A photovoltaic module string welding process and a string welding processing device thereof

Abstract

The present application relates to a kind of photovoltaic module string welding processing technology in photovoltaic module string welding processing technical field, steps include: glass plate bottom heating makes upper surface adhesive film melt adhesion;Finished cell piece is scribed and dried to obtain initial temperature;Visual positioning manipulator grabs multiple cell pieces, blows hot and maintains temperature and accurately places to melt adhesive film, utilizes heat to realize fast bonding fixation;Laser welding is formed after laying out welding wire;It also relates to welding processing equipment: glass bearing plate feeding mechanism, scribing and feeding mechanism, piece placing table and manipulator, adhesive bonding mechanism, welding station and unloading module of configuration wire drawing module group.The present application reduces the equipment floor space by integrating piece placing and welding link;Avoid secondary handling after welding, reduce damage risk;Using manipulator multiple grabbing, hot air temperature maintenance and laser welding technology, improve production efficiency.

Description

Technical Field

[0001] This invention relates to the field of solar cell stringing technology, and more specifically, to a photovoltaic module stringing process. Background Technology

[0002] In the production of photovoltaic modules, the efficiency and reliability of the cell string welding process are crucial. Traditional processing requires staged welding and arrangement of cell strings. Specifically, after placing the same string of cells, it is transported by conveyor belt to the first welding station for welding. Then, a robotic arm picks up the welded cell string and arranges it on a glass plate. After all cell strings are arranged, they are transported to the second welding station for overall plate welding. This process requires two placement areas and corresponding welding stations, forming a "placement table-welding station-placement table-welding station" layout along the conveyor belt direction, resulting in a large equipment footprint and low space utilization. Furthermore, when the robotic arm picks up the welded cell strings for secondary handling, care must be taken to avoid damaging the welding positions, increasing operational risks and product defect rates. In addition, the traditional process of placing, welding, and waiting for arrangement of cells string by string is cumbersome, with long placement times for individual cell strings. Combined with the slow speed of secondary handling and traditional welding technologies (such as infrared heating), overall production efficiency is low.

[0003] Therefore, how to solve the shortcomings of traditional processes, such as large equipment footprint, high operational risks, and low production efficiency, has become an urgent problem to be solved in the industry. Summary of the Invention

[0004] To overcome the problems of existing photovoltaic module string welding processing equipment having a large footprint, easy damage to the welding position during secondary handling of battery strings, cumbersome and inefficient production process, and slow speed of traditional welding technology, this invention provides a photovoltaic module string welding processing technology and string welding processing equipment.

[0005] The technical solution of this invention is as follows:

[0006] A photovoltaic module string bonding process includes the following steps:

[0007] S1. Glass plate preparation and adhesive film treatment: Provide a glass plate, cover the upper surface of the glass plate with an adhesive film, and heat the bottom of the glass plate to make the adhesive film melt and adhere.

[0008] S2. Battery cell preparation: Provide finished battery cells coated with insulating adhesive. The finished battery cells are diced into several smaller battery cells. The dicing process is dried to bring the battery cells to an initial temperature.

[0009] S3, Disposable Array Placement: Using a robotic arm equipped with a vision positioning system, multiple battery cells from step S2, which have reached an initial temperature, are simultaneously grasped. During the grasping process, the robotic arm continuously blows hot air onto the grasped battery cells through its heating nozzles to maintain or increase the battery cell temperature. Guided by the vision positioning system, the grasped battery cells are precisely placed onto the adhesive film in the molten adhesive film from step S1 according to a preset array position. The heat of the battery cells promotes their rapid and firm adhesion to the molten adhesive film, thereby fixing the position of the battery cells.

[0010] S4. Welding: Welding wires are laid on the glass plate after the array is completed to connect the cells in the array in series and then laser weld them to form the cell string of the photovoltaic module.

[0011] As a preferred embodiment of the present invention, the glass plate preparation process in step S1 specifically includes:

[0012] S101, Receive glass plates via horizontal glass plate transmission lines;

[0013] S102. Transfer the glass plate to the vertical glass plate transmission line that is perpendicular to the horizontal transmission line;

[0014] S103. At the front end of the vertical transmission line, cover the upper surface of the glass plate with the adhesive film and simultaneously heat the bottom of the glass plate to 70-90℃ to melt the adhesive film.

[0015] S104. Use a scraper to smooth the molten adhesive film to form a uniform adhesion layer.

[0016] As a preferred embodiment of the present invention, the cell preparation process in step S2 includes:

[0017] The finished solar cells are divided into several smaller solar cells using laser scribing.

[0018] Dry at 80-100℃ for 3 to 10 seconds to give the cells an initial temperature of 40℃ to 60℃.

[0019] As a preferred embodiment of the present invention, in step S3:

[0020] The robotic arm can simultaneously grasp 4 or 6 battery cells;

[0021] The temperature of the hot air outlet is set to 80℃, and the air velocity is 0.5 to 2m / s;

[0022] During the placement of the battery cells, their surface temperature is maintained at 70°C to 80°C, and the bonding and curing time after contact with the adhesive film is ≤1.0 second.

[0023] As a preferred embodiment of the present invention, the visual positioning system in step S3 performs the following operations:

[0024] Establish a coordinate system by identifying the positioning marks at the four corners of the glass plate;

[0025] Real-time correction of battery cell grasping posture deviation;

[0026] The accuracy error of the placement position is controlled to be ≤ ±0.2mm.

[0027] As a preferred embodiment of the present invention, the welding process in step S4 includes:

[0028] Simultaneous operation via a dual-station welding system;

[0029] Multiple parallel welding wires are laid on the battery cell array using a wire drawing module;

[0030] The laser welding spot length is 10 to 40 mm and the width is 2 to 8 mm.

[0031] As a preferred embodiment of the present invention, the specific steps of the laser welding are as follows:

[0032] A pressing mechanism is covered on the surface of the battery cell array with welding wires already laid, so that the parallel heat-conducting medium body accurately presses the weld seam corresponding to multiple parallel welding wires.

[0033] The elongated light spot shines on the heat-conducting medium, and the heat is conducted through the medium to the welding wire to achieve fusion bonding.

[0034] The present invention also provides a photovoltaic module stringing processing equipment, comprising:

[0035] A glass support plate feeding mechanism is used to transport glass plates with molten adhesive film to the inlet of the string welding line;

[0036] A dicing and feeding mechanism is used to provide solar cells with initial temperature.

[0037] A cell placement table and a cell placement robot are located at the front end of the stringing process line to receive battery cells from the dicing and feeding mechanism. The cell placement robot is equipped with a vision positioning system, and its end effector is equipped with a suction cup for gripping battery cells and a hot air nozzle located relatively in the middle of the suction cup. The cell placement robot is configured to grip multiple battery cells simultaneously. During the gripping process, hot air is continuously blown onto the battery cells through the hot air nozzle to maintain or increase their temperature. Guided by the vision positioning system, the gripped multiple battery cells are precisely placed on a glass plate with a molten adhesive film located at the cell placement table according to a preset array position.

[0038] An adhesive applicator is used to provide adhesive strips to the glass plate on which the solar cells have been placed and to adhere them to the solar cells.

[0039] The welding station is located after the adhesive application mechanism, and its front and rear ends are equipped with wire drawing modules for laying welding wire to connect the battery cells in the array and performing laser welding.

[0040] The unloading module and the output conveyor belt are used to unload and output the welded photovoltaic modules.

[0041] As a preferred embodiment of the present invention, the glass support plate feeding mechanism includes a horizontal glass plate conveying line and a vertical glass plate conveying line; the horizontal glass plate conveying line is arranged parallel to the string welding processing line and is used to convey the glass plate to the vertical glass plate conveying line, and the vertical glass plate conveying line is arranged perpendicular to the horizontal glass plate conveying line and is used to convey the glass plate with molten adhesive film to the inlet of the string welding processing line.

[0042] Furthermore, the front end of the vertical glass plate transmission line is provided with an adhesive film attaching device, which is used to cover the glass plate with an adhesive film and heat the bottom of the glass plate to melt and adhere the adhesive film. The adhesive film attaching device is also provided with a scraper for smoothing the adhesive film.

[0043] According to the above-described solution, the beneficial effects of this invention are as follows:

[0044] This invention integrates multiple operation steps by using a one-time array arrangement and direct welding on a glass plate. The battery cell placement and welding process can be completed in only one main operation area, which significantly reduces the equipment footprint and improves space utilization.

[0045] This invention allows for the direct placement of solar cells onto a molten adhesive film by a robotic arm before they are welded, avoiding secondary handling of the welding area and effectively reducing the risk of damage. In the one-time array placement step, the robotic arm simultaneously grasps multiple solar cells and places them quickly and accurately, reducing the time spent placing individual cells. Furthermore, it eliminates the time spent on secondary handling of battery strings and waiting for layout in traditional processes, making the production process more compact and efficient. Simultaneously, the application of laser welding technology further accelerates the welding speed, significantly improving the overall production efficiency of photovoltaic modules.

[0046] Furthermore, by dicing and drying the solar cells to bring them to an initial temperature, and by continuously blowing hot air through hot air vents during the grasping process to maintain or increase the temperature, the solar cells at high temperature can quickly promote molecular diffusion and cross-linking reactions when they come into contact with the molten adhesive film, thereby achieving rapid and firm bonding and improving the structural stability and reliability of the photovoltaic module. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the present invention;

[0048] Figure 2 This is a flowchart of the process method of the present invention;

[0049] Figure 3 A flowchart of the steps for preparing the glass plate;

[0050] Figure 4 A flowchart of the steps for preparing solar cells;

[0051] Figure 5 This is a flowchart of the solar cell placement process.

[0052] In the diagram,

[0053] 1. Glass support plate feeding mechanism; 11. Horizontal glass plate conveyor line; 12. Vertical glass plate conveyor line; 13. Glass picking robot;

[0054] 2. Slicing and feeding mechanism;

[0055] 3. Slide loading table; 31. Slide loading robot;

[0056] 4. Adhesive application mechanism;

[0057] 5. Welding station; 51. Wire drawing module;

[0058] 6. Material feeding module; 61. Material discharge conveyor belt. Detailed Implementation

[0059] To better understand the purpose, technical solution, and technical effects of this invention, the invention will be further explained and described below in conjunction with the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also stated that the embodiments described below are only for explaining this invention and are not intended to limit this invention.

[0060] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there may be an intermediate component.

[0061] The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, and is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The term "a plurality of" means two or more, unless otherwise expressly and specifically defined.

[0062] like Figures 1 to 5 As shown, a photovoltaic module string bonding process includes the following steps:

[0063] S1. Glass plate preparation and adhesive film treatment: Provide a glass plate, cover the upper surface of the glass plate with an adhesive film, and heat the bottom of the glass plate to make the adhesive film melt and adhere.

[0064] S2. Battery cell preparation: Provide finished battery cells coated with insulating adhesive. The finished battery cells are diced into several smaller battery cells. The dicing process is dried to bring the battery cells to an initial temperature.

[0065] S3, Disposable Array Placement: Using a robotic arm equipped with a vision positioning system, multiple battery cells from step S2, which have reached an initial temperature, are simultaneously grasped. During the grasping process, the robotic arm continuously blows hot air onto the grasped battery cells through its heating nozzles to maintain or increase the battery cell temperature. Guided by the vision positioning system, the grasped battery cells are precisely placed onto the adhesive film in the molten adhesive film from step S1 according to a preset array position. The heat of the battery cells promotes their rapid and firm adhesion to the molten adhesive film, thereby fixing the position of the battery cells.

[0066] S4. Welding: Welding wires are laid on the glass plate after the array is completed to connect the cells in the array in series and then laser weld them to form the cell string of the photovoltaic module.

[0067] The principle behind the space optimization of the processing technology of this invention lies in the integration and innovation of the battery cell placement and welding processes. In the glass plate preparation and adhesive film treatment steps, the adhesive film is made in a molten and adhered state, providing conditions for the direct placement and fixing of the battery cells. In the one-time array placement step, a robotic arm is used to directly place the battery cells on the adhesive film, followed by direct welding. Unlike traditional processes, there is no need to weld battery strings in other areas first and then transport and arrange them. This reduces the placement area and the setting of welding station 5, simplifies the equipment layout from a process perspective, and thus reduces the equipment footprint.

[0068] The principle behind the optimized equipment space achieved by the processing technology of this invention lies in the fact that traditional processes involve secondary handling of the battery strings, external forces during robotic gripping, and shaking during movement, which can easily damage the welded positions. The process of this invention changes the operation sequence, fixing the battery cells to the glass plate using the molten adhesion properties of the adhesive film before welding, and then performing welding. This avoids the need for handling the welding positions and eliminates the risk of damage to the welding positions at the source of the operational process.

[0069] The principle behind the improved production efficiency achieved by the processing technology of this invention lies in the following: In the one-time array placement stage, a robotic arm equipped with a vision positioning system simultaneously grasps multiple battery cells. Through the precise guidance of the vision positioning system, rapid and accurate placement is achieved, significantly saving time compared to the traditional method of placing each cell individually. At the same time, the secondary handling and layout waiting stages of the battery strings are eliminated, making the production process more seamless. Laser welding technology has the characteristics of concentrated energy, fast welding speed, and small heat-affected zone, which can quickly complete the series welding of battery cells. The synergistic effect of multiple technologies effectively improves production efficiency.

[0070] Finally, the principle behind the enhanced bonding strength achieved by the processing technology of this invention lies in the following: During the cell preparation step, the drying process in the dicing and segmentation stage brings the cells to an initial temperature. During the one-time array arrangement, the robotic arm continuously blows hot air through its hot air nozzles, ensuring that the cells are at a high temperature when in contact with the adhesive film. High temperature accelerates the movement of molecules on the adhesive film and cell surface, reduces the viscosity of the adhesive film, promotes mutual penetration and diffusion between molecules, and forms stronger intermolecular forces, thereby achieving rapid and strong bonding and enhancing the overall structural strength of the photovoltaic module.

[0071] In this invention, the glass plate preparation process in step S1 specifically includes:

[0072] S101, Receive glass plate through horizontal glass plate transmission line 11;

[0073] S102. Transfer the glass plate to the vertical glass plate transmission line 12, which is perpendicular to the horizontal transmission line;

[0074] The horizontal and vertical glass plate conveyor lines 12 constitute an orderly conveying system. The horizontal glass plate conveyor line 11 is responsible for receiving glass plates and transporting them to designated positions. Through mechanical transmission or other transfer devices, the glass plates are accurately transferred to the vertical glass plate conveyor line 12, which is perpendicular to the horizontal conveyor line. The vertically intersecting conveying layout, by utilizing the conversion of spatial positions, realizes the smooth transition of glass plates between different processes, enabling the glass plates to enter the processes of film covering, heating and melting, and scraping in the predetermined processing order. This avoids the accumulation or misalignment of glass plates caused by chaotic conveying paths, and ensures the continuity and efficiency of the production process.

[0075] S103. At the front end of the vertical transmission line, the adhesive film is covered on the upper surface of the glass plate, and the bottom of the glass plate is heated to 50-120℃ simultaneously to melt the adhesive film. This temperature range allows the adhesive film to reach the optimal melting state, reducing the viscosity of the adhesive film and enhancing its fluidity and plasticity. In this state, the adhesive film can better fill the tiny unevenness on the surface of the glass plate and achieve a tight fit.

[0076] S104. Use a scraper to smooth the molten adhesive film to form a uniform adhesion layer, further eliminating stress and air bubbles inside the adhesive film, increasing the contact area between the adhesive film and the glass plate, thereby improving the adhesion between the two and ensuring that the adhesive film is firmly attached to the glass plate.

[0077] It is evident that the entire glass panel preparation process achieves improved processing precision through precisely designed transmission lines and standardized operating procedures. The refined control of the transmission process and processing operations ensures that the encapsulant treatment effect of each glass panel has a high degree of repeatability and consistency, thereby improving the overall precision of photovoltaic module processing.

[0078] In this invention, the cell preparation process in step S2 includes:

[0079] The finished solar cells are divided into several smaller solar cells using laser scribing.

[0080] When the laser beam is focused onto the surface of the finished solar cell, the instantaneous high temperature causes the cell material to melt and vaporize rapidly, thus achieving cutting. Due to the concentrated energy and small spot diameter of the laser beam, it can perform high-precision micro-machining. During the cutting process, there is no need for direct contact with the solar cell, avoiding the stress and damage caused by friction between the blade and the solar cell during mechanical cutting, thus ensuring the integrity and electrical performance of the solar cell. At the same time, the rapid scanning characteristics of the laser enable it to complete the dicing of a large number of solar cells in a short time, greatly improving cutting efficiency.

[0081] Drying at 80°C for 3 to 10 seconds gives the solar cells an initial temperature of 40°C to 60°C. This, combined with the subsequent continuous blowing of hot air from the robotic arm's hot air nozzle to maintain or increase the temperature, rapidly promotes molecular diffusion and cross-linking reactions between the solar cells and the molten adhesive film when they come into contact. Compared to the case without an initial temperature, this significantly reduces the power required by the robotic arm's hot air nozzle, thus reducing energy consumption. At the same time, the appropriate initial temperature, in synergy with subsequent heating, allows the solar cells to bond with the adhesive film at a better high temperature, effectively reducing bonding time, enhancing bonding strength, and improving the overall performance and stability of the photovoltaic module.

[0082] As can be seen, in step 2, the integrated operation of laser scribing and drying combines the cell division and temperature treatment processes, avoiding material transfer and waiting time between different equipment in traditional processes. This makes the production process more compact and efficient, reduces production stagnation caused by poor process connections, and improves the continuity and efficiency of the entire photovoltaic module production process.

[0083] In this invention, in step S3:

[0084] The robotic arm can simultaneously grasp 4 or 6 battery cells;

[0085] By grabbing multiple solar cells at once, the number of times the robotic arm has to go back and forth to pick up the cells is reduced, thus reducing non-productive time during the cell placement process. With the assistance of the vision positioning system, multiple solar cells can be placed in the preset position quickly and accurately at the same time, which greatly improves the speed of solar cell array placement and thus improves the production efficiency of the entire photovoltaic module string welding process.

[0086] The temperature of the hot air outlet is set to 80℃, and the air velocity is 0.5 to 2m / s;

[0087] During the placement of the battery cells, their surface temperature is maintained at 70°C to 80°C, and the bonding and curing time after contact with the adhesive film is ≤1.0 second.

[0088] The setting of an 80℃ hot air outlet temperature and a wind speed of 0.5 to 2 m / s is based on precise calculations of the required temperature and heat transfer efficiency for bonding the solar cells and the encapsulant film. This effectively transfers heat to the solar cells. Controlling the wind speed within this range ensures that the hot air acts evenly on the surface of the solar cells, maintaining the cell temperature within the ideal range of 70℃ to 80℃, while avoiding excessive heat loss or unnecessary impact on the solar cells due to excessive wind speed. At temperatures between 50℃ and 120℃, the encapsulant film is in a good molten flow state, and the molecular activity on the surface of the solar cells is enhanced. When the two come into contact, the diffusion rate between molecules accelerates, enabling a rapid cross-linking reaction to occur within ≤1.0 seconds, forming a strong bond and ensuring the bonding quality and structural stability of the photovoltaic module.

[0089] In this invention, the visual positioning system in step S3 performs the following operations:

[0090] Establish a coordinate system by identifying the positioning marks at the four corners of the glass plate;

[0091] Real-time correction of battery cell grasping posture deviation;

[0092] The accuracy error of the placement position is controlled to be ≤ ±0.2mm.

[0093] The visual positioning system uses cameras mounted on robotic arms or at specific locations on the production line. Utilizing image recognition technology, it detects and analyzes positioning marks at the four corners of a glass plate. By calculating the coordinates of these marks in the image, it establishes a coordinate system corresponding to the actual physical space. During the placement of the solar cells, the system compares the preset position information of the cells with the actual image coordinates. Based on a coordinate transformation algorithm, it precisely controls the movement distance and direction of the robotic arm, ensuring that the placement posture and position of each solar cell are within strict quality standards, controlling the placement accuracy error to within ≤±0.2mm.

[0094] In this invention, the welding process in step S4 includes:

[0095] The dual-station welding system operates synchronously; each station can independently complete wire laying and laser welding operations. In actual production, the two stations can perform welding operations on different photovoltaic modules separately, achieving parallel processing and doubling welding efficiency.

[0096] Multiple parallel welding wires are laid on the battery cell array using a wire drawing module 51;

[0097] The wire drawing and laying module 51 is a mature existing technology, which can be referenced from the wire laying mechanism of a battery cell string welding machine developed by our company in the early stage (patent publication number CN222776539U). Through the cooperation of the material carrier, wire drawing device and wire cutting device of the wire feeding assembly, the automatic stretching and cutting of the welding wire is realized, which improves the efficiency by more than 50% compared with manual operation. The end wire clamping device and wire clamping and cutting knife combination device of the wire laying assembly can clamp multiple welding wires at the same time and precisely adjust the spacing to ensure that the parallel laying accuracy of the welding wire is ≤±0.1mm, which meets the wire laying requirements of high-density battery cell arrays.

[0098] The laser welding spot length ranges from 10 to 40 mm, and the width ranges from 2 to 8 mm. A long, strip-shaped spot can simultaneously cover multiple parallel weld seams, allowing for the fusion connection of multiple welding wires in a single irradiation. For example, for 12 parallel weld seams spaced 5-20 mm apart, a traditional circular spot requires approximately 36 point-by-point welding operations, while a long, strip-shaped spot only requires 1-2 scans, increasing welding efficiency by over 60% and reducing the welding time for a single component to 8-12 seconds.

[0099] Laser welding is a mature existing technology, and a laser string welding device developed by our company in its early stages (patent publication number CN116833562A) can be referenced. Specifically, the specific steps of laser welding are as follows:

[0100] A pressing mechanism is covered on the surface of the battery cell array with welding wires already laid, so that the parallel heat-conducting medium body accurately presses the weld seam corresponding to multiple parallel welding wires.

[0101] The elongated light spot shines on the heat-conducting medium, and the heat is conducted through the medium to the welding wire to achieve fusion bonding.

[0102] Laser energy is indirectly conducted to the welding wire through a heat-conducting medium, avoiding localized overheating caused by direct laser irradiation of the solar cell. The thermal conductivity of the heat-conducting medium (such as graphite or ceramic) concentrates the temperature in the welding area at the interface between the welding wire and the solar cell (approximately 200-300°C), while the temperature rise in the non-welding area is less than 10°C. This reduces the solar cell breakage rate to below 0.5% and decreases electrical performance degradation by 0.15%.

[0103] The optical path system shapes the circular Gaussian beam emitted by the laser into an elongated strip shape using optical path shaping modules (such as cylindrical mirrors and apertures). The beam length is adjusted by the focal length of the cylindrical mirror (the longer the focal length, the longer the beam), and the width is controlled by the beam divergence angle. A thermally conductive medium (thermal conductivity ≥200 W / (m·K)) is tightly bonded to the surface of the solar cell. When the laser beam irradiates the medium, the energy transfer path is: laser energy → absorption on the surface of the medium → heat conduction to the interface between the medium and the welding wire → melting of the welding wire → metallurgical bonding with the solar cell. This indirect heating mode concentrates heat in the weld area, with a heat diffusion range ≤0.5 mm, avoiding thermal damage caused by direct laser irradiation of the solar cell. Taking graphite as an example, its thermal diffusivity reaches 10... -5 m 2 / s, which can transfer heat to the welding wire within 5ms, enabling rapid welding.

[0104] The present invention also provides a photovoltaic module stringing processing equipment, comprising:

[0105] The glass support plate feeding mechanism 1 is equipped with a glass picking robot 13, which is used to transfer the glass plate with molten adhesive film to the inlet of the string welding processing line.

[0106] The dicing and feeding mechanism 2 is used to provide battery cells with initial temperature;

[0107] The dicing and loading mechanism includes a dicing mechanism and a loading mechanism. The dicing mechanism, also known as a splitting mechanism, is a mature existing technology and can be referenced to the grooving and splitting mechanism of a battery processing equipment developed by our company in its early stages (patent publication number CN218964397U). It has two processes: first, laser is used to make a transverse dicing line in the middle of the battery cell; second, the diced battery cell is split into smaller pieces along the dicing line. The loading mechanism uses a robotic arm to transfer small-area battery cells to the placement table 3.

[0108] The wafer placement table 3 and the wafer placement robot 31 are located at the front end of the string welding processing line and are used to receive the battery cells from the dicing and feeding mechanism 2. The wafer placement robot 31 is equipped with a vision positioning system, and its end effector is equipped with a suction cup for gripping the battery cells and a hot air nozzle located relatively in the middle of the suction cup. The wafer placement robot 31 is configured to grip multiple battery cells at the same time. During the gripping process, hot air is continuously blown onto the battery cells through the hot air nozzle to maintain or increase their temperature. Guided by the vision positioning system, the gripped multiple battery cells are precisely placed on the glass plate with molten adhesive film located at the wafer placement table 3 according to the preset array position.

[0109] The adhesive applicator 4 is used to provide adhesive strips to the glass plate on which the solar cells have been placed and to adhere them to the solar cells.

[0110] Welding station 5 is located after the adhesive application mechanism 4. It has wire drawing modules 51 at both ends for laying welding wire to connect the battery cells in the array and performing laser welding.

[0111] The unloading module 6 and the discharge conveyor belt 61 are used to smoothly remove the welded photovoltaic modules from the welding station 5 and transfer them to the discharge conveyor belt 61 to realize the unloading and output of the modules.

[0112] The glass support plate feeding mechanism 1 realizes the transfer of glass plates, the application of adhesive film, and the pre-treatment of molten adhesive film, providing a substrate for uniform adhesion of solar cells. The glass support plate feeding mechanism 1 includes a horizontal glass plate conveying line 11 and a vertical glass plate conveying line 12. The horizontal glass plate conveying line 11 is arranged parallel to the string welding processing line and is used to transport glass plates to the vertical glass plate conveying line 12. The vertical glass plate conveying line 12 is arranged perpendicular to the horizontal glass plate conveying line 11 and is used to transport glass plates with molten adhesive film to the inlet of the string welding processing line.

[0113] The front end of the vertical glass plate transmission line 12 is provided with an adhesive film attaching device. The adhesive film attaching device is used to cover the glass plate with an adhesive film and heat the bottom of the glass plate to melt and adhere the adhesive film. The adhesive film attaching device is also provided with a scraper for smoothing the adhesive film.

[0114] In one specific embodiment, the horizontal glass plate conveyor line 11 adopts a metal mesh belt or a vacuum adsorption conveyor belt, equipped with a servo motor drive, and photoelectric sensors on both sides detect the position of the glass plates. The horizontal glass plate conveyor line 11 receives upstream glass plates parallel to the string welding processing line (X-axis), and achieves horizontal alignment of the glass plates through positioning baffles and cylinder push blocks. The vertical glass plate conveyor line 12 is perpendicular to the horizontal conveyor line (Y-axis), adopts a ball screw + linear guide module, and is equipped with a vacuum adsorption platform, which can carry large-sized glass plates. The vertical glass plate conveyor line 12 transfers the horizontally conveyed glass plates to the vertical line through a 90° turning mechanism, and conveys them to the string welding inlet along the negative Y-axis direction. The adhesive film roll of the adhesive film application device is installed at the front end of the vertical transmission line, and the tension control mechanism ensures that the adhesive film is spread out flat. The heating unit of the adhesive film application device adopts an infrared heating plate with a heating temperature of 50℃ to 120℃ and a heating time of 10-20 seconds to melt the adhesive film. The elastic metal scraper of the adhesive film application device moves laterally to flatten the adhesive film with a scraper pressure of 5-10N / cm to ensure that the uniformity error of the adhesive film thickness is ≤±5μm and to eliminate bubbles and wrinkles.

[0115] In one specific embodiment, the cell placement stage 3 includes a support platform with a constant-temperature heating plate embedded within it. The mechanical body of the cell placement robot 31 can be a 6-axis industrial robot to meet the requirement of simultaneously grasping 4-6 battery cells. The end effector of the cell placement robot 31 is equipped with a suction cup array, which is configured with several suction cup nozzles for picking up a single battery cell. The end effector of the cell placement robot 31 is also equipped with several hot air vents located at the center of the suction cup nozzles. The airflow speed of the hot air vents is adjustable, and the temperature is 80°C, ensuring that the surface temperature of the battery cells is maintained at 70-80°C during the placement process.

[0116] The visual positioning system on the placement stage 3 consists of a 2D vision camera and a laser displacement sensor, mounted above the placement robot 31. The algorithm flow is as follows: identify the positioning marks at the four corners of the glass plate, establish a world coordinate system through a perspective transformation algorithm; acquire images of the grasped battery cells in real time, calculate the rotation angle and offset, and drive the end effector for fine-tuning through inverse kinematics of the robot; generate the optimal placement trajectory based on the preset array coordinates to avoid collisions between the suction cup and the placed battery cells.

[0117] After the wafer-laying robot 31 picks up the battery cells from the dicing mechanism, the heating air vent is activated simultaneously to maintain the temperature of the battery cells during the movement. After reaching the wafer-laying table 3, the vision system compensates for positioning errors in real time to ensure the accuracy of the wafer-laying position.

[0118] In one specific embodiment, the adhesive applicator 4 adopts an adhesive applicator for battery cells disclosed in patent publication number CN222897491U. The installation position is located between the cell placement table 3 and the welding station 5 of the device of the present invention. The installation direction ensures that the adhesive strips output by the adhesive applicator 4 can accurately cover the gaps or edges of the battery cell array and fit tightly against the upper surface of the battery cell.

[0119] In one optional embodiment, the gripping mechanism of the unloading module 6 employs a vacuum suction robotic arm or pneumatic gripper, using pneumatic drive to grip the components; three-dimensional motion is achieved via linear guides or a multi-axis robotic arm, coupled with servo motor drive, ensuring a smooth unloading process. The discharge conveyor belt 61 receives the photovoltaic modules transferred from the unloading module 6 and transports them along a fixed direction to subsequent processes (such as lamination, EL testing) or the finished product storage area, achieving continuous output of the modules.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A photovoltaic module string welding process, characterized by, The method comprises the following steps: S1, glass plate preparation and adhesive film processing: providing a glass plate, covering an adhesive film on the upper surface of the glass plate, and heating the bottom of the glass plate to make the adhesive film in a molten adhesive state; S2, battery piece preparation: providing a finished product battery piece coated with insulating adhesive, dividing the finished product battery piece into several small-area battery pieces by laser scribing, and drying at a temperature of 80-100°C for 3-10 seconds to obtain an initial temperature of 40-60°C for the battery piece; S3, one-time array piece placement: using a manipulator equipped with a visual positioning system to simultaneously grasp multiple battery pieces with an initial temperature from step S2; during the grasping process, the manipulator continuously blows hot air to the grasped battery pieces through a hot air blowing port arranged thereon to maintain or increase the temperature of the battery pieces; the temperature of the hot air blowing port is 80°C, and the wind speed is 0.5-2 m / s; Using the visual positioning system for guidance, the grasped multiple battery pieces are accurately placed on the adhesive film in the molten adhesive state according to the preset array position in step S1; The surface temperature of the battery piece during the placement process is maintained at 70-80°C, and the bonding solidification time after contacting with the adhesive film is ≤1.0 second; the heat of the battery piece promotes rapid and firm bonding with the molten adhesive film to fix the position of the battery piece; S4, welding: arranging a welding wire on the glass plate on which the array piece placement is completed, connecting the battery pieces in the array in series, and performing laser welding to form a cell string of a photovoltaic module.

2. The photovoltaic module string welding process of claim 1, wherein, The preparation process of the glass plate in step S1 specifically comprises: S101, receiving the glass plate through a horizontal glass plate transmission line; S102, transferring the glass plate to a vertical glass plate transmission line perpendicular to the horizontal transmission line; S103, covering the adhesive film on the upper surface of the glass plate at the front end of the vertical transmission line, and simultaneously heating the bottom of the glass plate to 70-90°C to melt the adhesive film; S104, using a scraper to scrape the molten adhesive film to form a uniform adhesive layer.

3. The photovoltaic module string welding process of claim 1, wherein, In step S3: The manipulator simultaneously grasps 4 or 6 battery pieces.

4. The photovoltaic module string welding process of claim 1, wherein, The visual positioning system of step S3 performs the following operations: Identify the positioning marks at the four corners of the glass plate to establish a coordinate system; Real-time correction of battery piece grasping posture deviation; Control the placement position accuracy error to be ≤±0.2 mm.

5. The photovoltaic module string welding process of claim 1, wherein, The welding process of step S4 comprises: Synchronous operation through a double-station welding system; Using a wire drawing and wire laying module to lay multiple parallel welding wires on the battery piece array; The spot length of laser welding is 10-40 mm, and the width is 2-8 mm.

6. The photovoltaic module string welding process of claim 1 or 5, wherein, The specific steps of laser welding are: Covering a pressing mechanism on the surface of the battery piece array on which the welding wire has been laid to accurately press the heat-conducting medium body arranged in parallel to the welding seam corresponding to the multiple parallel welding wires; The long strip-shaped spot is irradiated on the heat-conducting medium body, and the heat is conducted to the welding wire through the medium body to realize molten connection.

7. A photovoltaic module string welding apparatus, characterized by, Comprise: The glass carrying plate feeding mechanism comprises a horizontal glass plate conveying line and a vertical glass plate conveying line. The horizontal glass plate conveying line is parallel to the string welding processing line and is used to convey the glass plate to the vertical glass plate conveying line. The front end of the vertical glass plate conveying line is provided with a film attaching device. The film attaching device is used to cover the glass plate with a film and heat the bottom of the glass plate to make the film melt and adhere. The film attaching device is also provided with a scraper for scraping the film. The vertical glass plate conveying line is perpendicular to the horizontal glass plate conveying line and is used to convey the glass plate with the melted film to the entrance of the string welding processing line. The slicing and feeding mechanism is used to provide the battery plate with an initial temperature. The plate placing table and the plate placing manipulator are arranged at the front end of the string welding processing line and are used to receive the battery plate from the slicing and feeding mechanism. The plate placing manipulator is provided with a visual positioning system. The end effector of the plate placing manipulator is provided with a suction cup for grabbing the battery plate and a hot air blowing port located at the middle position opposite to the suction cup. The plate placing manipulator is configured to grab multiple battery plates at the same time. During the grabbing process, the hot air blowing port continuously blows hot air to the battery plate to maintain or increase the temperature of the battery plate. The visual positioning system is used to guide the multiple battery plates to be accurately placed on the glass plate with the melted film according to the preset array position. The film attaching mechanism is used to provide the glass plate with the placed battery plate with a film strip segment and attach the film strip segment to the battery plate. The welding station is arranged behind the film attaching mechanism. The front and rear ends of the welding station are provided with wire drawing and distribution modules. The modules are used to distribute the battery plates in the array of the welding wire and perform laser welding. The discharging module and the discharging belt line are used to discharge and output the photovoltaic module after the welding is completed.

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