Micro-LED microdisplay chip and its fabrication method

Abstract

This application relates to the field of micro-display chip technology, proposing a Micro-LED micro-display chip and its fabrication method. The chip includes: a driving substrate, a light-emitting structure, a lower grid structure, and an upper grid structure. The light-emitting structure includes multiple LED mesas arranged at intervals on the driving substrate and driven independently. The lower grid structure includes a metal grid substrate, which forms multiple grid holes surrounding each LED mesas. The height of the metal grid substrate is not lower than that of each LED mesas. The upper grid structure includes multiple three-dimensional metal rings, with each three-dimensional metal ring independently corresponding to a portion of the LED mesas disposed on the metal grid substrate to prevent light crosstalk between corresponding LED mesas inside and outside the three-dimensional metal rings. By simplifying the arrangement of the three-dimensional metal rings, light crosstalk is avoided, improving the utilization rate of the light-emitting area and enhancing the chip's brightness, reliability, and lifespan.

Description

Technical Field

[0001] This application relates to the field of micro-display chip technology, specifically to a Micro-LED micro-display chip and its fabrication method. Background Technology

[0002] Micro-LED microdisplay chips, also known as miniature light-emitting diodes, integrate arrayed micron-sized LED light-emitting units onto an active addressable driver substrate to achieve individual control and illumination, thereby outputting displayed images. Full-color microdisplays have a wide range of applications, especially near-eye displays (including AR, VR, etc.).

[0003] In quantum dot and / or phosphor pink conversion-type Micro-LED microdisplay chips, to achieve effective isolation between different colors and avoid light crosstalk, traditional structures typically employ a design where a three-dimensional metal ring is wrapped around the color conversion material and supported by a resin support material. However, traditional structures have the following drawbacks: Each LED platform requires an independent three-dimensional metal ring, which severely compresses the effective light-emitting area within the pixel region. In addition, the resin support material also occupies a certain amount of space in the pixel area, resulting in insufficient utilization of the light-emitting area and reduced chip brightness.

[0004] In full-color micro-displays where the color conversion structure is directly integrated into the light-emitting structure, the heat generated by the LED platform is directly conducted to the color conversion structure, accelerating its aging and failure, thus limiting the lifespan of the full-color micro-display device.

[0005] Therefore, there is an urgent need to propose a microdisplay chip structure and fabrication method that can improve the utilization rate of the light-emitting area and extend the chip lifespan without crosstalk. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a Micro-LED microdisplay chip and its fabrication method. The chip utilizes a double-layer lattice structure to eliminate crosstalk channels, improve reflection efficiency and luminous utilization, thereby enhancing chip brightness, reliability, and lifespan.

[0007] The technical solution adopted in this application is as follows: In a first aspect, a Micro-LED microdisplay chip is provided, comprising: a driving substrate, a light-emitting structure, a lower grid structure, and an upper grid structure; The light-emitting structure includes: multiple LED platforms; Each LED platform is arranged at intervals on the driving substrate and is driven individually by the driving substrate. The lower-level grid structure includes: a metal grid substrate; The metal grid substrate forms multiple grid holes surrounding each LED platform, and the height of the metal grid substrate is not lower than that of each LED platform; The upper grid structure includes: multiple three-dimensional metal rings; Each three-dimensional metal ring has its own independently corresponding LED platform set on the metal grid substrate to prevent light leakage between the corresponding LED platforms inside the three-dimensional metal ring and the corresponding LED platforms outside the three-dimensional metal ring.

[0008] Optionally, each three-dimensional metal ring is set in a jump interval manner so that the two diagonally opposite LED platforms in the 2×2 unit correspond to the three-dimensional metal rings respectively.

[0009] Optionally, the lower grid structure may also include: a transparent resin and an inorganic dielectric layer; Transparent resin is placed inside each grid hole; An inorganic medium layer is coated on the transparent resin corresponding to each three-dimensional metal ring.

[0010] Optionally, the transparent resin corresponding to each three-dimensional metal ring is higher than the metal grid substrate and covers part of the upper surface of the metal grid substrate, while the remaining transparent resin is flush with the metal grid substrate. Each three-dimensional metal ring is disposed on the inorganic dielectric layer and the metal grid substrate.

[0011] Optionally, each three-dimensional metal ring has a multi-layer metal structure, and each three-dimensional metal ring includes: an inner metal layer, a metal interlayer, and an outer metal layer; The inner metal layer and the interlayer metal layer are disposed on the inorganic dielectric layer; The outer metal layer is disposed on the metal grid substrate; The metal interlayer is made of non-silver metal.

[0012] Optionally, the lateral dimension of each LED platform ranges from 0.5 to 10 μm, the lateral dimension of each grid hole ranges from 1.0 to 10.5 μm, and the lateral inner dimension of each three-dimensional metal ring ranges from 1.0 to 10.5 μm, and the lateral dimension of each grid hole and the lateral inner dimension of each three-dimensional metal ring are greater than the lateral dimension of the LED platform. The minimum wall thickness of the metal grid substrate is 0.1~0.5μm, and the wall thickness of each three-dimensional metal ring is 0.1~0.5μm.

[0013] Optional features also include: color conversion structure; The color conversion structure includes multiple color conversion units, which fill the areas not enclosed by the three-dimensional metal rings and within the three-dimensional metal rings.

[0014] Optionally, the thickness of the color conversion unit can range from 2 to 5 μm.

[0015] Optionally, the color conversion unit includes: a first color conversion unit and a second color conversion unit; The first form: The first color conversion unit fills the area not surrounded by each three-dimensional metal ring, and is used to convert the light emitted by the corresponding LED platform into the first color; the second color conversion unit fills part of the three-dimensional metal ring, and is used to convert the light emitted by the corresponding LED platform into the second color; Alternatively, in the second form: the first color conversion unit fills part of the three-dimensional metal ring and is used to convert the light emitted by the corresponding LED platform into the first color; the second color conversion unit fills the area not surrounded by each three-dimensional metal ring and is used to convert the light emitted by the corresponding LED platform into the second color. Alternatively, a third form may be used: a first color conversion unit is filled within a portion of the three-dimensional metal rings to convert the light emitted by the corresponding LED platform into the first color; a second color conversion unit is filled within the remaining three-dimensional metal rings to convert the light emitted by the corresponding LED platform into the second color.

[0016] Optionally, the color conversion unit may also include: a third color conversion unit; In the first and second forms, the third color conversion unit is filled inside the remaining three-dimensional metal ring and is used to convert the light emitted by the corresponding LED platform into the third color. Alternatively, in the third form, the third color conversion unit fills the area not enclosed by each three-dimensional metal ring, and is used to convert the light emitted by the corresponding LED platform into the third color.

[0017] Optionally, the color conversion unit may also include: a transparent resin unit; In the first and second forms, the transparent resin unit is filled inside the remaining three-dimensional metal ring to transmit the light emitted by the corresponding LED platform. Alternatively, in the third form, transparent resin units fill the areas not enclosed by each three-dimensional metal ring, allowing light emitted from the corresponding LED platform to be transmitted.

[0018] Optionally, the materials for the first color conversion unit, the second color conversion unit, and the third color conversion unit include quantum dots and / or phosphors.

[0019] Secondly, a method for fabricating a Micro-LED microdisplay chip is provided, comprising the following steps: Provide driving substrate; A light-emitting structure is formed; the light-emitting structure includes: multiple LED mesa; each LED mesa is arranged at intervals on the driving substrate and is driven individually by the driving substrate; A lower grid structure is formed; the lower grid structure includes: a metal grid substrate; the metal grid substrate forms multiple grid holes surrounding each LED platform, and the height of the metal grid substrate is not lower than that of each LED platform; A top-level grid structure is formed; the top-level grid structure includes: multiple three-dimensional metal rings; each three-dimensional metal ring has its own independently corresponding LED platform set on the metal grid substrate to prevent light leakage between the corresponding LED platforms inside the three-dimensional metal ring and the corresponding LED platforms outside the three-dimensional metal ring.

[0020] Optionally, forming a lower-level grid structure and forming an upper-level grid structure include: A metal grid substrate with multiple grid holes is formed around each LED platform, and its height is not lower than that of each LED platform; Spin-coat transparent resin and fill it to a level higher than the metal grid substrate; Depositing inorganic media materials on transparent resin; Photoresist residues are formed on the inorganic dielectric material corresponding to some LED platforms; Sputtering non-silver metal makes the thickness of the non-silver metal on the upper surface of the photoresist spot greater than the thickness of the non-silver metal on the side of the photoresist spot and the upper surface of the inorganic dielectric material. Vertical etching removes the non-silver metal on the upper surface of the photoresist residue, and removes the non-silver metal, inorganic dielectric material and transparent resin at the corresponding positions of the remaining LED mesa, so as to expose part of the metal grid substrate and form an inorganic dielectric layer and a metal interlayer. Oxygen plasma removes photoresist residue; Sputtering silver metal; Vertical etching removes the inorganic dielectric layer, metal interlayer, and silver metal from the upper surface of the transparent resin, forming an inner metal layer and an outer metal layer, thereby obtaining a three-dimensional metal ring.

[0021] Optionally, the photoresist spots are set in a skip interval manner so that the two diagonally opposite LED platforms in the 2×2 unit correspond to the photoresist spots respectively.

[0022] Optionally, the following steps may also be included: A color conversion structure is formed, which includes multiple color conversion units. These multiple color conversion units fill the areas not surrounded by each three-dimensional metal ring and within each three-dimensional metal ring.

[0023] Optionally, a color conversion structure is formed, including: The first form: fill the area not enclosed by each three-dimensional metal ring with a first color conversion unit, and fill the area within a portion of the three-dimensional metal ring with a second color conversion unit; Alternatively, in the second form, the first color conversion unit is filled inside a portion of the three-dimensional metal rings, and the second color conversion unit is filled in the areas not enclosed by each three-dimensional metal ring. Alternatively, a third approach could be used: fill some of the three-dimensional metal rings with the first color conversion unit and fill the remaining three-dimensional metal rings with the second color conversion unit.

[0024] Optionally, the color conversion structure may also include: In the first and second forms, a third color conversion unit is filled inside the remaining three-dimensional metal ring; Alternatively, in the third form, the areas not enclosed by each three-dimensional metal ring are filled with third-color conversion units.

[0025] Optionally, the color conversion unit also includes: In the first and second forms, the remaining three-dimensional metal ring is filled with transparent resin units; Alternatively, in the third form, transparent resin units are filled in the areas not surrounded by the three-dimensional metal rings.

[0026] The above-mentioned technical solution adopted in this application can achieve the following beneficial effects: The chip provided in this application includes: a driving substrate, a light-emitting structure, a lower grid structure, and an upper grid structure; the light-emitting structure includes: multiple LED mesa; each LED mesa is arranged at intervals on the driving substrate and is driven individually by the driving substrate; the lower grid structure includes: a metal grid substrate; the metal grid substrate forms multiple grid holes surrounding each LED mesa, and the height of the metal grid substrate is not lower than that of each LED mesa; the upper grid structure includes: multiple three-dimensional metal rings; each three-dimensional metal ring independently corresponds to a portion of the LED mesa disposed on the metal grid substrate to prevent light leakage between the corresponding LED mesa inside the three-dimensional metal ring and the corresponding LED mesa outside the three-dimensional metal ring.

[0027] The Micro-LED microdisplay chip proposed in this application forms a double-layer, three-dimensional, fully enclosed optical barrier structure through a metal grid substrate and a three-dimensional metal ring. It uses highly reflective metal to constrain the lateral light emission, eliminating the light crosstalk path caused by traditional structures, so that there is no light crosstalk between adjacent LED platforms, and the color purity and display contrast are greatly improved.

[0028] The Micro-LED microdisplay chip proposed in this application utilizes a metal grid substrate to quickly dissipate heat from the LED mesa, achieving efficient heat dissipation. By filling the grid holes with transparent resin, the low thermal conductivity of the transparent resin reduces heat transfer to the color conversion unit, preventing overheating and aging of the color conversion unit, and significantly improving chip reliability and lifespan.

[0029] The Micro-LED microdisplay chip proposed in this application uses an inorganic dielectric layer as an isolation and etching sacrificial layer to avoid direct contact between the lower transparent resin and the upper photoresist, thereby eliminating interface defects and improving product yield and structural stability.

[0030] The Micro-LED microdisplay chip proposed in this application adopts a two-stage molding process of sputtering and vertical etching, which simplifies the fabrication process of the three-dimensional metal ring. At the same time, it eliminates the traditional redundant resin support material, freeing up a large amount of pixel area space, avoiding the impact of resin support material aging on chip performance, and significantly improving the chip's lifespan. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A top view of a Micro-LED microdisplay chip according to a first embodiment of this application is shown; Figure 2 A schematic diagram of the AA cross-sectional structure of a Micro-LED microdisplay chip according to a first embodiment of this application is shown. Figure 3 A flowchart illustrating a method for fabricating a Micro-LED microdisplay chip according to an embodiment of this application is shown; Figure 4 A schematic cross-sectional view of the Micro-LED microdisplay chip according to the first embodiment of this application after the formation of the light-emitting structure is shown. Figure 5 A schematic cross-sectional view of the Micro-LED microdisplay chip according to the first embodiment of this application after forming a metal grid substrate is shown. Figure 6 A schematic cross-sectional view of the Micro-LED microdisplay chip after transparent resin filling according to the first embodiment of this application is shown. Figure 7 A schematic cross-sectional view of the Micro-LED microdisplay chip according to the first embodiment of this application after deposition of inorganic dielectric material is shown. Figure 8 A schematic cross-sectional view of a Micro-LED microdisplay chip according to a first embodiment of this application after photoresist dots have been formed; Figure 9 A schematic cross-sectional structure of a Micro-LED microdisplay chip according to a first embodiment of this application after sputtering non-silver metal is shown; Figure 10 A schematic cross-sectional view of a Micro-LED microdisplay chip according to a first embodiment of this application after vertical etching of non-silver metal is shown. Figure 11A schematic cross-sectional view of a Micro-LED microdisplay chip according to a first embodiment of this application after removing photoresist residue is shown. Figure 12 A schematic cross-sectional view of a Micro-LED microdisplay chip according to a first embodiment of this application after sputtering silver metal is shown. Figure 13 A schematic cross-sectional view of a Micro-LED microdisplay chip according to a first embodiment of this application after vertical etching of silver metal is shown. Figure 14 A schematic cross-sectional view of the Micro-LED microdisplay chip according to the second embodiment of this application after forming a color conversion structure is shown. Figure 15 A top view of a Micro-LED microdisplay chip according to a second embodiment of this application after forming a color conversion structure is shown; Figure 16 A cross-sectional view of the Micro-LED microdisplay chip according to the third embodiment of this application after forming a color conversion structure is shown. Figure 17 A top view of the Micro-LED microdisplay chip according to the third embodiment of this application after forming a color conversion structure is shown; Figure 18 A cross-sectional view of the Micro-LED microdisplay chip according to the fourth embodiment of this application after forming a color conversion structure is shown. Figure 19 A top view of the Micro-LED microdisplay chip according to the fourth embodiment of this application after forming a color conversion structure is shown; Figure 20 A cross-sectional view of the Micro-LED microdisplay chip according to the fifth embodiment of this application after forming a color conversion structure is shown. Figure 21 A top view of the Micro-LED microdisplay chip according to the fifth embodiment of this application after forming a color conversion structure is shown; Figure 22 A cross-sectional view of the Micro-LED microdisplay chip according to the sixth embodiment of this application after forming a color conversion structure is shown. Figure 23 A top view of the Micro-LED microdisplay chip according to the sixth embodiment of this application after forming a color conversion structure is shown. Detailed Implementation

[0032] Exemplary embodiments of this application will now be described in more detail. However, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0033] This invention discloses many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described herein. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0034] Generally, terms can be understood at least in part according to their usage in accordance with the invention. For example, the term "one or more" as used in this invention, depending at least in part on the invention, can be used to describe any component, structure, or feature in the singular, or in the plural to describe a combination of components, structures, or features. Similarly, terms such as "a," "an," or "the" can also be understood, depending at least in part on the invention, to convey either a singular or a plural usage. Furthermore, the term "based on..." can be understood not necessarily to convey an exclusive set of factors, but can instead, at least in part on the context, allow for additional factors that do not necessarily have to be explicitly described.

[0035] It should be noted that, in the description of this application, the terms “on,” “above,” “on top of,” “above,” etc., 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.”

[0036] For ease of description, this application may also use spatial relative terms such as “under,” “below,” “below,” “below,” “upper,” and “lower” to describe the relationship between one component and another component shown in the accompanying drawings. In addition to the orientations described in the drawings, the spatial relative terms are also intended to cover different orientations of the device during use or operation. The device may be oriented in other ways, and the spatial relative descriptions used in this application can be interpreted accordingly.

[0037] Figure 1 A top view of the Micro-LED microdisplay chip proposed in this application is shown. Figure 2 A schematic diagram of the AA cross-sectional structure of the Micro-LED microdisplay chip proposed in this application is shown. (Refer to...) Figures 1-2 The Micro-LED microdisplay chip proposed in this application is illustrated below.

[0038] The Micro-LED microdisplay chip proposed in this application includes: a driving substrate 1, a light-emitting structure 2, a lower grid structure 3, and an upper grid structure 4.

[0039] The light-emitting structure 2 includes: multiple LED platforms 21; Multiple LED platforms 21 are arranged at intervals on the driving substrate 1, and each LED platform 21 is driven individually by the driving substrate 1.

[0040] The lower grid structure 3 includes: a metal grid substrate 31; The metal grid substrate 31 forms a plurality of grid holes surrounding each LED platform 21, and the height of the metal grid substrate 31 is not lower than that of each LED platform 21; The upper grid structure 4 includes: multiple three-dimensional metal rings 41; Each three-dimensional metal ring 41 has an independently corresponding portion of the LED platform 21 set on the metal grid base 31 to prevent light leakage between the corresponding LED platform 21 inside the three-dimensional metal ring 41 and the corresponding LED platform 21 outside the three-dimensional metal ring 41.

[0041] The driving substrate 1 may include a substrate 11, a driving circuit, and multiple contacts connected to the driving circuit (the multiple contacts may include a first contact 12 and a second contact 13). 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 the 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.

[0042] Multiple LED mesa 21 can be arranged on the driving substrate 1 in a regular or irregular manner. The driving substrate 1 can refer to the control panel of the multiple LED mesa 21. The driving substrate 1 generates driving signals based on the image to be displayed and applies them to the multiple LED mesa 21, so that each LED mesa 21 independently releases a light beam in response to the driving signals.

[0043] The LED display panel 21 can be a miniature light-emitting diode (LED) or a miniature organic light-emitting diode (OLED). The miniature LED is formed based on inorganic semiconductor materials, such as gallium nitride, aluminum gallium nitride, gallium arsenide, and aluminum gallium indium phosphide. The miniature OLED is formed based on organic materials, such as small molecules, polymers, and phosphorescent materials.

[0044] Each LED platform 21 can be trapezoidal in shape. That is, the sidewalls of the LED platform 21 can be sloping, and the angle between the sidewalls and the top surface of the LED platform 21 can be obtuse, thereby improving the light-focusing effect of the LED platform 21. Of course, the LED platform 21 can also be columnar, in which case the angle between the sidewalls and the top surface of the LED platform 21 is a right angle.

[0045] The Micro-LED microdisplay chip can be a common cathode structure, a common anode structure, or each chip can be independent. Figure 2 In the case shown, the Micro-LED microdisplay chip has a common cathode structure.

[0046] Specifically, each LED mesa 21 may include a first electrode layer 211, a bonding layer 212 disposed on the first electrode layer 211, and an epitaxial layer 213 disposed on the bonding layer 212. Multiple LED mesa 21 are respectively connected to multiple first contacts 12 (anode contacts) of the driving substrate 1. Passivation layers 22 are disposed on the sidewalls of the first electrode layer 211, the bonding layer 212, and the epitaxial layer 213. A transparent electrode layer 23 covers the multiple LED mesa 21, the passivation layer 22, and the driving substrate 1. The transparent electrode layer 23 is connected to the epitaxial layer 213 of each LED mesa 21 and to the second contacts 13 (cathode contacts) of the driving substrate 1. In this case, the multiple LED mesa 21 form a common cathode structure through a common cathode—the transparent electrode layer 23.

[0047] For an LED platform 21, its first electrode layer 211 is connected to a first contact 12 of the driving substrate 1. A bonding layer 212 is disposed on the first electrode layer 211. The material of the first electrode layer 211 can be a metal or a metal alloy, including indium tin oxide, chromium, platinum, gold, aluminum, germanium, tin, indium, copper, or titanium, etc.

[0048] An epitaxial layer 213 is disposed on the bonding layer 212. The epitaxial layer 213 may include a first doped semiconductor layer, a light-emitting layer, and a second doped semiconductor layer stacked together. The first doped semiconductor layer may be a p-type GaN or InGaN layer formed by doping or ion implantation, etc., and the first doped semiconductor layer may be a multilayer structure. The second doped semiconductor layer may be an n-type GaN or InGaN layer formed by doping or ion implantation, etc., and the second doped semiconductor layer may also be a multilayer structure. The light-emitting layer is a layer that outputs light of a specific wavelength based on the recombination of holes provided by the first doped semiconductor layer and electrons provided by the second doped semiconductor layer. The light-emitting layer may have a single quantum well structure or a multiple quantum well (MQW) structure, and may also have well layers and barrier layers stacked alternately.

[0049] The passivation layer 22 covers the sidewalls of the first electrode layer 211, the bonding layer 212, and the epitaxial layer 213. The material of the passivation layer 22 may include inorganic or organic materials. Inorganic materials may include, but are not limited to, any one or a combination of silicon dioxide, aluminum oxide, zirconium dioxide, titanium dioxide, silicon nitride, and hafnium oxide; organic materials include any one or a combination of black matrix photoresist, color filter photoresist, polyimide, bank adhesive, overcoat adhesive, near-ultraviolet negative photoresist, and styrene.

[0050] A transparent electrode layer 23 is covered on multiple LED mesa 21, passivation layer 22, and driving substrate 1. The transparent electrode layer 23 is connected to the epitaxial layer 213 of each LED mesa 21 and to the second contact 13 of the driving substrate 1. The transparent electrode layer 23 can be a conductive and highly transparent thin film material, which may include: indium tin compound, conductive SiO2, conductive PI, molybdenum, silver, etc.

[0051] The light-emitting structure 2 has a lower grid structure 3, which includes a metal grid substrate 31.

[0052] The metal grid substrate 31 forms multiple grid holes surrounding each LED mesa 21, and its height is not lower than that of each LED mesa 21. That is, the multiple grid holes can be arranged in a regular or irregular manner depending on the arrangement of each LED mesa 21. In order to improve the uniformity of light emission of each LED mesa 21, each LED mesa 21 can be set at the center of the corresponding grid hole.

[0053] The sidewalls of the grid holes can be straight or inclined, meaning the angle between the sidewall of the grid hole and the top surface of the metal grid substrate 31 can be a right angle or an obtuse angle. (Refer to...) Figure 2As shown, in the direction away from the driving substrate 1, the lateral dimension of the grid holes can remain constant or gradually increase. Generally, this cross-section can be a circular cross-section or a square cross-section, and of course, it can also be an irregularly shaped cross-section.

[0054] The main functions of the metal grid substrate 31 include the following aspects: First, it can form an all-round optical barrier and reflection constraint on the light emitted by each LED mesa 21, blocking light crosstalk between adjacent LED mesa 21 and realizing the anti-crosstalk function; Second, it utilizes the excellent thermal conductivity of the metal itself to quickly conduct the heat generated by the LED mesa 21 during operation, realizing efficient heat conduction and heat dissipation, avoiding heat accumulation inside the pixel, thereby improving the chip's working stability and service life.

[0055] An upper grid structure 4 is located on the lower grid structure 3. The upper grid structure 4 includes multiple three-dimensional metal rings 41. According to the arrangement of multiple LED mesa 21 and grid holes, multiple three-dimensional metal rings 41 are independently disposed on the metal grid base 31 corresponding to a portion of the LED mesa 21.

[0056] In some alternative embodiments, the three-dimensional metal rings 41 are arranged in a skip interval manner so that the two diagonally opposite LED platforms 21 in the 2×2 unit correspond to the three-dimensional metal rings 41 respectively.

[0057] In practice, the arrangement of the three-dimensional metal rings 41 is not limited to a 2×2 unit. It can also be arranged in a 3×3 unit, with the three LED platforms 21 on the diagonal lines corresponding to the three-dimensional metal rings 41; or in a 4×4 unit, with the four LED platforms 21 on the diagonal lines corresponding to the three-dimensional metal dielectric rings 41. In more extended cases, the arrangement of the three-dimensional metal rings 41 does not need to be regular, as long as they are distributed and correspond to a portion of the LED platforms 21. That is to say, the core function of the upper grid structure 4 is to divide the multiple LED platforms 21 into a part surrounded by the three-dimensional metal rings 41 and another part not surrounded by the three-dimensional metal rings 41.

[0058] Correspondingly, in some optional embodiments, the lower grid structure 3 further includes: transparent resin 32 and inorganic dielectric layer 33; transparent resin 32 is disposed in each grid hole; and inorganic dielectric layer 33 is covered on the transparent resin 32 corresponding to each three-dimensional metal ring 41.

[0059] Each grid hole contains a transparent resin 32, and an inorganic dielectric layer 33 is covered on the transparent resin 32 in a skip-interval manner. Taking 2×2 as the basic unit, the transparent resin 32 in the first group of positions distributed diagonally is covered with an inorganic dielectric layer 33, while the transparent resin 32 in the second group of positions distributed diagonally is not covered with an inorganic dielectric layer 33.

[0060] Furthermore, in some optional embodiments, the transparent resin 32 corresponding to each three-dimensional metal ring 41 is higher than the metal grid substrate 31 and covers part of the upper surface of the metal grid substrate 31, while the remaining transparent resin 32 is flush with the metal grid substrate 31; each three-dimensional metal ring 41 is disposed on the inorganic dielectric layer 33 and the metal grid substrate 31.

[0061] That is, refer to Figure 2 As shown, the positions of the left LED platform 21 and the right LED platform 21 correspond to the second group of positions, where the transparent resin 32 is higher than the metal grid substrate 31 and covers part of the upper surface of the metal grid substrate 31; the position of the middle LED platform 21 corresponds to the first group of positions, where the transparent resin 32 is flush with the metal grid substrate 31.

[0062] The main functions of the transparent resin 32 are as follows: First, it utilizes the low thermal conductivity of the resin material to achieve heat insulation, preventing the heat generated by the LED mesa 21 from being conducted upwards to the color conversion structure 5, and reducing lateral thermal crosstalk between pixels. Second, during the fabrication process, the filling height of the transparent resin 32 is slightly higher than that of the metal grid substrate 31, allowing it to serve as an etching sacrificial layer for subsequent etching steps, thus enabling the precise forming of the three-dimensional metal ring 41 in conjunction with the process.

[0063] An inorganic medium layer 33 is applied to the transparent resin 32 at the second location.

[0064] The inorganic dielectric layer 33 has the following main functions: Firstly, during the fabrication process, the inorganic dielectric layer 33 can block the direct contact between the transparent resin 32 below and the photoresist, preventing the transparent resin 32 and the photoresist from directly contacting each other and causing mutual dissolution, thereby resulting in interface damage; Secondly, during the fabrication process, the inorganic dielectric layer 33 can serve as an etching sacrificial layer for subsequent etching steps, cooperating with the process to achieve precise forming of the three-dimensional metal ring 41.

[0065] When the aforementioned three-dimensional metal rings 41 are arranged in a skip interval manner, i.e., referring to Figure 2 As shown, the left LED platform 21 and the right LED platform 21 (second group position) each have a three-dimensional metal ring 41.

[0066] The three-dimensional metal ring 41 can be a circular ring, a square ring, or an irregular shape. Preferably, the shape of the three-dimensional metal ring 41 corresponds to the shape of the corresponding grid hole.

[0067] In some optional embodiments, each three-dimensional metal ring 41 is a multi-layer metal structure, including: an inner metal layer 411, a metal interlayer 412, and an outer metal layer 413. The inner metal layer 411 and the interlayer metal 412 are disposed on the inorganic dielectric layer 33; The outer metal layer 413 is disposed on the metal grid substrate 31; The metal interlayer 412 is a non-silver metal.

[0068] The inner metal layer 411, the interlayer metal 412, and the outer metal layer 413 together form a continuous, closed three-dimensional enclosed structure to ensure the integrity of optical reflection and sidewall blocking. The interlayer metal 412 is made of a non-silver metal because silver is highly reactive during fabrication and can be damaged by oxygen in a plasma environment during photoresist removal.

[0069] In some optional embodiments, a color conversion structure 5 is also included. The color conversion structure 5 includes a plurality of color conversion units that fill the areas not surrounded by the plurality of three-dimensional metal rings 41 and within the plurality of three-dimensional metal rings 41.

[0070] Color conversion units are filled in each three-dimensional metal ring 41 and in areas not surrounded by multiple three-dimensional metal rings 41 to form a color conversion structure 5.

[0071] In some alternative implementations, when the LED platform 21 does not emit blue light, a first color conversion unit 51 is filled in the area not surrounded by the plurality of three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in part of the three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the remaining part of the three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0072] Alternatively, when the LED platform 21 does not emit blue light, a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0073] Alternatively, when the LED platform 21 does not emit blue light, a first color conversion unit 51 is filled within a portion of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled within a portion of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0074] In some alternative embodiments, when the LED platform 21 emits blue light, a first color conversion unit 51 is filled in the area not surrounded by the plurality of three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in part of the three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and transparent resin units 53 are filled in the remaining part of the three-dimensional metal rings 41 to directly transmit the light (blue light) emitted by the corresponding LED platform 21.

[0075] Alternatively, when the LED platform 21 emits blue light, a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and transparent resin units 53 are filled in the remaining part of the three-dimensional metal ring 41 to directly transmit the light emitted by the corresponding LED platform 21 (blue light).

[0076] Alternatively, when the LED platform 21 emits blue light, a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and transparent resin units 53 are filled in the areas not surrounded by the multiple three-dimensional metal rings 41, so that the light emitted by the corresponding LED platform 21 (blue light) can be directly transmitted.

[0077] Through the above-described implementation methods, when a pixel unit corresponds to at least one LED platform 21 corresponding to the first color conversion unit 51, one LED platform 21 corresponding to the second color conversion unit 52, and one LED platform 21 corresponding to the third color conversion unit 54, or when a pixel unit corresponds to at least one LED platform 21 corresponding to the first color conversion unit 51, one LED platform 21 corresponding to the second color conversion unit 52, and one LED platform 21 corresponding to the transparent resin unit 53, full-color display of the Micro-LED microdisplay chip can be achieved.

[0078] The first color conversion unit 51, the second color conversion unit 52, and the third color conversion unit 54 can all be photoluminescent color conversion materials, which may include quantum dots and / or phosphors. The phosphors may be yttrium aluminum garnet, cerium phosphors, (oxy)nitride phosphors, silicate phosphors, and Mn4+ 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.

[0079] The material of the transparent resin unit 53 can be polymethyl methacrylate (PMMA).

[0080] For the Micro-LED microdisplay chip proposed in this application, the lateral dimension of each LED mesa 21 ranges from 0.5 to 10 μm. The lateral dimension of each grid hole ranges from 1.0 to 10.5 μm, and the lateral inner dimension of each three-dimensional metal ring 41 ranges from 1.0 to 10.5 μm. Furthermore, the lateral dimension of each grid hole and the lateral inner dimension of each three-dimensional metal ring 41 are larger than the lateral dimension of the LED mesa 21.

[0081] The dimensions of the grid holes and the three-dimensional metal ring 41 must match the dimensions of the LED platform 21 to ensure that the grid holes can fully expose the LED platform 21 and that the three-dimensional metal ring 41 can completely surround the corresponding position of the LED platform 21, so as to prevent the light emitted by the LED platform 21 from leaking into the adjacent area.

[0082] The minimum wall thickness of the metal grid substrate 31 is 0.1~0.5μm, and the wall thickness of each three-dimensional metal ring 41 is 0.1~0.5μm. This wall thickness ensures that the metal grid substrate 31 and each three-dimensional metal ring 41 have sufficient structural strength and reflectivity to achieve effective optical blocking, while also reducing the space occupied by the three-dimensional metal ring 41 in the pixel area.

[0083] The material of the three-dimensional metal ring 41 can be a metal material with high reflectivity to achieve light reflection, thereby preventing light crosstalk between different colors.

[0084] The thickness of the color conversion unit ranges from 2 to 5 μm. This thickness ensures that the color conversion unit can fully absorb the light emitted by the LED mesa 21 and convert it into the target color, while avoiding light scattering loss and manufacturing difficulties caused by excessive thickness.

[0085] Figure 3 A schematic flowchart illustrating a method for fabricating a Micro-LED microdisplay chip according to an embodiment of this application is shown. (Refer to...) Figure 3 The preparation method proposed in this application includes the following steps: Step S1, provide driving substrate 1; Step S2, forming a light-emitting structure 2; the light-emitting structure 2 includes: multiple LED mesa 21; each LED mesa 21 is arranged at intervals on the driving substrate 1 and is driven individually by the driving substrate 1.

[0086] Step S3, forming a lower grid structure 3; the lower grid structure 3 includes: a metal grid substrate 31; the metal grid substrate 31 forms a plurality of grid holes surrounding each LED platform 21, and the height of the metal grid substrate 31 is not lower than that of each LED platform 21; Step S4: Form an upper grid structure 4. The upper grid structure 4 includes: multiple three-dimensional metal rings 41; each three-dimensional metal ring 41 has an independently corresponding portion of the LED platform 21 disposed on the metal grid substrate 31 to prevent light leakage between the corresponding LED platform 21 inside the three-dimensional metal ring 41 and the corresponding LED platform 21 outside the three-dimensional metal ring 41.

[0087] In some alternative implementations, the following steps are also included: Step S5: Forming a color conversion structure 5, which includes multiple color conversion units, which fill the areas not surrounded by multiple three-dimensional metal rings 41 and within the multiple three-dimensional metal rings 41.

[0088] In some alternative implementations, forming a lower grid structure 3 and forming an upper grid structure 4 includes: A metal grid base 31 is formed around each LED platform 21, having multiple grid holes and a height not lower than that of each LED platform 21; Spin-coat transparent resin 32 and fill it to a height above the metal grid substrate 31; Inorganic dielectric material 33-1 is deposited on transparent resin 32; Photoresist residue 6 is formed on the inorganic dielectric material 33-1 corresponding to part of the LED platform 21; Sputter non-silver metal 412-1 so that the thickness of non-silver metal 412-1 on the upper surface of photoresist spot 6 is greater than the thickness of non-silver metal 412-1 on the side of photoresist spot 6 and on the upper surface of inorganic dielectric material 33-1. Vertical etching removes the non-silver metal 412-1 on the upper surface of the photoresist residue 6, and removes the non-silver metal 412-1, inorganic dielectric material 33-1 and transparent resin 32 at the corresponding positions of the remaining LED mesa 21 to expose part of the metal grid substrate 31, forming an inorganic dielectric layer 33 and a metal interlayer 412. Oxygen plasma removes photoresist residue at point 6; Sputtered silver metal 41-1; Vertical etching removes the silver metal 41-1 from the surface of the inorganic dielectric layer 33, the metal interlayer 412, and the transparent resin 32, forming an inner metal layer 411 and an outer metal layer 413, thereby obtaining a three-dimensional metal ring 41.

[0089] The following example illustrates the fabrication method of a Micro-LED microdisplay chip, using a configuration of multiple three-dimensional metal rings 41 arranged in a skip-interval manner so that the corresponding positions of two diagonally opposite LED platforms 21 in a 2×2 unit correspond to the three-dimensional metal rings 41.

[0090] Figures 4 to 13 , Figures 1 to 2 A schematic diagram illustrating different stages in the fabrication process of the Micro-LED microdisplay chip according to the first embodiment is shown. See also Figures 4 to 13 and Figures 1 to 2 The fabrication method of the Micro-LED microdisplay chip in this embodiment will be described in detail.

[0091] Figure 4 A schematic cross-sectional view of the structure after forming multiple light-emitting structures 2 is shown. See also some embodiments of this application. Figure 4 Forming a light-emitting structure 2, comprising: A substrate is provided, an epitaxial material is grown on the substrate, and a first bonding material is grown on the epitaxial material.

[0092] 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, etc., 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 plurality of first contacts 12 and second contacts 13. A first electrode material and a second bonding material are grown on the driving substrate 1.

[0093] The epitaxial material, the first bonding material, the first electrode material, and the second bonding material can be formed by deposition.

[0094] The first and second bonding materials are metallically bonded together, and the substrate is then peeled off from the epitaxial material. Substrate peeling methods include, but are not limited to, laser peeling, dry etching, wet etching, and mechanical polishing.

[0095] Thinning operations are performed on epitaxial materials, including dry etching, wet etching, or mechanical polishing.

[0096] Based on the MESA pattern designed using a patterned mask, the epitaxial material is etched, followed by the etching of the bonding material and the first electrode material. The etched epitaxial material forms multiple epitaxial layers 213, the etched bonding material forms multiple bonding layers 212, and the etched first electrode material forms multiple first electrode layers 211. Each first electrode layer 211 is connected to each first contact 12, each bonding layer 212 is located on each first electrode layer 211, and each epitaxial layer 213 is located on each bonding layer 212. Etching can be performed using either dry or wet methods.

[0097] Passivation layers 22 are deposited on the side surfaces of multiple epitaxial layers 213, multiple bonding layers 212, and multiple first electrode layers 211 to form multiple LED mesa 21. Transparent electrode material is deposited on the multiple LED mesa 21 and the driving substrate 1 to form a transparent electrode layer 23. The transparent electrode layer 23 connects each epitaxial layer 213 and a second contact 13, thereby forming a light-emitting structure 2.

[0098] Figure 5 A schematic cross-sectional view of the structure after the metal grid substrate 31 is formed is shown. See also some embodiments of this application. Figure 5 The metal grid substrate 31 is formed by: forming a metal grid substrate 31 around multiple LED platforms 21 based on a MESA pattern designed by a patterned mask, and the height of the metal grid substrate 31 is not lower than that of each LED platform 21.

[0099] Figure 6 A schematic cross-sectional view of the structure after the transparent resin 32 has been filled is shown. See also some embodiments of this application. Figure 6 The process of filling with transparent resin 32 includes: spin-coating transparent resin 32 and filling it above the metal grid substrate 31.

[0100] Figure 7 A schematic cross-sectional view of the structure after deposition of inorganic media material 33-1 is shown. See also some embodiments of this application. Figure 7 Depositing inorganic media material 33-1 includes: depositing inorganic media material 33-1 on transparent resin 32.

[0101] Figure 8 A schematic cross-sectional view of the structure after the formation of photoresist residue point 6 is shown. See also some embodiments of this application. Figure 8 The formation of photoresist spots 6 includes: forming photoresist spots 6 on the inorganic dielectric material 33-1 at the second set of positions. That is, patterned spots are formed on the inorganic dielectric material 33-1 by photoresist in a skip-interval manner, so that the second set of positions has photoresist spots 6.

[0102] Figure 9 A schematic cross-sectional view of the structure after sputtering non-silver metal 412-1 is shown. See also some embodiments of this application. Figure 9 The process involves sputtering non-silver metal 412-1, such that the thickness of the non-silver metal 412-1 on the upper surface of the photoresist dot 6 is greater than the thickness of the non-silver metal 412-1 on the sides of the photoresist dot 6 and the upper surface of the inorganic dielectric material 33-1. The sputtering will result in the non-silver metal 412-1 on the upper surface of the photoresist dot 6 being thicker than other parts; the specific ratio depends on the ratio of the spacing to the height of the photoresist dot 6.

[0103] Figure 10 A schematic cross-sectional view of the non-silver metal 412-1 after vertical etching is shown. See also some embodiments of this application. Figure 10 As shown, vertical etching of non-silver metal 412-1 includes: vertically etching to remove non-silver metal 412-1 from the upper surface of the photoresist residue 6, and removing non-silver metal 412-1, inorganic dielectric material 33-1, and transparent resin 32 from the first set of locations to expose part of the metal grid substrate 31, forming an inorganic dielectric layer 33 and a metal interlayer 412. This is achieved through Ar... + Ions are used for vertical etching. Since the thickness of the non-silver metal 412-1 on the upper surface of the photoresist residue 6 is greater than that of other parts, the non-silver metal 412-1 at the first position is removed together during the etching process of removing the non-silver metal 412-1 on the upper surface of the photoresist residue 6, and the inorganic dielectric material 33-1 and the transparent resin 32 will become etching sacrificial layers.

[0104] Figure 11 A schematic cross-sectional view of the structure after removing photoresist residue point 6 is shown. See also some embodiments of this application. Figure 11 As shown, removing the photoresist residue 6 includes: removing the photoresist residue 6 using oxygen plasma. At this time, the side of the transparent resin 32 filled at the second location will be exposed at the first location.

[0105] Figure 12 A schematic cross-sectional view of the structure after sputtering silver metal 41-1 is shown. See also some embodiments of this application. Figure 12 As shown, the sputtered silver metal 41-1 includes: sputtering silver metal 41-1 on the surface of the structure.

[0106] Figure 13 A schematic cross-sectional view of the structure after vertical etching of silver metal 41-1 is shown. See also some embodiments of this application. Figure 13As shown, vertical etching of silver metal 41-1 includes: vertically etching away the silver metal 41-1 from the inorganic dielectric layer 33, the metal interlayer 412, and the upper surface of the transparent resin 32, forming an inner metal layer 411 and an outer metal layer 413, thereby obtaining a three-dimensional metal ring 41. Due to the vertical etching, the side of the transparent resin 32 exposed at the first position is sealed, thereby blocking the light transmission channel. Figure 12 and Figure 13 The steps can achieve the preparation of the metal inner layer 411 and the metal outer layer 413 without glue application.

[0107] Figure 2 A schematic diagram of the cross-sectional structure after the formation of color conversion structure 5 is shown. Figure 1 A top view is shown after the color conversion structure 5 has been formed. See also Figures 1-2 , Figure 2 The cross-section shown is Figure 1 The AA section in the image. In some embodiments of this application, a color conversion structure 5 is formed, comprising: filling the area not surrounded by each three-dimensional metal ring 41 with a first color conversion unit 51, filling a portion of the three-dimensional metal ring 41 with a second color conversion unit 52, and filling the remaining portion of the three-dimensional metal ring 41 with a third color conversion unit 54.

[0108] When the LED platform 21 does not emit blue light (e.g., UV LED), the areas not enclosed by each three-dimensional metal ring 41 are filled with a first color conversion unit 51 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0109] Figures 14-15 A cross-sectional view and a top view are shown after the color conversion structure 5 is formed during the fabrication process of the Micro-LED microdisplay chip of the second embodiment. (See also...) Figures 14-15 , Figure 14 The cross-section shown is Figure 15 The BB cross-section in the image. In some embodiments of this application, a color conversion structure 5 is formed, comprising: filling a first color conversion unit 51 within a portion of the three-dimensional metal ring 41, filling a second color conversion unit 52 within the area not surrounded by the plurality of three-dimensional metal rings 41, and filling a third color conversion unit 54 within the remaining portion of the three-dimensional metal ring 41.

[0110] When the LED platform 21 does not emit blue light (e.g., UV LED), a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0111] Figures 16-17 A cross-sectional view and a top view are shown after the color conversion structure 5 is formed during the fabrication process of the Micro-LED microdisplay chip of the third embodiment. See also Figures 16-17 , Figure 16 The cross-section shown is Figure 17 The CC section in the image. In some embodiments of this application, a color conversion structure 5 is formed, including: filling a first color conversion unit 51 within a portion of the three-dimensional metal ring 41, filling a second color conversion unit 52 within the remaining portion of the three-dimensional metal ring 41, and filling a third color conversion unit 54 in the area not surrounded by the plurality of three-dimensional metal rings 41.

[0112] When the LED platform 21 does not emit blue light (e.g., UV LED), a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and a third color conversion unit 54 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a third color (e.g., blue).

[0113] Figures 18-19 A cross-sectional view and a top view are shown after the color conversion structure 5 is formed during the fabrication process of the Micro-LED microdisplay chip of the fourth embodiment. See also Figures 18-19 , Figure 18 The cross-section shown is Figure 19 The DD cross-section in the image. In some embodiments of this application, a color conversion structure 5 is formed, comprising: filling a first color conversion unit 51 in the area not surrounded by each three-dimensional metal ring 41, filling a second color conversion unit 52 in a portion of the three-dimensional metal ring 41, and filling a transparent resin unit 53 in the remaining portion of the three-dimensional metal ring 41.

[0114] When the LED platform 21 emits blue light (e.g., BlueLED), the areas not enclosed by each three-dimensional metal ring 41 are filled with a first color conversion unit 51 to convert the light emitted by the corresponding LED platform 21 into a first color (e.g., green); a second color conversion unit 52 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (e.g., red); and transparent resin units 53 are filled in the remaining part of the three-dimensional metal ring 41 to directly transmit the light emitted by the corresponding LED platform 21 (blue light).

[0115] Figures 20-21 A cross-sectional view and a top view are shown after the color conversion structure 5 is formed during the fabrication process of the Micro-LED microdisplay chip of the fifth embodiment. See also Figures 20-21 , Figure 20 The cross-section shown is Figure 21 The EE cross-section in the image. In some embodiments of this application, a color conversion structure 5 is formed, comprising: filling a first color conversion unit 51 within a portion of the three-dimensional metal ring 41, filling a second color conversion unit 52 within the area not surrounded by the plurality of three-dimensional metal rings 41, and filling a transparent resin unit 53 within the remaining portion of the three-dimensional metal ring 41.

[0116] When the LED platform 21 emits blue light (such as BlueLED), a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (such as green); a second color conversion unit 52 is filled in the area not surrounded by the multiple three-dimensional metal rings 41 to convert the light emitted by the corresponding LED platform 21 into a second color (such as red); and transparent resin units 53 are filled in the remaining part of the three-dimensional metal ring 41 to directly transmit the light emitted by the corresponding LED platform 21 (blue light).

[0117] Figures 22-23 A cross-sectional view and a top view are shown after the color conversion structure 5 is formed during the fabrication process of the Micro-LED microdisplay chip of the sixth embodiment. See also Figures 22-23 , Figure 22 The cross-section shown is Figure 23 The FF cross-section in the image. In some embodiments of this application, a color conversion structure 5 is formed, comprising: filling a first color conversion unit 51 within a portion of the three-dimensional metal ring 41, filling a second color conversion unit 52 within the remaining portion of the three-dimensional metal ring 41, and filling transparent resin units 53 in areas not surrounded by the plurality of three-dimensional metal rings 41.

[0118] When the LED platform 21 emits blue light (such as BlueLED), a first color conversion unit 51 is filled in part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a first color (such as green); a second color conversion unit 52 is filled in the remaining part of the three-dimensional metal ring 41 to convert the light emitted by the corresponding LED platform 21 into a second color (such as red); and transparent resin units 53 are filled in the areas not surrounded by the multiple three-dimensional metal rings 41, so that the light emitted by the corresponding LED platform 21 (blue light) can be directly transmitted.

[0119] The above description is merely a specific embodiment of this application. Under the guidance of the above teachings, 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 this application, and the scope of protection of this application should be determined by the scope of the claims.

[0120] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Claims

1. A Micro-LED microdisplay chip, characterized in that, include: Driving substrate, light-emitting structure, lower grid structure and upper grid structure; The light-emitting structure includes: multiple LED platforms; Each of the LED platforms is arranged at intervals on the driving substrate and is driven individually by the driving substrate. The lower grid structure includes: a metal grid substrate, a transparent resin, and an inorganic dielectric layer; The metal grid substrate forms a plurality of grid holes surrounding each of the LED platforms, the height of the metal grid substrate is not lower than that of each of the LED platforms, and the transparent resin is disposed in each of the grid holes; The upper grid structure includes: multiple three-dimensional metal rings; Each of the three-dimensional metal rings has its own independently corresponding portion of the LED platform disposed on the metal grid substrate to prevent light leakage between the corresponding LED platforms inside the three-dimensional metal ring and the corresponding LED platforms outside the three-dimensional metal ring; the three-dimensional metal rings are arranged in a skip interval manner so that two diagonally opposite LED platforms in the 2×2 unit correspond to the three-dimensional metal rings respectively; each three-dimensional metal ring is disposed on the inorganic dielectric layer and the metal grid substrate; the inorganic dielectric layer is covered on the transparent resin corresponding to each three-dimensional metal ring.

2. The Micro-LED microdisplay chip according to claim 1, characterized in that, The transparent resin corresponding to each of the three-dimensional metal rings is higher than the metal grid substrate and covers part of the upper surface of the metal grid substrate, while the remaining transparent resin is flush with the metal grid substrate.

3. The Micro-LED microdisplay chip according to claim 2, characterized in that, Each of the three-dimensional metal rings has a multi-layer metal structure, and each of the three-dimensional metal rings includes: an inner metal layer, a metal interlayer, and an outer metal layer; The inner metal layer and the interlayer metal layer are disposed on the inorganic dielectric layer; The outer metal layer is disposed on the metal grid substrate; The metal interlayer is a non-silver metal.

4. The Micro-LED microdisplay chip according to claim 1, characterized in that, The lateral dimension of each LED platform ranges from 0.5 to 10 μm, the lateral dimension of each grid hole ranges from 1.0 to 10.5 μm, and the lateral inner dimension of each three-dimensional metal ring ranges from 1.0 to 10.5 μm. Furthermore, the lateral dimension of each grid hole and the lateral inner dimension of each three-dimensional metal ring are greater than the lateral dimension of the LED platform. The minimum wall thickness of the metal grid substrate is 0.1~0.5μm, and the wall thickness of each of the three-dimensional metal rings is 0.1~0.5μm.

5. The Micro-LED microdisplay chip according to claim 1, characterized in that, Also includes: Color conversion structure; The color conversion structure includes multiple color conversion units, which fill the areas not enclosed by the three-dimensional metal rings and within the three-dimensional metal rings.

6. The Micro-LED microdisplay chip according to claim 5, characterized in that, The thickness of the color conversion unit ranges from 2 to 5 μm.

7. The Micro-LED microdisplay chip according to claim 6, characterized in that, The color conversion unit includes: a first color conversion unit and a second color conversion unit; In the first configuration: the first color conversion unit fills the area not enclosed by each of the three-dimensional metal rings, and is used to convert the light emitted by the corresponding LED platform into a first color; the second color conversion unit fills a portion of the three-dimensional metal rings, and is used to convert the light emitted by the corresponding LED platform into a second color; Alternatively, in the second form: the first color conversion unit fills a portion of the three-dimensional metal rings to convert the light emitted by the corresponding LED platform into a first color; the second color conversion unit fills the area not enclosed by each of the three-dimensional metal rings to convert the light emitted by the corresponding LED platform into a second color. Alternatively, in a third form: the first color conversion unit fills a portion of the three-dimensional metal rings to convert the light emitted by the corresponding LED platform into a first color; the second color conversion unit fills the remaining three-dimensional metal rings to convert the light emitted by the corresponding LED platform into a second color.

8. The Micro-LED microdisplay chip according to claim 7, characterized in that, The color conversion unit further includes: a third color conversion unit; In the first and second forms, the third color conversion unit fills the remaining portion of the three-dimensional metal ring and is used to convert the light emitted by the corresponding LED platform into a third color. Alternatively, in a third form, the third color conversion unit fills the area not enclosed by each of the three-dimensional metal rings, and is used to convert the light emitted by the corresponding LED platform into a third color.

9. The Micro-LED microdisplay chip according to claim 7, characterized in that, The color conversion unit further includes: a transparent resin unit; In the first and second forms, the transparent resin unit fills the remaining portion of the three-dimensional metal ring for transmitting light emitted by the corresponding LED platform. Alternatively, in a third embodiment, the transparent resin unit fills the area not surrounded by each of the three-dimensional metal rings to transmit light emitted from the corresponding LED platform.

10. The Micro-LED microdisplay chip according to claim 8, characterized in that, The materials of the first color conversion unit, the second color conversion unit, and the third color conversion unit include quantum dots and / or phosphors.

11. A method for fabricating a Micro-LED microdisplay chip, characterized in that, Includes the following steps: Provide driving substrate; Forming a light-emitting structure; The light-emitting structure includes: multiple LED mesa; each LED mesa is arranged at intervals on the driving substrate and is driven individually by the driving substrate; A lower grid structure is formed; the lower grid structure includes: a metal grid substrate, transparent resin and an inorganic dielectric layer; the metal grid substrate forms a plurality of grid holes surrounding each of the LED platforms, the height of the metal grid substrate is not lower than each of the LED platforms, and the transparent resin is respectively disposed in each of the grid holes; A top-layer grid structure is formed; the top-layer grid structure includes: multiple three-dimensional metal rings; each of the three-dimensional metal rings independently corresponds to a portion of the LED mesa disposed on the metal grid substrate to prevent light leakage between the corresponding LED mesa inside the three-dimensional metal ring and the corresponding LED mesa outside the three-dimensional metal ring; each of the three-dimensional metal rings is arranged in a skip-interval manner so that two diagonally opposite LED mesa in a 2×2 unit correspond to the three-dimensional metal rings respectively; each of the three-dimensional metal rings is disposed on the inorganic dielectric layer and the metal grid substrate; the inorganic dielectric layer is covered on the transparent resin corresponding to each of the three-dimensional metal rings.

12. The method for fabricating a Micro-LED microdisplay chip according to claim 11, characterized in that, The formation of the lower-level grid structure and the formation of the upper-level grid structure include: A metal grid substrate is formed around each of the LED platforms, having a plurality of the grid holes and a height not less than that of each of the LED platforms; Spin-coat a transparent resin and fill it to a level higher than the metal grid substrate; An inorganic dielectric material is deposited on the transparent resin; Photoresist dots are formed on the inorganic dielectric material corresponding to a portion of the LED platform; Sputter non-silver metal so that the thickness of the non-silver metal on the upper surface of the photoresist spot is greater than the thickness of the non-silver metal on the side of the photoresist spot and the upper surface of the inorganic dielectric material; Vertical etching removes the non-silver metal on the upper surface of the photoresist residue, and removes the non-silver metal, inorganic dielectric material, and transparent resin at the corresponding positions of the remaining LED mesa, so as to expose part of the metal grid substrate and form an inorganic dielectric layer and a metal interlayer. Oxygen plasma removes the photoresist residue; Sputtering silver metal; Vertical etching removes the silver metal from the inorganic dielectric layer, the metal interlayer, and the upper surface of the transparent resin, forming an inner metal layer and an outer metal layer, thereby obtaining the three-dimensional metal ring.

13. The method for fabricating a Micro-LED microdisplay chip according to claim 12, characterized in that, The photoresist spots are set in a skipped interval manner so that the two diagonally opposite LED platforms in the 2×2 unit correspond to the photoresist spots respectively.

14. The method for fabricating a Micro-LED microdisplay chip according to claim 11, characterized in that, It also includes the following steps: A color conversion structure is formed, the color conversion structure including a plurality of color conversion units, the plurality of color conversion units filling the areas not surrounded by each of the three-dimensional metal rings and within each of the three-dimensional metal rings.

15. The method for fabricating a Micro-LED microdisplay chip according to claim 14, characterized in that, The color conversion structure includes: The first form: fill the area not enclosed by each of the three-dimensional metal rings with a first color conversion unit, and fill the part of the three-dimensional metal rings with a second color conversion unit; Alternatively, in the second form, a first color conversion unit is filled within a portion of the three-dimensional metal rings, and a second color conversion unit is filled in the areas not enclosed by each of the three-dimensional metal rings. Alternatively, a third form may be used: filling a portion of the three-dimensional metal rings with a first color conversion unit and filling the remaining three-dimensional metal rings with a second color conversion unit.

16. The method for fabricating a Micro-LED microdisplay chip according to claim 15, characterized in that, The color conversion structure further includes: In the first and second forms, a third color conversion unit is filled within the remaining portion of the three-dimensional metal ring; Alternatively, in the third form, a third color conversion unit is filled in the area not enclosed by each of the three-dimensional metal rings.

17. The method for fabricating a Micro-LED microdisplay chip according to claim 15, characterized in that, The color conversion unit further includes: In the first and second forms, the remaining portion of the three-dimensional metal ring is filled with transparent resin units; Alternatively, in a third form, transparent resin units are filled in the areas not enclosed by the three-dimensional metal rings.

Images