Mechanical vibration anti-blocking type ball distributing structure and ball mounting and cleaning method thereof

Abstract

The invention discloses a mechanical vibration anti-blocking type ball distributing structure and a ball mounting and cleaning method thereof, and belongs to the technical field of microelectronic manufacturing and packaging. The mechanical vibration anti-blocking type ball distributing structure comprises an upper end cover, a lower end cover, a ball conveying assembly, a vibration assembly and a ball spraying assembly; the upper end cover and the lower end cover are fixed through an inner shaft, and the ball conveying assembly, the vibration assembly and the ball spraying assembly are supported on the upper end cover and the lower end cover. The ball conveying assembly is used for conveying the solder balls into the ball spraying assembly, and the solder balls are sprayed out by the ball spraying assembly; the ball conveying assembly comprises a ball storage bin; the vibration assembly slightly vibrates the ball storage bin, so that the solder balls in the ball storage bin are prevented from being blocked at the outlet of the ball storage bin. According to the mechanical vibration anti-blocking type ball distributing structure and the ball mounting and cleaning method thereof, the structure can redistribute a solder ball stacking mode, solder ball accumulation is relieved, the ball blocking problem at the ball leaking hole, the ball conveying track and the nozzle is effectively solved, and therefore the ball mounting efficiency is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of microelectronics manufacturing and packaging, and specifically relates to a mechanical vibration anti-blocking ball separation structure and a ball planting and cleaning method thereof. Background Art

[0002] Ball grid array (BGA) and flip chip technology have been widely used in the field of electronic packaging, which can meet the needs of a large number of I / Os and shorter connection pitches. As an essential front-end process for ball grid array (BGA) and flip chip, ball planting is widely used in the production of various packaging products. It is a key technology for achieving leadless connection. Compared with the traditional template printing method for ball planting, laser ball planting is more flexible and can quickly plant balls on non-matrix, three-dimensional solder joints. Laser ball planting also has many advantages such as low cost, accurate fixed-point positioning, high rework efficiency, no flux, and little thermal impact on non-welding areas. Laser ball planting technology is used for precise ball planting on substrates and pads waiting for welding. The head structure of its ball planting equipment includes a laser system, a ball feeding system, and a control system. Its working principle is: first, the ball planting head transports the solder ball to the air above the surface to be welded through the ball feeding system. Then, the laser generator emits a laser beam at a specific time and focuses it on the surface of the solder ball, causing the solder ball to melt rapidly. Finally, the solder ball is shot toward the surface to be welded in a molten state, and after contacting the surface to be welded, the solder ball quickly cools and solidifies to form a spherical shape.

[0003] Since the ball spraying system of laser ball planting is complex and contains many subsystems, especially the mechanical conveying method is relatively complex, the laser ball planting head will frequently have problems of ball blocking or no ball in the internal conveying path and nozzle, that is, the ball blocking rate and empty ball rate are high. This seriously affects the efficiency of the laser ball planting process and also causes problems such as ball deviation and ball bouncing. Invention patent CN 103817438 A discloses a solder ball welding device and method, which includes a transmission mechanism for transmitting solder balls, the transmission mechanism is connected to the solder ball holding unit, and a pushing mechanism and a limiting mechanism are provided at the connection between the first channel and the second channel inside. Its working principle is to push the cylinder to push the thrust rod and then push the solder ball in the channel from the first channel to the second channel, and then reset the pushing mechanism. The principle of the pushing structure is similar to that of loading a bullet, and the design is novel, but the structure is complex and it is easy to cause jamming or ball blocking. In particular, cleaning the solder ball requires disassembly and cleaning the channel. At the same time, due to the extrusion of the thrust rod and the limiting rod, the solder ball has the risk of deformation, which increases the ball blocking rate at each channel and the holding unit. Invention patent CN 105458446A invented a solder ball welding device, which uses a rotary drive to drive the separation shaft to rotate, and the solder balls fall into the separation holes on the separation shaft to be separated one by one, and are sent to the solder ball holding mechanism through the solder ball guide tube. Similarly, this invention will cause extrusion to the solder balls, resulting in the risk of deformation of the solder balls, which in turn causes the problem of ball blocking. Invention patent CN201120305714.5 discloses a laser ball implantation system that can continuously feed solder balls into the working chamber. However, the elastic baffle and the spring in this system have complex mechanical structures, and each ejection is driven by the up and down movement of the working chamber and the stacking pressure of the ball itself, the homing cycle is long, and the conveying efficiency is low. The initial velocity direction of the solder ball ejected into the working chamber from the side is horizontal, which does not match the target welding direction (vertically downward), and the welding efficiency is low. The elastic baffle and the disturbance structure are prone to cause ball blocking and jamming problems. The solder balls in the ball delivery pipeline are squeezed by the disturbance structure to produce downward pressure, which is also easy to cause the solder balls to deform. Patent CN202020248986.5 discloses a laser ball planting nozzle, which mainly includes a nozzle body, a spray plate mounting seat and a diamond spray plate. This structure facilitates the fixation of the diamond spray plate and ensures the stable operation of the diamond spray plate. However, the apertures of the three center holes in the nozzle of this structure are different, which can easily cause ball blockage at the nozzle. Utility model patent CN204975617 U discloses a laser tin spraying device, the soldering nozzle has a laser guide hole and a connected solder bead clamping hole, and the solder bead clamping hole is the solder bead spraying outlet of the soldering nozzle. Invention patent CN 206122844 U discloses a laser soldering device, the drive motor and the disk can be installed and positioned according to their respective installation spaces, and the output shafts and the rotating shafts of the two can be connected by an inclined connecting shaft for transmission. Invention patent CN 116021104 A discloses a BGA component maintenance device, method and system. It includes an SRT rework station, on which a laser tin spraying module and a ball feeding mechanism are arranged.The ball delivery mechanism includes a liftable nozzle, a ball distribution plate and other structures, but the details of the ball distribution structure are not specifically displayed.

[0004] The above-disclosed invention does not take into account the risk of ball blockage caused by the stacking of solder balls in the tin ball container in the structural design. In fact, the larger the diameter of the solder ball, the more stable the ball feeding, and the smaller the diameter of the solder ball, the easier it is to get blocked in the ball feeding path and the nozzle. The existing laser ball planting machine ball separation structure mostly adopts the method of conveying solder balls with a ball separation disk, and this structure has good ball feeding stability. For solder balls with a large diameter of more than 300 microns, this structure can spray balls continuously with a low idling rate. However, for solder balls with a diameter of less than 300 microns, this structure often has ball blockage or a high idling rate. The most common ball blocking point is located at the connection between the ball storage bin and the ball separation disk. The disordered stacking of solder balls in the hourglass-shaped ball storage bin is the root cause of the ball blockage. In the prior art, solder balls are easily accumulated in the ball leakage hole channel under the action of gravity. If the solder balls are directly smaller than 300 microns, the solder balls that are stacked and rubbed against each other will adhere to each other under the action of electrostatics, and are also easily affected by moisture and adsorbed into agglomerates under the action of capillaries. The smaller the solder ball is, the smaller the ratio of the solder ball's gravity to the adsorption force is, and the easier it is to get stuck. The second most common point of ball blocking is at the nozzle, where solder ball deformation or unstable parameters such as laser power cause the solder ball to get stuck at the nozzle.

[0005] Therefore, in order to solve the above problems, it is necessary to improve the ball storage bin structure within the ball separation structure of the laser ball implanter, with the focus on regularly changing the stacking method of the solder balls in the ball storage bin and performing secondary distribution of the solder ball positions. Summary of the invention

[0006] The purpose of the present invention is to provide a mechanical vibration anti-blocking ball distribution structure and its ball planting and cleaning method to address the above shortcomings. The structure can redistribute the solder ball stacking method, reduce solder ball backlog, and effectively improve the ball blocking problem at the ball leakage hole, ball delivery track, and nozzle, thereby greatly improving the ball planting efficiency. To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A mechanical vibration anti-blocking ball separation structure comprises an upper end cover, a lower end cover, a ball conveying assembly, a vibration assembly and a ball spraying assembly; the upper end cover and the lower end cover are fixed by an inner shaft, and the ball conveying assembly, the vibration assembly and the ball spraying assembly are supported on the upper end cover and the lower end cover; the ball conveying assembly is used to convey the solder balls to the ball spraying assembly, and the solder balls are sprayed out by the ball spraying assembly; the ball conveying assembly comprises a ball storage bin; the vibration assembly slightly vibrates the ball storage bin to prevent the solder balls in the ball storage bin from being blocked at the outlet of the ball storage bin.

[0008] Furthermore, the ball storage bin includes at least two bin bodies, and two adjacent bin bodies are elastically connected to each other so as to achieve relative dislocation movement.

[0009] Furthermore, the vibration assembly includes an outer shaft and an outer shaft disturbance tooth connected to the outer shaft; the outer shaft is sleeved on the inner shaft and can rotate relative to the inner shaft; the outer side wall of the bin body is provided with a ball storage bin disturbance tooth that cooperates with the outer shaft disturbance tooth, and the rotation of the outer shaft disturbance tooth synchronizes the rotation of the outer shaft to drive the bin body to vibrate.

[0010] Furthermore, the ball conveying assembly includes a ball dividing plate linked to the outer shaft; the ball dividing plate is provided with a plurality of ball leakage holes, and the plurality of ball leakage holes can be aligned and connected with the lower end opening of the ball storage bin as the ball dividing plate rotates; the lower end cover is provided with a ball conveying track, and the welding ball falls from the lower end of the ball storage bin through the ball leakage holes into the ball conveying track, and as the ball dividing plate rotates, the welding ball is driven to move along the ball conveying track into the ball spraying assembly.

[0011] Furthermore, the ball spray assembly includes a laser emitter arranged on the upper end cover, a laser channel and a nozzle arranged on the lower end cover; the rotation of the ball dividing piece can make the laser channel, the ball leakage hole and the nozzle be on the same axis and connected; the outer wall of the nozzle is provided with a preheating device to keep the nozzle warm.

[0012] Furthermore, the upper end cover is provided with a nitrogen channel and a nitrogen heating wire; the nitrogen channel is connected to the laser channel; and the nitrogen heating wire is used for heating the nitrogen.

[0013] Furthermore, a cleaning channel is provided on the lower end cover; the cleaning channel is connected to the ball conveying track; and the cleaning channel can be externally connected to a high-pressure gas source.

[0014] Furthermore, the upper end cover and the lower end cover are both provided with pressure measuring channels, the pressure measuring channel of the upper end cover is connected to the laser channel, and the pressure measuring channel of the lower end cover is connected to the nozzle; the pressure measuring channel is connected to a pressure sensor electrically connected to the laser emitter.

[0015] A ball planting method of mechanical vibration anti-blocking ball distribution, using the above mechanical vibration anti-blocking ball distribution structure;

[0016] (1): Assemble the ball separation mechanism and the external laser ball implanter, and rotate the external shaft to ensure smooth rotation;

[0017] (2): Pour 100 micron tin-silver-copper solder balls into the ball storage bin, and the space occupied by the solder balls shall not exceed 2 / 3 of the ball storage bin;

[0018] (3): Set the temperature of the preheating device on the nozzle to 120°C, and the nitrogen heating wire heats the nitrogen channel temperature to 100°C;

[0019] (4): The laser ball implanter sets the nozzle at a distance of 0.7 to 1 mm from the surface to be welded, and starts implanting balls according to the laser ball implanter program.

[0020] A cleaning method for mechanical vibration anti-blocking ball separation adopts the above-mentioned mechanical vibration anti-blocking ball separation structure; if it is found that the welding ball does not rotate smoothly in the ball conveying track, a 0.5Mpa nitrogen source is connected to the entrance of the cleaning channel for 10 seconds to check whether the ball rotates smoothly;

[0021] If the ball is found to be blocked at the nozzle, set the temperature of the preheating device on the nozzle to 180°C, and connect a 0.5Mpa nitrogen source to the entrance of the nitrogen channel for 10 seconds before checking whether the ball is spraying smoothly.

[0022] The beneficial effects of the present invention are:

[0023] 1. Reduce the idling rate and the ball blocking rate. The linked disturbance teeth drive the ball storage bin to vibrate, so that the solder balls in the primary and secondary bins are rearranged. The number and size of disturbance teeth can be designed according to the size and material of the solder balls. The more disturbance teeth there are, the higher the vibration frequency; the larger the disturbance teeth are, the higher the vibration intensity is. If the solder balls are large in size and density, a low-frequency, high-intensity disturbance design is used. If the solder balls are small in size and low in density, a high-frequency, low-intensity disturbance design is used.

[0024] 2. Convenient to clean up excess materials. When assembling the existing ball-turning mechanism, stains, welding ball slag and other excess materials on the ball-dividing plate will cause the ball-dividing plate to fit poorly with the lower end cover. Long-term ball-turning will increase the resistance of the ball-dividing plate and scratch and wear the ball-dividing plate. The structure of the present invention includes a cleaning channel in the lower end cover. Excess materials stuck on the ball-dividing plate will be collected in the cleaning channel during the rotation of the ball-dividing plate. The collected excess materials can be blown out by regularly connecting a high-pressure gas source to the cleaning channel. A ball delivery channel is designed on the end cover to greatly reduce the chances of slippage and dislocation of the welding balls;

[0025] 3. Cleaning the solder balls without disassembling the whole structure. The existing ball rotating mechanism needs to disassemble the whole structure to replace the solder balls. If it is not cleaned properly, it is easy to cause solder balls to remain in the ball bin, and frequent disassembly of the end caps can easily scratch and contaminate the ball separators, causing the fastening structures such as threads to fail. In the present invention, the cleaning channel is connected to the ball leakage hole, and an external high-pressure air source is connected to the cleaning channel, so that the solder balls in the ball storage bin can be blown out under the action of the high-pressure airflow, eliminating the process of disassembling the end caps.

[0026] 4. Reduce the nozzle blockage rate. The nozzle of the existing structure has no additional temperature control structure. After being heated by the laser, the temperature rises rapidly and then cools rapidly. The solder ball is not fully melted, resulting in a low strength connection between the ejected solder ball and the substrate. The present invention provides a preheating device for the nozzle, which can preheat the nozzle and maintain it at a specified temperature. First, the preheating temperature is slightly lower than the melting temperature of the solder ball. The laser emitter only needs to emit a low-power laser to melt the solder ball. The low-power laser has better stability and is not easy to burn the pad and the nozzle. While the solder ball is being ejected, a constant temperature nitrogen flow or a low-power laser can continuously keep the solder ball warm. This allows the solder ball to still have a high temperature when it contacts the pad, thereby improving the welding strength. Secondly, the micro-hot nitrogen flow and the nozzle preheating device can keep the nozzle warm, which can reduce the phenomenon of molten solder balls hanging or sticking to the inner wall of the nozzle, thereby avoiding ball blockage at the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional schematic diagram of a mechanical anti-blocking ball-dividing structure of the present invention;

[0028] Figure 2 It is a top view of the lower end cover of a mechanical anti-blocking ball-dividing structure of the present invention;

[0029] Figure 3 It is a schematic diagram of the ball-dividing sheet of the present invention;

[0030] Figure 4 is a schematic diagram of a sealing sheet of the present invention;

[0031] In the attached drawings: 1. lower end cover; 2. ball dividing plate; 3. sealing plate; 4. upper end cover; 5. primary bin body; 6. primary bin body firmware; 7. primary bin body disturbance tooth; 8. secondary bin body disturbance tooth; 9. secondary bin body; 10. ball storage bin entrance; 11. secondary bin body firmware; 12. secondary external shaft disturbance tooth; 13. primary external shaft disturbance tooth; 14. inner shaft; 15. outer shaft; 16. laser transmitter; 17. laser channel; 18. pressure measuring channel; 19. transmission pin; 20. nozzle; 21. nitrogen heating wire; 22. ball transport track; 23. pin hole; 24. ball leakage hole; 25. cleaning channel; 26. nozzle heating ring; 27. nitrogen channel. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.

[0033] Embodiment 1:

[0034] See attached Figures 1 to 4A mechanical vibration anti-blocking ball separation structure is mainly composed of a lower end cover 1, a ball separation plate 2, a sealing plate 3, an upper end cover 4, an inner shaft 14, an outer shaft 15, and a ball storage bin. The outer shaft 15 can be linked with the ball separation plate 2 to rotate, and after the solder balls in the ball storage bin are sent to the laser channel 17 through the ball delivery track 22, the solder balls leak into the nozzle 20, and the laser emitter 16 emits laser to melt the solder balls in the nozzle 20 and eject them under nitrogen pressure. The outer shaft 15 disturbance teeth on the outer shaft 15 cooperate with the ball storage bin disturbance teeth to vibrate the ball storage bin, redistribute the stacking method of the solder balls, and can effectively improve the problem of ball blocking in the ball storage bin.

[0035] A mechanical anti-blocking ball dividing structure of the present invention mainly comprises an upper layer, a middle layer and a lower layer structure. The main body of the upper layer structure is an upper end cover 4, and the upper end cover 4 comprises a ball storage bin entrance 10. The ball storage bin is preferably composed of two bin bodies, namely a primary bin body 5 and a secondary bin body 9. The ball storage bin is connected to the upper end cover 4 through software. To ensure that the ball storage bin can make relative movement relative to the upper end cover 4, the ball storage bin is connected to the ball storage bin through software. The primary bin body 5 is connected to the primary bin body software 6, and the secondary bin body 9 is connected to the secondary bin body software 11. Correspondingly, a primary bin body disturbance tooth 7 is set on the primary bin body 5, and a secondary bin body disturbance tooth 8 is set on the secondary bin body 9. The middle layer structure consists of a ball dividing sheet 2 and The sealing plate 3 is composed of the lower structure mainly including the lower end cover 1 and the discharge trough and the nozzle 20 arranged on the lower end cover 1; the three-layer structure is connected by the inner shaft 14 and the outer shaft 15 of the same axis, and the inner shaft 14 and the outer shaft 15 realize the rotation movement of the outer shaft 15 relative to the inner shaft 14 through the bearing structure, and the inner shaft 14 fixes the three-layer structure through the nut at the end, and the outer shaft 15 is provided with an outer shaft 15 disturbance tooth, which includes a first-level outer shaft disturbance tooth 13 corresponding to the first-level bin body disturbance tooth 7 and a second-level outer shaft disturbance tooth 12 corresponding to the second-level bin body disturbance tooth 8. The rotation of the outer shaft 15 provides power for the rotation of the ball-dividing plate 2, the first-level outer shaft disturbance tooth 13, and the second-level outer shaft disturbance tooth 12. Figure 1 The principle is that the inner shaft 14 connects and fixes the upper layer, the middle layer and the lower layer, and the outer shaft 15 synchronously provides power for the rotation of the ball distribution plate 2 and the mechanical vibration of the primary and secondary bins 9. The advantage is that the slight mechanical vibration of the ball storage bin can redistribute the accumulated solder balls and alleviate the solder ball blocking phenomenon.

[0036] The ball storage bin is preferably divided into a multi-level vertical arrangement structure of at least two levels of a primary bin body 5 and a secondary bin body 9, wherein the primary bin body 5 has the smallest volume, and the secondary bin body 9 has a slightly larger volume. The connection points of the bin bodies of the ball storage bins at each level are connected and sealed by elastic films. The principle is that the solder balls of the primary bin body 5 are on the lower side of the stacking layer, and the pressure on the solder balls is relatively large, making them more easily adsorbed to each other, and the narrowing of the passage of the ball storage bin makes it easier to be blocked. Therefore, it is necessary to vibrate the solder balls of the primary bin body 5 at a high frequency, but the amplitude should not be too large, otherwise the position offset of the primary bin body 5 is not conducive to the solder balls leaking into the ball leakage hole 24. Therefore, the primary bin body 5 should adopt high-frequency and small-amplitude vibration. The solder balls of the secondary bin body 9 are on the upper side of the stacking layer, and the pressure on the solder balls is relatively small, but the secondary bin body 9 has a slightly larger volume and a larger capacity for solder balls, and large-amplitude vibration is applied to redistribute their stacking mode. The advantage of this structure is that, according to the vibration requirements and characteristics of each level of ball storage bins, bin disturbance teeth of different densities and sizes can be designed on the outer sides of each level of ball storage bins.

[0037] The upper side of the primary bin body 5 is connected to the main body of the upper end cover 4 through springs, rubber and other soft firmware, and the lower side of the secondary bin body 9 is connected to the main body of the upper end cover 4 through springs, rubber and other soft firmware. Its principle and advantage is that the soft firmware fixes the ball storage bin on the end cover and plays a buffering and homing role, reducing the impact of vibration on other structures such as the end cover while meeting the vibration amplitude.

[0038] At least one primary bin body disturbance tooth 7 is arranged on the outer wall of the primary bin body 5, and at least one secondary bin body disturbance tooth 8 is arranged on the outer wall of the secondary bin body 9. The disturbance tooth is an inclined meshing structure such as a helical gear or a cam. The outer shaft 15 has a primary external shaft disturbance tooth 13, which meshes with the primary bin body disturbance tooth 7, and the number of teeth of the primary external shaft disturbance tooth 13 is greater than the number of teeth of the primary bin body disturbance tooth 7; the external shaft 15 also has a secondary external shaft disturbance tooth 12, which meshes with the secondary bin body disturbance tooth 8, and the number of teeth of the secondary external shaft disturbance tooth 12 is greater than the number of teeth of the secondary bin body disturbance tooth 8. The principle is that the disturbance tooth can periodically provide radial and axial forces to the ball storage bin, thereby driving the periodic vibration of the ball storage bin. Different numbers of disturbance teeth can be designed for each level of ball storage bin according to actual vibration requirements, so as to achieve different vibration frequencies corresponding to each level of ball storage bin. The advantage is that the mechanical structure is simple and the vibration of each level of the ball storage bin body can be achieved by rotating only one outer shaft 15.

[0039] The sealing sheet 3 is coaxially arranged in the middle layer with the ball dividing sheet 2, and the thickness of the sealing ring is 1.1 to 1.2 times of the ball dividing sheet 2. The transmission pin 19 is arranged at the bottom of the outer shaft 15 and inserted into the pin hole 23 arranged on the ball dividing sheet 2. The rotation of the outer shaft 15 can drive the ball dividing sheet 2 to rotate. The principle and advantage are that the outer shaft 15 drives the ball dividing sheet 2 to rotate through the transmission pin 19, and the welding balls in the ball leakage holes 24 on the ball dividing sheet 2 are also driven to rotate along the ball conveying track 22 on the lower end cover 1. The thickness of the sealing ring is 1.1 to 1.2 times of the ball dividing sheet 2, so that the sealing ring can play a sealing and supporting role between the upper end cover 4 and the lower end cover 1, and the reserved thickness space can reduce the friction force on the rotation of the ball dividing sheet 2.

[0040] There are a number of ball leakage holes 24 with the same diameter distributed in a ring on the ball dividing plate 2. The diameter of the ball leakage holes 24 on the ball dividing plate 2 is 1.1 to 1.5 times the diameter of the solder ball. There is an annular ball conveying track 22 on the lower end cover 1. The groove depth of the ball conveying track 22 is less than 0.5 times the diameter of the solder ball. The ball leakage holes 24 on the ball dividing plate 2 can push the solder ball to roll on the ball conveying track 22 to the laser channel 17. The principle is that the size of the ball leakage holes 24 is slightly larger than the size of the solder ball, so that the solder ball is more smoothly aligned and the risk of ball blocking is reduced. The ball conveying track 22 limits the rotation of the solder ball to a ring path, reducing the problem of slippage or extrusion of the solder ball.

[0041] The lower end cover 1 has at least one cleaning channel 25 arranged radially on one side of the ball storage bin. The external interface of the cleaning channel 25 on the lower side of the lower end cover 1 can be connected to a high-pressure gas source for cleaning excess matter. The principle and advantage are that the excess matter adhering to the ball dividing plate 2 will be collected in the cleaning channel 25 during the rotation of the ball dividing plate 2. The collected excess matter can be blown out by regularly connecting the high-pressure gas source to the cleaning channel 25, thus avoiding the problem of frequently disassembling the ball dividing structure for cleaning.

[0042] The laser channel 17 runs through the upper, middle and lower structures, the nozzle 20 is coaxial with the laser channel 17, the inlet and outlet of the pressure measuring channel 18 are on the side of the upper end cover 4 and the lower end cover 1, and the pressure measuring channel 18 merges into the laser channel 17 and is connected with the ball leakage hole 24. The principle is that the pressure measuring channel 18 is separated by the ball dividing plate 2, and the ball leakage hole 24 on the ball dividing plate 2 is the valve for its connection. When the ball leakage hole 24 is transferred to the laser channel 17 and the solder ball falls off, the spaces on both sides of the ball leakage hole 24 are connected. The pressure sensor outside the pressure measuring channel 18 can trigger the laser emitter 16 to emit laser and the nitrogen channel 27 to circulate heated nitrogen.

[0043] The nitrogen channel 27 merges into the laser channel 17. A nitrogen heating wire 21 is provided at the entrance of the nitrogen channel 27 to heat the nitrogen. The heated slightly heated nitrogen flow provides impact force for the nozzle 20 to eject the solder ball, and keeps the nozzle 20 and the solder ball warm, isolating the solder ball from oxygen. The principle and advantage are that the slightly heated nitrogen flow and the nozzle 20 preheating device keep the nozzle 20 warm, which can reduce the molten solder ball from tinning or sticking to the inner wall of the nozzle 20, and avoid the problem of ball blocking at the nozzle 20.

[0044] The nozzle 20 is wrapped with a preheating device. The preheating device can be a nozzle heating ring 26 formed by a resistance heating wire or other temperature-controllable heating structure. The nozzle 20 can be preheated and kept at a constant temperature. The preheating temperature is at least 10°C lower than the melting point of the solder ball. The principle is that the preheating temperature is slightly lower than the melting point of the solder ball, and the laser channel 17 only needs to emit a low-power laser to melt the solder ball. Low-power lasers have better stability, and while the solder ball is being ejected, a constant temperature nitrogen flow or low-power laser can continuously keep the solder ball warm. This allows the solder ball to still have a higher temperature when it contacts the pad, thereby improving the welding strength.

[0045] Embodiment 2:

[0046] See attached Figures 1 to 4 A mechanical vibration anti-blocking ball planting method, after the ball separator 2, the sealing ring, and the nozzle 20 are wiped with water or alcohol, they are dried with hot air; the ball separator 2, the sealing ring, the nozzle 20 and the remaining structures are pressed Figure 1 Assemble and assemble the entire ball distribution structure on the laser ball planting machine, rotate the outer shaft 15 to ensure smooth rotation; pour 100 micron tin-silver-copper solder balls into the ball storage bin, the space occupied by the solder balls does not exceed 2 / 3 of the overall ball storage bin, and then install the ball storage bin cover and tighten it; operate the laser ball planting machine to control the rotation of the outer shaft 15 until the first solder ball is transferred to the laser channel 17; set the temperature of the nozzle 20 preheating device to 120°C, and set the temperature of the nitrogen channel 27 to 100°C; operate the laser ball planting machine so that the distance between the nozzle 20 and the surface to be welded is 0.7-1mm, and start ball planting according to the laser ball planting machine program.

[0047] Embodiment three:

[0048] See attached Figures 1 to 4 A mechanical vibration anti-blocking ball separation cleaning method. If the equipment has not been used for a long time or the solder ball is not turning smoothly in the ball delivery track 22 during the ball planting process, connect the entrance of the cleaning channel 25 to a 0.5Mpa nitrogen source for 10 seconds, check again whether the ball is turning smoothly, and repeat the above steps until the ball is turning smoothly; if the nozzle 20 is found to be blocked, set the temperature of the nozzle 20 preheating device to 180°C, connect the entrance of the nitrogen channel 27 to a 0.5Mpa nitrogen source for 10 seconds, check again whether the ball is spraying smoothly, and repeat the above steps until the ball is spraying smoothly.

[0049] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A mechanical vibration anti-blocking ball separation structure, characterized in that: The invention comprises an upper end cover (4), a lower end cover (1), a ball conveying assembly, a vibration assembly and a ball spraying assembly; the upper end cover (4) and the lower end cover (1) are fixed by an inner shaft (14), and the ball conveying assembly, the vibration assembly and the ball spraying assembly are supported on the upper end cover (4) and the lower end cover (1); the ball conveying assembly is used to convey the solder balls to the ball spraying assembly, and the solder balls are sprayed out by the ball spraying assembly; the ball conveying assembly comprises a ball storage bin; the vibration assembly slightly vibrates the ball storage bin to prevent the solder balls in the ball storage bin from being blocked at the outlet of the ball storage bin.

2. The mechanical vibration anti-blocking ball separation structure according to claim 1, characterized in that: The ball storage bin comprises at least two bin bodies, and two adjacent bin bodies are elastically connected to each other so as to achieve relative dislocation movement.

3. The mechanical vibration anti-blocking ball separation structure according to claim 2, characterized in that: The vibration assembly comprises an outer shaft and an outer shaft disturbance tooth connected to the outer shaft; the outer shaft is sleeved on the inner shaft (14) and can rotate relative to the inner shaft (14); the outer wall of the bin body is provided with a ball storage bin disturbance tooth that cooperates with the outer shaft disturbance tooth, and the rotation of the outer shaft disturbance tooth is synchronized with the rotation of the outer shaft, thereby driving the bin body to vibrate.

4. The mechanical vibration anti-blocking ball separation structure according to claim 3 is characterized by: The ball conveying assembly comprises a ball dividing plate (2) linked to the outer shaft; the ball dividing plate (2) is provided with a plurality of ball leakage holes (24), and the plurality of ball leakage holes (24) can be aligned and connected with the lower opening of the ball storage bin as the ball dividing plate (2) rotates; the lower end cover (1) is provided with a ball conveying track (22), and the welding balls fall from the lower end of the ball storage bin through the ball leakage holes (24) into the ball conveying track (22), and as the ball dividing plate (2) rotates, the welding balls are driven to move along the ball conveying track (22) into the ball spraying assembly.

5. The mechanical vibration anti-blocking ball separation structure according to claim 4, characterized in that: The spray ball assembly comprises a laser emitter (16) arranged on an upper end cover (4), a laser channel (17) and a nozzle arranged on a lower end cover (1); the rotation of the ball dividing plate (2) enables the laser channel (17), the ball leakage hole (24) and the nozzle to be located on the same axis and to be connected; and a preheating device is provided on the outer wall of the nozzle to keep the nozzle warm.

6. The mechanical vibration anti-blocking ball separation structure according to claim 5, characterized in that: The upper end cover (4) is provided with a nitrogen channel (27) and a nitrogen heating wire (21); the nitrogen channel (27) is connected to the laser channel (17); and the nitrogen heating wire (21) is used for heating nitrogen.

7. The mechanical vibration anti-blocking ball separation structure according to claim 6, characterized in that: The lower end cover (1) is provided with a cleaning channel (25); the cleaning channel (25) is connected to the ball conveying track (22); and the cleaning channel (25) can be connected to an external high-pressure gas source.

8. The mechanical vibration anti-blocking ball separation structure according to claim 7, characterized in that: The upper end cover (4) and the lower end cover (1) are both provided with a pressure measuring channel (18); the pressure measuring channel (18) of the upper end cover (4) is connected to the laser channel (17), and the pressure measuring channel (18) on the lower end cover (1) is connected to the nozzle; the pressure measuring channel (18) is connected to a pressure sensor electrically connected to the laser emitter (16).

9. A ball planting method for mechanical vibration anti-blocking ball distribution, characterized in that: Adopting the mechanical vibration anti-blocking ball separation structure as claimed in claim 8; (1): Assemble the ball separation mechanism and the external laser ball implanter, and rotate the external shaft to ensure smooth rotation; (2): Pour 100 micron tin-silver-copper solder balls into the ball storage bin, and the space occupied by the solder balls shall not exceed 2 / 3 of the ball storage bin; (3): The temperature of the preheating device on the nozzle is set to 120°C, and the nitrogen heating wire (21) heats the temperature of the nitrogen channel (27) to 100°C; (4): The laser ball implanter sets the nozzle at a distance of 0.7 to 1 mm from the surface to be welded, and starts implanting balls according to the laser ball implanter program.

10. A mechanical vibration anti-blocking ball separation cleaning method, characterized in that: The mechanical vibration anti-blocking ball separation structure as claimed in claim 8 is adopted; if it is found that the welding ball does not rotate smoothly in the ball conveying track (22), a 0.5Mpa nitrogen source is connected to the entrance of the cleaning channel (25) for 10 seconds and then the ball is checked to see whether it rotates smoothly; If the ball is blocked at the nozzle, set the temperature of the preheating device on the nozzle to 180°C, and connect a 0.5Mpa nitrogen source to the inlet of the nitrogen channel (27) for 10 seconds before checking whether the ball is spraying smoothly.

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