A solder strip fixing method and a preparation method of a full-screen photovoltaic module

Abstract

The present application relates to the technical field of full-screen photovoltaic module, in particular to a solder strip fixing method and a preparation method of full-screen photovoltaic module. The solder strip fixing method comprises the following steps: adopting a silk screen printing screen to print pressure-sensitive adhesive on a cell to form printed adhesive points; the printed adhesive points form dried adhesive points after drying; and placing a solder strip on the dried adhesive points to fix the solder strip on the cell through the dried adhesive points. The present application adopts a silk screen printing screen to print pressure-sensitive adhesive to form printed adhesive points, so that the production rhythm is faster, the height, shape and flexibility of the adhesive points are increased, and the equipment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of full-screen photovoltaic module technology, and more specifically, to a method for fixing solder ribbons and a method for preparing full-screen photovoltaic modules. Background Technology

[0002] In the current production process of full-screen photovoltaic modules, low-temperature processes are often used. The soldering of the solder ribbon, solder paste and grid lines is carried out in the lamination process. Therefore, the position of the solder ribbon needs to be fixed before lamination. Currently, the commonly used methods for fixing are adhesive dots (UV adhesive, pressure-sensitive adhesive, etc.) and skin coating.

[0003] Currently, pressure-sensitive adhesives are commonly applied to solar cells using mechanical spraying. However, this method limits the shape and position of adhesive dots to straight lines and circles, resulting in poor flexibility. Furthermore, the spraying cycle is typically slow, and the adhesive level is difficult to control through spraying pressure. Additionally, mechanical spraying equipment is expensive.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The primary objective of this invention is to provide a method for fixing solder strips, which uses screen printing to print pressure-sensitive adhesive dots, resulting in a faster production cycle and increased dot height, shape, and flexibility, while also reducing equipment costs. This solves the problems of slow spraying cycle, poor flexibility, and high equipment costs associated with existing mechanical spraying techniques.

[0006] The second objective of this invention is to provide a method for preparing a full-screen photovoltaic module.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: The present invention first provides a method for fixing solder ribbon, comprising the following steps: using a screen printing stencil to print pressure-sensitive adhesive on a battery cell to form printed adhesive dots; the printed adhesive dots are dried to form dried adhesive dots; the solder ribbon is placed on the dried adhesive dots, so that the solder ribbon is fixed to the battery cell by the dried adhesive dots.

[0008] Furthermore, the printing is performed using a single doctor blade and a single ink return blade, and the printing is carried out in an environment with a humidity of 80% to 90%.

[0009] Furthermore, the printing is performed inside a dry-proof protective cover.

[0010] Furthermore, a humidifying device is provided inside the anti-dryness protective cover.

[0011] Furthermore, the humidification device uses water sprayed at a rate of 1500~2000mL / h to maintain the humidity.

[0012] Furthermore, the single scraper includes a scraper blade and a mounting plate disposed above the scraper blade and parallel to and directly connected to the scraper blade. Both ends of the mounting plate along the length direction are respectively connected to baffles. The lower edge of the baffles is flush with the lower edge of the scraper blade, and the angle between the baffles and the plane of the mounting plate is an obtuse angle.

[0013] Furthermore, the obtuse angle is 115°~125°.

[0014] Furthermore, the height of the baffle is 50~57mm.

[0015] Furthermore, the scraper is made of polyurethane.

[0016] Furthermore, the hardness of the scraper is 70~80A.

[0017] Furthermore, the squeegee is a chamfered squeegee, and the chamfer angle of the chamfered squeegee is consistent with the tilt angle of the squeegee relative to the screen printing plate during printing, so that the entire chamfered surface of the chamfered squeegee adheres to the screen printing plate during printing.

[0018] Furthermore, the drying method includes drying.

[0019] Furthermore, the drying temperature is 110~130℃.

[0020] Furthermore, the drying time is 10-20 seconds.

[0021] Furthermore, after the printing and before the drying, the process includes a step of dicing the battery cell with the printed adhesive dots into multiple smaller battery pieces.

[0022] The present invention also provides a method for preparing a full-screen photovoltaic module, which includes the above-mentioned method for fixing the solder strip.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention uses screen printing to print pressure-sensitive adhesive to form printing dots, which increases the production cycle, increases the height, shape and flexibility of the dots, and also reduces equipment costs.

[0024] (2) By using a single scraper and a single ink return method and controlling the humidity of the printing environment, the present invention can ensure that the screen surface is always moist and avoid the pressure-sensitive adhesive drying out and forming an oil film on the screen.

[0025] (3) By controlling the angle between the baffle and the plane of the mounting plate to be obtuse, the present invention can scrape off the remaining glue on both sides of the screen during printing, thereby reducing the proportion of aged glue on the entire screen.

[0026] (4) The present invention uses a low-hardness chamfered polyurethane squeegee, which can make less glue left on the screen after printing. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a front view of a single scraper provided by the present invention; Figure 2 This is a top view of the single scraper provided by the present invention. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0030] Unless otherwise specified, in this invention, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0031] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0032] Unless otherwise specified, in this invention, "one or more" or "at least one" refers to any one, any two, or any two or more of the listed items. "Several" refers to any two or more.

[0033] In a first aspect, the present invention provides a method for fixing solder strips in the production of full-screen photovoltaic modules, comprising the following steps: A screen printing stencil is used to print pressure-sensitive adhesive onto the battery cell, forming printed adhesive dots. The printing position, dot shape, and amount of pressure-sensitive adhesive can be adjusted as needed; this invention does not impose any limitations on these aspects.

[0034] The printed adhesive dots are dried to form dried adhesive dots. The method provided by this invention enables the printing of water-based pressure-sensitive adhesive. The drying process allows the water-soluble structure of the pressure-sensitive adhesive to evaporate, thereby making the adhesive viscous and achieving the effect of bonding the solder ribbon.

[0035] The solder ribbon is placed on the dried adhesive dots, thus fixing the solder ribbon to the battery cell through the dried adhesive dots. This completes the fixing of the solder ribbon.

[0036] This invention employs a screen printing method for producing adhesive dots, resulting in a faster production cycle, increased dot height, shape, and flexibility, and reduced equipment costs. It solves the problems of slow spraying cycle, poor flexibility, and high equipment costs associated with existing mechanical spraying techniques.

[0037] In some specific embodiments, the printing is carried out using a single doctor blade and a single ink return blade, and the printing is carried out in an environment with a humidity of 80% to 90% (e.g., 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%).

[0038] The ink return blade is used to push the pressure-sensitive adhesive back to its starting position after the squeegee finishes printing, forming a continuous pressure-sensitive adhesive film on the screen surface to keep the screen surface moist. This ink return and leveling method ensures that the screen always has a thicker adhesive layer, preventing thinner pressure-sensitive adhesive from drying out on the screen.

[0039] Because pressure-sensitive adhesives are water-soluble, they dry very easily during printing, and the evaporation of moisture can cause the adhesive to dry and form a film on the screen. This invention, by employing a single squeegee and a single return ink blade, and by controlling the humidity of the printing environment, ensures that the screen surface remains constantly moist, preventing the pressure-sensitive adhesive from drying and forming an oil film on the screen. This solves the problem of pressure-sensitive adhesive easily sticking to the screen and forming a thin film.

[0040] In some specific embodiments, the printing is performed inside a protective cover for preventing dryness. This protective cover is equipped with a humidifying device that uses deionized water at a spray rate of 1500-2000 mL / h (e.g., 1500 mL / h, 1600 mL / h, 1700 mL / h, 1800 mL / h, 1900 mL / h, 2000 mL / h) to maintain the humidity. The humidifier and the protective cover together provide a humid environment.

[0041] In some specific embodiments, the single scraper includes a scraper blade and a mounting plate disposed above the scraper blade and parallel to and directly connected to the scraper blade, wherein the mounting plate is used for mounting on the machine base, see [link to relevant documentation]. Figure 1 and Figure 2 As shown, the mounting plate is also connected to baffles at both ends along its length. The lower edge of the baffle is flush with the lower edge of the scraper, and the angle between the baffle and the plane of the mounting plate is an obtuse angle.

[0042] By increasing the opening, that is, making the angle between the baffle and the plane of the mounting plate greater than 90°, forming an obtuse angle (normally a right angle), the residual adhesive on both sides of the screen can be scraped off during printing (reducing the old adhesive remaining on both sides of the screen), thus reducing the proportion of aged adhesive on the entire screen.

[0043] In some specific embodiments, the obtuse angle is 115°~125°, for example 115°, 116°, 117°, 118°, 119°, 120°, 121°, 122°, 123°, 124°, 125°. The height of the baffle is 50~57mm, for example 50mm, 51mm, 52mm, 53mm, 54mm, 55mm, 56mm, 57mm. This facilitates better scraping of residual adhesive around the screen into the printing area during printing and ink return, reducing dry adhesive around the edges.

[0044] In some specific embodiments, the scraper is made of polyurethane. Preferably, the scraper has a hardness of 70~80A, such as 70A, 71A, 72A, 73A, 74A, 75A, 76A, 77A, 78A, 79A, or 80A.

[0045] In some specific embodiments, the squeegee is a chamfered squeegee, and the chamfer angle of the squeegee is consistent with the tilt angle of the squeegee relative to the screen printing plate during printing, so that the entire chamfered surface of the squeegee adheres to the screen printing plate during printing. Using a chamfered squeegee (conventional squeegees are right-angled squeegees without chamfers) makes it less likely for an oil film to form on the screen during printing.

[0046] This invention uses a low-hardness, chamfered polyurethane squeegee, which reduces the amount of glue left on the screen after printing.

[0047] In some specific embodiments, the drying method includes baking.

[0048] In some specific embodiments, the drying temperature is 110~130℃, for example 110℃, 113℃, 115℃, 118℃, 120℃, 122℃, 125℃, 127℃, 130℃.

[0049] In some specific embodiments, the drying time is 10~20s, for example 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s, 20s.

[0050] In some specific embodiments, after the printing and before the drying, the step of dicing the battery cell with the printed adhesive dots into multiple (may be two or more) battery pieces is included.

[0051] In some specific embodiments, the shape of the printed adhesive dots can be dot-shaped, line-shaped, ring-shaped (such as circular ring, square ring, etc.), pattern-shaped (such as triangle, square, rhombus, pentagon, hexagon, letter-shaped, honeycomb-shaped, star-shaped, flower-shaped, etc.), etc., and the present invention does not limit them.

[0052] Secondly, the present invention provides a method for preparing a full-screen photovoltaic module, including a method for fixing solder strips.

[0053] The above-mentioned method of fixing the solder strip is used in the preparation of full-screen photovoltaic modules. It has high production efficiency, increased flexibility, low cost, and broad prospects.

[0054] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0055] Example 1 The method for fixing solder strips in the production of full-screen photovoltaic modules provided in this embodiment includes the following steps: (1) A screen printing stencil is used to print pressure-sensitive adhesive on the battery cell to form printing dots.

[0056] The printing process employs a single squeegee and single return ink blade, and is carried out in an environment with 85% humidity. Printing takes place within a desiccation shield equipped with a humidification device that sprays water at a rate of 1800 mL / h to maintain humidity. The single squeegee consists of a squeegee blade and a mounting plate positioned above and parallel to the squeegee, directly connected to it. Baffles are connected to both ends of the mounting plate along its length, with the lower edge of the baffles flush with the lower edge of the squeegee, and the angle between the baffles and the plane of the mounting plate being 120° (obtuse angle). The baffle height is 53 mm. The squeegee is made of polyurethane with a hardness of 75A. The squeegee is chamfered, with a chamfer angle (60°) consistent with the tilt angle of the squeegee relative to the screen printing plate during printing, ensuring that the entire chamfered surface of the squeegee adheres to the screen printing plate during printing. The printing dots are square in shape.

[0057] (2) The battery cell with the printed adhesive dots is cut into two smaller battery pieces. The printed adhesive dots are then heated and dried to form dried adhesive dots. The drying temperature is 120°C and the drying time is 15 seconds.

[0058] (3) Place the solder ribbon on the drying adhesive dots so that the solder ribbon is fixed to the battery cell through the drying adhesive dots.

[0059] Example 2 The difference between the welding strip fixing method provided in this embodiment and that in embodiment 1 is that the included angle between the plane of the baffle and the mounting plate is 115°.

[0060] Example 3 The difference between the welding strip fixing method provided in this embodiment and that in embodiment 1 is that the included angle between the plane of the baffle and the mounting plate is 125°.

[0061] Example 4 The difference between the welding strip fixing method provided in this embodiment and that in embodiment 1 is that the height of the baffle is 50mm.

[0062] Example 5 The difference between the welding strip fixing method provided in this embodiment and that in embodiment 1 is that the height of the baffle is 57mm.

[0063] Example 6 The difference between the solder ribbon fixing method provided in this embodiment and that in embodiment 1 is that the shape of the printed adhesive dots is star-shaped.

[0064] Comparative Example 1 The difference between the solder ribbon fixing method provided in this comparative example for the production of full-screen photovoltaic modules and Example 1 is that the printing uses a conventional right-angle steel plate scraper (i.e., without chamfer), which is a small-opening (right-angle) baffle (i.e., the angle between the baffle and the plane where the mounting plate is located is 90°), and there is no anti-drying cover and humidification device. No humidification is performed, and the ambient humidity is 40%.

[0065] Comparative Example 2 This comparative example uses mechanical spraying to fix the welding strip. The mechanical spraying is a spot spraying method with a spraying spacing of 9.075 mm, a single piece time of 0.85 s, and 20 spraying points.

[0066] Experimental Example The printing glue dot range, printing time, and maximum supportable printing speed of each embodiment and Comparative Example 1 were statistically analyzed, and the results are shown in Table 1.

[0067] Table 1 Test results for each group

[0068] As can be seen from Table 1, compared with Comparative Example 1, the printing glue dot range of each embodiment is smaller, indicating that the printing is uniform.

[0069] Furthermore, the printing time in each embodiment is longer, which reduces the frequency of cleaning (mechanical spraying methods can easily leave old glue residue on the nozzle after prolonged use; while the printing of this invention ensures that a layer of glue with a thickness of 1-3mm is always present on the printed surface, and the printing is carried out under high humidity conditions, making the surface layer less prone to drying).

[0070] The printing speed of each embodiment is faster, which can increase production.

[0071] In summary, this invention uses screen printing to print pressure-sensitive adhesive dots, resulting in a faster production cycle, increased dot height, shape, and flexibility, and reduced equipment costs.

[0072] Furthermore, by employing a single squeegee and a single return ink blade, and by controlling the humidity of the printing environment, the screen surface can be kept moist at all times, preventing the pressure-sensitive adhesive from drying and forming an oil film that adheres to the screen.

[0073] By controlling the angle between the baffle and the mounting plate to be an obtuse angle, residual adhesive on both sides of the screen can be scraped off during printing, reducing the proportion of aged adhesive on the entire screen. Tests showed that when the angle between the baffle and the mounting plate was obtuse in each embodiment, 3-7 mm of residual adhesive was produced after 1 hour of printing; while when the angle was right-angled, 3-7 mm of residual adhesive was produced in just 10 minutes.

[0074] Using a low-hardness, chamfered polyurethane squeegee results in less adhesive remaining on the screen after printing. Tests in all embodiments showed that with a chamfer angle of 60°, only a 10-20 μm thick adhesive film was produced after 4 hours of printing.

[0075] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for fixing welding strips, characterized in that, Includes the following steps: A screen printing stencil is used to print pressure-sensitive adhesive onto the solar cells, forming printing dots. The printed adhesive dots are dried to form dried adhesive dots; The solder ribbon is placed on the dried adhesive dots, so that the solder ribbon is fixed to the battery cell through the dried adhesive dots.

2. The method for fixing the welding strip according to claim 1, characterized in that, The printing is performed using a single doctor blade and a single ink return method, and the printing is carried out in an environment with a humidity of 80% to 90%.

3. The method for fixing the welding strip according to claim 2, characterized in that, The printing is carried out inside a dry-proof protective cover, which is equipped with a humidification device. The humidification device uses water sprayed at a rate of 1500~2000mL / h to maintain the humidity.

4. The method for fixing the welding strip according to claim 2, characterized in that, The single scraper includes a scraper blade and a mounting plate disposed above the scraper blade and parallel to and directly connected to the scraper blade. Both ends of the mounting plate along the length direction are respectively connected to baffles. The lower edge of the baffle is flush with the lower edge of the scraper blade, and the included angle between the baffle and the plane of the mounting plate is an obtuse angle.

5. The method for fixing the welding strip according to claim 4, characterized in that, At least one of the following conditions must be met: (1) The obtuse angle is 115°~125°; (2) The height of the baffle is 50~57mm.

6. The method for fixing the welding strip according to claim 4, characterized in that, At least one of the following conditions must be met: (1) The scraper is made of polyurethane; (2) The hardness of the scraper is 70~80A; (3) The squeegee is a chamfered squeegee, and the chamfer angle of the chamfered squeegee is consistent with the tilt angle of the squeegee relative to the screen printing plate during printing, so that the entire chamfered surface of the chamfered squeegee is attached to the screen printing plate during printing.

7. The method for fixing the welding strip according to claim 1, characterized in that, The drying method includes baking.

8. The method for fixing the welding strip according to claim 7, characterized in that, The drying temperature is 110~130℃, and the drying time is 10~20s.

9. The method for fixing the welding strip according to any one of claims 1 to 8, characterized in that, After the printing and before the drying, the process further includes a step of dicing the battery cell with the printed adhesive dots into multiple smaller battery pieces.

10. A method for preparing a full-screen photovoltaic module, characterized in that, Including the method for fixing the welding strip as described in any one of claims 1 to 9.

Images