TFT-type LCD and method of making with pixel electrodes and bus lines having two layers

• US 6,359,666 B1
• Filed: 07/23/1999
• Issued: 03/19/2002
• Est. Priority Date: 03/10/1997
• Status: Expired due to Term

• Current Assignee: Japan Display Central Incorporated (Japan Display Incorporated)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yoshida, Sakae, Hayashi, Hisaaki
• Primary Examiner(s): TON, MINH TOAN T
• Application Number:
  US09/359,318
• Time in Patent Office: 970 Days
• Field of Search: 349/43, 349/143, 349/139, 257/59
• US Class Current: 349/43
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence

Abstract

An active matrix-liquid crystal display device includes an array substrate 100 on which pixel electrodes 151, signal lines 103 with first and second conductive layers 103a and 103b are formed. The first conductive layers 103a and the pixel electrodes 151 are subject to patterning using a same mask in a same optical exposure process. The first conductive layers 103a are wider in width than the second conductive layers 103b. The pixel electrodes 151 and the signal lines 103 maintain constant relative positions on display areas thereby to hardly cause unevenness of resultant images and to enable the device to display better dignity images.

Claims

1. A method of manufacturing an active matrix-type liquid crystal display device, comprising:

making an array substrate;

making a counter substrate provided opposite to said array substrate;

making a liquid crystal layer held between said array and counter substrates;

making switching elements on said array substrate;

making a plurality of electrically conductive lines on said array substrate; and

making a plurality of pixel electrodes on said array substrate;

wherein said conductive lines and said pixel electrodes are connected to said switching elements;

one component selected from the components consisting of said conductive lines and said pixel electrodes is made of first and second layers;

the other component not selected from said components and said first layer are formed by a patterning process using a same mask; and

said first layer is wider in width than said second layer.

2. The active matrix-type liquid crystal display device according to claim 1, wherein electric coupling between said conductive lines and said pixel electrodes is substantially determined by relative positions of said first layers and said conductive lines.

3. A method of manufacturing an active matrix-type liquid crystal display device, comprising:

making an array substrate;

making a counter substrate provided opposite to said array substrate;

making a liquid crystal layer held between said array and counter substrates;

making thin film transistors on said array substrate,

making a plurality of electrically conductive signal lines on said array substrate,

making a plurality of electrically conductive scanning lines on said array substrate,

making a plurality of pixel electrodes on said array substrate,

wherein said signal and scanning lines and said pixel electrodes are connected to said thin film transistors,

said signal and scanning lines are disposed to cross each other, and

said signal lines are made of first and second layers, said first layers are wider in width than said second layers, and said second layers are formed within said first layers and

said first layers and said pixel electrodes are formed by a patterning process using a same mask.

4. The method of manufacturing an active matrix-type liquid crystal display device according to claim 3, wherein said first layers cover one edge of said second layers and define substantially a predetermined distance from said pixel electrodes.

5. A method of manufacturing an active matrix-type liquid crystal display device, comprising:

providing an array substrate;

providing a counter substrate provided opposite to said array substrate;

providing a liquid crystal layer held between said array and counter substrates;

forming thin film transistors on said array substrate,

forming a plurality of electrically conductive signal lines on said array substrate,

forming, a plurality of electrically conductive scanning lines on said array substrate,

forming a plurality of pixel electrodes on said array substrate,

wherein said signal and scanning lines and said pixel electrodes are connected to said thin film transistors, said signal and scanning lines are disposed to cross each other, and said signal lines are made of first and second layers, patterning said first layers and said pixel electrodes by using the same mask, and

said first layers are wider in width than said second layers, and said second layers are formed within said first layers.

6. A method of manufacturing an active matrix-type liquid crystal display device, comprising the steps of making:

an array substrate;

a counter substrate provided opposite to said array substrate;

a liquid crystal layer held between said array and counter substrates;

thin film transistors,

a plurality of electrically conductive signal lines connected to said thin film transistors,

a plurality of electrically conductive scanning lines connected to said thin film transistors, and

a plurality of pixel electrodes connected to said thin film transistors,

wherein said signal and scanning lines and said pixel electrodes are formed on said array substrate,

said signal and scanning lines are disposed to cross each other,

said pixel electrodes are made of first and second layers, and

said first layers and said signal lines are formed by a patterning process using a same mask.

7. The method of manufacturing an active matrix-type liquid crystal display device according to claim 6, wherein said first layers cover one edge of said second layers and define substantially a predetermined distance from said pixel electrodes.

8. The method of manufacturing an active matrix-type liquid crystal display device according to claim 6, wherein said first layers are wider in width than said second layers, said second layers are formed within said first layers.

9. A method of manufacturing an active matrix-type liquid crystal display device including an array substrate,

a counter substrate provided opposite to said array substrate, and

a liquid crystal layer held between said array and counter substrates,

said array substrate having

switching elements,

a plurality of electrically conductive lines connected to said switching elements, and

a plurality of pixel electrodes connected to said switching elements, comprising:

preparing a plurality of regions which are sequentially processed to make said array substrate;

selecting one component in each of said regions from the components consisting of said conductive lines and said pixel electrodes;

forming said one component with first and second layers; and

patterning the other component not selected from said components and said first layers through a same mask;

wherein said patterning forms said first layers wider in width than said second layers.

10. The method of manufacturing an active matrix-type liquid crystal display device according to claim 9, wherein said patterning step forms said first layers to cover one edge of said second layers and to define substantially a predetermined distance from said other component.

11. A method of manufacturing an active matrix-type liquid crystal display device including an array substrate, a counter substrate provided opposite to said array substrate, and a liquid crystal layer held between said array and counter substrates;

said array substrate having switching elements, a plurality of electrically conductive lines connected to said switching elements, and a plurality of pixel electrodes connected to said switching elements, the method comprising;

preparing a plurality of regions which are sequentially processed to make said array substrate;

selecting one component in each of said regions from the components consisting of said conductive lines and said pixel electrodes;

forming said one component with first and second layers; and

patterning the other component not selected from said components and said first layers through a same mask;

wherein said patterning forms said first layers wider in width than said second layers to receive said second layers.