Display panel, preparation method thereof and display device

Abstract

The invention discloses a display panel, a preparation method thereof and a display device. The display panel includes: a substrate; the plurality of sub-pixels are arranged on one side of the substrate and comprise first electrodes, light-emitting layers and second electrodes; the pixel definition layer is arranged on one side of the substrate and is used for limiting the positions of a plurality of sub-pixels; the overhanging structure is arranged on the side, away from the substrate, of the pixel defining layer and at least comprises a main body structure and a top structure, the top structure is arranged on the surface, away from the substrate, of the main body structure and shields the main body structure, and the overhanging structure is a conductive structure; the second electrodes of two adjacent sub-pixels are in contact with the side surface of the overhanging structure; the display panel further comprises a third electrode which covers the side, away from the substrate, of the top structure and makes contact with the top structure, the second electrode and the third electrode are disconnected, and the overhanging structure and the third electrode jointly serve as an auxiliary cathode. Through the arrangement, the problems of low strength, large width, large pixel cathode resistance and poor uniformity of a suspension structure of a display panel in the related technology can be solved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a method for preparing the same, and a display device. Background Art

[0002] Organic light emitting diodes (OLEDs) have the advantages of surface light sources, cold light, energy saving, fast response, flexibility, ultra-thinness and low cost. In the preparation process of OLED devices, maskless deposition and photolithography are often used to pattern pixels, and overhang structures are used instead of FMM (Fine Metal Mask), which has the characteristics of no FMM, independent pixels and high precision.

[0003] However, in the related art, the overhang structure of the display panel has problems of low strength and poor toughness, and the overhang structure is relatively wide, which will affect the aperture ratio of the pixel. At the same time, the cathode resistance of the pixel of the display panel is relatively large and the cathode uniformity is relatively poor. Summary of the invention

[0004] The present application mainly provides a display panel and a preparation method thereof, and a display device to solve the problems in the related art that the overhang structure of the display panel has low strength and large width, and the cathode resistance of the pixel is large and the uniformity is poor.

[0005] In order to solve the above technical problems, a technical solution adopted by the present application is: to provide a display panel, comprising:

[0006] substrate;

[0007] A plurality of sub-pixels are arranged on one side of the substrate; each of the sub-pixels comprises a first electrode, a light-emitting layer, and a second electrode which are stacked in sequence;

[0008] A pixel definition layer, disposed on one side of the substrate, defining positions of a plurality of sub-pixels;

[0009] The overhang structure is arranged on a side of the pixel definition layer away from the substrate and between two adjacent sub-pixels; the overhang structure at least comprises a main structure and a top structure, the top structure is arranged on a surface of the main structure away from the substrate and shields the main structure; the overhang structure is a conductive structure;

[0010] Among them, the second electrodes of two adjacent sub-pixels are both arranged in contact with the side of the overhanging structure; the display panel also includes a third electrode, which covers the side of the top structure away from the substrate and is arranged in contact with the top structure; the second electrode of the sub-pixel is disconnected from the third electrode; the overhanging structure and the third electrode together serve as an auxiliary cathode.

[0011] In some embodiments, the overhanging structure is formed in one step using a 3D printing process.

[0012] In some embodiments, the overhang structure further includes a base structure, which is disposed on a side of the main structure close to the pixel definition layer, and the main structure, the top structure and the base structure are all conductive structures;

[0013] The second electrodes of two adjacent sub-pixels are both arranged in contact with the base structure.

[0014] In some embodiments, the light-emitting layer of the sub-pixel is partially located on the surface of the top structure away from the substrate, and the light-emitting layers of two adjacent sub-pixels are partially spaced apart from each other on the top structure;

[0015] The third electrode covers the light emitting layer on the top structure and the top structure.

[0016] In some embodiments, the material of the overhanging structure includes any one of metal, metal oxide, or multi-metal alloy.

[0017] In some embodiments, the width of the top structure is 200 nm-1000 nm.

[0018] In some embodiments, the third electrode and the second electrodes of the plurality of sub-pixels are formed on the entire surface at one time.

[0019] In some embodiments, the display panel further includes:

[0020] Etching the protective layer to entirely cover the second electrodes of the plurality of sub-pixels, the third electrode and the side surfaces of the overhanging structure;

[0021] An organic encapsulation layer, covering a side of the etching protection layer away from the substrate;

[0022] The inorganic encapsulation layer covers a side of the organic encapsulation layer away from the substrate.

[0023] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a method for preparing a display panel, comprising:

[0024] Providing a substrate, and preparing a first electrode and a pixel definition layer of a plurality of sub-pixels on one side of the substrate;

[0025] A 3D printing process is used to prepare a hanging structure on the side of the pixel definition layer away from the substrate; wherein the hanging structure at least includes a main structure and a top structure, and the top structure is arranged on the surface of the main structure away from the substrate and covers the main structure; the hanging structure is a conductive structure;

[0026] sequentially preparing a plurality of light-emitting layers of the sub-pixels;

[0027] An electrode layer is deposited to form a second electrode covering the light-emitting layer of multiple sub-pixels, and a third electrode covering the top structure away from the substrate and in contact with the top structure; wherein the second electrode of the sub-pixel is disconnected from the third electrode, and the overhanging structure and the third electrode serve together as an auxiliary cathode.

[0028] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a display device, comprising:

[0029] A display panel, comprising any one of the display panels described above or a display panel prepared by the method for preparing a display panel described above;

[0030] A power supply is used to provide energy for the display panel.

[0031] The beneficial effects of the present application are as follows: Different from the prior art, the present application discloses a display panel and a method for preparing the same, and a display device. The display panel includes: a substrate; a plurality of sub-pixels, arranged on one side of the substrate, each sub-pixel including a first electrode, a light-emitting layer, and a second electrode stacked in sequence; a pixel definition layer, arranged on one side of the substrate, defining the positions of the plurality of sub-pixels; a suspension structure, arranged on the side of the pixel definition layer away from the substrate and located between two adjacent sub-pixels, the suspension structure at least including a main structure and a top structure, the top structure being arranged on the surface of the main structure away from the substrate and shielding the main structure, the suspension structure being a conductive structure; wherein the second electrodes of the two adjacent sub-pixels are both arranged in contact with the side of the suspension structure; the display panel also includes a third electrode, the third electrode covering the side of the top structure away from the substrate, and being arranged in contact with the top structure, the second electrode of the sub-pixel is disconnected from the third electrode, and the suspension structure and the third electrode serve together as an auxiliary cathode. By setting the overhang structure as a conductive structure as a whole, the strength of the overhang structure is relatively large, and it is beneficial to reduce the width of the overhang structure, thereby improving the pixel aperture ratio of the display panel; at the same time, by the second electrodes of two adjacent sub-pixels being in contact with the side of the overhang structure, the cathodes of multiple sub-pixels are electrically connected through the overhang structure, thereby realizing the full-surface connection of the cathodes of multiple sub-pixels, which is beneficial to reducing the resistance of the cathodes and improving the uniformity of the cathodes of multiple sub-pixels; further, the display panel includes a third electrode, and by covering the third electrode on the side of the top structure away from the substrate and contacting the top structure, the third electrode is electrically connected to the overhang structure to serve as an auxiliary cathode together, which is beneficial to increase the thickness of the auxiliary cathode, realize a full-surface mesh auxiliary cathode structure, and is more beneficial to reduce the full-surface resistance of the cathode, further improve the full-surface uniformity of the cathode, solve the problems of low strength and large width of the overhang structure of the display panel in the related art, large cathode resistance and poor uniformity of the pixels, and improve the performance and display effect of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0033] Figure 1 is a schematic structural diagram of a display panel provided in the first embodiment of the present application;

[0034] Figure 2 yes Figure 1 A schematic diagram of a top view of the distribution positions of the first electrode, the second electrode and the auxiliary cathode of the provided display panel;

[0035] Figure 3 is a schematic structural diagram of a display panel provided in a second embodiment of the present application;

[0036] Figure 4 is a schematic flow chart of a method for manufacturing a display panel provided in a third embodiment of the present application;

[0037] Figure 5 yes Figure 4 A structural schematic diagram corresponding to an implementation method of step S1 in FIG.

[0038] Figure 6 yes Figure 4 A structural schematic diagram corresponding to an implementation method of step S2 in the embodiment;

[0039] Figure 7 yes Figure 4 A structural schematic diagram corresponding to an implementation method of step S3 in the embodiment;

[0040] Figure 8 yes Figure 4 A structural schematic diagram corresponding to an implementation method of step S4 in FIG.

[0041] Fig. 9 It is a schematic diagram of the structure of a display device provided in the fourth embodiment of the present application.

[0042] Figure Number:

[0043] 100. Display panel; 1. Substrate; 2. Sub-pixel; 21. First electrode; 22. Light-emitting layer; 23. Second electrode; 3. Pixel definition layer; 4. Overhang structure; 41. Base structure; 42. Main structure; 43. Top structure; 5. Third electrode; 6. Auxiliary cathode; 7. Etching protection layer; 8. Organic encapsulation layer; 9. Inorganic encapsulation layer; 200. Power supply; 300. Display device. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The terms "first", "second", "third" in the embodiments of the present application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", "third" can expressly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] See also Figures 1 to 3 , Figure 1 is a schematic diagram of the structure of a display panel provided in the first embodiment of the present application, Figure 2 yes Figure 1 A schematic diagram of a top view of the distribution positions of the first electrode, the second electrode and the auxiliary cathode of the display panel is provided, Figure 3 It is a schematic diagram of the structure of a display panel provided in the second embodiment of the present application.

[0048] See also Figures 1 to 3The embodiment of the present application provides a display panel 100, which includes: a substrate 1, a plurality of sub-pixels 2, a pixel definition layer 3 and an overhang structure 4. Specifically, the substrate 1 is a driving substrate, a driving circuit layer (not shown) is provided on one side of the substrate 1, and the driving circuit layer may include a plurality of thin film transistors (not shown), and the plurality of sub-pixels 2 are provided on one side of the substrate 1, and specifically, the plurality of sub-pixels 2 are provided on the side of the driving circuit layer away from the substrate 1. Each sub-pixel 2 includes a first electrode 21, a light-emitting layer 22 and a second electrode 23 stacked in sequence, and specifically, the first electrode 21 may be an anode of the sub-pixel 2, and the second electrode 23 may be a cathode of the sub-pixel 2. The pixel definition layer 3 is provided on one side of the substrate 1 to define the positions of the plurality of sub-pixels 2; the overhang structure 4 is provided on the side of the pixel definition layer 3 away from the substrate 1 and between two adjacent sub-pixels 2. Among them, the overhang structure 4 includes at least a main structure 42 and a top structure 43, and the top structure 43 is provided on the surface of the main structure 42 away from the substrate 1 and shields the main structure 42, and specifically, the overhang structure 4 is a conductive structure. Among them, the second electrodes 23 of two adjacent sub-pixels 2 are both set in contact with the side of the overhang structure 4, and the display panel 100 also includes a third electrode 5, which covers the side of the top structure 43 away from the substrate 1 and is set in contact with the top structure 43. The second electrode 23 of the sub-pixel 2 is disconnected from the third electrode 5, and the overhang structure 4 and the third electrode 5 together serve as an auxiliary cathode 6.

[0049] It can be understood that by setting the overhang structure 4 as a conductive structure as a whole, the strength of the overhang structure 4 is relatively large, and it is beneficial to reduce the width of the overhang structure 4, thereby improving the pixel aperture ratio of the display panel 100; at the same time, by the second electrodes 23 of two adjacent sub-pixels 2 being in contact with the side of the overhang structure 4, the cathodes of multiple sub-pixels 2 are electrically connected through the overhang structure 4, and the cathodes of multiple sub-pixels 2 are connected on the entire surface, which is beneficial to reducing the resistance of the cathode and improving the uniformity of the cathodes of multiple sub-pixels 2; further, the display panel 100 includes a third electrode 5, and by covering the third electrode 5 on the side of the top structure 43 away from the substrate 1 and contacting the top structure 43, the third electrode 5 is electrically connected to the overhang structure 4 to serve as an auxiliary cathode 6 together, which is beneficial to increase the thickness of the auxiliary cathode 6, and realize a mesh auxiliary cathode 6 structure on the entire surface, which is more beneficial to reduce the entire surface resistance of the cathode, and further improve the entire surface uniformity of the cathode, solve the problems of low strength and large width of the overhang structure of the display panel in the related art, large cathode resistance and poor uniformity of the pixel, and improve the performance and display effect of the display panel 100.

[0050] For details, see Figure 1 to Figure 2In one embodiment, the overhang structure 4 includes a base structure 41, a main structure 42 and a top structure 43 which are stacked in sequence. The top structure 43 is arranged on the surface of the main structure 42 away from the substrate 1 and shields the main structure 42. The base structure 41 is arranged on the side of the main structure 42 close to the pixel definition layer 3. The top structure 43 has the widest width to shield the main structure 42. In this embodiment, the overhang structure 4 is a three-layer structure with different widths. The three-layer structure has higher structural strength and greater stability. In a specific embodiment, as Figure 1 As shown, the longitudinal section of the base structure 41 is roughly trapezoidal, the longitudinal section of the main structure 42 is a regular trapezoid, the width of the bottom of the main structure 42 is smaller than the width of the base structure 41, and the slope of the side of the main structure 42 is relatively large, the longitudinal section of the top structure 43 is roughly rectangular, and the width of the top structure 43 is larger than the width of the main structure 42 to cover the main structure 42. By using the overhang structure 4, the light-emitting layer 22 and the second electrode 23 of the sub-pixel 2 can be deposited in the pixel accommodating area defined by the pixel definition layer 3 without setting a fine metal mask. The overhang structure 4 separates different sub-pixels 2 so that each sub-pixel 2 is independent of each other.

[0051] The overhang structure 4 is an integrated structure, that is, the base structure 41, the main structure 42 and the top structure 43 are integrally formed. Specifically, in some embodiments, the overhang structure 4 is formed in one step by a 3D printing process, that is, the 3D printing technology is used to directly stack materials to directly form the overhang structure 4 of an integrated structure including the base structure 41, the main structure 42 and the top structure 43 in one step.

[0052] Among them, the main structure 42, the top structure 43 and the base structure 41 of the overhang structure 4 are all conductive structures, and the material of the overhang structure 4 may include any one or more of metals, metal oxides or multi-metal alloys. For example, the material of the overhang structure 4 may be a metal element such as aluminum, copper, molybdenum, nickel, titanium, magnesium, silver, calcium and lithium, or it may be a conductive metal oxide such as indium tin oxide and indium zinc oxide; or, the material of the overhang structure 4 may also be a multi-metal alloy composed of two or more metal materials. In a specific embodiment, the material of the overhang structure 4 is a conductive metal or other metal oxide or multi-metal alloy with low resistivity. The material of the overhang structure 4 can be selected according to the needs, as long as it has conductivity, so that the prepared overhang structure 4 is a conductive structure, and this application does not limit this.

[0053] It can be understood that the overhang structure 4 formed by directly printing with 3D printing technology using materials such as metals, metal oxides or multi-metal alloys allows the base structure 41, the main structure 42 and the top structure 43, which originally have a three-layer structure, to be directly formed at one time, without the need to prepare and etch layer by layer to form the base structure 41, the main structure 42 and the top structure 43 respectively, which effectively simplifies the process and saves the process flow. The prepared overhang structure 4 is an integrated structure, which is beneficial to enhancing the strength of the overhang structure 4.

[0054] Compared with the main structure and top structure formed by inorganic insulating materials in the related art, the base structure 41, the main structure 42 and the top structure 43 of the overhang structure 4 in the embodiment of the present application are all made of materials such as metals or metal oxides or multi-metal alloys. The structural strength of the base structure 41, the main structure 42 and the top structure 43 are relatively large, and it is not easy to have the problem of film layer shedding or collapse in the subsequent packaging film layer stacking process due to the low strength, poor toughness and brittle film quality of the inorganic insulating materials in the related art. At the same time, the overhang structure 4 has a large strength and does not need to have a large width like when it is made of inorganic insulating materials, which is beneficial to reducing the width of the overhang structure 4. The main structure 42 formed has a large slope, which is beneficial to improving the pixel aperture ratio of the display panel 100 and reducing the influence of the overhang structure 4 on the pixel aperture ratio, thereby improving the display performance, and is more suitable for high PPI (Pixels Per Inch) products. Moreover, the overhang structure 4 made of materials such as metals or metal oxides or multi-metal alloys is also beneficial to maintaining structural stability when dealing with bending deformation, which is beneficial to extending the life of the product.

[0055] When conventional metals or multi-metal alloys are formed into films by sputtering or other methods, the thickness of the formed film layer is difficult to reach the micrometer level, and the thickness of the film layer is relatively small. If the metal or multi-metal alloy is directly sputtered by sputtering or other methods to prepare the main structure 42, it is easy to cause the light-emitting layer 22 of the sub-pixel 2 in the pixel accommodating area defined by the pixel definition layer 3 and the part of the light-emitting layer 22 deposited on the top structure 43 of the overhang structure 4 to be unable to be disconnected, thereby affecting the normal performance of the display panel 100. Therefore, it is difficult to use metals or multi-metal alloys and other materials to prepare the main structure of the overhang structure in the related art. In the embodiment of the present application, directly using 3D printing technology to print metals, metal oxides or multi-metal alloys and other materials to prepare the overhang structure 4 can also eliminate the limitation that it is difficult to use metals or multi-metal alloys and other materials to prepare the main structure of the overhang structure in the related art, so that the overhang structure 4 has a higher strength and can reach a smaller width.

[0056] The overhang structure 4 is prepared by printing materials such as metal, metal oxide or multi-metal alloy using 3D printing technology, and the width of the overhang structure 4 can reach the nanometer level. Specifically, in some embodiments, the width of the top structure 43 is 200nm-1000nm. The width of the top structure 43 is set within the above range, and the overall width of the overhang structure 4 is small, which significantly reduces the influence of the overhang structure 4 on the pixel opening, which is conducive to further improving the pixel opening rate of the display panel 100, and the slope of the main structure 42 is larger, and the larger slope is more conducive to achieving the partition effect on different sub-pixels 2, thereby improving the performance of the display panel 100.

[0057] In other embodiments, other processes may also be used to prepare the overhang structure 4 in the embodiment of the present application, which is made of materials such as metal, metal oxide or multi-metal alloy and includes a base structure 41, a main structure 42 and a top structure 43, and can be selected as needed.

[0058] like Figure 1 As shown, in some embodiments, the second electrodes 23 of two adjacent sub-pixels 2 are both arranged in contact with the substrate structure 41. Since the substrate structure 41 is a conductive structure, the second electrodes 23 of two adjacent sub-pixels 2 are in contact with the substrate structure 41, so that the second electrodes 23 of the two adjacent sub-pixels 2, i.e., the cathodes, are electrically connected, thereby enabling the cathodes of multiple sub-pixels 2 of the display panel 100 to be electrically connected over the entire surface, thereby realizing a mesh connection of the cathodes between different sub-pixels 2, which is beneficial to improving the uniformity of the entire surface signal of the cathode.

[0059] In some embodiments, the third electrode 5 of the display panel 100 covers the side of the top structure 43 away from the substrate 1 and is disposed in contact with the top structure 43. The overhanging structure 4 and the third electrode 5 serve together as an auxiliary cathode 6. Figure 1 As shown, part of the light-emitting layer 22 of the sub-pixel 2 is located on the surface of the top structure 43 away from the substrate 1, and the parts of the light-emitting layer 22 of two adjacent sub-pixels 2 located on the top structure 43 are spaced apart from each other, that is, the surface of the top structure 43 away from the substrate 1 is not fully covered by the part of the light-emitting layer 22 of the sub-pixel 2 located above the top structure 43, and part of the surface of the top structure 43 away from the substrate 1 is still exposed by the parts of the light-emitting layer 22 of two adjacent sub-pixels 2 located on the top structure 43, and the third electrode 5 covers the light-emitting layer 22 on the top structure 43 and the top structure 43. Specifically, the third electrode 5 fully covers the surface of the light-emitting layer 22 on the top structure 43 away from the substrate 1 and the part of the surface of the top structure 43 away from the substrate 1 exposed by the above-mentioned light-emitting layer 22, so that the third electrode 5 is arranged in contact with the top structure 43 of the overhang structure 4.

[0060] Since the entire structure of the overhang structure 4 is conductive, the third electrode 5 and the overhang structure 4 are both conductive structures, and the third electrode 5 on the top of the overhang structure 4 is directly in contact with the overhang structure 4. The third electrode 5 and the entire overhang structure 4 can be used as an auxiliary cathode 6, which is equivalent to increasing the thickness of the auxiliary cathode 6. The overhang structure 4 and the third electrode 5 on its top are both a full-surface mesh structure (such as Figure 2 As shown), a mesh auxiliary cathode 6 structure is realized on the whole surface. Specifically, as Figure 2 As shown, since the first electrode 21, i.e., the anode, corresponds to an independent planar electrode in the display area of ​​the display panel 100, the gap position (i.e., the position between the anodes of two adjacent sub-pixels 2) can be used as the auxiliary cathode 6 with a larger area, and they can be connected to each other to form a mesh structure, which is conducive to reducing resistance. Moreover, the auxiliary cathode 6 is electrically connected to the cathode of the sub-pixel 2, which can further effectively reduce the overall surface resistance of the cathode of the sub-pixel 2 of the display panel 100, further improve the overall surface uniformity of the cathode, solve the problem of large resistance and poor uniformity of the cathode of the pixel of the display panel in the related art, and improve the display performance and display effect of the display panel 100.

[0061] In some embodiments, the third electrode 5 of the display panel 100 and the second electrodes 23 of the multiple sub-pixels 2 are formed on the entire surface at one time. It should be noted that the entire surface formation at one time here means that the third electrode 5 and the second electrodes 23 of the multiple sub-pixels 2 are prepared and formed by a single film forming process, that is, the third electrode 5 and the second electrodes 23 of the multiple sub-pixels 2 are prepared and formed at the same time, and the third electrode 5 covers the top structure 43 of the overhang structure 4 on the entire surface, which can effectively simplify the process, save process flow, and save costs.

[0062] Specifically, after the first electrode 21 (anode) and the pixel definition layer 3 of the sub-pixel 2 are sequentially prepared on the substrate 1, the overhang structure 4 is printed and prepared by 3D printing technology, and then the overhang structure 4 is directly used as a blocking structure to deposit the light-emitting layer 22 of the sub-pixel 2 in the pixel accommodation area defined by the pixel definition layer 3. Specifically, the material of the light-emitting layer 22 can be an organic light-emitting material, and the colors of the light-emitting layers 22 of the multiple sub-pixels 2 can be different. For example, the multiple sub-pixels 2 can include three sub-pixels 2 of different colors, and the colors of the light-emitting layers 22 of the three sub-pixels 2 of different colors can be red, green and blue, respectively. The red, green and blue light-emitting layers 22 can be prepared in sequence. After the red, green and blue light-emitting layers 22 are prepared separately, the electrode layer is deposited uniformly to form the second electrode 23 directly on the top of the light-emitting layer 22 of the sub-pixel 2 at one time, and the third electrode 5 covering the side of the top structure 43 away from the substrate 1 and contacting the top structure 43 is formed on the top of the overhang structure 4. The cathodes of the multiple sub-pixels 2 and the third electrode 5 are prepared at the same time, which reduces the preparation process of the film layer.

[0063] In some embodiments, see Figure 1 The display panel 100 further includes an etching protection layer 7 , an organic encapsulation layer 8 and an inorganic encapsulation layer 9 which are sequentially arranged on a side of the third electrode 5 away from the substrate 1 .

[0064] Among them, the material of the etching protection layer 7 is an inorganic insulating material, specifically, it can be a silicon nitride inorganic material. The etching protection layer 7 covers the second electrode 23, the third electrode 5 and the side of the overhang structure 4 of multiple sub-pixels 2, that is, the etching protection layer 7 wraps all the structures between its bottom and the substrate 1 to protect the organic light-emitting layer 22 and the second electrode 23 of the sub-pixel 2 of the display panel 100 and the third electrode 5 on the top of the overhang structure 4. Specifically, in this embodiment, since the overhang structure 4 includes a three-layer structure of a base structure 41, a main structure 42 and a top structure 43, the slope at the connection position between the portion of the etching protection layer 7 covering the second electrode 23 of the sub-pixel 2 and the portion covering the side of the overhang structure 4 is relatively gentle, and the etching protection layer 7 is not prone to breakage or falling off, and the structural strength is relatively high, and the protection performance of the display panel 100 is stronger.

[0065] The organic encapsulation layer 8 is an organic material, and the organic encapsulation layer 8 covers the side of the etching protection layer 7 away from the substrate 1. Specifically, the surface of the organic encapsulation layer 8 away from the substrate 1 is a plane; the inorganic encapsulation layer 9 is an inorganic insulating material, and the inorganic encapsulation layer 9 covers the side of the organic encapsulation layer 8 away from the substrate 1.

[0066] By adopting the structure of inorganic etching protection layer 7, organic encapsulation layer 8 and inorganic encapsulation layer 9 to encapsulate the display panel 100, the advantages of good water and oxygen barrier property of inorganic encapsulation material and good film-forming property of organic encapsulation material are combined. The external environment can be isolated to prevent impurities, oxygen, moisture and other substances in the air from polluting and corroding the display panel 100, and to prevent damage caused by external forces. The packaging reliability is improved, which is beneficial to extend the life of the device and improve the stability of the device.

[0067] See also Figure 3 In another embodiment, different from the display panel 100 provided in the first embodiment, in this embodiment, the overhang structure 4 only includes a main structure 42 and a top structure 43 which are stacked, and does not include a base structure 41 located between the main structure 42 and the pixel definition layer 3. In this embodiment, the overhang structure 4 including the main structure 42 and the top structure 43 is directly prepared by stacking at one time using 3D printing technology, and the overhang structure 4 is also an integrated structure, which is formed at one time using 3D printing technology.

[0068] Specifically, the longitudinal section of the main structure 42 is a regular trapezoid, the longitudinal section of the top structure 43 is a rectangle, and the width of the top structure 43 is greater than the width of the main structure 42 to shield the main structure 42. The second electrodes 23, i.e., cathodes of two adjacent sub-pixels 2 are directly in contact with the side of the main structure 42, and the light-emitting layer 22 is not in contact with the main structure 42, so that the cathodes of two adjacent sub-pixels 2 are directly electrically connected through the main structure 42, and the cathodes of multiple sub-pixels 2 are connected on the entire surface, thereby reducing the entire surface resistance of the cathode and improving uniformity.

[0069] It can be understood that compared with the three-layer overhang structure 4 of the display panel 100 in the first embodiment, in this embodiment, the overhang structure 4 only includes two layers of stacked main structure 42 and top structure 43. The thickness of the overhang structure 4 is relatively thin, which can realize the design of a thinner display panel 100, meet more usage requirements, and broaden the application scenarios of the display panel 100.

[0070] In this embodiment, the remaining structures and configurations of the display panel 100 are the same as those of the display panel 100 in the first embodiment, and can achieve the same or similar technical effects. The relevant descriptions in the first embodiment may be referred to and will not be repeated here.

[0071] See also Figures 4 to 8 , Figure 4 is a schematic flow chart of a method for manufacturing a display panel provided in the third embodiment of the present application, Figure 5 yes Figure 4 The structural diagram corresponding to the implementation method of step S1 in FIG. Figure 6 yes Figure 4 The structural diagram corresponding to the implementation method of step S2 in FIG. Figure 7 yes Figure 4 The structural diagram corresponding to the implementation method of step S3 in FIG. Figure 8 yes Figure 4 A structural schematic diagram corresponding to an implementation method of step S4 in FIG.

[0072] See also Figure 4 , an embodiment of the present application provides a method for preparing a display panel 100, which is used to prepare any of the display panels 100 described above. Specifically, the method for preparing the display panel 100 includes:

[0073] S1: providing a substrate 1 , and preparing a first electrode 21 and a pixel definition layer 3 of a plurality of sub-pixels 2 on one side of the substrate 1 .

[0074] First, a substrate 1 is provided. Specifically, the substrate 1 may be a driving substrate. A driving circuit layer is provided on one side of the substrate 1. The driving circuit layer may include a plurality of thin film transistors. Then, a plurality of first electrodes 21 of sub-pixels 2 and a pixel definition layer 3 are prepared on one side of the substrate 1. Specifically, an electrode layer may be first deposited on the side of the driving circuit layer away from the substrate 1. The electrode layer is a first electrode layer. The first electrode layer covers a surface of the substrate 1. The first electrode layer is processed by a patterning process to form a plurality of mutually spaced first electrodes 21, which serve as anodes of the plurality of sub-pixels 2. An insulating film layer is deposited on the side of the plurality of first electrodes 21 away from the substrate 1. The insulating film layer entirely covers the side of the plurality of first electrodes 21 away from the substrate 1. The insulating film layer is then patterned to form a pixel definition layer 3 that defines a plurality of pixel accommodating areas and exposes the plurality of first electrodes 21.

[0075] In one embodiment, step S1 may form Figure 5 The structure shown.

[0076] S2: Prepare the overhang structure 4 on the side of the pixel definition layer 3 away from the substrate 1 by using a 3D printing process.

[0077] Specifically, a 3D printing process is used to prepare the overhang structure 4 on the side of the pixel definition layer 3 away from the substrate 1. The overhang structure 4 at least includes a main structure 42 and a top structure 43, the top structure 43 is arranged on the surface of the main structure 42 away from the substrate 1 and covers the main structure 42, and the overhang structure 4 is a conductive structure.

[0078] In one embodiment, the overhang structure 4 may include only a main structure 42 and a top structure 43, both of which are conductive structures. Alternatively, in another embodiment, the overhang structure 4 may include a base structure 41, a main structure 42 and a top structure 43, the base structure 41 being disposed on a side of the main structure 42 close to the pixel definition layer 3, and the base structure 41, the main structure 42 and the top structure 43 are all conductive structures.

[0079] The material of the overhang structure 4 may include any one or more of metals, metal oxides or multi-metal alloys. For example, the material of the overhang structure 4 may be a single metal such as aluminum, copper, molybdenum, nickel, titanium, magnesium, silver, calcium and lithium, or may be a conductive metal oxide such as indium tin oxide and indium zinc oxide; or the material of the overhang structure 4 may also be a multi-metal alloy composed of two or more metal materials. In a specific embodiment, the material of the overhang structure 4 is a conductive metal or other metal oxide or multi-metal alloy with low resistivity.

[0080] The above-mentioned materials are directly stacked at one time through the 3D printing process to form an integrated overhang structure 4, that is, the overhang structure 4 is formed at one time by the 3D printing process, which reduces the process steps, saves costs, and can also eliminate the limitation that it is difficult to use metal or multi-metal alloy materials to prepare the main structure of the overhang structure in the related technology; and the overhang structure 4 formed by the 3D printing technology of the above-mentioned materials has a higher structural strength, which is also conducive to maintaining the stability of the structure when dealing with bending deformation, and is conducive to extending the life of the product. The width of the overhang structure 4 is smaller, specifically, the width of the overhang structure 4 can reach the nanometer level. In some embodiments, the width of the top structure 43 is 200nm-1000nm, which is conducive to improving the pixel aperture ratio of the display panel 100 formed, and is more suitable for products with high PPI (Pixels Per Inch). The slope of the main structure 42 is larger, and a larger slope is more conducive to achieving the partition effect of different sub-pixels 2, and improving the performance of the display panel 100 formed.

[0081] In some embodiments, after step S2, the following can be obtained: Figure 6 In some other embodiments, the prepared overhang structure 4 may also be a two-layer structure including only a main structure 42 and a top structure 43 .

[0082] S3: sequentially preparing the light-emitting layers 22 of a plurality of sub-pixels 2.

[0083] Specifically, the light-emitting layer 22 of the sub-pixel 2 is deposited in the pixel accommodating area defined by the pixel definition layer 3, so that the light-emitting layer 22 covers the surface of the first electrode 21 away from the substrate 1, and partially extends to the surface of the pixel definition layer 3 away from the substrate 1, and the light-emitting layer 22 is spaced apart from the side of the overhang structure 4, that is, the light-emitting layer 22 in the pixel accommodating area does not contact the side of the base structure 41 or the main structure 42 of the overhang structure 4. Specifically, the material of the light-emitting layer 22 is an organic light-emitting material.

[0084] The light-emitting layers 22 of multiple different sub-pixels 2 have different colors. For example, the multiple sub-pixels 2 may include sub-pixels 2 of three different colors. The colors of the light-emitting layers 22 of the three different colors of sub-pixels 2 may be red, green and blue, respectively. The red, green and blue light-emitting layers 22 are prepared sequentially.

[0085] In some embodiments, the light-emitting layer 22 is partially deposited on the surface of the top structure 43 of the overhang structure 4 away from the substrate 1, and the portions of the light-emitting layer 22 of two adjacent sub-pixels 2 located on the top structure 43 are spaced apart from each other, that is, the surface of the top structure 43 away from the substrate 1 is not fully covered by the portions of the light-emitting layer 22 of the sub-pixels 2 located above the top structure 43, and portions of the surface of the top structure 43 away from the substrate 1 are still exposed by the portions of the light-emitting layer 22 of two adjacent sub-pixels 2 located on the top structure 43.

[0086] In some embodiments, after step S3, the following can be obtained: Figure 7 The structure shown.

[0087] S4 : depositing an electrode layer to form a second electrode 23 covering the light-emitting layer 22 of the plurality of sub-pixels 2 , and a third electrode 5 covering a side of the top structure 43 away from the substrate 1 and in contact with the top structure 43 .

[0088] Specifically, an electrode layer is deposited on the side of the light-emitting layer 22 away from the substrate 1, and the electrode layer is a second electrode layer, forming a second electrode 23 covering the light-emitting layer 22 of the multiple sub-pixels 2, and a third electrode 5 covering the side of the top structure 43 away from the substrate 1 and in contact with the top structure 43, and the third electrode 5 is disconnected from the second electrodes 23 of the multiple sub-pixels 2.

[0089] Specifically, the second electrode 23 is the cathode of the sub-pixel 2, and the side surfaces of the second electrodes 23 of two adjacent sub-pixels 2 are arranged in contact with the side surfaces of the overhang structure 4. In a specific embodiment, the overhang structure 4 includes a base structure 41, a main structure 42, and a top structure 43, and the side surfaces of the second electrodes 23 of two adjacent sub-pixels 2 are arranged in contact with the side surfaces of the base structure 41. Since the overhang structure 4 is a conductive structure, the second electrodes 23 of two adjacent sub-pixels 2 are arranged in contact with the side surfaces of the overhang structure 4, and the overhang structure 4 is used to realize electrical connection between the cathodes of two adjacent sub-pixels 2, so that the cathodes of multiple sub-pixels 2 are interconnected to form a whole surface of the cathode, which is beneficial to reduce the whole surface resistance of the cathode and improve the whole surface signal uniformity of the cathode.

[0090] The third electrode 5 of the display panel 100 covers the side of the top structure 43 away from the substrate 1, and is arranged in contact with the top structure 43, and the overhang structure 4 and the third electrode 5 together serve as an auxiliary cathode 6. In a specific embodiment, the light-emitting layer 22 of the sub-pixel 2 is partially located on the surface of the top structure 43 away from the substrate 1, and the parts of the light-emitting layers 22 of two adjacent sub-pixels 2 located on the top structure 43 are arranged at intervals from each other, and the third electrode 5 covers the light-emitting layer 22 on the top structure 43 and the top structure 43. Specifically, the third electrode 5 fully covers the surface of the light-emitting layer 22 on the top structure 43 away from the substrate 1 and the surface of the top structure 43 away from the substrate 1 exposed by the light-emitting layer 22, so that the third electrode 5 is arranged in contact with the top structure 43 of the overhang structure 4.

[0091] Since the entire structure of the overhang structure 4 is conductive, the third electrode 5 and the overhang structure 4 are both conductive structures, and the third electrode 5 on the top of the overhang structure 4 is directly in contact with the overhang structure 4. The third electrode 5 and the entire overhang structure 4 can be used as an auxiliary cathode 6, which is equivalent to increasing the thickness of the auxiliary cathode 6. The overhang structure 4 and the third electrode 5 on its top are both a full-surface mesh structure (such as Figure 2 As shown in the figure, a mesh auxiliary cathode 6 structure is realized for the entire surface. Specifically, since the anode is an independent planar electrode in the display area of ​​the display panel 100, the area of ​​the gap position (i.e., the position between the anodes of two adjacent sub-pixels 2) that can be used as the auxiliary cathode 6 is relatively large, and they can be connected to each other to form a mesh structure, which is beneficial to reduce the resistance. Moreover, the auxiliary cathode 6 is electrically connected to the cathode contact of the sub-pixel 2, which can further effectively reduce the entire surface resistance of the cathode of the sub-pixel 2 of the display panel 100, further improve the uniformity of the entire surface of the cathode, solve the problem of large resistance and poor uniformity of the cathode of the pixel of the display panel in the related art, and improve the display performance and display effect of the display panel 100.

[0092] The third electrode 5 and the second electrodes 23 of the multiple sub-pixels 2 are formed on the entire surface at one time, that is, they are prepared and formed simultaneously from the same electrode layer, and the electrode layer (that is, the second electrode layer) is deposited only once. The third electrode 5 that covers the top structure 43 of the overhanging structure 4 on the entire surface, and the second electrode 23 that covers the light-emitting layer 22 of the multiple sub-pixels 2 and is disconnected from the third electrode 5 can be prepared simultaneously through a single film-forming process, which effectively simplifies the process, saves the process flow, and saves costs.

[0093] In some embodiments, after step S4, the following can be obtained: Figure 8 The structure shown.

[0094] Furthermore, after the third electrode 5 and the second electrodes 23 of the plurality of sub-pixels 2 are formed, the formed structure can be further encapsulated. Specifically, an etching protection layer 7, an organic encapsulation layer 8 and an inorganic encapsulation layer 9 can be sequentially deposited on the side of the third electrode 5 away from the substrate 1 to encapsulate the formed structure.

[0095] Among them, the material of the etching protection layer 7 is an inorganic insulating material, specifically, it can be a silicon nitride inorganic material. The etching protection layer 7 covers the second electrode 23, the third electrode 5 and the side of the overhang structure 4 of multiple sub-pixels 2, that is, the etching protection layer 7 wraps all the structures between its bottom and the substrate 1 to protect the organic light-emitting layer 22 and the second electrode 23 of the sub-pixel 2 of the display panel 100 and the third electrode 5 on the top of the overhang structure 4. The organic encapsulation layer 8 is an organic material, and the organic encapsulation layer 8 covers the side of the etching protection layer 7 away from the substrate 1. Specifically, the surface of the organic encapsulation layer 8 away from the substrate 1 is a plane; the inorganic encapsulation layer 9 is an inorganic insulating material, and the inorganic encapsulation layer 9 covers the side of the organic encapsulation layer 8 away from the substrate 1.

[0096] By using an inorganic etching protection layer 7, an organic encapsulation layer 8 and an inorganic encapsulation layer 9 to encapsulate the prepared structure, the advantages of the good water and oxygen barrier properties of the inorganic encapsulation material and the good film-forming properties of the organic encapsulation material are combined. The external environment can be isolated to prevent impurities, oxygen, moisture and other substances in the air from contaminating and corroding the display panel 100, and to prevent damage caused by external forces. The packaging reliability is improved, which is beneficial to extending the life of the device and improving the stability of the device.

[0097] In some embodiments, after the prepared structure is encapsulated by depositing the etching protection layer 7, the organic encapsulation layer 8 and the inorganic encapsulation layer 9, the following can be obtained: Figure 1 The structure of the display panel 100 is shown.

[0098] In other embodiments, the overhang structure 4 prepared in step S2 only includes two layers of the main structure 42 and the top structure 43. After the subsequent steps and packaging of the prepared structure, the following structure can be obtained: Figure 3 The structure of the display panel 100 is shown.

[0099] See also Fig. 9 , Fig. 9 It is a schematic diagram of the structure of a display device provided in the fourth embodiment of the present application.

[0100] See also Fig. 9The embodiment of the present application further provides a display device 300, which includes a display panel 100 and a power supply 200. The display panel 100 may be any display panel 100 provided in the first embodiment or the second embodiment, or may be a display panel 100 prepared by the method for preparing the display panel 100 as described above. The power supply 200 supplies energy to the display panel 100 so that the display panel 100 can stably realize the image display function.

[0101] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A display panel, characterized in that: include: substrate; A plurality of sub-pixels are arranged on one side of the substrate; each of the sub-pixels comprises a first electrode, a light-emitting layer, and a second electrode which are stacked in sequence; A pixel definition layer, disposed on one side of the substrate, defining positions of a plurality of sub-pixels; The overhang structure is arranged on a side of the pixel definition layer away from the substrate and between two adjacent sub-pixels; the overhang structure at least comprises a main structure and a top structure, the top structure is arranged on a surface of the main structure away from the substrate and shields the main structure; the overhang structure is a conductive structure; Among them, the second electrodes of two adjacent sub-pixels are both arranged in contact with the side of the overhanging structure; the display panel also includes a third electrode, which covers the side of the top structure away from the substrate and is arranged in contact with the top structure; the second electrode of the sub-pixel is disconnected from the third electrode; the overhanging structure and the third electrode together serve as an auxiliary cathode.

2. The display panel according to claim 1, characterized in that: The overhanging structure is formed in one step by using a 3D printing process.

3. The display panel according to claim 2, characterized in that: The overhang structure further includes a base structure, which is disposed on a side of the main structure close to the pixel definition layer, and the main structure, the top structure and the base structure are all conductive structures; The second electrodes of two adjacent sub-pixels are both arranged in contact with the base structure.

4. The display panel according to claim 3, characterized in that: The light-emitting layer of the sub-pixel is partially located on the surface of the top structure away from the substrate, and the light-emitting layers of two adjacent sub-pixels are partially arranged on the top structure at intervals; The third electrode covers the light emitting layer on the top structure and the top structure.

5. The display panel according to claim 2, characterized in that: The material of the overhanging structure includes any one of metal, metal oxide or multi-metal alloy.

6. The display panel according to claim 2, characterized in that: The width of the top structure is 200nm-1000nm.

7. The display panel according to any one of claims 1 to 6, characterized in that: The third electrode and the second electrodes of the plurality of sub-pixels are formed on the entire surface at the same time.

8. The display panel according to claim 7, characterized in that: The display panel further includes: Etching the protective layer to entirely cover the second electrodes of the plurality of sub-pixels, the third electrode and the side surfaces of the overhanging structure; An organic encapsulation layer, covering a side of the etching protection layer away from the substrate; The inorganic encapsulation layer covers a side of the organic encapsulation layer away from the substrate.

9. A method for preparing a display panel, characterized in that: include: Providing a substrate, and preparing a first electrode and a pixel definition layer of a plurality of sub-pixels on one side of the substrate; A 3D printing process is used to prepare a hanging structure on the side of the pixel definition layer away from the substrate; wherein the hanging structure at least includes a main structure and a top structure, and the top structure is arranged on the surface of the main structure away from the substrate and covers the main structure; the hanging structure is a conductive structure; sequentially preparing a plurality of light-emitting layers of the sub-pixels; An electrode layer is deposited to form a second electrode covering the light-emitting layer of multiple sub-pixels, and a third electrode covering the top structure away from the substrate and in contact with the top structure; wherein the second electrode of the sub-pixel is disconnected from the third electrode, and the overhanging structure and the third electrode serve together as an auxiliary cathode.

10. A display device, characterized in that: include: A display panel, comprising the display panel according to any one of claims 1 to 8 or a display panel prepared by the method for preparing a display panel according to claim 9; A power supply is used to provide energy for the display panel.

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