Display panel, preparation method of display panel and display device

Abstract

The invention discloses a display panel, a preparation method of the display panel and a display device. The display panel comprises a substrate, a light-emitting functional layer and an optical film layer, the light-emitting functional layer is located on one side of the substrate and comprises a plurality of light-emitting units. The optical film layer is located on the light-emitting side of the light-emitting functional layer and comprises a first film layer, a first opening is defined by the first film layer, and the orthographic projection of the first opening on the substrate and the orthographic projection of the light-emitting unit on the substrate are at least partially overlapped; wherein the first film layer comprises a first sub-layer and a second sub-layer, the second sub-layer comprises a main body part and an extension part which are connected with each other, the main body part is located on the side, away from the light-emitting functional layer, of the first sub-layer, and the extension part covers at least part of the side wall, facing the first opening, of the first sub-layer. The light emitting efficiency and the use performance of the display panel can be improved.

Description

Technical Field

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

[0002] OLED (Organic Light-Emitting Diode) devices have become the next generation display technology with great competitiveness and development prospects due to their advantages such as all-solid-state structure, high brightness, full viewing angle, fast response speed, and flexible display.

[0003] However, the performance of current OLED display products needs to be improved. Summary of the invention

[0004] The embodiments of the present application provide a display panel, a method for manufacturing a display panel, and a display device, aiming to improve the performance of the display panel.

[0005] An embodiment of the first aspect of the present application provides a display panel, comprising a substrate, a light-emitting functional layer and an optical film layer; the light-emitting functional layer is located on one side of the substrate and comprises a plurality of light-emitting units; the optical film layer is located on the light-emitting side of the light-emitting functional layer, the optical film layer comprises a first film layer, the first film layer is enclosed to form a first opening, the orthographic projection of the first opening on the substrate and the orthographic projection of the light-emitting unit on the substrate at least partially overlap; wherein the first film layer comprises a first sublayer and a second sublayer, the second sublayer comprises a main body portion and an extension portion connected to each other, the main body portion is located on the side of the first sublayer away from the light-emitting functional layer, and the extension portion covers at least a portion of the side wall of the first sublayer facing the first opening.

[0006] According to the implementation of the first aspect of the present application, the first sublayer includes a bottom surface facing the light-emitting functional layer, the extension portion includes a first side surface facing the first opening, and the angle between the first side surface and the bottom surface is θ1, θ1 is an acute angle and is greater than or equal to 45°.

[0007] According to any of the aforementioned embodiments of the first aspect of the present application, the cross-section of the extension portion gradually increases in a direction away from the light-emitting functional layer.

[0008] According to any of the aforementioned embodiments of the first aspect of the present application, the first sublayer also includes a second side facing the first opening, and the extension portion also includes a third side facing the second side, and the third side is arranged in contact with the second side.

[0009] According to any of the aforementioned embodiments of the first aspect of the present application, the included angle between the second side surface and the bottom surface is θ2, and θ1>θ2.

[0010] According to any of the aforementioned embodiments of the first aspect of the present application, 50°≤θ1≤88°.

[0011] According to any of the aforementioned embodiments of the first aspect of the present application, 60°≤θ1≤88°.

[0012] According to any of the aforementioned embodiments of the first aspect of the present application, the orthographic projection of the first sub-layer on the substrate is located within the orthographic projection of the second sub-layer on the substrate.

[0013] According to any of the aforementioned embodiments of the first aspect of the present application, along a direction perpendicular to the substrate, the average thickness of the first sublayer is H1, and the average thickness of the second sublayer is H2, wherein 0.5 micrometers ≤ H1 ≤ 1.5 micrometers, and 1.0 micrometers ≤ H2 ≤ 2.0 micrometers.

[0014] According to any of the aforementioned embodiments of the first aspect of the present application, the material of the first sublayer is the same as the material of the second sublayer; or, the photosensitivity of the first sublayer is higher than the photosensitivity of the second sublayer; or, the development speed of the second sublayer is lower than the development speed of the first sublayer.

[0015] According to any of the aforementioned embodiments of the first aspect of the present application, the optical film layer also includes a second film layer, which is arranged on the side of the first film layer away from the light-emitting functional layer and fills the first opening. The refractive index of the first film layer is N1, and the refractive index of the second film layer is N2, wherein N1<N2.

[0016] According to any of the aforementioned embodiments of the first aspect of the present application, the difference between the refractive index of the second film layer and the refractive index of the first film layer satisfies: 0.18≤N2-N1≤0.35.

[0017] According to any of the aforementioned embodiments of the first aspect of the present application, the refractive index of the first film layer satisfies: 1.37≤N1≤1.5; and / or the refractive index of the second film layer satisfies: 1.55≤N2≤1.85.

[0018] The embodiment of the second aspect of the present application further provides a method for preparing a display panel, including:

[0019] A first sub-initial layer and a second sub-initial layer located on one side of the first sub-initial layer are formed, wherein the first sub-initial layer and the second sub-initial layer enclose a first opening, the first sub-initial layer has a corner at one end facing the first opening and away from the second sub-initial layer, and the second sub-initial layer has a protrusion relative to the first sub-initial layer in a direction perpendicular to its thickness;

[0020] The second initial sub-layer is baked so that the protrusions collapse to cover the corners.

[0021] According to an embodiment of the second aspect of the present application, before the step of forming the first sub-initial layer and the second sub-initial layer located on one side of the first sub-initial layer, the preparation method includes:

[0022] Covering the entire surface of one side of the substrate with a first initial layer and a second initial layer in sequence;

[0023] The first initial layer and the second initial layer are patterned so that the first initial layer forms a first sub-initial layer and the second initial layer forms a second sub-initial layer.

[0024] According to any of the aforementioned embodiments of the second aspect of the present application, the step of patterning the first initial layer and the second initial layer includes:

[0025] Performing exposure and development processes on the first initial layer and the second initial layer to form a first opening;

[0026] The developing speed of the second initial layer is lower than that of the first initial layer, and / or the photosensitivity of the first initial layer is higher than that of the second initial layer.

[0027] According to any of the aforementioned embodiments of the second aspect of the present application, the material of the second initial layer is the same as the material of the first initial layer, and the step of patterning the first initial layer and the second initial layer comprises:

[0028] performing an exposure and development process on the first region of the first initial layer;

[0029] performing an exposure and development process on the second region of the second initial layer;

[0030] The orthographic projection of the second area on the substrate is located within the orthographic projection of the first area on the substrate.

[0031] According to any of the aforementioned embodiments of the second aspect of the present application, in a plane perpendicular to the thickness direction of the display panel, the average width of the second region is D2, and the average width of the first region is D1, wherein 0.5 micrometers ≤ D1-D2 ≤ 3 micrometers.

[0032] According to any of the aforementioned embodiments of the second aspect of the present application, 0.5 micrometers ≤ D1-D2 ≤ 1.5 micrometers.

[0033] An embodiment of the third aspect of the present application further provides a display device, comprising the display panel provided by any of the embodiments of the first aspect.

[0034] In the display panel provided in the embodiment of the present application, the first film layer includes a two-layer structure, and the extension portion covers at least a portion of the side wall of the first sub-layer facing the first opening. Even if there is a chamfered structure on the side of the first sub-layer facing the first opening, the second sub-layer covers the chamfer of the first sub-layer to reduce the refraction of the chamfer of the first sub-layer on the outgoing light, and the loss of the outgoing light caused by the chamfer is reduced. This can improve the reflection effect of the first film layer on large-angle outgoing light, and emit more light to the positive viewing angle, thereby improving the light output efficiency and performance of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features.

[0036] Figure 1 It is a schematic diagram of the local structure of a low-refractive film layer in the related art;

[0037] Figure 2 is a structural schematic diagram of a display panel provided by an embodiment of the present application;

[0038] Figure 3 yes Figure 2 Partial cross-sectional view at AA in the middle;

[0039] Figure 4 is a schematic diagram of a partial cross-sectional structure of a first film layer in a display panel provided by an embodiment of the present application;

[0040] Figure 5 It is a schematic structural diagram of a first sub-initial layer and a second sub-initial layer in a process of preparing a display panel provided by an embodiment of the present application;

[0041] Figure 6 It is a schematic diagram of a manufacturing process of a display panel provided in one embodiment of the present application.

[0042] Description of reference numerals:

[0043] 1. Substrate;

[0044] 2. Pixel definition layer;

[0045] 3. Light-emitting functional layer; 31. Light-emitting unit;

[0046] 4. Encapsulation layer;

[0047] 5, optical film layer; 51, first film layer; 511, first sublayer; 512, second sublayer; 512a, main body; 512b, extension; 52, second film layer; 50, first opening; 500, bottom surface; 501, first side surface; 502, second side surface; 503, third side surface;

[0048] 100, first sub-initial layer; 110, corner; 120, first region; 200, second sub-initial layer; 210, protrusion; 220, second region. DETAILED DESCRIPTION

[0049] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating examples of the present application. In the accompanying drawings and the following description, at least part of the known structures and technologies are not shown to avoid unnecessary ambiguity in the present application; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0050] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0051] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the embodiments of the present application. In the description of the present application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0052] In the related art, the display panel often has outgoing light that is emitted laterally rather than from the front viewing angle, which makes the light output efficiency of the display panel low. MLA (Micro Lens Array) is a technology that focuses and enhances light through tiny lenses. MLA does not emit light directly, but uses the physical properties of the lens to focus and collimate light from other light sources (such as OLED pixels), thereby improving the brightness and clarity of the picture. By using a patterned low-refractive film layer in combination with a high-refractive film layer around the MLA pixel, the physical phenomenon that there is a total reflection angle when light enters from a high-refractive to a low-refractive light is used to force more light to be diverted from a large angle to the front viewing angle, thereby improving the light output efficiency. However, although MLA can improve the light output efficiency, due to the unsatisfactory actual contour of the MLA, such as Figure 1As shown, there is a small chamfer 110' at the bottom of the profile of the low-refractive film layer 100', which will cause a considerable portion of light to be refracted to other positions, failing to achieve a total reflection effect, failing to effectively improve the front-view light output, and having a low light output efficiency, affecting the performance of the display panel.

[0053] In order to solve the above technical problems, this application is proposed. In order to better understand this application, Figures 2 to 6 The display panel, the method for manufacturing the display panel and the display device according to the embodiments of the present application are described in detail.

[0054] like Figures 2 to 4 As shown, the display panel provided by the embodiment of the first aspect of the present application includes: a substrate 1, a light-emitting functional layer 3 and an optical film layer 5; the light-emitting functional layer 3 is located on one side of the substrate 1 and includes a plurality of light-emitting units 31; the optical film layer 5 is located on the light-emitting side of the light-emitting functional layer 3, the optical film layer 5 includes a first film layer 51, the first film layer 51 is enclosed to form a first opening 50, the orthographic projection of the first opening 50 on the substrate 1 and the orthographic projection of the light-emitting unit 31 on the substrate 1 at least partially overlap; wherein, the first film layer 51 includes a first sublayer 511 and a second sublayer 512, the second sublayer 512 includes a main body 512a and an extension 512b that are interconnected, the main body 512a is located on the side of the first sublayer 511 away from the light-emitting functional layer 3, and the extension 512b covers at least part of the side wall of the first sublayer 511 facing the first opening 50.

[0055] Optionally, there are multiple ways to set the substrate 1. For example, the substrate 1 may include a substrate and a driving circuit arranged on the substrate. Optionally, the substrate 1 includes a first insulating layer, a second insulating layer and a third insulating layer arranged in a stacked manner. Exemplarily, the driving circuit may include a transistor, a storage capacitor and a driving signal line for connecting various devices. The transistor includes a semiconductor, a gate and a source and a drain. The storage capacitor includes a first plate and a second plate. As an example, the gate and the first plate may be located on the side of the first insulating layer facing the substrate, the second plate may be located between the first insulating layer and the second insulating layer, and the source and drain may be located between the second insulating layer and the third insulating layer.

[0056] Reference Figure 3, Optionally, a pixel definition layer 2 is provided on one side of the substrate 1, and the pixel definition layer 2 encloses a plurality of pixel openings, and each light-emitting unit 31 is at least partially located in each pixel opening. Optional. An encapsulation layer 4 is also provided between the light-emitting functional layer 3 and the optical film layer 5, and the encapsulation layer 4 can prevent water, oxygen and other media from invading the light-emitting device to protect the light-emitting device. The light-emitting device may include an anode, a light-emitting unit 31 and a cathode, so as to transmit an electrical signal through the anode and the cathode to drive the light-emitting unit 31 to emit light. Among them, the encapsulation layer 4 may include a thin film encapsulation (Thin-Film Encapsulation, TFE) layer. Specifically, the encapsulation layer 4 has a multilayer structure, which generally includes at least two inorganic film layers and at least one organic film layer, which are stacked in sequence along the direction from the light-emitting functional layer 3 to the optical film layer 5, and there are inorganic film layers on both sides of the organic film layer. For example, in some embodiments, the encapsulation layer 4 includes a first inorganic layer, an organic layer and a second inorganic layer stacked in sequence along the direction from the light-emitting functional layer 3 to the optical film layer 5.

[0057] Optionally, the light-emitting unit 31 may include one or more of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer, an emitting layer (EML), a hole blocking layer, an electron injection layer (EIL) and an electron transport layer (ETL).

[0058] Optionally, the light-emitting side of the light-emitting functional layer 3 may be the side of the light-emitting functional layer 3 facing the substrate 1, or the side of the light-emitting functional layer 3 facing away from the substrate 1. In the embodiment of the present application, the light-emitting side of the light-emitting functional layer 3 is taken as the side of the light-emitting functional layer 3 facing away from the substrate 1.

[0059] The extension portion 512b covers at least part of the side wall of the first sublayer 511 facing the first opening 50 . It can be understood that the extension portion 512b extends from the main body 512a toward the light-emitting functional layer 3 and partially or completely covers the side wall of the first sublayer 511 facing the first opening 50 .

[0060] The optical film layer 5 can be used to change the exit angle of the light from the light-emitting functional layer 3, so that the exit light emitted laterally can change the exit angle to be close to the normal viewing angle, thereby improving the light extraction efficiency of the display panel. Optionally, the first film layer 51 can be used as a low refractive index film layer in the optical film layer 5, and the first opening 50 can be filled with a high refractive index film layer. The exit light of the light-emitting functional layer 3 can be directly emitted from the first opening 50, and some large-angle light will be emitted toward at least part of the side wall of the first opening 50, that is, the first film layer 51. When the exit light from the light-emitting functional layer 3 deviates from the normal viewing angle and enters the first film layer 51 through the high refractive film layer, the first film layer 51 can fully reflect the exit light, so that the reflected exit light can be emitted in a direction close to the normal viewing angle, thereby improving the light extraction efficiency of the display panel.

[0061] In a display panel provided in an embodiment of the present application, the first film layer 51 includes a two-layer structure, and the extension portion 512b covers at least a portion of the side wall of the first sub-layer 511 facing the first opening 50. Even if there is a chamfered structure on the side of the first sub-layer 511 facing the first opening 50, the chamfer of the first sub-layer 511 is covered by the second sub-layer 512 to reduce the refraction of the chamfer of the first sub-layer 511 on the outgoing light, and reduce the loss of the outgoing light caused by the chamfer. This can improve the reflection effect of the first film layer 51 on the large-angle outgoing light, and emit more light to the normal viewing angle, thereby improving the light output efficiency and performance of the display panel.

[0062] Optionally, the extension portion 512b covering at least a portion of the sidewall of the first sub-layer 511 facing the first opening 50 can be formed by a baking process when preparing the first film layer 51. First, the morphology of the first film layer 51 is passed through a two-layer or multi-layer photoresist (OC) structure, and the upper colloidal protrusion is formed by utilizing the exposure or development difference, and the phenomenon that the photoresist collapses after baking is utilized to realize the morphology of the first film layer 51, reduce the size of the small chamfer at the bottom, so that more light can be reflected to the positive viewing angle, thereby achieving the goal of improving the light extraction efficiency.

[0063] Combined with reference Figure 3 and Figure 4 Optionally, the first sublayer 511 includes a bottom surface 500 facing the light-emitting functional layer 3, the extension portion 512b includes a first side surface 501 facing the first opening 50, and the angle between the first side surface 501 and the bottom surface 500 is θ1, θ1 is an acute angle and is greater than or equal to 45°. Optionally, the chamfer of the first sublayer 511 is less than 45°.

[0064] When θ1 is an acute angle, the large-angle light from the light-emitting unit 31 can change its propagation direction by reflection when it is emitted to the first side surface 501 and reflect toward the direction of the normal viewing angle, thereby improving the light extraction efficiency. When θ1 is greater than or equal to 45°, the refraction of light by the sharp chamfer can be effectively reduced.

[0065] In these optional embodiments, an extension portion 512b is provided to cover the chamfered position of the first sub-layer 511 so that the angle θ1 between the side wall of the first film layer 51 as a whole and the bottom surface 500 facing the first opening 50 is greater than or equal to 45°. This can effectively reduce the refraction of the outgoing light by the chamfer of the first sub-layer 511, reduce the loss of the outgoing light caused by the chamfer, improve the reflection effect of the first film layer 51 on the large-angle outgoing light, and emit more light to the positive viewing angle, thereby improving the light output efficiency and performance of the display panel.

[0066] Optionally, the cross section of the extension portion 512b gradually increases in the direction away from the light-emitting functional layer 3. The extension portion 512b can be formed by the second sub-layer 512 collapsing downward after being baked when the protrusion relative to the first sub-layer 511 is prepared. The farther from the collapse starting point, the smaller the size of the collapsed position. That is, in the direction close to the light-emitting functional layer 3, the cross-sectional area of ​​the extension portion 512b gradually decreases.

[0067] In these embodiments, as the extension portion 512b gradually moves away from the main body portion 512a, the size of the extension portion 512b gradually decreases, which is beneficial to the connection stability between the extension portion 512b and the main body portion 512a, and is beneficial to changing the inclination angle of the first film layer 51 relative to the bottom surface 500 through the extension portion 512b, thereby reducing the refraction of the outgoing light caused by the chamfer of the first sub-layer 511.

[0068] Optionally, the first sublayer 511 further includes a second side surface 502 facing the first opening 50, and the extension portion 512b further includes a third side surface 503 facing the second side surface 502, and the third side surface 503 is arranged in affixed relation with the second side surface 502. The connection between the two is tight, and no additional film layer is required between the third side surface 503 and the second side surface 502, thereby simplifying the preparation process. Optionally, the first sublayer 511 is arranged in affixed relation with the side surface facing the main body portion 512a.

[0069] Optionally, the angle between the second side surface 502 and the bottom surface 500 is θ2, and θ1>θ2. The inclination angle between the second side surface 502 and the bottom surface 500 is smaller than the inclination angle between the first side surface 501 and the bottom surface 500, that is, by providing the extension portion 512b to cover the second side surface 502, the overly sharp chamfer of the first sub-layer 511, which causes the refraction effect of the first film layer 51 on the light, can be effectively improved, and the reflection effect of the first film layer 51 on the large-angle exit light can be improved, so that more light can be emitted to the normal viewing angle, thereby improving the light extraction efficiency and performance of the display panel.

[0070] Optionally, 50°≤θ1≤88°. The angle between the first side surface 501 and the bottom surface 500 is between 63° and 88°, which is beneficial to optimize the light output. Exemplarily, θ1 can be 50°, 53°, 58°, 60°, 65°, 68°, 70°, 72°, 75°, 80°, 85° or 88°.

[0071] Optionally, 60°≤θ1≤88°. The angle between the first side surface 501 and the bottom surface 500 is between 60° and 88°, which can further help optimize the light output. The first side surface 501 and the bottom surface 500 may have different inclination angles at different positions, and the values ​​of these inclination angles are all between 60° and 88°, and the average value may be around 60-70°.

[0072] Combined with reference Figure 3 and Figure 4 In some optional embodiments, the orthographic projection of the first sublayer 511 on the substrate 1 is located within the orthographic projection of the second sublayer 512 on the substrate 1 .

[0073] The first sublayer 511 and the second sublayer 512 together enclose a plurality of first openings 50, and by arranging the orthographic projection of the first sublayer 511 on the substrate 1 to be located within the orthographic projection of the second sublayer 512 on the substrate 1, the extension portion 512b of the second sublayer 512 can more comprehensively cover the second side surface 502 of the first sublayer 511 facing the first opening 50, thereby increasing the overall inclination angle of the first film layer 51 relative to the bottom surface 500, reducing the influence of the chamfer on light refraction, and improving the light output efficiency of the display panel.

[0074] Reference Figure 4 In some optional embodiments, along the direction perpendicular to the substrate 1, the average thickness of the first sublayer 511 is H1, and the average thickness of the second sublayer 512 is H2, wherein 0.5 micrometers ≤ H1 ≤ 1.5 micrometers, and 1.0 micrometers ≤ H2 ≤ 2.0 micrometers. Optionally, the thickness of the second sublayer 512 may be the same as the thickness of the first sublayer 511, or may be greater than the thickness of the first sublayer 511, so that the extension 512b can better cover the second side 502 of the first sublayer 511. Exemplarily, the average thickness H1 of the first sublayer 511 may be 0.5 micrometers, 1 micrometers, or 1.5 micrometers. The average thickness H2 of the second sublayer 512 may be 1 micrometer, 1.5 micrometers, or 2 micrometers. H1 and H2 may be arbitrarily combined in the above definition.

[0075] Optionally, the material of the first sub-layer 511 can be the same as that of the second sub-layer 512. The first sub-layer 511 and the second sub-layer 512 can be prepared using the same photoresist, and then by dividing the first sub-layer 511 and the second sub-layer 512 into different exposure ranges, after two exposures, the second sub-layer 512 is formed into a morphology protruding from the first sub-layer 511 toward the first opening 50, and then the protrusion 210 is collapsed toward the side wall of the first sub-layer 511 through a baking process, so as to form a structure in which the extension portion 512b covers at least part of the side wall of the first sub-layer 511 facing the first opening 50.

[0076] Optionally, the photosensitivity of the first sublayer 511 is higher than that of the second sublayer 512. The first sublayer 511 and the second sublayer 512 can also be prepared using different types of photoresists, the difference being that the photosensitivity of the first sublayer 511 is higher than that of the second sublayer 512. Under the same exposure and development process conditions, the area etched by the first sublayer 511 is larger than the area etched by the second sublayer 512, so that only one exposure process is required to realize the morphology of the second sublayer 512 protruding from the first sublayer 511 toward the first opening 50, which is relatively cheaper. Then, the protrusion 210 is collapsed toward the side wall of the first sublayer 511 through a baking process, thereby forming a structure in which the extension 512b covers at least part of the side wall of the first sublayer 511 toward the first opening 50.

[0077] Optionally, the development speed of the second sub-layer 512 is lower than that of the first sub-layer 511. The first sub-layer 511 and the second sub-layer 512 can also be prepared using different types of photoresists, the difference being that the development speed of the second sub-layer 512 is lower than that of the first sub-layer 511. Under the same exposure and development process conditions, the etched area of ​​the first sub-layer 511 is larger than the etched area of ​​the second sub-layer 512, so that only one exposure process is required to realize the morphology of the second sub-layer 512 protruding from the first sub-layer 511 toward the first opening 50, which is relatively cheaper. Then, the protrusion 210 is collapsed toward the side wall of the first sub-layer 511 through a baking process, thereby forming a structure in which the extension portion 512b covers at least part of the side wall of the first sub-layer 511 toward the first opening 50.

[0078] Optionally, the photosensitivity of the first sublayer 511 is higher than that of the second sublayer 512, and the development speed of the second sublayer 512 is lower than that of the first sublayer 511. It is easier and more feasible to form the second sublayer 512 protruding from the first sublayer 511 toward the first opening 50.

[0079] Reference Figure 3In some optional embodiments, the optical film layer 5 further includes a second film layer 52, which is disposed on a side of the first film layer 51 away from the light-emitting functional layer 3 and fills the first opening 50, the refractive index of the first film layer 51 is N1, and the refractive index of the second film layer 52 is N2, wherein N1<N2.

[0080] In these embodiments, the light (outgoing light) emitted by the light-emitting unit 31 is emitted through the first opening 50, and the second film layer 52 is arranged on the side of the first film layer 51 away from the light-emitting functional layer 3 and fills the first opening 50. The refractive index N1 of the first film layer 51 is less than the refractive index N2 of the second film layer 52, so that the first film layer 51 and the second film layer 52 can constitute a microlens array (MLA) to form a total reflection interface. Through the combination of the low-refractive-index first film layer 51 and the high-refractive-index second film layer 52 of this specific structure, the direction of the outgoing light can be controlled, and the side-emitting large-angle outgoing light can be modulated into the front-angle emission, thereby improving the light output efficiency and the performance of the display panel.

[0081] In some optional embodiments, the difference between the refractive index of the second film layer 52 and the refractive index of the first film layer 51 satisfies: 0.25≤N2-N1≤0.35. The higher the refractive index of the high-refractive second film layer 52, the greater the difference in refractive index between the interfaces, and the better the total reflection effect. However, at the same time, the Fresnel reflection between the high-refractive second film layer 52 and other interfaces will also be greatly improved, which will limit the further improvement of the light output benefit and even lead to a decrease in light output efficiency. Therefore, in the embodiment of the present application, the difference in refractive index between the high-refractive film layer and the low-refractive film layer can be controlled between 0.18 and 0.35, which can have a better improvement in light output efficiency. Optionally, the refractive index of the first film layer 51 satisfies: 1.37≤N1≤1.5. For example, N1 can be 1.37, 1.4, 1.42, 1.45 or 1.5, etc. Optionally, the refractive index of the second film layer 52 satisfies: 1.55≤N2≤1.85. For example, N2 may be 1.55, 1.58, 1.65, 1.7 or 1.85.

[0082] Figure 5 A schematic structural diagram of a first sub-initial layer and a second sub-initial layer in a process of preparing a display panel provided by an embodiment of the present application is shown. Figure 6 A schematic diagram of a manufacturing process of a display panel provided in an embodiment of the present application is shown.

[0083] Combined with reference Figures 2 to 6 The embodiment of the second aspect of the present application further provides a method for preparing a display panel, which can be used to prepare the display panel in the embodiment of the first aspect above, and the preparation method includes:

[0084] S10, forming a first sub-initial layer and a second sub-initial layer located on one side of the first sub-initial layer, wherein the first sub-initial layer and the second sub-initial layer enclose a first opening, the first sub-initial layer faces the first opening and has a corner at one end away from the second sub-initial layer, and the second sub-initial layer has a protrusion relative to the first sub-initial layer in a direction perpendicular to its thickness.

[0085] S20, baking the second initial sub-layer to make the protruding portion collapse and cover the corner portion.

[0086] The first sub-initial layer 100 can be understood as the first sub-layer 511 that has not undergone the baking process, and the second sub-initial layer 200 can be understood as the second sub-layer 512 that has not undergone the baking process; the second sub-initial layer 200 has a protrusion 210 relative to the first sub-initial layer 100 in a direction perpendicular to its own thickness, that is, the second sub-initial layer 200 protrudes toward the first opening 50 relative to the first sub-initial layer 100 and is formed with the protrusion 210.

[0087] The baking temperature can be set according to the material properties of the second initial sub-layer to achieve the purpose of collapsing the suspended protrusions. Exemplarily, the baking temperature can be set between 50° C. and 100° C. For example, it can be 50° C., 65° C., 75° C., 90° C. or 100° C.

[0088] Optionally, the material of the second sub-initial layer 200 is photoresist (OC), or other light-transmitting materials with a certain refractive index that can collapse by baking. Then, the second sub-initial layer 200 is baked by utilizing the phenomenon that the photoresist collapses after baking, so that the protrusion 210 collapses and covers the corner 110. The corner 110 may also collapse after baking to form a sharper chamfer, and the extension 512b formed by the collapse of the protrusion 210 can effectively cover it, thereby realizing the morphology of the first film layer 51, reducing the refraction effect of the corner 110 on the light, so that more light can be reflected to the positive viewing angle, and the goal of improving the light extraction efficiency is achieved. Optionally, by controlling the exposure and development process of the two layers of photoresist, a structure in which the upper low-refractive photoresist protrusion is suspended in the air can be formed; then, a very thin fluid layer exists on the surface of the photoresist after development, which slowly descends to fill a part of the pit below; after baking, the upper low-refractive photoresist will collapse and further fill the pit, thereby finally reducing the refraction effect of the small chamfer of the MLA on the outgoing light, which is beneficial to the improvement of the light output yield at the positive viewing angle.

[0089] In a method for preparing a display panel provided in an embodiment of the present application, a protrusion 210 for forming an extension portion 512b covers a corner 110 of a first sub-initial layer 100, so that the second sub-initial layer 200 for subsequently forming a second sub-layer 512 covers at least a portion of the side wall of the first sub-initial layer 100 for forming a first sub-layer 511 toward the first opening 50, thereby forming a morphology in which the second sub-layer 512 covers the corner 110 of the first sub-layer 511, so as to reduce the refraction of the outgoing light by the corner 110 of the first sub-layer 511, reduce the outgoing light loss caused by the corner 110, and improve the reflection effect of the first film layer 51 on the large-angle outgoing light, emit more light to the normal viewing angle, and thereby improve the light output efficiency and performance of the display panel.

[0090] In some optional embodiments, before step S10, the preparation method includes:

[0091] Covering the entire surface of one side of the substrate with a first initial layer and a second initial layer in sequence;

[0092] The first initial layer and the second initial layer are patterned so that the first initial layer forms a first sub-initial layer and the second initial layer forms a second sub-initial layer.

[0093] In these embodiments, the first initial layer and the second initial layer are covered on the entire surface to facilitate the preparation of the first initial layer and the second initial layer, and then the desired morphology of the first sub-initial layer 100 and the second sub-initial layer 200 can be obtained more accurately through the patterning process. The patterning process includes exposure and development processes. That is, specific positions of the first initial layer or the second initial layer can be removed respectively to form the desired patterned first sub-initial layer 100 or second sub-initial layer 200.

[0094] Optionally, the step of patterning the first initial layer and the second initial layer includes:

[0095] Performing exposure and development processes on the first initial layer and the second initial layer to form a first opening;

[0096] The developing speed of the second initial layer is lower than that of the first initial layer, and / or the photosensitivity of the first initial layer is higher than that of the second initial layer.

[0097] In these embodiments, the first initial layer and the second initial layer can be prepared using different types of photoresists, for example, the development speed of the second initial layer is lower than that of the first initial layer, for example, the photosensitivity of the first initial layer is higher than that of the second initial layer, under the same exposure and development process conditions, the etched area of ​​the first initial layer is larger than the etched area of ​​the second initial layer, and only one exposure process is required to realize the morphology of the second sub-initial layer 200 protruding from the first sub-initial layer 100 toward the first opening 50, which is relatively low in cost. Then, the protruding portion 210 is collapsed toward the side wall of the first sub-initial layer 100 through a baking process, so as to form a morphology in which the extension portion 512b covers at least part of the side wall of the first sub-initial layer 100 facing the first opening 50.

[0098] In some optional embodiments, the material of the second initial layer is the same as that of the first initial layer, and the step of patterning the first initial layer and the second initial layer comprises:

[0099] performing an exposure and development process on the first region of the first initial layer;

[0100] performing an exposure and development process on the second region of the second initial layer;

[0101] The orthographic projection of the second area on the substrate is located within the orthographic projection of the first area on the substrate.

[0102] In these embodiments, the first initial layer and the second initial layer can be prepared using the same photoresist, and then the first initial layer and the second initial layer are divided into different exposure ranges so that the orthographic projection of the second area 220 on the substrate 1 is located within the orthographic projection of the first area 120 on the substrate 1. In this way, after two exposure and development processes, the second sub-initial layer 200 will form a morphology protruding from the first sub-initial layer 100 toward the first opening 50, and then the protrusion 210 is collapsed toward the side wall of the first sub-initial layer 100 through a baking process, thereby forming a structure in which the extension portion 512b covers at least part of the side wall of the first sub-initial layer 100 facing the first opening 50.

[0103] Optionally, in a plane perpendicular to the thickness direction of the display panel, the average width of the second region 220 is D2, and the average width of the first region 120 is D1, wherein 0.5 micrometers ≤ D1-D2 ≤ 3 micrometers. The difference of D1-D2 is greater than or equal to 0.5 micrometers, so that the protrusion 210 formed by the exposure and development process has a certain length, and can effectively cover at least part of the side wall of the second initial sub-layer 200 facing the first opening 50 after baking. The difference of D1-D2 is less than or equal to 3 micrometers, which can reduce the adverse effect of the extension 512b formed by the protrusion 210 after baking. Optionally, 0.5 micrometers ≤ D1-D2 ≤ 1.5 micrometers.

[0104] The embodiment of the third aspect of the present application further provides a display device, including the display panel provided by any of the embodiments of the first aspect. Since the display device provided by the embodiment of the third aspect of the present application includes the display panel of any of the embodiments of the first aspect, the display device provided by the embodiment of the third aspect of the present application has the beneficial effects of the display panel of any of the embodiments of the first aspect, which will not be described in detail here.

[0105] The display device in the embodiments of the present application includes but is not limited to mobile phones, personal digital assistants (PDAs), tablet computers, e-books, televisions, access control systems, smart landline phones, consoles, and other devices with display functions.

[0106] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A display panel, characterized in that: include: substrate; A light-emitting functional layer, located on one side of the substrate and comprising a plurality of light-emitting units; An optical film layer, located at a light-emitting side of the light-emitting functional layer, the optical film layer comprising a first film layer, the first film layer encloses a first opening, and an orthographic projection of the first opening on the substrate and an orthographic projection of the light-emitting unit on the substrate at least partially overlap; Among them, the first film layer includes a first sublayer and a second sublayer, the second sublayer includes a main part and an extension part connected to each other, the main part is located on the side of the first sublayer away from the light-emitting functional layer, and the extension part covers at least part of the side wall of the first sublayer facing the first opening.

2. The display panel according to claim 1, characterized in that: The first sublayer includes a bottom surface facing the light-emitting functional layer, the extension portion includes a first side surface facing the first opening, and the angle between the first side surface and the bottom surface is θ1, which is an acute angle and is greater than or equal to 45°; Preferably, along the direction away from the light-emitting functional layer, the cross section of the extension portion gradually increases; Preferably, the first sublayer further includes a second side surface facing the first opening, and the extension portion further includes a third side surface facing the second side surface, and the third side surface is disposed in contact with the second side surface; Preferably, the included angle between the second side surface and the bottom surface is θ2, and θ1>θ2; Preferably, 50°≤θ1≤88°; Preferably, 60°≤θ1≤88°.

3. The display panel according to claim 1, characterized in that: The orthographic projection of the first sub-layer on the substrate is located within the orthographic projection of the second sub-layer on the substrate; Preferably, along a direction perpendicular to the substrate, an average thickness of the first sublayer is H1, and an average thickness of the second sublayer is H2, wherein 0.5 micrometers ≤ H1 ≤ 1.5 micrometers, and 1.0 micrometers ≤ H2 ≤ 2.0 micrometers.

4. The display panel according to claim 1, characterized in that: The material of the first sub-layer is the same as the material of the second sub-layer; or, The photosensitivity of the first sublayer is higher than the photosensitivity of the second sublayer; or, The development speed of the second sub-layer is lower than the development speed of the first sub-layer.

5. The display panel according to claim 1, characterized in that: The optical film layer further includes a second film layer, which is disposed on a side of the first film layer away from the light-emitting functional layer and fills the first opening, the refractive index of the first film layer is N1, and the refractive index of the second film layer is N2, wherein N1<N2; Preferably, the difference between the refractive index of the second film layer and the refractive index of the first film layer satisfies: 0.18≤N2-N1≤0.35; Preferably, the refractive index of the first film layer satisfies: 1.37≤N1≤1.5; and / or the refractive index of the second film layer satisfies: 1.55≤N2≤1.

85.

6. A method for preparing a display panel, characterized in that: include: A first sub-initial layer and a second sub-initial layer located on one side of the first sub-initial layer are formed, wherein the first sub-initial layer and the second sub-initial layer enclose a first opening, the first sub-initial layer has a corner at one end facing the first opening and away from the second sub-initial layer, and the second sub-initial layer has a protrusion relative to the first sub-initial layer in a direction perpendicular to its thickness; The second initial sub-layer is baked so that the protrusions collapse to cover the corners.

7. The method for preparing a display panel according to claim 6, characterized in that: Before the step of forming the first sub-initial layer and the second sub-initial layer located on one side of the first sub-initial layer, the preparation method includes: Covering the entire surface of one side of the substrate with a first initial layer and a second initial layer in sequence; The first initial layer and the second initial layer are patterned so that the first initial layer forms a first sub-initial layer and the second initial layer forms the second sub-initial layer.

8. The method for preparing a display panel according to claim 7, characterized in that: The step of patterning the first initial layer and the second initial layer comprises: performing exposure and development processes on the first initial layer and the second initial layer to form a first opening; The developing speed of the second initial layer is lower than the developing speed of the first initial layer, and / or the photosensitivity of the first initial layer is higher than the photosensitivity of the second initial layer.

9. The method for preparing a display panel according to claim 7, characterized in that: The material of the second initial layer is the same as that of the first initial layer, and the step of patterning the first initial layer and the second initial layer comprises: performing an exposure and development process on the first region of the first initial layer; performing an exposure and development process on the second region of the second initial layer; Wherein, the orthographic projection of the second area on the substrate is located within the orthographic projection of the first area on the substrate; Preferably, in a plane perpendicular to the thickness direction of the display panel, the average width of the second region is D2, and the average width of the first region is D1, wherein 0.5 micrometers ≤ D1-D2 ≤ 3 micrometers; Preferably, 0.5 micron ≤ D1-D2 ≤ 1.5 micron.

10. A display device, characterized in that: The invention comprises the display panel as claimed in any one of claims 1 to 5.

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