Chip transfer assembly, manufacturing method thereof, chip transfer method and system

Abstract

The present application relates to a kind of chip transfer assembly and its manufacturing method, chip transfer method and system, including substrate, several to be transferred light emitting chips on the front surface of substrate, photoelectric reaction layer is equipped on the outer surface of light emitting chip, it occurs photoelectric effect to generate an acting force to offset the gravity of light emitting chip under laser irradiation;In the process of transferring light emitting chip from substrate to circuit board, by laser beam irradiation to photoelectric reaction layer on light emitting chip, it is peeled off from substrate, its gravity and acting force cancel out and suspend in the air above the die-bonding area of its alignment circuit board, after laser beam is turned off, so that light emitting chip falls on the die-bonding area of its alignment under the action of its gravity;Light emitting chip can be suspended in the air above the die-bonding area on circuit board during transfer process, directly transferred to circuit board after laser beam is turned off, improve transfer efficiency, and reduce transfer cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of light emitting chips, in particular to a chip transfer assembly and a manufacturing method thereof, a chip transfer method and system. BACKGROUND

[0002] Micro LED (Light Emitting Diode) is a new generation of display technology. Compared with the existing liquid crystal display, it has higher photoelectric efficiency, higher brightness, higher contrast, and lower power consumption, and can also realize flexible display by combining with flexible panels.

[0003] Mass transfer is the core technology of Micro LED, and directly transferring Micro LED chips from a growth substrate to a display backplane is recognized as the final mass transfer technology. The mass transfer technology currently adopted needs to transfer Micro LED chips from a growth substrate to a temporary substrate, and then selectively pick up Micro LED chips from the temporary substrate by a transfer substrate and transfer them to the display backplane. This process needs to make a specific first adhesive layer and a second adhesive layer on the temporary substrate and the transfer substrate respectively, and needs to transfer the light emitting chips from the growth substrate to the temporary substrate and the transfer substrate in turn, and then from the transfer substrate to the display backplane. The transfer process is complicated and the transfer efficiency is low; two kinds of adhesives need to be selected to make the first adhesive layer and the second adhesive layer respectively, and the viscosity of the first adhesive layer needs to be lower than that of the second adhesive layer, which is difficult to find suitable materials and the manufacturing cost is high.

[0004] Therefore, how to improve the transfer efficiency of LED chips and reduce the transfer cost is a problem to be solved. SUMMARY

[0005] In view of the deficiencies of the above related technologies, the purpose of the present application is to provide a chip transfer method, aiming to solve the problem of how to improve the transfer efficiency of LED chips and reduce the risk of damage to LED chips in the transfer process in the related technologies.

[0006] The present application provides a chip transfer assembly, comprising:

[0007] a substrate;

[0008] a plurality of light emitting chips to be transferred arranged on the front surface of the substrate;

[0009] a photoelectric reaction layer formed on the outer surface of each light emitting chip, the photoelectric reaction layer being used to generate a force counteracting the gravity of the light emitting chip by photoelectric effect under laser irradiation in the process of transferring the light emitting chip from the substrate to a circuit board.

[0010] The chip transfer assembly provided by the application has the photoelectric reaction layer formed on the outer surface of the light emitting chip on the substrate, and the photoelectric reaction layer is used to generate a force to offset the gravity of the light emitting chip when the light emitting chip is transferred from the substrate to the circuit board. When the light emitting chip is transferred to the circuit board, the photoelectric reaction layer on the light emitting chip is irradiated by a laser beam, and the photoelectric reaction layer generates a force to offset the gravity of the light emitting chip, so that the light emitting chip is suspended in the air. After the laser beam is turned off, the light emitting chip falls onto the circuit board under the action of gravity, and then the light emitting chip is bonded to the circuit board. In the chip transfer process, the light emitting chip can be suspended above the die bonding area on the circuit board, and then transferred to the circuit board after the laser beam is turned off, so that the transfer efficiency is improved, the transfer cost is reduced, and the risk of damage to the light emitting chip in the transfer process is reduced.

[0011] Based on the same inventive concept, the application also provides a manufacturing method of a chip transfer assembly, comprising:

[0012] The light emitting chips to be transferred are arranged on the front surface of the substrate;

[0013] The photoelectric reaction layer is plated on the outer surface of each light emitting chip.

[0014] The photoelectric reaction layer is plated on the outer surface of each light emitting chip.

[0015] Based on the same inventive concept, the application also provides a chip transfer system, comprising: a circuit board, a first laser device and the chip transfer assembly as described above; the circuit board is arranged between the first laser device and the chip transfer assembly, and the light emitting chips to be transferred on the substrate are arranged in alignment with the die bonding area on the circuit board.

[0016] The first laser beam generated by the first laser device transmits through the circuit board and irradiates the light emitting chip to be transferred on the substrate, the photoelectric reaction layer on the outer surface of the light emitting chip generates a photoelectric effect under the irradiation of the first laser beam to generate an action force to counteract the gravity of the light emitting chip, after the light emitting chip is peeled off from the substrate, the gravity and the action force counteract each other and the light emitting chip is suspended above the die bonding area in the corresponding position, and the light emitting chip falls onto the die bonding area in the corresponding position when the action force disappears.

[0017] The photoelectric reaction layer is used to generate a photoelectric effect under the irradiation of laser to generate an action force to counteract the gravity of the light emitting chip in the process of transferring the light emitting chip from the substrate to the circuit board.

[0018] In the chip transfer system, the first laser beam generated by the first laser device irradiates the photoelectric reaction layer on the light emitting chip after the light emitting chip is peeled off from the substrate, the photoelectric reaction layer generates a photoelectric effect under the irradiation of the first laser beam to generate an action force to counteract the gravity of the light emitting chip, after the light emitting chip is peeled off from the substrate, the gravity and the action force counteract each other and the light emitting chip is suspended above the die bonding area on the circuit board in the corresponding position, and the light emitting chip falls onto the die bonding area in the corresponding position when the action force disappears, in the process of transferring the light emitting chip, the light emitting chip is suspended above the die bonding area on the circuit board under the action of the laser beam, and the light emitting chip falls onto the circuit board under the action of the gravity after the laser beam is turned off, so that the light emitting chip is directly transferred to the circuit board for simultaneous bonding, the transfer efficiency is improved, and the transfer cost is reduced.

[0019] Based on the same inventive concept, the application also provides a chip transfer method, comprising:

[0020] Peeling off the light emitting chip to be transferred on the substrate from the substrate;

[0021] The first laser beam generated by the first laser device transmits through the circuit board and irradiates the photoelectric reaction layer on the outer surface of the light emitting chip, the photoelectric reaction layer generates a photoelectric effect under the irradiation of the first laser beam to generate an action force to counteract the gravity of the light emitting chip, after the light emitting chip is peeled off from the substrate, the gravity and the action force counteract each other and the light emitting chip is suspended above the die bonding area in the corresponding position;

[0022] Turning off the first laser device, so that the light emitting chip falls onto the die bonding area in the corresponding position under the action of the gravity.

[0023] Through the chip transfer method provided by the application, in the process of transferring the light-emitting chip to the circuit board, the light-emitting chip is separated from the substrate, and then is made to float above the die bonding area of the circuit board under the action of the laser beam, and then the laser beam is turned off, so that the light-emitting chip falls onto the circuit board under the action of its own gravity, thereby directly transferring the light-emitting chip to the circuit board, the transfer process is simple, the transfer speed is fast, and the transfer efficiency is improved, and the risk of damage of the light-emitting chip due to contact with other devices in the transfer process is reduced through the floating transfer. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A schematic diagram of transferring three colors of Micro LED chips from a substrate to a circuit board in the related art;

[0025] Figure 2-1 A structure schematic of a chip transfer assembly provided by an embodiment of the application Figure 1 ;

[0026] Figure 2-2 A structure schematic of a chip transfer assembly provided by an embodiment of the application

[0027] Figure 2-3 A structure schematic of a chip transfer assembly provided by an embodiment of the application Figure 3 ;

[0028] Figure 2-4 A structure schematic of a chip transfer assembly provided by an embodiment of the application Figure 4 ;

[0029] Figure 3 A flowchart of a manufacturing method of a chip transfer assembly provided by an embodiment of the application

[0030] Figure 4 A schematic diagram of a light-emitting chip plated with a photoelectric reaction layer floating in the air under laser irradiation provided by an embodiment of the application

[0031] Figure 5-1 A structure schematic of a chip transfer system provided by another optional embodiment of the application Figure 1 ;

[0032] Figure 5-2 A structure schematic of a chip transfer system provided by another optional embodiment of the application

[0033] Figure 5-3 A structure schematic of a chip transfer system provided by another optional embodiment of the application Figure 3 ;

[0034] Figure 6-1 A structure schematic of a transmission channel module provided by another optional embodiment of the application Figure 1 ;

[0035] Figure 6-2 Structure diagram of the transmission channel module provided for another optional embodiment of the present application;

[0036] Figure 7 Flow chart of the chip transfer method provided for another optional embodiment of the present application;

[0037] Figure 8 Flow chart of another chip transfer method provided for another optional embodiment of the present application;

[0038] Figure 9-1 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application Figure 1 ;

[0039] Figure 9-2 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application

[0040] Figure 9-3 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application Figure 3 ;

[0041] Figure 9-4 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application Figure 4 ;

[0042] Figure 9-5 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application

[0043] Figure 9-6 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application

[0044] Figure 9-7 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application Figure 7 ;

[0045] Figure 9-8 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application Figure 8 ;

[0046] Figure 9-9 Schematic diagram of the chip transfer process provided for another optional embodiment of the present application

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] 101-Red LED growth substrate, 102-Green LED growth substrate, 103-Blue LED growth substrate, 104-Display backplate, A-First laser beam, B-Second laser beam, 20-Substrate, 21-Light-emitting chip, 22-First photoelectric reaction sublayer, 23-Second photoelectric reaction sublayer, 24-Third photoelectric reaction sublayer, 40-Photoelectric reaction layer, 50-Chip transfer assembly, 51-Circuit board, 52-First laser device, 53-Transmission channel module, 531-Transmission channel, 54-Second laser device, 601-Support plate, 602-Column channel. Detailed Implementation

[0049] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0051] In Micro LED display technology, see Figure 1 As shown, it is necessary to transfer the red Micro LED chip on the red LED growth substrate 101, the blue Micro LED chip on the blue LED growth substrate 103, and the green Micro LED chip on the green LED growth substrate 102 from their respective growth substrates to the display backplane 104. For example, the red Micro LED chip is first transferred to the display backplane for bonding, then the green Micro LED chip is transferred to the circuit board for bonding, and then the blue Micro LED chip is transferred to the display backplane for bonding.

[0052] During the chip transfer process described above, red Micro LED chips, blue Micro LED chips, and green Micro LED chips need to be transferred from their respective substrates to the display backplane in sequence. This involves multiple transfers and high transfer speeds. When bonding the transferred Micro LED chips to the circuit board, the multiple bonding processes can lead to the risk of oxidation of the bonding materials.

[0053] Therefore, this application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0054] The embodiment provides a chip transfer assembly, comprising:

[0055] a substrate;

[0056] a plurality of light emitting chips to be transferred arranged on a front surface of the substrate;

[0057] a photoelectric reaction layer formed on an outer surface of each light emitting chip, the photoelectric reaction layer being used to generate a photoelectric effect under laser irradiation to generate an action force counteracting a gravity of the light emitting chip during a process of transferring the light emitting chip from the substrate to a circuit board.

[0058] In the embodiment, the substrate includes but is not limited to a growth substrate, for example, a growth substrate used for growing the light emitting chip, and can also be a transfer substrate or a temporary substrate used for transferring the chip during the chip transfer process. The light emitting chip is grown on the substrate, or the light emitting chip is adhered to the substrate by a bonding adhesive.

[0059] It should be understood that the light emitting chip in the embodiment can be a micro light emitting chip, for example, can include but is not limited to at least one of a Mini LED chip and a Micro LED chip, and can also be a general light emitting chip with a size greater than or equal to 200 microns. And the light emitting chip in the embodiment can be a normal light emitting chip, a flip light emitting chip or a vertical light emitting chip, which can be flexibly set according to application requirements. In the embodiment, the light emitting chip on the substrate is bonded to the substrate.

[0060] In the embodiment, the photoelectric reaction layer is a graphene layer. It should be understood that the photoelectric reaction layer in the embodiment includes but is not limited to a graphene layer, and any other material that can generate a photoelectric effect under laser irradiation to generate an action force in the same direction as the laser irradiation direction to counteract its own gravity can be used, and a suitable material can be flexibly selected as the photoelectric reaction layer according to application requirements.

[0061] In the embodiment, the top surface of the light emitting chip is bonded to the front surface of the substrate, the bottom surface of the light emitting chip is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. The photoelectric reaction layer formed on the outer surface of each light emitting chip includes at least one of the following:

[0062] a first photoelectric reaction sub-layer arranged on at least two opposite side surfaces of the light emitting chip;

[0063] a second photoelectric reaction sub-layer arranged on the bottom surface of the light emitting chip;

[0064] a third photoelectric reaction sub-layer arranged on an outer surface of an electrode of the light emitting chip when the electrode is arranged on the bottom surface.

[0065] For the convenience of understanding, the chip transfer assembly provided by the embodiment is exemplarily illustrated below in combination with the accompanying drawings as examples.

[0066] An example of the chip transfer assembly of the embodiment is shown in Figure 2-1 The chip transfer assembly includes a substrate 20, a plurality of light emitting chips 21 to be transferred arranged on the front surface of the substrate 20, the top surface of the light emitting chip 21 adheres to the front surface of the substrate, the bottom surface of the light emitting chip 21 is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. In this example, the electrodes of the light emitting chip 21 are arranged on the bottom surface, and a first photoelectric reaction sub-layer 22 is arranged on at least two opposite side surfaces of the light emitting chip 21.

[0067] Another example of the chip transfer assembly of the embodiment is shown in Figure 2-2 The chip transfer assembly includes a substrate 20, a plurality of light emitting chips 21 to be transferred arranged on the front surface of the substrate 20, the top surface of the light emitting chip 21 adheres to the front surface of the substrate, the bottom surface of the light emitting chip 21 is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. In this example, the electrodes of the light emitting chip 21 are arranged on the bottom surface, and a second photoelectric reaction sub-layer 23 is arranged on the bottom surface of the light emitting chip 21.

[0068] Another example of the chip transfer assembly of the embodiment is shown in Figure 2-3 The chip transfer assembly includes a substrate 20, a plurality of light emitting chips 21 to be transferred arranged on the front surface of the substrate 20, the top surface of the light emitting chip 21 adheres to the front surface of the substrate, the bottom surface of the light emitting chip 21 is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. In this example, the electrodes of the light emitting chip 21 are arranged on the bottom surface, and a third photoelectric reaction sub-layer 24 is arranged on the outer surface of the electrodes of the light emitting chip 21.

[0069] Another example of the chip transfer assembly of the embodiment is shown in Figure 2-4 The chip transfer assembly includes a substrate 20, a plurality of light emitting chips 21 to be transferred arranged on the front surface of the substrate 20, the top surface of the light emitting chip 21 adheres to the front surface of the substrate, the bottom surface of the light emitting chip 21 is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. In this example, the electrodes of the light emitting chip 21 are arranged on the bottom surface, and a second photoelectric reaction sub-layer 23 is arranged on the bottom surface of the light emitting chip 21 and a third photoelectric reaction sub-layer 24 is arranged on the outer surface of the electrodes.

[0070] It should be understood that in the embodiment, the photoelectric reaction layer arranged on the outer surface of the light emitting chip includes but is not limited to the above-mentioned several examples, and can also be a combination of the above-mentioned several examples, which will not be described one by one here.

[0071] It can be seen that the chip transfer assembly provided by the application has the photoelectric reaction layer formed on the outer surface of the light emitting chip to be transferred on the substrate, and the photoelectric reaction layer is used to generate a force to offset the gravity of the light emitting chip during the process of transferring the light emitting chip from the substrate to the circuit board. During the process of transferring the light emitting chip to the circuit board, the photoelectric reaction layer on the light emitting chip irradiated by the laser beam generates a force to offset the gravity of the light emitting chip, so that the light emitting chip is suspended in the air. After the laser beam is turned off, the light emitting chip to be transferred falls onto the circuit board under the action of gravity, and then the light emitting chip is bonded to the circuit board. During the chip transfer process, the light emitting chip can be suspended above the die bonding area on the circuit board, and then transferred to the circuit board after the laser beam is turned off, thereby improving the transfer efficiency and reducing the transfer cost, and reducing the risk of damage to the light emitting chip during the transfer process.

[0072] Another optional embodiment:

[0073] For the convenience of understanding, the following describes an example of the manufacturing method of the chip transfer assembly in the embodiment, which is shown in Figure 3 The manufacturing method includes but is not limited to:

[0074] S301: A plurality of light emitting chips to be transferred are arranged on the front surface of the substrate.

[0075] In the embodiment, the way of arranging the plurality of light emitting chips to be transferred on the front surface of the substrate includes but is not limited to growing the light emitting chips on the substrate, or adhering the light emitting chips to the substrate by adhesive material.

[0076] S302: A photoelectric reaction layer is plated on the outer surface of each light emitting chip.

[0077] In the embodiment, the photoelectric reaction layer plated on the outer surface of each light emitting chip can be plated on the outer surface of each light emitting chip by electroplating process, or plated on the outer surface of each light emitting chip by chemical plating process. Of course, the embodiment includes but is not limited to the electroplating and chemical plating processes, and the specific plating process can be flexibly selected according to application requirements.

[0078] In the embodiment, the top surface of the light emitting chip is attached to the front surface of the substrate, the bottom surface of the light emitting chip is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface. The photoelectric reaction layer formed on the outer surface of each light emitting chip includes at least one of the following:

[0079] The first photoelectric reaction sub-layer is arranged on at least two opposite side surfaces of the light emitting chip;

[0080] The second photoelectric reaction sub-layer is arranged on the bottom surface of the light emitting chip;

[0081] The third photoelectric reaction sub-layer is arranged on the outer surface of the electrode of the light emitting chip.

[0082] The specific position of the photoelectric reaction layer arranged on the outer surface of the light emitting chip can refer to the above embodiment, which will not be described here.

[0083] The manufacturing method of the chip transfer assembly provided in the embodiment is used for plating a photoelectric reaction layer on the outer surface of the light emitting chip on the substrate. The photoelectric reaction layer is used for generating an action force that offsets the gravity of the light emitting chip in the process of transferring the light emitting chip from the substrate to the circuit board. In the process of transferring the light emitting chip to the circuit board, the photoelectric reaction layer on the light emitting chip that has been separated from the substrate is irradiated by a laser beam. The photoelectric reaction layer generates an action force that offsets the gravity of the light emitting chip, so that the light emitting chip is suspended in the air. When the light emitting chip to be transferred is completely separated from the substrate, the laser beam is turned off. The light emitting chip to be transferred falls to the circuit board under the action of gravity. Then, the light emitting chip is bonded to the circuit board. The transfer efficiency is improved, the transfer cost is reduced, and the risk of damage to the light emitting chip in the transfer process is reduced.

[0084] Yet another optional embodiment:

[0085] The embodiment provides a chip transfer system, which comprises a circuit board, a first laser device and a chip transfer assembly as above. The circuit board is arranged between the first laser device and the chip transfer assembly. The light emitting chip to be transferred on the substrate is arranged in position with a die bonding area on the circuit board. The first laser beam generated by the first laser device passes through the circuit board and irradiates the light emitting chip to be transferred on the substrate. The photoelectric reaction layer on the outer surface of the light emitting chip generates photoelectric effect under the irradiation of the first laser beam to generate an action force that offsets the gravity of the light emitting chip. After the light emitting chip is separated from the substrate, the gravity and the action force are offset, so that the light emitting chip is suspended above the die bonding area in position, and falls to the die bonding area in position when the action force disappears. The photoelectric reaction layer is used for generating photoelectric effect under the irradiation of a laser beam to generate an action force that offsets the gravity of the light emitting chip in the process of transferring the light emitting chip from the substrate to the circuit board.

[0086] In the embodiment, after the light emitting chip is separated from the substrate, the photoelectric reaction layer arranged on the light emitting chip generates photoelectric effect under the irradiation of the first laser beam generated by the first laser device. The photoelectric reaction layer absorbs light energy and converts the light energy into kinetic energy, so that the photoelectric reaction layer is subjected to an action force in the upward direction, so that the light emitting chip is suspended in the air. Referring to Figure 4As shown, the first laser beam A irradiates the photoelectric reaction layer 40 arranged on the outer surface of the light emitting chip 21, and the photoelectric reaction layer 31 generates an upward force F through photoelectric effect. When the upward force F and the gravity G of the light emitting chip 21 reach a balance, the light emitting chip will be suspended in the air. It can be understood that in the embodiment, the suspended position of the light emitting chip can be adjusted by adjusting the energy of the first laser beam. The greater the energy of the first laser beam, the greater the upward force generated by the photoelectric reaction layer.

[0087] In the embodiment, the first laser device emits a planar first laser beam, so that each light emitting chip suspended above the die bonding area of the circuit board after being separated from the substrate is uniformly stressed. The circuit board in the embodiment can be a display backplane or various circuit boards for lighting, and can be a flexible circuit board or a rigid circuit board. When it is a display backplane, the display backplane can be, but is not limited to, a glass backplane or a PCB board.

[0088] It should be understood that in the embodiment, the circuit board is required to be light-transmitting, so that the laser can transmit through the circuit board to irradiate the photoelectric reaction layer on the light emitting chip.

[0089] For ease of understanding, the chip transfer system provided in the embodiment will be exemplarily described below with reference to the accompanying drawings as examples.

[0090] An example of a chip transfer system is shown in Figure 5-1 As shown, it includes a circuit board 51, a first laser device 52, and a chip transfer assembly 50 as in the above embodiments, the circuit board 51 is arranged between the first laser device 52 and the chip transfer assembly 50, and the light emitting chip to be transferred on the substrate of the chip transfer assembly 50 is arranged in alignment with the die bonding area 511 on the circuit board 51. The first laser device 52 can generate a planar first laser beam A, and the first laser beam A transmits through the circuit board 51 to irradiate the light emitting chip on the substrate.

[0091] In some examples of the embodiment, referring to Figure 5-2 As shown, the chip transfer system further includes a transmission channel module 53, which is arranged between the substrate and the circuit board 51 and has a plurality of transmission channels 531 in alignment with each die bonding area on the circuit board and each light emitting chip corresponding to each die bonding area, respectively. The transmission channel 531 in the embodiment ensures that the light emitting chip will not fly or tilt when it is suspended in the air due to uneven stress, and ensures that the light emitting chip can accurately fall into the die bonding area on the circuit board when it is separated from the substrate.

[0092] For ease of understanding, the transmission channel module provided in the embodiment will be exemplarily described below with reference to the accompanying drawings as examples.

[0093] An example of a transmission channel module is shown in Fig. 5. Figure 6-1 As shown in Fig. 5, the transmission channel module 53 has a plurality of transmission channels 531 which are respectively aligned with and communicated with each die bonding area on the circuit board and each light emitting chip corresponding to the die bonding area. It should be understood that the shape of the transmission channel should match the shape of the light emitting chip. In this example, the shape of the transmission channel 531 is rectangular.

[0094] Another example of a transmission channel module is shown in Fig. 6. Figure 6-2 As shown in Fig. 6, the transmission channel module 53 includes a support plate 601, and the support plate 601 is provided with a plurality of columnar channels 602 which are respectively aligned with and communicated with each die bonding area on the circuit board and each light emitting chip corresponding to the die bonding area. It should be understood that the shape of the columnar channel should match the shape of the light emitting chip. In this example, the shape of the columnar channel is rectangular.

[0095] In some examples of the embodiment, a chip transfer system is shown in Fig. 4. Figure 5-3 As shown in Fig. 4, the chip transfer system further includes a second laser device 54, and a second laser beam B emitted by the second laser device 54 irradiates the light emitting chip to be transferred on the substrate to make the light emitting chip peel off from the growth substrate.

[0096] In the embodiment, the light emitting chip to be transferred on the substrate can be peeled off from the substrate by the laser beam emitted by the second laser device, and can also be peeled off from the substrate by other ways. The method of peeling off the chip from the substrate can be flexibly selected according to the application requirements.

[0097] The chip transfer system provided by the embodiment is characterized in that the photoelectric reaction layer on the light emitting chip peeled off from the substrate is irradiated by the first laser beam generated by the first laser device, the photoelectric reaction layer generates an action force to offset the gravity of the light emitting chip by photoelectric effect under the irradiation of the first laser beam. After the light emitting chip is peeled off from the substrate, the gravity of the light emitting chip and the action force offset each other to make the light emitting chip suspend above the die bonding area on the circuit board which is aligned with the light emitting chip, and the light emitting chip falls onto the die bonding area which is aligned with the light emitting chip when the action force disappears. In the process of transferring the light emitting chip, the light emitting chip is made to suspend above the die bonding area on the circuit board under the action of the laser beam, and the light emitting chip is made to fall onto the circuit board under the action of the gravity of the light emitting chip after the laser beam is turned off, so that the light emitting chip is directly transferred to the circuit board for simultaneous bonding. Therefore, the transfer efficiency is improved, and the transfer cost is reduced.

[0098] Yet another optional embodiment is shown in Fig. 7.

[0099] For the convenience of understanding, the method of transferring the chip using the chip transfer system described above is explained in the following embodiment, which is shown in Fig. 8. Figure 7 As shown in Fig. 8, the method includes but is not limited to:

[0100] S701: peeling the light emitting chip to be transferred on the substrate from the substrate.

[0101] In the embodiment, the light emitting chip can be peeled from the substrate by the method of laser peeling, or peeled from the substrate by other ways. When the chip transfer system shown in FIG. 1 is adopted, the light emitting chip to be transferred on the substrate can be peeled from the substrate by the laser beam emitted by the second laser device. Figure 5-3

[0102] In the embodiment, the substrate includes a first substrate, a second substrate and a third substrate, and the light emitting chip includes a first light emitting chip grown on the first substrate, a second light emitting chip grown on the second substrate and a third light emitting chip grown on the third substrate. In step S701, the light emitting chip to be transferred on the substrate is peeled from the substrate, including:

[0103] The first light emitting chip is peeled from the first substrate, the second light emitting chip is peeled from the second substrate, and the third light emitting chip is peeled from the third substrate.

[0104] S702: the first laser device generates a laser beam to irradiate the photoelectric reaction layer on the light emitting chip peeled from the substrate, and the photoelectric reaction layer generates a force to counteract the gravity of the light emitting chip to make the light emitting chip suspended above the corresponding die bonding area.

[0105] The first laser beam generated by the first laser device transmits through the circuit board to irradiate the photoelectric reaction layer on the outer surface of the light emitting chip, and the photoelectric reaction layer generates a force to counteract the gravity of the light emitting chip to make the light emitting chip suspended above the corresponding die bonding area.

[0106] S703: turning off the first laser device to make the light emitting chip fall onto the corresponding die bonding area under the action of its own gravity.

[0107] After all the first light emitting chip, the second light emitting chip and the third light emitting chip to be transferred are peeled from the corresponding substrate and suspended above the corresponding die bonding area, the first laser device is turned off to make the first light emitting chip, the second light emitting chip and the third light emitting chip fall onto the corresponding die bonding area synchronously. Then, the first light emitting chip, the second light emitting chip and the third light emitting chip are bonded with the die bonding area.

[0108] ​In the embodiment, when at least one of the first photoelectric reaction sub-layer arranged on at least two opposite sides of the light-emitting chip and the second photoelectric reaction sub-layer arranged on the bottom surface of the light-emitting chip is present, after the first light-emitting chip, the second light-emitting chip, the third light-emitting chip and the die bonding area are bonded, at least one of the first photoelectric reaction sub-layer and the second photoelectric reaction sub-layer is removed. In the embodiment, the first photoelectric reaction sub-layer and the second photoelectric reaction sub-layer can be removed by chemical cleaning, for example, using dimethylformamide (DMF) to clean the first photoelectric reaction sub-layer and the second photoelectric reaction sub-layer.

[0109] For ease of understanding, the above-described Figure 5-3 The method of transferring the chip by the chip transfer system provided is exemplarily described, in which graphene is used as the photoelectric reaction layer, the light-emitting chip is a Micro LED chip, a graphene layer is formed by plating a graphene material on the surface of the Micro LED chip by electroplating, and the chip transfer process is described with reference to Figure 8 and Figures 9-1 to 9-9 which include but are not limited to:

[0110] S801: The substrate on which the red Micro LED chips are grown is attached to the first end of the transmission channel module, and the circuit board is attached to the other end of the transmission channel module.

[0111] In the embodiment, the transmission channel module 53 is provided with a plurality of transmission channels 531 which are respectively aligned with and communicated with each of the die bonding areas on the circuit board and each of the light-emitting chips corresponding to the die bonding areas, as shown in Figure 9-1 The substrate is attached to the first end of the transmission channel module 53, and the red Micro LED chips are inserted into the transmission channels 531. The circuit board 51 is attached to the other end of the transmission channel module, and the die bonding areas on the circuit board 51 are inserted into the transmission channels 531.

[0112] S802: Turn on the first laser device and the second laser device, and separate the red Micro LED chip to be transferred from the substrate, and the separated red Micro LED chip is suspended in the transmission channel under the action of the first laser beam.

[0113] Referring to Figure 9-2The first laser device 52 and the second laser device 54 are turned on. The second laser device 54 emits a second laser beam B to selectively detach the red Micro LED chip to be transferred from its substrate. When the downward force of gravity on the detached red Micro LED chip is balanced by the upward force exerted by the first laser beam A irradiating the graphene layer on the red Micro LED chip, the red Micro LED chip is suspended in the transmission channel 531. It should be understood that in this embodiment, when the red Micro LED chip is at the first end of the transmission channel module 53, its gravity is greater than the force exerted by the first laser beam, causing it to fall from the substrate to the second end of the transmission channel module. During the fall to the second end of the transmission channel module, the force it experiences increases, and when it reaches equilibrium with its gravity, it is suspended in the transmission channel 531.

[0114] S803: Turn off the second laser device and replace the substrate of the red Micro LED chip with the substrate of the green Micro LED chip.

[0115] See Figure 9-3 As shown, after the red Micro LED chip to be transferred is selectively detached from its substrate by the second laser beam B, the second laser device 54 is turned off, and the substrate of the red Micro LED chip is removed. The substrate with the green Micro LED chip is then attached to the first end of the transmission module 53, so that the green Micro LED chip is inserted into the transmission channel 531.

[0116] S804: Turn on the second laser device to detach the green Micro LED chip to be transferred from the substrate. After detachment, the green Micro LED chip is suspended in the transmission channel under the action of the first laser beam.

[0117] See Figure 9-4 Then, the second laser device is turned on again, and the green Micro LED chip to be transferred is selectively detached from its substrate by the second laser beam B. When the downward gravity on the detached green Micro LED chip is balanced by the upward force on the graphene layer on the green Micro LED chip irradiated by the first laser beam A, the green Micro LED chip is suspended in the transmission channel.

[0118] S805: Turn off the second laser device and replace the substrate of the green Micro LED chip with the substrate of the blue Micro LED chip.

[0119] See Figure 9-5As shown, the second laser device is turned off, and the substrate of the green Micro LED chip is replaced by the substrate of the blue Micro LED chip.

[0120] S806: The second laser device is turned on, and the blue Micro LED chip to be transferred is detached from the substrate, and the detached blue Micro LED chip is suspended in the transmission channel under the action of the first laser beam.

[0121] Referring to Figure 9-6 As shown, the second laser device 54 is turned on again, and the blue Micro LED chip to be transferred is detached from the substrate by the second laser beam B, and the detached blue Micro LED chip is suspended in the transmission channel under the action of the first laser beam A.

[0122] S807: The second laser device is turned off and removed, and the substrate is taken away.

[0123] Referring to Figure 9-7 As shown, at this time, the red Micro LED chip, the green Micro LED chip, and the blue Micro LED chip to be transferred are detached from their corresponding substrates by the first laser beam, and the red Micro LED chip, the green Micro LED chip, and the blue Micro LED chip are all suspended in the transmission channel under the action of the second laser beam.

[0124] S808: The first laser device is turned off, and the red Micro LED chip, the green Micro LED chip, and the blue Micro LED chip fall from the transmission channel to the die bonding area of the circuit board under the action of gravity.

[0125] Referring to Figure 9-8 As shown, after the first laser device 52 is turned off, the red Micro LED chip, the green Micro LED chip, and the blue Micro LED chip suspended in the transmission channel will fall to the die bonding area of the circuit board in the transmission channel under the action of their own gravity, so that the three-color Micro LED chips are simultaneously transferred to the circuit board.

[0126] S809: The transmission channel module and the first laser device are removed, and after the red Micro LED chip, the green Micro LED chip, and the blue Micro LED chip are bonded to the circuit board, the graphene layer is cleaned away with chemical liquid.

[0127] Referring to Figure 9-9As shown, at this time, the red Micro LED chip, the green Micro LED chip and the blue Micro LED chip are dropped onto the die bonding area on the circuit board, the electrodes of the red Micro LED chip, the green Micro LED chip and the blue Micro LED chip are bonded with the die bonding area of the circuit board, the simultaneous bonding of the three-color Micro LED chips is completed, and the graphene layer is cleaned by using a chemical liquid after the bonding.

[0128] In the embodiment, when the third photoelectric reaction sub-layer is arranged on the outer surface of the light-emitting chip electrode, the solder layer arranged on the die bonding area of the circuit board is wrapped on the graphite layer and is bonded with the electrode of the light-emitting chip, and the electrode of the light-emitting chip is conducted with the die bonding area of the circuit board by using the strong conductive property of the graphene.

[0129] By the chip transfer method provided by the application, in the process of transferring the light-emitting chip to the circuit board, the red light Micro LED chip, the blue light Micro LED chip and the green light Micro LED chip can be sequentially separated from the substrate in a preset arrangement mode, and then the Micro LED chips are suspended above the die bonding area on the circuit board under the action of the laser beam, and then the laser beam is turned off, so that the light-emitting chip is dropped onto the circuit board under the action of its own gravity, thereby the red light Micro LED chip, the blue light Micro LED chip and the green light Micro LED chip are simultaneously transferred to the circuit board for simultaneous bonding, the transfer frequency is reduced, the transfer speed is improved, the risk of oxidation of the bonding material caused by multiple bonding is reduced, the transfer efficiency is improved, and the risk of damage of the light-emitting chip in the transfer process is reduced by the suspension transfer.

[0130] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present application.

Claims

1. A die transfer assembly, comprising: It comprises: a substrate; a plurality of light emitting chips to be transferred arranged on the front surface of the substrate; a photoelectric reaction layer formed on the outer surface of each of the light emitting chips, which is used to generate a force to counteract the gravity of the light emitting chip itself when the light emitting chip is transferred from the substrate to a circuit board by photoelectric effect under laser irradiation; the photoelectric reaction layer is a graphene layer; the top surface of the light emitting chip is attached to the front surface of the substrate, the bottom surface of the light emitting chip is opposite to the top surface, and the side surface of the light emitting chip is between the top surface and the bottom surface; the photoelectric reaction layer formed on the outer surface of each of the light emitting chips comprises at least one of the following: a first photoelectric reaction sub-layer arranged on at least two opposite side surfaces of the light emitting chip; a second photoelectric reaction sub-layer arranged on the bottom surface of the light emitting chip; a third photoelectric reaction sub-layer arranged on the outer surface of the electrode when the electrode of the light emitting chip is arranged on the bottom surface.

2. A manufacturing method of the chip transfer assembly according to any one of claims 1, comprising: arranging the plurality of light emitting chips to be transferred on the front surface of the substrate; plating the photoelectric reaction layer on the outer surface of each of the light emitting chips.

3. A chip transfer system characterized by comprising: It comprises: a circuit board, a first laser device and a chip transfer assembly according to any one of claims 1; the circuit board is arranged between the first laser device and the chip transfer assembly, and the light emitting chips to be transferred on the substrate are arranged in alignment with the die bonding areas on the circuit board; a first laser beam generated by the first laser device irradiates the light emitting chips to be transferred on the substrate through the circuit board, and the photoelectric reaction layer on the outer surface of the light emitting chip generates a force to counteract the gravity of the light emitting chip itself by photoelectric effect under the irradiation of the first laser beam, so that the light emitting chip is peeled off from the substrate, and the gravity of the light emitting chip is counteracted by the force to make the light emitting chip float above the die bonding area in alignment with the light emitting chip, and then the light emitting chip falls onto the die bonding area in alignment with the light emitting chip when the force disappears; the photoelectric reaction layer is used to generate a force to counteract the gravity of the light emitting chip itself by photoelectric effect under laser irradiation when the light emitting chip is transferred from the substrate to a circuit board.

4. The chip transfer system of claim 3, wherein It further comprises: a transmission channel module arranged between the substrate and the circuit board, and having a plurality of transmission channels in alignment with each of the die bonding areas on the circuit board and each of the light emitting chips corresponding to the die bonding areas.

5. The chip transfer system according to claim 3 or 4, wherein The chip transfer system further comprises a second laser device, and a second laser beam generated by the second laser device irradiates the light emitting chips to be transferred on the substrate to peel off the light emitting chips from the substrate.

6. A chip transfer method of the chip transfer system according to any one of claims 3 to 5, characterized by, It comprises: peeling off the light emitting chips to be transferred on the substrate from the substrate; The first laser beam generated by the first laser device transmits through the circuit board and irradiates the photoelectric reaction layer on the outer surface of the light emitting chip. The photoelectric reaction layer generates a force to counteract the gravity of the light emitting chip when irradiated by the first laser beam. After the light emitting chip is peeled off from the substrate, its gravity and the force counteract each other, and the light emitting chip is suspended above the corresponding die bonding area. The first laser device is turned off, and the light emitting chip falls onto the corresponding die bonding area under the action of its own gravity.

7. The chip transfer method of the chip transfer system according to claim 6, wherein The method comprises the following steps: The substrate comprises a first substrate, a second substrate, and a third substrate. The light emitting chip comprises a first light emitting chip grown on the first substrate, a second light emitting chip grown on the second substrate, and a third light emitting chip grown on the third substrate. The method of peeling off the light emitting chip to be transferred from the substrate comprises the following steps: The first light emitting chip is peeled off from the first substrate, the second light emitting chip is peeled off from the second substrate, and the third light emitting chip is peeled off from the third substrate. The method of making the light emitting chip fall onto the corresponding die bonding area comprises the following steps: The first laser device is turned off, and the first light emitting chip, the second light emitting chip, and the third light emitting chip fall onto the corresponding die bonding area synchronously, and the first light emitting chip, the second light emitting chip, and the third light emitting chip are bonded to the die bonding area.

8. The chip transfer method of the chip transfer system according to claim 7, wherein When at least one of the first photoelectric reaction sub-layer arranged on at least two opposite sides of the light emitting chip and the second photoelectric reaction sub-layer arranged on the bottom surface of the light emitting chip is arranged, after the first light emitting chip, the second light emitting chip, and the third light emitting chip are bonded to the die bonding area, the method further comprises the following step: removing at least one of the first photoelectric reaction sub-layer and the second photoelectric reaction sub-layer.

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