Display substrate, display device and method of manufacturing the same

• US 7,943,932 B2
• Filed: 11/02/2007
• Issued: 05/17/2011
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Park, Yong In, Kim, Sang Soo, Paek, Seung Han
• Primary Examiner(s): Fahmy; Wael M
• Assistant Examiner(s): ARMAND, MARC ANTHONY
• Application Number:
  US11/979,459
• Publication Number:
  US 20080185588A1
• Time in Patent Office: 1,292 Days
• Field of Search: 257/59, 257/E29.003, 257/E21.7, 257/252, 257/254, 257/257, 257/258, 257/253, 257/E33.059, 257/E33.001, 257/E33.008, 438/151, 438/30
• US Class Current: 257/59
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence

Abstract

A flexible display substrate includes: a thin film transistor on the flexible substrate, the thin film transistor including a gate electrode, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer; a first stress absorbing layer below the thin film transistor; a first protection layer on the first stress absorbing layer; a second stress absorbing layer on the thin film transistor; a second protection layer on the second stress absorbing layer; and a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode.

Claims

1. A flexible display substrate comprising:

a thin film transistor on the flexible substrate, the thin film transistor including a gate electrode extending from a gate line, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer;

a storage capacitor on the flexible substrate, the storage capacitor including the gate line, the gate insulating layer and a storage capacitor electrode covering the gate line;

a first stress absorbing layer below the thin film transistor and the storage capacitor;

a first protection layer on the first stress absorbing layer;

a second stress absorbing layer on the thin film transistor and the storage capacitor;

a second protection layer on the second stress absorbing layer;

a third stress absorbing layer on the pixel electrode;

a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode via a first contact hole in the second stress absorbing layer and the second protection layer and with the storage capacitor electrode via a second contact hole in the second stress absorbing and the second protection layer; and

a third protection layer between the second stress absorbing layer and the thin film transistor.

2. The flexible display substrate of claim 1,

wherein the first stress absorbing layer includes an organic layer;

wherein the first protection layer includes an inorganic layer;

wherein the second stress absorbing layer includes an organic layer;

wherein the second protection layer includes an inorganic layer; and

wherein the third protection layer includes an inorganic layer.

3. The flexible display substrate of claim 1, wherein the third stress absorbing layer includes an organic layer.

4. A method of manufacturing a flexible display substrate comprising:

forming a first stress absorbing layer on the flexible substrate;

forming a first protection layer on the first stress absorbing layer;

forming a thin film transistor on the first protection layer, the thin film transistor including a gate electrode extending from a gate line, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer;

forming a storage capacitor on the flexible substrate, the storage capacitor including the gate line, the gate insulating layer and a storage capacitor electrode covering the gate line;

forming a second stress absorbing layer on the thin film transistor and the storage capacitor;

forming a second protection layer on the second stress absorbing layer;

forming a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode via a first contact hole in the second stress absorbing layer and the second protection layer and with the storage capacitor electrode via a second contact hole in the second stress absorbing and the second protection layer; and

a third protection layer below the second stress absorbing layer and on the thin film transistor and the storage capacitor.

5. The method of claim 4,

wherein the first stress absorbing layer includes an organic layer;

wherein the first protection layer includes an inorganic layer;

wherein the second stress absorbing layer includes an organic layer;

wherein the second protection layer includes an inorganic layer; and

wherein the third protection layer includes an inorganic layer.

6. The flexible display substrate of claim 4, further comprising a third stress absorbing layer on the pixel electrode.

7. The flexible display substrate of claim 6 wherein the third stress absorbing layer includes an organic layer.

8. A method of manufacturing an electrophoretic ink flexible display device comprising:

forming a first stress absorbing layer on a flexible substrate;

forming a first protection layer on the first stress absorbing layer;

forming a thin film transistor on the first protection layer, the thin film transistor including a gate electrode extending from a gate line, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer;

forming a storage capacitor on the flexible substrate, the storage capacitor including the gate line, the gate insulating layer and a storage capacitor electrode covering the gate line;

forming a second stress absorbing layer on the thin film transistor and the storage capacitor;

forming a second protection layer on the second stress absorbing layer;

forming a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode via a first contact hole in the second stress absorbing layer and the second protection layer and with the storage capacitor electrode via a second contact hole in the second stress absorbing and the second protection layer;

forming an electrophoretic ink film on the flexible substrate; and

a third protection layer below the second stress absorbing layer and on the thin film transistor and the storage capacitor.

9. The method of claim 8,

wherein the first stress absorbing layer includes an organic layer;

wherein the first protection layer includes an inorganic layer;

wherein the second stress absorbing layer includes an organic layer;

wherein the second protection layer includes an inorganic layer; and

wherein the third protection layer includes an inorganic layer.

10. A method of manufacturing a flexible liquid crystal display device comprising:

forming a first stress absorbing layer on a first flexible substrate;

forming a first protection layer on the first stress absorbing layer;

forming a thin film transistor on the first protection layer, the thin film transistor including a gate electrode extending from a gate line, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer;

forming a storage capacitor on the flexible substrate, the storage capacitor including the gate line, the gate insulating layer and a storage capacitor electrode covering the gate line;

forming a second stress absorbing layer on the thin film transistor;

forming a second protection layer on the second stress absorbing layer;

forming a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode via a first contact hole in the second stress absorbing layer and the second protection layer and with the storage capacitor electrode via a second contact hole in the second stress absorbing and the second protection layer;

forming a second flexible substrate;

forming a liquid crystal layer between the first and second flexible substrates, and

a third protection layer below the second stress absorbing layer and on the thin film transistor and the storage capacitor.

11. The method of claim 10, further comprising:

forming a black matrix on the second flexible substrate;

forming a color filter layer on the black matrix;

forming an overcoat layer on the color filter layer; and

forming a common electrode on the overcoat layer.

12. The method of claim 10,

wherein the first stress absorbing layer includes an organic layer;

wherein the first protection layer includes an inorganic layer;

wherein the second stress absorbing layer includes an organic layer;

wherein the second protection layer includes an inorganic layer; and

wherein the third protection layer includes an inorganic layer.

13. A flexible display substrate, comprising:

a thin film transistor on the flexible substrate, the thin film transistor including a gate electrode extending from a gate line, a gate insulating layer insulating the gate electrode, a channel layer on the gate insulating layer, a source electrode connected with the channel layer, and a drain electrode connected with the channel layer;

a storage capacitor on the flexible substrate, the storage capacitor including the gate line, the gate insulating layer and a storage capacitor electrode covering the gate line;

a first stress absorbing layer below the thin film transistor and the storage capacitor;

a first protection layer on the first stress absorbing layer;

a second stress absorbing layer on the thin film transistor and the storage capacitor;

a second protection layer on the second stress absorbing layer; and

a pixel electrode on the second protection layer, the pixel electrode being connected with the drain electrode via a first contact hole in the second stress absorbing layer and the second protection layer and with the storage capacitor electrode via a second contact hole in the second stress absorbing and the second protection layer; and

a third protection layer below the second stress absorbing layer and on the thin film transistor and the storage capacitor.

14. The flexible display substrate of claim 13, wherein the third protection layer contacts an amorphous silicon pattern of the channel layer exposed between the source electrode and the drain electrode.