A multi-needle mechanical crystal stabbing type Mini-LED mass transfer system and method of use

Abstract

The present invention discloses a multi-needle mechanical crystal piercing type Mini-LED mass transfer system and a usage method. The system includes a substrate assembly line, a planar motion platform, and a multi-needle crystal piercing device. The multi-needle crystal piercing device includes a crystal piercing head assembly and a three-axis motion gantry. The crystal piercing head assembly includes a bottom plate and a plurality of sub-crystal piercing heads. The bottom plate is provided with a needle outlet hole, and the plurality of sub-crystal piercing heads are circumferentially distributed around the outer periphery of the needle outlet hole. The sub-crystal piercing head includes a housing, a motor, and a tungsten needle clamping. The housing is provided with a guide rail, and the tungsten needle clamping is slidably arranged on the housing along the guide rail. The movement of the tungsten needle clamping causes the tungsten needle to switch between a first position state and a second position state. In addition, this solution also proposes a usage method of using the above system. The multi-needle mechanical crystal piercing type Mini-LED mass transfer system and method proposed by the present invention solve the problems of low current transfer efficiency, the needle density being restricted by the thickness of the needle rod, and the limited packaging accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of LED chip transfer packaging, and in particular to a multi-needle mechanical die-bonding type Mini-LED mass transfer system and a usage method thereof. Background Art

[0002] Currently, with the progress of technology, there has been a mode shift in the display field. Display screens need to have high resolution, high stability, and small size to meet the requirements of applications such as ultra-high-definition display screens, flexible or wearable display screens, augmented reality, and virtual reality. For these applications, traditional display technologies such as liquid crystal displays (LCDs) or organic light-emitting diodes (OLEDs) are not suitable. Compared with traditional LEDs, Mini / Micro LED structures are small and have advantages such as high light extraction efficiency, good current diffusion, low self-heating effect, short response time, low power consumption, and high visible light communication performance. Especially in terms of optoelectronics, Mini / Micro LEDs have limited wavelength shift, high brightness, and high contrast. Most importantly, due to the inorganic characteristics of Mini / Micro LEDs, they have an extremely long service life of more than 10 years and excellent environmental tolerance.

[0003] However, manufacturing a Mini / Micro LED display panel requires transferring tens of millions of chips onto a substrate. The traditional chip transfer technology is based on the pick-and-place method, that is, a moving arm picks up a single chip or a chip array and relocates them to the target substrate. However, as the chip size decreases to the micron level, this method not only has the problem that it is difficult to pick up the chips, but also has low efficiency. Therefore, mass transfer technology has emerged. Among them, the mechanical die-bonding technology has the advantages of low cost and high efficiency. This method uses needles to directly transfer the chips on the blue film to the substrate. However, for this technology, every time a chip is transferred, the needle, the chip, and the substrate need to be aligned, and the movement of the device needs to be frequently started and stopped, which not only reduces the transfer efficiency, but also the generated vibration greatly reduces the packaging accuracy. To improve the efficiency, at present, there is a design of an array of needles, but the needle density is restricted by the thickness of the needle rod and cannot be increased to meet the requirements of different pitches. Summary of the Invention

[0004] Aiming at the above defects, the purpose of the present invention is to propose a multi-needle mechanical die-bonding type Mini-LED mass transfer system and a usage method thereof, so as to solve the problems of low current transfer efficiency, needle density restricted by the thickness of the needle rod, and limited packaging accuracy.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A multi-needle mechanical die-bonding type Mini-LED mass transfer system includes a substrate assembly line, a planar motion platform, and a multi-needle die-bonding device;

[0007] On one side of the planar motion platform close to the multi-needle die bonding device, a scanning camera is provided. A chip carrier is provided on the planar motion platform, and the chip carrier is used to fix the blue film.

[0008] The multi-needle die bonding device includes a die bonding head assembly and a three-axis motion gantry. The die bonding head assembly is fixed at the output end of the three-axis motion gantry and is driven by the three-axis motion gantry. The die bonding head assembly includes a bottom plate and a plurality of sub-die bonding heads. The bottom plate is provided with a needle outlet hole, and the plurality of sub-die bonding heads are distributed around the periphery of the needle outlet hole. Each sub-die bonding head includes a housing, a motor, and a tungsten needle clamping device. The housing is provided with a guide rail, and the tungsten needle clamping device is slidably arranged on the housing along the guide rail. The motor drives the tungsten needle clamping device to move along the guide rail. The tungsten needle clamping device is provided with a tungsten needle. The movement of the tungsten needle clamping device causes the tungsten needle to switch between a first position state and a second position state. When the tungsten needle is in the first position state, the tungsten needle does not pass through the needle outlet hole, and the axis of the tungsten needle is not collinear with the axis of the needle outlet hole. When the tungsten needle switches to the second position state, the tungsten needle passes through the needle outlet hole and acts on the blue film on the chip carrier.

[0009] The substrate assembly line is located on the side of the planar motion platform away from the multi-needle die bonding device. The substrate assembly line includes a transport track, limiters, and negative pressure suction cups. The transport track is used to transport the substrate to the required position. The limiters are located on both sides of the transport track, and the negative pressure suction cups are located in the middle of the transport track. The limiters and the negative pressure suction cups are used to fix the substrate.

[0010] Further, the motor is fixedly installed on the top of the housing. The tungsten needle clamping device passes through the housing. The driving end of the motor is connected to the tungsten needle clamping device. Each sub-die bonding head further includes an elastic member. One end of the elastic member is located below the tungsten needle clamping device, and the other end of the elastic member is fixed inside the housing. The motor drives the tungsten needle clamping device to compress the elastic member downward and move to the second position state, and the elastic member drives the tungsten needle clamping device to return to the first position state upward.

[0011] Further, a slider is provided between the elastic member and the tungsten needle clamping device. The slider is in sliding contact with the elastic member and the tungsten needle clamping device. There are two elastic members, and the two elastic members are connected to both ends of the bottom of the slider.

[0012] Preferably, the crystal piercing head assembly further includes a central crystal piercing head located directly above the needle outlet hole. The central crystal piercing head includes a motor and a central tungsten needle. The motor drives the central tungsten needle to vertically penetrate downward through the needle outlet hole and act on the blue film on the chip carrier, or drives the central tungsten needle to vertically withdraw upward from the needle outlet hole. The axis of the central tungsten needle is collinear with the axis of the needle outlet hole.

[0013] Furthermore, the guide rail is an arc-shaped section guide rail, and several of the sub-crystal piercing heads are arranged in an array; the number of the sub-crystal piercing heads is 4, and the 4 sub-crystal piercing heads are distributed in a cross shape, and the center of the cross and the center of the needle outlet hole are located on the same vertical axis; alternatively, the number of the sub-crystal piercing heads is 8, and the 8 sub-crystal piercing heads are evenly surrounded by the central crystal piercing head, and the 8 sub-crystal piercing heads are distributed in a cross shape on the bottom plate, and the center of the cross shape and the center of the needle outlet hole are located on the same vertical axis.

[0014] Furthermore, the guide rail is a through groove oppositely arranged on both sides of the housing. Guide rods are provided on both sides of the tungsten needle clamping. The axes of the two guide rods are on the same line, and the guide rods are slidably clamped in the guide rail.

[0015] A method of using the above multi-needle mechanical crystal piercing type Mini-LED mass transfer system includes the following steps:

[0016] S1. Substrate preparation: Place the substrate to be processed on the transport track. When it is transported to the crystal piercing position, the transport track stops moving, the stopper pops out, and the substrate is precisely fixed at the crystal piercing position. The negative pressure suction cup rises and presses tightly against the lower surface of the substrate to fix the substrate.

[0017] S2. Chip preparation: Fix the blue film on the chip carrier. The planar motion platform drives the chip carrier to reach under the scanning camera. The scanning camera obtains the positions of all Mini-LED chips through machine vision and stores and records them. After completion, the chip carrier moves above the substrate again.

[0018] S3. Single - area die bonding: The die bonding head assembly is driven by the three - axis moving gantry to the die bonding area to be processed. The die bonding area to be processed contains an m×n dot matrix, which corresponds one - to - one with the chip pads on the substrate and the needle - ejecting positions of the sub - die bonding heads. Select the first point of the dot matrix. According to the recorded chip position, the planar motion platform drives the chip corresponding to this point to the position where the "tungsten needle - chip - chip pad" are in a straight line. The first tungsten needle reaches the second position state under the drive of the corresponding motor to complete the die bonding motion. When the first tungsten needle completes the die bonding motion, the second tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the first tungsten needle switches to the first position state. When the second tungsten needle completes the die bonding motion, the third tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the second tungsten needle switches to the first position state, and so on, to complete the transfer of all chips in the area to be processed.

[0019] S4. Positioning and transfer: After completing the single - area die bonding, the multi - needle die bonding device moves to the next die bonding area to be processed for alignment. After completing the alignment, repeat step S3 to perform die bonding and transfer until die bonding of all the Mini - LED chips is completed.

[0020] Further, in step S3, the planar motion platform drives the chip carrier to perform two - dimensional motion, thereby driving the chips adhered to the blue film to the required position. The movement route of the chip carrier is an "S" - shaped line.

[0021] Preferably, the Mini - LED chip is rectangular, the long - side dimension of the Mini - LED chip is greater than 50μm, and the short - side dimension is greater than 25μm; the pitch between the chip pads is 100 - 1000 microns.

[0022] Preferably, the vacuum degree of the negative - pressure chuck is less than 100Pa.

[0023] The technical solution provided by the present invention may include the following beneficial effects:

[0024] 1. The mass transfer system of this solution uses multiple sub - die bonding heads, and the tungsten needles of these sub - die bonding heads can perform telescopic motion. The motion between the tungsten needles is not affected, so that the needle - ejecting density is not limited by the thickness of the needle rod, adapting to different pitches and effectively improving the chip transfer efficiency.

[0025] 2. In the system usage method of this solution, when performing single - area die bonding, the movement of the planar motion platform is used to replace the movement of the multi - needle die bonding device, reducing the vibration of the device and improving the packaging accuracy. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of an embodiment of the present invention.

[0027] Figure 2 It is a schematic structural diagram of a die head assembly according to an embodiment of the present invention.

[0028] Figure 3 It is a schematic structural diagram of a die head assembly according to an embodiment of the present invention.

[0029] Figure 4 It is a schematic structural diagram of a die head assembly according to another embodiment of the present invention.

[0030] Figure 5 It is a schematic structural diagram of a sub-die head of the present invention.

[0031] Figure 6 It is a schematic structural diagram of an intermediate sub-die head of the present invention.

[0032] Figure 7 It is a schematic structural diagram of an embodiment of the present invention.

[0033] Wherein: die head assembly 1, sub-die head 11, bottom plate 12, three-axis motion gantry 13, housing 111, motor 112, elastic member 113, tungsten needle clamping 114, tungsten needle 115, slider 116, guide rail 1111, guide rod 1141, needle outlet hole 121, scanning camera 21, chip carrier 22, blue film 223, transport track 31, negative pressure suction cup 32, substrate 33, chip pad 341, central die head 14, central tungsten needle 141. Detailed implementation manners

[0034] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation of the present invention.

[0035] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the features defined with "first", "second" may explicitly or implicitly include one or more of such features, used to distinguish and describe features, without order or weight.

[0036] In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0038] A multi-needle mechanical crystal piercing type Mini-LED mass transfer system proposed by this solution includes a substrate production line, a planar motion platform, and a multi-needle crystal piercing device; a scanning camera 21 is provided on one side of the planar motion platform close to the multi-needle crystal piercing device, and a chip carrier 22 is provided on the planar motion platform, and the chip carrier 22 is used to fix the blue film 223.

[0039] The multi-needle crystal piercing device includes a crystal piercing head assembly 1 and a three-axis motion gantry 13. The crystal piercing head assembly 1 is fixed at the output end of the three-axis motion gantry 13, and the crystal piercing head assembly 1 is driven by the three-axis motion gantry 13; the crystal piercing head assembly 1 includes a bottom plate 12 and a plurality of sub-crystal piercing heads 11. The bottom plate 12 is provided with a needle outlet hole 121, and the plurality of sub-crystal piercing heads 11 are distributed around the periphery of the needle outlet hole 121; each sub-crystal piercing head 11 includes a housing 111, a motor 112, and a tungsten needle clamp 114. The housing 111 is provided with a guide rail 1111, and the tungsten needle clamp 114 is slidably arranged along the guide rail 1111 in the housing 111. The motor 112 drives the tungsten needle clamp 114 to move along the guide rail 1111. The tungsten needle clamp 114 is provided with a tungsten needle 115. The movement of the tungsten needle clamp 114 causes the tungsten needle 115 to switch between a first position state and a second position state. When the tungsten needle 115 is in the first position state, the tungsten needle 115 does not pass through the needle outlet hole 121, and the axis of the tungsten needle 115 is not collinear with the axis of the needle outlet hole 121. When the tungsten needle 115 switches to the second position state, the tungsten needle 115 passes through the needle outlet hole 121 and acts on the blue film 223 on the chip carrier 22.

[0040] The substrate production line is located on the side of the planar motion platform away from the multi-needle crystal piercing device. The substrate production line includes a transport track 31, a limiter, and a negative pressure suction cup 32. The transport track 31 is used to transport the substrate 33 to the required position. The limiter is located on both sides of the transport track 31, and the negative pressure suction cup 32 is located in the middle of the transport track 31. The limiter and the negative pressure suction cup 32 are used to fix the substrate 33.

[0041] Specifically, for the efficiency of chip transfer, the mass transfer technology has emerged. Among them, the mechanical die-bonding technology has the advantages of low cost and high efficiency. This method uses a needle to directly transfer the chips on the blue film to the substrate. However, for each chip transfer, the needle, the chip, and the substrate need to be aligned, and the movement of the device needs to be frequently started and stopped, which not only reduces the transfer efficiency, but also the generated vibration greatly reduces the packaging accuracy. To improve the efficiency, there is a design of an array of needles at the current stage. However, the needle density is restricted by the thickness of the needle shaft, and it is impossible to increase the needle density to meet the requirements of different pitches.

[0042] Therefore, a multi-needle mechanical die-bonding type Mini-LED mass transfer system proposed in this solution, as Figures 1 to 3As shown, it includes a substrate assembly line, a planar motion platform, and a multi-needle die bonding device; the multi-needle die bonding device includes a die bonding head assembly 1 and a three-axis motion gantry 13. The die bonding head assembly 1 is fixed on the three-axis motion gantry 13 and is driven by the three-axis motion gantry 13. The die bonding head assembly 1 includes a bottom plate 12 and a number of sub-die bonding heads 11. The bottom plate 12 is provided with a needle outlet hole 121, and the number of sub-die bonding heads 11 are distributed around the outer periphery of the needle outlet hole 121. The sub-die bonding head 11 includes a housing 111, a motor 112, and a tungsten needle clamp 114. The housing 111 is provided with a guide rail 1111, and the tungsten needle clamp 114 is slidably arranged on the housing 111 along the guide rail 1111. The motor 112 drives the tungsten needle clamp 114 to move along the guide rail 1111. The tungsten needle clamp 114 is provided with a tungsten needle 115. The movement of the tungsten needle clamp 114 causes the tungsten needle 115 to switch between a first position state and a second position state. When the tungsten needle 115 is in the first position state, the tungsten needle 115 does not pass through the needle outlet hole 121, and the axis of the tungsten needle 115 is not collinear with the axis of the needle outlet hole 121. The number of tungsten needles 115 do not affect each other. When the tungsten needle 115 switches to the second position state, the tungsten needle 115 passes through the needle outlet hole 121 and acts on the blue film 223 on the chip carrier 22. The number of sub-die bonding heads 11 are provided with the motor 112, and the sub-die bonding heads 11 can operate independently, switching from the first position state to the second position state. The number of tungsten needles 115 move alternately, and the operation of the number of tungsten needles 115 effectively improves the transfer efficiency. When the first tungsten needle 115 is in the second position state for work, the second tungsten needle 115 switches from the first position state to the second position state. When the first tungsten needle 115 finishes working in the second position state, the first tungsten needle 115 switches from the second position state to the first position state, and the second tungsten needle 115 can immediately reach the second position state to perform work. The next tungsten needle 115 switches from the first position state to the second position state, and so on. In this way, the number of tungsten needles 115 do not affect each other, increasing the needle density, shortening the die bonding waiting time, and at the same time being able to adapt to different pitches of the chip pads on the substrate 33, solving the problems of low current transfer efficiency and the needle density being restricted by the thickness of the needle rod.

[0043] A scanning camera 21 is provided on one side of the planar motion platform close to the multi-needle die bonding device. A chip carrier 22 is provided on the planar motion platform. The chip carrier 22 is used to fix the blue film 223. Mini-LED chips are evenly adhered to one side of the blue film 223 away from the multi-needle die bonding device. Chip pads are evenly arranged on the substrate 33. The chip pads are opposite to the Mini-LED chips. During the working process, when die bonding in a single area, mainly the planar motion platform drives the chip to move to a position corresponding to the tungsten needle 115 and the chip pad. The load of the planar motion platform is small, and it is relatively easy to achieve high-frequency and high-speed movement. While the multi-needle die bonding device has a large mass and is greatly restricted in high-frequency and high-speed movement. By the movement of the planar motion platform, the movement frequency of the multi-needle die bonding device is reduced, the vibration of the multi-needle die bonding device is reduced, and the packaging accuracy is improved, solving the problem of limited packaging accuracy.

[0044] Further, the motor 112 is fixedly installed on the top of the housing 111. The tungsten needle clamp 114 passes through the housing 111. The driving end of the motor 112 is connected to the tungsten needle clamp 114. The sub-die bonding head 11 further includes an elastic member 113. One end of the elastic member 113 is located below the tungsten needle clamp 114, and the other end of the elastic member 113 is fixed inside the housing. The motor 112 drives the tungsten needle clamp 114 to compress the elastic member 113 downward and move to the second position state, and the elastic member 113 drives the tungsten needle clamp 114 to move upward to restore the first position state.

[0045] Specifically, as Figure 5 shown, the motor 112 is fixedly installed on the top of the housing 111. The driving end of the motor 112 is connected to the tungsten needle clamp 114, driving the tungsten needle clamp 114 to move along the guide rail 1111. The tungsten needle clamp 114 passes through the housing 111. During the movement of the tungsten needle clamp 114, the housing 111 can improve the stability of the tungsten needle clamp 114, reduce the occurrence of position deviation during the working process, thereby improving the stability of the shape and position accuracy of the tungsten needle 115 and reducing the processing error.

[0046] Preferably, the sub-spinning head 11 further includes an elastic member 113. One end of the elastic member 113 is located below the tungsten needle clamping 114, and the other end of the elastic member 113 is fixed to the housing. The motor 112 drives the tungsten needle clamping 114 to compress the elastic member 113 downward and move to the second position state. The elastic member 113 drives the tungsten needle clamping 114 to recover to the first position state upward. In the sub-spinning head 11, only the motor 112 needs to drive the tungsten needle clamping 114, with a simple structure and convenient operation, reducing the complexity of multi-needle spinning.

[0047] Preferably, the elastic member 113 is a helical spring, which has a compact structure and can generate a large elastic deformation when loaded, converting mechanical work or kinetic energy into deformation energy, and then converting the deformation energy back into mechanical work or kinetic energy after unloading, with high energy conversion efficiency.

[0048] Furthermore, a slider 116 is provided between the elastic member 113 and the tungsten needle clamping 114. The slider 116 is in sliding contact with the elastic member 113 and the tungsten needle clamping 114. There are two elastic members 113, and the two elastic members 113 are connected to both ends of the bottom of the slider 116.

[0049] Specifically, since there is a relative displacement between the tungsten needle clamping 114 and the elastic member 113, a slider 116 is provided between the elastic member 113 and the tungsten needle clamping 114. The slider 116 is in sliding contact with the elastic member 113 and the tungsten needle clamping 114, that is, the elastic member 113 contacts the tungsten needle clamping 114 through the slider 116. The slider 116 transmits the elastic force of the elastic member 113 to the tungsten needle clamping 114, enabling the tungsten needle clamping 114 to smoothly recover to the first position state, avoiding direct contact between the elastic member 113 and the tungsten needle clamping 114, preventing the elastic member 113 from damaging the tungsten needle clamping 114 when there is relative displacement, facilitating later maintenance, and enabling the tungsten needle clamping 114 to move quickly and switch between the first position state and the second position state, improving the flexibility during work.

[0050] There are two elastic members 113, and the two elastic members 113 are connected to both ends of the bottom of the slider 116, which can effectively maintain the balance of the tungsten needle clamping 114 in the horizontal direction and ensure that the tungsten needle clamping 114 can quickly and accurately move to the first position state.

[0051] Preferably, the crystal stabbing head assembly 1 further includes a central crystal stabbing head 14, which is located directly above the needle outlet hole 121. The central crystal stabbing head 14 includes a motor 112 and a central tungsten needle 141. The motor 112 drives the central tungsten needle 141 to vertically penetrate downward through the needle outlet hole 121 and act on the blue film 223 on the chip carrier 22, or drives the central tungsten needle 141 to vertically withdraw upward from the needle outlet hole 121. The axis of the central tungsten needle 141 is collinear with the axis of the needle outlet hole 121.

[0052] Specifically, as Figure 6 shown, the central crystal stabbing head 14 is located directly above the needle outlet hole 121. The central crystal stabbing head 14 includes a motor 112 and a central tungsten needle 141. The motor 112 drives the central tungsten needle 141 to vertically penetrate downward through the needle outlet hole 121 and act on the blue film 223 on the chip carrier 22, or drives the central tungsten needle 141 to vertically withdraw upward from the needle outlet hole 121. The axis of the central tungsten needle 141 is collinear with the axis of the needle outlet hole 121, which can quickly perform the crystal stabbing work, adapt to different arrangement modes, omit the redundant moving process and unnecessary errors, reduce costs, improve the flexibility of the device, and meet the needs of different chip arrangement modes.

[0053] Furthermore, the guide rail 1111 is an arc-shaped section guide rail, and several of the sub-crystal stabbing heads 11 are arranged in an array.

[0054] The number of the sub-crystal stabbing heads 11 is 4, and the 4 sub-crystal stabbing heads 11 are distributed in a cross shape, and the center of the cross and the center of the needle outlet hole 121 are located on the same vertical axis; or, the number of the sub-crystal stabbing heads 11 is 8, and the 8 sub-crystal stabbing heads 11 are evenly surrounded by the central crystal stabbing head 14, and the 8 sub-crystal stabbing heads 11 are distributed in a cross shape on the bottom plate 12, and the center of the cross and the center of the needle outlet hole 121 are located on the same vertical axis.

[0055] Specifically, the guide rail 1111 is an arc-shaped guide rail, and the tungsten needle 115 moves in a curve according to the guide rail 1111. That is, there is not only a vertical movement of stabbing and transferring the Mini-LED chip to the substrate 33, but also a horizontal movement from a position far from the Mini-LED chip to directly above the Mini-LED chip. The guide rail 1111 can be adjusted according to the requirements of die bonding. In the vertical direction, the movement distance of the tungsten needle 115 can transfer the chip to the substrate 33; in the horizontal direction, the tungsten needles 115 do not affect each other in the first position state and reach the second position state corresponding to the chip pads of the substrate 33. The guide rail 1111 is arc-shaped and has good adaptability, can correspond to different spacings of the chip pads of the substrate 33, reduce damage to the chips, and improve the yield rate.

[0056] In the die bonding head assembly 1, several of the sub-die bonding heads 11 are arranged in an array, as Figure 4 shown. The number of the sub-die bonding heads 11 is 4, and the 4 sub-die bonding heads 11 are distributed in a cross shape. The center of the cross and the center of the needle outlet hole 121 are located on the same vertical axis; or, as Figure 2 shown. The number of the sub-die bonding heads 11 is 8, and the 8 sub-die bonding heads 11 are evenly surrounded by the central die bonding head 14. The 8 sub-die bonding heads 11 are distributed in a cross shape on the bottom plate 12. The center of the cross shape and the center of the needle outlet hole 121 are located on the same vertical axis. When in use, the tungsten needle 115 needs to achieve a straight line of "tungsten needle-chip-chip pad". Several of the sub-die bonding heads 11 are arranged in an array, that is, the tungsten needles 115 have corresponded to the chip pads of the substrate 33 one by one. Only the planar motion platform needs to move on the horizontal plane to correspond the Mini-LED chips adhered to the blue film 223 with the chip pads of the substrate 33, and then by driving the corresponding tungsten needles 115, the purpose of chip transfer can be achieved, reducing the movement frequency of the die bonding head assembly 1, improving the accuracy, and the process is rapid, improving the transfer and packaging efficiency.

[0057] Furthermore, the guide rail 1111 is a through groove oppositely arranged on both sides of the housing 111. Guide rods 1141 are provided on both sides of the tungsten needle clamp 114, and the axes of the two guide rods 1141 are on the same line. The guide rods 1141 are slidably clamped in the guide rail 1111.

[0058] Specifically, the guide rails 1111 are through grooves oppositely arranged on both sides of the housing 111. The two sides of the tungsten needle clamping 114 are coaxially provided with guide rods 1141. The guide rods 1141 are slidably clamped in the guide rails 1111. When the tungsten needle 115 is in the first position state or the second position state, the guide rods 1141 are located at the ends of the guide rails 1111. At this time, the guide rails 1111 can limit the movement position of the needle tip, ensuring that the needle tip can accurately complete chip transfer without damaging the chip. The guide rods 1141 can drive the tungsten needle clamping 114 to move along the trajectory of the guide rails 1111, thereby driving the tungsten needle 115 to move along an accurate path, reducing the vibration and deviation during the movement of the tungsten needle 115, enhancing the stability of the system, and ensuring that the plurality of tungsten needles 115 do not affect each other, guaranteeing the needle density, reducing wear to a certain extent, and extending the service life of the device.

[0059] A method of using the above multi-needle mechanical die-bonding type Mini-LED mass transfer system includes the following steps:

[0060] S1. Substrate preparation: Place the substrate 33 to be processed on the transport track 31. When it is transported to the die-bonding position, the transport track 31 stops moving, the stopper pops out, and the substrate 33 is accurately fixed at the die-bonding position. The negative pressure suction cup 32 rises and presses against the lower surface of the substrate 33 to fix the substrate 33.

[0061] S2. Chip preparation: Fix the blue film 223 on the chip carrier 22. The planar motion platform drives the chip carrier 22 to reach under the scanning camera 21. The scanning camera 21 obtains the positions of all Mini-LED chips through machine vision and stores and records them. After completion, the chip carrier 22 moves to above the substrate 33 again.

[0062] S3. Single-area die-bonding: The die-bonding head assembly 1 is driven by the three-axis motion gantry 13 to reach the area to be die-bonded. The area to be die-bonded contains an m×n dot matrix, and the dot matrix corresponds one-to-one to the chip pads 341 of the substrate 33 and the needle positions of the sub-die-bonding heads 11. Select the first point of the dot matrix. According to the recorded chip positions, the planar motion platform drives the chip corresponding to the point to the position where the "tungsten needle-chip-chip pad" are in a straight line. The first tungsten needle 115 reaches the second position state under the drive of the corresponding motor 112 to complete the die-bonding motion. When the first tungsten needle completes the die-bonding motion, the second tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the first tungsten needle switches to the first position state. When the second tungsten needle completes the die-bonding motion, the third tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the second tungsten needle switches to the first position state, and so on, to complete the transfer of all chips in the area to be processed.

[0063] S4. Positioning and transfer: After completing the single - area crystal spiking, the multi - needle crystal spiking device moves to the next area to be crystal - spiked for alignment. After completing the alignment, repeat step S3 to perform crystal spiking transfer until crystal spiking is completed for all the Mini - LED chips.

[0064] This technical solution also proposes a method using the above - mentioned multi - needle mechanical crystal spiking type Mini - LED mass transfer system, which can complete the transfer of Mini - LED chips by using the above - mentioned multi - needle mechanical crystal spiking type Mini - LED mass transfer system. Through the arrangement of several sub - crystal spiking heads 11 and the central crystal spiking head 14, several tungsten needles 115 move according to the guide rail 1111, and no conflict occurs between the tungsten needles 115; the movement of multiple tungsten needles 115 improves the transfer efficiency. When transferring chips in the same area to be processed, only the chip carrier 22 needs to perform planar movement, while the crystal spiking head assembly 1 does not need to move. Compared with the crystal spiking head assembly 1, the load of the planar movement platform is low, reducing the movement frequency of the crystal spiking head assembly 1, which can effectively improve the packaging accuracy and solve the problems of low transfer efficiency and limited packaging accuracy of Mini - LED chips at the present stage.

[0065] Further, in step S3, the planar movement platform drives the chip carrier 22 to perform two - dimensional movement, thereby driving the chips adhered to the blue film 223 to move to the required position. The movement route of the chip carrier 22 is an "S" - shaped line.

[0066] Specifically, for the Mini - LED chips evenly distributed on the blue film 223, the planar movement platform drives the chip corresponding to the first point to move to the position where the "tungsten needle - chip - chip pad" are in a straight line (as Figure 7 shown). After completing the transfer of the chips at the corresponding points, the planar movement platform drives the chip carrier 22 to move. After completing the transfer of the chip pads on the substrate 33 in the column where the point is located, it drives the chip to move to the point in another column adjacent to the last point in this column to continue the chip transfer. The overall is an "S" - shaped line, reducing the moving distance of the planar movement platform and improving the transfer speed.

[0067] Preferably, the Mini - LED chip is rectangular, the long - side dimension of the Mini - LED chip is greater than 50μm, and the short - side dimension is greater than 25μm; the pitch between the chip pads 341 is 100 - 1000 microns.

[0068] Specifically, the long side dimension of the Mini-LED chip is greater than 50 μm, and the short side dimension is greater than 25 μm. If the size of the Mini-LED chip is smaller than the above range, it is not suitable to use the mechanical die-bonding method and is prone to damage the chip. The distance between the chip pads 341 should be greater than the size of the chip. The needle tip size of the tungsten needle 115 is slightly larger than the chip size. The spacing of the chip pads 341 is 100 - 1000 microns. 100 - 1000 microns is the spacing range used during operation. 100 microns is limited by the size of the Mini-LED chip itself. If the spacing of the chip pads 341 is greater than 1000 microns, the movement distance of the planar motion platform increases, and the time consumed becomes longer, thereby affecting the transfer efficiency. Controlling it between 100 - 1000 microns can adapt to the Mini-LED chip while minimizing the impact on the transfer rate.

[0069] Preferably, the vacuum degree of the negative pressure chuck 32 is less than 100 Pa. When performing mechanical die-bonding, the substrate 33 needs to receive the high-frequency impact of the tungsten needle 115. Therefore, a relatively large negative pressure is required for fixation to prevent the substrate 33 from shifting.

[0070] The present invention will be further described below in conjunction with embodiments.

[0071] Embodiment 1

[0072] As Figure 1 shown, a multi-needle mechanical die-bonding type Mini-LED mass transfer system includes a substrate assembly line, a planar motion platform, and a multi-needle die-bonding device; a scanning camera 21 is provided on one side of the planar motion platform close to the multi-needle die-bonding device, and a chip carrier 22 is provided on the planar motion platform. The chip carrier 22 is used to fix the blue film 223.

[0073] The multi-needle crystal stabbing device includes a crystal stabbing head assembly 1 and a three-axis moving gantry 13. The crystal stabbing head assembly 1 is fixed on the three-axis moving gantry 13 and is driven by the three-axis moving gantry 13. The crystal stabbing head assembly 1 includes a bottom plate 12 and a number of sub-crystal stabbing heads 11. The bottom plate 12 is provided with a needle outlet hole 121, and the number of sub-crystal stabbing heads 11 are distributed around the outer periphery of the needle outlet hole 121. The sub-crystal stabbing head 11 includes a housing 111, a motor 112 and a tungsten needle clamp 114. The housing 111 is provided with a guide rail 1111. The tungsten needle clamp 114 is slidably arranged on the housing 111 along the guide rail 1111. The motor 112 drives the tungsten needle clamp 114 to move along the guide rail 1111. The tungsten needle clamp 114 is provided with a tungsten needle 115. The movement of the tungsten needle clamp 114 causes the tungsten needle 115 to switch between a first position state and a second position state. When the tungsten needle 115 is in the first position state, the tungsten needle 115 does not pass through the needle outlet hole 121, and the axis of the tungsten needle 115 is not collinear with the axis of the needle outlet hole 121. When the tungsten needle 115 switches to the second position state, the tungsten needle 115 passes through the needle outlet hole 121 and acts on the blue film 223 on the chip carrier 22.

[0074] The substrate assembly line is located on the side of the planar motion platform away from the multi-needle crystal stabbing device. The substrate assembly line includes a transport track 31, a limiter and a negative pressure suction cup 32. The transport track 31 is used to transport the substrate 33 to the required position. The limiter is located on both sides of the transport track 31, and the negative pressure suction cup 32 is located in the middle of the transport track 31. The limiter and the negative pressure suction cup 32 are used to fix the substrate 33.

[0075] The method of using the above multi-needle mechanical crystal stabbing type Mini-LED mass transfer system includes the following steps:

[0076] S1. Substrate preparation: Place the substrate 33 to be processed on the transport track 31. When it is transported to the crystal stabbing position, the transport track 31 stops moving, the limiter pops out, and the substrate 33 is precisely fixed at the crystal stabbing position. The negative pressure suction cup 32 rises and adheres to the lower surface of the substrate 33 to fix the substrate 33.

[0077] S2. Chip preparation: Fix the blue film 223 on the chip carrier 22. The planar motion platform drives the chip carrier 22 to reach under the scanning camera 21. The scanning camera 21 obtains the positions of all Mini-LED chips through machine vision and stores the records. After completion, the chip carrier 22 moves to above the substrate 33.

[0078] S3. Single - area die bonding: The die bonding head assembly 1 is driven by the three - axis moving gantry 13 to reach the die bonding area to be processed. The die bonding area to be processed contains a 3×3 dot matrix, and the dot matrix corresponds one - to - one with the chip pads 341 of the substrate 33 and the needle - out positions of the sub - die bonding heads 11. Select the first point of the dot matrix. According to the recorded chip position, the planar motion platform drives the chip corresponding to this point to the position where the "tungsten needle - chip - chip pad" are in a straight line. The first tungsten needle 115 reaches the second position state under the drive of the corresponding motor 112 to complete the die bonding motion. When the first tungsten needle completes the die bonding motion, the second tungsten needle switches to the second position state under the drive of the corresponding motor, and at this time, the first tungsten needle switches to the first position state. When the second tungsten needle completes the die bonding motion, the third tungsten needle switches to the second position state under the drive of the corresponding motor, and at this time, the second tungsten needle switches to the first position state, and so on, to complete the transfer of all chips in the area to be processed.

[0079] S4. Positioning and transfer: After completing the single - area die bonding, the multi - needle die bonding device moves to the next die bonding area to be processed for alignment. After completing the alignment, repeat step S3 to perform die bonding and transfer until die bonding is completed for all the Mini - LED chips.

[0080] Embodiment 2

[0081] A multi - needle mechanical die - bonding type Mini - LED mass transfer system includes a substrate assembly line, a planar motion platform, and a multi - needle die - bonding device. A scanning camera 21 is provided on one side of the planar motion platform close to the multi - needle die - bonding device, and a chip carrier 22 is provided on the planar motion platform. The chip carrier 22 is used to fix the blue film 223.

[0082] The multi-needle crystal piercing device includes a crystal piercing head assembly 1 and a three-axis moving gantry 13. The crystal piercing head assembly 1 is fixed on the three-axis moving gantry 13 and is driven by the three-axis moving gantry 13. The crystal piercing head assembly 1 includes a bottom plate 12 and a plurality of sub-crystal piercing heads 11. The bottom plate 12 is provided with a needle outlet hole 121, and the plurality of sub-crystal piercing heads 11 are distributed around the outer periphery of the needle outlet hole 121. The sub-crystal piercing head 11 includes a housing 111, a motor 112, and a tungsten needle clamp 114. The housing 111 is provided with a guide rail 1111. The tungsten needle clamp 114 is slidably arranged on the housing 111 along the guide rail 1111. The motor 112 drives the tungsten needle clamp 114 to move along the guide rail 1111. The tungsten needle clamp 114 is provided with a tungsten needle 115. The movement of the tungsten needle clamp 114 causes the tungsten needle 115 to switch between a first position state and a second position state. When the tungsten needle 115 is in the first position state, the tungsten needle 115 does not pass through the needle outlet hole 121, and the axis of the tungsten needle 115 is not collinear with the axis of the needle outlet hole 121. When the tungsten needle 115 switches to the second position state, the tungsten needle 115 passes through the needle outlet hole 121 and acts on the blue film 223 on the chip carrier 22.

[0083] The substrate assembly line is located on the side of the planar motion platform away from the multi-needle crystal piercing device. The substrate assembly line includes a transport track 31, a limiter, and a negative pressure chuck 32. The transport track 31 is used to transport the substrate 33 to the required position. The limiter is located on both sides of the transport track 31, and the negative pressure chuck 32 is located in the middle of the transport track 31. The limiter and the negative pressure chuck 32 are used to fix the substrate 33.

[0084] The method of using the above multi-needle mechanical crystal piercing type Mini-LED mass transfer system includes the following steps:

[0085] S1. Substrate preparation: Place the substrate 33 to be processed on the transport track 31. When it is transported to the crystal piercing position, the transport track 31 stops moving, the limiter pops out, and the substrate 33 is precisely fixed at the crystal piercing position. The negative pressure chuck 32 rises and adheres to the lower surface of the substrate 33 to fix the substrate 33.

[0086] S2. Chip preparation: Fix the blue film 223 on the chip carrier 22. The planar motion platform drives the chip carrier 22 to reach under the scanning camera 21. The scanning camera 21 obtains the positions of all Mini-LED chips through machine vision and stores the records. After completion, the chip carrier 22 moves to above the substrate 33.

[0087] S3. Single-area crystal piercing: The crystal piercing head assembly 1 is driven by the three-axis motion gantry 13 to reach the area to be pierced, and the area to be pierced contains a 2×2 dot matrix, and the dot matrix corresponds one-to-one to the chip pad 341 of the substrate 33 and the needle outlet position of the sub-crystal piercing head 11; the first point of the dot matrix is selected, and according to the recorded chip position, the planar motion platform drives the chip corresponding to the point to move to the position of "tungsten needle-chip-chip pad" three points and one line, and the first tungsten needle 115 reaches the second position state under the drive of the corresponding motor 112 to complete the crystal piercing movement. When the first tungsten needle completes the crystal piercing movement, the second tungsten needle switches to the second position state under the drive of the corresponding motor, and at this time the first tungsten needle switches to the first position state, and when the second tungsten needle completes the crystal piercing movement, the third tungsten needle switches to the second position state under the drive of the corresponding motor, and at this time the second tungsten needle switches to the first position state, and so on, to complete the transfer of all chips in the area to be processed.

[0088] S4, positioning transfer: After completing the crystallization of a single area, the multi-needle crystallization device moves to the next area to be crystallized for alignment. After completing the alignment, step S3 is repeated to perform crystallization transfer until all the Mini-LED chips are crystallized.

[0089] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A multi-needle mechanical crystal piercing type Mini-LED mass transfer system, characterized in that: It includes a substrate production line, a planar motion platform, and a multi-needle die bonding device; A scanning camera is provided on one side of the planar motion platform close to the multi-needle die bonding device. A chip carrier is provided on the planar motion platform, and the chip carrier is used to fix the blue film; The multi-needle die bonding device includes a die bonding head assembly and a three-axis motion gantry. The die bonding head assembly is fixed to the output end of the three-axis motion gantry and is driven by the three-axis motion gantry. The die bonding head assembly includes a bottom plate and a number of sub-die bonding heads. The bottom plate is provided with a needle outlet hole, and a number of the sub-die bonding heads are distributed around the periphery of the needle outlet hole. The sub-die bonding head includes a housing, a motor, an elastic member, and a tungsten needle clamp. The housing is provided with a guide rail. The driving end of the motor is connected to the tungsten needle clamp. The tungsten needle clamp passes through the housing and is slidably arranged on the housing along the guide rail. The motor is fixedly installed on the top of the housing. The motor drives the tungsten needle clamp to move along the guide rail. The tungsten needle clamp is provided with a tungsten needle. The movement of the tungsten needle clamp causes the tungsten needle to switch between a first position state and a second position state. When the tungsten needle is in the first position state, the tungsten needle does not pass through the needle outlet hole, and the axis of the tungsten needle is not collinear with the axis of the needle outlet hole. When the tungsten needle switches to the second position state, the tungsten needle passes through the needle outlet hole and acts on the blue film on the chip carrier; One end of the elastic member is located below the tungsten needle clamp, and the other end of the elastic member is fixed inside the housing. The motor drives the tungsten needle clamp to compress the elastic member downward and move to the second position state, and the elastic member drives the tungsten needle clamp to return to the first position state upward; The substrate production line is located on one side of the planar motion platform away from the multi-needle die bonding device. The substrate production line includes a transport track, a limiter, and a negative pressure suction cup. The transport track is used to transport the substrate to the required position. The limiter is located on both sides of the transport track, and the negative pressure suction cup is located in the middle of the transport track. The limiter and the negative pressure suction cup are used to fix the substrate.

2. The multi-needle mechanical crystal piercing type Mini-LED mass transfer system according to claim 1, wherein: A slider is provided between the elastic member and the tungsten needle clamp. The slider is in sliding contact with the elastic member and the tungsten needle clamp. There are two elastic members, and the two elastic members are connected to both ends of the bottom of the slider.

3. The multi-needle mechanical crystal piercing type Mini-LED mass transfer system according to claim 1, characterized in that: The die bonding head assembly further includes a central die bonding head. The central die bonding head is located directly above the needle outlet hole. The central die bonding head includes a motor and a central tungsten needle. The motor drives the central tungsten needle to vertically pass through the needle outlet hole and act on the blue film on the chip carrier, or drives the central tungsten needle to vertically withdraw from the needle outlet hole. The axis of the central tungsten needle is collinear with the axis of the needle outlet hole.

4. A multi-needle mechanical crystal stabbing type Mini-LED mass transfer system according to claim 3, characterized in that: The guide rail is an arc-shaped section guide rail, and a number of the sub-die bonding heads are arranged in an array; The number of the sub-spike crystal heads is 4, and the 4 sub-spike crystal heads are distributed in a cross shape, and the center of the cross and the center of the needle outlet hole are located on the same vertical axis; or, the number of the sub-spike crystal heads is 8, and the 8 sub-spike crystal heads are evenly surrounded around the center spike crystal head, and the 8 sub-spike crystal heads are distributed in a cross shape on the bottom plate, and the center of the cross and the center of the needle outlet hole are located on the same vertical axis.

5. A multi-needle mechanical crystal piercing type Mini-LED mass transfer system according to claim 4, characterized in that: The guide rail is a through groove oppositely arranged on both sides of the housing. Guide rods are arranged on both sides of the tungsten needle clamping. The axes of the two guide rods are on the same line, and the guide rods are slidably clamped in the guide rail.

6. A method for using a multi-needle mechanical die-bonding type Mini-LED mass transfer system according to any one of claims 1-5, characterized in that, It includes the following steps: S1. Substrate preparation: Place the substrate to be processed on the transport track. When it is transported to the die bonding position, the transport track stops moving, the stopper pops out, and the substrate is precisely fixed at the die bonding position. The negative pressure suction cup rises and adheres to the lower surface of the substrate to fix the substrate. S2. Chip preparation: Fix the blue film on the chip carrier. The planar motion platform drives the chip carrier to reach under the scanning camera. The scanning camera obtains the positions of all Mini-LED chips through machine vision and stores the records. After completion, the chip carrier moves above the substrate again. S3. Single-area die bonding: The die bonding head assembly is driven by the three-axis motion gantry to reach the area to be die bonded. The area to be die bonded contains an m×n dot matrix, and the dot matrix corresponds one-to-one to the chip pads on the substrate and the needle outlet positions of the sub-spike crystal heads. Select the first point of the dot matrix. According to the recorded chip positions, the planar motion platform drives the chip corresponding to the point to the position where "tungsten needle-chip-chip pad" are in a straight line. The first tungsten needle reaches the second position state under the drive of the corresponding motor to complete the die bonding motion. When the first tungsten needle completes the die bonding motion, the second tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the first tungsten needle switches to the first position state. When the second tungsten needle completes the die bonding motion, the third tungsten needle switches to the second position state under the drive of the corresponding motor. At this time, the second tungsten needle switches to the first position state, and so on, to complete the transfer of all chips in the area to be processed. S4. Positioning transfer: After completing the single-area die bonding, the multi-needle die bonding device moves to the next area to be die bonded for alignment. After completion of alignment, repeat step S3 to perform die bonding transfer until die bonding of all the Mini-LED chips is completed.

7. The method of using a multi-needle mechanical crystal piercing type Mini-LED mass transfer system according to claim 6, characterized in that: In step S3, the planar motion platform drives the chip carrier to perform two-dimensional motion, and further drives the chips adhered to the blue film to move to the required positions. The movement route of the chip carrier is an "S" shaped line.

8. The usage method of a multi-needle mechanical crystal stabbing type Mini-LED mass transfer system according to claim 6, characterized in that: The Mini-LED chip is rectangular. The long side dimension of the Mini-LED chip is greater than 50 μm, and the short side dimension is greater than 25 μm; the distance between the chip pads is 100 - 1000 microns.

9. The method of using a multi-needle mechanical crystal piercing type Mini-LED mass transfer system according to claim 6, characterized in that: The vacuum degree of the negative pressure suction cup is less than 100 Pa.

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