Laser ball mounting structure with anti-blocking function and ball mounting method

Abstract

The invention relates to the technical field of microelectronic manufacturing and packaging, and particularly discloses a laser ball mounting structure with an anti-blocking function and a ball mounting method. Comprising an upper-layer structure with a ball storage bin, a ball distributing structure located below the upper-layer structure, and a bottom-layer structure located below a middle-layer structure and provided with a ball spraying mechanism. The ball distributing structure is in running fit with the upper-layer structure and the bottom-layer structure and is used for spraying out the solder balls in the ball storage bin from an outlet of the ball spraying mechanism; a plurality of groups of baffle plates which are staggered in the vertical direction and form a baffle channel are arranged in the ball storage bin; the top of the ball storage bin is externally connected with a pressurized air source; the bottom of the ball storage bin is provided with a pulse channel which is communicated with the ball storage bin and provides pulse airflow into the ball storage bin. According to the invention, the extrusion of the solder ball stack on the ball leakage hole can be dispersed, and the stacked solder balls can be redistributed in combination with air flow, so that the backlog effect is relieved, the problem of ball blockage is effectively improved, and the ball mounting efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of microelectronics manufacturing and packaging, and more particularly to a laser ball implantation structure and a ball implantation method with an anti-blocking function. Background Art

[0002] Ball grid array (BGA) and flip chip (Flip Chip) technologies have been widely used in the field of electronic packaging, and can meet the needs of a larger number of I / Os and shorter connection pitches. As an essential front-end process for ball grid array (BGA) and flip chip (Flip Chip), ball planting is also 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, reduced use of flux, and little thermal impact on non-welding areas.

[0003] Laser ball implantation technology is used to accurately implant balls on substrates and pads waiting for welding. The head structure of the ball implantation equipment includes a laser system, a ball feeding system, and a control system. Its working principle is: first, the ball implantation 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 on the surface of the solder ball, causing the solder ball to melt rapidly. Finally, the solder ball is ejected 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.

[0004] Since the laser ball implanting spraying system is complex and contains many subsystems, especially the mechanical conveying method, the laser ball implanting head will frequently have problems of ball blockage or ball absence in the internal conveying path and nozzle, that is, the ball blockage rate and empty ball rate are high. This seriously affects the efficiency of the laser ball implanting process and will also cause problems such as ball deviation and ball bouncing.

[0005] Chinese 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 the pushing mechanism is reset. The principle of the pushing structure is similar to that of loading a bullet, and the design is novel, but it involves a complex structure and is prone to jamming or ball blockage. In particular, cleaning the solder balls requires disassembly and cleaning the channels. At the same time, due to the squeezing of the thrust rod and the limiting rod, the solder balls are at risk of deformation, which increases the ball blockage rate at each channel and the holding unit.

[0006] Chinese patent CN105458446A invented a solder ball welding device, which uses a rotating drive member to drive the separation shaft to rotate, and the solder balls fall into the separation holes on the separation shaft, so that they are separated one by one and sent to the solder ball holding mechanism through the solder ball guide tube. Similarly, this structure will squeeze the solder balls, resulting in the risk of deformation of the solder balls, which in turn causes the problem of ball blocking.

[0007] Chinese patent CN201120305714.5 discloses a laser ball implantation system that can continuously feed solder balls into the working chamber. However, the elastic baffles and springs 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, resulting in a long return cycle and low transportation efficiency. The initial velocity direction of the solder ball ejected from the side into the working chamber is horizontal, which does not match the target welding direction (vertically downward), and the welding efficiency is low. Ball blockage and jamming problems are easily caused at the elastic baffles and disturbance structures. The solder balls in the ball delivery pipeline are squeezed by the disturbance structure to generate downward pressure, which easily causes the solder balls to deform.

[0008] Chinese 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 is convenient for fixing the diamond spray plate and ensuring 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 easily causes ball blockage at the nozzle.

[0009] Chinese patent CN207373657 U discloses a stackable anti-blocking hopper used in a twin-screw granulator, in which a vent pipe is provided to connect the inside and outside of the hopper to prevent material blockage. However, this anti-blocking structure is not suitable for quantitative feeding of small-sized solder balls.

[0010] The above-mentioned patent does not take into account the risk of ball blockage caused by solder ball stacking in the solder ball container in terms of structural design.

[0011] 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 for the ball feeding path and the nozzle to be blocked. The existing laser ball implanter ball separation structure mostly uses a ball separation disk to transport solder balls, 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 blockages or high idling rates. The most common ball blockage point is 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.

[0012] In the prior art, the diameter of the connection between the ball storage bin and the ball leakage hole gradually decreases, and the solder balls are easily accumulated in the ball leakage hole channel under the action of gravity. If the solder balls are smaller than 300 microns, the stacked and rubbed solder balls adhere to each other under the action of static electricity, and are easily affected by moisture and adsorbed into a mass under the action of capillary action. The smaller the solder ball, the smaller the ratio of the solder ball's gravity to the adsorption force, and the easier it is to block the ball. The second blockage point is at the nozzle, where the solder ball is stuck at the nozzle due to deformation of the solder ball or unstable parameters such as laser power. Summary of the invention

[0013] The technical problem to be solved by the present invention is to provide a laser ball planting structure and a ball planting method with anti-blocking function;

[0014] The solution adopted by the present invention to solve the technical problem is:

[0015] A laser ball implanting structure with anti-blocking function, comprising an upper structure with a ball storage bin, a ball distribution structure located below the upper structure, and a bottom structure located below the middle structure and provided with a ball spraying mechanism; the ball distribution structure is rotatably matched with the upper structure and the bottom structure and is used to spray the solder balls in the ball storage bin from the outlet of the ball spraying mechanism;

[0016] A plurality of groups of baffles are arranged in the ball storage bin, which are staggered vertically and form baffle channels; a pressurized air source is externally connected to the top of the ball storage bin; a pulse channel is arranged at the bottom of the ball storage bin, which is connected to the ball storage bin and provides a pulse airflow into the ball storage bin.

[0017] Through the setting of multiple groups of baffles and pulse channels, the top of the ball storage bin is connected to the pressurized gas source. Under the action of this gas source, the solder balls stacked on the upper baffle will be fed to the lower baffle, and in conjunction with the pulse gas source provided by the pulse channel, the solder balls in the ball storage bin are arranged in layers, so that the accumulation pressure of the stacked solder balls is dispersed, and the smooth flow of pressurized airflow and pulse airflow is guaranteed to avoid blockage of the stacked balls.

[0018] In some possible implementations, in order to realize the cooperation between the pulse gas source and the ball distribution plate to redistribute the solder balls;

[0019] The pulse channel is externally connected to a constant-pressure pulse air source, and the constant-pressure pulse air source provides a spiral upward pulse airflow into the ball storage bin through the pulse channel.

[0020] In some possible implementations, in order to effectively implement the ball planting of the solder balls delivered from the ball storage bin by the ball distribution structure through the ball spraying mechanism;

[0021] The ball separation structure is provided with a plurality of groups of ball leakage holes used in conjunction with the ball outlet holes and the ball spraying mechanism provided at the bottom of the ball storage bin; the plurality of groups of ball leakage holes are arranged at equal distances from the rotation axis of the ball separation structure and at equal intervals;

[0022] A group of cleaning channels which are used in conjunction with the ball leakage holes and are coaxially arranged with the ball outlet holes are arranged on the bottom structure, and the inner diameter of the cleaning channels is smaller than the inner diameter of the solder balls.

[0023] In some possible implementations, in order to effectively detect the number of solder balls in the ball storage bin;

[0024] The ball storage bin is also provided with a ball quantity detection channel, and the ball quantity detection channel is connected with a pressure sensor.

[0025] In some possible implementations, in order to realize the transfer of solder balls through the ball distribution structure and ensure the sealed connection between the ball distribution structure and the upper structure and the bottom structure;

[0026] The ball distribution structure includes a ball distribution plate provided with multiple sets of ball leakage holes, a sealing gasket which is mounted on the outer side of the ball distribution plate and forms a gap therebetween, and a rotating drive mechanism for driving the ball distribution plate to rotate; the sealing gasket is respectively sealed and connected to the upper structure and the lower structure.

[0027] In some possible implementations, in order to effectively control the rotation of the ball distribution plate, the solder balls are transferred to the ball spraying mechanism to implement ball planting;

[0028] The rotary drive mechanism includes a rotating shaft with one end passing through the upper structure, the middle structure, and the bottom structure in sequence, and a transmission pin for connecting the rotating shaft and the ball distribution plate; an installation cavity for installing the transmission pin is formed between the upper structure and the middle structure.

[0029] In some possible implementations, in order to prevent the ball distribution plate and the underlying structure from squeezing the solder balls, and to prevent the solder balls from slipping and not being able to enter the ball spraying mechanism;

[0030] The bottom structure is provided with a ring-shaped ball conveying groove located directly below the ball leakage hole; the depth of the ball conveying groove along the axial direction of the ball leakage hole is H, and the diameter of the welding ball is d, H=0.2d-0.4d.

[0031] In some possible implementations, in order to effectively implement ball planting through a ball spraying mechanism;

[0032] The ball spraying mechanism comprises a nozzle arranged at the bottom of the substructure and used in conjunction with the ball leakage hole, a laser generator installed on the superstructure and emitting a laser beam to one side of the nozzle through a laser channel arranged on the superstructure, and a nitrogen source connected to the nozzle and conveying nitrogen into the nozzle through a nitrogen channel arranged on the substructure;

[0033] A collecting channel connected with the laser channel, the nozzle and the nitrogen channel is arranged on the bottom structure.

[0034] In some possible implementations, the laser channel and the aggregation channel are externally connected to a pressure measuring device.

[0035] A ball planting method according to the laser ball planting structure with anti-blocking function described above specifically comprises the following steps:

[0036] During normal ball planting, the nitrogen channel is opened, and the pressure measuring device is used to measure the pressure; the pulse channel is opened, and the pressurizing channel is opened; the cleaning channel is closed, and the ball quantity detection channel is closed; the ball separation structure is controlled to rotate, and the solder balls falling from the ball storage bin are driven to rotate, and transported to the nozzle, and ejected from the nozzle;

[0037] When detecting the number of remaining balls in the ball storage bin, stop planting balls, open the ball quantity detection channel, close the cleaning channel, close the pulse channel, and close the pressurization channel;

[0038] When cleaning the ball blockage in the ball storage bin or the ball leakage hole, close the ball quantity detection channel, close the pressurization channel, close the pulse channel, open the cleaning channel and connect the cleaning channel to a constant pressure gas source;

[0039] When cleaning all the welding balls in the ball bin, close the ball quantity detection channel, close the pressurization channel, open the pulse channel and connect an external constant pressure pulse gas source, open the cleaning channel and connect an external constant pressure gas source, and open the ball adding port set above the ball storage bin.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] According to the principle of spherical particle stacking, the present invention provides baffles with equal vertical spacing in the ball storage bin, thereby dispersing the stacking pressure; a pressurized channel is provided to deliver balls to each level of baffles layer by layer, and the solder balls are blown to the baffles of the next level under the spiral downward airflow output by the pressurized channel, and the spiral airflow can prevent the solder balls from being deposited at the roots of the baffles for a long time;

[0042] The present invention provides a cleaning channel and a pulse channel, connects an external high-pressure air source and opens the ball storage bin ball adding port, so that the airflow can blow out the blocked balls, residues and other redundant objects at the ball leakage hole or the ball storage bin, thereby cleaning the blockage in the ball leakage hole and the ball storage bin;

[0043] The present invention arranges on the ball dividing plate airflow channels, valve holes, ball leakage holes, which are the same in number as the ball leakage holes and are used in conjunction with the pulse channel and the nitrogen channel, and are used in conjunction with the ball storage bin and the laser channel. The ball dividing plate is driven to rotate by a transmission pin, and the opening and closing of the valve holes and each channel are controlled to form a pulse airflow. At the same time, according to the density, diameter and stacking effect of the solder balls on the baffle plate, channels of different specifications and pressures can be designed to meet different ball blowing and ball sending effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the internal structure of the present invention;

[0045] Figure 2 A top view of the bottom layer structure of the present invention;

[0046] Figure 3 A top view of the ball storage bin of the present invention;

[0047] Figure 4 A top view of the ball distribution plate of the present invention;

[0048] Figure 5 It is a schematic diagram of the structure of the sealing gasket in the present invention;

[0049] Wherein: 1-upper structure, 2-bottom structure, 3-nozzle, 4-ball dividing plate, 5-transmission pin, 6-rotating shaft, 7-pressurization channel, 8-pulse channel, 9-cleaning channel, 10-ball delivery groove, 11-ball leakage hole, 12-sealing pad, 13-ball quantity detection channel, 14-ball storage bin, 15-baffle, 16-ball adding port, 17-connecting hole, 18-nitrogen channel, 19-laser generator, 20-laser channel, 21-pressure measuring device, 22-air flow channel, 23-pin hole, 24-valve hole, 25-screw hole. DETAILED DESCRIPTION

[0050] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity restriction, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] The present invention is described in detail below.

[0052] like Figure 1-Figure 5 As shown:

[0053] A laser ball implanting structure with anti-blocking function, comprising an upper structure 1 with a ball storage bin 14, a ball distribution structure located below the upper structure 1, and a bottom structure 2 located below the middle structure and provided with a ball spraying mechanism; the ball distribution structure is rotatably matched with the upper structure 1 and the bottom structure 2 and is used to spray the solder balls in the ball storage bin 14 from the outlet of the ball spraying mechanism;

[0054] A plurality of baffles 15 are arranged in the ball storage bin 14, which are staggered vertically and form baffle channels; a pressurized air source is externally connected to the top of the ball storage bin 14; a pulse channel 8 is arranged at the bottom of the ball storage bin 14, which is connected to the ball storage bin 14 and provides a pulse airflow into the ball storage bin 14;

[0055] Through the arrangement of multiple groups of baffles 15 and pulse channels 8; the top of the ball storage bin 14 is connected to the pressurized air source, and under the action of the air source, the airflow is spiraled downward by the baffles 15, and the solder balls stacked on the upper baffle 15 will be fed to the lower baffle 15, thereby arranging the solder balls in the ball storage bin 14 in layers, so that the stacking pressure of the stacked solder balls is dispersed to avoid clogging of the stacked balls; the pulse air source provided by the pulse channel 8 is used to intermittently blow up the stacked solder balls and then stack them, ensuring the smooth flow of pressurized airflow and pulse airflow, thereby effectively avoiding clogging of the solder balls.

[0056] In some possible implementations, in order to realize the redistribution of the solder balls by cooperating with the pulse gas source and the baffle 15;

[0057] The pulse channel 8 is externally connected to a constant-pressure pulse air source, and the constant-pressure pulse air source provides a spiral upward pulse airflow into the ball storage bin 14 through the pulse channel 8 .

[0058] Specifically, the constant pressure pulse gas source is arranged at the bottom of the bottom structure 2, and the pulse channel 8 sequentially passes through the bottom structure 2, the middle structure, and is connected to the bottom of the ball storage bin 14;

[0059] The ball storage bin 14 includes a cylindrical body with a ball adding port 16, a conical structure arranged below the cylindrical body and coaxially, and a discharge channel arranged coaxially with the conical structure and located at the small end of the conical structure; the pulse channel 8 is connected to the conical structure with a connecting hole 17 and is connected to the inside of the ball storage bin 14; the pulse channel 8 includes a vertical channel arranged vertically and passing through the bottom structure 2 and the middle structure, and an inclined channel 1 connected to the vertical channel and the ball storage bin 14, and the angle formed by the inclined channel 1 and the vertical channel is greater than 90°, that is, A>90°, so that a constant-pressure pulse gas source is transported from bottom to top into the ball storage bin 14, and cooperates with the baffle 15 to form a pulse airflow above the spiral; thereby realizing secondary stacking of solder balls, and cooperating with the pressurized channel 7 and the baffle to avoid blockage of solder balls.

[0060] In some possible implementations, in order to effectively implement the ball planting of the solder balls delivered from the ball storage bin 14 through the ball distribution structure through the ball spraying mechanism;

[0061] The ball separation structure is provided with a plurality of groups of ball leakage holes 11 used in conjunction with the ball outlet holes and the ball spraying mechanism provided at the bottom of the ball storage bin 14; the plurality of groups of ball leakage holes 11 are arranged at equal distances from the rotation axis of the ball separation structure and at equal intervals;

[0062] When the ball-distributing structure rotates, a group of ball-leaking holes 11 will be connected with the ball-out holes provided in the ball-storing bin 14, so that the solder balls enter the ball-leaking holes 11 from the ball-storing bin 14, and the solder balls in the ball-leaking holes 11 will be driven to rotate and transported to the ball-spraying mechanism under the rotation of the ball-distributing structure, so as to realize the ball-planting operation;

[0063] In order to avoid the blockage of the solder balls in the ball outlet hole, a group of cleaning channels 9 are provided on the bottom structure 2 to cooperate with the ball leakage holes 11 and to be coaxially arranged with the ball outlet hole;

[0064] The cleaning channel 9 is arranged so that when a blockage occurs, a force is applied from the bottom of the cleaning channel 9 to one side of the ball outlet hole, thereby cleaning the blocked part of the ball outlet hole; the inner diameter of the cleaning channel 9 is smaller than the inner diameter of the solder ball, thereby preventing the solder ball in the ball outlet hole from falling directly out of the cleaning channel 9;

[0065] Furthermore, each set of baffles 15 does not exceed 80% of the cross-sectional area of ​​the ball storage bin 14, thereby enabling the solder balls to fall.

[0066] In some possible implementations, in order to effectively detect the number of welding balls in the ball storage bin 14;

[0067] The ball storage bin 14 is also provided with a ball quantity detection channel 13, and the ball quantity detection channel 13 is connected to a pressure sensor;

[0068] Specifically, the ball quantity detection channel 13 is divided into two groups, one group is used as the air inlet channel, and the other group is used as the air outlet channel; pressure sensors are respectively installed on the two groups of channels. When the ball quantity in the ball storage bin 14 is detected, an external airflow is delivered to the air inlet channel and then discharged from the air outlet channel. The pressure drop value of the airflow in the ball storage bin 14 is measured by a pressure test, and the remaining solder balls in the ball storage bin 14 can be indirectly obtained; the ball planting operator can regularly check the remaining solder balls and replenish the balls; at the same time, when no balls are discharged continuously, the problem can be quickly checked without dismantling the overall structure.

[0069] In some possible implementations, in order to realize the transfer of solder balls through the ball separation structure and ensure the sealed connection between the ball separation structure and the upper mechanism and the bottom structure 2;

[0070] The ball distribution structure comprises a ball distribution plate 4 provided with a plurality of ball leakage holes 11, a sealing gasket 12 which is sleeved on the outer side of the ball distribution plate 4 and forms a gap therebetween, and a rotation driving mechanism for driving the ball distribution plate 4 to rotate; the sealing gasket 12 is respectively sealed and connected to the upper structure 1 and the lower structure 2;

[0071] Specifically, the sealing gasket 12 is provided with a screw hole 25, which is connected to the upper structure 1 and the bottom structure 2 by bolts; the sealing gasket 12 is sealed and connected to the upper structure 1 and the bottom structure 2 respectively, so as to prevent the gas source delivered to the device from leaking from this position; the sealing gasket 12 is provided with a circular chamber, the ball dividing plate 4 is disc-shaped and is located in the circular chamber, and there is a clearance fit between the inner side of the circular chamber and the outer side of the ball dividing plate 4, between the ball dividing plate 4 and the bottom structure 2, and between the ball dividing plate 4 and the upper structure 1, so as to ensure that the rotary drive mechanism can effectively control the ball dividing plate 4 to rotate, and can transfer the welding ball in the ball leakage hole 11 to the ball spraying mechanism;

[0072] Furthermore, the thickness of the sealing gasket 12 is L, the thickness of the ball dividing plate 4 is l, and L=1.1l-1.2l.

[0073] In some possible implementations, in order to effectively control the rotation of the ball distribution plate 4, the solder balls are transferred to the ball spraying mechanism to implement ball planting;

[0074] The rotary drive mechanism comprises a rotating shaft 6, one end of which passes through the upper structure 1, the middle structure, and the bottom structure 2 in sequence, and a transmission pin 5 for connecting the rotating shaft 6 with the ball distribution plate 4; a mounting cavity for installing the transmission pin 5 is formed between the upper structure 1 and the middle structure; a pin hole 23 connected with the transmission pin 5 is provided on the ball distribution plate 4;

[0075] The rotating shaft 6 rotates with the upper structure 1 and the lower structure 2, and the ball dividing plate 4 in the middle structure is mounted on the outer side of the rotating shaft 6 and connected to each other through the transmission pin 5; the transmission pin 5 is driven to rotate by the rotating shaft 6, and since the ball dividing plate 4 is connected to the transmission pin 5, the ball dividing plate 4 rotates around the axis of the rotating shaft 6.

[0076] In some possible implementations, in order to prevent the ball distribution plate 4 and the bottom structure 2 from squeezing the solder balls, and to prevent the solder balls from slipping and not being able to enter the ball spraying mechanism;

[0077] The bottom structure 2 is provided with a circular ball conveying groove 10 located directly below the ball leakage hole 11; the depth of the ball conveying groove 10 along the axial direction of the ball leakage hole 11 is H, and the diameter of the solder ball is d, H = 0.2d-0.4d;

[0078] The center of the ball conveying groove 10, the center of the circle formed by connecting the axis of the plurality of ball leakage holes 11, and the axis of the rotating shaft 6 are on the same straight line, and the ball conveying groove 10 is located directly below the circle formed by connecting the center of the plurality of ball leakage holes 11; in this way, the solder ball will be located in the ball conveying groove 10, and will move in the ball conveying groove 10 and move into the ball spraying mechanism under the driving direction of the rotating shaft 6. The setting of the ball conveying groove 10 will guide the movement of the solder ball and limit its random sliding on the bottom mechanism;

[0079] In some possible implementations, in order to effectively implement ball planting through a ball spraying mechanism;

[0080] The ball spraying mechanism comprises a nozzle 3 arranged at the bottom of the substructure 2 and used in conjunction with the ball leakage hole 11 and the ball delivery groove 10, a laser generator 19 installed on the superstructure 1 and emitting a laser beam into the nozzle 3 through a laser channel 20 arranged on the superstructure 1, and a nitrogen source connected to the nozzle 3 and conveying nitrogen into the nozzle 3 through a nitrogen channel 18 arranged on the substructure 2;

[0081] A collecting channel connected with the laser channel 20, the nozzle 3 and the nitrogen channel 18 is arranged on the bottom structure 2; the laser channel 20, the collecting channel and the nozzle 3 are coaxially arranged.

[0082] Specifically, when the ball leakage hole 11 is connected with the collecting channel and the laser channel 20, the solder ball in the ball leakage hole 11 will flow to the side of the nozzle 3; the nitrogen source is turned on to provide impact force for the solder ball to be ejected from the nozzle 3, and to keep the nozzle and the solder ball warm and isolate the solder ball from oxygen; the laser generator 19 emits a laser beam and focuses it on the surface of the solder ball, so that the solder ball melts quickly and can be ejected from the nozzle 3 under the action of nitrogen;

[0083] Furthermore, the laser channel 20 and the aggregation channel are coaxially arranged and form a group; the axis of the laser channel 20 is parallel to the axis of the ball storage bin 14 and is arranged vertically, and a nitrogen channel 18 parallel to the laser channel 20 is arranged on the upper structure 1. After passing through the middle structure, the nitrogen channel 18 is connected with the aggregation channel through the inclined channel 2. The inclined channel 2 is inclined and the angle formed by the intersection of its axis and the axis of the aggregation channel is B, and B<90°.

[0084] Furthermore, the axes of the nitrogen channel 18 and the pulse channel 8 are at the same distance from the axis of the rotating shaft 6, and the air flow channel 22 of the ball leakage hole 11 is provided on the ball distribution plate 4; the ball leakage hole 11 and the air flow channel 22 are staggered on the ball distribution plate 4, and are not in the same radial direction of the ball distribution plate 4, so that when the solder balls in the ball storage bin 14 fall to the ball leakage hole 11, the pulse channel 8 is in a closed state, and the constant pressure pulse gas source will not provide a spiral upward airflow into the ball storage bin 14, thereby preventing the solder balls from falling;

[0085] The number of airflow channels 22 can be specified according to the size of the solder balls. When the solder balls are small, the number is large, so that the airflow can enter the ball storage bin 14 more frequently and periodically to exert a spiral upward force on the solder balls to redistribute them. When there are multiple groups of airflow channels 22, they will be arranged at equal intervals. When the solder balls are large, the airflow channels 22 can also be arranged as one group.

[0086] like Figure 2 As shown, the rotating shaft 6 controls the ball distribution plate 4 to rotate clockwise. When a group of ball leakage holes 11 are connected with the laser channel 20 and the aggregation channel, due to the continuous rotation of the ball distribution plate 4, the nitrogen channel 18 will be connected with the aggregation channel through the air channel 22, and nitrogen will be transported into the aggregation channel. The nitrogen keeps the welding nozzle and the welding ball warm and isolates the welding ball from oxygen. Due to the action of the laser generator, the welding ball melts and is ejected from the nozzle 3 under the action of nitrogen; when a group of ball leakage holes 11 are connected with the laser channel 20 and the aggregation channel, the ball leakage holes 11 connected with the discharge port will fall into another group of welding balls at this time; when the nitrogen channel 18 is connected with the aggregation channel, the pulse channel 8 will also be connected with the ball storage bin 14 through another group of air channels 22; thereby, the opening and closing of the channel is realized by controlling the rotation of the ball distribution plate 4, and there is no need to set too many valves for control; it has a good working rhythm.

[0087] The distance between the axis of the laser channel 20 and the axis of the rotating shaft 6 is equal to the distance between the axis of the discharge port of the ball storage bin 14 and the axis of the rotating shaft 6, so that the solder balls in the ball leakage hole 11 can enter the bottom of the laser channel 20;

[0088] Furthermore, the pressurized gas source is arranged at the bottom of the bottom structure 2, and is delivered to the ball storage bin 14 through the pressurized gas channel 7; a valve hole 24 is arranged on the ball distribution plate 4, so that the pressurized gas channel 7 located at the upper structure 1 is connected with the part located at the bottom structure 2;

[0089] The valve hole 24 is circular or arc-shaped; when it is circular, it has the same cross-sectional size as the pressurized channel 7, and will provide a spiral downward airflow in the ball storage bin 14 periodically. The valve hole 24 is at least one group;

[0090] The present invention has a ball leakage hole 11, an air flow channel 22, and a valve hole 24 on the ball distribution plate 4, which have a simple structure and do not interfere with each other. The transmission pin 5 drives the ball distribution plate 4 to rotate, thereby completing the periodic opening and closing of each channel and the valve hole 24; channels with the same size and the same period in the annular direction share the same annular valve hole 24, and the structure is simple and stable.

[0091] In some possible embodiments, the laser channel 20 and the aggregation channel are externally connected to a pressure measuring device 21; the pressure measuring device 21 includes a group of air inlets, a group of air outlets, and pressure gauges arranged on the two groups of air outlets; an air flow is transported through the air inlet to the ball leakage hole 11 used to connect the laser channel 20 and the aggregation channel, and the pressures of the air flow entering the air inlet and the air flow going out of the air outlet are respectively tested by two groups of pressure gauges. By comparison, it is determined whether there is a ball in the ball leakage hole 11 connected to the laser channel 20 at one end and the aggregation channel at the other end, thereby controlling the movement of the rotating shaft 6 through the control system.

[0092] A ball planting method according to the laser ball planting structure with anti-blocking function described above specifically comprises the following steps:

[0093] During normal ball planting, the nitrogen channel 18 is opened, the pulse channel 8 is opened, and the pressurizing channel 7 is opened; the cleaning channel 9 is closed, and the ball quantity detection channel 13 is closed; the nitrogen gas source delivers nitrogen as a protective gas to the collection channel, and the pressure measuring device 21 performs pressure measurement to detect whether there is a ball in the ball leakage hole 11 located above the collection pipeline. If there is a ball, the laser transmitter is turned on to carry out the ball planting work;

[0094] If there is no ball, the ball distribution structure is controlled to rotate, driving the solder ball falling from the ball storage bin 14 to rotate and transport it to the nozzle 3, and the pressure measuring device 21 performs detection until there is a solder ball. The solder ball falls onto the nozzle under the action of the nitrogen gas source, and the laser generator 19 emits a laser beam to melt the solder ball, which is ejected from the nozzle for ball planting;

[0095] When the number of remaining balls in the ball storage bin 14 is detected, the ball planting is stopped, the ball quantity detection channel 13 is opened, the cleaning channel 9 is closed, the pulse channel 8 is closed, and the pressurizing channel 7 is closed; the air flow enters the ball storage bin 14 from the air inlet channel and is discharged from the air outlet channel, and two groups of pressure sensors monitor the pressure of the air inlet and the air outlet respectively, and the number of remaining balls in the ball storage bin 14 is obtained;

[0096] When cleaning the ball stuck in the ball storage bin 14 or the ball leakage hole 11, the ball quantity detection channel 13 is closed, the pressurization channel 7 is closed, the pulse channel 8 is closed, the cleaning channel 9 is opened, and the cleaning channel 9 is connected to an external constant pressure air source, and the constant pressure airflow is delivered into the cleaning channel 9 to clean the ball stuck in the ball leakage hole 11 or the ball storage bin 14;

[0097] When cleaning all the welding balls in the ball storage bin 14 , close the ball quantity detection channel 13 , close the pressurization channel 7 , open the pulse channel 8 and connect an external constant pressure pulse gas source , open the cleaning channel 9 and connect an external constant pressure gas source , and open the ball adding port 16 set above the ball storage bin 14 .

[0098] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A laser ball implantation structure with anti-blocking function, characterized in that: It comprises an upper structure with a ball storage bin, a ball distribution structure located below the upper structure, and a bottom structure located below the middle structure and provided with a ball spraying mechanism; the ball distribution structure is rotatably matched with the upper structure and the bottom structure and is used to spray the welding balls in the ball storage bin from the outlet of the ball spraying mechanism; A plurality of groups of baffles are arranged in the ball storage bin, which are staggered vertically and form baffle channels; a pressurized air source is externally connected to the top of the ball storage bin; a pulse channel is arranged at the bottom of the ball storage bin, which is connected to the ball storage bin and provides a pulse airflow into the ball storage bin.

2. The laser ball implanting structure with anti-blocking function according to claim 1, characterized in that: The pulse channel is externally connected to a constant-pressure pulse air source, and the constant-pressure pulse air source provides a spiral upward pulse airflow into the ball storage bin through the pulse channel.

3. The laser ball implanting structure with anti-blocking function according to claim 1, characterized in that: The ball separation structure is provided with a plurality of groups of ball leakage holes used in conjunction with the ball outlet holes and the ball spraying mechanism provided at the bottom of the ball storage bin; the plurality of groups of ball leakage holes are arranged at equal distances from the rotation axis of the ball separation structure and at equal intervals; A group of cleaning channels which are used in conjunction with the ball leakage holes and are coaxially arranged with the ball outlet holes are arranged on the bottom structure, and the inner diameter of the cleaning channels is smaller than the inner diameter of the solder balls.

4. The laser ball implantation structure with anti-blocking function according to claim 1, characterized in that: The ball storage bin is also provided with a ball quantity detection channel, and the ball quantity detection channel is connected with a pressure sensor.

5. The laser ball implantation structure with anti-blocking function according to claim 3, characterized in that: The ball distribution structure includes a ball distribution plate provided with multiple sets of ball leakage holes, a sealing gasket which is mounted on the outer side of the ball distribution plate and forms a gap therebetween, and a rotating drive mechanism for driving the ball distribution plate to rotate; the sealing gasket is respectively sealed and connected to the upper structure and the lower structure.

6. The laser ball implantation structure with anti-blocking function according to claim 5, characterized in that: The rotary drive mechanism includes a rotating shaft with one end passing through the upper structure, the middle structure, and the bottom structure in sequence, and a transmission pin for connecting the rotating shaft and the ball distribution plate; an installation cavity for installing the transmission pin is formed between the upper structure and the middle structure.

7. The laser ball implantation structure with anti-blocking function according to claim 3, characterized in that: The bottom structure is provided with a ring-shaped ball conveying groove located directly below the ball leakage hole; the depth of the ball conveying groove along the axial direction of the ball leakage hole is H, and the diameter of the welding ball is d, H=0.2d-0.4d.

8. The laser ball implantation structure with anti-blocking function according to claim 1, characterized in that: The ball spraying mechanism comprises a nozzle arranged at the bottom of the substructure and used in conjunction with the ball leakage hole, a laser generator installed on the superstructure and emitting a laser beam to one side of the nozzle through a laser channel arranged on the superstructure, and a nitrogen source connected to the nozzle and conveying nitrogen into the nozzle through a nitrogen channel arranged on the substructure; A collecting channel connected with the laser channel, the nozzle and the nitrogen channel is arranged on the bottom structure.

9. The laser ball implantation structure with anti-blocking function according to claim 8, characterized in that: The laser channel and the aggregation channel are externally connected with a pressure measuring device.

10. A ball implanting method for a laser ball implanting structure with anti-blocking function according to any one of claims 1 to 9, characterized in that: The specific steps include: During normal ball planting, the nitrogen channel is opened and the pressure measuring device is used to measure the pressure; the pulse channel is opened and the pressurization channel is opened; Close the cleaning channel and the ball quantity detection channel; control the rotation of the ball separation structure to drive the solder balls falling from the ball storage bin to rotate, and transport them to the nozzle and spray them out from the nozzle; When detecting the number of remaining balls in the ball storage bin, stop planting balls, open the ball quantity detection channel, close the cleaning channel, close the pulse channel, and close the pressurization channel; When cleaning the ball blockage in the ball storage bin or the ball leakage hole, close the ball quantity detection channel, close the pressurization channel, close the pulse channel, open the cleaning channel and connect the cleaning channel to a constant pressure gas source; When cleaning all the welding balls in the ball bin, close the ball quantity detection channel, close the pressurization channel, open the pulse channel and connect an external constant pressure pulse gas source, open the cleaning channel and connect an external constant pressure gas source, and open the ball adding port set above the ball storage bin.

Images