Micro LED micro display chip and manufacturing method thereof

Abstract

The application provides a Micro LED micro display chip and a manufacturing method thereof, comprising a driving panel, a plurality of LED units, a transmissive reflective layer and a wavelength conversion layer arranged in sequence, the transmissive reflective layer is close to the side surface of the fence structure and comprises a plurality of transmissive reflective areas corresponding to the plurality of grid holes respectively, and the reflectivity of the transmissive reflective layer to first color light incident from any point on the edge of the transmissive reflective area is greater than or equal to 95%, so that the transmissive reflective layer can substantially not transmit the first color light incident from the edge of the transmissive reflective area, thereby effectively inhibiting or avoiding the first color light generated by the LED unit from propagating to the color conversion unit, the light transmission unit or the pixel point corresponding to the adjacent LED unit, and inhibiting or avoiding the transverse light stringing phenomenon in the wavelength conversion layer.

Description

Technical Field

[0001] This invention relates to the field of LED display technology, and more particularly to Micro LED microdisplay chips and their manufacturing methods. Background Technology

[0002] The emergence of Micro LED display technology has made it possible to miniaturize and achieve high resolution in display devices such as augmented reality (AR) displays, virtual reality (VR) displays, near-eye displays (NEDs), and head-up displays (HUDs).

[0003] When LEDs in a Micro LED microdisplay chip emit light, some of the emitted light illuminates neighboring pixels, causing optical crosstalk between adjacent pixels. This negatively impacts the resolution, color purity, and color gamut of the Micro LED display. Simultaneously, the heat generated by the LEDs during operation accelerates the aging of the wavelength conversion materials, resulting in a shorter lifespan for the Micro LED microdisplay chip. To overcome these shortcomings, existing Micro LED microdisplay chips space the wavelength conversion units and LED units within each pixel to suppress heat conduction from the LED units to the wavelength conversion units, thus slowing down the aging of the wavelength conversion materials. Furthermore, light-blocking structures are placed between adjacent LED units and between adjacent wavelength conversion units. For example, light-blocking structures can be placed separately between adjacent LED units and between adjacent wavelength conversion units, or an integrated light-blocking structure can be placed between adjacent LED units and their corresponding adjacent wavelength conversion units to suppress light propagation between neighboring pixels and overcome optical crosstalk between different pixels.

[0004] However, setting up light-blocking structures between wavelength conversion units and LED units increases the manufacturing steps and / or structural complexity of microdisplays, making the fabrication process of microdisplays more complex and increasing manufacturing costs. Furthermore, Micro LED microdisplay chips have high requirements for manufacturing precision, which leads to a decrease in product yield. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, this invention provides a Micro LED microdisplay chip and its manufacturing method.

[0006] In a first aspect, the present invention provides a Micro LED microdisplay chip, comprising:

[0007] Driver panel;

[0008] Multiple LED units are arranged on the driving panel. Each LED unit has an LED platform and can be driven individually by the driving panel. Each LED unit is used to generate a first color light.

[0009] A fence structure with multiple grid holes, wherein the multiple grid holes are respectively arranged around the multiple LED tabletops;

[0010] A wavelength conversion layer includes multiple wavelength conversion units, which are used to convert the wavelength of the first color light.

[0011] A transmissive-reflective layer is located between the fence structure and the wavelength conversion layer;

[0012] The side of the transmissive reflective layer near the fence structure includes multiple transmissive reflective areas corresponding to the multiple grid holes, and the transmissive reflective layer has a reflectivity of greater than or equal to 95% for first color light incident from any point on the edge of the transmissive reflective area.

[0013] Optionally, the transmission and reflection layer has a continuous layer structure.

[0014] Optionally, the LED unit includes a light-emitting layer. For any point A on the edge of the transmission and reflection area, the point P on the light-emitting layer corresponding to the transmission and reflection area that is closest to point A and point A are located on a straight line L. The angle between the straight line L and the normal of the transmission and reflection area is 20°-50°.

[0015] Optionally, the LED unit includes a light-emitting layer, and any point A on the edge of the transmission and reflection area has a horizontal distance d with the corresponding light-emitting layer. The horizontal distance d is the distance between the projection point of point A on the plane where the corresponding light-emitting layer is located and the corresponding light-emitting layer. The transmission and reflection area has a vertical distance h with the corresponding light-emitting layer area. h ≥ d / tanθ, where θ is the incident angle of the first color light when the reflectivity of the transmission and reflection layer for the first color light is 95%.

[0016] Optionally, the wavelength conversion unit has a color density greater than or equal to 1.2 for the first color light.

[0017] Optionally, the diameter of the LED unit is 0.1-10 μm, the diameter of the wavelength conversion unit is 0.6-10.5 μm, and the diameter of the wavelength conversion unit is 0.1-1 μm larger than the diameter of the corresponding LED unit.

[0018] Optionally, the fence structure includes a light-blocking substrate and a reflective layer, wherein a plurality of grid holes are formed in the light-blocking substrate, and at least the sidewalls of the grid holes are provided with a reflective layer.

[0019] Optionally, the thickness of the transmission and reflection layer is 0.6-3 μm, and the transmission and reflection layer includes multiple first material layers and multiple second material layers, with the first material layers and second material layers alternately arranged, and the refractive indices of the first material layers and the second material layers being different.

[0020] Optionally, the wavelength conversion layer is constructed as a layer structure formed by the continuous arrangement of the plurality of wavelength conversion units.

[0021] The wavelength conversion layer includes multiple wavelength conversion units and multiple light-transmitting units. The light-transmitting units are used to transmit the first color light generated by the corresponding LED unit. The wavelength conversion layer is constructed as a layer structure formed by the continuous arrangement of the multiple wavelength conversion units and the multiple light-transmitting units.

[0022] Secondly, the present invention provides a method for manufacturing a Micro LED microdisplay chip, the method comprising:

[0023] Provides a driver panel;

[0024] Multiple LED units are formed on the driving panel. Each LED unit has an LED platform and can be driven individually by the driving panel. The LED unit is used to generate a first color light.

[0025] A fence structure is formed; wherein the fence structure has multiple grid holes, and the multiple grid holes are respectively arranged around the multiple LED tabletops;

[0026] Forming a transmission and reflection layer;

[0027] A wavelength conversion layer is formed, the wavelength conversion layer including a plurality of wavelength conversion units, the wavelength conversion units being used to perform wavelength conversion on the first color light;

[0028] The transmissive reflective layer includes multiple transmissive reflective areas on the side near the fence structure, each corresponding to one of the multiple grid holes. The transmissive reflective layer has a reflectivity of greater than or equal to 95% for first-color light incident from any point on the edge of the transmissive reflective area.

[0029] Optionally, the fence structure includes a light-blocking substrate and a reflective layer, and forming the fence structure includes:

[0030] A light-blocking substrate material layer is formed on the plurality of LED units;

[0031] The light-blocking substrate material layer is etched to form a plurality of grid holes surrounding the plurality of LED platforms, thereby obtaining the light-blocking substrate;

[0032] A reflective material layer is formed on the plurality of LED surfaces and the light-blocking substrate;

[0033] The reflective material layer is etched to form the reflective layer at least on the sidewalls of the grid holes.

[0034] Optionally, forming the wavelength conversion layer includes:

[0035] A first light conversion material layer is formed on the transmission and reflection layer;

[0036] The first light conversion material layer is etched to obtain a first wavelength conversion unit, which is used to convert the first color light into the second color light.

[0037] A second light conversion material layer is formed on the transmission and reflection layer and the first wavelength conversion unit;

[0038] The second light conversion material layer is etched to obtain a second wavelength conversion unit, which is used to convert the first color light into a third color light.

[0039] The present invention has the following beneficial effects:

[0040] A Micro LED microdisplay chip is provided, comprising a driving panel, multiple LED units, a transmissive-reflective layer, and a wavelength conversion layer arranged sequentially. The transmissive-reflective layer includes multiple transmissive-reflective areas on the side near the grid structure, each corresponding to one of the multiple grid holes. The transmissive-reflective layer has a reflectivity of greater than or equal to 95% for first-color light incident from any point on the edge of the transmissive-reflective area. Therefore, the transmissive-reflective layer can essentially prevent the transmission of first-color light incident from the edge of the transmissive-reflective area, thereby effectively suppressing or preventing the propagation of first-color light generated by the LED unit to the color conversion unit, light-transmitting unit, or pixel corresponding to the adjacent LED unit. This suppresses or prevents lateral crosstalk in the wavelength conversion layer, thereby eliminating the need for a light-blocking structure in the wavelength conversion layer, simplifying the structure and manufacturing steps of the Micro LED microdisplay chip, reducing its manufacturing cost, and improving product yield. Furthermore, by eliminating the light-blocking structure in the wavelength conversion layer, the area of ​​the wavelength conversion unit can be increased, improving the wavelength conversion efficiency of the wavelength conversion unit. Attached Figure Description

[0041] To more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a cross-sectional structural diagram of a Micro LED microdisplay chip provided according to the present invention;

[0043] Figure 2 This is a partial structural cross-sectional schematic diagram of the Micro LED microdisplay chip provided according to the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] It should be noted that in the description of this invention, the terms "on," "above," "over," and "above" 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."

[0046] Furthermore, for ease of description, the present invention may also use spatial relative terms such as “below,” “under,” “under,” “above,” “on,” “upper,” “lower,” and “upper” to describe the relationship of one element or component to another element or component shown in the accompanying drawings. In addition to the orientations described in the figures, 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 (rotated 90° or otherwise), and the spatial relative descriptive terms used in the present invention can be interpreted accordingly.

[0047] As used in this invention, the term "layer" refers to a portion of material comprising a region of a certain thickness. A layer may extend over the entire lower or upper structure, or it may extend over a localized area of ​​the lower or upper structure. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure, with a thickness less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically, and / or along a conical surface.

[0048] like Figure 1-2 As shown, the present invention provides a Micro LED microdisplay chip, including a driving panel 1, multiple LED units 2, a fence structure 3, a wavelength conversion layer 4, and a transmission and reflection layer 5.

[0049] The driving panel 1 may include a substrate, a driving circuit, and multiple contacts connected to the driving circuit. The substrate is provided with the driving circuit and multiple contacts. The driving circuit may be a CMOS device or a TFT device. The contacts include a first contact 11 and a second contact 12.

[0050] For example, the first contact 11 is set as the cathode and the second contact 12 is set as the anode. The first contact 11 is located between adjacent LED units 2, and the second contact 12 is located below the corresponding LED unit 2 and electrically connected to the corresponding LED unit 2. The driving circuit provides a first voltage to the corresponding LED unit 2 through the first contact 11 and a second voltage to the corresponding LED unit 2 through the second contact 12.

[0051] Micro LED microdisplay chips can adopt a common cathode structure, a common anode structure, or be independent. Optionally, the first contact 11 is a common electrode and the Micro LED microdisplay chip has a common cathode structure; or, the second contact 12 is a common electrode and the Micro LED microdisplay chip has a common anode structure.

[0052] For example, the substrate material may include at least one of semiconductor materials and non-conductive materials. The semiconductor material may include at least one of silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, and indium phosphide, and the non-conductive material may include at least one of glass, plastic, and sapphire wafer. The driving circuit includes, but is not limited to, complementary metal-oxide-semiconductor (CMOS) devices or thin-film transistor (TFT) devices. For example, the driving panel 1 may be a CMOS silicon substrate, a thin-film transistor (TFT) glass substrate, or a thin-film field-effect transistor substrate, etc.

[0053] Multiple LED units 2 are disposed on one side of the driving panel 1, preferably arranged in an array on one side of the driving panel 1. Each LED unit 2 can be driven individually by the driving panel 1, which controls the LED unit 2 to either not produce a first color light or to produce the first color light in a desired emission manner. The first color light can be visible or invisible light; for example, it can be any one of red, green, blue, yellow, and ultraviolet light, or it can be other colors of light.

[0054] LED unit 2 can be a micro light-emitting diode or a micro organic light-emitting diode. Optionally, the micro light-emitting diode is formed based on an inorganic semiconductor material, which includes at least one of gallium nitride, aluminum gallium nitride, gallium arsenide, and aluminum gallium indium phosphide. The micro organic light-emitting diode is formed based on an organic material, which can be at least one of small molecule materials, polymer materials, and phosphorescent materials.

[0055] LED unit 2 has an LED platform, which can be a truncated cone structure or a cylindrical structure. The truncated cone structure is preferred, and the cylindrical structure is preferred to be circular. The sidewalls of the truncated cone LED platform can be inclined, with an obtuse angle between the sidewall and its top surface to improve the light-gathering effect of LED unit 2. The sidewalls of the cylindrical LED platform are substantially perpendicular to its top surface.

[0056] In an optional embodiment, the LED unit 2 includes a light-emitting layer 21, which is a layer structure capable of generating light of a specific wavelength. The light-emitting layer 21 may include a single quantum well structure or a multiple quantum well (MQW) structure, and may also include alternating well layers and barrier layers.

[0057] In an optional example, LED unit 2 includes a first doped semiconductor layer, a light-emitting layer 21, and a second doped semiconductor layer stacked sequentially. The light-emitting layer 21 generates 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 first doped semiconductor layer can be a p-type GaN or InGaN layer formed by doping or ion implantation, and can be a multilayer structure. The second doped semiconductor layer can be an n-type GaN or InGaN layer formed by doping or ion implantation, and can be a multilayer structure.

[0058] Optionally, the LED unit 2 further includes a first electrode layer and a second electrode layer. The first doped semiconductor layer is connected to the corresponding first contact 11 through the first electrode layer. Alternatively, a bonding layer may be included between the first electrode layer and the first doped semiconductor layer, and the first doped semiconductor layer is connected to the corresponding first contact 11 in sequence through the bonding layer and the first electrode layer. The second doped semiconductor layer is connected to the corresponding second contact 12 through the second electrode.

[0059] The materials of the first and second electrodes may include metallic materials or metal alloys, for example, at least one of indium tin oxide, chromium, platinum, gold, aluminum, germanium, tin, indium, copper and titanium.

[0060] The microdisplay chip includes a fence structure 3, which blocks the propagation of light between adjacent LED units 2. In an example where a transmissive reflective layer 5 is disposed above the fence structure 3, the fence structure 3 can block the light (i.e., the first color light) generated by the LED unit 2 from propagating to adjacent LED units 2 or adjacent pixels in the space below the transmissive reflective layer 5. The "above" and "below" refer to opposite directions. The "above" direction is from the side surface of the driving panel 1 where the LED unit 2 is located, away from the driving panel 1, for example, along the normal of the side surface from the side surface toward the wavelength conversion layer 4 or the transmissive reflective layer 5. In the production and practical application of this Micro LED microdisplay chip, the "above" and "below" directions will change as the position of the microdisplay chip changes.

[0061] In an optional embodiment, the fence structure 3 has a plurality of grid holes 31, which are respectively arranged around the plurality of LED platforms, that is, the LED platforms are arranged in the grid holes 31.

[0062] Optionally, the fence structure 3 includes a light-blocking substrate 32. The material of the light-blocking substrate 32 may include a light-blocking material. The light-blocking material is a material with a light absorption rate greater than a preset threshold or is opaque. The light-blocking material may be an organic resin. The organic resin may include at least one of organic black matrix photoresist, color filter photoresist, and polyimide.

[0063] The light-blocking substrate 32 has a plurality of grid holes 31 formed therein, and the grid holes 31 surround the corresponding LED platform to block the propagation of light between adjacent LED units 2.

[0064] Optionally, the fence structure 3 further includes a reflective layer 33, which is at least disposed on the sidewall of the grid hole 31. Optionally, the reflective layer 33 is disposed on the sidewall of the grid hole 31 and the top surface of the light-blocking substrate 32.

[0065] The reflective layer 33 can be made of organic or inorganic materials. The organic material can be a highly reflective organic coating, and the inorganic material can be a metallic material, such as aluminum, copper, or silver. Preferably, the reflective layer 33 is made of a thermally conductive material, such as a material with a thermal conductivity higher than a preset thermal conductivity threshold. Thus, the reflective layer 33 can reflect the first color light and allow it to propagate laterally directly across the LED unit 2, suppressing and avoiding light crosstalk between adjacent LED units 2. At the same time, the reflective layer 33 also serves to conduct and dissipate heat, suppressing the heat generated by the LED unit 2 from being conducted to the wavelength conversion layer 4.

[0066] Optionally, the grid hole 31 is a platform structure or a cylindrical structure. Optionally, the diameter of the grid hole in the platform structure gradually increases in the direction away from the drive panel 1. Optionally, the sidewall of the grid hole in the cylindrical structure is substantially perpendicular to the top surface of the grid hole.

[0067] In a preferred embodiment, in order to improve the uniformity of the first color light emitted by the LED unit 2, the LED unit 2 is basically disposed in the central region of the grid hole 31.

[0068] The wavelength conversion layer 4 of the Micro LED microdisplay chip includes multiple wavelength conversion units, which are used to convert the wavelength of the first color light. The wavelength conversion units are correspondingly arranged with the LED units 2, and the wavelength conversion units convert the first color light generated by the corresponding LED units 2 into preset emitted light.

[0069] The transmissive-reflective layer 5 of the Micro LED microdisplay chip is located between the fence structure 3 and the wavelength conversion layer 4. This transmissive-reflective layer 5 transmits a first color light and reflects other colors of light. Specifically, the plurality of LED units 2 and the fence structure 3 are located on one side of the transmissive-reflective layer 5, and the wavelength conversion layer 4 is located on the other side of the transmissive-reflective layer 5. The transmissive-reflective layer 5 can transmit the first color light generated by the LED unit 2. The first color light generated by the LED unit 2 is transmitted through the transmissive-reflective layer 5 into the corresponding wavelength conversion unit. The wavelength conversion unit converts the first color light into a preset color light, and the transmissive-reflective layer 5 can reflect the preset color light, thereby increasing the brightness of the preset color light emitted from the wavelength conversion unit. This improves the color saturation that the Micro LED microdisplay chip can display and expands the color gamut of the Micro LED microdisplay chip.

[0070] The side of the transmissive reflective layer 5 near the fence structure 3 includes multiple transmissive reflective areas 51 corresponding to the multiple grid holes 31. Specifically, the side of the transmissive reflective layer 5 near the fence structure 3 is the transmissive incident side 50. The first color light generated by the LED unit 2 enters the transmissive reflective layer 5 from this transmissive incident side 50. Part of the transmissive incident side 50 is blocked by the fence structure 3, so that the first color light generated by the LED unit 2 cannot propagate to the blocked part of the transmissive incident side 50.

[0071] The portion of the transmission incident side 50 corresponding to the grid hole 31 is not obstructed. The first color light generated by the LED unit 2 can propagate to the transmission incident side 50 that is not obstructed by the grid structure 3. The region of the transmission incident side 50 corresponding to the grid hole 31 constitutes a transmission reflection region 51. The transmission incident side 50 includes multiple transmission reflection regions 51, which correspond to multiple grid holes 31 respectively. The transmission reflection region 51 is the incident area of ​​the first color light generated by the LED unit 2 on the transmission incident side 50. The transmission reflection region 51 is the area on the transmission incident side 50 enclosed by its edge. Its edge can be the projection of the top sidewall contour of the grid hole 31 corresponding to the transmission reflection region 51 onto the transmission incident side 50. The transmission reflection region 51 can be the projection area of ​​the cross section corresponding to the top of the grid hole 31 onto the transmission incident side 50.

[0072] The transmission and reflection layer 5 has a high transmittance for the first color light incident from the central region of the transmission and reflection area 51. For example, the transmittance of the transmission and reflection layer 5 for the first color light incident from the central region of the transmission and reflection area 51 is greater than or equal to 98%, such as 98.5%, 99%, 99.5%, or about 100%.

[0073] The reflectivity of the transmission-reflection layer 5 for the first color light incident from any point on the edge of the transmission-reflection region 51 is greater than or equal to 95%, preferably greater than or equal to 97%, for example 98%, 99%, 99.5% or 100%.

[0074] Therefore, the transmission and reflection layer 5 does not transmit or only transmits a very small amount of the first color light incident from the edge or edge region of the transmission and reflection area 51. The first color light incident from the edge or edge region of the transmission and reflection area 51 can not pass through the transmission and reflection layer 5, or only a very small amount of the first color light passes through the transmission and reflection layer 5. This can effectively suppress or avoid the propagation of the first color light generated by the LED unit 2 to the color conversion unit or pixel corresponding to the adjacent LED unit 2. This can effectively suppress or avoid the lateral crosstalk phenomenon in the wavelength conversion layer 4, and thus eliminate the light-blocking structure provided in the wavelength conversion layer 4, such as the fence structure 3 provided in the wavelength conversion layer 4, simplifying the structure and manufacturing steps of the Micro LED micro-display chip, thereby reducing its manufacturing cost and improving product yield. In addition, by eliminating the light-blocking structure in the wavelength conversion layer 4, the area of ​​the wavelength conversion unit can be increased, and the wavelength conversion efficiency of the wavelength conversion unit can be improved.

[0075] Optionally, the reflectivity of the transmission and reflection layer 5 for first-color light incident from any point in the edge region of the transmission and reflection area 51 is greater than or equal to 95%, preferably greater than or equal to 97%, for example greater than or equal to 98%, greater than or equal to 99%, or about 100%. The edge region of the transmission and reflection area 51 is the region in the transmission and reflection area 51 whose distance from the edge of the transmission and reflection area 51 is less than or equal to a preset threshold, for example, the preset threshold is 2%, 3%, 5%, 8%, or 10% of the diameter of the transmission and reflection area 51.

[0076] In an optional embodiment, the transmissive and reflective layer 5 is a continuous layer structure, thereby simplifying the structure and manufacturing steps of the MicroLED microdisplay chip.

[0077] Optionally, the transmission and reflection layer 5 is composed of alternating layers of a first material layer having a first refractive index and a second material layer having a second refractive index, wherein the first refractive index and the second refractive index are different.

[0078] Optionally, the first material layer has a first thickness, and the second material layer has a second thickness, wherein the first thickness and the second thickness are the same or different.

[0079] Optionally, the number of first material layers in the transmission and reflection layer 5 is the same as the number of first material layers.

[0080] Optionally, the number of first material layers in the transmission and reflection layer 5 is 3-15, preferably 5-12, such as 8 or 10 layers. The number of second material layers in the transmission and reflection layer 5 is 3-15, preferably 5-12, such as 8 or 10 layers.

[0081] Optionally, the thickness of the transmission and reflection layer 5 is 0.6-3 μm, preferably 0.8-2.5 μm, such as 1 μm, 1.2 μm, 1.5 μm, 1.8 μm or 2 μm.

[0082] Optionally, both the first and second material layers can be made of inorganic materials. For example, the first material layer can be made of TiO2, SiO2, MgF2, or ZrO2, and the second material layer can be made of TiO2, SiO2, MgF2, or ZrO2. The materials used for the first and second material layers are not limited to the examples described above. The transmission and reflection layer 5, including both the first and second material layers, has low thermal conductivity, reducing heat transfer between the LED unit 2 and the wavelength conversion layer 4, and delaying the aging of the wavelength conversion layer 4.

[0083] Optionally, the first material layer and the second material layer are formed by means of thermal evaporation, sputtering or reactive ion deposition.

[0084] Optionally, the transmission and reflection layer 5 is configured as a distributed Bragg mirror (DBR).

[0085] By adjusting the refractive index, thickness, number, and refractive index difference between the first and second material layers of the transmission-reflection layer 5, the transmission and refraction characteristics of the transmission-reflection layer 5 for the first color light are adjusted. Optionally, the transmission-reflection layer 5 is configured such that its reflectivity for the first color light is not less than a preset reflection threshold when the incident angle of the first color light is 20°-50°, and the preset reflection threshold can be 95%, 98%, 99%, or 99.5%.

[0086] In an optional embodiment, for any point A on the edge of the transmission reflection area 51, the point P on the light-emitting layer 21 corresponding to the transmission reflection area 51 that is closest to point A and point A are located on a straight line L. The angle between the straight line L and the normal N of the transmission reflection area 51 is 20°-50°, preferably 22°-45°, especially 25°-40°, for example 28°, 30°, 32°, 35° or 42°.

[0087] In an optional embodiment, the transmissive reflective layer 5 is configured such that its reflectivity to the first color light changes with the incident angle of the first color light, at least within a preset incident angle range. In an optional embodiment, the LED unit 2 includes a light-emitting layer 21. Any point A on the edge of the transmissive reflective region 51 has a horizontal distance d with the corresponding light-emitting layer 21. The horizontal distance d is the distance between the projection of point A onto the plane of the corresponding light-emitting layer 21 and the corresponding light-emitting layer 21. The transmissive reflective layer has a vertical distance h with the corresponding light-emitting layer 21; h ≥ d / tanθ, where θ is the incident angle of the first color light when the reflectivity of the transmissive reflective layer 5 for the first color light is 95%. The corresponding light-emitting layer 21 is the light-emitting layer 21 corresponding to the transmissive reflective region 51, and is the light-emitting layer 21 in the LED unit 2 corresponding to the transmissive reflective region 51. This LED unit 2 is the LED unit 2 below the transmissive reflective region 51, and the first color light it generates is incident on the transmissive reflective layer 5 from the transmissive reflective region 51.

[0088] Therefore, excluding the first color light reflected by the reflective layer 33 of the fence structure 3, the incident angle of the first color light propagating from the light-emitting layer 21 of the LED unit 2 toward the corresponding transmission and reflection area 51 at any point A on the edge of the transmission and reflection area 51 is greater than or equal to θ, so that the reflectivity of the transmission and reflection layer 5 for the first color light incident from any point A on the edge of the transmission and reflection area 51 is greater than or equal to 95%, which can effectively suppress or prevent the first color light generated by the LED unit 2 from propagating to adjacent wavelength conversion units or pixels.

[0089] In one optional embodiment, the diameter of the LED unit 2 is 0.1-10 μm.

[0090] Optionally, the diameter of the wavelength conversion unit is 0.6-10.5um, and the diameter of the wavelength conversion unit is 0.1-1.5um larger than the diameter of the corresponding LED unit 2, preferably 0.2-1.2um larger, for example, 0.5um, 0.8um or 1um larger.

[0091] Optionally, the thickness of the wavelength conversion unit is 2-8 μm, such as 3 μm, 5 μm or 6 μm.

[0092] In an optional embodiment, the wavelength conversion unit has a color density of 1.2 or greater for the first color light. Specifically, the wavelength conversion unit includes a wavelength conversion material, which can be a quantum dot or a phosphor. By adjusting the amount of wavelength conversion material per unit volume and the thickness of the wavelength conversion unit, the color density of the wavelength conversion unit for the first color light can be adjusted. Therefore, by adjusting the color density of the wavelength conversion unit for the first color light, the lateral propagation of the first color light in the wavelength conversion monolayer is further suppressed, thus suppressing lateral crosstalk in the wavelength conversion monolayer.

[0093] Optionally, the wavelength conversion unit has a color density of 1.2 or greater for the first color light. Preferably, the wavelength conversion unit has a color density of 1.5 or greater, 1.8 or greater, 3 or greater, or 5 or greater for the first color light. In a specific example, the wavelength conversion unit has a color density of 2 for the first color light, and correspondingly, the wavelength conversion unit has an absorption rate of 99% or greater for the first color light.

[0094] In an optional embodiment, the wavelength conversion layer 4 includes multiple wavelength conversion units and multiple light-transmitting units (not shown). The light-transmitting units are used to transmit the first color light generated by the corresponding LED unit 2. The wavelength conversion layer 4 is constructed as a layer structure formed by the multiple wavelength conversion units and the multiple light-transmitting units arranged continuously. Any two adjacent wavelength conversion units are arranged continuously without gaps, and any adjacent wavelength conversion units and light-transmitting units are arranged continuously without gaps.

[0095] For example, the wavelength conversion layer 4 includes a first wavelength conversion unit 41 and a second wavelength conversion unit 42. For some LED units 2, no corresponding wavelength conversion unit is provided. The first color light generated by these LED units 2 is used as one of the primary colors for display. The wavelength conversion layer 4 includes a light-transmitting unit corresponding to these LED units 2. The first color light generated by these LED units 2 passes through the corresponding light-transmitting unit in the wavelength conversion layer 4. The first wavelength conversion unit 41 is used to convert the first color light generated by the corresponding LED unit 2 into a second color light, and the second wavelength conversion unit 42 is used to convert the first color light generated by the corresponding LED unit 2 into a third color light. The first wavelength conversion unit 41, the second wavelength conversion unit 42, and the light-transmitting unit are arranged continuously on the transmission and reflection layer 5.

[0096] In an alternative embodiment, the wavelength conversion layer 4 is constructed as a layer structure formed by a continuous arrangement of the plurality of wavelength conversion units. Any two adjacent wavelength conversion units are arranged continuously without gaps.

[0097] For example, the wavelength conversion layer 4 includes a first wavelength conversion unit 41, a second wavelength conversion unit 42, and a third wavelength conversion unit 43. The first wavelength conversion unit 41 is used to convert the first color light generated by the corresponding LED unit 2 into a second color light, the second wavelength conversion unit 42 is used to convert the first color light generated by the corresponding LED unit 2 into a third color light, and the third wavelength conversion unit 43 is used to convert the first color light generated by the corresponding LED unit 2 into a fourth color light. The first wavelength conversion unit 41, the second wavelength conversion unit 42, and the third wavelength conversion unit 43 are arranged continuously on the transmission and reflection layer 5.

[0098] This disclosure effectively suppresses or prevents the propagation of the first color light generated by the LED unit to the color conversion unit, light transmission unit, or pixel corresponding to the adjacent LED unit by setting a transmission and reflection layer that basically does not transmit the first color light incident from the edge of the transmission and reflection area. This eliminates the need for light-blocking structures set between two adjacent wavelength conversion units and / or between adjacent wavelength conversion units and light transmission units, allowing two adjacent wavelength conversion units to be set without gaps and continuously, and adjacent wavelength conversion units and light transmission units to be set without gaps and continuously, thereby increasing the area of ​​the wavelength conversion unit and improving the conversion efficiency of the wavelength conversion unit.

[0099] In an optional embodiment, the Micro LED microdisplay chip includes a recessed cavity located in the grid aperture 31, the recessed cavity being at least between the grid aperture 31 and the LED unit 2, and a filler 6 is provided in the recessed cavity, the filler 6 being made of an organic resin material. Preferably, the filler is flush with the grid structure 3.

[0100] Optionally, the thermal conductivity of the organic resin material is lower than a preset thermal conductivity threshold, thereby giving the filler a low thermal conductivity and suppressing the transfer of heat from the LED unit 2 to the wavelength conversion layer 4.

[0101] Optionally, the organic resin material includes at least one of MMA, PMMA, epoxy resin, styrene, and polyurethane.

[0102] In an optional embodiment, the wavelength conversion layer 4 is provided with an isolation layer 7, which is used to isolate external gases and liquids, such as oxygen and water, thereby protecting the wavelength conversion layer 4 from damage by external gases and liquids.

[0103] The material of the isolation layer 7 includes inorganic oxides, such as transparent inorganic oxides. For example, the inorganic oxide includes at least one of SiO2 and Al2O3. The isolation layer 7 can be formed on the wavelength conversion layer 4 by depositing the inorganic oxide.

[0104] The present invention also provides a method for manufacturing a Micro LED microdisplay chip, wherein the Micro LED microdisplay chip may be the Micro LED microdisplay chip described above, and the manufacturing method includes:

[0105] Step S1, provide driver panel 1;

[0106] Step S2: A plurality of LED units 2 are formed on the driving panel 1. Each LED unit 2 has an LED platform and can be driven individually by the driving panel 1. Each LED unit 2 is used to generate a first color light.

[0107] Step S3, forming a fence structure 3; wherein, the fence structure 3 has a plurality of grid holes 31, and the plurality of grid holes 31 are respectively arranged around the plurality of LED surfaces;

[0108] Step S4: Form the transmission and reflection layer 5;

[0109] Step S5: A wavelength conversion layer 4 is formed, the wavelength conversion layer 4 including a plurality of wavelength conversion units, the wavelength conversion units being used to perform wavelength conversion on the first color light;

[0110] The transmissive reflective layer 5 includes a plurality of transmissive reflective areas 51 corresponding to the plurality of grid holes 31 on the side near the fence structure 3. The transmissive reflective layer 5 has a reflectivity of greater than or equal to 95% for first color light incident from any point on the edge of the transmissive reflective area 51.

[0111] In an optional embodiment, the fence structure 3 includes a light-blocking substrate 32 and a reflective layer 33, and forming the fence structure 3 includes:

[0112] Step S11: A light-blocking substrate material layer is formed on the plurality of LED units 2;

[0113] Step S12: Etch the light-blocking substrate material layer to form a plurality of grid holes 31 surrounding the plurality of LED mesa surfaces, thereby obtaining the light-blocking substrate 32;

[0114] Step S13: A reflective material layer is formed on the plurality of LED platforms and the light-blocking substrate 32;

[0115] Step S14: Etch the reflective material layer to form the reflective layer 33 at least on the sidewall of the grid hole 31.

[0116] In an optional implementation, the formation of the wavelength conversion layer 4 includes:

[0117] Step S21: A first light conversion material layer is formed on the transmission and reflection layer 5;

[0118] Step S22: Etch the first light conversion material layer to obtain a first wavelength conversion unit 41. The first wavelength conversion unit 41 is used to convert the first color light into the second color light.

[0119] Step S23: A second light conversion material layer is formed on the transmission and reflection layer 5 and the first wavelength conversion unit 41;

[0120] Step S24: Etch the second light conversion material layer to obtain a second wavelength conversion unit 42, which is used to convert the first color light into a third color light.

[0121] The above-disclosed embodiments are merely a few preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A Micro LED microdisplay chip, comprising: Driver panel (1); Multiple LED units (2) are arranged on the driving panel (1). Each LED unit (2) has an LED platform and can be driven individually by the driving panel (1). Each LED unit (2) is used to generate a first color light. A fence structure (3) having multiple grid holes (31), the multiple grid holes (31) being respectively arranged around the multiple LED platforms; The wavelength conversion layer (4) includes multiple wavelength conversion units (41, 42, 43), which are used to convert the wavelength of the first color light; A transmission and reflection layer (5) is located between the fence structure (3) and the wavelength conversion layer (4); The characteristic feature is that the side of the transmission and reflection layer (5) near the fence structure (3) includes a plurality of transmission and reflection areas (51) corresponding to the plurality of grid holes (31) respectively, and the transmission and reflection layer (5) has a reflectivity of greater than or equal to 95% for first color light incident from any point on the edge of the transmission and reflection area (51); The wavelength conversion layer (4) is constructed as a layer structure formed by the continuous arrangement of the plurality of wavelength conversion units; or, the wavelength conversion layer (4) includes a plurality of wavelength conversion units and a plurality of light-transmitting units, wherein the light-transmitting units are used to transmit the first color light generated by the corresponding LED unit, and the wavelength conversion layer (4) is constructed as a layer structure formed by the continuous arrangement of the plurality of wavelength conversion units and the plurality of light-transmitting units.

2. The Micro LED microdisplay chip according to claim 1, characterized in that, The transmission and reflection layer (5) is a continuous layer structure.

3. The Micro LED microdisplay chip according to claim 1, characterized in that, The LED unit (2) includes a light-emitting layer (21). For any point A on the edge of the transmission and reflection area (51), the point P on the light-emitting layer (21) corresponding to the transmission and reflection area (51) that is closest to point A and point A are located on a straight line L. The angle between the straight line L and the normal of the transmission and reflection area (51) is 20°-50°.

4. The Micro LED microdisplay chip according to any one of claims 1 to 3, characterized in that, The LED unit (2) includes a light-emitting layer (21). Any point A on the edge of the transmission and reflection area (51) has a horizontal distance d with the corresponding light-emitting layer (21). The horizontal distance d is the distance between the projection point of point A on the plane where the corresponding light-emitting layer (21) is located and the corresponding light-emitting layer (21). The transmission and reflection area has a vertical distance h with the corresponding light-emitting layer (21). h≥d / tanθ, where θ is the incident angle of the first color light when the reflectivity of the transmission and reflection layer (5) for the first color light is 95%.

5. The Micro LED microdisplay chip according to any one of claims 1 to 3, characterized in that, The wavelength conversion units (41, 42, 43) have a color density greater than or equal to 1.2 for the first color light.

6. The Micro LED microdisplay chip according to any one of claims 1 to 3, characterized in that, The diameter of the LED unit (2) is 0.1-10 μm, and the diameter of the wavelength conversion unit (41, 42, 43) is 0.6-10.5 μm. The diameter of the wavelength conversion unit is 0.1-1 μm larger than the diameter of the corresponding LED unit.

7. The Micro LED microdisplay chip according to any one of claims 1 to 3, characterized in that, The fence structure (3) includes a light-blocking substrate (32) and a reflective layer (33). A plurality of grid holes (31) are formed in the light-blocking substrate (32), and the reflective layer (33) is provided on the sidewall of at least the grid hole (31).

8. The Micro LED microdisplay chip according to claim 1 or 2, characterized in that, The thickness of the transmission and reflection layer (5) is 0.6-3 μm. The transmission and reflection layer (5) includes multiple first material layers and multiple second material layers. The first material layers and the second material layers are alternately arranged. The refractive index of the first material layer and the refractive index of the second material layer are different.

9. A method for manufacturing a Micro LED microdisplay chip, characterized in that, The manufacturing method includes: Provide driver panel (1); Multiple LED units (2) are formed on the driving panel (1). Each LED unit (2) has an LED platform. Each LED unit (2) can be driven individually by the driving panel (1). Each LED unit (2) is used to generate a first color light. A fence structure (3) is formed; wherein the fence structure (3) has a plurality of grid holes (31), and the plurality of grid holes (31) are respectively arranged around the plurality of LED surfaces; Forming a transmission and reflection layer (5); A wavelength conversion layer (4) is formed, the wavelength conversion layer (4) includes a plurality of wavelength conversion units (41, 42, 43), the wavelength conversion units (41, 42, 43) are used to perform wavelength conversion on the first color light; The transmissive reflective layer (5) near the side of the fence structure (3) includes multiple transmissive reflective areas (51) corresponding to the multiple grid holes (31), and the transmissive reflective layer (5) has a reflectivity of greater than or equal to 95% for first color light incident from any point on the edge of the transmissive reflective area (51); The wavelength conversion layer (4) is constructed as a layer structure formed by the continuous arrangement of the plurality of wavelength conversion units; or, the wavelength conversion layer (4) includes a plurality of wavelength conversion units and a plurality of light-transmitting units, wherein the light-transmitting units are used to transmit the first color light generated by the corresponding LED unit, and the wavelength conversion layer (4) is constructed as a layer structure formed by the continuous arrangement of the plurality of wavelength conversion units and the plurality of light-transmitting units.

10. The manufacturing method according to claim 9, characterized in that, The fence structure (3) includes a light-blocking substrate (32) and a reflective layer (33), and the formation of the fence structure (3) includes: A light-blocking substrate material layer is formed on the plurality of LED units (2); The light-blocking substrate material layer is etched to form a plurality of grid holes (31) surrounding the plurality of LED platforms, thereby obtaining the light-blocking substrate (32). A reflective material layer is formed on the plurality of LED platforms and the light-blocking substrate (32); The reflective material layer is etched to form the reflective layer (33) at least on the sidewall of the grid hole (31).

11. The method for manufacturing a Micro LED microdisplay chip according to claim 9, characterized in that, The wavelength conversion layer (4) includes: A first light conversion material layer is formed on the transmission and reflection layer (5); The first light conversion material layer is etched to obtain a first wavelength conversion unit (41), which is used to convert the first color light into the second color light. A second light conversion material layer is formed on the transmission and reflection layer (5) and the first wavelength conversion unit; The second light conversion material layer is etched to obtain a second wavelength conversion unit (42), which is used to convert the first color light into the third color light.

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