Self-assembly method of LED display device

Abstract

A self-assembly method of an LED display device comprises the following steps that S1, a driving board is provided, a plurality of bonding pads are arranged on the front face of the driving board, and each bonding pad is provided with first metal; s2, the driving plate is heated to a first temperature interval higher than the melting point of the first metal, so that the first metal is molten to form a liquid metal adhesion point; s3, a large number of LED devices provided with soft magnetic layers are applied to one side of the front face of the driving board; s4, a first magnetic adsorption piece is arranged on one side of the back face of the driving board, the LED device is adsorbed to the front face of the driving board, and the welding face of the LED device is made to be infiltrated and adhered to the liquid metal adhesion points so as to be captured by the bonding pad; s5, removing the LED devices which are not captured by the bonding pad on the driving board; and S6, the temperature of the driving board is reduced, so that the liquid metal bonding points are solidified to form welding, and the LED display device is manufactured. The manufacturing efficiency of the LED array device can be greatly improved, the requirement of mass production is met, and the manufacturing cost can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor display, and in particular to a self-assembly method of an LED display device. Background Art

[0002] Applying third-generation semiconductors to displays is an important development direction of display technology. Among them, LED display devices that use semiconductor light-emitting devices LED as display units or pixels set on display driver boards have excellent display performance (high brightness, high contrast, high color gamut, wide viewing angle, fast response), low energy consumption, and long life. Whether it is used as a direct display or as a partition backlight for liquid crystal display, it is considered to be a more advanced display technology than traditional liquid crystal display and organic light-emitting display.

[0003] At present, such LED display devices generally include super-large LED curtain walls, and the display unit spacing can reach the centimeter level. Although the manufacturing difficulty is low, since each display unit needs to weld an LED lamp bead, the manufacturing efficiency is low and the cost is very high. Such LED display devices also include Mini-LED displays and Micro-LED displays. Mini-LED displays are LED display devices with display spacing at the millimeter level. At this stage, Mini-LED can be used as a direct display or as a partition backlight (local dimming) of a liquid crystal display. It generally adopts chip binding technology to bind LED chips one by one to the display unit position. Since a huge number of LED chips need to be bound, its manufacturing efficiency is also low and the cost is high. Micro-LED displays are LED display devices with display unit pitch below a millimeter. Due to the small display unit pitch and huge number, mass transfer technology is generally required to transfer the LED light-emitting body from the LED growth wafer (such as the epitaxial board used to grow LEDs) to the display unit positions of the display driver board. Currently, mass transfer technology is not yet mature. Although it can be transferred batch by batch through a transfer head, its efficiency is still low and the defect rate is high, which cannot meet the requirements of mass production.

[0004] Therefore, there is no efficient technology for manufacturing such LED display devices at present, and it is impossible to efficiently set a large number of LEDs at the display unit position of the display driver board to reduce the manufacturing difficulty and cost of such displays. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a self-assembly method for an LED display device, which can not only greatly improve the manufacturing efficiency of the LED array device and meet the requirements of mass production, but also effectively reduce the manufacturing cost of the LED array device. The technical solution adopted is as follows: A self-assembly method for an LED display device, characterized by comprising the following steps: S1. Provide a driving board, and arrange a plurality of pads on the front side of the driving board, each pad being provided with a first metal; S2, heating the temperature of the driving board to a first temperature range higher than the melting point of the first metal, so that the first metal on each pad melts to form a liquid metal sticky point; S3, applying a large number of LED devices provided with a soft magnetic layer to a side close to the front of the driving board, each LED device including a first electrode surface and a second electrode surface facing away from each other, the first electrode surface being a non-metallic light emitting surface, and the second electrode surface being a welding surface; S4, a first magnetic adsorption component is arranged on a side close to the back of the driving board, and its magnetic end is close to the back of the driving board, the magnetic field generated by the first magnetic adsorption component generates an adsorption force on the soft magnetic layer of a large number of the LED devices through the driving board, and these LED devices are adsorbed to the front of the driving board, and the welding surfaces of at least some of the LED devices are infiltrated and adhered to the liquid metal sticking points on some of the pads so as to be captured by the pads, and the assembly state with the light emitting surface facing outward is automatically formed; S5, clear the LED devices on the driver board that are not captured by the pads; S6. Lowering the temperature of the driving board to a second temperature range lower than the melting point of the first metal, so that the liquid metal sticking point solidifies to form a weld between the wetted and adhered LED device and the soldering pad, thereby manufacturing the LED display device.

[0006] In the self-assembly method of the above-mentioned LED display device, steps S1 and S2 form liquid metal sticking points of multiple pads on the first plate body surface of the driving board. The liquid metal sticking points are formed by the first metal in a molten state attached to the pad. The first metal in a molten state has a very high surface tension (generally, the surface tension of liquid metal is about 10 times that of ordinary liquid), and at the same time, the wettability to non-metals is extremely low and the wettability to metals (such as the second metal) is extremely high, thereby making it have extremely strong adhesion selectivity. In step S3, the LED device used is a vertical structure LED provided with a soft magnetic layer, so that in step S4, by setting a first magnetic adsorption member on the back of the driving board, the LED device can be sucked tightly to the front of the driving board, and the LED device that falls on the pad is adsorbed into the liquid metal sticking point of the first metal, so that the welding surface of the LED device contacts and forms infiltration with the liquid metal sticking point, thereby greatly improving the probability that the LED device is finally captured by the pad. After the LED device is captured by the soldering pad, based on the infiltration and spread of the liquid metal sticky points on the soldering pad, the LED device and the soldering pad can be aligned and straightened through surface tension, automatically forming an assembled state with the light-emitting surface facing outward; in S6, the temperature of the driving board is lowered to the second temperature range, so that the liquid metal sticky points can solidify and the assembled LED device and the soldering pad can be welded, thereby obtaining the LED array device.

[0007] The driving board can be a printed circuit board (including a flexible circuit board), a glass board or a plastic board (such as a polyimide film) with a display driving circuit (such as a static driving circuit, a dynamic driving circuit or an active driving circuit); the pads are generally preset on the driving board and form an array, for example: they can be pre-arranged according to a pixel array.

[0008] The first electrode surface and the second electrode surface of the LED device are facing away from each other. This type of LED device is generally called a vertical structure LED device. A vertical structure LED device is an LED device or chip in which the electrodes (P pole and N pole) are located on two opposite sides of the device. In this specification, the light emitting surface and the welding surface of the LED device correspond to the P pole and N pole (or N pole and P pole) of the LED respectively. The welding surface can be a metal (such as gold, silver, copper, zinc, iron) or alloy film surface that is easily wetted by the first metal. The LED device can be an LED device with a semiconductor layer of GaAs, GaP, SiC, or GaN. Generally, the LED devices are LED devices of the same luminous color or semiconductor material, such as GaN blue light LED.

[0009] As a preferred embodiment of the present invention, the first metal is a low melting point metal. Specifically, the first metal can be a pure metal or an alloy thereof having a melting point below 400°C, for example: the first metal can be tin, bismuth, indium or an alloy thereof, such as tin-lead alloy, tin-indium alloy, tin-silver alloy, tin-lead-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy or tin-bismuth-silver alloy; the first temperature zone can be a temperature range of about 50°C slightly higher than the melting point of the first metal. Specifically, the first metal can be a tin-bismuth alloy having a melting point below 150°C, and the first temperature range can be set at 150-200°C. As a result, it can be heated in a short time and generally will not affect structures such as the driver board and LED devices.

[0010] The first metal can be pre-set on the pad by printing, coating, plating, spraying, etc. The first metal can be pre-melted and infiltrated to fully cover the pad, or pre-set on the pad in the form of a paste (such as solder paste), or attached to the pad in the form of a coating combined with a graphic. The amount of the first metal on the pad is sufficient to form sufficient infiltration coverage on the pad and the second electrode surface; and in order to prevent the melted first metal from falling off the pad and to ensure the alignment angle of the LED device, the amount of the first metal cannot be too much, and preferably the thickness or height of the first metal does not exceed half of the width of the pad.

[0011] In order to avoid the soft magnetic layer affecting the light emission, as a preferred solution of the present invention, the soft magnetic layer is arranged on the inner side of the welding surface of the LED device. Generally, the soft magnetic layer can be a soft magnetic metal (such as iron, nickel, manganese) film layer padded under the welding surface of the LED device, which has no magnetic field under normal conditions (soft magnetic metals are metals with low coercive force and high magnetic permeability, which are generally in a demagnetized state without a magnetic field), so that adjacent LED devices will not attract each other and cause agglomeration. The structure of this vertical structure LED device with a soft magnetic layer and its manufacturing method can refer to the Chinese invention patent specification with authorization announcement number CN108682725A and patent name "A vertical structure LED device and its manufacturing method".

[0012] The first magnetic adsorption member can be a permanent magnet or an electromagnet, and its magnetic end faces the back of the driving board. The first magnetic adsorption member can be a single magnet or multiple magnets, thereby improving the self-assembly efficiency of the LED device. For example: the first magnetic adsorption member is a row of magnets, or an array composed of multiple magnets. The magnetic end of the first magnetic adsorption member can be one pole of the magnet (such as the N pole or the S pole), or two poles or more poles of the magnet (when the magnet is a multi-pole magnet).

[0013] As a preferred solution of the present invention, in step S4, the first magnetic adsorption member is moved so that the magnetic end of the first magnetic adsorption member is translated relative to the back of the driving board (i.e., moves parallel to the back of the driving board), so that the LED device is adsorbed to different positions on the front of the driving board. Thus, the LED device is captured by the pads at different positions on the front of the driving board.

[0014] As another preferred solution of the present invention, in step S4, the driving board is moved so that the back of the driving board moves relative to the magnetic end of the first magnetic adsorption member, so that the LED device is adsorbed to different positions on the front of the driving board. Thus, the LED device is captured by the pads at different positions on the front of the driving board.

[0015] As a preferred solution of the present invention, the first magnetic adsorption member is a strip magnet having a long strip magnetic adsorption end parallel to the driving plate. The first magnetic adsorption member can be fixed on a certain movable mechanism (especially a translation mechanism) to change the relative position (such as vertical distance or horizontal position) between the first magnetic adsorption member and the driving plate. In this way, the first magnetic adsorption member can be swept relative to the driving plate to improve the self-assembly efficiency of the LED device.

[0016] As another preferred embodiment of the present invention, the first magnetic adsorption member adopts a first electromagnet; in step S4, the first electromagnet is energized to generate a magnetic field, and the magnetic field generates an adsorption force on the soft magnetic layer of a large number of the LED devices through the driving board, and these LED devices are adsorbed to the front of the driving board; in step S5, the first electromagnet is powered off, so that the LED devices not captured by the pads are released from the front of the driving board, and the LED devices not captured by the pads on the driving board are removed. The first magnetic adsorption member adopts the first electromagnet, and its equipment can reduce the mechanical structure and respond more quickly, so as to facilitate more efficient self-assembly of LED devices.

[0017] As a preferred solution of the present invention, in step S5, the magnetic end of the first magnetic adsorption member is moved away from the back of the driving board, so that the LED devices not captured by the pads are released from the front of the driving board, thereby removing the LED devices on the driving board that are not captured by the pads and leaving only the LED devices captured by the pads.

[0018] As a preferred solution of the present invention, in step S3, the front side of the driving board is facing downward, a collecting plate is provided below the front side of the driving board, and a large number of LED devices are applied between the front side of the driving board and the collecting plate; in step S4, the first magnetic adsorption component is located directly above the driving board and its magnetic end faces the back side of the driving board; in step S5, the magnetic end of the first magnetic adsorption component is moved away from the back side of the driving board, so that the LED devices not captured by the pad are released from the front side of the driving board by their own gravity and fall onto the collecting plate. The collecting plate can be a part of a container (such as the bottom) for storing LED devices and heating hot liquid. As a further preferred solution of the present invention, the steps S4-S5 are repeated, and the LED devices dropped on the collection board are re-adsorbed to the front of the driving board, so that more LED devices are captured by the pads. Thus, the LED devices that have not been captured have the possibility of being captured by the pads again; and by repeating the operations of steps S4-S5, the LED devices undergo multiple adsorption processes, so that each pad captures the LED device as much as possible, thereby improving the success rate of self-assembly of the LED devices and completing the full self-assembly of the LED devices.

[0019] As a further preferred solution of the present invention, before repeating the steps S4 to S5, the relative position between the driving board and the magnetic end of the first magnetic adsorption member is changed, so that the pads at different positions of the driving board can all capture the LED device, and in particular, all the pad positions of the first welding surface can be traversed so that all the pads of the driving board can capture the LED device.

[0020] As another preferred embodiment of the present invention, a collecting plate is provided on the front side of the driving board; in step S3, a large number of the LED devices are applied between the front side of the driving board and the collecting plate, and a second magnetic adsorption member is provided on the side of the collecting plate away from the driving board; in step S5, the magnetic end of the first magnetic adsorption member is moved away from the back side of the driving board, and the magnetic end of the second magnetic adsorption member is moved close to the back side of the collecting plate, so that the LED devices not captured by the soldering pad are released from the front side of the driving board and adsorbed onto the collecting plate by the second magnetic adsorption member. The collecting plate can be a part (such as the bottom) of a container for storing and heating hot liquid; the second magnetic adsorption member can adopt the same configuration as the first magnetic adsorption member, and the magnetic end of the first magnetic adsorption member and the magnetic end of the second magnetic adsorption member correspond to each other in shape and position, such as the first magnetic adsorption member and the second magnetic adsorption member are bar magnets of the same size and shape, and their magnetic ends are opposite. Therefore, through the adsorption of the second magnetic adsorption member, the LED devices on the driving board that are not captured by the soldering pad can be more thoroughly removed, leaving only the LED devices captured by the soldering pad.

[0021] As a further preferred embodiment of the present invention, the second magnetic adsorption member adopts a second electromagnet; in step S4, the second electromagnet is powered off; in step S5, the second electromagnet is powered on, so that the LED device not captured by the pad is released from the front of the driving board and adsorbed to the collection board by the second electromagnet. The second magnetic adsorption member adopts a second electromagnet, which can more conveniently and efficiently control its magnetic field, and can perform magnetic field switching at a high frequency to form magnetic force oscillation.

[0022] As a further preferred solution of the present invention, the steps S4-S5 are repeated, and the LED devices dropped on the collection board are re-adsorbed to the front of the driving board, so that more LED devices are captured by the pads. Thus, the LED devices on the collection board are re-adsorbed to the front of the driving board, and have the possibility of re-contacting and wetting the first metal of some pads with their welding surfaces, thereby being captured by the pads; and by repeating the operations of steps S4-S5, the LED devices undergo multiple adsorption processes, so that each pad captures the LED device as much as possible, completes the full self-assembly of the LED devices, and improves the success rate of the self-assembly of the LED devices.

[0023] As a further preferred solution of the present invention, before repeating the steps S4 to S5, the relative position between the driving board and the magnetic end of the first magnetic adsorption member is changed, so that the pads at different positions of the driving board can all capture the LED device, and in particular, all the pad positions of the first welding surface can be traversed so that all the pads of the driving board can capture the LED device.

[0024] As a preferred embodiment of the present invention, in the steps S2-S5, the driving board and the LED device are immersed in a hot liquid. The hot liquid can be a liquid with a high boiling point or vaporization temperature, such as paraffin oil or silicone oil, which is heated to a temperature exceeding the melting point of the first metal to maintain the temperature of the driving board. Thus, the hot liquid can not only be used to maintain the temperature of the LED device, but also slow down the speed of the LED device based on the resistance of the liquid, so as to avoid the LED device from being damaged by a high-speed collision with the driving board, the collecting plate or other LED devices under the action of the magnetic field.

[0025] As a further preferred embodiment of the present invention, the hot liquid is composed of molten rosin, which not only has a high vaporization temperature but also can remove the oxide layer on the first metal and the second metal, thereby improving their wettability.

[0026] Compared with the prior art, the present invention has the following advantages: The present invention can not only greatly improve the manufacturing efficiency of the LED array device and meet the requirements of mass production, but also effectively reduce the manufacturing cost of the LED array device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the structure of the driving board provided in step S1 in Example 1 of the preferred implementation manner of the present invention.

[0028] Figure 2 It is a schematic diagram of the structure of the LED device provided in step S3 of Example 1 of the preferred implementation manner of the present invention.

[0029] Figure 3 It is a schematic diagram of the process in which the LED device automatically forms a state with its light emitting surface facing outward when being captured by the solder pad in step S4 of Example 1 of the preferred implementation manner of the present invention.

[0030] Figure 4 It is a process schematic diagram of steps S3-S5 in Example 1 of the preferred implementation manner of the present invention.

[0031] Figure 5 It is a process schematic diagram of steps S3-S5 in Example 2 of the preferred implementation manner of the present invention.

[0032] Figure 6 It is a process schematic diagram of steps S3-S5 in Example 3 of the preferred implementation manner of the present invention.

[0033] Figure 7 It is a schematic diagram of the LED device and the soldering pad after being welded in Example 4 of the preferred implementation mode of the invention. DETAILED DESCRIPTION

[0034] Embodiment 1, as Figure 1-Figure 4 As shown, the self-assembly method of the LED display device comprises the following steps: S1, providing a driving board 1, and disposing a plurality of pads 11 on the front surface of the driving board 1, each pad 11 being provided with a first metal 12; S2, heating the temperature of the driving board 1 to a first temperature range higher than the melting point of the first metal 12, so that the first metal 12 on each pad 11 melts to form a liquid metal sticking point 120; S3, applying a large number of LED devices 2 provided with soft magnetic layers 20 to a side close to the front of the driving board 1, each LED device 2 includes a first electrode surface 21 and a second electrode surface 22 facing away from each other, the first electrode surface 21 is a non-metallic light emitting surface, and the second electrode surface 22 is a welding surface; S4. A first magnetic adsorption component 3 is arranged on a side close to the back of the driving board 1, and its magnetic end is close to the back of the driving board 1. The magnetic field generated by the first magnetic adsorption component 3 generates an adsorption force on the soft magnetic layer 20 of a large number of LED devices 2 through the driving board 1, and these LED devices 2 are adsorbed onto the front of the driving board 1, so that the welding surfaces of at least some of the LED devices 2 are infiltrated and adhered to the liquid metal sticking points 120 on some of the pads 11 to be captured by the pads 11, and the assembly state with the light emitting surface facing outward is automatically formed; S5, removing the LED devices 2 on the driving board 1 that are not captured by the soldering pads 11, leaving only the LED devices 2 captured by the soldering pads 11; S6, lowering the temperature of the driving board 1 to a second temperature range lower than the melting point of the first metal 12, so that the liquid metal sticking point 120 solidifies to form a weld between the soaked and adhered LED device 2 and the soldering pad 11, thereby manufacturing an LED display device.

[0035] In this embodiment, the driving board 1 is a printed circuit board with a display driving circuit (such as a static driving circuit, a dynamic driving circuit or an active driving circuit); the pads 11 are preset on the driving board 1 and form an array.

[0036] In this embodiment, the first metal 12 is a low melting point metal. For example, the first metal 12 is a tin-bismuth alloy with a melting point lower than 150°C, and the first temperature range can be set at 150-200°C. As a result, it can be heated in a short time and generally will not affect the structures such as the driving board 1 and the LED device 2. The first metal 12 can be pre-set on the pad 11 by printing, coating, plating, spraying, etc. The first metal 12 can be pre-melted and infiltrated and fully covered on the pad 11, or can be pre-set on the pad 11 in the form of a paste (such as solder paste), or attached to the pad 11 in a coating combined with a graphic method. The amount of the first metal 12 on the pad 11 is sufficient to form sufficient infiltration coverage on the pad 11 and the second electrode surface 22; and in order to prevent the melted first metal 12 from falling off its pad 11 and to ensure the alignment angle of the LED device 2, the amount of the first metal 12 cannot be too much, and the thickness or height of the first metal 12 does not exceed half the width of the pad 11.

[0037] In this embodiment, the LED device 2 is a vertical structure LED device, the light emitting surface and the welding surface of the LED device 2 correspond to the P pole and N pole (or N pole and P pole) of the LED respectively, and the welding surface is a metal (such as gold, silver, copper, zinc, iron) or alloy film surface that is easily wetted by the first metal 12. The LED device 2 is an LED device whose semiconductor layer 23 is GaAs, GaP, SiC, GaN (such as GaN blue light LED).

[0038] In order to prevent the soft magnetic layer 20 from affecting the light emission, in this embodiment, the soft magnetic layer 20 is arranged on the inner side of the second electrode surface 22 of the LED device 2. Specifically, the soft magnetic layer 20 is a soft magnetic metal (such as iron, nickel, manganese) film layer arranged under the second electrode surface 22 of the LED device 2, which has no magnetic field under normal conditions (soft magnetic metals are metals with low coercive force and high magnetic permeability, which are generally in a demagnetized state without a magnetic field), so that adjacent LED devices 2 will not attract each other and cause agglomeration. The structure of the vertical structure LED device 2 provided with the soft magnetic layer 20 and its manufacturing method can refer to the Chinese invention patent specification with the authorization announcement number CN108682725B and the patent name "A vertical structure LED device and its manufacturing method".

[0039] In this embodiment, in steps S2-S5, the driving board 1 and the LED device 2 are immersed in the hot liquid 50, which is composed of molten rosin. It is heated to a temperature exceeding the melting point of the first metal 12 to maintain the temperature of the driving board 1. The hot liquid 50 is composed of molten rosin, which not only has a high vaporization temperature, but also can remove the oxide layer on the first metal 12 and the second metal to improve its wettability. The hot liquid 50 can not only be used to maintain the temperature of the LED device 2, but also can slow down the speed of the LED device 2 based on the resistance of the liquid, so as to avoid the LED device 2 from forming a high-speed collision with the driving board 1, the collecting plate 4 or other LED devices 2 under the action of the magnetic field and causing damage.

[0040] In this embodiment, the first magnetic adsorption member 3 is a permanent magnet, and the magnetic ends of the first magnetic adsorption member 3 are the N pole and the S pole of the permanent magnet, thereby improving the self-assembly efficiency of the LED device 2.

[0041] In this embodiment, in step S3, the front side of the driving board 1 is facing downward and the back side is facing upward, a collecting plate 4 is provided below the front side of the driving board 1, and a large number of LED devices 2 are applied between the front side of the driving board 1 and the collecting plate 4; in step S4, the first magnetic adsorption component 3 is located directly above the driving board 1 and its magnetic end is facing the back side of the driving board 1; in step S5, the magnetic end of the first magnetic adsorption component 3 is moved away from the back side of the driving board 1, so that the LED devices 2 not captured by the soldering pad 11 are released from the front side of the driving board 1 due to their own gravity and fall onto the collecting plate 4; steps S4-S5 are repeated, the LED devices 2 that have fallen on the collecting plate 4 are re-adsorbed onto the front side of the driving board 1, and the relative positions of the driving board 1 and the magnetic ends of the first magnetic adsorption component 3 are changed, so that more LED devices 2 are captured by the soldering pad 11. The collecting plate 4 can be a part (such as the bottom) of a container for storing LED devices and serving as heating the hot liquid 50, and by repeating the operations of step S4-step S5, the LED device 2 undergoes multiple adsorption processes, so that each soldering pad 11 can capture the LED device 2 as much as possible, thereby improving the success rate of self-assembly of the LED device 2, completing the full self-assembly of the LED device 2, and allowing the soldering pads 11 at different positions of the driving board 1 to capture the LED device 2, especially traversing all the positions of the soldering pads 11 on the second electrode surface 22, so that all the soldering pads 11 of the driving board 1 capture the LED device 2.

[0042] Example 2, reference Figure 5 , when other parts are the same as those of the first embodiment, the difference is that: in step S3, a second magnetic adsorption component 5 is provided on the lower side of the collecting plate 4; in step S4, before the magnetic end of the first magnetic adsorption component 3 is brought close to the back side of the driving plate 1, the magnetic end of the second magnetic adsorption component 5 is moved away from the front side of the driving plate 1; in step S5, the magnetic end of the first magnetic adsorption component 3 is moved away from the back side of the driving plate 1, and the magnetic end of the second magnetic adsorption component 5 is brought close to the back side of the collecting plate 4, so that the LED devices 2 not captured by the soldering pad 11 are released from the front side of the driving plate 1 and adsorbed onto the collecting plate 4 by the second magnetic adsorption component 5; before performing step S6, steps S4-S5 are repeated, and the LED devices 2 dropped on the collecting plate 4 are re-adsorbed onto the front side of the driving plate 1, so that more LED devices 2 are captured by the soldering pad 11. As a result, the LED device 2 on the collecting plate 4 is re-adsorbed onto the front side of the driving plate 1, and has the possibility of re-contacting and being wetted with the first metal 12 of a part of the pads 11 with its welding surface, thereby being captured by the pads 11; and by repeating the operations of step S4-step S5, the LED device 2 undergoes multiple adsorption processes, so that each pad 11 captures the LED device 2 as much as possible, completing the full self-assembly of the LED device 2, and improving the success rate of the self-assembly of the LED device 2.

[0043] In this embodiment, the second magnetic adsorption member 5 uses the same permanent magnet as the first magnetic adsorption member 3, and the magnetic adsorption ends of the first magnetic adsorption member 3 and the second magnetic adsorption member 5 correspond to each other in shape and position. Therefore, the LED devices 2 on the driving board 1 that are not captured by the pad 11 can be more thoroughly removed through the adsorption of the second magnetic adsorption member 5, leaving only the LED devices 2 captured by the pad 11.

[0044] Example 3, reference Figure 6 , when other parts are the same as those of the second embodiment, the difference is that: in this embodiment, the first magnetic adsorption member 3 adopts the first electromagnet; in step S4, the first electromagnet is energized to generate a magnetic field, and the magnetic field generates an adsorption force on the soft magnetic layer 20 of a large number of LED devices 2 through the driving board 1, and these LED devices 2 are adsorbed to the front of the driving board 1; in step S5, the first electromagnet is powered off, so that the LED devices 2 not captured by the pad 11 are released from the front of the driving board 1, and the LED devices 2 not captured by the pad 11 on the driving board 1 are removed. The first magnetic adsorption member 3 adopts the first electromagnet, and its equipment can reduce the mechanical structure and respond more quickly, so as to facilitate more efficient self-assembly of the LED devices 2.

[0045] In this embodiment, the second magnetic adsorption member 5 is a second electromagnet; in step S4, the second electromagnet is powered off; in step S5, the second electromagnet is powered on, so that the LED device 2 not captured by the pad 11 is released from the front of the driving board 1 and adsorbed by the second electromagnet onto the collecting board 4. The second magnetic adsorption member 5 is a second electromagnet, which can more conveniently and efficiently control its magnetic field, and can perform magnetic field switching at a high frequency to form magnetic force oscillation.

[0046] Example 4, reference Figure 7 , when other parts are the same as those in Example 1, the difference is that: in this embodiment, the size of the pad 11 is larger than the size of the LED device 2; in the step S4, multiple LED devices 2 are adhered to one pad 11, and the number of LED devices 2 adhered to different pads 11 can be the same or different.

[0047] In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles of the patent concept of the present invention are included in the protection scope of the patent of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A self-assembly method for an LED display device, characterized in that The steps include: S1. Provide a driving board, and arrange a plurality of pads on the front side of the driving board, each pad being provided with a first metal; S2, heating the temperature of the driving board to a first temperature range higher than the melting point of the first metal, so that the first metal on each pad melts to form a liquid metal sticky point; S3, applying a large number of LED devices provided with a soft magnetic layer to a side close to the front of the driving board, each LED device including a first electrode surface and a second electrode surface facing away from each other, the first electrode surface being a non-metallic light emitting surface, and the second electrode surface being a welding surface; S4, a first magnetic adsorption component is arranged on a side close to the back of the driving board, and its magnetic end is close to the back of the driving board, the magnetic field generated by the first magnetic adsorption component generates an adsorption force on the soft magnetic layer of a large number of the LED devices through the driving board, and these LED devices are adsorbed to the front of the driving board, and the welding surfaces of at least some of the LED devices are infiltrated and adhered to the liquid metal sticking points on some of the pads so as to be captured by the pads, and the assembly state with the light emitting surface facing outward is automatically formed; S5, clear the LED devices on the driver board that are not captured by the pads; S6. Lowering the temperature of the driving board to a second temperature range lower than the melting point of the first metal, so that the liquid metal sticking point solidifies to form a weld between the wetted and adhered LED device and the soldering pad, thereby manufacturing the LED display device.

2. The self-assembly method of an LED display device according to claim 1, characterized in that: The soft magnetic layer is arranged on the inner side of the welding surface of the LED device.

3. The self-assembly method of an LED display device according to claim 1, characterized in that: In step S4, the relative position of the driving board and the magnetic end of the first magnetic adsorption component is changed so that the LED device is adsorbed to different positions on the front of the driving board.

4. The self-assembly method of an LED display device according to claim 3, characterized in that: Move the first magnetic adsorption member or the driving plate to move the magnetic end of the first magnetic adsorption member relative to the back side of the driving plate.

5. The self-assembly method of an LED display device according to claim 1, characterized in that: The first magnetic attraction member is a strip magnet having a long strip magnetic attraction end parallel to the driving plate.

6. The self-assembly method of an LED display device according to claim 1, characterized in that: The first magnetic adsorption component adopts a first electromagnet; in the step S4, the first electromagnet is energized to generate a magnetic field, and the magnetic field generates an adsorption force on the soft magnetic layers of a large number of LED devices through the driving board, and these LED devices are adsorbed to the front of the driving board; in the step S5, the first electromagnet is powered off, so that the LED devices not captured by the pads are released from the front of the driving board, and the LED devices on the driving board that are not captured by the pads are cleared.

7. The self-assembly method of an LED display device according to claim 1, characterized in that: In the step S5, the magnetic end of the first magnetic attraction member is moved away from the back side of the driving board, so that the LED devices not captured by the pads are released from the front side of the driving board.

8. The self-assembly method of an LED display device according to claim 1, characterized in that: In the step S3, the front side of the driving board is facing downward, a collecting plate is provided below the front side of the driving board, and a large number of LED devices are applied between the front side of the driving board and the collecting plate; in the step S4, the first magnetic adsorption component is located directly above the driving board and its magnetic end is facing the back side of the driving board; in the step S5, the magnetic end of the first magnetic adsorption component is moved away from the back side of the driving board, so that the LED devices not captured by the soldering pad are released from the front side of the driving board due to their own gravity and fall onto the collecting plate.

9. The self-assembly method of an LED display device according to claim 8, characterized in that: Repeat the steps S4 to S5 to re-adsorb the LED devices that have fallen onto the collecting plate onto the front side of the driving plate, so that more LED devices are captured by the soldering pads.

10. The self-assembly method of an LED display device according to claim 1, characterized in that: A collecting plate is provided on the front side of the driving board; in step S3, a large number of the LED devices are applied between the front side of the driving board and the collecting plate, and a second magnetic adsorption component is provided on the side of the collecting plate away from the driving board; in step S5, the magnetic end of the first magnetic adsorption component is moved away from the back side of the driving board, and the magnetic end of the second magnetic adsorption component is moved close to the back side of the collecting plate, so that the LED devices not captured by the soldering pad are released from the front side of the driving board and adsorbed onto the collecting plate by the second magnetic adsorption component.

11. The self-assembly method of an LED display device according to claim 10, characterized in that: The second magnetic adsorption member adopts a second electromagnet; in the step S4, the second electromagnet is powered off; in the step S5, the second electromagnet is also powered on, so that the LED devices not captured by the pad are released from the front of the driving board and adsorbed onto the collection board by the second electromagnet.

12. The self-assembly method of an LED display device according to claim 10, characterized in that: Repeat the steps S4 to S5 to re-adsorb the LED devices that have fallen onto the collecting plate onto the front side of the driving plate, so that more LED devices are captured by the soldering pads.

13. The self-assembly method of an LED display device according to claim 1, characterized in that: In the steps S2-S5, the driving board and the LED device are immersed in hot liquid.

14. The self-assembly method of an LED display device according to claim 13, characterized in that: The hot liquid is composed of molten rosin.

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