Flexible thin film transistor substrate and flexible organic light emitting display device

Patent metadata

Field	Value
Publication number	US-2016118451-A1
Application number	US-201514877486-A
Country	US
Kind code	A1
Filing date	Oct 7, 2015
Priority date	Oct 22, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

Provided are a flexible thin film transistor substrate and a flexible organic light emitting display device. The flexible thin film transistor substrate includes: a flexible substrate including at least one thin film transistor (TFT) area and having flexibility, an active layer disposed in the TFT area on the flexible substrate, a gate insulation layer disposed on the active layer, a gate electrode overlapping with the active layer on the gate insulation layer, an insulating interlayer disposed on the gate electrode, and a source electrode and a drain electrode disposed on the insulating interlayer and connected with the active layer, respectively. The gate insulation layer or the insulating interlayer includes at least one hole pattern configured to reduce bending stress.

First claim

What is claimed is:

1 . A flexible thin film transistor substrate comprising:
a flexible substrate including at least one thin film transistor (TFT) area and having flexibility; an active layer disposed in the TFT area on the flexible substrate; a gate insulation layer disposed on the active layer; a gate electrode overlapping with the active layer on the gate insulation layer; an insulating interlayer disposed on the gate electrode; and a source electrode and a drain electrode disposed on the insulating interlayer and connected with the active layer, respectively, wherein the gate insulation layer or the insulating interlayer includes at least one hole pattern disposed outside the TFT area, and the hole pattern configured to reduce bending stress generated by bending the flexible substrate.

2 . The flexible thin film transistor substrate according to claim 1 , wherein the hole pattern is extended in a direction parallel to a folding line in which the flexible substrate is folded.

3 . The flexible thin film transistor substrate according to claim 1 , wherein the hole pattern surrounds the TFT area.

4 . The flexible thin film transistor substrate according to claim 1 , wherein the hole pattern is disposed in both the gate insulation layer and the insulating interlayer, and the hole pattern of the insulating interlayer corresponds to the hole pattern of the gate insulation layer.

5 . The flexible thin film transistor substrate according to claim 4 , further comprising:
a passivation layer covering the insulating interlayer, the source electrode, and the drain electrode.

6 . The flexible thin film transistor substrate according to claim 5 , wherein the passivation layer includes a hole pattern corresponding to the hole pattern of the insulating interlayer.

7 . The flexible thin film transistor substrate according to claim 6 , wherein the gate insulation layer, the insulating interlayer, and the passivation layer are inorganic insulation layers.

8 . A flexible organic light emitting display device comprising:
a flexible substrate having a pixel area including a plurality of sub pixel areas; a planarization layer disposed on the flexible substrate; a first electrode disposed on the planarization layer; a bank layer disposed to cover an edge of the first electrode; an organic light emission layer disposed on the first electrode; and a second electrode disposed on the organic light emission layer, wherein a hole pattern is formed in at least one of the planarization layer and the bank layer, and at least one of the planarization layer and the bank layer is separately disposed on the flexible substrate by the hole pattern.

9 . The flexible organic light emitting display device according to claim 8 , wherein only the planarization layer of the planarization layer and the bank layer is separately disposed on the flexible substrate.

10 . The flexible organic light emitting display device according to claim 9 , wherein the bank layer fills the hole pattern.

11 . The flexible organic light emitting display device according to claim 8 , wherein both the planarization layer and the bank layer are separately disposed on the flexible substrate.

12 . The flexible organic light emitting display device according to claim 8 , wherein only the bank layer of the planarization layer and the bank layer is separately disposed on the flexible substrate.

13 . The flexible organic light emitting display device according to claim 8 , wherein a minimum width of the hole pattern is 1 μm to 50 μm.

14 . The flexible organic light emitting display device according to claim 8 , wherein the planarization layer is made of photosensitive photo acryl or photosensitive polyimide.

15 . The flexible organic light emitting display device according to claim 8 , wherein the bank layer is made of polyimide, photo acryl, or benzocyclobutene (BCB).

16 . The flexible organic light emitting display device according to claim 8 , wherein the hole pattern is extended to form a mesh pattern.

17 . A flexible organic light emitting display device comprising:
a flexible substrate on which a thin film transistor is disposed; an inorganic insulation layer disposed on the flexible substrate; an organic insulation layer disposed on the inorganic insulation layer; and an organic light emitting element disposed on the organic insulation layer and electrically connected with the thin film transistor, wherein at least one of the organic insulation layer and the inorganic insulation layer includes a hole pattern, and the hole pattern minimizes probability of generation of cracks due to bending of the flexible substrate and suppresses propagation of the cracks.

18 . The flexible organic light emitting display device according to claim 17 , wherein the thin film transistor includes:
an active layer; a gate electrode separated from the active layer and overlapping with the active layer; and a source electrode and a drain electrode electrically connected with the active layer, and wherein the inorganic insulation layer includes: a gate insulation layer insulating the active layer from the gate electrode of the thin film transistor; an insulating interlayer insulating the source electrode and the drain electrode from the gate electrode, respectively; and a passivation layer covering the thin film transistor, and the hole pattern is disposed on at least one of the gate insulation layer, the insulating interlayer, and the passivation layer.

19 . The flexible organic light emitting display device according to claim 18 , wherein the thin film transistor is disposed in a circuit area of the flexible substrate,
the organic light emitting element is disposed in a display area of the flexible substrate, and the hole pattern is disposed on a boundary where the display area and the circuit area contact each other.

20 . The flexible organic light emitting display device according to claim 19 , further comprising:
a gate line disposed in the circuit area and connected with the gate electrode of the thin film transistor, wherein the hole pattern is spaced apart from the gate line and extended in parallel with the gate line.

21 . The flexible organic light emitting display device according to claim 19 , further comprising:
a data line disposed in the circuit area and connected with the source electrode or the drain electrode of the thin film transistor, wherein the hole pattern is spaced apart from the data line and extended in parallel with the data line.

22 . The flexible organic light emitting display device according to claim 17 , wherein the organic light emitting element includes:
a first electrode connected with the thin film transistor; an organic light emission layer disposed on the first electrode; and a second electrode disposed on the organic light emission layer, wherein the organic insulation layer includes: a planarization layer covering the thin film transistor and planarizing an upper surface of the flexible substrate; and a bank layer disposed to cover an edge of the first electrode, and wherein the hole pattern is disposed on at least one of the planarization layer and bank layer.

23 . The flexible organic light emitting display device according to claim 22 , wherein the flexible substrate has a sub pixel area disposed with the organic light emitting element and a pixel area including the sub pixel area, and
the

Assignees

• Lg Display Co Ltd

Inventors

• Youn Sangcheon
• Choi Nackbong
• Cho Yoondong

Classifications

• H10D30/6736

  characterised by the shape of gate insulators · CPC title

• H10D86/451

  characterised by the compositions or shapes of the interlayer dielectrics · CPC title

• H10D86/411

  characterised by materials, geometry or structure of the substrates · CPC title

• H10D86/60

  wherein the TFTs are in active matrices · CPC title

• H10D30/6758

  characterised by the insulating substrates · CPC title