WO2024120185A1 - Led显示设备 - Google Patents

Led显示设备 Download PDF

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Publication number
WO2024120185A1
WO2024120185A1 PCT/CN2023/133010 CN2023133010W WO2024120185A1 WO 2024120185 A1 WO2024120185 A1 WO 2024120185A1 CN 2023133010 W CN2023133010 W CN 2023133010W WO 2024120185 A1 WO2024120185 A1 WO 2024120185A1
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WO
WIPO (PCT)
Prior art keywords
layer
electrode
display device
reflective
led display
Prior art date
Application number
PCT/CN2023/133010
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English (en)
French (fr)
Inventor
蒋振宇
Original Assignee
苏州秋水半导体科技有限公司
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Publication of WO2024120185A1 publication Critical patent/WO2024120185A1/zh

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Classifications

    • 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
    • H01L33/36—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 electrodes
    • H01L33/38—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 electrodes with a particular shape
    • 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
    • H01L33/36—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 electrodes
    • H01L33/40—Materials therefor
    • 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
    • H01L33/44—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 coatings, e.g. passivation layer or anti-reflective coating
    • H01L33/46—Reflective coating, e.g. dielectric Bragg reflector
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00

Definitions

  • the present application relates to display technology, and in particular to LED display devices.
  • Micro-LED technology is a technology that miniaturizes and matrices traditional LEDs. It first miniaturizes traditional large-size LED chips to micron-level Micro-LED chips, and then matrices them into high-density integrated LED arrays. In this way, each display pixel in the display screen that uses Micro-LED technology can be independently positioned and lit, thereby achieving precise control of each Micro-LED chip and realizing the display function.
  • the size effect caused by miniaturizing the Micro-LED chip to the micron level affects the light output efficiency of the LED display device.
  • the size of the Micro-LED is reduced, the light emission of the side wall is enhanced, making the output light angle of the LED display device not collimated enough.
  • the embodiments of the present application provide an LED display device, which can realize collimated light emission of the LED display device and improve the collimation of the emitted light.
  • a technical solution adopted by the present application is to provide an LED display device, the LED display device includes a display substrate, the display substrate includes:
  • An epitaxial layer comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, wherein the second semiconductor layer is provided with a first recessed region on a side away from the active layer, and a plurality of spaced-apart convex structures are defined by the first recessed region on a side of the second semiconductor layer away from the active layer, wherein a depth of the first recessed region is less than or equal to a layer thickness of the second semiconductor layer;
  • a common electrode layer, the common electrode layer is filled in the first recessed area and contacts the side walls of the plurality of boss structures, and the common electrode layer further exposes the top walls of the boss structures;
  • a plurality of reflective electrode patterns are arranged at intervals on a side of the first semiconductor layer away from the active layer and correspond to a plurality of boss structures respectively, wherein the reflectivity of the reflective layer is less than the reflectivity of the reflective electrode pattern to form a resonant cavity that emits light from one side of the reflective layer.
  • the present application arranges a plurality of boss structures and a first recessed area on the epitaxial layer, and fills the first recessed area with a common electrode layer, so that the common electrode layer separates the plurality of boss structures, and a reflective layer is arranged on one side of the boss structure and faces away from a plurality of reflective electrode patterns, wherein the reflectivity of the reflective layer is less than the reflectivity of the reflective electrode pattern, so as to form a resonant cavity that emits light from one side of the reflective layer, thereby realizing collimated light emission of the LED display device and improving the collimation of the emitted light.
  • FIG1 is a schematic structural diagram of an embodiment of an LED display device of the present application.
  • FIG2 is a schematic diagram of the component structure of an embodiment of an LED display device of the present application.
  • FIG3 is a schematic diagram of light emission effect of an embodiment of an LED display device without a resonant cavity
  • FIG4 is a schematic diagram of light emission effect of an embodiment of an LED display device with a resonant cavity
  • FIG5 is a schematic diagram of a process of an embodiment of a method for manufacturing an LED display device of the present application
  • FIG6 is a schematic diagram of a preparation process corresponding to the manufacturing method of the LED display device shown in FIG5 ;
  • FIG7 is a schematic diagram of another preparation process corresponding to the manufacturing method of the LED display device shown in FIG5 ;
  • FIG8 is a schematic flow chart of an embodiment of a method for manufacturing a resonant cavity in an LED display device of the present application
  • FIG9 is a schematic diagram of a preparation process corresponding to the manufacturing method of the resonant cavity in the LED display device shown in FIG8 ;
  • FIG10 is a schematic flow chart of an embodiment of a method for manufacturing a wavelength conversion layer and a color filter layer of the present application
  • FIG11 is a schematic diagram of a preparation process corresponding to the method for manufacturing the wavelength conversion layer and the color filter layer shown in FIG10 ;
  • FIG12 is a schematic diagram of a process of manufacturing a color filter layer according to an embodiment of the present invention.
  • FIG13 is a schematic diagram of a preparation process corresponding to the method for manufacturing the color filter layer shown in FIG12 ;
  • FIG. 14 is a partial structural diagram of another embodiment of the LED display device of the present application.
  • FIG15 is a schematic diagram of a process of another embodiment of a method for manufacturing a color filter layer of the present application.
  • FIG16 is a schematic diagram of a preparation process corresponding to another embodiment of the method for manufacturing the color filter layer shown in FIG15 ;
  • FIG. 17 is a schematic structural diagram of another embodiment of the LED display device of the present application.
  • LED display device embodiments of the present application describe an exemplary structure of an LED display device.
  • the LED display device 10 includes a display substrate 100, a driving substrate 200, and a common wiring 300.
  • the display substrate 100 is used to form a pixel structure of the LED display device 10
  • the driving substrate 200 is used to form a driving structure of the LED display device 10
  • the common wiring 300 is used to electrically connect the display substrate 100 and the driving substrate 200.
  • the display substrate 100 includes an epitaxial layer 110 , a common electrode layer 120 , a reflective layer 130 and a plurality of reflective electrode patterns 140 .
  • the epitaxial layer 110 is used to emit light through the recombination of electrons and holes, and defines a plurality of display pixels (described below).
  • the common electrode layer 120 can be used as the N electrode of the LED display device 10 to supply power to the epitaxial layer 110, and as a common electrode for supplying power to the plurality of display pixels, and the common wiring 300 electrically connects the common electrode layer 120 and the drive substrate. 200.
  • the reflective layer 130 is disposed on the top layer of the epitaxial layer 110 and the common electrode layer 120, and is used to partially transmit the light emitted from the epitaxial layer 110, and partially reflect the light emitted from the epitaxial layer 110.
  • a plurality of reflective electrode patterns 140 are disposed at intervals on the side of the epitaxial layer 110 facing away from the reflective layer 130, and are used to reflect the light emitted from the epitaxial layer 110, and can also serve as the P electrode of the LED display device 10 to supply power to the epitaxial layer 110, and as the pixel electrode to supply power to the above-mentioned plurality of display pixels respectively.
  • the common electrode layer 120 , the reflective layer 130 and the plurality of reflective electrode patterns 140 can all reflect the light emitted from the epitaxial layer 110 , and the reflectivity of the reflective layer 130 is lower than that of the reflective electrode patterns 140 , so as to form a resonant cavity 101 with light emitted from one side of the reflective layer 130 .
  • the epitaxial layer 110 includes a first semiconductor layer 111, an active layer 112, and a second semiconductor layer 113, which are stacked in sequence.
  • the first semiconductor layer 111 and the second semiconductor layer 113 are P-type and N-type semiconductor layers, respectively, and the first semiconductor layer 111 and the second semiconductor layer 113 are doped in semiconductor materials such as AlN, AlGaN, GaN, InGaN, AlInGaN, GaAs, GaP, GaInN, GaAsP, AlGaAs, and AlGaInP, respectively.
  • the active layer 112 is a working medium layer, and the active layer 112 may be, for example, a multi-quantum well structure.
  • the second semiconductor layer 113 is provided with a first recessed area 114 on the side facing away from the active layer 112, and a plurality of spaced-apart convex structures 115 are defined on the side of the second semiconductor layer 113 facing away from the active layer 112 by the first recessed area 114.
  • the spaced-apart multiple convex structures 115 and the first semiconductor layer 111 and the active layer 112 thereunder can be used as display pixels of the LED display device 10.
  • the depth of the first recessed area 114 is less than or equal to the thickness of the second semiconductor layer 113 , that is, the depth of the first recessed area 114 does not reach the active layer 112 , thereby preventing the active layer 112 from being damaged and causing non-luminescent recombination, thereby improving the light extraction efficiency of the LED display device 10 .
  • an insulating region (not shown) formed by ion bombardment is provided in the first semiconductor layer 111 and the active layer 112 corresponding to the bottom of the first recessed area 114, so that the first semiconductor layer 111 and the active layer 112 under the plurality of boss structures 115 are electrically isolated from each other in the epitaxial layer 110, and different currents input into each display pixel by the corresponding reflective electrode pattern 140 are diffused to other display pixels through the first semiconductor layer 111 and the active layer 112.
  • the thickness and resistivity of the first semiconductor layer 111 can be set first, so that when the LED display device 10 works normally, the lateral current diffusion length of the first semiconductor layer 111 satisfies Ls ⁇ 1/2 ⁇ D1, where Ls is the lateral current diffusion length of the first semiconductor layer 111, and D1 is the shortest distance between the edges of adjacent reflective electrode patterns 140.
  • the thickness and resistivity of the first semiconductor layer 111 By setting the thickness and resistivity of the first semiconductor layer 111, when the lateral current of the first semiconductor layer 111 diffuses, it will not affect the lateral current diffusion of the first semiconductor layer 111 corresponding to the adjacent reflective electrode pattern 140. In other words, the working current of the display pixel corresponding to each reflective electrode pattern 140 will not diffuse to the adjacent display pixel.
  • the active layer 112 corresponding to each reflective electrode pattern 140 can be independently controlled to emit light, so that the self-isolation of each display pixel can be achieved on a large-size LED chip by adjusting the lateral current diffusion length, thereby improving the reliability and yield of the LED display device 10 and reducing the probability of leakage. Moreover, the realization of self-isolation can simplify the chip process flow and reduce production costs.
  • the common electrode layer 120 fills the first recessed area 114 and contacts the sidewalls of the plurality of boss structures 115 , and the common electrode layer 120 exposes the top walls of the boss structures 115 .
  • the common electrode layer 120 surrounds the plurality of boss structures 115 and makes full surrounding contact with the side walls of the plurality of boss structures 115, so that the light in the epitaxial layer 110 will not be transmitted through the side walls of the boss structures 115 to other boss structures 115, thereby causing light crosstalk.
  • the common electrode layer 120 remains interconnected in the spacing area between the plurality of boss structures 115, so as to serve as a common electrode for a plurality of display pixels, and can achieve good current diffusion when the LED display device 10 is connected to the operating voltage, and can provide current to the epitaxial layer 110 so that the epitaxial layer 110 can emit light in a composite manner.
  • the common electrode layer 120 includes a first metal electrode layer 121 conformally attached to the sidewalls of the plurality of boss structures 115 and the bottom of the first recessed area 114, and a second metal electrode layer 123 filled in the second recessed area 122 formed by the first metal electrode layer 121.
  • the reflectivity of the first metal electrode layer 121 is greater than the reflectivity of the second metal electrode layer 123.
  • the first metal electrode layer 121 is used to conduct current to the boss structure 115 and reflect the light reflected from the boss structure 115 to the side wall, so as to improve the light extraction efficiency of the LED display device 10, so that the light between the multiple boss structures 115 will not crosstalk.
  • the second metal electrode layer 123 is used to supply power to the second semiconductor in the boss structure 115 by conducting current to the first metal electrode layer 121, so as to form a common electrode with the second semiconductor layer 113.
  • the reflectivity of the first metal electrode layer 121 By setting the reflectivity of the first metal electrode layer 121 to be greater than the reflectivity of the second metal electrode layer 123, the light generated by the boss structure 115 can be reflected back into the boss structure 115 to the greatest extent when it reaches the side wall of the boss structure 115 and the first metal electrode layer 121, thereby reducing the loss of light propagating in the first metal electrode layer 121, improving the light output efficiency of the LED display device 10, and reducing costs.
  • the first metal electrode layer 121 is an aluminum electrode layer. Using highly reflective aluminum as the material of the first metal electrode layer 121 can make the common electrode layer 120 have a better light reflection effect.
  • the second metal electrode layer 123 is a copper metal layer. Copper metal has good electrical conductivity and can improve the efficiency of current diffusion.
  • the first metal electrode layer 121 can also be a metal layer formed by doping multiple metal layers of titanium, chromium, etc. and aluminum, and the second metal electrode layer 123 can be other conductive materials. The materials of the first metal electrode layer 121 and the second metal electrode layer 123 are not limited here.
  • the side of the common electrode layer 120 facing away from the active layer 112 is arranged to be flush with the top wall of the boss structure 115, and form a continuous plane.
  • the reflective layer 130 covers the top wall of the boss structure 115 and the common electrode layer 120, so that the reflective layer 130 can reflect the light emitted from the top wall of the boss structure 115, and the reflective layer 130 completely covers the top wall of the boss structure 115 and the continuous plane formed by the common electrode layer 120, so that the covering process of the reflective layer 130 is simpler.
  • the reflective layer 130 can be a metal aluminum layer, or a reflective layer 130 made of other materials such as a DBR reflector that has the ability to reflect light.
  • a plurality of reflective electrode patterns 140 may be spaced apart on a side of the first semiconductor layer 111 away from the active layer 112 and correspond to a plurality of boss structures 115, respectively, wherein the reflectivity of the reflective layer 130 is less than the reflectivity of the reflective electrode pattern 140, so that light in the plurality of boss structures 115 can be reflected back after reaching the reflective electrode pattern 140 and the first metal electrode layer 121 of the side wall, so as to form a resonant cavity 101 that emits light from one side of the reflective layer 130, thereby improving the collimation of light emitted by the LED display device 10.
  • Figure 3 shows the light emission effect of the LED display device 10 without the resonant cavity 101
  • Figure 4 shows the light emission effect of the LED display device 10 after the resonant cavity 101 is set.
  • the light emission effect of the LED display device 10 without the resonant cavity 101 is a Lambertian type with a scattered light emission angle
  • the LED display device 10 after the resonant cavity 101 is set changes the Lambertian type light emission into vertical axial light emission, concentrates the light emission angle, improves the collimation of the light emission, and realizes collimated light emission.
  • the display substrate 100 may further include a wavelength conversion layer 150 disposed on the side of the reflective layer 130 away from the epitaxial layer 110 and a color filter layer 160 disposed on the side of the wavelength conversion layer 150 away from the epitaxial layer 110.
  • the wavelength conversion layer 150 is used to convert the first light output from the top wall of the boss structure 115 into the second light
  • the color filter layer 160 includes a plurality of color filter patterns 161 respectively disposed corresponding to the plurality of boss structures 115, and the color filter patterns 161 are used to filter the second light into a third light, and the colors of the third light formed by at least some of the color filter patterns 161 are different from each other.
  • the wavelength conversion layer 150 is disposed on the side of the reflective layer 130 away from the epitaxial layer 110 in a manner of full coverage, and the color filter pattern 161 is formed on the side of the wavelength conversion layer 150 away from the epitaxial layer 110 by a development process, thereby forming the color filter layer 160 .
  • the development process is to first use a semiconductor photoresist to cover a layer of color photoresist layer, then expose the color photoresist layer at a specified position, and further remove the color resist layer of other parts by a developer to achieve patterning of the color filter pattern 161 at the specified position, and finally form a color filter layer 160 by baking and curing.
  • the wavelength conversion layer 150 may be made of a quantum dot material with a certain color, so that the first light output from the top wall of the boss structure 115 can be superimposed with the corresponding color in the wavelength conversion layer 150 when passing through the wavelength conversion layer 150, and then the second light output by the wavelength conversion layer 150 is mixed with the color of the wavelength conversion layer 150 to form a mixed color.
  • the wavelength conversion layer 150 may be formed by stacking multiple sub-wavelength conversion layers of different colors, so as to output a second light of multiple colors.
  • the wavelength conversion layer 150 may also be a single-layer wavelength conversion layer 150 made by mixing quantum dot materials of multiple colors to achieve multiple color mixing.
  • the plurality of color filter patterns 161 may be filters with certain colors, and are disposed at positions corresponding to the plurality of boss structures 115 , and the light emitted from the plurality of boss structures 115 may be emitted through the plurality of color filter patterns 161 .
  • the color of the plurality of color filter patterns 161 may be one of the mixed colors of the second light.
  • the color filter pattern 161 may transmit the light of the color corresponding to the color filter pattern 161 itself in the second light, and filter the light of other colors, thereby converting the second light of the plurality of colors into a third light of only the color of the color filter pattern 161 itself.
  • At least some of the color filter patterns 161 are different from other color filter patterns 161, so that the third light passing through the plurality of color filter patterns 161 has different colors, so that each display pixel of the LED display device 10 can display different colors.
  • the wavelength conversion layer 150 can be a stack of a green sub-wavelength conversion layer and a red sub-wavelength conversion layer, or the wavelength conversion layer 150 can be a single-layer wavelength conversion layer 150 doped with green and red quantum dots, so that the wavelength conversion layer 150 converts the blue light of the first light into a second light of blue, green and red mixed colors.
  • the color filter layer 160 includes a plurality of blue, green and red color filter patterns 161, and the second light passes through the three color filter patterns 161 respectively. When the color filter pattern 161 filters the second light into a third light having a color corresponding to the color filter pattern 161, the LED display device 10 can display blue, green, and red lights.
  • the display substrate 100 may further include a first dielectric layer 170 and a first switching electrode 180 .
  • the first dielectric layer 170 covers a side of the first semiconductor layer 111 away from the active layer 112 and the reflective electrode pattern 140 .
  • the first dielectric layer 170 is provided with a first via hole 171 allowing the reflective electrode pattern 140 to be exposed.
  • the first switching electrode 180 is disposed in the first via hole 171 and is conductively connected to the reflective electrode pattern 140 .
  • the first dielectric layer 170 may be made of silicon dioxide or an oxide layer made of other insulating materials, which is used to fix the position of the first transfer electrode 180 and serve as a masking film and protective layer to prevent impurities from diffusing.
  • the first transfer electrode 180 may be made of metal copper or other conductive materials.
  • the driving substrate 200 may include a power supply substrate 210, a second dielectric layer 220, and a second transfer electrode 230.
  • the second dielectric layer 220 is provided with a second via hole 221, and the second transfer electrode 230 is provided in the second via hole 221.
  • the second dielectric layer 220 and the second transfer electrode 230 are directly provided on the power supply substrate 210, and present a damascene structure on the power supply substrate 210, and the first transfer electrode 180 may be electrically connected to the power supply substrate 210, so that the power supply substrate 210 can transfer current to the second transfer electrode 230.
  • the second dielectric layer 220 may also be an oxide layer made of silicon dioxide or other insulating materials to fix the position of the second transfer electrode 230 and serve as a masking film and protective layer to prevent impurities from diffusing.
  • the second transfer electrode 230 may be an electrode made of metal copper or other conductive materials.
  • the first dielectric layer 170 and the second dielectric layer 220 and the first transfer electrode 180 and the second transfer electrode 230 can be bonded by hot pressing, so that the first transfer electrode 180 and the second transfer electrode 230 and the first dielectric layer 170 and the second dielectric layer 220 are interconnected and integrated, thereby achieving a high-strength connection between the display substrate 100 and the driving substrate 200, so that the power supply substrate 210 can smoothly transfer current to the first semiconductor layer 111 in the epitaxial layer 110 through the first transfer electrode 180 and the second transfer electrode 230.
  • the first transfer electrode 180 may include a first electrode portion 181 close to the reflective electrode pattern 140 and a second electrode portion 182 away from the reflective electrode pattern 140
  • the second transfer electrode 230 includes a third electrode portion 231 close to the first transfer electrode 180 and a fourth electrode portion 232 away from the first transfer electrode 180.
  • the size of the first electrode portion 181 is smaller than the size of the second electrode portion 182
  • the size of the fourth electrode portion 232 is smaller than the size of the third electrode portion 231.
  • Such a configuration can increase the contact area of the surface where the first transfer electrode 180 and the second transfer electrode 230 are connected to each other, so as to improve the degree of fusion between the first transfer electrode 180 and the second transfer electrode 230, and achieve a higher strength connection.
  • a plurality of switching devices are arranged in an array on the power supply substrate 210, and each second transfer electrode 230 is electrically connected to a corresponding switching device, that is, the switching device corresponds to the reflective electrode pattern 140 one by one, so that the connected switching device provides a driving signal to the second transfer electrode 230, and the driving signal can sequentially pass through the second transfer electrode 230, the first transfer electrode 180 and the reflective electrode pattern 140 to reach the first semiconductor layer 111 of the epitaxial layer 110, thereby realizing individual control of the display pixels.
  • the LED display device 10 may further include a display substrate 100 and a drive substrate 200.
  • the common electrode layer 120 is electrically connected to the common wiring 300 of the driving substrate 200.
  • the common electrode layer 120 is exposed on the side of the display substrate 100, one end of the common wiring 300 is fixedly connected to the second metal electrode layer 123 in the common electrode layer 120, and the other end is connected to the substrate of the driving substrate 200, wherein the common wiring 300 can be fixedly connected to the common electrode layer 120 and the driving substrate 200 by wire bonding, so that the current provided by the driving substrate 200 can be transmitted to the common electrode layer 120 through the common wiring 300.
  • holes may be punched in the non-display pixel area of the display substrate 100 and the corresponding area of the driving substrate 200 , and then the common wiring 300 connects the common electrode layer 120 and the driving substrate 200 through the perforations.
  • the preparation process of the LED display device 10 is exemplarily described below.
  • some components of the display substrate 100 may be first fixed on the driving substrate 200 , and then some components of the display substrate 100 may be further processed to form the resonant cavity 101 .
  • Figures 5 to 7 the steps of the preparation and connection process of some components of the display substrate 100 and the drive substrate 200 are shown in Figures 5 to 7, wherein Figure 5 shows the preparation process of some components of the display substrate 100 and the process of bonding with the drive substrate 200, Figure 6 is a schematic diagram of a preparation process corresponding to the process steps S110-S130 shown in Figure 5, and Figure 7 is another schematic diagram of a preparation process corresponding to the process steps S140-S150 shown in Figure 5. In other embodiments, the following preparation process can be adjusted.
  • S110 providing an epitaxial layer.
  • the epitaxial layer 110 can be formed on the substrate 116 by growth, or fixed on the substrate 116 by transfer.
  • the epitaxial layer 110 is fixed on the substrate 116 in the form of the second semiconductor layer 113 facing the substrate 116.
  • the substrate 116 can be coated with adhesive in advance when contacting the epitaxial layer 110 to bond and fix the epitaxial layer 110.
  • S120 forming reflective electrode patterns arranged at intervals on a side of the first semiconductor layer away from the active layer.
  • a transparent electrode layer 1171 such as transparent electrode ITO
  • a transparent electrode layer 1171 can be covered on the surface of the first semiconductor layer 111 of the epitaxial layer 110 by an annealing process. After the annealing process, the transparent electrode layer 1171 can form an ohmic contact with the epitaxial layer 110. Then, after annealing, a metal electrode layer 1401 is covered on the surface of the transparent electrode layer 1171, and the transparent electrode layer 1171 and the metal electrode layer 1401 are etched to obtain a plurality of transparent electrodes 117 and a plurality of reflective electrode patterns 140. The spacing distance between the plurality of reflective electrode patterns 140 can be calculated according to the required display pixel distance of the LED display device 10.
  • ion bombardment may be performed on the spaced regions between the plurality of reflective electrode patterns 140 so that the epitaxial layers 110 corresponding to the spaced regions of the plurality of reflective electrode patterns 140 may form insulating regions, thereby achieving electrical isolation of the epitaxial layers 110 corresponding to the plurality of reflective electrode patterns 140 from each other to achieve independence between display pixels.
  • the thickness and resistivity of the first semiconductor layer 111 are set in advance in a manner of controlling the lateral current diffusion, so that when the LED display device 10 is operating normally, the lateral current diffusion length of the first semiconductor layer 111 satisfies Ls ⁇ 1/2 ⁇ D1, where Ls is the lateral current diffusion length of the first semiconductor layer 111, and D1 is the shortest spacing between the edges of adjacent reflective electrode patterns 140.
  • the first semiconductor layer 111 corresponding to the interval area between the plurality of reflective electrode patterns 140 may be etched first.
  • the etching depth does not exceed the thickness of the first semiconductor layer 111.
  • ion bombardment is performed on the spaced regions between the plurality of reflective electrode patterns 140, or the diffusion current of the first semiconductor layer 111 is controlled to further form an insulating region.
  • each display pixel can be isolated without damaging the active layer 112, thereby improving the reliability and yield of the LED display device 10 and reducing the probability of leakage.
  • S130 forming a first dielectric layer and a plurality of first switching electrodes.
  • the first electrode portion 181 faces the reflective electrode pattern 140, and the plurality of first transfer electrodes 180 are placed correspondingly on the side of the plurality of reflective electrode patterns 140 away from the epitaxial layer 110, so that the plurality of reflective electrode patterns 140 and the plurality of first transfer electrodes 180 are formed on the side of the epitaxial layer 110 away from the substrate 116 and arranged at intervals.
  • a first dielectric layer 170 is filled between the multiple reflective electrode patterns 140 and the multiple first transfer electrodes 180, wherein the first dielectric layer 170 extends beyond the second electrode portion 182 of the first transfer electrode 180 on the side facing away from the epitaxial layer 110 and beyond the top of the epitaxial layer 110, and through a chemical mechanical polishing (CMP) process, the portion of the first dielectric layer 170 extending beyond the second electrode portion 182 is made less than 3 nm, so as to form a Damascus structure, and the first transfer electrode 180 is slightly recessed in the surface of the first dielectric layer 170 on the side facing away from the epitaxial layer 110, but at the same time the surface maintains nanometer-level flatness, in preparation for subsequent connection with the drive substrate 200.
  • CMP chemical mechanical polishing
  • the first dielectric layer 170 may be formed first, and then the first via hole 171 may be formed through double exposure, development and etching processes, and then the first transfer electrode 180 may be further formed in the first via hole 171 through magnetron sputtering, electroplating or other processes.
  • S140 providing a driving substrate provided with a second dielectric layer and a second switching electrode.
  • the formation process of the second dielectric layer 220 and the second switching electrode 230 is similar to the formation process of the first dielectric layer 170 and the first switching electrode 180 , and will not be described in detail herein.
  • the second dielectric layer 220 extends beyond the top of the second transfer electrode 230 facing away from the power supply substrate 210 on one side of the power supply substrate 210, and through a chemical mechanical polishing (CMP) process, the portion of the second dielectric layer 220 extending beyond the second transfer electrode 230 is less than 3 nm, so that the second transfer electrode 230 is slightly recessed in the surface of the second dielectric layer 220 on the side facing away from the power supply substrate 210, but at the same time the surface maintains nanometer-level flatness.
  • CMP chemical mechanical polishing
  • the display substrate 100 is placed upside down on the driving substrate 200 in a form in which the second electrode portion 182 of the first transfer electrode 180 faces the third electrode portion 231 of the second transfer electrode 230, and a bonding device is used to accurately align the first transfer electrode 180 and the second transfer electrode 230 with each other and place them accordingly.
  • a bonding device can improve the alignment accuracy of the first transfer electrode 180 and the second transfer electrode 230 and reduce deviation.
  • the second transfer electrode 230 and the first transfer electrode 180, the transparent electrode layer and the reflective electrode pattern 140 are all arranged correspondingly, and the first dielectric layer 170 and the second dielectric layer 220 are attached to each other.
  • the second transfer electrode 230 and the first transfer electrode 180 are slightly recessed from the plane where the first dielectric layer 170 and the second dielectric layer 220 are attached to each other, the second transfer electrode 230 is The second electrode portion 182 is not attached to the third electrode portion 231 of the first connecting electrode 180 .
  • the first dielectric layer 170 and the second dielectric layer 220 and the first transfer electrode 180 and the second transfer electrode 230 can be bonded by heat pressing. Specifically, the two substrates are heated and pressurized so that the first dielectric layer 170, the second dielectric layer 220, the first transfer electrode 180 and the second transfer electrode 230 expand due to the heat.
  • the expansion degree of the first transfer electrode 180 and the second transfer electrode 230 is greater than that of the first dielectric layer 170 and the second dielectric layer 220. While the first dielectric layer 170 and the second dielectric layer 220 diffuse and fuse with each other, the second electrode portion 182 and the third electrode portion 231 can also be connected at the interface where the first dielectric layer 170 and the second dielectric layer 220 contact after expansion, and diffuse and fuse with each other, so that the first dielectric layer 170 and the second dielectric layer 220 and the first transfer electrode 180 and the second transfer electrode 230 can be aligned and bonded, thereby realizing high-strength connection between the display substrate 100 and the drive substrate 200.
  • the driving substrate 200 can supply power to the first semiconductor layer 111 of the epitaxial layer 110 through the first switching electrode 180 , the second switching electrode 230 and the reflective electrode pattern 140 , and the driving substrate 200 , the second switching electrode 230 and the reflective electrode pattern 140 can serve as the P electrode of the LED display device 10 .
  • the display substrate 100 is further processed to form a resonant cavity 101 .
  • Figures 8 to 9 the preparation process of the resonant cavity 101 of the LED display device 10 is shown in Figures 8 to 9, wherein Figure 8 shows a method for manufacturing the resonant cavity in the LED display device of the present application, and Figure 9 shows a schematic diagram of the preparation process corresponding to the process steps shown in Figure 8.
  • S210 etching the epitaxial layer to form a plurality of first recessed regions and a plurality of boss structures.
  • the substrate 116 can be removed by grinding, chemical etching or laser lift-off (LLO) to expose the epitaxial layer 110. Then, multiple locations on the side of the epitaxial layer 110 facing away from the reflective electrode pattern 140 are etched, wherein the etching depth is less than or equal to the layer thickness of the second semiconductor layer 113, so as to form multiple first recessed areas 114 on the surface of the epitaxial layer 110, and multiple convex structures 115 arranged at intervals are defined in the second semiconductor layer 113 by the first recessed areas 114.
  • the multiple convex structures 115 correspond to the multiple reflective electrode patterns 140 one by one, forming multiple display pixels of the LED display device 10.
  • the multiple reflective electrode patterns 140 can reflect the light emitted by the multiple convex structures 115, and the driving substrate 200 can supply current to the epitaxial layer 110 through the multiple reflective electrode patterns 140, so as to realize the individual control of the display pixels of the LED display device 10.
  • ion bombardment may be further used on the side of the epitaxial layer 110 facing away from the reflective electrode pattern 140 to form an insulating region, so that the first semiconductor layer 111 and the active layer 112 below the plurality of boss structures 115 are electrically isolated from each other in the epitaxial layer 110.
  • the thickness and resistivity of the first semiconductor layer 111 may be set in advance by controlling the lateral current diffusion, so that when the LED display device 10 works normally, the lateral current diffusion length of the first semiconductor layer 111 satisfies Ls ⁇ 1/2 ⁇ D1, where Ls is the lateral current diffusion length of the first semiconductor layer 111, and D1 is the shortest distance between the edges of the adjacent reflective electrode patterns 140.
  • the method of controlling the lateral current diffusion or setting the insulating region can be used to isolate each display pixel, thereby improving the reliability and yield of the LED display device 10 and reducing the probability of leakage.
  • the lateral current diffusion length Ls of the first semiconductor layer 111 is calculated by the following formula:
  • k is the Boltzmann constant
  • T is the thermodynamic temperature
  • e is the electron charge
  • t is the thickness of the first semiconductor layer 111
  • ⁇ is the resistivity of the first semiconductor layer 111
  • J_0 is the current density in the first current diffusion layer covered by the reflective electrode pattern 140 when the LED display device 10 is working normally.
  • S220 depositing a common electrode layer on a side of the epitaxial layer facing away from the reflective electrode pattern.
  • a first metal electrode layer 121 can be deposited on a side of the epitaxial layer 110 facing away from the reflective electrode pattern 140, so that the first metal electrode layer 121 covers the top walls of the multiple boss structures 115 and the first recessed area 114, so that the first metal electrode layer 121 completely covers the tops and side walls of the multiple boss structures 115, so that the first metal electrode layer 121 can reflect the leakage light passing through the side walls of the boss structures 115.
  • a second recessed area 122 is formed on the side away from the epitaxial layer 110, and then the second metal electrode layer 123 can be filled in the second recessed area 122 of the first metal electrode layer 121 by electroplating, so that the second metal electrode layer 123 fills the gaps between the multiple boss structures 115, and the top of the second metal electrode layer 123 facing away from the epitaxial layer 110 exceeds the top of the multiple boss structures 115 facing away from the reflective electrode pattern 140.
  • CMP chemical mechanical polishing
  • the chemical mechanical polishing (CMP) process can not only remove the redundant metal electrode layer, but also accurately control the thickness of the first semiconductor layer 111, so as to meet the thickness requirement of the resonant cavity.
  • the second metal electrode layer 123 and the first metal electrode layer 121 can jointly form a common electrode layer 120, and the second metal electrode layer 123 between the plurality of boss structures 115 is completely connected together, so that the common electrode layer 120 can be regarded as a common electrode of the LED display device 10, and can achieve good current diffusion effect.
  • the second metal electrode layer 123 may be exposed at a portion facing away from the side wall of the boss structure 115, and the exposed edge portion of the second metal electrode layer 123 may be connected to the substrate of the drive substrate 200 through a common trace 300 by wire bonding, so that the common electrode layer 120 of the display substrate 100 is electrically connected to the drive substrate 200.
  • the common electrode layer 120 of the display substrate 100 may also be electrically connected to the drive substrate 200 through a TSV hole connection.
  • S230 depositing a reflection layer on top walls of the plurality of boss structures and the top of the common electrode layer to form a plurality of resonant cavities.
  • a reflective layer 130 is deposited on the top of the boss structure 115 facing away from the reflective electrode pattern 140 and the top of the second metal electrode, so that the reflective layer 130 covers the top wall of the boss structure 115 and the common electrode layer 120.
  • multiple boss structures 115 are wrapped by the first metal electrode, the reflective layer 130 and the reflective electrode pattern 140 to form multiple resonant cavities 101.
  • the reflectivity of the reflective layer 130 is lower than the reflectivity of the reflective electrode pattern 140, so that the light enters the resonant cavity 101 and is concentrated and emitted from one side of the reflective layer 130.
  • the side of the reflective layer 130 facing away from the boss structure 115 can be A microlens layer is added to make the light output angle more collimated.
  • the wavelength conversion layer 150 and the color filter layer 160 of the LED display device 10 are further prepared to form color display pixels.
  • the following takes the preparation of display pixels of three colors, red, green and blue, and the light emitted by the plurality of boss structures 115 is blue light as an example to exemplarily describe the preparation process of the wavelength conversion layer 150 and the color filter layer 160 .
  • the preparation process of the wavelength conversion layer 150 and the color filter layer 160 of the LED display device 10 can have multiple implementation methods, one of which is shown in Figures 10 to 11, where Figure 10 is a flow chart of an implementation method of the wavelength conversion layer 150 and the color filter layer 160 of the present application, and Figure 11 is a preparation process schematic diagram corresponding to the process steps shown in Figure 10.
  • S311 Covering a wavelength conversion layer on the surface of the reflective layer facing away from the boss structure.
  • the wavelength conversion layer 150 can be formed by stacking multiple sub-wavelength conversion layers of different colors. For example, a green sub-wavelength conversion layer can be firstly covered on the surface of the reflective layer 130 facing away from the boss structure 115 by deposition. After the first sub-wavelength conversion layer is formed, the thickness can be controlled. The thickness and surface flatness of the sub-wavelength conversion layer can be accurately controlled by thermal evaporation, a uniform coating process, or a chemical mechanical polishing (CMP) process to achieve uniformity in the wavelength and intensity of the converted light of the entire wavelength sub-wavelength conversion layer. At this time, the blue first light emitted through the multiple boss structures 115 forms a mixed light of blue and green after passing through the green sub-wavelength conversion layer.
  • CMP chemical mechanical polishing
  • a red sub-wavelength conversion layer can be coated on the surface of the green wavelength conversion layer 150 in a similar deposition manner, and then the thickness and surface flatness of the sub-wavelength conversion layer can be precisely controlled by thermal evaporation, coating or mechanical polishing (CMP) and other processes.
  • CMP mechanical polishing
  • the wavelength conversion layer 150 can also be a film made of green or red quantum dot material. During the preparation of the LED display device 10, the wavelength conversion layer 150 can be fixed to the surface of the reflective layer 130 facing away from the boss structure 115 by using optical glue to reduce the difficulty of preparing and processing the LED display device 10.
  • the three-color mixing effect can be adjusted by controlling the material and thickness of the wavelength conversion layer 150.
  • the wavelength conversion layer 150 can also be a single-layer wavelength conversion layer 150 made by mixing green and red quantum dot materials, thereby achieving green and red color mixing.
  • sub-wavelength conversion layers of different colors can be added according to the requirements of the light emitted by the LED display device 10, or the color of the wavelength conversion layer 150 can be changed to adjust the color mixing effect of the second light.
  • S312 performing a development process on a side of the wavelength conversion layer away from the epitaxial layer to form a plurality of color filter patterns corresponding to the plurality of boss structures, so as to form a color filter layer.
  • the step S312 process for preparing the color filter layer 160 includes the following steps S301-S305, as specifically shown in FIG. 12 to FIG. 13 , wherein FIG. 12 is a flow chart of an embodiment of a method for manufacturing the color filter layer 160 of the present application, and FIG. 13 is a flow chart of the preparation process corresponding to the flow chart steps shown in FIG. 12 .
  • S301 Disposing a black matrix on the side of the wavelength conversion layer away from the epitaxial layer.
  • a black matrix 162 such as chromium or black resin with low reflectivity may be added to the side of the wavelength conversion layer 150 away from the epitaxial layer 110 , and the black matrix 162 exposes corresponding positions of a plurality of boss structures 115 on the side of the wavelength conversion layer 150 away from the epitaxial layer 110 to form a black matrix.
  • a color photoresist layer 163 is coated on the side of the wavelength conversion layer 150 away from the epitaxial layer 110, and the color photoresist layer 163 fills the gaps of the black matrix and covers the black matrix.
  • the color of the color photoresist layer 163 is one of blue, green and red.
  • a designated position of the color photoresist layer 163 may be exposed using a photomask, so that the color photoresist layer 163 at the designated position may be fixed at the designated position.
  • S304 removing other parts of the color photoresist layer by developing and further baking and curing to form a plurality of color filter patterns.
  • the unnecessary part of the color photoresist layer 163 can be removed by a developer to leave the color photoresist layer 163 at the designated position, and the color photoresist layer 163 at the designated position is cured by baking to form a plurality of color filter patterns 161.
  • the designated position is the position corresponding to the part of the boss structure 115, so that the LED display device 10 can emit the color filter pattern 161 at the designated position to display light of a specific color.
  • S305 repeating steps S301 to S304 to obtain a plurality of color filter patterns of other colors to form a plurality of color filter layers.
  • the present application manufactures color display pixels by completely covering the wavelength conversion layer 150 and preparing the color filter pattern 161 on the wavelength conversion layer 150 by first covering and then removing, without the need for spot spraying of the color filter pattern 161.
  • This makes the color filter layer 160 and the wavelength conversion layer 150 more uniform and flat, and it is easier to control the thickness of the wavelength conversion layer 150 and the color filter layer 160.
  • a microlens 164 can be added to the color filter pattern 161 to form a microlens array in the color filter layer 160 to further adjust the light type of the emitted light.
  • FIG. 15 is a schematic diagram of the preparation process flow of another implementation method of the wavelength conversion layer 150 and the color filter layer 160 of the present application
  • Figure 16 is a schematic diagram of the preparation process corresponding to the process steps shown in Figure 15.
  • S321 providing a transparent substrate, and performing a developing process on one side of the transparent substrate to form a plurality of color filter patterns to form a color filter layer.
  • a transparent substrate 190 is provided, wherein the transparent substrate 190 may be a colorless transparent substrate 190 such as a non-conductive glass substrate or an acrylic substrate, so that the transparent substrate 190 can transmit light without affecting the color of the light.
  • the transparent substrate 190 may be a colorless transparent substrate 190 such as a non-conductive glass substrate or an acrylic substrate, so that the transparent substrate 190 can transmit light without affecting the color of the light.
  • the specific positions and areas of the multiple color filter patterns 161 on the transparent substrate 190 are determined in advance to prepare the multiple color filter patterns 161 corresponding to the multiple boss structures 115.
  • the specific steps of preparing the color filter layer 160 on one side of the transparent substrate 190 can refer to steps S301-S305, which are not repeated here.
  • the side of the multiple color filter patterns 161 away from the transparent substrate 190 can be set to be flush with the side of the black matrix 162 away from the transparent substrate 190 to form a flat surface for subsequent operations.
  • the preparation process of disposing the wavelength conversion layer 150 on the side of the color filter layer 160 away from the transparent substrate 190 is similar to the process of preparing the wavelength conversion layer 150 on the surface of the reflective layer 130 described in step S311, so reference may be made to step S311 and will not be repeated here.
  • the transparent substrate is aligned and fixed on the side of the reflective layer facing away from the boss structure in a manner that the wavelength conversion layer faces the reflective layer.
  • the wavelength conversion layer 150 on the transparent substrate 190 can be fixed to the side of the reflective layer 130 facing away from the boss structure 115 by bonding with an optical adhesive layer 131.
  • the optical adhesive layer 131 can be a colorless and transparent optical adhesive with a light transmittance of more than 90%, good bonding strength and small curing shrinkage, such as organic silicone, polyurethane, epoxy resin and other adhesives. In this way, the stability of the LED display device 10 can be improved while reducing the influence of the optical adhesive layer 131 on the first light emitted by the reflective layer 130.
  • an optical adhesive layer 131 may be applied to the side of the reflective layer 130 facing away from the boss structure 115, and then the transparent substrate 190 may be inverted, and the wavelength conversion layer 150 may be attached to the optical adhesive layer 131 in a manner that the wavelength conversion layer 150 faces the optical adhesive layer 131.
  • the optical adhesive layer 131 is then further cured to fix the positions of the wavelength conversion layer 150 and the color filter patterns 161, so as to complete the alignment and fixing of the transparent substrate 190 and the color filter layer 160.
  • the LED display device 10 obtained by this embodiment is shown in FIG. 17 , and the display substrate 100 further includes an optical adhesive layer 131 disposed on the side of the reflective layer 130 away from the epitaxial layer 110.
  • the side of the optical adhesive layer 131 facing away from the reflective layer 130 is fixedly attached to the wavelength conversion layer 150.
  • a plurality of color filter patterns 161 are disposed on the side of the wavelength conversion layer 150 facing away from the optical adhesive layer 131 to form the color filter layer 160.
  • the plurality of color filter patterns 161 are separated by a black matrix 162.
  • a transparent substrate 190 is fixedly disposed on the side of the color filter layer 160 facing away from the wavelength conversion layer 150.
  • the first light emitted from the plurality of boss structures 115 can pass through the optical adhesive layer 131 and then through the wavelength conversion layer 150, thereby forming a second light of a mixture of blue, green and red colors, and then pass through the plurality of color filter patterns 161, thereby filtering the second light to obtain a third light of different colors.
  • the third light can further pass through the transparent substrate 190 and be emitted to the outside.
  • This embodiment can not only utilize the transparent substrate 190 to isolate and protect the color filter pattern 161, but also make the preparation process of the wavelength conversion layer 150 and the color filter layer 160 easier to operate, and can also prepare the wavelength conversion layer 150 and the color filter layer 160 while preparing other components of the LED display device 10, thereby shortening the preparation time of the LED display device 10. Process duration.
  • the present application provides a plurality of boss structures 115 and a first recessed area 114 on the epitaxial layer 110, and a reflective layer 130 is provided on one side of the boss structure 115 and is opposite to a plurality of reflective electrode patterns 140, wherein the reflectivity of the reflective layer 130 is less than the reflectivity of the reflective electrode pattern 140, so as to form a resonant cavity 101 that emits light from one side of the reflective layer 130, thereby achieving collimated light emission from the LED display device 10 and improving the collimation of the emitted light.
  • the display substrate 100 and the drive substrate 200 are aligned and bonded to each other by hot pressing to achieve a high-strength connection.
  • the color display pixels of the LED display device 10 are prepared by first covering the wavelength conversion layer 150 and then providing the color filter layer 160, so that the process of preparing the color display pixels is simplified and the production yield can be improved.

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Abstract

本申请公开了LED显示设备，该LED显示设备包括显示基板，该显示基板包括外延层、公共电极层、反射层和多个反射电极图案，外延层包括依次层叠设置的第一半导体层、有源层以及第二半导体层。第二半导体层设置有第一凹陷区，通过第一凹陷区在第二半导体层背离有源层的一侧限定出多个凸台结构。公共电极层填充于第一凹陷区内与多个凸台结构的侧壁接触。反射层覆盖凸台结构的顶壁和公共电极层。反射电极图案间隔设置于第一半导体层背离有源层的一侧，并分别对应于凸台结构。反射层的反射率小于反射电极图案的反射率，以形成从反射层一侧出光的谐振腔。通过上述方式，本申请可以提高实现LED显示设备出射光的准直性，实现准直出光。

Description

LED显示设备 【技术领域】
本申请涉及显示技术，特别是涉及LED显示设备。
【背景技术】
Micro-LED技术是将传统的LED微缩化和矩阵化的技术，先将传统的大尺寸LED芯片微缩化至微米量级的Micro-LED芯片，再将其矩阵化为高密度集成的LED阵列，使得应用了Micro-LED技术的显示屏中每个显示像素均可以被独立地定位、点亮，从而实现对每个Micro-LED芯片的精确控制，进而实现显示功能。
但是由于将Micro-LED芯片微缩化至微米量级后产生的尺寸效应导致LED显示设备的出光效率受到影响，并且由于Micro-LED尺寸缩小后，侧壁的发光加强，使得LED显示设备的出射光角度不够准直。
【发明内容】
本申请的实施例提供了LED显示设备，能够实现LED显示设备准直出光，提高出射光的准直性。
为解决上述技术问题，本申请采用的一个技术方案是提供一种LED显示设备，该LED显示设备包括显示基板，该显示基板包括：
外延层，外延层包括依次层叠设置的第一半导体层、有源层以及第二半导体层，其中第二半导体层在背离有源层的一侧设置有第一凹陷区，通过第一凹陷区在第二半导体层背离有源层的一侧限定出间隔排布的多个凸台结构，其中第一凹陷区的深度小于或等于第二半导体层的层厚度；
公共电极层，公共电极层填充于第一凹陷区内，并与多个凸台结构的侧壁接触，公共电极层进一步外露凸台结构的顶壁；
反射层，覆盖凸台结构的顶壁和公共电极层；
多个反射电极图案，多个反射电极图案间隔设置于第一半导体层背离有源层的一侧，并分别对应于多个凸台结构，其中反射层的反射率小于反射电极图案的反射率，以形成从所述反射层一侧出光的谐振腔。
本申请的有益效果是：区别于现有技术的情况，本申请通过在外延层设置多个凸台结构以及第一凹陷区，并在第一凹陷区内填充有公共电极层，使得公共电极层将多个凸台结构间隔开，而且在凸台结构的一侧设置有反射层并在背对多个反射电极图案，其中反射层的反射率小于反射电极图案的反射率，以形成从反射层一侧出光的谐振腔，实现LED显示设备准直出光，提高出射光的准直性。
【附图说明】
图1是本申请LED显示设备一实施方式的结构示意图；
图2是本申请LED显示设备一实施方式的部件结构示意图；
图3是无谐振腔的LED显示设备一实施方式的出光效果示意图；
图4是有谐振腔的LED显示设备一实施方式的出光效果示意图；
图5是本申请LED显示设备的制造方法一实施方式的流程示意图；
图6是图5所示LED显示设备的制造方法对应的一制备过程示意图；
图7是图5所示LED显示设备的制造方法对应的另一制备过程示意图；
图8是本申请LED显示设备中谐振腔的制造方法一实施方式的流程示意图；
图9是图8所示LED显示设备中谐振腔的制造方法对应的制备过程示意图；
图10是本申请波长转换层与彩色滤光层的制造方法一实施方式的流程示意图；
图11是图10所示的波长转换层与彩色滤光层的制造方法对应的制备过程示意图；
图12是本申请彩色滤光层的制造方法一实施方式的流程示意图；
图13是图12所示的彩色滤光层的制造方法对应的制备过程示意图；
图14是本申请LED显示设备另一实施例的部分结构示意图
图15是本申请彩色滤光层的制造方法另一实施方式的流程示意图；
图16是图15所示的彩色滤光层的制造方法另一实施方式对应的制备过程示意图；
图17是本申请LED显示设备另一实施方式的结构示意图。
【具体实施方式】
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本申请的一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
本申请发明人经过长期研究发现，当前的Micro-LED芯片微缩化至微米量级后由于产生的尺寸效应导致Micro-LED芯片的出光效率受到影响，并且由于Micro-LED尺寸缩小后，侧壁的发光加强，使得Micro-LED芯片的出射光角度不够准直。为此，本申请提出以下实施例。
以下本申请LED显示设备实施例描述LED显示设备的示例性结构。
如图1所示，LED显示设备10包括显示基板100、驱动基板200以及公共走线300。显示基板100用于形成LED显示设备10的像素结构，驱动基板200用于形成LED显示设备10的驱动结构，公共走线300用于电连接显示基板100和驱动基板200。
其中，显示基板100包括外延层110、公共电极层120、反射层130以及多个反射电极图案140。
其中，外延层110用于通过电子和空穴的复合进行发光，并定义出多个显示像素(下文描述)。公共电极层120可作为LED显示设备10的N电极向外延层110供电，并作为向上述多个显示像素统一供电的公共电极，并且公共走线300电连接公共电极层120和驱动基板 200。反射层130设于外延层110与公共电极层120的顶层，用于部分透过外延层110射出的光线，且部分反射外延层110射出的光线。多个反射电极图案140间隔设置于外延层110背对反射层130的一侧，用于反射外延层110的射出光线，同时可作为LED显示设备10的P电极向外延层110供电，并作为向上述多个显示像素分别供电的像素电极。
公共电极层120、反射层130以及多个反射电极图案140皆可以反射外延层110射出的光线，且反射层130的反射率小于反射电极图案140的反射率，以形成从反射层130一侧出光的谐振腔101。
具体地，如图1所示，外延层110包括依次层叠设置的第一半导体层111、有源层112以及第二半导体层113。其中，第一半导体层111与第二半导体层113分别为P型和N型半导体层，第一半导体层111与第二半导体层113分别为AlN、AlGaN、GaN、InGaN、AlInGaN、GaAs、GaP、GaInN、GaAsP、AlGaAs、AlGaInP等半导体材料中掺杂形成。有源层112为工作介质层，有源层112例如可以是多量子阱结构。
进一步地，第二半导体层113在背离有源层112的一侧设置有第一凹陷区114，通过第一凹陷区114在第二半导体层113背离有源层112的一侧限定出间隔排布的多个凸台结构115。间隔排布的多个凸台结构115及其下方的第一半导体层111和有源层112可作为LED显示设备10的显示像素。当第一半导体层111和第二半导体层113接入工作电压时，来自P型半导体层的空穴和来自N型半导体层的电子在有源层112复合发光。
其中第一凹陷区114的深度小于或等于第二半导体层113的层厚度，即第一凹陷区114的深度并未到达有源层112，如此避免有源层112受到破坏而导致非发光复合，从而提高LED显示设备10的出光效率。
可选地，为了避免上述显示像素之间的电串扰，在一具体实施方式中，在第一凹陷区114的底部所对应的第一半导体层111和有源层112内设置有通过离子轰击形成的绝缘区(图未示)，以使得多个凸台结构115下方的第一半导体层111和有源层112在外延层110内彼此电性隔离，各显示像素由对应的反射电极图案140输入的电流不同经第一半导体层111和有源层112扩散到其他显示像素。
在另一具体实施方式中，可以先对第一半导体层111的厚度和电阻率进行设置处理，使得在LED显示设备10正常工作时，第一半导体层111的横向电流扩散长度满足Ls≤1/2×D1，其中Ls为第一半导体层111的横向电流扩散长度，D1为相邻设置的反射电极图案140的边缘之间的最短间距。
通过对第一半导体层111的厚度和电阻率的设置，使得第一半导体层111的横向电流扩散时，不会影响相邻设置的反射电极图案140对应的第一半导体层111的横向电流扩散。也就是说，每个反射电极图案140对应的显示像素的工作电流不会扩散至相邻显示像素。每个反射电极图案140对应的有源层112可被独立控制发光，从而在大尺寸LED芯片上通过调节横向电流扩散长度实现各显示像素的自隔离，从而提高LED显示设备10的可靠性和良率，降低漏电几率。而且，自隔离的实现能够简化芯片工艺流程，降低生产成本。
如图1所示，公共电极层120填充于第一凹陷区114内，并与多个凸台结构115的侧壁接触，且公共电极层120外露凸台结构115的顶壁。
在一具体实施方式中，如图2所示，公共电极层120环绕多个凸台结构115，并对多个凸台结构115的侧壁进行全包围接触，使得外延层110内的光不会透过凸台结构115的侧壁传输到其他凸台结构115，而发生光串扰。同时公共电极层120在多个凸台结构115之间的间隔区域内保持互连，以作为多个显示像素的公共电极，在LED显示设备10接通工作电压时可以实现良好的电流扩散作用，能够给外延层110提供电流以使得外延层110得以复合发光。
进一步地，公共电极层120包括随形附着于多个凸台结构115的侧壁和第一凹陷区114底部的第一金属电极层121以及填充于第一金属电极层121所形成的第二凹陷区122内的第二金属电极层123。其中，第一金属电极层121的反射率大于第二金属电极层123的反射率。
第一金属电极层121用于向凸台结构115传导电流以及反射凸台结构115内反射至侧壁的光线，以提高LED显示设备10的出光效率，使得多个凸台结构115之间的光线不会发生串扰。第二金属电极层123用于通过向第一金属电极层121传导电流而向凸台结构115中的第二半导体供电，从而可以与第二半导体层113形成公共电极。
而设置第一金属电极层121的反射率大于第二金属电极层123的反射率，可以使得凸台结构115产生的光线在到达凸台结构115的侧壁与第一金属电极层121时被最大程度的反射回凸台结构115内，从而减少光线在第一金属电极层121内传播的损失，提高LED显示设备10的出光效率，同时可以降低成本。
在一实施方式中，第一金属电极层121为铝电极层，使用高反射金属铝作为第一金属电极层121材料可以使得公共电极层120具有更好的光反射效果。第二金属电极层123为铜金属层，铜金属具有良好的导电作用，可以提高电流扩散的效率。当然，在其他的实施方式中，第一金属电极层121也可以为钛、铬等和铝的多层金属层掺杂形成的金属层，第二金属电极层123可以为其他导电材料，在此不做第一金属电极层121和第二金属电极层123的材料限定。
可选地，公共电极层120背离有源层112一侧设置成与凸台结构115的顶壁平齐，并形成一连续平面。反射层130覆盖凸台结构115的顶壁和公共电极层120，以使得反射层130可以反射从凸台结构115的顶壁射出的光线，且反射层130完全覆盖凸台结构115的顶壁和公共电极层120形成的连续平面使得反射层130的覆盖工艺更加简单。反射层130可以为金属铝层，也可以是DBR反射镜等其他的材料制得的具有反射光线能力的反射层130。
多个反射电极图案140可间隔设置于第一半导体层111背离有源层112的一侧，并分别对应于多个凸台结构115，其中反射层130的反射率小于反射电极图案140的反射率，以使得多个凸台结构115内的光线到达反射电极图案140以及侧壁的第一金属电极层121后能够被反射回来，以形成从反射层130一侧出光的谐振腔101，从而提高LED显示设备10出光的准直性。
如图3至图4所示，图3示出了无谐振腔101的LED显示设备10的出光效果，图4示出了设置谐振腔101后的LED显示设备10的出光效果。由两图对比可知，无谐振腔101的LED显示设备10的出光效果为出光角度较散的朗伯型，而设置谐振腔101后的LED显示设备10将朗伯型出光变成垂直的轴向出光，将光线的出光角度集中，提高出光的准直性，实现准直出光。
如图1所示，显示基板100可进一步包括设置于反射层130背离外延层110一侧的波长转换层150以及设置于波长转换层150背离外延层110一侧的彩色滤光层160。其中波长转换层150用于将凸台结构115的顶壁输出的第一光线转换成第二光线，彩色滤光层160包括分别与多个凸台结构115对应的设置的多个彩色滤光图案161，彩色滤光图案161用于将第二光线过滤成第三光线，至少部分彩色滤光图案161所形成的第三光线的颜色彼此不同。
可选地，波长转换层150以整面覆盖的方式设置于反射层130背离外延层110一侧，彩色滤光图案161以显影工艺形成于波长转换层150背离外延层110一侧，从而形成彩色滤光层160。
其中，显影工艺为先使用半导体匀胶覆盖一层彩色光阻层，而后对指定位置的彩色光阻层进行曝光，进一步通过显影液去除其他部分的彩色抗蚀层，以实现指定位置的彩色滤光图案161的图案化，最后通过烘烤固化形成彩色滤光层160。
其中，波长转换层150可以由具有一定颜色的量子点材料制作而成，如此可以使得凸台结构115的顶壁输出的第一光线通过波长转换层150时叠加波长转换层150中对应的颜色，进而使得波长转换层150输出的第二光线混有波长转换层150的颜色从而形成混色。可选地，波长转换层150可以为多层不同颜色的子波长转换层层叠而成，从而输出多种颜色混色的第二光线，波长转换层150也可以为多种颜色的量子点材料混合制作而实现多种颜色混色的单层波长转换层150。
多个彩色滤光图案161可以为具有一定颜色的滤光片，设置于对应多个凸台结构115的位置，且多个凸台结构115所射出的光线可以通过多个彩色滤光图案161射出。
多个彩色滤光图案161的颜色可以为第二光线的混和颜色中的一种，多种颜色混色的第二光线通过多个彩色滤光图案161时，彩色滤光图案161可透过第二光线中的对应彩色滤光图案161本身的颜色的光线，而过滤其他的颜色的光线，从而将多种颜色混色的第二光线转化为只有彩色滤光图案161本身颜色的第三光线。且至少部分彩色滤光图案161不同于其他的彩色滤光图案161，使得通过多个彩色滤光图案161第三光线具有不同的颜色，以使得LED显示设备10的各个显示像素可显示出不同的色彩。
例如，若LED显示设备10要实现红绿蓝三色的混光，而凸台结构115发射的第一光线为蓝光时，波长转换层150可为绿色的子波长转换层与红色的子波长转换层层叠而成，或者波长转换层150可以为掺入了绿色和红色量子点的单层波长转换层150，以使得波长转换层150将第一光线的蓝光转化为蓝色、绿色和红色混色的第二光线。彩色滤光层160包括有多个蓝色、绿色、红色的彩色滤光图案161，第二光线分别经过三种颜色的彩色滤光图案161 时，彩色滤光图案161将第二光线分别过滤成具有对应该彩色滤光图案161颜色的第三光线，以使得LED显示设备10可显示蓝色、绿色、红色三种颜色的光线。
如图1所示，显示基板100进一步可以包括第一介质层170以及第一转接电极180，第一介质层170覆盖第一半导体层111背离有源层112的一侧以及反射电极图案140，第一介质层170设置有允许反射电极图案140外露的第一过孔171，第一转接电极180设置于第一过孔171内，并与反射电极图案140导电连接。
其中，第一介质层170的制作材料可以为二氧化硅或者其他绝缘材料制作而成的氧化物层，以用于固定第一转接电极180的位置以及作为阻止杂质扩散的掩蔽膜和保护层。第一转接电极180可以为金属铜或者其他具有导电性材料制作而成的电极。
如图1所示，驱动基板200可包括供电基板210、第二介质层220以及第二转接电极230，第二介质层220设置有第二过孔221，第二转接电极230设置于第二过孔221内。其中，第二介质层220以及第二转接电极230接设置于供电基板210上，并在供电基板210上呈现大马士革结构，且第一转接电极180可电连接供电基板210，以使得供电基板210可以将电流传递至第二转接电极230。
其中，第二介质层220也可为二氧化硅或者其他绝缘材料制作而成的氧化物层，以用于固定第二转接电极230的位置以及作为阻止杂质扩散的掩蔽膜和保护层。而第二转接电极230可为金属铜或者其他具有导电性材料制作而成的电极。
可选地，第一介质层170与第二介质层220之间以及第一转接电极180和第二转接电极230之间可以通过热压方式对位键合，以使得第一转接电极180与第二转接电极230以及第一介质层170与第二介质层220相互连接融为一体，实现显示基板100与驱动基板200的高强度连接，以使得供电基板210可以顺利将电流通过第一转接电极180与第二转接电极230传递至外延层110中的第一半导体层111。
可选地，第一转接电极180可以包括靠近反射电极图案140的第一电极部181以及远离反射电极图案140的第二电极部182，第二转接电极230包括靠近第一转接电极180的第三电极部231以及远离第一转接电极180的第四电极部232。在第一半导体层111、有源层112以及第二半导体层113的层叠方向的垂直方向上，第一电极部181的尺寸小于第二电极部182的尺寸，第四电极部232的尺寸小于第三电极部231的尺寸。如此设置可以增加第一转接电极180与第二转接电极230互相连接一面的接触面积，以提高第一转接电极180与第二转接电极230之间的融合程度，实现更高强度的连接。
在一实施方式中，供电基板210上以阵列地方式排布有多个开关器件(图未示)，且每个第二转接电极230电连接至对应的开关器件，即开关器件与反射电极图案140一一对应，以由所连接的开关器件提供驱动信号至第二转接电极230，驱动信号可以依次通过第二转接电极230、第一转接电极180与反射电极图案140到达外延层110的第一半导体层111，进而实现显示像素的单独控制。
如图1所示，LED显示设备10进一步可以包括在显示基板100和驱动基板200的外侧 并将公共电极层120电连接至驱动基板200的公共走线300。在一具体实施方式中，公共电极层120裸露于显示基板100的侧边，公共走线300一端固定连接于公共电极层120中的第二金属电极层123，另一端连接于驱动基板200的基板上，其中公共走线300可以通过打线连接的方式固定连接公共电极层120和驱动基板200，使得驱动基板200提供的电流可通过公共走线300传递至公共电极层120中。
在其他实施方式中，也可以通过打孔的方式，在显示基板100非显示像素区域与驱动基板200的对应区域进行打孔，而后公共走线300通过穿孔连接公共电极层120和驱动基板200。
以上述LED显示设备10的结构为例，以下示例性地描述LED显示设备10的制备过程。
在一实施方式中，可以率先将显示基板100的部分组件固定于驱动基板200上，再进一步对显示基板100的部分组件进行处理以形成谐振腔101。
具体地，显示基板100的部分组件与驱动基板200的制备连接流程步骤如图5至图7所示，其中图5示出了显示基板100的部分组件的制备流程以及与驱动基板200键合的流程，图6为与图5所示的流程步骤S110-S130所对应的一制备过程示意图，图7为与图5所示的流程步骤S140-S150所对应的另一制备过程示意图。在其他实施方式中，可以对下述制备流程进行调整。
S110：提供外延层。
该外延层110可以通过生长方式形成衬底116上，或者以转移方式固定于衬底116上，例如将外延层110以第二半导体层113面向衬底116的形式固定于衬底116上，衬底116在接触外延层110可提前涂抹粘合胶，用于粘合固定外延层110。
S120：在第一半导体层背离有源层的一侧形成间隔设置反射电极图案。
在一具体实现过程中，在外延层110的第一半导体层111表面可以采用退火工艺覆盖一层透明电极层1171，例如透明电极ITO，退火工艺结束后透明电极层1171可与外延层110形成欧姆接触。而后在退火后在透明电极层1171表面覆盖一层金属电极层1401，并且对透明电极层1171和金属电极层1401进行刻蚀处理，得到多个透明电极117以及多个反射电极图案140。多个反射电极图案140的间隔距离可以按照对LED显示设备10的显示像素需求距离计算得出。
在一些实施方式中，可以在设置形成间隔设置的多个反射电极图案140后，对多个反射电极图案140之间的间隔区域进行离子轰击，使得多个反射电极图案140的间隔对应的外延层110可以形成绝缘区，从而实现多个反射电极图案140对应的外延层110可以彼此电性隔离，以实现显示像素之间的独立。
或者，采用控制横向电流扩散的方式，预先对第一半导体层111的厚度和电阻率进行设置，使得在LED显示设备10正常工作时，第一半导体层111的横向电流扩散长度满足Ls≤1/2×D1，其中Ls为第一半导体层111的横向电流扩散长度，D1为相邻设置的反射电极图案140的边缘之间的最短间距。
或者，可以先对多个反射电极图案140之间的间隔区域对应的第一半导体层111进行刻 蚀，其刻蚀的深度不超过第一半导体层111的厚度。而后对多个反射电极图案140之间的间隔区域进行离子轰击，或者通过控制第一半导体层111的扩散电流，来进一步形成绝缘区。
设置绝缘区或者在多个反射电极图案140的一侧采用控制横向电流扩散的方式，可以在不损伤有源层112的情况下，实现隔离各显示像素，从而提高LED显示设备10的可靠性和良率，降低漏电几率。
S130：形成第一介质层和多个第一转接电极。
在一具体实施方式中，以第一电极部181面对反射电极图案140的方式，将多个第一转接电极180对应放置于多个反射电极图案140背离外延层110的一侧，使得外延层110背对衬底116的一侧上形成间隔排布多个反射电极图案140以及多个第一转接电极180。
可选地，在多个反射电极图案140以及多个第一转接电极180之间填充第一介质层170，其中，第一介质层170在背对外延层110的一面超出第一转接电极180的第二电极部182背对外延层110的顶端，并通过化学机械抛光(CMP)工艺，使得第一介质层170超出第二电极部182的部分小于3nm，以使得形成大马士革结构，且第一转接电极180在背对外延层110的一面微微凹陷于第一介质层170表面，但是同时表面保持纳米级的平整度，为后续与驱动基板200的连接做准备。
在另一具体实施方式中，可以先形成第一介质层170，在通过两次曝光显影和刻蚀工艺形成第一过孔171，再进一步在第一过孔171内通过磁控溅射、电镀或其他工艺形成第一转接电极180。
S140：提供设置有第二介质层和第二转接电极的驱动基板。
第二介质层220和第二转接电极230的形成工艺与第一介质层170和第一转接电极180的形成工艺类似，在此不再赘述。
第二介质层220在供电基板210的一面超出第二转接电极230背对供电基板210的顶端，并通过化学机械抛光(CMP)工艺使得，第二介质层220超出第二转接电极230的部分小于3nm，以使得第二转接电极230在背对供电基板210的一面微微凹陷于第二介质层220表面，但是同时表面保持纳米级的平整度。
S150：将显示基板倒置于驱动基板上，通过热压方式实现显示基板与驱动基板的对位键合连接。
将显示基板100和驱动基板200表面经过等离子体活化或化学处理后，以第一转接电极180的第二电极部182面对第二转接电极230的第三电极部231形式将显示基板100倒置放置于驱动基板200上，并使用结合设备使得第一转接电极180与第二转接电极230准确对准对方对应放置。使用结合设备可以提高第一转接电极180与第二转接电极230对应的对位精准度，减少偏差。
此时第二转接电极230与第一转接电极180、透明电极层以及反射电极图案140皆呈对应设置，且第一介质层170与第二介质层220贴合，但由于第二转接电极230与第一转接电极180微微凹陷第一介质层170与第二介质层220贴合的平面，因此第二转接电极230的第 二电极部182与第一转接电极180的第三电极部231并未贴合。
对准位置后，可以通过热压方式将第一介质层170与第二介质层220之间以及第一转接电极180和第二转接电极230之间实现对位键合。具体地，对两个基板进行加热加压处理，使得第一介质层170、第二介质层220、第一转接电极180以及第二转接电极230受热膨胀。
由于金属的热膨胀系数大于介质材料，因此第一转接电极180与第二转接电极230的膨胀程度大于第一介质层170与第二介质层220，在第一介质层170与第二介质层220互相扩散融为一体的同时，第二电极部182与第三电极部231膨胀后也可以在第一介质层170与第二介质层220所接触的界面处连接，且互相扩散融为一体，以使得第一介质层170与第二介质层220之间以及第一转接电极180和第二转接电极230之间实现对位结合键合，从而实现显示基板100与驱动基板200的高强度连接。
此时驱动基板200可通过第一转接电极180、第二转接电极230和反射电极图案140向外延层110的第一半导体层111供电，驱动基板200与第二转接电极230和反射电极图案140可作为LED显示设备10的P电极。
在实现显示基板100与驱动基板200的高强度连接后，进一步对显示基板100进一步进行处理以形成谐振腔101。
其中，LED显示设备10的谐振腔101的制备过程如图8至图9所示，其中图8示出了本申请LED显示设备中谐振腔的制造方法，图9示出了图8所示的流程步骤所对应的制备过程示意图。
S210：对外延层进行刻蚀以形成多个第一凹陷区和多个凸台结构。
可以通过研磨、化学腐蚀或者激光剥离(laser lift-off，LLO)等工艺去除衬底116，使得外延层110外露。继而对外延层110背对反射电极图案140一面的多处进行刻蚀处理，其中刻蚀的深度为小于或等于所述第二半导体层113的层厚度，以在外延层110表面形成多个第一凹陷区114，通过第一凹陷区114在第二半导体层113限定出间隔排布的多个凸台结构115，多个凸台结构115与多个反射电极图案140一一对应，形成LED显示设备10的多个显示像素。且多个反射电极图案140可以反射多个凸台结构115射出的光线，而驱动基板200可通过多个反射电极图案140向外延层110供应电流，以实现LED显示设备10的显示像素的单独控制。
在一实施方式中，在形成多个凸台结构115后，可以进一步在外延层110背对反射电极图案140的一面采用离子轰击进而形成绝缘区，使得多个凸台结构115下方的第一半导体层111和有源层112在外延层110内彼此电性隔离。或者采用控制横向电流扩散的方式，预先对第一半导体层111的厚度和电阻率进行设置处理，使得在LED显示设备10正常工作时，第一半导体层111的横向电流扩散长度满足Ls≤1/2×D1，其中Ls为第一半导体层111的横向电流扩散长度，D1为相邻设置的反射电极图案140的边缘之间的最短间距。采用控制横向电流扩散的方式或者设置绝缘区的方式可以实现隔离各显示像素，从而LED显示设备10的可靠性和良率，降低漏电几率。
第一半导体层111的横向电流扩散长度Ls通过以下公式计算：
L_s＝√(kT/e×t/(ρJ_0))(1)
其中，k为玻尔兹曼常数，T为热力学温度，e为电子电量，t为所述第一半导体层111的厚度，ρ为第一半导体层111的电阻率，J_0为在LED显示设备10正常工作时反射电极图案140所覆盖的第一电流扩散层内的电流密度。可见，横向电流扩散长度Ls随第一半导体层111的厚度t的减小而减小，随第一半导体层111的电阻率ρ的增大而减小，因此可以降低横向电流扩散长度Ls，来使得每个反射电极图案140对应的显示像素的工作电流不会扩散至相邻显示像素，从而实现各显示像素的自隔离。
S220：在外延层背对反射电极图案的一面沉积公共电极层。
进一步地，可以在外延层110背对反射电极图案140的一面沉积第一金属电极层121，使得第一金属电极层121覆盖多个凸台结构115的顶壁和第一凹陷区114，以使得第一金属电极层121完全覆盖多个凸台结构115的顶部和侧壁，以使得第一金属电极层121可以反射凸台结构115的侧壁穿出的漏光。
第一金属电极层121沉积覆盖完成后在背离外延层110的一侧形成第二凹陷区122，而后可以通过电镀的方式在第一金属电极层121的第二凹陷区122内填充第二金属电极层123，以使得第二金属电极层123填充多个凸台结构115之间的缝隙，且第二金属电极层123背对外延层110的顶端超过多个凸台结构115背对反射电极图案140的顶端。进一步地，采用化学机械抛光(CMP)工艺对第二金属电极层123背对外延层110的一面进行处理，使得凸台结构115外露以暴露外延层110的第一半导体层111。采用化学机械抛光(CMP)工艺不仅仅可以去除多余的金属电极层，也可以精确控制第一半导体层111的厚度，从而达到谐振腔所需的厚度要求。
第二金属电极层123与第一金属电极层121可以共同形成公共电极层120，且多个凸台结构115之间的第二金属电极层123完全连在一起，以使得公共电极层120可以视为LED显示设备10的公共电极，并且可以实现良好的电流扩散作用。
其中，第二金属电极层123可以在背对凸台结构115侧壁的部分裸露，在第二金属电极层123的边缘裸露部分可通过打线连接的方式，将第二金属电极层123与驱动基板200的基板通过公共走线300连接，以使得显示基板100的公共电极层120与驱动基板200电连接。在其他的实施方式中，也可以通过TSV孔连接电连接显示基板100的公共电极层120与驱动基板200。
S230：在多个凸台结构的顶壁和公共电极层的顶端沉积一层反射层，以形成多个谐振腔。
在凸台结构115背对反射电极图案140的顶端与第二金属电极的顶端沉积一层反射层130，使得反射层130覆盖凸台结构115的顶壁和公共电极层120。此时多个凸台结构115被第一金属电极、反射层130以及反射电极图案140包裹住，形成多个谐振腔101。其中反射层130的反射率小于所述反射电极图案140的反射率，以使得光线进入谐振腔101后集中从反射层130的一侧面射出。在其他的实施方式中，反射层130背对凸台结构115的一面可以 增加微透镜层，以使出射光的出光角度更加准直。
在完成谐振腔101的制备后，进一步制备LED显示设备10的波长转换层150与彩色滤光层160，以形成彩色的显示像素。
以下以制备红、绿、蓝三种颜色的显示像素，且多个凸台结构115射出的光线为蓝光为例，示例性地描述波长转换层150与彩色滤光层160的制备工艺。
具体地，LED显示设备10的波长转换层150与彩色滤光层160的制备流程可以具有多种实施方式，其中一种实施方式如图10至图11所示，其中图10为本申请波长转换层150与彩色滤光层160的制造方法的一实施方式的流程示意图，图11为与图10所示的流程步骤所对应的制备过程示意图。
S311：在反射层背对凸台结构的表面覆盖波长转换层。
可以通过多个颜色的子波长转换层层叠的方式形成波长转换层150。例如，可以通过沉积的方式率先在反射层130背对凸台结构115的表面覆盖一层绿色的子波长转换层，在形成第一层子波长转换层后进行厚度控制，可以通过热蒸镀、匀胶工艺或通过化学机械抛光(CMP)等工艺精确地控制此子波长转换层的厚度和表面的平整度，以实现整面波长子转换层转换光的波长和强度的均匀性。此时通过多个凸台结构115射出的蓝色的第一光线在通过绿色的子波长转换层后形成蓝色与绿色混色的光线。
而后可以再次通过类似沉积的方式在绿色的波长转换层150表面覆盖一层红色的子波长转换层，继而同样通过热蒸镀、匀胶工艺或通过机械抛光(CMP)等工艺精确地控制此子波长转换层的控制厚度和表面的平整度。此时，两层子波长转换层可共同形成波长转换层150，而从绿色的子波长转换层射出的蓝色、绿色混色的光线通过红色的波子波长转换层之后，可形成蓝色、绿色与红色三色混色的第二光线。
或者，波长转换层150也可以是绿色或红色的量子点材料制作而成的膜片，在LED显示设备10的制备过程中，可以利用光学胶水固定贴合的方式，将波长转换层150贴合固定于反射层130背对凸台结构115的表面，以降低LED显示设备10的制备加工难度。
其中，可以通过控制波长转换层150的制作材料与厚度来调整三色混色的效果。在其他的实施方式中，波长转换层150也可以为绿色和红色的量子点材料混合制作而成的单层波长转换层150，从而实现绿色与红色混色。当然，在其他的实施方式中，可以根据对LED显示设备10射出的光线的需求，增加不同颜色的子波长转换层，或者更改波长转换层150的颜色，以调整第二光线的混色效果。
S312：在波长转换层背离外延层一侧进行显影工艺处理形成对应多个凸台结构的多个彩色滤光图案，以形成彩色滤光层。
制备彩色滤光层160的S312步骤流程包括以下步骤S301-S305，具体如图12至图13所示，其中图12为本申请彩色滤光层160的制造方法一实施方式的流程示意图，图13为图12所示的流程步骤所对应的制备过程示意图。
S301：在波长转换层背离外延层一侧设置黑色矩阵。
具体地，可以在波长转换层150背离外延层110一侧添加低反射率铬或者黑色树脂等黑色基质162，并且黑色基质162在波长转换层150背离外延层110一侧暴露出多个凸台结构115的对应位置以形成黑色矩阵。
S302：在波长转换层背离外延层一侧涂覆彩色光阻层，以覆盖黑色矩阵。
而后在波长转换层150背离外延层110一侧涂覆彩色光阻层163，彩色光阻层163填充黑色矩阵的空隙以及覆盖黑色矩阵。其中，彩色光阻层163的颜色为蓝色、绿色、红色中的一种。
S303：对彩色光阻层的指定位置进行光掩膜曝光。
进一步地，可以对彩色光阻层163的指定位置进行光掩膜曝光，以使得指定位置的彩色光阻层163可以固定于指定位置上。
S304：通过显影去除对彩色光阻层的其他部分并进一步进行烘烤固化以形成多个彩色滤光图案。
可以通过显影液去除的方式，除去不必要部分的彩色光阻层163，以留下指定位置的彩色光阻层163，并且通过烘烤使得指定位置的彩色光阻层163固化，进而形成多个彩色滤光图案161。其中指定位置为对应部分凸台结构115的位置，以使得LED显示设备10在该指定位置可以射出彩色滤光图案161后显示特定颜色的光线。
S305：重复步骤S301至S304，以得到其他颜色的多个彩色滤光图案，形成多种彩色滤光层。
重复2次以上步骤，分别固化另外两种颜色的多个彩色滤光图案161，以形成彩色滤光层160，实现将从波长转换层150射出的混有蓝绿红三色的第二光线过滤，得到单色光的第三光线，并且实现蓝色、绿色、红色三种颜色的分离，使得LED显示设备10的显示像素可以射出不同颜色的光线。
本申请通过完全覆盖波长转换层150，以及在波长转换层150上采用先覆盖后去除的方式制备彩色滤光图案161来制作彩色显示像素，而不需要进行定点喷涂彩色滤光图案161的方式，使得彩色滤光层160和波长转换层150更加均匀平整，也更容易控制波长转换层150和彩色滤光层160的厚度，同时使得制备彩色显示像素的工艺简单化，能够提高生产良率，以使得本申请所述的LED显示设备10便于实现量产。
制得LED显示设备10后，可以根据需求增加其他的工艺步骤，例如图14所示，可以在彩色滤光图案161上添加微透镜164，以在彩色滤光层160形成微透镜阵列，以进一步调控出射光的光型。
此外，还可以采用另一种实施方式制备波长转换层150与彩色滤光层160，具体如图15和图16所示，其中图15为本申请波长转换层150与彩色滤光层160的另一实施方式的制备工艺流程示意图，图16为与图15所示的流程步骤所对应的制备过程示意图。
S321：提供透明基板，在透明基板一侧进行显影工艺处理形成多个彩色滤光图案，以形成彩色滤光层。
提供透明基板190，其中透明基板190可以为不导电的玻璃基板或者亚克力基板等无色的透明基板190，使得透明基板190可以透过光线且不会对光线的颜色造成影响。
根据LED显示设备10的多个凸台结构115的设计，提前确定多种彩色滤光图案161在透明基板190上的具***置以及面积，以制备与多个凸台结构115对应的多种彩色滤光图案161。其中在透明基板190一面制备彩色滤光层160的具体步骤可参考步骤S301-S305，在此不做赘述。其中，可设置多种彩色滤光图案161远离透明基板190的一面与黑色基质162的远离透明基板190的一面平齐，形成一个平整的表面，以便于后续操作。
S322：将波长转换层以整面覆盖的方式设置于彩色滤光层背离透明基板的一侧。
波长转换层150设置于彩色滤光层160背离透明基板190的一侧的制备流程与步骤S311中所描述的波长转换层150制备于反射层130的表面的流程工艺类似，因此可以参考步骤S311，在此不再赘述。
S323：透明基板以波长转换层面对反射层的方式，对位装配固定于反射层背对凸台结构的一侧。
可选地，可采用光学粘附层131粘合的方式，将透明基板190上的波长转换层150固定于反射层130背对凸台结构115的一侧。其中光学粘附层131可以是无色透明、光透过率在90％以上、胶结强度良好且固化收缩小的光学胶，例如有机硅胶、聚氨酯、环氧树脂等粘结剂。如此可以在提高LED显示设备10的稳定性的同时，还可以减少光学粘附层131对反射层130射出的第一光线的影响。
可选地，可先在反射层130背对凸台结构115的一侧涂抹一层光学粘附层131，而后可以将透明基板190倒置，以波长转换层150面对光学粘附层131的方式将波长转换层150贴合光学粘附层131，在贴合过程中需注意将透明基板190上的多个彩色滤光图案161与多个凸台结构115一一对应。之后再进一步固化光学粘附层131，从而固定波长转换层150以及彩色滤光图案161的位置，以完成对位装配固定透明基板190和彩色滤光层160。
此种实施方式得到的LED显示设备10如图17所示，显示基板100进一步包括设置于反射层130背离外延层110一侧的光学粘附层131。光学粘附层131背对反射层130的一侧贴合固定波长转换层150。波长转换层150背对光学粘附层131的一侧设置有多个彩色滤光图案161，以形成彩色滤光层160。其中多个彩色滤光图案161之间通过黑色基质162隔开。彩色滤光层160背对波长转换层150的一侧固定设置有透明基板190。
如此可以使得从多个凸台结构115中射出的第一光线可以通过光学粘附层131进而透过波长转换层150，从而形成蓝、绿、红三色混色的第二光线，而后透过多种彩色滤光图案161，从而过滤第二光线而得到不同颜色的第三光线。第三光线可以进一步透过透明基板190射出外界。
采用此种实施方式不仅可以利用透明基板190隔离保护彩色滤光图案161，还可以使得波长转换层150与彩色滤光层160的制备流程更加易于操作，也可以制备波长转换层150与彩色滤光层160的同时制备LED显示设备10的其他元件，以缩短LED显示设备10的制备 工艺时长。
综上所述，本申请通过在外延层110设置多个凸台结构115以及第一凹陷区114，且在凸台结构115的一侧设置有反射层130并在背对多个反射电极图案140，其中反射层130的反射率小于反射电极图案140的反射率，以形成从反射层130一侧出光的谐振腔101，实现LED显示设备10准直出光，提高出射光的准直性。而且通过热压的方式将显示基板100与驱动基板200对位键合，以实高强度连接。同时采用先覆盖波长转换层150再设置彩色滤光层160的方式制备LED显示设备10的彩色显示像素，使得制备彩色显示像素的工艺简单化，并且能够提高生产良率。
以上仅为本申请的实施方式，并非因此限制本申请的专利范围，凡是利用本申请说明书及附图内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本申请的专利保护范围内。

Claims (11)

  1. 一种LED显示设备，其特征在于，所述LED显示设备包括显示基板，所述显示基板包括：
    外延层，所述外延层包括依次层叠设置的第一半导体层、有源层以及第二半导体层，其中所述第二半导体层在背离所述有源层的一侧设置有第一凹陷区，通过所述第一凹陷区在所述第二半导体层背离所述有源层的一侧限定出间隔排布的多个凸台结构，所述第一凹陷区的深度小于或等于所述第二半导体层的层厚度；
    公共电极层，所述公共电极层填充于所述第一凹陷区内，并与所述多个凸台结构的侧壁接触，所述公共电极层进一步外露所述凸台结构的顶壁；
    反射层，覆盖所述凸台结构的顶壁和所述公共电极层；
    多个反射电极图案，所述多个反射电极图案间隔设置于所述第一半导体层背离所述有源层的一侧，并分别对应于所述多个凸台结构，其中所述反射层的反射率小于所述反射电极图案的反射率，以形成从所述反射层一侧出光的谐振腔。
  2. 根据权利要求1所述的LED显示设备，其特征在于，所述公共电极层环绕所述多个凸台结构，并对所述多个凸台结构的侧壁进行全包围接触。
  3. 根据权利要求1所述的LED显示设备，其特征在于，所述公共电极层包括随形附着于所述多个凸台结构的侧壁和所述第一凹陷区底部的第一金属电极层以及填充于所述第一金属电极层所形成的第二凹陷区内的第二金属电极层；其中，第一金属电极层的反射率大于第二金属电极层的反射率。
  4. 根据权利要求1所述的LED显示设备，其特征在于，所述第一凹陷区的底部所对应的所述第一半导体层和所述有源层内设置有通过离子轰击形成的绝缘区，以使得所述多个凸台结构下方的所述第一半导体层和所述有源层在所述外延层内彼此电性隔离，或者所述第一半导体层的厚度和电阻率设置成使得在所述LED显示设备正常工作时，所述第一半导体层的横向电流扩散长度满足Ls≤1/2×D1，其中Ls为所述第一半导体层的横向电流扩散长度，D1为相邻设置的所述反射电极图案的边缘之间的最短间距。
  5. 根据权利要求1所述的LED显示设备，其特征在于，所述公共电极层背离所述有源层一侧设置成与所述凸台结构的顶壁平齐，并形成一连续平面。
  6. 根据权利要求1所述的LED显示设备，其特征在于，所述显示基板进一步包括设置于所述反射层背离所述外延层一侧的波长转换层以及设置于所述波长转换层背离所述外延层一侧的彩色滤光层，其中所述波长转换层用于将所述凸台结构的顶壁输出的第一光线转换成第二光线，所述彩色滤光层包括分别与所述多个凸台结构对应的设置的多个彩色滤光图案，所述彩色滤光图案用于将所述第二光线过滤成第三光线，至少部分所述彩色滤光图案所形成的所述第三光线的颜色彼此不同。
  7. 根据权利要求6所述的LED显示设备，其特征在于，所述波长转换层以整面覆盖的 方式设置于所述反射层背离所述外延层一侧，所述彩色滤光图案以显影工艺形成于所述波长转换层背离所述外延层一侧。
  8. 根据权利要求6所述的LED显示设备，其特征在于，所述显示基板进一步包括设置于所述反射层背离所述外延层一侧的透明基板，所述波长转换层以整面覆盖的方式设置于所述透明基板背离反射层的一侧，所述彩色滤光图案以显影工艺形成于所述波长转换层背离所述透明基板一侧。
  9. 根据权利要求1所述的LED显示设备，其特征在于，所述显示基板进一步包括第一介质层以及第一转接电极，所述第一介质层覆盖所述第一半导体层背离所述有源层的一侧以及所述反射电极图案，所述第一介质层设置有允许所述反射电极图案外露的第一过孔，所述第一转接电极设置于所述第一过孔内，并与所述反射电极图案导电连接；所述LED显示设备包括驱动基板，所述驱动基板包括第二介质层以及第二转接电极，所述第二介质层设置有第二过孔，所述第二转接电极设置于所述第二过孔内，所述第一介质层与所述第二介质层之间以及所述第一转接电极和第二转接电极之间通过热压方式对位键合。
  10. 根据权利要求9所述的LED显示设备，其特征在于，所述第一转接电极包括靠近所述反射电极图案的第一电极部以及远离所述反射电极图案的第二电极部，所述第二转接电极包括靠近所述第一转接电极的第三电极部以及远离所述第一转接电极的第四电极部，在所述第一半导体层、有源层以及第二半导体层的层叠方向的垂直方向上，所述第一电极部的尺寸小于所述第二电极部的尺寸，所述第四电极部的尺寸小于所述第三电极部的尺寸。
  11. 根据权利要求9所述的LED显示设备，其特征在于，所述LED显示设备进一步包括在所述显示基板和所述驱动基板的外侧将所述公共电极层电连接至所述驱动基板的公共走线。
PCT/CN2023/133010 2022-12-06 2023-11-21 Led显示设备 WO2024120185A1 (zh)

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