Flexible oled display with chiplets

• US 7,816,856 B2
• Filed: 02/25/2009
• Issued: 10/19/2010
• Est. Priority Date: 02/25/2009
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Hamer, John W., Cok, Ronald S.
• Primary Examiner(s): Patel; Ashok
• Application Number:
  US12/392,524
• Publication Number:
  US 20100213819A1
• Time in Patent Office: 601 Days
• Field of Search: None
• US Class Current: 313/503
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/129 Chiplets
• CPC Class Codes: H10K 59/8722 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

A flexible emissive display device having an adhesion layer thinner than the device substrate; a plurality of chiplets adhered to the adhesion layer wherein at least a portion of the adhesion layer extends above a portion of the chiplets; an OLED formed over the adhesion layer and wherein the OLED is thinner than the adhesion layer; a cover thicker than the adhesion layer located over the OLED and adhered to the device substrate; and wherein the chiplets and OLED are at or near the neutral stress plane of the device and the bending radius of the device is less than 2 cm.

Claims

1. A flexible emissive display device, comprising:

a) a substrate having a display area;

b) an adhesion layer thinner than the substrate formed on the substrate surface;

c) a plurality of chiplets having a thickness greater than 2 microns and less than 200 microns adhered to the adhesion layer, each chiplet having at least one connection pad, the plurality of chiplets distributed within the display area, and wherein at least a portion of the adhesion layer extends above a portion of the chiplets;

d) a plurality of bottom electrodes formed over the adhesion layer in the display area, each bottom electrode electrically connected to a connection pad of one chiplet, whereby the chiplets provide current to each of the bottom electrodes;

e) at least one layer of light-emitting material formed over the bottom electrode;

f) a top electrode formed over the at least one layer of light-emitting material, wherein the bottom electrodes, the at least one layer of material, and the top electrode together are thinner than the adhesion layer;

g) a cover thicker than the adhesion layer located over the top electrode and adhered to the substrate; and

h) wherein the chiplets, bottom electrodes, at least one layer of light-emitting material, and top electrodes are at or near the neutral stress plane of the structure formed by the layers a-g and the bending radius of the flexible emissive display device is less than 2 cm.

2. The flexible emissive display device of claim 1, wherein the substrate and the cover comprise the same material.

3. The flexible emissive display device of claim 1, wherein the substrate and the cover have the same thickness.

4. The flexible emissive display device of claim 1, wherein the substrate and the cover comprise different material.

5. The flexible emissive display device of claim 4, wherein the substrate and the cover have a different thickness.

6. The flexible emissive display device of claim 1, further comprising a buffer layer located between the top electrode and the cover.

7. The flexible emissive display device of claim 6, wherein the buffer layer and the adhesion layer comprise the same material.

8. The flexible emissive display device of claim 6, wherein the buffer layer and the adhesion layer have the same thickness.

9. The flexible emissive display device of claim 6, wherein the buffer layer is less flexible than the cover.

10. The flexible emissive display device of claim 6, wherein the buffer layer and the adhesion layer comprise different material.

11. The flexible emissive display device of claim 10, wherein the buffer layer and the adhesion layer have a different thickness.

12. The flexible emissive display device of claim 6, wherein the buffer layer has a thickness between 2 and 50 microns.

13. The flexible emissive display device of claim 1, wherein the adhesion layer is less flexible than the substrate.

14. The flexible emissive display device of claim 1, further comprising an encapsulation layer formed over or within the adhesion layer.

15. The flexible emissive display device of claim 1, further comprising an encapsulation layer formed over the chiplets and the adhesion layer.

16. The flexible emissive display device of claim 1, further comprising an encapsulation layer formed over a wire connected to the connection pads.

17. The flexible emissive display device of claim 1, wherein the adhesion layer has thickness of 2-50 microns.

18. The flexible emissive display device of claim 1, wherein the substrate has a thickness of 50-500 microns or wherein the cover has a thickness of 50-500 microns.

19. The flexible emissive display device of claim 1, wherein the neutral stress plane is located where the top electrode and the one or more layers of material meet.

20. The flexible emissive display device of claim 1, further comprising a wiring layer formed over the adhesion layer.