Circuit board tin plating system for circuit board chip welding

Abstract

The invention discloses a circuit board tin plating system for circuit board chip welding, and relates to the field of circuit board tin plating, the circuit board tin plating system comprises a tin liquid tank, a local tin plating mechanism is arranged above the tin liquid tank, the local tin plating mechanism comprises a tin plating plate, a tin plating tank is arranged on the top surface of the tin plating plate, and a plurality of tin plating columns are fixed in the tin plating tank; the tinning columns correspond to chip welding positions of the circuit board in a one-to-one mode, tin passing holes are formed in the top faces of the tinning columns in a penetrating mode and penetrate through the bottom of the tinning plate, the top faces of the tinning columns are lower than the top face of the tinning plate, a tin containing cavity is formed in the position, below the tinning groove, of the tinning plate, and a plurality of round holes are formed in the inner bottom wall of the tinning groove and communicated with the tin containing cavity. Tin discharging holes are formed in the side wall of the tin-plated plate, the height of the tin discharging holes is larger than that of the top faces of the tin-plated columns, tin discharging path holes are formed in the tin-plated plate, the two ends of each tin discharging path hole communicate with the corresponding tin discharging hole and one end of the corresponding tin containing cavity correspondingly, tin layers are coated on the multiple chip welding positions of the circuit board at a time, and automatic tin plating operation of the circuit board is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board tinning, in particular to a circuit board tinning system for circuit board chip welding. Background Art

[0002] Circuit boards are crucial electronic components, supporting electronic components and providing electrical connections. Printed circuit boards have evolved from single-layer to double-sided, multi-layer, and flexible, each maintaining its own development trends. Due to the continuous advancements in precision, density, and reliability, along with continuous reductions in size, cost reductions, and performance improvements, printed circuit boards will maintain their strong vitality in the future of electronic equipment. In integrated circuit production, chips must be soldered to circuit boards. To ensure good solderability, the chip soldering areas on the circuit board must be tinned before soldering, providing a highly solderable metal layer. However, unlike chip soldering, tinning on circuit boards requires a thinner tin layer. Excessive tin coating can affect the height of the chip after soldering, hindering subsequent circuit board assembly accuracy and resulting in wasted tin liquid. However, soldering guns, with their high tin coating capacity, are unable to fully tin the chip soldering areas. Therefore, this process is largely manual, with manual application of tin liquid, resulting in harsh working environments, high labor costs, and low efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a circuit board tinning system for circuit board chip welding to solve the deficiencies of the prior art.

[0004] The objective of the present invention is achieved through the following technical solutions: A circuit board tinning system for circuit board chip soldering, comprising a tin liquid tank, a local tinning mechanism is arranged above the tin liquid tank, the local tinning mechanism comprises a tin-plating plate, a tin-plating tank is provided on the top surface of the tin-plating plate, a plurality of tin-plating columns are fixed in the tin-plating tank, and the plurality of tin-plating columns correspond to the chip soldering positions of the circuit board one by one, a tin-through hole is provided through the top surface of the tin-plating column, the tin-through hole passes through the bottom of the tin-plating plate, the top surface height of the tin-plating column is lower than the top surface height of the tin-plating plate, a tin-containing cavity is provided below the tin-plating tank, a plurality of circular holes are provided on the inner bottom wall of the tin-plating tank, the circular holes are connected to the tin-containing cavity, a tin-draining hole is provided on the side wall of the tin-plating plate, the height of the tin-draining hole is higher than the top surface height of the tin-plating column, a tin-draining path hole is provided in the tin-plating plate, and the two ends of the tin-draining path hole are respectively connected to the tin-draining hole and one end of the tin-containing cavity.

[0005] Furthermore, a plurality of tinned bars are fixed on the top of the tinned column, and the plurality of tinned bars correspond one-to-one to a plurality of chip pin soldering positions in the chip soldering position.

[0006] Furthermore, the top surface of the tin-plated column forms a tin-discharging slope between two adjacent tin-plated strips, and the height of the tin-discharging slope gradually decreases in a direction away from the tin-passing hole.

[0007] Furthermore, a tin-discharging piston is slidingly provided in the tin-containing cavity, and two wire holes are opened on the top surface of the tin-plated plate on one side of the tin-plating tank, one of the wire holes is connected to the tin-discharging path hole, and the other wire hole is connected to the other end of the tin-containing cavity. A driving block is slidingly provided on the top surface of the tin-plated plate on the other side of the tin-plating tank, and the driving block moves along the length direction of the tin-containing cavity. Both ends of the driving block are connected to steel wire ropes, and one of the steel wire ropes passes through one of the wire holes and is connected to one end of the tin-discharging piston, and the other steel wire rope passes through the other wire hole and is connected to the other end of the tin-discharging piston.

[0008] Furthermore, the local tinning mechanism also includes a tinning frame and a lifting cylinder. The lifting cylinder is vertically installed on the tinning frame. The telescopic shaft of the lifting cylinder is connected to a driving vertical rod. A horizontal beam is fixed to the side wall of the tinning plate close to the driving block. The bottom end of the driving vertical rod is connected to the horizontal beam through a flange.

[0009] Furthermore, a driving cross plate is fixed on the tin-plated frame, and a screw groove is provided on the driving cross plate in the moving direction of the driving block, and the screw groove runs through the height direction of the driving cross plate, and a screw is rotatably arranged in the screw groove, and a screw slider is threadedly mounted on the screw, and the screw slider is slidably adapted to the screw groove, and a driving rod is fixed to the bottom of the screw slider, and a small diameter hole and a large diameter hole are provided at the bottom of the driving rod from bottom to top, and a disc is slidably adapted in the large diameter hole, and the diameter of the disc is larger than the diameter of the small diameter hole, and a sliding rod is slidably adapted in the small diameter hole, one end of the sliding rod is fixedly connected to the disc, and a mounting disc is fixed to the other end, and the mounting disc is connected to the driving block by screws, and a motor is installed on the driving cross plate, and the output shaft of the motor is connected to the screw rod for transmission.

[0010] Furthermore, a U-shaped frame is provided directly above the wire hole, and the closed end of the U-shaped frame is fixedly connected to the tin-plated plate through a plate, and a first guide wheel is rotatably provided in the U-shaped mouth of the U-shaped frame, and the axis of the first guide wheel is arranged horizontally, and two second guide wheels are arranged on the tin-plated plate along the moving direction of the driving block, and the driving block is located between the two second guide wheels, and the axis of the second guide wheel is arranged vertically, wherein one of the steel wire ropes passes around one of the first guide wheels and one of the second guide wheels is connected to one end of the driving block, and the other steel wire rope passes around the other first guide wheel and the other second guide wheel is connected to the other end of the driving block, so as to arrange the steel wire rope around the tin-plated trough.

[0011] Furthermore, a long screw rod and a guide rod are arranged in parallel in the tin liquid tank, and the long screw rod and the guide rod are both located on one side of the tin-plated plate. A tin scraper slide is threadedly mounted on the long screw rod, and the tin scraper slide is slidably mounted on the guide rod. An L-shaped scraper is fixed to the side of the tin scraper slide close to the tin-plated plate, and metal scrapers are fixed on the top and bottom surfaces of the horizontal section of the L-shaped scraper. The two metal scrapers respectively scrape off the tin layer on the tin liquid surface and the tin layer on the bottom of the tin-plated plate. A driving motor is arranged away from the tin liquid tank, and the output shaft of the driving motor is connected to a driving sprocket. One end of the long screw rod is connected to a driven sprocket, and the driven sprocket is connected to the driving sprocket through a chain transmission.

[0012] Furthermore, an annular heating cavity is provided in the tinplate around the tinplate tank, and a hot air hole is provided on the inner wall of the tinplate. The hot air hole is used to blow air toward the top surface of the tinplate column. The top surface of the tinplate is connected to a hot air duct, one end of the hot air duct is connected to the annular heating cavity, and the other end is connected to a high-temperature hot air blower.

[0013] Furthermore, it also includes a gantry conveying mechanism, which includes a conveying beam and two parallel overhead rails, the two ends of the conveying beam are respectively slidably set on the two overhead rails, and a lifting and loading rod is vertically arranged on the conveying beam. The bottom of the lifting and loading rod slides through the conveying beam and is connected to a negative pressure suction cup. A rack is fixed to the side wall of the lifting and loading rod, and a loading and unloading motor is installed on the conveying beam. The output shaft of the loading and unloading motor is connected to a gear, and the gear engages with the rack.

[0014] The beneficial effects of the present invention are: Place the chip soldering position of the circuit board with the chip facing downward into the tin plating tank of the tin plating plate. During this process, the tin plating plate moves downward so that the height of the tin plating plate entering the tin liquid is higher than the height of the tin plating column, so that the tin liquid overflows from the top of the tin plating column through the tin hole, and the excess tin liquid falls into the tin plating tank, leaving a layer of tin liquid on the top surface of the tin plating column. Then, the tin plating plate moves upward so that the tin plating column contacts the chip soldering position of the circuit board, thereby coating a tin layer on multiple chip soldering positions of the circuit board at one time, realizing automatic tin plating operation of the circuit board, improving production efficiency and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of a circuit board tinning system for circuit board chip welding of the present invention. Figure 1 ; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the structure of a circuit board tinning system for circuit board chip welding of the present invention. Figure 2 ; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram of the structure of a circuit board tinning system for circuit board chip welding of the present invention. Figure 3 ; Figure 6 A schematic diagram of the internal structure of a tin-plated plate in a circuit board tin-plating system for circuit board chip welding according to the present invention; Figure 7 A schematic diagram of the internal structure of a driving rod in a circuit board tinning system for circuit board chip welding according to the present invention; Figure 8 This is a schematic diagram of the structure of a circuit board tinning system for circuit board chip welding of the present invention. Figure 4 ; Figure 9 for Figure 8 Enlarged view of point C in the middle; In the figure, 1-tin liquid tank, 2-tin plate, 3-tinning tank, 4-tinning column, 5-tin hole, 6-tin chamber, 7-tin discharge hole, 8-tin discharge path hole, 9-tinning bar, 10-tin discharge slope, 11-round hole, 12-tin discharge piston, 13-wire hole, 14-driving block, 15-wire rope, 16-tinning frame, 17-driving horizontal plate, 18-lifting cylinder, 19-horizontal beam, 20-driving vertical rod, 21-screw groove, 22-screw, 23-screw slider, 24-driving rod, 25-small diameter hole, 26-large diameter hole, 27-disc, 28-sliding rod, 29-mounting disc, 30-motor, 31-U-shaped frame, 32-first guide wheel, 33-second guide wheel, 34-annular heating chamber, 35-hot air hole, 36-hot air duct, 37-long screw rod, 38-guide rod, 39-tin scraping slide, 40-L-shaped scraper, 41-metal scraper, 42-driving motor, 43-driving sprocket, 44-driven sprocket, 45-chain, 46-conveying beam, 47-ceiling rail, 48-lifting loading rod, 49-negative pressure suction cup, 50-rack, 51-loading and unloading motor, 52-gear. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0017] Example 1: like Figures 1 to 9As shown, a circuit board tinning system for circuit board chip welding comprises a tin liquid tank 1, a local tinning mechanism is arranged above the tin liquid tank 1, the local tinning mechanism comprises a tinning plate 2, a tinning tank 3 is provided on the top surface of the tinning plate 2, a plurality of tinning columns 4 are fixed in the tinning tank 3, and the plurality of tinning columns 4 correspond to the chip welding positions of the circuit board one by one, a tin hole 5 is provided through the top surface of the tinning column 4, and the tin hole 5 passes through the bottom of the tinning plate 2, and the top surface height of the tinning column 4 is lower than the top surface height of the tinning plate 2, a tin containing cavity 6 is provided on the tinning plate 2 below the tinning tank 3, a plurality of circular holes 11 are provided on the inner bottom wall of the tinning tank 3, and the circular holes 11 are connected to the tin containing cavity 6, a tin discharge hole 7 is provided on the side wall of the tinning plate 2, and the height of the tin discharge hole 7 is higher than the top surface height of the tinning column 4, and the tinning plate 2 is provided with a tin containing cavity 6 below the tinning tank 3. A tin discharge path hole 8 is provided in the tin plate 2, and the two ends of the tin discharge path hole 8 are respectively connected to the tin discharge hole 7 and one end of the tin containing cavity 6. It also includes a gantry conveying mechanism, which includes a conveying beam 46 and two parallel overhead rails 47. The two ends of the conveying beam 46 are respectively slidably arranged on the two overhead rails 47. A lifting and loading rod 48 is vertically provided on the conveying beam 46. The bottom of the lifting and loading rod 48 slides through the conveying beam 46 and is connected to a negative pressure suction cup 49. A rack 50 is fixed to the side wall of the lifting and loading rod 48. A loading and unloading motor 51 is installed on the conveying beam 46. The output shaft of the loading and unloading motor 51 is connected to a gear 52. The gear 52 engages the rack 50. Tin liquid is melted in the tin liquid tank 1. Tin bars are added to the tin liquid tank 1 at regular intervals to make the tin liquid tank 1 The liquid level inside is maintained within a certain range. A circuit board storage box is provided at one end of the tin liquid tank 1. The tin liquid tank 1 and the circuit board storage box are spaced apart along the moving direction of the conveying beam 46. A storage slot is provided on the top surface of the circuit board storage box. The shape of the storage slot matches the shape of the circuit board. The circuit boards are stacked along the height direction of the circuit board storage box, and the end surface of the circuit board with the chip welding position is set downward, thereby completing the positioning of the circuit board. The conveying beam 46 first drives the negative pressure suction cup 49 to move to the top of the circuit board storage box. The negative pressure suction cup 49 is connected to the negative pressure pump through a negative pressure pipe, and the circuit board is adsorbed by negative pressure for tinning. Negative pressure conveying belongs to the existing technology and will not be repeated here. The loading and unloading motor 51 drives the gear 52 to rotate, and the gear 52 is connected to the negative pressure pump through a negative pressure pipe. The engagement of the rack 50 drives the lifting loading rod 48 to move downward, so that the negative pressure suction cup 49 absorbs the circuit board, and then the loading and unloading motor 51 reverses to move the circuit board out of the circuit board storage box, and then the conveying beam 46 drives the circuit board to move to the top of the tin-plated plate 2, so that the chip welding position of the circuit board corresponds to the tin-plated column 4, and then the circuit board is placed in the tin-plating tank 3 of the tin-plated plate 2. During this process, the tin-plated plate 2 moves downward, so that the height of the tin-plated plate 2 entering the tin liquid is higher than the height of the tin-plated column 4, so that the tin liquid overflows from the top of the tin-plated column 4 through the tin hole 5, and the excess tin liquid falls into the tin-plating tank 3, leaving a layer of tin liquid on the top surface of the tin-plated column 4, and the tin liquid overflowing from the top of the tin-plated column 4 flows into the tin-plating tank 3. In order to prevent the tin liquid level in the tin-plating tank 3 from getting higher and higher,The tin liquid level in the tin plating tank 3 exceeds the height of the tin plating column 4, and the tin plating operation of the circuit board cannot be continued. A circular hole 11 is opened on the inner bottom wall of the tin plating tank 3, and the tin liquid in the tin plating tank 3 flows into the tin holding cavity 6 through the circular hole 11. The tin liquid in the tin holding cavity 6 flows back to the tin liquid tank 1 from the tin discharge hole 7 through the tin discharge path hole 8. The tin discharge hole 7 is arranged above the tin plating column 4, so that the tin liquid in the tin liquid tank 1 will not flow back into the tin plating tank 3 through the tin discharge hole 7. After tin liquid remains on the top surface of the tin plating column 4, the tin plating plate 2 moves upward to make the tin plating column 4 contact the chip welding position of the circuit board, thereby coating a tin layer on multiple chip welding positions of the circuit board at one time, realizing the automatic tin plating operation of the circuit board, improving production efficiency and reducing production costs. During specific implementation, the overhead rail 47 is fixedly installed, and the conveying beam 46 is installed on the overhead rail 47 by means of a screw rod. The conveying beam 46 is moved along the length direction of the overhead rail 47 by means of the screw rod. In order to reduce the layout length of the lifting and loading rod 48, a lifting plate is provided in the storage slot of the circuit board storage box, and a linear drive module is vertically provided on the outside of the circuit board storage box. A vertical slide groove is provided on the side wall of the circuit board storage box. The slide seat of the linear drive module is connected to the horizontal drive rod. The horizontal drive rod passes through the vertical slide groove into the storage slot and is connected to the lifting plate. The circuit board is lifted by the lifting plate, ensuring that the loading height of the circuit board remains unchanged, which can reduce the layout length of the lifting and loading rod 48.

[0018] Example 2: The main purpose of tinning on the circuit board is to plate a tin layer on the soldering holes of the chip pins so that the pin soldering holes will not be connected together due to the tin layer, ensuring that there will be no short circuit problem after the chip is soldered. Therefore, a continuous tin layer cannot be plated directly on the chip soldering position. It is necessary to plate the tin liquid on the pin soldering holes of the chip soldering position. For this purpose, based on the first embodiment, as shown in FIG. Figure 1 and Figure 2 As shown, a plurality of tin-plating strips 9 are fixed on the top of the tin-plating column 4, and the plurality of tin-plating strips 9 correspond one to one with the plurality of chip pin soldering positions in the chip soldering position. The top surface of the tin-plating column 4 forms a tin-discharging slope 10 between two adjacent tin-plating strips 9. The slope height of the tin-discharging slope 10 gradually decreases in the direction away from the tin hole 5. A tin layer is plated on the pin soldering hole by the tin-plating strips 9, and the tin-plating plate 2 moves downward to make the tin liquid in the tin liquid tank 1 overflow the tin-plating strips 9, so that tin liquid remains on the tin-plating strips 9. Under the action of the tin-discharging slope 10, the tin liquid between the two adjacent tin-plating strips 9 can flow into the tin-plating tank 3 in time, thereby ensuring that no tin liquid will remain between the tin-plating strips 9, and then each tin-plating strip 9 can contact the corresponding pin soldering hole individually, realizing automatic tinning of the pin soldering hole, ensuring that the pin soldering holes will not be connected in series, and that there will be no short circuit problem after the chip is soldered.

[0019] Example 3: Since the tin discharge hole 7 is opened above the tin plating column 4, the tin liquid in the tin chamber 6 also needs to be discharged in time, otherwise the tin liquid level in the tin plating tank 3 will gradually increase, affecting the tin plating operation, and the tin liquid needs to be discharged from the tin chamber 6 through the tin discharge hole 7, that is, the tin liquid needs to be discharged from a low place to a high place. For this reason, based on the second embodiment, as shown in FIG. Figures 1 to 6 As shown, a tin-discharging piston 12 is slidably provided in the tin-containing cavity 6, and two wire holes 13 are opened on the top surface of the tin-plating plate 2 on one side of the tin-plating tank 3, one of which is connected to the tin-discharging path hole 8, and the other wire hole 13 is connected to the other end of the tin-containing cavity 6. A driving block 14 is slidably provided on the top surface of the tin-plating plate 2 on the other side of the tin-plating tank 3. The driving block 14 moves along the length direction of the tin-containing cavity 6. Both ends of the driving block 14 are connected to steel wire ropes 15, one of which is inserted from one wire hole 13 into one end of the tin-discharging piston 12, and the other wire rope 15 is inserted from the other wire hole 13 into the other end of the tin-discharging piston 12. The driving block 14 and the tin-discharging piston 12 is connected to two steel wire ropes 15 to form a closed ring, and the driving block 14 moves along the length direction of the tin-containing cavity 6, that is, the driving block 14 moves close to the tin discharge hole 7, so that one steel wire rope 15 pulls the tin discharge piston 12 to move close to the tin discharge hole 7, and the other steel wire rope 15 follows the movement of the tin discharge piston 12, so that the tin discharge piston 12 can discharge the tin liquid in the tin-containing cavity 6 through the tin discharge path hole 8 and the tin discharge hole 7 into the tin liquid tank 1, then, the driving block 14 moves in the opposite direction, so that the tin discharge piston 12 moves away from the tin discharge hole 7, so that the other steel wire rope 15 pulls the tin discharge piston 12 to reset, and after each circuit board tin plating operation is completed, a tin discharge operation of the tin-containing cavity 6 is performed.

[0020] Example 4: Based on the third embodiment, Figures 1 to 7As shown, the local tinning mechanism also includes a tinning frame 16 and a lifting cylinder 18. The lifting cylinder 18 is vertically installed on the tinning frame 16. The telescopic shaft of the lifting cylinder 18 is connected to a driving vertical rod 20. The side wall of the tin plate 2 close to the driving block 14 is fixed with a horizontal beam 19. The bottom end of the driving vertical rod 20 is connected to the horizontal beam 19 through a flange. The telescopic movement of the lifting cylinder 18 drives the driving vertical rod 20 to move up and down. The driving vertical rod 20 drives the tin plate 2 to move up and down through the horizontal beam 19, so that the top surface of the tinned column 4 can move smoothly. The tin liquid is retained to complete the tinning operation of the circuit board chip welding position. A driving cross plate 17 is fixed on the tinning frame 16. A screw groove 21 is opened on the driving cross plate 17 along the moving direction of the driving block 14. The screw groove 21 runs through the height direction of the driving cross plate 17. A screw 22 is rotated in the screw groove 21. A screw slider 23 is threaded on the screw 22. The screw slider 23 slides and fits into the screw groove 21. A driving rod 24 is fixed to the bottom of the screw slider 23. The bottom of the driving rod 24 is rotated from bottom to top according to the screw groove 21. A small diameter hole 25 and a large diameter hole 26 are opened, and a disc 27 is slidably fitted in the large diameter hole 26. The diameter of the disc 27 is larger than the diameter of the small diameter hole 25. A sliding rod 28 is slidably fitted in the small diameter hole 25. One end of the sliding rod 28 is fixedly connected to the disc 27, and the other end is fixed with a mounting disc 29. The mounting disc 29 is connected to the drive block 14 through screws. A motor 30 is installed on the driving horizontal plate 17. The output shaft of the motor 30 is driven to connect the screw rod 22, and the motor 30 drives the screw rod 22 to rotate. The screw slider 23 is made to move linearly along the axial direction of the screw rod 22. The screw slider 23 drives the driving block 14 to move along the length direction of the tin chamber 6 through the driving rod 24 and the sliding rod 28. The sliding rod 28 and the driving rod 24 are installed in a set manner, so that when the tinplate 2 moves up and down, the sliding rod 28 can slide on the driving rod 24, so that the tinplate 2 will not interfere with the sliding rod 28. While the driving block 14 moves, the tinplate 2 can move up and down smoothly to complete the tinning and tin discharging operations. During specific implementation, different circuit boards are correspondingly configured with tin-plated plates 2, the sliding rod 28 is installed with a disc 29 that is detachably connected to the drive block 14, and the driving vertical rod 20 is connected to the horizontal beam 19 through a flange, thereby removing the tin-plated plate 2, making it convenient to install the corresponding tin-plated plate 2 according to the model of the circuit board for tinning the circuit board; it should be noted that through the setting of the driving vertical rod 20, and the set setting of the driving rod 24 and the sliding rod 28, the tin-plated plate 2 and the driving block 14 can be driven to move over a long distance, thereby avoiding the high temperature in the tin liquid tank 1 affecting the operation of the lifting cylinder 18 and the motor 30.

[0021] Embodiment 5: Based on the fourth embodiment, Figures 1 to 4As shown, a U-shaped frame 31 is provided just above the wire hole 13, and the closed end of the U-shaped frame 31 is fixedly connected to the tin plate 2 through a plate. A first guide wheel 32 is rotatably provided in the U-shaped opening of the U-shaped frame 31, and the axis of the first guide wheel 32 is arranged horizontally. Two second guide wheels 33 are arranged on the tin plate 2 along the moving direction of the driving block 14. The driving block 14 is located between the two second guide wheels 33, and the axis of the second guide wheel 33 is arranged vertically. One of the steel wire ropes 15 passes around one of the first guide wheels 32 and one of the second guide wheels 33 to connect one end of the driving block 14. , another steel wire rope 15 passes around another first guide wheel 32 and another second guide wheel 33 to connect to the other end of the driving block 14, and is used to arrange the steel wire rope 15 around the tin plating tank 3. The arrangement direction of the steel wire rope 15 is adjusted by the first guide wheel 32 and the second guide wheel 33, so that the steel wire rope 15 is connected to the driving block 14 around the tin plating tank 3. At the same time, under the action of the first guide wheel 32 and the second guide wheel 33, the movement of the steel wire rope 15 is smoother, so that the driving block 14 can smoothly drive the tin discharge piston 12 to move through the steel wire rope 15, thereby realizing the discharge of tin liquid in the tin holding cavity 6.

[0022] Example 6: Since an oxide layer will form on the surface of the tin liquid, in order to prevent the oxide layer from flowing along the tin liquid and falling on the surface of the tin-plated pillar 4, causing the oxide layer to be plated on the chip soldering position, affecting the tin plating effect, for this reason, based on the embodiment 5, as shown in FIG. Figures 1 to 9 As shown, a long screw rod 37 and a guide rod 38 are arranged in parallel in the tin liquid tank 1. The long screw rod 37 and the guide rod 38 are both located on one side of the tin-plated plate 2. A tin scraping slide 39 is threadedly sleeved on the long screw rod 37. The tin scraping slide 39 is slidably sleeved on the guide rod 38. An L-shaped scraper 40 is fixed on the side of the tin scraping slide 39 close to the tin-plated plate 2. Metal scrapers 41 are fixed to the top and bottom surfaces of the horizontal section of the L-shaped scraper 40. The two metal scrapers 41 respectively scrape off the tin layer on the tin liquid surface and the tin layer on the bottom of the tin-plated plate 2. A driving motor 42 is arranged away from the tin liquid tank 1. The output shaft of the driving motor 42 is connected to a driving sprocket 43. One end of the long screw rod 37 is connected to a driven sprocket 44. The driven sprocket 4 The driving sprocket 43 is connected to the tin plate 2 through the chain 45. Before the tin plate 2 goes down into the tin liquid, the driving motor 42 is started, so that the driving sprocket 43 drives the driven sprocket 44 to rotate through the chain 45. The driven sprocket 44 drives the long screw rod 37 to rotate. The rotational freedom of the tin scraping slide 39 is limited by the guide rod 38, so that the tin scraping slide 39 moves linearly along the axial direction of the long screw rod 37. The tin scraping slide 39 drives the metal scraper 41 to move. The bottom surface of the lower metal scraper 41 contacts the surface of the tin liquid, and the top surface of the upper metal scraper 41 contacts the bottom surface of the tin plate 2. Thus, the oxide layer is scraped off by the metal scraper 41, preventing the oxide layer from being plated on the circuit board, thereby improving the tin plating effect of the circuit board.

[0023] Embodiment seven: Based on Example 6, Figures 1 to 9 As shown, an annular heating chamber 34 is provided around the tin plating tank 3 in the tin-plated plate 2, and a hot air hole 35 is provided on the inner wall of the tin-plated plate 2. The hot air hole 35 is used to blow air to the top surface of the tin-plated column 4. The top surface of the tin-plated plate 2 is connected to a hot air duct 36. One end of the hot air duct 36 is connected to the annular heating chamber 34, and the other end is connected to a high-temperature hot air blower. The oxide layer in the tin hole 5 will also flow with the tin liquid. There is still a risk of an oxide layer adhering to the top surface of the tin-plated strip 9. For this reason, hot air is generated by the high-temperature hot air blower, and the hot air enters the annular heating chamber 34 through the hot air duct 36. Finally, hot air is blown to the tin-plated strip 9 through the hot air hole 35 to blow off the oxide layer on the surface of the tin-plated strip 9, so that the subsequent tin liquid remains on the tin-plated strip 9, and the hot air can ensure that the tin liquid on the tin-plated strip 9 will not solidify, so that it can be smoothly plated on the circuit board.

Claims

1. A circuit board tinning system for circuit board chip welding, comprising a tin liquid tank (1), characterized in that: A local tinning mechanism is provided above the tin liquid tank (1), and the local tinning mechanism comprises a tin plate (2), a tin plate tank (3) is provided on the top surface of the tin plate (2), a plurality of tin plates (4) are fixed in the tin plate tank (3), the plurality of tin plates (4) correspond to the chip soldering positions of the circuit board one by one, a tin hole (5) is provided through the top surface of the tin plates (4), the tin hole (5) passes through the bottom of the tin plate (2), and the top surface height of the tin plates (4) is lower than the top surface height of the tin plate (2). The tin-plated plate (2) is provided with a tin-containing cavity (6) below the tin-plating tank (3), and a plurality of circular holes (11) are provided on the inner bottom wall of the tin-plating tank (3), wherein the circular holes (11) are connected to the tin-containing cavity (6). A tin-discharging hole (7) is provided on the side wall of the tin-plated plate (2), wherein the height of the tin-discharging hole (7) is higher than the height of the top surface of the tin-plating column (4), and a tin-discharging path hole (8) is provided in the tin-plated plate (2), wherein two ends of the tin-discharging path hole (8) are respectively connected to the tin-discharging hole (7) and one end of the tin-containing cavity (6).

2. A circuit board tinning system for circuit board chip welding according to claim 1, characterized in that: A plurality of tinned bars (9) are fixed on the top of the tinned column (4), and the plurality of tinned bars (9) correspond one-to-one to a plurality of chip pin welding positions in the chip welding position.

3. A circuit board tinning system for circuit board chip welding according to claim 2, characterized in that: The top surface of the tin-plated column (4) forms a tin-discharging slope (10) between two adjacent tin-plated strips (9), and the slope height of the tin-discharging slope (10) gradually decreases in a direction away from the tin-passing hole (5).

4. A circuit board tinning system for circuit board chip welding according to claim 1, characterized in that: A tin-discharging piston (12) is slidably provided in the tin-containing cavity (6), and two wire holes (13) are provided on the top surface of the tin-plated plate (2) on one side of the tin-plating tank (3), one of the wire holes (13) is connected to the tin-discharging path hole (8), and the other wire hole (13) is connected to the other end of the tin-containing cavity (6). A driving block (14) is slidably provided on the top surface of the tin-plated plate (2) on the other side of the tin-plating tank (3), and the driving block (14) moves along the length direction of the tin-containing cavity (6). Both ends of the driving block (14) are connected to steel wire ropes (15), one of the steel wire ropes (15) is passed through one of the wire holes (13) to connect to one end of the tin-discharging piston (12), and the other steel wire rope (15) is passed through the other wire hole (13) to connect to the other end of the tin-discharging piston (12).

5. A circuit board tinning system for circuit board chip welding according to claim 4, characterized in that: The local tinning mechanism further comprises a tinning frame (16) and a lifting cylinder (18), wherein the lifting cylinder (18) is vertically mounted on the tinning frame (16), the telescopic shaft of the lifting cylinder (18) is connected to a driving vertical rod (20), a horizontal beam (19) is fixed to the side wall of the tinning plate (2) close to the driving block (14), and the bottom end of the driving vertical rod (20) is connected to the horizontal beam (19) via a flange.

6. A circuit board tinning system for circuit board chip soldering according to claim 5, characterized in that: A driving transverse plate (17) is fixed on the tinning frame (16), and a screw groove (21) is provided on the driving transverse plate (17) along the moving direction of the driving block (14), and the screw groove (21) runs through the height direction of the driving transverse plate (17). A screw (22) is rotatably provided in the screw groove (21), and a screw slider (23) is threadedly sleeved on the screw (22), and the screw slider (23) is slidably adapted to the screw groove (21). A driving rod (24) is fixed to the bottom of the screw slider (23), and the bottom of the driving rod (24) is provided with small screws from bottom to top. The large diameter hole (25) and the large diameter hole (26) are provided with a disc (27) for sliding adaptation in the large diameter hole (26), the diameter of the disc (27) is larger than the diameter of the small diameter hole (25), and the small diameter hole (25) is provided with a sliding rod (28) for sliding adaptation in the small diameter hole (25), one end of the sliding rod (28) is fixedly connected to the disc (27), and the other end is fixed with a mounting disc (29), the mounting disc (29) is connected to the driving block (14) by screws, a motor (30) is installed on the driving cross plate (17), and the output shaft of the motor (30) is transmission-connected to the screw rod (22).

7. A circuit board tinning system for circuit board chip soldering according to claim 6, characterized in that: A U-shaped frame (31) is provided just above the wire hole (13), the closed end of the U-shaped frame (31) is fixedly connected to the tin-plated plate (2) through a plate, a first guide wheel (32) is rotatably provided in the U-shaped opening of the U-shaped frame (31), the axis of the first guide wheel (32) is arranged horizontally, two second guide wheels (33) are arranged on the tin-plated plate (2) along the moving direction of the driving block (14), the driving block (14) is located between the two second guide wheels (33), the axis of the second guide wheel (33) is arranged vertically, one of the steel wire ropes (15) passes around one of the first guide wheels (32), one of the second guide wheels (33) is connected to one end of the driving block (14), and the other steel wire rope (15) passes around the other first guide wheel (32), the other second guide wheel (33) is connected to the other end of the driving block (14), so as to arrange the steel wire rope (15) around the tin-plated tank (3).

8. The circuit board tinning system for circuit board chip welding according to claim 1, characterized in that: A long screw rod (37) and a guide rod (38) are arranged in parallel in the tin liquid tank (1). The long screw rod (37) and the guide rod (38) are both located on one side of the tin plate (2). A tin scraping slide (39) is threadedly sleeved on the long screw rod (37). The tin scraping slide (39) is slidably sleeved on the guide rod (38). An L-shaped scraper (40) is fixed on the side of the tin scraping slide (39) close to the tin plate (2). The L-shaped scraper (40) is horizontally Metal scrapers (41) are fixed to the top and bottom surfaces of the segment, and the two metal scrapers (41) scrape off the tin layer on the tin liquid surface and the tin layer on the bottom of the tin-plated plate (2) respectively. A driving motor (42) is arranged away from the tin liquid tank (1), and the output shaft of the driving motor (42) is connected to a driving sprocket (43). One end of the filament rod (37) is connected to a driven sprocket (44), and the driven sprocket (44) is connected to the driving sprocket (43) through a chain (45).

9. A circuit board tinning system for circuit board chip soldering according to claim 8, characterized in that: An annular heating chamber (34) is provided in the tinplate (2) around the tinplate tank (3), and a hot air hole (35) is provided on the inner wall of the tinplate (2). The hot air hole (35) is used to blow air toward the top surface of the tinplate column (4). The top surface of the tinplate (2) is connected to a hot air duct (36), one end of the hot air duct (36) is connected to the annular heating chamber (34), and the other end is connected to a high-temperature hot air blower.

10. The circuit board tinning system for circuit board chip welding according to claim 1, characterized in that: The invention also includes a gantry conveying mechanism, which includes a conveying beam (46) and two parallel overhead rails (47), the two ends of the conveying beam (46) are respectively slidably arranged on the two overhead rails (47), a lifting and loading rod (48) is vertically arranged on the conveying beam (46), the bottom of the lifting and loading rod (48) slides through the conveying beam (46) and is connected to a negative pressure suction cup (49), a rack (50) is fixed to the side wall of the lifting and loading rod (48), a loading and unloading motor (51) is installed on the conveying beam (46), the output shaft of the loading and unloading motor (51) is connected to a gear (52), and the gear (52) engages with the rack (50).

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