since the spacer is formed of an oxide film, it can be arranged at a predetermined position with high accuracy by using a mask. As a result, the liquid crystal layer in the gap maintained by the spacer is positioned at a predetermined position. The display accuracy of the liquid crystal layer can be improved.

When the transparent insulating substrate is made of a flexible transparent plastic, a liquid crystal display device that is durable against bending can be obtained.

In a liquid crystal display device, a spacer is formed by forming a mask on a predetermined portion of a spacer oxide film and removing a non-mask portion by etching. Can be arranged at a predetermined position with high accuracy. Therefore, the liquid crystal layer can be arranged at a predetermined position, and the display accuracy of the liquid crystal layer can be improved.

In the liquid crystal display device, a spacer may be formed by forming a mask on a predetermined portion of the transparent conductive film and growing an oxide film on an unmasked portion of the transparent conductive film. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a perspective view illustrating a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 5 shows a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention. FIG.

FIG. 6 is a plan view showing a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 7 is a perspective view showing a transparent insulating substrate used in the liquid crystal display device according to the second embodiment of the present invention.

FIG. 8 is a sectional view showing a conventional liquid crystal display device. BEST MODE FOR CARRYING OUT THE INVENTION Various embodiments of the present invention will be described below with reference to the drawings.

1 to 6 show a first embodiment of the present invention. This embodiment is an example of a liquid crystal display device having a thin film transistor (TFT) for turning on and off a pixel.

As shown in FIG. 1, the liquid crystal display device 10 of the present embodiment has a liquid crystal cell and a polarizing plate. The liquid crystal cell consists of two glass substrates 11a and 11b, an alkaline elution preventing barrier film 12, a black matrix 13 and a color filter 14 and a color filter. The paper coat 15 of the reflector 14, the transparent conductive films 16 a and 16 b, the alignment film 17, the spacer 18, the liquid crystal layer 19, and the polarizing film 20 And a source / drain metal film 31, an omic contact film 32, an etching stopper 33, a carrier film 34, and a dielectric film 35 constituting the thin film transistor 30. And a gate electrode film 36.

The liquid crystal display device 10 is manufactured by the following steps.

Al force consisting of S i 0 _{2 on} both sides of one glass substrate 1 1 a The re-elution prevention barrier film 12 is applied and sintered to form the transparent insulating substrate 21a. Cr is evaporated on one surface of the transparent insulating substrate 21a, and the Cr film is left by photolithography to leave necessary parts, thereby achieving a black matrix. Form 1 3. Next, a color filter 14 is printed from above. Further, an overcoat 15 is formed on the color filter 14 using a synthetic resin such as an acrylic resin or a urethane resin.

A transparent conductive film 16a made of IT 基板 (indium tin oxide) is formed on the overcoat 15 of the transparent insulating substrate 21a by a vacuum thin film process by sputtering. As shown in FIG. 6, the transparent conductive film 16a is formed as a pattern in which a plurality of transparent conductive films are arranged in parallel at equal intervals to form an electrode. Each transparent electrode 16a has a terminal 16c at its end.

On the substrate, a spacer oxide film 18a for providing the spacer 18 is deposited to a thickness of 6 inches. As the spacer oxide film 18a, a silicon oxide film is used. This silicon oxide film can be formed by, for example, a plasma CVD method, a sputtering method, or the like. Here, the film is formed by a plasma CVD method. That is, the S i H ₄ and N_〇 ₂ using a gas that is diluted with A r, in 1 0 0 ° (~ 2 0 0 substrate temperature ° C, forming a film of the S i 〇 _2.

As shown in FIG. 4, a negative photoresist 22 is formed on the spacer oxide film 18a. As shown in Figures 2, 5, and 6, a photomask is placed in place over the negative photoresist 22. Form 23. As shown in the plan view of FIG. 6, the light-transmitting region of the photomask 23 is a center position surrounded by each electrode of the liquid crystal display device 10 to be manufactured. The translucent regions of the photomask 23 are regularly arranged, for example, in a matrix.

The negative photo resist 22 is irradiated with light in a state where the photo mask 23 is provided. After the exposure, development is performed to remove the negative photoresist 22 covered with the photomask 23. The photo resist 22 is left as a mask on the exposed portion.

Next, for example, when etching is performed by a dry etching method using a gas such as CF ₄ or the like, as shown in FIG. 3, for a spacer which is not covered by the negative photoresist 22. The unmasked portion of the oxide film 18a is removed, and the remaining spacer oxide film 18a forms a spacer 18. The spacers 18 are formed at regular intervals according to the position of the photomask 23 and have a constant size. The substrate is washed to remove the photoresist 22 as a mask. An alignment film 17 is formed in a portion where the spacer 18 does not exist, and a liquid crystal layer 19 is injected thereon.

On the other hand, for 1 lb of another glass substrate, as shown in Fig. 1, an alkali elution prevention barrier film 12 is applied to both sides and sintered, and the other transparent insulating substrate 2 1 Prepare b. A gate electrode film 36 is formed on a part of one surface of the transparent insulating substrate 21b. A dielectric film 35 is formed on the gate electrode film 36 and on the alkali elution preventing barrier film 12 by using a plasma CVD device.

On the dielectric film 35 of the transparent insulating substrate 2 la, a transparent The light conductive film 16b is formed by sputtering. As shown in FIG. 6, the transparent conductive film 16b is formed as a pattern in which a plurality of transparent conductive films are arranged in parallel at equal intervals to form an electrode. Each transparent conductive film 16 b has a terminal 16 c at an end. These electrodes are arranged so as to be orthogonal to the electrodes of the transparent insulating substrate 21a.

A carrier film 34 is formed above the gate electrode film 36 via a dielectric film 35, and an etching stopper 33 is formed on a part of the carrier film 34. An ohmic 'contact film 32 is formed on the carrier film 34 so as to cover the etching stopper 33. A source / drain metal film 31 is formed on the ohmic contact film 32, and the orientation film 1 covers the source / drain metal film 31 and the transparent conductive film 16b. Form 7.

Source 'drain metal film 31, ohmic contact film 32, etching stopper 33, carrier film 34, dielectric film 35, and gate electrode film 36 constitutes the thin-film transistor 30.

The other prepared transparent insulating substrate 21b is placed on the spacer 18 and the liquid crystal layer 19 of the transparent insulating substrate 21a, with the transparent conductive films 16a and 16b inside. And stick them together. A polarizing film 20 is formed on both sides of the manufactured liquid crystal cell to constitute a liquid crystal display device 10.

In the liquid crystal display device 10 thus manufactured, the two transparent insulating substrates 21a and 21b are arranged with the transparent conductive films 16a and 16b facing each other. A gap between each transparent conductive film 16a and 16b A space between them. In the space between the transparent conductive films 16a and 16b, a liquid crystal layer 19 is interposed in a region where the spacer 18 does not exist.

In FIG. 1, a spacer 18 is sandwiched between transparent conductive films 16 a and 16 b between two transparent insulating substrates 21 a and 21 b, and a liquid crystal layer 19 is present. Form a space for The spacer 18 is formed of an oxide film. Therefore, it is easy to adjust the thickness of the film. The thickness of the liquid crystal layer 19 can be made uniform by adjusting the thickness of the spacer 18 uniformly.

Further, since the spacer 18 is formed by a film forming technique, it can be manufactured as thin as about 6 μπι. As a result, the liquid crystal layer 19 can be made thinner, and the response can be improved.

Further, in the liquid crystal display device 10, a mask of the photo resist 22 is formed on a predetermined portion of the oxide film 18a for a spacer, and an unmasked portion is removed by etching. Since the spacer 18 is formed, the spacer 18 can be arranged at a predetermined position with high accuracy. Therefore, the liquid crystal layer 19 can be arranged at a predetermined position in the space held by the spacer 18, and the accuracy of the shape of the pixels of the liquid crystal layer 19 can be improved. As a result, the manufactured liquid crystal display device 10 can display with high accuracy. C

Next, a second embodiment of the present invention will be described.

In this embodiment, another configuration of the liquid crystal display device 10 is shown. You.

In the first embodiment, as a transparent plate material for a substrate, a transparent insulating substrate 21 a, which is formed by applying an alkali elution preventing barrier film 12 on both sides of a glass substrate 11 a, 11 b, is used. 2 lb is used. On the other hand, in the present embodiment, the transparent insulating substrate 41 is made of a flexible transparent plastic material. The transparent plastic is, for example, a polymer material such as polyester and polyimide.

Products such as IC cards, card-type calculators, and pagers may be handled fairly violently. In the liquid crystal display devices used in these, the glass substrate may be damaged by the application of bending force.

On the other hand, in the method of the above embodiment, the spacer can be fixedly arranged by the film forming technology, so that the transparent insulating substrate

Even if 1 is formed of a flexible, thin, and relatively soft transparent plastic, the spacer does not move. For this reason, a stable liquid crystal layer can be formed. Therefore, when the transparent insulating substrate 41 is made of a flexible transparent plastic, a liquid crystal display device which is thinner and more durable against bending can be obtained.

Further, by forming the transparent insulating substrate from a flexible, thin, transparent plastic, the surface of the liquid crystal display device can be bent to a flat surface, a concave surface, or a convex surface. For example, using a transparent insulating substrate 41 having a curved surface as shown in FIG. -1-

A liquid crystal display device suitable for realizing a screen can be manufactured.

Next, a third embodiment of the present invention will be described.

This embodiment shows another method of manufacturing a liquid crystal display device.

As shown in FIGS. 1 to 3, a transparent insulating substrate similar to that of the first embodiment is prepared, and a transparent conductive film is formed on one surface of the transparent insulating substrate. The photo resist mask is formed by printing.

After irradiating the negative photo resist, develop. The photo resist is left as a mask at the exposed predetermined portion. An oxide film is grown on an unmasked portion of the transparent conductive film that is not covered by the photoresist to form a spacer. After the spacer is formed, the photo resist mask is removed. An alignment film is formed in a region where no spacer exists, and a liquid crystal layer is injected from above.

Next, another transparent insulating substrate similar to that of the first embodiment is placed on the spacer and the liquid crystal layer with the transparent conductive film inside, and bonded together with the transparent conductive film inside. A polarizing film is formed on both sides of the manufactured liquid crystal cell to constitute a liquid crystal display device.

As described above, in the liquid crystal display device, the spacer 18 may be formed by forming a mask on a predetermined portion of the transparent conductive film and growing an oxide film on a non-mask portion of the transparent conductive film.

In the above embodiment, as the spacer, but shows an example of using the S i 0 _2, the present invention is not limited thereto. A film of another insulating material may be used. For example, a silicon nitride film can be used. Further, in the above embodiment, the thickness of the oxide film is 6 m, but the present invention is not limited to this.

Claims

The scope of the claims

1. two facing transparent insulating substrates,

A transparent conductive film provided on the opposing surface of each transparent insulating substrate, and a spacer disposed between the transparent conductive films facing each other to form a space between the two transparent conductive films;

A liquid crystal display device, comprising: a liquid crystal layer filled in the space; and the spacer is formed on at least one of the transparent conductive films.

2. The liquid crystal display device according to claim 1,

The spacer is an oxide film.

3. The liquid crystal display device according to claim 2,

The oxide film is a silicon oxide film.

4. The liquid crystal display device according to claim 1,

The two transparent insulating substrates are plate materials having flexibility.

5. The liquid crystal display device according to claim 4,

The two transparent insulating substrates are made of a plastic material.

6. The liquid crystal display device according to claim 4,

The two transparent insulating substrates have curved surfaces.

7. A transparent conductive film is formed on each of the opposing surfaces of the two transparent insulating substrates that are used to face each other, and the two transparent insulating substrates are faced via a spacer, and are formed by a spacer. Liquid crystal layer in space In the method for manufacturing a liquid crystal display device configured by

A first step of forming a transparent conductive film on one side of one of the two transparent insulating substrates,

A second step of forming a transparent conductive film on one surface side of the other of the two transparent insulating substrates,

A third step of insulatingly covering the transparent conductive film with a spacer oxide film on the transparent insulating substrate on which the transparent conductive film is formed in the first step;

A fourth step of forming a mask on a predetermined portion of the spacer oxide film;

A fifth step of removing an unmasked portion of the oxide film for the spacer by etching to form an oxide film spacer;

A sixth step of removing said mask;

A seventh step of injecting a liquid crystal layer into a space where the oxide film spacer does not exist;

An eighth step of disposing the transparent insulating substrate, on which the transparent conductive film is formed in the second step, on the oxide film spacer and the liquid crystal layer with the transparent conductive film inside;

A method for manufacturing a liquid crystal display device, comprising:

8. In the method of manufacturing a liquid crystal display device according to claim 7, the spacer oxide film is a silicon oxide film.

9. A transparent conductive film is formed on each of the opposing surfaces of the two transparent insulating substrates to be used facing each other, and the two transparent insulating substrates are spacers. A liquid crystal display device comprising a liquid crystal layer in a space formed by a spacer,

A third step of forming a mask on a predetermined portion of the transparent conductive film formed in the first step;

A fourth step of growing an oxide film spacer on a non-mask portion of the transparent conductive film;

A fifth step of removing the mask;

A sixth step of injecting a liquid crystal layer into a space where the oxide film spacer does not exist;

A seventh step of disposing the transparent insulating substrate on which the transparent conductive film is formed in the second step on the oxide film spacer and the liquid crystal layer with the transparent conductive film inside;

A method for manufacturing a liquid crystal display device, comprising:

10. In the method for manufacturing a liquid crystal display device according to claim 9, the spacer oxide film is a silicon oxide film.