Liquid crystal display device and its manufacturing method

• US 20020118318A1
• Filed: 02/25/2002
• Published: 08/29/2002
• Est. Priority Date: 02/23/2001
• Status: Active Grant

• Current Assignee: Beihai HKC Optoelectronics Technology Company Limited
• Original Assignee: NEC Corporation
• Inventors: Sakamoto, Michiaki, Okamoto, Mamoru, Kuroha, Shouichi, Hidehira, Masanobu
• Granted Patent: US 7,098,970 B2
• Time in Patent Office: Days
• US Class Current: 349/43
• CPC Class Codes: G02F 1/13373 Disclination line; Reverse tilt
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

In an active matrix type liquid crystal display device comprising a TFT having gate lines and data lines formed in a matrix manner and being connected to a source line, a contact hole for connecting the source line with a pixel electrode is formed in a position overlapping a disclination line. The contact hole is formed in a position overlapping a capacitance portion of the gate line. The gate line and the source line are provided to oppose to each other, and electrostatic capacitance is stored therebetween.

Claims

1. A liquid crystal display device comprising:

a pair of substrates;

a liquid crystal sealed between said pair of substrates;

a plurality of data lines and a plurality of scanning lines, being arranged on one surface of one of said pair of substrates and crossing each other;

a switching element having one end of a current path connected to the corresponding data line and a control end connected to the corresponding scanning line;

a wiring connected to the other end of the current path of said switching element;

an insulating layer, being formed on said wiring and having a contact hole through which an end portion of said wiring is exposed;

a pixel electrode, being formed on said insulating layer and electrically connected to the end portion of said wiring through the contact hole; and

an alignment film, being formed on said pixel electrode and in contact with said liquid crystal,

wherein said contact hole is formed at a position overlapping a region where disclination occurs.

2. The liquid crystal display device according to claim 1, wherein said insulating layer is formed of a plurality of laminated insulating films,

the insulating films have openings individually which form said contact hole in a tapered shape as a whole.

3. The liquid crystal display device according to claim 1, wherein said insulting films includes a passivation film formed on the switching element, a color layer formed on said passivation film, and a flattening film formed on said passivation film and color layer,

said contact hole includes openings formed in the passivation film, the color layer, and the flattening film, respectively, and the openings being formed in a tapered shape as a whole.

4. The liquid crystal display device according to claim 1, wherein said wiring is made of a light shielding material, and

said contact hole and at least a part of said region where disclination occurs are shielded by said wiring.

5. The liquid crystal display device according to claim 1, wherein the scanning lines and the data lines bounds a plurality of pixels each having said contact hole,

said contact hole in the pixel is provided at a downstream in a rubbing direction with respect to the switching element of other pixel adjacent to the pixel.

6. The liquid crystal display device according to claim 1, wherein said scanning line has a projecting portion overlapping said contact hole and/or said region where disclination occurs and shielding light.

7. The liquid crystal display device according to claim 4, further comprising a black matrix overlapping said data lines, wherein said black matrix has a wide portion overlapping a region in the pixel between said data line and the projecting portion.

8. The liquid crystal display device according to claim 4, wherein said projecting portion forms electrostatic capacitance between the wiring.

9. A liquid crystal display device manufacturing method, the liquid crystal display device comprising a thin film transistor, a wiring connected to said thin film transistor, a pixel electrode electrically connected to said wiring, and an alignment film formed on said pixel electrode, comprising steps of:

forming an insulating layer overlying the thin film transistor and the wiring;

forming a contact hole in the insulating layer through which an end portion of said wiring is exposed;

forming the pixel electrode on the insulating layer connected electrically with the wiring through the contact hole; and

forming the alignment film on the pixel electrode,

wherein the step of forming the contact hole comprising a step of forming the contact hole in a position overlapping a region where disclination occurs.

10. A liquid crystal display device manufacturing method according to claim 9, the insulating layer including a plurality of laminated insulating films,

the step of forming the contact hole comprising a step of forming openings in the plurality of the insulating films respectively.

11. A liquid crystal display device manufacturing method according to claim 9, the insulating layer including a passivation film formed on the switching element, a color layer formed on said passivation film, and a flattening film formed on said passivation film and color layer,

the step of forming the contact hole comprising a step of forming openings in the passivation film, the color layer, and the flattening film, respectively, thereby forming the contact hole in a tapered shape as a whole.