Laser soldering process control method and device, electronic equipment, medium and product

Abstract

The application relates to the field of welding processes, and provides a laser tin soldering process control method and device, electronic equipment, medium and product, which comprises the following steps: acquiring actual values of process parameters in a laser tin soldering process; the process parameters comprise a soldering temperature, a tin liquid melting state coupling coefficient and a tin liquid spreading pad area coupling coefficient; the tin liquid melting state coupling coefficient refers to the ratio of the mass of tin liquid in a molten state to the total mass of tin paste; the tin liquid spreading pad area coupling coefficient refers to the ratio of the area of tin liquid in a molten state spreading on a pad surface to the total area of a pad weldable region; and based on the deviation amount between the actual values of the process parameters and preset process parameter reference values, laser output power and soldering time are compensated and controlled. The application realizes multi-dimensional and high-precision real-time control of soldering quality, improves soldering point quality, and improves the first-time soldering qualification rate.

Description

Technical Field

[0001] This application relates to the field of welding process technology, and in particular to laser soldering process control methods, apparatus, electronic equipment, media and products. Background Technology

[0002] With the continuous development of technology, laser soldering technology has been widely used in the field of PCB board pin soldering for motor controllers. During the laser soldering process, the flux in the solder paste expands and vaporizes when heated, which can easily cause soldering spatter. If the resulting solder balls fall into the air gap between the motor rotor and stator, it may lead to serious quality problems such as abnormal motor noise or even seizure.

[0003] Currently, quality monitoring of laser soldering mainly relies on post-soldering quality monitoring, which makes it difficult to detect and intervene in the formation of defects during the welding process in a timely manner, resulting in poor timeliness. Furthermore, the existing real-time monitoring methods in the welding process are limited and lack sufficient correlation with the final quality of the solder joint, leading to problems such as large fluctuations in welding quality, low first-pass yield, and high rework costs on the production line.

[0004] Therefore, how to dynamically control process parameters during laser soldering to improve the final quality of solder joints is an urgent problem to be solved. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the related art. To this end, this application proposes a laser soldering process control method, which can not only adjust the laser output power in real time to correct the temperature deviation according to the soldering temperature deviation, but also dynamically adjust the soldering time according to the actual melting progress and spreading state of the solder paste, thereby achieving multi-dimensional and high-precision soldering quality control, thus improving the solder joint quality and increasing the first-pass yield.

[0006] The laser soldering process control method according to the first aspect of this application includes: Obtain the actual values ​​of process parameters during laser solder paste soldering; the process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt state coupling coefficient refers to the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad; Based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters, the laser output power and welding time are compensated and controlled.

[0007] According to the laser soldering process control method of this application, the actual values ​​of welding temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient are acquired in real time during the laser solder paste welding process. These actual values ​​of process parameters are compared with their respective preset reference values. When any actual value of a process parameter deviates from its corresponding reference value, the laser output power and welding time are compensated and controlled according to the deviation, so that the actual values ​​of each process parameter approach the reference value in real time. This achieves dynamic closed-loop control of the laser solder paste welding process, which is beneficial to improving the stability and consistency of welding quality and reducing the welding defect rate caused by process parameter fluctuations. This application can not only adjust the laser output power in real time to correct the temperature deviation according to the welding temperature deviation, but also dynamically adjust the welding time according to the actual melting progress and spreading state of the solder paste, realizing multi-dimensional and high-precision welding quality control, thereby improving the solder joint quality and the first-pass yield.

[0008] According to one embodiment of this application, the compensation control of laser output power and welding time based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters includes: Based on the deviation between the actual welding temperature and the reference welding temperature, a power correction factor is determined, and the laser output power is compensated and controlled based on the power correction factor. Based on the deviation between the actual value of the coupling coefficient of the molten tin state and the reference value of the coupling coefficient of the molten tin state, and / or the deviation between the actual value of the coupling coefficient of the molten tin spreading pad area and the reference value of the coupling coefficient of the molten tin spreading pad area, a time correction factor is determined, and the soldering time is compensated and controlled based on the time correction factor.

[0009] According to one embodiment of this application, determining the power correction factor based on the deviation between the actual welding temperature value and the welding temperature reference value includes: Based on the deviation between the actual welding temperature and the welding temperature reference value, the corresponding power correction factor is determined according to the preset temperature deviation-power correction factor mapping relationship.

[0010] According to one embodiment of this application, when the actual welding temperature is less than the welding temperature reference value, the power correction factor is greater than 1 and less than or equal to a first preset threshold; when the actual welding temperature is greater than the welding temperature reference value, the power correction factor is greater than or equal to a second preset threshold and less than 1; when the actual welding temperature is equal to the welding temperature reference value, the power correction factor is 1.

[0011] According to one embodiment of this application, the compensation control of the laser output power based on the power correction factor includes: The compensated laser output power is obtained by multiplying the initial laser output power by the power correction factor, and the current laser output power is adjusted to the compensated laser output power.

[0012] According to one embodiment of this application, determining the time correction factor based on the deviation between the actual value of the molten solder state coupling coefficient and the reference value of the molten solder state coupling coefficient, and / or the deviation between the actual value of the molten solder pad area coupling coefficient and the reference value of the molten solder pad area coupling coefficient, includes: Based on the deviation between the actual value of the coupling coefficient of the molten tin state and the reference value of the coupling coefficient of the molten tin state, the corresponding first time correction factor is determined according to the preset mapping relationship between the melting deviation and the time correction factor. Based on the deviation between the actual value of the solder spreading pad area coupling coefficient and the reference value of the solder spreading pad area coupling coefficient, the corresponding second time correction factor is determined according to the preset spreading deviation-time correction factor mapping relationship. The time correction factor is determined based on the first time correction factor and / or the second time correction factor.

[0013] According to one embodiment of this application, the time correction factor is greater than or equal to 0 and less than or equal to a third preset threshold.

[0014] According to one embodiment of this application, the compensation control of welding time based on the time correction factor includes: When the actual value of the coupling coefficient of the molten solder state is less than or equal to the reference value of the coupling coefficient of the molten solder state, and the actual value of the coupling coefficient of the molten solder pad area is less than or equal to the reference value of the coupling coefficient of the molten solder pad area, the laser output power after the first compensation is obtained based on the sum of the initial soldering time and the time correction factor, and the current laser output power is adjusted to the laser output power after the first compensation; wherein, the time correction factor is determined based on the first time correction factor and the second time correction factor; When the actual value of the coupling coefficient of the molten tin state is greater than the reference value of the coupling coefficient of the molten tin state, the second compensated laser output power is obtained based on the difference between the initial welding time and the time correction factor, and the current laser output power is adjusted to the second compensated laser output power; wherein, the time correction factor is determined based on the first time correction factor; When the actual value of the coupling coefficient of the solder pad area is greater than the reference value of the coupling coefficient of the solder pad area, the laser output power after the third compensation is obtained based on the difference between the initial soldering time and the time correction factor, and the current laser output power is adjusted to the laser output power after the third compensation; wherein, the time correction factor is determined based on the second time correction factor.

[0015] According to one embodiment of this application, obtaining the actual values ​​of process parameters during laser solder paste welding includes: During the laser soldering process, sampling is performed according to a preset sampling period to obtain the actual values ​​of the process parameters at the current sampling time; Before compensating for the laser output power and welding time based on the deviation between the actual values ​​of the process parameters and the preset reference values ​​of the process parameters, the method further includes: The actual value of the process parameter at the current sampling time is compared with the preset reference value of the process parameter at the corresponding sampling time to determine the deviation between the actual value of the process parameter and the preset reference value of the process parameter.

[0016] According to one embodiment of this application, the welding temperature is obtained by detecting the temperature value of the solder pad surface using a coaxial infrared temperature detection sensor in the laser head.

[0017] According to one embodiment of this application, the reference value of the coupling coefficient of the molten tin state is pre-calibrated in the following manner: Acquire images of the molten tin state at multiple consecutive sampling moments during the calibration experiment; The image of the molten tin in a molten state is input into a pre-trained visual detection model to obtain the baseline value of the coupling coefficient of the molten tin in a ... Based on the molten tin melting state images and the corresponding molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time, an association database of molten tin melting state images and molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time is established.

[0018] According to one embodiment of this application, the reference value of the solder melt spreading pad area coupling coefficient is pre-calibrated in the following manner: Acquire images of the solder pad area at multiple consecutive sampling times during the calibration experiment; The solder molten solder pad area status image is input into a pre-trained visual detection model to obtain the baseline value of the solder molten solder pad area coupling coefficient corresponding to the solder molten solder pad area status image. Based on the solder pad area status images at each continuous sampling time and the corresponding solder pad area coupling coefficient benchmark values, a correlation database is established between the solder pad area status images at each continuous sampling time and the solder pad area coupling coefficient benchmark values.

[0019] A laser soldering process control apparatus according to a second aspect embodiment of this application includes: The parameter acquisition module is used to acquire the actual values ​​of process parameters during laser solder paste soldering. The process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient. The solder melt state coupling coefficient is the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient is the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad. The compensation control module is used to compensate and control the laser output power and welding time based on the deviation between the actual value of the process parameters and the preset process parameter reference value.

[0020] An electronic device according to a third aspect of this application includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the laser soldering process control method as described above.

[0021] According to a fourth aspect of this application, a non-transitory computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the laser soldering process control method as described above.

[0022] A computer program product according to a fifth aspect of this application includes a computer program that, when executed by a processor, implements the laser soldering process control method as described above.

[0023] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects: By acquiring the coupling coefficients of welding temperature, molten solder state, and solder pad area in real time during laser soldering, and comparing these actual process parameter values ​​with their respective preset reference values, this method compensates for deviations in laser output power and welding time when any process parameter deviates from its reference value. This ensures that the actual values ​​of each process parameter approach the reference values ​​in real time, achieving dynamic closed-loop control of the laser soldering process. This improves the stability and consistency of welding quality and reduces the welding defect rate caused by fluctuations in process parameters. This application not only adjusts the laser output power in real time to correct temperature deviations but also dynamically adjusts the welding time based on the actual melting progress and spreading state of the solder paste, achieving multi-dimensional and high-precision welding quality control. This improves solder joint quality and increases the first-pass yield.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the laser soldering process in related technologies.

[0027] Figure 2 This is a schematic diagram of the generation of solder balls during the laser soldering process in related technologies.

[0028] Figure 3 This is one of the flowcharts of the laser soldering process control method provided in the embodiments of this application.

[0029] Figure 4 This is a schematic diagram illustrating the principle of laser solder paste welding process provided in the embodiments of this application.

[0030] Figure 5 This is the second flowchart of the laser soldering process control method provided in the embodiments of this application.

[0031] Figure 6 This is a schematic diagram of the multimodal monitoring curve provided in the embodiments of this application.

[0032] Figure 7 This is a schematic diagram of the molten solder state as the solder paste gradually changes from a solid to a liquid state, as provided in the embodiments of this application.

[0033] Figure 8 This is a schematic diagram of the initial spreading state of molten solder gradually spreading outward on the surface of the solder pad, as provided in the embodiments of this application.

[0034] Figure 9 This is a schematic diagram of the IMC layer state of the solder joint in the laser solder wire welding process provided in this application embodiment.

[0035] Figure 10 This is a schematic diagram of the IMC layer state of the solder joint in the laser solder paste welding process provided in the embodiments of this application.

[0036] Figure 11 This is a schematic diagram of the structure of the laser soldering process control device provided in the embodiments of this application.

[0037] Figure 12 This is a schematic diagram of the physical structure of the electronic device provided in the embodiments of this application.

[0038] Figure label: 110: Solder wire; 120: Laser; 210: Solder wire alloy; 220: Solder wire flux; 230: Solder ball; 410: Solder pad; 420: Solder paste; 430: Solder joint pin; 440: Solder tip; 450: Soldering laser beam; 460: Formed solder joint. Detailed Implementation

[0039] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0040] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0042] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Figure 1 This is a schematic diagram of the laser soldering process in related technologies. (Refer to...) Figure 1 The existing laser soldering process can include the following steps: (a) preparation of solder pads and connectors; (b) preparation of solder wire 110 and preheating of the solder pads by laser 120; (c) the initial stage of wire feeding + laser soldering: the solder wire initially contacts the solder pad, and the laser irradiates the local area to melt the solder wire; (d) the continuous stage of wire feeding + laser soldering: the solder wire is continuously fed in, and the molten solder gradually gathers on the solder pad and spreads outward; (e) wire return + laser soldering; (f) soldering completion.

[0045] Figure 2 This is a schematic diagram illustrating the formation of solder balls during the laser soldering process in related technologies. (Refer to...) Figure 2 Solder spatter mainly occurs during the wire feeding (contact with the pad) + laser soldering stage. The arrow indicates that the pad temperature is approximately 320℃ due to laser heating. The solder wire (i.e., solder wire alloy) contains approximately 2.1%-3.0% flux, composed of solvent (isopropanol) and activator (rosin), with a boiling point of approximately 70~120℃. The instant the solder wire alloy 210 contacts the pad, the solder wire flux 220 instantly reaches a boiling point temperature exceeding 200℃. The internal energy cannot be released instantly, causing flux and molten solder to splatter, producing solder balls 230.

[0046] Therefore, the following problems exist in the laser soldering process: (1) In the industry, the soldering of the PCB board pins of the internal motor of the equipment adopts the soldering process, mainly manual soldering and laser soldering. During the soldering process of the above two methods, the flux in the solder wire will expand and vaporize due to heat, resulting in solder spatter, which will produce solder dross and solder balls. Solder balls falling into the gap between the rotor and stator can easily cause serious quality problems such as abnormal motor noise or even motor jamming.

[0047] (2) In the current industry, the main method for monitoring the welding quality of laser soldering process is post-weld quality monitoring, which has poor timeliness. Furthermore, the real-time monitoring method during the welding process is very simple, mainly closed-loop control of welding temperature. This has a certain difference in correlation with the final quality of the solder joint, resulting in a low first-pass yield (about 95%), large fluctuations in solder joint quality, a huge amount of rework on the production line, and extremely high risks in the quality process.

[0048] To address the aforementioned issues, this application embodiment acquires the coupling coefficients of welding temperature, molten solder state, and molten solder pad area in real time during laser solder paste welding as actual values ​​of process parameters. These actual values ​​are then compared with their respective preset reference values. When any actual value of a process parameter deviates from its corresponding reference value, the laser output power and welding time are compensated and controlled according to the deviation, ensuring that the actual values ​​of each process parameter approach the reference value in real time. This achieves dynamic closed-loop control of the laser solder paste welding process, which helps improve the stability and consistency of welding quality and reduces the welding defect rate caused by fluctuations in process parameters.

[0049] Figure 3 This is one of the flowcharts illustrating the laser soldering process control method provided in this application. (Refer to...) Figure 3 This application provides a laser soldering process control method, which specifically includes the following steps: Step 301: Obtain the actual values ​​of process parameters during laser solder paste soldering. Process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient. The solder melt state coupling coefficient is the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient is the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad. Step 302: Based on the deviation between the actual value of the process parameters and the preset benchmark value of the process parameters, compensate and control the laser output power and welding time.

[0050] It should be noted that the embodiments of this application can be applied to laser solder paste welding process control in various electronic assembly scenarios. For example, in the production scenario of PCB (Printed Circuit Board) for air conditioner indoor unit motors, during the laser solder paste welding of various surface mount components on the PCB, the welding temperature and welding quality can be monitored in real time. By adjusting the laser output power and welding time in real time, the welding temperature and welding quality of the entire process can be adjusted in real time to ensure the quality of solder joint formation and improve the first-pass yield.

[0051] Laser solder paste soldering is a precision soldering process that uses a laser beam as a heat source to heat solder paste to a molten state to achieve electrical connections between electronic components and pads. During soldering, the laser output power affects the heating rate and peak temperature, while the soldering time affects the total heat input and the duration of holding above the liquidus line. Both factors jointly determine the melting behavior and spreading pattern of the solder paste. Insufficient laser output power or too short a soldering time may result in incomplete melting and spreading of the solder paste; excessively high laser output power or too long a soldering time may lead to solder splashing, overheating and peeling of pads, or bridging and short circuits between adjacent solder joints. Therefore, this embodiment of the application monitors process parameters such as soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient in real time during laser solder paste soldering. Based on the deviation between the actual process parameter values ​​and preset process parameter reference values, feedback compensation control is applied to the laser output power and soldering time, thereby ensuring the quality of solder joints in the laser solder paste soldering process.

[0052] It should be noted that the execution subject of the laser soldering process control method provided in this application embodiment can be laser soldering equipment, control components in laser soldering equipment, integrated circuits, or chips. The following embodiments of this application describe the laser soldering equipment as the execution subject.

[0053] The laser soldering process control method provided in this application can be applied to laser soldering equipment. The laser soldering equipment may include a laser generator, an optical transmission component, a temperature detection unit, a vision detection unit, and a controller. The laser generator generates a laser beam, the optical transmission component guides the laser beam to the area to be soldered, the temperature detection unit acquires the soldering temperature value of the soldering area in real time, the vision detection unit acquires image information of the solder pad area, and the controller receives the detection signal and performs process parameter control and compensation. The controller responds to the acquired actual values ​​of the process parameters and compares them with preset process parameter reference values. Based on the comparison result (i.e., the deviation), it generates a compensation control signal to adjust the laser output power of the laser generator and the soldering time.

[0054] In the embodiments of this application, the welding temperature refers to the real-time temperature value of the welding area (e.g., the surface of the solder paste / pad) during the laser soldering process.

[0055] In some embodiments, the soldering temperature can be obtained through a temperature detection unit, which may include an infrared temperature sensor or a thermocouple. An infrared temperature sensor can measure the surface temperature of the soldering area in a non-contact manner by receiving thermal radiation signals from the soldering area; a thermocouple can measure the temperature near the solder pad or component pin in a contact manner.

[0056] In some embodiments, the temperature detection unit can acquire the actual welding temperature value in real time according to a preset sampling period (e.g., once every 10 milliseconds) and transmit the actual welding temperature value to the controller.

[0057] In some embodiments, the soldering temperature reference value can be determined based on the alloy composition of the solder paste. For example, for SAC305 (tin-silver-copper) alloy solder paste, which has a melting point of approximately 217°C, the soldering temperature reference value can be set to a target value between 230°C and 250°C to ensure that the solder paste melts sufficiently without overheating.

[0058] In the embodiments of this application, the molten solder state coupling coefficient refers to the ratio of the mass of molten solder in the molten state to the total mass of solder paste, which is used to characterize the progress of the solder paste changing from solid to liquid state in the current laser solder paste welding process.

[0059] In some embodiments, a top camera in the vision inspection unit can be used to acquire images of the molten solder state in the soldering area. These images are then input into a pre-trained vision inspection model, which extracts image features such as the rate of change of the projected area of ​​the solder pads, grayscale gradient changes, and edge smoothness for detection. This yields the molten solder state coupling coefficient output by the vision inspection model. By utilizing the molten solder state coupling coefficient output by the vision inspection model, real-time visual quantitative perception of the solder paste melting progress is achieved, providing a reliable basis for dynamic compensation of soldering parameters and improving solder joint quality.

[0060] In other embodiments, three-dimensional point cloud data of molten solder (i.e., molten solder in a molten state) can be obtained, the volume of molten solder can be determined based on the three-dimensional point cloud data, and the mass of molten solder in a molten state can be determined based on the volume and density of molten solder. Then, the coupling coefficient of the molten state of solder can be determined by combining the pre-determined total mass of solder paste.

[0061] The total mass of solder paste can be the reference value set in the calibration experiment or the actual value of the total mass of solder paste measured in the actual process.

[0062] In the embodiments of this application, the solder spreading pad area coupling coefficient refers to the ratio of the area of ​​molten solder spreading on the pad surface to the total area of ​​the solderable area of ​​the pad, and is used to characterize the degree of wetting and spreading of molten solder on the pad surface.

[0063] In some embodiments, a top camera in the vision inspection unit can be used to acquire images of the solder molten metal spreading area of ​​the solder pads. These images are then input into a pre-trained vision inspection model. The model extracts image features such as the rate of change of the projected area of ​​the solder pads, grayscale gradient changes, and edge smoothness for detection, thereby obtaining the solder molten metal spreading area coupling coefficient output by the vision inspection model. By utilizing the solder molten metal spreading area coupling coefficient output by the vision inspection model, real-time visual quantization of the solder molten metal spreading area is achieved, providing spatial morphological feedback for soldering parameter compensation and improving the solder joint formation quality.

[0064] In other embodiments, for the solder paste area status image, feature pixels of the solder paste-covered area can be extracted through image binarization processing. The percentage of feature pixels in the solder paste-covered area relative to the total number of pixels in the pad area is calculated to obtain the solder paste area coupling coefficient. When the solder paste area coupling coefficient reaches a preset threshold (e.g., 80% to 95%), it indicates that the solder paste has sufficiently wetted the pad and the soldering quality is good. When the coefficient is lower than the preset threshold, it indicates that the solder paste is not sufficiently spread, and there may be problems with poor wetting or insufficient heat.

[0065] It should be noted that the coupling coefficient of the molten solder state and the coupling coefficient of the molten solder pad area can be extracted separately based on the same set of image information collected by the same vision detection unit, or they can be obtained separately based on different detection units.

[0066] In this embodiment, the process parameter reference values ​​may include soldering temperature reference values, solder melt state coupling coefficient reference values, and solder melt spreading pad area coupling coefficient reference values ​​corresponding to multiple consecutive sampling times. These process parameter reference values ​​can be pre-calibrated through calibration experiments. In practical applications, the process parameter reference values ​​can be adaptively adjusted based on specific solder paste type, solder quantity, pad size, and soldering requirements.

[0067] In this embodiment, the laser output power and welding time can be compensated and controlled based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters. Specifically, the temperature deviation between the actual value of the welding temperature and the reference value of the welding temperature, the melting deviation between the actual value of the molten solder state coupling coefficient and the reference value of the molten solder state coupling coefficient, and the spreading deviation between the actual value of the molten solder pad area coupling coefficient and the reference value of the molten solder pad area coupling coefficient can be calculated respectively. The output power of the laser generator (i.e., laser output power) can be adjusted according to the temperature deviation, and the irradiation duration of the laser beam (i.e., welding time) can be adjusted according to the melting deviation.

[0068] In some embodiments, when the actual value of the welding temperature indicated by the temperature deviation is lower than the reference value, the laser output power can be increased; when the actual value of the welding temperature indicated by the temperature deviation is higher than the reference value, the laser output power can be decreased. Similarly, when the actual value of the coupling coefficient of the molten solder state indicated by the melt deviation is lower than the reference value, and / or the actual value of the coupling coefficient of the molten solder pad area indicated by the spreading deviation is lower than the reference value, the welding time can be extended; when the actual value of the coupling coefficient of the molten solder state indicated by the melt deviation is higher than the reference value, and / or the actual value of the coupling coefficient of the molten solder pad area indicated by the spreading deviation is higher than the reference value, the welding time can be shortened. Through the above methods, a closed-loop feedback control is formed, so that the actual values ​​of each process parameter approach their respective reference values ​​in real time, thereby improving the solder joint quality of the laser solder paste welding process.

[0069] In some embodiments, when compensating and controlling the laser output power and welding time, power compensation can be prioritized, and time compensation can be performed only when the power compensation reaches the preset upper limit of the rated power of the laser generator. This can make full use of the dynamic adjustment range of the laser output power to quickly respond to temperature deviations, and avoid the laser output power being in the limit state for a long time, which may lead to equipment aging or overheating damage.

[0070] Specifically, when the temperature deviation exceeds the first threshold, the power compensation amount can be calculated based on the temperature deviation, and it can be determined whether the current laser output power, after adding the power compensation amount, exceeds the rated power limit of the laser generator. If it does not exceed the rated power limit, the laser output power can be adjusted according to the power compensation amount; if it exceeds the rated power limit, the laser output power can be adjusted to the rated power limit, and the time compensation amount can be calculated based on the remaining uncompensated deviation amount to extend the welding time.

[0071] Besides welding temperature, the molten solder state and the molten solder spreading area also reflect welding quality. Therefore, this embodiment monitors the molten solder state coupling coefficient (used to quantify the molten solder state) and the molten solder pad area coupling coefficient (used to quantify the molten solder spreading area), combined with welding temperature, to achieve multi-dimensional real-time quantitative monitoring of welding quality. This provides a reliable basis for closed-loop dynamic compensation of welding time and laser output power, and ensures zero solder breakage, zero solder balls, and zero board burn during the welding process, thereby guaranteeing solder joint quality and improving the first-pass yield.

[0072] Compared to laser solder wire soldering, this application embodiment uses laser solder paste soldering, which reduces the amount of solder used, and the solder joint slices and IMC layer conditions meet the process requirements.

[0073] This application embodiment acquires the coupling coefficients of welding temperature, molten solder state, and molten solder pad area in real time during laser solder paste welding as actual values ​​of process parameters. These actual values ​​are compared with their respective preset reference values. When any actual value deviates from its reference value, the laser output power and welding time are compensated based on the deviation, ensuring that the actual values ​​of each process parameter approach the reference values ​​in real time. This achieves dynamic closed-loop control of the laser solder paste welding process, which improves the stability and consistency of welding quality and reduces the welding defect rate caused by fluctuations in process parameters. This application not only adjusts the laser output power in real time to correct temperature deviations but also dynamically adjusts the welding time based on the actual melting progress and spreading state of the solder paste, achieving multi-dimensional and high-precision welding quality control, thereby improving solder joint quality and increasing the first-pass yield.

[0074] Based on any of the above embodiments, the laser output power and welding time are compensated and controlled based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters, including: Based on the deviation between the actual welding temperature and the reference welding temperature, a power correction factor is determined, and the laser output power is compensated and controlled based on the power correction factor. Based on the deviation between the actual value of the coupling coefficient of the molten solder state and the reference value of the coupling coefficient of the molten solder state, and / or the deviation between the actual value of the coupling coefficient of the molten solder pad area and the reference value of the coupling coefficient of the molten solder pad area, a time correction factor is determined, and the soldering time is compensated and controlled based on the time correction factor.

[0075] In this embodiment, the welding temperature can be used as the primary control variable for laser output power. A power correction factor is calculated based on the temperature deviation, allowing for real-time adjustment of the laser output power to achieve rapid response. Simultaneously, the coupling coefficient of the molten solder state and the coupling coefficient of the molten solder pad area can be used as direct characterizing variables for welding quality. A time correction factor is determined based on the melting deviation and / or spreading deviation to correct the welding time, thereby ensuring sufficient melting and complete spreading of the solder paste. This embodiment employs a dual closed-loop decoupled control strategy of welding temperature-laser output power and melting state-welding time to separately regulate the heat input intensity and total heat input during the laser soldering process.

[0076] In some embodiments, a mapping table between deviation and correction factor can be pre-established and stored in the controller's storage unit as a data table. The mapping table can contain multiple sets of discrete mapping nodes, each node recording a deviation value and its corresponding correction factor value. During real-time control, upon acquiring the current deviation, the controller can query this data table; if the current deviation is exactly equal to a node value, the correction factor corresponding to that node is directly read; if the current deviation lies between two adjacent node values, the corresponding correction factor is calculated using linear interpolation or the nearest neighbor method to ensure continuous and smooth output of the correction factor. The correction factor and the absolute value of the deviation can be positively correlated, meaning the larger the absolute value of the deviation, the larger the absolute value of the correction factor, thus achieving rapid deviation correction.

[0077] The embodiments of this application employ a dual closed-loop decoupling compensation system that adjusts laser output power based on temperature deviation and welding time based on melting and spreading deviations. This system can accurately match the actual energy requirements under different working conditions, avoiding insufficient melting or poor spreading that may occur when relying solely on temperature control, and preventing solder joint defects caused by over-melting. This improves the adaptability of the laser soldering process and the consistency of solder joint forming quality.

[0078] Based on any of the above embodiments, a power correction factor is determined based on the deviation between the actual welding temperature value and the welding temperature reference value, including: Based on the deviation between the actual welding temperature and the welding temperature reference value, the corresponding power correction factor is determined according to the preset temperature deviation-power correction factor mapping relationship.

[0079] In this embodiment, welding temperature is used as a state variable characterizing the intensity of heat input. By calculating the deviation between the actual temperature value and the reference value in real time, and by using the preset temperature deviation-power correction factor mapping relationship for querying or interpolation calculation, the corresponding power correction factor can be output. Thus, the output power of the laser generator can be adjusted based on the power correction factor, which can achieve rapid and accurate correction of temperature deviation.

[0080] In some embodiments, the temperature deviation-power correction factor mapping relationship can be stored through a mapping table, a linear function, or a PID (Proportional-Integral-Derivative) coefficient table.

[0081] In some embodiments, in the temperature deviation-power correction factor mapping relationship, the larger the temperature deviation, the larger the power correction factor can be, which can realize temperature deviation-sensitive adaptive power compensation, rapid temperature recovery when there is a large deviation, and fine adjustment when there is a small deviation, thereby significantly shortening the temperature control response time and suppressing overshoot, and improving the dynamic response capability and steady-state accuracy of laser soldering temperature control.

[0082] In some embodiments, in the temperature deviation-power correction factor mapping relationship, multiple threshold intervals can be set, each threshold interval having its own corresponding power correction factor, thereby determining the power correction factor corresponding to the threshold interval where the temperature deviation is located as the power correction factor corresponding to the temperature deviation.

[0083] This application embodiment determines the power correction factor corresponding to the deviation between the actual welding temperature and the welding temperature reference value according to a preset temperature deviation-power correction factor mapping relationship. This provides a clear quantitative basis for power compensation, avoiding over-compensation or under-compensation problems caused by relying on manual experience or fixed increment adjustment. At the same time, the use of preset mapping relationship for table lookup or interpolation calculations results in fast response speed and low computational overhead, which can meet the real-time compensation requirements when the temperature fluctuates rapidly during the laser soldering process. This improves the stability of welding temperature control and ensures the welding quality of the laser soldering process.

[0084] Based on any of the above embodiments, when the actual welding temperature is less than the welding temperature reference value, the power correction factor is greater than 1 and less than or equal to the first preset threshold; when the actual welding temperature is greater than the welding temperature reference value, the power correction factor is greater than or equal to the second preset threshold and less than 1; when the actual welding temperature is equal to the welding temperature reference value, the power correction factor is 1.

[0085] In this embodiment, the power correction factor can be divided into three value ranges based on the relative magnitude of the actual welding temperature and the welding temperature reference value: when the actual value is lower than the reference value, the power correction factor is between 1 and the first preset threshold (greater than 1) to achieve positive incremental compensation of laser output power; when the actual value is higher than the reference value, the power correction factor is between the second preset threshold and 1 (less than 1) to achieve reverse reduction compensation of laser output power; when the actual value is equal to the reference value, the power correction factor is 1 to maintain the current laser output power unchanged.

[0086] In some embodiments, the first preset threshold can be determined based on the ratio of the rated power limit of the laser generator to the initial laser output power, thereby ensuring that the power compensation does not exceed the safe operating range of the equipment. For example, the first preset threshold can be 1.2.

[0087] In some embodiments, the second preset threshold can be determined based on the ratio of the minimum heat input power required to maintain the solder paste in a molten state to the initial laser output power, thereby preventing the soldering temperature from dropping below the solidus line due to excessively low laser output power. For example, the second preset threshold can be 0.9.

[0088] In some embodiments, when the deviation between the actual welding temperature and the reference welding temperature is within a preset temperature deviation range, the power correction factor can be kept at 1, and no power adjustment is performed. This effectively avoids frequent jumps in the power correction factor caused by temperature measurement noise, prevents jitter in the laser output power, and improves the system's anti-interference capability and the stability of the welding process. For example, the preset temperature deviation range can be ±2℃.

[0089] This application embodiment effectively avoids the problem of power overcompensation caused by extreme deviations by setting clear upper and lower boundaries for the power correction factor. It ensures sufficient compensation capability to quickly eliminate temperature difference when there is a large deviation, and prevents temperature overshoot or system oscillation caused by the power correction factor being too large or too small. This improves the dynamic response stability and control accuracy of laser soldering temperature control and enhances the soldering quality.

[0090] Based on any of the above embodiments, compensating and controlling the laser output power based on a power correction factor includes: The compensated laser output power is obtained by multiplying the initial laser output power by the power correction factor, and the current laser output power is adjusted to the compensated laser output power.

[0091] In some embodiments, during the process of adjusting the current laser output power to the compensated laser output power, a gradual adjustment can be performed using a step-by-step or ramp function approach, rather than a direct jump. Specifically, the compensated laser output power can be gradually approximated with a preset step size (e.g., each adjustment does not exceed 5% of the current power), thereby preventing thermal shock or molten solder splashing caused by sudden power changes.

[0092] In some embodiments, after the current power compensation adjustment is completed, the compensated laser output power can be used as the initial laser output power value for the next control cycle for iteration. That is, the compensated laser output power of the previous moment becomes the initial laser output power of the next moment, forming a recursive power update mechanism, thereby ensuring that the power can continuously advance towards the target direction under continuous deviation, and achieving gradual convergence of welding temperature.

[0093] Based on any of the above embodiments, a time correction factor is determined based on the deviation between the actual value of the solder melt state coupling coefficient and the reference value of the solder melt state coupling coefficient, and / or the deviation between the actual value of the solder melt spreading pad area coupling coefficient and the reference value of the solder melt spreading pad area coupling coefficient, including: Based on the deviation between the actual value of the coupling coefficient of the molten tin state and the reference value of the coupling coefficient of the molten tin state, the corresponding first time correction factor is determined according to the preset mapping relationship between the melting deviation and the time correction factor. Based on the deviation between the actual value of the solder spreading pad area coupling coefficient and the reference value of the solder spreading pad area coupling coefficient, the corresponding second time correction factor is determined according to the preset spreading deviation-time correction factor mapping relationship. The time correction factor is determined based on the first time correction factor and / or the second time correction factor.

[0094] In this embodiment, the coupling coefficient of the molten tin state and the coupling coefficient of the molten tin spreading pad area are used as two dimensions representing the soldering quality. Each is compared with the corresponding benchmark value to obtain the deviation. The first time correction factor (based on the melting progress) and the second time correction factor (based on the spreading degree) are calculated by their respective preset mapping relationships. The final time correction factor is then determined by combining the first time correction factor and / or the second time correction factor.

[0095] In some embodiments, a preset melting deviation-time correction factor mapping relationship can be stored through a mapping table, a linear function, or a PID coefficient table.

[0096] In some embodiments, a preset mapping relationship between spreading deviation and time correction factor can be stored through a mapping table, a linear function, or a PID coefficient table.

[0097] It should be noted that the specific methods for determining the corresponding first time correction factor based on the preset melting deviation amount-time correction factor mapping relationship in this application embodiment, and the specific methods for determining the corresponding second time correction factor based on the preset spreading deviation amount-time correction factor mapping relationship, are similar to the specific methods for determining the corresponding power correction factor based on the preset temperature deviation amount-power correction factor mapping relationship described above, and will not be repeated here.

[0098] In some embodiments, the first time correction factor and the second time correction factor can be fused by weighted summation, taking the maximum value, taking the average value, or logical priority selection, so as to unify the welding quality information of the two dimensions of whether the melting is sufficient and whether the spreading is complete into a single control quantity of welding time, and realize time compensation control driven by multiple quality indicators.

[0099] This application's embodiments introduce two independent coupling coefficients as the basis for adjusting soldering time. This ensures that soldering time compensation does not solely rely on temperature or a single physical quantity, but comprehensively reflects the phase transition completion and wetting / spreading quality of the solder paste. This overcomes the control blind spot in traditional methods where temperature meets the standard but melting / spreading is poor. The first and second time correction factors reflect the deviation requirements of different soldering quality dimensions. Time compensation is triggered when any dimension is abnormal, and the two factors work synergistically to enhance the laser soldering process's overall adaptability to various interferences such as solder paste volume fluctuations, pad oxidation, and flux activity differences. This ensures that the solder joint simultaneously meets the requirements of sufficient melting and complete spreading in terms of total heat input, thereby improving soldering quality.

[0100] Based on any of the above embodiments, the time correction factor is greater than or equal to 0 and less than or equal to a third preset threshold.

[0101] In some embodiments, the third preset threshold may be set to 0.5.

[0102] In some embodiments, the third preset threshold can be dynamically adjusted according to the characteristics of different soldering stages. For example, in the soldering preheating stage (when the solder paste just begins to melt), a smaller third preset threshold can be set to prevent over-melting; in the soldering stage (when it has fully melted but spreads slowly), the third preset threshold can be appropriately increased to allow sufficient spreading time; in the heat preservation stage, the third preset threshold can be appropriately reduced, thereby achieving the differentiated requirements of time compensation range for different process stages.

[0103] This application embodiment, by setting a range of values ​​for the time correction factor, can avoid the risk of overheating and burning caused by the welding time being compensated to a negative value or increasing indefinitely due to sensor noise, model prediction errors, or extreme working conditions. This achieves safety assurance and process stability of time compensation control, which is beneficial to improving the welding quality of laser soldering.

[0104] Based on any of the above embodiments, compensating for and controlling the welding time based on a time correction factor includes: When the actual value of the coupling coefficient of the molten solder state is less than or equal to the reference value of the coupling coefficient of the molten solder state, and the actual value of the coupling coefficient of the molten solder pad area is less than or equal to the reference value of the coupling coefficient of the molten solder pad area, the laser output power after the first compensation is obtained based on the sum of the initial welding time and the time correction factor, and the current laser output power is adjusted to the laser output power after the first compensation; wherein, the time correction factor is determined based on the first time correction factor and the second time correction factor; When the actual value of the coupling coefficient of the molten tin state is greater than the reference value of the coupling coefficient of the molten tin state, the second compensated laser output power is obtained based on the difference between the initial welding time and the time correction factor, and the current laser output power is adjusted to the second compensated laser output power; wherein, the time correction factor is determined based on the first time correction factor; When the actual value of the coupling coefficient of the solder pad area is greater than the reference value of the coupling coefficient of the solder pad area, the laser output power after the third compensation is obtained based on the difference between the initial soldering time and the time correction factor, and the current laser output power is adjusted to the laser output power after the third compensation; wherein, the time correction factor is determined based on the second time correction factor.

[0105] In this embodiment, the molten state coupling coefficient and the spreading area coupling coefficient are used as dual dimensions of soldering quality. Based on the comparison of their actual values ​​with their respective reference values, time compensation is divided into three modes: When the actual value of the molten state coupling coefficient is less than or equal to the reference value of the molten state coupling coefficient, and the actual value of the molten solder spreading pad area coupling coefficient is less than or equal to the reference value of the molten solder spreading pad area coupling coefficient (i.e., insufficient melting and insufficient spreading), it indicates that the total heat input is insufficient. Additive compensation (initial soldering time + time correction factor) can be used to extend the soldering time. Simultaneously, it compensates for deficiencies in melting and spreading. When the actual value of the coupling coefficient of the molten solder state is greater than the reference value (i.e., sufficient melting but insufficient spreading), subtractive compensation (initial soldering time - first time correction factor) can be used to shorten the soldering time and prevent the molten solder from over-melting due to excessive time. When the actual value of the coupling coefficient of the solder spreading pad area is greater than the reference value (i.e., insufficient melting but sufficient spreading), subtractive compensation is also used to shorten the soldering time and avoid bridging or oxidation of the fully spread solder due to overheating. The time compensation strategy of this application achieves differentiation and precision in the direction of time compensation.

[0106] In some embodiments, when contradictory conditions occur simultaneously, such as the actual value of the molten solder state coupling coefficient being greater than the reference value (over-melting) and the molten solder pad area coupling coefficient being less than the reference value (insufficient spreading), the compensation direction can be determined according to preset priority rules. For example, insufficient spreading can be prioritized as the criterion for additive compensation, because insufficient spreading means poor pad wettability, requiring more time to promote spreading. Even if there is a risk of over-melting, it can be adjusted collaboratively through power compensation.

[0107] In some embodiments, if the actual value of the coupling coefficient of the molten solder state is greater than the reference value of the coupling coefficient of the molten solder state, and the actual value of the coupling coefficient of the molten solder spreading pad area is greater than the reference value of the coupling coefficient of the molten solder spreading pad area, it indicates that the melting and spreading are sufficient, but there may be problems with overheating or excessive solder. At this time, the abnormal operating condition protection mode can be entered, the soldering time is reset to zero and the laser output is stopped, and a warning signal is triggered to ensure the safety of the process production.

[0108] This application embodiment achieves selective and directional adjustment of welding time by comparing the actual values ​​of the molten state coupling coefficient and the spreading area coupling coefficient with their respective reference values, triggering either additive or subtractive compensation. This allows for precise matching of heat input requirements under different defect modes, effectively improving the welding qualification rate and product consistency of the laser soldering process, and enhancing welding quality.

[0109] Based on any of the above embodiments, obtaining the actual values ​​of process parameters during laser soldering includes: During the laser soldering process, sampling is performed according to a preset sampling period to obtain the actual values ​​of the process parameters at the current sampling time; Before compensating for the deviation between the actual values ​​of the process parameters and the preset reference values ​​of the process parameters, the following steps are also included: The actual value of the process parameter at the current sampling time is compared with the preset reference value of the process parameter at the corresponding sampling time to determine the deviation between the actual value of the process parameter and the preset reference value of the process parameter.

[0110] This application introduces a periodic discrete sampling mechanism during laser solder paste soldering. The actual values ​​of process parameters (including soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient) are collected periodically according to a preset sampling period (e.g., every 50 milliseconds or every 100 milliseconds). The actual values ​​of process parameters at the current sampling time are synchronously compared with the preset process parameter reference values ​​at the corresponding sampling time stored in the database. This determines the deviation of each process parameter's actual value relative to the reference value at the sampling time. The deviation is used as the input basis for subsequent power compensation and time compensation to drive the execution of closed-loop feedback control.

[0111] In some embodiments, after obtaining the actual value of the process parameter at the current sampling time and before calculating the deviation, median filtering or moving average filtering can be performed on the actual value of the process parameter to suppress the influence of sensor noise and instantaneous interference on the deviation calculation. At the same time, the data validity of the filtered actual value of the process parameter can be verified. When the actual value exceeds the preset reasonable range, it is determined to be invalid data, the sampling value is discarded, and the deviation at the previous time is kept unchanged to prevent false compensation caused by sensor failure or communication abnormality.

[0112] In some embodiments, a process parameter baseline curve can be pre-determined through calibration experiments based on process information such as specific solder paste products, solder volume, and pad size. The process parameter baseline curve can be used to record the baseline values ​​of each process parameter at each sampling moment along the entire timeline of the laser soldering process from start to finish, thereby providing a clear, time-varying baseline value comparison reference for the actual values ​​of process parameters at each sampling moment in the dynamic process.

[0113] Specifically, multiple laser solder paste soldering tests can be performed under standard operating conditions (such as standard solder paste quality, standard ambient temperature, etc.), and the process parameter values ​​corresponding to the optimal soldering quality at each time point can be recorded. After smoothing, these values ​​can be stored as a process parameter reference curve.

[0114] In some embodiments, when the current sampling time is not perfectly aligned with the discrete node time in the process parameter reference curve (e.g., due to the drift of the controller clock causing the sampling time to shift), the process parameter reference value corresponding to the current sampling time can be calculated from the process parameter reference curve using linear interpolation or the nearest neighbor method. This ensures the continuous availability of the comparison reference and avoids the inability to calculate the deviation due to the missing reference value caused by the sampling time shift.

[0115] This application embodiment compares the actual value of the process parameters at each sampling moment with the corresponding reference value in real time, and uses the deviation for compensation control at the next moment, thereby realizing the gradual correction of process parameters in the laser soldering process and improving the soldering quality.

[0116] Based on any of the above embodiments, the welding temperature is obtained by detecting the temperature value of the solder pad surface using a coaxial infrared temperature detection sensor in the laser head.

[0117] In some embodiments, after laser soldering begins, Gaussian laser energy can be output to the pads, pins, and solder paste using a semiconductor large-spot laser. The spot diameter is adjustable (400μm-3mm). After the soldering object is heated, the surface temperature rises rapidly. The temperature value of the solder paste / pad surface is transmitted to the host database in real time by a coaxial infrared temperature detection sensor with a temperature measurement frequency of up to 1ms. The temperature detection range is 100-150℃, and the detection accuracy is ±5℃. After data acquisition, the numerical acquisition of the soldering temperature is completed.

[0118] This application embodiment uses a coaxial infrared temperature detection sensor in the laser head to detect the temperature value of the solder paste / pad surface in real time, realizing non-contact, delay-free, and field-of-view matching accurate temperature sensing. This provides a real-time, accurate, and coaxial feedback signal source for closed-loop compensation control of the soldering temperature, thereby ensuring the timeliness and accuracy of temperature control and helping to guarantee soldering quality.

[0119] Based on any of the above embodiments, the reference value of the coupling coefficient of the molten tin state is pre-calibrated in the following manner: Acquire images of the molten tin state at multiple consecutive sampling moments during the calibration experiment; Input the image of the molten tin state into a pre-trained visual detection model to obtain the baseline value of the coupling coefficient of the molten tin state corresponding to the image of the molten tin state. Based on the molten tin melting state images and the corresponding molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time, an association database of molten tin melting state images and molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time is established.

[0120] In this embodiment, images of the molten solder state at multiple consecutive sampling moments during laser soldering can be obtained through calibration experiments. A pre-trained visual detection model is used to infer the relationship between each frame of the image and output the baseline value of the molten solder state coupling coefficient corresponding to each sampling moment. This allows for the pairing and association of the molten solder state images and the baseline values ​​of the molten solder state coupling coefficient using time as an index, constructing a dynamically changing database of molten solder state images and baseline values ​​of the molten solder state coupling coefficient. This database can be used to record the curve of molten solder state images and melting progress baseline values ​​changing over time, providing a reference baseline value (i.e., the baseline value of the molten solder state coupling coefficient) for the melting progress that should be achieved at each sampling moment during subsequent real-time soldering.

[0121] In some embodiments, the standard molten solder state can be calibrated and periodically monitored using a coaxial camera in the laser head. During the calibration process, images of the molten solder state of a specific soldering object can be captured based on process information such as the specific product, solder quantity, and pad size. The main difference in the molten solder state is the proportion of solder paste that transforms into molten solder. The expected proportion can be used as the benchmark value for the molten solder coupling coefficient, and a related coupling coefficient correlation database can be established simultaneously to facilitate the quantitative correlation between process monitoring images (i.e., molten solder state images at each continuous sampling time) and the coupling coefficient.

[0122] This application embodiment constructs an association database of molten tin melting state images and molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time. This ensures that the benchmark value of the molten tin melting state coupling coefficient is not a single fixed value, but a dynamic benchmark curve bound to the welding process time axis. That is, each sampling time has a corresponding benchmark value, which can accurately reflect the melting progress corresponding to the optimal welding quality at that moment in the calibration experiment. This provides a reference for the deviation calculation in real-time process control with accurate time dimension alignment, avoiding the miscompensation problem caused by benchmark mismatch in different welding stages (initial melting stage, full melting stage, spreading stage) when using a single fixed benchmark value. This improves the stage adaptability and judgment accuracy of welding time closed-loop control, thereby improving welding quality.

[0123] Based on any of the above embodiments, the reference value of the solder paste area coupling coefficient is pre-calibrated in the following manner: Acquire images of the solder pad area at multiple consecutive sampling times during the calibration experiment; Input the solder molten metal spreading pad area status image into the pre-trained visual detection model to obtain the baseline value of the solder molten metal spreading pad area coupling coefficient corresponding to the solder molten metal spreading pad area status image. Based on the solder pad area status images at each continuous sampling time and the corresponding solder pad area coupling coefficient benchmark values, a correlation database is established between the solder pad area status images at each continuous sampling time and the solder pad area coupling coefficient benchmark values.

[0124] In this embodiment, the solder pad area status images at multiple consecutive sampling moments during the soldering process can be obtained through calibration experiments. A pre-trained visual detection model is used to infer the relationship between each frame of the image and output the baseline value of the solder pad area coupling coefficient corresponding to each sampling moment. This allows for the pairing and association of the solder pad area status images and the baseline values ​​of the solder pad area coupling coefficient with the sampling moment as an index, constructing a dynamically changing database of solder pad area status images and baseline values ​​of the solder pad area coupling coefficient. This database can be used to record the dynamic baseline curve of the solder pad area coupling coefficient changing with soldering time under standard process conditions, providing a time-varying reference baseline value for the actual value of the solder pad area coupling coefficient at that sampling moment in real-time soldering control.

[0125] In some embodiments, the standard solder pad area can be calibrated and periodically monitored using a coaxial camera in the laser head. During calibration, images of the solder pad area status for a specific soldering object can be captured based on process information such as the specific product, solder quantity, and pad size. The main difference in the area status is the solder pad spreading rate. The expected percentage can be used as the benchmark value for the solder pad area coupling coefficient, and a related coupling coefficient correlation database can be established simultaneously to facilitate the quantitative correlation between process monitoring images (i.e., solder pad area status images at each continuous sampling time) and the coupling coefficient.

[0126] This application embodiment constructs an association database of solder pad area status images and solder pad area coupling coefficient benchmark values ​​at each continuous sampling time. This makes the benchmark value of the solder pad area coupling coefficient no longer a single fixed threshold, but a dynamic benchmark curve bound to the welding process time axis. That is, each sampling time has a corresponding benchmark value, which can accurately reflect the spreading progress corresponding to the optimal welding quality at that moment in the calibration experiment. This provides a reference for the deviation calculation in real-time process control with accurate time dimension alignment, avoiding the miscompensation problem caused by benchmark mismatch in different spreading stages (preset stage, welding stage, heat preservation stage) when using a single fixed benchmark value. This improves the stage adaptability and judgment accuracy of closed-loop control in the entire spreading process, thereby improving the welding quality.

[0127] To enable those skilled in the art to better understand the embodiments of this application, the following specific embodiment will be used to illustrate this application.

[0128] Currently, the soldering of PCB board pins for air conditioner indoor unit motors in the industry uses soldering technology, mainly in two ways: manual soldering and laser soldering. During the soldering process of these two methods, the flux in the solder wire expands and vaporizes when heated, causing solder spatter, which produces solder dross and solder balls. Solder balls falling into the gap between the rotor and stator can easily cause serious quality problems such as abnormal motor noise or even motor seizure.

[0129] Furthermore, the current industry standard for laser soldering process mainly relies on post-soldering quality monitoring, which has poor timeliness. In addition, the real-time monitoring methods during the welding process are very limited, mainly relying on closed-loop control of welding temperature. This has a certain degree of correlation with the final quality of the solder joint, resulting in a low first-pass yield rate (around 95%), large fluctuations in solder joint quality, a huge amount of rework on the production line, and extremely high risks in the quality process.

[0130] To address the aforementioned issues, this application's embodiments use solder paste as the solder material. The solder paste is uniformly heated by a laser, and under the action of the laser heat source, it is preheated, melted, spread, and solidified. The laser solder paste welding process uses a multi-dimensional real-time closed-loop welding control model. By establishing the relationship between solder joint temperature, melting state, solder liquid spreading area, and welding quality, quantitative coupling is achieved. Furthermore, by measuring the deviation between the actual value and the reference value of the coupling coefficient, energy power and welding time compensation control are applied to the welding process, making the laser solder paste welding process smoother and more efficient, achieving zero spatter and zero board burning welding.

[0131] Figure 4 This is a schematic diagram illustrating the principle of laser solder paste welding process provided in the embodiments of this application. (Refer to...) Figure 4 Laser soldering can include the following steps: Step 1: Apply solder paste. See below. Figure 4 In (a), a preset amount of solder paste 420 is applied to the pad 410, and the solder joint pin 430 to be soldered is placed in the solder paste 420. At the same time, the solder tip 440 is prepared to complete the material preparation before soldering. Step 2: Laser soldering with solder paste. See also... Figure 4 In (b), the soldering laser beam 450 is irradiated onto the solder paste area, and the laser thermal energy is used to heat the solder paste 420 to melt it. The molten solder spreads on the surface of the pad and wets the pins of the solder joint 430, thus achieving electrical connection. Step 3: Solder joints cool and solidify. See also Figure 4 In step (c), laser heating is stopped, and the molten solder solidifies under natural or forced cooling conditions, forming a complete shaped solder joint 460 on the pad 410.

[0132] Figure 5 This is the second schematic flowchart of the laser soldering process control method provided in the embodiments of this application. (Refer to...) Figure 5The laser soldering process provided in this application can be divided into three stages: preheating, soldering, and heat preservation. After the soldering program is started, the input quantities are time T and power P. During the soldering process, the monitored variable values ​​(temperature, melt fitting amount, and spreading area) are compared with the set reference values ​​(obtained from the multimodal monitoring curve) in real time, and the correction factor of time T is obtained based on the multidimensional real-time closed-loop soldering control model function. Correction factor for power P The monitoring segment values ​​can be set based on the actual welding conditions. Finally, the correction factors for time T and power P are applied. , The input is fed into the welding program to achieve closed-loop control of time and power, and the control quantity is directly related to the welding quality.

[0133] Figure 6 This is a schematic diagram of the multimodal monitoring curve provided in an embodiment of this application. (Refer to...) Figure 6 Multimodal monitoring curves can be used to record the trends of welding temperature W, spreading area M (i.e., the coupling coefficient of the molten solder state) and melting fitting amount (i.e., the coupling coefficient of the molten solder pad area, whose variation curve is similar to that of the spreading area, but not shown in the figure) with welding time T at various stages of the laser soldering process (including the preheating stage, the soldering stage, and the heat preservation stage).

[0134] The multi-dimensional real-time closed-loop welding control quantity model and logic can be as follows: ; in, For welding control quantity model, The initial laser output power for welding, The compensated laser output power for welding; The initial welding time. The welding time is the compensated time after welding. This is the initial welding temperature reference value (or setting value). The actual value of the coaxial temperature monitoring during the welding process (i.e., the actual value of the welding temperature). The reference value for the coupling coefficient in the molten tin state. This represents the actual value of the coupling coefficient in the molten tin state. The baseline value for the coupling coefficient of the solder paste area is used as the solder melt spreading pad area. The actual value of the coupling coefficient for the solder pad area where the molten solder is spread; This is the temperature coupling compensation coefficient (i.e., the power correction factor). This is the coupling compensation coefficient for melt volume and spreading area (i.e., the time correction factor).

[0135] Among them, welding temperature Monitoring and data acquisition are performed as follows: After soldering begins, a semiconductor large-spot laser outputs Gaussian laser energy to the pads, pins, and solder paste. The spot diameter is adjustable (400μm-3mm). As the surface temperature of the soldering object rapidly increases after heating, a coaxial infrared temperature sensor with a measurement frequency of up to 1ms transmits the real-time temperature value of the solder paste / pad surface to the host database. The temperature detection range is 100-500℃, with a detection accuracy of ±5℃. Data acquisition is then completed. Numerical data collection for variables.

[0136] Among them, the coupling coefficient of the molten tin state Monitoring is conducted through the following methods: First, the standard molten solder state is calibrated and periodically monitored using a coaxial camera in the laser head. The specific calibration method involves capturing images of the molten solder state of a specific soldering object based on process information such as the specific product, solder quantity, and pad size. The main difference in the molten solder state is the proportion of solder paste transforming into molten solder. The expected proportion (e.g., 100% ± 10%) is used as the baseline value for the coupling coefficient of the molten solder state. Simultaneously, a related coupling coefficient comparison database is established to facilitate the quantitative correlation between process monitoring images and coupling coefficients.

[0137] Figure 7 This is a schematic diagram illustrating the molten solder state as the solder paste gradually transitions from a solid to a liquid state, as provided in the embodiments of this application. (Refer to...) Figure 7 Figures (a) to (e) sequentially show the melting process of solder paste as it gradually transforms from a solid to a liquid state under laser heating. The solder paste gradually collapses, its edges become rounded, and it eventually reaches a completely melted state as shown in Figure (e).

[0138] Among them, the coupling coefficient of solder paste pad area Monitoring is conducted through the following methods: First, the standard solder paste spreading pad area is calibrated and periodically monitored using a coaxial camera in the laser head. The specific calibration method is as follows: Based on process information such as the specific product, solder quantity, and pad size, images of the solder paste spreading pad area status of the specific soldering object are captured. The main difference in the spreading area status is the solder paste spreading rate of the pads. The expected percentage (e.g., 100% ± 5%) is used as the benchmark value for the solder paste spreading pad area coupling coefficient. Simultaneously, a relevant coupling coefficient comparison database is established to facilitate the quantitative correlation between process monitoring images and coupling coefficients.

[0139] Figure 8 This is a schematic diagram illustrating the initial spreading state of molten solder gradually expanding outwards from the surface of the solder pad, as provided in an embodiment of this application. (Refer to...) Figure 8Figures (a) to (d) sequentially show the spreading process of molten solder on the surface of the pad from initial wetting to gradual outward expansion. This is characterized by a gradual increase in the coverage area of ​​the solder and a more uniform edge contour, eventually reaching the expected spreading state with Figure (d) as the reference image.

[0140] Figure 9 This is a schematic diagram of the IMC layer state of the solder joint in the laser solder wire welding process provided in this application embodiment. Figure 10 This is a schematic diagram of the IMC layer state of the solder joint in the laser solder paste welding process provided in this application embodiment. Figure 9 and Figure 10 Comparison shows that the U-phase solder joints obtained using the laser solder paste welding process provided in this application have no abnormalities, the maximum bubble size of the V-phase solder joint is 130.33 μm (red arrows indicate bubble positions), and the maximum bubble size of the W-phase solder joint is 217.5 μm (red arrows indicate bubble positions). Furthermore, the growth of the U-phase IMC layer, V-phase IMC layer, and W-phase IMC layer is normal (the light gray area is the solder layer, i.e., the solder paste that melts and solidifies after laser soldering; the transition thin layer indicated by the red arrow is the IMC layer; the continuous and uniform thickness of the IMC layer indicates that the growth of the IMC layer is normal; the orange-yellow area is the copper pad on the PCB board). In other words, the solder joint slices and IMC layer states obtained using the laser solder paste welding process provided in this application meet the process requirements.

[0141] The embodiments of this application have the following technical effects: (1) The welding process achieves zero solder blasting, zero solder balls, and zero board burning. The welding process is simplified by more than 30%, the first-time defect rate of solder joints is reduced by more than 90%, and the first-time welding qualification rate exceeds 99.4%.

[0142] (2) Compared with the original mass production laser solder wire welding process, the amount of solder used in the laser solder paste welding process is reduced by 44% (from 0.127g per point to 0.07g), and the solder joint slice and IMC layer state both meet the process technology requirements.

[0143] Figure 11 This is a schematic diagram of the laser soldering process control device provided in an embodiment of this application. (Refer to...) Figure 11 This application provides a laser soldering process control device, which may specifically include the following modules: The parameter acquisition module 1110 is used to acquire the actual values ​​of process parameters during the laser solder paste welding process. The process parameters include welding temperature, solder melt molten state coupling coefficient, and solder melt spreading pad area coupling coefficient. The solder melt molten state coupling coefficient is the ratio of the mass of the molten solder in the molten state to the total mass of the solder paste. The solder melt spreading pad area coupling coefficient is the ratio of the area of ​​the molten solder in the molten state spreading on the pad surface to the total area of ​​the solderable area of ​​the pad. The compensation control module 1120 is used to compensate and control the laser output power and welding time based on the deviation between the actual value of the process parameters and the preset process parameter reference value.

[0144] This application embodiment acquires the coupling coefficients of welding temperature, molten solder state, and molten solder pad area in real time during laser solder paste welding as actual values ​​of process parameters. These actual values ​​are compared with their respective preset reference values. When any actual value deviates from its reference value, the laser output power and welding time are compensated based on the deviation, ensuring that the actual values ​​of each process parameter approach the reference values ​​in real time. This achieves dynamic closed-loop control of the laser solder paste welding process, which improves the stability and consistency of welding quality and reduces the welding defect rate caused by fluctuations in process parameters. This application not only adjusts the laser output power in real time to correct temperature deviations but also dynamically adjusts the welding time based on the actual melting progress and spreading state of the solder paste, achieving multi-dimensional and high-precision welding quality control, thereby improving solder joint quality and increasing the first-pass yield.

[0145] Based on the same idea as the method in the above embodiments, the laser soldering process control device provided in this application can implement the method in the above embodiments. For ease of explanation, the structural schematic diagram of the device embodiment only shows the parts related to the embodiments of this application. Those skilled in the art can understand that the illustrated structure does not constitute a limitation on the device, and may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0146] Figure 12 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 12 As shown, the electronic device may include: a processor 1210, a communication interface 1220, a memory 1230, and a communication bus 1240, wherein the processor 1210, the communication interface 1220, and the memory 1230 communicate with each other through the communication bus 1240. The processor 1210 can call the logic instructions in the memory 1230 to execute the following methods: obtaining the actual values ​​of process parameters during the laser solder paste soldering process; the process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt state coupling coefficient refers to the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad; and compensating for the laser output power and soldering time based on the deviation between the actual values ​​of the process parameters and the preset process parameter reference values.

[0147] Furthermore, the logical instructions in the aforementioned memory 1230 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0148] On the other hand, this application discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the computer, the computer can execute the methods provided in the above-described method embodiments, such as: obtaining the actual values ​​of process parameters during laser solder paste soldering; the process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt state coupling coefficient refers to the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad; and compensating for and controlling the laser output power and soldering time based on the deviation between the actual values ​​of the process parameters and the preset process parameter reference values.

[0149] In another aspect, embodiments of this application also provide a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program performs the methods provided in the above embodiments, including, for example,: acquiring actual values ​​of process parameters during laser solder paste soldering; the process parameters include soldering temperature, solder melt state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt state coupling coefficient refers to the ratio of the mass of molten solder to the total mass of solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​molten solder spread on the pad surface to the total area of ​​the solderable area of ​​the pad; and compensating for and controlling the laser output power and soldering time based on the deviation between the actual values ​​of the process parameters and preset process parameter reference values.

[0150] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0151] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of software products. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should all be covered within the scope of this application.

Claims

1. A method for controlling laser soldering process, characterized in that, include: Obtain the actual values ​​of process parameters during laser solder paste welding; The process parameters include soldering temperature, solder melt molten state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt molten state coupling coefficient refers to the ratio of the mass of the molten solder in the molten state to the total mass of the solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​the molten solder in the molten state spreading on the pad surface to the total area of ​​the solderable area of ​​the pad. Based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters, the laser output power and welding time are compensated and controlled.

2. The laser soldering process control method according to claim 1, characterized in that, The method of compensating for and controlling the laser output power and welding time based on the deviation between the actual value of the process parameters and the preset reference value of the process parameters includes: Based on the deviation between the actual welding temperature and the reference welding temperature, a power correction factor is determined, and the laser output power is compensated and controlled based on the power correction factor. Based on the deviation between the actual value of the coupling coefficient of the molten tin state and the reference value of the coupling coefficient of the molten tin state, and / or the deviation between the actual value of the coupling coefficient of the molten tin spreading pad area and the reference value of the coupling coefficient of the molten tin spreading pad area, a time correction factor is determined, and the soldering time is compensated and controlled based on the time correction factor.

3. The laser soldering process control method according to claim 2, characterized in that, The determination of the power correction factor based on the deviation between the actual welding temperature and the welding temperature reference value includes: Based on the deviation between the actual welding temperature and the welding temperature reference value, the corresponding power correction factor is determined according to the preset temperature deviation-power correction factor mapping relationship.

4. The laser soldering process control method according to claim 3, characterized in that, When the actual welding temperature is less than the welding temperature reference value, the power correction factor is greater than 1 and less than or equal to the first preset threshold; when the actual welding temperature is greater than the welding temperature reference value, the power correction factor is greater than or equal to the second preset threshold and less than 1; when the actual welding temperature is equal to the welding temperature reference value, the power correction factor is 1.

5. The laser soldering process control method according to claim 2, characterized in that, The compensation control of laser output power based on the power correction factor includes: The compensated laser output power is obtained by multiplying the initial laser output power by the power correction factor, and the current laser output power is adjusted to the compensated laser output power.

6. The laser soldering process control method according to claim 2, characterized in that, The time correction factor is determined based on the deviation between the actual value of the coupling coefficient of the molten solder state and the reference value of the coupling coefficient of the molten solder state, and / or the deviation between the actual value of the coupling coefficient of the molten solder pad area and the reference value of the coupling coefficient of the molten solder pad area, including: Based on the deviation between the actual value of the coupling coefficient of the molten tin state and the reference value of the coupling coefficient of the molten tin state, the corresponding first time correction factor is determined according to the preset mapping relationship between the melting deviation and the time correction factor. Based on the deviation between the actual value of the solder spreading pad area coupling coefficient and the reference value of the solder spreading pad area coupling coefficient, the corresponding second time correction factor is determined according to the preset spreading deviation-time correction factor mapping relationship. The time correction factor is determined based on the first time correction factor and / or the second time correction factor.

7. The laser soldering process control method according to claim 6, characterized in that, The time correction factor is greater than or equal to 0 and less than or equal to the third preset threshold.

8. The laser soldering process control method according to claim 6, characterized in that, The compensation control of welding time based on the time correction factor includes: When the actual value of the coupling coefficient of the molten solder state is less than or equal to the reference value of the coupling coefficient of the molten solder state, and the actual value of the coupling coefficient of the molten solder pad area is less than or equal to the reference value of the coupling coefficient of the molten solder pad area, the laser output power after the first compensation is obtained based on the sum of the initial soldering time and the time correction factor, and the current laser output power is adjusted to the laser output power after the first compensation; wherein, the time correction factor is determined based on the first time correction factor and the second time correction factor; When the actual value of the coupling coefficient of the molten tin state is greater than the reference value of the coupling coefficient of the molten tin state, the second compensated laser output power is obtained based on the difference between the initial welding time and the time correction factor, and the current laser output power is adjusted to the second compensated laser output power; wherein, the time correction factor is determined based on the first time correction factor; When the actual value of the coupling coefficient of the solder pad area is greater than the reference value of the coupling coefficient of the solder pad area, the laser output power after the third compensation is obtained based on the difference between the initial soldering time and the time correction factor, and the current laser output power is adjusted to the laser output power after the third compensation; wherein, the time correction factor is determined based on the second time correction factor.

9. The laser soldering process control method according to claim 1, characterized in that, The acquisition of actual values ​​of process parameters during laser solder paste welding includes: During the laser soldering process, sampling is performed according to a preset sampling period to obtain the actual values ​​of the process parameters at the current sampling time; Before compensating for the laser output power and welding time based on the deviation between the actual values ​​of the process parameters and the preset reference values ​​of the process parameters, the method further includes: The actual value of the process parameter at the current sampling time is compared with the preset reference value of the process parameter at the corresponding sampling time to determine the deviation between the actual value of the process parameter and the preset reference value of the process parameter.

10. The laser soldering process control method according to claim 1, characterized in that, The welding temperature is obtained by detecting the temperature value of the solder pad surface using a coaxial infrared temperature detection sensor in the laser head.

11. The laser soldering process control method according to claim 1, characterized in that, The baseline value of the coupling coefficient for the molten tin state is pre-calibrated using the following method: Acquire images of the molten tin state at multiple consecutive sampling moments during the calibration experiment; The image of the molten tin in a molten state is input into a pre-trained visual detection model to obtain the baseline value of the coupling coefficient of the molten tin in a ... Based on the molten tin melting state images and the corresponding molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time, an association database of molten tin melting state images and molten tin melting state coupling coefficient benchmark values ​​at each continuous sampling time is established.

12. The laser soldering process control method according to claim 1, characterized in that, The baseline value for the coupling coefficient of the solder melt spreading pad area is pre-calibrated using the following method: Acquire images of the solder pad area at multiple consecutive sampling times during the calibration experiment; The solder molten solder pad area status image is input into a pre-trained visual detection model to obtain the baseline value of the solder molten solder pad area coupling coefficient corresponding to the solder molten solder pad area status image. Based on the solder pad area status images at each continuous sampling time and the corresponding solder pad area coupling coefficient benchmark values, a correlation database is established between the solder pad area status images at each continuous sampling time and the solder pad area coupling coefficient benchmark values.

13. A laser soldering process control device, characterized in that, include: The parameter acquisition module is used to acquire the actual values ​​of process parameters during laser solder paste welding. The process parameters include soldering temperature, solder melt molten state coupling coefficient, and solder melt spreading pad area coupling coefficient; the solder melt molten state coupling coefficient refers to the ratio of the mass of the molten solder in the molten state to the total mass of the solder paste, and the solder melt spreading pad area coupling coefficient refers to the ratio of the area of ​​the molten solder in the molten state spreading on the pad surface to the total area of ​​the solderable area of ​​the pad. The compensation control module is used to compensate and control the laser output power and welding time based on the deviation between the actual value of the process parameters and the preset process parameter reference value.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the laser soldering process control method as described in any one of claims 1 to 12.

15. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the laser soldering process control method as described in any one of claims 1 to 12.

16. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the laser soldering process control method as described in any one of claims 1 to 12.

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