Organic electroluminescent display panel and method for manufacturing the same

• US 10,461,137 B2
• Filed: 11/17/2017
• Issued: 10/29/2019
• Est. Priority Date: 03/29/2017
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Zhao, Dejiang
• Primary Examiner(s): Malsawma, Lex H
• Assistant Examiner(s): Jones, Eric W
• Application Number:
  US15/816,264
• Publication Number:
  US 20180286934A1
• Time in Patent Office: 711 Days
• Field of Search: 257 40, 257 59
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/353 characterised by the geometrical arrangement of the RGB subpixels
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/135 using ink-jet printing

Abstract

The disclosure provides an organic electroluminescent display panel, and a method for fabricating the same. The organic electroluminescent display panel includes a substrate, and a pixel defining layer and a light emitting layer arranged on the substrate, wherein the pixel defining layer includes a first pixel defining layer arranged on the substrate, and a second pixel defining layer arranged on the first pixel defining layer; the first pixel defining layer includes a plurality of first opening areas, each first opening area defines a sub-pixel light emitting area, and the light emitting layer is arranged in the first opening areas; and the second pixel defining layer includes a plurality of second opening areas, each second opening area defines a virtual pixel area, and each virtual pixel area includes at least two adjacent sub-pixel light emitting areas in the same color.

Claims

1. An organic electroluminescent display panel, comprising a substrate, and a pixel defining layer and a light emitting layer on the substrate, wherein:

the pixel defining layer comprises a first pixel defining layer on the substrate, a second pixel defining layer on the first pixel defining layer, and a third pixel defining layer between the first pixel defining layer and the second pixel defining layer;

the first pixel defining layer comprises a plurality of first opening areas, each of which defines a sub-pixel light emitting area, and the light emitting layer is arranged in the plurality of first opening areas;

the second pixel defining layer comprises a plurality of second opening areas, each of which defines a virtual pixel area comprising at least two adjacent sub-pixel light emitting areas in a same color; and

the third pixel defining layer comprises a plurality of third opening areas corresponding to the plurality of first opening areas in a one-to-one manner, and each of the plurality of third opening areas is not larger than a corresponding first opening area;

wherein respective virtual pixel areas defined by the plurality of second opening areas comprise a same number of sub-pixel light emitting areas; and

virtual pixel areas containing red sub-pixel light emitting areas, virtual pixel areas containing green sub-pixel light emitting areas, and virtual pixel areas containing blue sub-pixel light emitting areas are disposed alternately in each row of the respective virtual pixel areas; and

wherein sidewalls of respective first opening areas, respective second opening areas, and respective third opening areas are sloped, top areas of the respective first opening areas and the respective third opening areas are smaller than their corresponding bottom areas, and top areas of the respective second opening areas are greater than their corresponding bottom areas.

2. The organic electroluminescent display panel according to claim 1, wherein a material of the first pixel defining layer is a lyophilic material and a material of the second pixel defining layer is a lyophobic material.

3. The organic electroluminescent display panel according to claim 2, wherein a material of the third pixel defining layer is a lyophilic material, wherein a lyophilic performance of the material of the first pixel defining layer is higher than that of the material of the third pixel defining layer.

4. The organic electroluminescent display panel according to claim 1, wherein a thickness of the first pixel defining layer ranges from 400 nm to 600 nm.

5. The organic electroluminescent display panel according to claim 4, wherein a material of the third pixel defining layer is a lyophilic material, wherein a lyophilic performance of the material of the first pixel defining layer is higher than that of the material of the third pixel defining layer.

6. The organic electroluminescent display panel according to claim 1, wherein a thickness of the second pixel defining layer ranges from 800 nm to 2200 nm.

7. The organic electroluminescent display panel according to claim 6, wherein a material of the third pixel defining layer is a lyophilic material, wherein a lyophilic performance of the material of the first pixel defining layer is higher than that of the material of the third pixel defining layer.

8. The organic electroluminescent display panel according to claim 1, wherein a thickness of the third pixel defining layer ranges from 100 nm to 200 nm.

9. The organic electroluminescent display panel according to claim 1, wherein each virtual pixel area comprises four sub-pixel light emitting areas in a same color, which are arranged in two rows by two columns.

10. A method for manufacturing an organic electroluminescent display panel, the method comprising:

forming a first pixel defining layer and a third pixel defining layer on a substrate, wherein the first pixel defining layer comprises a plurality of first opening areas, each of which defines a sub-pixel light emitting area;

the third pixel defining layer comprises a plurality of third opening areas corresponding to the plurality of first opening areas in a one-to-one manner, and each of the plurality of third opening areas is not larger than a corresponding first opening area;

forming a second pixel defining layer on the substrate formed with the first pixel defining layer and the third pixel defining layer, wherein the second pixel defining layer comprises a plurality of second opening areas, each of which defines a virtual pixel area comprising at least two adjacent sub-pixel light emitting areas in a same color;

printing ink comprising a light emitting layer material in the plurality of second opening areas through an inkjet printing device; and

drying the ink to form a light emitting layer in the plurality of first opening areas;

wherein respective virtual pixel areas defined by the plurality of second opening areas comprise a same number of sub-pixel light emitting areas; and

virtual pixel areas containing red sub-pixel light emitting areas, virtual pixel areas containing green sub-pixel light emitting areas, and virtual pixel areas containing blue sub-pixel light emitting areas are disposed alternately in each row of the respective virtual pixel areas; and

wherein sidewalls of respective first opening areas, respective second opening areas, and respective third opening areas are sloped, top areas of the respective first opening areas and the respective third opening areas are smaller than their corresponding bottom areas, and top areas of the respective second opening areas are greater than their corresponding bottom areas.

11. The method according to claim 10, wherein the forming the first pixel defining layer and the third pixel defining layer on the substrate comprises:

depositing a thin film of the first pixel defining layer on the substrate, wherein a material of the thin film of the first pixel defining layer is a lyophilic material;

depositing a thin film of the third pixel defining layer on the thin film of the first pixel defining layer, wherein a material of the thin film of the third pixel defining layer is a lyophilic material, and a lyophilic performance of the material of the thin film of the first pixel defining layer is higher than that of the material of the thin film of the third pixel defining layer; and

dry etching the thin film of the third pixel defining layer, and the thin film of the first pixel defining layer to form the third pixel defining layer and the first pixel defining layer respectively, wherein an etch selectivity of the thin film of the first pixel defining layer to the thin film of the third pixel defining layer is more than 1.

12. The method according to claim 11, wherein the forming the second pixel defining layer on the substrate formed with the first pixel defining layer and the third pixel defining layer comprises:

forming a thin film of the second pixel defining layer on the substrate formed with the first pixel defining layer and the third pixel defining layer, wherein a material of the thin film of the second pixel defining layer is a lyophobic material; and

patterning the thin film of the second pixel defining layer to form the second pixel defining layer.

13. The method according to claim 10, wherein a thickness of the first pixel defining layer ranges from 400 nm to 600 nm.

14. The method according to claim 10, wherein a thickness of the second pixel defining layer ranges from 800 nm to 2200 nm.

15. The method according to claim 10, wherein each virtual pixel area comprises four sub-pixel light emitting areas in a same color, which are arranged in two rows by two columns.

16. The method according to claim 10, wherein a thickness of the third pixel defining layer ranges from 100 nm to 200 nm.