Micro LED micro-display chip and preparation method thereof

Abstract

The invention relates to the technical field of display chips, and provides a Micro LED micro display chip and a preparation method thereof, the micro display chip comprises a driving substrate and a light emitting structure arranged on the driving substrate; the light-emitting structure comprises a plurality of LED units arranged on the driving substrate at intervals, each LED unit can be independently driven by the driving substrate, and the LED units are provided with a plurality of LED table tops in one-to-one correspondence; the first fence structure is provided with a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED table boards, and the first fence structure is higher than the plurality of LED units; and the optical layer is arranged on the first fence structure, and the LED table board and the optical layer form a cavity area at the corresponding first grid holes. The cavity area is formed through a simple process, heat of the LED unit is reduced to be transmitted to the light conversion structure above, the service life of the micro-display chip is prolonged, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of display chip technology, and specifically to a Micro LED micro display chip and a method for preparing the same. Background Art

[0002] Micro LED, also known as micro light-emitting diode, is an array of micron-level LED light-emitting units integrated on an active addressing drive substrate to achieve individual control and lighting, thereby outputting display images. Full-color micro display has a wide range of applications, especially near-eye display (including AR, VR, etc.).

[0003] In the traditional full-color micro-display format, a light conversion structure is directly arranged on the light-emitting structure. Since the heat of the LED unit is directly transmitted to the light conversion structure, the aging and failure of the light conversion structure are accelerated, so that the life of the full-color micro-display device is limited to a certain extent.

[0004] In order to limit the heat generated by the LED unit from being transferred to the light conversion structure, Chinese patent document CN119050126A discloses a display device and a method for forming the same. A heat-insulating structure is provided on the planarization layer, and the heat-insulating structure includes an overhead unit. In order to form the overhead unit, a sacrificial layer is formed on the planarization layer, a preset number of holes are formed on the sacrificial layer, the holes penetrate the sacrificial layer to expose the surface of the planarization layer, support feet are formed in the holes, and an overhead layer is formed on the sacrificial layer. By removing the sacrificial layer, the overhead layer is suspended on the support feet. In order to form a heat-insulating cavity inside the overhead unit, a heat-conducting layer is sealed between adjacent overhead units to ensure that the side of the overhead unit is blocked. Chinese patent document CN119050126A forms a complex overhead unit on the planarization layer. The overall thickness of the micro-display device structure is large, and the preparation process is complex, which is not conducive to the development of chip products towards small size and low cost.

[0005] Chinese patent document CN119050236A discloses a MicroLED micro display chip. A plurality of through holes are provided on the first transmissive reflective layer, and each group of through holes is circumferentially arranged around the edge of the corresponding grid hole. The through holes penetrate the first transmissive reflective layer and extend to the inside of the grid hole, so that the corrosive liquid can flow into the grid hole through the through holes, so as to corrode and hollow out the sacrificial layer in the grid hole through the corrosive liquid. By filling the through holes with a heat-conducting metal unit, a cavity of a central control structure can be formed between the first transmissive reflective layer and the LED unit. In order to form a cavity, Chinese patent CN119050236A not only needs to break the integrity of the first transmissive reflective layer so that the first transmissive reflective layer has a plurality of through holes, but also needs to use a heat-conducting metal unit to seal the through holes to form a cavity. The above-mentioned complex process greatly increases the production cost. Since the above-mentioned complex process has extremely high precision requirements, it results in a low yield. Summary of the invention

[0006] To solve the above problems, the present application provides a Micro LED micro display chip and a preparation method thereof, which forms a cavity structure on the LED unit through a simple process, reduces the heat conduction of the LED unit to the light conversion structure, improves the service life of the micro display chip, and reduces manufacturing costs.

[0007] This application adopts the following technical solutions: In a first aspect, a Micro LED micro display chip is provided, comprising: a driving substrate and a light emitting structure disposed on the driving substrate; The light emitting structure comprises: a plurality of LED units, a first fence structure and an optical layer; A plurality of LED units are arranged on the driving substrate at intervals, and each LED unit can be driven individually by the driving substrate, and the plurality of LED units have a plurality of LED tables corresponding to each other. The first fence structure has a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED table tops, and the first fence structure is higher than the plurality of LED units; The optical layer is arranged on the first fence structure, and the LED table and the optical layer form a cavity area at the corresponding first grid holes.

[0008] Optionally, the first fence structure includes: a first light-blocking substrate and a first light-reflecting layer disposed on the surface of the first light-blocking substrate; The first light-blocking substrate has a plurality of first grid holes; The first light reflecting layer is at least arranged on the side wall of the first grid hole.

[0009] Optionally, the optical layer includes: a transparent transition layer disposed on the first fence structure and a transmissive reflective layer disposed on the transparent transition layer; The optical layer is used to transmit light from a plurality of LED units.

[0010] Optionally, the transparent transition layer has a via hole at a position corresponding to each first grid hole.

[0011] Optionally, the transmissive reflective layer is a distributed Bragg reflective layer.

[0012] Optionally, the material of the transparent transition layer is a transparent inorganic oxide.

[0013] Optionally, the diameter of the via hole is less than 0.5 μm.

[0014] Optionally, the micro display chip further includes: a light conversion structure disposed on the optical layer; The light conversion structure includes: a second fence structure and a plurality of light conversion units; The second fence structure has a plurality of second grid holes, and the plurality of second grid holes correspond one to one with the plurality of first grid holes; The plurality of light conversion units are respectively disposed in the plurality of second grid holes.

[0015] Optionally, the second fence structure includes: a second light-blocking substrate and a second light-reflecting layer disposed on the surface of the second light-blocking substrate; The second light-blocking substrate has a plurality of second grid holes; The second light reflecting layer is at least arranged on the side walls of the second grid holes.

[0016] Optionally, the plurality of light conversion units include at least: a first light conversion unit and a second light conversion unit; The first light conversion unit converts the light passing through the optical layer into a first color light; The second light conversion unit converts the light passing through the optical layer into second color light.

[0017] Optionally, the plurality of light conversion units further include: a transparent unit; The transparent unit transmits the light passing through the optical layer.

[0018] Optionally, the plurality of light conversion units further include: a third light conversion unit; The third light conversion unit converts the light passing through the optical layer into third color light.

[0019] In a second aspect, a method for preparing a Micro LED micro display chip is provided, comprising: Providing a driving substrate, and forming a light emitting structure on the driving substrate; Wherein, forming a light emitting structure on a driving substrate comprises: A plurality of LED units are formed; wherein the plurality of LED units are arranged on a driving substrate at intervals from each other, and each LED unit can be driven individually by the driving substrate, and the plurality of LED units have a plurality of LED tables corresponding to each other; Forming a first fence structure; wherein the first fence structure has a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED table tops, and the first fence structure is higher than the plurality of LED units; Forming an optical layer; wherein the optical layer is formed on the first fence structure, and the LED table and the optical layer form a cavity area at the corresponding first grid holes; Wherein, forming an optical layer comprises: Using filler to flatten the first fence structure; forming a transparent transition material layer on the planarized first fence structure; Etching the transparent transition material layer at a position corresponding to each first grid hole to form a via hole, thereby obtaining a transparent transition layer; Removing fillers from each LED table and the transparent transition layer at the corresponding first grid holes through the via holes; A transmissive reflective layer is formed on the transparent transition layer.

[0020] Optionally, forming a first fence structure includes: forming a first light-blocking matrix material layer on the plurality of LED units; Etching the first light-blocking matrix material layer to form a plurality of first grid holes surrounding the plurality of LED mesas to obtain a first light-blocking matrix; forming a first light-reflecting material layer on the plurality of LED tables and the first light-blocking substrate; The first light reflecting material layer is etched to form a first light reflecting layer at least on the sidewalls of the first grid holes.

[0021] Optionally, the method further includes: forming a light conversion structure; The light conversion structure is formed, comprising: forming a second fence structure on the optical layer; wherein the second fence structure has a plurality of second grid holes, and the plurality of second grid holes correspond one to one to the plurality of first grid holes; A plurality of light conversion units are formed in the plurality of second grid holes.

[0022] Optionally, forming a second fence structure on the optical layer includes: forming a second light-blocking matrix material layer on the optical layer; Etching the second light-blocking matrix material layer to form a plurality of second grid holes corresponding to the first grid holes one by one, thereby obtaining a second light-blocking matrix; forming a second light reflecting material layer on the optical layer and the second light blocking substrate; The second light reflecting material layer is etched to form a second light reflecting layer at least on the sidewalls of the second grid holes.

[0023] Optionally, a plurality of light conversion units are formed in the plurality of second grid holes, comprising: Filling a plurality of second grid holes with a light conversion material; wherein the light conversion material at least includes: a first light conversion material and a second light conversion material; Filling a first light conversion material in part of the second grid holes to form a first light conversion unit to convert the light passing through the optical layer into a first color light; A second light conversion material is filled in a portion of the second grid holes to form a second light conversion unit to convert the light passing through the optical layer into a second color light.

[0024] At least one of the above technical solutions adopted in this application can achieve the following beneficial effects: The chip provided by the present application includes: a driving substrate and a light-emitting structure arranged on the driving substrate; the light-emitting structure includes: a plurality of LED units arranged on the driving substrate at intervals from each other, each LED unit can be driven individually by the driving substrate, and the plurality of LED units have a plurality of LED tables corresponding to each other; a first fence structure, the first fence structure has a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED tables, the first fence structure is higher than the plurality of LED units; an optical layer arranged on the first fence structure, the LED tables and the optical layer form a cavity area at the corresponding first grid holes.

[0025] The Micro LED micro display chip proposed in the present application has an LED table and an optical layer forming a cavity area at the corresponding first grid hole. The air in the cavity area has extremely low thermal conductivity (in a closed state, the thermal conductivity of the air is only 0.024 W / m·K), which reduces the heat conduction of the LED unit to the light conversion structure above, and effectively improves the service life of the Micro LED micro display chip.

[0026] The Micro LED micro display chip proposed in the present application can tightly enclose a cavity area through the first grid holes and the optical layer. The manufacturing process is simple and does not require excessively complex precision processing, and the product yield is high.

[0027] The Micro LED micro display chip proposed in this application has lower production costs and is suitable for large-scale mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 A schematic diagram showing the structure of a Micro LED micro display chip according to an embodiment of the present application is shown; Figure 2 A schematic diagram showing the structure of a Micro LED micro display chip according to another embodiment of the present application is shown; Figure 3 A schematic diagram showing a process of manufacturing a Micro LED micro display chip according to an embodiment of the present application; Figure 4 A schematic diagram showing a structure after forming a plurality of LED units according to an embodiment of the present application is shown; Figure 5 A schematic diagram showing a structure after forming a first light-blocking matrix material layer according to an embodiment of the present application; Figure 6A schematic structural diagram after obtaining a first light-shielding substrate according to an embodiment of the present application is shown; Figure 7 A schematic diagram showing a structure after forming a first light-reflecting material layer according to an embodiment of the present application; Figure 8 A schematic diagram showing a first light reflecting layer after being formed according to an embodiment of the present application; Fig. 9 A schematic diagram of a structure after planarization according to an embodiment of the present application is shown; Fig.10 A schematic diagram showing a structure after a transparent transition material layer is formed according to an embodiment of the present application; Fig.11 A schematic diagram of the structure after obtaining a transparent transition layer according to an embodiment of the present application is shown; Fig.12 A schematic diagram showing a structure after the filler is removed according to an embodiment of the present application; Fig.13 A schematic diagram showing a structure after forming a transmissive reflective layer according to an embodiment of the present application; Fig.14 A schematic diagram showing a structure after a second fence structure is formed according to an embodiment of the present application; Fig.15 A schematic diagram showing a structure after forming a plurality of light conversion units according to an embodiment of the present application; Fig.16 Another structural schematic diagram after forming a plurality of light conversion units according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present application will be described in more detail below. However, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to enable the scope of the present application to be fully communicated to those skilled in the art.

[0030] The disclosure of the present invention provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described in the present invention. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0031] Generally, the terms may be understood at least in part based on the usage of the above invention. For example, the term "one or more" used in the present invention depends at least in part on the above invention, and may be used to describe any component, structure or feature in a singular form, or may be used to describe a combination of components, structures or features in a plural form. Similarly, terms such as "one", "an" or "the" may also be understood at least in part based on the above invention as conveying singular usage or conveying plural usage. In addition, the term "based on..." may be understood as not necessarily intended to convey a set of exclusive factors, but may alternatively, at least in part depending on the context, allow for the presence of additional factors that do not necessarily have to be explicitly described.

[0032] It should be noted that, in the description of the present application, the meanings of the terms "on", "over", "above", "over", etc. should be interpreted in the broadest way, meaning that the description containing these terms is interpreted as "the component can be set on another component in direct contact, or there can be intermediate components or layers between the components."

[0033] For ease of description, the present application may also use spatially relative terms such as "under", "beneath", "below", "under", "upper", "lower", etc. to describe the relationship of one component to another component shown in the drawings. In addition to the orientations described in the drawings, the spatially relative terms are also intended to cover different orientations of the device in use or operation. The device can be oriented in other ways, and the spatially relative descriptions used in the present application can be interpreted accordingly.

[0034] Figure 1 The schematic diagram of the structure of the Micro LED micro display chip proposed in one embodiment of the present application is shown. Figure 1 The horizontal direction may correspond to the cross-sectional extension direction of the Micro LED micro display chip, and the vertical direction may correspond to the ideal light beam propagation direction of the Micro LED micro display chip.

[0035] Reference Figure 1 The micro display chip of this embodiment may include: a driving substrate 1 and a light emitting structure 2 disposed on the driving substrate 1 .

[0036] The light emitting structure 2 includes: a plurality of LED units 21, a first fence structure 22 and an optical layer 23. The plurality of LED units 21 are arranged on the driving substrate 1 at intervals, and each LED unit 21 can be driven individually by the driving substrate 1, and the plurality of LED units 21 have a plurality of LED countertops corresponding to each other. The first fence structure 22 has a plurality of first grid holes, and the plurality of first grid holes respectively surround the plurality of LED countertops, and the first fence structure 22 is higher than the plurality of LED units 21. The optical layer 23 is arranged on the first fence structure 22, and the LED countertops and the optical layer 23 form a cavity area at the corresponding first grid holes.

[0037] The driving substrate 1 may include a substrate 11, a driving circuit, and a plurality of contacts connected to the driving circuit. The driving substrate 1 may be provided with a circuit layer including a silicon-based CMOS (Complementary Metal Oxide Semiconductor) backplane, a TFT glass substrate, or a thin film field effect transistor, etc., to form a driving circuit. The material of the substrate 11 may include semiconductor materials such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, cobalt phosphide, etc.; it may also include non-conductive materials such as glass, plastic, sapphire wafers, etc. The driving substrate 1 may be bonded to each LED unit 21 through contacts, and each LED unit 21 may be integrated above the corresponding contact.

[0038] A plurality of LED units 21 may be arranged on the driving substrate 1 in a regular or irregular manner as pixels of a micro display chip. The driving substrate 1 may refer to a control panel of the plurality of LED units 21. The driving substrate 1 generates a driving signal based on an image to be displayed and applies it to the plurality of LED units 21, so that each LED unit 21 independently releases a light beam in response to the driving signal.

[0039] The LED unit 21 may be a micro light emitting diode or a micro organic light emitting diode. The micro light emitting diode is formed based on inorganic semiconductor materials, for example, the inorganic semiconductor material may be gallium nitride, aluminum gallium nitrogen, gallium arsenide, aluminum gallium indium phosphide, etc. The micro organic light emitting diode is formed based on organic materials, for example, the organic material may be a small molecule, a polymer, a phosphorescent material, etc.

[0040] Each LED unit 21 has an LED table, and the LED table may be a trapezoidal structure. That is, the side wall of the LED table may be an inclined surface, and the angle between the side wall of the LED table and the top surface of the LED table may be an obtuse angle, thereby improving the focusing effect of the LED unit 21. Of course, the LED table may also be a columnar structure, in which case the angle between the side wall of the LED table and the top surface of the LED table is a right angle.

[0041] The Micro LED micro display device can be a common cathode structure, or a common anode structure, or each can be independent.

[0042] In some optional embodiments, each LED unit 21 may include a first doped semiconductor layer 211, a light emitting layer 212, and a second doped semiconductor layer 213 that are stacked. The passivation layer 214 covers the light emitting surface and side surfaces of each LED unit 21 and has an opening on the light emitting surface of each LED unit 21, and the passivation layer 214 exposes the contacts of the driving substrate 1. Each LED unit 21 also includes a first electrode 216 and a second electrode 217, and a bonding layer 215 may be included between the first electrode 216 and the first doped semiconductor layer 211. The first doped semiconductor layer 211 is connected to the first contact 13 corresponding to the driving substrate 1 through the bonding layer 215 and the first electrode 216, and the second doped semiconductor layer 213 is connected to the second contact 12 corresponding to the driving substrate 1 through the second electrode 217.

[0043] When the first electrode 216 of each LED unit 21 is a common electrode, the Micro LED micro display device is a common anode structure; when the second electrode 217 of each LED unit 21 is a common electrode, the Micro LED micro display device is a common cathode structure. Figure 1 The case shown is a common anode configuration.

[0044] The first doped semiconductor layer 211 may be a p-type GaN or InGaN layer formed by doping or ion implantation, etc., and the first doped semiconductor layer 211 may be a multi-layer structure. The second doped semiconductor layer 213 may be an n-type GaN or InGaN layer formed by doping or ion implantation, etc., and the second doped semiconductor layer 213 may also be a multi-layer structure. The light-emitting layer 212 is a layer that outputs light of a specific wavelength based on the recombination of holes provided by the first doped semiconductor layer 211 and electrons provided from the second doped semiconductor layer 213. The light-emitting layer 212 may have a single quantum well structure or a multiple quantum well (MQW) structure, and may also alternately stack well layers and barrier layers.

[0045] The passivation layer 214 material may include inorganic materials or organic materials. The inorganic material may include, but is not limited to, any one or a combination of silicon dioxide, aluminum oxide, zirconium dioxide, titanium dioxide, silicon nitride, and hafnium oxide; the organic material includes any one or a combination of black matrix photoresist, color filter photoresist, polyimide, barrier glue (BANK), overcoat glue, near-ultraviolet negative photoresist, and styrene.

[0046] The materials of the first electrode 216 and the second electrode 217 may be metal materials or metal alloy materials, including indium tin oxide, chromium, platinum, gold, aluminum, germanium, tin, indium, copper or titanium.

[0047] A first fence structure 22 is provided around the plurality of LED tables. The first fence structure 22 has a plurality of first grid holes corresponding to the LED tables one by one. That is, according to the arrangement of the plurality of LED units 21, the plurality of first grid holes can be arranged in a regular or irregular manner. In order to improve the uniformity of light emission of each LED unit 21, each LED unit 21 can be arranged at the center of the corresponding first grid hole.

[0048] The side wall of the first grid hole may be an inclined surface, that is, the angle between the side wall of the first grid hole and the top surface of the first fence structure 22 is an obtuse angle. Figure 1 As shown in the direction away from the driving substrate 1, the cross-sectional size of the first grid hole can gradually increase. Generally, the cross section can be a circular cross section or a square cross section, and of course, the cross section can also be an irregular cross section. The structure of the first grid hole can be a bowl-shaped structure or a trumpet-shaped structure, so that the emitted light of the LED unit 21 can be collimated. When the side wall of the LED table is set as an inclined surface and the side wall of the first grid hole is also set as an inclined surface, the light can be reflected multiple times on the inclined surfaces of the two, thereby improving the luminous brightness of the LED unit 21.

[0049] The height of the first fence structure 22 is higher than the plurality of LED units 21. In other words, the height of the top surface of the first fence structure 22 is higher than the height of the top surface of each LED unit 21.

[0050] In some optional embodiments, the first fence structure 22 includes: a first light-blocking substrate 221 and a first light-reflecting layer 222 disposed on the surface of the first light-blocking substrate 221. The first light-blocking substrate 221 has a plurality of first grid holes. The first light-reflecting layer 222 is at least disposed on the sidewalls of the first grid holes.

[0051] The first fence structure 22 can be formed by using a first light-blocking matrix material. The first light-blocking matrix material is provided with a first grid hole at a position corresponding to each LED unit 21, and a first light-reflecting layer 222 is provided at least on the side wall of the first grid hole. The first light-reflecting layer 222 can also be provided on the top surface of the first light-blocking matrix 221.

[0052] The material of the first light-blocking substrate 221 may include, but is not limited to, organic resin, organic black matrix photoresist, color filter photoresist or polyimide, etc. The material of the first light-reflecting layer 222 may include, but is not limited to, organic material or inorganic material. The organic material may be a highly reflective organic coating, and the inorganic material may be a metal material such as aluminum, copper, silver, etc.

[0053] The first reflective layer 222 in the first fence structure 22 can effectively prevent light leakage from the sidewall of each LED unit 21, thereby effectively preventing light crosstalk between adjacent LED units 21. At the same time, the first fence structure 22 also plays a heat conduction role, preventing the heat of the LED material from being concentrated and transferred to the fluorescent material.

[0054] In some optional implementations, the plurality of LED units 21 may be covered with an etching stop layer to prevent etching from damaging the plurality of LED mesas.

[0055] The etching stop layer may be a continuous film layer structure, located between the first fence structure 22 and the plurality of LED units 21. The etching stop layer may transmit the light emitted by the plurality of LED units 21, so the etching stop layer should have sufficient transparency. Generally, the material of the etching stop layer may include but is not limited to silicon dioxide, silicon nitride or aluminum oxide.

[0056] An optical layer 23 is provided on the first fence structure 22. For each LED unit 21, its LED table, optical layer 23 and corresponding first grid hole are covered to form a closed cavity area. The air in the cavity area has extremely low thermal conductivity. In a closed state, the thermal conductivity of air is only 0.024W / m·K. Therefore, through the closed cavity area, the heat conduction of the LED material to the fluorescent material above is reduced, effectively improving the service life of the Micro LED micro display chip.

[0057] In some optional embodiments, the optical layer 23 includes: a transparent transition layer 231 disposed on the first fence structure 22 and a transmissive reflective layer 232 disposed on the transparent transition layer 231. The optical layer 23 is used to transmit light from the plurality of LED units 21.

[0058] In order to form a closed cavity area between the optical layer 23 and the LED table at the corresponding first fence hole, it is necessary to use filler 233 to flatten the first fence structure 22 before forming the optical layer 23. During the process of forming the optical layer 23, the filler 233 is removed to form a cavity structure.

[0059] Therefore, after the first fence structure 22 is flattened, a transparent transition layer 231 is formed on the flattened first fence structure 22, and a via hole is formed by etching the transparent transition layer 231 at a position corresponding to each first grid hole, and a transmissive reflective layer 232 is formed on the transparent transition layer 231 after removing the filler 233 through the via hole, thereby realizing a closed cavity structure. That is, the transparent transition layer 231 has a via hole at a position corresponding to each first grid hole.

[0060] The material of the transparent transition layer 231 may be a transparent inorganic oxide material, such as silicon dioxide, aluminum oxide, etc. Meanwhile, the thickness of the transparent transition layer 231 may be as thin as possible.

[0061] In order to take into account the functional requirements of removing the filler 233 and supporting the transmissive reflective layer 232, the diameter of the via hole is not greater than 0.5 μm. The via hole can be opened at the center position of each first fence hole of the transparent transition layer 231.

[0062] The transmissive reflective layer 232 may be a distributed Bragg reflector (DBR) layer. The distributed Bragg reflective layer may be composed of a plurality of materials with different refractive indices that are alternately stacked. The material used for the transmissive reflective layer 232 is generally a semiconductor material, such as but not limited to silicon, indium nitride, gallium nitride, aluminum gallium nitride, and nickel iron phosphide. These semiconductor materials have different refractive indices, and by stacking them together according to a specific design, reflection of light of a specific wavelength can be achieved. By adjusting the number of layers and composition of the material, transmission of light of different wavelengths can be achieved.

[0063] The function of the optical layer 23 includes transmitting the light emitted by the plurality of LED units 21. When the micro display chip further includes a light conversion structure 3 disposed on the optical layer 23, the function of the optical layer 23 also includes reflecting the light converted by the light conversion structure 3.

[0064] Figure 2 A schematic diagram of the structure of a Micro LED micro display chip proposed in another embodiment of the present application is shown.

[0065] Reference Figure 2 The micro display chip of this embodiment, based on the micro display chip proposed in the previous embodiment, further includes: a light conversion structure 3 arranged on the optical layer 23. The light conversion structure 3 includes: a second fence structure 31 and a plurality of light conversion units 32. The second fence structure 31 has a plurality of second grid holes, and the plurality of second grid holes correspond to the plurality of first grid holes one by one. The plurality of light conversion units 32 are respectively arranged in the plurality of second grid holes.

[0066] The second fence structure 31 has a plurality of second grid holes corresponding to the first grid holes one by one, that is, according to the arrangement of the plurality of first grid holes, the plurality of second grid holes can be arranged in a regular or irregular manner.

[0067] The side wall of the second grid hole may be an inclined surface, that is, the angle between the side wall of the second grid hole and the top surface of the second fence structure 31 is an obtuse angle. Figure 2As shown, in the direction away from the driving substrate 1, the cross-sectional size of the second grid hole can gradually increase. Generally, the cross section can be a circular cross section or a square cross section, and of course, the cross section can also be an irregular cross section. The structure of the second grid hole can be a bowl-shaped structure or a trumpet-shaped structure.

[0068] In some optional embodiments, the second fence structure 31 includes: a second light shielding substrate 311 and a second light reflecting layer 312 disposed on the surface of the second light shielding substrate 311. The second light shielding substrate 311 has a plurality of second grid holes. The second light reflecting layer 312 is at least disposed on the sidewalls of the second grid holes.

[0069] The second fence structure 31 can be formed by using a second light-blocking matrix material. The second light-blocking matrix material is provided with a second grid hole at a position corresponding to each first grid hole, and a second light-reflecting layer 312 is provided at least on the side wall of the second grid hole. The second light-reflecting layer 312 can also be provided on the top surface of the second light-blocking matrix 311.

[0070] The material of the second light-blocking substrate 311 may include, but is not limited to, organic resin, organic black matrix photoresist, color filter photoresist or polyimide, etc. The material of the second light-reflecting layer 312 may include, but is not limited to, organic material or inorganic material. The organic material may be a highly reflective organic coating, and the inorganic material may be a metal material such as aluminum, copper, silver, etc.

[0071] The second light reflecting layer 312 in the second fence structure 31 can effectively prevent the light entering the light conversion unit 32 from affecting the light of the adjacent light conversion unit 32 , thereby reducing the crosstalk between them and improving the display effect.

[0072] A plurality of light conversion units 32 are respectively arranged in the plurality of second grid holes, so that each light conversion unit 32 is correspondingly arranged on one LED unit 21. Each light conversion unit 32 at least fills a part or all of the corresponding second grid hole.

[0073] In some optional embodiments, the plurality of light conversion units 32 at least include: a first light conversion unit 321 and a second light conversion unit 322. The first light conversion unit 321 converts light passing through the optical layer 23 into first color light; the second light conversion unit 322 converts light passing through the optical layer 23 into second color light.

[0074] Among the plurality of light conversion units 32, some light conversion units 32 are first light conversion units 321, and some light conversion units 32 are second light conversion units 322. That is, the first light conversion units 321 and the second light conversion units 322 are respectively disposed in different second grid holes.

[0075] The material of the light conversion unit 32 includes photoresist and wavelength conversion particles. The wavelength conversion particles can be, but are not limited to, quantum dots and / or phosphors. Photoresists include, but are not limited to, overcoat glue, SU8 (near-ultraviolet negative photoresist), benzocyclobutene (BCB), etc., and can also be silicon dioxide, aluminum oxide, silicon nitride, etc. The phosphor can be yttrium aluminum garnet, cerium phosphor, (oxy) nitride phosphor, silicate phosphor, and Mn 4+ activated fluoride phosphors, etc. The quantum dots may include one or more combinations of CdSe, CdS, CdZnSe, CdZnS, CdZnSeS, ZnSeS, ZnSe, CuInS, CuInSe, InP, InZnP, and perovskite quantum dots, etc.

[0076] The light emitted by the LED unit 21 enters the first light conversion unit 321 after passing through the optical layer 23, and is converted into the first color light in the first light conversion unit 321. The first color light may be red light, and in this case, the first light conversion unit 321 uses a red wavelength conversion material. The light emitted by the LED unit 21 enters the second light conversion unit 322 after passing through the optical layer 23, and is converted into the second color light in the second light conversion unit 322. The second color light may be green light, and in this case, the second light conversion unit 322 uses a green wavelength conversion material.

[0077] In some optional implementations, the plurality of light conversion units 32 further include: a transparent unit 324 ; the transparent unit 324 transmits the light passing through the optical layer 23 .

[0078] In some cases, the light emitted by the LED unit 21 is blue light. In this case, the transparent unit 324 only needs to transmit the blue light emitted by the LED unit 21. Therefore, the transparent unit 324 is disposed in the second grid hole where the first light conversion unit 321 and the second light conversion unit 322 are not disposed, so as to directly transmit the blue light emitted by the LED unit 21.

[0079] In some optional embodiments, the plurality of light conversion units 32 further include: a third light conversion unit 323 ; the third light conversion unit 323 converts the light passing through the optical layer 23 into a third color light.

[0080] In some cases, the light emitted by the LED unit 21 is not blue light. In this case, the light emitted by the LED unit 21 enters the third light conversion unit 323 after passing through the optical layer 23, and is converted into a third color light in the third light conversion unit 323. The third color light may be blue light, and in this case, the third light conversion unit 323 uses a blue wavelength conversion material.

[0081] The first color light, the second color light and the third color light are all different. The first color light, the second color light and the third color light can also be set to other color lights according to actual needs. By setting multiple light conversion units 32, full-color display of the MicroLED micro display chip is achieved.

[0082] Figure 3 The schematic diagram of the process of preparing a Micro LED micro display chip according to one embodiment of the present application is shown. Figure 3 The preparation method proposed in this application comprises the following steps: Step S1, providing a driving substrate 1; Step S2 , forming a light emitting structure 2 on the driving substrate 1 .

[0083] Wherein, step S2, forming a light emitting structure 2 on the driving substrate 1, comprises: Step S21, forming a plurality of LED units 21; wherein the plurality of LED units 21 are arranged on the driving substrate 1 at intervals, and each LED unit 21 can be driven individually by the driving substrate 1, and the plurality of LED units 21 have a plurality of LED tables corresponding to each other; Step S22, forming a first fence structure 22; wherein the first fence structure 22 has a plurality of first grid holes, the plurality of first grid holes respectively surround a plurality of LED tables, and the first fence structure 22 is higher than the plurality of LED units 21; Step S23, forming an optical layer 23; wherein the optical layer 23 is formed on the first fence structure 22, and the LED table and the optical layer 23 form a cavity area at the corresponding first grid hole; wherein the formation of the optical layer 23 includes: using a filler 233 to flatten the first fence structure 22; forming a transparent transition material layer 231a on the flattened first fence structure 22; etching the transparent transition material layer 231a at a position corresponding to each first grid hole to form a via hole to obtain a transparent transition layer 231; removing the filler 233 at the corresponding first grid hole of each LED table and the transparent transition layer 231 through the via hole; and forming a transmissive reflective layer 232 on the transparent transition layer 231.

[0084] Figures 4 to 16 Schematic diagram showing different stages in the preparation process of Micro LED micro display chip. Figures 4 to 16 , the method of preparing Micro LED micro display chip is introduced in detail.

[0085] Figure 4 FIG. 2 shows a schematic diagram of a structure after forming a plurality of LED units 21. In some embodiments of the present application, see Figure 4, forming a plurality of LED units 21, including: forming an LED epitaxial layer on a driving substrate 1; etching the LED epitaxial layer according to a MESA pattern designed by a patterned mask to form an intermediate; forming a passivation layer 214 on the side wall of the intermediate; forming a second electrode 217 on the passivation layer 214, the second electrode 217 connecting the top surface of the LED epitaxial layer and the second contact 12 of the driving substrate 1, thereby forming a plurality of LED units 21.

[0086] A substrate is provided, an LED epitaxial layer is grown on the substrate, and a first bonding layer is formed on the LED epitaxial layer. The first bonding layer can be used to bond the LED epitaxial layer on the substrate to a driving substrate 1 proposed later.

[0087] A driving substrate 1 is provided. The driving substrate 1 may be provided with a circuit layer including a silicon-based CMOS backplane, a TFT glass substrate or a thin film field effect transistor to form a driving circuit. The driving substrate 1 also includes a plurality of contacts connected to the driving circuit. The plurality of contacts include a first contact 13 and a second contact 12. A first electrode 216 and a second bonding layer are formed on the driving substrate 1. The first electrode 216 is connected to the first contact 13. The second bonding layer can be used to bond the driving substrate 1 to the LED epitaxial layer on the substrate.

[0088] The LED epitaxial layer, the first bonding layer, the first electrode 216 and the second bonding layer can be formed by deposition.

[0089] The bonding layer 215 is formed by metal bonding the first bonding layer and the second bonding layer, so that the LED epitaxial layer is bonded to the driving substrate 1 .

[0090] The substrate is peeled off from the LED epitaxial layer. The substrate peeling method includes but is not limited to laser peeling, dry etching, wet etching, mechanical polishing, etc.

[0091] The LED epitaxial layer is thinned by dry etching, wet etching or mechanical polishing.

[0092] According to the MESA pattern designed by the patterned mask, the bonded LED epitaxial layer is etched, and then the bonding layer 215 is etched to form a plurality of intermediates. Each intermediate includes a first doped semiconductor layer 211, a light emitting layer 212 and a second doped semiconductor layer 213. The etching includes a dry method or a wet method.

[0093] A passivation layer 214 is deposited on the side surface of the intermediate body, and a second electrode 217 is deposited on the passivation layer 214 so that the second electrode 217 connects the second doped semiconductor layer 213 and the second contact 12 , thereby forming a plurality of LED units 21 .

[0094] Figures 5 to 8Schematic diagram of the structure of forming the first fence structure 22. In some embodiments of the present application, see Figures 5 to 8 , forming a first fence structure 22, including: forming a first light-blocking matrix material layer 221a on the multiple LED units 21; etching the first light-blocking matrix material layer 221a to form a plurality of first grid holes surrounding the multiple LED countertops to obtain a first light-blocking matrix 221; forming a first reflective material layer 222a on the multiple LED countertops and the first light-blocking matrix 221; etching the first reflective material layer 222a to form a first reflective layer 222 at least on the side wall of the first grid hole.

[0095] A first light-blocking matrix material layer 221a may be formed on the plurality of LED units 21. Figure 5 shown.

[0096] The first light-blocking matrix material layer 221a is etched to form a first light-blocking matrix 221 having a plurality of first grid holes. The plurality of first grid holes surround a plurality of LED tables respectively, and a depression is formed between the LED tables and the corresponding first grid holes. Figure 6 shown.

[0097] A first light-reflecting material layer 222a is formed on the plurality of LED tables and the first light-blocking substrate 221. The first light-reflecting material layer 222a may be deposited by atomic layer deposition (ALD), chemical vapor deposition (CVD), evaporation, sputtering, etc. Figure 7 shown.

[0098] The first reflective material layer 222a on the multiple LED tables is etched to form the first reflective layer 222 on the side walls of the first grid holes and the top surface of the first light blocking substrate 221. Etching can be done by dry etching, including but not limited to ion beam etching (IBE), inductively coupled plasma etching (ICP), etc. By dry etching, the first reflective material layer 222a can be etched on the entire surface after being deposited, so that the first reflective material on the multiple LED tables is etched cleanly. At the same time, during the etching process, the first reflective material layer 222a will have a plasma re-deposition effect, resulting in the first reflective material layer 222a on the side walls of the first grid holes being thickened, thereby enhancing the reflective effect and strengthening the stability of the first fence structure 22. Figure 8 shown.

[0099] In some embodiments of the present application, before forming the first fence structure 22 , the preparation method may further include: forming an etching barrier layer; wherein the etching barrier layer covers the plurality of LED units 21 to prevent damage to the plurality of LED tables when etching the first fence structure 22 .

[0100] In some embodiments of the present application, before etching the first reflective material layer 222a on the multiple LED tables, the preparation method may also include: forming a sacrificial coating on the first reflective material layer 222a; removing the sacrificial coating exposed on the first grid holes; etching the first reflective material layer 222a on the multiple LED tables; and removing the remaining sacrificial coating.

[0101] Figures 9 to 13 Schematic diagram of the structure of forming the optical layer 23. In some embodiments of the present application, see Figures 9 to 13 , forming an optical layer 23, including: using a filler 233 to flatten the first fence structure 22; forming a transparent transition material layer 231a on the flattened first fence structure 22; etching the transparent transition material layer 231a at a position corresponding to each first grid hole to form a via hole to obtain a transparent transition layer 231; removing the filler 233 at the corresponding first grid hole of each LED table and the transparent transition layer 231 through the via hole; forming a transmissive reflective layer 232 on the transparent transition layer 231.

[0102] The first grid holes of the first fence structure 22 are filled with fillers 233. The filling height is the top of the grid network of the first fence structure 22. The fillers 233 can be made of organic resin materials. Fig. 9 shown.

[0103] A transparent transition material layer 231a is formed on the planarized first fence structure 22. The material of the transparent transition material layer 231a can be a transparent inorganic oxide material, such as silicon dioxide, aluminum oxide, etc. At the same time, the thickness of the transparent transition material layer 231a can be as thin as possible. The transparent transition material layer 231a can be deposited by atomic layer deposition (ALD), chemical vapor deposition (CVD), evaporation, sputtering, etc. Fig.10 shown.

[0104] The transparent transition material layer 231a is etched to form a via hole at the position corresponding to each first grid hole, thereby obtaining the transparent transition layer 231. The diameter of the via hole is not greater than 0.5 μm. The method for forming the via hole may be, but is not limited to, high-precision photolithography, photoresist reflow, pattern step transfer, etc. Fig.11 shown.

[0105] The filler 233 at the corresponding first grid hole of each LED table and the transparent transition layer 231 is removed through the via hole. The method for removing the filler 233 can be: using O2 plasma to non-directionally glue and isotropically drain the filler 233 to form a cavity area. Fig.12 shown.

[0106] A transmissive reflective layer 232 is formed on the transparent transition layer 231. The transmissive reflective layer 232 may be deposited by reactive ion deposition, evaporation, sputtering, etc. The transmissive reflective layer 232 may be a distributed Bragg reflective layer. Fig.13 shown.

[0107] In some embodiments of the present application, the step of etching the transparent transition material layer 231a at the position corresponding to each first grid hole to form a via hole may include: depositing a mask on the transparent transition material layer 231a and spin-coating a photoresist; using a photolithography machine to expose and then develop to obtain a mask pattern; dry-etching the mask to form an opening corresponding to each first grid hole; reactive ion etching the transparent transition material layer 231a to form a via hole; and removing the photoresist and the mask.

[0108] Figures 14 to 16 A schematic diagram of a structure for forming a light conversion structure is shown. In some embodiments of the present application, see Figures 14 to 16 The preparation method further includes: forming a light conversion structure 3. The light conversion structure 3 is formed, including: forming a second fence structure 31 on the optical layer 23; wherein the second fence structure 31 has a plurality of second grid holes, and the plurality of second grid holes correspond to the plurality of first grid holes one by one; and forming a plurality of light conversion units 32 in the plurality of second grid holes.

[0109] A second fence structure 31 may be formed on the optical layer 23. Fig.14 shown.

[0110] In some embodiments of the present application, a second fence structure 31 is formed on the optical layer 23, including: forming a second light-blocking matrix material layer on the optical layer 23; etching the second light-blocking matrix material layer to form a plurality of second grid holes corresponding one-to-one to the first grid holes to obtain a second light-blocking matrix 311; forming a second reflective material layer on the optical layer 23 and the second light-blocking matrix 311; etching the second reflective material layer to form a second reflective layer 312 at least on the side walls of the second grid holes.

[0111] It is particularly noted that the method for forming the second light-blocking matrix material layer is similar to the method for forming the first light-blocking matrix material layer 221a, the method for forming the second light matrix is ​​similar to the method for forming the first light-blocking matrix 221, the method for forming the second light-reflecting material layer is similar to the method for forming the first light-reflecting material layer 222a, and the method for forming the second light-reflecting layer 312 is similar to the method for forming the first light-reflecting layer 222. Please refer to the method for forming the first fence structure 22 proposed above, which will not be repeated here.

[0112] A plurality of light conversion units 32 are formed in the plurality of second grid holes. Fig.15 and Fig.16 shown.

[0113] In some embodiments of the present application, a plurality of light conversion units 32 are formed in a plurality of second grid holes, including: filling a light conversion material in the plurality of second grid holes; wherein the light conversion material includes at least: a first light conversion material, a second light conversion material and a transparent material; filling a portion of the second grid holes with the first light conversion material to form a first light conversion unit 321 to convert light passing through the optical layer 23 into light of a first color; filling a portion of the second grid holes with the second light conversion material to form a second light conversion unit 322 to convert light passing through the optical layer 23 into light of a second color; and filling a portion of the second grid holes with a transparent material to form a transparent unit 324 to transmit light passing through the optical layer 23.

[0114] In the case where the LED unit 21 emits blue light, Fig.15 As shown, the first light conversion material can be formed in the second grid holes and filled with the first light conversion material by spin coating and drying.

[0115] The area where the first light conversion unit 321 is to be formed is irradiated with light. The area where the first light conversion unit 321 is to be formed can be exposed by shielding other areas with a mask layer.

[0116] The mask layer is removed, and the first light conversion material is developed with a developer. Since only the area of ​​the first light conversion unit 321 is light-cured, the remaining part will be removed by the developer, thereby forming the first light conversion unit 321 in part of the second grid holes, converting the blue light emitted by the corresponding LED unit into red light.

[0117] A second light conversion unit 322 may be formed in the second grid holes of other parts of the second fence structure 31 to convert the blue light emitted by the corresponding LED unit into green light; a transparent unit 324 may be formed in the second grid holes of other parts of the second fence structure 31 to directly transmit the blue light emitted by the corresponding LED unit. That is, different light conversion units 32 are formed in different second grid holes. Thus, a full-color Micro LED micro display chip is realized.

[0118] In some embodiments of the present application, a plurality of light conversion units 32 are formed in a plurality of second grid holes, including: filling a light conversion material in the plurality of second grid holes; wherein the light conversion material includes at least: a first light conversion material, a second light conversion material and a third light conversion material; filling a portion of the second grid holes with the first light conversion material to form a first light conversion unit 321 to convert light passing through the optical layer 23 into light of a first color; filling a portion of the second grid holes with the second light conversion material to form a second light conversion unit 322 to convert light passing through the optical layer 23 into light of a second color; and filling a portion of the second grid holes with the third light conversion material to form a third light conversion unit 323 to convert light passing through the optical layer 23 into light of a third color.

[0119] In the case where the LED unit 21 does not emit blue light, Fig.16 As shown, the first light conversion material can be formed in the second grid holes and filled with the first light conversion material by spin coating and drying.

[0120] The area where the first light conversion unit 321 is to be formed is irradiated with light. The area where the first light conversion unit 321 is to be formed can be exposed by shielding other areas with a mask layer.

[0121] The mask layer is removed, and the first light conversion material is developed with a developer. Since only the area of ​​the first light conversion unit 321 is light-cured, the remaining part will be removed by the developer, thereby forming the first light conversion unit 321 in part of the second grid holes, converting the blue light emitted by the corresponding LED unit into red light.

[0122] A second light conversion unit 322 may be formed in the second grid holes of other parts of the second fence structure 31 to convert the blue light emitted by the corresponding LED unit into green light; a third light conversion unit 323 may be formed in the second grid holes of other parts of the second fence structure 31 to convert the blue light emitted by the corresponding LED unit into blue light. That is, different light conversion units 32 are formed in different second grid holes. Thus, a full-color Micro LED micro display chip is realized.

[0123] The preparation method proposed in the present application uses a filler for flattening and then deposits a transparent transition material layer, etches a via hole at the position of each first grid hole in the transparent transition material layer, drains the filler through the via hole, and then deposits a transmissive reflective layer to seal the cavity area.

[0124] In the preparation method proposed in the present application, the via hole only needs to correspond to the position of the first grid hole, so the position accuracy requirement for etching the via hole is not high.

[0125] The preparation method proposed in the present application can achieve the sealing of the cavity area by simply depositing the transmissive reflective layer after draining the filler through the via hole, without the need for precise alignment or complex filling.

[0126] Compared with the existing technology, such as Chinese patent documents CN119050126A or CN119050236A, the preparation method proposed in this application can seal the cavity area through a simple process, and then limit the heat transfer of the LED unit to the light conversion structure through the cavity area. It not only improves the service life of the micro display chip, but also reduces the manufacturing cost, improves the product yield, and is suitable for large-scale mass production.

[0127] The above is only a specific implementation of the present application. Under the above teachings of the present application, those skilled in the art can make other improvements or modifications based on the above embodiments. Those skilled in the art should understand that the above specific description is only to better explain the purpose of the present application, and the protection scope of the present application shall be based on the protection scope of the claims.

[0128] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

Claims

1. A Micro LED micro display chip, characterized in that: The micro display chip comprises: a driving substrate and a light emitting structure arranged on the driving substrate; The light emitting structure comprises: a plurality of LED units, a first fence structure and an optical layer; The plurality of LED units are arranged on the driving substrate at intervals, and each of the LED units can be driven individually by the driving substrate, and the plurality of LED units have a plurality of LED tables corresponding to each other; The first fence structure has a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED table tops, and the first fence structure is higher than the plurality of LED units; The optical layer is disposed on the first fence structure, and the LED table and the optical layer form a cavity area at the corresponding first grid holes.

2. The Micro LED micro display chip according to claim 1, characterized in that: The first fence structure comprises: a first light-blocking substrate and a first light-reflecting layer arranged on the surface of the first light-blocking substrate; The first light-shielding substrate has a plurality of the first grid holes; The first light reflecting layer is at least arranged on the side wall of the first grid hole.

3. The Micro LED micro display chip according to claim 1, characterized in that: The optical layer comprises: a transparent transition layer disposed on the first fence structure and a transmissive reflective layer disposed on the transparent transition layer; The optical layer is used to transmit light from the plurality of LED units.

4. The Micro LED micro display chip according to claim 3, characterized in that: The transparent transition layer has a via hole at a position corresponding to each of the first grid holes.

5. The Micro LED micro display chip according to claim 3, characterized in that: The transmissive reflective layer is a distributed Bragg reflective layer.

6. The Micro LED micro display chip according to claim 3, characterized in that: The material of the transparent transition layer is transparent inorganic oxide.

7. The Micro LED micro display chip according to claim 4, characterized in that: The diameter of the via hole is less than 0.5 μm.

8. The Micro LED micro display chip according to claim 1, characterized in that: The micro display chip further includes: a light conversion structure disposed on the optical layer; The light conversion structure comprises: a second fence structure and a plurality of light conversion units; The second fence structure has a plurality of second grid holes, and the plurality of second grid holes correspond one to one with the plurality of first grid holes; The plurality of light conversion units are respectively disposed in the plurality of second grid holes.

9. The Micro LED micro display chip according to claim 8, characterized in that: The second fence structure comprises: a second light-blocking substrate and a second light-reflecting layer arranged on the surface of the second light-blocking substrate; The second light-shielding substrate has a plurality of the second grid holes; The second light reflecting layer is at least arranged on the side wall of the second grid hole.

10. The Micro LED micro display chip according to claim 8, characterized in that: The plurality of light conversion units at least include: a first light conversion unit and a second light conversion unit; The first light conversion unit converts the light passing through the optical layer into a first color light; The second light conversion unit converts the light passing through the optical layer into second color light.

11. The Micro LED micro display chip according to claim 10, characterized in that: The plurality of light conversion units further include: a transparent unit; The transparent unit transmits light passing through the optical layer.

12. The Micro LED micro display chip according to claim 10, characterized in that: The plurality of light conversion units further include: a third light conversion unit; The third light conversion unit converts the light passing through the optical layer into a third color light.

13. A method for preparing a Micro LED micro display chip, characterized in that: The preparation method comprises the following steps: Providing a driving substrate, and forming a light emitting structure on the driving substrate; Wherein, forming a light emitting structure on the driving substrate comprises: Forming a plurality of LED units; wherein the plurality of LED units are arranged on the driving substrate at intervals from each other, and each of the LED units can be driven individually by the driving substrate, and the plurality of LED units have a plurality of LED tables corresponding to each other; Forming a first fence structure; wherein the first fence structure has a plurality of first grid holes, the plurality of first grid holes respectively surround the plurality of LED table tops, and the first fence structure is higher than the plurality of LED units; forming an optical layer; wherein the optical layer is formed on the first fence structure, and the LED table and the optical layer form a cavity area at the corresponding first grid holes; Wherein, the forming of the optical layer comprises: Using filler to flatten the first fence structure; forming a transparent transition material layer on the planarized first fence structure; Etching the transparent transition material layer at a position corresponding to each of the first grid holes to form a via hole, thereby obtaining a transparent transition layer; Removing the filler from each of the LED tables and the transparent transition layer at the corresponding first grid holes through the via holes; A transmissive reflective layer is formed on the transparent transition layer.

14. The method for preparing a Micro LED micro display chip according to claim 13, characterized in that: The forming of the first fence structure comprises: forming a first light-blocking matrix material layer on the plurality of LED units; Etching the first light-blocking matrix material layer to form a plurality of the first grid holes surrounding the plurality of LED tabletops to obtain the first light-blocking matrix; forming a first light-reflecting material layer on the plurality of LED tables and the first light-blocking substrate; The first light reflecting material layer is etched to form a first light reflecting layer at least on the sidewalls of the first grid holes.

15. The method for preparing a Micro LED micro display chip according to claim 13, characterized in that: The preparation method further comprises: forming a light conversion structure; The light conversion structure is formed, comprising: forming a second fence structure on the optical layer; wherein the second fence structure has a plurality of second grid holes, and the plurality of second grid holes correspond one to one to the plurality of first grid holes; A plurality of light conversion units are formed in the plurality of second grid holes.

16. The method for preparing a Micro LED micro display chip according to claim 15, characterized in that: The forming of a second fence structure on the optical layer comprises: forming a second light-blocking matrix material layer on the optical layer; Etching the second light-shielding matrix material layer to form a plurality of second grid holes corresponding to the first grid holes one by one, thereby obtaining the second light-shielding matrix; forming a second light reflecting material layer on the optical layer and the second light blocking substrate; The second light reflecting material layer is etched to form a second light reflecting layer at least on the sidewalls of the second grid holes.

17. The method for preparing a Micro LED micro display chip according to claim 15, characterized in that: The forming of a plurality of light conversion units in a plurality of the second grid holes comprises: Filling a plurality of the second grid holes with a light conversion material; wherein the light conversion material at least includes: a first light conversion material and a second light conversion material; Filling the first light conversion material in part of the second grid holes to form a first light conversion unit to convert the light passing through the optical layer into a first color light; The second light conversion material is filled in a portion of the second grid holes to form a second light conversion unit to convert the light passing through the optical layer into a second color light.

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