Display panel, manufacturing method thereof and display device

Abstract

The invention relates to a display panel, a manufacturing method thereof and a display device. The display panel comprises a substrate and a pixel definition layer arranged on the substrate. The pixel definition layer comprises a dam and a pixel opening defined by the dam; the dam comprises a side wall close to one side of the pixel opening and a top surface far away from one side of the substrate, and the side wall comprises a first sub-side wall close to the substrate and a second sub-side wall located between the first sub-side wall and the top surface; the display panel further comprises a plurality of microstructures arranged on the second sub side wall and the top surface, and the microstructures have lyophobicity. The problem of device electric leakage caused by upward climbing of the ink material in the pixel opening can be effectively improved or avoided, so that the display quality of the display panel can be improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display panel, a method for manufacturing the same, and a display device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have advantages such as fast response speed, high contrast and wide viewing angle, and are easy to realize flexible display, making them the mainstream product of the next generation of display technology.

[0003] OLED devices have an anode, an organic functional layer, and a cathode sequentially formed on a substrate. The organic functional layer typically includes a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron injection layer (EIL), and an electron transport layer (ETL). These layers are sequentially formed within the pixel aperture using inkjet printing (IJP). Due to limitations in ink materials and processing techniques, the edges of the hole injection layer, hole transport layer, and emitting layer accumulate on the sidewalls of the "bank," forming a sloping structure. Since the sloping heights of the hole injection layer, hole transport layer, and emitting layer are uniform, it is impossible for the upper layer to completely cover the edge of the lower layer. Therefore, the hole injection layer and electron transport layer located on opposite sides of the emitting layer overlap at the sloping points, forming a leakage path and causing a performance degradation in the OLED device. Summary of the Invention

[0004] This application provides a display panel and its manufacturing method, as well as a display device, which can effectively improve or avoid the device leakage problem caused by ink material climbing up the pixel opening, thereby improving the display quality of the display panel.

[0005] To achieve the above objectives, according to a first aspect of this application, a display panel is provided, comprising:

[0006] substrate;

[0007] A pixel definition layer is disposed on the substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam; the dam includes a sidewall near the pixel opening and a top surface away from the substrate;

[0008] The sidewall includes a first sub-sidewall disposed near the substrate and a second sub-sidewall located between the first sub-sidewall and the top surface. The display panel also includes a plurality of microstructures disposed on the second sub-sidewall and the top surface, the microstructures being hydrophobic.

[0009] Optionally, the microstructure is provided in a raised shape on the dam, and the width of the microstructure on the side away from the substrate is greater than the width of the microstructure on the side closer to the substrate.

[0010] Optionally, the microstructure is mushroom-shaped, columnar, dendritic, or screw-shaped.

[0011] Optionally, the diameter of the microstructure in the direction perpendicular to the thickness direction of the display panel ranges from 20 nanometers to 500 nanometers.

[0012] Optionally, the material of the microstructure includes a fluorine-free silane resin material; the silane resin material contains any one or more of polysiloxanes, polysilsesquianes, and small molecule silanes with a carbon number greater than 3 alkane straight chain or side chain.

[0013] Optionally, in the direction in which the second sub-sidewall extends toward the top surface, the second sub-sidewall is divided into multiple hydrophobic regions; the content of hydrophobic material in the microstructure located in the same hydrophobic region is the same, and the content of hydrophobic material in the microstructure located in different hydrophobic regions is different;

[0014] In the direction in which the second sub-sidewall extends toward the top surface, the hydrophobicity of the plurality of hydrophobic regions is gradient-distributed.

[0015] Optionally, at least the dam in the region where the first sub-sidewall is located is hydrophilic.

[0016] According to a second aspect of this application, a method for manufacturing a display panel is provided, comprising the following steps:

[0017] A pixel definition layer is formed on one side of a substrate; the pixel definition layer includes a dam and a pixel opening enclosed by the dam; the dam includes a sidewall near the pixel opening and a top surface away from the substrate, the sidewall including a first sub-sidewall disposed near the substrate and a second sub-sidewall located between the first sub-sidewall and the top surface; and

[0018] Multiple hydrophobic microstructures are fabricated on the second sub-sidewall and the top surface; the material of the microstructures includes a fluorine-free silane resin material.

[0019] Optionally, the raw materials used to fabricate the microstructure include:

[0020] Acrylic resin with a mass fraction of 15%-45%;

[0021] Initiator with a mass fraction of 0.5%-5%;

[0022] Solvents with a mass fraction of 10%-60%;

[0023] Silane materials with a mass fraction of 5%-25%; and

[0024] Additives with a mass fraction of 1%-15%;

[0025] The silane material includes any one or more of hexamethyldisilazane, dodecylsiloxane, hexadecylsiloxane, 4-octyldodecylsiloxane, and polysilsesquiane.

[0026] According to a third aspect of this application, a display device is provided, the display device comprising the display panel described above.

[0027] In the display panel, manufacturing method, and display device of this application embodiment, by providing hydrophobic microstructures on the second sub-sidewall and top surface of the dam, the second sub-sidewall and top surface of the dam become hydrophobic. This prevents ink material printed in the pixel opening from overflowing and improves or avoids ink material climbing up the sidewall of the dam, thereby preventing leakage caused by the film layer printed at the bottom of the pixel opening contacting other film layers, thus improving the display quality of the display panel. Furthermore, by providing multiple microstructures on the second sub-sidewall, the roughness of the hydrophobic surface is increased, thereby reducing the surface energy of the hydrophobic surface, i.e., increasing the hydrophobicity of the hydrophobic surface, enabling the hydrophobic surface to achieve oleophobic function, further improving the problem of ink material climbing up, and thus further improving the leakage problem caused by ink material climbing up. Therefore, this application can effectively improve or avoid the device leakage problem caused by ink material climbing up in the pixel opening by providing multiple microstructures on the second sub-sidewall and top surface of the dam, thereby improving the display quality of the display panel.

[0028] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0031] Figure 1 This is a schematic diagram of the structure of an exemplary OLED display panel provided in this application;

[0032] Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application;

[0033] Figure 3 yes Figure 2 A schematic diagram of the microstructure in [the material].

[0034] Figure 4 This is a schematic diagram of the cross-sectional structure of a dam provided in an embodiment of this application;

[0035] Figure 5 This is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of this application;

[0036] Figure 6 This is a top view of a dam structure provided in an embodiment of this application;

[0037] Figure 7 This is a schematic diagram of the structure of a display device provided in an embodiment of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1 (1') Display panel; 2 (2') Substrate; 2a) Substrate layer; 2b) Driving layer; 3 (3') First electrode layer; 4 (4') Pixel definition layer; 5 (5') Dam; 5a) First sub-dam; 5b) Second sub-dam; 6 (6') Pixel opening; 7 (7') Sidewall; 7a) First sub-sidewall; 7b) Second sub-sidewall; 8) Top surface; 9) Microstructure; 10) Organic functional layer; 10a (10a') Hole injection layer; 10b (10b') Hole transport layer; 10c (10c') Light-emitting layer; 10d (10d') Electron transport layer; 11 (11') Second electrode layer; 12) Anode unit; 13) Liquid-repellent region; 14) Third dam; 15) Fourth dam; 16) Display device; 17) Encapsulation layer; 18) Touch layer; 19) Protective layer; 20) Housing. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0041] Typically, both the organic functional layer and the cathode metal layer in OLED devices are fabricated using a vacuum thermal evaporation process. However, the high cost of vacuum thermal evaporation limits the widespread commercialization of OLED displays. Compared to traditional vacuum thermal evaporation, inkjet printing (IJP) technology offers numerous advantages, including high material utilization, mild process conditions, and more uniform film formation, making it more promising for applications.

[0042] Specifically, IJP technology uses multiple nozzles to drop ink material (or ink) containing dissolved functional materials into predetermined pixel openings, and then obtains a thin film with the desired pattern through drying. On the substrate used in the IJP film deposition process, grooves are usually made to confine the ink material, allowing ink droplets to flow into the grooves. After drying and baking, the ink material shrinks within the confinement area of ​​the grooves to form a thin film.

[0043] Figure 1 This is a schematic diagram of an exemplary OLED display panel 1'. The OLED display panel 1' includes a substrate 2' and a first electrode layer (i.e., anode) 3', a pixel definition layer 4', a hole injection layer (HIL) 10a', a hole transport layer (HTL) 10b', a light-emitting layer (EML) 10c', an electron transport layer (ETL) 10d', and a second electrode layer (i.e., cathode) 11' sequentially disposed on the substrate 2'. The pixel definition layer 4' includes a dam 5' and a pixel opening 6' formed by the dam 5', and the pixel opening 6' is aligned with the first electrode layer 3'. The hole injection layer 10a', hole transport layer 10b', and light-emitting layer 10c' are sequentially formed within the pixel opening 6' by inkjet printing. Due to the different hydrophilicities of different ink materials, for ink materials with better hydrophilicity, the slope on the sidewall 7' of the dam 5' is higher, causing the printed film to form a coffee ring within the pixel opening 6'. For example, the edges of the hole injection layer 10a', hole transport layer 10b', and light-emitting layer 10c' accumulate on the sidewall 7' of the dam 5', forming a ramp structure with consistent climbing height, making it impossible for the upper film layer to completely cover the edge of the lower film layer. Moreover, when the ink ramp of the bottom hole injection layer 10a' is high, the hole injection layer 10a' and the electron transport layer 10d' will overlap at the climbing point, forming a leakage path, which leads to a decrease in the performance of the OLED device.

[0044] To address the aforementioned issues, this application improves the structure of a display panel containing OLED devices. By setting multiple hydrophobic microstructures on the upper half of the sidewall and top surface of the dam of the pixel definition layer, the portion of the dam covered with microstructures exhibits strong hydrophobicity. This effectively confines the ink material within the pixel opening and effectively mitigates or prevents the ink material from climbing up the sidewall of the dam during film formation. This results in a film layer with a more uniform thickness, preventing the edge of the bottom hole injection layer from contacting other film layers above the light-emitting layer. Consequently, this improves or prevents leakage problems caused by ink material climbing up the dam.

[0045] like Figure 2 As shown, this application embodiment provides a display panel 1, which includes a substrate 2 and a pixel definition layer 4 sequentially disposed on the substrate 2. The pixel definition layer 4 is disposed on the substrate 2 and includes a dam 5 and a pixel opening 6 formed by the dam 5. The dam 5 includes a sidewall 7 near the pixel opening 6 and a top surface 8 away from the substrate 2.

[0046] The sidewall 7 includes a first sub-sidewall 7a disposed near the substrate 2 and a second sub-sidewall 7b located between the first sub-sidewall 7a and the top surface 8. The display panel 1 also includes a plurality of microstructures 9 disposed on the second sub-sidewall 7b and the top surface 8. The microstructures 9 are hydrophobic.

[0047] In some embodiments, the display panel 1 further includes an organic functional layer 10 disposed in the pixel opening 6. The organic functional layer 10 is composed of a plurality of sub-film layers, and at least some of the sub-film layers in the organic functional layer 10 are formed by inkjet printing technology. During the inkjet printing process, ink material containing organic functional materials is dripped into the preset pixel opening 6 and at least contacts the first sub-sidewall 7a of the dam 5.

[0048] It should be noted that the aforementioned hydrophobicity refers to a contact angle greater than 90° between the surface of the microstructure 9 and the ink material printed in the pixel opening 6. Hydrophobicity is divided into hydrophobicity and oleophobicity. The microstructure 9 provided in this application embodiment can be either hydrophobic or oleophobic.

[0049] In this embodiment, by providing hydrophobic microstructures 9 on the second sub-sidewall 7b and top surface 8 of the dam 5, the second sub-sidewall 7b and top surface 8 of the dam 5 become hydrophobic. This prevents ink material printed in the pixel opening 6 from overflowing and improves or prevents ink material from climbing up the sidewall 7 of the dam 5. This avoids leakage caused by the film layer printed at the bottom of the pixel opening 6 contacting other film layers, thus improving the display quality of the display panel 1. Furthermore, by providing multiple microstructures 9 on the second sub-sidewall 7b, the roughness of the hydrophobic surface is increased, thereby reducing the surface energy of the hydrophobic surface, i.e., increasing the hydrophobicity of the surface. This allows the hydrophobic surface to achieve oleophobic properties, further improving the problem of ink material climbing up the surface, and consequently, further improving the leakage problem caused by ink material climbing up the surface.

[0050] Therefore, by setting multiple microstructures 9 on the second sub-sidewall 7b and top surface 8 of the dam 5, the embodiments of this application can effectively improve or avoid the device leakage problem caused by the ink material climbing up the pixel opening 6, thereby improving the display quality of the display panel 1.

[0051] It should be noted that oleophobic materials have lower surface energy than hydrophobic materials. Therefore, achieving oleophobicity is more demanding than achieving hydrophobicity, requiring even lower surface energy for the solid material. Methods to reduce surface energy include adding fluorinated materials or increasing the roughness of low-surface-energy surfaces. Although fluorinated materials exhibit excellent hydrophobicity, this superior property relies on strong CF bonds. Most fluorinated materials decompose at high temperatures (e.g., above 260°C), releasing toxic gases such as hydrogen fluoride (HF). Furthermore, the recovery and degradation of fluorinated materials are difficult, leading to environmental accumulation, health risks, and disposal challenges. Moreover, the availability and purification costs of fluorine raw materials are high, and the synthesis process of fluoropolymers is complex, resulting in fluorinated hydrophobic materials being significantly more expensive than traditional hydrophobic materials (such as silicon-based hydrophobic materials).

[0052] Currently, the scientific community is dedicated to developing low-toxicity, biodegradable fluorinated analogs or non-fluorinated alternatives to balance hydrophobic properties and environmental safety. In this application embodiment, by incorporating hydrophobic microstructures 9 on the dam 5, the roughness of the hydrophobic surface is increased, thereby effectively reducing the surface energy of the hydrophobic surface to achieve oleophobic functionality. Therefore, this application embodiment can also use fluorine-free materials to fabricate the microstructures 9, making the material itself hydrophobic. Simultaneously, the increased roughness of the hydrophobic surface due to the microstructures 9 effectively reduces the surface energy of the hydrophobic surface, resulting in an oleophobic effect on the surface of the dam 5 with the microstructures 9. Therefore, this application embodiment can effectively balance hydrophobic properties and environmental safety, while also reducing the manufacturing cost of the display panel 1.

[0053] In some embodiments, the display panel 1 further includes a first electrode layer 3 disposed between the substrate 2 and the organic functional layer 10, and a second electrode layer 11 disposed on the side of the organic functional layer 10 opposite to the first electrode layer 3.

[0054] In some embodiments, the pixel opening 6 is aligned with the first electrode layer 3, and at least a portion of the first electrode layer 3 is exposed in the pixel opening 6. The organic functional layer 10 includes a hole injection layer 10a, a hole transport layer 10b, a light-emitting layer 10c, and an electron transport layer 10d sequentially disposed in the pixel opening 6. At least the hole injection layer 10a, the hole transport layer 10b, and the light-emitting layer 10c can be fabricated using an inkjet printing process.

[0055] Of course, in other embodiments, the organic functional layer 10 may also include an electron injection layer (not shown in the figure) disposed between the electron transport layer 10d and the second electrode layer 11, but is not limited thereto.

[0056] In some embodiments, the first electrode layer is an anode layer, the second electrode layer 11 is a cathode layer, and the second electrode layer 11 can cover the entire pixel definition layer 4 and the organic functional layer 10, but is not limited thereto.

[0057] Understandably, the first electrode layer 3, the organic functional layer 10, and the second electrode layer 11 constitute an OLED device.

[0058] In some embodiments, the substrate 2 includes a substrate layer 2a and a driving layer 2b disposed on the substrate layer 2a.

[0059] In some embodiments, the substrate 2a can be either a flexible substrate or a rigid substrate, and this application does not limit the type of substrate. When the substrate 2a is a flexible substrate, the material of the substrate 2a includes, but is not limited to, polyimide. When the substrate 2a is a rigid substrate, the material of the substrate 2a includes, but is not limited to, glass.

[0060] In some embodiments, the driving layer 2b includes multiple driving circuits for driving the OLED device to emit light. It is understood that the embodiments of this application do not limit the structure of the driving circuits.

[0061] In some embodiments, the first electrode layer 3 is disposed on the side of the driving layer 2b away from the substrate layer 2a, and the first electrode layer 3 is electrically connected to the driving circuit in the driving layer 2b.

[0062] In some embodiments, the first electrode layer 3 includes a plurality of anode units 12. The plurality of anode units 12 are electrically connected to a plurality of drive circuits in a one-to-one configuration.

[0063] In some embodiments, the pixel definition layer 4 is disposed on the side of the driving layer 2b opposite to the substrate layer 2a.

[0064] Specifically, the number of pixel openings 6 in the pixel definition layer 4 is the same as the number of anode units 12 in the first electrode layer 3. Each pixel opening 6 is aligned with an anode unit 12, and at least a portion of the anode unit 12 is exposed in the corresponding pixel opening 6.

[0065] In some embodiments, the dam 5 covers the driving layer 2b and extends to the edge portion covering the anode unit 12, such that the anode unit 12 is partially exposed in the pixel opening 6, but is not limited thereto.

[0066] In some embodiments, such as Figure 2 and Figure 3 As shown, the microstructure 9 is convexly disposed on the dam 5, and in the direction away from the substrate 2, the width of the microstructure 9 on the side away from the substrate 2 is greater than the width of the microstructure 9 on the side close to the substrate 2, making the microstructure 9 have a narrow bottom and wide top structure. The narrow bottom and wide top microstructure 9 is beneficial to increasing the roughness of the hydrophobic surface, thereby further reducing the surface energy of the hydrophobic surface, which in turn is beneficial to enhancing the hydrophobicity of the second sub-sidewall 7b and the top surface 8 on which the microstructure 9 is formed.

[0067] It should be noted that the width of the microstructure 9 refers to the width in the direction perpendicular to the thickness direction of the display panel 1, that is, the diameter in the direction perpendicular to the thickness direction of the display panel 1 as described below.

[0068] In one specific embodiment, the microstructure 9 is mushroom-shaped, columnar, dendritic, or screw-shaped, but is not limited thereto. It is understood that the cross-sectional shape of the columnar microstructure 9 in the thickness direction of the display panel 1 can be an inverted trapezoid, but is not limited thereto.

[0069] It should be noted that, due to the more complex structure of dendritic microstructures, which are equivalent to integrating multiple mushroom-shaped, columnar, or screw-shaped microstructures, dendritic microstructures have a larger specific surface area, which can increase the roughness of the hydrophobic surface to a greater extent, thereby enhancing the hydrophobicity to a greater extent.

[0070] In some embodiments, the diameter of the microstructure 9 in the direction perpendicular to the thickness direction of the display panel 1 ranges from 20 nanometers to 500 nanometers. For example, when the display panel 1 is placed on a horizontal surface, the thickness direction of the display panel 1 is perpendicular to the horizontal direction, and the diameter of the microstructure 9 in the horizontal direction ranges from 20 nanometers to 500 nanometers. By controlling the diameter of the microstructure 9, the number of microstructures 9 can be increased more effectively while ensuring that the fabrication process is easy to implement, thereby ensuring a high surface roughness of the hydrophobic surface.

[0071] In some embodiments, the material of the microstructure 9 comprises a fluorine-free silane resin material, and the silane resin material is hydrophobic, for example, it is hydrophobic. Compared with fluorine-containing hydrophobic materials, fluorine-free silane resin materials are easier to obtain, more environmentally friendly, and help reduce material and manufacturing costs.

[0072] In one specific embodiment, the silane resin material contains any one or more of polysiloxanes, polysilsesquianes, and small molecule silanes having a carbon atom number greater than 3 linear or side chains of alkane, but is not limited thereto.

[0073] Understandably, the hydrophobic component in silane resin materials is a polysiloxane, polysilsesquialkane, or small molecule silane with a straight chain or side chain of alkane having more than 3 carbon atoms.

[0074] It should be noted that small molecule silanes refer to silanes with a molecular weight of less than 1000.

[0075] In some embodiments, a double-layer or multi-layer sub-dam structure is designed based on the slurry height and slurry degree on the sidewall 7 of the dam 5.

[0076] For example, the dam 5 includes a first sub-dam 5a and a second sub-dam 5b stacked on the substrate 2. The first sub-sidewall 7a is the sidewall of the first sub-dam 5a near the pixel opening 6, and the second sub-sidewall 7b is the sidewall of the second sub-dam 5b near the pixel opening 6. The first sub-sidewall 7a and the second sub-sidewall 7b are located on the same plane or curved surface. The first sub-dam 5a and the second sub-dam 5b can be manufactured independently or integrally formed.

[0077] In some embodiments, at least the dam 5 in the region where the first sub-sidewall 7a is located is hydrophilic.

[0078] In other words, when the dam 5 is composed of the first sub-dam 5a and the second sub-dam 5b, the first sub-sidewall 7a in the lower half is hydrophilic, while the second sub-sidewall 7b with microstructure 9 in the upper half is hydrophobic. This design allows the second sub-sidewall 7b with microstructure 9 of the second sub-dam 5b to be hydrophobic when printing the hole injection layer 10a ink material in the pixel opening 6, so as to prevent ink material overflow and prevent ink material from climbing up the sidewall 7 of the dam 5. The first sub-sidewall 7a of the first sub-dam 5a is hydrophilic so that the ink material can be fully spread, thereby obtaining a hole transport layer 10b with uniform film thickness, improving or avoiding the risk of leakage caused by the edge of the hole transport layer 10b climbing up the sidewall 7 of the dam 5.

[0079] In some embodiments, the distance between the boundary between the first sub-sidewall 7a and the second sub-sidewall 7b and the first electrode layer 3 is greater than or equal to 30 nanometers. Of course, the boundary between the first sub-sidewall 7a and the second sub-sidewall 7b is determined according to the film thickness of each printed sub-film layer in the organic functional layer 10.

[0080] In some embodiments, the first sub-dam 5a and the second sub-dam 5b are made of the same material, both of which are highly hydrophilic materials. For example, the material of dam 5 is selected from acrylic resin, phenolic resin, epoxy resin, etc., such as at least one of polymethyl methacrylate (PMMA) and polyhydroxystyrene (PHS).

[0081] like Figure 4 As shown, if it is necessary to design the hydrophobicity of the sidewall 7 of the dam 5 to exhibit a gradient distribution with the height of the sidewall 7 remaining constant, the number of layers of the second sub-dam 5b can be increased, and the content of hydrophobic or oleophobic components in the microstructure 9 on the surface of each layer of the second sub-dam 5b can be adjusted in a gradient manner. It can be understood that when there are multiple layers of the second sub-dam 5b, the side of the multiple second sub-dams 5b closest to the pixel opening 6 is the second sub-sidewall 7b, and the side of the uppermost second sub-dam 5b facing away from the substrate 2 is the top surface 8.

[0082] For example, such as Figure 4 As shown, in the direction extending from the second sub-sidewall 7b toward the top surface 8, the second sub-sidewall 7b is divided into multiple hydrophobic regions 13 (each hydrophobic region 13 corresponds to a second sub-dam 5b); the content of hydrophobic material in the microstructure 9 located within the same hydrophobic region 13 is the same, and the content of hydrophobic material in the microstructure 9 located in different hydrophobic regions 13 is different. In the direction extending from the second sub-sidewall 7b toward the top surface 8, the hydrophobicity of the multiple hydrophobic regions 13 exhibits a gradient distribution.

[0083] In one specific embodiment, the hydrophobicity of the plurality of hydrophobic regions 13 increases sequentially in the direction extending from the second sub-sidewall 7b toward the top surface 8, but is not limited thereto. This design allows the strength of the hydrophobicity of the hydrophobic surfaces on the second sub-sidewall 7b at different heights of the dam 5 to be adjusted according to the different hydrophilicity of the ink material to be printed, so that the film thickness of each printed film layer is relatively more uniform.

[0084] In some embodiments, when there are multiple layers of the second sub-dam 5b, the material of each second sub-dam 5b can be the same as that of the first sub-dam 5a, and the first sub-dam 5a and the multiple second sub-dams 5b can be integrally formed. This design can reduce the manufacturing difficulty of the dam 5, thereby saving manufacturing costs.

[0085] It is understandable that since the material of the dam 5 is hydrophilic, the second sub-sidewall 7b is also hydrophilic. However, since the second sub-sidewall 7b is provided with multiple hydrophobic microstructures 9, the hydrophobic surface formed by the microstructures 9 and the second sub-sidewall 7b is hydrophobic.

[0086] In some embodiments, the thickness of the dam 5 is 0.2 micrometers to 1.5 micrometers, and the specific thickness is designed according to the thickness of the printed film layer.

[0087] In some embodiments, the dam 5 can be fabricated using photolithography, and the dam 5 can be a linear dam, a matrix dam, or a circular dam, etc., which are not limited in this application.

[0088] It should be noted that matrix-type dikes are generally arranged in an array, consisting of multiple first and second dikes. The first and second dikes enclose multiple pixel openings. The first and second dikes are usually strip-shaped structures, extending along a specific direction and intersecting each other to form a matrix-like shape. Linear dikes are dikes set along the row or column direction. There are usually no dikes between pixel light-emitting units of the same color, but only linear dikes are set between pixel light-emitting units of different colors to separate them. Circular dikes are set around circular pixel openings, usually in a circular or near-circular annular structure, used to define circular sub-pixel regions.

[0089] For straight embankments, microstructures can be installed on the embankments along the row direction and / or on the embankments along the column direction, depending on the characteristics of the ink material. That is, the aforementioned microstructures can be installed on the sidewalls of any side of the embankment 5, or on one or more sidewalls of the embankment, and the microstructures can be arranged according to actual needs.

[0090] Understandably, compared to linear dams, matrix dams can precisely define each sub-pixel area, effectively preventing the mixing of luminescent materials between adjacent pixels. This helps improve the independence of pixel luminescence and the accuracy of displayed colors, making them more suitable for inkjet printing processes, allowing ink to accurately drip into pixel pits to form organic functional layers.

[0091] like Figure 5 As shown, this application embodiment also provides a method for manufacturing the display panel described in the foregoing embodiment, including steps S501 and S502.

[0092] S501: A pixel definition layer is formed on one side of the substrate; the pixel definition layer includes a dam and a pixel opening formed by the dam; the dam includes a sidewall near the pixel opening and a top surface away from the substrate, the sidewall including a first sub-sidewall disposed near the substrate and a second sub-sidewall located between the first sub-sidewall and the top surface.

[0093] Specifically, the structure of the pixel definition layer formed in this step is described in the foregoing embodiments and will not be repeated here.

[0094] S502: Multiple hydrophobic microstructures are fabricated on the second sub-sidewall and top surface; the materials of the microstructures include fluorine-free silane resin materials.

[0095] Specifically, the structural characteristics of the microstructure formed in this step are described in the foregoing embodiments and will not be repeated here.

[0096] In one specific embodiment, in step S502, the raw material for fabricating the microstructure is a resin composition, and the resin composition includes the following components:

[0097] Acrylic resin with a mass fraction of 15%-45%;

[0098] Initiator with a mass fraction of 0.5%-5%;

[0099] Solvents with a mass fraction of 10%-60%;

[0100] Silane materials with a mass fraction of 5%-25%; and

[0101] Additives with a mass fraction of 1%-15%.

[0102] In some embodiments, the silane material in the resin composition includes, but is not limited to, any one or more of hexamethyldisilazane, dodecylsiloxane, hexadecylsiloxane, 4-octyldodecylsiloxane and polysilsesquioxane.

[0103] In some embodiments, the acrylic resin is selected from at least one of polymethyl methacrylate and its derivatives. Alternatively, the acrylic resin is selected from polymers of the following monomers: acrylic acid, methacrylic acid, crotonic acid, mono(2-(acryloyloxy)ethyl)phthalate, mono(2-(methacryloyloxy)ethyl)phthalate, N-(carboxyphenyl)maleimide, N-(carboxyphenyl)methacrylamide, N-(carboxyphenyl)acrylamide, hydroxystyrene, N-(hydroxyphenyl)acrylamide, N-(hydroxyphenyl)methacrylamide, N-(hydroxyphenyl)maleimide, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 5-acryloyloxy-6-hydroxynorbornen-2-carboxy-6-lactone, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 5-methacryloyloxy-6-hydroxynorbornen-2-carboxy-6-lactone, 2-aminoethyl acrylate, and 2-aminomethyl methacrylate, but not limited thereto.

[0104] In some embodiments, the initiator is selected from at least one of thioonium salts, iodonium salts, and N-hydroxysuccinate sulfonates, but is not limited thereto.

[0105] In some embodiments, the solvent is selected from at least one of propylene glycol methyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), methanol, ethanol, propanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, tetrahydrofuran, but is not limited thereto.

[0106] In some embodiments, the additive includes, but is not limited to, at least one of surfactants, stabilizers, antioxidants, defoamers, adhesion promoters, and leveling agents.

[0107] In some embodiments, in step S502, the microstructure can be formed sequentially through vapor deposition, curing, and etching processes. For example, a layer of the above-mentioned resin composition is first vapor-deposited onto the surface of the dam, then ultraviolet (UV) curing or thermal curing is performed, and finally a microstructure that is wider at the top and narrower at the bottom is formed by photolithography or plasma etching. The distribution of the microstructure on the second sub-sidewall and top surface of the dam is determined by the design of the mask in the etching process.

[0108] Specifically, the manufacturing method further includes the following steps:

[0109] The hole injection layer, hole transport layer and light emission layer are sequentially formed in the pixel opening using inkjet printing technology.

[0110] In some embodiments, the manufacturing method further includes the following steps:

[0111] An electron transport layer and a second electrode layer are sequentially formed in the pixel aperture using a vapor deposition process. The electron transport layer is located on the side of the light-emitting layer opposite to the hole transport layer.

[0112] Specifically, the descriptions of the hole injection layer, hole transport layer, light emission layer, electron transport layer, and second electrode layer are the same as those in the foregoing embodiments and will not be repeated here.

[0113] Of course, in other embodiments, the electron transport layer can also be fabricated using inkjet printing, and this application does not limit this to that.

[0114] This application describes in detail the fabrication process of dams and microstructures in three or more of the aforementioned display panels through Examples 1 to 3.

[0115] Example 1

[0116] The fabrication process of the aforementioned display panel's dam and microstructure is as follows:

[0117] A matrix-shaped or circular dam with a thickness of 0.5 micrometers is fabricated on a substrate with a first electrode layer using photolithography.

[0118] A first resin composition is prepared, comprising 25 wt% acrylic resin, 2 wt% N-hydroxysuccinate sulfonate, 55 wt% propylene glycol methyl ether acetate (PGMEA), 8 wt% dodecylsiloxane, and 10 wt% hexadecylsiloxane; and

[0119] A first resin composition with a thickness of 500 nanometers was vapor-deposited on the dam, cured by UV, and then plasma-etched to obtain a mushroom-shaped microstructure.

[0120] Understandably, wt% refers to mass percentage.

[0121] Specifically, in the first resin composition, N-hydroxysuccinate sulfonate is used as an initiator, propylene glycol methyl ether acetate is used as a solvent, and dodecylsiloxane and hexadecylsiloxane are used as silane materials. The range of acrylic resins is described above and will not be repeated here.

[0122] In Example 1, the distribution of the microstructure on the sidewall of the dam is limited by the film thickness of the hole injection layer. Specifically, the microstructure can be set at a height of 50 nm or above the first electrode layer on the sidewall of the dam.

[0123] Example 2

[0124] Another process for fabricating the aforementioned display panel's dams and microstructures is as follows:

[0125] Multiple third dams with a thickness of 1.2 micrometers and extending along a first direction are fabricated on a substrate on which a first electrode layer is formed using photolithography.

[0126] Multiple fourth dams with a thickness of 0.5 micrometers and extending along a second direction are fabricated on a substrate on which a first electrode layer is formed using photolithography. The first direction and the second direction are perpendicular to each other, and any fourth dam is located between two adjacent third dams.

[0127] A second resin composition is prepared, comprising 20 wt% of 1,1-methoxy-2-propanol, 49.8 wt% of propylene glycol methyl ether acetate, 0.2 wt% of methyl isobutyl ketone, 20 wt% of acrylic resin, 4 wt% of 4-octyldodecylsiloxane, and 6 wt% of polysilsesquiane; and

[0128] A second resin composition with a thickness of 300 nanometers was vapor-deposited on the fourth dam, and then plasma-etched after thermosetting to obtain a mushroom-shaped microstructure.

[0129] Specifically, such as Figure 6 As shown, the third dam 14 and the fourth dam 15 are arranged intersecting each other, for example, perpendicular to each other. The materials of the third dam 14 and the fourth dam 15 can be the same, but are not limited to this.

[0130] It can be understood that, in this embodiment, the microstructure is only set on the fourth dam, and not on the third dam.

[0131] Specifically, in the second resin composition, the acrylic resin is a polymer of N-(carboxyphenyl)methacrylamide monomer, 1,1-methoxy-2-propanol and propylene glycol methyl ether acetate are solvents, methyl isobutyl ketone is an initiator, and 4-octyldodecylsiloxane and polysilsesquiane are silane materials.

[0132] Specifically, in embodiment 2, the distribution position of the microstructure on the side wall of the dam is limited according to the film thickness of the hole injection layer. Specifically, the microstructure can be set in the area at a height of 50nm or above the first electrode layer on the side wall of the dam.

[0133] Example 3

[0134] Another process for fabricating the aforementioned display panel's dams and microstructures is as follows:

[0135] A matrix-shaped or circular dam with a thickness of 0.8 micrometers is fabricated on a substrate with a first electrode layer using photolithography.

[0136] A third resin composition is prepared, comprising 25 wt% of 1,1-methoxy-2-propanol, 42.7 wt% of propylene glycol methyl ether acetate, 0.3 wt% of methyl isobutyl ketone, 20 wt% of acrylic resin, 4 wt% of dodecylsiloxane, 6 wt% of hexamethyldisilazane and 2 wt% of hexadecyltrimethylammonium bromide (CTAB).

[0137] A 200nm thick layer of a third resin composition was vapor-deposited onto the dam, cured with UV, and then subjected to plasma etching to obtain a mushroom-shaped microstructure; and

[0138] The CTAB in the mushroom-shaped microstructure was washed away with acid (e.g., nitric acid) to obtain a dendritic microstructure.

[0139] Specifically, in the third resin composition, 1,1-methoxy-2-propanol and propylene glycol methyl ether acetate are solvents, methyl isobutyl ketone is an initiator, dodecylsiloxane and hexamethyldisilazane are silane materials, CTAB is an additive, and the acrylic resin can be the same as the acrylic resin in Example 1 or Example 2, but is not limited thereto.

[0140] Specifically, in embodiment 3, the distribution position of the microstructure on the side wall of the dam is limited according to the film thickness of the hole injection layer. Specifically, the microstructure can be set in the area at a height of 30nm or above the first electrode layer on the side wall of the dam.

[0141] In the pixel opening enclosed by the dam prepared in Example 1, Example 2, or Example 3, the hole injection layer 10a, hole transport layer 10b, and light-emitting layer 10c prepared by inkjet printing technology are as follows: Figure 2 As shown. Comparison Figure 1 and Figure 2 It is understood that by setting microstructures 9 on the upper half surface of the dam 5, this application can effectively prevent the edges of the hole injection layer 10a and the hole transport layer 10b from climbing up along the side wall 7 of the dam 5 to contact the edge of the light-emitting layer 10c. This can effectively improve or prevent the formation of leakage paths, thereby effectively improving or preventing leakage problems caused by ink material climbing, and thus improving the display quality of the display panel 1.

[0142] like Figure 7 As shown, this application embodiment also provides a display device 16, which includes the display panel 1 described in the foregoing embodiment.

[0143] In some embodiments, the display panel 1 further includes an encapsulation layer 17 covering the second electrode layer 11. The encapsulation layer 17 may be a thin film encapsulation layer, but is not limited thereto.

[0144] In some embodiments, the display device 16 further includes a touch layer 18 disposed on the light-emitting side of the display panel 1 and a protective layer 19 disposed on the side of the touch layer 18 facing away from the display panel 1, wherein the protective layer 19 includes, but is not limited to, ultra-thin glass.

[0145] In some embodiments, the display device 16 further includes a housing 20 disposed on the back and sides of the display panel 1 for protecting the display panel 1.

[0146] In this embodiment, by setting multiple microstructures 9 on the second sub-sidewall 7b and top surface 8 of the dam 5, the leakage problem caused by ink material climbing upward can be effectively improved or avoided, thereby improving the display quality of the display device 16.

[0147] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0148] 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.

[0149] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0150] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A display panel, characterized in that, include: substrate; A pixel definition layer is disposed on the substrate; The pixel definition layer includes a dam and a pixel opening enclosed by the dam; The dam includes a sidewall near the pixel opening and a top surface away from the substrate; The sidewall includes a first sub-sidewall disposed near the substrate and a second sub-sidewall located between the first sub-sidewall and the top surface. The display panel also includes a plurality of microstructures disposed on the second sub-sidewall and the top surface, the microstructures being hydrophobic.

2. The display panel according to claim 1, characterized in that, The microstructure is arranged in a raised shape on the dam, and the width of the microstructure on the side away from the substrate is greater than the width of the microstructure on the side closer to the substrate.

3. The display panel according to claim 2, characterized in that, The microstructures are mushroom-shaped, columnar, dendritic, or screw-shaped.

4. The display panel according to claim 2, characterized in that, The diameter of the microstructure in the direction perpendicular to the thickness direction of the display panel ranges from 20 nanometers to 500 nanometers.

5. The display panel according to claim 1, characterized in that, The microstructure is made of fluorine-free silane resin material; The silane resin material contains any one or more of polysiloxanes, polysilsesquianes, and small molecule silanes with a carbon atom number greater than 3, either in a straight chain or a side chain.

6. The display panel according to any one of claims 1 to 5, characterized in that, In the direction extending from the second sub-sidewall toward the top surface, the second sub-sidewall is divided into multiple hydrophobic regions; the content of hydrophobic material in the microstructure located within the same hydrophobic region is the same, and the content of hydrophobic material in the microstructure located in different hydrophobic regions is different; In the direction in which the second sub-sidewall extends toward the top surface, the hydrophobicity of the plurality of hydrophobic regions is gradient-distributed.

7. The display panel according to any one of claims 1 to 5, characterized in that, At least the dam in the region where the first sub-sidewall is located is hydrophilic.

8. A method for manufacturing a display panel, characterized in that, Includes the following steps: A pixel definition layer is formed on one side of a substrate; the pixel definition layer includes a dam and a pixel opening enclosed by the dam; the dam includes a sidewall near the pixel opening and a top surface away from the substrate, the sidewall including a first sub-sidewall disposed near the substrate and a second sub-sidewall located between the first sub-sidewall and the top surface; as well as Multiple hydrophobic microstructures are fabricated on the second sub-sidewall and the top surface; the material of the microstructures includes a fluorine-free silane resin material.

9. The method for manufacturing a display panel according to claim 8, characterized in that, The raw materials for making the microstructure include: Acrylic resin with a mass fraction of 15%-45%; Initiator with a mass fraction of 0.5%-5%; Solvents with a mass fraction of 10%-60%; Silane materials with a mass fraction of 5%-25%; and Additives with a mass fraction of 1%-15%; The silane material includes any one or more of hexamethyldisilazane, dodecylsiloxane, hexadecylsiloxane, 4-octyldodecylsiloxane, and polysilsesquiane.

10. A display device, characterized in that, Includes the display panel as described in any one of claims 1-7.

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