阅读说明：本技术 显示基板及其制备方法、显示装置 (Display substrate, preparation method thereof and display device ) 是由 贾文斌 廖金龙 孙力 马凯葓 朱飞飞 许名宏 于 2019-09-24 设计创作，主要内容包括：本发明实施例提供一种显示基板及其制备方法、显示装置；该显示基板包括衬底基板,所述衬底基板之上设有像素界定层,所述像素界定层之间形成有用于容纳墨滴的像素区,所述像素区包括中心区域以及围绕所述中心区域周围的边缘区域,所述边缘区域的表面能大于所述中心区域的表面能；本发明实施例显示基板能够降低显示基板出现润湿不充分的风险,提高打印品质。(The embodiment of the invention provides a display substrate, a preparation method thereof and a display device; the display substrate comprises a substrate, wherein pixel defining layers are arranged on the substrate, pixel areas for containing ink drops are formed between the pixel defining layers, each pixel area comprises a central area and an edge area surrounding the periphery of the central area, and the surface energy of the edge area is greater than that of the central area; the display substrate provided by the embodiment of the invention can reduce the risk of insufficient wetting of the display substrate and improve the printing quality.)

1. A display substrate is characterized by comprising a substrate base plate, wherein pixel defining layers are arranged on the substrate base plate, pixel areas for containing ink drops are formed among the pixel defining layers, each pixel area comprises a central area and an edge area surrounding the periphery of the central area, and the surface energy of the edge area is larger than that of the central area.

2. The display substrate of claim 1, wherein the edge region comprises a pixel electrode peripheral region disposed on the substrate base plate, and the central region comprises a pixel electrode central region disposed on the substrate base plate, and wherein a surface energy of the pixel electrode peripheral region is greater than a surface energy of the pixel electrode central region.

3. The display substrate of claim 1, wherein the edge region comprises a pixel electrode peripheral region disposed on the substrate, the central region comprises a pixel electrode central region disposed on the substrate and an organic film layer disposed on the pixel electrode central region, and the surface energy of the organic film layer is less than the surface energy of the pixel electrode peripheral region.

4. The display substrate of claim 3, wherein the organic film layer is made of organic silane.

5. The display substrate of claim 4, wherein the silane organic is octadecyltrichlorosilane or hexamethyldisilazane.

6. The display substrate according to claim 1, wherein the central region is rectangular, the edge region is rectangular ring-shaped, the width of the edge region along the long side direction is d1, the width of the edge region along the short side direction is d2, the length of the central region along the long side direction is d3, the length of the central region along the short side direction is d4, and the d1, d2, d3 and d4 satisfy the following relations: d1/d3 is more than or equal to 0.025 when the ratio is more than or equal to 0.05, and d2/d4 is more than or equal to 0.025 when the ratio is more than or equal to 0.05.

7. A display device comprising the display substrate according to any one of claims 1 to 6.

8. A method for preparing a display substrate is characterized by comprising the following steps:

forming pixel defining layers over a substrate, the pixel defining layers having pixel regions formed therebetween for receiving ink droplets;

and preprocessing the pixel area to enable the surface energy of the edge area of the pixel area to be larger than that of the central area of the pixel area.

9. The method of claim 8, wherein the pre-treating the pixel region comprises:

and cleaning the edge area through an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable the surface of the edge area to form hydroxyl.

10. The method of claim 8, wherein the pre-treating the pixel region comprises:

cleaning the central area by an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable the surface of the central area to form hydroxyl;

and placing the central area in an organic solution to form an organic film layer on the surface of the central area, wherein the surface energy of the organic film layer is less than that of the edge area.

Technical Field

The invention relates to the technical field of display, in particular to a display substrate, a preparation method thereof and a display device.

Background

Organic Light-Emitting diodes (OLEDs) have the advantages of self-luminescence, fast response, wide viewing angle, high brightness, bright color, lightness and thinness, and the like, compared with Liquid Crystal Displays (LCDs), and are considered as next generation Display technologies.

The film forming method of OLED mainly includes evaporation process or solution process. The evaporation process is mature in small size application, and the technology is applied to mass production at present, but the technology is expensive in material and low in material utilization rate, and the cost of product development is increased. The film forming method of the solution process OLED mainly includes 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-size.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a display substrate, a manufacturing method thereof, and a display device, so as to reduce the risk of insufficient wetting of the display substrate and improve the printing quality.

In order to solve the above technical problem, an embodiment of the present invention provides a display substrate including a substrate base plate, a pixel defining layer disposed on the substrate base plate, a pixel area formed between the pixel defining layers and used for accommodating ink droplets, the pixel area including a central area and an edge area surrounding the central area, the edge area having a surface energy greater than that of the central area.

Optionally, the edge region includes a pixel electrode peripheral region disposed on the substrate, the central region includes a pixel electrode central region disposed on the substrate, and a surface energy of the pixel electrode peripheral region is greater than a surface energy of the pixel electrode central region.

Optionally, the edge region includes a pixel electrode peripheral region disposed on the substrate, the central region includes a pixel electrode central region and an organic film layer disposed in an overlapping manner, the pixel electrode central region is disposed on the substrate, the organic film layer is disposed on the pixel electrode central region, and a surface energy of the organic film layer is less than a surface energy of the pixel electrode peripheral region.

Optionally, the organic film layer is made of silane organic.

Optionally, the silane organic is octadecyltrichlorosilane or hexamethyldisilazane.

Optionally, the central region is rectangular, the edge region is rectangular and annular, the edge region has a ring width along the long side direction of d1, the edge region has a ring width along the short side direction of d2, the central region has a length along the long side direction of d3, the central region has a length along the short side direction of d4, and d1, d2, d3 and d4 satisfy the following relations: d1/d3 is more than or equal to 0.025 when the ratio is more than or equal to 0.05, and d2/d4 is more than or equal to 0.025 when the ratio is more than or equal to 0.05.

The embodiment of the invention also provides a display device which comprises the display substrate.

The embodiment of the invention also provides a preparation method of the display substrate, which comprises the following steps: forming pixel defining layers over a substrate, the pixel defining layers having pixel regions formed therebetween for receiving ink droplets;

and preprocessing the pixel area to enable the surface energy of the edge area of the pixel area to be larger than that of the central area of the pixel area.

Optionally, the preprocessing the pixel region includes:

and cleaning the edge area through an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable the surface of the edge area to form hydroxyl.

Optionally, the preprocessing the pixel region includes:

cleaning the central area by an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable the surface of the central area to form hydroxyl;

placing the central area in an organic solution to form an organic film layer on the surface of the central area, wherein the surface energy of the organic film layer is less than that of the edge area

The invention provides a display substrate, a preparation method thereof and a display device, wherein the surface energy of the edge area of a pixel area is greater than the surface energy of the central area of the pixel area, so that the diffusion force of ink drops is increased, when the ink drops are dropped into the pixel area, the sufficient spreadability of the ink drops in the pixel area is improved, the ink drops can be spread to the edge area of the pixel area, the risk of insufficient wetting of the display substrate is reduced, and the printing quality is improved.

Of course, not all of the advantages described above need to be achieved at the same time in the practice of any one product or method of the invention. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the embodiments of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention. The shapes and sizes of the various elements in the drawings are not to scale and are merely intended to illustrate the invention.

FIG. 1 is a schematic diagram of a conventional display substrate after ink droplets are dropped into a pixel region;

FIG. 2 is a schematic structural diagram of a conventional display substrate after ink droplets are formed in a pixel region;

FIG. 3 is a schematic view of a display substrate according to a first embodiment of the present invention;

FIG. 4 is a cross-sectional view of a display substrate according to a first embodiment of the present invention;

FIG. 5 is a schematic view of a pixel region in a display substrate according to a first embodiment of the present invention;

FIG. 6 is a schematic view of a first embodiment of a display substrate after ink droplets are dropped into the pixel area;

FIG. 7 is a schematic structural diagram of a display substrate after ink droplets are formed in a pixel region according to a first embodiment of the present invention;

FIG. 8 is a cross-sectional view of a display substrate according to a second embodiment of the present invention.

Detailed Description

The following detailed description of embodiments of the invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

FIG. 1 is a schematic diagram of a conventional display substrate after ink droplets are dropped into a pixel region; fig. 2 is a schematic structural view of a conventional display substrate after ink droplets are formed in a pixel region. As shown in fig. 1 and 2, the conventional display substrate includes a substrate 10, a pixel defining layer 11 is disposed on the substrate 10, and a pixel region 12 for accommodating an ink droplet 13 is formed between the pixel defining layers 11. The conventional display substrate controls the ink droplets 13 to accurately flow into the designated pixel regions 12 by the printing apparatus during the ink jet printing process. In order to prevent the ink droplets 13 from being deflected, the ink droplets 13 are currently caused to strike at intermediate positions in the longitudinal direction of the pixel region 12. The ink droplets 13 are dropped into the pixel region 12 and then divided into two stages: collision spreading and leveling spreading, namely when the ink drop 13 is dropped into the pixel area 12, the ink drop 13 has a certain initial diameter, collides with the pixel area 12 at a certain speed, spontaneously spreads to reach the maximum radius under the driving action of kinetic energy, then starts to retract to reach the maximum diameter under the action of the surface tension of the ink drop 13, and the diameter is reduced to reach the final diameter. The edges and corners of the pixel area 12 are not sufficiently wetted by the ink droplets 13 during the impact spreading and the leveling spreading, and finally show dark spots or darkening, affecting the uniformity and quality of the panel, as shown in fig. 2.

The problem that the existing display substrate is insufficient in wetting in the ink-jet printing process is solved. The embodiment of the invention provides a display substrate, which comprises a substrate base plate, wherein pixel defining layers are arranged on the substrate base plate, pixel areas for containing ink drops are formed between the pixel defining layers, each pixel area comprises a central area and an edge area surrounding the periphery of the central area, and the surface energy of the edge area is greater than that of the central area.

According to the display substrate provided by the embodiment of the invention, the surface energy of the edge area of the pixel area is greater than that of the central area of the pixel area, so that the diffusion force of ink drops is increased, when the ink drops are dripped into the pixel area, the sufficient spreadability of the ink drops in the pixel area is improved, the ink drops can be spread to the edge area of the pixel area, the risk of insufficient wetting of the display substrate is reduced, and the printing quality is improved.

The technical solution of the embodiment of the present invention is explained in detail by the specific embodiment below.

First embodiment

FIG. 3 is a schematic view of a display substrate according to a first embodiment of the present invention; FIG. 4 is a cross-sectional view of a display substrate according to a first embodiment of the present invention. As shown in fig. 3 and 4, the display substrate according to the embodiment of the invention includes a substrate 10, a pixel defining layer 11 is disposed on the substrate 10, and a pixel region 12 for receiving ink droplets is formed between the pixel defining layers 11. The pixel area 12 comprises a central area 121 and an edge area 122 surrounding the central area 121, the surface energy of the edge area 122 is greater than that of the central area 121, so that the diffusion force of ink drops dropped into the pixel area 12 is increased, when the ink drops are dropped into the pixel area 12, the sufficient spreadability of the ink drops in the pixel area 12 is improved, the ink drops can be spread to the edge area 122 of the pixel area 12, the risk of insufficient wetting of the display substrate is reduced, and the printing quality is improved.

The principle of the display substrate of the embodiment of the invention for reducing the risk of insufficient wetting is as follows: when the ink drops are dripped into the pixel area, the ink drops have a certain initial diameter, the ink drops collide with the pixel area at a certain speed, the ink drops are spread spontaneously under the driving action of kinetic energy to reach the maximum radius, at the moment, the ink drops cover the central area and the edge area of the pixel area, and then the ink drops begin to retract under the action of the surface tension of the ink drops. Meanwhile, due to the difference of the surface energy of the central area and the surface energy of the edge area, the diffusion force of the ink drops is increased, when the ink drops are dropped into the pixel area, the sufficient spreadability of the ink drops in the pixel area is improved, and the ink drops can cover the central area and the edge area.

As shown in fig. 3, the edge region 122 includes a pixel electrode peripheral region 14 disposed on the substrate base plate 10, and the central region 121 includes a pixel electrode central region 15 disposed on the substrate base plate 10; the pixel electrode peripheral region 14 surrounds the pixel electrode central region 15. Wherein, the surface energy of the peripheral region 14 of the pixel electrode is made larger than that of the central region 15 of the pixel electrode by pre-treating the surface of the peripheral region 14 of the pixel electrode, so as to realize that the surface energy of the edge region 122 is larger than that of the central region 121.

FIG. 5 is a schematic structural diagram of a pixel region in a display substrate according to a first embodiment of the invention. As shown in fig. 5, the central region 121 is rectangular, the edge region 122 is rectangular ring-shaped, the ring width of the edge region 122 along the long side direction is d1, the ring width of the edge region 122 along the short side direction is d2, the length of the central region 121 along the long side direction is d3, and the length of the central region 121 along the short side direction is d4, where d1, d2, d3, and d4 satisfy the following relations: d1/d3 is more than or equal to 0.025 when the ratio is more than or equal to 0.05, and d2/d4 is more than or equal to 0.025 when the ratio is more than or equal to 0.05.

The following further illustrates the technical solution of the present embodiment through the inkjet printing process of the display substrate of the present embodiment.

FIG. 6 is a schematic view of a first embodiment of a display substrate after ink droplets are dropped into the pixel area; fig. 7 is a schematic structural view of a display substrate according to the first embodiment of the present invention after ink droplets are formed in a pixel region. As shown in fig. 6 and 7, the inkjet printing process of the display substrate of the present embodiment is:

dropping ink drops 13 into the pixel area 12, wherein five ink drops 13 are arranged at intervals along the central line of the long side direction of the pixel area 12, when the ink drops 13 are dropped into the pixel area 12, the ink drops have a certain initial diameter, collide with the pixel area 12 at a certain speed, and spontaneously spread to reach the maximum radius under the driving action of kinetic energy, and at the moment, the ink drops 13 cover the central area 121 and the edge area 122 of the pixel area 12; then the surface of the edge area 122 can inhibit the retraction of the ink drop 13, so that the ink drop 13 can be fully spread to cover the whole edge area 122; finally, the ink droplets 13 in the pixel region 12 are dried, so that the ink droplets 13 form a pixel functional layer covering the entire pixel region 12, as shown in fig. 7.

In summary, the display substrate according to the embodiment of the invention can reduce the risk of insufficient wetting of the display substrate, and improve the printing quality.

Second embodiment

FIG. 8 is a cross-sectional view of a display substrate according to a second embodiment of the present invention. As shown in fig. 8, the present embodiment is an extension of the first embodiment, and the main structure of the array substrate of the present embodiment is the same as that of the first embodiment, and is different from the first embodiment in that the edge region of the display substrate of the present embodiment includes a pixel electrode peripheral region 14 disposed on a substrate 10, the central region includes a pixel electrode central region 15 and an organic film 16 disposed in a stacked manner, the pixel electrode central region 15 is disposed on the substrate 10, the organic film 16 is disposed on the pixel electrode central region 15, and the surface energy of the organic film 16 is smaller than the surface energy of the pixel electrode peripheral region 14, so that the surface energy of the edge region of the pixel region is larger than the surface energy of the central region. The organic film layer 16 is made of organic silane, for example, the organic silane is octadecyltrichlorosilane or hexamethyldisilazane.

The present embodiment has the technical effects of the first embodiment described above, namely, reducing the risk of insufficient wetting of the display substrate and improving the printing quality.

Third embodiment

The embodiment of the invention also provides a display device which comprises the display substrate. The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.

Fourth embodiment

Based on the technical idea of the foregoing embodiment, the present embodiment provides a method for manufacturing a display substrate, including:

s1, forming a pixel electrode layer on the substrate base plate;

s2, forming pixel definition layers on the pixel electrode layers of the substrate base plate, wherein pixel areas for containing ink drops are formed between the pixel definition layers;

and S3, preprocessing the pixel area to enable the surface energy of the edge area of the pixel area to be larger than that of the central area of the pixel area.

Wherein, in one embodiment, step S3 includes:

s31, forming a photoresist layer on the pixel region;

s32, exposing and developing the edge area of the pixel area to expose the pixel electrode layer of the edge area;

s33, cleaning the exposed pixel electrode layer through an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable hydroxyl groups to be formed on the surface of the pixel electrode layer in the edge area;

and S34, stripping the residual photoresist layer on the pixel area to expose the pixel electrode layer in the central area. Wherein, the surface energy of the edge area of the pixel area is larger than that of the central area of the pixel area.

In another embodiment, step S3 includes:

s31, forming a photoresist layer on the pixel region;

s32, exposing and developing the central area of the pixel area to expose the pixel electrode layer of the central area;

s33, cleaning the exposed pixel electrode layer through an ultraviolet ozone cleaning machine or a plasma cleaning machine to enable hydroxyl to be formed on the surface of the pixel electrode layer in the central area;

s34, placing the pixel electrode layer in the central area in a silane organic matter solution, and under a vacuum condition, enabling a silane organic matter in the silane organic matter solution to chemically react with hydroxyl on the surface of the pixel electrode layer in the central area, so that an organic film layer is formed on the surface of the pixel electrode layer in the central area. Wherein the organic film layer is a monomolecular layer, and the material of the organic film layer is a silane organic matter;

and S35, stripping the residual photoresist layer on the pixel area to expose the pixel electrode layer in the edge area. The surface energy of the organic film layer is less than that of the pixel electrode layer in the edge area, and the surface energy of the edge area of the pixel area is greater than that of the central area of the pixel area.

According to the preparation method of the display substrate, the surface energy of the edge area of the pixel area is larger than that of the central area of the pixel area, so that the diffusion force of the ink drops is increased, when the ink drops are dripped into the pixel area, the sufficient spreadability of the ink drops in the pixel area is improved, the ink drops can be spread to the edge area of the pixel area, the risk of insufficient wetting of the display substrate is reduced, and the printing quality is improved.

In the description of the embodiments of the present invention, it should be understood that the terms "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.