A programmable magnetic control fluid micro-display device and its preparation method

Abstract

The present invention specifically discloses a programmable magnetron fluid microdisplay device and display method thereof, comprising a circuit board, a blue light-emitting microLED, and a magnetron light-emitting unit. The magnetron light-emitting unit has a microfluidic channel filled with a base liquid containing a number of low-transmittance magnetic particles and non-magnetic photoluminescent quantum dots. The magnetic particles and photoluminescent quantum dots are both nanometer-sized. Several sets of matching electromagnetic plates are provided on the front and back sides of the microfluidic channel. The electromagnetic plates divide the microfluidic channel into a number of micro-area units corresponding to the sets of electromagnetic plates. Each set of electromagnetic plates is connected to an external device via electrodes provided on the corresponding electromagnetic plates to change the direction of the magnetic field of the corresponding micro-area unit. The present invention controls the direction of the magnetic field of the corresponding micro-area unit by controlling the current flow of the electromagnetic plates, thereby achieving color coding and patterning of the entire panel.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor material display manufacturing, and in particular to a programmable magnetron fluid micro-display device and a preparation method thereof. Background Art

[0002] The spacing of traditional discretely packaged LEDs is usually 1mm to 40mm, which cannot be used as direct light-emitting elements in small-pitch displays. With the continuous development of display technology, the market for small display devices such as AR / VR has expanded rapidly, which in turn puts higher technical requirements on the size of single pixels. When the pixel size of the display device is less than 100nm, traditional LEDs are no longer applicable.

[0003] Micro-LEDs (micro light-emitting diodes) based on the third-generation semiconductor material gallium nitride have the advantages of wide bandgap, high saturated electron migration rate, high thermal conductivity, and small dielectric constant in terms of material properties. In terms of luminous performance, they have the advantages of high luminous efficiency, high brightness, low power consumption, wide color gamut, fast response speed, long service life, and good environmental stability. However, they are still facing the challenge of not being able to maturely realize color display. Among them, the preparation process of blue light Micro-LED is relatively mature, while green and red light Micro-LEDs are expensive, have complex process flows, imperfect technology, and are large in size, resulting in low pixel density and peak luminous efficiency usually below 10%. Using blue light Micro-LEDs to excite photoluminescent quantum dots can produce other colors.

[0004] Traditional quantum dot color conversion technologies include inkjet printing of quantum dots on micro-LED arrays or transparent substrates, and mixing quantum dots with photoresist in a certain proportion and using a variety of photolithography methods to achieve quantum dot patterns. However, inkjet printing relies on nozzles and is more suitable for larger quantum dots. In addition, it is difficult to control the edge morphology of quantum dots using this method. Photolithography can well control the size and morphology of quantum dots. However, since quantum dots need to be mixed with composite materials such as photoresist for photolithography and development, a large amount of quantum dots are wasted, and photoresist has a great influence on the fluorescence efficiency of quantum dots.

[0005] Microfluidic technology requires fewer quantum dots, which can effectively save costs; the fluid flow of quantum dots is very stable within a tiny scale and can be directional controlled, so it has extremely high display potential; in addition, the microfluidic channel size is relatively small, which can effectively save area and achieve miniaturization and high integration. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a programmable magnetron fluid microdisplay device based on the combination of Micro-LED and magnetron fluid technology and a preparation method thereof, including a circuit board, on which a blue light MicroLED is provided, and a magnetron light-emitting unit is stacked and connected on the blue light MicroLED. The magnetron light-emitting unit has a microfluidic channel, and the microfluidic channel is filled with a base liquid. The base liquid contains a plurality of magnetic particles with low transmittance and non-magnetic photoluminescent quantum dots. The magnetic particles and photoluminescent quantum dots are both nanometer-scale particles. Several groups of matching electromagnetic plates are provided on the front and back sides of the microfluidic channel. The electromagnetic plates divide the microfluidic channel into several micro-area units corresponding to the several groups of electromagnetic plates one by one, and each group of electromagnetic plates is connected to an external power supply through electrodes provided on the corresponding electromagnetic plates to change the magnetic field direction of the corresponding micro-area unit.

[0007] Preferably, the base liquid filled in the microfluidic channel is injected by injection, and the base liquid is a high-boiling-point organic solvent that can well carry the magnetic particles and the photoluminescent quantum dots.

[0008] Preferably, the plurality of groups of electromagnetic plates are individually connected to the outside to independently control the magnetic field directions of the corresponding micro-area units to realize color display and non-color display of the corresponding micro-area units.

[0009] Preferably, the circuit board is connected to the blue light MicroLED through electrode bonding.

[0010] Preferably, the size of the blue light MicroLED is 85-95 microns, and the size of the electromagnetic plates is consistent with that of the blue light MicroLED. Each electromagnetic plate includes a micro iron core and several turns of coils, and the several turns of coils are wound around the surface of the micro iron core. The coils are connected to an external power supply to generate a uniform magnetic field perpendicular to the flow direction of the base liquid in the microfluidic channel.

[0011] Preferably, the particle size of the magnetic particles and the photoluminescent quantum dots is no greater than 100 nanometers.

[0012] The present invention also provides a method for preparing a programmable magnetron fluid micro-display device. The method is used to prepare the programmable magnetron fluid micro-display device, comprising the following steps:

[0013] S1. Prepare a magnetically controlled light-emitting unit with a microfluidic channel;

[0014] S2, preparing blue light MicroLED;

[0015] S3. Connect the blue light-emitting microLED prepared in step S2 to a circuit board through electrode bonding, and stack the magnetic control light-emitting unit prepared in step S1 on the blue light-emitting microLED. Then, install corresponding electromagnetic plates on the front and back sides of the magnetic control light-emitting unit based on the number of micro-area units in the magnetic control fluid channel.

[0016] S4. Injecting the base liquid, magnetic particles and photoluminescent quantum dots into the microfluidic channel to obtain a programmable magnetron fluid microdisplay device.

[0017] Preferably, the step S1 specifically includes:

[0018] S11, cleaning the surface of the glass substrate by degreasing, polishing, and pickling and washing, and uniformly coating a photoresist with a preset thickness and good viscosity on the treated surface of the glass substrate;

[0019] S12, setting the microfluidic channel and transferring it to a chrome-coated glass plate or plastic film mask via laser direct writing technology;

[0020] S13, placing a mask on top of the photoresist and in close contact with it, exposing it to ultraviolet light to solidify the microfluidic channel forming area, and protecting the non-microfluidic channel forming area with the opaque mask;

[0021] S14, immersing it in a developer and etching the resin area not exposed to the ultraviolet light, thereby obtaining a resin positive mold with a microfluidic structure;

[0022] S15, treating the resin male mold with silane to facilitate subsequent demoulding;

[0023] S16, pouring a mixture of liquid PDMS and a cross-linking agent into the resin positive mold, and then removing it from the resin positive mold after curing by high-temperature heating to obtain a PDMS block with a microfluidic channel;

[0024] S17. Plasma treatment is performed on the surface of the PDMS block with the microfluidic channel and the glass slide to achieve permanent bonding, thereby obtaining a magnetically controlled light-emitting unit with a microfluidic channel.

[0025] Preferably, the step S2 specifically includes:

[0026] S21, using PECVD technology to grow a SiO2 sacrificial layer on the sapphire-based GaN epitaxial wafer;

[0027] S22. Using FIB technology, etching is performed to form an array of nanopillars penetrating the SiO2 sacrificial layer, the ITO conductive layer, the p-type gallium nitride layer, the quantum well active layer, and extending deep into the n-type gallium nitride layer;

[0028] S23, using a wet etching method to remove impurity particles around the nanopillars and repair etching damage on the sidewalls of the gallium nitride and quantum well active layers;

[0029] S24, spin-coating SiO2 using the solution gel method to ensure that the nanopillars are filled;

[0030] S25. Using ICP technology, the SiO2 layer is thinned to expose the ITO layer on top of the nanopillars while ensuring that the ITO layer is not completely etched.

[0031] S26, using electron beam evaporation technology to evaporate an ITO conductive layer on the top of the nanorod, and perform a rapid annealing process to form an ohmic contact with the p-type gallium nitride;

[0032] S27, preparing an n-type gallium nitride electrode contact window, spin-coating a photoresist on the ITO conductive layer, and pre-baking it, then using ultraviolet lithography to expose the area near the nanopillars to form a pattern, and then developing and post-baking it; then using IBE technology to etch the ITO conductive layer and using ICP technology to etch the SiO2 layer until the n-type gallium nitride layer is exposed, thereby obtaining an n-type gallium nitride electrode contact window;

[0033] S28, using thermal evaporation technology to evaporate a layer of metal as an n-type electrode, and then stripping off the photoresist and the metal on the photoresist layer, washing and drying the sample;

[0034] S29, preparing a p-type electrode contact window, spin-coating a photoresist on the ITO conductive layer, performing a pre-bake, and using ultraviolet lithography to expose the area near the nanopillars to form a pattern, followed by development and post-bake;

[0035] S30: Use thermal evaporation technology to evaporate a layer of metal as a p-type conductive electrode, and then strip off the photoresist and the metal on the photoresist layer, wash and dry the sample, and then obtain a blue light MicroLED.

[0036] The present invention also provides a display method for a programmable magnetron fluid microdisplay device, which is based on the above-mentioned programmable magnetron fluid microdisplay device or the programmable magnetron fluid microdisplay device prepared above. The display method is specifically as follows: first, a circuit board is used to control the emission of blue light MicroLEDs, and at the same time, the electrodes provided on the electromagnetic plates are connected to an external power supply. Then, based on the display requirements of the programmable magnetron fluid microdisplay device, the current flow directions of several groups of electromagnetic plates are combined and controlled, thereby controlling the magnetic field directions of the micro-area units corresponding to the several groups of electromagnetic plates, so that the magnetic particles inside the micro-area units gather to one side and do not display color, and the photoluminescent quantum dots gather to the other side and undergo color conversion and display color, thereby achieving patterning of the entire panel by color coding different micro-area units.

[0037] Compared with the prior art, the present invention provides a programmable magnetron fluid microdisplay device and its preparation method, which uses a circuit board to control the emission of blue light MicroLEDs. At the same time, by combining the current flow directions of several groups of electromagnetic plates, the magnetic field direction of the micro-area units corresponding to each group of electromagnetic plates is controlled. As a result, the magnetic particles inside the micro-area units corresponding to each group of electromagnetic plates gather to one side and do not display color, while the photoluminescent quantum dots gather to the other side and undergo color conversion and display color, thereby achieving patterning of the entire panel by color coding different micro-area units. Moreover, because the photoluminescent quantum dots are nanometer-sized particles, the display method of the programmable magnetron fluid microdisplay device has a very high response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic structural diagram of a programmable magnetic control fluid micro-display device in the present invention.

[0039] Figure 2 This is a schematic diagram of the internal structure of the micro-area unit when no magnetic field is applied in the present invention.

[0040] Figure 3 This is a diagram of the internal structure of the micro-area unit when a magnetic field is applied in the present invention.

[0041] Figure 4 yes Figure 1 Bottom view of the PCB, with the electromagnetic plate removed.

[0042] Figure 5 This is a color coding schematic diagram based on the three micro-region units in the microfluidic channel.

[0043] Figure 6 This is a flow chart of a method for preparing a programmable magnetron fluid micro-display device in the present invention.

[0044] In the figure: 1. Circuit board, 2. Blue light Micro-LED, 3. Microfluidic channel, 4. Electromagnetic plate, 5. Magnetic particles, 6. Photoluminescent quantum dots. DETAILED DESCRIPTION

[0045] To facilitate understanding of the structure and operation of the present invention, the following text provides a more comprehensive and detailed description of the present invention in conjunction with the accompanying drawings and optimized embodiments. However, the scope of protection of the present invention is not limited to the following specific embodiments. It should be noted that the structural features and component dimensions of the embodiments of the present invention may be modified, the connection methods may be replaced, and the device size may be changed without affecting the use effect.

[0046] Unless otherwise defined, all professional terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are merely for the convenience of distinguishing the corresponding components. Similarly, words such as "one" or "an" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "connect" or "connected" are not limited to direct connections, but may be indirectly connected through other intermediate connectors. "Above", "below", "one side", "the other side", "vertical", "horizontal" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship also changes accordingly.

[0047] like Figure 1-Figure 5 As shown, the present invention provides a programmable magnetron fluid microdisplay device and a preparation method thereof, comprising a circuit board 1, on which a blue light MicroLED 2 is provided, and a magnetron light-emitting unit is stacked and connected on the blue light MicroLED 2. The magnetron light-emitting unit has a microfluidic channel 3, and the microfluidic channel 3 is filled with a base liquid. The base liquid contains a plurality of magnetic particles 5 with low transmittance and non-magnetic photoluminescent quantum dots 6. The magnetic particles 5 and the photoluminescent quantum dots 6 are both nanometer-scale particles. The front and back sides of the microfluidic channel 3 are provided with a plurality of groups of matching electromagnetic plates 4. The electromagnetic plates 4 divide the microfluidic channel 3 into a plurality of micro-area units corresponding to the plurality of groups of electromagnetic plates 4 one-to-one, and each group of electromagnetic plates 4 is connected to an external power supply through electrodes provided on the corresponding electromagnetic plates 4 to change the magnetic field direction of the corresponding micro-area unit.

[0048] The base liquid filled in the microfluidic channel 3 is injected by injection. The base liquid is a high-boiling-point organic solvent that can well carry the magnetic particles 5 and the photoluminescent quantum dots 6. By using the high-boiling-point organic solvent as the microfluidic base liquid in the microfluidic channel 3, the magnetic particles 5 and the photoluminescent quantum dots 6 can be well carried. The high-boiling-point organic solvent has good volatility. The conventional method is used to prepare the microfluid so that the magnetic particles in the microfluidic base liquid have the characteristics of fast response speed to the magnetic field and high clarity. At the same time, the color can also be changed by changing the particle size of the photoluminescent quantum dots 6 in the base liquid.

[0049] The circuit board 1 is connected to the blue light MicroLED 2 through electrode bonding, and the light emission of the blue light MicroLED is controlled by the circuit board 1.

[0050] Among them, the size of the blue light MicroLED2 is 85-95 microns, and the size of the electromagnetic plate 4 is consistent with the blue light MicroLED2. Each electromagnetic plate 4 includes a micro magnet and several turns of coils. The several turns of coils are wound around the surface of the micro magnet, and the coils are connected to an external power supply to generate a uniform magnetic field perpendicular to the flow direction of the base liquid in the microfluidic channel 3.

[0051] The particle sizes of the magnetic particles 5 and the photoluminescent quantum dots 6 are both no larger than 100 nanometers. By controlling the ion dispersion process, the particle size distribution range and size of the photoluminescent quantum dots 6 can be controlled, thereby controlling the luminescent color.

[0052] The plurality of groups of electromagnetic plates 4 are individually connected to the outside to independently control the magnetic field directions of the corresponding micro-area units to realize color display and non-color display of the corresponding micro-area units.

[0053] In this embodiment, the circuit board 1 is an integrated circuit (IC) circuit board. By controlling the current flow of multiple sets of electromagnetic plates 4, and thereby controlling the magnetic field directions of the corresponding micro-area units, the magnetic particles 5 within the micro-area units are caused to aggregate toward one side and not display color, while the photoluminescent quantum dots 6 are caused to aggregate toward the other side and undergo color conversion and display. This allows for patterning of the entire panel through color coding of different micro-area units, resulting in a fast response speed.

[0054] like Figure 6 As shown, the present invention also provides a method for preparing a programmable magnetron fluid micro-display device. The programmable magnetron fluid micro-display device is prepared based on the preparation method, comprising the following steps:

[0055] S1. Prepare a magnetically controlled light-emitting unit with a microfluidic channel 3, specifically comprising:

[0056] S11, cleaning the surface of the glass substrate by degreasing, polishing, and pickling and washing, and uniformly coating a photoresist with a preset thickness and good viscosity on the treated surface of the glass substrate;

[0057] S12, setting the microfluidic channel 3 and transferring it to a chrome-coated glass plate or plastic film mask by laser direct writing technology;

[0058] S13, placing a mask on top of the photoresist and in close contact with it, exposing it to ultraviolet light to solidify the microfluidic channel forming area, and protecting the non-microfluidic channel forming area with the opaque mask;

[0059] S14, immersing it in a developer and etching the resin area not exposed to the ultraviolet light, thereby obtaining a resin positive mold with a microfluidic structure;

[0060] S15, treating the resin male mold with silane to facilitate subsequent demoulding;

[0061] S16, pouring a mixture of liquid PDMS and a cross-linking agent into the resin positive mold, and then removing it from the resin positive mold after curing by high-temperature heating to obtain a PDMS block with a microfluidic channel 3;

[0062] S17, performing plasma treatment on the surface of the PDMS block having the microfluidic channel and the glass slide to achieve permanent bonding, thereby obtaining a magnetron light-emitting unit having the microfluidic channel 3;

[0063] S2. Prepare blue light MicroLED 2, specifically including:

[0064] S21, using PECVD technology to grow a SiO2 sacrificial layer on the sapphire-based GaN epitaxial wafer;

[0065] S22. Using FIB technology, etching is performed to form an array of nanopillars penetrating the SiO2 sacrificial layer, the ITO conductive layer, the p-type gallium nitride layer, the quantum well active layer, and extending deep into the n-type gallium nitride layer;

[0066] S23, using a wet etching method to remove impurity particles around the nanopillars and repair etching damage on the sidewalls of the gallium nitride and quantum well active layers;

[0067] S24, spin-coating SiO2 using the solution gel method to ensure that the nanopillars are filled;

[0068] S25. Using ICP technology, the SiO2 layer is thinned to expose the ITO layer on top of the nanopillars while ensuring that the ITO layer is not completely etched.

[0069] S26, using electron beam evaporation technology to evaporate an ITO conductive layer on the top of the nanorod, and perform a rapid annealing process to form an ohmic contact with the p-type gallium nitride;

[0070] S27, preparing an n-type gallium nitride electrode contact window, spin-coating a photoresist on the ITO conductive layer, and pre-baking it, then using ultraviolet lithography to expose the area near the nanopillars to form a pattern, and then developing and post-baking it; then using IBE technology to etch the ITO conductive layer and using ICP technology to etch the SiO2 layer until the n-type gallium nitride layer is exposed, thereby obtaining an n-type gallium nitride electrode contact window;

[0071] S28, using thermal evaporation technology to evaporate a layer of metal as an n-type electrode, and then stripping off the photoresist and the metal on the photoresist layer, washing and drying the sample;

[0072] S29, preparing a p-type electrode contact window, spin-coating a photoresist on the ITO conductive layer, performing a pre-bake, and using ultraviolet lithography to expose the area near the nanopillars to form a pattern, followed by development and post-bake;

[0073] S30, using thermal evaporation technology to deposit a layer of metal as a p-type conductive electrode, and then stripping off the photoresist and the metal on the photoresist layer, washing and drying the sample, thereby obtaining a blue light MicroLED2;

[0074] S3. Connect the blue MicroLED 2 prepared in step S2 to the circuit board 1 through electrode bonding, and stack the magnetic control light-emitting unit prepared in step S1 on the blue MicroLED 2. Then, install corresponding electromagnetic plates 4 on the front and back sides of the magnetic control light-emitting unit based on the number of micro-area units in the magnetic control fluid channel 3.

[0075] S4. Injecting the base liquid, magnetic particles 5 and photoluminescent quantum dots 6 into the microfluidic channel 3 to obtain a programmable magnetron fluid microdisplay device.

[0076] In this embodiment, based on the description of the beneficial technical effects of the programmable magnetron fluid microdisplay device described above, the programmable magnetron fluid microdisplay device prepared by the programmable magnetron fluid microdisplay device preparation method has the same technical effects, which will not be repeated here.

[0077] like Figure 1-Figure 5 As shown, the present invention also provides a display method of a programmable magnetron fluid microdisplay device, which is based on the above-mentioned programmable magnetron fluid microdisplay device or the above-mentioned programmable magnetron fluid microdisplay device for display. The display method is specifically as follows: first, using the circuit board 1 to control the emission of the blue light icroLED 2, and at the same time, the electrodes provided on the electromagnetic plate 4 are connected to the external power supply. Then, based on the display requirements of the programmable magnetron fluid microdisplay device, the current flow direction of several groups of electromagnetic plates 4 is combined and controlled, and then the magnetic field direction of the micro-area units corresponding to the several groups of electromagnetic plates 4 is controlled, so that the magnetic particles 5 inside the micro-area units are aggregated to one side and do not display color, and the photoluminescent quantum dots 6 are aggregated to the other side and are caused to undergo color conversion and display color, thereby achieving patterning of the entire panel by color coding different micro-area units.

[0078] In this embodiment, the display method of the programmable magnetron fluid micro-display device has the same beneficial technical effects as the programmable magnetron fluid micro-display device described above, which will not be described in detail here.

[0079] In order to better illustrate the working principle and technical effect of the present invention, the color coding of the three micro-region units in the microfluidic channel 3 is used for illustration.

[0080] like Figure 5 As shown in the figure, the gray part 1 represents the colored micro-region, and the black part 0 represents the non-colored micro-region. By controlling the current flow direction of the electromagnetic plates 4 corresponding to the three micro-region units, the magnetic field direction of the three micro-region units is controlled, forming 8 color codes, namely 111, 110, 101, 011, 001, 000, 010 and 100. Therefore, based on several groups of electromagnetic plates 4, the microfluidic channel 3 is divided into several micro-region units, and the color coding of the entire panel can be achieved, thereby realizing the patterning of the entire panel.

[0081] The above describes in detail a programmable magnetic fluid microdisplay device and its preparation method provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A programmable magnetic control fluid micro-display device, characterized in that: The invention comprises a circuit board (1), wherein a blue light Micro LED (2) is provided on the circuit board (1), a magnetron light emitting unit is stacked and connected on the blue light Micro LED (2), a microfluidic channel (3) is provided in the magnetron light emitting unit, the microfluidic channel (3) is filled with a base liquid, and the base liquid contains a plurality of magnetic particles (5) with low light transmittance and non-magnetic photoluminescent quantum dots (6), wherein the magnetic particles (5) and the photoluminescent quantum dots (6) are both nanometer-scale particles, and a plurality of groups of matching electromagnetic plates (4) are provided on the front and back sides of the microfluidic channel (3), the electromagnetic plates (4) divide the microfluidic channel (3) into a plurality of micro-region units corresponding to the plurality of groups of electromagnetic plates (4), and each group of electromagnetic plates (4) is connected to an external power supply through an electrode provided on the corresponding electromagnetic plate (4) for changing the magnetic field direction of the corresponding micro-region unit, wherein the preparation method of the programmable magnetron fluid micro display device specifically comprises the following steps: S1. Prepare a magnetically controlled light-emitting unit with a microfluidic channel, specifically comprising: S11, cleaning the surface of the glass substrate by degreasing, polishing, and pickling and washing, and uniformly coating a photoresist with a preset thickness and good viscosity on the treated surface of the glass substrate; S12, setting the microfluidic channel and transferring it to a chrome-coated glass plate or plastic film mask via laser direct writing technology; S13, placing a mask on top of the photoresist and in close contact with it, exposing it to ultraviolet light to solidify the microfluidic channel forming area, and protecting the non-microfluidic channel forming area with the opaque mask; S14, immersing it in a developer and etching the resin area not exposed to the ultraviolet light, thereby obtaining a resin positive mold with a microfluidic structure; S15, treating the resin male mold with silane to facilitate subsequent demoulding; S16, pouring a mixture of liquid PDMS and a cross-linking agent into the resin positive mold, and then removing it from the resin positive mold after curing by high-temperature heating to obtain a PDMS block with a microfluidic channel; S17, performing plasma treatment on the surface of the PDMS block having the microfluidic channel and the glass slide to achieve permanent bonding, thereby obtaining a magnetically controlled light-emitting unit having the microfluidic channel; S2, preparing blue light Micro LED; S3. Connect the blue Micro LED prepared in step S2 to a circuit board through electrode bonding, and stack the magnetic control light-emitting unit prepared in step S1 on the blue Micro LED. Then, install corresponding electromagnetic plates on the front and back sides of the magnetic control light-emitting unit based on the number of micro-area units in the magnetic control fluid channel. S4. Injecting the base liquid, magnetic particles and photoluminescent quantum dots into the microfluidic channel to obtain a programmable magnetron fluid microdisplay device.

2. The programmable magnetic control fluid micro-display device according to claim 1, characterized in that: The base liquid filled in the microfluidic channel (3) is injected by injection, and the base liquid is a high-boiling-point organic solvent that can well carry the magnetic particles (5) and the photoluminescent quantum dots (6).

3. The programmable magnetic control fluid micro-display device according to claim 2, characterized in that: Several groups of electromagnetic plates (4) are individually connected to the outside to independently control the magnetic field direction of the corresponding micro-area unit to realize color display and non-color display of the corresponding micro-area unit.

4. The programmable magnetic control fluid micro-display device according to claim 3, characterized in that: The circuit board (1) and the blue light Micro LED (2) are connected via electrode bonding.

5. The programmable magnetic control fluid micro-display device according to claim 4, characterized in that: The size of the blue light MicroLED (2) is 85-95 microns, and the size of the electromagnetic plate (4) is consistent with that of the blue light MicroLED (2). Each electromagnetic plate (4) includes a micro iron core and a plurality of turns of coils, and the plurality of turns of coils are wound around the surface of the micro iron core, and the coils are connected to an external power supply to generate a uniform magnetic field perpendicular to the flow direction of the base liquid in the microfluidic channel (3).

6. The programmable magnetic control fluid micro-display device according to claim 5, characterized in that: The particle sizes of the magnetic particles (5) and the photoluminescent quantum dots (6) are both no greater than 100 nanometers.

7. The programmable magnetic control fluid micro-display device according to claim 6, characterized in that: The step S2 specifically includes: S21, using PECVD technology to grow a SiO2 sacrificial layer on the sapphire-based GaN epitaxial wafer; S22. Using FIB technology, etching is performed to form an array of nanopillars penetrating the SiO2 sacrificial layer, the ITO conductive layer, the p-type gallium nitride layer, the quantum well active layer, and extending deep into the n-type gallium nitride layer; S23, using a wet etching method to remove impurity particles around the nanopillars and repair etching damage on the sidewalls of the gallium nitride and quantum well active layers; S24, spin-coating SiO2 using the solution gel method to ensure that the nanopillars are filled; S25. Using ICP technology, the SiO2 layer is thinned to expose the ITO layer on top of the nanopillars while ensuring that the ITO layer is not completely etched. S26, using electron beam evaporation technology to evaporate an ITO conductive layer on the top of the nanorod, and perform a rapid annealing process to form an ohmic contact with the p-type gallium nitride; S27, preparing an n-type gallium nitride electrode contact window, spin-coating a photoresist on the ITO conductive layer, and pre-baking it, then using ultraviolet lithography to expose the area near the nanopillars to form a pattern, and then developing and post-baking it; then using IBE technology to etch the ITO conductive layer and using ICP technology to etch the SiO2 layer until the n-type gallium nitride layer is exposed, thereby obtaining an n-type gallium nitride electrode contact window; S28, using thermal evaporation technology to evaporate a layer of metal as an n-type electrode, and then stripping off the photoresist and the metal on the photoresist layer, washing and drying the sample; S29, preparing a p-type electrode contact window, spin-coating a photoresist on the ITO conductive layer, performing a pre-bake, and using ultraviolet lithography to expose the area near the nanopillars to form a pattern, followed by development and post-bake; S30: Use thermal evaporation technology to evaporate a layer of metal as a p-type conductive electrode, and then peel off the photoresist and the metal on the photoresist layer, wash and dry the sample, and then obtain a blue light Micro LED.

8. A display method for a programmable magnetic control fluid micro-display device, characterized in that: The display is performed based on the programmable magnetron fluid microdisplay device according to any one of claims 1 to 7. The display method is specifically as follows: first, a circuit board is used to control the emission of blue light Micro LEDs, and at the same time, electrodes arranged on the electromagnetic plates are connected to an external power supply. Then, based on the display requirements of the programmable magnetron fluid microdisplay device, the current flow directions of several groups of electromagnetic plates are combined and controlled, thereby controlling the magnetic field directions of the micro-area units corresponding to the several groups of electromagnetic plates, so that the magnetic particles inside the micro-area units gather to one side and do not display color, and the photoluminescent quantum dots gather to the other side and undergo color conversion and display, thereby achieving patterning of the entire panel by color coding different micro-area units.

Images