LED Transfer Device and LED Transfer Method

Abstract

The present application provides an LED transfer device and an LED transfer method. The LED transfer device includes: a photothermal conversion layer that can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of polarized light; a light source located on one side of the photothermal conversion layer and used to generate polarized light; and an adsorption layer formed on a surface of the photothermal conversion layer away from the light source. The adsorption layer has elasticity and can switch between an adhesion state and a de-adhesion state. When the adsorption layer is in a magnetic field-free environment, the adsorption layer is in an adhesion state, and the adsorption layer in the adhesion state has adhesiveness. And when the adsorption layer is in a magnetic field environment, the adsorption layer is in a de-adhesion state, and the adsorption layer in the de-adhesion state does not have adhesiveness. The LED transfer device and the LED transfer method provided by the present application can break through the mass transfer technology and reduce the manufacturing process difficulty of Micro LED.

Description

Technical Field

[0001] The present application relates to the technical field of LED transfer, and particularly relates to an LED transfer device and an LED transfer method. Background Art

[0002] In recent years, due to its outstanding advantages and rapid development, Mini-LED / Micro-LED display technology has become a hot spot for major panel manufacturers. Compared with current LCD and OLED display devices, both have advantages such as fast response, high color gamut, high PPI, low energy consumption, accurate dimming with an ultra-high number of partitions, and ultra-high contrast. Mini-LED display: Miniaturized RGB tri-color LEDs are integrated into each pixel-addressable LED display driving circuit to form an LED array, realizing miniaturized LED display; Micro LED display: The principle is the same as that of Mini LED, the difference is that the Micro LED chip is smaller, and the LED chips are transferred to the substrate through mass transfer technology; Micro LED has higher brightness, better luminous efficiency, and lower power consumption than the existing OLED technology. The manufacturing process of MicroLED is difficult. How to break through the mass transfer technology is the key to its mass production and large-scale production. Summary of the Invention

[0003] Therefore, the present application provides an LED transfer device and an LED transfer method that can break through the mass transfer technology, reduce the manufacturing process difficulty of Micro LED, and achieve mass production and large-scale production.

[0004] In a first aspect, the present application provides an LED transfer device, including:

[0005] A photothermal conversion layer that can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of the polarized light;

[0006] A light source located on one side of the photothermal conversion layer and used to generate polarized light; and

[0007] An adsorption layer formed on the surface of the photothermal conversion layer away from the light source; the adsorption layer has elasticity and has an adhesion state and a de-adhesion state; wherein,

[0008] When the adsorption layer is in a magnetic field-free environment, the adsorption layer is in an adhesion state, and the adsorption layer in the adhesion state has adhesiveness; and

[0009] When the adsorption layer is in a magnetic field environment, the adsorption layer is in a de-adhesion state, and the adsorption layer in the de-adhesion state does not have adhesiveness.

[0010] In an optional embodiment of the present application, the material of the light-to-heat conversion layer is a polarization-driven multi-directional controllable soft composite material; the light-to-heat conversion layer includes:

[0011] Polydimethylsiloxane film layer;

[0012] A polyimide film layer; and

[0013] A polyacrylamide film layer is located between the polydimethylsiloxane film layer and the polyimide film layer; the polyimide film layer faces the adsorption layer;

[0014] The polyacrylamide film layer includes a polyacrylamide polymer and first nanorods dispersed in the polyacrylamide polymer, and the material of the first nanorods is a Fe3O4-SiO2 coating composite modified by Au-polyvinyl pyrrolidone-phenolic condensation polymer.

[0015] In an optional embodiment of the present application, the material of the adsorption layer is a magnetron adhesion-deadhesion organic-inorganic composite material, the adsorption layer includes polyurethane and ferroferric oxide particles, the ferroferric oxide particles are mixed with the polyurethane, and the polyurethane has multiple hydrogen bonds.

[0016] In an optional embodiment of the present application, in the adsorption layer, the percentage of the ferrosoferric oxide particles is 1%-20%, and the rest is the polyurethane.

[0017] In an optional embodiment of the present application, the LED transfer device further includes:

[0018] A plurality of spacers are sequentially fixed on a side of the light-to-heat conversion layer away from the adsorption layer; wherein,

[0019] The plurality of spacers are opaque, and a cavity is formed between two adjacent spacers; the light source faces the cavity; and

[0020] Under the irradiation of the polarized light generated by the light source, the light-to-heat conversion layer corresponding to the cavity is deformed; under the action of the magnetic field, the portion of the adsorption layer facing the cavity is synchronously deformed and changes from an adhered state to a de-adhesive state.

[0021] In an optional embodiment of the present application, the light source is located inside the cavity or outside the cavity.

[0022] In an optional embodiment of the present application, the LED transfer device further includes:

[0023] At least one transparent elastic body covers one end of the cavity and is fixed on one end of the spacer away from the light-to-heat conversion layer.

[0024] Second aspect, the present application also provides a method for transferring LEDs. The method for transferring LEDs is implemented by an LED transfer device. Wherein, the LED includes: a light source, a photo-thermal conversion layer, an adsorption layer, and a spacer; the light source is located on one side of the photo-thermal conversion layer, the adsorption layer is formed on a surface of the photo-thermal conversion layer away from the light source, a plurality of the spacers are light-impermeable and are sequentially fixed on a side of the photo-thermal conversion layer away from the adsorption layer, and a cavity is formed between two adjacent spacers, and the light source is facing the cavity; wherein, the method for transferring LEDs includes:

[0025] Moving the LED transfer device in its initial state to directly above the target LED;

[0026] Continuing to move the LED transfer device so that the adsorption layer in the adhesion state contacts the target LED, and the adsorption layer adheres to the target LED; wherein, one cavity corresponds to one target LED;

[0027] Transferring the target LED above a receptor substrate, and controlling the light source to emit polarized light, and the photo-thermal conversion layer corresponding to at least one of the cavities deforms under the irradiation of the polarized light;

[0028] Placing the target LED that needs to be de-adhered in a magnetic field, and the deformed adsorption layer changes from the adhesion state to the de-adhesion state under the action of the magnetic field, and the target LED located at the deformed adsorption layer is completely de-adhered; and

[0029] Moving the LED transfer device away from the receptor substrate; meanwhile, the deformed part of the photo-thermal conversion layer and the adsorption layer recover from the deformation, and the adsorption layer changes from the de-adhesion state back to the adhesion state.

[0030] In an optional embodiment of the present application, the material of the photo-thermal conversion layer is a polarization-driven multi-directional controllable soft composite material; the adsorption layer includes:

[0031] A polydimethylsiloxane film layer;

[0032] A polyimide film layer; and

[0033] A polyacrylamide film layer, located between the polydimethylsiloxane film layer and the polyimide film layer; the polyimide film layer faces the adsorption layer;

[0034] Wherein, the polyacrylamide film layer includes the polyacrylamide polymer and first nanorods dispersed in the polyacrylamide polymer, and the material of the first nanorods is an Au-polyvinylpyrrolidone-phenolic resin-modified Fe3O4-SiO2 coating composite.

[0035] In an optional embodiment of the present application, the material of the adsorption layer is a magnetically controlled adhesion-deadhesion organic-inorganic composite material. The adsorption layer includes polyurethane and iron oxide particles. The iron oxide particles are mixed with the polyurethane, and there are various hydrogen bonds between the polyurethanes. In the adsorption layer, the percentage of the iron oxide particles is 1%-20%, and the rest is the polyurethane.

[0036] The LED transfer device and the LED transfer method provided by the present application are as follows: 1) The LED transfer device includes a photothermal conversion layer and an adsorption layer. The photothermal conversion layer can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of the polarized light. By regulating the magnetic field, the adsorption layer can be switched between an adhesion state and a deadhesion state, so that the LED transfer device can adhere to multiple target LEDs in a magnetic field-free state, and can be simultaneously deadhesioned from multiple target LEDs in a magnetic field state, thereby improving the efficiency and accuracy of transferring LEDs. Therefore, the LED transfer device provided by the present application can break through the mass transfer technology and reduce the manufacturing process difficulty of Micro LEDs, realizing mass production and large-scale production. 2) A polyacrylamide film layer is prepared by using an Fe3O4-SiO2 coating composite modified with Au-polyvinylpyrrolidone-phenolic resin condensate and a polyacrylamide polymer, and then a polarization-driven multi-directionally controllable soft composite material is prepared by using the polyacrylamide film layer, a polydimethylsiloxane film layer and a polyimide film layer to obtain the photothermal conversion layer. The photothermal effect of the light-absorbing material of the polarization-driven multi-directionally controllable soft composite material can convert light energy into mechanical deformation, which has the advantages of precision, remote control and rapidity compared with other driving methods. 3) The magnetically controlled adhesion-deadhesion organic-inorganic composite material is prepared by using polyurethane and iron oxide particles. Due to the existence of various hydrogen bond interactions in the polyurethane, the organic-inorganic composite material itself has good adhesion. In particular, when the organic-inorganic composite material is placed in an oscillating magnetic field, the iron oxide particles therein will be coupled with the magnetic field to generate a hysteresis heat effect, so that the temperature of the organic-inorganic composite material rises, further weakening the hydrogen bonds between the polyurethane molecules, thereby realizing the deadhesion of the organic-inorganic composite material from the adhered surface. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of the film layer of the LED transfer device provided by a preferred embodiment of the present application.

[0039] Figure 2 Flow chart of the LED transfer method provided by a preferred embodiment of the present application.

[0040] Figure 3 For corresponding Figure 2 Schematic diagram of step S1.

[0041] Figure 4 For corresponding Figure 2 Schematic diagram of step S2.

[0042] Figure 5 For corresponding Figure 2 Schematic diagram of step S3.

[0043] Figure 6 For corresponding Figure 2 Schematic diagram of step S4.

[0044] Figure 7 For corresponding Figure 2 Schematic diagram of "Moving the LED transfer device away from the receptor substrate" in step S5.

[0045] Figure 8 For corresponding Figure 2 Schematic diagram of "Meanwhile, the deformed part of the photothermal conversion layer and the adsorption layer recover their deformation, and the adsorption layer changes from the de-adhesion state to the adhesion state" in step S5. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0047] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0048] This application may repeatedly refer to numerical references and / or alphabetical references in different embodiments. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or arrangements being discussed.

[0049] In view of the technical problem of the high difficulty of the existing Micro LED manufacturing process, this application provides an LED transfer device and an LED transfer method. The LED transfer device includes a photothermal conversion layer and an adsorption layer. The photothermal conversion layer can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of the polarized light. By regulating the magnetic field, the adsorption layer can be switched between an adhesion state and a de-adhesion state, so that the LED transfer device can adhere to the target LED in a magnetic field-free state and can be de-adhered from the LED in a magnetic field state, thereby improving the efficiency and accuracy of transferring the LED and further reducing the manufacturing process difficulty of Micro LED.

[0050] Please refer to Figure 1 , a preferred embodiment of this application provides an LED transfer device 100. The LED transfer device 100 includes a photothermal conversion layer 20, an adsorption layer 30 and a light source 10. The light source 10 is located on one side of the photothermal conversion layer 20, and the adsorption layer 30 is formed on a surface of the photothermal conversion layer 20 away from the light source 10.

[0051] Among them, the light source 10 is used to generate polarized light. The number of the light sources 10 can be one, or two or more.

[0052] Among them, the photothermal conversion layer 20 can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of the polarized light.

[0053] In this embodiment, the material of the photothermal conversion layer 20 is a multi-directionally controllable soft composite material driven by polarized light.

[0054] Among them, the photothermal conversion layer 20 includes a polydimethylsiloxane film layer 21, a polyimide (PI) film layer 22 and a polyacrylamide film layer 23. The polyacrylamide film layer 23 is located between the polydimethylsiloxane film layer 21 and the polyimide film layer 22, and the polyimide film layer 22 faces the adsorption layer 30.

[0055] Among them, the structural formula of polydimethylsiloxane (PDMS) is:

[0056]

[0057] Among them, the structural formula of polyacrylamide (PAM) is:

[0058]

[0059] Among them, the polyacrylamide film layer 23 includes the polyacrylamide polymer and first nanorods dispersed in the polyacrylamide polymer, and the material of the first nanorods is an Au-polyvinylpyrrolidone-phenolic resin condensate modified Fe3O4-SiO2 coating composite.

[0060] Among them, the first nanorods are aligned in a specific direction between the polydimethylsiloxane film layer 21 and the polyimide film layer 22.

[0061] Among them, the working mechanism of the photothermal conversion layer 20 is based on the different thermal expansions of polymers. The photothermal conversion layer 20 includes the polydimethylsiloxane film layer 21, the polyimide film layer 22, and the polyacrylamide film layer 23 located between the polydimethylsiloxane film layer 21 and the polyimide film layer 22. The coefficients of thermal expansion (CTEs) of PDMS and PI are a = 310×10 -6 K -1 and 20×10 -6 K -1 . Therefore, under the same temperature increase, the volume expansion of the polydimethylsiloxane film layer 21 (PDMS film layer) is much higher than that of the polyimide film layer 22 (PI film layer). The polydimethylsiloxane film layer 21, the polyimide film layer 22, and the polyacrylamide film layer 23 (PAM film layer) are driven in the following order: 1) Under laser irradiation (wavelength 450 nm), the nanorods (first nanorods) in the middle polyacrylamide film layer 23 (PAM film layer) act as photothermal conversion materials, converting light energy into heat energy and causing a sharp local temperature increase; 2) The heat is simultaneously transferred to the upper layer of the polyimide film layer 22 (PI film layer) and the lower layer of the polydimethylsiloxane film layer 21 (PDMS film layer); 3) Due to the larger volume expansion of PDMS, the entire photothermal conversion layer 20 bends toward the polyimide film layer 22 (PI film layer) side and deforms.

[0062] Specifically, in this embodiment, the preparation method of the polarization-driven multi-directionally controllable soft composite material includes:

[0063] Step 1: Preparation of Fe3O4-SiO2 coated composite nanorods (second nanorod A): Dissolve 10.8 g of solid FeCl3·6H2O in 400 mL of deionized water (DI water). Heat the solution in an oven to 87 °C and maintain this temperature for 18 hours. Subsequently, remove the supernatant, and wash the obtained FeOOH nanorod precipitate 3 - 4 times at 11000 rpm in a washing machine with deionized water for 15 - 20 minutes. Disperse the obtained product in 40 mL of deionized water. Then, modify FeOOH with PAA (Polyamic acid). Dissolve 216 mg of PAA (WM = 1800) in 600 mL of deionized water, and then dropwise add the above 10 mL of FeOOH aqueous dispersion into it. Stir the obtained solution magnetically overnight. Collect the obtained PAA-modified FeOOH by centrifugation and wash it 3 times with deionized water (wash 3 - 4 times at 11000 rpm for 15 - 20 minutes). Disperse the above PAA-modified FeOOH in 12 mL of deionized water. Subsequently, concentrate the above obtained 4 mL of FeOOH dispersion to 2 mL and add it to 40 ml of absolute ethanol, and then add 250 μL of NH3·H2O solution (volume percentage is 28%) to it. Generally, for the final formation of a 5 nm SiO2 coating, add 200 μL of TEOS (Tetraethyl orthosilicate), or for the final formation of a 10 nm SiO2 coating, add 250 μL of TEOS 3 times every hour. React the obtained modified FeOOH-SiO2 coated composite for 10 minutes at 14500 rpm and precipitate it. Wash it 1 - 2 times with ethanol and 3 - 4 times with water. Heat 15 mL of diethylene glycol to 220 °C under a nitrogen gas flow protection, and then inject 250 μL of the aqueous solution of the modified FeOOH-SiO2 coated composite into the above hot diethylene glycol solution. This reduction process lasts for 5 - 6 hours under nitrogen gas protection. Wash the finally obtained Fe3O4-SiO2 coated composite nanorods 3 - 4 times with ethanol and water, and then disperse them in 12 mL of absolute ethanol for standby.

[0064] Step 2: Preparation of Au-polyvinylpyrrolidone modified Fe3O4-SiO2 coated composite nanorods (the third nanorod B). Add the solution of Fe3O4-SiO2 composite nanorods (the second nanorod A) dispersed in 12 ml of absolute ethanol into 50 mL of ethanol, then heat to 78 °C and keep for 10 min, and then add 200 μL of 3-aminopropyl-triethoxysilane. This surface modification process needs to be continuously carried out for 5 hours under nitrogen protection. Wash the obtained product with ethanol 3 - 4 times and then disperse it in 12 mL of ethanol for standby. Add 12 μL of tetrakis(hydroxymethyl)phosphonium chloride and 250 μL of NaOH (2 mol / L) to 45 mL of Milli-Q water (commercially available ultrapure water). After 5 minutes, add 2 mL of HAuCl4 (mass fraction 1%). Cover the reactor with tin foil and stir overnight. Then, store this HAuCl4 solution in an environment at 4 °C for standby. Centrifuge the solution of Fe3O4-SiO2 composite nanorods (the second nanorod A) in 3 ml of the standby ethanol and wash it with deionized water 2 - 3 times. Disperse it in 5 mL of deionized water and add it to 2 mL of the above-mentioned HAuCl4 solution stored at 4 °C. Stir the mixture for 1 - 2 hours. As a result, Au seeds are attached to the surface of Fe3O4-SiO2 composite nanorods through electrostatic interaction. Finally, centrifuge at 14500 rpm for 10 minutes to remove the excess Au seeds. Then, add 5 mL of deionized water to disperse the obtained Au seed-modified Fe3O4-SiO2 composite nanorods (the third nanorod B). Transfer the above dispersion to 10 mL of polyvinylpyrrolidone solution (20 mg / mL, MW = 10000) under ultrasonic treatment. Stir the mixture overnight at room temperature. Remove the excess polyvinylpyrrolidone by centrifuging at 14500 rpm for 10 minutes. Wash the obtained product with deionized water 2 - 3 times and disperse it in 28 mL of deionized water for standby.

[0065] Step 3: Preparation of Au-polyvinylpyrrolidone-phenol formaldehyde condensate modified Fe3O4-SiO2 coated composite nanorods (the first nanorod C). Add 13 mg of resorcinol and 18 μL of formaldehyde to the above-mentioned standby dispersion in sequence. Then, heat the mixture to 50 °C, and then add 100 μL of NH3·H2O solution (2.8%). Keep the reaction at 50 °C for 2 hours, and then raise the reaction temperature to 100 °C for the phenol formaldehyde condensation reaction. Moreover, under alkaline conditions, the SiO2 coating is etched, forming a certain gap between the Fe3O4 nanorods and the phenol formaldehyde condensate. After reacting for 5 - 6 hours, wash the final product with Milli-Q water (ultrapure water) 3 - 4 times and disperse it in 2 mL of Milli-Q water (ultrapure water) for standby.

[0066] Step 4: Preparation of PDMS (polydimethylsiloxane) and PAM (polyacrylamide) thin layers. The PDMS (polydimethylsiloxane) silicone elastomer curing agent and the silicone elastomer base material are fully mixed at a mass ratio of 1:10. The mixture is cured at 60 °C for 2 hours to form a cross-linked PDMS thin layer for standby. Separately, the Au-polyvinylpyrrolidone-phenol-formaldehyde condensate modified Fe3O4-SiO2 coated composite nanorods (first nanorod C) obtained in the above steps are dispersed in a solution of the precursor of PAM (acrylamide, 250 mg), which contains 1 ml of water as a solvent, 2-hydroxy-2-methylpropiophenone (6 μL) as a photoinitiator, and N,N'-methylenebisacrylamide (28 mg) as a cross-linking agent. After the (first nanorod C) is completely dispersed in the above solution, the mixture is added to the gap between the PDMS and the PI tape (commercially available). Ultraviolet light is irradiated from the transparent PDMS side for about 2 minutes to cure the polymer. At the same time, a magnetic field is applied to align the first nanorod C in a specific direction. Herein, the polymer refers to the polymerized PAM.

[0067] It should be noted that the dosages of various components, reaction time, curing time, etc. involved in the preparation method of the polarized light-driven multi-directionally controllable soft composite material are not limited to the specific dosages, specific reaction time, and specific fixing time in the above steps (1), (2), (3), and (4), and can be adjusted according to the actual situation.

[0068] Herein, the adsorption layer 30 is elastic and can be switched between an adhesion state and a de-adhesion state. When the adsorption layer 30 is in a magnetic field-free environment, the adsorption layer is in an adhesion state, and the adsorption layer in the adhesion state has adhesiveness; and when the adsorption layer 30 is in a magnetic field environment, the adsorption layer 30 is in a de-adhesion state, and the adsorption layer in the de-adhesion state does not have adhesiveness.

[0069] Herein, the material of the adsorption layer 30 is a magnetically controlled adhesion-de-adhesion organic-inorganic composite material, and the magnetically controlled adhesion-de-adhesion organic-inorganic composite material includes polyurethane and iron oxide particles, and the iron oxide particles are mixed with the polyurethane. In the adsorption layer, the percentage of the iron oxide particles is 1% - 20%, and the rest is the polyurethane.

[0070] Herein, the structural formula of the polyurethane is:

[0071] Herein, m, n, and q are all positive integers.

[0072] In an optional embodiment of the present application, the polyurethane is synthesized from three components of hydroxyl-terminated polyolefin glycol, diphenylmethane diisocyanate, and 4-(2-aminoethyl)morpholine (as shown in the following figure).

[0073]

[0074] Wherein, the structural formula of the hydroxylated polyolefin diol is: The structural formula of the diphenylmethane diisocyanate is: The structural formula of the 4-(2-aminoethyl)morpholine is:

[0075] There are multiple hydrogen bonds between the polyurethanes, such as hydrogen bonds between adjacent polyurethane molecules: and

[0076] Of course, the polyurethane is not limited to the above preparation method and can be determined according to actual conditions.

[0077] Among them, the multiple hydrogen bonds between the polyurethane molecules interact with each other, so that the magnetically controlled adhesion-deadhesion organic-inorganic composite material itself has good adhesion. In particular, when the magnetically controlled adhesion-deadhesion organic-inorganic composite material is placed in an oscillating magnetic field, the ferroferric oxide particles therein will couple with the magnetic field to produce a hysteresis thermal effect, so that the temperature of the magnetically controlled adhesion-deadhesion organic-inorganic composite material increases, further weakening the hydrogen bonds between the polyurethane molecules, thereby causing the magnetically controlled adhesion-deadhesion organic-inorganic composite material to debond from the adhered surface.

[0078] In an optional embodiment of the present application, the LED transfer device 100 further includes a plurality of spacers 40, which are sequentially fixed on the side of the light-to-heat conversion layer 20 away from the adsorption layer 30. The plurality of spacers 40 are opaque, and a cavity 50 is formed between two adjacent spacers 40; the light source 10 faces the cavity 50. Under the irradiation of the polarized light generated by the light source 10, the light-to-heat conversion layer 20 corresponding to the cavity 50 is partially deformed. Under the action of the magnetic field, the portion of the adsorption layer 30 facing the cavity 50 is synchronously deformed and changes from an adhered state to a de-adhesive state.

[0079] In an optional embodiment of the present application, one light source 10 corresponds to at least one cavity 50, and only the light-to-heat conversion layer 20 in the cavity 50 irradiated with polarized light is deformed, while the light-to-heat conversion layer 20 not irradiated with polarized light does not deform.

[0080] Wherein, the LED transfer device 100 further includes at least one transparent elastomer 60, and the transparent elastomer 60 covers one end of the cavity 50 and is fixed to one end of the spacer 40 away from the photothermal conversion layer 20. The transparent elastomer 60 is used to protect the spacer 40 and the photothermal conversion layer 20.

[0081] In an alternative embodiment of the present application, the number of the transparent elastomers 60 is plural, and the plural transparent elastomers 60 are sequentially received in the plural cavities 50; each transparent elastomer 60 is fixed to one end of two spacers 40 away from the photothermal conversion layer 20.

[0082] In another alternative embodiment of the present application, the number of the transparent elastomers 60 is one, and one transparent elastomer 60 is directly formed on one end of the plural spacers 40 away from the photothermal conversion layer 20. That is, the transparent elastomer 60 covers the cavity 50 and the spacer 40.

[0083] In an alternative embodiment of the present application, the LED transfer device 100 further includes a magnetic field generator (not shown in the figure). The magnetic field generator is used to generate a magnetic field so that the adsorption layer can be switched between an adhesion state and a de-adhesion state.

[0084] In an alternative embodiment of the present application, the model of the magnetic field generator is RFP-7500-0.4, which has a maximum rated power of 7.5 kW, an operating frequency of 308 kHz, a maximum alternating current of 800 A, a short solenoid induction coil length L = 2.9 cm, a distance d between adjacent turns of the coil = 3.5 cm, and the number of turns = 3. The magnetic field intensity generated by the magnetic field generator is 5000-10000 A.m -1 。

[0085] Please refer to Figures 2 to 8 , the present application further provides a method for transferring an LED, and the method for transferring the LED is implemented by the LED transfer device 100.

[0086] The method for transferring the LED includes:

[0087] Step S1, please refer to Figure 2 and Figure 3 , move the LED transfer device 100 in the initial state to directly above the target LED 200.

[0088] Wherein, the plural target LEDs 200 are divided into several groups and are arranged in an array on an LED carrier 201.

[0089] Among them, the LED transfer device 100 can be moved to directly above the target LED 200 by means of a robotic arm or the like. Further, the LED transfer device 100 can also be accurately moved to directly above the target LED 200 with the help of a charge-coupled device (CCD) or the like.

[0090] Step S2, please refer to Figure 2 and Figure 4 , and continue to move the LED transfer device 100 so that the adsorption layer 30 in the adhesion state contacts the target LED 200, so that the adsorption layer 30 adheres to the target LED 200.

[0091] Among them, one cavity 50 corresponds to a group of the target LEDs 200. That is, the number of the cavities 50 is the same as the number of groups of the target LEDs 200 that can be transferred at one time, and each group of the target LEDs includes at least one of the target LEDs.

[0092] Step S3, please refer to Figure 2 and Figure 5 , transfer the target LED 200 above a receptor substrate 300, and control the light source 10 to emit polarized light; the photo-thermal conversion layer 20 corresponding to at least one of the cavities 50 deforms under the irradiation of the polarized light.

[0093] Among them, the deformed photo-thermal conversion layer 20 is closer to the receptor substrate than the undeformed photo-thermal conversion layer 20.

[0094] Step S4, please refer to Figure 2 and Figure 6 , place the target LED 200 that needs to be de-adhered in a magnetic field, and the deformed adsorption layer 30 changes from the adhesion state to the de-adhesion state under the action of the magnetic field, and the target LED 200 located at the deformed adsorption layer 30 is completely de-adhered.

[0095] Step S5, please refer to Figure 2 , Figure 7 and Figure 8 , move the LED transfer device 100 away from the receptor substrate 300; at the same time, the deformed photo-thermal conversion layer 20 and the adsorption layer 30 recover from the deformation, and the adsorption layer 30 changes from the de-adhesion state to the adhesion state.

[0096] The LED transfer device and LED transfer method provided by this application are as follows: 1) The LED transfer device includes a photothermal conversion layer and an adsorption layer. The photothermal conversion layer can deform under the irradiation of polarized light and recover the deformation after stopping the irradiation of the polarized light. By regulating the magnetic field, the adsorption layer can be switched between the adhesion state and the de-adhesion state, so that the LED transfer device can adhere to multiple target LEDs in the non-magnetic field state and can be de-adhered from multiple LEDs simultaneously in the magnetic field state, thereby improving the efficiency and accuracy of transferring LEDs. Therefore, the LED transfer device provided by this application can break through the mass transfer technology and reduce the manufacturing process difficulty of Micro LEDs, realizing mass production and large-scale production. 2) A polyacrylamide film layer is prepared by using an Fe3O4-SiO2 coating composite modified with Au-polyvinylpyrrolidone-phenol formaldehyde condensate and a polyacrylamide polymer, and then a polarization-driven multi-directionally controllable soft composite material is prepared by using the polyacrylamide film layer, a polydimethylsiloxane film layer and a polyimide film layer to obtain the photothermal conversion layer. The photothermal effect of the light-absorbing material of the polarization-driven multi-directionally controllable soft composite material can convert light energy into mechanical deformation, which has the advantages of precision, remote control and rapidity compared with other driving methods. 3) A magnetically controlled adhesion-deadhesion organic-inorganic composite material is prepared by using polyurethane and iron oxide particles. Due to the existence of various hydrogen bond interactions in the polyurethane, the organic-inorganic composite material itself has good adhesion. In particular, when the organic-inorganic composite material is placed in an oscillating magnetic field, the iron oxide particles in it will be coupled with the magnetic field to generate a hysteresis thermal effect, causing the temperature of the organic-inorganic composite material to rise, further weakening the hydrogen bonds between polyurethane molecules, thereby realizing the de-adhesion of the organic-inorganic composite material from the adhered surface.

[0097] The LED transfer device and LED transfer method provided by the embodiments of this application have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the technical solution and its core idea of this application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An LED transfer device, characterized in that, Comprising: A photothermal conversion layer capable of deforming under the irradiation of polarized light and restoring the deformation after the irradiation of the polarized light is stopped; A light source located on one side of the photothermal conversion layer and used to generate polarized light; and An adsorption layer formed on a surface of the photothermal conversion layer away from the light source; the adsorption layer has elasticity and can switch between an adhesion state and a de-adhesion state; wherein, When the adsorption layer is in a magnetic field-free environment, the adsorption layer is in an adhesion state, and the adsorption layer in the adhesion state has adhesiveness; and When the adsorption layer is in a magnetic field environment, the adsorption layer is in a de-adhesion state, and the adsorption layer in the de-adhesion state does not have adhesiveness.

2. The LED transfer device according to claim 1, characterized in that The material of the photothermal conversion layer is a polarization-driven multi-directional controllable soft composite material; the photothermal conversion layer includes: A polydimethylsiloxane film layer; A polyimide film layer; and A polyacrylamide film layer located between the polydimethylsiloxane film layer and the polyimide film layer; the polyimide film layer faces the adsorption layer; Wherein, the polyacrylamide film layer includes a polyacrylamide polymer and first nanorods dispersed in the polyacrylamide polymer, and the material of the first nanorods is an Au-polyvinylpyrrolidone-phenolic resin condensate-modified Fe3O4-SiO2 coating composite.

3. The LED transfer device according to claim 1, wherein The material of the adsorption layer is a magnetically controlled adhesion-de-adhesion organic-inorganic composite material, and the magnetically controlled adhesion-de-adhesion organic-inorganic composite material includes polyurethane and iron oxide particles, the iron oxide particles are mixed with the polyurethane, and there are multiple hydrogen bonds between the polyurethanes.

4. The LED transfer device according to claim 3, characterized in that, In the adsorption layer, the percentage of the iron oxide particles is 1%-20%, and the rest is the polyurethane.

5. The LED transfer device according to claim 1, wherein The LED transfer device further includes: A plurality of spacer portions sequentially fixed on a side of the photothermal conversion layer away from the adsorption layer; wherein, The plurality of spacer portions are light-impermeable, and a cavity is formed between two adjacent spacer portions; the light source is opposite to the cavity; and Under the irradiation of the polarized light generated by the light source, the photothermal conversion layer corresponding to the cavity deforms; under the action of a magnetic field, a part of the adsorption layer opposite to the cavity deforms synchronously and changes from an adhesion state to a de-adhesion state.

6. The LED transfer device according to claim 5, wherein The light source is located inside or outside the cavity.

7. The LED transfer device according to claim 5, characterized in that, The LED transfer device further includes: A plurality of transparent elastomers sequentially received in the plurality of cavities; each transparent elastomer is fixed at one end of two spacer portions away from the photothermal conversion layer.

8. A transfer method of an LED, characterized in that, The LED transfer method is implemented by an LED transfer device, wherein the LED transfer device includes: a light source, a photothermal conversion layer, an adsorption layer and spacer portions; the light source is located on one side of the photothermal conversion layer, the adsorption layer is formed on a surface of the photothermal conversion layer away from the light source, the plurality of spacer portions are light-impermeable and are sequentially fixed on a side of the photothermal conversion layer away from the adsorption layer, and a cavity is formed between two adjacent spacer portions, and the light source is opposite to the cavity; wherein, the LED transfer method includes: Move the LED transfer device in the initial state to directly above the target LED; Continue to move the LED transfer device so that the adsorption layer in the adhesion state contacts the target LED, and the adsorption layer adheres to the target LED; wherein, one cavity corresponds to one target LED; Transfer the target LED above a receptor substrate, and control the light source to emit polarized light, and the photothermal conversion layer corresponding to at least one cavity deforms under the irradiation of the polarized light; Place the target LED that needs to be de-adhered in a magnetic field, and the deformed adsorption layer changes from the adhesion state to the de-adhesion state under the action of the magnetic field, and the target LED located at the deformed adsorption layer is completely de-adhered; and Move the LED transfer device away from the receptor substrate; at the same time, the deformed photothermal conversion layer and the adsorption layer recover their deformation, and the adsorption layer changes from the de-adhesion state to the adhesion state.

9. The transfer method of the LED according to claim 8, characterized in that, The material of the photothermal conversion layer is a multi-directionally controllable soft composite material driven by polarized light; the photothermal conversion layer includes: A polydimethylsiloxane film layer; A polyimide film layer; and A polyacrylamide film layer located between the polydimethylsiloxane film layer and the polyimide film layer; the polyimide film layer faces the adsorption layer; Wherein, the polyacrylamide film layer includes a polyacrylamide polymer and first nanorods dispersed in the polyacrylamide polymer, and the material of the first nanorods is an Au-polyvinylpyrrolidone-phenolic resin-modified Fe3O4-SiO2 coating composite.

10. The transfer method of the LED according to claim 8, characterized in that, The material of the adsorption layer is a magnetically controlled adhesion-deadhesion organic-inorganic composite material. The adsorption layer includes polyurethane and iron tetroxide particles. The iron tetroxide particles are mixed with the polyurethane, and there are various hydrogen bonds between the polyurethanes; in the adsorption layer, the percentage of the iron tetroxide particles is 1%-20%, and the rest is the polyurethane.

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