Micro-LED chip mass transfer device and method based on amorphous soft magnetic strip material

Abstract

The invention discloses a Micro-LED chip mass transfer device and method based on an amorphous soft magnetic strip material, and aims to reduce the difficulty of mass transfer of Micro-LED chips and effectively improve the stability of mass transfer of Micro-LED chips. The mass transfer device comprises a magnetic transfer substrate, an electromagnet device and an adjusting platform located below the magnetic transfer substrate. A plurality of Micro-LED chips to be transferred and arranged on the blue film are placed on the surface, facing the magnetic transfer substrate, of the adjusting platform, and magnetic layers are arranged on the surfaces, away from the blue film, of the Micro-LED chips; the magnetic transfer substrate comprises a substrate and an amorphous soft magnetic strip material, the amorphous soft magnetic strip material is provided with a plurality of open holes, the plurality of open holes are in one-to-one correspondence with the plurality of Micro-LED chips in position, and the amorphous soft magnetic strip material is fixed on the surface, facing the adjusting platform, of the substrate; and the electromagnet device is connected with the amorphous soft magnetic strip material to form a closed loop, so that the Micro-LED chip is transferred to the substrate from the blue film by the amorphous soft magnetic strip material.

Description

Technical Field

[0001] The present invention relates to the technical field of Micro-LED chip mass transfer, and in particular to a Micro-LED chip mass transfer device and method based on amorphous soft magnetic tape. Background Art

[0002] Micro-LED, as an actively luminous micron-scale luminous pixel unit, is regarded as the most promising display technology in the next generation display field. This display technology has clearer shadows, more detailed expressions, and higher color depth, and has great potential in commercial fields such as conferences and exhibitions, office displays, and virtual reality.

[0003] In the process technology link, mini-LED and Micro-LED are mainly transferred and packaged using mass transfer technology. In order to achieve full-color Micro-LED displays, transfer technologies can be divided into two categories: the first is the selective batch transfer of RGB Micro-LED chips. After the Micro-LED chips of different colors are separated from their growth substrates, the RGB Micro-LED chips are picked up from different growth substrates using a transfer medium, and then the RGB Micro-LED chips are placed on the target substrate; the second is the selective batch transfer of monochrome Blue / UV Micro-LED chips, followed by integrated color conversion, such as inkjet printing of quantum dots (QD) or light-emitting polymers. The entire blue light Micro-LED chip can be directly transferred in a single piece immediately after the epitaxial peeling process without changing the original distance between adjacent Micro-LED chips. However, color conversion technology still has technical problems such as heat dissipation difficulties, low color conversion efficiency, and thermal stability.

[0004] At present, the commonly used technical solution is mainly the selective batch transfer of RGB Micro-LED chips, that is, the pick-and-place process uses physical adhesion (such as van der Waals force, fluid tension, electrostatic force, magnetic force, laser transfer). In the pick-up step, the adhesion strength of the transmission medium / Micro-LED chip interface must be stronger than the adhesion strength of the Micro-LED chip / donor, so that the Micro-LED chip can be successfully peeled off from the donor substrate. In the placement / adsorption step, low interface adhesion strength is conducive to transferring the Micro-LED chip to the receiving substrate. Micro-LED chips need to be transferred from sapphire substrate → temporary substrate → new substrate multiple times, and the amount of chips transferred each time is very large, which requires very high stability and accuracy of the transfer process. For R / G / B full-color display, since each process can only produce chips of one color, the red / green / blue chips need to be transferred separately, and a very precise process is required to position the chips, which greatly increases the difficulty of the transfer process. The thickness of the Micro-LED chip is only a few microns, and it is very difficult to place it accurately on the target substrate. The size and spacing of the Micro-LED chip are very small, and it is also a challenge to connect the Micro-LED chip to the circuit. It is a key step towards mass production of Micro-LED chips, but there are still many problems.

[0005] Therefore, finding a technical solution that can solve the above technical problems has become an important topic studied by technical personnel in this field. Summary of the invention

[0006] The embodiment of the present invention discloses a device and method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape to solve the above technical problems.

[0007] The present invention provides a Micro-LED chip mass transfer device based on amorphous soft magnetic tape, comprising a magnetic transfer substrate, an electromagnet device and an adjustment platform located below the magnetic transfer substrate;

[0008] A plurality of Micro-LED chips to be transferred and arranged on a blue film are placed on the surface of the adjustment platform facing the magnetic transfer substrate, wherein a magnetic layer is arranged on the surface of the Micro-LED chip away from the blue film;

[0009] The magnetic transfer substrate comprises a substrate and an amorphous soft magnetic tape material, the amorphous soft magnetic tape material is provided with a plurality of openings, the plurality of openings correspond to the positions of the plurality of Micro-LED chips one by one, and the amorphous soft magnetic tape material is fixed on the surface of the substrate facing the adjustment platform;

[0010] The electromagnet device is connected to the amorphous soft magnetic tape to form a closed loop so that the amorphous soft magnetic tape can transfer the Micro-LED chip from the blue film to the substrate.

[0011] Optionally, the electromagnet device includes a soft magnetic body and an energized coil;

[0012] The energized coil is wound around the soft magnetic body, the soft magnetic body has a first magnetic pole and a second magnetic pole, and the opposite ends of the amorphous soft magnetic tape are respectively connected to the first magnetic pole and the second magnetic pole.

[0013] Optionally, a plurality of the openings are arranged in a matrix on the amorphous soft magnetic tape.

[0014] Optionally, the adjustment platform includes an X-axis linear module, a Y-axis linear module, a Z-axis linear module, and a plurality of Micro-LED chips to be transferred and disposed on the blue film;

[0015] The Y-axis linear module is connected to the Z-axis linear module, and the Z-axis linear module is used to drive the Y-axis linear module to move along the Z-axis direction. The X-axis linear module is connected to the Y-axis linear module, and the Y-axis linear module is used to drive the X-axis linear module to move along the Y-axis direction. The support plate is connected to the X-axis linear module, and the X-axis linear module is used to drive the support plate to move along the X-axis direction.

[0016] Optionally, the adjustment platform further includes a rotating module, the rotating module is connected to the X-axis linear module, the support plate is connected to the rotating module, and the rotating module is used to drive the support plate to rotate around its own axis.

[0017] Optionally, the substrate is transparent glass.

[0018] Optionally, the amorphous soft magnetic tape is made of an iron-based amorphous soft magnetic alloy Metglas.

[0019] The present invention provides a method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape. The method is based on the above-mentioned device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape, and the method comprises the following steps:

[0020] S1. Prepare a Micro-LED chip, and invert the prepared Micro-LED chip onto a blue film, and then place the blue film and the Micro-LED chip on an adjustment platform;

[0021] S2. Adjust the positions of the Micro-LED chips by adjusting the platform so that the positions of the multiple Micro-LED chips correspond to the positions of the multiple openings on the amorphous soft magnetic tape material one by one;

[0022] S3. Turn on the electromagnet device and control the magnetization intensity in the amorphous soft magnetic tape material and the stray magnetic field at the opening through the energized coil of the electromagnet device, thereby controlling the adsorption force on the Micro-LED chip, and then transferring the Micro-LED chip from the blue film to the substrate. Then reduce the current of the energized coil to reduce the magnetic field, and complete the mass transfer of Micro-LED chips.

[0023] Optionally, the preparation of the Micro-LED chip in step S1 specifically includes:

[0024] Prepare sapphire-based blue light epitaxial wafers, and complete the preparation of Micro-LED chips according to the size of Micro-LED chips to form wafers;

[0025] After the wafer is thinned and polished to a preset thickness, a magnetic material is deposited on the back side of the wafer to a preset thickness to form a magnetic layer;

[0026] The wafer is diced and inverted onto a blue film, and a plurality of Micro-LED chips with a magnetic layer facing upward are formed on the blue film.

[0027] Optionally, the magnetic material includes one of cobalt, iron and its alloys, nickel and its alloys, rare earth and its alloys, and manganese compounds.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In the mass transfer device of Micro-LED chips based on amorphous soft magnetic tape material of this embodiment, the magnetization intensity in the amorphous soft magnetic tape material and the stray magnetic field at the opening are controlled by controlling the current in the electromagnet device, thereby controlling the adsorption force on the Micro-LED chip, and then transferring the Micro-LED chip on the blue film to the substrate through the opening. In the above design, a large stray magnetic field gradient can be generated at the opening of the amorphous soft magnetic tape material, which has high magnetic permeability and high saturation magnetization, and can generate a large adsorption force on the Micro-LED chip, thereby effectively reducing the difficulty of mass transfer of Micro-LED chips and effectively improving the stability of mass transfer of Micro-LED chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of a Micro-LED chip mass transfer device based on amorphous soft magnetic tape provided by an embodiment of the present invention (the electromagnet device is not shown);

[0032] Figure 2 A top view of an amorphous soft magnetic tape material of a Micro-LED chip mass transfer device based on an amorphous soft magnetic tape material provided in an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the structure of an electromagnet device of a Micro-LED chip mass transfer device based on an amorphous soft magnetic tape provided by an embodiment of the present invention when connected to an amorphous soft magnetic tape;

[0034] Figure 4 A schematic diagram of the magnetic field line distribution at the opening of an amorphous soft magnetic tape material in a Micro-LED chip mass transfer device based on an amorphous soft magnetic tape material and the adsorption force on a Micro-LED chip including a magnetic layer provided in an embodiment of the present invention;

[0035] Figure 5 A flow chart of a method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape provided by an embodiment of the present invention;

[0036] Illustration: adjustment platform 1; substrate 2; amorphous soft magnetic tape material 3; opening 4; soft magnetic body 5; energized coil 6; first magnetic pole 7; second magnetic pole 8; blue film A; Micro-LED chip B. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] See also Figures 1 to 4, a device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape provided by an embodiment of the present invention comprises a magnetic transfer substrate, an electromagnet device and an adjustment platform 1 located below the magnetic transfer substrate;

[0039] A plurality of Micro-LED chips to be transferred and arranged on a blue film are placed on the surface of the adjustment platform 1 facing the magnetic transfer substrate, wherein a magnetic layer is arranged on the surface of the Micro-LED chip away from the blue film;

[0040] The magnetic transfer substrate includes a substrate 2 and an amorphous soft magnetic tape material 3, wherein a plurality of openings 4 are formed on the amorphous soft magnetic tape material 3, wherein the plurality of openings 4 correspond to the positions of the plurality of Micro-LED chips one by one, and the amorphous soft magnetic tape material 3 is fixed on the surface of the substrate 2 facing the adjustment platform 1;

[0041] The electromagnet device is connected to the amorphous soft magnetic tape 3 and forms a closed loop so that the amorphous soft magnetic tape 3 transfers the Micro-LED chip from the blue film to the substrate 2 .

[0042] It should be noted that, in this embodiment, the amorphous soft magnetic tape material 3 is solidified evenly on the substrate 2 by UV glue, and then the amorphous soft magnetic tape material 3 is opened with holes 4 by a femtosecond laser, and the period of the openings 4 is consistent with the period of the chip.

[0043] In the device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape of this embodiment, the magnetization intensity in the amorphous soft magnetic tape 3 and the stray magnetic field at the opening 4 are controlled by controlling the current in the electromagnet device, thereby controlling the adsorption force on the Micro-LED chip, and then transferring the Micro-LED chip on the blue film to the substrate 2 through the opening 4. In the above design, a large stray magnetic field gradient can be generated at the opening 4 of the amorphous soft magnetic tape 3, which has high magnetic permeability and high saturation magnetization, and can generate a large adsorption force on the Micro-LED chip, thereby effectively reducing the difficulty of mass transfer of Micro-LED chips and effectively improving the stability of mass transfer of Micro-LED chips.

[0044] Furthermore, the electromagnet device in this embodiment specifically includes a soft magnetic body 5 and an energized coil 6;

[0045] The energized coil 6 is wound around the soft magnetic body 5 , and the soft magnetic body 5 has a first magnetic pole 7 and a second magnetic pole 8 . The opposite ends of the amorphous soft magnetic tape 3 are connected to the first magnetic pole 7 and the second magnetic pole 8 , respectively.

[0046] It should be noted that the soft magnetic body 5 in this embodiment is specifically a U-shaped structure, which has a first magnetic pole 7 and a second magnetic pole 8. In the actual transfer process, the opposite ends of the amorphous soft magnetic tape material 3 are respectively connected to the first magnetic pole 7 and the second magnetic pole 8, so that after the electromagnet device is energized, the amorphous soft magnetic tape material 3 can be magnetized, thereby achieving adsorption of the Micro-LED chip.

[0047] Furthermore, the openings 4 in this embodiment are arranged in a matrix on the amorphous soft magnetic tape material 3 .

[0048] It should be noted that the arrangement of the above-mentioned openings 4 needs to be consistent with the arrangement of the Micro-LED chips. Through the above-mentioned design, it is ensured that the Micro-LED chips can be accurately fixed on the substrate 2 through the openings 4 after being adsorbed.

[0049] Furthermore, the adjustment platform 1 in this embodiment includes an X-axis linear module, a Y-axis linear module, a Z-axis linear module, and a plurality of Micro-LED chips to be transferred and disposed on a blue film;

[0050] The Y-axis linear module is connected to the Z-axis linear module, and the Z-axis linear module is used to drive the Y-axis linear module to move along the Z-axis direction. The X-axis linear module is connected to the Y-axis linear module, and the Y-axis linear module is used to drive the X-axis linear module to move along the Y-axis direction. The support plate is connected to the X-axis linear module, and the X-axis linear module is used to drive the support plate to move along the X-axis direction.

[0051] It should be noted that, through the above design, the support plate can be moved in the XYZ three-axis directions so that the position of the Micro-LED chip corresponds to the position of the opening 4.

[0052] In addition, the adjustment platform 1 in this embodiment further includes a rotating module, the rotating module is connected to the X-axis linear module, the support plate is connected to the rotating module, and the rotating module is used to drive the support plate to rotate around its own axis.

[0053] It should be noted that, through the above design, the support plate can be rotated on the basis of moving in the three-axis directions of XYZ, so as to adjust the rotation angle of the Micro-LED chip, thereby ensuring that the Micro-LED chip is accurately aligned with the opening 4.

[0054] Furthermore, the substrate 2 in this embodiment is specifically a transparent substrate 2, and is preferably made of transparent glass.

[0055] Furthermore, the amorphous soft magnetic tape 3 in this embodiment is made of an iron-based amorphous soft magnetic alloy Metglas.

[0056] See also Figures 1 to 5 The embodiment of the present invention provides a method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape. The method is based on the above-mentioned device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape, and the method includes the following steps:

[0057] S1, preparing a Micro-LED chip, and inverting the prepared Micro-LED chip onto a blue film, and then placing the blue film and the Micro-LED chip on an adjustment platform 1;

[0058] S2, adjusting the positions of the Micro-LED chips by adjusting the platform 1, so that the positions of the plurality of Micro-LED chips correspond to the positions of the plurality of openings 4 on the amorphous soft magnetic tape material 3 one by one;

[0059] S3, turn on the electromagnet device, and control the magnetization intensity in the amorphous soft magnetic tape material 3 and the stray magnetic field at the opening 4 through the energized coil 6 of the electromagnet device, so as to control the adsorption force on the Micro-LED chip, and then transfer the Micro-LED chip from the blue film to the substrate 2, and then reduce the current of the energized coil 6 to reduce the magnetic field, and complete the mass transfer of the Micro-LED chips.

[0060] In the method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape material of this embodiment, the magnetization intensity in the amorphous soft magnetic tape material 3 and the stray magnetic field at the opening 4 are controlled by controlling the current of the energized coil 6 in the electromagnet device, thereby controlling the adsorption force on the Micro-LED chip, and then transferring the Micro-LED chip on the blue film to the substrate 2 through the opening 4. In the above design, a large stray magnetic field gradient can be generated at the opening 4 of the amorphous soft magnetic tape material 3, which has high magnetic permeability and high saturation magnetization, and can generate a large adsorption force on the Micro-LED chip, thereby effectively reducing the difficulty of mass transfer of Micro-LED chips and effectively improving the stability of mass transfer of Micro-LED chips.

[0061] Furthermore, the preparation of the Micro-LED chip in step S1 of this embodiment specifically includes:

[0062] Prepare a sapphire-based blue epitaxial wafer, and complete the preparation of the Micro-LED chip according to the size of the Micro-LED chip to form a wafer. Specifically, in this embodiment, a 4-inch blue epitaxial wafer is used, and a chip size of 50 microns * 50 microns is adopted, and the interval between the chips is 20 microns;

[0063] After the wafer is thinned and polished to a preset thickness, a magnetic material is deposited on the back side of the wafer to form a magnetic layer by 300 nanometers. Specifically, the preset thickness is 40 micrometers.

[0064] The wafer is diced and inverted onto a blue film, and a plurality of Micro-LED chips with a magnetic layer facing upward are formed on the blue film.

[0065] Furthermore, the magnetic material in this embodiment includes one of cobalt, iron and its alloys, nickel and its alloys, rare earth and its alloys, and manganese compounds.

[0066] It should be noted that, in this embodiment, the preferred magnetic material is cobalt.

[0067] The above is a detailed introduction to a Micro-LED chip mass transfer device and method based on amorphous soft magnetic tape provided by the present invention. For a person skilled in the art, according to the idea of ​​the embodiment of the present invention, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A Micro-LED chip mass transfer device based on amorphous soft magnetic tape, characterized in that: It comprises a magnetic transfer substrate, an electromagnet device and an adjustment platform (1) located below the magnetic transfer substrate; A plurality of Micro-LED chips to be transferred and arranged on a blue film are placed on the surface of the adjustment platform (1) facing the magnetic transfer substrate, wherein a magnetic layer is arranged on the surface of the Micro-LED chip away from the blue film; The magnetic transfer substrate comprises a substrate (2) and an amorphous soft magnetic tape material (3), a plurality of openings (4) are provided on the amorphous soft magnetic tape material (3), the plurality of openings (4) correspond to positions of the plurality of Micro-LED chips one by one, and the amorphous soft magnetic tape material (3) is fixed on a surface of the substrate (2) facing the adjustment platform (1); The electromagnet device is connected to the amorphous soft magnetic tape material (3) to form a closed loop so that the amorphous soft magnetic tape material (3) transfers the Micro-LED chip from the blue film to the substrate (2).

2. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 1, characterized in that: The electromagnet device comprises a soft magnetic body (5) and an energized coil (6); The energized coil (6) is wound around the soft magnetic body (5), the soft magnetic body (5) has a first magnetic pole (7) and a second magnetic pole (8), and opposite ends of the amorphous soft magnetic tape (3) are respectively connected to the first magnetic pole (7) and the second magnetic pole (8).

3. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 1, characterized in that: The plurality of openings (4) are arranged in a matrix on the amorphous soft magnetic tape material (3).

4. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 1, characterized in that: The adjustment platform (1) comprises an X-axis linear module, a Y-axis linear module, a Z-axis linear module, and a plurality of Micro-LED chips to be transferred and arranged on a blue film for placement; The Y-axis linear module is connected to the Z-axis linear module, and the Z-axis linear module is used to drive the Y-axis linear module to move along the Z-axis direction. The X-axis linear module is connected to the Y-axis linear module, and the Y-axis linear module is used to drive the X-axis linear module to move along the Y-axis direction. The support plate is connected to the X-axis linear module, and the X-axis linear module is used to drive the support plate to move along the X-axis direction.

5. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 4, characterized in that: The adjustment platform (1) further comprises a rotating module, the rotating module is connected to the X-axis linear module, the support plate is connected to the rotating module, and the rotating module is used to drive the support plate to rotate around its own axis.

6. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 1, characterized in that: The substrate (2) is transparent glass.

7. The device for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 1, characterized in that: The amorphous soft magnetic tape (3) is made of an iron-based amorphous soft magnetic alloy Metglas.

8. A method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape, characterized in that: The method is carried out based on the Micro-LED chip mass transfer device based on amorphous soft magnetic tape according to any one of claims 1 to 7, and the method comprises the following steps: S1, preparing a Micro-LED chip, and inverting the prepared Micro-LED chip onto a blue film, and then placing the blue film and the Micro-LED chip on an adjustment platform (1); S2, adjusting the positions of the Micro-LED chips by adjusting the platform (1) so that the positions of the plurality of Micro-LED chips correspond to the positions of the plurality of openings (4) on the amorphous soft magnetic tape material (3); S3, turning on the electromagnet device, and controlling the magnetization intensity in the amorphous soft magnetic tape material (3) and the stray magnetic field at the opening (4) through the energized coil (6) of the electromagnet device, thereby controlling the adsorption force on the Micro-LED chip, and then transferring the Micro-LED chip from the blue film to the substrate (2), and then reducing the current of the energized coil (6) to reduce the magnetic field, thereby completing the mass transfer of the Micro-LED chips.

9. The method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 8, characterized in that: The preparation of the Micro-LED chip in step S1 specifically includes: Prepare sapphire-based blue light epitaxial wafers, and complete the preparation of Micro-LED chips according to the size of Micro-LED chips to form wafers; After the wafer is thinned and polished to a preset thickness, a magnetic material is deposited on the back side of the wafer to a preset thickness to form a magnetic layer; The wafer is diced and inverted onto a blue film, and a plurality of Micro-LED chips with a magnetic layer facing upward are formed on the blue film.

10. The method for mass transfer of Micro-LED chips based on amorphous soft magnetic tape according to claim 9, characterized in that: The magnetic material includes one of cobalt, iron and its alloys, nickel and its alloys, rare earth and its alloys, and manganese compounds.

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