JPH08220551A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE: To provide the liquid crystal display panel which permits no orientation film to be peeled off even if rubbing is processed, allows liquid crystals to be uniformly oriented, prevents a display electrode and a second electrode from being contaminated by any peeled-off orientation film, and is provided with excellent display characteristics and excellent electric characteristics. CONSTITUTION: The liquid crystal display panel includes a first electrode 13 connected to a wiring electrode 12, an insulating film provided with the first electrode 13, and a displaying electrode 14, the displaying electrode 14 is connected to a second electrode 15 provided for the insulating film, an area where the first electrode 13 is piled up to the second electrode 15, is made to be an element section 17 composed of the first electrode 13, the insulating film, and of the second electrode 15, and a third electrode 16 is provided on the wiring electrode 12, and on the first electrode 13 of a non-element section which does not form the second electrode 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a liquid crystal display panel having a TFD element having a metal-insulator-metal structure in each pixel, and more particularly, to a wiring electrode and a TFD element portion.
And the structure of the electrodes.

[0002]

2. Description of the Related Art A structure of a substrate 1 of a liquid crystal display panel using a conventional TFD element will be described with reference to a plan view of FIG. 3 and a sectional view of FIG. The cross-sectional view of FIG. 4 shows a cross section taken along the line BB of FIG.

On the substrate 1, a wiring electrode 12 provided on the transparent substrate 11, a first electrode 13 which is a part of the wiring electrode 12, a display electrode 14, and a portion of the display electrode 14 are provided. The second electrode 15 and the element portion 17 formed at the overlapping portion of the first electrode 13 and the second electrode 15.

As shown in the sectional view of FIG. 4, the element portion 17 includes a first electrode 13 which is a part of the wiring electrode 12 formed of a tantalum (Ta) film, and tantalum oxide (Ta ₂ O ₅ ).
The insulating film 18 on the first electrode 13 made of a film and the second electrode 15 made of a part of the display electrode 14 covering the insulating film 18 are provided.

Here, the insulating film 18 on the first electrode 13 is
Since the wiring electrode 12 is formed by anodizing, the insulating film 18 made of tantalum oxide is also provided on the wiring electrode 12.

The display electrode 14 and the second electrode 15 are formed of an indium tin oxide (ITO) film which is a transparent electrode film.

Further, on the substrate 1, an alignment film 19 is provided on the entire surface in order to uniformly align the liquid crystal. This alignment film 1
9 is formed by forming a heat resistant polymer film such as polyimide by a printing method and performing a predetermined alignment treatment by rubbing treatment.

Here, the rubbing treatment is a method in which a cloth such as rayon or cotton is wound around a roll and the alignment film 19 is rubbed with a predetermined pressing pressure while rotating the roll at a high speed. Therefore, the alignment film 19 needs to have sufficiently strong adhesion to the base film.

[0009]

The structure of the substrate 1 of the liquid crystal display panel using the conventional TFD element is the wiring electrode 12 and the first electrode 13 of the non-element portion where the second electrode 15 is not formed. Is provided with an insulating film 18 made of a tantalum oxide film by anodizing treatment.

The surface shape of the insulating film 18 has a smooth shape when microscopically observed using an atomic force microscope (AFM).

Therefore, the alignment film 1 is formed on the insulating film 18.
When 9 is printed and a rubbing process is performed, the adhesion between the insulating film 18 and the alignment film 19 is extremely poor, and the alignment film 19 is peeled off, so that the liquid crystal cannot be aligned uniformly.

The alignment film 19 that has been peeled off and has become a minute foreign substance adheres to the display electrode 14 and the second electrode 15,
It causes the liquid crystal to be contaminated. Therefore, there is a problem that display characteristics and electric characteristics of the liquid crystal display panel are deteriorated.

An object of the present invention is to solve the above problems and to provide a first non-element portion on a wiring electrode and on which a second electrode is not formed.
The purpose of the present invention is to provide a structure of a liquid crystal display panel using a high-quality TFD element, which makes it possible to obtain a good adhesion of the alignment film on the electrode.

[0014]

In order to achieve the above object, the substrate of the liquid crystal display panel of the present invention adopts the following constitution.

The substrate of the liquid crystal display panel of the present invention has a first electrode connected to the wiring electrode, an insulating film provided on the first electrode, and a display electrode, and the display electrode is on the insulating film. Connected to a second electrode provided in the first electrode, an overlapping region of the first electrode and the second electrode is used as an element portion including the first electrode, the insulating film, and the second electrode, and is formed on the wiring electrode and the first electrode. The third electrode is provided on the first electrode of the non-element portion where the second electrode is not formed.

[0016]

In the substrate of the liquid crystal display panel of the present invention, the third electrode made of an indium tin oxide film is provided on the wiring electrode and the first electrode of the non-element portion where the second electrode is not formed. The structure will be adopted.

When the surface shape of this indium tin oxide film is observed with an atomic force microscope, it has microscopically fine irregularities, so that the adhesion with the alignment film is good.

As a result, the alignment film printed on the wiring electrode and the first electrode of the non-element portion where the second electrode is not formed has the indium tin oxide film as the underlying layer.

Therefore, even if the alignment treatment by the rubbing treatment is performed, the liquid crystal is not peeled off, the liquid crystal is uniformly aligned, and the peeled product of the alignment film does not contaminate the display electrode or the second electrode, which is excellent. It is possible to obtain display characteristics and excellent electrical characteristics.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.
The structure of the liquid crystal display panel using the TFD element will be described.

FIG. 1 is a plan view showing a liquid crystal display panel according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a liquid crystal display panel according to the embodiment of the present invention. Figure 2
FIG. 2 is a cross-sectional view showing a cross section taken along the line AA of FIG. 1.
Hereinafter, description will be made by alternately using FIG. 1 and FIG.

The wiring electrode 12 is formed on the transparent substrate 11 of the substrate 1.
And a first electrode 13 which is a part of the wiring electrode 12. The wiring electrode 12 and the first electrode 13 are made of a tantalum film.

Further, a display electrode 14 and a second electrode 15 which is a part of the display electrode 14 are provided. The display electrode 14 and the second electrode 15 are composed of an indium tin oxide film.

An insulating film 18 is provided on the wiring electrode 12 and the first electrode 13. As a result, the first electrode 13 is formed in the region where the first electrode 13 and the second electrode 15 intersect.
It is possible to provide the element portion 17 including the TFD element including the insulating film 18 and the second electrode 15.

The insulating film 18 is composed of a tantalum oxide film formed by anodizing the wiring electrode 12 and the first electrode 13.

Further, on the wiring electrode 12 and the second electrode 15
On the first electrode 13 in the non-element portion where
A third electrode 16 made of an indium tin oxide film made of the same material as the display electrode 14 and the second electrode 15 is provided.

Further, an alignment film 19 for uniformly aligning the liquid crystal is formed on the entire surface of the substrate 1. The alignment film 19 is formed by performing a predetermined alignment process by a rubbing process.

At this time, the alignment film 19 on the wiring electrode 12 and on the first electrode 13 in the non-element portion where the second electrode 15 is not formed has an indium tin oxide film as a base.

Therefore, the alignment film 19 is not peeled off even if the alignment process is performed by the rubbing process, and the liquid crystal is uniformly aligned. Furthermore, a peeled product of the alignment film 19 does not contaminate the display electrode 14 and the second electrode 15, and a liquid crystal display panel having excellent display characteristics and electrical characteristics can be obtained.

Next, a manufacturing method for obtaining the structure of the liquid crystal display panel of the present invention shown in FIGS. 1 and 2 will be briefly described.

First, a tantalum film is formed on the entire surface of the substrate 1 by a sputtering method, and then the tantalum film is patterned by using a photoetching technique, and the wiring electrode 12 made of the tantalum film and the first electrode 13 are formed.
And are formed at the same time.

Thereafter, the tantalum film of the wiring electrode 12 and the first electrode 13 is anodized to form an insulating film 18 made of a tantalum oxide film on the surfaces of the wiring electrode 12 and the first electrode 13.

After that, an indium tin oxide film is formed as a transparent electrode film on the entire surface by a vacuum evaporation method.

Then, the indium tin oxide film is patterned by using the photoetching technique to form the display electrode 14 and the second electrode 15 provided on the insulating film 18.

Simultaneously with the formation of the display electrode 14 and the second electrode 15, an indium tin oxide film is formed on the wiring electrode 12 and the first electrode 13 of the non-element portion where the second electrode 15 is not formed. And the third electrode 16 is formed.

Further, a polyimide film is formed on the substrate 1 by a flexographic printing method, an alignment process is performed by a rubbing process, and an alignment film 19 for aligning liquid crystals is formed to obtain a liquid crystal display panel.

[0037]

As is clear from the above description, in the liquid crystal display panel of the present invention, indium tin oxide is provided on the wiring electrode and the first electrode of the non-element portion where the second electrode is not formed. Provide a membrane.

Therefore, the alignment film formed on the indium tin oxide film is excellent in adhesiveness, and the alignment film is not peeled off even if the rubbing treatment is performed, and the liquid crystal is uniformly aligned.

Furthermore, the exfoliated product of the alignment film is a display electrode or a second electrode.
It is possible to obtain a liquid crystal display panel having excellent display characteristics and excellent electric characteristics without contaminating the electrodes of (1).

[Brief description of drawings]

FIG. 1 is a plan view showing a liquid crystal display panel in an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a liquid crystal display panel in an example of the present invention.

FIG. 3 is a plan view showing a liquid crystal display panel in a conventional example.

FIG. 4 is a cross-sectional view showing a liquid crystal display panel in a conventional example.

[Explanation of reference numerals] 11 transparent substrate 12 wiring electrode 13 first electrode 14 display electrode 15 second electrode 16 third electrode 18 insulating film 19 alignment film

Claims (3)

[Claims] 1. A first electrode connected to the wiring electrode, and a first electrode.
Has an insulating film provided on the electrode and a display electrode, the display electrode is connected to a second electrode provided on the insulating film, and an overlapping region of the first electrode and the second electrode is An element portion including a first electrode, an insulating film, and a second electrode is provided, and a third electrode is provided over the wiring electrode and the first electrode of the non-element portion where the second electrode is not formed. Liquid crystal display panel characterized by. 2. A first electrode made of a tantalum film connected to a wiring electrode made of a tantalum film, an insulating film made of a tantalum oxide film provided on the first electrode, and a display electrode made of an indium tin oxide film. And the display electrode is connected to the second electrode made of an indium tin oxide film provided on the insulating film, and the overlapping region of the first electrode and the second electrode is
An element portion including a first electrode, an insulating film, and a second electrode is formed, and an indium tin oxide film is formed on the wiring electrode and the first electrode of the non-element portion where the second electrode is not formed. Three
A liquid crystal display panel, which is provided with the electrodes of. 3. A first electrode connected to the wiring electrode, and a first electrode.
Has an insulating film provided on the electrode and a display electrode, the display electrode is connected to a second electrode provided on the insulating film, and an overlapping region of the first electrode and the second electrode is An element portion composed of a first electrode, an insulating film, and a second electrode is formed, and a wiring electrode and a first electrode located on the wiring electrode side of a non-element portion where the second electrode is not formed are provided. A liquid crystal display panel, which is provided with three electrodes.