Display backboard Micro-LED mass transfer device and transfer method

Abstract

The invention discloses a display backboard Micro-LED mass transfer device and a transfer method. The device comprises a die bonding assembly, a flip chip assembly and an external temperature field device. The external temperature field device is used for generating a temperature field, the flip chip mounting head is not limited by the first limiting assembly when the external temperature field device generates the temperature field, and the flip chip mounting head is limited by the first limiting assembly when the temperature field disappears; the second limiting assembly cancels the limiting of the die bonding installation head when the external temperature field device generates the temperature field, and forms the limiting of the die bonding installation head when the temperature field disappears. By arranging the first limiting assembly and the second limiting assembly, an external temperature field does not need to be applied all the time when the transfer device works, after the flip-chip thermostrictive material and the solid crystal thermostrictive material complete longitudinal deformation, the external temperature field device can be closed, and energy can be saved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and specifically to a display backplane Micro-LED mass transfer device and transfer method. Background Technology

[0002] Micro-LED is a display technology that miniaturizes and matrixes LED structures, allowing for individual driving and addressing control of each pixel. Because Micro-LED technology outperforms LCD and OLED technologies in various aspects such as brightness, lifespan, contrast ratio, response time, energy consumption, viewing angle, and resolution, it is considered a next-generation display technology that can surpass OLED and traditional LEDs. However, due to the need for extremely high efficiency, a yield rate of 99.9999%, and transfer accuracy within ±0.5μm during the packaging process, and given that Micro-LED components are generally smaller than 50μm and number in the tens of thousands to millions, a core technical challenge that still needs to be overcome in the industrialization of Micro-LED is the mass transfer technology of Micro-LED components. For modern ultra-precision manufacturing technology, transferring tens of thousands to hundreds of thousands of Micro-LEDs from a wafer to a substrate is already a huge challenge; ensuring processing efficiency, yield, and transfer accuracy is even more difficult.

[0003] Currently, the main methods for mass transfer of Micro-LEDs include electrostatic adsorption, van der Waals force transfer, electromagnetic adsorption, patterned laser ablation, and fluid assembly. The electrostatic adsorption method proposed by LuxVue, the van der Waals force transfer method proposed by X-Celeprint, and the electromagnetic adsorption method proposed by ITRI (Industrial Technology Research Institute) precisely adsorb massive numbers of Micro-LEDs through electrostatic, van der Waals, and electromagnetic forces, respectively, then transfer them to the target substrate and release them precisely. However, these three methods cannot solve the problem of unequal spacing between Micro-LEDs on the wafer and on the substrate. Patterned laser ablation directly removes Micro-LEDs from the wafer using laser, but it requires expensive excimer lasers. Fluid assembly uses a brush to roll on the substrate, placing the Micro-LEDs in a liquid suspension, and using fluid forces to allow the LEDs to fall into corresponding wells on the substrate. However, this method has a certain degree of randomness and cannot guarantee the yield of self-assembly.

[0004] Chinese patent application CN201811203703.9 discloses a mass transfer device and method for Micro-LEDs. This method replaces the rigid structure between the original transfer heads with an elastic, stretchable material and alters the longitudinal deformation of the material using an external physical field, achieving fully controllable mass transfer of electronic components. However, this device requires a continuous external force field during Micro-LED transfer. If the external force field disappears after the elastic, stretchable material completes its longitudinal deformation, it returns to its initial state, causing the spacing between the flip-chip transfer heads and the die-bonding transfer heads to return to their initial positions, thus preventing further Micro-LED transfer. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a mass transfer device and method for Micro-LED display back panel. By setting a limiting component one and a limiting component two, the transfer device does not need to continuously apply an external temperature field during operation. After the flip-chip thermostrictive material and the die-bonded thermostrictive material have completed longitudinal deformation, the external temperature field device can be turned off, which can save energy.

[0006] The technical solution provided by this invention to solve the above problems is as follows: a display backplane Micro-LED mass transfer device, comprising a die-bonding assembly, a flip-chip assembly, and an external temperature field device. The flip-chip assembly is used to pick up Micro-LEDs on the operating table and transfer them to the die-bonding assembly. The die-bonding assembly is used to transfer the Micro-LEDs to the mounting positions. The die-bonding assembly includes a plurality of die-bonding heads, and the flip-chip assembly includes a plurality of flip-chip mounting heads. The external temperature field device is used to generate a temperature field to change the spacing between two adjacent die-bonding heads of the die-bonding assembly and the spacing between two adjacent flip-chip mounting heads of the flip-chip assembly to adapt to different target substrates.

[0007] It also includes a limiting component one and a limiting component two. The limiting component one is installed on the flip-chip assembly, and the limiting component two is installed on the die-bonding assembly. The limiting component one cancels the limiting of the flip-chip mounting head when the external temperature field device generates a temperature field and forms the limiting of the flip-chip mounting head when the temperature field disappears. The limiting component two cancels the limiting of the die-bonding head when the external temperature field device generates a temperature field and forms the limiting of the die-bonding head when the temperature field disappears.

[0008] Preferably, the flip-chip assembly further includes a flip-chip rotary motor, a flip-chip frame, a flip-chip thermostrictive material, several connecting rods, and several flip-chip bonding arms. The flip-chip rotary motor is connected to the flip-chip frame to rotate the flip-chip frame. The flip-chip bonding arms are mounted on the flip-chip frame, and the flip-chip mounting heads are movably mounted on the flip-chip bonding arms. A flip-chip transfer head is mounted at the bottom of the flip-chip mounting head. The connecting rods are used to connect the flip-chip mounting heads on two adjacent flip-chip bonding arms, and the connecting rods are perpendicular to the flip-chip bonding arms. A flip-chip thermostrictive material is disposed between two adjacent flip-chip mounting heads on one or two flip-chip bonding arms. The external temperature field device generates a temperature field that causes the flip-chip thermostrictive material to deform.

[0009] Preferably, the flip-chip assembly further includes flip-chip springs, which are installed at both ends of the flip-chip welding arm. The flip-chip springs have a flip-chip preload force, which is greater than the elastic force of the flip-chip thermostrictive material without a temperature field, but less than the elastic force of the flip-chip thermostrictive material with a temperature field.

[0010] Preferably, the limiting component one includes a mounting base one, a guide rod one, a return spring one, a movable head one, a limiting ring one, and a friction block one. The flip-chip mounting head is provided with a mating hole one that mates with the flip-chip bonding arm. The die-bonding mounting head is also provided with a receiving cavity one for mounting the limiting component one. The mounting base one is disposed in the receiving cavity one. One end of the guide rod one is connected to the mounting base one, and the other end is movably connected to the movable head one. The limiting ring one is mounted on the outer circumferential surface of the movable head one. The receiving cavity one communicates with the mating hole one through the movable hole one. The return spring one is sleeved on the guide rod one. The movable head one is sleeved with a telescopic ring one made of flip-chip thermostrictive material. One end of the telescopic ring one abuts against the limiting ring one, and the other end abuts against the cavity wall of the receiving cavity one. One end of the movable head one extends into the mating hole one. The friction block one is mounted on the end of the movable head located in the mating hole one.

[0011] Preferably, the limiting component one further includes an electromagnet one and a magnetic block one. The electromagnet one is installed on the end face of the limiting ring one away from the telescopic ring one, and the magnetic block one is installed on the cavity wall of the receiving cavity one. When the electromagnet one is energized, it attracts the magnetic block one, causing the movable head one to move in the direction of compression of the return spring one.

[0012] Preferably, the die bonding assembly further includes a die bonding frame, a die bonding thermostrictive material, several connecting rods, and several die bonding arms. The die bonding arms are mounted on the die bonding frame, and the die bonding head is movably mounted on the die bonding arm. A die bonding transfer head is mounted at the bottom of the die bonding head. The connecting rods are used to connect the die bonding heads on two adjacent die bonding arms, and the connecting rods are perpendicular to the die bonding arms. A die bonding thermostrictive material is disposed between two adjacent die bonding heads on one or two die bonding arms, and the external temperature field device causes the die bonding thermostrictive material to deform after generating a temperature field.

[0013] Preferably, the die bonding assembly further includes die bonding springs, which are installed at both ends of the die bonding arm. The die bonding springs have a die bonding preload force, which is greater than the elastic force of the die bonding thermostrictive material without a temperature field, but less than the elastic force of the die bonding thermostrictive material with a temperature field.

[0014] Preferably, the limiting component two includes a mounting base two, a guide rod two, a reset spring two, a movable head two, a limiting ring two, and a friction block two. The die-bonding mounting head is provided with a mating hole two that mates with the die-bonding arm. The die-bonding mounting head is also provided with a receiving cavity two for mounting the limiting component two. The mounting base two is disposed in the receiving cavity two. One end of the guide rod two is connected to the mounting base two, and the other end is movably connected to the movable head two. The limiting ring two is installed on the outer circumferential surface of the movable head two. The receiving cavity two communicates with the mating hole two through the movable hole two. The reset spring two is sleeved on the guide rod two. The movable head two is sleeved with a telescopic ring two made of die-bonding thermostrictive material. One end of the telescopic ring two abuts against the limiting ring two, and the other end abuts against the cavity wall of the receiving cavity two. One end of the movable head two extends into the mating hole two. The friction block two is installed at the end of the movable head located in the mating hole two.

[0015] Preferably, the limiting component two further includes an electromagnet two and a magnetic block two. The electromagnet two is installed on the end face of the limiting ring two away from the telescopic ring two, and the magnetic block two is installed on the cavity wall of the receiving cavity two. When the electromagnet two is energized, it attracts the magnetic block two, causing the movable head two to move in the direction of compression of the reset spring two.

[0016] The present invention also discloses a transfer method using a Micro-LED mass transfer device for a display backplane as described in any one of the above claims, the method comprising the following steps:

[0017] S1. Before the transfer, first energize electromagnet one and electromagnet two. Electromagnet one is attracted to magnetic block one, friction block one is disengaged from flip-chip bonding arm, electromagnet two is attracted to magnetic block two, friction block two is disengaged from die bonding arm, flip-chip mounting head is in the initial position under the action of flip-chip spring, die bonding head is in the initial position under the action of die bonding spring, and then control electromagnet one and electromagnet two to be de-energized; through the operating table, keep the flip-chip transfer head at a certain distance from the Micro-LED to be transferred. The Micro-LED to be transferred is arranged on the substrate. Start the external temperature field device to apply a temperature field to the flip-chip thermostrictive material and the expansion ring one. The flip-chip thermostrictive material deforms and drives the flip-chip transfer head to accurately align with the substrate Micro-LED. Then turn off the external temperature field device. Then, when a positive voltage is applied to the flip-chip transfer head, grab the Micro-LED.

[0018] S2. The flip-chip rotary motor flips the flip-chip transfer head, while the die-bonding transfer head approaches the flip-chip transfer head and clamps the Micro-LED with the flip-chip transfer head. A positive voltage is applied to the die-bonding transfer head to grip the Micro-LED, and a negative voltage is applied to the flip-chip transfer head to release the Micro-LED.

[0019] S3. Measure the distance between two adjacent die-bonding heads. When the distance between two adjacent die-bonding heads is less than the target substrate Micro-LED spacing, calculate the required external temperature field value to be applied to the die-bonding thermo-expanding material based on the required Micro-LED spacing. Control the external temperature field device to apply a temperature field to the die-bonding thermo-expanding material and the second expansion ring to change the longitudinal deformation of the die-bonding thermo-expanding material. When the distance between two adjacent die-bonding heads is greater than the target substrate Micro-LED spacing, control the second electromagnet to be energized, so that the second electromagnet is attracted to the second magnetic block, the second friction block is disengaged from the die-bonding arm, and the fixed mounting head returns to the initial position under the action of the die-bonding spring. Calculate the required external temperature field value to be applied to the die-bonding thermo-expanding material based on the required Micro-LED spacing. Then control the external temperature field device to apply a temperature field to the die-bonding thermo-expanding material and the second expansion ring to change the longitudinal deformation of the die-bonding thermo-expanding material. After the die-bonding thermo-expanding material has deformed, turn off the external temperature field device.

[0020] S4. The Micro-LED picked up by the die-bonding transfer head is positioned at the target location, and the Micro-LED is placed after the die-bonding transfer head moves down to the target substrate and a negative voltage is applied.

[0021] S5. Repeat steps S1-S4 to achieve mass transfer of Micro-LEDs.

[0022] Compared with the prior art, the advantages of the present invention are: by setting limiting component one and limiting component two, the present invention does not require the external temperature field to be applied continuously during the operation of the transfer device. After the flip-chip thermostrictive material and the solid-chip thermostrictive material have completed longitudinal deformation, the external temperature field device can be turned off, which can save energy. Attached Figure Description

[0023] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0024] Figure 1 This is a schematic diagram of the flip-chip assembly of the present invention;

[0025] Figure 2 This is a schematic diagram of the die-bonding assembly of the present invention;

[0026] Figure 3 This is a cross-sectional schematic diagram of the flip-chip module of the present invention adsorbing Micro-LEDs;

[0027] Figure 4 This is a cross-sectional schematic diagram of the flipping of the flip-chip transfer head and the docking and exchange of the die-bonding transfer head according to the present invention;

[0028] Figure 5 This is a cross-sectional view of the flip-chip mounting head and limiting component of the present invention;

[0029] Figure 6 yes Figure 5 Enlarged view of point A in the middle;

[0030] Figure 7 This is a cross-sectional view of the die bonding head and limiting component 2 of the present invention.

[0031] Figure reference numerals: 1. Flip Chip holder, 2. Flip Chip bonding arm, 3. Flip Chip thermostrictive material, 4. Flip Chip spring, 5. Flip Chip mounting head, 6. Die bond holder, 7. Die bond bonding arm, 8. Die bond thermostrictive material, 9. Die bond mounting head, 10. Die bond spring, 11. Flip Chip transfer head, 12. Micro-LED, 13. Die bond transfer head, 14. Mating hole one, 15. Receiving cavity one, 16. Mounting base one, 17. Return spring one, 18. Magnetic block one, 19. Electromagnet one, 20. 21. Limiting ring 1, 22. Telescopic ring 1, 23. Guide rod 1, 24. Movable head 1, 25. Friction block 1, 26. Receiving hole, 27. Movable hole 1, 28. Receiving cavity 2, 29. Mating hole 2, 30. Limiting ring 2, 31. Electromagnet 2, 32. Magnetic block 2, 33. Return spring 2, 34. Mounting base 2, 35. Guide rod 2, 36. Telescopic ring 2, 37. Movable head 2, 38. Friction block 2, 39. Flip crystal rotary motor, 40. Connecting rod 1, 41. Connecting rod 2. Detailed Implementation

[0032] The following will describe in detail the implementation of the present invention with reference to the accompanying drawings and embodiments, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0033] In the description of this invention, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature, and in the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0037] It should also be understood that the terminology used in this specification of embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. As used in this specification of embodiments of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] Example 1

[0039] A mass transfer device for Micro-LEDs on a display backplane includes a die-bonding assembly, a flip-chip assembly, and an external temperature field device. The flip-chip assembly picks up Micro-LEDs from the worktable and transfers them to the die-bonding assembly. The die-bonding assembly transfers the Micro-LEDs to mounting positions. The die-bonding assembly includes a plurality of die-bonding heads 9, and the flip-chip assembly includes a plurality of flip-chip mounting heads 5. The external temperature field device generates a temperature field to change the spacing between adjacent die-bonding heads 9 of the die-bonding assembly and the spacing between adjacent flip-chip mounting heads 5 of the flip-chip assembly to adapt to different target substrates.

[0040] It also includes a limiting component one and a limiting component two. The limiting component one is installed on the flip-chip assembly, and the limiting component two is installed on the die-bonding assembly. The limiting component one cancels the limiting of the flip-chip mounting head 5 when the external temperature field device generates a temperature field, and forms the limiting of the flip-chip mounting head 5 when the temperature field disappears. The limiting component two cancels the limiting of the die-bonding head 9 when the external temperature field device generates a temperature field, and forms the limiting of the die-bonding head 9 when the temperature field disappears.

[0041] In the above scheme, by setting limit component one and limit component two, the transfer device does not need to continuously apply an external temperature field during operation. After the flip-chip thermostrictive material and the solid-state thermostrictive material have completed longitudinal deformation, the external temperature field device can be turned off, which can save energy. Furthermore, the flip-chip thermostrictive material and the solid-state thermostrictive material do not need to be in a deformed state all the time, which can improve their service life.

[0042] It should be noted that during actual operation, the external temperature field device may malfunction and require restarting or repair. If the external temperature field device fails to operate properly after the flip-chip transfer head or die-bonding transfer head picks up the Micro-LED, the flip-chip thermostrictive material or die-bonding thermostrictive material will return to its original state after losing the effect of the temperature field. This will cause a change in the spacing between two adjacent flip-chip mounting heads or two adjacent die-bonding heads, making it impossible for the Micro-LED transfer to proceed normally. This solution, by setting limit component one and limit component two, can limit the flip-chip mounting head and die-bonding head when the external temperature field device fails, preventing changes in the spacing between two adjacent flip-chip mounting heads or two adjacent die-bonding heads, thus ensuring the smooth progress of the transfer operation.

[0043] Specifically, such as Figure 1 , Figure 3 and Figure 4As shown, the flip-chip assembly also includes a flip-chip rotary motor 38, a flip-chip frame 1, a flip-chip thermostrictive material 3, several connecting rods 39, and several flip-chip bonding arms 2. The flip-chip rotary motor 38 is connected to the flip-chip frame 1 to rotate the flip-chip frame 1. The flip-chip bonding arms 2 are mounted on the flip-chip frame 1. The flip-chip mounting head 5 is movably mounted on the flip-chip bonding arm 2. A flip-chip transfer head 11 is mounted at the bottom of the flip-chip mounting head 5. The connecting rods 39 are used to connect the flip-chip mounting heads 5 on two adjacent flip-chip bonding arms 2. The connecting rods 39 and... The flip-chip bonding arms 2 are perpendicular to each other; a flip-chip thermostrictive material 3 is provided between two adjacent flip-chip mounting heads 5 on one or two flip-chip bonding arms 2, and the external temperature field device generates a temperature field to cause the flip-chip thermostrictive material 3 to deform; furthermore, the flip-chip assembly also includes a flip-chip spring 4, which is installed at both ends of the flip-chip bonding arm 2. The flip-chip spring 4 has a flip-chip preload force, which is greater than the elastic force of the flip-chip thermostrictive material 3 when no temperature field is applied, and less than the elastic force of the flip-chip thermostrictive material 3 when a temperature field is applied.

[0044] In the above scheme, a connecting rod is used to connect the flip-chip mounting heads on two adjacent flip-chip bonding arms 2, i.e. Figure 1 As shown, two adjacent flip-chip mounting heads on the same longitudinal straight line are connected by a connecting rod. Then, a flip-chip thermostrictive material is placed between two adjacent flip-chip mounting heads 5 on one or two flip-chip welding arms 2. Through the connecting action of the connecting rod, it is possible to install the flip-chip thermostrictive material on only one or two flip-chip welding arms. When the flip-chip thermostrictive material deforms, it can drive the spacing between two adjacent flip-chip mounting heads on multiple flip-chip welding arms 2 to change. Therefore, it is not necessary to install the flip-chip thermostrictive material on every flip-chip welding arm, thus saving material. Furthermore, as those skilled in the art know, due to processing limitations, the thickness and length of the flip-chip thermostrictive material installed on the flip-chip welding arms cannot be made completely consistent. Therefore, the more flip-chip thermostrictive material used, the more instances of inconsistent lengths after deformation occur. In this solution, installing the flip-chip thermostrictive material on only one or two flip-chip welding arms can reduce the occurrence of this situation.

[0045] In this embodiment, as Figure 5 and Figure 6As shown, the limiting component includes a mounting base 16, a guide rod 22, a return spring 17, a movable head 23, a limiting ring 20, and a friction block 24. The flip-chip mounting head 5 has a mating hole 14 that mates with the flip-chip bonding arm 2. The die-bonding mounting head 9 also has a receiving cavity 15 for mounting the limiting component. The mounting base 16 is disposed within the receiving cavity 15. One end of the guide rod 22 is connected to the mounting base 16, and the other end is movably connected to the movable head 23. The limiting ring 20 is mounted on the outer circumferential surface of the movable head 23. The receiving cavity 15 communicates with the mating hole 14 through a movable hole 26. The return spring 17 is sleeved on the guide rod 22. A telescopic ring 21 made of flip-chip thermostrictive material 3 is fitted on the moving head 23. One end of the telescopic ring 21 abuts against the limiting ring 20, and the other end abuts against the cavity wall of the receiving cavity 15. One end of the moving head 23 extends into the mating hole 14. The friction block 24 is installed on the end of the moving head located in the mating hole 14. Furthermore, the limiting component also includes an electromagnet 19 and a magnetic block 18. The electromagnet 19 is installed on the end face of the limiting ring 20 away from the telescopic ring 21, and the magnetic block 18 is installed on the cavity wall of the receiving cavity 15. When the electromagnet 19 is energized, it attracts the magnetic block 18, causing the moving head 23 to move in the direction of compression of the return spring 17.

[0046] It should be noted that in the above scheme, when the external temperature field device applies a temperature field, the telescopic ring made of the flip-chip thermostrictive material 3 will also undergo longitudinal deformation, and its axial length will increase. During the process of the telescopic ring increasing its axial length, it pushes the movable head to move in the direction of compression of the return spring, so that the friction block 1 disengages from the flip-chip welding arm, and the limiting component 1 cancels the limiting of the flip-chip mounting head, so that the flip-chip mounting head can move normally on the flip-chip welding arm; when the temperature field applied by the external temperature field device disappears, the movable head moves to the right under the action of the return spring, the friction block 1 comes into close contact with the flip-chip welding arm, and the limiting component 1 forms a limiting of the flip-chip mounting head; when it is necessary to reset the position of the flip-chip mounting head, it is only necessary to energize the electromagnet 1 and keep the external temperature field device closed, and the flip-chip mounting head returns to the initial position under the action of the flip-chip spring. The above solution utilizes the temperature field applied by the external temperature field device during the Micro-LED transfer process to cause the expansion ring made of flip-chip thermostrictive material to deform, thereby releasing the restriction on the flip-chip mounting head and making full use of the external temperature field; and it achieves the simultaneous change of the spacing of the flip-chip mounting head and the release of the restriction on the flip-chip mounting head without producing errors.

[0047] Among them, such as Figure 2 and Figure 4As shown, the die bonding assembly further includes a die bonding frame 6, a die bonding thermostrictive material 8, several connecting rods 40, and several die bonding arms 7. The die bonding arms 7 are mounted on the die bonding frame 6, and the die bonding head 9 is movably mounted on the die bonding arm 7. A die bonding transfer head 13 is mounted at the bottom of the die bonding head 9. The connecting rods 40 are used to connect the die bonding heads 9 on two adjacent die bonding arms 7, and the connecting rods 40 are perpendicular to the die bonding arms 7. One or two die bonding arms... A die-bonding thermostrictive material 8 is disposed between two adjacent die-bonding mounting heads 9 on arm 7. After the external temperature field device generates a temperature field, the die-bonding thermostrictive material 8 deforms. Furthermore, the die-bonding assembly also includes a die-bonding spring 10, which is installed at both ends of the die-bonding arm 7. The die-bonding spring 10 has a die-bonding preload force, which is greater than the elastic force of the die-bonding thermostrictive material 8 when no temperature field is applied, but less than the elastic force of the die-bonding thermostrictive material 8 when a temperature field is applied.

[0048] In the above scheme, the die bonding heads on two adjacent die bonding arms 2 are connected by a connecting rod 2, as shown in the figure. Figure 1 As shown, two adjacent die-bonding heads on the same longitudinal straight line are connected by a connecting rod 2. Then, die-bonding thermostrictive material is placed between two adjacent die-bonding heads 5 on one or two die-bonding arms 2. Through the connecting action of the connecting rod 2, it is possible to install die-bonding thermostrictive material on only one or two die-bonding arms. When the die-bonding thermostrictive material deforms, it can drive the spacing between two adjacent die-bonding heads on multiple die-bonding arms 2 to change. Therefore, it is not necessary to install die-bonding thermostrictive material on every die-bonding arm, thus saving material. Furthermore, as those skilled in the art know, due to processing limitations, the thickness and length of the die-bonding thermostrictive material installed on the die-bonding arms cannot be made completely consistent. Therefore, the more die-bonding thermostrictive material used, the more instances of inconsistent lengths after deformation occur. In this solution, installing die-bonding thermostrictive material on only one or two die-bonding arms can reduce the occurrence of this situation.

[0049] Among them, such as Figure 7As shown, the second limiting component includes a second mounting base 33, a second guide rod 34, a second return spring 32, a second movable head 36, a second limiting ring 29, and a second friction block 37. The die bonding mounting head 9 is provided with a second mating hole 28 that mates with the die bonding arm 7. The die bonding mounting head 9 is also provided with a second receiving cavity 27 for mounting the second limiting component. The second mounting base 33 is disposed within the second receiving cavity 27. One end of the second guide rod 34 is connected to the second mounting base 33, and the other end is movably connected to the second movable head 36. The second limiting ring 29 is mounted on the outer circumferential surface of the second movable head 36. The second receiving cavity 27 communicates with the second mating hole 28 through the second movable hole. The second return spring 32 is sleeved on the second guide rod 34. The movable head 36 is fitted with a telescopic ring 35 made of a solid-state thermostrictive material 8. One end of the telescopic ring 35 abuts against the limiting ring 29, and the other end abuts against the cavity wall of the receiving cavity 27. One end of the movable head 36 extends into the mating hole 28. The friction block 37 is installed at the end of the movable head located in the mating hole 28. Furthermore, the limiting component 2 also includes an electromagnet 30 and a magnetic block 31. The electromagnet 30 is installed on the end face of the limiting ring 29 away from the telescopic ring 35. The magnetic block 31 is installed on the cavity wall of the receiving cavity 27. When the electromagnet 30 is energized, it attracts the magnetic block 31, causing the movable head 36 to move in the direction of compression of the return spring 32.

[0050] It should be noted that the working principle of the second limiting component is the same as that of the first limiting component, so it will not be described in detail here.

[0051] It should be noted that in this invention, the flip-chip thermostrictive material and the flip-chip mounting head, as well as the die-bonding thermostrictive material and the die-bonding mounting head, are in contact connection, meaning they are not fixed together. When the applied temperature field disappears, the flip-chip thermostrictive material and the die-bonding thermostrictive material return to their initial state and detach from the flip-chip mounting head and the die-bonding mounting head.

[0052] Specifically, both flip-chip thermostrictive materials and solid-chip thermostrictive materials are titanium alloy shape memory materials.

[0053] It should be noted that since Micro-LEDs are generated on wafers, and the blue film is applied to the wafer surface to hold the Micro-LEDs together (at this point, the Micro-LEDs have already been flipped over, and the pins have also been flipped), they need to be flipped over by a flip chip machine. This means that the flip chip frame and the die bond frame are needed to flip the Micro-LEDs again. Therefore, this invention uses both the flip chip frame and the die bond frame together to achieve the mass transfer of Micro-LEDs.

[0054] Both the flip-chip transfer head and the die-bonding transfer head have a bipolar structure. When a positive voltage is applied, they grip the Micro-LED, and when a negative voltage is applied, they release the Micro-LED. This method of gripping and releasing the Micro-LED by applying positive and negative voltages not only prevents damage to the Micro-LED during the transfer process but also simplifies the equipment structure and ensures reliable gripping and releasing actions.

[0055] Example 2

[0056] This embodiment discloses a transfer method using a Micro-LED mass transfer device for display backplanes as described in Embodiment 1. The method includes the following steps:

[0057] S1. Before the transfer, first energize electromagnet 19 and electromagnet 20. Electromagnet 19 is attracted to magnetic block 18, friction block 24 is disengaged from flip-chip bonding arm 2, electromagnet 20 is attracted to magnetic block 21, friction block 27 is disengaged from die bonding arm 7, flip-chip mounting head 5 is in the initial position under the action of flip-chip spring 4, and die bonding head 9 is in the initial position under the action of die bonding spring 10. Then, control electromagnet 19 and electromagnet 20 to be de-energized. Through the operating table, keep the flip-chip transfer head 11 at a certain distance from the Micro-LED to be transferred. The Micro-LED to be transferred is arranged on the substrate. Start the external temperature field device to apply a temperature field to the flip-chip thermostrictive material 3 and the expansion ring 21. The flip-chip thermostrictive material 3 deforms and drives the flip-chip transfer head 11 to accurately align with the substrate Micro-LED. Then, turn off the external temperature field device. Then, when a positive voltage is applied to the flip-chip transfer head 11, grab the Micro-LED.

[0058] S2. The flip-chip rotary motor 38 flips the flip-chip transfer head 11, while the die-bonding transfer head 13 approaches the flip-chip transfer head 11 and clamps the Micro-LED with the flip-chip transfer head 11. A positive voltage is applied to the die-bonding transfer head 13 to grip the Micro-LED, and a negative voltage is applied to the flip-chip transfer head 11 to release the Micro-LED.

[0059] S3. Measure the distance between two adjacent die-bonding heads 9. When the distance between two adjacent die-bonding heads 9 is less than the target substrate Micro-LED spacing, calculate the required external temperature field value to be applied to the die-bonding thermostrictive material 8 based on the required Micro-LED spacing, and control the external temperature field device to apply a temperature field to the die-bonding thermostrictive material 8 and the expansion ring 35 to change the longitudinal deformation of the die-bonding thermostrictive material 8. When the distance between two adjacent die-bonding heads 9 is greater than the target substrate Micro-LED spacing, control the electromagnetic... When the second electromagnet 30 is energized, it attracts the second electromagnet 30 and the second magnetic block 31, and the second friction block 37 disengages from the die bonding arm 7. The fixed mounting head 9 returns to its initial position under the action of the die bonding spring 10. According to the required spacing of the Micro-LEDs, the required external temperature field value to be applied to the die bonding thermostrictive material 8 is calculated. Then, the external temperature field device is controlled to apply a temperature field to the die bonding thermostrictive material 8 and the second expansion ring 35 to change the longitudinal deformation of the die bonding thermostrictive material 8. After the die bonding thermostrictive material 8 has deformed, the external temperature field device is turned off.

[0060] S4. The Micro-LED picked up by the die-bonding transfer head 13 is positioned at the target location. After the die-bonding transfer head 13 moves down to the target substrate, a negative voltage is applied to place the Micro-LED.

[0061] S5. Repeat steps S1-S4 to achieve mass transfer of Micro-LEDs.

[0062] The above description only illustrates the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All modifications made within the scope of the independent claims of this invention are also within the scope of protection of this invention.

Claims

1. A display backplane Micro-LED mass transfer device, comprising a die-bonding assembly, a flip-chip assembly, and an external temperature field device, wherein the flip-chip assembly is used to pick up Micro-LEDs (12) on the operating table and transfer them to the die-bonding assembly, and the die-bonding assembly is used to transfer the Micro-LEDs (12) to the mounting positions; the die-bonding assembly includes a plurality of die-bonding heads (9), the flip-chip assembly includes a plurality of flip-chip mounting heads (5), and the external temperature field device is used to generate a temperature field to change the spacing between two adjacent die-bonding heads (9) of the die-bonding assembly and the spacing between two adjacent flip-chip mounting heads (5) of the flip-chip assembly to adapt to different target substrates, characterized in that: It also includes a limiting component one and a limiting component two. The limiting component one is installed on the flip-chip assembly, and the limiting component two is installed on the die-bonding assembly. The limiting component one cancels the limiting of the flip-chip mounting head (5) when the external temperature field device generates a temperature field and forms the limiting of the flip-chip mounting head (5) when the temperature field disappears. The limiting component two cancels the limiting of the die-bonding head (9) when the external temperature field device generates a temperature field and forms the limiting of the die-bonding head (9) when the temperature field disappears.

2. The display backplane Micro-LED mass transfer device according to claim 1, characterized in that: The flip-chip assembly also includes a flip-chip rotary motor (38), a flip-chip frame (1), a flip-chip thermostrictive material (3), several connecting rods (39) and several flip-chip bonding arms (2). The flip-chip rotary motor (38) is connected to the flip-chip frame (1) to rotate the flip-chip frame (1). The flip-chip bonding arms (2) are mounted on the flip-chip frame (1). The flip-chip mounting head (5) is movably mounted on the flip-chip bonding arm (2). A flip-chip transfer head (11) is mounted at the bottom of the flip-chip mounting head (5). The connecting rods (39) are used to connect the flip-chip mounting heads (5) on two adjacent flip-chip bonding arms (2). The connecting rods (39) are perpendicular to the flip-chip bonding arms (2). A flip-chip thermostrictive material (3) is provided between two adjacent flip-chip mounting heads (5) on one or two flip-chip bonding arms (2). The external temperature field device generates a temperature field to deform the flip-chip thermostrictive material (3).

3. The display backplate Micro-LED mass transfer device according to claim 2, characterized in that: The flip-chip assembly also includes a flip-chip spring (4), which is installed at both ends of the flip-chip welding arm (2). The flip-chip spring (4) has a flip-chip preload force, which is greater than the elastic force of the flip-chip thermostrictive material (3) when no temperature field is applied, and less than the elastic force of the flip-chip thermostrictive material (3) when a temperature field is applied.

4. The display backplate Micro-LED mass transfer device according to claim 2, characterized in that: The limiting component includes a mounting base (16), a guide rod (22), a reset spring (17), a movable head (23), a limiting ring (20), and a friction block (24). The flip-chip mounting head (5) is provided with a mating hole (14) that mates with the flip-chip bonding arm (2). The die-bonding mounting head (9) is also provided with a receiving cavity (15) for mounting the limiting component. The mounting base (16) is disposed in the receiving cavity (15). One end of the guide rod (22) is connected to the mounting base (16), and the other end is movably connected to the movable head (23). The limiting ring (20) is mounted on... On the outer circumferential surface of the movable head (23), the receiving cavity (15) is connected to the mating hole (14) through the movable hole (26). The reset spring (17) is sleeved on the guide rod (22). The movable head (23) is sleeved with a telescopic ring (21) made of flip-chip thermostrictive material (3). One end of the telescopic ring (21) abuts against the limiting ring (20), and the other end abuts against the cavity wall of the receiving cavity (15). One end of the movable head (23) extends into the mating hole (14). The friction block (24) is installed at the end of the movable head located in the mating hole (14).

5. The display backplate Micro-LED mass transfer device according to claim 4, characterized in that: The limiting component also includes an electromagnet (19) and a magnetic block (18). The electromagnet (19) is installed on the end face of the limiting ring (20) away from the telescopic ring (21). The magnetic block (18) is installed on the cavity wall of the receiving cavity (15). When the electromagnet (19) is energized, it attracts the magnetic block (18) to move the movable head (23) in the direction of compression of the return spring (17).

6. The display backplane Micro-LED mass transfer device according to claim 1, characterized in that: The die bonding assembly further includes a die bonding frame (6), a die bonding thermostrictive material (8), several connecting rods (40), and several die bonding arms (7). The die bonding arms (7) are mounted on the die bonding frame (6), and the die bonding head (9) is movably mounted on the die bonding arm (7). A die bonding transfer head (13) is mounted at the bottom of the die bonding head (9). The connecting rods (40) are used to connect the die bonding heads (9) on two adjacent die bonding arms (7). The connecting rods (40) are perpendicular to the die bonding arms (7). A die bonding thermostrictive material (8) is provided between two adjacent die bonding heads (9) on one or two die bonding arms (7). The external temperature field device generates a temperature field, causing the die bonding thermostrictive material (8) to deform.

7. A display backplate Micro-LED mass transfer device according to claim 6, characterized in that: The die bonding assembly also includes a die bonding spring (10), which is installed at both ends of the die bonding arm (7). The die bonding spring (10) has a die bonding preload force, which is greater than the elastic force of the die bonding thermostrictive material (8) when no temperature field is applied, and less than the elastic force of the die bonding thermostrictive material (8) when a temperature field is applied.

8. A display backplate Micro-LED mass transfer device according to claim 6, characterized in that: The second limiting component includes a second mounting base (33), a second guide rod (34), a second reset spring (32), a second movable head (36), a second limiting ring (29), and a second friction block (37). The die bonding head (9) is provided with a second mating hole (28) that mates with the die bonding arm (7). The die bonding head (9) is also provided with a second receiving cavity (27) for mounting the second limiting component. The second mounting base (33) is disposed in the second receiving cavity (27). One end of the second guide rod (34) is connected to the second mounting base (33), and the other end is movably connected to the second movable head (36). The second limiting ring (29) is... The second movable head (36) is installed on the outer circumferential surface of the second movable head (36). The second receiving cavity (27) is connected to the second mating hole (28) through the second movable hole. The second reset spring (32) is sleeved on the second guide rod (34). The second movable head (36) is sleeved with a telescopic ring (35) made of solid-state thermostrictive material (8). One end of the telescopic ring (35) abuts against the second limiting ring (29), and the other end abuts against the cavity wall of the second receiving cavity (27). One end of the second movable head (36) extends into the second mating hole (28). The second friction block (37) is installed at the end of the movable head located in the second mating hole (28).

9. A display backplate Micro-LED mass transfer device according to claim 8, characterized in that: The second limiting component also includes an electromagnet (30) and a magnetic block (31). The electromagnet (30) is installed on the end face of the limiting ring (29) away from the telescopic ring (35). The magnetic block (31) is installed on the cavity wall of the receiving cavity (27). When the electromagnet (30) is energized, it attracts the magnetic block (31) to move the movable head (36) in the direction of compression of the reset spring (32).

10. A transfer method using a Micro-LED mass transfer device for a display backplane as described in any one of claims 1-9, characterized in that: The method includes the following steps: S1. Before the transfer, first energize electromagnet one (19) and electromagnet two (30). Electromagnet one (19) is attracted to magnetic block one (18), friction block one (24) is disengaged from flip-chip bonding arm (2), electromagnet two (30) is attracted to magnetic block two (31), friction block two (37) is disengaged from die bonding arm (7), flip-chip mounting head (5) is in the initial position under the action of flip-chip spring (4), die bonding head (9) is in the initial position under the action of die bonding spring (10), and then control electromagnet one (19) and electromagnet two (30) to be energized. 30) Power off; keep the flip-chip transfer head (11) at a certain distance from the Micro-LED to be transferred through the operating table. The Micro-LED to be transferred is arranged on the substrate. Start the external temperature field device to apply a temperature field to the flip-chip thermostrictive material (3) and the expansion ring (21). The flip-chip thermostrictive material (3) deforms and drives the flip-chip transfer head (11) to accurately align with the substrate Micro-LED. Then turn off the external temperature field device. Then grab the Micro-LED when a positive voltage is applied to the flip-chip transfer head (11). S2. The flip-chip rotary motor (38) flips the flip-chip transfer head (11), while the die-bonding transfer head (13) approaches the flip-chip transfer head (11) and clamps the Micro-LED with the flip-chip transfer head (11). A positive voltage is applied to the die-bonding transfer head (13) to grip the Micro-LED, and a negative voltage is applied to the flip-chip transfer head (11) to release the Micro-LED. S3. Measure the distance between two adjacent die-bonding heads (9). When the distance between two adjacent die-bonding heads (9) is less than the target substrate Micro-LED spacing, calculate the required external temperature field value to be applied to the die-bonding thermostrictive material (8) based on the required Micro-LED spacing, and control the external temperature field device to apply a temperature field to the die-bonding thermostrictive material (8) and the expansion ring II (35) to change the longitudinal deformation of the die-bonding thermostrictive material (8). When the distance between two adjacent die-bonding heads (9) is greater than the target substrate Micro-LED spacing, control the electromagnet II (30) to apply a temperature field to the die-bonding thermostrictive material (8) and the expansion ring II (35) to change the longitudinal deformation of the die-bonding thermostrictive material (8). When the power is turned on, the electromagnet (30) and the magnetic block (31) are attracted together, the friction block (37) is disengaged from the die bonding arm (7), and the fixed mounting head (9) returns to the initial position under the action of the die bonding spring (10). According to the required spacing of Micro-LEDs, the required external temperature field value to be applied to the die bonding thermo-expanding material (8) is calculated. Then, the external temperature field device is controlled to apply a temperature field to the die bonding thermo-expanding material (8) and the expansion ring (35) to change the longitudinal deformation of the die bonding thermo-expanding material (8). After the die bonding thermo-expanding material (8) has deformed, the external temperature field device is turned off. S4. The Micro-LED grasped by the die-bonding transfer head (13) is positioned at the target position, and the Micro-LED is placed when the die-bonding transfer head (13) is moved down to the target substrate and a negative voltage is applied. S5. Repeat steps S1-S4 to achieve mass transfer of Micro-LEDs.

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