Reverse tinning device and reverse tinning method for solder strip

Abstract

The present invention discloses a reverse tinning device and method for soldering strips. The device includes a special-shaped tin pot, a flux cylinder, and a cooling assembly. The special-shaped tin pot has a concave longitudinal section and includes a right cavity and a left cavity. The bottom of the right cavity is connected to the bottom of the left cavity. The right cavity has an air inlet and an outlet. The upper surface of the right cavity has a wire inlet. The lower surface of the right cavity has a wire outlet on the same vertical line as the wire inlet. The wire outlet is fixedly connected to a mold. A flux cylinder is located directly above the wire inlet. The upper surface of the left cavity has a left air inlet and a pressure relief port. The right surface of the left cavity has a tin addition port and a tin discharge port. The cooling assembly is vertically arranged directly below the mold. The device uses the special-shaped tin pot to adjust the pressure of the compressed air, and the cooling assembly to quickly cool down the temperature. Compared with the existing technology, the produced soldering strip has better stability and more stable tension transmission. It is more conducive to high-speed production of soldering strips and can also achieve adjustment of the soldering strip coating thickness.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic solder strip tinning equipment, and in particular to a reverse tinning device and a reverse tinning method for a solder strip. Background Art

[0002] Currently, in the photovoltaic industry, there are two primary production methods for photovoltaic ribbons: electroplating and hot-dip plating. Electroplating is relatively expensive and holds a relatively small market share in the photovoltaic industry, while hot-dip plating, the mainstream method, is cheaper and holds a significant advantage. However, both domestically and internationally, hot-dip production suffers from slow production speeds, low efficiency, and poor surface quality (primarily concentricity). As a crucial raw material in the production of photovoltaic module encapsulation, the quality and cost of photovoltaic ribbons play a crucial role. Market demand for photovoltaic ribbons is expected to increase two- to three-fold in the next few years. Therefore, rapid technological advancements in ribbon production efficiency and quality are crucial.

[0003] Therefore, how to produce high-efficiency, high-quality welding strips is a technical problem that those skilled in the art currently need to solve. Summary of the Invention

[0004] In order to solve the above technical problems, the main purpose of the present invention is to disclose a reverse tinning device and reverse tinning method for soldering strips. Through the special-shaped tin furnace, flux cylinder and cooling assembly, the three work together to have a certain liquid pressure. Combined with the pressure of the gas, the copper wire has a certain centripetal pressure in the circumferential direction, so the copper wire can be better in the center position of the mold, and thus the concentricity of the soldering strip will be better. Moreover, when using this method to produce soldering strips, the running direction of the copper wire is from top to bottom, and the gravity direction of the tin alloy is also from top to bottom. The yield strength of the soldering strip can be lower and the stability can be better. The tension transmission is more stable, which is more conducive to the high-speed production of soldering strips. It can be used to improve production speed, improve efficiency, and enhance the surface quality of soldering strips.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions to solve it.

[0006] (1) A reverse tinning device for a soldering strip, used for tinning a copper wire, the reverse tinning device comprising a special-shaped tin pot, a flux cylinder and a cooling assembly, the special-shaped tin pot having a longitudinal section in the shape of a "concave" character, the special-shaped tin pot comprising a right cavity and a left cavity, the bottom of the right cavity being connected to the bottom of the left cavity, an air inlet and an outlet being provided on the upper portion of the right cavity, a wire inlet being provided on the upper surface of the right cavity, a wire outlet being provided on the same vertical line as the wire inlet on the lower surface of the right cavity, a sizing die being fixedly connected to the wire outlet, and a wire passing hole being provided in the middle of the sizing die.

[0007] Furthermore, a flux cylinder is provided just above the wire inlet, a wire hole is provided at the lower end of the flux cylinder and is on the same vertical line as the wire inlet, and paste flux is provided in the flux cylinder.

[0008] Furthermore, a left air inlet is provided on the upper surface of the left cavity, a pressure relief port is provided on the upper surface of the left cavity, a tin adding port is provided on the upper end of the left surface of the left cavity, a tin discharge port is provided on the lower end of the left surface of the left cavity, and the cooling assembly is vertically arranged directly below the sizing mold.

[0009] Furthermore, the reverse tinning device further comprises a draw rod, the diameter of which is smaller than the diameter of the wire hole of the sizing die, the length of which is greater than the distance from the wire outlet to the wire inlet, and the draw rod is a hard copper wire.

[0010] Furthermore, a tin plating liquid is provided in the special-shaped tin furnace.

[0011] Furthermore, the cooling assembly includes a chiller and a water-cooling cavity, and the water-cooling cavity is composed of hollow semi-cylindrical chambers symmetrically arranged on the left and right sides. The hollow semi-cylindrical chambers on the left and right sides are enclosed to form a cooling air duct inside, and the cooling air duct is used to pass the welding strip vertically.

[0012] Furthermore, the chiller has a water outlet and a water inlet, the water outlet of the chiller is connected to a hose, one end of the hose is divided into two branches, each branch longitudinally passes through one side of the hollow semi-cylindrical chamber and is connected to the water inlet of the chiller.

[0013] Furthermore, the length of the cooling air duct is 3-5 meters.

[0014] Furthermore, the tin plating solution is a tin-bismuth-silver alloy or a tin-lead alloy.

[0015] Furthermore, the diameter of the wire inlet is 20-30 μm larger than the diameter of the copper wire.

[0016] (2) A method for reverse tinning of a solder strip, comprising the following steps:

[0017] Step 1: Adjust the upper positioning wheel above the flux barrel and the lower positioning wheel below the cooling assembly so that the vertical tangent direction of the upper positioning wheel, the vertical tangent direction of the lower positioning wheel and the center of the sizing die are on the same vertical line;

[0018] Step 2: Pass the traction rod from the inlet to the outlet, and keep it in both the inlet and outlet at the same time; add tin plating liquid into the special-shaped tin furnace and heat it to a molten state;

[0019] Step 3: Open the pressure relief port of the left cavity and pressurize the right cavity of the special-shaped tin furnace from the air inlet and outlet, so that the tin plating liquid in the right cavity flows into the left cavity under pressure;

[0020] Step 4: The tinned copper wire is released from the pay-off device, thinned by the wire drawing device, and then annealed by the annealing device to become a soft copper wire. The soft copper wire is passed around the upper positioning wheel and then passed through the flux cylinder. It is connected to the upper end of the traction rod and, under the traction of the traction rod, passes through the wire inlet and outlet of the special-shaped tin furnace in sequence, passes through the cooling air duct, and is wound out from the lower positioning wheel to the wire take-up device.

[0021] Step 5, adjusting the thickness of the coating on the surface of the copper wire by adjusting the pressure in the left cavity and the right cavity;

[0022] Step 6: Start the pay-off equipment and the take-up equipment. The tinned copper wire becomes a tinned solder strip and is taken up onto a reel.

[0023] Furthermore, in step 4, the temperature of the tinned solder strip coming out of the cooling air duct of the cooling assembly is 50-60°C.

[0024] Furthermore, in step 5, the method for adjusting the thickness of the coating on the surface of the welding strip is: when the coating on the surface of the welding strip is thin, the pressure in the left cavity is increased or the pressure in the right cavity is decreased; when the coating on the surface of the welding strip is thick, the pressure in the left cavity is decreased or the pressure in the right cavity is increased.

[0025] Compared with the existing technology, the present invention subverts the existing production process and can evenly cover the circumference of the copper wire with a tin-lead alloy with a thickness of 10μm to 25μm. The entire production line can maintain a high-speed operation of 500m / min to 800m / min, and can produce high-efficiency, high-quality solder strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 It is a schematic diagram of the working of the whole device;

[0029] Figure 3 This is a schematic diagram of the longitudinal section of a special-shaped tin furnace;

[0030] Figure 4 Schematic diagram of cooling air duct;

[0031] In the above diagram:

[0032] 1-Special-shaped tin pot; 2-Flux cylinder; 3-Cooling assembly; 301-Chiller; 302-Hollow semi-cylindrical chamber; 303-Cooling air duct; 304-Hose; 4-Right cavity; 5-Left cavity; 6-Air inlet and outlet; 7-Wire inlet; 8-Sizing die; 9-Left air inlet; 10-Pressure relief port; 11-Tin inlet; 12-Tin outlet. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] The following description sets forth specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art will be able to make similar generalizations without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] (1) Please refer to Figure 1 , Figure 1 It is a reverse tinning device for a soldering strip, used for tinning a copper wire. The reverse tinning device includes a special-shaped tin pot 1, a flux cylinder 2 and a cooling assembly 3. The longitudinal section of the special-shaped tin pot 1 is a "concave" shape. The special-shaped tin pot 1 includes a right cavity 4 and a left cavity 5. The bottom of the right cavity 4 is connected to the bottom of the left cavity 5. The upper part of the right cavity 4 is provided with an air inlet and outlet 6. The upper surface of the right cavity 4 is provided with a wire inlet 7. The lower surface of the right cavity 4 is provided with a wire outlet on the same vertical line as the wire inlet 7. The wire outlet is fixedly connected to a sizing die 8, and a wire hole is provided in the middle of the sizing die 8.

[0036] Furthermore, a flux cylinder 2 is provided directly above the wire inlet 7, and a wire hole is provided at the lower end of the flux cylinder 2 on the same vertical line as the wire inlet 7, and paste flux is provided in the flux cylinder 2; when the copper wire passes through the flux cylinder 2, the surrounding paste flux will be evenly applied to the surface of the copper wire.

[0037] For further reference, Figure 3 The upper surface of the left cavity 5 is provided with a left air inlet 9, the upper surface of the left cavity 5 is provided with a pressure relief port 10, the upper end of the left surface of the left cavity 5 is provided with a tin adding port 11, and the lower end of the left surface of the left cavity 5 is provided with a tin discharge port 12. The cooling assembly 3 is vertically arranged directly below the sizing die 8; when the copper wire is about to pass through the exit position of the sizing die 8, it can guide the alloy coating of different thicknesses according to the different pressures in the special-shaped tin furnace 1 to form a welding strip with a temperature ranging from 139°C to 190°C.

[0038] Furthermore, the reverse tinning device also includes a traction rod, the diameter of the traction rod is smaller than the diameter of the wire hole of the sizing mold 8, the length of the traction rod is greater than the distance from the wire outlet to the wire inlet 7, and the traction rod is a hard copper wire; the traction rod is used to pull the copper wire that has passed through the flux barrel 2 after annealing through the wire inlet and the mold 8 into the cooling air duct 303, and finally out through the lower positioning wheel.

[0039] Furthermore, a tin plating liquid is provided in the special-shaped tin furnace 1 .

[0040] For further reference, Figure 4 The cooling assembly 3 includes a chiller 301 and a water-cooling cavity. The water-cooling cavity is composed of hollow semi-cylindrical chambers 302 symmetrically arranged on the left and right sides. The hollow semi-cylindrical chambers 302 on the left and right sides are enclosed to form a cooling air duct 303 inside. The cooling air duct 303 is used to vertically pass the welding strip;

[0041] Furthermore, the chiller 301 has a water outlet and a water inlet. The water outlet of the chiller 301 is connected to a hose 304. One end of the hose 304 is divided into two branches. Each branch longitudinally passes through one side of the hollow semi-cylindrical chamber 302 and is connected to the water inlet of the chiller 301.

[0042] Furthermore, the length of the cooling duct 303 is 3-5 meters. The length of the cooling duct 303 is adjustable. Depending on the production speed, which ranges from 500m / min to 800m / min, the duct length ranges from 3 to 5 meters. Only by setting different lengths can the temperature of the soldering ribbon be reduced from the furnace temperature (ranging from 139°C to 190°C, depending on the alloy) to 50°C to 60°C, ensuring that the circumferential surface of the soldering ribbon is not scratched when it contacts the wire wheel in the next step.

[0043] Furthermore, cooling water flows into the hollow semi-cylindrical chambers 302 symmetrically arranged on the left and right sides to cool the pipeline and keep the entire pipeline at a constant temperature.

[0044] Furthermore, solid paste flux is provided in the flux tube 2, and the viscosity of the flux is 0# or 00#. When the copper wire passes through the flux tube 2, the surrounding paste flux will be evenly applied to the surface of the copper wire.

[0045] Furthermore, the diameter of the wire inlet 7 is 20-30 μm larger than the diameter of the copper wire.

[0046] Furthermore, the tin plating solution is a tin-bismuth-silver alloy or a tin-lead alloy, and the temperature is from 139°C to 190°C.

[0047] Furthermore, the special-shaped tin furnace 1 is made of titanium alloy, and the outer layer has constant temperature heating and temperature control functions.

[0048] (2) A method for reverse tinning of a solder strip, comprising the following steps:

[0049] Step 1: Adjust the upper positioning wheel above the flux barrel and the lower positioning wheel below the cooling assembly so that the vertical tangent direction of the upper positioning wheel, the vertical tangent direction of the lower positioning wheel and the center of the sizing die are on the same vertical line;

[0050] Step 2: Pass the traction rod from the wire inlet to the wire outlet, and keep it in both the wire inlet and the wire outlet at the same time; add tin plating liquid into the special-shaped tin furnace and heat it to a molten state; during the manual threading process, there is no or a small amount of molten liquid remaining at the position of the mold hole in the right cavity, which does not affect the manual threading.

[0051] Step 3: Open the pressure relief port of the left cavity and pressurize the right cavity of the special-shaped tin furnace from the air inlet and outlet, so that the tin plating liquid in the right cavity flows into the left cavity under pressure;

[0052] Step 4: The tinned copper wire is released from the pay-off device, thinned by the wire drawing device, and then annealed by the annealing device to become a soft copper wire. The soft copper wire is passed around the upper positioning wheel and then passed through the flux cylinder. It is connected to the upper end of the traction rod and, under the traction of the traction rod, passes through the wire inlet and outlet of the special-shaped tin furnace in sequence, passes through the cooling air duct, and is wound out from the lower positioning wheel to the wire take-up device.

[0053] Step 5: Adjust the thickness of the copper wire surface coating by adjusting the pressure in the left and right cavities. According to the different pressures in the special-shaped tin furnace, guide the alloy coating of different thicknesses; the gas pressure is set to 0.4 to 0.5 MPa. This varies according to the specifications of the production solder strips, with the diameter ranging from 0.2 to 0.35. The mold is replaced, and the pressure required for the solder strip circumference is also different. The surface of the copper strip passing through the tin furnace will adhere to the tin plating liquid, forming a solder strip with a surface temperature of 139°C to 190°C;

[0054] Step 6: Start the pay-off and take-up equipment. The tinned copper wire becomes a tinned solder strip and is taken up onto a reel. The automatic take-up maintains independent take-up and has an automatic reel-changing function.

[0055] Furthermore, in step 4, the temperature of the tinned solder strip coming out of the cooling air duct of the cooling assembly is 50-60°C.

[0056] Furthermore, in step 5, the method for adjusting the thickness of the coating on the surface of the welding strip is: when the coating on the surface of the welding strip is thin, the pressure in the left cavity is increased or the pressure in the right cavity is decreased; when the coating on the surface of the welding strip is thick, the pressure in the left cavity is decreased or the pressure in the right cavity is increased.

[0057] Furthermore, during threading and normal production, the inlet aperture is slightly larger than the copper wire diameter by 20-30μm, resulting in a small amount of air leakage. During operation, the right cavity continuously replenishes air pressure to achieve equilibrium. During the copper wire threading process, a small amount of molten alloy remains in the outlet mold, preventing air leakage.

[0058] Furthermore, during the tinning process of the soldering ribbon, as the copper wire passes through the die, the die is at a certain depth in the liquid, exerting a certain amount of liquid pressure. Combined with the gas pressure, this exerts a certain centripetal pressure in the circumferential direction of the copper wire, allowing the copper wire to be better positioned in the center of the die, resulting in improved concentricity of the soldering ribbon. Furthermore, when producing soldering ribbon using this method, the copper wire runs from top to bottom, and the gravity of the tin alloy also moves from top to bottom, resulting in a lower yield strength and better stability.

[0059] In the above embodiment, the steps for using a reverse tinning device for a solder strip are as follows:

[0060] The first step is to adjust the upper positioning wheel above the flux barrel and the lower positioning wheel below the cooling assembly so that the vertical tangent direction of the upper positioning wheel, the vertical tangent direction of the lower positioning wheel and the center of the sizing die are kept on the same vertical line.

[0061] The second step is to pass the traction rod from the wire inlet to the wire outlet, and keep it inside the wire inlet and the wire outlet at the same time; add tin plating liquid into the special-shaped tin pot and heat it to a molten state; at this time, there is a prefabricated traction rod in the special-shaped tin pot, and the traction rod is clamped at the wire inlet and the wire outlet through the clamping structure, and the tin pot is kept isolated from the outside air.

[0062] The third step is to pressurize the air inlet and outlet of the right cavity of the special-shaped tin furnace, and release some residual pressure at the pressure relief port of the left cavity of the special-shaped tin furnace, so that the tin-lead alloy in the right cavity flows to the left cavity under the action of high-pressure gas.

[0063] The fourth step is to release the tinned copper wire from the wire-paying equipment, thin it through the wire drawing equipment, and then anneal it through the annealing equipment to become a soft copper wire. Then, pass the soft copper wire around the upper positioning wheel and out of the flux barrel. Connect it to the upper end of the traction rod, enter the top of the special-shaped tin furnace, and then pull the copper wire to the bottom of the tin furnace.

[0064] The fifth step is to charge the air inlet of the left cavity of the special-shaped tin furnace and release part of the pressure at the air inlet and outlet of the right cavity until the air pressure on both sides and the height of the tin plating liquid are in a pressure balance position, which means that the normal working position of the tin plating station is reached.

[0065] The sixth step is to start the pay-off equipment and the take-up equipment. The tinned copper wire becomes a tinned solder strip and is taken up onto the wire reel.

[0066] Although the present invention has been described in detail in this specification using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the present invention, are intended to fall within the scope of protection claimed herein.

Claims

1. A reverse tinning device for a soldering strip, used for tinning a copper wire, the reverse tinning device comprising a special-shaped tin pot (1), a flux cylinder (2) and a cooling assembly (3), the special-shaped tin pot (1) having a longitudinal section in the shape of a "concave" character, the special-shaped tin pot (1) comprising a right cavity (4) and a left cavity (5), the bottom of the right cavity (4) being connected to the bottom of the left cavity (5), the upper portion of the right cavity (4) being provided with an air inlet and outlet (6), the upper surface of the right cavity (4) being provided with a wire inlet (7), the lower surface of the right cavity (4) being provided with a wire outlet on the same vertical line as the wire inlet (7), the wire outlet being fixedly connected to a sizing die (8), the middle of the sizing die (8) being provided with a wire hole; A soldering flux cylinder (2) is provided just above the wire inlet (7), a wire hole located on the same vertical line as the wire inlet (7) is provided at the lower end of the soldering flux cylinder (2), and paste soldering flux is provided in the soldering flux cylinder (2); The upper surface of the left cavity (5) is provided with a left air inlet (9), the upper surface of the left cavity (5) is provided with a pressure relief port (10), the upper end of the left surface of the left cavity (5) is provided with a tin addition port (11), the lower end of the left surface of the left cavity (5) is provided with a tin discharge port (12), and the cooling assembly (3) is vertically arranged directly below the sizing die (8); The reverse tinning device further comprises a traction rod, the diameter of the traction rod being smaller than the diameter of the wire hole of the sizing die (8), the length of the traction rod being greater than the distance from the wire outlet to the wire inlet (7), and the traction rod being a hard copper wire; The special-shaped tin furnace (1) is provided with a tin plating liquid; The tin plating solution is a tin-bismuth-silver alloy or a tin-lead alloy; The diameter of the wire inlet (7) is 20-30 μm larger than the diameter of the copper wire.

2. The reverse tinning device for solder strip according to claim 1, characterized in that: The cooling assembly (3) comprises a water chiller (301) and a water-cooling cavity, wherein the water-cooling cavity is composed of hollow semi-cylindrical chambers (302) symmetrically arranged on the left and right sides, wherein the hollow semi-cylindrical chambers (302) on the left and right sides are enclosed to form a cooling air duct (303) inside, and the cooling air duct (303) is used for vertically passing the welding strip; The chiller (301) has a water outlet and a water inlet. The water outlet of the chiller (301) is connected to a hose (304). One end of the hose (304) is divided into two branches. Each branch longitudinally passes through one side of the hollow semi-cylindrical chamber (302) and is connected to the water inlet of the chiller (301).

3. The reverse tinning device for solder strip according to claim 2, characterized in that: The length of the cooling air duct (303) is 3-5 meters.

4. A method for reverse tinning of a solder strip, characterized in that: The reverse tinning device for the solder strip according to claim 1 comprises the following steps: Step 1: Adjust the upper positioning wheel above the flux barrel and the lower positioning wheel below the cooling assembly so that the vertical tangent direction of the upper positioning wheel, the vertical tangent direction of the lower positioning wheel and the center of the sizing die are on the same vertical line; Step 2: Pass the traction rod from the inlet to the outlet, and keep it in both the inlet and outlet at the same time; add tin plating liquid into the special-shaped tin furnace and heat it to a molten state; Step 3: Open the pressure relief port of the left cavity and pressurize the right cavity of the special-shaped tin furnace from the air inlet and outlet, so that the tin plating liquid in the right cavity flows into the left cavity under pressure; Step 4: The tinned copper wire is released from the pay-off device, thinned by the wire drawing device, and then annealed by the annealing device to become a soft copper wire. The soft copper wire is passed around the upper positioning wheel and then passed through the flux cylinder. It is connected to the upper end of the traction rod and, under the traction of the traction rod, passes through the wire inlet and outlet of the special-shaped tin furnace in sequence, passes through the cooling air duct, and is wound out from the lower positioning wheel to the wire take-up device. Step 5, adjusting the thickness of the coating on the surface of the copper wire by adjusting the pressure in the left cavity and the right cavity; Step 6: Start the pay-off equipment and the take-up equipment. The tinned copper wire becomes a tinned solder strip and is taken up onto a reel.

5. The reverse tinning method for a solder strip according to claim 4, characterized in that: In step 4, the temperature of the tinned solder strip coming out of the cooling air duct of the cooling assembly is 50-60°C.

6. The reverse tinning method for a solder strip according to claim 4, characterized in that: In step 5, the method for adjusting the thickness of the coating on the surface of the welding strip is: when the coating on the surface of the welding strip is thin, the pressure in the left cavity is increased or the pressure in the right cavity is decreased; when the coating on the surface of the welding strip is thick, the pressure in the left cavity is decreased or the pressure in the right cavity is increased.

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