Device, system and process method for tinning photovoltaic solder strip

Abstract

The invention belongs to the technical field of solder strip manufacturing, and relates to a device for tinning a photovoltaic solder strip, and a system and a process method thereof. Comprising a floating die for primary sizing and an annular air knife for secondary sizing, a first tangent point of a wire pressing plate in the vertical direction and an annular air opening focus point of the annular air knife are located on the same vertical line, and the floating die is located between the first tangent point and the annular air opening focus point; a lifting tin furnace is arranged below the wire pressing plate, a photovoltaic welding strip is pressed into tin liquid in the lifting tin furnace through the wire pressing plate, the average density of the floating die is smaller than that of the tin liquid, airflow of the annular air opening does not cause splashing of a small amount of the tin liquid, die blocking, scalding and other conditions are not likely to be caused, size fluctuation is small, and production efficiency is high. The size of a finished product can be controlled, and the size consistency of the product is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of soldering strip manufacturing, and relates to a device for tinning a photovoltaic soldering strip, a system and a process method thereof. Background Art

[0002] In the photovoltaic industry, there are two main ways to produce photovoltaic ribbons: electroplating and hot-dip plating. Among them, electroplating has a higher cost and a smaller market share in the photovoltaic industry. The mainstream hot-dip plating has a lower cost and a simpler process, which has an absolute advantage in the photovoltaic industry. In the production process of hot-dip plating, tinning is the core process; the tinning process affects important indicators such as the coating thickness, finished product size, and product surface quality of photovoltaic ribbon products; currently, in the production of hot-dip photovoltaic circular ribbons, the industry generally adopts the annular air knife method, that is, a circle of uniform airflow is formed on the entire circumference of the round copper wire, and the gas is used to wipe to form a photovoltaic ribbon with a consistent coating.

[0003] In today's market, new technologies for photovoltaic modules are constantly emerging, and fine round welding ribbons SMBB and 0BB have become the main force. As the specifications of photovoltaic welding ribbons continue to decrease, major manufacturers usually compensate for the loss of production capacity by increasing production speed. However, after the speed is increased, the amount of tin on the copper wire increases, and wiping off the excess tin solution puts a lot of pressure on the current air knife. Common air knife blockages and micro-bamboo nodes on the tin layer of the product affect product output and finished product quality. Specifically, the splashing tin alloy liquid will gradually accumulate and adhere to the lower surface of the air knife lower die and the inner hole wall, and will accumulate for a long time to form a blockage, which cannot work continuously and stably. The splashing tin alloy liquid again poses certain safety hazards and can easily splash onto the operator's arms and other places, posing a risk of scalding; secondly, when the air flow pressure at the air outlet is high, the tin alloy liquid splashes, causing the liquid level of the tin furnace to fluctuate, and the size of the products formed by wind knife wiping fluctuates greatly, and the appearance is not smooth and resembles miniature bamboo nodes; thirdly, during the wind knife tinning process, the tin ash floating on the upper surface of the tin liquid will keep moving. As the number increases, if it is not cleaned in time, it will adhere to the surface of the upwardly pulled soldering ribbon, causing surface quality problems; fourthly, with single-mold tinning, the existing product specifications are getting smaller and smaller. Although the mold center can accurately control the amount of tin, during the tinning process, with the continuous accumulation of copper powder and flux residues on the inner wall of the center hole, the size of the finished product will gradually become smaller and needs to be cleaned or repaired in time.

[0004] Moreover, a Chinese invention patent with the application number 202011376698.9 and the publication number CN112501534B discloses a tin plating die for double-layer photovoltaic special-shaped solder strips, including a first annular die sleeve, a first die core, a second annular die sleeve, and a second die core; the first die core is arranged inside the first annular die sleeve, and the second die core is arranged inside the second annular die sleeve; the first annular die sleeve is located below the second annular die sleeve; the first annular die sleeve and the second annular die sleeve are fixedly connected by a plurality of connecting blocks evenly distributed along the circumferential direction, and a side tin flow port is formed between adjacent connecting blocks; a scraping hole is opened in the center of the first die core, and a sizing hole with the same size and shape as the scraping hole is opened in the center of the second die core; the bottom end surface of the first die core is recessed inward to form a conical scraping area. The thickness of the tin layer is controlled by the die, but the organic matter of the residual flux during the tin plating process is easily adhered around the die hole, blocking the die and causing the copper wire diameter to gradually decrease, which is difficult to clean and not suitable for long-term use. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and propose a device, a system, and a process method for tin plating of photovoltaic solder strips.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention provides a device for tin plating of photovoltaic solder strips, including a frame, on which a pressing plate adjusting seat and an air knife adjusting seat are arranged. The pressing plate adjusting seat is connected with a fixing plate, and a pressing plate is arranged at the lower end of the fixing plate;

[0008] It further includes a floating die for primary sizing and an annular air knife for secondary sizing. The first tangent point of the pressing plate in the vertical direction and the focusing point of the annular air outlet of the annular air knife are located on the same vertical line, and the floating die is located between the first tangent point and the focusing point of the annular air outlet;

[0009] A lifting tin furnace is arranged below the pressing plate. The photovoltaic solder strip is pressed by the pressing plate into the tin liquid in the lifting tin furnace, and the average density of the floating die is less than the average density of the tin liquid.

[0010] Furthermore, the floating die includes an upper die and a lower die, and the upper die and the lower die are screwed together; the upper die includes a first ring, a conical die core is arranged inside the first ring, an upper die hole is arranged in the center of each conical die core, and the conical die core is connected to the inner wall of the first ring through a plurality of upper die rib strips, and there is a hollow between every two upper die rib strips; the lower die includes a second ring, a central ring is arranged in the center of the second ring, and the central ring is connected to the inner wall of the second ring through a plurality of lower die rib strips, and there is a hollow between every two lower die rib strips.

[0011] Further, let the angle between every two upper die rib strips be D, then 45° ≤ D ≤ 90°.

[0012] Further, let the inner diameter of the upper die hole be G, then 1 mm ≤ G ≤ 2 mm.

[0013] Further, the inner diameter of the ring hole of the central ring is smaller than the inner diameter of the upper die hole.

[0014] Further, the upper surface of the conical die core is a conical surface, and the inside of the conical die core is a conical cavity.

[0015] Further, let the cone angle of the conical surface be F, and let the cone angle of the conical cavity be E, then 60° ≤ E = F ≤ 90°.

[0016] Further, both the wire pressing plate adjusting seat and the air knife adjusting seat are XY platforms.

[0017] Further, a lifting screw rod is arranged below the lifting tin furnace.

[0018] The present invention also provides a system based on a device for tin plating of photovoltaic solder tapes, which is characterized in that it includes a flux support cabinet, a flux storage area is arranged in the flux support cabinet, and the flux storage area is inclined;

[0019] A traction guide wheel is arranged on the frame, the traction guide wheel is located above the annular air knife, and the second tangent point and the first tangent point of the traction guide wheel in the vertical direction and the focus point of the annular air outlet of the annular air knife are on the same vertical line;

[0020] Two rows of cooling fans are arranged between the traction guide wheel and the annular air knife, and the photovoltaic solder tape passes between the two rows of cooling fans;

[0021] The photovoltaic solder tape sequentially passes through the flux storage area, the wire pressing plate, the floating die, the annular air knife, the cooling fans, and the traction guide wheel.

[0022] The present invention also provides a process method for a tin plating system, which specifically includes the following steps:

[0023] Step 1: Pass the photovoltaic solder tape through the flux storage area so that the outer surface of the photovoltaic solder tape adheres to the flux;

[0024] Step 2: Press the photovoltaic solder tape with the flux adhered to its outer surface into the tin liquid in the lifting tin furnace through the wire pressing plate;

[0025] Step 3: Perform primary sizing through the floating die and then perform secondary sizing through the annular air knife;

[0026] Step 4: The photovoltaic solder tape is cooled by the cooling fans and then moves along with the traction guide wheel.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The floating mold can limit the amount of tin on the surface of the photovoltaic ribbon. The amount of tin controlled by the floating mold is slightly greater than the thickness requirement of the product coating. In the process of upward traction, the center of the floating mold swims around the photovoltaic ribbon, forming a uniform and consistent tin column between the floating mold outlet and the annular air outlet. The tin column will never cause a huge eccentricity. At the same time, after the amount of tin attached is limited, it becomes easier to wipe the airflow at the air outlet, and the required pressure becomes smaller. The coating size fluctuation of the product formed by wind knife wiping is small, and the appearance is smooth, which is conducive to the control of the finished product size. The consistency of product size is guaranteed, ensuring product quality and output.

[0029] 2. After the tin column between the upper outlet of the floating mold and the annular tuyere is wiped by the annular air knife, the excess tin liquid flows back to the tin furnace along the conical surface of the floating mold and will not gather on the floating mold; the airflow of the annular tuyere will not cause a small amount of tin liquid to splash, and it is not easy to cause mold blockage and scalding.

[0030] 3. In normal production, the floating mold floats on the liquid surface of the tin furnace. The upper surface and the conical tin outlet of the floating mold are higher than the liquid level. The tin liquid is brought upward from the central mold hole by the copper wire from the lower surface inlet of the floating mold. The tin ash and other impurities floating on the liquid surface of the tin furnace are separated and will not enter the tin outlet of the floating mold, which is not easy to cause mold blockage, greatly reducing the cleaning process and improving work efficiency.

[0031] 4. When the trace copper powder and flux residues on the surface of the photovoltaic welding ribbon pass through the floating mold, the lower mold hole (i.e., the ring hole of the center ring) is smaller than the upper mold hole. During the vertical upward traction process, the floating mold is in a floating state and is easy to swim. If the photovoltaic welding ribbon contacts the floating mold, it will only contact the lower mold hole, and the contact time is extremely short. The lower mold hole is immersed in the tin liquid and does not affect the tin amount of the upper mold hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0034] Figure 1 The process route diagram of tinning of photovoltaic welding strip in the present invention;

[0035] Figure 2Schematic diagram of the threading position of the device for tin plating of photovoltaic solder tapes in the present invention;

[0036] Figure 3 Schematic diagram of the working position of the device for tin plating of photovoltaic solder tapes in the present invention;

[0037] Figure 4 Schematic diagram of the upper die structure in the present invention;

[0038] Figure 5 Cross-sectional view of the upper die structure in the present invention;

[0039] Figure 6 Schematic diagram of the inner diameter and taper angle of the upper die hole in the present invention;

[0040] Figure 7 Schematic diagram of the floating die immersed in tin in the present invention;

[0041] Figure 8 Overall schematic diagram of the upper die structure in the present invention;

[0042] Figure 9 Overall schematic diagram of the lower die structure in the present invention.

[0043] Wherein: 1 is the frame; 2 is the pressure plate adjusting seat; 3 is the air knife adjusting seat; 4 is the fixing plate; 5 is the annular air knife; 6 is the floating die; 6-1 is the upper die; 6-11 is the first ring; 6-12 is the tapered die core; 6-13 is the upper die hole; 6-14 is the upper die rib strip; 6-2 is the lower die; 6-21 is the second ring; 6-22 is the central ring; 6-23 is the lower die rib strip; 7 is the tin liquid; 8 is the lifting tin furnace; 9 is the lifting screw; 10 is the guiding pulley; 11 is the cooling fan; 12 is the photovoltaic solder tape; 13 is the flux storage area; 14 is the pressure plate; A is the second tangent point; B is the focus of the annular air outlet; C is the first tangent point. Detailed implementation method

[0044] Here, the exemplary embodiments will be described in detail. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present invention. On the contrary, they are only examples of the devices consistent with some aspects of the present invention detailed in the appended claims.

[0045] Embodiment

[0046] As Figures 1-9 shown, a device for tin plating of photovoltaic solder tapes includes a frame 1, a pressure plate adjusting seat 2 and an air knife adjusting seat 3 are arranged on the frame 1, the pressure plate adjusting seat 2 is connected with a fixing plate 4, and a pressure plate 14 is arranged at the lower end of the fixing plate 4;

[0047] It also includes a floating die 6 for primary sizing and an annular air knife 5 for secondary sizing. The first tangent point of the wire pressing plate 14 in the vertical direction and the focus point of the annular air outlet of the annular air knife 5 are located on the same vertical line. The floating die 6 is located between the first tangent point and the focus point of the annular air outlet.

[0048] A lifting tin furnace 8 is arranged below the wire pressing plate 14. The photovoltaic solder tape 12 is pressed by the wire pressing plate 14 into the tin liquid 7 in the lifting tin furnace 8. The average density of the floating die 6 is less than the average density of the tin liquid 7.

[0049] In this embodiment: Primary sizing means using the floating die 6 to limit the amount of tin on the surface of the photovoltaic solder tape 12, and the amount of tin controlled is slightly greater than the thickness requirement of the product coating. During the upward traction process, the center of the floating die 6 moves around the photovoltaic solder tape 12, and a uniform tin column is maintained between the outlet of the floating die 6 and the annular air outlet, so that the tin column will never cause a large eccentricity. The photovoltaic solder tape 12 is a copper wire, and the tin liquid is a tin-lead alloy liquid.

[0050] Secondary sizing means using the annular air knife 5 to wipe the amount of tin on the surface of the photovoltaic solder tape 12. After the amount of tin attached to the surface of the photovoltaic solder tape 12 is limited, the air flow at the air outlet of the annular air knife 5 is easier to wipe, the required pressure becomes smaller, and the size fluctuation of the product coating formed by wiping with the annular air knife 5 is smaller, which is beneficial to the control of the finished product size and ensures the consistency of the product size;

[0051] After the tin column between the upper outlet of the floating die 6 and the annular air outlet is wiped by the annular air knife 5, the excess tin liquid flows back to the tin furnace along the conical surface of the floating die 6 through the gaps between the upper die rib strips 6-14 and the gaps between the lower die rib strips 6-23 in turn, and will not accumulate on the floating die 6.

[0052] During normal production, the floating die 6 floats on the surface of the tin furnace liquid. The upper surface and the conical surface tin outlet of the floating die 6 are higher than the liquid level. The tin liquid is taken out upward by the photovoltaic solder tape 12 from the upper die hole 6-13 at the lower surface inlet of the floating die 6. The impurities such as tin ash floating on the tin furnace liquid surface 7 are separated and will not enter the tin outlet of the floating die 6.

[0053] In addition, the first tangent point of the wire pressing plate 14 in the vertical direction refers to Figure 1 Point C (the tangent point of the wire pressing guide wheel and the solder tape in the vertical direction) in, and point B refers to the focus point of the annular air outlet of the combined air knife. The air flow at the air outlet of the annular air knife 5 will not cause the splashing of a small amount of tin liquid, and is not likely to cause adverse factors such as mold blockage and scalding.

[0054] The floating die is made of stainless steel. The density of the conventional 6040 tin-lead alloy is about 8.5g / cm 3 , and the density of stainless steel is about 7.98g / cm3. By the two-force balance method: F浮 = G 物 , that is, ρ 液 gv 排 = ρ 物 v 物 g. Stainless steel material v 排 / v 物 = 7.93 / 8.5 = 0.935.

[0055] Further, the floating mold 6 includes an upper mold 6-1 and a lower mold 6-2, and the upper mold 6-1 is screwed to the lower mold 6-2; the upper mold 6-1 includes a first ring 6-11, a tapered die core 6-12 is arranged inside the first ring 6-11, an upper mold hole 6-13 is arranged at the center of each tapered die core 6-12, the tapered die core 6-12 is connected to the inner wall of the first ring 6-11 through a plurality of upper mold rib strips 6-14, and there is a hollow between every two of the upper mold rib strips 6-14; the lower mold 6-2 includes a second ring 6-21, a central ring 6-22 is arranged at the center of the second ring 6-21, the central ring 6-22 is connected to the inner wall of the second ring 6-21 through a plurality of lower mold rib strips 6-23, there is a hollow between every two of the lower mold rib strips 6-23, and the lower mold rib strips 6-23 correspond to the upper mold rib strips 6-14.

[0056] In this embodiment: The floating mold 6 is as Figures 7-9 shown, and is composed of an upper mold 6-1 and a lower mold 6-2. A primary positioning sunk platform and a secondary positioning sunk platform are arranged on the back of the floating mold 6, wherein the primary positioning sunk platform is used for the concentricity of the center holes of the upper and lower molds, and the secondary sunk platform is responsible for the filling of the tin liquid; the lower mold 6-1 is similar in structure to the upper mold 6-2, and the inner diameter of the center hole is 1 / 2 of the inner diameter of the center hole of the upper mold 6-1. After the two are combined, an open cavity is formed on the joint surface as Figure 5 shown. After the mold is immersed in the tin liquid, the tin liquid fills the inner hole cavity of the mold through the hollow area of the lower mold, submerging the upper mold rib strips 6-14. At this time, under the action of the buoyancy of the tin liquid, the mold floats stably above the tin liquid, and the lower mold rib strips 6-23 and the upper mold rib strips 6-14 correspond to each other one by one.

[0057] Further, as Figures 5-6 shown, let the angle between every two of the upper mold rib strips 6-14 be D, then 45° ≤ D ≤ 90°.

[0058] Further, let the inner diameter of the upper mold hole 6-13 of the tapered die core 6-12 be G, then 1 mm ≤ G ≤ 2 mm.

[0059] In this embodiment: The upper die 6-1 is in a hollow shape. The range of the opening angle of the hollow part (i.e., the angle D between every two rib strips 6-14 of the upper die) is: 45° ≤ D ≤ 90°; The upper surface is in a conical distribution, with the cone angle 60° ≤ E = F ≤ 90°, the central hole 1mm ≤ G ≤ 2mm, and it is smaller than the inner hole size of the upper annular air knife 5.

[0060] Further, the upper surface of the conical die core 6-12 is a conical surface, and the lower part of the conical die core 6-12 is a conical cavity.

[0061] Further, the inner diameter of the ring hole of the central ring 6-22 is smaller than the inner diameter of the die hole 6-13 of the upper die.

[0062] In this embodiment: When the trace copper powder and flux residue remaining on the surface of the photovoltaic solder strip 12 pass through the floating die 6, since the lower die hole (i.e., the ring hole of the central ring 6-22) is smaller than the die hole 6-13 of the upper die. During the vertical upward traction process, the floating die 6 is in a floating state and is easy to move. If the photovoltaic solder strip 12 contacts the floating die 6, it will only contact the lower die hole, and the contact time is extremely short. The lower die hole is immersed in the tin liquid, which does not affect the tin amount of the tin outlet hole of the upper die.

[0063] Further, let the cone angle of the conical surface be F, and let the cone angle of the conical cavity be E, then 60° ≤ E = F ≤ 90°.

[0064] Further, both the wire pressing plate adjusting seat 2 and the air knife adjusting seat 3 are XY platforms. The XY platform can move up and down, left and right.

[0065] Further, a lifting screw 9 is arranged below the lifting tin furnace 8, and the up and down lifting of the tin furnace 8 is realized through the lifting screw 9.

[0066] The present invention also provides a system based on the device for tin plating of photovoltaic solder strips described in any one of the above, including a flux support cabinet 14. A flux storage area 13 is arranged inside the flux support cabinet 14, and the flux storage area 13 is inclined;

[0067] A traction guide wheel 10 is arranged on the frame 1. The traction guide wheel 10 is located above the annular air knife 5. The second tangent point and the first tangent point of the traction guide wheel 10 in the vertical direction, the center of the floating die 6, and the focus point of the annular air outlet of the annular air knife 5 are located on the same vertical line;

[0068] Two rows of cooling fans 11 are arranged between the traction guide wheel 10 and the annular air knife 5, and the photovoltaic solder strip 12 passes between the two rows of cooling fans 11;

[0069] The photovoltaic solder ribbon 12 sequentially passes through the flux storage area 13, the pressure plate 14, the floating die 6, the annular air knife 5, the cooling fan 11, and the guiding pulley 10.

[0070] In addition, the present invention also provides a process method based on a tin plating system, which specifically includes the following steps:

[0071] Step 1: Pass the photovoltaic solder ribbon 12 through the flux storage area 13 so that the outer surface of the photovoltaic solder ribbon 12 adheres to the flux.

[0072] Step 2: Press the photovoltaic solder ribbon 12 with flux on its outer surface into the molten tin 7 in the lifting tin furnace 8 through the pressure plate 14.

[0073] Step 3: Perform primary sizing through the floating die 6 and then perform secondary sizing through the annular air knife 5.

[0074] Step 4: The photovoltaic solder ribbon 12 is cooled by the cooling fan 11 and then moves along with the guiding pulley 10.

[0075] After the photovoltaic solder ribbon 12 is pressed into the tin furnace by the pressure plate 14, it is vertically pulled upward. The thickness of the surface tin layer is controlled by two methods: mechanical current limiting through the floating die 6 and wiping by the annular air knife. After air cooling, it is pulled backward for conveying. Among them:

[0076] Point A: The tangent point of the driving pulley and the solder ribbon in the vertical direction;

[0077] Point B: The focusing point of the annular air outlet of the combined air knife;

[0078] Point C: The tangent point of the pressure guiding pulley and the solder ribbon in the vertical direction.

[0079] Points A, B, and C are on the same straight line. Points A and C are fixed positions, and point B is ensured to be on the line AC through the air knife adjustment seat.

[0080] A tin plating process route for the photovoltaic solder ribbon involved in this patent (as Figure 1 shown): Along the advancing direction of the photovoltaic solder ribbon 12, the flux storage area 13, the pressure plate 14, the annular air knife 5, and the guiding pulley 10 are all in fixed positions. During installation, first ensure that points A and C are on the same vertical straight line, and then adjust the air knife adjustment seat 3 to ensure that the center of the annular air knife 5 is on the line AC. At this time, A, B, and C are on the same vertical straight line. The tin furnace 8 is fixed on the lifting platform and can move up and down through the lifting screw 9. The wire threading position is at the lowest position, and the working position is at the highest position (the pressure plate completely enters the molten tin).

[0081] During the tin plating operation, the pre-coated solder flux photovoltaic ribbon 12 bypasses the pressure plate 14 and is vertically lifted upward through the molten tin liquid 7. A large amount of tin alloy liquid adheres to the circumferential surface of the photovoltaic ribbon 12, presenting a conical shape. The central die hole of the floating die 6 controls the amount of tin plated to prevent a large amount of tin liquid from being pulled upward, and wipes the originally conical tin liquid into an approximately cylindrical tin liquid at the outlet of the floating die 6. The tin liquid breaking through the central die hole continues to move upward with the photovoltaic ribbon 12. When passing through the annular air nozzle in the annular air knife 5, the blown air stream wipes the tin liquid on the surface of the copper wire. The excess and small amount of tin liquid flows back to the tin furnace under the action of the air stream and gravity (flows back to the tin furnace along the conical surface of the floating die), and the liquid remaining on the surface of the photovoltaic ribbon 12 forms a uniform tin alloy coating after cooling. During the tin plating process, the tin liquid continuously consumes and becomes less, and the distance between the annular air knife and the floating die continuously increases. To ensure the stability of product quality, the lifting worm motor can be automatically controlled according to the consumption of the tin alloy to increase the H distance, ensuring that the distance between the floating die 6 and the annular air knife 5 remains basically unchanged. When H reaches the upper limit, it reminds the staff to add the alloy, and at the same time, the tin furnace is lowered to a suitable position.

[0082] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0083] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. An apparatus for tin plating of photovoltaic solder tapes, comprising a frame (1), characterized in that, A wire pressing plate adjusting seat (2) and an air knife adjusting seat (3) are arranged on the frame (1). The wire pressing plate adjusting seat (2) is connected with a fixing plate (4), and a wire pressing plate (14) is arranged at the lower end of the fixing plate (4). It further includes a floating die (6) for primary sizing and an annular air knife (5) for secondary sizing. The first tangent point (C) of the wire pressing plate (14) in the vertical direction and the focusing point (B) of the annular air outlet of the annular air knife (5) are on the same vertical line. The floating die (6) is located between the first tangent point (C) and the focusing point (B) of the annular air outlet. A lifting tin furnace (8) is arranged below the wire pressing plate (14), and a lifting screw rod (9) is arranged below the lifting tin furnace (8). The photovoltaic solder tape (12) is pressed into the tin liquid (7) in the lifting tin furnace (8) by the wire pressing plate (14). The average density of the floating die (6) is less than the average density of the tin liquid (7).

2. The tin plating device for a photovoltaic solder strip according to claim 1, wherein, The floating die (6) includes an upper die (6-1) and a lower die (6-2), and the upper die (6-1) is screwed to the lower die (6-2). The upper die (6-1) includes a first ring (6-11), a tapered die core (6-12) is arranged inside the first ring (6-11), an upper die hole (6-13) is arranged at the center of each tapered die core (6-12), and the tapered die core (6-12) is connected to the inner wall of the first ring (6-11) through a plurality of upper die rib strips (6-14). There is a hollow space between every two of the upper die rib strips (6-14). The lower die (6-2) includes a second ring (6-21), a central ring (6-22) is arranged at the center of the second ring (6-21), and the central ring (6-22) is connected to the inner wall of the second ring (6-21) through a plurality of lower die rib strips (6-23). There is a hollow space between every two of the lower die rib strips (6-23), and the lower die rib strips (6-23) correspond to the upper die rib strips (6-14).

3. The tin plating device for a photovoltaic solder ribbon according to claim 2, characterized in that, Let the angle between every two of the upper die rib strips (6-14) be D, then 45°≤D≤90°.

4. The tin plating device for a photovoltaic solder strip according to claim 2, wherein, Let the inner diameter of the upper die hole (6-13) be G, then 1mm≤G≤2mm.

5. The tin plating device for a photovoltaic solder ribbon according to claim 2, wherein, The inner diameter of the ring hole of the central ring (6-22) is smaller than the inner diameter of the upper die hole (6-13).

6. The tin plating device for a photovoltaic solder strip according to claim 2, wherein, The upper surface of the tapered die core (6-12) is a tapered surface, and the inside of the tapered die core (6-12) is a tapered cavity.

7. A tin-plating device for photovoltaic solder strips according to claim 6, characterized in that, Let the cone angle of the tapered surface be F, and let the cone angle of the tapered cavity be E, then 60°≤E = F≤90°.

8. A tin plating device for photovoltaic solder tapes according to claim 1, characterized in that, Both the wire pressing plate adjusting seat (2) and the air knife adjusting seat (3) are XY platforms.

9. The tin plating system of a tin plating device for photovoltaic solder ribbons according to any one of claims 1 to 8, characterized in that, It includes a flux support cabinet (14), and a flux storage area (13) is arranged inside the flux support cabinet (14). The flux storage area (13) is arranged in an inclined manner. A traction guide pulley (10) is provided on the frame (1). The traction guide pulley (10) is located above the annular air knife (5). The second tangent point (A) and the first tangent point (C) of the traction guide pulley (10) in the vertical direction and the annular air outlet focus point (B) of the annular air knife (5) are on the same vertical line. Two rows of cooling fans (11) are provided between the traction guide pulley (10) and the annular air knife (5). The photovoltaic solder tape (12) passes between the two rows of cooling fans (11). The photovoltaic solder tape (12) successively passes through the flux storage area (13), the pressure plate (14), the floating die (6), the annular air knife (5), the cooling fan (11), and the traction guide pulley (10).

10. A process method for photovoltaic tin plating, characterized in that, Applied to the tin plating system described in claim 9, it specifically includes the following steps: Step 1: Pass the photovoltaic solder tape (12) through the flux storage area (13) so that the outer surface of the photovoltaic solder tape (12) adheres to the flux. Step 2: Press the photovoltaic solder tape (12) with the flux adhering to its outer surface into the molten tin (7) in the lifting tin furnace (8) through the pressure plate (14). Step 3: Perform primary sizing through the floating die (6) and then perform secondary sizing through the annular air knife (5). Step 4: The photovoltaic solder tape (12) is cooled by the cooling fan (11) and then moves along with the traction guide pulley (10).

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