Method and equipment for preventing tin whisker from continuously hot-dipping tin alloy on irregular contact pin material

Abstract

The invention relates to the technical field of pin conductor material processing, in particular to a method and equipment for continuous hot dipping of tin alloy on an irregular pin material capable of preventing tin whisker. Performing hot dipping; plating layer control is conducted, specifically, the strip subjected to hot dipping penetrates through a hot dipping mold, and the plating layer thickness is controlled; removing the tin on the side surface of the contact pin, arranging a tin removing mold for blowing the tin on the side surface of the contact pin away from a contact pin body on the outlet side of the hot-dip mold, arranging the tin removing mold on the two sides of the strip, forming an air outlet for forming an air knife on the blowing mold above the strip, and blowing away the condensed tin on the side surface of the contact pin by hot air through the air outlet; the contact pin is manufactured into a continuous strip, after scaling powder coating and hot dipping are conducted, the circumferential thickness of the strip is controlled through a drawing die, then a blowing die is matched with a receiving die, tin liquid hung on the side face of the contact pin is blown off and collected, and the technical problem that the surface quality of the contact pin is affected due to the fact that the tin liquid splashes all around is solved.

Description

Technical Field

[0001] The invention relates to the technical field of pin conductor material processing, and in particular to a method and equipment for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers. Background Art

[0002] Pin products are widely used in the field of electronic devices. They have various shapes. Electroplating of tin, nickel, gold and other coatings can prevent corrosion and increase conductivity. For complex-shaped pin conductors, electroplating can be used, but electroplating of tin will produce tin whiskers. Electroplating of nickel and gold is costly and has low solderability.

[0003] In addition, more and more electronic device solder joints and device surfaces require tin plating and other materials, and at the same time, it is required to prevent the generation of tin whiskers. Hot-dip tin alloy can reduce the generation of tin whiskers. If hot-dip plating is used, for complex pin structures, such as Figure 1 As shown, tinning and uneven plating will occur in the gaps at complex cross-sections. At the same time, single pins cannot be produced continuously and the hot-dip plating process is difficult.

[0004] Chinese patent CN112259628A discloses a method for preparing colored photovoltaic tin-coated copper strips, firstly, oxygen-free copper rods are drawn and extended to bare round copper wires; bare round copper wires are rolled and rolled into hard flat copper strips through multiple passes; hard flat copper strips are subjected to short-circuit annealing to eliminate internal stress and obtain soft flat copper strips; soft flat copper strips are passed through a flux box, tilted into a hot-dip tinning bath, and then vertically drawn out of the hot-dip tinning bath; after the two surfaces of the copper strips are coated with tin alloy, tin blowing air knives are respectively arranged on the left and right sides of the upper end in the vertical direction of the tin bath position, and the air pressure of the left and right tin blowing air knives is respectively adjusted by air pressure valves to control the thickness of the tin alloy solder coating on the two surfaces of the copper strips, forming a tin-coated copper strip with a thick tin alloy solder coating on one side and a thin tin alloy solder coating on the other side; then the second side is subjected to corona surface treatment to form a corona surface, a layer of coloring coating is applied to the surface of the corona surface to form a colored surface, heated and dried to solidify, cooled to room temperature, rolled up, and packaged. Reduce production costs and improve quality stability.

[0005] Although this technical solution discloses the use of an air knife to control the thickness of the coating, when an air knife with a blown structure is used for a pin structure strip with a complex shape, the tin liquid adhering to the side wall will splash everywhere, causing bumps to appear on the coating surface, making it impossible to use the subsequent pins normally. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and provide a method for continuous hot-dip tin-alloy plating of irregular pin materials to prevent tin whiskers. The pin's anti-tin whisker function is achieved by hot-dip plating of a tin-based alloy on the pin surface. The pin is made into a continuous strip, and after flux coating and hot-dip plating, a drawing die is first used to control the circumferential thickness of the strip. Then, a blowing die is used in conjunction with a receiving die to blow off and collect the tin liquid hanging on the side of the pin, thereby avoiding the technical problem of tin liquid splashing everywhere and affecting the surface quality of the pin.

[0007] To achieve the above object, the present invention provides the following technical solutions: A method for continuous hot-dip tin alloy plating of irregular pin materials to prevent tin whiskers, characterized by comprising the following steps: Step 1: Flux coating: The continuously formed pin conductor strip passes through the flux coating device to complete the flux coating; Step 2, hot dip plating: the strip coated with solder flux in step 1 enters the tinning pool containing molten tin alloy through a guiding device, and the strip pressing wheel presses the strip into the tinning pool for hot dip plating of tin alloy; Step 3: Coating control: The hot-dip coated strip passes through a hot-dip coating die to control the coating thickness; Step 4: Removal of tin on the side of the pin: A tin removal mold for blowing the tin on the side of the pin away from the pin body is provided on the outlet side of the hot-dip galvanizing mold. The tin removal mold is provided on both sides of the strip. An air outlet for forming an air knife is provided on the blowing mold above the strip. The hot air blows away the tin condensed on the side of the pin through the air outlet. Step 5: Cooling and coiling: After step 4, the strip is cooled by a cooling device and then coiled by a coiling device.

[0008] As an improvement, the tin alloy is any one of tin-silver-copper alloy, tin-silver alloy, tin-copper alloy and tin-bismuth alloy which can prevent the growth of tin whiskers.

[0009] As an improvement, the air outlet direction of the blowing mold is arranged perpendicular to the strip conveying direction.

[0010] As an improvement, in step 4, a receiving mold with a negative pressure structure is provided below the strip to collect the small tin particles blown off from the air outlet.

[0011] As an improvement, the outline of the air outlet is a straight structure or an outline structure surrounded by side surfaces of adjacent pins.

[0012] As an improvement, a baffle is provided below the blowing mold to guide the blown-off alloy liquid to the inside of the tinning pool; the baffle prevents the high-pressure gas from blowing away the tin alloy liquid inside the tinning pool.

[0013] As an improvement, the pin conductor strip is formed by stamping copper or copper alloy into a semi-finished pin conductor shape using a mold, and a plurality of semi-finished pin conductors are connected to form a strip.

[0014] Another object of the present invention is to provide a device for continuous hot-dip tin alloy plating of irregular pin materials to prevent tin whiskers in response to the shortcomings of the prior art. After using a drawing die to control the coating thickness on the strip surface, a detinning die is arranged at the outlet of the drawing die. The air outlet direction of the air outlet is arranged perpendicular to the strip transmission direction. At the same time, the detinning die is blown off by blowing up and sucking down, so that the tin liquid on the side of the pin is blown off and the coating thickness on the side of the pin is controlled by a wind knife, thereby realizing continuous hot-dip plating of high-quality complex-section pins and solving the technical problem of poor quality of hot-dip plating of complex-section pins in the prior art.

[0015] To achieve the above object, the present invention provides the following technical solutions: A device for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers, used to implement the above-mentioned method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers, the device comprises an unwinding device, a flux coating device, a hot-dip plating device, a cooling device and a winding device arranged in sequence, characterized in that the hot-dip plating device comprises: A tin-plating bath, which is used to melt the raw materials to be hot-dip plated; An adjusting device, which is used to change the depth of the strip immersed in the tinning bath, can be adjusted on the tinning bath; A hot-dip die for controlling the coating thickness is disposed at the discharge end of the tinning pool. After the strip passes through the hot-dip die, the coating thickness is controlled by the hot-dip die; A tin removal mold, which can be adjusted to be arranged on one side of the hot-dip galvanizing mold; A baffle is tilted on one side of the detinning mold, and a lower end of the baffle is located below the detinning mold; a liquid reflux channel is formed between the baffle and the hot-dip die.

[0016] As an improvement, the detinning mold comprises: A movable seat, the movable seat is slidably arranged on the tin-plating pool, and two sets of positioning grooves are opened on the side of the movable seat; An adjustment plate, wherein the adjustment plate is mounted on the movable seat through two sets of positioning grooves, and the two sets of positioning grooves are used to change the installation angle of the adjustment plate; A blowing mold, which is arranged above the strip and connected to one end of the adjusting plate, and is provided with an air inlet and an air outlet; the air outlet direction of the air outlet is arranged perpendicular to the conveying direction of the strip; The receiving mold is arranged below the strip and connected to one end of the adjusting plate, and is provided with a material receiving port and an air suction port.

[0017] As an improvement, the outline of the air outlet is a straight structure or an outline structure surrounded by side surfaces of adjacent pins.

[0018] The beneficial effects of the present invention are: (1) The present invention solves the problem of poor efficiency of hot-dip plating of single pins by manufacturing the pins as continuous semi-finished strips and utilizing the continuity of the strips for hot-dip plating. At the same time, the material for hot-dip plating is selected as a tin-based alloy to achieve tin whisker prevention of the pins.

[0019] (2) After the present invention uses the drawing die to control the coating thickness on the surface of the strip, a detinning die is arranged at the outlet of the drawing die. The air outlet direction of the air outlet is arranged perpendicular to the strip transmission direction. At the same time, the detinning die is blown up and sucked down to blow off the tin liquid on the side of the pin and use the wind knife to control the coating thickness on the side of the pin, thereby realizing continuous hot-dip plating of high-quality complex-section pins, ensuring that the coating thickness on the surface and side of the pin conductor remains consistent, and realizing high-quality hot-dip alloy on the surface of the pin conductor.

[0020] (3) The present invention immerses one end of the drawing die into the molten metal, thereby preventing impurities on the surface of the molten metal from adhering to the surface of the strip during the hot dip plating process, thereby affecting the surface quality of the coating.

[0021] (4) The present invention realizes the adjustment of different strip thicknesses, positions, and angles by cooperating with the adjusting plate through the movable seat, thereby improving the adaptability of the equipment.

[0022] (5) The present invention forms an air knife through the air outlet of the blowing mold, and the shape of the air knife matches the contour between two adjacent pins. The sensor detects the position of the pin and blows off the tin liquid on the side of the pin at a fixed point, thereby achieving high-quality pin surface plating control.

[0023] (6) The present invention periodically discharges the tin particles in the storage bin through the discharge assembly to achieve the reuse of raw materials. At the same time, in the process of cleaning the tin particles by pushing the plate, the normal continuous production of hot dip plating is not affected.

[0024] (7) The present invention realizes the recycling of flux through the flux coating device, and uses a scraper to evenly coat the flux on the surface of the strip, thereby improving the quality of subsequent hot-dip plating.

[0025] (8) The present invention realizes continuous cooling of the strip through a cooling device. At the same time, low-temperature circulating water flows downward from the top, so that the strip is cooled step by step and the strip is cooled evenly, thereby preventing the high-temperature strip from contacting the colder cooling water and affecting the quality of the strip.

[0026] In summary, the present invention has the advantages of being able to hot-dip plate a pin conductor with a complex cross-section while ensuring the uniformity of the plating layer on the surface of the pin conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Improve the surface quality of the coating after ordinary hot-dip plating for complex structure pins; Figure 2 This is a schematic diagram of the process flow of Example 1 of the present invention; Figure 3 A schematic diagram of the strip structure formed by the semi-finished pin conductor of the present invention; Figure 4 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 5 It is a schematic diagram of the hot dip coating device of the present invention; Figure 6 For the present invention Figure 5 The local enlarged schematic diagram of point I in the middle; Figure 7 The tin removal mold of the present invention is shown in FIG. Figure 1 ; Figure 8 The tin removal mold of the present invention is shown in FIG. Figure 2 ; Fig. 9 This is a schematic diagram of the air outlet structure at the bottom of the blowing mold of the present invention; Fig.10 This is a schematic diagram of the receiving mold structure of the present invention; Fig.11 This is a schematic diagram of the internal structure of the receiving mold of the present invention; Fig.12 It is a schematic diagram of the molten liquid level and the position of the drawing die in the tinning pool of the present invention; Fig.13 It is a schematic diagram of the flux coating device of the present invention; Fig.14 It is a schematic diagram of the cooling device of the present invention; Fig.15 For the present invention Fig.14 A partial enlarged schematic diagram of point II in the middle. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0030] Embodiment 1 like Figure 2 As shown, this embodiment provides a method for continuous hot-dip tin alloy plating of irregular pin materials to prevent tin whiskers, comprising the following steps: Step 1: Applying flux: The continuously formed pin conductor strip 100 is passed through a flux applying device to complete the application of flux; Step 2, hot-dip plating: the strip 100 coated with solder flux in step 1 enters the tinning pool 31 containing molten tin alloy through a guiding device, and the strip 100 pressing wheel 322 presses the strip 100 into the tinning pool 31 for hot-dip plating of tin alloy; Step 3: coating control: the strip 100 after hot dip coating passes through a hot dip coating die 33 for controlling coating thickness, and the coating thickness is controlled; Step 4: Removal of tin on the side of the pin: A tin removal mold 34 is provided on the outlet side of the hot-dip die 33 to blow the tin on the side of the pin away from the pin body. The tin removal mold 34 is provided on both sides of the strip 100. An air outlet 3432 for forming an air knife is provided on the tin removal mold 34. The hot air blows away the tin condensed on the side of the pin through the air outlet 3432. Step 5, cooling and coiling: after step 4, the strip 100 is cooled by the cooling device 4 and then coiled by the coiling device 5; Step 6: Pin separation: The rolled strip 100 is separated one by one by stamping.

[0031] It should be noted that before the flux application step, a degreasing step of cleaning the strip 100 is also included to ensure the surface quality of the strip 100 and improve the hot dip plating effect. This step is a conventional method and will not be repeated in this application.

[0032] As an improvement, the tin alloy is any one of tin-silver-copper alloy, tin-silver alloy, tin-copper alloy and tin-bismuth alloy which can prevent the growth of tin whiskers.

[0033] As an improvement, the detinning mold 34 includes a blowing mold 343 arranged above the strip 100 and a receiving mold 344 arranged below the strip 100. The air outlet direction of the blowing mold 343 is arranged perpendicular to the transmission direction of the strip 100. The receiving mold 344 is provided with a material receiving channel, and the material receiving channel is in a negative pressure state.

[0034] As an improvement, the outline of the air outlet 3432 is a straight structure or an outline structure surrounded by the side surfaces of adjacent pins.

[0035] As an improvement, the outlet pressure of the blowing mold 343 can blow off the uncondensed alloy liquid on the side of the pin, and the appropriate air pressure is selected according to the different widths of the strip 100.

[0036] As an improvement, a baffle 35 is provided below the blowing mold 343 to guide the blown-off alloy liquid to the inside of the tin-plating pool 31 ; the baffle 35 prevents the high-pressure gas from blowing away the tin alloy liquid inside the tin-plating pool 31 .

[0037] It should be noted that the baffle 35 is tilted, and the lower end is located below the hot-dip die 33, so that the blown-off tin alloy liquid / particles flow back into the tinning pool 31 for reuse.

[0038] As an improvement, the pin conductor strip 100 is formed by stamping copper or copper alloy into a semi-finished pin conductor shape using a mold. At the same time, several semi-finished pin conductors are connected to form a pin conductor strip 100 of a longer length, and the strip 100 can be pulled out at a uniform speed through a tinning mold.

[0039] Embodiment 2 like Figure 3-Figure 15 As shown, this embodiment provides a device for continuous hot-dip tin alloy plating of irregular plug materials for preventing tin whiskers, which is used to implement a method for continuous hot-dip tin alloy plating of irregular plug materials for preventing tin whiskers as described in Example 1. The device comprises an unwinding device 1, a flux coating device 2, a hot-dip plating device 3, a cooling device 4 and a winding device 5 which are arranged in sequence. The hot-dip plating device 3 comprises: A tin-plating pool 31, wherein the tin-plating pool 31 is used to melt the raw materials to be hot-dip plated; An adjusting device 32, which is used to change the depth of the strip 100 immersed in the tin-plating pool 31, can be adjusted on the tin-plating pool 31; the adjusting device 32 can be adjusted on the left and right sides of the tin-plating pool 31; A hot-dip die 33 for controlling the coating thickness is disposed at the discharge end of the tin-plating pool 31. After the strip 100 passes through the hot-dip die 33, the coating thickness is controlled by the hot-dip die 33. One end of the hot-dip die 33 extends below the liquid surface of the molten liquid in the tin-plating pool 31 to prevent oxides on the surface of the molten liquid from adhering to the coating surface, thereby improving the surface quality of the coating. A tin removal mold 34, which can be adjusted to one side of the hot-dip mold 33; The baffle plate 35 is tilted on one side of the detinning mold 34 , and a lower end of the baffle plate 35 is located below the detinning mold 34 ; a liquid reflux channel is formed between the baffle plate 35 and the hot-dip mold 33 .

[0040] As an improvement, the adjusting device 32 includes: a supporting plate 321 movably arranged along the material flow direction and a pressing wheel 322 adjustable up and down on the supporting plate 321 .

[0041] Specifically, the support plate 321 is movably arranged along the flow direction of the strip 100 through a sliding rod 323 and a slide groove. At the same time, the sliding rod 323 changes the height position of the support plate 321 through upper and lower fasteners; the pressure wheel 322 is connected through an adjusting rod 324, and the adjusting rod 324 is slidably arranged on the support plate 321. A fastener for fastening the adjusting rod 324 is provided on one side of the support plate 321.

[0042] Preferably, the hot-dip galvanizing die 33 includes an angle-adjustable mounting plate 331 and a drawing die 332 disposed on the mounting plate 331 for controlling the coating thickness. Different drawing dies 332 are adapted according to different shapes of the strip 100. For example, a rectangular cross-section is selected for the strip 100, a circular cross-section is selected for the round wire, and a rectangular cross-section is selected for the rectangular wire, so as to improve the versatility of the equipment. The feeding end of the drawing die 332 is a bell-mouth structure, which is convenient for feeding the strip 100.

[0043] Specifically, the mounting plate 331 is rotatably mounted on the tin plating pool, and a positioning hole for controlling the angle of the mounting plate 331 is provided above the mounting plate 331. By changing the position of the positioning hole, the angle of the mounting plate 331 relative to the tin plating pool 31 is changed; one end of the mounting plate 331 is immersed in the molten alloy liquid in the tin plating pool 31, so that the mounting plate 331 has a certain temperature, and at the same time, the drawing die 332 installed on the mounting plate 331 maintains a certain temperature, thereby improving the control accuracy of the coating thickness. In addition, it can also ensure that the lower end of the drawing die 332 is immersed in the alloy liquid to prevent impurities on the surface of the liquid from affecting the surface quality of the strip 100 after hot dip plating.

[0044] Embodiment 3 like Figure 7-Figure 11As shown, the components identical or corresponding to those in the second embodiment are marked with the corresponding reference numerals in the second embodiment. For the sake of simplicity, only the differences from the second embodiment are described below. The difference between the third embodiment and the second embodiment is that: In this embodiment, the detinning mold 34 includes: A movable seat 341, the movable seat 341 is slidably disposed on the tin-plating pool 31, and two sets of positioning grooves 3411 are provided on its side; specifically, a guide groove is provided on the movable seat 341, and a sliding channel adapted to the movable seat 341 is provided at one end of the tin-plating pool 31, and guide rails matching the guide groove are provided on both sides of the sliding channel; An adjustment plate 342, wherein the adjustment plate 342 is installed on the movable seat 341 through two sets of positioning grooves 3411, and the two sets of positioning grooves 3411 are used to change the installation angle of the adjustment plate 342; The blowing mold 343 is arranged above the strip 100 and connected to one end of the adjusting plate 342. The blowing mold 343 is provided with an air inlet 3431 and an air outlet 3432. The air outlet 3432 is arranged in a direction perpendicular to the transmission direction of the strip 100. The air outlet 3432 is a small gap structure. When the high-pressure gas passes through the air outlet 3432, a wind knife is formed to blow off the tin liquid hanging on the side of the pin. The receiving mold 344 is arranged below the strip 100 and connected to one end of the adjusting plate 342. The receiving mold 344 is provided with a material receiving port 3441 and an air suction port 3442. Specifically, the air suction port 3442 is connected to the negative pressure device to form a negative pressure state in the mold cavity of the receiving mold 344, so as to collect the small tin particles or small tin droplets blown off by the blowing mold 343, so as to prevent the small particles or droplets blown off from flying around and affecting the surface quality of the pins.

[0045] Preferably, the outline of the air outlet 3432 is a straight structure or an outline structure surrounded by the side surfaces of adjacent pins.

[0046] It should be noted that the straight structure can achieve continuous and uninterrupted production, which is more suitable for pin contours with less complex shapes.

[0047] When the shape of the pins is more complicated, the air outlet structure formed by the outline between the two groups of pins is used in conjunction with the setting of the sensor to achieve fixed-point blowing, so that the two groups of pins are kept below the air outlet, so that the junction of the two groups of pins is just below the air outlet, and the high-pressure gas blown out of the air outlet is used to blow away the tin liquid between the two groups of pins. At the same time, the thickness of the tin liquid on the side of the pin can be guaranteed.

[0048] Preferably, the material receiving port 3441 is arranged in a trumpet-mouth structure, and an air suction channel 3443 and a material storage bin 3444 are arranged at the bottom of the material receiving port 3441. The air suction channel 3443 is arranged at the connection between the top of the material storage bin 3444 and the material receiving port 3441, so as to realize that the solidified small tin particles fall into the material storage bin 3444 and prevent the small tin particles from being sucked into the air suction channel 3443.

[0049] Embodiment 4 like Fig.10 , Fig.11 As shown, the components identical or corresponding to those in the second embodiment are marked with the corresponding reference numerals in the second embodiment. For the sake of simplicity, only the differences from the second embodiment are described below. The fourth embodiment differs from the second embodiment in that: In this embodiment, the detinning mold 34 further includes a discharge assembly 345 for discharging the small tin particles or small tin droplets collected by the receiving mold 344 out of the storage bin 3444; The material storage bin 3444 is arranged to pass through the receiving mold 344, and a bin door 3445 is rotatably provided at one end for closing the material storage bin 3444; the bin door 3445 is an automatic closing bin door 3445, and a return spring is installed at the rotating shaft of the bin door 3445 to ensure that the bin door 3445 always abuts against the side wall of the material storage bin 3444, and the air suction channel 3443 is always in a sealed state; The discharge assembly 345 includes: A push plate 3451 is slidably disposed in the storage bin 3444, and the push plate 3451 pushes the particles in the storage bin 3444 out through the bin door 3445; The driving component 3452 drives the push plate 3451 to move back and forth. The driving component 3452 is preferably driven by a cylinder, which is arranged on one side of the detinning mold. The protruding end of the cylinder is connected to the push plate 3451, driving the push plate 3451 to move back and forth.

[0050] Furthermore, the top surface of the push plate 3451 is aligned with the bottom surface of the air suction channel 3443. When the push plate 3451 is pushed forward, the normal operation of the air suction channel 3443 is not affected, that is, the continuous production of the strip 100 is not affected. When the push plate 3451 is pushed to the front of the bin door 3445, the push plate 3451 just blocks the side wall of the storage bin 3444 and the air suction channel 3443. At the same time, a certain material storage space is left between the front end of the push plate 3451 and the bin door 3445. When the push plate 3451 continues to be pushed forward, the push plate 3451 pushes the bin door 3445 open, and at the same time, the granular material in the material storage space is pushed out onto the baffle plate 35, and rolls down along the baffle plate 35 into the tinning pool 31 for reuse. When the push plate 3451 moves backward, during the continuous production process, the particles falling on the top of the push plate 3451 are scraped into the storage bin 3444 again through the inner wall of the receiving mold 344.

[0051] Furthermore, the blowing mold 343 is also provided with a sensor 346 for detecting the position of the pin. The sensor 346 is connected to the controller signal for controlling the operation of the entire line. When the sensor 346 detects that one side of the pin is aligned with one side of the air outlet 3432, a signal is sent out, and the strip 100 stops transmitting, so that the gap between the two groups of pins is located directly below the blowing port. The blowing mold 343 blows out high-pressure gas along the air outlet 3432 to blow off the tin liquid on the side of the pin, and the strip 100 continues to move until the next time the sensor 346 detects the pin position, and the above process is repeated to achieve intermittent blowing away of the tin liquid, thereby achieving side thickness control of the pin, while ensuring that there is no tin hanging phenomenon at complex cross-sections and ensuring that the coating thickness at the corresponding position meets the process requirements.

[0052] Embodiment 5 like Fig.13 As shown, the components identical or corresponding to those in the second embodiment are marked with the corresponding reference numerals in the second embodiment. For the sake of simplicity, only the differences from the second embodiment are described below. The difference between the fifth embodiment and the second embodiment is that: In this embodiment, the flux coating device 2 includes: a flux storage tank 21 and reflow tanks 22 arranged on both sides of the flux storage tank 21; the flux storage tank 21 stores flux, and the strip 100 passes through the flux storage tank 21 to complete the flux coating; Specifically, the flux storage tank 21 and the reflow tank 22 are provided with a channel for the strip 100 to pass through; the bottom of the reflow tank 22 is provided with a first reflow hole 221, and the bottom of the flux storage tank 21 is provided with a flux reflow tank 22; the flux in the flux storage tank 21 enters the reflow tank 22 through the strip 100 channels opened on both sides, and flows back into the flux reflow tank 22 through the first reflow hole 221, and the flux in the flux reflow tank 22 is pumped into the flux storage tank 21, so that the flux is recycled and the flux coating is completed without changing the transmission path of the strip 100. In the production process, the flow rate is controlled to ensure that the liquid level in the flux storage tank is higher than the strip 100, so as to ensure the coating effect of the strip 100.

[0053] Furthermore, a scraper 23 for evenly applying the flux is provided on the discharge side of the strip 100. The scraper 23 is provided on the upper and lower sides of the strip 100 to remove excess flux from the surface of the strip 100 coated with flux, thereby ensuring uniform coating of the flux. The scraper 23 is preferably made of a flexible material, such as felt, sponge, etc.

[0054] Embodiment 6 like Figure 14-15 As shown, the components identical or corresponding to those in the second embodiment are marked with the corresponding reference numerals in the second embodiment. For the sake of simplicity, only the differences from the second embodiment are described below. The difference between the fifth embodiment and the second embodiment is that: In this embodiment, the cooling device 4 includes: a cooling trough 41, wherein the cooling trough 41 is arranged in several groups obliquely upward along the conveying direction of the strip 100, and the side wall of the cooling trough 41 is provided with a penetrating cooling channel for the strip 100 to pass through. The cooling trough 41 is provided with a multi-stage cooling zone, and a second reflux hole 42 is provided at the bottom of the cooling zone at the bottom end. A water storage tank is provided at the bottom of the cooling trough 41, and the cooling water refluxed by the second reflux hole 42 enters the water storage tank. The circulating water in the water storage tank is pumped into the top of the cooling trough 41, and the cooling water at the top flows downward step by step through the cooling channel to cool the strip 100 passing through the cooling channel, and flows back to the water storage tank through the second reflux hole 42.

[0055] Furthermore, a drying component 43 for air-drying the strip 100 is provided at the end of the cooling tank 41 .

[0056] The drying component 43 is slidably disposed on the cooling tank 41 , and the drying component 43 includes a blowing die head 431 , and the blowing die head 431 is disposed on both sides of the strip 100 to perform a synchronous blowing drying process on both sides of the strip 100 .

[0057] Furthermore, a guide wheel 44 is provided on the outer side of the cooling trough 41 to guide the cooled strip 100 to the winding assembly; in addition, the strip 100 is positioned at the center of the drawing die 332 by the guide wheel 44 and the pressure wheel 322 to ensure the uniformity of the coating of the strip 100.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for continuous hot-dip tin alloy plating of irregular pin materials to prevent tin whiskers, characterized in that: The following steps are involved: Step 1: Applying flux: The continuously formed pin conductor strip (100) is passed through a flux applying device to complete the application of flux; Step 2: hot-dip plating: the strip (100) coated with solder flux in step 1 enters a tinning pool (31) containing molten tin alloy through a guiding device, and a strip (100) pressing wheel (322) presses the strip (100) into the tinning pool (31) for hot-dip plating of tin alloy; Step 3: coating control: the strip (100) that has completed hot dip coating passes through a hot dip coating die (33) for controlling coating thickness, thereby controlling coating thickness; Step 4, removing tin from the side of the pin: a tin removal mold (34) for blowing the tin on the side of the pin away from the pin body is provided on the outlet side of the hot-dip die (33), the tin removal mold (34) being provided on both sides of the strip (100), and an air outlet (3432) for forming an air knife is provided on the blowing mold (343) above the strip (100), and hot air blows away the tin condensed on the side of the pin through the air outlet (3432); Step 5: Cooling and coiling: After step 4 is completed, the strip (100) is cooled by the cooling device (4) and then coiled by the coiling device (5).

2. The method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 1, characterized in that: The tin alloy is any one of a tin-silver-copper alloy, a tin-silver alloy, a tin-copper alloy, and a tin-bismuth alloy capable of preventing the growth of tin whiskers.

3. The method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 1, characterized in that: The air outlet direction of the blowing mold (343) is arranged perpendicular to the conveying direction of the strip (100).

4. The method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 1, characterized in that: In step 4, a receiving mold (344) with a negative pressure structure is provided below the strip (100) to collect the small tin particles blown off from the air outlet (3432).

5. The method for continuous hot-dip tin alloy plating of irregular pin materials to prevent tin whiskers according to claim 1, characterized in that: The outline of the air outlet (3432) is a straight-line structure or an outline structure formed between the side surfaces of adjacent pins.

6. The method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 1, characterized in that: A baffle (35) is provided below the blowing mold (343) to guide the blown-off alloy liquid into the interior of the tin-plating pool (31); the baffle (35) prevents the high-pressure gas from blowing away the tin alloy liquid in the tin-plating pool (31).

7. The method for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 1, characterized in that: The pin conductor strip (100) is formed by stamping copper or copper alloy into a semi-finished pin conductor shape using a die, and a plurality of semi-finished pin conductors are connected to form the strip (100).

8. A device for continuous hot-dip tin alloy plating of irregular plug pin materials for preventing tin whiskers, used to implement a method for continuous hot-dip tin alloy plating of irregular plug pin materials for preventing tin whiskers as claimed in any one of claims 1 to 7, the device comprising an unwinding device (1), a flux coating device (2), a hot-dip plating device (3), a cooling device (4) and a winding device (5) arranged in sequence, characterized in that: The hot dip coating device (3) comprises: A tin-plating pool (31), wherein the tin-plating pool (31) is used to melt raw materials to be hot-dip plated; An adjusting device (32) for changing the depth of the strip (100) immersed in the tinning pool (31); the adjusting device (32) can be adjusted on the tinning pool (31); A hot-dip die (33) for controlling the thickness of a coating, the hot-dip die (33) being arranged at a discharge end of the tinning pool (31); after the strip (100) passes through the hot-dip die (33), the thickness of the coating is controlled by the hot-dip die (33); A tin removal mold (34), wherein the tin removal mold (34) can be adjustably arranged on one side of the hot-dip coating mold (33); A baffle (35) is arranged obliquely on one side of the detinning mold (34), with a lower end of the baffle being located below the detinning mold (34); a liquid reflux channel is formed between the baffle (35) and the hot-dip galvanizing mold (33).

9. The device for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 8, characterized in that: The detinning mold (34) comprises: A movable seat (341), the movable seat (341) being slidably disposed on the tin-plating pool (31), and having two groups of positioning grooves (3411) formed on its side; An adjustment plate (342), wherein the adjustment plate (342) is installed on the movable seat (341) via two sets of positioning grooves (3411), and the installation angle of the adjustment plate (342) is changed by using the two sets of positioning grooves (3411); A blowing mold (343), the blowing mold (343) is arranged above the strip (100) and connected to one end of the regulating plate (342), and is provided with an air inlet (3431) and an air outlet (3432); the air outlet direction of the air outlet (3432) is arranged perpendicular to the transmission direction of the strip (100); A receiving mold (344) is disposed below the strip (100) and connected to one end of the adjustment plate (342), and is provided with a material receiving port (3441) and an air suction port (3442).

10. The device for continuous hot-dip tin alloy plating of irregular pin materials for preventing tin whiskers according to claim 9, characterized in that: The outline of the air outlet (3432) is a straight-line structure or an outline structure formed between the side surfaces of adjacent pins.

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