Computer circuit board soldering equipment and solder joint detection method

Abstract

The present invention belongs to the technical field of welding equipment, and specifically relates to a computer circuit board soldering equipment and a solder joint detection method, comprising a machine platform, a stand fixedly assembled on the surface of the machine platform, and a track 2 fixedly assembled on one side of the top of the stand, a slider slidably assembled on one side of the track 2 through a track machine, a track 3 fixedly assembled on the outer side of the slider, a side frame slidably assembled on the outer side of the track 3 through a track machine, a laser generator for generating laser light fixedly assembled below the side frame, a tin bar wire feeding mechanism for conveying tin bars fixedly assembled on the outer side of the side frame, a rolling mechanism for changing the surface morphology of the tin bar is arranged inside the tin bar wire feeding mechanism, and a temperature control mechanism for controlling the cooling speed of the solder joint is arranged from one side of the laser generator to the bottom. The present invention can prepare micro grooves on the surface of the tin bar, improve the light energy absorption rate, and can also solve the problem of rapid cooling of the solder joint.

Description

Technical Field

[0001] The invention belongs to the technical field of welding equipment, and in particular relates to a computer circuit board soldering equipment and a soldering point detection method. Background Art

[0002] Laser welding is an efficient and precise welding method that uses a high-energy-density laser beam as a heat source. The welding process is a heat conduction type, that is, the laser radiation heats the workpiece surface, and the surface heat diffuses to the inside through heat conduction. By controlling parameters such as the width, energy, peak power and repetition frequency of the laser pulse, the workpiece is melted to form a specific molten pool. Due to its unique advantages, it has been successfully used in the precision welding of micro and small parts.

[0003] Problems with existing technologies:

[0004] Low energy conversion efficiency: The energy conversion efficiency of laser soldering machines is usually less than 10%, which means that a large part of the energy is wasted during the welding process. Specifically, it can be seen in the following points: (i) Low material absorption rate: The heating of the material depends on its absorption of the laser. The absorption rate of the metal to the laser is affected by many factors. If the absorption rate of the material is low, then when the laser is irradiated on the material, most of the energy will be reflected or scattered, and only a small part of the energy will be absorbed by the material and converted into heat energy; (ii) The transfer and dissipation of heat energy inside the material: Even if the material absorbs the laser energy and converts it into heat energy, the transfer and dissipation of this heat energy inside the material will also affect the energy conversion efficiency. For example, if the thermal conductivity of the material is poor, the speed of heat transfer inside the material will be very slow, resulting in reduced welding efficiency; at the same time, if there is a large amount of heat loss during the welding process (such as dissipation to the surrounding environment through radiation, heat conduction, etc.), the overall energy conversion efficiency will also be reduced;

[0005] Risk of welding defects: Rapid solidification of the solder joint may lead to problems such as porosity and embrittlement, which may affect the strength and reliability of the welded joint. Summary of the invention

[0006] The purpose of the present invention is to provide a computer circuit board soldering equipment and a solder joint detection method, which can prepare micro grooves on the surface of the tin bar, improve the light energy absorption rate, and solve the problem of rapid cooling of the solder joint.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A computer circuit board soldering device comprises a machine platform, a stand fixedly assembled on the surface of the machine platform, and a track 2 fixedly assembled on one side of the top of the stand, a slider slidably assembled on one side of the track 2 through a track machine, a track 3 fixedly assembled on the outer side of the slider, a side frame slidably assembled on the outer side of the track 3 through a track machine, a laser generator for generating laser light fixedly assembled below the side frame, a tin wire feeding mechanism for conveying tin bars fixedly assembled on the outer side of the side frame, a rolling mechanism for changing the surface morphology of the tin bars arranged inside the tin wire feeding mechanism, and a temperature control mechanism for controlling the cooling speed of solder joints arranged from one side of the laser generator to the bottom;

[0009] V-shaped micro grooves are prepared on the surface of the tin bar by a rolling mechanism, so that the laser light is reflected and absorbed multiple times on the surface;

[0010] The temperature control mechanism is used to change the instantaneous temperature drop of the soldering point to eliminate the residual stress in the soldering area.

[0011] A track 1 is fixedly installed on the surface of the machine, and a loading platform is slidably assembled on the surface of the track 1 through a track machine.

[0012] The bottom end of the tin wire feeding mechanism is detachably threaded with a head tube, the bottom end of the head tube is embedded with a ceramic tube for insulating the end portion of the tin bar, and the middle part of the tin wire feeding mechanism is internally rotated and assembled with a wire guide roller for guiding the transportation of the tin bar.

[0013] The rolling mechanism includes a tube shaft rotatably assembled inside the middle part of the tin bar wire feeding mechanism, the tube shaft is provided with two V-groove rolling wheels fixedly provided on the middle outer wall, the tin bar passes between the two V-groove rolling wheels, and the surface is rolled by the V-shaped protrusions on the inner wall of the edge groove of the V-groove rolling wheel, bearings are sleeved at both ends of the tube shaft, and a rubber sleeve is sleeved between the outer periphery of the bearing and the side wall of the tin bar wire feeding mechanism.

[0014] A through rod is installed movably through the axis of the tube shaft, and a vibrator is fixedly installed on the outer wall of the through rod and inside the V-groove rolling wheel. Roller bearings are installed at both ends of the through rod and inside the tube shaft.

[0015] The tin bar wire feeding mechanism is fixedly installed with a wall shell on the outer wall of the rolling mechanism corresponding to the tin bar wire feeding mechanism, and a motor 1 is fixedly installed inside the wall shell, and a gear 7 is fixedly installed on the output end of the motor 1, and the end of the tube shaft extending to the inside of the wall shell is fixedly installed with a gear 1, and the two gears 1 are meshed with each other, and the gear 7 is meshed with one of the gears 1, and a gear 2 meshing with the gear 1 is rotatably installed inside the wall shell, and one side of the two gears 2 are coaxially fixedly assembled with gear 3, and a gear 4 meshing with the gear 3 is rotatably installed inside the wall shell, and one side of the two gears 4 are coaxially fixedly assembled with gear 5, and the through rod passes through the tube shaft and extends to one end of the wall shell, and a gear 6 is fixedly installed, and the gear 6 is meshed with the corresponding gear 5.

[0016] The temperature control mechanism includes a fan arranged on one side of the top of the laser generator, and a main casing arranged on one side of the bottom of the laser generator. The air outlet of the fan is fixedly connected to an air duct, the end of the air duct is integrally connected to a branch pipe, and three branch pipes are arranged and distributed around the bottom of the laser generator at intervals. One end of the branch pipe is equipped with a valve, and the end of the branch pipe is connected to a hot air pipe in an array, and three hot air pipes are arranged at the end of each branch pipe.

[0017] A ball joint is fixedly provided at the end of each of the hot air pipes, and is movably connected to a nozzle through the ball joint. A rotating frame is fixedly installed on the outer wall of the end of the hot air pipe. A rotating arm is fixedly provided on the outer wall of the nozzle, and the rotating arm is rotatably connected to the rotating frame. An adjusting beam is integrally provided on the outer wall of the rotating arm at the junction with the rotating frame. Electric heating wires are installed inside the hot air pipes, and the number of electric heating wires inside the hot air pipes decreases one by one from the distance from the laser generator from near to far.

[0018] Auxiliary shells are fixedly arranged at the diagonal positions on both sides of the main shell, and the main shell and the two auxiliary shells are distributed around the bottom of the laser generator at intervals. Angle adjustment shafts are rotatably installed in the main shell and the auxiliary shells in an array, and two adjustment beams are integrally arranged at both ends of each of the angle adjustment shafts. Both ends of the adjustment beam one and the corresponding two ends of the adjustment beam two are connected through adjustment rods. The angle adjustment shafts with the same spacing size as the laser generator are connected through transmission shafts, and the angle adjustment shafts and the transmission shafts are connected through universal joints.

[0019] A gear eight is fixedly installed at one end of the angle adjustment shaft located inside the main housing, and the three gears eight inside the main housing are arranged in a staggered manner. A gear nine meshing with the gear eight is rotatably installed inside the main housing. A motor two is fixedly installed in a staggered manner inside the main housing, and the output end of the motor two is meshed and connected with the corresponding gear nine through a helical gear set.

[0020] A computer circuit board solder joint detection method, the specific steps are as follows:

[0021] S1: Collect solder joint images: Use industrial cameras such as CCD or 3D linear scan cameras to obtain raw image data of solder joints on the circuit board;

[0022] S2: Around-body shooting: By changing the shooting angle of the industrial camera or the angle of the circuit board, defects in the solder joints that cannot be identified when shooting vertically are obtained;

[0023] S3: Preprocessing the image: De-noising the collected solder joint image, using an adaptive median filter method to remove noise in the image while retaining edge information;

[0024] S4: feature extraction: extracting contour features and regional features from the preprocessed solder joint image;

[0025] S5: Feature reduction: Apply the knowledge reduction algorithm of rough set theory to simplify the extracted features and remove redundant information;

[0026] S6: Comparison detection: compare the simplified features with the qualified solder joint features stored in the feature database to determine whether the solder joint is qualified.

[0027] The technical effects achieved by the present invention are:

[0028] In the present invention, the ceramic tube located inside the end of the head pipe can prevent the heat inside the tin bar from being transferred to the head pipe, thereby achieving a temporary heat preservation effect. With the help of this heat preservation effect, the purpose of preheating the tin bar can be achieved at the same time, thereby alleviating the problem of heat energy transfer and dissipation inside the material, reducing heat loss, and optimizing the overall energy conversion efficiency.

[0029] The present invention utilizes the rolling process to cause continuous elastic-plastic deformation on the surface of the tin bar, thereby forming micro grooves. This rough surface can increase the light trapping effect, causing the light to be reflected and absorbed on the surface multiple times, thereby significantly improving the absorption rate. In addition, the high-speed rotating vibrator causes the V-groove rolling wheel to vibrate at the same time, thereby increasing the roughness of the tin bar surface and further optimizing the light energy absorption effect.

[0030] The present invention has three branch pipes distributed at intervals around the laser generator, which can control the temperature of the solder joints in the three directions of the welding moving paths, and the end of each branch pipe can spray out three hot air flows with different temperatures, so that the solder joints that have just been welded can be contacted with air flows with temperatures from high to low in sequence, thereby changing the instantaneous cooling of the solder joints of traditional circuit boards, avoiding problems such as porosity and embrittlement caused by rapid solidification of the solder joints, all of which will affect the strength and reliability of the welded joints. Finally, the direction of each air flow, that is, the angle of the nozzle can be adjusted according to the change of the position of the solder joint.

[0031] The present invention can avoid the problem of being unable to identify certain defects during vertical photography by photographing the welding sideways, thereby optimizing the accuracy of welding point detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a front view structural diagram of a soldering device provided by an embodiment of the present invention;

[0033] Figure 2 It is an assembly structure diagram of a laser generator, a tin wire feeding mechanism and a temperature control mechanism provided in an embodiment of the present invention;

[0034] Figure 3 is a partial cross-sectional view of a tin bar wire feeding mechanism provided by an embodiment of the present invention;

[0035] Figure 4 yes Figure 3 The local enlarged structure diagram at A in the middle;

[0036] Figure 5 yes Figure 3 The local enlarged structure diagram at B in the middle;

[0037] Figure 6 is a disassembled diagram of a tube shaft and a through rod provided in an embodiment of the present invention;

[0038] Figure 7 is a structural diagram of a temperature control mechanism provided by an embodiment of the present invention;

[0039] Figure 8 is a structural diagram of the temperature control mechanism provided by an embodiment of the present invention after removing the main housing and the auxiliary housing;

[0040] Fig. 9 yes Figure 8 The local enlarged structure diagram at C in the middle;

[0041] Fig.10 yes Figure 8 The local enlarged structure diagram at D in the middle;

[0042] Fig.11 is a cross-sectional structural diagram of a hot air duct provided by an embodiment of the present invention;

[0043] Fig.12 It is a schematic diagram of the welding spot detection and wraparound shooting provided by an embodiment of the present invention;

[0044] Fig.13 It is a flow chart of solder joint detection provided by an embodiment of the present invention.

[0045] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0046] 1. Machine; 2. Track 1; 3. Loading table; 4. Stand; 401. Track 2; 402. Slider; 403. Track 3; 5. Side frame; 6. Laser generator; 7. Tin bar wire feeding mechanism; 701. Head tube; 702. Wire guide roller; 703. Wall shell; 704. Tube shaft; 705. V-groove rolling wheel; 706. Bearing; 707. Rubber sleeve; 708. Gear 1; 709. Gear 2; 710. Gear 3; 711. Gear 4; 712. Gear 5; 713. Through rod; 714. Gear Six; 715, vibrator; 716, motor one; 717, gear seven; 718, ceramic tube; 8, temperature control mechanism; 801, fan; 802, air duct; 803, branch pipe; 804, valve; 805, hot air duct; 806, ball joint; 807, nozzle; 808, rotating frame; 809, rotating arm; 810, main housing; 811, auxiliary housing; 812, angle adjustment shaft; 813, adjustment rod; 814, transmission shaft; 815, gear eight; 816, gear nine; 817, motor two; 818, heating wire. DETAILED DESCRIPTION

[0047] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection of the specific claims of the present invention.

[0048] like Figure 1-Figure 11 As shown, a computer circuit board soldering equipment includes a machine table 1, a stand 4 is fixedly assembled on the surface of the machine table 1, and a track 2 401 is fixedly assembled on one side of the top of the stand 4, a slider 402 is slidably assembled on one side of the track 2 401 through a track machine, a track 3 403 is fixedly assembled on the outer side of the slider 402, a side frame 5 is slidably assembled on the outer side of the track 3 403 through a track machine, a laser generator 6 for generating laser is fixedly assembled below the side frame 5, a tin wire feeding mechanism 7 for conveying tin bars is fixedly assembled on the outer side of the side frame 5, a track 1 2 is fixedly installed on the surface of the machine table 1, and a loading platform 3 is slidably assembled on the surface of the track 1 2 through a track machine.

[0049] According to the above structure, the slider 402 slides along the track 2 401 to move the laser generator 6 laterally, the side frame 5 slides along the track 3 403 to move the laser generator 6 up and down, the stage 3 slides along the track 1 2 to move the stage 3 longitudinally, the tin bar wire feeding mechanism 7 is used to transport the tin bar, and the laser generator 6 heats the tin bar through laser to complete the work of welding the circuit board solder joints. The above processes are all existing technologies and will not be described in detail here.

[0050] Embodiment 1:

[0051] See attached Figure 3-Figure 6A rolling mechanism for changing the surface morphology of the tin bar is arranged inside the tin bar feeding mechanism 7. V-shaped micro grooves are prepared on the surface of the tin bar by the rolling mechanism, so that the laser light is reflected and absorbed multiple times on the surface.

[0052] See attached Figure 3 , Figure 5 The bottom end of the tin wire feeding mechanism 7 is detachably screwed with a head tube 701, and a ceramic tube 718 for insulating the end portion of the tin bar is embedded inside the bottom end of the head tube 701. The middle part of the tin wire feeding mechanism 7 is internally rotated and assembled with a guide wire roller 702 for guiding the transportation of the tin bar.

[0053] According to the above structure, the wire guide roller 702 is used to guide the transportation of the tin bar. When the laser generator 6 melts the end of the tin bar, part of the heat will be conducted along the tin bar, and the ceramic tube 718 located inside the end of the head tube 701 can prevent the internal heat of the tin bar from being conducted to the head tube 701, which plays a temporary heat preservation effect. With the help of this heat preservation effect, the purpose of preheating the tin bar can be achieved at the same time, alleviating the problem of heat transfer and dissipation inside the material, reducing heat loss, and optimizing the overall energy conversion efficiency.

[0054] See attached Figure 3-Figure 6 The rolling mechanism includes a tube shaft 704 which is rotatably assembled inside the middle part of the tin bar wire feeding mechanism 7. The tube shaft 704 is provided with two V-groove rolling wheels 705 which are fixedly provided on the middle outer wall. The tin bar passes through between the two V-groove rolling wheels 705 and is surface rolled by the V-shaped protrusions on the inner wall of the edge groove of the V-groove rolling wheel 705. Both ends of the tube shaft 704 are sleeved with bearings 706, and a rubber sleeve 707 is sleeved between the outer periphery of the bearing 706 and the side wall of the tin bar wire feeding mechanism 7.

[0055] See attached Figure 3-Figure 6 A through rod 713 is installed in a movable manner inside the axis of the tube shaft 704, and a vibrator 715 is fixedly installed on the outer wall of the through rod 713 and inside the V-groove rolling wheel 705. Roller bearings are installed at both ends of the through rod 713 and inside the tube shaft 704.

[0056] See attached Figure 3-Figure 6The outer wall of the tin bar wire feeding mechanism 7 corresponding to the rolling mechanism is fixedly installed with a wall shell 703, a motor 716 is fixedly installed inside the wall shell 703, and a gear 717 is fixedly installed at the output end of the motor 716, and a gear 708 is fixedly installed at one end of the pipe shaft 704 extending to the inside of the wall shell 703, and the two gears 708 are meshed with each other, and the gear 717 is meshed with one of the gears 708, and the wall shell 703 is rotatably installed with a gear 708. Gear two 709 is meshed with each other, and one side of the two gear twos 709 is coaxially fixedly assembled with gear three 710, the interior of the wall shell 703 is rotatably installed with gear four 711 meshing with gear three 710, and one side of the two gear fours 711 is coaxially fixedly assembled with gear five 712, the through rod 713 passes through the pipe shaft 704 and extends to one end of the interior of the wall shell 703, and gear six 714 is fixedly installed, and gear six 714 is meshed with the corresponding gear five 712.

[0057] According to the above structure, when the motor 1 716 is working, it drives the two tube shafts 704 to rotate in opposite directions at the same time through the meshing of the gear 717 with one of the gears 1 708 and the mutual meshing of the two gears 1 708. At this time, the two V-groove rolling wheels 705 will simultaneously roll the surface of the tin bar, and the surface of the tin bar will then form V-shaped micro grooves. At the same time, through the meshing of the gear 1 708 with the gear 2 709, the meshing of the gear 3 710 with the gear 4 711, and the meshing of the gear 5 712 with the gear 6 714, the penetrating rod 713 is finally driven to rotate at high speed inside the corresponding tube shaft 704. The eccentrically arranged vibrator 715 will produce a vibration effect under high-speed rotation. The vibration is transmitted to the V-groove rolling wheel 705 and directly acts on the surface of the tin bar, thereby improving the forming effect of the V-shaped micro-grooves on the surface of the tin bar. Through the above method, the rolling process is used to form continuous elastic-plastic deformation on the surface of the tin bar, thereby forming micro-grooves. This rough surface can increase the light trapping effect, causing the light to be reflected and absorbed on the surface multiple times, thereby significantly improving the absorption rate. In addition, the high-speed rotating vibrator 715 causes the V-groove rolling wheel 705 to have a vibration process at the same time, thereby increasing the roughness of the tin bar surface and further optimizing the absorption effect of light energy.

[0058] The working principle of the present invention is as follows: in the process of supplementing and transporting tin bars, the guide wire roller 702 is used to guide the transportation of the tin bars, and the motor 1 716 works at the same time, and through the meshing of the gear 717 with one of the gears 1 708, and the mutual meshing between the two gears 1 708, the two tube shafts 704 are driven to rotate in opposite directions at the same time. At this time, the two V-groove rolling wheels 705 will simultaneously roll the surface of the tin bar, and the surface of the tin bar will then form a V-shaped micro-groove. At the same time, through the meshing of the gear 1 708 with the gear 2 709, the meshing of the gear 3 710 with the gear 4 711, and the meshing of the gear 5 712 with the gear 6 714, the penetration rod 713 is finally driven to rotate at a high speed inside the corresponding tube shaft 704, and the eccentrically arranged vibrator 715 will produce a vibration effect under high-speed rotation. The vibration is transmitted to the V-groove rolling wheel 705 and directly acts on the surface of the tin bar, so as to improve the forming effect of the V-shaped micro-groove on the surface of the tin bar.

[0059] Embodiment 2:

[0060] See attached Figure 7-Figure 11 A temperature control mechanism 8 for controlling the cooling speed of the solder joint is provided from one side to the bottom of the laser generator 6. The temperature control mechanism 8 is used to change the instantaneous cooling of the solder joint to eliminate the residual stress in the soldering area.

[0061] See attached Figure 7-Figure 11 The temperature control mechanism 8 includes a fan 801 arranged on one side of the top of the laser generator 6, and a main housing 810 arranged on one side of the bottom of the laser generator 6. The air outlet of the fan 801 is fixedly connected with an air duct 802. The end of the air duct 802 is integrally connected with a branch pipe 803, and three branch pipes 803 are arranged and distributed around the bottom of the laser generator 6 at intervals of 90 degrees. One end of the branch pipe 803 is equipped with a valve 804. The end of the branch pipe 803 is connected with a hot air pipe 805 in an array manner, and three hot air pipes 805 are arranged at the end of each branch pipe 803.

[0062] See attached Figure 7-Figure 11 A ball joint 806 is fixedly provided at the end of each hot air pipe 805, and is movably connected to a nozzle 807 through the ball joint 806. A rotating frame 808 is fixedly installed on the outer wall of the end of the hot air pipe 805. A rotating arm 809 is fixedly provided on the outer wall of the nozzle 807, and the rotating arm 809 and the rotating frame 808 are rotatably connected. The outer wall of the rotating arm 809 at the junction with the rotating frame 808 is integrally provided with an adjusting beam 1. Electric heating wires 818 are installed inside the hot air pipe 805. The number of electric heating wires 818 inside the hot air pipe 805 decreases one by one from the distance from the laser generator 6 from near to far.

[0063] See attached Figure 7-Figure 11Auxiliary shells 811 are fixedly arranged at the diagonal positions on both sides of the main shell 810. The main shell 810 and the two auxiliary shells 811 are distributed around the bottom of the laser generator 6 at an interval of 90 degrees. The main shell 810 and the auxiliary shells 811 are both internally installed with angle adjustment shafts 812 in an array-like manner. Both ends of each angle adjustment shaft 812 are integrally provided with an adjustment beam 2. Both ends of the adjustment beam 1 are connected to the corresponding ends of the adjustment beam 2 through an adjustment rod 813. The angle adjustment shafts 812 with the same spacing size as the laser generator 6 are connected through a transmission shaft 814, and the angle adjustment shaft 812 and the transmission shaft 814 are connected through a universal joint.

[0064] See attached Figure 7-Figure 11 A gear eight 815 is fixedly installed at one end of the angle adjustment shaft 812 located inside the main housing 810, and the three gear eights 815 inside the main housing 810 are arranged in a staggered manner. A gear nine 816 meshing with the gear eight 815 is rotatably installed inside the main housing 810. Motor two 817 is fixedly installed in a staggered manner inside the main housing 810, and the output end of the motor two 817 is meshed and connected with the corresponding gear nine 816 through a helical gear set.

[0065] According to the above structure, during the soldering process of the circuit board, according to the moving direction of the laser generator 6, the valve 804 at the corresponding position is opened, for example, Figure 8 As shown, assuming that the laser generator 6 moves from the left to the right in the figure and welds, it is only necessary to open the leftmost valve 804 in the figure, and the fan 801 will start and inject air into the corresponding branch pipe 803, and the air will then be evenly injected into the three hot air pipes 805 at the end thereof, where the electric heating wires 818 in the three hot air pipes 805 are all energized to heat the airflow to be blown out, as shown in the attached figure. Fig.11As shown, the closer the hot air pipe 805 is to the laser generator 6, the higher the temperature of the air flow it blows out will be. Therefore, when a certain welding point has just been welded, it will be temperature-controlled and baked by hot air flows of different temperatures in sequence, and the temperature will be gradually reduced. In addition, according to the position of the welding point, the angle of the nozzle 807 at the corresponding position can also be adjusted. The adjustment process is as follows: start the motor 2 817 at the corresponding position, and it drives the corresponding angle adjustment shaft 812 in the main housing 810 to rotate through the bevel gear set and the engagement of the gear 815 and the gear 9 816. At the same time, it drives the corresponding angle adjustment shaft 812 in the auxiliary housing 811 to rotate together through the transmission shaft 814. After the angle adjustment shaft 812 rotates, the corresponding angle adjustment shaft 812 is driven by the adjustment rod 813. The nozzle 807 rotates to achieve the effect of adjusting the angle of the nozzle 807 following the change of the solder joint position; in the above process, the three branch pipes 803 distributed around the laser generator 6 at an interval of 90 degrees can control the temperature of the solder joint in the three directions of the welding movement path, and each branch pipe 803 can spray out three hot air flows with different temperatures at the end, so that the solder joints that have just been welded can be contacted with air flows with temperatures from high to low in sequence, thereby changing the instantaneous cooling of the solder joints of traditional circuit boards, avoiding problems such as porosity and embrittlement caused by rapid solidification of the solder joints, which will affect the strength and reliability of the welded joints. Finally, the direction of each air flow, that is, the angle of the nozzle 807, can be adjusted according to the change of the solder joint position.

[0066] The working principle of the present invention is: during the soldering process of the circuit board, according to the moving direction of the laser generator 6, the valve 804 at the corresponding position is opened, for example, Figure 8 As shown, assuming that the laser generator 6 moves from the left to the right in the figure and welds, it is only necessary to open the leftmost valve 804 in the figure, and the fan 801 will start and inject air into the corresponding branch pipe 803, and the air will then be evenly injected into the three hot air pipes 805 at the end thereof, where the electric heating wires 818 in the three hot air pipes 805 are all energized to heat the airflow to be blown out, as shown in the attached figure. Fig.11As shown, the closer the hot air pipe 805 is to the laser generator 6, the higher the temperature of the air flow it blows out will be. Therefore, when a certain welding point has just been welded, it will be temperature-controlled and baked by hot air flows of different temperatures in sequence, and the temperature will decrease gradually. In addition, according to the position of the welding point, the angle of the nozzle 807 at the corresponding position can also be adjusted. The adjustment process is as follows: start the motor 2 817 at the corresponding position, and it drives the corresponding angle adjustment shaft 812 in the main housing 810 to rotate through the bevel gear set and the engagement of gear eight 815 and gear nine 816. At the same time, it drives the corresponding angle adjustment shaft 812 in the auxiliary housing 811 to rotate together through the transmission shaft 814. After the angle adjustment shaft 812 rotates, the corresponding nozzle 807 is rotated with the help of the adjustment rod 813, so as to achieve the effect of adjusting the angle of the nozzle 807 to follow the change of the welding point position.

[0067] like Figure 12-13 As shown, a method for detecting solder joints on a computer circuit board, the specific steps are as follows:

[0068] S1: Collect solder joint images: Use industrial cameras such as CCD or 3D linear scan cameras to obtain raw image data of solder joints on the circuit board;

[0069] S2: Around-body shooting: By changing the shooting angle of the industrial camera or the angle of the circuit board, defects in the solder joints that cannot be identified when shooting vertically are obtained;

[0070] S3: Preprocessing the image: De-noising the collected solder joint image, using an adaptive median filter method to remove noise in the image while retaining edge information;

[0071] S4: feature extraction: extracting contour features and regional features from the preprocessed solder joint image;

[0072] S5: Feature reduction: Apply the knowledge reduction algorithm of rough set theory to simplify the extracted features and remove redundant information;

[0073] S6: Comparison detection: compare the simplified features with the qualified solder joint features stored in the feature database to determine whether the solder joint is qualified.

[0074] The working principle of the present invention is as follows: Fig.12 As shown, by photographing the weld sideways, the problem of not being able to identify certain defects when photographing vertically can be avoided, thereby optimizing the accuracy of weld spot inspection.

[0075] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A computer circuit board soldering device, comprising a machine table (1), a stand (4) fixedly assembled on the surface of the machine table (1), and a track 2 (401) fixedly assembled on one side of the top of the stand (4), a slider (402) slidably assembled on one side of the track 2 (401) through a track machine, a track 3 (403) fixedly assembled on the outer side of the slider (402), a side frame (5) slidably assembled on the outer side of the track 3 (403) through a track machine, a laser generator (6) for generating laser light fixedly assembled below the side frame (5), and a tin wire feeding mechanism (7) for conveying tin bars fixedly assembled on the outer side of the side frame (5), characterized in that: A rolling mechanism for changing the surface morphology of the tin bar is arranged inside the tin bar wire feeding mechanism (7), and a temperature control mechanism (8) for controlling the cooling speed of the soldering point is arranged from one side to the bottom of the laser generator (6); The bottom end of the tin bar wire feeding mechanism (7) is detachably threaded with a head tube (701), a ceramic tube (718) for heat-insulating the end portion of the tin bar is embedded inside the bottom end of the head tube (701), and a guide wire roller (702) for guiding the transportation of the tin bar is rotatably assembled inside the middle part of the tin bar wire feeding mechanism (7); The rolling mechanism comprises a tube shaft (704) rotatably assembled inside the middle of the tin bar wire feeding mechanism (7), the tube shaft (704) being provided with two V-groove rolling wheels (705) fixedly provided on the outer wall of the middle part, the tin bar passes between the two V-groove rolling wheels (705), and the surface is rolled by the V-shaped protrusions on the inner wall of the edge groove of the V-groove rolling wheel (705), both ends of the tube shaft (704) are sleeved with bearings (706), and a rubber sleeve (707) is sleeved between the outer periphery of the bearing (706) and the side wall of the tin bar wire feeding mechanism (7); V-shaped micro grooves are prepared on the surface of the tin bar by a rolling mechanism, so that the laser light is reflected and absorbed multiple times on the surface; The temperature control mechanism (8) is used to change the instantaneous temperature drop of the welding point to eliminate the residual stress in the welding area.

2. A computer circuit board soldering device according to claim 1, characterized in that: A track 1 (2) is fixedly mounted on the surface of the machine platform (1), and a loading platform (3) is slidably assembled on the surface of the track 1 (2) via a track machine.

3. A computer circuit board soldering device according to claim 1, characterized in that: A through rod (713) is movably installed inside the axis of the tube shaft (704), and a vibrator (715) is fixedly installed on the outer wall of the through rod (713) and located inside the V-groove rolling wheel (705). Roller bearings are installed at both ends of the through rod (713) and located inside the tube shaft (704).

4. A computer circuit board soldering device according to claim 3, characterized in that: The tin wire feeding mechanism (7) is fixedly mounted with a wall shell (703) on the outer wall of the rolling mechanism, and a motor (716) is fixedly mounted inside the wall shell (703), and a gear (717) is fixedly mounted on the output end of the motor (716). The end of the tube shaft (704) extending into the wall shell (703) is fixedly mounted with a gear (708), and the two gears (708) are meshed with each other, and the gear (717) is meshed with one of the gears (708). The wall shell (703) is rotatably mounted with a gear (717) that is engaged with the gear (717). 08) meshing gear two (709), and one side of the two gear twos (709) is coaxially fixedly assembled with gear three (710), the interior of the wall shell (703) is rotatably mounted with gear four (711) meshing with gear three (710), and one side of the two gear fours (711) is coaxially fixedly assembled with gear five (712), the through rod (713) passes through the pipe shaft (704) and extends to one end of the wall shell (703) inside, and gear six (714) is fixedly mounted, and gear six (714) is meshing with the corresponding gear five (712).

5. The computer circuit board soldering equipment according to claim 1, characterized in that: The temperature control mechanism (8) comprises a fan (801) arranged on one side of the top of the laser generator (6), and a main housing (810) arranged on one side of the bottom of the laser generator (6); an air outlet of the fan (801) is fixedly connected to an air duct (802); an end of the air duct (802) is integrally connected to a branch pipe (803); three branch pipes (803) are arranged and distributed around the bottom of the laser generator (6) at intervals of 90 degrees; one end of each branch pipe (803) is equipped with a valve (804); the ends of the branch pipes (803) are connected to hot air pipes (805) in an array manner; and three hot air pipes (805) are arranged at the end of each branch pipe (803).

6. A computer circuit board soldering device according to claim 5, characterized in that: A ball joint (806) is fixedly provided at the end of each of the hot air pipes (805), and is movably connected to a nozzle (807) via the ball joint (806); a rotating frame (808) is fixedly installed on the outer wall of the end of the hot air pipe (805); a rotating arm (809) is fixedly provided on the outer wall of the nozzle (807), and the rotating arm (809) and the rotating frame (808) are rotatably connected; an adjustment beam 1 is integrally provided on the outer wall of the rotating arm (809) at the junction with the rotating frame (808); electric heating wires (818) are installed inside the hot air pipes (805), and the number of electric heating wires (818) inside the hot air pipes (805) decreases one by one as the distance from the laser generator (6) increases from near to far.

7. A computer circuit board soldering device according to claim 6, characterized in that: Auxiliary shells (811) are fixedly arranged at diagonally opposite corners of both sides of the main shell (810); the main shell (810) and the two auxiliary shells (811) are distributed around the bottom of the laser generator (6) at an interval of 90 degrees; angle adjustment shafts (812) are rotatably installed in an array inside the main shell (810) and the auxiliary shells (811); two adjustment beams (812) are integrally arranged at both ends of each of the angle adjustment shafts (812); the two ends of the first adjustment beam and the two ends of the corresponding second adjustment beam are connected via adjustment rods (813); the angle adjustment shafts (812) having the same spacing size as the laser generator (6) are connected via transmission shafts (814); and the angle adjustment shafts (812) and the transmission shafts (814) are connected via universal joints; One end of the angle adjustment shaft (812) located inside the main housing (810) is fixedly mounted with a gear eight (815), and the three gear eights (815) inside the main housing (810) are arranged in a staggered manner. A gear nine (816) meshing with the gear eight (815) is rotatably mounted inside the main housing (810), and a motor two (817) is fixedly mounted in a staggered manner inside the main housing (810), and the output end of the motor two (817) is meshed and transmission-connected with the corresponding gear nine (816) via a helical gear set.

8. A method for detecting solder joints on a computer circuit board, using the computer circuit board soldering equipment according to any one of claims 1 to 7, characterized in that: The specific steps are as follows: S1: Collect solder joint images: Use an industrial camera to obtain the original image data of the solder joints on the circuit board; S2: Around-body shooting: By changing the shooting angle of the industrial camera or the angle of the circuit board, defects in the solder joints that cannot be identified when shooting vertically are obtained; S3: Preprocessing the image: De-noising the collected solder joint image, using an adaptive median filter method to remove noise in the image while retaining edge information; S4: feature extraction: extracting contour features and regional features from the preprocessed solder joint image; S5: Feature reduction: Apply the knowledge reduction algorithm of rough set theory to simplify the extracted features and remove redundant information; S6: Comparison detection: compare the simplified features with the qualified solder joint features stored in the feature database to determine whether the solder joint is qualified.

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