An angle correction apparatus for LED chip packaging

Abstract

The present application relates to the technical field of semiconductor manufacturing, and particularly relates to an angle correction device for LED chip packaging, which comprises a rack, a packaging table for placing chips, a mechanical arm for grabbing and moving the chips, a visual sensor for detecting the positions of the chips, a suction nozzle rod assembly, an inner side and an outer side of the suction nozzle rod assembly are respectively provided with an axial through vacuum channel, a vacuum pump for applying positive and negative air pressure to the vacuum channel, and a bottom end of the suction nozzle rod assembly constitutes a vacuum suction nozzle for adsorbing the chips. The phase change medium is melted into liquid by heating of the temperature control unit, and flows into the capillary channel under the action of gravity. Then, when the liquid drops to the surface of the chip, the temperature control unit refrigerates to make the phase change medium solidify on the surface of the chip to form a plurality of mushroom-shaped solid metal micro anchor points, and the chip is cold-welded and locked with the end face of the vacuum suction nozzle as a rigid body, so that the micro sliding of the chip caused by insufficient friction during correction rotation is fundamentally eliminated.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to an angle correction device for LED chip packaging. Background Technology

[0002] LED chips are semiconductor devices that can convert electrical energy into light. They are the core light source for various lighting and display products. In the LED chip packaging process, the chip needs to be picked up from the blue film and accurately mounted onto the substrate. However, the initial posture of the chip on the blue film has random angular deviations. Therefore, its spatial angle must be accurately corrected before mounting. The equipment that performs this function is the LED chip packaging angle correction equipment. It obtains the actual posture of the chip through visual inspection and then the motion mechanism completes the angle compensation to ensure mounting accuracy.

[0003] Currently, mainstream calibration mechanisms use vacuum adsorption to fix the chip, relying on end-face friction to resist rotational inertia. However, with the miniaturization of chips, the adsorption area is reduced, resulting in a sharp drop in friction. When rotating to adjust the chip position, the tangential inertial force generated between the nozzle end face and the chip is very likely to exceed the friction limit, causing microscopic slippage of the chip. This leads to distortion of the calibration angle, scratches on the chip electrodes, and repeated oscillations in the visual closed-loop calibration, which slows down the cycle time. Therefore, this application proposes an angle calibration device for LED chip packaging. Summary of the Invention

[0004] The purpose of this invention is to address the problems of chip adsorption slippage and correction distortion and out-of-control in the background technology, and to propose an angle correction device for LED chip packaging.

[0005] The technical solution of this invention: An angle correction device for LED chip packaging, comprising a frame, a packaging stage for placing chips, a robotic arm for gripping and moving chips, and a vision sensor for detecting chip position, further comprising: The nozzle rod assembly has axially penetrating vacuum channels on its inner and outer sides, and a vacuum pump that applies positive and negative air pressure to the vacuum channels. The bottom end of the nozzle rod assembly forms a vacuum nozzle for adsorbing chips. A liquid storage chamber is disposed within the suction rod assembly and surrounds the vacuum channel; A phase change medium is contained within the liquid storage cavity; A temperature control unit is thermally coupled to the liquid storage cavity and switches between cooling and heating modes. Multiple capillary channels are formed at the lower end of the nozzle rod assembly and inside the vacuum nozzle. The inlet of the capillary channel is connected to the liquid storage cavity, and the outlet of the capillary channel opens at the end face of the vacuum nozzle. A pressure generating device, connected to the liquid storage chamber, is used to apply positive pressure to drive the phase change medium to flow out through the capillary channel, and to apply negative pressure to draw it back. In the cooling mode, positive pressure is applied, causing the phase change medium to seep out and solidify between the back of the chip and the vacuum nozzle to form a temporary lock. In the heating mode, negative pressure is applied, causing the solidified phase change medium to melt and be actively drawn back, thus releasing the chip.

[0006] Optionally, the suction rod assembly includes a vacuum inner tube, a heat insulation sleeve, a liquid storage chamber outer shell, and an outer protective tube arranged coaxially from the inside to the outside. The vacuum channel is formed inside the vacuum inner tube, and the liquid storage chamber is formed between the outer wall of the heat insulation sleeve and the inner wall of the liquid storage chamber outer shell. The heat insulation sleeve is used to block the heat or cold generated by the temperature control unit from being conducted to the vacuum channel.

[0007] Optionally, the phase change medium is a eutectic liquid metal alloy with a melting point between 40°C and 60°C.

[0008] Optionally, the temperature control unit includes at least one thermoelectric cooler and a temperature sensor; the working end face of the thermoelectric cooler is in contact with the vacuum nozzle and the outer shell of the liquid storage chamber, and cooling and heating are achieved by switching the direction of current.

[0009] Optionally, the pressure generating device consists of a piezoelectric micro diaphragm pump, a connecting pipe, and a two-position three-way micro solenoid valve. The piezoelectric micro diaphragm pump and the two-position three-way micro solenoid valve are both installed on the outside of the outer protective pipe. The piezoelectric micro diaphragm pump is connected to the liquid storage chamber through the connecting pipe.

[0010] Optionally, the outer periphery of the vacuum nozzle is provided with an annular groove, and the outlets of all capillary channels open into the annular groove to accommodate and confine the seeping liquid phase change medium.

[0011] Optionally, a rigid porous support plate is provided between the upper part of the liquid storage cavity and the connecting pipe, and a gas-permeable liquid-blocking membrane is provided at the bottom end of the rigid porous support plate. The gas-permeable liquid-blocking membrane is used to allow gas to pass through while preventing the liquid phase change medium from passing through.

[0012] Optionally, the outlet of the capillary channel is provided with a rubber ring, and multiple sets of guide components are provided on the outside of the rubber ring. The guide components include a guide plate, a buffer block, a pair of guide rods, a connecting plate, and a T-shaped plate. The rubber ring expands and slides along the annular groove. The guide plate is located around the vacuum nozzle. The buffer block is fixed to the bottom end of the guide plate. The pair of guide rods are both fixed to the outside of the rubber ring and slide through the guide plate. The connecting plate is fixed to the outside of the outer protective tube. The T-shaped plate is fixed to the guide plate, and the end of the T-shaped plate away from the guide plate is slidably connected to the inside of the connecting plate.

[0013] Optionally, a side plate is fixedly connected to the top of the connecting plate, and a spring is fixedly connected between the side plate and the guide plate.

[0014] Optionally, the lower edge of the buffer block is lower than the vacuum nozzle in the free state.

[0015] Compared with the prior art, this application includes at least one of the following beneficial technical effects: This invention uses a temperature control unit to heat and melt the phase change medium into a liquid, which then flows into a capillary channel under gravity. When the liquid drips onto the chip surface, the temperature control unit cools it, causing the phase change medium to solidify on the chip surface, forming multiple mushroom-shaped solid metal micro-anchors. These micro-anchors then cold-weld the chip to the vacuum nozzle end face, securing it as a rigid body. This fundamentally eliminates the microscopic slippage of the chip caused by insufficient friction during calibration rotation, ensuring the accuracy of angle calibration and the integrity of the chip surface. After calibration, the temperature control unit heats and melts the liquid phase change medium, and a pressure generating device applies negative pressure to actively draw the liquid phase change medium back into the storage cavity, achieving clean and damage-free release of the chip. Furthermore, by using a liquid phase change medium, when targeting uneven chip surfaces, it can adaptively fill micro-depressions and form a rigid connection across the entire surface after solidification. This avoids the air leakage problem caused by the poor fit between the traditional vacuum nozzle and the uneven chip, and enhances the adsorption reliability and connection uniformity of the chip during the calibration process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an angle correction device for LED chip packaging. Figure 2 A schematic diagram of the structure of the robotic arm and vision sensor; Figure 3 This is a partial structural schematic diagram of an angle correction device for LED chip packaging. Figure 4 A schematic diagram of the structure of a vacuum pump and a rigid porous support plate; Figure 5 A schematic diagram of a piezoelectric miniature diaphragm pump and a two-position three-way miniature solenoid valve; Figure 6 A partial planar schematic diagram of an angle correction device for LED chip packaging. Figure 1 ; Figure 7 A partial planar schematic diagram of an angle correction device for LED chip packaging. Figure 2 ; Figure 8 This is a schematic diagram of the structure of the rubber ring and the spring.

[0017] Reference numerals: 1. Suction nozzle rod assembly; 11. Vacuum inner tube; 12. Heat insulation sleeve; 13. Liquid storage chamber outer shell; 14. Outer protective tube; 111. Vacuum channel; 112. Vacuum suction nozzle; 113. Liquid storage chamber; 114. Phase change medium; 115. Annular groove; 116. Vacuum pump; 2. Temperature control unit; 21. Thermoelectric cooler; 22. Temperature sensor; 222. Capillary channel; 3. Pressure generating device; 31. Piezoelectric miniature diaphragm pump; 32. Connecting pipe; 33. Two-position three-way miniature solenoid valve; 41. Rigid porous support plate; 42. Air-permeable liquid-resistant membrane; 51. Rubber ring; 52. Guide plate; 53. Buffer block; 54. Guide rod; 55. Connecting plate; 56. T-shaped plate; 61. Side plate; 62. Spring; 71. Rack; 72. Packaging stage; 73. Robotic arm; 74. Vision sensor. Detailed Implementation

[0018] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 , Figure 2 and Figure 3As shown, the present invention proposes an angle correction device for LED chip packaging, including a frame 71, a packaging stage 72 for placing chips, a robotic arm 73 for gripping and moving chips, and a vision sensor 74 for detecting chip position. The frame 71 serves as the supporting body, providing a stable mounting foundation for the entire correction device. The packaging stage 72 is used to support the substrate or bracket to be packaged, providing a working plane for precise positioning of the chip. The robotic arm 73 is responsible for driving the chip to perform three-axis spatial movement between the pick-up station, the correction station, and the mounting station. The vision sensor 74 acquires the chip's posture image in real time and calculates the angle deviation data for use by the control system.

[0022] As one implementation method, such as Figure 3 - Figure 7 As shown, the angle correction device also includes a nozzle rod assembly 1. The nozzle rod assembly 1 has axially penetrating vacuum channels 111 on its inner and outer sides, and a vacuum pump 116 that applies positive and negative pressure to the vacuum channels 111. The vacuum channels 111 are penetrating along the central axis of the nozzle rod assembly 1. During the pickup phase, the vacuum pump 116 generates negative pressure. The bottom end of the nozzle rod assembly 1 forms a vacuum nozzle 112 for adsorbing the chip, creating suction at the end face of the vacuum nozzle 112 to initially pick up and hold the chip from the blue film. During the release phase, the vacuum pump 116 can switch to a slightly positive pressure to assist the chip in smoothly detaching from the nozzle end face and completing the mounting. The vacuum nozzle 112, as the end-effector that directly contacts the chip, has its end face precisely ground to ensure flatness. Inside the nozzle rod assembly 1, a liquid storage chamber 113 is also provided. The liquid storage chamber 113 is arranged in a ring-shaped spatial layout, surrounding the central vacuum channel 111. This arrangement makes full use of the radial space inside the nozzle rod assembly 1 without affecting the normal operation of the central vacuum circuit. The liquid storage chamber 113 contains a phase change medium 114. The phase change medium 114 is housed within the liquid storage chamber 113. The preferred material for the phase change medium 114 is a eutectic liquid metal alloy with a melting point between 40°C and 60°C. This melting point range is selected to be above room temperature and below the temperature tolerance of electronic components. This ensures that the medium can solidify on its own or melt with only slight heating when it stops working at room temperature, and will not damage the equipment due to excessively high temperatures. Eutectic liquid metal alloys, such as gallium indium tin alloy, have the characteristics of small volume change during solidification and non-wetting of chip materials, ensuring reliable solidification connection and no residue after release.

[0023] Furthermore, such as Figure 4 - Figure 7As shown, the angle correction device also includes a temperature control unit 2 and multiple capillary channels 222. The temperature control unit 2 is thermally coupled to the liquid storage chamber 113. The temperature control unit 2 can adjust the temperature inside the liquid storage chamber 113 to achieve efficient heat transfer and switch between cooling and heating modes. When chip locking is required, the temperature control unit 2 first heats the internal temperature of the liquid storage chamber 113, causing the phase change medium 114 to completely melt into a liquid. Multiple capillary channels 222 are formed at the lower end of the nozzle rod assembly 1 and inside the vacuum nozzle 112. The inlet of the capillary channel 222 is connected to the liquid storage chamber 113. At this time, the liquid phase change medium 114 will flow into the interior of the multiple capillary channels 222 under the action of gravity. The outlet of the capillary channel 222 opens on the end face of the vacuum nozzle 112. The outlet is located on the end face of the vacuum nozzle 112, which can guide the liquid inside the capillary channel 222 to the contact area on the back of the chip. It should be noted that the phase change medium 114 is a surface permeable inert gas permeable (SPC) medium. The phase change medium 114 is a eutectic liquid metal alloy that has undergone a phase change treatment. The capillary channel 222 has stainless steel as its wall material, so the phase change medium 114 exhibits non-wetting characteristics towards the capillary channel 222, with a contact angle greater than 90 degrees. Furthermore, the inner diameter of the capillary channel 222 is extremely small, between 50 and 200 micrometers. Therefore, the phase change medium 114 will not flow into the interior of the capillary channel 222 before it is completely melted at room temperature. Subsequently, the temperature control unit 2 switches to cooling mode, rapidly removing heat and causing the phase change medium 114 to cool and solidify. At this point, the solidified phase change medium... The phase change medium 114 has multiple "mushroom-shaped" solid metal micro-anchor points on the chip surface, which tightly "cold weld" the chip and the end face of the vacuum nozzle 112 into a rigid body without gaps. The solidified phase change medium 114 locks the vacuum nozzle 112 and the chip together firmly, which effectively avoids the situation where the tangential inertial force generated between the end face of the vacuum nozzle 112 and the chip can easily exceed the friction limit when the robotic arm 73 rotates the vacuum nozzle 112 to adjust the chip position, thus preventing the chip from micro-slipping. The use of phase change medium 114 to assist in chip connection in this embodiment also brings another effect: when the phase change medium 114 is in a liquid state, it can adaptively fill the chip surface when it is applied to an uneven chip surface, and form a rigid connection over the entire area after solidification. This avoids the situation where the vacuum nozzle 112 is not able to fit tightly when it is applied to an uneven chip, resulting in air leakage. When it is necessary to release the lock, the temperature control unit 2 switches to the heating mode and quickly inputs heat to melt the solid phase change medium 114. The switching between the two modes can be completed by changing the direction of the current. The response speed is extremely fast and meets the requirements of high-speed production cycle.

[0024] Furthermore, such as Figure 4 , Figure 5 and Figure 7As shown, in order to drive the phase change medium 114 to flow between the end faces of the liquid storage chamber 113 and the vacuum nozzle 112, the angle correction device also includes a pressure generating device 3. The pressure generating device 3 is connected to the liquid storage chamber 113 and is used to apply positive pressure to drive the phase change medium 114 to flow out through the capillary channel 222, and to apply negative pressure to draw it back. The pressure generating device 3 indirectly drives the flow direction of the liquid phase change medium 114 by changing the gas pressure. When positive pressure is applied, the gas pushes the liquid level down, accelerating and forcing the liquid phase change medium 114 to be squeezed out along the capillary channel 222 towards the end face of the vacuum nozzle 112, thereby adhering to the chip. When negative pressure is applied, the gas suction actively draws the liquid phase change medium 114 from the chip surface back into the storage cavity through the capillary channel 222. It should be noted that the phase change medium 114 flowing on the chip surface has been inertly treated, so an inert oxide film is generated on the surface of the phase change medium 114. This makes the phase change medium 114 exist on the chip surface in the form of a ball, which is very easy to be sucked away and will not leave a mark on the chip surface. Subsequently, when the phase change medium 114 has completely returned to the inside of the storage cavity 113, the pressure generating device 3 maintains the gas pressure balance inside the storage cavity 113, further preventing the phase change medium 114 from accidentally flowing into the inside of the capillary channel 222. Through the above structural design, positive pressure is applied in the cooling mode, the phase change medium 114 seeps out and solidifies between the back of the chip and the vacuum nozzle 112 to form a temporary lock. In the heating mode, negative pressure is applied, the solidified phase change medium 114 melts and is actively drawn back, completing the chip release. The fixing form of the chip in the calibration process is changed from friction constraint to material connection, fundamentally eliminating the possibility of slippage.

[0025] Among them, such as Figure 5 and Figure 6 As shown, the outer periphery of the vacuum nozzle 112 is provided with an annular groove 115. The outlets of all capillary channels 222 open into the annular groove 115 to accommodate and confine the seeping liquid phase change medium 114. When the liquid is drawn back into the capillary channel 222, the arc-shaped concave structure of the annular groove 115 can guide and collect the liquid. Even if some media is not completely drawn back due to factors such as fluid dynamics or surface tension, the droplets remaining in the higher area of ​​the annular groove 115 will flow down the arc under the action of gravity and eventually flow into the outlet of the capillary channel 222 and be completely recovered.

[0026] As one implementation method, such as Figure 4 , Figure 6 and Figure 7As shown, the suction rod assembly 1 includes a vacuum inner tube 11, a heat insulation sleeve 12, a liquid storage chamber outer shell 13, and an outer protective tube 14 arranged coaxially from the inside to the outside. The vacuum channel 111 is formed inside the vacuum inner tube 11. The innermost vacuum inner tube 11 is dedicated to the vacuum adsorption gas path, ensuring that the gas path is independent and clean. The liquid storage chamber 113 is formed between the outer wall of the heat insulation sleeve 12 and the inner wall of the liquid storage chamber outer shell 13. The heat insulation sleeve 12 is used to block the heat or cold generated by the temperature control unit 2 from being conducted to the vacuum channel 111. The outer wall directly receives the heat from the temperature control unit 2, resulting in a short heat transfer path and high efficiency. The middle heat insulation sleeve 12 is made of a low thermal conductivity material such as zirconia ceramic, which serves as a thermal barrier to prevent the temperature control unit 2 from interfering with the airflow temperature in the vacuum channel 111 during cooling or heating, thus maintaining the stability of the adsorption force. The outermost outer protective tube 14 provides mechanical protection and an installation interface for the entire assembly.

[0027] Furthermore, such as Figure 4 and Figure 7 As shown, the temperature control unit 2 includes at least one thermoelectric cooler 21 and a temperature sensor 22. The working end face of the thermoelectric cooler 21 is in contact with the vacuum nozzle 112 and the outer shell 13 of the liquid storage chamber. Cooling and heating are achieved by switching the current direction. The thermoelectric cooler 21 is a mature existing technology that does not require refrigerant or moving parts. It has a compact and reliable structure. Its working end face is in contact with both the outer shell 13 of the liquid storage chamber and the vacuum nozzle 112, ensuring that the cooling or heating effect can be transmitted to the phase change medium 114 in the liquid storage chamber 113 and the outlet area of ​​the capillary channel 222 at the same time, preventing the phase change medium 114 from solidifying prematurely or failing to melt in the middle of the capillary channel 222.

[0028] Furthermore, such as Figure 4 and Figure 5 As shown, the pressure generating device 3 consists of a piezoelectric micro diaphragm pump 31, a connecting pipe 32, and a two-position three-way micro solenoid valve 33. Both the piezoelectric micro diaphragm pump 31 and the two-position three-way micro solenoid valve 33 are installed on the outside of the outer protective pipe 14. The piezoelectric micro diaphragm pump 31, as a mature existing technology, uses the high-frequency vibration of piezoelectric ceramics to drive the diaphragm to reciprocate, and can achieve clean positive and negative pressure output in a very small volume. The two-position three-way micro solenoid valve 33, as a mature existing technology, can quickly switch between three states: positive pressure, negative pressure, and closed pressure holding. Installing the piezoelectric micro diaphragm pump 31 and the two-position three-way micro solenoid valve 33 on the outside of the outer protective pipe 14 facilitates inspection and maintenance, while shortening the gas path length and improving the pressure response speed. The piezoelectric micro diaphragm pump 31 is connected to the liquid storage chamber 113 through the connecting pipe 32, and the gas pressure generated by the piezoelectric micro diaphragm pump 31 can be transmitted to the inside of the liquid storage chamber 113 through the connecting pipe 32.

[0029] Furthermore, such as Figure 4and Figure 5 As shown, a rigid porous support plate 41 is provided between the upper part of the liquid storage cavity 113 and the connecting pipe 32. The rigid porous support plate 41 is made of stainless steel powder sintered and has micron-level interconnecting pores, which not only ensures smooth gas flow, but also has sufficient mechanical strength to withstand positive and negative pressure differences without deformation. A gas-permeable liquid-blocking membrane 42 is provided at the bottom end of the rigid porous support plate 41. The rigid porous support plate 41 serves as the mechanical support for the gas-permeable liquid-blocking membrane 42, preventing the gas-permeable liquid-blocking membrane 42 from bulging or denting due to pressure. The gas-permeable liquid-blocking membrane 42 is used to allow gas to pass through while blocking the passage of liquid phase change medium 114. The gas-permeable liquid-blocking membrane 42 is made of ePTFE material, which allows air molecules to pass freely, but liquid metal cannot penetrate due to its extremely high surface tension. Thus, while ensuring smooth gas flow, it effectively prevents the liquid phase change medium 114 from being accidentally sucked into the pressure generating device 3 and causing damage.

[0030] Furthermore, such as Figure 5 and Figure 8 As shown, a rubber ring 51 is provided at the outlet of the capillary channel 222. The rubber ring 51 is arranged around the outlet of the capillary channel 222. Under its own elasticity, the rubber ring 51 adheres tightly to the outlet of the capillary channel 222, playing a sealing role to prevent the phase change medium 114 from accidentally flowing out or external contaminants from entering the capillary channel 222. Multiple sets of guide components are provided on the outside of the rubber ring 51. The guide components include a guide plate 52, a buffer block 53, a pair of guide rods 54, a connecting plate 55, and a T-shaped plate 56. The rubber ring 51 expands and slides along the annular groove 115. The guide plate 52 is disposed around the vacuum nozzle 112. The buffer block 53 is fixed to the bottom end of the guide plate 52. When the vacuum nozzle 112 adsorbs the chip, since the lower edge of the buffer block 53 is lower than the vacuum nozzle 112 in the free state, the buffer block 53 will... First, the buffer block 53 contacts the chip. Its own elastic material is used to buffer the impact force on the chip. When the buffer block 53 is blocked by the chip, it will drive the guide plate 52 to move upward. The pair of guide rods 54 are fixed to the outside of the rubber ring 51 and slide through the guide plate 52. The guide plate 52 finally drives the rubber ring 51 to expand and slide along the annular groove 115 through the pair of guide rods 54, removing the obstruction to the capillary channel 222 and allowing the liquid to flow normally inside the capillary channel 222. The connecting plate 55 is fixed to the outside of the outer protective tube 14. The T-shaped plate 56 is fixed to the guide plate 52. The end of the T-shaped plate 56 away from the guide plate 52 is slidably connected to the inside of the connecting plate 55. The sliding connection of the T-shaped plate 56 in the connecting plate 55 provides the entire guide assembly with the freedom to float axially and supports the guide plate 52.

[0031] In addition, such as Figure 8As shown, a side plate 61 is fixedly connected to the top of the connecting plate 55. A spring 62 is fixed between the side plate 61 and the guide plate 52. The side plate 61 serves as the upper fixed fulcrum of the spring 62. The spring 62 continuously provides a downward preload to the guide plate 52. When the vacuum nozzle 112 is lifted away from the chip and the buffer block 53 gradually moves away from the chip, the elastic potential energy generated by the spring 62 will push the guide plate 52 to reset downward along the guide path of the T-shaped plate 56. Then, the guide rod 54 drives the rubber ring 51 to re-adhere and cover the outlet of the capillary channel 222.

[0032] In this embodiment, during operation, the robotic arm 73 drives the nozzle rod assembly 1 to move to the pickup station. The vacuum pump 116 generates negative pressure, causing the end face of the vacuum nozzle 112 to adsorb the chip. The buffer block 53 first contacts the chip and drives the guide plate 52 to move upward. Through the guide rod 54, the rubber ring 51 expands and slides along the annular groove 115, opening the blocked capillary channel 222 outlet. Subsequently, the thermoelectric cooler 21 in the temperature control unit 2 heats the liquid storage chamber 113, causing the phase change medium 114 to completely melt into a liquid and flow into the capillary channel 222 under gravity. The thermoelectric cooler 21 then switches to cooling mode, causing the phase change medium 114 to cool and solidify, forming multiple mushroom-shaped solid metal micro-anchors on the chip surface, cold-welding the chip to the end face of the vacuum nozzle 112 into a rigid body. When the robotic arm 73 performs angle correction, this rigid body... The connection effectively avoids microscopic slippage of the chip caused by rotational tangential inertial force. After the calibration is completed, the temperature control unit 2 switches to heating mode to melt the solid phase change medium 114. The piezoelectric micro diaphragm pump 31 in the pressure generating device 3 applies negative pressure to actively draw the liquid phase change medium 114 back to the liquid storage chamber 113 through the capillary channel 222. The arc-shaped concave surface of the annular groove 115 guides the residual droplets into the outlet of the capillary channel 222 and is completely recovered. After the back suction is completed, the pressure generating device 3 maintains the internal air pressure balance of the liquid storage chamber 113 to prevent the medium from flowing out. The vacuum pump 116 switches to micro positive pressure to help the chip smoothly detach from the end face of the vacuum nozzle 112 and be mounted on the packaging stage 72. The spring 62 pushes the guide plate 52 to reset and drives the rubber ring 51 to reseal the outlet of the capillary channel 222, and a complete working cycle is completed.

[0033] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An angle correction device for LED chip packaging, comprising a frame (71), a packaging stage (72) for placing chips, a robotic arm (73) for gripping and moving chips, and a vision sensor (74) for detecting chip position, characterized in that, Also includes: The nozzle rod assembly (1) has an axially penetrating vacuum channel (111) on its inner and outer sides, and a vacuum pump (116) that applies positive and negative air pressure to the vacuum channel (111). The bottom end of the nozzle rod assembly (1) forms a vacuum nozzle (112) for adsorbing chips. A liquid storage chamber (113) is disposed within the suction rod assembly (1) and surrounds the vacuum channel (111). A phase change medium (114) is contained within the liquid storage cavity (113); The temperature control unit (2) is thermally coupled to the liquid storage cavity (113) and switches between cooling mode and heating mode; Multiple capillary channels (222) are formed at the lower end of the nozzle rod assembly (1) and inside the vacuum nozzle (112). The inlet of the capillary channel (222) is connected to the liquid storage cavity (113), and the outlet of the capillary channel (222) opens at the end face of the vacuum nozzle (112). The pressure generating device (3) is connected to the liquid storage chamber (113) and is used to apply positive pressure to drive the phase change medium (114) to flow out through the capillary channel (222) and to apply negative pressure to draw it back. In the cooling mode, positive pressure is applied, and the phase change medium (114) seeps out and solidifies between the back of the chip and the vacuum nozzle (112) to form a temporary lock. In the heating mode, negative pressure is applied, and the solidified phase change medium (114) melts and is actively drawn back, thus completing the chip release.

2. The angle correction device for LED chip packaging according to claim 1, characterized in that, The suction rod assembly (1) includes a vacuum inner tube (11), a heat insulation sleeve (12), a liquid storage chamber outer shell (13), and an outer protective tube (14) arranged coaxially from the inside to the outside. The vacuum channel (111) is formed inside the vacuum inner tube (11), and the liquid storage chamber (113) is formed between the outer wall of the heat insulation sleeve (12) and the inner wall of the liquid storage chamber outer shell (13). The heat insulation sleeve (12) is used to block the heat or cold generated by the temperature control unit (2) from being conducted to the vacuum channel (111).

3. The angle correction device for LED chip packaging according to claim 1, characterized in that, The phase change medium (114) is a eutectic liquid metal alloy with a melting point between 40°C and 60°C.

4. The angle correction device for LED chip packaging according to claim 2, characterized in that, The temperature control unit (2) includes at least one thermoelectric cooler (21) and a temperature sensor (22). The working end face of the thermoelectric cooler (21) is in contact with the vacuum nozzle (112) and the outer shell (13) of the liquid storage chamber. Cooling and heating are achieved by switching the direction of current.

5. An angle correction device for LED chip packaging according to claim 2, characterized in that, The pressure generating device (3) consists of a piezoelectric micro diaphragm pump (31), a connecting pipe (32), and a two-position three-way micro solenoid valve (33). The piezoelectric micro diaphragm pump (31) and the two-position three-way micro solenoid valve (33) are both installed on the outside of the outer protective pipe (14). The piezoelectric micro diaphragm pump (31) is connected to the liquid storage chamber (113) through the connecting pipe (32).

6. The angle correction device for LED chip packaging according to claim 1, characterized in that, The vacuum nozzle (112) has an annular groove (115) around its outer periphery. All the outlets of the capillary channels (222) open into the annular groove (115) to contain and constrain the seeping liquid phase change medium (114).

7. An angle correction device for LED chip packaging according to claim 5, characterized in that, A rigid porous support plate (41) is provided between the upper part of the liquid storage cavity (113) and the connecting pipe (32). A gas-permeable liquid-blocking membrane (42) is provided at the bottom end of the rigid porous support plate (41). The gas-permeable liquid-blocking membrane (42) is used to allow gas to pass through while preventing the liquid phase change medium (114) from passing through.

8. An angle correction device for LED chip packaging according to claim 2, characterized in that, The outlet of the capillary channel (222) is provided with a rubber ring (51). Multiple sets of guide components are provided on the outside of the rubber ring (51). The guide components include a guide plate (52), a buffer block (53), a pair of guide rods (54), a connecting plate (55), and a T-shaped plate (56). The rubber ring (51) expands and slides along the annular groove (115). The guide plate (52) is located around the vacuum nozzle (112). The buffer block (53) is fixed to the bottom end of the guide plate (52). The pair of guide rods (54) are fixed to the outside of the rubber ring (51) and slide through the guide plate (52). The connecting plate (55) is fixed to the outside of the outer protective tube (14). The T-shaped plate (56) is fixed to the guide plate (52). The end of the T-shaped plate (56) away from the guide plate (52) is slidably connected to the inside of the connecting plate (55).

9. An angle correction device for LED chip packaging according to claim 8, characterized in that, A side plate (61) is fixedly connected to the top of the connecting plate (55), and a spring (62) is fixedly connected between the side plate (61) and the guide plate (52).

10. An angle correction device for LED chip packaging according to claim 8, characterized in that, The lower edge of the buffer block (53) is lower than the vacuum nozzle (112) in a free state.

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