JPH11142875A - Liquid crystal display element and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain sure connection to a leading electrode of a counter substrate and to improve display quality in a liquid crystal display element using a transparent electrode of multilayer structure obtained by holding a metallic thin film between oxide thin films for a display electrode to be formed on a color filter substrate. SOLUTION: In a liquid crystal display element, a liquid crystal layer 12 of which periphery is sealed by sealing resin 8 and conductive paste 10 formed on a prescribed position are held between a 1st transparent substrate 2 forming active elements 7 and pixel electrodes 13 on its surface and a 2nd transparent substrate 1 prepared as a counter electrode and forming transparent electrodes on its surface. The electrode 2 has multilayer structre holding a metallic thin film 5 between oxide thin films 4, 6 and conductive particles 11 included in the paste 10 are directly brought into contact with the thin film 5 and a leading electrode 14 and electrically connected to them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device used for a video display device, an OA device such as a personal computer or a word processor, a handy terminal device in the industrial field, a portable information communication device, and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art Liquid crystal, plasma, and EL displays are currently in practical use as flat panel displays.
Its applications are becoming widespread. Among them, the liquid crystal display element can be positioned in a product field excellent in portability in terms of weight and volume, and has recently attracted attention as a monitor for CRT replacement due to an increase in screen size and display capacity.

[0003] Problems for use in monitors include wide viewing angles, low crosstalk, and high transmittance. 2
If the size exceeds 0, crosstalk becomes a problem even in an active type liquid crystal display device.

As one of the measures against the crosstalk, there is an approach of lowering the resistance of a transparent electrode on a color filter.
A transparent electrode having a multilayer structure in which a silver thin film is sandwiched between metal oxides as described in Japanese Patent Application Laid-Open Publication No. H10-157, has been devised.

A conventional liquid crystal display device using a transparent electrode having a multilayer structure will be described below. FIG. 2 shows a cross section of a terminal portion of a liquid crystal display element using a transparent electrode having a multilayer structure according to the prior art.

In FIG. 2, a transparent substrate 2 on which an active element 7, a pixel electrode 13 and an extraction electrode 14 are formed, a color filter 3, a metal oxide thin film 4, a metal thin film 5,
Seal resin 8 is provided between transparent metal substrate 1 on which a transparent electrode having a multilayer structure in which metal oxide thin films 6 are sequentially laminated is formed.
A liquid crystal display device is constructed by sandwiching a liquid crystal layer 12 sealed with a conductive paste 10 between an extraction electrode 14 of the transparent substrate 2 and a transparent electrode of the transparent substrate 1. Note that 9
Is a spacer for setting the distance between the transparent substrates 1 and 2.

[0007]

However, when such a transparent electrode having a multilayer structure is used, when a low-resistance transparent electrode typified by ITO is used as a metal oxide film sandwiching a metal thin film, an electrode is not formed. There is no problem in the connection of, but when a transparent thin film having a relatively high resistance value is used as the metal oxide thin film, the connection resistance with the extraction electrode increases,
There is a problem that display quality is deteriorated.

The present invention solves such a problem. Even when a transparent electrode having a multilayer structure in which a metal thin film is sandwiched between oxide thin films is used, its low resistance performance and good connection of a terminal portion are achieved. It is an object of the present invention to provide a liquid crystal display element and a method for manufacturing the same, which are compatible with each other.

[0009]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises a first substrate having an active element and a pixel electrode formed on one main surface, and a color filter formed on one main surface. A liquid crystal layer whose periphery is sealed with a sealant is sandwiched between a second substrate on which a transparent electrode as a counter electrode is formed, and an extraction electrode formed on the first substrate and the second electrode on the second substrate. A transparent electrode having a multilayer structure in which a metal thin film is sandwiched between oxide thin films, and the conductive paste contains conductive particles; The conductive particles are directly in contact with and electrically connected to the metal thin film having the multilayer structure.

According to the above construction, the use of a thin film electrode having a multilayer structure in which a metal thin film is sandwiched between oxide thin films makes it possible to reduce the resistance, and to provide a conductive material between the metal thin film and the extraction electrode. Since the conductive particles mixed into the paste are in direct contact and electrically connected, good conductivity can be obtained.

Further, in the method of manufacturing a liquid crystal display element according to the present invention, a first substrate having an active element and a pixel electrode formed on one main surface, a color filter on one main surface, and a metal thin film formed of an oxide thin film. A second substrate having a transparent electrode having a multilayer structure sandwiched therebetween is opposed to the second substrate, and a sealant for sealing a liquid crystal layer in a gap between the second substrate and the extraction electrode formed on the first substrate and the second substrate. After sandwiching a conductive paste containing conductive particles between the transparent electrodes of the substrate and bonding them together, the pressure is applied so that the conductive particles penetrate the oxide thin film of the multilayer structure and come into direct contact with the metal thin film, and the sealing agent is pressed. Is cured.

By adopting such a manufacturing method, it is possible to easily and surely conduct between the metal thin film and the extraction electrode via the conductive particles.

The metal thin film in the transparent electrode having a multilayer structure is preferably a silver thin film.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a cross section of a terminal portion of a liquid crystal display element according to an embodiment of the present invention.

First, the active element 7 is placed on the transparent substrate 2.
And the pixel electrode 13 and the extraction electrode 14 are formed. Next, a color filter 3 is formed on the transparent substrate 1, and a metal oxide thin film 4, a metal thin film 5, and a metal oxide thin film 6 are sequentially laminated thereon to form a transparent electrode. Here, SiO ₂ was used as the metal oxide thin films 4 and 6, and a silver thin film was used as the metal thin film 5. The thicknesses of the metal oxide thin film 4 were 500 °, the thickness of the metal thin film 5 was 150 °, and the thickness of the metal oxide thin film 6 was 500 °. Further, a conductive paste 10 containing a sealing resin 8 including a spacer 9 and conductive particles 11 (manufactured by Sekisui Fine Chemical: gold-plated micropearl) was formed at predetermined positions on the transparent substrate 1.

Next, the transparent substrate 1 and the transparent electrode 2 are bonded to each other, and the conductive particles 11 press through the oxide thin film 6 until the metal thin film 5 and the extraction electrode 14 are electrically connected. The resin 8 was cured to produce a liquid crystal cell. Finally, the liquid crystal layer 12 is filled in the gap to complete the liquid crystal display element.

It has been confirmed that the liquid crystal display device thus manufactured has a low crosstalk display due to the low resistance of the transparent electrode including the metal thin film 5. The conductive paste 10
Due to the conductive particles 11 inside, conduction from the transparent electrode to the extraction electrode 14 was also no problem.

In this embodiment, the multilayer thin film electrode has a multilayer structure of SiO ₂ / silver thin film / SiO ₂ , but the metal oxide thin film 6 of the transparent electrode may be made of another material as long as it is a transparent thin film. May be used. Moreover, as the metal thin film 5,
Silver, gold, copper, or an alloy thereof may be used. Further, another material may be used for the metal oxide thin film 4 as long as it is a transparent thin film and has good adhesion to the base. As a metal oxide thin film, for example, In ₂ O ₃ , TiO ₂ , ZrO ₂ ,
Ta ₂ O ₅ , Al ₂ O ₃ , Bi ₂ O ₃ or SiO ₂ is used.

[0019]

As described above, according to the present invention,
A multi-layer thin-film electrode in which a metal thin film is sandwiched between oxide thin films can be used as a display electrode of a liquid crystal display element. The unevenness can be reduced, and the electrical connection from the multilayer electrode to the extraction electrode can be secured by good contact via the conductive particles.

[Brief description of the drawings]

FIG. 1 is a sectional view of a terminal portion of a liquid crystal display element according to an embodiment of the present invention.

FIG. 2 is a sectional view of a terminal portion of a conventional liquid crystal display element.

[Explanation of symbols]

 1, transparent substrate 3 color filter 4, 6 metal oxide thin film 5 metal thin film 7 active element 8 sealing resin 9 spacer 10 conductive paste 11 conductive particles 12 liquid crystal layer 13 pixel electrode 14 extraction electrode

Claims (4)

[Claims] 1. A semiconductor device comprising: a first substrate having an active element and a pixel electrode formed on one main surface; and a second substrate having a color filter and a transparent electrode serving as a counter electrode formed on one main surface. A liquid crystal display element in which a liquid crystal layer whose periphery is sealed with a sealant is sandwiched and an extraction electrode formed on the first substrate and a transparent electrode of the second substrate are electrically connected by a conductive paste. The transparent electrode has a multilayer structure in which a metal thin film is sandwiched between oxide thin films, and the conductive paste contains conductive particles, and the conductive particles are in direct contact with and electrically connected to the metal thin film having the multilayer structure. A liquid crystal display device characterized in that: 2. The liquid crystal display element according to claim 1, wherein the metal thin film in the transparent electrode having a multilayer structure is a silver thin film, and the oxide thin film sandwiching the silver thin film is a transparent metal oxide thin film. . 3. A first substrate having active elements and pixel electrodes formed on one main surface, a color filter and a transparent electrode having a multilayer structure in which a metal thin film is sandwiched between oxide thin films is formed on one main surface. A sealing agent for sealing a liquid crystal layer in a gap between the second substrate and a conductive electrode between an extraction electrode formed on the first substrate and a transparent electrode of the second substrate. A liquid crystal display element, wherein the sealant is cured by applying pressure so that the conductive particles penetrate the oxide thin film of the multilayer structure and directly contact the metal thin film after bonding with a conductive paste. Manufacturing method. 4. The liquid crystal display device according to claim 3, wherein the metal thin film in the transparent electrode having a multilayer structure is a silver thin film, and the oxide thin film sandwiching the silver thin film is a transparent metal oxide thin film. Manufacturing method.