JPH05165055A - Picture element split type liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide a picture element split type liquid crystal display element, in which connection with normal picture element electrode is made after the picture element electrode or electrodes corresponding to a defective picture element is cut off. CONSTITUTION:In a picture element split type liquid crystal display element, an electrode 15 constituting picture elements is split into a plurality of picture element electrodes 151, 152 which are connected with source busses 19 parallelly through respective TFTs 16, whose drain electrodes 18 are connected with respective picture element electrodes 15 through respective bridging pieces 17 which are narrow and can easily be severed, wherein a source electrode is connected with the respective source busses 19 through bridging pieces 17 narrow and capable of being severed easily, and the picture element electrodes 151, 152 are connected with respective additional capacity electrodes 40 through bridging pieces 41 which are narrow and can easily be severed, and further the gate electrode is connected with a gate bus 18 and a metal for welding shortcircuiting is furnished in the neighborhood of the oppositely situated parts of adjoining picture element electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixel-divided liquid crystal display element, and more particularly to a pixel-divided liquid crystal display element in which a defective portion in the pixel-divided liquid crystal display element is separated and the pixel electrode is connected to a normal pixel electrode.

[0002]

2. Description of the Related Art A conventional liquid crystal display device will be briefly described with reference to FIGS. 1 and 2. A transparent substrate 11 and a transparent substrate 12 are arranged close to each other via a spacer 13. A pixel matrix of the transparent pixel electrode 15 is formed on the inner surface of the transparent substrate 11. A thin film transistor (TFT) 1 is provided on each of the transparent pixel electrodes 15.
6 are formed correspondingly. On the other hand, a transparent common electrode 17 is formed on the inner surface of the transparent substrate 12. The liquid crystal 14 is sealed between the transparent pixel electrode 15 and the transparent common electrode 17. The gate of the thin film transistor (TFT) 16 is the gate bus 1
8 and the source is connected to the source bus 19.
A large number of gate buses 18 and source buses 19 are formed orthogonal to each other as shown in the drawing. When a control signal is supplied to the gate bus 18 and a thin film transistor (TFT) 16 is turned on, if a voltage is applied between the transparent pixel electrode 15 and the transparent common electrode 17 corresponding thereto via the source bus 19, these It is configured such that the optical state of the liquid crystal between the electrodes changes. If necessary, an additional electrode 40 is extended from the end of the transparent pixel electrode 15 so as to overlap the gate bus 18 of the thin film transistor (TFT) 16 adjacent to the transparent pixel electrode 15, and an additional capacitance portion is provided between the additional electrode 40 and the gate bus 18. To form. It is in parallel with the capacitance formed between the transparent pixel electrode 15 and the transparent common electrode 17.

The manufacturing process of the liquid crystal display device will be briefly described with reference to FIG. The pixel electrode 15 and the source bus 19 are formed on the upper surface of the transparent substrate 11 by a transparent conductor such as ITO, and the pixel electrode 15 and the source bus 19 are further formed.
A semiconductor layer 23 that forms the TFT 16 is formed so as to straddle. A gate insulating film 24 made of silicon nitride is formed over all of these upper surfaces, a gate electrode 25 is formed on the upper surface of the insulating film 24 at a position corresponding to the semiconductor layer 23, and a gate bus connected to these gate electrodes 25 is formed. 18 is formed so as to be orthogonal to the source bus 19. The protective layer 26 is formed on the entire upper surface of the gate insulating film 24 including the gate electrode 25 and the gate bus 18. Then, liquid crystal is sealed between the protective layer 26 and the transparent common electrode 17.

[0004]

There is also a method in which a pixel is divided into a plurality of pixels, and even if a defective pixel occurs in the plurality of pixels, the defective pixel is not cut off and special repair is not performed. However, even if a pixel is divided into a large number of pixels, for example, 3 or 4, if a defect occurs in one of the pixels, it means that a defect of 1/3 pixel or 1/4 pixel has occurred. Therefore, even such a defect is easily recognized by the naked eye as a defect.

The present invention intends to provide a pixel-divided liquid crystal display device which solves the above-mentioned problems by separating a defective portion in the pixel-divided liquid crystal display device and connecting the pixel electrode to a normal pixel electrode. To do.

[0006]

Means for Solving the Problem Pixels are formed on the upper surface of the transparent substrate 11.
The electrode 15 and the source bus 19 are made of a transparent conductor.
And further straddles the pixel electrode 15 and the source bus 19.
Layer forming a thin film transistor (TFT) 16
23 is formed and is insulated on the upper surface of the transparent substrate 11 including them.
The film 24 is formed, and the semiconductor layer 23 on the upper surface of the insulating film 24 is formed.
The gate electrode 25 is formed at the location corresponding to
The source of the gate bus 18 connected to these gate electrodes 25
These gate electrodes 2 are formed so as to be orthogonal to the bus 19.
5 and the upper surface of the gate insulating film 24 including the gate bus 18
The protective layer 26 is formed on the transparent common electrode 17 and the protective layer 26.
In a pixel-divided liquid crystal display element in which liquid crystal is enclosed between
The electrodes forming the pixel are the plurality of pixel electrodes 15₁and
15₂Each pixel electrode 15₁And 15₂Haso
Thin film transistor (TFT) 16₁And 16
₂And connect to the source bus 19 in parallel via
Drain transistor of each thin film transistor (TFT)
Pole 18₁And 18₂Each is a narrow bridge that is easy to cut
Entanglement 17₁And 17₂Each pixel electrode 15
₁And 15₂Source electrode 19₁Oh
And 19₂Each is a narrow bridging piece 17 that can be easily cut.₁
And 17₂Connected to the source bus 19 by
Elementary electrode 15 ₁And 15₂Each has a narrow width for easy cutting
I Bridge 41₁And 41₂Each additional capacitance electrode 40
₁And 40₂The gate electrode is connected to
Pixel electrodes 15 adjacent to each other₁And pixels
Electrode 15₂Of welding short-circuiting gold near the parts of the
It has a genus.

As the welding short-circuit metal, the welding metal was provided in the pixel electrode 15, and the short-circuit metal 29 was provided on the upper surface of the transparent substrate or on the upper surface of the insulating film 24. In addition, the metal 30 for welding and short circuit is formed on the upper surface of the transparent substrate 11 and the insulating film 2.
4 was provided on the upper surface.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. Pixel electrodes divided into two pixel electrodes 15 ₁ and pixel electrode 15 ₂ is composed, each pixel electrode 15 ₁ and the pixel electrode 15 ₂ is connected via a thin film transistor (TFT) 16 ₁ and a thin film transistor (TFT) 16 ₂ Each of them is connected to the source bus 19 in parallel. Here, a thin film transistor (TFT) 16 ₁ of the drain electrode 18 ₁ is connected by narrow bridging piece 17 ₁ of scissile width to the pixel electrode 15 _1, the narrow bridging piece of the source electrode 19 ₁ scissile width 17 ₁ connects to the source bus 19 while
Drain electrode 18 of thin film transistor (TFT) 16 _2.
2 pixel electrode 1 by narrow bridging piece 17 ₂ of scissile width
5 ₂ as well as connected to the source electrode 19 ₂ is connected to the source bus 19 by a narrow bridging piece 17 ₂ of scissile width. Then, the pixel electrode 15 ₁ and its additional capacitance electrode 40
₁ and are interconnected by narrow bridging piece 41 ₁ of scissile width, the pixel electrode 15 ₂ and the additional capacitor electrode 40 ₂ and interconnected by narrow bridging piece 41 ₂ of scissile width There is.

In the present invention, as described above, the pixel electrode 15, the thin film transistor (TFT) 16 and the additional capacitance electrode 40 are respectively divided, and the thin film transistor (TFT) 16 and the additional capacitance electrode 40 are respectively connected to the source bus 19 and the source bus 19. The thin film transistor (T
When a defect occurs in the FT) 16 or the additional capacitance electrode 40, these are separated from the pixel electrode 15. Next, a defective thin film transistor (TFT) 16 or additional capacitance electrode 4
The pixel electrode from which these defective portions corresponding to 0 are separated is short-circuited to the normal pixel electrode. The method of separating the defective portion and short-circuiting the pixel electrode and the normal pixel electrode will be described below. ..

FIG. 5 is a view showing an AA cross section in the short-circuit connection portion. In the example of FIG. 5A, the transparent substrate 11
First, the metal layer 29 for short-circuit connection of the present invention is formed on the upper surface, and the insulating layer 22 is formed on the upper surface of the transparent substrate 11 including the metal layer 29 for short-circuit connection. The pixel electrode 15 and others are formed on the upper surface of the insulating layer 22 as described above. In the present invention, the metal for welding 28 ₁ and 28 ₂ are provided on both of the portions of the pixel electrode 15 ₁ and the pixel electrode 15 ₂ which are adjacent to each other and constitute the pixel, which face each other. By the way, the short-circuit connection metal layer 29 has a length that extends between the welding metals 28 ₁ and 28 ₂ . 24 is the pixel electrode 1
The insulating film is formed on the upper surface of the insulating layer 22 including 5 ₁ and the pixel electrode 15 ₂ .

In the example of FIG. 5B, the short-circuit connection metal layer 29 is used.
5A is different from the case of FIG. 5A, an example is shown in which it is formed not on the upper surface of the transparent substrate 11 but on the upper surface of the insulating layer 24. Unlike the case of FIGS. 5A and 5B, FIG. 5C is different from the case of FIG. 5A and FIG. 5B without using any special welding metal, and the welding / short circuit connecting metal layer 30 ₁ and the welding / short circuit connecting metal are provided. Layer 30
_In this example, 2 is formed on the upper surface of the transparent substrate 11 and the upper surface of the insulating layer 24.

[0012]

Here, for example, when a defect occurs in the additional capacitance portion near the additional capacitance electrode 40 ₁ , as shown in FIG.
In the example of (a), laser light is emitted from the transparent substrate 11 side in the direction of the arrow to focus the laser light on a narrow bridging piece 41 ₁ of the additional capacitance electrode 40 ₁ which can be easily cut, and the bridging piece 41 1
By disconnecting ₁ , the defective capacitance portion can be easily separated from the pixel electrode 15 ₁ . Next, in the welding process, after the defective capacitance portion is separated from the pixel electrode 15 ₁ , laser light is emitted in the direction of the arrow so that this laser light is focused next to the welding metal 28 ₁ , and the welding metal is welded. 28 ₁
This makes it possible to short-circuit connects the shorting connection metal layer 29 and the pixel electrode 15 ₁ by melting. The same operation is performed near the welding metal 28 ₂ . As a result, the welding metal 28 ₂ can be melted, and the pixel electrode 15 ₂ and the short-circuit connection metal layer 29 can be short-circuited in the same manner as described above. Eventually, the pixel electrode 15 ₁ from which the defective capacitance portion has been cut off is short-circuited to the normal pixel electrode 15 ₂ , and therefore the pixel electrode 15 ₁ from which the defective capacitance portion has been cut off from the normal pixel electrode 15 ₂ Since the display signal is applied, it is not necessary to cause a remarkable change in the entire area of the pixel electrode of the pixel.

In the example of FIG. 5B, the short-circuit connection metal layer 29 is arranged above the welding metal 28 ₁ and the welding metal 28 ₂ , but in this case as well, the example of FIG. after disconnecting the defective capacitor portion from the pixel electrode 15 ₁ as well as,
By applying the welding process described above, a short-circuit connection between the defective pixel electrode and the normal pixel electrode can be performed.

In the example of FIG. 5C, also in this case, after the defective capacitance portion is separated from the pixel electrode 15 ₁ , both ends of the metal layer 30 ₁ for welding and short-circuit connection and the metal layer 30 ₂ for welding and short-circuit connection are formed. By applying the above-described welding process to the portion, a short-circuit connection between the defective pixel electrode and the normal pixel electrode can be performed. Next, regarding the case where a defect occurs in the thin film transistor (TFT) 16 ₁ of the pixel electrode 15 ₁ , in this case, the thin film transistor (TF)
T) Focusing on the bridging piece 17 ₁ of 16 ₁ , the laser light is emitted from the transparent substrate 11 side in the direction of the arrow and focused on this.
The defective TFT can be easily separated from the pixel electrode 15 ₁ by cutting the bridging piece 17 ₁ . The subsequent welding process is no different from the case where a defect occurs in the additional capacity portion. Eventually, both the pixel electrode 15 ₁ and the additional capacitance electrode 40 ₁ from which the defective TFT is separated are short-circuited to the normal pixel electrode 15 ₂ , and therefore the defective TF is generated.
Pixel electrodes 15 T is detached ₁ and the additional capacitance electrode 4
Since the display signal is applied to the pixel electrode 15 ₂ that is normal to 0 ₁ , no change occurs in the total area of the pixel electrode of the pixel.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional example of a liquid crystal display element.

FIG. 2 is a diagram showing a pixel matrix of a liquid crystal display element.

FIG. 3 is a diagram showing a cross section taken along the line D-D in FIG. 2;

FIG. 4 is a diagram showing pixels of a pixel division liquid crystal display element of the present invention.

5 is a view showing a cross section taken along the line AA in the short-circuit connection portion of FIG. 4, (a) showing a metal layer for short-circuit connection arranged below a metal for welding, and (b) a short circuit. The figure which shows what the metal layer for connection was arrange | positioned above the metal for welding, (c).
FIG. 6 is a view showing a case where a metal layer for welding and short-circuit connection is used.

[Explanation of symbols]

 11 transparent substrate 14 liquid crystal 15 pixel electrode 16 thin film transistor (TFT) 17 transparent common electrode 18 gate bus 19 source bus 23 semiconductor layer 24 insulating film 25 gate electrode 26 protective layer 26

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 29/784

Claims (4)

[Claims] 1. A pixel electrode and a source bus are formed of a transparent conductor on the upper surface of a transparent substrate, and a semiconductor layer forming a thin film transistor is further formed across the pixel electrode and the source bus. An insulating film is formed on the upper surface of the transparent substrate including these. And forming a gate electrode at a position corresponding to the semiconductor layer on the upper surface of the insulating film, and forming a gate bus connected to these gate electrodes so as to be orthogonal to the source bus, and including the gate electrode and the gate bus. In a pixel-divided liquid crystal display element in which a protective layer is formed on the upper surface of a gate insulating film, and liquid crystal is sealed between the protective layer and a transparent common electrode, the electrodes forming pixels are divided into a plurality of pixel electrodes, The electrodes are separately connected in parallel to the source bus through the respective thin film transistors, and the drain electrode of each thin film transistor is Each is connected to each pixel electrode by a narrow bridging piece that can be easily cut, and the source electrode is connected to the source bus by a narrow bridging piece that is easy to cut. It is connected to each additional capacitance electrode by a narrow bridging piece, the gate electrode is connected to the gate bus, and the metal for welding short circuit is provided in the vicinity of the mutually opposing portions of the adjacent pixel electrodes. Pixel-divided liquid crystal display element. 2. The pixel-divided liquid crystal display element according to claim 1, wherein a welding metal is provided on the pixel electrode and a short-circuiting metal is provided on the upper surface of the transparent substrate. .. 3. The pixel-divided liquid crystal display element according to claim 1, wherein a welding metal is provided on the pixel electrode and a short-circuiting metal is provided on the upper surface of the insulating film. .. 4. The pixel-divided liquid crystal display element according to claim 1, wherein a metal for welding and short-circuiting is provided on the upper surface of the transparent substrate and the upper surface of the insulating film.