Display panel, manufacturing method thereof, and display device

Abstract

This disclosure discloses a display panel. The display panel includes a substrate, an anode layer, a pixel isolation layer, an organic light-emitting layer, a cathode layer, and an organic insulating encapsulation layer. The organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure. Coating with a leveling organic insulating encapsulation layer can better adapt to surfaces with complex morphologies. The continuous coverage of the step structure by the organic insulating encapsulation layer effectively blocks the path of moisture intrusion through the pixel openings, thereby solving the failure problem caused by insufficient coverage of the encapsulation layer. The leveling organic insulating encapsulation layer can improve the flatness of the substrate after encapsulation.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more particularly to display panels, methods of manufacturing the same, and display devices. Background Technology

[0002] In the display panel manufacturing industry, encapsulation technology is a crucial step in ensuring the long-term stable operation of display panels. Currently, mainstream display panels typically employ a layered structure of inorganic materials as an encapsulation barrier. For example, dense thin films of silicon nitride and silicon oxide are formed through chemical vapor deposition (CVD) to prevent external water and oxygen from corroding the internal light-emitting materials. This type of encapsulation layer performs reliably in traditional planar structures, effectively extending the lifespan of organic light-emitting diode (OLED) or quantum dot displays. However, with the rapid iteration of display technology towards higher resolution, larger sizes, and greater flexibility, the complexity of the internal structure of the panel has significantly increased. The density of the encapsulation layer directly determines the operational stability of the device; even slight water and oxygen infiltration can cause pixel dark spots, brightness degradation, or even large-area blackouts. Therefore, improving the encapsulation effect of the encapsulation layer has become a critical technical challenge that the industry urgently needs to overcome. Summary of the Invention

[0003] This disclosure aims to address screen failures caused by packaging issues.

[0004] In a first aspect, this disclosure provides a display panel. The display panel includes a substrate, an anode layer, a pixel isolation layer, an organic light-emitting layer, a cathode layer, and an organic insulating encapsulation layer.

[0005] The anode layer includes multiple anode units corresponding to multiple pixels, and the array of anode units is distributed on the upper surface of the substrate. A pixel isolation layer is disposed on the upper surface of the substrate and used to separate the anode units of two adjacent pixels. In a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening defining a corresponding pixel. An organic light-emitting layer uniformly covers the upper surfaces of the anode layer and the pixel isolation layer. A cathode layer uniformly covers the upper surface of the organic light-emitting layer, and the surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conformal to the pixel opening. An organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous cover on the sidewalls and bottom of the step structure.

[0006] In the fabrication of high-resolution, large-size, and flexible display panels, high pixel density leads to complex and dense step structures. For example, the dense arrangement of tiny pixels in smartphone screens requires the encapsulation layer to achieve seamless coverage over extremely small step sizes. The substrate serves as a support structure, with its surface-distributed anode layers achieving pixel driving through an array design. The pixel isolation layer extends beyond the height of the anode layer in a direction perpendicular to the substrate surface (the first direction), forming pixel openings and physically isolating adjacent pixels. This design effectively prevents crosstalk between the light-emitting layers. Due to the presence of these pixel openings, a height difference inevitably forms between the top surface of the anode unit and the top surface of the pixel isolation layer. As the organic light-emitting layer and cathode layer are uniformly deposited from bottom to top, the height difference on the side of the cathode layer away from the organic light-emitting layer in the first direction inevitably constitutes a step structure conforming to the pixel openings. In the traditional display panel fabrication process, chemical vapor deposition (CVD) technology, due to its material limitations, has insufficient coverage for high step structures, leading to moisture intrusion through gaps and device failure. The root cause of this problem lies in the poor fluidity and wettability of CVD materials, which cannot effectively fill the step structure formed by the height difference between the anode layer and the pixel isolation layer. This step structure exacerbates the difficulty of covering the encapsulation layer. The presence of this step structure makes it difficult for traditional CVD processes to form a continuous film when covering the cathode layer, resulting in encapsulation defects. The film layer formed by vapor deposition in CVD processes is prone to fractures or uneven thickness in steep sidewalls and recessed areas, thus forming tiny gaps at the discontinuity between the cathode layer surface and the encapsulation layer. These gaps become channels for moisture intrusion, leading to oxidation or even short circuits in the organic light-emitting layer or cathode layer, ultimately causing the display panel to malfunction.

[0007] To address the aforementioned issues, the technical solution proposed in this disclosure employs a display panel structure design based on a leveling organic insulating encapsulation layer and a spin coating process. The leveling organic insulating encapsulation layer's coverage capability is optimized through a spin coating process. Specifically, due to its inherent leveling properties combined with the spin coating process, the organic insulating encapsulation layer, after coating, can naturally flow and fill the recessed areas of the stepped structure using gravity and centrifugal force. This promotes uniform material extension, eliminates local accumulation or gaps, and achieves continuous coverage on the sidewalls and bottom of the stepped structure. Coating with a leveling organic insulating encapsulation layer allows for better adaptation to surfaces with complex morphologies. The continuous coverage of the stepped structure by the organic insulating encapsulation layer effectively blocks the path of moisture intrusion through the sidewalls and bottom of the stepped structure, thus solving the failure problem caused by insufficient encapsulation layer coverage. The leveling organic insulating encapsulation layer improves the flatness of the substrate after encapsulation. Simultaneously, the leveling property of the organic insulating encapsulation layer also provides good ramping performance, increasing its coverage capability for stepped structures.

[0008] The display panel disclosed herein systematically optimizes the adaptability of the encapsulation layer to high-step structures. The self-filling capability of the leveling material enables it to conform to the geometric features of the step structure, while the uniform film formation characteristics of the spin coating process ensure the stability of the film thickness. For example, at the steep sidewalls at the junction of the pixel isolation layer and the anode layer, liquid insulating material flows to fill the recessed area, forming a seamless encapsulation layer, significantly improving encapsulation reliability. This process not only eliminates microcracks caused by discontinuous coverage in traditional CVD processes but also improves the flatness of the top of the organic encapsulation layer through the leveling properties of the material, further reducing the complexity of subsequent processes.

[0009] Furthermore, in the application of flexible display panels, the flexible properties of the organic insulating encapsulation layer with leveling properties can adapt to the bending deformation of the substrate, preventing the encapsulation layer from cracking due to mechanical stress, thereby improving the durability of flexible devices.

[0010] In summary, the leveling organic insulating encapsulation layer not only solves the inherent defects of CVD process in terms of coverage of high-step structures, but its material properties, combined with the spin coating process, also achieve the continuity and reliability of the encapsulation layer.

[0011] In one exemplary embodiment, the organic insulating encapsulation layer has a via formed in a region corresponding to the pixel isolation layer to expose the cathode layer. The display panel further includes an auxiliary cathode layer formed on a surface of the organic insulating encapsulation layer away from the cathode layer and in contact with the cathode layer through the via.

[0012] In one exemplary embodiment, the display panel further includes an inorganic water and oxygen barrier layer and an auxiliary cathode layer. The inorganic water and oxygen barrier layer is disposed between the cathode layer and the organic insulating encapsulation layer; the auxiliary cathode layer is formed on the surface of the organic insulating encapsulation layer away from the cathode layer. The organic insulating encapsulation layer has a first via formed in the region corresponding to the pixel isolation layer. The inorganic water and oxygen barrier layer has a second via formed through the first via to expose the cathode layer, and the auxiliary cathode layer contacts the cathode layer through the first via and the second via.

[0013] In one exemplary embodiment, the organic insulating encapsulation layer is composed of a photosensitive material.

[0014] In one exemplary embodiment, the material of the organic insulating encapsulation layer is polyimide or acrylic resin.

[0015] Secondly, this disclosure proposes a method for manufacturing a display panel, the method comprising:

[0016] Provide substrate.

[0017] An anode layer is disposed on the upper surface of the substrate. The anode layer includes a plurality of anode units corresponding to a plurality of pixels, and the plurality of anode units are arrayed on the upper surface of the substrate.

[0018] A pixel isolation layer is disposed on the upper surface of the substrate. The pixel isolation layer is used to separate the anode units of two adjacent pixels. In a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening for defining the corresponding pixel.

[0019] An organic light-emitting layer is uniformly covered on the upper surface of the anode layer and the pixel isolation layer.

[0020] A cathode layer is uniformly covered on the upper surface of the organic light-emitting layer. The surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conforming to the pixel opening.

[0021] An organic insulating encapsulation layer is formed on the upper surface of the cathode layer. The organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure.

[0022] In one exemplary embodiment, the organic insulating encapsulation layer is formed of a photosensitive material, and the fabrication method further includes: forming vias in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer by an exposure and development process to expose the cathode layer; and forming an auxiliary cathode layer on the organic insulating encapsulation layer, wherein the auxiliary cathode layer contacts the cathode layer through the vias.

[0023] In one exemplary embodiment, the fabrication method further includes, prior to forming the organic insulating encapsulation layer:

[0024] An inorganic water and oxygen barrier layer is formed on the cathode layer.

[0025] After forming the organic insulating encapsulation layer, the fabrication method further includes: forming a first via in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer using a wet etching process to expose the inorganic water and oxygen barrier layer; removing the inorganic water and oxygen barrier layer located in the first via to form a second via exposing the cathode layer; and forming an auxiliary cathode layer on the organic insulating encapsulation layer. The auxiliary cathode layer contacts the cathode layer through the first via and the second via.

[0026] In one exemplary embodiment, the water-oxygen barrier layer comprises aluminum oxide.

[0027] Thirdly, this disclosure provides a display device including a display panel as described in the first aspect. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure, and not all of them.

[0029] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements (components or components).

[0030] It should be understood that the accompanying drawings are only schematic, and the dimensions and scale of the elements (components or parts) in the drawings are not necessarily precise.

[0031] Figure 1 A schematic diagram of the planar structure of the display device is provided for this disclosure.

[0032] Figure 2 This is a cross-sectional schematic diagram of a display panel provided in an embodiment of the present disclosure.

[0033] Figure 3 This is a partial schematic diagram of a display panel according to an embodiment of the present disclosure.

[0034] Figure 4 A cross-sectional schematic diagram and a partially enlarged schematic diagram of a display panel provided for another embodiment of this disclosure.

[0035] Figure 5 This is a cross-sectional schematic diagram of a display panel provided in yet another embodiment of the present disclosure.

[0036] Figure 6 This is a flowchart of a method for manufacturing the display device disclosed herein.

[0037] Figure 7 This is a partial flowchart of the manufacturing method of the display device disclosed herein.

[0038] Figure 8 This is another part of the flowchart of the manufacturing method of the display device disclosed herein.

[0039] Figure 9 This is another part of the flowchart of the method for manufacturing the display device disclosed herein. Detailed Implementation

[0040] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0042] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0043] The features and exemplary embodiments of various aspects of this application will now be described in detail. Furthermore, the features, structures, or characteristics described below may be combined in any suitable manner in one or more embodiments.

[0044] This disclosure provides a display device, which may include, but is not limited to, mobile phones, tablets, laptops, desktop computers, terminals, interactive displays, digital audio-visual equipment, IoT devices, etc. Interactive displays may include interactive whiteboards, digital advertising interactive screens, and interactive gaming displays, etc. IoT devices may include smart home devices and smart wearable devices, etc. The display device may include a display panel, which can provide a display interface and touch input to achieve corresponding functions.

[0045] Figure 1This is a schematic diagram of the structure of a display device 100 according to one or more embodiments of the present disclosure.

[0046] The display device 100 can be a regular mobile phone, a feature phone, or a smartphone. A smartphone can be a flat-screen phone, a curved-screen phone, or a flip phone, etc. The display device 100 includes a display panel 10, which can be located at the top, middle, or bottom of the display device 100. The display panel 10 can be used for information display, for example, as a visual information display component. The display panel 10 can also serve as a touch input component, allowing users to operate the display device 100 by touching the display panel 10, for example, for display and input needs during interface navigation and function switching. The display device 100 may also have a housing, in which the display panel 10 is mounted. The housing protects the display panel 10 and reduces the risk of damage from external forces.

[0047] This disclosure discloses a display panel. The display panel includes a substrate, an anode layer, a pixel isolation layer, an organic light-emitting layer, a cathode layer, and an organic insulating encapsulation layer. The anode layer includes a plurality of anode units corresponding to a plurality of pixels, and the plurality of anode units are arrayed on the upper surface of the substrate. The pixel isolation layer is disposed on the upper surface of the substrate and is used to separate the anode units of two adjacent pixels. In a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening for defining a corresponding pixel. The organic light-emitting layer uniformly covers the upper surfaces of the anode layer and the pixel isolation layer. The cathode layer uniformly covers the upper surface of the organic light-emitting layer, and the surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conforming to the pixel opening. The organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure.

[0048] For example, such as Figure 2 As shown, the display panel 10 includes, from bottom to top, a substrate 11, an anode layer 12 and a pixel isolation layer 13 disposed on the substrate 11, an organic light-emitting layer 14, a cathode layer 15, and an organic insulating layer (ILD) 16. The anode layer 12 includes a plurality of anode units, which are distributed in an array on the surface of the substrate 11. The spacing between adjacent anode units is arranged according to actual needs, and the anode units can be made of indium tin oxide (ITO).

[0049] The cathode layer and the anode layer can be made of metals such as gold, silver, copper, iron, tin, lead, hafnium, tungsten, molybdenum, neodymium, titanium, tantalum, aluminum, and zinc, alloys thereof, or combinations thereof. The light-emitting layer can include any known organic electroluminescent material, including but not limited to polymer-based materials, small-molecule-based materials, and dendritic-based materials. The hole transport layer and the electron transport layer can be made of any conventional material, depending on the type of organic electroluminescent material used.

[0050] The pixel isolation layer 13 has a greater thickness in the first direction than the anode layer 12 in the first direction, thus separating adjacent anode units to form an anti-crosstalk isolation wall and prevent crosstalk between the light-emitting layers. Therefore, the organic light-emitting layer 14 and the cathode layer 15, which are uniformly covered along the first direction, have a height difference on the surface of the cathode layer away from the organic light-emitting layer in the first direction after being stacked, forming a step structure conformal to the pixel opening. Specifically, the cathode layer 15 has multiple stepped structures on the surface away from the organic light-emitting layer. The difference in the step structure formed by the stepped structures in the first direction is typically greater than 1 micrometer. The organic insulating encapsulation layer 16 completely covers the cathode layer 15, filling the multiple groove portions formed by the step structure, achieving complete coverage at each corner of the step structure, forming a seamless continuous film layer. The upper surface of the organic insulating encapsulation layer 16 is horizontal. An inkjet printing layer (IPJ) and a chemical vapor deposition layer (CVD) are sequentially stacked on top of the organic insulating encapsulation layer, forming an organic-organic-inorganic encapsulation structure. In this embodiment, the display panel can be an OLED panel, a Mini-LED panel, a Micro-LED panel, etc.

[0051] In this embodiment, the pixel isolation layer is a support pillar, isolation dam, or TFT protrusion disposed between adjacent anode units.

[0052] In this embodiment, acrylic resin is used as the organic insulating encapsulation layer material.

[0053] In the fabrication of high-resolution, large-size, and flexible display panels, high pixel density leads to complex and dense step structures. For example, the dense arrangement of tiny pixels in smartphone screens requires the encapsulation layer to achieve seamless coverage over extremely small step sizes. The substrate serves as a support structure, with its surface-distributed anode layers achieving pixel driving through an array design. The pixel isolation layer extends beyond the height of the anode layer in a direction perpendicular to the substrate surface (the first direction), forming pixel openings and physically isolating adjacent pixels. This design effectively prevents crosstalk between the light-emitting layers. Due to the presence of these pixel openings, a height difference inevitably forms between the top surface of the anode unit and the top surface of the pixel isolation layer. As the organic light-emitting layer and cathode layer are uniformly deposited from bottom to top, the height difference on the side of the cathode layer away from the organic light-emitting layer in the first direction inevitably constitutes a step structure conforming to the pixel openings. In the traditional display panel fabrication process, chemical vapor deposition (CVD) technology, due to its material limitations, has insufficient coverage for high step structures, leading to moisture intrusion through gaps and device failure. The root cause of this problem lies in the poor fluidity and wettability of CVD materials, which cannot effectively fill the step structure formed by the height difference between the anode layer and the pixel isolation layer. This step structure exacerbates the difficulty of covering the encapsulation layer. The presence of this step structure makes it difficult for traditional CVD processes to form a continuous film when covering the cathode layer, resulting in encapsulation defects. The film layer formed by vapor deposition in CVD processes is prone to fractures or uneven thickness in steep sidewalls and recessed areas, thus forming tiny gaps at the discontinuity between the cathode layer surface and the encapsulation layer. These gaps become channels for moisture intrusion, leading to oxidation or even short circuits in the organic light-emitting layer or cathode layer, ultimately causing the display panel to malfunction.

[0054] To address the aforementioned issues, the technical solution proposed in this disclosure employs a display panel structure design based on a leveling organic insulating encapsulation layer and a spin coating process. The leveling organic insulating encapsulation layer's coverage capability is optimized through a spin coating process. Specifically, due to its inherent leveling properties combined with the spin coating process, the organic insulating encapsulation layer, after coating, can naturally flow and fill the recessed areas of the stepped structure using gravity and centrifugal force. This promotes uniform material extension, eliminates local accumulation or gaps, and achieves continuous coverage on the sidewalls and bottom of the stepped structure. Coating with a leveling organic insulating encapsulation layer allows for better adaptation to surfaces with complex morphologies. The continuous coverage of the stepped structure by the organic insulating encapsulation layer effectively blocks the path of moisture intrusion through the sidewalls and bottom of the stepped structure, thus solving the failure problem caused by insufficient encapsulation layer coverage. The leveling organic insulating encapsulation layer improves the flatness of the substrate after encapsulation. Simultaneously, the leveling property of the organic insulating encapsulation layer also provides good ramping performance, increasing its coverage capability for stepped structures.

[0055] The display panel system disclosed herein systematically optimizes the adaptability of the encapsulation layer to high-step structures. The self-filling capability of the leveling material enables it to conform to the geometric features of the step structure, while the uniform film formation characteristics of the spin coating process ensure the stability of the film thickness. For example, at the steep sidewalls at the junction of the pixel isolation layer and the anode layer, the liquid insulating material flows to fill the recessed area, forming a seamless encapsulation layer, significantly improving encapsulation reliability. This process not only eliminates microcracks caused by discontinuous coverage in traditional CVD processes, but also improves the flatness of the top of the organic encapsulation layer through the leveling properties of the material, further reducing the complexity of subsequent processes. In addition, in the application of flexible display panels, the flexibility of the leveling organic insulating encapsulation layer can adapt to the bending deformation of the substrate, avoiding cracking of the encapsulation layer due to mechanical stress, thereby improving the durability of flexible devices.

[0056] Adjusting the encapsulation structure from the traditional CVD1 (inorganic)-IJP (organic)-CVD2 (inorganic) to an ILD (organic)-IJP (organic)-CVD (inorganic) structure makes it easier for the IJP layer to level out during the manufacturing process, forming a flat surface. This, in turn, provides a flatter surface for the CVD layer, which has relatively poor leveling properties, ultimately improving the display effect of the display panel.

[0057] Furthermore, the ILD (organic)-IJP (organic)-CVD (inorganic) structure simplifies the processing technology of the packaging structure. Unlike traditional CVD processes, which require high-temperature deposition, spin coating can be performed at low temperatures, shortening the production cycle.

[0058] In summary, the leveling organic insulating encapsulation layer not only solves the inherent defects of CVD process in terms of coverage of high-step structures, but its material properties can also meet the requirements of spin coating process. By cooperating with spin coating process, it also achieves the continuity and reliability of encapsulation layer.

[0059] In one exemplary embodiment, the organic insulating encapsulation layer has a via formed in a region corresponding to the pixel isolation layer to expose the cathode layer. The display panel further includes an auxiliary cathode layer formed on a surface of the organic insulating encapsulation layer away from the cathode layer and in contact with the cathode layer through the via.

[0060] like Figure 3 , Figure 4 and Figure 5As shown, substrate 11 includes a display area P and a bonding area Q. A metal line layer 17 is disposed on the upper surface of substrate 11 in the bonding area Q, serving as the driving signal line for bonding area Q. One end of the driving signal line is connected to a driving circuit integrated (not shown), and the other end is electrically connected to the display area P. A photosensitive organic insulating encapsulation layer 16 is spin-coated above the metal line layer 17. A first bonding area opening 162 is formed in the organic insulating encapsulation layer 16, exposing the metal lines of bonding area Q to the first bonding area opening 162. A plurality of via structures 164 are formed on the organic insulating encapsulation layer 16. An auxiliary cathode layer 18 is also included above the organic insulating encapsulation layer 16. The auxiliary cathode layer 18 fills the via structures 164 and the first bonding area opening 162, and electrically connects the cathode layer 15 and the metal lines of bonding area Q.

[0061] In one exemplary embodiment, the display panel further includes an inorganic water and oxygen barrier layer disposed between the cathode layer and the organic insulating encapsulation layer, and an auxiliary cathode layer formed on the surface of the organic insulating encapsulation layer away from the cathode layer. The organic insulating encapsulation layer has a first via formed in a region corresponding to the pixel isolation layer, and the inorganic water and oxygen barrier layer has a second via formed communicating with the first via to expose the cathode layer. The auxiliary cathode layer contacts the cathode layer through the first via and the second via.

[0062] like Figure 3 and Figure 6 As shown, an inorganic water-oxygen barrier layer 20 is disposed between the cathode layer 15 and the organic insulating encapsulation layer 16, and simultaneously located between the metal wire layer 17 and the organic insulating encapsulation layer 16 in the bonding region Q. In a display panel where vias need to be formed by wet etching, the inorganic water-oxygen barrier layer 20 between the cathode layer 15 and the encapsulation layer 19 allows the wet etching process to selectively form a first via 191 and a first bonding region opening 162 on the encapsulation layer 19. The inorganic water-oxygen barrier layer 20 prevents further erosion by the wet etching solution. A second via 21 is formed on the inorganic water-oxygen barrier layer 20, corresponding to the first via 191. The second via 21 penetrates the inorganic water-oxygen barrier layer 20 and exposes the cathode layer 15. A second bonding region opening 22 is also formed on the inorganic water-oxygen barrier layer 20, corresponding to the first bonding region opening 162. The second bonding area window 22 penetrates the inorganic water and oxygen barrier layer 20 and exposes the metal wire layer 17 on the bonding area Q. The surface of the metal wire is intact and free of etching.

[0063] In the manufacturing process of display panels, wet etching is widely used to remove organic insulating encapsulation layers in specific areas to form circuit patterns or via structures. However, wet etching solutions (such as strong acid or alkaline solutions) lack sufficient selectivity for etching exposed metal lines (such as aluminum, etc.), leading to accidental corrosion of the metal surface during the wet etching process, causing line breaks, increased impedance, or signal transmission failure. The root cause of this problem is that wet etching solutions cannot selectively remove only the organic insulating encapsulation layer; their chemical components are also highly reactive with metal materials. For example, in bonding areas or high-density wiring areas, metal lines cannot be completely covered by the insulating layer due to functional requirements and are directly exposed to the wet etching solution, resulting in surface erosion. In traditional solutions, if only the organic insulating encapsulation layer is relied upon for protection, its density and chemical stability are insufficient, allowing the wet etching solution to easily penetrate the film layer or seep into the metal surface through micro-defects, causing irreversible damage.

[0064] This disclosure involves depositing an inorganic water-oxygen barrier layer on the cathode layer before the encapsulation layer is laid. The inorganic water-oxygen barrier layer, due to its high density, prevents wet etching solution from penetrating to the metal surface, achieving physical isolation and avoiding direct contact. Inorganic materials generally exhibit better acid / alkali resistance than organic insulating encapsulation layers, thus slowing down the erosion rate of wet etching solution. The inorganic water-oxygen barrier layer directly protects the exposed metal in the bonding area, reducing the occurrence of problems such as wire breaks and impedance increases. The inorganic water-oxygen barrier layer adheres well to the organic insulating encapsulation layer, preventing delamination during wet etching.

[0065] Specifically, an inorganic water-oxygen barrier layer is deposited on the cathode layer to cover the metal lines of the cathode layer and the bonding region. After depositing an encapsulation layer above the inorganic water-oxygen barrier layer, wet etching is performed on the encapsulation layer to create vias. The inorganic water-oxygen barrier layer prevents the wet etching solution from continuously etching towards the cathode layer. After forming the via structure, a second via and a second bonding region window are formed on the inorganic water-oxygen barrier layer, exposing the metal lines of the cathode layer and the bonding region to the auxiliary cathode.

[0066] In an exemplary embodiment, the inorganic water and oxygen barrier layer is an aluminum oxide film (AL2O3).

[0067] In other embodiments, the inorganic water and oxygen barrier layer may also be a silicon nitride film (SiNx).

[0068] In one exemplary embodiment, the organic insulating encapsulation layer is composed of a photosensitive material.

[0069] During the fabrication of display panels, the metal lines in the screen bonding area are exposed because they cannot be covered by the chemical vapor deposition (CVD) layer. Traditional processes require dry etching to form via structures on the CVD layer. However, CVD etching gases have low selectivity for metals, making it difficult to precisely stop etching on the metal surface, resulting in over-etching of the metal lines. Secondly, the etching time required to form vias on the CVD layer is long, especially in the bonding area, where densely packed metal lines cannot be completely covered by the CVD layer due to structural design limitations, further increasing the risk of line breakage during etching.

[0070] To address the aforementioned issues, this disclosure proposes employing a photosensitive organic insulating encapsulation layer. This allows for the direct formation of via structures within the organic insulating encapsulation layer via an exposure and development process. The exposure and development process selectively and directly induces a photochemical reaction in the organic material of a specific target area of ​​the organic insulating encapsulation layer. The unexposed areas are then dissolved by the developing solution, ultimately forming the desired via structure. Due to its chemical selectivity, the exposure and development process precisely removes material from the target area, thus completing the drilling process within the organic insulating encapsulation layer. Consequently, the drilling process eliminates the need for dry etching, completely avoiding the risk of metal lines being exposed to a plasma environment and eliminating damage to the metal caused by etching gases.

[0071] In the process of manufacturing a display panel, the core condition for achieving drilling on an organic insulating encapsulation layer without physical damage to the metal lines lies in utilizing the photosensitivity of the organic insulating encapsulation layer. This allows the drilling process to be completed through exposure and development, and the photochemical reaction occurs only on the organic insulating encapsulation layer, thus eliminating the defects of traditional chemical vapor deposition (CVD) processes in protecting the metal lines in the bonding area.

[0072] In some embodiments, the material of the organic insulating encapsulation layer is polyimide or acrylic resin. Different photosensitive materials can be selected according to different drilling requirements. For example, polyimide can be used as the photosensitive material for via structures with high aspect ratios (e.g., ≥5:1), while acrylic resin can be used as the photosensitive material for via structures with low aspect ratios (e.g., ≥3:1).

[0073] In one exemplary embodiment, the pixel isolation layer includes an inorganic pixel definition layer and isolation pillars located above the inorganic pixel definition layer. The inorganic pixel definition layer is located above the substrate, and the isolation pillars are located above the inorganic pixel definition layer, with the projection of the isolation pillars in a first direction entirely on the inorganic pixel definition layer. Conventional processes use a single material as the isolation layer between pixels, which may result in problems with unsuitable height or shape, leading to breakage or poor contact of the cathode layer during coverage. However, using an inorganic pixel definition layer (PDL) as the base layer, along with isolation pillars, allows the tops of the metal isolation pillars to directly contact the cathode layer, forming a low-resistance conductive path and resolving the dependence of cathode overlap on the evaporation angle. This provides a more uniform cathode layer surface, making continuous coverage of the cathode layer easier during evaporation, reducing line breaks, and thus improving the yield of cathode overlap in the upper conductive process.

[0074] Uneven etching rates can lead to undercutting of the underlying material, forming an inverted trapezoidal structure. This structure can easily create voids or incomplete coverage during subsequent thin film deposition, especially during cathode evaporation, where undercuts can cause poor adhesion. By using metal or inorganic spacers, the etching process can be altered, making it easier to control, reducing undercut formation, and thus avoiding cathode adhesion problems.

[0075] Traditional processes may require specific evaporation angles to ensure that the cathode material can cover a specific area of ​​the isolation layer. However, with the new isolation layer structure, the cathode material can be uniformly covered regardless of the evaporation angle, thus eliminating the need to adjust existing evaporation equipment and saving costs and time.

[0076] For example, the material of the inorganic PDL can be silicon nitride (SiNx) or silicon oxide (SiO2); the metal isolation pillar is a titanium-aluminum-titanium (Ti / Al / Ti) stacked structure, abbreviated as TAT, which can effectively reduce resistance and effectively prevent water vapor penetration and creep.

[0077] In this embodiment, the height of the pixel isolation layer is 1.5 μm to 3 μm in a first direction perpendicular to the substrate, and exceeds the upper surface of the anode layer by 0.8 μm to 2 μm.

[0078] like Figure 7 The diagram shown is a flowchart of a method for manufacturing a display panel according to an embodiment of this application; the method includes:

[0079] Step S1: Provide a substrate.

[0080] The substrate can be flexible, stretchable, foldable, bendable, or rollable, so that the display panel can be flexible, stretchable, foldable, bendable, or rollable. The substrate can be formed from any suitable insulating material that is flexible.

[0081] Step S2: An anode layer is formed on the upper surface of the substrate.

[0082] Specifically, the anode layer includes a plurality of anode units corresponding to a plurality of pixels, and the plurality of anode units are arrayed on the upper surface of the substrate, with any adjacent anode units having the same spacing.

[0083] Step S3: A pixel isolation layer is formed on the upper surface of the substrate.

[0084] Specifically, the pixel isolation layer is used to separate the anode units of two adjacent pixels, and in a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening for defining the corresponding pixel.

[0085] The pixel isolation layer consists of an inorganic pixel definition layer (PDL) and metal isolation pillars. The inorganic PDL material can be silicon nitride (SiNx) or silicon oxide (SiO2); the metal isolation pillars can be a titanium-aluminum-titanium (Ti / Al / Ti) stacked structure. The inorganic pixel definition layer is located above the substrate, and the isolation pillars are located above the inorganic pixel definition layer. The projection of the isolation pillars in the first direction lies entirely on the inorganic pixel definition layer.

[0086] Step S4: Uniformly cover the upper surface of the anode layer and the pixel isolation layer with an organic light-emitting layer.

[0087] Step S5: Uniformly cover the cathode layer on the upper surface of the organic light-emitting layer.

[0088] Specifically, the surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conforming to the pixel opening.

[0089] Step S6: Form an organic insulating encapsulation layer on the upper surface of the cathode layer.

[0090] The organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure.

[0091] Specifically, the step structure has a height difference in the first direction, and the organic insulating encapsulation layer forms a continuous cover on the sidewalls and bottom of the step structure to avoid the formation of pixel opening gaps between the upper surface of the cathode layer and the organic insulating encapsulation layer. This organic insulating encapsulation layer is formed by a spin coating process. Due to the leveling properties of the organic insulating encapsulation layer, it can naturally flow and fill the recessed areas of the step structure after coating, using gravity and centrifugal force, promoting uniform material extension, eliminating local accumulation or gaps, and achieving a continuous cover on the sidewalls and bottom of the step structure.

[0092] In traditional CVD processes, the deposition rate of SiO2 or SiNx is only 0.1 μm / min, and the step coverage cannot be improved by adjusting process parameters. In contrast, spin coating processes can actively adapt to the geometric characteristics of the step by controlling the material leveling and rotation speed. For example, at the same step height of 2 μm, the sidewall coverage of the step structure by the CVD process is less than that by the spin-coated organic insulating encapsulation layer.

[0093] By combining material properties with spin coating technology, the continuity and reliability of the encapsulation layer were also achieved.

[0094] In one exemplary embodiment, such as Figure 8 As shown, the organic insulating encapsulation layer is formed of a photosensitive material, and the manufacturing method of the display panel also includes:

[0095] Step S61: Form vias in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer by an exposure and development process to expose the cathode layer;

[0096] Step S62: An auxiliary cathode layer is formed on the organic insulating encapsulation layer, wherein the auxiliary cathode layer is in contact with the cathode layer through the via.

[0097] Specifically, the organic insulating encapsulation layer uses a photosensitive material (such as photosensitive polyimide or acrylic resin) to cover the surface of the metal wires through a spin-coating process, forming a uniform film layer. Subsequently, an exposure and development process is used to directly and selectively cause a photochemical reaction of the organic material in specific target areas of the organic insulating encapsulation layer. The unexposed areas are then dissolved by a developer, ultimately forming the desired via structure. Due to its chemical selectivity, the exposure and development process precisely removes material from the target areas, avoiding damage to the metal wires caused by physical etching.

[0098] In the manufacturing process of display panels, the photosensitive properties of materials and the synergistic effect of exposure and development processes can effectively avoid the defects in the protection of metal wires in the bonding area that are present in traditional chemical vapor deposition (CVD) processes.

[0099] Dry etching, such as reactive ion etching (RIE), relies on ion bombardment and chemical reactions in plasma to remove material. As the etching depth increases (above 1 μm), the anisotropic etching characteristics of ions result in steep hole walls, making it difficult to adjust the hole wall taper angle.

[0100] For auxiliary cathode filling vias, the steep via walls make it difficult for the auxiliary cathode material to evenly cover the via walls during the filling process. In particular, gaps or cracks are easily formed at the junction of the bottom and sidewalls of the via, resulting in poor conductivity or even wire breakage.

[0101] This disclosure employs drilling vias in an organic encapsulation insulating layer, such as using an exposure and development process to form the vias. Due to the chemical properties of the photoresist, the development process allows for more precise control over the via morphology, including the tape angle. For example, for an organic encapsulation insulating layer 2 μm thick, the exposure and development energy and time are easily adjustable, making the sidewall tilt of the via controllable and creating a smoother transition, which is beneficial for the subsequent ramping, filling, and coverage of the auxiliary cathode within the via.

[0102] In one exemplary embodiment, such as Figure 9 As shown, before forming the organic insulating encapsulation layer, i.e. before step S6, the method for manufacturing the display panel further includes step S51: forming an inorganic water and oxygen barrier layer on the cathode layer.

[0103] After forming the organic insulating encapsulation layer, i.e. after step S6, the method further includes:

[0104] Step S7: Form a first via in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer by wet etching process to expose the inorganic water and oxygen barrier layer.

[0105] Step S8: Remove the inorganic water and oxygen barrier layer located in the first via to form a second via exposing the cathode layer.

[0106] Step S9: An auxiliary cathode layer is formed on the organic insulating encapsulation layer.

[0107] Specifically, the auxiliary cathode layer contacts the cathode layer through the first via and the second via.

[0108] In the manufacturing process of display panels, wet etching is widely used to remove organic insulating encapsulation layers in specific areas to form circuit patterns or via structures. However, wet etching solutions (such as strong acid or alkaline solutions) lack sufficient selectivity for etching exposed metal lines (such as aluminum, etc.), leading to accidental corrosion of the metal surface during the wet etching process, causing line breaks, increased impedance, or signal transmission failure. The root cause of this problem is that wet etching solutions cannot selectively remove only the organic insulating encapsulation layer; their chemical components are also highly reactive with metal materials. For example, in bonding areas or high-density wiring areas, metal lines cannot be completely covered by the insulating layer due to functional requirements and are directly exposed to the wet etching solution, resulting in surface erosion. In traditional solutions, if only the organic insulating encapsulation layer is relied upon for protection, its density and chemical stability are insufficient, allowing the wet etching solution to easily penetrate the film layer or seep into the metal surface through micro-defects, causing irreversible damage.

[0109] This disclosure involves depositing an inorganic water-oxygen barrier layer on the cathode layer before the encapsulation layer is laid. The inorganic water-oxygen barrier layer, due to its high density, prevents wet etching solution from penetrating to the metal surface, achieving physical isolation and avoiding direct contact. Inorganic materials generally exhibit better acid / alkali resistance than organic insulating encapsulation layers, thus slowing down the erosion rate of wet etching solution. The inorganic water-oxygen barrier layer directly protects the exposed metal in the bonding area, reducing the occurrence of problems such as wire breaks and impedance increases. The inorganic water-oxygen barrier layer adheres well to the organic insulating encapsulation layer, preventing delamination during wet etching.

[0110] Specifically, an inorganic water-oxygen barrier layer is deposited on the cathode layer to cover the metal lines of the cathode layer and the bonding area. After depositing an encapsulation layer on top of the inorganic water-oxygen barrier layer, wet etching is performed on the encapsulation layer to create vias. The inorganic water-oxygen barrier layer prevents the wet etching solution from continuously etching towards the cathode layer. After forming the via structure, the inorganic water-oxygen barrier layer is removed, exposing the metal lines of the cathode layer and the bonding area to the via structure.

[0111] In an exemplary embodiment, the inorganic water and oxygen barrier layer is an aluminum oxide film (AL2O3).

[0112] In other embodiments, the inorganic water and oxygen barrier layer may also be a silicon nitride film (SiNx).

[0113] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0114] The display panel and display terminal provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A display panel, characterized in that, include: substrate; An anode layer includes a plurality of anode units corresponding to a plurality of pixels, wherein the plurality of anode units are arrayed on the upper surface of the substrate; A pixel isolation layer is disposed on the upper surface of the substrate and is used to separate the anode units of two adjacent pixels. In a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening for defining the corresponding pixel. An organic light-emitting layer uniformly covers the upper surfaces of the anode layer and the pixel isolation layer; A cathode layer uniformly covers the upper surface of the organic light-emitting layer, wherein the surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conforming to the pixel opening; and An organic insulating encapsulation layer having leveling properties, the organic insulating encapsulation layer completely covering the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure.

2. The display panel according to claim 1, characterized in that, The organic insulating encapsulation layer has vias formed in the region corresponding to the pixel isolation layer to expose the cathode layer. The display panel further includes an auxiliary cathode layer, which is formed on the surface of the organic insulating encapsulation layer away from the cathode layer and contacts the cathode layer through the via.

3. The display panel according to claim 1, characterized in that, Also includes: An inorganic water and oxygen barrier layer disposed between the cathode layer and the organic insulating encapsulation layer; and, An auxiliary cathode layer is formed on the surface of the organic insulating encapsulation layer away from the cathode layer. The organic insulating encapsulation layer has a first via formed in the region corresponding to the pixel isolation layer, the inorganic water and oxygen barrier layer has a second via formed through the first via to expose the cathode layer, and the auxiliary cathode layer contacts the cathode layer through the first via and the second via.

4. The display panel according to claim 1, characterized in that, The organic insulating encapsulation layer is made of photosensitive material.

5. The display panel according to claim 1, characterized in that, The organic insulating encapsulation layer is made of polyimide or acrylic resin.

6. A method for manufacturing a display panel, characterized in that, include, Provide substrate; An anode layer is disposed on the upper surface of the substrate. The anode layer includes a plurality of anode units corresponding to a plurality of pixels, and the plurality of anode units are arrayed on the upper surface of the substrate. A pixel isolation layer is provided on the upper surface of the substrate. The pixel isolation layer is used to separate the anode units of two adjacent pixels. In a first direction, the upper surface of the pixel isolation layer extends beyond the upper surface of the anode layer to form a pixel opening for defining the corresponding pixel. An organic light-emitting layer is uniformly covered on the upper surfaces of the anode layer and the pixel isolation layer; A cathode layer is uniformly covered on the upper surface of the organic light-emitting layer, and the surface of the cathode layer away from the organic light-emitting layer has a height difference in the first direction to form a step structure conforming to the pixel opening; and An organic insulating encapsulation layer is formed on the upper surface of the cathode layer. The organic insulating encapsulation layer has leveling properties and completely covers the surface of the cathode layer away from the organic light-emitting layer to form a continuous coverage on the sidewalls and bottom of the step structure.

7. The manufacturing method according to claim 6, characterized in that, The organic insulating encapsulation layer is formed of a photosensitive material, and the manufacturing method further includes: The cathode layer is exposed by forming vias in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer using an exposure and development process; and An auxiliary cathode layer is formed on the organic insulating encapsulation layer, wherein the auxiliary cathode layer is in contact with the cathode layer through the via.

8. The manufacturing method according to claim 6, characterized in that, Before forming the organic insulating encapsulation layer, the method further includes: forming an inorganic water and oxygen barrier layer on the cathode layer; After forming the organic insulating encapsulation layer, the process further includes: A first via is formed in the region of the organic insulating encapsulation layer corresponding to the pixel isolation layer by a wet etching process to expose the inorganic water and oxygen barrier layer; Remove the inorganic water and oxygen barrier layer located in the first via to form a second via exposing the cathode layer; and, An auxiliary cathode layer is formed on the organic insulating encapsulation layer, wherein the auxiliary cathode layer is in contact with the cathode layer through the first via and the second via.

9. The manufacturing method according to claim 8, characterized in that, The water and oxygen barrier layer comprises aluminum oxide.

10. A display device comprising a display panel as described in any one of claims 1-5.

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