Display substrate and display device

Abstract

The present application discloses a display substrate and a display device. The display substrate comprises: a substrate having a display area and a peripheral area, the display area having an organic light-emitting device, the peripheral area including at least one retaining wall, and the substrate further comprising an encapsulation structure and a raised structure. The encapsulation structure is configured to seal the organic light-emitting device on the substrate, and the at least one raised structure is located in at least one of the following areas: a side of the retaining wall close to the display area; between two adjacent retaining walls; and a side of the retaining wall away from the display area. The retaining wall comprises an organic layer, the organic layer comprising at least one of a pixel defining layer and a planarization layer. The orthographic projection of the raised structure on the substrate does not overlap with the orthographic projection of the organic layer on the substrate. The raised structure is an insulating material on the side of the encapsulation structure facing the substrate. Thus, the provision of the raised structure can reduce the occurrence of black spots in the display area and improve the display effect.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular, to a display substrate and a display device. Background Art

[0002] Flexible display technology has revolutionized the full-screen display capabilities of smartphones and other end products. Display devices based on this technology, such as notch screens and punch-hole displays, have emerged on the market. While AMOLED displays offer numerous advantages, their organic light-emitting materials and devices are extremely sensitive to water and oxygen. Even a small amount of water and oxygen seeping into the display panel can cause black spots in the display area, leading to display failure and failure to meet user expectations.

[0003] Therefore, current display substrates and display devices still need to be improved. Summary of the Invention

[0004] The present application aims to alleviate or solve at least one of the above-mentioned problems to at least some extent.

[0005] In one aspect of the present application, a display substrate is provided, comprising: a substrate having a display area and a peripheral area, the display area having an organic light-emitting device, the peripheral area including at least one retaining wall, the substrate further having an encapsulation structure and a raised structure, the encapsulation structure being configured to seal the organic light-emitting device on the substrate, the at least one raised structure being located in at least one of the following areas: a side of the retaining wall close to the display area; between two adjacent retaining walls; and a side of the retaining wall away from the display area, the retaining wall comprising an organic layer, the organic layer comprising at least one of a pixel defining layer and a planarization layer, the orthographic projection of the raised structure on the substrate not coinciding with the orthographic projection of the organic layer on the substrate, and the raised structure being an insulating material on the side of the encapsulation structure facing the substrate. Thus, the provision of the raised structure can reduce the occurrence of black spots in the display area and improve the display effect.

[0006] According to an embodiment of the present application, the peripheral area includes one retaining wall and a plurality of protruding structures, and the plurality of protruding structures are located between the retaining wall and the display area, thereby further improving the display effect.

[0007] According to an embodiment of the present application, the peripheral area includes a plurality of retaining walls and a plurality of protruding structures, and each retaining wall has adjacent protruding structures on both sides, thereby further improving the display effect.

[0008] According to an embodiment of the present application, the display area is provided with a gate layer, an interlayer dielectric layer, a source / drain metal layer, the planarization layer, an anode layer, and the pixel definition layer, which are stacked in sequence. The retaining wall includes a first retaining wall and a second retaining wall. The first retaining wall is located on a side of the second retaining wall away from the display area, and the height of the first retaining wall is greater than that of the second retaining wall. This further improves the water vapor barrier performance.

[0009] According to an embodiment of the present application, the organic layer of the first barrier wall includes the planarization layer and the pixel definition layer stacked in sequence, thereby simplifying the preparation process of the display substrate.

[0010] According to an embodiment of the present application, the organic layer of the second barrier wall includes the pixel defining layer, thereby simplifying the preparation process of the display substrate.

[0011] According to an embodiment of the present application, the raised structure is integrally formed with the interlayer dielectric layer, the surface of the raised structure near the substrate is flush with the surface of the first retaining wall near the substrate, and the raised structure and the second retaining wall are spaced apart in a direction perpendicular to the substrate. This simplifies the display substrate manufacturing process.

[0012] According to an embodiment of the present application, the peripheral region further includes a second interlayer dielectric layer, the second interlayer dielectric layer being located between the interlayer dielectric layer and the source / drain metal layer. The raised structure is formed by the second interlayer dielectric layer. The surface of the raised structure near the substrate is flush with the surface of the first retaining wall near the substrate. The raised structure and the second retaining wall are spaced apart in a direction perpendicular to the substrate. This simplifies the display substrate manufacturing process.

[0013] According to an embodiment of the present application, the anode layer and the source / drain metal layer located on the side of the protruding structure away from the substrate both have protruding portions facing the side away from the substrate, thereby further improving the water and oxygen barrier effect.

[0014] According to an embodiment of the present application, the protruding structure includes the anode layer, and the surface of the protruding structure close to the substrate is flush with the surface of the second retaining wall close to the substrate, thereby simplifying the preparation process of the display substrate.

[0015] In another aspect of the present application, a display device is provided, wherein the display device includes the aforementioned display substrate. Thus, the display device has all the features and advantages of the aforementioned display substrate, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 A schematic structural diagram of a display substrate according to an embodiment of the present application is shown;

[0018] Figure 2 A schematic diagram showing a GDS defect in a display device in the related art;

[0019] Figure 3 A schematic structural diagram of a display substrate in related art is shown;

[0020] Figure 4 A schematic diagram showing a GDS defect in a display substrate in the related art is shown;

[0021] Figure 5 A schematic diagram showing a principle of a display substrate blocking water and oxygen according to one embodiment of the present application is shown;

[0022] Figure 6 shows a schematic structural diagram of a display substrate according to yet another embodiment of the present application;

[0023] Figure 7 A schematic diagram showing the principle of a display substrate blocking water and oxygen according to yet another embodiment of the present application is shown.

[0024] Description of reference numerals:

[0025] 1: Display area; 2: Peripheral area: 10: Planarization layer; 20: Pixel definition layer; 30: Support column layer; 110: Substrate; 120: Barrier layer; 130: Interlayer dielectric layer; 131, 132: Raised structure; 140: Source / drain metal layer; 210: Anode layer; 220: Cathode layer; 300: Encapsulation structure; 310: First water / oxygen barrier layer; 320: Inkjet printing layer; 330: Second water / oxygen barrier layer. DETAILED DESCRIPTION

[0026] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0027] In one aspect of the present application, a display substrate is provided. Figure 1The display device comprises a substrate 110 having a display area and a peripheral area. The display area comprises an organic light-emitting device (OLED). The peripheral area comprises at least one retaining wall. Substrate 110 further comprises an encapsulation structure 300 and a raised structure 131. The encapsulation structure 300 is configured to seal the OLED on substrate 110. The at least one raised structure 131 is located in at least one of the following areas: a side of the retaining wall close to the display area 1; between two adjacent retaining walls; and a side of the retaining wall away from the display area 1. The retaining wall comprises an organic layer, which includes at least one of a pixel defining layer 20 and a planarization layer 10. The orthographic projection of the raised structure 131 on substrate 110 does not overlap with the orthographic projection of the organic layer (at least one of the pixel defining layer 20 and the planarization layer 10) on substrate 110. The raised structure 131 is an insulating material on the side of the encapsulation structure 300 facing substrate 110. The provision of the raised structure 110 can reduce the occurrence of black spots in the display area 1 and improve the display effect.

[0028] For ease of understanding, the principle of how the display substrate in this application has the above-mentioned beneficial effects is explained below:

[0029] refer to Figure 3 In the related art, a retaining wall is usually set on the side of the peripheral area close to the display area (the area in the peripheral area where the retaining wall is set is called the Dam area) to prevent the inkjet printing layer in the display area from flowing to the control area and causing problems. The molding process of the organic layer in the Dam area may include the following steps: first, the entire surface is coated with photoresist and heated to solidify it, then the cured photoresist is exposed to de-crosslink with the mask, and the excess photoresist is removed by a cleaning solution to achieve patterning of the photoresist, exposing the excess organic layer to be removed; then, the excess organic layer is removed by exposure and development to achieve patterning of the organic layer. In the present application, the inventors found that, with reference to Figure 4 In the related art, when the display substrate is undergoing an organic layer forming process, taking the organic layer as the pixel definition layer 20' as an example, when there is an abnormal exposure process, such as insufficient exposure capability due to low exposure, for example, the uneven surface of the substrate 110 will cause photoresist residues in the grooves. Then, when the excess organic layer is removed by subsequent exposure and development, the surface of the organic layer to be removed is still covered with solidified photoresist, so that the exposure process cannot completely remove the excess organic layer 20', and some residues will still remain (see Figure 4 The dotted box A and the dotted box B in the figure cause the first water and oxygen barrier layer 310 to have insufficient packaging capacity, so that water vapor can flow along the Figure 4 After entering the display substrate in the direction indicated by the left arrow, it will further enter the display area along the residual pixel definition layer 20' in the peripheral area and oxidize the light-emitting material in the organic light-emitting device. Figure 2 , forming GDS (Growing Dark Spot) black spots.

[0030] In this application, reference is made to Figure 1 、 Figure 5 、 Figure 6 and Figure 7 By designing a raised structure in the Dam area, a jagged film morphology is formed in the Dam area. When the organic layer forming process in the peripheral area is performed, the raised structure 131 can be used to raise the photoresist at the corresponding position, so that it is closer to the exposure light source, thereby making the photoresist to be removed more effectively de-crosslinked after exposure, and more completely removed by subsequent immersion, so that the surface of the organic layer 20 to be removed is not covered with solidified photoresist, so that the exposure process can remove the excess organic layer, especially the position where the raised structure is located (see Figure 5 At the dotted box C2 and the dotted box D2; Figure 7 Even if the organic layer 20 remains at the position where the protrusion structure 131 is not provided, since the organic layer 20 at the position where the protrusion structure 131 is provided is completely removed, when the water vapor flows along the protrusion structure 131, the organic layer 20 at the position where the protrusion structure 131 is provided is completely removed. Figure 5 After entering the display substrate at the position indicated by the arrow on the left, the water vapor will be blocked at the protruding structure 131. The setting of the protruding structure 131 also effectively extends the invasion path of water vapor, enhances the ability of the display substrate to isolate water vapor, and effectively reduces the formation of GDS black spots.

[0031] For ease of understanding, the following briefly describes the process for forming the raised structure. Taking the raised structure formed by the interlayer dielectric layer 130 as an example, first, a whole layer of the interlayer dielectric layer 130 can be deposited on the surface of the substrate 110 by a CVD process; then, a photoresist is covered on the surface of the interlayer dielectric layer 130 away from the substrate, and a patterned photoresist layer is formed by an exposure mask process combined with a developer; then, the excess interlayer dielectric layer 130 is removed by dry etching (such as an exposure process); finally, the remaining photoresist layer is removed to obtain a display substrate with a raised structure 131. Specifically, the film layer forming the raised structure is not particularly limited. For example, referring to Figure 1 , the film layer forming the protruding structure 131 may be the interlayer dielectric layer 130; Figure 6 The film layer forming the protruding structure 132 may be a second interlayer dielectric layer; the film layer forming the protruding structure may also be an anode layer.

[0032] According to some embodiments of the present application, in order to simplify the manufacturing process, the protruding structure can be formed with the help of conventional processes on the display substrate. For example, the protruding structure can be formed simultaneously with the help of conventional display area patterning processes or bending area patterning processes.

[0033] According to some embodiments of the present application, the number and location of the retaining walls and raised structures are not particularly limited. For example, when the peripheral area includes only one retaining wall and multiple raised structures, the multiple raised structures can be located between the retaining wall and the display area 1. During the exposure process, the closer to the display area, the more exposure per unit area. When multiple raised structures are located between the retaining wall and the display area 1, they receive more exposure during the exposure process of the aforementioned photoresist layer and the exposure process of the redundant organic layer, making it easier to remove the photoresist on the raised structures. Accordingly, the subsequent removal of the organic layer is more complete.

[0034] In the description of this application, “plurality” means two or more.

[0035] According to some embodiments of the present application, the number and position of the retaining walls and the protruding structures are not particularly limited. For example, when the peripheral area includes a plurality of retaining walls and a plurality of protruding structures, Figure 1 and Figure 6 Both sides of each retaining wall may have adjacent protruding structures 131 / 132, that is, at least one protruding structure should be set between two adjacent retaining walls, so as to effectively extend the water vapor intrusion path and block the water vapor intrusion path.

[0036] According to some embodiments of the present application, reference 1 and Figure 6 The structure within the display area 1 is not particularly limited. For example, the display area 1 includes a gate layer (not shown), an interlayer dielectric layer 130, a source / drain metal layer (not shown), a planarization layer 10, an anode layer 210, and a pixel definition layer (not shown). According to other embodiments of the present application, a barrier layer 120 and other conventional film structures may be further included between the interlayer dielectric layer 130 and the substrate 110. Persons skilled in the art may select these structures based on actual conditions.

[0037] According to some embodiments of the present application, the structure of the retaining wall is not particularly limited. For example, the retaining wall may include a first retaining wall and a second retaining wall, wherein the first retaining wall is located on a side of the second retaining wall away from the display area 1. The height of the first retaining wall may be greater than that of the second retaining wall. Since the height of the first retaining wall is greater than that of the second retaining wall, a certain buffer space can be provided for the flow screen of the inkjet-printed layer 320 in the display area 1. According to one embodiment of the present application, the retaining wall may include only the first retaining wall.

[0038] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0039] According to some embodiments of the present application, the composition of the first retaining wall is not particularly limited. For example, Figure 1 and Figure 6The organic layer of the first retaining wall may include a planarization layer 10 and a pixel definition layer 20 stacked in sequence. Furthermore, the first retaining wall may further include a support column layer 30, which is located on the side of the pixel definition layer 20 away from the planarization layer 10, thereby effectively simplifying the preparation process of the display substrate.

[0040] According to some embodiments of the present application, the composition of the second retaining wall is not particularly limited. For example, Figure 1 and Figure 6 The organic layer of the second retaining wall may include a pixel defining layer 20. Furthermore, the second retaining wall may further include a support column layer 30. The support column layer 30 is located on the side surface of the pixel defining layer 20 away from the substrate 110, thereby effectively simplifying the preparation process of the display substrate.

[0041] For ease of understanding, the following description is made by taking an example in which the first retaining wall includes a planarization layer 10 and a pixel defining layer 20 stacked in sequence, and the second retaining wall includes a pixel defining layer 20:

[0042] According to some embodiments of the present application, the composition of the protrusion structure is not particularly limited, for example, Figure 1 The raised structure 131 and the interlayer dielectric layer 130 can be formed as one piece, wherein the surface of the raised structure 131 close to the substrate 110 is flush with the surface of the first retaining wall close to the substrate (the surface of the planarization layer 10 close to the substrate), and the raised structure 131 and the second retaining wall are spaced apart in a direction perpendicular to the substrate 110. For example, the raised structure 131 and the second retaining wall can separate the source and drain metal layer 140 and the anode layer 210 in a direction perpendicular to the substrate 110, so that the raised structure 131 can improve the organic layer removal rate in the undesigned organic layer area by raising the photoresist layer during the organic layer (including the planarization layer and the pixel definition layer) forming process, thereby achieving complete removal of the excess organic layer.

[0043] According to some embodiments of the present application, the composition of the protrusion structure is not particularly limited, for example, Figure 6The peripheral area further includes a second interlayer dielectric layer, the second interlayer dielectric layer is located on the side of the interlayer dielectric layer 130 away from the substrate 110, the raised structure 132 is formed by the second interlayer dielectric layer, the second interlayer dielectric layer is located between the interlayer dielectric layer 130 and the source / drain metal layer 140, the surface of the raised structure 132 close to the substrate 110 is flush with the surface of the first retaining wall close to the substrate 110 (the surface of the planarization layer 10 close to the substrate), the raised structure 132 and the second retaining wall are spaced apart in a direction perpendicular to the substrate 110, for example, the raised structure 132 and the second retaining wall are spaced apart in a direction perpendicular to the substrate 110. The source / drain metal layer 140 and the anode layer 210 can be spaced apart in a direction perpendicular to the substrate 110, so that the raised structure 132 can improve the organic layer removal rate in the undesigned organic layer area by raising the photoresist layer during the organic layer forming process, thereby achieving complete removal of excess organic layer. Compared with forming the raised structure 131 through the interlayer dielectric layer 130, forming the raised structure 132 through the second interlayer dielectric layer makes the photoresist layer closer to the exposure light source during the organic layer (including the planarization layer and the pixel definition layer) forming process, the photoresist layer removal effect is better, and the subsequent organic layer removal rate in the undesigned organic layer area is also higher.

[0044] According to some embodiments of the present application, the thickness of the second interlayer dielectric layer is not particularly limited. For example, the second interlayer dielectric layer can be kept consistent with the interlayer dielectric layer, so that the second urban construction dielectric layer can be formed by using the interlayer dielectric layer forming process, and then the second interlayer dielectric layer can be patterned in the peripheral area to form the protruding structure 132.

[0045] According to some embodiments of the present application, reference Figure 1 and Figure 6 When the surface of the raised structure close to the substrate 110 is flush with the surface of the first barrier wall close to the substrate 110 (the surface of the planarization layer 10 close to the substrate), the anode layer 210 and the source-drain metal layer 140 in the peripheral area 2 away from the substrate 110 have a raised portion similar to the shape of the raised structure at the corresponding position where the raised structure is provided, and the raised direction of the raised portion is in the direction away from the substrate, that is, the anode layer 210 and the source-drain metal layer 140 located in the peripheral area are serrated film layers.

[0046] According to some embodiments of the present application, the composition of the raised structure is not particularly limited. For example, the raised structure may include an anode layer, and the surface of the raised structure close to the substrate is flush with the surface of the second retaining wall close to the substrate (the surface of the pixel defining layer close to the substrate). In this way, the raised structure can improve the organic layer removal rate in the undesigned organic layer area by raising the photoresist layer during the organic layer (including the pixel defining layer) forming process, thereby achieving complete removal of excess organic layer.

[0047] According to some embodiments of the present application, the locations of the retaining walls and the protruding structures are not particularly restricted. As long as the retaining walls and the protruding structures are adjacent to the display area and the non-display area, the retaining walls and the protruding structures can be arranged. For example, the peripheral area can be the area between the control pad area and the display area; the peripheral area can also be the area between the perforated area and the display area of ​​the perforated screen display device; the peripheral area can also be arranged around the display area or be located on one side or several sides of the display area.

[0048] According to some embodiments of the present application, reference Figure 1 and Figure 6 The anode layer 210 can be partially overlapped on the planarization layer 10 of the first retaining wall, thereby enhancing the stress between the film layers and playing a certain packaging role.

[0049] In another aspect of the present application, a display device is provided, which includes the aforementioned display substrate. Thus, the display device has all the features and advantages of the aforementioned display substrate, which will not be described in detail here.

[0050] In the description of this application, it should be understood that the terms "height", "thickness", "up", "down", "left", "right", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0051] Unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. All patents and publications referred to in this application are incorporated herein by reference in their entirety. The terms "comprising" or "including" are open-ended expressions, meaning that they include the contents specified in this application but do not exclude contents elsewhere.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "another embodiment" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are mutually inconsistent. In addition, it should be noted that in this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0053] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A display substrate, characterized in that: include: A substrate having a display area and a peripheral area, wherein the display area has an organic light-emitting device, and the peripheral area includes at least one retaining wall. The substrate further has an encapsulation structure and a protrusion structure, wherein the encapsulation structure is configured to seal the organic light-emitting device on the substrate, and the at least one protrusion structure is located in at least one of the following areas: The retaining wall is close to a side of the display area; Between two adjacent retaining walls, and The retaining wall is away from the side of the display area, The retaining wall includes an organic layer, the organic layer includes at least one of a pixel defining layer and a planarization layer, the orthographic projection of the protruding structure on the substrate does not overlap with the orthographic projection of the organic layer on the substrate, and the protruding structure is an insulating material on the side of the encapsulation structure facing the substrate; The display area is provided with a gate layer, an interlayer dielectric layer, a source / drain metal layer, the planarization layer, an anode layer, and the pixel defining layer stacked in sequence, the retaining wall includes a first retaining wall and a second retaining wall, the first retaining wall is located on a side of the second retaining wall away from the display area, and the height of the first retaining wall is greater than the height of the second retaining wall; The raised structure is formed integrally with the interlayer dielectric layer, the surface of the raised structure close to the substrate is flush with the surface of the first retaining wall close to the substrate, the raised structure and the second retaining wall are spaced apart in a direction perpendicular to the substrate, and the raised structure improves the organic layer removal rate in the area where the organic layer is not designed by raising the photoresist layer during the organic layer forming process.

2. The display substrate according to claim 1, wherein: The peripheral area includes one retaining wall and a plurality of protruding structures, and the plurality of protruding structures are located between the retaining wall and the display area.

3. The display substrate according to claim 1, wherein The peripheral area includes a plurality of retaining walls and a plurality of protruding structures, and both sides of each retaining wall have adjacent protruding structures.

4. The display substrate according to claim 1, wherein The organic layer of the first barrier wall includes the planarization layer and the pixel defining layer which are sequentially stacked.

5. The display substrate according to claim 1, wherein The organic layer of the second barrier wall includes the pixel defining layer.

6. The display substrate according to claim 1, wherein: The peripheral area further includes a second interlayer dielectric layer, which is located between the interlayer dielectric layer and the source / drain metal layer. The raised structure is formed by the second interlayer dielectric layer. The surface of the raised structure close to the substrate is flush with the surface of the first retaining wall close to the substrate. The raised structure and the second retaining wall are spaced apart in a direction perpendicular to the substrate.

7. The display substrate according to claim 1 or 6, characterized in that: The anode layer and the source / drain metal layer located on the side of the protruding structure away from the substrate both have a protruding portion facing the side away from the substrate.

8. The display substrate according to claim 4 or 5, characterized in that: The protruding structure includes the anode layer, and a surface of the protruding structure close to the substrate is flush with a surface of the second retaining wall close to the substrate.

9. A display device, characterized in that: The display device comprises the display substrate according to any one of claims 1 to 8.

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