CN111341807B

CN111341807B - Pixel defining structure and OLED display panel

Info

Publication number: CN111341807B
Application number: CN202010130613.2A
Authority: CN
Inventors: 张月; 侯文军; 孙力
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2023-01-24
Anticipated expiration: 2040-02-28
Also published as: CN111341807A

Abstract

The application discloses a pixel defining structure and an OLED display panel, which comprise a first pixel defining layer, wherein a plurality of rows of pixel defining areas are arranged in the first pixel defining layer, a plurality of sub-pixels with the same color in each row of pixel defining areas are sequentially arranged, and each row of pixel defining areas are of a zigzag structure; a second pixel defining layer is arranged in each row of pixel defining areas, and the second pixel defining layer comprises barriers arranged between the sub-pixels. According to the technical scheme provided by the embodiment of the application, the second pixel defining layer is arranged between the sub-pixels with the same color, meanwhile, the pixel defining area is arranged to be of the zigzag structure, each column of pixel defining area is conveniently separated into the sub-pixels with the required shapes, and compared with the conventional strip-shaped pixel defining area, the zigzag structure in the embodiment reduces the pulling force of foreign matters such as dust on ink, so that the line defect caused by the foreign matters in the pixel defining area is relieved, and the light emitting uniformity of an OLED device is improved.

Description

Pixel defining structure and OLED display panel

Technical Field

The present invention relates generally to the field of displays, and more particularly to a pixel defining structure, an OLED display panel.

Background

Compared with LCDs, organic electroluminescent devices (OLEDs) have advantages of self-luminescence, fast response, wide viewing angle, high brightness, vivid color, light weight, thin thickness, etc., and are considered as next-generation display technologies. OLEDs generally include a structure in which an anode layer, a hole transport layer, a hole injection layer, a pixel defining layer, an electron injection layer, an electron transport layer, a cathode layer, and the like are sequentially formed on a substrate.

The film forming method of the OLED mainly comprises an evaporation process or a solution process, wherein the evaporation process is mature in small-size application, and the technology is applied to mass production at present; the film forming methods of the solution process OLED mainly include inkjet printing, nozzle coating, spin coating, screen printing, and the like, wherein the inkjet printing technology is considered as an important method for realizing mass production of large-sized OLEDs due to its high material utilization rate and the realization of large-sized OLEDs.

The inkjet printing process requires a Pixel Defining Layer (PDL) to be formed on the electrodes of the display substrate in advance to define the precise flow of ink droplets into the designated sub-Pixel areas. In the ink-jet printing and drying process, the ink drops climb to the lyophobic surface of the pixel defining material layer along the material interface of the lyophilic pixel defining layer at the bottom, the thicker the material of the pixel defining layer is, the higher the climbing height of the ink drops is, the solute can be driven by the flow to migrate to the edges of the ink drops and finally deposited at the edges, and the thick and thin deposition morphology at the center of the edges is formed, so that the film formation in the pixels is very uneven, and the uneven light emission of the device can be caused.

Disclosure of Invention

In view of the above-mentioned drawbacks or deficiencies in the prior art, it is desirable to provide a pixel defining structure, an OLED display panel.

In a first aspect, a pixel defining structure is provided, which includes a first pixel defining layer, where a plurality of rows of pixel defining areas are disposed in the first pixel defining layer, a plurality of sub-pixels with the same color in each row of pixel defining areas are sequentially arranged, and each row of pixel defining areas is a zigzag structure;

and a second pixel defining layer is arranged in each column of the pixel defining area, and the second pixel defining layer comprises barriers arranged between the sub-pixels.

In a second aspect, an OLED display panel is provided, including the above pixel defining structure.

According to the technical scheme provided by the embodiment of the application, the second pixel defining layer is arranged between the sub-pixels with the same color, namely, the separation bars are arranged between the sub-pixels with the same color, the sub-pixels in each row are communicated with each other, and when the material with the same color is subjected to ink-jet printing in the pixel defining area in each row, the ink is uniformly distributed in the pixel area in each row; meanwhile, the pixel limiting area is arranged to be of a zigzag structure, each row of pixel limiting areas are conveniently separated into sub-pixels in the required shape, and compared with the conventional strip-shaped pixel limiting area, the zigzag structure in the embodiment reduces the pulling force of foreign matters such as dust on ink, so that the line defect caused by the foreign matters in the pixel limiting area is relieved, and the light emitting uniformity of the OLED device is improved.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings in which:

FIG. 1 is a schematic diagram of a pixel definition structure according to an embodiment;

FIG. 2 is a schematic diagram of another embodiment of a pixel definition structure;

fig. 3 is a schematic view of ink jet printing.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1, the present embodiment provides a pixel defining structure, including a first pixel defining layer 1, a plurality of rows of pixel defining areas 3 are disposed in the first pixel defining layer 1, a plurality of sub-pixels 31 with the same color in each row of the pixel defining areas 3 are sequentially arranged, and each row of the pixel defining areas 3 is a zigzag structure;

a second pixel defining layer 2 is arranged in each column of the pixel defining area 3, and the second pixel defining layer 2 comprises barriers arranged between the sub-pixels 31.

In the embodiment, the second pixel defining layer 2 is arranged between the sub-pixels with the same color, the partition is arranged between the sub-pixels, the materials with the same color are subjected to ink jet printing in each row of pixel defining areas 3, the ink can be uniformly distributed in each row of pixel areas, meanwhile, each row of pixel defining areas 3 are arranged into the zigzag structure, each row of pixel defining areas can be conveniently divided into the sub-pixels with the required shapes, and compared with the conventional strip-shaped pixel defining areas, the zigzag structure in the embodiment reduces the tension of foreign matters such as dust on the ink, so that the line defect caused by the foreign matters in the pixel defining areas is relieved, and the light emitting uniformity of the OLED device is improved.

Further, the first pixel defining layer 1 is lyophobic and the second pixel defining layer 2 is lyophilic.

In this embodiment, the first pixel defining layer 1 is set to have lyophobic property, and the second pixel defining layer 2 has lyophilic property, so that the problem of ink climbing in the circumferential direction of each sub-pixel is solved, and each sub-pixel is uniformly formed into a film.

Furthermore, each sub-pixel is a parallelogram structure, and each parallelogram structure comprises two groups of parallel line segments.

As shown in fig. 1 and fig. 2, each sub-pixel is configured as a parallelogram in this embodiment, including two sets of parallel line segments, for example, the parallelogram ABCD includes parallel line segments AB and CD and parallel line segments AD and BC, and the printing ink leveling is facilitated through the parallelogram structure, so that the problem of ink climbing can be solved in each pixel defining area 3 not only in the length direction but also in the width direction, so that the sub-pixels can be formed into a film uniformly, and the uniformity of the formed film of the pixels is improved.

Furthermore, a barrier is arranged between adjacent sub-pixels 31 in each column of the pixel defining area 3.

As shown in fig. 1, in the pixel defining area in this embodiment, a barrier is disposed between each adjacent sub-pixel, each sub-pixel is of a parallelogram structure, and the structure of each sub-pixel is beneficial to leveling of printing ink, so that the problem of ink climbing is reduced in the length direction and the width direction, so that the sub-pixels in each row can uniformly form a film, and the uniformity of the film formed in the pixel is improved.

Further, at least one set of parallel line segments in adjacent sub-pixels 31 are parallel to each other. The arrangement of the sub-pixels in this embodiment may have various forms, and may be shaped as shown in fig. 1, where the directions of the parallelograms of the adjacent sub-pixels are opposite, that is, the adjacent sub-pixels have a set of parallel line segments parallel to each other, for example, the parallel edges AD, BC of the first sub-pixel and the parallel edges EH, FG of the second sub-pixel in fig. 1 are parallel to each other, the parallel edges AB, CD of the first sub-pixel and the parallel edges EF, GH of the second sub-pixel are not parallel to each other, so as to form a zigzag structure, or the whole column of sub-pixels is obliquely arranged, and the two sets of parallel line segments of the adjacent sub-pixels are all parallel to each other and are separated by the second pixel defining layer 2, or the partition of the second pixel layer is obliquely arranged in each column of sub-pixels, so that each sub-pixel is a parallelogram, the above-mentioned problem of ink climbing in the long and wide directions can be solved, and the films can be uniformly formed in each sub-pixel.

Furthermore, every two sub-pixels 31 in each row of the pixel defining area 3 are provided with barriers.

As shown in fig. 2, in the pixel defining area in this embodiment, a retaining wall is disposed between every two adjacent sub-pixels, so that the two connected sub-pixels form an arrow shape, on one hand, the problem of ink climbing in the length and width directions of the printed ink is solved through the parallelogram structure of each sub-pixel, so that the sub-pixels can uniformly form a film, on the other hand, as shown in fig. 3, the arrow-shaped sub-pixels can be printed by using a plurality of nozzles 4 simultaneously when printing the ink, and in fig. 3, two nozzles are used for printing, so that the distance between the two nozzles is large, the mounting is suitable, the drop points of the two nozzles are respectively disposed at the upper and middle positions, and when one nozzle prints the ink, the ink is not uniformly discharged, and the two nozzles print together, so that the volume error between the ink droplets ejected by the two nozzles is averaged to a certain extent, the uniformity error between the pixels can be reduced to a certain extent, and the problem of non-uniform light emission in the inkjet printing pixel can be improved.

Furthermore, only one set of parallel line segments in adjacent sub-pixels are parallel to each other.

In this embodiment, two adjacent sub-pixels without retaining walls form a structure as shown in fig. 2, and only one set of parallel line segments of the adjacent sub-pixels are parallel to each other, and the directions of the parallelograms of the adjacent sub-pixels are opposite, so that the above advantages are provided.

Further, the first pixel defining layer 1 has a thickness of 1.3 μm to 1.6 μm, and the second pixel defining layer 2 has a thickness of not more than 1 μm.

In the embodiment, the thickness of the first pixel defining layer 1 is preferably 1.5 μm, the sub-pixels are separated by the second pixel defining layer 2, the thickness of the second pixel defining layer 2 is not more than 1 μm, the sub-pixels of the same color in each pixel defining area 3 are communicated, so that the ink is uniformly distributed, and each row of sub-pixels are uniformly formed; further, under the design, the organic light-emitting layer is arranged in a communication part formed between the second pixel defining layer and the first pixel defining layer, and the influence of transverse electric signal crosstalk of carriers in the layer is small, so that the optical uniformity of the organic light-emitting layer is kept, and the electrical stability of the organic light-emitting layer is ensured.

Further, each parallelogram base angle is 45-90 degrees. Through setting up every subpixel into the parallelogram in this application, the problem of marginal position ink climbing when solving every subpixel and printing, every parallelogram's base angle need not too little, control 45 to 90 can.

The scheme that provides in this application can improve the inhomogeneous problem of giving out light in the inkjet printing pixel, and easy operation easily volume production simultaneously.

The embodiment also provides an OLED display panel including the pixel defining structure.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention according to the present application is not limited to the specific combination of the above-mentioned features, but also covers other embodiments where any combination of the above-mentioned features or their equivalents is made without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.

Claims

1. A pixel defining structure is characterized by comprising a first pixel defining layer, wherein a plurality of columns of pixel defining areas are arranged in the first pixel defining layer, a plurality of sub-pixels with the same color in each column of pixel defining areas are sequentially arranged, each column of pixel defining areas are of a broken line structure, and two adjacent sub-pixels with the same color in each column of pixel defining areas are communicated;

and a second pixel defining layer is arranged in each row of the pixel defining areas, the second pixel defining layer comprises barriers arranged between the sub-pixels with different colors, and the first pixel defining layer and the second pixel defining layer are not overlapped.

2. The pixel defining structure of claim 1, wherein the first pixel defining layer is lyophobic and the second pixel defining layer is lyophilic.

3. The pixel defining structure of claim 2, wherein each of the sub-pixels is a parallelogram structure, each of the parallelogram structures comprising two sets of parallel line segments.

4. The pixel defining structure of claim 3, wherein only one set of parallel line segments in adjacent sub-pixels are parallel to each other.

5. A pixel defining structure according to any one of claims 1-4, wherein the first pixel defining layer has a thickness of 1.3 μm-1.6 μm and the second pixel defining layer has a thickness of no more than 1 μm.

6. An OLED display panel comprising the pixel defining structure of any one of claims 1-5.