JPH11295748A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the contact with a signal wiring of a terminal formed on the signal wiring to have reliability by forming a conductive layer for the contact connected to the area where an anodized film is not formed of the signal wiring and also connected to the terminal. SOLUTION: A scanning signal wiring 3 is formed on a TFT substrate 1. The scanning signal wiring 3 is composed of an aluminum layer 3a and the anodized film 3b is formed on the surface by anodizing. The scanning signal wiring 3 is provided with the area where the anodized film 3b is not formed on the end part. Then, on the scanning signal wiring 3 where the anodized film 3b is formed separately from the area to a liquid crystal display part side, the conductive layer for constituting the terminal 3D for a gate inspection is formed. Further, the conductive layer 7 for the contact connected to the area where the anodized film 3b is not formed of the scanning signal wiring 3 and also connected to the terminal 3D for the gate inspection is superimposed on the scanning signal wiring 3 and formed.

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, and more particularly to a liquid crystal display device using aluminum having an anodized film formed on its surface as a signal wiring.

[0002]

2. Description of the Related Art For example, in an active matrix type liquid crystal display device, one of the transparent substrates disposed opposite to each other via a liquid crystal extends on the liquid crystal side surface thereof in the x direction and extends in the y direction. The pixel region is formed in a region surrounded by the scanning signal wirings arranged in parallel and the video signal wirings extending in the y direction and arranged in the x direction.

In each of these pixel regions, a switching element which is turned on by the supply of a scanning signal from the scanning signal wiring and a pixel electrode to which a video signal from the video signal wiring is supplied via the switching element are provided. Have.

In this case, aluminum is used as a material of the scanning signal wiring formed below the video signal wiring via the interlayer insulating film, and a short circuit with the video signal wiring due to the hillock of aluminum is prevented. ,
An anodized film (insulating film) formed on the surface by an anodizing method is known.

When a terminal is formed on a scanning signal wiring having such a configuration, a region that is not covered with an anodized film is relatively long along an end of the scanning signal wiring along the scanning signal wiring. A conductive layer (for example, an ITO film) forming a terminal is formed by being connected to an end of this region, and the scan signal wiring is not covered with anodized film so as to straddle the conductive layer. A conductive layer (for example, a chromium layer) for contact is formed in the portion.

For the conductive layer constituting the terminal, a material having relatively excellent mechanical strength is used, and if it is used alone, an oxide film (insulating film) is easily formed at the interface between the aluminum layer and the conductive layer. Good contact between the aluminum layer and the terminal is intended via the conductive layer for contact.

[0007]

However, when such a terminal is formed, an aluminum layer and an IT layer may be interposed via a conductive layer for contact, depending on the place where the terminal is formed.
It has been pointed out that the contact with the O film is often not sufficiently obtained. Then, as a result of investigating this cause, the following was found.

For example, when the terminal is a terminal for inspection, the terminal for inspection is a sealing material formed between a liquid crystal display portion, which is an aggregate of pixel regions, and another transparent substrate disposed opposite to the terminal. Is formed in a narrow space between them.

The portion of the signal wiring on which the inspection terminal is to be formed, including the vicinity thereof, must be formed with a region where no anodized film is formed. A method of performing anodization while covering with a photoresist film has been adopted.

In this case, the photoresist film must be arranged at a certain distance from the liquid crystal display unit. However, the position of the photoresist film is often shifted and the area where the anodized film is not formed is narrowed. In the region, the connection with the conductive layer for contact becomes insufficient.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal display device in which terminals formed on a signal wiring have reliable contacts with the signal wiring. It is in.

[0012]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. That is, a signal wiring made of aluminum having an anodized film formed on the surface is provided on the liquid crystal side surface of one of the transparent substrates disposed opposite to each other via the liquid crystal, and a signal is transmitted to the signal wiring. In a liquid crystal display device provided with a supply terminal, the signal wiring has an area where the anodized film is not formed at an end thereof, and the anodized film is formed separately from the area. A conductive layer forming the terminal is formed on the signal wiring, and a contact conductive layer connected to the region where the anodized film of the signal wiring is not formed, and connected to the terminal, It is characterized by being formed.

In the liquid crystal display device having such a configuration, the terminal formed on the signal line is arranged in the middle of the extension of the signal line, and the anodized film of the signal line is not formed. Is a portion on the side that does not actually function as a signal line with respect to the terminal.

This means that the terminal is formed in the region where the anodized film is formed, and when considered in the same space, it is the region where the anodized film is not formed. As a result, the area for contact with the terminal can be increased.

Therefore, in the case where the region where the anodized film of the signal line is not formed is formed by applying a photoresist film, even if the photoresist film is displaced, the anodized film is formed. It is possible to prevent the area where no part is formed from being significantly reduced.

Thus, the conductive layer for making contact between the signal line and the terminal can be sufficiently connected to aluminum in a region where the anodized film is not formed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the liquid crystal display device according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG . [TFT Substrate] FIG. 2 shows a liquid crystal display device according to the present invention.
FIG. 2 is a schematic plan view showing a configuration of a liquid crystal side surface of one transparent substrate 1 (TFT substrate) among transparent substrates arranged to face each other via a liquid crystal.

When the TFT substrate 1 shown in FIG. 1 is assembled into a liquid crystal display device, the periphery thereof is cut off from the portion indicated by the dotted line 2 in the figure. As described later, the TFT substrate 1 is cut around the periphery of the TFT substrate 1 to be cut.
Inspection common terminals (common terminals for gate inspection 3C, common terminals for drain inspection 4C, 4E) for inspecting disconnection or short-circuit of various signal wirings formed on the substrate 1 are formed, and are assembled in a liquid crystal display device. Are unnecessary.

In FIG. 1, scanning signal wirings 3 extending in the x direction and juxtaposed in the y direction are formed on the main surface (surface on the liquid crystal side) of the TFT substrate 1. And a video signal wiring 4 extending in the y direction and juxtaposed in the x direction is formed.

Each of the rectangular areas surrounded by the scanning signal wiring 3 and the video signal wiring 4 constitutes a pixel area, and the liquid crystal display unit 10 is constituted by an aggregate of these pixel areas. The configuration of each of these pixel regions will be described later in detail.

The liquid crystal display unit 1 of each scanning signal wiring 3
One end extending from 0 to the left in the figure is connected to the gate inspection common terminal 3C via the gate external terminal 3A. The gate external terminal 3A is disposed inside the cut portion (dotted line 2) of the TFT substrate 1, and the gate inspection common terminal 3C is disposed outside the cut portion of the TFT substrate 1.

The liquid crystal display section 10 of each scanning signal wiring 3
Gate inspection terminals 3D are formed at the other ends extending from the right side to the right side in the drawing. Here, the portion of each scanning signal line 3 extending from the liquid crystal display section 10 to the right side in the figure is formed close to the cut portion (dotted line 2) of the TFT substrate, whereas the inspection terminal 3D Is the liquid crystal display section 10
Is provided in the vicinity. This inspection terminal 3D will be described later in detail.

Further, the video signal wiring 4 is also connected to the scanning signal wiring 3.
The common terminal, the external terminal, and the terminal for inspection are formed in the same manner as described above, but the odd-numbered video signal wiring 4 and the even-numbered video signal wiring have external terminals on the upper side and lower side in the drawing, respectively. Since they are formed on the side, a common inspection terminal and an inspection terminal are also formed accordingly.

That is, for example, the other ends of the odd-numbered video signal wirings 4 extending downward from the liquid crystal display section 10 in the figure are connected to a common drain inspection terminal 4C via a drain external terminal 4A. I have. The drain external terminal 4A is arranged inside the cut portion (dotted line 2) of the TFT substrate 1, and the drain inspection common terminal 4C is arranged outside the cut portion of the TFT substrate 1.

Drain inspection terminals 4D are provided at the other ends of the odd-numbered video signal wirings 4 extending upward from the liquid crystal display section 10 in the drawing.

The other ends of the even-numbered video signal wires 4 extending upward from the liquid crystal display 10 in the figure are connected to a common drain test terminal 4E via a drain external terminal 4B.
It is connected to the. The drain external terminal 4B is arranged inside the cut portion (dotted line 2) of the TFT substrate 1, and the drain inspection common terminal 4E is arranged outside the cut portion of the TFT substrate 1.

Drain inspection terminals 4F are provided at the other ends of the even-numbered video signal wirings 4 extending downward from the liquid crystal display section 10 in the figure.

As described above, the positions of the terminals in the odd-numbered and even-numbered video signal wirings 4 are different from each other in that the spacing between the video signal wirings 4 is smaller than the spacing between the scanning signal wirings 3. Because there is.

After the formation of the scanning signal wiring 3 and the video signal wiring 4, an inspection is performed as to whether or not the signal wiring is disconnected, for example, as follows.

First, whether or not each of the scanning signal wirings 3 is disconnected is determined by contacting one of the probes to the common gate inspection terminal 3C and the other to the gate inspection terminal 3D of each scanning signal wiring. Abut the probe,
It is determined by the value of the current flowing between these probes. The same applies to the case of the video signal wiring 4.

The scanning signal wiring 3 and the video signal wiring 4
Is short-circuited with the common terminal 3C for gate inspection.
And the other probe is brought into contact with the drain inspection common terminal 4C (or 4E), and the determination is made based on the current value flowing between these probes.

Although not shown, such a TF
A black matrix formed so as to define each pixel area, a color filter which exhibits a color corresponding to each pixel area, and each pixel area A transparent common electrode and the like common to the above are formed.

In this case, the other transparent substrate is arranged so that its periphery coincides with the location shown by the dashed line 20 in FIG. 2, and is fixed to the TFT substrate 1 by the sealing material interposed at the location. It has become.

[Pixel Region] FIG. 3 is a plan view showing an embodiment of the configuration of the pixel region. In FIG.
There is a scanning signal line 3 extending in the direction and juxtaposed in the y direction. The scanning signal line 3 is made of aluminum, and the surface thereof is formed with an anodized film (aluminum oxide film) by an anodizing method. .

The reason why the anodized film is formed is that the hillock peculiar to aluminum is formed by heat treatment.
This is to prevent the occurrence of a short circuit between the signal lines, which is generated by penetrating the interlayer insulating film at the intersection with the video signal line 4 to be formed later.

An insulating film is formed on the entire surface of the substrate so as to cover the scanning signal wiring 4.

This insulating film functions as an interlayer insulating film of the scanning signal wiring 3 with respect to the video signal wiring 4 to be formed later, and also functions as a gate insulating film in a region where the thin film transistor TFT is formed. The region where the capacitive element Cadd is formed functions as a dielectric film.

The pixel electrode 5 is provided on the surface of the insulating film.
Is formed, and the pixel electrode 5 is made of, for example, ITO (Indium).
-Tin-Oxide) film. The pixel electrode 5 is formed such that a part thereof overlaps one of the scanning signal lines 3 (the upper signal line in the drawing), and an insulating film disposed therebetween is used as a dielectric film. This constitutes a capacitive element Cadd.

The formation region of the thin film transistor TFT is formed so as to overlap with one of the scanning signal lines 3 (the lower signal line in the figure), and an island-like semiconductor layer 6 made of, for example, amorphous Si is formed in this region. ing. The drain electrode 4d and the source electrode 4
By forming s, an MIS transistor having a part of the scanning signal wiring 3 as a gate electrode is formed. The drain electrode 4d and the source electrode 4s are formed together with the video signal wiring. I have.

That is, the video signal lines 4 extending in the y direction and juxtaposed in the x direction are formed. The video signal wiring 4 has, for example, a two-layer structure in which Al is stacked on Cr.

A part of the video signal wiring 4 extends to the surface of the semiconductor layer 6 in the region where the thin film transistor TFT is formed to form a drain electrode 4d.

At this time, the source electrode 4s formed simultaneously extends to the pixel region side, and can be connected to the pixel electrode 5 formed in advance.

Further, a protective film made of, for example, a silicon nitride film is formed on the entire surface of the substrate thus processed, and an alignment film for regulating the alignment of the liquid crystal is formed on the upper surface of the protective film. ing.

In the pixel region thus formed, the thin film transistor TFT is driven by the supply of the scanning signal from the scanning signal line 3, and the thin film transistor T
The video signal from the video signal wiring via the FT is
It is supplied to.

When the thin film transistor TFT is turned off, the video signal supplied to the pixel electrode 5 is applied to the additional capacitive element C
The data is accumulated for a long time by add.

[Gate Inspection Terminal] FIG. 1 is a structural view showing an embodiment of the gate inspection terminal 3D, and FIG. 1B is a plan view, and is a cross section taken along line aa of FIG. FIG.

In the figure, first, a scanning signal wiring 3 is formed on a TFT substrate 1. The scanning signal wiring 3 is made of an aluminum layer 3a, and an anodized film 3b (aluminum oxide layer) is formed on the surface by anodization.

The scanning signal wiring 3 having such a structure has a region where the anodized film 3b is not formed at its end (the end extending from the liquid crystal display unit 10). A conductive layer constituting the gate inspection terminal 3D is formed of, for example, an ITO film on the scanning signal wiring 3 on which the anodized film 3b is formed, separated from the liquid crystal display unit 10 side.

Further, the anodized film 3b of the scanning signal wiring 3 is formed.
The contact conductive layer 7 connected to the region where no is formed and connected to the gate inspection terminal 3D is formed so as to overlap the scanning signal wiring 3.

The contact conductive layer 7 is made of, for example, Cr.
Of a two-layer structure in which Al is formed on the upper layer.

[Method of Manufacturing Gate Inspection Terminal] FIG.
FIG. 4 is a process diagram showing one embodiment of a method for manufacturing the gate inspection terminal.

Step 1 (FIG. 7A) An aluminum film 3a is coated on the entire surface of the TFT substrate 1, and this aluminum film is formed into a pattern of the scanning signal wiring 3 by a selective etching method using a well-known photolithography technique. I do.

Then, a photoresist film 30 is formed on the scanning signal wiring 3 at the end on the side where the gate inspection terminal 3D is to be formed by a known photolithography technique.

FIG. 5 shows an overall plan view of the TFT substrate 1 in this case. Gate inspection terminal 3D of scanning signal wiring 3
Is provided on one end side of the scanning signal wiring 3, so that the photoresist film 3
0 is formed as a band-shaped pattern crossing each scanning signal wiring 3.

Step 2 (FIG. 10B) Each scanning signal wiring 3 is formed by using the gate inspection common terminal 3C formed on the other end of the scanning signal wiring 3 as an electrode.
To form an anodized film 3b on the surface of the scanning signal wiring 3 made of the aluminum layer 3a. In this case, an anodized film is not formed on the portion of the scanning signal wiring 3 covered with the photoresist film.

Step 3 (FIG. 3C) The photoresist film 30 is peeled off. As a result, a region where the anodized film is not formed is exposed on the scanning signal wiring 3.

Thereafter, an ITO film constituting a gate inspection terminal 3D is formed on the scanning signal wiring 3 on which the anodized film 3b is formed so as to be separated from the region.

This ITO film is formed at the same time when the pixel electrode 5 is formed. This is to avoid an increase in the number of manufacturing steps.

Then, the anodized film 3b of the scanning signal wiring 3 is formed.
A conductive layer for contact connected to the region where is not formed and connected to the gate inspection terminal 3D is formed.

The contact conductive layer has a two-layer structure composed of Cr and Al thereon, and is formed at the same time when the video signal wiring is formed. This is to avoid an increase in the number of manufacturing steps.

The gate inspection terminal 3D thus formed is disposed in the middle of the extension of the scanning signal wiring 3, and the region where the anodized film of the scanning signal wiring 3 is not formed is the gate inspection terminal 3D. This is a portion on the side that does not actually function as the scanning signal wiring 3 with respect to the inspection terminal 3D.

This means that the gate inspection terminal 3D is formed in the region where the anodized film is formed, and when considered in the same space, the anodized film is formed. It is possible to increase the area where no contact is made with the terminal.

For comparison, FIG. 6 shows a configuration of a conventional gate inspection terminal corresponding to FIG.

Therefore, when the region where the anodized film of the scanning signal wiring 3 is not formed is formed by depositing the photoresist film 30, even if the photoresist film 30 is displaced, The region where the chemical film is not formed is not significantly reduced.

Thus, the conductive layer 7 for making contact between the scanning signal wiring 3 and the gate inspection terminal 3D can be sufficiently connected to aluminum in a region where the anodized film is not formed.

[Gate External Terminal] FIG. 2 is a structural view showing an embodiment of the gate external terminal 3A. FIG. 2 (b) is a plan view, and FIG. 2 (a) is aa of FIG. 2 (b). It is sectional drawing in a line.

Since the gate external terminal 3A is positioned around the TFT substrate 1 from which it is cut,
The contact conductive layer 7 required for connecting the scanning signal wiring 3 to the aluminum layer 3a is provided on the scanning signal wiring 3 side with respect to the gate external terminal 3A.

That is, there is a region where no anodized film is formed at the extending end of the scanning signal wiring 3, so that the one end where the aluminum layer 3 a is exposed is ITO.
A part of the gate external terminal 3A made of a film is overlapped.

Then, a contact conductive layer 7 is formed so as to overlap the scanning signal wiring 3 where the aluminum layer 3a is exposed, and one end of the conductive layer 7 is overlapped with the gate external terminal 3A. .

[Drain Inspection Terminal] FIG. 8 is a sectional view showing an embodiment of the drain inspection terminals 4D and 4F. In the figure, on the surface of the TFT substrate 1, there are drain inspection terminals 4D and 4F made of an ITO film. The drain inspection terminals 4D and 4F are formed simultaneously with the pixel electrode 5.

The video signal wiring 4 extends to the drain inspection terminals 4D and 4F, and one end thereof is formed so as to overlap a part of the drain inspection terminals 4D and 4F.

The drain external terminals 4A and 4B have exactly the same configuration as the drain inspection terminal.

Embodiment 2 FIG . FIG. 9 is a plan view showing another embodiment of the liquid crystal display device according to the present invention. The figure shows the so-called COG (Chip On glass)
s) A liquid crystal display device referred to as a method, wherein an output electrode of a semiconductor IC is formed at a gate external terminal connected to a scanning signal line and connected to an input electrode of the semiconductor IC. The wiring is also formed on the TFT substrate 1 surface.

That is, the semiconductor IC for driving the liquid crystal is TF
It has a structure mounted on a T substrate.

FIG. 10 is a sectional view taken along line XX of FIG. In the figure, the gate external terminal 3D ′ connected to the scanning signal wiring 3 is the above-described gate inspection external terminal 3D.
The contact conductive layer 7 ′ for connecting the aluminum layer of the scanning signal wiring 3 to the gate external terminal is provided in the mounting area of the semiconductor IC 40.

The thus configured gate external terminal 3D
Effectively utilizes the mounting area of a semiconductor IC, which tends to be a so-called dead pace, and includes a contact conductive layer 7 ′
Is provided, a reliable contact between the scanning signal wiring 3 and the gate external terminal 3D 'is achieved.

Although the external terminals 3D ″ of the wiring connected to the electrodes on the input side of the semiconductor IC are not configured as described above, the number of the external terminals 3D ″ is extremely small. The line width of the external terminal 3D ″ can be formed relatively large.

This means that the reliability of the contact between the wiring formed by the contact conductive layer 7 ′ and the external terminal is relatively high.
This is based on the fact that the configuration described above is not necessary.

In each of the above-described embodiments, the scanning signal wiring is made of an aluminum layer and an anodized film is formed on the surface thereof. However, such a configuration can be adopted in the video signal wiring.

In this case, it goes without saying that the present invention can be applied to the drain inspection terminal or the drain external terminal formed on the terminal.

[0082]

As is apparent from the above description,
ADVANTAGE OF THE INVENTION According to the liquid crystal display device by this invention, the contact of the terminal formed in the signal wiring with the said signal wiring can be given reliability.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a schematic plan view showing one embodiment of a TFT substrate of the liquid crystal display device according to the present invention.

FIG. 3 is a plan view showing one embodiment of a pixel region of the liquid crystal display device according to the present invention.

FIG. 4 is a main part process view showing one embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 5 is a plan view showing one embodiment of one step in a method of manufacturing a liquid crystal display device according to the present invention.

6 is a plan view showing an example of one process in a conventional method for manufacturing a liquid crystal display device, and is a diagram corresponding to FIG.

FIG. 7 is a configuration diagram showing one embodiment of a gate external terminal of the liquid crystal display device according to the present invention.

FIG. 8 is a configuration diagram showing one embodiment of a drain inspection terminal of the liquid crystal display device according to the present invention.

FIG. 9 is a plan view of a principal part showing another embodiment of the liquid crystal display device according to the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... TFT substrate, 3 ... scanning signal wiring, 3a ... aluminum layer, 3b ... anodized film formation, 3D ... gate inspection terminal,
7 ... Contact conductive layer.

Claims (5)

[Claims] 1. A signal wiring made of aluminum having an anodized film formed on a surface thereof, on a liquid crystal side surface of one of the transparent substrates disposed opposite to each other with a liquid crystal interposed therebetween. In the liquid crystal display device provided with a terminal for supplying a signal to the liquid crystal display device, the signal wiring has a region where the anodized film is not formed at an end thereof, and is separated from the region to form the anodized film. A conductive layer constituting the terminal is formed on the signal wiring on which the terminal is formed, and the contact is connected to the region where the anodized film of the signal wiring is not formed, and is connected to the terminal. A liquid crystal display device comprising a conductive layer. 2. The liquid crystal display device according to claim 1, wherein the conductive layer forming the terminal is made of an ITO film. 3. The liquid crystal display device according to claim 1, wherein the terminal is a terminal for testing a signal wiring. 4. The terminal according to claim 1, wherein the terminal is a terminal for supplying a signal for driving a liquid crystal to a signal wiring.
The liquid crystal display device as described in the above. 5. The liquid crystal display device according to claim 4, wherein the terminal is connected to an output electrode of a semiconductor IC, and the contact conductive layer is formed in a mounting area of the semiconductor IC.