JP2002357843A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display panel in which line defects due to metallic foreign matter are reduced and which has high reliability. SOLUTION: In a liquid crystal display panel which is constituted by sticking together a common electrode substrate on whose transparent substrate a transparent metal film layer is formed and an array substrate on whose transparent substrate an array chip having signal line groups of an X direction and a Y direction is formed across liquid crystal, the transparent metal film layer 5A formed on the common electrode substrate has areas 5B where the transparent metal film layer does not exist at parts opposed to the signal line groups of the array substrate. Even when the metallic foreign matter is stuck to gate signal lines or source signal lines, since the transparent metal layer which is to be confronted with them does not exist, the gate signal lines or the source signal lines are never short-circuited with the common electrode substrate and defects due to counter short circuits are decreased sharply in this display panel.

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 panel, and more particularly to a common electrode substrate (corresponding to a color filter substrate) bonded to an array substrate.

[0002]

2. Description of the Related Art An example of a conventional liquid crystal display panel of this type will be described with reference to FIGS. FIG. 4 shows the common electrode substrate 1 within the effective screen of the liquid crystal display panel. A black matrix (hereinafter abbreviated as BM) layer 3A is formed on a glass substrate 2. Reference numeral 3B denotes an opening which transmits light without forming a BM layer. Thereafter, a color layer 4 composed of a red color layer 4A, a green color layer 4B, and a blue color layer 4C mainly containing a pigment resin is formed in the opening 3B.
The upper part and a part of the pattern of each color layer 4 are sequentially laminated and formed so as to cover the BM layer 3A. Next, a transparent metal film layer 5A made of ITO is uniformly formed on the entire surface of the BM layer 3A and the opening 3B. The transparent metal film layer 5A constitutes a common electrode. FIG. 5 shows a plan view of the common electrode substrate 1 (however, the pattern of the color layer 4 is omitted), and the openings 3B are arranged in an XY matrix.

In a liquid crystal display panel using the common electrode substrate 1, an array substrate on which one or a plurality of array chips are formed and an opening 3 facing the array chip.
On the common electrode substrate 1 on which B is formed, an alignment film made of polyimide or the like is applied to the substrate surface, heated and cured, and the surface of the alignment film is generally subjected to an alignment treatment by a rubbing method.

FIG. 6 shows an array chip referred to here. X
A pixel electrode 9 is formed on each of the group of gate signal lines 6 and the group of source signal lines 7 arranged in a Y matrix, the group of thin film transistors 8 electrically connected thereto, and the individual thin film transistors 8. Are arranged in a matrix.

After the alignment treatment, a bead spacer having a constant particle diameter for forming a gap is dispersed and applied to one of the two types of substrates, and a sealing material containing the spacer is applied to the periphery of the array chip. After application, the two types of substrates are aligned and bonded such that the pixel electrode 9 and the opening 3B face each other as shown in FIG. Thereafter, the panel is cut into a single panel, and a liquid crystal material is injected into the gap between the panels to complete the liquid crystal display panel. Here, each thin film transistor 8 on the array chip serves as a driving element, and liquid crystal is formed in a gap between each pixel electrode 9 and the transparent metal film layer 5A (common electrode) on the opposing opening 3B. Can work.

[0006]

However, as shown in FIGS. 4 and 5, in the case where the transparent metal film layer 5A is formed on the entire surface within the effective screen, metal foreign matter is not produced until the step of bonding. When this foreign matter is mixed and adheres to the gate signal line 6 or the source signal line 7 as shown in 10A or 10B in FIG. 7, the opposing transparent metal film layer 5A and each of the signal lines 6 and 7 are short-circuited (electrical). Conduction). Then, a normal signal voltage is not applied to the signal line, and the signal voltage is not supplied to the thin film transistor. As a result, a heavy defect such as a facing short which becomes a gate line defect or a source line defect is caused, and the yield is reduced.

When the height of the metal foreign substances 10A and 10B is slightly smaller than the gap between the substrates, the signal lines are not short-circuited between the transparent metal film layers when the liquid crystal display panel is completed, and are shipped as non-defective products. Is done. However, there is also a problem that when a short circuit occurs due to a temporal change of the gap, a heavy defect defect called a line defect occurs in the market.

An object of the present invention is to solve the conventional problems, and an object of the present invention is to provide a highly reliable liquid crystal display panel by reducing line defects due to metal foreign matter.

[0009]

In order to achieve the above object, a liquid crystal display panel according to the present invention comprises: a first substrate having a transparent metal film layer formed on one principal surface of a transparent substrate; 1
In a liquid crystal display panel in which an array chip having a signal line group in the X direction and the Y direction is formed on a main surface and opposed to each other with a liquid crystal interposed therebetween, and a display area is an effective screen, The transparent metal film layer formed on the first substrate is provided with a plurality of arbitrarily-shaped regions in which no transparent metal film exists within the effective screen.

The region of the transparent metal film layer where the transparent metal film does not exist is an elongated region along the X direction signal line or the Y direction signal line of the array chip.

With such a configuration, even if metal foreign matter adheres to the gate signal line or the source signal line, there is no short circuit because there is no transparent metal film opposed to the foreign matter. The number of defects is drastically reduced, and the yield and market quality can be improved.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a common electrode substrate on which a transparent metal film layer is formed according to an embodiment of the present invention, wherein 3B is an opening of a BM layer, 5A is a transparent metal film layer, and 5B is a transparent metal film. This is a region where the transparent metal film does not exist in the layer 5A.

As shown in FIG. 4, a thickness of about 1000 × 10 ⁻¹⁰ m (or 1000
(Angstrom) BM layer 3A and opening 3B are patterned and then about 2 × 10 ⁻⁶ m (or 2 μm) thick
Red, green and blue color layers 4A, 4B and 4C made of pigment resin
Is formed by a photolithography method. Next, an ITO transparent metal film layer 5A having a thickness of about 1500 × 10 ⁻¹⁰ m (or 1500 angstroms) is formed by photolithography to form a common electrode substrate.

At this time, as shown in FIG. 1, the ITO transparent metal film 5A is formed in a region 5B where the transparent metal film does not exist in the opposing portions of the gate signal line and the source signal line when bonded to the array chip. Is formed so as to be provided as a pattern.

The region where the ITO transparent metal film does not exist may be only an elongated region along the gate signal line and the source signal line as shown in 5C in FIG. 2 and 5D in FIG.

The thicknesses of the BM layer, the color layer, and the ITO transparent metal film layer are not limited to these values depending on required optical characteristics.

The ITO transparent metal film layer may be formed by a method other than the photolithography method.

The pattern-forming portion of the ITO transparent metal film layer may be limited only to the inside of the effective screen to be displayed.

It is also possible to use a transparent resin layer made of an acrylic resin or a polyimide resin after forming the color layer, flattening the layer, and then forming an ITO transparent metal film layer.

The transparent metal film layer is not limited to the ITO metal, but is not limited to the transparent metal depending on the required optical characteristics.

[0021]

As described above, according to the present invention,
Even if metal foreign matter adheres to the gate signal line or the source signal line, the corresponding portion of the transparent metal film layer on the opposed common electrode substrate is a region where the transparent metal film does not substantially exist. A liquid crystal display panel in which line defects and source line defects hardly occur is obtained.

For this reason, it is greatly reduced that a metal foreign matter adheres to a gate signal line or a source signal line and causes a line defect at the time of completion of a liquid crystal display panel to deteriorate the yield as in the related art. Alternatively, even if the gap fluctuates with time after shipment of the liquid crystal display panel, the opposing short-circuit (the above-described line defect failure) is drastically reduced, so that the yield surface and the market quality can be improved, which is extremely effective practically.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a common electrode substrate on which a transparent metal film layer is formed according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of a common electrode substrate on which a transparent metal film layer is formed according to another embodiment of the present invention.

FIG. 3 is a plan view of a main part of a common electrode substrate on which a transparent metal film layer is formed according to still another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a common electrode substrate having a transparent metal film formed on the entire surface in a conventional example.

FIG. 5 is a plan view of a main part of the common electrode substrate of FIG. 4;

FIG. 6 is a plan view of an array substrate in a conventional example.

FIG. 7 is a plan view of a main part of a conventional example in which the common electrode substrate of FIG. 5 and the array substrate of FIG. 6 are bonded together;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 common electrode substrate 2 glass substrate 3A BM (black matrix) layer 3B opening 4 color layer 4A, 4B, 4C red, green, blue color layer 5A transparent metal film layer 5B, 5C, 5D Region where no transparent metal film exists Reference Signs List 6 Gate signal line 7 Source signal line 8 Thin film transistor 9 Pixel electrode 10A, 10B Metallic foreign matter adhering on signal line

Claims (7)

[Claims] 1. A first substrate having a transparent metal film layer formed on one main surface of a transparent substrate, and a first substrate having a transparent metal film layer formed on one main surface of the transparent substrate.
And a second substrate on which an array chip having signal lines in different directions is formed, which are bonded to each other with a liquid crystal interposed therebetween, and formed on the first substrate in a liquid crystal display panel having a display area as an effective screen. A liquid crystal display panel, wherein a plurality of arbitrarily-shaped regions in which no transparent metal film exists are provided in the effective screen of the transparent metal film layer. 2. The liquid crystal display panel according to claim 1, wherein the area of the transparent metal film layer where the transparent metal film does not exist is an elongated area along the X-direction signal line of the array chip. 3. The liquid crystal display panel according to claim 1, wherein the region of the transparent metal film layer where the transparent metal film does not exist is an elongated region along the signal line in the Y direction of the array chip. 4. The liquid crystal display panel according to claim 1, wherein a region of the transparent metal film layer where no transparent metal film exists is formed by a photolithography method. 5. The liquid crystal display panel according to claim 1, wherein the transparent metal film layer is made of ITO. 6. The liquid crystal display panel according to claim 1, wherein the array chip has a thin film transistor. 7. The liquid crystal is TN (Twist Nemat).
2. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is an ic) type liquid crystal.