Pressure tin plating device and method for photovoltaic welding strip

Abstract

The invention belongs to the technical field of solder strip manufacturing, and relates to a pressure tinning device and method for a photovoltaic solder strip. The device comprises a rack, a driving traction mechanism is arranged on the rack, a pressure coating mechanism, a high-frequency heating mechanism and a shaping mechanism are sequentially arranged below the driving traction mechanism, and a water cooling mechanism and a blow-drying mechanism are sequentially and transversely arranged below the shaping mechanism; a diameter measuring instrument and a winding mechanism are arranged on the rack; a copper base material sequentially passes through the pressure coating mechanism, the high-frequency heating mechanism and the shaping mechanism to achieve coating and shaping of a tin-lead coating, and the copper base material coated with the tin-lead coating achieves cooling of the tin-lead coating through the water cooling mechanism. A traditional hot dipping process is abandoned, firstly, the surface of a copper base material is coated with tin-lead paste with a certain thickness, the paste is heated on line at low temperature to be melted and then attached to the surface of a copper wire, and finally, the paste is water-cooled to the room temperature step by step to complete preparation of a welding strip product.

Description

Technical Field

[0001] The present invention belongs to the technical field of solder ribbon manufacturing, and relates to a pressure tin plating device and method for photovoltaic solder ribbons. Background Art

[0002] Currently, the grid lines used on most photovoltaic cells are strip-shaped bodies made of silver and attached to the cell surface. They are divided into main grids and fine grids. The fine grids are thinner and the main grids are thicker. After the current is generated, it takes the fine grids as the path, converges to the main grid, and then is transmitted by the main grid to the copper solder ribbon and then exported. With the continuous iteration and update of battery technology and packaging technology, the number of main grids is increasing year by year, 3BB, 4BB, 5BB... As the number of main grids increases, by 2024, the photovoltaic modules produced in the industry with the most main grids have reached 20BB+. As the solder ribbon used as a conductive material, its product specifications are also constantly decreasing, and the demand for circular solder ribbons with a diameter of less than 0.2 mm is increasing day by day.

[0003] As the wire diameter of the solder ribbon continues to decrease, the difficulty of material manufacturing also increases. The traditional vertical hot dip plating process has high energy consumption, large wire transfer resistance, unstable surface tension, and is extremely likely to cause stretching deformation of thin wires; when producing thin solder ribbons, problems such as large tension fluctuations, severe wire shaking, and inconsistent wire diameters of the product line will occur, seriously affecting the quality of the solder ribbon. Therefore, how to reduce the product manufacturing cost and reduce the surface tension of the wire is an urgent problem to be solved by solder ribbon production enterprises. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and propose a pressure tin plating device and method for photovoltaic solder ribbons.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A pressure tin plating device for photovoltaic solder ribbons includes a frame. A driving and traction mechanism is arranged on the frame. A coating and shaping mechanism is arranged below the driving and traction mechanism. The coating and shaping mechanism includes a pressure coating mechanism, a high-frequency heating mechanism, and a shaping mechanism arranged in sequence from top to bottom. A water cooling mechanism and a drying mechanism are arranged horizontally in sequence below the shaping mechanism; a diameter measuring instrument and a winding mechanism are arranged on the frame;

[0007] The copper substrate is coated and shaped with a tin-lead coating through the coating and shaping mechanism, and the copper substrate coated with the tin-lead coating is cooled through the water cooling mechanism.

[0008] Further, the pressure coating mechanism includes a pressure storage tank and a pressure coating die. A pressure mechanism is connected to the upper end of the pressure storage tank, and a first circulation pipeline is connected to the lower end of the pressure storage tank. The first circulation pipeline communicates with the middle cavity of the pressure coating die. The tin-lead paste in the pressure storage tank is pressed into the middle cavity by the pressure mechanism. An upper die is arranged above the middle cavity, and a lower die is arranged below the middle cavity. An upper die hole is arranged in the middle of the upper die, and a lower die hole is arranged in the middle of the lower die. The upper wall of the middle cavity is communicated with the upper die hole, and the lower wall of the middle cavity is communicated with the lower die hole. The upper die hole is funnel-shaped and communicates with the die inner cavity. The die inner cavity communicates with a paste recovery tank through a second circulation pipeline.

[0009] Further, the pressure mechanism includes a gas source. The gas source is communicated with the upper end of the pressure storage tank through a gas channel, and a pressure gauge and an electro-pneumatic proportional valve are connected to the gas channel.

[0010] Further, a circulation valve is arranged on the first circulation pipeline.

[0011] Further, the high-frequency heating mechanism includes a heating tube, an induction coil is wound around the outer surface of the heating tube, and the copper substrate passes through the lumen of the heating tube.

[0012] Further, a negative pressure tail gas collection system is arranged above the high-frequency heating mechanism.

[0013] Further, the shaping mechanism is an annular air knife or a sizing die.

[0014] Further, the water cooling mechanism includes a primary water cooling tank and a secondary water cooling tank. The water temperature in the primary water cooling tank is 70°C - 80°C, and the water temperature in the secondary water cooling tank is 25°C - 30°C.

[0015] Further, the diameter measuring instrument feeds back the measured diameter value to the control system, and the control system adjusts the opening degree of the electro-pneumatic proportional valve through the controller.

[0016] The present invention also provides a method for a pressure tin plating device for a photovoltaic solder strip, which specifically includes the following steps:

[0017] Step 1: The copper substrate moves under the drive of the driving and traction mechanism and the winding mechanism, and moves to the pressure coating mechanism so that the surface of the copper substrate is coated with a tin-lead coating, and the tin-lead coating contains a soldering flux;

[0018] Step 2: The copper substrate coated with a tin-lead coating is moved to a high-frequency heating mechanism to melt the tin-lead coating on the surface of the copper substrate and volatilize the flux in a gaseous form. Then, the shaped mechanism is used to shape the melted tin-lead coating to ensure uniform distribution of the tin-lead coating on the surface of the copper substrate.

[0019] Step 3: The copper substrate coated with a tin-lead coating is sequentially subjected to primary water cooling and secondary water cooling through a water cooling mechanism, and then the water stains on the surface of the copper substrate are dried by a drying mechanism.

[0020] Step 4: The diameter of the copper substrate is measured by a diameter gauge and fed back to the control system.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] First, the present invention abandons the traditional hot-dip plating process. First, a tin-lead paste with a certain thickness is coated on the surface of the copper substrate, and the paste is heated at a low temperature online to melt and then adhere to the surface of the copper wire. Finally, it is gradually water-cooled to room temperature to complete the preparation of the solder strip product.

[0023] Second, in the present invention, during the forward conveying process of the wire, it is all rolling friction, and the traction tension is small.

[0024] Third, after the tin-lead paste is heated by high-frequency induction, its organic matter directly volatilizes, and the remaining metal part solidifies on the copper base surface. After being slightly leveled by an air brush, it is directly gradient water-cooled to room temperature. The water-cooling mode is direct heat exchange, which can effectively reduce the cooling length of the wire, shorten the wire tension transmission distance, and increase the sensitivity of the equipment system. It is beneficial for the production equipment to operate smoothly at a high speed and ensure the product consistency.

[0025] Fourth, the coating condition uses a tin-lead paste stored at room temperature, pressure coating, online real-time monitoring of the wire diameter and thickness, controlling the supply of the paste through air pressure, which is safe, reliable and low in energy consumption, and is beneficial for the overall cost control. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings here are incorporated into the specification and form a part of this specification, and are used together with the specification to explain the principles of the present invention.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a schematic diagram of the pressure coating tin plating process in the present invention;

[0029] Figure 2 Schematic diagram of the pressure coating die in the present invention;

[0030] Figure 3 Schematic diagram of the high-frequency heating mechanism in the present invention;

[0031] Figure 4 Schematic diagram of the principle for controlling the coating thickness in the present invention.

[0032] Among them: 1 is the driving and traction mechanism; 2 is the pressure coating mechanism; 2-1 is the pressure storage tank; 2-2 is the pressure mechanism; 2-21 is the gas source; 2-22 is the pressure gauge; 2-23 is the electro-pneumatic proportional valve; 2-3 is the flow valve; 2-4 is the upper die; 2-5 is the intermediate cavity; 2-6 is the lower die; 2-7 is the slurry recovery tank; 3 is the high-frequency heating mechanism; 4 is the shaping mechanism; 5 is the water cooling mechanism; 5-1 is the primary water cooling tank; 5-2 is the secondary water cooling tank; 6 is the air drying mechanism; 7 is the diameter gauge; 8 is the winding mechanism; 10 is the copper substrate. Specific embodiments

[0033] 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 merely examples consistent with some aspects of the present invention detailed in the appended claims.

[0034] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] Embodiment

[0036] As Figure 1 shown, a pressure tin plating device for photovoltaic solder tapes includes a frame. A driving and traction mechanism 1 is arranged on the frame. Below the driving and traction mechanism 1, a pressure coating mechanism 2, a high-frequency heating mechanism 3, and a shaping mechanism 4 are sequentially arranged. Below the shaping mechanism 4, a water cooling mechanism 5 and an air drying mechanism 6 are arranged horizontally in sequence; a diameter gauge 7 and a winding mechanism 8 are arranged on the frame;

[0037] The copper substrate 10 passes through the pressure coating mechanism 2, the high-frequency heating mechanism 3, and the shaping mechanism 4 in sequence to achieve the coating and shaping of the tin-lead coating. The copper substrate 10 coated with the tin-lead coating is cooled by the water cooling mechanism 5 to lower the temperature of the tin-lead coating.

[0038] In this embodiment: First, a certain thickness of tin-lead slurry is coated on the surface of the copper substrate 10, and the slurry is heated at low temperature online to melt and then adheres to the surface of the copper substrate 10. Finally, it is gradually cooled to room temperature to complete the preparation of the solder tape product.

[0039] In this process mode, the wire is in rolling friction during the forward conveying process, and the traction tension is small. At the same time, after the tin-lead paste is heated by high-frequency induction, its organic matter volatilizes directly, and the remaining metal part solidifies on the surface of the copper substrate 10. After being slightly leveled by the air brush, it is directly cooled to room temperature by gradient water cooling. The direct heat exchange in the water cooling mode effectively reduces the cooling length of the copper substrate 10, shortens the tension transmission distance of the copper substrate 10, and increases the sensitivity of the equipment system, which is beneficial to the stable operation of the production equipment at high speed and ensures the product consistency. The coating condition uses a tin-lead paste stored at room temperature, pressure coating, online real-time monitoring of the wire diameter and thickness, controlling the supply of the paste through air pressure, which is safe, reliable and has low energy consumption, and is beneficial to the overall cost control.

[0040] Further, as Figure 2 shown, the pressure coating mechanism 2 includes a pressure storage tank 2-1 and a pressure coating die. The upper end of the pressure storage tank 2-1 is connected to a pressure mechanism 2-2, the lower end of the pressure storage tank 2-1 is connected to a first circulation pipeline, and the first circulation pipeline communicates with the middle cavity 2-5 of the pressure coating die. The pressure storage tank 2-1 presses the tin-lead paste in the pressure storage tank 2-1 into the middle cavity 2-5 through the pressure mechanism 2-2. Above the middle cavity 2-5, there is an upper die 2-4, and below the middle cavity 2-6, there is a lower die 2-6. In the middle of the upper die 2-4, there is an upper die hole, and in the middle of the lower die 2-6, there is a lower die hole. The upper part of the middle cavity 2-5 communicates with the upper die hole, and the lower part of the middle cavity 2-5 communicates with the lower die hole. The upper die hole is funnel-shaped and communicates with the die inner cavity, and the die inner cavity communicates with a paste recovery tank 2-7 through a second circulation pipeline.

[0041] In this embodiment: The copper substrate 10 vertically enters the pressure coating mechanism 2 through the driving and traction mechanism 1. The tin-lead paste filled in the middle cavity 2-5 is extruded from the lower die 2-6 under the action of gas pressure and its own gravity, adheres to the surface of the copper substrate, and moves vertically downward with the traction of the copper substrate. At this time, the liquid paste spreads evenly on the surface of the substrate under the action of surface tension.

[0042] It should be noted that the tin-lead paste leaking from the lower die 2-6 will adhere to the surface of the copper substrate. When the electrical proportional valve 2-23 is adjusted to increase the gas pressure, the pressure in the middle cavity 2-5 increases, and the tin-lead paste flowing out of the die hole of the lower die will increase, thereby increasing the tin-lead paste adhering to the surface of the copper substrate and increasing the diameter of the solder strip; conversely, the diameter of the solder strip decreases.

[0043] When working, the tin-lead paste is in a closed environment. Under the action of gas pressure, the paste is introduced into the intermediate cavity 2-5 through the first circulation pipeline. The upper die hole of the intermediate cavity 2-5 is 1.5-2 times the diameter of the lower die hole. The paste extruded from the upper die 2-4 fills the die cavity above it and then overflows back to the paste recovery tank 2-7. The paste extruded from the lower die 2-6 runs downward along with the copper substrate 10 and spreads in the circumferential direction of the copper substrate 10. For the current products with wire diameters below 0.3mm, generally, the lower die hole is increased by 30μm on the basis of the wire diameter.

[0044] Moreover, the tin-lead paste is made by mixing a soldering flux with tin-lead powder below 325 mesh, which is stable and durable and can be used at room temperature.

[0045] Furthermore, the pressure mechanism 2-2 includes a gas source 2-21. The gas source 2-21 is connected to the upper end of the pressure storage tank 2-1 through a gas channel, and a pressure gauge 2-22 and an electro-pneumatic proportional valve 2-23 are connected to the gas source 2-21 channel.

[0046] In this embodiment: The pressure gauge 2-22 can reflect the gas pressure in real time, and the intake pressure can be adjusted by adjusting the electro-pneumatic proportional valve 2-23.

[0047] Furthermore, a circulation valve 2-3 is arranged on the first circulation pipeline.

[0048] In this embodiment: The circulation valve 2-3 can control the opening or closing of the first circulation pipeline.

[0049] Furthermore, the high-frequency heating mechanism 3 includes a heating tube 3-2. An induction coil 3-1 is wound around the outer surface of the heating tube 3-2, and the copper substrate 10 passes through the tube cavity 3-3 of the heating tube 3-2.

[0050] In this embodiment: When the copper substrate 10 with paste attached passes through the tube cavity 3-3, it is heated to a temperature above 200°C in a very short time. The paste is heated and melted, and organic substances such as the soldering flux are volatilized and released in the form of gas. The tail gas is discharged after being photocatalytically oxidized by the upper-end negative-pressure collection system, and the remaining melted tin-lead powder spreads on the copper substrate 10.

[0051] Furthermore, as Figure 3 shown, a negative-pressure tail gas collection system 9 is arranged above the high-frequency heating mechanism 3.

[0052] In this embodiment: The negative-pressure tail gas collection system 9 is a prior art and can absorb the tail gas.

[0053] Furthermore, the shaping mechanism 4 is an annular air knife or a sizing die.

[0054] In this embodiment: at the end of the high-frequency heating mechanism 3, an annular splitting knife or a sizing die is provided to perform micro-shaping on the liquid coating to ensure uniform distribution of the coating on the circumferential surface.

[0055] Further, the water cooling mechanism 5 includes a primary water cooling tank 5-1 and a secondary water cooling tank 5-2. The water temperature in the primary water cooling tank 5-1 is 70°C to 80°C, and the water temperature in the secondary water cooling tank 5-2 is 25°C to 30°C.

[0056] In this embodiment: the heated wire is continuously pulled downward and exchanges heat with the air. When the surface temperature drops to about 150°C, the surface tin-lead layer begins to condense. At this time, the copper wire passes through the primary water cooling tank (water temperature 70°C - 80°C) and the secondary water cooling tank (water temperature 25°C - 30°C) in sequence for direct heat exchange and gradient cooling. The air drying mechanism at the end of the secondary water cooling blows and brushes the water stains on the surface of the wire clean.

[0057] It should be noted that a guide wheel is provided in the primary water cooling tank 5-1 and fixed on the side wall of the primary water cooling tank. The copper substrate can change its moving direction through the guide wheel, so that the copper substrate changes from vertical movement to horizontal movement.

[0058] The diameter measuring instrument 7 feeds back the measured diameter value to the control system, and the control system adjusts the opening degree of the electro-hydraulic proportional valve 2-23 through the controller.

[0059] In this embodiment: as Figure 4 shown, the diameter measuring instrument measures the wire diameter online, feeds back the wire diameter value to the control system, compares the wire diameter value with the initial set value. When the difference between the two is within the tolerance range, continuous production is maintained with the existing gas pressure; when the wire diameter fluctuation tolerance exceeds the set value, if it exceeds the upper tolerance limit, the electro-hydraulic proportional valve is adjusted through the controller to reduce the air pressure and thin the coating, and vice versa, the air pressure is increased to increase the coating.

[0060] The present invention also provides a method for a pressure tin plating device for a photovoltaic solder ribbon, which specifically includes the following steps:

[0061] Step 1: The copper substrate 10 moves under the drive of the driving and traction mechanism 1 and the winding mechanism 8, and moves to the pressure coating mechanism 2 so that the surface of the copper substrate 10 is coated with a tin-lead coating, and the tin-lead coating contains a soldering flux.

[0062] Step 2: The copper substrate 10 coated with the tin-lead coating moves to the high-frequency heating mechanism 3 so that the tin-lead coating on the surface of the copper substrate 10 melts and the soldering flux in the tin-lead coating volatilizes in a gaseous form, and then the shaped tin-lead coating is shaped by the shaping mechanism 4 to ensure uniform distribution of the tin-lead coating on the surface of the copper substrate 10.

[0063] Step 3: The copper substrate 10 coated with a tin-lead coating is subjected to primary water cooling and secondary water cooling in sequence by the water cooling mechanism 5, and then the water stains on the surface of the copper substrate 10 are blown dry by the air drying mechanism 6.

[0064] Step 4: The diameter of the copper substrate 10 is measured by the diameter gauge 7 and fed back to the control system

[0065] 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, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0066] 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. A pressure tinning device for photovoltaic welding strips, comprising a frame, characterized in that: The frame is provided with a driving and traction mechanism (1), a coating and shaping mechanism is provided below the driving and traction mechanism (1), the coating and shaping mechanism comprises a pressure coating mechanism (2), a high-frequency heating mechanism (3) and a shaping mechanism (4) which are arranged in sequence from top to bottom, and a water cooling mechanism (5) and a drying mechanism (6) are arranged in sequence below the shaping mechanism (4); the frame is provided with a diameter measuring instrument (7) and a winding mechanism (8); The copper substrate (10) is coated with and shaped with a tin-lead coating by means of a coating and shaping mechanism, and the copper substrate (10) coated with the tin-lead coating is cooled by means of a water cooling mechanism (5).

2. A pressure tinning device for photovoltaic ribbon according to claim 1, characterized in that: The pressure coating mechanism (2) comprises a pressure storage box (2-1) and a pressure coating mold. The upper end of the pressure storage box (2-1) is connected to a pressure mechanism (2-2). The lower end of the pressure storage box (2-1) is connected to a first flow pipe. The first flow pipe is connected to an intermediate cavity (2-5) of the pressure coating mold. The tin-lead paste in the pressure storage box (2-1) is pressed into the intermediate cavity (2-5) by the pressure mechanism (2-2). The upper part of the intermediate cavity (2-5) is provided with a pressure mechanism (2-2). An upper mold (2-4) is provided, a lower mold (2-6) is provided below the intermediate cavity (2-5), an upper mold hole is provided in the middle of the upper mold (2-4), a lower mold hole is provided in the middle of the lower mold (2-6), the upper wall of the intermediate cavity (2-5) is connected to the upper mold hole, the lower wall of the intermediate cavity (2-5) is connected to the lower mold hole, the upper mold hole is funnel-shaped, the upper mold hole is connected to the mold cavity, and the mold cavity is connected to the slurry recovery box (2-7) through a second flow pipe.

3. A pressure tinning device for photovoltaic welding strip according to claim 2, characterized in that: The pressure mechanism (2-2) comprises a gas source (2-21), the gas source (2-21) is connected to the upper end of the pressure storage box (2-1) through a gas channel, and the gas channel is connected to a pressure gauge (2-22) and an electric proportional valve (2-23).

4. A pressure tinning device for photovoltaic welding strip according to claim 2, characterized in that: The first circulation pipeline is provided with a circulation valve (2-3).

5. A pressure tinning device for photovoltaic ribbon according to claim 1, characterized in that: The high-frequency heating mechanism (3) comprises a heating tube (3-2), the outer surface of which is wound with an induction coil (3-1), and the copper substrate (10) passes through the tube cavity (3-3) of the heating tube (3-2).

6. A pressure tinning device for photovoltaic welding strip according to claim 1, characterized in that: A negative pressure tail gas collection system (9) is arranged above the high-frequency heating mechanism (3).

7. A pressure tinning device for photovoltaic ribbon according to claim 1, characterized in that: The shaping mechanism (4) is an annular air knife or a sizing die.

8. A pressure tinning device for photovoltaic ribbon according to claim 1, characterized in that: The water cooling mechanism (5) comprises a primary water cooling box (5-1) and a secondary water cooling box (5-2), the water temperature in the primary water cooling box (5-1) is 70°C to 80°C, and the water temperature in the secondary water cooling box (5-2) is 25°C to 30°C.

9. A pressure tinning device for photovoltaic ribbons according to claim 1, characterized in that: The diameter measuring instrument (7) feeds back the measured diameter value to the control system, and the control system adjusts the opening size of the electric proportional valve (2-23) through the controller.

10. A method for a pressure tinning device for photovoltaic ribbons according to any one of claims 1 to 9, characterized in that: The specific steps include: Step 1: The copper substrate (10) is moved under the drive of the driving traction mechanism (1) and the winding mechanism (8) to the pressure coating mechanism (2) so that the surface of the copper substrate (10) is coated with a tin-lead coating, wherein the tin-lead coating contains a soldering flux; Step 2: The copper substrate (10) coated with the tin-lead coating is moved to a high-frequency heating mechanism (3) to melt the tin-lead coating on the surface of the copper substrate (10) and volatilize the soldering flux in the form of gas, and then the melted tin-lead coating is shaped by a shaping mechanism (4) to ensure that the tin-lead coating is evenly distributed on the surface of the copper substrate (10); Step 3: performing primary water cooling and secondary water cooling on the copper substrate (10) coated with the tin-lead coating by means of a water cooling mechanism (5), and then drying water stains on the surface of the copper substrate (10) by means of a drying mechanism (6); Step 4: Measure the diameter of the copper substrate (10) using a diameter gauge (7) and feed back to the control system.

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