Device for applying magnetic powder layer to LED chip and magnetizing and demagnetizing LED chip and manufacturing method of magnetized chip

Abstract

The invention discloses a device for applying a magnetic powder layer to an LED chip and magnetizing and demagnetizing the LED chip and a manufacturing method of a magnetized chip, and relates to the technical field of semiconductors. The device comprises a gas storage tank, a ventilation pipeline, a flow metering valve, a powder feeder, a classifier, a deposition chamber, a main controller and a vacuum pump, the deposition chamber and the gas storage tank are connected to the two ends of the ventilation pipeline respectively, and the ventilation pipeline is sequentially connected with the flow metering valve, the powder feeder and the classifier from left to right. A cushion block, a three-dimensional motion platform, a magnetizing and demagnetizing device, a carrying substrate, a chip blue film, an LED chip and a powder spraying box are sequentially arranged in the deposition chamber from bottom to top. According to the LED chip magnetic powder layer applying and magnetizing and demagnetizing device and the manufacturing method of the magnetized chip, miniature magnetic powder films with different thicknesses can be deposited on the chip according to needs, the chip can be magnetized, the working environment is relatively simple, and the operation can be carried out at room temperature.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a method for manufacturing an LED chip applying a magnetic powder layer, a magnetizing and demagnetizing device, and a magnetizing chip. Background Art

[0002] In recent years, in the field of display technology, Mini / Micro-LED display technology is becoming an important force in promoting the innovation of display technology due to its significant advantages in key performance indicators such as luminous efficiency, power consumption, contrast, response speed and life.

[0003] Mass transfer technology is a key step in Micro-LED display technology, which involves transferring tiny LED chips from the growth substrate to the target substrate or driver circuit board. This technology is essential to achieving the advantages of high resolution, high brightness and low power consumption of Micro-LED display screens. Micro-LED mass transfer technology includes a variety of different technical schools, including laser transfer technology, contact transfer technology, self-assembly technology, etc. Among them, self-assembly technology uses media such as fluids and electromagnetic fields to achieve the orientation and positioning of microcomponents on the corresponding substrate positions through shape recognition or self-selective colloids.

[0004] Aerosol Deposition Method (ADM), also known as vapor deposition method, is a newly developed surface coating preparation method. It proposes to directly suspend ultrafine powders through gas to form an aerosol. At room temperature and low vacuum environment, high-speed airflow is used to float, atomize and accelerate ultrafine spray particles, which are then deposited on the clean substrate surface to form a coating.

[0005] Magnetization refers to magnetizing magnetic materials or increasing the magnetism of magnets with insufficient magnetism. Generally, the magnetic object to be magnetized is placed in the magnetic field formed by a coil with direct current passing through it. The principle is: a momentary pulse of large current passes through the coil, causing the coil to generate a short-term super-strong magnetic field, making the magnetized object magnetic.

[0006] In the existing technology, patent application CN202311425183.7 mentions a method for coating LED chips, which uses a magnetron sputtering process to coat nano-precious metal particles, and prepares a phosphor layer by combining screen printing with laser ablation technology. However, this process involves multiple steps, including screen printing, laser ablation, etc., which increases the complexity of the manufacturing process, and the laser ablation process may cause thermal damage to the chip, affecting the performance and luminous efficiency of the material.

[0007] Patent application CN202310499328.1 mentions the deposition of Fe3O4 magnetic nanoparticles on the electrodes of the Micro-LED chip, so that the chip can be magnetized. It combines magnetic materials and microelectronics processes to provide a new Micro-LED chip bonding solution. However, the intensity and distribution of the magnetic field need to be precisely controlled, and the compatibility of the magnetic nanoparticles with the chip and substrate materials needs to be ensured. The deposition process needs to be precisely controlled to ensure the uniformity and coverage of the Fe4O4 particles. Summary of the invention

[0008] The purpose of the present invention is to provide a device for applying a magnetic powder layer and magnetizing and demagnetizing an LED chip, which can deposit micro magnetic powder films of different thicknesses on the chip as needed and magnetize the chip, and its working environment is relatively simple and can be carried out at room temperature.

[0009] To achieve the above-mentioned purpose, the present invention provides a device for applying a magnetic powder layer and magnetizing and demagnetizing an LED chip, comprising a gas storage tank, a ventilation pipeline, a flow metering valve, a powder feeder, a granulator, a deposition chamber, a main controller and a vacuum pump, wherein the vacuum pump and the main controller are both connected to the deposition chamber, the deposition chamber and the gas storage tank are respectively connected to the two ends of the gas pipeline, and the ventilation pipeline is sequentially connected to the flow metering valve, the powder feeder and the granulator from left to right;

[0010] The deposition chamber is provided with a cushion block, a three-dimensional motion platform, a charging and demagnetizing device, a carrier substrate, a chip blue film, an LED chip and a powder spray box in sequence from bottom to top. The upper end of the powder spray box is connected to the ventilation duct, and the lower end of the powder spray box is provided with a plurality of nozzles.

[0011] Preferably, a flow sensor for controlling the gas flow and monitoring the gas flow rate is provided inside the flow metering valve.

[0012] Preferably, the powder feeder is a rotating brush aerosol generator, which pushes the piston in the powder storage tank through a stepper motor to move the magnetic powder particles upward, and then the brush lifts the magnetic powder on the contact surface and blows it out with a high-speed airflow.

[0013] Preferably, the powder feeder is capable of generating a low-concentration solid particle aerosol within a mass flow rate range of 0.04 g / h-800 g / h.

[0014] Preferably, the powder feeder can easily and repeatably determine the mass flow rate of the dust according to the set feed rate and the cross-sectional area of ​​the storage tank and the compaction density of the powder.

[0015] Preferably, the classifier is used to classify the aerosol delivered by the powder feeder, and a filter screen is provided inside the classifier for filtering out larger particles or particle clusters.

[0016] Preferably, the nozzle is configured as a rectangular structure with a size of 0.5 mm×0.1 mm.

[0017] Preferably, the three-dimensional motion platform realizes relative motion of the nozzle via a mobile platform, and is directly controlled by the main controller.

[0018] Preferably, the main controller can control the dynamic cooperation between the three-dimensional motion platform and the nozzle in real time to ensure the uniformity of the vapor-deposited magnetic powder particles.

[0019] Preferably, the charging and demagnetizing device comprises an internal armature and an external coil, and the external coil is arranged on both sides of the internal armature.

[0020] Preferably, the device uses a vapor deposition method (ADM) to deposit a magnetic powder layer on the chip, and the environment only requires low temperature and low vacuum, which has little impact on the chip.

[0021] A method for manufacturing a magnetized chip with a magnetic powder layer and a magnetization and demagnetization device for an LED chip, the steps are as follows:

[0022] S1, making multiple LED chips and magnetic powder particles;

[0023] S2, apply glue to the bottom layer of the LED chip, then paste the LED chip on the chip blue film, and then place the chip blue film on the carrier substrate;

[0024] S3, adjusting the positions of the three-dimensional motion platform, the charging and demagnetizing device and the nozzle, and the main controller obtains the three-dimensional coordinates;

[0025] S4, putting magnetic powder into the powder feeder;

[0026] S5. Connect all parts of the system, set the pressure in the deposition chamber, start the vacuum pump for adjustment, and check the air tightness and various parameters in the deposition chamber;

[0027] S6, open the flow metering valve to pass the carrier gas into the powder feeder;

[0028] S7, the powder feeder mixes the magnetic powder and the carrier gas uniformly and blows them out by the high-speed airflow;

[0029] S8, then the aerosol is filtered out through a granulator to remove larger particles or particle clusters to make the aerosol more uniform;

[0030] S9, then it reaches the powder spraying box and is sprayed out through the nozzle. The nozzle and the three-dimensional motion platform cooperate with each other to evenly deposit the magnetic powder aerosol on the surface of the chip electrode;

[0031] S10, after the magnetic powder layer is deposited to a predetermined thickness, the demagnetization device is turned on to magnetize the LED chip with the magnetic powder layer applied thereto, and after the magnetization is completed, the blue film of the chip is removed to obtain a magnetized LED chip with a magnetic powder layer.

[0032] Preferably, the thickness of the magnetic powder layer of the magnetized LED chip is 2 μm-5 μm.

[0033] Preferably, 50Hz alternating current is passed through the LED chip when magnetizing, and the capacitor group in its external circuit is instantaneously charged and discharged to obtain a very large unidirectional pulse magnetizing current, generating a large instantaneous magnetic field. The charging process lasts for at least 10ms. When demagnetization is required, variable frequency alternating current is passed through, and then the amplitude of the variable frequency magnetic field is gradually reduced to 0. The demagnetization time lasts for at least 30ms.

[0034] Beneficial effects of the present invention:

[0035] This device integrates gas storage, precise metering, aerosol mixing, filtration and granulation, uniform injection, vacuum deposition, automatic control, and demagnetization functions, achieving efficient, uniform and precise magnetization of the magnetic powder layer deposition process of LED chips. The design of the device cleverly combines the rotating brush aerosol generator and the granulator to ensure the uniform mixing of magnetic powder and gas and the fine filtration of aerosol, while the collaborative operation of the three-dimensional mobile platform and the main controller achieves a high degree of automation and precise control of the deposition process. In addition, the flexibility of the device is reflected in its adaptability to different gases, different magnetic powder materials (such as ferrites such as Fe3O4, Mn-ZnFe2O4, Ni-ZnFe2O4) and different thicknesses (2μm-5μm), meeting diverse process requirements.

[0036] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of a method for manufacturing a magnetic powder layer and a magnetizing and demagnetizing device and a magnetized chip of an LED chip according to the present invention;

[0038] Figure 2 Schematic diagram of nozzle spraying magnetic powder aerosol according to an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of magnetic powder aerosol deposition according to an embodiment of the present invention;

[0040] Figure 4 A schematic diagram of applying a magnetic powder layer to a chip according to an embodiment of the present invention;

[0041] Figure 5 This is a partial enlarged view of applying a magnetic powder layer to a chip according to an embodiment of the present invention;

[0042] Figure 6 A schematic structural diagram of a charging and demagnetizing device according to an embodiment of the present invention;

[0043] Figure 7 Schematic diagram of chip magnetization according to an embodiment of the present invention.

[0044] Reference numerals

[0045] 1. Gas storage tank; 2. Ventilation pipe; 3. Flow metering valve; 4. Powder feeder; 5. Grain classifier; 6. Deposition chamber; 7. Main controller; 8. Powder spray box; 9. Magnetic powder aerosol; 10. Nozzle; 11. LED chip; 1101. Magnetized material layer; 1102. Chip electrode; 1103. Chip light-emitting layer; 1104. Magnetic powder layer; 12. Chip blue film; 13. Carrier substrate; 14. Charging and demagnetizing device; 1401. Internal armature; 1402. External coil; 15. Three-dimensional motion platform; 16. Pad; 17. Vacuum pump. DETAILED DESCRIPTION

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0047] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0049] Example

[0050] like Figure 1-7As shown, a device for applying a magnetic powder layer and magnetizing and demagnetizing an LED chip comprises a gas storage tank 1, a ventilation pipe 2, a flow metering valve 3, a powder feeder 4, a granulator 5, a deposition chamber 6, a main controller 7 and a vacuum pump 17. The vacuum pump 17 and the main controller 7 are both connected to the deposition chamber 6. The deposition chamber 6 and the gas storage tank 1 are respectively connected to the two ends of the ventilation pipe 2. The flow metering valve 3, the powder feeder 4 and the granulator 5 are sequentially connected to the ventilation pipe 2 from left to right; a cushion block 16, a three-dimensional motion platform 15, a magnetizing and demagnetizing device 14, a substrate 13, a chip blue film 12, an LED chip 11 and a powder spraying box 8 are sequentially arranged in the deposition chamber 6 from bottom to top. The upper end of the powder spraying box 8 is connected to the ventilation pipe 2, and the lower end of the powder spraying box 8 is provided with a plurality of nozzles 10; the gas storage tank 1 provides a carrier gas for the entire device, and the gas can be one or a mixture of He, N2, Air, and Ar; the vacuum pump 17 can provide air pressure for the deposition chamber 6, and the pressure of the deposition chamber 6 can be set to 1Pa-2kPa as needed.

[0051] A flow sensor for controlling gas flow and monitoring gas flow rate is arranged inside the flow metering valve 3; the powder feeder 4 is a rotating brush aerosol generator, which pushes the piston in the powder storage tank through a stepping motor to make the magnetic powder particles move upward, and then the brush brings up the magnetic powder on the contact surface and blows it out by the high-speed airflow; the granulator 5 is used to granulate the aerosol sent by the powder feeder 4, and a filter screen is arranged inside it for filtering out larger particles or particle clusters; the nozzle 10 is set as a rectangular structure with a size of 0.5mm×0.1mm, and the distance from the nozzle 10 to the carrier substrate 13 is 0.5mm-20mm; the three-dimensional motion platform 15 realizes relative movement of the nozzle 10 through a mobile platform, and it is directly controlled by the main controller 7; the charging and demagnetization device 14 includes an internal armature 1401 and an external coil 1402, and the external coil 1402 is arranged on both sides of the internal armature 1401.

[0052] A method for manufacturing a magnetized chip with a magnetic powder layer and a magnetization and demagnetization device for an LED chip, the steps are as follows:

[0053] S1, manufacturing a plurality of LED chips 11 and manufacturing magnetic powder particles;

[0054] S2, brush glue on the bottom layer of the LED chip 11, then paste the LED chip 11 on the chip blue film 12, and then place the chip blue film 12 on the carrier substrate 13;

[0055] S3, adjusting the positions of the three-dimensional motion platform 15, the charging and demagnetizing device 14 and the nozzle 10, and the main controller 7 obtains the three-dimensional coordinates;

[0056] S4, putting magnetic powder into powder feeder 4;

[0057] S5. Connect all parts of the system, set the air pressure in the deposition chamber 6, start the vacuum pump 17 for adjustment, and check the air tightness and various parameters in the deposition chamber 6;

[0058] S6, open the flow metering valve 3 to pass the carrier gas into the powder feeder 4;

[0059] S7, the powder feeder 4 mixes the magnetic powder and the carrier gas uniformly and blows them out by the high-speed airflow;

[0060] S8, then the larger particles or particle clusters are filtered out by the classifier 5 to make the aerosol more uniform;

[0061] S9, then it reaches the powder spraying box 8 and is sprayed out through the nozzle 10, and the nozzle 10 and the three-dimensional motion platform 15 cooperate with each other to evenly deposit the magnetic powder aerosol 9 on the surface of the chip electrode 1102;

[0062] S10, after the magnetic powder layer 1104 is deposited to a predetermined thickness, the demagnetization device 14 is turned on to magnetize the LED chip 11 with the magnetic powder layer 1104 applied thereto. After the magnetization is completed, the chip blue film 12 is removed to obtain the magnetized LED chip 11 with the magnetic powder layer 1104.

[0063] The magnetic powder is Fe3O4, manganese-zinc ferrite Mn-ZnFe2O4, nickel-zinc ferrite Ni-ZnFe2O4 and other ferrites, and its particle diameter is 0.5μm-2μm; the thickness of the magnetic powder layer 1104 of the magnetized LED chip 11 is 2μm-5μm; when the LED chip 11 is magnetized, 50Hz alternating current is passed, and the capacitor group in its external circuit can be charged and discharged instantaneously to obtain a large unidirectional pulse magnetization current, generating a large instantaneous magnetic field, and the charging process lasts at least 10ms. When demagnetization is required, variable frequency alternating current is passed, and then the amplitude of the variable frequency magnetic field is gradually reduced to 0, and the demagnetization time lasts at least 30ms.

[0064] Specific working principle: The gas storage tank 1 is used to provide carrier gas for the entire system. The gas is transported through the ventilation pipe 2. When necessary, the flow metering valve 3 is opened to control the gas flow. Then the carrier gas passes through the powder feeder 4. The powder feeder 4 is filled with magnetic powder. The piston in the powder storage tank is pushed by a stepper motor to make the magnetic powder particles move upward. Then the brush brings up the magnetic powder on the contact surface and blows it out by a high-speed airflow to form a magnetic powder aerosol 9. The magnetic powder aerosol 9 is sent to the nozzle 10 after filtering out larger particles or particle clusters through the granulator 5. The uniform magnetic powder aerosol 9 is sprayed out through the nozzle 10 and evenly deposited on the LED chip 11; the LED chip 11 is closely arranged on the chip blue film 12, and the chip light-emitting layer 1103 faces downward. The chip electrode 1102 faces upward, and the magnetic powder aerosol 9 is deposited on the chip electrode 1102 at a certain rate. The LED chip 11 has a magnetized material layer 1101, which is composed of 0.1μm-0.5μm iron, cobalt, nickel and other magnetized materials. The chip blue film 12 is fixed on the carrier substrate 13. Below the carrier substrate 13 is a charging and demagnetizing device 14, which is connected to an external control circuit. Directly below it is a three-dimensional motion platform 15. The main controller 7 obtains the three-dimensional coordinates of the three-dimensional motion platform 15 in real time, and can adjust the relative movement of the nozzle 10 and the LED chip 11 as needed, so that the deposition of the magnetic powder aerosol 9 is more uniform. The vacuum pump 17 can provide air pressure conditions for the deposition chamber 6 to facilitate vapor deposition.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for applying a magnetic powder layer and magnetizing and demagnetizing an LED chip, characterized in that: It includes a gas storage tank, a ventilation pipeline, a flow metering valve, a powder feeder, a granulator, a deposition chamber, a main controller and a vacuum pump, wherein the vacuum pump and the main controller are connected to the deposition chamber, the deposition chamber and the gas storage tank are respectively connected to the two ends of the ventilation pipeline, and the ventilation pipeline is sequentially connected with the flow metering valve, the powder feeder and the granulator from left to right; The deposition chamber is provided with a cushion block, a three-dimensional motion platform, a charging and demagnetizing device, a carrier substrate, a chip blue film, an LED chip and a powder spray box in sequence from bottom to top. The upper end of the powder spray box is connected to the ventilation duct, and the lower end of the powder spray box is provided with a plurality of nozzles.

2. The device for applying a magnetic powder layer and magnetizing and demagnetizing an LED chip according to claim 1, characterized in that: A flow sensor for controlling gas flow and monitoring gas flow velocity is arranged inside the flow metering valve.

3. The device for applying magnetic powder layer and magnetizing and demagnetizing LED chip according to claim 1, characterized in that: The powder feeder is a rotating brush aerosol generator, which pushes the piston in the powder storage tank through a stepper motor to make the magnetic powder particles move upward, and then the brush brings up the magnetic powder on the contact surface and blows it out by the high-speed airflow.

4. The device for applying magnetic powder layer and magnetizing and demagnetizing LED chip according to claim 1, characterized in that: The classifier is used to classify the aerosol sent by the powder feeder, and a filter screen is arranged inside the classifier to filter out larger particles or particle clusters.

5. The device for applying magnetic powder layer and magnetizing and demagnetizing LED chip according to claim 1, characterized in that: The nozzle is configured as a rectangular structure with a size of 0.5 mm×0.1 mm.

6. The device for applying magnetic powder layer and magnetizing and demagnetizing LED chip according to claim 1, characterized in that: The three-dimensional motion platform realizes the relative motion of the nozzle through the mobile platform, and is directly controlled by the main controller.

7. The device for applying magnetic powder layer and magnetizing and demagnetizing LED chip according to claim 1, characterized in that: The charging and demagnetizing device comprises an internal armature and an external coil, and the external coil is arranged on both sides of the internal armature.

8. A method for manufacturing a magnetized chip with a magnetic powder layer and a magnetizing and demagnetizing device for an LED chip according to any one of claims 1 to 7, characterized in that: Here are the steps: S1, making multiple LED chips and magnetic powder particles; S2, apply glue to the bottom layer of the LED chip, then paste the LED chip on the chip blue film, and then place the chip blue film on the carrier substrate; S3, adjusting the positions of the three-dimensional motion platform, the charging and demagnetizing device and the nozzle, and the main controller obtains the three-dimensional coordinates; S4, putting magnetic powder into the powder feeder; S5. Connect all parts of the system, set the pressure in the deposition chamber, start the vacuum pump for adjustment, and check the air tightness and various parameters in the deposition chamber; S6, open the flow metering valve to pass the carrier gas into the powder feeder; S7, the powder feeder mixes the magnetic powder and the carrier gas uniformly and blows them out by the high-speed airflow; S8, then the aerosol is filtered out through a granulator to remove larger particles or particle clusters to make the aerosol more uniform; S9, then it reaches the powder spraying box and is sprayed out through the nozzle. The nozzle and the three-dimensional motion platform cooperate with each other to evenly deposit the magnetic powder aerosol on the surface of the chip electrode; S10, after the magnetic powder layer is deposited to a predetermined thickness, the demagnetization device is turned on to magnetize the LED chip with the magnetic powder layer applied thereto, and after the magnetization is completed, the blue film of the chip is removed to obtain a magnetized LED chip with a magnetic powder layer.

9. The method for manufacturing a magnetized chip with a magnetic powder layer and a magnetizing and demagnetizing device for an LED chip according to claim 8, characterized in that: The thickness of the magnetic powder layer of the magnetized LED chip is 2 μm-5 μm.

10. The method for manufacturing a magnetized chip with a magnetic powder layer and a magnetizing and demagnetizing device for an LED chip according to claim 8, characterized in that: When the LED chip is magnetized, 50Hz alternating current is passed through, and the capacitor group in its external circuit is instantaneously charged and discharged to obtain a large unidirectional pulse magnetization current, generating a large instantaneous magnetic field. The charging process lasts for at least 10ms. When demagnetization is required, variable frequency alternating current is passed through, and then the amplitude of the variable frequency magnetic field is gradually reduced to 0. The demagnetization time lasts for at least 30ms.

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