Display panel, preparation method thereof and display device

Abstract

The application discloses a display panel, a preparation method thereof and a display device. The display panel comprises a substrate, a light-emitting element and a light-concentrating structure. The light-emitting element is arranged on one side of the substrate. The light-concentrating structure is arranged on at least one side of the light-emitting element away from the substrate. The thickness of the light-concentrating structure decreases in a direction from the center of the light-emitting element to the side edge. The above scheme effectively improves the light efficiency of the display panel and has high preparation efficiency.

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] Inorganic light-emitting diode (LED) displays mainly include Mini LED displays and Micro-LED displays. Mini LED and Micro-LED display panels used in high-end large-size displays are spliced ​​together from small modules that can be displayed independently.

[0003] However, the luminous efficacy of current LED display products needs to be improved. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a display panel and its preparation method, as well as a display device, which effectively improves light efficiency and has high preparation efficiency.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: to provide a display panel, including a substrate, a light-emitting element and a light-concentrating structure; the light-emitting element is disposed on one side of the substrate; the light-concentrating structure is disposed at least on the side of the light-emitting element away from the substrate, and the thickness of the light-concentrating structure decreases in a stepped manner along the direction from the center of the light-emitting element to the side edge.

[0006] Preferably, the display panel further includes microlenses, which are disposed at least on the side of the light-concentrating structure opposite to the substrate.

[0007] Preferably, the orthogonal projection of the microlens onto the substrate covers the orthogonal projection of the light-concentrating structure onto the substrate.

[0008] Preferably, the microlens encloses the light-emitting element and the light-concentrating structure.

[0009] Preferably, the material of the light-concentrating structure includes inorganic materials; and / or, the material of the microlens includes organic materials.

[0010] Preferably, the material of the light-concentrating structure includes silicon nitride or silicon oxide, and / or the material of the microlens includes optical adhesive.

[0011] Preferably, the orthogonal projection of the light-concentrating structure on the substrate covers the orthogonal projection of the light-emitting element on the substrate.

[0012] Preferably, the shape of the orthographic projection of the light-concentrating structure on the substrate is the same as the shape of the orthographic projection of the light-emitting element on the substrate.

[0013] Preferably, the maximum thickness of the light-concentrating structure is in the range of 1μm-2μm.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a display device, including the display panel in any embodiment.

[0015] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a method for manufacturing a display panel, including transferring a light-emitting element to one side of a substrate; forming a light-concentrating structure at least on the side of the light-emitting element away from the substrate, wherein the thickness of the light-concentrating structure decreases in a stepped manner along the direction from the center of the light-emitting element to the side edge.

[0016] Preferably, the step of forming a light-concentrating structure at least on the side of the light-emitting element away from the substrate includes: forming a first light-transmitting layer at least on the side of the light-emitting element away from the substrate; removing a portion of the first light-transmitting layer through the light-transmitting area of ​​a mask to form the light-concentrating structure, wherein, for each light-emitting element, the light transmittance of the light-transmitting area decreases in a stepwise manner along the direction from the center of the light-emitting element to the side edge.

[0017] Preferably, the mask is a grayscale mask or a halftone mask.

[0018] Preferably, after the step of forming a light-concentrating structure on at least the side of the light-emitting element away from the substrate, the method further includes forming a microlens on the side of the light-concentrating structure away from the substrate.

[0019] Preferably, the step of forming a microlens on the side of the light-concentrating structure opposite to the substrate includes: forming a second light-transmitting layer on the side of the light-concentrating structure opposite to the substrate; and curing the second light-transmitting layer to form the microlens.

[0020] The beneficial effects of this application are as follows: Unlike existing technologies, the display panel provided in this application has a light-concentrating structure on the light-emitting side of the light-emitting element. Since the light-concentrating structure is made of a light-transmitting material, the light emitted by the light-emitting element can pass through it. Furthermore, because the light-concentrating structure is thicker in the middle and thinner at the edges, it acts as a convex lens structure. This convex lens structure concentrates the light passing through the light-concentrating structure towards the center, focusing the light scattered to the sides onto the front, thereby greatly improving luminous efficiency and visibility. The stepped light-concentrating structure can be formed using a photomask, making fabrication convenient. The fabrication method provided in this application allows for batch formation of the light-concentrating structure after the transfer of the light-emitting element is completed, improving fabrication efficiency. Moreover, the light-concentrating structure is less prone to damage during fabrication, ensuring reliability. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the structure of one embodiment of the display panel of this application;

[0022] Figure 2 This is a schematic diagram of another embodiment of the display panel of this application;

[0023] Figure 3 This is a top view schematic diagram of one embodiment of the light-concentrating structure and light-emitting element of this application;

[0024] Figure 4 This is a schematic diagram of another embodiment of the display panel of this application;

[0025] Figure 5 This is a top view schematic diagram of another embodiment of the light-concentrating structure and light-emitting element of this application;

[0026] Figure 6 This is a flowchart illustrating one embodiment of the method for manufacturing the display panel according to this application;

[0027] Figures 7a-7c This is a schematic diagram of the structure of each step in the manufacturing method of the display panel of this application;

[0028] Figure 8 yes Figure 6 A flowchart of step S120. Detailed Implementation

[0029] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] See Figure 1 , Figure 1This is a schematic diagram of one embodiment of the display panel of this application. The display panel 10 includes a substrate 11, a light-emitting element 12, and a light-concentrating structure 13. Specifically, the substrate 11 includes a first pad 111 and a second pad 112 exposed on the surface of the substrate 11 and spaced apart. An insulating layer 113 is also provided on one side of the substrate 11. Through holes 113a are respectively provided on the insulating layer 113 corresponding to the first pad 111 and the second pad 112 to expose at least a portion of the first pad 111 and the second pad 112. The light-emitting element 12 is specifically a light-emitting diode, disposed on one side of the substrate 11. The light-emitting element 12 includes a first electrode 121 and a second electrode 122 facing the side of the substrate 11, which can be a P-type electrode and an N-type electrode, respectively. The light-emitting element 12 is electrically connected to the first pad 111 and the second pad 112 through the first electrode 121 and the second electrode 122, respectively. The light-concentrating structure 13 is disposed at least on the side of the light-emitting element 12 away from the substrate 11, that is, on the light-emitting side of the light-emitting element 12. The light-concentrating structure 13 is made of a light-transmitting material, and its thickness decreases in a stepped manner along the direction from the center of the light-emitting element 12 to the side edge. The light-concentrating structure 13 may include one or more steps.

[0031] The display panel 10 provided in this application has a light-concentrating structure 13 on the light-emitting side of the light-emitting element 12. Since the light-concentrating structure 13 is made of a light-transmitting material, the light emitted by the light-emitting element 12 can pass through the light-concentrating structure 13. Furthermore, because the light-concentrating structure 13 is thicker in the middle and thinner at the edges, the light-concentrating structure 13 is essentially a convex lens structure. This convex lens structure concentrates the light passing through the light-concentrating structure 13 towards the center, focusing the light scattered to the sides onto the front, thereby greatly improving light efficiency and visibility. The stepped light-concentrating structure 13 can be formed using a photomask, making fabrication convenient.

[0032] Optionally, see Figure 2 , Figure 2This is a schematic diagram of another embodiment of the display panel of this application. The display panel 10 also includes microlenses 14, which are at least disposed on the side of the light-concentrating structure 13 away from the substrate 11. Specifically, the material of the light-concentrating structure 13 includes inorganic materials, such as silicon nitride or silicon oxide. The material of the microlenses 14 includes organic materials, such as optical adhesives (OCA or OC, etc.). Since the microlenses 14 are usually formed by dispensing, and the material of the microlenses 14 has strong fluidity, in related technologies, the microlenses 14 are directly disposed on the light-emitting element 12, causing the material of the microlenses 14 to flow outward and making it difficult to concentrate in the center to form a hemispherical convex structure. As a result, the microlenses 14 are not ideal convex lens shapes, and the light efficiency improvement effect is poor. In this embodiment, a light-concentrating structure 13 with a central protrusion is provided on one side of the light-emitting element 12, and a microlens 14 is disposed on the light-concentrating structure 13, that is, the microlens 14 is formed after the light-concentrating structure 13, so that the microlens 14 is attached to the surface of the light-concentrating structure 13, and the shape of the microlens 14 is thick in the center and thin at the edges, which is closer to the ideal convex lens shape of a hemispherical shape, thus improving the light-concentrating effect. Moreover, since the material of the light-concentrating structure 13 is an inorganic material, its rigidity is better, which can better support the microlens 14, allowing the microlens 14 to maintain the ideal convex lens shape. In addition, since the light-concentrating structure 13 is a stepped structure, its upper surface has multiple planes, which allows the microlens 14 to stay more stably on the stepped structure, and the stepped surface friction is greater, which can reduce the material flow of the microlens 14, reduce the probability of deformation, and thus better ensure the shape of the microlens 14.

[0033] Optionally, the orthogonal projection of the light-concentrating structure 13 on the substrate 11 covers the orthogonal projection of the light-emitting element 12 on the substrate 11.

[0034] In some embodiments, see Figure 3 and combined Figure 1 , Figure 3 This is a top view schematic diagram of one embodiment of the light-concentrating structure and light-emitting element of this application. The orthographic projection of the light-concentrating structure 13 on the substrate (not shown) completely overlaps with the orthographic projection of the light-emitting element (covered, not shown) on the substrate. Since the light-concentrating structure 13 completely covers the light-emitting side of the light-emitting element 12, all the light emitted by the light-emitting element 12 can pass through the light-concentrating structure 13. After passing through the light-concentrating structure 13, the light is more concentrated, thereby improving the luminous efficiency.

[0035] In other embodiments, see Figure 4 , Figure 4This is a schematic diagram of one embodiment of the display panel of this application. The orthographic projection of the light-concentrating structure 13 on the substrate 11 is larger than and completely covers the orthographic projection of the light-emitting element 12 on the substrate 11. That is, part of the light-concentrating structure 13 (shown as a4 in the figure) is disposed on the side of the light-emitting element 12 (the area shown as a4 in the figure), and the distance from the upper surface of the light-concentrating structure 13 located outside the light-emitting element 12 to the surface of the substrate 11 is smaller than the distance from the upper surface of the light-concentrating structure 13 located above the light-emitting element 12 to the surface of the substrate 11. Since the light-concentrating structure 13 extends from above the light-emitting element 12 to the side of the light-emitting element 12, the light-concentrating structure 13 can support a larger microlens 14, thereby giving the microlens 14 better light efficiency. In other embodiments, the light-concentrating structure 13 located outside the light-emitting element 12 can also be provided in multiple layers, with the height gradually decreasing outward.

[0036] In other embodiments, the orthographic projection of the light-concentrating structure 13 onto the substrate 11 may also be within the orthographic projection of the light-emitting element 12 onto the substrate 11.

[0037] Optionally, continue reading Figure 2 The orthographic projection of the microlens 14 onto the substrate 11 overlaps the orthographic projection of the light-concentrating structure 13 onto the substrate 11. This arrangement allows the microlens 14 to be supported by the light-concentrating structure 13, and also allows the microlens 14 to have a larger size and better light efficiency.

[0038] Further reading Figure 4 The microlens 14 encloses the light-emitting element 12 and the light-concentrating structure 13, further increasing the size of the microlens 14. In other embodiments, the microlens 14 may also only cover part of the light-concentrating structure 13.

[0039] Optionally, the shape of the orthographic projection of the light-concentrating structure 13 onto the substrate 11 is the same as the shape of the orthographic projection of the light-emitting element 12 onto the substrate 11. For example... Figure 3 In the illustrated embodiment, the orthographic projection of the light-emitting element 12 onto the substrate 11 is rectangular, and the orthographic projections of each step of the light-concentrating structure 13 onto the substrate 11 are rectangles that gradually increase in size from the center to the edge. The overall orthographic projection shape of the light-concentrating structure 13 onto the substrate is also rectangular. These shapes make the shape of the light-concentrating structure 13 more closely match the shape of the light-emitting element 12, resulting in higher coverage. This structure gradually concentrates the light from the light-emitting element 12 towards the center, effectively focusing the light at the center of the light-emitting element 12, and ensuring a more uniform circumferential distribution of light, thus improving the display effect.

[0040] Alternatively, such as Figure 5 As shown, Figure 5This is a top view schematic diagram of another embodiment of the light-concentrating structure and light-emitting element of this application. The orthographic projection of each stage of the light-concentrating structure 13 onto the substrate (not shown) is a circle that gradually increases in size from the center to the edge. The above shape makes the edges of each step of the light-concentrating structure 13 smooth arcs, and the light-concentrating structure 13 and the microlens 14 covering it are closer to a hemisphere, that is, an ideal convex lens shape, thereby ensuring the light efficiency of the display panel 10.

[0041] In other embodiments, the orthographic projection of the light-concentrating structure 13 onto the substrate 11 may also be an ellipse, a regular polygon, or other shapes.

[0042] Specifically, the maximum thickness of the light-concentrating structure 13 ranges from 1 μm to 2 μm. Because the light-concentrating structure 13 is relatively thin, the step differences between each level are typically less than 1 μm. These smaller step differences result in a smoother surface for the light-concentrating structure 13, making it more hemispherical and ensuring effective light focusing. Furthermore, since the light-concentrating structure 13 is made of inorganic materials, its thinness and stepped structure make it less prone to stress concentration, thus preventing damage and other problems.

[0043] This application also provides a display device including the display panel 10 in any of the above embodiments. The display device equipped with the display panel 10 has better uniformity of light emission and better light emission performance. This display device can be a miniLED or micro-LED tablet computer, television, large-size display screen, etc.

[0044] See Figure 6 and combined Figures 7a-7c , Figure 6 This is a schematic flowchart of the method for manufacturing the display panel of this application. Figures 7a-7c This is a schematic diagram of the structural steps of the method for fabricating the display panel according to this application. The fabrication method includes:

[0045] Step S110: As Figure 7a As shown, the light-emitting element 12 is transferred to one side of the substrate 11. Specifically, before this step, the following steps are included: First, an insulating layer 113 is formed on one side of the substrate 11, and the insulating layer 113 has through holes 113a connecting the first pad 111 and the second pad 112. Then, solder 115 is formed in the through holes 113a, and a conductive adhesive layer 114 is formed above the insulating layer 113. Specifically, the material of the conductive adhesive layer 114 can be ACF (anisotropic conductive film). By pressing the light-emitting element 12 into the conductive adhesive layer 114, and bonding the first electrode 121 and the second electrode 122 of the light-emitting element 12 to the first pad 111 and the second pad 112 respectively, the transfer of the light-emitting element 12 is achieved. Optionally, all light-emitting elements 12 can be transferred to the substrate 11 by mass transfer.

[0046] Step S120: A light-concentrating structure 13 is formed on at least one side of the light-emitting element 12 away from the substrate 11, wherein the thickness of the light-concentrating structure 13 decreases in a stepped manner along the direction from the center of the light-emitting element 12 to the side edge.

[0047] The method of this application involves first transferring the light-emitting element 12, and then forming a light-concentrating structure 13 on the light-emitting element 12. Since the light-concentrating structure 13 is formed after the transfer of the light-emitting element 12 is completed, the light-concentrating structure 13 can be formed in batches, which can improve the preparation efficiency; and the light-concentrating structure 13 is not easily damaged during the preparation process, which can ensure reliability.

[0048] Optionally, see Figure 8 and combined Figures 7a-7c , Figure 8 yes Figure 6 A flowchart of step S120 is shown. Step S120 includes:

[0049] Step S121: As Figure 7b As shown, a first light-transmitting layer 130 is formed at least on the side of the light-emitting element 12 facing away from the substrate 11. Specifically, the first light-transmitting layer 130 can be formed by depositing an inorganic material, and the first light-transmitting layer 130 can be a whole film layer covering the light-emitting element 12 and the substrate 11.

[0050] Step S122: As Figure 7c As shown, a portion of the first light-transmitting layer 130 is removed through the light-transmitting area 2a of the mask 20 to form a light-concentrating structure 13. For each light-emitting element 12, the transmittance of the light-transmitting area 2a decreases in a stepwise manner along the direction from the center of the light-emitting element 12 to the side edge. Specifically, the mask 20 is a grayscale mask or a halftone mask. Taking a grayscale mask as an example, the light-transmitting area 2a of the grayscale mask includes multiple overlapping light-transmitting sub-areas (a first light-transmitting sub-area a0, a second light-transmitting sub-area a1, a third light-transmitting sub-area a2, and a fourth light-transmitting sub-area a3 arranged sequentially from the center to the edge). The transmittance of the light-transmitting sub-areas gradually decreases along the direction from the center to the edge. For example, the transmittance of the first light-transmitting sub-area located at the center is 100%, the transmittance of the second light-transmitting sub-area is 70%, the transmittance of the third light-transmitting sub-area is 30%, and the transmittance of the fourth light-transmitting sub-area is 30%, etc. Specifically, the method for forming the light-concentrating structure 13 is as follows: First, a mask 20 is placed above the display panel 10, such that the light-transmitting area 2a of the mask 20 corresponds to the light-emitting element 12. Then, the first light-transmitting layer 130 is exposed and developed through the mask 20 to pattern the first light-transmitting layer 130, thereby removing a portion of the first light-transmitting layer 130. The lower the light transmittance, the greater the thickness removed, thus forming a stepped light-concentrating structure 13 with the thickness decreasing from the center to the edge. The light-concentrating structure 13 can be formed in batches.

[0051] In other embodiments, the mask 20 can also be a halftone mask, whose light-transmitting area includes a fully light-transmitting area at the center, a fully light-blocking area at the outermost edge, and a semi-light-transmitting area between the fully light-transmitting and fully light-blocking areas. The three corresponding areas can remove the first light-transmitting layer 130 of different thicknesses, thus forming a stepped light-focusing structure 13 through the halftone mask, but the number of steps is limited.

[0052] Optionally, continue reading Figure 5 In some embodiments, after step S120, the following may also be included:

[0053] Step S130: Form a microlens 14 on the side of the light-concentrating structure 13 facing away from the substrate 11. This step specifically includes forming a second light-transmitting layer on the side of the light-concentrating structure 13 facing away from the substrate 11. Specifically, after forming the light-concentrating structure 13, a second light-transmitting layer is formed on the light-concentrating structure 13 by dispensing adhesive. The second light-transmitting layer can completely enclose the light-concentrating structure 13 and the light-emitting element 12. At this time, the second light-transmitting layer has fluidity, but due to the existence of surface tension and the support of the light-concentrating structure 13, the second light-transmitting layer is hemispherical. Then, the second light-transmitting layer is cured to form the microlens 14. Specifically, the second light-transmitting layer can be cured by irradiating with ultraviolet light or other methods to maintain its upwardly convex hemispherical shape. This shape is close to the ideal convex lens shape and has a strong ability to improve light efficiency.

[0054] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A display panel, characterized in that, The display panel includes: substrate; A light-emitting element is disposed on one side of the substrate; A light-concentrating structure is provided at least on the side of the light-emitting element away from the substrate, and the thickness of the light-concentrating structure decreases in a stepped manner along the direction from the center of the light-emitting element to the side edge.

2. The display panel according to claim 1, characterized in that, Also includes: Microlenses are disposed at least on the side of the light-concentrating structure opposite to the substrate; Preferably, the orthogonal projection of the microlens onto the substrate covers the orthogonal projection of the light-concentrating structure onto the substrate; Preferably, the microlens encloses the light-emitting element and the light-concentrating structure.

3. The display panel according to claim 2, characterized in that, The material of the light-concentrating structure includes inorganic materials; and / or, The microlens is made of organic materials; Preferably, the material of the light-concentrating structure includes silicon nitride or silicon oxide, and / or... The material of the microlens includes optical adhesive.

4. The display panel according to claim 1, characterized in that, The orthogonal projection of the light-concentrating structure onto the substrate covers the orthogonal projection of the light-emitting element onto the substrate; Preferably, the shape of the orthographic projection of the light-concentrating structure on the substrate is the same as the shape of the orthographic projection of the light-emitting element on the substrate.

5. The display panel according to claim 1, characterized in that, The maximum thickness of the light-concentrating structure ranges from 1 μm to 2 μm.

6. A display device, characterized in that, Includes the display panel as described in any one of claims 1-5.

7. A method for manufacturing a display panel, characterized in that, The method includes: The light-emitting element is transferred to one side of the substrate; A light-concentrating structure is formed at least on the side of the light-emitting element away from the substrate, wherein the thickness of the light-concentrating structure decreases in a stepped manner along the direction from the center of the light-emitting element to the side edge.

8. The preparation method according to claim 7, characterized in that, The step of forming a light-concentrating structure at least on the side of the light-emitting element opposite to the substrate includes: A first light-transmitting layer is formed at least on the side of the light-emitting element opposite to the substrate; The light-concentrating structure is formed by removing part of the first light-transmitting layer through the light-transmitting area of ​​the mask, wherein, for each light-emitting element, the light transmittance of the light-transmitting area decreases in a stepwise manner along the direction from the center of the light-emitting element to the side edge; Preferably, the mask is a grayscale mask or a halftone mask.

9. The preparation method according to claim 7, characterized in that, After the step of forming a light-concentrating structure at least on the side of the light-emitting element opposite to the substrate, the method further includes: A microlens is formed on the side of the light-concentrating structure opposite to the substrate.

10. The preparation method according to claim 9, characterized in that, The step of forming a microlens on the side of the light-concentrating structure opposite to the substrate includes: A second light-transmitting layer is formed on the side of the light-concentrating structure opposite to the substrate; The second light-transmitting layer is solidified to form the microlens.

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