Front and back printing and encapsulation production line and process for solar cells

Abstract

This invention relates to a production line and process for front and back printing and coating of solar cells. The production line includes a front coating device, a stringing device, a flipping device, a back coating device, an EL detection device, and a screening device. On the one hand, this invention shortens the production line length while eliminating the space constraints required for the production line layout, enhancing practicality. Simultaneously, based on the 90° vertical inspection and lateral transfer of the inspection robot, the production line structure is optimized, reducing costs. On the other hand, during the coating process, two scrapers switch between vertical and horizontal positions, and the deformation caused by the two scrapers on the coating mesh plate is relatively eliminated. The adhesive is then repeatedly scraped through the mesh area between the two scrapers, improving the quality and efficiency of the coating process. Simultaneously, the scrapers form a continuous, close-fitting coating process, resulting in uniform adhesive dots and a low probability of deformation of the coating mesh plate. Furthermore, it allows for coating operations anytime and anywhere, and maintains a sufficient amount of adhesive during coating.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic technology, specifically relating to a production line for printing and bonding the front and back sides of solar cells, and also to a process for printing and bonding the front and back sides of solar cells. Background Technology

[0002] Traditional solar cells use metal electrodes on the front and back sides to conduct internal current. These electrodes are divided into main grids and fine grids. The main grid primarily collects the current from the secondary grids and connects them in series, while the fine grids collect photogenerated carriers. As the grid patterns have evolved, specifically 4BB, 5BB, MBB, and SMBB, the main grids have become finer (reducing shading loss and silver loss) and more numerous (ensuring conductivity). 0BB (no main grid) is a further upgrade of SMBB technology, using even finer solder ribbons connected to the fine grids to collect and conduct current. This design significantly reduces the metal shading area of ​​the backsheet, increases the light-receiving area, and thus improves the photovoltaic panel's power generation efficiency. However, since both the main grid and pad points are made of silver, many factories have eliminated pad points after upgrading to busbar-less technology to maximize cost reduction and efficiency. However, this makes it difficult to firmly fix the solder ribbons to the cell. Therefore, it is necessary to apply adhesive at specific points and locations, followed by curing, to connect the solder ribbons in their respective positions.

[0003] Currently, the processing of printing adhesive on the front and back of 0BB type solar cells is basically carried out in an assembly line mode. First, adhesive is applied and cured on the front; then the cells are separated and flipped; finally, adhesive is applied and cured on the back; and the front and back of the cell strings are inspected and screened (pass or fail).

[0004] However, the following defects exist in actual operation:

[0005] 1) The entire production line formed by the above-mentioned stringing of batteries is basically laid out sequentially from beginning to end (mostly using a circular conveyor belt for transportation). Furthermore, due to the inherent length limitations of the battery strings themselves, it is difficult to perform reversing or turning operations. Therefore, the production line is very long.

[0006] It cannot meet the needs of many manufacturers who are unable to lay out their production lines properly due to limited workshop space, thus significantly reducing the practicality of the production line.

[0007] 2) During the adhesive application process (including injection, scraping, and curing), regardless of whether it is front-side or back-side adhesive application, the solar cells are delivered to the adhesive application station using a fixed-point application method. Then, an adhesive application screen (commonly a steel plate) above the application station scrapes the adhesive, squeezing it onto the aligned solar cells below. The solar cells then enter the curing zone to cure the adhesive dots (it should be noted that the adhesive itself has viscosity, so its flowability is relatively poor). However, the steel plate used is relatively thin, generally about 0.1~0.3mm thick, and typically there are at least two solar cells under the steel plate. Therefore, the area formed is at least 350*350mm. 2 This process leads to variations in the contact position during scraping, with the steel plate becoming more prone to deformation towards the center. Furthermore, the scraping force cannot be adjusted adaptively, resulting in uneven adhesive application between the middle and ends. Consequently, the final adhesive strength is uneven. Additionally, the resulting adhesive dots vary in size; excessively large dots can cause microcracks during lamination, while dots that are too small cannot meet the required tensile strength for the welding strip. Moreover, because the scraper has a certain angle, most scraping is unidirectional—that is, after one scraping cycle, the scraper is reset before the next. The deformation caused by unidirectional scraping is also unidirectional, preventing effective compensation of deformation between the steel plates and significantly shortening the steel plate's lifespan. Unidirectional scraping also presents an adhesive injection problem, as adhesive needs to be injected on the moving side of the scraper each time, resulting in low scraping efficiency.

[0008] 3) After the stringing is completed, EL testing is required (the working principle of EL testing is as follows: 1. Excitation process: In a dark environment, a certain voltage is applied to the solar cell, and the application and magnitude of the current are controlled by the excitation circuit. This process excites the electrons inside the solar cell with sufficient energy, thereby emitting electroluminescence. 2. Image capture: Optical equipment such as infrared cameras is used to capture and record the light radiation emitted by the solar cell, forming an image of the solar cell module. These images can clearly show the details inside the solar cell, including potential defects. 3. Defect identification: By analyzing the captured images, defects in the solar cell can be identified, such as microcracks, fragments, broken grids, black chips, black spots, etc. These defects will appear in different forms in the image, such as changes in brightness, shape, size, etc.). Since the battery strings cured on the back are transported horizontally, the battery strings must be at least erected before EL testing. After EL testing, qualified and unqualified products are screened based on the output of the detection conveyor belt. This not only increases the length of the production line, but also requires a corresponding robotic arm structure, further complicating the production line structure and increasing costs. Summary of the Invention

[0009] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide an improved production line for front and back printing and bonding of solar cells. It is mainly used for the production of OBB cell structures.

[0010] This invention also relates to a front and back printing and bonding process for solar cells.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] A front and back printing and stringing production line for solar cells includes a front coating device, a stringing device, a flipping device, a back coating device, an EL detection device, and a screening device. The front coating device includes a first conveyor belt, a front coating unit, and a front curing unit. The back coating device includes a second conveyor belt, a back coating unit, and a back curing unit. The front and back coating units have the same structure, both including a coating trough with a perforated coating plate forming the bottom and a scraping mechanism. In particular,

[0013] The flipping device includes a transfer conveyor belt aligned with the output end of the first conveyor belt and arranged side by side with the second conveyor belt, and a transfer unit that flips the side by side battery cells on the transfer conveyor belt by 180° and transfers them to the second conveyor belt.

[0014] The scraping mechanism includes a double scraper assembly capable of switching between up and down relative states, and a power component for driving the double scraper assembly to reciprocate along the length of the adhesive application mesh plate. The double scraper assembly includes a scraper seat and left and right scraper groups mounted on the scraper seat. The two scrapers of the left and right scraper groups and the adhesive application mesh plate constitute the adhesive injection area. The length of each scraper is greater than the width of the mesh area formed by the mesh on the adhesive application mesh plate. The two scrapers gradually open outward from top to bottom and intersect with the adhesive application mesh plate. During the reciprocating motion of the double scraper assembly, the two scrapers switch between up and down positions, and the deformation caused by the two scrapers on the adhesive application mesh plate is relatively eliminated and the adhesive is kept to reciprocate between the two scrapers and pass through the mesh area twice to perform adhesive scraping.

[0015] The EL detection device includes a detection connecting belt aligned with the second transmission belt, a detection robot located above the detection connecting belt, a detection camera for acquiring images, and an image analysis unit, wherein the detection robot is capable of switching the battery string between vertical and horizontal states with a rotation cycle of 90° around the length direction of the detection connecting belt.

[0016] The screening device includes an NG storage belt and a discharge conveyor belt that are parallel to and located on opposite sides of the detection connecting belt. The detection robot can also move in the width direction of the detection connecting belt to transfer the tested battery strings to the NG storage belt or the discharge conveyor belt to form a screening process.

[0017] According to another specific embodiment and preferred aspect of the invention, both the left and right scraper assemblies include a vertically adjustable lifting part and a scraper mounted on the output end of the lifting part. The lifting part provides power to drive the scraper to move and press against the adhesive applicator mesh plate, ensuring that the scraper remains in contact with the mesh plate throughout a single stroke of the coating process. This dynamic pressing is adjusted in real-time based on the deformation of the adhesive applicator mesh plate. Note that this is a real-time change, not a constant positive pressure, because if positive pressure were always present, it would inevitably increase the deformation rate of the adhesive applicator mesh plate.

[0018] Preferably, the lifting unit includes a main adjuster and an auxiliary adjuster mounted on the scraper seat. The main adjuster drives the scraper to move up and down relative to the adhesive mesh plate for adhering and disengaging. The auxiliary adjuster is mounted between the main adjuster and the scraper and is used to adjust the drive of the scraper to maintain adaptive adhering as the adhesive mesh plate deforms. In some specific embodiments, both the main adjuster and the auxiliary adjuster are telescopic rods, wherein the main adjuster and the auxiliary adjuster share a single power source, and the power source adaptively adjusts the output power of the auxiliary adjuster based on the pressure changes generated by the scraper.

[0019] Preferably, the auxiliary regulator is a telescopic rod controlled by a proportional valve to adjust the power output; the main regulator is used to drive the auxiliary regulator to adjust its up and down movement. Specifically, the telescopic rod is a pneumatic or hydraulic cylinder, and can adaptively adjust the supply ratio according to the proportional valve to provide power that matches the scraper movement to maintain contact with the adhesive applicator mesh plate (in other words, regardless of the position, it maintains dynamic balance in the up and down direction, thus minimizing the deformation rate of the adhesive applicator mesh plate); while the main regulator can use common lifting components (such as: power screw, telescopic cylinder, other linear motion methods).

[0020] Alternatively, both the main and auxiliary adjusters can be telescopic rods, sharing a single power source. This power source adaptively adjusts the auxiliary adjuster's output power based on pressure changes caused by the scraper. Here, the power source can actively change the pressure to adaptively adjust the auxiliary adjuster's output power (in short, maintaining dynamic balance in the vertical force to complete the adhesive application). This method is superior to the elastic pressure created by a spring, as elastic pressure increases the deformation rate of the adhesive applicator mesh. Adaptive adjustment, triggered by the deformation of the mesh itself, results in a smaller deformation rate. In some specific implementations, the telescopic rod is pneumatically or hydraulically driven, and the main and auxiliary adjusters are connected via a proportional valve. The output power of the auxiliary adjuster is adjusted in real-time based on the proportional valve's regulation.

[0021] According to another specific embodiment and preferred aspect of the present invention, during the front-side adhesive application, one of the two scrapers is defined as a scraper blade and the other as an interceptor blade. After the scraper blade completes a single pass of adhesive application, the interceptor blade descends and switches to the scraper blade. The first conveyor belt sends the coated battery cells into the front-side curing unit, and the uncoated battery cells are moved to the adhesive application station to achieve continuous adhesive application.

[0022] Preferably, the two scrapers are tilted to the left and right respectively, with acute angles, and the two tilt angles are equal. Specifically, the tilt angle is 45° to 75°. When scraping glue to the left, the right scraper is selected; when scraping glue to the right, the left scraper is selected. The bottom of each scraper forms a scraper surface, which intersects with the glue application mesh plate. A line-surface contact is formed between the bottom edge of the scraper surface and the glue application mesh plate, and the angle between the scraper surface and the glue application mesh plate is less than the tilt angle. Generally, the angle between the scraper surface and the glue application mesh plate is within 30°. This design facilitates sufficient glue filling of the area, ensuring sufficient glue for scraping and improving the uniformity of glue application. Simultaneously, the line-surface contact not only reduces friction between the scraper and the glue application mesh plate but also creates an optimal glue injection zone between the other parts of the scraper surface and the glue application mesh plate. Therefore, once the glue runs out, whether it is done manually or automatically, the glue needs to be injected into the corresponding glue injection area. At the same time, because the glue has poor fluidity and the scraper is relatively long, the probability of glue leaking out from the scraper is small. Furthermore, even if a small amount of glue leaks out from the end of the scraper, it will not cause glue scraping interference because it is far away from the mesh area.

[0023] According to another specific embodiment and preferred aspect of the present invention, each scraper includes a blade holder and a blade body, wherein the blade body is rotatably mounted on the blade holder about its own length direction, and the blade body includes a connecting part rotatably connected to the blade holder and a blade body detached from the connecting part and having a scraper surface at its bottom. The connecting part limits the tilt angle of the blade body relative to the adhesive application mesh plate by means of an external connector detached from the blade holder.

[0024] According to another specific embodiment and preferred aspect of the invention, the stringing device is located between the first conveyor belt and the intermediate conveyor belt, and divides the battery strings according to a set number of battery cells; and / or, the transfer unit includes a first carrier capable of moving in the left-right direction; a first pick-up hand mounted on the first carrier capable of rotating around the left-right direction with a 180° rotation period and moving up and down; a second carrier capable of moving in the up-down and front-back directions; and a second pick-up hand mounted on the second carrier; and / or, the length of the intermediate conveyor belt is less than the length of the second conveyor belt; and / or, the second conveyor belt is located to the side and above the intermediate conveyor belt at a distance equal to the change in height formed by the flipping of the battery cells. Based on the 180° flipping to achieve front-back switching, and combined with the three-axis movement in the up-down, left-right, and front-back directions, side-by-side battery cells are transferred to the corresponding conveyor belt, completing the adhesive application and curing operations on the front and back of the battery cells in a continuous flow manner.

[0025] Preferably, the first and second picking hands have similar structures, both including a picking arm extending in the left-right direction and multiple negative pressure adsorption heads mounted side-by-side on the picking arm. These multiple negative pressure adsorption heads form an adsorption row, and the negative pressure adsorption heads in the adsorption row simultaneously perform negative pressure adsorption and pressure release to pick up and place the parallel battery cells. The entire row is picked up and placed using negative pressure adsorption, with one battery cell corresponding to one negative pressure adsorption head. Alternatively, one battery cell can correspond to multiple negative pressure adsorption heads (e.g., two, three, or more).

[0026] Furthermore, the first pick-up arm has two adsorption rows, which are installed on the upper and lower parts of the pick-up arm with opposite orientations. In this way, the first pick-up arm only needs to rotate 180° to continuously pick up and place the entire row of battery cells; while the second pick-up arm can pick up the cells from above the first pick-up arm each time, and can unload the battery cells onto the second conveyor belt below without rotating it.

[0027] According to another specific embodiment and preferred aspect of the present invention, the front curing unit and the back curing unit have the same structure, both including a curing unit located above the conveyor belt, and a visual inspection camera is also provided at the conveyor belt exit of each curing unit; and / or, the power assembly includes a power screw, a power nut seat, and a power motor, wherein the power screw extends along the left-right direction; and / or, the front adhesive application device further includes a height adjustment mechanism for driving the front adhesive application unit to adjust the position of the adhesive application mesh plate in the up-down direction; the back adhesive application device has a corresponding height adjustment mechanism. In short, the visual inspection camera can detect whether there is adhesive leakage on the surface of the battery cell; the transmission screw achieves high-precision transmission in the left-right and up-down directions, and a slide rail is used to further improve the stability of the movement; the curing unit can be UV curing, LED curing, or other curing methods.

[0028] In some specific embodiments, the detection connecting belt is located above the NG storage belt and the discharge conveyor belt, wherein the discharge conveyor belt can be adjusted along its own width. An NG storage belt that can extend inwards and outwards from the detection connecting belt is also provided between the NG storage belt and the detection connecting belt. Here, the dual-receiving mode of the storage belt and the storage belt within a limited space facilitates the collection of NG battery strings; simultaneously, the lateral adjustment of the discharge conveyor belt allows for adjustment of the output position, improving the convenience of discharge.

[0029] Furthermore, two front and back printing and bonding production lines are arranged side-by-side within the same frame; these two lines are symmetrically laid out and share an NG storage belt and / or an NG collection belt; the two lines are separated by a temporary storage belt, allowing a robotic arm to transfer NG batteries from the temporary storage belt to the NG storage belt or NG collection belt. This dual-line layout fills in the gaps between the lines and allows for NG collection on the same side for easy processing. Simultaneously, to differentiate between the two lines, the NG storage belt and NG collection belt can each store their own NG products, facilitating quick location of NG items and enabling manual replacement or other operations.

[0030] Another technical solution of the present invention is: a front and back printing and encapsulation process for solar cells, which adopts the above-mentioned front and back printing and encapsulation production line for solar cells, and includes the following steps:

[0031] S1, Frontal rubber crossover

[0032] First, the battery string is fed into the glue application station from the front with the first conveyor belt, and is positioned below the glue application mesh plate. Then, glue is applied to the glue application area so that the glue covers the width of the mesh area.

[0033] Secondly, when scraping the adhesive to the left, select the right-side scraper; when scraping the adhesive to the right, select the left-side scraper. Then, switch between the two scrapers up and down to form a blocking and scraping action. One of the scrapers is defined as the adhesive scraper, and the other as the intercepting blade. The intercepting blade is located on the adhesive application mesh plate, and the adhesive scraper adheres to the mesh plate until the adhesive scraper has scraped the entire mesh area. Then, the intercepting blade moves downward to intercept the adhesive moving forward, and the intercepting blade and the adhesive scraper switch states. Furthermore, the direction of the scraping movement is opposite to the tilt direction of the selected left and right scraper groups, and the scrapers can adjust in real time according to the deformation of the adhesive application mesh plate. The pressure generated during the first pass of the adhesive application process is used to complete the single-pass bonding and scraping. At the same time, the first conveyor belt sends the next batch of batteries to the corresponding adhesive application station. The scraper then switches up and down, and continues to scrape the direction of the scraping motion in the opposite direction to the tilt of the selected left and right scraper groups. The pressure generated by the scraper being able to adjust in real time with the deformation of the adhesive application mesh plate completes the return bonding and scraping. That is, by combining the reciprocating motion to relatively eliminate the deformation caused by the scraper on the adhesive application mesh plate, two scraping processes can be completed in one round trip. After each application, the battery cells enter the front curing unit for UV curing, and the adhesive application position is detected by a vision camera.

[0034] S2, string splitting, front and back flipping

[0035] The battery strings from the first conveyor belt are split at the end, that is, divided according to the set number of battery cells in the battery string. After all the battery strings are located behind the transfer conveyor belt, a flipping device is used to flip them 180° from the front to the back and transfer them to the second conveyor belt. The battery cells from the first conveyor belt enter the transfer conveyor belt, and then the entire row of battery strings is attracted by the synchronous negative pressure of the adsorption row under the first picker on the first carrier. Then, they are flipped 180° upward around the left and right direction so that the back of the battery cells are facing up, and they are moved to the left to align the second picker. Then, the back and forth movement of the second picker attracts the battery strings by negative pressure and transfers them to the second conveyor belt.

[0036] S3, Backside Adhesive

[0037] The same steps as the front-side adhesive application are used to sequentially apply, scrape, and cure the adhesive, and finally it is conveyed out from the second conveyor belt;

[0038] S4, EL detection

[0039] When the battery string moves to the transmission detection belt, the detection robot above applies negative pressure to adsorb it and rotates it 90° around the length of the detection connection belt to stand the battery string upright, so that the battery string faces the detection camera from the front. The detection camera then acquires and analyzes the image.

[0040] S5, Screening

[0041] After analysis, the battery strings are first reset, and then qualified and unqualified batteries are screened based on the analysis results. Qualified battery strings are transferred laterally to the discharge conveyor belt, while unqualified battery strings are transferred laterally to the NG storage belt.

[0042] Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0043] Based on existing battery cell stringing construction methods, the resulting production line is essentially laid out sequentially from beginning to end (usually using a circular conveyor belt). Coupled with the inherent length limitations of the battery strings, reversing or changing direction is difficult. Therefore, the production line is very long, failing to meet the needs of many manufacturers whose workshops are limited by space constraints, significantly reducing its practicality. During the stringing process (including injection, scraping, and curing), regardless of whether it's front-side or back-side application, a fixed-point application method is used to deliver the battery cells to the application station. Then, an application screen (commonly a steel plate) above the application station scrapes the adhesive, squeezing it onto the aligned battery cells below. The battery cells then enter the curing zone for curing. However, the steel plates used are relatively thin, typically around 0.1-0.3mm thick, and generally, there are at least two battery cells under the steel plate. Therefore, the resulting area is at least 350*350mm. 2This leads to variations in the contact position during the coating process. The steel plate is more prone to deformation towards the center, and the coating force cannot be adjusted adaptively, resulting in uneven adhesive application in the middle and at both ends. Consequently, the final adhesive strength is uneven. Furthermore, the resulting adhesive dots vary in size; excessively large dots can cause microcracks during lamination, while excessively small dots cannot meet the required tensile strength for the welding strip. Additionally, because the scraper has a certain angle, most coating is unidirectional—after one coat, it is reset before the next coat. The deformation caused by unidirectional scraping is also unidirectional, preventing effective compensation of deformation between steel plates and significantly shortening the steel plate's lifespan. Unidirectional scraping also presents a problem with adhesive injection, as each injection must be performed on the moving side of the scraper, resulting in low coating efficiency. After the coating is completed, EL testing is required (EL testing works as follows: 1. Excitation process: In a dark environment, a certain voltage is applied to the solar cell, and the application and magnitude of the current are controlled by the excitation circuit. This process enables the solar cell...). 1. Electrons inside the solar cell are excited with sufficient energy, thus emitting electroluminescence. 2. Image capture: Optical equipment such as infrared cameras are used to capture and record the light radiation emitted by the solar cell, forming an image of the solar cell module. These images can clearly show the detailed internal structure of the solar cell, including potential defects. 3. Defect identification: By analyzing the captured images, defects in the solar cell, such as microcracks, fragments, broken grids, black chips, and black spots, can be identified. These defects will appear in different forms in the image, such as changes in brightness, shape, and size. Since the battery strings are horizontally conveyed after back-side curing, they must be at least upright before EL inspection. After EL inspection, qualified and unqualified products are screened based on the output of the inspection conveyor belt. This not only increases the length of the production line but also requires a matching robotic arm structure, further complicating the production line structure and increasing costs. This invention cleverly solves the various shortcomings of the existing structure by comprehensively designing the front and back printing and stringing production line for solar cells.After adopting this production line, the front side is glued first, then the strings are separated and flipped, followed by the back side glued, then EL testing, and finally, based on the EL test results, qualified and unqualified batteries are screened. Therefore, this invention, on the one hand, achieves a continuous production line operation of sequentially glued front and back sides of battery strings by aligning and arranging each conveyor belt, and by directly moving laterally for screening after EL testing, while shortening the production line length. This eliminates the space limitations required for the production line layout and enhances practicality. On the other hand, based on 90° flipping vertical testing, accurate screening can be performed, and the inspection robot can also be used for screening and transfer, optimizing the production line structure and reducing costs. On the one hand, cost; on the other hand, during the glue application process, based on the reciprocating motion of the dual-scraper assembly, the two scrapers switch between up and down positions, and the deformation caused by the two scrapers on the glue application mesh plate is relatively eliminated and the glue is kept to pass through the mesh area twice between the two scrapers, which greatly improves the quality and efficiency of glue application. At the same time, the scrapers form a full-process adhesive application, which not only improves the uniformity of glue drop size, but also reduces the probability of deformation of the glue application mesh plate and extends the life of the glue application mesh plate. In addition, the movable glue injection area can not only perform glue injection operation anytime and anywhere, but also squeeze glue into the corresponding mesh in the mode of maintaining sufficient glue quantity, improving the uniformity of glue application. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the front and back printing and bonding production line for solar cells in this embodiment;

[0045] Figure 2 for Figure 1 Enlarged structural diagram;

[0046] Figure 3 for Figure 2 A schematic diagram of the front gluing device, the stringing device, the flipping device, and the back gluing device;

[0047] Figure 4 for Figure 3 Front view diagram;

[0048] Figure 5 for Figure 3 A schematic diagram of the front-side adhesive application device;

[0049] Figure 6 for Figure 5 Schematic diagram of the middle adhesive application unit;

[0050] Figure 7 for Figure 5 Schematic diagram of the middle scraping adhesive mechanism;

[0051] Figure 8 for Figure 7 Front view diagram;

[0052] Figure 9 for Figure 7 A left-view diagram;

[0053] Figure 10 for Figure 7 Partial structural decomposition diagram;

[0054] Figure 11 for Figure 3 Schematic diagram of the middle stringing device, the flipping device, and the back adhesive application device;

[0055] Figure 12 for Figure 2 Schematic diagram of the EL detection device and screening device;

[0056] Figure 13 for Figure 12 A structural diagram from another perspective;

[0057] Figure 14 for Figure 13 Front view diagram;

[0058] Among them: ① Front adhesive application device; A. First conveyor belt; B. Front adhesive application unit; 1. Adhesive application trough; 10. Adhesive application mesh plate; 10a. Mesh; 2. Scraping mechanism; 20. Double scraper assembly; a. Scraper seat; b. Left and right scraper groups; b1. Lifting part; b10. Main adjuster; b11. Auxiliary adjuster; b2. Scraper; b20. Scraper seat; b21. Scraper body; b210. Connecting part; b211. Scraper body; m. Scraper surface; b22. External part; 21. Power assembly; c, c1. Power screw; d, d1. Power nut seat; e, e1. Power motor; h, h1. Slide rail; 3. Height adjustment mechanism; C. Front curing unit;

[0059] ② Serial splitting device;

[0060] ③ Turning device; G, Transfer conveyor belt; Y, Transfer unit; Y1, First carrier; Y2, First picker; Y3, Second carrier; Y4, Second picker; y1, Picker arm; y2, Negative pressure adsorption head;

[0061] ④ Back-side adhesive application device; D. Second conveyor belt; E. Back-side adhesive application unit; F. Back-side curing unit;

[0062] ⑤ EL detection device; Q, detection connecting belt; S, detection robot; s1, material handling hand; T, detection camera;

[0063] ⑥ Screening device; J, NG storage belt; K, discharge conveyor belt; L, NG storage belt; Z, temporary storage belt;

[0064] P, battery cell; W, frame; X, vision camera. Detailed Implementation

[0065] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0066] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are 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. Therefore, they should not be construed as limitations on this invention.

[0067] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of 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.

[0070] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0071] like Figures 1 to 14 As shown, the front and back printing and stringing production line for solar cells in this embodiment includes a front coating device ①, a stringing device ②, a flipping device ③, a back coating device ④, an EL detection device ⑤, and a screening device ⑥.

[0072] Specifically, the front gluing device ① and the back gluing device ④ have the same structure. The stringing device ② connects the front gluing device ① and the flipping device ③, and after flipping, it directly enters the back gluing device ④. After the stringing is completed, it is subjected to the EL detection device ⑤, and directly screened to one side according to the analysis results.

[0073] In some specific embodiments, the front-side adhesive application device ① includes a first conveyor belt A, a front-side adhesive application unit B, a front-side curing unit C, and a front-side detection unit; the back-side adhesive application device ④ includes a second conveyor belt D, a back-side adhesive application unit E, a back-side curing unit F, and a back-side detection unit. The front-side adhesive application unit B and the back-side adhesive application unit E have the same structure, both including an adhesive application groove 1 with an adhesive mesh plate 10 forming the bottom of the groove, an adhesive scraping mechanism 2, and a height adjustment mechanism 3 that drives the adhesive application groove 1 and the adhesive scraping mechanism 2 to adjust the position of the adhesive mesh plate 10 in the vertical direction; the front-side curing unit C and the back-side curing unit F have the same structure; the stringing device ② uses a stringer to directly string the cells; the flipping device ③ includes a transfer conveyor belt G aligned with the output end of the first conveyor belt A and arranged parallel to the second conveyor belt D, and a transfer unit Y that flips the parallel battery cells on the transfer conveyor belt E by 180° and transfers them to the second conveyor belt D.

[0074] Specifically, regarding the adhesive application, the first conveyor belt A traverses the front adhesive application unit B and the front curing unit C. Each solar cell P on the first conveyor belt A, with its front side facing upwards, passes through the front adhesive application unit B and the front curing unit C. After adhesive application is completed, the front inspection unit performs visual inspection (the visual camera X takes pictures to obtain information). The second conveyor belt D traverses the back adhesive application unit E and the back curing unit F. Each solar cell P on the second conveyor belt D, with its back side facing upwards, passes through the back adhesive application unit E and the back curing unit F. After adhesive application is completed, the back inspection unit performs visual inspection (the visual camera X takes pictures to obtain information).

[0075] In this example, during the specific glue application process, the glue application station is located directly below the glue application tank. The glue application mesh plate 10 forms a fixed-point glue application mesh 10a, and the mesh area formed by the mesh 10a corresponds to two battery cells P. The glue scraping mechanism 2 is installed above the glue application tank 1, and the glue scraping mechanism 2 includes a double scraper assembly 20 that can switch between up and down relative states, and a power assembly 21 that drives the double scraper assembly 20 to reciprocate along the length direction of the glue application mesh plate 10.

[0076] In some specific embodiments, the dual scraper assembly 20 includes a scraper seat a and left and right scraper assemblies b mounted on the scraper seat a. Each left and right scraper assembly b includes a lifting part b1 that can be adjusted up and down, and a scraper b2 mounted on the output end of the lifting part b1 and whose length covers the width of the mesh area of ​​the adhesive application mesh plate 10. At the same time, the two scrapers b2 of the left and right scraper assemblies b gradually open outward from top to bottom, and the opening area and the adhesive application mesh plate 10 form an adhesive injection area. When the scraper b2 contacts the adhesive application mesh plate 10 and moves to apply adhesive, the lifting part b1 can also provide power to drive the scraper b2 to move and press against the adhesive application mesh plate 10 to keep the scraper in full contact with the adhesive application mesh plate 10 during a single stroke of application.

[0077] In some specific embodiments, the lifting unit b1 includes a main adjuster b10 and an auxiliary adjuster b11 mounted on the scraper seat a. The main adjuster b10 drives the scraper b2 to move up and down relative to the adhesive applicator mesh plate 10 to adhere to and disengage. The auxiliary adjuster b11 is mounted between the main adjuster b10 and the scraper b2 and is used to adjust the drive of the scraper b2 to maintain an adaptive fit as the adhesive applicator mesh plate 10 deforms. Here, the auxiliary adjuster acts like a spring, keeping the scraper in contact with the adhesive applicator mesh plate regardless of its deformation. Further, the auxiliary adjuster b11 is a telescopic rod controlled by a proportional valve to adjust the power output; the main adjuster b10 drives the auxiliary adjuster b11 to move up and down for adjustment. Specifically, a telescopic rod is used as a pneumatic or hydraulic cylinder, and the supply ratio can be adaptively adjusted according to the proportional valve to provide power that matches the scraper movement and maintains contact with the adhesive applicator mesh (in other words, maintaining dynamic balance in the vertical direction regardless of position, thus minimizing the deformation rate of the adhesive applicator mesh). The main regulator can use common lifting components (such as: power screw, telescopic cylinder, other linear motion methods). Of course, both the main regulator and the auxiliary regulator can be telescopic rods, where the main regulator and the auxiliary regulator share a power source, and the power source adaptively adjusts the output power of the auxiliary regulator based on the pressure changes caused by the scraper. Here, the power source can actively change the pressure to meet the adaptive adjustment of the auxiliary regulator's output power. The effect formed in this way is better than the elastic pressure formed by a "spring" because elastic pressure increases the deformation rate of the adhesive applicator mesh, while adaptive adjustment is triggered by the deformation of the adhesive applicator mesh itself, resulting in a small deformation rate of the adhesive applicator mesh. That is, pressure is controlled in real time by adjusting the power flow based on the force changes of the scraper to meet the need for uniform adhesive application.

[0078] Specifically, each scraper b2 has a scraper surface m at its bottom, which intersects with the adhesive applicator mesh plate 10, and the bottom edge of the scraper surface m and the adhesive applicator mesh plate 10 form a line-to-surface contact for adhesive application. This line-to-surface contact reduces friction between the scraper and the adhesive applicator mesh plate, and also creates an optimal adhesive application area between the other parts of the scraper surface and the mesh plate. Therefore, once the adhesive runs out, whether manually or automatically, the adhesive can be injected into the corresponding application area. Furthermore, due to the poor flowability of the adhesive and the relatively long scraper, the probability of adhesive leaking from the scraper is low. Even if a small amount of adhesive leaks from the tip of the scraper, it will not interfere with the adhesive application because it is far from the mesh area. Each scraper b2 includes a blade holder b20 and a blade body b21, with the blade body b21 rotatably mounted on the blade holder b20 along its length. In short, its tilt angle is adjustable to meet different operating conditions.

[0079] Furthermore, the blade body b21 includes a connecting part b210 rotatably connected to the blade holder b20, and a blade body b211 detached from the connecting part b210 with a scraper surface m formed at its bottom. The connecting part b210 limits the tilt angle of the blade body b211 relative to the adhesive applicator plate 10 by an external connector b22 detached from the blade holder b20. Furthermore, the blade body b211 gradually narrows from top to bottom on both sides, and the angle formed between the scraper surface m and the adhesive applicator plate 10 is smaller than the tilt angle of the blade body itself. Here, based on the optimal adhesive-containing area formed between the other parts of the tilted scraper surface and the adhesive applicator plate, the scraping is performed more evenly (because the adhesive preferentially fills this area, and scraping is performed with sufficient adhesive as the scraper moves). Meanwhile, the scraper on the left tilts to the right and the scraper on the right tilts to the left, with tilt angles of 45~75° (preferably 50~70°), and the angle formed between the scraper surface m and the adhesive application mesh plate 10 is less than 30°. In this example, the blade holder b20 is provided with three positioning holes, and the external component b22 is a commonly used bolt. After rotating to adjust the angle, the position is limited based on the positioning holes selected by the external component b22, so that its tilt angle is determined.

[0080] Furthermore, the power assembly 21 includes a power lead screw c, a power nut seat d, and a power motor e, wherein the power lead screw c extends in the left-right direction; the height adjustment mechanism 3 has a similar structure to the power assembly 21, having a corresponding power lead screw c1, a power nut seat d1, a power motor e1, and a slide rail h1, wherein the power lead screw c1 extends in the up-down direction. In addition, regardless of whether the movement is horizontal or vertical, the slide rail h matching the power nut seat d can be used for left-right movement guidance; and the slide rail h1 matching the power nut seat d1 can be used for vertical movement guidance.

[0081] The transfer unit Y includes a first carrier Y1 capable of moving in the left-right direction; a first pick-up hand Y2 mounted on the first carrier Y1 capable of rotating 180° around the left-right direction and moving up and down; a second carrier Y3 capable of moving up and down and forward and backward; and a second pick-up hand Y4 mounted on the second carrier Y3. Based on the 180° rotation, the front and back sides are switched. Combined with the three-axis movement in the up-down, left-right, and forward and backward directions, side-by-side solar cells are transferred to the corresponding conveyor belt, completing the adhesive application and curing operations on the front and back sides of the solar cells in a continuous flow.

[0082] The first and second pick-up arms Y2 and Y4 have similar structures, both including a pick-up arm y1 extending in the left-right direction and multiple negative pressure adsorption heads y2 mounted side-by-side on the pick-up arm y1. These multiple negative pressure adsorption heads y2 form an adsorption row, and the negative pressure adsorption heads y2 in the adsorption row simultaneously perform negative pressure adsorption and pressure release to pick up and place the parallel battery cells. Negative pressure adsorption is used for picking up and placing the entire row, with one battery cell corresponding to one negative pressure adsorption head. Of course, one battery cell can also correspond to multiple negative pressure adsorption heads (e.g., 2, 3, or more). Specifically, the first pick-up arm Y2 has two adsorption rows, and the two adsorption rows are mounted on the upper and lower parts of the pick-up arm y1 with opposite orientations. In this way, the first pick-up arm Y2 only needs to rotate 180° to continuously pick up and place the entire row of battery cells; while the second pick-up arm Y4 can pick up cells from above the first pick-up arm Y2 each time, and can unload the battery cell P onto the lower second conveyor belt D without rotating it.

[0083] In this example, the first carrier Y1 is a rectangular frame that slides relative to each other via tracks extending in the left-right direction. A telescopic cylinder extending vertically is mounted on the rectangular frame. The first material handler Y2 is mounted on the moving ends of the two telescopic cylinders; that is, the synchronous extension and retraction of the telescopic cylinders achieves the vertical movement of the first material handler Y2. The flipping of the first material handler Y2 is achieved via a flipping shaft and a flipping motor. Specifically, the end of the material handler Y1 is rotatably mounted on the shaft end via the flipping shaft, and the flipping motor is also mounted on the shaft end. The telescopic rod also acts on the shaft end. The second carrier Y3 has a movable frame that moves vertically, and a rack and gear transmission component that drives the entire movable frame to move laterally in the front-back direction. The second material handler Y4 is mounted on the movable frame.

[0084] Furthermore, the length of the intermediate conveyor belt G is shorter than that of the second conveyor belt D, resulting in a more efficient spatial layout and shortening the overall production line length. Simultaneously, the second conveyor belt D is located to the side and above the intermediate conveyor belt G, at a distance equal to the height change caused by the flipping of the solar cells. This allows the second unloading hand Y4 to simply move back and forth laterally to unload the entire row of solar cells onto the second conveyor belt D.

[0085] The EL detection device ⑤ includes a detection connecting belt Q aligned with the second conveyor belt D, a detection robot S located above the detection connecting belt Q, a detection camera T for acquiring images, and an image analysis unit. The detection robot S can switch the battery string between vertical and horizontal positions by rotating 90° around the length of the detection connecting belt Q. Specifically, the detection robot S itself can move up and down, and a material handling hand s1 with a 90° rotation cycle is located at the bottom of the detection robot S. The structure of the material handling hand s1 is the same as the second material handling hand Y4, and it switches between vertical and horizontal positions during a 90° rotation. Multiple detection cameras T are mounted side-by-side on a frame. In short, the material handling hand s1 also rotates 90° around the left and right directions using its own material handling arm, and then uses a cylinder positioned in the up and down direction for vertical adjustment. Gears and racks (or telescopic cylinders) that move left and right cooperate to achieve forward and backward movement, thereby assisting in screening.

[0086] The screening device ⑥ includes an NG storage belt J and a discharge conveyor belt K located side-by-side with the detection connecting belt Q and on opposite sides of the detection connecting belt Q. The detection robot S can also move in the width direction of the detection connecting belt Q to transfer the detected battery strings to the NG storage belt J or the discharge conveyor belt K for screening. The detection connecting belt is located above the NG storage belt J and the discharge conveyor belt K, wherein the discharge conveyor belt K can be adjusted along its own width direction; an NG storage belt L that can extend inward and outward from the detection connecting belt Q is also provided between the NG storage belt J and the detection connecting belt Q. Here, based on the limited space, the dual receiving mode of the storage belt and the storage belt facilitates the collection of NG battery strings; at the same time, the lateral adjustment of the discharge conveyor belt allows for adjustment of the output position, improving the convenience of discharge.

[0087] Furthermore, for better layout, this example employs two production lines arranged symmetrically to fill the gaps, thus satisfying the requirement of implementing two production lines within a rectangular area. Specifically, the two front and back printing and bonding production lines are arranged side-by-side within the same frame W; the two front and back printing and bonding production lines are symmetrically arranged and share the NG storage belt J and NG storage belt; the two front and back printing and bonding production lines are separated from each other by a temporary storage belt Z, and the inspection robot S can transfer NG battery strings from the temporary storage belt Z to the NG storage belt J or NG storage belt L. Based on the dual-line layout, they can fill each other's space, and NG collection is performed on the same side for convenient processing. At the same time, to distinguish between the two production lines, the NG storage belt and NG storage belt can each store their own NG products, so that the product can quickly find the NG location point, thereby facilitating manual replacement or other operations.

[0088] In summary, the front and back printing and bonding process for solar cells includes the following steps:

[0089] S1, Frontal rubber crossover

[0090] First, the battery string is fed into the glue application station from the front with the first conveyor belt, and is positioned below the glue application mesh plate. Then, glue is applied to the glue application area so that the glue covers the width of the mesh area.

[0091] Secondly, when scraping the adhesive to the left, select the right-side scraper; when scraping the adhesive to the right, select the left-side scraper. Then, switch between the two scrapers up and down to form a blocking and scraping action. One of the scrapers is defined as the adhesive scraper, and the other as the intercepting blade. The intercepting blade is located on the adhesive application mesh plate, and the adhesive scraper adheres to the mesh plate until the adhesive scraper has scraped the entire mesh area. Then, the intercepting blade moves downward to intercept the adhesive moving forward, and the intercepting blade and the adhesive scraper switch states. Furthermore, the direction of the scraping movement is opposite to the tilt direction of the selected left and right scraper groups, and the scrapers can adjust in real time according to the deformation of the adhesive application mesh plate. The pressure generated during the first pass of the adhesive application process is used to complete the single-pass bonding and scraping. At the same time, the first conveyor belt sends the next batch of batteries to the corresponding adhesive application station. The scraper then switches up and down, and continues to scrape the direction of the scraping motion in the opposite direction to the tilt of the selected left and right scraper groups. The pressure generated by the scraper being able to adjust in real time with the deformation of the adhesive application mesh plate completes the return bonding and scraping. That is, by combining the reciprocating motion to relatively eliminate the deformation caused by the scraper on the adhesive application mesh plate, two scraping processes can be completed in one round trip. After each application, the battery cells enter the front curing unit for UV curing, and the adhesive application position is detected by a vision camera.

[0092] S2, string splitting, front and back flipping

[0093] The battery strings from the first conveyor belt are split at the end, that is, divided according to the set number of battery cells in the battery string. After all the battery strings are located behind the transfer conveyor belt, a flipping device is used to flip them 180° from the front to the back and transfer them to the second conveyor belt. The battery cells from the first conveyor belt enter the transfer conveyor belt, and then the entire row of battery strings is attracted by the synchronous negative pressure of the adsorption row under the first picker on the first carrier. Then, they are flipped 180° upward around the left and right direction so that the back of the battery cells are facing up, and they are moved to the left to align the second picker. Then, the back and forth movement of the second picker attracts the battery strings by negative pressure and transfers them to the second conveyor belt.

[0094] S3, Backside Adhesive

[0095] The same steps as the front-side adhesive application are used to sequentially apply, scrape, and cure the adhesive, and finally it is conveyed out from the second conveyor belt;

[0096] S4, EL detection

[0097] When the battery string moves to the transmission detection belt, the detection robot above applies negative pressure to adsorb it and rotates it 90° around the length of the detection connection belt to stand the battery string upright, so that the battery string faces the detection camera from the front. The detection camera then acquires and analyzes the image.

[0098] S5, Screening

[0099] After analysis, the battery strings are first reset, and then qualified and unqualified batteries are screened based on the analysis results. Qualified battery strings are transferred laterally to the discharge conveyor belt, while unqualified battery strings are transferred laterally to the NG storage belt.

[0100] Furthermore, the "blocking and scraping" technique refers to intercepting the adhesive after scraping to prevent it from continuing to move forward due to inertia; scraping refers to the application of the adhesive to cover the entire perforated area of ​​the mesh plate. The phrase "the direction of the scraping movement is opposite to the tilt direction of the selected left and right scraper sets" specifically means: when scraping to the left, the right scraper is selected; when scraping to the right, the left scraper is selected. Preferably, the two scrapers are tilted at acute angles, and the tilt angles are kept equal. Generally, the tilt angle is between 45° and 75°. Through pressure decomposition, part of the pressure forms the pressure to maintain adhesion, and the other part forms the driving force in the direction of movement, thus minimizing the deformation rate of the adhesive perforated plate caused by the scrapers.

[0101] Therefore, this invention, on the one hand, is based on the alignment and side-by-side layout of each conveyor belt, and direct lateral movement for screening after EL detection, to achieve a streamlined operation of sequential glue application on the front and back of the battery string while shortening the production line length. This eliminates the layout space limitations required for the production line, enhancing practicality. Simultaneously, based on 90° vertical flip detection, accurate screening is possible, and the detection robot can also be used for screening and transfer, optimizing the production line structure and reducing costs. On the other hand, during the glue application process, based on the reciprocating motion of the dual scraper assembly, the two scrapers switch between up and down positions, and the deformation caused by the two scrapers on the glue application mesh plate is relatively eliminated and the glue is kept in place, reciprocating between the two scrapers as it passes through the mesh area twice, significantly improving efficiency. The high-quality and efficient scraping of adhesive, along with the continuous application of adhesive by the scraper, not only improves the uniformity of adhesive dots but also reduces the probability of deformation of the adhesive application mesh plate, extending its lifespan. Furthermore, the movable application area allows for application anytime, anywhere, and ensures sufficient adhesive is squeezed into the corresponding mesh openings, improving application uniformity. Thirdly, a 180° rotation enables switching between front and back sides, combined with three-axis motion in the up, down, left, right, and forward / backward directions, transferring side-by-side solar cells to the corresponding conveyor belt for continuous application and curing of the front and back of the cells. Simultaneously, negative pressure adsorption is used for row-by-row loading and unloading, with one negative pressure adsorption head per cell. Of course, it can also be used in combination with other methods. Each solar cell corresponds to multiple negative pressure adsorption heads (e.g., 2, 3, or more); fourthly, the length of the intermediate conveyor belt is shorter than that of the second conveyor belt, resulting in a reasonable spatial layout and shortening the overall production line length; the second conveyor belt is located to the side and above the intermediate conveyor belt at a distance equal to the height change caused by the solar cell flipping, so the second material handler only needs to move back and forth laterally to unload the entire row of solar cells onto the second conveyor belt; fifthly, through the coordinated use of the main regulator and the auxiliary regulator, the auxiliary regulator can adjust the pressure of the scraper on the adhesive mesh plate according to the control of the proportional valve, maintaining a dynamic balance in the vertical direction for adhesive application, thus achieving a better effect than "springy" application. The elastic pressure formed by the "spring" increases the deformation rate of the glue application mesh plate. Adaptive adjustment is triggered by the deformation of the glue application mesh plate itself, resulting in a small deformation rate. Sixthly, through line-surface contact, not only is the friction between the scraper and the glue application mesh plate reduced, but the other parts of the scraper surface and the glue application mesh plate form the optimal glue injection area. Therefore, once there is no glue, whether it is manual or automatic, the glue needs to be injected into the corresponding glue injection area. At the same time, due to the poor fluidity of the glue and the long scraper, the probability of glue leaking out of the scraper is small. Furthermore, even if a small amount of glue leaks out from the end of the scraper, it will not cause glue scraping interference because it is far away from the mesh area.The seventh aspect is based on the optimal adhesive-containing area formed between the other parts of the inclined scraper surface and the adhesive application mesh plate, which allows for more uniform scraping (because the adhesive preferentially fills this area, and scraping is carried out with sufficient adhesive as the scraper moves); the eighth aspect is that the left scraper is inclined to the right and the right scraper is inclined to the left. When scraping to the left, the right scraper is selected; when scraping to the right, the left scraper is selected. This further explains and refines the meaning of "the direction of scraping movement is opposite to the tilt direction of the selected left and right scraper groups". At the same time, the tilt angles of the two scrapers are acute angles and the tilt angles are kept equal, generally between 45 and 75 degrees. Through the decomposition of pressure, part of it forms the pressure to maintain adhesion, and the other part forms the power in the direction of movement, so that the deformation rate of the adhesive application mesh plate caused by the scraper is small; the ninth aspect is based on the transmission screw arranged in the left and right directions. The system employs a reciprocating drive with height adjustment via a vertically oriented transmission screw, offering ease of implementation, high motion precision, and convenient control. The front and back curing units share the same structure, both including a curing unit located above the conveyor belt. This curing unit can utilize UV ​​curing, LED curing, or other curing methods to suit various molding processes. Furthermore, within a limited space, a dual-receiving mode for the storage belt and feed belt facilitates the collection of NG battery strings. Simultaneously, the lateral adjustment of the discharge conveyor belt allows for output position adjustment, improving discharge convenience. Moreover, the dual-line layout allows for mutual space filling, and NG collection is performed on the same side for convenient processing. Additionally, to differentiate between the two production lines, the NG feed belt and feed belt can each store their own NG products, enabling quick location of NG points and facilitating manual replacement or other operations.

[0102] The present invention has been described in detail above, with the aim of enabling those skilled in the art to understand and implement the invention. However, this description should not be construed as limiting the scope of protection of the invention. All equivalent changes or modifications made in accordance with the spirit and essence of the invention should be included within the scope of protection of the invention.

Claims

1. A front and back printing and stringing production line for solar cells, comprising a front coating device, a stringing device, a flipping device, a back coating device, an EL detection device, and a screening device. The front coating device includes a first conveyor belt, a front coating unit, and a front curing unit. The back coating device includes a second conveyor belt, a back coating unit, and a back curing unit. The front and back coating units have the same structure, each including a coating trough with a perforated coating plate forming the bottom and a scraping mechanism. The production line is characterized in that: The flipping device includes a transfer conveyor belt aligned with the output end of the first conveyor belt and arranged side by side with the second conveyor belt, and a transfer unit that flips the side by side battery cells on the transfer conveyor belt by 180° and transfers them to the second conveyor belt. The scraping mechanism includes a double scraper assembly capable of switching between up and down relative states, and a power component for driving the double scraper assembly to reciprocate along the length of the adhesive application mesh plate. The double scraper assembly includes a scraper seat and left and right scraper groups mounted on the scraper seat. The two scrapers of the left and right scraper groups and the adhesive application mesh plate constitute the adhesive injection area. The length of each scraper is greater than the width of the mesh area formed by the mesh on the adhesive application mesh plate. The two scrapers gradually open outward from top to bottom and intersect with the adhesive application mesh plate. During the reciprocating motion of the double scraper assembly, the two scrapers switch between up and down positions, and the deformation caused by the two scrapers on the adhesive application mesh plate is relatively eliminated and the adhesive is kept to reciprocate between the two scrapers and pass through the mesh area twice to perform adhesive scraping. The EL inspection device includes an inspection connecting belt aligned with the second conveyor belt, an inspection robot located above the inspection connecting belt, an inspection camera for acquiring images, and an image analysis unit, wherein the inspection robot can switch the battery string between vertical and horizontal states with a rotation cycle of 90° around the length direction of the inspection connecting belt. The screening device includes an NG storage belt and a discharge conveyor belt that are parallel to and located on opposite sides of the detection connection belt. The detection robot can also move in the width direction of the detection connection belt to transfer the tested battery strings to the NG storage belt or the discharge conveyor belt to form a screening process.

2. The front and back printing and encapsulation production line for solar cells according to claim 1, characterized in that: The left and right scraper assemblies each include a lifting part that can be adjusted up and down, and a scraper installed at the output end of the lifting part. The lifting part can provide power to drive the scraper to move and press against the adhesive mesh plate so that the scraper is in contact with the adhesive mesh plate throughout the single-pass scraping process.

3. The front and back printing and encapsulation production line for solar cells according to claim 2, characterized in that: The lifting unit includes a main adjuster and an auxiliary adjuster mounted on the scraper seat. The main adjuster is used to drive the scraper to move up and down relative to the adhesive mesh plate to adhere and disengage. The auxiliary adjuster is mounted between the main adjuster and the scraper and is used to adjust the drive of the scraper to maintain adaptive adhesion as the adhesive mesh plate deforms.

4. The front and back printing and encapsulation production line for solar cells according to claim 3, characterized in that: Both the main regulator and the auxiliary regulator are telescopic rods, wherein the main regulator and the auxiliary regulator share a power source, and the power source adaptively adjusts the output power of the auxiliary regulator based on the pressure changes formed by the scraper; and / or, the auxiliary regulator is a telescopic rod controlled by a proportional valve to adjust the power output, and the main regulator is used to drive the auxiliary regulator to adjust up and down.

5. The front and back printing and bonding production line for solar cells according to claim 1, characterized in that: During the front-side adhesive application, one of the two scrapers is defined as a scraper blade and the other as an interceptor blade. After the scraper blade completes a single pass, the interceptor blade descends and switches back to the scraper blade. The first conveyor belt delivers the coated battery cells into the front-side curing unit, and uncoated battery cells are moved to fill the gap at the coating station. And / or, the two scrapers tilt to the left and right respectively, where the tilt angle is an acute angle and the two tilt angles remain equal.

6. The front and back printing and encapsulation production line for solar cells according to claim 5, characterized in that: The tilt angle is 45~75°, and when scraping glue to the left, the right-side scraper is selected; when scraping glue to the right, the left-side scraper is selected; and / or, the bottom of each scraper forms a scraper surface, wherein the scraper surface intersects with the glue application mesh plate, and the scraper surface and the glue application mesh plate form a line-surface contact for scraping glue, and the angle between the scraper surface and the glue application mesh plate is less than the tilt angle.

7. The front and back printing and encapsulation production line for solar cells according to claim 1, characterized in that: Each of the aforementioned scrapers includes a scraper holder and a scraper body, wherein the scraper body is rotatably mounted on the scraper holder about its own length. The scraper body includes a connecting part rotatably connected to the scraper holder and a scraper body that is detached from the connecting part and has a scraper surface at its bottom. The connecting part limits the tilt angle of the scraper body relative to the adhesive application mesh plate by means of an external connector that is detached from the scraper holder.

8. The front and back printing and encapsulation production line for solar cells according to claim 1, characterized in that: The battery string splitting device is located between the first conveyor belt and the intermediate conveyor belt, and divides the battery strings according to a set number of battery cells; and / or, the transfer unit includes a first carrier frame that can move in the left-right direction; a first pick-up hand mounted on the first carrier frame that can rotate around the left-right direction with a rotation period of 180° and move up and down; and a second carrier frame that can move in the up-down and front-back directions. and a second material handling hand mounted on the second carrier; and / or, the length of the transfer conveyor belt is less than the length of the second conveyor belt; and / or, the second conveyor belt is located above the side of the transfer conveyor belt at a distance equal to the change in height formed by the flipping of the battery cells.

9. The front and back printing and encapsulation production line for solar cells according to claim 8, characterized in that: The first and second picking hands have similar structures and both include a picking arm extending in the left-right direction and multiple negative pressure adsorption heads mounted side by side on the picking arm. The multiple negative pressure adsorption heads form an adsorption row, and the negative pressure adsorption heads of the adsorption row simultaneously perform negative pressure adsorption and pressure release to pick up and put in the parallel battery cells.

10. The front and back printing and encapsulation production line for solar cells according to claim 9, characterized in that: The first picking arm has two adsorption rows, and the two adsorption rows are installed on the upper and lower parts of the picking arm with opposite orientations.

11. The front and back printing and encapsulation production line for solar cells according to claim 1, characterized in that: The front curing unit and the back curing unit have the same structure, both including a curing unit located above the conveyor belt, and each curing unit is also equipped with a visual inspection camera at the conveyor belt outlet; and / or, the power assembly includes a power screw, a power nut seat, and a power motor, wherein the power screw extends in the left-right direction; and / or, the front adhesive application device also includes a height adjustment mechanism for driving the front adhesive application unit to adjust the position of the adhesive application mesh plate in the up-down direction; the back adhesive application device has a corresponding height adjustment mechanism.

12. The front and back printing and encapsulation production line for solar cells according to claim 1, characterized in that: The detection connecting belt is located above the NG storage belt and the discharge conveyor belt, wherein the discharge conveyor belt can be adjusted along its own width direction; an NG storage belt that can extend inward and outward from the detection connecting belt is also provided between the NG storage belt and the detection connecting belt.

13. The front and back printing and encapsulation production line for solar cells according to claim 12, characterized in that: The two front and back printing and bonding production lines are arranged side by side in the same frame; the two front and back printing and bonding production lines are symmetrically arranged and share an NG storage belt and / or an NG storage belt; the two front and back printing and bonding production lines are separated from each other by a temporary storage belt, and the inspection robot can transfer the NG batteries on the temporary storage belt to the NG storage belt or the NG storage belt.

14. A front and back printing and bonding process for solar cells, characterized in that: It employs the front and back printing and encapsulation production line for solar cells according to any one of claims 1 to 13, and includes the following steps: S1, Frontal rubber crossover First, the battery string is fed into the glue application station from the front with the first conveyor belt, and is positioned below the glue application mesh plate. Then, glue is applied to the glue application area so that the glue covers the width of the mesh area. Secondly, when scraping the adhesive to the left, select the right-side scraper; when scraping the adhesive to the right, select the left-side scraper. Then, switch between the two scrapers up and down to form a blocking and scraping motion. One of the scrapers is defined as the adhesive scraper, and the other as the interceptor. The interceptor is located on the adhesive application mesh plate, and the adhesive scraper adheres to the mesh plate until the adhesive scraper has scraped the entire mesh area. Then, the interceptor moves downward to intercept the adhesive moving forward, and the interceptor and adhesive scraper switch states. Furthermore, the direction of the scraping movement is opposite to the tilt direction of the selected left and right scraper sets, and the scraper can follow the adhesive application mesh. The single-pass bonding and adhesive application is completed by adjusting the pressure in real time according to the deformation of the plate. At the same time, the first conveyor belt sends the next batch of batteries to the corresponding adhesive application station. The scraper then switches up and down and continues to apply adhesive in the opposite direction of the scraping motion and the tilt direction of the selected left and right scraper groups. The return bonding and adhesive application is completed by adjusting the pressure in real time according to the deformation of the adhesive application mesh plate. That is, by combining the reciprocating motion to relatively eliminate the deformation of the adhesive application mesh plate caused by the scraper, two adhesive applications can be completed in one round trip. After each adhesive application, the battery cell enters the front curing unit for UV curing. S2, string splitting, front and back flipping The battery strings from the first conveyor belt are split at the end, that is, divided according to the set number of battery cells in the battery string. After all the battery strings are located behind the transfer conveyor belt, a flipping device is used to flip them 180° from the front to the back and transfer them to the second conveyor belt. The battery cells from the first conveyor belt enter the transfer conveyor belt, and then the entire row of battery strings is attracted by the synchronous negative pressure of the adsorption row under the first picker on the first carrier. Then, they are flipped 180° upward around the left and right direction so that the back of the battery cells are facing up, and they are moved to the left to align the second picker. Then, the back and forth movement of the second picker attracts the battery strings by negative pressure and transfers them to the second conveyor belt. S3, Backside Adhesive The same steps as the front-side adhesive application are used to sequentially apply, scrape, and cure the adhesive, and finally it is conveyed out from the second conveyor belt; S4, EL detection When the battery string moves to the transmission detection belt, the detection robot above applies negative pressure to adsorb it and rotates it 90° around the length of the detection connection belt to stand the battery string upright, so that the battery string faces the detection camera from the front. The detection camera then acquires and analyzes the image. S5, Screening After analysis, the battery strings are first reset, and then qualified and unqualified batteries are screened based on the analysis results. Qualified battery strings are transferred laterally to the discharge conveyor belt, while unqualified battery strings are transferred laterally to the NG storage belt.

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