Flexible organic electroluminescent device and method for fabricating the same

• US 10,541,288 B2
• Filed: 12/20/2017
• Issued: 01/21/2020
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Su Ho, Kim, Sang Bae, Jeon, Jun Tae, Lee, Yong Sam
• Primary Examiner(s): Sengdara, Vongsavanh
• Application Number:
  US15/848,549
• Publication Number:
  US 20180130862A1
• Time in Patent Office: 762 Days
• Field of Search: 257 40, 438 23
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/868 Arrangements for polarized light emission H10K50/86 takes precedence
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/8722 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/873 Encapsulations
• CPC Class Codes: H10K 59/8793 Arrangements for polarized light emission H10K59/8791 takes precedence
• CPC Class Codes: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

Provided is a flexible organic electroluminescent device and a method for fabricating the same. In the flexible electroluminescent device, line hole patterns are formed on surfaces of a plurality of inorganic layers positioned in a pad region in which a flexible printed circuit board is connected to prevent a path of cracks caused by repeated bending and spreading of the organic electroluminescent device from spreading to the interior of the device.

Claims

1. A method for fabricating a flexible organic electroluminescent device, the method comprising:

providing a substrate in which a display region including a plurality of pixel regions and a non-display region including a pad region outside the display region are defined, the pad region to which a flexible printed circuit board (FPCB) is connected and having a shorter side and a longer side;

forming a plurality of thin film transistors (TFTs) together with a gate insulating layer and an interlayer insulating layer on the substrate, the interlayer insulating layer being on the gate insulating layer;

forming a first passivation layer on the interlayer insulating layer on which the TFTs is formed;

forming at least one line hole pattern in one or more of the interlayer insulating layer and the first passivation layer in the pad region of the non-display region in a direction substantially parallel with the longer side of the pad region to which the FPCB is connected;

forming a planarization layer on the first passivation layer;

forming a first electrode connected to a drain electrode of each TFT in each pixel region on the planarization layer;

forming a pixel defining layer around each pixel region on the planarization layer on which the first electrode is formed;

forming an organic light emitting layer in each pixel region above the first electrode;

forming a second electrode on the entire surface of the display region on which the organic light emitting layer is formed; and

forming a second passivation layer on the non-display region and the display region on which the second electrode is formed,

wherein an upper insulating layer disposed on the at least one line hole pattern and filling the at least one line hole pattern contacts with a lower insulating layer disposed under the at least one line hole pattern through the at least one line hole pattern, and

wherein the upper insulating layer is any one of the first passivation layer and the second passivation layer and the lower insulating layer is any one of the gate insulating layer and the interlayer insulating layer.

2. The method of claim 1, further comprising:

forming an organic layer on the second passivation layer in the display region;

forming an third passivation layer on the first passivation layer including the organic layer;

forming a polarization plate together with a barrier film on the third passivation layer;

delaminating the substrate; and

laminating a back plate to the portion from which the substrate was delaminated,

after the forming of the second electrode on the entire surface of the display region including the organic light emitting layer.

3. The method of claim 1, wherein the hole patterns are formed to overlap.

4. The method of claim 1, wherein the line hole patterns are formed to not overlap.

5. The method of claim 1, wherein the line hole patterns are formed at a pad region of the non-display region or at the non-display region including the pad region.

6. The method of claim 5, wherein the line hole pattern formed at the non-display region including the pad region includes a first hole pattern having curved portions surrounding a trimming line formed at edges of an upper and a lower of the pad region, and a second hole pattern extended from the first hole pattern having linear portions surrounding the display region at the non-display region located at an outside of the display region opposite to the pad region.

7. The method of claim 1, wherein at least one line hole pattern is formed in the gate insulating layer in the pad region.

8. The method of claim 1, wherein a polyimide layer and a plurality of buffer layers are interposed between the substrate and the plurality of thin film transistors.