Contactless MicroLED chip mass transfer method and system

Abstract

The invention relates to a non-contact MicroLED chip mass transfer method and system, and the method comprises the following steps: carrying out the spin coating of a layer of photolysis viscoelastic material on the surface of quartz glass, carrying out the curing, carrying out the spin coating of a layer of viscous flexible deformation material on the surface of the photolysis viscoelastic material, and carrying out the curing again, thereby completing the preparation of a first temporary substrate; scanning the sapphire substrate with the MicroLED chip through laser transfer equipment, decomposing gallium nitride to generate gas, and pushing the MicroLED chip to be transferred to the first temporary substrate; scanning the first temporary substrate through the laser transfer equipment again, and enabling the photolysis viscoelastic material to be photolyzed and gasified by the laser to push the flexible deformation material with viscosity to deform so as to transfer the MicroLED chip to the second temporary substrate; and carrying out hot pressing bonding on the MicroLED chip on the second temporary substrate to the thin film transistor substrate with the metal bumps through transfer bonding equipment.

Description

Technical Field

[0001] The present invention relates to a contactless MicroLED chip mass transfer method and system, belonging to the field of semiconductor technology. Background Art

[0002] Micro-LED display technology refers to a display technology that uses self-luminous micron-sized LEDs as light-emitting pixel units and assembles them on a drive panel to form a high-density LED array. Due to the small size, high integration and self-luminescence of Micro-LED display chips, it has greater advantages in brightness, resolution, contrast, energy consumption, service life, response speed and thermal stability compared to LCD and OLED displays. The display devices used in Micro-LED display technology are mostly small electronic devices, and the size of the electronic devices usually used is less than 50μm. The display effect is achieved by forming a light-emitting matrix through electronic devices. Due to the many advantages of Micro-LED display technology such as high display quality and long service life, Micro-LED display technology has attracted the attention of relevant researchers and scholars around the world. In the future, Micro-LED display technology will also become a key technology in the global display field to be developed and promoted.

[0003] Mass transfer is an important technology for Micro-LED display technology to achieve full color. Full color can bring more advantages and help to Micro-LED display. However, due to the limitations of current scientific and technological levels, full-color Micro-LED display technology has shortcomings such as insufficient stability and low efficiency. In actual use, Micro-LED display technology needs to use mass transfer technology to accurately transfer Micro-LEDs of different colors. Laser transfer has many advantages such as high efficiency and high precision, making it one of the most promising methods to solve the problem of mass transfer.

[0004] However, in traditional laser transfer schemes, photolytic vaporized materials are usually used directly as temporary substrates. Due to the limitations of the material's viscosity and flexibility, the chip must be laser-peeled by hot-pressing the COW to the material surface during the first transfer process. This limits the arrangement of the chip on the temporary substrate, and the peeling efficiency is low. The presence of sapphire warping further leads to a low chip retention rate on the temporary substrate surface. In the secondary transfer process, since the photolytic vaporized material is in direct contact with the chip, residual glue will inevitably remain on the chip surface, which needs to be cleaned with a specific solvent, making it more likely to cause the chip to fall off and the spacing to change. At the same time, the cleaned sample cannot be repaired. This ultimately leads to many problems such as low sample yield, low production efficiency, and high cost.

[0005] The invention patent with the announcement number "CN116995017A" discloses a micro-LED mass transfer device and method based on laser technology, including a driving layer, an expandable microsphere layer, a packaging film layer and a viscous layer arranged in sequence from top to bottom, wherein a plurality of cavities are arranged inside the driving layer, and an expandable microsphere layer is arranged in each cavity. The packaging film layer is arranged below the driving layer, and the viscous layer is arranged below the packaging film layer for contacting the microLED to be transferred. The laser is irradiated on the top of the driving layer, and the laser is irradiated into the cavity through the driving layer to expand the expandable microsphere layer. The invention heats the driving layer by laser. The method of expandable microspheres indirectly promotes chip separation, solving the problem of chip thermal damage caused by laser factors. At the same time, the invention matches the micro-spacing between microLED and receiving substrate through the rapid laser bubbling height and the interface viscosity between microLED and transfer device, so that the microLED chip and the receiving substrate are in a non-contact state before laser heating, achieving high-precision and high-reliability transfer, significantly improving the transfer accuracy and efficiency of microLED. At the same time, during the release process, the transfer device does not need to be in full contact with the receiving substrate, so the influence of the flatness error on the transfer success rate is greatly reduced, thereby ensuring the transfer accuracy. However, the microLED chip in the above scheme still uses contact laser stripping of the microLED chip, so the sample yield will still be affected by factors such as bonding parallelism. At the same time, the adhesive layer of the transfer device proposed in the above scheme can only be used as a transfer material and cannot receive the chip without contact. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present invention proposes a contactless MicroLED chip mass transfer method and system.

[0007] The technical solution of the present invention is as follows: In one aspect, the present invention provides a contactless MicroLED chip mass transfer method, comprising the following steps: A layer of photodegradable viscoelastic material is spin-coated on the surface of the quartz glass, and after curing, a layer of viscous flexible deformable material is spin-coated on the surface of the photodegradable viscoelastic material, and after curing again, the preparation of the first temporary substrate is completed; The sapphire substrate with the MicroLED chip is scanned by a laser transfer device to decompose the gallium nitride to generate gas, which drives the MicroLED chip to be transferred to the first temporary substrate; The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodegraded and gasified, pushing the viscous flexible deformable material to deform, so that the MicroLED chip is transferred to the second temporary substrate; The MicroLED chip on the second temporary substrate is thermally pressed and bonded to the thin film transistor substrate with metal bumps through transfer bonding equipment.

[0008] As a preferred embodiment of the present invention, the chip transfer release material is spin-coated on the glass surface and then cured to obtain the prepared second temporary substrate.

[0009] As a preferred embodiment of the present invention, when the MicroLED chips on the sapphire substrate are transferred to the first temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0010] As a preferred embodiment of the present invention, when the MicroLED chips on the first temporary substrate are transferred to the second temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0011] On the other hand, the present invention also provides a contactless MicroLED chip mass transfer system, including a temporary substrate preparation module, a laser transfer module, and a transfer bonding module; The temporary substrate preparation module is used to spin-coat a layer of photodegradable viscoelastic material on the surface of the quartz glass, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material after curing, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material, and then cure again to complete the preparation of the first temporary substrate; The laser transfer module is used to scan the sapphire substrate with the MicroLED chip by laser, so that the gallium nitride is decomposed to generate gas, and the MicroLED chip is transferred to the first temporary substrate. The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodecomposed and gasified to drive the viscous flexible deformation material to deform, so that the MicroLED chip is transferred to the second temporary substrate. The transfer bonding module is used to thermally press-bond the MicroLED chip on the second temporary substrate to a thin film transistor substrate with metal bumps.

[0012] As a preferred embodiment of the present invention, the temporary substrate preparation module obtains the prepared second temporary substrate by spin coating the chip transfer release material on the glass surface and curing it.

[0013] As a preferred embodiment of the present invention, when the laser transfer module transfers the MicroLED chips on the sapphire substrate to the first temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0014] As a preferred embodiment of the present invention, when the laser transfer module transfers the MicroLED chips on the first temporary substrate to the second temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0015] On the other hand, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present invention when executing the program.

[0016] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the present invention.

[0017] The present invention has the following beneficial effects: 1. The present invention uses photodegradable viscoelastic materials to contactlessly receive and release chips, which can effectively solve the problem of residual glue on MicroLED chips, low utilization rate, and poor transfer effect caused by traditional photodegradable gasified material transfer in the background technology. It can also directly perform selective transfer and spacing rearrangement of chips in a contactless manner, saving production costs, improving the yield of flip chip temporary substrate preparation, and the degree of freedom of chip transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of preparing a first temporary substrate according to an embodiment of the present invention; Figure 2 A flow chart for preparing a second temporary substrate according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the one-time transfer principle of the MicroLED chip of the present invention; Figure 4 This is a schematic diagram of the secondary transfer principle of the MicroLED chip of the present invention; Figure 5 Schematic diagram of the thermal compression bonding principle of the MicroLED chip of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0021] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0022] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0023] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0024] Embodiment 1: See also Figure 1 , a contactless MicroLED chip mass transfer method, comprising the following steps: A layer of photodegradable viscoelastic material is spin-coated on the surface of the quartz glass, and after curing, a layer of viscous flexible deformable material is spin-coated on the surface of the photodegradable viscoelastic material, and after curing again, the preparation of the first temporary substrate is completed; The sapphire substrate with the MicroLED chip is scanned by a laser transfer device to decompose the gallium nitride to generate gas, which drives the MicroLED chip to be transferred to the first temporary substrate; The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodegraded and gasified, pushing the viscous flexible deformable material to deform, so that the MicroLED chip is transferred to the second temporary substrate; The MicroLED chip on the second temporary substrate is thermally pressed and bonded to the thin film transistor substrate with metal bumps through transfer bonding equipment.

[0025] Specifically, in this embodiment, the mass transfer of MicroLED chips is performed through the following steps: S1. See Figure 1 , spin-coat and solidify a layer of about to A photodegradable viscoelastic material 2 (synthesized from 40 parts of polyols such as polycaprolactone diol, 8 parts of isophorone diisocyanate, 3 parts of hydroxyethyl methacrylate, 50 parts of n-butyl acrylate and 9 parts of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide) is then spin-coated and cured on the surface of the photodegradable viscoelastic material 2 with a thickness of about to A viscous and flexible deformable material 3 (such as silicone rubber, polyester fiber, etc.) is used to complete the preparation of the first temporary substrate; S2, see Figure 2 , spin-coat and solidify a layer of to The chip transfer release material 5 (such as a polyurethane derivative) is used to complete the preparation of the second temporary substrate; S3, placing the sapphire substrate with the MicroLED chips and the first temporary substrate into a laser transfer device, and setting corresponding parameters according to the required chip spacing and quantity; S4. See Figure 3 , using an energy density of about 1000 mJ / cm 2 -1200 mJ / cm 2 , a laser with a wavelength of 266 nm scans the MicroLED chip 5, so that GaN decomposes to produce N2, pushing the chip down to the surface of the first temporary substrate; S5, placing the first temporary substrate and the second temporary substrate with the MicroLED chips 5 into the laser device, and setting corresponding parameters according to the required chip spacing and quantity; S6. See Figure 4 , using an energy density of about 500 mJ / cm 2 -1000 mJ / cm 2 , a laser with a wavelength of 266 nm scans the photodegradable viscoelastic material 2, and the gas generated after the photodegradable viscoelastic material is vaporized causes the viscous flexible deformable material 3 to bulge, pushing the MicroLED chip 5 to fall onto the second temporary substrate; S7, see Figure 5 , place the second temporary substrate into the transfer bonding device, and use the pressure head 8 to thermally press-bond the MicroLED chip 5 to the thin film transistor substrate 10 with the metal bumps 9.

[0026] As a preferred implementation of this embodiment, the first layer of material spin-coated on the quartz glass can be any photolytic material with viscoelasticity, not limited to a certain material; As a preferred implementation of this embodiment, the second layer material spin-coated on the quartz glass can be any flexible and sticky material, not limited to a certain material; As a preferred implementation of this embodiment, the spacing of the MicroLED chips on the sapphire substrate can be arbitrary; As a preferred implementation of this embodiment, the arrangement of the MicroLED chips on the first temporary substrate can be arbitrary; As a preferred implementation of this embodiment, the second temporary substrate may be any material that can receive and release the chip; As a preferred implementation of this embodiment, the arrangement of the MicroLED chips on the second temporary substrate can be arbitrary; As a preferred implementation manner of this embodiment, the metal bumps on the thin film transistor substrate are not limited to any metal.

[0027] Embodiment 2: A contactless MicroLED chip mass transfer system, comprising a temporary substrate preparation module, a laser transfer module and a transfer bonding module; The temporary substrate preparation module is used to spin-coat a layer of photodegradable viscoelastic material on the surface of the quartz glass, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material after curing, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material, and then cure again to complete the preparation of the first temporary substrate; The laser transfer module is used to scan the sapphire substrate with the MicroLED chip by laser, so that the gallium nitride is decomposed to generate gas, and the MicroLED chip is transferred to the first temporary substrate. The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodecomposed and gasified to drive the viscous flexible deformation material to deform, so that the MicroLED chip is transferred to the second temporary substrate. The transfer bonding module is used to thermally press-bond the MicroLED chip on the second temporary substrate to a thin film transistor substrate with metal bumps.

[0028] As a preferred implementation manner of this embodiment, the temporary substrate preparation module obtains the prepared second temporary substrate by spin coating the chip transfer release material on the glass surface and curing it.

[0029] As a preferred implementation manner of this embodiment, when the laser transfer module transfers the MicroLED chips on the sapphire substrate to the first temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0030] As a preferred implementation manner of this embodiment, when the laser transfer module transfers the MicroLED chips on the first temporary substrate to the second temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

[0031] This system is used to implement the functions in the first embodiment, which will not be described in detail here.

[0032] Embodiment three: This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present invention when executing the program.

[0033] Embodiment 4: This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present invention is implemented.

[0034] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0035] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0036] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0037] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0038] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A contactless MicroLED chip mass transfer method, characterized in that: The following steps are involved: A layer of photodegradable viscoelastic material is spin-coated on the surface of the quartz glass, and after curing, a layer of viscous flexible deformable material is spin-coated on the surface of the photodegradable viscoelastic material, and after curing again, the preparation of the first temporary substrate is completed; The sapphire substrate with the MicroLED chip is scanned by a laser transfer device to decompose the gallium nitride to generate gas, which drives the MicroLED chip to be transferred to the first temporary substrate; The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodegraded and gasified, pushing the viscous flexible deformable material to deform, so that the MicroLED chip is transferred to the second temporary substrate; The MicroLED chip on the second temporary substrate is thermally pressed and bonded to the thin film transistor substrate with metal bumps through transfer bonding equipment.

2. The contactless MicroLED chip mass transfer method according to claim 1, characterized in that: The chip transfer release material is spin-coated on the glass surface and then cured to obtain a prepared second temporary substrate.

3. The contactless MicroLED chip mass transfer method according to claim 1, characterized in that: When the MicroLED chips on the sapphire substrate are transferred to the first temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

4. The contactless MicroLED chip mass transfer method according to claim 1, characterized in that: When the MicroLED chips on the first temporary substrate are transferred to the second temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

5. A contactless MicroLED chip mass transfer system, characterized in that: It includes a temporary substrate preparation module, a laser transfer module and a transfer bonding module; The temporary substrate preparation module is used to spin-coat a layer of photodegradable viscoelastic material on the surface of the quartz glass, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material after curing, and then spin-coat a layer of viscous flexible deformable material on the surface of the photodegradable viscoelastic material, and then cure again to complete the preparation of the first temporary substrate; The laser transfer module is used to scan the sapphire substrate with the MicroLED chip by laser, so that the gallium nitride is decomposed to generate gas, and the MicroLED chip is transferred to the first temporary substrate. The first temporary substrate is scanned again by the laser transfer device, and the laser causes the photodegradable viscoelastic material to be photodecomposed and gasified to drive the viscous flexible deformation material to deform, so that the MicroLED chip is transferred to the second temporary substrate. The transfer bonding module is used to thermally press-bond the MicroLED chip on the second temporary substrate to a thin film transistor substrate with metal bumps.

6. The contactless MicroLED chip mass transfer system according to claim 5, characterized in that: The temporary substrate preparation module obtains a prepared second temporary substrate by spin coating a chip transfer release material on a glass surface and curing the material.

7. The contactless MicroLED chip mass transfer system according to claim 5, characterized in that: When the laser transfer module transfers the MicroLED chips on the sapphire substrate to the first temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

8. The contactless MicroLED chip mass transfer system according to claim 5, characterized in that: When the laser transfer module transfers the MicroLED chips on the first temporary substrate to the second temporary substrate, the arrangement of the MicroLED chips on the first temporary substrate is adjusted by setting parameters.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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