Micro LED microdisplay chips and their manufacturing methods

Abstract

This application relates to the field of LED display technology, specifically disclosing a Micro LED microdisplay chip and its manufacturing method, including a driving panel, multiple LED units, a first microlens array, and a second microlens array; multiple LED units are arranged on the driving panel, each LED unit has a corresponding LED mesa and can be driven individually by the driving panel; the first microlens array is located on the side of the LED units away from the driving panel, and includes multiple first microlens units corresponding one-to-one with the multiple LED units, the first microlens units being used to converge and / or collimate the light emitted by the LED units; the second microlens array is located on the side of the first microlens array away from the LED units, the second microlens array including multiple second microlens units corresponding one-to-one with the multiple first microlens units, the second microlens units being used to converge and / or collimate the light emitted from the first microlens units.

Description

Technical Field

[0001] This application belongs to the field of LED display technology, specifically relating to a Micro LED microdisplay chip and its manufacturing method. Background Technology

[0002] Currently, the light emitted by LED units often has a wide angular distribution, with a high proportion of large-angle light. This dispersed light reduces the effective amount of light entering the human eye. Furthermore, large-angle light is prone to stray reflections during transmission, further exacerbating glare and reducing contrast in the image. Summary of the Invention

[0003] In view of this, this application provides a Micro LED microdisplay chip and its manufacturing method, the main purpose of which is to reduce the dispersion of light at large angles.

[0004] To achieve the above objectives, this application mainly provides the following technical solutions: One aspect of this application provides a Micro LED microdisplay chip, comprising: Driver panel; Multiple LED units are arranged on the driving panel, each LED unit has a corresponding LED platform and can be driven individually by the driving panel; A first microlens array is located on the side of the LED unit away from the driving panel. The first microlens array includes a plurality of first microlens units corresponding one-to-one with the plurality of LED units. The first microlens units are used to focus and / or collimate the light emitted by the LED units. The second microlens array is located on the side of the first microlens array away from the LED unit. The second microlens array includes a plurality of second microlens units that correspond one-to-one with the plurality of first microlens units. The second microlens units are used to focus and / or collimate the light emitted from the first microlens units.

[0005] Optionally, both the first microlens unit and the second microlens unit are plano-convex lens structures, and the convex surfaces of both are arranged in a direction away from the driving panel, while the planar surfaces are arranged in a direction close to the driving panel. Alternatively, the first microlens unit is a plano-convex lens structure, with its convex surface facing away from the driving panel and its flat surface facing towards the driving panel; the second microlens unit is a plano-convex lens structure, with its convex surface facing towards the driving panel and its flat surface facing away from the driving panel.

[0006] Optionally, the Micro LED microdisplay chip further includes: A diffuse reflection structure is located between the first microlens array and the second microlens array. The diffuse reflection structure has multiple diffuse reflection holes, each corresponding to an LED unit. The diffuse reflection holes and the corresponding first microlens units enclose a diffuse reflection cavity, which is used to diffusely control the large-angle light emitted from the first microlens units.

[0007] Optionally, the second microlens array is formed by fabricating a precursor layer and a lens material layer together; The precursor layer is located on the side of the diffuse reflection structure away from the drive panel, and the lens material layer covers the side of the precursor layer away from the diffuse reflection structure; Each of the second microlens units in the second microlens array is composed of corresponding regions of the precursor layer and the lens material layer.

[0008] Optionally, the hole wall of the diffuse reflection hole is a diffuse reflection surface, and the roughness of the diffuse reflection surface is 5 nanometers to 20 nanometers.

[0009] Optionally, the Micro LED microdisplay chip further includes: A fence structure is located between the LED unit and the first microlens array. The fence structure has multiple grid holes, each of which corresponds one-to-one with the diffuse reflection hole and the LED unit. The grid holes are arranged around the LED platform of the corresponding LED unit, and a recessed area is formed between the LED platform and the inner wall of the corresponding grid hole. The recessed area is used to fill the optical functional layer.

[0010] Optionally, the height of the diffuse cavity is the quotient of the radius of the corresponding optical functional layer divided by tan30°.

[0011] Optionally, the radius of curvature of the first microlens unit and the second microlens unit is both 0.5 micrometers to 20 micrometers; the bottom diameter of the first microlens unit and the second microlens unit is greater than 20% of the diameter of the corresponding optical functional layer; the diameter of the optical functional layer is 1 micrometer to 10.5 micrometers.

[0012] Optionally, the LED unit is used to emit light of a first color; the optical functional layer includes at least: Multiple first wavelength conversion units, each first wavelength conversion unit filling the corresponding recessed region, the first wavelength conversion unit being used to convert the first color light into the second color light; Multiple second wavelength conversion units are provided, each filling a corresponding recessed region, and each second wavelength conversion unit is used to convert the first color light into a third color light.

[0013] Optionally, the optical functional layer further includes: Multiple third wavelength conversion units are provided, which fill the corresponding recessed areas, and are used to convert the first color light into a fourth color light. Alternatively, multiple light-transmitting units, wherein the light-transmitting units fill the corresponding recessed areas, and the light-transmitting units are used to allow the first color light to pass through directly.

[0014] Optionally, the drive panel includes: The first electrode contact serves as a common electrode contact and is connected to the first polarity terminal of all the LED units. Multiple second electrode contacts, which serve as independent control electrode contacts, are respectively connected to the second polarity terminals of the multiple LED units.

[0015] Another aspect of this application provides a method for manufacturing a Micro LED microdisplay chip, comprising: Provide a driver panel; Multiple LED units are formed on the driving panel, each LED unit having a corresponding LED platform and configured to be driven individually by the driving panel; A fence structure with multiple grid holes is formed, wherein each grid hole corresponds to one of the LED units and is arranged around the LED platform, and a recessed area is formed between the LED platform and the inner wall of the corresponding grid hole; An optical functional material is filled into the recessed area to form an optical functional layer; A first microlens array is fabricated on the side of the optical functional layer away from the driving panel. The first microlens array includes a plurality of first microlens units corresponding one-to-one with the plurality of grid holes. Each first microlens unit covers the corresponding grid hole and is configured to converge and / or collimate the light after it has passed through the optical functional layer. A diffuse reflection structure is formed on the side of the fence structure away from the drive panel. The diffuse reflection structure has multiple diffuse reflection holes, each corresponding to a grid hole, and the hole wall of the diffuse reflection hole is formed as a diffuse reflection surface. The diffuse reflection holes and the corresponding first microlens units enclose a diffuse reflection cavity, which is configured to diffusely control the large-angle light emitted from the first microlens units. A second microlens array is fabricated on the side of the diffuse reflection structure away from the driving panel. The second microlens array includes a plurality of second microlens units corresponding one-to-one with the plurality of diffuse reflection holes. Each second microlens unit covers the corresponding diffuse reflection hole and is configured to focus and / or collimate the light emitted from the diffuse reflection cavity.

[0016] Optionally, before filling the recessed area with optical functional material to form an optical functional layer, the method further includes: A reflective layer is formed on the surface of the fence structure.

[0017] Optionally, filling the recessed area with optical functional material to form an optical functional layer includes: A first wavelength conversion material is filled in a first portion of the plurality of recessed regions to form a plurality of first wavelength conversion units, wherein the first wavelength conversion units are used to convert the first color light emitted by the LED unit into a second color light. A second portion of the recessed regions is filled with a second wavelength conversion material to form a plurality of second wavelength conversion units, wherein the second wavelength conversion units are used to convert the first color light emitted by the LED unit into a third color light; In the remaining areas of the plurality of recessed regions, a third wavelength conversion material or a light-transmitting material is selectively filled to form a plurality of third wavelength conversion units or a plurality of light-transmitting units; wherein, if the third wavelength conversion material is filled, the third wavelength conversion unit is used to convert the first color light emitted by the LED unit into a fourth color light; if the light-transmitting material is filled, the light-transmitting unit is used to allow the first color light emitted by the LED unit to pass through directly. The top surfaces of the first wavelength conversion unit, the second wavelength conversion unit, and the third wavelength conversion unit, or the top surfaces of the first wavelength conversion unit, the second wavelength conversion unit, and the light-transmitting unit, are controlled to be flush with or lower than the top surface of the fence structure.

[0018] Optionally, forming a diffuse reflection structure on the side of the fence structure away from the drive panel includes: Photoresist is spin-coated on the side of the fence structure and the optical functional layer away from the driving panel to form a mask layer; A portion of the photoresist in the mask layer corresponding to the grid holes is removed to form an inverted trapezoidal photomask, which is disposed corresponding to the grid holes; A metal layer is formed on the sidewalls and top surface of the inverted trapezoidal photomask, the metal layer including a horizontal metal layer and a sidewall metal layer; Remove the horizontal metal layer and retain the sidewall metal layer, which is the hole wall of the diffuse reflection hole.

[0019] Optionally, fabricating a second microlens array on the side of the diffuse reflection structure away from the driving panel includes: A precursor layer is formed on the side of the sidewall metal layer away from the drive panel; A through-hole is formed in the precursor layer at a position corresponding to the first microlens unit, and the through-hole corresponds to the position of the diffuse reflection hole. Remove the photoresist below the via to form the diffuse reflection cavity, the cross-sectional shape of which is an inverted trapezoid; The through-hole is sealed to form a lens material layer; The lens material layer and the precursor layer are fabricated into a second microlens array.

[0020] Optionally, fabricating a second microlens array on the side of the diffuse reflection structure away from the driving panel includes: Remove a portion of the photoresist from the diffuse reflection hole to form a concave surface; A precursor layer is formed on the side of the concave surface opposite to the drive panel; A through-hole is formed in the precursor layer at a position corresponding to the first microlens unit, and the through-hole corresponds to the position of the diffuse reflection hole. Remove the photoresist below the via to form the diffuse reflection cavity, the cross-sectional shape of which is an inverted trapezoid; The through-hole is sealed to form a lens material layer; The lens material layer and the precursor layer are fabricated into a second microlens array.

[0021] By employing the above technical solution, this application has at least the following beneficial effects: The Micro LED microdisplay chip provided in this embodiment can drive each LED unit individually, enabling precise control of each pixel, thereby improving the display resolution and contrast, and presenting more delicate and vivid images.

[0022] The Micro LED microdisplay chip provided in this application embodiment has an optical functional layer filled in the recessed area, which can perform wavelength conversion on the first color light emitted by the LED unit and convert it into light of other different colors to help achieve full-color display. At the same time, the optical functional layer may also include a light-transmitting unit, allowing the first color light emitted by the LED unit to pass through directly, further enriching the light control methods, flexibly adapting to various display needs, effectively expanding the application range of the Micro LED microdisplay chip, and improving its adaptability and practicality.

[0023] The Micro LED microdisplay chip provided in this application embodiment has a first microlens array that can focus and / or collimate the light after it has passed through the optical functional layer, so that the light is emitted more concentratedly in the vertical direction, thereby reducing light scattering and improving light utilization.

[0024] The Micro LED microdisplay chip provided in this application embodiment has a diffuse reflection cavity formed by the diffuse reflection structure and the first microlens unit, which can diffusely control the large-angle light emitted from the first microlens unit. Light that would otherwise be emitted at a large angle and potentially cause uneven light distribution or waste is adjusted through diffuse reflection and reintegrated into the light output, reducing light loss and making the light distribution more uniform, thus improving display quality.

[0025] The Micro LED microdisplay chip provided in this application embodiment has a second microlens array that can focus and / or collimate the light emitted from the diffuse reflection cavity, further optimizing the light direction and allowing the light to reach the predetermined position more accurately, which helps to improve the clarity and brightness uniformity of the display image.

[0026] The method for manufacturing Micro LED microdisplay chips provided in this application embodiment clearly states that the driving panel can drive each LED unit individually, so that each pixel can be precisely controlled, which helps to improve the resolution and contrast of the display, making the display picture more delicate and vivid, and meeting the requirements of high-quality display.

[0027] The method for manufacturing Micro LED microdisplay chips provided in this application embodiment uses a first microlens array to initially focus and collimate the light, a diffuse reflection cavity to control the diffuse reflection of large-angle light, and a second microlens array to focus and collimate the light a second time. The multi-stage collaboration effectively improves the problem of the wide angle distribution of the light emitted by the LED unit, reduces the phenomenon of high brightness at large angles, makes the light more concentrated and more uniformly distributed, and improves the clarity and brightness uniformity of the display screen.

[0028] The method for manufacturing a Micro LED microdisplay chip provided in this application embodiment fills the recessed area with an optical functional layer, which can perform wavelength conversion on the first color light emitted by the LED unit, converting it into light of other different colors to help achieve full-color display. At the same time, the optical functional layer may also include a light-transmitting unit, allowing the first color light emitted by the LED unit to pass through directly, further enriching the light control methods, flexibly adapting to various display needs, effectively expanding the application range of Micro LED microdisplay chips, and improving their adaptability and practicality.

[0029] The method for manufacturing a Micro LED microdisplay chip provided in this application embodiment utilizes a reflective layer on the surface of the gate structure. This layer effectively blocks light leakage from the sidewalls of the LED unit, preventing ineffective light loss. Simultaneously, the reflective layer reflects light emitted from the LED unit, converging and collimating both reflected and directly emitted light, thereby improving the wavelength conversion efficiency of the optical functional layer and ensuring effective light utilization. Furthermore, the diffuse reflection cavity formed by the diffuse reflection structure and the first microlens unit can adjust potentially wasted large-angle light to an effective emission angle through diffuse reflection, allowing this light to re-participate in the overall light output, significantly reducing light loss and further enhancing the chip's optical performance.

[0030] The method for manufacturing Micro LED microdisplay chips provided in this application embodiment, wherein the top surface of the optical functional layer is flush with or lower than the top surface of the gate structure, can not only effectively prevent light crosstalk between adjacent LED units and ensure independent propagation of light, but also ensure the flatness and stability of the chip structure, which is beneficial to the subsequent production process and indirectly improves the effectiveness of light utilization. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a Micro LED microdisplay chip according to an optional embodiment of this application; Figure 2 for Figure 1 The image shown is a physical picture of the Micro LED microdisplay chip. Figure 3 This is a schematic diagram of the structure of a Micro LED microdisplay chip according to another optional embodiment of this application; Figure 4 for Figure 3 The image shown is a physical picture of the Micro LED microdisplay chip. Figure 5 A flowchart of a manufacturing method according to an optional embodiment of this application; Figure 6 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 7 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 8 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 9 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 10 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 11 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 12 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 13 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 14 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 15 To adopt Figure 5 The manufacturing method shown is used to produce Figure 1 and Figure 2The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 16 To adopt Figure 5 The manufacturing method shown is used to produce Figure 3 and Figure 4 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 17 To adopt Figure 5 The manufacturing method shown is used to produce Figure 3 and Figure 4 The diagram shows a flowchart of one step in the manufacturing process of a Micro LED microdisplay chip. Figure 18 This is a comparison curve of the light emission angle and brightness of the Micro LED microdisplay chip of this application and a traditional lensless structure.

[0032] The reference numerals in the attached figures are as follows: 1. Driver panel; 11. First electrode contact; 12. Second electrode contact; 2. LED unit; 3. Fence structure; 31. Fence hole; 4. Optical functional layer; 41. First wavelength conversion unit; 42. Second wavelength conversion unit; 43. Third wavelength conversion unit; 5. First microlens array; 51. First microlens unit; 6. Diffuse reflection structure; 61. Diffuse reflection hole; 7. Second microlens array; 71. Second microlens unit; 711. Precursor layer; 712. Lens material layer; 8. Reflective layer. Detailed Implementation

[0033] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0034] It should be noted that, in the description of this application, the terms “under,” “below,” “below,” “lower part,” “on,” “above,” “above,” and “upper part” should be interpreted in the broadest sense, meaning that a description containing these terms is interpreted as “a component may be disposed on another component in direct contact, or there may be an intermediate component or layer between the components.”

[0035] As used in this application, the term "layer" refers to a portion of material comprising a region of a certain thickness. A layer may extend over the entire lower or upper structure, or it may extend within a localized area of ​​the lower or upper structure. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure, with a thickness less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically, and / or along a conical surface.

[0036] As described in the background section, in related technologies, the light emitted by LED unit 2 often has a wide angular distribution, resulting in high brightness even at large angles.

[0037] For the above issues, please refer to Figures 1 to 4 As shown, this application embodiment provides a Micro LED microdisplay chip, including a driving panel 1, multiple LED units 2, a first microlens array 5, and a second microlens array 7. Multiple LED units 2 are arranged on the driving panel 1, each LED unit 2 having a corresponding LED mesa and capable of being driven individually by the driving panel 1. The first microlens array 5 is located on the side of the LED units 2 away from the driving panel 1, and includes multiple first microlens units 51 corresponding one-to-one with the multiple LED units 2. The first microlens units 51 are used to converge and / or collimate the light emitted from the LED units 2. The second microlens array 7 is located on the side of the first microlens array 5 away from the LED units 2, and includes multiple second microlens units 71 corresponding one-to-one with the multiple first microlens units 51. The second microlens units 71 are used to converge and / or collimate the light emitted from the first microlens units 51.

[0038] The Micro LED microdisplay chip provided in this application embodiment can drive each LED unit 2 individually with the driving panel 1, enabling precise control of each pixel, thereby improving the display resolution and contrast, and presenting more delicate and vivid images.

[0039] The Micro LED microdisplay chip provided in this application embodiment has a first microlens array 5 located on the side of the LED unit 2 away from the driving panel 1. It can focus and / or collimate the light emitted from the LED unit 2, so that the light is emitted more concentratedly in the vertical direction, thereby reducing light scattering and improving light utilization.

[0040] The Micro LED microdisplay chip provided in this application embodiment has a second microlens array 7 located on the side of the first microlens array 5 away from the LED unit 2. It can focus and / or collimate the light emitted from the first microlens unit 51, further optimize the light direction, and allow the light to reach the predetermined position more accurately, which helps to improve the clarity and brightness uniformity of the display image.

[0041] Further, see Figures 1 to 4 As shown, the Micro LED microdisplay chip also includes a fence structure 3 and a diffuse reflection structure 6. The diffuse reflection structure 6 is located between the first microlens array 5 and the second microlens array 7. The diffuse reflection structure 6 has multiple diffuse reflection holes 61, each corresponding to an LED unit 2. The diffuse reflection holes 61 and the corresponding first microlens unit 51 enclose a diffuse reflection cavity, which is used to diffusely control the large-angle light emitted from the first microlens unit 51. The fence structure 3 is located between the LED unit 2 and the first microlens array 5. The fence structure 3 has multiple grid holes 31, each corresponding to a diffuse reflection hole 61 and an LED unit 2. The grid holes 31 are arranged around the LED mesa of the corresponding LED unit 2. A recessed area is formed between the LED mesa and the inner wall of the corresponding grid hole 31. The recessed area is used to fill the optical functional layer 4.

[0042] In some embodiments, the driving panel 1 may include a substrate, a driving circuit, and a plurality of electrode contacts connected to the driving circuit. The plurality of electrode contacts include a first electrode contact 11 and a plurality of second electrode contacts 12. The first electrode contact 11 is electrically connected to the first polarity terminal of each LED unit 2, and the plurality of second electrode contacts 12 are connected one-to-one with the second polarity terminals of the plurality of LED units 2, so as to achieve the purpose of individually driving any one of the plurality of LED units 2 to emit light.

[0043] In some embodiments, the first electrode contact 11 can be a cathode metal contact, the second electrode contact 12 can be an anode metal contact, the first polarity terminal of the LED unit 2 can be an N-type semiconductor layer, and the second polarity terminal of the LED unit 2 can be a P-type semiconductor layer. In practical applications, the cathode metal contact can serve as a common electrode contact, electrically connected to the N-type semiconductor layer of each LED unit 2 through a continuous conductive layer, and the anode metal contact can serve as an independent control electrode contact, connected one-to-one with the P-type semiconductor layer of the LED unit 2 through patterned metal wiring. It is understood that each independent control electrode contact can be controlled by applying an independent voltage signal through an external driving circuit to achieve switching control or current regulation of a single LED unit 2.

[0044] In some embodiments, multiple LED units 2 can be arranged on the driving panel 1 in a regular or irregular manner, serving as pixels of the Micro LED microdisplay chip. Each LED unit 2 can have multiple LED mesa surfaces corresponding to it. The LED unit 2 can also be referred to as a Micro LED unit. The size of the LED unit 2, i.e., its diameter, is from 0.5 micrometers to 10 micrometers. In a preferred embodiment, the size of the LED unit 2 is less than 5 micrometers.

[0045] In some embodiments, LED unit 2 can be a miniature light-emitting diode or a miniature organic light-emitting diode. The miniature light-emitting diode is formed based on inorganic semiconductor materials, such as gallium nitride, aluminum gallium nitride, gallium arsenide, and aluminum gallium indium phosphide. The miniature organic light-emitting diode is formed based on organic materials, such as small molecules, polymers, and phosphorescent materials.

[0046] In some embodiments, the LED unit 2 may emit a first color light, which includes, but is not limited to, any one of red light, green light, blue light, yellow light, or ultraviolet light.

[0047] In some embodiments, the multiple LED platforms can be in the form of a frustum. The sidewalls of the LED platform can be inclined, and the angle between the sidewall and the top surface of the LED platform can be an obtuse angle, thereby improving the light-gathering effect of the LED unit 2. It is understood that the multiple LED platforms can also be in the form of a columnar structure, in which case the angle between the sidewall and the top surface of the LED platform is a right angle.

[0048] In some embodiments, a fence material layer is further included above the plurality of LED units 2. This fence material layer can be a fence structure 3 with a plurality of grid holes 31. The fence structure 3 includes a plurality of grid holes 31. These grid holes 31 can be arranged in a regular or irregular manner. The number of grid holes 31 can correspond one-to-one with the plurality of LED units 2. The plurality of grid holes 31 can be respectively arranged around the plurality of LED platforms, forming a recessed area between the LED platform and the corresponding grid hole 31. This recessed area can be bowl-shaped or trumpet-shaped.

[0049] In some embodiments, in order to improve the uniformity of light emission from the LED unit 2, the LED unit 2 can be positioned at the center of the grid hole 31, so that the first color light can pass through the grid hole 31 uniformly.

[0050] In some embodiments, the grid holes 31 in the fence material layer can be formed by dry etching. For example, the sidewalls of the grid holes 31 can be etched into bevels, and the angle between the sidewalls of the grid holes 31 and the top surface of the fence structure 3 is an obtuse angle. As an example, see Figures 1 to 4As shown, the cross-sectional size of the grid aperture 31 can gradually increase along the direction of light propagation. The cross-section of the grid aperture 31 is parallel to the light-emitting surface; generally, this cross-section can be circular or square, but it can also be an irregular shape. The structure of the grid aperture 31 can be a bowl-shaped or trumpet-shaped structure, thereby collimating the emitted light from the LED. It should be noted that in this application, there are no specific limitations on the material of the fence structure 3 with multiple grid apertures 31. The material of the fence structure 3 with multiple grid apertures 31 can include organic resin, organic black matrix photoresist, color filter photoresist, and polyimide, etc. It should be noted that by combining the inclined sidewall of the LED platform with the inclined sidewall of the grid aperture 31, the light can undergo multiple reflections on the inclined surfaces of both, further improving the luminous brightness of the LED unit 2.

[0051] In some embodiments, an optical functional layer 4 is provided within the grid holes 31 of the fence structure 3. Specifically, the fence structure 3 has a plurality of grid holes 31 corresponding one-to-one with the LED units 2. The grid holes 31 are arranged around the LED platform of the corresponding LED unit 2, and a recessed area is formed between the LED platform and the inner wall of the grid hole 31. The optical functional layer 4 is filled in the recessed area. The optical functional layer 4 includes a plurality of optical functional units, which correspond one-to-one with the plurality of grid holes 31. Each optical functional unit is individually filled in the recessed area of ​​a corresponding grid hole 31 and is used to perform corresponding optical control on the light emitted by the corresponding LED unit 2. Here, the optical functional unit is, as described below, a wavelength conversion unit that can convert the first color light emitted by the LED unit 2 into different color light, or a light-transmitting unit that allows the first color light to pass through directly.

[0052] In some embodiments, when the size of the LED unit 2 is between 0.5 micrometers and 10 micrometers in diameter, the size of the corresponding optical functional unit, i.e., the diameter, is preferably between 1 micrometer and 10.5 micrometers. It should be noted that the diameter of the optical functional unit is slightly larger than the diameter of the LED unit 2, ensuring complete coverage of the LED platform and surrounding recessed areas, preventing light emitted from the LED unit 2 from escaping directly from the edge of the optical functional layer 4 without being converted. It is understood that when both the LED unit 2 and the optical functional unit are platform-shaped structures, the diameter of the LED unit 2 refers to the lateral dimension of the largest cross-section among all cross-sections of the LED unit 2 along the light propagation direction, and the diameter of the optical functional unit refers to the lateral dimension of the largest cross-section among all cross-sections of the optical functional unit along the light propagation direction.

[0053] In some embodiments, a reflective layer 8 is provided on the surface of the fence structure 3. The reflective layer 8 can not only effectively block light leakage from the sidewall of the LED unit 2, but also reflect the light emitted by the LED unit 2. Furthermore, the fence structure 3 with the reflective layer 8 can also gather and collimate the reflected light from the reflective layer 8 and the light emitted from the LED unit 2, thereby further improving the wavelength conversion efficiency of the optical functional layer 4.

[0054] In some embodiments, the reflective layer 8 can be formed based on the fence structure 3, which can avoid processing in the tiny gaps between the LED units 2 of the Micro LED microdisplay chip, thereby greatly reducing the processing difficulty, widening the process window, improving the processing yield, and can be applied to products with high resolution and high pixel density.

[0055] In some embodiments, the reflective layer 8 may be made of organic materials, including but not limited to highly reflective organic coatings. Alternatively, the reflective layer 8 may be made of inorganic materials, including but not limited to metallic materials such as aluminum, copper, and silver.

[0056] In some embodiments, the reflective layer 8 can be deposited onto the surface of the fence structure 3 by means of atomic layer deposition, chemical vapor deposition, evaporation, sputtering, etc.

[0057] In some embodiments, the surface of the reflective layer 8 can be roughened to form a roughened surface. The roughened reflective layer 8 can increase its light reflectivity. It should be noted that the embodiments of this application do not specifically limit the roughening method of the reflective layer 8. For example, the reflective layer 8 can be roughened by corrosion. Taking aluminum as an example, hydrochloric acid can be used to roughen the reflective layer 8 by corrosion. It should also be noted that the embodiments of this application do not specifically limit the surface structure of the roughened reflective layer 8. The roughened surface of the reflective layer 8 can have an irregular uneven structure or an ordered uneven structure. As an example, the roughened surface of the reflective layer 8 can have a zigzag uneven shape, such as a trapezoidal serration or a serrated shape. As another example, the roughened surface of the reflective layer 8 can also have an arc-shaped uneven shape, such as a wavy shape.

[0058] In some embodiments, the top surface of the optical functional layer 4 may be flush with or lower than the top surface of the fence structure 3. In a preferred embodiment, the top surface of the optical functional layer 4 is flush with the top surface of the fence structure 3. This flush structure can not only effectively prevent light crosstalk between adjacent LED units 2, but also ensure the flatness and stability of the Micro LED microdisplay chip structure, facilitating subsequent manufacturing processes.

[0059] In some embodiments, the first microlens array 5 is located on the upper part of the optical functional layer 4. The first microlens array 5 includes a plurality of first microlens units 51, which correspond one-to-one with a plurality of grid holes 31 and a plurality of LED units 2. Each first microlens unit 51 covers a grid hole 31, ensuring that all light rays in the grid hole 31 can enter the corresponding first lens unit.

[0060] In some embodiments, the first microlens unit 51 can be in the form of a convex mirror, a plano-convex lens, or an aspherical lens, specifically designed according to the light control requirements. In practical applications, the light emitted from the LED unit 2, after being scattered by the optical functional layer 4, often has a relatively dispersed initial angle, possibly ranging from 30 to 60 degrees. The first microlens, through curved surface refraction, can converge these divergent rays towards the optical axis, i.e., in the direction perpendicular to the driving panel 1, reducing the proportion of light diffusing at large angles, such as greater than 30 degrees. Furthermore, for the stray light generated by the scattering of optical functional material particles in the optical functional layer 4, the first microlens can adjust its curvature to convert some of the scattered light into approximately parallel light, concentrating the light emission angle within a smaller range, such as within ±15 degrees, thus reducing the burden on the subsequent diffuse reflection cavity to process large-angle leaked light. In a preferred embodiment, the radius of curvature of the first microlens unit 51 is 0.5 micrometers to 20 micrometers. It should be noted that the optical functional materials mentioned here specifically refer to the materials used to construct the wavelength conversion unit to meet the wavelength conversion requirements, as well as the transparent resin materials used to construct the light-transmitting unit.

[0061] In some embodiments, the material of the first microlens unit 51 includes transparent polymers, inorganic transparent materials, etc., wherein the inorganic transparent materials can be selected from silicon oxide, titanium oxide, aluminum oxide, and various transparent inorganic oxides with a refractive index range of 1.5 to 2.5; the transparent polymers can be selected from materials similar to plastics, covering various suitable organic materials. Specifically, plastic-like transparent polymers can be selected from polymethyl methacrylate, polycarbonate, etc., which are low in cost and easy to form at the micro-nano scale through processes such as photolithography and hot stamping, making them suitable for large-scale mass production. Silicon oxide, titanium oxide, aluminum oxide, and the above-mentioned transparent inorganic oxides have higher high-temperature resistance and chemical stability, which can reduce the degradation of optical performance during long-term operation and are suitable for high-reliability scenarios.

[0062] In some embodiments, the bottom diameter of the first microlens unit 51 is slightly larger than the diameter of the underlying optical functional unit to prevent light leakage from the edges. In a preferred embodiment, the bottom diameter of the first microlens unit 51 is 20% larger than the diameter of the corresponding optical functional unit.

[0063] In some embodiments, the contact surfaces of the first microlens unit 51 and the corresponding optical functional unit are kept flat, and the difference in refractive index between the two needs to be controlled within a reasonable range. For example, the refractive index of the first microlens unit 51 is slightly higher than that of the optical functional unit to reduce interface reflection. For instance, if the refractive index of the optical functional unit is 1.5, the lens can be made of a material with a refractive index of 1.55 to 1.6 to ensure the refractive effect while reducing reflection loss.

[0064] In some embodiments, the upper part of the plurality of first microlens units 51 further includes a diffuse reflection material layer. This diffuse reflection material layer can be a diffuse reflection structure 6 having a plurality of diffuse reflection holes 61. The diffuse reflection structure 6 having a plurality of diffuse reflection holes 61 includes a plurality of diffuse reflection holes 61. The plurality of diffuse reflection holes 61 can be arranged in a regular or irregular manner. The number of diffuse reflection holes 61 can be set in a one-to-one correspondence with the plurality of first microlens units 51. Each diffuse reflection hole 61 covers one first microlens unit 51, forming an independent optical control unit, i.e., a diffuse reflection cavity, to avoid light crosstalk between adjacent pixels.

[0065] In some embodiments, the diffuse reflection hole 61 in the diffuse reflection material layer can be formed using micro-nano fabrication processes. For example, the sidewall of the diffuse reflection hole 61 can be processed into an inclined surface, and the angle between the sidewall of the diffuse reflection hole 61 and the top surface of the diffuse reflection structure 6 is an obtuse angle, so as to increase the contact area between the light and the diffuse reflection surface, so that the incident light undergoes more diffuse reflections on the inclined surface, and the probability of the light escaping directly from the diffuse reflection hole 61 or shining directly out is reduced.

[0066] In some embodiments, the cross-sectional dimensions of the diffuse reflection aperture 61 can gradually increase along the direction of light propagation. The cross-section of the diffuse reflection aperture 61 is parallel to the light-emitting surface; generally, this cross-section can be circular or square, but it can also be an irregular shape. The structure of the diffuse reflection aperture 61 can be a bowl-shaped or trumpet-shaped structure, thereby enabling more efficient angle control of the light entering the diffuse reflection cavity, improving light utilization and emission uniformity.

[0067] In some embodiments, the diffuse reflection structure 6 having multiple diffuse reflection holes 61 can be made of a high-reflectivity material, such as aluminum, silver, or other metallic materials. Such materials, after surface roughening treatment, can form a highly efficient diffuse reflection surface, which can fully reflect incident light and reduce energy absorption loss.

[0068] In some embodiments, the roughness of the diffuse reflection surface formed by the aperture wall of the diffuse reflection aperture 61 is 5 nanometers to 20 nanometers. In a preferred embodiment, the roughness of the diffuse reflection surface is greater than 8 nanometers, which ensures uniform diffuse reflection of light without excessive scattering of light due to excessive roughness, thus avoiding loss of directionality and balancing reflection uniformity with the stability of subsequent optical control.

[0069] In some embodiments, the diffuse reflection aperture 61 and the corresponding first microlens unit 51 enclose a diffuse reflection cavity. The height of the diffuse reflection cavity is the quotient of the radius of the corresponding optical functional unit divided by tan30°. This ensures that large-angle light rays emitted from the first microlens unit 51 with a divergence angle greater than 30 degrees can be captured by the inner wall of the diffuse reflection cavity, thereby avoiding light rays from escaping directly from the cavity due to insufficient cavity height.

[0070] In some embodiments, in order to ensure that the propagation path of light is precisely aligned between the structural layers and to reduce light leakage or control failure caused by axial offset, the axial center line of the diffuse reflection aperture 61 and the grid aperture 31 can be coincided. This allows the light emitted from the LED unit 2, the light after the optical functional layer 4, and the light after the initial control by the first microlens unit 51 to enter the diffuse reflection cavity along the same axial direction. This ensures that large-angle light is uniformly captured and controlled by the diffuse reflection surface, while also ensuring that the light emitted from the diffuse reflection cavity can accurately enter the corresponding second microlens unit 71, thereby improving the overall synergy and light utilization of the optical system.

[0071] In some embodiments, the second microlens array 7 is located on the upper part of the diffuse reflection structure 6. The second microlens array 7 includes a plurality of second microlens units 71, which correspond one-to-one with a plurality of diffuse reflection apertures 61, a plurality of grid apertures 31, and a plurality of LED units 2. Each second microlens unit 71 covers a diffuse reflection aperture 61, ensuring that all light emitted from the diffuse reflection cavity can enter the second microlens unit 71 for regulation.

[0072] In some embodiments, the second microlens array 7 is located on the side of the diffuse reflection structure 6 away from the driving panel 1, and its bottom surface can be in direct contact with the top surface of the diffuse reflection structure 6 or bonded through a transparent adhesive layer, such as optical adhesive, to ensure that there is no additional air gap in the light propagation path that causes reflection loss.

[0073] In some embodiments, to reduce light control deviation, the axis of the second microlens unit 71 coincides with the axis of the corresponding diffuse reflection aperture 61, grid aperture 31 and LED unit 2, forming a coaxial optical path. This avoids light deflection caused by eccentricity and ensures that the light reflected by the diffuse reflection cavity can enter the second microlens unit 71 along the axis, thereby improving the accuracy of secondary control.

[0074] In some embodiments, the second microlens unit 71 can be in the form of a convex mirror, a plano-convex lens, or an aspherical lens, specifically designed according to the light control requirements. In practical applications, although the light output from the diffuse reflection cavity is adjusted by the diffuse reflection surface, it may still exhibit some angular dispersion, such as ±15 degrees to ±20 degrees. The second microlens unit 71, through curved surface refraction, further converges these dispersed light rays in a direction perpendicular to the driving panel 1, compressing the divergence angle of the final emitted light rays to ±5 degrees to ±15 degrees, significantly improving the directionality of the light. Furthermore, in the diffuse reflection cavity, the light rays reflected by the diffuse reflection surface will generate random scattered light due to the randomness of the reflection angle, and the angular distribution of these light rays still exhibits some dispersion. The second microlens unit 71 can adjust its own curvature to specifically control this type of random scattered light, for example, converting some of the scattered light rays into approximately parallel light, so that the angle of the final emitted light rays is concentrated within a small range of ±15 degrees, thereby significantly improving the directionality and concentration of the light. In the preferred embodiment, the radius of curvature of the second microlens unit 71 is designed to be between 0.5 micrometers and 20 micrometers. This parameter range can be adapted to the light angle characteristics of the diffuse reflection cavity, ensuring that the secondary control effect and the preceding optical structure work together to further optimize the light extraction efficiency and display uniformity of the Micro LED microdisplay chip.

[0075] In some embodiments, the material of the second lens unit includes transparent polymers, inorganic transparent materials, etc., wherein the inorganic transparent materials can be selected from silicon oxide, titanium oxide, aluminum oxide, and various transparent inorganic oxides with a refractive index range of 1.5-2.5; the transparent polymers can be selected from materials similar to plastics, covering various suitable organic materials. Specifically, transparent polymers similar to plastics can be selected from polymethyl methacrylate, polycarbonate, etc., which are low in cost and easy to form at the micro-nano scale through processes such as photolithography and hot stamping, making them suitable for large-scale mass production. Silicon oxide, titanium oxide, aluminum oxide, and the above-mentioned transparent inorganic oxides have higher high-temperature resistance and chemical stability, which can reduce the degradation of optical performance during long-term operation and are suitable for high-reliability scenarios.

[0076] In some embodiments, the bottom diameter of the second microlens unit 71 is slightly larger than the top opening size of the corresponding diffuse reflection aperture 61, thereby ensuring complete coverage of the diffuse reflection aperture 61 and preventing light emitted from the diffuse reflection cavity from leaking out from the edges. In a preferred embodiment, the diameter of the second microlens unit 71 is consistent with the diameter of the corresponding first microlens unit 51, thereby ensuring that the optical structure is aligned with the axis, simplifying the alignment difficulty in the process, and reducing light offset or loss caused by size differences.

[0077] Further, see Figure 1 and Figure 2As shown, both the first microlens unit 51 and the second microlens unit 71 are plano-convex lens structures, and the convex surfaces of both are arranged in a direction away from the driving panel 1, while the planar surfaces are arranged in a direction close to the driving panel 1.

[0078] As can be understood, a plano-convex lens is a lens composed of a flat surface and a convex surface. The convex surface has curved refractive properties, which can deflect incident light in a direction perpendicular to the driving panel 1, thereby converging or collimating diverging light rays. The flat surface reduces additional refraction interference when light is incident, ensuring that light enters the lens at a more stable angle. In practical applications, the flat side of the plano-convex lens facilitates bonding with the underlying structure, and a tight connection can be achieved using materials such as optical adhesives, reducing light reflection loss caused by interface gaps. The convex side faces the light-emitting direction, enabling more efficient angle control of light and avoiding interference with the upper structure.

[0079] In addition, the first microlens unit 51 and the second microlens unit 71 can also be configured as follows: See Figure 3 and Figure 4 As shown, the first microlens unit 51 is a plano-convex lens structure, with its convex surface facing away from the drive panel 1 and its flat surface facing towards the drive panel 1; the second microlens unit 71 is a plano-convex lens structure, with its convex surface facing towards the drive panel 1 and its flat surface facing away from the drive panel 1.

[0080] Understandably, the first microlens unit 51 adopts a plano-convex lens structure, with its convex surface facing away from the driving panel 1. Utilizing the curved refractive properties of the convex surface, it converges light rays scattered by the optical functional layer 4 at relatively dispersed initial angles, such as divergence angles between 30 and 60 degrees, towards the optical axis perpendicular to the driving panel 1, reducing the diffusion of large-angle light rays. Simultaneously, it collimates the stray scattered light in the optical functional layer 4, concentrating the light exit angle within ±15 degrees. Its planar side is attached to the optical functional layer 4. This planar design reduces additional refraction interference during light incidence, ensuring stable light entry into the lens and facilitating tight connection with the underlying structure using materials such as optical adhesive, reducing interface reflection loss. The synergistic effect of the planar and convex surfaces achieves efficient initial focusing and collimation of light. The second microlens unit 71 also has a plano-convex lens structure, but its orientation is opposite to that of the first microlens unit 51. Its convex surface faces the driving panel 1, while its planar surface faces away from the driving panel 1. Since the output light from the diffuse reflection cavity still exhibits a certain degree of angular dispersion, such as ±15 degrees to ±20 degrees, the convex surface of the second microlens unit 71, located near the light-emitting side of the diffuse reflection cavity, can further converge these scattered light rays in a direction perpendicular to the driving panel 1, compressing the divergence angle of the final emitted light to ±5 degrees to ±15 degrees. For the random scattered light generated by the randomness of diffuse reflection in the diffuse reflection cavity, the second microlens unit 71 can convert some of the scattered light into approximately parallel light, concentrating the light angle within a smaller range, such as within ±15 degrees. This greatly improves the directionality and concentration of the light, achieving secondary precise control of the light and optimizing the light emission effect and display uniformity of the Micro LED microdisplay chip.

[0081] Furthermore, based on the relationship between the first color light emitted by LED unit 2 and the wavelength required for target display, the optical functional layer 4 can be configured in the following two ways: If the first color light emitted by LED unit 2 is not the target wavelength light required by the microdisplay, then the multiple optical functional units in the optical functional layer 4 include multiple first wavelength conversion units 41, multiple second wavelength conversion units 42, and multiple third wavelength conversion units 43.

[0082] If the first color light emitted by LED unit 2 is a certain wavelength light required for the micro-display, then the multiple optical functional units in the optical functional layer 4 include multiple first wavelength conversion units 41, multiple second wavelength conversion units 42, and multiple light-transmitting units.

[0083] Wherein: the first wavelength conversion unit 41 fills the corresponding recessed area and is used to convert the first color light into the second color light; the second wavelength conversion unit 42 fills the corresponding recessed area and is used to convert the first color light into the third color light; the third wavelength conversion unit 43 fills the corresponding recessed area and is used to convert the first color light into the fourth color light; the light transmission unit fills the corresponding recessed area and is used to allow the first color light to pass through directly.

[0084] Specifically, when the first color light emitted by LED unit 2 is not the target wavelength light required by the micro-display, the optical functional layer 4 is specifically configured as follows: the optical functional layer 4 includes multiple first wavelength conversion units 41, multiple second wavelength conversion units 42, and multiple third wavelength conversion units 43. Each first wavelength conversion unit 41 is filled with a recessed area of ​​a grid hole 31. After the first color light emitted by LED unit 2 is incident on the first wavelength conversion unit 41, it is converted into second color light. Each second wavelength conversion unit 42 is filled with a recessed area of ​​a grid hole 31 to receive the first color light emitted by LED unit 2 and convert it into third color light. Each third wavelength conversion unit 43 is filled with a recessed area of ​​a grid hole 31 to receive the first color light emitted by LED unit 2 and convert it into fourth color light.

[0085] In some embodiments, for a fence structure 3 having multiple grid holes 31, the filling method of each wavelength conversion unit can be flexibly set: the first wavelength conversion unit 41 fills part of the grid holes 31, the second wavelength conversion unit 42 fills part of the remaining grid holes 31, and the third wavelength conversion unit 43 fills all or part of the remaining grid holes 31. By reasonably allocating the filling position of each wavelength conversion unit, the color combination required for the target display can be achieved.

[0086] In some embodiments, the materials of the first wavelength conversion unit 41, the second wavelength conversion unit 42, and the third wavelength conversion unit 43 are selected to meet the wavelength conversion requirements, including photoresist, quantum dots, and / or phosphors; among them, quantum dot materials have the advantages of high wavelength conversion efficiency and high color purity, while phosphor materials have the characteristics of low cost and good stability. Photoresist can be used as a substrate material, which is convenient for precise filling and shaping through micro-nano processing technology. Single materials or combinations of multiple materials can be selected according to the actual application scenario.

[0087] In some embodiments, to achieve complete color display, the first color light, the second color light, the third color light, and the fourth color light are all different. As a specific example, if the first color light emitted by LED unit 2 is ultraviolet light, which is a non-target display wavelength, then the first wavelength conversion unit 41 can be set as a red light wavelength conversion unit to convert ultraviolet light into red light, which is the second color light; the second wavelength conversion unit 42 can be set as a green light wavelength conversion unit to convert ultraviolet light into green light, which is the third color light; and the third wavelength conversion unit 43 can be set as a blue light wavelength conversion unit to convert ultraviolet light into blue light, which is the fourth color light. Through the synergistic effect of the three wavelength conversion units, the display of red, green, and blue primary colors is achieved, meeting the color requirements of micro-displays.

[0088] Correspondingly, when the first color light emitted by LED unit 2 is a certain wavelength light required for the micro display, in order to avoid redundant settings and reduce process costs, the wavelength conversion unit corresponding to the target wavelength can be omitted. At this time, the recessed area of ​​the grid hole 31 corresponding to the omitted wavelength conversion unit is filled by the light-transmitting unit, so that the first color light can pass through directly and cooperate with the light converted by the other two wavelength conversion units to achieve complete color display.

[0089] The following example further illustrates this: Assume the first wavelength conversion unit 41 is a red light wavelength conversion unit, the second wavelength conversion unit 42 is a green light wavelength conversion unit, and the third wavelength conversion unit 43 is a blue light wavelength conversion unit. If the first color light emitted by the LED unit 2 is blue light, which is the target wavelength light required for the micro-display, then there is no need to set the third wavelength conversion unit 43 corresponding to blue light. At this time, the optical functional layer 4 includes a red light wavelength conversion unit, a green light wavelength conversion unit, and a light-transmitting unit. The red light wavelength conversion unit corresponds to the first wavelength conversion unit 41, the green light wavelength conversion unit corresponds to the second wavelength conversion unit 42, and the light-transmitting unit fills the grid hole 31 originally used to set the third wavelength conversion unit 43. The light is filled with transparent resin material so that the blue light emitted by the LED unit 2 can directly pass through the light-transmitting unit and be emitted out, working together with the red light converted by the red light wavelength conversion unit and the green light converted by the green light wavelength conversion unit to achieve the display of red, green, and blue primary colors.

[0090] Furthermore, in this embodiment, see Figures 1 to 4 As shown, the first color light emitted by LED unit 2 is not the target wavelength light required by the micro-display. Correspondingly, multiple optical functional units in optical functional layer 4 are configured as multiple first wavelength conversion units 41, multiple second wavelength conversion units 42, and multiple third wavelength conversion units 43. Each wavelength conversion unit fills the corresponding recessed area of ​​the grid hole 31 to jointly complete the conversion of the first color light to multiple colors of light required by the target display, so as to meet the color display requirements of the micro-display.

[0091] Furthermore, combining the above text Figures 1 to 4 The device embodiments of this application are described in detail below, in conjunction with... Figures 5 to 17 The present application describes in detail the method embodiments. It should be understood that the description of the method embodiments corresponds to the description of the apparatus embodiments; therefore, any parts not described in detail can be referred to the preceding apparatus embodiments.

[0092] See Figure 5 As shown, the method for manufacturing a Micro LED microdisplay chip includes steps S101 to S107.

[0093] Step S101: Provide a drive panel 1.

[0094] In some embodiments, the driving panel 1 may be a silicon-based CMOS driving board or a TFT driving board.

[0095] In some embodiments, the driving panel 1 includes a substrate, a driving circuit, and electrode contacts. The substrate material can be silicon, glass, sapphire, etc.; the driving circuit forms a transistor array through photolithography, etching, and other processes to achieve independent current control for each LED unit 2; the electrode contacts include a common electrode contact and multiple independent control electrode contacts for electrical connection with the LED unit 2. In practical applications, taking a silicon-based CMOS driving board as an example, CMOS circuits are fabricated on a silicon substrate using semiconductor photolithography to form millions of miniature driving units. Each driving unit corresponds to a control circuit for one LED unit 2, ultimately forming a driving array capable of independently outputting voltage and current signals.

[0096] Step S102: A plurality of LED units 2 are formed on the driving panel 1, each LED unit 2 having a corresponding LED platform and configured to be driven individually by the driving panel 1.

[0097] In some embodiments, firstly, an LED epitaxial layer, such as an N-type GaN, a quantum well light-emitting layer, or a P-type GaN, is grown on a temporary substrate using a metal-organic chemical vapor deposition process to form a multilayer semiconductor structure. Then, the epitaxial layer is patterned into an array of LED units 2 using photolithography and inductively coupled plasma etching, and cut into microchips with micron-sized dimensions. Next, the LED units 2 are transferred from the temporary substrate to the driving panel 1 using laser lift-off technology. Visual positioning combined with a robotic arm transfer alignment ensures that each LED unit 2 is aligned with its corresponding electrode contact on the driving panel 1, achieving electrical connection. Finally, the LED units 2 are welded to the electrode contacts on the driving panel 1 using bonding processes such as thermo-press bonding or ultrasonic bonding to ensure stable conductivity, ultimately forming an array of individually drivable LED units 2. This LED unit 2 array is described in [reference needed]. Figure 6 As shown.

[0098] Step S103: Form a fence structure 3 with multiple grid holes 31. The grid holes 31 correspond one-to-one with the LED units 2 and are arranged around the LED platform. A recessed area is formed between the LED platform and the inner wall of the corresponding grid hole 31.

[0099] In some embodiments, the fence structure 3 may be made of organic resin, black matrix material or inorganic material, so that the fence structure 3 has good insulation, light shielding and etching process compatibility.

[0100] In some embodiments, firstly, a gate material, such as liquid photoresist, is uniformly coated on the surfaces of the driving panel 1 and the LED unit 2. Then, using a photomask matching the array pattern of the LED unit 2, the pattern of the grid holes 31 is transferred to the gate material through ultraviolet exposure, with the exposed area being the location of the grid holes 31. Afterward, the exposed material is developed, and depending on the type of photoresist, the exposed or unexposed area is removed to form the initial grid holes 31. Finally, the initial grid holes 31 are refined using dry etching to ensure that the sidewalls of the grid holes 31 are beveled and that the angle between the beveled surface and the top surface is obtuse. Here, the grid holes 31 correspond one-to-one with the LED units 2, ensuring that the LED mesa is completely located at the center of the grid holes 31, forming a bowl-shaped or trumpet-shaped recessed area around the LED mesa.

[0101] In some embodiments, see Figure 7 As shown, after the fence structure 3 is prepared, high reflectivity metals such as aluminum and silver can be deposited on the surface of the fence structure 3 by sputtering or vapor deposition to form a reflective layer 8.

[0102] Step S104: Fill the recessed area with optical functional material to form optical functional layer 4.

[0103] In some embodiments, based on the matching relationship between the first color light emitted by the LED unit 2 and the target display light color, the optical functional layer 4 can be filled with wavelength conversion material or light-transmitting material into the recessed areas of the corresponding grid holes 31, specifically including the following two implementation methods: filling a first portion of the multiple recessed areas with a first wavelength conversion material to form multiple first wavelength conversion units 41, the first wavelength conversion units 41 being used to convert the first color light emitted by the LED unit 2 into second color light; filling a second portion of the multiple recessed areas with a second wavelength conversion material to form multiple second wavelength conversion units 42, the second wavelength conversion units 42 being used to convert the first color light emitted by the LED unit 2 into third color light; selectively filling the remaining portion of the multiple recessed areas with a third wavelength conversion material or light-transmitting material to form multiple third wavelength conversion units 43 or multiple light-transmitting units; wherein, if a third wavelength conversion material is filled, the third wavelength conversion unit 43 is used to convert the first color light emitted by the LED unit 2 into fourth color light; if a light-transmitting material is filled, the light-transmitting unit is used to allow the first color light emitted by the LED unit 2 to pass through directly. Specifically, when the light emitted by LED unit 2 is a non-target display wavelength such as ultraviolet light, the remaining area is filled with a third wavelength conversion material to form multiple third wavelength conversion units 43. Each wavelength conversion unit converts the first color light emitted by LED unit 2 into target display color light such as red, green, and blue light, thereby achieving RGB full-color display. When the light emitted by LED unit 2 is itself a target display wavelength, such as blue light, the remaining area is filled with a light-transmitting material to form a light-transmitting unit, allowing the first color light to pass through directly. The remaining pixel positions, namely the first part area and the second part area, are filled with red light wavelength conversion material and green light wavelength conversion material, respectively, to form corresponding wavelength conversion units, jointly achieving RGB three-primary-color display.

[0104] In some embodiments, the optical functional material includes one or more combinations of photoresist system, quantum dot material, phosphor material or transparent resin material: the wavelength conversion unit uses photoresist doped with quantum dots or phosphor, which has both wavelength conversion function and patterning performance; the light transmission unit uses highly transparent photoresist or transparent resin to ensure low light loss transmission.

[0105] In some embodiments, different optical functional materials are mixed with photoresist before filling and then ultrasonically dispersed to form a uniform slurry.

[0106] In some embodiments, during the filling process, when applying red light paste, the position of the grid hole 31 corresponding to the red light pixel is defined by a photomask, and ultraviolet exposure cures the red light paste to form a red light wavelength conversion unit. When applying green light paste, the above steps are repeated, using green light paste and a corresponding photomask to fill and cure the grid hole 31 corresponding to the green light pixel to form a green light wavelength conversion unit. Subsequently, if the LED emits ultraviolet light, the above steps are repeated, using blue light paste and a corresponding photomask to fill and cure the grid hole 31 corresponding to the blue light pixel to form a blue light wavelength conversion unit. If the LED emits blue light, a transparent resin material can be used to fill and cure the grid hole 31 corresponding to the blue light pixel. Here, the red light wavelength conversion unit corresponds to the aforementioned first wavelength conversion unit 41, the green light wavelength conversion unit corresponds to the aforementioned second wavelength conversion unit 42, and the blue light wavelength conversion unit corresponds to the aforementioned third wavelength conversion unit 43.

[0107] In some embodiments, after filling, the surface may be chemically and mechanically polished to make the top surface of the optical functional layer 4 flush with the top surface of the fence structure 3. (See also: Optical functional layer 4) Figure 8 As shown.

[0108] Step S105: A first microlens array 5 is prepared on the side of the optical functional layer 4 away from the driving panel 1. The first microlens array 5 includes a plurality of first microlens units 51 corresponding one-to-one with a plurality of grid holes 31. Each first microlens unit 51 covers the corresponding grid hole 31 and is configured to focus and / or collimate the light after it has been acted upon by the optical functional layer 4.

[0109] In some embodiments, the first microlens array 5 is fabricated using a hot-pressing method. First, a microlens master is fabricated on a silicon wafer using electron beam lithography. Then, a lens material is coated onto the surface of the optical functional layer 4. The microlens master is aligned with the array of grid holes 31, the lens material is heated above its glass transition temperature, and pressure is applied to fill the pattern of the microlens master with the lens material. Finally, the microlens master is cooled and removed, yielding a first microlens unit 51 corresponding to each of the grid holes 31. (See attached image for details.) Figure 9 As shown.

[0110] Step S106: A diffuse reflection structure 6 is formed on the side of the fence structure 3 away from the drive panel 1. The diffuse reflection structure 6 has multiple diffuse reflection holes 61, which correspond one-to-one with the grid holes 31, and the hole walls of the diffuse reflection holes 61 are formed as diffuse reflection surfaces. The diffuse reflection holes 61 and the corresponding first microlens units 51 enclose a diffuse reflection cavity, which is configured to diffusely reflect and control the large-angle light emitted from the first microlens units 51.

[0111] In some embodiments, see Figures 10 to 12As shown, firstly, photoresist is spin-coated on the side of the fence structure 3 and the optical functional layer 4 away from the driving panel 1 to form a mask layer; then, a portion of the photoresist in the mask layer relative to the grid hole 31 is removed to form an inverted trapezoidal photomask, which is correspondingly set with the grid hole 31; then, a metal layer is formed on the sidewall and top surface of the inverted trapezoidal photomask, the metal layer including a horizontal metal layer and a sidewall metal layer; finally, the horizontal metal layer is removed and the sidewall metal layer is retained, the sidewall metal layer being the hole wall of the diffuse reflection hole 61.

[0112] Step S107: A second microlens array 7 is prepared on the side of the diffuse reflection structure 6 away from the driving panel 1. The second microlens array 7 includes a plurality of second microlens units 71 corresponding one-to-one with a plurality of diffuse reflection holes 61. Each second microlens unit 71 covers the corresponding diffuse reflection hole 61 and is configured to perform secondary focusing and / or collimation on the light emitted from the diffuse reflection cavity.

[0113] In some embodiments, see Figures 13 to 15 As shown, when the fabricated second microlens unit 71 is a plano-convex lens structure, with its convex surface facing away from the driving panel 1 and its flat surface facing towards the driving panel 1, the fabrication process of the second microlens array 7 is as follows: First, a precursor layer 711 is formed on the side of the sidewall metal layer away from the driving panel 1; then, through holes are opened in the precursor layer 711 at positions corresponding to the first microlens unit 51, and the through holes are precisely aligned with the corresponding diffuse reflection holes 61; then, the photoresist remaining below the through holes is removed, so that the through holes and diffuse reflection holes 61 are connected, together forming a diffuse reflection cavity with an inverted trapezoidal cross-section; next, the through holes are sealed with lens material to form a complete lens material layer 712; finally, the lens material layer 712 and the precursor layer 711 are integrally fabricated into the second microlens array 7 through processes such as photolithography, hot stamping, or curing.

[0114] It should be noted that the second microlens array 7 is composed of a precursor layer 711 and a lens material layer 712. The precursor layer 711 is attached to the side of the diffuse reflection structure 6 away from the driving panel 1, serving as a support and positioning element. The lens material layer 712 covers the side of the precursor layer 711 away from the diffuse reflection structure 6, forming the core optical structure of the second microlens unit 71. Each second microlens unit 71 in the second microlens array 7 is formed by the corresponding area of ​​the precursor layer 711 and the corresponding area of ​​the lens material layer 712, ensuring that each second microlens unit 71 can accurately cover the corresponding diffuse reflection aperture 61. The precursor layer 711 can be made of inorganic transparent materials such as silicon oxide or aluminum oxide, which have good support and optical compatibility. The lens material layer 712 can be made of the same transparent polymer or inorganic transparent material as the first microlens unit 51, ensuring refractive index matching during light propagation, reducing interface reflection loss, and ensuring secondary focusing and collimation effects.

[0115] In some embodiments, see Figure 16 and Figure 17 As shown, when the fabricated second microlens unit 71 is a plano-convex lens structure, with its convex surface facing towards the driving panel 1 and its flat surface facing away from the driving panel 1, the fabrication process of the second microlens array 7 is as follows: First, remove some of the residual photoresist inside the diffuse reflection hole 61 to form a concave surface on the inner wall of the diffuse reflection hole 61; then, fabricate a precursor layer 711 on the side of the concave surface away from the driving panel 1; next, open through holes in the precursor layer 711 at positions corresponding to the first microlens unit 51, with the through holes precisely corresponding to the positions of the corresponding diffuse reflection holes 61; then, remove the residual photoresist below the through holes to connect the through holes with the diffuse reflection holes 61, forming a diffuse reflection cavity with an inverted trapezoidal cross-section; next, seal the through holes with lens material to form a complete lens material layer 712; finally, fabricate the second microlens array 7 by means of photolithography, hot stamping, or curing processes, integrating the lens material layer 712 and the precursor layer 711 into a single unit.

[0116] By applying the method for manufacturing Micro LED microdisplay chips provided in the embodiments of this application, it is clear that the driving panel 1 can drive each LED unit 2 individually, so that each pixel can be precisely controlled, which helps to improve the resolution and contrast of the display, making the display picture more delicate and vivid, and meeting the requirements of high-quality display.

[0117] The method for manufacturing a Micro LED microdisplay chip provided in this application embodiment uses a first microlens array 5 to initially focus and collimate the light, a diffuse reflection cavity to control the diffuse reflection of large-angle light, and a second microlens array 7 to perform secondary focusing and collimation. This multi-stage collaboration effectively improves the problem of a wide angular distribution of the light emitted from the LED unit 2, reduces high brightness at large angles, and makes the light more concentrated and evenly distributed, thus improving the clarity and brightness uniformity of the displayed image. Specifically, see... Figure 18 As shown, Figure 18 This is a comparison curve of the light emission angle and brightness of the Micro LED microdisplay chip (with lens) and the traditional lensless structure (without lens) of this application. Figure 18 As can be seen, traditional lensless solutions have a wide light angle distribution and maintain high brightness at large angles. However, after adopting the structure of the first microlens array 5 and the second microlens array 7 of this application, the brightness of the light in the central region at small angles is significantly improved, while the brightness of the light at large angles is significantly reduced. This effectively suppresses the problem of high brightness at large angles, realizes the focusing and collimation of light, improves the light utilization rate, reduces crosstalk between pixels, and thus improves the brightness, clarity and contrast of the Micro LED microdisplay chip.

[0118] By applying the method for manufacturing Micro LED microdisplay chips provided in the embodiments of this application, the optical functional layer 4 is filled in the recessed area, which can perform wavelength conversion on the first color light emitted by the LED unit 2 and convert it into light of other different colors, thus helping to achieve full-color display. At the same time, the optical functional layer 4 may also include a light-transmitting unit, allowing the first color light emitted by the LED unit 2 to pass through directly, further enriching the light control methods, flexibly adapting to various display needs, effectively expanding the application range of Micro LED microdisplay chips, and improving their adaptability and practicality.

[0119] By applying the method for manufacturing Micro LED microdisplay chips provided in this application embodiment, the reflective layer 8 disposed on the surface of the gate structure 3 can effectively block light leakage from the sidewalls of the LED unit 2, avoiding ineffective light loss. Simultaneously, the reflective layer 8 can reflect the light emitted by the LED unit 2, converging and collimating the reflected light and the light directly emitted by the LED unit 2, thereby improving the wavelength conversion efficiency of the optical functional layer 4 and ensuring the effectiveness of light utilization. Furthermore, the diffuse reflection cavity formed by the diffuse reflection structure 6 and the first microlens unit 51 can adjust large-angle light that might otherwise be wasted to an effective emission angle through diffuse reflection, allowing this portion of light to re-participate in the overall light output, significantly reducing light loss and further improving the optical performance of the chip.

[0120] By applying the method for manufacturing Micro LED microdisplay chips provided in the embodiments of this application, the top surface of the optical functional layer 4 is flush with or lower than the top surface of the fence structure 3. This not only effectively prevents light crosstalk between adjacent LED units 2 and ensures independent propagation of light, but also ensures the flatness and stability of the chip structure, which is beneficial to the subsequent production process and indirectly improves the effectiveness of light utilization.

[0121] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0122] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A Micro LED microdisplay chip, characterized in that, include: Driver panel; Multiple LED units are arranged on the driving panel, each LED unit has a corresponding LED platform and can be driven individually by the driving panel; A first microlens array is located on the side of the LED unit away from the driving panel. The first microlens array includes a plurality of first microlens units corresponding one-to-one with the plurality of LED units. The first microlens units are used to focus and / or collimate the light emitted by the LED units. The second microlens array is located on the side of the first microlens array away from the LED unit. The second microlens array includes a plurality of second microlens units that correspond one-to-one with the plurality of first microlens units. The second microlens units are used to focus and / or collimate the light emitted from the first microlens units.

2. The Micro LED microdisplay chip according to claim 1, characterized in that, Both the first microlens unit and the second microlens unit are plano-convex lens structures, and the convex surfaces of both are arranged in a direction away from the driving panel, while the flat surfaces are arranged in a direction close to the driving panel. Alternatively, the first microlens unit is a plano-convex lens structure, with its convex surface facing away from the driving panel and its flat surface facing towards the driving panel; the second microlens unit is a plano-convex lens structure, with its convex surface facing towards the driving panel and its flat surface facing away from the driving panel.

3. The Micro LED microdisplay chip according to claim 1, characterized in that, Also includes: A diffuse reflection structure is located between the first microlens array and the second microlens array. The diffuse reflection structure has multiple diffuse reflection holes, each corresponding to an LED unit. The diffuse reflection holes and the corresponding first microlens units enclose a diffuse reflection cavity, which is used to diffusely control the large-angle light emitted from the first microlens units.

4. The Micro LED microdisplay chip according to claim 3, characterized in that, The second microlens array is formed by fabricating a precursor layer and a lens material layer together; The precursor layer is located on the side of the diffuse reflection structure away from the drive panel, and the lens material layer covers the side of the precursor layer away from the diffuse reflection structure; Each of the second microlens units in the second microlens array is composed of corresponding regions of the precursor layer and the lens material layer.

5. The Micro LED microdisplay chip according to claim 3, characterized in that, The hole wall of the diffuse reflection hole is a diffuse reflection surface, and the roughness of the diffuse reflection surface is 5 nanometers to 20 nanometers.

6. The Micro LED microdisplay chip according to claim 3, characterized in that, Also includes: A fence structure is located between the LED unit and the first microlens array. The fence structure has multiple grid holes, each of which corresponds one-to-one with the diffuse reflection hole and the LED unit. The grid holes are arranged around the LED platform of the corresponding LED unit, and a recessed area is formed between the LED platform and the inner wall of the corresponding grid hole. The recessed area is used to fill the optical functional layer.

7. The Micro LED microdisplay chip according to claim 6, characterized in that, The height of the diffuse reflection cavity is the quotient of the radius of the corresponding optical functional layer divided by tan30°.

8. The Micro LED microdisplay chip according to claim 6, characterized in that, The first microlens unit and the second microlens unit both have a radius of curvature of 0.5 micrometers to 20 micrometers; the bottom diameter of the first microlens unit and the second microlens unit is greater than 20% of the diameter of the corresponding optical functional layer; the diameter of the optical functional layer is 1 micrometer to 10.5 micrometers.

9. The Micro LED microdisplay chip according to claim 6, characterized in that, The LED unit is used to emit light of a first color; the optical functional layer includes at least: Multiple first wavelength conversion units, each first wavelength conversion unit filling the corresponding recessed region, the first wavelength conversion unit being used to convert the first color light into the second color light; Multiple second wavelength conversion units are provided, each filling a corresponding recessed region, and each second wavelength conversion unit is used to convert the first color light into a third color light.

10. The Micro LED microdisplay chip according to claim 9, characterized in that, The optical functional layer also includes: Multiple third wavelength conversion units are provided, which fill the corresponding recessed areas, and are used to convert the first color light into a fourth color light. Alternatively, multiple light-transmitting units, wherein the light-transmitting units fill the corresponding recessed areas, and the light-transmitting units are used to allow the first color light to pass through directly.

11. The Micro LED microdisplay chip according to claim 1, characterized in that, The drive panel includes: The first electrode contact serves as a common electrode contact and is connected to the first polarity terminal of all the LED units. Multiple second electrode contacts, which serve as independent control electrode contacts, are respectively connected to the second polarity terminals of the multiple LED units.

12. A method for manufacturing a Micro LED microdisplay chip, characterized in that, include: Provide a driver panel; Multiple LED units are formed on the driving panel, each LED unit having a corresponding LED platform and configured to be driven individually by the driving panel; A fence structure with multiple grid holes is formed, wherein each grid hole corresponds to one of the LED units and is arranged around the LED platform, and a recessed area is formed between the LED platform and the inner wall of the corresponding grid hole; An optical functional material is filled into the recessed area to form an optical functional layer; A first microlens array is fabricated on the side of the optical functional layer away from the driving panel. The first microlens array includes a plurality of first microlens units corresponding one-to-one with the plurality of grid holes. Each first microlens unit covers the corresponding grid hole and is configured to converge and / or collimate the light after it has passed through the optical functional layer. A diffuse reflection structure is formed on the side of the fence structure away from the drive panel. The diffuse reflection structure has multiple diffuse reflection holes, each corresponding to a grid hole, and the hole wall of the diffuse reflection hole is formed as a diffuse reflection surface. The diffuse reflection holes and the corresponding first microlens units enclose a diffuse reflection cavity, which is configured to diffusely control the large-angle light emitted from the first microlens units. A second microlens array is fabricated on the side of the diffuse reflection structure away from the driving panel. The second microlens array includes a plurality of second microlens units corresponding one-to-one with the plurality of diffuse reflection holes. Each second microlens unit covers the corresponding diffuse reflection hole and is configured to focus and / or collimate the light emitted from the diffuse reflection cavity.

13. The method according to claim 12, characterized in that, Before filling the recessed area with optical functional material to form an optical functional layer, the method further includes: A reflective layer is formed on the surface of the fence structure.

14. The method according to claim 12, characterized in that, The process of filling the recessed area with optical functional material to form an optical functional layer includes: A first wavelength conversion material is filled in a first portion of the plurality of recessed regions to form a plurality of first wavelength conversion units, wherein the first wavelength conversion units are used to convert the first color light emitted by the LED unit into a second color light. A second portion of the recessed regions is filled with a second wavelength conversion material to form a plurality of second wavelength conversion units, wherein the second wavelength conversion units are used to convert the first color light emitted by the LED unit into a third color light; In the remaining areas of the plurality of recessed regions, a third wavelength conversion material or a light-transmitting material is selectively filled to form a plurality of third wavelength conversion units or a plurality of light-transmitting units; wherein, if the third wavelength conversion material is filled, the third wavelength conversion unit is used to convert the first color light emitted by the LED unit into a fourth color light; if the light-transmitting material is filled, the light-transmitting unit is used to allow the first color light emitted by the LED unit to pass through directly. The top surfaces of the first wavelength conversion unit, the second wavelength conversion unit, and the third wavelength conversion unit, or the top surfaces of the first wavelength conversion unit, the second wavelength conversion unit, and the light-transmitting unit, are controlled to be flush with or lower than the top surface of the fence structure.

15. The method according to claim 12, characterized in that, The formation of a diffuse reflection structure on the side of the fence structure away from the drive panel includes: Photoresist is spin-coated on the side of the fence structure and the optical functional layer away from the driving panel to form a mask layer; A portion of the photoresist in the mask layer corresponding to the grid holes is removed to form an inverted trapezoidal photomask, which is disposed corresponding to the grid holes; A metal layer is formed on the sidewalls and top surface of the inverted trapezoidal photomask, the metal layer including a horizontal metal layer and a sidewall metal layer; Remove the horizontal metal layer and retain the sidewall metal layer, which is the hole wall of the diffuse reflection hole.

16. The method according to claim 15, characterized in that, The fabrication of a second microlens array on the side of the diffuse reflection structure away from the driving panel includes: A precursor layer is formed on the side of the sidewall metal layer away from the drive panel; A through-hole is formed in the precursor layer at a position corresponding to the first microlens unit, and the through-hole corresponds to the position of the diffuse reflection hole. Remove the photoresist below the via to form the diffuse reflection cavity, the cross-sectional shape of which is an inverted trapezoid; The through-hole is sealed to form a lens material layer; The lens material layer and the precursor layer are fabricated into a second microlens array.

17. The method according to claim 15, characterized in that, The fabrication of a second microlens array on the side of the diffuse reflection structure away from the driving panel includes: Remove a portion of the photoresist from the diffuse reflection hole to form a concave surface; A precursor layer is formed on the side of the concave surface opposite to the drive panel; A through-hole is formed in the precursor layer at a position corresponding to the first microlens unit, and the through-hole corresponds to the position of the diffuse reflection hole. Remove the photoresist below the via to form the diffuse reflection cavity, the cross-sectional shape of which is an inverted trapezoid; The through-hole is sealed to form a lens material layer; The lens material layer and the precursor layer are fabricated into a second microlens array.

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