Fabrication method of a pixel structure of an electroluminescent display panel

• US 9,065,079 B2
• Filed: 08/06/2014
• Issued: 06/23/2015
• Est. Priority Date: 12/08/2011
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Liu, Meng-Yu, Liu, Chih-Che, Hsu, Shih-Feng
• Primary Examiner(s): GIESY, ADAM
• Application Number:
  US14/452,547
• Publication Number:
  US 20140342483A1
• Time in Patent Office: 321 Days
• Field of Search: 345/76, 345/77, 345/80, 345/84
• US Class Current: 1/1
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A fabrication method of a pixel structure of an electroluminescent display panel includes the following steps. A substrate is provided. A first anode, a second anode and a third anode are formed in a first sub-pixel region, a second sub-pixel region and a third sub-pixel region respectively. A first organic light-emitting layer is formed in the first sub-pixel region by using a first fine metal mask. A second organic light-emitting layer is formed in the second sub-pixel region and the third sub-pixel region by using a second fine metal mask. A first cathode, a second cathode and a third cathode are formed in the first sub-pixel region, the second sub-pixel region, and the third sub-pixel region, respectively. The first micro cavity in the first sub-pixel region, the second micro cavity in the second sub-pixel region and the third micro cavity have different cavity lengths.

Claims

1. A fabrication method of pixel structure of electroluminescent display panel, comprising:

providing a substrate, and defining a first sub-pixel region, a second sub-pixel region, and a third sub-pixel region on the substrate;

respectively forming a first anode, a second anode, and a third anode in the first sub-pixel region, the second sub-pixel region, and the third sub-pixel region of the substrate;

forming a first organic light-emitting layer in the first sub-pixel region by using a first fine metal mask, wherein the first organic light-emitting layer comprises a first organic light-emitting material;

forming a second organic light-emitting layer in the second sub-pixel region and the third sub-pixel region by using a second fine metal mask; and

respectively forming a first cathode, a second cathode, and a third cathode in the first sub-pixel region, the second sub-pixel region, and the third sub-pixel region of the substrate;

wherein a first micro cavity is formed between the first anode and the first cathode in the first sub-pixel region, a second micro cavity is formed between the second anode and the second cathode in the second sub-pixel region, and a third micro cavity is formed between the third anode and the third cathode in the third sub-pixel region, and the first micro cavity, the second micro cavity, and the third micro cavity have different cavity lengths.

2. The fabrication method of pixel structure of electroluminescent display panel of claim 1, wherein the second organic light-emitting layer comprises a second organic light-emitting material and a third organic light-emitting material.

3. The fabrication method of pixel structure of electroluminescent display panel of claim 2, wherein the second organic light-emitting layer is a composite-layered organic light-emitting layer, and a formation process of the second organic light-emitting layer comprises:

performing an evaporation process by using the second fine metal mask to form the second organic light-emitting material in the second sub-pixel region and the third sub-pixel region; and

performing another evaporation process by using the same second fine metal mask to form the third organic light-emitting material in the second sub-pixel region and the third sub-pixel region.

4. The fabrication method of pixel structure of electroluminescent display panel of claim 2, wherein the second organic light-emitting layer is a single-layered organic light-emitting layer, and a formation process of the second organic light-emitting layer comprises performing a co-evaporation process by using the second fine metal mask to form the second organic light-emitting material and the third organic light-emitting material in the second sub-pixel region and the third sub-pixel region simultaneously.

5. The fabrication method of pixel structure of electroluminescent display panel of claim 1, further comprising forming at least one first hole injection layer in the first sub-pixel region, forming at least one second hole injection layer in the second sub-pixel region, and forming at least one third hole injection layer the third sub-pixel region before forming the first organic light-emitting layer and the second organic light-emitting layer, wherein the at least one first hole injection layer, the at least one second hole injection layer, and the at least one third hole injection layer have different thicknesses to render the first micro cavity, the second micro cavity, and the third micro cavity different cavity lengths.

6. The fabrication method of pixel structure of electroluminescent display panel of claim 1, further comprising forming at least one first hole injection layer in the first sub-pixel region, forming at least one second hole injection layer in the second sub-pixel region, and forming at least one third hole injection layer in the third sub-pixel region before forming the first organic light-emitting layer and the second organic light-emitting layer, wherein one of the at least one first hole injection layer, the at least one second hole injection layer, and the at least one third hole injection layer has a different thickness from the thicknesses of the other two of the at least one first hole injection layer, the at least one second hole injection layer, and the at least one third hole injection layer, and one of the first anode, the second anode, and the third anode has a different thickness from the thicknesses of the other two of the first anode, the second anode, and the third anode to render the first micro cavity, the second micro cavity, and the third micro cavity different cavity lengths.