Micro-LED micro display chip and preparation method thereof

Abstract

The invention discloses a Micro-LED micro display chip and a preparation method thereof, and relates to the technical field of micro display. The chip comprises a driving panel; a plurality of LED units; the wavelength conversion layer at least comprises a plurality of first wavelength conversion units, and the first wavelength conversion units are arranged above the light emitting surfaces of the LED units; the first wavelength conversion unit is provided with a first curved surface, and the first wavelength conversion unit is used for converting the first color light emitted by the LED unit into second color light and gathering the second color light. In the embodiment of the invention, the wavelength conversion layer in the Micro-LED micro-display chip has two functions at the same time, specifically, the wavelength conversion layer has the function of converting the first color light emitted by the LED unit into the light of other colors and also has the function of gathering the converted color light, so that the display brightness of the Micro-LED micro-display chip is improved, and the brightness of the micro-LED micro-display chip is improved. In addition, the thickness of the Micro-LED micro display chip can be thinner, and the preparation process is simpler.

Description

Technical Field

[0001] The present invention relates to the field of micro-display technology, and in particular to a Micro-LED micro-display chip and a preparation method thereof. Background Art

[0002] Micro-LED, also known as micro light-emitting diode, refers to a high-density integrated LED array. The distance between LED pixels in the array is in the order of 0.1-100 microns, and each LED pixel can emit light by itself. At present, Micro-LED micro display chips are widely used in various cutting-edge fields such as augmented reality (AR), near-eye display (NED) and wearable display due to their small size, long life, fast response speed and low power consumption.

[0003] The current display brightness of Micro-LED micro-display chips is poor, which limits their application in high-demand display fields. Therefore, how to improve the display brightness of Micro-LED micro-display chips has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0004] The present application provides a Micro-LED micro display chip and a method for preparing the same, the main purpose of the method being to solve the technical problem of low color brightness of the Micro-LED display.

[0005] According to a first aspect of the present invention, there is provided a Micro-LED micro display chip, comprising:

[0006] Driver panel;

[0007] A plurality of LED units are arranged on the driving panel, a light emitting surface is provided on a side of the LED unit away from the driving panel, and the LED unit emits a first color light;

[0008] A wavelength conversion layer, the wavelength conversion layer includes at least a plurality of first wavelength conversion units, the first wavelength conversion unit includes a first curved surface and a first connecting surface located below the first curved surface, the edge of the first connecting surface is connected to the edge of the first curved surface, the first connecting surface is arranged above the light emitting surface of at least part of the LED unit, and the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light.

[0009] According to a second aspect of the present invention, there is provided a method for preparing a Micro-LED micro display chip, comprising:

[0010] Providing a drive panel;

[0011] A plurality of LED units are formed on the driving panel, a light emitting surface is arranged on a side of the LED unit away from the driving panel, and the LED unit emits a first color light;

[0012] A wavelength conversion layer is formed, wherein the wavelength conversion layer includes at least a plurality of first wavelength conversion units, wherein the first wavelength conversion unit includes a first curved surface and a first connecting surface, wherein an edge of the first connecting surface is connected to an edge of the first curved surface, and the first connecting surface is arranged above a light emitting surface of at least a portion of the LED unit, and the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light.

[0013] In the above embodiment, a Micro-LED micro-display chip and a preparation method thereof are provided, which relate to the field of micro-display technology. The chip includes: a driving panel; a plurality of LED units arranged on the driving panel, each of the LED units can be driven individually by the driving panel, the side of the LED unit away from the driving panel is a light-emitting surface, and the LED unit emits a first color light; a wavelength conversion layer, the wavelength conversion layer includes at least a plurality of first wavelength conversion units, the first wavelength conversion unit includes a first curved surface and a first connecting surface located below the first curved surface, the edge of the first connecting surface is connected to the edge of the first curved surface, the first connecting surface is arranged above the light-emitting surface of at least part of the LED unit, and the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light. In the embodiment of the present application, the wavelength conversion layer in the Micro-LED micro-display chip has two functions at the same time, specifically including the function of converting the first color light emitted by the LED unit into the second color light, and also including the function of gathering the converted color light, so that while improving the display brightness of the Micro-LED micro-display chip, the thickness of the Micro-LED micro-display chip can also be made thinner, and the preparation process is simpler.

[0014] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic cross-sectional structure diagram of a Micro-LED micro display chip provided by an embodiment of the present invention is shown;

[0016] Figure 2 A schematic cross-sectional structure diagram of another Micro-LED micro display chip provided by an embodiment of the present invention is shown;

[0017] Figure 3 A schematic cross-sectional structure diagram of another Micro-LED micro display chip provided by an embodiment of the present invention is shown;

[0018] Figure 4 A schematic diagram showing a reflection curve and spectrum of an HBR structure provided on the lower surface of a wavelength conversion unit provided by an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of a process for preparing a Micro-LED micro display chip provided by an embodiment of the present invention is shown;

[0020] Figure 6 A schematic cross-sectional structure diagram of a driving panel and a plurality of LED units provided in an embodiment of the present invention is shown;

[0021] Figure 7 Shown in Figure 6 A schematic cross-sectional structure diagram of a plurality of LED units filled with transparent material;

[0022] Figure 8 Shown in Figure 7 A schematic cross-sectional structure diagram of forming a transflective material on the plane where the upper surface of the transparent material and the LED unit are located and forming a mask on the transflective material;

[0023] Fig. 9 Shown in Figure 8 The structure shown is a schematic diagram of a cross-sectional structure after the structure is dry-etched throughout the entire layer;

[0024] Fig.10 Shows the Fig. 9 A schematic cross-sectional structure diagram of a first etching stop layer being evaporated on the upper surface and side wall of the transmissive reflective unit, the side wall of the planarization structure, and the upper surface of the driving panel;

[0025] Fig.11 Shown in Fig.10 A schematic cross-sectional structure diagram of a reflective material formed on the first etch stop layer shown;

[0026] Fig.12 Shows the Fig.11 The schematic diagram of the cross-sectional structure of forming a reflective layer by dry etching the entire layer of the reflective material is shown;

[0027] Fig.13 Shown in Fig.12 A schematic cross-sectional structure diagram of a groove formed by multiple reflective layers filled with transparent material;

[0028] Fig.14 Shown in Fig.13 A schematic cross-sectional structure diagram of spin coating a first wavelength conversion material on the upper surfaces of the second planarization layer and the first etch stop layer is shown;

[0029] Fig.15 Shown in Fig.14 A schematic cross-sectional structure diagram of forming an etching mask on the first wavelength conversion material is shown;

[0030] Fig.16 Shows the Fig.15 The cross-sectional structure diagram of the etching mask reflowing to form the lens structure mask shown;

[0031] Fig.17 Shows the Fig.16 The first wavelength conversion material shown is patterned and etched to form a cross-sectional structural schematic diagram of a first wavelength conversion unit;

[0032] Fig.18 Shown in Fig.17 A schematic cross-sectional structure diagram showing that a second wavelength conversion material is spin-coated on the upper surface of the structure and an etching mask is formed on the second wavelength conversion material;

[0033] Fig.19 Shows the Fig.18 The cross-sectional structure diagram of the etching mask reflowing to form the lens structure mask shown;

[0034] Fig. 20 Shows the Fig.19 The second wavelength conversion material shown is patterned and etched to form a cross-sectional structural schematic diagram of a second wavelength conversion unit;

[0035] Fig.21 Shows the Fig. 20 A schematic cross-sectional structure diagram of spin coating a third wavelength conversion material on the upper surface of the structure shown, and forming an etching mask on the third wavelength conversion material;

[0036] Fig. 22 Shows the Fig.21 The cross-sectional structure diagram of the etching mask reflowing to form the lens structure mask shown;

[0037] Fig.23 Shows the Fig. 22 The third wavelength conversion material shown is patterned and etched to form a cross-sectional structural schematic diagram of a third wavelength conversion unit;

[0038] Fig.24 Shown in Fig.23 A schematic cross-sectional structure diagram of a structure shown in FIG. 1 with a first filter material sprayed on the structure;

[0039] Fig.25 Shows the Fig.24 The first filter material is photolithographically patterned to form a cross-sectional structural schematic diagram of a first filter unit;

[0040] Fig.26 Shows the Fig.25 A schematic cross-sectional structure diagram of spraying a second filter material on the structure shown;

[0041] Fig. 27 Shows the Fig.26 The cross-sectional structure diagram of the second filter material being photolithographically patterned to form a second filter unit and spraying a third filter material is shown. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0043] It should be noted that, in the description of the present application, the meaning of the terms "on", "above", "above", and "above" should be interpreted in the broadest sense, meaning that the description containing these terms is interpreted as "the component can be set on another component in direct contact, or there can be an intermediate component or layer between the components". In addition, for the convenience of description, the present application may also use spatial relative terms such as "under", "below", "under", "on", "above", "above", "lower", "upper", etc. to describe the relationship between an element or component and another element or component shown in the drawings. In addition to the orientations described in the figures, the spatial relative terms are also intended to cover different orientations of the device in use or operation. The device can be oriented in other ways (rotated 90° or in other orientations), and the spatial relative descriptors used in the present application can be interpreted accordingly.

[0044] The term "layer" as used in this application refers to a portion of a material that includes an area having a certain thickness. A layer may extend over the entire underlying or superstructure, or may extend over a localized area of ​​the underlying or superstructure. In addition, a layer may be an area of ​​a homogeneous or inhomogeneous continuous structure whose thickness is less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically and / or along a tapered surface.

[0045] The current display brightness of Micro-LED micro-display chips is poor, which limits their application in high-demand display fields. Therefore, how to improve the display brightness of Micro-LED micro-display chips has become a technical problem that technicians in this field need to solve urgently.

[0046] In view of the above problems, the Micro-LED micro display chip in the embodiment of the present application includes:

[0047] Driver panel;

[0048] A plurality of LED units are arranged on a driving panel, each of the LED units can be driven individually by the driving panel, a light emitting surface is provided on a side of the LED unit away from the driving panel, and the LED unit emits a first color light;

[0049] A wavelength conversion layer, the wavelength conversion layer includes at least a plurality of first wavelength conversion units, the first wavelength conversion unit includes a first curved surface and a first connecting surface located below the first curved surface, the edge of the first connecting surface is connected to the edge of the first curved surface, and the first connecting surface is arranged above the light emitting surface of at least part of the LED unit; the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light.

[0050] In the embodiment of the present application, the wavelength conversion layer has two functions at the same time, specifically including the function of converting the first color light emitted by the LED unit into the second color light, and also including the function of gathering the converted color light. In this way, while improving the display brightness of the Micro-LED micro display chip, it can also make the thickness of the Micro-LED micro display chip thinner and the preparation process simpler.

[0051] Figures 1 to 3 A possible cross-sectional structure diagram of a Micro LED micro display chip is provided. Figure 1 As shown, the Micro LED micro display chip may include a driving panel 101 , a plurality of LED units 102 and a wavelength conversion layer 108 .

[0052] Among them, multiple LED units 102 can be arranged on the driving panel 101 in a regular or irregular manner. As pixels of the Micro-LED micro display chip, the size of the LED unit 102 is 0.1-10 microns. In a preferred embodiment, the size of the LED unit 102 is less than 5 microns.

[0053] In some embodiments, the LED unit 102 may be a micro light emitting diode or a micro organic light emitting diode, wherein the micro light emitting diode is formed based on an inorganic semiconductor material, for example, the inorganic semiconductor material may be gallium nitride, aluminum gallium nitrogen, gallium arsenide, aluminum gallium indium phosphide, etc., and the micro organic light emitting diode is formed based on an organic material, for example, the organic material may be a small molecule, a polymer, a phosphorescent material, etc.

[0054] In the embodiment of the present application, the color of the first color light emitted by the LED unit 102 includes but is not limited to: any one of red light, green light, blue light, yellow light or ultraviolet light.

[0055] In the embodiment of the present application, the design of the first curved surface 10811 can make the first wavelength conversion unit 1081 have the effect of gathering light. The first connecting surface can be a plane, such as Figure 1 As shown, it may not be a plane. For example, the first connection surface may cover the corresponding LED unit, and in this case, the first connection surface is not a plane.

[0056] In some embodiments, the orthographic projection of the first wavelength conversion unit may completely overlap with the orthographic projection of the corresponding LED unit, or the LED unit is located within the orthographic projection of the first wavelength conversion unit.

[0057] In some embodiments, the wavelength conversion layer also includes a plurality of second wavelength conversion units; the second wavelength conversion unit includes a second curved surface and a second connecting surface located below the second curved surface, the edge of the second connecting surface is connected to the edge of the second curved surface, the second connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the second wavelength conversion unit is used to convert the first color light emitted by the LED unit into a third color light and gather the third color light.

[0058] The wavelength conversion layer also includes a plurality of third wavelength conversion units; the third wavelength conversion unit includes a third curved surface and a third connecting surface located below the third curved surface, the edge of the third connecting surface is connected to the edge of the third curved surface, the third connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the third wavelength conversion unit is used to convert the first color light emitted by the LED unit into a fourth color light and gather the fourth color light.

[0059] The second curved surface and the third curved surface also have the effect of gathering light. The second connecting surface and the third connecting surface, like the first connecting surface, can be set to be a plane or a non-plane.

[0060] In some embodiments, the second color light, the third color light and the fourth color light are all different and correspond arbitrarily to RGB (red, green, blue), thereby obtaining a color Micro-LED micro display chip.

[0061] Exemplarily, the first color light is ultraviolet light, and the second color light is red light. The first wavelength conversion unit 1081 converts the ultraviolet light emitted by the LED unit 102 into red light, and gathers the red light, so that the brightness of the red light can be improved; the first color light emitted by the LED unit 102 is ultraviolet light, and the third color light is green light. The second wavelength conversion unit 1082 converts the ultraviolet light emitted by the LED unit 102 into green light, and gathers the green light, so that the brightness of the green light can be improved; the first color light emitted by the LED unit 102 is ultraviolet light, and the fourth color light is blue light. The third wavelength conversion unit 1083 converts the ultraviolet light emitted by the LED unit 102 into blue light, and gathers the blue light, so that the brightness of the blue light can be improved.

[0062] See also Figure 1 ,exist Figure 1 The wavelength conversion layer 108 includes a first wavelength conversion unit 1081, a second wavelength conversion unit 1082 and a third wavelength conversion unit 1083. It should be noted that due to Figure 1 The size limit is Figure 1 Only one first wavelength conversion unit 1081 , one second wavelength conversion unit 1082 and one third wavelength conversion unit 1083 are shown. In fact, the Micro-LED micro display chip includes multiple first wavelength conversion units 1081 , multiple second wavelength conversion units 1082 and multiple third wavelength conversion units 1083 .

[0063] In some embodiments, the second wavelength conversion unit and the third wavelength conversion unit may be the same as the first wavelength conversion unit, and the orthographic projection may completely overlap with the orthographic projection of the corresponding LED unit 102, or the LED unit is located within the orthographic projection.

[0064] In the embodiment of the present application, the first wavelength conversion unit 1081, the second wavelength conversion unit 1082 and the third wavelength conversion unit 1083 can have two functions at the same time, one of which is to convert the first color light emitted by the LED unit 102 into other color lights, and the other is to gather the converted color light. In this way, while improving the display brightness, since the first wavelength conversion unit 1081, the second wavelength conversion unit 1082 and the third wavelength conversion unit 1083 all have two functions at the same time, there is no need to use two components with separate functions, such as a component with a conversion function and another component with a light gathering function, so that the thickness of the Micro-LED micro display chip is thinner and the preparation process is simpler.

[0065] In some embodiments, when the first color light emitted by the LED unit 102 and the color light converted by the wavelength conversion unit (including the first wavelength conversion unit 1081, the second wavelength conversion unit 1082 and the third wavelength conversion unit 1083) are the same color, the wavelength conversion unit may not be set above the light emitting surface of the LED unit 102.

[0066] Exemplarily, the first color light emitted by the LED unit 102 is blue light, and the fourth color light converted by the third wavelength conversion unit 1083 is blue light. In this case, the third wavelength conversion unit 1083 may not be set, and only the first connecting surface of the first wavelength conversion unit 1081 and the second connecting surface of the second wavelength conversion unit 1082 may be set above the light emitting surface of the LED unit 102.

[0067] In some embodiments, the wavelength conversion layer also includes a plurality of transparent units; the transparent unit includes a fourth curved surface and a fourth connecting surface located below the fourth curved surface, the edge of the fourth connecting surface is connected to the edge of the fourth curved surface, the fourth connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the transparent unit allows the first color light emitted by the LED unit to pass through and gathers the first color light.

[0068] In this way, if the first color light emitted by the LED unit 102 is the same color as the color light converted by the wavelength conversion unit, a transparent unit can be directly arranged on the light-emitting surface of the LED unit 102. The transparent unit can enhance the brightness of the first color light emitted by the LED unit 102 without the wavelength conversion unit arranged above the light-emitting surface. The transparent unit only has the function of gathering the first color light, and does not have the function of converting the first color light into other color lights. In some embodiments, the transparent unit can have the same shape as the wavelength conversion unit. Exemplarily, the first color light emitted by the LED unit 102 is blue light, and the color light converted by the wavelength conversion unit is also blue light. In this case, the wavelength conversion unit can be arranged on the light-emitting surface of the LED unit 102 without the wavelength conversion unit arranged. The transparent unit can be arranged directly.

[0069] In some embodiments, the material of the wavelength conversion layer 108 includes wavelength conversion particles and photoresist. The wavelength conversion particles may be, for example, phosphors and / or quantum dots, etc., and the present embodiment does not specifically limit this. For example, the quantum dots may be colloidal quantum dots. The photoresist in the present embodiment includes, but is not limited to, Overcoat glue, SU8 (near-ultraviolet negative photoresist), benzocyclobutene (BCB), etc., and may also be SiO 2 , Al 2 O 3 , Si 3 N 4The phosphor can be yttrium aluminum garnet, cerium phosphor, (oxy) nitride phosphor, silicate phosphor and Mn 4+ Activated fluoride phosphors, etc. The quantum dots may include one or more combinations of CdSe, CdS, CdZnSe, CdZnS, CdZnSeS, ZnSeS, ZnSe, CuInS, CuInSe, InP, InZnP, and perovskite quantum dots, etc., and the present application does not impose specific restrictions on this.

[0070] In some embodiments, the material of the first wavelength conversion unit 1081 includes photoresist, quantum dots and / or phosphor; the material of the second wavelength conversion unit 1082 includes photoresist, quantum dots and / or phosphor; the material of the third wavelength conversion unit 1083 includes photoresist, quantum dots and / or phosphor.

[0071] In some embodiments, the Micro-LED micro display chip further includes a filter layer, which includes a plurality of first filter units 1094 , and the first filter units 1094 cover the first curved surface 10811 ; the first filter units 1094 allow the second color light to pass through and filter out other color lights.

[0072] In the embodiment of the present application, in order to prevent the first wavelength conversion unit 1081 from being unable to completely convert the first color light into the second color light, a first filter unit 1094 is provided on the first curved surface 10811 of the first wavelength conversion unit 1081, so that the first filter unit 1094 is highly selective, and only allows the second color light to pass smoothly, while efficiently filtering out all other color lights other than the second color light. In some embodiments, the first filter unit is a curved structure, and the first filter unit can further gather the second color light. In one example, the LED unit 102 emits blue light, and the first wavelength conversion unit 1081 converts the blue light into red light. The first filter unit 1094 only allows red light to pass through and filters out color lights other than red light. The purpose of such a design is to ensure that the red light emitted in the Micro-LED micro display chip is purer, and to achieve accurate screening of light and optimize the display effect.

[0073] In some embodiments, the filter layer further includes a plurality of second filter units 1096 , and the second filter units 1096 cover the second curved surface of the second wavelength conversion unit 1082 ; the second filter units 1096 allow the third color light to pass through, and filter out color light other than the third color light.

[0074] In one example, the LED unit 102 emits blue light, the second wavelength conversion unit 1082 converts the blue light into green light, and the second filter unit 1096 only allows green light to pass through and filters out light of colors other than green light. The purpose of this design is to ensure that the green light emitted from the Micro-LED micro display chip is purer, to achieve precise screening of light and optimize the display effect.

[0075] In some embodiments, the filter layer further includes a plurality of third filter units 1098, wherein the third filter units 1098 cover the third curved surface of the third wavelength conversion unit 1083, and the third filter units 1098 allow the fourth color light to pass through and filter out color light other than the fourth color light.

[0076] In one example, the LED unit 102 emits ultraviolet light, the third wavelength conversion unit 1083 converts the ultraviolet light into blue light, and the third filter unit 1098 only allows blue light to pass through and filters out color light other than blue light. The purpose of this design is to ensure that the blue light emitted from the Micro-LED micro display chip is purer, to achieve precise screening of light and optimize the display effect.

[0077] In some embodiments, the materials of the first filter unit 1094, the second filter unit 1096 and the third filter unit 1098 include but are not limited to organic color filter photoresist, Bragg distributed reflector, etc.

[0078] In the embodiment of the present application, the first filter unit 1094, the second filter unit 1096 and the third filter unit 1098 allow different colors of light to pass through, and correspond to RGB (red, green, blue) at will. In this embodiment, by preparing R / G / B three-color color filter (Color Filter, CF) graphics on the Micro-LED micro-display chip, not only the color separation effect is enhanced, but also the color reproduction ability and display quality of the Micro-LED micro-display chip are improved.

[0079] In some embodiments, the Micro-LED micro display chip further includes a first etch stop layer 1112 ; the first etch stop layer 1112 is disposed on the surface of the LED unit 102 and on the upper surface of the driving panel 101 .

[0080] Etching technology is used in the process of preparing the Micro-LED micro display chip. In order to better protect the LED unit 102 and the driving panel 101 in the Micro-LED micro display chip, a first etching stop layer 1112 is provided in the embodiment of the present application.

[0081] In some embodiments, the first etch stop layer 1112 should have sufficient transparency, and generally can be made of silicon dioxide, silicon nitride, aluminum oxide and the like. It should be noted that the first etch stop layer 1112 is a continuous film structure. In some embodiments, the thickness of the first etch stop layer 1112 can be, for example, 300 to 800 nm. Of course, the thickness of the first etch stop layer 1112 can also be selected according to specific circumstances.

[0082] In some embodiments, Figure 3 As shown, the Micro-LED micro display chip further includes a transmissive reflective layer 1132, which is disposed between the light emitting surface of the LED unit and the wavelength conversion layer. The transmissive reflective layer is used to transmit the first color light and reflect other color lights.

[0083] In some embodiments, the transflective layer has a preset thickness, so that the focus of the first curved surface is located below the transflective layer.

[0084] In the embodiment of the present application, the transmissive reflective layer can be regarded as a light source. When the light source is located within the focal length of the first curved surface, even if the intensity of the light source is low, an amplified virtual image of sufficient brightness can be obtained through the first wavelength conversion unit, and ultimately a high-intensity light source is obtained, thereby improving the brightness of the second light displayed by the Micro-LED micro display chip.

[0085] In some embodiments, the transflective layer is a continuous structure.

[0086] In some embodiments, the transmissive reflective layer 1132 includes a plurality of transmissive reflective units 1131 ; each transmissive reflective unit 1131 is correspondingly disposed below the light emitting surface and the first connecting surface of an LED unit 102 , and the transmissive reflective unit 1131 is used to transmit the first color light and reflect other color lights.

[0087] Exemplarily, the LED unit 102 emits a first color light (e.g., blue light), and the first wavelength conversion unit converts the first color light into a second color light (e.g., red light) and gathers the second color light. The transmissive reflective unit is located between the light emitting surface of the LED unit 102 and the first wavelength conversion unit 1081, and is used to transmit the first color light (e.g., blue light) emitted by the LED unit 102, and reflect the second color light (e.g., red light) converted by the first wavelength conversion unit 1081, which can effectively reduce the interface light loss between the LED unit 102 and the wavelength conversion layer 108, and improve the light energy utilization efficiency.

[0088] In some embodiments, the transflective layer includes a distributed Bragg reflector and / or a high refractive index mirror.

[0089] Specifically, this embodiment can use a distributed Bragg reflector (DBR) and / or a high refractive index reflector (HBR) to prepare a transmissive reflective layer. The distributed Bragg reflector (DBR) is based on the Bragg scattering principle and is prepared by alternating two materials with different refractive indices. The thickness of each layer is precisely set to 1 / 4n wavelength, where n refers to the refractive index of the material of the layer. The reflection performance of the DBR is mainly subject to factors such as the number of alternating layers, the difference in refractive index between layers, and the layer boundary conditions. It can achieve precise reflection for specific wavelengths and allow other wavelengths to pass through.

[0090] Furthermore, the high refractive index reflector (HBR) can be made of a more complex combination of multiple materials and multiple thicknesses, and can be optimized through simulation software, and different refractive index materials can be selected for irregular alternating superposition. Among them, HBR can achieve higher reflection of the corresponding wavelength while achieving higher transmission of other wavelengths.

[0091] This embodiment uses a distributed Bragg reflector (DBR) and / or a high refractive index reflector (HBR) to prepare a transmissive reflective layer, which can take into account both preparation cost and performance optimization. On the one hand, the DBR structure is easy to manufacture and cost-controlled, and is suitable for large-scale production environments; on the other hand, the HBR structure has good flexibility and efficiency, and is suitable for use in quantum dot structure designs that require extremely high light conversion efficiency, to ensure that the color purity and brightness performance of the Micro-LED microdisplay chip are maximized. Through the above dual design, a balance between optical performance and cost can be achieved in different application scenarios.

[0092] In some embodiments, the high refractive index reflector can be composed of a plurality of materials with different refractive indices and thicknesses alternatingly fitted by simulation software, wherein the number of groups of alternating film layers composed of materials with different refractive indices alternatingly is greater than five.

[0093] Specifically, the high refractive index reflector (HBR) can be made of a complex combination of multiple materials and multiple thicknesses, which can be optimized through simulation software simulation, and different refractive index materials are selected for irregular alternating superposition. Compared with the distributed Bragg reflector (DBR), the high refractive index reflector (HBR) can achieve a higher reflectivity wavelength range on the same device, while maintaining a high transmittance for other wavelengths. In order to achieve the ideal high reflectivity, the HBR structure usually requires at least five pairs of alternating film layers. Among them, alternating film layers refer to a group of film layers composed of multiple different materials alternating.

[0094] This embodiment provides a DBR / HBR structure on the lower surface of the wavelength conversion layer, and can utilize the gradual change characteristics from high refractive index to low refractive index in the DBR / HBR structure, and select a variety of materials with different refractive indices, so as to effectively reduce the interface light loss between the LED unit 102 and the wavelength conversion layer. In particular, in the HBR design, the blue light emitted by the bottom LED unit 102 can be fully transmitted, and at the same time, the converted light emitted downward by the wavelength conversion layer 108 will be reflected back to the upper surface, which greatly improves the overall light conversion efficiency of the film layer, thereby obtaining a color LED chip with higher brightness. In addition, through the DBR / HBR design, the blue light that the wavelength conversion layer 108 fails to absorb will be reflected back to the wavelength conversion layer 108 for absorption and conversion again. For green quantum dots with weaker absorption capacity, this secondary absorption and conversion mechanism significantly improves its light conversion effect, thereby enhancing the color purity and overall performance of the display chip.

[0095] Further, see Figure 4 By setting the HBR structure on the lower surface of the wavelength conversion layer, the HBR can adjust the reflection curve to a situation without a secondary peak, and the reflection curve is smoother. It can achieve higher reflection of the corresponding wavelength while having higher transmission of other wavelengths, thereby obtaining a brighter and purer conversion spectrum.

[0096] In some embodiments, Figure 2 As shown, the Micro-LED micro display chip also includes a first planarization layer, which includes a plurality of planarization structures 1101 . The planarization structures 1101 are arranged around the LED unit 102 , and the upper surface of the planarization structures 1101 is coplanar with the upper surface of the LED unit 102 .

[0097] In this way, the wavelength conversion layer 108 can be arranged on the plane formed by the upper surface of the LED unit 102 and the upper surface of the planarization structure 1101, so that the wavelength conversion layer 108 is more stably supported, improving the stability of the Micro-LED micro display chip, and at the same time, it is easier to complete the arrangement of the wavelength conversion layer 108 on the plane, and the process difficulty is lower. In the embodiment of the present application, the planarization structure 1101 can be made of any transparent material.

[0098] In some embodiments, the Micro-LED micro display chip further includes a reflective layer 114; the reflective layer 114 is disposed on the sidewall of the first etch stop layer.

[0099] In the embodiment of the present application, the reflective layer 114 can effectively prevent the LED units 102 from crosstalking with each other. At the same time, when the Micro-LED micro display chip is provided with a transmissive reflective unit 1131, it can also prevent the crosstalk between different transmissive reflective units.

[0100] The embodiment of the present application does not specifically limit the material of the reflective layer 114. In some embodiments, the reflective layer can be made of organic materials, and the optional organic materials include but are not limited to highly reflective organic coatings. The reflective layer can also be made of inorganic materials, and the optional inorganic materials include but are not limited to metal materials, such as Al, Cu, Ag, etc.

[0101] In some embodiments, the Micro-LED micro display chip further includes a second planarization layer 1102 ; the second planarization layer fills the trenches formed by the plurality of light reflecting layers 114 .

[0102] In the embodiment of the present application, the provision of the second planarization layer can improve the stability of the Micro-LED micro display chip.

[0103] In some embodiments, Figure 3 As shown, the Micro-LED micro display chip further includes a third planarization layer 1103; the third planarization layer 1103 is filled between the plurality of LED units 102, and the upper surface of the third planarization layer 1103 is coplanar with the upper surface of the LED unit 102. The third planarization layer 1103 is a continuous structure, and the third planarization layer 1103 can support the transmissive reflective layer 1132 disposed thereon more stably, thereby improving the stability of the Micro-LED micro display chip.

[0104] In some embodiments, the Micro-LED micro display chip further includes a second etch stop layer 1111 ; the second etch stop layer is disposed above a plane formed by an upper surface of the LED unit 102 and an upper surface of the third planarization layer 1103 .

[0105] Etching technology is used in the process of preparing the Micro-LED micro display chip. In order to better protect the LED unit 102 and the third planarization layer 1103 in the Micro-LED micro display chip, the embodiment of the present application sets a second etching stopper layer 1111 above the plane formed by the two. The optional material of the second etching stopper layer 1111 is the same as that of the first etching stopper layer 1112 described above, which will not be repeated here.

[0106] Figure 5 The flowchart of the method for manufacturing a Micro LED micro display chip provided by an embodiment of the present application is shown. Figure 5 As shown, the method 500 for manufacturing a Micro-LED micro display chip includes steps: S510-S530.

[0107] S510, providing a driving panel;

[0108] S520, forming a plurality of LED units on the driving panel, each of the LED units being capable of being driven individually by the driving panel, a side of the LED unit away from the driving panel being a light emitting surface, and the LED unit emitting light of a first color;

[0109] S530. Form a wavelength conversion layer, wherein the wavelength conversion layer includes at least a plurality of first wavelength conversion units, wherein the first wavelength conversion unit includes a first curved surface and a first connecting surface, wherein an edge of the first connecting surface is connected to an edge of the first curved surface, and the first connecting surface is disposed above a light emitting surface of at least a portion of the LED unit, and the first wavelength conversion unit is used for converting the first color light emitted by the LED unit into a second color light and gathering the second color light.

[0110] In some embodiments, the step of forming a wavelength conversion layer includes:

[0111] A first wavelength conversion material is formed above the LED unit. For example, the first wavelength conversion material may be formed above the LED unit by spin coating. Of course, other methods may also be used to form the first wavelength conversion material.

[0112] forming a first mask on the first wavelength conversion material located above a portion of the LED unit, and reflowing the first mask to obtain a first lens structure mask;

[0113] Based on the first lens structure mask, the first wavelength conversion material is dry-etched to form the first wavelength conversion unit; wherein the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into the second color light and gather the second color light.

[0114] In some embodiments, the step of forming the wavelength conversion layer further comprises:

[0115] A second wavelength conversion material is formed above the LED unit. For example, the second wavelength conversion material can be formed above the LED unit by spin coating. Of course, the second wavelength conversion material can also be formed by other methods.

[0116] Forming a second mask on the second wavelength conversion material located above the other part of the LED unit, and reflowing the second mask to obtain a second lens structure mask;

[0117] Based on the second lens structure mask, the second wavelength conversion material is dry-etched to form the second wavelength conversion unit; wherein the second wavelength conversion unit is used to convert the first color light emitted by the LED unit into a third color light and gather the third color light.

[0118] In some embodiments, the step of forming the wavelength conversion layer further comprises:

[0119] The third wavelength conversion material is formed above the LED unit. For example, the first wavelength conversion material can be formed above the LED unit by spin coating. Of course, the third wavelength conversion material can also be formed by other methods.

[0120] Forming a third mask on the third wavelength conversion material located above the other parts of the LED units, and reflowing the third mask to obtain a third lens structure mask;

[0121] Based on the third lens structure mask, the third wavelength conversion material is dry-etched to form the third wavelength conversion unit; wherein the third wavelength conversion unit is used to convert the first color light emitted by the LED unit into a fourth color light and gather the fourth color light.

[0122] In some embodiments, the step of forming the wavelength conversion layer further comprises:

[0123] forming a transparent material above the LED unit;

[0124] Forming a fourth mask on the transparent material located above the other parts of the LED units, and reflowing the fourth mask to obtain a transparent unit structure mask;

[0125] Based on the transparent unit structure mask, the transparent material is dry-etched to form the transparent unit.

[0126] In some embodiments, the preparation method further comprises:

[0127] A filter layer is formed, wherein the filter layer includes a plurality of first filter units, wherein the first filter units cover the first wavelength conversion units; the first filter units allow the second color light to pass through and filter out other color lights.

[0128] In some embodiments, the step of forming the filter layer includes:

[0129] A first filter material is formed on the wavelength conversion layer. Exemplarily, the first filter material is sprayed on the wavelength conversion layer. Of course, other methods can also be used to form the first filter material. The first filter material is patterned by photolithography to retain the first filter material on the first wavelength conversion unit to obtain the first filter unit.

[0130] In some embodiments, the step of forming the filter layer further comprises:

[0131] A second filter material is formed on the wavelength conversion layer. Exemplarily, the second filter material is sprayed on the wavelength conversion layer. Of course, other methods can also be used to form the second filter material. The second filter material is patterned by photolithography to retain the second filter material on the second wavelength conversion unit to obtain a second filter unit.

[0132] In some embodiments, the step of forming the filter layer further comprises:

[0133] A third filter material is formed on the wavelength conversion layer. Exemplarily, the third filter material is sprayed on the wavelength conversion layer. Of course, other methods can also be used to form the third filter material. The third filter material is patterned by photolithography to retain the third filter material on the third wavelength conversion unit to obtain a third filter unit.

[0134] In some embodiments, the preparation method further comprises:

[0135] A first planarization layer is formed. The first planarization layer includes a plurality of planarization structures. The planarization structures are arranged around the LED unit, and the upper surfaces of the planarization structures are coplanar with the upper surfaces of the LED unit.

[0136] Furthermore, the step of forming the first planarization layer includes: filling transparent material between the plurality of LED units; etching the transparent material to form a planarization structure; the planarization structure is arranged around the LED unit, and the upper surface of the planarization structure is coplanar with the upper surface of the LED unit. In the embodiment of the present application, the etching of the transparent material can be performed by dry etching or wet etching.

[0137] In some embodiments, the preparation method further comprises:

[0138] A first etch stop layer is formed; the first etch stop layer is arranged on the surface of the LED unit and on the upper surface of the driving panel.

[0139] Furthermore, a first etching stop layer may be formed on the surface of the LED unit and the upper surface of the driving panel by evaporation or the like.

[0140] In some embodiments, the preparation method further includes: before forming the wavelength conversion layer, forming a transmissive reflective layer on the light emitting surface of the LED unit.

[0141] In some embodiments, the forming of the transmissive reflective layer on the light emitting surface of the LED unit includes: forming a plurality of transmissive reflective units; each of the transmissive reflective units is correspondingly arranged on the light emitting surface of one of the LED units and is located below the first connecting surface, and the transmissive reflective unit is used to transmit the first color light and reflect other color lights. In the embodiment of the present application, the formation of the transmissive reflective unit can be performed by dry etching or wet etching.

[0142] Furthermore, after the transparent material is filled between the multiple LED units, the transflective material is spin-coated on the upper surface of the transparent material and the upper surface of the LED unit. A mask is formed on the transflective material and above the LED unit, and the transparent material and the transflective material are etched in a dry manner to form multiple transflective units.

[0143] Accordingly, the first etching stop layer may be formed on the upper surface and sidewall of the transflective unit, the sidewall of the planarization structure, and the upper surface of the driving panel by evaporation or the like.

[0144] In some embodiments, the preparation method further includes: forming a reflective layer on the sidewall of the first etch stop layer.

[0145] Further, the step of forming a reflective layer on the side wall of the first etch barrier layer includes: forming a reflective material on the first etch barrier layer. Specifically, the reflective material can be formed on the first etch barrier layer by evaporation or the like. The reflective material on the first connection surface is etched to form a reflective layer; the first connection surface is parallel to the upper surface of the LED unit. The reflective material can be etched by dry etching or wet etching. In one example, the reflective material can be etched by dry etching to form a reflective layer.

[0146] In some embodiments, the preparation method further includes: forming a second planarization layer; and filling the second planarization layer in the trenches formed by the plurality of light reflecting layers.

[0147] For the specific implementation process of each embodiment of the preparation method of the above-mentioned Micro-LED micro display chip, reference can be made to the embodiment of the Micro-LED micro display chip, and no further description is given here. It can be understood that the preparation process, specific structure and technical effect of the Micro-LED micro display chip prepared by the preparation method of the Micro-LED micro display chip of each embodiment above correspond to those of the Micro-LED micro display chip in the embodiments of the above-mentioned Micro-LED micro display chip.

[0148] In one embodiment, in order to better understand the preparation method of the Micro-LED micro display chip in the embodiment of the present application, the following is combined with Figure 6 to Figure 27 , the preparation method of Micro-LED micro display chip is introduced in detail. Figure 6 to Figure 27 The cross-sectional structure diagram of the Micro-LED micro display chip at different stages in the preparation process is exemplarily shown. It should be understood that for the contents not described in detail in this section, reference can be made to the description of some embodiments of the Micro LED micro display chip.

[0149] The following is a detailed introduction Figure 2A method for preparing a Micro LED micro display chip.

[0150] In some embodiments, reference Figure 6 First, a driving panel 101 is provided. The driving panel 101 may include a circuit layer composed of complementary metal oxide semiconductor (CMOS) devices or TFT devices. These CMOS devices or TFT devices may form a driving circuit in the driving panel 101. At the same time, the driving panel 101 may also include a plurality of contacts connected to the driving circuit, and a plurality of LED units 102 arranged on the driving panel 101 may be electrically connected to the plurality of contacts.

[0151] In some embodiments, reference Figure 6 The plurality of contacts include a first electrode contact 103 and a second electrode contact 104. The first electrode contact 103 can be electrically connected to each LED unit 102, and the second electrode contact 104 can be electrically connected to the plurality of LED units 102 to drive any LED unit 102 of the plurality of LED units 102 to emit light.

[0152] In some embodiments, reference Figure 6 The MESA pattern can be designed according to the patterned mask, and the LED epitaxial layer can be etched to form a plurality of LED units 102 with LED mesas, and the LED units 102 are functional step structures. It should be understood that etching includes dry or wet methods.

[0153] In some embodiments, reference Figure 6 , a plurality of first electrode layers 105 can be formed by etching the bonding layer, and the plurality of first electrode layers 105 are arranged one by one with the plurality of LED units 102. And adjacent LED units 102 cannot be electrically connected through the first electrode layer 105. The first electrode layer 105 is electrically connected to the first electrode contact 103, and the driving circuit in the driving panel 101 can apply an anode voltage to the LED unit 102 individually through the first electrode contact 103, and provide an individual driving signal, so as to achieve the purpose of individually controlling the light emission of each LED unit 102.

[0154] In some embodiments, reference Figure 6 , a passivation layer 106 may be deposited on the sidewall surface of the LED unit 102. The material of the passivation layer 106 may include an inorganic material or an organic material.

[0155] In some embodiments, reference Figure 6, a second electrode layer 107 may be provided between the LED units 102, and the second electrode layer 107 may be located on the upper portion of the driving panel 101 and outside the passivation layer 106. The second electrode layer 107 may connect the first semiconductor layers of the plurality of LED units 102, and the second electrode layer 107 is a common cathode electrode layer of the Micro LED micro display chip, and the second electrode contact 104 may be connected to the second electrode layer 107, so as to form a conductive loop with the first electrode contact 103 to drive the LED unit 102 to emit light.

[0156] In some embodiments, the selection of the LED unit 102 is not limited to a common anode structure, and may be a common cathode material, a vertical flip chip, or other structures.

[0157] Reference Figure 7 , a transparent material 1103 may be filled between the plurality of LED units 102. Specifically, the transparent material 1103 is filled between the plurality of LED units 102 so that the upper surface of the transparent material 1103 and the upper surface of the LED unit 102 are coplanar.

[0158] Reference Figure 8 A transflective material 1133 is formed on a plane formed by the upper surface of the transparent material 1103 and the upper surface of the LED unit 102 . For example, the transflective material 1133 may be formed by spin coating. A mask 1134 is formed on the transflective material 1133 .

[0159] Reference Fig. 9 , using dry whole-layer etching, the transparent material 1103 and the transmissive reflective material 1133 located below the mask 1134 are retained, and a planarization structure 1101 and a transmissive reflective unit 1131 are correspondingly formed.

[0160] Reference Fig.10 A first etching stopper layer 1112 is evaporated on the upper surface and side wall of the transmissive reflective unit 1131 , the side wall of the planarization structure 1101 , and the upper surface of the driving panel 101 .

[0161] Reference Fig.11 , a reflective material 1141 is formed on the first etch stop layer 1112 , and the reflective material 1141 is located on the upper surface of the first etch stop layer 1112 .

[0162] Reference Fig.12 , the reflective material 1141 parallel to the upper surface of the LED unit 102 is dry-etched throughout the layer to form a reflective layer 114 .

[0163] Reference Fig.13 , the trenches formed by the plurality of light reflecting layers 114 are filled with transparent material to obtain a second planarization layer 1102 .

[0164] Reference Fig.14 , a first wavelength conversion material 1084 is spin-coated on the upper surfaces of the second planarization layer 1102 and the first etch stop layer 1112 .

[0165] Reference Fig.15 , an etching mask 1085 is formed on the first wavelength conversion material 1084 .

[0166] Reference Fig.16 , the etching mask 1085 formed on the first wavelength conversion material 1084 is reflowed to obtain a lens structure mask 1086.

[0167] Reference Fig.17 Based on the lens structure mask 1086 , the first wavelength conversion material 1084 is patterned etched, such as dry full-layer etching, to form a first wavelength conversion unit 1081 .

[0168] Reference Fig.18 ,exist Fig.17 A second wavelength conversion material 1087 is spin-coated on the upper surface of the structure, and an etching mask 1088 is formed on the second wavelength conversion material.

[0169] Reference Fig.19 ,right Fig.18 The etching mask 1088 in the embodiment is reflowed to obtain a lens structure mask 1089.

[0170] Reference Fig. 20 Based on the lens structure mask 1089 , the second wavelength conversion material 1087 is patterned etched, such as dry full-layer etching, to form a second wavelength conversion unit 1082 .

[0171] Reference Fig.21 ,exist Fig. 20 A third wavelength conversion material 1090 is spin-coated on the upper surface of the structure, and an etching mask 1091 is formed on the third wavelength conversion material 1090 .

[0172] Reference Fig. 22 ,right Fig.21 The etching mask 1091 in the embodiment is reflowed to obtain a lens structure mask 1092.

[0173] Reference Fig.23 Based on the lens structure mask 1092 , the third wavelength conversion material 1090 is patterned etched, such as dry full-layer etching, to form a third wavelength conversion unit 1083 .

[0174] Reference Fig.24 ,exist Fig.23 A first filter material 1093 is sprayed on the upper surface of the structure.

[0175] Reference Fig.25, the first filter material 1093 is photolithographically patterned to retain the first filter material 1093 on the first wavelength conversion unit 1081, thereby obtaining the first filter unit 1094.

[0176] Reference Fig.26 ,exist Fig.25 The second filter material 1095 is sprayed on the upper surface of the middle structure.

[0177] Reference Fig. 27 , the second filter material 1095 is photolithographically patterned to retain the second filter material 1095 on the second wavelength conversion unit 1082 to obtain a second filter unit 1096, and the third filter material 1097 is continuously sprayed on the upper surface of the Micro-LED micro display chip provided with the first filter unit and the second filter unit.

[0178] Reference Figure 2 , the third filter material 1097 is photolithographically patterned to retain the third filter material 1097 on the third wavelength conversion unit 1083, thereby obtaining a third filter unit 1098.

[0179] It should be noted that the embodiments of the method for preparing the Micro-LED micro display chip in this application only describe the production process or steps. The device structure, shape, and materials not described can refer to the above-mentioned embodiments of the Micro LED micro display chip and will not be repeated here.

[0180] As another optional implementation of the disclosure of the present application, an embodiment of the present application further provides a display device, the display device includes a Micro-LED micro display chip, and the Micro-LED micro display chip can be a Micro-LED micro display chip provided in any of the above embodiments. The display device can be, for example, a component or device including a Micro-LED micro display chip, such as a Micro-LED micro display chip device including an encapsulation layer.

[0181] As another optional implementation of the disclosure of the present application, an embodiment of the present application further provides an electronic device. The electronic device may include, for example, a Micro-LED micro display chip or a display device. The Micro-LED micro display chip may be a Micro LED micro display chip provided in any of the above embodiments.

[0182] The electronic devices in the embodiments of the present application include, but are not limited to: display devices such as augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye displays (NED) and heads-up displays (HUD) devices.

[0183] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A Micro-LED micro display chip, characterized in that: include: Driver panel; A plurality of LED units are arranged on the driving panel, each of the LED units can be driven individually by the driving panel, a side of the LED unit away from the driving panel is a light emitting surface, and the LED unit emits a first color light; A wavelength conversion layer, the wavelength conversion layer includes at least a plurality of first wavelength conversion units, the first wavelength conversion unit includes a first curved surface and a first connecting surface located below the first curved surface, the edge of the first connecting surface is connected to the edge of the first curved surface, the first connecting surface is arranged above the light emitting surface of at least part of the LED unit, and the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light.

2. The Micro-LED micro display chip according to claim 1, characterized in that: It also includes a transmissive reflective layer; the transmissive reflective layer is arranged between the light emitting surface of the LED unit and the wavelength conversion layer.

3. The Micro-LED micro display chip according to claim 2, characterized in that: The transmissive reflective layer has a preset thickness, so that the focus of the first curved surface is located below the transmissive reflective layer.

4. The Micro-LED micro display chip according to claim 2, characterized in that: The transmissive reflective layer includes a plurality of transmissive reflective units; each of the transmissive reflective units is correspondingly arranged on the light emitting surface of one of the LED units and is located below the first connecting surface, and the transmissive reflective unit is used to transmit the first color light and reflect other color lights.

5. The Micro-LED micro display chip according to claim 1, characterized in that: The focal length of the first curved surface of the first wavelength conversion unit is 1-10 um.

6. The Micro-LED micro display chip according to claim 1, characterized in that: The wavelength conversion layer also includes a plurality of second wavelength conversion units; the second wavelength conversion unit includes a second curved surface and a second connecting surface located below the second curved surface, the edge of the second connecting surface is connected to the edge of the second curved surface, the second connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the second wavelength conversion unit is used to convert the first color light emitted by the LED unit into a third color light and gather the third color light.

7. The Micro-LED micro display chip according to claim 6, characterized in that: The wavelength conversion layer also includes a plurality of third wavelength conversion units; the third wavelength conversion unit includes a third curved surface and a third connecting surface located below the third curved surface, the edge of the third connecting surface is connected to the edge of the third curved surface, the third connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the third wavelength conversion unit is used to convert the first color light emitted by the LED unit into a fourth color light and gather the fourth color light.

8. The Micro-LED micro display chip according to claim 1, characterized in that: The wavelength conversion layer also includes a plurality of transparent units; the transparent unit includes a fourth curved surface and a fourth connecting surface located below the fourth curved surface, the edge of the fourth connecting surface is connected to the edge of the fourth curved surface, the fourth connecting surface is arranged above the light emitting surface of at least part of the other LED units, and the transparent unit allows the first color light emitted by the LED unit to pass through and gathers the first color light.

9. The Micro-LED micro display chip according to claim 1, characterized in that: It also includes a filter layer, which includes a plurality of first filter units. The first filter units cover the first curved surface. The first filter units allow the second color light to pass through and filter out other color lights.

10. A method for preparing a Micro-LED micro display chip, characterized in that: include: Providing a drive panel; A plurality of LED units are formed on the driving panel, each of the LED units can be driven individually by the driving panel, a side of the LED unit away from the driving panel is a light emitting surface, and the LED unit emits a first color light; A wavelength conversion layer is formed, wherein the wavelength conversion layer includes at least a plurality of first wavelength conversion units, wherein the first wavelength conversion unit includes a first curved surface and a first connecting surface, wherein an edge of the first connecting surface is connected to an edge of the first curved surface, and the first connecting surface is arranged above a light emitting surface of at least a portion of the LED unit, and the first wavelength conversion unit is used to convert the first color light emitted by the LED unit into a second color light and gather the second color light.

11. The method for preparing a Micro-LED micro display chip according to claim 10, characterized in that: The steps of forming a wavelength conversion layer include: forming a first wavelength conversion material above the LED unit; forming a first mask on the first wavelength conversion material located above a portion of the LED unit, and reflowing the first mask to obtain a first lens structure mask; Based on the first lens structure mask, the first wavelength conversion material is dry-etched to form the first wavelength conversion unit.

12. The method for preparing a Micro-LED micro display chip according to claim 10, further comprising: Before forming the wavelength conversion layer, a transmissive reflective layer is formed on the light emitting surface of the LED unit.

13. The method for preparing a Micro-LED micro display chip according to claim 12, characterized in that: The forming of a transmissive reflective layer on the light emitting surface of the LED unit comprises: A plurality of transmissive reflective units are formed; each of the transmissive reflective units is correspondingly arranged on the light emitting surface of one of the LED units and is located below the first connecting surface, and the transmissive reflective unit is used to transmit the first color light and reflect other color lights.

14. The method for preparing a Micro-LED micro display chip according to claim 13, characterized in that: The step of forming the wavelength conversion layer further includes: forming a second wavelength conversion material above the LED unit; Forming a second mask on the second wavelength conversion material located above the other part of the LED unit, and reflowing the second mask to obtain a second lens structure mask; Based on the second lens structure mask, the second wavelength conversion material is dry-etched to form the second wavelength conversion unit.

15. The method for preparing a Micro-LED micro display chip according to claim 14, characterized in that: The step of forming the wavelength conversion layer further includes: forming a third wavelength conversion material above the LED unit; Forming a third mask on the third wavelength conversion material located above the other parts of the LED units, and reflowing the third mask to obtain a third lens structure mask; Based on the third lens structure mask, the third wavelength conversion material is dry-etched to form the third wavelength conversion unit.

16. The method for preparing a Micro-LED micro display chip according to claim 14, characterized in that: The step of forming the wavelength conversion layer further includes: forming a transparent material above the LED unit; Forming a fourth mask on the transparent material located above the other parts of the LED units, and reflowing the fourth mask to obtain a transparent unit structure mask; Based on the transparent unit structure mask, the transparent material is dry-etched to form the transparent unit.

17. The method for preparing a Micro-LED micro display chip according to claim 10, characterized in that: Also includes: A filter layer is formed, wherein the filter layer includes a plurality of first filter units, wherein the first filter units cover the first wavelength conversion units; the first filter units allow the second color light to pass through and filter out other color lights.

18. The method for preparing a Micro-LED micro display chip according to claim 17, characterized in that: The step of forming the filter layer comprises: forming a first filter material on the wavelength conversion layer; The first filter material is patterned by photolithography to retain the first filter material on the first wavelength conversion unit, thereby obtaining the first filter unit.

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