Preparation method of display panel, display panel and display device

Abstract

The invention provides a preparation method of a display panel, the display panel and a display device.The display panel comprises a substrate, a display area and a frame area, the display area and the frame area are located on one side of the substrate, the frame area is located on the edge of the display area, the display area comprises a display function layer and a packaging layer which are sequentially stacked on the substrate, and the packaging layer is located between the display function layer and the packaging layer. The packaging layer comprises a first inorganic packaging layer, an organic packaging layer and a second inorganic packaging layer which are sequentially stacked in the direction away from the substrate, the frame area comprises an isolation dam, and the isolation dam and a part of film layers in the display function layer are arranged on the same layer. The first surface, far away from the substrate, of the isolation dam is provided with a concave part. Compared with the prior art, the storage space of the organic packaging material in the frame area is increased through the sunken part, the organic packaging material can be prevented from overflowing to the side, away from the display area, of the isolation dam, the packaging effect at the position of the frame area is improved, and the reliability of the frame area is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and more specifically, to a method for manufacturing a display panel, a display panel, and a display device. Background Art

[0002] Flexible displays are becoming an important development direction for future smart terminal devices due to their thin, light and bendable characteristics. OLED technology, especially OLED display panels based on flexible substrates, has significant advantages in achieving bendable displays with smaller bending radius due to its self-luminous characteristics, and has therefore received extensive attention and research.

[0003] In the manufacturing process of flexible OLED display panels, encapsulation technology is crucial, as it is directly related to the life and stability of display devices. Currently, thin-film encapsulation technology is one of the most commonly used encapsulation methods for flexible display products. This technology forms a multi-layer encapsulation layer by sequentially depositing inorganic layers and organic layers on the display element and its control circuit area to effectively block moisture and oxygen and protect the internal devices from damage. When organic materials naturally level, they are prone to overflowing the pre-designed isolation structure, affecting the encapsulation effect. Summary of the invention

[0004] The purpose of the present disclosure is to provide a method for manufacturing a display panel, a display panel and a display device, so as to solve the technical problem that overflow of organic packaging materials leads to reduced packaging reliability in the frame area.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] In a first aspect of the present disclosure, a display panel is provided, which includes a base substrate, a display area and a frame area located on one side of the base substrate, the frame area is located at the edge of the display area, the display area includes a display function layer and an encapsulation layer stacked in sequence on the base substrate, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam, the isolation dam is arranged in the same layer as some film layers in the display function layer, and a recessed portion is arranged on the first surface of the isolation dam away from the base substrate.

[0007] Optionally, the display function layer includes at least a first planarization layer, a second planarization layer and an isolation column layer stacked in a direction away from the base substrate, and the isolation dam includes at least two isolation layers stacked in sequence in a direction away from the base substrate, and any isolation layer of the at least two isolation layers is arranged on the same layer as one of the first planarization layer, the second planarization layer and the isolation column layer.

[0008] Optionally, the display function layer includes at least a first planarization layer, a second planarization layer, a third planarization layer and an isolation column layer stacked in a direction away from the base substrate, and the isolation dam includes at least two isolation layers stacked in sequence in a direction away from the base substrate, and any of the at least two isolation layers is arranged on the same layer as one of the first planarization layer, the second planarization layer, the third planarization layer and the isolation column layer.

[0009] Optionally, the isolation dam comprises a first isolation layer, a second isolation layer and a third isolation layer stacked in sequence in a direction away from the substrate;

[0010] The first isolation layer is disposed in the same layer as the first planarization layer, the second isolation layer is disposed in the same layer as the second planarization layer, and the third isolation layer is disposed in the same layer as the isolation column layer; or

[0011] The first isolation layer and the second planarization layer are arranged in the same layer, the second isolation layer and the third planarization layer are arranged in the same layer, and the third isolation layer and the isolation column layer are arranged in the same layer.

[0012] Optionally, the recessed portion is a groove structure.

[0013] Optionally, the isolation dam comprises a first isolation layer, a second isolation layer and a third isolation layer stacked in sequence in a direction away from the substrate;

[0014] The groove structure penetrates the third isolation layer;

[0015] The groove structure penetrates the third isolation layer and the second isolation layer; or

[0016] The groove structure penetrates the first isolation layer, the second isolation layer and the third isolation layer.

[0017] Optionally, in the direction from the frame area to the display area, the recessed portion includes at least two groove structures.

[0018] Optionally, the isolation dam further includes a first isolation wall located on a side of the groove structure close to the display area and a second isolation wall located on a side of the groove structure away from the display area, and a width of the first isolation wall and the second isolation wall in a direction from the border area toward the display area is less than or equal to a width of the groove structure.

[0019] Optionally, in the depth direction of the groove structure, the width of the groove structure decreases as the depth increases; and / or

[0020] In a direction perpendicular to the base substrate, a height of the second isolation wall is greater than or equal to a height of the first isolation wall.

[0021] Optionally, the recessed portion is a step structure, and a sidewall slope of the step structure is located on a side of the isolation dam close to the display area.

[0022] Optionally, the isolation dam includes a first isolation layer, a second isolation layer and a third isolation layer stacked in sequence in a direction away from the base substrate, and the step structure includes a first step and / or a second step, the first step is a step structure formed by the second isolation layer and the first isolation layer near the edge of the display area, and the second step is a step structure formed by the third isolation layer and the second isolation layer near the edge of the display area.

[0023] Optionally, the border area further includes a first isolation column and a second isolation column, the first isolation column is arranged on a side of the isolation dam close to the display area, and the second isolation column is arranged on a side of the isolation dam away from the display area, and the height of the isolation dam is greater than the heights of the first isolation column and the second isolation column.

[0024] Optionally, the display function layer further includes at least two source-drain metal layers stacked in a direction away from the base substrate, and the first isolation column and the second isolation column are arranged in the same layer as at least one of the at least two source-drain metal layers.

[0025] A second aspect of the present disclosure provides a method for preparing a display panel, comprising the following steps:

[0026] providing a substrate base plate;

[0027] A display area and a frame area are formed on one side of the base substrate, the frame area is located at the edge of the display area, the display area includes a display function layer and an encapsulation layer stacked in sequence on the base substrate, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam, the isolation dam is arranged in the same layer as some film layers in the display function layer, and a recessed portion is formed on the first surface of the isolation dam away from the base substrate.

[0028] A third aspect of the present disclosure provides a display device, comprising the display panel as described above.

[0029] The beneficial effects of the present disclosure are as follows:

[0030] The display panel of the disclosed embodiment is provided with an isolation dam in the border area, and a recessed portion is provided on the first surface of the isolation dam away from the base substrate. When the organic encapsulation layer is subsequently prepared, the organic encapsulation material will preferentially flow into the recessed structure during the process of flowing from the display area into the border area. The recessed structure increases the storage space for the organic encapsulation material in the border area, thereby preventing the organic encapsulation material from overflowing to the side of the isolation dam away from the display area, thereby improving the encapsulation effect at the border area and improving the reliability of the border area. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The specific implementation methods of the present disclosure are further described in detail below with reference to the accompanying drawings.

[0032] Figure 1 A schematic diagram of a planar structure of a display panel provided in an embodiment of the present disclosure;

[0033] Figure 2 A schematic diagram of a product in which the encapsulation of the hole frame in the display area fails in the related art;

[0034] Figure 3 A schematic diagram of a film layer structure of a display panel provided in an embodiment of the present disclosure;

[0035] Figure 4 A schematic diagram of the distribution of isolation columns and isolation dams in the second border area provided in an embodiment of the present disclosure;

[0036] Figure 5 A schematic diagram of a structure in which a groove structure provided in an embodiment of the present disclosure penetrates a third isolation layer;

[0037] Figure 6 A schematic diagram of a structure in which a groove structure provided in an embodiment of the present disclosure penetrates a third isolation layer and a second isolation layer;

[0038] Figure 7 A schematic diagram of a structure in which a groove structure provided in an embodiment of the present disclosure penetrates a third isolation layer, a second isolation layer and a first isolation layer;

[0039] Figure 8 Another schematic diagram of a structure in which a groove structure provided in an embodiment of the present disclosure penetrates a third isolation layer and a second isolation layer;

[0040] Fig. 9 Another structural schematic diagram of a groove structure provided in an embodiment of the present disclosure that penetrates the third isolation layer, the second isolation layer and the first isolation layer;

[0041] Fig.10 A schematic diagram of a step structure provided in an embodiment of the present disclosure;

[0042] Fig.11A schematic diagram of another structure of the step structure provided in the embodiment of the present disclosure;

[0043] Fig.12 A schematic diagram of a structure of a recessed portion provided in an embodiment of the present disclosure;

[0044] Fig.13 A schematic diagram of another structure of the recessed portion provided in the embodiment of the present disclosure;

[0045] Fig.14 A schematic diagram of another film layer structure of a display panel provided in an embodiment of the present disclosure;

[0046] Fig.15 A flow chart of a method for preparing a display panel provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0048] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0049] In the related art, the inkjet printing process (Ink Jet Printing, referred to as IJP) has shown great potential in the preparation of the organic encapsulation layer of flexible OLED display panels due to its advantages of high precision, high material utilization rate and easy patterning. However, in practical applications, the IJP process also faces some challenges, especially when using Ink materials with lower viscosity. After the material drips onto the surface of the substrate, it is easy to increase the droplet size during the natural leveling process due to the influence of surface tension and substrate structure, which leads to the overflow of Ink to the isolation structure, such as the isolation column PS or the isolation dam Dam. Such overflow not only affects the uniformity and integrity of the encapsulation layer, but may also cause edge reliability failure, that is, the sealing performance of the encapsulation layer in the edge area is reduced, increasing the risk of moisture and oxygen penetration, and ultimately affecting the reliability and service life of the display panel.

[0050] Please refer to Figure 1 , Figure 1 A schematic plan view of a display panel provided in an embodiment of the present disclosure is shown in FIG. Figure 1 As shown, for a display panel with an optical sensor under the screen, the display panel includes a display area A1 and a first frame area B1 surrounding the display area A1, and an opening H is provided in the display area A1, and a second frame area B2 is provided between the opening H and the display area A1. The second frame area B2 can also be understood as a hole frame, that is, the frame of the opening H. Among them, isolation structures such as PS or Dam are provided in the first frame area B1 and the second frame area B2 to define the edge of the encapsulation layer. When the organic encapsulation layer in the encapsulation layer is prepared by an inkjet printing process, the overflow of Ink to the outside of PS or Dam will cause the edge reliability of the encapsulation layer to fail, affecting the encapsulation effect, please refer to Figure 2 , Figure 2 This is a product diagram showing the failure of the hole frame encapsulation in the display area. Figure 2 D in the figure indicates the area where the package fails.

[0051] In order to solve the above technical problems, the present disclosure provides a method for manufacturing a display panel, a display panel and a display device. Figure 3 , Figure 3 A schematic diagram of the film layer structure of the display panel in the AA direction provided by the embodiment of the present disclosure, such as Figure 3As shown, the display panel includes a base substrate 11, a display area A1 located on one side of the base substrate 11, and a frame area, the frame area is located at the edge of the display area A1, the display area A1 includes a display function layer 12 and an encapsulation layer 13 stacked in sequence on the base substrate 11, the encapsulation layer 13 includes a first inorganic encapsulation layer 131, an organic encapsulation layer 132 and a second inorganic encapsulation layer 133 stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam 14, the isolation dam 14 is arranged in the same layer as part of the film layer in the display function layer 12, and a recessed portion is arranged on the first surface of the isolation dam 14 away from the base substrate 11.

[0052] like Figure 1 and Figure 3 As shown, the frame area in the embodiment of the present disclosure includes a first frame area B1 and a second frame area B2, and the display panel also includes an opening area C1, the opening area C1 is the area corresponding to the opening H, the first frame area B1 is the area surrounding the display area A1, the second frame area B2 is the area between the opening area C1 and the display area A1, that is, the hole frame, the display area A1, the first frame area B1, the second frame area B2 and the opening area C1 constitute the entire area of ​​the display panel. Among them, the frame area is located at the edge of the display area A1, which can be understood as: the first frame area B1 is located at the outer edge of the display area A1, and the second frame area B2 is located at the inner edge of the display area A1, that is, the edge of the opening H.

[0053] In the embodiment of the present disclosure, the border area includes an isolation dam 14, and the first border area B1 may include the isolation dam 14, or the second border area B2 may include the isolation dam 14, or both the first border area B1 and the second border area B2 may include the isolation dam 14. That is, the isolation dam 14 in the embodiment of the present disclosure can be used for both the first border area B1 and the second border area B2. Since the isolation dams 14 in the border areas at different positions have the same structure and the same principle for improving the overflow of organic materials in the IJP process, the specific implementation principle of the isolation dam 14 is described in the embodiment of the present disclosure only by taking the second border area B2 as an example.

[0054] Optionally, the display function layer 12 is used to realize the display function of the display panel, which includes but is not limited to a driving circuit layer 121, a first electrode layer 122, a pixel defining layer 123, a light-emitting device layer 124, an isolation column layer 125 and a second electrode layer 126 stacked in sequence on the base substrate 11.

[0055] Among them, each film layer in the display function layer 12 is formed of different materials according to the function of the film layer, such as metal materials, inorganic materials or organic materials, etc. In the embodiment of the present disclosure, the isolation dam 14 is an isolation structure formed of organic materials, which may include one, two or more layers of organic material layers. The isolation dam 14 is arranged in the same layer with some film layers in the display function layer 12, which can be understood as: each organic material layer in the isolation dam 14 is arranged in the same layer with one of the organic material layers in the display function layer 12. In the present disclosure, unless otherwise specified, the term "arranged in the same layer" used means that two layers, parts, components, elements or parts can be formed by the same preparation process (such as composition process, etc.), and these two layers, parts, components, elements or parts are generally formed of the same material. For example, two or more functional layers are arranged in the same layer, which means that these functional layers arranged in the same layer can be formed using the same material layer and the same preparation process, thereby simplifying the preparation process of the display substrate.

[0056] In the embodiment of the present disclosure, the first inorganic encapsulation layer 131 and the second inorganic encapsulation layer 133 can be formed by deposition and other processes using inorganic materials such as silicon nitride, silicon oxide, and silicon oxynitride. The organic encapsulation layer 132 can be formed by an inkjet printing process using organic materials such as polyimide (PI) and epoxy resin. The first inorganic encapsulation layer 131, the organic encapsulation layer 132, and the second inorganic encapsulation layer 133 are formed as a composite encapsulation layer in which inorganic materials and organic materials are staggered and stacked. The composite encapsulation layer can form multiple protections for the functional structure of the display panel and has a better encapsulation effect. It can be understood that the encapsulation layer 13 in the embodiment of the present disclosure is not limited to the above structure, and it can also include more layers, such as an inorganic encapsulation layer containing more than two layers, and an organic encapsulation layer containing more than one layer, and the number of inorganic layers is greater than the number of organic layers. Exemplarily, the encapsulation layer 13 can also be a five-layer structure, including an inorganic encapsulation layer, an organic encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer, and an inorganic encapsulation layer stacked in sequence.

[0057] Compared with the related art, the display panel of the embodiment of the present disclosure is provided with an isolation dam in the border area, and a recessed portion is provided on the first surface of the isolation dam away from the base substrate. When the organic encapsulation layer is subsequently prepared by an inkjet printing process, the organic encapsulation material will preferentially flow into the recessed structure during the process of flowing from the display area to the border area. The recessed structure increases the storage space for the organic encapsulation material in the border area, thereby preventing the organic encapsulation material from overflowing to the side of the isolation dam away from the display area, thereby improving the encapsulation effect at the border area and improving the reliability of the border area.

[0058] In a possible implementation, the border area also includes an isolation column 15, the isolation column 15 includes a first isolation column 151 and a second isolation column 152, the first isolation column 151 is arranged on the side of the isolation dam 14 close to the display area A1, and the second isolation column 152 is arranged on the side of the isolation dam 14 away from the display area A1, and the height of the isolation dam 14 is greater than the height of the first isolation column 151 and the second isolation column 152.

[0059] The height of the isolation dam 14 refers to the height of the isolation dam 14 in the direction perpendicular to the base substrate 11, that is, the vertical distance between the surface of the isolation dam 14 away from the base substrate 11 and the base substrate 11. Similarly, the height of the first isolation column 151 and the second isolation column 152 also refers to the height of the first isolation column 151 and the second isolation column 152 in the direction perpendicular to the base substrate 11. The height of the isolation dam 14 is greater than the height of the first isolation column 151 and the second isolation column 152, which means that the height of the isolation dam 14 is greater than the height of the first isolation dam 1510, and the height of the isolation dam 14 is greater than the height of the second isolation dam 1520.

[0060] The first isolation column 151 is located on the side of the isolation dam 14 close to the display area A1, which also means that the first isolation column 151 is arranged between the isolation dam 14 and the display area A1, and can also be understood as the first isolation column 151 is an inner isolation column. Correspondingly, the second isolation column 152 is located on the side of the isolation dam 14 away from the display area A1, and can also be understood as the second isolation column 152 is an outer isolation column. For the second frame area B2, the second isolation column 152 can also be understood as being located between the isolation dam 14 and the opening area C1.

[0061] In the embodiment of the present disclosure, in the frame area, the first isolation column 151, the isolation dam 14, and the second isolation column 152 are sequentially arranged in the direction away from the display area A1, and the height of the isolation dam 14 is greater than the height of the first isolation column 151 and the second isolation column 152. In this arrangement, on the one hand, the height of the isolation dam 14 is designed to be higher than the first isolation column 151 and the second isolation column 152, which can form an effective barrier. During the filling process of the organic encapsulation material, this higher isolation dam 14 can prevent the organic encapsulation material from overflowing to the outside of the frame area due to flow or pressure; on the other hand, the heights of the first isolation column 151 and the second isolation column 152 are relatively low, and they can guide the flow path of the organic encapsulation material in the frame area, ensuring that the material can be evenly and orderly filled into the space between the display area and the frame area, and this design also helps to reduce bubbles or gaps caused by material flow; in addition, effective overflow blocking and optimized material flow path can ensure that the encapsulation between the display area A1 and the frame area is tighter and more uniform, which helps to improve the reliability of the product.

[0062] Optionally, the number of the first isolation columns 151 and the number of the second isolation columns 152 are both multiple. For the first frame area B1, multiple first isolation columns 151 are distributed in an array to form an inner circle of isolation columns surrounding the display area A1, and multiple second isolation columns 152 are distributed in an array to form an outer circle of isolation columns surrounding the display area A1, and the isolation dam 14 is arranged between the inner circle isolation columns and the outer circle isolation columns. For the second frame area B2, multiple first isolation columns 151 are distributed in an array to form an inner circle of isolation columns surrounding the opening area C1, and multiple second isolation columns 152 are distributed in an array to form an outer circle of isolation columns surrounding the opening area C1, and the isolation dam 14 is arranged between the inner circle isolation columns and the outer circle isolation columns. The inside and outside here are relative to the display area, that is, relatively close to the display area is represented as inside, and relatively far from the display area is represented as outside.

[0063] Optionally, the number of the second isolation columns 152 is greater than the number of the first isolation columns 151. Figure 3 to Figure 4 As shown, in the second frame area B2, the first isolation column 151 forms an inner circle isolation column, the second isolation column 1530 forms three outer circles of isolation columns, and the isolation dam 14 is arranged between the inner circle isolation column and the outer circle isolation column. Figure 4 The multiple circular lines in the second border area B2 can be used to illustrate the distribution of the isolation columns 15 and the isolation dams 14 around the opening area C1. In the embodiment of the present disclosure, a more rigorous barrier can be formed by combining the multiple circles of second isolation columns 152 with the higher isolation dams 14, which helps to more effectively prevent the overflow of organic packaging materials during the filling process, ensuring the smooth progress of the packaging process and the reliability of the packaging quality.

[0064] In a possible implementation, the first isolation column 151 and the second isolation column 152 are metal isolation columns, which are disposed in the same layer as the source and drain metal layer in the driving circuit layer 121 .

[0065] Optionally, the display function layer further includes at least two source-drain metal layers stacked in a direction away from the base substrate 11 , and the first isolation column 151 and the second isolation column 152 are arranged in the same layer as at least one of the at least two source-drain metal layers.

[0066] Exemplarily, when the display function layer includes two source-drain metal layers, such as a first source-drain metal layer SD1 and a second source-drain metal layer SD2, the first isolation column 151 and the second isolation column 152 can be arranged on the same layer as the first source-drain metal layer SD1, or on the same layer as the second source-drain metal layer SD2, or the first isolation column 151 and the second isolation column 152 have a double-layer structure, in which one layer is arranged on the same layer as the first source-drain metal layer SD1, and the other layer is arranged on the same layer as the second source-drain metal layer SD2.

[0067] Exemplarily, when the display function layer includes three source-drain metal layers, such as the first source-drain metal layer SD1, the second source-drain metal layer SD2, and the third source-drain metal layer SD3, the first isolation column 151 and the second isolation column 152 may be disposed in the same layer as the first source-drain metal layer SD1, or in the same layer as the second source-drain metal layer SD2, or in the same layer as the third source-drain metal layer SD3. Alternatively, the first isolation column 151 and the second isolation column 152 are double-layer or triple-layer structures. For the double-layer structure, the first isolation column 151 and the second isolation column 152 may be disposed in the same layer as any two layers of the first source-drain metal layer SD1, the second source-drain metal layer SD2, and the third source-drain metal layer SD3. For the triple-layer structure, they are disposed in the same layer as each source-drain metal layer.

[0068] In a specific example, the first isolation column 151 and the second isolation column 152 are disposed in the same layer as the first source-drain metal layer SD1 close to the base substrate 11 .

[0069] Optionally, the first isolation column 151 and the second isolation column 152 include a first metal layer, a second metal layer and a third metal layer stacked in sequence. Exemplarily, the first metal layer and the third metal layer are aluminum, and the second metal layer is titanium. In this case, the first isolation column 151 and the second isolation column 152 are a metal stacked structure of Ti-Al-Ti.

[0070] In the disclosed embodiment, the base substrate 11 may be a flexible substrate of materials such as polyimide (PI), polyethylene naphthalate (PEN), thermoplastic polyester (PET), or a rigid substrate of materials such as glass and quartz. The display panel may also include a barrier layer (Barrier) and a buffer layer (Buffer) located between the base substrate 11 and the driving circuit layer 110, and the barrier layer and the buffer layer may be formed on the entire surface of the base substrate 11. For example, the barrier layer may be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride, and the barrier layer is beneficial to blocking water and oxygen from entering the OLED formed later from the bottom. The buffer layer may also be made of inorganic insulating materials such as silicon oxide, silicon nitride, or silicon oxynitride, and the buffer layer is beneficial to the quality of subsequent material deposition.

[0071] The driving circuit layer 121 is also called a thin film transistor (TFT) layer, which may include an active layer (Active) formed on the buffer layer by a patterning process, a gate insulating layer (GI) formed on the active layer by deposition or the like, a gate (Gate) of a thin film transistor formed on the gate insulating layer by a patterning process, a dielectric layer (ILD) formed on the gate by deposition or the like, a source-drain metal layer formed on the dielectric layer, and a planar layer (PLN) covering the source-drain metal layer and the exposed dielectric layer, wherein the source-drain metal layer forms a source (Source) and a drain (Drain) of the thin film transistor, for example, the source is electrically connected to the active layer through a dielectric layer via. The active layer may be made of materials such as polysilicon and metal oxides, the gate insulating layer may be made of inorganic insulating materials such as silicon oxide, silicon nitride or silicon oxynitride, the dielectric layer may be made of inorganic insulating materials such as silicon oxide, silicon nitride or silicon oxynitride, the gate material includes metals or alloy materials such as aluminum, titanium, and cobalt, and the planar layer is, for example, an organic material. In specific implementation, the driving circuit layer 121 can be a double Gate layer structure, a double SD (i.e., two source and drain metal layers) structure, a triple SD (i.e., three source and drain metal layers) structure, etc. The embodiment of the present disclosure does not limit the specific film layer structure of the driving circuit layer 121.

[0072] The first electrode layer 122 is, for example, an anode layer, which includes a plurality of anodes. The anode layer may be made of metal oxides such as ITO and IZO or metals such as Ag, Al, Mo or their alloy materials. The anode may be electrically connected to the drain through a via hole opened in the planar layer.

[0073] The pixel defining layer 123 may be formed by a patterning process, and surrounds the anode. For example, the material of the pixel defining layer 123 may include organic insulating materials such as negative photoresist, polyimide, and epoxy resin. Specifically, the pixel defining layer 120 includes a plurality of pixel openings, and the anode is disposed in the pixel openings.

[0074] The light-emitting device layer 124 is formed on the anode exposed by the pixel opening opened by the pixel defining layer 123. The light-emitting device layer 124 includes a light-emitting layer (EML), and the light-emitting layers of sub-pixels of different colors are different. For example, the red sub-pixel includes a red light-emitting layer, the green sub-pixel includes a green light-emitting layer, and the blue sub-pixel includes a blue light-emitting layer. The light-emitting device layer 124 may also include an auxiliary light-emitting layer that helps the light-emitting layer emit light. The auxiliary light-emitting layer, for example, includes one or more film layers of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EIL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). The light-emitting layer and the auxiliary light-emitting layer are, for example, organic material layers.

[0075] The isolation column layer 125 includes a plurality of isolation columns, which are located between adjacent pixel openings and on the side of the pixel defining layer 123 away from the base substrate 11. In a direction perpendicular to the display panel, the isolation column layer 125 is located between the pixel defining layer 123 and the second electrode layer 126, that is, the second electrode layer 126 covers the isolation column layer 125.

[0076] The second electrode layer 126 is, for example, a cathode, which is formed on the entire surface of the display panel, covering the light-emitting device layer 124, the pixel defining layer 123 and the isolation column layer 125. The material of the cathode may include metals such as Mg, Ca, Li or Al or their alloys, or metal oxides such as IZO and ZTO, or organic materials with conductive properties such as PEDOT / PSS (poly 3,4-ethylenedioxythiophene / polystyrene sulfonate).

[0077] In a specific implementation, the driving circuit layer 121 may be first prepared on the base substrate 11, and then the pixel defining layer 123 may be prepared on the driving circuit layer 121, and then the isolation column layer 125 may be prepared on the pixel defining layer 123, and then the first electrode layer 122, the light emitting device layer 124, and the second electrode layer 126 may be prepared in sequence. In addition, the first electrode layer 122 may also be formed before the pixel defining layer 123 is prepared. The embodiments of the present disclosure are not limited thereto.

[0078] Optionally, for a display panel with a double-layer SD structure, the display function layer includes at least a first planarization layer PLN1, a second planarization layer PLN2, and an isolation column layer PS stacked in a direction away from the base substrate, and the isolation dam 14 includes at least two isolation layers stacked in sequence in a direction away from the base substrate 11, and any of the at least two isolation layers is arranged on the same layer as one of the first planarization layer PLN1, the second planarization layer PLN2, and the isolation column layer PS.

[0079] Exemplarily, the isolation dam 14 includes two isolation layers, one of which is disposed at the same layer as the first planarization layer PLN1 , and the other is disposed at the same layer as the second planarization layer PLN2 .

[0080] Exemplarily, the isolation dam 14 includes two isolation layers, one of which is disposed at the same layer as the first planarization layer PLN1 , and the other is disposed at the same layer as the isolation column layer PS.

[0081] Exemplarily, the isolation dam 14 includes two isolation layers, one of which is disposed at the same layer as the second planarization layer PLN2 , and the other is disposed at the same layer as the isolation column layer PS.

[0082] Exemplarily, the isolation dam 14 includes three isolation layers, the first layer is arranged at the same layer as the first planarization layer PLN1 , the second layer is arranged at the same layer as the second planarization layer PLN2 , and the third layer is arranged at the same layer as the isolation column layer PS.

[0083] Optionally, for a display panel with a three-layer SD structure, the display function layer includes at least a first planarization layer PLN1, a second planarization layer PLN2, a third planarization layer PLN3 and an isolation column layer PS stacked in a direction away from the base substrate, and the isolation dam 14 includes at least two isolation layers stacked in sequence in a direction away from the base substrate 10, and any of the at least two isolation layers is arranged on the same layer as one of the first planarization layer PLN1, the second planarization layer PLN2, the third planarization layer PLN3 and the isolation column layer PS.

[0084] Exemplarily, the isolation dam 14 includes two isolation layers, one isolation layer can be arranged on the same layer as one of the first planarization layer PLN1, the second planarization layer PLN2, the third planarization layer PLN3 and the isolation column layer PS, and the other isolation layer is arranged on the same layer as the other one of the first planarization layer PLN1, the second planarization layer PLN2, the third planarization layer PLN3 and the isolation column layer PS. For example, the film layer combination of the isolation dam 14 can be PLN1+PLN2, PLN1+PLN3, PLN1+PS, PLN2+PLN3, PLN2+PS, PLN3+PS and the like.

[0085] Exemplarily, the isolation dam 14 includes three isolation layers, and the combinations thereof may be PLN1+PLN2+PLN3, PLN1+PLN2+PS, PLN1+PLN3+PS, and PLN2+PLN3+PS.

[0086] Exemplarily, the isolation board 14 includes four isolation layers, the first layer is arranged on the same layer with the first planarization layer PLN1, the second layer is arranged on the same layer with the second planarization layer PLN2, the third layer is arranged on the same layer with the third planarization layer PLN3, and the fourth layer is arranged on the same layer with the isolation column layer PS.

[0087] In a specific example, the driving circuit layer 121 is a structure of three source and drain metal layers, such as Figure 3 As shown, the driving circuit layer 121 includes an active layer 1211 stacked in sequence along a direction away from the base substrate 11, a first gate insulating layer (GI1) 1212 covering the active layer 1211, a first gate (Gate1) 1213 formed on the first gate insulating layer 1212, a second gate insulating layer (GI2) 1214 covering the first gate (Gate1) 1213, a second gate (Gate2) 1215 formed on the second gate insulating layer 1214, an interlayer insulating layer (ILD) 1216 covering the second gate 1215, and a first gate (Gate1) 1213 formed on the first gate insulating layer 1213. A first source-drain metal layer 1217 on layer 1216, a first planarization layer (PLN1) 1218 covering the first source-drain metal layer 1217 and the interlayer insulating layer 1216, a second source-drain metal layer 1219 formed on the first planarization layer 1218, a second planarization layer (PLN2) 1220 covering the second source-drain metal layer 1219 and the first planarization layer 1218, a third source-drain metal layer 1221 formed on the second planarization layer (PLN3) 1220, and a third planarization layer 1222 covering the third source-drain metal layer 1221 and the second planarization layer 1220.

[0088] In a possible implementation, the isolation dam 14 includes a first isolation layer 141, a second isolation layer 142, and a third isolation layer 143 stacked in sequence in a direction away from the base substrate 11, and the display function layer 12 includes at least a first planarization layer 1218, a second planarization layer 1220, a third planarization layer 1222, and an isolation column layer 125 stacked in a direction away from the base substrate 11, the first isolation layer 141 and the second planarization layer 1220 are arranged in the same layer, the second isolation layer 142 and the third planarization layer 1222 are arranged in the same layer, and the third isolation layer 143 and the isolation column layer 125 are arranged in the same layer. Correspondingly, the first isolation column 151 and the second isolation column 152 are arranged in the same layer as the first source and drain metal layer 1217.

[0089] It can be understood that the embodiment of the present disclosure takes a display panel with a three-layer SD structure as an example, and describes an isolation dam with a three-layer structure formed by the preparation process of the second planarization layer, the third planarization layer and the isolation column layer in the display area as an example. In specific implementation, the specific film layer structure of the display area of ​​the display panel is not limited, as long as the display area has a plurality of organic layers stacked in a direction away from the base substrate, and the plurality of organic layers are used to form the isolation dam in the embodiment of the present disclosure in the same layer in the border area. For example, for a display panel with a double SD structure, the isolation dam 14 includes a first isolation layer 141, a second isolation layer 142 and a third isolation layer 143 stacked in sequence in a direction away from the base substrate 11, the first isolation layer 141 is arranged on the same layer as the first planarization layer, the second isolation layer 142 is arranged on the same layer as the second planarization layer, and the third isolation layer 143 is arranged on the same layer as the isolation column layer.

[0090] In a possible implementation, the recessed portion is a groove structure 140a. In a specific implementation, a groove is provided on the upper surface of the isolation dam 14, that is, the upper surface of the isolation dam 14 away from the base substrate 11, so as to achieve a drainage effect on the organic encapsulation material and prevent the organic encapsulation material from overflowing to the outside of the isolation dam 14, that is, the side of the isolation dam 14 away from the display area A1.

[0091] Optionally, the groove structure penetrates the third isolation layer, and the depth of the groove structure is equal to the thickness of the third isolation layer. Figure 5 As shown, when the third isolation layer 143 and the isolation column layer 125 are disposed at the same layer, the depth of the groove structure 140 a is the thickness of the isolation column layer 125 , that is, the height of the isolation column layer 125 .

[0092] Optionally, the groove structure penetrates the third isolation layer and the second isolation layer, and the depth of the groove structure is the sum of the thickness of the third isolation layer and the second isolation layer. Figure 6 and Figure 8 As shown, when the second isolation layer 142 and the third planarization layer 1222 are arranged on the same layer, and the third isolation layer 143 and the isolation column layer 125 are arranged on the same layer, at this time, the depth of the groove structure 140a is the sum of the thickness of the isolation column layer 125 and the third planarization layer 1222, that is, the sum of the heights of the isolation column layers 125 and the isolation column layers 125.

[0093] Optionally, the groove structure penetrates the first isolation layer, the second isolation layer and the third isolation layer, and the depth of the groove structure is the sum of the thicknesses of the first isolation layer, the second isolation layer and the third isolation layer. Figure 7 and Fig. 9As shown, when the first isolation layer 141 and the second planarization layer 1220 are arranged on the same layer, the second isolation layer 142 and the third planarization layer 1222 are arranged on the same layer, and the third isolation layer 143 and the isolation column layer 125 are arranged on the same layer, at this time, the depth of the groove structure 140a is the sum of the thickness of the isolation column layer 125, the second planarization layer 1220 and the third planarization layer 1222.

[0094] It is understandable that the depth of the groove structure in the embodiment of the present disclosure can be selected according to specific scenarios such as the droplet size of the organic encapsulation material in the inkjet printing process and the width of the groove structure, and is not limited to the depth of the above example.

[0095] In the present disclosure, one groove structure may be provided on the isolation dam 14, or two or more groove structures may be provided. When two or more groove structures are provided, a larger storage space may be provided for the border area to accommodate the organic encapsulation material, thereby reducing the risk of the organic encapsulation material overflowing. It is understood that in a specific implementation, the number of groove structures needs to be adapted to the width of the isolation dam 14. According to the width of the isolation dam 14, one groove structure (single groove) or two grooves (double groove) may be provided.

[0096] In a possible implementation, in the direction from the opening area C1 to the display area A1, the recessed portion includes at least two groove structures 140a. Figure 3 As shown, when two or more groove structures 140a are provided, each groove structure 140a is sequentially distributed in the direction from the opening area C1 to the display area A1. Exemplarily, each groove structure is uniformly distributed in the direction from the opening area C1 to the display area A1.

[0097] In a possible implementation, the isolation dam 14 also includes a first isolation wall 14A located on the side of the groove structure 140a close to the display area A1 and a second isolation wall 14B located on the side of the groove structure 140a away from the display area A1, and the width of the first isolation wall 14A and the second isolation wall 14B in the direction from the border area toward the display area A1 is less than or equal to the width of the groove structure 140a.

[0098] The first isolation wall 14A can be understood as the portion of the isolation dam 14 on the side of the groove structure 140a close to the display area A1, and the second isolation wall 14B can be understood as the portion of the isolation dam 14 on the side of the groove structure 140a away from the display area A1. The first isolation wall 14A and the second isolation wall 14B define the groove structure 140a, and the distance between the first isolation wall 14A and the second isolation wall 14B is the width of the groove structure 140a. Specifically, as Figure 5 As shown, the width W1 of the groove structure refers to the direction from the frame area to the display area A1 (i.e. Figure 5 In the X direction as shown, the inner diameter of the groove and the width of the first isolation wall 14A are W2, that is, W1 is greater than or equal to W2.

[0099] Optionally, the width of the isolation dam 14 is 20 to 50 microns. Figure 3 As shown, when the width of the isolation dam 14 is 20 microns, two groove structures can be set on the isolation dam 14, and the width of each groove structure is greater than or equal to 4 microns, that is, the size of W1 is greater than or equal to 4 microns. In addition, a single groove structure can also be set, and the single groove structure has a larger width. For example, the width of the single groove structure is set to 8 microns, 10 microns, 12 microns, 16 microns, etc. In specific implementation, the width of the groove structure can be reasonably set according to the width of the isolation dam 14 and the number of groove structures.

[0100] In the disclosed embodiment, the width of the first isolation wall 14A is set to be smaller than the width of the groove structure 140a, and the width of the second isolation wall 14B is set to be smaller than the width of the groove structure 140a. Such a setting can realize that the groove structure 140a has a larger width, and the groove structure 140a can provide a larger storage space for the organic packaging material to prevent the organic packaging material from overflowing.

[0101] Optionally, in the depth direction of the groove structure 140a, the width of the groove structure 140a decreases as the depth increases. Figures 5 to 9 As shown, in the direction perpendicular to the base substrate 11, the closer to the base substrate 11, the smaller the width of the groove structure 140a, and the farther away from the base substrate 11, the larger the width of the groove structure 140a, which can also be understood as the groove structure being in an inverted trapezoidal shape or the groove structure including multiple inverted trapezoidal structures. In this way, on the one hand, the inverted trapezoidal design makes the bottom of the groove structure 140a wider, which can provide a larger space and better block the overflow of organic materials; on the other hand, the inverted trapezoidal groove design helps to increase the barrier to water vapor and oxygen, further enhance the packaging effect of the display panel, and improve the reliability and service life of the display panel.

[0102] In a possible implementation, the recessed portion is a step structure 140 b , and a sidewall slope of the step structure 140 b is located on a side of the isolation dam 14 close to the display area A1 .

[0103] In the embodiment of the present disclosure, the recessed portion is a step structure formed by the first isolation layer 141, the second isolation layer 142, and the third isolation layer 143 on the side surface close to the display area A1. In a specific implementation, the step structure 140b can be formed by controlling the position of the first isolation layer 141, the second isolation layer 142, and the third isolation layer 143 on the side surface close to the display area A1 in the X direction.

[0104] For example, Fig.10 As shown, the distance between the side surface of the third isolation layer 143 close to the display area A1 (assuming it is recorded as the third side surface) and the display area A1 is recorded as the first distance, and the distance between the side surface of the second isolation layer 142 close to the display area A1 (assuming it is recorded as the second side surface) and the display area A1 is recorded as the second distance. Since the first distance is greater than the second distance, the upper surface of the second isolation layer 142 away from the base substrate 11, the side surface of the third isolation layer 143 close to the display area A1, and the upper surface of the third isolation layer 143 away from the base substrate 11 together form a step structure facing the display area A1. When the organic encapsulation layer is subsequently prepared by an inkjet printing process, the organic encapsulation material will preferentially flow into the recessed portion of the step structure during the process of flowing from the display area to the frame area. Since the recessed portion increases the storage space for the organic encapsulation material in the frame area, the organic encapsulation material can be prevented from overflowing to the side of the isolation dam away from the display area, thereby improving the encapsulation effect at the position of the frame area and improving the reliability of the frame area.

[0105] Optionally, the step structure 140b includes a first step 1401b and / or a second step 1402b, the first step 1401b is a step structure formed by the second isolation layer 142 and the first isolation layer 141 near the edge of the display area A1, and the second step 1402b is a step structure formed by the third isolation layer 143 and the second isolation layer 142 near the edge of the display area A1.

[0106] Please refer to Fig.11 , Fig.11 The first isolation layer 141 , the second isolation layer 142 , and the third isolation layer 143 are distributed in a stepped manner on the side surfaces close to the display area A1 .

[0107] Compared with the related art, the embodiment of the present disclosure forms a stepped recess on the surface of the isolation dam. On the one hand, the stepped design increases the area of ​​the side surface, and there are multiple step edges, which can serve as additional resistance points to hinder the overflow of the organic encapsulation material. When the organic encapsulation material tries to cross the isolation dam, it needs to overcome more resistance, thereby reducing the possibility of overflow. On the other hand, the stepped design can also guide the flow direction of the organic encapsulation material to make it flow more orderly. By reasonably designing the height, width and inclination angle of the steps, it can be ensured that the organic encapsulation material will not splash or overflow due to excessive speed or sudden change in direction during the flow process.

[0108] Optionally, in a direction perpendicular to the base substrate 11 , a height of the second isolation wall 14B is greater than or equal to a height of the first isolation wall 14A.

[0109] In the disclosed embodiment, the first isolation wall 14A and the second isolation wall 14B are both part of the isolation dam 14, and the first isolation wall 14A is closer to the display area A1 than the second isolation wall 14B. In order to achieve a better blocking effect, the height of the second isolation wall 14B is set to be greater than or equal to the height of the first isolation wall 14A.

[0110] For example, Figures 5 to 9 As shown, the height of the first isolation wall 14A is equal to the height of the second isolation wall 14B.

[0111] For example, Fig.12 and Fig.13 As shown, the height of the first isolation wall 14A is less than the height of the second isolation wall 14B. The height of the first isolation wall 14A is the sum of the thicknesses of the first isolation layer 141 and the second isolation layer 142, and the height of the second isolation wall 14B is the sum of the thicknesses of the first isolation layer 141, the second isolation layer 142, and the third isolation layer 143. In this way, the first isolation wall 14A with a lower height can reduce the obstruction of the organic encapsulation material when flowing, so that the organic encapsulation material can flow into the recessed portion more smoothly, and the higher second isolation wall 14B can effectively prevent the organic encapsulation material from overflowing.

[0112] Optional, such as Fig.14 As shown, the display panel of the embodiment of the present disclosure also includes a touch layer 16, a polarizer 17 and a cover plate 18 stacked in sequence on the side of the encapsulation layer 13 away from the base substrate 11. Exemplarily, the touch layer 16 includes a first touch electrode layer (TMA), a first insulating layer (TLD), a second touch electrode layer (TMB) and a touch protection layer (TOC) stacked in sequence. Exemplarily, the cover plate 18 can be a glass cover plate (CG). In addition, the display panel can also include a sensor component Sensor located on the backlight side of the display panel.

[0113] Based on the same inventive concept, the second aspect of the present disclosure provides a method for preparing a display panel, such as Fig.15 As shown, the following steps are included:

[0114] Step S10, providing a substrate;

[0115] Step S20, forming a display area and a frame area on one side of the base substrate, the frame area is located at the edge of the display area, the display area includes a display function layer and an encapsulation layer stacked in sequence on the base substrate, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam, the isolation dam is arranged in the same layer as a part of the film layer in the display function layer, and a recessed portion is formed on the first surface of the isolation dam away from the base substrate.

[0116] The display panel in the implementation of the present disclosure may be an organic light-emitting diode (OLED) display panel. It is understandable that the display panel may be set to other types according to actual needs, for example, the display panel may also be a quantum dot light emitting diode (QLED) display panel or a micro light emitting diode (Micro LED) display panel.

[0117] Based on the same inventive concept, the third aspect of the present disclosure provides a display device, including the display panel as described above. Exemplarily, the display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc., which is not limited in this embodiment.

[0118] Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not limitations on the implementation methods of the present disclosure. For ordinary technicians in this field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present disclosure are still within the protection scope of the present disclosure.

Claims

1. A display panel, characterized in that: The display panel includes a base substrate, a display area and a frame area located on one side of the base substrate, the frame area is located at the edge of the display area, the display area includes a display function layer and an encapsulation layer stacked in sequence on the base substrate, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam, the isolation dam is arranged in the same layer as some film layers in the display function layer, and a recessed portion is arranged on the first surface of the isolation dam away from the base substrate.

2. The display panel according to claim 1, characterized in that: The display function layer includes at least a first planarization layer, a second planarization layer and an isolation column layer stacked in a direction away from the base substrate, and the isolation dam includes at least two isolation layers stacked in sequence in a direction away from the base substrate, and any isolation layer of the at least two isolation layers is arranged on the same layer as one of the first planarization layer, the second planarization layer and the isolation column layer.

3. The display panel according to claim 1, characterized in that: The display function layer at least includes a first planarization layer, a second planarization layer, a third planarization layer and an isolation column layer stacked in a direction away from the base substrate, and the isolation dam includes at least two isolation layers stacked in sequence in a direction away from the base substrate, and any isolation layer of the at least two isolation layers is arranged on the same layer as one of the first planarization layer, the second planarization layer, the third planarization layer and the isolation column layer.

4. The display panel according to claim 2 or 3, characterized in that: The isolation dam comprises a first isolation layer, a second isolation layer and a third isolation layer which are sequentially stacked in a direction away from the substrate; The first isolation layer is disposed in the same layer as the first planarization layer, the second isolation layer is disposed in the same layer as the second planarization layer, and the third isolation layer is disposed in the same layer as the isolation column layer; or The first isolation layer and the second planarization layer are arranged in the same layer, the second isolation layer and the third planarization layer are arranged in the same layer, and the third isolation layer and the isolation column layer are arranged in the same layer.

5. The display panel according to any one of claims 1 to 3, characterized in that: The recessed portion is a groove structure.

6. The display panel according to claim 5, characterized in that: The isolation dam comprises a first isolation layer, a second isolation layer and a third isolation layer which are sequentially stacked in a direction away from the substrate; The groove structure penetrates the third isolation layer; The groove structure penetrates the third isolation layer and the second isolation layer; or The groove structure penetrates the first isolation layer, the second isolation layer and the third isolation layer.

7. The display panel according to claim 5, characterized in that: In a direction from the frame area toward the display area, the recessed portion includes at least two groove structures.

8. The display panel according to claim 5, characterized in that: The isolation dam also includes a first isolation wall located on a side of the groove structure close to the display area and a second isolation wall located on a side of the groove structure away from the display area, and the width of the first isolation wall and the second isolation wall in a direction from the border area to the display area is less than or equal to the width of the groove structure.

9. The display panel according to claim 8, characterized in that: In the depth direction of the groove structure, the width of the groove structure decreases as the depth increases; and / or In a direction perpendicular to the base substrate, a height of the second isolation wall is greater than or equal to a height of the first isolation wall.

10. The display panel according to any one of claims 1 to 3, characterized in that: The recessed portion is a step structure, and the sidewall slope of the step structure is located on a side of the isolation dam close to the display area.

11. The display panel according to claim 10, characterized in that: The isolation dam includes a first isolation layer, a second isolation layer and a third isolation layer stacked in sequence in a direction away from the base substrate, and the step structure includes a first step and / or a second step, the first step is a step structure formed by the second isolation layer and the first isolation layer near the edge of the display area, and the second step is a step structure formed by the third isolation layer and the second isolation layer near the edge of the display area.

12. The display panel according to any one of claims 1 to 3, characterized in that: The border area also includes a first isolation column and a second isolation column. The first isolation column is arranged on a side of the isolation dam close to the display area, and the second isolation column is arranged on a side of the isolation dam away from the display area. The height of the isolation dam is greater than the heights of the first isolation column and the second isolation column.

13. The display panel according to claim 12, characterized in that: The display function layer further includes at least two source-drain metal layers stacked in a direction away from the base substrate, and the first isolation column and the second isolation column are arranged in the same layer as at least one of the at least two source-drain metal layers.

14. A method for preparing a display panel, characterized in that: The following steps are involved: providing a substrate base plate; A display area and a frame area are formed on one side of the base substrate, the frame area is located at the edge of the display area, the display area includes a display function layer and an encapsulation layer stacked in sequence on the base substrate, the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the base substrate, the frame area includes an isolation dam, the isolation dam is arranged in the same layer as some film layers in the display function layer, and a recessed portion is formed on the first surface of the isolation dam away from the base substrate.

15. A display device, characterized in that: Comprising the display panel as claimed in any one of claims 1 to 13.

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