WO2024087973A1 - Puce à micro-del et son procédé de fabrication, et module d'affichage et terminal - Google Patents

Puce à micro-del et son procédé de fabrication, et module d'affichage et terminal Download PDF

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Publication number
WO2024087973A1
WO2024087973A1 PCT/CN2023/120851 CN2023120851W WO2024087973A1 WO 2024087973 A1 WO2024087973 A1 WO 2024087973A1 CN 2023120851 W CN2023120851 W CN 2023120851W WO 2024087973 A1 WO2024087973 A1 WO 2024087973A1
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Prior art keywords
micro led
color conversion
layer
light
conversion layer
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PCT/CN2023/120851
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English (en)
Chinese (zh)
Inventor
杨磊
杨以娜
张利
蒋府龙
张峰梅
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华为技术有限公司
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Publication of WO2024087973A1 publication Critical patent/WO2024087973A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission
    • H01L27/153—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission in a repetitive configuration, e.g. LED bars
    • H01L27/156—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission in a repetitive configuration, e.g. LED bars two-dimensional arrays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/50—Wavelength conversion elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/50—Wavelength conversion elements
    • H01L33/501—Wavelength conversion elements characterised by the materials, e.g. binder
    • H01L33/502—Wavelength conversion materials
    • H01L33/504—Elements with two or more wavelength conversion materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements
    • H01L33/60—Reflective elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/64—Heat extraction or cooling elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/64—Heat extraction or cooling elements
    • H01L33/641—Heat extraction or cooling elements characterized by the materials

Definitions

  • the present application relates to the field of chip technology, and in particular to a micro LED chip and a manufacturing method thereof, a display module, and a terminal.
  • micro-component manufacturing technology has become a development trend of display panels, such as micro (mirco or mini) light emitting diode (LED) technology.
  • the micro LED is a new display technology with broad application prospects and is expected to be widely used in near-eye display fields such as virtual reality (VR) or augmented reality (AR).
  • VR virtual reality
  • AR augmented reality
  • array-arranged micro LEDs are arranged, and each micro LED can be driven and lit individually as a pixel, so that the display screen can present a more delicate and contrasty picture.
  • the size of the above-mentioned micro LED is in the micron level, the distance between two adjacent pixels is very small, and the micro LED is a point light source with the characteristics of large light emission angle and dispersed light emission direction, which makes it easy for adjacent micro LEDs to have light cross-talk, affecting the display effect of the display screen.
  • the present application provides a micro LED chip and a manufacturing method thereof, a display module, and a terminal, which are used to improve the light crosstalk phenomenon of a micro LED display screen.
  • a micro LED chip which includes a substrate, a shading structure, a plurality of micro light emitting diode (LED) devices, a metal retaining wall and a plurality of color conversion layers.
  • the substrate has a first surface.
  • the shading structure is disposed on the first surface.
  • a plurality of micro light emitting diode (LED) devices are disposed on the first surface and are electrically connected to the substrate.
  • the shading structure is disposed on the first surface and is located between adjacent micro LED devices.
  • a color conversion layer covers the micro LED device, and the color conversion layer is used to convert the color of the light emitted by the micro LED device.
  • the metal retaining wall can be disposed on the side of the shading structure away from the substrate, and the metal retaining wall is located between adjacent color conversion layers. Based on this,
  • the adjacent color conversion layers can be separated by the metal retaining wall.
  • the metal retaining wall can prevent the light emitted by the micro LED device from being incident on the adjacent color conversion layer, thereby effectively reducing light crosstalk.
  • the light incident on the color conversion layer by the micro LED device can be more color converted, thereby improving the conversion efficiency of the color conversion layer and reducing the light output angle.
  • there is only a solid metal retaining wall between two adjacent color conversion layers so the metal retaining wall only needs to be subjected to a single patterning process to form the metal retaining wall, thereby reducing the steps of the manufacturing process.
  • the above-mentioned multiple micro LED devices are used to emit initial light of the same color.
  • the color conversion layer is used to receive the initial light emitted by the micro LED device covered by the color conversion layer, and output a first visible light.
  • the first visible light is different in color from the initial light.
  • the micro LED device emits blue light
  • the color conversion layer can convert the blue light into the above-mentioned first visible light, such as red light. In this way, the entire micro LED chip emits red light. Since the above-mentioned micro LED chip has high light output efficiency and a small light output angle, the light output shape of the red light emitted by the micro LED chip can be effectively narrowed.
  • the display screen prepared using the above-mentioned red light-emitting micro LED chip has higher color purity, can obtain a wider color gamut, and the light output shape is narrowed, and the light intensity of the red light is effectively improved.
  • the micro LED device is used to emit initial light.
  • the plurality of color conversion layers at least include a first color conversion layer, a second color conversion layer, and a third color conversion layer.
  • the first color conversion layer, the second color conversion layer, and the third color conversion layer cover three adjacent micro LED devices in sequence, wherein the first color conversion layer is used to receive the light covered by the first color conversion layer.
  • the first color conversion layer is used to receive the initial light emitted by the micro LED device covered by the second color conversion layer, and output the second visible light.
  • the third color conversion layer is used to receive the initial light emitted by the micro LED device covered by the third color conversion layer, and output the third visible light.
  • the first visible light, the second visible light and the third visible light are three primary colors of light respectively.
  • the first color conversion layer and the micro LED device covered by the first color conversion layer constitute a red pixel for emitting red light.
  • the second color conversion layer and the micro LED device covered by the second color conversion layer constitute a green pixel for emitting green light.
  • the third color conversion layer and the micro LED device covered by the third color conversion layer constitute a blue pixel for emitting blue light.
  • the initial light emitted by the micro LED device is blue light.
  • the first color conversion layer and the second color conversion layer include quantum dot materials.
  • the third color conversion layer is a light-transmitting structure and may include a transparent resin material, or a transparent resin material and scattering particles. Based on this, the first color conversion layer and the second color conversion layer include quantum dot materials. By adjusting the quantum dot materials in different color conversion layers, the first color conversion layer can be a red light quantum dot color conversion layer, which can convert the blue light emitted by the micro LED device into red light.
  • the second color conversion layer is a green light quantum dot color conversion layer, which can convert the blue light emitted by the micro LED device into green light.
  • the third color conversion layer is a light-transmitting structure, so that the pixel light-emitting unit composed of the third color conversion layer and the micro LED device covered by it can emit blue light, thereby realizing RGB pixel integration in a single micro LED chip.
  • the third color conversion layer includes a mixture of transparent resin material and scattering particles, the light can be scattered by scattering particles to achieve the effect of uniform light.
  • the initial light emitted by the micro LED device is ultraviolet light.
  • the first color conversion layer, the second color conversion layer, and the third color conversion layer include quantum dot materials.
  • the first color conversion layer can be a red light quantum dot color conversion layer, which can convert the ultraviolet light emitted by the micro LED device into red light.
  • the second color conversion layer can be a green light quantum dot color conversion layer, which can convert the ultraviolet light emitted by the micro LED device into green light.
  • the third color conversion layer can also be a blue light quantum dot color conversion layer, which can convert the ultraviolet light emitted by the micro LED device into blue light, thereby realizing RGB pixel integration within a single micro LED chip.
  • the micro LED chip further includes a mask structure.
  • the mask structure is disposed on a side of the metal retaining wall away from the substrate and covers the metal retaining wall. Based on this, after the metal layer is mask-etched to form the metal retaining wall, the mask material covering the metal retaining wall can be retained to form the above-mentioned mask structure. In this way, the mask structure and the metal retaining wall can enclose a space for accommodating the color conversion layer.
  • the material of the mask structure includes at least one of Ni (nickel), Cr (chromium), Ti (titanium), TiW (titanium tungsten), SiO2 (silicon dioxide), SiNx (silicon nitride), Al2O3 (aluminum oxide) and TiO2 (titanium oxide).
  • the mask material covering the metal retaining wall is the above-mentioned inorganic mask material, so that the hard mask can be formed by the above-mentioned inorganic mask material to etch the metal layer.
  • the micro LED chip further includes a plurality of transparent dielectric protection layers, one transparent dielectric protection layer is arranged around one color conversion layer and in contact with the color conversion layer.
  • the material of the transparent dielectric protection layer includes at least one of Al2O3, AlN, SiO2, SiNx, HfO2, SiCN and SiON.
  • the vertical projection of a color conversion layer on the substrate completely overlaps with the vertical projection of a micro LED device on the substrate.
  • the metal retaining wall has a retaining wall width t.
  • the diameter r of the color conversion layer, the diameter R of the micro LED device and the retaining wall width t satisfy the following formula: R ⁇ r ⁇ R+t.
  • the diameter r of the color conversion layer needs to be less than the sum of the diameter R of the micro LED device and the retaining wall width t of the metal retaining wall.
  • R ⁇ 100 ⁇ m. t ⁇ 2 ⁇ m In this way, the micro LED device can emit Light at all angles can be completely or nearly completely absorbed by the color conversion layer, and the density of the pixel light-emitting unit can also meet the design requirements.
  • the thickness h of the color conversion layer is in the range of 0.5 ⁇ m ⁇ h ⁇ 50 ⁇ m.
  • the material of the metal retaining wall includes at least one of high reflectivity metals such as Al, Ag, Pt, Au, Cu, Ti, Ni and Cr. The above metal materials have a high reflectivity and can improve the reflection effect of the metal retaining wall.
  • the angle ⁇ between the side wall of the metal retaining wall and the first surface of the substrate satisfies the following formula: 30° ⁇ 150°.
  • the shape of the cross section of the metal retaining wall can be a rectangle.
  • the shape of the cross section of the metal retaining wall can be a regular trapezoid, and a light reflection cup structure can be formed.
  • the shape of the cross section of the metal retaining wall can be an inverted trapezoid.
  • the micro LED device includes a first electrode, a second electrode and an epitaxial layer.
  • the first electrode is disposed on a first surface of a substrate and is electrically connected to the substrate.
  • the second electrode is stacked on a side of the first electrode away from the substrate; the second electrode and the metal retaining wall are in the same layer and material.
  • the epitaxial layer is disposed between the first electrode and the second electrode.
  • An optical resonant cavity is formed between the first electrode and the second electrode, and the cavity length d of the optical resonant cavity satisfies the following formula:
  • the micro LED device includes a first electrode and a second electrode stacked together, and a quantum well layer between the first electrode and the second electrode.
  • the first electrode is disposed close to the substrate and electrically connected to the substrate.
  • the micro LED chip also includes a transparent electrode layer disposed on the side of the shading structure and the micro LED device away from the substrate.
  • the transparent electrode layer is electrically connected to the second electrodes of at least two micro LED devices.
  • the transparent electrode layer is also electrically connected to the metal retaining wall.
  • the transparent electrode layer can be electrically connected to one electrode of at least two micro LED devices, such as the second electrode, to achieve a common electrode. Based on this, the other electrode of each LED device, such as the first electrode, can be insulated to individually control the opening and closing of each micro LED device in the same micro LED chip.
  • the micro LED chip further includes a flat layer, an encapsulation layer, and a micro lens array.
  • the flat layer covers the surface of the metal retaining wall and the color conversion layer on one side away from the substrate.
  • the flat layer is used to flatten the upper surface of the micro LED chip, which is beneficial to the preparation of subsequent film layers, such as the encapsulation layer.
  • the encapsulation layer covers the side of the flat layer away from the substrate, and forms an encapsulation space with the substrate, and the encapsulation space is used to accommodate the shading structure, the micro LED device, the metal retaining wall, and the color conversion layer.
  • the encapsulation layer can effectively block water and oxygen, thereby protecting the micro LED device located in the above-mentioned encapsulation space.
  • the micro lens array covers the surface of the encapsulation layer on one side away from the substrate, and the micro lens array includes a plurality of micro lenses, and one micro lens covers one micro LED device.
  • the incident light is adjusted by the micro lens to converge or diffuse the incident light before emitting it.
  • the color conversion layer includes at least one of quantum dots, quantum sheets and quantum rods.
  • the material of the color conversion layer includes a core-shell structure or an alloy structure composed of at least one of CdSe, CdS, ZnSe, ZnS, InP, CdTe, ZnTe and AgInGaS.
  • the quantum dot material of the core-shell structure may include at least one core-shell quantum dot of CdSe/CdS, CdSe/ZnSe, CdS/ZnS, InP/ZnSe, InP/ZnSe/ZnS, ZnSe/ZnS, CdSe/ZnSe/ZnS, CdSe/CdS/ZnS, InP/GaP.
  • the quantum dot material of the alloy structure may include at least one alloy quantum dot of ZnCdSe/ZnSe, CdSeS, ZnCdS, ZnCdSe/ZnS, AgInGaS/ZnS.
  • a micro LED chip in another aspect of the present application, includes a substrate, two micro light emitting diode (LED) devices, a shading structure, two color conversion layers and a metal retaining wall.
  • the substrate has a first surface.
  • Two micro light emitting diode (LED) devices are arranged on the first surface and are electrically connected to the substrate.
  • the shading structure is arranged on the first surface and is located between the two micro LED devices.
  • Each color conversion layer covers a micro LED device, and the color conversion layer is used to convert the color of the light emitted by the micro LED device; the two color conversion layers output the same color of light.
  • the metal retaining wall is arranged on the side of the shading structure away from the substrate and is located between the two color conversion layers.
  • the micro LED chip has the same technical effect as the display module provided in the aforementioned embodiment, which will not be repeated here.
  • a micro LED chip comprising a substrate, three micro light emitting diodes LED devices, shading structures, three color conversion layers and metal retaining walls.
  • the substrate has a first surface.
  • Three micro light emitting diode (LED) devices are arranged on the first surface and electrically connected to the substrate.
  • the shading structure is arranged on the first surface and is located between adjacent micro LED devices.
  • Each of the three color conversion layers covers a micro LED device, and the color conversion layer is used to convert the color of the light emitted by the micro LED device.
  • the three color conversion layers output three primary colors of light respectively.
  • the metal retaining wall is arranged on the side of the shading structure away from the substrate and is located between adjacent color conversion layers.
  • the micro LED chip has the same technical effect as the display module provided in the aforementioned embodiment, which will not be repeated here.
  • a display module which includes a circuit board and a plurality of any one of the micro LED chips described above.
  • the plurality of LED chips are arranged in an array, and the substrate of the LED chip is electrically connected to the circuit board.
  • the display module has the same technical effect as the micro LED chip provided in the aforementioned embodiment, and will not be described in detail here.
  • a terminal comprising a processor and the display module as described above.
  • the display module is electrically connected to the processor, and the processor is used to control the display module to display an image.
  • the terminal has the same technical effect as the display module provided in the aforementioned embodiment, and will not be repeated here.
  • Another aspect of the present application provides a method for manufacturing a micro LED chip, the manufacturing method comprising: first, forming a light shielding layer on a first surface on a substrate, and forming a plurality of first openings penetrating the light shielding layer on the light shielding layer, the plurality of first openings being arranged at intervals to form a light shielding structure. Next, forming a plurality of micro light emitting diode (LED) devices in the plurality of first openings, respectively, the micro LED devices being electrically connected to the substrate. Next, forming a metal layer on a side of the light shielding structure away from the substrate, and forming a plurality of second openings penetrating the metal layer on the metal layer to form a metal retaining wall.
  • LED micro light emitting diode
  • the plurality of second openings are arranged at intervals, and one second opening exposes one micro LED device.
  • the manufacturing method of the micro LED chip has the same technical effect as the micro LED chip provided in the aforementioned embodiment, and will not be repeated here.
  • forming a second opening on the metal layer that penetrates the metal layer includes: first, forming a photoresist mask on the surface of the metal layer away from the substrate through a photolithography process. Next, forming an inorganic mask layer on the surface of the photoresist mask away from the substrate, the inorganic mask layer covering the photoresist mask and the metal layer. Then, removing the photoresist mask and the portion of the inorganic mask layer covering the photoresist mask to form a mask structure. Next, using the mask structure, removing the metal layer exposed by the mask structure through an inductively coupled plasma etching process to form a second opening.
  • the mask material covering the metal retaining wall can be retained to form the above-mentioned mask structure.
  • the mask structure and the metal retaining wall can enclose a space for accommodating the color conversion layer.
  • forming a second opening on the metal layer that penetrates the metal layer includes: first, forming a photoresist mask on a surface of the metal layer away from the substrate by a photolithography process. Next, using the photoresist mask, by an inductively coupled plasma etching process, the metal layer exposed by the photoresist mask is removed to form the second opening. Next, the photoresist mask is removed. In the micro LED chip formed by the above method, a mask structure may not be required.
  • a metal layer is formed on a side of the light-shielding structure away from the substrate, and a second opening penetrating the metal layer is formed on the metal layer, including: first, a photoresist mask is formed on a side of the light-shielding structure away from the substrate. The photoresist mask covers the micro LED device. Next, a metal layer is formed on a side of the photoresist mask away from the substrate, and the metal layer covers the photoresist mask and the hollowed-out portion of the photoresist mask. Next, the photoresist mask and part of the metal layer covering the photoresist mask are removed to form a second opening. In this way, the above-mentioned metal retaining walls and the second opening located between the metal retaining walls can be manufactured by a lift-off process.
  • the metal layer has at least one pixel area, and the multiple pixel areas include a first sub-pixel area, a second sub-pixel area, and a third sub-pixel area. Based on this, forming multiple second openings through the metal layer on the metal layer includes: forming multiple second openings through the metal layer at a position where the metal layer is located in the first sub-pixel area. Next, filling the color conversion layer in the second opening includes: filling the first color conversion layer in the second opening in the first sub-pixel area, and the first color conversion layer is used to receive the initial light and output the first visible light.
  • forming multiple second openings through the metal layer on the metal layer also includes: forming multiple second openings through the metal layer at a position where the metal layer is located in the second sub-pixel area.
  • filling the color conversion layer in the second opening also includes: filling the second color conversion layer in the second opening in the second sub-pixel area, and the second color conversion layer is used to receive the initial light and output the second visible light.
  • forming multiple second openings through the metal layer on the metal layer also includes: forming multiple second openings through the metal layer at a position where the metal layer is located in the third sub-pixel area.
  • filling the second opening with a color conversion layer further includes: filling the second opening in the third sub-pixel region with a third color conversion layer, the third color conversion layer being used to receive the initial light and output a third visible light.
  • the first visible light, the second visible light and the third visible light are three primary colors.
  • the method for preparing the full-color micro LED chip only needs to add two pixel preparation processes (each pixel preparation process includes forming a second opening and filling a color conversion layer in the second opening), that is, RGB pixel integration can be achieved in a single micro LED chip.
  • filling the color conversion layer in the second opening includes: first, placing a metal layer having a shading structure, a micro-LED device, and a second opening in an aqueous solution or a polar solution. Next, applying a voltage to the metal retaining wall. Next, forming a color conversion layer in the second opening by an electrochemical deposition process. In this way, in the process of preparing the above-mentioned color conversion layer by an electrochemical deposition process using the conductive properties of the metal retaining wall, the parameters of the electrochemical process can be adjusted to control the thickness and filling density of the color conversion layer, thereby improving the filling uniformity of the color conversion layer in the second opening, thereby improving the integration of the manufacturing process.
  • the adjacent color conversion layers can be separated by the metal retaining wall.
  • the metal retaining wall can prevent the light emitted by the micro LED device from being incident on the adjacent color conversion layer, thereby effectively reducing the light crosstalk.
  • the light incident on the color conversion layer by the micro LED device can be more color converted, thereby improving the conversion efficiency of the color conversion layer and reducing the light output angle.
  • the metal retaining wall only needs to be patterned once to form the metal retaining wall, thereby reducing the steps of the manufacturing process.
  • the above-mentioned metal retaining wall has good thermal conductivity, which can improve the heat dissipation effect of the micro LED chip.
  • the cross-sectional shape of the metal retaining wall can be adjusted to form a reflective cup structure.
  • the aperture ratio of the pixel light-emitting unit (a color conversion layer and the micro LED device corresponding to its position) and the quantum dot absorption rate of the color conversion layer can be adjusted to improve the light extraction efficiency of the micro LED device and the conversion efficiency of the color conversion layer.
  • the second electrode of the micro LED device in the process of etching the metal retaining wall, can be formed at the bottom of the opening surrounded by the metal retaining wall, and by controlling the thickness of the second electrode, an optical resonant cavity is formed between the first electrode and the second electrode of the micro light-emitting device to reduce light loss, thereby achieving the purpose of improving the vertical light extraction efficiency of the micro LED device.
  • an electrochemical deposition process can be used to form a color conversion layer in the opening surrounded by the metal retaining wall, so that the thickness and filling density of the color conversion layer can be controlled.
  • FIG1 is a schematic diagram of the structure of a terminal provided in an embodiment of the present application.
  • FIG2A is a schematic structural diagram of the display module in FIG1 ;
  • FIG2B is a top view of the display module taken along direction A in FIG2A ;
  • FIG2C is another top view of the display module taken along direction A in FIG2A ;
  • FIG3 is a cross-sectional view of the micro LED chip cut along the dotted line C-C in FIG2B ;
  • FIG4 is a schematic diagram of a structure of the micro LED device in FIG3 ;
  • FIG5 are schematic diagrams of three structures of quantum dot materials in the color conversion layer in FIG3 ;
  • FIG6A is a schematic diagram of the structure of a micro LED chip provided in an embodiment of the present application.
  • FIG6B is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG6C is another partial structural schematic diagram of a micro LED chip provided in an embodiment of the present application.
  • FIG7A is a schematic diagram of the structure of another micro LED chip provided in an embodiment of the present application.
  • FIG7B is a schematic diagram of a partial structure of another micro LED chip provided in an embodiment of the present application.
  • FIG. 7C is a schematic diagram of a manufacturing process of another micro LED chip provided in an embodiment of the present application.
  • FIG7D is a schematic diagram of the structure of another micro LED chip provided in an embodiment of the present application.
  • FIG8 are respectively a waveform diagram of wavelength and light intensity of a micro LED chip provided in an embodiment of the present application and a polar coordinate light distribution curve diagram;
  • FIG9 are respectively a waveform diagram of wavelength and light intensity of another micro LED chip provided in an embodiment of the present application and a polar coordinate light distribution curve diagram;
  • FIG. 10 (a) and (b) are respectively a waveform diagram of wavelength and light intensity of another micro LED chip provided in an embodiment of the present application and a polar coordinate light distribution curve diagram;
  • FIG11 is a flow chart of a method for manufacturing a micro LED chip provided in an embodiment of the present application.
  • FIG12 is another partial structural schematic diagram of a micro LED chip provided in an embodiment of the present application.
  • FIG. 13 are schematic diagrams corresponding to different manufacturing steps of a micro LED chip provided in an embodiment of the present application.
  • FIG. 14 are schematic diagrams corresponding to different manufacturing steps of another micro LED chip provided in an embodiment of the present application.
  • FIG15A is another partial structural schematic diagram of a micro LED chip provided in an embodiment of the present application.
  • FIG15B is another partial structural schematic diagram of a micro LED chip provided in an embodiment of the present application.
  • FIG. 16 are schematic diagrams corresponding to different manufacturing steps of another micro LED chip provided in an embodiment of the present application.
  • FIG17A is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG17B is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG17C is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG17D is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG. 18 is a schematic diagram of a manufacturing process of a micro LED chip provided in an embodiment of the present application.
  • FIG19 is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG20 is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG21 is a schematic diagram of a partial structure of a micro LED chip provided in an embodiment of the present application.
  • FIG. 22 is a flow chart of another method for manufacturing a micro LED chip provided in an embodiment of the present application.
  • FIG. 23 are schematic diagrams corresponding to different manufacturing steps of another micro LED chip provided in an embodiment of the present application.
  • directional terms such as “upper”, “lower”, “lateral”, and “longitudinal” may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative description and clarification, and may change accordingly according to changes in the orientation of the components in the drawings.
  • connection should be understood in a broad sense.
  • connection can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.
  • electrical connection can be a direct electrical connection or an indirect electrical connection through an intermediate medium. Electrically connected components can transmit electrical signals through wired or wireless means.
  • the present application provides a terminal that can have a display function.
  • the terminal can be applied to various communication systems or communication protocols, such as: global system of mobile communication (GSM), code division multiple access (CDMA), wideband code division multiple access wireless (WCDMA), general packet radio service (GPRS), long term evolution (LTE), etc. term evolution, LTE), etc.
  • GSM global system of mobile communication
  • CDMA code division multiple access
  • WCDMA wideband code division multiple access wireless
  • GPRS general packet radio service
  • LTE long term evolution
  • LTE long term evolution
  • the terminal may include a mobile phone, a tablet computer (pad), a television, a smart wearable product (for example, a smart watch, a smart bracelet), a VR terminal device, an AR terminal device, etc.
  • the embodiment of the present application does not impose any special restrictions on the specific form of the above-mentioned terminal.
  • the terminal 01 may include a display module 10 and a processor 11.
  • the display module 10 may be electrically connected to the processor 11.
  • the processor 11 may include one or more processing units, for example: the processor 11 may include an application processor (application processor, AP), a modem processor, a graphics processor (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and/or a neural network processor (neural-network processing unit, NPU), etc.
  • different processing units may be independent devices or integrated in one or more processors.
  • the processor 11 may be used to control the display module 10 to display images.
  • the terminal 01 may also include an external memory interface, an internal memory, a universal serial bus (USB) interface, a charging management module, a power management module, a battery, an antenna, a mobile communication module, a wireless communication module, an audio module, a speaker, a receiver, a microphone, an earphone interface, a sensor module, a button, and a camera, etc., which are electrically connected to the processor 11.
  • the sensor module may include a pressure sensor, a gyroscope sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, and a bone conduction sensor, etc.
  • the display module 10 may be a micro or mini LED display screen (referred to as an MD display screen), or an organic light emitting diode (OLED) display screen.
  • the display module 10 may include the circuit board 100 and a plurality of micro LED chips (die) 20 disposed on the circuit board 100.
  • the plurality of micro LED chips 20 may be arranged at intervals and arranged in an array.
  • the micro LED chip 20 may be a micro LED chip, the size of which is usually less than 50 ⁇ m.
  • the micro LED chip 20 may be a mini LED chip, the size of which is usually between 50 ⁇ m and 200 ⁇ m.
  • the circuit board 100 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB).
  • three adjacent micro LED chips 20 can be used to emit three primary colors of light respectively.
  • the three primary colors of light can be red (red, R) light, green (green, G) light, and blue (blue, B) light.
  • the three adjacent micro LED chips 20 can be used as a pixel (pixel, P) of the display module 10, and each micro LED chip 20 in the pixel can be a sub-pixel (sub pixel).
  • a single micro LED chip 20 can emit at least one of the three primary colors.
  • a single micro LED chip 20 can emit R light, G light, or B light.
  • a single micro LED chip 20 can emit R light, G light, and B light at the same time, and the light obtained by mixing the above R light, G light, and B light is received by the user as the outgoing light of the single micro LED chip 20.
  • a single micro LED chip 20 can emit any two of R light, G light, and B light at the same time, and the light obtained by mixing the above any two lights is received by the user as the outgoing light of the single micro LED chip 20.
  • a single micro LED chip 20 can serve as a pixel of the display module 10.
  • FIG. 2B and FIG. 2C are illustrated by taking the pixel arrangement of the display module 10 as an example in which the R pixel, the G pixel, and the B pixel in the same pixel are arranged in the same row in sequence.
  • the arrangement of the three primary color pixels of R, G, and B can be determined according to the requirements of display effect, pixel density (pixels per inch, PPI), resolution and other parameters, and this application does not limit this.
  • the arrangement of the pixels of the above-mentioned display module 10 can also be a Pentile pixel arrangement (also called a P arrangement), a Delta pixel arrangement (also called a D arrangement), and a diamond arrangement.
  • micro LED chip 20 The structure and manufacturing method of the micro LED chip 20 provided in the embodiment of the present application are described in detail below through specific examples.
  • This example adopts the structure shown in FIG2B , where a single micro LED chip 20 can emit one of the three primary colors, such as R light, G light, or B light.
  • the light of different colors emitted by three adjacent micro LED chips 20 is mixed (combined) and displayed as a pixel of the above display module.
  • the structure of the micro LED chip 20 is described by way of example.
  • the micro LED chip 20 may include a substrate 201 and a plurality of micro LED devices 202 electrically connected to the substrate 201.
  • the substrate 201 may have a first surface E1 and a second surface E2 disposed opposite to each other.
  • the micro LED chip 20 may be bonded to the circuit board 100 shown in FIG. 2A through the second surface E2 of the substrate 201 by solder ball bonding or wafer bonding, thereby achieving electrical connection between the micro LED chip 20 and the circuit board 100.
  • the substrate 201 may be a packaging substrate, and a plurality of drive circuits arranged in an array may be disposed in the substrate 201, and each drive circuit may be used to control the opening and closing of a single micro LED device 202.
  • each micro LED device 202 in the micro LED chip 20 can be a micro LED device that emits B light (represented as B ⁇ -LED in the figure) or a micro LED device that emits G light, and the present application does not limit this.
  • B ⁇ -LED represented as B ⁇ -LED in the figure
  • G light a micro LED device that emits G light
  • the present application does not limit this.
  • the following examples are all taken as an example that the light emitted by the micro LED device 202 is B light.
  • the structure of the micro LED device 202 is shown in FIG.
  • the first electrode 212 is disposed on the first surface E1 of the substrate 201 (as shown in FIG. 3) and is electrically connected to the substrate 201.
  • the second electrode 222 is stacked and disposed on the side of the first electrode 212 away from the substrate 201 (as shown in FIG. 3).
  • the epitaxial layer 232 between the first electrode 212 and the second electrode 222 may include an N-type doped semiconductor layer 2321 (denoted as N-GaN in the figure), a P-type doped semiconductor layer 2322 (denoted as N-GaN in the figure), and a multiple quantum well layer 2323 (multiple quantum well, MQW) between the N-type doped semiconductor layer 2321 and the P-type doped semiconductor layer 2322.
  • the material of the multiple quantum well layer 2323 may include indium gallium nitride (InGaN).
  • the N-type doped semiconductor layer 2321 is electrically connected to the above-mentioned first electrode 212.
  • the N-type doped semiconductor layer 2321 can be formed by performing N-type doping in a pure semiconductor material (i.e., an intrinsic semiconductor material), for example, by doping a tetravalent element.
  • a pure semiconductor material i.e., an intrinsic semiconductor material
  • free electrons are majority carriers and holes are minority carriers.
  • the pure semiconductor material can be gallium nitride (GaN), and the tetravalent element can be silicon (Si). In this way, the N-type doped semiconductor layer 2321 mainly conducts electricity by free electrons.
  • the first electrode 212 electrically connected to the N-type doped semiconductor layer 2321 can also be called an N-electrode.
  • the above is an explanation of the N-type doping process by taking the doping of tetravalent elements in pure semiconductor materials as an example.
  • the present application does not limit the doping elements in the N-type doping, as long as the free electrons in the N-type doped semiconductor layer 2321 are majority carriers and the holes are minority carriers when the performance of the micro LED device 202 meets the requirements.
  • the P-type doped semiconductor layer 2322 is electrically connected to the above-mentioned second electrode 222.
  • the P-type doped semiconductor layer 2322 can be formed by P-type doping in a pure semiconductor material, for example, by doping with a divalent element. In the formed P-type doped semiconductor layer 2322, free holes are majority carriers, and free electrons are minority carriers.
  • the pure semiconductor material can be GaN, and the divalent element can be magnesium (Mg). In this way, the P-type doped semiconductor layer 2322 is mainly conductive by holes. The greater the concentration of the doped element during the P-type doping process, the higher the concentration of majority carriers (holes), and the stronger the conductivity of the P-type doped semiconductor layer 2322.
  • the second electrode 222 coupled to the P-type doped semiconductor layer 2322 can also be called a P-electrode.
  • the above is an explanation of the P-type doping process by taking the doping of divalent elements in pure semiconductor materials as an example.
  • the present application does not limit the doping elements in the P-type doping, as long as the P-type doped semiconductor layer 2322 can be made into majority holes and minority free electrons while the performance of the micro LED device 202 meets the requirements.
  • a PN junction can be formed between the N-type doped semiconductor layer 2321 and the P-type doped semiconductor layer 2322 shown in FIG. 4.
  • the multi-quantum well layer 2323 is located in the active region of the PN junction. Therefore, a micro LED device 202 in the micro LED chip 20 (as shown in FIG. 3 ) has a PN junction.
  • the driving circuit in the substrate 201 (as shown in FIG. 3 ) of the micro LED chip 20 provides voltages to the first electrode 212 and the second electrode 222 of each micro LED device 202 to form an external electric field.
  • the external electric field can control the current flowing through the multi-quantum well layer 2323 of the micro LED device 202, thereby controlling the number of photons excited in the multi-quantum well layer 2323, thereby achieving the purpose of controlling the luminous brightness of the micro LED device 202.
  • the driving circuit in the substrate 201 (as shown in FIG. 3 ) of the micro LED chip 20 may include a plurality of transistors and at least one capacitor.
  • the transistors may be thin film transistors (TFT) or metal oxide semiconductor field effect transistors (FETs). MOSFET).
  • the field effect transistor may include at least one of an N-type metal oxide semiconductor transistor (negative channel metal oxide semiconductor, NMOS), a P-type metal oxide semiconductor transistor (positive channel-metal-oxide-semiconductor, PMOS) and a complementary metal oxide semiconductor transistor (complementary metal oxide semiconductor, CMOS).
  • the present application does not limit the structure of the driving circuit.
  • the substrate 201 of a single micro LED chip 20 is electrically connected to a plurality of micro LED devices 202. Since each micro LED device 202 has a PN junction, a single micro LED chip 20 has a plurality of PN junctions.
  • the driving circuit in the substrate 201 can individually control each micro LED device 202 to emit light independently. In order to improve the control accuracy of the light emitting brightness of each micro LED device 202 and avoid crosstalk between the light emitted by adjacent micro LED devices 202.
  • the above-mentioned micro LED chip 20 may further include a light shielding structure 203.
  • the shading structure 203 can be disposed on the first surface E1 of the substrate 201.
  • the shading structure 203 surrounds a plurality of first openings 31, and the plurality of first openings 31 are disposed at intervals.
  • the first openings 31 can expose at least a portion of the driving circuit in the substrate 201.
  • a micro LED device 202 is disposed in a first opening 31 and is electrically connected to the driving circuit in the substrate 201, so that the shading structure 203 can be located between adjacent micro LED devices 202, thereby separating adjacent multiple micro LED devices 202.
  • the shading structure 203 can be made of a shading material with a light transmittance of less than 20%, so as to avoid crosstalk between the light emitted by adjacent multiple micro LED devices 202.
  • the micro LED chip 20 may further include a metal retaining wall 204 and a plurality of color conversion layers 205.
  • the metal retaining wall 204 may be disposed on a side of the light shielding structure 203 away from the substrate 201.
  • the metal retaining wall 204 surrounds a plurality of second openings 32, and the plurality of second openings 32 are arranged at intervals.
  • a second opening 32 exposes a micro LED device 202.
  • a color conversion layer 205 is located in a second opening 32 and covers the micro LED device 202 exposed by the second opening 32, so that the metal retaining wall 204 can be located between adjacent color conversion layers 205.
  • the color conversion layer 205 is used to convert the color of the light emitted by the micro LED device 202.
  • the material constituting the color conversion layer 205 may be a quantum dot (QD) material.
  • the quantum dot material may include a core-shell structure or an alloy structure composed of at least one of CdSe (cadmium selenide), CdS (cadmium sulfide), ZnSe (zinc selenide), ZnS (zinc sulfide), InP (indium phosphide), CdTe (cadmium telluride), ZnTe (zinc telluride) and AgInGaS (silver indium gallium sulfide).
  • the quantum dot material may also be a core-shell structure and an alloy structure composed of at least one of the above materials.
  • the quantum dot material of the core-shell structure may include at least one of CdSe/CdS, CdSe/ZnSe, CdS/ZnS, InP/ZnSe, InP/ZnSe/ZnS, ZnSe/ZnS, CdSe/ZnSe/ZnS, CdSe/CdS/ZnS, and InP/GaP.
  • the quantum dot material of the alloy structure may include at least one of ZnCdSe/ZnSe, CdSeS, ZnCdS, ZnCdSe/ZnS, and AgInGaS/ZnS alloy quantum dots.
  • the material of the color conversion layer 205 is a quantum dot material.
  • the material of the color conversion layer 205 may also be an organic light-emitting material, or other fluorescent or phosphorescent materials.
  • the following embodiments are all based on the example that the material of the color conversion layer 205 is a quantum dot material.
  • the structure of the quantum dot can be a three-dimensional quantum dot as shown in (a) of FIG5 , or a two-dimensional quantum sheet as shown in (b) of FIG5 , or a one-dimensional quantum rod as shown in (c) of FIG5 .
  • the present application does not limit the structure of the quantum dot.
  • the wavelength of the light emitted by the color conversion layer 205 under the excitation of the light emitted by the micro LED device 202 can be controlled, and the purpose of color conversion is finally achieved, so that the micro LED chip 20 can emit the required light.
  • the red light quantum dot color conversion layer 205 (indicated by R-QD in the figure) emits R light under the excitation of the light emitted by the micro LED device 202, such as B light, to achieve color conversion.
  • the metal retaining wall 204 separates the adjacent multiple color conversion layers 205.
  • the metal retaining wall 204 can be arranged around the color conversion layer 205. After the light emitted by the micro LED device 202 is incident on the color conversion layer 205, a part of it directly excites the color conversion layer 205 to emit light, such as R light, and a part of it will be incident on the metal retaining wall 204, and then reflected by the metal retaining wall 204 and enter the color conversion layer 205 again to excite the color conversion layer 205 to emit R light.
  • a shading structure 203 and a micro LED device 202 can be first formed on a substrate 201 having a driving circuit as shown in FIG6B .
  • a metal retaining wall is formed by patterning the metal layer. 204, and then forming the color conversion layer 205 as shown in FIG. 6A in the second opening 32 surrounded by the adjacent metal retaining wall 204.
  • the above-mentioned patterning process may refer to a photolithography process, or a photolithography process and an etching step, and may also include other processes such as printing and inkjetting for forming a predetermined pattern.
  • the photolithography process refers to a process for forming a pattern using a photoresist, a mask, an exposure machine, etc., including processes such as film formation, alignment, exposure, and development.
  • the corresponding patterning process can be selected according to the structure formed in the present invention.
  • the one-time patterning process in the embodiment of the present application is explained by taking the example of forming different exposure areas through a mask exposure process, and then performing at least one etching, ashing, and other removal processes on the different exposure areas to finally obtain the expected pattern.
  • a metal layer covering the light shielding structure 203 and the micro LED device 202 can be formed on the structure formed with the light shielding structure 203. Then, a metal retaining wall 204 is formed by patterning the metal layer. The metal retaining wall 204 separates adjacent color conversion layers 205. In this way, on the one hand, the metal retaining wall 204 can prevent the light emitted by the micro LED device 202 from being incident on the color conversion layer 205 adjacent to the color conversion layer 205 located directly above the micro LED device 202, thereby effectively reducing light crosstalk and improving the display effect of the display module.
  • the metal retaining wall 204 can be made of a metal material with high reflectivity, such as at least one of Al (aluminum), Ag (silver), Pt (platinum), Au (gold), Cu (copper), Ti (titanium), nickel (Ni) and Cr (chromium).
  • the dielectric layer retaining wall 40 is an inorganic dielectric material such as SiO2, SiNx, Al2O3, AlN, etc.
  • the above-mentioned dielectric layer retaining wall 40 is first formed on the structure formed with ⁇ -LED through at least one composition process.
  • a metal film layer 41 is covered on the upper surface of the dielectric layer retaining wall 40 and the light-emitting surface of the ⁇ -LED, and then the metal film layer 41 is etched to expose the ⁇ -LED below.
  • the above-mentioned QD layer is formed between adjacent dielectric layer retaining walls 40. In this way, the incident light can be reflected by the metal film layer 41.
  • the metal film layer 41 covering the surface of the dielectric layer retaining wall 40 will also be etched.
  • the cross section of the dielectric layer retaining wall 40 is a regular trapezoid as shown in FIG. 7C
  • the metal film layers 41 on both sides of the regular trapezoid are easily etched, resulting in the destruction of the reflective surface of the metal film layer 41 close to the QD layer and the appearance of a gap, so that part of the QD layer directly contacts the dielectric layer retaining wall 40 through the above-mentioned gap, destroying the structure of the formed metal retaining wall 204.
  • the light emitted by the ⁇ -LED will still be incident on the adjacent QD layer through the above-mentioned gap, reducing the effect of reducing crosstalk.
  • the solid metal retaining wall 204 is spaced between two adjacent color conversion layers 205, not a metal film layer. Therefore, in the process of etching the metal retaining wall 204 to form the metal retaining wall, the surface of the metal retaining wall 204 close to the color conversion layer 205 can form a complete reflective surface, which can effectively avoid the damage to the formed metal retaining wall 204 during the etching process, so that the preparation of metal retaining walls with various shapes such as regular trapezoid, inverted trapezoid, rectangle, etc.
  • the angle ⁇ between the bottom and side of the cross section of the metal retaining wall, that is, the side wall of the metal retaining wall 204 and the first surface of the substrate can be in the range of 30° ⁇ 150°, thereby realizing the light shape control of the MD device.
  • the subsequent embodiments will further explain the implementation method of the cross-sectional shape of the metal retaining wall in detail.
  • the two adjacent QD layers are separated by not only the stacked dielectric layer retaining wall 40 and the metal film layer 41, but also need to be formed by at least two patterning processes respectively.
  • the two adjacent color conversion layers 205 are separated by only a solid metal retaining wall 204, and the metal retaining wall 204 only needs to be patterned once to form the metal retaining wall 204. Therefore, the steps of the manufacturing process can be reduced, the process flow can be simplified, and the production efficiency can be improved.
  • the micro LED chip 20 provided in the embodiment of the present application includes a plurality of micro LED devices 202 and a plurality of color conversion layers 205.
  • a color conversion layer 205 is correspondingly provided on the light-emitting side of each micro LED device 202.
  • the LED chip 20 includes two micro LED devices 202 and two color conversion layers 205, and each color conversion layer 205 covers one micro LED device 202.
  • the micro LED chip 20 includes three micro LED devices 202 and three color conversion layers 205, and each color conversion layer 205 covers one micro LED device 202.
  • a single micro LED chip 20 can emit monochromatic light.
  • the multiple micro LED devices 202 can be respectively located in multiple first openings 31 that are adjacent in sequence.
  • the multiple micro LED devices 202 are used to emit initial light of the same color, for example, all emit B light.
  • multiple color conversion layers 205 are sequentially located in multiple adjacent second openings 32, and respectively cover multiple micro LED devices 202 that are adjacent in sequence.
  • the color conversion layer 205 is used to receive the initial light (for example, B light) emitted by the micro LED device 202 covered by the color conversion layer 205, and output a first visible light (for example, R light), the first visible light (for example, R light) is different in color from the initial light (for example, B light), so that a single micro LED chip 20 can emit monochromatic light, for example, R light.
  • the metal retaining wall 204 is formed by patterning the metal retaining wall 204.
  • the metal retaining wall 204 separates the adjacent color conversion layers 205.
  • Each color conversion layer 205 and the micro LED device 202 covered by the color conversion layer 205 can constitute a pixel light-emitting unit.
  • the metal retaining wall 204 can reflect the initial light incident on the color conversion layer 205 by the micro LED device 202, for example, the B light, so as to improve the conversion efficiency of the color conversion layer 205 while effectively reducing the angle of the light emitted by the pixel light-emitting unit (a color conversion layer 205 and the micro LED device 202 corresponding to its position), thereby effectively narrowing the light shape of the micro LED chip 20.
  • the color conversion layer 205 is a red light quantum dot color conversion layer
  • the micro LED device 202 is a blue light micro LED device as an example.
  • the full width at half maxima (FWHM) and the light shape of the micro LED chip 20 are illustrated for different thicknesses of the color conversion layer 205.
  • the thickness b of the color conversion layer 205 is 1.0 ⁇ m
  • the waveform diagram of the wavelength and light intensity of the micro LED chip 20 shown in (a) of FIG8 it can be seen from the waveform diagram of the wavelength and light intensity of the micro LED chip 20 shown in (a) of FIG8 that the FWHM of the micro LED chip 20 is relatively narrow, about 36 nm. Therefore, the color purity of the light emitted by the micro LED chip 20 is relatively high.
  • the light output shape corresponding to the micro LED chip 20 is shown in (b) of FIG8 . It can be seen from the polar coordinate light distribution curve of the micro LED chip 20 that when the thickness b of the color conversion layer 205 (or the metal retaining wall 204) is 1.0 ⁇ m, the corresponding light output angle of the micro LED chip 20 is about ⁇ 63°.
  • the thickness b of the color conversion layer 205 is 1.5 ⁇ m, it can be seen from the waveform diagram of the wavelength and light intensity of the micro LED chip 20 shown in (a) of FIG9 that the FWHM of the micro LED chip 20 is relatively narrow, about 38 nm. Therefore, the color purity of the light emitted by the micro LED chip 20 is relatively high.
  • the light output shape of the micro LED chip 20 when the thickness b of the color conversion layer 205 (or the metal retaining wall 204) is 1.5 ⁇ m is significantly narrowed, and the light output angle is about ⁇ 45°, that is, the increase in the thickness of the metal retaining wall 204 can effectively reduce the light output angle of the micro LED chip 20.
  • the display screen prepared by the above-mentioned R-light-emitting micro LED chip 20 has high color purity and can obtain a wider color gamut.
  • the light shape of the light is narrowed, which is beneficial to the subsequent optical waveguide module of the AR or VR device to effectively utilize the R light emitted by the MD screen that emits R light, thereby improving the energy utilization efficiency of the overall display system.
  • the thickness b of the color conversion layer 205 is 2.0 ⁇ m
  • the FWHM of the micro LED chip 20 is relatively narrow, about 33 nm. Therefore, the color purity of the light emitted by the micro LED chip 20 is relatively high.
  • the micro LED chip 20 By comparing the polar coordinate light distribution curve of the micro LED chip 20 shown in (b) of FIG10 with (b) of FIG8 , it can be seen that when the thickness of the metal retaining wall 204, that is, the thickness b of the color conversion layer, is thickened to 2.0 ⁇ m, the light output shape of the micro LED chip 20 is narrowed, which can effectively reduce the light output angle of the micro LED chip 20. As above, the micro LED chip 20 is applied to the field of near-eye display, and a wider color gamut can be obtained, and the light intensity of the R light can be effectively improved, solving the problem of red light efficiency in micro LED display.
  • the method for manufacturing the micro LED chip 20 emitting R light as shown in FIG6A may include S101 to S106 as shown in FIG11 .
  • a light shielding layer is formed on the first surface E1 of the substrate 201 , and a plurality of first openings 31 penetrating the light shielding layer are formed on the light shielding layer by a photolithography process.
  • the plurality of first openings 31 are arranged at intervals to form a light shielding structure 203 .
  • a micro LED device 202 is fabricated in the first opening 31, or the fabricated micro LED device 202 is disposed in the first opening 31 by transfer.
  • the micro LED device 202 is electrically connected to the substrate 201.
  • the first electrode 212 of the micro LED device (as shown in FIG. 4 ) is electrically connected to the driving circuit in the substrate 201.
  • the cross-section of the first opening 31 (the cross-section is perpendicular to the substrate 201) may be rectangular, trapezoidal or inverted trapezoidal as shown in FIG. 6B, and the present application does not limit this.
  • the cross-section of the micro LED device 202 formed in the first opening 31 (the cross-section is perpendicular to the substrate 201) may be rectangular as shown in FIG. 6A.
  • the cross-section of the micro LED device 202 formed in the first opening 31 may be a regular trapezoid as shown in FIG. 8 (a), FIG. 9 (a) and FIG. 10 (a).
  • the cross-section of the micro LED device 202 formed in the first opening 31 may be an inverted trapezoid.
  • a transparent electrode layer 206 is deposited on the side of the light shielding structure 203 away from the substrate.
  • the transparent electrode layer 206 can be electrically connected to the second electrodes 222 (as shown in FIG4 ) of at least two micro LED devices 202.
  • the second electrode 222 is the cathode of the micro LED device 202
  • the cathodes of multiple micro LED devices 202 can be electrically connected through the transparent electrode layer 206 to realize a common cathode of multiple micro LED devices 202.
  • the anodes (the first electrodes 212 as shown in FIG4 ) of each micro LED device 202 can be insulated to individually control the opening and closing of each micro LED device 202 in the same micro LED chip 20.
  • the thickness of the transparent electrode layer 206 can be 10nm to 500nm.
  • the thickness of the transparent electrode layer 206 is less than 10nm, the precision requirement for the manufacturing process is high, which is not conducive to cost saving.
  • the thickness of the transparent electrode layer 206 is greater than 500nm, the thickness of the transparent electrode layer 206 is too thick, and it is not easy to achieve ultra-thinness of the device.
  • the thickness of the above-mentioned transparent electrode layer 206 can be in the range of 10nm to 500nm, and can be selected from 10nm, 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm.
  • the material of the transparent electrode layer 206 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), zinc oxide (ZnO), zinc magnesium oxide (ZnMgO), aluminum-doped zinc oxide (AZO), and zirconium oxide (ZrO2).
  • ITO indium tin oxide
  • IZO indium zinc oxide
  • IGZO indium gallium zinc oxide
  • ZnO zinc oxide
  • ZnMgO zinc magnesium oxide
  • AZO aluminum-doped zinc oxide
  • ZrO2 zirconium oxide
  • the metal retaining wall can be formed by a variety of methods. For example, first, as shown in (a) of FIG. 13 , on the side of the transparent electrode layer 206 away from the substrate 201, a metal layer 30 is formed by using the above-mentioned metal material with high reflectivity (Al, Ag, Pt, Au, Cu, Ti, Ni or Cr, etc.) through an electron beam coating (Ebeam) process, a vacuum sputtering coating (sputter) process or a metal film forming process such as thermal evaporation.
  • the thickness of the metal layer 30 can be 0.5 ⁇ m to 50 ⁇ m. When the thickness of the metal layer 30 is less than 0.5 ⁇ m, the precision requirement for the manufacturing process is high, which is not conducive to cost saving.
  • the thickness of the metal layer 30 may be in the range of 0.5 ⁇ m to 50 ⁇ m, and may be 0.5 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m, 35 ⁇ m, 40 ⁇ m, 45 ⁇ m or 50 ⁇ m.
  • a layer of photoresist is spin-coated on the surface of the metal layer 30 away from the substrate 201, and a photoresist mask 50 is formed by a photolithography process or a development process, and the photoresist mask 50 exposes the position where the micro LED device 202 is located.
  • the metal layer 30 is etched by a dry etching process or a wet etching process using the photoresist mask 50, and the etching can be stopped when the above-mentioned transparent electrode layer 206 is etched.
  • the metal layer 30 can be etched by inductively coupled plasma (ICP) to remove the metal layer exposed by the photoresist mask 50, so as to form a plurality of second openings 32 penetrating the metal layer 30 as shown in (c) of FIG. 13 .
  • ICP inductively coupled plasma
  • the formed second opening 32 exposes a micro LED device 202.
  • the portion of the metal layer 30 covered by the photoresist mask 50 (as shown in (b) of FIG. 13 ) is not etched, thereby forming a metal retaining wall 204 as shown in (c) of FIG. 13 .
  • the adjacent second openings 32 are separated by the metal retaining wall 204.
  • the metal retaining wall 204 can be electrically connected to the transparent electrode layer 206, and the metal retaining wall 204 can be used as a metal interconnection wiring layer for a common electrode (e.g., a common cathode) of multiple micro LED devices 202 to enhance the charge transfer efficiency of the micro LED devices 202 and improve the device integration.
  • the metal retaining wall 204 has good thermal conductivity and can effectively dissipate the heat generated during the operation of the micro LED chip 20.
  • the metal retaining wall may be formed by, for example, firstly, as shown in FIG. 14 (a), the transparent electrode may be formed in sequence. After the electrode layer 206 and the metal layer 30 are formed, a photoresist is formed on the side surface of the metal layer 30 away from the substrate 201, and a photoresist mask 50 is formed by a photolithography process or a development process. The photoresist mask 50 covers the position where the micro LED device 202 is located. Next, as shown in (b) of Figure 14, an inorganic mask layer 51 is formed on the side surface of the photoresist mask 50 away from the substrate 201, and the inorganic mask layer 51 covers the photoresist mask 50 and the metal layer 30.
  • the material of the inorganic mask layer 51 may include at least one of Ni (nickel), Cr (chromium), Ti (titanium), TiW (titanium tungsten), SiO2 (silicon dioxide), SiNx (silicon nitride), Al2O3 (aluminum oxide) and TiO2 (titanium oxide).
  • the photoresist mask 50 and the portion of the inorganic mask layer 51 covering the photoresist mask 50 are removed to form a mask structure 52 as shown in (c) of Figure 14, which is a hard mask.
  • the mask structure 52 is used to remove the metal layer 30 exposed by the mask structure through an ICP etching process to form a second opening 32 as shown in (d) of Figure 14.
  • the mask structure 52 may be retained.
  • the micro LED chip 20 may include the above-mentioned mask structure 52.
  • the mask structure 52 may include a plurality of third openings 33, and the plurality of third openings 33 are arranged at intervals. A third opening 33 is connected to a second opening 32 to form a space for accommodating a color conversion layer 205.
  • etching conditions can be set so that the angle ⁇ between the side wall of the second opening 32 and the first surface E1 of the substrate 201 satisfies the following formula: 30° ⁇ 150°.
  • ⁇ 90°
  • the shape of the cross section of the metal retaining wall 204 can be a rectangle.
  • 90° ⁇ 150° as shown in FIG.
  • the shape of the cross section of the metal retaining wall 204 (the cross section is perpendicular to the substrate 201) can be a regular trapezoid, and a light reflection cup structure can be formed at this time.
  • the shape of the cross section of the metal retaining wall 204 (the cross section is perpendicular to the substrate 201) can be an inverted trapezoid, which is more conducive to narrowing the light shape.
  • the parameters of the etching process can be controlled so that a portion of a thin metal film remains at the bottom of the second opening 32, as shown in (c) of FIG. 13.
  • the metal film can be used as the second electrode 222 of the micro LED device 202.
  • the second electrode 222 of the micro LED device 202 and the metal retaining wall 204 are in the same layer and made of the same material.
  • an optical resonant cavity can be formed between the high-reflectivity first electrode 212 and the high-reflectivity second electrode 222 of the micro-light-emitting device 202 as shown in FIG4, so that the light emitted by the micro-LED device 202 is concentrated in the optical resonant cavity to reduce light loss, thereby achieving the purpose of improving the vertical light-emitting efficiency of the micro-LED device 202 and optimizing the light shape of the device.
  • the cavity length d of the optical resonant cavity (the distance from the upper surface of the first electrode 212 to the lower surface of the second electrode 222) satisfies the following formula:
  • q is the number of resonant modes
  • ⁇ is the wavelength of light emitted by the micro LED device
  • n is the refractive index of the epitaxial layer.
  • the same layer refers to a layer structure formed by using the same film-forming process to form a film layer for forming a specific pattern, and then using the same mask through a single patterning process.
  • the same patterning process may include multiple exposure, development or etching processes, and the specific patterns in the formed layer structure may be continuous or discontinuous, and these specific patterns may also be at different heights or have different thicknesses.
  • the metal retaining wall can also be made by a lift-off process.
  • a photoresist can be formed on the side of the light shielding structure 203 away from the substrate 201, for example, on the side surface of the transparent electrode layer 206 away from the substrate 201, and a photoresist mask 50 is formed by a photolithography process or a development process, and the photoresist mask 50 covers the position where the micro LED device 202 is located.
  • a photoresist mask 50 is formed by a photolithography process or a development process, and the photoresist mask 50 covers the position where the micro LED device 202 is located.
  • a metal layer 30 is formed on the side surface of the photoresist mask 50 away from the substrate 201, and the metal layer 30 covers the photoresist mask 50 and the hollowed-out part of the photoresist mask 50. Then, the photoresist mask 50 and the part of the metal layer 30 covering the photoresist mask 50 are removed to form the metal retaining wall 204 as shown in (c) of FIG. 16. The removed portion of the photoresist mask 50 forms the second opening 32 .
  • the opening area of the second opening 32 or the third opening 33 can be adjusted by controlling the parameters of the manufacturing process to achieve the purpose of adjusting the aperture ratio of the micro LED chip.
  • the aperture r i.e., the diameter r of the color conversion layer 205
  • the diameter r of the second opening 32 as shown in (c) of FIG. 16 can also be adjusted during the process of making the above metal retaining wall 204.
  • the width t of the metal retaining wall 204 (the width t is along the direction of the spacing between two adjacent micro LED devices 202) is adjusted so that the width t of the metal retaining wall 204, the aperture r of the second opening 32, and the aperture R of the first opening 31 (i.e., the diameter R of the micro LED device 202) satisfy the following formula: R ⁇ r ⁇ R+t.
  • the light for example, B light
  • the micro LED device 202 located in the first opening 31 can be completely or nearly completely incident on the second opening 32, thereby being absorbed by the color conversion layer located in the second opening 32, thereby improving the color conversion efficiency and increasing the overall energy utilization efficiency of the device.
  • the aperture r of the second opening 32 needs to be less than or equal to the sum of the aperture R of the first opening 31 and the width t of the metal retaining wall 204.
  • R 100 ⁇ m, t ⁇ 2 ⁇ m, r ⁇ R+t.
  • the depth h of the second opening 32 as shown in (c) of FIG. 16 is set.
  • the depth h of the second opening 32 that is, the thickness h of the color conversion layer
  • the light (such as B light) at various angles emitted by the micro LED device 202 can be completely or nearly completely absorbed by the color conversion layer in the second opening 32, thereby improving the conversion efficiency of the color conversion layer.
  • the depth h of the second opening 32 can be 0.5 ⁇ m, 10 ⁇ m, 30 ⁇ m, 40 ⁇ m or 50 ⁇ m.
  • the depth of the second opening 32 is the thickness of the metal retaining wall 204 plus the thickness of the inorganic mask layer 51.
  • the depth of the second opening 32 is the thickness of the metal retaining wall 204.
  • a color conversion layer 205 needs to be formed in the second opening 32.
  • the color conversion layer 205 may include the quantum dot material as described above. Since metal retaining walls 204 are spaced between adjacent second openings 32 . When the semiconductor quantum dot material contacts the metal material, it is a Schottky contact. A Schottky barrier is formed at the interface of the two materials, so that the photoexcited electron charge of the corresponding quantum dot is transferred to the metal, affecting the luminous efficiency of the quantum dot, thereby reducing the light conversion efficiency of the color conversion layer.
  • the micro LED chip may also include a plurality of transparent medium protective layers 60 as shown in FIG. 17A .
  • a transparent medium protective layer 60 is located in a second opening 32 and covers the side wall of the second opening 32 .
  • a transparent medium protective layer 60 is arranged around a color conversion layer 205 and contacts the color conversion layer 205 . In this way, the metal retaining wall 204 and the color conversion layer 205 can be physically isolated by the transparent medium protective layer 60, eliminating the charge transfer between the quantum dot and the metal interface.
  • a transparent dielectric thin film layer can be deposited on the side wall of the metal retaining wall 204 in the second opening 32 by atomic layer deposition (ALD), hybrid physical chemical vapor deposition (HPCVD), plasma enhanced chemical vapor deposition (PECVD) or inductively coupled plasma chemical vapor deposition (ICP-CVD), so as to form a transparent dielectric protective layer 60 as shown in FIG. 17A .
  • ALD atomic layer deposition
  • HPCVD hybrid physical chemical vapor deposition
  • PECVD plasma enhanced chemical vapor deposition
  • ICP-CVD inductively coupled plasma chemical vapor deposition
  • the material of the transparent dielectric protection layer 60 may include at least one of dielectric films such as Al2O3 (aluminum oxide), AlN (aluminum nitride), SiO2 (silicon dioxide), SiNx (silicon nitride), HfO2 (hafnium oxide), SiCN (silicon carbon nitride), and SiON (silicon oxynitride).
  • dielectric films such as Al2O3 (aluminum oxide), AlN (aluminum nitride), SiO2 (silicon dioxide), SiNx (silicon nitride), HfO2 (hafnium oxide), SiCN (silicon carbon nitride), and SiON (silicon oxynitride).
  • the second opening 32 formed with the transparent medium protective layer 60 may be filled with a color conversion layer 205.
  • the color conversion layer 205 covers the micro LED device 202, and is used to convert the color of the light emitted by the micro LED device 202.
  • the vertical projection of one color conversion layer 205 on the substrate 201 completely overlaps with the vertical projection of one micro LED device 202 on the substrate 201, so that each micro LED device 202 may be covered with one color conversion layer 205 above the light emitting surface.
  • the color conversion layer 205 may be filled in the second opening 32 by inkjet printing, spin coating, drop coating, and quantum dot-photoresist (QD-PR) lithography.
  • the filling thickness of the color conversion layer 205 may be consistent with the depth of the second opening 32 to improve the absorption rate of the color conversion layer 205 to the light emitted by the micro LED device 202, thereby improving the conversion efficiency of the color conversion layer 205.
  • the material of the color conversion layer 205 is the same as described above and will not be repeated here.
  • the shape and curvature of the upper surface of the color conversion layer 205 can be adjusted.
  • the upper surface of the color conversion layer 205 can be flush with the upper surface of the metal retaining wall 204.
  • the micro LED chip 20 includes a mask structure 52 as shown in FIG. 17B
  • the upper surface of the color conversion layer 205 can be flush with the upper surface of the mask structure 52, so that the third opening 33 on the mask structure 52 can expose the color conversion layer 205.
  • FIG. 17A the parameters such as the inkjet printing QD ink solvent or the spin coating rate in the spin coating process
  • the upper surface of the color conversion layer 205 can be recessed downward (toward the substrate 201).
  • the upper surface of the color conversion layer 205 can be convex upward (away from the substrate 201).
  • the upper surface of the color conversion layer 205 is convex upward or downward, so that the surface can form a convex upward or convex downward interface composed of high-refractive material and low-refractive material, thereby forming a lens-like focusing or diffusing effect.
  • the conductive property of the metal retaining wall 204 can be used to adopt an electrochemical deposition process to deposit the color conversion layer 205 in the second opening 32 as shown in FIG17A, or in the second opening 32 and the third opening 33 as shown in FIG17B.
  • the metal retaining wall 204 formed with the shading structure 203, the micro LED device 202, and the second opening 32 is placed in an aqueous solution or a polar solution of quantum dots, and the surface ligands of the quantum dots in the solution are charged by polar ligand exchange, and the quantum dots corresponding to the polar ligands can be dissolved in the above-mentioned polar organic solvent or aqueous solution.
  • a voltage is applied to the metal retaining wall 204, and quantum dots are deposited on the transparent electrode 206 or the second electrode 222 of the thin layer LED device 202 (as shown in FIG. 4 ) through an electrochemical deposition process, thereby forming the color conversion layer 205 in the second opening 32 (as shown in FIG. 17B ).
  • the polar ligand may be an ammonium ion, and the quantum dots (QD) modified by the ammonium ion may be positively charged as shown in FIG18. Based on this, a negative voltage is applied to the metal retaining wall 204, and the solution is adjusted to be acidic, so that the quantum dots can be deposited in the second opening 32 to form a color conversion layer 205 (as shown in FIG17B).
  • the polar ligand may be a carboxylate/thiol ion, and the quantum dots modified by the carboxylate/thiol ion may be negatively charged.
  • a positive voltage is applied to the metal retaining wall 204, and the solution is adjusted to be alkaline, so that the quantum dots can be deposited in the second opening 32 to form a color conversion layer 205 (as shown in FIG17B).
  • the above is merely an example of forming a color conversion layer 205 using an electrochemical deposition process, and does not constitute a limitation on the electrochemical deposition process.
  • the parameters of the electrochemical process can be adjusted to achieve control of the thickness and filling density of the color conversion layer 205, thereby improving the filling uniformity of the color conversion layer 205 in the second opening 32, thereby improving the integration of the manufacturing process.
  • a metal retaining wall 204 and a flat layer 61 on the surface of the color conversion layer 205 away from the substrate 201 are formed on the substrate 201 on which the color conversion layer 205 is made.
  • the flat layer 61 is used to flatten the upper surface of the micro LED chip 20, thereby facilitating the preparation of subsequent film layers, such as an encapsulation layer.
  • a packaging layer 62 is formed to cover the side of the flat layer 61 away from the substrate 201.
  • the packaging layer can form a packaging space with the substrate 201 to isolate the damage of water and oxygen to the device and the corrosion of the quantum dots.
  • the packaging space is used to accommodate components such as the light shielding structure 203, the micro LED device 202, the metal retaining wall 204, and the color conversion layer 205.
  • the material of the encapsulation layer 62 includes but is not limited to resin materials, such as photosensitive (UV) glue, polymethyl methacrylate (PMMA) materials, etc., or inorganic materials, such as SiO2, SiNx, Al2O3, AlN, TiO2 (titanium dioxide), etc.
  • resin materials such as photosensitive (UV) glue, polymethyl methacrylate (PMMA) materials, etc.
  • inorganic materials such as SiO2, SiNx, Al2O3, AlN, TiO2 (titanium dioxide), etc.
  • the encapsulation layer 62 can effectively block water and oxygen, thereby protecting the micro LED device 202 located in the encapsulation space.
  • a microlens array is formed on a surface of the encapsulation layer 62 away from the substrate 201.
  • the microlens array may include a plurality of micro-lenses 63, and one micro-lens 63 may cover one micro LED device 202.
  • the light emitted by the micro LED device 202 is incident on the micro-lens 63 covering the micro LED device 202 after the color conversion by the color conversion layer 205, so that the incident light is adjusted by the micro-lens 63 to converge or diffuse the incident light before being emitted.
  • the metal retaining wall 204 can prevent the micro LED device from The light emitted by the micro LED device 202 is incident on the adjacent color conversion layer 205, thereby effectively reducing light crosstalk.
  • the metal retaining wall 204 can be formed by only performing a patterning process on the metal retaining wall 204, thereby reducing the steps of the manufacturing process.
  • the metal retaining wall 204 has good thermal conductivity, which can improve the heat dissipation effect of the micro LED chip 20.
  • the shape of the cross section of the metal retaining wall 204 (the cross section is perpendicular to the substrate 201) can be adjusted to form a reflective cup structure.
  • the opening rate of the pixel light-emitting unit (a color conversion layer 205 and the micro LED device 202 corresponding to its position) and the quantum dot absorption ratio of the color conversion layer 205 can be adjusted to improve the light extraction efficiency of the micro LED device 202 and the conversion efficiency of the color conversion layer 205.
  • the second electrode 222 of the micro LED device 202 can be formed at the bottom of the second opening 32, and by controlling the thickness of the second electrode 222, an optical resonant cavity is formed between the first electrode 212 and the second electrode 222 of the micro light-emitting device 202 to reduce light loss, thereby achieving the purpose of improving the vertical light extraction efficiency of the micro LED device 202.
  • the color conversion layer 205 can be formed in the second opening 32 by an electrochemical deposition process, so that the thickness and filling density of the color conversion layer 205 can be controlled.
  • each micro LED device 202 in the micro LED chip 20 can emit B light
  • the color conversion layer 205 corresponding to the position of each micro LED device 202 is a red light quantum dot color conversion layer, which can convert the B light emitted by the micro LED device 202 into R light, so that the entire micro LED chip 20 emits R light. Since the above micro LED chip 20 has high light emission efficiency and a small light emission angle, the light emission shape of the R light emitted by the micro LED chip 20 can be effectively narrowed.
  • the display screen prepared by the above micro LED chip 20 that emits R light has higher color purity, can obtain a wider color gamut, and the light emission shape is narrowed, and the light intensity of R light is effectively improved.
  • the above description is based on the fact that the display module 10 adopts the structure shown in FIG. 2B, and a single micro LED chip 20 in the display module 10 can emit one of the three primary colors, such as R light.
  • the above single micro LED chip 20 can also emit G light or B light.
  • each micro LED device 202 in the micro LED chip 20 can emit B light
  • the color conversion layer 205 corresponding to the position of each micro LED device 202 is a green light quantum dot color conversion layer, which can convert the B light emitted by the micro LED device 202 into G light, so that the entire micro LED chip 20 emits G light.
  • each micro LED device 202 in the micro LED chip 20 can emit B light
  • the color conversion layer 205 corresponding to the position of each micro LED device 202 is a transparent medium layer, so that the entire micro LED chip 20 emits B light.
  • the display module 10 in this example needs to integrate the monochrome micro LED chip 20 that can emit three primary colors on the same circuit board, and as shown in Figure 2B, the light of different colors emitted by three adjacent micro LED chips 20 are mixed (combined) and displayed as a pixel of the above-mentioned display module.
  • the micro LED chip 20 of this example can emit three primary colors of light at the same time, for example, it can emit R light, B light and G light at the same time.
  • the micro LED chip 20 is a full-color micro LED chip 20, and can be used as a full-color pixel in the display module shown in FIG. 2C, so that the display module can achieve full-color display.
  • the structure of the micro LED chip 20 is described below by way of example.
  • the micro LED chip 20 may include a substrate 201 and at least three micro LED devices 202 electrically connected to the substrate 201.
  • the three micro LED devices 202 are respectively located in three first openings 31 adjacent to each other.
  • Each micro LED device 202 is used to emit initial light.
  • the structure of the micro LED device 202 is the same as that of Example 1 and is not repeated here.
  • the micro LED chip 20 can be bound to the circuit board 100 through the substrate 201 and electrically connected to the driving circuit in the circuit board 100.
  • the driving circuit can be used to control the opening and closing of a single micro LED device 202.
  • the plurality of, for example, three, color conversion layers in the micro LED chip 20 may include at least: a first color conversion layer 205a, The second color conversion layer 205b and the third color conversion layer 205c.
  • the first color conversion layer 205a, the second color conversion layer 205b and the third color conversion layer 205c are sequentially located in three adjacent second openings 32 and respectively cover three adjacent micro LED devices 202.
  • the first color conversion layer 205a is used to receive the initial light emitted by the micro LED device 202 covered by the first color conversion layer 205a, and perform color conversion on the initial light to output the first visible light.
  • the second color conversion layer 205b is used to receive the initial light emitted by the micro LED device 202 covered by it, and output the second visible light.
  • the third color conversion layer 205c is used to receive the initial light emitted by the micro LED device 202 covered by it, and output the third visible light.
  • the first visible light, the second visible light and the third visible light are three primary color lights, for example, the first visible light is R light, the second visible light is G light, and the third visible light is B light.
  • the initial light emitted by the micro LED device 202 of the full-color micro LED chip 20 may be B light.
  • the first color conversion layer 205a and the second color conversion layer 205b include quantum dot materials.
  • the quantum dot materials are the same as those in Example 1 and are not described in detail here.
  • the first color conversion layer 205a can be a red light quantum dot color conversion layer (abbreviated as R-QD in the figure), and the red light quantum dot color conversion layer can convert the B light emitted by the micro LED device 202 into R light.
  • the second color conversion layer 205b is a green light quantum dot color conversion layer (abbreviated as G-QD in the figure), and the green light quantum dot color conversion layer can convert the B light emitted by the micro LED device 202 into G light.
  • G-QD green light quantum dot color conversion layer
  • the third color conversion layer 205c is a light-transmitting structure, that is, it can transmit the B light emitted by the micro LED device 202 covered by the third color conversion layer 205c, so that the pixel light-emitting unit composed of the third color conversion layer 205c and the micro LED device 202 covered by it can emit B light.
  • the third color conversion layer 205c can include a transparent resin material.
  • the third color conversion layer 205c can include a mixture of a transparent resin material and scattering particles, so as to achieve a uniform light effect by scattering the light through the scattering particles.
  • the initial light emitted by the micro LED device 202 of the above-mentioned full-color micro LED chip 20 can be ultraviolet light (UV), and the micro LED device emitting ultraviolet light is referred to as UV ⁇ -LED in the accompanying drawing.
  • UV ultraviolet light
  • the first color conversion layer 205a, the second color conversion layer 205b and the third color conversion layer 205c include quantum dot materials.
  • the quantum dot materials are the same as those in Example 1 and are not described in detail here.
  • the first color conversion layer 205a can be a red light quantum dot color conversion layer (abbreviated as R-QD in the figure), and the red light quantum dot color conversion layer can convert the ultraviolet light emitted by the micro LED device 202 into R light.
  • the second color conversion layer 205b is a green light quantum dot color conversion layer (abbreviated as G-QD in the figure), and the green light quantum dot color conversion layer can convert the ultraviolet light emitted by the micro LED device 202 into G light.
  • the third color conversion layer 205c can also be a blue light quantum dot color conversion layer (abbreviated as B-QD in the figure), and the blue light quantum dot color conversion layer can convert the ultraviolet light emitted by the micro LED device 202 into B light.
  • the first color conversion layer 205a and the micro LED device 202 covered by the first color conversion layer 205a constitute an R pixel for emitting R light.
  • the second color conversion layer 205b and the micro LED device 202 covered by the second color conversion layer 205b constitute a G pixel for emitting G light.
  • the third color conversion layer 205c and the micro LED device 202 covered by the third color conversion layer 205c constitute a B pixel for emitting B light.
  • RGB pixel integration can be achieved in a single micro LED chip 20.
  • the arrangement of the RGB pixels can be Pentile pixel arrangement (also called P arrangement), Delta pixel arrangement (also called D arrangement) and diamond arrangement, etc., as described above, and this application does not limit this.
  • the above solution can be well integrated with the micro LED device and the CMOS driving circuit in the circuit board.
  • micro LED chip shown in Figure 21 since the ultraviolet light emitted by each micro LED device 202 is invisible, the problem of light leakage of the micro LED device 202 emitting B light can be solved compared with the micro LED device 202 emitting B light, so that the micro LED chip shown in Figure 21 can obtain higher visible light color purity and improve the display effect.
  • the following is a detailed description of the method for preparing the micro LED chip by taking the structure of the micro LED chip shown in FIG20 as an example.
  • the method for preparing the micro LED chip is shown in FIG22 and may include S201 to S204.
  • a metal layer 30 is formed on a substrate 201 on which a micro LED device 202 emitting B light and a light shielding structure 203 are prepared.
  • the material, thickness and beneficial effects of the metal layer 30 are the same as those in Example 1, and will not be described in detail here.
  • the metal layer has a plurality of pixel regions, including a first sub-pixel region (corresponding to the position of the R pixel), a second sub-pixel region (corresponding to the position of the G pixel) and a third sub-pixel region (corresponding to the position of the B pixel).
  • a second opening 32 is formed on the metal layer 30 at the first sub-pixel region (corresponding to the position where the R pixel is located) and penetrates the metal layer 30.
  • the method for forming the above second opening 32 and the beneficial effects are the same as those in Example 1, and will not be described again here.
  • the first color conversion layer 205a is filled in the second opening 32 of the first sub-pixel region (corresponding to the location of the R pixel).
  • the first color conversion layer 205a receives the B light emitted by the micro LED device 202 covered by it, and outputs the first visible light, such as R light.
  • the first color conversion layer 205a and the micro LED device 202 covered by the first color conversion layer 205a constitute an R pixel for emitting R light.
  • a second opening 32 is formed on the metal layer 30 at the second sub-pixel region (corresponding to the position where the G pixel is located) and penetrates the metal layer 30.
  • the method for forming the second opening 32 and the beneficial effects are the same as those in Example 1, and will not be described in detail here.
  • the second color conversion layer 205b is filled in the second opening 32 of the second sub-pixel region (corresponding to the location of the G pixel).
  • the second color conversion layer 205b receives the B light emitted by the micro LED device 202 covered by it, and outputs a second visible light, such as G light.
  • the second color conversion layer 205b and the micro LED device 202 covered by the second color conversion layer 205b constitute a G pixel for emitting G light.
  • a second opening 32 is formed on the metal layer 30 at the third sub-pixel region (corresponding to the position where the B pixel is located) and penetrates the metal layer 30.
  • the method for forming the second opening 32 and the beneficial effects are the same as those in Example 1, and will not be described in detail here.
  • the third color conversion layer 205c shown in FIG. 20 is filled in the second opening 32 of the third sub-pixel region (corresponding to the position where the B pixel is located), such as the above-mentioned transparent resin material, or a mixture of the transparent resin material and scattering particles.
  • the third color conversion layer 205c receives the B light emitted by the micro LED device 202 covered by it, and outputs a third visible light, such as B light.
  • the third color conversion layer 205c and the micro LED device 202 covered by the third color conversion layer 205c constitute a B pixel for emitting B light.
  • the method for manufacturing FIG. 21 is the same as S201 to S203.
  • S204 is executed, after the step of forming a second opening 32 penetrating the metal layer 30 in the third sub-pixel region (corresponding to the position where the B pixel is located) on the metal layer 30, it is necessary to fill the second opening 32 in the third sub-pixel region (corresponding to the position where the B pixel is located) with a quantum dot material as shown in FIG. 21 to form a third color conversion layer 205c for converting UV light into B light.
  • the preparation method of the full-color micro LED chip provided in Example 2 compared with the micro LED chip for emitting monochromatic light provided in Example 1, only needs to add two pixel preparation processes (each pixel preparation process includes forming the second opening 32 and filling the color conversion layer in the second opening), that is, the RGB pixel integration in a single micro LED chip 20 can be realized.
  • the metal layer 30 shown in FIG. 20 is still used to separate two adjacent color conversion layers in the full-color micro LED chip.
  • the structural dimensions and beneficial effects of the metal retaining wall, as well as the structural dimensions and beneficial effects of the second opening 32 are the same as those described in Example 1, and will not be repeated here.
  • the full-color micro LED chip 20 provided in this example can also be prepared by the electrochemical deposition method shown in FIG18.
  • the above-mentioned R pixel, B pixel and G pixel can be prepared in sequence three times.
  • the method for preparing any one of the above-mentioned R pixel, B pixel and G pixel can include forming the above-mentioned metal retaining wall 204 by photolithography and etching processes, and then using the above-mentioned electrochemical deposition process to perform electrochemical deposition of quantum dots in the opening surrounded by the metal retaining wall 204, so as to realize R/G/B three-color integrated MD device.
  • the above-mentioned preparation method can realize the integration of R pixels, B pixels and G pixels in a single micro LED chip 20, thereby realizing the full-color display of the display module, which is conducive to expanding the application prospects of the full-color LED chip 20.

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Abstract

Les modes de réalisation de la présente demande relèvent du domaine technique des puces. L'invention propose une puce de microdiode électroluminescente (DEL) et son procédé de fabrication, et un module d'affichage et un terminal, qui sont utilisés pour améliorer le phénomène de diaphonie de lumière d'un écran d'affichage à micro-DEL. La puce à micro-DEL comprend un substrat, une structure de protection contre la lumière, une pluralité de dispositifs à micro-DEL, des parois de retenue métalliques et une pluralité de couches de conversion de couleur, la pluralité de dispositifs à micro-DEL étant électriquement connectée au substrat ; la structure de protection contre la lumière est située entre des dispositifs à micro-DEL adjacents ; une couche de conversion de couleur recouvre un dispositif à micro-DEL ; et les parois de retenue métalliques sont situées entre des couches de conversion de couleur adjacentes, et peuvent empêcher la lumière émise par les dispositifs à micro-DEL d'être incidente sur les couches de conversion de couleur adjacentes, de façon à réduire la diaphonie de lumière. Les parois de retenue métalliques peuvent en outre permettre à davantage de lumière, qui provient des dispositifs à micro-DEL et est incidente sur les couches de conversion de couleur, d'être soumise à une conversion de couleur, ce qui permet d'améliorer l'efficacité de conversion des couches de conversion de couleur.
PCT/CN2023/120851 2022-10-25 2023-09-22 Puce à micro-del et son procédé de fabrication, et module d'affichage et terminal WO2024087973A1 (fr)

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CN202211313835.3A CN117976689A (zh) 2022-10-25 2022-10-25 一种微型led芯片及其制作方法、显示模组、终端

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Citations (4)

* Cited by examiner, † Cited by third party
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WO2020258898A1 (fr) * 2019-06-25 2020-12-30 成都辰显光电有限公司 Panneau d'affichage, dispositif d'affichage et procédé de fabrication de panneau d'affichage
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