Liquid crystal display device and method for fabricating the same

• US 20090323007A1
• Filed: 12/30/2008
• Published: 12/31/2009
• Est. Priority Date: 06/27/2008
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Shim, Jae-Hoon
• Granted Patent: US 8,259,277 B2
• Time in Patent Office: Days
• US Class Current: 349/155
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 2201/503 Arrangements improving the resistance to shock

Abstract

A liquid crystal display (LCD) device includes a first substrate having a plurality of pixels defined by crossing gate lines and data lines; a second substrate facing the first substrate; a thin film transistor formed at each crossing between the gate line and the data line on each pixel and having a gate electrode connected to the gate line and a source electrode connected to the data line; a pixel electrode formed at each pixel and connected to a drain electrode of the thin film transistor; a plurality of column spacers formed between the first and second substrates and configured to maintain a gap therebetween; and a protrusion formed on the first substrate and overlapped with one or more of the plurality of column spacers, wherein the protrusion includes a first layer made of the same material as an active layer of the thin film transistor and formed on the same layer as the active layer; a second layer made of the same material as the source and drain electrodes of the thin film transistor and formed on the same layer as the electrodes; and a third layer made of the same material as the pixel electrode and formed on the same layer as the pixel electrode.

Claims

1. A liquid crystal display (LCD) device, comprising:

a first substrate having a plurality of pixels defined by crossing gate lines and data lines;

a second substrate facing the first substrate;

a thin film transistor formed at each crossing between the gate line and the data line on each pixel and having a gate electrode connected to the gate line and a source electrode connected to the data line;

a pixel electrode formed at each pixel and connected to a drain electrode of the thin film transistor;

a plurality of column spacers formed between the first and second substrates and configured to maintain a gap therebetween; and

a protrusion formed on the first substrate and overlapped with one or more of the plurality of column spacers, wherein the protrusion includes;

a first layer made of the same material as an active layer of the thin film transistor and formed on the same layer as the active layer,

a second layer made of the same material as the source and drain electrodes of the thin film transistor and formed on the same layer as the electrodes, and

a third layer made of the same material as the pixel electrode and formed on the same layer as the pixel electrode.

2. The device of claim 1, wherein the column spacers are formed on the second substrate.

3. The device of claim 1, wherein the protrusion is disposed to press upwardly the column spacer.

4. The device of claim 1, wherein the protrusion is formed on the gate line of the first substrate.

5. The device of claim 1, wherein the protrusion is less distributed at a central portion of the first substrate than at an edge of the first substrate.

6. A method for fabricating a liquid crystal display (LCD) device, comprising:

preparing a first substrate having a plurality of pixels defined thereon;

forming a gate electrode of a thin film transistor on each pixel of the first substrate by using a first mask;

forming a gate insulating layer on the first substrate;

forming active layer and source and drain electrodes of the thin film transistor and first and second layers of a protrusion on the gate insulating layer by using a second mask;

forming a protection film covered on the source and drain electrodes of the thin film transistor and the second layer of the protrusion, and forming a contact hole for exposing part of the drain electrode on the protection film by using a third mask;

forming a pixel electrode coming in contact with the drain electrode through the contact hole and a third layer of the protrusion by using a fourth mask;

preparing a second substrate;

forming a plurality of column spacers on the second substrate, wherein part of the plurality of column spacers is overlapped with the protrusion on the first substrate; and

bonding the first substrate to the second substrate such that the protrusion is overlapped with part of the plurality of column spacers.

7. The method of claim 6, wherein during the step of forming the gate electrode of the thin film transistor using the first mask, the gate line is also formed,

wherein the protrusion is formed at an area overlapped with the gate line.

8. The method of claim 6, wherein the protrusion is less distributed at a central portion of the first substrate than at an edge of the first substrate.

9. The method of claim 6, wherein at the step of bonding the first substrate to the second substrate, the protrusion on the first substrate is disposed to press the column spacer on the second substrate by a certain pressure.