A laser ball planting defect repair and tin removal integrated device and a laser welding method

Abstract

The application relates to the technical field of laser welding, and discloses a laser ball planting defect repairing and tin removing integrated device and a laser welding method.The device comprises a support serving as the support of the whole device; three multi-axis platforms, one of which is provided with a laser on the outer side, the bottom end of the laser is provided with a tin ball spraying device, and one side of the tin ball spraying device is provided with a nitrogen conveying device; two of the multi-axis platforms are fixedly connected to the two ends of the support respectively, and the other multi-axis platform is connected with the multi-axis platform on the top through a sliding block. Infrared light is emitted by the laser to heat and melt tin balls, the melted tin balls are blown to the welding pads by nitrogen, and complete welding points are formed after cooling; for the defective welding points which are not qualified for welding, the laser can be used for secondary heating and melting, and the solder can be blown away by nitrogen, so that secondary ball planting welding is realized, and the precision and efficiency of ball planting welding are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, specifically to an integrated device for repairing and desoldering defects in laser ball bonding and a laser welding method. Background Technology

[0002] Laser ball-mounting technology is widely used in the electronics manufacturing industry due to its unique advantages such as localized heating, non-contact heating, rapid heating, and rapid cooling. When repairing defects in integrated circuit (IC) balls and removing solder from them, this technology uses a laser as an energy source, combined with appropriate devices and methods, to achieve precise repair and solder removal of IC balls.

[0003] However, traditional electronic assembly equipment suffers from low welding efficiency and insufficient processing precision. Furthermore, numerous defects during the welding process lead to circuit board damage or even scrap, resulting in significant waste. To address this, this invention proposes an integrated device for laser ball-mounting defect repair and desoldering, as well as a laser welding method. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an integrated device for laser ball-mounting defect repair and desoldering, as well as a laser welding method. This solves the problems of low welding efficiency, insufficient processing precision, and numerous defects during the welding process that lead to circuit board damage in existing technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an integrated device for laser ball-mounting defect repair and desoldering, comprising:

[0006] A support frame, used to support the entire device;

[0007] Three multi-axis platforms, one of which has a laser mounted on its outer side, a solder ball ejection device mounted at the bottom of the laser, and a nitrogen delivery device mounted on one side of the solder ball ejection device;

[0008] Two of the multi-axis platforms are fixedly connected to both ends of the bracket, and the other multi-axis platform is connected to the top multi-axis platform via a sliding block.

[0009] Preferably, the multi-axis platform includes three moving platform supports. The top of the bottom moving platform support is fixedly connected to a longitudinal guide rail. The side of the middle moving platform support away from the sliding block is fixedly connected to a vertical guide rail. The top of the top moving platform support is fixedly connected to a transverse guide rail. One end of each of the longitudinal, vertical, and transverse guide rails is fixedly connected to a drive motor. The output end of the drive motor is fixedly connected to a coupling. One end of the coupling is fixedly connected to a ball screw. A processing platform is mounted on the outside of the ball screw.

[0010] Preferably, the laser includes a laser generating device, a beam adjuster is installed in the middle of the laser generating device, a knob is installed on the outside of the beam adjuster, and the laser generating device has a beam inlet, a light guide cavity, a beam outlet and a light output channel arranged sequentially from top to bottom inside.

[0011] Preferably, the three processing platforms are slidably connected to the outside of the transverse guide rail, the vertical guide rail and the longitudinal guide rail respectively, and the two ends of the three ball screws are rotatably connected to the inside of the transverse guide rail, the vertical guide rail and the longitudinal guide rail respectively.

[0012] Preferably, the top of the sliding block is fixedly connected to one side of the top processing platform, and the rear side of the middle moving platform bracket is fixedly connected to the front side of the sliding block.

[0013] Preferably, the beam modulator is located between the beam inlet and the light guide cavity.

[0014] Preferably, the solder ball ejection device includes a welding joint, a nozzle is fixedly connected to the bottom end of the welding joint, a sealing optical lens is installed inside the bottom end of the welding joint, and a fixing sleeve is fixedly connected to both ends of the welding joint. A solder ball holding tray is installed at the bottom of the nozzle. The solder ball holding tray is an optical lens, and the small hole in the center of the tray is smaller than the diameter of the solder ball. A solder ball outlet is opened on one side of the inner wall of the nozzle, and a gas outlet is opened on the other side of the inner wall of the nozzle. A solder ball conveying channel is fixedly connected to the outer wall of the solder ball outlet. A dispensing disc is installed on the side of the solder ball conveying channel away from the nozzle. A ball storage chamber is fixedly connected to one end of the solder ball conveying channel. A solder ball inlet is fixedly connected to the top of the ball storage chamber. A ball storage chamber hole is opened on the side of the ball storage chamber near the solder ball conveying channel.

[0015] Preferably, the nitrogen delivery device includes a slot shell, with conduits on both sides inside the slot shell. A gas nozzle is fixedly connected to one end of the front conduit. A rotating joint is installed on the side of the slot shell away from the gas nozzle. The outer side of the front conduit is installed on the inner side of the rotating joint. The outer side of the rear conduit is fixedly connected to the inside of the slot shell. A valve is installed at the end of each of the two conduits away from the gas nozzle.

[0016] Preferably, the top end of the welding joint and the bottom end of the light-emitting channel are fixedly connected, the small hole of the ball storage chamber and the solder ball conveying channel are connected, and the outer wall of the gas inlet and the conduit on the rear side are connected.

[0017] A laser welding method for an integrated laser ball-mounting defect repair and desoldering device includes the following steps:

[0018] Step 1: Turn off the solder ball dispensing disc and empty the solder balls from the solder ball collection tray;

[0019] Step 2: Adjust the position of the nozzle so that it is aimed at the defective weld point;

[0020] Step 3: Adjust the position of the front conduit so that the gas nozzle is aimed at the welding point, and adjust the nitrogen valve connected to the front conduit to control the nitrogen flow rate.

[0021] Step 4: Turn on the laser, adjust the appropriate spot size, and when the laser heats and melts the solder joint to a liquid state, nitrogen gas ejected from the gas nozzle will blow the solder away.

[0022] Step 5: Open the solder ball dispensing disc and add solder balls;

[0023] Step 6: Close the valve connected to the front conduit, retract the front conduit into the slot housing, and adjust the valve of the rear conduit to purge nitrogen gas.

[0024] Step 7: Adjust the position of the nozzle so that it is aligned with the solder pad;

[0025] Step 8: Turn on the laser, adjust the appropriate spot size, the laser heats and melts the solder ball, and the nitrogen gas introduced through the rear conduit blows the molten solder onto the pad, where it cools to form a solder joint.

[0026] This invention provides an integrated device for laser ball-mounting defect repair and desoldering, as well as a laser welding method. It offers the following advantages:

[0027] This invention utilizes a support frame, a multi-axis platform, a laser, a solder ball ejection device, and a nitrogen delivery device. Solder balls in the storage chamber are conveyed through a solder ball delivery pipe and placed on a solder ball receiving plate at the bottom of the nozzle. The laser emits infrared light to heat and melt the solder balls, and then nitrogen blows the molten solder balls onto the solder pads. After cooling, complete solder joints are formed. For defective solder joints that do not meet the welding standards, the laser can reheat and melt them, and then nitrogen can blow away the solder, thereby achieving secondary ball placement and welding, which greatly improves the accuracy and efficiency of ball placement and welding. Attached Figure Description

[0028] Figure 1 This is a perspective view of the present invention;

[0029] Figure 2 This is a schematic diagram of the multi-axis platform structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the transverse guide rail structure of the present invention;

[0031] Figure 4 This is a schematic diagram of the vertical guide rail structure of the present invention;

[0032] Figure 5 This is a schematic diagram of the laser generating device of the present invention;

[0033] Figure 6 This is a schematic diagram of the welded joint structure of the present invention;

[0034] Figure 7 This is a schematic diagram of the solder ball conveying channel structure of the present invention;

[0035] Figure 8 This is a schematic diagram of the solder ball holding tray of the present invention;

[0036] Figure 9 This is a schematic diagram of the ball storage chamber structure of the present invention;

[0037] Figure 10 This is a schematic diagram of the card slot shell structure of the present invention;

[0038] Figure 11 This is a flowchart of the process of the present invention.

[0039] The components include: 1. Support frame; 2. Multi-axis platform; 201. Moving platform support frame; 202. Horizontal guide rail; 203. Vertical guide rail; 204. Longitudinal guide rail; 205. Ball screw; 206. Coupling; 207. Drive motor; 208. Machining platform; 3. Laser; 301. Laser generator; 302. Light guide cavity; 303. Light output channel; 304. Beam inlet; 305. Beam outlet; 306. Beam spot adjuster; 307. Knob; 4. Solder ball ejection device. 401. Welding joint; 402. Nozzle; 403. Ball storage chamber; 404. Solder ball conveying channel; 405. Fixed sleeve; 406. Sealed optical lens; 407. Solder ball holding tray; 408. Solder ball outlet; 409. Gas inlet; 4010. Distributing disc; 4011. Solder ball inlet; 4012. Small hole in the ball storage chamber; 5. Nitrogen conveying device; 501. Gas nozzle; 502. Conduit; 503. Slot housing; 504. Rotary joint; 6. Sliding block. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example:

[0042] Please see the appendix Figure 1 -Appendix Figure 11 This invention provides an integrated device for laser ball-mounting defect repair and desoldering, comprising:

[0043] Support 1 serves as a support for the entire device;

[0044] Three multi-axis platforms 2, one of which has a laser 3 mounted on its outer side, allowing the laser 3 to move along the Z-axis for easy position adjustment. A solder ball ejector 4 is mounted at the bottom of the laser 3 for adding solder balls for laser welding. A nitrogen delivery device 5 is mounted on one side of the solder ball ejector 4 for protection during laser welding and desoldering.

[0045] Two of the multi-axis platforms 2 are fixedly connected to both ends of the bracket 1, and another multi-axis platform 2 is connected to the top multi-axis platform 2 through the sliding block 6. Through the cooperation of the three multi-axis platforms 2, the position of the solder pad can be moved along the Y-axis, and the position of the laser 3 can be moved along the plane formed by the X-axis and Z-axis to adjust the position of the laser 3.

[0046] The multi-axis platform 2 includes three moving platform supports 201. The bottom moving platform support 201 has a longitudinal guide rail 204 fixedly connected to its top. The middle moving platform support 201 has a vertical guide rail 203 fixedly connected to its side away from the sliding block 6. The top moving platform support 201 has a transverse guide rail 202 fixedly connected to its top. The guide rails in the three directions can ensure that the laser 3 and the pad can be flexibly adjusted, which is convenient for subsequent desoldering and soldering repair operations. A drive motor 207 is fixedly connected to one end of the longitudinal guide rail 204, the vertical guide rail 203, and the transverse guide rail 202. A coupling 206 is fixedly connected to the output end of the drive motor 207. A ball screw 205 is fixedly connected to one end of the coupling 206. A processing platform 208 is mounted on the outside of the ball screw 205. The drive motor 207 drives the coupling 206 to rotate, thereby enabling the coupling 206 to drive the ball screw 205 to run, which in turn enables the ball screw 205 to drive the processing platform 208 mounted on it to move.

[0047] The laser 3 includes a laser generating device 301, which generates a laser beam. A beam adjuster 306 is mounted in the center of the laser generating device 301 to change the spatial distribution and shape of the laser beam to achieve specific optical targets. It can adjust the laser beam spot, changing its size, shape, focusing properties, and energy distribution to meet the needs of specific applications. A knob 307 is mounted on the outside of the beam adjuster 306; rotating the knob 307 adjusts the working state of the beam adjuster 306. The laser generating device 301 has, from top to bottom, a beam inlet 304, a light guide cavity 302, a beam outlet 305, and a light exit channel 303.

[0048] Three processing platforms 208 are slidably connected to the outside of the horizontal guide rail 202, vertical guide rail 203, and longitudinal guide rail 204, respectively. The three guide rails limit the movement of the processing platforms 208, allowing the three ball screws 205 to move and adjust the position for laser welding repair or desoldering. The two ends of the three ball screws 205 are rotatably connected inside the horizontal guide rail 202, vertical guide rail 203, and longitudinal guide rail 204, respectively. This allows the ball screws 205 to move the top processing platform 208 when they rotate.

[0049] The top of the sliding block 6 is fixedly connected to one side of the top processing platform 208, and the rear side of the middle moving platform bracket 201 is fixedly connected to the front side of the sliding block 6. The sliding block 6 is driven to translate by the multi-axis platform 2 at the top, thereby driving the laser 3 to translate.

[0050] The beam modulator 306 is located between the beam inlet 304 and the light guide cavity 302, so that when the laser generator 301 emits laser light, the laser light will pass through the pre-adjusted beam modulator 306 and melt the solder ball.

[0051] The solder ball ejection device 4 includes a solder joint 401, which is a cylindrical structure. A nozzle 402 is fixedly connected to the bottom of the solder joint 401, which ejects molten solder for soldering and repairing circuit boards. A sealing optical lens 406 is installed inside the bottom of the solder joint 401 to prevent nitrogen escape while allowing the laser beam to pass smoothly through the solder joint 401 and act on the solder ball. Fixed sleeves 405, also cylindrical structures, are fixedly connected to both ends of the solder joint 401, with the interior of the sleeve tightly fitted to the outer surface of the solder joint 401 to further prevent nitrogen leakage. A solder ball receiving tray 407, which is an optical lens, is installed at the bottom of the nozzle 402. The small hole at the center of the tray is smaller than the diameter of the solder ball; only the size of the small hole needs to be slightly smaller than the diameter of the solder ball. The melted solder ball, heated by the laser, drips down along the small hole. A solder ball outlet 408 is provided on one side of the inner wall of the nozzle 402, through which solder balls enter the solder ball receiving tray 407. A gas inlet 409 is provided on the other side of the inner wall of the nozzle 402, allowing nitrogen gas to enter the nozzle 402 and spray molten solder onto the circuit board below for repair. A solder ball conveying channel 404 is fixedly connected to the outer wall of the solder ball outlet 408 for conveying solder balls to the solder ball receiving tray 407. A dispensing disc 4010 is installed on the side of the solder ball conveying channel 404 away from the nozzle 402, and the dispensing disc 4010 is controlled to ensure that one solder ball passes through at a time. A ball storage chamber 403 is fixedly connected to one end of the solder ball conveying channel 404, and the angle formed by the solder ball conveying channel 404 and the horizontal plane is 15° to facilitate the smooth passage of solder balls to the center of the solder ball receiving tray 407. A solder ball inlet 4011 is fixedly connected to the top of the ball storage chamber 403. Solder balls are added into the ball storage chamber 403 through the solder ball inlet 4011. A small hole 4012 is provided on the side of the ball storage chamber 403 near the solder ball conveying channel 404. Solder balls inside the ball storage chamber 403 can enter the solder ball conveying channel 404 through the small hole 4012, and one solder ball passes through at a time under the action of the dispensing disc 4010.

[0052] The nitrogen delivery device 5 includes a slot housing 503. Inside the slot housing 503, on both sides, are conduits 502. The front conduit 502 is used for nitrogen delivery during desoldering, and the rear conduit 502 is used for nitrogen delivery during soldering and ball-mounting. One end of the front conduit 502 is fixedly connected to a gas nozzle 501, which precisely guides the sprayed nitrogen to the molten solder on the circuit board for desoldering. Inside the slot housing 503, on the side away from the gas nozzle 501, is a rotary joint 504. The rotary joint 504 is adjustable from 0° to 60° to better ensure the gas nozzle 501 is aligned with the solder pad. The outer side of the front conduit 502 is installed inside the rotary joint 504, and the outer side of the rear conduit 502 is fixedly connected inside the slot housing 503. Both conduits 502 are flexible hoses, allowing the nitrogen delivery device 5 to move with the laser 3. Valves are installed at the ends of both conduits 502 away from the gas nozzle 501, making it easier to control the delivery of nitrogen.

[0053] The top end of the welding joint 401 is fixedly connected to the bottom end of the light-emitting channel 303, and the through hole at the top of the welding joint 401 is connected to the through hole at the bottom of the light-emitting channel 303, allowing the laser beam to enter the nozzle 402. The small hole 4012 in the ball storage chamber is connected to the solder ball conveying channel 404, allowing the solder ball to enter the solder ball conveying channel 404 and then onto the solder ball holding tray 407. The outer wall of the gas inlet 409 is connected to the rear conduit 502, allowing the nitrogen generated by the nitrogen conveying device 5 to enter the nozzle 402 and blow out the molten solder ball for repair.

[0054] A laser welding method for an integrated laser ball-mounting defect repair and desoldering device includes the following steps:

[0055] Step 1: Turn off the solder ball dispensing disc 4010 and empty the solder balls on the solder ball receiving tray 407;

[0056] Step 2: Adjust the position of nozzle 402 so that it is aligned with the defective weld point;

[0057] Step 3: Adjust the position of the front conduit 502 so that the gas nozzle 501 is aligned with the weld point, and adjust the nitrogen valve connected to the front conduit 502 to control the nitrogen flow rate.

[0058] Step 4: Turn on laser 3, adjust the appropriate spot size, and when the laser heats and melts the solder joint to a liquid state, the nitrogen gas ejected by the gas nozzle 501 blows the solder away.

[0059] Step 5: Open the solder ball distribution disc 4010 and add solder balls;

[0060] Step 6: Close the valve connected to the front conduit 502, retract the front conduit 502 into the slot housing 503, and adjust the valve of the rear conduit 502 to purge nitrogen gas.

[0061] Step 7: Adjust the position of nozzle 402 so that it is aligned with the solder pad;

[0062] Step 8: Turn on laser 3, adjust the appropriate spot size, the laser heats and melts the solder ball, and the nitrogen gas introduced through the rear conduit 502 blows the molten solder onto the pad and cools to form a solder joint.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated device for laser ball-mounting defect repair and desoldering, characterized in that, include: The bracket (1) serves as a support for the entire device; Three multi-axis platforms (2), one of which has a laser (3) mounted on its outer side, a solder ball ejection device (4) mounted on its bottom end, and a nitrogen delivery device (5) mounted on one side of the solder ball ejection device (4). Two of the multi-axis platforms (2) are fixedly connected to both ends of the bracket (1), and the other multi-axis platform (2) is connected to the top multi-axis platform (2) through a sliding block (6); The laser (3) includes a laser generating device (301), a beam adjuster (306) is installed in the middle of the laser generating device (301), a knob (307) is installed on the outside of the beam adjuster (306), and the laser generating device (301) has a beam inlet (304), a light guide cavity (302), a beam outlet (305) and a light output channel (303) arranged sequentially from top to bottom inside the laser generating device (301). The solder ball ejection device (4) includes a solder joint (401), a nozzle (402) is fixedly connected to the bottom end of the solder joint (401), a sealed optical lens (406) is installed inside the bottom end of the solder joint (401), and fixed sleeves (405) are fixedly connected to both ends of the outside of the solder joint (401). A solder ball holding tray (407) is installed at the bottom of the nozzle (402). The solder ball holding tray (407) is an optical lens, and the small hole in the center of the tray is smaller than the diameter of the solder ball. A solder ball outlet (408) is opened on one side of the inner wall of the nozzle (402). (402) A gas inlet (409) is provided on the other side of the inner wall. A solder ball conveying channel (404) is fixedly connected to the outer wall of the solder ball outlet (408). A dispensing disc (4010) is installed on the side of the solder ball conveying channel (404) away from the nozzle (402). A ball storage chamber (403) is fixedly connected to one end of the solder ball conveying channel (404). A solder ball inlet (4011) is fixedly connected to the top of the ball storage chamber (403). A ball storage chamber hole (4012) is provided on the side of the ball storage chamber (403) close to the solder ball conveying channel (404). The nitrogen delivery device (5) includes a slot shell (503), and conduits (502) are provided on both sides inside the slot shell (503). A gas nozzle (501) is fixedly connected to one end of the front conduit (502). A rotating joint (504) is installed on the side of the slot shell (503) away from the gas nozzle (501). The outer side of the front conduit (502) is installed on the inner side of the rotating joint (504). The outer side of the rear conduit (502) is fixedly connected to the inside of the slot shell (503). A valve is installed at the end of each of the two conduits (502) away from the gas nozzle (501). The top end of the welding joint (401) and the bottom end of the light-emitting channel (303) are fixedly connected. The small hole (4012) of the ball storage chamber and the solder ball conveying channel (404) are connected. The outer wall of the gas inlet (409) and the conduit (502) on the rear side are connected.

2. The integrated laser ball-mounting defect repair and desoldering device according to claim 1, characterized in that, The multi-axis platform (2) includes three moving platform supports (201). The top of the bottom moving platform support (201) is fixedly connected to a longitudinal guide rail (204). The side of the middle moving platform support (201) away from the sliding block (6) is fixedly connected to a vertical guide rail (203). The top of the top moving platform support (201) is fixedly connected to a transverse guide rail (202). One end of each of the longitudinal guide rail (204), the vertical guide rail (203), and the transverse guide rail (202) is fixedly connected to a drive motor (207). The output end of the drive motor (207) is fixedly connected to a coupling (206). One end of the coupling (206) is fixedly connected to a ball screw (205). A processing platform (208) is installed on the outside of the ball screw (205).

3. The integrated laser ball-mounting defect repair and desoldering device according to claim 2, characterized in that, The three processing platforms (208) are slidably connected to the outside of the horizontal guide rail (202), the vertical guide rail (203) and the longitudinal guide rail (204), respectively, and the two ends of the three ball screws (205) are rotatably connected to the inside of the horizontal guide rail (202), the vertical guide rail (203) and the longitudinal guide rail (204), respectively.

4. The integrated laser ball-mounting defect repair and desoldering device according to claim 2, characterized in that, The top of the sliding block (6) is fixedly connected to one side of the top processing platform (208), and the rear side of the middle moving platform bracket (201) is fixedly connected to the front side of the sliding block (6).

5. The integrated laser ball-mounting defect repair and desoldering device according to claim 1, characterized in that, The beam modulator (306) is located between the beam inlet (304) and the light guide cavity (302).

6. A laser welding method for an integrated laser ball-mounting defect repair and desoldering device, characterized in that, A laser-assisted ball-mounting defect repair and desoldering integrated device according to any one of claims 1-5 includes the following steps: Step 1: Turn off the solder ball dispensing disc (4010) and empty the solder balls on the solder ball collection tray (407); Step 2: Adjust the position of the nozzle (402) so that it is aligned with the defective weld point; Step 3: Adjust the position of the front conduit (502) so that the gas nozzle (501) is aligned with the welding point, and adjust the nitrogen valve connected to the front conduit (502) to control the nitrogen flow rate; Step 4: Turn on the laser (3), adjust the appropriate spot size, and when the laser heats and melts the solder joint to a liquid state, the nitrogen gas ejected from the gas nozzle (501) blows the solder away; Step 5: Open the solder ball distribution disc (4010) and add solder balls; Step 6: Close the valve connected to the front conduit (502), retract the front conduit (502) into the slot housing (503), and adjust the valve of the rear conduit (502) to purge nitrogen gas. Step 7: Adjust the position of the nozzle (402) so that it is aligned with the pad; Step 8: Turn on the laser (3), adjust the appropriate spot size, the laser heats and melts the solder ball, and the nitrogen gas introduced through the rear conduit (502) blows the molten solder onto the pad and cools to form a solder joint.

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