Full-automatic production process of GMOV composite element

Abstract

The invention discloses a full-automatic production process of a GMOV composite element, and belongs to the technical field of automatic manufacturing of electronic elements. According to the method, lead forming and tinning, positioning and leveling, visual guiding element assembling, controllable atmosphere preheating and selective welding, AI intelligent detecting and sorting, cleaning and double-coating coating and full-process data tracing are sequentially carried out. According to the technology, through full-process automatic integration, the defects that in a traditional production mode, procedures are dispersed, manual operation is relied on, the positioning precision is low, and quality fluctuation is large are overcome, and high-precision assembly and high-reliability welding are achieved. And meanwhile, intelligent quality detection and cloud data tracing are combined, so that the production efficiency and the product consistency and reliability are remarkably improved, the full-life-cycle quality management of a single product is realized, and the method is suitable for large-scale and high-quality manufacturing requirements of GMOV elements.

Description

Technical Field

[0001] This invention relates to the field of electronic component manufacturing technology, and in particular to a fully automated production process for GMOV composite components. Background Technology

[0002] GMOV (Gas-Resistor-Gas-Discharge Tube Composite Component) is a composite electronic component that integrates the surge suppression characteristics of MOV and the isolation characteristics of GDT. It is widely used in overvoltage protection scenarios in power supply, communication, security and other fields. At present, the production of GMOV still mainly relies on traditional manual or semi-automatic methods, which has the following significant technical pain points: (1) Dispersed processes and serious reliance on manual labor. In traditional processes, core steps such as lead forming, component insertion, solder paste application and welding are mostly manual operations. Manual transfer is required between processes, resulting in poor production continuity and low efficiency. (2) Insufficient positioning accuracy. There is a lack of dedicated positioning tools for the assembly of MOV and GDT on the lead. Manual insertion is prone to component position deviation, which directly affects the consistency of product electrical performance. (3) Unstable welding quality. In manual or semi-automatic welding, insufficient preheating and uncontrollable welding temperature and time can easily lead to defects such as cold solder joints, bubbles and solder overflow, resulting in large fluctuations in product yield. (4) Low production efficiency and consistency. Manual operation results in limited single-shift capacity (typically ≤5000 units / shift), and the differences in operation among different operators make it difficult to maintain a product yield rate above 95%. In addition, the existing production model lacks the ability to record and trace data throughout the entire process, making it difficult to quickly locate the cause in the event of batch problems.

[0003] To address the aforementioned issues, there is an urgent need for an integrated, highly automated, process-controllable, and traceable GMOV production solution to meet the demands of large-scale mass production for efficiency, quality, and reliability. Summary of the Invention

[0004] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide a fully automated production process for GMOV composite components. This process provides a fully automated, precise, stable welding, batch-reproducible, and single-piece lifecycle traceability GMOV composite component production process, overcoming the shortcomings of existing GMOV production, such as "manual dependence, low positioning accuracy, unstable welding quality, low efficiency, and lack of traceability".

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A fully automated production process for GMOV composite components includes the following steps: S1. Lead forming and tinning: The copper alloy lead wire is drawn and straightened in the line, and then the end of the lead wire is continuously stamped into a predetermined shape under the protective atmosphere formed by inert gas, and the formed part is tinned at the same time. S2. Positioning and Leveling: The pre-treated lead wire is loaded into the positioning fixture, and the fixture is locked on the transmission path by magnetic attraction. Then, a controllable elastic pressing action is used to apply uniform downward pressure to each pin of the lead wire and then release it to eliminate its rebound stress and ensure that each pin is coplanar. S3. Visual Assembly: Based on the machine vision system, the position recognition and coordinate compensation of the stress-released lead pins are performed. The multi-axis robotic arm performs the following sub-steps: First, it picks up the varistor and accurately places it in the first target position of the lead; then, it applies a certain amount of solder paste to the center of the top surface of the varistor; finally, it picks up the gas discharge tube and accurately places it in the second target position of the lead, thereby completing the spatial layout of the varistor and the gas discharge tube on the lead. S4. Preheating and Welding: The completed components are sent to a preheating device with oxygen content control capability for uniform preheating; after preheating, the reflow soldering, flame soldering or dip soldering mode is automatically selected and executed according to the physical and chemical properties of the lead substrate for welding connection. S5, AI Detection and Sorting: A combination of bright and dark field lighting system is used to image the weld points, obtain their appearance and internal quality information, and use artificial intelligence algorithms to analyze the images to automatically identify welding defects and sort out unqualified products accordingly. S6. Cleaning and Coating: For qualified products, perform frequency sweep ultrasonic cleaning to remove process residues; after cleaning and drying, apply epoxy resin insulating coating and silicone resin protective coating in sequence by electrostatic spraying, and perform independent leveling and curing treatment on each coating. S7. Data Traceability: At key process nodes from upstream to downstream of the production line, collect and associate equipment status, process parameters and quality data in real time, write them into the identification carrier of the accompanying vehicle and upload them to the remote server simultaneously to build a digital production history for a single product.

[0006] As a preferred embodiment: in step S2, the magnetic attraction force is achieved by causing the magnetic unit inside the fixture body to generate an attraction force with the corresponding magnetic unit on the transmission path; the controllable elastic pressing action is accomplished by a reciprocating elastic pressing head assembly.

[0007] As a preferred embodiment: in step S4, the preheating device with oxygen content control capability achieves a low-oxygen atmosphere by introducing inert gas into the preheating chamber and monitoring the oxygen concentration in the chamber in real time; the automatic selection of welding energy mode according to the lead substrate includes at least a hot air reflow soldering mode for conventional copper-based leads and a spectral closed-loop controlled flame soldering mode for special coated leads.

[0008] As a preferred embodiment: In step S5, the artificial intelligence algorithm is a convolutional neural network model, which is trained to simultaneously receive bright field images and dark field images, and output the classification and confidence level of solder joint defects.

[0009] As a preferred embodiment: the diameter of the copper alloy lead wire is 0.5-1.0 mm; the size of the varistor is 5-20 mm; and the size of the gas discharge tube is 4-15 mm.

[0010] As a preferred embodiment: in step S1, the continuous stamping of the lead end into a predetermined shape means processing the lead into an L-shape or a U-shape, and controlling the forming accuracy within ±0.1mm.

[0011] As a preferred embodiment: in step S3, the amount of solder paste applied is 0.04-0.06 g / dot, and the dotting position deviation is no greater than 0.05 mm; the repeatability of the multi-axis robotic arm in performing the grasping and placing actions is ±0.03 mm.

[0012] As a preferred embodiment: in step S3, the varistor and the gas discharge tube are assembled in the same positioning fixture, and the center distance deviation between the two is controlled to not exceed 0.1 mm; in step S4, the temperature of the uniform preheating is 110-180℃ and the time is 50-70s.

[0013] As a preferred embodiment: In step S4, when the hot air reflow soldering mode is selected, the process curve is as follows: the temperature is increased at a rate of 5℃ / s, held at 150℃ for 40s, and maintained in the peak temperature range of 225-275℃ for 8-12s; when the spectral closed-loop control flame soldering mode is selected, the flame temperature is controlled at 500-1000℃, and the soldering time is 2-4s; when the dip soldering mode is selected, the component is immersed in the molten solder for soldering, and the solder joint morphology is controlled by controlling the immersion depth and time.

[0014] As a preferred embodiment: in step S5, the overall pass rate of the weld joint quality assessment is not less than 99.5%; in step S6, the frequency variation range of the sweep ultrasonic cleaning is 35-45kHz, and the cleaning time is 1-4min; the thickness of the epoxy resin coating and the silicone resin coating is 0.3-0.8mm respectively.

[0015] Compared with the prior art, the present invention has significant advantages and beneficial effects. Specifically, as can be seen from the above technical solution, the beneficial effects of the present invention are as follows: 1. High degree of automation and production efficiency: The entire process requires no manual intervention, integrating traditional scattered processes into continuous automated production. The single-shift capacity can be increased to 15,000-40,000 pieces, which is 3-8 times higher than the traditional process.

[0016] 2. Superior positioning and welding accuracy, resulting in strong product consistency: By combining magnetic fixation, elastic leveling, and visual compensation, component placement accuracy is achieved at the ±0.03mm level, with MOV and GDT center distance deviation ≤0.1mm. Combined with low-oxygen preheating and closed-loop controlled welding processes, the rate of incomplete solder joints is reduced to ≤0.5% (compared to ≥3% in traditional processes), and the fluctuation range of key electrical parameters (such as clamping voltage) is compressed to ≤±2%.

[0017] 3. Quality Control and Reliability Enhancement: 100% online full inspection is performed using dual-light source AI vision, achieving a pass rate of ≥99.5%, effectively preventing defective products from leaving the product. Frequency-sweeping ultrasonic cleaning and an epoxy-silicone resin dual-coating process significantly improve product cleanliness and long-term environmental reliability.

[0018] 4. Complete traceability: Through RFID and cloud technology, data binding and traceability of a single product throughout its entire lifecycle, from raw materials to finished products, are realized, greatly shortening the time for quality traceability and batch recall.

[0019] 5. Reduced overall costs: Automated production reduces the need for direct labor, increases output per capita, and reduces material waste due to high yield, resulting in a 20-30% reduction in overall production costs.

[0020] To more clearly illustrate the structural features and effects of the present invention, a detailed description is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the fully automated production process of the GMOV composite element described in this invention. Figure 2 This is a schematic diagram of the fully automated production process of GMOV composite components according to the present invention. Detailed Implementation

[0022] The present invention is as follows Figure 1-2 As shown, a fully automated production process for GMOV composite components is provided, which reconstructs traditional discrete, manual-dependent processes into a continuous, parameter-controllable automated process chain. The following is combined with... Figure 1 Each step is explained in detail according to the process sequence.

[0023] S1. Lead Forming and Tinning: This step aims to provide high-quality lead substrate for subsequent assembly. First, the coiled copper alloy leads (with diameters typically ranging from 0.5-1.0 mm depending on product specifications) are uncoiled and enter an online drawing and straightening system. This system effectively eliminates initial bending and internal residual stress in the leads through micro-plastic bending and high-frequency straightening using multi-stage rollers, outputting a straight strip with excellent straightness. Subsequently, the strip is precisely fed into the tinning station. This station is in a localized protective atmosphere formed by an inert gas (such as nitrogen), with the oxygen content controlled at a low level (e.g., below 500 ppm) to prevent oxidation during subsequent high-temperature processes. Under this protection, the lead ends are continuously stamped into preset geometric shapes, such as L-shapes or U-shapes, to meet the structural requirements of different products, with forming accuracy controlled within ±0.1 mm. After forming, the lead ends are immediately coated with a uniform, bright tin layer by immersion or spraying. The entire process is carried out continuously, ensuring the consistency of lead dimensions, the accuracy of shape, and the uniformity and oxidation resistance of solder coating.

[0024] S2. Positioning and Leveling: This step ensures the positional stability and coplanarity of the leads during subsequent precision assembly. The leads, processed in S1, are cut into individual pieces and placed in a dedicated positioning fixture. To achieve zero micro-motion during high-speed transmission, a magnetic fixing process is employed: by interacting with the controllable magnetic unit inside the fixture and the fixed magnetic unit on the transmission path, a stable attraction force is generated, firmly locking the fixture in place at the processing station, ensuring stable and reliable positioning. Next, elastic leveling is performed: a pressure head assembly driven by an elastic element applies a brief, controllable, and uniform vertical downward pressure to each pin of the leads in the fixture, followed by immediate release. This "press-release" action effectively eliminates the internal springback stress generated by the stamping process, ensuring all pins achieve a highly consistent coplanar state within the same plane (coplanarity is typically better than 0.05mm), laying the foundation for uniform and reliable solder joints during subsequent welding.

[0025] S3. Vision Assembly: This step is crucial for ensuring the relative positional accuracy of the two core components, MOV and GDT. First, a high-resolution machine vision system rapidly captures images of the leveled lead pins. Image processing algorithms identify the actual position of the pin edges at the sub-pixel level and compare it with theoretical coordinates, calculating the deviations in the X and Y directions and the rotation angle. These deviation data are sent to the motion control system as real-time compensation values. Subsequently, a series of ordered assembly sub-steps are executed by a multi-axis robotic arm with a repeatability accuracy of ±0.03mm: The first step involves the robotic arm picking up a varistor (MOV, typically 5-20mm in size) from the feed tray based on the coordinates compensated by the vision system, and precisely placing it on the first preset station on the lead frame.

[0026] The second step involves applying solder paste to the center of the positioned MOV top surface using a high-precision metering dispensing device. The dispensing amount is strictly controlled within a minute range of 0.04-0.06g / dot, and the center deviation of the dispensing position is no more than 0.05mm to ensure sufficient solder and prevent overflow during subsequent soldering.

[0027] The third step involves the robotic arm, guided by vision, grasping a gas discharge tube (GDT, typically 4-15mm in size) and precisely placing it on the lead wire at the second preset station adjacent to the MOV.

[0028] By sequentially assembling the MOV and GDT within the same high-precision positioning fixture, and relying on the geometric constraints formed by the precision-machined contour grooves or flanges of the fixture itself, the spacing deviation between the central axes of the two components can be strictly controlled within a range of no more than 0.1mm, thereby ensuring the consistency of the electrical performance of the final product.

[0029] S4. Preheating and Soldering: This step aims to create a strong and reliable electrical connection. The assembled semi-finished product is placed in a tunnel-type preheating zone. This zone maintains a low oxygen level (low-oxygen atmosphere) by continuously introducing inert gas and using oxygen sensors for real-time monitoring and feedback control, effectively inhibiting oxidation of the solder paste surface. The product is uniformly heated to 110-180°C in this low-oxygen environment and held for 50-70 seconds. This preheating process allows volatile components such as solvents and activators in the solder paste to fully escape, preventing bubbles or spatter during subsequent high-temperature soldering.

[0030] After preheating, the system automatically selects the optimal welding energy mode based on the material characteristics of the lead substrate (such as ordinary copper alloy or nickel-plated steel).

[0031] For conventional copper-based leads, the hot air reflow soldering mode is automatically selected. The product enters the reflow oven and is soldered according to a preset precision temperature profile: first, the temperature is raised to about 150°C at a rate of about 5°C / s and held at this temperature for about 40 seconds to ensure uniform component temperature; then, the temperature is rapidly raised to the peak temperature range above the liquidus line of 225-275°C and held for 8-12 seconds to completely melt and wet the solder paste, forming a good intermetallic compound (IMC) bond; finally, it is cooled and solidified.

[0032] For lead wires made of special materials (such as nickel-plated steel), the system automatically switches to a closed-loop spectral control flame welding mode. A multi-axis automatic flame torch is used to locally heat the weld joint. The flame temperature is precisely controlled within the range of 500-1000℃, and the welding time is controlled within 2-4 seconds. During this process, a spectral sensor collects the intensity of the characteristic spectral lines of the flame in real time. The control system dynamically adjusts the mixing ratio of fuel gas and oxygen accordingly, achieving closed-loop stable control of the flame's thermal energy output. This ensures the accuracy and consistency of the welding heat input, adapting to the welding requirements of special materials.

[0033] For processes requiring thick solder joints or specific termination configurations, a third dip soldering mode can be used: A servo mechanism vertically and smoothly immerses the assembly into a temperature-controlled molten solder bath. By precisely controlling the immersion depth and duration, the assembly is immersed in molten solder at 250-300°C for 3-10 seconds, ensuring the solder fully wets the leads and forms full, consistent solder joints. The dip soldering process can also be performed under inert gas protection to prevent oxidation. The three soldering modes (reflow soldering, flame soldering, and dip soldering) are automatically selected by the system based on preset product recipes, requiring no manual intervention.

[0034] S5. AI Inspection and Sorting: This step involves 100% automated online inspection of welding quality. Welded products enter a vision inspection station equipped with a combined bright-field ring light source and dark-field oblique light source lighting system. Bright-field lighting clearly acquires the shape, contour, and wetting angle of the weld joint to obtain surface morphology information; dark-field lighting illuminates at a low angle, highlighting potential defects such as porosity and cracks within the weld joint due to light scattering. Images under both lighting conditions are acquired simultaneously. The images are then input into a pre-trained convolutional neural network (CNN) model with a large number of samples. This model can comprehensively analyze the features of both images, automatically identifying various defect types such as cold welds, bridging, solder balls, porosity, and incomplete welds, and outputting the confidence level for each judgment. The system compares the confidence level with a preset judgment threshold and drives the sorting mechanism (such as an air nozzle) in real time, automatically rejecting products judged as unqualified to the defective product channel, ensuring that the overall pass rate of qualified products leaving this process is not less than 99.5%.

[0035] S6. Cleaning and Coating: This step provides reliable protection for the product. First, qualified products enter the cleaning stage and are placed in an ultrasonic cleaning tank. The cleaning machine uses frequency sweeping technology, causing the ultrasonic emission frequency to continuously and periodically change within the range of 35-45kHz. This frequency sweeping mode can excite cavitation bubbles of different sizes, producing a more uniform and penetrating cavitation effect. Combined with a neutral and environmentally friendly water-based cleaning agent, it can effectively remove residual flux and oxide particle contaminants around solder joints and in component gaps within a cleaning time of 1-4 minutes.

[0036] After cleaning and hot air drying, the product enters the coating line. The first coating layer is applied: using electrostatic spraying, epoxy resin powder is evenly adhered to the product surface, forming an insulating and mechanically reinforcing coating with a thickness controlled between 0.3-0.8 mm. After spraying, the product enters the leveling and curing zone, where leveling and pre-curing are performed at 110-160℃ to allow the coating to initially set. The second coating layer is then applied: again using electrostatic spraying, a silicone resin coating is applied on top of the epoxy coating, also with a thickness of 0.3-0.8 mm. The silicone resin coating primarily provides excellent moisture resistance, salt spray resistance, weather resistance, and electrical insulation stability. Independent leveling and pre-curing processes between the two coatings effectively prevent the miscibility of different coating materials. Finally, the product completes final curing at the set temperature, forming a dense, robust, and fully functional double-layer composite protective structure.

[0037] S7. Data Traceability: To achieve quality control and information traceability throughout the product lifecycle, a data acquisition and binding system is embedded in the entire production process. Each carrier (or pallet) carrying the product is equipped with a unique readable and writable RFID (Radio Frequency Identification) tag. As the carrier carries the product through key process nodes such as S1 (loading), S3 (assembly), S4 (welding), S5 (inspection), and S6 (painting), the reader at that station automatically writes relevant information (such as equipment number, actual process parameter values, visual inspection results, and timestamps) into the carrier's RFID tag. Simultaneously, this data is uploaded in real-time and stored in a cloud database via the workshop's IoT network using lightweight communication protocols such as MQTT. Thus, each GMOV finished component is associated with a complete digital production history. By scanning the QR code on the product packaging or querying the serial number, the manufacturing data of that single product in all key processes can be traced back in the cloud, achieving forward traceability from raw materials to finished products and reverse traceability from the market to the production end, providing a solid data foundation for quality analysis, rapid recall, and process optimization.

[0038] The key design focus of this invention is to address the long-standing technical bottlenecks in the production of traditional GMOV (Gas-Modulator-Gas Discharge Tube) components, such as discrete processes, heavy reliance on manual labor, low positioning accuracy, large fluctuations in welding quality, and a lack of effective traceability systems. It constructs a fully automated, high-precision, parameterized, and traceable integrated production process. Its core is not to provide isolated equipment improvements, but rather to achieve closed-loop management of "process-quality-data" through the systematic restructuring of the entire manufacturing chain and precise control of key processes.

[0039] First, this invention creatively integrates multiple traditionally dispersed independent workstations (such as lead forming, component insertion, soldering, testing, coating, etc.) into a seamless automated process sequence (S1 to S7). This reconstruction breaks through the efficiency and consistency barriers of manual transfer between processes, laying the foundation for efficient mass production. Crucially, in the component precision assembly stage (S3), a collaborative sub-step process is designed, involving "visual positioning compensation," "robotic arm gripping and placement," and "quantitative solder paste application." Furthermore, "magnetic fixation" (S2) and "elastic pre-pressure leveling" (S2) provide an ultra-stable positioning reference and coplanar guarantee for assembly, thereby controlling key dimensional accuracy such as the center distance deviation between MOV and GDT, and the dispensing position error, to the micrometer level (e.g., ≤0.1mm, ±0.05mm), ensuring the consistency of product electrical performance from the source.

[0040] Secondly, in the soldering stage (S4), which determines connection reliability, this invention proposes a composite solution of "low-oxygen preheating" and "mode selection." Preheating under inert gas protection effectively suppresses solder paste oxidation and reduces soldering defects. Furthermore, it innovatively integrates three soldering modes: "reflow soldering," "flame soldering," and "dip soldering," which can be automatically selected according to lead material and product specifications. This selective design gives the process strong adaptability, meeting the needs of efficient batch reflow soldering of conventional copper-based leads, addressing the requirements of flame soldering for special materials (such as nickel-plated steel), and achieving thick solder joints of specific shapes through dip soldering, thus realizing flexible manufacturing.

[0041] Furthermore, this invention deeply integrates intelligent quality control and end-to-end data traceability into the production process. In the post-weld inspection stage (S5), an AI inspection scheme combining "bright-field and dark-field dual-light source imaging" with a "convolutional neural network (CNN) artificial intelligence model" is employed, achieving high-precision, high-speed full inspection and automatic sorting of defects such as cold welds and porosity. In the post-processing stage (S6), the "frequency-sweeping ultrasonic cleaning" and "epoxy-silicone resin dual-coating electrostatic spraying curing" processes significantly improve the cleanliness and long-term environmental reliability of the products. More importantly, through RFID-based identification carriers and a cloud database (S7), the process parameters, equipment status, and quality data of each product at each key workstation are bound and uploaded in real time, achieving precise traceability of the entire lifecycle from raw materials to finished products at the single-piece level, providing a data foundation for quality analysis, process optimization, and rapid recall.

[0042] In summary, the design focus of this invention is a systematic process innovation: it uses full-process automation integration as its framework, high-precision assembly and controllable welding as its core process control points, and AI intelligent detection and data traceability as its quality assurance and information technology support. Through precise coordination of parameters between each step (such as matching preheating temperature with welding curves, and controlling dispensing amount and coating thickness), this solution not only increases single-shift production capacity several times and reduces the rate of false soldering to an extremely low level, but also improves consistency and reliability while constructing a digital twin of product manufacturing. This achieves a paradigm shift in quality control from "post-inspection" to "prevention and full-process controllability," thus providing a complete solution for the large-scale manufacturing of high-reliability electronic components.

[0043] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A fully automated production process for GMOV composite components, characterized in that, Includes the following steps: S1. Lead forming and tinning: The copper alloy lead wire is drawn and straightened in the line, and then the end of the lead wire is continuously stamped into a predetermined shape under the protective atmosphere formed by inert gas, and the formed part is tinned at the same time. S2. Positioning and Leveling: The pre-treated lead wire is loaded into the positioning fixture, and the fixture is locked on the transmission path by magnetic attraction. Then, a controllable elastic pressing action is used to apply uniform downward pressure to each pin of the lead wire and then release it to eliminate its rebound stress and ensure that each pin is coplanar. S3. Visual Assembly: Based on the machine vision system, the position recognition and coordinate compensation of the stress-released lead pins are performed. The multi-axis robotic arm performs the following sub-steps: First, it picks up the varistor and accurately places it in the first target position of the lead; then, it applies a certain amount of solder paste to the center of the top surface of the varistor; finally, it picks up the gas discharge tube and accurately places it in the second target position of the lead, thereby completing the spatial layout of the varistor and the gas discharge tube on the lead. S4. Preheating and Welding: The completed components are sent to a preheating device with oxygen content control capability for uniform preheating; after preheating, the reflow soldering, flame soldering or dip soldering mode is automatically selected and executed according to the physical and chemical properties of the lead substrate for welding connection. S5, AI Detection and Sorting: A combination of bright and dark field lighting system is used to image the weld points, obtain their appearance and internal quality information, and use artificial intelligence algorithms to analyze the images to automatically identify welding defects and sort out unqualified products accordingly. S6. Cleaning and Coating: For qualified products, perform frequency sweep ultrasonic cleaning to remove process residues; after cleaning and drying, apply epoxy resin insulating coating and silicone resin protective coating in sequence by electrostatic spraying, and perform independent leveling and curing treatment on each coating. S7. Data Traceability: At key process nodes from upstream to downstream of the production line, collect and associate equipment status, process parameters and quality data in real time, write them into the identification carrier of the accompanying vehicle, and upload them to the remote server simultaneously to build a digital production history for a single product.

2. The process according to claim 1, characterized in that, In step S2, the magnetic attraction force is achieved by causing the magnetic unit inside the fixture body to attract the corresponding magnetic unit on the transmission path; the controllable elastic pressing action is accomplished by a reciprocating elastic pressing head assembly.

3. The process according to claim 1, characterized in that, In step S4, the preheating device with oxygen content control capability achieves a low-oxygen atmosphere by introducing inert gas into the preheating chamber and monitoring the oxygen concentration in the chamber in real time; the automatic selection of welding energy mode according to the lead substrate includes at least a hot air reflow soldering mode for conventional copper-based leads and a spectral closed-loop control flame soldering mode for special coated leads.

4. The process according to claim 1, characterized in that, In step S5, the artificial intelligence algorithm is a convolutional neural network model, which is trained to simultaneously receive bright field images and dark field images, and output the classification and confidence level of solder joint defects.

5. The process according to claim 1, characterized in that, The diameter of the copper alloy lead wire is 0.5-1.0 mm; the size of the varistor is 5-20 mm; and the size of the gas discharge tube is 4-15 mm.

6. The process according to claim 1, characterized in that, In step S1, the continuous stamping of the lead end into a predetermined shape means processing the lead into an L-shape or a U-shape, and controlling the forming accuracy within ±0.1mm.

7. The process according to claim 1, characterized in that, In step S3, the amount of solder paste applied is 0.04-0.06 g / dot, and the dotting position deviation is no greater than 0.05 mm; the repeatability of the multi-axis robotic arm in performing the grasping and placing actions is ±0.03 mm.

8. The process according to claim 1, characterized in that, In step S3, the varistor and the gas discharge tube are assembled in the same positioning fixture, and the center distance deviation between them is controlled to not exceed 0.1 mm; in step S4, the temperature of the uniform preheating is 110-180℃ and the time is 50-70s.

9. The process according to claim 1, characterized in that, In step S4, when the hot air reflow soldering mode is selected, the process curve is as follows: the temperature is increased at a rate of 5℃ / s, held at 150℃ for 40s, and maintained in the peak temperature range of 225-275℃ for 8-12s. When the closed-loop spectral control flame soldering mode is selected, the flame temperature is controlled at 500-1000℃ and the soldering time is 2-4s; when the dip soldering mode is selected, the components are immersed in molten solder for soldering, and the solder joint shape is controlled by controlling the immersion depth and time.

10. The process according to claim 1, characterized in that, In step S5, the overall pass rate of the weld quality judgment is not less than 99.5%; in step S6, the frequency variation range of the sweep ultrasonic cleaning is 35-45kHz, and the cleaning time is 1-4min; the thickness of the epoxy resin coating and the silicone resin coating is 0.3-0.8mm respectively.

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