Micro LED display panel and manufacturing method thereof

Abstract

The application provides a Micro LED display panel and a manufacturing method thereof. The Micro LED display panel comprises a driving substrate, a plurality of Micro LED chips, a pixel definition layer, and a plurality of collimating structures. The application sets a plurality of openings in the pixel definition layer, and sets each Micro LED chip and each collimating structure in each opening, so that the light generated by the Micro LED chip is emitted at a small angle after the collimating effect of the collimating structure, to realize the small-angle display of the Micro LED display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a Micro LED display panel and its manufacturing method. Background Technology

[0002] Currently, most flat panel displays are wide-viewing-angle displays, with a viewing angle generally greater than 120 degrees. In certain specialized fields, such as head-up displays (HUDs), to avoid users having to frequently move their eyes to obtain information, it is necessary to present the displayed content only within the user's direct line of sight. Therefore, there is a certain demand for flat panel displays with a narrower viewing angle.

[0003] However, in Micro LED display panels, the light beams emitted by Micro LED chips are usually quite divergent, which not only makes it difficult to achieve a small viewing angle, but also easily leads to light crosstalk between adjacent chips.

[0004] Technical issues

[0005] This invention provides a Micro LED display panel and its manufacturing method, aiming to reduce the viewing angle of the Micro LED display panel.

[0006] Technical solutions

[0007] This invention provides a Micro LED display panel, comprising: a driving substrate; a plurality of Micro LED chips disposed on the driving substrate and arranged in an array on the driving substrate; a pixel definition layer disposed on the driving substrate, the pixel definition layer having a plurality of openings, each Micro LED chip being located within each of the openings; a plurality of collimation structures corresponding one-to-one with the plurality of Micro LED chips, each collimation structure being disposed in each of the openings; each collimation structure comprising an interconnected substrate and a curved lens, the substrate filling the openings, and the curved lens being disposed on the side of the substrate away from the Micro LED chips.

[0008] The Micro LED display panel further includes a reflective layer disposed on the inner wall of each of the openings.

[0009] The Micro LED display panel further includes a light-shielding layer, which is disposed on the side of the pixel definition layer away from the driving substrate, and the light-shielding layer is distributed between two adjacent collimation structures.

[0010] The Micro LED display panel further includes a protective layer that covers the plurality of collimating structures and the light-shielding layer, and the refractive index of the protective layer is less than that of the curved lens.

[0011] Wherein, the height of the substrate above the pixel definition layer is equal to the thickness of the light-shielding layer.

[0012] The Micro LED display panel further includes a distributed Bragg reflector disposed between the driving substrate and the plurality of Micro LED chips.

[0013] The curved lens includes a Fresnel lens or a spherical lens.

[0014] The opening has an inverted trapezoidal cross-sectional shape in the thickness direction of the pixel definition layer.

[0015] The present invention also provides a method for manufacturing a Micro LED display panel, comprising: providing a driving substrate; forming a pixel definition layer having a plurality of openings on the driving substrate; forming a plurality of Micro LED chips arranged in an array on the driving substrate, each Micro LED chip being located within each of the openings; forming a collimation structure corresponding to each Micro LED chip in each opening, the collimation structure comprising an interconnected substrate and a curved lens, the substrate filling the opening, and the curved lens being formed on the side of the substrate away from the Micro LED chip.

[0016] The step of forming a pixel definition layer with multiple openings on the driving substrate further includes forming a reflective layer on the inner wall of each opening.

[0017] The step of forming a pixel definition layer with multiple openings on the driving substrate includes: forming a negative photoresist layer on the driving substrate; patterning the negative photoresist layer to form multiple vias in the negative photoresist layer; filling the vias with pixel definition material; and removing the remaining negative photoresist layer.

[0018] The step of forming a collimation structure corresponding to each Micro LED chip in each of the openings includes: filling the pixel definition layer and the openings with substrate material, imprinting the substrate material by nanoimprinting, forming the curved lens above the Micro LED chip, and forming the substrate in the openings.

[0019] Beneficial effects

[0020] The beneficial effects of the present invention are as follows: The Micro LED display panel and its manufacturing method provided by the present invention, by setting a pixel definition layer with multiple openings on the driving substrate, by setting Micro LED chips in an array on the driving substrate, and setting each Micro LED chip in each opening, since the opening is also filled with a collimation structure, the light generated by the Micro LED chip is collimated by the curved lens of the collimation structure and then emitted at a small angle, thereby realizing the small-angle display of the Micro LED display panel. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the present invention, the drawings used in the description of the various embodiments made according to the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figures 1A to 1D This is a cross-sectional structural diagram of the Micro LED display panel provided in an embodiment of the present invention;

[0023] Figures 2A-2B This is a cross-sectional schematic diagram of the collimation structure provided in an embodiment of the present invention;

[0024] Figure 3 This is a schematic flowchart of the method for manufacturing a Micro LED display panel according to an embodiment of the present invention;

[0025] Figures 4A to 4J This is a cross-sectional structural diagram of the Micro LED display panel provided in the embodiments of the present invention at each stage of the manufacturing method.

[0026] Embodiments of the present invention

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0032] Please see Figure 1A , Figure 1A This is a cross-sectional structural diagram of a Micro LED display panel 10 provided in an embodiment of the present invention, as shown below. Figure 1A As shown, the Micro LED display panel 10 includes a driving substrate 11, multiple Micro LED chips 12, a pixel definition layer 13, and multiple collimation structures 15.

[0033] Multiple Micro LED chips 12 are disposed on the driving substrate 11 and arranged in an array on the driving substrate 11. Specifically, the driving substrate 11 is a TFT (Thin Film Transistor) glass substrate. The driving substrate 11 is provided with a driving circuit (not shown in the figure) and electrodes 111 corresponding to the Micro LED chips 12. The Micro LED chips 12 are electrically connected to the electrodes 111, so that the multiple Micro LED chips 12 are driven by the driving circuit on the driving substrate 11, and each Micro LED chip 12 can be lit individually by the driving circuit. The emission angle of the Micro LED chip 12 is not less than 120°. Therefore, it is generally not easy to realize small-angle display of the display panel. Furthermore, after the Micro LED chips 12 are arrayed, the light generated by two adjacent Micro LED chips 12 will also cause crosstalk interference. Therefore, in this embodiment of the invention, a pixel definition layer 13 and multiple collimation structures 15 are also provided to realize small-angle display of the Micro LED display panel 10.

[0034] The pixel definition layer 13 is disposed on the driving substrate 11. The pixel definition layer 13 has multiple openings (not labeled in the figure), and each Micro LED chip 12 is located in each opening. The multiple openings in the pixel definition layer 13 are used to define the positions of the multiple Micro LED chips 12 on the driving substrate 11. Therefore, the multiple openings can also be arranged in an array in the pixel definition layer 13. Multiple collimation structures 15 correspond one-to-one with the multiple Micro LED chips 12, and each collimation structure 15 is disposed in each opening. The collimation structure 15 includes an interconnected substrate 151 and a curved lens 152. The substrate 151 fills the opening, and the curved lens 152 is disposed on the side of the substrate 151 away from the Micro LED chip 12. Since the substrate 151 fills the opening, the substrate 151 can further fix the Micro LED chip 12 disposed in the opening, thereby placing it on the light-emitting path of the Micro LED chip 12. By utilizing the refraction effect of the convex curved surface on the curved lens 152 on the light, the divergence angle of the light after being collimated by the collimation structure 15 can be reduced, thereby reducing the viewing angle of the Micro LED display panel 10 from 120° to 90° and below, thus realizing the small-angle display of the Micro LED display panel 10. At the same time, since the divergence angle of the light emitted by the Micro LED chip 12 has been reduced after being collimated by the collimation structure 15, the light crosstalk problem between two adjacent Micro LED chips 12 is alleviated to a certain extent.

[0035] The Micro LED display panel 10 may further include a reflective layer 14 disposed on the inner wall 131 of each opening. Because a reflective layer 14 is disposed on the inner wall 131 of each opening, light emitted by the Micro LED chip 12 and directed towards the inner wall 131 is reflected by the reflective layer 14, thereby changing the path of light propagation. This allows light that was originally emitted at a larger angle to be emitted at a smaller angle after reflection by the reflective layer 14. Specifically, the reflective layer 14 may be made of a metallic material, such as silver or other metallic materials that reflect light. Furthermore, to ensure that the reflective layer 14 reflects light outwards rather than inwards, in this embodiment, it is preferable that the cross-sectional shape of the opening in the thickness direction of the pixel definition layer 13 is an inverted trapezoid, that is, the opening width on the side facing the driving substrate 11 is smaller than the opening width on the side facing away from the driving substrate 11.

[0036] Because the inner wall 131 of the opening is provided with a reflective layer 14 and the opening is also filled with a collimation structure 15, part of the light generated by the Micro LED chip 12 is collimated by the curved lens 152 of the collimation structure 15 and then emitted at a small angle. The other part is reflected by the reflective layer 14 and then changes its light path to enter the curved lens 152. It is also collimated by the curved lens 152 and then emitted at a small angle, thus realizing the small-angle display of the Micro LED display panel.

[0037] For details, please refer to Figure 2A , Figure 2A This is a cross-sectional structural diagram of the collimation structure 15 provided in an embodiment of the present invention, as shown below. Figure 2A As shown, the light-emitting surface 1521 of the curved lens 152 includes a convex curved surface, and the curved lens 152 may specifically include, for example... Figure 2A The Fresnel lens shown, in which Figure 2A The elliptical arc surface at the center of a Fresnel lens corresponds to a convex surface. Also, please refer to... Figure 2B , Figure 2B This is another cross-sectional view of the collimation structure 15 provided in this embodiment of the invention, as shown below. Figure 2B As shown, the curved lens 152 may specifically include, as Figure 2B The spherical lens shown, wherein Figure 2B The spherical surface of the spherical lens shown corresponds to a convex surface. This convex surface refracts different rays of light in a converging manner, thereby reducing the divergence angle of the light rays.

[0038] It should be further noted that the collimation structure 15 is integrally formed. Figure 2A and Figure 2B The dashed line shown is the boundary line defining the curved lens 152 and the substrate 151, and does not indicate that the substrate 151 and the curved lens 152 are detachably connected. In this embodiment, the substrate 151 and the curved lens 152 are made of the same material, which may specifically include epoxy resin. When the material of the substrate 151 includes epoxy resin, the substrate 151 can specifically bond and fix the Micro LED chip 12 in the opening.

[0039] based on Figure 1A For the structure shown in the figure, please refer to Figure 1B This invention also provides a cross-sectional structural diagram of another Micro LED display panel 10. (Compared to...) Figure 1A Compared to the Micro LED display panel 10 shown in the image, Figure 1BThe Micro LED display panel 10 shown also includes a light-shielding layer 16, which is disposed on the side of the pixel definition layer 13 away from the driving substrate 11, and the light-shielding layer 16 is distributed between two adjacent collimation structures 15.

[0040] The light-shielding layer 16 may specifically include a black epoxy resin material or other opaque materials. The function of the light-shielding layer 16 is to enhance the contrast of the Micro LED display panel 10, improve the display effect of the Micro LED display panel 10, and further solve the problem of light emission crosstalk in the Micro LED display panel 10.

[0041] Specifically, the area between two adjacent collimation structures 15 is a non-light-emitting area. The presence of more light in the non-light-emitting area will result in a lower contrast ratio for the Micro LED display panel 10. To improve the contrast ratio, the light-shielding layer 16 absorbs all or most of the light emitted by the Micro LED chip 12 and directed towards the non-light-emitting area. This not only improves the contrast ratio of the Micro LED display panel 10 but also prevents interference between the light emitted by two adjacent Micro LED chips 12 in the non-light-emitting area, further solving the problem of light output crosstalk in the Micro LED display panel 10.

[0042] The height of the substrate 151 above the pixel definition layer 13 is equal to the thickness of the light-shielding layer 16.

[0043] Specifically, by setting the height of the substrate 151 above the pixel definition layer 13 to be equal to the thickness of the light-shielding layer 16, the light emitted from the Micro LED chip 12 can change its propagation path after being reflected by the reflective layer 14. This allows the light that originally shone at the reflective layer 14 with a large divergence angle to exit at a smaller angle after being reflected, while other light that also shone at a large divergence angle towards the non-light-emitting area can be absorbed by the light-shielding layer 16, thereby improving the contrast of the Micro LED display panel 10.

[0044] based on Figure 1A and Figure 1B For the structure in [the document], please refer to [the document]. Figure 1C This invention also provides a cross-sectional structural diagram of another Micro LED display panel 10. (Compared to...) Figure 1A and Figure 1B Compared to the Micro LED display panel 10 shown in the image, Figure 1CThe Micro LED display panel 10 shown also includes a distributed Bragg reflection (DBR) 17 disposed between the driving substrate 11 and the plurality of Micro LED chips 12. It should be noted that the placement of the distributed Bragg reflection 17 is not necessarily related to the placement of the light-shielding layer 16; therefore, in this embodiment of the invention, it can also be directly placed on... Figure 1A The structure shown in the figure includes an additional distributed Bragg reflector 17.

[0045] The distributed Bragg reflector 17 functions to reflect the light emitted from the bottom surface of the Micro LED chip 12 upwards, that is, to reflect the light emitted by the Micro LED chip 12 towards the substrate 11 in a direction away from the substrate 11, thereby improving the utilization rate of the light emitted by the Micro LED chip 12 and further improving the luminous brightness of the Micro LED display panel 10. Specifically, the distributed Bragg reflector 17 is a periodic structure composed of two materials with different refractive indices arranged alternately. The optical thickness of each layer of material is 1 / 4 of the central reflection wavelength, equivalent to a set of photonic crystals. Since electromagnetic waves with frequencies falling within the bandgap cannot penetrate, the reflectivity of the distributed Bragg reflector 17 can reach over 99%. In this embodiment, the distributed Bragg reflector 17 may specifically include titanium oxide and silicon oxide materials. Since the distributed Bragg reflector 17 does not contain metal materials, compared with metal reflectors, the distributed Bragg reflector 17 does not have absorption problems, and its reflection effect is better than that of metal reflectors.

[0046] based on Figure 1B as well as Figure 1C For the structure in [the document], please refer to [the document]. Figure 1D This invention also provides a cross-sectional structural diagram of another Micro LED display panel 10. (Compared to...) Figure 1B and Figure 1C Compared to the Micro LED display panel 10 shown in the image, Figure 1D The Micro LED display panel 10 shown also includes a protective layer 18. It should be noted that the protective layer 18 is not necessarily related to the arrangement of the distributed Bragg reflector 17; therefore, in this embodiment of the invention, it can also be directly integrated into the display panel. Figure 1B A protective layer 18 is added to the structure shown in the figure.

[0047] The protective layer 18 serves to ensure the flatness of the Micro LED display panel 10 and further reduce the light emission angle of the Micro LED chip 12. The protective layer 18 covers the plurality of collimating structures 15 and the light-shielding layer 16, and the refractive index of the protective layer 18 is less than the refractive index of the curved lens 152.

[0048] Specifically, the preferred range for the refractive index of the protective layer 18 is 1 to 1.41, and the preferred range for the refractive index of the curved lens 152 is 1.54 to 2. By setting the refractive index of the protective layer 18 to be less than that of the curved lens 152, when light enters the protective layer 18 through the curved lens 152, since it is a high-refractive-index medium incident on a low-refractive-index medium, according to the law of refraction, the divergence angle of the light is further reduced.

[0049] Based on the aforementioned Micro LED display panel, this invention also provides a method for manufacturing a Micro LED display panel, such as... Figure 3 As shown, the manufacturing method may include the following steps:

[0050] Step S101: Provide a driving substrate.

[0051] The cross-sectional structure diagram of the Micro LED display panel after step S101 is shown below. Figure 4A As shown.

[0052] Specifically, the driving substrate 11 is a TFT (Thin Film Transistor) glass substrate, on which a driving circuit (not shown) and electrodes 111 are formed. The electrodes 111 are used to connect the driving substrate 11 to the Micro LED chip 12 (displayed on...). Figure 4I Electrical connection. A DBR reflector is also formed on this driving substrate. Figure 4A Not shown in the image, please refer to [the image / reference]. Figures 1C-1D (17) The DBR mirror is formed between the electrode and the driving substrate 11, specifically by vapor deposition on the driving substrate 11.

[0053] Step S102: A pixel definition layer with multiple openings is formed on the driving substrate.

[0054] Specifically, step S102 may include the following steps:

[0055] Step 1: Form a negative photoresist layer 19 on the driving substrate 11.

[0056] The cross-sectional structure diagram of the Micro LED display panel after the first step is shown below. Figure 4B As shown.

[0057] Specifically, the negative photoresist layer 19 can be coated onto the driving substrate 11 by spin coating. The negative photoresist layer 19 includes long-chain high-molecular organic materials; for example, the negative photoresist layer 19 may include cis-polyisoprene and a radiation-sensitive crosslinking agent.

[0058] Step 2: Pattern the negative photoresist layer 19 to form a plurality of vias 190 in the negative photoresist layer 19.

[0059] The cross-sectional structure diagram of the Micro LED display panel after the second step is shown below. Figure 4C As shown.

[0060] Specifically, patterning the negative photoresist layer 19 involves exposing the negative photoresist layer 19 using a mask with a preset pattern, and then removing a portion of the negative photoresist layer 19 after exposure. Specifically, taking a negative photoresist layer 19 containing cis-polyisoprene and an irradiation-sensitive crosslinking agent as an example, the exposed cis-polyisoprene crosslinks under the action of the crosslinking agent, becoming a three-dimensional polymer and solidifying, insoluble in the developer. A portion of the unexposed negative photoresist layer 19 (not shown in the figure) dissolves in the developer (xylene) and is thus removed, forming an opening 190. A portion of the exposed photoresist layer 19 remains on the driving substrate 11 as the remaining negative photoresist layer 19R. This remaining negative photoresist layer 19R is used to cover the electrode 111, preventing damage to the electrode 111 in subsequent processes. The remaining negative photoresist layer 19R is also used to be removed in subsequent processes to form an opening at its location to accommodate a light-emitting device.

[0061] In this embodiment, utilizing the characteristics of the negative photoresist layer 19, the top of the negative photoresist layer 19 receives a larger exposure, resulting in a larger width at the top after development, while the bottom of the negative photoresist layer 19 receives a smaller exposure, resulting in a smaller width at the bottom after development, thus forming... Figure 4C The remaining negative photoresist layer 19R has an inverted trapezoidal structure. The height of this inverted trapezoidal structure ranges from 20 to 50 μm.

[0062] Step 3: Fill the through hole 190 with pixel definition material.

[0063] The cross-sectional structure diagram of the Micro LED display panel after the third step is shown below. Figure 4D As shown.

[0064] Specifically, the pixel defining material may include epoxy resin. After filling the via 190, the pixel defining material forms a pixel defining layer 13 on the substrate 11. The process of filling the via 190 with pixel defining material typically also involves covering the remaining negative photoresist layer 19R with another layer of pixel defining material. Therefore, the process of filling the via 190 with pixel defining material also includes removing excess pixel defining material outside the via 190, thereby exposing the surface of the remaining negative photoresist layer 19R.

[0065] Step 4: Remove the remaining negative photoresist layer 19R.

[0066] The cross-sectional structure diagram of the Micro LED display panel after the fourth step is shown below. Figure 4E As shown.

[0067] Specifically, since the remaining negative photoresist layer 19R after development in the second step has an inverted trapezoidal structure, after removing the remaining negative photoresist layer 19R, multiple openings 130 will be formed in the pixel definition layer 13, and the cross-sectional shape of the opening 130 in the thickness direction of the pixel definition layer 13 is an inverted trapezoidal structure, exposing the electrode 111.

[0068] After step S102 is completed, the manufacturing method may further include forming a reflective layer 14 on the inner wall 131 of each opening 130.

[0069] The step of forming a reflective layer 14 on the inner wall 131 of each opening 130 may specifically include the following steps:

[0070] Step 1: Deposit reflective material 14' on the surface of the pixel definition layer 13, the inner wall 131 of the opening 130, and the surface of the driving substrate 11 not covered by the pixel definition layer 13. A cross-sectional view of the Micro LED display panel after this step is shown below. Figure 4F As shown.

[0071] Specifically, the reflective material 14' may include a metallic material, such as silver or other reflective materials. When the reflective material 14' is selected as silver, it can be deposited by vapor deposition. It should be further noted that since the driving substrate 11 also has electrodes 111, corresponding reflective material 14' is also deposited on the electrodes 111, which needs to be removed in subsequent processes.

[0072] Step 2: Form a positive photoresist layer 21 on the reflective material 14'. A cross-sectional view of the Micro LED display panel after this step is shown below. Figure 4G As shown.

[0073] Specifically, the positive photoresist layer 21 includes diazoquinone and alkali-soluble phenolic resin.

[0074] Step 3: Pattern the positive photoresist layer 21 to remove the positive photoresist layer on the bottom of the opening 130.

[0075] Specifically, the exposed positive photoresist layer 21 can be removed using a developer containing an alkaline substance such as sodium hydroxide. When the positive photoresist layer 21 includes diazonium quinone and alkali-soluble phenolic resin, the exposed diazonium quinone degrades and dissolves in the developer along with the phenolic resin. In the step of patterning the positive photoresist layer 21, it is possible to select and retain the positive photoresist layer 21 on the inner wall 131, while also selecting and retaining the positive photoresist layer 21 located on top of the pixel definition layer 13; or, it is possible to select and retain only the positive photoresist layer 21 on the inner wall 131.

[0076] Step 4: Remove the reflective material 14' that is not covered by the positive photoresist layer 21.

[0077] Specifically, since a positive photoresist layer 21 is covered on the reflective material 14' at least on the inner wall 131 after patterning, an inductively coupled plasma (ICP) etching process can be used, with the remaining positive photoresist layer 21 as a mask, to etch away the reflective material 14' that is not covered by the positive photoresist layer 21, thereby forming a reflective layer 14 at least on the inner wall 131 of the opening 130. By removing the reflective material 14' at the bottom of the opening 130, the reflective material 14' covering the electrode 111 can be removed, avoiding short circuits in the electrode 111 when the reflective material 14' is a conductive material, or preventing the Micro LED chip and the electrode 111 from being electrically connected when the reflective material 14' is an insulating material.

[0078] Since the positive photoresist layer 21 can also be retained on the top of the pixel definition layer 13, a reflective layer 14 can also be formed on the top of the pixel definition layer 13. It should be further noted that when the reflective layer 14 is formed only on the inner wall 131 of the opening, since there is no reflective layer 14 on the top of the pixel definition layer 13, the pixel definition layer 13 can directly contact and bond with the subsequent substrate material, thus making it more advantageous for the subsequent substrate material to cover the pixel definition layer 13.

[0079] Step 5: Remove the positive photoresist layer 21 covering the remaining reflective material 14'. The cross-sectional structure of the Micro LED display panel after this step is shown in the diagram below. Figure 4H As shown.

[0080] Step S103: A plurality of Micro LED chips are formed in an array on the driving substrate, with each Micro LED chip located in each of the openings.

[0081] The cross-sectional structure diagram of the Micro LED display panel after step S103 is shown below. Figure 4I As shown.

[0082] Specifically, a Micro LED chip 12 with solder on its surface can be transferred to the electrodes 111 of the driving substrate 11 using an elastic adhesive film with raised surfaces. The Micro LED chip 12 is then heated to melt the solder and weld it to the electrodes, thereby achieving an electrical connection between the Micro LED chip 12 and the electrodes 111 on the driving substrate 11. Afterward, the elastic adhesive film is removed to transfer the Micro LED chip 12 onto the driving substrate 11.

[0083] Step S104: Form a collimation structure corresponding to each Micro LED chip in each opening. The collimation structure includes an interconnected substrate and a curved lens. The substrate fills the opening, and the curved lens is formed on the side of the substrate away from the Micro LED chip.

[0084] After step S104 is completed, the cross-sectional structure diagram of the Micro LED display panel can be referred to as follows: Figures 1A-1D The diagram shows a cross-sectional structure.

[0085] Specifically, step S104 can be divided into the steps of filling the opening 130 with substrate material and forming a curved lens on the substrate material. Figure 4I Based on this, substrate material 15' can be filled into the pixel definition layer 13 and the opening 130. After this step, the cross-sectional structure of the Micro LED display panel is shown in the figure. Figure 4J As shown. Then, using a mold with curved recesses, the substrate material 15' is imprinted via nanoimprinting, forming a curved lens 152 above the Micro LED chip 12, and a substrate 151 in the opening 130, thereby forming... Figure 1A The cross-sectional structure of the Micro LED display panel is shown in the figure.

[0086] In this embodiment, before performing step S103, the fabrication method may further include forming a light-shielding layer 16 on the pixel definition layer 13, which is formed by nanoimprint lithography. Therefore, this fabrication method can ultimately form a layer as shown in the image. Figures 1B-1C The cross-sectional structure of the Micro LED display panel is shown.

[0087] In this embodiment, after performing step S104, the fabrication method may further include forming a protective layer 18 on the collimation structure 15 and the light-shielding layer 16. Therefore, this fabrication method can ultimately form a structure as shown in the image. Figure 1D The cross-sectional structure of the Micro LED display panel is shown.

[0088] The Micro LED display panel and its manufacturing method provided by the present invention achieve small-angle display of the Micro LED display panel by setting a pixel definition layer with multiple openings on a driving substrate, setting Micro LED chips in an array on the driving substrate, and setting each Micro LED chip in each opening, with a collimation structure filling the opening. The light generated by the Micro LED chip is collimated by the curved lens of the collimation structure and then emitted at a small angle.

[0089] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitutions or equivalent replacements fall within the protection scope claimed by the present invention.

[0090] In summary, although the preferred embodiments of the present invention have been disclosed above, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A Micro LED display panel, comprising: Drive substrate; Multiple Micro LED chips are disposed on the driving substrate and arranged in an array on the driving substrate; A pixel definition layer is disposed on the driving substrate, the pixel definition layer having multiple openings, and each MicroLED chip being located within each opening; Multiple collimation structures are provided, each corresponding to one of the multiple Micro LED chips, with each collimation structure disposed in each of the openings; each collimation structure includes an interconnected substrate and a curved lens, the substrate filling the opening, and the curved lens disposed on the side of the substrate away from the Micro LED chip; The Micro LED display panel further includes a light-shielding layer, which is disposed on the side of the pixel definition layer away from the driving substrate and distributed between two adjacent collimation structures. The light-shielding layer is in contact with the pixel definition layer, and the height of the substrate above the pixel definition layer is equal to the thickness of the light-shielding layer.

2. The Micro LED display panel according to claim 1, wherein, The Micro LED display panel further includes a reflective layer disposed on the inner wall of each of the openings.

3. The Micro LED display panel according to claim 1, wherein, The Micro LED display panel further includes a protective layer that covers the plurality of collimating structures and the light-shielding layer, and the refractive index of the protective layer is less than that of the curved lens.

4. The Micro LED display panel according to claim 1, wherein, The Micro LED display panel also includes a distributed Bragg reflector disposed between the driving substrate and the plurality of Micro LED chips.

5. The Micro LED display panel according to claim 1, wherein, The curved lens includes a Fresnel lens or a spherical lens.

6. The Micro LED display panel according to claim 1, wherein, The opening has an inverted trapezoidal cross-sectional shape in the thickness direction of the pixel definition layer.

7. A method for manufacturing a Micro LED display panel, wherein, The method for fabricating the MicroLED display panel as described in any one of claims 1 to 6 includes: Provide driving substrate; A pixel definition layer with multiple openings is formed on the driving substrate; Multiple Micro LED chips are formed in an array on the driving substrate, with each Micro LED chip located within each of the openings; A collimation structure corresponding to each Micro LED chip is formed in each of the openings. The collimation structure includes an interconnected substrate and a curved lens. The substrate fills the opening, and the curved lens is formed on the side of the substrate away from the Micro LED chip.

8. The manufacturing method according to claim 7, wherein, After the step of forming a pixel definition layer with multiple openings on the driving substrate, the method further includes: A reflective layer is formed on the inner wall of each opening.

9. The manufacturing method according to claim 7, wherein, The step of forming a pixel definition layer with multiple openings on the driving substrate includes: A negative photoresist layer is formed on the driving substrate; The negative photoresist layer is patterned to form a plurality of vias in the negative photoresist layer; The through-hole is filled with pixel-defined material; Remove the remaining negative photoresist layer.

10. The manufacturing method according to claim 7, wherein, The step of forming a collimation structure corresponding to each Micro LED chip in each of the openings includes: A substrate material is filled on the pixel definition layer and in the opening. The substrate material is imprinted by nanoimprinting to form the curved lens above the Micro LED chip and the substrate is formed in the opening.

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