A laser ball planting method and system for a stator component

Abstract

The application relates to the technical field of welding, in particular to a laser ball planting method and system for a stator component, which method comprises the following steps: firstly, obtaining model parameters and pad distribution information of the stator component; after axial positioning by a jig, the stator component is sequentially transferred to a laser peeling station, a flux applying station and a laser ball planting station by a four-station turntable, and corresponding processing is completed; before ball planting, actual position and height data of the pads are obtained by a visual positioning assembly, parameters of an XYZ-axis servo lead screw module are adjusted, tin balls are sprayed by a laser ball planting assembly and then melted and welded, and finally, the stator component is discharged by a mechanical hand and enters the next cycle. The application helps to improve the precision, efficiency and reliability of ball planting welding of the motor stator component.

Description

Technical Field

[0001] This application relates to the field of welding technology, and in particular to a laser ball-planting method and system for stator components. Background Technology

[0002] In the field of motor manufacturing, the stator component, as a core part of the motor, directly affects the electrical performance, reliability, and service life of the motor due to the welding quality between its copper wire leads and solder pads. As motors develop towards miniaturization, high efficiency, and high power density, the size of stator solder pads is continuously decreasing, placing higher demands on the precision, consistency, and stability of ball-mounting soldering. Traditional stator ball-mounting processes often employ manual or semi-automatic methods, including manual peeling, manual dispensing, and mechanical ball placement. This is not only inefficient and labor-intensive but also prone to problems such as insufficient pad cleanliness, uneven flux application, and solder ball positioning deviations due to human error, thus affecting the welding quality. Furthermore, stator components inevitably have certain dimensional and positional errors during processing and assembly, which traditional equipment struggles to compensate for in real time, making it difficult to guarantee ball-mounting accuracy. Therefore, how to improve the automation, positioning accuracy, and production efficiency of stator ball-mounting soldering while ensuring welding quality has become a pressing technical problem for the motor manufacturing industry. Summary of the Invention

[0003] To help improve the accuracy, efficiency and reliability of ball-mounting welding for motor stator components, this application provides a laser ball-mounting method and system for stator components.

[0004] Firstly, this application provides a laser ball-planting method for stator components, which adopts the following technical solution: A laser ball-mounting method for stator components, comprising: Obtain the model parameters and pad distribution information of the stator components; The stator component is placed on the fixture platform, and the stator component is axially positioned by the fixture jaws; Start the four-station turntable to transfer the stator components to the laser peeling station; Based on the stator component pad distribution information, the power and position of the laser peeling component are adjusted to perform laser peeling on the pads corresponding to the three copper wire pins. After peeling, the turntable transports the stator component to the flux application station, where flux is precisely sprayed onto the three solder pads via a flux piezoelectric valve. The stator components are transferred to the laser ball-mounting station, and the actual position and height data of the pads are obtained through a vision positioning component. Adjust the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads; Solder balls are sprayed onto the pads using a laser ball-mounting assembly, while the laser is activated to melt the solder balls, thus completing the ball-mounting soldering process. After the ball planting is completed, the turntable will transfer the stator components back to the loading position, where the robotic arm will unload them and begin the next product cycle.

[0005] Optionally, the step of adjusting the power and position of the laser peeling component based on the stator component pad distribution information to perform laser peeling on the pads corresponding to the three copper wire leads includes: Based on the model parameters of the stator component, retrieve the preset standard position coordinates of the solder pads and the tare power range; By using the rotation function of the fixture stage, the first pad is aligned with the laser peeling component; Based on the stator component pad distribution information, the vision positioning component is activated to detect the position of the first pad and obtain the position deviation value. Adjust the X and Y axis servo screw modules according to the position deviation value so that the laser focus is aligned with the center of the solder pad; Based on the thickness of the solder pad oxide layer, the target peeling power is determined within the peeling power range; The laser is turned on to perform laser peeling on the first pad, while the dust generated by the peeling is removed by the dust extraction component. After peeling is completed, the fixture stage is rotated by a preset angle, and the above peeling operation is repeated for the other two pads in turn; After each pad is peeled, the vision positioning component checks the surface condition of the pad again to confirm that the peeling meets the standard.

[0006] Optionally, the transfer of the stator component to the laser ball-mounting station, and the acquisition of the actual position and height data of the pads through a vision positioning component, includes: After the turntable transfers the stator components to the laser ball-planting station, the ball-planting positioning ring light source is activated to illuminate the pad area. The visual positioning camera is controlled to take pictures of the three pads simultaneously to obtain pad images; Image processing algorithms are used to process the pad images and extract the edge features of each pad. The center coordinates of the corresponding pads are fitted based on the edge features of each pad, and the center coordinates of the three pads are used as the actual positions of each pad. Start the height sensor and, according to the pad numbering order, sequentially sample the height data of a single pad surface at multiple points along the vertical direction corresponding to the center coordinate of each pad. Based on multi-point sampling data, the average height is calculated and used as the height data for each pad.

[0007] Optionally, adjusting the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads includes: Based on the actual position and height data of the pads, analyze the lateral position deviation, longitudinal position deviation, and height deviation; Based on the lateral position deviation, the X-axis servo screw module is driven to perform translation adjustment, with the adjustment accuracy controlled within ±0.05mm; Based on the longitudinal position deviation, the Y-axis servo screw module is driven to perform translational adjustment to ensure that the laser ball-planting assembly is aligned with the center of the pad. Based on the height deviation, adjust the lifting height of the Z-axis servo screw module to maintain a preset distance between the ball-planting nozzle and the pad surface; When both the position deviation and height deviation are less than the allowable threshold, stop the module adjustment and lock the position parameters. If the number of adjustments exceeds the upper limit for the first adjustment and the target is still not met, the nozzle calibration component will be activated to calibrate the ball-planting nozzle. After calibration, the pad positioning test and module adjustment were performed again.

[0008] Optionally, the step of spraying solder balls onto the pads using a laser ball-mounting assembly, while simultaneously activating the laser to melt the solder balls and complete the ball-mounting soldering, includes: Turn on the nitrogen gas source and adjust the gas pressure to 0.2-0.4MPa through the nitrogen pressure regulating valve. The nitrogen gas is then purified by the filter and introduced into the gas line. After receiving the ventilation signal, the solenoid valve is turned on, and nitrogen flows into the electro-proportional valve for secondary pressure regulation, outputting a constant low-pressure airflow. A low-pressure airflow pushes 850-1000μm solder balls from the ball storage chamber to the ball planting nozzle. The solder balls block the nozzle orifice, causing the air pressure in the nozzle chamber to rise. After the differential pressure sensor detects that the air pressure has risen to a preset value, it sends a ball signal to the control system. After receiving the ball signal, the control system controls the laser to prepare to emit light and adjusts the light emission duration to the preset duration. The laser emitted by the laser is focused by the collimating lens and the focusing lens, and then shines on the solder ball in the nozzle through the laser through-hole; After the solder balls melt, they are ejected from the nozzle under air pressure, fall onto the surface of the solder pads, and complete the solder ball placement.

[0009] Optionally, after the solder balls melt, they are ejected from the nozzle under air pressure, fall onto the surface of the solder pads, and complete the solder ball placement process, including: The visual positioning component switches to solder joint detection mode to acquire images of the solder joints that have just been welded. Based on the pad edge features and the actual position of the pad, the solder joints are analyzed and the analysis results are obtained; Based on the analysis results, determine whether there are any target defects; If a target defect exists, record the defect type and the corresponding pad location; The laser power and emission time are automatically adjusted and the repair welding program is started to repair the weld points with target defects and re-inspect them; If the target defect still exists after the second welding repair count reaches the upper limit, the corresponding stator component will be marked as a defective product, an alarm signal will be sent, and the material unloading and diversion will be triggered. After the solder joints pass inspection, the inspection data and solder joint images are stored. The fixture platform rotates to a preset angle to perform ball bonding and inspection processes on the next pad.

[0010] Optionally, the automatic adjustment of laser power and emission duration and the initiation of the repair welding procedure include: Obtain the defect type and defect severity parameters of the unqualified solder joints. Defect types include cold solder joints, insufficient solder, and solder ball misalignment. A library of repair welding strategies based on defect type matching; Retrieve the standard welding parameters corresponding to the stator component model, and calculate the laser power adjustment range and the correction value of the light output time based on the defect degree parameters; Adjust the XYZ axis servo lead screw module so that the ball-planting nozzle is re-aligned with the center of the defective weld point; Turn on the nitrogen protection gas circuit and fine-tune the gas pressure to 0.05 MPa higher than the original welding gas pressure; The repair welding was started according to the adjusted parameters. During the repair welding process, the visual positioning component collected images of the melting state of the weld point in real time. The image algorithm monitors the molten solder spreading range and solidification trend, and stops the soldering repair if the preset standard is reached. After the welding repair is completed, the height sensor checks the height of the weld point again and compares it with the standard height range to confirm that the welding repair meets the standard.

[0011] Optionally, after the defect type-based matching corresponding repair welding strategy library, the following is also included: If the defect type is solder ball adhesion and the adhesion range exceeds 1.5 times the diameter of a single pad, a special separation procedure will be initiated. Control the Z-axis servo screw module to raise the ball-planting nozzle to the preset safe height, switch the nitrogen gas path to high-pressure mode, and adjust the gas pressure to 0.3-0.35MPa; High-pressure nitrogen gas is sprayed into the adhesion area through the nozzle, and the spraying is stopped after a preset time. The visual positioning component captures images of the adhered area to determine whether the solder balls have separated. If separation fails, adjust the laser power to 80% of the original power, turn on the laser for local heating, and simultaneously purge with low-pressure nitrogen gas. The separation status was confirmed again by visual inspection. After successful separation, the original welding parameters were restored for repair welding. If the separation count still fails to meet the standard after reaching the third threshold, the corresponding stator component is recorded as a seriously defective product, and an alarm signal is sent.

[0012] Secondly, this application also discloses a laser ball-planting system for stator components, which adopts the following technical solution: A laser ball-mounting system for stator components, comprising: The parameter acquisition module is used to acquire the model parameters and pad distribution information of the stator components; The positioning module is used to place the stator component on the fixture platform and to perform axial positioning of the stator component by means of the fixture jaws; The transfer module is used to activate the four-station turntable and transfer the stator components to the laser peeling station; The laser peeling module is used to adjust the power and position of the laser peeling component based on the pad distribution information of the stator component, and to perform laser peeling on the pads corresponding to the three copper wire pins. The flux spraying module is used to transfer the stator component to the flux station after peeling, and precisely spray flux onto the three pads through the flux piezoelectric valve. The data acquisition module is used to transfer stator components to the laser ball-mounting station and acquire the actual position and height data of the pads through the vision positioning component; The parameter adjustment module is used to adjust the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads. The ball-mounting and soldering module is used to spray solder balls onto the pads via a laser ball-mounting component, while simultaneously turning on the laser to melt the solder balls, thus completing the ball-mounting and soldering process. The unloading module is used to transfer the stator components back to the loading position by the turntable after the ball planting is completed, and the unloading operation is performed by the robot arm to enter the next product cycle.

[0013] In summary, this application includes the following beneficial technical effects: By integrating laser peeling, flux application, laser ball placement, and loading / unloading processes into a four-station turntable, the automation level and production efficiency of stator component ball placement welding are significantly improved. A vision positioning component acquires the actual position and height data of the solder pads, and real-time compensation and adjustment are performed via an XYZ axis servo screw module. This effectively eliminates the impact of stator component processing and clamping errors on welding accuracy. Combined with the synergistic effect of laser peeling and laser ball melting processes, this not only ensures the cleanliness of the solder pad surface and the quality of the welding interface but also improves the positioning accuracy and consistency of solder ball welding, thereby contributing to improved accuracy, efficiency, and reliability of motor stator component ball placement welding. Attached Figure Description

[0014] Figure 1 This is a main flowchart of a laser ball-planting method for stator components according to an embodiment of this application; Figure 2 This is a flowchart of the steps for laser peeling of the pads corresponding to the three copper wire pins. Figure 3 This is a flowchart illustrating the steps involved in obtaining the actual position and height data of the pads using a visual positioning component. Figure 4 This is a flowchart showing the steps for adjusting the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads. Figure 5 The flowchart shows the steps of solder ball placement: a laser ball placement component sprays solder balls onto the pads, and the laser is turned on to melt the solder balls. Figure 6 This is a block diagram of a laser ball-planting system for stator components according to an embodiment of this application.

[0015] Explanation of reference numerals in the attached figures: 1. Parameter acquisition module; 2. Positioning module; 3. Transfer module; 4. Laser peeling module; 5. Flux spraying module; 6. Data acquisition module; 7. Parameter adjustment module; 8. Ball welding module; 9. Material unloading module. Detailed Implementation

[0016] In a first aspect, this application discloses a laser ball-planting method for stator components.

[0017] Reference Figure 1 A laser ball-mounting method for stator components includes steps S101 to S109: Step S101: Obtain the model parameters and pad distribution information of the stator component.

[0018] Specifically, the stator component model parameters include key information such as the stator's dimensions, material type, number of pads, and spacing; the pad distribution information includes the relative position coordinates and arrangement of the three pads on the stator component, corresponding to the installation positions of the three copper wire pins on the stator component. This information can be obtained through barcode scanning or system preset selection. After input, it is transmitted to the equipment's main control system, providing fundamental data support for the subsequent precise transfer of the four-station turntable, laser peeling, and ball bonding parameter matching.

[0019] Step S102: Place the stator component on the fixture platform and position the stator component axially using the fixture jaws.

[0020] Specifically, the fixture platform is a dedicated support platform adapted to the shape of the stator component. The fixture platform measures 300*250mm and features rotation, positioning, and locking functions. It works in conjunction with the hollow rotating platform and positioning blocks in the product tooling assembly. The fixture grippers are pneumatic elastic grippers whose clamping force can be adjusted according to the material of the stator component to avoid damage. They are connected to a compressed air circuit, providing power through compressed air. After the operator or robot places the stator component at the preset station on the fixture platform, the control system issues a command, and the fixture grippers clamp along the axial direction of the stator component, achieving axial positioning. This ensures that the stator component will not undergo axial displacement during subsequent four-station turntable transfer and processing, guaranteeing machining accuracy.

[0021] Step S103: Start the four-station turntable and transfer the stator component to the laser peeling station.

[0022] Specifically, the four-station turntable is the core transfer mechanism of the equipment, driven by a DD motor. Four fixture mounting positions are evenly distributed around its circumference, corresponding to the four core stations: material loading, laser peeling, flux application, and laser ball placement. Positioning accuracy reaches ±0.02mm, ensuring precise switching between stations. After startup, the turntable rotates at a preset angle, accurately transferring the axially positioned stator component to the designated processing position in the laser peeling station. The component is then locked in place by the turntable's positioning pins, providing a stable processing environment for the precise operation of the laser peeling assembly.

[0023] Step S104: Based on the stator component pad distribution information, adjust the power and position of the laser peeling component to perform laser peeling on the pads corresponding to the three copper wire leads.

[0024] Specifically, the laser peeling component is one of the core components of the equipment's functional execution system. It includes a 5W laser, a laser transmission optical path, and a focusing lens, used to emit a laser of a specific wavelength to remove the oxide layer on the surface of the solder pads. The copper wire leads are copper pins on the stator components used for conductive connections, and their corresponding solder pads are the soldering areas where the pins connect to external circuits. The surface of these pads is prone to oxide layer formation, affecting soldering quality. Based on the acquired solder pad distribution information, the control system first adjusts the spatial position of the laser peeling component through the X and Y axis servo screw modules (servo screw module repeatability ±0.05mm) to align it with the solder pad area. Then, the laser power is adjusted according to the solder pad material and the estimated oxide layer thickness to ensure accurate removal of the oxide layer without damaging the solder pad substrate. Simultaneously, the dust extraction system connected to the dust extraction port removes processing dust, maintaining a clean processing environment.

[0025] Step S105: After peeling, the turntable transfers the stator component to the flux application station, and the flux is precisely sprayed onto the three solder pads through the flux piezoelectric valve.

[0026] Specifically, the flux piezoelectric valve is a high-precision spraying component and a core part of the flux application assembly. It works in conjunction with the flux cylinder, flux piezoelectric valve regulator, and flux piezoelectric valve controller. Through the high-frequency vibration of the piezoelectric crystal, it achieves micro-volume, precise flux spraying. The spraying volume can be precisely adjusted by the control system based on the stator component model parameters. The flux is a no-clean soldering auxiliary material that removes residual oxide layers from the solder pad surface, reduces soldering temperature, and improves the adhesion between the solder balls and the solder pads. According to production process requirements, after the turntable transports and positions the stator component to the flux application station, the flux piezoelectric valve moves directly above each solder pad. Powered by compressed air (compressed air pressure 0.4-0.7 MPa), it evenly sprays flux onto the solder pad surface according to the preset spray volume, preparing for subsequent laser ball bonding.

[0027] Step S106: Transfer the stator component to the laser ball-mounting station and obtain the actual position and height data of the pads through the vision positioning component.

[0028] Specifically, the laser ball placement station is the core station for completing solder ball spraying and welding. It integrates ball placement components, a 200W laser component, and a positioning component, meeting the stator ball placement laser power requirements in the equipment's technical parameters. The vision positioning component includes a 6-megapixel ball placement positioning camera, a ball placement positioning ring light source, and an image processor. It is a key part of the equipment's functional execution system. The ring light source is used to illuminate the pad area to improve image clarity. After the industrial camera captures the pad image, the image processor extracts the pad features through image algorithms, and then calculates the actual position coordinates and surface height data of the pad. The height sensor simultaneously collects height information (height sensor measurement accuracy ±0.001mm) to compensate for previous positioning errors and provide data support for accurate ball placement.

[0029] Step S107: Based on the actual position and height data of the pads, adjust the position parameters of the XYZ axis servo screw module.

[0030] Specifically, the XYZ axis servo lead screw module is the core of the equipment's drive and positioning system. It consists of a servo motor, a precision lead screw, and guide rails, and features high-precision position adjustment. The X, Y, and Z axis movement speed ranges from 0.1 to 500 mm / s, with a repeatability of ±0.05 mm. After receiving the actual position and height data of the solder pads, the control system compares it with preset standard positions and heights, calculates the positional deviations in the X and Y axes and the height deviation in the Z axis, and then drives the XYZ axis servo lead screw module to make targeted adjustments. This ensures that the nozzle of the laser ball-planting assembly is aligned with the center of the solder pad and at the optimal ball-planting height, guaranteeing that the ball-planting accuracy meets the requirements.

[0031] Step S108: Spray solder balls onto the pads using the laser ball-mounting assembly, and simultaneously turn on the laser to melt the solder balls, thus completing the ball-mounting soldering.

[0032] Specifically, the laser ball-planting assembly is the core component of the equipment's functional execution system, including components such as a solder ball tank, a ball storage bin, a solder ball separating assembly, a ball-planting nozzle, a collimating lens, and a focusing lens, which are compatible with solder balls of 850-1000μm size; the laser is a 200W pulsed laser, whose output laser power, pulse frequency, and light emission duration can be precisely adjusted through the software system. After adjustment, based on the nitrogen gas path principle for ball placement, the nitrogen source is purified by a nitrogen filter, regulated by a nitrogen pressure regulating valve (0.2-0.4MPa) in the first stage, controlled by a solenoid valve on / off, and regulated by an electro-proportional valve in the second stage to form a constant low-pressure airflow. This airflow pushes the solder balls from the ball storage chamber to the ball placement nozzle. The solder balls block the nozzle orifice, causing the air pressure in the nozzle chamber to rise. After the differential pressure sensor detects the preset air pressure value, it sends a ball presence signal to the control system. The system controls the laser to emit light. The laser is focused by a collimating lens and a focusing lens and then shines on the solder balls through the laser through-hole, causing the solder balls to melt rapidly. The molten solder is tightly bonded to the solder pads under the action of flux. After cooling, it forms a stable solder joint, completing the ball placement welding.

[0033] Step S109: After the ball planting is completed, the turntable will transfer the stator component back to the loading position, and the robot will unload it to enter the next product cycle.

[0034] Specifically, the robotic arm is an external actuator that works in conjunction with the automated production of the equipment. After the ball is placed, the four-station turntable rotates to transfer the stator component back to the initial loading position. The control system issues a loading command, and the robotic arm precisely grabs or adsorbs the stator component and transfers it to the qualified product conveyor line or designated area. Then the fixture platform is reset, waiting for the next stator component to be loaded, and a new product processing cycle begins, realizing an automated closed-loop process.

[0035] Reference Figure 2 In one embodiment of this example, step S104, based on the stator component pad distribution information, adjusts the power and position of the laser peeling component to perform laser peeling on the pads corresponding to the three copper wire leads, including steps S201 to S208: Step S201: Based on the model parameters of the stator component, retrieve the preset standard position coordinates of the solder pads and the tare power range.

[0036] Specifically, the equipment control system pre-stores a database of standard position coordinates for solder pads corresponding to different stator component models. These coordinates are precisely set based on the stator component design drawings and match the positioning reference of the fixture platform. The peeling power range is a laser power range determined based on the characteristics of solder pads made of different materials (such as copper solder pads) and the parameter range of the equipment's 5W laser peeler, ensuring that the oxide layer can be effectively removed within this range without damaging the solder pads. After obtaining the stator component model parameters, the control system automatically matches and retrieves the corresponding standard position coordinates of the solder pads and the peeling power range as a reference for subsequent adjustments, ensuring compatibility with the equipment hardware parameters.

[0037] Step S202: By using the rotation function of the fixture stage, the first pad is aligned with the laser peeling component.

[0038] Specifically, the fixture stage is equipped with a hollow rotating platform driven by a rotary servo motor, which is the core component of the product tooling stage assembly. It can achieve 360° precise rotation with a rotation angle accuracy of ±0.01°. Based on the retrieved standard position coordinates of the first solder pad, the control system drives the fixture stage to rotate by the corresponding angle, ensuring that the central axis of the first solder pad is coaxial with the laser optical path of the laser peeling component. This ensures that the first solder pad is directly facing the laser peeling component, laying the foundation for subsequent precise positioning and peeling operations.

[0039] Step S203: Based on the stator component pad distribution information, start the vision positioning component to perform position detection on the first pad and obtain the position deviation value.

[0040] Specifically, the vision positioning component switches to peel positioning mode. Its 6-megapixel ball-mounting positioning camera is aimed at the first pad area, capturing a clear image of the pad with the assistance of a ball-mounting positioning ring light source. The image resolution ensures the accuracy of position detection. The position deviation value is the difference between the actual position coordinates of the pad and the preset standard position coordinates, including the X-axis deviation and the Y-axis deviation. The image processor performs feature extraction and coordinate calculation on the captured pad image to obtain the actual position coordinates of the first pad. This is then compared with the standard position coordinates to obtain the accurate position deviation value, which is transmitted to the control system to provide data for the adjustment of the X and Y axis servo screw modules.

[0041] Step S204: Adjust the X and Y axis servo screw modules according to the position deviation value so that the laser focus is aligned with the center of the solder pad.

[0042] Specifically, the X and Y axis servo lead screw modules are an important component of the equipment's drive and positioning system. Their servo motors receive drive signals from the control system based on lateral position deviations. Through the rotation of the precision lead screws, they drive the laser peeling assembly to compensate for movement along the X and Y axes. The module's repeatability is ±0.05mm, ensuring the adjustment accuracy meets requirements. During adjustment, the module's built-in position encoder provides real-time feedback on the actual position. The control system performs closed-loop control based on this feedback until the laser focus emitted by the laser peeling assembly precisely falls on the center of the first pad, ensuring accurate peeling coverage of the pad area and preventing incomplete or excessive peeling.

[0043] Step S205: Determine the target peeling power within the peeling power range based on the pad oxide layer thickness.

[0044] Specifically, the thickness of the solder pad oxide layer can be estimated by analyzing the grayscale values ​​of the solder pad images captured by the visual positioning component. Different oxide layer thicknesses result in different grayscale values. Alternatively, the average oxide layer thickness of the solder pads for the corresponding stator component model can be preset based on previous detection data. The laser power of the equipment's laser peeling component is 5W. Based on the estimated oxide layer thickness, the target peeling power is determined within the preset peeling power range. A higher value within the power range is selected when the oxide layer is thicker, and a lower value is selected when the oxide layer is thinner, in order to achieve precise and efficient peeling while avoiding damage to the solder pad substrate from excessive laser power.

[0045] Step S206: Turn on the laser to perform laser peeling on the first pad, and at the same time use the dust extraction component to remove the dust generated by the peeling.

[0046] Specifically, the laser emits a laser at a predetermined target peeling power. After being transmitted and focused through the optical path, the laser irradiates the surface of the first pad. Under the high temperature of the laser, the oxide layer rapidly vaporizes and forms dust. The dust extraction assembly is connected to the dust extraction port on the back of the equipment and includes a dust extraction hood, a negative pressure pipe, and a dust collector. The dust extraction hood is installed around the laser peeling assembly, close to the pad area. When opened, it generates negative pressure, which promptly sucks the metal dust generated during the peeling process into the dust collector, preventing dust from adhering to the pad surface and affecting the subsequent welding quality, or from entering the equipment and damaging the components, thus ensuring the long-term stable operation of the equipment.

[0047] Step S207: After peeling is completed, the fixture stage is rotated by a preset angle, and the above peeling operation is repeated for the other two pads in sequence.

[0048] Specifically, the preset angle is a rotation angle determined based on the distribution spacing of the three pads. This angle is precisely set based on the pad distribution information of the stator component and matches the rotation accuracy of the hollow rotating platform of the fixture stage. After the first pad is peeled, the control system drives the fixture stage to rotate by the preset angle so that the second pad is directly facing the laser peeling component. Then, steps S203 to S206 are repeated to complete the peeling of the second pad. Similarly, the preset angle is rotated again to complete the peeling operation of the third pad, realizing the alternating laser peeling of the three pads.

[0049] Step S208: After each pad is peeled, the vision positioning component checks the surface condition of the pad again to confirm that the peeling meets the standard.

[0050] Specifically, after each pad is peeled, the vision positioning component takes another image of the pad's surface. The image processor analyzes the image to determine whether the oxide layer on the pad's surface has been completely removed, and whether there is excessive etching or surface damage. The preset peeling standard is that the pad surface has no obvious oxide layer and the surface roughness meets the requirements for subsequent soldering. If the test results meet the standard, the peeling is deemed successful, and the process proceeds to the next pad. If the standard is not met, an alarm signal is issued, the equipment stops operating, and the equipment awaits operator intervention to ensure that the peeling quality of each pad meets the requirements, laying a good foundation for subsequent ball bonding and soldering.

[0051] Reference Figure 3 In one embodiment of this example, step S106, which involves transferring the stator component to the laser ball-mounting station and obtaining the actual position and height data of the solder pads through a vision positioning component, includes steps S301 to S306: Step S301: After the turntable transfers the stator component to the laser ball-planting station, the ball-planting positioning ring light source is activated to illuminate the pad area.

[0052] Specifically, the ball-placement positioning ring light source is an important component of the visual positioning assembly. It is a high-brightness, low-glare LED ring light source installed around the ball-placement positioning camera. Its light intensity and angle can be adjusted according to the surface material of the solder pads, ensuring clear imaging results for pads of different materials. After the turntable accurately transports the stator component to the laser ball-placement station and locks it in place, the control system activates the ball-placement positioning ring light source. The light emitted by the source evenly illuminates the three solder pad areas, eliminating shadows and reflections on the solder pad surfaces. This provides excellent lighting conditions for the 6-megapixel ball-placement positioning camera to capture clear and accurate images of the solder pads, ensuring the accuracy of subsequent position and height detection.

[0053] Step S302: Control the visual positioning camera to take pictures of the three pads simultaneously to obtain pad images.

[0054] Specifically, the visual positioning camera is a high-precision industrial area array camera with 6 megapixels, possessing high resolution and fast shooting capabilities. It can simultaneously cover the shooting range of three solder pads, and the shooting speed meets the production capacity requirements of 6S / product. Under the illumination of a ring light source, the visual positioning camera simultaneously captures images of the three solder pads according to preset shooting parameters (such as exposure time and gain), acquiring a high-definition image containing complete information about all three solder pads in one go. The image data is transmitted to the image processor in real time for subsequent processing, improving detection efficiency and avoiding the time wasted by shooting each solder pad one by one.

[0055] Step S303: Process the pad image using an image algorithm to extract the edge features of each pad.

[0056] Specifically, the image algorithm is integrated into the device software system, including steps such as image preprocessing, edge detection, and noise filtering. Image preprocessing enhances the contrast between the pads and the background; edge detection uses the Canny algorithm to accurately identify the edge contours of the pads; and noise filtering removes interfering noise from the image to ensure the accuracy of edge features. The image processor processes the pad image using the above image algorithms, successfully extracting clear and complete edge features for each pad, laying the foundation for subsequent calculation of the pad center coordinates. The algorithm is fast and does not affect the overall processing efficiency of the device.

[0057] Step S304: Fit the center coordinates of the corresponding pads based on the edge features of each pad, and use the center coordinates of the three pads as the actual positions of each pad.

[0058] Specifically, based on the extracted edge features of individual pads, the least squares method is used to fit a circle to the edge contour, obtaining the center coordinates of each pad. These center coordinates are the center coordinates of the pad and are used as the actual position coordinates of each pad. In this way, the actual position of each pad at the laser ball-planting station can be accurately obtained, effectively compensating for the accumulated errors generated during the previous transfer and positioning processes. The positioning error is controlled within ±0.03mm, providing data for the subsequent precise adjustment of the XYZ axis module and ensuring that the ball-planting nozzle can be accurately aligned with the center of the pad.

[0059] Step S305: Activate the height sensor and, in the order of pad numbers, sequentially sample the height data of a single pad surface at multiple points along the vertical direction corresponding to the center coordinate of each pad.

[0060] Specifically, the height sensor is a laser displacement sensor, an auxiliary detection component of the vision positioning assembly. It possesses high-precision distance measurement capabilities, with a measurement accuracy of ±0.001mm. Installed next to the ball positioning camera, it can move synchronously with the vision positioning assembly. Following a preset pad numbering sequence (e.g., 1, 2, 3), the height sensor moves vertically above the center coordinates of each pad, measuring the height of multiple sampling points on the pad surface along the vertical direction. Each pad has at least five sampling points to ensure that the collected height data accurately reflects the actual height of the pad surface, avoiding data distortion due to errors in individual sampling points.

[0061] Step S306: Calculate the average height based on the multi-point sampling data and use it as the height data for each pad.

[0062] Specifically, the control system performs statistical analysis on the multi-point sampling height data of each pad, removes abnormal data (such as extreme values ​​caused by impurities on the pad surface), calculates the arithmetic mean of the remaining valid data, and uses this average value as the height data of the corresponding pad.

[0063] Reference Figure 4 In one embodiment of this example, step S107, based on the actual position and height data of the pads, adjusts the position parameters of the XYZ axis servo screw module, including steps S401 to S407: Step S401: Based on the actual position and height data of the pads, analyze the lateral position deviation, longitudinal position deviation, and height deviation.

[0064] Specifically, the lateral position deviation is the difference between the actual X-axis coordinate of the pad and the preset standard X-axis coordinate; the longitudinal position deviation is the difference between the actual Y-axis coordinate of the pad and the preset standard Y-axis coordinate. Both reflect the positional offset of the pad in the horizontal plane and correspond to the adjustment direction of the X and Y axis servo screw modules. The height deviation is the difference between the average actual height of the pad and the preset standard height, reflecting the positional offset of the pad in the vertical direction and corresponding to the adjustment direction of the Z-axis servo screw module. The control system compares the acquired actual position and height data of each pad with the preset standard data and analyzes the corresponding lateral position deviation, longitudinal position deviation, and height deviation one by one.

[0065] Step S402: Based on the lateral position deviation, drive the X-axis servo screw module to perform translation adjustment, with the adjustment accuracy controlled within ±0.05mm.

[0066] Specifically, the servo motor of the X-axis servo screw module receives drive signals from the control system based on lateral position deviations. The rotation of the precision screw drives the laser ball-planting assembly to perform translational compensation along the X-axis. The repeatability of the X-axis servo screw module is ±0.05mm. During adjustment, the module's built-in position encoder provides real-time feedback on the actual position information. The control system performs closed-loop control based on this feedback, ensuring that the adjustment accuracy in the X-axis direction is strictly controlled within ±0.05mm, thus precisely aligning the laser ball-planting assembly with the center of the solder pads in the X-axis direction.

[0067] Step S403: Based on the longitudinal position deviation, drive the Y-axis servo screw module to perform translation adjustment to ensure that the laser ball-planting assembly is aligned with the center of the solder pad.

[0068] Specifically, similar to the X-axis adjustment principle, the Y-axis servo screw module drives the laser ball-planting assembly to translate and adjust along the Y-axis direction based on the command issued by the control system based on the longitudinal position deviation. During the adjustment process, combined with the real-time monitoring feedback of the vision positioning component, it is ensured that the nozzle center of the laser ball-planting assembly and the pad center are completely coincident on the horizontal plane, that is, precisely aligned with the pad center.

[0069] Step S404: Based on the height deviation, adjust the lifting height of the Z-axis servo screw module to maintain a preset distance between the ball-planting nozzle and the pad surface.

[0070] Specifically, the preset distance is the optimal spacing between the solder ball nozzle and the pad surface, determined based on the 850-1000μm solder ball diameter, laser focusing characteristics, and welding process requirements. It is typically set to 1-3mm. The Z-axis servo screw module is the vertical adjustment component of the equipment's drive positioning system, with a movement speed range of 0.1~500mm / s and a repeatability of ±0.05mm. Based on the height deviation, the control system drives the Z-axis servo screw module to raise and lower the laser solder ball assembly, adjusting the height of the solder ball nozzle so that the actual distance between the nozzle and the pad surface equals the preset distance. This ensures that the solder ball accurately lands in the center of the pad after being sprayed, and that the laser is precisely focused on the solder ball for effective melting, guaranteeing welding quality.

[0071] Step S405: When both the position deviation and height deviation are less than the allowable threshold, stop the module adjustment and lock the position parameters.

[0072] Specifically, the allowable thresholds are the upper limits of deviation set according to the welding accuracy requirements, combined with the repeatability of the equipment's servo screw module. The allowable thresholds for both lateral and longitudinal position deviations are set to ±0.03mm, and the allowable threshold for height deviation is set to ±0.02mm. The control system monitors the adjusted position and height deviations in real time. When both are less than the corresponding allowable thresholds, the adjustment is deemed satisfactory, and a command is immediately issued to stop the adjustment of the XYZ axis servo screw module. The current position parameters are then locked and stored as fixed parameters for subsequent ball-mounting welding.

[0073] Step S406: If the number of adjustments exceeds the upper limit of the first adjustment and still fails to meet the standard, the nozzle calibration component is activated to calibrate the ball-planting nozzle.

[0074] Specifically, the maximum number of adjustments is set to three. If the position or height deviation of the XYZ axis servo screw module still exceeds the allowable threshold after three adjustments, it is determined that there may be a problem with the ball-planting nozzle offset, rather than pad positioning deviation. The nozzle calibration component includes a contact displacement sensor and a calibration reference block, used to accurately calibrate the center position of the ball-planting nozzle. At this time, the control system starts the nozzle calibration program, moves the ball-planting nozzle above the standard calibration block, and detects the deviation between the nozzle and the standard position of the calibration block using the contact displacement sensor.

[0075] Step S407: After calibration, re-perform pad positioning detection and module adjustment operations.

[0076] Specifically, based on the deviation data detected by the nozzle calibration component, the control system drives the relevant mechanisms to precisely calibrate the ball-planting nozzle, ensuring that the nozzle center position meets the standard requirements and that the calibration accuracy matches the positioning accuracy of the servo screw module. After calibration, the vision positioning component is restarted to perform positioning detection on the pads, obtaining new actual position and height data of the pads. Subsequently, based on the new data, the position adjustment operation of the XYZ axis servo screw module is performed again until the adjustment meets the standard.

[0077] Reference Figure 5 In one embodiment of this invention, step S108 involves spraying solder balls onto the pads using a laser ball-planting assembly, while simultaneously turning on the laser to melt the solder balls, thus completing the ball-planting soldering process, which includes steps S501 to S507. Step S501: Turn on the nitrogen gas source and adjust the gas pressure to 0.2-0.4MPa through the nitrogen pressure regulating valve. After the nitrogen is purified by the filter, it is introduced into the gas line.

[0078] Specifically, the nitrogen pressure regulating valve is installed on the nitrogen filter and pressure regulating valve assembly on the back of the equipment. It is used to regulate the high-pressure nitrogen to a preset working pressure of 0.2-0.4 MPa. This pressure range ensures that the solder balls are pushed smoothly and accurately to the nozzle. The filter is integrated with the nitrogen pressure regulating valve to filter out moisture, impurities, etc. in the nitrogen, preventing impurities from clogging the gas path or affecting the welding quality. After pressure regulation and filtration, the nitrogen is introduced into the gas path system of the laser ball-planting assembly, providing power for the delivery of the solder balls and providing a protective atmosphere for the welding process.

[0079] Step S502: After receiving the ventilation signal, the solenoid valve is turned on, and nitrogen flows into the electro-proportional valve for secondary pressure regulation, outputting a constant low-pressure airflow.

[0080] Specifically, the solenoid valve is an electromagnetically controlled pneumatic valve installed in the nitrogen gas path for ball placement. It controls the on / off state of the nitrogen gas path, quickly opening upon receiving a gas supply signal from the control system, exhibiting a fast response speed. The electro-proportional valve is integrated into the laser ball placement assembly, capable of precisely regulating the pressure of the nitrogen gas after its initial pressure regulation according to the control system's instructions. This results in a constant low-pressure airflow with a pressure fluctuation range of less than ±0.01 MPa. This secondary pressure regulation of the low-pressure airflow is more suitable for the stable delivery of 850-1000μm solder balls, preventing excessively fast or misaligned delivery of the solder balls due to high-pressure airflow, and ensuring that the solder balls accurately enter the ball placement nozzle.

[0081] Step S503: The low-pressure airflow pushes 850-1000μm solder balls from the ball storage chamber to the ball planting nozzle. The solder balls block the nozzle orifice, causing the air pressure in the nozzle chamber to rise.

[0082] Specifically, the ball storage chamber is a sealed chamber that stores a large number of solder balls with a diameter of 850-1000μm. A ball delivery channel at the bottom connects to the ball placement nozzle. The nozzle orifice diameter is slightly larger than the solder ball diameter to ensure that a single solder ball can smoothly enter the nozzle orifice and block it, preventing multiple solder balls from entering simultaneously and causing blockage. Low-pressure airflow enters the ball storage chamber through the ball delivery channel, propelling the solder balls along the channel towards the ball placement nozzle. Once a single solder ball enters the nozzle orifice and blocks it, the nitrogen in the nozzle chamber cannot escape, causing the chamber pressure to gradually rise, providing a pressure signal for subsequent ball detection.

[0083] Step S504: After the differential pressure sensor detects that the air pressure has risen to a preset value, it sends a ball signal to the control system.

[0084] Specifically, a differential pressure sensor is installed in the nozzle chamber of the solder ball placement nozzle. As a detection component of the laser solder ball placement assembly, it detects the difference between the air pressure inside the nozzle chamber and the external atmospheric pressure. The preset value is a pressure difference determined based on the nozzle orifice diameter, solder ball diameter, and airflow pressure. When the solder ball completely blocks the nozzle orifice, the air pressure inside the nozzle chamber will rise to this preset value. The differential pressure sensor monitors air pressure changes in real time and has a fast response speed. When it detects that the air pressure has risen to the preset value, it determines that a solder ball has reached the ready position in the nozzle orifice and immediately sends a ball presence signal to the control system, indicating that subsequent laser soldering operations can proceed, ensuring the synchronization of laser emission and solder ball arrival.

[0085] Step S505: After receiving the ball signal, the control system controls the laser to prepare to emit light, and at the same time adjusts the light emission time to the preset time.

[0086] Specifically, after receiving the ball signal, the control system immediately sends a preparation command to the 200W stator ball-planting laser. The laser starts the preheating program and enters the standby state. The laser power meets the equipment technical parameter requirements. The preset duration is the laser emission time determined according to the diameter, material and welding requirements of the 850-1000μm solder ball. It can be set through the process debugging interface of the software system. It is usually set to 0.5-2ms to ensure that the solder ball can be completely melted without damaging the pad substrate.

[0087] Step S506: The laser emitted by the laser is focused by the collimating lens and the focusing lens, and then shines on the solder ball in the nozzle through the laser through hole.

[0088] Specifically, the laser via is a through-hole located at the center of the ball-planting nozzle. The laser can directly irradiate the solder ball inside the nozzle through this via, avoiding laser energy loss. The laser emits laser light according to preset parameters, which, after collimation and focusing, precisely irradiates the solder ball inside the nozzle through the laser via. The solder ball absorbs the laser energy and heats up rapidly, achieving rapid melting.

[0089] Step S507: After the solder balls melt, they are ejected from the nozzle under air pressure, fall onto the surface of the solder pad, and complete the ball placement and soldering.

[0090] Specifically, the solder balls rapidly melt into liquid solder under the high temperature of a 200W laser. At this time, the nitrogen pressure inside the nozzle chamber is greater than the external atmospheric pressure. Under the influence of this pressure difference, the liquid solder is pushed out of the nozzle orifice and precisely lands on the surface of the pad pre-sprayed with flux, with the spray direction aligned with the center of the pad. Under the action of the flux, the liquid solder spreads rapidly and forms a good metallurgical bond with the surface of the pad. As the laser stops emitting light, the liquid solder quickly cools and solidifies, forming a full and stable solder joint, completing the ball placement and soldering of a single pad.

[0091] In one embodiment of this invention, after the solder balls melt in step S507, they are ejected from the nozzle under air pressure, fall onto the surface of the solder pads, and complete the solder ball placement, including steps S601 to S608: Step S601: The visual positioning component switches to the solder joint detection mode and acquires images of the solder joints that have just been welded.

[0092] Specifically, the solder joint detection mode is a dedicated detection mode preset by the vision positioning component. Unlike the positioning mode, the illumination intensity and angle of the ball-mounting positioning ring light source are adjusted to the most suitable state for solder joint detection. The shooting parameters of the 6-megapixel ball-mounting positioning camera are also optimized accordingly to clearly capture features such as the surface morphology, contour, and molten solder spread of the solder joint. The vision positioning component moves above the newly soldered solder joint and acquires a high-definition image of it, containing complete information about the solder joint.

[0093] Step S602: Analyze the solder joints based on the pad edge features and the actual position of the pads, and obtain the analysis results.

[0094] Specifically, combining the previously acquired pad edge features and actual location data, the image processor performs multi-dimensional analysis on the collected solder joint images. These analysis dimensions include the solder joint's outline integrity, solder joint diameter (compared to a preset standard diameter), solder joint height (compared to height measurement data), concentricity between the solder joint and the pad (compared to the pad's center coordinates), and the presence of defects such as porosity or cracks on the surface. By comparing the analyzed data with preset solder joint acceptance standard parameters, the analysis result indicating whether the solder joint meets the requirements is obtained.

[0095] Step S603: Based on the analysis results, determine whether there is a target defect.

[0096] Specifically, the target defects are preset key defect types that affect soldering quality, including cold solder joints, insufficient solder, solder ball misalignment, solder joint porosity, and cracks. The defect judgment criteria are based on user requirements and industry standards. The control system determines whether the current solder joint has the above-mentioned target defects based on the analysis results of the image processor. If all the analyzed data are within the acceptable range, it is determined that there are no target defects; if one or more data exceed the acceptable range, it is determined that there are target defects.

[0097] Step S604: If a target defect exists, record the defect type and the corresponding pad location.

[0098] Specifically, when a target defect is detected, the control system automatically records the specific type of the defect. Simultaneously, combining this with previously acquired data on the actual location and numbering of the solder pads, it records the number and specific coordinates of the defective solder pad. This defect information is stored in the equipment database in real time and linked to the processing information of the stator component (such as processing time and equipment parameters). This facilitates subsequent tracing of product quality issues and provides precise information on the defect location and type for subsequent repair soldering operations, ensuring targeted repair.

[0099] Step S605: Automatically adjust the laser power and light emission time and start the repair welding program to repair the weld points with target defects and re-inspect them.

[0100] Specifically, the equipment software system has built-in adjustment strategies for repair parameters corresponding to different defect types. These can be preset and modified in the process debugging interface. For example, for cold solder joint defects, the laser power needs to be increased by 10%-15% and the light emission time extended by 0.2-0.5ms. For insufficient solder defects, in addition to adjusting the laser parameters, the nitrogen pressure needs to be fine-tuned through the gas path system to increase the solder ball delivery volume. Based on the recorded defect type, the control system automatically adjusts parameters such as laser power and light emission time, starts the repair soldering program, and drives the XYZ axis module to move the ball placement assembly to the defective solder joint for targeted repair soldering. After the repair soldering is completed, the vision positioning component switches back to the solder joint detection mode to re-acquire and analyze images of the repaired solder joint to ensure the quality of the repair soldering.

[0101] Step S606: If the target defect still exists after the number of welding repairs reaches the upper limit for the second time, the corresponding stator component is marked as a defective product, an alarm signal is sent, and the material unloading and diversion are triggered.

[0102] Specifically, the maximum number of weld attempts is set to two. This value can be adjusted through the software parameter settings interface. If the target defect still exists at the weld point after two weld attempts, the stator component is determined to be unrepairable and the control system marks it as a defective product. Simultaneously, the three-color indicator lights on the front of the equipment emit an audible and visual alarm signal to alert the operator and trigger the material handling and diversion mechanism. During material handling, the robotic arm, according to the control system's instructions, transfers the defective product to a designated defective product collection area to avoid confusion with qualified products and ensure the effectiveness of product quality control.

[0103] Step S607: After the solder joint inspection is qualified, store the inspection data and solder joint image.

[0104] Specifically, once a weld point passes inspection (including initial weld pass and subsequent repair weld pass), the control system associates and stores the weld point's inspection data (such as weld point diameter, height, concentricity, defect detection results, etc.) and the collected weld point image in the equipment database. This data is then linked with the corresponding stator component's model parameters, processing time, equipment number, operator, and other information to form a complete product quality file.

[0105] Step S608: The fixture stage rotates at a preset angle to perform ball bonding and inspection on the next pad.

[0106] Specifically, after the ball placement welding and inspection (or repair welding inspection) of the current pad is completed, the control system drives the hollow rotating platform of the fixture to rotate by a preset angle, which is consistent with the distribution spacing of the three pads, with a rotation accuracy of ±0.01°, so that the next pad to be processed is moved to the working position of the laser ball placement assembly. Then, the ball placement welding and inspection process of steps S107 to S607 is repeated until all three pads are processed.

[0107] In one embodiment of this example, step S605, which automatically adjusts the laser power and emission duration and starts the repair welding procedure, includes steps S701 to S708: Step S701: Obtain the defect type and defect severity parameters of the unqualified solder joints. The defect types include cold solder joints, insufficient solder, and solder ball misalignment.

[0108] Specifically, the defect severity parameter is a quantitative indicator reflecting the severity of a defect. It can be automatically calculated using the image analysis function of the software system. For example, the defect severity parameter for insufficient solder can be calculated by the difference between the actual volume and the standard volume of the solder joint and the percentage of that difference. The defect severity parameter for solder ball misalignment can be determined by the ratio of the misalignment distance to the radius of the solder pad. The defect severity parameter for cold solder joints can be determined by the ratio of the molten solder spreading area to the standard area. The control system extracts the defect type and corresponding defect severity parameter of the unqualified solder joints from the previously recorded defect information, providing detailed basis for the subsequent accurate formulation of repair soldering strategies and ensuring the rationality of the repair soldering parameter adjustments.

[0109] Step S702: Match the corresponding repair welding strategy library based on the defect type.

[0110] Specifically, the equipment software system has a comprehensive library of solder repair strategies pre-installed. This library is categorized and stored according to defect type, with each defect type corresponding to multiple solder repair parameter adjustment schemes. These schemes are further subdivided based on the severity of the defect and can be updated and optimized through the software parameter setting interface. For example, for insufficient solder content defects, mild insufficiency (difference percentage ≤ 10%) corresponds to one set of parameter adjustment schemes (e.g., laser power +10%, light emission time +0.3ms), while moderate insufficiency (10% < difference percentage ≤ 20%) corresponds to another scheme with a larger adjustment range (e.g., laser power +15%, light emission time +0.5ms, nitrogen pressure +0.03MPa). The control system matches the corresponding set of solder repair schemes from the solder repair strategy library based on the acquired defect type.

[0111] Step S703: Retrieve the standard welding parameters corresponding to the stator component model, and calculate the laser power adjustment range and the correction value of the light output time based on the defect degree parameters.

[0112] Specifically, the equipment database pre-stores standard welding parameters for different stator component models, including standard laser power (200W base value), standard beam duration, and standard nitrogen pressure, which can be automatically retrieved based on the stator component model. Then, based on the matched set of repair welding schemes and the defect severity parameters, the software system's built-in algorithm calculates the specific laser power adjustment range and beam duration correction value. For example, for a slight insufficient solder defect, the calculated laser power adjustment range is +10% (i.e., 220W), and the beam duration correction value is +0.3ms, ensuring that the adjusted parameters accurately compensate for the defect while avoiding over-adjustment that could lead to new quality problems.

[0113] Step S704: Adjust the XYZ axis servo screw module so that the ball-planting nozzle is re-aligned with the center of the defective weld point.

[0114] Specifically, based on the previously recorded coordinates of the defective solder pad and the center coordinates of the solder joint, the control system drives the XYZ axis servo screw module to move precisely. The XYZ axis module has a repeatability of ±0.05mm, moving the ball-placement nozzle directly above the defective solder joint. During the adjustment process, in conjunction with real-time monitoring by the vision positioning component, the position is calibrated by capturing images with a 6-megapixel camera to ensure that the center of the ball-placement nozzle completely coincides with the center of the defective solder joint, with a deviation not exceeding ±0.02mm.

[0115] Step S705: Turn on the nitrogen protection gas circuit and fine-tune the gas pressure to 0.05MPa higher than the original welding gas pressure.

[0116] Specifically, during the repair soldering process, the nitrogen protective gas path is turned on. The nitrogen has a purity of 99.99%, which can effectively prevent the molten solder from being oxidized, improve the quality of the repair solder joint, and avoid defects such as oxidation inclusions. The gas pressure is slightly adjusted to be 0.05MPa higher than the original welding gas pressure to ensure that the solder ball can be pushed more smoothly and accurately to the defective solder joint during the repair soldering, while promoting better spread of the molten solder to make up for the original defective area.

[0117] Step S706: Start the repair welding according to the adjusted parameters. During the repair welding process, the vision positioning component collects images of the welding point melting status in real time.

[0118] Specifically, the control system activates the 200W laser and solder ball delivery system to perform the repair soldering operation based on the calculated and adjusted laser power, light emission time, and other parameters. The repair soldering parameters are precisely matched to the type and severity of the defect. During the repair soldering process, the ball positioning camera of the vision positioning component captures images of the melting state of the solder joint in real time. The image data is transmitted to the control system in real time, and the operator can observe the repair soldering process in real time through the display on the front of the equipment. At the same time, the control system also monitors the spread of molten solder based on the image data, and can stop the repair soldering in time if any abnormality occurs.

[0119] Step S707: Monitor the molten solder spreading range and solidification trend through image algorithms. If the preset standard is reached, stop the soldering.

[0120] Specifically, the image processor analyzes the real-time acquired images of molten solder using the built-in image algorithms of the software system. It monitors whether the spread of the molten solder reaches the preset acceptable range (e.g., spread to the inner edge of the pad 0.1-0.2mm, with a concentricity deviation from the pad ≤0.03mm). Simultaneously, it analyzes the grayscale changes of the molten solder to determine its solidification trend (a stable grayscale value indicates the start of solidification). When the molten solder spread is detected to be within acceptable limits and shows a solidification trend, the control system immediately issues a command to stop the resoldering, preventing new defects (such as oversized solder joints or solder ball adhesion) caused by excessive resoldering, and ensuring that the resoldered joint meets quality standards.

[0121] Step S708: After the repair welding is completed, the height sensor will detect the height of the weld point again and compare it with the standard height range to confirm that the repair welding meets the standard.

[0122] Specifically, after the welding repair is completed and the weld joint cools and solidifies, the height sensor (measurement accuracy ±0.001mm) is moved vertically above the weld joint to accurately measure its height. The measurement method is the same as in step S305, using multi-point sampling and averaging to ensure the accuracy of the height data. The measured weld joint height is compared with the standard height range for the corresponding stator component of this model. If the measured height is within the standard range, and the outline, concentricity, and other indicators detected by visual inspection are all qualified, the welding repair is deemed satisfactory. If it still exceeds the standard range, the welding repair is deemed unsatisfactory, and the control system will record this situation, subsequently executing the non-conforming product handling process in step S606.

[0123] In one embodiment of this example, after step S702, which matches the corresponding repair welding strategy library based on the defect type, steps S801 to S807 are further included: Step S801: If the defect type is solder ball adhesion and the adhesion range exceeds 1.5 times the diameter of a single pad, start a special separation procedure.

[0124] Specifically, solder ball adhesion is a defect formed when solder balls on two or more solder pads melt and connect with each other. It is a relatively serious soldering defect. The extent of adhesion is determined by measuring the maximum diameter of the adhesion area using software image algorithms. When the adhesion area exceeds 1.5 times the diameter of a single solder pad, conventional resoldering cannot repair it, and a special separation procedure must be initiated. This procedure is a dedicated processing program designed for solder ball adhesion defects and integrated into the equipment software system. Its purpose is to separate the adhered solder balls, restore the independence of each solder joint, and prevent stator component malfunction due to adhesion.

[0125] Step S802: Control the Z-axis servo screw module to raise the ball-planting nozzle to the preset safe height, switch the nitrogen gas path to high-pressure mode, and adjust the gas pressure to 0.3-0.35MPa.

[0126] Specifically, the preset safety height is set to a distance of 10-15mm between the ball-planting nozzle and the pad surface. This height is preset through the software parameter setting interface. Raising the nozzle to this height can prevent damage to the nozzle or pad surface during subsequent high-pressure nitrogen injection. The high-pressure mode is a dedicated working mode for the nitrogen gas path. The gas pressure is adjusted to a high-pressure range of 0.3-0.35MPa through the nitrogen pressure regulating valve on the back of the equipment (this pressure range is within the parameter range of 0.2-0.4MPa for the equipment's nitrogen gas source). This gas pressure can generate sufficient impact force to separate the adhered solder balls without excessively damaging the solder joints and pad substrate.

[0127] Step S803: Inject high-pressure nitrogen gas into the adhesion area through the nozzle, and stop spraying after a preset time.

[0128] Specifically, the control system controls the solenoid valve to open the high-pressure nitrogen gas path. The high-pressure nitrogen gas is precisely sprayed through the ball-mounting nozzle onto the area where the solder balls are stuck together, with the spray direction aimed at the center of the stuck area. The preset time is set to 0.5-1 second, which can be adjusted via software parameters. Too long a spray time may cause solder joint deformation or molten solder splashing, while too short a time will not effectively separate the stuck solder balls. During the spraying process, the vision positioning component monitors the changes in the stuck area in real time to ensure accurate spraying position and avoid deviation from the stuck area. After the preset time is completed, the solenoid valve closes, and the spraying stops.

[0129] Step S804: The visual positioning component captures an image of the adhered area to determine whether the solder balls have separated.

[0130] Specifically, after the jetting stops, the 6-megapixel camera of the vision positioning component immediately captures a high-resolution image of the adhered area. The image processor analyzes the contours of each solder pad and solder joint in the image using software image algorithms to determine whether the adhered solder balls have separated and whether each solder joint has returned to an independent state. The separation criteria are that the contours of each solder joint are clear and there are no interconnected solder bridges. If the criteria are met, the solder balls are considered to have been successfully separated; if adhesion still exists, the separation is considered to have failed, and subsequent heating-assisted separation operations are required.

[0131] Step S805: If separation is not achieved, adjust the laser power to 80% of the original power, turn on the laser for local heating, and simultaneously purge with low-pressure nitrogen gas.

[0132] Specifically, if the solder balls do not separate, local heating is needed to soften the adhered molten solder, reducing its viscosity and facilitating separation. Adjusting the laser power to 80% of the original welding power (i.e., 160W, based on a 200W standard power) avoids excessive melting of the solder joints or damage to the pads due to excessive power. The laser is then turned on to locally scan and heat the adhered area; the scanning path is preset by software and focused on the adhered area. Simultaneously, the nitrogen gas path is switched back to low-pressure mode (0.2-0.25MPa), and low-pressure nitrogen is sprayed into the heated area through nozzles for purging. The impact force of the airflow assists in separating the softened solder balls, while the low-pressure nitrogen also protects the molten solder from oxidation.

[0133] Step S806: Confirm the separation status again through visual inspection. After successful separation, restore the original welding parameters and perform re-welding.

[0134] Specifically, after local heating and low-pressure nitrogen purging are completed, the vision positioning component takes another image to detect the separation status, and the detection standard is the same as in step S804. If separation is successful, the nitrogen pressure, laser power, and other parameters are restored to the original repair welding parameters (repair welding strategy parameters based on defect type and severity matching). Then, each weld point after separation is repaired according to the normal repair welding process to ensure that the diameter, height, concentricity, and other indicators of each weld point meet the quality requirements. If separation still fails, the operation of step S805 is repeated until separation is successful or the preset maximum number of separation attempts is reached.

[0135] Step S807: If the number of separations still fails to meet the standard after reaching the third threshold, record the corresponding stator component as a seriously defective product and send an alarm signal.

[0136] Specifically, the threshold for the third separation operation is set to 3 times. This value can be adjusted through the software parameter settings interface. If the solder balls still cannot be separated after 3 separation operations, the stator component is determined to be a seriously defective product and cannot be repaired to meet quality requirements. The control system records relevant information about the stator component (such as model, processing time, defect details, number of separation operations, etc.) and issues a strong audible and visual alarm signal (flashing red light on the equipment's three-color indicator + continuous buzzer alarm) to remind operators to handle the issue promptly. At the same time, the component is marked as a seriously defective product and will be directly diverted to the waste collection area during subsequent material handling to prevent it from flowing into the next process.

[0137] Secondly, this application also discloses a laser ball-planting system for stator components.

[0138] Reference Figure 6 A laser ball-mounting system for stator components, comprising: The parameter acquisition module is used to acquire the model parameters and pad distribution information of the stator components; The positioning module is used to place the stator component on the fixture platform and to perform axial positioning of the stator component by means of the fixture jaws; The transfer module is used to activate the four-station turntable and transfer the stator components to the laser peeling station; The laser peeling module is used to adjust the power and position of the laser peeling component based on the pad distribution information of the stator component, and to perform laser peeling on the pads corresponding to the three copper wire pins. The flux spraying module is used to transfer the stator component to the flux station after peeling, and precisely spray flux onto the three pads through the flux piezoelectric valve. The data acquisition module is used to transfer stator components to the laser ball-mounting station and acquire the actual position and height data of the pads through the vision positioning component; The parameter adjustment module is used to adjust the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads. The ball-mounting and soldering module is used to spray solder balls onto the pads via a laser ball-mounting component, while simultaneously turning on the laser to melt the solder balls, thus completing the ball-mounting and soldering process. The unloading module is used to transfer the stator components back to the loading position by the turntable after the ball planting is completed, and the unloading operation is performed by the robot arm to enter the next product cycle.

[0139] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A laser ball-mounting method for stator components, characterized in that, include: Obtain the model parameters and pad distribution information of the stator components; The stator component is placed on the fixture platform, and the stator component is axially positioned by the fixture jaws; Start the four-station turntable to transfer the stator components to the laser peeling station; Based on the stator component pad distribution information, the power and position of the laser peeling component are adjusted to perform laser peeling on the pads corresponding to the three copper wire pins. After peeling, the turntable transports the stator component to the flux application station, where flux is precisely sprayed onto the three solder pads via a flux piezoelectric valve. The stator components are transferred to the laser ball-mounting station, and the actual position and height data of the pads are obtained through a vision positioning component. Adjust the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads; Solder balls are sprayed onto the pads using a laser ball-planting assembly. Simultaneously, the laser is activated to melt the solder balls. Once melted, the solder balls are ejected from the nozzle under air pressure, fall onto the pad surface, and complete the ball-planting process. The completion of ball-planting welding includes a vision positioning component detecting the weld point that has just been welded. If a target defect is found, the laser power and light emission time are automatically adjusted and the repair welding program is started. After the ball is planted, the turntable transfers the stator component back to the loading position, where it is unloaded by a robotic arm and enters the next product cycle. The automatic adjustment of laser power and emission duration and the initiation of the repair welding procedure include: Obtain the defect type and defect severity parameters of the unqualified solder joints. Defect types include cold solder joints, insufficient solder, and solder ball misalignment. A library of repair welding strategies based on defect type matching; Retrieve the standard welding parameters corresponding to the stator component model, and calculate the laser power adjustment range and the correction value of the light output time based on the defect degree parameters; Adjust the XYZ axis servo lead screw module so that the ball-planting nozzle is re-aligned with the center of the defective weld point; Turn on the nitrogen protection gas circuit and fine-tune the gas pressure to 0.05 MPa higher than the original welding gas pressure; The repair welding was started according to the adjusted parameters. During the repair welding process, the visual positioning component collected images of the melting state of the weld point in real time. The image algorithm monitors the molten solder spreading range and solidification trend, and stops the soldering repair if the preset standard is reached. After the welding repair is completed, the height sensor will check the height of the weld point again and compare it with the standard height range to confirm that the welding repair meets the standard. Following the defect type matching-based repair welding strategy library, the following is also included: If the defect type is solder ball adhesion and the adhesion range exceeds 1.5 times the diameter of a single pad, a special separation procedure will be initiated. Control the Z-axis servo screw module to raise the ball-planting nozzle to the preset safe height, switch the nitrogen gas path to high-pressure mode, and adjust the gas pressure to 0.3-0.35MPa; High-pressure nitrogen gas is sprayed into the adhesion area through the nozzle, and the spraying is stopped after a preset time. The visual positioning component captures images of the adhered area to determine whether the solder balls have separated. If separation fails, adjust the laser power to 80% of the original power, turn on the laser for local heating, and simultaneously purge with low-pressure nitrogen gas. The separation status was confirmed again by visual inspection. After successful separation, the original welding parameters were restored for repair welding. If the separation count still fails to meet the standard after reaching the third threshold, the corresponding stator component is recorded as a seriously defective product, and an alarm signal is sent.

2. The laser ball-mounting method for stator components according to claim 1, characterized in that, The step of adjusting the power and position of the laser peeling component based on the stator component pad distribution information to perform laser peeling on the pads corresponding to the three copper wire leads includes: Based on the model parameters of the stator component, retrieve the preset standard position coordinates of the solder pads and the tare power range; By using the rotation function of the fixture stage, the first pad is aligned with the laser peeling component; Based on the stator component pad distribution information, the vision positioning component is activated to detect the position of the first pad and obtain the position deviation value. Adjust the X and Y axis servo screw modules according to the position deviation value so that the laser focus is aligned with the center of the solder pad; Based on the thickness of the solder pad oxide layer, the target peeling power is determined within the peeling power range; The laser is turned on to perform laser peeling on the first pad, while the dust generated by the peeling is removed by the dust extraction component. After peeling is completed, the fixture stage is rotated by a preset angle, and the above peeling operation is repeated for the other two pads in turn; After each pad is peeled, the vision positioning component checks the surface condition of the pad again to confirm that the peeling meets the standard.

3. The laser ball-mounting method for stator components according to claim 1, characterized in that, The process of transferring the stator component to the laser ball-mounting station, and obtaining the actual position and height data of the solder pads through a vision positioning component, includes: After the turntable transfers the stator components to the laser ball-planting station, the ball-planting positioning ring light source is activated to illuminate the pad area. The visual positioning camera is controlled to take pictures of the three pads simultaneously to obtain pad images; Image processing algorithms are used to process the pad images and extract the edge features of each pad. The center coordinates of the corresponding pads are fitted based on the edge features of each pad, and the center coordinates of the three pads are used as the actual positions of each pad. Start the height sensor and, according to the pad numbering order, sequentially sample the height data of a single pad surface at multiple points along the vertical direction corresponding to the center coordinate of each pad. Based on multi-point sampling data, the average height is calculated and used as the height data for each pad.

4. The laser ball-mounting method for stator components according to claim 1, characterized in that, The adjustment of the position parameters of the XYZ axis servo screw module based on the actual position and height data of the solder pads includes: Based on the actual position and height data of the pads, analyze the lateral position deviation, longitudinal position deviation, and height deviation; Based on the lateral position deviation, the X-axis servo screw module is driven to perform translation adjustment, with the adjustment accuracy controlled within ±0.05mm; Based on the longitudinal position deviation, the Y-axis servo screw module is driven to perform translational adjustment to ensure that the laser ball-planting assembly is aligned with the center of the pad. Based on the height deviation, adjust the lifting height of the Z-axis servo screw module to maintain a preset distance between the ball-planting nozzle and the pad surface; When both the position deviation and height deviation are less than the allowable threshold, stop the module adjustment and lock the position parameters. If the number of adjustments exceeds the upper limit for the first adjustment and the target is still not met, the nozzle calibration component will be activated to calibrate the ball-planting nozzle. After calibration, the pad positioning test and module adjustment were performed again.

5. The laser ball-mounting method for stator components according to claim 1, characterized in that, The process of spraying solder balls onto the pads using a laser ball-planting assembly, while simultaneously activating the laser to melt the solder balls, and then ejecting them from the nozzle under air pressure to land on the pad surface and complete the ball-planting process includes: Turn on the nitrogen gas source and adjust the gas pressure to 0.2-0.4MPa through the nitrogen pressure regulating valve. The nitrogen gas is then purified by the filter and introduced into the gas line. After receiving the ventilation signal, the solenoid valve is turned on, and nitrogen flows into the electro-proportional valve for secondary pressure regulation, outputting a constant low-pressure airflow. A low-pressure airflow pushes 850-1000μm solder balls from the ball storage chamber to the ball planting nozzle. The solder balls block the nozzle orifice, causing the air pressure in the nozzle chamber to rise. After the differential pressure sensor detects that the air pressure has risen to a preset value, it sends a ball signal to the control system. After receiving the ball signal, the control system controls the laser to prepare to emit light and adjusts the light emission duration to the preset duration. The laser emitted by the laser is focused by the collimating lens and the focusing lens, and then shines on the solder ball in the nozzle through the laser through-hole; After the solder balls melt, they are ejected from the nozzle under air pressure, fall onto the surface of the solder pads, and complete the solder ball placement.

6. The laser ball-mounting method for stator components according to claim 5, characterized in that, After the solder balls melt, they are ejected from the nozzle under air pressure, fall onto the solder pad surface, and complete the solder ball placement process, including: The visual positioning component switches to solder joint detection mode to acquire images of the solder joints that have just been welded. Based on the pad edge features and the actual position of the pad, the solder joints are analyzed and the analysis results are obtained; Based on the analysis results, determine whether the target defect exists; If the target defect exists, record the defect type and the corresponding pad location; The laser power and emission time are automatically adjusted and the repair welding program is started to repair the weld points with the target defects and re-inspect them; If the target defect still exists after the second welding repair count reaches the upper limit, the corresponding stator component will be marked as a defective product, an alarm signal will be sent, and the material unloading and diversion will be triggered. After the solder joints pass inspection, the inspection data and solder joint images are stored. The fixture platform rotates to a preset angle to perform ball bonding and inspection processes on the next pad.

7. A laser ball-mounting system for stator components, used to perform the method according to any one of claims 1 to 6, characterized in that, include: The parameter acquisition module is used to acquire the model parameters and pad distribution information of the stator components; The positioning module is used to place the stator component on the fixture platform and to perform axial positioning of the stator component by means of the fixture jaws; The transfer module is used to activate the four-station turntable and transfer the stator components to the laser peeling station; The laser peeling module is used to adjust the power and position of the laser peeling component based on the pad distribution information of the stator component, and to perform laser peeling on the pads corresponding to the three copper wire pins. The flux spraying module is used to transfer the stator component to the flux station after peeling, and precisely spray flux onto the three pads through the flux piezoelectric valve. The data acquisition module is used to transfer stator components to the laser ball-mounting station and acquire the actual position and height data of the pads through the vision positioning component; The parameter adjustment module is used to adjust the position parameters of the XYZ axis servo screw module based on the actual position and height data of the pads. The ball-mounting and soldering module is used to spray solder balls onto the pads via a laser ball-mounting component, while simultaneously turning on the laser to melt the solder balls, thus completing the ball-mounting and soldering process. The unloading module is used to transfer the stator components back to the loading position by the turntable after the ball planting is completed, and the unloading operation is performed by the robot arm to enter the next product cycle.

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