Flexible organic electroluminescent device and method for fabricating the same

• US 9,876,064 B2
• Filed: 12/20/2013
• Issued: 01/23/2018
• 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:
  US14/136,014
• Publication Number:
  US 20150060778A1
• Time in Patent Office: 1,495 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. An organic electroluminescent device having flexible characteristics, comprising:

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

a plurality of thin film transistors (TFTs) on a buffer layer on the substrate in the respective pixel regions on the substrate;

an interlayer insulating layer in the display region including the TFTs on a gate insulating layer and the buffer layer, and the non-display region;

a passivation layer on the interlayer insulating layer,

wherein at least one line hole pattern is formed in one or more of the interlayer insulating layer and the passivation layer in the pad region of the non-display region in a direction substantially parallel with the longer side of the pad region;

a planarization layer on the passivation layer;

a first electrode in each pixel region on the planarization layer and connected to a drain electrode of a respective one of the plurality of TFTs via a contact hole through the planarization layer and the passivation layer;

a pixel defining layer around each pixel region of the substrate including the first electrode and the non-display region;

an organic light emitting layer being separately in each pixel region on the first electrode;

a second electrode on the organic light emitting layer.

2. The organic electroluminescent device of claim 1, further comprising:

a lower passivation layer on an entire surface of the substrate including the second electrode;

an organic layer on the lower passivation layer in the display region;

an upper passivation layer on the lower passivation layer including the organic layer;

a barrier film disposed to face the substrate; and

a polarization plate attached to the barrier film.

3. The organic electroluminescent device of claim 1, wherein the substrate is a glass substrate is made of a flexible material.

4. The organic electroluminescent device of claim 1, wherein the at least one line hole pattern overlaps when more than one.

5. The organic electroluminescent device of claim 1, wherein the at least one line hole pattern does not overlap when more than one.

6. The organic electroluminescent device of claim 1, wherein the at least one line hole pattern is formed at a pad region of the non-display region or at the non-display region including the pad region.

7. The organic electroluminescent device of claim 1, wherein at least one line hole pattern is also in the pad region of the gate insulating layer.

8. The organic electroluminescent device 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.

9. An organic electroluminescent device having flexible characteristics, comprising:

a substrate having a display region including a plurality of pixel regions and a non-display region including a pad region outside the display region, the pad region defined by a shorter side and a longer side;

a plurality of thin film transistors (TFTs) on a buffer layer on the substrate in the respective pixel regions on the substrate;

an interlayer insulating layer in the display region including the TFTs on a gate insulating layer and the buffer layer, and the non-display region;

a passivation layer on the interlayer insulating layer,

wherein at least one line hole pattern is formed in one or more of the interlayer insulating layer and the passivation layer in the pad region of the non-display region in a direction substantially parallel with the longer side of the pad region;

a planarization layer on the passivation layer;

a first electrode in each pixel region on the planarization layer and connected to a drain electrode of a respective one of the plurality of TFTs via a contact hole through the planarization layer and the passivation layer;

a pixel defining layer around each pixel region of the substrate including the first electrode and the non-display region;

an organic light emitting layer being separately in each pixel region on the first electrode;

a second electrode on the organic light emitting layer,

wherein the at least one line hole pattern is formed at a pad region of the non-display region or at the non-display region including the pad region, and

wherein the at least one line hole pattern includes a first hole pattern having curve 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.

10. An organic electroluminescent device having flexible characteristics, comprising:

a substrate having a display region including a plurality of pixel regions and a non-display region including a pad region outside the display region;

a plurality of thin film transistors (TFTs) on a buffer layer on the substrate in the respective pixel regions on the substrate;

an interlayer insulating layer in the display region including the TFTs on a gate insulating layer and the buffer layer, and the non-display region, and having at least one line hole pattern formed only in the pad region of the non-display region;

a passivation layer directly on the interlayer insulating layer in the display region,

wherein the at least one line hole pattern is formed in at least one of the interlayer insulating layer and the passivation layer and located at the non-display region, and has a depth of the respective interlayer insulating layer and the passivation layer;

a planarization layer on the passivation layer;

a first electrode in each pixel region on the planarization layer and connected to a drain electrode of a respective one of the plurality of TFTs via a contact hole through the planarization layer and the passivation layer;

a pixel defining layer around each pixel region of the substrate including the first electrode and the non-display region;

an organic light emitting layer being separately only in each pixel region on the first electrode;

a second electrode on substantially the entire surface of the display region directly contacting the organic light emitting layer, the pixel defining layer, and the planarization layer; and

a lower passivation layer on the entire surface of the substrate including directly contacting the second electrode in the display region and the passivation layer in the pad region,

wherein the at least one line hole pattern includes a first hole pattern having curve 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.

11. The organic electroluminescent device of claim 10, further comprising:

an organic layer on the lower passivation layer including the organic layer;

a barrier film disposed to face the substrate; and

a polarization plate attached to the barrier film.

12. The organic electroluminescent device of claim 10, 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.