FLEXIBLE DISPLAY AND METHOD OF MANUFACTURING THE SAME

• US 20170123543A1
• Filed: 10/24/2016
• Published: 05/04/2017
• Est. Priority Date: 10/30/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: CHOI, Nack-Bong, KIM, Mi-Seong
• Granted Patent: US 10,824,256 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens
• CPC Class Codes: H10K 77/111 Flexible substrates

Abstract

A flexible display device includes a touch electrode array including a buffer layer with a through hole in the buffer layer, a touch pad metal electrode in the through hole, a plurality of touch patterns on the buffer layer, and a flexible printed circuit contacting the touch pad electrode. Optionally, the flexible printed circuit can also contact a thin-film transistor pad on an organic light emitting array substrate laminated to the touch electrode array.

Claims

1. A flexible display device comprising:

an organic light emitting display unit;

an adhesive layer on the organic light emitting display unit;

a touch electrode array on the adhesive layer;

a buffer layer on the touch electrode array, the buffer layer including a through hole in the buffer layer;

a touch pad electrode in the through hole, exposed on a first surface of the buffer layer; and

a flexible printed circuit contacting the touch pad electrode.

2. The flexible display according to claim 1, wherein the flexible printed circuit flatly contacts on a surface of the touch pad electrode and the first surface of the buffer layer.

3. The flexible display device of claim 1, further comprising a barrier layer between the adhesive layer and the touch electrode array.

4. The flexible display device of claim 1, wherein the touch electrode array further comprises:

a metal mesh and routing wires on a second surface of the buffer layer;

a plurality of touch patterns on the buffer layer and contacting the metal mesh; and

an interlayer dielectric over the plurality of touch patterns and exposing a portion of each of the touch patterns;

a bridge pattern on the interlayer dielectric; and

a passivation layer covering the bridge pattern.

5. The flexible display according to claim 4, wherein the touch pad electrode is made of the same material as the metal mesh layer.

6. The flexible display device of claim 1, wherein the organic light emitting display unit comprises a thin film transistor array, an organic light emitting diode array connected to the thin film transistor array, and an encapsulation layer to cover the organic light emitting diode array on a base film.

7. The flexible display device of claim 6, wherein the thin film transistor array evenly protrudes from the touch electrode array, the protruding thin film transistor array has a thin film transistor pad electrode, and the flexible printed circuit is connected to the thin film transistor pad electrode.

8. The flexible display device of claim 6, further comprising a back cover film on an outer surface of the base film.

9. The flexible display according to claim 1, wherein the buffer layer is an organic layer having a thickness of 0.1 μ

m to 8 μ

m.

18. The method according to claim 9, wherein the step of connecting the flexible printed circuit to the touch pad electrode comprises connecting the flexible printed circuit to the touch pad electrode such that the flexible printed circuit flatly contacts on a surface of the touch pad electrode and the first surface of the buffer layer.

19. The method of claim 8, wherein the step of providing an organic light emitting display unit comprises forming a thin film transistor array and a thin-film transistor pad on the base film, forming an organic light emitting diode array connected to the thin film transistor array, and forming an encapsulation layer to cover the organic light emitting diode array.

20. The method of claim 19, further comprising contacting to the flexible printed circuit on the base film.

10. A flexible display device including a touch electrode array, the touch electrode array comprising:

a buffer layer including a through hole in the buffer layer;

a touch pad metal electrode in the through hole;

a metal mesh and routing wires on the buffer layer;

a transparent electrode material on the touch pad metal electrode forming a multi-layer touch pad electrode;

a plurality of touch patterns on the buffer layer and contacting the metal mesh; and

a flexible printed circuit contacting the multi-layer touch pad electrode.

11. A method of manufacturing a flexible display device, comprising:

providing a glass substrate;

forming a buffer layer on the glass substrate;

patterning a through hole in the buffer layer;

forming a touch pad electrode in the through hole;

forming a touch electrode array on the buffer layer;

providing an organic light emitting display unit;

laminating the organic light emitting display unit and the touch electrode array in a state in which an adhesive layer is disposed therebetween;

removing the glass substrate to expose the touch pad electrode on a first surface of the buffer layer; and

connecting a flexible printed circuit to the exposed touch pad electrode.

12. The method according to claim 11, further comprising forming a barrier layer on a surface of the touch electrode array.

13. The method according to claim 11, further comprising forming a sacrificial layer between the glass substrate and the buffer layer.

14. The method according to claim 13, wherein the step of forming the sacrificial layer comprises partially removing a portion of a peripheral area of the sacrificial layer that does not overlap the touch electrode array and the touch pad electrode and forming a metal shielding pattern in the removed area of the sacrificial layer.

15. The method according to claim 13, wherein the sacrificial layer is also removed during the step of removing the glass substrate.

16. The method according to claim 14, wherein the metal shielding pattern is also removed during the step of removing the glass substrate.

17. The method according to claim 11, wherein the step of forming the touch electrode array and the touch pad electrode comprises:

forming a metal mesh layer on the buffer layer and forming a touch pad electrode metal layer on the same layer;

forming a plurality of touch patterns connected to the metal mesh layer and forming a transparent electrode metal layer on the touch pad electrode metal layer to form a touch pad electrode comprising the touch pad electrode metal layer and the transparent electrode metal layer disposed in a stacked state;

forming an interlayer dielectric to cover the touch patterns while partially exposing the touch patterns on the metal mesh layer;

forming a bridge pattern on the interlayer dielectric between ones of the touch patterns adjacent to each other in a first direction; and

forming a passivation film to cover the bridge pattern.