Display panel, display device, and method for manufacturing a display panel

Abstract

Embodiments of the present invention provide a display panel, a display device, and a method for manufacturing a display panel. The display panel includes a substrate, a light-emitting unit, a first electrode, and a light collimation unit. The light-emitting unit is provided on one side of the substrate. The first electrode is provided on a side of the light-emitting unit away from the substrate. The light collimation unit is provided on a side of the first electrode away from the substrate, and the light collimation unit includes at least one micro-structure. In a direction away from the substrate, a cross-sectional area of the micro-structure gradually decreases. The manufacturing method is used to manufacture the display panel. The display panel according to the embodiments of the present invention has a high light emission rate and a high effect of emitting collimated light.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a display panel, a display device, and a method for manufacturing a display panel.

Background Art

[0002] A micro light-emitting diode (Micro LED) is a light-emitting device that uses an inorganic material (for example, gallium nitride) as a light-emitting material. A display device that employs a micro LED as a light-emitting device has advantages such as a fast response speed and high stability.

[0003] The light emitted by a micro light-emitting diode display panel has the characteristics of a point light source. During use, since some light cannot be utilized, problems such as a low light emission rate and a low collimated light effect occur.

Summary of the Invention

Means for Solving the Problems

[0004] The present invention provides a display panel, a display device, and a method for manufacturing a display panel.

[0005] According to a first aspect of an embodiment of the present invention, a substrate, a light-emitting unit provided on one side of the substrate, a first electrode provided on a side of the light-emitting unit away from the substrate, a light collimation unit provided on a side of the first electrode away from the substrate, a display panel comprising: the light collimation unit includes at least one fine structure, and in a direction away from the substrate, a cross-sectional area of the fine structure gradually decreases, a display panel is provided.

[0006] In the present invention, the refractive index of the material (i.e., the first electrode) located on the side facing the substrate of the optical collimation unit is different from the refractive index of the material located on the side away from the substrate of the optical collimation unit. By providing the microstructures with a gradually decreasing cross-sectional area, when the display panel emits light, the optical collimation unit can reduce the influence of the light emitted by the light-emitting unit due to reflection, which is advantageous for improving the brightness of the display panel. Furthermore, the optical collimation unit is also advantageous in reducing the refraction angle of the emitted light and facilitating the display panel to emit collimated light. The display panel of the present invention can achieve a better display effect in application scenarios such as display backlights, VR (Virtual Reality), AR (Augmented Reality) near-eye displays, and anti-peeping displays.

[0007] In one embodiment, a support unit is provided between the light-emitting units.

[0008] In one embodiment, the distance from the surface of the support unit away from the substrate to the substrate is greater than or equal to the distance from the surface of the optical collimation unit away from the substrate to the substrate.

[0009] In one embodiment, the material of the support unit includes a reflective material.

[0010] In one embodiment, the projection of the optical collimation unit onto the substrate covers at least the projection of the light-emitting unit onto the substrate.

[0011] In one embodiment, a plurality of adjacent first electrodes are connected to each other.

[0012] In one embodiment, the microstructure includes a nanostructure and / or a condenser lens.

[0013] In one embodiment, the nanostructure includes a bottom in contact with the first electrode, and the bottoms of adjacent nanostructures are connected to each other.

[0014] In one embodiment, the material of the first electrode is the same as the material of the nanostructure, and the first electrode is integrally connected to the nanostructure. In one embodiment, a support unit is provided between the light-emitting units. In the thickness direction of the substrate, the value range of the thickness of the nanostructure is 200 nm to 250 nm, and the surface of the support unit on the side away from the substrate is at least 250 nm higher than the surface of the first electrode on the side away from the substrate. In one embodiment, the light-collecting lens has a hemispherical structure, and the projection of the light-collecting lens onto the substrate covers at least the projection of the light-emitting unit onto the substrate. In one embodiment, a support unit is provided between the light-emitting units. In the thickness direction of the substrate, the value range of the thickness of the light-collecting lens is 2 μm to 3 μm, and the surface of the support unit on the side away from the substrate is at least 3 μm higher than the surface of the first electrode on the side away from the substrate.

[0015] In one embodiment, the material of the substrate is a silicon material. In one embodiment, the light-emitting unit includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence. The light-emitting layer includes a quantum well layer, and the first semiconductor layer is a second electrode. In one embodiment, the display panel further includes a sealing layer. The sealing layer is provided on the side away from the substrate of the light collimation unit and is filled between adjacent microstructures. The refractive index of the sealing layer is smaller than the refractive index of the microstructures.

[0016] In one embodiment, the substrate includes a driving circuit layer, and the driving circuit layer drives the light-emitting unit.

[0017] In one embodiment, the display panel includes bonding metal pads. The bonding metal pads are located between the substrate and the light-emitting unit, and the driving circuit layer drives the light-emitting unit through the bonding metal pads.

[0018] According to a second aspect of an embodiment of the present invention, a display device including the above display panel is provided.

[0019] According to a third aspect of an embodiment of the present invention, there is provided a method for manufacturing a display panel for manufacturing the above display panel, manufacturing an epitaxial structure layer including a second semiconductor layer, a light-emitting layer, and a first semiconductor layer sequentially laminated on one side of a support substrate; forming a bonding metal layer on a side of the epitaxial structure layer away from the support substrate; bonding the epitaxial structure layer to a substrate using the bonding metal layer; removing the support substrate and patterning the epitaxial structure layer to form a plurality of light-emitting units; manufacturing a first electrode on a side of the light-emitting unit away from the substrate; manufacturing an optical collimation unit on a side of the first electrode away from the substrate, including: The optical collimation unit includes at least one microstructure, and in a direction away from the substrate, a cross-sectional area of the microstructure gradually decreases, and a method for manufacturing a display panel is provided.

[0020] In one embodiment, when the microstructure includes a nanostructure, the step of manufacturing the nanostructure includes: first, forming a layer of metal layer on the first electrode and etching the metal layer to form the nanostructure; or, directly etching the first electrode to form the nanostructure.

[0021] In one embodiment, when the microstructure includes a nanostructure, the step of manufacturing the nanostructure includes: forming a photoresist pattern on a side of the first electrode away from the substrate, where the photoresist pattern includes a plurality of sub-patterns, and a cross-sectional area of the sub-patterns gradually decreases; etching the first electrode using the photoresist pattern as a mask, and transferring the topography of the photoresist pattern to the first electrode to form the nanostructure;

[0022] It should be noted that the above general description and the following detailed description are merely exemplary and explanatory, and do not limit the present invention.

[0023] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention and used to interpret the principles of the present invention together with the specification.

Brief Description of the Drawings

[0024]

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Mode for Carrying Out the Invention

[0025] Exemplary embodiments will be described in detail herein, and the examples are shown in the accompanying drawings. When the following description relates to the drawings, unless otherwise specified, the same numerals in different drawings indicate the same or similar elements. It should be noted that the embodiments described in the following exemplary embodiments do not represent all embodiments that are consistent with the present invention. On the contrary, they are merely examples of devices and methods that are consistent with some aspects of the present invention detailed in the appended claims.

[0026] The terms used in the present invention are only for explaining specific embodiments and do not limit the present invention. The singular forms "a kind", "the above-mentioned" and "said" used in the specification of the present invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0027] In addition, the "first", "second" and similar terms used in the description and claims of the present invention do not indicate any order, number or importance, but are used to distinguish different components. Similarly, similar terms such as "one" or "a" do not represent a limitation in number, but represent that there is at least one. Unless otherwise specified, similar terms such as "front part", "rear part", "lower part" and / or "upper part" are used only for the purpose of explanation and are not limited to one position or one spatial direction. For similar terms such as "including" or "having", it means that the elements or objects after "including" or "having" include the elements or objects listed before "including" or "having" and their equivalents, and do not exclude other elements or objects.

[0028] Hereinafter, with reference to the drawings, a display panel, a display device and a method for manufacturing a display panel according to embodiments of the present invention will be described in detail. When there is no contradiction, the features in the following embodiments and embodiments can be supplemented or combined with each other.

[0029] The present invention provides a display panel. As shown in FIG. 1, the display panel includes a substrate 10, a light-emitting unit 20, a first electrode 30 and a light collimation unit 31. The light-emitting unit 20 is provided on one side of the substrate 10. The first electrode 30 is provided on the side of the light-emitting unit 20 away from the substrate 10. The light collimation unit 31 is provided on the side of the first electrode 30 away from the substrate 10, and the light collimation unit 31 includes at least one microstructure 32. In the direction away from the substrate 10, the cross-sectional area of the microstructure 32 gradually decreases.

[0030] The light emitted by the light-emitting unit in the conventional display panel has the characteristics of a point light source. After the light emitted by the light-emitting unit is reflected or refracted, some light is not emitted from the display panel, resulting in a decrease in the light emission rate of the display panel. After the light emitted by the light-emitting unit is refracted, the light is deflected, so the collimated light emission effect of the display panel is poor, and finally the display effect of the display panel becomes poor.

[0031] In the present invention, the refractive index of the material (i.e., the first electrode) located on the side facing the substrate 10 of the optical collimation unit 31 is different from the refractive index of the material located on the side away from the substrate 10 of the optical collimation unit 31. By providing the micro-structure 32 with a gradually decreasing cross-sectional area, when the display panel emits light, the optical collimation unit 31 can reduce the influence on the light emitted by the light-emitting unit 20 due to reflection, which is advantageous for improving the luminance of the display panel. Further, the optical collimation unit 31 is also advantageous for reducing the refractive angle of the emitted light and making it easier for the display panel to emit collimated light. The display panel of the present invention can achieve a better display effect in application scenarios such as, for example, display backlights, VR (Virtual Reality), AR (Augmented Reality) near-eye displays, and anti-peeping displays.

[0032] In one embodiment, as shown in FIG. 1, the substrate 10 is a silicon substrate 10. The display panel on the silicon substrate 10 emits light from one side, has good light directivity, good light quality, and is suitable for application scenarios where a light emission angle is required. Also, by using a silicon substrate, the area of the drive circuit layer can be reduced, which is advantageous for improving the resolution of the display panel.

[0033] In one embodiment, the substrate 10 includes a drive circuit layer, and the drive circuit layer drives the light-emitting unit 20. The drive circuit layer includes a drive circuit, and may be, for example, a circuit including three transistors and one capacitor, or other types of drive circuits.

[0034] In one embodiment, the drive circuit layer may include a capacitor and a transistor, and the transistor may be a thin-film transistor (TFT) or a metal-oxide semiconductor transistor (MOS).

[0035] In one embodiment, the substrate 10 made of silicon may also be referred to as a driving backplane. The driving backplane according to the embodiments of the present invention may include a layer of Poly-Si layer and multiple layers of metal layers. The specific type of the driving backplane may be 1P6M, 1P5M or 1P8M. Here, taking the 1P6M type driving backplane as an example, it includes a layer of Poly-Si layer and six layers of metal layers. The Poly-Si layer is used to manufacture the active layer of the transistor, and the six layers of metal layers are used together to form a conductive pattern.

[0036] In one embodiment, the display panel includes a bonding metal pad 24. The bonding metal pad 24 is located between the substrate 10 and the light-emitting unit 20, and the driving circuit layer drives the light-emitting unit through the bonding metal pad 24. The material of the bonding metal pad 24 may be materials such as Cu-Sn alloy, Sn-Ag alloy, Sn-In alloy, Sn-Au alloy, Au-In alloy and Cu-In alloy.

[0037] In one embodiment, the light-emitting unit 20 includes a first semiconductor layer 21, a light-emitting layer 22, and a second semiconductor layer 23 stacked in sequence. The light-emitting layer 22 includes a quantum well layer. The first electrode 30 may be a cathode, the first semiconductor layer 21 may be a P-type semiconductor layer, and the second semiconductor layer 23 may be an N-type semiconductor layer. Here, the N-type semiconductor layer may include N-type gallium nitride (N-GaN), and the P-type semiconductor layer may include P-type gallium nitride (P-GaN). The first semiconductor layer 21 may be the second electrode of the light-emitting unit 20, and the second electrode may be an anode. The first semiconductor layer 21 is electrically connected to the driving circuit layer through the bonding metal pad 24.

[0038] In one embodiment, as shown in FIG. 2, the light-emitting layer 22 may be square, that is, the light-emitting unit 20 may be square, and the side length of the square may be 4 μm to 6 μm. For example, the side length of the light-emitting layer 22 may be 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, etc. In some other embodiments, the light-emitting layer 22 may be other shapes such as circular, and its specific size can be set according to the display requirements of the display panel, and is not particularly limited herein.

[0039] In one embodiment, the light-emitting unit 20 is used to form a Micro LED (Micro Light Emitting Diode). Here, the size range of the Micro LED is 0 μm to 100 μm. In some other embodiments, the light-emitting unit 20 may be used to form a Mini LED (Mini Light Emitting Diode), and here, the size range of the Mini LED is 100 μm to 300 μm.

[0040] In one embodiment, as shown in FIG. 1, the display panel includes an insulating layer 60 located on the second semiconductor layer 23. The insulating layer 60 is provided with an opening above the second semiconductor layer 23, and the first electrode 30 is connected to the second semiconductor layer 23 through the opening. In some embodiments, the insulating layer 60 may be connected to each other as an integrated insulating layer, and the insulating layer 60 is located above the second semiconductor layer 23 and between the light-emitting units 20.

[0041] In one embodiment, a plurality of adjacent first electrodes 30 are connected to each other. The light-emitting units 20 can be divided into a plurality of groups, and the first electrodes 30 of the light-emitting units 20 in each group can be connected to each other. It is also possible to connect the first electrodes 30 of all the light-emitting units 20 to each other to form an integrated electrode layer. The plurality of first electrodes 30 connected to each other are located not only above the light-emitting units 20 but also above the insulating layer 60 between the light-emitting units 20, and the plurality of first electrodes 30 connected to each other constitute a common electrode for the plurality of light-emitting units 20. By doing so, it is advantageous for reducing the size of the light-emitting units 20 and improving the resolution of the display panel. In some other embodiments, the first electrode 30 may be patterned.

[0042] In one embodiment, the projection of the optical collimation unit 31 onto the substrate 10 covers at least the projection of the light-emitting unit 20 onto the substrate 10. By doing so, it can be ensured that all the light emitted by the light-emitting unit 20 passes through the optical collimation unit 31 and then is emitted from the display panel, which is advantageous for reducing the refraction angle of the emitted light and making the display panel emit collimated light.

[0043] In one embodiment, the display panel further includes a sealing layer 50, the sealing layer 50 is provided on the side away from the substrate 10 of the optical collimation unit 31 and filled between adjacent microstructures, and the refractive index of the sealing layer 50 is smaller than the refractive index of the microstructure 32. By doing so, the sealing layer 50 can protect layers such as the light-emitting unit 20 and is advantageous for improving the stability of the display panel. The above installation is advantageous for reducing the influence on the light emitted by the light-emitting unit 20 due to refraction and reflection, and is advantageous for improving the brightness of the display panel. In some embodiments, the material of the sealing layer 50 may be a material such as organic silicone or epoxy resin.

[0044] In one embodiment, as shown in FIG. 1, a support unit 40 is provided between the light-emitting units 20. The support unit 40 is filled in the gap between the light-emitting units 20, which is advantageous for improving the stability of the display panel. When the display panel includes the encapsulation layer 50, the support unit 40 can support the encapsulation layer 50 and reduce the force applied to the layer below the encapsulation layer 50.

[0045] In one embodiment, the material of the support unit may be a reflective material. For example, the material of the support unit 40 may be a reflective white glue. When the emission colors of the light-emitting units 20 are the same, the material of the support unit 40 may be a white glue. Some of the light emitted by the light-emitting layer 22 is reflected by the surface of the support unit 40 during transmission, and the reflected light can be emitted outside the display panel. Therefore, it is advantageous to further improve the light emission rate of the display panel and the front light-emitting effect of the display panel. In some other embodiments, when the emission colors of the light-emitting units 20 are different, the support unit may be an adhesive of a dark color such as black or gray. When the material of the support unit 40 is an adhesive of a dark color such as black or gray, some of the light emitted by the light-emitting layer 22 is absorbed by the support unit 40, and the color crossover between different light-emitting units 20 can be avoided.

[0046] In one embodiment, the distance from the surface of the support unit away from the substrate to the substrate is greater than or equal to the distance from the surface of the optical collimation unit away from the substrate to the substrate. By doing so, when the encapsulation layer 50 is provided above the optical collimation unit 31, the encapsulation layer 50 directly covers the microstructure 32. The presence of the support unit 40 can support and protect the microstructure 32, support a part of the encapsulation layer 50, and avoid the microstructure 32 being deformed under force when subsequent layers such as the encapsulation layer 50 are manufactured in the display panel.

[0047] In one embodiment, the microstructure 32 includes a nanostructure 321 and / or a condenser lens 322.

[0048] Here, the design principle of the nanostructure 321 is specifically as follows.

[0049] Nanostructures with a smaller period may be called zero-order diffraction gratings. When a plane wave passes through the nanostructure, its wavefront does not change, which is the same as a plane wave passing through a dielectric film. The equivalent refractive index of the nanostructure is determined by the effective medium theory. As shown in FIG. 1, the optical collimation unit 31 in the present invention includes a plurality of nanostructures 321. In the present invention, a microstructure with a size smaller than 1000 nm can be regarded as a nanostructure. When light passes through the optical collimation unit 31, the specific contour of the nanostructure 321 cannot be recognized by the light, and only zero-order diffraction exists. In this case, the nanostructure 321 can be equivalent to a single layer of homogeneous medium. The nanostructure 321 can be regarded as a stack of multiple thin films in the layer stacking direction. In the layer stacking direction from the substrate 10 to the optical collimation unit 31, the cross-sectional area of the nanostructure 321 gradually decreases. Therefore, the cross-sectional areas of the multiple thin films regarded as constituting the nanostructure 321 also gradually decrease in the layer stacking direction from the substrate 10 to the optical collimation unit 31, as shown in FIGS. 1 and 3 (where n1 is larger than n2). According to the calculation formula of the equivalent refractive index,

[0050]

Equation

[0051] It becomes as follows. (Here, n effis the equivalent refractive index, f is the duty ratio of the thin film of each layer, n1 is the refractive index of the material located on the side facing the substrate 10 of the optical collimation unit 31, and n2 is the refractive index of the material on the side away from the substrate 10 of the nanostructure 321.)

[0052] In the stacking direction of the layers from the substrate 10 to the optical collimation unit 31 (i.e., in the z direction in FIG. 3), it can be seen that the equivalent refractive index of the optical collimation unit 31 gradually changes from n1 to n2. According to the Fresnel reflection theory, when light propagates from a medium with a refractive index of n1 (the medium with a refractive index of n1 in FIG. 3 is an optically dense medium) to another medium with a refractive index of n2 (the medium with a refractive index of n2 in FIG. 3 is an optically sparse medium), light reflection may occur at the boundary between the two media with different refractive indices. Moreover, the greater the difference in the refractive indices of the two media, the easier it is for light to be reflected at the interface between the two media. According to the refraction formula, when light is incident at the same angle from an optically dense medium with a refractive index of n1 to an optically sparse medium with a refractive index of n2, the greater the difference between the refractive index n1 and the refractive index n2, the larger the exit angle of the light. The nanostructure 321 in the present invention can realize a uniform transition of the refractive index between two different media, thereby reducing the reflection of the light emitted by the light-emitting unit 20 by the layer, which is advantageous for improving the luminance of the display panel. Also, it is advantageous for reducing the refraction angle of the emitted light and emitting collimated light to the display panel.)

[0053] In one embodiment, the nanostructure 321 includes a bottom in contact with the first electrode 30, and the bottoms of adjacent nanostructures 321 are connected to each other. The nanostructure 321 with the bottoms connected to each other can increase the contact area between the optical collimation unit 31 and the first electrode 30, which is advantageous for realizing a uniform transition of the refractive index from the side of the optical collimation unit 31 facing the substrate 10 to the side away from the substrate 10 of the optical collimation unit 31.)

[0054] In one embodiment, the nanostructure 321 includes a top portion that is away from the first electrode 30, and the top portion of the nanostructure 321 may be a dot-shaped or linear tip. Taking the case where the sum of the areas of the bottom portions of the nanostructure 321 facing the substrate 10 is the same as the area of the first electrode 30 as an example, according to the calculation formula of the equivalent refractive index, the value of the duty ratio f of the bottommost thin film in the plurality of thin films regarded as constituting the nanostructure 321 is 1, and the equivalent refractive index of the bottommost thin film is n1. When the top portion of the nanostructure 321 is a dot-shaped or linear tip, the value of the duty ratio f of the uppermost thin film in the plurality of thin films regarded as constituting the nanostructure 321 can be regarded as 0, and the equivalent refractive index of the uppermost thin film is n1. Taking the example of providing a sealing layer 50 on the side of the nanostructure 321 away from the substrate 10, due to the above installation, the equivalent refractive index of the boundary between the nanostructure 321 and the first electrode 30 is the same as the equivalent refractive index of the first electrode 30, and the equivalent refractive index of the boundary between the nanostructure 321 and the sealing layer 50 is the same as the equivalent refractive index of the sealing layer 50. In the direction from the first electrode 30 to the sealing layer 50, the nanostructure 321 can better realize a uniform change in the refractive index between layers, which is advantageous for improving the brightness of the display panel and emitting collimated light.

[0055] In one embodiment, the shape of the nanostructure 321 included in the fine structure 32 of the optical collimation unit 31 may be a pyramid shape. The duty ratio f of the bottom surface of the pyramid array formed by the plurality of nanostructures 321 is 1. The range of the value of the side length of the bottom surface of the nanostructure 321 is 270 nm to 330 nm. The lattice constant of the nanostructure 321 is 270 nm to 330 nm. The thickness of the nanostructure 321 is 200 nm to 250 nm. In the direction from the substrate 10 to the optical collimation unit 31, the cross-sectional area of the pyramid-shaped nanostructure 321 gradually decreases, and the equivalent refractive index of the nanostructure 321 gradually decreases. When the nanostructure 321 is provided in a pyramid shape, it is convenient for the manufacturing and processing of the optical collimation unit 31. In some other embodiments, the shape of the nanostructure 321 may be other shapes such as a hemispherical shape.

[0056] In this embodiment, the side of the nanostructure 321 facing the substrate 10 is the first electrode 30 (the first electrode 30 may be a cathode), and the refractive index of the first electrode 30 is 2.0. The side of the optical collimation unit 31 away from the substrate 10 is the sealing layer 50, and the refractive index of the sealing layer 50 is 1.5. As shown in FIG. 4, which is an equivalent refractive index fitting curve of the pyramid-shaped nanostructure 321. As can be seen from the figure, as the duty ratio of the nanostructure 321 decreases, the equivalent refractive index of the nanostructure 321 gradually changes from 2 to 1.5, changes linearly, and the equivalent refractive index changes uniformly. When light passes through the first electrode 30 and the sealing layer 50, the presence of the nanostructure 321 can weaken the reflection (especially total reflection) phenomenon of light, which is beneficial to improving the light emission rate and is also beneficial to the emission of collimated light.

[0057] In one embodiment, as shown in FIG. 5, the nanostructure 321 is formed by etching after providing a metal layer on the first electrode 30.

[0058] In one embodiment, as shown in FIG. 6, the material of the first electrode 30 is the same as that of the nanostructure 321, and the first electrode 30 is integrally connected to the nanostructure 321. That is, the nanostructure 321 can be formed by directly etching the first electrode 30. In this way, it is advantageous to simplify the manufacturing process of the nanostructure 321.

[0059] In one embodiment, as shown in FIG. 7, in the thickness direction of the substrate 10, the value range of the thickness of the nanostructure 321 is 200 nm to 250 nm, and the surface of the support unit 40 on the side away from the substrate 10 is at least 250 nm higher than the surface of the first electrode 30 on the side away from the substrate 10. The thickness of the nanostructure 321 may be, for example, 200 nm, 220 nm, 240 nm, 250 nm, etc. If the size of the nanostructure 321 is too small, the change in its equivalent refractive index will be fast. If the size of the nanostructure 321 is too large, the nanostructure 321 may cause other diffractions. When the size of the nanostructure 321 is within the above range, it is advantageous to improve the light emission rate of the display panel and emit collimated light from the display panel. The support unit 40 is at least 250 nm higher than the electrode. When the sealing layer 50 is provided above the nanostructure 321, the sealing layer 50 directly covers the nanostructure 321. The presence of the support unit 40 can support and protect the nanostructure 321, support a part of the sealing layer 50, and avoid the nanostructure 321 being deformed under force when subsequent layers such as the sealing layer 50 are manufactured in the display panel. In some other embodiments, the value range of the thickness of the nanostructure 321 may be changed according to the size of the light emitting unit 20.

[0060] In one embodiment, the support units 40 may be connected to each other to form an integrated support layer. The integrated support layer has better support performance for the optical collimation unit 31.

[0061] In one embodiment, as shown in FIG. 8, the display panel includes a condenser lens 322 located on the side of the first electrode 30 away from the substrate 10. After the light emitted from the light-emitting layer 22 is emitted through the first electrode 30, some of the light still has a large angle with respect to the direction perpendicular to the substrate 10, that is, some of the light still cannot be emitted vertically from the display panel. By providing the condenser lens 322, when some of the light is emitted through the condenser lens 322, the light is further deflected, reducing the angle between some of the light and the direction perpendicular to the substrate 10, which is advantageous for the display panel to emit collimated light.

[0062] In one embodiment, the condenser lens 322 has a hemispherical structure, and the projection of the condenser lens 322 onto the substrate 10 covers at least the projection of the light-emitting unit 20 onto the substrate 10. The hemispherical structure is advantageous for the light to be emitted from the display panel after being deflected. Also, the above installation is advantageous for allowing all the light emitted by the light-emitting unit 20 to enter the condenser lens 322, reducing the refractive angle of the emitted light, and thus advantageous for causing the display panel to emit collimated light.

[0063] In one embodiment, after providing the condenser lens 322 on the display panel, the encapsulation layer 50 is not provided. At this time, the condenser lens 322 can serve to emit collimated light and at the same time can also serve to encapsulate and protect the underlying layer instead of the encapsulation layer 50. In one embodiment, as shown in FIG. 8, a support unit 40 is provided between adjacent light-emitting units 20. The distance from the surface of the support unit 40 away from the substrate 10 to the substrate 10 is greater than or equal to the distance from the surface of the condenser lens 322 away from the substrate to the substrate 10. When other layers are provided above the condenser lens 322, for example, when a glass cover is provided above the condenser lens 322, the glass cover directly covers the condenser lens 322. With the above installation, the support unit 40 supports other layers such as the glass cover, avoiding deformation of the condenser lens 322 due to pressure.

[0064] Moreover, after a part of the light is emitted from the condenser lens 322, this part of the light can be made to be emitted from the display panel by reflection by the support unit 40, and the combination of the condenser lens 322 and the support unit 40 is also advantageous for improving the light emission effect of the display panel.

[0065] In one embodiment, in the thickness direction of the substrate 10, the range of the value of the thickness of the condenser lens 322 is 2 μm to 3 μm, and the surface of the support unit 40 on the side away from the substrate 10 is at least 3 μm higher than the surface of the first electrode 30 on the side away from the substrate 10. The radius of the condenser lens 322 may be, for example, 2 μm, 2.5 μm, 3 μm, etc. If the size of the condenser lens 322 is too small, part of the light cannot enter the condenser lens 322. If the size of the condenser lens 322 is too large, it will affect the installation of other layers. When the size of the condenser lens 322 is within the above range, the size of the condenser lens 322 matches the size of the light emitting unit 20, and most of the light can be deflected after entering the condenser lens 322 and passing through the condenser lens 322, which is advantageous for the display panel to emit collimated light.

[0066] In one embodiment, as shown in FIG. 1, the fine structure 32 of the optical collimation unit 31 simultaneously includes a nanostructure 321 and a condenser lens 322. When the display panel emits light, the above installation is advantageous for reducing the influence on the light emitted by the light emitting unit 20 by reflection (especially total reflection), thereby being advantageous for improving the brightness of the display panel, and also being advantageous by reducing the refraction angle of the emitted light, and being advantageous for making the display panel emit collimated light.

[0067] In one embodiment, as shown in FIGS. 7 and 8, the microstructure 32 of the optical collimation unit 31 may include only one of the nanostructure 321 and the condenser lens 322. Only the nanostructure 321 or the condenser lens 322 may be directly provided on the first electrode 30, and the light emission effect of the display panel can be improved by only the nanostructure 321 or the condenser lens 322.

[0068] Embodiments of the present invention further provide a display device including the display panel described in any of the above embodiments. The display device according to the embodiments of the present invention may be any device having a display function, such as an AR or VR device.

[0069] The display device according to the embodiments of the present invention may include a plurality of the display panels described in any of the above embodiments. The plurality of display panels may be joined together to form the display device.

[0070] Based on the same inventive concept, embodiments of the present invention further provide a manufacturing method of a display panel for manufacturing the above display panel. The manufacturing method includes the following steps.

[0071] In step 100, as shown in FIG. 9, an epitaxial structure layer including a second semiconductor layer 23, a light emitting layer 22, and a first semiconductor layer 21 stacked in sequence is manufactured on one side of a support substrate 70.

[0072] In step 200, as shown in FIG. 10, a bonding metal layer 25 is formed on the side of the epitaxial structure layer away from the support substrate 70, and the epitaxial structure layer is bonded to a substrate 10 using the bonding metal layer 25.

[0073] In step 300, as shown in FIGS. 11 and 12, the support substrate 70 is removed, and the epitaxial structure layer is patterned to form a plurality of light emitting units 20.

[0074] In step 400, as shown in FIG. 13, a first electrode 30 is manufactured on the side of the light-emitting unit 20 away from the substrate 10.

[0075] In step 500, as shown in FIG. 14, an optical collimation unit 31 is manufactured on the side of the first electrode 30 away from the substrate 10. The optical collimation unit 31 includes at least one micro-structure 32. In the direction away from the substrate 10, the cross-sectional area of the micro-structure 32 gradually decreases.

[0076] In step 100, the support substrate 70 is a silicon support substrate. By manufacturing an epitaxial structure layer using the silicon support substrate 70, the utilization rate of the epitaxial area can be improved, which is advantageous for improving the production efficiency and yield of the light-emitting unit 20. Also, in subsequent step 300, the silicon support substrate 70 can be directly removed by a hydrofluoric acid etching process. This removal method can avoid damaging the epitaxial structure layer during the process of removing the support substrate 70, and can reduce the difficulty of peeling the support substrate 70.

[0077] In this step 100, the epitaxial structure layer can be deposited on the support substrate 70 by a MOCVD (Metal-organic Chemical Vapor Deposition) process. Specifically, first, a second semiconductor layer 23 (N-type GaN layer) is manufactured on the support substrate 70, then a light-emitting layer 22 (multi-layer multiple quantum well layer) is manufactured, and thereafter, a first semiconductor layer 21 (P-type GaN layer) is manufactured.

[0078] In step 200, the material of the bonding metal layer 25 may be one of Cu-Sn alloy, Sn-Ag alloy, Sn-In alloy, Sn-Au alloy, Au-In alloy, and Cu-In alloy. The epitaxial structure layer may be bonded to the substrate 10 using the bonding metal layer 25 by eutectic bonding or thermocompression bonding, and the value range of the bonding temperature is 100°C to 400°C. Thereafter, the bonding metal layer 25 may be patterned to form a bonding metal pad 24.

[0079] In step 300, hydrofluoric acid is used to remove the silicon support substrate 70.

[0080] Before step 400, as shown in FIG. 15, the manufacturing method further includes manufacturing an insulating layer 60 above and between the light-emitting units 20, and providing an opening in the insulating layer 60 above the light-emitting unit 20.

[0081] In step 400, as shown in FIG. 13, the first electrode 30 is manufactured above the insulating layer 60, and the first electrode 30 may be a cathode, and the cathode is electrically connected to the light-emitting unit 20 through the above opening. In this step, a plurality of adjacent first electrodes 30 may be connected to each other.

[0082] Before step 500, as shown in FIG. 13, the manufacturing method further includes manufacturing a support unit 40 between the light-emitting units 20, and the material of the support unit 40 may be a white adhesive or a dark-colored adhesive such as black or gray.

[0083] In step 500, when the microstructure 32 includes a nanostructure 321, the step of manufacturing the nanostructure 321 includes first forming a layer of metal layer on the first electrode 30, etching the metal layer to form the nanostructure 321, or directly etching the first electrode 30 to form the nanostructure 321.

[0084] In step 500, as shown in FIG. 16, the step of manufacturing the nanostructure 321 is a step of forming a photoresist pattern 80 on the side of the first electrode 30 away from the substrate 10, wherein the photoresist pattern 80 includes a plurality of sub-patterns 81, and the cross-sectional area of the sub-patterns 81 gradually decreases; a step of dry-etching the first electrode 30 using the photoresist pattern 80 as a mask, and transferring the topography of the photoresist pattern 80 to the first electrode 30 to form the nanostructure 321.

[0085] The shape of the nanostructure 321 manufactured by the above process may be a pyramid shape. The duty ratio f of the bottom surface of the pyramid array formed by the plurality of nanostructures 321 is 1. The range of the value of the length of the side of the bottom surface of the nanostructure 321 is 270 nm to 330 nm. The lattice constant of the nanostructure 321 is 270 nm to 330 nm. The thickness of the nanostructure 321 is 200 nm to 250 nm.

[0086] In step 500, the manufacturing method may further include a step of manufacturing a sealing layer 50 or a condenser lens 322 on the first electrode 30; a step of applying a UV (Ultraviolet Rays) adhesive to the sealing layer 50 or the condenser lens 322 and bonding a glass cover with the UV adhesive.

[0087] The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention is disclosed as above in the preferred embodiments, it is not for limiting the present invention. Those skilled in the art can, without departing from the scope of the technical solution of the present invention, make some modifications or equivalent modifications to equivalent embodiments with equivalent changes by using the above-disclosed technical content. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the scope of the technical solution of the present invention.

[0088] The disclosure in this patent document includes materials protected by copyright. The copyright belongs to the copyright owner. The copyright owner does not oppose the reproduction by a third party of this patent document or this patent disclosure as it exists in the official records and files of the Patent and Trademark Office.

Explanation of Reference Numerals

[0089] 10 Substrate 20 Light-emitting unit 21 First semiconductor layer 22 Light-emitting layer 23 Second semiconductor layer 24 Bonding metal pad 30 First electrode 31 Optical collimation unit 32 Microstructure 321 Nanostructure 322 Condensing lens 40 Support unit 50 Encapsulation layer 60 Insulating layer

Claims

1. A substrate, a light-emitting unit provided on one side of the substrate, a first electrode provided on the side of the light-emitting unit away from the substrate, a light collimation unit provided on the side of the first electrode away from the substrate, comprising a display panel, wherein the light collimation unit includes at least one fine structure, and in the direction away from the substrate, the cross-sectional area of the fine structure gradually decreases, A display panel characterized by this.

2. A support unit is provided between the light-emitting units, The display panel according to claim 1, characterized by this.

3. The distance from the surface of the support unit on the side away from the substrate to the substrate is greater than or equal to the distance from the surface of the light collimation unit on the side away from the substrate to the substrate, The display panel according to claim 2, characterized by this.

4. The material of the support unit includes a reflective material, The display panel according to claim 2, characterized by this.

5. The projection of the light collimation unit onto the substrate covers the projection of the light-emitting unit onto the substrate, The display panel according to claim 1, characterized by this.

6. A plurality of adjacent first electrodes are connected to each other, The display panel according to claim 1, characterized by this.

7. The fine structure includes a nanostructure and / or a condenser lens, The display panel according to claim 1, characterized by this.

8. The nanostructure includes a bottom in contact with the first electrode, and the bottoms of adjacent nanostructures are connected to each other, The display panel according to claim 7, characterized by this.

9. The material of the first electrode is the same as the material of the nanostructure, and the first electrode is integrally connected to the nanostructure, The display panel according to claim 7, characterized by this.

10. A support unit is provided between the light-emitting units. In the thickness direction of the substrate, the value range of the thickness of the nanostructure is 200 nm to 250 nm, and the surface of the support unit on the side away from the substrate is at least 250 nm higher than the surface of the first electrode on the side away from the substrate, The display panel according to claim 7, characterized by this.

11. The condenser lens has a hemispherical structure, and the projection of the condenser lens onto the substrate covers the projection of the light-emitting unit onto the substrate, The display panel according to claim 7, characterized by this.

12. A support unit is provided between the light-emitting units, and in the thickness direction of the substrate, the range of the value of the thickness of the condenser lens is 2 μm to 3 μm, and the surface of the support unit on the side away from the substrate is at least 3 μm higher than the surface of the first electrode on the side away from the substrate. The display panel according to claim 7, characterized in that.

13. The material of the substrate is a silicon material. The display panel according to claim 1, characterized in that.

14. The light-emitting unit includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer laminated in order, the light-emitting layer includes a quantum well layer, and the first semiconductor layer is a second electrode. The display panel according to claim 1, characterized in that.

15. Further includes a sealing layer, the sealing layer is provided on the side of the light collimation unit away from the substrate, and is filled between adjacent microstructures, and the refractive index of the sealing layer is smaller than the refractive index of the microstructures. The display panel according to claim 1, characterized in that.

16. The substrate includes a drive circuit layer, and the drive circuit layer drives the light-emitting unit. The display panel according to claim 1, characterized in that.

17. The display panel includes a bonding metal pad, the bonding metal pad is located between the substrate and the light-emitting unit, and the drive circuit layer drives the light-emitting unit through the bonding metal pad. The display panel according to claim 16, characterized in that.

18. Including the display panel according to any one of claims 1 to 17. The display device, characterized in that.

19. A method for manufacturing a display panel for manufacturing the display panel according to any one of claims 1 to 17, Manufacturing an epitaxial structure layer including a second semiconductor layer, a light-emitting layer, and a first semiconductor layer laminated in order on one side of a support substrate; Forming a bonding metal layer on the side of the epitaxial structure layer away from the support substrate; Bonding the epitaxial structure layer to a substrate using the bonding metal layer; Removing the support substrate and patterning the epitaxial structure layer to form a plurality of light-emitting units; Manufacturing a first electrode on the side of the light-emitting unit away from the substrate; Manufacturing a light collimation unit on the side of the first electrode away from the substrate, and including. The optical collimation unit includes at least one micro-structure, and in a direction away from the substrate, the cross-sectional area of the micro-structure gradually decreases. A method for manufacturing a display panel, characterized by the above. **Claim 20** When the micro-structure includes a nano-structure, the step of manufacturing the nano-structure is as follows. First, form a layer of metal layer on the first electrode, and etch the metal layer to form the nano-structure, or include the step of directly etching the first electrode to form the nano-structure. The manufacturing method according to claim 19, characterized by the above. **Claim 21** When the micro-structure includes a nano-structure, the step of manufacturing the nano-structure is as follows. Form a photoresist pattern on the side of the first electrode away from the substrate, where the photoresist pattern includes a plurality of sub-patterns, and the cross-sectional area of the sub-patterns gradually decreases. Use the photoresist pattern as a mask to dry-etch the first electrode, and transfer the topography of the photoresist pattern to the first electrode to form the nano-structure. The manufacturing method according to claim 19, characterized by the above. ​

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